JP2024071877A - Motor-operated valve - Google Patents

Abstract

[Problem] To reduce the manufacturing cost of a motor-operated valve. [Solution] A motor-operated valve 1 comprises a valve body 5 having a valve seat 24 midway through a fluid passage, a rotor 60 for driving a valve element 34 in the opening and closing directions of a valve portion, a screw feed mechanism 109 including a screw member for converting the rotational motion of the rotor 60 into translational motion, a can 66 which is welded to the valve body 5 and is a cylindrical member containing the rotor 60 and which defines an internal space where the pressure of the fluid acts and an external space where the pressure of the fluid does not act, and a stator 64 which is fitted onto the can 66. At least a portion of the valve body 5 which is welded to the can 66 is a press-formed product made of a metal material. [Selected Figure] Figure 2

Description

The present invention relates to motor-operated valves, and in particular to a cost-reducing structure for motor-operated valves.

Automotive air conditioning systems are generally configured with a compressor, condenser, expansion device, evaporator, etc., 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.

An electric valve is constructed by assembling a body containing a valve portion and a motor unit (see Patent Documents 1 and 2). The motor unit has a can that contains a rotor and defines an internal space where fluid pressure acts and an external space where it does not act. The can must be non-magnetic because it is interposed between the rotor and stator. In general, the can and body are fixed by welding to ensure airtightness, so they are often constructed from the same type of metal material (stainless steel).

JP 2022-93843 A JP 2020-67122 A

For these types of motor-operated valves, the body is generally obtained by cutting a stainless steel round bar. However, stainless steel is generally considered to be a difficult material to cut, as its high viscosity makes it difficult to achieve cutting precision and the chips tend to join together, making it necessary to remove them one after another. For this reason, when cutting out a body with a complex shape, not only is the yield low, but the processing time is long, resulting in high manufacturing costs.

One of the objectives of the present invention is to reduce the manufacturing costs of motor-operated valves.

An electric valve according to one embodiment of the present invention comprises a valve body in which a fluid passage is formed and which has a valve seat midway through the fluid passage, a valve element which opens and closes the valve section by approaching and separating from the valve seat, a rotor for driving the valve element in the opening and closing direction of the valve section, a screw feed mechanism which includes a screw member and converts the rotational motion of the rotor into translational motion, a can which is welded to the valve body and is a cylindrical member which contains the rotor and which defines an internal space in which the pressure of the fluid acts and an external space in which the pressure of the fluid does not act, and a stator which is fitted onto the can. At least a portion of the valve body which is welded to the can is a press-formed product of a metal material.

According to this embodiment, at least a portion of the valve body is obtained by press molding, and the press-molded product is welded to the can. Even if the press-molded product is made of the same type of difficult-to-cut material as the can, it does not take a long time to process. As a result, the manufacturing costs of the motor-operated valve can be reduced.

Another embodiment of the motor-operated valve of the present invention includes a body having a fluid passage and containing a valve portion, a valve element that opens and closes the valve portion, a rotor for driving the valve element in the direction of opening and closing the valve portion, a screw feed mechanism that includes a screw member and converts the rotational motion of the rotor into translational motion, a can that is fixed to the body and is a cylindrical member that contains the rotor and defines an internal space in which the pressure of the fluid acts and an external space in which the pressure of the fluid does not act, an intermediate member that is welded to the can and disposed between the can and the body, and a stator that is inserted onto the can. The intermediate member is a press-formed product of a metal material.

According to this embodiment, the can and the body are assembled via an intermediate part, and the intermediate part is welded to the can. Therefore, it is not necessary for the can and the body to be made of the same type of material. A material that is easier to cut than the can can be selected as the material for the body. Because the intermediate part is a press-formed product, even if the same type of difficult-to-cut material as the can is used as the material, it does not take a long time to process it. As a result, the manufacturing costs of the motor-operated valve can be reduced.

The present invention can reduce the manufacturing costs of motor-operated valves.

1 is a cross-sectional view showing a structure of a motor-operated valve according to a first embodiment. FIG. 2 is a cross-sectional view showing the structure of a valve unit. FIG. 4 is a cross-sectional view illustrating a configuration of a motor-operated valve according to a first modified example. FIG. 11 is a cross-sectional view showing a configuration of a motor-operated valve according to a second modified example. FIG. 11 is a cross-sectional view showing a configuration of a motor-operated valve according to a third modified example. FIG. 11 is a cross-sectional view showing a configuration of a motor-operated valve according to a fourth modified example. FIG. 6 is a cross-sectional view illustrating a configuration of a motor-operated valve according to a second embodiment. FIG. 8 is an enlarged view of part A in FIG. 7 . FIG. 13 is a cross-sectional view showing a configuration of a motor-operated valve according to a fifth modified example.

The following describes in detail an embodiment of the present invention 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 embodiments and their modified examples, substantially identical components are given the same reference numerals, and their description will be omitted as appropriate.

[First embodiment]
FIG. 1 is a cross-sectional view showing the structure of a motor-operated valve according to a first embodiment.
The motor-operated valve 1 is applied to a refrigeration cycle of an air conditioner for an automobile (not shown). This refrigeration cycle includes a compressor that compresses a 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. The motor-operated valve 1 functions as the expansion valve.

The motor-operated 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. 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 that is fixed to the stator unit 92 and a screw for fixing the metal plate to the passage body 200.

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

The passage body 200 is formed with a first passage 210 connecting the inlet port 202 and the outlet port 204, and a second passage 212 connecting the inlet port 206 and the outlet port 208. The first passage 210 and the second passage 212 function as "fluid passages". The first passage 210 and the second passage 212 are separated vertically by a partition wall 214. A mounting hole 216 opens upward at the top of the passage body 200. The mounting hole 216 communicates with the first passage 210. A female thread portion 218 is formed near the open end of the mounting hole 216.

The valve unit 100 has a valve body 5 that contains a valve portion. A valve seat member 8 is provided at the lower end of the valve body 5, and a seal ring 20 (O-ring) is attached to the outer peripheral surface of the valve seat member 8. A male thread portion 10 that can be screwed into a female thread portion 218 is formed on the outer peripheral surface of the valve body 5. When assembling the valve unit 100 to the passage body 200, the valve body 5 is inserted into the mounting hole 216. The male thread portion 10 is screwed into the female thread portion 218, and the valve body 5 is fastened to the passage body 200.

The upper surface of the passage body 200 is provided with an annular seal receiving portion 222 (annular groove) surrounding the mounting hole 216, and a seal ring 220 (O-ring) is fitted into the annular groove. The upper surface of the passage body 200 is also provided with an annular step 224 surrounding the seal receiving portion 222, and an annular packing 226 is disposed inside the step 224. 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 packing 226 is interposed between the upper surface of the passage body 200 and the stator unit 92.

The seal ring 220 prevents refrigerant from leaking from the inside of the passage body 200 to the outside. The packing 226 prevents moisture and other contaminants from entering the inside of the valve unit 100 from the outside atmosphere. The seal ring 20 seals between the upstream passage 230 and downstream passage 232 of the valve section.

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

The rotor unit 90 has a valve body 5. The valve body 5 includes a valve housing 6 and a valve seat member 8. The valve housing 6 has a large diameter portion 7 and a small diameter portion 9 integrally formed therewith, and is a stepped cylinder whose outer diameter decreases downward. The upper portion of the small diameter portion 9 is slightly enlarged in diameter, and a male thread portion 10 is formed on its outer circumferential surface. An inlet port 26 is provided on the lower side of the small diameter portion 9.

The valve housing 6 is a press-formed product made of stainless steel (hereinafter referred to as "SUS"), and the male thread 10 is formed by cutting after pressing the material. The inlet port 26 is also formed by pressing. In a modified example, the male thread 10 may be processed by rolling or other methods. The inlet port 26 may also be formed by cutting. As shown in FIG. 1, the small diameter portion 9 is screwed into the mounting hole 216, causing the large diameter portion 7 to abut against the passage body 200 in the axial direction, thereby restricting the amount of insertion of the valve body 5 into the mounting hole 216.

A valve seat member 8 is coaxially assembled to the lower end opening of the valve housing 6. The valve seat member 8 is a stepped cylinder, and a seal receiving portion 18 consisting of an annular groove is formed on the outer peripheral surface of the lower portion of the valve seat member 8, into which a seal ring 20 is fitted. The upper portion of the valve seat member 8 is press-fitted into the lower end of the valve housing 6, thereby fixing the valve seat member 8 to the valve body 5. To increase the fixing force, the lower end opening of the valve housing 6 may be crimped inward.

The inner diameter of the upper part of the valve seat member 8 is reduced to form a valve hole 22, and a valve seat 24 is formed at the upper end opening of the valve hole 22. In this embodiment, the valve seat member 8 is made of SUS, but a material with excellent wear resistance such as brass may be selected. In other words, the valve housing 6 may be made of a material that is more weldable than the valve seat member 8, and the valve seat member 8 may be made of a material that is more machineable than the valve body 5.

An outlet port 28 is provided at the bottom of the valve seat member 8. The inlet port 26 communicates with an introduction port 202, and the outlet port 28 communicates with a discharge port 204 (see FIG. 1). An internal passage that communicates the inlet port 26 and the outlet port 28 is formed inside the valve body 5. A valve chamber 30 is formed inside the valve housing 6. The inlet port 26 and the outlet port 28 communicate via the valve chamber 30.

The actuating rod 32 extending from the rotor 60 of the rotor unit 90 is inserted into the inside of the valve body 5. The actuating rod 32 passes through the valve chamber 30. The actuating rod 32 is obtained by cutting a rod material made of a non-magnetic metal, and a needle-shaped valve body 34 is integrally provided at the bottom. The valve body 34 is attached to and detached from the valve seat 24 from the valve chamber 30 side to open and close the valve section.

A guide member 36 is erected inside the large diameter portion 7 of the valve housing 6 via a connecting member 12. The connecting member 12 has a cylindrical shape that is simpler than the valve housing 6 (shape with smaller change in inner and outer diameter), and is made of brass in this embodiment. The connecting member 12 is obtained by cutting a tubular material, and has a flange portion 14 that protrudes radially inward at its lower end, and a flange portion 16 that protrudes radially outward at its upper end.

The connecting member 12 is press-fitted coaxially into the large diameter portion 7 of the valve housing 6 and fixed thereto. The lower surface of the flange portion 16 engages with the upper surface of the large diameter portion 7, thereby restricting the amount of insertion of the connecting member 12 into the large diameter portion 7.

The guide member 36 is obtained by cutting a tube made of a non-magnetic metal (brass in this embodiment) into a stepped cylindrical shape, and a male thread 38 is formed on the outer circumferential surface of the central portion in the axial direction. The guide member 36 functions as a "screw member." The lower end of the guide member 36 has a large diameter, and the large diameter portion 40 is press-fitted into the connecting member 12 and fixed. The flange portion 14 engages the bottom of the large diameter portion 40, thereby regulating the amount of press-fitting. To increase the fixing force, the upper end opening of the connecting member 12 may be crimped inward.

The guide member 36 supports the operating rod 32 axially slidably on its inner circumferential surface, while supporting the rotating shaft 62 of the rotor 60 rotatably and slidably on its outer circumferential surface. The rotating shaft 62 is made of a non-magnetic metal.

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

The can 66 is made of a non-magnetic metal (e.g., SUS), its lower end is fitted onto the flange portion 16 of the connecting member 12, and its lower end face abuts against the upper end face of the valve housing 6. The valve body 5 and the can 66 are fixed together by welding (full-circumference welding) along the boundary between the can 66 and the valve housing 6 (not shown), ensuring airtightness (seal) between them. The space surrounded by the valve body 5 and the can 66 forms the above-mentioned pressure space.

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 enclosed in a case 76. 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 by the injection molding. The case 76 is made of the molded resin. The stator unit 92 is an integrated part of the stator 64 and the case 76 (a molded product in this embodiment). The stator unit 92 has a hollow structure, and the stator 64 is assembled to the rotor unit 90 while coaxially inserting the can 66. The welded portion between the can 66 and the valve body 5 is located inside the case 76.

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

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

The upper part of the actuation rod 32 is reduced in diameter, and the reduced diameter portion 110 penetrates the bottom 112 of the rotating shaft 62. An annular stopper 114 is fixed to the tip of the reduced diameter portion 110. Meanwhile, a spring 116 that biases the actuation rod 32 downward (i.e., in the valve closing direction) is interposed between the base end of the reduced diameter portion 110 and the bottom 112. With this configuration, when the valve is opened, the actuation rod 32 is displaced integrally with the rotor 60 with the stopper 114 engaged with the bottom 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.

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 a control unit and a communication unit 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 an external device, a power supply circuit for supplying power to each circuit and the motor (coil), etc. are mounted. The upper end of the case 76 is closed by a resin lid 77. The circuit board 118 is disposed in the space below the lid 77 of the case 76.

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 capturing this change in magnetic flux. The control unit calculates the axial position of the valve body 34 and thus the valve opening degree based on the amount of displacement of the rotor 60.

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

Returning to FIG. 1, when assembling the motor-operated valve 1, the passage body 200, the rotor unit 90, and the stator unit 92 are each manufactured separately. Then, the rotor unit 90 and the stator unit 92 are each fixed to the passage body 200.

First, the seal ring 220 is fitted into the seal housing portion 222 of the passage body 200. The seal ring 20 is fitted into the rotor unit 90. Next, the rotor unit 90 is inserted into the mounting hole 216 from the tip side of the valve body 5. At this time, the male thread portion 10 is screwed into the female thread portion 218, and the rotor unit 90 is assembled to the passage body 200 while being rotated.

By fastening the rotor unit 90 to the passage body 200, the seal ring 220 is appropriately crushed, and the sealing function is effectively exerted. The sealing function of the seal ring 20 is also effectively exerted. Then, the stator unit 92 is assembled to the rotor unit 90 while being coaxially inserted into the can 66. Prior to this assembly, the metal plate of the connection member 101 is fixed to the case 76 of the stator unit 92 by welding or the like.

The stator unit 92 is fixed to the passage body 200 by fastening the metal plate to the passage body 200 with screws (not shown). As a result, the rotor unit 90 and the stator unit 92 are also indirectly fixed.

The motor-operated valve 1 configured as described above functions as an electric expansion valve whose valve opening can be adjusted by controlling the drive of the rotor unit 90. That is, based on a command from an external device (not shown), the control unit sets the control amount (the number of drive steps of the motor) for achieving the target opening, and outputs a drive signal for achieving this to the drive circuit. The drive circuit supplies 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 together with the rotor 60.

The rotor 60 moves up and down by a screw feed mechanism 109 between the rotor 60 and the guide member 36. The valve body 34 translates in the opening and closing direction of the valve section, and the opening of the valve section is adjusted to the set opening. The screw feed mechanism 109 converts the rotational motion of the rotor 60 around the axis into axial motion (linear motion) of the operating rod 32, and drives the valve body 34 in the opening and closing direction of the valve section. When the motor-operated valve 1 functions as an expansion valve, the valve section is controlled to a small opening. The control unit detects the rotational angle of the sensor magnet 106 (the rotational angle of the rotor 60) based on the detection signal of the magnetic sensor 119, and can calculate the valve opening.

As described above, in this embodiment, the valve housing 6, which is a part of the valve body 5, is obtained by press molding, so there is less waste of material compared to machined products. Even if the valve housing 6 is made of the same type of difficult-to-cut material (e.g., SUS) as the can 66, it does not take a long time to machine it. On the other hand, an aluminum alloy (a material that can be cut with high precision in a relatively short time) that has better machinability than the valve housing 6 is used as the material for the passage body 200, which has a larger volume. According to this embodiment, the amount of cutting of the difficult-to-cut material can be kept small. As a result, the manufacturing cost of the motor-operated valve 1 can be reduced.

[Modification]
FIG. 3 is a cross-sectional view showing the configuration of the motor-operated valve according to the first modification.
The motor-operated valve of this modification differs from the first embodiment in the structure of the valve body and its surroundings. The valve unit 150 includes a rotor unit 190 and a stator unit 92. The rotor unit 190 has a valve body 155 that is assembled coaxially with the can 66. The valve body 155 has a valve housing 156 and a valve seat member 158. The valve housing 156 is made of the same type of metal as the can 66 (SUS in this modification). The valve seat member 158 is made of SUS in this modification, but may be made of brass.

The valve housing 156 has a large diameter portion 157 and a small diameter portion 159, and is a stepped cylinder whose outer diameter decreases downward. The valve housing 156 is obtained by press molding. The upper end of the large diameter portion 157 is inserted into the lower end of the can 66. A step is provided along the periphery of the upper end surface of the large diameter portion 157, and the lower end of the can 66 fits into this step, ensuring concentricity between the can 66 and the valve housing 156. The can 66 and the valve housing 156 are fixed by full-circumference welding along the joint between the two. A male thread portion 10 is formed on the outer circumferential surface of the small diameter portion 159.

The valve seat member 158 is cylindrical with a bottom and is obtained by cutting a tubular material. A valve hole 22 is formed so as to pass through the bottom of the valve seat member 158 along the axis. A seal accommodating portion 18 is formed on the outer peripheral surface of the lower end of the valve seat member 158, and a seal ring 20 is fitted into it. The upper portion of the valve seat member 158 is fixed to the lower portion of the guide member 136 (screw member) by press fitting. To increase the fixing force, the upper end opening of the valve seat member 158 may be crimped inward. An inlet port 26 is provided on the lower side of the valve seat member 158.

In this modified example, a part of the valve body 155, i.e., the valve housing 156, is a press-formed product, so the same effects as in the above embodiment can be obtained. In this embodiment, the valve seat member 158 is obtained by cutting, but it may also be obtained by press forming.

In another modification, the valve seat member 158 of the first modification may be divided into an upper and lower cylindrical member and a valve seat member. The cylindrical member may be a press-molded product. Specifically, the valve housing 156 may be the first valve body, the cylindrical member may be the second valve body, and the two may be coaxially fixed by press-fitting or the like to form a "valve body." In this case, an inlet port 26 is provided on the lower side of the cylindrical member, and the upper end of the cylindrical member is fixed to the guide member 136. Then, as in the above embodiment, the valve seat member 8 may be press-fitted and fixed into the lower end opening of the cylindrical member. In order to increase the fixing force, the lower end opening of the cylindrical member may be crimped inward.

FIG. 4 is a cross-sectional view showing the configuration of a motor-operated valve according to the second modification.
The motor-operated valve of this modification differs from that of the first embodiment in the assembly structure between the valve body and the guide member. The valve unit 160 includes a rotor unit 192 and a stator unit 92. The can 66 and the valve housing 6 are fixed coaxially by full-circumference welding to ensure sealing performance.

The guide member 166 (threaded member) of the rotor unit 192 is axially larger than the guide member 36 of the first embodiment. The large diameter portion 40 of the guide member 166 is coaxially press-fitted into the small diameter portion 9 of the valve housing 6.

In this modified example, the valve housing 6 is a press-molded product, so the same effects as in the above embodiment can be obtained. The guide member 166 is fixed directly to the valve housing 6, so there is no need for the connecting member 12 of the above embodiment. This allows the number of parts to be reduced.

FIG. 5 is a cross-sectional view showing the configuration of a motor-operated valve according to the third modification.
The motor-operated valve of this modification differs from Modification 2 in the assembly structure between the valve body and the guide member. The valve unit 170 includes a rotor unit 193 and a stator unit 92. A guide member 176 (threaded member) is integrated with the valve housing 6 by insert molding of a resin material. The large diameter portion 40 of the guide member 176 is integrated with the small diameter portion 9 of the valve housing 6.

This modified example can achieve the same effects as the above embodiment, and can also reduce the number of parts, as in modified example 2.

FIG. 6 is a cross-sectional view showing the configuration of a motor-operated valve according to the fourth modification.
The motor-operated valve of this modification is configured by assembling a motor unit 182 and a body 280 via an intermediate member 185. The motor unit 182 has a configuration substantially similar to the valve unit 160 of the second modification (see FIG. 4 ) except that it does not have a valve body and a valve seat member. The body 280 has a configuration substantially similar to the passage body 200 of the first embodiment (see FIG. 1 ). The valve hole 22 and the valve seat 24 are provided midway through the first passage 210 in the body 280.

The motor unit 182 includes a rotor unit 194 and a stator unit 92. The intermediate member 185 is made of the same metal as the can 66 (SUS in this modified example). The intermediate member 185 has a large diameter portion 7 and a small diameter portion 189 similar to the valve housing 6 of the first embodiment, but does not have an inlet port 26 and is small in the axial direction. A male thread portion 10 is formed on the outer peripheral surface of the small diameter portion 189, and the upper end of the large diameter portion 7 is assembled to the lower end of the can 66 and fixed by full-circumference welding.

The large diameter portion 40 of the guide member 186 (screw member) is press-fitted into the small diameter portion 189, and the guide member 186 and the intermediate member 185 are fixed coaxially. A flange portion 187 that protrudes radially inward is provided at the lower end of the small diameter portion 189, and the bottom of the guide member 186 is engaged by the flange portion 187. The operating rod 32 extends to the back of the mounting hole 216 and is attached to and detached from the valve seat 24 to open and close the valve portion.

In this modified example, the can 66 and the body 280 are assembled via the intermediate member 185, so there is no need to construct them from the same type of material. For this reason, a material that is easier to cut than the can 66 (such as an aluminum alloy) can be selected as the material for the body 280. On the other hand, because the intermediate member 185 is obtained by press molding, there is less waste of material compared to a machined product. Furthermore, even if the intermediate member 185 is made of the same type of difficult-to-cut material as the can 66, it does not take a long time to process it. As a result, the manufacturing costs of the motor-operated valve can be reduced.

[Second embodiment]
Fig. 7 is a cross-sectional view showing the configuration of the motor-operated valve according to the second embodiment, and Fig. 8 is an enlarged view of a portion A in Fig. 7 .
7, the motor-operated valve 201 is different from the first embodiment in that it includes a large-diameter first valve 250 and a small-diameter second valve 252, and these valves are driven to open and close by a shared motor unit 254. The motor-operated valve 201 functions as an on-off valve by opening and closing the first valve 250, and functions as an expansion valve by adjusting the opening degree of the second valve 252.

The motor-operated valve 201 is configured by assembling a motor unit 254 and a body 260 via an intermediate member 285. The motor unit 254 includes a rotor unit 290 and a stator unit 92. The rotor unit 290 differs from the first embodiment in the support structure of the valve body by the guide member 236 (screw member).

The intermediate member 285 is made of the same type of metal as the can 66 (SUS in this embodiment) and is a press-formed product. The intermediate member 285 has a stepped cylindrical shape with a large diameter portion 207 and a small diameter portion 209. The upper end of the large diameter portion 207 is inserted into the lower end of the can 66 and is fixed coaxially by full-circumference welding. The small diameter portion 209 is inserted into the mounting hole 216, and a seal ring 220 (O-ring) is interposed between the inner surface of the mounting hole 216 and the outer surface of the small diameter portion 209.

An annular valve seat forming member 262 is press-fitted into the middle of the fluid passage 211 in the body 260. A valve hole 264 (first valve hole) that is coaxial with the mounting hole 216 is formed inside the valve seat forming member 262. A valve seat 266 (first valve seat) is formed at the downstream opening of the valve hole 264.

The guide member 236 is a resin molded part obtained by injection molding of resin. The lower part of the guide member 236 is expanded in diameter and press-fitted into the lower part of the mounting hole 216. This fixes the guide member 236 to the body 260. The guide hole 268 is formed by the inner peripheral surface of the lower part of the guide member 236. The small diameter part 209 of the intermediate member 285 is inserted into the annular space formed between the inner peripheral surface of the mounting hole 216 and the outer peripheral surface of the guide member 236. A predetermined clearance is provided between the intermediate member 285 and the guide member 236.

As shown in FIG. 8, a valve body 270 (first valve body) is disposed inside the guide member 236. The valve body 270 is cylindrical with a bottom and slidably supported in the guide hole 268. The valve body 270 opens and closes the first valve 250 by attaching and detaching from the valve seat 266 from the downstream side. Meanwhile, a valve hole 22 (second valve hole) is formed in the middle of the internal passage of the valve body 270. A valve seat 24 (second valve seat) is formed at the upstream opening of the valve hole 22.

The valve body 270 is cylindrical with a bottom that has a sufficient thickness. A back pressure chamber 274 is formed above the valve body 270. The back pressure chamber 274 is a space surrounded by the guide member 236 and the valve body 270. A valve chamber 276 is formed inside the valve body 270 (above the bottom). A disk-shaped operating connection member 278 is fixed to the upper part of the valve body 270. The operating connection member 278 has an insertion hole 287 in its center. The operating rod 32 passes coaxially through the insertion hole 287. The insertion hole 287 connects the valve chamber 276 to the back pressure chamber 274.

A radially protruding locking portion 284 is provided on the actuation rod 32 slightly above the valve body 34. The locking portion 284 is, for example, an E-ring. A spring 282 (biasing member) is interposed between the guide member 236 and the bottom of the actuation connecting member 278. The biasing force of the spring 282 is transmitted to the valve body 270 via the actuation connecting member 278. In addition, when the valve body 34 is opened, the locking portion 284 is displaced relative to the valve body 270, and by abutting against and pushing up the bottom surface of the actuation connecting member 278, the valve body 270 can be actuated in the opening direction.

The valve body 270 has a plurality of communication holes 288 (small holes) that penetrate the bottom of the valve body 270 parallel to the axis. The lower end openings of these communication holes 288 serve as the inlet port 26. The communication holes 288 communicate the upstream side of the valve seat 266 in the valve hole 264 with the valve chamber 276. The communication holes 288, the valve chamber 276, and the insertion hole 287 form a "communication passage" that communicates the upstream side of the valve seat 266 with the back pressure chamber 274. In addition, the bottom of the valve body 270 has a communication hole 292 that extends perpendicular to the axis and communicates with the valve hole 22. The communication hole 292 has an outlet port 28 that opens toward the downstream passage 232. A seal ring 272 (O-ring) is fitted to the upper part of the valve body 270, and the flow of the refrigerant through the gap between the valve body 270 and the guide member 236 is regulated.

The motor-operated valve 201 configured as described above operates as follows. When the motor unit 254 opens the valve and operates the actuating rod 32 upward, the valve body 34 separates from the valve seat 24. This allows the communication hole 288, the valve chamber 276, the valve hole 22, and the communication hole 292 to communicate with each other. Refrigerant from the upstream side flows through the internal passage of the valve body 270 and is discharged to the downstream side via the second valve 252. At this time, the second valve 252 can be adjusted to a predetermined opening degree to function as an expansion valve.

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

When the motor unit 254 is operated to close the valve, the operating rod 32 is operated downward, in the opposite manner to the above. At this time, the valve body 270 operates in the valve closing direction while maintaining the operational connection with the operating rod 32 due to the biasing force of the spring 282. First, the valve body 270 seats on the valve seat 266, and the first valve 250 is in a closed state. When the operating rod 32 is further operated in the valve closing direction, the locking portion 284 disengages from the operational connection member 278, and the operational connection between the operating rod 32 and the valve body 270 is released. After that, the valve body 34 seats on the valve seat 24, and the second valve 252 is in a closed state.

In this embodiment, the intermediate member 285 is obtained by press molding, so the same effects as in the first embodiment (variation 4, etc.) can be obtained.

[Modification]
FIG. 9 is a cross-sectional view showing the configuration of a motor-operated valve according to the fifth modification.
The motor-operated valve of this modification differs from the second embodiment in the support structure of the guide member. The motor unit 255 has a support member 294 fixed to the intermediate member 285. The support member 294 is a press-formed product, and supports the guide member 237 (screw member) from below. The support member 294 has a stepped cylindrical shape having a large diameter portion 295 and a small diameter portion 296 at the top and bottom. The guide member 237 may be a machined product made of a metal material, or may be a resin-molded product.

The large diameter portion 295 is press-fitted into the large diameter portion 207 of the intermediate member 285 and firmly fixed by welding along the boundary. The large diameter portion 40 of the guide member 237 is press-fitted into the small diameter portion 296 of the support member 294 and fixed. A circular boss-shaped shielding wall 297 protrudes downward from the lower end opening of the small diameter portion 296. The shielding wall 297 prevents foreign matter from entering the can 66 from the valve chamber 276.

As in the second embodiment, the can 66 and the intermediate member 285 are fixed coaxially by full-circumference welding at the joint. In this modified example, the support member 294 and the can 66 are welded to the intermediate member 285, so these members are made of the same type of metal (e.g., SUS).

In this modified example, in addition to the intermediate member 285, the support member 294 is also obtained by press molding, and the same effects as in the first embodiment can be obtained.

The above describes a preferred embodiment of the present invention, but 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.

[Other Modifications]
In the above embodiment, the guide member (thread member) is provided coaxially with the valve body and slidably supports the actuation rod. Also, an example is shown in which a male screw is provided on the outer peripheral surface of the guide member inside the rotor, and a screw feed mechanism is formed together with a female screw provided on the inner peripheral surface of the rotor.

In a modified example, a female thread may be provided on the inner peripheral surface of a cylindrical screw member, while a male thread may be provided on the outer peripheral surface of the rotor's rotating shaft, and these threads may form a screw feed mechanism. Alternatively, the screw feed mechanism may be disposed on the outside of the rotor. In either configuration, at least a portion of the valve body that is welded to the can may be a press-formed product. Also, an intermediate part that is welded to the can may be a press-formed product. The screw member may be fixed to the valve body or the intermediate part.

In the above embodiment, a structure in which the rotor and the guide member (screw member) are directly screwed together by a screw feed mechanism is exemplified. In a modified example, the rotor may have a speed reduction mechanism, and the rotation of the rotor may be reduced and transmitted to the screw member and ultimately to the valve body. The speed reduction mechanism may be a planetary gear mechanism.

In the above embodiment, an aluminum alloy is used as the material for the passage body 200, but any material with a higher machinability index than the valve housing 6 may be used. The "machinability index" is an index that indicates the ease or difficulty of cutting a metal material, and specifically refers to a value that indicates the ease of cutting a material compared to sulfur free-cutting steel (AISI-B1112) (see, for example, JP 2005-335091 A). The higher the machinability index, the easier it is to cut. By using a material with a relatively high machinability index (i.e., a material with excellent machinability), machining accuracy can be maintained even if the cutting speed (tool feed speed) is increased. In other words, the total cutting time for large parts can be shortened, and machining costs can be reduced.

In the above embodiment, a configuration in which the rotor unit 90 and the stator unit 92 are indirectly fixed to each other by assembling them to the passage body 200 has been exemplified. In a modified example, the rotor unit may be directly fixed to the stator unit to form a valve unit, and the valve unit may be assembled to the passage body. The rotor unit and the stator unit may also be fixed via a connecting member. In that case, the valve unit may be considered as an "electric valve." The passage body may be the body or housing of the target device to which the electric valve is attached.

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

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

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.

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.

The motor-operated valve of the above embodiment is preferably applied to a refrigeration cycle that uses a refrigerant such as a fluorocarbon alternative (HFC-134a) as a refrigerant, but it 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 placed in the refrigeration cycle instead of a condenser.

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

The present invention is not limited to the above-described embodiment and modifications, and can be embodied by modifying the components without departing from the spirit of the invention. Various inventions may be formed by appropriately combining multiple components disclosed in the above-described embodiment and modifications. In addition, some components may be deleted from all the components shown in the above-described embodiment and modifications.

1 Motor-operated valve, 5 Valve body, 6 Valve housing, 7 Large diameter portion, 8 Valve seat member, 9 Small diameter portion, 10 Male thread portion, 12 Connecting member, 20 Seal ring, 22 Valve hole, 24 Valve seat, 26 Inlet port, 28 Outlet port, 30 Valve chamber, 32 Actuating rod, 34 Valve body, 36 Guide member, 38 Male thread, 60 Rotor, 62 Rotating shaft, 64 Stator, 66 Can, 68 Coil, 76 Case, 90 Rotor unit, 92 Stator unit, 100 Valve unit, 101 Connecting member, 104 Rotor magnet, 106 Sensor magnet, 108 Female thread, 109 Screw feed mechanism, 116 Spring, 119 Magnetic sensor, 124 Connector portion, 136 Guide member, 150 Valve unit, 155 Valve body, 156 Valve housing, 157 Large diameter portion, 158 Valve seat member, 159 Small diameter portion, 160 Valve unit, 166 Guide member, 170 Valve unit, 176 Guide member, 182 Motor unit, 185 Intermediate member, 186 Guide member, 187 Flange portion, 189 Small diameter portion, 190 Rotor unit, 192 Rotor unit, 193 Rotor unit, 194 Rotor unit, 200 Passage body, 201 Motor valve, 202 Inlet port, 204 Outlet port, 206 Inlet port, 207 Large diameter portion, 208 Outlet port, 209 Small diameter portion, 210 First passage, 210 Fluid passage, 212 Second passage, 216 Mounting hole, 218 Female thread portion, 230 Upstream passage, 232 Downstream passage, 236 Guide member, 237 Guide member, 250 First valve, 252 Second valve, 254 Motor unit, 260 Body, 262 valve seat forming member, 264 valve hole, 266 valve seat, 268 guide hole, 270 valve body, 274 back pressure chamber, 276 valve chamber, 278 operating connection member, 280 body, 282 spring, 284 locking portion, 285 intermediate member, 287 insertion hole, 288 communication hole, 290 rotor unit, 294 support member, 295 large diameter portion, 296 small diameter portion, 297 shielding wall.

Claims (9)

a valve body having a fluid passage formed therein and a valve seat located midway through the fluid passage;
a valve body that moves toward and away from the valve seat to open and close the valve portion;
a rotor for driving the valve body in a direction in which the valve portion is opened and closed;
a screw feed mechanism including a screw member and configured to convert a rotational motion of the rotor into a translational motion;
a can, which is a cylindrical member welded to the valve body and contains the rotor, and which defines an internal space on which the pressure of a fluid acts and an external space on which the pressure of a fluid does not act;
A stator that is inserted into the can;
Equipped with
2. An electrically operated valve, comprising: a valve body having a first end and a second end, the valve body being welded to the first end of the valve body; The valve body includes:
a valve housing fixed to the can;
a valve seat member fixed to the valve housing and provided with the valve seat;
Including,
2. The motor-operated valve according to claim 1, wherein the valve housing is a press-molded product. The valve housing is in the form of a stepped cylinder having a large diameter portion coaxially connected to the can and a small diameter portion inserted into a mounting hole of a passage body to which the valve housing is to be mounted,
3. The motor-operated valve according to claim 2, wherein an outer peripheral surface of the small diameter portion is provided with a male thread portion that can be screwed into a female thread portion provided on an inner peripheral surface of the mounting hole. The motor-operated valve according to claim 3, characterized in that the valve seat member passes through the small diameter portion and is fixed to the screw member. The motor-operated valve according to claim 2 or 3, characterized in that the screw member is integrated with the valve housing by insert molding of a resin material. a body having a fluid passage and containing a valve portion;
A valve body that opens and closes the valve portion;
a rotor for driving the valve body in a direction in which the valve portion is opened and closed;
a screw feed mechanism including a screw member and configured to convert a rotational motion of the rotor into a translational motion;
a can that is a cylindrical member that is fixed to the body and that 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;
an intermediate member welded to the can and disposed between the can and the body;
A stator that is inserted into the can;
Equipped with
The motor-operated valve, wherein the intermediate member is a press-molded product made of a metal material. The body has a mounting hole communicating with the fluid passage,
A female thread is provided on an inner peripheral surface of the mounting hole,
the intermediate member has a stepped cylindrical shape having a large diameter portion coaxially connected to the can and a small diameter portion inserted into the mounting hole,
7. The motor-operated valve according to claim 6, wherein an external thread portion capable of threadably engaging with the internal thread portion is provided on an outer circumferential surface of the small diameter portion. The motor-operated valve according to claim 6 or 7, characterized in that the screw member is disposed radially inside the intermediate member. a support member interposed between the screw member and the intermediate member to fix them together,
8. The motor-operated valve according to claim 6, wherein the support member is a press-formed product made of a metal material.

Images