JP2003075025A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve low in cost and excellent in assemblability. SOLUTION: A lower housing 12 of a temperature sensor and a body 13 of a valve part are integrally molded through press working, and joined to an upper housing 14 of the temperature sensor by welding. Partitioning is effected by welding plates 15 and 16, being a pressed product, to the body 13 between a high pressure chamber, in which a refrigerant is introduced, and a low pressure chamber from which a refrigerant is led through and between the high pressure chamber and the temperature sensor. The load of a compression coil spring 23 to energize a valve body 22 in a valve closing direction is regulated by the bending way of the spring support part of a load regulating piece 21 formed integrally with the body 13, and a need for an adjust screw is eliminated. Further, by decreasing a size in the direction of an axis, a size is decreased. This constitution enables reduction of a cost of an expansion valve 1. Since the expansion valve 1 has a button shape, mounting on a valve case formed integrally with an evaporator is facilitated and assemblability is 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]

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, The part of the body becomes expensive, and 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 will break the seal ring, There has been a problem that the assembling property of the expansion valve is poor.

The present invention has been made in view of the above points, and an object of the present invention is to provide an inexpensive expansion valve which is easy to assemble.

[0009]

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 having a diaphragm for sensing the temperature and pressure of the refrigerant in the outlet-side tank, and a part constituting the room of the temperature-sensing part for introducing the refrigerant in the outlet-side tank, A valve portion having a body having an outer shape in which a portion forming a first chamber into which a refrigerant is introduced or led out and a portion constituting a second chamber from which a refrigerant is led out or introduced are gradually reduced in diameter stepwise;
An expansion valve is provided which is characterized by including.

According to such an expansion valve, since the body is gradually reduced in diameter in the direction away from the temperature sensing portion, it can be mounted simply by mounting it on a valve case formed in accordance with this. Can be improved.

Further, according to the present invention, the body is a press-worked product formed integrally with the lower housing of the temperature-sensing part, and the press-working for partitioning the first chamber and the second chamber is formed on the body. While joining the first plate of the product airtightly,
A second plate, which is a pressed product that partitions the first chamber from the temperature-sensitive chamber, is airtightly joined.

As a result, the body of the valve portion and the first and second plates are made of pressed products, as in the housing of the temperature sensing portion, so that the body can be manufactured at low cost and the cost of the expansion valve can be reduced. Can be reduced.

[0013]

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 a longitudinal sectional view showing the structure of an expansion valve according to the first embodiment, FIG. 2 is a front view of an evaporator equipped with the expansion valve according to the first embodiment, and FIG. 3 is a view of the first embodiment. FIG. 4 is a side view of the evaporator equipped with the expansion valve according to the embodiment, and FIG. 4 is a sectional view taken along the line aa of FIG.

Expansion valve 1 according to the first embodiment of the present invention
Is attached to a shallow-bottom valve case 3 formed integrally on the outside of the evaporator 2 and fixed by a fixing bracket 4 for use.
The evaporator 2 has two flat heat exchange panels in which a plurality of refrigerant flow passages and a plurality of air flow passages are alternately arranged, and another two heat exchange panels are further arranged so as to be integrated with each other. 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 2 shown in the figure shows a case where an inlet side tank 5 for receiving the refrigerant from the expansion valve 1 and an outlet side tank 6 through which the evaporated refrigerant flows out 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 inlet side tank 5 and the outlet side tank 6.

The valve case 3 has a shape expanded and formed upward in the drawing, and a side wall of the valve case 3 is connected with a refrigerant inlet pipe 7 for receiving a high-pressure liquid refrigerant condensed by a condenser. . The refrigerant outlet pipe 8 of the evaporator 2 is directly connected to the outlet side tank 6. Also, the valve case 3 is
A refrigerant introduction opening 9 for introducing a high-pressure liquid refrigerant is provided in a portion to which the refrigerant inlet pipe 7 is connected, and a low temperature adiabatically expanded by the expansion valve 1 is provided in a portion in contact with the inlet tank 5. A refrigerant outlet opening 10 for supplying low-pressure refrigerant, and a refrigerant sensing opening for sensing the temperature and pressure of the refrigerant exiting the evaporator 2 in a portion in contact with the outlet tank 6. Have 11.

Further, the valve case 3 is provided so as not to come into contact with the inlet side tank 5 except for a portion connected to the inlet side tank 5 through the refrigerant outlet opening 10. This prevents the low temperature of the refrigerant introduced into the inlet side tank 5 from the refrigerant outlet opening 10 from being directly transferred from the inlet side tank 5 to the portion of the valve case 3 where the temperature sensing portion of the expansion valve 1 is located. , It prevents the temperature sensing part from causing a temperature sensing error.

In the expansion valve 1, the housing of the temperature sensing portion and the body of the valve portion are formed by press work. That is, the lower housing 12 of the temperature sensing part and the body 13 of the valve part are integrally formed by press working, and the upper housing 14 of the temperature sensing part is welded thereto. The body 13 has an outer shape in which a part forming a room of the temperature sensing part, a part forming a high pressure chamber, and a part forming a low pressure chamber are gradually reduced in diameter, and the high pressure chamber and the low pressure chamber are included therein. And a plate 15 of a pressed product for partitioning between the high pressure chamber and the temperature-sensitive room. The plate 15 has a valve hole 17 formed in the center thereof, and
Almost concentrically with each other, the entire circumference is airtightly joined to the inner wall of the body 13 by projection welding. Plate 16
With the jig, the entire circumference is airtightly joined to the inner wall of the body 13 by projection welding while being positioned so as to be accurately concentric with the plate 15. Body 13
Has an opening portion 18 communicating with the low pressure chamber, an opening portion 19 communicating with the high pressure chamber, and an opening portion 20 communicating with the temperature sensing chamber of the temperature sensing portion, and further, a load adjusting piece at the lower end portion. 21 is projected.

In the low pressure chamber of the body 13, a ball-shaped valve body 22 is arranged which can move forward and backward in the axial direction with respect to the valve hole 17 of the plate 15, and the valve body 22 is compressed by a compression coil spring 23. It is biased in the direction of closing 17. The adjustment of the set value of the expansion valve 1 at which the valve body 22 starts to open is performed by adjusting the bending angle of the load adjusting piece 21 to adjust the load of the compression coil spring 23.

The central portion of the plate 16 has a shaft through hole through which the shaft 24 arranged at the axial position is inserted, and is formed in a shape for holding the packing 25. The packing 25 supports the shaft 24 so as to move back and forth in the axial direction and seals between the high-pressure chamber and the temperature-sensitive chamber.
Is held in the part that holds. This washer 26
Is fixed to the portion holding the packing 25 by press fitting or the like.

The temperature sensitive section is divided into upper and lower chambers by a diaphragm 27. A center disk 28 having a good thermal conductivity is arranged in the lower room of the temperature sensing section so that the displacement of the diaphragm 27 is transmitted to the valve body 22 via the shaft 24. The outer peripheral portion of the center disk 28 is disposed in the vicinity of the opening 20 that communicates with the outlet side tank 6, and directly determines the temperature of the refrigerant in the outlet side tank 6 and indirectly through the valve case 3 and the body 13. I am trying to detect it. The room above the temperature sensing part is filled with the same gas as the refrigerant, and the gas introduction hole formed in the center of the upper housing 14 is closed by welding the ball 29.

As described above, the expansion valve 1 according to the present invention is
The body 13 and the plates 15 and 16 are made of inexpensive pressed products, and the load of the compression coil spring 23 is adjusted by bending the load adjusting piece 21 formed integrally with the body 13, and the axial dimension is set. The cost has been reduced by shortening and shortening the size. Further, the expansion valve 1 has a button shape and is attached to and fixed to the shallow-bottom valve case 3, thereby improving the assemblability.

When the expansion valve 1 is mounted on the valve case 3, the opening 18 and the opening 19 are separated from each other, the opening 19 and the opening 20 are separated from each other, and the opening 20 and the valve case 3 are separated from each other. A seal ring is arranged between the opening and the peripheral edge to fluidly seal between them.

Next, the positional relationship of the openings through which the refrigerant flows among the expansion valve 1, the valve case 3 and the evaporator 2 will be described. 5 is a cross-sectional view for explaining the positional relationship between the body of the expansion valve, the valve case, and the opening of the evaporator, FIG. 6 is a partial plan view showing the evaporator before welding the valve case, and FIG. 7 is welding the valve case. FIG. 8 is a partial plan view showing the evaporator after the operation, and FIG. 8 is a partial plan view showing a state in which the body of the expansion valve is arranged in the valve case. In addition, in order to avoid complicating the drawing, the expansion valve has plates 15, 16
Also, only the body 13 before welding the upper housing 14 of the temperature sensing portion is shown.

The inlet tank 5 of the evaporator 2 has a refrigerant introduction opening 30 at a position aligned with the refrigerant outlet opening 10 of the valve case 3, and is aligned with the refrigerant sensing opening 11 of the valve case 3. At the position of the outlet side tank 6, a slit-shaped refrigerant sensing opening 31 is provided.

The body 13 of the expansion valve 1 is provided with, for example, four slit-shaped openings 19 for introducing high-pressure liquid refrigerant, and a refrigerant sensing opening 31 of the outlet side tank 6 and a refrigerant sensing of the valve case 3 are provided. There are provided, for example, four slit-shaped openings 20 for introducing the refrigerant flowing out of the evaporator 2 via the opening 11 for use. This opening 20
Is the opening 2 whose circumferential length is adjacent in the circumferential direction.
It is set to be sufficiently longer than the length in the circumferential direction between 0 and 0. Accordingly, when the expansion valve 1 is mounted on the valve case 3, even if the opening 20 of the expansion valve 1 is not accurately aligned with the refrigerant sensing opening 11 of the valve case 3, the adjacent opening 2
Since 0s partially overlap each other, the refrigerant in the outlet tank 6 can be reliably detected.

In the expansion valve 1 having the above structure, the temperature of the refrigerant collected in the outlet side tank 6 of the evaporator 2 is transmitted to the temperature sensing section of the expansion valve 1 mainly through the outlet side tank 6 and the valve case 3. At the same time, it is heated and the refrigerant pressure is transmitted to the room below the temperature sensing portion through the refrigerant sensing opening 31 of the outlet side tank 6 and the refrigerant sensing opening 11 of the valve case 3. Here, when the temperature of the refrigerant in the outlet side tank 6 decreases or the refrigerant pressure rises, the diaphragm 27 is displaced upward. As a result, the shaft 24 and the valve element 22 are pushed by the compression coil spring 23 and moved upward, and the valve opening degree becomes smaller. As a result, the refrigerant is introduced through the refrigerant inlet pipe 7, the refrigerant introduction opening 9 of the valve case 3 and the opening 19 of the expansion valve 1, and the opening 18 of the expansion valve 1 and the refrigerant derivation opening 10 of the valve case 3. Also, the flow rate of the refrigerant introduced into the evaporator 2 via the refrigerant introduction opening 30 of the inlet side tank 5 is reduced.

On the contrary, when the temperature of the refrigerant in the outlet side tank 6 rises or the refrigerant pressure falls, the diaphragm 27 is
Displaces downward. As a result, the shaft 24 and the valve body 22 move downward against the biasing force of the compression coil spring 23, and the valve opening degree is controlled to increase. As a result, the flow rate of the refrigerant sent to the evaporator 2 via the valve portion of the expansion valve 1 increases.

FIG. 9 is a front view of another type of evaporator equipped with the expansion valve according to the first embodiment, and FIG. 10 is the first view.
FIG. 7 is a side view of another type of evaporator equipped with the expansion valve according to the embodiment of FIG. 9 and 10, the same elements as those shown in FIGS. 2 and 3 are designated by the same reference numerals.

In this type of evaporator 2a, an inlet side tank 5 for receiving the refrigerant from the expansion valve 1 and an outlet side tank 6 through which the evaporated refrigerant flows out are arranged on the same line. A valve case 3 for mounting the expansion valve 1 is attached to a space between the outlet side tank 6.

The inlet side tank 5 and the outlet side tank 6 are
A refrigerant introduction opening 30 and a refrigerant sensing opening 31 are provided on opposing wall surfaces in the longitudinal direction, respectively, and the valve case 3 has a refrigerant derivation opening 10 and a refrigerant sensing opening 11 respectively. It is welded to the evaporator 2a in alignment with the refrigerant sensing opening 31. Expansion valve 1
It is mounted on such a valve case 3 and is fixed by a fixing bracket 4.

FIG. 11 is a partial vertical sectional view showing a state in which the expansion valve according to the second embodiment is attached to the evaporator, FIG.
2 is a plan view showing a center disk of the expansion valve according to the second embodiment. FIG. 11 and 12, the same elements as those shown in FIGS. 1 and 5 are designated by the same reference numerals.

Expansion valve 41 according to the second embodiment
A temperature-sensing fin 28b that directly senses the temperature of the refrigerant in the outlet-side tank 6 is connected to a center disk 28a arranged between the diaphragm 27 and the shaft 24.
The center disk 28a and the temperature-sensitive fins 28b are integrally formed by pressing an aluminum plate having good thermal conductivity. The temperature sensitive fin 28b is
Projects outside the expansion valve 41 through the opening 20,
When the expansion valve 41 is attached to the valve case 3, a length sufficient to enter the outlet side tank 6 through the refrigerant sensing opening 11 of the valve case 3 and the refrigerant sensing opening 31 of the outlet side tank 6 is required. Have The other configuration of the expansion valve 41 is the same as the configuration of the expansion valve 1 of the first embodiment.

The temperature sensing fins 28 are attached to the center disk 28a.
By providing b, the temperature of the refrigerant in the outlet side tank 6 can be directly sensed and the heat can be transferred to the center disk 28a, whereby the temperature sensitivity can be improved.

FIG. 13 is a longitudinal sectional view showing an expansion valve according to the third embodiment, and FIG. 14 is a view showing a compression coil spring of the expansion valve according to the third embodiment. A vertical section, (B) is a bottom view. 13, the same elements as those shown in FIG. 1 are designated by the same reference numerals.

Expansion valve 51 according to the third embodiment
Is integrally formed with, for example, three load adjusting pieces 21a evenly arranged on the circumference at the lower end of the body 13,
The lower end portions of the load adjusting pieces 21a are respectively bent inward and have a wedge-shaped claw 21b at the tip.
The compression coil spring 23a that biases the valve body 22 toward the plate 15 is a conical spring whose outer diameter on the valve body 22 side is small. The outer diameter of the compression coil spring 23a on the large diameter side is the claw 2 of the load adjusting piece 21a.
The diameter is set larger than the diameter of the inscribed circle of 1b, and the claw 21b is inserted between the pitches of the wire rods. Therefore,
The tips of the claws 21b are arranged so as to be displaced in the axial direction according to the pitch of the compression coil spring 23a. Further, the large diameter side tip of the compression coil spring 23a is bent inward to form a knob 23b at the time of load adjustment. The other configuration of the expansion valve 51 is the same as the configuration of the expansion valve 1 of the first embodiment.

The expansion valve 51 having the above-mentioned structure pushes the compression coil spring 23a into the opening surrounded by the claw 21b, and after the compression coil spring 23a is engaged with the claw 21b, the knob 23b is used. The compression coil spring 23a can be screwed inward by rotating. In this way, the compression coil spring 23
A can change its load by itself and can adjust the set value of this expansion valve 51. After adjustment,
A lock agent is applied to the portion of the claw 21b to fix the compression coil spring 23a to the claw 21b.

FIG. 15 is a vertical sectional view showing an expansion valve according to the fourth embodiment. 15, the same elements as those shown in FIG. 1 are designated by the same reference numerals. The expansion valve 61 according to the fourth embodiment is, for example, four, which is suspended from the lower end of the body 13 and is evenly arranged on the circumference.
The load adjusting piece 21c of the book is integrally formed. The lower end portions of the load adjusting pieces 21c respectively form spring supports for the compression coil springs 23 that are bent inward to urge the valve body 22 toward the plate 15. The other configuration of the expansion valve 61 is the same as the configuration of the expansion valve 1 of the first embodiment.

In the expansion valve 61 having the above construction, the valve body 22 and the compression coil spring 23 are mounted at the time of assembly, and then the tip end of the load adjusting piece 21c is bent.
At this time, the bending of the load adjusting piece 21c is performed so that the load of the compression coil spring 23 becomes the target load or becomes smaller than the target load. That is, when the set value of the expansion valve 61 may be a rough value that is not strict, the tip of the load adjusting piece 21c is bent so that the load of the compression coil spring 23 becomes the target load, and the expansion valve 61 is not adjusted. Used in. On the other hand, when a strict set value is required, the tip end of the load adjusting piece 21c is bent so that the load of the compression coil spring 23 becomes smaller than the target load during assembly, and at the time of adjustment, The load of the compression coil spring 23 is adjusted by deforming the tip of the load adjusting piece 21c inward in the axial direction.

FIG. 16 is a vertical sectional view showing an expansion valve according to the fifth embodiment. 16, the same elements as those shown in FIG. 1 are designated by the same reference numerals. In the expansion valve 71 according to the fifth embodiment, a plate 15a, the outer peripheral end of which is press-molded into a tubular shape, is press-fitted into a portion of the body 13 which constitutes the low pressure chamber so as to partition the high pressure chamber and the low pressure chamber. Similarly, the plate 16a, the outer peripheral end of which is press-molded into a tubular shape, is press-fitted into a portion of the body 13 which constitutes the high-pressure chamber to partition the high-pressure chamber from the temperature-sensitive chamber.

The expansion valve 71 having the above-described structure is provided in the plate 15
Since the a and the plate 16a are press-fitted into the body 13, they are positioned so that they are automatically concentric when press-fitted, and at the same time the entire circumference is airtightly joined.

In the expansion valves 1, 41, 51, 61, 71 of the first to fifth embodiments, the plate 1
Although the high temperature and high pressure refrigerant is introduced into the central room partitioned by the plates 5 and 15a and the plates 16 and 16a, the adiabatic expanded low temperature and low pressure refrigerant is introduced from the lower room in the figure. A high temperature / high pressure refrigerant may be introduced into the room on the lower end side of the drawing, and adiabatic expanded low temperature / low pressure refrigerant may be drawn from the central room.

[0043]

As described above, according to the present invention, the body of the expansion valve has a shorter axial length than the conventional elongated cylindrical shape, and the diameter is gradually reduced in the direction away from the temperature sensing portion. The button shape makes it easy to attach to the shallow valve case that is formed integrally with the evaporator.
The assemblability can be improved.

Further, the expansion valve of the present invention is conventionally expensive because the housing and body of the temperature sensing portion and the valve portion and the plate partitioning the high pressure chamber, the low pressure chamber and the temperature sensing portion are made of an inexpensive press work product. Since the body can be made at a low cost, and the axial dimension is shortened and downsized,
The cost of the expansion valve can be further reduced.

Further, since the load of the compression coil spring for urging the valve body in the valve closing direction is adjusted by bending the load adjusting piece formed integrally with the body, the adjuster used in the conventional load adjusting is adjusted. By eliminating the need for screws and reducing the number of parts, the cost of the expansion valve can be further reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a configuration of an expansion valve according to a first embodiment.

FIG. 2 is a front view of an evaporator equipped with the expansion valve according to the first embodiment.

FIG. 3 is a side view of an evaporator equipped with the expansion valve according to the first embodiment.

FIG. 4 is a sectional view taken along the line aa of FIG.

FIG. 5 is a cross-sectional view for explaining the positional relationship between the body of the expansion valve, the valve case, and the opening of the evaporator.

FIG. 6 is a partial plan view showing the evaporator before welding the valve case.

FIG. 7 is a partial plan view showing the evaporator after welding the valve case.

FIG. 8 is a partial plan view showing a state where the body of the expansion valve is arranged in the valve case.

FIG. 9 is a front view of another type of evaporator equipped with the expansion valve according to the first embodiment.

FIG. 10 is a side view of another type of evaporator equipped with the expansion valve according to the first embodiment.

FIG. 11 is a partial vertical cross-sectional view showing a state in which the expansion valve according to the second embodiment is attached to an evaporator.

FIG. 12 is a plan view showing a center disk of an expansion valve according to a second embodiment.

FIG. 13 is a vertical sectional view showing an expansion valve according to a third embodiment.

FIG. 14 is a view showing a compression coil spring of an expansion valve according to a third embodiment, (A) is a longitudinal section, (B) is a sectional view.
Is a bottom view.

FIG. 15 is a vertical sectional view showing an expansion valve according to a fourth embodiment.

FIG. 16 is a vertical sectional view showing an expansion valve according to a fifth embodiment.

[Explanation of symbols]

1 expansion valve 2,2a evaporator 3 valve case 4 fixing brackets 5 Inlet tank 6 Exit side tank 7 Refrigerant inlet piping 8 Refrigerant outlet piping 9 Refrigerant introduction opening 10 Refrigerant outlet 11 Refrigerant sensing opening 12 Lower housing 13 body 14 Upper housing 15,15a, 16,16a plate 17 valve hole 18,19,20 Opening 21 Load adjustment piece 21a Load adjustment piece 21b nail 21c Load adjustment piece 22 valve body 23 Compression coil spring 23a compression coil spring 23b knob 24 shaft 25 packing 26 washers 27 diaphragm 28, 28a Center disk 28b Thermal fin 29 balls 30 Refrigerant introduction opening 31 Refrigerant sensing opening 41,51,61,71 expansion valve

Claims (13)

[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 having a diaphragm for sensing, a part configuring a room of the temperature sensing part for introducing the refrigerant in the outlet side tank, a part configuring a first chamber in which the refrigerant is introduced or discharged. And a valve section having a body having an outer shape in which a portion of the second chamber through which the refrigerant is led out or introduced is gradually reduced in diameter stepwise, and an expansion valve. 2. The body is a press-formed product formed integrally with the lower housing of the temperature-sensing part, and a press-formed product for partitioning the first chamber and the second chamber. The first plate is airtightly joined, and the second plate of the pressed product that partitions the first chamber and the temperature sensitive chamber is also airtightly joined. The expansion valve according to 1. 3. The expansion valve according to claim 2, wherein the first plate and / or the second plate are joined to the body by welding. 4. The first plate and / or the second plate are joined by press-fitting to the body of the part forming the second chamber and the part of the part forming the first chamber. The expansion valve according to claim 2, wherein 5. A valve hole is formed in the central portion of the first plate, and a shaft through hole whose center is on the same axis as the center of the valve hole is formed in the second plate. The expansion valve according to claim 2, wherein 6. A valve body, which is arranged in the second chamber so as to be movable back and forth in the axial direction with respect to the valve hole, a spring for urging the valve body toward the valve hole, and the shaft penetrating member. An expansion valve according to claim 5, further comprising: a hole and a shaft penetratingly disposed at an axial position of the valve hole and transmitting a displacement of the diaphragm to the valve body. 7. The shape of the second plate, which supports the shaft so as to be movable back and forth in the axial direction at an axial position, and which holds a packing for sealing a gap between the shaft and the shaft through hole. The expansion valve according to claim 6, wherein the expansion valve is molded into. 8. A spring receiver for the spring is formed by projecting from an end of the body forming the second chamber and having a tip end bent to adjust a load of the spring according to an angle of the bend. 7. The expansion valve according to claim 6, further comprising at least one load adjusting piece integrally formed with the body capable of being formed. 9. A tip end portion having a claw bent inwardly protruding from an end portion of the body forming the second chamber is inserted between pitches of wire rods of the spring to receive the spring and the spring. 7. The expansion valve according to claim 6, further comprising a plurality of load adjusting pieces integrally formed with the body, wherein the load of the spring can be adjusted by itself according to the rotation angle of the expansion valve. 10. The body has a first opening communicating with the outlet side tank and a second opening communicating with the first chamber, and the first and second openings include: The expansion valve according to claim 1, wherein the expansion valve has an elongated shape in the circumferential direction of the body and is provided in plural in the circumferential direction of the body. 11. The first opening has a length in the circumferential direction that is sufficiently longer than a length in the circumferential direction between the openings adjacent to each other in the circumferential direction. The expansion valve according to claim 10. 12. A center disk having good thermal conductivity, which is in contact with the diaphragm of the temperature sensing part and is formed in a shape such that a part thereof is close to the opening communicating with the outlet side tank. The expansion valve according to claim 1, wherein: 13. The center disk has a temperature-sensitive fin, a part of which protrudes from an opening communicating with the outlet-side tank and is configured to directly sense the temperature of the refrigerant in the outlet-side tank. The expansion valve according to claim 12, wherein the expansion valve is provided.