Electric valve

Abstract

To reduce manufacturing costs of an electric valve.SOLUTION: An electric valve 1 includes: a can 66 which encloses a rotor 60 therein; a screw member 6 positioned at the radial inner side of the can 66 and assembled to a body 200; and an annular member 7 which is assembled to an outer peripheral surface of the screw member 6 and forms an internal space with the can 66 by an opening end of the can 66 being welded thereto. The screw member 6 has a male screw part 10 which may be threadedly engaged with a female screw part 218 provided at an attachment hole 216 of the body 200. The annular member 7 is formed of a material which is the same type with the can 66 and different from the screw member 6. The screw member 6 is fastened to the body 200 to cause the annular member 7 to be fixed to the body 200.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a motor-operated valve, and more particularly to a cost-reducing structure for a motor-operated valve. [Background technology]

[0002] Automotive air conditioners are generally configured with a compressor, a condenser, an expansion device, an evaporator, and other components arranged in a refrigeration cycle. The refrigeration cycle is provided with various control valves, such as an expansion valve as an expansion device, to control the flow of the refrigerant. With the recent spread of electric vehicles, motor-operated valves equipped with a motor as a drive unit are becoming more widely used.

[0003] An electric valve is constructed by assembling a body having a fluid passage and a motor unit (see Patent Document 1). The motor unit has a can for forming a pressure space. The can contains a rotor and defines an internal space where the fluid pressure acts and an external space where it does not act. A screw feed mechanism for converting the rotational motion of the rotor into translational motion is provided inside the can. A valve body is coaxially assembled to the rotor, and the valve body can be displaced in the opening and closing directions of the valve section by operating the screw feed mechanism.

[0004] In manufacturing the motor-operated valve of Patent Document 1, the motor unit is divided into a rotor unit and a stator unit, which are manufactured separately from the viewpoint of improving assembly. The motor-operated valve can be assembled by assembling these units sequentially to the body. The rotor unit includes a screw member having male threads on the top and bottom. The can is assembled to the screw member so as to cover the rotor. The upper male thread is screwed into the female thread of the rotor, so that the screw member rotatably supports the rotor. The lower male thread is screwed into the female thread of the body, so that the rotor unit can be fastened to the body.

[0005] In such motor-operated valves, the can must be non-magnetic because it is interposed between the rotor and the stator. In addition, high pressure resistance is required to separate the pressure space. Furthermore, in order to ensure airtightness of the internal space, it is preferable to perform full-circumference welding along the boundary between the can and the screw member, in which case the can and the screw member must be made of the same type of metal material. On the other hand, since the screw member rotatably supports the rotor, it is preferable that it be made of a material with excellent sliding properties.

[0006] However, it is difficult to satisfy all of these requirements with a single member. Therefore, in the motor-operated valve of Patent Document 1, the screw member is formed by assembling a guide member and a valve housing. The guide member has a male thread portion for supporting the rotor, and the valve housing has a male thread portion for fastening the screw member to the body. The guide member is made of a metal material (brass, etc.) with excellent sliding properties, and the valve housing is made of the same type of metal material (stainless steel, etc.) as the can. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2023-53708 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, stainless steel is generally considered to be difficult to cut because of its high viscosity, which makes it difficult to achieve cutting precision, and because the chips tend to join together, making it necessary to remove them one after another. For this reason, when cutting out valve housings with complex shapes, including male threads, from stainless steel materials (such as bar stock), not only is the yield low, but the processing time is long. As a result, manufacturing costs tend to be high.

[0009] One object of the present invention is to reduce the manufacturing costs of motor-operated valves. [Means for solving the problem]

[0010] The motor-operated valve of one aspect of the present invention includes a body having a fluid passage and containing a valve portion, a valve element for opening and closing the valve portion, a rotor for driving the valve element in the opening and closing direction of the valve portion, a can which is a cylindrical member containing the rotor and defines an internal space in which the pressure of the fluid acts and an external space in which the pressure of the fluid does not act, a screw member located radially inside the can and assembled to the body, an annular member which is assembled to the outer circumferential surface of the screw member and has an open end of the can welded to form an internal space between the can and the screw member, and a stator which is fitted onto the can. The body has a mounting hole communicating with the fluid passage. The screw member has a male screw portion which can be screwed into a female screw portion provided in the mounting hole. The annular member is made of the same material as the can but different from the screw member. The screw member is fastened to the body to fix the annular member to the body.

[0011] According to this embodiment, the screw member and the annular member are made of different materials, and the annular member is assembled to the screw member, and then the can is welded to the annular member. This allows for a high degree of freedom in the selection of materials for the screw member that is not the subject of welding. In other words, a material that is easy to process can be selected for the screw member. Furthermore, by adopting a simple shape for the annular member, the processing cost of the annular member itself can be reduced. This allows for a reduction in the manufacturing cost of the motor-operated valve. Effect of the Invention

[0012] According to the present invention, the manufacturing costs of the motor-operated valve can be reduced. [Brief description of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view illustrating a structure of a motor-operated valve according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing the structure of a valve unit. [Diagram 3] 1A to 1C are diagrams illustrating a method of assembling the motor-operated valve. [Figure 4] 1A to 1C are diagrams illustrating a method of assembling the motor-operated valve. [Diagram 5]FIG. 11 is a cross-sectional view showing a configuration of a motor-operated valve according to a modified example. [Figure 6] 4 is a diagram illustrating a cross-sectional structure of a joint between an annular member and a screw member. FIG. [Figure 7] 1A to 1C are diagrams illustrating a method of assembling the motor-operated valve. [Figure 8] 1A to 1C are diagrams illustrating a method of assembling the motor-operated valve. [Figure 9] FIG. 6 is a cross-sectional view illustrating a configuration of a motor-operated valve according to a second embodiment. [Figure 10] FIG. 10 is an enlarged view of part A in FIG. [Figure 11] FIG. 11 is a cross-sectional view showing a configuration of a motor-operated valve according to a modified example. [Figure 12] FIG. 11 is a cross-sectional view illustrating a configuration of a motor-operated valve according to a third embodiment. [Figure 13] FIG. 13 is an enlarged view of part B in FIG. [Figure 14] FIG. 11 is a cross-sectional view showing a configuration of a motor-operated valve according to a modified example. [Figure 15] FIG. 11 is a cross-sectional view illustrating a configuration of a motor-operated valve according to another modified example. [Figure 16] FIG. 11 is a cross-sectional view illustrating a configuration of a motor-operated valve according to another modified example. [Figure 17] FIG. 11 is a cross-sectional view illustrating a configuration of a motor-operated valve according to another modified example. [Figure 18] FIG. 11 is a cross-sectional view illustrating a configuration of a motor-operated valve according to another modified example. [Figure 19] FIG. 11 is a partially enlarged cross-sectional view showing the configuration of a motor-operated valve according to another modified example. [Figure 20] FIG. 11 is a cross-sectional view illustrating a configuration of a motor-operated valve according to another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, for convenience, the positional relationship of each structure may be expressed based on the illustrated state. In addition, in the following embodiment and its modified examples, substantially the same components are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0015] [First embodiment] FIG. 1 is a cross-sectional view illustrating the structure of a motor-operated valve according to a first embodiment. The motor-operated valve 1 is applied to the refrigeration cycle of an automobile air conditioner (not shown). This refrigeration cycle includes a compressor that compresses the circulating refrigerant, a condenser that condenses the compressed refrigerant, an expansion valve that throttles and expands the condensed refrigerant and sends it out in the form of mist, and an evaporator that evaporates the mist of refrigerant and cools the air in the vehicle cabin with the latent heat of evaporation. The motor-operated valve 1 functions as the expansion valve.

[0016] The motor-operated valve 1 is configured by assembling a valve unit 100 and a passage body 200. The valve unit 100 includes a rotor unit 90 and a stator unit 92. The rotor unit 90 and the stator unit 92 are each fixed to the passage body 200. The stator unit 92 is fixed to the passage body 200 via a connection member 101. The connection member 101 includes a metal plate fixed to the stator unit 92 and a screw for fixing the metal plate to the passage body 200. In this embodiment, the passage body 200 corresponds to the "body" of the present invention.

[0017] The passage body 200 is made of a metal such as an aluminum alloy and has a generally rectangular columnar shape. An inlet port 202, an outlet port 204, an inlet port 206, and an outlet port 208 are provided on the side of the passage body 200. A pipe extending from the condenser side is connected to the inlet port 202, and a pipe connected to the inlet of the evaporator is connected to the outlet port 204. A pipe connected to the outlet of the evaporator is connected to the inlet port 206, and a pipe extending to the compressor side is connected to the outlet port 208.

[0018] The passage body 200 is formed with a first passage 210 connecting the inlet port 202 and the outlet port 204, and a second passage 212 connecting the inlet port 206 and the outlet port 208. The first passage 210 and the second passage 212 function as a "fluid passage". The first passage 210 and the second passage 212 are vertically separated by a partition wall 214. The passage body 200 contains a valve portion of the valve unit 100 in the middle of the first passage 210. At the top of the passage body 200, a mounting hole 216 opens upward. The mounting hole 216 communicates with the first passage 210. A female screw portion 218 (first female screw portion) is formed near the open end of the mounting hole 216.

[0019] The valve unit 100 has a valve body 5 that contains a valve portion. The valve body 5 has a stepped cylindrical shape and is configured by assembling a screw member 6 and a valve seat member 8 one above the other. A seal ring 20 (O-ring) is attached to the outer peripheral surface of the valve seat member 8. A male thread portion 10 (first male thread portion) that can be screwed into a female thread portion 218 is formed on the outer peripheral surface of the screw member 6. When assembling the valve unit 100 to the passage body 200, the valve body 5 is inserted into the mounting hole 216. The male thread portion 10 is screwed into the female thread portion 218, and the valve body 5 is fastened to the passage body 200.

[0020] An annular seal receiving portion 222 (annular groove) is provided on the upper surface of the passage body 200 so as to surround the mounting hole 216, and a seal ring 220 (O-ring) is fitted into the annular seal receiving portion 222. When the valve body 5 is fastened to the passage body 200, the seal ring 220 is interposed between the upper surface of the passage body 200 and the valve body 5. The seal ring 220 regulates leakage of refrigerant from the inside of the passage body 200 to the outside. The seal ring 220 seals between an upstream passage 230 and a downstream passage 232 of the valve portion.

[0021] FIG. 2 is a cross-sectional view showing the structure of the valve unit 100. The valve unit 100 is configured by coaxially assembling a rotor unit 90 and a stator unit 92. The rotor unit 90 and the stator unit 92 are not directly fixed to each other, but are indirectly fixed to each other by being respectively fixed to a passage body 200 (see FIG. 1).

[0022] The rotor unit 90 has a valve body 5. The valve body 5 is formed by coaxially assembling a screw member 6 made of resin and a valve seat member 8 made of metal. The screw member 6 has an annular member 7 coaxially assembled to the outer circumferential surface of the middle part in the axial direction. The screw member 6 is in the form of a stepped cylinder whose diameter is gradually reduced toward the top of the annular member 7 and also gradually reduced toward the bottom of the annular member 7. The annular member 7 is integrated with the screw member 6 by injection molding (also called "insert molding" or "mold molding") of a resin material. A male thread portion 10 is formed in the screw member 6 at a position close to the annular member 7. An inlet port 26 is provided on the side surface of the lower part of the screw member 6. The inlet port 26 is formed on the side surface of the cylindrical part of the screw member 6 and functions as a "communication hole" that forms a part of the fluid passage.

[0023] The annular member 7 is a disk-shaped press-formed product (plate) obtained by punching a metal material (plate material) made of stainless steel (hereinafter referred to as "SUS"). As shown in Fig. 1, when the screw member 6 is screwed into the mounting hole 216, the annular member 7 abuts against the passage body 200 in the axial direction, thereby restricting the insertion amount of the valve body 5 into the mounting hole 216.

[0024] The screw member 6 has an annular flange portion 9 extending radially outwardly directly above the annular member 7. The flange portion 9 abuts against the upper surface of the annular member 7, and forms an annular step 12 between the annular member 7 and the flange portion 9 at its outer circumferential edge. A concave fitting portion 14 is formed on the outer circumferential surface of the screw member 6. The annular member 7 is partially embedded in the screw member 6 so that its inner circumferential edge fits into the concave fitting portion 14. The annular member 7 is stably fixed to the screw member 6 by being integrated with the screw member 6 at its upper surface and inner circumferential edge. The flange portion 9 functions as a "support portion" or "locking portion" that supports the annular member 7 from above. The lower end opening of the can 66 fits into the step 12, ensuring the coaxiality of the can 66 and the annular member 7.

[0025] A valve seat member 8 is attached to the lower end opening of the screw member 6. The valve seat member 8 is in the shape of a stepped cylinder, and a seal receiving portion 18 consisting of an annular groove is formed on the outer circumferential surface of the lower part of the valve seat member 8, into which a seal ring 20 is fitted. The upper part of the valve seat member 8 is press-fitted into the lower end part of the screw member 6, whereby the valve seat member 8 is fixed coaxially to the screw member 6.

[0026] The inner diameter of the upper part of the valve seat member 8 is reduced to form a valve hole 22, and a valve seat 24 is formed at the upper opening of the valve hole 22. In this embodiment, the valve seat member 8 is made of SUS, but a material with excellent wear resistance, such as brass, may also be selected.

[0027] An outlet port 28 is provided at the bottom of the valve seat member 8. The inlet port 26 communicates with an introduction port 202, and the outlet port 28 communicates with a discharge port 204 (see FIG. 1). An internal passage that communicates between the inlet port 26 and the outlet port 28 is formed inside the valve body 5. This internal passage functions as a "fluid passage." A valve chamber 30 is formed inside the screw member 6. The inlet port 26 and the outlet port 28 communicate with each other via the valve chamber 30.

[0028] An actuating rod 32 extending from the rotor 60 of the rotor unit 90 is inserted into the inside of the valve body 5. The actuating rod 32 passes through the valve chamber 30. The actuating rod 32 is obtained by cutting a bar made of a non-magnetic metal, and a needle-shaped valve element 34 is provided integrally at its lower part. The valve element 34 is attached to and detached from the valve seat 24 from the valve chamber 30 side to open and close the valve portion.

[0029] The screw member 6 is obtained by injection molding of a resin material. A male screw 38 (third screw portion) is formed on the outer peripheral surface of the upper part of the screw member 6. The screw member 6 supports the actuation rod 32 on its inner peripheral surface so that it can slide in the axial direction, while supporting the rotating shaft 62 of the rotor 60 on its outer peripheral surface so that it can rotate and slide. The rotating shaft 62 is made of a non-magnetic metal.

[0030] The rotor 60 of the rotor unit 90 and the stator 64 of the stator unit 92 constitute a two-phase stepping motor. The rotor unit 90 has a cylindrical can 66 with a bottom, and the rotor 60 is disposed inside the can 66. The stator 64 is disposed outside the can 66. The can 66 is a cylindrical member with a bottom that covers the space in which the valve body 34 and its drive mechanism are disposed and contains the rotor 60, and defines an inner pressure space (internal space) where the pressure of the refrigerant acts and an outer non-pressurized space (external space) where it does not act.

[0031] The can 66 is made of a non-magnetic metal (SUS in this embodiment), and its lower end is fitted onto the flange portion 9, with its lower end face abutting against the upper face of the annular member 7. The valve body 5 and the can 66 are fixed together by welding (full-circumference welding) along the boundary between the can 66 and the annular member 7 (not shown), thereby ensuring airtightness (seal) between them. The above-mentioned pressure space is formed between the can 66 and the annular member 7.

[0032] The stator 64 is constructed by assembling a bobbin 70 around which a coil 68 is wound to a yoke 72 having a plurality of pole teeth. The stator 64 is contained in a case 76. The case 76 is obtained by injection molding of a corrosion-resistant resin material. The stator 64 is covered with the molded resin by the injection molding. The case 76 is made of the molded resin. The stator unit 92 is an integrated part of the stator 64 and the case 76 (a molded product in this embodiment). The stator unit 92 has a hollow structure, and is assembled to the rotor unit 90 with the stator 64 coaxially inserted through the can 66. The welded portion between the can 66 and the valve body 5 is located inside the case 76.

[0033] The rotor 60 includes a cylindrical rotor core 102 attached to the rotating shaft 62, a rotor magnet 104 attached to the outer circumferential surface of the rotor core 102, and a sensor magnet 106 attached to the upper end surface of the rotor core 102. The sensor magnet 106 has an annular shape and is attached coaxially to the rotor core 102. The rotor magnet 104 is magnetized (magnetized) into multiple poles in its circumferential direction. The sensor magnet 106 is also magnetized (magnetized) into multiple poles.

[0034] The rotating shaft 62 is a cylindrical shaft with a bottom. The rotating shaft 62 is fitted onto the screw member 6 with its open end facing down. A female screw 108 (second screw portion) is formed on the inner peripheral surface of the lower part of the rotating shaft 62, and meshes with the male screw 38 of the screw member 6. A screw feed mechanism 109 using these screw portions converts the rotational motion of the rotor 60 into axial motion of the actuating rod 32. This causes the valve body 34 to move (rise and fall) in the axial direction, that is, in the opening and closing direction of the valve portion. In this embodiment, the rotating shaft 62 and the actuating rod 32 constitute the "actuating member."

[0035] The upper part of the actuation rod 32 is reduced in diameter, and the reduced diameter part 110 penetrates the bottom part 112 of the rotary shaft 62. An annular stopper 114 is fixed to the tip part of the reduced diameter part 110. Meanwhile, a spring 116 that urges the actuation rod 32 downward (i.e., in the valve closing direction) is interposed between the base end of the reduced diameter part 110 and the bottom part 112. With this configuration, when the valve is opened, the actuation rod 32 is displaced integrally with the rotor 60 in such a manner that the stopper 114 is engaged with the bottom part 112. Meanwhile, when the valve is closed, the spring 116 is compressed by the reaction force that the valve body 34 receives from the valve seat 24. The elastic reaction force of the spring 116 at this time can press the valve body 34 against the valve seat 24, improving the seating performance (valve closing performance) of the valve body 34.

[0036] The stator unit 92 has a circuit board 118 on the outside of the can 66. The circuit board 118 is fixed inside the case 76. Various circuits functioning as a control unit and a communication unit are mounted on the lower surface of the circuit board 118. Specifically, a drive circuit for driving the motor, a control circuit (microcomputer) for outputting a control signal to the drive circuit, a communication circuit for the control circuit to communicate with an external device, a power supply circuit for supplying power to each circuit and the motor (coil), etc. are mounted. The upper end of the case 76 is closed by a resin cover 77. The circuit board 118 is disposed in the space below the cover 77 of the case 76. An annular seal receiving portion 19 is provided on the inner peripheral surface near the lower end of the case 76, and a seal ring 21 (O-ring) is fitted into the seal ring 21. The seal ring 21 is interposed between the case 76 and the can 66 to prevent moisture from entering the stator unit 92 from the outside.

[0037] A magnetic sensor 119 is provided on the surface of the circuit board 118 facing the sensor magnet 106. The magnetic sensor 119 faces the sensor magnet 106 in the axial direction via the bottom end wall of the can 66. The magnetic flux generated by the sensor magnet 106 changes as the rotor 60 rotates. The magnetic sensor 119 detects the amount of displacement of the rotor 60 (the rotation angle of the rotor 60 in this embodiment) by detecting this change in magnetic flux. The control unit calculates the axial position of the valve body 34 and therefore the valve opening degree based on the amount of displacement of the rotor 60.

[0038] A terminal 120 connected to the coil 68 extends from the bobbin 70 and is connected to a circuit board 118. A power supply terminal, a ground terminal, and a communication terminal (collectively referred to as "connection terminals 122") extend from the circuit board 118 and are each drawn out to the outside through a side wall of the case 76. A connector portion 124 is integrally provided on the side of the case 76, and the connection terminal 122 is disposed inside the connector portion 124.

[0039] 3 and 4 are diagrams illustrating a method for assembling the motor-operated valve 1. FIG. When assembling the motor-operated valve 1, the passage body 200, the rotor unit 90, and the stator unit 92 shown in Fig. 1 are each produced separately. Then, the rotor unit 90 and the stator unit 92 are each fixed to the passage body 200.

[0040] In the manufacture of the rotor unit 90, the annular member 7 is set in a die (not shown) and injection molding of a resin material is performed. As a result, the screw member 6 with the annular member 7 insert-molded is obtained. The valve seat member 8 is coaxially press-fitted into the screw member 6 to obtain the valve body 5 (FIG. 3(A)). Next, the rotor 60 with the actuation rod 32 assembled thereto is coaxially assembled to the valve body 5. At this time, the female thread 108 is screwed into the male thread 38 to form the screw feed mechanism 109. Then, the can 66 is assembled to the valve body 5 so as to cover the rotor 60 from above (FIG. 3(B)), and a full circumference weld W is performed along the boundary between the can 66 and the annular member 7 (FIG. 3(C)). As a result, the rotor unit 90 is obtained.

[0041] Next, the rotor unit 90 is assembled to the passage body 200 (FIG. 4(A)). A seal ring 220 is fitted to the passage body 200, and a seal ring 20 is fitted to the rotor unit 90. Then, the rotor unit 90 is inserted into the mounting hole 216 from the tip side of the valve body 5. At this time, the male thread portion 10 is screwed into the female thread portion 218, and the rotor unit 90 is assembled to the passage body 200 while being rotated.

[0042] By fastening the rotor unit 90 to the passage body 200, the seal ring 220 is compressed in the axial direction and crushed appropriately, so that the sealing function can be effectively exerted (FIG. 4(B)). The sealing function of the seal ring 20 is also effectively exerted. Then, the stator unit 92 is assembled to the rotor unit 90 while being coaxially inserted around the can 66 (FIG. 4(C)). Prior to this assembly, the metal plate of the connecting member 101 is fixed to the case 76 of the stator unit 92 by welding or the like.

[0043] The metal plate is fastened to the passage body 200 by screws (not shown), whereby the stator unit 92 is fixed to the passage body 200. As a result, the rotor unit 90 and the stator unit 92 are also indirectly fixed to each other.

[0044] Returning to FIG. 1, the motor-operated valve 1 configured as above functions as an electric expansion valve capable of adjusting the valve opening degree by controlling the drive of the rotor unit 90. That is, based on a command from an external device (not shown), the control unit sets a control amount (the number of drive steps of the motor) for realizing a target opening degree, and outputs a drive signal for realizing this to the drive circuit. The drive circuit supplies a two-phase drive current (drive pulse) to each coil 68 at a set timing. This causes the rotor 60 to rotate with high resolution. At this time, if the valve body 34 is in an open state separated from the valve seat 24, the stopper 114 abuts against the rotating shaft 62 due to the biasing force of the spring 116, and the operating rod 32 and therefore the valve body 34 move integrally with the rotor 60.

[0045] The rotor 60 moves in the vertical direction by a screw feed mechanism 109 between the rotor 60 and the screw member 6. The valve element 34 translates in the opening and closing direction of the valve section, and the opening of the valve section is adjusted to a set opening. The screw feed mechanism 109 converts the rotational motion of the rotor 60 about the axis into axial motion (linear motion) of the operating rod 32, and drives the valve element 34 in the opening and closing direction of the valve section. When the motor-operated valve 1 functions as an expansion valve, the valve section is controlled to a small opening. The control section detects the rotational angle of the sensor magnet 106 (the rotational angle of the rotor 60) based on the detection signal of the magnetic sensor 119, and can calculate the valve opening.

[0046] As described above, in this embodiment, the screw member 6 and the can 66, which have a complex shape, are not directly welded together, but the annular member 7, which has a simple shape, is interposed between them. The annular member 7 is obtained by press forming (punching) a metal plate. Therefore, even if the annular member 7 is made of the same type of difficult-to-cut material as the can 66, the processing cost can be suppressed. Meanwhile, although the screw member 6 has a complex shape with male threads on the top and bottom, it can be easily manufactured by injection molding of a resin material. As a result, the manufacturing cost of the motor-operated valve 1 can be reduced.

[0047] [Variations] FIG. 5 is a cross-sectional view showing the configuration of a motor-operated valve according to a modified example. The motor-operated valve of this modification differs from the first embodiment in that the screw member 126 is made of a metal material and is separated from the valve seat member 128. The valve seat member 128 has a valve hole 22 and a valve seat 24, and is press-fitted into the passage body 200. In this modification, the valve seat member 128 is made of SUS, which has excellent wear resistance, but brass may also be used.

[0048] The screw member 126 is obtained by cutting a tube material made of a non-magnetic metal into a stepped cylindrical shape. A male screw 38 is formed on the upper outer peripheral surface of the screw member 126, and a male screw portion 10 is formed on the lower outer peripheral surface. In this modification, SUS is used as the material for the annular member 107, but brass is used as the material for the screw member 126. Brass has better machinability than SUS (high-precision cutting can be performed in a relatively short time). The annular member 107 is press-fitted into the screw member 126 directly below the flange portion 9.

[0049] FIG. 6 is a diagram showing a cross-sectional structure of a joint between the annular member 107 and the screw member 126, and corresponds to a cross section taken along the line AA in FIG. The screw member 126 has a stepped cylindrical shape as a whole, but a pair of parallel flat surfaces 130 are formed by a so-called D-cut on the side surface of the fitting portion with the annular member 107. Meanwhile, the annular member 107 is provided with an insertion hole 132 having a shape complementary to a cross section including the flat surfaces 130 of the screw member 126. Therefore, when the annular member 107 is fitted onto the screw member 126, the relative displacement (rotation) of the two about the axis is restricted. In other words, this D-cut structure functions as a rotation prevention structure for the annular member 107 relative to the screw member 126.

[0050] 7 and 8 are diagrams showing a method of assembling the motor-operated valve. In this modification, as described above, the screw member 126 is machined, while the annular member 107 is press-formed. Then, the annular member 107 is press-fitted while being inserted onto the screw member 126 (FIG. 7(A)). This press-fitting may be temporary. In other words, there may be a gap S between the lower surface of the flange portion 9 and the upper surface of the annular member 107 (see FIG. 7(B)).

[0051] The actuation rod 32 and the rotor 60 are attached to the assembly of the screw member 126 and the annular member 107, and the can 66 is then attached (FIG. 7(B)). Then, a full circumference weld W is applied along the boundary between the can 66 and the annular member 107 (FIG. 7(C)). This results in a rotor unit 190.

[0052] Next, the valve seat member 128 and the rotor unit 190 are successively assembled to the passage body 200 (FIG. 8(A)). After the seal ring 220 is fitted to the passage body 200, the rotor unit 190 is inserted into the mounting hole 216 from the tip side of the screw member 126. At this time, the male thread portion 10 is screwed into the female thread portion 218, and the rotor unit 190 is assembled to the passage body 200 while rotating it by gripping the can 66. The above-mentioned gap S may be present between the flange portion 9 and the annular member 107.

[0053] Even if the lower surface of the annular member 107 abuts against the upper surface of the passage body 200, the rotor unit 190 can continue to rotate as long as there is a gap S between the flange portion 9 and the annular member 107. Since there is the above-mentioned rotation prevention structure between the annular member 107 and the screw member 126, the screw member 126 can be rotated together with the rotor unit 190 and further screwed into the passage body 200. As a result, the screw member 126 is displaced downward relative to the annular member 107, and the gap S can be eliminated. That is, the annular member 107 can be completely pressed into the screw member 126 (FIG. 8(B)). As the male screw portion 10 is screwed into the female screw portion 218, the annular member 107 is sandwiched between the flange portion 9 and the passage body 200, and the rotor unit 190 is firmly fixed to the passage body 200.

[0054] Then, similarly to the above embodiment, the stator unit 92 is coaxially inserted around the can 66 and assembled to the rotor unit 190 (FIG. 8(C)). The stator unit 92 is fixed to the passage body 200 by fastening the connection member 101 to the passage body 200 with screws (not shown).

[0055] As described above, in this modification, the screw member 126 is also made of a metal material, but one that has better machinability than the annular member 107 is used. Specifically, a metal material with a higher machinability index than the annular member 107 is selected as the material for the screw member 126. The "machinability index" is an index that indicates the ease or difficulty of cutting a metal material, and specifically refers to a value that indicates the ease of cutting a material compared to sulfur free-cutting steel (AISI-B1112) (see, for example, JP 2005-335091 A). The higher the machinability index of a material, the easier it is to cut.

[0056] That is, since the annular member 107 is to be welded, it is necessary to use the same difficult-to-cut material as the can 66, but by giving it a simple structure that can be obtained by press processing, processing is made easier. On the other hand, for the screw member 126, which has the male threads 38, 10 integrally and has a complex shape, the processing burden is reduced by using a material with a high machinability index. As a result, the manufacturing cost of the motor-operated valve can be reduced.

[0057] [Second embodiment] Fig. 9 is a cross-sectional view showing the configuration of a motor-operated valve according to a second embodiment of the present invention, and Fig. 10 is an enlarged view of a portion A in Fig. 9. 9, the motor-operated valve 201 is different from the first embodiment in that it includes a large-diameter first valve 250 and a small-diameter second valve 252, and these valves are driven to open and close by a shared motor unit 254. The motor-operated valve 201 functions as an on-off valve by opening and closing the first valve 250, and functions as an expansion valve by adjusting the opening degree of the second valve 252.

[0058] The motor-operated valve 201 is configured by assembling a motor unit 254 and a valve body 260 in the axial direction. The motor unit 254 includes a rotor unit 290 and a stator unit 92. The motor-operated valve 201 has a so-called cartridge structure in which the valve body 260 is attached to and detached from an attachment object (such as a piping body or a piping block) by being inserted and removed from a mounting hole of the attachment object. The annular member 7 is integrated with the screw member 226 by injection molding of a resin material. A male screw portion 10 is formed at the lower part of the screw member 226. In this embodiment, the valve body 260 corresponds to the "body" of the present invention.

[0059] The valve body 260 is obtained by cutting a metal material (brass in this embodiment) having a higher machinability index than the annular member 107, and has a stepped cylindrical shape. A female thread portion 218 is formed on the upper inner circumferential surface of the valve body 260. The male thread portion 10 of the screw member 226 is screwed into the female thread portion 218 and fastened, thereby fixing the rotor unit 290 to the valve body 260. In addition, the stator unit 92 is fixed to the valve body 260 via a connecting member 251. A valve body 270 (first valve body) is disposed inside the valve body 260. A guide hole 268 is formed by the inner circumferential surface of the center part of the valve body 260, and the upper half of the valve body 270 is slidably supported in the guide hole 268 and driven along the axial direction.

[0060] A ring-shaped valve seat forming member 262 is coaxially press-fitted into the lower end of the valve body 260. A valve hole 264 (first valve hole) is provided inside the valve seat forming member 262, and a valve seat 266 (first valve seat) is formed at the upper end opening thereof.

[0061] A recessed fitting portion 240 into which a pin (not shown) fits for fixing the motor-operated valve 201 to an attachment target is provided on the outer peripheral surface of the upper portion of the valve body 260. Furthermore, seal rings 242, 244 (O-rings) that perform a sealing function when the motor-operated valve 201 is attached to an attachment target are fitted on the outer peripheral surface of the central portion and the outer peripheral surface of the lower portion of the valve body 260.

[0062] 10, the valve element 270 has a bottomed cylindrical shape, and is slidably supported in the guide hole 268. The valve element 270 opens and closes the first valve 250 by being attached to and detached from the valve seat 266 from the downstream side. Meanwhile, a valve hole 22 (second valve hole) is formed in the middle of the internal passage of the valve element 270. A valve seat 24 (second valve seat) is formed at the upstream opening of the valve hole 22.

[0063] The valve element 270 has a bottomed cylindrical shape with a sufficient thickness at the bottom. A back pressure chamber 274 is formed above the valve element 270. The back pressure chamber 274 is a space surrounded by the valve body 260 and the valve element 270. A valve chamber 276 is formed inside the valve element 270 (above the bottom). A disk-shaped operating connection member 278 is fixed to the upper part of the valve element 270. The operating connection member 278 has an insertion hole 287 at its center. The operating rod 32 coaxially passes through the insertion hole 287. In addition, a plurality of communication holes 289 are provided near the periphery of the operating connection member 278. The insertion hole 287 and the communication hole 289 communicate the valve chamber 276 and the back pressure chamber 274.

[0064] A radially protruding locking portion 284 is provided on the actuation rod 32 slightly above the valve body 34. The locking portion 284 is formed of, for example, an E-ring. A spring 282 (biasing member) is interposed between the screw member 226 and the operation connecting member 278. The biasing force of the spring 282 is transmitted to the valve body 270 via the operation connecting member 278. When the valve body 34 is opened, the locking portion 284 is displaced relative to the valve body 270 and comes into contact with the bottom surface of the operation connecting member 278 to push it up, thereby operating the valve body 270 in the valve opening direction.

[0065] A plurality of communication holes 288 (small holes) are provided through the bottom of the valve body 270 in parallel with the axis. The lower end openings of these communication holes 288 serve as the inlet port 26. The communication holes 288 communicate the upstream side of the valve seat 266 in the valve hole 264 with the valve chamber 276. The communication holes 288, the valve chamber 276, the insertion hole 287, and the communication holes 289 form a "communication passage" that communicates the upstream side of the valve seat 266 with the back pressure chamber 274. In addition, a communication hole 292 extending perpendicular to the axis is provided in the bottom of the valve body 270 and communicates with the valve hole 22. The communication hole 292 has an outlet port 28. A seal ring 272 (O-ring) is fitted to the upper part of the valve body 270 to regulate the flow of the refrigerant through the gap between the valve body 260 and the valve body 270.

[0066] In this embodiment as well, the annular member 7 is insert molded into the screw member 226. The valve body 260 and the can 66 are fixed together by performing full-circumference welding along the boundary between the can 66 and the annular member 7, ensuring a seal between them. An annular seal receiving portion 222 is provided on the upper surface of the valve body 260, and a seal ring 220 is fitted into it. The screw member 226 is fastened to the valve body 260, ensuring a seal between the annular member 7 and the valve body 260.

[0067] Returning to Fig. 9, the motor-operated valve 201 configured as above operates as follows. When the motor unit 254 is operated to open the valve and the actuation rod 32 is actuated upward, the valve body 34 separates from the valve seat 24. This allows the communication hole 288, the valve chamber 276, the valve hole 22, and the communication hole 292 to communicate with each other (see Fig. 10). The refrigerant from the upstream side flows through the internal passage of the valve body 270 and is discharged to the downstream side via the second valve 252. At this time, the second valve 252 can be adjusted to a predetermined opening degree to function as an expansion valve.

[0068] When the actuating rod 32 is further actuated in the valve opening direction, the locking portion 284 engages with the actuating connection member 278, and the actuating rod 32 and the valve body 270 are operatively connected. Then, the actuating rod 32 pulls up the valve body 270 against the biasing force of the spring 282. This causes the valve body 270 to separate from the valve seat 266, and the first valve 250 opens. The refrigerant flows downstream via both the first valve 250 and the second valve 252. At this time, a large flow rate of refrigerant can be allowed to flow, but the flow rate can be adjusted by the opening degree of the first valve 250.

[0069] When the motor unit 254 is operated to close the valve, the actuating rod 32 is actuated downward, in the opposite manner to the above. At this time, the valve body 270 is actuated in the valve closing direction while maintaining the operative connection with the actuating rod 32 due to the biasing force of the spring 282. First, the valve body 270 is seated on the valve seat 266, and the first valve 250 is in the valve closed state. When the actuating rod 32 is further actuated in the valve closing direction, the locking portion 284 is disengaged from the operative connection member 278, and the operative connection between the actuating rod 32 and the valve body 270 is released. Thereafter, the valve body 34 is seated on the valve seat 24, and the second valve 252 is in the valve closed state.

[0070] In this embodiment, the screw member 226 and the annular member 7 are also made of different materials, and the annular member 7, which is insert-molded into the screw member 226, is welded to the can 66. Therefore, the same effects as in the first embodiment can be obtained.

[0071] [Variations] FIG. 11 is a cross-sectional view showing the configuration of a motor-operated valve according to a modified example. The motor-operated valve of this modification differs from the second embodiment in that the screw member 227 is obtained by cutting a metal material. As in the modification of the first embodiment, the annular member 207 is press-fitted into the lower part of the screw member 227. The screw member 227 has a flange portion 209 that faces the annular member 207 in the axial direction. The flange portion 209 functions as a "locking portion." A rotation prevention structure is provided between the screw member 227 and the annular member 207 by a D cut. In this modification, SUS is used as the material for the annular member 207, but brass, which has excellent machinability, is used as the material for the screw member 227.

[0072] The peripheral portion of the upper surface of the annular member 207 is cut out to form an annular step 12. The lower end opening of the can 66 is fitted into the step 12. Then, the annular member 207 and the can 66 are welded all around along the boundary therebetween.

[0073] In this modification, the material of the screw member 227 has a higher machinability index and is superior in machinability than the annular member 207. Therefore, the same effects as those of the modification of the first embodiment can be obtained.

[0074] [Third embodiment] Fig. 12 is a cross-sectional view showing the configuration of a motor-operated valve according to a third embodiment, and Fig. 13 is an enlarged view of a portion B in Fig. 12. 12, in the motor-operated valve 301, a screw feed mechanism 309 is configured by a female screw 318 formed in a screw member 306 and a male screw 338 formed in an actuation rod 332. In addition, the actuation rod 332 is fixed to a rotor 360. This embodiment differs from the first embodiment in these respects.

[0075] The motor-operated valve 301 is configured by assembling a valve unit 300 and a passage body 203. The valve unit 300 includes a rotor unit 390 and a stator unit 392. The rotor unit 390 and the stator unit 392 are each fixed to the passage body 203. The passage body 203 does not have a second passage as in the first embodiment. The stator unit 392 has a configuration substantially similar to that of the stator unit 92 of the first embodiment, except that it does not have a magnetic sensor. In this embodiment, the passage body 203 corresponds to the "body" of the present invention.

[0076] As shown in Fig. 13, the screw member 306 and the valve seat member 308 are coaxially assembled. In this embodiment, the screw member 306 is made of brass, and the valve seat member 308 is made of SUS. The screw member 306 includes a first member 310 and a second member 312. The first member 310 has a stepped cylindrical shape, with an inner diameter that is smaller at the upper portion and an outer diameter that is slightly smaller at the lower portion. A female thread 318 is formed on the inner peripheral surface of the upper portion. A male thread 320 is formed on the outer peripheral surface of the lower portion.

[0077] The second member 312 has a stepped cylindrical shape, and has a male thread portion 10 on its upper outer peripheral surface and a female thread 322 on its upper inner peripheral surface. An annular locking portion 324 protruding radially inward is provided on the inner peripheral surface of the axial center of the second member 312. The annular member 307 is made of the same material as the annular member 7 of the first embodiment, and is coaxially assembled to the outer peripheral surface of the first member 310. The lower portion of the first member 310 is inserted into the upper portion of the second member 312. The second member 312 is coaxially fastened to the first member 310 by screwing the female thread 322 into the male thread 320.

[0078] More specifically, the annular member 307 is inserted into the first member 310 from below, and then the second member 312 is assembled to the first member 310 from below. At this time, by fastening the second member 312 to the first member 310, the annular member 307 can be sandwiched between a step portion 352 of the first member 310 and an upper end portion of the second member 312. The step portion 352 is located at the base end of a small diameter portion 350, the outer diameter of which is reduced at the bottom of the first member 310, and functions as a "locking portion." By assembling the first member 310 and the second member 312 in this manner, the annular member 307 can be stably fixed coaxially to the screw member 306.

[0079] The valve seat member 308 is cylindrical with a bottom, and has a valve hole 22 and a valve seat 24 formed in its lower part. A seal ring 20 is fitted onto the outer peripheral surface of the lower part of the valve seat member 308. The valve seat member 308 has an upper part inserted into the lower part of the second member 312 and is coaxially fixed to the screw member 306. The upper end of the valve seat member 308 is engaged with an engaging portion 324, thereby restricting the amount of insertion. The lower end of the second member 312 is slightly crimped inwardly, thereby fixing the valve seat member 308 to the second member 312.

[0080] An inlet port 26 is provided on the side surface of the valve seat member 308. The inlet port 26 is formed on the side surface of the cylindrical portion of the valve seat member 308, and forms part of a fluid passage. In addition, a communication hole 330 that communicates between the inside and the outside is also provided on the side surface of the first member 310. With this configuration, the pressure of the fluid introduced into the valve chamber 30 via the inlet port 26 is also led to the internal space of the can 66 via the communication hole 330.

[0081] An actuation rod 332 is provided so as to coaxially penetrate the screw member 306. A male thread 338 is formed on the outer peripheral surface of the upper half of the actuation rod 332, and engages with the female thread 318 of the first member 310. In this embodiment as well, the female thread portion 218 functions as the "first female thread portion", and the male thread portion 10 functions as the "first male thread portion". The male thread 338 functions as the "second thread portion", and the female thread 318 functions as the "third thread portion". A spring 334 (functioning as a "biasing member") that biases the valve body 34 in the valve closing direction is interposed between the first member 310 and the actuation rod 332.

[0082] The rotor 360 includes a rotor core 302 and a rotor magnet 304, but is not provided with a sensor magnet as in the first embodiment. The rotor magnet 304 is cylindrical, and its upper end is fixed so as to fit into the outer circumferential surface of the rotor core 302. With this configuration, a relatively large annular space S1 is formed between the inner circumferential surface of the rotor magnet 304 and the outer circumferential surface of the operating rod 332.

[0083] The upper end of the actuation rod 332 is press-fitted along the axis of the rotor core 302 and is coaxially fixed to the rotor 360. The actuation rod 332 is one aspect of the “actuation member” and functions as the rotation shaft of the rotor 360.

[0084] In this embodiment, the annular member 307 is also assembled to the screw member 306. The screw member 306 and the can 66 are fixed together by performing full circumference welding along the boundary between the can 66 and the annular member 307, and a seal is secured between them. In addition, a seal ring 220 is interposed between the upper surface of the passage body 203 and the lower surface of the annular member 307. The screw member 306 is fastened to the passage body 203, and a seal is secured between the annular member 307 and the passage body 203. The screw member 306 and the annular member 307 are made of different materials, and the annular member 307 fixed to the screw member 306 is welded to the can 66. Therefore, the same effect as in the first embodiment can be obtained.

[0085] [Variations] FIG. 14 is a cross-sectional view showing the configuration of a motor-operated valve according to a modified example. The motor-operated valve of this modification differs from the third embodiment in that the screw member 406 is a single member. The screw member 406 and the valve seat member 308 are coaxially assembled. The screw member 406 is made of brass, for example, and has a structure similar to that of the first member 310 and the second member 312 of the third embodiment, which are integrally molded. The annular member 307 is press-fitted onto the outer circumferential surface of the screw member 406.

[0086] In this modification as well, a material having a higher machinability index and better machinability than the annular member 307 is used as the material for the screw member 406. Therefore, the same effects as those of the above embodiment can be obtained.

[0087] FIG. 15 is a cross-sectional view showing the configuration of a motor-operated valve according to another modified example. The motor-operated valve 501 of this modification differs from the third embodiment in that it has a cartridge structure. The valve body 505 is formed by coaxially assembling a valve housing 510 and a valve seat member 308. The upper part of the valve seat member 308 is inserted into the lower part of the valve housing 510. The lower end opening of the valve housing 510 is crimped inwardly to fix the valve seat member 308 to the valve housing 510. The stator unit 392 is fixed to the valve housing 510 via the connecting member 251. The motor-operated valve 501 is attached to and detached from the passage body 205 by inserting and removing the valve body 505 into and from the mounting hole 516 of the passage body 205.

[0088] A cover member 560 for preventing the seal ring 21 from falling off is attached to the underside of the stator unit 392. The cover member 560 is a stepped annular member made of resin, and its upper end is fitted directly below the seal ring 21, that is, in the gap between the inner peripheral surface of the case 76 and the outer peripheral surface of the can 66.

[0089] The passage body 205 has an inlet port 202 on one side and an outlet port 204 on the bottom. A fluid passage 211 is formed to connect the inlet port 202 and the outlet port 204. A mounting hole 516 communicates with the fluid passage 211.

[0090] The screw member 506 has approximately the same shape as the first member 310 of the third embodiment (see FIG. 13). An internal thread 318 is formed on the upper inner peripheral surface of the screw member 506, and an external thread portion 10 is formed on the lower outer peripheral surface. The valve housing 510 is in the form of a stepped cylinder having an outer diameter approximately equal to that of the annular member 307, and an internal thread portion 218 is formed on the upper inner peripheral surface thereof. By screwing the external thread portion 10 into the internal thread portion 218, the screw member 506 and the annular member 307 can be coaxially fixed to the valve body 505.

[0091] A recessed fitting portion 540 is provided on the upper inner peripheral surface of the mounting hole 516, and a recessed fitting portion 542 is provided on the upper outer peripheral surface of the valve housing 510. When the valve body 505 is assembled into the mounting hole 516, the recessed fitting portion 540 and the recessed fitting portion 542 are arranged opposite each other as shown in the figure, forming an insertion hole having a circular cross section. The valve body 505 can be fixed to the passage body 205 by fitting a pin 550 into this insertion hole.

[0092] A seal ring 520 that provides a sealing function when the motor-operated valve 501 is attached to the passage body 205 is fitted onto the outer peripheral surface of the lower part of the valve housing 510. The annular member 307 is press-fitted onto the screw member 506 in a manner that it is fitted onto the screw member 506. In this embodiment, the valve body 505 corresponds to the "body" of the present invention. The internal passage of the valve body 505 that communicates between the inlet port 26 and the valve hole 22 forms a part of the fluid passage 211.

[0093] A seal ring 220 is interposed between the upper surface of the valve housing 510 and the lower surface of the annular member 307. A seal is ensured between the annular member 307 and the valve body 505 by fastening the screw member 506 to the valve housing 510. In this modification as well, a material having a higher machinability index and superior machinability than the annular member 307 is used as the material for the screw member 506 and the valve housing 510. Therefore, the same effects as in the above embodiment can be obtained.

[0094] FIG. 16 is a cross-sectional view showing the configuration of a motor-operated valve according to another modified example. The motor-operated valve 601 of this modification is common to the second embodiment in that it includes a large-diameter first valve 250 and a small-diameter second valve 252 (see FIG. 9), but is different from the third embodiment. The motor-operated valve 601 has a cartridge structure and is detachably attached to a passage body 606.

[0095] The valve body 605 has a structure similar to that of the valve body 260 of the second embodiment, but is not provided with the concave fitting portion 240. A female thread portion 218 is formed on the upper inner circumferential surface of the valve body 605, and a male thread portion 610 is formed on the upper outer circumferential surface.

[0096] The passage body 606 has an inlet port 202 at the bottom of one side and an outlet port 204 at the top of the opposite side. A fluid passage 611 is formed to connect the inlet port 202 and the outlet port 204. A mounting hole 616 provided in the passage body 606 communicates with the fluid passage 611. A female thread portion 618 is formed on the upper inner circumferential surface of the mounting hole 616. The stator unit 392 is fixed to the valve body 605 via the connecting member 251. The valve body 605 is inserted into and removed from the mounting hole 616 of the passage body 606, thereby attaching and detaching the motor-operated valve 601 to and from the passage body 606. The valve body 605 can be fastened to the passage body 606 by screwing the male thread portion 610 into the female thread portion 618.

[0097] A seal ring 220 is interposed between the upper surface of the valve body 605 and the lower surface of the annular member 307. A seal is ensured between the annular member 307 and the passage body 606 by fastening the screw member 506 to the passage body 606. In this modification as well, a material having a higher machinability index and superior machinability than the annular member 307 is used as the material for the screw member 506 and the valve body 605. Therefore, the same effects as those of the above embodiment can be obtained.

[0098] FIG. 17 is a cross-sectional view showing the configuration of a motor-operated valve according to another modified example. The motor-operated valve 701 of this modification is different from the above modification (FIG. 16) in that a valve body 705 and a passage body 706 are fixed via a pin 550. A mounting hole 716 is provided in the passage body 706. The motor-operated valve 701 is attached to and detached from the passage body 706 by inserting and removing the valve body 705 into and from the mounting hole 716.

[0099] A concave fitting portion 542 is provided on the outer peripheral surface of the upper portion of the valve body 705, into which the pin 550 fits. The passage body 706 is provided with an insertion hole (not shown in FIG. 17) for inserting the pin 550 in the axial direction. The valve body 705 can be fixed to the passage body 706 by fitting the pin 550 into this insertion hole.

[0100] In this modification as well, a material having a higher machinability index and better machinability than the annular member 307 is used as the material for the screw member 506 and the valve body 705. Therefore, the same effects as those of the above embodiment can be obtained.

[0101] 18 is a cross-sectional view showing the configuration of a motor-operated valve according to another modified example, and Fig. 18(A) and (B) are partially enlarged views of the periphery of the seal portion corresponding to part C in Fig. 16. In the above modification (FIG. 16), a configuration was exemplified in which the seal ring 220 was interposed as the "seal portion" between the annular member 307 and the valve body 605. In another modification, a gasket 807 (metal gasket or the like) may be interposed between the annular member 307 and the valve body 605 (FIG. 18(A)).

[0102] Alternatively, a metal seal may be realized by forming an annular protrusion 820 on at least one of the opposing axial surfaces of the annular member 307 and the valve body 605, and appropriately crushing (plastically deforming) the annular protrusion 820 by the fastening force between the screw member 506 and the valve body 605. In the illustrated example, the annular protrusion 820 is formed on the valve body 605 side, but it may also be formed on the annular member 307 side. Alternatively, a metal seal may be realized by forming annular protrusions on both the annular member 307 and the valve body 605.

[0103] Needless to say, such a "seal portion" formed by a gasket or metal seal may be applied to the first and second embodiments and their modified examples.

[0104] FIG. 19 is a partially enlarged cross-sectional view showing the configuration of a motor-operated valve according to another modified example. The motor-operated valve of this modification differs from the above modification (FIG. 14) in the structure of the screw member and the actuating member. The screw member 906 and the valve seat member 308 are assembled coaxially. The screw member 906 is in a stepped cylindrical shape and is configured to be relatively compact in the axial direction. The male screw 338 is located in the lower half of the actuating rod 932 (actuating member), and the female screw 318 is provided at a position below the annular member 307 on the inner circumferential surface of the screw member 906.

[0105] The upper end of the screw member 906 is provided with a flange portion 910 that protrudes radially outward. The flange portion 910 functions as a "locking portion" and faces the annular member 307 in the axial direction. A communication hole 330 is provided so as to penetrate the screw member 906 from top to bottom. The screw member 906 can be fastened to the passage body 203 by screwing the male thread portion 10 into the female thread portion 218.

[0106] In this modification as well, a material having a higher machinability index and better machinability than the annular member 307 is used as the material for the screw member 906. The annular member 307 is located between the flange portion 910 and the male thread portion 10 in the axial direction of the screw member 906.

[0107] Although a preferred embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to that specific embodiment, and various modifications are possible within the scope of the technical concept of the present invention.

[0108] [Other variations] In the above embodiment and modified example, a configuration was exemplified in which the male threaded portion 10 (first male threaded portion) that can be screwed into the female threaded portion 218 (first female threaded portion) provided on the inner peripheral surface of the mounting hole 216, and the male threaded portion 38 (second male threaded portion) that can be screwed into the female threaded portion 108 (second female threaded portion) provided on the inner peripheral surface of the rotor 60 are integrally formed on the outer peripheral surface of the screw member. In the modified example, a configuration in which a second female threaded portion that can be screwed into the second male threaded portion provided on the rotor is formed on the inner peripheral surface of the screw member may be adopted. In that case, the first male threaded portion and the second female threaded portion are integrally formed on the screw member. An annular member is disposed between the first male threaded portion and the second female threaded portion in the axial direction of the screw member. The second male threaded portion corresponds to the "second threaded portion", and the second female threaded portion corresponds to the "third threaded portion".

[0109] In the modified example of the above embodiment, a D-cut structure is shown as an example of an anti-rotation structure between the annular member and the screw member, but the structure is not limited to the cross-sectional shape shown in Figure 6 and may be any structure that has an anti-rotation function.

[0110] Although not mentioned in the above embodiment and modified example, when a screw member is obtained by molding a resin material, problems may occur in the sliding property and wear resistance of the screw part due to continued use of the motor-operated valve. In particular, when a high thrust is required in the screw feed mechanism, thrust loss may occur due to an increase in the sliding resistance of the screw part, and the progress of wear of the screw part may affect the valve opening characteristics such as the valve stroke. In the worst case, the screw part may wear out and the screw feed mechanism may no longer function.

[0111] Therefore, in the modified example, the surface of the screw member molded from a resin material is plated (electroless plating) to ensure the surface hardness of the screw portion. The plating layer applied to the screw member may be a single layer or multiple layers. For example, a first plating layer for ensuring strength may be formed on the surface of the screw member, and a second plating layer having higher sliding properties than the first plating layer may be formed on the surface. The second plating layer may contain a fluororesin such as polytetrafluoroethylene (PTFE). Furthermore, a third plating layer having better adhesion to the resin than the first plating layer may be formed between the first plating layer and the resin surface (surface of the screw member). That is, a third plating layer may be formed on the surface of the screw member, and the first plating layer for ensuring strength may be applied on top of the third plating layer. This modified example solves the problem of ensuring the strength and durability (wear resistance) of the resin screw portion.

[0112] The technical idea of ​​this modification can be expressed, for example, as follows. a body having a fluid passage and containing a valve portion; A valve body that opens and closes the valve portion; a rotor for driving the valve body in a direction in which the valve portion is opened and closed; a screw feed mechanism including a screw member fixed to the body and rotatably supporting the rotor, the screw feed mechanism converting a rotational motion of the rotor into a translational motion; a can that is a cylindrical member that contains the rotor and that defines an internal space in which a fluid pressure acts and an external space in which the fluid pressure does not act; A stator that is inserted into the can; Equipped with The screw member is an electrically operated valve characterized in that a plating layer having a harder layer than the resin of the base material is provided on a threaded portion formed in a resin base material.

[0113] The plating layer may include a lubricating plating layer in its outermost layer, which has higher lubricity (lower friction coefficient) than the resin of the base material. The plating layer may include a first plating layer having a higher hardness than the resin of the base material, and a second plating layer (lubricating plating layer) provided outside the first plating layer and having higher lubricity than the first plating layer. The second plating layer may contain a fluororesin. Furthermore, a third plating layer having better adhesion to resin than the first plating layer may be formed between the first plating layer and the surface of the screw member.

[0114] The body may have a mounting hole communicating with the fluid passage. The screw member may be integrally formed with a first male screw portion that can be screwed into a first female screw portion provided on an inner circumferential surface of the mounting hole, and a third screw portion that can be screwed into a second screw portion provided on the rotor. A plating layer having a harder layer than the resin of the base material may be formed on the first male screw portion and the third screw portion.

[0115] By making the screw member from resin in this way, the manufacturing cost can be reduced. On the other hand, it is necessary to prevent or suppress wear of the threaded portion due to repeated operation of the screw feed mechanism. According to this modification, the plating layer ensures the surface strength of the threaded portion and maintains good slidability of the threaded portion.

[0116] In the first embodiment described above, as shown in Figs. 1 and 2, a configuration has been exemplified in which the rotor unit 90 and the stator unit 92 are separately manufactured as the valve unit 100 and each is fixed to the passage body 200. In a modified example, the rotor unit 90 and the stator unit 92 may be assembled with a connecting member to form an electrically-operated valve. That is, as in the second embodiment shown in Fig. 9, a electrically-operated valve having a cartridge structure may be used. In this case, the valve body 5 constituting the rotor unit 90 corresponds to the "body" of the present invention. The valve body 5 is inserted into and removed from a mounting hole of a mounting object (a piping body, a piping block, etc.), whereby the electrically-operated valve is attached to and detached from the mounting object.

[0117] The technical concept of this modified example and the second embodiment can be expressed as follows. a body having a fluid passage and containing a valve portion; A valve body that opens and closes the valve portion; a rotor for driving the valve body in a direction in which the valve portion is opened and closed; a screw feed mechanism including a screw portion that rotatably supports the rotor and converts a rotational motion of the rotor into a translational motion; a can that is a cylindrical member that contains the rotor and that defines an internal space in which a fluid pressure acts and an external space in which the fluid pressure does not act; an annular member that is assembled to the body and has an open end of the can welded thereto to form the internal space between the annular member and the can; A stator unit that is inserted into the can; Equipped with the annular member is made of the same material as the can; The stator unit is fixed to the body via a connecting member, The body has a guide surface which is more lubricous than the annular member, and the valve element is slidably supported by the guide surface.

[0118] The motor-operated valve may include a first valve body for opening and closing a first valve having a large diameter and a second valve body for opening and closing a second valve having a small diameter, the first valve body being arranged coaxially with the guide surface.

[0119] In this modified example, in the structure of FIG. 2, the inner circumferential surface of the screw member 6 that slidably supports the operating rod 32 (including the valve body 34) functions as the "guide surface". Also, in the structure of FIG. 9, the inner circumferential surface of the guide hole 268 that slidably supports the valve body 270 functions as the "guide surface". With this configuration, the above-mentioned cartridge structure can be realized, and the versatility of the motor-operated valve can be improved for various mounting objects (piping bodies, piping blocks, etc.). Since the body of the motor-operated valve can be made small, the cost can be reduced even if a material with excellent sliding properties is used. By making the body function as a screw member, the number of parts of the motor-operated valve can also be reduced. In other words, the manufacturing cost of the motor-operated valve can be reduced. Also, since the can is welded to the annular member, a material with excellent sliding properties can be used for the body without considering weldability with the can. Therefore, the valve body can be directly guided by the guide surface of the body, and there is no need to provide a guide member for guiding the valve body separately from the body.

[0120] As described in the above embodiment and modified example, by providing a seal between the body and the member to be welded to the can (connecting member such as an annular member), and compressing the seal using the fastening force when fastening the screw member to the body, it is possible to effectively improve the sealing function against external leakage. In particular, it is possible to solve the problem of preventing external leakage when the fluid becomes high pressure with a simple structure.

[0121] Such a technical idea can be expressed, for example, as follows: a body having a fluid passage and containing a valve portion; A valve body that opens and closes the valve portion; a rotor for driving the valve body in a direction in which the valve portion is opened and closed; a can that is a cylindrical member that contains the rotor and that defines an internal space in which a fluid pressure acts and an external space in which the fluid pressure does not act; a connection member to which an open end of the can is welded to form the internal space between the can and the connection member; A screw member fixed to a radially inner side of the connection member; A stator that is inserted into the can; Equipped with The body has a mounting hole communicating with the fluid passage, The connection member is a metal plate or a press-molded product of a metal material, The screw member or the connecting member has a male thread portion that can be screwed into a female thread portion provided in the mounting hole, The connecting member is connected to the body in the axial direction via a seal portion, An electric valve characterized in that when the male threaded portion and the female threaded portion are screwed together to fasten the screw member or the connecting member to the body, the seal portion is compressed in the axial direction to perform a sealing function.

[0122] The "connecting member" referred to here may be the plate-like annular member shown in the above embodiment and modified example, or may be a cylindrical member obtained by press-molding a plate-like material. The connecting member may function as a valve body, or may function as a member constituting the valve body (such as a valve housing). The connecting member may be a press-molded cylindrical member on whose outer circumferential surface the male thread portion is formed.

[0123] FIG. 20 is a cross-sectional view showing the configuration of a motor-operated valve according to another modified example. The motor-operated valve of this modified example has a stepped cylindrical valve housing 950. A valve seat member 8 is coaxially assembled to the lower end of the valve housing 950. The valve housing 950 is obtained by press-forming a plate-shaped metal material, and has a flange portion 907 extending radially outward at its upper end. The valve housing 950 functions as a "connecting member", and the open end of the can 66 is welded to the peripheral portion of the flange portion 907.

[0124] A screw member 926 is coaxially assembled to the upper part of the valve housing 950. The screw member 926 has a structure similar to that of the screw member 406 in FIG. 14, but does not have the male thread portion 10. The lower part of the screw member 926 is press-fitted into the upper part of the valve housing 950. The male thread portion 10 is provided on the outer peripheral surface of the upper part of the valve housing 950.

[0125] The valve housing 950 has a smaller diameter below the male thread portion 10, and the small-diameter cylindrical portion 954 extends toward the fluid passage. An inlet port 26 (communication hole) is provided on the side surface of the cylindrical portion 954. The valve housing 950 can be fastened to the passage body 203 by screwing the male thread portion 10 into the female thread portion 218. At this time, the seal ring 220 is compressed in the axial direction by the flange portion 907 to exert a sealing function.

[0126] In the above embodiment, a structure in which the rotor and the screw member are directly screwed together is exemplified. In a modified example, a speed reducing mechanism may be provided between the rotor and the screw member to adjust the degree to which the rotational motion of the rotor is converted into translational motion. In other words, the amount of axial displacement of the valve body relative to the number of rotations of the rotor may be adjusted. The speed reducing mechanism may be a planetary gear mechanism.

[0127] In the above embodiment, the rotational motion of the rotor is converted into the translational motion (axial motion) of the actuating member by the operation of the screw feed mechanism. At this time, the rotor also translates together with the actuating member. In a modified example, the rotor may be configured to maintain its axial position while the actuating member translates (see, for example, U.S. Patent Application Publication No. 2018 / 0135903). Alternatively, a structure in which the rotation of the rotor is transmitted to the actuating member via a gear may be adopted (see, for example, JP 2024-008534 A).

[0128] In the above embodiment, the motor-operated valve 1 is configured such that the valve element 34 is attached to and detached from the valve seat 24 to open and close the valve portion. In a modified example, the motor-operated valve 1 may be a spool valve in which the valve element is inserted and removed from the valve hole to open and close the valve portion. The valve element may be one that moves toward and away from the valve hole to open and close the valve portion, and adjust the opening degree of the valve portion. Here, "moving toward and away from" means moving close to or away from the valve seat, and includes both the case of being attached to and detached from the valve seat and the case of being inserted and removed from the valve hole. In the case of a spool valve, a predetermined clearance may be formed to allow leakage of fluid even in the closed valve state.

[0129] In the above embodiment, the stator includes a yoke having pole teeth. In a modified example, the stator may include a laminated core.

[0130] In the above embodiment, the stator unit 92 is a two-phase stepping motor, but it may be configured as a three-phase stepping motor.

[0131] In the above embodiment, the motor-operated valve is configured as an expansion valve, but it may be configured as an opening / closing valve without an expansion function.

[0132] The motor-operated valve of the above embodiment is preferably applied to a refrigeration cycle using HFO-1234yf or the like as a refrigerant, but can also be applied to a refrigeration cycle using a refrigerant with a high operating pressure such as carbon dioxide. In that case, an external heat exchanger such as a gas cooler is disposed in the refrigeration cycle instead of the condenser.

[0133] In the above embodiment, the motor-operated valve is applied to the refrigeration cycle of an automotive air conditioner, but the motor-operated valve can be applied to any air conditioner equipped with an electric expansion valve, not limited to vehicles. The motor-operated valve may also be configured to control the flow of fluids other than refrigerant, such as hot water in a hot water heater or hydraulic fluid (hydraulic oil) in a hydraulic control device.

[0134] The present invention is not limited to the above-mentioned embodiment and modified examples, and the components can be modified without departing from the gist of the present invention. Various inventions can be formed by appropriately combining multiple components disclosed in the above-mentioned embodiment and modified examples. In addition, some components can be deleted from all the components shown in the above-mentioned embodiment and modified examples. [Explanation of symbols]

[0135] 1 motor-operated valve, 5 valve body, 6 screw member, 7 annular member, 8 valve seat member, 9 flange portion, 10 male screw portion, 12 step, 22 valve hole, 24 valve seat, 26 inlet port, 28 outlet port, 30 valve chamber, 32 operating rod, 34 valve body, 38 male screw, 60 rotor, 62 rotating shaft, 64 stator, 66 can, 76 case, 90 rotor unit, 92 stator unit, 100 valve unit, 101 connecting member, 107 annular member, 108 female screw, 109 screw feed mechanism, 118 circuit board, 119 magnetic sensor, 124 connector portion, 126 screw member, 128 valve seat member, 130 flat surface, 132 insertion hole, 190 rotor unit, 200 passage body, 201 motor-operated valve, 202 Inlet port, 204 Outlet port, 206 Inlet port, 207 Annular member, 208 Outlet port, 216 Mounting hole, 218 Female thread portion, 220 Seal ring, 226 Screw member, 227 Screw member, 250 First valve, 251 Connection member, 252 Second valve, 260 Valve body, 264 Valve hole, 266 Valve seat, 270 Valve element, 274 Back pressure chamber, 276 Valve chamber, 278 Operation connecting member, 284 Locking portion, 288 Communication hole, 290 Rotor unit, 300 Valve unit, 301 Motor-operated valve, 302 Rotor core, 304 Rotor magnet, 305 Valve body, 306 Screw member, 307 Annular member, 308 Valve seat member, 309 Screw feed mechanism, 310 First member, 312 Second member, 318 Female thread, 320 Male thread, 322 Female thread, 324 Locking portion, 330 Communication hole, 332 Operating rod, 338 Male thread, 360 Rotor, 390 Rotor unit, 392 Stator unit, 405 Valve body, 406 Screw member, 501 Motor-operated valve, 505 Valve body, 506 Screw member, 510 Valve housing, 516 Mounting hole, 520 Seal ring, 550 Pin, 601 Motor-operated valve, 605 Valve body, 606 Passage body, 610 Male thread portion, 611 Fluid passage, 616 Mounting hole, 618 Female thread portion, 701 Motor-operated valve, 705 Valve body, 716 Mounting hole, 807 Gasket, 820 Annular projection, 905 Valve body, 906 Screw member, 907 Flange portion, 910 Flange portion, 926; screw member, 932; operating rod, 950Valve housing, S gap, W full circumference weld.

Claims

1. a body having a fluid passage and containing a valve portion; A valve body that opens and closes the valve portion; a rotor for driving the valve body in a direction in which the valve portion is opened and closed; a can that is a cylindrical member that contains the rotor and that defines an internal space in which a fluid pressure acts and an external space in which the fluid pressure does not act; a screw member located radially inside the can and assembled to the body; an annular member that is assembled to an outer peripheral surface of the screw member and has an open end of the can welded thereto to form the internal space between the annular member and the can; A stator that is inserted into the can; Equipped with The body has a mounting hole communicating with the fluid passage, the screw member has a male thread portion that can be screwed into a female thread portion provided in the mounting hole, the annular member is made of the same material as the can and different material from the screw member, The motor-operated valve, characterized in that the annular member is fixed to the body by fastening the screw member to the body.

2. the annular member and the body are connected in the axial direction via a seal portion, 2. The motor-operated valve according to claim 1, wherein the seal portion is compressed in the axial direction by fastening the screw member to the body, thereby exerting a sealing function.

3. the screw member has a locking portion that faces the annular member in the axial direction, 3. The motor-operated valve according to claim 1, wherein the annular member is located between the locking portion and the male thread portion in the axial direction of the screw member.

4. As the locking portion, a flange portion or a step portion is provided on an outer periphery of the screw member, 4. The motor-operated valve according to claim 3, wherein the annular member is clamped between the locking portion and the body in response to the male threaded portion being screwed into the female threaded portion.

5. 3. The motor-operated valve according to claim 1, further comprising a rotation prevention structure between the annular member and the screw member for restricting rotation of the annular member relative to the screw member.

6. the screw member is made of a resin material, while the annular member is made of a metal material, 3. The motor-operated valve according to claim 1, wherein the annular member is integrated with the screw member by insert molding of a resin material.

7. the threaded member is made of a metal material having a higher machinability index than the annular member, 3. The motor-operated valve according to claim 1, wherein the annular member is press-fitted onto an outer circumferential surface of the screw member.

8. 3. The motor-operated valve according to claim 1, wherein the annular member is obtained by press-molding a metal plate.

9. a valve seat member having a valve seat formed therein; The screw member and the valve seat member are coaxially connected, 3. The motor-operated valve according to claim 1, wherein the valve body is attached to and detached from the valve seat to open and close the valve portion.

10. an actuating member provided coaxially with the rotor; a screw feed mechanism for converting the rotational motion of the rotor into the translational motion of the actuating member; Equipped with 10. The motor-operated valve according to claim 9, wherein the screw member constitutes a part of the screw feed mechanism.

11. the actuating member is an actuating rod having the valve body integrally provided at a tip thereof and having a male thread provided on an outer circumferential surface thereof, The screw member has an inner peripheral surface provided with a female thread, 11. The motor-operated valve according to claim 10, wherein the female thread of the screw member and the male thread of the actuation rod constitute the screw feed mechanism.

12. the screw member has a cylindrical portion extending toward the fluid passage, a communication hole that forms a part of the fluid passage is provided on a side surface of the cylindrical portion, 10. The motor-operated valve according to claim 9, wherein the valve seat member is attached to an open end of the cylindrical portion.

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