JPH10318629A - Thermal expansion valve manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method which can manufacture thermal expansion valves at a low cost by eliminating an aperture formed on an upper lid and a steel ball for closing this aperture after filling gas into a temperature sensing chamber which were necessary in a thermal expansion valve manufactured by the conventional method. SOLUTION: In a thermal expansion valve manufacturing method, especially in a process of the method for filling saturated vapor gas, a diaphragm 57, a lower lid 56 and a temperature sensing bar 65 which constitute a part of control mechanism 54 in a chamber are supported by a suitable jig. After replacing air in the chamber with saturated vapor gas, an upper lid 55 is placed on the upper surface of the diaphragm 57 in the chamber and has its outer peripheral portion hermetically assembled by a laser welding in an atmosphere of saturated vapor gas thus filling the saturated vapor gas in a temperature sensing chamber 61.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a temperature-type expansion valve used in a refrigeration cycle of an air conditioner, and particularly, to weld an outer peripheral portion of a control mechanism in a chamber filled with saturated steam gas. Accordingly, the present invention relates to a method for manufacturing a temperature-type expansion valve, which is capable of filling saturated steam gas into a heat-sensitive chamber simultaneously with welding.

[0002]

2. Description of the Related Art Conventionally, the amount of refrigerant entering an evaporator is automatically controlled in response to the temperature of the refrigerant sent from an evaporator of a refrigeration cycle of an automobile air conditioner to a compressor. Various thermal expansion valves have been proposed. FIG. 2 is a longitudinal sectional view showing a state in which a conventional thermal expansion valve 4 is incorporated in a refrigeration cycle of an automotive air conditioner. The automotive air conditioner includes a compressor 1, a condenser 2, and a receiver 3. , An expansion valve 4 and an evaporator 5.

[0003] The expansion valve 4 is provided inside a resin valve body 41.
A first flow path 42 communicating with the outlet of the condenser 2, a second flow path 43 communicating with the inlet of the evaporator, and a third flow path communicating the outlet of the evaporator 5 with the inlet side of the compressor 1. And a flow path 44. The throttle mechanism 46 is disposed at the back of the first flow path 42, and has an orifice 47 a, a valve element 48, and a compression coil spring 49. The orifice 47a is provided with a valve body 41 for communicating the first flow path and the second flow path.
And has an inlet opening into the valve chamber 45,
A valve seat 50 is formed around the inlet. The valve element 48 is urged toward a valve seat 50 by a compression coil spring 49. The valve element 48 abuts on the valve seat 50 to close the orifice 47a, and separates from the valve seat 50. The orifice 47a is opened.

The right side of the third flow path 44 is connected to the compressor 1, and the compressor 1 is connected to the first flow path 42 via the condenser 2 and the receiver 3. . The left side of the third flow path 44 is connected to the evaporator 5, and the evaporator 5 is connected to the second flow path 43.

On the other hand, a flange portion 41a at the top of the valve body 41
The upper lid 55, the lower lid 56, the upper lid 55 and the lower lid 56
And a diaphragm 57 made of a stainless steel thin plate sandwiched therebetween, and a control mechanism 54 is hermetically fixed by a stopper 60 through a packing 59.

A heat-sensitive chamber 61 formed by the upper lid 55 and the diaphragm 57 is filled with a saturated steam gas and sealed with a steel ball 62.

The above-described process of filling the saturated vapor gas will be described in detail. The upper lid 55, the diaphragm 57, the lower lid 56 and the temperature sensing rod 65, which constitute the control mechanism 54 in advance, are set in an appropriate jig, and the outer periphery thereof is set. Welded by laser welding etc.
Next, the control mechanism 54 is placed in a sealed chamber.
Is supported by an appropriate jig, and air in the chamber is
After replacement with the saturated steam gas through the hole 70 formed in 5, a steel ball 62 is applied to the hole 70 of the upper lid 55 in the chamber and sealed by spot welding or the like so that the saturated steam gas is sealed in the heat-sensitive chamber 61. I was

The temperature sensing rod 65 has a central portion penetrating through the third flow path 44 in a direction perpendicular to the third flow path 44, and the temperature of the refrigerant flowing through the third flow path 44 is changed via the dish 67 to the upper part of the diaphragm 57. To the heat-sensitive chamber 61 and the heat-sensitive chamber 6
1, the thermal expansion or thermal contraction of the saturated steam gas is transmitted to the valve element 48 via the diaphragm 57, the temperature sensing rod 65, and the operating rod 69.

[0009]

However, in the conventional method of sealing a saturated steam gas in the expansion valve having the above-described structure, a hole 70 is formed in the upper lid to replace the saturated steam gas with the atmosphere. After the gas was sealed from the hole into the temperature sensing chamber, a steel ball was applied to the hole 70 to seal the temperature sensing chamber by spot welding, so that in order to ensure airtightness after welding, it was formed on the upper lid. There has been a problem that a high degree of coaxiality and a high degree of roundness accuracy are required in the processing of the hole, and the processing cost of the upper lid increases. In addition, since it is necessary to weld the steel ball and the top lid uniformly around the entire circumference in order to maintain airtightness, high positioning accuracy is required, and there is a problem that an expensive spot welding machine must be used. .

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control system for an expansion valve which seals a saturated steam gas with an outer peripheral portion of the control mechanism in a chamber filled with the saturated steam gas. By welding, saturated steam gas can be sealed in the heat-sensitive chamber at the same time as welding, and the high-precision coaxiality and roundness precision required for the top lid, which was required for the temperature type expansion valve by the conventional manufacturing method The steel ball for closing the hole after filling the gas into the temperature-sensitive chamber and the hole formed in the above can be eliminated, and without using an expensive spot welding machine requiring high positioning accuracy, low-cost temperature It is an object of the present invention to provide a manufacturing method which can obtain an expansion valve and can also improve the airtight reliability by reducing the number of welding points.

That is, the method of manufacturing a thermal expansion valve according to the present invention comprises a valve body 41 made of resin, a throttle mechanism 46 for adjusting a flow rate of a refrigerant sent to the evaporator 5, and a compressor 1 from the evaporator 5. And a control mechanism 54 for controlling the throttle mechanism 46 in accordance with the temperature of the refrigerant sent out toward the expansion chamber, wherein a part of the control mechanism 54 is formed in the chamber. After supporting the diaphragm 57, the lower lid 56 and the temperature sensing rod 65 with an appropriate jig, and replacing the air in the chamber with a saturated steam gas, the upper lid 55 is placed on the upper surface of the diaphragm 57 in the chamber. And sealing the outer peripheral portion of the valve body 41 in an airtight atmosphere by laser welding or the like in an atmosphere of a saturated steam gas and enclosing the saturated steam gas in the heat-sensitive chamber 61. Fitting, a step of integrally fixed by fitting 60 stop both Thereafter, the resin valve body 41, an orifice 47
a) assembling the throttle mechanism 46 provided with a valve element 48 for adjusting the opening amount of “a”.

[0012]

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 longitudinal sectional view showing a state in which the thermal expansion valve 4 of the present invention is incorporated in a refrigeration cycle of an automotive air conditioner.

The thermal expansion valve 4 of the present invention comprises a resin valve body 41, a throttle mechanism 46 and a control mechanism 54 integrally formed with the valve body 41, as in the case of the conventional product. The control mechanism 54 includes an upper lid 55 as a first cover, a lower lid 56 as a second cover,
And a diaphragm 57 made of a stainless steel plate sandwiched between the valve body 5 and the valve body 56.
It is the same as the conventional product in that it is airtightly fixed to the upper flange portion 41a by the cylindrical stopper 60 via the packing 59 via the packing 59.

An upper lid 55, which is a component of the control mechanism 54,
In the configuration described above, the conventional product uses the steel ball 62 for providing the hole 70 for gas filling and closing the hole 70. However, in the present invention, neither the hole 70 nor the steel ball 62 is required. ing.

Next, a method for manufacturing the thermal expansion valve of the present invention will be described in detail with reference to the assembly process diagram of FIG. First, the temperature sensing rod 65 is placed on the lower surface of the diaphragm 57 in advance.
Is fixed by caulking, and the control mechanism 54 is fixed by an appropriate jig in a sealable chamber.
After supporting the metal diaphragm 57, the lower lid 56, and the temperature sensing rod 65 which constitute a part of the chamber, the chamber is sealed, and the air in the chamber is replaced with saturated steam gas.
The upper cover 55 is placed on the upper surface of the diaphragm 57 by an appropriate transfer means provided in the chamber, and the upper cover 5
In a state where the diaphragm 57 is sandwiched between the lower cover 5 and the lower cover 56, the outer peripheral portion is welded by laser welding or the like in an atmosphere of a saturated steam gas to fill the heat-sensitive chamber 61 with the saturated steam gas. Next, the temperature sensing rod 66 is fitted into the first sliding hole 63 of the valve body 41 in the atmosphere, and the valve body 41 and the control mechanism 54 are caulked and integrally fixed with the stopper 60 (as compared with the conventional process). the same). After that, the valve body 4 is provided on the resin valve body 41 as a throttle mechanism 46 for adjusting the opening amount of the orifice 47a.
8. Assemble the spring seat 52 and the compression coil spring 49 (the same as the conventional process). Thus, the temperature type expansion valve can be assembled through the steps (1) to (4).

[0016]

As described above, the method for manufacturing an expansion valve according to the present invention involves welding the outer periphery of the control mechanism in a chamber filled with saturated steam gas. Saturated steam gas can be sealed in the chamber, and a hole formed in the top lid with a high degree of coaxiality and roundness precision, which is required for the temperature type expansion valve by the conventional manufacturing method, and gas to the temperature sensitive chamber The steel ball for closing this hole after sealing can be eliminated, eliminating the need for an expensive spot welder that requires high positioning accuracy, and improving the airtight reliability by reducing the number of welding points. An inexpensive temperature-type expansion valve can be provided.

[Brief description of the 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 vertical sectional side view showing a state where a conventional expansion valve is incorporated in a refrigeration cycle of an automotive air conditioner.

FIG. 3 is an assembly process diagram of the thermal expansion valve of the present invention.

[Explanation of symbols]

1 compressor, 2 condenser, 3
Receiver, 4 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
Upper lid, 56 Lower lid, 57
Diaphragm, 58 Equalizing chamber, 59 Packing, 60 Stopper, 61 Thermal chamber,
62 steel ball, 63 first sliding hole, 63
a groove, 64 second sliding hole, 65
Temperature sensing rod, 66 shaft part, 67 dish part, 68 holes, 69 operating rod, 70
Hole.

Claims (1)

[Claims] 1. A resin valve body 41, a throttle mechanism 46 for adjusting the flow rate of refrigerant sent to the evaporator 5, and a throttle according to the temperature of the refrigerant sent from the evaporator 5 toward the compressor 1. A method for manufacturing a thermal expansion valve comprising a control mechanism 54 for controlling a mechanism 46, comprising: a diaphragm 57, a lower lid 56, and a temperature sensing rod 65 which constitute a part of the control mechanism 54 in a chamber. After the air in the chamber is replaced with a saturated steam gas, the upper lid 55 is placed on the upper surface of the diaphragm 57 in the chamber, and the upper lid 55 is placed in an atmosphere of the saturated steam gas. A process in which the outer peripheral portion is hermetically assembled by laser welding or the like and a saturated steam gas is sealed in the heat-sensitive chamber 61; a control mechanism 54 is fitted into the valve body 41 in the atmosphere; A step of, after the resin valve body 41, an orifice 47
assembling the throttle mechanism 46 provided with a valve element 48 for adjusting the opening amount of a. a.