Motor-operated valve

Abstract

To suppress torque loss while making a device compact.SOLUTION: The motor-operated valve 1 includes a cylindrical can 60, a cylindrical rotor 40 disposed outside the can 60, a valve body 20 moving in accordance with rotation of the rotor 40, and a stator 90 disposed inside the can 60, the stator 90 including a plurality of plate-shaped pole teeth 90 having a flat facing surface 92 facing an inner wall surface of the can 60, and a protrusion portion 97 partially protruding from the facing surface 92 toward the inner wall surface 60A of the can 60 from the facing surface 92 is provided in one or more of the pole teeth 90.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, an electric valve is known that includes a valve body, a can, a rotor, and a stator, as disclosed in Patent Document 1. The rotor and stator form a motor. The can is cylindrical and is joined to the valve body. The rotor is disposed inside the can. The stator is cylindrical and is disposed coaxially outside the can. The electric valve in Patent Document 1 is an outer motor type. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-83453 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, when the stator has a plurality of pole teeth, the pole teeth are usually in the form of flat plates. When the stator is positioned outside the can, as in Patent Document 1, it is relatively easy to bring the inner surfaces of the flat, plate-shaped pole teeth into contact with the outer wall surface of the can, even if the outer wall surface of the cylindrical can is curved.

[0005] However, in Patent Document 1, the outer diameter of the motor-operated valve tends to be large due to the stator being placed outside the can, which increases the overall space required to place the motor-operated valve, leaving room for improvement in Patent Document 1 in terms of making the device more compact.

[0006] To make the device more compact, it is possible to place the stator inside the can, in other words, to realize an inner motor type motor-operated valve. However, when the stator is placed inside the can, the width of the gap in the circumferential center between the curved inner wall surface of the cylindrical can and the outer surfaces of the flat, plate-like pole teeth facing this inner wall surface becomes larger than when the stator is placed outside the can. For this reason, simply placing the stator inside the can in an inner motor type motor-operated valve raises concerns about motor torque loss due to the gap.

[0007] In view of the above, the present disclosure provides an electric valve that can reduce torque loss while making the device more compact. [Means for solving the problem]

[0008] The electric valve according to the first embodiment comprises a cylindrical can, a cylindrical rotor arranged outside the can, a valve body that moves in accordance with the rotation of the rotor, and a stator arranged inside the can, the stator having a plurality of plate-shaped pole teeth with flat opposing surfaces that face the inner wall surface of the can, and one or more of the pole teeth having a protrusion that protrudes partially from the opposing surface toward the inner wall surface of the can beyond its surroundings.

[0009] In the motor-operated valve according to the first aspect, even if the stator is disposed inside the can, the protrusions allow the width of the gap between the stator and the can to be made smaller than in the case of pole teeth whose opposing surfaces are generally flat, for example. As a result, torque loss can be suppressed while the device is made more compact.

[0010] In a second aspect, in the motor-operated valve according to the first aspect, a portion of the protrusion that faces the inner wall surface of the can is curved.

[0011] In the second aspect, even if the protrusion comes into contact with the inner wall surface of the can, the can or the pole teeth are unlikely to be damaged.

[0012] A third aspect is the motor-operated valve according to the first or second aspect, wherein the protrusion is in contact with the inner wall surface of the can.

[0013] In the third aspect, the protrusion comes into contact with the inner wall surface of the can, thereby enhancing the effect of suppressing torque loss compared to when a gap is formed between the stator and the can without forming a protrusion.

[0014] In a fourth aspect, in the motor-operated valve according to any one of the first to third aspects, when the opposing surfaces are viewed from the front toward the central axis, the pole teeth are symmetrical with respect to a center line parallel to the central axis.

[0015] In the fourth aspect, the torque loss is more effectively suppressed than in the case where the pole teeth are asymmetric with respect to a center line parallel to the center axis, for example. [Effects of the Invention]

[0016] According to the present disclosure, it is possible to provide a motor-operated valve that can reduce torque loss while making the device more compact. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view illustrating an embodiment of the motor-operated valve according to the present disclosure, taken along a plane including a central axis that is a rotation axis. [Figure 2] FIG. 2 is a perspective view illustrating a stator of the motor-operated valve according to the embodiment. [Figure 3] 3 is a cross-sectional view taken along line 3-3 in FIG. 1, illustrating the pole teeth of the stator of the motor-operated valve according to the present embodiment. FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view illustrating a portion A in FIG. 3. [Figure 5] 2 is a front view illustrating the pole teeth of the stator of the motor-operated valve according to the embodiment, showing the opposing surfaces of the pole teeth from the front. FIG. [Figure 6] 4 is an enlarged cross-sectional view illustrating a pole tooth of a stator of a motor-operated valve according to a comparative example, taken at a position corresponding to part A in FIG. 3 of the present embodiment. [Figure 7]4 is an enlarged cross-sectional view illustrating a pole tooth of a stator of a motor-operated valve according to a modified example, taken at a position corresponding to part A in FIG. 3 of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] This embodiment will be described below. In the following description of the drawings, identical or similar parts are designated by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device or component, etc. may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, there may be parts with different dimensional relationships and ratios between the drawings. Furthermore, unless otherwise specified in the specification, the number of each component element of the present disclosure is not limited to one, and multiple elements may be present.

[0019] <Motor-operated valve configuration> Hereinafter, a motor-operated valve 1 according to this embodiment of the present disclosure will be described with reference to Figures 1 to 7. The motor-operated valve 1 according to this embodiment is used, for example, in an automotive air conditioner to control the flow rate of a fluid. The fluid is, for example, a high-pressure refrigerant.

[0020] As shown in Figure 1, the electric valve 1 of this embodiment has a valve body 10, a valve element 20, a rotor case 30, a bearing 35, a rotor 40, a drive shaft 50, and a can 60 as an inner case.

[0021] (Valve body) The valve body 10 has a body member 11, a sleeve 18, and a valve element support plate 19. The body member 11 is cylindrical. The body member 11 is made of a metal such as an aluminum alloy. The outer shape of the cross section of the upper part 11A of the body member 11 in FIG. 1 is hexagonal. The "cross section" is a cross section perpendicular to the central axis L. The body member 11 has a valve chamber 12, a valve port 13, a valve seat 14, a first connecting passage 15, a second connecting passage 16, and a mounting hole 17.

[0022] The valve port 13 is connected to the valve chest 12. The valve port 13 is surrounded by a valve seat 14 in the valve chest 12. The first connecting passage 15 has a cross shape extending from the valve chest 12 in the left-right direction in Figure 1 and in the front-to-back direction perpendicular to the plane of the paper in Figure 1. The second connecting passage 16 extends from the valve port 13 downward in Figure 1.

[0023] The mounting hole 17 is located so as to open to the upper surface 11C of the main body member 11 in FIG. 1. The mounting hole 17 is connected to the valve chamber 12. The main body member 11 has a retaining surface 17A, which is an annular flat surface facing upward in FIG. 1. The retaining surface 17A is located at the connection point between the mounting hole 17 and the valve chamber 12. The main body member 11 has a male thread 11S and a female thread 11T. The male thread 11S is located on the outer peripheral surface of the lower portion 11B of the main body member 11 in FIG. 1. The female thread 11T is located on the inner peripheral surface of the mounting hole 17. The main body member 11 also has annular grooves 11D and 11E. The upper annular groove 11D in FIG. 1 is located above the male thread 11S on the outer peripheral surface of the lower portion 11B of the main body member 11. The lower annular groove 11E in FIG. 1 is located below the first connecting passage 15 on the outer peripheral surface of the lower portion 11B of the main body member 11. O-rings (not shown) are disposed in the annular grooves 11D and 11E.

[0024] The sleeve 18 is made of synthetic resin or metal and has a cylindrical shape as a whole. The sleeve 18 integrally includes a small diameter portion 18A, a large diameter portion 18B, and a flange portion 18C.

[0025] The small diameter portion 18A and the large diameter portion 18B have a cylindrical shape. The inner diameter of the large diameter portion 18B is larger than the outer diameter of the small diameter portion 18A. The lower end of the large diameter portion 18B in FIG. 1 is coaxially connected to the upper end of the small diameter portion 18A. The flange portion 18C has an annular plate shape. The inner peripheral edge of the flange portion 18C is connected to the upper end of the large diameter portion 18B. The small diameter portion 18A and the large diameter portion 18B are arranged in the valve chamber 12. The flange portion 18C is in contact with the retaining surface 17A of the main body member 11.

[0026] The valve disc support plate 19 is made of synthetic resin or metal. The valve disc support plate 19 has an annular disc shape. The outer peripheral edge of the valve disc support plate 19 is circular and the inner peripheral edge is square. The valve disc support plate 19 is disposed in the mounting hole 17. The lower surface of the valve disc support plate 19 in FIG. 1 is in contact with the flange portion 18C of the sleeve 18.

[0027] (Valve body) The valve element 20 is made of synthetic resin or metal. The valve element 20 integrally includes a shaft portion 21 and a valve portion 22. The valve element 20 moves in response to the rotation of the rotor 40.

[0028] The shaft portion 21 has an overall columnar shape. The upper portion 21A of the shaft portion 21 in FIG. 1 has a rectangular columnar shape. The outer shape of the cross section of the upper portion 21A in FIG. 1 is the same square as the inner peripheral edge of the valve body support plate 19. The lower portion 21B of the shaft portion 21 in FIG. 1 has a cylindrical shape. The outer diameter of the lower portion 21B in FIG. 1 is the same as the inner diameter of the small diameter portion 18A of the sleeve 18. The shaft portion 21 has a threaded hole 21C and a female thread 21T. The threaded hole 21C is located on the upper end surface of the shaft portion 21. The female thread 21T is located on the inner peripheral surface of the threaded hole 21C.

[0029] An upper portion 21A of the shaft portion 21 in FIG. 1 is disposed inside the valve element support plate 19. A lower portion 21B of the shaft portion 21 in FIG. 1 is disposed inside the small diameter portion 18A of the sleeve 18. The valve element 20 is supported by the sleeve 18 and the valve element support plate 19 so as to be movable in the vertical direction, i.e., along the direction of the central axis L. Rotation of the valve element 20 around the central axis L is prevented by the valve element support plate 19. The shape of the upper portion 21A of the shaft portion 21 in FIG. 1 and the shape of the inner peripheral edge of the valve element support plate 19 may be any shape as long as they prevent rotation of the valve element 20 around the central axis L.

[0030] The valve portion 22 has a truncated cone shape whose diameter decreases from the top to the bottom in Fig. 1. The valve portion 22 is coaxially connected to the lower end of the shaft portion 21. The valve portion 22 is disposed in the valve chamber 12 and the valve port 13. The valve portion 22 faces the valve port 13 and the valve seat 14 in the up-down direction in Fig. 1. When the valve portion 22 comes into contact with the valve seat 14, the valve port 13 closes. When the valve portion 22 moves away from the valve seat 14, the valve port 13 opens, and as a result, a throttled flow path is formed between the valve portion 22 and the valve port 13.

[0031] (Rotor case) The rotor case 30 is made of a metal such as non-magnetic stainless steel. In this specification, "non-magnetic" refers to the property of a material not being magnetized even when placed in a magnetic field. "Non-magnetic" also includes the property of not being substantially magnetized. The rotor case 30 may be made of a synthetic resin. The rotor case 30 is cylindrical overall. The rotor case 30 integrally includes a first portion 31, a second portion 32, and a connecting portion 33.

[0032] The first portion 31 has a cylindrical shape. The first portion 31 has a male thread 31S. The male thread 31S is located on the lower portion of the outer circumferential surface of the first portion 31 in FIG. 1. The first portion 31 is located in the mounting hole 17 of the main body member 11, and the male thread 31S of the first portion 31 is threadedly engaged with the female thread 11T of the main body member 11. The first portion 31 is attached to the main body member 11 using a threaded structure. An O-ring 39 seals the space between the main body member 11 and the first portion 31 in the mounting hole 17. The flange portion 18C of the sleeve 18 and the valve body support plate 19 are held between the lower end of the first portion 31 in FIG. 1 and the holding surface 17A of the main body member 11. The first portion 31 has a bearing mounting surface 31A, which is an annular flat surface facing upward in FIG. 1. The bearing mounting surface 31A is located on the inner circumferential surface of the first portion 31.

[0033] The second portion 32 has a cylindrical shape. The inner diameter of the second portion 32 is larger than the outer diameter of the first portion 31. The connecting portion 33 has a circular flat plate shape. The inner peripheral edge of the connecting portion 33 in FIG. 1 is connected to the upper end of the first portion 31. The outer peripheral edge of the connecting portion 33 is connected to the lower end of the second portion 32.

[0034] The bearing 35 is, for example, a radial ball bearing. The bearing 35 is disposed inside the first portion 31. The lower end of the outer ring of the bearing 35 in FIG. 1 is in contact with the bearing installation surface 31A. The bearing 35 may also be a thrust ball bearing.

[0035] (rotor) The rotor 40 is cylindrical overall. The rotor 40 is disposed inside the second portion 32 of the rotor case 30. The rotor 40 integrally includes a cylindrical portion 41, a disk portion 42, and a connecting portion 43.

[0036] The cylindrical portion 41 has a plurality of north poles and a plurality of south poles. The plurality of north poles and the plurality of south poles are alternately arranged at equal angular intervals in the circumferential direction on the inner peripheral surface of the cylindrical portion 41. The plurality of north poles and the plurality of south poles extend in the vertical direction in FIG. 1. The disc portion 42 is connected to the lower end of the cylindrical portion 41 in FIG. 1. The connecting portion 43 has a cylindrical shape. The connecting portion 43 is arranged coaxially in the center of the disc portion 42 in the vertical direction in FIG. 1. The rotor 40 is a magnet rotor.

[0037] (drive shaft) The drive shaft 50 is made of synthetic resin or metal. The drive shaft 50 has an overall cylindrical shape. The drive shaft 50 has a male thread 51S. The male thread 51S is disposed on the outer peripheral surface of the lower portion of the drive shaft 50 in FIG. 1. The male thread 51S is threadedly engaged with the female thread 21T of the valve element 20. Alternatively, the drive shaft 50 may have a female thread and the valve element 20 may have a male thread. The female thread 21T and the male thread 51S form a feed screw mechanism that moves the valve element 20 in FIG. 1 in the vertical direction. The center of the drive shaft 50 is rotatably supported by the bearing 35. The drive shaft 50 has a support surface 50A, which is an annular flat surface facing downward in FIG. 1. The upper end of the inner ring of the bearing 35 is in contact with the support surface 50A. The upper portion of the drive shaft 50 in FIG. 1 is fitted into the connecting portion 43. The drive shaft 50 rotates together with the rotor 40.

[0038] (Can) The can 60 is cylindrical overall. The can 60 is made of, for example, a non-magnetic metal such as stainless steel. The can 60 may also be made of a synthetic resin. The can 60 integrally includes a peripheral wall portion 61, a bottom wall portion 62, and an annular portion 63.

[0039] The bottom wall portion 62 has a disk shape. The outer peripheral edge of the bottom wall portion 62 is connected to the lower end of the peripheral wall portion 61 in FIG. 1. The annular portion 63 has a circular plate shape. The inner peripheral edge of the annular portion 63 is connected to the upper end of the peripheral wall portion 61 in FIG. 1. The outer peripheral edge of the annular portion 63 is joined to the upper end of the second portion 32 of the rotor case 30 around the entire circumference in FIG. 1. The peripheral wall portion 61 and the bottom wall portion 62 are arranged inside the rotor 40. The second portion 32 of the rotor case 30 and the can 60 form a rotor space 65. The rotor 40 is arranged in the rotor space 65. The rotor space 65 is sealed from the outside of the motor-operated valve 1. The rotor space 65 is connected to the valve chamber 12 through a gap. Fluid from the valve chamber 12 is introduced into the rotor space 65.

[0040] The motor-operated valve 1 includes a housing 80, a stator 90, a control device 100, and a magnetic sensor (not shown). The housing 80, the stator 90, the control device 100, and the magnetic sensor constitute a stator unit.

[0041] The housing 80 is made of synthetic resin. The housing 80 has a housing main body 81 and a lid 85. The housing main body 81 integrally has a peripheral wall portion 82, a bottom wall portion 83, and a support portion 84. The peripheral wall portion 82 has a cylindrical shape. The bottom wall portion 83 has a disk shape. The bottom wall portion 83 is connected to the lower end of the peripheral wall portion 82 in FIG. 1. An O-ring 89 seals the gap between the bottom wall portion 83 and the annular portion 63 of the can 60.

[0042] The lid body 85 integrally includes a lid portion 86 and a connector portion 87. The lid portion 86 has a disk shape. The outer peripheral edge of the lid portion 86 is joined to the upper end of the peripheral wall portion 82. The connector portion 87 has an elongated cylindrical shape. The connector portion 87 extends upward from the center of the upper surface of the lid portion 86 in FIG. 1. The peripheral wall portion 82, the bottom wall portion 83, and the lid portion 86 form a control device space 88.

[0043] (Control device) The control device 100 is disposed in the control device space 88. The control device 100 has a substrate 101, a terminal component 102, and a computer (not shown). The substrate 101 is a printed circuit board, and electronic components including a computer are mounted on it. A plurality of coil terminals 94 of the stator 90 are connected to the substrate 101. The terminal component 102 has a plurality of connector terminals 103. One end of each of the plurality of connector terminals 103 is connected to the substrate 101, and the other end is disposed inside the connector portion 87. The computer controls the motor-operated valve 1.

[0044] The magnetic sensor (not shown) is a sensor having a Hall element that outputs a digital signal according to the direction of the magnetic field. The magnetic sensor is disposed in the lower part of the housing 80 in FIG. 1. The magnetic sensor faces the magnetic poles (i.e., the north pole and south pole) of the rotor 40 in the radial direction via the peripheral wall part 61 of the can 60. The magnetic sensor detects the magnetism of the rotor 40. The magnetic sensor is electrically connected to the substrate 101. Based on the signal output from the magnetic sensor, the computer detects the rotational position of the rotor 40.

[0045] In the motor-operated valve 1, the central axes of the main body member 11, sleeve 18, valve element support plate 19, valve element 20, rotor case 30, bearing 35, rotor 40, drive shaft 50, can 60, housing main body 81, lid body 85, and stator 90 all coincide with the central axis L. The main body member 11 has a valve chamber 12, a valve port 13, a valve seat 14, and a mounting hole 17. The lid body 85 has a lid portion 86 and a connector portion 87.

[0046] (stepping motor) The rotor 40 and the stator 90 constitute a stepping motor 98. The rotor 40 is disposed outside the peripheral wall portion 61 of the can 60. The stator 90 is fitted inside the peripheral wall portion 61 of the can 60. In the motor-operated valve 1 of this embodiment, the two stators 90 are stacked in the vertical direction in FIG. 1. The upper stator 90 in FIG. 1 is the A-phase stator, and the lower stator 90 in FIG. 1 is the B-phase stator. Note that in the present disclosure, the number of stators is arbitrary.

[0047] (stator) 1, the stator 90 has a pair of yokes 95, a plurality of claw-pole type pole teeth 96 provided on each yoke 95, a bobbin 92, a coil 93, and a coil terminal 94. The stator 90 is disposed inside the can 60. In other words, the motor-operated valve 1 according to this embodiment is an inner motor type.

[0048] As shown in FIGS. 2 and 3 , the yoke 95 is disk-shaped. A through-hole 95A is formed in the center of the yoke 95. A central axis L passes through the through-hole 95A. The plurality of pole teeth 96 extend from the outer periphery of the yoke 95 in the up-down direction parallel to the central axis L. In this embodiment, the yoke 95 and the plurality of pole teeth 96 are integrally formed as a single cylindrical member that is open on one side in the axial direction, for example, by press working a metal plate. The yoke 95 corresponds to the bottom of the cylindrical member, and the plurality of pole teeth 96 correspond to the side wall of the cylindrical member. In the present disclosure, the single cylindrical member may be formed by joining a yoke and a plurality of pole teeth that are separate members.

[0049] As shown in FIG. 2, the pole teeth 96 are plate-shaped and have flat opposing surfaces 96A. The multiple pole teeth 96 are arranged at approximately equal intervals in the circumferential direction of the yoke 95. The width of the pole teeth 96 along the circumferential direction gradually narrows from the base portion on the yoke 95 side to the tip on the opposite side from the base portion. In other words, all of the multiple pole teeth 96 are triangular plate-shaped members. Therefore, the width along the circumferential direction of the gap between adjacent pole teeth 96 in the circumferential direction gradually widens from the base portion on the yoke 95 side to the tip on the opposite side from the base portion.

[0050] A pair of yokes 95 constituting one stator 90 are arranged with a gap between them, with the pole teeth 96 of one yoke 95 positioned in the gap between the pole teeth 96 of the other yoke 95. One pole tooth 96 is arranged in one gap. In one stator 90, the pole teeth 96 of the two yokes 95 are meshed with each other. That is, a pair of cylindrical members are arranged facing each other so as to cover the opening of the other member. A bobbin 92 and a coil 93 are housed in the internal space surrounded by the two yokes 95 and their respective pole teeth 96.

[0051] The bobbin 92 is made of synthetic resin. The plurality of coil terminals 94 extend upward from the bobbin 92 in FIG.

[0052] (protrusion) Next, the protrusions of the stator 90 according to this embodiment will be described in detail. As shown in Fig. 2, in this embodiment, all of the plurality of pole teeth 96 are provided with protrusions 97 that partially protrude from the opposing surfaces 96A toward the inner wall surface 60A of the can 60 beyond the surrounding area. In this disclosure, it is not essential that all of the plurality of pole teeth are provided with protrusions, and it is sufficient that one or more pole teeth are provided with protrusions.

[0053] As shown in FIG. 3, the protrusion 97 protrudes toward the can 60 located radially outward. FIG. 4 illustrates an opposing surface 96A of the pole tooth 96 that faces the inner wall surface 60A of the can 60, and a curved surface 97A that is the portion of the protrusion 97 that faces the inner wall surface 60A of the can 60. In this embodiment, the curved surface 97A is curved overall without being sharp. In this disclosure, the surface of the curved portion may be partially curved. Also, in this disclosure, the curved portion is not required.

[0054] In this embodiment, the protrusion 97 is in contact with the inner wall surface 60A of the can 60. In this disclosure, it is not necessary for the protrusion to be in contact with the inner wall surface of the can, and the protrusion may be separated from the inner wall surface of the can. Also, in this disclosure, all of the protrusions may be separated from the inner wall surface of the can, or only some of the protrusions may be separated from the inner wall surface of the can.

[0055] The protrusions 97 can be formed on the opposing surfaces 96A of the pole teeth 96 by, for example, press working. As shown in Fig. 4, recesses 96B formed by press working the protrusions 97 are shown on the surface of the pole teeth 96 opposite the opposing surfaces 96A in the radial direction. Press working makes it easy to manufacture the protrusions 97. In the present disclosure, the method for manufacturing the protrusions is not limited to press working.

[0056] 5, in this embodiment, when the opposing surface 96A is viewed from the front toward the central axis L, the pole teeth 96 are generally symmetrical with respect to the center line LC of the pole teeth 96. The center line LC of the pole teeth 96 is parallel to the central axis L of the motor-operated valve 1. In the present disclosure, it is not essential that the pole teeth are generally symmetrical with respect to LC, and they may be asymmetrical.

[0057] In this embodiment, the protrusion 97 has a long, narrow dome shape extending in the vertical direction in FIG. 5 , but in this disclosure, the shape of the protrusion is not limited to this. In this disclosure, the shape of the protrusion may be a hemispherical dome shape, or may be other shapes such as a pyramid shape or a rod shape. Also, in this embodiment, the case where one protrusion 97 is formed on one pole tooth 96 has been exemplified, but in this disclosure, the number of protrusions formed on one pole tooth may be multiple.

[0058] (Comparative Example) 6, in the case of a stator 90Z according to a comparative example that does not have a protrusion 97, a gap is formed in the circumferential center between the curved inner wall surface 60A of the can 60 and the opposing surface 96A of the flat, plate-shaped pole tooth 96 that faces the inner wall surface 60A. The motor-operated valve according to the comparative example is similar in configuration to the motor-operated valve 1 according to this embodiment, except that it does not have a protrusion 97. In the comparative example, the torque loss of the motor due to the gap is greater than in this embodiment that has a protrusion 97.

[0059] <Operation of the motor-operated valve> In the motor-operated valve 1 according to this embodiment, the rotor 40 can be rotated in one circumferential direction by supplying current to the multiple coils 93 of the stator 90. The drive shaft 50 rotates together with the rotor 40. Due to the feed screw action between the male thread 51S of the drive shaft 50 and the female thread 21T of the valve element 20, the valve element 20 moves downward in FIG. 1, reducing the opening area of ​​the valve orifice 13, i.e., the throttle flow path. When the valve orifice 13 is closed by the valve element 20 coming into contact with the valve seat 14, the motor-operated valve 1 is brought into a fully closed state.

[0060] Furthermore, by supplying current to the multiple coils 93 of the stator 90 in the opposite direction to that used when the motor-operated valve 1 is in the fully closed state, the rotor 40 can be rotated in the opposite direction. The drive shaft 50 rotates together with the rotor 40. Due to the feed screw action between the male thread 51S of the drive shaft 50 and the female thread 21T of the valve disc 20, the valve disc 20 moves upward in FIG. 1, increasing the opening area of ​​the valve orifice 13. When the valve disc 20 is furthest from the valve orifice 13, the motor-operated valve 1 is in the fully open state. When the motor-operated valve 1 is in the fully open state, the opening area of ​​the valve orifice 13 is at its largest.

[0061] (Action and effect) In this embodiment, all of the pole teeth 96 of the stator 90 arranged inside the can 60 are provided with protrusions 97 that partially protrude from the opposing surfaces 96A toward the inner wall surface 60A of the can 60 beyond the surrounding area. Therefore, even if the stator 90 is arranged inside the can 60, the protrusions 97 can reduce the width of the gap between the stator 90 and the can 60 compared to, for example, a pole tooth 96 whose opposing surface 96A is entirely flat. As a result, torque loss can be suppressed while the device is made more compact.

[0062] In this embodiment, the curved surface 97A of the protrusion 97 facing the inner wall surface 60A of the can 60 is curved. Therefore, even if the protrusion 97 comes into contact with the inner wall surface 60A of the can 60, the can 60 or the pole teeth 96 are unlikely to be damaged.

[0063] Furthermore, in this embodiment, the protrusion 97 is in contact with the inner wall surface 60A of the can 60. Therefore, the torque loss is more effectively suppressed than when a gap is formed between the stator 90 and the can 60 without the protrusion 97 being formed.

[0064] Furthermore, in this embodiment, when the opposing surface 96A is viewed from the front toward the central axis L, the pole teeth 96 are symmetrical with respect to the center line LC parallel to the central axis L. Therefore, compared to, for example, a case where the pole teeth 96 are asymmetrical with respect to the center line LC parallel to the central axis L, the torque loss suppression effect is higher.

[0065] (Variation) In the present embodiment, the case where the corners at both ends in the circumferential direction of the pole teeth 96 contact the inner wall surface 60A of the can 60 has been exemplified, but in the present disclosure, as shown in Fig. 7, each of the corners at both ends in the circumferential direction of the pole teeth 96 may be spaced apart from the inner wall surface 60A of the can 60. Specifically, in the motor-operated valve according to the modified example, the shape and dimensions of the pole teeth 96, including the shape and dimensions of the protrusions 97, are set in advance so that a gap G is formed between each of the corners at both ends in the circumferential direction of the pole teeth 96 and the inner wall surface 60A of the can 60. The configurations of the other members of the motor-operated valve according to the modified example, except for the pole teeth 96, are the same as the members of the motor-operated valve 1 according to the present embodiment, and therefore redundant description will be omitted.

[0066] (Effects of Modified Examples) In the motor-operated valve according to the modified example, similarly to the present embodiment, even if the stator 90 is disposed inside the can 60, the protrusion 97 can reduce the width of the gap between the stator 90 and the can 60 compared to, for example, the case of a pole tooth 96 whose opposing surface 96A is entirely flat. As a result, torque loss can be suppressed while the device is made more compact.

[0067] Furthermore, in this modification, when the stator 90 is inserted inside the can 60 during assembly of the motor-operated valve, the corners at both ends in the circumferential direction of the pole teeth 96 are spaced apart from the inner wall surface 60A of the can 60, thereby suppressing damage to the inner wall surface 60A that would otherwise be caused by contact with the corners. The effect of suppressing damage to the inner wall surface 60A can be obtained not only during assembly, but also when the can 60 is deformed due to the influence of the internal pressure of the fluid during operation of the motor-operated valve, for example. Other effects of the modification are the same as those of this embodiment.

[0068] Although the present disclosure has been described based on the above disclosed embodiments, the descriptions and drawings that form part of this disclosure should not be understood to limit the present disclosure. For example, the present disclosure can be configured by partially combining the configurations illustrated in the attached drawings. The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specific matters in the scope of the claims that are appropriate from the above description. [Explanation of symbols]

[0069] 1...Motor-operated valve, 10... valve body, 11... body member, 11A... upper part, 11B... lower part, 11C... upper surface, 11D... Annular groove, 11E... Annular groove, 11S... Male thread, 11T... Female thread, 12... valve chamber, 13... valve port, 14... valve seat, 15... connecting passage, 16... connecting passage, 17...mounting hole, 17A...holding surface, 18...sleeve, 18A...small diameter portion, 18B...large diameter portion, 18C...flange portion, 19...valve body support plate, 20... valve body, 21... shaft portion, 21A... upper portion, 21B... lower portion, 21C... screw hole, 21T... Female thread, 22... Valve section, 30... rotor case, 31... first part, 31A... bearing installation surface, 32... second part, 33... connecting part, 35... bearing, 39... O-ring, 40... rotor, 41... cylindrical portion, 42... disk portion, 43... connecting portion 50...Drive shaft, 50A...Support surface, 51S...Male thread, 60... can, 60A... inner wall surface, 61... peripheral wall portion, 62... bottom wall portion, 63... annular portion, 65...Rotor space, 80...housing, 81...housing body, 82...peripheral wall portion, 83...bottom wall portion, 85...lid body, 86...lid portion, 87...connector portion, 88...control device space, 89...O-ring, 90, 90Z... Stator, 92... Bobbin, 93... Coil, 94... Coil terminal, 95...yoke, 95A...through hole, 96...pole tooth, 96A...opposing surface, 96B...recess 97...protrusion, 97A...curved surface, 98...stepping motor, 100...control device, 101...board, 102...terminal component, 103...connector terminal, L...center axis, LC...center line of pole tooth, G...gap

Claims

1. A cylindrical can and a cylindrical rotor disposed outside the can; a valve body that moves in response to rotation of the rotor; a stator disposed inside the can, the stator having a plurality of plate-shaped pole teeth each having a flat opposing surface facing the inner wall surface of the can, and one or more of the pole teeth each having a protruding portion that partially protrudes from the opposing surface toward the inner wall surface of the can beyond its surroundings; An electric valve comprising:

2. A portion of the protrusion facing the inner wall surface of the can is curved. The motor-operated valve according to claim 1 .

3. the protrusion is in contact with the inner wall surface of the can; The motor-operated valve according to claim 1 or 2.

4. When the opposing surfaces are viewed from the front toward the central axis, the pole teeth are symmetrical with respect to a center line parallel to the central axis. The motor-operated valve according to claim 1 or 2.

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