JP7483250B2 - Expansion valve - Google Patents

Description

The present invention relates to an expansion valve.

In refrigeration cycle systems used in vehicle air conditioners, etc., a temperature-sensing expansion valve is used to adjust the amount of refrigerant passing through depending on the temperature in order to reduce installation space and piping. A typical expansion valve controls the flow rate of refrigerant supplied from the refrigerant inlet side to the refrigerant outlet side by opening and closing the valve body by driving a power element. The driving force of the power element is also transmitted to the valve body inside the valve body via the operating rod.

However, in conventional expansion valves, the refrigerant passing through the orifice passes through a refrigerant flow path that is bent like a crank, which can impede the smooth flow of the refrigerant and cause abnormal noise. In addition, because the actuating rod and the valve body are connected in series, there is also the problem that the valve body becomes longer along the axial direction of the actuating rod.

In response to this, Patent Document 1 discloses an expansion valve having a valve body with a first port that communicates with the receiver side, a second port that is arranged in series with the first port and faces the evaporator, and a valve body that is movable in the axial direction of the port. With this expansion valve, the first and second ports are arranged in series, so that smooth refrigerant flow is ensured and the generation of abnormal noise can be suppressed. In addition, because the moving direction of the valve body and the moving direction of the actuating rod that drives the valve body are perpendicular to each other, the length of the valve body along the axial direction of the actuating rod can be suppressed.

Patent No. 4812427

The expansion valve of Patent Document 1 has a first cam surface formed at the tip of the actuating rod, and a second cam surface formed on the valve body that abuts against the first cam surface. When the actuating rod moves in the axial direction and the first cam surface presses against the second cam surface, the valve body can move in a direction perpendicular to the axis of the actuating rod.

Here, in order to transmit the movement of the actuating rod to the valve body with high accuracy, the first and second cam surfaces must be formed with high accuracy, which increases manufacturing costs. In addition, friction between the first and second cam surfaces may prevent the valve body from moving smoothly. Furthermore, because the actuating rod is positioned so as to intersect with the return flow path of the valve body, the refrigerant flowing through the return flow path may hit the actuating rod, which may cause Karman vortices that cause abnormal noise.

The present invention aims to provide an expansion valve that ensures smooth fluid flow within the valve body and precise movement of the valve disc.

In order to achieve the above object, the expansion valve according to the present invention comprises:
a valve body including a first flow passage and a second flow passage connected along a first axis, and a valve seat formed coaxially between the first flow passage and the second flow passage;
a passive member movably disposed within the valve body;
a valve body attached to the passive member and capable of being seated on the valve seat;
a power element attached to the valve body;
an actuating member for transmitting a driving force from the power element to the passive member along a second axis;
The first axis and the second axis are parallel to each other ,
The valve body has a base and a cover attached to the base, and the power element is disposed between the base and the cover,
The cover has a hollow cylindrical portion that fits into a part of the passive member.
The expansion valve according to the present invention comprises:
a valve body including a first flow passage and a second flow passage connected along a first axis, and a valve seat formed coaxially between the first flow passage and the second flow passage;
a passive member movably disposed within the valve body;
a valve body attached to the passive member and capable of being seated on the valve seat;
a power element attached to the valve body;
an actuating member for transmitting a driving force from the power element to the passive member along a second axis;
The first axis and the second axis are parallel to each other,
The valve body has a base and a cover attached to the base, and the power element is disposed between the base and the cover,
the base body has a guide portion that guides the movement of the passive member,
The cover has a hollow cylindrical portion that fits into a part of the passive member.
The expansion valve according to the present invention comprises:
a valve body including a first flow passage and a second flow passage connected along a first axis, and a valve seat formed coaxially between the first flow passage and the second flow passage;
a passive member movably disposed within the valve body;
a valve body attached to the passive member and capable of being seated on the valve seat;
a power element attached to the valve body;
an actuating member for transmitting a driving force from the power element to the passive member along a second axis;
The first axis and the second axis are parallel to each other,
The valve body has a third flow passage parallel to the first flow passage and the second flow passage and on an opposite side to the first flow passage and the second flow passage with the power element therebetween .

The present invention provides an expansion valve that ensures smooth fluid flow within the valve body and precise movement of the valve element.

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 refrigeration cycle system. FIG. 2 is a cutaway perspective view of the expansion valve according to the present embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the axial direction of the power element is designated as L.

(Overview of the expansion valve)
An overview of an expansion valve 1 according to the present embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing an example in which the expansion valve 1 according to the present embodiment is applied to a refrigeration cycle system 100. Fig. 2 is a perspective cut-away view showing the expansion valve according to the present embodiment.

In this embodiment, the expansion valve 1 is connected to a compressor 101, a condenser 102, and an evaporator 104, which together form a refrigerant cycle system 100.

The expansion valve 1 comprises a valve body 2, a valve body (ball) 3, a biasing device 4, an actuating rod (actuating member) 5, and a power element 8.

The valve body 2 has a base 200 and a cover 210. The rectangular parallelepiped base 200 has a large diameter opening 201 in the shape of a blind hole. The bottom surface 202 side of the large diameter opening 201 has an elliptical cross-sectional shape, and the rest of the large diameter opening 201 has a circular cross-sectional shape. A hollow cylindrical guide portion 203 is formed on the bottom surface 202 of the large diameter opening 201. A valve chamber VC is formed inside the guide portion 203. The valve chamber VC is connected to the second flow path 22.

The roughly cylindrical lid 210 has a disk portion 211 that fits into the large-diameter opening 201, and a hollow cylinder portion 212 that protrudes from one side of the disk portion 211. An O-ring OR1 is placed in a circumferential groove formed on the outer periphery of the disk portion 211, sealing the gap between the disk portion 211 and the large-diameter opening 201.

The hollow cylindrical portion 212 is formed to face the guide portion 203 at a position offset from the axis of the disk portion 211. A cylindrical first flow path 21 is formed coaxially with the hollow cylindrical portion 212 on the surface of the disk portion 211 opposite to the surface on which the hollow cylindrical portion 212 is provided (the upper surface in FIG. 2).

The lid 210 also has a threaded hole 204 formed in parallel with the first flow path 21. A cylindrical adjustment member 220 with a male thread formed on its outer periphery is attached to the threaded hole 204 so that it can be screwed into it.

The biasing device 4, which is disposed near the bottom surface 202 of the large-diameter opening 201, has a coil spring 41 made of a circular wire wound in a spiral shape, and a passive member 42. The passive member 42 has a generally elongated cylindrical shape with a driven part 421 and a driving part 422 arranged side by side.

The driven part 421 forms a recess 423 facing the bottom surface 202 of the large diameter opening 201, and the coil spring 41 is housed in the recess 423. It is preferable that the coil spring 41 is arranged so that its center is aligned with the power element 8 described later.

The drive unit 422 has a fitting hole 424 that fits into the guide unit 203 with a clearance fit, and a cylindrical support unit 425 with a top that protrudes toward the lid 210 coaxially with the fitting hole 424. An O-ring OR3 is placed in a circumferential groove formed on the outer periphery of the guide unit 203, sealing the gap between the fitting hole 424 and the guide unit 203.

The valve body 3 is fixed by welding to a conical recess formed in the center of the top wall of the support part 425, and multiple communication holes 426 are formed around the periphery of the valve body 3.

The support part 425 fits into the lower end side of the hollow cylindrical part 212 of the lid body 210. An O-ring OR2 is placed in a circumferential groove formed on the outer periphery of the support part 425, sealing the space between the support part 425 and the inner periphery of the hollow cylindrical part 212.

The hollow cylindrical portion 212 has a partition wall 215, and a small opening 216 is formed in the center of the partition wall 215. A valve seat 217 is formed at the end of the small opening 216 on the valve body 3 side.

An element chamber EC, which is a cylindrical space, is formed between the disk portion 211 of the lid body 210 and the driven portion 421 of the passive member 42, and the power element 8 and the actuating rod 5 are arranged in the element chamber EC.

The power element 8 has a structure in which the outer periphery of a cover member 82, a diaphragm 83, and a receiving member 84 are fixed by welding, and a working gas is injected from an injection hole into the space PO formed by the cover member 82 and the diaphragm 83 and sealed by a plug 81. A stopper member 85 is disposed in the space LS between the diaphragm 83 and the receiving member 84 so as to contact the diaphragm 83. The protruding end of the operating rod 5 inserted into the blind hole of the stopper member 85 abuts against the driven part 421. The operating rod 5 can be omitted, in which case the stopper member 85 becomes the operating member.

In the base 200, a return flow path (third flow path) 23 is formed on the opposite side of the power element 8 from the second flow path 22. The return flow path 23 and the element chamber EC are connected via a communication passage 24. The communication passage 24 is formed at an angle so that the refrigerant flowing through the return flow path 23 can easily flow in.

In the valve body 2 in which the base body 200 and the cover body 210 are assembled, the first flow path 21 is, for example, a supply side flow path, and a refrigerant (also called a fluid) is supplied to the valve chamber VC through the supply side flow path. The second flow path 22 is, for example, a discharge side flow path, and the fluid in the valve chamber VC is discharged to the outside of the expansion valve through the second flow path 22. The first flow path 21 and the valve chamber VC are connected by a small opening 216. As shown in FIG. 1, the first flow path 21, the small opening 216, the valve seat 217, the valve chamber VC, and the second flow path 22 have a common axis (first axis) O parallel to the axis (second axis) L.

When the valve disc 3 arranged in the valve chamber VC is seated on the annular valve seat 217, the first flow path 21 and the second flow path 22 are not in communication. However, even when the valve disc 3 is seated on the valve seat 217, a limited amount of refrigerant may pass through. On the other hand, when the valve disc 3 is separated from the valve seat 217, the first flow path 21 and the second flow path 22 are in communication. Figures 1 and 2 show the state in which the valve disc 3 is separated from the valve seat 217.

The actuating rod 5, whose protruding end abuts against the opposing surface of the driven portion 421, can press the passive member 42 along the axis L in the valve opening direction in which the valve body 3 opens, against the biasing force of the coil spring 41. When the actuating rod 5 moves in the valve opening direction, the valve body 3 moves away from the valve seat 217 along the common axis O, and the expansion valve 1 opens. The stroke (movable range) of the actuating rod 5 corresponds to the maximum lift amount of the valve body 3.

(Assembly of expansion valve)
The passive member 42 with the coil spring 41 housed in the recess 423 is attached to the large diameter opening 201 of the base 200 , and the inner periphery of the fitting hole 424 is fitted onto the outer periphery of the guide portion 203 .

Then, the power element 8 with the actuating rod 5 and stopper member 85 assembled thereto is inserted into the large diameter opening 201, the protruding end of the actuating rod 5 is brought into contact with the opposing surface of the driven part 421 of the passive member 42, and the disk part 211 of the lid body 210 is fitted into the large diameter opening 201. At this time, the inner periphery of the tip of the hollow cylindrical part 212 is fitted into the outer periphery of the support part 425, thereby positioning the base body 200 and the lid body 210. In this state, the base body 200 and the lid body 210 are fixed together using a fastening means (not shown).

By screwing the adjustment member 220 that is screwed into the screw hole 204 of the cover body 210, the pressing force that the adjustment member 220 applies to the end of the power element 8 can be changed. This makes it possible to adjust the amount of movement of the working rod 5 in response to the pressure of the working gas.

(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 passes through the expansion valve 1 (more specifically, the return flow path 23) and is returned to the compressor 101 side.

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

When the valve body 3 is seated on the valve seat 217 (in other words, when the expansion valve 1 is closed), the first flow path 21 on the upstream side of the valve chamber VC and the second flow path 22 on the downstream side of the valve chamber VC are not in communication. On the other hand, when the valve body 3 is separated from the valve seat 217 (in other words, when the expansion valve 1 is open), the refrigerant supplied to the valve chamber VC is sent through the second flow path 22 to the evaporator 104. The expansion valve 1 is switched between the closed and open states by the actuating rod 5 connected to the power element 8.

The diaphragm 83 of the power element 8 is connected to one end of the actuating rod 5 via a stopper member 85. Therefore, when the working gas in the space PO is liquefied, contraction occurs, and the actuating rod 5 moves in a direction approaching the power element 8, whereby the passive member 42 is displaced in the same direction while being guided by the guide portion 203 due to the biasing force of the coil spring 41, and the valve body 3 seats on the valve seat 217. This restricts the flow of refrigerant from the first flow path 21 side toward the valve chamber VC.

On the other hand, when the working gas in the liquefied space PO is vaporized, expansion occurs, and the working rod 5 moves in a direction away from the power element 8 to transmit a driving force to the passive member 42, which displaces the passive member 42 in the same direction against the biasing force of the coil spring 41, and the valve body 3 moves away from the valve seat 217. This allows the flow of refrigerant from the first flow path 21 side toward the valve chamber VC through the small opening 216 and the communication hole 426. In this way, the expansion valve 1 is switched between the open and closed states.

A portion of the refrigerant flowing through the return flow path 23 enters the element chamber EC and the space LS of the power element 8 via the communication passage 24. As a result, the phase (gas phase, liquid phase, etc.) of the working gas in the space LS changes depending on the temperature and pressure of the refrigerant flowing through the return flow path 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 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.

In this embodiment, the first flow path 21, the small opening 216, the valve chamber VC, and the second flow path 22 are arranged in a straight line along the common axis O, which allows the refrigerant to flow smoothly through them and suppresses the generation of abnormal noise.

In addition, since the power element 8 is disposed in the element chamber EC inside the valve body 2, it is isolated from the external environment, and the working gas in the space PO is mainly affected by the temperature and pressure of the refrigerant flowing through the return flow path 23, thereby ensuring precise operation of the working rod 5. In particular, by forming the part that forms the inner wall of the element chamber EC from a highly insulating material (e.g., resin), the environment within the element chamber EC can be effectively isolated from the external environment, ensuring even more precise operation of the working rod 5.

Furthermore, in this embodiment, the movement direction (axis L) of the actuating rod 5 and the movement direction (common axis O) of the valve body 3 are parallel, so there is no need to provide a drive direction conversion means, which generally has a complex structure and is prone to friction, and the smooth movement of the valve body 3 can be ensured and the expansion valve 1 can be manufactured at low cost. In addition, since the movement amount of the actuating rod 5 is equal to the movement amount of the valve body 3, the power element 8 can be easily adjusted using the adjustment member 220.

In addition, since there are no protruding parts in the return flow path 23 of the expansion valve 1, the refrigerant flows smoothly through the return flow path 23 and does not generate Karman vortexes that can cause abnormal noise.

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.

1: Expansion valve 2: Valve body 200: Base body 210: Cover body 3: Valve body 4: Urging device 5: Actuating rod 8: Power element 217: Valve seat 21: First flow path 22: Second flow path 23: Return flow path 41: Coil spring 42: Passive member 100: Refrigerant cycle system 101: Compressor 102: Condenser 104: Evaporator VC: Valve chamber EC: Element chamber

Claims (8)

a valve body including a first flow passage and a second flow passage connected along a first axis, and a valve seat formed coaxially between the first flow passage and the second flow passage;
a passive member movably disposed within the valve body;
a valve body attached to the passive member and capable of being seated on the valve seat;
a power element attached to the valve body;
an actuating member for transmitting a driving force from the power element to the passive member along a second axis;
The first axis and the second axis are parallel to each other ,
The valve body has a base and a cover attached to the base, and the power element is disposed between the base and the cover,
The cover body has a hollow cylindrical portion that fits into a part of the passive member.
An expansion valve characterized by: a valve body including a first flow passage and a second flow passage connected along a first axis, and a valve seat formed coaxially between the first flow passage and the second flow passage;
a passive member movably disposed within the valve body;
a valve body attached to the passive member and capable of being seated on the valve seat;
a power element attached to the valve body;
an actuating member for transmitting a driving force from the power element to the passive member along a second axis;
The first axis and the second axis are parallel to each other,
The valve body has a base and a cover attached to the base, and the power element is disposed between the base and the cover,
the base body has a guide portion that guides the movement of the passive member,
The cover body has a hollow cylindrical portion that fits into a part of the passive member.
An expansion valve characterized by: The cover has a screw hole into which an adjustment member that abuts against the power element is screwed.
3. The expansion valve according to claim 1 or 2 . a valve body including a first flow passage and a second flow passage connected along a first axis, and a valve seat formed coaxially between the first flow passage and the second flow passage;
a passive member movably disposed within the valve body;
a valve body attached to the passive member and capable of being seated on the valve seat;
a power element attached to the valve body;
an actuating member for transmitting a driving force from the power element to the passive member along a second axis;
The first axis and the second axis are parallel to each other,
The valve body has a third flow path parallel to the first flow path and the second flow path, the third flow path being on an opposite side to the first flow path and the second flow path across the power element.
An expansion valve characterized by: The valve body has a base and a cover attached to the base, and the power element is disposed between the base and the cover.
5. The expansion valve according to claim 4 ,. The base body has a guide portion that guides the movement of the passive member.
6. The expansion valve according to claim 5 ,. The cover body has a hollow cylindrical portion that fits into a part of the passive member.
7. The expansion valve according to claim 5 or 6.. The cover has a screw hole into which an adjustment member that abuts against the power element is screwed.
The expansion valve according to any one of claims 5 to 7..

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