Motorised valve

Abstract

An electric valve with a small height dimension and capable of accurately detecting the rotation angle of a magnetic rotor is provided. The magnetic rotor (41A) of the electric valve (1A) integrally has a first magnetic pole portion (41a), a magnetic buffer portion (41b), and a second magnetic pole portion (41c) connected sequentially along its rotation axis. The first magnetic pole portion (41a) is provided with a plurality of N poles and a plurality of S poles arranged alternately in the circumferential direction. The second magnetic pole portion (41c) is provided with a N pole and an S pole arranged alternately in the circumferential direction. The stator unit (80) has an angle sensor (96) for detecting the rotation angle of the second magnetic pole portion (41c). Moreover, the materials constituting the first magnetic pole portion (41a) are different from the materials constituting the second magnetic pole portion (41c).

Description

Technical Field

[0001] This invention relates to an electric valve. Background Technology

[0002] Patent Document 1 discloses an example of a conventional electric valve. The electric valve of Patent Document 1 has a housing, a magnetic rotor, a permanent magnet, a stator, and a base plate. The housing has a cylindrical shape with its upper end sealed. The magnetic rotor is disposed inside the housing. The permanent magnet is disposed above the magnetic rotor inside the housing. The permanent magnet rotates together with the magnetic rotor. The stator is disposed outside the housing. An angle sensor is mounted on the base plate to detect the rotation angle of the permanent magnet (specifically, the rotation angle of the magnetic field generated by the permanent magnet).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-135908

[0006] The technical problem that the invention aims to solve

[0007] In the aforementioned electric valve, the angle sensor is positioned above the upper part of the housing. Therefore, the height of the electric valve is relatively large. Thus, by placing the angle sensor on the side of the housing, the height of the electric valve can be reduced. However, in the electric valve of Patent Document 1, magnetic poles are formed by the magnetic field lines of a permanent magnet extending upwards from and into the upper surface. Therefore, the strength of the magnetic field generated by the permanent magnet is relatively weak in the space located on the side of the housing. If the angle sensor is placed on the side of the housing, the rotation angle of the permanent magnet may not be accurately detected.

[0008] In such an electric valve, by employing a magnetic rotor that integrally comprises a drive unit that generates rotational force along with the stator and a detection unit that generates a magnetic field detected by an angle sensor, the number of parts can be reduced and assembly time lowered. In the drive unit, multiple N poles and multiple S poles are arranged alternately circumferentially. In the detection unit, at least one N pole and at least one S pole are arranged alternately circumferentially. However, even when only one of the drive unit or the detection unit requires a large magnetic force, the magnetic rotor as a whole must be constructed from a material capable of generating a large magnetic force. Therefore, the material cost of the magnetic rotor increases. Summary of the Invention

[0009] Therefore, the object of the present invention is to provide an electric valve that can reduce assembly time and material costs associated with magnetic rotors.

[0010] Technical means for solving technical problems

[0011] To achieve the above objectives, one embodiment of the electric valve of the present invention includes: a cylindrical housing, a magnetic rotor disposed inside the housing, and a stator unit having a stator disposed outside the housing. The magnetic rotor integrally has a first magnetic pole portion and a second magnetic pole portion arranged in the direction of the rotation axis of the magnetic rotor. The first magnetic pole portion is provided with a plurality of N poles and a plurality of S poles arranged alternately in the circumferential direction, and the second magnetic pole portion is provided with at least one N pole and at least one S pole arranged alternately in the circumferential direction. The stator unit has an angle sensor for detecting the rotation angle of the second magnetic pole portion, and the materials constituting the first magnetic pole portion and the materials constituting the second magnetic pole portion are different.

[0012] In this invention, preferably, the magnetic rotor integrally has a first magnetic pole portion, a magnetic buffer portion, and a second magnetic pole portion connected sequentially along the rotation axis, wherein the magnetic buffer portion is the unmagnetized portion.

[0013] In this invention, preferably, the length of the rotation axis of the magnetic buffer portion is such that the magnetic field generated by the first magnetic pole portion does not affect the magnetic field generated by the second magnetic pole portion.

[0014] In this invention, preferably, the magnetization direction of the second magnetic pole portion is orthogonal to the rotation axis, and the angle sensor and the housing are arranged in a direction orthogonal to the rotation axis.

[0015] In this invention, preferably, the magnetic rotor rotates and moves along the direction of the rotation axis, and the angle sensor and the second magnetic pole portion are always arranged in a direction orthogonal to the rotation axis.

[0016] In this invention, preferably, the first magnetic pole portion is composed of a first synthetic resin containing a first magnetic material, and the second magnetic pole portion is composed of a second synthetic resin containing a second magnetic material. The type of the first magnetic material is different from the type of the second magnetic material, or the type of the first magnetic material is the same as the type of the second magnetic material, and the mixing rate of the first magnetic material in the first synthetic resin is different from the mixing rate of the second magnetic material in the second synthetic resin.

[0017] In this invention, preferably, the first magnetic pole portion is composed of a first synthetic resin containing a first magnetic material, the second magnetic pole portion is composed of a second synthetic resin containing a second magnetic material, and the magnetic buffer portion is composed of the first synthetic resin, the second synthetic resin, or a metal. The type of the first magnetic material is different from the type of the second magnetic material, or the type of the first magnetic material is the same as the type of the second magnetic material, and the mixing rate of the first magnetic material in the first synthetic resin is different from the mixing rate of the second magnetic material in the second synthetic resin.

[0018] In this invention, preferably, the magnetic rotor is a molded body in which the first magnetic pole portion and the second magnetic pole portion are integrally formed by two-color molding.

[0019] In this invention, preferably, the magnetic rotor is a molded body in which the first magnetic pole portion, the magnetic buffer portion, and the second magnetic pole portion are integrally formed by two-color molding.

[0020] The effects of the invention

[0021] According to the present invention, the magnetic rotor integrally comprises a first magnetic pole portion and a second magnetic pole portion arranged along its rotation axis. The first magnetic pole portion is provided with a plurality of N poles and a plurality of S poles arranged alternately in a circumferential direction. The second magnetic pole portion is provided with at least one N pole and at least one S pole arranged alternately in a circumferential direction. The stator unit has an angle sensor for detecting the rotation angle of the second magnetic pole portion. Furthermore, the materials constituting the first magnetic pole portion and the second magnetic pole portion are different. Therefore, when only one of the first and second magnetic pole portions requires a larger magnetic force, the first and second magnetic pole portions can be constructed using materials corresponding to the required magnetic force, respectively. Thus, assembly time and material costs associated with the magnetic rotor can be reduced. Attached Figure Description

[0022] Figure 1 This is a longitudinal sectional view of the electric valve involved in the first reference example.

[0023] Figure 2 It is a schematic representation Figure 1 The diagram shows the configuration of the permanent magnet and angle sensor in the electric valve.

[0024] Figure 3 This is a diagram that schematically illustrates the relationship between the angle sensor and the magnetic field lines of the permanent magnet at the first rotation angle.

[0025] Figure 4 This is a diagram that schematically illustrates the relationship between the angle sensor and the magnetic field lines of the permanent magnet at the second rotation angle.

[0026] Figure 5It is a graph showing the relationship between the rotation angle of the permanent magnet and the electrical signal output by the angle sensor.

[0027] Figure 6 This is a longitudinal sectional view of the electric valve according to the first embodiment of the present invention.

[0028] Figure 7 yes Figure 6 A three-dimensional view and a front view of the magnetic rotor of the electric valve.

[0029] Figure 8 yes Figure 6 Top and bottom views of the magnetic rotor of the electric valve.

[0030] Figure 9 yes Figure 7 The three-dimensional and front views of the magnetic rotor are shown in the modified examples.

[0031] Figure 10 This is a longitudinal sectional view showing the state where the opening area of ​​the valve port is minimized in the electric valve involved in the second reference example.

[0032] Figure 11 It means in Figure 10 A longitudinal sectional view of an electric valve in the state where the valve port opening area is at its maximum.

[0033] Figure 12 This is a longitudinal sectional view showing the state where the opening area of ​​the valve port is at its minimum in the electric valve according to the second embodiment of the present invention.

[0034] Figure 13 It means in Figure 12 A longitudinal sectional view of an electric valve in the state where the valve port opening area is at its maximum. Detailed Implementation

[0035] (First Reference Example)

[0036] The following is for reference Figures 1-5 The electric valve involved in the first reference example will be described. The electric valve 1 involved in this reference example is used, for example, in a refrigeration cycle to adjust the refrigerant flow.

[0037] Figure 1 This is a longitudinal sectional view of the electric valve involved in the first reference example. Figure 2 It is a schematic representation Figure 1 The diagram shows the configuration of the permanent magnet and angle sensor in the electric valve. Figure 3 This is a diagram that schematically illustrates the relationship between the angle sensor and the magnetic field lines of the permanent magnet at the first rotation angle. Figure 3 This indicates the case where the magnetic field lines passing through the angle sensor are mainly oriented in the X direction. Figure 4This is a diagram schematically showing the relationship between the angle sensor and the magnetic field lines of the permanent magnet at the second rotation angle. Figure 4 This indicates the case where the magnetic field lines passing through the angle sensor are mainly oriented in the Y direction. Figure 3 The permanent magnet shown Figure 4 The difference in rotation angle of the permanent magnet shown is 90 degrees. Figure 5 This is a graph showing the relationship between the rotation angle of the permanent magnet and the electrical signal output by the angle sensor. In each graph, the X direction (represented by arrow X), the Y direction (represented by arrow Y), and the Z direction (represented by arrow Z) are orthogonal to each other.

[0038] like Figure 1 As shown, the electric valve 1 involved in this reference example has a valve body 10, a retainer 20, a valve core support member 25, a housing 30 as a housing, a drive mechanism 40, a valve core 70, and a stator unit 80.

[0039] The valve body 10 has a cuboid shape. The valve body 10 has a valve chamber 13 and a valve port 14 connected to the valve chamber 13. The valve body 10 has a first passage 17 and a second passage 18. One end of the first passage 17 is connected to the valve chamber 13, and the other end of the first passage 17 opens on the left side 10a of the valve body 10. One end of the second passage 18 is connected to the valve chamber 13 via the valve port 14, and the other end of the second passage 18 opens on the right side 10b of the valve body 10. The valve body 10 has a mounting hole 19. The mounting hole 19 opens on the upper surface 10c of the valve body 10. An internal thread is formed on the inner circumferential surface of the mounting hole 19. The valve chamber 13 opens on the bottom surface 19a of the mounting hole 19.

[0040] The retainer 20 has a cylindrical shape. An external thread is formed on the lower part of the outer circumferential surface of the retainer 20. The external thread of the retainer 20 engages with the internal thread of the mounting hole 19 of the valve body 10. The retainer 20 is mounted to the valve body 10 via a threaded structure.

[0041] The valve core support member 25 has a cylindrical shape. It is disposed inside the mounting hole 19 between the valve body 10 and the retainer 20. The lower part of the valve core support member 25 is pressed into the valve chamber 13 through the mounting hole 19. A downward-facing annular plane 25a is formed on the outer peripheral surface of the valve core support member 25. The annular plane 25a abuts against the bottom surface 19a of the mounting hole 19. The valve core support member 25 supports the valve core 70 so that it can move in the vertical direction (Z direction).

[0042] The housing 30 has a cylindrical shape. The upper end of the housing 30 is sealed, and the lower end is open. The lower end of the housing 30 engages with the outer periphery of a ring-shaped engaging member 35. The upper part of a retainer 20 is disposed inside the engaging member 35. The inner periphery of the engaging member 35 engages with the retainer 20. The housing 30 is fixed to the valve body 10 via the engaging member 35 and the retainer 20.

[0043] The drive mechanism 40 moves the valve core 70 in the vertical direction. The drive mechanism 40 includes a magnetic rotor 41, a permanent magnet 45, a planetary gear mechanism 50, a guide member 60, a drive shaft 65, and a ball 68.

[0044] The magnetic rotor 41 has a cylindrical shape. The outer diameter of the magnetic rotor 41 is smaller than the inner diameter of the housing 30. The magnetic rotor 41 is configured to rotate inside the housing 30. A circular plate-shaped connecting member 42 engages with the upper end of the magnetic rotor 41. The connecting member 42 seals the upper end of the magnetic rotor 41. The rotor shaft 43 passes through the center of the connecting member 42. The magnetic rotor 41 is connected to the rotor shaft 43 via the connecting member 42. The rotor shaft 43 rotates together with the magnetic rotor 41.

[0045] The magnetic rotor 41 has multiple N poles and multiple S poles. The multiple N poles and multiple S poles extend in the direction of the axis L. The multiple N poles and multiple S poles are alternately arranged circumferentially on the outer peripheral surface of the magnetic rotor 41. The axis L is parallel to the Z direction.

[0046] A permanent magnet 45 is disposed above the magnetic rotor 41 on the inner side of the housing 30. The permanent magnet 45 has a circular plate shape. The permanent magnet 45 has a circular shape when viewed from the axis L. Alternatively, the permanent magnet 45 can also be a straight rod shape. The permanent magnet 45 is fixed to the upper end of the rotor shaft 43. The permanent magnet 45 is coaxially disposed with the magnetic rotor 41 and rotates together with the magnetic rotor 41. The permanent magnet 45 rotates about the rotation axis of the magnetic rotor 41. The rotation axis of the magnetic rotor 41 is aligned with the axis L. The direction of the axis L is the direction of the rotation axis. A circular plate-shaped magnetic shielding member 46 is disposed between the magnetic rotor 41 and the permanent magnet 45. The magnetic shielding member 46 is a soft magnetic material with high permeability, such as silicon iron. The magnetic shielding member 46 is fixed to the rotor shaft 43. The magnetic shielding member 46 absorbs the magnetic flux generated by the magnetic rotor 41. The magnetic shielding member 46 suppresses the deformation of the magnetic field generated by the permanent magnet 45 due to the magnetic field generated by the magnetic rotor 41. The magnetic rotor 41 and the permanent magnet 45 do not move in the direction of axis L.

[0047] like Figures 2-4 As shown, the permanent magnet 45 has one N pole and one S pole. An N pole is disposed in one portion (first portion 45n) of the permanent magnet 45 divided by the diameter K, and an S pole is disposed in the other portion (second portion 45s). The N pole and the S pole are in a direction orthogonal to the axis L and to the diameter K. Figure 3 The X direction in Figure 4 The permanent magnet 45 is magnetized in a direction orthogonal to the axis L and the diameter K. Therefore, as shown in the figure... Figure 3 , Figure 4 As shown, the magnetic field lines F of the permanent magnet 45 extend from the outer peripheral surface of the first part 45n and enter the outer peripheral surface of the second part 45s in a direction orthogonal to the axis L (parallel to the XY plane). Furthermore, the permanent magnet 45 may have at least one N pole and at least one S pole. For example, the permanent magnet 45 may have two N poles and two S poles arranged alternately in the circumferential direction.

[0048] A planetary gear mechanism 50 is disposed inside the magnetic rotor 41. The planetary gear mechanism 50 includes a gear housing 51, a fixed gear ring 52, a sun gear 53, multiple planetary gears 54, a gear carrier 55, an output gear 56, and an output shaft 57. The gear housing 51 has a cylindrical shape. The gear housing 51 is coaxially engaged with the upper end of the cage 20. The fixed gear ring 52 is an internal gear. The fixed gear ring 52 is fixed to the upper end of the gear housing 51. The sun gear 53 is coaxially disposed with the connecting member 42. The sun gear 53 and the connecting member 42 are integrated. The rotor shaft 43 passes through the sun gear 53. The sun gear 53 rotates together with the magnetic rotor 41 and the connecting member 42. Multiple planetary gears 54 are disposed between the fixed gear ring 52 and the sun gear 53. The gear carrier 55 has a circular plate shape. The rotor shaft 43 passes through the center of the gear carrier 55. The gear carrier 55 is rotatable around the rotor shaft 43. The gear carrier 55 supports multiple planetary gears 54 for rotation. The output gear 56 has a bottomed cylindrical shape. The output gear 56 is an internal gear. Multiple planetary gears 54 are arranged between the output gear 56 and the sun gear 53. The output shaft 57 has a cylindrical shape. The upper part of the output shaft 57 is disposed in a hole formed in the bottom of the output gear 56. The output shaft 57 is fixed to the output gear 56. A slit 57a extending in the vertical direction is formed in the lower part of the output shaft 57. The rotation of the sun gear 53 is transmitted to the output shaft 57 by the fixed gear ring 52, the multiple planetary gears 54, the gear carrier 55, and the output gear 56.

[0049] The guide member 60 has a cylindrical shape. The guide member 60 is disposed on the inner side of the upper part of the retainer 20. An internal thread is formed on the lower part of the inner circumferential surface of the guide member 60. An output shaft 57 is disposed on the inner side of the guide member 60. The guide member 60 supports the output shaft 57 so that it can rotate.

[0050] The drive shaft 65 has a cylindrical portion 66 and a flat portion 67. The flat portion 67 is connected to the upper end of the cylindrical portion 66. The cylindrical portion 66 and the flat portion 67 are integrally formed. An external thread is formed on the outer peripheral surface of the cylindrical portion 66. The external thread of the cylindrical portion 66 engages with the internal thread of the guide member 60. The flat portion 67 is disposed in the slit 57a of the output shaft 57 in a manner that allows it to move in the vertical direction. The drive shaft 65 rotates via the output shaft 57 and moves in the vertical direction by means of threaded feed.

[0051] The valve core 70 has a valve stem 71, a valve portion 72, a spring seat portion 73, and a ball seat portion 74. The valve stem 71 is cylindrical. The valve stem 71 is disposed inside the valve core support member 25. The valve stem 71 is supported by the valve core support member 25 and is movable in the vertical direction. The valve portion 72 is disposed at the lower end of the valve stem 71. The valve portion 72 is annular. The valve portion 72 protrudes radially outward from the outer circumferential surface of the valve stem 71. The valve portion 72 is opposite to the valve port 14 in the vertical direction. The spring seat portion 73 is cylindrical. The spring seat portion 73 engages with the upper end of the valve stem 71. The spring seat portion 73 has a flange portion 73a protruding radially outward. The ball seat portion 74 has a circular flat plate portion and a protrusion connected to the lower surface of the flat plate portion. The flat plate portion of the ball seat portion 74 contacts a ball 68, and the protrusion fits into a hole formed in the spring seat portion 73. A ball 68 is disposed between the ball seat portion 74 and the drive shaft 65. An opening spring 75 is disposed between the flange portion 73a of the spring seat portion 73 and the valve core support member 25. The opening spring 75 is a compression coil spring. The opening spring 75 pushes the valve core 70 (flange portion 73a) upward. The valve core 70 moves forward and backward relative to the valve port 14 via the valve portion 72, thereby steplessly (including substantially steplessly) changing the opening area of ​​the valve port 14. The minimum area of ​​the valve port 14 can also be greater than zero (i.e., the valve port 14 is slightly open). Alternatively, the minimum area of ​​the valve port 14 can also be zero (i.e., the valve port 14 is fully closed).

[0052] The stator unit 80 includes a stator 81, a cover 90, and a base plate 95. The stator 81 has a cylindrical shape. A housing 30 is disposed inside the stator 81. The stator 81 and the magnetic rotor 41 are arranged in a direction orthogonal to the axis L through the housing 30. The stator 81 and the magnetic rotor 41 together constitute a stepper motor.

[0053] The cover 90 is made of resin. The cover 90 houses the stator 81 and the substrate 95. The cover 90 has a cover body 91, a cover 92, and a connector 93. The cover body 91 is integrally formed with the stator 81. The cover body 91 has a first peripheral wall portion 91a, an upper wall portion 91b, a second peripheral wall portion 91c, and a cylindrical portion 91d. The stator 81 is embedded in the inner peripheral surface of the first peripheral wall portion 91a. The upper wall portion 91b is connected to the upper end of the first peripheral wall portion 91a. The upper wall portion 91b has a dome shape. The upper end of the outer casing 30 is disposed inside the upper wall portion 91b. The second peripheral wall portion 91c is connected to the first peripheral wall portion 91a. The second peripheral wall portion 91c extends upward from the first peripheral wall portion 91a. The cylindrical portion 91d extends downward from the lower end of the first peripheral wall portion 91a. The lower end of the cylindrical portion 91d contacts the upper surface 10c of the valve body 10. A retainer 20 is disposed on the inner side of the cylindrical portion 91d. The cover 92 has a flat plate shape. The cover 92 engages with the upper end of the second peripheral wall portion 91c of the cover body 91. The connector 93 has an orientation towards... Figure 1 The cylindrical shape extends horizontally. The connector 93 is integrated with the cover 92. The cover body 91 and the cover 92 define the substrate receiving space 94.

[0054] An electronic component, including an angle sensor 96, is mounted on a substrate 95. The substrate 95 is disposed in a substrate receiving space 94 and is fixed to a boss 91e on the cover body 91 by screws. A terminal 84 for connecting to a coil of the stator 81 is connected to the substrate 95. The substrate 95 has a through hole 95a for the upper wall portion 91b of the cover body 91.

[0055] Angle sensor 96 is a magnetic angle sensor. Angle sensor 96 is mounted on the lower surface of substrate 95. Angle sensor 96 is disposed near the outer peripheral surface of housing 30. Angle sensor 96 is located between housing 30 and the housing via cover body 91 in a direction orthogonal to axis L. Figure 1 The permanent magnet 45 is arranged in the X direction. Furthermore, the angle sensor 96 is arranged in a direction orthogonal to the axis L, separated from the housing 30 and the cover body 91. That is, the permanent magnet 45, housing 30, cover body 91, and angle sensor 96 are arranged in this order in a direction orthogonal to the axis L. The angle sensor 96 detects the orientation and magnitude of the magnetic field components (magnetic flux density components) in two mutually orthogonal directions contained in the magnetic field passing through the angle sensor 96. In this reference example, the angle sensor 96 outputs an electrical signal corresponding to the orientation and magnitude of the magnetic field component in the X direction and an electrical signal corresponding to the orientation and magnitude of the magnetic field component in the Y direction. The rotation angle of the permanent magnet 45 can be obtained based on the electrical signals output by the angle sensor 96.

[0056] Angle sensor 96 outputs an electrical signal corresponding to the rotation angle of permanent magnet 45. Figure 5 The image shows an example of the electrical signal output by the angle sensor 96. Figure 5 In the graph, the solid line represents the output of the magnetic field component in the X direction, and the dashed line represents the output of the magnetic field component in the Y direction. For example, when the rotation angle of the permanent magnet 45 is 360 × n [degrees] (where n is an integer) ( Figure 3 The magnetic field component in the X direction is at its maximum (positive value), and the magnetic field component in the Y direction is zero. When the rotation angle of the permanent magnet 45 is 360×n+90 [degrees] ( Figure 4 When the permanent magnet 45 rotates by an angle of 360×n+180 degrees, the magnetic field component in the X direction is zero, and the magnetic field component in the Y direction is at its maximum (positive). When the permanent magnet 45 rotates by an angle of 360×n+270 degrees, the magnetic field component in the X direction is zero, and the magnetic field component in the Y direction is at its minimum (negative). The sign (positive or negative) of the magnetic field component value indicates the orientation of the magnetic field component, and the absolute value of the magnetic field component indicates its magnitude.

[0057] In the electric valve 1, the central axis of each of the valve port 14, the cage 20, the valve core support component 25, the housing 30, the magnetic rotor 41, the connecting component 42, the rotor shaft 43, the permanent magnet 45, the output shaft 57, the guide component 60, the drive shaft 65, the valve core 70, and the stator 81 is aligned with the axis L.

[0058] Next, the operation of electric valve 1 will be explained.

[0059] In the electric valve 1, current flows into the coil of the stator 81, causing the magnetic rotor 41 to rotate in one direction. The rotation of the magnetic rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. The drive shaft 65 moves downwards due to the threaded feed action between itself and the guide member 60. This pushes the valve core 70 downwards, reducing the opening area of ​​the valve port 14.

[0060] In the electric valve 1, current flows into the coil of the stator 81, causing the magnetic rotor 41 to rotate in the opposite direction. The rotation of the magnetic rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. The drive shaft 65 moves upward by the threaded feed action between the drive shaft 65 and the guide member 60. The valve core 70 is pushed upward by the valve opening spring 75, increasing the opening area of ​​the valve port 14.

[0061] The electric valve 1 has a cylindrical housing 30, a magnetic rotor 41 disposed inside the housing 30, a permanent magnet 45 coaxially disposed inside the housing 30 and the magnetic rotor 41, and a stator unit 80 having a stator 81 disposed outside the housing 30. The permanent magnet 45 has a circular shape and rotates together with the magnetic rotor 41. A first portion 45n, divided by a diameter K, is provided with an N pole, and a second portion 45s is provided with an S pole. The magnetization direction of the permanent magnet 45 is orthogonal to the axis L. The stator unit 80 has an angle sensor 96 for detecting the rotation angle of the permanent magnet 45. Moreover, the angle sensor 96 and the housing 30 are arranged in a direction orthogonal to the axis L.

[0062] Therefore, the magnetic field lines F of the permanent magnet 45 extend from the outer peripheral surface of the first part 45n and enter the outer peripheral surface of the second part 45s in a direction orthogonal to the axis L (rotation axis). Thus, in the electric valve, the magnetic field strength in the space located to the side of the housing 30 (i.e., the space relative to the housing 30 in a direction orthogonal to the axis L) is stronger, allowing for accurate detection of the rotation angle of the magnetic rotor 41 (permanent magnet 45) using the angle sensor 96 disposed to the side of the housing 30. Furthermore, by disposing the angle sensor 96 to the side of the housing 30, the height dimension of the electric valve 1 can be reduced.

[0063] Furthermore, the angle sensor 96 detects the orientation and magnitude of the magnetic field component in the X direction (first direction) and the orientation and magnitude of the magnetic field component in the Y direction (second direction). In this way, the rotation angle of the magnetic rotor 41 can be detected more accurately using the magnetic field components in the X and Y directions.

[0064] (First Embodiment)

[0065] Next, refer to Figures 6-9 The electric valve 1A according to the first embodiment of the present invention will be described.

[0066] Figure 6 This is a longitudinal sectional view of the electric valve according to the first embodiment of the present invention. Figure 7 (A) is Figure 6 A three-dimensional diagram of the magnetic rotor of the electric valve. Figure 7 (B) is Figure 6 A front view of the magnetic rotor of the electric valve. Figure 8 (A) is Figure 6 A top view of the magnetic rotor of the electric valve. Figure 8 (B) is Figure 6 A bottom view of the magnetic rotor of the electric valve. Figure 9 express Figure 7 The variations of the magnetic rotor involved are examples of magnetic rotors. Figure 9(A) is a 3D diagram. Figure 9 (B) is the front view.

[0067] Electric valve 1A is the same as electric valve 1 described above, except for (1) and (2) below.

[0068] (1) The electric valve 1A does not have a permanent magnet 45 and a magnetic shielding component 46.

[0069] (2) Electric valve 1A replaces magnetic rotor 41 and has magnetic rotor 41A.

[0070] Therefore, in the description of electric valve 1A, the same symbols are used for structures identical to those of electric valve 1, and detailed descriptions are omitted.

[0071] The magnetic rotor 41A has a cylindrical shape. The outer diameter of the magnetic rotor 41A is smaller than the inner diameter of the housing 30. The magnetic rotor 41A is configured to rotate inside the housing 30. A circular plate-shaped connecting member 42 engages with the upper end of the magnetic rotor 41A. The connecting member 42 seals the upper end of the magnetic rotor 41A. The rotor shaft 43 passes through the center of the connecting member 42. The upper end of the rotor shaft 43 is supported by a bearing member 44 to rotate. The magnetic rotor 41A is connected to the rotor shaft 43 via the connecting member 42. The rotor shaft 43 rotates together with the magnetic rotor 41A. The rotation axis of the magnetic rotor 41A is aligned with the axis L. The magnetic rotor 41A does not move along the axis L.

[0072] The magnetic rotor 41A integrally comprises a first magnetic pole portion 41a, a magnetic buffer portion 41b, and a second magnetic pole portion 41c connected sequentially along the axis L.

[0073] The first magnetic pole portion 41a has multiple N poles and multiple S poles. The multiple N poles and multiple S poles extend along the axis L. The multiple N poles and multiple S poles are alternately arranged circumferentially on the outer peripheral surface of the first magnetic pole portion 41a. The first magnetic pole portion 41a is arranged with the stator 81 in a direction orthogonal to the axis L, separated by the outer casing 30. The first magnetic pole portion 41a is a driving part that generates rotational force together with the stator 81.

[0074] A magnetic buffer portion 41b is disposed between the first magnetic pole portion 41a and the second magnetic pole portion 41c. The magnetic buffer portion 41b is not magnetized. The length of the magnetic buffer portion 41b along its axis L is set such that the magnetic field generated by the first magnetic pole portion 41a does not affect the length of the magnetic field generated by the second magnetic pole portion 41c. This length is set based on measured values ​​of the strength of the magnetic fields generated by the first and second magnetic pole portions 41a and 41c, simulation results, etc. The magnetic buffer portion 41b suppresses the mutual influence between the magnetic fields generated by the first magnetic pole portion 41a and the second magnetic pole portion 41c.

[0075] The second magnetic pole portion 41c is disposed at the upper end of the magnetic rotor 41A. The second magnetic pole portion 41c has a circular shape when viewed from the axis L. The second magnetic pole portion 41c has one N pole and one S pole. An N pole is disposed on one side of the second magnetic pole portion 41c (the first part 41n), which is divided by the diameter K, and an S pole is disposed on the other side (the second part 41s). The N pole and the S pole are in a direction orthogonal to the axis L and to the diameter K. Figure 8 (A) is relative to each other in the X direction. The second magnetic pole part 41c is a detection unit that generates the magnetic field detected by the angle sensor 96.

[0076] The second magnetic pole portion 41c is magnetized in a direction orthogonal to the axis L and to the diameter K. Therefore, as Figure 8 As shown in (A), the magnetic field lines of the second magnetic pole portion 41c extend from the outer peripheral surface of the first portion 41n and enter the outer peripheral surface of the second portion 41s in a direction orthogonal to the axis L (parallel to the XY plane). Furthermore, the second magnetic pole portion 41c may be provided with at least one N pole and at least one S pole arranged alternately in the circumferential direction. For example, the second magnetic pole portion 41c may have two N poles and two S poles arranged alternately in the circumferential direction. The second magnetic pole portion 41c and the angle sensor 96 are arranged in a direction orthogonal to the axis L, separated by the housing 30 and the cover body 91. Figure 6 In the diagram, dashed lines represent the boundaries between the first magnetic pole portion 41a and the magnetic buffer portion 41b, as well as the boundaries between the magnetic buffer portion 41b and the second magnetic pole portion 41c in the magnetic rotor 41A.

[0077] Alternatively, the second magnetic pole portion 41c can also be magnetized in the direction of the axis L. For example... Figure 9 (A) Figure 9 As shown in (B), in the second magnetic pole portion 41c, a first portion 41n serving as the N pole and a second portion 41s serving as the S pole are alternately arranged circumferentially. The first portion 41n and the second portion 41s are magnetized in the direction of the axis L; therefore, in the second magnetic pole portion 41c, there are S poles aligned with the first portion 41n in the direction of the axis L and N poles aligned with the second portion 41s in the direction of the axis L. Figure 9 As shown in (B), the magnetic field lines F of the second magnetic pole portion 41c extend from the upper end face of the first portion 41n and enter the upper end face of the second portion 41s along the axis L direction (parallel to the XZ plane). In the structure in which the second magnetic pole portion 41c is magnetized in the axis L direction, similar to the electric valve in Patent Document 1, the angle sensor 96 is disposed above the upper end of the housing 30. That is, the second magnetic pole portion 41c and the angle sensor 96 are arranged in the axis L direction through the housing 30 and the cover body 91 (upper wall portion 91b).

[0078] In the electric valve 1A, the magnetic lines of force of the second magnetic pole portion 41c of the magnetic rotor 41A extend from the outer peripheral surface of the first portion 41n and enter the outer peripheral surface of the second portion 41s in a direction orthogonal to the axis L. Furthermore, a magnetic buffer portion 41b is provided between the first magnetic pole portion 41a and the second magnetic pole portion 41c. The magnetic buffer portion 41b suppresses the interaction between the magnetic field generated by the first magnetic pole portion 41a and the magnetic field generated by the second magnetic pole portion 41c. Therefore, in the electric valve 1A, the magnetic field strength in the space located to the side of the housing 30 (i.e., the space relative to the housing 30 in a direction orthogonal to the axis L) is relatively strong, and the rotation angle of the magnetic rotor 41A (second magnetic pole portion 41c) can be accurately detected by the angle sensor 96 disposed to the side of the housing 30. Furthermore, by disposing the angle sensor 96 to the side of the housing 30, the height dimension of the electric valve 1A can be reduced.

[0079] The first magnetic pole portion 41a is a bonded magnet made of a first synthetic resin containing a first magnetic material. The second magnetic pole portion 41c is a bonded magnet made of a second synthetic resin containing a second magnetic material. The first magnetic pole portion 41a and the second magnetic pole portion 41c can be isotropic or anisotropic magnets. The magnetic buffer portion 41b is made of the first synthetic resin. In this embodiment, the first synthetic resin is a polyphenylene sulfide resin (PPS resin) mixed with ferrite powder as the first magnetic material. The second synthetic resin is, for example, a PPS resin mixed with neodymium powder. PPS resin is an adhesive (bonding material). The type of the first magnetic material (ferrite) is different from the type of the second magnetic material (neodymium), that is, the first synthetic resin constituting the first magnetic pole portion 41a is different from the second synthetic resin constituting the second magnetic pole portion 41c. The first magnetic material (ferrite), the second magnetic material (neodymium), and the adhesive (PPS resin) are examples, but other materials may also be used. In addition, different types of adhesives may be used in the first synthetic resin and the second synthetic resin.

[0080] Alternatively, the first magnetic material and the second magnetic material may be of the same type (e.g., neodymium), but the mixing ratio of the first magnetic material in the first synthetic resin may differ from the mixing ratio of the second magnetic material in the second synthetic resin. In this case, the first synthetic resin constituting the first magnetic pole portion 41a may also differ from the second synthetic resin constituting the second magnetic pole portion 41c.

[0081] The magnetic rotor 41A is a molded body formed by integrally molding the first magnetic pole part 41a, the magnetic buffer part 41b, and the second magnetic pole part 41c through two-color molding.

[0082] Here is an example of a method for manufacturing the magnetic rotor 41A. (1) A first synthetic resin is injected into a cavity formed by a general mold and a primary side mold to form a cylindrical primary side component. The primary side component includes portions corresponding to the first magnetic pole portion 41a and the magnetic buffer portion 41b. (2) A second synthetic resin is injected into a cavity formed by a general mold holding the primary side component and a secondary side mold to form a cylindrical secondary side component. Thus, the primary side component and the secondary side component are integrated. The secondary side component only includes a portion corresponding to the second magnetic pole portion 41c. (3) The portion in the primary side component corresponding to the first magnetic pole portion 41a is magnetized to form multiple N poles and multiple S poles. The portion in the primary side component corresponding to the magnetic buffer portion 41b is not magnetized. (4) The secondary side component is magnetized to form one N pole and one S pole. The magnetic rotor 41A is manufactured in this way.

[0083] Alternatively, the magnetic buffer portion 41b can also be made of a second synthetic resin. An example of the manufacturing method in this case will be described. (1) A first synthetic resin is injected into a cavity formed by a general mold and a primary side mold to form a cylindrical primary side component. The primary side component only includes the portion corresponding to the first magnetic pole portion 41a. (2) A second synthetic resin is injected into a cavity formed by a general mold and a secondary side mold on which the primary side component is placed to form a cylindrical secondary side component. Thus, the primary side component and the secondary side component are integrated. The secondary side component includes the portion corresponding to the magnetic buffer portion 41b and the second magnetic pole portion 41c. (3) The primary side component is magnetized to form multiple N poles and multiple S poles. (4) The portion in the secondary side component corresponding to the second magnetic pole portion 41c is magnetized to form one N pole and one S pole. The portion in the secondary side component corresponding to the magnetic buffer portion 41b is not magnetized. The magnetic rotor 41A is manufactured in this way.

[0084] Alternatively, the magnetic buffer portion 41b may also be made of metal. The metal constituting the magnetic buffer portion 41b is, for example, a soft magnetic material with high permeability, such as silicon iron. An example of the manufacturing method in this case will be described. (1) A ring-shaped metal component corresponding to the magnetic buffer portion 41b is placed in a cavity formed by a general-purpose mold and a primary-side mold, and a first synthetic resin is injected into the cavity to form a cylindrical primary-side component. The primary-side component includes portions corresponding to the first magnetic pole portion 41a and the magnetic buffer portion 41b. (2) A second synthetic resin is injected into the cavity formed by the general-purpose mold holding the primary-side component and the secondary-side mold to form a cylindrical secondary-side component. Thus, the primary-side component and the secondary-side component are integrated. The secondary-side component only includes a portion corresponding to the second magnetic pole portion 41c. (3) The portion in the primary-side component corresponding to the first magnetic pole portion 41a is magnetized to form multiple N poles and multiple S poles. The portion in the primary-side component corresponding to the magnetic buffer portion 41b is not magnetized. (4) The secondary side components are magnetized to form an N pole and an S pole. The magnetic rotor 41A is manufactured in this way.

[0085] Alternatively, after forming the first magnetic pole portion 41a, the magnetic buffer portion 41b, and the second magnetic pole portion 41c respectively, they can be joined together by infrared welding, ultrasonic welding, or bonding with adhesive to produce a magnetic rotor 41A.

[0086] In this embodiment, the first magnetic pole portion 41a and the second magnetic pole portion 41c are bonded magnets, but the present invention is not limited to this configuration. For example, one of the first magnetic pole portion 41a and the second magnetic pole portion 41c may be made of a synthetic resin containing magnetic material, and the other may be made of a magnetizable ceramic material or a metal material, with the magnetic buffer portion 41b made of the synthetic resin. For example, the first magnetic pole portion 41a and the magnetic buffer portion 41b may be made of a first synthetic resin, and the second magnetic pole portion 41c may be made of a sintered metal body with sintered neodymium powder. In this case, the magnetic rotor 41A is a molded body integrally formed by insert molding of the first magnetic pole portion 41a, the magnetic buffer portion 41b, and the second magnetic pole portion 41c. An example of a manufacturing method in this case will be described. (1) Sinter neodymium powder to make a cylindrical sintered metal body. The sintered metal body only includes the portion corresponding to the second magnetic pole portion 41c. (2) Magnetize the sintered metal body to form an N pole and an S pole. (3) A sintered metal body is placed in a cavity formed by a mold, and a first synthetic resin is injected into the cavity to form a cylindrical resin component. The resin component includes portions corresponding to the first magnetic pole portion 41a and the magnetic buffer portion 41b. Thus, the sintered metal body and the resin component are integrated. (4) The portion of the resin component corresponding to the first magnetic pole portion 41a is magnetized to form multiple N poles and multiple S poles. The portion of the resin component corresponding to the magnetic buffer portion 41b is not magnetized. The magnetic rotor 41A is thus manufactured.

[0087] As explained above, the electric valve 1A of this embodiment has a cylindrical housing 30 and a magnetic rotor 41A disposed inside the housing 30, based on a stator unit 80 having a stator 81 disposed outside the housing 30. The magnetic rotor 41A integrally has a first magnetic pole portion 41a and a second magnetic pole portion 41c arranged in the axial direction L. The first magnetic pole portion 41a is provided with a plurality of N poles and a plurality of S poles arranged alternately in the circumferential direction. The second magnetic pole portion 41c is provided with at least one N pole and at least one S pole arranged alternately in the circumferential direction. The stator unit 80 has an angle sensor 96 for detecting the rotation angle of the second magnetic pole portion 41c. Moreover, the material constituting the first magnetic pole portion 41a is different from the material constituting the second magnetic pole portion 41c. Thus, when only one of the first magnetic pole portion 41a and the second magnetic pole portion 41c requires a larger magnetic force, the first magnetic pole portion 41a and the second magnetic pole portion 41c can be constructed with materials corresponding to the required magnetic force, respectively. Therefore, it is possible to reduce assembly time and material costs associated with the magnetic rotor 41A.

[0088] Furthermore, the magnetic rotor 41A integrally comprises a first magnetic pole portion 41a, a magnetic buffer portion 41b, and a second magnetic pole portion 41c connected sequentially along the axis L. Moreover, the magnetic buffer portion 41b is an unmagnetized portion. In this way, the interaction between the magnetic field generated by the first magnetic pole portion 41a and the magnetic field generated by the second magnetic pole portion 41c can be suppressed.

[0089] Furthermore, the length of the axis L of the magnetic buffer section 41b is such that the magnetic field generated by the first magnetic pole section 41a does not affect the magnetic field generated by the second magnetic pole section 41c. In this way, the magnetic field generated by the first magnetic pole section 41a can be suppressed from affecting the magnetic field generated by the second magnetic pole section 41c, and the rotation angle of the magnetic rotor 41A (second magnetic pole section 41c) can be accurately detected by the angle sensor 96.

[0090] Furthermore, the magnetization direction of the second magnetic pole portion 41c is orthogonal to the axis L. Moreover, the angle sensor 96 and the housing 30 are arranged in a direction orthogonal to the axis L. In this way, the magnetic field lines F of the second magnetic pole portion 41c extend from the outer peripheral surface of the first portion 41n and enter the outer peripheral surface of the second portion 41s along a direction orthogonal to the axis L. Therefore, in the electric valve 1A, the magnetic field strength in the space located to the side of the housing 30 (i.e., the space relative to the housing 30 in a direction orthogonal to the axis L) is stronger, allowing the angle sensor 96, disposed to the side of the housing 30, to accurately detect the rotation angle of the magnetic rotor 41A (the second magnetic pole portion 41c). Furthermore, by disposing the angle sensor 96 to the side of the housing 30, the height dimension of the electric valve 1A can be reduced.

[0091] Furthermore, the first magnetic pole portion 41a is made of a first synthetic resin containing a first magnetic material. The second magnetic pole portion 41c is made of a second synthetic resin containing a second magnetic material. The magnetic buffer portion 41b is made of the first synthetic resin, the second synthetic resin, or a metal. The type of the first magnetic material is different from the type of the second magnetic material, or the type of the first magnetic material is the same as the type of the second magnetic material, but the mixing ratio of the first magnetic material in the first synthetic resin is different from the mixing ratio of the second magnetic material in the second synthetic resin. In this way, by using relatively inexpensive bonded magnets to constitute the first magnetic pole portion 41a and the second magnetic pole portion 41c, the material cost of the magnetic rotor 41A can be reduced. In addition, the magnetic properties of the first magnetic pole portion 41a and the second magnetic pole portion 41c can be adjusted relatively easily by changing the type or mixing ratio of the magnetic material.

[0092] Furthermore, the magnetic rotor 41A is a molded body in which the first magnetic pole portion 41a, the magnetic buffer portion 41b, and the second magnetic pole portion 41c are integrally formed by two-color molding. In this way, the first magnetic pole portion 41a, the magnetic buffer portion 41b, and the second magnetic pole portion 41c are integrated in the manufacturing process of the magnetic rotor 41A. Therefore, compared with the structure in which the first magnetic pole portion 41a, the magnetic buffer portion 41b, and the second magnetic pole portion 41c are formed separately, the assembly time can be reduced.

[0093] Furthermore, one of the first magnetic pole portion 41a and the second magnetic pole portion 41c is made of a synthetic resin containing magnetic material, while the other is made of a magnetizable ceramic or metallic material, and the magnetic buffer portion 41b can be made of the synthetic resin. In this case, the magnetic rotor 41A can be a molded body in which the first magnetic pole portion 41a, the magnetic buffer portion 41b, and the second magnetic pole portion 41c are integrally formed by insert molding. In this way, the assembly time of the magnetic rotor 41A can be reduced, and ceramic magnets (ferrite magnets, etc.) or metallic magnets (rare earth magnets, etc.) with stronger magnetic force than bonded magnets can be used.

[0094] In this embodiment, the magnetic rotor 41A integrally comprises a first magnetic pole portion 41a and a second magnetic pole portion 41c, which are arranged along the axis L, sandwiching a magnetic buffer portion 41b. Alternatively, in the magnetic rotor 41A, the magnetic buffer portion 41b may be omitted, and the first magnetic pole portion 41a and the second magnetic pole portion 41c may be directly connected.

[0095] (Second Reference Example)

[0096] The following is for reference Figure 10 , Figure 11 The electric valve involved in the second reference example will be described.

[0097] Figure 10 , Figure 11 This is a longitudinal sectional view of the electric valve involved in the second reference example. Figure 10 An electric valve that represents the state where the opening area of ​​the valve port is at its minimum. Figure 11 An electric valve that represents the state where the valve port opening area is at its maximum.

[0098] like Figure 10 , Figure 11 As shown, the electric valve 2 involved in this reference example has a valve body 110, a retainer 120, a guide bushing 125, a housing 130 as a housing, a drive mechanism 140, a valve core 170, and a stator unit 180.

[0099] The valve body 110 has a cuboid shape. The valve body 110 has a valve chamber 113 and a valve port 114 connected to the valve chamber 113. The valve body 110 has a first passage 117 and a second passage 118. One end of the first passage 117 is connected to the valve chamber 113, and the other end of the first passage 117 opens on the left side 110a of the valve body 110. One end of the second passage 118 is connected to the valve chamber 113 via the valve port 114, and the other end of the second passage 118 opens on the right side 110b of the valve body 110. The valve body 110 has a mounting hole 119. The mounting hole 119 opens on the upper surface 110c of the valve body 110. An internal thread is formed on the inner circumferential surface of the mounting hole 119. The valve chamber 113 opens on the bottom surface 119a of the mounting hole 119.

[0100] The retainer 120 has a cylindrical shape. An external thread is formed on the lower part of the outer circumferential surface of the retainer 120. The external thread of the retainer 120 engages with the internal thread of the mounting hole 119 of the valve body 110. The retainer 120 is mounted to the valve body 110 via a threaded structure.

[0101] The guide bushing 125 has a first cylindrical portion 126 and a second cylindrical portion 127. The outer diameter of the second cylindrical portion 127 is smaller than the outer diameter of the first cylindrical portion 126. The second cylindrical portion 127 is coaxially connected to the upper end of the first cylindrical portion 126. An external thread 127a is formed on the outer peripheral surface of the second cylindrical portion 127. The first cylindrical portion 126 is pressed into the fitting hole 120a of the retainer 120.

[0102] The housing 130 has a cylindrical shape. The upper end of the housing 130 is sealed, and the lower end is open. The lower end of the housing 130 engages with the outer periphery of a ring-shaped engaging member 135. The upper part of a retainer 120 is disposed inside the engaging member 135. The inner periphery of the engaging member 135 engages with the retainer 120. The housing 130 is fixed to the valve body 110 via the engaging member 135 and the retainer 120.

[0103] The drive mechanism 140 moves the valve core 170 in the vertical direction (Z direction). The drive mechanism 140 has a magnetic rotor 141, a valve shaft holder 142, a valve shaft 143, and a permanent magnet 145.

[0104] The magnetic rotor 141 has a cylindrical shape. The outer diameter of the magnetic rotor 141 is smaller than the inner diameter of the housing 130. The magnetic rotor 141 is configured to rotate inside the housing 130. The magnetic rotor 141 has multiple N poles and multiple S poles. The multiple N poles and multiple S poles extend along the axis L. The multiple N poles and multiple S poles are alternately arranged circumferentially on the outer peripheral surface of the magnetic rotor 141. The axis L is parallel to the Z direction.

[0105] The valve shaft retainer 142 has a cylindrical shape with its upper end sealed. A support ring 144 is fixed to the upper end of the valve shaft retainer 142. The support ring 144 connects the magnetic rotor 141 to the valve shaft retainer 142. An internal thread 142a is formed on the inner circumferential surface of the valve shaft retainer 142. The internal thread 142a engages with the external thread 127a of the guide bushing 125.

[0106] The valve shaft 143 is cylindrical. The upper end 143a of the valve shaft 143 passes through the valve shaft retainer 142. A thrust nut 147 for preventing disengagement is installed at the upper end 143a of the valve shaft 143. The valve shaft 143 is disposed inside the guide bushing 125 and inside the retainer 120. The lower end of the valve shaft 143 is disposed in the valve chamber 113. A valve closing spring 148 is disposed between the valve shaft retainer 142 and the stepped portion 143b of the valve shaft 143. The valve closing spring 148 is a compression coil spring. The valve closing spring 148 pushes the valve shaft 143 downwards.

[0107] A permanent magnet 145 is disposed above the magnetic rotor 141 on the inner side of the housing 130. The permanent magnet 145 has an annular shape and a circular shape when viewed from the axis L. The permanent magnet 145 is fixed to the support ring 144 via a fastener 146. The permanent magnet 145 is coaxially arranged with the magnetic rotor 141 and rotates together with it. The permanent magnet 145 rotates about the rotation axis of the magnetic rotor 141. The rotation axis of the magnetic rotor 141 coincides with the axis L. The direction of the axis L is the direction of the rotation axis. The magnetic rotor 141 and the permanent magnet 145 move together with the rotation along the axis L.

[0108] The permanent magnet 145 has the same (including substantially the same) structure as the permanent magnet 45 of the electric valve 1. The permanent magnet 145 has one N pole and one S pole. An N pole is disposed in one portion (first portion) of the permanent magnet 145 divided by a diameter, and an S pole is disposed in the other portion (second portion). The N pole and the S pole are opposite each other in a direction orthogonal to the axis L and orthogonal to the diameter. The permanent magnet 145 is magnetized in a direction orthogonal to the axis L and orthogonal to the diameter. Therefore, the magnetic field lines of the permanent magnet 145 extend from the outer peripheral surface of the first portion and enter the outer peripheral surface of the second portion along a direction orthogonal to the axis L (parallel to the XY plane).

[0109] The valve core 170 has a generally conical shape with its apex pointing downwards. The valve core 170 is integrally connected to the lower end of the valve shaft 143. The valve core 170 and the valve port 114 are arranged opposite each other in the vertical direction. The valve core 170 infinitely (including substantially infinitely) changes the opening area of ​​the valve port 114 by moving forward and backward relative to it. The minimum area of ​​the valve port 114 can also be greater than zero (i.e., the valve port 114 is slightly open). Alternatively, the minimum area of ​​the valve port 114 can also be zero (i.e., the valve port 114 is fully closed).

[0110] The stator unit 180 includes a stator 81, a cover 90, and a substrate 95. The stator 81, cover 90, and substrate 95 are the same as (including substantially the same as) those of the electric valve 1, and therefore are marked with the same symbols and detailed descriptions are omitted.

[0111] The stator 81 is arranged in a direction orthogonal to the axis L, separated from the housing 130 by the magnetic rotor 141. The stator 81 and the magnetic rotor 141 together constitute a stepper motor.

[0112] Next, the operation of electric valve 2 will be explained.

[0113] In the electric valve 2, current flows into the coil of the stator 81, causing the magnetic rotor 141 to rotate in one direction. The valve shaft holder 142 rotates together with the magnetic rotor 141. The valve shaft holder 142 moves downwards due to the threaded feed action between the internal thread 142a of the valve shaft holder 142 and the external thread 127a of the guide bushing 125. The valve shaft 143 and the valve core 170 also move downwards together with the valve shaft holder 142, reducing the opening area of ​​the valve port 114. Figure 10 Electric valve 2 represents the state where the opening area of ​​valve port 114 is at its minimum.

[0114] In the electric valve 2, current flows into the coil of the stator 81, causing the magnetic rotor 141 to rotate in the opposite direction. The valve shaft retainer 142 rotates together with the magnetic rotor 141. The valve shaft retainer 142 moves upwards due to the threaded feed action between the internal thread 142a of the valve shaft retainer 142 and the external thread 127a of the guide bushing 125. The valve shaft 143 and the valve core 170 also move upwards together with the valve shaft retainer 142, increasing the opening area of ​​the valve port 114. Figure 11 Electric valve 2 indicates the state where the opening area of ​​valve port 114 is at its maximum.

[0115] The permanent magnet 145 rotates together with the magnetic rotor 141 and moves together with the magnetic rotor 141 in the direction of axis L. Figure 10 Move to the position shown Figure 11The angle sensor 96 and the permanent magnet 145 are always arranged in a direction orthogonal to the axis L, separated by the housing 130 and the cover body 91. In other words, the position of the angle sensor 96 in the direction of the axis L always overlaps with the position of the permanent magnet 145 in the direction of the axis L.

[0116] Electric valve 2 has the same (or substantially the same) function as electric valve 1.

[0117] Furthermore, in the electric valve 2, the permanent magnet 145 rotates and moves along the axis L. Moreover, the angle sensor 96 and the permanent magnet 145 are always arranged in a direction orthogonal to the axis L. In this way, compared to the case where the permanent magnet 145 moves away from the angle sensor 96 along the axis L, the rotation angle of the magnetic rotor 141 (permanent magnet 145) can be detected more accurately.

[0118] (Second Embodiment)

[0119] Next, refer to Figure 12 , Figure 13 The electric valve 2A according to the second embodiment of the present invention will be described.

[0120] Figure 12 , Figure 13 This is a longitudinal sectional view of the electric valve according to the second embodiment of the present invention. Figure 12 An electric valve that represents the state where the opening area of ​​the valve port is at its minimum. Figure 13 An electric valve that represents the state where the valve port opening area is at its maximum.

[0121] Except for (1) and (2) below, the electric valve 2A is the same as the electric valve 2 described above (including being substantially the same).

[0122] (1) The electric valve 2A does not have a permanent magnet 145 and a fastener 146.

[0123] (2) Electric valve 2A replaces magnetic rotor 141 and has magnetic rotor 141A.

[0124] Therefore, in the description of electric valve 2A, the same symbols are used for structures identical to those of electric valve 2, and detailed descriptions are omitted.

[0125] The magnetic rotor 141A has the same (or substantially the same) structure as the magnetic rotor 41A of the electric valve 1A. The magnetic rotor 141A has a cylindrical shape. The outer diameter of the magnetic rotor 141A is smaller than the inner diameter of the housing 130. The magnetic rotor 141A is configured to rotate inside the housing 130. The magnetic rotor 141A and the valve shaft holder 142 are connected by a support ring 144. The magnetic rotor 141A rotates together with the valve shaft holder 142.

[0126] The magnetic rotor 141A has a first magnetic pole portion 41a, a magnetic buffer portion 41b, and a second magnetic pole portion 41c connected sequentially along the axis L. The first magnetic pole portion 41a, the magnetic buffer portion 41b, and the second magnetic pole portion 41c are identical (or substantially identical) to those of the electric valve 1A, therefore they are labeled with the same symbols and detailed descriptions are omitted. Figure 12 , Figure 13 In the diagram, dashed lines represent the boundaries between the first magnetic pole portion 41a and the magnetic buffer portion 41b, as well as the boundaries between the magnetic buffer portion 41b and the second magnetic pole portion 41c in the magnetic rotor 141A.

[0127] The magnetic rotor 141A rotates and moves along the axis L. The second magnetic pole portion 41c of the magnetic rotor 141A moves from... Figure 12 Move to the position shown Figure 13 The angle sensor 96 and the second magnetic pole portion 41c are always arranged in a direction orthogonal to the axis L, separated by the housing 130 and the cover body 91. In other words, the position of the angle sensor 96 in the direction of the axis L always overlaps with the position of the second magnetic pole portion 41c in the direction of the axis L.

[0128] Electric valve 2A has the same (or substantially the same) function as electric valve 1A.

[0129] Furthermore, in the electric valve 2A, the magnetic rotor 141A rotates and moves along the axis L. Moreover, the angle sensor 96 and the second magnetic pole portion 41c are always arranged in a direction orthogonal to the axis L. In this way, compared to the case where the second magnetic pole portion 41c moves away from the angle sensor 96 along the axis L when the magnetic rotor 141A moves along the axis L, the rotation angle of the magnetic rotor 141A (second magnetic pole portion 41c) can be detected more accurately.

[0130] In this specification, terms such as "cylinder" and "cylindrical" that indicate shape are also used for components and parts of components that substantially have the shape described by that term. For example, "cylindrical-shaped component" includes both cylindrical-shaped components and components that are substantially cylindrical in shape.

[0131] The embodiments of the present invention have been described above, but the present invention is not limited to these examples. Any technical solutions made by those skilled in the art, such as adding or deleting constituent elements, making design changes, or appropriately combining features of the embodiments, are also included within the scope of the present invention, as long as they do not violate the spirit of the present invention.

[0132] Symbol Explanation

[0133] (First Reference Example, First Embodiment)

[0134] 1, 1A…electric valve, 10…valve body, 10a…left side, 10b…right side, 10c…upper surface, 13…valve chamber, 14…valve port, 17…first passage, 18…second passage, 19…mounting hole, 19a…bottom surface, 20…cage, 25…valve core support member, 25a…annular plane, 30…housing, 35…jointing member, 40…drive mechanism, 41…magnetic rotor, 41A…magnetic rotor, 41a…first magnetic pole portion, 41b…magnetic buffer portion, 41c…second magnetic pole portion, 41n…first part, 41s…second part, 42…connecting structural member, 43…rotor shaft, 44…bearing member, 45…permanent magnet, 45n…first part, 45s…second part, 46…magnetic shielding member, 50…planetary gear mechanism, 51…gear housing, 5 2…fixed gear ring, 53…sun gear, 54…planetary gear, 55…gear carrier, 56…output gear, 57…output shaft, 57a…slit, 60…guide member, 65…drive shaft, 66…cylindrical part, 67…flat part, 68…ball, 70…valve core, 71…valve stem, 72…valve part, 73…spring seat part, 73a…flange part, 74…ball seat part, 75…opening spring, 80…stator unit, 81…stator, 84…terminal, 90…cover, 91…cover body, 91a…first peripheral wall part, 91b…upper wall part, 91c…second peripheral wall part, 91d…cylindrical part, 91e…boss, 92…cover body, 93…connector, 94…substrate receiving space, 95…substrate, 95a…through hole, 96…angle sensor, F…magnetic line, K…diameter, L…axis.

[0135] (Second Reference Example, Second Embodiment)

[0136] 2, 2A…Electric valve, 110…Valve body, 110a…Left side face, 110b…Right side face, 110c…Upper surface, 113…Valve chamber, 114…Valve port, 117…First passage, 118…Second passage, 119…Mounting hole, 119a…Bottom surface, 120…Retainer, 120a…Matching hole, 125…Guide bushing, 126…First cylindrical part, 127…Second cylindrical part, 127a…External thread 130… Housing, 135… Connecting component, 140… Drive mechanism, 141… Magnetic rotor, 141A… Magnetic rotor, 142… Valve shaft retainer, 142a… Internal thread, 143… Valve shaft, 143a… Upper end, 143b… Stepped portion, 144… Support ring, 145… Permanent magnet, 146… Fixing component, 147… Thrust nut, 148… Closing valve spring, 170… Valve core, 180… Stator unit.

Claims

1. An electric valve comprising: a cylindrical housing, a magnetic rotor disposed inside the housing, and a stator unit having a stator disposed outside the housing, characterized in that, The magnetic rotor has a cylindrical shape. The magnetic rotor integrally comprises a first magnetic pole portion, a magnetic buffer portion, and a second magnetic pole portion arranged in the direction of the rotation axis of the magnetic rotor. The first magnetic pole portion is provided with multiple N poles and multiple S poles arranged alternately in the circumferential direction. The second magnetic pole portion is provided with at least one N pole and at least one S pole arranged alternately in the circumferential direction, and the second magnetic pole portion is a binary magnetized magnet with paired N and S poles. The magnetic buffer section is the unmagnetized portion. The stator unit has an angle sensor that detects the rotation angle of the second magnetic pole portion. The magnetization direction of the second magnetic pole portion is orthogonal to the rotation axis. The angle sensor and the housing are arranged in a direction orthogonal to the rotation axis. The first magnetic pole portion is composed of a first synthetic resin containing a first magnetic material. The second magnetic pole portion is composed of a second synthetic resin containing a second magnetic material. The magnetic buffer portion is composed of the first synthetic resin, the second synthetic resin, or metal. The first magnetic material is of a different type than the second magnetic material, or the first magnetic material is of the same type as the second magnetic material, but the mixing ratio of the first magnetic material in the first synthetic resin is different from the mixing ratio of the second magnetic material in the second synthetic resin. The magnetic rotor is a molded body in which the first magnetic pole portion, the magnetic buffer portion, and the second magnetic pole portion are integrally formed by two-color molding.

2. The electric valve according to claim 1, characterized in that... The length of the rotation axis of the magnetic buffer section is such that the magnetic field generated by the first magnetic pole section does not affect the magnetic field generated by the second magnetic pole section.

3. The electric valve according to claim 1, characterized in that... The magnetic rotor rotates and moves along the direction of the rotation axis. The angle sensor and the second magnetic pole portion are always arranged in a direction orthogonal to the rotation axis.

4. The electric valve according to claim 1, characterized in that, The electric valve has a planetary gear mechanism. A circular plate-shaped connecting member is arranged on the inner side of the magnetic rotor. The planetary gear mechanism has a sun gear, which is coaxially configured with and integrated with the connecting member. The rotor shaft passes through the center of the connecting component and the sun gear. The connecting component connects the second magnetic pole portion to the rotor shaft.

5. The electric valve according to claim 1, characterized in that, The electric valve has a valve shaft retainer that is rotatably screwed in. A support ring is disposed on the inner side of the magnetic rotor. The support ring connects the second magnetic pole portion to the valve shaft retainer.

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