JP2014001895A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce refrigerant passing noise at start of an expansion valve and easily obtain an intended flow rate.SOLUTION: A valve body 10 of an expansion valve 1 includes: an inlet port 14 for introducing a high-pressure refrigerant to a valve chamber 20; an orifice 50; a refrigerant outlet passage 52 leading toward an evaporator; and a return passage 60 returning from the evaporator to a compressor. A power element 70 operates a valve member 30 via an operation rod 82 in response to pressure and temperature of a refrigerant in the return passage 60. A support member 100 is disposed in a valve chamber 20 to cover a coil spring 42 and support the valve member 30. When the valve is closed, a shoulder portion 130 of the support member 100 overlaps with the inlet port 14 to narrow an opening area.

Description

  The present invention relates to an expansion valve provided in a refrigeration cycle such as an air conditioner.

This type of expansion valve is sometimes installed in a partition wall that partitions an engine compartment and a vehicle compartment in a car air conditioner, for example, and noise reduction during operation of the air conditioner is required.
Patent Document 1 below discloses an expansion valve having a throttle portion at an inlet port for introducing high-pressure refrigerant condensed by a condenser into a valve chamber in order to reduce such noise.
By comprising in this way, the bubble in the refrigerant | coolant which passes an inlet port is subdivided, and the noise at the time of refrigerant | coolant passage reduces.

Japanese Patent Laid-Open No. 11-287536

However, the expansion valve of Patent Document 1 is configured to constantly throttle the high-pressure refrigerant regardless of the valve opening, and thus has a problem that it is difficult to ensure a desired flow rate.
An object of the present invention is to provide an expansion valve that reduces noise during passage of the refrigerant and makes it easy to obtain a desired refrigerant flow rate by narrowing down the high-pressure refrigerant condensed by the condenser.

  In order to achieve the above object, an expansion valve of the present invention includes an inlet port for introducing a high-pressure refrigerant condensed by a condenser, a valve chamber communicating with the inlet port, an orifice for decompressing the refrigerant introduced into the valve chamber, A valve body having an outlet passage for leading the refrigerant that has passed through the orifice to the evaporator side and a return passage through which the refrigerant returning from the evaporator to the compressor passes; a valve member that opens and closes the orifice; and the valve disposed in the valve chamber An expansion valve comprising: a support member that supports a member; and a valve member driving device that drives the valve member, wherein the support member closes the orifice and the outlet port of the inlet port. The cooling passage introduced into the valve chamber with the opening area of the refrigerant passage formed by the gap with the support member smaller than the opening area of the outlet of the inlet port. With squeeze, the valve member is what the opening area of the refrigerant passage as it moves in the opening direction is configured to increase.

The support member can be, for example, a stepped cylindrical member formed by pressing a metal plate.
The support member may cover a coil spring that biases the support member in the valve closing direction. In this case, it is possible to reduce noise by preventing the refrigerant introduced into the valve chamber from directly touching the coil spring.
Further, a refrigerant rectification passage may be formed between the outer surface of the support member and the inner surface of the valve chamber. In this case, it is possible to prevent generation of noise by preventing generation of turbulent flow of the refrigerant and subdividing bubbles contained in the refrigerant.

  The expansion valve of the present invention reduces the amount of high-pressure refrigerant throttling by the support member as the valve member moves in the opening direction, so that noise during passage of the refrigerant at start-up can be reduced and a desired refrigerant flow rate can be easily obtained. There is an advantage.

The longitudinal cross-sectional view of the front side of the Example of this invention (at the time of valve closing). The longitudinal cross-sectional view by the side of the Example of this invention (at the time of valve closing). The longitudinal cross-sectional view of the front side of the Example of this invention (at the time of valve opening). It is a cross-sectional view of the Example of this invention, (a) is the sectional view on the AA 'line of FIG. 1, (b) is the BB' sectional view of FIG. 2, (c) is C of FIG. -C 'sectional view taken on the line. The perspective view of a supporting member. Explanatory drawing of an effect | action of the Example of this invention.

1 and 2 are longitudinal sectional views showing an embodiment of the expansion valve of the present invention.
The expansion valve 1 has a valve body 10, and a valve chamber 20 formed in the lower part of the valve body 10 is provided with an inlet passage 12 into which high-pressure refrigerant from the receiver side is introduced. The inlet passage 12 has a small-diameter inlet port 14. And communicates with the valve chamber 20 through the inlet port 14.

An orifice 50 for reducing the pressure of the refrigerant introduced into the valve chamber 20 is provided in the upper portion of the valve chamber 20. A valve seat 32 is formed at the lower end of the orifice 50, and the valve member 30 is disposed opposite to the valve seat 32.
The valve member 30 is supported by a support member 100 described later, and a coil spring 42 that biases the support member 100 upward is provided between the support member 100 and the plug 44 screwed into the opening of the valve chamber 20. It is done. A seal ring 46 is fitted on the valve chamber 20 side of the plug 44 to achieve sealing of the valve chamber 20.
The refrigerant that has passed through the orifice 50 flows out into the outlet passage 52 having a large inner diameter, and is sent out to an evaporator (not shown).
The inlet passage 12 and the outlet passage 52 are formed so that their axes are orthogonal to each other, and the high-pressure refrigerant flowing into the valve body 10 from the condenser via the inlet passage 12 is formed in an L shape in the valve body 10. To the evaporator via the outlet passage 52.

The refrigerant having exchanged heat with the outside air by the evaporator is sent to an L-shaped return passage 60 (see FIG. 4C) provided in the upper part of the valve body 10 and returned to the compressor side.
The refrigerant in the return passage 60 is also sent to the power element 70 side through the opening 62.

The power element 70 has a structure in which a diaphragm 74 is sandwiched between an upper lid 72 and a lower lid 73, and an upper pressure chamber 76 and a lower pressure chamber 78 are formed above and below the diaphragm 74. The upper pressure chamber 76 is filled with working gas that expands and contracts according to the temperature of the refrigerant passing through the return passage 60.
The lower surface of the diaphragm 74 is supported by a receiving member 80, and the receiving member 80 is connected to an operating rod 82 that drives the valve member 30. The displacement of the diaphragm 74 is transmitted to the valve member 30 through the operating rod 82, and thereby the valve opening between the valve member 30 and the valve seat 32 is controlled.
The actuating rod 82 is elastically supported by a ring-shaped vibration-proof spring member 200 mounted in a recess 10 a formed in the valve body 10. The anti-vibration spring member 200 is externally fitted to the operating rod 82, and is configured to suppress radial movement while allowing axial movement with respect to the operating rod 82. Prevent occurrence.
The power element 70 is covered with a cover 90 so that the influence of the outside air temperature does not reach the working gas of the power element 70.

In the expansion valve 1 of the present invention, the support member 100 disposed in the valve chamber 20 also serves as a throttle member for high-pressure refrigerant introduced into the valve chamber 20.
The support member 100 is a stepped cylindrical member formed by pressing a metal plate, for example. In this case, it is possible to reduce the number of parts, thereby reducing weight and cost.

FIG. 5 is a perspective view showing details of the support member 100.
The support member 100 is a stepped cylindrical member in which a large-diameter portion 110 and a small-diameter portion 120 are connected by a shoulder 130, and a concave-shaped valve that supports the valve member 30 is provided on a top portion 122 of the small-diameter portion 120. A support portion 140 is formed.

1 and 2 show a valve closing state in which the valve member 30 completely closes the orifice 50.
The large-diameter portion 110 of the support member 100 is guided to the inner peripheral surface of the valve chamber 20, and the small-diameter portion 120 forms an annular space for guiding the high-pressure refrigerant to the orifice 50 between the inner peripheral surface of the valve chamber 20. This space rectifies the refrigerant to prevent the occurrence of turbulent flow, and acts to reduce noise by subdividing the bubbles in the refrigerant.
In the state of FIGS. 1 and 2, the shoulder 130 of the support member 100 is positioned above the lowermost portion of the inlet port 14 as shown in FIG. That is, the upper area of the large diameter portion 110 overlaps the outlet of the inlet port 14, and the opening area of the refrigerant passage formed by the gap between the upper portion of the large diameter section 110 and the outlet of the inlet port 14 is the opening area of the outlet of the inlet port 14. Therefore, the refrigerant flowing into the valve chamber 20 is throttled. By this action, the refrigerant passing sound at the time of starting the air conditioner is reduced.

FIG. 3 shows a valve opening state in which the operating rod 82 driven by the power element 70 pushes down the valve member 30 and the valve member 30 is separated from the valve seat 32.
In this state, the shoulder 130 of the support member 100 is located at the same position as the lowermost portion of the inlet port 14 from the middle of the inlet port 14 so as to have an opening area that secures a necessary refrigerant flow rate (FIG. 6C It is positioned at any position up to the position shown in ()). That is, the opening area of the refrigerant passage formed by the gap between the upper portion of the large diameter portion 110 and the outlet of the inlet port 14 increases as the shoulder portion 130 of the support member 100 moves in the opening direction. A refrigerant flow rate can be obtained. As described above, at the time of starting (when the valve is closed), the opening area of the refrigerant passage formed by the gap between the shoulder 130 and the outlet of the inlet port 14 is reduced to reduce the refrigerant introduced into the valve chamber 20. As the valve member 30 moves in the opening direction, the opening area of the refrigerant passage increases as shown in (a) → (b) → (c) of FIG. It is easy to obtain a refrigerant flow rate.

  In addition, since the expansion valve 1 of the present invention has a configuration in which the coil spring 42 disposed in the valve chamber 20 is covered with the support member 100, the high-pressure refrigerant flowing into the valve chamber 20 from the inlet port 14 is The coil spring 42 is not touched directly, and noise is reduced.

The present invention is not limited to the above embodiment, and various modifications can be made to the above embodiment.
For example, in the above-described embodiment, the example in which the member that closes the outlet of the inlet port 14 is integrally formed with the support member has been described.
In addition, various modifications can be made to the above embodiment without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Expansion valve 10 Valve body 12 Inlet passage 14 Inlet port 20 Valve chamber 30 Valve member 32 Valve seat 42 Coil spring 44 Plug 46 Seal ring 50 Orifice 52 Outlet passage 60 Return passage 62 Opening portion 70 Power element 72 Upper lid 73 Lower lid 74 Diaphragm 76 Upper pressure chamber 78 Lower pressure chamber 80 Receiving member 82 Actuating rod 90 Cover 100 Support member 110 Large diameter portion 120 Small diameter portion 122 Top portion 130 Shoulder portion 140 Valve support portion

Claims (4)

An inlet port for introducing high-pressure refrigerant condensed by a condenser, a valve chamber communicating with the inlet port, an orifice for depressurizing the refrigerant introduced into the valve chamber, an outlet passage for leading the refrigerant that has passed through the orifice to the evaporator side, and an evaporator A valve body having a return passage through which refrigerant returning from the compressor to the compressor passes, a valve member for opening and closing the orifice, a support member disposed in the valve chamber and supporting the valve member, and a valve for driving the valve member An expansion valve comprising a member driving device,
The support member has an opening area of the refrigerant passage formed by a gap between the outlet of the inlet port and the support member smaller than the opening area of the outlet of the inlet port in a state where the valve member closes the orifice. An expansion valve configured to throttle the refrigerant introduced into the valve chamber and increase the opening area of the refrigerant passage as the valve member moves in the opening direction.   The expansion valve according to claim 1, wherein the support member is a stepped cylindrical member formed by pressing a metal plate.   The expansion valve according to claim 1, wherein the support member is formed so as to cover a coil spring that urges the support member in a valve closing direction.   The expansion valve according to any one of claims 1 to 3, wherein a refrigerant rectifying passage is formed between an outer surface of the support member and an inner surface of the valve chamber.

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