Electric valve, valve device, and method for manufacturing stator unit

Abstract

[Problem] To provide a small electric valve and a small valve device capable of suppressing falling of a stator unit from a valve body assembly, and a method for manufacturing a stator unit used for the electric valve and the valve device. [Solution] A valve body assembly 5 of an electric valve 1 has a rotor case 30 and a rotor 35 placed inside the rotor case 30. A stator unit 8 has an inner case 60 made of metal, a housing 80 made of synthetic resin, and a stator 90. A peripheral wall part 61 and a bottom wall part 62 of the inner case 60 are placed inside the rotor 35. An annular part 63 of the inner case 60 is joined to an upper end of the rotor case 30. The stator 90 is embedded in a support part 84 of the housing 80, and the support part 84 is integrally molded with the stator 90 and the inner case 60.

Description

Motor-operated valve, valve device, and method for manufacturing stator unit

[0001] The present invention relates to a motor-operated valve and a valve device, and a method for manufacturing a stator unit used in the motor-operated valve and the valve device.

[0002] Patent Document 1 discloses an example of a conventional motor-operated valve. The motor-operated valve has a valve body, a valve element, a case, a magnet rotor, and a stator unit including a stator. The case has a cylindrical shape and is joined to the valve body. The magnet rotor is disposed inside the case. The stator is disposed outside the case. The magnet rotor and the stator constitute a motor. When the magnet rotor rotates, the valve element moves.

[0003] JP 2022-83453 A

[0004] The motor-operated valve of Patent Document 1 is used, for example, in a valve device 803 shown in FIG. 10 . The valve device 803 includes a plurality of motor-operated valves 801 and a flow path block 850. The flow path block 850 has a rectangular parallelepiped shape and includes a mounting surface 851 on which the plurality of motor-operated valves 801 are disposed. The motor-operated valve 801 has a large outer diameter because the stator is disposed on the outside of the case, requiring a large space for disposing the motor-operated valves 801. Therefore, the flow path block 850 requires a relatively large mounting surface 851.

[0005] The motor-operated valve can be made smaller by placing the stator inside the magnet rotor. Fig. 11 shows an example of such a motor-operated valve 901. The motor-operated valve 901 has a valve body assembly 905 and a stator unit 908.

[0006] The valve body assembly 905 includes a valve body 910, a valve element 920, a rotor case 930, a magnet rotor 935, a drive member 950, and an inner case 960. The rotor case 930 is attached to the valve body 910. The magnet rotor 935 has a cylindrical shape and is disposed inside the rotor case 930. The drive member 950 is coaxially connected to the magnet rotor 935. When the drive member 950 rotates together with the magnet rotor 935, the valve element 920 moves vertically. The inner case 960 includes a peripheral wall portion 961, a bottom wall portion 962 connected to the lower end of the peripheral wall portion 961, and an annular portion 963 connected to the upper end of the peripheral wall portion 961. The peripheral wall portion 961 and the bottom wall portion 962 are disposed inside the magnet rotor 935. The annular portion 963 is joined to the upper end of the rotor case 930.

[0007] The stator unit 908 has a housing 980 and a stator 990. The housing 980 has a cylindrical support portion 984, and the stator 990 is embedded in the support portion 984. The support portion 984 is disposed inside the peripheral wall portion 961 of the inner case 960, and the magnet rotor 935 and the stator 990 face each other in the radial direction with the inner case 960 sandwiched therebetween. The magnet rotor 935 and the stator 990 constitute a stepping motor 998. A protrusion provided on the inner peripheral surface of the peripheral wall portion 961 engages with a recess provided on the outer peripheral surface of the support portion 984, preventing the support portion 984 from slipping out of the inner case 960.

[0008] However, when the plug is removed from the connector portion 987 of the housing 980 or when vibration is applied to the electric valve 901, there is a risk that the support portion 984 will come out of the inner case 960 and the stator unit 908 will fall off from the valve body assembly 905.

[0009] Therefore, an object of the present invention is to provide a small electric valve and valve device that can prevent the stator unit from falling off from the valve body assembly, and a method for manufacturing a stator unit used in the electric valve and valve device.

[0010] In order to achieve the above object, one aspect of the present invention provides an electric valve having a valve body assembly and a stator unit, wherein the valve body assembly has a cylindrical rotor case attached to the valve body and a cylindrical magnet rotor arranged inside the rotor case, the stator unit has a housing made of synthetic resin, an inner case made of metal, and a stator, the inner case has a cylindrical peripheral wall portion, a disk-shaped bottom wall portion connected to a first end of the peripheral wall portion, and an annular portion whose inner peripheral edge is connected to a second end of the peripheral wall portion, the outer peripheral edge of the annular portion is joined to one end of the rotor case, the peripheral wall portion and the bottom wall portion are arranged inside the magnet rotor, the housing has a cylindrical support portion arranged inside the peripheral wall portion, the stator is embedded in the support portion, and the support portion is integrally molded with the stator and the inner case.

[0011] In the present invention, it is preferable that the peripheral wall portion has a through hole, and that the outer peripheral surface of the support portion is provided with a protrusion that is disposed in the through hole.

[0012] In the present invention, it is preferable that the housing further includes a ring portion disposed on the outer side of the peripheral wall portion, and the ring portion is connected to the protrusion.

[0013] In the present invention, it is preferable that the outer diameter of the ring portion is the same as the inner diameter of the rotor case, and the outer peripheral surface of the ring portion contacts the inner peripheral surface of the rotor case.

[0014] In the present invention, it is preferable that a recess is provided on the inner surface of the peripheral wall portion and a protrusion is provided on the outer surface of the support portion that is positioned in the recess, or that a recess is provided on the outer surface of the support portion and a protrusion is provided on the inner surface of the peripheral wall portion that is positioned in the recess.

[0015] In the present invention, it is preferable that the housing further has a disk-shaped base, the support portion is connected to one surface of the base, the one surface is in contact with the annular portion, and the diameter of the one surface is smaller than the outer diameter of the annular portion.

[0016] In order to achieve the above object, a valve device according to another aspect of the present invention includes the motor-operated valve and a flow path block having a mounting surface on which the motor-operated valve is disposed.

[0017] In order to achieve the above object, another aspect of the present invention provides a method for manufacturing a stator unit having a synthetic resin housing, a metal inner case, and a stator, wherein the inner case has a cylindrical peripheral wall portion, a disk-shaped bottom wall portion connected to a first end of the peripheral wall portion, and an annular portion whose inner peripheral edge is connected to a second end of the peripheral wall portion, the housing has a housing main body having a cylindrical support portion arranged inside the peripheral wall portion, the stator is installed inside the peripheral wall portion, and the inner case is installed in a cavity of an injection mold, and synthetic resin is injected into the cavity to mold the housing main body.

[0018] In order to achieve the above object, another aspect of the present invention provides a method for manufacturing a stator unit having a synthetic resin housing, a metal inner case, and a stator, wherein the inner case has a cylindrical peripheral wall portion, a disk-shaped bottom wall portion connected to a first end of the peripheral wall portion, and an annular portion whose inner peripheral edge is connected to a second end of the peripheral wall portion, the housing has a housing main body having a cylindrical support portion arranged inside the peripheral wall portion, the stator is installed inside the peripheral wall portion, and the inner case is installed in a cavity of a casting mold, and synthetic resin is injected into the cavity to form the housing main body.

[0019] According to the present invention, the valve body assembly has a magnet rotor disposed inside the rotor case. The stator unit has a housing, an inner case, and a stator. The peripheral wall and bottom wall of the inner case are disposed inside the magnet rotor, and the annular portion of the inner case is joined to one end of the rotor case. The stator is embedded in a support portion of the housing, and the support portion is disposed inside the peripheral wall portion. The support portion is integrally molded with the stator and inner case. As a result, the support portion is firmly connected to the inner case joined to the rotor case, and the support portion can be prevented from coming off the inner case. This allows the motor-operated valve to be made smaller, and the stator unit can be prevented from falling off the valve body assembly.

[0020] FIG. 1 is a front view of a motor-operated valve according to a first embodiment of the present invention. FIG. 2 is a plan view of the motor-operated valve of FIG. 1. FIG. 3 is a bottom view of the motor-operated valve of FIG. 1. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 1. FIG. 5 is a cross-sectional view of a valve body assembly of the motor-operated valve of FIG. 1. FIG. 6 is a cross-sectional view of a stator unit of the motor-operated valve of FIG. 1. FIG. 7 is a cross-sectional view showing the configuration of a first modified example of the stator unit of FIG. 6. FIG. 8 is a cross-sectional view showing the configuration of a second modified example of the stator unit of FIG. 6. FIG. 9 is a cross-sectional view of a valve device according to a second embodiment of the present invention. FIG. 11 is a plan view of a conventional valve device. FIG. 12 is a cross-sectional view of a conventional motor-operated valve.

[0021] 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 8. The motor-operated valve according to this embodiment is used, for example, to control the flow rate of refrigerant in an automotive air conditioner.

[0022] FIG. 1, FIG. 2, and FIG. 3 are a front view, a plan view, and a bottom view of a motor-operated valve according to a first embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1. FIG. 4 is a cross-sectional view taken along the axis L of the motor-operated valve. FIG. 5 is a cross-sectional view of a valve body assembly of the motor-operated valve of FIG. 1. FIG. 6 is a cross-sectional view of a stator unit of the motor-operated valve of FIG. 1. FIG. 7 is a cross-sectional view showing the configuration of a first modified example of the stator unit of FIG. 6. FIG. 8 is a cross-sectional view showing the configuration of a second modified example of the stator unit of FIG. 6. In each figure, the X direction indicated by arrow X is the left-right 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 direction of the axis L). The side with the letter "X" on the arrow X indicates the rightward direction, the side with the letter "Y" on the arrow Y indicates the forward direction, and the side with the letter "Z" on the arrow Z indicates the upward direction.

[0023] As shown in FIGS. 1 to 4, the motor-operated valve 1 according to the first embodiment includes a valve body assembly 5 and a stator unit 8.

[0024] As shown in FIG. 4 , the valve body assembly 5 includes a valve body 10 , a valve element 20 , a rolling bearing 25 , a rotor case 30 , a rotor 35 , and a drive member 50 .

[0025] The valve body 10 includes a body member 11 , a sleeve 18 , and a valve body support plate 19 .

[0026] The main body member 11 is made of a metal such as an aluminum alloy and has a valve chamber 12, a valve port 13, a valve seat 14, a first connecting passage 15, a second connecting passage 16, and a mounting hole 17.

[0027] The main body member 11 has a head portion 11a. The head portion 11a has a hexagonal outer shape and is disposed at the upper end of the main body member 11. A manufacturing tool for rotating the main body member 11 around the axis L is attached to the head portion 11a.

[0028] The valve port 13 is connected to the valve chamber 12. The valve port 13 is surrounded by a valve seat 14 in the valve chamber 12. A first connecting passage 15 extends in the left-right and front-rear directions from the valve chamber 12. A second connecting passage 16 extends downward from the valve port 13.

[0029] The mounting hole 17 is disposed on the upper surface 11c of the main body member 11. The mounting hole 17 is connected to the valve chamber 12. The main body member 11 has a holding surface 11d. The holding surface 11d is an annular flat surface facing upward. The holding surface 11d is disposed at the connection point between the valve chamber 12 and the mounting hole 17.

[0030] The main body member 11 has a male thread 11f and a female thread 11g. The male thread 11f is disposed on the outer peripheral surface of the main body member 11. The female thread 11g is disposed on the inner peripheral surface of the mounting hole 17.

[0031] The sleeve 18 is made of synthetic resin or metal. The sleeve 18 integrally includes a sleeve body 18a and a flange portion 18b. The sleeve body 18a has a stepped cylindrical shape. The inner diameter of the upper portion of the sleeve body 18a is larger than the outer diameter of the lower portion of the sleeve body 18a. The flange portion 18b has an annular plate shape. The inner peripheral edge of the flange portion 18b is connected to the upper end of the sleeve body 18a. The sleeve body 18a is disposed in the valve chamber 12. The flange portion 18b contacts the retaining surface 11d.

[0032] The valve disc support plate 19 is made of synthetic resin or metal. The valve disc support plate 19 has an annular disc shape. The outer peripheral edge of the valve disc support plate 19 is circular and the inner peripheral edge is oval. The valve disc support plate 19 is disposed below the mounting hole 17. The lower surface of the valve disc support plate 19 contacts the flange portion 18b of the sleeve 18.

[0033] The valve body 20 is made of synthetic resin or metal and integrally includes a shaft portion 21 and a valve portion 22.

[0034] The shaft portion 21 has an oval cylindrical shape. The outer shape of the cross section of the shaft portion 21 is the same oval shape as the inner peripheral edge of the valve body support plate 19. The major diameter of the cross section of the shaft portion 21 is the same as the inner diameter of the lower part of the sleeve main body 18a. The shaft portion 21 has a threaded hole 21h and a female thread 21k. The threaded hole 21h is located on the upper end surface of the shaft portion 21. The female thread 21k is located on the inner peripheral surface of the threaded hole 21h.

[0035] The shaft portion 21 is disposed inside the sleeve 18 and inside the valve disc support plate 19. The shaft portion 21 is supported by the sleeve 18 and the valve disc support plate 19 so as to be movable in the vertical direction. Rotation of the shaft portion 21 about the axis L is restricted by the valve disc support plate 19. The shape of the shaft portion 21 and the shape of the valve disc support plate 19 may be any shape as long as they restrict rotation of the shaft portion 21 about the axis L.

[0036] The valve portion 22 has a truncated cone shape with a diameter that decreases from top to bottom. The valve portion 22 is coaxially connected to the lower end of the shaft portion 21. The valve portion 22 is disposed in the valve chamber 12 and the valve port 13. The valve portion 22 faces the valve port 13 and the valve seat 14 in the vertical direction. When the valve portion 22 comes into contact with the valve seat 14, the valve port 13 closes. When the valve portion 22 moves away from the valve seat 14, the valve port 13 opens, and a throttled flow path is formed between the valve portion 22 and the valve port 13.

[0037] The rolling bearing 25 is a radial bearing. The rolling bearing 25 may be a thrust bearing.

[0038] The rotor case 30 is made of a non-magnetic material. The rotor case 30 is made of, for example, a non-magnetic metal such as stainless steel. In this specification, a "non-magnetic material" refers to a material that has the property of not being magnetized (including the property of not being substantially magnetized) even when placed in a magnetic field. The rotor case 30 may be made of a synthetic resin. The rotor case 30 has a generally cylindrical shape. The rotor case 30 integrally includes a first case portion 31, a second case portion 32, and a connecting portion 33.

[0039] The first case portion 31 has a cylindrical shape. The first case portion 31 has a male thread 31g. The male thread 31g is arranged on the lower part of the outer circumferential surface of the first case portion 31. The first case portion 31 is arranged in the mounting hole 17 of the main body member 11, and the male thread 31g is threadedly engaged with the female thread 11g. The first case portion 31 is attached to the main body member 11 by a threaded structure. An O-ring 34 seals the space between the main body member 11 and the first case portion 31 at the mounting hole 17. The lower end of the first case portion 31 contacts the upper surface of the valve element support plate 19. The flange portion 18b of the sleeve 18 and the valve element support plate 19 are held between the lower end of the first case portion 31 and the holding surface 11d of the main body member 11.

[0040] The first case portion 31 has a mounting surface 31h. The mounting surface 31h is an annular flat surface facing upward. The mounting surface 31h is disposed on the inner circumferential surface of the first case portion 31. The rolling bearing 25 is disposed inside the first case portion 31, and the lower end of the outer ring of the rolling bearing 25 is in contact with the mounting surface 31h. The rolling bearing 25 is fixed to the first case portion 31.

[0041] The second case portion 32 has a cylindrical shape. The inner diameter of the second case portion 32 is larger than the outer diameter of the first case portion 31. The connecting portion 33 has an annular plate shape. The inner peripheral edge of the connecting portion 33 is connected to the upper end of the first case portion 31, and the outer peripheral edge of the connecting portion 33 is connected to the lower end of the second case portion 32. The first case portion 31, the second case portion 32, and the connecting portion 33 are arranged coaxially.

[0042] The rotor 35 has a generally cylindrical shape and is disposed inside the second case portion 32 of the rotor case 30. The rotor 35 integrally includes a cylindrical portion 36, a bottom portion 37, and a connecting portion 38.

[0043] The cylindrical portion 36 has multiple magnetic poles (multiple north poles and multiple south poles). The multiple north poles and multiple south poles are alternately arranged at equal angular intervals in the circumferential direction on the inner circumferential surface of the cylindrical portion 36. The multiple north poles and multiple south poles extend in the vertical direction. The cylindrical portion 36 has, for example, five north poles and five south poles. The bottom portion 37 has an annular plate shape. The outer periphery of the bottom portion 37 is connected to the lower end of the cylindrical portion 36. The connecting portion 38 has a cylindrical shape. The connecting portion 38 is connected to the inner periphery of the bottom portion 37 and is arranged coaxially with the bottom portion 37. The rotor 35 is a magnet rotor.

[0044] The drive member 50 is made of synthetic resin or metal. The drive member 50 has a generally cylindrical shape. The drive member 50 has a male thread 51k. The male thread 51k is arranged on the outer peripheral surface of the lower part of the drive member 50. The male thread 51k is threadedly engaged with the female thread 21k of the valve body 20. Note that the drive member 50 may have a female thread and the valve body 20 may have a male thread. The female thread 21k and the male thread 51k form a feed screw mechanism that moves the valve body 20 in the vertical direction. The center of the drive member 50 is rotatably supported by the rolling bearing 25. The drive member 50 has a support surface 50a. The support surface 50a is an annular flat surface facing downward. The support surface 50a contacts the upper end of the inner ring of the rolling bearing 25. The upper part of the drive member 50 is fitted into the connecting portion 38. The drive member 50 rotates together with the rotor 35.

[0045] As shown in FIG. 6 , the stator unit 8 includes an inner case 60 , a housing 80 , a stator 90 , and a control device 100 .

[0046] The inner case 60 is made of a non-magnetic material. For example, the inner case 60 is made of a non-magnetic metal such as stainless steel. The inner case 60 may also be made of a synthetic resin. The inner case 60 integrally includes a peripheral wall portion 61, a bottom wall portion 62, and an annular portion 63.

[0047] The peripheral wall portion 61 has a cylindrical shape and has a plurality of through holes 61 a. The plurality of through holes 61 a are arranged in an upper portion of the peripheral wall portion 61.

[0048] The bottom wall portion 62 has a disk shape. The outer peripheral edge of the bottom wall portion 62 is connected to the lower end (first end) of the peripheral wall portion 61.

[0049] The annular portion 63 has a circular plate shape. The inner peripheral edge of the annular portion 63 is connected to the upper end (second end) of the peripheral wall portion 61. The outer peripheral edge of the annular portion 63 is joined to the upper end (one end) of the second case portion 32 of the rotor case 30. The annular portion 63 is welded to the rotor case 30. The annular portion 63 may also be joined to the rotor case 30 with an adhesive. The peripheral wall portion 61, the bottom wall portion 62, and the annular portion 63 are arranged coaxially.

[0050] The peripheral wall portion 61 and the bottom wall portion 62 are disposed inside the rotor 35. The second case portion 32 of the rotor case 30 and the inner case 60 form a rotor space 65. The rotor 35 is disposed in the rotor space 65. The rotor space 65 is sealed from the outside of the motor-operated valve 1. The rotor space 65 is connected to the valve chamber 12 through gaps between the members of the valve body assembly 5. The refrigerant in the valve chamber 12 is introduced into the rotor space 65.

[0051] The housing 80 is made of synthetic resin and includes a housing body 81 and a cover 85 .

[0052] The housing body 81 integrally includes a wall portion 82 , a base portion 83 , a support portion 84 , and a ring portion 89 .

[0053] The wall portion 82 has a cylindrical shape. The outer diameter of the wall portion 82 is larger than the outer diameter of the second case portion 32 of the rotor case 30.

[0054] The base 83 has a disk shape. The base 83 is connected to the lower end of the wall portion 82. The base 83 is disposed coaxially with the annular portion 63 of the inner case 60, and a lower surface 83a (one surface) of the base 83 is in contact with the upper surface of the annular portion 63. The diameter of the lower surface 83a is smaller than the outer diameter of the annular portion 63, and the outer peripheral edge of the annular portion 63 extends radially outward from the lower portion of the base 83.

[0055] The support portion 84 has a cylindrical shape. The support portion 84 is connected to the lower surface 83a of the base portion 83. The outer diameter of the support portion 84 is the same as the inner diameter of the peripheral wall portion 61 of the inner case 60. A plurality of protrusions 84a are provided on the outer peripheral surface of the support portion 84. The support portion 84 is arranged inside the peripheral wall portion 61, and the protrusions 84a are arranged in the through holes 61a of the peripheral wall portion 61.

[0056] The ring portion 89 has an annular shape. The inner diameter of the ring portion 89 is the same as the outer diameter of the peripheral wall portion 61. The inner peripheral surface of the ring portion 89 contacts the outer peripheral surface of the peripheral wall portion 61 and is connected to the protrusion 84a of the support portion 84. The upper end surface of the ring portion 89 contacts the lower surface of the annular portion 63. The outer diameter of the ring portion 89 is the same as the inner diameter of the second case portion 32. The outer peripheral surface of the ring portion 89 contacts the inner peripheral surface of the second case portion 32, and the ring portion 89 is fitted into the second case portion 32. The wall portion 82, the base portion 83, the support portion 84, and the ring portion 89 are arranged coaxially. Note that the ring portion 89 may be omitted from the motor-operated valve 1.

[0057] The lid body 85 integrally includes a lid portion 86 and a connector portion 87. The lid portion 86 has a disk shape. The outer peripheral edge of the lid portion 86 is joined to the upper end of the wall portion 82. The connector portion 87 has an elongated cylindrical shape. The connector portion 87 extends upward from the center of the upper surface of the lid portion 86. The lid portion 86 and the connector portion 87 are arranged coaxially. The wall portion 82, the base portion 83, and the lid portion 86 form a control device space 88.

[0058] The stator 90 has two stacks 91. Each stack 91 has a hollow ring-shaped yoke, a bobbin arranged inside the yoke, and a coil wound around the bobbin. A plurality of claw-pole-shaped pole teeth are provided on the outer periphery of the yoke. The coils are electrically connected to coil terminals 94. One stack 91 is arranged coaxially above the other stack 91.

[0059] The stator 90 is embedded in the support portion 84 of the housing 80. The stator 90, together with the support portion 84, is disposed inside the peripheral wall portion 61 of the inner case 60. The rotor 35 is disposed outside the peripheral wall portion 61. The rotor 35 and the stator 90 face each other in the radial direction with the peripheral wall portion 61 sandwiched therebetween. The rotor 35 and the stator 90 constitute a stepping motor 98. Note that the motor-operated valve 1 may have other types of motors, such as a brushless DC motor.

[0060] The housing main body 81 is integrally molded with the inner case 60 and the stator 90. Specifically, the housing main body 81 is formed by insert molding, in which the inner case 60 and the stator 90 are placed in a mold and a synthetic resin is filled into the mold.

[0061] A method for manufacturing the housing body 81 will now be described.

[0062] (Method 1) The housing main body 81 is molded using injection molding. An injection mold is used that has a cavity formed in a shape corresponding to the housing main body 81. After the inner case 60 is placed in the cavity of the injection mold, the stator 90 is placed inside the peripheral wall portion 61 of the inner case 60. Alternatively, the stator 90 may be placed inside the peripheral wall portion 61 of the inner case 60, and then the inner case 60 may be placed in the cavity of the injection mold. Then, molten synthetic resin is injected into the cavity of the injection mold. When the synthetic resin hardens, the housing main body 81 is completed, with the inner case 60 and the stator 90 integrated together.

[0063] (Method 2) The housing main body 81 is molded using cast molding. A cast mold is used that has a cavity with a shape corresponding to the housing main body 81. The cast mold has, for example, a cup shape. After the inner case 60 is placed in the cavity of the cast mold, the stator 90 is placed inside the peripheral wall portion 61 of the inner case 60. Alternatively, the stator 90 may be placed inside the peripheral wall portion 61 of the inner case 60, and then the inner case 60 may be placed in the cavity of the cast mold. Then, molten synthetic resin is injected into the cavity of the cast mold. When the synthetic resin hardens, the housing main body 81 is completed, integrated with the inner case 60 and the stator 90.

[0064] The control device 100 is disposed in the control device space 88. The control device 100 has a board 101, a terminal component 102, and a computer (not shown). The board 101 is a printed circuit board on which electronic components including a computer are mounted. A plurality of coil terminals 94 of the stator 90 are connected to the board 101. The terminal component 102 has a plurality of connector terminals 103. One end of each of the plurality of connector terminals 103 is connected to the board 101, and the other end is disposed inside the connector portion 87. The computer controls the motor-operated valve 1.

[0065] In the electric valve 1, the main body member 11 (valve chamber 12, valve port 13, valve seat 14, mounting hole 17), sleeve 18, valve body support plate 19, valve body 20, rolling bearing 25, rotor case 30, rotor 35, drive member 50, inner case 60, housing main body 81, cover body 85, and stator 90 each have a central axis that coincides with the axis L.

[0066] Next, the operation of the motor-operated valve 1 will be described.

[0067] In the motor-operated valve 1, current is supplied to the multiple coils of the stator 90 to rotate the rotor 35 in a first direction. The drive member 50 rotates together with the rotor 35. Due to the feed screw action between the male thread 51k of the drive member 50 and the female thread 21k of the valve element 20, the valve element 20 moves downward, reducing the opening area of ​​the valve port 13 (throttled flow path). When the valve element 20 contacts the valve seat 14 and closes the valve port 13, the motor-operated valve 1 is in a fully closed state.

[0068] In the motor-operated valve 1, current is supplied to the multiple coils of the stator 90 to rotate the rotor 35 in the second direction. The drive member 50 rotates together with the rotor 35. Due to the feed screw action between the male thread 51k of the drive member 50 and the female thread 21k of the valve element 20, the valve element 20 moves upward and away from the valve seat 14, increasing the opening area of ​​the valve orifice 13. When the valve element 20 is farthest from the valve orifice 13, 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 13 is at its largest.

[0069] Furthermore, the housing body 81 of the housing 80 of the stator unit 8 is integrally molded with the inner case 60 and the stator 90. In particular, the protrusion 84a of the support portion 84 is disposed in the through-hole 61a of the peripheral wall portion 61 of the inner case 60, and the ring portion 89 is connected to the protrusion 84a. This allows the support portion 84 and the ring portion 89 to be firmly joined to the inner case 60.

[0070] As described above, the motor-operated valve 1 includes a valve body assembly 5 and a stator unit 8. The valve body assembly 5 includes a cylindrical rotor case 30 attached to the valve body 10 and a cylindrical rotor 35 disposed inside the rotor case 30. The stator unit 8 includes a synthetic resin housing 80, a metal inner case 60, and a stator 90. The inner case 60 includes a cylindrical peripheral wall portion 61, a disk-shaped bottom wall portion 62 connected to the lower end of the peripheral wall portion 61, and an annular portion 63 whose inner peripheral edge is connected to the upper end of the peripheral wall portion 61. The outer peripheral edge of the annular portion 63 is joined to the upper end of the rotor case 30. The peripheral wall portion 61 and the bottom wall portion 62 are disposed inside the rotor 35. The housing 80 includes a cylindrical support portion 84 disposed inside the peripheral wall portion 61. The stator 90 is embedded in the support portion 84. The support portion 84 is integrally formed with the stator 90 and the inner case 60 .

[0071] As a result, the stator 90 is disposed inside the rotor 35, making it possible to reduce the size of the motor-operated valve 1. Furthermore, the support portion 84 is firmly connected to the inner case 60, which is joined to the rotor case 30, making it possible to prevent the support portion 84 from coming off the inner case 60. Therefore, it is possible to reduce the size of the motor-operated valve 1 and also to prevent the stator unit 8 from falling off the valve body assembly 5.

[0072] Furthermore, the peripheral wall portion 61 has a through hole 61a. A protrusion 84a is provided on the outer peripheral surface of the support portion 84 and is positioned in the through hole 61a. This allows the support portion 84 to be more firmly coupled to the inner case 60, more effectively preventing the stator unit 8 from falling off the valve body assembly 5. Note that the through hole 61a and the protrusion 84a may be omitted from the motor-operated valve 1.

[0073] The housing 80 also has a ring portion 89 disposed on the outside of the peripheral wall portion 61. The ring portion 89 is connected to the protrusion 84a of the support portion 84. This configuration allows the support portion 84 to be more firmly coupled to the inner case 60, and more effectively prevents the stator unit 8 from falling off from the valve body assembly 5. Alternatively, the annular portion 63 of the inner case 60 may have a through-hole, and the lower surface 83a of the base 83 of the housing 80 may have a protrusion disposed in the through-hole, and the ring portion 89 may be connected to the protrusion.

[0074] Furthermore, the outer diameter of the ring portion 89 is the same as the inner diameter of the second case portion 32 of the rotor case 30. The outer peripheral surface of the ring portion 89 contacts the inner peripheral surface of the second case portion 32. By doing so, when the ring portion 89 is fitted into the second case portion 32, the housing 80 and the inner case 60 can be correctly positioned relative to the rotor case 30.

[0075] The housing 80 also has a disk-shaped base 83. The support portion 84 is connected to a lower surface 83a of the base 83. The lower surface 83a is in contact with the annular portion 63 of the inner case 60. The diameter of the lower surface 83a is smaller than the outer diameter of the annular portion 63. This allows the outer peripheral edge of the annular portion 63 to extend radially outward from the lower portion of the base 83. This prevents the base 83 from melting due to heat when the annular portion 63 is welded to the rotor case 30.

[0076] The stator unit 8 described above has a configuration in which the peripheral wall portion 61 of the inner case 60 has the through-hole 61a and the support portion 84 of the housing 80 has the protrusion 84a that is disposed in the through-hole 61a, but the present invention is not limited to this configuration. For example, the motor-operated valve 1 may have a stator unit 8B shown in Fig. 7 or a stator unit 8C shown in Fig. 8 instead of the stator unit 8.

[0077] 7, instead of the through holes 61a and the protrusions 84a, a hemispherical recess 61b is provided on the inner circumferential surface of the peripheral wall portion 61, and a hemispherical protrusion 84b that is disposed in the recess 61b is provided on the outer circumferential surface of the support portion 84. For example, the peripheral wall portion 61 has four recesses 61b, and the support portion 84 has four protrusions 84b. The stator unit 8B does not have a ring portion 89. In the stator unit 8B, a hemispherical recess may be provided on the outer circumferential surface of the support portion 84, and a hemispherical protrusion that is disposed in the recess may be provided on the inner circumferential surface of the peripheral wall portion 61.

[0078] Alternatively, in a stator unit 8C shown in FIG. 8 , instead of the through holes 61 a and the protrusions 84 a, an annular recessed groove 61 c extending in the circumferential direction is provided on the inner peripheral surface of the peripheral wall portion 61, and an annular protrusion 84 c extending in the circumferential direction is provided on the outer peripheral surface of the support portion 84 and is disposed in the recessed groove 61 c. For example, the peripheral wall portion 61 has two recessed grooves 61 c, and the support portion 84 has two protrusions 84 c. The stator unit 8C does not have a ring portion 89. In the stator unit 8C, an annular recessed groove extending in the circumferential direction may be provided on the outer peripheral surface of the support portion 84, and an annular protrusion 84 c extending in the circumferential direction is disposed in the recessed groove.

[0079] In these stator units 8B and 8C, the housing body 81 is also integrally formed with the inner case 60 and the stator 90, and the support portion 84 is more firmly connected to the inner case 60.

[0080] Second Embodiment Next, a valve device according to a second embodiment of the present invention will be described with reference to FIG.

[0081] As shown in FIG. 9, the valve device 2 according to the second embodiment includes the motor-operated valve 1 according to the first embodiment and a flow path block 550 .

[0082] The flow path block 550 has a rectangular parallelepiped shape and is made of metal such as an aluminum alloy. The upper surface of the flow path block 550 is a mounting surface 551 on which the motor-operated valve 1 is disposed.

[0083] The flow path block 550 has a first passage 555, a second passage 556, and a mounting hole 557. The mounting hole 557 is disposed in the mounting surface 551. The first passage 555 extends forward from the mounting hole 557. The second passage 556 extends downward from the mounting hole 557.

[0084] The flow path block 550 has a female thread 550f. The female thread 550f is disposed on the inner circumferential surface of the mounting hole 557. The main body member 11 of the motor-operated valve 1 is disposed in the mounting hole 557, and the male thread 11f of the main body member 11 is threadedly engaged with the female thread 550f. The motor-operated valve 1 is attached to the flow path block 550 using a threaded structure by attaching a manufacturing tool to the head portion 11a of the main body member 11 and rotating it around the axis L. The connector portion 87 of the motor-operated valve 1 faces upward. O-rings 558 and 559 seal the space between the main body member 11 and the flow path block 550 in the mounting hole 557. The first passage 555 is connected to the valve chamber 12 of the motor-operated valve 1 via the mounting hole 557 and the first connecting passage 15. The second passage 556 is connected to the valve port 13 of the motor-operated valve 1 via the second connecting passage 16.

[0085] The valve device 2 may have a configuration in which the motor-operated valve 1 does not have a main body member 11, and the rotor case 30 of the motor-operated valve 1 is directly attached to the flow path block 550. In this configuration, the flow path block 550 has the same (including substantially the same) valve chamber, valve port, valve seat, and mounting hole as those of the motor-operated valve 1.

[0086] Furthermore, the valve device 2 may have a configuration in which the flow path block 550 has a plurality of mounting holes 557 arranged on the mounting surface 551, and an electric valve 1 is arranged in each of the mounting holes 557. In this configuration, the connector portions 87 of the plurality of electric valves 1 face the same direction (upward). Therefore, in a system incorporating a valve device 2 of this configuration, it is only necessary to provide space above the valve device 2 for arranging cables connected to the connector portions 87 of the plurality of electric valves 1, and the valve device 2 can be arranged in a relatively small space.

[0087] The valve device 2 also has the same effect as the motor-operated valve 1.

[0088] 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.

[0089] 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.

[0090] REFERENCE SIGNS LIST 1...motor operated valve, 5...valve body assembly, 10...valve body, 11...body member, 20...valve disc, 25...rolling bearing, 30...rotor case, 35...rotor, 50...driving member, 8, 8B, 8C...stator unit, 60...inner case, 61...circumferential wall portion, 61a...through hole, 61b...recess, 61c...recessed groove, 62...bottom wall portion, 63...annular portion, 80...housing, 81...housing body, 82...wall portion, 83...base, 83a...lower surface, 84...support portion, 84a...protrusion, 84b...protrusion, 84c...protrusion, 85...lid body, 86...lid portion, 87...connector portion, 89...ring portion, 90...stator, 98...stepping motor, 100...control device, 2...valve device, 550...flow path block

Claims

1. An electric valve having a valve body assembly and a stator unit, wherein the valve body assembly has a cylindrical rotor case attached to the valve body and a cylindrical magnet rotor placed inside the rotor case, the stator unit has a synthetic resin housing, a metal inner case, and a stator, the inner case has a cylindrical peripheral wall portion, a disk-shaped bottom wall portion connected to a first end of the peripheral wall portion, and an annular portion whose inner peripheral edge is connected to a second end of the peripheral wall portion, the outer peripheral edge of the annular portion is joined to one end of the rotor case, the peripheral wall portion and the bottom wall portion are placed inside the magnet rotor, the housing has a cylindrical support portion placed inside the peripheral wall portion, the stator is embedded in the support portion, and the support portion is molded integrally with the stator and the inner case.

2. The motor-operated valve according to claim 1, wherein the peripheral wall portion has a through hole, and the outer peripheral surface of the support portion is provided with a protrusion that is disposed in the through hole.

3. The motor-operated valve according to claim 2, wherein the housing further has a ring portion disposed on the outside of the peripheral wall portion, the ring portion being connected to the protrusion.

4. The motor-operated valve according to claim 3, wherein the outer diameter of the ring portion is the same as the inner diameter of the rotor case, and the outer peripheral surface of the ring portion contacts the inner peripheral surface of the rotor case.

5. An electric valve as described in claim 1, wherein a recess is provided on the inner surface of the peripheral wall portion and a protrusion is provided on the outer surface of the support portion that is positioned in the recess, or a recess is provided on the outer surface of the support portion and a protrusion is provided on the inner surface of the peripheral wall portion that is positioned in the recess.

6. The motor-operated valve according to claim 1, wherein the housing further has a disk-shaped base, the support portion is connected to one surface of the base, the one surface is in contact with the annular portion, and the diameter of the one surface is smaller than the outer diameter of the annular portion.

7. A valve device comprising the motor-operated valve according to any one of claims 1 to 6 and a flow path block having a mounting surface on which the motor-operated valve is disposed.

8. A method for manufacturing a stator unit having a synthetic resin housing, a metal inner case, and a stator, wherein the inner case has a cylindrical peripheral wall portion, a disk-shaped bottom wall portion connected to a first end of the peripheral wall portion, and an annular portion whose inner peripheral edge is connected to a second end of the peripheral wall portion, the housing has a housing main body having a cylindrical support portion disposed inside the peripheral wall portion, the stator is installed inside the peripheral wall portion and the inner case is installed in a cavity of an injection mold, and the housing main body is molded by injecting synthetic resin into the cavity.

9. A method for manufacturing a stator unit having a synthetic resin housing, a metal inner case, and a stator, wherein the inner case has a cylindrical peripheral wall portion, a disk-shaped bottom wall portion connected to a first end of the peripheral wall portion, and an annular portion whose inner peripheral edge is connected to a second end of the peripheral wall portion, the housing has a housing main body having a cylindrical support portion disposed inside the peripheral wall portion, the stator is installed inside the peripheral wall portion and the inner case is installed in a cavity of a casting mold, and synthetic resin is injected into the cavity to form the housing main body.

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