Electric valve

Abstract

The present invention provides an electric valve that can prevent the valve seat member from detaching regardless of fluid pressure, while ensuring coaxiality between the valve body and the valve seat, and between the rotor and the stator. [Solution] An electric valve in one embodiment comprises a valve body 5, an operating rod 32 rotationally driven by a rotor 60, a screw feed mechanism 109 that includes a screw member 6 through which the operating rod 32 is inserted coaxially and converts the rotational motion of the rotor 60 into axial motion of the operating rod 32, and a can 66 enclosing the rotor 60. The valve body 5 includes a valve seat member 8 assembled coaxially with the screw member 6, and a valve housing 7 welded coaxially with the can 66 and housing the connection between the screw member 6 and the valve seat member 8. The screw member 6 is inserted into and fixed in the valve housing 7 with a part of the valve seat member 8 sandwiched axially between it and the valve housing 7.

Description

Technical Field

[0001] The present invention relates to an electric valve, and particularly to a support structure for a valve seat member.

Background Art

[0002] An automotive air conditioner generally includes a compressor, an external heat exchanger, an expansion device, an evaporator, etc. arranged in a refrigeration cycle. In the refrigeration cycle, various control valves are provided to control the flow of refrigerant, such as an expansion valve as the expansion device. With the recent spread of electric vehicles and the like, an electric valve equipped with a motor as a drive unit has been widely adopted.

[0003] When installing an electric valve in a heat exchanger such as an evaporator, a valve unit is assembled to a piping body fixed to the heat exchanger (see Patent Document 1). The valve unit is configured by coaxially assembling a rotor unit that encloses a valve portion and a stator unit that encloses a stator. A fluid passage is provided in the piping body, and a mounting hole is provided so as to communicate with the fluid passage. Then, the valve unit is assembled to the piping body in such a manner that a valve body constituting the rotor unit is inserted into the mounting hole. A male screw portion is provided on the outer peripheral surface of the valve body, and a female screw portion is provided on the inner peripheral surface of the mounting hole. By screwing these screw portions together, the valve body is fastened to the piping body.

[0004] The rotor unit has a can that defines an internal space where fluid pressure acts and an external space where fluid pressure does not act while enclosing a rotor. Since the can is interposed between the rotor and the stator, it needs to be non-magnetic. Generally, from the viewpoint of ensuring airtightness, the can and the valve body are fixed by welding, so both are made of the same kind of metal material (stainless steel).

[0005] However, stainless steel is generally considered a difficult material to machine because its high viscosity makes it difficult to achieve high cutting accuracy, and the chips tend to stick together, requiring sequential removal. On the other hand, the valve seat, which is installed in the valve body, constitutes the valve itself, and therefore requires high-precision machining to match the shape of the valve body. For this reason, when cutting out valve bodies with complex shapes, not only is the yield poor, but the processing time is also long, resulting in higher manufacturing costs.

[0006] Therefore, the valve body is divided into a valve housing and a valve seat member, the valve housing is made from the same material as the can, and the valve seat member is made from a material with excellent machinability. A valve seat is formed on the valve seat member. The valve body is obtained by assembling the valve housing and the valve seat member coaxially. The valve housing is welded to the can.

[0007] Meanwhile, a threaded member is coaxially assembled to the valve housing. An operating rod extending coaxially from the rotor passes through the threaded member, and a valve body is provided at the tip of the operating rod. The threaded member supports the operating rod so that it can slide in the axial direction and constitutes a screw feed mechanism that converts the rotational motion of the rotor into the axial motion of the valve body. The valve opens and closes as the valve body attaches to and detaches from the valve seat through the operation of the screw feed mechanism. Since the threads that constitute the screw feed mechanism are formed on the threaded member, a metal material with excellent machinability is selected as its material.

[0008] In this electric valve, both the valve seat member and the threaded member are mounted coaxially to the valve housing. As a result, the valve seat member and the threaded member are also coaxial, ensuring coaxiality between the valve body and the valve seat. Furthermore, the coaxial mounting of the valve housing and the can ensures coaxiality between the threaded member and the can, and also ensures coaxiality between the rotor and the stator. Consequently, the drive of the valve body is stabilized, enabling highly precise opening and closing control of the valve. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2023-53708 [Overview of the project] [Problems that the invention aims to solve]

[0010] Incidentally, in the electric valve described in Patent Document 1, the valve housing and the valve seat member are fixed by crimping. The valve seat member is fixed by crimping the tip of the valve housing slightly inward. On the other hand, the valve seat member is provided with a fluid inlet port and an outlet port, and a differential pressure acts on the valve seat member in the direction away from the valve housing (away from the threaded member). For this reason, if a high-pressure refrigerant such as carbon dioxide is used as the refrigerant, for example, there was a concern that if the differential pressure became too large, the crimped joint would break and the valve seat member would fall off the valve housing.

[0011] One of the objectives of the present invention is to provide an electric valve that can prevent the valve seat member from detaching regardless of fluid pressure, while ensuring coaxiality between the valve body and the valve seat, and between the rotor and the stator. [Means for solving the problem]

[0012] An electric valve according to one aspect of the present invention comprises a valve body provided with a valve seat; a valve element that is detachably attached to the valve seat to open and close the valve; an operating rod axially coupled to the valve element and rotationally driven by a rotor; a screw feed mechanism including a screw member through which the operating rod is inserted coaxially, which converts the rotational motion of the rotor into axial motion of the operating rod; and a cylindrical member enclosing the rotor, which defines an internal space on which fluid pressure acts and an external space on which it does not. The valve body includes a valve seat member provided with a valve seat and assembled coaxially with the screw member; and a valve housing welded coaxially with the can and housing the connection between the screw member and the valve seat member. The screw member is inserted into and fixed in the valve housing with a portion of the valve seat member axially sandwiched between it and the valve housing.

[0013] In this configuration, the threaded member and the valve seat member are directly assembled, making it easier to ensure coaxiality between the two members. Furthermore, since only the valve housing is interposed between the threaded member, which is coaxial with the rotor, and the can, which is coaxial with the stator, it is also easier to ensure coaxiality between the rotor and the stator. In addition, since a portion of the valve seat member is supported axially between the threaded member and the valve housing, it is possible to prevent the valve seat member from detaching even when large fluid pressure is applied. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an electric valve that can prevent the valve seat member from detaching regardless of fluid pressure, while ensuring the coaxiality between the valve body and the valve seat, and between the rotor and the stator. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view showing the structure of the electric valve according to the first embodiment. [Figure 2] This is an enlarged view of section A in Figure 1. [Figure 3] This is an enlarged view of section B in Figure 2. [Figure 4] This diagram shows the structure of the connection between the valve body and the operating rod. [Figure 5] This diagram shows the stopper mechanism in a functional state. [Figure 6] This is a partially enlarged view showing the support structure of a valve seat member in a modified form. [Figure 7] This is a cross-sectional view showing the structure of an electric valve according to the second embodiment. [Figure 8] This is an enlarged view of section C in Figure 7. [Figure 9] This is a cross-sectional view showing the structure of an electric valve according to the third embodiment. [Figure 10] This is an enlarged view of section A in Figure 9. [Figure 11] This diagram illustrates the assembly method of the stator unit. [Figure 12] This diagram illustrates the assembly method of the stator unit. [Figure 13] This is a diagram showing the function of the pressing member in detail. [Figure 14] This is a diagram showing the function of the pressing member in detail. [Figure 15] This is a diagram showing the function of the pressing member in detail. [Figure 16] This is a diagram showing the function of the pressing member in detail. [Figure 17] This is a cross-sectional view showing the structure of the electric valve according to the modified example. [Figure 18] This is a diagram showing the mounting structure of the hole. [Figure 19] This is a diagram showing the assembling method of the stator unit.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments 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. Also, for the following embodiments and their modified examples, substantially the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0017] [First Embodiment] FIG. 1 is a cross-sectional view showing the structure of the electric valve according to the first embodiment. The electric valve 1 is applied to the refrigeration cycle of an automotive air conditioner (not shown). In this refrigeration cycle, a compressor for compressing the circulating refrigerant, a condenser for condensing the compressed refrigerant, an expansion valve for throttling and expanding the condensed refrigerant and sending it out in a mist form, an evaporator for evaporating the mist-like refrigerant and cooling the air in the vehicle interior by its latent heat of evaporation, etc. are provided. The electric valve 1 can function as the expansion valve.

[0018] The electric valve 1 is constructed 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 as drive units. 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 connecting member 101. The connecting 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.

[0019] The passage body 200 is made of a metal such as an aluminum alloy and has a roughly rectangular prism shape. An inlet port 202 and an outlet port 204 are provided on the side of the passage body 200. Piping extending from the condenser side is connected to the inlet port 202, and piping leading to the evaporator inlet is connected to the outlet port 204.

[0020] A fluid passage 210 is formed in the passage body 200, connecting the inlet port 202 and the outlet port 204. The passage body 200 encloses the valve portion of the valve unit 100 midway through the fluid passage 210. A mounting hole 216 opens upward at the top of the passage body 200. The mounting hole 216 communicates with the fluid passage 210. A step is provided slightly below the opening end of the mounting hole 216, and a female thread 218 is formed in this step.

[0021] The valve unit 100 is constructed 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 by each being fixed to the passage body 200. The rotor unit 90 has a valve body 5 that encloses the valve section.

[0022] The valve body 5 is constructed by coaxially assembling the valve housing 7 and the valve seat member 8. A guide member 6 is coaxially assembled to the valve body 5. The guide member 6 is cylindrical, and an internal thread 40 is formed on its upper inner surface. The guide member 6 functions as a "threaded member". The valve seat member 8 has a stepped cylindrical body, and a valve seat 24 is formed at its lower part. The upper end of the valve seat member 8 is press-fitted into the lower end of the guide member 6. A seal ring 20 (O-ring) is fitted to the lower outer surface of the valve seat member 8.

[0023] An inlet port 26 is provided on the side of the valve seat member 8, and an outlet port 28 is provided at the bottom of the valve seat member 8. The inlet port 26 communicates with the introduction port 202, and the outlet port 28 communicates with the outlet port 204. A valve chamber 30 is formed inside the valve seat member 8. The inlet port 26 and the outlet port 28 communicate via the valve chamber 30 to form an internal passage of the valve body 5, and this internal passage constitutes part of the fluid passage 210.

[0024] The valve housing 7 is a cylindrical press-formed product and is assembled to house (cover from the outside) the connection between the guide member 6 and the valve seat member 8. A male thread 10 that can be screwed into a female thread 218 is formed on the lower outer circumference of the valve housing 7. 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 10 and the female thread 218 are screwed together to fasten the valve body 5 to the passage body 200.

[0025] An annular seal housing portion 222 (annular groove) is provided on the upper surface of the passage body 200, surrounding the mounting hole 216, and a seal ring 220 (O-ring) is fitted into it. 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 restricts the leakage of refrigerant from the inside to the outside of the passage body 200. The seal ring 20 seals the space between the upstream passage 230 and the downstream passage 232 of the valve section.

[0026] An operating rod 32 extending from the rotor 60 of the rotor unit 90 is inserted inside the valve body 5. A valve body 34 is detachably connected to the lower end of the operating rod 32 (details will be described later). The valve body 34 attaches to and detaches from the valve seat 24 from the valve chamber 30 side to open and close the valve and, consequently, the fluid passage 210. The operating rod 32 is obtained by machining a rod made of a non-magnetic metal, and a male thread 38 is formed on the outer circumferential surface of its axial center. The male thread 38 meshes with the female thread 40 of the guide member 6. Through the screw feeding mechanism 109 of these threaded parts, the rotational motion of the rotor 60 is converted into axial motion of the operating rod 32. The operating rod 32 is rotationally driven by the rotor 60 and displaced in the axial direction. As a result, the valve body 34 moves (up and down) in the axial direction, that is, in the opening and closing direction of the valve.

[0027] 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 bottomed cylindrical can 66, and the rotor 60 is positioned inside the can 66. The stator 64 is positioned outside the can 66. The can 66 is a component that covers the space in which the valve body 34 and its drive mechanism are positioned and encloses the rotor 60, defining an inner pressure space (internal space) where the refrigerant pressure acts and an outer non-pressure space (external space) where it does not act.

[0028] In this embodiment, the can 66 is made of stainless steel (hereinafter referred to as "SUS"), which is a non-magnetic metal, and its lower end is fitted into the upper end of the valve housing 7. The valve body 5 and the can 66 are fixed together by welding (circumferential welding) along the boundary between the can 66 and the valve housing 7 (not shown), and airtightness (seal) between them is ensured. The above-mentioned pressure space is formed between the can 66 and the valve housing 7.

[0029] The stator 64 is constructed by assembling a bobbin 70 around which a coil 68 is wound onto a yoke 72 having multiple pole teeth. The stator 64 is housed in a case 76. The case 76 is obtained by injection molding of a corrosion-resistant resin material. The stator unit 92 has a hollow structure, and the stator 64 is assembled to the rotor unit 90 with the can 66 coaxially inserted through it. The weld between the can 66 and the valve body 5 is located inside the case 76.

[0030] The rotor 60 comprises a disc-shaped end member 102 attached to the operating rod 32 and a rotor magnet 104 attached to the outer circumferential surface of the end member 102. The rotor magnet 104 is cylindrical and magnetized (applied magnets) to multiple poles in its circumferential direction. The end member 102 is coaxially fixed to the upper part of the operating rod 32. A relatively large annular space S1 is formed between the inner circumferential surface of the rotor magnet 104 and the outer circumferential surface of the guide member 6. The operating rod 32 passes through the end member 102 and extends upward above the rotor 60.

[0031] 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 that function as control and communication units are mounted on the underside of the circuit board 118. Specifically, a drive circuit for driving the motor, a control circuit (microcomputer) that outputs control signals to the drive circuit, a communication circuit for the control circuit to communicate with external devices, and a power supply circuit for supplying power to each circuit and the motor (coil) are mounted. The upper end of the case 76 is closed by a resin cover 77. The circuit board 118 is arranged in the space below the cover 77 in the case 76.

[0032] A seal ring 21 (O-ring) is interposed between the inner circumferential surface of the lower end of case 76 and the outer circumferential surface of the lower end of can 66. This prevents moisture from entering the stator unit 92 from the outside.

[0033] A terminal 69 extends from the bobbin 70 and connects to the coil 68, and is connected to the circuit board 118. Power lines, ground lines, and communication lines are formed on the circuit board 118, and terminal elements 120 are connected to them. The terminal elements 120 are constructed by resin-molding power terminals connected to the power lines, ground terminals connected to the ground lines, and communication terminals connected to the communication lines (collectively referred to as "connection terminals 122") into their main body. A connector section 124 is integrally provided on the side of the case 76, and the terminal elements 120 are assembled inside the connector section 124.

[0034] When assembling the stator unit 92, the terminal element 120 is assembled by inserting it into the connector portion 124 from the inside of the case 76, and then the stator 64 is housed in the case 76. After that, the retaining member 119 is inserted into the case 76 from above the stator 64 and fixed in place. The retaining member 119 is made of a plate material with an L-shaped cross-section and supports the stator 64 by pressing it from above, and also supports the terminal element 120 by pressing it from behind. The terminal 69 passes through the retaining member 119 in the vertical direction. Then, the circuit board 118 is inserted from above the case 76 and fixed in place while connecting it to the terminal 69 and the connection terminal 122. The upper end opening of the case 76 is closed with the cover 77.

[0035] Figure 2 is an enlarged view of section A in Figure 1. Figure 3 is an enlarged view of section B in Figure 2. As shown in Figure 2, the guide member 6 is made of a metal with excellent machinability, such as brass, and the valve seat member 8 is made of a metal with excellent wear resistance, such as stainless steel. The guide member 6 has a stepped cylindrical shape, with its inner diameter decreasing at the top and its outer diameter decreasing slightly at the bottom. A female thread 40 is formed on the inner circumferential surface of its upper part. Its lower part is press-fitted into the valve housing 7. A communication hole 128 is provided on the side of the guide member 6 to connect the inside and outside.

[0036] The inner diameter of the lower end of the guide member 6 is slightly enlarged, and the upper end of the valve seat member 8 is press-fitted into it. A flange portion 130 projecting radially outward is provided on the upper outer circumferential surface of the valve seat member 8. The outer diameter of the flange portion 130 is slightly smaller than the outer diameter of the lower end of the guide member 6. The upper surface of this flange portion 130 is locked to the lower surface of the guide member 6, thereby restricting the amount of press-fitting of the valve seat member 8.

[0037] On the other hand, a flange portion 132 is provided at the lower end of the valve housing 7, projecting radially inward. The inner diameter of the flange portion 132 is larger than the outer diameter of the portion of the valve seat member 8 below the flange portion 130, and smaller than the outer diameter of the flange portion 130. The lower surface of the flange portion 130 is locked to the upper surface of the flange portion 132, thereby supporting the valve seat member 8 from below. The flange portion 132 is provided at the end of the valve housing 7 opposite to the connection portion with the can 66, and projects toward the valve seat member 8. The flange portion 132 functions as a "locking portion" that locks a part of the valve seat member 8 in the axial direction. Furthermore, the locking of the flange portion 132 to the flange portion 130 also restricts the amount of press-fitting of the guide member 6 into the valve housing 7.

[0038] As shown in Figure 3, the lower part of the guide member 6 is inserted (press-fitted) into the inside of the valve housing 7, and the upper end of the valve seat member 8 is inserted (press-fitted) into the inside of the lower end of the guide member 6. The flange portion 132 overlaps with the lower end surface of the guide member 6 when viewed in the axial direction. The guide member 6 is inserted and fixed into the valve housing 7 with the flange portion 130 sandwiched between it and the valve housing 7 in the axial direction. In other words, the valve seat member 8 is supported in the axial direction in such a way that a convex portion (flange portion 130) that protrudes radially outward from its outer circumference is sandwiched between the guide member 6 and the valve housing 7, thus preventing it from falling out of the valve housing 7.

[0039] In this configuration of the valve body 5, the outer diameter of the lower end of the guide member 6 is slightly reduced, and the press-fit portion 134 of the guide member 6 is located in the upper half of the valve housing 7. On the other hand, the male thread 10 is located in the lower half of the valve housing 7. That is, the press-fit portion 134 is located above the male thread 10 and is offset in the axial direction from its threaded portion (the threaded portion between the male thread 10 and the female thread 218). This prevents the valve housing 7 from expanding radially at the threaded portion during the press-fitting process, ensuring that there is no interference with the threading of the male thread 10 and the female thread 218.

[0040] The valve housing 7 has a flange portion 136 extending radially outward from its upper end. An annular step 138 is formed on the outer peripheral edge of the upper surface of the flange portion 136. The can 66 is assembled coaxially with the valve body 5 by fitting its lower end opening into the step 138. Full-circumference welding is performed along the boundary between the can 66 and the flange portion 136. To ensure weldability between the two, the can 66 and the valve housing 7 are made of the same type of metal.

[0041] Returning to Figure 2, the valve seat member 8 has a bottomed cylindrical body, with a valve hole 22 and a valve seat 24 formed at the lower part of the body. The inlet port 26 is formed on the side of the body (cylindrical portion) of the valve seat member 8. The pressure of the fluid introduced into the valve chamber 30 through the inlet port 26 is also guided into the internal space of the can 66 through the communication hole 128.

[0042] The valve body 34 has a stepped cylindrical shape, and the tapered surface formed on its lower half is the attachment / detachment surface 34a for attaching to and detaching from the valve seat 24. A flange portion 140 projecting radially outward is provided on the outer circumferential surface of the upper half of the valve body 34. A connecting member 142 for operating connection with the operating rod 32 is assembled to the upper part of the valve body 34.

[0043] The connecting member 142 is a cylindrical member that is coaxially assembled and fixed to the valve body 34. The upper part of the valve body 34 is press-fitted into the lower part of the connecting member 142. The amount of press-fitting is restricted by the upper surface of the flange portion 140 being locked to the lower surface of the connecting member 142. The upper end of the connecting member 142 is reduced in diameter to form a guide portion 144. The lower part of the operating rod 32 slides through the guide portion 144.

[0044] An annular locking member 146 is coaxially fitted onto and fixed to the tip of the operating rod 32. The locking member 146 functions as a "locking portion" that protrudes radially from the side surface of the operating rod 32. The locking member 146 is press-fitted into the tip of the operating rod 32 and housed in a housing space S2 surrounded by the valve body 34 and the connecting member 142. The connecting member 142 is slidably supported on the operating rod 32. In this embodiment, the connecting member 142 slides relative to the operating rod 32 at the position of the guide portion 144, but it may also slide relative to the locking member 146.

[0045] A spring 148 (biasing member) is interposed between the connecting member 142 and the guide member 6 to bias the valve body 34 in the closing direction. The biasing force of the spring 148 is transmitted to the valve body 34 via the connecting member 142. When the valve is opened, the locking member 146 contacts and pushes up against the bottom surface (locking surface) of the connecting member 142, causing the valve body 34 to move in the opening direction.

[0046] The upper part of the operating rod 32 is provided with a notch 150 (a so-called H-cut structure) having a pair of surfaces parallel to the axis. On the other hand, the central part of the end member 102 is provided with an insertion hole 152 that is complementary in shape to the notch 150. A circular boss-shaped guide portion 154 is provided protruding from the center of the lower surface of the end member 102. The upper part of the operating rod 32 is press-fitted into the guide portion 154, and the notch 150 is inserted through the insertion hole 152.

[0047] This press-fit structure prevents the operating rod 32 from separating from the end member 102. Furthermore, the fitting structure between the notch 150 and the insertion hole 152 restricts the rotation of the operating rod 32 relative to the rotor 60. The operating rod 32 functions as the rotation axis of the rotor 60 and rotates integrally with the rotor 60. Note that a D-cut structure or other anti-rotation structure may be used instead of the H-cut structure.

[0048] Figure 4 shows the structure of the connection between the valve body 34 and the operating rod 32. The upper bottom surface of the connecting member 142 forms a locking surface 160. The locking surface 160 faces the locking member 146 axially from the opposite side of the valve body 34. In the open state, the tip surface of the operating rod 32 is separated from the upper end surface 162 of the valve body 34, and the locking member 146 contacts the locking surface 160. On the other hand, in the closed state, the locking member 146 is separated from the locking surface 160. The rotation of the rotor 60 is restricted by the tip surface of the operating rod 32 contacting the upper end surface 162 of the valve body 34. In other words, the tip surface of the operating rod 32 and the upper end surface 162 of the valve body 34 constitute a "stopper mechanism" that restricts the displacement of the operating rod 32 in the valve closing direction.

[0049] In this case, the tip surface of the operating rod 32 abuts against the upper end surface 162 of the valve body 34 on its central axis L. In this embodiment, the tip surface of the operating rod 32 has a curved surface that moves further away from the upper end surface 162 of the valve body 34 as it moves away from the central axis L. Specifically, since the tip of the operating rod 32 is spherical, the operating rod 32 and the valve body 34 abut in a point contact manner.

[0050] The locking member 146 has a lower surface 146a and an upper surface 146b located at a distance from the central axis L. The lower surface 146a corresponds to the "first end surface" and faces the upper end surface 162 of the valve body 34 in the axial direction. The upper surface 146b corresponds to the "second end surface" and faces the locking surface 160 in the axial direction. As shown in the figure, the operating rod 32 protrudes downward from the lower surface 146a of the locking member 146. By adjusting the amount P of protrusion of this operating rod 32, the axial clearance CL between the locking member 146 and the connecting member 142 at the operating origin (reference position) is set.

[0051] This clearance CL corresponds to the number of drive steps from when the electric valve 1 starts closing at the seating point until it reaches the operating origin (reference position), that is, from when the valve body 34 seats on the valve seat 24 until the rotation of the rotor 60 is restricted. More specifically, the sum of the clearance CL and the backlash of the threaded portion corresponds to that number of drive steps.

[0052] More specifically, as shown in the figure, if A is the height of the accommodating space S2 in the connecting member 142 (i.e., the distance between the locking surface 160 and the bottom surface of the connecting member 142), B is the insertion height of the valve body 34 into the connecting member 142 (i.e., the height from the top surface of the flange portion 140 to the upper end surface 162 of the valve body 34), and C is the axial length of the locking member 146, then the clearance CL is expressed by the following formula (1). CL = ABCP …(1)

[0053] Therefore, even if there are variations in the dimensions of any of the valve body 34, connecting member 142, or locking member 146, the clearance CL can be adjusted to a preset value (also called the "set clearance") by measuring the dimensions of these parts and then adjusting the protrusion amount P of the operating rod 32.

[0054] Returning to Figure 1, the electric valve 1 configured as described above functions as an electric expansion valve whose valve opening degree can be adjusted by drive control of the rotor unit 90. Based on a command from an external device (not shown), the control unit sets a control amount (number of motor drive steps) to achieve the target opening degree and outputs a drive signal to the drive circuit to achieve this. The drive circuit supplies two-phase drive current (drive pulse) to each coil 68 at the set timing. As a result, the rotor 60 rotates with high resolution. At this time, if the valve body 34 is in an open state separated from the valve seat 24, the locking member 146 comes into contact with the connecting member 142 due to the biasing force of the spring 148, and the operating rod 32 and thus the valve body 34 operate together with the rotor 60 (see Figure 5(B)).

[0055] The rotor 60 moves vertically by the screw feed mechanism 109. The valve body 34 translates in the opening and closing direction of the valve, and the opening degree of the valve is adjusted to the set opening degree. The screw feed mechanism 109 converts the rotational motion of the rotor 60 around its axis into axial motion (linear motion) of the actuating rod 32, driving the valve body 34 in the opening and closing direction of the valve. When the electric valve 1 functions as an expansion valve, the valve is controlled to a small opening degree.

[0056] Figure 5 shows the state in which the stopper mechanism is functioning. Figure 5(A) shows the state when the valve is closed, and Figure 5(B) shows the state when it is fully open.

[0057] As shown in Figure 5(A), when the valve is closed, after the valve body 34 seats on the valve seat 24, the operating rod 32 is displaced relative to the connecting member 142 toward the valve body 34, and the locking member 146 separates from the locking surface 160. This releases the operating connection between the operating rod 32 and the valve body 34. Then, when the rotor 60 reaches the operating origin (reference position), the tip surface of the operating rod 32 comes into contact with the upper end surface 162 of the valve body 34, as shown in the figure, thereby restricting the rotation of the rotor 60.

[0058] At this time, the tip surface of the operating rod 32 abuts against the upper end surface 162 of the valve body 34 on its central axis L. Because the tip of the operating rod 32 is spherical, the operating rod 32 and the valve body 34 abut in a point contact manner. As a result, the outer diameter of the contact surface between the operating rod 32 and the valve body 34 can be reduced, and frictional torque can be reduced.

[0059] On the other hand, as shown in Figure 5(B), when the valve is opened, the tip surface of the operating rod 32 separates from the upper end surface 162 of the valve body 34, and the locking member 146 contacts the locking surface 160, thereby connecting the operating rod 32 and the valve body 34. As the rotor 60 rotates, the operating rod 32 and the valve body 34 are displaced together. When fully open, the rear end surface (upper end surface) of the operating rod 32 contacts the upper bottom surface 164 of the can 66 on its central axis L.

[0060] Since the rear end surface of the operating rod 32 is also spherical, the operating rod 32 and the cann 66 come into contact at a point. As a result, the outer diameter of the contact surface between the operating rod 32 and the cann 66 can be reduced, thereby reducing frictional torque.

[0061] As explained above, in this embodiment, since the guide member 6 and the valve seat member 8 are directly connected, it is easy to ensure the coaxiality of both members. Furthermore, since only the valve housing 7 is interposed between the guide member 6, which is coaxial with the rotor 60, and the can 66, which is coaxial with the stator 64, it is easy to ensure the coaxiality of the rotor 60 and the stator 64.

[0062] In particular, in the electric valve 1, since upstream pressure is introduced into the valve chamber 30, a differential pressure (fluid pressure) acts on the valve seat member 8 in the direction of separation from the valve housing 7 (in the direction of separation from the guide member 6). In this regard, since the flange portion 130, which is part of the valve seat member 8, is supported in a state where it is sandwiched axially between the guide member 6 and the valve housing 7, it is possible to prevent the valve seat member 8 from separating even if a large differential pressure is applied.

[0063] [Differentiation] Figure 6 is a partially enlarged view showing the support structure of the valve seat member according to a modified example, and corresponds to Figure 3. In the above embodiment, as shown in Figure 3, the guide member 6 and the valve housing 7 are shown in a configuration in which the guide member 6 and the valve housing 7 sandwich the flange portion 130, with the lower surface of the guide member 6 in contact with the upper surface of the flange portion 130 and the upper surface of the flange portion 132 in contact with the lower surface of the flange portion 130. In a modified example, as shown in Figure 6(A), the guide member 6 and the valve housing 7 may sandwich the upper part of the valve seat member 8, with the lower surface of the guide member 6 in contact with the upper end surface of the valve seat member 8 and the upper surface of the flange portion 132 in contact with the lower surface of the flange portion 130.

[0064] Alternatively, as shown in Figure 6(B), the upper part of the valve seat member 8 may be sandwiched vertically between the guide member 6 and the valve housing 7, but the upper surface of the valve seat member 8 may not be in contact with the lower surface of the guide member 6, thus avoiding clamping. Even in this configuration, the upper part of the valve seat member 8 is press-fitted into the lower end of the guide member 6, so the valve seat member 8 can be fixed to the guide member 6. On the other hand, since the flange portion 130 is hooked onto the flange portion 132, the valve seat member 8 can be prevented from coming off even if a large differential pressure is applied.

[0065] [Second Embodiment] Figure 7 is a cross-sectional view showing the structure of the electric valve according to the second embodiment. Figure 8 is an enlarged view of section C in Figure 7. The electric valve of this embodiment has a configuration in which the support structure of the valve seat member of the first embodiment is applied to the electric valve of Patent Document 1 (Japanese Patent Application Publication No. 2023-53708). The following will mainly describe the characteristic differences when compared with the first embodiment.

[0066] As shown in Figure 7, the electric valve 201 is constructed by assembling a valve unit 300 and a passage body 200. The valve unit 300 includes a rotor unit 390 and a stator unit 392. The rotor unit 390 has a valve body 305. The valve body 305 is constructed by coaxially assembling a valve housing 307 and a valve seat member 308. A guide member 306 is coaxially assembled to the valve body 305.

[0067] The valve housing 307 accommodates the connection between the guide member 306 and the valve seat member 308. An operating rod 332 extending from the rotor 360 of the rotor unit 390 is inserted inside the valve body 305. A needle-shaped valve body 34 is integrally provided at the lower part of the operating rod 332. The guide member 306 functions as a "threaded member".

[0068] The valve housing 307 differs from the valve housing 7 of the first embodiment in that it is not a press-formed product. The valve housing 307 has a stepped cylindrical shape in which the outer diameter decreases towards the bottom. A step is formed at the upper end of the valve housing 307, and the can 66 is assembled and welded to it. The lower half of the inner circumferential surface of the valve housing 307 has a slightly smaller diameter, and a stepped portion 310 is formed therein.

[0069] The valve seat member 308 has substantially the same configuration as the valve seat member 8 of the first embodiment. A flange portion 130 is provided on the upper outer peripheral surface of the valve seat member 308.

[0070] The guide member 306 has a male thread 38 formed on its outer circumferential surface at its axial center. The guide member 306 supports the operating rod 332 so that it can slide in the axial direction with its inner circumferential surface, while supporting the rotating shaft 362 of the rotor 360 so that it can rotate and slide with its outer circumferential surface. The rotating shaft 362 is a bottomed cylindrical shaft and is externally fitted onto the guide member 306 with its open end facing downwards. A female thread 40 is formed on the lower inner circumferential surface of the rotating shaft 362 and engages with the male thread 38 of the guide member 306. These threaded parts constitute the screw feeding mechanism 109.

[0071] As shown in Figure 8, the lower surface of the flange portion 130 is locked to the stepped portion 310, thereby supporting the valve seat member 308 from below. The flange portion 130 is sandwiched between the lower end surface of the guide member 306 and the stepped portion 310. The stepped portion 310 protrudes toward the valve seat member 308 and functions as a "locking portion" that locks a part of the valve seat member 308 in the axial direction.

[0072] The lower part of the guide member 306 is inserted (press-fitted) into the inside of the valve housing 307, and the upper part of the valve seat member 308 is inserted (press-fitted) into the inside of the lower end of the guide member 306. The guide member 306 is inserted into and fixed to the valve housing 307 with the flange portion 130 sandwiched between it and the valve housing 307 in the axial direction. The valve seat member 308 is supported in the axial direction in such a manner that the flange portion 130 is sandwiched between the guide member 306 and the valve housing 307, thus preventing it from falling out of the valve housing 307.

[0073] In this embodiment as well, the press-fit portion 134 of the guide member 6 is located above the male thread 10 and is offset axially from the threaded portion (the screw-fitting portion between the male thread 10 and the female thread 218). This prevents the valve housing 307 from expanding radially at the position of the threaded portion during the press-fitting process.

[0074] Since the guide member 306 and the valve seat member 308 are directly assembled, it is easy to ensure the coaxiality of both members. Furthermore, since only the valve housing 307 is interposed between the guide member 306, which is coaxial with the rotor 360, and the can 66, which is coaxial with the stator 364, it is easy to ensure the coaxiality of the rotor 360 and the stator 364.

[0075] When the valve is opened, upstream pressure is introduced into the valve chamber 30, so a differential pressure (fluid pressure) acts on the valve seat member 308 in the opposite direction to that of the valve housing 307. In this regard, since the flange portion 130, which is part of the valve seat member 308, is supported in an axial position between the guide member 306 and the valve housing 307, the valve seat member 308 can be prevented from detaching even if a large differential pressure is applied.

[0076] [Third Embodiment] Figure 9 is a cross-sectional view showing the structure of the electric valve according to the third embodiment. Figure 10 is an enlarged view of part A in Figure 9. As shown in Figure 9, the electric valve 301 of this embodiment differs from the first embodiment in the fixing structure of the stator 64 and terminal element 420 by the retaining member 430. The differences from the first embodiment will be explained below.

[0077] The electric valve 301 is constructed by assembling a valve unit 302 and a passage body 260. The valve unit 302 includes a rotor unit 490 and a stator unit 492. The rotor unit 490 has a valve body 5.

[0078] In this embodiment as well, the terminal element 420 is assembled inside the connector portion 124. The case 76 has a partition wall 412 that separates the internal space S31 of its main body 410 from the internal space S32 of the connector portion 124. A mounting hole 414 is provided so as to penetrate the partition wall 412. The mounting hole 414 connects the internal space S31 and the internal space S32.

[0079] The terminal element 420 is inserted and fitted into the mounting hole 414. A flange-shaped locking portion 416 is provided at the rear end of the terminal element 420. The locking portion 416 is locked to the open end of the mounting hole 414 (the inner surface of the main body 410), thereby positioning the terminal element 420 in the case 76. The retaining member 430 supports the stator 64 by pressing it from above and also supports the terminal element 420 by pressing it from the rear (details will be described later).

[0080] A seal structure 270 is provided at the boundary between the valve unit 302 and the passage body 260. The seal structure 270 includes a first seal structure 272 that restricts the leakage of refrigerant from the inside of the electric valve 301 to the outside, and a second seal structure 274 (waterproof structure) that restricts the intrusion of outside air into the inside of the electric valve 1. On the upper surface of the passage body 260, that is, the surface axially opposite to the valve unit 302, a stepped portion 276 is provided which has a recess surrounding the mounting hole 216. The seal rings that constitute the first seal structure 272 and the second seal structure 274 are arranged on the stepped portion 276.

[0081] As shown in Figure 10, a flange-shaped spring retainer 32a, projecting radially outward, is provided at the axial center of the operating rod 32 (below the male screw 38). A spring 149, which biases the valve body 34 in the closing direction, is also interposed between the spring retainer 32a and the connecting member 142. The spring 149 is inserted coaxially with the spring 148. The biasing force of the spring 149 is transmitted to the valve body 34 via the connecting member 142.

[0082] A reference position is set for the operating rod 32, which serves as the basis for control. After the rotor 60 continues to rotate in the valve closing direction and the valve body 34 seats on the valve seat 24, when it rotates a small amount further from the seating point to reach a reference position also called the "operating origin," the rotor 60's rotation is restricted by the stopper mechanism 460. The stopper mechanism 460 includes a first locking member 462 assembled to the guide member 6 and a second locking member 464 assembled to the operating rod 32. The stopper mechanism 460 is a rotation stopper that restricts the displacement of the operating rod 32 in the valve closing direction by having the first locking member 462 lock the second locking member 464 in the rotational direction at the operating origin.

[0083] The first locking member 462 has a cylindrical body 166 and a flange portion 168 that protrudes radially inward from the upper end of the body 166, and is assembled to fit onto the upper end of the guide member 6. The body 166 is press-fitted coaxially onto the upper end of the guide member 6. The flange portion 168 catches on the upper surface of the guide member 6, thereby axially positioning the first locking member 462 relative to the guide member 6. A locking portion 170 is provided at one point on the inner circumferential surface of the flange portion 168. The locking portion 170 extends radially inward.

[0084] On the other hand, the second locking member 464 has an annular body 172 that is fitted onto the operating rod 32, and a locked portion 174 that protrudes radially outward from the outer peripheral edge of the body 172. The body 172 is press-fitted onto the upper part of the operating rod 32, and the second locking member 464 is displaced integrally with the operating rod 32. As shown in the figure, the two engage when the second locking member 464 is at a height position that overlaps with the first locking member 462. When the rotor 60 reaches the operating origin during valve closing operation, the locked portion 170 locks the locked portion 174 in the rotational direction, thereby restricting the rotation of the operating rod 32 and, consequently, the rotor 60.

[0085] During valve opening, the spring 149 is compressed between the spring receiver 32a and the guide portion 144, and its length does not change, so it is essentially non-functional. On the other hand, during valve closing, after the valve body 34 seats on the valve seat 24, the operating rod 32 is displaced relative to the connecting member 142 from its seating position (seat point), causing the spring 149 to compress and increasing its spring load. This spring load acts as resistance, reducing the impact noise generated when the stopper mechanism 460 in the valve closing direction functions (i.e., when the second locking member 464 is locked to the first locking member 462). Furthermore, the load on the outer spring 148 is suppressed while the load on the inner spring 149 maintains a stable closed state. By suppressing the load on the outer spring 148, good valve opening performance can be maintained.

[0086] As described above, the seal structure 270 includes a first seal structure 272 and a second seal structure 274. The first seal structure 272 includes a seal ring 220 (O-ring). A seal housing portion 222 is provided on the bottom surface 276a of the stepped portion 276 in the passage body 260, surrounding the mounting hole 216, and a seal ring 240 is fitted into it. When the valve body 5 is fastened to the passage body 260, the seal ring 220 is interposed between the upper surface of the passage body 260 and the valve body 5, more specifically between the bottom surface 276a of the stepped portion 276 and the opposing surfaces of the flange portion 136. The seal ring 220 restricts the leakage of refrigerant from the inside to the outside of the passage body 260.

[0087] The second seal structure 274 includes a seal ring 250 (O-ring), a spacer 252, and a seal ring 254 (O-ring). These components are coaxially externally fitted to the can 66 and arranged continuously in the axial direction. The seal ring 250 is interposed between the inner circumferential surface of the case 76 in the stator unit 92 and the outer circumferential surface of the can 66, restricting the intrusion of outside air (moisture) into the interior of the stator unit 92. The seal ring 254 is interposed between the inner circumferential surface of the stepped portion 276 in the passage body 260 and the outer circumferential surface of the can 66, restricting the intrusion of outside air (moisture) into the space S3 where the welded portion W between the valve housing 7 and the can 66 is located.

[0088] The spacer 252 has an annular spacer body 256 that is fitted onto the can 66, and a flange portion 258 that protrudes radially outward from the outer circumferential surface of the spacer body 256. The spacer body 256 is positioned between the seal rings 250 and 254 so as to separate them in the axial direction. The flange portion 258 is sandwiched and locked between the axially opposing surfaces of the case 76 and the stepped portion 276, thereby positioning the stator unit 492 relative to the passage body 260.

[0089] Figures 11 and 12 illustrate the assembly method of the stator unit 492. Figures (A) to (C) show the assembly process. As described in the first embodiment above, when assembling the stator unit 492, the terminal element 420 is first assembled by inserting it into the mounting hole 414 from inside the case 76 (Figure 11(A)). At this time, the multiple connection terminals 122 (which function as "second terminals") are aligned side by side, with one end exposed to the internal space S32 of the connector portion 124 and the other end exposed to the internal space S31 of the main body 410. As shown in the figure, the connection terminals 122 are L-shaped, so one end extends laterally along the connector portion 124 and the other end extends upward parallel to the inner surface of the main body 410.

[0090] Next, the stator 64 is inserted into the main body 410 (Figure 10(B)). Multiple terminals 69 of the coil 68 (functioning as "first terminals") extend from one side of the stator 64. Each terminal 69 is L-shaped, aligned side by side, and its tip is pointed upward. Below the mounting hole 414 on the inner surface of the case 76, a recessed housing portion 418 is provided, divided to correspond to each terminal 69. The recessed housing portion 418 has alternating vertically extending protrusions and grooves side by side, and these multiple grooves serve as housings for each terminal 69.

[0091] By providing such a concave housing portion 418, it becomes possible to easily position the stator 64 relative to the case 76, that is, to position the mounting angle of the stator 64 around its axis, while ensuring insulation of adjacent terminals 69.

[0092] Next, the retaining member 430 is inserted into the main body 410 of the case 76 (Figure 10(C)). The retaining member 430 is a plate-like body that is roughly complementary in shape to the main body 410 in plan view, and has a rectangular base portion 432 fixed to the main body 410 in plan view, and a pressing portion 434 provided so as to protrude from one side of the base portion 432. Since the retaining member 430 is obtained by injection molding of resin material, the base portion 432 and the pressing portion 434 are integrally molded. An insertion hole 436 for inserting the can 66 in the axial direction is provided in the center of the base portion 432. An insertion hole 438 for inserting the terminal 69 of the stator 64 is provided between the base portion 432 and the pressing portion 434.

[0093] Furthermore, a circular hole is provided in the base portion 432 at a position corresponding to the upper surface of the stator 64, and an embossed support portion 440 is provided surrounding the circular hole. The support portion 440 protrudes upward from the upper surface of the base portion 432. When the base portion 432 is fixed to the case 76 by screws or the like, the retaining member 430 presses down on the stator 64 from above and supports the terminal element 420 by pressing it from the rear (Figure 12(A)).

[0094] Next, the coil spring 442, which acts as a conductive member, is inserted into the support part 440, and then the circuit board 118 is assembled to the case 76 (Figure 12(A)). The circuit board 118 is provided with through holes 444 at positions corresponding to each of the connection terminals 122 and terminals 69. As the circuit board 118 is assembled to the case 76, each terminal is inserted into its respective through hole 444 and fixed in place, thereby electrically connecting each terminal to the circuit of the circuit board 118.

[0095] On the other hand, one end of the coil spring 442 contacts the ground line of the circuit board 118, and the other end contacts the upper surface of the stator 64, thereby making it possible to connect the ground line and the stator 64 electrically and to ground the device. This reduces electromagnetic interference between the electric valve 301 and surrounding electronic equipment.

[0096] Then, the lid 77 is assembled to the case 76 (Figure 12(B)) and fixed by laser welding or the like to obtain the stator unit 492 (Figure 12(C)).

[0097] Figures 13 to 16 are diagrams that illustrate the function of the retaining member 430 in detail. Figure 13 shows the effect on the terminal element 420 when the retaining member 430 is attached to the case 76 (not shown). The terminal element 420 is constructed by assembling a plurality of connection terminals 122 (power terminal, ground terminal, communication terminal) onto a resin element body 422. The element body 422 is provided with a plurality of mounting holes (lateral holes) for each connection terminal 122, and each connection terminal 122 is fixed to the element body 422 by press-fitting it into its mounting hole.

[0098] In this embodiment, the number of mounting holes provided in the element body 422 is greater than the number of connection terminals 122 to which it is assembled (one more in the illustrated example). Therefore, it offers high versatility, such as being able to use the remaining mounting holes if additional connection terminals are to be added depending on the specifications of the electric valve (circuit).

[0099] Each connection terminal 122 is formed into an L-shape by bending a straight terminal after fixing it to the element body 422. In a modified example, the connection terminal 122 may be pre-formed into an L-shape and then press-fitted into the element body 422. In other modified examples, similar to the first embodiment, the L-shaped connection terminal 122 may be integrally formed with the element body 422 by resin molding (insert molding).

[0100] The element body 422 includes an insertion portion 424 that is inserted into the mounting hole 414 of the connector portion 124, and a locking portion 416 that engages with the inner surface of the case 76 (body 410) (see Figure 9). The insertion portion 424 has a cross-section complementary to the cross-section of the mounting hole 414. The locking portion 416 extends in the width direction and upward behind the insertion portion 424, and has engaging portions 426 that protrude rearward at both ends in the width direction. A space is formed between this pair of engaging portions 426 for the rear half (upwardly extending portion) of the connection terminal 122 to be positioned.

[0101] Each engaging portion 426 has a pressure-receiving portion 428 protruding along the outer edge of its rear surface 426a. The pressure-receiving portion 428 is a minute projection (ridge) extending in the vertical direction, and a tapered surface 429 is provided at its upper end. The tapered surface 429 is located below the upper surface of the engaging portion 426.

[0102] On the other hand, as described above, the retaining member 430 has a pressing portion 434 at its front end. When the retaining member 430 is lowered to assemble it to the case 76, the front surface 434a of the pressing portion 434 (more precisely, both ends of the front surface 434a) engages with the rear surface 426a of the engaging portion 426. At this time, the pressing portion 434 slides downward along the tapered surface 429 and rides up onto the top of the pressure receiving portion 428, thereby pressing the terminal element 420 forward. In other words, the retaining member 430 applies a forward pressing force to the terminal element 420, locking the displacement of the terminal element 420 in the insertion and removal direction from the mounting hole 414. As a result, the terminal element 420 can be firmly fixed to the connector portion 124.

[0103] Figure 14 shows the terminal element 420 and the retaining member 430 attached to the case 76. Figure 14(A) is a plan view, and Figure 14(B) is a cross-sectional view taken along the arrow DD in Figure 14(A). Figure 14(C) is a cross-sectional view taken along the arrow EE in Figure 14(A). As shown in Figures 14(A) and (B), the terminal element 420 is inserted into the mounting hole 414, the stator 64 is inserted into the case 76, and then the retaining member 430 is inserted into the case 76 and fixed in place. As a result, the pressing portion 434 of the retaining member 430 presses the engaging portion 426 of the terminal element 420 forward.

[0104] More specifically, as shown in Figure 14(C), the pressing portion 434 presses the pressure-receiving portion 428 of the terminal element 420 at both ends in the width direction. At this time, since the pressure-receiving portion 428 has a thin rib structure that is more easily deformed than the pressing portion 434, the pressure-receiving portion 428 deforms due to the pressing force of the pressing portion 434. As a result, the locking portion 416 of the terminal element 420 is firmly pressed against the inner surface 76a of the case 76. The terminal element 420 is stably supported in such a manner that it is sandwiched between the inner surface 76a of the case 76 and the front surface 434a of the retaining member 430.

[0105] Figure 15 shows the support structure of the stator 64 in the retaining member 430. Figure 16(A) is a cross-sectional view taken along the FF arrow in Figure 14(B), and Figure 16(B) is a cross-sectional view taken along the GG arrow in Figure 16(A). Figure 16(C) is an enlarged view of section H in Figure 16(B). As shown in Figure 15, the lower surface of the retaining member 430 is provided with a plurality of locking pieces 450 (locking parts) surrounding the insertion hole 436.

[0106] In this embodiment, six locking pieces 450 are arranged along the opening end of the insertion hole 436 at a total of six locations, spaced 60 degrees apart from the central axis of the insertion hole 436. The locking pieces 450 have a two-tiered stepped structure that protrudes downward from the retaining member 430. It goes without saying that the number, number of tiers, shape, etc., of these locking pieces 450 are illustrative examples and can be changed as appropriate.

[0107] As shown in Figures 16(A) and (B), the upper inner circumference of the yoke 72 in the stator 64 is provided with a plurality of recessed fitting portions 452 (fitting portions) obtained by partial notches. The recessed fitting portions 452 are open radially inward of the yoke 72 and have a larger opening width than the locking piece 450. In this embodiment, a total of 12 recessed fitting portions 452 are arranged at 30-degree intervals around the central axis of the annular yoke 72.

[0108] When the retaining member 430 is assembled to the case 76, each locking piece 450 fits into one of the concave fitting portions 452. In this embodiment, as shown in the figure, each locking piece 450 fits into every other of the annularly arranged concave fitting portions 452 (Figure 16(A)). The diameter of the circumscribed circles of the multiple concave fitting portions 452 is approximately equal to the diameter of the circumscribed circles of the multiple locking pieces 450. Therefore, the stator 64 and the retaining member 430 are positioned with high precision in such a manner that the outer circumferential surface 450a of each locking piece 450 abuts against the inner circumferential surface 452a of each concave fitting portion 452 (Figure 16(C)). In other words, the stator 64 and the retaining member 430 can be centered. The retaining member 430 is fixed to the case 76 by crimping and crushing the boss 76a (see Figure 16(B)) of the case 76, which is inserted through a fitting hole (not shown) in the retaining member 430. At this time, the lower surface of the retaining member 430 presses against the upper surface of the stator 64, firmly fixing the stator 64 to the case 76.

[0109] As shown in Figure 16(C), the inner diameter of the base portion 432 of the retaining member 430 is slightly smaller than the inner diameter of the stator 64 (i.e., the inner diameter of the yoke 72) in the portion through which the can 66 is inserted. Therefore, the inner circumferential surface of the stator 64 does not come into contact with the can 66. This allows the clearance between the can 66 and the stator 64 to be kept constant, thereby stabilizing the motor's torque.

[0110] In this embodiment as well, the guide member 6 and the valve seat member 8 are directly connected. Furthermore, only the valve housing 7 is interposed between the guide member 6, which is coaxial with the rotor 60, and the can 66, which is coaxial with the stator 64. In addition, a part of the valve seat member 8 (flange portion 130) is supported between the guide member 6 and the valve housing 7 in an axially sandwiched state. Therefore, the same effects as in the first embodiment can be obtained.

[0111] Furthermore, similar to the first embodiment, the stator 64 and terminal element 420 are made independent and connected via the circuit board 118. A case 76 is molded separately from the stator 64 and terminal element 420 (e.g., by injection molding of resin material), and the stator 64, terminal element 420, and circuit board 118 are assembled to the case 76.

[0112] Therefore, compared to the conventional manufacturing method in which the terminals 69 of the stator 64 and the connection terminals 122 of the connector part 124 are integrated with the case 76 by insert molding, the cycle time required for manufacturing the stator unit 492 can be shortened, which is convenient when mass-producing the electric valve 301. Those skilled in the art are aware that insert molding is unsuitable for relatively large parts such as the case of the stator unit (it is fine for small-scale production, but not suitable for mass production). In this regard, this embodiment can solve the problem of providing a manufacturing method that shortens the cycle time of such electric valves and is suitable for mass production.

[0113] This kind of technological philosophy can be expressed, for example, as follows: (Note 1) A body with a valve seat, A valve body that attaches to and detaches from the valve seat to open and close the valve section, A rotor for driving the valve body in the opening and closing direction of the valve portion, A cylindrical member enclosing the rotor, comprising a can that defines an internal space where fluid pressure acts and an external space where it does not, A stator unit is constructed by housing a stator, which is coaxially fitted onto the can, and a terminal element having connection terminals, in a resin case, wherein the case includes a connector portion that exposes the connection terminals inward, Equipped with, An electric valve characterized in that the terminal element is attached to a mounting hole provided in the connector portion.

[0114] (Note 2) The stator unit is configured by housing the stator, a circuit board to which a first terminal connected to the coil of the stator is connected, and a terminal element having a second terminal as a connection terminal connected to the circuit board, in the case. The electric valve according to Appendix 1, characterized in that the first terminal and the second terminal are connected via the circuit board.

[0115] (Note 3) The electric valve according to Appendix 1 or 2, further comprising a retaining member disposed within the case, fitted onto the can and fixed to the case, and supporting the terminal element and the stator while applying pressing force to prevent them from detaching from the case.

[0116] (Note 4) The electric valve according to Appendix 3, characterized in that the retaining member presses the stator in a first direction which is its axial direction, and presses the terminal element in a second direction which is perpendicular to the first direction.

[0117] (Note 5) The pressing member includes a base portion that presses the stator in the first direction and a pressing portion that presses the terminal element in the second direction. The electric valve according to Appendix 4, characterized in that the base portion and the pressing portion are integrally molded.

[0118] (Note 6) The terminal element has a pressure-receiving portion that protrudes toward the surface facing the pressing portion, The electric valve according to Appendix 5, characterized in that as the retaining member slides in the first direction relative to the terminal element, the pressing portion applies a pressing force in the second direction to the pressure receiving portion.

[0119] (Note 7) The pressure receiving section is In the terminal element, extending in the first direction, The electric valve according to Appendix 6, characterized in that the retaining member has a tapered surface at one end in the first direction that receives the pressing portion when the retaining member slides in the first direction and guides it to the top of the pressure receiving portion.

[0120] (Note 8) The retaining member has a locking portion protruding from the surface facing the stator, The stator has a fitting portion on the surface facing the retaining member, The electric valve according to Appendix 4, characterized in that the stator and the retaining member are positioned by the locking portion fitting into the fitting portion. In the third embodiment described above, a structure was adopted in which multiple locking pieces 450 (locking parts) are fitted into multiple concave fitting parts 452 (fitting parts), as shown in Figure 16. However, a different structure may be adopted. For example, a cylindrical projection (locking part) may be provided on the lower surface of the retaining member 430 and fitted into the inner circumferential surface (fitting part) of the stator 64.

[0121] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these specific embodiments, and various modifications are possible within the scope of the technical concept of the present invention.

[0122] [Differentiation] (Variation 1) Figure 17 is a cross-sectional view showing the structure of an electric valve according to a modified example. The modified electric valve 401 differs from the third embodiment in that it has a Hall IC 480 (Hall element) and its mounting structure for detecting the rotational speed of the rotor 60. The differences from the third embodiment will be explained below.

[0123] The electric valve 401 is constructed by assembling a valve unit 402 and a passage body 260. The valve unit 402 includes a rotor unit 490 and a stator unit 493. The stator unit 493 supports the stator 64 by pressing it from above with a retaining member 470, and also supports the terminal element 420 by pressing it from the rear. The Hall IC 480 is positioned opposite the rotor magnet 104 across a can 66.

[0124] Figure 18 shows the mounting structure of the Hall IC 480. Figure 18(A) is a side view of the circuit board 118, and Figure 18(B) is a perspective view of the circuit board 118 from the back side. Figure 18(C) is a perspective view showing the structure of the retaining member 470. As shown in Figures 18(A) and (B), the three terminals 482 of the Hall IC 480 are connected to the circuit board 118. This suspends the Hall IC 480 below the circuit board 118.

[0125] As shown in Figure 18(C), the retaining member 470 is provided with a boss-shaped sensor housing portion 484 adjacent to the outside of the insertion hole 436. The Hall IC 480 is housed in the sensor housing portion 484 and stably supported (see Figure 17). Because the sensor housing portion 484 opens toward the inside of the insertion hole 436, the Hall IC 480 can be positioned close to the rotor magnet 104, making it easier to maintain the sensitivity of the Hall IC 480.

[0126] Figure 19 is a diagram illustrating the assembly method of the stator unit 493. Figures 19(A) and (B) show a part of the assembly process. The assembly method of the stator unit 493 is substantially the same as that of the third embodiment shown in Figures 11 and 12. The retaining member 470 is inserted into the main body 410 of the case 76 (Figure 19(A)), and after attaching the coil spring 442 (conductive member), the circuit board 118 is assembled to the case 76 while inserting the Hall IC 480 into the sensor housing 484 (Figure 19(B)).

[0127] According to this modified example, the same effects as in the third embodiment can be obtained, and the 480 can be stably assembled using the retaining member 470.

[0128] (Modification 2) In the above embodiment, as shown in Figure 3, the valve housing 7 is offset axially from the press-fit portion 134 into which the guide member 6 is press-fitted and the male thread 10 for fastening to the passage body 200. This prevents or suppresses radial expansion of the valve housing 7 at the threaded portion (the screwed portion between the male thread 10 and the female thread 218) during the press-fitting process of the guide member 6. In particular, if the valve housing 7 is a press-formed product as in the first embodiment, it is prone to deformation due to press-fitting, but this prevents deformation of the threaded portion and avoids problems in subsequent assembly processes. In other words, in an electric valve in which a threaded member is press-fitted into the valve housing, the problem of maintaining good assembly efficiency of the valve body to the piping body can be solved.

[0129] This kind of technological philosophy can be expressed, for example, as follows: A valve body with a valve seat, A valve body that attaches to and detaches from the valve seat to open and close the valve section, An operating rod is axially connected to the valve body and is rotationally driven by a rotor, A screw feed mechanism includes a screw member through which the operating rod is inserted coaxially, and which converts the rotational motion of the rotor into axial motion of the operating rod, A cylindrical member enclosing the rotor, comprising a can that defines an internal space where fluid pressure acts and an external space where it does not, A passage body having a fluid passage and a mounting hole that communicates with the fluid passage and to which the valve body is attached, Equipped with, The valve body is A valve seat member is provided with the valve seat and is assembled coaxially with the screw member, A valve housing is welded coaxially with the can and houses the threaded member, Includes, The inner circumferential surface of the mounting hole is provided with female threads, while the outer circumferential surface of the valve housing is provided with male threads. By screwing the male thread into the female thread, the valve body is fastened to the passage body. The screw member has a press-fit portion that is press-fitted when inserted into the valve housing, An electric valve characterized in that the positions of the threaded portion between the male screw and the female screw and the position of the press-fit portion are offset in the axial direction.

[0130] [Other variations] In the above embodiment, an example was shown in which the retaining member is made of resin, but it may also be made of metal. In that case, the retaining member can also be used as a ground.

[0131] In the above embodiment, the orientation of the connector portion 124 (the orientation in which the connection terminal 122 extends toward the external terminal) is set to the side (perpendicular to the axis of the rotor 60), but it may also be set to the upward or downward (parallel to the axis of the rotor 60). In that case as well, a configuration is adopted in which the terminal element 420 can be pressed from the rear by the retaining member 430.

[0132] In the above embodiment, as shown in Figure 1, the valve unit 100 is exemplified as a configuration in which a rotor unit 90 and a stator unit 92 are manufactured separately 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 constitute an electric valve.

[0133] In the above embodiment, a structure in which the rotor and the operating rod are directly assembled is illustrated. In a modified example, a reduction mechanism may be provided between the rotor and the operating rod to adjust the degree to which the rotational motion of the rotor is converted into the translational motion of the operating rod. In other words, the amount of axial displacement of the valve body with respect to the number of rotations of the rotor may be adjusted. The reduction mechanism may be a planetary gear mechanism.

[0134] In the above embodiment, the rotational motion of the rotor is converted into translational motion (axial motion) of the actuating rod by the operation of the screw feed mechanism. At this time, the rotor also moves in translation together with the actuating rod. In a modified example, the rotor may be configured to maintain its axial position while the actuating rod moves in translation (see, for example, U.S. Patent Application Publication No. 2018 / 0135903). Alternatively, a structure may be adopted in which the rotation of the rotor is transmitted to the actuating rod via gears (see, for example, Japanese Patent Application Publication No. 2024-008534).

[0135] In the above embodiment, the stator includes a yoke having pole teeth. In a modified example, a stator including a laminated core may also be used.

[0136] In the above embodiment, the stator unit 92 is a two-phase stepping motor, but it may also be configured as a three-phase stepping motor.

[0137] In the above embodiment, the electric valve was configured as an expansion valve, but it may also be configured as an on-off valve that does not have an expansion function.

[0138] The electric valve of the above embodiment is suitably applied to refrigeration cycles using HFO-1234yf or the like as a refrigerant, but it can also be applied to refrigeration cycles using refrigerants with high operating pressure, such as carbon dioxide. In that case, an external heat exchanger such as a gas cooler is placed in place of the condenser in the refrigeration cycle.

[0139] In the above embodiment, an example was shown in which the electric valve is applied to the refrigeration cycle of an automotive air conditioning system. However, it is applicable to air conditioning systems equipped with an electric expansion valve, not limited to vehicles. It may also be configured as an electric valve to control the flow of fluids other than refrigerants, such as hot water in a hot water supply system or hydraulic fluid (hydraulic oil) in a hydraulic control device.

[0140] It should be noted that the present invention is not limited to the embodiments and modifications described above, and the components can be modified and implemented without departing from the spirit of the invention. Various inventions may be formed by appropriately combining the multiple components disclosed in the embodiments and modifications described above. In addition, some components may be deleted from all the components shown in the embodiments and modifications described above. [Explanation of symbols]

[0141] 1 Electric valve, 5 Valve body, 6 Guide member, 7 Valve housing, 8 Valve seat member, 10 Male thread, 22 Valve hole, 24 Valve seat, 26 Inlet port, 28 Outlet port, 30 Valve chamber, 32 Actuating rod, 34 Valve body, 38 Male thread, 40 Female thread, 60 Rotor, 64 Stator, 66 Can, 68 Coil, 69 Terminal, 72 Yoke, 76 Case, 90 Rotor unit, 92 Stator unit, 100 Valve unit, 104 Rotor magnet, 109 Screw feed mechanism, 118 Circuit board, 119 Retaining member, 120 Terminal element, 122 Connection terminal, 124 Connector part, 128 Communication hole, 130 Flange part, 132 Flange part, 134 Press-fit part, 142 Connecting member, 144 Guide part, 146 Locking member, 200 Passage body, 201 Motorized valve, 202 Inlet port, 204 Outlet port, 210 Fluid passage, 216 Mounting hole, 218 Female thread, 260 Passage body, 270 Seal structure, 300 Valve unit, 301 Motorized valve, 302 Valve unit, 305 Valve body, 306 Guide member, 307 Valve housing, 308 Valve seat member, 310 Step section, 332 Actuating rod, 360 Rotor, 362 Rotating shaft, 364 Stator, 390 Rotor unit, 392 Stator unit, 401 Motorized valve, 402 Valve unit, 410 Main body, 412 Partition, 414 Mounting hole, 416 Locking part, 420 Terminal element, 422 Element body, 424 Insertion part, 426 Engaging part, 428 Pressure receiving part, 429 Tapered surface, 430 Pressing member, 432 Base part, 434 Pressing part, 436 Through hole, 444 Through hole, 450 Locking piece, 452 Recessed fitting part, 470 Pressing member, 484 Sensor housing part, 490 Rotor unit, 492 Stator unit, 493 Stator unit.

Claims

1. A valve body with a valve seat, A valve body that attaches to and detaches from the valve seat to open and close the valve section, An operating rod is axially connected to the valve body and is rotationally driven by a rotor, A screw feed mechanism includes a screw member through which the operating rod is inserted coaxially, and which converts the rotational motion of the rotor into axial motion of the operating rod, A cylindrical member enclosing the rotor, comprising a can that defines an internal space where fluid pressure acts and an external space where it does not, Equipped with, The valve body is A valve seat member is provided with the valve seat and is assembled coaxially with the screw member, A valve housing is welded coaxially with the can and houses the connection between the threaded member and the valve seat member, Includes, The electric valve is characterized in that the screw member is inserted into and fixed to the valve housing with a portion of the valve seat member sandwiched axially between it and the valve housing.

2. The outer circumferential surface of the valve seat member is provided with a protrusion that extends radially outward, The electric valve according to claim 1, characterized in that the valve housing and the threaded member support the valve seat member in the axial direction by clamping the protrusion in the axial direction.

3. The end of the threaded member is inserted into the inside of the valve housing. The electric valve according to claim 1 or 2, characterized in that the end of the valve seat member is inserted inside the threaded member.

4. The passage body further comprises an introduction port for introducing fluid, an outlet port for discharging fluid, a fluid passage connecting the introduction port and the outlet port, and a mounting hole communicating with the fluid passage and to which the valve body is attached. The inner circumferential surface of the mounting hole is provided with female threads, while the outer circumferential surface of the valve housing is provided with male threads. The electric valve according to claim 1, characterized in that the valve body is fastened to the passage body by screwing the male thread into the female thread.

5. The screw member has a press-fit portion that is press-fitted when inserted into the valve housing, The electric valve according to claim 4, characterized in that the positions of the threaded portion between the male screw and the female screw and the position of the press-fit portion are offset in the axial direction.

6. The electric valve according to claim 5, characterized in that the valve housing is a press-formed product made of a metal material, and has a locking portion at the end opposite to the connection portion with the can that protrudes toward the valve seat member and locks a part of the valve seat member in the axial direction.

7. The valve seat member is A cylindrical body having a valve chamber for housing the valve element, A valve hole provided on the axis of the main body opposite to the screw member, The valve seat provided at the opening end on the valve chamber side of the valve hole, An inlet port is provided on the side of the main body, which connects the introduction port and the valve chamber, An outlet port that connects the valve hole and the outlet port, The electric valve according to claim 4, characterized by having the following features.

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