JP7585183B2 - Motor-operated valve and refrigeration cycle system - Google Patents

Description

The present invention relates to an electrically operated valve for use in a refrigeration cycle system and a refrigeration cycle system.

A known motor-operated valve includes a valve body having a valve chamber and a valve port, a valve element that changes the opening of the valve port, a drive unit that drives the valve element back and forth in the axial direction, and a support member that constitutes a screw feed mechanism together with the drive shaft of the drive unit (see, for example, Patent Document 1). In the motor-operated valve of Patent Document 1, the rotational motion of the drive shaft of the drive unit is converted into linear motion in the axial direction of the drive shaft by the screw feed mechanism, and the opening of the valve port is controlled by the valve member of the valve element connected to the drive shaft.

Here, such a motor-operated valve will be specifically described with reference to Figure 4, which is an assembled cross-sectional view showing a conventional motor-operated valve in a fully closed state. That is, for example, as shown in Figure 4, the valve body 1 has a cylindrical valve housing member 1A, a valve guide member 1B fixed inside the valve housing member 1A, a cylindrical case 4 fixed to the upper part of the valve housing 1A, and a support member 5 fixed to the upper end opening of the case 4. Note that the concept of "upper and lower" in this description corresponds to the upper and lower in Figure 4.

The valve housing member 1A has a substantially cylindrical valve chamber 1C formed therein, and a first coupling tube 11 is attached to the side of the valve housing member 1A, which communicates with the valve chamber 1C. The valve housing member 1A also has a valve port 14, which is a cylindrical valve opening, formed in the center of the valve seat portion 13. The upper end of the valve housing member 1A also has a rim 1b formed to surround the valve guide member 1B. The bottom side of the valve housing member 1A also has a cylindrical portion 15 having a part of the valve port 14 formed therein. The second coupling tube 12, which communicates with the valve chamber 1C, is disposed on the outer periphery of the cylindrical portion 15 and is attached by brazing to the bottom of the valve housing member 1A. When a refrigerant as a fluid flows in from the first coupling tube 11, the refrigerant flows out of the second coupling tube 12 through the valve chamber 1C. When refrigerant flows in from the second joint pipe 12, the refrigerant that passes through the valve chamber 1C via the valve port 14 flows out from the first joint pipe 11. The cylindrical portion 15 has a cylindrical inner circumferential surface that is continuous with the valve port 14 of the valve housing member 1A, and is molded integrally with the valve housing member 1A.

The valve guide member 1B, which serves as the valve guide, is pressed into the top of the valve housing member 1A and attached while inserted into the valve chamber 1C. This valve guide member 1B has a valve guide hole 16 formed around the axis L. The case 4 is assembled so that it fits onto the outer periphery of the rim 1b of the valve housing member 1A, and is fixed to the valve housing member 1A by crimping the rim 1b and brazing the outer periphery of the bottom.

The support member 5 is welded to the upper opening of the case 4 via a fixing bracket 41. A female threaded portion 5a is provided at the center of the upper side of the support member 5, and is formed coaxially with the axis L of the valve port 14, etc., and a cylindrical guide hole 5c with a diameter larger than the outer periphery of the female threaded portion 5a is formed on the lower side.

The valve body 2 as a valve member has a rod shaft 22 as a shaft part with a needle part 21 at the lower end, and a valve body holder 6 that holds the upper end part of the rod shaft 22. A flange part 23 is formed at the upper end part of the rod shaft 22. The needle part 21 provided on the rod shaft 22 is located in the valve port 14 when the valve body 2 is in the fully closed state when it is moved to the bottommost position, and has a shape with an equal percentage characteristic that is chamfered in multiple stages so that the diameter decreases toward the tip side. In this case, the needle part 21 is connected to a seating surface part 21a that seats on the valve seat part 13 when the valve body 2 is in the fully closed state when it is moved to the bottommost position. The valve body 2 may be set so that a small opening degree is obtained by not making the needle part 21 contact the valve seat part 13 even when it is in the fully closed state when it is moved to the bottommost position (i.e., when it is in the state closest to the valve seat part 13).

The valve body holder 6 has a flange portion 23 of the rod shaft 22 fixed to the lower end of a cylindrical portion 61, and includes a spring bearing 63, a compression coil spring 64, and a washer 65 inside the cylindrical portion 61. That is, the valve body holder 6 is provided at one end on the valve port 14 side with the valve body 2 fixed by press-fitting and welding, and accommodates a compression coil spring 64 that biases the valve body 2 and the spring bearing 63 in a direction separating them. In addition, a rotor shaft 32 described later is connected to the other end of the valve body holder 6 as a drive shaft. At least one of the valve body 2 or the rotor shaft 32 is connected to the inside of the valve body holder 6 so as to be movable forward and backward in a state in which it is prevented from coming off the valve body holder 6. Furthermore, the valve body holder 6 is inserted into the guide hole 5c of the support member 5 and supported so as to be slidable in the axial direction L. In other words, the lower side of the guide hole 5c in the support member 5 functions as a holder guide portion 5d that guides the valve body holder 6.

The stepping motor 3 as a drive unit has a can 7, a magnet rotor 31 provided in the can 7, a rotor shaft 32, a stator coil (not shown), and a rotation stopper mechanism 8 for the stepping motor 3.

The can 7 is fixed airtight to the upper end of the case 4 by welding or the like, and houses the support member 5 and the magnet rotor 31. The outer periphery of the magnet rotor 31 is magnetized with multiple poles, and the rotor shaft 32 is fixed to its center. The lower end of the rotor shaft 32 penetrates the upper end of the cylindrical part 61 of the valve body holder 6 and abuts against the upper surface of the spring receiver 63, and the flange part 32c for preventing it from coming off is held in the cylindrical part 61 via a washer 65. In addition, the rotor shaft 32 has a male screw part 32a formed on the upper surface of its middle part. This male screw part 32a is screwed into the female screw part 5a of the support member 5, and these male screw part 32a and female screw part 5a constitute the screw feed mechanism 17 of the drive part. The screw feed mechanism 17 converts the rotational motion of the stepping motor 3 into linear motion of the rotor shaft 32, so that the valve body 2 is driven forward and backward in the axis L direction. The stator coil is arranged around the outer periphery of the can 7, and when a pulse signal is given to this stator coil, the magnet rotor 31 rotates according to the number of pulses, causing the rotor shaft 32 to rotate.

The rotation stopper mechanism 8 of the stepping motor 3 has a guide support 8A fixed to the ceiling of the can 7, and the guide support 8A has a cylindrical guide 86 that hangs down from the center of the ceiling of the can 7 along the axis, a screw guide 87 fixed to the outer periphery of the guide 86, and a movable slider 88 that can rotate and move up and down guided by the screw guide 87. The movable slider 88 has a claw portion 88a that protrudes radially outward, and the magnet rotor 31 has an extension portion 31a that extends upward and abuts against the claw portion 88a. When the magnet rotor 31 rotates, the extension portion 31a presses the claw portion 88a, causing the movable slider 88 to rotate and move up and down following the screw guide 87. In addition, a tube member 8B that guides the upper part of the rotor shaft 32 is fitted inside the cylindrical guide 86.

The spiral guide 87 is formed with an upper end stopper 87a that determines the uppermost position of the magnet rotor 31, and a lower end stopper 87b that determines the lowermost position of the magnet rotor 31. When the movable slider 88, which has descended in association with the forward rotation of the magnet rotor 31, abuts against the lower end stopper 87b, the movable slider 88 becomes unable to rotate at this abutting position, thereby restricting the rotation of the magnet rotor 31 and stopping the descent of the valve body 2. On the other hand, when the movable slider 88, which has ascended in association with the reverse rotation of the magnet rotor 31, abuts against the upper end stopper 87a, the movable slider 88 becomes unable to rotate at this abutting position, thereby restricting the rotation of the magnet rotor 31 and stopping the ascent of the valve body 2.

JP 2021-124153 A

Incidentally, motorized valves for refrigeration and air conditioning are sometimes required to control the amount of fluid flowing inside the valve, as well as to dam the flow. However, when the valve disc is moved up and down, the differential pressure and dynamic pressure inside the valve chamber caused by the fluid passing through the inside of the valve can cause the valve disc to sit tilted, making it important to seat the valve disc accurately on the valve seat. One way to improve this is to extend the valve guide hole in the valve guide member to guide the valve disc right up to the valve seat, but if the concentricity of the holder guide, valve disc guide, and valve seat is low, the valve disc may be restricted (locked). Therefore, it was necessary to improve the assembly precision.

In particular, when the valve disc is integrally provided with the valve disc holder, the valve disc and the valve disc holder cannot move relative to each other in the radial direction, so the effect of the concentricity of the holder guide, valve disc guide, and valve seat is particularly pronounced. This means that the clearance between the valve disc guide section and the valve disc must be increased, resulting in a problem of valve leakage.

The object of the present invention is to provide an electric valve and a refrigeration cycle system that can suppress valve leakage while ensuring the operability of the valve member.

The motor-operated valve of the present invention comprises a valve body having a valve chamber and a valve port, a valve member for changing the opening degree of the valve port, a drive section having a drive shaft for driving the valve member back and forth in the axial direction of the valve port, a support member which constitutes a screw feed mechanism together with the drive shaft, a valve holder spanning the valve member and the drive shaft, and a holder guide for guiding the valve holder in the axial direction, and the motor-operated valve converts rotational motion of the drive section into linear motion in the axial direction of the drive shaft by the screw feed mechanism, and controls the opening degree of the valve port by the valve member connected to the drive shaft, and the support member is fixed to the valve body, and the valve member and the drive shaft are aligned in the same direction. the valve member is suspended from a fitting hole provided at the end of the valve holder on the valve port side and slidably inserted into the valve holder and guided in the axial direction by a cylindrical valve guide portion fixed to the valve body, and when a clearance between the valve member and the valve guide portion is A, a clearance between the valve holder and the holder guide is B, and a clearance between the valve member and the fitting hole of the valve holder is C, the relationship between these clearances A to C is set to A<B and A<C , and the relationship between the clearance B and the clearance C is set to B<C .

According to the present invention, the valve member can be driven while suppressing the effects of dimensional variation in the drive section (the male threaded section of the drive shaft and the female threaded section of the support member, and the joint between the drive shaft and the valve holder) and backlash during operation. In other words, even if the drive section (the male threaded section of the drive shaft and the female threaded section of the support member, and the joint between the drive shaft and the valve holder) is misaligned, the amount of movement of the valve member is regulated by the clearance between the valve member and the valve guide section, so concentricity with the valve seat section can be ensured. Thus, valve leakage can be suppressed while ensuring the operability of the valve member.

In this case, since the relationship between the clearance B and the clearance C is set to B<C, the radial movement of the valve holder is restricted before the valve member comes into contact with the fitting hole, so that the valve member is not affected by radial positional deviation of the valve holder. In other words, the fitting hole and the valve member do not come into contact with each other, and no sliding resistance occurs.

Furthermore, it is preferable that the valve member has a shaft portion that is guided by the valve guide portion, and the amount of axial guidance of the valve member by the valve guide portion is set to be longer than the diameter of the shaft portion of the valve member. This allows the valve member to be guided by a sufficient length, thereby reducing valve leakage.

The refrigeration cycle system of the present invention is a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, and is characterized in that any one of the motor-operated valves is used as the expansion valve.

As described above, according to the present invention, the motor-operated valve of the present invention drives the valve member while suppressing the effects of backlash during operation, thereby ensuring the operability of the valve member while suppressing valve leakage, resulting in a refrigeration cycle system that is energy-efficient and less prone to malfunctions during operation.

The motor-operated valve and refrigeration cycle system of the present invention can suppress valve leakage while ensuring the operability of the valve member.

1 is a vertical cross-sectional view showing a motor-operated valve according to an embodiment of the present invention. 2 is an enlarged longitudinal sectional view showing a main part of the motor-operated valve of FIG. 1. FIG. 1 is a diagram showing an example of a refrigeration cycle system of the present invention. FIG. 1 is a vertical cross-sectional view showing a conventional motor-operated valve.

The motor-operated valve according to an embodiment of the present invention will be described in detail with reference to Figs. 1 and 2. As shown in Fig. 1, the motor-operated valve 10 of this embodiment includes a valve body 1, a valve element 2 as a valve member, a stepping motor 3 as a drive unit, and a valve port 14. Note that the concepts of "upper and lower" in the following description correspond to the upper and lower in Fig. 1.

The valve body 1 has a cylindrical valve housing member 1A, a valve guide member 1B as a valve guide portion fixed inside the valve housing member 1A, a cylindrical case 4 fixed to the top of the valve housing 1A, and a support member 5 fixed to the upper end opening of the case 4.

The valve housing member 1A has a substantially cylindrical valve chamber 1C formed therein, and a first coupling tube 11 is attached to the side of the valve housing member 1A, which communicates with the valve chamber 1C. The valve housing member 1A also has a valve port 14, which is a cylindrical valve opening, formed in the center of the valve seat portion 13. The upper end of the valve housing member 1A also has a rim 1b formed to surround the valve guide member 1B. The bottom side of the valve housing member 1A also has a cylindrical portion 15 having a part of the valve port 14 formed therein. The second coupling tube 12, which communicates with the valve chamber 1C, is disposed coaxially with the valve port 14 on the outer periphery of the cylindrical portion 15 and is attached by brazing to the bottom of the valve housing member 1A. When a refrigerant as a fluid flows in from the first coupling tube 11, the refrigerant flows out of the second coupling tube 12 through the valve chamber 1C. When refrigerant flows in from the second joint pipe 12, the refrigerant that passes through the valve chamber 1C via the valve port 14 flows out from the first joint pipe 11. The cylindrical portion 15 has a cylindrical inner circumferential surface that is continuous with the valve port 14 of the valve housing member 1A, and is molded integrally with the valve housing member 1A.

The valve guide member 1B is press-fitted into the top of the valve housing member 1A and is attached while inserted into the valve chamber 1C. The valve guide member 1B has a valve guide hole 16 formed around the axis L. The case 4 is assembled so that it fits onto the outer periphery of the rim 1b of the valve housing member 1A, and is fixed to the valve housing member 1A by crimping the rim 1b and brazing the bottom periphery.

The support member 5 is welded to the upper opening of the case 4 via a fixing bracket 41. A female threaded portion 5a is provided at the center of the upper side of the support member 5, which is formed coaxially with the axis L of the valve port 14, etc., and a cylindrical guide hole 5c with a diameter larger than the outer periphery of the female threaded portion 5a is formed on the lower side. In this embodiment, the support member 5 is fitted in a state where it is welded to the upper opening of the case 4 via the fixing bracket 41, but the support member 5 may also be press-fitted into the case 4.

The valve body 2 has a rod shaft 22 as an axis part with a needle part 21 at the lower tip, and a valve body holder 6 that holds the upper end part of the rod shaft 22. The rod shaft 22 is inserted into the valve guide hole 16 of the valve guide member 1B so as to be slidable in the axial direction L. A flange part 23 is formed at the upper end part of the rod shaft 22. The needle part 21 provided on the rod shaft 22 is connected to the seating surface part 21a of the needle part 21 that sits on the valve seat part 13 when the valve body 2 is in the fully closed state in which the valve body 2 is moved to the bottom, and has a shape having an equal percentage characteristic in which the needle part 21 is chamfered in multiple stages so as to reduce in diameter toward the tip side. The valve body 2 may be set so that a small opening degree is obtained by not making the needle part 21 contact the valve seat part 13 even when the valve body 2 is in the fully closed state in which it is moved to the bottom (i.e., when it is in the state closest to the valve seat part 13). Furthermore, the needle portion 21 is not limited to an equal percentage characteristic, and may have a chamfered shape that provides a normal linear characteristic or a linear characteristic that changes in multiple stages.

The valve body holder 6 has a boss portion 62 fixed to the lower end of a cylindrical portion 61, and includes a spring bearing 63, a compression coil spring 64, a washer 65, and a spacer portion 67 in the cylindrical portion 61. The upper end of the rod shaft 22 is inserted into the fitting hole 62a of the boss portion 62, and the flange portion 23 of the rod shaft 22 is abutted against the boss portion 62 to hold the upper end of the rod shaft 22. The valve body holder 6 is inserted into the guide hole 5c of the support member 5 and supported so as to be slidable in the axial direction L. In other words, the valve body holder 6 is provided at one end on the valve port 14 side with the valve body 2 suspended, and contains a compression coil spring 64 that biases the valve body 2 and the spring bearing 63 in a direction separating them. The other end of the valve body holder 6 is connected to the rotor shaft 32, which will be described later, as a drive shaft. At least one of the valve body 2 and the rotor shaft 32 is connected to the valve body holder 6 so that it can move forward and backward while being prevented from coming off the valve body holder 6.

In this embodiment, the thickness of the flange portion 32c of the rotor shaft 32 is thinner than the height of the recessed portion 67a in which the flange portion 32c is accommodated, which is formed in the spacer portion 67 arranged between the washer 65 and the spring bearing 63 in the valve body holder 6. In other words, a gap is provided in the flange portion 32c when it is accommodated in the recessed portion 67a of the spacer portion 67. Therefore, when the valve is open, the biasing force of the compression coil spring 64 is not transmitted to the rotor shaft 32, and the valve body holder 6 is in a state of hanging from the rotor shaft 32. The biasing force of the compression coil spring 64 acts on the rotor shaft 32 through the spring bearing 63 only when the valve is closed. This makes the valve body holder 6 less susceptible to the effect of backlash between the rotor shaft 32 and the support member 5. In addition, since the valve body 2 is guided by the valve guide member 1B, the valve body 2 is easily seated on the valve seat 13 without tilting. That is, after the valve body 2 is seated on the valve seat 13, the rotor shaft 32 moves by the gap between the recessed portion 67a of the spacer portion 67 and the flange portion 32c, and the aforementioned biasing force begins to act. This reduces valve leakage. The spacer portion 67 and the spring retainer 63 may be formed integrally. This reduces the number of parts. The valve body holder 6 and the rotor shaft 32 may also be fixed integrally by crimping or the like.

Furthermore, the valve body holder 6 is inserted into the guide hole 5c of the support member 5 and guided in the direction of the axis L. In other words, the lower side of the guide hole 5c of the support member 5 functions as a holder guide portion 5d that guides the valve body holder 6. The holder guide portion 5d may be provided integrally with the support member 5 or may be provided separately from the support member 5.

The stepping motor 3 as a drive unit has a can 7, a magnet rotor 31 provided in the can 7, a rotor shaft 32 as a drive shaft, a stator coil (not shown), and a rotation stopper mechanism 8 for the stepping motor 3.

The can 7 is fixed airtight to the upper end of the case 4 by welding or the like, and houses the support member 5 and the magnet rotor 31. The outer periphery of the magnet rotor 31 is magnetized with multiple poles, and the rotor shaft 32 is fixed to its center. The lower end of the rotor shaft 32 penetrates the upper end of the cylindrical part 61 of the valve body holder 6 and abuts against the upper surface of the spring receiver 63, and the flange part 32c for preventing it from coming off is held in the cylindrical part 61 via a washer 65. In addition, the rotor shaft 32 has a male screw part 32a formed on the upper surface of its middle part. This male screw part 32a is screwed into the female screw part 5a of the support member 5, and these male screw part 32a and female screw part 5a constitute the screw feed mechanism 17 of the drive part. The screw feed mechanism 17 converts the rotational motion of the stepping motor 3 into linear motion of the rotor shaft 32, so that the valve body 2 is driven forward and backward in the axis L direction. The stator coil is arranged around the outer periphery of the can 7, and when a pulse signal is given to this stator coil, the magnet rotor 31 rotates according to the number of pulses, causing the rotor shaft 32 to rotate.

The rotation stopper mechanism 8 of the stepping motor 3 has a guide support 8A fixed to the ceiling of the can 7, and the guide support 8A has a cylindrical guide 86 that hangs down from the center of the ceiling of the can 7 along the axis, a screw guide 87 fixed to the outer periphery of the guide 86, and a movable slider 88 that can rotate and move up and down guided by the screw guide 87. The movable slider 88 has a claw portion 88a that protrudes radially outward, and the magnet rotor 31 has an extension portion 31a that extends upward and abuts against the claw portion 88a. When the magnet rotor 31 rotates, the extension portion 31a presses the claw portion 88a, causing the movable slider 88 to rotate and move up and down following the screw guide 87. In addition, a tube member 8B that guides the upper part of the rotor shaft 32 is fitted inside the cylindrical guide 86.

The spiral guide 87 is formed with an upper end stopper 87a that determines the uppermost position of the magnet rotor 31, and a lower end stopper 87b that determines the lowermost position of the magnet rotor 31. When the movable slider 88, which has descended in association with the forward rotation of the magnet rotor 31, abuts against the lower end stopper 87b, the movable slider 88 becomes unable to rotate at this abutting position, thereby restricting the rotation of the magnet rotor 31 and stopping the descent of the valve body 2. On the other hand, when the movable slider 88, which has ascended in association with the reverse rotation of the magnet rotor 31, abuts against the upper end stopper 87a, the movable slider 88 becomes unable to rotate at this abutting position, thereby restricting the rotation of the magnet rotor 31 and stopping the ascent of the valve body 2.

The structure of the stepping motor 3 as the driving part in the electric valve 10 is not limited to a shape having an extension portion 31a that abuts against the claw portion 88a of the movable slider 88 described above, but may be a shape in which a coil-shaped driven slider having a claw portion is screwed into a guide groove of a support member, as in the electric valve of Patent Document 1, for example.

In this embodiment, as shown in FIG. 2, the valve body 2 is slidably inserted into the valve body holder 6 while being suspended from a fitting hole 62a provided at the end of the valve body holder 6 on the valve port 14 side, and the rod shaft 22 is arranged so as to be guided in the axis L direction by a cylindrical valve guide member 1B fixed to the valve body 1. In addition, the rotor shaft 32 has an end on the stepping motor 3 side slidably inserted into the valve body holder 6.

If the clearance between the valve body 2 and the valve guide member 1B is A, the clearance between the valve body holder 6 and the holder guide 5d is B, and the clearance between the valve body 2 and the fitting hole 62a of the valve body holder 6 is C, the relationship between these clearances A to C is set to A<B, A<C. Therefore, in the electric valve 10 of this embodiment, the valve body 2 can be driven while suppressing the effects of dimensional variations in the stepping motor 3 (the male threaded portion 32a of the rotor shaft 32 and the female threaded portion 5a of the support member 5, and the joint between the rotor shaft 32 and the valve body holder 6) and backlash during driving.

As described above, according to the motor-operated valve 10 of this embodiment, the valve body 2 is slidably inserted into the valve body holder 6 while being suspended from the fitting hole 62a provided at the end of the valve body holder 6 on the valve port 14 side, and the rod shaft 22 is arranged so as to be guided in the axial direction L by the cylindrical valve guide member 1B fixed to the valve body 1. In addition, the rotor shaft 32 has its end on the valve port 14 side slidably inserted into the valve body holder 6. As a result, even if there is backlash between the rotor shaft 32 and the support member 5, the valve body holder 6 is less susceptible to the lateral vibration of the rotor shaft 32. When the clearance between the valve body 2 and the valve guide member 1B is A, the clearance between the valve body holder 6 and the holder guide 5d is B, and the clearance between the valve body 2 and the fitting hole 62a of the valve body holder 6 is C, the relationship between these clearances A to C is set to A<B, A<C. This allows the valve body 2 to be driven while suppressing the effects of dimensional variation in the stepping motor 3 (the male threaded portion 32a of the rotor shaft 32 and the female threaded portion 5a of the support member 5, and the joint between the rotor shaft 32 and the valve body holder 6) and backlash during driving. In other words, even if the stepping motor 3 (the male threaded portion 32a of the rotor shaft 32 and the female threaded portion 5a of the support member 5, and the joint between the rotor shaft 32 and the valve body holder 6) is biased, the amount of movement of the valve body 2 is restricted by the clearance A between the valve body 2 and the valve guide member 1B, so that concentricity with the valve seat portion 13 can be ensured. Thus, according to the motor-operated valve 10 of this embodiment, valve leakage can be suppressed while ensuring the operability of the valve body 2.

In addition, as in the motor-operated valve 10 of this embodiment, when the first coupling tube 101 is attached to the side of the valve housing member 1A while the second coupling tube 102 is arranged coaxially with the valve port 14, the flow path is bent at approximately 90 degrees between the first coupling tube 101 and the second coupling tube 102. As a result, the flow rate becomes uneven around the axis of the valve body 2, and the valve body 2 may vibrate and generate noise depending on the state of the fluid. In addition, if a fluid enters the clearance A between the valve body 2 and the valve guide member 1B, the valve body 2 may vibrate and generate noise depending on the state of the fluid. However, in the case of the above-mentioned embodiment, the value of the clearance A is sufficiently small, so that the noise caused by the vibration of the valve body 2 can be suppressed.

In this case, it is preferable that the relationship between the clearance B and the clearance C is set to B<C. This restricts the radial movement of the valve body holder 6 before the valve body 2 comes into contact with the fitting hole 62a, so that the valve body 2 is not affected by the radial positional deviation of the valve body holder 6. In other words, the fitting hole 62a and the valve body 2 do not come into contact with each other, and no sliding resistance occurs.

The valve body 2 also has an axis portion that is guided by the valve guide member 1B, and it is preferable that the guide amount L1 of the valve body 2 in the axial direction L by the valve guide member 1B is set to be longer than the diameter L2 of the axis portion of the valve body 2. This allows the valve body 2 to be guided by a sufficient length, thereby reducing valve leakage.

Next, the refrigeration cycle system of the present invention will be described with reference to FIG. 3. FIG. 3 is a diagram showing an example of the refrigeration cycle system of the present invention. In FIG. 3, reference numeral 100 denotes an expansion valve using the motor-operated valve 10 of the above-mentioned embodiment, 200 denotes an outdoor heat exchanger mounted on an outdoor unit, 300 denotes an indoor heat exchanger mounted on an indoor unit, 400 denotes a flow path switching valve constituting a four-way valve, and 500 denotes a compressor. The motor-operated 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 conduits as shown in the figure, constituting a heat pump type refrigeration cycle. Note that the accumulator, pressure sensor, temperature sensor, etc. are omitted from the illustration.

The flow path of the refrigeration cycle is switched by the flow path switching valve 400 to two paths: one for cooling operation and one for heating operation. During cooling operation, as shown by the solid arrows in Figure 3, 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, as shown by the dashed arrows in Figure 3, 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. The expansion valve 100 reduces the pressure 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 further controls the flow rate of the refrigerant. In FIG. 3, the expansion valve 100 is provided in the refrigeration cycle so that liquid refrigerant from the outdoor heat exchanger 200 flows into the first 101 of the expansion valve 100 during cooling operation, and liquid refrigerant from the indoor heat exchanger 300 flows into the second joint pipe 102 of the expansion valve 100 during heating operation. However, the present invention is not limited to this. The expansion valve 100 may be provided in the refrigeration cycle so that liquid refrigerant from the outdoor heat exchanger 200 flows into the second joint pipe 102 of the expansion valve 100 during cooling operation, and liquid refrigerant from the indoor heat exchanger 300 flows into the first joint pipe 101 of the expansion valve 100 during heating operation.

As described above, according to the refrigeration cycle system of the present invention, the motor-operated valve 10 used as the expansion valve 100 drives the valve body 2 while suppressing the effects of backlash during operation, thereby ensuring the operability of the valve body 2 while suppressing valve leakage, resulting in a refrigeration cycle system that is energy-efficient and less prone to malfunctions during operation.

The specific configuration of the refrigeration cycle system of the present invention is not limited to the above-mentioned embodiment, and design changes that do not deviate from the gist of the present invention are also included in the present invention. For example, in the above-mentioned embodiment, the motor-operated valve 10 is used as an expansion valve in the refrigeration cycle system, but the present invention is not limited to this, and can also be applied to other systems, such as a throttling device on the indoor unit side of a multi-air conditioner for a building.

1 Valve body 1A Valve housing member 1B Valve guide member 1C Valve chamber 2 Valve body (valve member)
21 Needle portion 21a Seat surface portion 22 Rod shaft 3 Stepping motor (drive portion)
32 rotor shaft (drive shaft)
32a Male thread portion 5 Support member 5a Female thread portion 5d Holder guide 6 Valve body holder (valve holder)
62a: Mounting hole 10: Motor-operated valve 13: Valve seat portion 131: Seating portion 14: Valve port 17: Screw feed mechanism 100: Expansion valve 200: Outdoor heat exchanger (condenser, evaporator)
300 Indoor heat exchanger (condenser, evaporator)
400 Flow path switching valve 500 Compressor

Claims (3)

an electrically operated valve comprising: a valve body having a valve chamber and a valve port; a valve member for changing an opening degree of the valve port; a drive unit having a drive shaft for driving the valve member back and forth in an axial direction of the valve port; a support member which constitutes a screw feed mechanism together with the drive shaft; a valve holder spanning the valve member and the drive shaft; and a holder guide for guiding the valve holder in the axial direction;
The support member is fixed to the valve body,
the valve member and the drive shaft are concentrically disposed,
the valve member is slidably inserted into the valve holder in a state where the valve member is suspended from a fitting hole provided at an end portion of the valve holder on the valve port side, and is guided in the axial direction by a cylindrical valve guide portion fixed to the valve body,
a clearance between the valve member and the valve guide portion is A, a clearance between the valve holder and the holder guide is B, and a clearance between the valve member and the fitting hole of the valve holder is C, the relationship between these clearances A to C is set to A<B and A<C ,
The motor-operated valve is characterized in that the relationship between the clearance B and the clearance C is set to B<C. the valve member has a shaft portion guided by the valve guide portion,
2. The motor-operated valve according to claim 1 , wherein a guide amount of the valve member in the axial direction by the valve guide portion is set to be longer than a diameter of the stem portion of the valve member. 3. A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, wherein the motor-operated valve according to claim 1 or 2 is used as the expansion valve.

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