Electric valve and refrigeration cycle system

Abstract

To provide a motor valve that enables smooth rotation even in an oil free state or a state of a low oil amount and can improve operability and durability of a sliding part by devising each material constituting the sliding part, and a refrigeration cycle system using the motor valve.SOLUTION: A motor valve 100a includes: a rotor part having a valve element 20 with a valve part 20a; and a valve body 10A having a flow passage chamber 13 and a valve port 11a extending radially. The valve body 10A includes a guide member 11 for guiding the valve element 20 in the circumferential direction. The valve part 20a includes a seal part 20aa for closing the valve port 11a and a flow passage part 15 enabling communication with the valve port 11a. Rotation of the rotor part changes the communication state between the valve port 11a and the flow passage part 15 to control a flow rate. Each of the valve element 20 and the guide member 11 constitutes a sliding part and comprises a resin material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrically operated valve having sliding parts made of resin material, and a refrigeration cycle system using the same. [Background technology]

[0002] In recent years, for the purpose of improving environmental conservation and ease of maintenance, a refrigeration cycle system has been proposed that does not use refrigerating machine oil, that is, an oil-free state or a low oil amount state, as described in Patent Document 1, for example.

[0003] A typical motor-operated valve has a drive unit with a screw feed unit that converts rotary motion into linear motion, and a sliding unit that occurs between the valve element, which moves axially due to this linear motion, and a guide unit. This increases the sliding resistance in the drive unit (especially the screw feed unit) and the sliding unit during rotation, which can make smooth rotation difficult (hereinafter referred to as the "problem of the past (increased sliding resistance)").

[0004] As shown in Fig. 10, Patent Document 2 discloses an electrically operated valve (hereinafter referred to as a "conventional electrically operated valve") 1000, which includes a valve body 1010, a valve element 1020, and a stepping motor 1030. The valve body 1010 has a valve port 1011a, a valve seat 1011b, and a cylindrical guide portion 1011c, and is connected to a first joint pipe 1001 and a second joint pipe 1002. The valve element 1020 has a valve portion 1020a and a guide shaft portion 1020g slidably engaged with the inner periphery of the guide portion 1011c. The stepping motor 1030 has a magnet rotor 1032 that rotates integrally with the valve element 1020.

[0005] For this reason, Patent Document 2 describes a configuration in which the guide shaft portion 1020g can be moved only in the rotational direction relative to the guide portion 1011c, thereby eliminating the screw feed portion and suppressing sliding resistance in the drive portion.

[0006] However, in Patent Document 2 (especially, in the first example: see paragraphs

[0042] ,

[0064] -

[0065] , and FIG. 1), the guide portion 1011c and the guide shaft portion 1020g are made of metal. Therefore, when the guide portion 1011c and the guide shaft portion 1020g are used in a refrigeration cycle system operated in an oil-free or low-oil state, the sliding resistance at the sliding portion is extremely large, which may result in galling or other problems. Also, in Patent Document 2 (especially, in the fifth example: see paragraphs

[0064] -

[0065] and FIG. 14), the guide shaft portion 1020g is coated with a synthetic resin. However, because the guide portion 1011c is made of a metal material, significant wear of the coated synthetic resin may occur, which may increase the sliding resistance at the sliding portion. Therefore, even in Patent Document 2 (especially, see the first and fifth examples), the conventional problem (increased sliding resistance) remains unresolved. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-162213 [Patent Document 2] Japanese Patent Application Publication No. 8-312822 Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide an electric valve and a refrigeration cycle system using the same that can improve the operability and durability of the sliding parts by optimizing the materials that make up the sliding parts, allowing smooth rotation even in an oil-free state or a state with a low amount of oil. [Means for solving the problem]

[0009] In order to solve the above problems, there is provided a valve body including a valve element having a valve portion provided on one end side thereof, a rotor portion having a rotor that rotates integrally with the valve element, a flow path chamber that accommodates the valve portion, a valve seat that faces the valve portion in the radial direction, and a valve port that extends radially and is capable of communicating with the flow path chamber, and a case that is connected to the valve body and defines a back pressure chamber of the rotor portion, wherein the valve body has a first port that directly communicates with the flow path chamber, a second port that communicates with the valve port, and a guide member that supports the valve element provided along an axis in the axial direction and guides it in the circumferential direction, the valve portion has a seal portion that closes the valve port, and a flow path portion that is capable of communicating with the valve port, and the rotation of the rotor changes the state of communication between the valve port and the flow path portion to control the flow rate of fluid flowing through the valve port, and the valve element and the guide member mutually constitute sliding portions and are an electrically operated valve made of a resin material.

[0010] In the motor-operated valve, the resin material may be PPS with PTFE added.

[0011] In the above-described motor-operated valve, the resin material may be added with glass fiber or carbon fiber as a reinforcing agent.

[0012] The above-mentioned electric valve may further include a radial support means that is set at a predetermined radial gap between the valve body and the guide member, which are the sliding part, and that radially supports the valve body, and the radial support means has a one-end radial gap adjacent to the valve part and an other-end radial gap adjacent to the other end side of the one-end radial gap, and the one-end radial gap may be set smaller than the other-end radial gap.

[0013] Furthermore, in the above-described electric valve, the valve body may have, in order from one end side to the other end side, a small diameter guide shaft portion having the valve portion at one end side, and a large diameter guide shaft portion, and the guide member may have, in order from one end side to the other end side, a small diameter guide portion and a large diameter guide portion, and the one end side radial gap formed between the small diameter guide shaft portion and the small diameter guide portion may be set smaller than the other end side radial gap formed between the large diameter guide shaft portion and the large diameter guide portion.

[0014] The above-described motor-operated valve may further include an axial support means for engaging axially opposing surfaces of the valve body and the guide member, which are the sliding part, and supporting the valve body in the axial direction, wherein the first port communicates with the valve port via the flow path chamber, and the valve body extends along the axis and has a pressure equalizing hole that constantly communicates between the second port and the back pressure chamber.

[0015] Furthermore, in the above-mentioned electric valve, the valve body may have an annular step portion at the boundary between the small diameter guide shaft portion and the large diameter guide shaft portion, and the guide member may have an annular step portion at the boundary between the small diameter guide portion and the large diameter guide portion, and the axial support means may be configured to engage the step portion of the valve body and the step portion of the guide member with each other.

[0016] The present invention may also be directed to a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, in which the motor-operated valve is used as the expansion valve. [Effects of the Invention]

[0017] According to the present invention, by devising the materials that make up the sliding parts, it is possible to provide an electric valve and a refrigeration cycle system using the same that enable smooth rotation even in an oil-free state or a state with a low amount of oil, and improve the operability and durability of the sliding parts. [Brief explanation of the drawings]

[0018] [Figure 1]1A and 1B are cross-sectional views of a motor-operated valve according to a first embodiment of the present invention in an open state, where FIG. 1A is a longitudinal cross-sectional view of the motor-operated valve, and FIG. 1B is an enlarged view of the Ib-Ib cross section of FIG. 1A. [Figure 2] 2A and 2B are cross-sectional views of the motor-operated valve shown in FIG. 1 in a valve-closed state, where FIG. 2A is a longitudinal cross-sectional view of the motor-operated valve, and FIG. 2B is an enlarged cross-sectional view of FIG. 2A taken along line IIb-IIb. [Figure 3] 1A and 1B are explanatory views of the first embodiment and a modified axial support means, in which (a) is an enlarged view of the area surrounded by dashed line IIIa in FIG. 2 in the first embodiment, (b) is an enlarged view of the area surrounded by dashed line IIIb in FIG. 2 in the first embodiment, (c) is an enlarged view corresponding to (a) in the modified axial support means, and (d) is an enlarged view corresponding to (b) in the modified axial support means. [Figure 4] 2(a) and 2(d) are explanatory diagrams of flow path section variants 1 and 2 of the first embodiment, where (a) is a cross-sectional view of flow path section variant 1 corresponding to FIG. 1(b), (b) is a cross-sectional view of flow path section variant 1 corresponding to FIG. 2(b), (c) is a cross-sectional view of flow path section variant 2 corresponding to (a), and (d) is a cross-sectional view of flow path section variant 2 corresponding to (b). [Figure 5] FIG. 1(b) is an explanatory view (a cross-sectional view corresponding to FIG. 1(a)) of a modified second joint pipe of the first embodiment. [Figure 6] FIG. 1(b) is an explanatory diagram (a cross-sectional view corresponding to FIG. 1(a)) of a modified valve body of the first embodiment. [Figure 7] 7A and 7B are cross-sectional views of a motor-operated valve according to a second embodiment of the present invention in an open state, where (a) is a longitudinal cross-sectional view of the motor-operated valve, (b) is an enlarged view of the VIIb-VIIb cross section of (a), and (c) is an enlarged view of the area surrounded by the dashed line VIIc of (a). [Figure 8] 8A and 8B are explanatory diagrams of a modified stopper portion of the second embodiment, in which (a) is a cross-sectional view of the main part corresponding to FIG. 7A, and (b) is a cross-sectional view taken along line VIIIb-VIIIb shown in (a). [Figure 9] 1 is a diagram showing a refrigeration cycle system of the present invention. [Figure 10]FIG. 1 is a longitudinal sectional view showing a motor-operated valve according to a conventional technique. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described in detail with reference to Figures 1 to 9. However, the present invention is not limited to this embodiment.

[0020] <Terminology> In this specification and the claims, the terms "left," "right," "upper," and "lower" refer to the directions shown in Figures 1(a), 2(a), 3, 5-6, 7(a), (c), and 8(a). In this specification and the claims, the terms "one end" and "other end" refer to the "lower end" and "upper end" in the drawings. In this specification and the claims, the term "sliding portion" refers to the "area of ​​the valve body and the guide member that are slidably engaged." In this specification and the claims, the term "cooling means" refers to the "means for cooling the sliding portion." In this specification and the claims, the term "surface pressure" refers to the "load per unit area on the contact surface." In this specification and the claims, the term "radial support means" refers to the "means for supporting the valve body in the radial direction." In this specification and the claims, the term "axial support means" refers to the "means for supporting the valve body in the axial direction."

[0021] (First embodiment) <About the configuration of the motor-operated valve> 1 and 2, a motor-operated valve 100a according to a first embodiment of the present invention will be described. The motor-operated valve 100a is mainly composed of a valve body 10A, a valve element 20, a stepping motor 30, and a support member 40. Each component of the motor-operated valve 100a will be described below in order.

[0022] Here, as will be described in detail later, the electric valve 100a in the first embodiment adopts the first measure (improving the material of the sliding parts) and by constructing both sliding parts from resin material, it is possible to eliminate the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding parts.

[0023] The valve body 10A comprises a bowl-shaped member 10 that defines a portion of the flow path chamber 13, a guide member 11 having an approximately cylindrical shape extending along the axis L and fixedly connected to the bottom side of the bowl-shaped member 10, and a lower cover 12 having a circular ring shape that is integrally molded with the guide member 11.

[0024] A first coupling pipe 1, which serves as a fluid path for a refrigerant or the like, is connected to the side surface of the bowl-shaped member 10, and a second coupling pipe 2, which serves as a fluid path for a refrigerant or the like, are connected to the bottom surface of the bowl-shaped member 10. The first coupling pipe 1 is directly connected to a flow path chamber 13 via a first port 1a. The second coupling pipe 2 is connected to the flow path chamber 13 via a second port 2a, an internal flow path 14 of a guide member 11, and a valve port 11a (described in detail below). The first coupling pipe 1 and the second coupling pipe 2 are made of a material such as copper or stainless steel, and are fixed to the bowl-shaped member 10 by brazing or the like.

[0025] An insertion hole that opens from one end to the other end along the axis L is formed in the guide member 11. A large-diameter guide portion 11cb and a small-diameter guide portion 11ca are provided in this insertion hole from the other end to the one end. The small-diameter guide portion 11ca has an inner diameter smaller than that of the large-diameter guide portion 11cb, and an internal flow path 14 that extends in the direction of the axis L is defined in the inner region on the one end side. In addition, a flat, annular step portion 11e (axially opposing surface) is formed at the boundary between the large-diameter guide portion 11cb and the small-diameter guide portion 11ca. 1(a) and 2(a), the guide member 11 is formed with a valve port 11a that is concentric with the first port 1a and is located on the opposite side of the axis L from the first coupling pipe 1 with respect to the axis L when viewed in the direction of the axis L, and that penetrates radially between the internal flow path 14 and the flow path chamber 13, and an annular valve seat 11b (see FIGS. 1(b) and 2(b)) that is formed around the valve port 11a. In addition, a drawn-out portion 11g that extends radially outward is formed on part of the outer circumferential surface of the other end of the guide member 11.

[0026] The lower cover 12 has an inner peripheral portion joined to the guide member 11 and an outer peripheral portion joined to the other end of the bowl-shaped member 10 and one end of the case 31. The lower cover 12 is formed with a communication hole 12a that constantly connects the flow path chamber 13 and the back pressure chamber 16 and functions as a pressure equalizing hole.

[0027] In the first embodiment, the shape of the valve port 11a when viewed from a direction perpendicular to the axis L is circular, but this is not limited thereto and various shapes can be adopted, such as a rectangular shape, an elliptical shape, or any asymmetric shape. Also, in the first embodiment, the bowl-shaped member 10 and the guide member 11 are separate bodies, but this is not limited thereto and, for example, the bowl-shaped member 10 and the guide member 11 may be formed integrally as in the conventional motor-operated valve shown in FIG.

[0028] The valve element 20 is a member extending along the axis L. One end of the valve element 20 is inserted into an insertion hole in the guide member 11. From one end to the other, a small-diameter guide shaft portion 20g and a large-diameter guide shaft portion 20h, each having a valve portion 20a at one end, are formed with successively increasing diameters in a stepped manner. At the boundary between the small-diameter guide shaft portion 20g and the large-diameter guide shaft portion 20h, a flat, annular one-end step portion 20i (step portion, axially opposing surface) is formed. Here, the valve portion 20a has the same outer diameter as the small-diameter guide shaft portion 20g. As shown in FIGS. 1(b) and 2(b), the valve portion 20a has a substantially fan-shaped shape when viewed from the direction of the axis L, and includes a flow path portion 15 that opens to one end of the valve portion 20a in the direction of the axis L. As will be described in detail later, as shown in FIG. 3(a), the small-diameter guide shaft portion 20g, the one-end step portion 20i, and the large-diameter guide shaft portion 20h each have a sliding portion that slidably engages with the small-diameter guide portion 11ca, the step portion 11e, and the large-diameter guide portion 11cb of the guide member 11, respectively. This allows the valve element 20 in the first embodiment to have a relatively small radial size and a lighter weight, thereby improving energy efficiency in the stepping motor 30. Furthermore, the other end of the valve element 20 includes a other-end step portion 20ka that is fixed to the hub 35 of the magnet rotor 32, and a other-end bottomed cylindrical portion 20c that extends along the axis L to the other end and opens. A support member 40 that biases the valve element 20 toward the one end is housed in the other-end bottomed cylindrical portion 20c.

[0029] As shown in Figures 2(a) and 3(b), the valve element 20 has a protrusion 20kb extending downward from the disk portion 20k. When the valve portion 20a rotates relative to the guide member 11, this protrusion 20kb abuts against the drawn-out portion 11g of the guide member 11, which functions as a stopper, thereby restricting the rotation of the valve portion 20a. Note that, as shown in Figure 3(b), the other end 11h of the guide member 11 is spaced apart from the disk portion 20k of the valve element 20.

[0030] The stepping motor 30 includes a case 31 , a magnet rotor 32 , and a stator coil 33 .

[0031] The case 31 is made of a metal such as stainless steel and is formed in a generally cylindrical shape with a closed upper end, defining a back pressure chamber 16 that houses the valve body 20 and the magnet rotor 32. The lower open end of the case 31 is airtightly fixed to the outer periphery of the bottom cover 12 by welding or the like.

[0032] The magnet rotor 32 integrally comprises a cylindrical magnet portion 34 whose outer periphery is magnetized with multiple poles, and a hub 35 connected via spokes to the inner periphery of the magnet portion 34. The valve element 20 is inserted into the inside of the hub 35 of the magnet rotor 32 toward the other end in the direction of the axis L, and the other end step 20ka of the valve element 20 is brought into contact with one end of the hub 35. A bushing 43 of a support member 40 (described below) is incorporated into the other end bottomed cylindrical portion 20c and brought into contact with the other end of the hub 35, and then the magnet rotor 32, which constitutes the rotor portion, and the valve element 20 are integrally fixed to the hub 35 by welding or the like. This allows the rotor portion to be rotatable within the case 31 about the axis L.

[0033] The stator coil 33 is disposed on the outer peripheral surface of the case 31, and when a pulse signal is given to the stator coil 33, the magnet rotor 32 is rotated in accordance with the number of pulses.

[0034] In this way, when the magnet rotor 32 rotates, the valve section 20a rotates together with the magnet rotor 32 relative to the valve port 11a, changing the opening between the flow path section 15 and the valve port 11a, and controlling the flow rate of the fluid flowing from the first joint pipe 1 to the second joint pipe 2 (or from the second joint pipe 2 to the first joint pipe 1).

[0035] The support member 40 includes a spring receiving portion 41 that is rotatably arranged in contact with the case 31, a bushing 43 that is fixed to the bottomed cylindrical portion 20c on the other end side and the hub 35, and a biasing spring 42 that is sandwiched between the spring receiving portion 41 and the bushing 43 and biases the valve body 20 toward one end.

[0036] <Operation of the motor-operated valve> The operation of the motor-operated valve 100a will be described using Figures 1 and 2. Here, the motor-operated valve 100a will be described as being used in a refrigerant circuit, but this is not limited to this. In the motor-operated valve 100a, the first joint pipe 1 is connected to the high-pressure (primary pressure) side, and the second joint pipe 2 is connected to the low-pressure (secondary pressure) side. Note that a similar explanation can be given for the case where the second joint pipe 2 is connected to the high-pressure side and the first joint pipe 1 is connected to the low-pressure side (broken lines in Figures 1(a) and 1(b)), which is the opposite case, and therefore this will not be described here.

[0037] First, as shown in FIG. 1(b), the valve portion 20a is rotated counterclockwise by the magnet rotor 32. As a result, the protrusion 20kb of the valve element 20 abuts against the drawn-out portion 11g of the guide member 11 (not shown), restricting the rotation of the valve portion 20a and the magnet rotor 32. At this time, the flow path portion 15 faces the valve port 11a, resulting in an open valve state. Therefore, fluid flows from the first port 1a on the high-pressure side to the second port 2a on the low-pressure side, as indicated by the solid arrows in FIGS. 1(a) and 1(b). To prevent pressure loss in the fluid path, the flow path areas of the flow path chamber 13 and the flow path portion 15, located before and after the valve port 11a, are set larger than the flow path area of ​​the valve port 11a.

[0038] Next, as shown in FIG. 2(b), the valve portion 20a is rotated clockwise by the magnet rotor 32. As shown in FIG. 2(a), the protrusion 20kb of the valve element 20 abuts against the drawn-out portion 11g of the guide member 11, restricting the rotation of the valve portion 20a and the magnet rotor 32. At this time, the flow path 15 faces the valve seat 11b, and the valve port 11a faces the seal portion 20aa, resulting in a valve-closed state. Therefore, the flow path from the first port 1a on the high-pressure side to the second port 2a on the low-pressure side is closed. In this embodiment, the valve portion 20a of the valve element 20 and the small-diameter guide shaft portion 20g have the same outer diameter. However, the refrigeration cycle system requires a small amount of fluid to pass through even when the motor-operated valve 100a is closed. In this case, the flow rate required when the valve is closed can be set arbitrarily by making the outer diameter of the valve portion 20a smaller than the outer diameter of the small diameter guide shaft portion 20g and adjusting the amount of gap between the valve port 11a and the seal portion 20aa.

[0039] The flow path portion 15 in the first embodiment has a substantially fan-shaped shape when viewed from the direction of the axis L. Therefore, in the motor-operated valve 100a in the first embodiment, when the flow path portion 15 rotates with respect to the valve port 11a and transitions from one of the valve open state and the valve closed state to the other, the flow path area rapidly decreases or increases immediately after the transition, and therefore the motor-operated valve can be used, for example, as an on-off valve.

[0040] Although the flow path section 15 in the first embodiment has a substantially fan-shaped shape when viewed in the direction of the axis L, the present invention is not limited to this. For example, if the flow path section 15 in the first embodiment has a semicircular shape that is eccentric with respect to the axis L when viewed in the direction of the axis L, in the motor-operated valve 100a, when the flow path section 15 rotates with respect to the valve port 11a and transitions from one of the valve open state and the valve closed state to the other, the flow path area gradually decreases or increases, enabling fine flow rate control, and therefore the motor-operated valve 100a can be used, for example, as a flow rate adjustment valve. Furthermore, when the flow path section 15 in the first embodiment has a shape that combines an approximately fan-shaped shape and a semicircular shape that is eccentric with respect to the axis L when viewed from the direction of the axis L, in the electric valve 100a, when the flow path section 15 rotates relative to the valve port 11a and transitions from one of the valve open state and the valve closed state to the other, the flow path area decreases abruptly immediately after the transition and then the flow path area changes gradually, or the flow path area changes gradually and then the flow path area increases abruptly, so that the electric valve can be used, for example, as an opening / closing valve with the added function of a flow control valve.

[0041] <Details of the sliding part> As described above with reference to FIG. 10 , in the conventional motor-operated valve 1000, the sliding portion consisting of the guide portion 1011c and the guide shaft portion 1020g is made of either metallic materials or metallic materials coated with synthetic resin. Therefore, when the conventional motor-operated valve 1000 is used in a refrigeration cycle system operated in an oil-free or low-oil state, there is no fluid lubrication film of refrigerant oil between the guide portion 1011c and the guide shaft portion 1020g, or only a relatively thin fluid lubrication film. This can result in significant mechanical wear, such as adhesion wear on the sliding surfaces or abrasive wear due to unevenness on the sliding surfaces, which can increase the sliding resistance of the sliding portion. Therefore, the conventional motor-operated valve still fails to solve the problem of increased sliding resistance.

[0042] In response to this, the motor-operated valve 100a of the first embodiment takes the following first measure (improving the material of the sliding part) to solve the conventional problem (increased sliding resistance). In addition, as will be described in detail later, after taking the first measure (improving the material of the sliding part), further measures (heat-resistant means for the sliding part) and third measures (cooling means (valve part) for the sliding part) are taken to address concerns.

[0043] <First measure (improving the material of the sliding part)> In the motor-operated valve 100a of the first embodiment, the first measure (improving the material of the sliding part) is to solve the conventional problem (increased sliding resistance) by improving the material that constitutes the sliding part. Specifically, in the motor-operated valve 100a of the first embodiment, the valve body 20 and the guide member 11 that constitute the sliding part are both made of a resin material.

[0044] Generally, resin materials have a relatively low coefficient of dynamic friction (e.g., approximately 0.04 for polytetrafluoroethylene (PTFE), approximately 0.11 for ultra-high molecular weight polyethylene, and approximately 0.18 for monomer-cast nylon), resulting in excellent sliding properties. Furthermore, the sliding parts of the motor-operated valve 100a of the first embodiment have relatively low surface pressure and relative sliding speed, and the sliding time is also relatively short. Therefore, in the motor-operated valve 100a of the first embodiment, as a first measure (improving the material of the sliding parts), the valve element 20 and the guide member 11 are both made of resin material. This significantly reduces dynamic friction even in an oil-free state or a low-oil state, thereby resolving the conventional problem (increased sliding resistance) and enabling smooth rotation of the sliding parts. As a result, the operability and durability of the sliding parts of the motor-operated valve 100a can be improved.

[0045] Here, even if the first countermeasure (improving the material of the sliding portion) is adopted in the motor-operated valve 100a of the first embodiment, if an unexpected situation occurs and the surface pressure and relative sliding speed of the sliding portion (valve element 20 and guide member 11) become relatively large, the dynamic friction force becomes extremely large, and relatively high frictional heat (e.g., 200°C) may be generated. In this case, since the melting point of a typical resin material is between 100 and 200°C, if resin materials melt together, there is a risk of the resin materials melting together (hereinafter referred to as "concern (melting of the sliding portion)"). Therefore, in the first embodiment, by further adopting the second countermeasure (heat-resistant means for the sliding portion), the concern (melting of the sliding portion) can be resolved and the operability and durability of the sliding portion can be further improved.

[0046] <Second measure (heat resistance of sliding parts)> In the motor-operated valve 100a of the first embodiment, as a second measure (heat-resistant means for the sliding parts), polyphenylene sulfide (PPS) containing polytetrafluoroethylene (PTFE) is used as the resin material for the valve body 20 and the guide member 11. This PPS has very high heat resistance (for example, the heat-resistant temperature of PPS is about 220°C) and also has good lubricity.

[0047] As a result, by adopting the second measure (heat-resistant means for the sliding part) in the electric valve 100a of the first embodiment, the sliding part has extremely high heat resistance and lubricity, so even if an unexpected situation occurs and relatively high frictional heat is generated, the resin material will not melt, thereby eliminating the concern (melting of the sliding part) and further improving the operability and durability of the sliding part.

[0048] Additionally, in the motor-operated valve 100a of the first embodiment, the resin material of the valve body 20 and the guide member 11 may be PPS, which is polytetrafluoroethylene (PTFE) reinforced with glass fiber or carbon fiber. This PPS has very high tensile strength (e.g., 150 MPa) and heat resistance (e.g., heat resistance temperature of about 230°C).

[0049] As a result, by adopting the second measure (heat-resistant means for the sliding part) in the electric valve 100a of the first embodiment, the sliding part has extremely high heat resistance and strength, so even if an unexpected situation occurs and relatively high frictional heat is generated, the resin material will not melt, thereby eliminating the concern (melting of the sliding part) and further improving the operability and durability of the sliding part.

[0050] <Third measure (cooling means for sliding parts (valve parts))> In the motor-operated valve 100a of the first embodiment, even if the second measure (heat-resistant means for the sliding part) is adopted to resolve the concern (melting of the sliding part), frictional heat is still generated in the sliding part. Therefore, if no measures are taken to prevent the generation of this frictional heat itself, even slight dimensional changes will occur in the sliding part made of a resin material, and there is a concern that the sliding part will deviate from its optimal sliding state (hereinafter referred to as "concern (dimensional change of the sliding part)"). Therefore, in the motor-operated valve 100a of the first embodiment, the third measure (cooling means (valve part) for the sliding part) is adopted to resolve the concern (dimensional change of the sliding part).

[0051] As shown in Fig. 3(a), the electric valve 100a of the first embodiment has a radial support means for supporting the valve body 20 in the radial direction by the slidable engagement between the small-diameter guide shaft portion 20g and the small-diameter guide portion 11ca, and between the large-diameter guide shaft portion 20h and the large-diameter guide portion 11cb, and an axial support means for supporting the valve body 20 in the axial direction by the slidable engagement between the one-end-side stepped portion 20i and the stepped portion 11e. Here, as the third countermeasure (cooling means for the sliding portion (valve portion)), the electric valve 100a of the first embodiment sets the one-end-side radial gap G1 (radial gap) adjacent to the valve portion 20a to be smaller (G1 < G2) than the other-end-side radial gap G2 (radial gap). Specifically, in the radial support means, as shown in Fig. 3(a), the one-end-side radial gap G1 formed between the small-diameter guide shaft portion 20g having the valve portion 20a on the one-end side and the small-diameter guide portion 11ca is set to be smaller than the other-end-side radial gap G2 formed between the large-diameter guide shaft portion 20h and the large-diameter guide portion 11cb. Thus, when the third countermeasure (cooling means for the sliding portion (valve portion)) is adopted in the electric valve 100a of the first embodiment, the substantial sliding portion is composed of the small-diameter guide shaft portion 20g having the valve portion 20a on the one-end side and the small-diameter guide portion 11ca. In the radial support means, since the sliding area can be made relatively small and the sliding resistance can be reduced, the operability and durability of the sliding portion can be further improved. Furthermore, since the one-end-side radial gap G1 is relatively small, as shown in Fig. 2(b), the sealing performance of the valve portion 20a in the valve-closed state is improved, and valve leakage can be suppressed.

[0052] Here, to specifically explain the third measure (cooling means for the sliding portion (valve portion)), the temperature of the fluid in the motor-operated valve 100a of the first embodiment will be considered with reference to FIG. 1(a). First, when the fluid flows from the first port 1a into the flow path chamber 13, it is at a medium temperature (e.g., approximately 60 to 70°C). However, when the fluid flows into the internal flow path 14 via the valve port 11a and the flow path portion 15, it expands (decompresses) and becomes a low temperature (e.g., approximately −10 to 20°C). As a result, in the valve open state, the valve portion 20a is actively cooled by the low-temperature fluid. Therefore, by adopting the third measure (cooling means for the sliding portion (valve portion)), not only the valve portion 20a but also the small-diameter guide shaft portion 20g and the small-diameter guide portion 11ca, which have the valve portion 20a at one end thereof, are actively cooled. This resolves the concern (dimensional change of the sliding portion) and further improves the operability and durability of the sliding portion.

[0053] As described above, the motor-operated valve 100a in the first embodiment can solve the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding part by adopting the first measure (improving the material of the sliding part). Also, by adopting the second measure (heat-resistant means for the sliding part) and solving the concern (melting of the sliding part), and by adopting the third measure (cooling means (valve part) for the sliding part) and solving the concern (dimensional change of the sliding part), the operability and durability of the sliding part can be further improved.

[0054] In the electric valve 100a of the first embodiment, the first measure (improving the material of the sliding part), the second measure (heat-resistant means for the sliding part), and the third measure (cooling means for the sliding part (valve part)) are adopted, but this is not limited to this. For example, the first measure (improving the material of the sliding part) may be adopted, and then the second measure (heat-resistant means for the sliding part) or the third measure (cooling means for the sliding part (valve part)) may be adopted.

[0055] (Modification of the axial support means of the first embodiment) 3(c) and (d), a modified axial support means of the first embodiment will be described. The modified axial support means of the first embodiment differs from the first embodiment in that the axial support means is disposed apart from the radial support means, but other configurations are the same as those of the first embodiment. Here, the same components are given the same reference numerals, and duplicated explanations will be omitted.

[0056] Specifically, as shown in FIG. 3(c), the radial support means radially slidably engages the small-diameter guide shaft portion 20g with the small-diameter guide portion 11ca, and the large-diameter guide shaft portion 20h with the large-diameter guide portion 11cb, as in the first embodiment. Meanwhile, instead of separating the one-end step portion 20i' and the step portion 11e in the axial direction as shown in FIG. 3(c), the axial support means slidably engages one end face (axially opposing surface) of the disk portion 20k with the other end portion 11h' (axially opposing surface) of the guide member 11' in the axial direction as shown in FIG. 3(d). In this way, in the motor-operated valve 100b, the axial support means is spaced apart from the radial support means to disperse frictional heat generated in the sliding portions. This reliably eliminates the concern regarding the radial support means (dimensional change of the sliding portions). It should be noted that frictional heat generated in the axial support means can be dissipated to the fluid in the back pressure chamber 16 .

[0057] As described above, the motor-operated valve 100b in the modified axial support means of the first embodiment, like the first embodiment, can solve the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding part by adopting the first measure (improving the material of the sliding part). Also, by adopting the second measure (heat-resistant means for the sliding part) and / or the third measure (cooling means (valve part) for the sliding part), the concern (melting of the sliding part) and / or the concern (dimensional change of the sliding part) can be solved, and the operability and durability of the sliding part can be further improved.

[0058] In addition, the electric valve 100b in the modified axial support means of the first embodiment is configured so that the axial support means is spaced apart from the radial support means, thereby dispersing the frictional heat generated in the sliding part, thereby reliably eliminating concerns about the radial support means (dimensional changes in the sliding part).

[0059] (Modifications 1 and 2 of the flow path section of the first embodiment) Flow path section modifications 1 and 2 of the first embodiment will be described using FIG. 4. Flow path section modifications 1 and 2 of the first embodiment differ from the flow path section 15 of the valve section 20a of the first embodiment in the shapes of the flow path sections 15'', 15''' in the valve sections 20a'', 20a''', but the other basic configurations are the same as those of the first embodiment. Here, the same components are denoted by the same reference numerals, and duplicated explanations will be omitted. Note that FIGS. 4(a), (c) and 4(b), (d) correspond to FIGS. 1(b) and 2(b), respectively, but for convenience, only the valve sections 20a'', 20a''' and the guide member 11 are shown.

[0060] (Modification 1 of the flow path section of the first embodiment) 4(a) and 4(b), the flow path section 15'' of the valve section 20a'' in the flow path section variation 1 of the first embodiment will be described. This flow path section 15'' differs from the flow path section 15 of the first embodiment in that it has a semicircular shape that is eccentric with respect to the axis L when viewed in the direction of the axis L, but other configurations are the same as those of the flow path section 15 of the first embodiment.

[0061] When the flow path section 15'' rotates relative to the valve port 11a and transitions from one of the valve open state and the valve closed state to the other, the flow path area gradually decreases or increases. Therefore, in the motor-operated valve 100c in the flow path section variation 1 of the first embodiment, precise flow rate control is possible by adjusting the rotation angle of the magnet rotor 32, and therefore the motor-operated valve 100c can be used, for example, as a flow rate adjustment valve.

[0062] (Modification 2 of the flow path section of the first embodiment) 4(c) and (d), the flow path section 15''' of the valve section 20a''' in flow path section variation 2 of the first embodiment will be described. This flow path section 15''' differs from the flow path section 15 of the first embodiment in that it has a shape that combines the flow path section 15 of the first embodiment with the flow path section 15'' of flow path section variation 1 of the first embodiment, but other configurations are the same as those of the flow path section 15 of the first embodiment.

[0063] Specifically, the flow path section 15''' has a shape that combines a substantially fan-shaped shape and a semicircular shape that is eccentric with respect to the axis L when viewed from the direction of the axis L. Therefore, in the motor-operated valve 100d in the flow path section variation 2 of the first embodiment, when the flow path section 15''' rotates with respect to the valve port 11a and transitions from one of the valve open state and the valve closed state to the other, the flow path area decreases abruptly immediately after the transition and then gradually decreases, or the flow path area changes gradually and then suddenly increases, so that flow rate control is possible by combining abrupt and gradual changes in the flow path area, and therefore the motor-operated valve can be used, for example, as an opening / closing valve that has the added function of a flow rate adjustment valve.

[0064] As described above, the motor-operated valves 100c and 100d in the flow path portion modifications 1 and 2 of the first embodiment, like the first embodiment, can solve the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding portion by adopting the first measure (improving the material of the sliding portion). Also, by adopting the second measure (heat-resistant means for the sliding portion) and / or the third measure (cooling means (valve portion) for the sliding portion), the concerns (melting of the sliding portion) and / or the concerns (dimensional change of the sliding portion) can be solved, and the operability and durability of the sliding portion can be further improved.

[0065] (Modification of the second joint pipe of the first embodiment) A modified second joint pipe of the first embodiment will be described using Figure 5. The connection mode of the second joint pipe 2' in the modified second joint pipe of the first embodiment differs from that of the first embodiment in that the second joint pipe 2' is arranged so as to extend in a direction perpendicular to the axis L relative to the valve body 10A', but the other configurations are the same as those of the first embodiment. Here, the same configurations are given the same symbols, and duplicated explanations will be omitted.

[0066] Specifically, a connection chamber 18 into which the guide member 11 is fitted and fixed is formed on the bottom side of the bowl-shaped member 10'. The second joint pipe 2' is connected radially from this connection chamber 18. In this way, in the motor-operated valve 100e, by arranging the second joint pipe 2' to extend in a direction perpendicular to the axis L, it is possible to reduce the height in the direction of the axis L.

[0067] As described above, the motor-operated valve 100e in the second joint pipe modification of the first embodiment, like the first embodiment, can solve the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding part by adopting the first measure (improving the material of the sliding part). Also, by adopting the second measure (heat-resistant means for the sliding part) and / or the third measure (cooling means (valve part) for the sliding part), the concern (melting of the sliding part) and / or the concern (dimensional change of the sliding part) can be solved, and the operability and durability of the sliding part can be further improved.

[0068] (Valve body modification of the first embodiment) A modified valve element of the first embodiment will be described with reference to Figure 6. The modified valve element of the first embodiment differs from the first embodiment in that pressure equalizing holes (axial hole 20l and through hole 20m) that constantly communicate between the internal flow path 14 and the back pressure chamber 16 are formed in the valve element 20'''', but the other configurations are the same as those of the first embodiment. Here, the same configurations are given the same symbols, and duplicated explanations will be omitted.

[0069] <About the configuration of the motor-operated valve> A motor-operated valve 100f according to a modified valve element of the first embodiment of the present invention will be described using Figure 6. The motor-operated valve 100f is mainly composed of a valve body 10A", a valve element 20"", a stepping motor 30, and a support member 40. Here, the valve body 10A" and the valve element 20"" will be described in order, focusing on the differences from the first embodiment.

[0070] The valve body 10A'' has a lower cover 12' having a circular ring shape that is integrally molded with the guide member 11, as in the first embodiment. However, this lower cover 12' does not have a communication hole that constantly connects the flow path chamber 13 and the back pressure chamber 16 and functions as a pressure equalization hole, which is different from the first embodiment. The other configurations are the same.

[0071] The valve body 20'''' differs from the first embodiment in that it is provided with an axial hole 20l that passes through between the internal flow path 14 and the other-end bottomed cylindrical portion 20c along the axis L, and a through hole 20m that passes through in the radial direction between the other-end bottomed cylindrical portion 20c and the back pressure chamber 16. The other configuration is the same as that of the first embodiment. This through hole 20m is disposed between the other end 11h of the guide member 11 and the disk portion 20k of the valve body 20''''.

[0072] <Fourth measure (cooling means for sliding parts (pressure equalizing hole))> In the motor-operated valve 100f in the valve body modification of the first embodiment, similarly to the first embodiment, a first measure (improving the material of the sliding part) is taken to solve the conventional problem (increased sliding resistance), and then a second measure (heat-resistant means for the sliding part) and a third measure (cooling means for the sliding part (valve part)) are further taken to address the concerns (melting of the sliding part) and the concerns (dimensional change of the sliding part). Furthermore, in the motor-operated valve 100f in the valve body modification of the first embodiment, a fourth measure (cooling means for the sliding part (pressure equalizing hole)) is taken to address the concern (dimensional change of the sliding part).

[0073] Here, the electric valve 100f in the valve body modification example of the first embodiment, similar to the first embodiment, has a radial support means for supporting the valve body 20'''' in the radial direction by the slidable engagement of the small-diameter guide shaft portion 20g and the small-diameter guide portion 11ca, and an axial support means for supporting the valve body 20'''' in the axial direction by the slidable engagement of the one-end-side stepped portion 20i and the stepped portion 11e. Although not shown, a one-end-side radial clearance G1 (radial clearance) is set to be smaller than the other-end-side radial clearance G2 (radial clearance) (G1 < G2) (see Fig. 3(a)). Also, as shown in Fig. 6, in the electric valve 100f in the valve body modification example of the first embodiment, an axial hole 20l, an other-end-side bottomed cylindrical portion 20c, and a through hole 20m, which function as pressure equalizing holes, are formed in the valve body 20''''. Through this pressure equalizing hole, the internal flow path 14 and the back pressure chamber 16 are always in communication.

[0074] Although overlapping with the description in the third countermeasure (cooling means for the sliding portion (valve portion)), when the fluid flows into the internal flow path 14 through the valve port 11a and the flow path portion 15, it expands (decompresses) and thus becomes at a low temperature (for example, about -10 to 20°C). Therefore, in the valve open state, when this low-temperature fluid is introduced into the axial hole 20l of the valve body 20'''', particularly, the radial support means and the axial support means located on the one-end side of the valve body 20'''' are actively cooled from the inside, thereby eliminating the concern (dimensional change of the sliding portion) and reliably improving the operability and durability of the sliding portion.

[0075] In addition, in the electric valve 100f in the valve body modification example of the first embodiment, since the valve body 20'''' has a pressure equalizing hole, whether it is the case of flowing from the first port 1a on the high-pressure side to the second port 2a on the low-pressure side (see the solid line in the figure) (hereinafter referred to as "forward flow") or the case of flowing from the second port 2a on the high-pressure side to the first port 1a on the low-pressure side (see the dashed line in the figure) (hereinafter referred to as "reverse flow"), the surface pressure of the sliding portion in the axial support means can be maintained at a desired value. The following is a specific explanation of the surface pressure of the sliding portion in the axial support means.

[0076] <Comparative Example: Surface Pressure of Sliding Portion in First Embodiment> First, for better understanding, the pressing force caused by the differential pressure generated in the valve element 20 will be explained using the motor-operated valve 100a of the first embodiment shown in FIG. 1. In this motor-operated valve 100a, the first port 1a is constantly connected to the back pressure chamber 16 via the flow path chamber 13 and the communication hole 12a of the bottom cover 12. Therefore, the pressure introduced into the back pressure chamber 16 fluctuates between the forward flow (see the solid line in the figure) and the reverse flow (see the dashed line in the figure). That is, in the forward flow, the fluid in the back pressure chamber 16 is at high pressure while the fluid in the internal flow path 14 is at low pressure, so that the pressing force caused by the differential pressure generated in the axial direction L of the valve element 20 is generated toward one end (downward). In contrast, in the reverse flow, the fluid in the back pressure chamber 16 is at low pressure while the fluid in the internal flow path 14 is at high pressure, so that the pressing force caused by the differential pressure generated in the axial direction L of the valve element 20 is generated toward the other end (upward).

[0077] Therefore, in the motor-operated valve 100a of the first embodiment, the difference in the pressing force on the valve element 20 due to the differential pressure in the case of a forward flow and a reverse flow is slightly large, so the spring load of the biasing spring 42 (which biases the valve element 20 towards one end) that can withstand the pressing force due to the maximum differential pressure is set using the case of a reverse flow (the pressing force towards the other end (upper) due to the differential pressure) as a reference to prevent the valve element 20 from wobbling. As a result, in the motor-operated valve 100a, the surface pressure of the sliding part of the axial support means is slightly larger in the case of a forward flow than in the case of a reverse flow, due to the difference in the pressing force due to the differential pressure.

[0078] <Surface pressure of sliding portion of modified valve body of first embodiment> In contrast, in the motor-operated valve 100f according to the valve element modification of the first embodiment, as shown in FIG. 6, in the case of a forward flow, the fluid in the back pressure chamber 16 and the internal flow path 14 are both at low pressure, so the pressing force due to the pressure difference occurring in the axial direction L of the valve element 20'''' is substantially canceled. In the case of a reverse flow, the fluid in the back pressure chamber 16 and the internal flow path 14 are both at high pressure, so the pressing force due to the pressure difference occurring in the axial direction L of the valve element 20'''' is substantially canceled.

[0079] Therefore, in the motor-operated valve 100f according to the valve element modification of the first embodiment, there is no difference in pressing force due to a pressure difference between the forward flow and the reverse flow, so the spring load of the biasing spring 42 (which biases the valve element 20 toward one end) can be set to the minimum necessary value to prevent wobbling of the valve element 20. As a result, in the motor-operated valve 100f, the surface pressure of the sliding portion of the axial support means can be maintained at a desired value in both the forward flow and the reverse flow.

[0080] As described above, the motor-operated valve 100f according to the valve element modification of the first embodiment, like the first embodiment, employs the first measure (improving the material of the sliding part) to solve the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding part. Furthermore, employing the second measure (heat-resistant means for the sliding part) solves the concern (melting of the sliding part). Additionally, employing the third measure (cooling means for the sliding part (valve part)) and the fourth measure (cooling means for the sliding part (pressure-equalizing hole)) reliably solves the concern (dimensional change of the sliding part), further improving the operability and durability of the sliding part and maintaining the surface pressure of the sliding part in the axial support means at a desired value.

[0081] In addition, the electric valve 100f in the valve body modification of the first embodiment adopts the first measure (improving the material of the sliding part), the second measure (heat-resistant means for the sliding part), the third measure (cooling means for the sliding part (valve part)) and the fourth measure (cooling means for the sliding part (pressure equalizing hole)), but is not limited to this. For example, it is also possible to adopt the first measure (improving the material of the sliding part) and then adopt the third measure (cooling means for the sliding part (valve part)) and the fourth measure (cooling means for the sliding part (pressure equalizing hole)).

[0082] (Second embodiment) A motor-operated valve 100g according to a second embodiment of the present invention will be described using Figure 7. The motor-operated valve 100g according to the second embodiment differs from the motor-operated valve 100a of the first embodiment mainly in the radial arrangement of the valve body 20B and the guide member 11B and the connection mode of the first joint pipe 1B and the second joint pipe 2B, but the other basic configuration is substantially the same as that of the first embodiment. Here, the same configuration is given the same reference numeral, and duplicated explanations will be omitted.

[0083] As will be described in detail later, the electric valve 100g in the second embodiment, like the first embodiment, takes a first measure (improving the material of the sliding part) to solve the conventional problem (increased sliding resistance), and then further takes a second measure (heat-resistant means for the sliding part) and a third measure (cooling means (valve part) for the sliding part) to address the concerns (melting of the sliding part) and the concerns (dimensional changes of the sliding part).

[0084] <About the configuration of the motor-operated valve> 7, the motor-operated valve 100g is mainly composed of a valve body 10B, a valve element 20B, a stepping motor 30B, and a support member 40B. Each component of the motor-operated valve 100g will be described below in order.

[0085] The valve body 10B comprises a bowl-shaped member 10Ba that defines a portion of the flow path chamber 13, and a guide member 11B that has a generally cylindrical shape extending along the axis L and is fixedly connected to the bottom side of the bowl-shaped member 10Ba.

[0086] A first joint pipe 1B and a second joint pipe 2B, which serve as fluid paths for a refrigerant or the like, are connected to the bottom side of the bowl-shaped member 10Ba. The first joint pipe 1B is directly connected to the flow path chamber 13 via the first port 1Ba. The second joint pipe 2B is abutted against one end of the guide member 11B and is connected to the flow path chamber 13 via the second port 2Ba, the internal flow path 14 of the guide member 11B, and a valve port 11Ba (described in detail below). The first joint pipe 1B and the second joint pipe 2B are made of materials such as copper or stainless steel, and are fixed to the bowl-shaped member 10Ba by brazing or the like. As shown in FIG. 7(b), the bowl-shaped member 10Ba is provided with a raised portion 10Baa that is located on the opposite side of the first joint pipe 1B with respect to the axis L when viewed from the direction of the axis L and that protrudes toward the flow path chamber 13.

[0087] The guide member 11B has a significantly different structure from approximately the center in the axial direction L to one end side and the other end side. First, the guide member 11B from approximately the center in the axial direction L to one end side has a bottomed cylindrical shape, and includes an internal flow path 14 extending in the axial direction L, a valve port 11Ba radially penetrating the guide member 11B at the other end side of the internal flow path 14, an annular valve seat 11Bb formed around the valve port 11Ba, a guide portion 11Bd that guides the valve body 20B in the circumferential direction, and an annular reduced-diameter portion 11Bc (see FIG. 7(c)). The reduced-diameter portion 11Bc has a smaller outer diameter than the guide portion 11Bd. Next, the guide member 11B from approximately the center in the axial direction L to the other end side has a solid shape, and a flat support portion 11Be is formed at the other end of the guide member 11B. 7(b), the valve port 11Ba is located on the opposite side of the first port 1Ba with respect to the axis L when viewed in the direction of the axis L. In the second embodiment, the shape of the valve port 11Ba when viewed in a direction perpendicular to the axis L is circular, but this is not limiting and various shapes can be adopted, such as a rectangular shape, an elliptical shape, or any asymmetric shape.

[0088] In the second embodiment, the bowl-shaped member 10Ba and the guide member 11B are separate bodies, but this is not limiting. For example, the bowl-shaped member 10Ba and the guide member 11B may be integrally formed as in the conventional motor-operated valve shown in FIG. 10.

[0089] The valve element 20B is a member extending along the axis L. A valve portion 20Ba is formed on one end of the valve element 20B. The inside of the valve element 20B is provided with a one-end-side bottomed cylindrical portion 20Bb extending toward one end along the axis L, and an other-end-side bottomed cylindrical portion 20Bc extending toward the other end along the axis L. The outer periphery of the valve element 20B is provided with a flange portion 20Bg protruding in a disk shape from the radially outer side of the valve portion 20Ba, and a protrusion 20Be extending from the flange portion 20Bg, protruding from the radially outer side of the valve portion 20Ba, and capable of coming into contact with the raised portion 10Baa of the bowl-shaped member 10Ba when the valve element 20B rotates. Furthermore, the valve body 20B has, on its outer periphery, a step 20Bd into which the magnet rotor 32B is fitted and abuts, and an annular groove 20Bf that holds the retaining ring 17, as will be described in detail later.

[0090] The guide member 11B, which guides the valve body 20B in the circumferential direction, is inserted into the bottomed cylindrical portion 20Bb with a small radial gap to allow sliding movement. The bottomed cylindrical portion 20Bb and the guide portion 11Bd have sliding portions that slidably engage with each other. This enhances the stability of the rotational state of the valve body 20B. The other end 20Bba of the bottomed cylindrical portion 20Bb, which abuts against the support portion 11Be of the guide member 11B, has a flat shape corresponding to the support portion 11Be. The slidable engagement between the other end 20Bba and the support portion 11Be provides an axial support means that supports the valve body 20B in the axial direction. Furthermore, the one-end bottomed cylindrical portion 20Bb, as will be described in detail later, has a seal portion 20Baa that is in annular sliding contact with the valve seat 11Bb of the guide member 11B, and a flow path portion 15B that has a shape that, when viewed from the direction of the axis L, is a combination of a substantially fan shape and a semicircular shape that is eccentric with respect to the axis L, and that extends and opens to one end side in the direction of the axis L. As shown in FIG. 7(a), one end of this flow path portion 15B is located on one end side in the direction of the axis L with respect to the valve port 11Ba, and the other end of the flow path portion 15B is located on the other end side in the direction of the axis L with respect to the valve port 11Ba. Note that, although the shape of the support portion 11Be of the guide member 11B is flat in the second embodiment, it is not limited to this and may be, for example, hemispherical or convex. This makes the contact area between the support portion 11Be of the guide member 11B and the other end portion 20Bba of the valve body 20B extremely small, reducing sliding resistance and making it easier for the valve body 20B to rotate.

[0091] The other end side bottomed cylindrical portion 20Bc accommodates a support member 40B that biases the valve body 20B toward one end side.

[0092] Therefore, as the valve portion 20Ba rotates relative to the guide member 11B, the communication state between the flow path portion 15B of the valve portion 20Ba and the valve port 11Ba of the guide member 11B changes between a valve open state (see FIGS. 7(a) and 7(b)) and a valve closed state (not shown) (or a minimum opening), thereby adjusting the flow rate. At this time, as shown in FIG. 7(b), the protrusion 20Be of the valve portion 20Ba abuts against the raised portion 10Baa, which functions as a stopper, and the rotation of the valve portion 20Ba and the rotation of the magnet rotor 32B are restricted. Therefore, the valve portion 20Ba is restricted from moving beyond the position where the valve is open or the position where the valve is closed (or a minimum opening), allowing for stable and reliable positioning with reproducibility.

[0093] The stepping motor 30B includes a case 31B, a magnet rotor 32B, and a stator coil 33B.

[0094] The case 31B is made of a metal such as stainless steel and is formed in a generally cylindrical shape with a closed upper end, defining the back pressure chamber 16 that houses the valve body 20B and the magnet rotor 32B. The lower open end of the case 31B is airtightly fixed to the upper end of the bowl-shaped member 10Ba by welding or the like.

[0095] The magnet rotor 32B integrally comprises a cylindrical magnet portion 34B whose outer periphery is magnetized with multiple poles, and a hub 35B connected via spokes to the inner periphery of the magnet portion 34B. The magnet rotor 32B is fixed to the valve element 20B by abutting one end of the hub 35B against the step portion 20Bd and clamping the other end of the hub 35B with a retaining ring 17 so as to be biased in the direction of the axis L. In this way, the rotor portion integrally includes the magnet rotor 32B and the valve element 20B and is provided within the case 31B so as to be rotatable about the axis L.

[0096] The stator coil 33B is disposed on the outer peripheral surface of the case 31B, and when a pulse signal is given to the stator coil 33B, the magnet rotor 32B is rotated in accordance with the number of pulses.

[0097] In this way, when the magnet rotor 32B rotates, the valve portion 20Ba rotates together with the magnet rotor 32B relative to the valve port 11Ba, changing the opening degree between the flow path portion 15B and the valve port 11Ba, and controlling the flow rate of the fluid flowing from the first joint pipe 1B to the second joint pipe 2B (or from the second joint pipe 2B to the first joint pipe 1B), as will be described in detail later.

[0098] The support member 40B includes a spring receiving portion 41 that is rotatably arranged in contact with the case 31B, and a biasing spring 42 that is sandwiched between the spring receiving portion 41 and the valve body 20B and biases the valve body 20B toward one end.

[0099] <Operation of the motor-operated valve> The operation of the motor-operated valve 100g will be described using Figure 7. Here, the motor-operated valve 100g will be described as being used in a refrigerant circuit, but this is not limited to this. In addition, in the motor-operated valve 100g, the first joint pipe 1B will be described as being connected to the high-pressure (primary pressure) side, and the second joint pipe 2B will be described as being connected to the low-pressure (secondary pressure) side (solid line in Figure 7(a)). Note that the same explanation can be given for the case where the second joint pipe 2B is connected to the high-pressure side and the first joint pipe 1B is connected to the low-pressure side (dashed line in Figure 7(a)), which is the opposite direction of flow, and therefore this will be omitted here.

[0100] First, as shown in FIG. 7(b), the valve portion 20Ba is rotated counterclockwise (in the direction of the arrow) by the magnet rotor 32B. This causes the protrusion 20Be of the valve portion 20Ba to abut against the raised portion 10Baa of the bowl-shaped member 10Ba, restricting the rotation of the valve portion 20Ba and the magnet rotor 32B. At this time, the flow path portion 15B faces the valve port 11Ba, resulting in an open valve. Therefore, fluid flows from the first port 1Ba on the high-pressure side to the second port 2Ba on the low-pressure side, as indicated by the solid arrows in FIG. 7(a). To prevent pressure loss in the fluid path, the flow path areas of the flow path portion 15B and the internal flow path 14, located before and after the valve port 11Ba, are set larger than the flow path area of ​​the valve port 11Ba.

[0101] Next, although not shown, the valve portion 20Ba is rotated clockwise by the magnet rotor 32B, causing the protrusion 20Be of the valve portion 20Ba to abut against the raised portion 10Baa of the bowl-shaped member 10Ba, restricting the rotation of the valve portion 20Ba and also restricting the rotation of the magnet rotor 32B. At this time, the flow path portion 15B faces the valve seat 11Bb, and the valve port 11Ba faces the seal portion 20Baa, resulting in a valve-closed state. This closes the flow path from the first port 1Ba on the high-pressure side to the second port 2Ba on the low-pressure side.

[0102] The flow path section 15B in the second embodiment has a shape that combines a substantially fan-shaped shape with a semicircular shape that is eccentric with respect to the axis L when viewed in the direction of the axis L. Therefore, in the second embodiment, when the flow path section 15B rotates with respect to the valve port 11Ba and transitions from one of the valve open state (see FIG. 7(b)) and the valve closed state (not shown) to the other, the flow path area decreases abruptly immediately after the transition and then gradually decreases, or the flow path area changes gradually and then rapidly increases. In this way, the motor-operated valve 100g in the second embodiment is capable of flow rate control by a combination of abrupt and gradual changes in the flow path area, and therefore can be used, for example, as an on-off valve that has the added function of a flow rate adjustment valve.

[0103] Although the flow path section 15B in the second embodiment has a shape that combines a substantially fan-shaped shape with a semicircular shape that is eccentric with respect to the axis L when viewed from the direction of the axis L, the shape is not limited thereto. For example, when the flow path section 15B in the second embodiment has a substantially fan-shaped shape when viewed from the direction of the axis L, in the motor-operated valve 100g, the flow path section 15B rotates relative to the valve port 11Ba. When the flow path section 15B transitions from one of the valve-open state and the valve-closed state to the other, the flow path area rapidly decreases or increases immediately after the transition. This allows the motor-operated valve 100g to be used, for example, as an on-off valve. Furthermore, when the flow path section 15B in the second embodiment has a semicircular shape that is eccentric with respect to the axis L when viewed from the direction of the axis L, in the motor-operated valve 100g, the flow path section 15B rotates relative to the valve port 11Ba. When the flow path section 15B transitions from one of the valve-open state and the valve-closed state to the other, the flow path area gradually decreases or increases, allowing for fine flow rate control. This allows the motor-operated valve 100g to be used, for example, as a flow rate adjustment valve.

[0104] Here, in the electric valve 100g of the second embodiment, similarly to the first embodiment, in order to solve the conventional problem (increased sliding resistance), a first measure (improving the material of the sliding part) is taken, and then a second measure (heat-resistant means for the sliding part) and a third measure (cooling means (valve part) for the sliding part) are further taken to address the concerns (melting of the sliding part) and the concerns (dimensional changes of the sliding part).

[0105] <First measure (improving the material of the sliding part)> In the electric valve 100g of the second embodiment, as in the first embodiment, the first measure (improving the material of the sliding part) is adopted, that is, the materials constituting the sliding part (valve body 20B and guide member 11B) are devised and both are made of resin material, thereby solving the conventional problem (increased sliding resistance).

[0106] <Second measure (heat resistance of sliding parts)> In the electric valve 100g in the second embodiment, similar to the first embodiment, the second countermeasure (heat-resistant means for the sliding part) is adopted. That is, the resin materials of the valve body 20B and the guide member 11B are made of polyphenylene sulfide (PPS) added with polytetrafluoroethylene (PTFE). Preferably, in addition to polytetrafluoroethylene (PTFE), PPS added with glass fiber or carbon fiber as a reinforcing agent is used to eliminate the concern (melting of the sliding part).

[0107] <Regarding the third countermeasure (cooling means for the sliding part (valve part))> In the electric valve 100g in the second embodiment, similar to the first embodiment, by adopting the third countermeasure (cooling means for the sliding part (valve part)), the concern (dimensional change of the sliding part) is eliminated. The following is a specific explanation of the third countermeasure (cooling means for the sliding part (valve part)).

[0108] As shown in FIG. 7(c), the electric valve 100g in the second embodiment has a radial support means for supporting the valve body 20B in the radial direction by a slidable engagement between the bottomed cylindrical part 20Bb on one end side and the guide part 11Bd and the reduced-diameter part 11Bc. Here, as the third countermeasure (cooling means for the sliding part (valve part)) of the electric valve 100g in the second embodiment, the radial clearance G1' (radial clearance) adjacent to the valve part 20Ba on one end side is set smaller (G1' < G2') than the radial clearance G2' on the other end side. Specifically, in the radial support means, as shown in FIG. 7(c), the radial clearance G1' formed between the bottomed cylindrical part 20Bb having the valve part 20Ba on one end side and the guide part 11Bd is set smaller than the radial clearance G2' formed between the bottomed cylindrical part 20Bb on one end side and the reduced-diameter part 11Bc. Thus, when the third countermeasure (cooling means for the sliding part (valve part)) is adopted in the electric valve 100g of the second embodiment, the substantial sliding part is composed of the bottomed cylindrical part 20Bb having the valve part 20Ba on one end side and the guide part 11Bd.

[0109] As in the first embodiment, when the fluid flows into the internal flow path 14 via the flow path portion 15B and the valve port 11Ba, it expands (decompresses) and becomes cold (e.g., approximately −10 to 20°C). Therefore, when this cold fluid is introduced into the internal flow path 14 of the valve element 20B in the valve-open state, the radial support means located on one end side of the valve element 20B, in particular, is actively cooled from the inside, thereby eliminating a concern (dimensional changes in the sliding portion) and reliably improving the operability and durability of the sliding portion. Furthermore, since the sliding area of ​​the radial support means can be relatively small and sliding resistance can be reduced, the operability and durability of the sliding portion can be further improved. Furthermore, since the one-end radial gap G1′ is relatively small, the sealing performance of the valve portion 20Ba in the valve-closed state is improved, and valve leakage can be suppressed.

[0110] As described above, the motor-operated valve 100g of the second embodiment can solve the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding part by adopting the first measure (improving the material of the sliding part). Also, by adopting the second measure (heat-resistant means for the sliding part) and solving the concern (melting of the sliding part), and by adopting the third measure (cooling means (valve part) for the sliding part) and solving the concern (dimensional change of the sliding part), the operability and durability of the sliding part can be further improved.

[0111] In the electric valve 100g of the second embodiment, the first measure (improving the material of the sliding part), the second measure (heat-resistant means for the sliding part), and the third measure (cooling means for the sliding part (valve part)) are adopted, but this is not limited to this. For example, the first measure (improving the material of the sliding part) may be adopted, and then the second measure (heat-resistant means for the sliding part) or the third measure (cooling means for the sliding part (valve part)) may be adopted.

[0112] (Modification of the stopper portion of the second embodiment) A modified stopper portion of the second embodiment will be described using Figure 8. The connection mode of the first joint pipe 1B' in the modified stopper portion of the second embodiment differs from that of the second embodiment in that the first joint pipe 1B' extending in a direction perpendicular to the axis L is disposed at a position where the first joint pipe 1B' functions as a stopper portion for the valve portion 20Ba, and the raised portion 10Baa is omitted. However, the other configurations are the same as those of the second embodiment. Here, the same configurations are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0113] Specifically, the first joint pipe 1B' is disposed in the bowl-shaped member 10Ba' at a position overlapping the protrusion 20Be when viewed from a direction perpendicular to the axis L, as shown in FIG. 8(a), and at a position interfering with the rotating protrusion 20Be when viewed from the direction of the axis L, as shown in FIG. 8(b). The first joint pipe 1B' contacts the rotating protrusion 20Be, restricting the rotation angle to a desired value, thereby enabling stable, reliable positioning with reproducibility. Because the first joint pipe 1B' thus functions as a stopper for the valve portion 20Ba, the protrusion 10Baa can be omitted, resulting in cost reduction.

[0114] As described above, the motor-operated valve 100h in the modified stopper portion of the second embodiment, like the second embodiment, can solve the conventional problem (increased sliding resistance) and improve the operability and durability of the sliding portion by adopting the first measure (improving the material of the sliding portion). Also, by adopting the second measure (heat-resistant means for the sliding portion) and / or the third measure (cooling means (valve portion) for the sliding portion), the concern (melting of the sliding portion) and / or the concern (dimensional change of the sliding portion) can be solved, and the operability and durability of the sliding portion can be further improved.

[0115] <About the refrigeration cycle system> The refrigeration cycle system of the present invention will be described with reference to Figure 9. The refrigeration cycle system includes an expansion valve 100 using the motor-operated valves 100a to 100h of the first and second embodiments, an outdoor heat exchanger 200 mounted in an outdoor unit, an indoor heat exchanger 300 mounted in an indoor unit, a flow path switching valve 400 constituting a four-way valve, and a compressor 500. The expansion valve 100, the outdoor heat exchanger 200, the indoor heat exchanger 300, the flow path switching valve 400, and the compressor 500 are connected to each other by conduits to form a heat pump type refrigeration cycle. Note that an accumulator, a pressure sensor, a temperature sensor, etc. are not shown in the figure.

[0116] The flow path of the refrigeration cycle can be switched between two paths, one for cooling operation and the other for heating operation, by the flow path switching valve 400. During cooling operation (see the solid arrow in the figure), the refrigerant compressed by the compressor 500 is circulated from the flow path switching valve 400 through the outdoor heat exchanger 200, the expansion valve 100, the indoor heat exchanger 300, the flow path switching valve 400, and then the compressor 500, with the outdoor heat exchanger 200 functioning as a condenser and the indoor heat exchanger 300 functioning as an evaporator.

[0117] On the other hand, during heating operation (see the dashed arrow in the figure), the refrigerant compressed by the compressor 500 is circulated in the following order: from the flow path switching valve 400 to the indoor heat exchanger 300, the expansion valve 100, the outdoor heat exchanger 200, the flow path switching valve 400, and then to the compressor 500, with the indoor heat exchanger 300 functioning as a condenser and the outdoor heat exchanger 200 functioning as an evaporator. Thus, the expansion valve 100 decompresses and expands the liquid refrigerant flowing in from the outdoor heat exchanger 200 during cooling operation, or the liquid refrigerant flowing in from the indoor heat exchanger 300 during heating operation, and can further control the flow rate of the refrigerant.

[0118] The present invention is not limited to the first and second embodiments, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention. For example, the first and second embodiments illustrate motor-operated valves 100a to 100h used in air conditioners such as home air conditioners, but the motor-operated valves of the present invention are not limited to home air conditioners, but may also be used in commercial air conditioners, and are not limited to air conditioners, but can also be applied to various types of refrigerators, etc.

[0119] <Other> It goes without saying that the motor-operated valves 100a to 100h of the present embodiment are applicable not only to the refrigeration cycle illustrated as an example, but also to any fluid device and fluid circuit. Furthermore, the present invention is not limited to the above-described aspects, embodiments, and modified examples, and can be appropriately changed or modified within the scope of the technical concept of the present invention. [Explanation of symbols]

[0120] 100a~100h Electric valve 1,1B,1B' First joint pipe 1a, 1Ba, 1Ba' 1st port 2,2',2B Second joint pipe 2a, 2Ba 2nd port 10A, 10A', 10A'', 10B valve body 10,10',10Ba,10Ba' Bowl-shaped member 10Baa ridge 11, 11', 11B Guide member 11a, 11Ba valve port 11b,11Bb Valve seat 11ca small diameter guide section 11cb Large diameter guide section 11e Step 11g Drawer section 11h,11h' Other end 11Bc Reduced diameter part 11Bd Guide part 11Be Support part 12,12' lower lid 12a Communication hole 13 Flow path chamber 14 Internal flow path 15,15'',15''',15B flow path section 16 Back pressure chamber 17 Retaining ring 18 Connecting Room 20, 20', 20'', 20B valve body 20a,20a'',20a''',20Ba valve part 20aa, 20Baa seal part 20c,20Bc Other end side bottomed cylindrical part 20g Small diameter guide shaft 20h Large diameter guide shaft 20i,20i' Stepped part on one end 20k disc part 20ka Other end stepped section 20kb,20Be protrusion 20l shaft hole (equalizing pressure hole) 20m through hole (equalizing hole) 20Bb One end side bottomed cylindrical part 20Bba other end 20Bd multi-layered section 20Bf Annular groove 20Bg flange 30,30B stepping motor 31,31B Case 32,32B magnet rotor 33, 33B Stator coil 34, 34B Magnet part 35,35B hub 40, 40B Support member 41 Spring holder 42 bias spring 43 Bush 100 Expansion valve 200 Outdoor heat exchanger 300 Indoor heat exchanger 400 Flow path switching valve 500 compressor G1, G1' Radial clearance on one end G2, G2' Radial clearance on the other end L axis

Claims

1. a valve body having a valve portion provided on one end side thereof, and a rotor portion having a rotor that rotates integrally with the valve body; a valve body including a flow path chamber that accommodates the valve portion, a valve seat that faces the valve portion in a radial direction, and a valve port that extends in a radial direction and is capable of communicating with the flow path chamber; a case connected to the valve body and defining a back pressure chamber of the rotor portion; Equipped with the valve body has a first port directly communicating with the flow path chamber, a second port communicating with the valve port, and a guide member that supports the valve element, which is provided along an axis, in the axial direction and guides it in a circumferential direction, the valve portion has a seal portion that closes the valve port and a flow path portion that can communicate with the valve port, the rotation of the rotor changes the state of communication between the valve port and the flow path portion, thereby controlling the flow rate of the fluid flowing through the valve port; The valve body and the guide member constitute a sliding portion, and are made of a resin material.

2. 2. The motor-operated valve according to claim 1, wherein the resin material is PPS with PTFE added thereto.

3. 3. The motor-operated valve according to claim 2, wherein the resin material contains glass fiber or carbon fiber as a reinforcing agent.

4. a radial support means for supporting the valve body in the radial direction, the radial support means being set in a predetermined radial gap between the valve body and the guide member, the sliding portion; 2. The motor-operated valve according to claim 1, wherein the radial support means has a one-end radial gap adjacent to the valve portion and an other-end radial gap adjacent to the other end side of the one-end radial gap, and the one-end radial gap is set smaller than the other-end radial gap.

5. The valve body has, in order from one end side to the other end side, a small diameter guide shaft portion having the valve portion on one end side and a large diameter guide shaft portion, The guide member has a small diameter guide portion and a large diameter guide portion in this order from one end side to the other end side, 5. The motor-operated valve according to claim 4, wherein the one-end radial gap between the small-diameter guide shaft portion and the small-diameter guide portion is set smaller than the other-end radial gap between the large-diameter guide shaft portion and the large-diameter guide portion.

6. The valve valve further includes an axial support means for supporting the valve in the axial direction by engaging the axially opposing surfaces of the valve body and the guide member, the sliding portion being the valve body, in the axial direction. the first port communicates with the valve port via the flow path chamber; 6. The motor-operated valve according to claim 5, wherein the valve element extends along an axis and has a pressure equalizing hole that constantly communicates the second port with the back pressure chamber.

7. the valve body has an annular step portion at the boundary between the small diameter guide shaft portion and the large diameter guide shaft portion, the guide member has an annular step portion at a boundary between the small diameter guide portion and the large diameter guide portion, 7. The motor-operated valve according to claim 6, wherein the axial support means engages the step portion of the valve body and the step portion of the guide member with each other.

8. A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, wherein the motor-operated valve according to any one of claims 1 to 7 is used as the expansion valve.

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