JP3920060B2 - Expansion valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an expansion valve, and in particular, a high-temperature / high-pressure liquid refrigerant is adiabatically expanded into a low-temperature / low-pressure gas-liquid mixed refrigerant in a refrigeration cycle of an automotive air conditioner system, and the state of the refrigerant at an evaporator outlet is predetermined. The present invention relates to an expansion valve that controls the flow rate of refrigerant so that the degree of superheat is reached.
[0002]
[Prior art]
In automotive air conditioner systems, high-temperature and high-pressure gas refrigerant compressed by a compressor is condensed by a condenser, and the condensed liquid refrigerant is adiabatically expanded by an expansion valve to form a low-temperature and low-pressure refrigerant, which is evaporated by an evaporator. Thus, a refrigeration cycle that returns to the compressor is formed. The evaporator supplied with the low-temperature refrigerant is cooled by exchanging heat with the air in the passenger compartment.
[0003]
The expansion valve senses changes in the temperature and pressure of the refrigerant on the evaporator outlet side, and controls the flow rate of refrigerant supplied to the evaporator inlet side based on the temperature rise and fall pressure of the temperature sensing part. And a valve portion to be configured. 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 communicating the refrigerant inlet for receiving the high-pressure refrigerant and the refrigerant outlet for supplying the low-pressure refrigerant, It consists of the valve body provided so that contact and separation were possible facing the hole. The valve body is urged by a spring in a direction to close the valve hole, and is controlled by a temperature sensing unit via a shaft to control the valve opening.
[0004]
Such an expansion valve is attached to the inlet pipe and outlet pipe of the evaporator, but the piping work between the expansion valve and the evaporator is very complicated, so the expansion valve is integrated with the evaporator to perform piping work. It has been proposed to mitigate.
[0005]
As an example, an evaporator with an expansion valve described in JP-A-63-80169 is known. According to this evaporator, a plurality of plates are laminated so that refrigerant flow passages and air circulation spaces are alternately formed, and a plurality of refrigerant flow passages are grouped at both ends of the laminated plates in the refrigerant flow direction. Tanks to be assembled are formed, and these tanks are appropriately connected to form a continuous refrigerant flow. The tank is provided with an expansion valve pipe to which a high pressure pipe for introducing a high pressure liquid refrigerant and a low pressure pipe constituting an evaporator outlet pipe are connected, 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. The cylinder block includes a valve section that adiabatically expands the high-pressure liquid refrigerant and a control section that controls the valve body of the valve section by sensing the temperature and pressure of the refrigerant at the evaporator outlet.
[0006]
The pipe for the expansion valve is provided with a hole for supplying the adiabatic and expanded refrigerant to the evaporator inlet and a hole for allowing the refrigerant at the evaporator outlet to pass through the side wall of the cylinder block communicating with these holes. The refrigerant flow passage is sealed by a seal ring disposed between the expansion valve pipe and the cylinder block.
[0007]
[Problems to be solved by the invention]
However, the conventional expansion valve has a structure in which a solid cylindrical body is machined and the valve body and the temperature sensing part for driving it are accommodated therein, so that the body part becomes expensive. 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 and the assembly of the expansion valve is poor There was a point.
[0008]
The present invention has been made in view of these points, and an object of the present invention is to provide an expansion valve that is inexpensive and easy to assemble.
[0009]
[Means for Solving the Problems]
In the present invention, in order to solve the above problem, in the expansion valve that is attached to a valve case that is integrally welded adjacent to the inlet side tank and the outlet side tank of the evaporator, the refrigerant in the outlet side tank A temperature sensing part having a diaphragm for sensing the temperature and pressure of the gas, a part constituting a room of the temperature sensing part for introducing the refrigerant in the outlet side tank, a first in which the refrigerant is introduced or led out A valve portion having a housing having an outer shape in which a portion constituting the chamber and a portion constituting the second chamber into which the refrigerant is led out or introduced are sequentially reduced in diameter, and the housing includes the temperature sensing portion. A first opening for introducing the refrigerant in the outlet side tank into a part constituting the room, a second opening for leading the introduced refrigerant to the outside, and a part constituting the first room First And the opening of the expansion valve, characterized in that it has a fourth opening that communicates with the portion constituting the second chamber is provided.
[0010]
According to such an expansion valve, the housing forming the body of the valve portion is gradually reduced in diameter in a direction away from the temperature sensing portion, so that it can be mounted simply by placing it on the valve case formed accordingly. Assembling property can be improved.
[0011]
Further, according to the present invention, the housing is a press-processed product formed integrally with the lower housing of the temperature sensing portion, and the first press-processed product that partitions the space between the first chamber and the second chamber. The first plate is hermetically joined, and the second plate of the press-processed product that partitions between the first chamber and the temperature sensing chamber is hermetically joined.
[0012]
Thereby, like the housing of a temperature sensing part, the cost of an expansion valve can be reduced by comprising the housing of a valve part, and the 1st and 2nd plate by the cheap press work goods.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a partially enlarged cross-sectional view showing a state in which an expansion valve according to the present invention is mounted on an evaporator, FIG. 2 is a front view of the evaporator mounted with the expansion valve according to the present invention, and FIG. 3 shows an evaporator mounted with the expansion valve according to the present invention. It is a partial cross section side view.
[0014]
The expansion valve 1 according to the present invention is mounted by being inserted into a shallow valve case 3 integrally formed on the outside of the evaporator 2 and fixed to the valve case 3 with a fixing bracket 4.
[0015]
The evaporator 2 has two plate-like heat exchange panels in which a plurality of refrigerant flow passages and air flow passages are alternately arranged, and two other heat exchange panels arranged on top of each other so as to be integrated. Each of the heat exchange panels is provided with a tank at each end in the fluid flow direction to collect the refrigerant flow passages, and the tanks of adjacent panels are connected to each other so that the refrigerant sequentially flows through the heat exchange panels. It is like that.
[0016]
The illustrated evaporator 2 shows a case where an inlet side tank 5 that receives the refrigerant from the expansion valve 1 and an outlet side tank 6 that collects the evaporated refrigerant are arranged adjacent to each other in parallel. A valve case 3 for mounting the expansion valve 1 is attached to a space between the outlet side tank 6 and the outlet side tank 6.
[0017]
The valve case 3 has a shape that is widened upward in the figure, and a side wall of the valve case 3 expands from a refrigerant inlet pipe 7 that receives high-pressure liquid refrigerant condensed by a condenser and an outlet side tank 6. A refrigerant outlet pipe 8 for leading the refrigerant that has passed through the valve 1 to the compressor is connected. Further, the valve case 3 has a refrigerant outlet opening 9 for supplying a low-temperature / low-pressure refrigerant adiabatically expanded by the expansion valve 1 at a portion in contact with the inlet side tank 5, and is in contact with the outlet side tank 6. In the portion where the refrigerant is collected, a refrigerant introduction opening 10 is provided for introducing the refrigerant collected in the outlet side tank 6 into the temperature sensing portion and sensing the temperature and pressure.
[0018]
The valve case 3 is not in contact with the inlet side tank 5 except for a portion connected to the inlet side tank 5 through the refrigerant outlet opening 9. This prevents the low temperature of the refrigerant introduced into the inlet side tank 5 from the refrigerant outlet opening 9 from being directly transferred from the inlet side tank 5 to the portion of the valve case 3 where the temperature sensing part of the expansion valve 1 is located. This prevents the temperature sensing unit from causing a temperature sensing error.
[0019]
In the expansion valve 1, the temperature sensing part and the housing of the valve part are formed of a pressed product. That is, the lower housing 11 of the temperature sensing part and the housing 12 of the valve part are integrally formed by press working, and the upper housing 13 of the temperature sensing part is welded thereto. The housing 12 of the valve portion has an outer shape in which a portion constituting the temperature sensing portion, a portion constituting the high pressure chamber, and a portion constituting the low pressure chamber are sequentially reduced in diameter, and the high pressure chamber is included therein. And a plate 14 of a press-processed product for partitioning between the low-pressure chamber and a plate 15 of a press-processed product for partitioning the high-pressure chamber and the temperature-sensitive room. The plate 14 has a valve hole formed in the center, and is aligned substantially concentrically with the housing 12 and is hermetically joined to the inner wall of the housing 12 by projection welding. 14, the entire circumference of the housing 12 is airtightly joined to the inner wall of the housing 12 by projection welding in a state of being positioned so as to be exactly concentric with the body 14, thereby constituting the body of the valve portion. The housing 12 also has an opening communicating with the low pressure chamber, an opening communicating with the high pressure chamber (not shown in the figure), and an opening communicating with the room of the temperature sensing unit, and further has a lower end. In the illustrated example, four protruding pieces 16 are integrally provided on the portion. As for this protrusion piece 16, each front-end | tip is bent inside.
[0020]
In the low-pressure chamber of the housing 12, a ball-shaped valve body 17 that is movable back and forth in the axial direction with respect to the valve hole of the plate 14 is disposed. The valve body 17 is closed in a direction to close the valve hole by the compression coil spring 18. It is energized. The lower end of the compression coil spring 18 is received by the bent portion of the protruding piece 16. The set value of the expansion valve 1 at which the valve body 17 starts to open is adjusted by changing the load of the compression coil spring 18 by deforming the bent portion of the protruding piece 16 inward in the axial direction.
[0021]
The central portion of the plate 15 has a shaft through-hole through which the shaft 19 disposed at the axial position is inserted, and is formed in a shape that holds the packing 20. The packing 20 supports the shaft 19 so as to be able to advance and retreat in the axial direction and seals between the high pressure chamber and the temperature sensing chamber, and is held by press-fitting and fixing a washer to a portion holding the packing 20. Yes.
[0022]
The temperature sensing part is partitioned into upper and lower rooms by a diaphragm 21. A center disk 22 with good thermal conductivity disposed in contact with the diaphragm 21 is disposed in the lower room of the temperature sensing section, and the displacement of the diaphragm 21 is transmitted to the valve body 17 via the shaft 19. The center disk 22 also transfers the temperature of the refrigerant introduced from the outlet side tank 6 directly to the diaphragm 21. The upper chamber of the temperature sensing portion is filled with the same gas as the refrigerant, and the gas introduction hole formed in the center of the upper housing 13 is closed by welding the ball 23.
[0023]
As described above, in the expansion valve 1 according to the present invention, the housing 12 and the plates 14 and 15 constituting the body of the valve portion are configured by inexpensive press-worked products, and the load adjustment of the compression coil spring 18 is integrated with the housing 12. Cost reduction is realized by performing the deformation by deforming the bent portion of the projecting piece 16 and reducing the size in the axial direction. Further, the expansion valve 1 has a button shape and is mounted on the shallow valve case 3 and fixed, thereby improving the assemblability.
[0024]
When the expansion valve 1 is mounted on the valve case 3, the opening communicating with the low pressure chamber, the opening communicating with the high pressure chamber, and the opening communicating with the temperature sensing chamber are mutually fluid. Three seal rings are arranged so as to be isolated from each other.
[0025]
In the expansion valve 1 having the above-described configuration, the refrigerant collected in the outlet side tank 6 of the evaporator 2 is introduced into the room of the temperature sensing part through the refrigerant introduction opening 10 of the valve case 3. It passes through the room and is sent from the refrigerant outlet pipe 8 to the compressor. At this time, the diaphragm 21 of the temperature sensing unit senses the temperature and pressure of the refrigerant passing therethrough.
[0026]
Here, when the temperature of the refrigerant in the outlet side tank 6 decreases or the refrigerant pressure increases, the diaphragm 21 is displaced upward. As a result, the shaft 19 and the valve body 17 are pushed by the compression coil spring 18 and moved upward, and the valve opening is reduced. As a result, the flow rate of the refrigerant flowing from the refrigerant inlet pipe 7 through the valve case 3 and the expansion valve 1 to the evaporator 2 again through the valve case 3 and the inlet side tank 5 decreases.
[0027]
Conversely, when the temperature of the refrigerant in the outlet side tank 6 increases or the refrigerant pressure decreases, the diaphragm 21 is displaced downward. Thus, the shaft 19 and the valve body 17 are controlled to move downward against the urging force of the compression coil spring 18 so that the valve opening is increased. As a result, the flow rate of the refrigerant sent to the evaporator 2 through the valve portion of the expansion valve 1 increases.
[0028]
FIG. 4 is a partially enlarged sectional view showing a state in which the expansion valve according to the present invention is mounted on the evaporator while changing its orientation, FIG. 5 is a front view of the evaporator equipped with the expansion valve according to the present invention, and FIG. It is a fragmentary sectional top view of the mounted evaporator. In these drawings, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals.
[0029]
In this type of evaporator 2 a, an inlet side tank 5 and an outlet side tank 6 are arranged adjacent to each other in parallel, and the expansion valve 1 is disposed between the inlet side tank 5 and the outer end side of the outlet side tank 6. A valve case 3 to be mounted is provided. The valve case 3 has a shape that is expanded toward the front direction, and the expansion valve 1 is mounted from the lateral direction.
[0030]
This valve case 3 has a refrigerant outlet opening 9 for supplying a low-temperature and low-pressure refrigerant adiabatically expanded by the expansion valve 1 to the inlet side tank 5 of the evaporator at the bottom, and a high-pressure liquid refrigerant on the side wall. The refrigerant inlet pipe 7 for introducing the refrigerant, the refrigerant inlet opening 10 having a slit shape that is elongated in the circumferential direction for introducing the refrigerant collected in the outlet side tank 6, and the refrigerant outlet pipe 8 are connected. Opening.
[0031]
In the evaporator 2 a as described above, the expansion valve 1 is mounted in the valve case 3 from the lateral direction, and the expansion valve 1 is fixed to the valve case 3 using the fixing bracket 4. As a result, the high-pressure liquid refrigerant introduced from the refrigerant inlet pipe 7 enters the expansion valve 1 through the valve case 3, is adiabatically expanded by the expansion valve 1, and enters the inlet side tank 5 from the refrigerant outlet opening 9. Supplied. The refrigerant evaporated in the evaporator 2a is collected in the outlet side tank 6 and introduced into the room of the temperature sensing part of the expansion valve 1 through the refrigerant introduction opening 10 of the valve case 3, and this temperature sensing part It passes through the room and is sent from the refrigerant outlet pipe 8 to the compressor.
[0032]
In the expansion valve 1 having the above configuration, the plates 14 and 15 are projection welded to the housing 12. However, the plates 14 and 15 may be press-fitted into the housing 12 so that the entire circumference is airtightly joined. .
[0033]
Further, in the above embodiment, the refrigerant collected in the outlet side tank 6 is allowed to pass through the room of the temperature sensing unit, but only a part of the refrigerant may be allowed to flow.
[0034]
【The invention's effect】
As described above, in the present invention, the housing of the expansion valve has a button shape whose axial length is shorter than the conventional elongated cylindrical shape and whose diameter is gradually reduced in the direction away from the temperature sensing portion. Therefore, it is easy to mount on a shallow valve case formed integrally with the evaporator, and the assemblability can be improved.
[0035]
In addition, the expansion valve of the present invention comprises a temperature-sensitive part and a housing for the valve part, a high-pressure chamber, a low-pressure chamber, and a plate for partitioning the temperature-sensitive part, which are made of an inexpensive press product. Can be made at low cost, and the temperature and pressure of the outlet refrigerant of the evaporator can be reliably sensed by allowing the outlet refrigerant of the evaporator to pass through the room of the temperature sensing section.
[0036]
Furthermore, the load adjustment of the compression coil spring that urges the valve body in the valve closing direction is performed by deforming the bent part of the protruding piece formed integrally with the housing inward in the axial direction. The adjustment screw used is not necessary, and the cost of the expansion valve can be further reduced by reducing the number of parts.
[Brief description of the drawings]
FIG. 1 is a partially enlarged sectional view showing a state in which an expansion valve according to the present invention is mounted on an evaporator.
FIG. 2 is a front view of an evaporator equipped with an expansion valve according to the present invention.
FIG. 3 is a partial cross-sectional side view of an evaporator equipped with an expansion valve according to the present invention.
FIG. 4 is a partially enlarged sectional view showing a state in which the expansion valve according to the present invention is mounted on the evaporator while changing its direction.
FIG. 5 is a front view of an evaporator equipped with an expansion valve according to the present invention.
FIG. 6 is a partial sectional plan view of an evaporator equipped with an expansion valve according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Expansion valve 2, 2a Evaporator 3 Valve case 4 Fixing metal fitting 5 Inlet side tank 6 Outlet side tank 7 Refrigerant inlet piping 8 Refrigerant outlet piping 9 Refrigerant outlet opening 10 Lower inlet 12 Lower housing 12 Housing 13 Upper housing 14 , 15 Plate 16 Projection piece 17 Valve element 18 Compression coil spring 19 Shaft 20 Packing 21 Diaphragm 22 Center disk 23 Ball

Claims (6)

In the expansion valve designed to be attached to a valve case welded integrally adjacent to the inlet side tank and the outlet side tank of the evaporator,
A temperature sensing unit having a diaphragm for sensing the temperature and pressure of the refrigerant in the outlet side tank;
The portion constituting the room of the temperature sensing portion for introducing the refrigerant in the outlet side tank, the portion constituting the first chamber where the refrigerant is introduced or led out, and the second chamber where the refrigerant is led out or introduced A valve portion having a housing with an outer shape in which the diameters of the portions are sequentially reduced in diameter,
With
The housing has a first opening for introducing the refrigerant in the outlet side tank into a portion constituting the room of the temperature sensing unit, a second opening for leading the introduced refrigerant to the outside, and the first An expansion valve comprising: a third opening communicating with a portion constituting the second chamber; and a fourth opening communicating with a portion constituting the second chamber. The housing is a press-processed product formed integrally with the lower housing of the temperature-sensing part, and a first plate of the press-processed product that partitions the first chamber and the second chamber is provided on the housing. 2. The expansion valve according to claim 1, wherein the second plate of the press-processed product that is airtightly bonded and partitions the space between the first chamber and the temperature sensing portion is hermetically bonded. . The first plate has a valve hole in the center, and the second plate has a shaft through hole in the center that is centered on the same axis as the center of the valve hole. The expansion valve according to claim 2. A valve body disposed in the second chamber so as to be movable forward and backward in the axial direction with respect to the valve hole, a spring for biasing the valve body toward the valve hole, the shaft through hole, and the valve hole The expansion valve according to claim 3, further comprising: a shaft that penetrates at an axial position of the shaft and transmits a displacement of the diaphragm to the valve body. The second plate is formed in a shape that supports the shaft so as to be able to advance and retreat in the axial direction at an axial position, and holds a packing for sealing a gap between the shaft and the shaft through hole. The expansion valve according to claim 4. Projecting from the end of the housing forming the second chamber, the tip is bent to receive the spring, and the load of the spring can be adjusted by the bending angle of the tip. 5. The expansion valve according to claim 4, further comprising at least one protruding piece integrally formed with the housing.

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