JP2003083643A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve excellent in assembling properties in a state of a seal ring being fitted. SOLUTION: Three O rings 13, 14 and 15 necessary for isolating refrigerant passages communicating with a refrigerant introducing chamber 7 of a temperature sensing part 2 and the first and the second chambers 9 and 10 of a valve part when they are fitted to a valve case 22, are connected by connection parts 16 and molded integrally. Thereby the diameter of a housing of the valve part 3 to which the O rings 13, 14 and 15 are fitted is reduced in the direction of insertion into the valve case 22. According to this constitution, the O rings integrally formed hardly fall off, while independent O rings are apt to fall off on the occasion of insertion. Since the three O rings 13, 14 and 15 can be fitted collectively to the valve part 3, in addition, assembling properties in a state of the seal ring being fitted are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve.
The present invention relates to an expansion valve that adiabatically expands a high-pressure liquid refrigerant into a low-temperature low-pressure gas-liquid mixed refrigerant, and controls the refrigerant flow rate so that the refrigerant at the evaporator outlet has a predetermined superheat degree.

[0002]

2. Description of the Related Art In an automobile air conditioner system, a high temperature and high pressure gas refrigerant compressed by a compressor is condensed by a radiator, and the condensed liquid refrigerant is adiabatically expanded by an expansion valve into a low temperature and low pressure refrigerant, which is converted into a low temperature and low pressure refrigerant. A refrigeration cycle is formed in which an evaporator is used to evaporate and return it to the compressor. The evaporator supplied with the low-temperature refrigerant exchanges heat with the air in the vehicle compartment to perform cooling.

The expansion valve senses a change in the temperature and pressure of the refrigerant at the evaporator outlet side and raises or lowers the pressure inside the temperature sensing section, and the refrigerant supplied to the evaporator inlet side based on the pressure rising or lowering of the temperature sensing section. It is composed of a valve section for controlling the flow rate. The valve portion includes a valve hole formed in a wall provided so as to block the refrigerant passage in the middle of a refrigerant passage that communicates a refrigerant inlet for receiving a high-pressure refrigerant and a refrigerant outlet for supplying a low-pressure refrigerant, and the valve hole. The valve body is provided so as to be opposed to the hole so as to be able to come into contact with and separate from the hole. The valve body is biased by a spring in a direction to close the valve hole, and is controlled by the temperature sensing unit via the shaft to control the valve opening degree.

Such an expansion valve is attached to the inlet pipe and the outlet pipe of the evaporator, but since the piping work between the expansion valve and the evaporator is very complicated, the expansion valve is constructed integrally with the evaporator. It has been proposed to reduce piping work.

As one example, Japanese Patent Laid-Open No. 63-80169.
An evaporator with an expansion valve described in Japanese Patent Publication is known. According to this evaporator, a plurality of plates are laminated so that the refrigerant flow passages and the air circulation spaces are alternately formed, and the plurality of refrigerant flow passages are grouped at both ends of the laminated plates in the refrigerant flow direction. Tanks for assembly are formed and these tanks are appropriately connected to provide a continuous flow of refrigerant. Inside the tank, a high-pressure pipe for introducing high-pressure liquid refrigerant and a low-pressure pipe that constitutes the evaporator outlet pipe are connected to an expansion valve pipe, and one end of the expansion valve pipe extends outside the evaporator. From there, the cylinder block constituting the expansion valve is inserted into the expansion valve pipe. This cylinder block is provided with a valve section for adiabatically expanding the high-pressure liquid refrigerant and a control section for sensing the temperature and pressure of the refrigerant at the evaporator outlet to control the valve element of the valve section.

The expansion valve pipe has a side wall provided with a hole for supplying the adiabatic expanded refrigerant to the evaporator inlet and a hole for allowing the refrigerant at the evaporator outlet to pass therethrough, and communicates with these holes. The refrigerant flow passage of the cylinder block is sealed by a seal ring arranged between the expansion valve pipe and the cylinder block.

[0007] The applicant of the present invention has filed Japanese Patent Application No. 2000-21.
No. 9744 proposes an expansion valve that is formed to expand outward in the middle of the inlet side piping of an evaporator and is inserted and fixed in a valve case whose large diameter portion is open to the atmosphere. is doing. Such an expansion valve is equipped with a diaphragm-type temperature sensing unit in which a diaphragm that senses the temperature and pressure of the refrigerant is sandwiched between an upper housing and a lower housing, and a chamber is formed on both sides of this diaphragm. . The valve case is integrally formed of aluminum, which is the same as the evaporator and the piping, and the housing of the temperature sensing portion is formed of stainless steel.

[0008]

However, since the conventional expansion valve has a structure in which the solid cylindrical body is machined and the valve body and the temperature sensitive portion for driving the valve body are housed therein, When inserting the expansion valve into the expansion valve pipe with the seal ring attached, there is a risk that the hole provided in the expansion valve pipe may break the seal ring, resulting in poor assembly of the expansion valve. was there.

Further, in the expansion valve which is inserted into the valve case from the side open to the atmosphere and fixed, the outer peripheral part of the housing of the temperature sensing part is closely adhered to the large diameter outer peripheral part of the valve case. This is the part that is exposed to the atmosphere, and because the potential difference (standard electrode potential) between the stainless steel of the temperature sensing part and the aluminum of the valve case is large, moisture between these metals is large. However, there is a problem in that the contact phenomenon of dissimilar metals occurs and corrodes the valve case made of aluminum.

The present invention has been made in view of the above points, and has an excellent assembling property with a seal ring attached, and further, an expansion valve in which dissimilar metal contact corrosion phenomenon does not occur when it is attached to a valve case. The purpose is to provide.

[0011]

In order to solve the above problems, the present invention is designed to be mounted on a valve case integrally welded to a space between an inlet side tank and an outlet side tank of an evaporator. In the valve, a temperature-sensing part that senses the temperature and pressure of the refrigerant in the outlet-side tank, and a part that constitutes the room of the temperature-sensing part for introducing the refrigerant in the outlet-side tank, the refrigerant is introduced or led out. And a valve portion having a housing having an outer shape in which the portion forming the first chamber and the portion forming the second chamber from which the refrigerant is discharged or introduced are sequentially reduced in diameter, and the diameter of the housing is reduced sequentially. The first seal ring and the second seal ring which are arranged in the stepped portion
Connecting the third seal ring, the third seal ring, the first seal ring and the second seal ring, and the second seal ring and the third seal ring to each other. And a seal member integrally formed with and, the expansion valve is provided.

According to such an expansion valve, since the first to third seal rings have the integrally formed seal member, the seal member can be attached to the valve portion only once. Moreover, when the first to third seal rings attached to the valve portion are independent, since the expansion valve is reduced in diameter in the insertion direction into the valve case, it is easy to fall off. Since these are integrally formed, they are unlikely to fall off and the assemblability with the seal ring attached is improved.

Further, according to the present invention, the seal member has the electrically insulating thin film packing integrally formed so as to spread outward from the first seal ring. As a result, when it is mounted on the valve case, the packing is interposed between the lower housing of the temperature sensing portion and the valve case, so that no potential difference occurs even if water is present between them,
Since the phenomenon of dissimilar metal contact corrosion does not occur, the valve case will not be corroded.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is an exploded explanatory view showing a relationship between an expansion valve according to the present invention and an evaporator, FIG. 2 is a plan view of a seal member, FIG. 3 is a front view showing a state in which the expansion valve according to the present invention is mounted on an evaporator, and FIG. It is a figure which shows an example of a fixing metal fitting, (A) shows the side surface of a fixing metal fitting,
(B) shows the plane of the fixing bracket.

The expansion valve 1 according to the present invention comprises a temperature sensing portion 2 and a valve portion 3 which are integrally formed, and a seal member 4. The temperature sensing section 2 has a gas filling chamber 6 and a refrigerant introduction chamber 7 which are partitioned by a diaphragm 5. The gas filling chamber 6 is filled with the same gas as the refrigerant, and the refrigerant introducing chamber 7 has an opening 8 through which the refrigerant is introduced and the diaphragm 5 adjusts the temperature and pressure of the refrigerant. I am able to detect it.

Below the temperature sensing section 2, a first room 9 and a second room 10 are provided. The first chamber 9 is provided with an opening 11 for introducing a high-temperature and high-pressure liquid refrigerant, and the second chamber 10 has an open lower portion,
An opening 12 is provided for leading out the low-temperature and low-pressure refrigerant that has passed through the valve portion 3.

The lower housing of the temperature sensing part 2 and the housing of the valve part 3 are integrally formed, and the upper housing of the temperature sensing part 2 is welded thereto. The lower housing of the temperature sensing part 2 and the housing of the valve part 3 which are integrally formed are stepped in a portion forming the refrigerant introduction chamber 7 of the temperature sensing part 2 and the first chamber 9 and the second chamber 10 of the valve part 3. Parts are provided, and the refrigerant introduction chamber 7, the first chamber 9 and the second chamber 10 of the valve unit 3 have an outer shape in which the diameter is gradually reduced stepwise. The seal member 4 is fitted into these stepped portions.

As shown in the plan view of FIG. 2 as well, the sealing member 4 comprises three O-rings 13, 14, 15 and a plurality of thin connecting portions 16 for connecting them to each other. Is molded into. O-rings 13, 14, 1
5 is a refrigerant introduction chamber 7, a first chamber 9 and a second chamber of the valve unit 3.
Has an inner diameter corresponding to the outer diameter of the housing forming the chamber 10. Preferably, the inner diameter of at least one of the O-rings 13, 14, 15 is set to be slightly smaller than the outer diameter of the housing at the place where it is mounted. As a result, when the seal member 4 is fitted in the stepped portion of the housing, the seal member 4 does not drop off from the valve portion. Further, since the three O-rings 13, 14 and 15 are connected by the connecting portion 16, the valve portion 3 can be mounted at the same time.

Such an expansion valve 1 has an evaporator 21.
It is inserted into a shallow valve case 22 formed integrally on the outer side of, and is fixedly mounted by a fixing metal fitting 23. The evaporator 21 is formed by arranging two flat plate heat exchange panels in which a plurality of refrigerant flow passages and air flow passages are alternately arranged, and further arranging two other heat exchange panels so as to be integrated. With such a configuration, tanks are provided at both ends of each heat exchange panel in the fluid flow direction to collect the refrigerant flow passages, and the tanks of adjacent panels are communicated with each other so that the refrigerant sequentially flows through each heat exchange panel. It is like this.

The evaporator 21 shown in the figure shows a case where an inlet side tank 24 for receiving the refrigerant from the expansion valve 1 and an outlet side tank 25 through which the evaporated refrigerant flows out are adjacently arranged in parallel. Inlet tank 24 and outlet tank 2
Valve case 22 for mounting the expansion valve 1 in the space between
Is attached.

The valve case 22 has a shape expanded and formed upward in the drawing, and a side wall of the valve case 22 is connected to a refrigerant inlet pipe 26 for receiving a high-pressure liquid refrigerant condensed by a condenser. . Refrigerant outlet pipe 27 of evaporator 21
Is directly connected to the outlet side tank 25.

The evaporator 21 has an inlet tank 2
4, a refrigerant introduction opening 28 is provided on the inner side surface, and a refrigerant sensing opening 29 is provided on the inner side surface of the outlet side tank 25. The valve case 22 has a refrigerant outlet opening 30 that supplies the low-temperature low-pressure refrigerant adiabatically expanded by the expansion valve 1 at a position aligned with the refrigerant inlet opening 28 of the inlet tank 24. A coolant sensing opening 31 is provided at a position aligned with the coolant sensing opening 29 of 25 so that the temperature and pressure of the coolant flowing out of the evaporator 21 can be sensed. Although not shown, the valve case 22 also has a refrigerant introduction opening for introducing high-pressure liquid refrigerant into a portion to which the refrigerant inlet pipe 26 is connected.

The valve case 22 is composed of the evaporator 21.
At the same time when the plates constituting the above are welded in the furnace, they are welded and integrated with the evaporator 21 at the same time. The expansion valve 1 is inserted into such a valve case 22, and these are fixed metal fittings 23.
Fixed by. The fixing member 23 has a slit-shaped opening 32 on the opposite side surface of an elastic strip formed in a substantially U shape, for example. With the expansion valve 1 inserted in the valve case 22, the fixing metal fitting 23 is pushed laterally into a portion where the entire circumference welded portion of the temperature sensing portion and the flange portion of the valve case 22 overlap each other, so that the overlapping portion Fits into the slit-shaped opening 32, whereby the expansion valve 1
And the valve case 22 are fixed.

FIG. 5 is a plan view showing another form of the seal member, FIG. 6 is a sectional view taken along the line aa of FIG. 5, and FIG. 7 is a longitudinal sectional view of a main part showing a state in which the expansion valve is attached to the evaporator. is there.
In these figures, the same components as those shown in FIGS. 1 to 4 are designated by the same reference numerals.

This seal member 4a is composed of three O-rings 1.
3, 14, 15 and a plurality of connecting portions 16 for connecting these to each other, and a thin film packing 33 formed so as to spread upward from the outer O-ring 13, and the packing 33 has an outer peripheral edge. Is provided with a bead 34. The O-rings 13, 14, 15, the connecting portion 16, the packing 33, and the bead 34 are integrally formed of a non-conductive and flexible material such as rubber.

When the expansion valve 1 is inserted into the valve case 22 and these are fixed by the fixing fittings 23, as shown in FIG. 7, the expansion valve 1 is provided between the outer peripheral welded portion of the temperature sensing portion 2 and the flange portion of the valve case 22. There is packing. As a result, the housing of the expansion valve 1 and the valve case 22 that are exposed to the atmosphere
And are electrically insulated by the packing 33. Here, the housing of the expansion valve 1 is made of stainless steel and the valve case 22 is made of aluminum. However, even if water is present between these dissimilar metals, these are packed 33.
Since it is electrically insulated by the above, a potential difference does not occur, and a corrosion phenomenon of dissimilar metal contact does not occur to corrode the aluminum valve case.

Further, the aluminum valve case 22 is
Although it also contacts the fixing bracket 23,
By plating chromium having a small potential difference with aluminum, electrolytic corrosion on the valve case 22 is reduced.

[0028]

As described above, according to the present invention, when installed in the valve case, the room of the temperature sensing portion required as the expansion valve, the first room into which the refrigerant is introduced or discharged, and the refrigerant are The three seal rings required for isolating the refrigerant passage communicating with the second chamber that is led out or introduced are connected and integrally molded. As a result, since the housing of the valve part to which the seal ring is attached is reduced in diameter in the insertion direction into the valve case, the separate seal ring was likely to fall off during insertion, but these are integrally formed. By doing so, it is difficult for the valve to come off, and since the three seal rings can be attached to the valve part at once, the assembling property with the seal rings attached is improved.

Further, according to the present invention, there is provided an electrically insulating thin film packing integrally formed so as to spread outward from the seal ring provided in the lower housing of the temperature sensing portion. As a result, when mounted on the valve case,
Since the packing electrically insulates between the lower housing of the temperature sensing part and the valve case, the corrosion of the dissimilar metal does not occur even if moisture intervenes between them, so the valve case corrodes. Disappears.

[Brief description of drawings]

FIG. 1 is an exploded explanatory view showing a relationship between an expansion valve and an evaporator according to the present invention.

FIG. 2 is a plan view of a seal member.

FIG. 3 is a front view showing a state in which the expansion valve according to the present invention is attached to an evaporator.

FIG. 4 is a diagram showing an example of a fixing metal fitting, (A) showing a side surface of the fixing metal fitting, and (B) showing a flat surface of the fixing metal fitting.

FIG. 5 is a plan view showing another form of the seal member.

6 is a cross-sectional view taken along the line aa of FIG.

FIG. 7 is a longitudinal sectional view of an essential part showing a state in which an expansion valve is attached to an evaporator.

[Explanation of symbols]

1 expansion valve 2 temperature sensing part 3 valve 4,4a Seal member 5 diaphragm 6 gas filling chamber 7 Refrigerant introduction chamber 8 openings 9 First room 10 Second room 11 openings 12 openings 13,14,15 O-ring 16 Connection 21 Evaporator 22 valve case 23 Fixing bracket 24 Inlet tank 25 Exit side tank 26 Refrigerant inlet piping 27 Refrigerant outlet pipe 28 Refrigerant introduction opening 29 Refrigerant sensing opening 30 Refrigerant outlet 31 Refrigerant sensing opening 32 openings 33 packing 34 beads

Claims (4)

[Claims] 1. An expansion valve mounted on a valve case integrally welded to a space between an inlet side tank and an outlet side tank of an evaporator, wherein the refrigerant temperature and pressure in the outlet side tank are controlled. A temperature-sensing part for sensing, a part forming a room of the temperature-sensing part for introducing the refrigerant in the outlet side tank, a part forming a first room for introducing or drawing out the refrigerant, and a refrigerant discharging or A valve portion having a housing whose outer diameter is gradually reduced in a part that constitutes a second chamber to be introduced, a first seal ring disposed in a step portion of the housing that is gradually reduced in diameter, The second seal ring and the third seal ring, the first seal ring and the second seal ring, and the second seal ring and the third seal ring are interconnected. An expansion valve, comprising: a seal member integrally formed with a connecting portion; 2. The seal member includes the first to third members.
2. The expansion valve according to claim 1, wherein at least one inner diameter of the seal ring is smaller than an outer diameter of the housing where it is mounted. 3. The seal member has a thin film packing having an electrically insulating property, which is integrally formed so as to extend outward from the first seal ring. Expansion valve described. 4. The expansion valve according to claim 3, wherein the seal member has a bead on an outer peripheral edge of the packing.