JP7634503B2 - Motor-operated valve and refrigeration cycle system using the same - Google Patents

Description

The present invention relates to an electrically operated valve equipped with a means for suppressing radial movement of a drive shaft and a refrigeration cycle system using the same.

As shown in FIG. 15(a), the conventional motor-operated valve 1500 has a first joint pipe 1501 connected to a valve chamber 1512 attached to the side of a valve body 1510, a second joint pipe 1502 and a valve seat member 1511 attached to the lower end of the valve body 1510, and a valve port 1511a centered on the axis L is formed in the valve seat member 1511. A support member 1520 is attached to the upper part of the valve body 1510, and a female thread portion 1523a is formed in the support member 1520. A drive shaft 1530 connected to a magnet rotor 1562 of a stepping motor 1560 is disposed in the female thread portion 1523a by screwing the male thread portion 1531a. Furthermore, a valve body portion 1540 is attached to the lower part of the drive shaft 1530. The valve body 1540 moves in the direction of axis L together with the drive shaft 1530 due to the screw feed mechanism between the male threaded portion 1531a and the female threaded portion 1523a as the drive shaft 1530 rotates, opening and closing the valve port 1511a.

Due to its structure, this screw feed mechanism has a slight clearance (hereinafter referred to as "screw backlash") between the female threaded portion 1523a and the male threaded portion 1531a in the axial L direction and radial direction (see FIG. 15(b)). Therefore, when adjusting the opening of the valve port 1511a, the male threaded portion 1531a of the drive shaft 1530 fixed to the magnet rotor 1562 performs a complex spiral motion in which the axis is shifted relative to the female threaded portion 1523a and moves in the axial L direction while rotating and oscillating due to the characteristics of the stepping motor 1560. During this spiral motion, centrifugal force, which is a radial component force, is always acting on the male threaded portion 1531a, so the flanks of the male threaded portion 1531a and the female threaded portion 1523a are urged radially with a relatively strong force. However, because this centrifugal force is unsteady, the male thread 1531a frequently repeats radial movement relative to the female thread 1523a. At this time, the contact area of the flanks (the inclined surfaces of the male thread and female thread) of the screw feed mechanism is constantly changing, so that an unsteady radial component force as well as an unsteady axial component force act simultaneously on the male thread 1531a via the flanks. As a result, the flanks of the screw feed mechanism momentarily come into contact with and separate from each other in the radial and axial directions, i.e., collide with each other (hereinafter referred to as "conventional problem (collision in the screw feed mechanism)"), and the resulting vibrations and collisions are propagated to the outside as operating noise.

In addition, because this motor valve is placed inside the indoor unit of an air conditioner, low operating noise is required. In addition, in recent air conditioners, due to changes in refrigerants and improvements in the performance of oil separators, there are cases where the amount of lubricant, such as refrigeration oil, that returns to the motor valve is reduced. For this reason, motor valves are required to operate quietly, even in a dry (out of oil) state.

In response to this, Patent Document 1 describes an electrically operated valve in which a coil spring constantly presses the drive shaft in the axial direction to compensate for the slight axial clearance between the female and male threads, thereby constantly bringing the female and male threads into contact in the axial direction.

However, in Patent Document 1, the drive shaft is pressed in the axial direction by a coil spring, which requires space in the axial direction, resulting in an increase in size in the axial direction. In addition, the male thread still performs a complex spiral motion relative to the female thread, making it impossible to resolve the conventional problem (collision in the screw feed mechanism).

Patent Document 2 also describes a control valve in which a mechanism for preventing lateral movement of a valve body connected to the lower end of a drive shaft is described, in which a steel ball is movably inserted into a through hole formed in a support member, and a biasing member is engaged and attached to a circumferential groove formed in the support member, so that the biasing member biases the steel ball in a direction perpendicular to the axis.

However, as for the detailed connection structure between the drive shaft and the valve body in Patent Document 2, as can be seen from Patent Document 3, the valve body is connected to the drive shaft in a movable state with radial play. Therefore, even in Patent Document 2, the biasing force on the valve body does not act on the drive shaft, so the male threaded portion still makes a complex spiral motion relative to the female threaded portion, and the conventional problem (collision in the screw feed mechanism) could not be resolved.

JP 2017-145923 A JP 2000-120883 A Japanese Patent Application Publication No. 10-2450

The object of the present invention is to provide an electrically operated valve equipped with a means for suppressing radial movement of a drive shaft, which can achieve low operating noise, and a refrigeration cycle system using the same.

To solve the above problem, the motor-operated valve is provided with a support member having a drive shaft that moves in the axial direction by a screw feed mechanism that converts rotational motion into linear motion through a male threaded portion and a female threaded portion that are screwed together, a bearing portion that engages with a guide portion of the drive shaft and guides the drive shaft in the axial direction, a valve body that is connected to the guide portion of the drive shaft and adjusts the opening degree with respect to the valve seat of the valve port, and radial movement suppression means that biases one of the male threaded portion and the female threaded portion in a direction perpendicular to the axis and suppresses relative radial movement of the male threaded portion and the female threaded portion.

In the motor-operated valve, the radial movement suppression means may be provided between the bearing portion and the guide portion.

In the motor-operated valve, the radial movement suppression means may have an abutment member that contacts the drive shaft, and bias one of the male threaded portion and the female threaded portion in a direction perpendicular to the axis via the abutment member.

In the motor-operated valve, the contact state between the drive shaft of the radial movement suppression means and the abutment member may be at least one line contact extending in the axial direction of the drive shaft.

In addition, in the above-mentioned motor-operated valve, the contact state between the drive shaft of the radial movement suppression means and the abutment member may be at least one point contact.

In the above-mentioned motor-operated valve, the abutment member may be disposed opposite the outer peripheral surface of the drive shaft, and the radial movement suppression means may further include a biasing member that applies a biasing force to the abutment member.

In the above motor-operated valve, the abutment member may be substantially L-shaped and have an abutment portion that abuts against the drive shaft, and a biasing portion that extends along the outer circumferential surface of the support member and is spaced apart from the axis of the abutment portion and abuts against the biasing member.

In the above motor-operated valve, the biasing portion may extend along the axial direction of the outer peripheral surface of the support member.

In the above motor-operated valve, the biasing member may be C-shaped with a notch, and a pair of ends of the biasing member may be provided with anti-rotation engagement portions that are directly or indirectly held by the support member.

In addition, in the above-mentioned motor-operated valve, a rotation stopper may be provided on the radially outer side of the contact member, and the rotation stopper engagement portion of the biasing member may be engaged with the rotation stopper, thereby holding the biasing member to the support member via the contact member.

In the above motor-operated valve, a circumferential mounting groove may be formed on the outer peripheral surface of the support member, a rotation stopper may be provided on the support member so that the circumferential mounting groove is discontinuous in the circumferential direction, and the rotation stopper engagement portion of the biasing member may be engaged with the rotation stopper, so that the biasing member is held by the support member.

In the above motor-operated valve, a continuous circumferential mounting groove may be formed on the outer circumferential surface of the support member, a rotation stopper portion may be provided that is continuously connected to the circumferential mounting groove inward in the radial direction or in the axial direction, and the rotation stopper engagement portion of the biasing member may be engaged with the rotation stopper portion, so that the biasing member is held by the support member.

In the motor-operated valve, the radial movement suppression means may further include a retaining member that holds the biasing member between the contact member and the retaining member.

In the motor-operated valve, the abutment member may be made of a ring-shaped elastic member, and may further include a holding member that holds the abutment member between the drive shaft and the drive shaft when the abutment member is deformed in a direction perpendicular to the axis.

In the motor-operated valve, the abutment member may be made of a ring-shaped elastic member and may be disposed in a circumferential groove of the drive shaft in a state where the abutment member is deformed in a direction perpendicular to the axis.

In the above-mentioned motor-operated valve, the valve body may be connected to the drive shaft so as to be displaceable relative to the drive shaft in the radial direction, and the radial movement suppression means may bias the drive shaft.

The refrigeration cycle system may also include a compressor, a condenser, an expansion valve, and an evaporator, and the motor-operated valve may be used as the expansion valve.

The present invention provides an electrically operated valve equipped with a means for suppressing radial movement of a drive shaft, which can achieve low operating noise, and a refrigeration cycle system using the same.

1A and 1B are cross-sectional views showing an electric valve according to a first embodiment of the present invention, in which (a) is a longitudinal cross-sectional view of the electric valve, (b) is an enlarged view of the Ib-Ib cross section of (a), (c) is an enlarged view of the cross section in (b) with the biasing member removed, and (d) is an explanatory diagram of the rotational axis motion using the enlarged Id-Id cross section of (a). 1A and 1B are enlarged cross-sectional views showing a radial movement suppression means (a form in which the rotation of the biasing member is stopped by the abutment member) according to variant example 1-1 of the first embodiment of the present invention, in which (a) shows variant example 1-1(1) (a form using a protrusion portion of the abutment member), (b) shows variant example 1-1(2) (a form using a recess portion of the abutment member), and (c) shows variant example 1-1(3) (a form using a straight portion of the abutment member). FIG. 11 is an enlarged view showing a radial movement suppression means (a form in which a holder stops rotation of a biasing member) according to variant example 1-2 of the first embodiment of the present invention, where (a), (c), (e), and (g) are enlarged cross-sectional views, and (b), (d), (f), and (h) are enlarged side views, with (a)-(b) representing variant example 1-2(1) (a form using a convex portion of the holder), (c)-(d) representing variant example 1-2(2) (a form using a stopper pin engaged with the holder), (e)-(f) representing variant example 1-2(3) (a form using a radial groove of the holder), and (g)-(h) representing variant example 1-2(4) (a form using an axial groove of the holder). FIG. 2 is an enlarged view showing a radial movement suppression means (a form in which stable support is provided by the contact portion of the abutment member) relating to variant 2-1 of the first embodiment of the present invention, in which (a) and (c) show the contact state of the abutment member and the guide portion, (b) and (d) show the contact area of the abutment member, and (a)-(b) show variant 2-1(1) (contact portion having an inverted arc shape), and (c)-(d) show variant 2-1(2) (contact portion having a tapered shape). 5A and 5B are schematic diagrams illustrating a contact state between the cylindrical guide portion and the tapered contact portion in FIG. 4C . 1A to 1D are enlarged views showing a radial movement suppression means (a form in which sliding resistance is reduced by the contact portion of the abutment member) according to variant 2-2 of the first embodiment of the present invention, in which (a) and (c) show the contact state of the abutment member and the guide portion, (b) and (d) show the contact area of the abutment member, and (a)-(b) show variant 2-2(1) (spherical contact portion), and (c)-(d) show variant 2-2(2) (contact portion consisting of multiple spherical shapes). FIG. 3 is an enlarged cross-sectional view showing a radial movement suppressing means (a form for suppressing circumferential rattling of the abutment portion) according to Modification 3-1 of the first embodiment of the present invention. 3A and 3B are cross-sectional views showing an electric valve equipped with a radial movement suppression means (a form for suppressing axial backlash of the abutment portion) according to variant 3-2 of the first embodiment of the present invention, in which (a) is a longitudinal cross-sectional view of the electric valve, (b) is an enlarged view of the dashed line area VIIIb in (a), and (c) is an enlarged view of the VIIIc-VIIIc cross section in (a). 9A and 9B are top perspective views showing the support member and abutment member of Figure 8, where (a) shows the support member as viewed from the rotation stop portion side of the urging member, (b) shows the support member as viewed from the abutment member side of the urging member, and (c) shows the abutment member as viewed from the abutment portion side. 5A and 5B are cross-sectional views showing a motor-operated valve according to a second embodiment, in which FIG. 5A is a longitudinal cross-sectional view of the motor-operated valve, and FIG. 5B is an enlarged cross-sectional view of the motor-operated valve shown in FIG. 11A and 11B are cross-sectional views showing a motor-operated valve according to a third embodiment, in which (a) is a longitudinal cross-sectional view of the motor-operated valve, and (b) is an enlarged cross-sectional view taken along line XIb-XIb of (a). 13A and 13B are cross-sectional views showing a motor-operated valve according to a fourth embodiment, in which FIG. 13A is a longitudinal cross-sectional view of the motor-operated valve, and FIG. 13B is an enlarged cross-sectional view of FIG. 13A taken along line XIIb-XIIb. 11A and 11B are cross-sectional views showing a motor-operated valve according to a fifth embodiment, in which (a) is a longitudinal cross-sectional view of the motor-operated valve, and (b) is an enlarged cross-sectional view taken along line XIIIb-XIIIb of (a). FIG. 1 is a diagram showing a refrigeration cycle system of the present invention. 1A and 1B are cross-sectional views showing a motor-operated valve according to a conventional technique, in which FIG. 1A is a longitudinal cross-sectional view of the motor-operated valve, and FIG. 1B is an explanatory diagram of spiral motion using an enlarged cross-sectional view of XVb-XVb in FIG.

The embodiment of the present invention will be described in detail with reference to Figs. 1 to 14. Note that although the following describes a motor-operated valve, the radial movement suppression means of the present invention is not limited to motor-operated valves and can also be applied to other devices and systems, such as linear actuators.

<Terminology>
In this specification and the claims, the terms "line contact" and "point contact" refer to the contact state when viewed macroscopically (treated geometrically), without taking into account surface irregularities and the like when viewed microscopically.

(First embodiment)
<Configuration of the motor-operated valve>
A motor-operated valve 100a according to a first embodiment of the present invention will be described with reference to FIG. 1. The motor-operated valve 100a is mainly composed of a valve body 10, a support member 20, a drive shaft 30, a valve body portion 40, a coil member 50, a stepping motor 60, and a radial movement suppression means 70a. Each component of the motor-operated valve 100a will be described in order below. Here, the motor-operated valve 100a of this embodiment employs a radial movement suppression means 70a for the drive shaft 30, which will be described in detail later. The radial movement suppression means 70a biases the male thread portion 31a in a direction perpendicular to the axis L, thereby suppressing the radial movement of the male thread portion (screw feed mechanism portion) 31a relative to the female thread portion (screw feed mechanism portion) 23a, thereby eliminating the conventional problem (collision in the screw feed mechanism portion) and achieving low operating noise.

The valve body 10 is formed in a cylindrical shape using a metal such as stainless steel. The valve body 10 is provided with a valve seat member 11 formed separately from the valve body 10 so as to close the lower end. A valve port 11a opens in the center of the valve seat member 11. The valve body 10 forms a valve chamber 12 inside.

A first coupling tube 1, which serves as a flow path for a fluid such as a refrigerant, is connected to one side of the outer periphery of the valve body 10, and this first coupling tube 1 is connected to a valve chamber 12. A second coupling tube 2, which is in contact with a valve seat member 11, is connected to the bottom side of the valve body 10, and this second coupling tube 2 is connected to the valve chamber 12 via a valve port 11a. The first coupling tube 1 and the second coupling tube 2 are made of materials such as copper or stainless steel, and are fixed to the valve body 10 by brazing or the like.

The support member 20 comprises a substantially cylindrical holder portion 21 made of a resin material such as polyphenylene sulfide (PPS), and a stainless steel fixing portion 22 that is integrally formed by insert molding on the end of the holder portion 21 closer to the valve body 10. The support member 20 is fixed to the valve body 10 by welding using the fixing portion 22.

The holder part 21 is arranged so that its axis overlaps with the axis L passing through the axis of the valve port 11a. A screw hole 23, a bearing hole (bearing part) 24, and a slide hole 25 are formed concentrically in the center of the holder part 21, aligned in the direction of the axis L so as to penetrate the holder part 21. A female thread part 23a is formed on the inner peripheral surface of the screw hole 23, and a male thread part 31a of the drive shaft 30 described later is screwed into it. A guide part 32 of the drive shaft 30 described later is slidably engaged with the inner peripheral surface of the bearing hole 24. The slide hole 25 is arranged closer to the valve port 11a and is formed with a larger diameter than the bearing hole 24. A valve body part 40 described later is slidably engaged with the slide hole 25.

A guide rail 26 consisting of a helical ridge is integrally formed on the outer circumferential surface of the holder portion 21. Adjacent winding portions of the guide rail 26 are arranged with a gap between them. The guide rail 26 is arranged so that its axis overlaps with the axis L, and guides each winding portion of the coil portion 51 from one or both sides so that the coil portion 51 of the coil member 50 described below is screwed into the guide rail 26 and the coil member 50 can rotate in the circumferential direction.

The drive shaft 30 is formed in a cylindrical rod shape using a metal such as stainless steel. The drive shaft 30 is formed with a threaded portion 31, a guide portion 32, and a flange portion 33 arranged at the end of the guide portion 32 near the valve port 11a, which are aligned in the axial direction L. The threaded portion 31 is formed with a male threaded portion 31a, which is screwed into the female threaded portion 23a of the holder portion 21 to convert the rotational motion of the drive shaft 30 into linear motion. The guide portion 32 is slidably engaged with the inner circumferential surface of the bearing hole 24 to guide the movement of the drive shaft 30 in the axial direction L. The details will be described later, but the drive shaft 30 is positioned at an offset position O1 (see FIG. 1(d)) in the direction perpendicular to the axial line L by a radial movement suppression means 70a provided in the bearing hole 24, and is moved in the axial direction L by the screw feed action due to rotation. The flange portion 33 rotatably engages the valve body portion 40, which will be described later. In this embodiment, the female thread portion 23a and the male thread portion 31a are right-handed threads.

The valve body portion 40 includes a valve holder 41, a valve body 42, a washer 43, a spring retainer 44, and a compression coil spring 45.

The valve holder 41 is formed in a cylindrical shape with an outer diameter that is approximately the same as the inner diameter of the slide hole 25 of the holder part 21. The valve holder 41 is engaged so as to be slidable in the direction of the axis L along the slide hole 25.

The valve body 42 is needle-shaped and is fixed to the lower end 41a of the valve holder 41 on the valve port 11a side so that the tip of the needle faces the valve port 11a. The valve body 42 adjusts the flow rate by adjusting the opening between the valve port 11a and the valve seat between the maximum valve opening and the minimum valve opening (or fully closed state).

The flange portion 33 of the drive shaft 30 is rotatably hooked to the upper end 41b of the valve holder 41 on the side opposite to the valve port 11a side. Specifically, the flange portion 33 of the drive shaft 30 sandwiches a washer 43 between the upper end 41b of the valve holder 41 and the flange portion 33, and the drive shaft 30 is rotatably hooked to the upper end 41b of the valve holder 41 by this flange portion 33. Due to this engagement, the valve holder 41 is supported by the drive shaft 30 so that it can move in the axial direction L and can rotate around the axial direction L. In addition, an opening larger than the radial movable range of the drive shaft 30 is formed at the upper end 41b of the valve holder 41. In addition, a spring bearing 44 is provided in the valve holder 41 so as to be movable in the axial direction L. A compression coil spring 45 is attached between the spring bearing 44 and the valve body 42 in a compressed state with a predetermined load applied. As a result, the spring bearing 44 is pressed against the drive shaft 30 and comes into contact with the flange portion 33 of the drive shaft 30.

In this embodiment, the valve body 40 is connected to the drive shaft 30 so that it can be displaced radially relative to the drive shaft 30. As described in detail below, when the radial movement suppression means 70a biases the male threaded portion 31a in a direction perpendicular to the axis L, the influence of this bias can be reliably reduced from being transmitted to the valve body 40.

The coil member 50 is integrally provided with a coil spring-shaped coil portion 51 and a claw portion 52 that protrudes radially outward from one end of the coil portion 51. The coil portion 51 is screwed to the guide rail 26 of the holder portion 21 so as to be rotatable in the circumferential direction. The claw portion 52 can abut against a protrusion 67 of the magnet rotor 62 described later, and the rotation of the magnet rotor 62 pushes the coil member 50 around in the circumferential direction via the claw portion 52. As a result, the coil member 50 hits an upper limit stopper (not shown) or a lower limit stopper (not shown), restricting the rotation of the coil member 50 and also restricting the rotation of the magnet rotor 62. Therefore, the valve body portion 40 is restricted from moving beyond the position where the valve body portion 40 is at the maximum opening degree or the position where the valve body portion 40 is at the minimum opening degree (or the valve is closed). The coil member 50 can be easily manufactured by forming a metal wire such as stainless steel.

The stepping motor 60 includes a case 61, a magnet rotor 62, and a stator coil (not shown).

The case 61 is made of a metal such as stainless steel and is formed in a generally cylindrical shape with the upper end closed. The lower open end of the case 61 is hermetically fixed to the upper end of the valve body 10 by welding or the like.

The magnet rotor 62 is integrally composed of a cylindrical magnet portion 64 whose outer periphery is magnetized with multiple poles, and a disk portion 65 that closes one end of the magnet portion 64. The magnet rotor 62 is fixed to the drive shaft 30 via a metal fitting 66 that is integrally molded in the center of the disk portion 65. This allows the magnet rotor 62 to be rotatable around the axis L of the drive shaft 30 within the case 61. The drive shaft 30 is the rotation axis of the magnet rotor 62.

The stator coil is disposed on the outer circumferential surface of the case 61, and when a pulse signal is applied to the stator coil, the magnet rotor 62 rotates according to the number of pulses. The stator coil corresponds to the stepping motor 60.

When the magnet rotor 62 rotates, the drive shaft 30 rotates together with the magnet rotor 62, and the screw feed action of the male thread portion 31a and the female thread portion 23a (screw feed mechanism portion) causes the drive shaft 30 to move in the direction of the axis L, and the valve body portion 40 advances and retreats relative to the valve port 11a. This changes the opening of the valve port 11a with respect to the valve seat, and controls the flow rate of the fluid flowing from the first joint pipe 1 to the second joint pipe 2 (or from the second joint pipe 2 to the first joint pipe 1).

<Radial movement suppression means>
As shown in FIG. 1B, the radial movement suppression means 70a includes an abutment member 71a made of a resin-based material having high slipperiness, a biasing member 72a made of a C-ring (C-shaped), a mounting hole 75a that communicates the inner and outer peripheral surfaces of the holder part 21 in a direction perpendicular to the axis L via a step, and a circumferential mounting groove 76a that is formed continuously with the outer peripheral surface of the holder part 21. The abutment member 71a has a flat mushroom shape when viewed from the axis L direction. In this embodiment, the abutment member 71a is preferably made of a resin-based material such as polyphenylene sulfide (PPS) containing fluorine or the like. The abutment member 71a in this embodiment has a flat mushroom shape, but is not limited thereto, and may have any shape that fits the mounting hole 75a having a step.

<Assembly of radial movement suppression means>
1C, when the abutting member 71a is accommodated in the mounting hole 75a, the amount of protrusion B of the abutting member 71a into the circumferential mounting groove 76a is set to be larger than the gap _A1 (e.g., about 0.03 to 0.10 mm on one side) between the guide portion 32 and the bearing hole 24. Therefore, by mounting the biasing member 72a in the circumferential mounting groove 76a with the abutting member 71a accommodated in the mounting hole 75a, a biasing force _F1 in a direction perpendicular to the axis L is generated on the guide portion 32 via the abutting member 71a, and the drive shaft 30 can be moved by the gap A between the guide portion 32 and the guide portion 32. This biasing force _F1 is set to be larger than the magnetic attraction force of the stepping motor 60, so that the drive shaft 30 is not rotated or swung by the magnetic attraction force. In addition, the screw backlash C (see C ₁ +C ₂ in FIG. 1(d)) of the screw feed mechanism is larger than the gap A (see 2×A ₁ in FIG. 1(c)) between the guide portion 32 and the bearing hole 24. Therefore, as shown in FIG. 1(d), when the male screw portion 31a is urged in a direction perpendicular to the axis L via the guide portion 32, the radial movement suppression means 70a can constantly maintain a slight gap C ₁ in the radial direction without rotating or swinging the male screw portion 31a relative to the female screw portion 23a. At this time, the flanks of the screw feed mechanism are in contact with each other so that the contact area does not change. Therefore, in addition to the centrifugal force, which is a radial component force having stationarity, the axial component force having stationarity acts simultaneously on the screw feed mechanism, so that it is possible to suppress the collision between the flanks of the screw feed mechanism. Therefore, the drive shaft 30 is corrected from a complex spiral motion in which the axis center is shifted and moves in the axis L direction while rotating and swinging, as in the conventional technology, to a rotational axial motion in which the drive shaft 30 moves in the axis L direction while rotating. In this embodiment, the abutment member 71a has a contact portion that is planar when viewed from the direction of the axis L, and the contact state between the abutment member 71a and the guide portion 32 is line contact, but this is not limiting, and for example, the abutment member 71a may have a semicylindrical contact portion, and the contact state between the abutment member 71a and the guide portion 32 may be line contact. In this manner, in this embodiment, by making the contact state between the abutment member 71a and the guide portion 32 line contact, the guide portion 32 can be pressed horizontally and stably by the entire height of the abutment member 71a through this line contact extending in the direction of the axis L.

The motor-operated valve 100a of this embodiment maintains a small gap _C1 in the radial direction in the screw feed mechanism by the radial movement suppression means 70a, and solves the conventional problem (collision in the screw feed mechanism), so that low operating noise can be achieved even in a dry (oil-out) state. Furthermore, the radial movement suppression means 70a in this embodiment can constantly urge the male threaded portion 31a in the radial direction against the female threaded portion 23a even when the drive shaft 30 is in any lift position. Furthermore, since the radial movement suppression means 70a in this embodiment is provided between the bearing hole 24 and the guide portion 32, the abutment member 71a and the male threaded portion 31a do not overlap, and the movement of the drive shaft 30 in the axis L direction is not affected. Furthermore, the radial movement suppression means 70a in this embodiment urges the male threaded portion 31a in the direction perpendicular to the axis L via the abutment member 71a that contacts the drive shaft 30, so that a space-saving and simple configuration can be achieved. Furthermore, the radial movement suppression means 70a in this embodiment has the contact member 71a disposed opposite the outer circumferential surface of the guide portion 32 and the biasing member 72a applies a biasing force to the contact member 71a, so that it can be introduced to a conventional motor-operated valve without making any major changes. In addition, in this embodiment, the contact member 71a and the biasing member 72a have a relatively long contact area along the circumferential direction, so that the biasing force of the biasing member 72a can be reliably transmitted to the contact member 71a.

(Modification 1 of the first embodiment)
Here, the radial movement suppressing means 70a1 to 70a7 according to the first modified example of the first embodiment will be described with reference to Figures 2 and 3. The radial movement suppressing means 70a1 to 70a7 in the first modified example of the first embodiment differ from the radial movement suppressing means 70a in the first embodiment in that the biasing members 72a1 to 72a7 are provided with rotation stoppers, respectively, but the other basic configurations are the same as those of the first embodiment. Here, the same members are given the same reference numerals, and duplicated descriptions are omitted. In addition, in the holder portion 21 in this embodiment, a radial groove 21a is formed on the opposite side of the mounting hole 75a with respect to the axis L in order to stabilize sink marks during resin molding and obtain the desired shape and dimensions.

As shown in FIG. 1(b), the radial movement suppression means 70a in the first embodiment is configured to mount a biasing member 72a made of a C-ring in a circumferential mounting groove 76a (see FIG. 1(c)) formed continuously on the outer circumferential surface of the holder portion 21 with the abutment member 71a housed in the mounting hole 75a. As a result, the biasing member 72a is held in the circumferential mounting groove 76a without any restriction on its circumferential movement, and therefore there is a risk that the biasing member 72a may rotate in the circumferential direction due to vibrations that occur when the motor-operated valve 100a is driven.

The biasing force of the biasing member 72a, which is made of a C-ring, against the abutment member 71a is maximum when the cutout of the C-ring is in a position opposite the abutment member 71a across the axis L (see FIG. 1(a)), and is minimum when the cutout of the C-ring is in a position facing the abutment member 71a. Therefore, due to vibrations that occur during operation, the biasing member 72a rotates in the circumferential direction relative to the abutment member 71a, that is, the circumferential position of the cutout changes, and this changes the biasing force of the biasing member 72a against the abutment member 71a, and there is a risk that the pressing force of the guide part 32 against the bearing hole 24 will not be stable.

In contrast, the radial movement suppression means 70a1 to 70a7 in the modified example 1 of the first embodiment are provided with rotation stoppers for the urging members 72a1 to 72a7, respectively. Note that, although details will be described later, the radial movement suppression means 70a1 to 70a7 in the modified example 1 of the first embodiment are broadly divided into radial movement suppression means 70a1 to 70a3 (provided on the abutment members 71a1 to 71a3) in the modified example 1-1 of the first embodiment and radial movement suppression means 70a4 to 70a7 (provided on the holder portion 21) in the modified example 1-2 of the first embodiment, depending on the form of the rotation stopper for the urging members 72a1 to 72a3. Below, the modified example 1 of the first embodiment will be described in the order of the modified example 1-1 of the first embodiment and the modified example 1-2 of the first embodiment.

(Modification 1-1 of the first embodiment)
As shown in Figures 2(a) to (c), the radial movement suppression means 70a1 to 70a3 in variant 1-1 of the first embodiment is configured by providing rotation stoppers for the urging members 72a1 to 72a3 on the abutment members 71a1 to 71a3, respectively, so that the urging members 72a1 to 72a3 are indirectly held to the holder portion 21 via the abutment members 71a1 to 71a3, and consists of three forms, variant 1-1(1) to variant 1-1(3).

(Modification 1-1(1))
As shown in FIG. 2(a), the radial movement suppressing means 70a1 in the modified example 1-1(1) of the first embodiment includes an abutting member 71a1 having a protrusion (rotation stopper) 71a1p protruding in the outer diameter direction at the radially outer central portion, and a biasing member 72a1 having a pair of notched ends (rotation stopper engagement portions) (pair of ends) 72a1n extending in the circumferential direction. The radial movement suppressing means 70a1 is assembled by mounting the biasing member 72a1 in a circumferential mounting groove 76a formed continuously on the outer circumferential surface of the holder portion 21 with the abutting member 71a1 accommodated in the mounting hole 75a. At this time, the protrusion 71a1p of the abutting member 71a1 is disposed so as to be positioned between the pair of notched ends 72a1n of the biasing member 72a1. In this embodiment, the pair of notched ends 72a1n and the protrusion 71a1p are engaged so that at least one of them has a slight gap. This is because if the pair of cutout ends 72a1n and the protrusion 71a1p were to be abutted without leaving a gap between them, the pair of cutout ends 72a1n would open in a direction away from each other, thereby weakening the radial biasing force of the biasing member 72a1.

As described above, in the radial movement suppression means 70a1 of this embodiment, even if the biasing member 72a1 tries to rotate circumferentially in the circumferential mounting groove 76a due to vibrations occurring during operation, the pair of notched ends 72a1n interfere with the protrusions 71a1p, and the circumferential position of the pair of notched ends 72a1n is maintained. This maintains the biasing force of the biasing member 72a1 against the abutting member 71a1, and the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. In addition, in this embodiment, the rotation of the biasing member 72a1 can be stopped relatively easily by changing only the shapes of the abutting member 71a1 and the biasing member 72a1. Furthermore, in this embodiment, since the inner radius of the biasing member 72a1 is larger than the outer radius of the abutting member 71a1, the pair of notched ends 72a1n are in point contact with the outer circumferential surface of the abutting member 71a1 at two points, and therefore can be biased in a stable state. The outer radius of the abutting member 71a1 and the inner radius of the biasing member 72a1 may be the same, in which case there will be two circumferential line contacts. In this embodiment, the biasing member 72a1 is made of round wire, so there will be two point contacts, but the biasing member 72a1 may be made of square wire, in which case there will be two line contacts in the axis L direction.

(Modification 1-1(2))
As shown in FIG. 2B, the radial movement suppressing means 70a2 in the modified example 1-1(2) of the first embodiment includes an abutting member 71a2 having a recessed portion (rotation stopper portion) 71a2d recessed in the inner diameter direction in the central portion of the outer circumferential surface, and a biasing member 72a2 having a pair of radial folded end portions (rotation stopper engagement portions) (pair of end portions) 72a2f folded in the inner diameter direction. The radial movement suppressing means 70a2 is assembled by mounting the biasing member 72a2 in a circumferential mounting groove 76a formed continuously on the outer circumferential surface of the holder portion 21 with the abutting member 71a2 housed in the mounting hole 75a. At this time, the pair of radial folded end portions 72a2f of the biasing member 72a2 are arranged to be engaged with the recessed portion 71a2d of the abutting member 71a1.

Therefore, in the radial movement suppression means 70a2 of this embodiment, even if the biasing member 72a2 tries to rotate circumferentially in the circumferential mounting groove 76a due to vibrations occurring during operation, the pair of radial folded end portions 72a2f interfere with the recessed portion 71a2d, and the circumferential position of the pair of radial folded end portions 72a2f is maintained. This maintains the biasing force of the biasing member 72a2 against the abutment member 71a2, and the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. In addition, in this embodiment, as in modified example 1-1(1), the rotation of the biasing member 72a2 can be stopped relatively easily by changing only the shapes of the abutment member 71a2 and the biasing member 72a2. Furthermore, in this embodiment, the inner radius of the biasing member 72a2 is larger than the outer radius of the abutting member 71a2, so the biasing member 72a2 makes point contact with the outer circumferential surface of the abutting member 71a2 at two points, and the pair of radially folded end portions 72a2f engage with the recessed portion 71a2d, so the biasing member 72a2 can be biased in a more stable state. The outer radius of the abutting member 71a2 and the inner radius of the biasing member 72a2 may be the same, in which case there will be line contact in the circumferential direction at two points. In this embodiment, the biasing member 72a2 is formed from a round wire material, so there will be two point contacts, but the biasing member 72a2 may be formed from a square wire material, in which case there will be line contact in the axial direction at two points.

(Modification 1-1(3))
As shown in FIG. 2(c), the radial movement suppressing means 70a3 in the modified example 1-1(3) of the first embodiment includes an abutting member 71a3 having a straight portion (rotation stopper portion) 71a3s on the outer circumferential surface, and a biasing member 72a3 having a pair of linearly bent ends (rotation stopper engagement portion) (pair of ends) 72a3b that are bent into a linear shape. The radial movement suppressing means 70a3 is assembled by mounting the biasing member 72a3 in a circumferential mounting groove 76a formed continuously on the outer circumferential surface of the holder portion 21 with the abutting member 71a3 housed in the mounting hole 75a. At this time, the pair of linearly bent ends 72a3b of the biasing member 72a3 are arranged to be engaged with the straight portion 71a3s of the abutting member 71a3.

Therefore, in the radial movement suppression means 70a3 of this embodiment, even if the biasing member 72a3 tries to rotate in the circumferential direction in the circumferential mounting groove 76a due to vibrations occurring during operation, the pair of linearly bent end portions 72a3b interfere with the straight portion 71a3s, and the circumferential position of the pair of linearly bent end portions 72a3b is maintained. This maintains the biasing force of the biasing member 72a3 against the abutting member 71a3, and the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. In addition, in this embodiment, as in the modified example 1-1 (2), the rotation of the biasing member 72a2 can be stopped relatively easily by changing only the shapes of the abutting member 71a3 and the biasing member 72a3. Furthermore, in the biasing member 72a3 of this embodiment, the pair of linearly bent end portions 72a3b are in line contact with the straight portion 71a3s at two points and are engaged in the same direction toward the axis L, so that the biasing member 72a2 can be biased in a more stable state. In addition, the contact member 71a3 of this embodiment can be made smaller and lighter than the contact member 71a2 of modification 1-1(2). In this embodiment, the biasing member 72a3 is made of round wire material, so there are two line contacts, but the biasing member 72a3 may be made of rectangular wire material, in which case there will be surface contact with a width in the direction of the axis L at two points.

(Modification 1-2 of the first embodiment)
3(a) to 3(h), the radial movement suppressing means 70a4 to 70a7 in the modified example 1-2 of the first embodiment are configured such that the rotation stoppers for the urging members 72a4 to 72a7 are provided in the holder portion 21, respectively, so that the urging members 72a4 to 72a7 are directly held in the holder portion 21, and there are four configurations from modified example 1-2(1) to modified example 1-2(4). Note that the abutting member 71a in the modified example 1-2 of the first embodiment is the same as the abutting member 71a in the first embodiment (see FIG. 1(b)).

(Modification 1-2(1))
As shown in Figures 3(a) to (b), the radial movement suppression means 70a4 in the modified example 1-2(1) of the first embodiment includes a protrusion (rotation stopper) 21b formed on the outer circumferential surface of the holder portion 21, a circumferential mounting groove 76a4 discontinuously formed on the outer circumferential surface of the holder portion 21 by the protrusion 21b, and a biasing member 72a4 having a pair of notched ends (rotation stopper engagement portions) (pair of ends) 72a4n extending in the circumferential direction. The assembly of the radial movement suppression means 70a4 is performed by mounting the biasing member 72a4 in the circumferential mounting groove 76a4 discontinuously formed on the outer circumferential surface of the holder portion 21 with the abutting member 71a accommodated in the mounting hole 75a. At this time, the protrusion 21b of the holder portion 21 is arranged to be located between the pair of notched ends 72a4n of the biasing member 72a4. In this embodiment, for the same reason as in the above-described modified example 1-1(1), the pair of cutout ends 72a4n and the protrusion 21b are engaged so that a slight gap is provided on at least one of them. The protrusion 21b of the holder part 21 in this embodiment is provided at a position shifted by approximately 90° in the circumferential direction with respect to the mounting hole 75a, but is not limited thereto, and may be located anywhere in the circumferential direction as long as it is spaced apart from the mounting hole 75a and the radial groove 21a.

Therefore, in the radial movement suppression means 70a4 of this embodiment, even if the biasing member 72a4 tries to rotate circumferentially in the circumferential mounting groove 76a4 due to vibrations occurring during operation, the pair of notched ends 72a4n interfere with the protrusion 21b, and the circumferential position of the pair of notched ends 72a4n is maintained. As a result, the biasing force of the biasing member 72a4 against the abutting member 71a is maintained, and the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. In addition, in this embodiment, by changing only the shapes of the holder portion 21 and the biasing member 72a4, the rotation of the biasing member 72a4 can be stopped relatively easily. Furthermore, in the biasing member 72a4 of this embodiment, since the pair of notched ends 72a4n are not in a position facing the abutting member 71a, as already described, the abutting member 71a can be biased with a relatively large biasing force. In this embodiment, the biasing member 72a4 is in point contact with the outer apex of the abutment member 71a, as in modified example 1-1(1), but this is not limited thereto. The outer periphery radius of the abutment member 71a and the inner periphery radius of the biasing member 72a4 may be the same, and the biasing member 72a4 may be in line contact with the entire outer periphery surface of the abutment member 71a. In this way, biasing can be performed in a stable state.

(Modification 1-2(2))
3(c) to (d), the radial movement suppression means 70a5 in the modified example 1-2(2) of the first embodiment includes a circumferential mounting groove 76a formed continuously on the outer circumferential surface of the holder portion 21, a pin hole 21c that crosses the circumferential mounting groove 76a in the axis L direction and opens upward, a stopper pin (rotation stopper portion) 21d press-fitted into the pin hole 21c, and a biasing member 72a5 having a pair of notched ends (rotation stopper engagement portion) (pair of ends) 72a5n extending in the circumferential direction. The radial movement suppression means 70a5 is assembled by mounting the biasing member 72a5 in the circumferential mounting groove 76a formed continuously on the outer circumferential surface of the holder portion 21 with the abutting member 71a accommodated in the mounting hole 75a. At this time, the circumferential positioning of the urging member 72a5 is performed by arranging the gap between the pair of cutout ends 72a5n so as to overlap the pin hole 21c when viewed from the axis L direction, and then press-fitting the stopper pin 21d into the pin hole 21c. By positioning the circumferential positioning of the urging member 72a5 in this manner, the circumferential mounting groove 76a formed on the outer circumferential surface of the holder portion 21 becomes discontinuous in the circumferential direction. In this embodiment, for the same reason as in the above-mentioned modified example 1-1(1), the pair of cutout ends 72a5n and the stopper pin 21d are engaged so that at least one of them has a slight gap. In this embodiment, the stopper pin 21d is provided at a position shifted by approximately 90° in the circumferential direction with respect to the mounting hole 75a, but this is not limited thereto, and may be located anywhere in the circumferential direction as long as it is spaced apart from the mounting hole 75a and the radial groove 21a. Further, in the present embodiment, the stopper pin 21d is press-fitted into the pin hole 21c, but this is not limiting and, for example, the stopper pin 21d may be inserted into the pin hole 21c.

Therefore, in the radial movement suppression means 70a5 of this embodiment, even if the biasing member 72a5 tries to rotate circumferentially in the circumferential mounting groove 76a due to vibrations occurring during operation, the pair of notched ends 72a5n interfere with the stopper pin 21d, and the circumferential position of the pair of notched ends 72a5n is maintained. This maintains the biasing force of the biasing member 72a5 against the abutting member 71a, and the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. In this embodiment, as in the modified example 1-2(1), the rotation of the biasing member 72a5 can be stopped relatively easily by changing only the shapes of the holder portion 21 and the biasing member 72a5, and the biasing member 72a5 can bias the abutting member 71a with a relatively large biasing force because the pair of notched ends 72a5n are not in a position facing the abutting member 71a. In this embodiment, the biasing member 72a5 is in point contact with the outer apex of the abutment member 71a, as in modified example 1-1(1), but this is not limited thereto. The outer periphery radius of the abutment member 71a and the inner periphery radius of the biasing member 72a5 may be the same, and the biasing member 72a5 may be in line contact with the entire outer periphery surface of the abutment member 71a. In this way, biasing can be performed in a stable state.

(Modification 1-2(3))
As shown in FIG. 3(e)-(f), the radial movement suppressing means 70a6 in the modified example 1-2(3) of the first embodiment includes a radial groove (rotation stopper) 21a formed in the holder portion 21, and a biasing member 72a6 having a pair of radial folded end portions (rotation stopper engagement portions) (pair of end portions) 72a6f folded back in the inward radial direction. The radial groove 21a is continuously connected to the circumferential mounting groove 76a radially inward. Here, the radial movement suppressing means 70a6 is assembled by mounting the biasing member 72a6 in the circumferential mounting groove 76a formed continuously on the outer circumferential surface of the holder portion 21 with the abutting member 71a accommodated in the mounting hole 75a. At this time, the pair of radial folded end portions 72a6f of the biasing member 72a6 are arranged to be engaged with the radial groove 21a of the holder portion 21.

Therefore, in the radial movement suppression means 70a6 of this embodiment, even if the biasing member 72a6 tries to rotate circumferentially in the circumferential mounting groove 76a due to vibrations occurring during operation, the pair of radial folded end portions 72a6f interfere with the radial groove 21a, and the circumferential position of the pair of radial folded end portions 72a6f is maintained. As a result, the biasing force of the biasing member 72a6 against the abutting member 71a is maintained, and the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. In this embodiment, the rotation of the biasing member 72a6 can be stopped relatively easily by changing only the shape of the biasing member 72a2 and using the radial groove 21a for sink measures. Furthermore, in the biasing member 72a6 of this embodiment, as in the modified example 1-2(1), the pair of radial folded end portions 72a6f are not positioned opposite the abutting member 71a, so that the abutting member 71a can be biased with a relatively large biasing force. In this embodiment, the biasing member 72a6 is in point contact with the outer apex of the abutment member 71a, as in modified example 1-1(1), but this is not limited thereto. The outer periphery radius of the abutment member 71a and the inner periphery radius of the biasing member 72a6 may be the same, and the biasing member 72a6 may be in line contact with the entire outer periphery surface of the abutment member 71a. In this way, biasing can be performed in a stable state.

(Modification 1-2(4))
As shown in Figures 3(g) to (h), the radial movement suppression means 70a7 in the modified example 1-2(4) of the first embodiment includes a circumferential mounting groove 76a formed continuously on the outer peripheral surface of the holder portion 21, an axial groove (rotation stopper portion) 21e formed on the outer peripheral surface of the holder portion 21 so as to cross the circumferential mounting groove 76a in the axial line L direction, and a biasing member 72a7 having a pair of axially bent ends (rotation stopper engagement portion) (pair of ends) 72a7b bent in a linear shape in the axial line L direction. The axial groove 21e is continuously connected to the circumferential mounting groove 76a in the axial line L direction. Here, the radial movement suppression means 70a7 is assembled by mounting the biasing member 72a7 in the circumferential mounting groove 76a formed continuously on the outer peripheral surface of the holder portion 21 with the abutting member 71a accommodated in the mounting hole 75a. At this time, the pair of axially bent ends 72a7b of the urging member 72a7 are arranged to be engaged with the axial groove 21e of the holder part 21. In this embodiment, the pair of axially bent ends 72a7b are both bent downward (see solid line in FIG. 3(h)), but this is not limited thereto. For example, each of the pair of axially bent ends 72a7b may be bent either upward (see dashed line in FIG. 3(h)) or downward. In this embodiment, the axial groove 21e is provided at a position shifted by approximately 90° in the circumferential direction with respect to the mounting hole 75a, but this is not limited thereto. For example, the axial groove 21e may be located anywhere in the circumferential direction away from the mounting hole 75a and the radial groove 21a.

Therefore, in the radial movement suppression means 70a7 of this embodiment, even if the biasing member 72a7 tries to rotate circumferentially in the circumferential mounting groove 76a due to vibrations occurring during operation, the pair of axially bent ends 72a7b interfere with the axial groove 21e, and the circumferential position of the pair of axially bent ends 72a7b is maintained. This maintains the biasing force of the biasing member 72a7 against the abutment member 71a, and the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. In this embodiment, as in the modified example 1-2(1), the rotation of the biasing member 72a7 can be stopped relatively easily by changing only the shapes of the holder portion 21 and the biasing member 72a7, and the biasing member 72a7 can bias the abutment member 71a with a relatively large biasing force because the pair of axially bent ends 72a7b are not in a position facing the abutment member 71a. In this embodiment, the biasing member 72a7 is in point contact with the outer apex of the abutting member 71a, as in modified example 1-1(1), but this is not limited thereto. The outer periphery radius of the abutting member 71a and the inner periphery radius of the biasing member 72a5 may be the same, and the biasing member 72a7 may be in line contact with the entire outer periphery surface of the abutting member 71a. In this way, biasing can be performed in a stable state.

(Modification 2 of the first embodiment)
Here, the radial movement suppressing means 70a1-1 to 70a1-4 according to the modified example 2 of the first embodiment will be described with reference to Figures 4 to 6. The radial movement suppressing means 70a1-1 to 70a1-4 in the modified example 2 of the first embodiment differ from the radial movement suppressing means 70a1 (see Figure 2(a)) in the modified example 1-1(1) of the first embodiment in that the shape of the contact portion of the abutting members 71a1-1 to 71a1-4 with respect to the guide portion 32 is changed, but the other basic configurations are the same as those of the modified example 1-1(1) of the first embodiment. Here, the same members are given the same reference numerals, and duplicated explanations will be omitted. For the sake of explanation, this modified example 2 of the first embodiment is adopted in modified example 1-1(1) of the first embodiment (see FIG. 2(a)). However, it is not limited thereto, and may be adopted in other modified examples 1-1(2) and (3) of the first embodiment (see FIG. 2(b) and FIG. 2(c)), and modified examples 1-2(1) to (4) (FIG. 3(a) to FIG. 3(h)). Note that, although details will be described later, the radial movement suppressing means 70a1-1 to 70a1-4 according to modified example 2 of the first embodiment are roughly divided into radial movement suppressing means 70a1-1, 70a1-2 (stable support form) according to modified example 2-1 of the first embodiment and radial movement suppressing means 70a1-3, 70a1-4 (form for reducing sliding resistance) according to modified example 2-2 of the first embodiment, depending on the shape of the contact portion in the abutting members 71a1-1 to 71a1-4. Hereinafter, the second modification of the first embodiment will be described in the order of a second modification of the first embodiment, a second modification of the first embodiment, and a third modification of the first embodiment.

(Modification 2-1 of the first embodiment)
As shown in FIG. 2A, in the radial movement suppression means 70a1 in the modified example 1-1(1) of the first embodiment, the contact portion of the abutting member 71a1 facing the guide portion 32 has a planar shape when viewed from the axial line L direction, so that the contact state between the abutting member 71a1 and the guide portion 32 is one line contact extending in the axial line L direction. Therefore, the circumferential position of the abutting member 71a1 relative to the guide portion 32 is easily shifted due to vibrations occurring in the operating state, and there is a risk that the circumferential position of the line contact is unstable. As a result, the biasing force of the biasing member 72a1 is biased in a direction that does not pass through the axis of the guide portion 32 via the unstable line contact in the circumferential direction, so that there is a risk that the pressing force of the guide portion 32 against the bearing hole 24 is unstable.

In contrast, the radial movement suppression means 70a1-1, 70a1-2 in modified example 2-1 of the first embodiment have contact portions 71a1c-1, 71a1c-2 in the abutment members 71a1-1, 71a1-2 that have stable support configurations, and are comprised of two configurations, modified example 2-1(1) and modified example 2-1(2).

(Modification 2-1(1))
As shown in FIG. 4(a), the radial movement suppression means 70a1-1 in the modified example 2-1(1) of the first embodiment has an inverted arc shape in which the contact portion 71a1c-1 of the contact member 71a1-1 facing the guide portion 32 is arranged in close proximity to the outer peripheral surface of the guide portion 32 when viewed from the axis L direction. Therefore, as shown in FIG. 4(b), the contact state between the contact member 71a1-1 and the guide portion 32 is one line contact Ca-1 extending in the axis L direction. In this embodiment, the curvature radius of the contact portion 71a1c-1 is set to be larger than the curvature radius of the guide portion 32, and more preferably, is set to be slightly larger than the curvature radius of the guide portion 32. In addition, the curvature radius of the contact portion 71a1c-1 and the guide portion 32 may be the same, and the contact state may be surface contact.

Therefore, in the radial movement suppression means 70a1-1 of this embodiment, even if the circumferential position of the abutment member 71a1-1 is slightly shifted with respect to the guide portion 32 due to vibrations occurring during operation, the guide portion 32 easily returns to the apex of the inverted arc-shaped contact portion 71a1c-1, and the amount of movement of the line contact Ca-1 can be suppressed to be smaller than that of the radial movement suppression means 70a1 in modified example 1-1(1) of the first embodiment (see FIG. 2(a)). As a result, the biasing force of the biasing member 72a1 is biased in the direction near the axis of the guide portion 32 via the abutment member 71a1-1, so that the pressing force of the guide portion 32 against the bearing hole 24 can be maintained in a more stable state. Also, in this embodiment, as in the first embodiment, the contact state between the contact member 71a1-1 and the guide portion 32 is line contact, and through this line contact extending in the direction of the axis L, the entire height of the contact member 71a1-1 can press the guide portion 32 horizontally in a stable state.

(Modification 2-1(2))
As shown in Fig. 4(c), in the radial movement suppression means 70a1-2 in the modified example 2-1(2) of the first embodiment, when viewed from the axis L direction, a contact portion 71a1c-2 of the abutting member 71a1-2 facing the guide portion 32 has a tapered shape recessed into the outer circumferential surface of the guide portion 32. Therefore, as shown in Fig. 4(d), the contact state between the abutting member 71a1-2 and the guide portion 32 is two line contacts Ca-2 extending in the axis L direction with the axis L in between.

Therefore, in the radial movement suppression means 70a1-2 of this embodiment, even if the circumferential position of the abutment member 71a1-2 tends to shift slightly relative to the guide portion 32 due to vibrations occurring during operation, the two line contacts Ca-2 are stably supported, so the amount of movement of the two line contacts Ca-2 can be kept extremely small compared to the radial movement suppression means 70a1 in modified example 1-1(1) of the first embodiment (see FIG. 2(a)). As a result, the biasing force of the biasing member 72a1 is biased approximately in the axial direction of the guide portion 32 via the abutment member 71a1-2, so the pressing force of the guide portion 32 against the bearing hole 24 can be maintained in an even more stable state. Also, in this embodiment, as in the first embodiment, the contact state between the contact member 71a1-2 and the guide portion 32 is line contact, and through this line contact extending in the direction of the axis L, the entire height of the contact member 71a1-2 can press the guide portion 32 horizontally in a stable state.

Here, the condition for preventing the pair of edge portions E1, E2 of the contact portion 71a1c-2 from contacting the guide portion 32 will be described with reference to FIG. 5. First, straight lines are drawn from the linear edge portions E1, E2 formed on the outer edge portion of the contact portion 71a1c-2 to the center O of the guide portion 32, and the angle formed by ∠E1OE2 is defined as α. The angle α formed by ∠E1OE2 is calculated by 2×Sin ⁻¹ (Lb/Da). Here, Da indicates the diameter of the guide portion 32, and Lb indicates the taper width of the contact portion 71a1c-2. In addition, the apex of the taper shape of the contact portion 71a1c-2 is defined as O1, and the apex angle formed by ∠E1O1E2 is defined as the taper angle θ.

Here, for example, when θ=180-α, the sum of the angle formed by ∠OE1O1 and the angle formed by ∠OE2O1 is 180 (°), that is, the angles formed by ∠OE1O1 and ∠OE2O1 are each 90 (°), so the linear edge portions E1 and E2 become the contact points of the guide portion 32. Therefore, in this embodiment, by satisfying the following (Equation 1), the contact position of the guide portion 32 with the tapered contact portion 71a1c-2 can be set on the tapered surface on the vertex O1 side that does not include the linear edge portions E1 and E2. As a result, it is possible to prevent the linear edge portions E1 and E2 from contacting the cylindrical guide portion 32.

θ>180−α (Formula 1)
In formula 1, θ>180-2×Sin ^-1 (Lb/Da). Therefore, by setting the diameter Da of guide portion 32 and the taper width Lb of contact portion 71a1c-2 so that the taper angle θ of contact portion 71a1c-2 satisfies formula 1, it is possible to prevent deformation or wear of linear edge portions E1, E2 due to contact caused by being pressed by guide portion 32, and thus to prevent changes in the pressing force of guide portion 32 against bearing hole 24.

(Modification 2-1 of the first embodiment)
As shown in FIG. 2(a) , in the radial movement suppression means 70a1 of the first embodiment, the contact state between the abutment member 71a1 and the guide portion 32 is a single line contact extending in the axial direction L, so that the sliding resistance of the rotating guide portion 32 against the abutment member 71a1 becomes large, and there is a risk that the driving force of the stepping motor 60 cannot be efficiently transmitted to the valve body 42.

In contrast, the radial movement suppression means 70a1-3, 70a1-4 in modified example 2-2 of the first embodiment have contact portions 71a1c-3, 71a1c-4 in the abutment members 71a1-3, 71a1-4 that have a configuration that reduces sliding resistance, and are comprised of two configurations, modified example 2-2(1) and modified example 2-2(2).

(Modification 2-2(1))
As shown in Fig. 6(a), in the radial movement suppression means 70a1-3 in the modified example 2-2(1) of the first embodiment, a contact portion 71a1c-3 of the abutment member 71a1-3 facing the guide portion 32 has a spherical shape when viewed from the axis L direction. Therefore, as shown in Fig. 6(b), the contact state between the abutment member 71a1-3 and the guide portion 32 is one point contact Ca-3.

Therefore, in the radial movement suppression means 70a1-3 of this embodiment, the contact member 71a1-3 is in one point contact Ca-3 with the guide portion 32, so that the sliding resistance of the rotating guide portion 32 with respect to the contact member 71a1-3 can be made relatively small, and as a result, the driving force of the stepping motor 60 can be efficiently transmitted to the valve body 42. Note that the spherical contact portion 71a1c-3 in this embodiment is fixed to the contact member 71a1-3, but this is not limiting, and for example, by adopting something that is held rotatably, such as a bearing, the sliding resistance can be further reduced.

(Modification 2-2(2))
6(a), in the radial movement suppression means 70a1-3 in the modified example 2-2(1) of the first embodiment, the contact state between the contact member 71a1-3 and the guide portion 32 is one point contact Ca-3, so that the contact member 71a1-3 may easily tilt with respect to the horizontal direction. As a result, the biasing force of the biasing member 72a1 is biased in a direction not perpendicular to the axis L of the guide portion 32 via the contact member 71a1-3, so that the pressing force of the guide portion 32 against the bearing hole 24 may not be stabilized.

In contrast, as shown in Figures 6(c) and (d), in the radial movement suppression means 70a1-4 in modified example 2-2(2) of the first embodiment, when viewed from the axis L direction, the contact portion 71a1c-4 of the abutment member 71a1-4 facing the guide portion 32 has two spherical shapes aligned along the axis L direction. Therefore, as shown in Figure 6(d), the contact state between the abutment member 71a1-4 and the guide portion 32 is two point contacts Ca-4 aligned along the axis L direction.

In this way, in the radial movement suppression means 70a1-4 of this embodiment, the abutment member 71a1-4 is two point contacts Ca-4 aligned along the axis L direction with respect to the guide portion 32, so the abutment member 71a1-4 does not tilt with respect to the horizontal direction. Therefore, the biasing force of the biasing member 72a1 is biased only in the direction perpendicular to the axis L of the guide portion 32 via the abutment member 71a1-4, so that the pressing force of the guide portion 32 against the bearing hole 24 can be stabilized. Also, in this embodiment, as in the modified example 2-2(1), the sliding resistance of the rotating guide portion 32 against the abutment member 71a1-4 can be made relatively small, and as a result, the driving force of the stepping motor 60 can be efficiently transmitted to the valve body 42. In this embodiment, the spherical contact portion 71a1c-4 is fixed to the abutment member 71a1-4, but this is not limiting. For example, the sliding resistance can be further reduced by using a rotatable support such as a bearing.

(Modification 3 of the first embodiment)
Here, the radial movement suppressing means 70a8, 70a9 according to the modified example 3 of the first embodiment will be described with reference to FIG. 7 to FIG. 9. The radial movement suppressing means 70a8, 70a9 in the modified example 3 of the first embodiment differs from the radial movement suppressing means 70a4 in the modified example 1-2(1) of the first embodiment (see FIG. 3(a)) in that the radial movement suppressing means 70a8, 70a9 in the modified example 3 of the first embodiment is mainly provided with a configuration for suppressing backlash in the mounting holes 75a, 75a'' of the abutting members 71a', 71a'', but the other basic configuration is the same as that of the modified example 1-2(1) of the first embodiment. Here, the same members are given the same reference numerals and duplicated explanations are omitted. In addition, in the holder portion 21 in this embodiment, as shown in FIG. 7 and FIG. 8, radial grooves 21a, 21a'' are formed on the opposite side of the mounting holes 75a, 75a'' with respect to the axis L in order to stabilize sink marks during resin molding and obtain the desired shape and dimensions.

As shown in FIG. 3(a), in the radial movement suppression means 70a4 in the modified example 1-2(1) of the first embodiment, the inner peripheral surface and outer peripheral apex of the abutment member 71a contact the guide portion 32 and the biasing member 72a4 on a straight line in a direction perpendicular to the axis L in a horizontal plane (left-right direction in FIG. 3(a)). In other words, the biasing force F1 (see FIG. 1(b)) is along this straight line. Here, in order to make the assembly smooth, the radial movement suppression means 70a4 accommodates the abutment member 71a in the mounting hole 75a with a slight gap between the abutment member 71a and the mounting hole 75a in the circumferential direction and the axial direction L. Due to this assembly gap, the abutment member 71a moves in conjunction with the guide portion 32 every time the guide portion 32 rotates and moves in the axial direction L, and tilts relative to the axial direction L and in the axial direction L. As a result, the direction of the biasing force F1 was not constant, and there was a risk that the abutting member 71a would not be able to press the guide portion 32 in a stable manner.

In response to this, the radial movement suppression means 70a8, 70a9 in Modification 3 of the first embodiment are provided with a configuration that suppresses backlash within the mounting holes 75a, 75a'' of the abutment members 71a', 71a'', and are made up of two configurations: Modification 3-1 (configuration that suppresses backlash in the circumferential direction) and Modification 3-2 (configuration that suppresses backlash in the axial L direction).

(Variation 3-1)
First, the radial movement suppressing means 70a8 in the modified example 3-1 of the first embodiment has a configuration for suppressing circumferential backlash. Specifically, the radial movement suppressing means 70a8 is provided with an abutting member 71a' having a substantially L-shape, an abutting portion 71a'1 that abuts against the guide portion 32, and an urging portion 71a'2 that extends along the circumferential direction of the outer circumferential surface of the holder portion 21 so as to be spaced apart from the axis L71a' of the abutting portion 71a'1 and abuts against the urging member 72a4. The radial movement suppressing means 70a8 is assembled by mounting the urging member 72a4 in the circumferential mounting groove 76a4 that is discontinuously formed on the outer circumferential surface of the holder portion 21 with the abutting member 71a' housed in the mounting hole 75a, and arranging the protrusion 21b of the holder portion 21 between a pair of cutout ends 72a4n of the urging member 72a4. At this time, the biasing member 72a4 comes into contact with the biasing portion 71a'2 of the contact member 71a', so that a moment M1 constantly acts on the contact member 71a' in the mounting hole 75a. This moment M1 causes the axis L71a' of the contact portion 71a'1 to tilt with respect to the axis of the mounting hole 75a, and as a result, the contact member 71a' is firmly supported by two contact points (see x marks in the figure) spaced apart in the circumferential direction of the mounting hole 75a, so that rotation in the circumferential direction can be restricted.

For the sake of explanation, modified example 3-1 of this embodiment is based on modified example 1-2(1), and the rotation stopper and rotation stopper engagement portion of the urging member 72a4 are configured as a protrusion 21b and a pair of notched ends 72a4n (see FIG. 3(a)). However, this is not limited thereto, and the rotation stopper and rotation stopper engagement portion of the urging member may be configured as, for example, a stopper pin and a pair of notched ends (see FIG. 3(c)), a radial groove and a pair of radial folded ends (see FIG. 3(e)), or an axial groove and a pair of axial folded ends (see FIG. 3(g)).

Therefore, in the radial movement suppression means 70a8 of this embodiment, the abutment member 71a' is inclined with respect to the direction perpendicular to the axis L and interferes with the mounting hole 75a, so that the circumferential rattle of the abutment member 71a' in the mounting hole 75a can be suppressed. As a result, the abutment member 71a' can press the guide portion 32 in a stable state without being linked to the rotation of the guide portion 32. In addition, in the radial movement suppression means 70a8 of this embodiment, the moment M1 is set to be larger than the moment generated in the abutment member 71a' in conjunction with the rotation of the guide portion 32, so that the abutment member 71a' is firmly supported in the mounting hole 75a even when the guide portion 32 rotates not only clockwise as shown in FIG. 7 but also counterclockwise, that is, even when a moment occurs in a direction that cancels the moment M1.

(Variation 3-2)
In the radial movement suppression means 70a8 in the modified example 3-1 of the first embodiment, the diameter of the biasing member 72a4 is set to be relatively small, so that the biasing member 72a4 may interfere with the female screw stopper (not shown) or the guide rail 26 (see FIG. 1) during assembly in the radial movement suppression means 70a8. Also, in the case of assembling the radial movement suppression means 70a8 after setting the diameter of the biasing member 72a4 to be relatively large, the biasing member 72a4 may interfere with the protrusion 67 of the magnet rotor 62 (see FIG. 1).

In contrast, the radial movement suppressing means 70a9 in the modified example 3-2 of the first embodiment has a configuration that suppresses backlash in the axial L direction and suppresses interference of the biasing member 72a9 with other members during assembly. Specifically, as shown in Figures 8 and 9, the radial movement suppressing means 70a9 includes an abutment member 71a'' that is substantially L-shaped and has an abutment portion 71a''1 that abuts against the guide portion 32, and a biasing portion 71a''2 that extends along the axial L direction of the outer circumferential surface of the holder portion 21 so as to be spaced apart from the axis L71a'' (see Figure 8(b)) of the abutment portion 71a''1 and has a circumferential mounting groove 71a''21 that abuts against the biasing member 72a9. The radial movement suppression means 70a9 includes a protrusion (rotation stopper) 21b" formed on the outer circumferential surface of the holder portion 21, a circumferential mounting groove 76a" discontinuously formed on the outer circumferential surface of the holder portion 21 by the protrusion 21b", a plurality of retaining claws 21f formed on the upper portion of the circumferential mounting groove 76a" on the outer circumferential surface of the holder portion 21, and a biasing member 72a9 having a pair of notched ends (rotation stopper engagement portions) (pair of ends) 72a9n extending in the circumferential direction. The radial movement suppression means 70a9 is assembled by fitting the biasing member 72a9 between the circumferential mounting groove 76a" discontinuously formed on the outer circumferential surface of the holder portion 21 and the circumferential mounting groove 71a"21 of the abutting member 71a" with the abutting member 71a" accommodated in the mounting hole 75a". The biasing member 72a9 is disposed such that the convex portion 21b" of the holder portion 21 is disposed between a pair of cutout ends 72a9n, and the center position Oa of the biasing member 72a9 is shifted from the axis L toward the abutting member 71a" side. Here, the diameter of the biasing member 72a9 is set relatively large, so that it does not interfere with the female thread stopper (not shown) or the guide rail 26. In addition, since the biasing member 72a9 is attached below the ridge 67 of the magnet rotor 62 in the axis L direction, it does not interfere with the ridge 67. At this time, as shown in FIG. 8B, the biasing member 72a9 comes into contact with the biasing portion 71a"2 of the abutting member 71a", so that a moment M2 always acts on the abutting member 71a" in the attachment hole 75a". This moment M2 causes the axis L71a'' of the abutment portion 71a''1 to tilt relative to the axis of the mounting hole 75a'', and as a result, the abutment member 71a'' is firmly supported by two abutment points (see x marks in the figure) spaced apart in the direction of the axis L of the mounting hole 75a'', restricting rotation in the direction of the axis L.

In addition, in modified example 3-2 of this embodiment, the rotation stopper and rotation stopper engagement portion of the urging member 72a9 are configured as a protrusion 21b'' and a pair of notched ends 72a9n. However, this is not limited to this, and the rotation stopper and rotation stopper engagement portion of the urging member may be configured as, for example, a stopper pin and a pair of notched ends (see FIG. 3(c)), a radial groove and a pair of radial folded ends (see FIG. 3(e)), or an axial groove and a pair of axial folded ends (see FIG. 3(g)).

Therefore, in the radial movement suppression means 70a9 of this embodiment, the diameter of the biasing member 72a9 is set relatively large, so that it does not interfere with the support member 20'' or the magnet rotor 62, and therefore the degree of freedom of the biasing height position of the biasing member 72a9 and the ease of assembly can be improved. In addition, in the radial movement suppression means 70a9 of this embodiment, the abutment member 71a'' is inclined with respect to the axis L direction and interferes with the mounting hole 75a'', so that the rattle in the axis L direction of the abutment member 71a'' in the mounting hole 75a'' can be suppressed. As a result, the abutment member 71a' can press the guide part 32 in a stable state without being linked to the movement of the guide part 32 in the axis L direction. In addition, in the radial movement suppression means 70a9 of this embodiment, the moment M2 is set to be greater than the moment generated in the abutting member 71a'' in conjunction with the movement of the guide portion 32 in the axial direction L. Therefore, even if the guide portion 32 moves not only upward but also downward in the axial direction L shown in FIG. 8(b), that is, even if a moment occurs in a direction that cancels out the moment M2, the abutting member 71a'' is firmly supported within the mounting hole 75a''.

In addition, in the modified example 3 of the first embodiment, for the purpose of explanation, the configuration for suppressing the circumferential rattle of the modified example 3-1 and the configuration for suppressing the rattle in the axial L direction of the modified example 3-2 are separately provided. However, this is not limited to the above, and for example, as a configuration for suppressing the rattle in the circumferential and axial L directions, the biasing portion 71a''2 of the abutting member 71a'' in the modified example 3-2 is disposed at an angle to the axis L, so that the axis L71a'' of the abutting portion 71a''1 is disposed in a twisted relationship with the axis of the mounting hole 75a''. As a result, the abutting member 71a'' is firmly supported by two abutting points spaced apart in the axial L direction and circumferential direction of the mounting hole 75a'', so that rotation in the axial L direction and the circumferential direction can be simultaneously restricted.

Second Embodiment
A motor-operated valve 100b according to the second embodiment will be described with reference to Fig. 10. The motor-operated valve 100b according to the second embodiment differs from the motor-operated valve 100a according to the first embodiment in the shapes of the abutment member 71b and the mounting hole 75b, but the other basic configuration is the same as that of the first embodiment. Here, the same components are given the same reference numerals, and duplicated explanations will be omitted. Note that the biasing member 72b and the circumferential mounting groove 76b have the same configuration as the biasing member 72a and the circumferential mounting groove 76a, but are given different reference numerals for convenience.

The radial movement suppression means 70b of the second embodiment includes an abutment member 71b made of a resin-based material with high slipperiness, a biasing member 72b made of a C-ring, an attachment hole 75b that connects the inner and outer peripheral surfaces of the holder part 21 with the same diameter in the direction perpendicular to the axis L, and a circumferential attachment groove 76b formed continuously on the outer peripheral surface of the holder part 21. The abutment member 71b has an oblong shape. In this embodiment, the abutment member 71b is preferably made of a resin-based material such as polyphenylene sulfide (PPS) containing fluorine or the like. The abutment member 71b in this embodiment has an oblong shape, but is not limited to this and may have any shape that fits the attachment hole 75b with the same diameter.

<Assembly of radial movement suppression means>
10, by mounting the biasing member 72b in the circumferential mounting groove 76b with the abutting member 71b housed in the mounting hole 75b, a biasing force _F2 in a direction perpendicular to the axis L is generated on the guide portion 32 via the abutting member 71b. Similar to the biasing force _F1 in the first embodiment, this biasing force _F2 is set to be greater than the magnetic attraction force of the stepping motor 60. Also, similar to the radial movement suppressing means 70a in the first embodiment, the radial movement suppressing means 70b can constantly maintain a slight gap between the male thread portion 31a and the female thread portion 23a in the radial direction.

In this way, in the motor-operated valve 100b according to the second embodiment, by adopting the radial movement suppression means 70b instead of the radial movement suppression means 70a, in addition to the same effect as the first embodiment (low operating noise), the shape of the abutment member 71b and the mounting hole 75b can be simplified, thereby reducing costs.

Third Embodiment
A motor-operated valve 100c according to the third embodiment will be described with reference to Fig. 11. The motor-operated valve 100c according to the third embodiment differs from the motor-operated valve 100a according to the first embodiment in the configuration of the radial movement suppression means 70c, but other basic configurations are the same as those of the first embodiment. Here, the same components are given the same reference numerals, and duplicated descriptions will be omitted. Note that the mounting hole 75c has the same configuration as the mounting hole 75b, but is given a different reference numeral for convenience.

The radial movement suppression means 70c of the third embodiment includes an abutment member 71c made of a resin-based material with high slipperiness, a biasing member 72c made of a compression coil spring, a holding member 73c that holds the biasing member 72c between the abutment member 71c, an attachment hole 75c that connects the inner and outer peripheral surfaces of the holder part 21 with the same diameter in the direction perpendicular to the axis L, and an axial outer attachment groove 77c formed with a step on the outer peripheral surface of the holder part 21. This abutment member 71c has an expanding cylindrical shape. In this embodiment, the abutment member 71c is preferably made of a resin-based material such as polyphenylene sulfide (PPS) containing fluorine or the like. The abutment member 71c in this embodiment has an expanding cylindrical shape, but is not limited to this and may have any shape that fits the attachment hole 75c having the same diameter.

<Assembly of radial movement suppression means>
11(a) and 11(b), in a state where the abutting member 71c is accommodated in the mounting hole 75c, a holding member 73c having a biasing member 72c sandwiched between the abutting member 71c and the holding member 73c is mounted in the axially outer mounting groove 77c, whereby a biasing force _F3 in a direction perpendicular to the axis L is generated on the guide portion 32 via the abutting member 71c. Similar to the biasing force _F1 in the first embodiment, this biasing force _F3 is set to be greater than the magnetic attraction force of the stepping motor 60. Also, similar to the radial movement suppressing means 70a in the first embodiment, the radial movement suppressing means 70c can constantly maintain a small gap between the male thread portion 31a and the female thread portion 23a in the radial direction.

In this way, in the electric valve 100c of the third embodiment, by adopting the radial movement suppression means 70c instead of the radial movement suppression means 70a, in addition to the same effect as the first embodiment (low operating noise), by preparing the biasing members 72c having various spring constants, the biasing force _F3 can be adjusted without changing the abutment member 71c.

(Fourth embodiment)
A motor-operated valve 100d according to a fourth embodiment will be described with reference to Fig. 12. The motor-operated valve 100d according to the fourth embodiment differs from the motor-operated valve 100a according to the first embodiment in the configuration of the radial movement suppression means 70d, but other basic configurations are the same as those of the first embodiment. Here, the same components are denoted by the same reference numerals, and duplicated explanations will be omitted.

The radial movement suppression means 70d of the fourth embodiment includes an abutment member 71d made of a ring-shaped elastic member (e.g., an O-ring, etc.), a retaining member 73d that holds the abutment member 71d between the guide portion 32, a retaining ring 74d that supports and fixes the retaining member 73d from below, and an axial inner mounting groove 78d that has a step formed on the inner circumferential surface of the holder portion 21.

The retaining member 73d is a ring-shaped bush made of a resin-based material with high slipperiness, and has a sliding portion 73du arranged slidably adjacent to the guide portion 32, and a housing portion 73dd provided below the sliding portion 73du and housing the abutting member 71d slidably, as shown in FIG. 12(a). The housing portion 73dd has an outer peripheral surface 73do formed concentrically with the axis L, and an inner peripheral surface 73di eccentric with respect to the axis L, as shown in FIG. 12(b). In this embodiment, the retaining member 73d is preferably made of a resin-based material such as polyphenylene sulfide (PPS) or polytetrafluoroethylene (PTFE) containing fluorine or the like.

<Assembly of radial movement suppression means>
First, the holding member 73d is fitted and fixed in the axial inner mounting groove 78d of the holder portion 21. Then, the abutting member 71d is accommodated in the accommodation portion 73dd of the holding member 73d, and the drive shaft 30 is inserted from the bottom to the top of the holder portion 21 along the axis L direction while screwing the screw feed mechanism through the bearing hole 24. Then, while supporting the bottom of the holding member 73d and the abutting member 71d with the retaining ring 74d, the retaining ring 74d is fixed to the holder portion 21 by welding or the like. This allows the abutting member 71d to be sandwiched between the guide portion 32 and the inner peripheral surface 73di of the holding member 73d.

Here, the axial inner mounting groove 78d of the holder portion 21 and the outer peripheral surface 73do of the holding member 73d are each formed concentrically with respect to the axis L, while the inner peripheral surface 73di of the holding member 73d is formed to have a center point Od eccentric with respect to the axis L. In addition, the radial annular width of the abutting member 71d in the uncompressed state as viewed from the axis L direction is set to be larger than the maximum radial annular width between the guide portion 32 and the inner peripheral surface 73di of the holding member 73d (see the left side of FIG. 129(b)). Furthermore, since the annular opening diameter of the abutting member 71d as viewed from the axis L direction is set to be smaller than the diameter of the guide portion 32, the inner peripheral surface of the abutting member 71d is held so as to contract toward the guide portion 32 by its own elastic force.

In this way, by sandwiching the abutment member 71d between the guide portion 32 and the inner peripheral surface 73di of the holding member 73d, the abutment member 71c deforms in a direction perpendicular to the axis L and generates a biasing force _F4 perpendicular to the axis L on the guide portion 32. Since the holding member 73d is fitted and fixed in the axially inner mounting groove 78d of the holder portion 21, the inner peripheral surface 73di of the holding member 73d slides against the abutment member 71d. This biasing force _F4 is set to be larger than the magnetic attraction force of the stepping motor 60, similar to the biasing force _F1 in the first embodiment. Also, the radial movement suppressing means 70d can constantly maintain a small gap between the male thread portion 31a and the female thread portion 23a in the radial direction, similar to the radial movement suppressing means 70a in the first embodiment.

In this way, in the electric valve 100d of the fourth embodiment, by adopting the radial movement suppression means 70d instead of the radial movement suppression means 70a, in addition to the same effect as the first embodiment (low operating noise), by preparing a retaining member 73d having a variety of eccentric center points Od, it is possible to adjust the biasing force _F4 without changing the abutment member 71d.

In addition, in the motor-operated valves 100a to 100c according to the first to third embodiments, the abutment members 71a, 71b, and 71c are provided in the mounting holes 75a, 75b, and 75c that penetrate in a direction perpendicular to the axis L, so there is a risk that the movement of the abutment members 71a, 71b, and 71c in the direction in which they are biased may be affected by fluid movement through the mounting holes 75a, 75b, and 75c. In contrast, in the motor-operated valve 100d according to the fourth embodiment, the entire configuration of the radial movement suppression means 70d is disposed inside the holder portion 21, thereby suppressing the influence of fluid movement in the direction in which the abutment member 71d is biased, and allowing the motor-operated valve 100d to function more reliably.

Fifth Embodiment
A motor-operated valve 100e according to a fifth embodiment will be described with reference to Fig. 13. The motor-operated valve 100e according to the fifth embodiment differs from the motor-operated valve 100d according to the fourth embodiment in that the retaining member 73d, the retaining ring 74d, and the axially inner mounting groove 78d are omitted, but the other basic configurations are the same as those of the fourth embodiment. Here, the same components are denoted by the same reference numerals, and duplicated explanations will be omitted.

The radial movement suppression means 70e of the fifth embodiment includes an abutment member 71e made of a ring-shaped elastic member (e.g., an O-ring) and a circumferential groove 79e of the guide portion 32 formed eccentrically with respect to the axis L.

<Assembly of radial movement suppression means>
First, the abutment member 71e is accommodated in the circumferential groove 79e of the guide portion 32, and the drive shaft 30 is inserted from below to above the holder portion 21 along the axis L direction while screwing into the screw feed mechanism through the bearing hole 24. This allows the abutment member 71e to be sandwiched between the guide portion 32 and the bearing hole 24.

Here, the bearing hole 24 is formed concentrically with respect to the axis L, while the circumferential groove 79e of the guide part 32 is formed to have a center point Oe that is eccentric with respect to the axis L. In addition, the radial annular width of the abutting member 71e in a non-compressed state as viewed from the axis L direction is set to be larger than the maximum radial annular width of the circumferential groove 79e of the guide part 32 (see the left side of FIG. 13(b)). Furthermore, since the annular opening diameter of the abutting member 71e as viewed from the axis L direction is set to be smaller than the diameter of the non-circumferential groove part of the guide part 32, the inner peripheral surface of the abutting member 71e is held to contract toward the guide part 32 by its own elastic force.

In this manner, by sandwiching the abutment member 71e between the guide portion 32 and the bearing hole 24, the abutment member 71e deforms in a direction perpendicular to the axis L and generates a biasing force _F5 in the guide portion 32 in a direction perpendicular to the axis L. Since the abutment member 71e is held in the circumferential groove 79e of the guide portion 32 by its own elastic force, the outer peripheral surface of the abutment member 71e slides relative to the bearing hole 24. This biasing force _F5 is set to be larger than the magnetic attraction force of the stepping motor 60, similar to the biasing force _F1 in the first embodiment. Also, the radial movement suppressing means 70e can constantly maintain a small gap between the male thread portion 31a and the female thread portion 23a in the radial direction, similar to the radial movement suppressing means 70a in the first embodiment. In addition, since the radial movement suppression means 70e in this embodiment is provided between the bearing hole 24 and the guide portion 32, the abutment member 71e and the female thread portion 23a do not overlap, and do not affect the movement of the drive shaft 30 in the axial L direction.

In this way, the motor-operated valve 100e according to the fifth embodiment employs radial movement suppression means 70e instead of radial movement suppression means 70d, thereby achieving the same effects as the fourth embodiment (low operating noise, suppression of the effects of fluid movement).

In the motor-operated valves 100a to 100d according to the first to fourth embodiments, the directions of the biasing forces _F1 to _F4 by the radial movement suppression means 70a to 70d, as viewed from the axis L direction, were fixed in one direction regardless of the rotation of the drive shaft 30, so there was a risk of one-sided wear occurring to some extent in the screw feed mechanism. In contrast, in the motor-operated valve 100e according to the fifth embodiment, the inner peripheral surface of the abutting member 71e is held by the guide portion 32 by its own elastic force, while the outer peripheral surface of the abutting member 71e slides against the bearing hole 24. As a result, the direction of the biasing force _F5 , as viewed from the axis L direction, rotates together with the drive shaft 30, so that one-sided wear in the screw feed mechanism can be suppressed.

In this embodiment, the male threaded portion 31a is provided on the drive shaft 30 connected to the magnet rotor 62, and the female threaded portion 23a is fixed to the valve body 10, and a radial movement suppression means is adopted for the motor-operated valves 100a to 100d in which the male threaded portion 31a is movable in the axial direction relative to the female threaded portion 23a. However, this is not limited to the above, and for example, a female threaded portion may be provided on the inner peripheral surface of the magnet rotor, and the male threaded portion may be fixed to the valve body, and a radial movement suppression means may be adopted for a motor-operated valve in which the female threaded portion is movable in the axial direction relative to the male threaded portion, and the drive shaft connected to the magnet rotor may be biased in a direction perpendicular to the axis L.

<About the refrigeration cycle system>
The refrigeration cycle system of the present invention will be described with reference to Fig. 14. The refrigeration cycle system includes an expansion valve 100 using the motor-operated valves 100a to 100e of the first to fifth embodiments, an outdoor heat exchanger 200 mounted on an outdoor unit, an indoor heat exchanger 300 mounted on an indoor unit, a flow path switching valve 400 constituting a four-way valve, and a compressor 500. Here, the expansion valve 100, the outdoor heat exchanger 200, the indoor heat exchanger 300, the flow path switching valve 400, and the compressor 500 are each connected by a conduit to constitute a heat pump type refrigeration cycle. Note that an accumulator, a pressure sensor, a temperature sensor, etc. are not shown in the figure.

The flow path of the refrigeration cycle is switched between two paths, one for cooling operation and one for heating operation, by the flow path switching valve 400. During cooling operation (see the solid arrow in the figure), the refrigerant compressed by the compressor 500 flows from the flow path switching valve 400 into the outdoor heat exchanger 200, which functions as a condenser, and the liquid refrigerant flowing out of the outdoor heat exchanger 200 flows into the indoor heat exchanger 300 via the expansion valve 100, which functions as an evaporator.

On the other hand, during heating operation (see the dashed arrow in the figure), the refrigerant compressed by the compressor 500 is circulated from the flow path switching valve 400 to the indoor heat exchanger 300, the expansion valve 100, the outdoor heat exchanger 200, the flow path switching valve 400, and then to the compressor 500, with the indoor heat exchanger 300 functioning as a condenser and the outdoor heat exchanger 200 functioning as an evaporator. Therefore, the expansion valve 100 decompresses and expands the liquid refrigerant flowing in from the outdoor heat exchanger 200 during cooling operation, or the liquid refrigerant flowing in from the indoor heat exchanger 300 during heating operation, and can further control the flow rate of the refrigerant.

The present invention is not limited to the first to fifth embodiments, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention. For example, the first to fifth embodiments illustrate motor-operated valves 100a to 100e used in air conditioners such as home air conditioners, but the motor-operated valves of the present invention are not limited to home air conditioners, and may be used in commercial air conditioners, and are not limited to air conditioners, but can also be applied to various types of refrigeration machines, etc.

＜Other＞
It goes without saying that the motor-operated valves 100a to 100e of the present embodiment are applicable not only to the refrigeration cycle illustrated, but also to any other fluid device and fluid circuit. Furthermore, the present invention is not limited to the above-described aspects, embodiments, and modified examples, and may be modified or altered as appropriate without departing from the technical concept of the present invention.

100a to 100e, 100a″ Motor-operated valve 10 Valve body 20, 20″ Support member 21 Holder portion 21a Radial groove (rotation stopper portion)
21a″ radial groove 21b, 21b″ protrusion (rotation stopper portion)
21c Pin hole 21d Stopper pin (rotation stopper)
21e Axial groove (rotation stopper)
21f: retaining claw portion 22: fixing portion 23: screw hole 23a: female screw portion (screw feed mechanism portion)
24 Bearing hole (bearing part)
25 Slide hole 30 Drive shaft 31 Threaded portion 31a Male threaded portion (screw feed mechanism)
32 Guide portion 40 Valve body portion 50 Coil member 60 Stepping motors 70a to 70e, 70a1 to 70a9 Radial movement suppressing means 71a to 71e, 71a1 to 71a3, 71a1-1 to 71a1-4, 71a', 71a'' Abutment members 71a1c-1 to 71a1c-4 Contact portion 71a1p Protrusion portion (rotation stopper portion)
71a2d Recessed portion (rotation stopper portion)
71a3s Straight section (rotation stopper section)
71a'1, 71a''1 Contact portion 71a'2, 71a''2 Pressing portion 71a''21 Circumferential mounting groove 72a to 72c, 72a1 to 72a7, 72a9 Pressing member 72a1n Pair of notched ends (rotation stopper engagement portion) (pair of ends)
72a2f A pair of radial folded end portions (rotation stopper engagement portions) (a pair of end portions)
72a3b A pair of straight bent ends (rotation stopper engagement portion) (a pair of ends)
72a4n: A pair of notched ends (rotation stopper engagement portion) (a pair of ends)
72a5n A pair of notched ends (rotation stopper engagement portion) (a pair of ends)
72a6f A pair of radial folded end portions (rotation stopper engagement portions) (a pair of end portions)
72a7b A pair of axially bent ends (rotation stopper engagement portion) (pair of ends)
72a9n Pair of notched ends (rotation stopper engagement portion) (pair of ends)
73c Holding member 75a to 75c, 75a″ Mounting hole 76a, 76a4, 76a″, 76b Circumferential mounting groove 77c Axial outer mounting groove 78d Axial inner mounting groove 79e Circumferential groove

A _1: Gap between guide portion and bearing hole B: Amount of protrusion of abutting member into mounting groove C ₁ , C _2: Gap between male and female threads Ca-1, Ca-2: Line contact Ca-3, Ca-4: Point contact Da: Diameter of guide portion F ₁ to F ₅ : Urging force L: Axis L71a', L71a'': Axis center Lb of abutting portion Width of contact portion M1, M2: Moment Oa: Central position of urging member θ: Taper angle

Claims (17)

a support member having a drive shaft that moves in an axial direction by a screw feed mechanism that converts rotational motion into linear motion through a male screw portion and a female screw portion that screw together, and a bearing portion that engages with a guide portion of the drive shaft and guides the drive shaft in the axial direction;
a valve body connected to the guide portion of the drive shaft and adapted to adjust an opening degree of the valve port relative to a valve seat;
A radial movement suppressing means for biasing one of the male threaded portion and the female threaded portion in a direction perpendicular to the axis to suppress relative radial movement of the male threaded portion and the female threaded portion;
A motor-operated valve comprising: The motor-operated valve according to claim 1 , wherein the radial movement suppressing means biases the guide portion in a direction perpendicular to the axis . The motor-operated valve according to claim 2, characterized in that the radial movement suppression means has an abutment member that contacts the drive shaft, and biases one of the male threaded portion and the female threaded portion in a direction perpendicular to the axis via the abutment member. The motor-operated valve according to claim 3, characterized in that the contact state between the drive shaft of the radial movement suppression means and the abutment member is at least one line contact extending in the axial direction of the drive shaft. The motor-operated valve according to claim 3, characterized in that the contact state between the drive shaft of the radial movement suppression means and the abutment member is at least one point contact. The abutment member is disposed opposite to an outer circumferential surface of the drive shaft,
4. The motor-operated valve according to claim 3, wherein the radial movement suppressing means further includes a biasing member that applies a biasing force to the contact member. The motor-operated valve according to claim 6, characterized in that the abutment member is substantially L-shaped when viewed from a direction perpendicular to the axis , and has an abutment portion that abuts against the drive shaft, and a biasing portion that extends along the outer circumferential surface of the support member so as to be spaced apart from the axis of the abutment portion and abuts against the biasing member. The motor-operated valve according to claim 7, characterized in that the biasing portion extends along the axial direction of the outer peripheral surface of the support member. The motor-operated valve according to claim 6, characterized in that the urging member has a cutout portion and is C-shaped when viewed from the axial direction , and a pair of ends of the urging member are provided with anti-rotation engagement portions that are directly or indirectly held by the support member. The motor-operated valve according to claim 9, characterized in that a rotation stopper is provided on the radially outer side of the contact member, and the rotation stopper engagement portion of the biasing member is engaged with the rotation stopper, thereby holding the biasing member to the support member via the contact member. The motor-operated valve according to claim 9, characterized in that a circumferential mounting groove is formed on the outer peripheral surface of the support member, a rotation stopper is provided on the support member so that the circumferential mounting groove is discontinuous in the circumferential direction, the rotation stopper engagement portion of the biasing member engages with the rotation stopper, and the biasing member is held by the support member. The motor-operated valve according to claim 9, characterized in that a continuous circumferential mounting groove is formed on the outer circumferential surface of the support member, a rotation stopper is provided that is continuously connected to the circumferential mounting groove on the radially inward side or in the axial direction, the rotation stopper engagement portion of the biasing member engages with the rotation stopper, and the biasing member is held by the support member. The motor-operated valve according to claim 6, characterized in that the radial movement suppression means further includes a holding member that holds the biasing member between the contact member and the holding member. The motor-operated valve according to claim 3, characterized in that the abutment member is made of a ring-shaped elastic member, and further includes a holding member that holds the abutment member between the drive shaft and the drive shaft when the abutment member is deformed in a direction perpendicular to the axis. The motor-operated valve according to claim 3, characterized in that the abutment member is made of a ring-shaped elastic member and is disposed in a circumferential groove of the drive shaft in a state in which it is deformed in a direction perpendicular to the axis. The valve body is connected to the drive shaft so as to be displaceable relative to the drive shaft in a radial direction.
2. The motor-operated valve according to claim 1, wherein the radial movement suppressing means biases the drive shaft. A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, characterized in that the motor-operated valve according to any one of claims 1 to 16 is used as the expansion valve.

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