Motor-operated valve

Abstract

To provide a compact motor-operated valve in which a magnetic sensor can be arranged close to a can.SOLUTION: A motor-operated valve comprises a permanent magnet to be rotated together with a magnet rotor arranged inside a can, and a stator unit 50 comprising an inside space 74 in which the can is arranged. The stator unit 50 comprises a main board 90, a subsidiary board 100, and a magnetic sensor 110 provided on the subsidiary board 100, and for detecting a magnetic field generated from the permanent magnet. A housing 70 comprises a subsidiary board space 75 arranged adjacently to the inside space 74. A first end 100a of the subsidiary board 100 is connected to the main board 90 via a board terminal 101. A second end part 100b of the subsidiary board 100 is arranged in the subsidiary board space 75 and close to the inside space 74. The magnetic sensor 110 is arranged closer to the inside space 74 than the board terminal 101.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] An example of a conventional motor-operated valve is disclosed in Patent Document 1. The motor-operated valve in Patent Document 1 has a can, a magnet rotor, a permanent magnet, a stator, and a substrate. The can has a cylindrical shape with a closed upper end. The magnet rotor is arranged inside the can. The permanent magnet is arranged inside the can and above the magnet rotor. The permanent magnet rotates together with the magnet rotor. The stator is arranged coaxially with the magnet rotor on the outer circumferential surface of the can. A magnetic sensor that detects the rotation angle of the permanent magnet is provided on the substrate. By arranging the magnetic sensor near the can (permanent magnet), the accuracy of detecting the rotation angle can be improved. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-179133 Summary of the Invention [Problem to be solved by the invention]

[0004] In the motor-operated valve described above, the substrate is positioned above the can. The substrate is perpendicular to the rotation axis of the magnet rotor, and the magnetic sensor is positioned near the can. As a result, the motor-operated valve has a large shape in plan view and a large height. Furthermore, in a configuration in which the substrate is positioned to the side of the can and parallel to the rotation axis of the magnet rotor, a stator is located between the substrate and the can, making it impossible to position the magnetic sensor near the can.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a small motor-operated valve in which a magnetic sensor can be placed near the can. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the electric valve of the present invention is an electric valve having a valve body, a can joined to the valve body, a magnet rotor arranged inside the can, and a stator unit having an inner space in which the can is arranged, wherein the stator unit has a housing, a cylindrical stator accommodated in the housing, a flat main board, a flat sub-board, and a magnetic sensor provided on the sub-board, the housing has a sub-board space arranged adjacent to the inner space, a first end of the sub-board is connected to the main board via a board terminal, a second end of the sub-board is arranged near the inner space in the sub-board space, and the magnetic sensor is arranged closer to the inner space than the board terminal.

[0007] According to the present invention, the magnetic sensor is provided on the sub-board. The housing has a sub-board space arranged adjacent to the inner space in which the can is arranged. A first end of the sub-board is connected to the main board via a board terminal. A second end of the sub-board is arranged near the inner space in the sub-board space. On the sub-board, the second end is on the opposite side of the first end. The magnetic sensor is arranged closer to the inner space than the board terminal. This allows the magnetic sensor to be arranged closer to the can. By distributing and mounting electronic components on the main board and the sub-board, the main board can be made smaller. Therefore, the magnetic sensor can be arranged closer to the can and the motor-operated valve can be made smaller.

[0008] In the present invention, it is preferable that the housing has a partition wall that separates the inner space from the sub-board space. This prevents electrostatic discharge from the can to the sub-board, and prevents moisture that has entered the inner space from entering the sub-board space.

[0009] In the present invention, it is preferable that the housing has a press-fit groove into which the sub-board is press-fitted. In this way, the sub-board can be supported by the housing, and a separate member for supporting the sub-board can be omitted.

[0010] In the present invention, it is preferable that the inner surface of the press-fit groove is provided with a protrusion that elastically deforms when the sub-board is press-fitted into the press-fit groove. In this way, the protrusion presses the sub-board, thereby more reliably supporting the sub-board.

[0011] In the present invention, it is preferable that the magnetic sensor is disposed at the second end, which allows the magnetic sensor to be disposed closer to the can.

[0012] In the present invention, it is preferable that the main board is arranged parallel to the axial direction of the stator, and the sub-board is arranged perpendicular to the main board. By doing so, the motor-operated valve can be made even more compact.

[0013] In the present invention, it is preferable that the sub-substrate is arranged so as to be parallel to the axial direction. Among magnetic sensors having a surface-mount type package, magnetic sensors having a magnetic sensing surface on the upper surface of the package (a surface parallel to the substrate on which the magnetic sensor is mounted) are relatively inexpensive. Furthermore, by arranging the sub-substrate so as to be parallel to the axial direction of the stator, the upper surface of the package of the magnetic sensor provided on the sub-substrate can be arranged to face the outer peripheral surface of the can. This allows the use of a relatively inexpensive magnetic sensor, thereby reducing the component costs of the motor-operated valve.

[0014] In the present invention, it is preferable that the stator unit further includes a case joined to the housing, the case having a wall portion and a support pillar provided on the wall portion, the wall portion having a case opening connected to the sub-board space, the support pillar extending in a direction perpendicular to the axial direction and having a tip facing away from the inner space, the main board having a through hole, the sub-board being disposed across the case and the sub-board space, a sub-board support member attached to the sub-board, the sub-board support member having a cylindrical mounting portion, the support pillar being disposed inside the mounting portion and in the through hole, the tip of the support pillar having a diameter larger than the diameter of the through hole, and the mounting portion being sandwiched between the wall portion and the main board. In this manner, the mounting portion of the sub-board support member can be sandwiched between the wall portion of the case and the main board, thereby fixing the sub-board support member. Therefore, the sub-board can be reliably supported.

[0015] In the present invention, it is preferable that the motor-operated valve further includes a permanent magnet that rotates together with the magnet rotor, and the magnetic sensor is disposed so as to detect the magnetic field generated by the permanent magnet. In this way, the permanent magnet generates a stronger magnetic field than the magnet rotor, and the range of magnetic fields that can be detected by the magnetic sensor can be further expanded. As a result, restrictions on the placement of the magnetic sensor can be alleviated. [Effects of the Invention]

[0016] According to the present invention, the magnetic sensor can be disposed near the can, and the motor-operated valve can be made smaller. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view of a motor-operated valve according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of a stator unit included in the motor-operated valve of FIG. 1. [Figure 3] FIG. 2 is a perspective view of a main board included in the motor-operated valve of FIG. [Figure 4] 2 is a perspective view of a sub-board included in the motor-operated valve of FIG. 1. FIG. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 3 is a perspective view of the stator unit of FIG. 2 during assembly. [Figure 7] FIG. 7 is an enlarged perspective view of a part of FIG. 6. [Figure 8] 3 is another perspective view of the stator unit of FIG. 2 during assembly. FIG. [Figure 9] FIG. 9 is an enlarged perspective view of a part of FIG. 8. [Figure 10] FIG. 4 is a cross-sectional view of a motor-operated valve according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view of a stator unit included in the motor-operated valve of FIG. 10. [Figure 12] FIG. 11 is a perspective view of a main board of the motor-operated valve of FIG. [Figure 13] 11 is a perspective view of a sub-board and a sub-board support member of the motor-operated valve of FIG. 10. FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. [Figure 15] FIG. 10 is a cross-sectional view of a motor-operated valve according to a third embodiment of the present invention. [Figure 16] FIG. 16 is a cross-sectional view of a stator unit included in the motor-operated valve of FIG. 15. [Figure 17] 16 is a perspective view of a sub-board and a sub-board support member included in the motor-operated valve of FIG. 15. FIG. [Figure 18] 16 is another perspective view of the sub-board and the sub-board support member of the motor-operated valve of FIG. 15. FIG. [Figure 19] 16 is a diagram showing the positional relationship between the pole teeth of a stator and two magnetic sensors of the motor-operated valve of FIG. 15. FIG. [Figure 20] 16 is another diagram showing the positional relationship between the pole teeth of the stator and two magnetic sensors of the motor-operated valve of FIG. 15. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] (First Example) A motor-operated valve 1 according to a first embodiment of the present invention will be described below with reference to FIGS.

[0019] FIG. 1 is a cross-sectional view of a motor-operated valve according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a stator unit included in the motor-operated valve of FIG. 1. FIG. 3 is a perspective view of a main board included in the motor-operated valve of FIG. 1. FIG. 4 is a perspective view of a sub-board included in the motor-operated valve of FIG. 1. FIG. 5 is a cross-sectional view taken along line VV in FIG. 1. In FIG. 5, components arranged in the internal space of the stator unit are omitted. FIG. 6 is a perspective view of the stator unit of FIG. 2 during assembly. FIG. 7 is an enlarged perspective view of a portion of FIG. 6. FIGS. 6 and 7 show the state before the sub-board is placed in the sub-board space of the housing. FIG. 8 is another perspective view of the stator unit of FIG. 2 during assembly. FIG. 9 is an enlarged perspective view of a portion of FIG. 8. FIGS. 8 and 9 show the state after the sub-board has been placed in the sub-board space of the housing. In each drawing, the X direction indicated by arrow X is the left-right direction (horizontal direction), the Y direction indicated by arrow Y is the front-rear direction, and the Z direction indicated by arrow Z is the up-down direction. The arrow X with the letter "X" indicates the right direction, the arrow Y with the letter "Y" indicates the forward direction, and the arrow Z with the letter "Z" indicates the upward direction.

[0020] As shown in each figure, the motor-operated valve 1 includes a valve body 10, a can 20, a drive mechanism 30, a valve element 40, and a stator unit 50.

[0021] The valve body 10 is made of a metal such as an aluminum alloy. The valve body 10 has a main body portion 11, a cylindrical portion 12, and a flange portion 13. The main body portion 11 has a rectangular parallelepiped shape. The cylindrical portion 12 protrudes from the upper surface of the main body portion 11. The cylindrical portion 12 is attached to the main body portion 11 by a screw structure. The main body portion 11 is provided with a valve chamber 14 and flow paths 15 and 16. The flow path 15 is connected to the valve chamber 14. The flow path 16 is connected to the valve chamber 14 via a port 17. The flange portion 13 has an annular plate shape. The inner peripheral edge of the flange portion 13 is joined to the upper part of the cylindrical portion 12.

[0022] The can 20 is made of a metal such as stainless steel. The can 20 has a cylindrical shape with a closed upper end. The lower end of the can 20 is joined to the outer periphery of the flange 13.

[0023] The drive mechanism 30 moves the valve element 40 in the vertical direction (the direction of the axis L). The drive mechanism 30 has a magnet rotor 31, a valve stem holder 32, a guide bush 33, a valve stem , and a permanent magnet .

[0024] The magnet rotor 31 has a cylindrical shape. The outer diameter of the magnet rotor 31 is slightly smaller than the inner diameter of the can 20. The outer peripheral surface of the magnet rotor 31 is provided with a plurality of north poles and a plurality of south poles. The plurality of north poles and a plurality of south poles extend in the vertical direction and are arranged alternately at equal intervals in the circumferential direction. In this embodiment, the magnet rotor 31 has 12 north poles and 12 south poles.

[0025] The valve stem holder 32 has a cylindrical shape with a closed upper end. A support ring 35 is fixed to the top of the valve stem holder 32. The support ring 35 connects the magnet rotor 31 and the valve stem holder 32. A female thread 32c is provided on the inner circumferential surface of the valve stem holder 32.

[0026] The guide bush 33 integrally has a first cylindrical portion 33a and a second cylindrical portion 33b. The outer diameter of the second cylindrical portion 33b is smaller than the outer diameter of the first cylindrical portion 33a. The second cylindrical portion 33b is coaxially connected to the upper end of the first cylindrical portion 33a. An external thread 33c is provided on the outer peripheral surface of the second cylindrical portion 33b. The external thread 33c is threadedly engaged with the internal thread 32c of the valve stem holder 32. The first cylindrical portion 33a is press-fitted into a fitting hole 12a provided in the cylindrical portion 12 of the valve body 10. The guide bush 33 is connected to the valve body 10.

[0027] The valve stem 34 has a cylindrical shape. An upper portion 34a of the valve stem 34 passes through the valve stem holder 32. A push nut 36 is attached to the upper portion 34a of the valve stem 34 to prevent it from coming off. The valve stem 34 is inserted into the guide bush 33 and the cylindrical portion 12. The lower portion of the valve stem 34 is disposed in the valve chamber 14. The valve stem 34 has a step portion 34b which is an upward-facing annular flat surface. A valve-closing spring 37 is disposed between the valve stem holder 32 and the step portion 34b of the valve stem 34. The valve-closing spring 37 is a compression coil spring. The valve-closing spring 37 presses the valve stem 34 downward.

[0028] The permanent magnet 38 is disposed inside the can 20 and above the magnet rotor 31. The permanent magnet 38 has a circular flat plate shape. The permanent magnet 38 has one north pole and one south pole, and the north pole and south pole are disposed so as to face each other in the radial direction. The permanent magnet 38 is fixed to the support ring 35 via a fixture 39. The permanent magnet 38 rotates together with the magnet rotor 31.

[0029] The valve element 40 is integrally connected to the lower end of the valve shaft 34. The valve element 40 is disposed in the valve chamber 14. The valve element 40 is moved in the vertical direction by the drive mechanism 30. The movement of the valve element 40 opens and closes the port 17.

[0030] The stator unit 50 includes a stator 60 , a housing 70 , a case 80 , a main board 90 , a sub-board 100 , and a magnetic sensor 110 .

[0031] The stator 60 has a cylindrical shape. The stator 60 constitutes a stepping motor together with the magnet rotor 31. The stator 60 has an upper stator 61, a lower stator 62, and a mold 63 made of synthetic resin.

[0032] The upper-stage stator 61 is coaxially disposed above the lower-stage stator 62. The upper-stage stator 61 has a plurality of claw-pole-type pole teeth 61a, 61b arranged at equal intervals in the circumferential direction. The lower-stage stator 62 has a plurality of claw-pole-type pole teeth 62a, 62b arranged at equal intervals in the circumferential direction. In this embodiment, the upper-stage stator 61 has 12 pole teeth 61a and 12 pole teeth 61b. The lower-stage stator 62 has 12 pole teeth 62a and 12 pole teeth 62b. The tips of the pole teeth 61a, 62a face downward, and the tips of the pole teeth 61b, 62b face upward. The pole teeth 62a, 62b are disposed in the center between the adjacent pole teeth 61a and 61b when viewed from the direction of the axis L. When the upper stator 61 is energized, the pole teeth 61a and 61b become magnetic poles of opposite polarity. When the lower stator 62 is energized, the pole teeth 62a and 62b become magnetic poles of opposite polarity. A mold 63 is filled inside the upper stator 61 and the lower stator 62. The mold 63, together with the multiple pole teeth 61a, 61b, 62a, and 62b, forms the inner peripheral surface 60a of the stator 60. The diameter of the inner peripheral surface 60a of the stator 60 is the same as the diameter of the outer peripheral surface of the can 20. The mold 63 has a terminal support portion 64.

[0033] The terminal support portion 64 is disposed so as to extend laterally from the upper-stage stator 61 and the lower-stage stator 62. The terminal support portion 64 supports a plurality of terminals 65. The plurality of terminals 65 protrude laterally from the tip of the terminal support portion 64. The plurality of terminals 65 are connected to the coils of the upper-stage stator 61 and the lower-stage stator 62.

[0034] The housing 70 is made of synthetic resin. The housing 70 is formed by injection molding. The housing 70 accommodates the stator 60. The housing 70 may be integrally molded with the stator 60 (insert molding). The stator 60 and the housing 70 may be manufactured separately, and the stator 60 may be fitted inside the housing 70. The housing 70 integrally has a peripheral wall portion 71, a dome portion 72, and a cylindrical portion 73.

[0035] The peripheral wall portion 71 has a cylindrical shape. The stator 60 is disposed inside the peripheral wall portion 71. The dome portion 72 has a cylindrical shape with a closed upper end. The outer diameter of the dome portion 72 is smaller than the outer diameter of the peripheral wall portion 71. The dome portion 72 is connected to the upper end of the peripheral wall portion 71. The diameter of the inner peripheral surface 72a of the dome portion 72 (i.e., the inner peripheral surface of the housing 70) is the same as the diameter of the inner peripheral surface 60a of the stator 60. The inner peripheral surface 72a of the dome portion 72 is connected to the inner peripheral surface 60a of the stator 60. The inner peripheral surface 72a of the dome portion 72 and the inner peripheral surface 60a of the stator 60 form an inner space 74 of the stator unit 50. The can 20 is inserted into the inner space 74, and the stator 60 is disposed on the outer peripheral surface of the can 20. The tubular portion 73 has a cylindrical shape. The outer diameter of the cylindrical portion 73 is smaller than the outer diameter of the peripheral wall portion 71. The cylindrical portion 73 is connected to the lower end of the peripheral wall portion 71. The cylindrical portion 73 is arranged to surround the cylindrical portion 12 of the valve body 10. A ring-shaped sealing member 18 is arranged between the cylindrical portion 73 and the cylindrical portion 12. The sealing member 18 is made of an elastic material such as rubber. The sealing member 18 prevents moisture from entering the inner space 74.

[0036] The housing 70 has a sub-substrate space 75. The sub-substrate space 75 extends laterally and opens to a side surface of the housing 70. The sub-substrate space 75 is disposed adjacent to the inner space 74. A partition wall 76 is provided between the inner space 74 and the sub-substrate space 75. The partition wall 76 separates the inner space 74 from the sub-substrate space 75. As shown in FIG. 5 , the cross section of the partition wall 76 has an arc shape that follows the outer peripheral surface of the can 20.

[0037] Two press-fit grooves 77 are provided on the inner surface of the sub-substrate space 75. The press-fit grooves 77 extend laterally. The two press-fit grooves 77 are arranged to face each other in the front-to-rear direction. A plurality of protrusions 78 are provided on the inner surface of each press-fit groove 77. Some of the plurality of protrusions 78 (protrusion 78a in FIG. 7) are arranged to face each other in the up-down direction. Other of the plurality of protrusions 78 (protrusion 78b of one press-fit groove 77 in FIG. 7 and protrusion 78b of the other press-fit groove 77 not shown) are arranged to face each other in the front-to-rear direction. When the sub-substrate 100 is press-fitted into the press-fit groove 77, the protrusions 78 are compressed and elastically deformed. The plurality of protrusions 78 press the sub-substrate 100 press-fitted into the press-fit groove 77 in the up-down direction and the front-to-rear direction to support the sub-substrate 100.

[0038] The case 80 is made of synthetic resin. The case 80 is formed by injection molding. The case 80 is arranged to the side of the housing 70. The case 80 has a case main body 81, a lid body 82, and a connector 83. The case main body 81 has a rectangular parallelepiped box shape with one side open. The lid body 82 has a flat plate shape. The lid body 82 is arranged so as to cover the opening on the side of the case main body 81. The connector 83 has an elliptical cylindrical shape. The connector 83 is arranged so as to extend laterally (to the right) from the case main body 81. The case main body 81 and the connector 83 are integrally formed.

[0039] The case main body 81 has a side wall portion 84. The side wall portion 84 has a flat plate shape. The side wall portion 84 is arranged to face the lid body 82 in the horizontal direction. A rectangular case opening 84a is provided in the side wall portion 84. The case opening 84a is connected to the sub-board space 75 of the housing 70. The peripheral edge of the case opening 84a in the side wall portion 84 is joined to the housing 70. The case main body 81 also has a plurality of support pillars 85. The support pillars 85 have a cylindrical shape. The support pillars 85 extend horizontally (to the right) from the side wall portion 84. The tips 85a of the support pillars 85 are directed away from the inner space 74.

[0040] The main board 90 is a printed circuit board on which electronic components are mounted. The main board 90 has a flat plate shape. The main board 90 is housed in the case 80. The main board 90 is arranged so as to be parallel to the front-rear and up-down directions. A board connector 91 is provided on the surface of the main board 90 facing the inner space 74. A microcomputer (not shown) is mounted on the main board 90. This microcomputer functions as a computing device that processes the output signal of the magnetic sensor 110. The main board 90 has through holes 92 corresponding to each of the multiple support posts 85. The tips 85a of the support posts 85 are inserted into the through holes 92, and the tips 85a of the support posts 85 are deformed, for example, by infrared caulking, so that their diameters are larger than the diameter of the through holes 92. The main board 90 is supported by the support posts 85. Multiple terminals 65 of the stator 60 are connected to the main board 90.

[0041] The sub-board 100 is a printed circuit board on which electronic components are mounted. The sub-board 100 has a flat plate shape. The sub-board 100 is disposed in the sub-board space 75 of the housing 70. The sub-board 100 is disposed so as to be parallel to the horizontal and front-to-back directions. Opposing ends of the sub-board 100 in the front-to-back direction are press-fitted into press-fit grooves 77. The sub-board 100 is sandwiched between the protrusions 78 of the press-fit grooves 77 in the up-down and front-to-back directions. The sub-board 100 is disposed at a right angle (including a substantially right angle) to the main board 90. A first end 100a of the sub-board 100 is disposed near the main board 90. A second end 100b of the sub-board 100 is disposed near the partition wall 76 of the housing 70 (i.e., near the inner space 74). The first end 100a and the second end 100b face each other in the left-to-right direction. The sub-substrate 100 extends from near the main substrate 90 to near the inner space 74. The portion of the second end 100b facing the partition wall 76 has an arc shape that follows the partition wall 76. This allows the sub-substrate 100 to be placed closer to the partition wall 76, thereby shortening the distance between the magnetic sensor 110 and the magnet rotor 31 that are arranged on the sub-substrate 100.

[0042] A board terminal 101 is provided on a first end 100a of the sub-board 100. The board terminal 101 is connected to a board connector 91 of the main board 90. The sub-board 100 is connected to the main board 90 via the board terminal 101 and the board connector 91. It is also possible that the board terminal 101 is provided on the main board 90 and the board connector 91 is provided on the sub-board 100.

[0043] The magnetic sensor 110 is a rotation angle sensor. The magnetic sensor 110 has a surface-mount type package. The magnetic sensor 110 is provided at the second end 100b of the sub-substrate 100. The magnetic sensor 110 is disposed closer to the inner space 74 than the substrate terminal 101. The magnetic sensor 110 is disposed so as to laterally face the permanent magnet 38 with the can 20 and the partition wall 76 interposed therebetween. The magnetic sensor 110 detects the magnetic field generated by the permanent magnet 38 and outputs a signal corresponding to the rotation angle of the permanent magnet 38.

[0044] In the electric valve 1, the cylindrical portion 12 of the valve body 10, the port 17, the can 20, the magnet rotor 31, the valve shaft holder 32, the guide bush 33, the valve shaft 34, the valve body 40, the inner space 74 of the stator unit 50, the stator 60 (upper stator 61, lower stator 62), and the housing 70 (circumferential wall portion 71, cylindrical portion 73) each have their axes aligned with the axis L.

[0045] Next, the operation of the motor-operated valve 1 will be described.

[0046] In the motor-operated valve 1, current is applied to the upper stator 61 and the lower stator 62 so that the magnet rotor 31 rotates in one direction. The valve stem holder 32 rotates together with the magnet rotor 31. The valve stem holder 32 moves downward due to the screw feed action between the female thread 32c of the valve stem holder 32 and the male thread 33c of the guide bush 33. The valve stem 34 also moves downward together with the valve stem holder 32, and the valve element 40 closes the port 17 (valve closed state).

[0047] In the motor-operated valve 1, current is applied to the upper stator 61 and the lower stator 62 so that the magnet rotor 31 rotates in the other direction. The valve stem holder 32 rotates together with the magnet rotor 31. The valve stem holder 32 moves upward due to the screw feed action between the female thread 32c of the valve stem holder 32 and the male thread 33c of the guide bush 33. The valve stem 34 also moves upward together with the valve stem holder 32, and the valve element 40 opens the port 17 (open state).

[0048] The permanent magnet 38 rotates together with the magnet rotor 31 inside the can 20. The magnetic sensor 110 is disposed near the inner space 74 in which the can 20 is disposed, and outputs a signal corresponding to the rotation angle of the permanent magnet 38. The signal output by the magnetic sensor 110 is sent from the sub-board 100 to the main board 90 via the board terminal 101 and the board connector 91. A microcomputer provided on the main board 90 calculates the opening degree of the port 17, etc., based on the signal output by the magnetic sensor 110.

[0049] Next, a method for assembling the motor-operated valve 1 will be described.

[0050] The stator unit 50 is assembled. First, the stator 60 is placed in a housing mold, and the housing 70 is injection-molded so that the stator 60 and the housing 70 are integrated. The terminal components of the connector 83 are placed in a case mold, and the case body 81 and the connector 83 are injection-molded so that the case body 81, the connector 83, and the terminal components are integrated. The lid 82 is also injection-molded. As shown in FIG. 6, the side wall 84 of the case body 81 is joined to the housing 70 by ultrasonic welding or infrared welding, connecting the sub-substrate space 75 and the case opening 84a. As shown in FIG. 8, the sub-substrate 100 is inserted into the sub-substrate space 75 through the case opening 84a. At this time, both ends of the sub-substrate 100 facing in the front-rear direction are press-fitted into the press-fit grooves 77. As a result, the sub-substrate 100 is supported by the press-fit grooves 77. The sub-substrate 100 is positioned across the case 80 and the sub-substrate space 75. Then, while connecting the board terminals 101 of the sub-board 100 to the board connectors 91 of the main board 90, the tips 85a of the support posts 85 are inserted into the through holes 92 of the main board 90. The tips 85a of the support posts 85 are enlarged and deformed by infrared crimping. This allows the main board 90 to be supported by the support posts 85. The multiple terminals 65 of the stator 60 are soldered to the main board 90. The lid 82 is joined to the case body 81, completing the stator unit 50.

[0051] In a separate process from the stator unit 50, a valve body assembly is produced by combining the valve body 10, the can 20, the drive mechanism 30, and the valve element 40. Then, the can 20 is inserted into the inner space 74 of the stator unit 50, and the stator unit 50 is fixed to the valve body 10, completing the motor-operated valve 1.

[0052] As described above, the motor-operated valve 1 includes a valve body 10, a can 20 joined to the valve body 10, a magnet rotor 31 disposed inside the can 20, and a stator unit 50 having an inner space 74 in which the can 20 is disposed. The stator unit 50 includes a housing 70, a cylindrical stator 60 accommodated in the housing 70, a flat main board 90 disposed parallel to the vertical direction, a flat sub-board 100 disposed perpendicular to the main board 90, and a magnetic sensor 110 provided on the sub-board 100. The housing 70 includes a sub-board space 75 disposed adjacent to the inner space 74. A first end 100a of the sub-board 100 is connected to the main board 90 via a board terminal 101. A second end 100b of the sub-board 100 is disposed near the inner space 74 in the sub-board space 75. The magnetic sensor 110 is disposed at the second end 100b of the sub-board 100.

[0053] In the motor-operated valve 1, the sub-board 100 is disposed at a right angle to the main board 90, and the second end 100b of the sub-board 100 is disposed near the internal space 74. A magnetic sensor 110 is disposed at the second end 100b. This allows the magnetic sensor 110 to be disposed close to the can 20. Because the main board 90 is disposed parallel to the up-down direction, the shape of the motor-operated valve 1 in a plan view can be made small, and the height dimension can also be reduced. By distributing and mounting electronic components on the main board 90 and the sub-board 100, the main board 90 can be made smaller. This allows the magnetic sensor 110 to be disposed close to the can 20, and the motor-operated valve 1 can be made smaller.

[0054] In addition, the housing 70 has a partition wall 76 that separates the inner space 74 from the sub-board space 75. This prevents electrostatic discharge from the can 20 to the sub-board 100. It also prevents moisture that has entered the inner space 74 from entering the sub-board space 75.

[0055] Furthermore, the housing 70 has a press-fit groove 77 into which the sub-board 100 is press-fitted. In this way, the sub-board 100 can be supported by the housing 70, and a separate member for supporting the sub-board 100 can be omitted.

[0056] Furthermore, protrusions 78 are provided on the inner surface of the press-fit groove 77, which are elastically deformed when the sub-substrate 100 is press-fitted into the press-fit groove 77. In this way, the protrusions 78 press the sub-substrate 100, making it possible to support the sub-substrate 100 more reliably.

[0057] The motor-operated valve 1 also has a permanent magnet 38 that rotates together with the magnet rotor 31. The magnetic sensor 110 is disposed so as to detect the magnetic field generated by the permanent magnet 38. In this manner, the permanent magnet 38 generates a stronger magnetic field than the magnet rotor 31, and the range of magnetic fields that can be detected by the magnetic sensor 110 can be further expanded. As a result, restrictions on the placement of the magnetic sensor 110 can be alleviated.

[0058] Although the motor-operated valve 1 has a configuration in which the sub-substrate 100 is arranged perpendicular to the vertical direction, the sub-substrate 100 may also be arranged parallel to the vertical direction. Among magnetic sensors having a surface-mount type package, magnetic sensors having a magnetic sensing surface on the top surface of the package (a surface parallel to the substrate on which the magnetic sensor is mounted) are relatively inexpensive. Furthermore, by arranging the sub-substrate 100 parallel to the vertical direction, the top surface of the package of the magnetic sensor 110 provided on the sub-substrate 100 can be arranged to face the outer peripheral surface of the can 20. This allows the use of a relatively inexpensive magnetic sensor 110, thereby reducing the component costs of the motor-operated valve 1.

[0059] (Second Example) A motor-operated valve 1A according to a second embodiment of the present invention will be described below with reference to FIGS.

[0060] FIG. 10 is a cross-sectional view of a motor-operated valve according to a second embodiment of the present invention. FIG. 11 is a cross-sectional view of a stator unit included in the motor-operated valve of FIG. 10. FIG. 12 is a perspective view of a main board included in the motor-operated valve of FIG. 10. FIG. 13 is a perspective view of a sub-board and a sub-board support member included in the motor-operated valve of FIG. 10. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 10. In FIG. 14, components arranged in the inner space of the stator unit are not shown. In the following description, components that are the same as (including substantially the same as) those in the motor-operated valve 1 according to the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0061] As shown in each figure, the motor-operated valve 1A has a valve body 10, a can 20, a drive mechanism 30, a valve element 40, and a stator unit 50A. The stator unit 50A has a stator 60, a housing 70, a case 80, a main board 90, a sub-board 100, a sub-board support member 105, and a magnetic sensor 110. Note that the main board 90 is provided with through-holes 93, instead of board connectors 91, into which board terminals 101 are inserted.

[0062] The sub-board support member 105 has a flat plate portion 106 and two mounting portions 107. The flat plate portion 106 is fixed to the sub-board 100. The flat plate portion 106 is arranged so as to overlap the upper surface of the sub-board 100. The flat plate portion 106, together with the sub-board 100, is arranged across the case 80 and the sub-board space 75. The mounting portion 107 has a cylindrical shape. The inner diameter of the mounting portion 107 is the same as the diameter of the support pillar 85 of the case 80. The mounting portion 107 is connected to both ends of the flat plate portion 106 in the front-rear direction. The two mounting portions 107 are sandwiched between the side wall portion 84 of the case body 81 and the main board 90. The sub-board support member 105 supports the sub-board 100. By including the sub-board support member 105, the sub-board 100 can be supported more reliably.

[0063] Next, a method for assembling the stator unit 50A will be described.

[0064] The assembly method of the stator unit 50A is the same as the assembly method of the stator unit 50 of the first embodiment, from the step of injection-molding the housing 70 to the step of joining the case main body 81 to the housing 70. The flat plate portion 106 of the sub-substrate support member 105 is fixed to the sub-substrate 100. While inserting the support posts 85 into the mounting portions 107, the sub-substrate 100 and the flat plate portion 106 are inserted into the sub-substrate space 75 through the case opening 84a. At this time, both ends of the sub-substrate 100 facing each other in the front-rear direction are press-fitted into the press-fit grooves 77. In this embodiment, only the tip of the second end 100b of the sub-substrate 100 is press-fitted into the press-fit groove 77. As a result, the sub-substrate 100 is supported by the press-fit groove 77. Then, while inserting the board terminals 101 of the sub-substrate 100 into the through holes 93 of the main substrate 90, the tip 85a of the support post 85 is inserted into the through hole 92 of the main substrate 90. The tip 85a of the support pillar 85 is enlarged and deformed by infrared caulking. As a result, the main board 90 is supported by the support pillar 85, and the mounting portion 107 is sandwiched between the side wall portion 84 and the main board 90. The sub-board 100 is supported by the sub-board support member 105. The multiple terminals 65 of the stator 60 and the board terminals 101 of the sub-board 100 are soldered to the main board 90. The lid 82 is joined to the case body 81, completing the stator unit 50A.

[0065] The motor-operated valve 1A has the same effects as the motor-operated valve 1 according to the first embodiment.

[0066] (Third Example) A motor-operated valve 1B according to a third embodiment of the present invention will now be described with reference to FIGS.

[0067] FIG. 15 is a cross-sectional view of a motor-operated valve according to a third embodiment of the present invention. FIG. 16 is a cross-sectional view of a stator unit included in the motor-operated valve of FIG. 15. FIGS. 17 and 18 are perspective views of a sub-board and a sub-board support member included in the motor-operated valve of FIG. 15. FIGS. 19 and 20 are diagrams showing the positional relationship between the pole teeth of the stator and two magnetic sensors included in the motor-operated valve of FIG. 15. FIG. 19 is a view of the stator as seen from the axial direction. In FIG. 19, the magnetic poles of the magnet rotor are schematically shown as semi-elliptical. In FIG. 19, the inner members of the magnet rotor and the stator mold are not shown. FIG. 20 is a view of the stator as seen from the radial direction. In FIG. 20, the magnetic sensors and pole teeth of the stator are schematically shown. In the following description, components that are the same (including substantially the same) as those in the motor-operated valve 1A according to the second embodiment are designated by the same reference numerals, and description thereof will be omitted.

[0068] As shown in each figure, the motor-operated valve 1B has a valve body 10, a can 20, a drive mechanism 30B, a valve element 40, and a stator unit 50B. The drive mechanism 30B has the same configuration as the drive mechanism 30 of the motor-operated valve 1A, except that the permanent magnet 38 and the fixture 39 are omitted. The stator unit 50B has a stator 60, a housing 70, a case 80, a main board 90, a sub-board 100, a sub-board support member 105, and two magnetic sensors 110B.

[0069] The magnetic sensor 110B is a Hall IC. The magnetic sensor 110B has a surface-mount type package. The magnetic sensor 110B is provided at the second end 100b of the sub-substrate 100. The two magnetic sensors 110B are arranged side by side in the front-to-rear direction. Specifically, the two magnetic sensors 110B are arranged equidistantly about the axis L and spaced apart around the axis L. The two magnetic sensors 110B are arranged side by side along the outer surface of the partition wall 76 when viewed from the axis L direction. The magnetic sensor 110B is arranged to laterally face the magnet rotor 31 with the can 20 and the partition wall 76 interposed therebetween. The magnetic sensor 110B detects the magnetic flux density generated by the magnetic poles of the magnet rotor 31. The magnetic sensor 110B outputs a signal corresponding to the detected magnetic flux density. The rotation angle (amount of rotation) and rotation direction of the magnet rotor 31 can be detected based on the signal from the magnetic sensor 110B.

[0070] In the motor-operated valve 1B, the board terminal 101 is attached to the upper surface of the sub-board 100, and the flat plate portion 106 of the sub-board support member 105 is attached to the lower surface of the sub-board 100.

[0071] As shown in FIG. 20 , one of the two magnetic sensors 110B is located on the center line C1 of one of the pole teeth 61a of the upper stator 61, while the other is not located on any of the center lines of the pole teeth 61a. Each center line is a straight line parallel to the axis L. This arrangement shifts the phases of the signal waveforms of the two magnetic sensors 110B, allowing the rotation direction of the magnet rotor 31 to be detected based on the signal waveforms. In particular, in this embodiment, the other of the two magnetic sensors 110B is located on the center line C2 of the pole tooth 62b of the lower stator 62. In other words, the center line C2 passes through the center between the adjacent pole teeth 61a and 61b. This shortens the period during which the signal waveforms of the two magnetic sensors 110B overlap. Specifically, if, for example, Hall ICs that output a signal H when the N pole is nearby and a signal L when the N pole is not nearby are used as the two magnetic sensors 110B, it is possible to shorten the period during which the signals H overlap in the signal waveforms of the two magnetic sensors 110B while the magnet rotor 31 is rotating, thereby improving the detection accuracy of the rotation angle of the magnet rotor 31.

[0072] In this specification, terms indicating the shape of a member, such as "cylinder" or "column," are also used to refer to members that substantially have the shape of that term. For example, a "cylindrical member" includes both a cylindrical member and a substantially cylindrical member.

[0073] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. Any addition, deletion, or design change of components by a person skilled in the art to the above-described embodiments, or any combination of features of the embodiments, is also included within the scope of the present invention as long as it does not deviate from the spirit of the present invention. [Explanation of symbols]

[0074] 1...motor-operated valve, 1A...motor-operated valve, 1B...motor-operated valve, 10...valve body, 11...main body portion, 12...cylindrical portion, 12a...fitting hole, 13...flange portion, 14...valve chamber, 15...flow path, 16...flow path, 17...port, 20...can, 30...drive mechanism, 30B...drive mechanism, 31...magnet rotor, 32...valve stem holder, 32c...female thread, 33...guide bush, 33a...first cylindrical portion, 33b...second Cylindrical portion, 33c... male thread, 34... valve stem, 34a... upper portion, 34b... stepped portion, 35... support ring, 36... push nut, 37... valve closing spring, 38... permanent magnet, 39... fixing device, 40... valve body, 50... stator unit, 50A... stator unit, 50B... stator unit, 60... stator, 60a... inner peripheral surface, 61... upper stage stator, 61a, 61b... pole teeth, 6 2...lower stator, 62a, 62b...pole teeth, 63...mold, 64...terminal support portion, 65...terminal, 70...housing, 71...peripheral wall portion, 72...dome portion, 72a...inner peripheral surface, 73...cylindrical portion, 74...inner space, 75...sub-board space, 76...partition wall, 77...press-fit groove, 78...projection, 78a...projection, 78b...projection, 80...case, 81...case body, 82...lid, 83...connector , 84...side wall portion, 84a...case opening, 85...support column, 85a...tip, 90...main board, 91...board connector, 92...through hole, 93...through hole, 100...sub-board, 100a...first end, 100b...second end, 101...board terminal, 105...sub-board support member, 106...flat plate portion, 107...mounting portion, 110...magnetic sensor, 110B...magnetic sensor, L...axis

Claims

1. An electric valve having a valve body, a can joined to the valve body, a magnet rotor arranged inside the can, a permanent magnet rotated together with the magnet rotor, and a stator unit having an inner space in which the can is arranged, the stator unit includes a housing, a cylindrical stator housed in the housing and constituting a motor together with the magnet rotor, a flat main board, a flat sub-board, and a magnetic sensor provided on the sub-board and arranged to detect a magnetic field generated by the permanent magnet, the housing has a sub-board space disposed adjacent to the inner space, a first end of the sub-board connected to the main board via a board terminal; a second end of the sub-board is disposed in the sub-board space adjacent to the inner space; The motor-operated valve is characterized in that the magnetic sensor is disposed closer to the inner space than the board terminal.

2. The motor-operated valve according to claim 1 , wherein the housing has a partition wall that separates the inner space from the sub-substrate space.

3. 3. The motor-operated valve according to claim 1, wherein the housing has a press-fit groove into which the sub-board is press-fitted.

4. The motor-operated valve according to claim 3 , wherein an inner surface of the press-fit groove is provided with a protrusion that is elastically deformed when the sub-board is press-fitted into the press-fit groove.

5. The motor-operated valve according to any one of claims 1 to 4, wherein the magnetic sensor is disposed at the second end.

6. The main board is arranged parallel to the axial direction of the stator, The motor-operated valve according to any one of claims 1 to 5, wherein the sub-board is disposed at a right angle to the main board.

7. The motor-operated valve according to claim 6 , wherein the sub-board is arranged so as to be parallel to the axial direction.

8. The stator unit further has a case joined to the housing, the case has a wall portion and a support pillar provided on the wall portion, the wall portion has a case opening connected to the sub-board space, The support pillar extends in a direction perpendicular to the axial direction, and a tip of the support pillar is directed in a direction away from the internal space, the main board has a through hole, the sub-board is disposed across the case and the sub-board space, a sub-board support member is attached to the sub-board; the sub-board support member has a cylindrical mounting portion, the support pillar is disposed inside the mounting portion and in the through hole; The diameter of the tip of the support column is larger than the diameter of the through hole, 8. The motor-operated valve according to claim 6, wherein the mounting portion is sandwiched between the wall portion and the main board.

9. The motor-operated valve is a valve body that approaches a port provided in the valve body when the magnet rotor rotates in one direction and moves away from the port when the magnet rotor rotates in the other direction; The motor-operated valve according to any one of claims 1 to 8, further comprising: a calculation device that calculates an opening degree of the port based on a signal output by the magnetic sensor.

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