Motor-operated valve

Abstract

To provide an electric valve excellent in a flow rate control property.SOLUTION: An electric valve 100 is equipped with a valve body 10 that has a valve seat 11b, a cylindrical can 45 that is joined with the valve body 10, a rotor 30 that is disposed inside the can 45, a valve shaft 20 that integrally rotates with the rotor 30, a guide member 15 in which the valve shaft 20 is inserted, a valve shaft lifting driving mechanism 22 that is provided between the guide member 15 and the valve shaft 20, and a valve body 25 that is coupled to the valve shaft 20, approaches and separates from the valve seat 11b together with the lifting of the valve shaft 20, and has a curved seat surface bulging toward the valve seat 11b.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to motorized valves. [Background technology]

[0002] Conventionally, there is known a type of motor-operated valve that opens and closes a valve port by moving a valve element connected to a rotating valve shaft toward and away from a valve seat of a valve seat member along the axial direction of the rotating shaft using a screw feed mechanism that utilizes the rotation of a rotor, as in Patent Document 1. In the motor-operated valve of Patent Document 1, a seating surface that comes into contact with the valve seat is formed on part of the peripheral surface of the tip of a truncated cone on the outer surface of the rod-shaped valve element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-172839 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if there is a problem with the screw feed mechanism of the motor-operated valve, for example, if the male and female threads become loose, the rotation shaft and the axis of the valve disc may cross, i.e., the axis of the valve disc may become misaligned. When the axis of the valve disc becomes misaligned, the axis of the valve disc is inclined relative to the surface of the valve orifice.

[0005] In Patent Document 1, the seating surface of the valve disc is a peripheral surface of a truncated cone shape, so the shape of the seating surface is linear in a cross section including the rotation axis. In addition, the shape of the surface of the valve seat corresponding to the seating surface is also linear in the cross section. Therefore, if the axis of the valve disc is inclined relative to the surface of the valve port due to axial misalignment of the valve disc, when the valve shaft reaches the lowest position toward the valve seat, a part of the peripheral surface of the seating surface approaches the valve seat, while the other part of the seating surface is likely to move away from the valve seat.

[0006] In other words, when the axial misalignment of the valve disc occurs, the peripheral surface of the seating surface does not contact the valve seat evenly in the circumferential direction, so in the case of Patent Document 1, where the shape of the seating surface in the cross section is linear, the gap between the seating surface of the valve disc and the valve seat tends to become wide. As a result, the sealing performance of the valve seat decreases, causing leakage of the fluid entering and exiting the motor-operated valve from the valve port, i.e., so-called valve leakage. This reduces the flow controllability of the motor-operated valve.

[0007] In view of the above, the present disclosure provides a motor-operated valve with excellent flow controllability. [Means for solving the problem]

[0008] The motor-operated valve according to the first embodiment comprises a valve body having a valve seat, a cylindrical can joined to the valve body, a rotor arranged inside the can, a valve stem rotating integrally with the rotor, a guide member into which the valve stem is inserted, a valve stem lifting drive mechanism provided between the guide member and the valve stem, and a valve disc connected to the valve stem, which moves toward and away from the valve seat in conjunction with the lifting and lowering of the valve stem and has a curved seating surface that bulges toward the valve seat.

[0009] In the motor-operated valve according to the first aspect, the valve body has a curved seating surface that bulges toward the valve seat. That is, the shape of the seating surface in the cross section is an arc. Therefore, compared with a valve body having a peripheral surface of a truncated cone shape, in which the length of the linear portion of the seating surface in the cross section is the length of a chord corresponding to the same arc as the arc of the seating surface of the motor-operated valve according to the first aspect, even if the valve body is tilted due to axial misalignment, the distance between the seating surface and the valve seat is shorter. As a result, even if a gap is formed between the seating surface of the valve body and the valve seat, the gap can be kept small. Therefore, the sealing performance of the valve seat can be improved, and valve leakage can be suppressed.

[0010] In a second aspect, in the motor-operated valve of the first aspect, a rotation support member having a curved base portion that supports the base of the valve body so that the tip of the valve body can rotate around the base side of the valve body.

[0011] In the second embodiment, the tip of the valve disc can rotate around the base of the valve disc. Even if the valve disc is misaligned, the tip of the valve disc can easily come into contact with the valve seat by rotating around the base while the valve disc descends. In other words, the range of tilt that can be accommodated when the valve disc is tilted due to the misalignment of the valve disc is expanded.

[0012] In a third aspect, in the motor-operated valve according to the second aspect, in a cross section including the rotation axis, the center of a first imaginary circle including the curved outline of the curved base portion of the rotation support member and the center of a second imaginary circle including the curved outline of the curved seating surface of the valve body overlap at the same position.

[0013] In the third embodiment, in a cross section including the rotation axis, the center of an imaginary circle including the contour curve of the curved portion of the rotation support member and the center of an imaginary circle including the contour curve of the curved seating surface of the valve body overlap at the same position. Therefore, even if the tip of the valve body rotates, the curved seating surface moves on the same circumference, so the valve body can easily seat on the valve seat reliably. Therefore, even if the axis of the valve body is misaligned, the valve leakage is effectively suppressed.

[0014] In a fourth aspect, in the electric valve according to the second or third aspect, a curved sliding protrusion is provided on the base of the valve body, protruding toward the surface that contacts the base portion of the rotating support member, and the base portion of the rotating support member has a curved base recess on the surface that supports the base of the valve body, which fits into the sliding protrusion.

[0015] In a fourth embodiment, the base of the valve body has a curved sliding protrusion protruding toward a surface that contacts the base of the rotation support member, and the base of the rotation support member has a curved base recess that fits with the sliding protrusion on a surface that supports the base of the valve body.

[0016] On the other hand, when a recess that fits with the protrusion of the base is provided on the base side, in order to ensure the range of motion of the base of the valve body, which is the rotating side, it is necessary to provide a tapered portion having a thickness equal to or greater than the depth of the recess at the end of the base on the base side. In other words, the length of the base is extended by the amount of the tapered portion. In addition, the tapered portion is often required from the viewpoint of suppressing a decrease in the strength of the base due to the recess.

[0017] Therefore, when the radius of curvature of the recess is the same, the length of the valve body can be shortened by the amount corresponding to the unnecessary length of the reduced diameter portion compared to when the recess is provided on the base side. As a result, the overall length of the motor-operated valve can be reduced. Also, the cost of the components can be reduced.

[0018] In a fifth aspect, in the electric valve according to the second or third aspect, a curved base protrusion protruding toward a base of the valve body is provided on the base portion of the rotating support member, and the base of the valve body has a reduced diameter portion on the surface that comes into contact with the base portion of the rotating support member, and a sliding recess that fits into the base protrusion is formed therein.

[0019] In the fifth embodiment, the base of the rotation support member is provided with a curved base protrusion that protrudes toward the base of the valve body. The base of the valve body has a reduced diameter portion on the surface that contacts the base of the rotation support member, in which a sliding recess that fits into the base protrusion is formed as a curved portion. Therefore, compared to the case where a recess is provided on the side of the base, there is no need to partially thin the thickness of the base, and the strength of the base is not reduced.

[0020] In a sixth aspect, the motor-operated valve according to any one of the first to fifth aspects further comprises a stator attached to the outside of the can and configured to rotate the rotor. Effect of the Invention

[0021] According to the motor-operated valve of the present disclosure, a motor-operated valve with excellent flow rate controllability can be provided. [Brief description of the drawings]

[0022] [Figure 1]1 is a cross-sectional view illustrating an embodiment of a motor-operated valve according to the present disclosure, taken along a plane including a rotation axis. [Diagram 2] 4 is a diagram illustrating a contact portion of a rotation support member and a valve body in the motor-operated valve according to the embodiment of the present invention by cutting away a valve seat member. FIG. [Diagram 3] FIG. 3 is an enlarged view of part D in FIG. [Figure 4] 1 is a cross-sectional view illustrating the operation of the motor-operated valve according to the present embodiment (part 1). FIG. [Diagram 5] FIG. 2 is a cross-sectional view illustrating the operation of the motor-operated valve according to the embodiment (part 2). [Figure 6] FIG. 4 is a cross-sectional view for explaining the operation of the motor-operated valve according to the embodiment (part 3). [Figure 7] FIG. 11 is a cross-sectional view illustrating a motor-operated valve according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present embodiment will be described below. In the following description of the drawings, the same or similar parts are given the same or similar symbols. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device and each member, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined by taking into consideration the following description. In addition, there are parts in which the dimensional relationships and ratios differ between the drawings.

[0024] <Configuration of motor-operated valve> 1, the motor-operated valve 100 according to this embodiment includes a valve body 10, a can 45, a rotor 30, a stator 50, a valve stem 20, a guide member 15, a valve stem lifting and lowering drive mechanism 22, and a valve body 25. The motor-operated valve 100 further includes a rotation support member 42.

[0025] (Valve stem lift mechanism) In this embodiment, the valve shaft lifting drive mechanism 22 for lifting the valve shaft 20 may be broadly composed of the rotor 30, the stator 50, and the female thread portion 15i of the guide member 15 and the male thread portion 21e of the valve shaft 20. In the narrower sense, the valve shaft lifting drive mechanism 22 has a feed screw mechanism and may be composed of the female thread portion 15i of the guide member 15 and the male thread portion 21e of the valve shaft 20. That is, in this embodiment, the valve shaft 20 is a movable screw and the guide member 15 is a fixed screw. The valve shaft lifting drive mechanism 22 is provided between the guide member 15 and the valve shaft 20.

[0026] (Valve body) The valve body 10 is a cylindrical member with an open top and a closed bottom. The valve body 10 has a valve seat 11b. The valve body 10 can be manufactured by pressing a metal plate material, for example. A valve seat member 11 having a valve port 11a, which is an orifice, and a valve seat 11b is fixed to the bottom 10b of the valve body 10 by brazing or the like.

[0027] The lower part of the guide member 15 is inserted into the upper part of the valve body 10. The flange-shaped disk 18 is placed on the upper part of the valve body 10 in Fig. 1. As shown by the welded part 46 in Fig. 1, the lower end part of the can 45 is fixed by welding to the step part formed by the flange-shaped disk 18 and the upper part of the valve body 10.

[0028] A first inlet / outlet 6 made of a pipe joint is joined by brazing or the like to the left side of the valve chamber 12 of the valve body 10 in Fig. 1. Similarly, a second inlet / outlet 7 made of a pipe joint is joined by brazing or the like to the valve seat member 11.

[0029] (Can) The can 45 is cylindrical. The lower end of the can 45 in FIG.

[0030] (Rotor) The rotor 30 is disposed inside the can 45. The rotor 30 has a cylindrical magnet 31 and a disk-shaped ceiling portion 32 integrally joined to the magnet 31. A hole is formed in the center of the ceiling portion 32 to fit into the upper small diameter portion 21b of the valve shaft 20. That is, the rotor 30 is fixed to the upper portion of the valve shaft 20 in FIG. 1. Also, as shown by the welded portion 33 illustrated in FIG. 1, the ceiling portion 32 is fixed to the upper small diameter portion 21b by welding while being placed on the valve closing direction movable stopper 35 screwed to the male thread portion 21e.

[0031] (Stator) The stator 50 fits onto the outer periphery of the can 45. That is, the stator 50 is disposed outside the can 45. The stator 50 has a yoke 51, a bobbin 52, a coil 53, a resin mold 54, etc. A positioning fixture 58 is provided on the bottom of the stator 50. The stator 50 is positioned and fixed at a predetermined position relative to the valve body 10 by the positioning fixture 58. The stator 50 and the rotor 30 constitute, for example, a stepping motor. The stator 50 drives the rotor 30 to rotate.

[0032] In the motor-operated valve 100 according to this embodiment, when the rotor 30 rotates, the valve shaft 20 rotates integrally with the rotation of the rotor 30. When the valve shaft 20 rotates, the valve shaft 20 moves up and down together with the valve body 25 by the screw feed mechanism. The flow rate of the refrigerant passing through is adjusted by the movement of the valve body 25 up and down. Note that, although the embodiment has been described as an example in which the fluid is a refrigerant, in the present disclosure, the fluid is not limited to a refrigerant.

[0033] (valve stem) The valve shaft 20 rotates integrally with the rotor 30. The valve shaft 20 is screwed into the female thread portion 15i formed in the small diameter portion 15b of the guide member 15. Specifically, the valve shaft 20 includes a male thread member 21, a valve holder 23, and a valve body 25. The male thread member 21 has a male thread portion 21e that is screwed into the female thread portion 15i of the guide member 15, and an upper small diameter portion 21b whose diameter is smaller than the outer diameter of the male thread portion 21e.

[0034] (Valve holder) The valve holder 23 is a cylindrical member. The ceiling hole portion of the valve holder 23 is connected in a fixed state to the crimped portion 21c located at the lower end of the male thread member 21 in FIG. 1. The valve holder 23 has a ceiling portion 23b slidably inserted into the large diameter cylindrical body portion 15a of the guide member 15. The large diameter cylindrical body portion 15a of the guide member 15 corresponds to the cylindrical portion of the present disclosure.

[0035] Inside the support cylindrical portion 23a of the valve holder 23, a ring-shaped holding portion 27 is fixed to the lower end portion of the valve holder 23 in Fig. 1 by press-fitting, welding, or the like. Also, a ring-shaped washer 28 is arranged on the upper side of the holding portion 27 in Fig. 1 with the position of its central hole aligned with the position of the central hole of the holding portion 27.

[0036] (Guide material) The stem guide serving as the guide member 15 has a large-diameter cylindrical body portion 15a into which the valve stem 20 is inserted. The guide member 15 has a flange-shaped disk 18 fixed by welding or the like to the upper portion of the upper end surface of the valve body 10 in FIG.

[0037] (Valve body) As shown in Fig. 1, the upper part of the valve body 25 is slidably inserted into the lower part of the support cylindrical part 23a of the valve holder 23. The valve body 25 is connected to the valve shaft 20 inside the large diameter cylindrical body part 15a of the guide member 15. The valve body 25 moves toward and away from the valve seat 11b in conjunction with the elevation and lowering of the valve shaft 20. As shown in Fig. 2, the valve body 25 has a base part 25A and a tip part 25B.

[0038] (base) A flange 25c having an outer diameter larger than the diameter of the base 25A is provided on the base 25A of the valve body 25. The flange 25c is located above the washer 28. In this embodiment, the flange 25c is a push nut attached to the base 25A. In the present disclosure, the flange may be made integral with the base 25A, for example.

[0039] The base 25A of the valve body 25 has a reduced diameter portion 25d in which a sliding recess 25d1 that fits with the base protrusion 44b is formed on the surface of the side that contacts the base portion 44a of the contact portion 44 of the rotation support member 42. The base 25A of the valve body 25 is slidable relative to the contact portion 44 of the rotation support member 42.

[0040] (Tip) 1, the tip 25B of the valve body 25 has a truncated cone-shaped portion 25a to be inserted into the valve port 11a, and a cylindrical body portion 25b having a larger diameter than the truncated cone-shaped portion 25a. The valve body 25 has a curved seating surface 25e on a part of the circumferential surface of the tip 25B that bulges toward the valve seat 11b.

[0041] (Seating surface) 2 and 3, in this embodiment, the curved seating surface 25e is formed on a single spherical surface. Note that in the present disclosure, the curved seating surface 25e is not limited to a spherical surface, and may be any curved surface such as an elliptical surface or a conical surface.

[0042] In addition, in this embodiment, the contour of the curved seating surface 25e illustrated in the drawings is drawn smoothly. However, in the present disclosure, the curved seating surface 25e may be microscopically configured with a plurality of steps.

[0043] (Rotational support member) The rotation support member 42 is disposed on the upper surface of the valve body 25 in Fig. 1. A circular, thick plate-like spring receiving member 26 having a flange-shaped portion 26b is disposed on top of the rotation support member 42 in Fig. 1. The compression coil spring 24 for valve closing and buffering is disposed in a compressed state between the flange-shaped portion 26b of the spring receiving member 26 and the ceiling portion 23b of the valve holder 23.

[0044] In other words, the lower winding end of the compression coil spring 24 in Fig. 1 comes into contact with the spring receiving member 26. A rotation support member 42 is disposed between the spring receiving member 26 and the valve body 25. The valve body 25 is constantly biased downward in Fig. 1 by the compression coil spring 24 via the rotation support member 42.

[0045] The rotation support member 42 has a contact portion 44 and a displacement absorbing portion 47. The rotation support member 42 allows the tip 25B of the valve body 25 to rotate around the side of the base portion 25A of the valve body 25 as the center.

[0046] (Contact part) The contact portion 44 has a base portion 44a and a base protrusion portion 44b provided on the base portion 44a. The contact portion 44 in this embodiment is, for example, a disk-shaped washer. Note that in the present disclosure, the contact portion 44 is not limited to a washer and can be appropriately changed as long as it can rotatably support the valve body 25 in a state of contact with the valve body 25.

[0047] (Base, base protrusion) The base portion 44a is a disk-shaped member. The base protrusion portion 44b is provided at the center of the lower surface of the base portion 44a. As shown in Fig. 2, the surface of the base protrusion portion 44b (i.e., the lower surface in Fig. 2) is curved.

[0048] The base protrusion 44b protrudes toward the base 25A of the valve body 25. The base portion 44a supports the base 25A of the valve body 25 in a state in which the sliding recess 25d1 of the valve body 25 is fitted into the curved surface of the base protrusion 44b.

[0049] In the present embodiment, the base portion 44a and the base protrusion portion 44b are integrally manufactured. Note that in the present disclosure, the base portion 44a and the base protrusion portion 44b may be manufactured separately and then integrated by being joined.

[0050] (Displacement absorbing part) The displacement absorbing portion 47 absorbs the circumferential sliding of the valve body 25, i.e., the circumferential displacement. The displacement absorbing portion 47 in this embodiment is, for example, a thrust bearing. Note that in the present disclosure, the displacement absorbing portion 47 is not limited to a thrust bearing. Also, in the present disclosure, the displacement absorbing portion 47 is not essential.

[0051] In this embodiment, the circumferential sliding of the valve body 25 is absorbed not by the contact surface of the contact portion 44 with the washer, but by the thrust bearing and the spring receiving member 26 as the displacement absorbing portion 47. In other words, no axial load is applied to the contact portion 44 which directly contacts the valve body 25. This makes it possible to achieve both durability of the contact portion 44 and the ability to align the center of rotation of the valve body 25 on the rotation axis O in the event of axial misalignment.

[0052] (First imaginary circle, second imaginary circle) As shown in FIG. 2, in the present embodiment, in a cross section including the rotation axis O, when the rotation axis O and the axis of the valve body 25 are aligned without misalignment, the center B1 of the first imaginary circle C1 and the center B2 of the second imaginary circle C2 overlap at the same position. That is, the first imaginary circle C1 and the second imaginary circle C2 are concentric circles. The first imaginary circle C1 includes the curved contour of the sliding recess 25d1 of the valve body 25 and the curved base portion 44a of the rotation support member 42. The second imaginary circle C2 includes the curved contour of the curved seating surface 25e of the valve body 25. In the present disclosure, the position of the center of the first imaginary circle C1 and the position of the center of the second imaginary circle C2 may be different.

[0053] <Operation of the motor-operated valve> Next, the operation of the motor-operated valve 100 according to this embodiment will be described with reference to FIGS.

[0054] (Normal operation) In the motor-operated valve 100 according to this embodiment, the rotor 30 and the valve shaft 20 rotate, for example, clockwise in plan view, by supplying a pulse that forms a valve closing direction drive pattern to the stator 50. Then, the valve shaft 20 and the valve closing direction movable stopper 35 are lowered while rotating by the valve shaft lifting and lowering drive mechanism 22 that uses a screw feed consisting of the female thread portion 15i and the male thread portion 21e. Then, the valve disc 25 is seated on the valve seat member 11, thereby closing the valve port 11a.

[0055] At the point when the valve port 11a is closed, the closing direction movable stopper 35 has not yet come into contact with the closing direction fixed stopper 55, and as a result, the rotor and valve stem continue to rotate and descend. Furthermore, the pulse supply continues until the compression coil spring 24 is compressed by a predetermined amount. Therefore, with the valve body 25 seated on the valve seat member 11, the rotor 30, valve stem 20, valve holder 23, etc. continue to rotate and descend.

[0056] As the valve stem 20 and the valve holder 23 descend relative to the valve body 25, the compression coil spring 24 is compressed. This absorbs the downward force of the valve stem 20 and the valve holder 23. When the compression amount of the compression coil spring 24 reaches a predetermined amount, the valve closing direction movable stopper 35 comes into contact with the valve closing direction fixed stopper 55. The rotor 30 and the valve stem 20 reach their lowest positions. As a result, even if the supply of pulses forming the valve closing direction drive pattern to the stator 50 continues, the descent of the rotor 30 and the valve stem 20 is forcibly stopped. This creates a valve-closed state, i.e., a fully closed state of the valve port 11a.

[0057] Even after the valve orifice 11a is closed by the valve element 25, the rotor 30, the valve shaft 20, and the valve holder 23 continue to rotate downward until the compression coil spring 24 is compressed by a predetermined amount. Therefore, the valve element 25 is pressed against the valve seat member 11, so that valve leakage, etc. can be reliably prevented.

[0058] On the other hand, when a pulse forming a valve opening direction drive pattern is supplied to the stator 50 from the fully closed state of the valve seat 11b, the rotor 30 and the valve shaft 20 rotate in the opposite direction, for example, counterclockwise. Then, the valve shaft lifting drive mechanism 22 lifts the rotor 30, the valve shaft 20, the valve holder 23, and the valve opening direction movable stopper 36 while rotating. Then, the compression coil spring 24 expands by a predetermined amount and returns to the original set state. Also, the valve disc 25 leaves the valve seat member 11, opening the valve port 11a.

[0059] The lift amount of the valve element 25 (i.e., the flow rate, which is the valve opening degree) is determined according to the number of pulses supplied to the stator 50. If the supply of pulses continues, the valve port 11a will eventually be fully open. Also, the valve opening direction movable stopper 36 comes into contact with the valve opening direction fixed stopper 56. This forcibly stops the rotation and ascent of the rotor 30, valve shaft 20, and valve holder 23.

[0060] (Operation in misaligned state) However, as shown in Fig. 4, when a malfunction occurs in the engagement of the threads, for example, when the male and female threads of the valve stem lifting and lowering drive mechanism 22 become loose, an axial deviation occurs in the valve body 25. Fig. 4 shows an example of an axis A1 of the valve body 25 that is shifted in parallel to the right side from the rotation axis O.

[0061] Next, as shown in FIG. 5, the valve element 25 in the axis-misaligned state descends, whereby the peripheral surface of the tip 25B of the valve element 25 comes into uneven contact with part of the surface of the ring-shaped valve seat 11b, creating a so-called uneven contact state.

[0062] Next, as shown in Fig. 6, when the valve disc 25 continues to move down while maintaining the partial contact state, the tip 25B rotates due to the force applied from the valve seat 11b. Fig. 6 illustrates a state in which the axis A2 of the rotated valve disc 25 intersects with the rotation axis O. The valve disc 25 is seated on the valve seat 11b in a state inclined with respect to the rotation axis O.

[0063] In this embodiment, since the seating surface 25e of the valve body 25 is curved, the distance between the seating surface 25e and the valve seat 11b is shorter than when the shape of the seating surface in the cross section is linear. Therefore, even if the seating surface 25e is not entirely in contact with the valve body 25, as in the case of the left seating surface 25e located above the right seating surface 25e in the valve body 25 in Fig. 6, the gap formed between the seating surface 25e and the valve seat 11b can be covered or the gap can be reduced.

[0064] In addition, in this embodiment, since the seating surface 25e of the valve body 25 is curved, the valve body 25 is easily rotated around the base 25A side so that the tip 25B is further tilted with respect to the rotation axis O by receiving a downward force after being seated. In this embodiment, the truncated cone-shaped portion 25a of the tip 25B in FIG. 6 rotates clockwise. Therefore, the circumferential surface of the truncated cone-shaped portion 25a of the valve body 25 on the left side in FIG. 6 approaches the left valve seat 11b. That is, the circumferential surface of the truncated cone-shaped portion 25a can be brought into contact with the valve seat 11b, or the gap between the tip 25B and the valve seat 11b can be reduced.

[0065] (Action and effect) In the motor-operated valve 100 according to the present embodiment, the valve body 25 has a curved seating surface 25e that bulges toward the valve seat 11b. That is, the shape of the seating surface 25e in the cross section is an arc shape. Here, as a comparative example, a valve body having a peripheral surface of a truncated cone shape, for example, in which the length of the linear part of the seating surface in the cross section is the length of a chord corresponding to the same arc as the arc of the seating surface 25e of the motor-operated valve 100 according to the present embodiment, is considered. In the present embodiment, the distance between the seating surface 25e and the valve seat 11b is shorter than in the comparative example, even if the valve body 25 is tilted in the event of axial misalignment. As a result, even if a gap is formed between the seating surface 25e of the valve body 25 and the valve seat 11b, the gap can be kept small. Therefore, the sealing property of the valve seat 11b can be improved, and valve leakage can be suppressed. Thus, the motor-operated valve 100 with excellent flow controllability can be realized.

[0066] In this embodiment, the tip 25B of the valve body 25 can rotate around the base 25A side of the valve body 25. Even if the axis of the valve body 25 is misaligned, the tip 25B of the valve body 25 can easily come into contact with the valve seat 11b by the valve body 25 descending while the tip 25B of the valve body 25 rotates around the base 25A side. That is, the tilt range that can be accommodated when the valve body 25 is tilted due to the axis misalignment of the valve body 25 is expanded.

[0067] In this embodiment, in a cross section including the rotation axis O, the center of an imaginary circle including the curved contour of the curved portion of the rotation support member 42 and the center of an imaginary circle including the curved contour of the curved seating surface 25e of the valve body 25 overlap at the same position. Therefore, even if the tip 25B of the valve body 25 rotates, the curved seating surface 25e moves on the same circumference, so that the valve body 25 can be easily and reliably seated on the valve seat 11b. Therefore, even if the axial misalignment of the valve body 25 occurs, the valve leakage is effectively suppressed.

[0068] In this embodiment, the base portion 44a of the rotation support member 42 is provided with a curved base protrusion 44b that protrudes toward the base portion 25A of the valve body 25. The base portion 25A of the valve body 25 has a reduced diameter portion 25d in which a sliding recess 25d1 that fits into the base protrusion 44b is formed as a curved portion on the surface on the side that contacts the base portion 44a of the rotation support member 42. Therefore, compared to the case where a recess is provided on the side of the base portion 44a, there is no need to partially reduce the thickness of the base portion 44a, and therefore the strength of the base portion 44a is not reduced.

[0069] <Other embodiments> Although the present disclosure has been described with reference to the above disclosed embodiments, the descriptions and drawings forming a part of this disclosure should not be construed as limiting the present disclosure.

[0070] (Modification) For example, in the present disclosure, as in the motor-operated valve 100A according to a modified example illustrated in Fig. 7, the base 25A of the valve body 25 may be provided with a curved sliding protrusion 25f that protrudes toward the surface that contacts the base portion 44a of the rotation support member 42. In addition, the base portion 44a of the rotation support member 42 may have a curved base recess 44c that fits with the sliding protrusion 25f on the surface that supports the base 25A of the valve body 25.

[0071] Even in the case of the motor-operated valve 100A in Fig. 7, the tip 25B of the valve body 25 can be rotated by the sliding protrusion 25f and the curved base recess 44c that fits in it. Other configurations in the modified example are similar to the members with the same names in the present embodiment illustrated in Figs. 1 to 6, so duplicated explanations will be omitted. Also in the modified example, as in the case of the present embodiment, it is possible to realize a motor-operated valve 100A with excellent flow rate controllability.

[0072] When the sliding recess 25d1 that fits with the protruding portion of the base portion 44a is provided on the side of the base portion 25A, in order to ensure the range of motion of the base portion 25A of the valve body 25, which is the rotating side, it is necessary to provide a reduced diameter portion 25d at the end of the base portion 44a side of the base portion 25A. The reduced diameter portion 25d has a thickness equal to or greater than the depth of the sliding recess 25d1. In other words, the length of the base portion 25A is extended by the reduced diameter portion 25d. In addition, the reduced diameter portion 25d is often required from the viewpoint of suppressing a decrease in strength of the base portion 25A caused by the sliding recess 25d1.

[0073] Therefore, when the radius of curvature of the recess is the same, the length of the valve body 25 can be shortened by the amount that the length of the reduced diameter portion 25d is unnecessary in the modified example, compared to the case where the sliding recess 25d1 is provided on the side of the base portion 25A. As a result, the overall length of the motor-operated valve 100A can be reduced. Also, the cost of the components can be reduced. Other effects of the modified example are the same as those of the present embodiment.

[0074] The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specifying matters in the claims that are appropriate from the above description. [Explanation of symbols]

[0075] 10 Valve body 11 Valve seat member 11a Benguchi 11b Valve seat 12 Valve chamber 15 Guide member (guide stem) 15a Large diameter cylindrical body 15i Female thread 20 Valve stem 21 Male threaded member 21e Male thread 22 Valve stem lifting mechanism 23 Valve holder 23a Support cylinder 23b Ceiling section 25 Valve body 25A base 25B Tip 25a Cone-shaped section 25b Cylindrical body 25c collar 25d Reduced diameter part 25d1 Sliding recess 25e Seating surface 25f Sliding protrusion 28 Washer 30 rotors 42 Rotating support member 44 Contact part 44a Base 44b Base protrusion 45 Can 47 Displacement absorbing section 50 Stator 100,100A Motorized Valve A1, A2 Valve shaft B1 Center of the first virtual circle B2 Center of the second imaginary circle C1 First virtual circle C2 Second imaginary circle O Rotation axis

Claims

1. a valve body having a valve seat; A cylindrical can joined to the valve body; A rotor disposed inside the can; a valve stem that rotates integrally with the rotor; a guide member into which the valve stem is inserted; a valve stem lifting mechanism provided between the guide member and the valve stem; a rod-shaped valve body connected to the valve stem, the rod-shaped valve body having a curved seating surface that moves toward and away from the valve seat in response to the elevation and lowering of the valve stem and that bulges toward the valve seat; a rotation support member including: a contact portion having a curved base portion supporting the base of the valve body so that the tip of the valve body can rotate around the base side of the valve body; and a displacement absorbing portion provided on the opposite side of the contact portion to the valve body in the axial direction and absorbing circumferential displacement of the valve body; An electrically operated valve comprising:

2. In a cross section including the rotation axis, a center of a first imaginary circle including a curved contour of the curved base portion of the rotation support member and a center of a second imaginary circle including a curved contour of the curved seating surface of the valve body overlap at the same position. The motor-operated valve according to claim 1.

3. a curved sliding protrusion protruding toward a surface of the valve body that contacts the base portion of the rotation support member is provided at the base portion of the valve body, The base portion of the rotation support member has a curved base recess that fits with the sliding protrusion on a surface that supports the base portion of the valve body. The motor-operated valve according to claim 1 or 2.

4. The base portion of the rotation support member is provided with a curved base protrusion portion that protrudes toward the base portion of the valve body, The base portion of the valve body has a reduced diameter portion on a surface that contacts the base portion of the rotation support member, the reduced diameter portion having a sliding recess that fits with the base protrusion portion. The motor-operated valve according to claim 1 or 2.

5. a stator attached to the outside of the can and configured to rotate the rotor; The motor-operated valve according to claim 1.

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