JP7165972B2 - expansion valve - Google Patents

Description

The present invention relates to expansion valves.

2. Description of the Related Art Conventionally, in a refrigerating cycle used for an air conditioner or the like mounted on an automobile, a temperature-sensitive expansion valve that adjusts the amount of refrigerant passing according to the temperature is used in order to save installation space and piping.

In this type of thermal expansion valve, the operating rod is inserted into the through hole of the valve body and moves in the axial direction. is inherently gapped. However, when the through-hole communicates with two flow paths having a fluid pressure difference, there is a risk that the refrigerant may leak from the high-pressure side flow path to the low-pressure side flow path through the gap. There is Therefore, in Patent Document 1, an O-ring is provided between the actuating rod and the through hole to prevent shortcut of the refrigerant.

JP 2014-126280 A

By the way, since the O-ring is also subjected to the pressure difference between the high-pressure side flow path and the low-pressure side flow path, it is relatively displaced in the axial direction of the operating rod and comes out of the through hole, thereby shortcutting the refrigerant. There is a risk of inviting Therefore, in the above patent document, a snap ring is provided on the operating rod to prevent the O-ring from coming off.

However, although this snap ring is provided for the sole purpose of preventing the O-ring from coming off, there is a demand for more effective use of space. On the other hand, there is also a demand to reduce the noise of expansion valves.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an improved expansion valve capable of achieving low noise while effectively utilizing space.

In order to achieve the above object, the expansion valve according to the present invention
a valve body disposed in the flow path through which the fluid passes and having an annular valve seat;
a valve body that prevents passage of the fluid by being seated on the valve seat and permits passage of the fluid by being separated from the valve seat;
a coil spring that biases the valve body toward the valve seat;
an actuating rod having a concave portion on its outer periphery and having one end in contact with the valve body;
The valve body includes a through hole that communicates between a high-pressure flow path and a low-pressure flow path having a lower fluid pressure than the high-pressure flow path, and the operating rod is inserted through the through-hole,
The annular elastic body fitted to the outer circumference of the operating rod is in contact with the inner circumference of the through hole over the entire circumference,
An anti-vibration spring that holds the annular elastic body and suppresses vibration of the operating rod is provided between the operating rod and the through hole,
The anti-vibration spring has an annular base that engages with the recess of the operating rod, and a plurality of legs that extend from the annular base and contact the through holes.

ADVANTAGE OF THE INVENTION By this invention, the improved expansion valve which can implement|achieve low noise can be provided, effectively using space.

FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 of the first embodiment is applied to a refrigerant circulation system. FIG. 2 is a vertical sectional view showing the power element 8 in an exploded manner. 3 is a perspective view of the pressing member 85. FIG. FIG. 4 is a perspective view showing the operating rod anti-vibration spring 6. FIG. FIG. 5 is a perspective view showing an operating rod anti-vibration spring 6A according to a modification. FIG. 6 is a perspective view showing the biasing device anti-vibration spring 44. As shown in FIG. FIG. 7 is a longitudinal sectional view of an expansion valve 1A according to the second embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

(definition of direction)
In this specification, the direction from the valve body 3 to the operating rod 5 is defined as "upward direction", and the direction from the operating rod 5 to the valve body 3 is defined as "downward direction". Therefore, in this specification, the direction from the valve body 3 toward the operating rod 5 is referred to as the "upward direction" regardless of the orientation of the expansion valve 1 .

(First embodiment)
An overview of the expansion valve 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 of this embodiment is applied to a refrigerant circulation system 100. As shown in FIG. In this example, expansion valve 1 is fluidly connected to compressor 101 , condenser 102 and evaporator 104 .

The expansion valve 1 includes a valve body 2 having a valve chamber VS, a valve body 3, an urging device 4, an operating rod 5, a ring spring 6, and a power element 8. Let L be the axis of the expansion valve 1 .

The valve body 2 includes a first flow path 21, a second flow path 22 and a return flow path 23 in addition to the valve chamber VS. The first flow path 21 is a supply-side flow path, and refrigerant (also referred to as fluid) is supplied to the valve chamber VS through the supply-side flow path. The second flow path 22 is a discharge side flow path, and the fluid in the valve chamber VS is discharged to the outside of the expansion valve through the operating rod insertion hole 27 and the discharge side flow path. The first flow path 21 and the valve chamber VS are communicated with each other by a connection path 21a having a diameter smaller than that of the first flow path 21 .

The valve body 3 is arranged in the valve chamber VS. When the valve body 3 is seated on the annular valve seat 20 of the valve body 2, the first flow path 21 and the second flow path 22 are in a non-communication state. On the other hand, when the valve body 3 is separated from the valve seat 20, the first channel 21 and the second channel 22 are in communication.

The lower end of the operating rod 5 inserted through the operating rod insertion hole 27 with a gap is in contact with the upper surface of the valve body 3 . Further, 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 is separated from the valve seat 20 and the expansion valve 1 is opened.
The operating rod 5 passes power from the valve body 3 along the axis L through an operating rod insertion hole 27 coaxially formed in the valve body 2, a central hole 28, an annular portion 26, a return passage 23, and a communication passage 2b. It extends to element 8. The inner diameter of the annular portion 26 is larger than the inner diameter of the central hole 28 that slidably holds the operating rod 5 . The central hole 28 and the annular portion 26 constitute a through hole that communicates the second flow path 22 and the return flow path 23 . Both the second flow path 22 and the return flow path 23 are positioned on the low-pressure side in the refrigeration cycle, but the pressure in the former is relatively high because the refrigerant passes through the evaporator 104 and suffers pressure loss. Therefore, in this specification, the second flow path 22 may be referred to as a high-pressure flow path, and the return flow path 23 may be referred to as a low-pressure flow path.

Next, the power element 8 will be explained. The power element 8 is attached to a recess 2 a provided at the top of the valve body 2 . The recess 2a communicates with a return passage 23 in the valve body 2 through which the refrigerant from the evaporator 104 passes through the communication passage 2b.

FIG. 2 is a vertical sectional view showing the power element 8 in an exploded manner. The axis of the power element is indicated by X.

In FIG. 2 , the power element 8 has a plug 81 , an upper lid member 82 , a diaphragm 83 , a stopper member 84 , a pressing member 85 and a receiving member 86 .

The upper lid member 82 has a central conical portion 82a and an annular flange portion 82b extending from the lower end of the conical portion 82a to the outer circumference. An opening 82c is formed at the top of the conical portion 82a and can be sealed with a plug 81. As shown in FIG.

The diaphragm 83 is made of a thin plate having a plurality of concentric concave and convex shapes, and has an outer diameter substantially the same as the outer diameter of the flange portion 82b.

The stopper member 84 has a disc portion 84a and a cylindrical portion 84b coaxially joined to the lower surface of the disc portion 84a. A fitting hole 84c is formed in the center of the lower end of the cylindrical portion 84b. The outer diameter of the cylindrical portion 84b is φ1, which is smaller than the outer diameter of the disk portion 84a.

3 is a perspective view of the pressing member 85. FIG. In FIG. 3, the pressing member 85 is formed by press-molding a metal plate, and includes an annular base portion 85a and eight claw portions 85b provided at equal intervals on the inner periphery of the base portion 85a. have. However, the number of claw portions 85b is not limited to eight.

The claw portion 85b is bent in an L shape and its tip extends along the axis X. As shown in FIG. A protruding portion 85c protruding in a hemispherical shape toward the axis X side is formed in the vicinity of the tip of each claw portion 85b.

2, the receiving member 86 includes a flange portion 86a having an outer diameter substantially the same as the outer diameter of the flange portion 82b of the upper lid member 82, a stepped portion 86c having an annular support surface 86b substantially perpendicular to the axis X, and a hollow portion. and a cylindrical portion 86d. The inner diameter φ2 of the hollow cylindrical portion 86d is larger than the outer diameter φ1 of the cylindrical portion 84b. A stepped portion 86c connects the inner periphery of the flange portion 86a and the upper end of the hollow cylindrical portion 86d.

Next, the procedure for assembling the power element 8 will be described. First, the base portion 85a of the pressing member 85 is welded to the supporting surface 86b of the receiving member 86 while the claw portion 85b of the pressing member 85 is accommodated in the hollow cylindrical portion 86d of the receiving member 86 . Next, the upper cover member 82, the diaphragm 83, the stopper member 84, and the receiving member 86 are arranged so as to have the positional relationship shown in FIG. At this time, due to the elastic force of each claw portion 85b of the pressing member 85 attached to the receiving member 86, the protruding portion 85c is urged to come into contact with the outer circumference of the cylindrical portion 84b of the stopper member 84. As shown in FIG.

Furthermore, in a state in which the outer peripheral portions of the flange portion 82b of the upper lid member 82, the diaphragm 83, and the flange portion 86a of the receiving member 86 are overlapped, the outer peripheral portions are circumferentially welded by TIG welding, laser welding, plasma welding, or the like. and unify. A case is composed of the upper cover member 82 and the receiving member 86 .

Subsequently, after a working gas is sealed from an opening 82c formed in the upper lid member 82 into a space (referred to as a pressure actuation chamber PA) surrounded by the upper lid member 82 and the diaphragm 83, the opening 82c is sealed with a plug 81. Then, the stopper 81 is fixed to the upper cover member 82 by projection welding or the like.

At this time, the working gas enclosed in the pressure actuation chamber PA causes the diaphragm 83 to receive pressure in such a manner as to protrude toward the receiving member 86 . It is supported in contact with the upper surface of the member 84 . Since the disk portion 84a of the stopper member 84 is held by the support surface 86b of the receiving member 86 via the pressing member 85, the stopper member 84 does not slip out of the power element 8.

When assembling the power element 8 to the valve main body 2, the upper end of the operating rod 5 to which the operating rod vibration isolating spring 6 (to be described later) is assembled is fitted into the fitting hole 84c of the stopper member 84, and the operating rod 5 is moved. While being inserted into the valve body 2 , the hollow cylindrical portion 86 d of the receiving member 86 is fitted into the recess 2 a of the valve body 2 . Further, the power element 8 is fixed to the valve body 2 using a fastening member or caulking (not shown). In this state, the lower space LS of the power element 8 communicates with the return channel 23, that is, has the same internal pressure.

Next, the O-ring OR1, which is an annular elastic body fitted to the operating rod 5, and the operating rod anti-vibration spring 6 will be described. The O-ring OR1 is installed in the annular portion 26 of the valve body 2 in FIG. The inner periphery of the O-ring OR1 is in contact with the outer periphery of the operating rod 5 over the entire periphery, and the outer periphery of the O-ring OR1 is in contact with the inner periphery of the annular portion 26 over the entire periphery. A circumferential groove (recess) 5a is formed in the outer circumference of the operating rod 5 above the O-ring OR1. It is preferable that the width of the circumferential groove 5a is larger than the plate thickness of the operating rod anti-vibration spring 6. As shown in FIG. As a material for the O-ring OR1, resin, silicon rubber, or the like can be appropriately used. Further, the annular elastic body is not limited to the O-ring, and any material that can be fitted around the outer periphery of the operating rod 5 to seal the annular portion 26 can be used. Furthermore, the concave portion is not limited to a circumferential groove, and may be a depression or a hole.

FIG. 4 is a perspective view showing the operating rod anti-vibration spring 6 of this embodiment. The operating rod anti-vibration spring 6 has an annular base 61, eight legs 62, and four engaging pieces 64 (only three are shown in FIG. 4), and is made of elastic material such as stainless steel or its alloys. It can be formed by press molding from a plate material with Let O be the axis of the operating rod anti-vibration spring 6 . The number of legs 62 is not limited to eight, and the number of engaging pieces 64 is not limited to four.

The annular base 61 is an annular plate-shaped member that forms the bottom of the operating rod anti-vibration spring 6 and has a mounting hole 63 in the center with an inner diameter substantially equal to the outer diameter of the operating rod 5 . Engagement pieces (engagement portions) 64 arranged at regular intervals in the circumferential direction are connected to the inner circumference of the mounting hole 63 . The engaging piece 64 is bent in the same direction as the leg portion 62 with respect to the annular base 61 .

Each leg portion 62 radially extends from the outer peripheral side of the annular base 61 with the same length and is provided at equal angular intervals. Each leg 62 is bent in a substantially L shape at an angle θ less than a right angle with respect to the annular base 61, and has a hemispherically protruding portion 65 protruding outward in the vicinity of the tip.

When assembling the operating rod anti-vibration spring 6 to the operating rod 5, when the chamfered upper end of the operating rod 5 (FIG. 1) is brought close to the operating rod anti-vibration spring 6 and pushed into the mounting hole 63 from below in FIG. Since the engaging piece 64 is elastically deformed, the operating rod 5 can enter the mounting hole 63 . When the operating rod 5 is pushed further from this state, when the engaging piece 64 finally reaches the circumferential groove 5a, the engaging piece 64 recovers from elastic deformation and engages with the circumferential groove 5a. becomes. At this time, it is preferable that the lower surface of the annular base 61 is in contact with the upper surface of the O-ring OR1.

The inner diameter of the communication passage 2b of the valve body 2 is larger than the minimum outer diameter of the operating rod vibration isolation spring 6. As shown in FIG. Therefore, with the O-ring OR1 arranged in the annular portion 26, the operating rod 5, to which the operating rod vibration isolation spring 6 is assembled, is moved from above the valve body 2 through the communication passage 2b, the return passage 23, the annular portion 26, Through the central hole 28 , the operating rod anti-vibration spring 6 can be arranged in the annular portion 26 . At this time, a predetermined pressing force is applied from the raised portion 65 to the inner circumference of the annular portion 26 .

FIG. 5 is a perspective view showing an operating rod anti-vibration spring 6A according to a modification. This example differs from the embodiment of FIG. 4 in that the engagement piece 64 is not provided, and instead, a slit 66 extending radially from the inner circumference to the outer circumference is provided in the annular base 61. The point is that a portion of the annular base 61 in the circumferential direction is discontinuous. In this example, the inner diameter of the mounting hole 63 is smaller than the outer diameter of the operating rod 5 in the free state. In this modified example, the attachment hole 63 constitutes an engaging portion. Since other configurations are the same as those of the above-described embodiment, redundant description is omitted by assigning the same reference numerals.

According to this example, when the operating rod vibration isolation spring 6 is assembled to the operating rod 5, the upper end of the operating rod 5 is moved from below in FIG. It is brought close to the bar vibration isolation spring 6 and pushed into the mounting hole 63 . When the mounting hole 63 reaches the circumferential groove 5a, the mounting hole 63 is engaged with the circumferential groove 5a by restoring the annular base 61 from the elastic deformation.

Next, the biasing device 4 will be described. In FIG. 1 , the biasing device 4 includes a coil spring 41 formed by spirally winding a circular wire, a valve body support 42 attached to the upper end of the coil spring 41 to support the valve body 3 , and the lower end of the coil spring 41 . and a biasing device anti-vibration spring 44. The spring receiving member 43 has the function of sealing the valve chamber VS of the valve body 2 and supporting the end of the coil spring 41 that biases the valve body 3 toward the valve seat 20 .

The spherical valve body 3 is welded to the upper surface of the valve body support 42, and both are integrated.

FIG. 6 is a perspective view showing the biasing device anti-vibration spring 44. As shown in FIG. The biasing device anti-vibration spring 44 has a base portion 44a and leg portions 44b, and can be formed by press-molding an elastic plate material such as stainless steel or its alloy.

The base portion 44a is an annular plate-like member that forms the upper portion of the biasing device vibration isolating spring 44, and has a mounting hole 44c in the center. The base portion 44a is attached so as to be sandwiched between the valve support 42 and the upper end of the coil spring 41 with a portion of the valve support 42 (FIG. 1) inserted into the mounting hole 44c.

A plurality of leg portions 44b extend radially from the outer peripheral side of the base portion 44a. Here, eight leg portions 44b of the same length are provided at equal angular intervals. Each leg portion 44b is bent into a substantially L shape at an angle less than a right angle with respect to the base portion 44a, and has a hemispherically protruding portion 44d protruding outward in the vicinity of the tip.

The raised portion 44d elastically contacts the upper inner wall of the valve chamber VS when the urging device 4 is installed in the valve chamber VS. is set so as not to enter the connection path 21a.

(Operation of expansion valve)
An operation example of the expansion valve 1 will be described with reference to FIG. 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 delivered to the evaporator 104, where it exchanges heat 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 passage 23). At this time, by passing through the evaporator 104 , the fluid pressure in the second flow path 22 becomes higher than the fluid pressure in the return flow path 23 .

The expansion valve 1 is supplied with high-pressure refrigerant from a condenser 102 . More specifically, the high pressure refrigerant from the condenser 102 is supplied to the valve chamber VS through the first flow path 21 .

When the valve body 3 is seated on the valve seat 20 (in other words, when the expansion valve 1 is closed), the first flow path 21 on the upstream side of the valve chamber VS and the downstream side of the valve chamber VS is in a non-communication state with the second flow path 22 of . On the other hand, when the valve body 3 is separated from the valve seat 20 (in other words, when the expansion valve 1 is open), the refrigerant supplied to the valve chamber VS flows through the operating rod insertion hole 27 and the second 2 flow path 22 to the evaporator 104 . Switching between the closed state and the open state of the expansion valve 1 is performed by an operating rod 5 connected to a power element 8 .

In FIG. 1, inside the power element 8, a pressure actuation chamber PA and a lower space LS, which are partitioned by a diaphragm 83, are provided. Therefore, when the working gas in the pressure working chamber PA is liquefied, the working rod 5 moves upward, and when the liquefied working gas is vaporized, the working rod 5 moves downward. Thus, the expansion valve 1 is switched between the open state and the closed state.

Furthermore, the lower space LS of the power element 8 communicates with the return channel 23 . Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the pressure working chamber PA changes according to the temperature and pressure of the refrigerant flowing through the return passage 23, and the working 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 104 is automatically adjusted according to the temperature and pressure of the refrigerant returning from the evaporator 104 to the expansion valve 1. adjusted.

According to this embodiment, the gap between the operating rod 5 and the annular portion 26 is sealed by the O-ring OR1 provided in the annular portion 26 that communicates the second flow passage 22 and the return flow passage 23. , the shortcut of the refrigerant from the second channel 22 to the return channel 23 can be prevented. In addition, even when the operating rod 5 makes repeated strokes, the axial relative displacement of the O-ring OR1 with respect to the operating rod 5 can be prevented.

Also, the high-pressure refrigerant fed into the first flow path 21 of the expansion valve 1 may undergo pressure fluctuation (pulsation) due to the operation of the compressor 101, which may cause the valve body 3 to vibrate and generate abnormal noise. be. In contrast, according to the present embodiment, the protuberances 65 of the operating rod anti-vibration springs 6 and 6A abut on the inner periphery of the annular portion 26, thereby imparting a predetermined sliding resistance to the operating rod 5 in the driving direction. Vibration of the valve body 3 can be effectively suppressed via the operating rod 5 by arranging the operating rod anti-vibration springs 6 and 6A.

In this way, by making the operating rod anti-vibration springs 6 and 6A have both the function of holding the O-ring OR1 and the function of suppressing the vibration of the operating rod 5, it is possible to effectively utilize the space.

Further, when the valve body 3 moves in the opening/closing direction (vertical direction), the biasing device anti-vibration spring 44 moves together with the valve body 3 and the valve body support 42 . At this time, since the biasing device vibration-isolating spring 44 presses the inner wall of the valve chamber VS of the valve body 2 with a predetermined force, when the biasing device vibration-isolating spring 44 slides, the raised portion of the leg portion 44b A frictional force is generated between 44d and the inner wall of the valve chamber VS. As a result, the valve body 3 and the valve body support 42 do not react sensitively in the vertical direction to pressure fluctuations of the high-pressure refrigerant from the connection path 21a, and vibration in the vertical direction can be prevented or reduced. Furthermore, since the biasing device vibration isolating spring 44 is pressed against the inner wall surface of the valve chamber VS by the plurality of legs 44b at a plurality of locations, the valve body 3 Inadvertent movement of the valve body support 42 in the direction intersecting the axis L against the pressing force is suppressed, and the effect of preventing vibration in this direction is exhibited. The urging device anti-vibration spring 44 also has a function of guiding the vertical movement of the valve body 3 and the valve body support 42 .

Also, when the air conditioner is turned off, the pressure in the return flow path 23 may temporarily rise above the pressure actuation chamber PA of the power element 8 . In such a case, the diaphragm 83 is urged in a direction away from the stopper member 84 by the pressure in the return flow path 23, and a gap is generated between the diaphragm 83 and the stopper member 84, resulting in a free state. be. At this time, if vibration is imparted to the expansion valve 1 from the outside, the stopper member 84 may vibrate finely within the range of the gap, generating abnormal noise.

On the other hand, according to the present embodiment, the holding member 85 is provided in the power element 8, and the raised portion 85c of the claw portion 85b abuts against the outer periphery of the stopper member 84. Therefore, the sliding resistance is caused by the frictional force thereof. , the vibration of the stopper member 84 can be suppressed and abnormal noise can be reduced even in the free state.

In addition, since the stopper member 84 is connected to the actuating rod 5, the protrusion 85c of the claw portion 85b of the pressing member 85 abuts against the outer circumference of the stopper member 84, thereby suppressing the vibration of the stopper member 84, thereby suppressing the movement of the actuating rod. Vibration of 5 and valve body 3 can also be suppressed.

(Second embodiment)
FIG. 7 is a diagram showing an expansion valve 1A according to the second embodiment. Regarding this embodiment, only the parts that are different from the first embodiment will be described, and the same reference numerals will be given to the common configurations, and redundant description will be omitted.

In this embodiment, the pressing member is omitted from the power element 8 and the biasing device anti-vibration spring is omitted from the biasing device 4 . Depending on the specifications of the refrigerant circulation system 100, the vibration of the valve body 3 may be small and the abnormal noise of the power element 8 may be low. Cost reduction can be achieved by using it.

It should be noted that the present invention is not limited to the above-described embodiments. Variations of any of the components of the above-described embodiments are possible within the scope of the invention. Also, arbitrary components can be added or omitted in the above-described embodiments.

1, 1A: Expansion valve 2: Valve body 3: Valve body 4: Biasing device 5: Operating rods 6, 6A: Operating rod anti-vibration spring 8: Power element 20: Valve seat 21: First flow path 22: Second Flow path 23 : Return flow path 26 : Annular portion 27 : Operating rod insertion hole 41 : Coil spring 42 : Valve body support 43 : Spring receiving member 44 : Biasing device anti-vibration spring 100 : Refrigerant circulation system 101 : Compressor 102 : Condenser 104: Evaporator VS: Valve chamber OR1: O-ring

Claims (4)

a valve body disposed in the flow path through which the fluid passes and having an annular valve seat;
a valve body that prevents passage of the fluid by being seated on the valve seat and permits passage of the fluid by being separated from the valve seat;
a coil spring that biases the valve body toward the valve seat;
an actuating rod having a concave portion on its outer periphery and having one end in contact with the valve body;
The valve body includes a through hole that communicates between a high-pressure flow path and a low-pressure flow path having a lower fluid pressure than the high-pressure flow path, and the operating rod is inserted through the through-hole,
The annular elastic body fitted to the outer circumference of the operating rod is in contact with the inner circumference of the through hole over the entire circumference,
An anti-vibration spring that holds the annular elastic body and suppresses vibration of the operating rod is provided between the operating rod and the through hole,
The anti-vibration spring has an annular base that engages with the recess of the operating rod, and a plurality of legs that extend from the annular base and contact the through holes.
An expansion valve characterized by: The concave portion of the operating rod is a circumferential groove, and the annular base of the anti-vibration spring has an engaging portion that engages with the circumferential groove.
The expansion valve according to claim 1, characterized in that: The concave portion of the operating rod is a circumferential groove, and the annular base of the anti-vibration spring is elastically deformable and partially discontinuous in the circumferential direction.
The expansion valve according to claim 1, characterized in that: The leg extends from the inner circumference of the annular base and is bent, and a part of the leg protrudes to form a protuberance, and the protuberance is the inner peripheral surface of the through hole. abut the
The expansion valve according to any one of claims 1 to 3, characterized in that:

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