Electric valve

Abstract

[Problem] To provide an electric valve which is capable of more accurately detecting the position of a valve element and is easy to assemble. [Solution] An electric valve 1 includes: a valve body 10; a can 30; a drive shaft 70; a planetary gear mechanism 60 which transmits the rotation of a rotor 51 to the drive shaft 70; a valve body 40 which is disposed in a valve chamber 13 of the valve body 10 and of which the vertical position changes according to the rotation of the drive shaft 70; and a magnetic sensor 85 disposed outside the can 30. The electric valve 1 also includes: a drive magnet 76 attached to the drive shaft 70 and rotating together with the drive shaft 70; and an annular driven magnet 77 surrounding the drive magnet 76. The driven magnet 77 rotates around the drive shaft 70 as the drive magnet 76 rotates. The magnetic sensor 85 detects the magnetism of the driven magnet 77.

Description

Electric valve

[0001] The present invention relates to a motor-operated valve.

[0002] Patent Document 1 discloses an example of a conventional motor-operated valve. The motor-operated valve in Patent Document 1 has a valve body, a valve element, a drive shaft, a guide member, a gear mechanism, and a stepping motor. The valve body has a valve port. The valve element is pushed away from the valve port by a valve-opening spring. The drive shaft has a male thread. The drive shaft is connected to the output shaft of the gear mechanism. The valve port, valve element, drive shaft, and output shaft are arranged on a straight line. The guide member has a female thread into which the male thread of the drive shaft is threaded.

[0003] The stepping motor has a rotor and a stator. The rotation of the rotor is reduced by a gear mechanism and transmitted from the output shaft to the drive shaft. When the drive shaft rotates, it moves due to the feed screw action. When the rotor rotates in a first direction, the drive shaft pushes the valve disc, bringing the valve disc closer to the valve orifice. When the rotor rotates in a second direction, the drive shaft moves away from the valve orifice, and the valve-opening spring pushes the valve disc, moving the valve disc away from the valve orifice.

[0004] Japanese Patent Application Laid-Open No. 2018-135908

[0005] The motor-operated valve of Patent Document 1 includes a permanent magnet and an angle sensor. The permanent magnet is attached coaxially to the output shaft and rotates together with the output shaft. The angle sensor outputs a signal corresponding to the rotation angle of the permanent magnet (output shaft). The rotation angle corresponds to the position of the valve disc.

[0006] The output shaft has a slit extending in the direction of the straight line. The end of the drive shaft is placed in the slit, connecting the output shaft and the drive shaft, so that rotation of the output shaft is transmitted to the drive shaft. The drive shaft is movable in the direction of the straight line relative to the output shaft.

[0007] However, there is a gap between the inner surface of the slit in the output shaft and the outer surface of the end of the drive shaft, so the rotation angle of the output shaft and the rotation angle of the drive shaft do not strictly match, and therefore the rotation angle obtained based on the signal from the angle sensor does not accurately correspond to the position of the valve disc.

[0008] By integrally connecting the drive shaft to the output shaft of the gear mechanism, the rotation angle of the output shaft and the rotation angle of the drive shaft are the same. However, the drive shaft and the gear mechanism essentially become a single component, and the installation work of the drive shaft and the installation work of the gear mechanism must be performed in parallel, making the assembly of the motor-operated valve difficult.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an easily assembled motor-operated valve that can detect the position of the valve element more accurately.

[0010] The motor-operated valve has a valve body having a valve chamber, a cylindrical case attached to the valve body, a magnet rotor arranged inside the case, a drive shaft arranged inside the case, a gear mechanism that transmits the rotation of the magnet rotor to the drive shaft, a valve body arranged in the valve chamber and whose position changes in accordance with the rotation of the drive shaft, and a magnetic sensor arranged outside the case, wherein the motor-operated valve has a drive magnet attached to the drive shaft and rotating together with the drive shaft, and a ring-shaped driven magnet surrounding the drive magnet, wherein the driven magnet rotates around the drive shaft as the drive magnet rotates, and the magnetic sensor detects the magnetism of the driven magnet.

[0011] The electric valve has a valve body having a valve chamber, a cylindrical case attached to the valve body, a magnet rotor arranged inside the case, a drive shaft arranged inside the case, a gear mechanism that transmits the rotation of the magnet rotor to the drive shaft, a valve body arranged in the valve chamber and whose position changes according to the rotation of the drive shaft, and a magnetic sensor arranged outside the case, and the electric valve has a drive magnet attached to the drive shaft and rotates together with the drive shaft, and a magnetic transmission member arranged between the drive magnet and the case and extending radially of the case, one end of the magnetic transmission member faces the drive magnet and the other end of the magnetic transmission member faces the inner surface of the case, and the magnetic sensor detects the magnetism of the magnetic transmission member.

[0012] In order to achieve the above object, one aspect of the present invention provides an electrically operated valve comprising: a valve body having a valve chamber, a cylindrical case attached to the valve body, a magnet rotor arranged inside the case, a drive shaft arranged inside the case, a gear mechanism that transmits the rotation of the magnet rotor to the drive shaft, a valve element arranged in the valve chamber and whose position changes in accordance with the rotation of the drive shaft, and a magnetic sensor arranged outside the case, wherein the electrically operated valve has a drive magnet that rotates around the axis of the drive shaft, and the drive magnet rotates together with the drive shaft or rotates when the position of the valve element changes; (i) the electrically operated valve has a driven magnet that rotates around the axis, and the driven magnet rotates in accordance with the rotation of the drive magnet, and the magnetic sensor detects the magnetism of the driven magnet, or (ii) the electrically operated valve has a magnetic transmission member, one end of the magnetic transmission member faces the drive magnet and the other end of the magnetic transmission member faces the inner surface of the case, and the magnetic sensor detects the magnetism of the magnetic transmission member.

[0013] In the present invention, it is preferable that the motor-operated valve has the driven magnet, the driven magnet has an annular shape, and the drive magnet is disposed inside the driven magnet.

[0014] In the present invention, it is preferable that the motor-operated valve has the driven magnet, and the driven magnet is spaced apart from the drive magnet in the axial direction.

[0015] In the present invention, it is preferable that the electric valve has a guide member with an internal thread that is fixed to the valve body, the drive shaft has an external thread that is threaded into the internal thread of the guide member, the valve body has a valve port facing the valve body, the valve body and the valve port are arranged coaxially with the axis, and when the drive shaft rotates, the drive shaft moves in the direction of the axis, and the position of the valve body changes in the direction of the axis in accordance with the movement of the drive shaft.

[0016] In the present invention, it is preferable that the drive magnet has a female thread, the valve body has a male thread that is screwed into the female thread of the drive magnet, and the drive magnet rotates when the position of the valve body changes in the direction of the axis.

[0017] In the present invention, it is preferable that the valve element is a rotary valve element that is attached to the drive shaft and rotates together with the drive shaft.

[0018] In the present invention, it is preferable that the motor-operated valve has a stator arranged outside the case and constituting a motor together with the magnet rotor, and a magnetic shielding member arranged between the stator and the magnetic sensor.

[0019] According to the present invention, the drive magnet rotates together with the drive shaft or rotates when the position of the valve disc changes. The driven magnet is magnetically coupled to the drive magnet and rotates about the axis of the drive shaft as the drive magnet rotates. This causes the rotation angle of the drive magnet to match the rotation angle of the driven magnet, allowing the magnetic sensor to output a signal more accurately corresponding to the rotation angle of the drive shaft or the position of the valve disc. This allows the position of the valve disc to be detected more accurately without integrating the drive shaft with the output shaft of the gear mechanism.

[0020] According to the present invention, the drive magnet rotates with the drive shaft or when the position of the valve disc changes. One end of the magnetic transmission member faces the drive magnet, and the other end faces the inner surface of the case. This allows the magnetic pole of the drive magnet that faces one end of the magnetic transmission member to appear at the other end, allowing the magnetic sensor to output a signal that more accurately corresponds to the rotation angle of the drive shaft or the position of the valve disc. This allows the position of the valve disc to be detected more accurately without integrating the drive shaft with the output shaft of the gear mechanism.

[0021] Therefore, the motor-operated valve is easy to assemble and the position of the valve element can be detected more accurately.

[0022] 1. A longitudinal sectional view of a motor-operated valve according to a first embodiment of the present invention. 2. A longitudinal sectional view of a valve body assembly of the motor-operated valve. 3. A longitudinal sectional view showing an enlarged view of the drive shaft of the motor-operated valve and its vicinity. 4. A sectional view taken along line IV-IV in FIG. 3. 5. A diagram explaining the magnetic pole arrangement of a drive magnet and a driven magnet of the motor-operated valve. 6. A longitudinal sectional view showing the configuration of a first modified example of the motor-operated valve of FIG. 1. 7. A longitudinal sectional view showing the configuration of a second modified example of the motor-operated valve of FIG. 1. 8. A sectional view taken along line IX-IX in FIG. 8. 9. A longitudinal sectional view of a motor-operated valve according to a third embodiment of the present invention. 10. A longitudinal sectional view showing an enlarged view of the drive shaft of the motor-operated valve of FIG. 10 and its vicinity. 11. A diagram explaining the magnetic pole arrangement of the drive magnet and the driven magnet of the motor-operated valve of FIG. 10. 12. A longitudinal sectional view of a motor-operated valve according to a fourth embodiment of the present invention. 13. A longitudinal sectional view showing an enlarged view of the drive shaft of the motor-operated valve of FIG. 13 and its vicinity.

[0023] First Embodiment A motor-operated valve according to a first embodiment of the present invention will now be described with reference to Figures 1 to 7. The motor-operated valve according to this embodiment is used, for example, to control the flow rate of refrigerant in an automotive air conditioner.

[0024] FIG. 1 is a longitudinal cross-sectional view of a motor-operated valve according to a first embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view of a valve body assembly of the motor-operated valve. FIG. 3 is an enlarged longitudinal cross-sectional view of the drive shaft of the motor-operated valve and its vicinity. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. In FIG. 4, the sub-board and magnetic sensor are indicated by dotted lines. FIG. 5 is a diagram illustrating the magnetic pole arrangement of the drive magnet and driven magnet of the motor-operated valve. FIG. 5A is a plan view of the drive magnet and driven magnet of the motor-operated valve. FIG. 5B is a cross-sectional view taken along line VB-VB in FIG. 5A. FIG. 6 is a longitudinal cross-sectional view showing the configuration of a first modified example of the motor-operated valve of FIG. 1. FIG. 7 is a longitudinal cross-sectional view showing the configuration of a second modified example of the motor-operated valve of FIG. 1. FIGS. 1 to 3, 5B, 6, and 7 are cross-sectional views taken along axis L. FIG. 4 is a cross-sectional view perpendicular to axis L.

[0025] As shown in FIG. 1 , the motor-operated valve 1 according to the first embodiment includes a valve body assembly 5 and a stator unit 8 .

[0026] The valve body assembly 5 includes a valve body 10 , a can 30 , a valve body 40 , a drive mechanism 50 , a drive magnet 76 , and a driven magnet 77 .

[0027] The valve body 10 includes a main body member 11 , a holder 20 , and a valve body support member 25 .

[0028] The main body member 11 has a rectangular parallelepiped shape. The main body member 11 is made of a metal such as an aluminum alloy. The main body member 11 has a valve chamber 13, a valve port 14, a valve seat 15, a first passage 17, and a second passage 18. The valve port 14 is connected to the valve chamber 13. The valve port 14 is surrounded by the valve seat 15 in the valve chamber 13. The first passage 17 extends from the right side surface 11a of the main body member 11 to the valve port 14. The first passage 17 is connected to the valve chamber 13 via the valve port 14. The second passage 18 extends from the left side surface 11b of the main body member 11 to the valve chamber 13. The main body member 11 has a mounting hole 19. The mounting hole 19 is located on the top surface 11c of the main body member 11. An internal thread is provided on the inner circumferential surface of the mounting hole 19. The mounting hole 19 is connected to the valve chamber 13. The main body member 11 has an annular flat surface 19a. The annular flat surface 19a is disposed at a connection point between the mounting hole 19 in the main body member 11 and the valve chamber 13.

[0029] The holder 20 has a first member 21, a second member 22, and a connecting member 23. The first member 21 and the second member 22 are made of, for example, synthetic resin or a non-magnetic metal such as an aluminum alloy or brass. In this specification, "non-magnetic" refers to the property of not being magnetized even when placed in a magnetic field (including the property of not being substantially magnetized).

[0030] The first member 21 integrally includes a base 21a and a support portion 21b. The base 21a and the support portion 21b each have a cylindrical shape. The outer diameter of the support portion 21b is smaller than the outer diameter of the base 21a. The support portion 21b is coaxially connected to the upper end of the base 21a. The first member 21 has a support surface 21f. The support surface 21f is an upwardly facing annular plane. The support surface 21f is located at the connection point between the base 21a and the support portion 21b in the first member 21. A male thread is provided on the outer peripheral surface of the base 21a. The male thread of the base 21a is threaded into the female thread of the mounting hole 19 of the main body member 11. The holder 20 is attached to the main body member 11 using a screw structure.

[0031] The second member 22 has a cylindrical shape. The inner diameter of the second member 22 is smaller than the inner diameter of the support portion 21b of the first member 21. The second member 22 is coaxially joined to the upper end of the support portion 21b. The first member 21 and the second member 22 form an annular groove 24 whose bottom surface is the outer peripheral surface of the support portion 21b.

[0032] The connecting member 23 has a circular ring shape. The base 21a of the first member 21 is disposed inside the connecting member 23, and the inner peripheral edge of the connecting member 23 is joined to the base 21a.

[0033] The valve disc support member 25 has a cylindrical shape. The valve disc support member 25 is disposed in the mounting hole 19 between the main body member 11 and the first member 21. The lower part of the valve disc support member 25 is press-fitted into the valve chamber 13. The outer peripheral surface of the valve disc support member 25 is provided with a downward-facing annular flat surface 25a. The annular flat surface 25a is in contact with the annular flat surface 19a of the main body member 11.

[0034] The can 30 has a cylindrical shape. The upper end of the can 30 is closed and the lower end is open. The lower end of the can 30 is joined to the outer periphery of the connecting member 23. The can 30 is fixed to the main body member 11 via the connecting member 23 and the holder 20. The can 30 is a case that is attached to the valve main body 10. The can 30 is made of a metal such as non-magnetic stainless steel.

[0035] The valve body 40 has a stem 41 , a valve portion 42 , a spring receiving portion 43 , and a ball receiving portion 44 .

[0036] The stem 41 has a cylindrical shape and is disposed inside the valve body support member 25. The stem 41 is supported by the valve body support member 25 so as to be movable in the up and down direction (the direction of the axis L).

[0037] The valve portion 42 has an annular shape. The valve portion 42 is formed integrally with the stem 41 and is disposed at the lower end of the stem 41. The valve portion 42 protrudes radially outward from the outer circumferential surface of the stem 41. The valve portion 42 faces the valve port 14 in the up-down direction.

[0038] The spring bearing portion 43 has a main body portion 43a and a flange portion 43b. The main body portion 43a has a cylindrical shape. The outer diameter of the main body portion 43a is the same as the outer diameter of the stem 41. The main body portion 43a is coaxially joined to the upper end of the stem 41. The flange portion 43b has an annular shape. The flange portion 43b is formed integrally with the main body portion 43a and is disposed at the upper end of the main body portion 43a. The flange portion 43b protrudes radially outward from the outer peripheral surface of the main body portion 43a.

[0039] The ball receiving portion 44 has a circular flat plate portion 44a and a protruding portion 44b connected to the lower surface of the flat plate portion 44a. A conical recess is provided on the upper surface of the flat plate portion 44a. The protruding portion 44b is fitted into a hole provided in the main body portion 43a of the spring receiving portion 43. The ball receiving portion 44 is fixed to the spring receiving portion 43.

[0040] The opening area of ​​the valve orifice 14 changes continuously (including substantially continuously) as the valve portion 42 approaches or moves away from the valve orifice 14. When the valve portion 42 contacts the valve seat 15, the opening area of ​​the valve orifice 14 becomes 0 (fully closed state). Note that the minimum value of the opening area of ​​the valve orifice 14 may be greater than 0.

[0041] The drive mechanism 50 moves the valve element 40 in the up-down direction. The up-down movement of the valve element 40 is synonymous with the up-down change of the position of the valve element 40. The drive mechanism 50 has a rotor 51, a connecting plate 52, a rotor shaft 53, a bearing member 54, a planetary gear mechanism 60, a guide member 68, a drive shaft 70, a ball 74, and a valve-opening spring 75.

[0042] The rotor 51 has a cylindrical shape. The outer diameter of the rotor 51 is smaller than the inner diameter of the can 30. The rotor 51 is rotatably disposed inside the can 30. A connecting plate 52 is joined to the upper end of the rotor 51. The connecting plate 52 has a disk shape and closes the upper end of the rotor 51. The rotor shaft 53 passes through the center of the connecting plate 52. The rotor 51 is connected to the rotor shaft 53 via the connecting plate 52. A bearing member 54 rotatably supports the upper end of the rotor shaft 53. The rotor shaft 53 rotates together with the rotor 51.

[0043] The rotor 51 is a magnet rotor having a plurality of north poles and a plurality of south poles, which are arranged alternately in the circumferential direction on the outer circumferential surface of the rotor 51. The plurality of north poles and the plurality of south poles extend in the vertical direction.

[0044] The planetary gear mechanism 60 is a 3K type planetary gear mechanism. The planetary gear mechanism 60 may be, for example, a 2K-H type planetary gear mechanism. The planetary gear mechanism 60 is a reducer that reduces the rotation of the rotor 51. The motor-operated valve 1 may employ, instead of the planetary gear mechanism 60, another type of gear mechanism that functions as a reducer.

[0045] The planetary gear mechanism 60 is disposed inside the rotor 51. The planetary gear mechanism 60 has a gear case 61, a fixed ring gear 62, a sun gear 63, a plurality of planet gears 64, a carrier 65, an output gear 66, and an output shaft 67.

[0046] The gear case 61 has a cylindrical shape. The lower end of the gear case 61 is coaxially joined to the second member 22 of the holder 20. The fixed ring gear 62 is an internal gear. The fixed ring gear 62 is fixed to the upper end of the gear case 61.

[0047] The sun gear 63 is formed integrally with the connecting plate 52 and is disposed coaxially on the lower surface of the connecting plate 52. The rotor shaft 53 passes through the sun gear 63.

[0048] The carrier 65 has a disk shape. The rotor shaft 53 passes through the carrier 65. The carrier 65 is rotatable around the rotor shaft 53. The carrier 65 rotatably supports a plurality of planetary gears 64.

[0049] The output gear 66 has a cylindrical shape with a bottom. The output gear 66 is an internal gear. The upper portions of the multiple planetary gears 64 are arranged between the fixed ring gear 62 and the sun gear 63, and the lower portions of the multiple planetary gears 64 are arranged between the output gear 66 and the sun gear 63.

[0050] The output shaft 67 has a cylindrical shape. The upper part of the output shaft 67 is press-fitted into a hole provided in the bottom part of the output gear 66. The lower part of the output shaft 67 is provided with a slit 67a extending in the vertical direction. The output shaft 67 rotatably supports the lower end of the rotor shaft 53. The output shaft 67 is disposed inside the second member 22 of the holder 20. The output shaft 67 is rotatably supported by the second member 22. The output shaft 67 rotates together with the output gear 66.

[0051] The sun gear 63 rotates together with the rotor 51 and the connecting plate 52. The rotation of the sun gear 63 is reduced in speed by the fixed ring gear 62, the plurality of planetary gears 64, the carrier 65, and the output gear 66, and is transmitted to the output shaft 67.

[0052] The guide member 68 has a cylindrical shape. The guide member 68 is disposed inside the base portion 21 a of the first member 21 of the holder 20. The guide member 68 is fixed to the first member 21. The guide member 68 has a female thread 68 c. The female thread 68 c is disposed on the inner circumferential surface of the guide member 68.

[0053] The drive shaft 70 integrally includes a first portion 71, a second portion 72, and a third portion 73. The drive shaft 70 is made of, for example, a synthetic resin or a metal such as non-magnetic stainless steel.

[0054] The first portion 71 has a cylindrical shape. The first portion 71 has a male thread 71c. The male thread 71c is disposed on the outer peripheral surface of the first portion 71. The male thread 71c is threadedly engaged with the female thread 68c of the guide member 68. A conical recess is provided on the lower end surface of the first portion 71. A ball 74 is joined to the recess. The ball 74 slidably contacts the recess in the flat plate portion 44a of the ball receiver 44.

[0055] The second portion 72 has a rectangular prism shape. The lower end of the second portion 72 is connected to the upper end of the first portion 71.

[0056] The third portion 73 has a rectangular flat plate shape. The lower end of the third portion 73 is connected to the upper end of the second portion 72. The thickness of the third portion 73 is slightly smaller than the width of the slit 67a of the output shaft 67. The third portion 73 is disposed inside the slit 67a. The slit 67a and the third portion 73 allow the drive shaft 70 to move up and down relative to the output shaft 67 while transmitting the rotation of the output shaft 67 to the drive shaft 70.

[0057] The valve-opening spring 75 is disposed between the valve body support member 25 and the flange portion 43b of the valve body 40. The valve-opening spring 75 is a compression coil spring. The valve-opening spring 75 pushes the valve body 40 upward (in the direction away from the valve port 14).

[0058] The drive magnet 76 has an annular shape. The outer periphery of the drive magnet 76 is circular, and the inner periphery is rectangular. The outer diameter of the drive magnet 76 is slightly smaller than the inner diameter of the support portion 21b of the first member 21 of the holder 20. The drive magnet 76 is disposed inside the support portion 21b. The drive magnet 76 has semicircular arc portions 761 and 762 defined by a diameter. One semicircular arc portion 761 has one north pole and one south pole arranged in sequence from the inside to the outside in the radial direction, and the other semicircular arc portion 762 has one south pole and one north pole arranged in sequence from the inside to the outside in the radial direction. The second portion 72 of the drive shaft 70 is disposed inside the drive magnet 76. The drive magnet 76 is fixed to the drive shaft 70. The drive magnet 76 rotates together with the drive shaft 70. The drive magnet 76 rotates about the axis L. The drive magnet 76 is a permanent magnet.

[0059] The driven magnet 77 has an annular shape. The outer circumferential edge of the driven magnet 77 is circular, and the inner circumferential edge is circular. The outer diameter of the driven magnet 77 is slightly smaller than the inner diameter of the can 30. The inner diameter of the driven magnet 77 is slightly larger than the outer diameter of the support portion 21b of the first member 21 of the holder 20. The support portion 21b is disposed inside the driven magnet 77. The inner circumferential edge of the driven magnet 77 is disposed in the annular groove 24. The driven magnet 77 has semicircular arc portions 771 and 772 defined by a diameter. One north pole and one south pole are disposed in order from the inside to the outside in the radial direction in one semicircular arc portion 771, and one south pole and one north pole are disposed in order from the inside to the outside in the other semicircular arc portion 772. The lower surface of the driven magnet 77 is in slidable contact with the support surface 21f of the first member 21. The driven magnet 77 is disposed between the support portion 21b and the can 30 so as to be rotatable about the axis L. The driven magnet 77 is a permanent magnet.

[0060] The drive magnet 76 is disposed inside the driven magnet 77. The driven magnet 77 is aligned radially with the drive magnet 76 via the support portion 21b of the first member 21 of the holder 20, surrounding the drive magnet 76. This allows the vertical dimension of the motor-operated valve 1 to be reduced. The drive magnet 76 and the driven magnet 77 are magnetically coupled. The driven magnet 77 rotates about the axis L in conjunction with the rotation of the drive magnet 76. Note that the magnetic pole arrangement of the drive magnet 76 and the driven magnet 77 may be different from that shown in FIG. 5 , as long as the drive magnet 76 and the driven magnet 77 are magnetically coupled and the driven magnet 77 rotates about the axis L in conjunction with the rotation of the drive magnet 76. Furthermore, the drive magnet 76 is not limited to being annular.

[0061] The stator unit 8 includes a housing 81 , a stator 82 , a main board 83 , a sub-board 84 , and a magnetic sensor 85 .

[0062] The housing 81 is made of synthetic resin. The housing 81 has a peripheral wall portion 81a, an upper wall portion 81b, a case portion 81c, and a lid 81d. The peripheral wall portion 81a has a cylindrical shape. The upper wall portion 81b has a dome shape. The upper wall portion 81b is connected to the upper end of the peripheral wall portion 81a. The case portion 81c has a rectangular tubular shape. The case portion 81c extends laterally (in a direction perpendicular to the axis L) from the peripheral wall portion 81a. The lid 81d is joined to the tip of the case portion 81c. The space inside the case portion 81c is sealed.

[0063] The stator 82, together with the rotor 51, constitutes a stepping motor 88. The stator 82 is embedded in the peripheral wall portion 81a of the housing 81. The stator 82 is disposed outside the can 30. Note that the motor-operated valve 1 may have another type of motor instead of the stepping motor 88.

[0064] The main board 83 is disposed inside the case portion 81c along the vertical direction. The coil of the stator 82 is connected to the main board 83. A computer (not shown) is mounted on the main board 83.

[0065] The sub-board 84 is disposed inside the case portion 81c along the horizontal direction and is electrically connected to the main board 83. A magnetic sensor 85 is mounted on the sub-board 84.

[0066] The magnetic sensor 85 is a rotation angle sensor that outputs a signal (analog signal) corresponding to the rotation angle of the magnetic field. The magnetic sensor 85 is disposed near a partition wall 81e provided on the peripheral wall portion 81a of the housing 81. The magnetic sensor 85 faces the outer peripheral surface of the driven magnet 77 in the radial direction via the can 30 and the partition wall 81e. The magnetic sensor 85 is disposed outside the can 30, detects the magnetism of the driven magnet 77, and outputs a signal corresponding to the rotation angle of the driven magnet 77.

[0067] In this embodiment, the magnetic sensor 85 is disposed below the stator 82, and the distance between the stator 82 and the magnetic sensor 85 is short. Therefore, a magnetic shielding member may be disposed between the stator 82 and the magnetic sensor 85. The magnetic shielding member is, for example, a plate-shaped soft magnetic material with a relatively high magnetic permeability, such as silicon iron. The magnetic shielding member prevents the stator 82 from distorting the magnetic field near the magnetic sensor 85.

[0068] In the electric valve 1, the valve port 14, the first member 21 (base 21a, support portion 21b), the second member 22, the connecting member 23, the valve body support member 25, the can 30, the valve body 40, the rotor 51, the connecting plate 52, the rotor shaft 53, the output shaft 67, the guide member 68, the drive shaft 70 (first portion 71, second portion 72, third portion 73), the ball 74, the drive magnet 76, the driven magnet 77, and the stator 82 each have a central axis that coincides with the axis L.

[0069] Next, the operation of the motor-operated valve 1 will be described.

[0070] In the motor-operated valve 1, current is supplied to the stator 82 to rotate the rotor 51 in a first direction. The rotation of the rotor 51 is decelerated by the planetary gear mechanism 60 and transmitted to the drive shaft 70. As the drive shaft 70 rotates, the feed screw action between the male thread 71c of the drive shaft 70 and the female thread 68c of the guide member 68 causes the drive shaft 70 to move downward and approach the valve orifice 14. The drive shaft 70 presses the valve disc 40 downward, causing the valve disc 40 to move downward and reducing the opening area of ​​the valve orifice 14. When the valve disc 40 contacts the valve seat 15 and closes the valve orifice 14, the motor-operated valve 1 is in a fully closed state.

[0071] In the motor-operated valve 1, current is supplied to the stator 82 to rotate the rotor 51 in the second direction. The rotation of the rotor 51 is decelerated by the planetary gear mechanism 60 and transmitted to the drive shaft 70. When the drive shaft 70 rotates, the feed screw action between the male thread 71c of the drive shaft 70 and the female thread 68c of the guide member 68 causes the drive shaft 70 to move upward and away from the valve orifice 14. The valve disc 40 is pushed upward by the valve-opening spring 75, causing the valve disc 40 to move upward and increasing the opening area of ​​the valve orifice 14. When the valve disc 40 is farthest from the valve orifice 14, the motor-operated valve 1 is in a fully open state. When the motor-operated valve 1 is in a fully open state, the opening area of ​​the valve orifice 14 is at its largest.

[0072] A drive magnet 76 rotates together with the drive shaft 70 inside the holder 20. A driven magnet 77 arranged outside the holder 20 is magnetically coupled to the drive magnet 76, and the driven magnet 77 rotates as the drive magnet 76 rotates. The magnetic sensor 85 outputs a signal corresponding to the rotation angle of the driven magnet 77, and a computer detects the rotation angle based on this signal. The rotation angle of the driven magnet 77 matches the rotation angle of the drive shaft 70 and corresponds to the position of the valve disc 40.

[0073] As described above, the motor-operated valve 1 includes the valve body 10 having the valve chamber 13, the cylindrical can 30 attached to the valve body 10, the rotor 51 disposed inside the can 30, the drive shaft 70 disposed inside the can 30, the planetary gear mechanism 60 that transmits the rotation of the rotor 51 to the drive shaft 70, the valve element 40 disposed in the valve chamber 13 and whose position in the vertical direction changes in response to the rotation of the drive shaft 70, and the magnetic sensor 85 disposed outside the can 30. The motor-operated valve 1 includes a drive magnet 76 attached to the drive shaft 70 and rotating together with the drive shaft 70, and a ring-shaped driven magnet 77 surrounding the drive magnet 76. The driven magnet 77 rotates around the drive shaft 70 in response to the rotation of the drive magnet 76. The magnetic sensor 85 detects the magnetism of the driven magnet 77.

[0074] In the motor-operated valve 1, the drive magnet 76 rotates together with the drive shaft 70. The driven magnet 77 surrounds the drive magnet 76 and is magnetically coupled to the drive magnet 76, rotating about the drive shaft 70 (axis L) as the drive magnet 76 rotates. This causes the rotation angle of the drive shaft 70 and the rotation angle of the driven magnet 77 to coincide, allowing the magnetic sensor 85 to output a signal more accurately corresponding to the rotation angle of the drive shaft 70. This makes it possible to more accurately detect the rotation angle of the drive shaft 70 (i.e., the position of the valve disc 40) without integrating the drive shaft 70 with the output shaft 67 of the planetary gear mechanism 60. Therefore, the motor-operated valve 1 is easy to assemble and can more accurately detect the position of the valve disc 40.

[0075] The motor-operated valve 1 has a guide member 68 having a female thread 68c that is fixed to the valve body 10. The drive shaft 70 has a male thread 71c that is threaded into the female thread 68c. The valve body 10 has a valve port 14 that faces the valve element 40 in the vertical direction. The valve element 40, the valve port 14, and the drive shaft 70 are arranged coaxially with the axis L. When the drive shaft 70 rotates, the drive shaft 70 moves in the vertical direction (direction of the axis L). The position of the valve element 40 changes in the vertical direction in accordance with the movement of the drive shaft 70. The motor-operated valve 1 has a configuration in which the drive shaft 70 is arranged inside the holder 20 that is located within the can 30, and the rotation angle of the drive shaft 70 can be detected outside the can 30 using the magnetic coupling between the drive magnet 76 and the driven magnet 77.

[0076] The motor-operated valve 1 also has a stator 82 that is disposed outside the can 30 and that, together with the rotor 51, constitutes a stepping motor 88. The motor-operated valve 1 may also have a magnetic shielding member disposed between the stator 82 and the magnetic sensor 85. This prevents the stator 82 from distorting the magnetic field near the magnetic sensor 85, allowing for more accurate detection of the rotation angle of the drive shaft 70.

[0077] Fig. 6 shows a motor-operated valve 1A according to a first modified example of the motor-operated valve 1, and Fig. 7 shows a motor-operated valve 1B according to a second modified example of the motor-operated valve 1. In the following description, the same components as those in the motor-operated valve 1 (including substantially the same components) are designated by the same reference numerals, and detailed description thereof will be omitted.

[0078] The motor-operated valve 1A shown in FIG. 6 has the same configuration as the motor-operated valve 1, except that instead of the holder 20 and the driven magnet 77, a holder 20A and a driven magnet 77A are provided.

[0079] The holder 20A has a first member 21A, a second member 22A, and a connecting member 23. The first member 21A and the second member 22A are made of, for example, synthetic resin or a non-magnetic metal such as an aluminum alloy or brass.

[0080] The first member 21A integrally has a base portion 21a, a support portion 21b, and a connecting portion 21c. The base portion 21a and the support portion 21b have the same configuration as those of the motor-operated valve 1. The connecting portion 21c has a cylindrical shape. The outer diameter of the connecting portion 21c is larger than the outer diameter of the support portion 21b. The connecting portion 21c is coaxially connected to the upper end of the support portion 21b. A gear case 61 of the planetary gear mechanism 60 is coaxially joined to the connecting portion 21c. The first member 21A has an annular groove 24 whose bottom surface is the outer peripheral surface of the support portion 21b.

[0081] The second member 22A has a cylindrical shape. The second member 22A is disposed inside the connecting portion 21c of the first member 21A. The second member 22A is coaxially joined to the first member 21A. The output shaft 67 of the planetary gear mechanism 60 is disposed inside the second member 22A.

[0082] The driven magnet 77A has a semicircular arc-shaped first magnet member 77a and a semicircular arc-shaped second magnet member 77b. The first magnet member 77a and the second magnet member 77b are joined at their respective ends to form the annular driven magnet 77A. The first magnet member 77a and the second magnet member 77b are joined together, for example, with an adhesive. Alternatively, the first magnet member 77a and the second magnet member 77b may be joined together by their mutual magnetic force. The driven magnet 77A formed by joining the first magnet member 77a and the second magnet member 77b has the same configuration as the driven magnet 77 of the motor-operated valve 1.

[0083] The motor-operated valve 1B shown in Figure 7 has the same configuration as the motor-operated valve 1A, except that (1) the valve body support member 25, ball 74, valve-opening spring 75, and guide member 68 are omitted, and (2) the main body member 11, valve body 40, and drive shaft 70 are replaced with a main body member 11B, a ball valve body 40B, two seat members 47B, and a drive shaft 70B.

[0084] The main body member 11B has a rectangular parallelepiped shape. The main body member 11B is made of a metal such as an aluminum alloy. The main body member 11B has a valve chamber 13B, a first passage 17B, a second passage 18B, and a mounting hole 19. The first passage 17B extends from the right side surface 11a of the main body member 11B to the valve chamber 13B. The second passage 18B extends from the left side surface 11b of the main body member 11B to the valve chamber 13B. The mounting hole 19 is located on the top surface 11c of the main body member 11B. An internal thread is provided on the inner circumferential surface of the mounting hole 19. The mounting hole 19 is connected to the valve chamber 13B.

[0085] The ball valve element 40B is a rotary valve element. The ball valve element 40B has a connecting passage 46B that penetrates laterally. The seat member 47B has an annular shape. The seat member 47B is disposed in the valve chamber 13B, and the ball valve element 40B is disposed between the seat members 47B. The seat member 47B supports the ball valve element 40B so that it can rotate about the axis L. Rotation of the ball valve element 40B about the axis L is synonymous with a change in the position (rotational position) of the ball valve element 40B around the axis L.

[0086] The drive shaft 70B integrally includes a first portion 71B, a second portion 72, and a third portion 73. The second portion 72 and the third portion 73 have the same configuration as those of the motor-operated valve 1. The drive shaft 70B is made of, for example, synthetic resin or a metal such as non-magnetic stainless steel.

[0087] The first portion 71B has a cylindrical shape, and a lower end of the first portion 71B is coaxially joined to the ball valve body 40B.

[0088] The ball valve element 40B rotates together with the drive shaft 70B. Depending on the rotational position of the ball valve element 40B, the first passage 17B and the second passage 18B are connected by the connecting passage 46B, or the connection between the first passage 17B and the second passage 18B is cut off.

[0089] The motor-operated valves 1A and 1B also have the same effects as the motor-operated valve 1.

[0090] Second Embodiment A motor-operated valve according to a second embodiment of the present invention will be described below with reference to Figures 8 and 9. The motor-operated valve 2 according to this embodiment has the same configuration as the motor-operated valve 1, except that it has a drive magnet 76C, two magnetic transmission members 78C, and two magnetic sensors 85C instead of the drive magnet 76, driven magnet 77, and magnetic sensor 85. In the following description, components that are the same as those in the motor-operated valve 1 (including components that are substantially the same) are designated by the same reference numerals, and detailed description thereof will be omitted.

[0091] Fig. 8 is an enlarged cross-sectional view of the drive shaft and its vicinity of the motor-operated valve according to the second embodiment of the present invention, and Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 8.

[0092] The drive magnet 76C has an annular shape. The outer periphery of the drive magnet 76C is circular, and the inner periphery is rectangular. The outer diameter of the drive magnet 76C is slightly smaller than the inner diameter of the support portion 21b of the first member 21 of the holder 20. The drive magnet 76C is disposed inside the support portion 21b. The drive magnet 76C has multiple north poles and multiple south poles. The multiple north poles and multiple south poles are alternately disposed at equal angular intervals in the circumferential direction on the outer periphery of the rotor 51. The drive magnet 76C has, for example, six north poles and six south poles. The angle between adjacent north poles and south poles is 30 degrees. The second portion 72 of the drive shaft 70 is disposed inside the drive magnet 76C. The drive magnet 76C is fixed to the drive shaft 70. The drive magnet 76C rotates together with the drive shaft 70.

[0093] The magnetic transmission member 78C has a rectangular plate shape. The magnetic transmission member 78C is made of a soft magnetic material with relatively high magnetic permeability, such as silicon iron. The magnetic transmission member 78C is disposed inside the can 30. The magnetic transmission member 78C extends radially of the can 30. A first end E1 (one end) of the magnetic transmission member 78C is embedded in the support portion 21b of the first member 21 of the holder 20. The first end E1 of the magnetic transmission member 78C faces radially the outer circumferential surface of the drive magnet 76C. A second end E2 (the other end) of the magnetic transmission member 78C faces radially the inner circumferential surface of the can 30. The second end E2 has magnetic poles (north and south poles) that face the first end E1 of the drive magnet 76C. One of the two magnetic transmission members 78C is the first magnetic transmission member 78a, and the other is the second magnetic transmission member 78b. The magnetic transmission member 78C may have any shape as long as its first end E1 faces radially toward the drive magnet 76C and its second end E2 faces the portion of the inner surface of the can 30 that corresponds to the magnetic sensor 85C.

[0094] The magnetic sensor 85C is a sensor having a Hall element that outputs a signal (digital signal) corresponding to the direction of the magnetic field. The magnetic sensor 85C is disposed near a partition wall 81e provided on the peripheral wall portion 81a of the housing 81. The magnetic sensor 85C faces the second end E2 of the magnetic transmission member 78C in the radial direction via the can 30 and the partition wall 81e. The magnetic sensor 85C is disposed outside the can 30, detects the magnetism at the second end E2 of the magnetic transmission member 78C, and outputs a signal corresponding to the magnetic pole appearing at the second end E2. One of the two magnetic sensors 85C is the first magnetic sensor 85a, and the other is the second magnetic sensor 85b.

[0095] The first magnetic transmission member 78a and the first magnetic sensor 85a are disposed on a line M1 extending radially from the axis L. The second magnetic transmission member 78b and the second magnetic sensor 85b are disposed on a line M2 extending radially from the axis L. When the angle between adjacent north and south poles in the drive magnet 76C is α and N is a natural number, it is preferable that the angle θ between the lines M1 and M2 satisfy the following equation: θ = Nα + (α / 2)

[0096] In this embodiment, α = 30 degrees and θ = 45 degrees. By doing so, when the first magnetic transmission member 78a faces the center of the magnetic pole (north or south pole) of the drive magnet 76C, the second magnetic transmission member 78b faces the location between adjacent north and south poles on the outer circumferential surface of the drive magnet 76C. When the second magnetic transmission member 78b faces the center of the magnetic pole (north or south pole) of the drive magnet 76C, the first magnetic transmission member 78a faces the location between adjacent north and south poles on the outer circumferential surface of the drive magnet 76C. Therefore, the timing at which the signal from the first magnetic sensor 85a changes differs from the timing at which the signal from the second magnetic sensor 85b changes, and the rotation angle and rotation direction of the drive magnet 76C can be detected based on these signals.

[0097] The drive magnet 76C rotates together with the drive shaft 70 inside the holder 20. A magnetic transmission member 78C extending radially from the holder 20 transmits the magnetism of the drive magnet 76C from the first end E1 to the second end E2. As the drive magnet 76C rotates, the magnetic pole appearing at the second end E2 changes. The magnetic sensor 85C outputs a signal corresponding to the magnetic pole appearing at the second end E2, and a computer detects the rotation angle and direction of the drive magnet 76C based on this signal. The rotation angle of the drive magnet 76C matches the rotation angle of the drive shaft 70 and corresponds to the position of the valve disc 40.

[0098] As described above, the motor-operated valve 2 has the drive magnet 76C attached to the drive shaft 70 and rotating together with the drive shaft 70, and the magnetic transmission member 78C disposed between the drive magnet 76C and the can 30 and extending in the radial direction of the can 30. The first end E1 of the magnetic transmission member 78C faces the drive magnet 76C in the radial direction, and the second end E2 of the magnetic transmission member 78C faces the inner circumferential surface of the can 30. The magnetic sensor 85C detects the magnetism of the second end E2 of the magnetic transmission member 78C.

[0099] According to the motor-operated valve 2, the magnetic pole of the drive magnet 76C that faces the first end E1 of the magnetic transmission member 78C appears at the second end E2, and the magnetic sensor 85C outputs a signal that more accurately corresponds to the rotation angle of the drive magnet 76C (drive shaft 70). This makes it possible to more accurately detect the rotation angle of the drive shaft 70 (i.e., the position of the valve disc 40) without integrating the drive shaft 70 with the output shaft 67 of the planetary gear mechanism 60. Therefore, the motor-operated valve 2 is easy to assemble and can more accurately detect the position of the valve disc 40.

[0100] 10 to 12, a motor-operated valve according to a third embodiment of the present invention will be described. The motor-operated valve 3 according to this embodiment has the same configuration as the motor-operated valve 1, except that it has a holder 20D, a drive shaft 70D, a drive magnet 76D, and a driven magnet 77D instead of the holder 20, the drive shaft 70, the drive magnet 76, and the driven magnet 77. In the following description, components that are the same as those in the motor-operated valve 1 (including components that are substantially the same) are designated by the same reference numerals, and detailed description thereof will be omitted.

[0101] Fig. 10 is a longitudinal sectional view of a motor-operated valve according to a third embodiment of the present invention. Fig. 11 is an enlarged longitudinal sectional view of the drive shaft of the motor-operated valve of Fig. 10 and its vicinity. Fig. 12 is a diagram explaining the magnetic pole arrangement of the drive magnet and driven magnet of the motor-operated valve of Fig. 10. Fig. 12A is a plan view of the drive magnet. Fig. 12B is a plan view of the driven magnet. Fig. 12C is a longitudinal sectional view of the coaxially arranged drive magnet and driven magnet.

[0102] The holder 20D has a first member 21D, a second member 22D, and a connecting member 23. The first member 21D and the second member 22D are made of, for example, synthetic resin or a non-magnetic metal such as an aluminum alloy or brass.

[0103] The first member 21D has a first base portion 21h. The first base portion 21h has a cylindrical shape. The first member 21D has a support surface 21f. The support surface 21f is an annular plane facing upward. The support surface 21f is the upper end surface of the first base portion 21h. A male thread is provided on the outer peripheral surface of the first base portion 21h. The male thread of the first base portion 21h is screwed into the female thread of the mounting hole 19 of the main body member 11. The holder 20D is attached to the main body member 11 with a screw structure.

[0104] The second member 22D integrally includes a second base portion 22h and a support portion 22k. The second base portion 22h and the support portion 22k each have a cylindrical shape. The outer diameter of the support portion 22k is smaller than the outer diameter of the second base portion 22h. The support portion 22k is coaxially connected to the lower end of the second base portion 22h. The lower end of the support portion 22k is coaxially joined to the upper end of the first base portion 21h. The first member 21D and the second member 22D form an annular groove 24D, the bottom of which is formed by the outer peripheral surface of the support portion 22k. The output shaft 67 of the planetary gear mechanism 60 is disposed inside the second base portion 22h.

[0105] The second member 22D has a female screw 22c. The female screw 22c is disposed on the lower part of the inner circumferential surface of the second base portion 22h and on the inner circumferential surface of the support portion 22k. The second member 22D also functions as a guide member.

[0106] The drive shaft 70D integrally includes a first portion 71, a second portion 72D, and a third portion 73. The drive shaft 70D is made of, for example, synthetic resin or a metal such as non-magnetic stainless steel.

[0107] The first portion 71 has a cylindrical shape. The first portion 71 has a male thread 71c. The male thread 71c is disposed on the outer circumferential surface of the first portion 71. The male thread 71c is threadedly engaged with the female thread 22c of the second member 22D of the holder 20D.

[0108] The second portion 72D has a rectangular prism shape. The upper end of the second portion 72D is connected to the lower end of the first portion 71. A conical recess is provided on the lower end surface of the second portion 72D. A ball 74 is joined to the recess.

[0109] The third portion 73 has a rectangular flat plate shape. The lower end of the third portion 73 is connected to the upper end of the first portion 71. The third portion 73 is disposed inside the slit 67a of the output shaft 67.

[0110] The drive magnet 76D has an annular shape. The outer peripheral edge of the drive magnet 76D is circular, and the inner peripheral edge is rectangular. The outer diameter of the drive magnet 76D is slightly smaller than the inner diameter of the first base portion 21h of the first member 21D of the holder 20D. The drive magnet 76D is disposed inside the first base portion 21h. The drive magnet 76D has semicircular arc portions 761 and 762 defined by a diameter. The magnetic pole arrangement of the drive magnet 76D is the same as that of the drive magnet 76. The second portion 72D of the drive shaft 70D is disposed inside the drive magnet 76D. The drive magnet 76D is fixed to the drive shaft 70D. The drive magnet 76D rotates together with the drive shaft 70D. The drive magnet 76D rotates about the axis L. The drive magnet 76D is a permanent magnet.

[0111] The driven magnet 77D has an annular shape. The outer circumferential edge of the driven magnet 77D is circular, and the inner circumferential edge is circular. The outer diameter of the driven magnet 77D is slightly smaller than the inner diameter of the can 30. The inner diameter of the driven magnet 77D is slightly larger than the outer diameter of the support portion 22k of the second member 22D of the holder 20D. The support portion 22k is disposed inside the driven magnet 77D. The inner circumferential edge of the driven magnet 77D is disposed in the annular groove 24D. The driven magnet 77D has semicircular arc portions 771 and 772 defined by a diameter. The magnetic pole arrangement of the driven magnet 77D is the same as that of the driven magnet 77. The lower surface of the driven magnet 77D is in slidable contact with the support surface 21f of the first member 21D of the holder 20D. The driven magnet 77D is disposed between the support portion 22k and the can 30 so as to be rotatable about the axis L. The driven magnet 77D is a permanent magnet.

[0112] The driven magnet 77D is arranged coaxially with the drive magnet 76D. The driven magnet 77D is arranged above and spaced apart from the drive magnet 76D. This allows the radial dimension of the motor-operated valve 3 to be reduced. Furthermore, the drive magnet 76D of the motor-operated valve 3 has less dimensional constraints than the drive magnet 76 of the motor-operated valve 1. Therefore, in the motor-operated valve 3, the size of the drive magnet 76D can be made larger, and the magnetic force of the drive magnet 76D can be made stronger. When the drive magnet 76D and the driven magnet 77D are viewed from above and below, the outer periphery of the drive magnet 76D overlaps with the inner periphery of the driven magnet 77D. The drive magnet 76D and the driven magnet 77D are magnetically coupled. The driven magnet 77D rotates about the axis L as the drive magnet 76D rotates.

[0113] The motor-operated valve 3 has the same effect as the motor-operated valve 1.

[0114] (Fourth embodiment) A motor-operated valve according to a fourth embodiment of the present invention will be described below with reference to Figures 13 and 14. The motor-operated valve 4 according to this embodiment has the same configuration as the motor-operated valve 3, except that it has a valve body 40E, a drive shaft 70E, and a drive magnet 76E instead of the valve body 40, the drive shaft 70D, and the drive magnet 76D. In the following description, the same components as those in the motor-operated valves 1 and 3 (including substantially the same components) are designated by the same reference numerals, and detailed description thereof will be omitted.

[0115] Fig. 13 is a longitudinal sectional view of a motor-operated valve according to a fourth embodiment of the present invention, and Fig. 14 is an enlarged longitudinal sectional view of the drive shaft and its vicinity of the motor-operated valve of Fig. 13.

[0116] The valve body 40E has a stem 41, a valve portion 42, a spring receiving portion 43E, and a ball receiving portion 44.

[0117] The spring receiving portion 43E has a main body portion 43a and a threaded portion 43d. The main body portion 43a has a cylindrical shape. The outer diameter of the main body portion 43a is the same as the outer diameter of the stem 41. The main body portion 43a is coaxially joined to the upper end of the stem 41. The threaded portion 43d has a cylindrical shape. The outer diameter of the threaded portion 43d is larger than the outer diameter of the main body portion 43a. The threaded portion 43d is formed integrally with the main body portion 43a and is disposed at the upper end of the main body portion 43a. The threaded portion 43d has a male thread 43e. The male thread 43e is disposed on the outer peripheral surface of the threaded portion 43d. The ball receiving portion 44 is fixed to the threaded portion 43d.

[0118] The drive shaft 70E integrally includes a first portion 71 and a third portion 73. The lower end of the third portion 73 is connected to the upper end of the first portion 71. The drive shaft 70E has the same configuration as the drive shaft 70, except that the second portion 72 is omitted.

[0119] The drive magnet 76E has an annular shape. The outer circumferential edge of the drive magnet 76E is circular, and the inner circumferential edge is circular. The drive magnet 76E has a female thread 76e. The female thread 76e is disposed on the inner circumferential surface of the drive magnet 76E. The outer diameter of the drive magnet 76E is slightly smaller than the inner diameter of the first base portion 21h of the first member 21D of the holder 20D. The drive magnet 76E is disposed inside the first base portion 21h. A holding member 79E is disposed inside the first base portion 21h. The holding member 79E is fixed to the first base portion 21h. The lower surface of the drive magnet 76E is in slidable contact with the upper surface of the holding member 79E. The magnetic pole arrangement of the drive magnet 76E is the same as that of the drive magnet 76D. The threaded portion 43d of the valve body 40E is disposed inside the drive magnet 76E. The male thread 43e of the threaded portion 43d is threadedly engaged with the female thread 76e of the drive magnet 76E. The drive magnet 76E rotates about the axis L when the valve body 40E moves up and down. In other words, the drive magnet 76E rotates about the axis L when the position of the valve body 40E changes up and down. The drive magnet 76E is a permanent magnet.

[0120] The driven magnet 77D is arranged coaxially with the drive magnet 76E. The driven magnet 77D is arranged above and spaced apart from the drive magnet 76E. This allows the radial dimension of the motor-operated valve 4 to be reduced. When the drive magnet 76E and the driven magnet 77D are viewed from above and below, the outer circumferential edge of the drive magnet 76E overlaps with the inner circumferential edge of the driven magnet 77D. The drive magnet 76E and the driven magnet 77D are magnetically coupled. The driven magnet 77D rotates about the axis L as the drive magnet 76E rotates.

[0121] The motor-operated valve 4 has the same effect as the motor-operated valve 3.

[0122] In this specification, terms indicating shapes such as "cylinder," "column," and "rectangular parallelepiped" are also used to refer to members or portions of members that substantially have the shape of the term. For example, a "cylindrical member" includes both cylindrical members and substantially cylindrical members.

[0123] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the embodiments. Those skilled in the art may appropriately add, delete, or modify components of the above-described embodiments, or appropriately combine features of the embodiments, as long as they do not deviate from the spirit of the present invention.

[0124] 1...motor operated valve, 5...valve body assembly, 8...stator unit, 10...valve body, 11...body member, 11a...right side surface, 11b...left side surface, 11c...upper surface, 13...valve chamber, 14...valve port, 15...valve seat, 17...first passage, 18...second passage, 19...mounting hole, 19a...annular flat surface, 20...holder, 21...first member, 21a...base portion, 21b...support portion, 21c...connecting portion, 21f...support surface, 22...second member, 23...connecting member, 24...annular groove, 25...valve body support member, 25a...annular flat surface, 30...can, 40...valve body, 41...stem, 42...valve portion, 43...spring receiving portion, 43a...main body portion, 43b...flange portion, 44...ball receiving portion, 44a...flat plate portion, 44b...convex portion, 50...driving mechanism, 51...rotor, 52...connecting plate, 53...rotor rotor shaft, 54...bearing member, 60...planetary gear mechanism, 61...gear case, 62...fixed ring gear, 63...sun gear, 64...planetary gear, 65...carrier, 66...output gear, 67...output shaft, 67a...slit, 68...guide member, 68c...female thread, 70...drive shaft, 71...first portion, 71c...male thread, 72...second portion, 73...third portion, 74...ball, 75...open Valve spring, 76... drive magnet, 761... semicircular arc portion, 762... semicircular arc portion, 77... driven magnet, 771... semicircular arc portion, 772... semicircular arc portion, 81... housing, 81a... peripheral wall portion, 81b... upper wall portion, 81c... case portion, 81d... lid body, 81e... partition wall, 82... stator, 83... main board, 84... sub board, 85... magnetic sensor, 88... stepping motor DESCRIPTION OF SYMBOLS 1A...motor-operated valve, 20A...holder, 21A...first member, 22A...second member, 77A...driven magnet, 77a...first magnet member, 77b...second magnet member 1B...motor-operated valve, 11B...main body member, 13B...valve chamber, 17B...first passage, 18B...second passage, 40B...ball valve body, 46B...connecting passage, 47B...seat member, 70B...drive shaft, 71B...first part 2...motor-operated valve, 76C...drive magnet, 78C...magnetic transmission member, 78a...first magnetic transmission member, 78b...second magnetic transmission member, 85C...magnetic sensor, 85a...first magnetic sensor, 85b...second magnetic sensor, E1...first end, E2...second end 3...motor-operated valve, 20D...holder, 21D...first member, 21h...first base portion, 22D...second member, 22c...female thread, 22h...second base portion, 22k...support portion, 70D...drive shaft, 72D...second portion, 76D...drive magnet, 77D...follower magnet4... Motor-operated valve, 40E... Valve body, 43E... Spring receiving portion, 43d... Threaded portion, 43e... Male thread, 70E... Drive shaft, 76E... Drive magnet, 76e... Female thread, 79E... Holding member

Claims

1. An electrically-operated valve having a valve body having a valve chamber, a cylindrical case attached to the valve body, a magnet rotor arranged inside the case, a drive shaft arranged inside the case, a gear mechanism that transmits the rotation of the magnet rotor to the drive shaft, a valve body arranged in the valve chamber and whose position changes in accordance with the rotation of the drive shaft, and a magnetic sensor arranged outside the case, wherein the electrically-operated valve has a drive magnet that rotates around the axis of the drive shaft, and the drive magnet rotates together with the drive shaft or when the position of the valve body changes, and the electrically-operated valve has a driven magnet that rotates around the axis, and the driven magnet rotates in conjunction with the rotation of the drive magnet, and the magnetic sensor detects the magnetism of the driven magnet.

2. An electrically-operated valve having a valve body having a valve chamber, a cylindrical case attached to the valve body, a magnet rotor arranged inside the case, a drive shaft arranged inside the case, a gear mechanism for transmitting the rotation of the magnet rotor to the drive shaft, a valve body arranged in the valve chamber and changing its position in accordance with the rotation of the drive shaft, and a magnetic sensor arranged outside the case, wherein the electrically-operated valve has a drive magnet that rotates around the axis of the drive shaft, the drive magnet rotates together with the drive shaft or rotates when the position of the valve body changes, the electrically-operated valve has a magnetic transmission member, one end of the magnetic transmission member faces the drive magnet and the other end of the magnetic transmission member faces the inner surface of the case, and the magnetic sensor detects the magnetism of the magnetic transmission member.

3. The motor-operated valve according to claim 1, wherein the driven magnet has a ring shape, and the drive magnet is disposed inside the driven magnet.

4. The motor-operated valve according to claim 1, wherein said driven magnet is spaced apart from said driving magnet in the axial direction.

5. The motor-operated valve according to claim 1 or claim 2, wherein the motor-operated valve has a guide member having an internal thread that is fixed to the valve body, the drive shaft has a male thread that screws into the female thread of the guide member, the valve body has a valve port facing the valve element, the valve element and the valve port are arranged coaxially with the axis, the drive shaft moves in the direction of the axis when it rotates, and the position of the valve element changes in the direction of the axis in response to the movement of the drive shaft.

6. The motor-operated valve as described in claim 5, wherein the drive magnet has an internal thread, the valve body has an external thread that is screwed into the internal thread of the drive magnet, and the drive magnet rotates when the position of the valve body changes in the axial direction.

7. The motor-operated valve according to claim 1 or 2, wherein the valve body is a rotary valve body attached to the drive shaft and rotates together with the drive shaft.

8. The motor-operated valve according to claim 1 or 2, further comprising: a stator arranged outside the case and constituting a motor together with the magnet rotor; and a magnetic shielding member arranged between the stator and the magnetic sensor.

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