JPH0525272U - Expansion valve - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide an expansion valve capable of completely muffling the foam noise generated in the expansion valve. A throttle portion 17 having a small flow passage area formed between a refrigerant inlet 11 to which a high-pressure liquid refrigerant is supplied and a refrigerant outlet 12 connected to an inlet of an evaporator, and a refrigerant gas exiting the evaporator. Diaphragm 25 which is displaced by the temperature fluctuation of
And a valve body 21 that operates according to the displacement of the diaphragm 25 to open and close the throttle portion 17, so as to surround the throttle portion 17 near the throttle portion 17 on the refrigerant outlet 12 side. The cylindrical porous member 35 disposed in the above is provided, and the communication passage 37 for communicating the throttle portion 17 and the refrigerant outlet 12 without passing through the hole formed in the porous member 35.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an expansion valve that is used in a vehicle air conditioner or the like and controls the flow rate of a refrigerant entering an evaporator.

[0002]

[Prior Art]

 In recent years, the quietness in the passenger compartment of passenger cars has been remarkably improved, and there is an increasing need to suppress the generation of sound to a minimum.

However, in the expansion valve of the cooling device, when the refrigerant liquid expands to form bubbles in which the liquid and the gas are mixed and flows into the evaporator, a sound (hereinafter, “ "Bubbling sound" occurs.

Therefore, conventionally, a muffler that separates a foamy refrigerant into a liquid portion and a gas portion to muffle the noise is disposed between the throttle portion in which the refrigerant liquid expands and the evaporator inlet, and is installed in the evaporator. It suppresses the foaming noise that occurs before the refrigerant enters (Jikaihei 3-558).

[0005]

[Problems to be solved by the device]

 The expansion valve, which has a muffler between the throttle and the inlet of the evaporator, has a much smaller bubble noise than the previous one.

However, bubbles are generated in the throttle portion where adiabatic expansion is performed, and the bubble noise generated between the throttle portion and the silencer passes through the space in which the valve operating mechanism is arranged and the like to the diaphragm chamber. It leaked to the outside and was still one of the noise sources.

[0007] Therefore, an object of the present invention is to provide an expansion valve that can more completely muffle the foam noise generated in the expansion valve.

[0008]

[Means for Solving the Problems]

 To achieve the above object, the expansion valve of the present invention has a small flow passage area formed between a refrigerant inlet to which a high-pressure liquid refrigerant is supplied and a refrigerant outlet connected to an evaporator inlet. In an expansion valve provided with a throttle portion, a diaphragm that is displaced by the temperature fluctuations of the refrigerant gas that exits the evaporator, and a valve body that operates according to the displacement of the diaphragm to open and close the throttle portion, close to the throttle portion. Then, the cylindrical porous member arranged so as to surround the throttle portion on the refrigerant outlet side and the communication that connects the throttle portion and the refrigerant outlet without passing through the hole formed in the porous member. It is characterized by having a passage.

[0009]

[Action]

 The bubbles generated by the adiabatic expansion of the refrigerant passing through the constricted portion have a liquid portion passing through the porous member and a gas portion passing through the communication passage due to the resistance of the porous member. Therefore, the bubbles are then separated into the liquid portion and the gas portion and disappear, and the bubble noise is not generated.

In the present invention, the porous member is formed in a tubular shape surrounding the throttle portion and is arranged close to the throttle portion while ensuring a flow passage area. Therefore, the distance from the bubble generating portion (throttle portion) to the bubble disappearing portion is significantly shortened, and the generation of bubble noise is significantly suppressed.

[0011]

【Example】

 An embodiment will be described with reference to the drawings. FIG. 1 shows an expansion valve used in a vehicle air conditioner, 11 is a refrigerant inlet connected to a refrigerant tank (not shown) to supply a high-pressure liquid refrigerant, and 12 is not shown It is a refrigerant outlet connected to the inlet of the evaporator. The base 13 having the refrigerant inlet 11 is fixed to the valve body 14 having the refrigerant outlet 12 by caulking, and an O-ring 15 for sealing is interposed therebetween.

The mouthpiece 13 has a front half portion 13a formed in a cylindrical shape having a small outer diameter, and a small-diameter throttle hole 17 is formed at a tip portion thereof. Therefore, the liquid refrigerant that has entered from the refrigerant inlet 11 passes through the throttle holes 17 having a small flow passage area and adiabatically expands there to become a foamy body in which liquid and gas are mixed.

The base of the throttle hole 17 on the side of the refrigerant inlet 11 is a valve seat, and the ball-shaped valve body 21 is pressed against it by the compression coil spring 22 to close the throttle hole 17. Reference numeral 23 is an adjustment nut for adjusting the spring pressure of the compression coil spring 22.

At the upper end of the valve body 14, a diaphragm chamber 26 is formed, which is divided into two parts by a diaphragm 25 that is displaceable in the direction perpendicular to the surface. The high pressure chamber 27 of the diaphragm chamber 26 is connected by a capillary tube 28 to a temperature sensing cylinder (not shown) provided on the outlet side of the evaporator. The temperature sensing tube senses the temperature of the refrigerant gas that exits the evaporator, and a small amount of refrigerant is sealed in the capillary tube 28. Therefore, the pressure in the high pressure chamber 27 of the diaphragm chamber 26 changes in accordance with the fluctuation of the temperature of the refrigerant gas leaving the evaporator (which is caused by the degree of superheat).

On the other hand, the low-pressure chamber 29 of the diaphragm chamber 26 communicates with the outlet side of the evaporator, and the inside of the low-pressure chamber 29 is at the same pressure as the pressure of the refrigerant gas leaving the evaporator. As a result, the diaphragm 25 is displaced by the pressure difference between the high pressure chamber 27 and the low pressure chamber 29.

Reference numeral 30 is an operating rod that transmits the movement of the diaphragm 25 to the valve body 21. The operating rod 30 passes through the inside of the receiving hole 31 formed toward the throttle hole 17, the upper end thereof contacts the lower surface of the diaphragm receiver 24 arranged in contact with the lower surface of the diaphragm 25, and the lower end thereof restricts the throttle. It is in contact with the upper surface of the valve body 21 through the hole 17. 33 is an O-ring for sealing.

Therefore, the valve body 21 is displaced according to the displacement of the diaphragm 25 via the actuating rod 30, thereby changing the opening area of the throttle hole 17 and controlling the amount of the refrigerant sent to the evaporator. To be done.

With the throttle hole 17 thus laid out as a center, the front half portion 13 a of the mouthpiece 13 and the operating rod 30 are surrounded so as to surround the throttle hole 17 on the refrigerant outlet 12 side, and a cylindrical shape is formed. A mesh filter (a porous member) 35 is provided near the aperture 17. However, a gap 36 is formed between the inner peripheral surface of the mesh filter 35 and the outer peripheral surface of the front half 13a of the mouthpiece 13, the upper end side is fixed to the valve body 14, and the lower end part is the refrigerant. It is formed in the communication passage 37 that opens to the flow path leading to the outlet 12.

Therefore, the liquid portion of the bubbles generated by the adiabatic expansion of the refrigerant through the throttle hole 17 passes through the mesh filter 35, and the gas portion passes through the communication passage 37 without passing through the mesh filter 35 having high resistance. pass. Therefore, the bubbles are then separated into the liquid portion and the gas portion and disappear, and the bubble noise is not generated.

Therefore, it is possible to eliminate the bubble sound in the immediate vicinity of the diaphragm portion which is the source of the bubble sound.

[0021]

[Effect of the device]

 According to the expansion valve of the present invention, since the porous material is arranged in the vicinity of the throttle portion which is a bubble generation source, the distance from the bubble generation portion to the bubble disappearance portion is significantly shortened. As a result, there is an excellent effect that the generation of bubble noise can be significantly suppressed and the expansion valve can be made extremely quiet.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an example.

[Explanation of symbols]

 11 Refrigerant Inlet 12 Refrigerant Outlet 17 Throttle Hole (Throttle Portion) 21 Valve Body 25 Diaphragm 35 Mesh Filter (Perforated Member) 37 Communication Passage

Claims (1)

[Scope of utility model registration request] 1. A throttle portion having a small flow passage area formed between a refrigerant inlet to which a high-pressure liquid refrigerant is supplied and a refrigerant outlet connected to an inlet of an evaporator, and a refrigerant gas leaving the evaporator. In an expansion valve provided with a diaphragm that is displaced by temperature fluctuations and a valve body that operates according to the displacement of the diaphragm to open and close the throttle section, close the throttle section on the refrigerant outlet side so as to surround the throttle section. An expansion valve, comprising: a cylindrical porous member disposed in the above, and a communication passage that communicates the throttle portion and the refrigerant outlet without passing through a hole formed in the porous member.