JPH0989154A - Temperature-type expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more precisely control the opening of an expansion oriffice depending on the temperature of low-pressure refrigerant, by decreasing the effect of the atmospheric temperature in relation to a temperature sensing bar of the expansion valve. SOLUTION: In a temperature-type expansion valve, a valve main body 41 is formed of resin, and the valve main body 41 is provided with a throttle mechanism 46 composed of an orifice 47 and a valve element 48 formed of metallic members, and an operating rod 69 for operating the valve element 48, and a control mechanism 54 for controlling the throttle mechanism 46 according to the temperature of refrigerant to be fed out from an evaporator 5 toward a compressor 1. Moreover, the valve main body 41 and the control mechanism 54 are fixed by caulking. A metallic collar 71 is arranged on an attaching hole part 70 of the valve main body 41 in relation to a pipe attaching flange. A temperature sensing rod 65 is held by two-point supporting of a first slide hole 63 and a second slide hole 64.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature type expansion valve used in a refrigerating cycle of an air conditioner, which evaporates in response to the temperature of a refrigerant sent from an evaporator 5 of the refrigerating cycle toward a compressor 1. The present invention relates to a thermal expansion valve for automatically controlling the amount of refrigerant entering the container 5.

[0002]

2. Description of the Related Art FIG. 6 is a vertical cross-sectional view showing a state in which a conventional temperature type expansion valve 4 is incorporated in a refrigeration cycle of an automobile air conditioner. It is equipped with a vessel 2, a receiver 3, an expansion valve 4 and an evaporator 5. The compressor 1 is driven by receiving the rotational force of an automobile engine via an electromagnetic clutch (not shown). The condenser 2 condenses the high-temperature and high-pressure gaseous refrigerant adiabatically compressed by the compressor 1 by exchanging heat with air outside the vehicle compartment to form a liquid refrigerant. The receiver 3 has a built-in dryer (not shown) for temporarily storing the liquid refrigerant cooled by the condenser 2 and removing moisture and dust in the refrigerant. The expansion valve 4 adiabatically expands the liquid refrigerant into a low-temperature and low-pressure mist refrigerant. The evaporator 5 vaporizes the mist refrigerant by heat exchange with air sent into the vehicle interior.

As shown in FIG. 6, a conventional expansion valve 4 has a rectangular parallelepiped metal valve body 6 in which a first flow path 7 communicating with an outlet of a condenser 2 and an inlet of an evaporator are communicated with each other. And a third flow passage 9 that connects the outlet of the evaporator 5 and the inlet of the compressor 1 to each other. The throttling mechanism 13 is arranged in the inner part of the first flow path 7 and has an orifice 25, a valve body 27, and a compression coil spring 29. The orifice 25 is formed in the valve body 6 for communicating the first flow path and the second flow path, and has an inlet opening into the valve chamber 12, and a valve is provided around the inlet. A seat 26 is formed. The valve body 26 is biased toward the valve seat 26 by a compression coil spring 29. The valve body 27 abuts the valve seat 26 to close the orifice 25 and separate from the valve seat 26. The orifice 25 is opened.

The right side of the third flow passage 9 is connected to the compressor 1, and the compressor 1 is connected to the first flow passage 7 via the condenser 2 and the receiver 3. . Also,
The left side of the third flow path 9 is connected to the evaporator 5, and the evaporator 5 is connected to the second flow path 8.

On the other hand, on the upper portion of the valve body 6, an upper lid 16 and
A control mechanism 14 including a lower lid 18 and a diaphragm 17 made of a stainless steel thin plate sandwiched between the upper lid 16 and the lower lid 18 includes a pressure equalizing chamber of the valve body 6 in an airtight manner via a packing 20. The screw is fastened to the upper portion of 11 and an adhesive is applied to the screw portion 18b to prevent the screw from loosening.

A saturated vapor gas is filled in the heat sensitive chamber 10 formed by the upper lid 16 and the diaphragm 16. The saturated vapor gas is sealed in the heat sensitive chamber 10 by the upper lid 16
The pipe steam chamber 10 is filled with the saturated vapor gas from the pipe 33 integrally connected by brazing, and then the inner side of the pipe is crushed slightly to make a temporary airtight state.
The tip of 3 is permanently sealed with solder or the like.

The central portion of the temperature sensitive rod 21 penetrates the third flow passage 9 at a right angle, and the temperature of the refrigerant flowing in the third flow passage 9 is passed through the dish portion 22 to the diaphragm 17. The heat-sensitive chamber 1 is transmitted to the heat-sensitive chamber 10 on the upper side.
The thermal expansion and contraction of the saturated vapor gas at 0 are transmitted to the valve body 27 via the diaphragm 17, the temperature sensitive rod 21, and the operating rod 24.

Further, the dish portion 22 at the upper portion of the temperature sensitive rod 21 has an inner wall of the cylindrical screw portion of the lower lid 18 and the second flow path 8.
And a slide hole 32 formed between the third flow path 9 and the third flow path 9 are slidably held.

[0009]

However, the conventional expansion valve having such a structure has the following problems. (1) Since the valve body 6 of the conventional expansion valve 4 is made of a metallic material, it has good thermal conductivity. Therefore, the temperature around the expansion valve 4 is easily transmitted to the gaseous refrigerant in the pressure equalizing chamber 11 via the valve body 6. Normally, the expansion valve is arranged in the engine room of an automobile, but the temperature in the engine room becomes high due to the heat generation of the engine. Therefore,
When the temperature of the refrigerant in the pressure equalizing chamber 11 is transferred to the saturated gas in the heat sensitive chamber 10 via the temperature sensitive rod 21 or the like, the heat sensitive chamber 10
The temperature of the saturated gas inside becomes higher than the temperature of the refrigerant flowing through the third flow path 44. As a result, the opening amount of the orifice 25 by the valve body 27 is not accurately controlled, and the flow rate of the refrigerant introduced into the evaporator 5 cannot be adjusted accurately. In addition, the valve body 27 is frequently opened and closed, and the temperature of the air sent from the evaporator 5 into the vehicle compartment frequently changes in a short time.

(2) The high-temperature and high-pressure liquid refrigerant introduced into the first flow path 7 becomes a low-temperature and low-pressure atomized refrigerant as it passes through the orifice 25, and becomes the second flow path. Introduced in 8. However, since the metal valve body 6 has a good thermal conductivity, heat conduction between the high temperature liquid refrigerant in the first flow path 7 and the low temperature atomized refrigerant in the second flow path 8 is prevented. I can't block it enough. As a result, heat energy is lost, and the cooling efficiency of the air conditioner decreases.

(3) The metal valve body 6 is heavy. The expansion valve 4 is often supported by pipes connected to the first to third flow paths 7 to 9, but when the expansion valve 4 is heavy, a large load is applied to the pipes due to vibration, and the pipes are damaged. Not only is it more likely, but the processing costs are much higher. For this reason, it is desirable to mold the valve body 6 with a synthetic resin. However, since the synthetic resin has a lower strength than metal, when the operation in which the valve body 27 abuts on the synthetic resin valve seat 26 is repeated, Seat 26 may be damaged. When the valve body 6 is made of metal, the valve seat 26 is usually formed by pressing a steel ball having the same size as the valve body 27 around the entrance of the orifice 25. Thus, the valve seat 26
In the case of molding, when the valve body 27 comes into contact with the valve seat 26, no gap is formed between the two. However, when the valve body 6 is formed of synthetic resin, the valve seat 26 cannot be formed by the above-described method, so when the valve body 27 comes into contact with the valve seat 26, a gap occurs between the two. The refrigerant cannot be shut off reliably.

(4) The control mechanism 14 is mounted on the valve body 6 by screwing the male screw 18b formed on the mounting cylinder 18a of the lower lid 18 onto the female screw formed on the inner peripheral surface of the pressure equalizing chamber 11. Has been. Although the lower lid 18 can be formed at a low cost by press working, the male screw 18b of the mounting cylinder 18a needs to be formed by cutting, which increases the cost required for the cutting. In addition, it is necessary to use an adhesive in order to prevent the male screw 18b of the mounting cylinder 18a from loosening, which makes the mounting work of the control mechanism 14 troublesome.

(5) The lower end of the temperature sensitive rod 21 was supported by the sliding hole 32 formed in the valve body 6, but the upper end of the temperature sensitive rod 21 was screwed to the valve body 6. The lower cover 18 is supported by the inner peripheral surface of the mounting cylinder 18a. In other words, the lower end of the temperature sensitive rod 21 is directly supported by the valve body 6, while the upper end of the temperature sensitive rod 21 is indirectly supported by the valve body 6 via the mounting cylinder 18a. .
It is difficult to accurately position the sliding hole 32 formed directly in the valve body 6 and the mounting cylinder 18a screwed to the valve body 6 on the concentric axis. Therefore, the movement of the temperature sensitive rod 21 is not smooth, and the operation of the valve body 27 is hindered.
The temperature sensitive rod 21 is formed by cutting a cylindrical metal material, for example. However, the temperature-sensitive rod 21 integrally has the dish portion 22 at the upper end thereof, and the outer diameter thereof is largely different. Therefore, when cutting a portion of the temperature-sensitive rod 21 having a small outer diameter, the amount of material cut becomes very large, and the material is wasted.

(6) The pipe 33 used when the saturated greenhouse gas in the greenhouse 10 of the control mechanism 14 is filled with the pipe 33 projects largely above the upper lid 16. Therefore, when the expansion valve is attached to the circuit of the refrigeration cycle, the pipe 33
Is deformed by hitting a component in the engine room, and in the worst case, the pipe 33 is damaged and saturated vapor gas in the heat-sensitive chamber 10 leaks. In order to prevent this, it is necessary to secure a large space for disposing the expansion valve 4 in the engine room. When the saturated vapor gas is sealed in the heat-sensitive chamber 10, the pipe 33 brazed to the upper lid 16 is washed and then filled with the saturated vapor gas, and then the end portion of the pipe 33 is crushed to temporarily maintain airtightness. In addition, it is necessary to perform soldering work for sealing. Such encapsulation work is difficult to automate and the manufacturing cost is very high.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to minimize the influence of the ambient temperature on the temperature sensitive rod 65 of the expansion valve and to control the opening degree of the expansion orifice more accurately depending on the temperature of the low pressure refrigerant. By molding the valve body 41 with resin so that the temperature can be increased, it is possible to accurately control the opening amount of the orifice by the valve body and to provide a lightweight thermal expansion valve.

Further, according to the present invention, since the orifice portion 47a of the throttle mechanism 46 is formed by insert molding of the metal member 47, the valve seat 50 is not damaged and when the valve body comes into contact with the valve seat. Further, the present invention provides a thermal expansion valve in which no gap is generated between the two.

Further, according to the present invention, the metal collar 71 is attached to the pipe component mounting hole 70 of the expansion valve, so that when the expansion valve main body 41 is attached to the pipe mounting flange, the resin expansion valve 40 has a high temperature. The present invention provides a thermal expansion valve that is prevented from being permanently deformed by heat when exposed to the atmosphere.

The present invention also provides a thermal expansion valve which can be easily and surely mounted by fixing the control mechanism 54 to the valve body 41 by caulking.

Further, according to the present invention, the temperature sensitive rod 65 is supported by two-point support by a first sliding hole 63 and a second sliding hole 64 provided above and below the third flow path 44. By holding it as much as possible, the temperature type expansion valve is provided in which the movement of the temperature sensitive rod 65 can be performed smoothly.

Further, according to the present invention, the hole 5 formed in the upper lid 55
5a and the like, the gas is sealed in the heat sensitive chamber 61, and the steel ball 62
By sealing with the spot welding, saturated vapor gas can be easily and surely enclosed in the heat-sensitive chamber 61,
Moreover, it provides a compact thermal expansion valve.

That is, the first aspect of the present invention is the valve body 41.
And a throttle mechanism 46 for adjusting the flow rate of the refrigerant sent to the evaporator 5, and a control mechanism 54 for controlling the throttle mechanism 46 according to the temperature of the refrigerant sent from the evaporator 5 toward the compressor 1. The valve body 41 includes a first flow path 42 for introducing the refrigerant, a second flow path 43 for sending the introduced refrigerant to the evaporator, and the evaporator 1 to the compressor 1
And a third flow path 44 for passing the refrigerant sent toward the first flow path 4.
Orifice 47a which connects 2 and the 2nd flow path 43
And a valve body 48 for adjusting the opening amount of the orifice 47a. The control mechanism 54 includes a heat-sensitive chamber 61 in which a gas is sealed and a diaphragm 57 that is displaced according to the pressure in the heat-sensitive chamber 61. In a thermal expansion valve having a transmission member for transmitting the temperature of the refrigerant flowing through the third flow passage 44 to the gas in the heat-sensitive chamber 61 and transmitting the displacement of the diaphragm 57 to the valve body 48. , The valve body 41 is made of resin, and the orifice 47a of the throttle mechanism 46 is formed.
Is formed by insert molding of a metal member 47.

A second aspect of the present invention is the thermal expansion valve according to the first aspect, wherein a flange 41a is formed at the upper end of the valve body 41 as a connecting means between the valve body 41 and the control mechanism 54. The temperature type expansion valve is characterized in that a control mechanism 54 is arranged on the upper surface of the flange 41a, and the flange 41a and the control mechanism 54 are integrally fixed by caulking a tubular stopper 60.

A third aspect of the present invention is characterized in that, in the temperature type expansion valve according to the first aspect, a metal collar 71 is arranged in a mounting hole portion 70 of the valve body 41 to the pipe mounting flange. It is a thermal expansion valve.

A fourth aspect of the present invention is a temperature-sensing rod 65 for transmitting displacement of a diaphragm 57 of a control mechanism 54 to a throttle mechanism 46 in the temperature type expansion valve according to the first, second and third aspects. Is held by two-point support of a first sliding hole 63 and a second sliding hole 64 provided above and below the third flow path 44, respectively.

The fifth aspect of the present invention is defined by claim 1 or 2.
In the thermal expansion valve described, the heat-sensitive chamber 6 of the control mechanism 54.
As a means for sealing the saturated vapor gas into 1, the gas is sealed from the hole 55a formed in the upper lid 55 into the heat-sensitive chamber 61, and then the hole 55a is closed by a steel ball 62 and sealed by spot welding. It is a characteristic thermal expansion valve.

A sixth aspect of the present invention is characterized in that in the thermal expansion valve according to claim 1, claim 2, claim 3 or claim 4, the resin of the valve body 41 is a polyphenylene sulfide resin. Is a temperature type expansion valve.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The same parts as those of the conventional expansion valve are not described in detail, and are denoted by the same reference numerals. FIG. 1 is a vertical cross-sectional right side view showing a state in which the thermal expansion valve 40 of the present invention is incorporated in a refrigeration cycle of an automobile air conditioner, and FIG. 2 is a front view of FIG. The thermal expansion valve 40 includes a valve body 41 made of resin and a valve body 4
The drawing mechanism 46 and the control mechanism 54 are integrally formed with each other. The resin of the valve body 41 is preferably a polyphenylene sulfide resin having excellent resistance to refrigerant and refrigerating machine oil, resistance to crush pressure, resistance to creep, and heat resistance.

The resin valve main body 41 has a first flow path 42 communicating with the outlet of the condenser 2 via the receiver 3, a second flow path 43 communicating with the outlet of the evaporator 5, and an evaporator. A third flow path 44 that connects the outlet of the container 5 and the inlet of the compressor 1 is formed. A valve chamber 45 is formed in the center of the valve body 41 at the inner part of the first flow path 42. In addition,
The valve chamber 45 is exactly the same as the conventional product.

The throttling mechanism 46 is for adiabatically expanding the refrigerant, and is provided with a metal member 47 having an orifice, a valve body 48 and a compression coil spring 49. And
The metal member 47 is made of aluminum and is disposed between the first flow path 42 and the second flow path 43 so that the valve body 4 can be positioned between the first flow path 42 and the second flow path 43.
1 is fixed by insert molding. A valve seat 50 is formed on the valve chamber 45 side of the orifice.

The adjusting screw 51 which also serves as a cap is screwed to the lower end of the valve body 41, and the compression coil spring 49 is attached to the upper surface of the adjusting screw 51 in the valve chamber 45. The spherical valve body 48 is attached to the upper end of a compression coil spring 49 via a spring seat 52, and the compression coil spring 49
Is urged toward the valve seat 50. Further, the spherical valve element 48 is configured to open and close the orifice 47a by contacting and separating from the valve seat 50 on the lower surface of the orifice 47a. An O-ring 53 is provided on the adjusting screw 51 to keep the valve chamber 45 airtight.

The control mechanism 54 is mounted on the upper portion of the valve body 41, and the control mechanism 54 includes an upper lid 55 as a first cover and a lower lid 56 as a second cover.
It has a diaphragm 57 made of a stainless steel thin plate sandwiched between both lids 55 and 56. The upper lid 55 and the lower lid 56, with the diaphragm 57 sandwiched between them,
They are fixed integrally by welding their outer peripheral portions.

A pressure equalizing chamber 58 is provided at the center of the upper end of the valve body 41.
Is formed by opening, and a flange 41a is formed on the outer peripheral portion of the upper end of the valve body 41. And this flange 4
The lower lid 56 of the control mechanism 54 is caulked on the upper portion 1a so as to cover the flange 41a of the stack valve main body 41 and the outer peripheral portion of the control mechanism 54 via the packing 59 so as to cover the upper and lower portions. Both are fixed by this. In this embodiment, the caulking is performed by the cylindrical stopper 60, but as shown by the chain double-dashed line in FIG. 1, the stopper 60 pressed into a dome shape is used to cover the upper lid 55. May be covered from above.

Further, in the valve body 41, as shown in FIG. 2, a metal collar 71 is provided in the piping part mounting hole 70 of the expansion valve.
When the expansion valve main body 41 is attached to a pipe mounting flange (not shown), the resin expansion valve 40 is exposed to a high temperature atmosphere so that permanent set due to heat does not occur.

In the control mechanism 54, a heat sensitive chamber 61 is formed between the upper lid 55 and the diaphragm 57, and a saturated vapor gas such as HFC-134a is exposed in the central portion of the upper lid 55 in the heat sensitive chamber 61. It is sealed from the hole 55a, and the steel ball 62 is integrally fixed to the hole 55a by spot welding so as to be hermetically shielded from the outside.

The saturated vapor gas sealing method is generally sealed by spot welding in a chamber filled with the saturated vapor gas. A pressure equalizing chamber 58 is formed in the upper end portion of the valve body 41, and has a third flow passage 44 in the lower portion thereof. One sliding hole 63 is formed, and even when the shaft portion 66 of the temperature sensing rod 65 is inserted into the first sliding hole 63, as shown in FIG.
8 communicates so that the refrigerant is introduced.

A second sliding hole 64 is formed in the lower center portion of the third flow path 44, and the second sliding hole 64 is formed.
A hole 68 for the operating rod 69 is formed on the concentric shaft between the lower end of the second flow path 43 and the lower end of the second flow path 43.

The temperature sensitive rod 65 includes a shaft portion 66 and a dish 67.
The first sliding hole 63 and the second sliding hole 64 are inserted through and supported by the first sliding hole 63 so as to be vertically movable. The dish portion 67 of the temperature sensitive rod 65 is disposed in the pressure equalizing chamber 58 and the diaphragm 57.
Abuts the underside of.

Further, the third channel 44 and the second channel 43
The inner portion of the temperature sensitive rod 65 is hermetically held by an O-ring attached to the lower end portion of the temperature sensitive rod 65. The actuating rod 69 is vertically movably mounted inside the hole 68 for the actuating rod 69, the upper end of the actuating rod 69 abuts on the lower end surface of the temperature sensitive rod 65, and the intermediate portion thereof has the second portion. It is inserted into the orifice 47a across the inner part of the flow path 43, and its lower end is in contact with the valve body 48.

[0039]

Next, the operation of this embodiment in the above configuration will be described with reference to FIG. The high-temperature high-pressure gaseous refrigerant adiabatically compressed by the compressor 1 of the refrigeration cycle is condensed by the condenser 2 into a liquid refrigerant, and then flows through the first flow path 42 of the expansion valve 40 via the receiver 3. It is introduced into the passage valve chamber 45. Further, this liquid refrigerant passes through the orifice 47a,
At this time, it is adiabatically expanded into a low-temperature atomized refrigerant and introduced into the second flow path 43. Then, this refrigerant flows through the second flow path 43.
Then, it is introduced into the evaporator 5 and vaporized to become a gaseous refrigerant. Further, the gaseous refrigerant discharged from the evaporator 5 returns to the compressor 1 again through the third flow path 44.

On the other hand, the temperature sensitive rod 65 is a compression coil spring 49.
Thus, it is constantly urged upward through the spring seat 52, the valve element 48, and the operating rod 69. Therefore, orifice 4
The position of the valve body 48 with respect to the valve seat 50 that determines the opening of the valve 7a is maintained at a position where the urging force of the compression coil spring 49, the refrigerant pressure in the pressure equalizing chamber 58, and the gas pressure in the heat sensitive chamber 61 are balanced. Dripping. The pressure of the refrigerant in the pressure equalizing chamber 58 is controlled by the evaporator 5.
Is the gas pressure evaporated.

Then, the gaseous refrigerant passing through the third flow path 43 enters the pressure equalizing chamber 58 through the groove 63a of the first sliding hole 63, as shown in FIGS. Thus, the heat of the refrigerant is transferred from the shaft portion 66 of the temperature sensing rod 65 to the dish 6.
The heat is transmitted to the saturated steam gas in the heat-sensitive chamber 61 through the diaphragm 57. That is, the pressure in the heat-sensitive chamber 61 changes according to the temperature of the refrigerant at the outlet side of the evaporator 5.
The vertical movement of the diaphragm 57 due to the pressure change in the heat-sensitive chamber 61 is transmitted to the valve body 48 via the temperature-sensing rod 65 and the operating rod 69, and the valve body 48 is controlled to open and close to superheat the refrigerant at the outlet of the evaporator 5. Is superheat controlled so that is constant.

[0042]

In the expansion valve of the present invention constructed as described above, the valve body 41 is made of polyphenylene sulfide resin and has a thermal conductivity higher than that of the conventional valve body 6 made of metal such as aluminum. It is about 1/150.
Therefore, the high temperature around the expansion valve 40 is difficult to be transmitted to the gaseous refrigerant in the pressure chamber 58, and the temperature of the refrigerant in the pressure equalizing chamber 58 becomes almost the same as the temperature of the refrigerant flowing in the third flow path 44. . Therefore, when the temperature of the refrigerant in the pressure equalizing chamber 58 is transferred to the saturated vapor gas in the heat sensitive chamber 61 via the temperature sensitive rod 65 or the like, the temperature of the saturated vapor gas in the heat sensitive chamber 61 becomes the third value. The temperature of the refrigerant flowing through the flow path 44 becomes almost the same. That is, the temperature of the coolant flowing through the third flow path 44 is
Accurately transferred to the saturated vapor gas inside. As a result, the opening amount of the orifice 47a by the valve body 48 is accurately controlled, and the flow rate of the refrigerant introduced into the evaporator 5 is accurately adjusted.

FIG. 4 shows the condenser 2 when the expansion valve 40 of this embodiment is used in an environment where the ambient temperature T1 is about 75 °.
2 is a graph showing changes in the pressure P1 at the outlet of the vehicle, the pressure P2 at the inlet of the evaporator 5, the pressure P3 at the outlet of the evaporator 5 and the temperature T2 of the air sent from the evaporator 5 into the vehicle compartment. . In addition, FIG. 5 shows that the conventional expansion valve 4 has an ambient temperature T1.
When used in an environment of about 75 °, the pressure P1 at the outlet of the condenser 2, the pressure P2 at the inlet of the evaporator 5, the pressure P3 at the outlet of the evaporator 5 and the inside of the vehicle from the evaporator 5 6 is a graph showing the state of changes in the temperature T2 of the air sent.

As is apparent from FIG. 5, the conventional expansion valve 4
When used in a high temperature environment of approximately 75 °,
The pressure P1 at the outlet of the condenser 2, the pressure P2 at the inlet of the evaporator 5, the pressure P3 at the outlet of the evaporator 5, and the temperature T2 of the air sent from the evaporator 5 into the passenger compartment frequently fluctuate. This indicates that the temperature of the saturated vapor gas in the heat sensitive chamber 10 becomes higher than the temperature of the refrigerant flowing through the third flow passage 9, so that the valve body 48 is frequently opened and closed.

On the other hand, as shown in FIG. 4, when the expansion valve 40 of the present embodiment is used, even if the ambient temperature T1 is in the high temperature environment of about 75.degree.
And the temperature T2 of the air sent into the passenger compartment is stabilized.

Further, since the valve body 41 is made of resin, its weight is about 1/2 that of the conventional metal body made of aluminum. Therefore, the first to third flow paths 42 to 4
There is no risk that the pipe connected to 4 will be damaged by vibration.
In addition, the processing cost is very low. Further, since the orifice 47a is formed by insert molding of the metal member 47, there is no risk of the orifice 47a being damaged by the opening / closing operation of the valve body 48, and the valve seat 50 is formed by molding the valve seat in the same manner as a conventional metal seat. Therefore, there is no problem such as refrigerant leakage when the orifice is fully closed.

Further, by adopting the caulking method using the tubular stopper 60 for connecting the valve main body 41 and the control mechanism 54, screw processing is not required and the cost can be reduced very much. Is unnecessary, and it becomes possible to make a reliable and permanent connection.

Further, the temperature sensing rod 65 has a first sliding hole 63 penetrating the pressure equalizing chamber 58 in the upper part of the valve body 41 and the third flow passage 44 in the orthogonal direction, and the third flow passage 44. Since the first sliding hole 63 and the second sliding hole 64 formed on the same axis as the first sliding hole 63 are slidably held in the lower portion, the temperature sensitive rod 6
In addition to smoothing the movement of 5, the upper portion of the temperature-sensitive rod 65 itself and the shaft portion 66 of the temperature-sensitive rod 65 can be formed separately by caulking, so that the material yield can be improved. Will get better. Further, the dish portion 67 and the temperature sensitive rod 65 can be formed of different metal materials. By doing so, it becomes possible to finely adjust the thermoelectric state by the temperature sensitive rod 65. In this case, it is preferable that the temperature sensitive rod 65 is made of stainless steel and the dish portion 67 is made of aluminum or brass.

Regarding the method of sealing the saturated vapor gas in the heat-sensitive chamber 61, the hole 5 formed in the upper lid 55 of the control mechanism 46 is used.
5a is filled with gas from the heat-sensitive chamber 61 and the steel ball 6
By closing the hole 55a at 2 and sealing it by spot welding or the like, it becomes very compact. Further, when the hole 55a of the upper lid 55 is sealed, since the steel ball 62 is used, there is no direction regulation at the time of assembling, which facilitates automation.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a state in which an expansion valve of the present invention is incorporated in a refrigeration cycle of an automotive air conditioner.

FIG. 2 is a front view of FIG. 1;

FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 shows changes in pressure at the outlet of the condenser, pressure at the inlet of the evaporator, pressure at the outlet of the evaporator, and temperature of air sent from the evaporator into the passenger compartment when the expansion valve of the present embodiment is used. Graphs showing the respective states.

FIG. 5 shows the state of changes in the pressure at the condenser outlet, the pressure at the evaporator inlet, the pressure at the evaporator outlet, and the temperature of the air sent from the evaporator to the passenger compartment when a conventional expansion valve is used. Graph showing each.

FIG. 6 is a vertical sectional side view showing a state in which a conventional expansion valve is incorporated in a refrigeration cycle of an automobile air conditioner.

[Explanation of symbols]

1 compressor 2 condenser, 3
Receiver, 40 expansion valve, 5 evaporator,
41 valve body, 41a flange,
42 first flow path, 43 second flow path, 44 third flow path, 45 valve chamber, 46 throttle mechanism, 47 metal member, 47a orifice,
48 valve body, 49 compression coil spring, 50 valve seat, 51 adjusting screw, 52 spring seat,
53 O-ring, 54 control mechanism, 55
Top lid, 55a hole, 56
Lower lid, 57 diaphragm, 58 pressure equalizing chamber,
59 packing, 60 stopper, 61
Heat sensitive chamber, 62 steel ball, 63 first sliding hole,
64 second sliding hole, 65 temperature sensitive rod, 66 shaft part, 67 dish part, 68 hole,
69 actuating rod, 70 mounting hole, 7
1 color.

Claims (6)

[Claims] A throttle mechanism for adjusting a flow rate of the refrigerant sent to the evaporator; and a throttle mechanism in accordance with the temperature of the refrigerant sent from the evaporator toward the compressor. The valve body 41 includes a first flow path 42 for introducing the refrigerant, and a second flow path 43 for sending out the introduced refrigerant to the evaporator.
And a third flow path 44 for allowing the refrigerant sent from the evaporator 5 toward the compressor 1 to pass therethrough. The throttle mechanism 46 includes a first flow path 42 and a second flow path 43. And a valve element 48 for adjusting the opening amount of the orifice 47a. The control mechanism 54 includes a thermosensitive chamber 61 filled with gas, and a thermosensitive chamber 61.
Having a diaphragm 57 that is displaced in accordance with the internal pressure,
The temperature of the refrigerant flowing through the third flow path 44 is transmitted to the gas in the heat-sensitive chamber 61, and the displacement of the diaphragm 57 is transmitted to the valve body 4.
In the thermal expansion valve having a transmission member for transmitting to the No. 8, the valve body 41 is molded with resin, and the orifice 47a of the throttle mechanism 46 is formed by insert molding of the metal member 47. valve. 2. A flange 41a is formed at the upper end of the valve body 41 as a connecting means between the valve body 41 and the control mechanism 54,
2. The thermal expansion according to claim 1, wherein a control mechanism 54 is arranged on the upper surface of the flange 41a, and the flange 41a and the control mechanism 54 are integrally fixed by caulking a tubular stopper 60. valve. 3. The thermal expansion valve according to claim 1, wherein a metal collar 71 is arranged in a mounting hole portion 70 of the valve body 41 to the pipe mounting flange. 4. A temperature sensitive rod 65 for transmitting the displacement of the diaphragm 57 of the control mechanism 54 to the diaphragm mechanism 46, and a first sliding hole 63 and a second sliding hole provided above and below the third flow path 44. Hole 64
The temperature expansion valve according to claim 1, 2 or 3, wherein the temperature expansion valve is held by the two-point support. 5. As a means for sealing the saturated vapor gas in the heat-sensitive chamber 61 of the control mechanism 54, after sealing the gas into the heat-sensitive chamber 61 from a hole 55a formed in the upper lid 55, the hole 55a is filled with the steel ball 6.
2. The temperature type expansion valve according to claim 1, wherein the temperature type expansion valve is closed at 2 and sealed by spot welding. 6. The temperature type expansion valve according to claim 1, wherein the resin of the valve body 41 is a polyphenylene sulfide resin.