JP2001091110A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve in which a rod is not fixed to a valve element and the valve element can be easily incorporated in the valve at the time of assembling the valve. SOLUTION: In an expansion valve, a valve element 16 is urged from the direction opposition to a rod 20 by a compression spring 17, the spring 17 is formed in such a tapered state that the winding diameter becomes smaller as going toward the valve element 16, and the rod 20 is brought into contact with the element 16 without fixing the rod 20 to the element 16 by fixing the element 16 to the end section of the spring 17.

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 adiabatically expanding a refrigerant while controlling the flow rate of the refrigerant sent to an evaporator in a refrigeration cycle.

[0002]

2. Description of the Related Art There are various types of expansion valves, and a valve element is arranged so as to face a valve seat hole formed by narrowing the middle of a high-pressure refrigerant flow path through which a high-pressure refrigerant sent to an evaporator passes. ,
2. Description of the Related Art An expansion valve that opens and closes a valve body in accordance with the temperature and pressure of a low-pressure refrigerant sent from an evaporator is widely used.

[0003] In such an expansion valve, a rod is inserted between a power element that operates according to the temperature and pressure of the low-pressure refrigerant sent from the evaporator and a valve body so as to be movable back and forth in the axial direction. The valve element is urged by a compression coil spring from a direction opposite to the rod, and the power element causes the valve element to open and close via the rod.

[0004]

In many cases, the expansion valve having the above-mentioned structure has a valve body fixed to a rod by welding or the like. However, the expansion valve has a structure in which the rod is assembled from the side opposite to the valve body. In this case, the valve body is merely in contact with the end face of the rod.

Therefore, when assembling the valve body at the time of assembling, when the valve body is detached from a predetermined position and cannot be assembled well, the assembly work must be repeated and time is wasted. Was not few.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an expansion valve in which a rod and a valve element are not fixed, and in which the valve element can be easily incorporated at the time of assembly.

[0007]

In order to achieve the above object, an expansion valve according to the present invention is provided in a valve seat hole formed by narrowing the middle of a high-pressure refrigerant flow path through which a high-pressure refrigerant sent to an evaporator passes. A valve element is placed opposite to the valve element, and a rod arranged to be able to advance and retreat in the axial direction is sandwiched between the power element and the valve element that operate according to the temperature and pressure of the low-pressure refrigerant sent from the evaporator. And an expansion valve in which the valve body is urged by a compression coil spring from a direction opposite to the rod,
The compression coil spring is formed in a tapered shape with the winding diameter gradually reduced to the side close to the valve body, the valve body is fixed to the end of the compression coil spring, and the rod is brought into contact with the valve body without being fixed. It is a thing.

[0008] If the compression coil spring and the valve body are formed of the same material, the recycling process can be easily performed. The power element may be configured to apply a couple to the rod. In this case, the contact surface of the power element-side member that contacts the end of the rod is inclined with respect to the rod axis. It may be formed to be inclined.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an expansion valve according to an embodiment of the present invention. In the drawing, 1 is an evaporator, 2 is a compressor, 3 is a condenser, 4 is a liquid receiver connected to the outlet side of the condenser 3 and containing a high-pressure liquid refrigerant, and 10 is an expansion valve. These components form a refrigeration cycle, and are used, for example, for indoor cooling devices (car air conditioners) of automobiles.

The main body block 11 of the expansion valve 10 has a low-pressure refrigerant passage 12 through which low-temperature and low-pressure refrigerant gas sent from the evaporator 1 to the compressor 2 passes, and a high-temperature and high-pressure refrigerant liquid sent to the evaporator 1. And a high-pressure refrigerant channel 13 for adiabatic expansion through the passage.

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 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 parallel to each other, and a through-hole 14 formed in the main body block 11 perpendicularly to the low-pressure refrigerant flow path 12 and the high-pressure refrigerant flow path. It passes through between the road 13. A power element 30 is attached to an opening formed in the same direction as the through hole 14 so as to pass outward from the low-pressure refrigerant flow path 12.

In the middle of the high-pressure refrigerant flow passage 13, a valve seat hole 15 is formed at the center where the flow passage area is narrowed in the middle. The valve seat hole 15 is spherically opposed to the valve seat hole 15 from the upstream side. Is disposed. However, the valve element 16 only needs to have a spherical surface at least on the side facing the valve seat hole 15.

As a result, the narrowest part of the gap between the valve body 16 and the inlet of the valve seat hole 15 becomes the throttle of the high-pressure refrigerant flow path 13, and the downstream flow from the evaporator 1 to the narrowed part. In the passage, the high-pressure refrigerant adiabatically expands.

The valve body 16 is made of, for example, a metal such as stainless steel. The open end of the valve seat hole 15 facing the valve body 16 is formed in a tapered chamfered shape so as to spread outward. I have.

The valve element 16 is urged by a compression coil spring 17 in a direction approaching the valve seat hole 15 (ie, in a closing direction). The compression coil spring 17 formed in a tapered shape whose winding diameter gradually decreases toward the valve body 16 is made of the same metal as the valve body 16 such as stainless steel.

A valve body 16 is directly fixed to the smaller end of the compression coil spring 17 by welding or the like (adhesion, soldering or the like). By forming the compression coil spring 17 in a tapered shape, the valve body 16 can be directly fixed to the end thereof, and an appropriate spring constant can be obtained.

Since the valve body 16 is directly fixed to the compression coil spring 17, the valve body 16 does not fall off from the compression coil spring 17 at the time of assembly without adding extra cost. Are made of the same material, so that the recycling process is easy.

FIG. 1 schematically shows a state in which the valve body 16 is assembled at the time of assembly. The valve body 16, the compression coil spring 17 and the spring receiver 18 are assembled into the main body block 11 from the direction of arrow A, and the rod 20 is It is assembled from the opposite arrow B direction.

At this time, the valve body 16 is fixed and integrated with the compression coil spring 17 instead of alone, so that the valve body 16 does not unintentionally come off from a predetermined position and the assembly work is easy. In a short time.

Returning to FIG. 2, the compression coil spring 17
Is formed in the main body block 11 in the same direction as the valve seat hole 15 (therefore, in a direction perpendicular to the high-pressure refrigerant flow path 13), and extends outward.

In the hole 19, a spring receiver 18 for receiving the proximal end side of the compression coil spring 17 is press-fitted and fixed from the outside. Since there is no screw portion, there is no generation of cutting chips due to screwing.

The spring receiver 18 is formed in a cylindrical shape whose inner end face is closed. The fixing position is adjusted during assembly so that the spring force of the compression coil spring 17 becomes an appropriate value. It is assembled so that there is no gap between them.

In order to secure the airtightness of the mounting portion of the spring receiver 18 to the main body block 11 without using a sealing member such as an O-ring, for example, a screw lock or welding may be performed. Airtightness may be obtained by springback using a material having high spring properties for the spring receiver 18.

The rod 20 inserted into the through hole 14
It is slidably provided in the axial direction, the upper end reaches near the back surface of the power element 30, the middle part vertically intersects the low-pressure refrigerant flow path 12 and fits in the through hole 14, and the lower end has a valve. It passes through the seat hole 15 and contacts the head of the valve body 16. The rod 20 is formed to be thinner than the valve seat hole 15 so that a space between the rod 20 and the wall surface of the valve seat hole 15 serves as a coolant flow path.

A conical recess 22 having a V-shaped cross section is formed on the end face of the rod 20 that contacts the valve body 16. As a result, the valve element 16 is lightly fitted into the end face of the rod 20, so that the valve element 16 does not rattle in the lateral direction, and therefore the vibration caused by the valve element 16 vibrating in the lateral direction. There is no sound.

The power element 30 is surrounded by a housing 31 made of a highly rigid stainless steel plate.
The outer half of the airtight chamber 30 is hermetically surrounded by a housing 31 and a diaphragm 32 made of a flexible thin metal plate (for example, a stainless steel plate having a thickness of 0.1 mm).
a.

The refrigerant passages 12 and 13 are provided in the airtight chamber 30a.
A gas in a saturated vapor state having the same or similar properties as the refrigerant flowing therein is filled therein, and the gas filling inlet is closed by a stopper 34.

In the power element 30, all parts are formed of the same metal material such as stainless steel. Therefore, when the expansion valve 10 is broken, the power element 30 can be taken out and easily recycled.

A large dish-shaped diaphragm receiving board 33 is arranged facing the rear face of the diaphragm 32, and the end of the rod 20 is in contact with the rear face of the diaphragm receiving board 33. Therefore, the rod 20 is disposed so as to be sandwiched between the diaphragm receiving plate 33 and the valve body 16 so as to be able to advance and retreat in the axial direction.

As shown in the perspective view of FIG. 3, the diaphragm receiving board 33 has a dish shape in which three leg portions 33a are formed by bending, and is formed by pressing a plate material.

A slope 36 is formed at the center of the back surface of the diaphragm receiving plate 33, and the leg-like portion 33a has a function of loosely fitting the inner peripheral surface of the housing 31 to stabilize the posture of the diaphragm receiving plate 33. are doing. In addition, the leg 33
The portion cut out by bending a is the refrigerant passage 40.

The end surface of the rod 20 which comes into contact with the slope 36 formed on the diaphragm receiving board 33 is rounded into a smooth curved surface. However, the rod 2 contacting the slope 36
The end face shape of 0 can take a conical shape or other various shapes.

The through hole 14 formed in the main body block 11
An intermediate portion of the rod 20 is fitted to the portion, for example, the fitting length (L) is about 10 to 15 mm, and the fitting gap (e) is formed to about 0.01 to 0.12 mm. As a result, the backlash of the rod 20 is restricted, and the valve body 16
Vibration noise generation from the part is suppressed.

Opening 14a of through-hole 14 on low-pressure refrigerant flow path side
A projection 23 is provided on the rod 20 at a position slightly away from the rod 20. The projection 23 is formed by crushing the rod 20 from the side.

Since the projections 23 are formed as described above, the rod 20 does not enter the through hole 14 any more, so that the rod 20 can be held in a stable state during assembly. The low pressure refrigerant flow path side opening 14a of the through hole 14 is chamfered in a tapered shape.

The housing 31 formed so as to entirely surround the power element 30 has a screw portion 25 screwed to the main body block 11 formed on the outer surface. 26 is a seal member.

A rod receiver 37 into which the rod 20 is slidably fitted near the end is formed at the center of the portion of the housing 31 facing the low-pressure refrigerant flow path 12. The sticking is regulated and the generation of noise is suppressed.

The low pressure refrigerant flow path 12 around the rod receiver 37
A refrigerant passage hole 38 for guiding a small amount of refrigerant passing through the low-pressure refrigerant flow path 12 into the power element 30 is formed in the housing 31 at a portion facing the low-pressure refrigerant flow path 12, and passes through the low-pressure refrigerant flow path 12. The change in the state of the temperature and the pressure of the refrigerant is delayed and transmitted slowly to the back surface of the diaphragm 32, so that the expansion valve 10 does not suddenly change its operation.

In the expansion valve configured as described above,
When the temperature of the low-pressure refrigerant flowing in the low-pressure refrigerant flow path 12 decreases, the temperature of the diaphragm 32 decreases, and the saturated vapor gas in the hermetic chamber 30 a of the power element 30 condenses on the inner surface of the diaphragm 32.

Then, the pressure in the hermetic chamber 30a decreases and the diaphragm 32 is displaced, so that the rod 20 is pushed and moved by the compression coil spring 17, and as a result, the valve body 16 moves to the valve seat hole 15 side. As a result, the flow path area of the high-pressure refrigerant is reduced, and the flow rate of the refrigerant sent to the evaporator 1 is reduced.

When the temperature of the low-pressure refrigerant flowing in the low-pressure refrigerant passage 12 rises, the valve body 16 is moved in a direction away from the valve seat hole 15 by the rod 20 pushed by the power element 30 by the operation reverse to the above. As a result, the flow path area of the high-pressure refrigerant increases, and the flow rate of the high-pressure refrigerant sent to the evaporator 1 increases.

The contact surface of the diaphragm receiving plate 33 with which the rod 20 abuts is a slope 36, so that the power element 30 and the compression coil spring 1
The force applied to the rod 20 from the position 7 also acts as a couple that tries to rotate the rod 20 in a direction that changes the direction of the axis.

As a result, when the rod 20 advances and retreats, a considerably large frictional resistance is generated between the rod 20 and the inner wall of the through-hole 14. Since the operation of the rod 20 (that is, the opening / closing operation of the valve element 16) does not react sensitively thereto, the operation of the valve element 16 does not react sensitively to the pressure fluctuation of the high-pressure refrigerant even if there is a pressure fluctuation. stable.

The present invention is not limited to the above embodiment. For example, the spring receiver 18 may be screwed and attached to the main body block 11 as shown in FIG. Further, the valve body 16 is not necessarily limited to a spherical body, and may have a conical shape or another shape.

[0046]

According to the present invention, the compression coil spring is formed in a tapered shape in which the winding diameter is gradually narrowed toward the side close to the valve body, and the valve body is fixed to the end of the compression coil spring, whereby the rod is fixed. In an expansion valve in which the valve body and the valve body are not fixed, the valve body can be easily incorporated at the time of assembly, and can be realized at low cost.

Further, by using the same material for the compression coil spring and the valve body, it is possible to easily carry out the recycling process.

[Brief description of the drawings]

FIG. 1 is a partially exploded vertical sectional view showing a state where a valve body according to an embodiment of the present invention is incorporated.

FIG. 2 is a longitudinal sectional view of the expansion valve according to the embodiment of the present invention.

FIG. 3 is a perspective view of a diaphragm receiver of the expansion valve according to the embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of an expansion valve having a different spring receiver according to the embodiment of the present invention.

[Explanation of symbols]

 12 Low-pressure refrigerant flow path 13 High-pressure refrigerant flow path 15 Valve seat hole 16 Valve element 17 Compression coil spring 18 Spring receiver 20 Rod 30 Power element

Claims (4)

[Claims] 1. A rod having a valve body disposed so as to face a valve seat hole formed by narrowing the middle of a high-pressure refrigerant flow path through which a high-pressure refrigerant sent to an evaporator passes, and a rod disposed so as to be able to advance and retreat in an axial direction. Is interposed between the power element that operates according to the temperature and pressure of the low-pressure refrigerant sent from the evaporator and the valve body, and the valve body is compressed by a compression coil spring from a direction opposite to the rod. The compression coil spring is formed in a tapered shape in which a winding diameter is gradually reduced toward a side closer to the valve body, and the valve body is fixed to an end of the compression coil spring. An expansion valve, wherein the rod is brought into contact with the body without being fixed. 2. The expansion valve according to claim 1, wherein said compression coil spring and said valve body are made of the same material. 3. The power element is configured to apply a couple to the rod from the power element.
An expansion valve as described. 4. The expansion valve according to claim 3, wherein an abutting surface of the power element-side member abutting on an end of the rod is formed obliquely to an axis of the rod.