JP6523746B2 - Expansion valve - Google Patents

Description

  The present invention relates to an expansion valve incorporating a temperature sensing mechanism used in a refrigeration cycle, and more particularly to an expansion valve capable of maintaining the stability of its operating characteristics despite its simple structure.

Conventionally, as for a refrigeration cycle used for an air conditioner installed in a car, a temperature expansion mechanism built-in type temperature expansion valve is used to adjust the passing amount of refrigerant according to the temperature in order to save installation space and piping work. It is done. The valve body of such an expansion valve has an inlet port into which a high pressure refrigerant is introduced, and a valve chamber in communication with the inlet port.
A spherical valve member disposed in the valve chamber faces the valve seat of the valve hole opening to the valve chamber and is operated by a valve rod driven by the power element to open the throttle passage between the valve seat and the valve seat. Control the degree.
Further, the refrigerant passing through the valve hole 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.

The top of the valve body is equipped with a drive mechanism for the valve member called the power element. The power element comprises an upper lid member forming a pressure working chamber and a thin plate diaphragm elastically deformable under pressure and a disk-like receiving member, and three members are superposed and a circumferential portion is joined by TIG welding means or the like. It is 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 seal the working gas in the pressure working chamber, a hole is provided at the top of the upper lid member, and after the working gas is sealed 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 above-described conventional temperature expansion mechanism-incorporating thermal expansion valve is required to be further miniaturized because a large number of parts are disposed in close contact with each other. Moreover, there is an advantage that manufacturing cost can be reduced by miniaturizing.
As a thing which solved such a subject, the expansion valve which aimed at size reduction of a power element is known (for example, refer to patent documents 1). The power element of the expansion valve described in Patent Document 1 has a diaphragm which is fixed by being sandwiched between the upper lid member and the receiving member, and the outer lid of the upper lid member, the diaphragm, and the receiving member is laser welded. It joins by.
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

In the expansion valve described in Patent Document 1, since a low temperature refrigerant used in a refrigeration cycle or the like flows in the flow path, the temperature of the valve main body is also lowered by the low temperature refrigerant.
At this time, when the ambient air around the expansion valve contacts the crimped portion of the low temperature valve body or the surface of the power element, the moisture in the ambient air may be condensed to form water droplets.

However, although the conventional expansion valve described in Patent Document 1 can realize the overall downsizing by fixing the power element to the valve body via the caulking portion, the space between the caulking portion and the power element can be realized. 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 be condensed to 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 water becomes an electrolyte to cause corrosion due to electrolytic corrosion, and as a result, there is a concern that the durability of the crimped portion may be reduced.

  In addition, when condensed water is retained and a water film is formed, not the outside air (air) but the water film having different heat transfer performance intervenes on the upper surface of the power element, so the temperature characteristic of the working gas inside the power element changes. There is also a possibility that the operation characteristics of the power element may change as a result.

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

In order to achieve the above object, the expansion valve of the present invention comprises an inlet port to which a high pressure refrigerant is introduced, a valve chamber in communication with the inlet port, a valve hole opened to the valve chamber, and a valve hole A valve body having a valve seat formed at an inlet and an outlet port from which the refrigerant having passed through the valve hole is delivered, a valve member disposed opposite to the valve seat, and a valve for operating the valve member And a power element having a pressure working chamber in which a working gas for driving a rod is enclosed, wherein 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 the height covering the entire caulking portion from the above, and a peripheral wall portion surrounding the caulking portion is formed on the upper surface of the valve main body, and the protective member includes the caulking portion and the caulking portion. Fill the space between the peripheral Characterized in that it is.

In one aspect of the expansion valve of the present invention, the protection member is provided to a position higher than the upper end position of the power element .

The peripheral wall portion may be formed to a position higher than the upper end position of the power element.
Furthermore, the protective member is preferably made of a resin material.

  By providing the above-described means, the expansion valve of the present invention can prevent corrosion due to moisture even when dew condensation occurs, and can suppress the influence on the operation of the power element even if dew condensation occurs.

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 a longitudinal cross-sectional view (a) in the filling process of a protection member, a top view corresponding to this (b), a longitudinal section after protection member formation It is a figure (c).

Example 1
FIG. 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 extruded section of aluminum alloy having a rectangular side view, for example, and an inlet to 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. Further, the valve chamber 24 communicates with the 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. Further, 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, by adjusting the screwing amount of the plug 50, the spring force of the coil spring 44 supporting the valve member 40 can be adjusted.
A seal member 54 is provided on the outer peripheral portion of the plug 50, whereby the valve chamber 24 is sealed.

The refrigerant discharged 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.
The 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. Further, 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 sandwiched between the upper lid member 110 and the receiving member 120. A working gas is sealed in a pressure working chamber 112 formed of the upper cover member 110 and the diaphragm 130 and sealed by a plug 114.

A stopper member 62 is disposed in contact with 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. In addition, a spring member 66 is disposed on the outer peripheral portion of the intermediate region of the valve rod 60. The spring member 66 prevents the vibration of the valve member 40 by contacting the valve rod 60 and applying a sliding resistance.
The valve body 10 is provided with two through holes 70 penetrating 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, a single bottomed screw hole 80 is also formed in the central portion 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 disposed in a manner to surround the upper surface of the power element 100. At this time, the crimped portion 12 is formed by bending a cylindrically formed protrusion 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 condenses and adheres to the upper surface of the power element 100 and the caulking portion 12 contacting this. Corrosion may occur in the crimped portion due to electrolytic corrosion due to being accumulated in the steps of the portion.

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

With such a configuration, in the expansion valve according to the first embodiment of the present invention, the caulking portion 12 is not exposed to the outside of the protective member 200 even if the moisture contained in the ambient air is condensed. As a result, corrosion of the mounting portion of the power element 100 can be prevented without corrosion.
Further, 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 the occurrence of electrolytic corrosion.

Here, although the case where the protection member 200 shown in FIG. 1 is filled up to the height of the upper end of the peripheral wall portion 14 is illustrated, if it is a height that can encompass the entire crimped portion 12, The above effects can be exhibited even at low positions.
However, if the protective member 200 is provided to the same height as the upper end of the peripheral wall portion 14, condensed water droplets do not stay on the upper surface of the protective member 200, and the upper surface of the valve main body 10 can be made flat. For example, there is an advantage that it becomes 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. Note that the expansion valve according to the second embodiment has many parts in common with the expansion valve according to the first embodiment, so here, the explanation will be given with reference to the differences from the case of 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 on the upper end of the valve main body 10 is formed to be higher than the mounting height of the power element 100 and the peripheral wall The protective member 200 is filled to the height at which the entire area of the power element 100 is included in the inner region of the portion 14.

With such a configuration, in the expansion valve according to the second embodiment of the present invention, the caulking portion 12 is not exposed to the outside of the protective member 200 even if the moisture contained in the ambient air is condensed. As a result, corrosion of the mounting portion of the power element 100 can be prevented without corrosion.
Further, since the entire power element 100 is not exposed to the outside by the protective member 200, the working gas filled inside 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 main body 10, attachment of the expansion valve At the same time, it becomes easy to form a seal structure because there is no protrusion.
Therefore, also in the shape design such as an engine room to which the expansion valve according to the present invention is attached, the effect of being able to simplify the structure of the mounting portion of the expansion valve is exhibited.

FIG. 3 is a top view showing a modification of the expansion valve according to the second embodiment of the present invention. 3 (a) shows an outline of the expansion valve according to the second embodiment shown in FIG. 2, and FIG. 3 (b) 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 main body 10, the extrusion is applied to the material forming the valve main body 10. In addition, since the peripheral wall portion 14 can be formed by performing the cutting and removing process on the upper end portion after the extrusion process, the manufacturing process can be simplified.

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

Example 3
FIG. 4 is a schematic view showing the main part of an expansion valve according to a third embodiment of the present invention. 4 (a) is a longitudinal sectional view in the step of filling the protective member, FIG. 4 (b) is a top view corresponding to FIG. 4 (a), and FIG. 4 (c) is a longitudinal sectional view after forming the protective member. Show.
In addition, since the expansion valve according to the third embodiment also has many parts in common with the expansion valve according to the first embodiment, the differences will be mainly described with reference to the difference from the first embodiment.

In the expansion valve according to the third embodiment of the present invention, a protective member 200 covering the crimped portion 12 and the power element 100 at the upper end of the valve main body 10 is formed on the valve main body 10 without using a peripheral wall.
That is, as shown in FIGS. 4A and 4B, when forming the protective member 200 on the upper end of the valve main body 10, the split mold 210 corresponding to the shape of the protective member 200 is used as a valve. It is attached so as to surround the caulking portion 12 of the main body 10, and a material in a fluid state such as a resin is poured into a space formed inside the molds 210 and then cured.
Then, after the forming material of the protective member 200 is cured, the mold 210 is divided and removed, and as shown in FIG. 4C, the upper end of the valve main body 10 includes the caulking portion 12 and the power element 100. Protection member 200 remains.

With such a configuration, in the expansion valve according to the third embodiment of the present invention, the caulking portion 12 is not exposed to the outside of the protective member 200 even if the moisture contained in the ambient air is condensed. As a result, corrosion of the mounting portion of the power element 100 can be prevented without corrosion.
Moreover, since it is not necessary to form a peripheral wall part around the caulking part 12, while being able to simplify processing of the valve main body 10, weight reduction of the whole expansion valve can be achieved.

The present invention is not limited to the above embodiments, and various modifications can be made.
For example, although the case where the external shape of the surrounding wall part 14 was made into rectangular shape or circular shape was illustrated in said Example 2, the shape of the said surrounding wall part 14 is applicable also to Example 1. FIG.

In the third embodiment, the outer shape of the protective member 200 is circular, but it may be rectangular so as to cover the entire top surface of the valve body 10.
Furthermore, in the third embodiment, although the protective member 200 is made to pour and harden the material in a fluid state, it may be provided to cover the caulking portion 12 and the power element 100 with a shape previously formed into a predetermined shape. . 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 peripheral 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 operation chamber 113 Sealing hole 114 Sealing plug 120 Receiving member 121 Through hole 130 Diaphragm 200 Protective member 210 Mold type

Claims (4)

An inlet port through which high-pressure refrigerant is introduced, a valve chamber communicating with the inlet port, a valve hole opened to the valve chamber, a valve seat formed at the inlet of the valve hole, and the valve hole Power having a valve body having an outlet port through which refrigerant is discharged, a valve member disposed opposite to the valve seat, and a pressure working chamber in which a working gas for driving a valve rod for operating the valve member is sealed An expansion valve including an element,
The power element is attached to an upper surface of the valve body via a caulking portion surrounding the power element,
A protection member is provided from the upper surface of the valve body to a height covering the entire caulking portion ,
A peripheral wall portion surrounding the caulking portion is formed on the upper surface of the valve body,
An expansion valve , wherein the protective member is filled between the caulking portion and the peripheral wall portion . The expansion valve according to claim 1, wherein the protection member is provided to a position higher than the upper end position of the power element. The expansion valve according to claim 1 or 2 , wherein the peripheral wall portion is formed to a position higher than the upper end position of the power element. The expansion valve according to any one of claims 1 to 3 , wherein the protective member is made of a resin material.

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