Expansion valve

Abstract

To provide an expansion valve the weight of which can be reduced while preventing the fall of a valve element support from a coil spring during assembling work.SOLUTION: The expansion valve includes a valve body including a valve chest and a valve seat, a valve element capable of contacting / separating from the valve seat, an energizing device for energizing the valve element toward the valve seat, and an operation rod for pressing the valve element against the energizing force by the energizing device in a direction of separating from the valve seat, the energizing device having the coil spring for generating the energizing force, the valve element support for supporting the valve element, and a vibration preventing spring arranged between the coil spring and the valve element support, the vibration preventing spring having a projection part projecting toward the valve element support. With a recessed part formed in the face of the valve element support, opposed to the vibration preventing spring, the projection part engages to restrict relative displacement between the valve element support and the vibration preventing spring in a direction perpendicular to the axis of the valve element support.SELECTED DRAWING: Figure 1

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 thermal expansion valve that adjusts the amount of refrigerant passing through according to temperature has been used. In such a thermal expansion valve, a power element that drives a valve body via an operating rod by the pressure of the enclosed operating gas is adopted.

[0003] In the expansion valve shown in Patent Document 1, a cylindrical portion of a support member (valve body support) that supports the valve body is disposed inside a coil spring, thereby suppressing tilting of the support member with respect to the axis of the coil spring. As described above, by suppressing tilting of the support member with respect to the coil spring, when assembling the expansion valve, that is, when arranging an integral body of the coil spring, the support member, and the valve body in the valve chamber, the support member and the valve body are prevented from falling off the coil spring.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, the valve body is often formed from a metal material with a higher specific gravity than resin in consideration of wear resistance and the like. Further, since the cylindrical portion of the main body has a long shape in the axial direction to suppress the tilting of the support member, the mass of the support member increases. When the masses of the valve body and the support member that are displaced in response to the elastic deformation of the coil spring are large, the vibration energy increases due to the increase in the inertial mass, and it becomes difficult for the vibration of the valve body to converge. Also, there is a risk of an unfavorable configuration for vibration, such as becoming more likely to resonate due to a decrease in the natural frequency and the like.

[0006] Therefore, an object of the present invention is to provide an expansion valve that can prevent the valve body support from falling off the coil spring during the assembly operation and can be weight-reduced.

Means for Solving the Problems

[0007] To achieve the above object, an expansion valve according to the present invention includes a valve body having a valve chamber and a valve seat, a valve body that can be brought into contact with and separated from the valve seat, a biasing device that biases the valve body toward the valve seat, and an operating rod that presses the valve body in a direction away from the valve seat against the biasing force of the biasing device. The biasing device includes a coil spring that generates the biasing force, a valve body support that supports the valve body, and a vibration-proof spring disposed between the coil spring and the valve body support. The vibration-proof spring has a raised portion that bulges toward the valve body support. The raised portion engages with a recess formed in a surface of the valve body support facing the vibration-proof spring, thereby restricting relative displacement in a direction perpendicular to the axis of the valve body support between the valve body support and the vibration-proof spring.

Effects of the Invention

[0008] According to the present invention, it is possible to provide an expansion valve that can prevent the valve body support from falling off the coil spring during the assembly operation and can be weight-reduced.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 8

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Figure 12

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Figure 14

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] (Definition of directions) In this specification, the direction from the valve body 3 toward the actuating rod 5 is defined as the "upward direction", and the direction from the actuating rod 5 toward the valve body 3 is defined as the "downward direction". Therefore, in this specification, regardless of the posture of the expansion valve 1, the direction from the valve body 3 toward the actuating rod 5 is referred to as the "upward direction".

[0012] (First embodiment) Hereinafter, the expansion valve 1 in the first embodiment will be described. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 in this embodiment is applied to a refrigerant circulation system 100. FIG. 2 is a perspective view showing a state in which the valve body 3, the valve body support 42, the vibration-proof spring 44, the coil spring 41, and the spring receiving member 43 are disassembled from the valve body 2. FIG. 3 is a perspective view of the valve body 3 and the valve body support 42 as viewed from below. FIG. 4 is a perspective view of the vibration-proof spring 44 as viewed from above. FIG. 5 is an enlarged view showing the vicinity of the valve body support of the expansion valve 1. The center line of the actuating rod 5 of the expansion valve 1 is taken as the axis L.

[0013] In this embodiment, the expansion valve 1 is fluidly connected to a compressor 101, a condenser 102, and an evaporator 103.

[0014] As shown in FIG. 1, the expansion valve 1 includes a valve body 2 having a valve chamber VC, a spherical valve body 3, a biasing device 4, an actuating rod 5, and a power element 8.

[0015] In addition to the valve chamber VC, the valve body 2 includes 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 through the supply-side 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 through the orifice hole 27, the intermediate chamber 221, and the discharge-side flow path.

[0016] The first flow path 21 and the valve chamber VC communicate with each other through a connection path (also referred to as an introduction path) 21a having a smaller diameter than the first flow path 21. The valve chamber VC and the intermediate chamber 221 communicate with each other through the valve seat 20 and the orifice hole 27.

[0017] The operating rod insertion hole 28 formed above the intermediate chamber 221 has a function of guiding the operating rod 5, and the annular recess 29 formed above the operating rod insertion hole 28 has a function of accommodating the ring spring 6. The ring spring 6 abuts a plurality of spring pieces against the outer periphery of the operating rod 5 along the circumferential direction to apply a predetermined biasing force. The configuration of the ring spring 6 is described, for example, in Japanese Patent Application Laid-Open No. 2019-74236.

[0018] The valve body 3 is disposed in the valve chamber VC so as to be able to contact and separate 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 the refrigerant in the orifice hole 27 is restricted. This state is referred to as a non-communication state. However, even when the valve body 3 is seated on the valve seat 20, a limited amount of refrigerant may flow. On the other hand, as shown in FIG. 1, when the valve body 3 is separated from the valve seat 20, the flow of the refrigerant passing through the orifice hole 27 increases. This state is referred to as a communication state.

[0019] 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 described later.

[0020] The operating rod 5 can press the valve body 3 in the valve opening direction against the biasing force of the biasing device 4. When the operating rod 5 moves downward, the valve body 3 separates from the valve seat 20, and the expansion valve 1 is in an open state.

[0021] As shown in FIG. 2, the biasing device 4 includes a coil spring 41 formed by winding a wire in a spiral shape, a valve body support 42, a bottomed cylindrical spring receiving member 43, and a vibration-proof spring 44. The wire forming the coil spring 41 is preferably, for example, circular in cross section.

[0022] By cutting the spiral winding in a direction orthogonal to the center line of the spiral shape of the winding, the coil spring 41 is formed. At this time, the receiving surface 41a (schematically shown on only one side in FIG. 2) which is a plane is formed at both ends of the coil spring 41 by the cut ends. The receiving surface 41a on the lower end side abuts against the bottom surface of the spring receiving member 43, and the receiving surface 41a on the upper end side abuts against the lower surface of the valve body support 42.

[0023] The spring receiving member 43 that supports the lower end of the coil spring 41 is threadably engageable with the valve body 2 and has a function of sealing the valve chamber VC and a function of adjusting the biasing force of the coil spring 41. An O-ring OR having a sealing function is disposed between the spring receiving member 43 and the valve body 2.

[0024] In FIGS. 2, 3, and 5, the valve body support 42 is formed by, for example, forging or cutting a metal material, and includes a cylindrical portion 42a and a disk portion 42b having a larger diameter than the cylindrical portion 42a connected in series. The cylindrical portion 42a is formed to protrude from the upper surface of the disk portion 42b toward the valve body 3 side.

[0025] In the center of the lower surface of the disk portion 42b (the surface facing the coil spring 41), a cylindrical lower recess (simply referred to as a recess) 42c is formed. The lower recess 42c has a bottom wall 42d, but may penetrate the valve body support 42. Further, on the upper surface of the cylindrical portion 42a, a conical upper recess 42e is formed. Here, an example where the upper recess 42e is conical is shown, but its inner peripheral surface has a shape that inclines toward the lower end. As long as the recess has a function of aligning the center of the valve body 3 on the central axis of the valve body support 42 when the valve body 3 abuts, it is sufficient. Therefore, the upper recess is not limited to being conical, and the fact that the upper recess is conical is merely an example, and it may be pyramidal or spherical as long as the above function is exhibited.

[0026] As shown in FIGS. 2 and 4, the vibration-proof spring 44 is formed by connecting a central base portion 44a, a plurality (here, eight) of leg portions 44b, a substantially cylindrical raised portion 44g that rises upward from the central base portion 44a (toward the valve body support 42), and a circular inner flange portion 44h that extends radially inward from the upper end of the raised portion 44g. The vibration-proof spring 44 can be integrally formed, for example, by bending an elastic metal plate material such as stainless steel or its alloy by press forming (details will be described later). It is sufficient if there are three or more leg portions 44b at equal intervals in the circumferential direction. Note that the raised portion 44g preferably has a configuration in which a space is formed inside the raised portion 44g. Here, "a space is formed inside the raised portion 44g" means that the raised portion 44g is hollow (i.e., not solid). As shown in FIG. 5, in addition to the outer wall constituting the raised portion 44g being formed of a plate material with a substantially uniform plate thickness, the raised portion 44g having an inner surface (e.g., hemispherical shape) different from the outer surface (e.g., cylindrical shape) corresponds to this case.

[0027] The leg portion 44b has a shape that extends radially from the outer periphery 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 includes an upper portion 44d, a side portion 44e, and a protrusion portion 44f. Also, in the leg portion 44b, the boundary portion between the upper portion 44d and the side portion 44e constitutes a bent portion. Except for the bent portion, the upper portion 44d and the side portion 44e extend in a flat plate shape. Therefore, the upper portion 44d excluding the bent portion and the upper and lower surfaces of the central base portion 44a are connected flat surfaces.

[0028] In the free state where no elastic deformation occurs, the intersection angle between the upper portion 44d and the side portion 44e is preferably an obtuse angle.

[0029] In the central base portion 44a, a substantially triangular or arcuate notch portion 44k is formed between two adjacent upper portions 44d.

[0030] The protruding portion 44f is formed near the lower end of the side portion 44e and extends radially outward of an inscribed circle (which is an inscribed circle on a plane perpendicular to the center line of the vibration isolator spring 44) that contacts the eight leg portions 44b. For example, the protruding portion 44f can be formed by a spherical surface such as a hemispherical shape or a part of other curved surfaces. When the protruding portion 44f is mounted inside the valve body 2, it elastically contacts the upper wall of the connection passage 21a (the inner wall of the valve chamber VC). However, the dimensions of each part of the leg portion 44b are set so that the protruding portion 44f does not enter the connection passage 21a even when the valve body 3 is at the lowest limit position.

[0031] The vertical length of the leg portion 44b can be set to an appropriate length as long as the lower end portion of the leg portion 44b does not enter the connection passage 21a at the lowest end within the vertical movement range of the vibration isolator spring 44 that moves together with the valve body 3. In particular, it is desirable that the lower end portion of the leg portion 44b does not reach the connection passage 21a so as not to impede the flow of the refrigerant introduced from the connection passage 21a into the valve chamber VC and so that no flow rate reduction or turbulent flow generation occurs thereby.

[0032] When mounting the vibration isolator spring 44, the vibration isolator spring 44 is installed at the upper end of the coil spring 41, and the valve body support 42 and the valve body 3 are placed thereon from above. That is, the vibration isolator spring 44 is sandwiched between the coil spring 41 and the valve body support 42.

[0033] Also, as shown in FIG. 5, since the vicinity of the lower end of the valve body 3 abuts against and is held by the upper concave portion 42e of the valve body support 42, the coaxiality between the valve body 3 and the valve body support 42 is maintained. In the present embodiment, since the valve body 3, the valve body support 42, and the vibration isolator spring 44 are not joined to each other, the assembly man-hours can be reduced thereby. However, the valve body 3, the valve body support 42, and the vibration isolator spring 44 may be joined to each other by welding or the like in a state where they are assembled concentrically.

[0034] The vibration isolator spring 44 can be formed by press forming. Specifically, from a thin metal plate, in the first press forming, an intermediate product on a flat plate is formed in which the central base portion 44a and the leg portion 44b before bending are connected. In this first press forming, a central circular opening corresponding to the inner peripheral edge of the circular inner flange portion 44h is also simultaneously formed by punching. This circular opening has the effect of relaxing the tensile stress generated in the material in the second press forming.

[0035] Next, in the second press forming, the central base portion 44a and the leg portion 44b are bent, the protrusion portion 44f is formed to bulge, and while the raised portion 44g is extruded, the circular inner flange portion 44h is formed to form a three-dimensional vibration isolator spring. Note that the present invention is not limited thereto, and the vibration isolator spring 44 may be formed by a single press forming.

[0036] In the assembled state, the raised portion 44g of the vibration isolator spring 44 engages with the lower recess 42c of the valve body support 42 by a fitting with a gap. At this time, it is preferable that the circular inner flange portion 44h does not contact the bottom wall 42d. Further, since there is a gap in the radial direction (the direction perpendicular to the center line of the valve body support 42) between the lower recess 42c and the raised portion 44g, relative displacement between the valve body support 42 and the vibration isolator spring 44 is possible within the range of this gap. The direction of the gap may be in one direction in the radial direction or in all directions in the radial direction. Note that a configuration may be adopted in which relative displacement in the radial direction between the valve body support 42 and the vibration isolator spring 44 is not allowed. In that case, the lower recess 42c of the valve body support 42 and the raised portion 44g of the vibration isolator spring 44 can be press-fitted.

[0037] Furthermore, a part of the upper surface (here, a flat surface) of the central base portion 44a and the upper portion 44d of the vibration isolator spring 44 is in close contact with the lower surface (here, a flat surface) of the disk portion 42b of the valve body support 42. Also, a part of the lower surface (here, a flat surface) of the central base portion 44a and the upper portion 44d is in close contact with the receiving surface 41a of the coil spring 41. Since the plate thickness of the vibration isolator spring 44 is uniform, the valve body support 42 on the vibration isolator spring 44 does not tilt with respect to the coil spring 41, and the axes of the vibration isolator spring 44 and the valve body support 42 are stably supported to be parallel to the axis L.

[0038] At this time, the inner end of the notch 44k shown in FIG. 4 is located radially inward of the outer edge of the disk portion 42b.

[0039] After the valve body 3, the valve body support 42, the vibration-proof spring 44, and the coil spring 41 assembled in this way are mounted on the spring receiving member 43, they are inserted into the valve chamber VC of the valve body 2, and the spring receiving member 43 is screwed to the valve body 2, whereby the biasing device 4 can be installed on the valve body 2. At this time, as shown in FIG. 1, an O-ring OR having a sealing function is disposed between the spring receiving member 43 and the valve body 2.

[0040] In a state where the biasing device 4 is installed on the valve body 2, a downward biasing force acts on the valve body 3 from the operating rod 5, and an upward biasing force acts on the valve body support 42 from the coil spring 41. Therefore, even when the valve body 3, the valve body support 42, and the vibration-proof spring 44 are not joined to each other, coaxiality can be maintained without disassembling. Further, the protrusion 44f of the leg portion 44b of the vibration-proof spring 44 abuts on the inner wall of the valve chamber VC (having a cylindrical shape coaxial with the axis L), whereby the leg portion 44b is elastically deformed radially sideward with the outer edge of the disk portion 42b of the valve body support 42 as a fulcrum.

[0041] Next, the power element 8 will be described. In FIG. 1, the power element 8 includes a plug 81, an upper lid member 82, a diaphragm 83, a receiving member 86, and a stopper member 84. Here too, it is assumed that the upper lid member 82 side is the upper side and the receiving member 86 side is the lower side.

[0042] The upper lid member 82 is formed, for example, by subjecting a metal plate material to press working. The upper lid member 82 has an annular outer flange portion 82a and a central portion 82b that is continuously provided on the inner periphery of the outer flange portion 82a and bulges in a dome shape. An opening 82c is formed at the center of the central portion 82b and can be sealed by the plug 81.

[0043] The receiving member 86 facing the upper lid member 82 is formed by, for example, subjecting a metal plate material to pressing. The receiving member 86 has an outer diameter substantially the same as the outer diameter of the outer flange portion 82a, and is configured by connecting a dish-shaped flange portion 86a and a cylindrical portion 86b. A male thread 86c is formed on the outer periphery of the cylindrical portion 86b.

[0044] At the upper end of the valve body 2, a cylindrical recess 2a is formed, and an internal thread 2c that can be screwed into the male thread 86c is formed on the inner periphery of the recess 2a.

[0045] The diaphragm 83 disposed between the upper lid member 82 and the receiving member 86 is made of a thin and flexible metal (for example, SUS) plate material, and has an outer diameter substantially the same as the outer diameters of the upper lid member 82 and the receiving member 86.

[0046] The stopper member 84 is composed of a solid cylindrical main body and a disc portion extending radially outward from the main body, and has a fitting hole 84c in the shape of a pocket hole formed at the center of the lower surface of the main body.

[0047] Next, the assembly procedure of the power element 8 will be described. While arranging the stopper member 84 between the diaphragm 83 and the receiving member 86, the upper lid member 82, the diaphragm 83, and the receiving member 86 are overlapped in this order and pressed in the axial direction, and then their outer peripheries are welded by, for example, TIG welding, laser welding, plasma welding, etc. to be welded over the entire circumference to integrate them.

[0048] Subsequently, after enclosing the operating gas into the space (referred to as the pressure operating chamber PO) surrounded by the upper lid member 82 and the diaphragm 83 from the opening 82c formed in the upper lid member 82, the opening 82c is sealed with the plug 81, and further, for example, using projection welding, the plug 81 is fixed to the upper lid member 82.

[0049] At this time, the central portion of the diaphragm 83 is pressured in a form that protrudes toward the receiving member 86 by the working gas enclosed in the pressure working chamber PO. Therefore, the central portion of the diaphragm 83 abuts and is supported on the upper surface of the stopper member 84 disposed in the lower space LS surrounded by the diaphragm 83 and the receiving member 86. Thereby, the power element 8 is completed.

[0050] Furthermore, the configuration in which the valve body 3 and the biasing device 4 are integrated as described above is incorporated into the lower part of the valve body 2. At this time, since the raised portion 44g is engaged with the lower recess 42c, it is possible to prevent the valve body support 42 from falling off from the coil spring 44 during the assembly work. Thereafter, the operating rod 5 is inserted from above the valve body 2, passed through the communication hole 2b, and the lower end of the operating rod 5 is brought into contact with the valve body 3. Then, the power element 8 is brought closer from above the valve body 2, and the male thread 86c formed on the outer periphery of the lower end of the cylindrical portion 86b is screwed into the female thread 2c formed on the inner periphery of the recess 2a of the valve body 2. As the male thread 86c is screwed into the female thread 2c, the lower surface of the receiving member 86 abuts on the upper end surface of the valve body 2, and the upper end of the operating rod 5 is fitted into the fitting hole 84c of the stopper member 84. Thereby, the power element 8 can be fixed to the valve body 2.

[0051] A packing PK is interposed between the assembled power element 8 and the valve body 2, and the space in the recess 2a connected to the lower space LS is sealed to prevent external leakage of the refrigerant from the recess 2a. In such a state, the lower space LS of the power element 8 communicates with the return flow path 23 through the communication hole 2b formed between the recess 2a and the return flow path 23. Thus, the expansion valve 1 is completed.

[0052] (Operation of the expansion valve) With reference to FIG. 1, an operation example of the expansion valve 1 will be described. The refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valve 1. Further, the refrigerant adiabatically expanded by the expansion valve 1 is sent out to the evaporator 103, and heat exchange is performed with the air flowing around the evaporator in the evaporator 103. The refrigerant returning from the evaporator 103 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return flow path 23).

[0053] The expansion valve 1 is supplied with high-pressure refrigerant from the capacitor 102. More specifically, the high-pressure refrigerant from the capacitor 102 is supplied to the valve chamber VC through the first flow path 21.

[0054] As shown in FIG. 2, when the valve body 3 is seated on the valve seat 20 (when in the non-communication state), the flow rate of the refrigerant sent from the valve chamber VC through the orifice hole 27, the intermediate chamber 221, and the second flow path 22 to the evaporator 103 is restricted. On the other hand, as shown in FIG. 1, when the valve body 3 is separated from the valve seat 20 (when in the communication state), the flow rate of the refrigerant sent from the valve chamber VC through the orifice hole 27, the intermediate chamber 221, and the second flow path 22 to the evaporator 103 increases. The switching between the closed state and the open state of the expansion valve 1 is performed by the operating rod 5 connected to the power element 8 via the stopper member 84.

[0055] In FIG. 1, inside the power element 8, a pressure operating chamber PO and a lower space LS partitioned by a diaphragm 83 are provided. Therefore, when the pressure of the operating gas in the pressure operating chamber PO decreases, the diaphragm 83 rises, so that the stopper member 84 and the operating rod 5 move upward according to the biasing force of the coil spring 41.

[0056] On the other hand, when the pressure of the operating gas in the pressure operating chamber PO increases, the diaphragm 83 and the stopper member 84 are pressed downward, so that the operating rod 5 moves downward. Further, the refrigerant in the refrigerant circulation system 100 can pass through the gap between the stopper member 84 and the receiving member 86 to reach the lower space LS of the power element 8. Therefore, according to the temperature and pressure of the refrigerant flowing through the return flow path 23, the volume of the operating gas in the pressure operating chamber PO changes, and the operating rod 5 is driven. In other words, in the expansion valve 1 shown in FIG. 1, the amount of refrigerant supplied from the expansion valve 1 toward 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.

[0057] According to this embodiment, the valve body support 42 is disposed above the vibration isolator spring 44, does not fit inside the coil spring 41, and has a thin structure with a relatively short axial length. Further, the raised portion 44g of the vibration isolator spring 44 engages with the lower concave portion 42c of the valve body support 42. The inner peripheral surface of the lower concave portion 42c of the valve body support 42 is cylindrical and not spiral. Therefore, the raised portion 44g of the vibration isolator spring 44 faces the inner peripheral surface of the lower concave portion 42c in any direction of 360 degrees. As a result, even when the valve body support 42 tilts in any direction with respect to the axis L, the raised portion 44g abuts against the lower concave portion 42c. Therefore, it is not necessary to increase the length of the raised portion 44g of the vibration isolator spring 44 in the direction of the axis L. Further, even if the length of the raised portion 44g is short, the function of holding the valve body support 42 does not deteriorate. As described above, the valve body support 42 can be miniaturized and lightened, and by reducing the inertial mass, the vibration energy can be reduced and the vibration characteristics can be improved.

[0058] Furthermore, according to this embodiment, the protrusion 44f of the leg portion 44b of the vibration isolator spring 44 abuts against the inner wall of the valve chamber VC and the leg portion 44b is elastically deformed, so that the protrusion 44f is pressed against the inner wall of the valve chamber VC with a predetermined force by the elastic force of the leg portion 44b. Therefore, it is possible to generate a sliding resistance according to the movement of the valve body 3. Thereby, the vibration of the valve body 3 and the operating rod 5 can be suppressed.

[0059] In addition, the protrusions 44f of the leg portions 44b having a common (point-symmetrical shape when viewed in the axial direction L) shape abut against the inner wall of the valve chamber VC, respectively, so that the center of the vibration isolator spring 44 is positioned so as to substantially coincide with the axis L, and the vibration isolator spring 44 is also positioned between the coil spring 41 and the inner wall of the valve chamber VC. Thus, tilting of the vibration isolator spring 44 is suppressed. For this reason, by fitting (engaging) the raised portion 44g of the vibration isolator spring 44 into the lower concave portion 42c of the valve body support 42, the center of the valve body 3 can be positioned with respect to the axis L together with the valve body support 42.

[0060] The vibration-proof spring 44 is sandwiched between the valve body support 42 and the coil spring 41, and is biased toward the valve body support 42 by the elastic force of the coil spring 41. Therefore, it is held in a stable state, and thereby tilting of the valve body support 42 is also suppressed.

[0061] Since there is a gap between the lower concave portion 42c and the raised portion 44g, even if the center of the lower concave portion 42c is eccentric with respect to the axis L after assembly, when the valve body 3 first seats on the valve seat 20, the valve body 3 and the valve body support 42 can be displaced so that the center of the valve body 3 approaches the axis L by utilizing the gap.

[0062] Further, all the leg portions 44b of the vibration-proof spring 44 are elastically deformed with the outer edge of the disk portion 42b of the valve body support 42 as a fulcrum, so that the elastic deformation of each leg portion 44b becomes uniform. Therefore, since the biasing force applied from the vibration-proof spring 44 to the valve body 3 and the valve body support 42 is substantially uniform in the circumferential direction, the valve body 3 and the valve body support 42 are stably supported, and the vibration-proof function of the vibration-proof spring 44 that suppresses vibration of the valve body 3 is also stabilized.

[0063] Furthermore, since the vibration-proof spring 44 is in contact with the inner wall above the connection path 21a in the valve chamber VC, the leg portion 44b does not interfere with the connection path 21a, suppressing the generation of turbulent flow in the refrigerant introduced from the connection path 21a into the valve chamber VC, and can keep the passing sound of the refrigerant low.

[0064] In addition, since the vibration-proof spring 44 has a notch portion 44k on the surface having the central base portion 44a, the tip side from the bent portion consists only of the leg portion 44b, facilitating the design of the vibration-proof spring 44 including setting of the spring constant.

[0065] (Second Embodiment) FIG. 6 is a perspective view of the valve body 3 and the valve body support 42A according to the second embodiment, as viewed from below. FIG. 7 is a perspective view of the vibration isolator spring 44A according to the second embodiment, as viewed from above. FIG. 8 is an enlarged view showing the vicinity of the valve body support according to the second embodiment. In the present embodiment, only the configurations of the valve body support 42A and the vibration isolator spring 44A are different from those of the first embodiment, and since the other configurations are the same as those of the first embodiment, duplicate explanations are omitted.

[0066] The valve body support 42A is formed, for example, by performing forging, cutting, or the like on a metal material. As shown in FIGS. 6 and 8, the valve body support 42A includes a cylindrical portion 42Aa and a disk portion 42Ab having a diameter larger than that of the cylindrical portion 42Aa, which are connected in series. The cylindrical portion 42Aa has the same shape as that of the first embodiment described above.

[0067] A lower recess 42Ac is formed at the center of the lower surface of the disk portion 42Ab. The lower recess 42Ac has a conical surface (conical inner surface) 42Ae that tapers upward and a central bottom wall 42Ad.

[0068] As shown in FIG. 7, the vibration isolator spring 44A includes a central base portion 44Aa, a plurality (here, eight) of leg portions 44Ab, and a raised portion 44Ag that rises upward from the central base portion 44Aa, which are connected in series. The raised portion 44Ag has a frustoconical (i.e., conical) outer peripheral surface that tapers upward, and its top is a circular opening 44Ai. The vibration isolator spring 44A can be integrally formed, for example, by press-forming from an elastic metal plate material such as stainless steel or its alloy, and can be formed from the same process as the vibration isolator spring 44 of the first embodiment described above. In other configurations, the central base portion 44Aa and the leg portions 44Ab have the same shape as those of the first embodiment described above.

[0069] When mounting the vibration isolator spring 44A, the vibration isolator spring 44A is installed at the upper end of the coil spring 41, and the valve body support 42A and the valve body 3 are placed thereon in this order from above. That is, the vibration isolator spring 44A is sandwiched between the coil spring 41 and the valve body support 42A.

[0070] In the assembled state, the raised portion 44Ag of the vibration isolation spring 44A fits (engages) into the lower recess 42Ac of the valve body support 42A. Since there is a radial gap between the lower recess 42Ac and the raised portion 44Ag, the valve body support 42A and the vibration isolation spring 44A can be displaced relative to each other within the range of this gap.

[0071] Furthermore, the central base portion 44Aa of the vibration isolation spring 44A and a part of the upper surface (here a flat surface) of the upper portion 44Ad are in close contact with the lower surface (here a flat surface) of the disk portion 42Ab of the valve body support 42A. Also, the lower surface (here a flat surface) of the central base portion 44Aa and a part of the upper portion 44Ad is in close contact with the receiving surface 41a of the coil spring 41 (see FIG. 2). Since the thickness of the vibration isolation spring 44A is uniform, the valve body support 42A on the vibration isolation spring 44A is stably supported so that the axes of the vibration isolation spring 44A and the valve body support 42A are parallel to the axis L without tilting with respect to the coil spring 41.

[0072] (Third Embodiment) FIG. 9 is a perspective view of the valve body 3 and the valve body support 42B according to the third embodiment as viewed from below. FIG. 10 is a perspective view of the vibration isolation spring 44B according to the third embodiment as viewed from above. FIG. 11 is an enlarged view showing the vicinity of the valve body support according to the third embodiment. In the present embodiment, only the configurations of the valve body support 42B and the vibration isolation spring 44B are different from those of the first embodiment, and since the other configurations are the same as those of the first embodiment, redundant descriptions are omitted.

[0073] The valve body support 42B is formed, for example, by subjecting a metal material to forging, cutting, or the like, and as shown in FIGS. 9 and 11, includes a cylindrical portion 42Ba and a disk portion 42Bb having a larger diameter than the cylindrical portion 42Ba connected in series. The cylindrical portion 42Ba has the same shape as that of the first embodiment described above.

[0074] In the vicinity of the outer periphery of the lower surface of the disk portion 42Bb, a lower recess 42Bc is formed. The lower recess 42Bc is a circumferential groove arranged at an equal distance from the center of the valve body support 42B (formed so as to surround the center). The cross-sectional shape of the circumferential groove orthogonal to the circumferential direction is a semi-circular shape here, but it is not limited thereto and may be a rectangular shape or the like. The lower surface of the disk portion 42Bb other than the lower recess 42Bc is a plane orthogonal to the axis L.

[0075] As shown in FIG. 10, the vibration isolator spring 44B is formed by connecting a central base portion 44Ba, a plurality (here, eight) of leg portions 44Bb, and a substantially cylindrical raised portion 44Bg that rises upward from the central base portion 44Ba. The raised portion 44Bg has a circumferential convex shape arranged at an equal distance from the center of the vibration isolator spring 44B. The cross-sectional shape of the raised portion 44Bg orthogonal to the circumferential direction is a semi-circular shape here, but it is not limited thereto and may be a rectangular shape or the like.

[0076] The vibration isolator spring 44B can be integrally formed by press-forming from an elastic metal plate material such as stainless steel or its alloy, and can be formed from the same process as the vibration isolator spring 44 of the first embodiment described above. A circular opening 44Bi is formed at the center of the central base portion 44Ba. In other configurations, the central base portion 44Ba and the leg portions 44Bb have the same shape as those of the first embodiment described above.

[0077] When mounting the vibration isolator spring 44B, the vibration isolator spring 44B is installed at the upper end of the coil spring 41, and the valve body support 42B and the valve body 3 are placed thereon in this order from above. That is, the vibration isolator spring 44B is sandwiched between the coil spring 41 and the valve body support 42B.

[0078] In the assembled state, the raised portion 44Bg of the vibration isolator spring 44B fits (engages) into the lower recess 42Bc of the valve body support 42B. At this time, since there is a radial gap between the lower recess 42Bc and the raised portion 44Bg, the valve body support 42B and the vibration isolator spring 44B can be relatively displaced within the range of this gap.

[0079] Furthermore, the central base portion 44Ba of the vibration isolation spring 44B and a part of the upper surface (here, a flat surface) of the upper portion 44Bd are in close contact with the lower surface (here, a flat surface) of the disk portion 42Bb of the valve body support 42B. Also, the central base portion 44Ba and a part of the lower surface (here, a flat surface) of the upper portion 44Bd are in close contact with the receiving surface 41a (see FIG. 2) of the coil spring 41. Since the plate thickness of the vibration isolation spring 44B is uniform, the valve body support 42B on the vibration isolation spring 44B does not tilt with respect to the coil spring 41, and the axes of the vibration isolation spring 44B and the valve body support 42B are stably supported so as to be parallel to the axis L.

[0080] (Fourth Embodiment) FIG. 12 is a perspective view of the valve body 3 and the valve body support 42C according to the fourth embodiment as viewed from below. FIG. 13 is a perspective view of the vibration isolation spring 44C according to the fourth embodiment as viewed from above. FIG. 14 is an enlarged view showing the vicinity of the valve body support according to the fourth embodiment. In the present embodiment, only the configurations of the valve body support 42C and the vibration isolation spring 44C are different from those of the first embodiment, and since the other configurations are the same as those of the first embodiment, redundant descriptions are omitted.

[0081] The valve body support 42C is formed by, for example, performing forging or cutting on a metal material, and as shown in FIGS. 12 and 14, a cylindrical portion 42Ca and a disk portion 42Cb having a larger diameter than the cylindrical portion 42Ca are connected. The cylindrical portion 42Ca has the same shape as that of the first embodiment described above.

[0082] In the vicinity of the outer periphery of the lower surface of the disk portion 42Cb, a plurality of (here, four) lower recesses 42Cc are formed at a predetermined distance equal from the center of the vibration isolation spring 44C and at equal intervals in the circumferential direction. The lower recesses 42Cc have, for example, a substantially hemispherical inner surface, but are not limited thereto and may have a cylindrical surface shape. Also, the number of the lower recesses 42Cc is not limited to four and may be two or five or more. The lower surface of the disk portion 42Cb other than the lower recesses 42Cc is a plane orthogonal to the axis L. Here, the substantially hemispherical shape includes not only a complete hemispherical shape but also a shape similar to a hemisphere, for example, a shape in which the hemispherical shape is compressed in the vertical direction.

[0083] As shown in Fig. 13, the vibration isolator spring 44C is formed by connecting a central base portion 44Ca, a plurality (here, eight) of leg portions 44Cb, and a plurality (here, four) of raised portions 44Cg that bulge upward near the outer periphery of the central base portion 44Ca. The raised portions 44Cg are arranged at a predetermined distance equal from the center of the vibration isolator spring 44C and at equal intervals in the circumferential direction, and have a substantially hemispherical outer surface corresponding to the lower recess 42Cc. However, the shape of the outer surface of the raised portion 44Cg is not limited thereto, and it may have a shape that can be engaged corresponding to the inner surface of the lower recess 42Cc.

[0084] The vibration isolator spring 44C can be integrally formed, for example, by press-forming from an elastic metal plate material such as stainless steel or its alloy, and can be formed from the same process as the vibration isolator spring 44 in the first embodiment described above. In other configurations, the central base portion 44Ca and the leg portions 44Cb have the same shape as in the first embodiment described above.

[0085] When mounting the vibration isolator spring 44C, the vibration isolator spring 44C is installed at the upper end of the coil spring 41, and the valve body support 42C and the valve body 3 are placed in this order from above. That is, the vibration isolator spring 44C is sandwiched between the coil spring 41 and the valve body support 42C.

[0086] In the assembled state, the raised portion 44Cg of the vibration isolator spring 44C engages with the lower recess 42Cc of the valve body support 42C. At this time, since there is a radial gap between the lower recess 42Cc and the raised portion 44Cg, the valve body support 42C and the vibration isolator spring 44C can be relatively displaced within the range of this gap.

[0087] Furthermore, the upper surface (here, a flat surface) of a part of the central base 44Ca and the upper part 44Cd of the vibration isolator spring 44C is in close contact with the lower surface (here, a flat surface) of the disk part 42Cb of the valve body support 42C. Also, the lower surface (here, a flat surface) of a part of the central base 44Ca and the upper part 44Cd is in close contact with the receiving surface 41a (see FIG. 2) of the coil spring 41. Since the plate thickness of the vibration isolator spring 44C is uniform, the valve body support 42C on the vibration isolator spring 44C is stably supported so as not to tilt with respect to the coil spring 41, and the axes of the vibration isolator spring 44C and the valve body support 42C are parallel to the axis L.

[0088] Note that the shapes of the lower concave portion and the raised portion are not limited to those of the above-described embodiments. For example, the lower concave portion can be a linear groove extending in the radial direction, and the raised portion can be a linear convex portion engaging with the linear groove.

[0089] The present invention is not limited to the above-described embodiments. Within the scope of the present invention, any component of the above-described embodiments can be modified. Also, addition or omission of any component in the above-described embodiments is possible.

[0090] This specification includes the following disclosure of the invention. (First aspect) A valve body having a valve chamber and a valve seat, A valve body that can contact and separate from the valve seat, A biasing device that biases the valve body toward the valve seat, An operating rod that presses the valve body in a direction away from the valve seat against the biasing force of the biasing device, and The biasing device includes a coil spring that generates the biasing force, a valve body support that supports the valve body, and a vibration isolator spring disposed between the coil spring and the valve body support, The vibration isolator spring has a raised portion that bulges toward the valve body support, The raised portion engages with a recess formed in a surface of the valve body support facing the vibration isolator spring, thereby restricting relative displacement in a direction orthogonal to the axis of the valve body support between the valve body support and the vibration isolator spring. An expansion valve characterized by the above.

[0091] (Second aspect) A space is formed inside the raised portion The expansion valve according to the first aspect, characterized in that

[0092] (Third aspect) The vibration-proof spring has a central base portion and a plurality of leg portions extending from the central base portion The leg portions contact the inner wall of the valve chamber The expansion valve according to the first aspect or the second aspect, characterized in that

[0093] (Fourth aspect) A gap is provided along the direction perpendicular to the axis between the concave portion and the raised portion The expansion valve according to any one of the first aspect to the third aspect, characterized in that

[0094] (Fifth aspect) The concave portion has a cylindrical inner peripheral surface, and the raised portion has a cylindrical outer peripheral surface The expansion valve according to any one of the first aspect to the fourth aspect, characterized in that

[0095] (Sixth aspect) The concave portion has a conical inner surface, and the raised portion has a conical outer surface The expansion valve according to any one of the first aspect to the fourth aspect, characterized in that

[0096] (Seventh aspect) The concave portion is a circumferential groove formed so as to surround the center of the valve body support, and the raised portion has a circumferential convex shape The expansion valve according to any one of the first aspect to the fourth aspect, characterized in that

[0097] (Eighth aspect) The concave portion has a substantially hemispherical inner surface, and the raised portion has a substantially hemispherical outer surface The expansion valve according to any one of the first aspect to the fourth aspect, characterized in that

[0098] (The ninth aspect) The vibration damping spring is formed by bending a metal plate material, and an opening is formed at the center of the vibration damping spring. The expansion valve according to any one of the first aspect to the eighth aspect, characterized by this.

Explanation of symbols

[0099] 1: Expansion valve 2: Valve body 3: Valve element 4: Biasing device 5: Actuating rod 6: Ring spring 8: Power element 20: Valve seat 21: First flow path 22: Second flow path 221: Intermediate chamber 23: Return flow path 27: Orifice hole 28: Actuating rod insertion hole 29: Annular recess 41: Coil spring 42, 42A, 42B, 42C: Valve element support 43: Spring receiving member 44, 44A, 44B, 44C: Vibration damping spring 81: Plug 82: Upper cover member 83: Diaphragm 84: Stopper member 86: Receiving member 100: Refrigerant circulation system 101: Compressor 102: Condenser 103: Evaporator VC: Valve chamber

Claims

1. a valve body having a valve chamber and a valve seat; a valve body that is movable toward and away from the valve seat; a biasing device that biases the valve body toward the valve seat; an actuating rod that presses the valve body in a direction away from the valve seat against the biasing force of the biasing device, the biasing device includes a coil spring that generates the biasing force, a valve body support that supports the valve body, and a vibration-proof spring that is disposed between the coil spring and the valve body support, The vibration-proof spring has a protruding portion protruding toward the valve body support, The protruding portion engages with a recess formed on a surface of the valve body support facing the vibration-proof spring, thereby limiting relative displacement between the valve body support and the vibration-proof spring in a direction perpendicular to the axis of the valve body support. An expansion valve characterized by:

2. A space is formed inside the protrusion.

2. The expansion valve according to claim 1 .

3. The vibration-damping spring has a central base and a plurality of legs extending from the central base, The leg portion abuts against an inner wall of the valve chamber.

2. The expansion valve according to claim 1 .

4. A gap is provided between the recess and the protrusion along a direction perpendicular to the axis.

2. The expansion valve according to claim 1 .

5. The recess has a cylindrical inner circumferential surface, and the protuberance has a cylindrical outer circumferential surface.

2. The expansion valve according to claim 1 .

6. The recess has a conical inner surface and the protuberance has a conical outer surface.

2. The expansion valve according to claim 1 .

7. The recess is a circumferential groove formed around the center of the valve body support, and the raised portion has a circumferential convex shape.

2. The expansion valve according to claim 1 .

8. The recess has a substantially hemispherical inner surface, and the protrusion has a substantially hemispherical outer surface.

2. The expansion valve according to claim 1 .

9. The vibration-proof spring is formed by bending a metal plate material, and an opening is formed in the center of the vibration-proof spring. The expansion valve according to any one of claims 1 to 8.

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