Electric valve

Abstract

Provided is an electric valve capable of reliably detecting the magnetic force of a magnetic rotor by means of a magnetic sensor mounted on a substrate. The electric valve (1) comprises magnetic transmission components (36a) and (36b) arranged between a housing (30) and magnetic sensors (35a) and (35b) mounted on a substrate (85). On an outer peripheral surface (41a) of a magnetic rotor (41) arranged on the inner side of the housing (30), a plurality of N poles and a plurality of S poles extending in the direction of the rotation axis of the magnetic rotor (41) are arranged in an alternating manner in the circumferential direction. Furthermore, the housing side end portions (36a1) and (36b1) of the magnetic transmission components (35a) and (35b) are arranged to be radially opposite to the magnetic rotor (41) via the housing (30).

Description

Technical Field

[0001] The present invention relates to an electric valve, and more particularly to an electric valve having a magnetic rotor disposed inside a housing. Background Art

[0002] Patent Documents 1 and 2 describe an example of a conventional electric valve. The electric valve of Patent Document 1 includes a magnetic rotor for driving a valve core and a permanent magnet that rotates together with the magnetic rotor. The magnetic rotor and the permanent magnet are arranged inside a housing. A magnetic sensor is provided on a substrate arranged above the housing. The electric valve detects the magnetic force of the permanent magnet through the magnetic sensor, thereby obtaining the rotation angle of the magnetic rotor.

[0003] The electric valve of Patent Document 2 has a magnetic rotor for driving a valve core, a magnetic drum fixed to a rotating shaft of the magnetic rotor, and a magnet provided at the upper end of the rotating shaft. The magnetic rotor, the magnetic drum, and the magnet are arranged on the inner side of a housing. A magnetic sensor for detecting a rotation angle and a magnetic sensor for detecting an upper and lower position are arranged on the outer side of the housing. The electric valve detects the magnetic force of the magnetic drum and the magnet by the magnetic sensor for detecting a rotation angle and the magnetic sensor for detecting an upper and lower position, thereby calculating the valve opening.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-179133

[0007] Patent Document 2: Japanese Patent Application Publication No. 2001-12633

[0008] Technical problem to be solved by the invention

[0009] The above-mentioned electric valve has a permanent magnet and a magnetic drum which are different parts from the magnetic rotor. Therefore, the above-mentioned electric valve has a technical problem that the number of parts increases and the structure becomes complicated, thereby increasing the manufacturing cost. In order to suppress the increase in the number of parts, for example, the electric valve of Patent Document 1 can have a structure that detects the magnetic force of the magnetic rotor by a magnetic sensor on a substrate. However, in this structure, the substrate and the magnetic rotor are far apart. Therefore, the magnetic force of the magnetic rotor cannot be correctly detected by the magnetic sensor on the substrate. Summary of the invention

[0010] Therefore, an object of the present invention is to provide an electric valve capable of reliably detecting the magnetic force of a magnetic rotor by a magnetic sensor mounted on a substrate.

[0011] Technical means for solving technical problems

[0012] In order to achieve the above-mentioned purpose, the electric valve of the present invention comprises: a valve body; a cylindrical shell installed on the valve body; a cylindrical magnetic rotor arranged on the inner side of the shell; a valve core, which is driven to open and close the port in the valve body by the rotation of the magnetic rotor; a stator, which is arranged on the outer side of the shell; and a substrate, on which a magnetic sensor is installed. The electric valve has a magnetic transfer component arranged between the shell and the magnetic sensor, and on the outer peripheral surface of the magnetic rotor, one or more N poles and S poles extending in the direction of the rotation axis of the magnetic rotor are arranged alternately in the circumferential direction, and the end of the shell side of the magnetic transfer component is arranged to be radially opposite to the magnetic rotor across the shell.

[0013] According to the present invention, there is a magnetic transfer component arranged between a housing and a magnetic sensor mounted on a substrate. A magnetic rotor is arranged on the inner side of the housing. On the outer peripheral surface of the magnetic rotor, one or more N poles and S poles extending in the direction of the rotation axis of the magnetic rotor are arranged in a manner alternately arranged in the circumferential direction. In addition, the end of the housing side in the magnetic transfer component is arranged to be radially opposite to the magnetic rotor via the housing. The magnetic flux generated by the magnetic poles (N pole, S pole) of the magnetic rotor is easily transmitted in the radial direction. Therefore, by arranging the end of the housing side in the magnetic transfer component in a manner close to the magnetic rotor in the radial direction, the magnetic flux can be effectively transmitted to the magnetic transfer component. Therefore, in the present invention, a large amount of magnetic flux is transmitted to the magnetic sensor via the magnetic transfer component, so that the magnetic flux of the magnetic rotor can be reliably detected.

[0014] In the present invention, the stator is preferably provided with a magnetic transmission member support portion that supports the end portion of the magnetic transmission member on the housing side. Thus, the end portion of the magnetic transmission member on the housing side can be appropriately positioned relative to the stator.

[0015] In the present invention, it is preferred that the stator has a plurality of pole teeth, and when viewed from the rotation axis direction, the end of the magnetic transmission member on the housing side is arranged on a straight line passing through the rotation axis of the magnetic rotor and the center (including the approximate center) of one of the plurality of pole teeth. In the structure in which the stator has a plurality of pole teeth, when the magnetic rotor stops rotating, it becomes any of the following states: (i) a state in which the pole teeth are directly opposite to the magnetic poles of the magnetic rotor; (ii) a state in which the pole teeth are directly opposite to the portion between adjacent magnetic poles on the outer peripheral surface of the magnetic rotor. In the state (i) above, at the position of the pole teeth viewed from the rotation axis direction, the radial component included in the magnetic flux from the N pole to the S pole is the largest, and the magnetic flux transmitted to the magnetic transmission member is the largest. In the state (ii) above, at the position of the pole teeth viewed from the rotation axis direction, the radial component included in the magnetic flux from the N pole to the S pole is the smallest, and the magnetic flux transmitted to the magnetic transmission member is the smallest. Therefore, the state (i) above and the state (ii) above can be clearly distinguished, and the stop position of the magnetic rotor can be obtained with high accuracy. In addition, the rotation direction of the magnetic rotor can be obtained based on the waveform of the detected magnetic flux.

[0016] In the present invention, it is preferred that the magnetic transmission component is formed into a long and narrow plate or rod shape, and a portion of the magnetic transmission component including the end portion on the housing side is arranged along the radial direction. Thus, since the magnetic flux is easily transmitted in the radial direction, the magnetic flux can be transmitted to a portion farther from the magnetic rotor through the magnetic transmission component.

[0017] In the present invention, it is preferable that the other portion of the magnetic transmission member including the end portion on the magnetic sensor side is arranged along a direction perpendicular to the magnetically sensitive surface of the magnetic sensor. Thereby, the magnetic flux can be appropriately detected in the magnetic sensor.

[0018] In the present invention, it is preferred that the magnetic rotor moves to one side in the direction of the rotation axis when the port is closed, and moves to the other side in the direction of the rotation axis when the port is opened, and the end of the magnetic transmission component on the housing side is arranged on the other side compared to the plurality of pole teeth of the stator, and is arranged to be radially opposite to the magnetic rotor via the housing when the port is closed. Thus, the magnetic rotor moving in the direction of the rotation axis and the end of the magnetic transmission component on the housing side are radially opposite from the closed valve state to the open valve state. Therefore, the magnetic flux of the magnetic rotor can be reliably detected in any state from the closed valve state to the open valve state, so that the rotation angle of the magnetic rotor can be obtained with high accuracy.

[0019] In the present invention, it is preferred that in any state from the state of closing the port to the state of fully opening the port, the position of the end of the magnetic transmission component on the housing side in the direction of the rotation axis is within the range of the full length of the magnetic rotor. Thus, in any state from the state of closing the port (valve closed state) to the state of fully opening the port (valve open state), the magnetic rotor and the end of the magnetic transmission component on the housing side are radially opposite. Therefore, the magnetic flux of the magnetic rotor can be reliably detected, and the rotation angle of the magnetic rotor can be obtained with high accuracy.

[0020] In the present invention, it is preferred that in any state from the state of closing the port to the state of fully opening the port, the position of the stator in the direction of the rotation axis is within the full length of the magnetic rotor. Thus, in any state from the valve closing state to the valve opening state, the magnetic force of the stator can effectively act on the magnetic rotor, thereby enabling the magnetic rotor to rotate effectively.

[0021] In the present invention, it is preferable that the mounting surface of the magnetic sensor in the substrate is arranged to face the housing in the radial direction. Thus, since the magnetic flux is easily transmitted in the radial direction, the magnetic flux can be effectively transmitted to the magnetic sensor via the magnetic transmission member.

[0022] In the present invention, it is preferred that the electric valve further comprises: a housing that accommodates the shell and the stator; a box that accommodates the substrate; and a magnetic transfer unit, the magnetic transfer unit having the magnetic transfer component and a support body that supports the magnetic transfer component, the shell opening provided in the shell is connected to the box opening provided in the box, and the peripheral edge of the shell opening in the shell is engaged with the peripheral edge of the box opening in the box, the magnetic transfer component of the magnetic transfer unit is inserted through the box opening and the shell opening, and the support body is installed in the box. Thus, the magnetic transfer component can be easily arranged near the shell by inserting the magnetic transfer component through the box opening and the shell opening. In addition, since the peripheral edge of the shell opening in the shell is engaged with the peripheral edge of the box opening in the box, airtightness can be ensured.

[0023] Effects of the Invention

[0024] According to the present invention, the magnetic force of the magnetic rotor can be reliably detected by the magnetic sensor mounted on the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a front view of an electric valve according to an embodiment of the present invention.

[0026] Figure 2 Yes means Figure 1 A longitudinal sectional view of the electric valve in the closed state.

[0027] Figure 3 Yes means Figure 1 A longitudinal sectional view of the electric valve in the open state.

[0028] Figure 4 It is along Figure 2 A cross-sectional view along the line X1-X1.

[0029] Figure 5 Yes Description Figure 1 Diagram of the magnetic rotor and stator of an electric valve.

[0030] Figure 6 yes Figure 1 A three-dimensional view of the stator of an electric valve.

[0031] Figure 7 yes Figure 1 A longitudinal sectional view of a stator of an electric valve.

[0032] Figure 8 yes Figure 1 A three-dimensional view of the housing of the electric valve.

[0033] Fig. 9 yes Figure 1 A perspective view of a box of an electric valve.

[0034] Fig.10 yes Figure 1 A stereoscopic view of the magnetic transfer unit of the electric valve.

[0035] Fig.11 Yes means Figure 1 A perspective view of the structure of a modified example of a stator of an electric valve.

[0036] Fig.12 This is a perspective view schematically showing a transmission mode of magnetic flux in a structure in which a single elongated plate-shaped magnetic transmission member is arranged to extend in the rotation axis direction of the magnetic rotor.

[0037] Fig.13 This is a perspective view schematically showing a manner of transmitting magnetic flux in a structure in which a single square plate-shaped magnetic transmission member is arranged to extend in the rotation axis direction and radial direction of the magnetic rotor.

[0038] Fig.14 This is a perspective view schematically showing a manner of transmitting magnetic flux in a structure in which a single elongated plate-shaped magnetic transmission member is arranged to extend in the radial direction of the magnetic rotor.

[0039] Fig.15 yes Fig.14 Top view of the structure.

[0040] Fig.16This is a perspective view schematically showing a transmission mode of magnetic flux in a structure in which two elongated plate-shaped magnetic transmission members are arranged to extend in the rotation axis direction of the magnetic rotor.

[0041] Fig.17 This is a perspective view schematically showing a manner of transmitting magnetic flux in a structure in which two square plate-shaped magnetic transmission members are arranged to extend in the rotation axis direction and radial direction of the magnetic rotor.

[0042] Fig.18 This is a perspective view schematically showing a manner of transmitting magnetic flux in a structure in which two elongated plate-shaped magnetic transmission members are arranged to extend in the radial direction of the magnetic rotor.

[0043] Fig.19 yes Fig.18 Top view of the structure.

[0044] Fig. 20 This is a perspective view schematically showing a manner of transmitting magnetic flux in a structure in which only a portion of the ends including the magnetic rotor side of two bent elongated plate-shaped magnetic transmission members is arranged to extend in the radial direction of the magnetic rotor.

[0045] Fig.21 yes Fig. 20 Top view of the structure. DETAILED DESCRIPTION

[0046] Below, refer to Figure 1 to Figure 21 An electric valve according to an embodiment of the present invention will be described. The electric valve according to this embodiment is used to adjust a refrigerant flow rate in a refrigeration cycle or the like, for example.

[0047] Figure 1 It is a front view of an electric valve according to an embodiment of the present invention. Figure 2 , Figure 3 It is along Figure 1 A sectional view (longitudinal sectional view) along the axis L of the electric valve. Figure 2 Indicates the closed state of the electric valve. Figure 3 Indicates the open state of the electric valve. Figure 4 It is along Figure 2 The sectional view of the X1-X1 line. Figure 4 In the description, the inner side of the shell is omitted. Figure 5 Yes Description Figure 1 Diagram of the magnetic rotor and stator of an electric valve. Figure 5 (a) is along Figure 2 The cross-sectional view of the X2-X2 line. Figure 5 In (a), only the housing, the magnetic rotor, and the yoke of the upper stator of the stator are shown. Figure 5 In (a), the position of the magnetic transmission component is indicated by a dotted line. Figure 5(b) is a three-dimensional diagram of the magnetic rotor. Figure 5 In (a) and (b), the magnetic poles (N pole and S pole) of the magnetic rotor are schematically shown. Figure 6 , Figure 7 yes Figure 1 A three-dimensional view and a longitudinal sectional view of a stator of an electric valve. Figure 8 to Figure 10 yes Figure 1 A three-dimensional diagram of the housing, box and magnetic transfer unit of the electric valve. Figure 8 In the invention, a stator is arranged inside a casing. Fig.11 Yes means Figure 1 A perspective view of the structure of a modified example of a stator of an electric valve. Figure 12 to Figure 21 It is a diagram schematically showing the manner in which magnetic flux is transmitted from the magnetic rotor to the magnetic transmission member.

[0048] like Figure 1 to Figure 4 As shown, the electric valve 1 includes a valve body 10 , a housing 30 , magnetic sensors 35 a , 35 b , magnetic transmission members 36 a , 36 b , a drive mechanism 40 , a valve element 50 , a stator 60 , a casing 70 , a case 80 , and a substrate 85 .

[0049] The valve body 10 is made of a metal material such as aluminum alloy. The valve body 10 includes a main body 11 and a cylindrical portion 12. The main body 11 is formed in a rectangular parallelepiped shape. The cylindrical portion 12 protrudes upward from the upper surface 11a of the main body 11. A valve chamber 13 is provided inside the main body 11. Figure 2 The flow path 17 extending to the left side and to Figure 2 The flow path 18 extends to the right side of the valve chamber 13. The flow path 17 is connected to the valve chamber 13. The flow path 18 is connected to the valve chamber 13 via a port 19 opened to the valve chamber 13.

[0050] An external thread portion 12b is provided on a portion of the outer circumferential surface of the cylindrical portion 12. An internal thread portion 11b opened on the upper surface 11a is provided on the main body 11. The main body 11 and the cylindrical portion 12 are integrally combined by screwing the external thread portion 12b and the internal thread portion 11b. The inner space of the cylindrical portion 12 is connected to the valve chamber 13.

[0051] The valve body 10 further includes a flange 20. The flange 20 is made of a metal material such as stainless steel. The flange 20 is formed in a circular ring plate shape. An inner peripheral edge 20a of the flange 20 is joined to the upper end of the cylindrical portion 12 by brazing or the like.

[0052] The housing 30 is made of a metal material such as stainless steel. The housing 30 is formed into a cylindrical shape with a closed upper end. The lower end of the housing 30 is joined to the outer peripheral edge 20b of the flange 20 by welding or the like. A drive mechanism 40 is arranged inside the housing 30.

[0053] The magnetic sensors 35a and 35b are composed of, for example, Hall ICs. The Hall ICs have Hall elements and output signals corresponding to the direction and magnitude of the magnetic flux density passing through the magnetically sensitive surface. The magnetic sensors 35a and 35b may also be composed of magnetic sensors of a type other than the Hall ICs. The rotation angle and rotation direction of the magnetic rotor 41 can be obtained based on the signals output by the magnetic sensors 35a and 35b. In the present embodiment, although the structure has two magnetic sensors 35a and 35b, it may also be a structure having only one magnetic sensor 35a, for example.

[0054] The magnetic sensors 35a and 35b are mounted on the mounting surface 85a of the substrate 85. The magnetic sensors 35a and 35b are arranged so that their magnetically sensitive surfaces are parallel to the mounting surface 85a.

[0055] The magnetic transmission members 36a and 36b are made of a metal material through which magnetic flux can pass easily, such as a yoke, etc. The magnetic transmission members 36a and 36b are formed into an elongated plate shape. The magnetic transmission members 36a and 36b may be formed into other shapes such as a rod shape or a rectangular plate shape.

[0056] The magnetic transfer component 36a is arranged between the shell 30 and the magnetic sensor 35a. The magnetic transfer component 36a is bent at an obtuse angle. The magnetic transfer component 36a has a linear first portion A1 including an end portion of the magnetic transfer component 36a on the shell 30 side (hereinafter referred to as "shell side end portion 36a1"). The magnetic transfer component 36a has a linear second portion A2 including an end portion of the magnetic transfer component 36a on the magnetic sensor 35a side (hereinafter referred to as "sensor side end portion 36a2"). The magnetic transfer component 36a has a structure in which the first portion A1 and the second portion A2 are connected.

[0057] The magnetic transmission component 36b is arranged between the shell 30 and the magnetic sensor 35b. The magnetic transmission component 36b is bent at an obtuse angle. The magnetic transmission component 36b has a straight first portion B1 including an end portion on the shell 30 side of the magnetic transmission component 36b (hereinafter referred to as the "shell side end portion 36b1"). The magnetic transmission component 36b has a straight second portion B2 including an end portion of the magnetic sensor 35b in the magnetic transmission component 36b (hereinafter referred to as the "sensor side end portion 36b2"). The magnetic transmission component 36b has a structure in which the first portion B1 and the second portion B2 are connected.

[0058] The magnetic transmission components 36a and 36b can be bent at an adjustable angle. The first portions A1 and B1 of the magnetic transmission components 36a and 36b can be arranged along the radial direction of the magnetic rotor 41. The second portions A2 and B2 of the magnetic transmission components 36a and 36b can be arranged along a direction orthogonal to the magnetic sensing surfaces of the magnetic sensors 35a and 35b. In addition, the magnetic transmission components 36a and 36b can also be flat without being bent.

[0059] The magnetic transmission members 36a and 36b are integrated with a beam 37 made of synthetic resin by insert molding. The beam 37 is a support body that supports the second portions A2 and B2. The magnetic transmission members 36a and 36b and the beam 37 constitute a magnetic transmission unit 38.

[0060] The drive mechanism 40 drives the valve body 50 in the up-down direction. The drive mechanism 40 includes a magnetic rotor 41 , a valve shaft holder 42 , a guide bushing 43 , and a valve shaft 44 .

[0061] The magnetic rotor 41 is formed in a substantially cylindrical shape. The outer diameter of the magnetic rotor 41 is slightly smaller than the inner diameter of the housing 30. A plurality of N poles and a plurality of S poles are provided on the outer peripheral surface 41a of the magnetic rotor 41. The plurality of N poles and the plurality of S poles extend in the direction of the axis L and are arranged alternately and at equal intervals in the circumferential direction. One N pole and one S pole may be provided. In the present embodiment, 12 N poles and 12 S poles are arranged alternately at intervals of 15 degrees. The magnetic rotor 41 is configured to be rotatable inside the housing 30. Figure 5 (a) and (b) are schematic diagrams showing the configuration of the N pole and the S pole of the magnetic rotor 41. Figure 5 In (a) and (b) of FIG. 1 , the shaded area schematically represents the N pole, and the dotted area schematically represents the S pole. The rotation axis of the magnetic rotor 41 coincides with the axis L.

[0062] The valve shaft holder 42 is formed into a cylindrical shape with a closed upper end. The support ring 45 is fixed to the upper end of the valve shaft holder 42 by caulking. The magnetic rotor 41 is integrally connected to the valve shaft holder 42 via the support ring 45. The inner peripheral surface of the valve shaft holder 42 is provided with an internal thread portion 42c.

[0063] The guide bushing 43 includes a large diameter cylindrical portion 43a and a small diameter cylindrical portion 43b. The outer diameter of the large diameter cylindrical portion 43a is larger than the outer diameter of the small diameter cylindrical portion 43b. The small diameter cylindrical portion 43b is coaxially connected to the upper end of the large diameter cylindrical portion 43a. An external threaded portion 43c is provided on the outer peripheral surface of the small diameter cylindrical portion 43b. The external threaded portion 43c is screwed into the internal threaded portion 42c of the valve shaft retainer 42. The large diameter cylindrical portion 43a is pressed into the inner side of the cylindrical portion 12 of the valve body 10. The guide bushing 43 is combined with the valve body 10.

[0064] The valve shaft 44 has a cylindrical trunk 44a and a cylindrical upper small diameter portion 44b. The diameter of the upper small diameter portion 44b is smaller than the diameter of the trunk 44a. The upper small diameter portion 44b is coaxially connected to the upper end of the trunk 44a. The upper small diameter portion 44b is arranged to pass through the valve shaft retainer 42. A push nut 46 is installed on the upper small diameter portion 44b to prevent it from falling off. The valve shaft 44 has a step portion between the trunk 44a and the upper small diameter portion 44b. A compression coil spring 47 is arranged between the step portion and the valve shaft retainer 42. The valve shaft 44 is pressed downward by the compression coil spring 47.

[0065] An upper stopper 48 is mounted on the valve shaft holder 42. A lower stopper 49 is mounted on the large diameter cylindrical portion 43a of the guide bush 43. When the valve shaft holder 42 rotates and reaches the lower limit position, the upper stopper 48 abuts against the lower stopper 49 to restrict further rotation of the valve shaft holder 42.

[0066] The valve element 50 is provided integrally with the lower end portion of the valve shaft 44. The valve element 50 is driven to move in the up-down direction by the driving mechanism 40. The valve element 50 opens and closes the port 19 opened in the valve chamber 13.

[0067] like Figure 6 , Figure 7 As shown, the stator 60 is formed in a substantially cylindrical shape. The stator 60 has a fitting hole 60b divided by an inner peripheral surface 60a. The inner diameter of the fitting hole 60b is substantially the same as the outer diameter of the housing 30. The fitting hole 60b of the stator 60 is fitted into the housing 30. The stator 60 is arranged outside the housing 30. The stator 60 has an upper stator 61, a lower stator 62, and a molded part 65 made of synthetic resin.

[0068] The upper stator 61 and the lower stator 62 are arranged to overlap each other. Figure 7 As shown, the upper stator 61 has a yoke 61a and a coil 61c wound around the yoke 61a via a coil frame 61b. The yoke 61a has a plurality of claw-pole type pole teeth 63. The plurality of pole teeth 63 are arranged at equal intervals in the circumferential direction. In the present embodiment, the yoke 61a has 24 pole teeth 63. The plurality of pole teeth 63 have downward pole teeth 63a with the top end (thinner end) facing downward and upward pole teeth 63b with the top end facing upward. The plurality of downward pole teeth 63a and the plurality of upward pole teeth 63b are arranged alternately in the circumferential direction.

[0069] The lower stator 62 has the same structure as the upper stator 61. The lower stator 62 has a yoke 62a, a coil frame 62b, a coil 62c, and a plurality of claw-pole type pole teeth 64 (a downward pole tooth 64a and an upward pole tooth 64b). The lower stator 62 is arranged to be offset in the circumferential direction by half the interval between the plurality of pole teeth 63 relative to the upper stator 61. In this embodiment, the interval between the plurality of pole teeth 63 and the interval between the plurality of pole teeth 64 are 15 degrees (360 degrees / 24), respectively, and the lower stator 62 is arranged to be offset in the circumferential direction by 7.5 degrees (15 degrees / 2) relative to the upper stator 61. The upper stator 61, the lower stator 62, and the magnetic rotor 41 constitute a stepping motor. In addition, although this embodiment describes a structure in which the stator 60 has claw-pole type pole teeth, a structure having other types of pole teeth may also be adopted.

[0070] The molded material 65 is filled in the upper stage stator 61 and the lower stage stator 62. The molded material 65, together with the plurality of pole teeth 63 and the plurality of pole teeth 64, constitute the inner peripheral surface 60a of the stator 60. The molded material 65 has an annular portion 66 and a terminal support portion 67.

[0071] The annular portion 66 is formed in an annular shape and has an inner diameter that is the same as the outer diameter of the housing 30 . The annular portion 66 is disposed on the upper surface of the upper stator 61 .

[0072] The terminal support portion 67 is arranged to extend from the upper stator 61 and the lower stator 62 to the side ( Figure 2 The terminal support portion 67 has a plurality of terminals 68 embedded therein. The plurality of terminals 68 are connected to the coil 61c of the upper stator 61 and the coil 62c of the lower stator 62. The plurality of terminals 68 protrude from the top end 67a of the terminal support portion 67 and are connected to the substrate 85.

[0073] This embodiment has a structure in which the shell side ends 36a1, 36b1 of the magnetic transmission components 36a, 36b are arranged on the upper surface 66c of the annular portion 66 and the sensor side ends 36a2, 36b2 are supported by the beam 37. The beam 37 supports only the sensor side ends 36a2, 36b2. Instead of such a structure, a structure in which the shell side ends 36a1, 36b1 are also supported by other components may be adopted. Specifically, Fig.11 As shown, a structure in which the molded part 65 has an annular portion 66 having magnetic transmission member supporting portions 66a and 66b may be adopted.

[0074] The magnetic transfer component support parts 66a, 66b are slits extending in the radial direction and opening upward. The magnetic transfer component support part 66a supports the shell side end part 36a1 of the magnetic transfer component 36a. The magnetic transfer component support part 66b supports the shell side end part 36b1 of the magnetic transfer component 36b. The magnetic transfer component support parts 66a, 66b may also have a shape other than a slit. For example, in the case where the magnetic transfer components 36a, 36b are formed in a rod shape, the magnetic transfer component support parts 66a, 66b may also be holes that penetrate the annular part 66 in the radial direction. Only at least one of the shell side end parts 36a1, 36b1 and the sensor side end parts 36a2, 36b2 of the magnetic transfer components 36a, 36b is supported.

[0075] The housing side end 36a1 of the magnetic transmission member 36a is arranged to face the outer peripheral surface 41a of the magnetic rotor 41 in the radial direction of the magnetic rotor 41 via the housing 30 in any state from the state where the port 19 is closed (valve closed state) to the state where the port 19 is fully opened (valve open state). The housing side end 36a1 is arranged with a slight gap between the outer peripheral surface 30a of the housing 30. The housing side end 36a1 is arranged close to the outer peripheral surface 30a of the housing 30. In addition, the housing side end 36a1 may be in contact with the outer peripheral surface 30a of the housing 30. The sensor side end 36a2 of the magnetic transmission member 36a is arranged with a slight gap between the magnetic sensor 35a.

[0076] The housing side end portion 36b1 of the magnetic transmission member 36b is arranged so as to face the outer peripheral surface 41a of the magnetic rotor 41 in the radial direction of the magnetic rotor 41 via the housing 30 in any state from the closed valve state to the open valve state. The housing side end portion 36b1 is arranged with a slight gap between the outer peripheral surface 30a of the housing 30. The housing side end portion 36b1 is arranged close to the outer peripheral surface 30a of the housing 30. In addition, the housing side end portion 36b1 may be in contact with the outer peripheral surface 30a of the housing 30. The sensor side end portion 36b2 of the magnetic transmission member 36b is arranged with a slight gap between the magnetic sensor 35b.

[0077] In addition, when viewed from the rotation axis direction of the magnetic rotor 41, the housing side end 36a1 of the magnetic transmission member 36a is arranged on a straight line F1 passing through the rotation axis (axis L) and the center of one pole tooth 63 of the upper stator 61. When viewed from the rotation axis direction of the magnetic rotor 41, the housing side end 36b1 of the magnetic transmission member 36b is arranged on a straight line F2 passing through the rotation axis and the center of one pole tooth 63 of the upper stator 61. The "center" of the pole tooth 63 includes not only the center but also the approximate center, and the same applies to the following description. In the structure having the yoke 61a having a plurality of claw pole type pole teeth 63, when the magnetic rotor 41 stops rotating, it becomes any of the following states: (i) a state in which the pole teeth 63 face the magnetic poles of the magnetic rotor 41; (ii) a state in which the pole teeth 63 face the portion between the adjacent magnetic poles on the outer peripheral surface 41a of the magnetic rotor 41. In the state (i) described above, at the position of the pole teeth 63 observed from the direction of the rotation axis, the radial component contained in the magnetic flux from the N pole toward the S pole is the largest, and the magnetic flux transmitted to the magnetic transmission parts 36a and 36b is the largest. In the state (ii) described above, at the position of the pole teeth 63 observed from the direction of the rotation axis, the radial component contained in the magnetic flux from the N pole toward the S pole is the smallest, and the magnetic flux transmitted to the magnetic transmission parts 36a and 36b is the smallest. Therefore, the state (i) described above and the state (ii) described above can be clearly distinguished, so that the stop position of the magnetic rotor can be obtained with high accuracy. In addition, based on the waveform of the detected magnetic flux, the rotation direction of the magnetic rotor 41 can be obtained.

[0078] In addition, when viewed from the rotation axis direction of the magnetic rotor 41, the first portion A1 as a part of the magnetic transmission member 36a is arranged on the straight line F1, and the first portion B1 as a part of the magnetic transmission member 36b is arranged on the straight line F2. The straight lines F1 and F2 are straight lines along the radial direction. Therefore, since the magnetic flux of the magnetic rotor 41 is easily transmitted in the radial direction, the magnetic flux can be transmitted to a portion farther from the magnetic rotor through the magnetic transmission members 36a and 36b.

[0079] In addition, the second portion A2 as the other part of the magnetic transmission member 36a and the second portion B2 as the other part of the magnetic transmission member 36b are arranged in a direction orthogonal to the mounting surface 85a of the substrate 85 (i.e., the magnetic sensing surface of the magnetic sensors 35a and 35b). Thus, the magnetic sensors 35a and 35b can appropriately detect magnetic flux.

[0080] In the present embodiment, the housing side end 36a1 of the magnetic transmission component 36a and the housing side end 36b1 of the magnetic transmission component 36b are arranged at the same interval (15 degrees) from the adjacent pole teeth 63, but the present invention is not limited to such a structure of the present embodiment. For example, the housing side end 36a1 of the magnetic transmission component 36a and the housing side end 36b1 of the magnetic transmission component 36b may also be arranged at an interval θ [degrees] as shown in the following formula (1).

[0081] θ=(90 / n)+(360×m) / n…(1)

[0082] Here, n is a value that is 1 / 2 of the number of pole teeth of a stator, m is an arbitrary integer, and θ<360 degrees.

[0083] When the housing side end 36a1 of the magnetic transmission member 36a and the housing side end 36b1 of the magnetic transmission member 36b are arranged to satisfy the above formula (1), one of them faces the magnetic pole of the magnetic rotor 41, and the other faces the portion between the adjacent magnetic poles in the outer peripheral surface 41a of the magnetic rotor 41. Therefore, when the magnetic flux transmitted to one of the housing side end 36a1 and the housing side end 36b1 is the maximum, the magnetic flux transmitted to the other is the minimum. Therefore, when the magnetic flux is transmitted to the magnetic sensors 35a and 35b via the magnetic transmission members 36a and 36b, when the magnetic flux detected by one of the magnetic sensors 35a and 35b is the maximum, the magnetic flux detected by the other of the magnetic sensors 35a and 35b is the minimum. Therefore, the rotation angle of the magnetic rotor 41 can be obtained with high accuracy.

[0084] The housing 70 is made of synthetic resin. The housing 70 has a shape along the outer shape of the housing 30 and the stator 60. The housing 70 accommodates the housing 30 and the stator 60 on the inner side. The housing 70 has a cylindrical barrel portion 73 protruding toward the valve body 10 side. The barrel portion 73 is configured to surround the cylindrical portion 12 of the valve body 10. A sealing member 100 is arranged in a compressed state between the barrel portion 73 and the cylindrical portion 12. The sealing member 100 is an annular O-ring made of an elastic material such as a rubber material. The housing 70 is provided with a quadrilateral housing opening 74 facing the side. The terminal support portion 67 protrudes from the housing opening 74.

[0085] The box 80 is made of synthetic resin. The box 80 has a box body 81, a cover 82, and a connector 83. The box body 81 is formed in a rectangular box shape with a side opening. The cover 82 is formed in a flat plate shape that closes the side opening of the box body 81. The connector 83 is formed in a cylindrical shape extending upward from the box body 81.

[0086] The box body 81 accommodates a substrate 85. The substrate 85 is a printed circuit board on which electronic components are mounted. Magnetic sensors 35a and 35b are mounted on the mounting surface 85a of the substrate 85. A computing device composed of a computer or the like may also be mounted on the substrate 85. The computing device is a structure that calculates the rotation angle of the magnetic rotor 41 and the valve opening (opening of the port 19) based on the signals output by the magnetic sensors 35a and 35b, for example.

[0087] The box body 81 has a side wall portion 81a opposite to the cover body 82. The side wall portion 81a is provided with a plurality of protrusions 81b and a quadrilateral box opening 84. The box opening 84 is connected to the housing opening 74 of the housing 70. The peripheral edge portion of the housing opening 74 in the housing 70 and the peripheral edge portion of the box opening 84 in the box body 81 are joined, for example, by ultrasonic welding, infrared welding, or the like.

[0088] The beams 37 of the magnetic transmission unit 38 are mounted on the plurality of protrusions 81b. The magnetic transmission members 36a and 36b are arranged to be inserted through the box opening 84 and the housing opening 74. In addition, the substrate 85 is mounted on the plurality of protrusions 81b. The mounting surface 85a of the substrate 85 faces the housing 30 in the radial direction.

[0089] In the electric valve 1, the cylindrical portion 12 of the valve body 10, the port 19, the housing 30, the magnetic rotor 41, the valve shaft holder 42, the guide bushing 43, the valve shaft 44, the valve core 50, the stator 60 (the upper stator 61, the lower stator 62, the annular portion 66 of the molded part 65), and the cylindrical portion 73 of the housing 70 have their respective axes aligned with the axial direction L. In other words, all of these components are coaxially arranged. The axial direction L is aligned with the up-down direction.

[0090] Next, the operation of the electric valve 1 will be described.

[0091] In the electric valve 1, the upper stator 61 and the lower stator 62 are energized to rotate the magnetic rotor 41 in one direction. The valve shaft holder 42 rotates together with the magnetic rotor 41. The magnetic rotor 41 and the valve shaft holder 42 move downward (i.e., one side in the direction of the rotation axis) by the thread feed action of the internal thread 42c of the valve shaft holder 42 and the external thread 43c of the guide bushing 43. The valve shaft 44 also moves downward together with the valve shaft holder 42, so that the valve core 50 closes the port 19 (valve closed state).

[0092] In addition, in the electric valve 1, the upper stator 61 and the lower stator 62 are energized to rotate the magnetic rotor 41 in the other direction. The valve shaft holder 42 rotates together with the magnetic rotor 41. The magnetic rotor 41 and the valve shaft holder 42 move upward (i.e., the other side of the rotation axis direction) by the thread feed action of the internal thread 42c of the valve shaft holder 42 and the external thread 43c of the guide bushing 43. The valve shaft 44 also moves upward together with the valve shaft holder 42, so that the valve core 50 opens the port 19 (valve opening state).

[0093] When the magnetic rotor 41 rotates, the positional relationship between each N pole and each S pole provided on the outer peripheral surface 41a and the housing side end 36a1 of the magnetic transmission member 36a and the housing side end 36b1 of the magnetic transmission member 36b changes, so that the direction and magnitude of the magnetic flux density transmitted to the magnetic sensors 35a and 35b via the magnetic transmission members 36a and 36b change. As a result, the signal output from the magnetic sensors 35a and 35b changes according to the rotation angle of the magnetic rotor 41, and the rotation angle and rotation direction of the magnetic rotor 41 can be obtained based on the signal.

[0094] The present inventors analyzed the relationship between the shape, extension direction, and number of magnetic transmission members and the transmission method of the magnetic flux of the magnet rotor 41 using simulation. Figure 12 to Figure 21 Indicates the parsing result. Figure 12 to Figure 21 Schematically shows how magnetic flux is transmitted from the magnetic rotor to the magnetic transmission component. Figure 12 to Figure 21 In the figure, the darker areas of the magnetic transmission parts 36a and 36b indicate areas where a predetermined amount of magnetic flux is transmitted. The darker the area, the easier it is to transmit the magnetic flux. In addition, the darker areas in the magnetic rotor indicate magnetic poles (N poles and S poles). Fig.15 , Fig.19 , Fig.21 In FIG. 1 , the magnetic field lines connecting the magnetic poles of the magnetic rotor are schematically represented by black lines. Fig.14 and Fig.15 , Fig.18 and Fig.19 as well as Fig. 20 and Fig.21 The same structure is shown in different drawings (stereoscopic drawing, top view). Table 1 shows the details of each drawing.

[0095] [Table 1]

[0096]

[0097]

[0098] Figure 12 to Figure 15 Indicates a structure using a magnetic transmission component 36a. Fig.12 , Fig.13 , Fig.14 In the order of the darker colors, the darker the area, the larger the expansion. And, in these three structures, it can be seen that Fig.14 The structure shown is able to transfer magnetic flux to the location farthest from the magnetic rotor. Fig.14 The structure shown is a structure in which one elongated plate-shaped magnetic transmission member 36 a is arranged to extend in the radial direction of the magnetic rotor 41 .

[0099] Figure 16 to Figure 19 The structure using two magnetic transmission components 36a and 36b is shown. Fig.16 , Fig.17 , Fig.18 In the order of the darker colors, the darker the area, the larger the expansion. And, in these three structures, it can be seen that Fig.18 The structure shown is able to transfer magnetic flux to the location farthest from the magnetic rotor. Fig.18 The structure shown is a structure in which two elongated plate-shaped magnetic transmission members 36a and 36b are arranged to extend in the radial direction of the magnetic rotor 41. Fig.18 Compared with the structure using one magnetic transmission member 36a, the structure shown in FIG. 3 can also transmit magnetic flux to a location further away from the magnetic rotor 41. Fig.19 As shown, the magnetic lines of force extend between the magnetic transmission members 36a and 36b. As can be seen from this, a magnetic circuit is formed by the N pole, the magnetic transmission members 36a and 36b, and the S pole.

[0100] Fig. 20 , Fig.21 FIG. 4 shows a structure in which two magnetic transmission members 36a and 36b bent at an obtuse angle are arranged so that only the first portions A1 and B1 extend in the radial direction of the magnetic rotor 41. Fig. 20 In the structure shown, Fig.18 The structure shown is the same, and the darker area is expanded. Fig. 20 In the structure shown, it is also possible to Fig.18 The structure shown in FIG. 4 also transmits magnetic flux to a position away from the magnetic rotor 41. Fig.21 As shown, the magnetic lines of force extend between the magnetic transmission members 36a and 36b. As can be seen from this, a magnetic circuit is formed by the N pole, the magnetic transmission members 36a and 36b, and the S pole.

[0101] The above analysis results show that the magnetic flux of the magnetic rotor can be effectively transmitted by arranging the elongated plate-shaped magnetic transmission member to extend in the radial direction of the magnetic rotor 41. In addition, it is clear that the structure using two magnetic transmission members can more effectively transmit the magnetic flux of the magnetic rotor than the structure using one magnetic transmission member.

[0102] As described above, the electric valve 1 according to the present embodiment has the magnetic transmission components 36a, 36b arranged between the housing 30 and the magnetic sensors 35a, 35b mounted on the substrate 85. The magnetic rotor 41 is arranged inside the housing 30. On the outer peripheral surface 41a of the magnetic rotor 41, a plurality of N poles and a plurality of S poles extending in the rotation axis direction of the magnetic rotor 41 are arranged alternately in the circumferential direction. And, the housing side end portions 36a1, 36b1 of the magnetic transmission components 36a, 36b are arranged to face the magnetic rotor 41 in the radial direction via the housing 30. The magnetic flux generated at the magnetic poles (N poles, S poles) of the magnetic rotor 41 is easily transmitted in the radial direction. Therefore, by arranging the housing side end portions 36a1, 36b1 of the magnetic transmission components 36a, 36b to face the magnetic rotor 41 in the radial direction, the magnetic flux can be effectively transmitted to the magnetic transmission components 36a, 36b. Thus, a large amount of magnetic flux is transmitted to the magnetic sensors 35a and 35b via the magnetic transmission members 36a and 36b, and the magnetic flux of the magnetic rotor 41 can be reliably detected.

[0103] Furthermore, the stator 60 may be provided with magnetic transmission member support portions 66a and 66b that support the housing-side ends 36a1 and 36b1 of the magnetic transmission members 36a and 36b. Thus, the housing-side ends 36a1 and 36b1 of the magnetic transmission members 36a and 36b can be appropriately positioned relative to the pole teeth 63 of the stator 60.

[0104] In addition, the magnetic rotor 41 moves downward (on one side in the direction of the rotation axis) when the port 19 is closed, and moves upward (on the other side in the direction of the rotation axis) when the port 19 is opened. The housing side ends 36a1, 36b1 of the magnetic transmission components 36a, 36b are arranged above the plurality of pole teeth 63 of the upper stator 61 of the stator 60. In addition, the housing side ends 36a1, 36b1 are arranged to face the magnetic rotor 41 in the radial direction across the housing 30 in the state of closing the port 19. Thus, the magnetic rotor 41 and the housing side ends 36a1, 36b1 of the magnetic transmission components 36a, 36b face each other in the radial direction in any state from the closed valve state to the open valve state. Therefore, the magnetic flux of the magnetic rotor 41 can be reliably detected, and the rotation angle of the magnetic rotor 41 can be obtained with high accuracy.

[0105] The mounting surface 85b of the substrate 85 is disposed to face the housing 30 in the radial direction. Thus, since the magnetic flux is easily transmitted in the radial direction, the magnetic flux can be efficiently transmitted to the magnetic sensors 35a and 35b via the magnetic transmission members 36a and 36b.

[0106] In addition, it also has: a housing 70 that accommodates the housing 30 and the stator 60, a box 80 that accommodates the substrate 85, and a magnetic transfer unit 38 having magnetic transfer components 36a, 36b and a beam 37 that supports them. The housing opening 74 provided in the housing 70 is connected to the box opening 84 provided in the box 80. The peripheral edge of the housing opening 74 in the housing 70 is joined to the peripheral edge of the box opening 84 in the box 80. In addition, the magnetic transfer components 36a, 36b of the magnetic transfer unit 38 are inserted through the box opening 84 and the housing opening 74, and the beam 37 is installed in the box 80. As a result, the magnetic transfer components 36a, 36b can be easily arranged near the housing by inserting the magnetic transfer components 36a, 36b through the box opening 84 and the housing opening 74. In addition, since the peripheral edge of the housing opening 74 in the housing 70 is joined to the peripheral edge of the box opening 84 in the box 80, the electric valve 1 can ensure airtightness.

[0107] The electric valve 1 of the above-mentioned embodiment has a structure in which the magnetic rotor 41 moves in the direction of the rotation axis, but the electric valve of the present invention may also have a structure in which the position of the magnetic rotor 41 in the direction of the rotation axis is fixed. In any structure, it is preferable that the position of the housing side end portions 36a1, 36b1 of the magnetic transmission members 36a, 36b in the direction of the rotation axis is within the range of the full length of the magnetic rotor 41 (i.e., from the lower end to the upper end of the magnetic rotor 41) in any state from the closed valve state to the open valve state. Thus, the magnetic rotor 41 and the housing side end portions 36a1, 36b1 of the magnetic transmission members 36a, 36b face each other in the radial direction from the closed valve state to the open valve state. Therefore, the magnetic flux of the magnetic rotor 41 can be reliably detected, and the rotation angle of the magnetic rotor 41 can be obtained with high accuracy. In addition, it is preferable that the positions of the upper stator 61 and the lower stator 62 of the stator 60 in the direction of the rotation axis are within the range of the full length of the magnetic rotor 41 in any state from the closed valve state to the open valve state. Thus, from the valve closed state to the valve open state, the magnetic forces of the upper stator 61 and the lower stator 62 can be effectively applied to the magnet rotor 41 , so that the magnet rotor 41 can be effectively rotated.

[0108] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. As long as it does not violate the gist of the present invention, the structures obtained by adding, deleting, and designing the structural elements of the above-mentioned embodiments by those skilled in the art, and the structures obtained by appropriately combining the features of the embodiments are also included in the scope of the present invention.

[0109] Explanation of symbols

[0110] 1 ... electric valve, 10 ... valve body, 11 ... body portion, 11a ... upper surface, 11b ... internal thread portion, 12 ... cylindrical portion, 12b ... external thread portion, 13 ... valve chamber, 17, 18 ... flow path, 19 ... port, 20 ... flange portion, 30 ... housing, 30a ... outer peripheral surface, 35a, 35b ... magnetic sensor, 36a, 36b ... magnetic transmission member, 36a1, 36b1 ... housing side end portion, 36a2, 36b2 …Sensor side end, A1, B1…First part, A2, B2…Second part, 38…Magnetic transfer unit, 40…Drive mechanism, 41…Magnetic rotor, 41a…Outer peripheral surface, 42…Valve shaft holder, 42c…Internal thread, 43…Guide bushing, 43a…Large diameter cylindrical part, 43b…Small diameter cylindrical part, 43c…External thread, 44…Valve shaft, 44a…Trunk, 44b…Upper small diameter part, 45…Support ring , 46... push nut, 47... compression coil spring, 48... upper stopper, 49... lower stopper, 50... valve core, 60... stator, 60a... inner peripheral surface, 60b... fitting hole, 61... upper stator, 61a... yoke, 61b... coil frame, 61c... coil, 62... lower stator, 62a... yoke, 62b... coil frame, 62c... coil, 63, 64... pole teeth, 63a, 64a... lower pole teeth, 63 b, 64b…upward pole teeth, 65…molding, 66…ring-shaped portion, 66a, 66b…magnetic transfer component support portion, 66c…upper surface, 67…terminal support portion, 67a…top end, 68…terminal, 70…housing, 73…cylindrical portion, 74…housing opening, 80…box, 81…box body, 81a…side wall portion, 81b…convex portion, 82…cover body, 83…connector, 84…box opening, 100…sealing member

Claims

1. An electric valve, comprising: a valve body; a cylindrical shell, the shell being mounted on the valve body; a cylindrical magnetic rotor, the magnetic rotor being arranged inside the shell; a valve core, the valve core being driven to open and close a port in the valve body by the rotation of the magnetic rotor; a stator, the stator being arranged outside the shell; and a substrate, the substrate being mounted with a magnetic sensor, wherein the electric valve is characterized in that: A magnetic transmission component is arranged between the housing and the magnetic sensor. On the outer peripheral surface of the magnetic rotor, one or more N poles and S poles extending in the direction of the rotation axis of the magnetic rotor are arranged alternately in the circumferential direction. The end of the magnetic transmission member on the housing side is arranged to face the magnetic rotor in the radial direction via the housing. The magnetic transmission component is formed into a long and thin plate or rod extending in the radial direction. A portion of the magnetic transmission member including the end portion on the housing side is arranged along the radial direction.

2. The electric valve according to claim 1, characterized in that: The stator is provided with a magnetic transmission member support portion that supports an end portion of the magnetic transmission member on the housing side.

3. The electric valve according to claim 1 or 2, characterized in that: The stator has a plurality of pole teeth. When viewed from the rotation axis direction, the end portion of the magnetic transmission member on the housing side is arranged on a straight line passing through the rotation axis of the magnetic rotor and the center of one of the plurality of pole teeth.

4. The electric valve according to claim 3, characterized in that: The other portion of the magnetic transmission member including the end portion on the magnetic sensor side is arranged along a direction orthogonal to the magnetically sensitive surface of the magnetic sensor.

5. The electric valve according to claim 1, characterized in that: When the port is closed, the magnetic rotor moves to one side of the rotation axis direction, and when the port is opened, the magnetic rotor moves to the other side of the rotation axis direction. The end portion of the magnetic transmission member on the housing side is arranged on the other side relative to the plurality of pole teeth of the stator, and is arranged to face the magnetic rotor in a radial direction via the housing in a state where the port is closed.

6. The electric valve according to claim 1, characterized in that: In any state from a state in which the port is closed to a state in which the port is fully opened, the position of the end portion of the magnetic transmission member on the housing side in the direction of the rotation axis is within the range of the full length of the magnetic rotor.

7. The electric valve according to claim 6, characterized in that: In any state from a state in which the port is closed to a state in which the port is fully opened, the position of the stator in the rotation axis direction is within the range of the full length of the magnetic rotor.

8. The electric valve according to claim 1, characterized in that: The mounting surface of the magnetic sensor in the substrate is arranged to be opposed to the housing in a radial direction.

9. The electric valve according to claim 8, characterized in that: Also available: a housing that accommodates the housing and the stator; a box that accommodates the substrate; and a magnetic transmission unit, the magnetic transmission unit comprising the magnetic transmission component and a support body supporting the magnetic transmission component, A housing opening provided in the housing is connected to a box opening provided in the box, and a peripheral edge portion of the housing opening in the housing is engaged with a peripheral edge portion of the box opening in the box, The magnetic transmission member of the magnetic transmission unit is inserted through the box opening and the housing opening, and the support body is attached to the box.

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