Expansion valve

Abstract

To provide an expansion valve that can further enhance the vibration damping effect of the valve body while suppressing cost increases. [Solution] The expansion valve comprises a valve body having a valve chamber and a valve seat, a valve element disposed in the valve chamber, and a biasing device that biases the valve element toward the valve seat. The biasing device comprises a valve element support connected to the valve element, a coil spring that generates a force to bias the valve element, a vibration-damping spring that displaces together with the valve element support, and a regulating member disposed between the coil spring and the vibration-damping spring. The vibration-damping spring has a fixed portion sandwiched between the valve element support and the regulating member, and a plurality of legs extending from the fixed portion. The legs have a bent portion connected to the fixed portion and a contact portion that abuts against the inner wall of the valve chamber. The regulating member is formed so that the bent portion can make contact.

Description

Technical Field

[0001] The present invention relates to an expansion valve.

Background Art

[0002] Conventionally, in a refrigeration cycle used in, for example, an air conditioner mounted on an automobile, a temperature-sensitive thermostatic expansion valve that adjusts the amount of refrigerant passing through according to temperature is used. In such a thermostatic expansion valve, a valve body is driven via an operating rod by the pressure of an operating gas enclosed in a power element.

[0003] In the expansion valve of Patent Document 1, a first anti-vibration spring provided in a valve chamber of a valve body to prevent vibration of the valve body and a second anti-vibration spring that abuts on an operating rod for driving the valve body to prevent vibration of the valve body are provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The first anti-vibration spring of the expansion valve includes a base portion and leg portions that extend radially from the outer peripheral side of the base portion. The leg portions have a bent portion and a protrusion near the tip. By utilizing the elastic force of the leg portions, the protrusion is pressed against the inner wall of the valve chamber, and the protrusion slides with respect to the inner wall as the valve body moves up and down, thereby exerting an anti-vibration effect on the valve body.

[0006] In the legs of the first vibration-damping spring of the expansion valve described above, elastic deformation occurs due to the reaction force received by the projection from the inner wall of the valve chamber, thereby generating internal stress. Since this internal stress is concentrated at the bent portion of the leg, the stress at the bent portion is generally higher than at other parts. Therefore, when designing the first vibration-damping spring, it is necessary to ensure that the strength of the bent portion does not fall below the allowable value.

[0007] In this case, depending on the specifications of the expansion valve, it may be desirable to further improve the vibration damping effect of the valve body. In such cases, increasing the pressing force applied from the projection to the inner wall of the valve chamber is effective, and this can be achieved, for example, by increasing the amount of elastic deformation of the leg during assembly. However, this may cause the stress at the bent portion to exceed the allowable value. As an alternative, one option is to form the first vibration damping spring from a material with a thicker plate thickness, but this has the problem of increasing costs and the weight of the expansion valve.

[0008] Therefore, the present invention aims to provide an expansion valve that can further enhance the vibration damping effect of the valve body while suppressing an increase in costs. [Means for solving the problem]

[0009] To achieve the above objective, the expansion valve according to the present invention is A valve body comprising a valve chamber and a valve seat, A valve body arranged in the valve chamber, The valve body is biased toward the valve seat by a biasing device, The biasing device comprises a valve support connected to the valve body, a coil spring that generates a force to bias the valve body, a vibration-damping spring that displaces together with the valve support, and a regulating member disposed between the coil spring and the vibration-damping spring. The vibration-damping spring has a fixed portion sandwiched between the valve support and the regulating member, and a plurality of legs extending from the fixed portion. The leg portion has a bent portion connected to the fixed portion and a contact portion that abuts against the inner wall of the valve chamber. The restricting member is characterized in that the bent portion is formed to be in contact with other objects. [Effects of the Invention]

[0010] The present invention provides an expansion valve that can further enhance the vibration damping effect of the valve body while suppressing an increase in costs. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic cross-sectional view illustrating an example in which the expansion valve in the first embodiment is applied to a refrigerant circulation system. [Figure 2] Figure 2 is a cross-sectional view showing the valve body, valve body support, vibration damping spring, and regulating member assembled together. [Figure 3] Figure 3 is a bottom view of the configuration shown in Figure 2, viewed in the X direction. [Figure 4] Figure 4 is a cross-sectional view showing the valve body, valve body support, vibration damping spring, and regulating member in a disassembled state. [Figure 5] Figure 5 is a perspective view of the vibration-damping spring. [Figure 6] Figure 6 is a plan view of a coil spring seen from above. [Figure 7] Figure 7 is a schematic cross-sectional view showing the assembly of the valve body support, vibration damping spring, and regulating member to the expansion valve, illustrating the deformation of the vibration damping spring in stages. [Figure 8] Figure 8 is a cross-sectional view showing an enlarged portion of the configuration in Figure 7. [Figure 9] Figure 9(a) is a graph showing the relationship between leg displacement and maximum stress, and Figure 9(b) is a graph showing the relationship between leg displacement and generated load. [Figure 10] Figure 10 is similar to Figure 8(b), which shows the first modified example. [Figure 11] Figure 11 is similar to Figure 8(b), which shows a second modified example. [Figure 12] Figure 12 is similar to Figure 8(b), showing a third modified example. [Figure 13]FIG. 13 is a cross-sectional view showing a state in which a valve body, a valve body support, a vibration isolator spring, and a regulating member according to a second embodiment are assembled. [Figure 14] FIG. 14 is a bottom view of the configuration of FIG. 13 as viewed in the X direction. [Figure 15] FIG. 15 is a bottom view of the valve body support as viewed in the X direction of FIG. 13. [Figure 16] FIG. 16 is a bottom view of the vibration isolator spring as viewed in the X direction of FIG. 13. [Figure 17] FIG. 17 is a bottom view of the regulating member as viewed in the X direction of FIG. 13. [Figure 18] FIG. 18 is a cross-sectional view showing a state in which a valve body, a valve body support, a vibration isolator spring, and a regulating member according to a third embodiment are assembled. [Figure 19] FIG. 19 is a bottom view of the configuration of FIG. 18 as viewed in the X direction. [Figure 20] FIG. 20 is a bottom view of the valve body support as viewed in the X direction of FIG. 18. [Figure 21] FIG. 21 is a bottom view of the vibration isolator spring as viewed in the X direction of FIG. 18. [Figure 22] FIG. 22 is a bottom view of the regulating member as viewed in the X direction of FIG. 18. [Figure 23] FIG. 23 is a cross-sectional view showing a state in which a valve body, a valve body support, a vibration isolator spring, and a regulating member according to a fourth embodiment are assembled. [Figure 24] FIG. 24 is a bottom view of the configuration of FIG. 23 as viewed in the X direction. [Figure 25] FIG. 25 is a bottom view of the regulating member as viewed in the X direction of FIG. 23. [Figure 26] FIG. 26 is an enlarged cross-sectional view showing a main part of an expansion valve according to a fifth embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0012] (Definition of Direction) In this specification, the direction from the valve body 3 toward the biasing device 4 is defined as "downward," and the direction from the biasing device 4 toward the valve body 3 is defined as "upward." Therefore, in this specification, regardless of the orientation of the expansion valve 1, the direction from the valve body 3 toward the biasing device 4 is referred to as "downward."

[0013] (First Embodiment) The expansion valve 1 in the first embodiment will be described below. Figure 1 is a schematic cross-sectional view illustrating an example of the expansion valve 1 in this embodiment being applied to a refrigerant circulation system 100. Figure 2 is a cross-sectional view showing the valve body 3, valve body support 42, vibration damping spring 44, and regulating member 45 assembled. Figure 3 is a bottom view of the configuration in Figure 2, viewed in the X direction. Figure 4 is a cross-sectional view showing the valve body 3, valve body support 42, vibration damping spring 44, and regulating member 45 disassembled. Figure 5 is a perspective view of the vibration damping spring 44. Figure 6 is a plan view of the coil spring 41 viewed from above. The center line of the operating rod 5 of the expansion valve 1 is defined as axis L.

[0014] In this embodiment, the expansion valve 1 is fluidly connected to the compressor 101, the condenser 102, and the evaporator 103.

[0015] As shown in Figure 1, the expansion valve 1 comprises a valve body 2 having a valve chamber VC, a spherical valve body 3, a biasing device 4, an operating rod 5, and a power element 8.

[0016] The valve body 2 includes a valve chamber VC, a first flow path 21, a second flow path 22, an intermediate chamber 221, and a return flow path 23. The first flow path 21 is a supply-side flow path, and refrigerant is supplied to the valve chamber VC via this flow path. The second flow path 22 is a discharge-side flow path, and the fluid in the valve chamber VC is discharged outside the expansion valve via the orifice hole 27, the intermediate chamber 221, and the discharge-side flow path.

[0017] The first flow path 21 and the valve chamber VC are connected by a smaller diameter connecting passage (also called an introduction passage) 21a than the first flow path 21. The valve chamber VC and the intermediate chamber 221 are connected via the valve seat 20 and the orifice hole 27.

[0018] The operating rod insertion hole 28 formed above the intermediate chamber 221 has the function of guiding the operating rod 5, and the annular recess 29 formed above the operating rod insertion hole 28 has the function of housing the ring spring 6. The ring spring 6 applies a predetermined biasing force by bringing a plurality of spring pieces into contact with the outer circumference of the operating rod 5 along the circumferential direction. The structure of the ring spring 6 is described, for example, in Japanese Patent Application Publication No. 2019-74236.

[0019] The valve body 3 is positioned within the valve chamber VC so as to be able to move toward and away from the valve seat 20. When the valve body 3 is seated on the valve seat 20 of the valve body 2, the flow of refrigerant through the orifice hole 27 is restricted. This state is called the non-communication state. However, even when the valve body 3 is seated on the valve seat 20, a limited amount of refrigerant may still flow. On the other hand, as shown in Figure 1, when the valve body 3 is separated from the valve seat 20, the flow of refrigerant through the orifice hole 27 increases. This state is called the communication state.

[0020] The operating rod 5 is inserted through the orifice hole 27 with a predetermined gap. The lower end of the operating rod 5 is in contact with the upper surface of the valve body 3. The upper end of the operating rod 5 is fitted into the fitting hole 84c of the stopper member 84, which will be described later.

[0021] The actuator rod 5 can press the valve body 3 in the opening direction against the biasing force of the biasing device 4. When the actuator rod 5 moves downward, the valve body 3 separates from the valve seat 20, and the expansion valve 1 opens.

[0022] The biasing device 4 includes a coil spring 41 made by winding a wire spirally, a valve body support 42, a bottomed cylindrical spring receiving member 43, a vibration damping spring 44, and a regulating member 45. The wire forming the coil spring 41 is preferably, for example, circular in cross-section.

[0023] A coil spring 41 is formed by cutting a spiral wire in a direction perpendicular to the center line of the wire's spiral shape. At this time, flat receiving surfaces 41a (Figure 6) are formed at both ends of the coil spring 41 by the cut ends. That is, the end faces of the coil spring 41 are not flat all the way around, but only the receiving surfaces 41a are flat. The receiving surface 41a on the lower end contacts the bottom surface of the spring receiving member 43, and the receiving surface 41a on the upper end contacts the lower surface (flat surface) of the regulating member 45. As a result, the regulating member 45 is stably supported by the coil spring 41.

[0024] The spring support member 43, which supports the lower end of the coil spring 41, is screwable onto the valve body 2 and has the function of sealing the valve chamber VC and adjusting the biasing force of the coil spring 41. An O-ring OR with a sealing function is placed between the spring support member 43 and the valve body 2.

[0025] In Figures 2 and 4, the valve support 42 is formed, for example, by forging or machining a metal material, and consists of a circular flange portion 42a and a cylindrical portion 42b having a smaller diameter than the flange portion 42a. The diameter of the flange portion 42a is denoted as φA.

[0026] As shown in Figures 2, 4, and 5, the vibration-damping spring 44 consists of a central base 44a and a plurality (in this case, eight) of legs 44b connected together. The vibration-damping spring 44 can be integrally formed by bending an elastic metal sheet of uniform thickness, such as stainless steel or its alloy, by press forming. Three or more legs 44b spaced equally apart in the circumferential direction are sufficient.

[0027] The central base portion 44a, which constitutes the fixed part, is a substantially annular portion that forms the upper part of the vibration-damping spring 44 and has a circular mounting hole 44c in the center. The inner diameter of the mounting hole 44c is approximately equal to the outer diameter of the cylindrical portion 42b of the valve body support 42. In addition to the central base portion 44a, the upper part 44d of the leg portion 44b may also be included as part of the fixed part.

[0028] The leg portions 44b have a shape that extends radially from the outer circumference of the central base portion 44a and then extends downward. Here, eight leg portions 44b of the same length are provided at equal angular intervals. Each leg portion 44b has an upper portion 44d which is a flat plate shape substantially in the same plane as the central base portion 44a, a bent portion 44g which is curved and connected to the upper portion 44d, a flat side portion 44e which is connected to the bent portion 44g, and a projection (contact portion) 44f formed on the side portion 44e. The bent portion 44g is formed in an arc shape when viewed from the side, with the direction from the root side to the tip side of the leg portion 44b being the vertical direction and the direction perpendicular to the vertical direction and the plate thickness of the leg portion 44b being the horizontal direction. However, the bent portion 44g does not have to be a perfect arc shape, but may be a curved shape formed by connecting multiple arcs. By arbitrarily changing the length and radius of the multiple arcs that are connected, it is possible to form a free-form curved section 44g that is not limited to a perfect arc.

[0029] In a free state where no elastic deformation occurs, it is preferable that the intersection angle between the upper part 44d and the side part 44e is obtuse. As shown in Figure 4, the diameter of the virtual circle inscribed by the boundary between the upper part 44d and the bent part 44g is φB, and it is preferable that φB = φA.

[0030] In the central base portion 44a, a roughly triangular or arc-shaped notch 44k is formed between two adjacent upper portions 44d (Figure 5). Note that the shape of the notch 44k described above is just one example and is not limited to a roughly triangular or arc shape.

[0031] The vertical length of the leg portion 44b can be set to an appropriate length, as long as the lower end of the leg portion 44b does not enter the connecting passage 21a at the lowest point within the range of vertical movement of the vibration-damping spring 44 which moves together with the valve body 3. In particular, it is desirable that the lower end of the leg portion 44b does not reach the connecting passage 21a so as not to obstruct the flow of refrigerant introduced from the connecting passage 21a into the valve chamber VC, and to prevent a decrease in flow rate or the generation of turbulence as a result.

[0032] In Figures 2 and 4, the regulating member 45 is a circular plate that can be formed from, for example, a resin or metal material. The regulating member 45 has a central circular opening 45a, an upper surface 45b, and a lower surface 45c. The inner diameter of the circular opening 45a is approximately equal to the outer diameter of the cylindrical portion 42b of the valve support 42.

[0033] The upper surface 45b has a central plane 45d and a surrounding curved surface (first curved surface) 45f having a radius of curvature R in the cross-section shown in Figures 2 and 4, which includes the center line of the regulating member 45. The radius of curvature R is smaller than the bending radius of the bent portion 44g of the leg portion 44b of the vibration-damping spring 44 in the free state. The surrounding curved surface 45f has a common shape in any cross-section passing through the center line of the regulating member 45. The diameter of the virtual circle inscribed by the boundary between the central plane 45d and the surrounding curved surface 45f is φC, and preferably φC = φB. The lower surface 45c is parallel to the central plane 45d and intersects with the surrounding curved surface 45f.

[0034] When assembling the vibration-damping spring 44, the regulating member 45 is placed on the upper end of the coil spring 41, the vibration-damping spring 44 is placed on the upper surface 45b of the regulating member 45, and the valve body support 42 and valve body 3 are placed on top of it. At this time, the cylindrical portion 42b of the valve body support 42 passes through the circular opening 45a of the regulating member 45 and the mounting hole 44c of the vibration-damping spring 44, reaching the inside of the coil spring 41. As a result, the vibration-damping spring 44 is sandwiched between the regulating member 45 and the valve body support 42.

[0035] According to this embodiment, the upper surfaces of the central base 44a and upper part 44d of the vibration-damping spring 44 are in close contact with the lower surface of the flange 42a of the valve body support 42. Also, the lower surfaces of the central base 44a and upper part 44d are in close contact with the central plane 45d of the regulating member 45. As a result, the vibration-damping spring 44 is held in a stable state by being sandwiched between the valve body support 42 and the regulating member 45.

[0036] Furthermore, the coil spring 41 contacts the vibration-damping spring 44 via the regulating member 45. For example, if the coil spring 41 contacts the vibration-damping spring 44 directly, a gap will be created between the end face of the coil spring 41 other than the receiving surface 41a and the central base 44a of the vibration-damping spring 44. This gap may cause deformation, such as bending, in the portion of the central base 44a facing the gap. As described above, in this embodiment, the regulating member 45 abuts against the vibration-damping spring 44, and the coil spring 41 abuts against the regulating member 45, thus preventing deformation from occurring in the central base 44a.

[0037] Figure 7 is a schematic cross-sectional view showing the assembly of the valve body support 42, vibration damping spring 44, and regulating member 45 to the expansion valve, and Figure 8 is an enlarged cross-sectional view showing a part of the configuration in Figure 7. Figure 9(a) is a graph showing the relationship between the displacement of the leg portion and the maximum stress, and Figure 9(b) is a graph showing the relationship between the displacement of the leg portion and the generated load. In Figures 9(a) and (b), "displacement" refers to the displacement of the projection 44f of the vibration damping spring 44 in a direction perpendicular to the axis L, "maximum stress" refers to the maximum value of the stress acting on the bent portion 44g (here, the apex P1 of the bent portion 44g), and "generated load" refers to the force F in the direction of the displacement of the projection 44f caused by the elastic deformation of the leg portion 44b when the projection 44f is displaced.

[0038] Figures 7(a) and 8(a) show the valve body support 42, vibration damping spring 44, and regulating member 45 before assembly to the expansion valve, with the leg portion 44b in a free state (not elastically deformed). In Figures 7(a) and 8(a), the displacement of the projection portion 44f is set to zero. At this time, as shown in Figures 9(a) and (b), the maximum stress and generated load are also zero.

[0039] Figures 7(b) and 8(b) show the state in which the tips of each leg portion 44b are brought closer together in order to assemble the valve body support 42, vibration damping spring 44, and regulating member 45 to the expansion valve, and as a result the projection 44f is displaced toward the center of the regulating member 45. Until the amount of displacement of the projection 44f approaches X1, the bent portion 44g of the leg portion 44b mainly undergoes elastic deformation, and as a result the maximum stress and generated load also increase linearly in proportion to the amount of displacement (see Figures 9(a) and (b)).

[0040] Until the displacement of the projection 44f reaches X1, the lower surface of the bent portion 44g begins to adhere closely to the surrounding curved surface 45f of the regulating member 45 from the upper part 44d side, and when the displacement of the projection 44f reaches X1, the bent portion 44g adheres closely to the entire surface of the surrounding curved surface 45f. For this reason, even if the displacement of the projection 44f increases thereafter, the maximum stress of the bent portion 44g does not increase and remains approximately constant (see Figure 9(a)), while the side portion 44e of the leg portion 44b begins to undergo mainly elastic deformation, so the rate of increase of the generated load with respect to the displacement of the projection 44f also increases compared to before the displacement X1 was reached (see Figure 9(b)). Here, in the example shown in Figure 8(b), point P2, which is the boundary between the bent portion 44g and the side portion 44e, is located at the outer edge of the lower surface 45c of the regulating member 45. As shown in Figures 7(b) and 8(b), the stress generated in the bent portion 44g when it is in close contact with the surrounding curved surface 45f is less than or equal to the allowable value of the bent portion 44g. In other words, the surrounding curved surface 45f has a shape such that the stress generated in the bent portion 44g is less than or equal to the allowable value. The allowable value is an arbitrarily set value. The allowable value may be, for example, the stress at which plastic deformation occurs in the bent portion 44g. Alternatively, the allowable value may be a predetermined value smaller than the stress at which plastic deformation occurs. Alternatively, the allowable value may be a predetermined stress value greater than the stress at which plastic deformation occurs.

[0041] Figures 7(c) and 8(c) show the valve body support 42, vibration damping spring 44, and regulating member 45 assembled to the expansion valve, with the projection 44f in contact with the inner wall of the valve chamber VC. At this time, the displacement of the projection 44f reaches X2, and the vibration damping spring 44 operates in this state. Until the displacement of the projection 44f increases from X1 to X2, the maximum stress of the bent portion 44g does not increase. Instead, the elastic deformation of the side portion 44e generates stress in the side portion 44e, but it is configured so as not to exceed the maximum stress of the bent portion 44g. This makes it possible to distribute the stress generated in the leg portion 44b.

[0042] If the restricting member 45 were not provided, as shown by the dotted line in Figure 9(a), the maximum stress of the bent portion 44g would continue to increase in proportion to the displacement of the projection 44f, resulting in a maximum stress of σ1 at a displacement of X2. In contrast, by providing the restricting member 45, the maximum stress at a displacement of X2 can be reduced to σ2 (<σ1).

[0043] Furthermore, if the restricting member 45 is not provided, as shown by the dotted line in Figure 9(b), the load generated on the projection 44f increases in proportion to the displacement of the projection 44f. Therefore, the load generated becomes L1 for a displacement of X2, whereas by providing the restricting member 45, the load generated can be increased to L2 (>L1) for a displacement of X2. This makes it possible to enhance the vibration isolation function without changing the shape or material of the vibration isolation spring 44.

[0044] After assembling the valve body 3, valve body support 42, vibration damping spring 44, regulating member 45, and coil spring 41 in this manner, the valve body 3, valve body support 42, vibration damping spring 44, vibration damping member 45, and coil spring 41 are attached to the spring receiving member 43, and then inserted into the valve chamber VC of the valve body 2. The biasing device 4 can then be installed on the valve body 2 by screwing the spring receiving member 43 onto the valve body 2. At this time, as shown in Figure 1, an O-ring OR with a sealing function is placed between the spring receiving member 43 and the valve body 2.

[0045] Next, the power element 8 will be described. In Figure 1, the power element 8 is attached to a recess 2a provided at the top of the valve body 2. The recess 2a communicates with the return passage 23 inside the valve body 2 through a communication hole 2b, through which the refrigerant from the evaporator 103 passes.

[0046] The power element 8 includes a plug 81, an upper cover member 82, a diaphragm 83, a stopper member 84, and a receiving member 86.

[0047] A hole 82a is formed at the top of the upper lid member 82, and it can be sealed with a plug 81.

[0048] The diaphragm 83 is made of a thin plate material with multiple concentric circular indentations formed on it.

[0049] The stopper member 84 has a disc portion and a cylindrical portion coaxially connected to the lower surface of the disc portion, and a fitting hole 84c is formed in the center of the lower end of the cylindrical portion.

[0050] The receiving member 86 has a flange portion having an outer diameter approximately the same as that of the upper cover member 82, and a hollow cylindrical portion connected to the lower end of the flange portion, with a male thread 86c formed on the outer circumference of the hollow cylindrical portion.

[0051] During the assembly of the power element 8, the outer periphery of the upper cover member 82, the diaphragm 83, and the flange portion of the receiving member 86 are first overlapped, and these outer periphery portions are then integrated by circumferential welding, such as TIG welding, laser welding, or plasma welding.

[0052] Next, after sealing the working gas into the space enclosed by the upper cover member 82 and the diaphragm 83 (called the pressure working chamber PO) through the hole 82a formed in the upper cover member 82, the hole 82a is sealed with a plug 81, and the plug 81 is then fixed to the upper cover member 82 using projection welding or the like.

[0053] At this time, the working gas sealed in the pressure working chamber PO causes the diaphragm 83 to be subjected to pressure in a way that causes it to protrude toward the receiving member 86, and so it is supported by contacting the upper surface of the stopper member 84 located in the lower space LS surrounded by the diaphragm 83 and the receiving member 86. Furthermore, since the disc portion of the stopper member 84 is held by the receiving member 86, the stopper member 84 will not come out of the power element 8.

[0054] When assembling the power element 8 to the valve body 2, with the upper end of the operating rod 5 fitted into the fitting hole 84c of the stopper member 84, the operating rod 5 is inserted into the valve body 2 while passing through the ring spring 6 assembled to the valve body 2, and the lower end is brought into contact with the valve body 3. Furthermore, the male thread 86c of the receiving member 86 is screwed into the female thread 2c of the recess 2a of the valve body 2 and screwed in to fix the power element 8 to the valve body 2. In this state, the lower space LS of the power element 8 is in communication with the return passage 23.

[0055] A packing PK is interposed between the assembled power element 8 and the valve body 2, sealing the space within the recess 2a that connects to the lower space LS, thereby preventing external leakage of refrigerant from the recess 2a. In this state, the lower space LS of the power element 8 is in communication with the return passage 23 through a communication hole 2b formed between the recess 2a and the return passage 23.

[0056] (Operation of the expansion valve) Referring to Figure 1, an example of the operation of the expansion valve 1 will be explained. The refrigerant pressurized by the compressor 101 is liquefied in the condenser 102 and sent to the expansion valve 1. The refrigerant that has been adiabatically expanded in the expansion valve 1 is then sent to the evaporator 103, where it undergoes heat exchange with the air flowing around it. The refrigerant returning from the evaporator 103 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return passage 23).

[0057] The expansion valve 1 is supplied with high-pressure refrigerant from the condenser 102. More specifically, the high-pressure refrigerant from the condenser 102 is supplied to the valve chamber VC via the first flow path 21.

[0058] When the valve body 3 is seated on the valve seat 20 (in a non-communicating state), the flow rate of refrigerant sent from the valve chamber VC to the evaporator 103 through the valve seat 20, orifice hole 27, intermediate chamber 221, and second flow path 22 is restricted. On the other hand, when the valve body 3 is separated from the valve seat 20 (in a communicative state), the flow rate of refrigerant sent from the valve chamber VC to the evaporator 103 through the orifice hole 27, intermediate chamber 221, and second flow path 22, passing between the outer circumference of the regulating member 45 and the inner wall of the valve chamber VC, is increased. Switching between the closed and open states of the expansion valve 1 is performed by an operating rod 5 connected to the power element 8 via a stopper member 84.

[0059] In Figure 1, the power element 8 is provided with a pressure-operated chamber PO and a lower space LS, separated by a diaphragm 83. Therefore, when the pressure of the working gas in the pressure-operated chamber PO decreases, the diaphragm 83 rises, causing the stopper member 84 and the operating rod 5 to move upward in accordance with the biasing force of the coil spring 41.

[0060] On the other hand, when the pressure of the working gas in the pressure working chamber PO increases, the diaphragm 83 and the stopper member 84 are pressed downwards, causing the operating rod 5 to move downwards. Furthermore, the refrigerant of the refrigerant circulation system 100 can pass through the gap between the stopper member 84 and the receiving member 86 to the lower space LS of the power element 8. Therefore, the volume of the working gas in the pressure working chamber PO changes according to the temperature and pressure of the refrigerant flowing through the return passage 23, and the operating rod 5 is driven. In other words, in the expansion valve 1 shown in Figure 1, the amount of refrigerant supplied from the expansion valve 1 to the evaporator 103 is automatically adjusted according to the temperature and pressure of the refrigerant returning from the evaporator 103 to the expansion valve 1.

[0061] Furthermore, according to this embodiment, when the projection 44f of the leg portion 44b of the vibration-damping spring 44 comes into contact with the inner wall of the valve chamber VC, the leg portion 44b elastically deforms, and the elastic force of the leg portion 44b presses the projection 44f toward the inner wall of the valve chamber VC with a predetermined force, it becomes possible to generate sliding resistance in accordance with the movement of the valve body 3. As a result, vibrations of the valve body 3 and the operating rod 5 can be suppressed.

[0062] The vibration-damping spring 44 is sandwiched between the valve body support 42 and the regulating member 45, holding it in a stable state and suppressing tilting of the vibration-damping spring 44.

[0063] Furthermore, since all the legs 44b of the vibration-damping spring 44 elastically deform with the outer edge of the lower surface 45c of the regulating member 45 as a fulcrum, the elastic deformation of each leg 44b becomes uniform. Therefore, the biasing force applied from the projection 44f of the vibration-damping spring 44 to the inner wall of the valve chamber VC is almost uniform in the circumferential direction, so that the valve body 3 and valve body support 42 are stably supported, and the vibration-damping function of the vibration-damping spring 44 that suppresses vibration of the valve body 3 is also stabilized.

[0064] Furthermore, since the vibration-damping spring 44 is in contact with the inner wall above the connection passage 21a in the valve chamber VC, the leg portion 44b does not interfere with the connection passage 21a, thereby suppressing the generation of turbulence in the refrigerant introduced from the connection passage 21a into the valve chamber VC, and keeping the noise of the refrigerant passing through low.

[0065] According to this embodiment, by providing the regulating member 45, the stress on the vibration-damping spring 44 can be distributed, and the vibration-damping effect of the valve body 3 can be further enhanced at a low cost.

[0066] (First variation) Figure 10 is similar to Figure 8(b) in that it shows the first modified example. In this modified example, only the configuration of the restricting member 45A differs from that of the first embodiment; the other configurations are the same as in the first embodiment, so redundant explanations are omitted. The restricting member 45A in this modified example can be used in place of the restricting member 45 of the first embodiment.

[0067] The regulating member 45A has a central circular opening (not shown in FIG. 10), an upper surface 45b, and a lower surface 45Ac. The upper surface 45b has a central plane 45d and a peripheral curved surface 45f having a radius of curvature R in the cross-section of FIG. 10. The lower surface 45Ac has a lower plane 45Ag and a lower curved surface (second curved surface) 45Ah connecting between the lower plane 45Ag and the peripheral curved surface 45f. In the cross-section shown in FIG. 10 including the center line of the regulating member 45A, the lower curved surface 45Ah has a radius of curvature r (<R). The peripheral curved surface 45f and the lower curved surface 45Ah are smoothly connected and have a common shape in any cross-section passing through the center line of the regulating member 45A.

[0068] In the first embodiment, at the point P2 shown in FIG. 8, since the leg portion 44b abuts against the edge where the peripheral curved surface 45f of the regulating member 45 and the lower surface 45c intersect, stress concentration may occur at the point P2 and the stress of the leg portion 44b may increase. On the other hand, according to this modification, since the lower curved surface 45Ah is formed on the lower surface 45Ac, the stress concentration is alleviated when the leg portion 44b abuts against the lower curved surface 45Ah, and an increase in the stress of the leg portion 44b can be suppressed. In the above example, the lower curved surface 45Ah is formed such that the leg portion 44b abuts thereon even in the valve closing state, that is, even when no vibration occurs in the valve body 3 and the leg portion 44b does not vibrate or bend. In other examples, the leg portion 44b may be configured to abut only against the peripheral curved surface 45f in the valve closing state and against the lower curved surface 45Ah when the leg portion 44b vibrates or bends in the valve opening state or the like. In other words, the lower curved surface 45Ah may be formed such that the leg portion 44b abuts thereon when the leg portion 44b is deformed or bent. Thus, in a state where the protrusion (contact portion) 44f of the vibration isolator 44 abuts against the inner wall of the valve chamber VC, the leg portion 44b can abut against the lower curved surface 45Ah.

[0069] (Second modification) Figure 11 is similar to Figure 8(b) in that it shows a second modified example. In this modified example, only the configuration of the restricting member 45B differs from that of the first embodiment; all other configurations are the same as in the first embodiment, so redundant explanations are omitted. The restricting member 45B in this modified example can be used in place of the restricting member 45 of the first embodiment.

[0070] The regulating member 45B has a central circular opening (not shown in Figure 11), an upper surface 45Bb, and a lower surface 45c. The upper surface 45Bb has a central plane 45d, a surrounding curved surface 45Bf, and a tapered surface 45Bi formed between the central plane 45d and the surrounding curved surface 45Bf, inclined with respect to a plane perpendicular to the center line of the regulating member 45B. The tapered surface 45Bi is conical in its entirety. The upper end of the non-contact tapered surface 45Bi is located radially outward from the flange 42a of the valve body support 42.

[0071] With the vibration-damping spring 44B assembled to the valve chamber VC, the bent portion 44g of the leg portion 44b contacts the central plane 45d and the surrounding curved surface 45Bf (i.e., at two points in the radial direction of the regulating member 45B), but does not contact the tapered surface 45Bi. Instead of the tapered surface 45Bi, for example, a stepped recess may be provided, and the shape is not limited. Even with this configuration in which the bent portion 44g contacts the regulating member 45B at two points, stress concentration in the bent portion 44g can be suppressed when assembled to the expansion valve. The lower curved surface 45Ah of the first modified example may be combined with this modified example.

[0072] (Third variation) Figure 12 is similar to Figure 8(b) in that it shows a third modified example. In this modified example, only the configuration of the restricting member 45C differs from that of the first embodiment; the other configurations are the same as those of the first embodiment, so redundant explanations are omitted. The restricting member 45C in this modified example can be used in place of the restricting member 45 of the first embodiment.

[0073] The regulating member 45C has a central circular opening (not shown in Figure 12), an upper surface 45Cb, and a lower surface 45c. The upper surface 45Cb has a central plane 45d, a surrounding curved surface 45Cf, and a tapered surface 45Ci formed between the central plane 45d and the surrounding curved surface 45Cf, inclined with respect to a plane perpendicular to the center line of the regulating member 45C. The tapered surface 45Ci is conical in its entirety. The upper end of the non-contact tapered surface 45Ci is positioned below the outer circumference of the flange portion 42a of the valve body support 42.

[0074] With the vibration-damping spring 44C assembled to the valve chamber VC, the central base 44a abuts against the central plane 45d, and the bent portion 44g of the leg portion 44b abuts against the surrounding curved surface 45Cf. In other words, the vibration-damping spring 44 contacts the regulating member 45C at two points in the radial direction, but does not contact the tapered surface 45Ci. In this modified example as well, stress concentration at the bent portion 44g can be suppressed when assembled to the expansion valve. The lower curved surface 45Ah of the first modified example may be combined with this modified example.

[0075] (Second embodiment) Figure 13 is a cross-sectional view showing the valve body 3, valve body support 42D, vibration damping spring 44D, and regulating member 45D assembled according to the second embodiment. Figure 14 is a bottom view of the configuration of Figure 13 as seen in the X direction. Figure 15 is a bottom view of the valve body support 42D as seen in the X direction of Figure 13. Figure 16 is a bottom view of the vibration damping spring 44D as seen in the X direction of Figure 13. Figure 17 is a bottom view of the regulating member 45D as seen in the X direction of Figure 13.

[0076] In this embodiment, only the configuration of the valve body support 42D, the vibration-damping spring 44D, and the regulating member 45D differs from that of the first embodiment; all other configurations are the same as in the first embodiment, so redundant explanations are omitted. The valve body support 42D, vibration-damping spring 44D, and regulating member 45D of this embodiment can be used in place of the valve body support 42, vibration-damping spring 44, and regulating member 45 of the first embodiment.

[0077] The valve body support 42D is formed by connecting a flange portion 42a and a cylindrical portion 42Db. As shown in Figure 15, the cylindrical portion 42Db has a shape as if a cylindrical shape had been cut by two planes parallel to the center line of the valve body support 42D, and has two parallel planes 42Dc and a partial cylindrical plane 42Dd on its outer circumference. That is, the cylindrical portion (or columnar portion) 42Db constituting the first engaging portion has a non-circular shape when viewed in the direction along the center line of the valve body support 42D. The other shapes of the valve body support 42D are the same as in the first embodiment.

[0078] The vibration-damping spring 44D is composed of a central base 44Da and a plurality (eight in this case) of legs 44b connected together. The central base 44Da has a mounting hole 44Dc, as shown in Figure 16. The mounting hole 44Dc has a shape like a circle connected by straight lines equidistant from the center of the vibration-damping spring 44D, and has two straight edges 44Dh and a partial circular edge 44Di on its inner circumference. That is, the mounting hole 44Dc constituting the second engagement portion has a non-circular shape when viewed in the direction along the center line of the vibration-damping spring 44D. The other shapes of the vibration-damping spring 44D are the same as in the first embodiment.

[0079] The regulating member 45D is comprised of a base portion 45Di and a plurality (eight in this case) of holding portions 45Dj extending radially from the base portion 45Di in correspondence with the leg portions 44b. The base portion 45Di has an upper surface 45Db with a surrounding curved surface 45Df. As shown in Figure 17, an opening 45Da is formed in the center of the base portion 45Di, and the opening 45Da has a shape as if a cylindrical shape had been cut by two planes parallel to the center line of the regulating member 45D, and has two parallel surfaces 45Dk and a partial cylindrical surface 45Dm on its inner circumference. That is, the opening 45Da constituting the third engagement portion has a non-circular shape when viewed in the direction along the center line of the regulating member 45D. The cylindrical portion 42Db, the mounting hole 44Dc, and the opening 45Da constitute a restraining structure that suppresses the relative rotation of the valve body support 42D, the vibration damping spring 44D, and the regulating member 45D.

[0080] The surrounding curved surface 45Df of each holding portion 45Dj has a common shape in any cross-section passing through the center line of the holding portion 45Dj and the regulating member 45D, and its cross-sectional shape is the same as that of the surrounding curved surface 45f in the first embodiment. The width of the holding portion 45Dj (length in the direction perpendicular to the direction in which the holding portion 45Dj extends) is preferably equal to the width of the leg portion 44b in the same direction. The other shape of the regulating member 45D is the same as in the first embodiment.

[0081] As shown in Figures 13 and 14, when the valve body 3, valve body support 42D, vibration damping spring 44D, and regulating member 45D are assembled, the cylindrical portion 42Db of the valve body support 42D is inserted through the mounting hole 44Dc of the vibration damping spring 44D and also through the opening 45Da of the regulating member 45D. At this time, the parallel surface 42Dc is positioned to face the straight edge 44Dh and the parallel surface 45Dk, and the partial cylindrical surface 42Dd is positioned to face the partial circular edge 44Di and the partial cylindrical surface 45Dm. As a result, relative rotation between the vibration damping spring 44D and the regulating member 45D around the centerline of the valve body support 42D is prevented.

[0082] Since relative rotation between the vibration-damping spring 44D and the regulating member 45D is prevented when assembled, as shown in Figure 14, the leg portion 44b of the vibration-damping spring 44D and the holding portion 45Dj of the regulating member 45D are aligned, and a roughly triangular prism-shaped space SP is always created between adjacent holding portions 45Dj. According to this embodiment, referring to Figure 1, when the valve is opened, the refrigerant flowing from the valve chamber VC of the expansion valve toward the valve seat 20 passes through the space SP, so that a larger amount of refrigerant can flow compared to the first embodiment.

[0083] (Third embodiment) Figure 18 is a cross-sectional view showing the valve body 3, valve body support 42E, vibration damping spring 44E, and regulating member 45E assembled according to the third embodiment. Figure 19 is a bottom view of the configuration of Figure 18 as seen in the X direction. Figure 20 is a bottom view of the valve body support 42E as seen in the X direction of Figure 18. Figure 21 is a bottom view of the vibration damping spring 44E as seen in the X direction of Figure 18. Figure 22 is a bottom view of the regulating member 45E as seen in the X direction of Figure 18.

[0084] In this embodiment, only the configuration of the valve body support 42E, the vibration-damping spring 44E, and the regulating member 45E differs from that of the first embodiment; all other configurations are the same as in the first embodiment, so redundant explanations are omitted. The valve body support 42E, vibration-damping spring 44E, and regulating member 45E of this embodiment can be used in place of the valve body support 42, vibration-damping spring 44, and regulating member 45 of the first embodiment.

[0085] The valve body support 42E is formed by connecting a flange portion 42a and a cylindrical portion 42Eb. As shown in Figure 20, the cylindrical portion 42Eb has a semi-cylindrical protrusion 42Ec on a part of its outer cylindrical surface that extends along the centerline of the valve body support 42E. The protrusion 42Ec constitutes a convex portion that projects radially outward from the center of the valve body support 42E. That is, the cylindrical portion 42Eb has a non-circular shape when viewed along the centerline of the valve body support 42E. The other shapes of the valve body support 42E are the same as in the first embodiment. Note that the semi-circular shape of the protrusion 42Ec as seen in Figure 20 is just one example. In other examples, the shape of the protrusion 42Ec as seen in Figure 20 may be a polygon such as a triangle or a quadrilateral, or it may be a semi-elliptical shape, or it may be any other shape.

[0086] The vibration-damping spring 44E consists of a central base 44Ea and a plurality (eight in this case) of legs 44b connected together. The central base 44Ea has a mounting hole 44Ec, and as shown in Figure 21, the mounting hole 44Ec has a semicircular recess (first recess) 44Eh at one location on its circular inner circumference. That is, the mounting hole 44Ec has a non-circular shape when viewed in the direction along the centerline of the vibration-damping spring 44D. The other shape of the vibration-damping spring 44E is the same as in the first embodiment.

[0087] The restricting member 45E is formed by connecting a base portion 45Ei and a plurality (eight in this case) of holding portions 45Ej that extend radially from the base portion 45Ei. As shown in Figure 22, the base portion 45Ei has a central opening 45Ea. The opening 45Ea has a semi-cylindrical recess (second recess) 45Eh at one location on its cylindrical inner circumference. That is, the opening 45Ea has a non-circular shape when viewed in the direction along the centerline of the restricting member 45E. The restraining structure is the same as in the third embodiment. The cylindrical portion 42Eb, the mounting hole 44Ec, and the opening 45Ea constitute the restraining structure.

[0088] As shown in Figures 18 and 19, when the valve body 3, valve body support 42E, vibration damping spring 44E, and regulating member 45E are assembled, the cylindrical portion 42Eb of the valve body support 42E is inserted through the mounting hole 44Ec of the vibration damping spring 44E and also through the opening 45Ea of the regulating member 45E. At this time, the raised portion 42Ec is positioned to engage with the recess 44Eh and the recess 45Eh. This prevents relative rotation between the vibration damping spring 44E and the regulating member 45E around the centerline of the valve body support 42E.

[0089] In the assembled state, relative rotation between the vibration-damping spring 44E and the regulating member 45E is prevented. As shown in Figure 19, the leg portion 44b of the vibration-damping spring 44E and the holding portion 45Ej of the regulating member 45E are aligned, and a roughly triangular prism-shaped space SP is always created between adjacent holding portions 45Ej. In this embodiment as well, referring to Figure 1, when the valve is opened, the refrigerant flowing from the valve chamber VC of the expansion valve toward the valve seat 20 passes through the space SP, allowing a larger amount of refrigerant to flow compared to the first embodiment.

[0090] (Fourth embodiment) Figure 23 is a cross-sectional view showing the valve body 3, valve body support 42, vibration damping spring 44, and regulating member 45F assembled according to the fourth embodiment. Figure 24 is a bottom view of the configuration of Figure 23 as seen in the X direction. Figure 25 is a bottom view of the regulating member 45F as seen in the X direction of Figure 23.

[0091] In this embodiment, only the configuration of the restricting member 45F differs from that of the first embodiment; all other configurations are the same as in the first embodiment, so redundant explanations are omitted. The restricting member 45F of this embodiment can be used in place of the restricting member 45 of the first embodiment.

[0092] The restricting member 45F has multiple (16 in this case) through holes 45Fh formed near its outer circumference at equal intervals in the circumferential direction. The other shape of the restricting member 45F is the same as in the first embodiment.

[0093] When the valve body 3, valve body support 42, vibration damping spring 44, and regulating member 45F are assembled, as shown in Figure 25, even if at least one of the through holes 45Fh is covered by the leg portion 44b, at least another of the through holes 45Fh is located between adjacent leg portions 44b. Therefore, in this embodiment as well, referring to Figure 1, when the valve is open, the refrigerant flowing from the valve chamber VC of the expansion valve toward the valve seat 20 passes through the through hole 45Fh and between adjacent leg portions 44b, allowing a larger amount of refrigerant to flow compared to the first embodiment.

[0094] The present invention is not limited to the embodiments described above. Within the scope of the present invention, any component of the embodiments described above can be modified. Furthermore, any component can be added to or omitted in the embodiments described above.

[0095] (Fifth embodiment) In the first embodiment, the expansion valve 1 was described as having a configuration in which each bent portion 44g of the multiple legs 44b of the vibration-damping spring 44 is always in contact with the regulating member 45. In other examples, the vibration-damping spring 44 may have a gap between the bent portion 44g and the regulating member 45 when, for example, the valve body 3 is not vibrating and therefore the legs 44 are not deformed. Then, when vibration occurs in the valve body 3 and deformation occurs in the legs 44b, the bent portion 44g may come into contact with the regulating member 45 to prevent further deformation of the legs 44b.

[0096] This example will be described as the fifth embodiment using Figure 26. In this embodiment, components that have the same function as in the first embodiment are denoted by the same reference numerals as in the first embodiment and their description is omitted. The expansion valve 1 of this embodiment differs from the first embodiment in that the biasing device 4 of the expansion valve 1 is equipped with a regulating member 45G instead of a regulating member 45. The other components are the same as in the first embodiment.

[0097] Figure 26 shows three states of the expansion valve 1 (not shown) of this embodiment, with the vibration-damping spring 44 and regulating member 45G installed in the valve chamber VC, denoted as (a), (b), and (c), respectively. Figures 26(a), (b), and (c) are enlarged cross-sectional views showing a portion of the vibration-damping spring 44 and a portion of the regulating member 45G, respectively. Figure 26 shows the vibration-damping spring 44 and regulating member 45G cut in the same way as in Figure 8. Here, the inner wall of the valve chamber VC is denoted by the symbol VCa.

[0098] Figure 26(a) shows a state in which no vibration occurs in the valve body 3, and therefore no deformation occurs in the prevention spring 44. Figure 26(b) shows a state in which, for example, vibration occurs in the valve body 3, causing the valve body 3, valve body support 42, and regulating member 45 to move toward the inner wall VCa of the valve chamber VC. Figure 26(c) shows a state in which they have moved even further toward the inner wall VCa of the valve chamber VC than in the state shown in Figure 26(b).

[0099] As shown in Figure 26(a), the restricting member 45G has the same shape as the restricting member 45 described in the first embodiment. For this reason, the same reference numerals are used for each part of the restricting member 45G as for the restricting member 45. The differences between the restricting member 45G and the restricting member 45 are as follows.

[0100] In other words, the surrounding curved surface 45f of the regulating member 45G has a shape that has a gap C between it and the bent portion 44g of the vibration-damping spring 44 when the vibration-damping spring 44 is installed in the valve chamber VC and no deformation occurs in the vibration-damping spring 44. In the prevention spring 44 of this embodiment, the bending state of the bent portion 44g when no deformation occurs in the vibration-damping spring 44 has a shape that results in a bending state in which the stress generated in the bent portion 44g is less than or equal to the allowable value of the bent portion 44g.

[0101] The tolerance value is a value that can be set arbitrarily. For example, the tolerance value may be the stress at which plastic deformation occurs in the bent portion 44g. Alternatively, the tolerance value may be a value that is a predetermined value smaller than the stress at which plastic deformation occurs. Alternatively, the tolerance value may be a predetermined stress value that is greater than the stress at which plastic deformation occurs.

[0102] As shown in Figure 26(b), the restricting member 45G has a shape such that when vibration occurs in the valve body 3, causing the valve body 3, valve body support 42, and restricting member 45G to move closer to the inner wall VCa of the valve chamber VC, and the vibration-damping spring 44 deforms as a result of this movement, the bent portion 44g contacts the surrounding curved surface 45f of the restricting member 45G before the stress generated in the bent portion 44g exceeds an allowable value.

[0103] As a result, as shown in Figure 26(c), even if the valve body 3, valve body support 42, and regulating member 45G move closer to the inner wall VCa of the valve chamber VC than in the state shown in Figure 26(b), the bent portion 44g is in contact with the surrounding curved surface 45f of the regulating member 45G, preventing further deformation. Therefore, the deformation occurs in parts of the vibration-damping spring 44 other than the bent portion 44g. Furthermore, in the state shown in Figure 26(c), the bendable portion of the leg portion 44b, in other words, the portion that functions as a spring, is the portion below the portion in contact with the regulating member 45G, and thus becomes shorter. As a result, the load generated by the portion that functions as a spring increases, and the same effect as in Figure 9(b) is obtained.

[0104] In this embodiment as well, the same effects as in the first embodiment can be obtained. In the second to fourth embodiments as well, similar to this embodiment, a configuration may be adopted in which there is a gap between the vibration-damping spring 44 and the surrounding curved surface of the regulating member 45 when the vibration-damping spring 44 is installed in the valve chamber VC and no deformation has occurred in the vibration-damping spring 44, so that when deformation occurs in the leg portion 44b, the bent portion 44g comes into contact with the surrounding curved surface 45f, thereby preventing the stress generated in the bent portion 44g from exceeding an allowable value.

[0105] This specification includes disclosures of the following inventions. (First aspect) A valve body comprising a valve chamber and a valve seat, A valve body arranged in the valve chamber, The valve body is biased toward the valve seat by a biasing device, The biasing device comprises a valve support connected to the valve body, a coil spring that generates a force to bias the valve body, a vibration-damping spring that displaces together with the valve support, and a regulating member disposed between the coil spring and the vibration-damping spring. The vibration-damping spring has a fixed portion sandwiched between the valve support and the regulating member, and a plurality of legs extending from the fixed portion. The leg portion has a bent portion connected to the fixed portion and a contact portion that abuts against the inner wall of the valve chamber. The restricting member is formed such that the bent portion can make contact with it. An expansion valve characterized by the following features.

[0106] (Second aspect) When the contact portion comes into contact with the inner wall of the valve chamber, the leg portion elastically deforms and the bent portion comes into contact with the regulating member. An expansion valve according to a first embodiment, characterized by the following:

[0107] (Third aspect) When the contact portion contacts the inner wall of the valve chamber, causing the leg portion to elastically deform, a gap is provided between the bent portion and the regulating member. If the leg portion deforms further by a predetermined amount from that state, the bent portion comes into contact with the restricting member. An expansion valve according to a first embodiment, characterized by the following:

[0108] (Fourth aspect) When the direction from the base to the tip of the leg is defined as the vertical direction, and the direction perpendicular to the vertical direction and the thickness direction of the leg is defined as the horizontal direction, the bent portion is formed in an arc shape when viewed from the horizontal direction. The bent portion makes surface contact with the regulating member. An expansion valve according to any of the first to third embodiments, characterized by the above.

[0109] (Fifth aspect) The upper surface of the regulating member has a first curved surface with a predetermined radius of curvature R in a cross-section passing through the center line of the regulating member. The lower surface of the regulating member has a second curved surface that connects to the first curved surface, With the contact portion in contact with the inner wall of the valve chamber, the leg portion can contact the second curved surface. An expansion valve according to any of the first to fourth embodiments, characterized by the above.

[0110] (Sixth aspect) With the contact portion in contact with the inner wall of the valve chamber, the upper surface of the restricting member is inclined with respect to a plane perpendicular to the center line of the restricting member and has a non-contact portion that does not come into contact with the bent portion. An expansion valve according to any of the first to fifth embodiments, characterized by the above.

[0111] (Seventh aspect) The aforementioned multiple legs extend radially from the fixed portion, The regulating member has a base and a plurality of holding portions that extend radially from the base in correspondence with the legs, A restraining structure is provided to suppress the relative rotation between the restraining member and the vibration-damping spring around the center line of the restraining member. An expansion valve according to any of the first to sixth embodiments, characterized by the above.

[0112] (Eighth aspect) Viewed along the centerline of the regulating member, the valve support has a first engagement portion which is a non-circular columnar or cylindrical shape, the vibration-damping spring has a second engagement portion which is a non-circular hole through which the first engagement portion is inserted, and the regulating member has a third engagement portion which is a non-circular hole through which the first engagement portion is inserted. The restraining structure is composed of the first engaging portion, the second engaging portion, and the third engaging portion. A seventh embodiment of an expansion valve characterized by the following:

[0113] (Ninth aspect) Viewed along the centerline of the regulating member, the valve support has a protrusion projecting away from the center of the valve support, the vibration damping spring has a first recess that engages with the protrusion, and the regulating member has a second recess that engages with the protrusion. The restraining structure is composed of the convex portion, the first recess, and the second recess. An expansion valve according to an eighth embodiment, characterized by the following:

[0114] (Tenth aspect) The aforementioned multiple legs extend radially from the fixed portion, The regulating member is a disc, and a plurality of through holes are formed near the outer circumference of the disc along the circumferential direction. An expansion valve according to any of the first to ninth embodiments, characterized by the above.

[0115] (11th form) The end face of the coil spring is a plane perpendicular to the center line of the coil spring, The regulating member has a plane that contacts the end face of the coil spring, An expansion valve according to any of the first to tenth embodiments, characterized by the above. [Explanation of symbols]

[0116] 1: Expansion valve 2: Valve body 3: Valve body 4: Biasing device 5: Actuator rod 6: Ring spring 8: Power Element 20: Alveolar seat 21: First channel 22: Second channel 221: Intermediate Room 23: Return channel 27: Orifice hole 28: Actuator rod insertion hole 29: Annular recess 41: Coil spring 42, 42D, 42E: Valve support 43: Spring support member 44, 44D, 44E: Vibration damping springs 45, 45A, 45B, 45C, 45D, 45E, 45F Regulating members 81: Stopper 82: Top cover component 83: Diaphragm 84: Stopper component 86: Receiving member 100: Refrigerant circulation system 101: Compressor 102: Capacitor 103: Evaporator VC: Valve chamber

Claims

1. A valve body comprising a valve chamber and a valve seat, A valve body arranged in the valve chamber, The valve body is biased toward the valve seat by a biasing device, The biasing device comprises a valve support connected to the valve body, a coil spring that generates a force to bias the valve body, a vibration-damping spring that displaces together with the valve support, and a regulating member disposed between the coil spring and the vibration-damping spring. The vibration-damping spring has a fixed portion sandwiched between the valve support and the regulating member, and a plurality of legs extending from the fixed portion. The leg portion has a bent portion connected to the fixed portion and a contact portion that abuts against the inner wall of the valve chamber. The restricting member is formed such that the bent portion can make contact with it. An expansion valve characterized by the following features.

2. When the contact portion comes into contact with the inner wall of the valve chamber, the leg portion elastically deforms and the bent portion comes into contact with the regulating member. The expansion valve according to feature 1.

3. When the contact portion contacts the inner wall of the valve chamber, causing the leg portion to elastically deform, a gap is provided between the bent portion and the regulating member. If the leg portion deforms further by a predetermined amount from that state, the bent portion comes into contact with the restricting member. The expansion valve according to claim 1.

4. When the direction from the base to the tip of the leg is defined as the vertical direction, and the direction perpendicular to the vertical direction and the thickness direction of the leg is defined as the horizontal direction, the bent portion is formed in an arc shape when viewed from the horizontal direction. The bent portion makes surface contact with the regulating member. The expansion valve according to feature 1.

5. The upper surface of the regulating member has a first curved surface with a predetermined radius of curvature R in a cross-section passing through the center line of the regulating member. The lower surface of the regulating member has a second curved surface that connects to the first curved surface. With the contact portion in contact with the inner wall of the valve chamber, the leg portion can contact the second curved surface. The expansion valve according to feature 1.

6. With the contact portion in contact with the inner wall of the valve chamber, the upper surface of the restricting member is inclined with respect to a plane perpendicular to the center line of the restricting member and has a non-contact portion that does not come into contact with the bent portion. The expansion valve according to feature 1.

7. The aforementioned multiple legs extend radially from the fixed portion, The regulating member has a base and a plurality of holding portions that extend radially from the base in correspondence with the legs, A restraining structure is provided to suppress the relative rotation between the restraining member and the vibration-damping spring around the center line of the restraining member. The expansion valve according to feature 1.

8. Viewed along the centerline of the regulating member, the valve support has a first engagement portion which is a non-circular columnar or cylindrical shape, the vibration-damping spring has a second engagement portion which is a non-circular hole through which the first engagement portion is inserted, and the regulating member has a third engagement portion which is a non-circular hole through which the first engagement portion is inserted. The restraining structure is composed of the first engaging portion, the second engaging portion, and the third engaging portion. The expansion valve according to feature 7.

9. Viewed along the centerline of the regulating member, the valve support has a protrusion projecting away from the center of the valve support, the vibration damping spring has a first recess that engages with the protrusion, and the regulating member has a second recess that engages with the protrusion. The restraining structure is composed of the convex portion, the first recess, and the second recess. The expansion valve according to feature 8.

10. The aforementioned multiple legs extend radially from the fixed portion, The regulating member is a disc, and a plurality of through holes are formed near the outer circumference of the disc along the circumferential direction. The expansion valve according to feature 1.

11. The end face of the coil spring is a plane perpendicular to the center line of the coil spring, The regulating member has a plane that contacts the end face of the coil spring, An expansion valve according to any one of claims 1 to 10, characterized by the features described herein.

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