JPH05203292A - Expansion valve corresponding to heat - Google Patents

Abstract

PURPOSE: To easily alter thermal response speed along with suitability for the control of a flow in a cooler. CONSTITUTION: This thermally responsive expansion valve for a cooler is provided with an actuator means containing a flow in a continuous passage path 46 and a hollow member 80 disposed in a heat exchange related system, a pressure responsive means which contains a fluid filled chamber 90 to move the actuator means responding to changes in the pressure of a fluid and a flow restricting means 92 to alter thermal response of a valve by reducing the communication of the fluid between the hollow member and the fluid filled chamber. This eases effect from a sharp temperature change of a return flow.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to expansion valves of the type used to control the flow of refrigerant fluid in air conditioning and cooling systems.

[0002]

2. Description of the Related Art Generally, in an air conditioner, particularly one used for cooling a passenger compartment of an automobile, an expansion valve compares the flow of a pressurized liquid refrigerant sent from a condenser with a relatively high pressure, thereby making a comparison. The low pressure stream to the evaporator,
Then it can be returned to the compressor. In particular, the expansion valve used to control the flow of liquid refrigerant to the evaporator in an automotive air conditioner is
A type of what is known as a "block" valve, a separate return flow passage that allows the vaporized refrigerant expelled from an evaporator to pass through it for thermal sensing and control of its temperature and pressure. On the valve body or block.

For example, it is known to provide an actuator rod for moving the expansion valve, exposing the rod to the refrigerant flowing in the return passage leading to the compressor, so that heat transfer can take place between them. Further, by utilizing the heat transfer through the rod to generate a temperature signal for activating the pressure responsive means connected to the actuator rod, the expansion valve of the expansion valve responds to the change in the temperature of the refrigerant discharged from the evaporator. It is also known to be able to control functions.

In order to move the valve actuator rod control member, it is known to provide a fluid filling chamber containing a pressurized fluid acting on a diaphragm which is a pressure response means, and a pressurized fluid is provided in a part of the rod. Is also known to be in charge of heat transfer to the refrigerant flowing through the return passage leading to the compressor inlet.

As shown in FIG. 7, a diaphragm 2 attached to a hollow tubular member 1 senses the pressure in a fluid filled chamber formed above the diaphragm by a capsule 3, and a hollow actuator rod causes a compressor return passage. It is known to provide a refrigerant expansion valve adapted to move a control valve member therethrough.

In this latter type of valve structure, the hollow actuator rod may undergo rapid changes in the sensed refrigerant temperature to rapidly change the pressure in the fluid fill chamber acting on the diaphragm. Abrupt changes in pressure within the fluid fill chamber produce corresponding changes in the flow of the control valve, resulting in over-controlled or unwanted oscillations in the refrigerant flow within the evaporator. This transient can be due to changes in engine speed, short-term changes in condenser or evaporator fan speed,
It is generated by the accumulated oil cascade in the evaporator.

The time constant for the change in the sensed temperature and the change in the pressure caused thereby is generally about 2 seconds until the final change, that is, 63% of the asymptotic limit is reached. However, in some devices it has been found necessary to lengthen the time constant to prevent the device from responding to such transients. A device requiring a long response time required a time constant of at least 5 seconds and at most about 40 seconds.

[0008]

In order to reduce or suppress the influence of the temperature transient phenomenon of the refrigerant discharged from the evaporator, in the conventional valve (see FIG. 7), the actuator rod is generally isolated by the jacket 4. Met. This technique is not sufficient to ensure that the desired effect of the controller is obtained, and in designs that allow mass production of valves for passenger car air conditioners, such isolation can result in time constants of 10 seconds or more. Difficulties have arisen in providing the desired response speeds needed.

For this reason, a thermostat-type refrigerant which is low-cost and easy to manufacture in which the thermal response speed can be easily changed so as to achieve a desired effect for controlling the flow in a cooling device such as an air conditioner of an automobile. An expansion valve was desired.

In view of such circumstances, it is an object of the present invention to provide a heat responsive expansion valve that is particularly suitable for controlling the flow of refrigerant fluid in a cooling or air conditioning system.

[0011]

[Means for Solving the Problems] and

In order to achieve the above object, the present invention is provided with a valve body having an inlet and an outlet and having a movable valve member so that the flow therebetween can be controlled, and the valve body is discharged from the evaporator of the apparatus to be compressed. An independent continuous passage, which is connected so that the refrigerant returned to the inlet flows, penetrates through the valve body.

The actuator for moving the valve member includes a rod penetrating the return passage and forming a hollow portion in the rod. The tip of the rod is connected to a pressure responsive diaphragm that is exposed to fluid pressure inside the fluid fill chamber outside the valve body. The hollow portion inside the rod is in fluid communication with the fluid inside the chamber. The actuator rod is in heat transfer or heat transfer relationship with the refrigerant return flow through the continuous passage. The fluid in the rod changes the pressure of the fluid in the fluid fill chamber in response to changes in the temperature of the refrigerant flow in the return passage.
Therefore, the pressure of the fluid in the chamber acts on the diaphragm to move the valve actuator rod operatively connected to the diaphragm.

In one embodiment, the flow restricting means comprises a hollow tubular member forming a flow regulating orifice, in another embodiment a plug forming the flow regulating orifice, and in another embodiment a porous plug. The actuator rod is provided in the hollow portion of the actuator rod so that the flow of the fluid acting on the diaphragm into the chamber can be reduced. The flow rate adjusting orifice slows down the fluid flow to the fluid filling chamber,
As a result, it has a function of slowing down the pressure change inside the valve, and prevents the valve from responding to the transient change in the temperature of the refrigerant discharged from the evaporator.

Another feature of the invention is that it is simple to manufacture, facilitates sealing of the pressure responsive diaphragm and actuator rod, and is preferably a common weld welded plug or tube to the diaphragm and actuator. A flow rate adjusting orifice is formed in the member.

As shown in FIG. 7, in a general refrigerant filling device, a part of the concentrated refrigerant is retained in the hollow end by a screen or a spiral spring 5 provided in the open end of the hollow portion. ing. In the absorbent filling device, a screen is used to hold the absorbent material in the hollow portion.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The valve assembly 10 shown in FIG. 1 has a valve body 12 with an outlet passage 14, which is connected by a flange 18 formed in the tube and compressing a seal 20. The tubular conduit 16 is inserted. Conduit 16
It is connected to send a reduced pressure stream to the refrigerant evaporator. The outlet passage 14 communicates with an inner hole 15 that communicates with the valve seat 22. Movable valve member 24 is provided correspondingly and is generally spherical in shape. The valve seat and passage 15 communicates with an inlet chamber 26 formed by an inner hole 28 at the end of the valve body 12, which inner hole
28 is closed by a plug 30 screwed to the body. A hollow portion 32 is formed in the plug, and a spring 34 having a cap 36 aligned at the upper end is housed in the hollow portion,
The cap abuts the valve member 24 and biases the valve member to a closed position abutting the valve seat 22.

The valve chamber 26 also communicates in an intersecting manner with an inlet passage 38 into which a conduit 40 fits, preferably by a flange 42 formed therein abutting a seal 44. It can be sealed in the entrance passage 38. The conduit 16 is connected to deliver a reduced pressure stream to the refrigerant evaporator. The inlet conduit 40 is connected to receive relatively high pressure refrigerant from the outlet of the refrigerant condenser.

During valve calibration, the spring 34 can be compressed by rotating the plug 30 to apply the desired preload to the spherical valve member 24. The screw is an anerobic (anero
bic) It can be sealed by any suitable technique such as a sealant.

Another through passage 46 is formed in the valve body 12 at one end of which a tube or conduit 48 is attached,
A flange 50 formed around 48 is pressed against seal 52 to allow the conduit to be sealed within passageway 46. The conduit 48 is adapted to be connected to the inlet of the compressor of the cooling device, which receives the superheated vaporized refrigerant discharged from the evaporator. Pipe or conduit at the other end of passage 46
A flange 56 attached to the conduit and provided on the conduit compresses a seal 58 provided around the end of the passage 46.

The conduit 54 is connected to the suction inlet / outlet side port of the refrigerant evaporator. Conduit 54, 16 is flange 5
The valve body 12 has a shape that can be brought into contact with the valve 6 and 18.
It is retained on the valve body by a retainer 60 which can be secured to them by suitable tightening means such as screws 62 which are screwed onto. Similarly, the conduits 48, 40 are held in place by a retainer 64 which is shaped to abut the flanges 50, 42 and which can be secured thereto by any suitable fastening means such as a screw 66 threaded onto the valve body 12. Is held.

The thermoresponsive actuator means 68 is provided with a concave annular lower shell portion 70 mounted on the valve body 12. In the embodiment shown in FIG. 1, the shell 70 is fixed by the folding flange 72 made of the main body material.
A thin annular flexible diaphragm, preferably made of a metallic material, is sealed around the lower shell 70 and intermediate the periphery of the upper shell or cover 76. The upper and lower shells and diaphragms are laser welded, resistance welded,
Sealed and joined by suitable welding such as brazing.

An actuator rod means 78 is attached to the diaphragm 74, and a hollow tubular member provided in this means is slidably accommodated in an inner hole 82 formed in the valve body 12, and The hole 82 extends upward and opens inside the shell 70 below the diaphragm 74. Inner hole
82 extends downward and intersects a small diameter passage 84 communicating with the outlet passage 14, and a pin 86 is slidably accommodated in the small diameter passage 84. The pin 86 operates upon downward movement of the tubular member 80 to contact the spherical valve member 24 and disengage it from the valve seat.

The hollow interior 88 of the rod 80 has a flow restricting means 92.
Through the inside of the shell 76 above the diaphragm 74. As is known, the chamber 90 and the hollow interior 88 of the rod 80 are filled with a pressurized fluid such as a refrigerant or silicone oil in which a liquid phase and a gas phase are mixed. The change in temperature of the refrigerant flow through passage 46 causes the pressure in hollow portion 88 of rod 80 to increase or decrease, thereby changing the pressure in chamber 90 above diaphragm 74.

The flow restricting means 92 of the embodiment of FIG. 1 has a flow regulating orifice 94 formed in a plug 96 mounted through an opening 98 penetrating the diaphragm 74. As a presently preferred example, in the case of a valve structure in which the diaphragm is on a “neutral plane” and the filling pressure is about 4 atm, the ratio of the volume of the chamber 90 to the volume of the hollow portion 88 is about 4: 1. , Orifice 94 size 0.005-0.010 inch (0.
13 to 2.5 mm).

The plug is sealed and fixed to the end of the actuator rod 80 by a suitable means such as welding. An annular backing plate 99 is provided on the back surface of the diaphragm 74 so as to surround the opening 98. A washer 97 is provided on the upper surface of the diaphragm 74. Part of the plug 96
The plate 99, the diaphragm opening 98 and the washer 97 are extended to extend upward to facilitate the sealing and fixing thereof. As the presently preferred example, the sealing and fixing of the plug 96 to the diaphragm 74, the plate 99 and the washer 97 is performed by common welding such as laser, resistance or electron beam welding. However, it should be understood that the weld may be made with a suitable filler material such as, for example, a hard solder or a weld material. The plug 96 is provided with a flange or large diameter portion 95 that forms a shoulder aligned with the backside of the plate 99.

FIG. 2 shows a modified embodiment of the limiting plug 95 'and its attachment to the rod 80. The plug 95 of the embodiment of FIG. 2 is assembled to the diaphragm backing plate and the diaphragm as in the case of FIG. However, the plug 95 'is provided with a pilot portion 100 extending downwardly into the hollow interior 88 of the rod 80,
Positioning and welding to it is facilitated.

FIG. 3 shows a modified embodiment of the structure of the hollow actuator rod 80 ', in which a lower diaphragm backing plate 99' is fitted to a shoulder 102 formed on the upper portion of the rod 80 '. .. In the embodiment of FIG. 3, the limiting plug 104 is the hollow interior 8 of the actuator rod 80 '.
It is fitted in the 8'and is fixed therein by welding common to the welding of the backing plates 99 ', 97' on the small diameter portion 106 of the actuator rod 80 '.

FIG. 4 shows a modified embodiment of the actuator rod / diaphragm assembly in which the rod 108 is integrally formed with the lower diaphragm backing plate 110 by, for example, the deep drawing method. The diaphragm is provided with an upper backing ring 112 which secures the diaphragm to the lower backing plate by common welding to the lower backing plate. The limiting means in the embodiment of FIG. 4 comprises a porous plug, eg a powder metal plug, mounted within the hollow interior 116 of the rod 108.

FIG. 5 shows another embodiment similar to that shown in FIG. 4, in which the actuator rod 108 'is formed separately from the lower backing plate 110'. It is fixed to it by welding. In the embodiment of FIG. 5, a restricted orifice 118 is formed in the lower diaphragm backing plate, which is secured to the plate by a ring 112 'in the same manner as the embodiment of FIG.

FIG. 6 shows another embodiment of the present invention in which a threaded collar 171 for screwing with the valve body is integrally formed with the lower shell 170. Diaphragm 174
Are attached to the peripheral portion of the lower shell 170.
The cover 176 and the outer edge of the cover are attached to the periphery of the lower shell 170 by suitable welding similar to the construction of the embodiment of FIG. A deep-drawn cup portion 200, which is integrally formed from a central opening in the diaphragm, fits into the central portion of the lower backing plate 199, closing the lower edge of the cup portion 200 and closing the hollow interior 188. Is forming.

The upper diaphragm backing plate 197 of FIG. 6 is also provided with a deep drawn central cup portion 201 which fits tightly into the hollow interior 188 and has a restricted orifice 194 formed at the lower end. The upper diaphragm backing plate 197 and the lower plate 199 are fixed to the diaphragm by common welding. A jacket or guide bush 202 covers the outer surface of the deep-draw cup portion 200, which covers the cup inside the valve body.
It is sized to guide 200 movements.

Thus, the present invention provides a unique construction of a thermally responsive refrigerant expansion valve whose temperature is sensed by a thermally conductive hollow valve actuation rod extending through a refrigerant return passage back to the compressor. There is. The hollow rod communicates with a fluid pressure chamber that acts on the power diaphragm. By communicating between the two chambers through the restricted orifice, the effects of thermal transients within the device can be mitigated and the valve's response to such transients can be virtually eliminated.

In various embodiments, the restriction orifice is formed by providing a plug at the upper end of a hollow valve actuating rod, and various structures are provided for commonly affixing the rod and plug to the color diaphragm by common welding. Have been described. In another embodiment, the hollow actuation rod is formed by a deep draw cup welded to or integrally formed with the lower diaphragm backing plate.

Although the preferred embodiment of the present invention has been described above, the scope of the claims is limited and various modifications can be made within the scope.

[0035]

According to the present invention, the flow control means for reducing the fluid communication between the hollow member and the fluid filling chamber, which are arranged in heat exchange relation with the flow in the continuous passage, is provided. Can be easily changed, the pressure change in the hollow portion can be slowed down, the influence of the rapid temperature change of the return flow can be mitigated, and the valve response to the thermal transient phenomenon in the apparatus can be almost eliminated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a block-type refrigerant expansion valve embodying the principles of the present invention.

FIG. 2 is a partially enlarged view of the modified embodiment of FIG.

FIG. 3 is a partially enlarged view of a further modified embodiment of FIG.

FIG. 4 is a partially enlarged view showing another embodiment of the present invention similar to FIG.

5 is a partially enlarged view showing another embodiment of the present invention similar to FIG.

FIG. 6 is a perspective view of a part of the valve of FIG. 1 according to the present invention with a hollow tubular member forming a flow rate adjusting orifice, broken away.

FIG. 7 is a perspective view showing a conventional example in the same format as FIG.

[Explanation of symbols]

 12 Valve body 14 Outlet passage 24 Valve member 38 Inlet passage 46 Continuous flow passage 80 Actuator rod 90 Internal chamber 92 Flow restricting means

 ─────────────────────────────────────────────────── ————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————— US through Eligible Sites, Inc. Golf Road-Number 115 1803

Claims (14)

[Claims] 1. A heat-responsive expansion valve for a cooling device, comprising: (a) an inlet (38) and an outlet (14), wherein a valve member (24) moves inside and between the inlet and the outlet. A valve body (12) for controlling the flow, (b) a continuous flow passage (46) penetrating the valve body, and (c) arranged in a heat exchange relationship with the flow in the continuous flow passage. A hollow member (80), the actuator member having the hollow member filled with a thermally activated fluid whose pressure changes with temperature, and (d) the chamber (90) filled with the fluid, and the pressure of the fluid. Pressure responsive means for actuating to move the actuator means in response to a change in, and (e) actuate to reduce fluid communication between the hollow member (80) and the fluid filled chamber (90), A flow restricting means (92) for changing the thermal response of the valve. 2. The flow restricting means has a flow regulating orifice (94) in the hollow member.
Expansion valve. 3. The expansion valve according to claim 1, wherein the flow restricting means comprises a porous plug (114). 4. The actuator means comprises a thin flexible annular diaphragm (114) sealed between two annular members, the member forming a restriction orifice being inserted through said annular member and diaphragm. The expansion valve according to claim 1, wherein the expansion valve is sealed and fixed. 5. The expansion valve according to claim 1, wherein the flow restricting means includes a plug provided with a flow rate adjusting orifice, and the plug is attached to one end of the hollow member. 6. The expansion valve of claim 1, wherein the fluid comprises a mixture of gas and liquid and the flow restriction means comprises a flow regulating orifice. 7. The hollow member has a tube closed at one end, and the flow restricting means has a plug (100, 104) provided with a flow regulating orifice (94 ′). 2. The expansion valve of claim 1, wherein the expansion valve is fitted into the end of the tube opposite the closed end. 8. The actuator member comprises a tubular member closed at one end, and the flow restricting means comprises a plug provided with a flow regulating orifice, at least a portion of the plug being the tubular member. 2. The expansion valve according to claim 1, wherein the expansion valve is fitted into and sealed at an end opposite to the closed end of the. 9. The pressure response means has a diaphragm made of a metal material, and the pressure response means, the hollow member and the flow restricting means are sealed and fixed by welding. Expansion valve. 10. The expansion valve according to claim 1, wherein the flow restricting means includes a tubular member, a portion of which is fitted in the hollow member, and a flow control orifice is formed at one end of the tubular member. .. 11. The flow restricting means includes a tubular member having a small diameter portion fitted in a hollow member and having a flow rate adjusting orifice at one end thereof, the large diameter portion provided in the tubular member being a fluid. The expansion valve according to claim 1, wherein the expansion valve extends into the filling chamber and is attached to the pressure responsive means. 12. A method of manufacturing a thermo-responsive expansion valve, comprising: (a) providing a valve block having a continuous passage through which a thermally conductive fluid flows, and (b) providing a fluid filled cavity on one side. A response type diaphragm is provided, (c) a hollow valve actuator member is arranged in the continuous passage, and (d) a restriction member penetrating a flow rate adjusting orifice is provided, and the restriction member, the diaphragm and the actuator member are sealed. , Carrying out common fixing and positioning. 13. The method of claim 12, wherein the steps of jointly performing sealing, fixing and positioning include holding and fixing by welding. 14. The method of claim 12, wherein the steps of jointly performing sealing, fixing and positioning include holding and fixing by brazing.