Expansion valve

Abstract

To provide an expansion valve which can smoothly open and close a valve body while suppressing the vibration of the valve body.SOLUTION: An expansion valve has a valve main body having a valve seat and a valve chamber, a valve body for limiting the passage of fluid by being seated on the valve seat, and permitting the passage of the fluid by separating from the valve seat, and an energization device for energizing the valve body in a prescribed direction progressing toward the valve seat. The energization device has a valve body support for supporting the valve body, a coil spring for energizing the valve body support to the prescribed direction, and a guide sleeve fixed to the valve main body, and guiding the valve body support. The valve body support and the guide sleeve have slide faces which slide at a periphery of the coil spring.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] 2. Description of the Related Art Conventionally, in refrigeration cycles used in air conditioners and the like mounted on automobiles, a temperature sensitive expansion valve is used which adjusts the amount of refrigerant passing through the valve in accordance with temperature.

[0003] For example, the expansion valve shown in Patent Document 1 has an inlet port into which high-pressure refrigerant is introduced and a valve chamber communicating with the inlet port, and is equipped with a valve member drive mechanism called a power element at the top of the valve body. A spherical valve disc disposed in the valve chamber faces a valve seat that opens into the valve chamber, and is driven by the power element via an actuating rod to control the opening of a throttle passage between the valve seat.

[0004] When the valve is opened, the valve disc is slightly pressed by the actuating rod and moves away from the valve seat by a small distance, and the gap between the valve seat and the valve disc becomes non-uniform around the axis, so the amount of refrigerant passing around the valve disc also becomes non-uniform, and the valve disc is subjected to different fluid pressures from various directions.

[0005] On the other hand, the actuating rod that contacts the valve disc is inserted and guided through the insertion hole of the valve body, but a certain amount of clearance is provided between the insertion hole and the actuating rod so as not to prevent the relative sliding of the actuating rod. Since the actuating rod can move relative to the insertion hole in the direction perpendicular to the axis by the amount of this clearance, it is difficult for the actuating rod to restrain the valve disc when the valve disc is subjected to fluid pressure from the surroundings as described above. Therefore, the valve disc subjected to fluid pressure moves irregularly in the axial direction and the direction perpendicular to the axis together with the actuating rod, which leads to so-called valve disc vibration.

[0006] To prevent such valve disc vibration, Patent Document 1 discloses a technology in which a guide portion is provided on an adjustment screw fixed to the valve body, and this guide portion is fitted into a support member that supports the valve disc, thereby guiding the valve disc in the axial direction and suppressing movement perpendicular to the axis. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6745636 specification Summary of the Invention [Problem to be solved by the invention]

[0008] In the technology of Patent Document 1, the guide part is disposed inside the coil spring, which can contribute to the miniaturization of the expansion valve, but this causes a problem that the sliding area between the guide part and the support member cannot be secured large. Also, if the fitting diameter between the guide part and the support member is small, the support member is likely to tilt with respect to the axis, which causes a problem that sticking is likely to occur between the sliding surfaces.

[0009] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an expansion valve capable of smoothly opening and closing the valve body while suppressing vibration of the valve body. [Means for solving the problem]

[0010] In order to achieve the above object, the expansion valve according to the present invention comprises: a valve body including a valve seat and a valve chamber; a valve body that restricts the passage of a fluid by being seated on the valve seat and allows the passage of the fluid by being separated from the valve seat; a biasing device that biases the valve body in a predetermined direction toward the valve seat, The biasing device supports the valve body. Cylindrical a valve body support, a coil spring that biases the valve body support in the predetermined direction, and a guide sleeve that is fixed to the valve body and guides the valve body support, The valve body support and the guide sleeve have sliding surfaces that slide around the coil spring. picture, The valve body has a spring receiving member, The spring receiving member has a disk-shaped receiving body and a circular tube portion coaxially connected to the receiving body, The guide sleeve is a bottomed tubular member disposed within the circular tubular portion, A groove formed on the outer circumferential surface; an opening formed in a bottom wall, the opening communicating an internal space of the guide sleeve with the outside; an annular portion formed in a portion of the outer periphery of the outer end surface of the bottom wall other than the groove, extending from one end of the groove in the circumferential direction to the other end and extending to the receiving body; having a spring chamber for accommodating the coil spring is formed by the valve body support and the guide sleeve, and the fluid moves between the inside and outside of the spring chamber via a communication portion in response to movement of the valve body; The communication portion is a first communication passage surrounded by the circular pipe portion and the groove and communicating with the valve chamber; a second communication passage surrounded by the receiving body, the outer end surface of the guide sleeve, and the annular portion, the second communication passage communicating with both the first communication passage and the opening; have It is characterized by: Further, the expansion valve according to the present invention comprises: a valve body including a valve seat and a valve chamber; a valve body that restricts the passage of a fluid by being seated on the valve seat and allows the passage of the fluid by being separated from the valve seat; a biasing device that biases the valve body in a predetermined direction toward the valve seat, the biasing device includes a valve element support having a cylindrical shape with a top that supports the valve element, a coil spring that biases the valve element support in the predetermined direction, and a guide sleeve that is fixed to the valve body and guides the valve element support, the valve body support and the guide sleeve have sliding surfaces that slide around the coil spring, The valve body has a spring receiving member, The spring receiving member has a disk-shaped receiving body and a circular tube portion coaxially connected to the receiving body, and an inner groove is formed between the inner surface of the circular tube portion and the receiving body, The guide sleeve is a bottomed tubular member disposed within the circular tubular portion, an opening formed in a bottom wall, the opening communicating an internal space of the guide sleeve with the outside; an annular portion formed on the outer periphery of the outer end surface of the bottom wall and extending to the receiving body; having a spring chamber for accommodating the coil spring is formed by the valve body support and the guide sleeve, and the fluid moves between the inside and outside of the spring chamber via a communication portion in response to movement of the valve body; The communication portion is a first communication passage surrounded by the inner groove and the guide sleeve and communicating with the valve chamber; a second communication passage surrounded by the receiving body, the outer end surface of the guide sleeve, and the annular portion, the second communication passage communicating with both the first communication passage and the opening; The present invention is characterized by having the following. Effect of the Invention

[0011] According to the present invention, it is possible to provide an expansion valve capable of smoothly opening and closing the valve body while suppressing vibration of the valve body. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example in which an expansion valve according to the present embodiment is applied to a refrigerant circulation system. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing the vicinity of the biasing device in the expansion valve of FIG. [Diagram 3] FIG. 3 is an enlarged cross-sectional view showing the vicinity of a biasing device of an expansion valve according to a second embodiment. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing the vicinity of a biasing device of an expansion valve according to a third embodiment. [Diagram 5] FIG. 5 is an enlarged cross-sectional view showing the vicinity of a biasing device of an expansion valve according to a fourth embodiment. [Figure 6] FIG. 6 is an enlarged cross-sectional view showing the vicinity of a biasing device of an expansion valve according to a fifth embodiment. [Figure 7] FIG. 7 is an enlarged cross-sectional view showing the vicinity of a biasing device of an expansion valve according to a sixth embodiment. [Figure 8] FIG. 8 is a side view of the guide sleeve according to this embodiment, seen from the direction in which the groove is located. [Figure 9] FIG. 9 is a bottom view of the guide sleeve according to this embodiment. [Figure 10] FIG. 10 is an enlarged cross-sectional view showing the vicinity of a biasing device of an expansion valve according to a seventh embodiment. [Figure 11] FIG. 11 is a plan view of the spring receiving member according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0014] (Direction definition) In this specification, the direction from the valve disc 3 to the actuating rod 5 is defined as the "upward direction," and the direction from the actuating rod 5 to the valve disc 3 is defined as the "downward direction." Therefore, in this specification, regardless of the attitude of the expansion valve 1, the direction from the valve disc 3 to the actuating rod 5 is called the "upward direction."

[0015] (First embodiment) An overview of an expansion valve 1 in this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic cross-sectional view showing an example in which the expansion valve 1 in this embodiment is applied to a refrigerant circulation system 100. Figure 2 is an enlarged cross-sectional view showing the vicinity of an urging device in the expansion valve of Figure 1.

[0016] In this embodiment, the expansion valve 1 is fluidly connected to a compressor 101, a condenser 102, and an evaporator 104. The axis of the expansion valve 1 is designated as L.

[0017] In FIG. 1, an expansion valve 1 includes a valve body 2 having a valve chamber VS, a valve element 3, a biasing device 4, an actuating rod 5, and a power element 8.

[0018] The valve body 2 includes a valve chamber VS, as well as 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 a refrigerant (also referred to as a fluid) is supplied to the valve chamber VS via the supply-side flow path. The second flow path 22 is a discharge-side flow path (also referred to as an outlet-side flow path), and the fluid in the valve chamber VS is discharged to the outside of the expansion valve via a valve hole 27, the intermediate chamber 221, and the discharge-side flow path.

[0019] The first flow passage 21 and the valve chamber VS communicate with each other through a connection passage (inlet passage) 21a having a smaller diameter than the first flow passage 21. The valve chamber VS and the intermediate chamber 221 communicate with each other through the valve seat 20 and the valve through hole 27.

[0020] The actuating rod insertion hole 28 formed above the intermediate chamber 221 has the function of guiding the actuating rod 5, and a predetermined clearance is provided between the actuating rod 5 and the actuating rod insertion hole 28. The annular recess 29 formed above the actuating rod insertion hole 28 has the function of accommodating the ring spring 6. The ring spring 6 has multiple spring pieces abutting against the outer periphery of the actuating rod 5 to apply a predetermined biasing force.

[0021] The valve disc 3 is disposed in the valve chamber VS. When the valve disc 3 is seated on the valve seat 20 of the valve body 2, the flow of refrigerant through the valve hole 27 is restricted. This state is called a non-communicating state. However, even when the valve disc 3 is seated on the valve seat 20, a restricted amount of refrigerant may flow. On the other hand, when the valve disc 3 is separated from the valve seat 20, the flow of refrigerant passing through the valve hole 27 increases. This state is called a communicating state.

[0022] The actuating rod 5 is inserted into the valve through hole 27 with a gap required for the refrigerant to pass through. The lower end flat surface of the actuating rod 5 is in contact with the spherical upper surface of the valve body 3. The upper end of the actuating rod 5 is fitted into the lower end fitting hole of the stopper member 84 of the power element 8.

[0023] The actuating rod 5 can press the valve element 3 in the valve opening direction against the biasing force of the biasing device 4. When the actuating rod 5 moves downward, the valve element 3 moves away from the valve seat 20, and the expansion valve 1 is in the open state.

[0024] In FIG. 2, the biasing device 4 has a coil spring 41 formed by spirally winding a wire rod having a circular cross section, a valve body support 42, a spring receiving member 43, and a guide sleeve 44.

[0025] The valve body support 42 has a cylindrical shape with a top, formed by connecting a peripheral wall 42a and a top wall 42b. A short cylindrical portion 42c having a recess to which the spherical valve body 3 is welded is formed on the upper surface of the top wall 42b. The upper end of the coil spring 41 is surrounded by the peripheral wall 42a, and the upper end of the coil spring 41 abuts against the lower surface of the top wall 42b.

[0026] The spring receiving member 43 is formed by coaxially connecting a disk-shaped receiving body 43a and a circular tube portion 43b. The receiving body 43a has a male thread 43c on the outer periphery, and the spring receiving member 43 is attached to the valve body 2 by screwing the male thread 43c into a female thread 2d formed on the inner periphery of the open end of the circular opening 2c of the valve body 2, thereby forming a sealed valve chamber VS. With the spring receiving member 43 attached to the valve body 2, an O-ring OR is disposed between the circular tube portion 43b and the circular opening 2c to prevent the refrigerant from leaking from between the spring receiving member 43 and the circular opening 2c. An engagement hole 43d is formed on the lower surface of the spring receiving member 43 to engage a tool for rotating the spring receiving member 43.

[0027] The metal guide sleeve 44 has a cylindrical shape with a bottom, which is formed by connecting an enlarged diameter cylindrical portion 44a, a reduced diameter cylindrical portion 44b, and a bottom wall 44c. The outer diameter of the reduced diameter cylindrical portion 44b is approximately equal to the inner diameter of the circular tube portion 43b of the spring receiving member 43, and the inner diameter of the enlarged diameter cylindrical portion 44a is approximately equal to the outer diameter of the peripheral wall 42a of the valve body support 42. Furthermore, the height of the reduced diameter cylindrical portion 44b is approximately equal to the height of the circular tube portion 43b. The inner peripheral surface of the enlarged diameter cylindrical portion 44a and the outer peripheral surface of the peripheral wall 42a each constitute a sliding surface.

[0028] When the coil spring 41, which has a constant diameter over its entire length, is disposed inside the guide sleeve 44, the inner periphery of the reduced diameter cylindrical portion 44b directly faces the outer periphery of the coil spring 41, and the inner periphery of the expanded diameter cylindrical portion 44a faces the outer periphery of the coil spring 41 across the peripheral wall 42a of the valve body support 42. For this reason, the inner diameter of the expanded diameter cylindrical portion 44a is larger than the inner diameter of the reduced diameter cylindrical portion 44b by an amount equivalent to the thickness of the peripheral wall 42a.

[0029] A plurality of communication holes 44d that constitute a communication portion are formed along the circumferential direction in the enlarged diameter cylindrical portion 44a adjacent to the reduced diameter cylindrical portion 44b. The guide sleeve 44 may be made of, for example, a resin having high slidability.

[0030] When assembling the biasing device 4, the valve body 3 and the valve body support 42 are welded together in advance. First, the guide sleeve 44 is press-fitted into the spring receiving member 43. As a result, the outer periphery of the reduced diameter cylindrical portion 44b of the guide sleeve 44 is fitted into the inner periphery of the circular pipe portion 43b, and the lower surface of the bottom wall 44c abuts against the upper surface of the receiving body 43a.

[0031] Next, the coil spring 41 is placed inside the guide sleeve 44, and then the valve element support 42 joined to the valve element 3 is placed so as to cover the upper end of the coil spring 41, so that the peripheral wall 42a enters between the coil spring 41 and the expanded diameter cylindrical portion 44a. After the top wall 42b is abutted against the upper end of the coil spring 41 and the valve element support 42 is attached to the guide sleeve 44, the upper end of the expanded diameter cylindrical portion 44a is crimped (C) to reduce its diameter, thereby preventing the valve element support 42 and the guide sleeve 44 from being separated. The valve element support 42 and the guide sleeve 44 containing the coil spring 41 can be handled as a single unit whose parts do not come apart.

[0032] At this time, the outer periphery of the upper end of the coil spring 41 contacts the peripheral wall 42a, but the outer periphery of the lower end of the coil spring 41 does not contact the inner periphery of the reduced-diameter cylindrical portion 44b. However, the outer periphery of the lower end of the coil spring 41 may be made to contact the inner periphery of the reduced-diameter cylindrical portion 44b. A spring chamber SC that accommodates the coil spring 41 is formed by the peripheral wall 42a and top wall 42b of the valve body support 42, and the enlarged-diameter cylindrical portion 44a and the reduced-diameter cylindrical portion 44b and bottom wall 44c of the guide sleeve 44.

[0033] The biasing device 4 assembled as described above can be attached to the valve body 2 by screwing the male thread 43c into the female thread 2d so as to be coaxial with the axis L. The initial biasing force of the coil spring 41 can be adjusted by changing the amount of screwing between the male thread 43c and the female thread 2d. In the assembled state, the connection passage 21a faces the enlarged diameter cylindrical portion 44a of the guide sleeve 44. Furthermore, when the connection passage 21a is projected along the axis, it is preferable that the projected image overlaps at least a part of the communication hole 44d.

[0034] With the biasing device 4 attached, the valve body support 42 and the guide sleeve 44 can slide relative to each other in accordance with the movement of the valve body 3. Even when the valve body 3 is lifted to the maximum extent in the valve opening direction, the peripheral wall 42a of the valve body support 42 does not block the communication hole 44d.

[0035] In FIG. 1, the power element 8 has a plug 81, an upper cover member 82, a diaphragm 83, a receiving member 86, and a stopper member 84.

[0036] The opening at the top of the generally conical top cover member 82 can be sealed with a plug 81 .

[0037] The diaphragm 83 is made of a thin metal (for example, SUS) plate material on which a plurality of concentric circular projections and recesses are formed, and has approximately the same outer diameter as the outer diameters of the upper cover member 82 and the receiving member 86.

[0038] The receiving member 86 is formed, for example, by press-molding a metal plate, and is configured by connecting a flange portion and a hollow cylindrical portion.

[0039] The stopper member 84 is disposed between the upper cover member 82 and the receiving member 86 , and its upper surface is in contact with the center of the lower surface of the diaphragm 83 .

[0040] In assembling the power element 8, the stopper member 84 is placed between the diaphragm 83 and the receiving member 86, while the outer peripheries of the upper cover member 82, the diaphragm 83, and the receiving member 86 are overlapped and the outer peripheries are circumferentially welded together by, for example, TIG welding, laser welding, plasma welding, etc.

[0041] Next, a working gas is injected into the space surrounded by the upper cover member 82 and the diaphragm 83 (called the pressure actuated chamber PO) through an opening formed in the upper cover member 82, and then the opening is sealed with a plug 81, and the plug 81 is fixed to the upper cover member 82 using projection welding or the like.

[0042] When the power element 8 assembled as described above is attached to the valve body 2, the male thread 86a on the outer periphery of the lower end of the hollow cylindrical portion of the receiving member 86 is screwed into the female thread 2b formed on the inner periphery of the vertical hole 2a that communicates with the return flow path 23 of the valve body 2. When the male thread 86a of the receiving member 86 is screwed into the female thread 2b, the lower surface of the flange portion of the receiving member 86 comes into contact with the upper end surface of the valve body 2. This allows the power element 8 to be fixed to the valve body 2.

[0043] At this time, a packing PK is interposed between the power element 8 and the valve body 2 to prevent leakage of the refrigerant when the power element 8 is attached to the valve body 2. In this state, the lower space LS of the power element 8 communicates with the return flow path 23 via the vertical hole 2a.

[0044] (Expansion valve operation) An example of the operation of the expansion valve 1 will be described with reference to Fig. 1. The refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valve 1. The refrigerant adiabatically expanded by the expansion valve 1 is sent to the evaporator 104, where it is heat exchanged with the air flowing around the evaporator. The refrigerant returning from the evaporator 104 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return flow path 23). At this time, by passing through the evaporator 104, the fluid pressure of the return flow path 23 becomes smaller than the fluid pressure in the second flow path 22.

[0045] A high-pressure refrigerant is supplied to the expansion valve 1 from a condenser 102. More specifically, the high-pressure refrigerant from the condenser 102 is supplied to the valve chest VS via a first flow path 21.

[0046] When the valve element 3 is seated on the valve seat 20 (in a non-communicating state), the flow rate of the refrigerant sent from the valve chamber VS through the valve hole 27, the intermediate chamber 221, and the second flow path 22 to the evaporator 104 is restricted. On the other hand, when the valve element 3 is separated from the valve seat 20 (in a communicating state), the flow rate of the refrigerant sent from the valve chamber VS through the valve hole 27, the intermediate chamber 221, and the second flow path 22 to the evaporator 104 increases. The expansion valve 1 is switched between the closed state and the open state by the operating rod 5 connected to the power element 8 via the stopper member 84.

[0047] 1, a pressure actuated chamber PO and a lower space LS separated by a diaphragm 83 are provided inside the power element 8. Therefore, when the working gas in the pressure actuated chamber PO is liquefied, the diaphragm 83 and the stopper member 84 rise, and the working rod 5 moves upward in response to the biasing force of the coil spring 41. On the other hand, when the liquefied working gas is vaporized, the diaphragm 83 and the stopper member 84 are pressed downward, and the working rod 5 moves downward. In this way, the expansion valve 1 is switched between the open state and the closed state.

[0048] Furthermore, the lower space LS of the power element 8 is connected to the return flow path 23. Therefore, the volume of the working gas in the pressure actuated chamber PO changes depending on the temperature and pressure of the refrigerant flowing through the return flow path 23, and the actuating 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 to the evaporator 104 is automatically adjusted depending on the temperature and pressure of the refrigerant returning from the evaporator 104 to the expansion valve 1.

[0049] According to this embodiment, the valve disc support 42 is guided by the guide sleeve 44 fixed to the valve body 2, so that the valve disc 3 moves up and down accurately along the axis L. As a result, the gap between the valve disc 3 and the valve seat 20 changes very little when the valve is open, and the pressure that the valve disc 3 receives from the refrigerant flowing around the valve disc 3 can be made uniform. Even if the pressure of the refrigerant flowing around the valve disc 3 fluctuates due to disturbances or the like, the guide sleeve 44 prevents the valve disc 3 from moving in a direction perpendicular to the axis L, and valve disc vibration can be effectively suppressed.

[0050] Furthermore, according to this embodiment, the valve body support 42 slides against the guide sleeve 44 on the radially outer side of the coil spring 41, so that a relatively wide sliding area can be secured. This makes it possible to reduce the surface pressure on the sliding surface, suppressing defects such as galling, and realizing stable guiding of the valve body 3.

[0051] Furthermore, if the sliding surfaces of the guide sleeve and the valve body support are arranged radially inward of the coil spring as in the conventional technology, the diameter of the sliding surfaces becomes small. In contrast, the sliding surfaces of the coil spring 41 and the guide sleeve 44 in this embodiment are arranged radially outward of the coil spring, so that a larger diameter of the sliding surfaces can be ensured. If a larger diameter of the sliding surfaces can be ensured, the inclination of the valve body support 42 with respect to the axis can be effectively suppressed. This makes it possible to suppress the stiffness of the valve body support 42 against the guide sleeve 44 during sliding, and ensures smooth movement of the valve body 3.

[0052] Here, when the driving force of the power element 8 in the valve-opening direction (downward) is applied from the valve body 3 to the valve body support 42, if the valve body support 42 and the guide sleeve 44 contain the refrigerant (generally in a gas-liquid two-phase state) in a sealed state, a repulsive force will be generated due to the dashpot effect (damper effect) that will push the valve body support 42 back in the valve-closing direction, and there is a risk that the valve body 3 will not be able to open smoothly.

[0053] Therefore, in this embodiment, a communication hole 44d is provided in the guide sleeve 44, and when a driving force in the valve opening direction (downward) is transmitted to the valve element support 42, the refrigerant inside the valve element support 42 and the guide sleeve 44 flows out to the outside through the communication hole 44d. This suppresses the dashpot effect, and ensures a smooth valve opening operation of the valve element 3 in response to the transmission of the driving force from the power element 8. Furthermore, when the transmission of the driving force from the power element 8 is interrupted, the valve element support 42 is biased in the valve closing direction (upward) by the coil spring 41, but at this time, the external refrigerant enters the valve element support 42 and the guide sleeve 44 through the communication hole 44d, so that the upward movement of the valve element support 42 is not hindered, and a smooth valve closing operation of the valve element 3 can be ensured.

[0054] Second embodiment 3 is an enlarged cross-sectional view of the vicinity of the biasing device of the expansion valve according to the second embodiment. This embodiment differs from the first embodiment only in the shape of the valve body support 42A of the biasing device 4A. The other configurations are the same as those of the above-mentioned embodiments, so the same reference numerals are used and repeated explanations are omitted.

[0055] The valve disc support 42A is formed by connecting a peripheral wall 42Aa, a top wall 42Ab, and a valve disc portion 42Ac. The valve disc portion 42Ac has a generally cylindrical shape that protrudes upward from the upper surface of the top wall 42Ab along the axis L, and its upper end surface is spherical and abuts against the lower end surface of the actuation rod 5. The valve disc support 42A can be formed, for example, by cutting a single material.

[0056] In this embodiment as well, the valve element support 42A slides against the guide sleeve 44 on the radially outer side of the coil spring 41, so that stable guiding of the valve element 3 can be achieved. Moreover, according to this embodiment, the valve element support 42A in which the valve element and the valve element support are integrated is used, so that the valve element portion 42Ac can be formed coaxially with the peripheral wall 42Aa with high precision. Therefore, the valve element portion 42Ac can be seated on or separated from the valve seat 20 with high precision by the guidance of the guide sleeve 44. In addition, by integrating the valve element and the valve element support, the number of parts can be reduced, leading to cost reduction.

[0057] Third embodiment 4 is an enlarged cross-sectional view of the vicinity of the biasing device of the expansion valve according to the third embodiment. This embodiment differs from the first embodiment only in the shape of the valve body support 42B and the guide sleeve 44B of the biasing device 4B. The other configurations are the same as those of the above-mentioned embodiments, so the same reference numerals are used and repeated explanations are omitted.

[0058] The valve body support 42B is formed by connecting a peripheral wall 42Ba, a top wall 42Bb, and a short cylindrical portion 42Bc. The guide sleeve 44B has a cylindrical shape with a bottom, which is formed by connecting an equal-diameter cylindrical portion 44Ba, whose inner diameter is approximately equal to the outer diameter of the coil spring 41, and a bottom wall 44Bc. A communication hole 44Bd that constitutes a communication portion is formed in the equal-diameter cylindrical portion 44Ba. The inner diameter of the peripheral wall 42Ba of the valve body support 42B is approximately equal to the outer diameter of the equal-diameter cylindrical portion 44Ba. The inner peripheral surface of the peripheral wall 42Ba and the outer peripheral surface of the equal-diameter cylindrical portion 44Ba each constitute a sliding surface.

[0059] When assembling the biasing device 4B, the guide sleeve 44B is press-fitted into the spring receiving member 43, as in the above embodiment. Next, the coil spring 41 is placed inside the guide sleeve 44B, and then the valve body support 42B joined to the valve body 3 is moved toward the upper end of the coil spring 41, so that the inner periphery of the peripheral wall 42Ba fits into the outer periphery of the uniform diameter cylindrical portion 44Ba. When the biasing device 4B is assembled to the valve body 2 with the lower surface of the top wall 42Bb abutting against the upper end of the coil spring 41, the peripheral wall 42Ba is positioned opposite the connection passage 21a.

[0060] In the above-described embodiment, the outer periphery of the peripheral wall of the valve disc support is surrounded by the guide sleeve, so that the refrigerant flowing out from the connection passage 21a does not directly hit the valve disc support. In contrast, in this embodiment, the peripheral wall 42Ba is disposed outside the guide sleeve 44B and in a position facing the connection passage 21a, so that the refrigerant flowing out from the connection passage 21a directly hits the valve disc support 42B. This increases the sliding load between the valve disc support 42B and the guide sleeve 44B, and also suppresses rattling of the valve disc support 42B, which is also effective in reducing abnormal noise.

[0061] (Fourth embodiment) 5 is an enlarged cross-sectional view of the vicinity of the biasing device of the expansion valve according to the fourth embodiment. This embodiment differs from the first embodiment only in the shapes of the valve body support 42C and the guide sleeve 44C of the biasing device 4C. The other configurations are the same as those of the above-mentioned embodiments, so the same reference numerals are used and repeated explanations are omitted.

[0062] The valve body support 42C is formed by connecting a peripheral wall 42Ca having a longer axis length than the above-described embodiment, a top wall 42Cb, and a short cylindrical portion 42Cc. A plurality of communication holes 42Cd that constitute a communication portion are formed in the top wall 42Cb around the short cylindrical portion 42Cc, and extend parallel to the axis L so as to penetrate the top wall 42Cb.

[0063] The guide sleeve 44C has a cylindrical shape with a bottom, which is formed by connecting an enlarged diameter cylindrical portion 44Ca, a reduced diameter cylindrical portion 44Cb, and a bottom wall 44Cc, but does not have a communication hole.

[0064] According to this embodiment, since the guide sleeve 44C does not have a communication hole, the axial length of the peripheral wall 42Ca of the valve body support 42C can be secured to be long. This makes it possible to further increase the sliding area between the valve body support 42C and the guide sleeve 44C. In addition, when the valve body 3 moves up and down, the refrigerant moves between the inside and outside of the spring chamber SC via the communication hole 42Cd, so that the so-called dashpot effect can be suppressed.

[0065] Fifth embodiment 6 is an enlarged cross-sectional view of the biasing device of the expansion valve according to the fifth embodiment. This embodiment differs from the first embodiment only in the shape of a guide sleeve 44D of the biasing device 4D. The other configurations are the same as those of the above-mentioned embodiments, so the same reference numerals are used and repeated explanations are omitted.

[0066] The guide sleeve 44D is formed by connecting a constant diameter cylindrical portion 44Da and a flange portion 44Dc extending radially outward from the vicinity of the lower end of the constant diameter cylindrical portion 44Da. Above the flange portion 44Dc, the constant diameter cylindrical portion 44Da is formed with a communication hole 44Dd forming a communication portion. The outer diameter of the peripheral wall 42a of the valve body support 42 is approximately equal to the inner diameter of the constant diameter cylindrical portion 44Da.

[0067] The outer periphery of the lower end of the constant diameter cylindrical portion 44Da is fitted into the inner periphery of the upper end of the circular tube portion 43b of the spring receiving member 43 by press fitting or the like, and the lower surface of the flange portion 44Dc abuts against the upper end of the circular tube portion 43b. Since the upper end of the constant diameter cylindrical portion 44Da has a reduced diameter, the coil spring 41 does not slip out.

[0068] In this embodiment, by forming the guide sleeve 44D in a cylindrical shape, the amount of material and the number of processing steps can be reduced compared to the above-described embodiment, which contributes to cost reduction.

[0069] Sixth embodiment Fig. 7 is an enlarged cross-sectional view showing the vicinity of the biasing device of the expansion valve according to the sixth embodiment. Fig. 8 is a side view of the guide sleeve 44E according to this embodiment from the direction of the groove, and Fig. 9 is a bottom view of the guide sleeve 44E according to this embodiment.

[0070] This embodiment differs from the first embodiment only in the shape of a guide sleeve 44E of a biasing device 4E. Since the other configurations are the same as those in the above-described embodiment, the same reference numerals are used and repeated explanations are omitted.

[0071] The guide sleeve 44E has an enlarged cylindrical portion 44Ea, a reduced diameter cylindrical portion 44Eb, a bottom wall 44Ec, and an annular portion 44Ef protruding downward from the outer periphery of the bottom wall 44Ec. The reduced diameter cylindrical portion 44Eb has an outer longitudinal groove 44Eg extending along the axis L on its outer surface, and the bottom wall 44Ec has a central opening 44Ed.

[0072] When the reduced diameter cylindrical portion 44Eb is fitted into the circular pipe portion 43b of the spring receiving member 43, a communication passage PS1 surrounded by the circular pipe portion 43b and the outer vertical groove 44Eg is generated. Since the outer vertical groove 44Eg is exposed from the upper end of the circular pipe portion 43b, the communication passage PS1 communicates with the outside of the guide sleeve 44E via the upper end. The cross-sectional area of ​​the communication passage PS1 constituting the communication portion is smaller than the cross-sectional area of ​​the central opening 44Ed.

[0073] Furthermore, a communication passage PS2 is formed inside the annular portion 44Ef by abutting the lower end of the annular portion 44Ef against the upper surface of the receiving body 43a of the spring receiving member 43. The communication passage PS2 communicates with the spring chamber SC via a central opening 44Ed. A part of the circumferential direction of the annular portion 44Ef is cut out at a position connecting with the outer longitudinal groove 44Eg to form a notch 44Ei (see FIG. 9), and the communication passages PS1 and PS2 communicate with each other via the notch 44Ei.

[0074] According to this embodiment, since the guide sleeve 44E does not have a communication hole, the axial length of the peripheral wall 42a of the valve body support 42 can be secured to be long. This can further increase the sliding area between the valve body support 42 and the guide sleeve 44E. Furthermore, in response to the vertical movement of the valve body 3, the refrigerant moves between the inside and outside of the spring chamber SC via the communication passage PS1 in the outer vertical groove 44Eg of the guide sleeve 44E, the communication passage PS2 in the annular portion 44Ef, and the central opening 44Ed. This can suppress the dashpot effect and ensure smooth operation of the valve body 3.

[0075] Seventh embodiment Fig. 10 is an enlarged cross-sectional view showing the vicinity of the biasing device of the expansion valve according to the seventh embodiment. Fig. 11 is a plan view of a spring receiving member 43F according to this embodiment.

[0076] This embodiment differs from the first embodiment only in the shapes of a spring receiving member 43F and a guide sleeve 44F of a biasing device 4F. The other configurations are the same as those of the above-mentioned embodiment, so the same reference numerals are used and repeated explanations are omitted.

[0077] The spring receiving member 43F is formed by coaxially connecting a disk-shaped receiving body 43Fa and a circular tube portion 43Fb. An inner groove 43Fe is formed on the inner surface of the circular tube portion 43Fb, extending along the axis L and further along the upper surface of the receiving body 43Fa.

[0078] The guide sleeve 44F has an enlarged cylindrical portion 44Fa, a reduced diameter cylindrical portion 44Fb, a bottom wall 44Fc with a central opening 44Fd, and an annular portion 44Ff protruding downward from the outer periphery of the bottom wall 44Fc, but does not have an outer longitudinal groove.

[0079] When the reduced-diameter cylindrical portion 44Fb is fitted into the circular tube portion 43Fb of the spring receiving member 43F, a communication passage PS3 is formed that is surrounded by the reduced-diameter cylindrical portion 44Fb and the inner groove 43Fe. The cross-sectional area of ​​the communication passage PS3 that constitutes the communication portion is smaller than the cross-sectional area of ​​the central opening 44Fd.

[0080] Meanwhile, when the lower end of the annular portion 44Ff abuts against the upper surface of the receiving body 43Fa of the spring receiving member 43F, a communication passage PS4 is formed inside the annular portion 44Ff. An inner groove 44Fe formed in the receiving body 43Fa passes under the annular portion 44Ff and one end is open inside the communication passage PS3. The other end of the inner groove 44Fe is open at the upper end of the circular pipe portion 43Fb.

[0081] According to this embodiment, since the guide sleeve 44F does not have a communication hole, the axial length of the peripheral wall 42a of the valve body support 42 can be secured to be long. This can further increase the sliding area between the valve body support 42 and the guide sleeve 44F. Furthermore, as the valve body 3 moves up and down, the refrigerant moves between the inside and outside of the spring chamber SC through the communication passage PS3 in the inner groove 44Fe of the spring receiving member 43F, the communication passage PS4 in the annular portion 44Ff, and the central opening 44Fd. This can suppress the dashpot effect and ensure smooth operation of the valve body 3.

[0082] In the above embodiment, the guide sleeve and the spring receiving member are separate bodies, but they may be integrally formed from a single material.

[0083] It should be noted that the present invention is not limited to the above-described embodiment. Any of the components of the above-described embodiment may be modified within the scope of the present invention. Any of the components of the above-described embodiment may be added or omitted. [Explanation of symbols]

[0084] 1: Expansion valve 2: Valve body 3: Valve body 4~4F: Biasing device 5: Operating rod 6: Ring spring 8: Power Element 20: Valve seat 21: First flow path 22: Second flow path 23: Return flow path 27: Valve hole 41: Coil spring 42~42C: Valve body support 43, 43F: Spring support member 44, 44B~44F: Guide sleeve 100: Refrigerant circulation system 101: Compressor 102: Capacitor 104: Evaporator VS: Valve chamber

Claims

1. a valve body including a valve seat and a valve chamber; a valve body that restricts the passage of a fluid by being seated on the valve seat and allows the passage of the fluid by being separated from the valve seat; a biasing device that biases the valve body in a predetermined direction toward the valve seat, the biasing device includes a valve element support having a cylindrical shape with a top that supports the valve element, a coil spring that biases the valve element support in the predetermined direction, and a guide sleeve that is fixed to the valve body and guides the valve element support, the valve body support and the guide sleeve have sliding surfaces that slide around the coil spring, The valve body has a spring receiving member, The spring receiving member has a disk-shaped receiving body and a circular tube portion coaxially connected to the receiving body, The guide sleeve is a bottomed tubular member disposed within the circular tubular portion, A groove formed on the outer circumferential surface; an opening formed in a bottom wall, the opening communicating an internal space of the guide sleeve with the outside; an annular portion formed in a portion of the outer periphery of the outer end surface of the bottom wall other than the groove, extending from one end in the circumferential direction of the groove to the other end and extending to the receiving body; having a spring chamber for accommodating the coil spring is formed by the valve body support and the guide sleeve, and the fluid moves between the inside and outside of the spring chamber via a communication portion in response to movement of the valve body; The communication portion is a first communication passage surrounded by the circular pipe portion and the groove and communicating with the valve chamber; a second communication passage surrounded by the receiving body, the outer end surface of the guide sleeve, and the annular portion, the second communication passage communicating with both the first communication passage and the opening; An expansion valve comprising:

2. A valve body having a valve seat and a valve chamber; a valve body that restricts the passage of a fluid by being seated on the valve seat and allows the passage of the fluid by being separated from the valve seat; a biasing device that biases the valve body in a predetermined direction toward the valve seat, the biasing device includes a valve element support having a cylindrical shape with a top that supports the valve element, a coil spring that biases the valve element support in the predetermined direction, and a guide sleeve that is fixed to the valve body and guides the valve element support, the valve body support and the guide sleeve have sliding surfaces that slide around the coil spring, The valve body has a spring receiving member, The spring receiving member has a disk-shaped receiving body and a circular tube portion coaxially connected to the receiving body, and an inner groove is formed between the inner surface of the circular tube portion and the receiving body, The guide sleeve is a bottomed tubular member disposed within the circular tubular portion, an opening formed in a bottom wall, the opening communicating an internal space of the guide sleeve with the outside; an annular portion formed on the outer periphery of the outer end surface of the bottom wall and extending to the receiving body; having a spring chamber for accommodating the coil spring is formed by the valve body support and the guide sleeve, and the fluid moves between the inside and outside of the spring chamber via a communication portion in response to movement of the valve body; The communication portion is a first communication passage surrounded by the inner groove and the guide sleeve and communicating with the valve chamber; a second communication passage surrounded by the receiving body, the outer end surface of the guide sleeve, and the annular portion, the second communication passage communicating with both the first communication passage and the opening; An expansion valve comprising:

3. The valve body and the valve body support are integral with each other.

3. The expansion valve according to claim 1 or 2.

4. The inner periphery of the guide sleeve is fitted into the outer periphery of the valve body support. The expansion valve according to any one of claims 1 to 3.

5. The valve body support and the guide sleeve are inseparably connected with the coil spring contained therein.

5. The expansion valve according to claim 4.

6. The outer periphery of the guide sleeve is fitted into the inner periphery of the valve body support. The expansion valve according to any one of claims 1 to 3.

7. The outer circumferential surface of the valve body support faces an inflow path of a fluid entering the valve chamber.

7. The expansion valve according to claim 6.

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