Motor-operated valve

Abstract

To provide an electric valve which can easily and inexpensively assemble a valve body and a stator unit.SOLUTION: An electric valve 1 includes: a valve body 5 having a valve hole 22 for making an inlet port 26 and an outlet port 28 communicate with each other; a valve body 34 for opening and closing a valve part while coming into contact and separating with / from the valve hole 22; a rotor 60 for driving the valve body 34 in an opening / closing direction of the valve part; a can 66 being cylindrical member coaxially fixed to the valve body 5, encapsulating the rotor 60, and defining an internal space in which the pressure of liquid acts and an external space in which the pressure of the light does not act: a stator unit 78 including a stator 64 which is coaxially and externally fit to the can 66; and a bracket 130 for fixing the stator unit 78 and the valve body 5 to each other. The bracket 130 includes a fitting part which is fixed to the valve body 5 in an axial line direction and an orthogonal direction with respect to the valve body, and a connection part connected to the stator unit 78 in the axial line direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a motor-operated valve, and more particularly to an assembly structure between a valve body and a stator unit. [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] When assembling a motor-operated valve to a heat exchanger such as an evaporator, the valve body of the motor-operated valve is assembled and fixed to a piping body provided on the heat exchanger side (see Patent Document 1). The motor-operated valve is configured by assembling a valve body and a stator unit in the axial direction.

[0004] Patent Document 1 discloses a structure (first embodiment) in which a fixing portion is provided integrally with a valve body and a stator unit is assembled to the fixing portion, and a structure (second embodiment) in which the valve body and the stator are assembled in the axial direction with a flange member having an integrally formed fixing portion sandwiched therebetween, and the stator unit is assembled to the fixing portion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-158150 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the first embodiment of Patent Document 1, the shape of the valve body becomes complicated due to the integral fixing portion, so that the number of steps increases when the valve body is obtained by cutting, and the processing cost increases. On the other hand, in the second embodiment, the valve body and the flange member are assembled by press-fitting the valve body into the fitting hole of the flange member, so that high assembly accuracy is required and the process is difficult.

[0007] An object of the present invention is to provide an electrically operated valve in which the valve body and the stator unit can be assembled easily and at low cost. [Means for solving the problem]

[0008] An embodiment of the motor-operated valve of the present invention comprises a valve body having an inlet port for introducing a fluid, an outlet port for discharging the fluid, and a valve hole connecting the inlet port and the outlet port, a valve element that opens and closes a valve section by moving toward and away from the valve hole, a rotor for driving the valve element in the direction of opening and closing the valve section, a can that is fixed coaxially to the valve body and is a cylindrical member containing the rotor and that defines an internal space where the pressure of the fluid acts and an external space where the pressure of the fluid does not act, a stator unit including a stator that is coaxially inserted outside the can, and a bracket that fixes the stator unit to the valve body. The bracket includes a fitting portion that fits into the valve body in a direction perpendicular to the axial direction, and a connecting portion that is connected to the stator unit in the axial direction.

[0009] According to this embodiment, the bracket is fitted to the valve body in a direction perpendicular to the axial direction (transverse direction), and then the stator unit is connected to the bracket in the axial direction while being assembled to the valve body, thereby fixing the valve body and the stator unit. Since the direction in which the stator unit is connected to the bracket is perpendicular to the fitting direction of the bracket to the valve body, the bracket will not come loose when the stator unit is assembled to the valve body. Meanwhile, since the bracket is directly connected to the stator unit in the axial direction, there is little need to make the bracket large in the radial direction of the valve body. Therefore, the assembly of the valve body and the stator unit can be achieved easily and at low cost. Effect of the Invention

[0010] According to the present invention, it is possible to provide a motor-operated valve in which the valve body and the stator unit can be assembled easily and at low cost. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view of an electric valve device according to an embodiment, as viewed obliquely from below; [Diagram 2] 2 is a cross-sectional view showing the internal structure of the motor-operated valve device. FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 4 is a diagram illustrating a configuration of a bracket. [Diagram 5] 5 is a diagram showing an assembly structure of a bracket to a valve body. FIG. [Figure 6] FIG. 13 is a diagram showing stresses that occur when assembling a bracket. [Figure 7] 4A to 4C are diagrams illustrating an assembly method of the motor-operated valve and the motor-operated valve device. [Figure 8] 13A and 13B are diagrams illustrating a configuration of a bracket according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 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.

[0013] FIG. 1 is a perspective view of a motor-operated valve device according to an embodiment, as viewed obliquely from below. The motor-operated valve device 200 is configured by assembling the motor-operated valve 1 to a piping body 210. The motor-operated valve device 200 is applied to a refrigeration cycle of an air conditioner for an automobile (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 to send 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.

[0014] The piping body 210 is provided integrally with the evaporator (heat exchanger) and has an inlet port 212 to which a pipe extending from the condenser side is connected, and an outlet port 214 to which a pipe leading to an inlet of the evaporator is connected. The motor-operated valve 1 is assembled to the piping body 210 and functions as an expansion valve of the refrigeration cycle. The motor-operated valve 1 is a device that can be distributed in the market independently of the piping body 210, and is configured to be detachable from the piping body 210.

[0015] FIG. 2 is a cross-sectional view showing the internal structure of the motor-operated valve device 200. As shown in FIG. The piping body 210 has a passage 216 that connects the inlet port 212 and the outlet port 214. An attachment hole 218 opens upward at the top of the piping body 210. The attachment hole 218 is a stepped circular hole having a shape complementary to the valve body 5 of the motor-operated valve 1, and communicates with the passage 216.

[0016] FIG. 3 is a cross-sectional view taken along line AA in FIG. When assembling the motor-operated valve 1 to the piping body 210, the valve body 5 to which the seal rings 14 and 20 are attached is inserted into the attachment hole 218. Then, the motor-operated valve 1 is fixed to the piping body 210 via a pair of pins 220 (described in detail later). The seal ring 14 prevents refrigerant from leaking to the outside, and the seal ring 20 seals between the upstream and downstream passages of the valve portion.

[0017] The motor-operated valve 1 is formed by assembling a valve body 2 and a motor unit 3. The valve body 2 has a valve body 5 that houses a valve portion. The valve body 5 is formed by assembling a first body 6 and a second body 8 coaxially. Both the first body 6 and the second body 8 are made of stainless steel (hereinafter referred to as "SUS"). Since the second body 8 is provided with a valve seat 24, a material with excellent wear resistance is selected. The first body 6 has better weldability than the second body 8, and the second body 8 has better workability than the first body 6.

[0018] The first body 6 is a stepped cylinder whose outer diameter tapers stepwise downward. The outer diameter of the upper end of the first body 6 is slightly tapered to form a step-like locking portion 52. The outer peripheral surfaces of the lower and upper portions of the first body 6 are formed with seal receiving portions 12, 80 each consisting of annular grooves, into which seal rings 14, 82 (O-rings) are fitted.

[0019] The lower part of the first body 6 is provided with a circular hole-shaped recessed fitting portion 16. The second body 8 is cylindrical with a bottom, and its upper part is press-fitted into the recessed fitting portion 16. A seal accommodating portion 18 consisting of an annular groove is formed on the outer circumferential surface of the lower part of the second body 8, and a seal ring 20 is fitted into it. A valve hole 22 is provided so as to pass through the bottom part of the second body 8 in the axial direction, and a valve seat 24 is formed at the upper opening of the valve hole 22.

[0020] An inlet port 26 is provided on the side of the second body 8, and an outlet port 28 is provided on the bottom. The inlet port 26 communicates with an introduction port 212, and the outlet port 28 communicates with a discharge port 214 (see FIG. 2). A valve chamber 30 is formed inside the first body 6 and the second body 8. The inlet port 26 and the outlet port 28 communicate with each other via the valve chamber 30.

[0021] A ring-shaped fitting recess 17 is provided on the outer circumferential surface of the first body 6 slightly above the seal accommodating portion 12. Meanwhile, a pair of linear fitting recesses 19 are provided at positions facing the fitting recess 17 on the inner circumferential surface of the mounting hole 218. The pair of fitting recesses 19 are provided at positions symmetrical with respect to the axis of the piping body 210. As shown in the figure, the motor-operated valve 1 and the piping body 210 are fixed together by fitting pins 220 into a pair of fitting holes 21 formed between these fitting recesses 17, 19, respectively.

[0022] An insertion hole 222 is provided on an extension line of the fitting hole 21 in the piping body 210 (see FIG. 1), and the pin 220 is inserted into the fitting hole 21 through the insertion hole 222. The cross section of the fitting hole 21 and the cross section of the pin 220 are generally complementary in shape so that the valve body 5 and the piping body 210 can be assembled stably. In this embodiment, a male thread is provided on the head of the pin 220, and a female thread is provided on the inner peripheral surface of the insertion hole 222, and the pin 220 is fastened to the piping body 210. In a modified example, the pin 220 may be fixed to the piping body 210 by press-fitting the pin 220 into the insertion hole 222 without providing such a screw structure. Also, the pin 220 may be fixed to the piping body 210 by inserting it into the insertion hole 222 and then tightening it.

[0023] An actuating rod 32 extending from the rotor 60 of the motor unit 3 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.

[0024] A guide member 36 is erected at the center of the upper part of the first body 6. The guide member 36 is obtained by cutting a tube material made of a non-magnetic metal into a stepped cylindrical shape, and a male thread 38 is formed on the outer circumferential surface of the axial center part. The lower end of the guide member 36 has a large diameter, and the large diameter part 40 is press-fitted into the upper center of the first body 6 and fixed coaxially. In a modified example, the first body 6 and the guide member 36 may be fixed by crimping. The guide member 36 supports the operating rod 32 axially slidably with its inner circumferential surface, and supports the rotating shaft 62 of the rotor 60 rotatably and slidably with its outer circumferential surface. The rotating shaft 62 is made of a non-magnetic metal.

[0025] On the other hand, the motor unit 3 is configured as a two-phase stepping motor including a rotor 60 and a stator 64. The motor unit 3 has a cylindrical can 66 with a bottom, with the rotor 60 disposed inside the can 66 and the stator 64 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 the pressure of the refrigerant does not act.

[0026] The can 66 is made of a non-magnetic metal (SUS in this embodiment), and is assembled coaxially with its lower portion being fitted onto the upper end of the first body 6. The amount of insertion of the can 66 is regulated by having its lower end engaged with the engaging portion 52. The valve body 5 and the can 66 are fixed and sealed by applying a full circumferential weld (not shown) along the boundary between the lower end of the can 66 and the first body 6. The space surrounded by the valve body 5 and the can 66 forms the above-mentioned pressure space.

[0027] 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 provided integrally with a case 76 of the motor unit 3. That is, the case 76 is obtained by injection molding (also called "insert molding" or "mold molding") of a corrosion-resistant resin material. The stator 64 is covered with the molded resin obtained by the injection molding. The case 76 is made of the molded resin. Hereinafter, the integrated part of the stator 64 and the case 76 (a molded product in this embodiment) will also be referred to as a "stator unit 78."

[0028] The stator unit 78 has a hollow structure, and is assembled to the valve body 5 while the can 66 is coaxially inserted therethrough. A seal receiving portion 80 is formed on the outer peripheral surface of the first body 6 slightly below the locking portion 52, and a seal ring 82 is fitted into it. The seal ring 82 is interposed between the upper outer peripheral surface of the first body 6 and the lower inner peripheral surface of the case 76, thereby preventing the outside atmosphere (water, etc.) from entering the gap between the can 66 and the stator 64.

[0029] The rotor 60 includes a cylindrical rotor core 102 attached to the rotating shaft 62, a rotor magnet 104 provided on the outer peripheral surface of the rotor core 102, and a sensor magnet 106 provided on the upper end surface of the rotor core 102. The rotor core 102 is attached to the rotating shaft 62. The sensor magnet 106 is attached coaxially to the upper end of 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.

[0030] The rotating shaft 62 is a cylindrical shaft with a bottom, and is fitted onto the guide member 36 with its open end facing downward. A female thread 108 is formed on the inner peripheral surface of the lower part of the rotating shaft 62, and meshes with the male thread 38 of the guide member 36. A screw feed mechanism 109 formed by these threads converts the rotational motion of the rotor 60 into axial motion of the operating rod 32. This causes the valve element 34 to move (rise and fall) in the axial direction, that is, in the opening and closing direction of the valve portion.

[0031] 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.

[0032] The motor unit 3 has a circuit board 118 on the outside of the can 66. The circuit board 118 is fixed inside the case 76. In this embodiment, 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 lid 77. The circuit board 118 is disposed in the space below the lid 77 of the case 76.

[0033] 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.

[0034] 2, terminals 120 connected to coil 68 extend from bobbin 70 and are connected to circuit board 118. A power supply terminal, a ground terminal, and a communication terminal (collectively referred to as "connection terminals 122") extend from circuit board 118 and are each drawn out to the outside through a side wall of case 76. A connector portion 124 is integrally provided on the side of case 76, and connection terminals 122 are disposed inside connector portion 124.

[0035] In this embodiment, the valve body 5 and the stator unit 78 are fixed together via a bracket 130. A concave fitting portion 90 consisting of an annular groove is formed in the outer circumferential surface of the valve body 5 at a position between the seal accommodating portion 80 and the fitting recess 17. The bracket 130 is attached to the valve body 5 so as to fit into the concave fitting portion 90, and is also fixed to the stator unit 78. The structure of the bracket 130 enables the valve body 5 and the stator unit 78 to be assembled together easily and at low cost. Details of this will be described below.

[0036] Figure 4 is a diagram showing the configuration of the bracket 130. (A) is a plan view, (B) is a front view, (C) is a rear view, and (D) is a right side view. For convenience of explanation, Figure 4(A) shows the positional relationship with the valve body 5 (see the two-dot chain line). 4(A), the bracket 130 is a press-formed part made of a metal plate such as stainless steel, and has a structure that is symmetrical about a center line L1 in a plan view. The bracket 130 has a fitting portion 132 that fits into the side surface of the valve body 5, and a pair of left and right connection portions 134 that are connected to the underside of the stator unit 78. The bracket 130 is obtained by punching and bending a single metal plate by press working, and therefore has a uniform thickness throughout.

[0037] The fitting portion 132 has a bifurcated structure that opens toward the side of the valve body 5. Hereinafter, the open side of the bifurcated structure of the fitting portion 132 will also be referred to as the "tip side" and the opposite side as the "base side." The inside of the fitting portion 132, that is, the side that houses the valve body 5, will also be referred to as the "inner side."

[0038] The fitting portion 132 has a pair of left and right extending portions 136 extending toward the tip side, and a connecting portion 138 connecting these extending portions 136 at the base end side. The fitting portion 132 has a semi-annular shape having a predetermined circumscribing circle. The left extending portion 136 (first extending portion 136a) and the right extending portion 136 (second extending portion 136b) have shapes symmetrical with respect to the center line L1, and face each other with the valve body 5 sandwiched therebetween in the radial direction (inner side).

[0039] The extending portions 136 have contact portions 140 that come into point contact with the outer circumferential surface of the valve body 5 when the fitting portion 132 is assembled to the valve body 5. The pair of left and right contact portions 140 are located in the radial direction of the valve body 5, and the distance w1 between them is approximately equal to the diameter. The pair of left and right extending portions 136 have a two-step tapered shape that slightly widens the distance between them from the contact portions 140 toward the tip end.

[0040] At the boundary between the first tapered portion 142 and the second tapered portion 144 that form the two-stage tapered shape, a locking portion 146 that protrudes slightly inward is provided. The distance w2 between the pair of left and right locking portions 146 is slightly smaller than the distance w1 (i.e., slightly smaller than the diameter of the valve body 5). The pair of locking portions 146 function as elastic engagement portions 148 that locally narrow the distance between the first extension portion 136a and the second extension portion 136b. By providing this elastic engagement portion 148, once the bracket 130 is assembled to the valve body 5 as shown in the figure, it is configured to be difficult to come off (described in detail later).

[0041] As shown in FIG. 4B, the extending portions 136 have low-rigidity portions 150 each having a smaller cross section than the tip end side by cutting out the inner surface on the base end side of the abutting portion 140. Also, as shown in FIG. 4C, the connecting portion 138 has a cutout portion 152 on the side surface on the base end side (the side surface opposite the extending portions 136). With this configuration, when the bracket 130 is assembled to the valve body 5, the pair of extending portions 136 elastically deform toward the outside of the fitting portion 132 (flex appropriately radially outward), making the assembly work easier. The cutout portion 152 serves to release the load generated when the extending portions 136 elastically deform.

[0042] The connecting portion 138 has a fitting protrusion 154 that protrudes from the center of the tip side surface. Meanwhile, in the valve body 5, a flat locking surface 92 is formed by a so-called D-cut on the bottom surface of a predetermined position of the concave fitting portion 90, and a fitting recess 94 is provided on the locking surface 92. By fitting the fitting protrusion 154 into the fitting recess 94, the mounting angle (circumferential position) of the bracket 130 can be positioned around the axis L2 of the valve body 5.

[0043] 4(D), the pair of connecting portions 134 are connected to the pair of extending portions 136 via connecting portions 156, respectively. The connecting portions 134 extend parallel to the extending portions 136. The connecting portions 156 extend parallel to the axis L2 of the valve body 5, with their upper ends connected to the connecting portions 134 and their lower ends connected to the extending portions 136.

[0044] The left connecting portion 134 (first connecting portion 134a) is connected to the low rigidity portion 150 of the first extending portion 136a via a first connecting portion 156a. The right connecting portion 134 (second connecting portion 134b) is connected to the low rigidity portion 150 of the second extending portion 136b via a second connecting portion 156b.

[0045] The connecting portion 134 has an arc shape having a predetermined width in the radial direction centered on the axis L2 in a plan view, and has a pair of insertion holes 158 on both sides of the connection point with the coupling portion 156. The connecting portion 134 has an inscribing circle and a circumscribing circle centered on the axis L2. The inscribing circle of the connecting portion 134 is slightly larger than the circumscribing circle of the fitting portion 132. A pair of cutouts 160 is provided between the pair of insertion holes 158 on both sides of the connection point. The provision of these cutouts 160 facilitates bending at the connection point between the connecting portion 134 and the coupling portion 156.

[0046] 5A and 5B are diagrams showing an assembly structure of the bracket 130 to the valve body 5. (A) is a cross-sectional view taken along the line BB in FIG. 3. (B) is an enlarged view of part C in (A), and (C) is an enlarged view of part D in (A). 5(A) and (B), the fitting portion 132 has a flat abutment surface 153 on the tip side of the connecting portion 138. A fitting protrusion 154 is provided in the center of the abutment surface 153. Meanwhile, the recessed fitting portion 90 of the valve body 5 is formed with a partially flat locking surface 92, and a fitting recess 94 is provided on the surface facing the fitting protrusion 154.

[0047] When assembling the bracket 130 to the valve body 5, the fitting portion 132 is pushed from the tip side (open side) in the transverse direction of the valve body 5 (direction perpendicular to the axial direction). At this time, the extension portion 136 is guided by the concave fitting portion 90. When the elastic engagement portion 148 gets over the transverse surface of the valve body 5, it is pushed outward and temporarily elastically deformed, but by getting over the transverse surface, it elastically returns to its original shape, and the fitting portion 132 is fitted into the valve body 5. In other words, the fitting portion 132 functions as a so-called "snap fit."

[0048] At this time, the fitting protrusion 154 fits into the fitting recess 94, but the abutment surface 153 abuts against and engages with the locking surface 92, restricting movement of the fitting protrusion 154 in the assembly direction. The fitting protrusion 154 and the fitting recess 94 have complementary shapes, but when the abutment surface 153 abuts against the locking surface 92, a predetermined clearance CL is formed between the tip surface of the fitting protrusion 154 and the bottom surface of the fitting recess 94.

[0049] As shown in Figs. 5(A) and (C), when the bracket 130 is assembled to the valve body 5, a sufficient clearance is formed between the bottom surface of the concave fitting portion 90 and the apex of the locking portion 146, so that unnecessary stress is not continuously applied to the extension portion 136. The abutting portion 140 abuts against the valve body 5, but the reaction force from the bottom surface of the concave fitting portion 90 does not act or is negligibly small. If an attempt is made to remove the bracket 130 from the valve body 5 in this fitted state, the elastic engagement portion 148 acts as a resistance to regulate this. Therefore, the bracket 130 is prevented from falling off unless there is an action such as intentionally pulling it out from the outside. In a modified example, the portion of the bracket 130 corresponding to the abutting portion 140 (also called the "adjacent portion") may be configured not to abut against the valve body 5.

[0050] 6A to 6D are diagrams showing the stresses that occur when assembling the bracket 130. (A) to (D) show the results of stress analysis during the assembling process. As can be seen from this analysis result, in the process of assembling the bracket 130, the bracket 130 is elastically deformed and subjected to stress when the elastic engagement portion 148 overcomes the transverse surface of the valve body 5, but the stress does not act on the bracket 130 or at least is alleviated after the elastic engagement portion 148 overcomes the transverse surface. This makes it possible to prevent deformation of the bracket 130 after it is assembled to the valve body 5. This also ensures the positioning accuracy of the bracket 130 and the stator unit 78.

[0051] 7A to 7C are diagrams illustrating a method of assembling the motor-operated valve 1 and the motor-operated valve device 200. (A) to (C) show the assembling process. 7(A), the bracket 130 is attached laterally (perpendicular to the axial direction of the valve body 5) to the valve assembly 250, which is made by assembling the rotor 60 and the can 66 to the valve body 5 incorporating the valve portion. At this time, the elastic engagement portion 148 overcomes the transverse surface of the valve body 5 as described above, so that the bracket 130 is stably held in a state where it is fitted into the recessed fitting portion 90.

[0052] Next, the stator unit 78 is coaxially fitted onto the can 66 and assembled to the valve assembly 250. At this time, the tip openings 81 of the stator unit 78 are guided and inserted into the gaps between the outer circumferential surface of the valve body 5 and each of the pair of connecting portions 156 (see FIG. 3).

[0053] A plurality of circular boss-shaped engagement portions 79 are protruded from the bottom of the stator unit 78 so as to surround the tip opening 81. Four of these engagement portions 79 are inserted into the four insertion holes 158 of the bracket 130, respectively, to connect the connection portion 134 to the stator unit 78 in the axial direction.

[0054] As described above, the snap-fit ​​function prevents deformation of the bracket 130 after assembly to the valve body 5, so even if the clearance between the insertion holes 158 and the engagement portions 79 is set small, the engagement portions 79 can be easily inserted into the insertion holes 158. As a result, the positioning accuracy of the bracket 130 and the stator unit 78 can be ensured.

[0055] Then, the engaging portion 79 protruding from the insertion hole 158 is melted and crimped with a laser. That is, the connecting portion 134 is welded (thermally crimped) to the stator unit 78, whereby the assembly of the motor-operated valve 1 is completed.

[0056] Next, as shown in Fig. 7(B), the motor-operated valve 1 is assembled to the piping body 210. As already described, the valve body 5 is inserted into the mounting hole 218 (see Fig. 2). Then, as shown in Fig. 7(C), the pair of pins 220 are inserted into the pair of insertion holes 222 and fitted into the fitting holes 21, thereby fixing the motor-operated valve 1 and the piping body 210.

[0057] Returning to FIG. 3, the motor-operated valve 1 configured as above functions as an electric expansion valve whose valve opening can be adjusted by controlling the drive of the motor unit 3. 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, 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.

[0058] The rotor 60 moves in the vertical direction by a screw feed mechanism 109 between it and the guide member 36. In other words, 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. This 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 is attached to a piping body and functions as an expansion valve, the valve section is controlled to a small opening.

[0059] The control unit detects the rotation angle of the sensor magnet 106 (the rotation angle of the rotor 60) based on the detection signal of the magnetic sensor 119, and can calculate the valve opening degree.

[0060] As described above, in this embodiment, the bracket 130 is fitted transversely to the valve body 5, and then the stator unit 78 is assembled to the valve body 5 while being axially connected to the bracket 130, thereby fixing the valve body 5 and the stator unit 78.

[0061] Since the direction in which the stator unit 78 is connected to the bracket 130 is perpendicular to the fitting direction of the bracket 130 to the valve body 5, the fitting of the bracket 130 will not come loose when the stator unit 78 is assembled to the valve body 5. Therefore, there is no need to fix the bracket 130 to the valve body 5 by a fixing means such as welding. Meanwhile, since the bracket 130 is directly connected to the stator unit 78 in the axial direction, there is little need to make the bracket 130 large in the radial direction of the valve body 5. Therefore, assembly of the valve body 5 and the stator unit 78 can be achieved easily and at low cost.

[0062] In addition, in this embodiment, the fitting portion 132 of the bracket 130 functions as a snap fit, which facilitates the fitting operation into the valve body 5, and the bracket 130 does not easily fall off after fitting. This allows the subsequent process of connecting the connection portion 134 and the stator unit 78 to be performed smoothly, improving manufacturing efficiency. The bracket 130 is stably held in the valve body 5 by the snap fit function, so a large holding load is not required as in the case of using press fitting or the like. This allows the bracket 130 to be made of a thin plate. Another advantage is that the elasticity of the fitting portion 132 can be easily ensured by making it of a thin plate.

[0063] Furthermore, since the tip opening 81 of the stator unit 78 is guided in the gap between the connecting portion 156 of the bracket 130 and the outer peripheral surface of the valve body 5, rattling during assembly of the stator unit 78 is reduced, improving workability.

[0064] 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.

[0065] 8A to 8D are diagrams showing the configuration of a bracket according to a modified example, in which (A) is a plan view, (B) is a front view, (C) is a rear view, and (D) is a right side view. 8(A), the bracket 170 of this modification is provided with a fitting structure for positioning the motor-operated valve 1 and the piping body 210. That is, the connecting portion 138 of the fitting portion 172 is provided with a fitting protrusion 174 extending on the opposite side to the fitting protrusion 154.

[0066] As shown in Figures 8(B) to (D), the fitting protrusion 174 has its tip bent downward and fits into a fitting hole 230 (see Figure 8(A)) formed in the upper surface of the piping body 210. That is, after the motor-operated valve 1 is assembled as shown in Figure 7(B), the fitting protrusion 174 is fitted into the fitting hole 230, thereby enabling the mounting angle between the motor-operated valve 1 and the piping body 210 to be positioned about the axis L2. According to this modification, the bracket 170 can determine the position between the stator unit 78 and the valve body 5 as well as the position between the motor-operated valve 1 and the piping body 210.

[0067] In the above embodiment, the fitting portion 132 is semi-annular in plan view. In a modified example, the fitting portion may be rectangular in plan view. The fitting portion may be appropriately selected as long as it has an open side on one side so that it can fit into the side surface of the valve body (concave fitting portion) and has an elastic engagement portion that prevents it from falling off the valve body.

[0068] In the above embodiment, as shown in Fig. 4, the connecting portion 134 and the extending portion 136 are spaced apart in the axial direction and are connected to each other by the connecting portion 156. In this regard, depending on the shape (lower structure) of the stator unit, a configuration in which the connecting portion and the extending portion are located on the same plane is also possible. In that case, the connecting portion extending in the axial direction may be omitted.

[0069] In the above embodiment, the connection between the connecting portion 134 of the bracket 130 and the stator unit 78 is realized by welding. In a modified example, the connecting portion 134 and the stator unit 78 may be fixed to each other by screw joint, press fitting, or other fixing means.

[0070] 4 and 5, the above embodiment shows an example in which the concave fitting portion 90 is formed by an annular groove provided around the periphery of the valve body 5. In a modified example, the concave fitting portion may be formed by a pair of grooves formed in parallel on the side surface of the valve body.

[0071] In the above embodiment, the stator includes a yoke having pole teeth. In a modified example, the stator may include a laminated core.

[0072] In the above embodiment, the motor unit 3 is a two-phase stepping motor, but it may be configured as a three-phase stepping motor.

[0073] 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.

[0074] The motor-operated valve of the above embodiment is preferably applied to a refrigeration cycle that uses a refrigerant such as an alternative fluorocarbon (HFC-134a) as a refrigerant, but can also be applied to a refrigeration cycle that uses 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.

[0075] 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.

[0076] 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]

[0077] 1 motor-operated valve, 2 valve body, 3 motor unit, 5 valve body, 17 fitting recess, 19 fitting recess, 21 fitting hole, 22 valve hole, 24 valve seat, 26 inlet port, 28 outlet port, 30 valve chamber, 32 operating rod, 34 valve body, 60 rotor, 62 rotating shaft, 64 stator, 66 can, 76 case, 77 cover, 78 stator unit, 79 engagement portion, 81 tip opening, 90 concave fitting portion, 92 locking surface, 94 fitting recess, 109 screw feed mechanism, 116 spring, 118 circuit board, 119 magnetic sensor, 130 bracket, 132 fitting portion, 134 connection portion, 134a first connection portion, 134b second connection portion, 136 extension portion, 136a First extension portion, 136b second extension portion, 138 connecting portion, 140 abutment portion, 142 first tapered portion, 144 second tapered portion, 146 locking portion, 148 elastic engagement portion, 150 low rigidity portion, 152 notch portion, 153 abutment surface, 154 fitting protrusion, 156 connecting portion, 156a first connecting portion, 156b second connecting portion, 158 insertion hole, 160 notch portion, 200 motor-operated valve device, 210 piping body, 212 inlet port, 214 outlet port, 218 mounting hole, 220 pin, 222 insertion hole, 250 valve assembly, CL clearance, L1 center line, L2 axis line.

Claims

1. a valve body having an inlet port for introducing a fluid, an outlet port for discharging the fluid, and a valve hole for communicating the inlet port with the outlet port; a valve body that opens and closes the valve portion by approaching and separating from the valve hole; 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 is coaxially fixed to the valve body and contains the rotor, the can defining an internal space in which a fluid pressure acts and an external space in which the fluid pressure does not act; A stator unit including a stator that is coaxially inserted into the can; a bracket that fixes the stator unit and the valve body; Equipped with The bracket is a fitting portion that fits into the valve body in a direction perpendicular to an axial direction; a connection portion connected to the stator unit in the axial direction; Including, The fitting portion has a bifurcated structure that opens toward a side surface of the valve body, The bifurcated structure is fitted into a recessed fitting portion formed on the outer circumferential surface of the valve body, The fitting portion is a first extension portion extending in a fitting direction to the valve body; a second extension portion opposed to the first extension portion across the valve body in a radial direction; a connecting portion that connects the first extension portion and the second extension portion at a base end side; Including, a resilient engagement portion that locally narrows a distance between the first extension portion and the second extension portion; The elastic engagement portion overcomes the transverse surface of the valve body, and the fitting portion is fitted to the valve body. The electrically operated valve is characterized in that the elastic engagement portion is elastically deformed and subjected to stress when it overcomes the transverse surface, and the stress is relieved after the elastic engagement portion overcomes the transverse surface.

2. A valve body having an inlet port for introducing a fluid, an outlet port for discharging the fluid, and a valve hole connecting the inlet port and the outlet port; a valve body that opens and closes the valve portion by approaching and separating from the valve hole; 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 is coaxially fixed to the valve body and contains the rotor, the can defining an internal space in which a fluid pressure acts and an external space in which the fluid pressure does not act; A stator unit including a stator that is coaxially inserted into the can; a bracket that fixes the stator unit and the valve body; Equipped with The bracket is a fitting portion that fits into the valve body in a direction perpendicular to an axial direction; a connection portion connected to the stator unit in the axial direction; Including, The fitting portion has a bifurcated structure that opens toward a side surface of the valve body, The bifurcated structure is fitted into a recessed fitting portion formed on the outer circumferential surface of the valve body, The fitting portion is a first extension portion extending in a fitting direction to the valve body; a second extension portion opposed to the first extension portion across the valve body in a radial direction; a connecting portion that connects the first extension portion and the second extension portion at a base end side; Including, a resilient engagement portion that locally narrows a distance between the first extension portion and the second extension portion; The elastic engagement portion overcomes the transverse surface of the valve body, and the fitting portion is fitted to the valve body. The motor-operated valve, wherein the first extension portion and the second extension portion each have a low-rigidity portion having a smaller cross-section on the base end side than the elastic engagement portion than on the tip end side.

3. A valve body having an inlet port for introducing a fluid, an outlet port for discharging the fluid, and a valve hole connecting the inlet port and the outlet port; a valve body that opens and closes the valve portion by approaching and separating from the valve hole; 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 is coaxially fixed to the valve body and contains the rotor, the can defining an internal space in which a fluid pressure acts and an external space in which the fluid pressure does not act; A stator unit including a stator that is coaxially inserted into the can; a bracket that fixes the stator unit and the valve body; Equipped with The bracket is a fitting portion that fits into the valve body in a direction perpendicular to an axial direction; a connection portion connected to the stator unit in the axial direction; Including, The fitting portion has a bifurcated structure that opens toward a side surface of the valve body, The bifurcated structure is fitted into a recessed fitting portion formed on the outer circumferential surface of the valve body, The fitting portion is a first extension portion extending in a fitting direction to the valve body; a second extension portion opposed to the first extension portion across the valve body in a radial direction; a connecting portion that connects the first extension portion and the second extension portion at a base end side; Including, a resilient engagement portion that locally narrows a distance between the first extension portion and the second extension portion; The elastic engagement portion overcomes the transverse surface of the valve body, and the fitting portion is fitted to the valve body. The electrically operated valve, wherein the connecting portion has a notch on a side opposite to the first extension portion and the second extension portion.

4. The connection portion is a first connection portion extending parallel to the first extension portion; a second connection portion spaced apart from the first connection portion and extending parallel to the second extension portion; Including, The bracket is a first connecting portion extending parallel to an axis of the valve body and connecting the first extending portion and the first connecting portion; a second connecting portion extending parallel to an axis of the valve body and spaced apart from the first connecting portion, the second connecting portion connecting the second extension portion and the second connection portion; Further comprising: The motor-operated valve according to any one of claims 1 to 3, characterized in that a tip opening of the stator unit is guided in a gap between each of the first connecting portion and the outer circumferential surface of the valve body and the second connecting portion.

5. 5. The motor-operated valve according to claim 1, wherein the bracket is a press-formed part made of a metal plate.

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