JPH08145505A - Expansion valve - Google Patents

Abstract

PURPOSE: To obtain an expansion valve which checks surely the vibration in the axial direction of a valve for changing the passage area of a high-pressure refrigerant passage and thereby enables elimination of noise. CONSTITUTION: In an expansion valve wherein a rod 28 is driven in the axial direction by a temperature-sensitive displacement mechanism 30 sensing the temperature of a low-pressure refrigerant sent out from an evaporator 1 and making displacement and valve mechanisms 24 and 25 for changing the passage area of a high-pressure refrigerant passage 13 leading to a refrigerant inlet of the evaporator 1 are driven by the motion in the axial direction of the rod 28, an actuating means 29 for actuating the rod 28 in a direction perpendicular to the axial direction is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve for automatically controlling the amount of refrigerant used in a refrigerating cycle of a vehicle air conditioner and sent to an evaporator.

[0002]

2. Description of the Related Art In general, an expansion valve of this type drives a rod axially by a temperature-sensing displacement mechanism that senses and displaces the temperature of a low-pressure refrigerant sent from an evaporator, and communicates with a refrigerant inlet of the evaporator. The valve mechanism for changing the flow passage area of the high pressure refrigerant flow passage is driven by the axial movement of the rod.

The valve for changing the flow passage area of the high pressure refrigerant flow passage is pushed by the rod from one side and pushed by the spring from the opposite direction, and is attached from both directions except when it is fully closed. It stands still at a position where powers are balanced.

[0004]

However, if the valve is slightly displaced in the closing direction, the differential pressure between the upstream side and the downstream side of the valve increases instantaneously, so that the valve moves closer to the closing position than the rest position. The phenomenon of going too far occurs.

At the next moment, on the contrary, the valve goes too far in the opening direction, and such minute vibration in the axial direction of the valve is continuously repeated with an amplitude of, for example, about 0.2 mm, and as a result, A comparatively loud noise of “boo” was generated from the expansion valve and became one of the noise sources in the interior of the automobile.

On the other hand, the rod pushing the valve is provided with an O-ring for sealing the refrigerant along the outer peripheral surface of the rod so as to prevent the refrigerant from leaking, and the vibration of the rod and the valve is suppressed to some extent. There is.

However, when the rod vibrates about 0.2 mm in the axial direction, the O-ring flexes and elastically deforms following the movement of the rod, so that frictional resistance is present on the contact surface between the O-ring and the rod. Does not occur. Therefore, the axial vibration of the rod cannot be prevented, and the generation of the noise as described above due to the minute vibration of the valve cannot be eliminated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an expansion valve which can surely prevent axial vibration of the valve for changing the flow passage area of the high pressure refrigerant flow passage and eliminate the generation of noise. .

[0009]

To achieve the above object, the expansion valve of the present invention axially drives a rod by a temperature sensitive displacement mechanism that senses and displaces the temperature of low-pressure refrigerant sent from an evaporator. Then, in the expansion valve configured to drive the valve mechanism for changing the flow passage area of the high-pressure refrigerant flow passage leading to the refrigerant inlet of the evaporator by the axial movement of the rod, the rod with respect to the axial direction. And an urging means for urging in a vertical direction.

The rod may be pressed by the biasing means against the inner peripheral surface of a bearing hole formed in the frame of the expansion valve so as to slidably support the rod in the axial direction.

[0011]

By urging the rod in the direction perpendicular to the axial direction by the urging means, frictional resistance against the axial movement of the rod is generated and the flow passage area of the high pressure refrigerant flow passage is changed. The slight vibration of the valve is blocked.

[0012]

Embodiments will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. In the figure, 1 is an evaporator,
2 is a compressor, 3 is a condenser, 4 is a receiver that is connected to the outlet side of the condenser 3 and stores a high-pressure liquid refrigerant, 10 is an expansion valve, and these form a refrigeration cycle. For example, it is used for an indoor air conditioner of an automobile.

The main body frame 11 of the expansion valve 10 has a low-pressure refrigerant passage 12 for passing a low-temperature low-pressure refrigerant sent from the evaporator 1 to the compressor 2 and a high-temperature high-pressure refrigerant sent to the evaporator 1 for heat insulation. A high-pressure refrigerant channel 13 for expanding is formed.

The low-pressure refrigerant passage 12 has an inlet end connected to the outlet of the evaporator 1 and an outlet connected to the inlet of the compressor 2. The high-pressure refrigerant flow path 13 has an inlet-side end connected to the outlet of the liquid receiver 4 and an outlet-side connected to the inlet of the evaporator 1.

The low-pressure refrigerant flow path 12 and the high-pressure refrigerant flow path 13 are formed in parallel with each other, and a through hole 14 perpendicular to this is formed.
Penetrates between the low-pressure refrigerant channel 12 and the high-pressure refrigerant channel 13. In addition, a greenhouse 30 is attached to the opening formed in the same direction as the through hole 14 so as to escape to the outside from the low-pressure refrigerant channel 12.

A valve mechanism 20 is provided in the high pressure refrigerant flow path 13, and a valve seat 23 is formed in the center of the high pressure refrigerant flow path 13. Then, when the ball valve 25 biased from the lower side (high pressure side) toward the valve seat 23 by the compression coil spring 24 closes the valve seat 23, the high pressure refrigerant flow path 13 is closed.

A ball valve support 26 supports the ball valve 25. Reference numeral 27 is an adjustment nut screwed with the expansion valve body frame 11 to adjust the biasing force of the coil spring 24. Reference numeral 21 is an O-ring for sealing.

The rod 28 inserted in the through hole 14 is provided so as to be slidable in the axial direction, and the upper end of the rod 28 is located in the greenhouse 3.
0, the middle portion passes through the low pressure refrigerant flow path 12 vertically, passes through the through hole 14, and the lower end is in contact with the upper end of the ball valve 25.

Therefore, if the ball valve 25 is pushed by the rod 28 and moved downward against the biasing force of the compression coil spring 24 below, the flow passage area of the high pressure refrigerant flow passage 13 increases. As described above, the flow passage area of the high pressure refrigerant flow passage 13 changes in accordance with the movement amount of the rod 28, and thus the amount of the high pressure refrigerant supplied to the evaporator 1 changes.

In the high pressure refrigerant flow path 13, a biasing spring 29 formed of a small compression coil spring is provided in the expansion valve body frame 11 so as to bias the rod 28 laterally, that is, in the direction perpendicular to the axial direction. It is interposed between the rod 28 and the rod 28.

Due to the urging force of the urging spring 29, the rod 28 is constantly pressed against the inner peripheral wall 15 of the through hole 14 formed in the expansion valve main body frame 11. Therefore, when the rod 28 moves in the axial direction, the inner peripheral wall 1
A frictional resistance always acts between 5 and 5.

The greenhouse 30 includes a housing 31 made of a thick metal plate and a flexible thin metal plate (for example, a thickness of 0.1 mm).
It is airtightly surrounded by a diaphragm 32 made of a stainless steel plate).

The diaphragm receiving plate 3 is formed in a large dish shape so as to face the central portion of the lower surface of the diaphragm 32.
3 is arranged, and the top portion of the rod 28 is in contact with the central portion of the lower surface thereof.

In the greenhouse 30, the coolant flow passages 12,
A saturated vapor state gas having the same or similar properties as the refrigerant flowing in 13 is filled, and the gas filling injection hole is closed by a plug 34. 36 is an O-ring for sealing.

A bush 38 made of a plastic material having a low thermal conductivity is fixed to a stationary portion between the low pressure refrigerant flow path 12 and the greenhouse 30. Therefore, if the bush 38 does not exist, a large amount of the refrigerant flowing through the low-pressure refrigerant flow path 12 wraps around the greenhouse 30 side and comes into direct contact with the greenhouse 30. The wraparound is regulated.

However, in the bush 38, in addition to the through hole 39 through which the rod 28 is inserted, the low-pressure refrigerant flow path 12 and the greenhouse 3 are provided.
A plurality of ventilation grooves 40 for communicating with the 0 side are formed so as to penetrate therethrough. Therefore, the low-pressure refrigerant flowing in the low-pressure refrigerant flow path 12 passes through the ventilation holes 40 and flows around to the greenhouse 30 side by a small amount.

As a result, the temperature of the refrigerant flowing in the low-pressure refrigerant flow path 12 is slowly transmitted to the greenhouse 30 by a small amount of the refrigerant flowing around the greenhouse 30 side through the ventilation groove 40.

In the expansion valve thus constructed,
When the temperature of the refrigerant flowing in the low-pressure refrigerant channel 12 decreases, the temperature of the diaphragm 32 decreases, and the saturated vapor gas in the greenhouse 30 condenses on the inner surface of the diaphragm 32.

Then, since the pressure inside the greenhouse 30 is lowered and the diaphragm 32 is displaced, the rod 28 is pushed and moved by the compression coil spring 24, and as a result, the ball valve 25 approaches the valve seat 23 and the refrigerant. Since the area of the flow path is reduced, the flow rate of the refrigerant flowing into the evaporator 1 is reduced.

When the temperature of the refrigerant flowing in the low-pressure refrigerant flow path 12 rises, the ball valve 25 is pushed by the rod 28 and separated from the valve seat 23 by the operation opposite to the above, and the flow path area of the refrigerant increases, so that evaporation The flow rate of the refrigerant flowing into the container 1 increases.

The rod 28, which moves back and forth in the axial direction during such an operation, is provided with a biasing spring 29 between the rod 28 and the inner peripheral wall 15 of the through hole 14 formed in the expansion valve main body frame 11 which is a stationary member. The frictional resistance due to the biasing force is always acting.

As a result, the ball valve 25 is prevented from moving too far from its original position to vibrate and vibrate, so that the noise caused by the vibration of the ball valve 25 can be almost completely eliminated.

FIG. 2 shows a second embodiment of the present invention, in which a portion of the through hole 14 through which the rod 28 is inserted, which is close to the low pressure refrigerant flow passage 12, is formed in a large counterbore shape, and the inner portion thereof is formed. In this portion, an O-ring 16 for sealing and a pressing ring 17 that are in close contact with the outer peripheral surface of the rod 28 are arranged, and the rod 2
A biasing spring 29 for biasing 8 laterally is arranged at that portion.

Therefore, in this embodiment, the refrigerant is prevented from leaking from the high pressure refrigerant passage 13 to the low pressure refrigerant passage 12 through the space between the outer peripheral surface of the rod 28 and the inner peripheral surface of the through hole 14.
The O-ring 16 seals.

Then, as in the first embodiment, the rod 2
For 8, the frictional resistance due to the urging force of the urging spring 29 always acts between the inner peripheral wall 15 of the through hole 14 and the vibration of the ball valve 25 is blocked, so that no noise is generated.

FIG. 3 shows a third embodiment of the present invention, in which the urging spring 29 is arranged at the bush 38 portion. On the rod 28, the biasing spring 2 is provided between the rod 28 and the inner peripheral wall 39a of the through hole 39 formed in the bush 38 which is a stationary member.
Since the frictional resistance due to the biasing force of 9 always acts and the vibration of the ball valve 25 is blocked, noise is not generated.

The device of the third embodiment is similar to the second embodiment in that the O-ring 16 and the press ring 17 are provided, but the O-ring 16 and the press ring 17 are pressed so as not to come out to the low pressure refrigerant flow passage 12 side. A disc-spring-shaped fixing ring 18 for pressing and fixing the ring 17 is attached.

FIG. 4 shows a fourth embodiment of the present invention, in which a biasing spring for biasing the rod 28 laterally is applied to a Belleville spring-shaped fixing ring that holds the O-ring 16 and the holding ring 17. 29 is integrally formed. However, a small compression coil spring 117 is interposed between the pressing ring 17 and the biasing spring 29 to prevent the pressing ring 17 from rattling.

The biasing spring 29, as shown in FIG.
A dogleg-shaped urging spring portion 29a for urging the rod 28 is formed in a shape extending from the disc spring portion 29b.

As a result, a frictional resistance due to the urging force of the urging spring 29 always acts on the rod 28 between the rod 28 and the inner peripheral wall 15 of the through hole 14 formed in the expansion valve main body frame 11 which is a stationary member. As a result, the vibration of the ball valve 25 is blocked, so that no noise is generated.

FIG. 7 shows a fifth embodiment of the present invention, which is shown in FIG. 6 between a disc-spring-shaped fixing ring 18 for holding the O-ring 16 and the pressing ring 17 and the pressing ring 17. An urging spring 29 formed of a wire material for a flexible spring is arranged to urge the rod 28 laterally.

A biasing spring 29 is provided between the rod 28 and the inner peripheral wall 15 of the through hole 14 of the expansion valve body frame 11.
As in the other embodiments, the frictional resistance due to the urging force of the ball valve 25 is always acting, and the vibration of the ball valve 25 is blocked so that noise is not generated.

[0043]

According to the present invention, since the rod is urged in the direction perpendicular to the axial direction by the urging means, frictional resistance is generated against the axial movement of the rod, and the high-pressure refrigerant flow. Since the minute vibration of the valve for changing the flow passage area of the passage is prevented, it is possible to reliably eliminate the generation of noise due to the minute vibration of the valve.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an expansion valve according to a first embodiment.

FIG. 2 is a vertical sectional view of an expansion valve according to a second embodiment.

FIG. 3 is a vertical sectional view of an expansion valve according to a third embodiment.

FIG. 4 is a vertical sectional view of an expansion valve according to a fourth embodiment.

FIG. 5 is a perspective view of a biasing spring according to a fourth embodiment.

FIG. 6 is a plan view of a biasing spring according to a fifth embodiment.

FIG. 7 is a vertical sectional view of an expansion valve according to a fifth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 evaporator 10 expansion valve 13 high-pressure refrigerant flow path 15 inner peripheral wall 23 valve seat 24 compression coil spring 25 ball valve 28 rod 29 biasing spring 30 greenhouse

Claims (2)

[Claims] 1. A rod is axially driven by a temperature-sensing displacement mechanism that senses and displaces the temperature of a low-pressure refrigerant sent from an evaporator, so that the flow passage area of a high-pressure refrigerant passage leading to a refrigerant inlet of the evaporator is reduced. An expansion valve in which a valve mechanism for changing is driven by an axial movement of the rod is characterized in that urging means for urging the rod in a direction perpendicular to the axial direction is provided. Expansion valve to. 2. The rod is pressed by the biasing means against the inner peripheral surface of a bearing hole formed in the frame of the expansion valve so as to slidably support the rod in the axial direction. Expansion valve.