JP2016191526A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve that can prevent corrosion due to moisture even when dew formation occurs and can prevent effects on an operation of a power element even when dew formation occurs.SOLUTION: An expansion valve includes: a valve body having an inlet port to which a high-pressure refrigerant is introduced, a valve chamber connected to the inlet port, a valve hole opened in the valve chamber, a valve seat formed at an inlet of the valve hole, and an outlet port from which the refrigerant passed through the valve hole is sent out; a valve member disposed facing the valve seat; and a power element that has a pressure operation chamber filled with working gas for driving a valve stem for operating the valve member. The power element is mounted to the upper surface of the valve body via a caulking portion that surrounds the power element, and a protection member is provided from the upper surface of the valve body over a height including the entire caulking portion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an expansion valve with a built-in temperature sensing mechanism used in a refrigeration cycle, and more particularly to an expansion valve that can maintain the stability of operating characteristics despite its simple structure.

Conventionally, for refrigeration cycles used in air conditioners installed in automobiles, a temperature expansion valve with a built-in temperature sensing mechanism that adjusts the refrigerant flow rate according to the temperature is used to save installation space and piping work. Has been. The valve body of such an expansion valve has an inlet port into which a 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 in the valve hole that opens to the valve chamber, and is operated by a valve rod driven by a power element to open a throttle passage between the valve seat and the valve seat. Control the degree.
Moreover, the refrigerant | coolant which passed the valve hole is sent to an evaporator side from an exit port. 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 is composed of an upper lid member that forms a pressure working chamber, a thin diaphragm that is elastically deformed under pressure, and a disk-shaped receiving member. Formed.
A working gas is enclosed in a pressure working chamber formed by the upper lid member and the diaphragm. At this time, 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 filling the working gas from this hole, the hole is closed with a steel ball or the like, and the pressure working chamber is sealed by projection welding means or the like. Stop.

The conventional temperature expansion valve with a built-in temperature sensing mechanism as described above is required to be further miniaturized because a large number of parts are arranged in close contact with each other. There is also an advantage that the manufacturing cost can be reduced by downsizing.
As a solution to such a problem, an expansion valve in which a power element is reduced in size is known (for example, see Patent Document 1). The power element of the expansion valve described in Patent Document 1 has a diaphragm that is sandwiched and fixed between the upper lid member and the receiving member, and the outer periphery of the upper lid member, the diaphragm, and the receiving member is laser welded. Are joined together.
The assembled power element is inserted into a cylindrical portion provided at the top of the valve body and fixed by a caulking portion formed by caulking.

JP 2012-197990 A

Since the low temperature refrigerant | coolant used by the refrigerating cycle etc. flows into a flow path in the expansion valve described in patent document 1, the temperature of a valve main body also becomes low with the said low temperature refrigerant | coolant.
At this time, when outside air around the expansion valve comes into contact with the caulking portion of the low-temperature valve body or the surface of the power element, moisture in the outside air may condense and form water droplets.

However, the conventional expansion valve described in Patent Document 1 can be reduced in size as a whole by fixing the power element to the valve body via the caulking portion, but between the caulking portion and the power element. Will cause a step.
Due to the presence of such a step, when the expansion valve is used for a long time, moisture contained in the outside air may condense and adhere to the upper surface of the power element inside the step.
At this time, since the valve body and the power element are made of different metals, the condensed moisture becomes an electrolyte and corrosion due to electrolytic corrosion occurs, and as a result, there is a concern that the durability of the crimped portion is lowered.

  In addition, when condensed moisture stays and forms a water film, a water film with different heat transfer performance is interposed on the upper surface of the power element instead of outside air (air), so the temperature characteristics of the working gas inside the power element change. As a result, the operating characteristics of the power element may change.

  Accordingly, an object of the present invention is to provide an expansion valve that does not cause corrosion due to moisture even if condensation occurs and does not affect the operation of the power element even if condensation occurs.

  In order to achieve the above object, an expansion valve according to the present invention includes an inlet port into which a high-pressure refrigerant is introduced, a valve chamber communicating with the inlet port, a valve hole opening in the valve chamber, A valve body having a valve seat formed at the inlet, an outlet port through which the refrigerant that has passed through the valve hole is sent out, a valve member disposed to face the valve seat, and a valve for operating the valve member A power element having a pressure working chamber enclosing a working gas for driving the rod, and the power element is attached to the upper surface of the valve body via a caulking portion surrounding the power element, and the upper surface of the valve body A protective member is provided over a height including the entire crimped portion.

In one aspect of the expansion valve of the present invention, the protection member is provided to a position higher than an upper end position of the power element.
Moreover, in another aspect of the expansion valve of the present invention, a peripheral wall portion surrounding the crimping portion is formed on the upper surface of the valve body, and the protection member is provided in an inner region of the peripheral wall portion. .

Moreover, the said surrounding wall part may be formed to the position higher than the upper end position of the said power element.
Furthermore, it is preferable that the protective member is formed of a resin material.

  By providing the above means, the expansion valve of the present invention does not cause corrosion due to moisture even if dew condensation occurs, and even if dew condensation occurs, the influence on the operation of the power element can be suppressed.

It is the longitudinal cross-sectional view (a) and right view (b) of the expansion valve by Example 1 of this invention. It is the longitudinal cross-sectional view (a) and right view (b) of the expansion valve by Example 2 of this invention. It is a top view of the expansion valve by Example 2 of this invention, and shows the case (a) of the expansion valve shown in FIG. 2, and the case (b) of the expansion valve in a modification. It is the schematic which shows the principal part of the expansion valve by Example 3 of this invention, and is the longitudinal cross-sectional view (a) in the filling process of a protection member, respectively, Top view (b) corresponding to this, The longitudinal cross-section after protection member formation It is a figure (c).

<Example 1>
1 is a longitudinal sectional view (a) and a right side view (b) of an expansion valve according to a first embodiment of the present invention.
As shown in FIG. 1, the valve body 10 of the expansion valve of the present invention is produced by machining an aluminum alloy extruded shape having a rectangular side view, for example, and is an inlet into which a high-pressure refrigerant is introduced. It has a port 20.
The inlet port 20 communicates with the valve chamber 24 of the valve body 10 through the small diameter hole 22. The valve chamber 24 communicates with a refrigerant outlet port 28 via a valve hole 26 formed coaxially with the valve rod 60.

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 of the valve body 10 by the screw portion 52. Therefore, the spring force of the coil spring 44 that supports the valve member 40 can be adjusted by adjusting the screwing amount of the plug 50.
A seal member 54 is provided on the outer peripheral portion of the plug 50, thereby sealing the valve chamber 24.

The refrigerant sent out from the outlet port 28 is sent to the evaporator, and the refrigerant returning from the evaporator to the compressor side enters the return passage 30 provided in the valve body 10 from the left side in the drawing and passes through it.
A power element 100 is attached to the top of the valve body 10 via a caulking portion 12 formed on the top of the valve body 10. A seal member 64 such as an O-ring is disposed between the power element 100 and the valve body 10.
The power element 100 includes an upper lid member 110, a ring-shaped receiving member 120, and a diaphragm 130 that is sandwiched between the upper lid member 110 and the receiving member 120. Further, a working gas is sealed in a pressure working chamber 112 composed of the upper lid member 110 and the diaphragm 130 and sealed with a plug 114.

A stopper member 62 is disposed on the lower surface of the diaphragm 130 so that 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 intermediate region of the valve stem 60. The spring member 66 prevents vibration of the valve member 40 by contacting the valve rod 60 and adding sliding resistance.
The valve body 10 is provided with two through holes 70 that penetrate the valve body 10 (see FIG. 1B), and is used as an insertion hole for a bolt that attaches the valve body 10 to another member. In addition, one bottomed screw hole 80 is also formed in the center of the valve body 10. The bottomed screw hole 80 is used as a screw hole for fixing a pipe joint.

As shown in FIG. 1, when the power element 100 is attached to the valve body 10 by the caulking portion 12, the caulking portion 12 is arranged in a manner that surrounds the upper surface of the power element 100. At this time, the caulking portion 12 is formed by bending a protruding portion formed in a cylindrical shape toward the power element 100 side.
On the other hand, since the valve body 10 has a low temperature due to the influence of the refrigerant flowing inside, the moisture in the outside air is condensed and attached to the upper surface of the power element 100 and the crimping portion 12 in contact with the upper surface of the power element 100. Corrosion may occur in the crimped portion due to electrolytic corrosion due to accumulation in the step of the portion.

Therefore, in the expansion valve according to the first embodiment of the present invention, the peripheral wall portion 14 surrounding the caulking portion 12 is erected at the upper end of the valve body 10, and the entire caulking portion 12 is formed in the inner region of the peripheral wall portion 14. The protective member 200 made of a resin such as rubber or urethane is filled up to the included height.
The protective member 200 may be formed by pouring a flowable rubber or resin and then curing it, or a previously formed shape is inserted or fitted into the inner region of the peripheral wall portion 14. May be provided. Further, the protective member 200 may be formed of a plastic material or a material having heat insulation properties.

With such a configuration, the expansion valve according to the first embodiment of the present invention is configured so that the caulking portion 12 is not exposed to the outside of the protective member 200 even if moisture contained in the surrounding outside air is condensed. As a result, it is possible to prevent the mounting portion of the power element 100 from being damaged without corrosion.
In addition, since the contact portion between the power element 100 and the caulking portion 12 is not exposed to the outside by the protective member 200, for example, even when the power element 100 and the caulking portion 12 are formed of members of different materials, It is possible to prevent electric corrosion.

Here, the protective member 200 shown in FIG. 1 is illustrated as being filled up to the height of the upper end of the peripheral wall portion 14. However, if the height is such that the entire caulking portion 12 can be included, than the peripheral wall portion 14. The above effect can be exhibited even at a low position.
However, if the protective member 200 is provided up to the same height as the upper end of the peripheral wall portion 14, the condensed water droplets do not stay on the upper surface of the protective member 200, and the upper surface of the valve body 10 can be made flat. For example, there is an advantage that it is easy to hold the upper and lower ends.

<Example 2>
FIG. 2 is a longitudinal sectional view (a) and a right side view (b) of an expansion valve according to a second embodiment of the present invention. Since the expansion valve according to the second embodiment has many parts in common with the expansion valve according to the first embodiment, here, description will be made with reference to the differences from the first embodiment.
As shown in FIG. 2, in the expansion valve according to the second embodiment of the present invention, the upper end of the peripheral wall portion 14 formed at the upper end of the valve body 10 is formed to be higher than the mounting height of the power element 100, and the peripheral wall The protection member 200 is filled up to a height at which the entire power element 100 is included in the inner region of the portion 14.

With such a configuration, the expansion valve according to the second embodiment of the present invention is configured so that the caulking portion 12 is not exposed to the outside of the protective member 200 even if moisture contained in the surrounding outside air is condensed. As a result, it is possible to prevent the mounting portion of the power element 100 from being damaged without being corroded.
In addition, since the entire power element 100 is not exposed to the outside by the protective member 200, the working gas filled in the power element 100 exhibits stable characteristics without being influenced by the external atmosphere. As a result, the operating characteristics of the temperature-sensitive expansion valve using the power element 100 can also be stabilized.

Furthermore, since the upper and lower ends of the expansion valve can be made flat by filling the protective member 200 to the height of the upper end 14a of the peripheral wall portion 14 formed in the valve body 10, the attachment of the expansion valve It is easy to hold the time, and since there is no protrusion, it is easy to form a seal structure.
Therefore, even in the shape design of an engine room or the like to which the expansion valve according to the present invention is attached, the effect of simplifying the structure of the expansion valve attachment portion is exhibited.

FIG. 3 is a top view showing a modification of the expansion valve according to the second embodiment of the present invention. FIG. 3A shows an outline of the expansion valve according to the second embodiment shown in FIG. 2, and FIG. 3B shows an outline of the expansion valve in the modification.
As shown in FIG. 3A, in the expansion valve of the present invention, when the peripheral wall portion 14 has the same rectangular shape as the outer shape of the valve body 10, an extruded profile is applied to the material forming the valve body 10. Moreover, since the peripheral wall part 14 can be formed by performing the cutting removal process of an upper end part after an extrusion process, a manufacturing process can be simplified.

On the other hand, as shown in FIG. 3B, the peripheral wall portion 14 may be formed in a circular shape (cylindrical shape) surrounding the power element (or the caulking portion that fixes the power element).
With such a shape, the amount of the protective member 200 to be filled can be minimized while maintaining the advantage of flattening the upper surface, so that the weight of the entire expansion valve can be reduced.

<Example 3>
FIG. 4 is a schematic view showing a main part of an expansion valve according to Embodiment 3 of the present invention. 4A is a longitudinal sectional view in the filling process of the protective member, FIG. 4B is a top view corresponding to FIG. 4A, and FIG. 4C is a longitudinal sectional view after forming the protective member. Show.
Also, the expansion valve according to the third embodiment also has many parts in common with the expansion valve according to the first embodiment, and therefore, here, description will be made with reference to the differences from the first embodiment.

In the expansion valve according to the third embodiment of the present invention, the protective member 200 that covers the crimped portion 12 and the power element 100 at the upper end of the valve body 10 is formed on the valve body 10 without using a peripheral wall portion.
That is, as shown in FIGS. 4A and 4B, when the protective member 200 is formed on the upper end of the valve body 10, the split mold 210 corresponding to the shape of the protective member 200 is used as the valve. It attaches so that the circumference | surroundings of the crimping | crimped part 12 of the main body 10 may be enclosed, and it hardens | cures, after pouring the fluid state material, such as resin, into the space formed inside these mold type | molds 210, for example.
Then, after the forming material of the protection member 200 is cured, the mold die 210 is divided and removed to include the crimping portion 12 and the power element 100 at the upper end of the valve body 10 as shown in FIG. The protective member 200 to remain remains.

With such a configuration, the expansion valve according to the third embodiment of the present invention is configured so that the caulking portion 12 is not exposed to the outside of the protective member 200 even if moisture contained in the surrounding outside air is condensed. As a result, it is possible to prevent the mounting portion of the power element 100 from being damaged without corrosion.
Moreover, since it is not necessary to form a surrounding wall part around the crimping part 12, the process of the valve main body 10 can be simplified and the weight of the entire expansion valve can be reduced.

The present invention is not limited to the above-described embodiments, and various modifications can be made.
For example, in the above-described second embodiment, the case where the outer shape of the peripheral wall portion 14 is rectangular or circular is illustrated, but the shape of the peripheral wall portion 14 can also be applied to the first embodiment.

Moreover, in Example 3, although the case where the external shape of the protection member 200 was made circular was illustrated, it is good also as a rectangular shape which covers the whole upper end of the valve main body 10. FIG.
Furthermore, in the third embodiment, the protective member 200 is made by pouring and hardening the material in a fluid state, but it may be provided so as to cover the crimping portion 12 and the power element 100 with a material that has been molded into a predetermined shape in advance. . In this case, there is an advantage that it is not necessary to use the mold 210 described above.

DESCRIPTION OF SYMBOLS 10 Valve main body 12 Caulking part 14 Perimeter wall part 20 Inlet port 24 Valve chamber 25 Valve seat 26 Valve hole 28 Outlet port 30 Return passage 40 Valve member 42 Support member 44 Coil spring 50 Plug 54 Seal member 60 Valve rod 62 Stopper member 64 Seal member DESCRIPTION OF SYMBOLS 100 Power element 110 Upper cover member 112 Pressure working chamber 113 Enclosure hole 114 Seal plug 120 Receiving member 121 Through hole 130 Diaphragm 200 Protection member 210 Mold type

Claims (5)

An inlet port into which a high-pressure refrigerant is introduced, a valve chamber communicating with the inlet port, a valve hole opening in the valve chamber, a valve seat formed at the inlet of the valve hole, and the valve hole A power having a valve main body having an outlet port through which refrigerant is sent out, a valve member disposed to face the valve seat, and a pressure working chamber in which a working gas for driving a valve rod for operating the valve member is enclosed. An expansion valve comprising an element,
The power element is attached to the upper surface of the valve body via a caulking portion that surrounds the power element,
An expansion valve, wherein a protection member is provided from a top surface of the valve main body to a height including the entire caulking portion. The expansion valve according to claim 1, wherein the protection member is provided up to a position higher than an upper end position of the power element. On the upper surface of the valve body, a peripheral wall portion surrounding the caulking portion is formed,
The expansion valve according to claim 1, wherein the protection member is provided in an inner region of the peripheral wall portion. The expansion valve according to claim 3, wherein the peripheral wall portion is formed to a position higher than an upper end position of the power element. The expansion valve according to claim 1, wherein the protection member is formed of a resin material.

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