JP6956405B2 - Electric valve - Google Patents

Description

The present invention relates to an electric valve used as a flow control valve or the like in a refrigerating cycle of an air conditioner, a refrigerator or the like.

Examples of this type of electric valve include a valve chamber, a valve body having a valve opening formed in the valve chamber, a valve body that opens and closes the valve opening, a can protruding from the valve body, and the outside of the can. A stator coil arranged in the can, a rotor arranged inside the can and rotating by energizing the stator coil, a screw pipe (guide bush) fixed to the valve body, and a rotor rotatably formed together with the rotor. The valve shaft holder that opens and closes the valve opening by the valve body via the valve shaft by the screw feeding action with the screw pipe, and the valve shaft holder and the valve shaft are interposed between the valve shaft holder and the valve shaft. A valve closing spring that urges the valve body in the closing direction of the valve opening via a shaft, and a valve shaft holder in a direction in which the valve body opens and closes the valve opening in cooperation with the valve closing spring. A stopper (fixing member) for preventing relative movement with the rotor is provided, and movement (up and down movement) of the valve shaft in the valve opening opening / closing direction is guided by a screw pipe (guide bush) and a valve shaft holder. Is known (see, for example, Patent Document 1).

In a conventional electric valve of this type, in order to ensure that the valve opening is closed by the valve body, usually, the valve body is seated on a valve seat provided in the valve opening to close the valve opening, and then the rotor and the rotor and the valve opening are further closed. The valve shaft holder is rotated by a predetermined amount (rotation amount) in the valve closing direction and lowered, thereby compressing the valve closing spring interposed between the valve shaft holder and the valve shaft to compress the valve body. It is designed to be pressed against the valve seat.

Specifically, when closing the electric valve, the stator coil is energized in one direction to excite it. As a result, the rotor is rotated, and accordingly, the valve shaft holder is rotated relative to the guide bush (screw pipe). Here, the valve shaft holder is lowered, for example, by the screw feed mechanism of the guide bush (fixed screw portion) and the valve shaft holder (movable screw portion), and the valve shaft is lowered accordingly to raise the valve body. Close the valve opening. At this time, the movable stopper body (upper stopper portion) of the valve shaft holder and the guide bush, which constitute the stopper mechanism for restricting the rotation of the valve shaft holder (and rotor) in the valve closing direction and the downward movement of the valve shaft holder, are fixed. It is positioned away from the stopper body (lower stopper body).

When the stator coil is further energized and excited in one direction from the above state, the valve shaft holder is further lowered by the screw feed mechanism while the valve body remains closed (that is, the valve shaft remains stationary). .. When the valve shaft holder is lowered by a predetermined amount, the movable stopper body of the valve shaft holder and the fixed stopper body of the guide bush come into contact with each other, and the stopper mechanism restricts further lowering of the valve shaft holder. At this time, since the valve closing spring interposed between the valve shaft holder and the valve shaft is compressed, the valve body is strongly pressed against the valve seat, and the valve closing property is ensured (fully closed state). .. Further, at this time, the valve shaft holder is separated from the fixing member (stopper) fixed to the valve shaft by a predetermined gap in the elevating direction.

On the other hand, when opening the electric valve from the fully closed state, the stator coil is energized in the other direction to excite it. As a result, the rotor is rotated relative to the guide bush fixed to the valve body in the direction opposite to the above, and the valve shaft holder is raised by the screw feed mechanism. Here, since the valve shaft holder is positioned so as to be separated from the fixing member fixed to the valve shaft by a predetermined gap, the valve body closes the valve opening during that period (while the valve shaft holder is raised by a predetermined gap). The valve shaft holder rises while it is closed (the valve shaft remains stationary).

From the above state, the stator coil is further energized in the other direction to excite it, and when the valve shaft holder rises by the predetermined gap, the valve shaft holder (upper surface) is fixed to the valve shaft (disk-shaped portion). The valve shaft holder rises with the valve shaft, and the valve body at the lower end of the valve shaft moves upward to open the valve opening.

In this way, the rotor is rotated by energizing the stator coil, the valve shaft holder is rotated integrally with it, and the valve shaft is moved up and down with the valve body, thereby causing the valve body and the valve. The gap (lift amount) between the seat and the seat is increased or decreased to adjust the passing flow rate of a fluid such as a refrigerant.

Japanese Unexamined Patent Publication No. 2011-208716

By the way, in the conventional electric valve as described above, the valve shaft is fitted and inserted in the center of the valve shaft holder so as to be vertically movable, and the movement (vertical movement) of the valve shaft holder and the valve shaft in the valve opening opening / closing direction is guided respectively. It is designed to be guided by the bush. Therefore, when the valve shaft is displaced (tilt with respect to the axis or eccentric in the direction perpendicular to the axis) due to dimensional variation in consideration of operability (sliding), the valve shaft and the valve shaft are displaced. The contact resistance (sliding resistance) with the valve shaft holder becomes large, and there is a risk that the operability may deteriorate. Further, in the conventional electric valve as described above, a valve closing spring is interposed between the portion of the valve shaft that is slidably contacted and guided by the guide bush and the portion that is slidably contacted and guided by the valve shaft holder. There is a concern that the contact resistance (sliding resistance) may increase due to the deformation of the valve closing spring due to the axial deviation of the valve shaft.

Further, in recent years, the pressure in the circuit of the refrigeration cycle tends to increase due to the use of the refrigerant which has been changed in consideration of environmental problems. In order to cope with this pressure increase, it is necessary to make the spring stronger than before to improve the valve closing property of the electric valve. Since it may be pressed, there is a concern that the contact resistance (sliding resistance) will be further increased.

The present invention has been made in view of the above problems, and an object of the present invention is to keep the contact resistance (sliding resistance) low even when the valve shaft is displaced, for example. It is an object of the present invention to provide an electric valve capable of improving operability.

In order to solve the above-mentioned problems, the electric valve according to the present invention basically has a valve shaft provided with a valve body and a guide in which the valve shaft is inserted so as to be relatively movable and relatively rotatable in the axial direction. A valve body having a bush, a valve opening with a valve seat to which the valve body is attached and detached, and the guide bush attached and fixed, a valve shaft holder external to the valve shaft, and a terrace formed on the valve shaft. An urging member interposed between the surface and the valve shaft holder to urge the valve body in the valve closing direction, and the valve shaft holder fixed to the valve shaft so as to be connected to the valve shaft. A fixing member with which the valve shaft holder is brought into contact with the urging force of the urging member, a motor having a rotor and a stator for rotating the valve shaft holder with respect to the guide bush, and a rotational drive of the rotor. The valve is provided with a screw feed mechanism provided between the guide bush and the valve shaft holder for raising and lowering the valve body of the valve shaft with respect to the valve seat of the valve body. A portion of the shaft below the terrace surface is slidably inserted into the guide bush so that the shaft is guided in the axial direction only on the lower side of the urging member. The portion above the terrace surface is inserted into the insertion hole provided in the valve shaft holder with a predetermined gap, and the urging member is externally inserted into the portion above the terrace surface of the valve shaft. It is characterized in that it is interposed between the terrace surface and the valve shaft holder, and the hole diameter of the insertion hole is larger than the inner diameter of the urging member .

Further, in order to solve the above-mentioned problems, the electric valve according to the present invention is basically inserted into a valve shaft provided with a valve body and the valve shaft so as to be relatively movable and relatively rotatable in the axial direction. A valve body having a valve seat with a valve seat to which the valve body is attached and detached, and a valve body to which the guide bush is attached and fixed, a valve shaft holder external to the valve shaft, and a valve shaft formed on the valve shaft. An urging member interposed between the stepped hill surface and the valve shaft holder to urge the valve body in the valve closing direction, and the valve shaft holder fixed to the valve shaft so as to be connected to the valve shaft. A fixed member with which the valve shaft holder is brought into contact with the urging force of the urging member, a motor having a rotor and a stator for rotating the valve shaft holder with respect to the guide bush, and rotation of the rotor. A screw feed mechanism provided between the guide bush and the valve shaft holder for raising and lowering the valve body of the valve shaft with respect to the valve seat of the valve body in response to driving is provided. A portion of the valve shaft below the stepped hill surface is slidably inserted into the guide bush, and the valve shaft is guided in the axial direction only on the lower side of the urging member. The portion above the stepped hill surface is inserted into the insertion hole provided in the valve shaft holder with a predetermined gap, and the portion to which the fixing member is fixed in the valve shaft is inserted in the valve shaft. diameter than the portion which is inserted into the hole and, you are characterized in that there is a smaller diameter than the diameter of the insertion hole.

In a more preferred embodiment, the urging member is interposed between the terrace surface and the valve shaft holder so as to be extrapolated to a portion of the valve shaft above the terrace surface, and is a hole of the insertion hole. The diameter is made larger than the inner diameter of the urging member.

In a more preferred embodiment, the outer diameter of the urging member is made larger than the hole diameter of the insertion hole and the shaft diameter of the portion of the valve shaft below the terrace surface.

According to the present invention, in the valve shaft, a portion below the terrace surface (valve body side) on which the urging member is arranged is slidably inserted into the guide bush, and the lower side (valve body side) of the urging member is slidably inserted. Since it is guided in the axial direction only in the direction of the valve shaft and does not come into contact with the valve shaft holder (the inner wall of the insertion hole), for example, the valve shaft is guided by both the guide bush and the valve shaft holder above and below the urging member. The contact resistance (sliding resistance) can be suppressed lower than that of the valve, and the operability can be improved.

The vertical sectional view which shows the fully closed state of one Embodiment of the electric valve which concerns on this invention. FIG. 3 is a vertical cross-sectional view showing a state in which a valve shaft holder and a fixing member are brought into contact with each other in an embodiment of an electric valve according to the present invention. The valve shaft holder shown in FIG. 1 is shown, (A) is a perspective view, and (B) is a top view.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In each drawing, the gaps formed between the members, the separation distance between the members, etc. may be exaggerated in order to facilitate understanding of the invention and for convenience in drawing. be. Further, in the present specification, the description indicating the position and direction such as up and down, left and right, etc. is based on the direction arrow display of FIGS. 1 and 2, and does not indicate the position and direction in the actual use state.

1 and 2 are vertical cross-sectional views showing an embodiment of the electric valve according to the present invention, FIG. 1 is a fully closed state (a state in which the rotor and the valve shaft holder are in the lowest lowered position), and FIG. , It is a figure which shows the state which the valve shaft holder and the fixing member are brought into contact with each other.

The electric valve 1 of the illustrated embodiment is used by being incorporated as a flow control valve or the like in a refrigerating cycle of an air conditioner, a refrigerator or the like, and is mainly used by a valve shaft 10 provided with a valve body 14 and a guide. A bush 20, a valve shaft holder 30, a valve body 40, a can 55, a stepping motor 50 including a rotor 51 and a stator 52, a compression coil spring (biasing member) 60, and a fixing member 70 as a stopper. , A screw feed mechanism 28 and a lower stopper mechanism 29 are provided.

The valve shaft 10 has an upper small diameter portion 11 and a lower large diameter portion 12 from the upper side, and controls the flow rate of a fluid (refrigerant) flowing through the valve port 46 to the lower end portion of the lower large diameter portion 12. A stepped (here, three steps) inverted conical valve body 14 for this purpose is integrally formed. Further, the upper end portion of the valve shaft 10 (upper small diameter portion 11) has a large diameter, and the fixing portion 71 (small diameter upper portion 71a) of the fixing member 70 described later is fixed to the large diameter connecting portion 15. The outer diameter of the large-diameter connecting portion 15 is larger than that of the upper small-diameter portion 11 and smaller than that of the lower large-diameter portion 12, and the insertion hole 32a of the valve shaft holder 30 (ceiling portion 32) described later is used. The diameter is slightly smaller than the hole diameter (diameter).

The guide bush 20 includes a cylindrical portion 21 inserted in a state in which the valve shaft 10 (lower large diameter portion 12) is relatively movable (sliding) in the axis O direction and relatively rotatable around the axis O. It extends upward from the upper end of the cylindrical portion 21, has an inner diameter larger than that of the cylindrical portion 21, and is inserted into the upper end side of the lower large diameter portion 12 of the valve shaft 10 and the lower end side of the upper small diameter portion 11. It has a setting part 22 and. On the outer circumference of the cylindrical portion 21 of the guide bush 20, one of the screw feed mechanisms 28 that raises and lowers the valve body 14 of the valve shaft 10 with respect to the valve seat 46a of the valve body 40 according to the rotational drive of the rotor 51 is configured. A fixing screw portion (male screw portion) 23 is formed. Further, the lower portion of the cylindrical portion 21 (the portion below the fixing screw portion 23) has a large diameter, and is a fitting portion 27 into the fitting hole 44 of the valve body 40. A lower stopper 25 is screwed and fixed to the fixing screw portion 23 (below the valve shaft holder 30 in the fixing screw portion 23), and the rotation downward movement of the valve shaft holder 30 is regulated on the outer circumference of the lower stopper 25. A fixed stopper body 24 constituting one of the lower stopper mechanisms 29 to be performed is integrally projected.

The valve shaft holder 30 is made of, for example, a resin (preferably made of a resin reinforced with SUS, carbon fiber, or the like having high wear resistance in consideration of contact with the fixing member 70), and the guide bush 20 is An insertion hole 32a through which the cylindrical portion 31 to be inserted and the upper end portion of the valve shaft 10 (upper small diameter portion 11) are inserted (in a state where they can move relative to the axis O and rotate relative to the axis O) penetrate. It has a ceiling portion 32 provided. In this example, the hole diameter of the insertion hole 32a is larger than the upper end of the valve shaft 10 (upper small diameter portion 11), and the valve shaft 10 (upper small diameter portion 11) is predetermined to the insertion hole 32a. It is inserted (floating) with a gap. A movable screw portion (female screw portion) 33 that is screwed with the fixing screw portion 23 of the guide bush 20 to form the screw feed mechanism 28 is formed in the lower part of the inner circumference of the cylindrical portion 31 of the valve shaft holder 30. At the same time, the upper portion of the inner circumference of the cylindrical portion 31 is brought into contact (sliding contact) with the outer periphery of the cylindrical extending portion 22 of the guide bush 20. Further, a movable stopper body 34 constituting the other side of the lower stopper mechanism 29 is integrally projected from the lower end of the outer circumference of the cylindrical portion 31.

Further, on the upper surface of the ceiling portion 32 of the valve shaft holder 30 (the surface facing the flange portion 72 of the fixing member 70 described later), as can be clearly seen with reference to FIGS. 1 and 2, a plan view is obtained. Two convex portions 35 having a substantially fan shape (here, a fan shape having a central angle of about 90 degrees) are integrally formed. Specifically, the two convex portions 35 are located on the upper surface of the ceiling portion 32 around the insertion hole 32a (in other words, around the rotation axis O of the valve shaft holder 30) and on the opposite side of the axis O (in other words, the valve shaft). It is projected upward (at a position symmetrical with respect to the rotation axis O of the holder 30), and in the meantime (in this example, an upper portion of one end surface 34a in the circumferential direction of the movable stopper body 34, that is, the axis O direction). The movable stopper body 34 has a shape in which one end surface 34a in the circumferential direction including the same position as the one end surface 34a is cut out (a substantially fan shape in a plan view (here, the central angle is about about). 90 degree fan shape) notch 36).

Since the contact area of the valve shaft holder 30 with respect to the fixing member 70 is reduced by the convex portion 35, for example, the contact resistance (rotational sliding resistance) when the valve shaft holder 30 comes into contact with the fixing member 70 is reduced. The slidability between the valve shaft holder 30 and the fixing member 70 at the time of valve opening is improved, malfunctions such as sudden deceleration, stop, and reversal of the rotor 51 are suppressed, and shaft misalignment of the valve shaft 10 is suppressed. Can be done.

Further, for example, when the valve shaft holder 30 is made of a molded product such as resin, the positions of the weld line and parting line formed at the time of molding are aligned with the position of the notch 36, that is, the weld is formed at the time of molding. By providing the notch 36 at the position where the line or parting line is formed, the contact resistance (rotational sliding resistance) can be further reduced, and the flatness of the sliding surface of the valve shaft holder 30 is increased. The misalignment of the valve shaft 10 can be further suppressed.

For example, when a gate for injecting a molding resin is provided on the opposite side of the movable stopper body 34 in the valve shaft holder 30, as described above, above the movable stopper body 34 (more specifically, the movable stopper). By providing the notch 36 in the upper portion of the one end surface 34a in the circumferential direction of the body 34), the weld line and the parting line formed at the time of molding do not exist in the convex portion 35 of the valve shaft holder 30. The contact resistance (rotational sliding resistance) can be further reduced, the flatness of the sliding surface of the valve shaft holder 30 can be increased, and the shaft deviation of the valve shaft 10 can be further suppressed.

Further, by arranging the convex portion 35 symmetrically with respect to the rotation axis O of the valve shaft holder 30 on the upper surface of the ceiling portion 32 of the valve shaft holder 30, the axial deviation of the valve shaft 10 can be suppressed more effectively. By arranging the convex portions 35 in a plurality of locations around the rotation axis O of the valve shaft holder 30, the contact area of the valve shaft holder 30 (convex portion 35) with respect to the fixing member 70 can be further reduced. Is possible.

It goes without saying that the shape, number, position, etc. of the convex portions 35 provided on the upper surface of the ceiling portion 32 of the valve shaft holder 30 are not limited to the illustrated examples, and the convex portions 35 may be omitted. good.

Further, the terrace surface (step portion) 13 formed between the upper small diameter portion 11 and the lower large diameter portion 12 of the valve shaft 10 and the lower surface of the ceiling portion 32 of the valve shaft holder 30 are described as described above. The valve shaft 10 and the valve shaft 10 and the valve shaft 10 and the said A cylindrical compression coil spring that urges the valve shaft holder 30 in a direction away from the valve shaft holder 30 in the elevating direction (axis O direction), in other words, always urges the valve shaft 10 (valve body 14) downward (valve closing direction). (Biasing member) 60 is reduced. Here, the inner diameter of the compression coil spring 60 is smaller than the hole diameter of the insertion hole 32a into which the upper small diameter portion 11 (the portion above the stepped hill surface 13) of the valve shaft 10 is inserted (in other words, the hole of the insertion hole 32a). The diameter is made larger than the inner diameter of the compression coil spring 60, and the outer diameter of the compression coil spring 60 is the hole diameter of the insertion hole 32a and the lower large diameter portion 12 of the valve shaft 10 (below the stepped hill surface 13 (stepped hill surface 13). It is made larger than the shaft diameter (diameter) of the part) of the valve body 14 side).

The valve body 40 is made of a metal cylinder such as brass or SUS. The valve body 40 has a valve chamber 40a into which a fluid is introduced and led out, and a first conduit 41a is connected and fixed to a lateral first opening 41 provided on a side portion of the valve chamber 40a by brazing or the like. An insertion hole is inserted into the ceiling of the valve chamber 40a so that the valve shaft 10 (lower large diameter portion 12) can move (slide) relative to the axis O and can rotate relative to the axis O. A fitting hole 44 is formed by fitting the lower portion (fitting portion 27) of the guide bush 20 and the guide bush 20 to be mounted and fixed, and a second opening 42 in the vertical direction provided in the lower portion of the valve chamber 40a is provided. 2 The conduit 42a is connected and fixed by brazing or the like. Further, a stepped valve opening 46 having a valve seat 46a with which the valve body 14 is brought into contact with and separated from the valve chamber 40a is formed on the bottom wall 45 between the valve chamber 40a and the second opening 42.

An annular flange plate 47 is crimped and fixed to the upper end of the valve body 40 by brazing or the like, and a cylindrical can 55 with a ceiling is attached to a step portion provided on the outer periphery of the flange plate 47. The lower end of the is sealed and joined by butt welding or the like.

A rotor 51 is rotatably arranged inside the can 55 and outside the guide bush 20 and the valve shaft holder 30, and a yoke 52a, A stator 52 composed of a bobbin 52b, a stator coil 52c, a resin mold cover 52d, and the like is arranged. A plurality of lead terminals 52e are connected to the stator coil 52c, and a plurality of lead wires 52g are connected to these lead terminals 52e via the substrate 52f and arranged in the can 55 by energizing the stator coil 52c. The existing rotor 51 rotates around the axis O.

The rotor 51 arranged in the can 55 is engaged and supported by the valve shaft holder 30, and the valve shaft holder 30 rotates (integrally) with the rotor 51.

Specifically, the rotor 51 has a double pipe configuration including an inner cylinder 51a, an outer cylinder 51b, and a connecting portion 51c that connects the inner cylinder 51a and the outer cylinder 51b at a predetermined angle position around the axis O. A vertical groove 51d extending along the axis O direction (vertical direction) is formed on the inner circumference of the inner cylinder 51a (for example, at an angle interval of 120 degrees around the axis O).

On the other hand, on the outer periphery (upper half portion) of the valve shaft holder 30, as can be clearly seen with reference to FIG. 3, a tapered surface portion 30c made of a conical base surface is provided at the upper end thereof, and the lower side of the tapered surface portion 30c. A ridge 30a extending in the vertical direction is provided so as to extend in the vertical direction (for example, at an angle interval of 120 degrees around the axis O), and upward locking surfaces 30b for supporting the rotor 51 are provided on both lower sides of the ridge 30a. Is formed.

In this way, the vertical groove 51d of the inner cylinder 51a of the rotor 51 and the ridge 30a of the valve shaft holder 30 are engaged with each other, and the lower surface of the inner cylinder 51a of the rotor 51 and the locking surface 30b of the valve shaft holder 30 are engaged with each other. By abutting, the rotor 51 is supported and fixed to the outer periphery of the valve shaft holder 30 in a state of being aligned with the valve shaft holder 30, and the valve shaft holder 30 supports the rotor 51 in the can 55 while supporting the rotor 51. Rotated with.

In this example, the rotor 51 is engaged and supported by the valve shaft holder 30 so that the upper surface of the valve shaft holder 30 is flush with or slightly above the upper surface of the inner cylinder 51a of the rotor 51. There is.

On the upper side of the rotor 51 and the valve shaft holder 30, the relative movement of the valve shaft holder 30 and the rotor 51 in the ascending / descending direction is prevented (in other words, the rotor 51 is pressed downward against the valve shaft holder 30 to prevent it from coming off. A fixing member 70 that is externally fitted and fixed is arranged at the upper end of the valve shaft 10 (upper small diameter portion 11) so as to connect the valve shaft 10 and the valve shaft holder 30 together with (locking).

The fixing member 70 is manufactured from a metal member such as brass or SUS by press working, cutting, or the like, and is fitted onto the upper end portion (large diameter connecting portion 15) of the valve shaft 10 (upper small diameter portion 11). A stepped cylindrical fixing portion 71 composed of a small diameter upper portion 71a and a large diameter lower portion 71b that are joined and fixed by press fitting, welding, welding, adhesion, etc., and a lower end portion of the fixing portion 71 (large diameter lower portion 71b). It has a disk-shaped flange portion 72 extending outward from the rotor 51 to the vicinity of the inner cylinder 51a of the rotor 51.

The lower surface of the flange portion 72 is opposed to the upper surface of the valve shaft holder 30 and the upper surface of the rotor 51 (inner cylinder 51a), and the convex portion 35 (upper surface) provided on the upper surface of the valve shaft holder 30. And the rotor 51 (the upper surface of the inner cylinder 51a) are brought into contact with each other.

As described above, the rotor 51 is sandwiched between the valve shaft holder 30 that is urged upward by the urging force of the compression coil spring 60 and the fixing member 70 (the outer peripheral portion of the flange portion 72) to prevent it from coming off. Locked.

Further, the valve shaft holder 30 moves too much upward with respect to the guide bush 20 during operation of the fixing member 70 (the large-diameter lower portion 71b of the fixing portion 71) fixed to the upper end portion of the valve shaft 10. , A return spring composed of a coil spring that urges the valve shaft holder 30 toward the guide bush 20 in order to prevent the fixing screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30 from being disengaged. 75 is exterior.

In the electric valve 1 having such a configuration, when the rotor 51 is rotated by energizing the stator 52 (stator coil 52c), the valve shaft holder 30 and the valve shaft 10 are rotated integrally with the rotor 51. At this time, the valve shaft 10 is moved up and down with the valve body 14 by the screw feed mechanism 28 including the fixed screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30, thereby causing the valve body 14 to move up and down. The gap (lift amount, valve opening degree) between the valve seat 46a and the valve seat 46a is increased or decreased to adjust the passing flow rate of a fluid such as a refrigerant.

Further, in the electric valve 1 of this example, when the valve shaft 10 is lowered and the valve body 14 is seated on the valve seat 46a, the fixed stopper fixed to the movable stopper body 34 of the valve shaft holder 30 and the guide bush 20. The body 24 is positioned away from the body 24, and then the rotor 51 is further rotated by further energizing the stator 52 (stator coil 52c), and the valve shaft holder 30 is integrally rotated and lowered. Then, the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 fixed to the guide bush 20 come into contact with each other, that is, the lower stopper mechanism 29 stops the rotation and lowering of the valve shaft holder 30. The compression coil spring 60 interposed between the valve shaft holder 30 and the valve shaft 10 is compressed so that the valve body 14 is strongly pressed against the valve seat 46a.

Specifically, when closing the electric valve 1, the stator coil 52c is energized in one direction to excite it. As a result, the rotor 51 is rotated, and accordingly, the valve shaft holder 30 is rotated relative to the guide bush 20. Here, the valve shaft holder 30 is (the extending portion 22 of the guide bush 20) by the screw feed mechanism 28 including the guide bush 20 (fixing screw portion 23) and the valve shaft holder 30 (movable screw portion 33). The valve shaft 10 descends (guided by the outer circumference), and the valve shaft 10 descends (guided by (the inner circumference) of the cylindrical portion 21 of the guide bush 20), and the valve body 14 is seated on the valve seat 46a. And close the valve opening 46. At this time, the movable stopper body 34 of the valve shaft holder 30 constituting the lower stopper mechanism 29 and the fixed stopper body 24 of the guide bush 20 are positioned apart from each other (state shown in FIG. 2).

When the stator coil 52c is further energized and excited from the above state by energizing the stator coil 52c in one direction, the valve shaft 14 is kept closed (that is, the valve shaft 10 is stationary) by the screw feed mechanism 28. The holder 30 is further lowered (against the urging force of the compression coil spring 60) (guided by (the outer periphery) of the extending portion 22 of the guide bush 20). When the valve shaft holder 30 is lowered by a predetermined amount, the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the guide bush 20 come into contact with each other, and the lower stopper mechanism 29 restricts further lowering of the valve shaft holder 30. NS. At this time, since the compression coil spring 60 interposed between the valve shaft holder 30 and the valve shaft 10 is compressed, the valve body 16 is strongly pressed against the valve seat 46a, and the valve closing property is ensured. (Fully closed state shown in FIG. 1). Further, at this time, the valve shaft holder 30 (convex portion 35) is separated from the fixing member 70 fixed to the valve shaft 10 by a predetermined gap in the elevating direction.

On the other hand, when opening the electric valve 1 from the fully closed state, the stator coil 52c is energized in the other direction to excite it. As a result, the rotor 51 is rotated relative to the guide bush 20 fixed to the valve body 40 in the direction opposite to the above, and the screw feed mechanism 28 causes the valve shaft holder 30 (extension of the guide bush 20). Ascends (guided by (outer circumference) of the installation portion 22). Here, since the valve shaft holder 30 (convex portion 35) is positioned so as to be separated from the fixing member 70 fixed to the valve shaft 10 by a predetermined gap, the valve shaft holder 30 is raised by a predetermined gap during that time (the valve shaft holder 30 is raised by a predetermined gap). While the valve body 14 is seated on the valve seat 46a and the valve opening 46 is closed (the valve shaft 10 remains stationary), the valve shaft holder 30 is raised.

From the above state, the stator coil 52c is further energized in the other direction to excite it, and when the valve shaft holder 30 rises by the predetermined gap, the convex portion 35 (upper surface) provided on the ceiling portion 32 of the valve shaft holder 30 rises. It comes into contact with the fixing member 70 (the lower surface of the flange portion 72 of the flange portion 72) fixed to the valve shaft 10, and the valve shaft holder 30 rises with the valve shaft 10 (while rotating) accordingly, and the lower end of the valve shaft 10 The valve body 14 moves upward and the valve opening 46 is opened.

As described above, in the electric valve 1 of the present embodiment, the valve shaft 10 is a portion (lower large diameter portion) below the stepped hill surface 13 on which the compression coil spring 60 as an urging member is arranged (valve body 14 side). 12) is slidably inserted into the guide bush 20, guided in the axis O direction (elevating direction) only on the lower side (valve body 14 side) of the compression coil spring 60, and the valve shaft holder 30 (insertion hole 32a). Since it does not come into contact with the inner wall of the valve shaft, the contact resistance (sliding resistance) is kept low compared to the conventional electric valve in which the valve shaft is guided by both the guide bush and the valve shaft holder above and below the urging member, for example. It is possible to improve the operability.

Further, the hole diameter of the insertion hole 32a of the valve shaft holder 30 into which the valve shaft 10 (upper small diameter portion 11) is loosely fitted is made larger than the inner diameter of the compression coil spring 60. Even if it occurs, the valve shaft 10 is guided by the compression coil spring 60, so that the contact resistance (sliding resistance) can be suppressed low and the operability can be improved. ..

In the above embodiment, the electric valve of the type in which the valve body 14 is seated on the valve seat 46a has been described. However, for example, when the valve body is in the lowest position (normally fully closed), the valve body It is detailed that the same effect as described above can be obtained even in a valve closed type electric valve in which a gap of a predetermined size is formed between the valve seat and the valve seat (that is, the valve body does not sit on the valve seat). Needless to say.

1 Motor valve 10 Valve shaft 13 Terrace surface 14 Valve body 15 Large diameter connection 20 Guide bush 21 Cylindrical part 23 Fixed thread part (male thread part)
24 Fixed stopper body 28 Thread feed mechanism 29 Lower stopper mechanism 30 Valve shaft holder 30a Protrusion 30b Locking surface 30c Tapered surface 31 Cylindrical part 32 Ceiling part 33 Movable thread part (female thread part)
34 Movable stopper body 35 Convex part 36 Notch 40 Valve body 40a Valve chamber 41 First opening 41a First conduit 42 Second opening 42a Second conduit 43 Insertion hole 44 Fitting hole 45 Bottom wall 46 Valve port 46a Valve seat 50 Stepping Motor 51 Rotor 52 Stator 55 Can 60 Compression coil spring (biasing member)
70 Fixing member 71 Fixing part 71a Small diameter upper part 71b Large diameter lower part 72 Flange part O Axis line

Claims (4)

The valve shaft provided with the valve body and
A guide bush in which the valve shaft is inserted so as to be relatively movable and relatively rotatable in the axial direction,
A valve body having a valve seat with a valve seat to which the valve body is attached and detached, and a valve body to which the guide bush is attached and fixed,
The valve shaft holder that is attached to the valve shaft and
An urging member interposed between the terrace surface formed on the valve shaft and the valve shaft holder to urge the valve body in the valve closing direction.
A fixing member fixed to the valve shaft so as to connect the valve shaft holder to the valve shaft, and the valve shaft holder is brought into contact with the valve shaft holder by the urging force of the urging member.
A motor having a rotor and a stator for rotating the valve shaft holder with respect to the guide bush,
A screw feed mechanism provided between the guide bush and the valve shaft holder for raising and lowering the valve body of the valve shaft with respect to the valve seat of the valve body in response to the rotational drive of the rotor. It is an electric valve equipped with,
A portion of the valve shaft below the terrace surface is slidably inserted into the guide bush, and the valve shaft is guided in the axial direction only on the lower side of the urging member .
The portion of the valve shaft above the terrace surface is inserted into the insertion hole provided in the valve shaft holder with a predetermined gap.
The urging member is interposed between the terrace surface and the valve shaft holder so as to be extrapolated to a portion of the valve shaft above the terrace surface.
An electric valve characterized in that the hole diameter of the insertion hole is larger than the inner diameter of the urging member. The valve shaft provided with the valve body and
A guide bush in which the valve shaft is inserted so as to be relatively movable and relatively rotatable in the axial direction,
A valve body having a valve seat with a valve seat to which the valve body is attached and detached, and a valve body to which the guide bush is attached and fixed,
The valve shaft holder that is attached to the valve shaft and
An urging member interposed between the terrace surface formed on the valve shaft and the valve shaft holder to urge the valve body in the valve closing direction.
A fixing member fixed to the valve shaft so as to connect the valve shaft holder to the valve shaft, and the valve shaft holder is brought into contact with the valve shaft holder by the urging force of the urging member.
A motor having a rotor and a stator for rotating the valve shaft holder with respect to the guide bush,
A screw feed mechanism provided between the guide bush and the valve shaft holder for raising and lowering the valve body of the valve shaft with respect to the valve seat of the valve body in response to the rotational drive of the rotor. It is an electric valve equipped with,
A portion of the valve shaft below the terrace surface is slidably inserted into the guide bush, and the valve shaft is guided in the axial direction only on the lower side of the urging member .
The portion of the valve shaft above the terrace surface is inserted into the insertion hole provided in the valve shaft holder with a predetermined gap.
A portion of the valve shaft to which the fixing member is fixed has a larger diameter than a portion of the valve shaft that is inserted into the insertion hole and a smaller diameter than the hole diameter of the insertion hole. valve. The urging member is interposed between the terrace surface and the valve shaft holder so as to be extrapolated to a portion of the valve shaft above the terrace surface.
The electric valve according to claim 2, wherein the hole diameter of the insertion hole is larger than the inner diameter of the urging member. The electric motor according to claim 1 or 3, wherein the outer diameter of the urging member is larger than the hole diameter of the insertion hole and the shaft diameter of the portion of the valve shaft below the terrace surface. valve.

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