JP2012197989A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve whose productivity is improved by eliminating a hole for filling a working gas and a plug for sealing the working gas in a power element of the expansion valve.SOLUTION: A valve body 10 is formed by extrusion of an aluminum alloy, and its top is equipped with the power element 100. The power element 100 has a diaphragm 130 which is fixed by being held between an upper cover member 110 and a ring-like receiving member 120. The upper cover member 110, the receiving member 120 and the diaphragm 130, are connected by projection welding in the atmosphere of the working gas to be enclosed in a pressure-actuated chamber 112. The assembled power element 100 is inserted in a cylindrical part 12 formed on an upper part of the valve body 10, and fixed by a caulked part 12a formed by caulking.

Description

  The present invention relates to an expansion valve with a built-in temperature sensing mechanism used in a refrigeration cycle.

In a refrigeration cycle used for an air conditioner or the like mounted on an automobile, a temperature expansion valve with a built-in temperature sensing mechanism that adjusts the passage amount of the refrigerant according to the temperature and pressure of the refrigerant is used.
Patent Document 1 shows an example of this type of expansion valve according to the present applicant.
The valve body of the expansion valve has an inlet port into which high-pressure refrigerant is introduced and a valve chamber communicating with the inlet port. A spherical valve member disposed in the valve chamber is opposed to the valve seat at the inlet of the valve hole that opens into the valve chamber, and is moved by a valve rod driven by a power element, so that a throttle passage between the valve seat and the valve seat To control the opening degree.
The refrigerant passing through the throttle passage is sent from the outlet port to the evaporator side. The refrigerant returning from the evaporator to the compressor side passes through a return passage provided in the valve body.
A valve member drive mechanism called a power element is provided on the top of the valve body.
The power element includes an upper lid member that forms a pressure working chamber in which working gas is sealed, a thin diaphragm that is elastically deformed by the pressure of the working gas, and a receiving member. The peripheral portions are formed by joining with TIG welding means or the like.
A working gas is enclosed in a pressure working chamber formed by the upper lid member and the diaphragm. In order to enclose the working gas in the pressure working chamber, a hole is provided in the top of the upper lid member, and after the working gas is injected from this hole, the hole is closed with a plug such as a steel ball, and the pressure working chamber is formed by projection welding means or the like. Seal.

JP 2008-180475 A

The above-described conventional expansion valve has a problem in that it takes a lot of time to manufacture since a hole is provided in the upper lid for sealing the working gas in the pressure working chamber of the power element and this hole is sealed with a sealing member. It was.
An object of the present invention is to provide an expansion valve in which a hole and a sealing means of an upper lid member provided for enclosing a working gas in a pressure working chamber of a power element can be omitted.

  In order to achieve the above object, an expansion valve according to the present invention includes an inlet port for introducing a high-pressure liquid refrigerant, a valve chamber communicating with the inlet port, a valve hole provided in the valve chamber, and the valve hole. A valve main body having an outlet port for leading the refrigerant expanded in the direction toward the outside, a valve member that contacts and separates a valve seat provided at the inlet of the valve hole, and moves the valve member An expansion valve comprising: a valve stem to be operated; and a power element enclosing a working gas that drives the valve stem, wherein the power element includes an upper lid member that forms a pressure working chamber in which the working gas is enclosed; A receiving member and a diaphragm sandwiched between the upper lid member and the receiving member are provided, and the upper lid member, the diaphragm and the receiving member are joined by projection welding in an atmosphere filled with the working gas. .

  According to the expansion valve of the present invention, the step of providing a hole for enclosing the working gas in the power element and the step of sealing the hole become unnecessary, so that productivity is improved and manufacturing cost is reduced. be able to.

Sectional drawing and the right view of the expansion valve of this invention. Explanatory drawing which shows the manufacturing process of the power element of the expansion valve of this invention. Explanatory drawing which shows the other Example of the power element of the expansion valve of this invention.

FIG. 1 shows a sectional view (a) and a right side view (b) of an expansion valve of the present invention.
The valve body 10 of the expansion valve of the present invention is produced by machining a material formed by extruding an aluminum alloy, and has an inlet port 20 into which a high-pressure refrigerant is introduced.
A small-diameter hole 22 is provided in the back wall of the inlet port 20 and communicates with a valve chamber 24 having a central axis in the longitudinal direction of the valve body 10. The valve chamber 24 communicates with the refrigerant outlet port 28 through a valve hole 26 formed coaxially.

A valve seat 25 is formed between the valve chamber 24 and the valve hole 26, and a spherical valve member 40 disposed in the valve chamber 24 faces the valve seat 25.
The valve member 40 is supported by a support member 42, and the support member 42 is supported by a plug 50 that seals the opening of the valve chamber 24 via a coil spring 44. The plug 50 is screwed into the opening of the valve chamber 24 by a screw portion 52. Since the plug 50 can be rotated by inserting a wrench into the bottomed hexagonal hole 53, the spring force of the coil spring 44 that supports the valve member body 40 can be adjusted by adjusting the screwing amount of the plug 50.
A seal member 54 is provided on the outer periphery of the plug 50 to seal the valve chamber 24.

The refrigerant sent out from the outlet port 28 is sent to the evaporator to exchange heat with the outside air. The refrigerant returning from the evaporator to the compressor side passes through a return passage 30 provided in the valve body 10.
The power element 100 is attached to the top of the valve body 10 by a crimping portion 12 a formed by caulking the upper portion of the cylindrical portion 12 formed on the upper portion of the valve body 10.
A seal member 64 is disposed between the power element 100 and the valve body 10.

The power element 100 is manufactured in a manner described later, and includes an upper lid member 110, a ring-shaped receiving member 120, and a diaphragm 130 sandwiched between the upper lid member 110 and the receiving member 120.
A working gas is sealed in the pressure working chamber 112 formed by the upper lid member 110 and the diaphragm 130. A stopper member 62 is disposed on the lower surface of the diaphragm 130, and the movement of the stopper member 62 is transmitted to the valve member 40 via the valve rod 60. A spring member 66 is disposed on the outer periphery of the valve stem 60 to add sliding resistance to the valve stem 60 to prevent vibration of the valve member 40.
The valve body 10 is provided with two through holes 70 penetrating the valve body 10 and used as bolt insertion holes for attaching the valve body 10 to other members. In addition, one bottomed screw hole 80 is also formed in the center of the valve body 10.

FIG. 2 is an explanatory view showing the structure of the power element 100 equipped in the expansion valve of the present invention.
The upper lid member 110 has a central portion that is convex upward, and is provided with a pressure working chamber 112. The receiving member 120 is a ring-shaped member and has an opening 122 at the center. The diaphragm 130 is a thin plate member having high hardness and elasticity. These three members are made of steel, for example.

As a means for enclosing the working gas in the pressure working chamber 112, three members are put in a chamber filled with the working gas, and the three members are joined in the chamber, and the working gas is put in the pressure working chamber 112. Encapsulate.
In the present invention, projection welding means is used as a joining means for the upper lid member 110, the receiving member 120, and the diaphragm 130.

In the embodiment of FIG. 2, a ring-shaped projection 124 that functions as a projection for welding is formed on the upper surface of the receiving member 120.
When the upper lid member 110, the diaphragm 130, and the receiving member 120 are overlapped in the chamber and are sandwiched between the electrodes 200 and 210 and energized, the protrusion 124 is melted and the three members are projection welded.

Since the power element 100 is manufactured as described above, the operation of injecting the working gas into the pressure working chamber 112 can be omitted, and a plug for closing the sealing port is not necessary.
Condensation tends to adhere to the outer peripheral portion of the plug body, and it causes corrosion, so post-treatment such as painting is necessary. However, in the present invention, this post-treatment can also be made unnecessary.

As shown in FIG. 1, the expansion valve according to the present invention has a power element 100 having the above-described configuration inserted inside a cylindrical portion 12 for mounting formed on the upper portion of the valve body 10, and is placed above the cylindrical portion 12. Caulking is performed to form a caulking portion 12 a, and the power element 100 is securely fixed to the valve body 10.
Since the power element 100 is pressed by the caulking portion 12a in a state where the sealing member 64 having elasticity is crushed, the power element 100 and the valve body 10 are reliably sealed.
Further, by sandwiching the projection welded portion of the power element 100 between the crimping portion 12a and the valve body 10, the projection welded portion is reinforced, and even if the internal pressure of the power element 100 is increased, the welded portion is not easily damaged.

Further, in this embodiment, the valve stem 60 is in contact with the diaphragm 130 via the stopper member 62, the receiving member 120 is ring-shaped, and there is a gap between the inner peripheral portion and the outer peripheral portion of the stopper member 130. The stopper member 130 is in contact with the valve body 10 so that the movement in the valve opening direction is restricted.
In the conventional expansion valve, the movement in the valve opening direction is restricted by the stopper member coming into contact with the receiving member. In contrast, in this embodiment, the dimension of the expansion valve in the height direction is limited. Can be shortened.
Further, since the receiving member 120 is not interposed between the stopper member 62 and the valve body 10, the vertical position of the stopper member 62 is not affected by the thickness of the receiving member 120, so the position of the diaphragm 130 is stabilized, There is less variation in individual performance.

FIG. 3 is an explanatory view showing another embodiment of the power element of the expansion valve of the present invention.
The power element 100 ′ is the same as the above-described embodiment in that the power element 100 ′ is composed of three members, that is, the upper lid member 110, the diaphragm 130, and the receiving member 120.
In this embodiment, a projection welding projection 114 is provided on the upper lid 110 side. The projection 114 is ring-shaped, and projection welding is performed with the electrodes 200 and 210 to seal the working gas in the pressure working chamber 112.
Also in this embodiment, the same operational effects as those of the embodiment of FIGS. 1 and 2 can be obtained.

DESCRIPTION OF SYMBOLS 10 Valve main body 12 Cylindrical part 12a Caulking part 20 Inlet port 22 Small diameter hole 24 Valve chamber 25 Valve seat 26 Valve hole 28 Outlet port 30 Return path 40 Valve member 42 Support member 44 Coil spring 50 Plug 52 Screw part 53 Hexagon hole 54 Seal member 60 Valve Rod 62 Stopper Member 64 Seal Member 66 Spring Member 70 Through Hole 80 Screw Hole 100, 100 ′ Power Element 110 Upper Cover Member 112 Pressure Actuation Chamber 114 Protrusion 120 Receiving Member 122 Opening 124 Protrusion 130 Diaphragm 200, 210 Electrode

Claims (5)

An inlet port for introducing a high-pressure liquid refrigerant, a valve chamber communicating with the inlet port, a valve hole provided in the valve chamber, and an outlet port for leading the refrigerant expanded in the valve hole to the outside Enclosed with a valve body having a valve member that opens and closes the valve hole by opening and closing the valve seat provided at the inlet of the valve hole, a valve rod that moves the valve member, and a working gas that drives the valve rod An expansion valve comprising:
The power element includes an upper lid member that forms a pressure working chamber in which the working gas is sealed, a receiving member, and a diaphragm sandwiched between the upper lid member and the receiving member,
The upper lid member, the diaphragm, and the receiving member are expansion valves that are joined by projection welding in an atmosphere filled with the working gas.   The expansion valve according to claim 1, wherein the valve body has a cylindrical portion into which the power element is inserted, and the power element is caulked and fixed to the valve body by pushing and bending the cylindrical portion inward.   The valve stem is in contact with the diaphragm via a stopper member, the receiving member is ring-shaped, and a gap is formed between an inner peripheral portion thereof and an outer peripheral portion of the stopper member. The expansion valve according to claim 1 or 2, wherein movement in the valve opening direction is restricted by contacting the valve body.   The expansion valve according to claim 1, wherein the receiving member has a ring-shaped projection for projection welding.   The expansion valve according to claim 1, wherein the upper lid member has a ring-shaped projection for projection welding.

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