JP3726015B2 - Expansion valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an expansion valve, and in particular, expands a high-temperature / high-pressure refrigerant into a low-temperature / low-pressure refrigerant in a vehicle air conditioner and controls the refrigerant flow rate so that the refrigerant at the evaporator outlet has a predetermined degree of superheat. The present invention relates to a temperature type expansion valve used in a refrigeration cycle using a variable capacity compressor having an external control valve.
[0002]
[Prior art]
In vehicle air conditioners, a compressor compresses refrigerant gas to high temperature and high pressure, cools it with a condenser, condenses it into liquid, and separates it with a receiver / dryer, then expands high temperature and high pressure liquid refrigerant. The refrigerant is decompressed and expanded by a valve to obtain a low-temperature and low-pressure refrigerant, which is evaporated by an evaporator and returned to the compressor.
[0003]
The expansion valve supplies high-temperature and high-pressure liquid refrigerant from the receiver / dryer to the evaporator through a valve that forms the orifice, and supplies it to the evaporator, as well as sensing the pressure and temperature of the refrigerant at the outlet of the evaporator. The flow rate of the refrigerant passing through the valve is controlled, and the refrigerant amount is controlled in accordance with the fluctuation of the cooling load and the fluctuation of the rotation speed of the compressor.
[0004]
FIG. 2 is a cross-sectional view showing a configuration example of a conventional expansion valve.
The expansion valve 1 includes a refrigerant pipe connection hole 3 that connects a refrigerant pipe to which a high-temperature / high-pressure refrigerant is supplied from a receiver / dryer, and a low-temperature Refrigerant line connection hole 4 for connecting a refrigerant pipe for supplying a low-pressure refrigerant to the evaporator, a refrigerant line connection hole 5 for connecting a refrigerant pipe from the evaporator outlet, and a refrigerant line connection for connecting a refrigerant pipe leading to the compressor And a hole 6.
[0005]
A valve seat 7 is formed integrally with the body 2 in the fluid passage between the refrigerant pipe connection hole 3 and the refrigerant pipe connection hole 4, and a ball-shaped valve body is formed upstream of the valve seat 7. 8 is arranged. A compression coil spring 9 that urges the valve body 8 to be seated on the valve seat 7 is disposed in the fluid passage communicating with the refrigerant pipe connection hole 3. The compression coil spring 9 is received by an adjustment screw 10 screwed to the lower end surface of the body 2. By changing the load of the compression coil spring 9 with the adjustment screw 10, the set value of the expansion valve 1 is changed. Adjustments are made.
[0006]
A power element is provided at the upper end of the body 2. The power element includes an upper housing 11, a lower housing 12, a diaphragm 13 that partitions a space surrounded by the upper housing 11, and a disk 14 disposed on the lower surface of the diaphragm 13. A shaft 15 that transmits the displacement of the diaphragm 13 to the valve body 8 is disposed below the disk 14. The upper portion of the shaft 15 is held by a holding member 16 disposed across a fluid passage communicating with the refrigerant pipe connection holes 5 and 6. Note that the lower chamber of the power element partitioned by the diaphragm 13 communicates with the fluid passage communicating with the refrigerant pipe connection holes 5 and 6 through a gap in the cross-sectional holding member head so as to equalize the pressure. Is doing.
[0007]
Here, the assembly of the part constituting the orifice of the expansion valve 1 is performed by incorporating the ball-shaped valve body 8 and the compression coil spring 9 in the fluid passage on the extension line of the shaft 15 and further tightening the adjustment screw 10. I was going.
[0008]
[Problems to be solved by the invention]
However, the valve body and the compression coil spring are assembled in a heavy state where the compression coil spring is mounted on the adjustment screw and the valve body is placed on the compression coil spring. As a result, the compression coil spring and the valve body on the adjustment screw may fall over or fall off, resulting in a problem that productivity is lowered.
[0009]
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 does not fall or drop when the valve body and the compression coil spring are assembled.
[0010]
[Means for Solving the Problems]
In the present invention, in order to solve the above problems, a valve constituting a variable orifice, a compression coil spring that urges the valve body of the valve in a valve closing direction, a load of the compression coil spring while receiving the compression coil spring. In a temperature type expansion valve having an adjustment screw for adjusting the pressure and a diaphragm for detecting the pressure and temperature of the refrigerant to control the valve, the adjustment screw is divided at the outer peripheral groove where the O-ring is mounted An expansion valve is provided, which is formed by molding by double molding and is provided with a convex portion at a portion for receiving the compression coil spring.
[0011]
According to such an expansion valve, when the valve body and the compression coil spring are incorporated into the body, the compression coil spring can be held on the convex portion of the adjustment screw, so that the compression coil spring does not wobble and the adjustment screw The assembly failure due to the compression coil spring and valve body mounted on the body falling over or falling off is eliminated. Thereby, the productivity of the expansion valve can be improved.
[0012]
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 cross-sectional view showing a configuration example of an expansion valve according to the present invention. In FIG. 1, the same elements as those of the conventional expansion valve are denoted by the same reference numerals.
[0013]
In this expansion valve 1, the refrigerant pipe connection hole 3 provided on the side of the body 2 is connected to a refrigerant pipe to which high-temperature and high-pressure refrigerant is supplied from the receiver / dryer, and the refrigerant pipe connection hole 4 is The refrigerant pipe connected to the refrigerant pipe for supplying the low-temperature and low-pressure refrigerant adiabatically expanded by the expansion valve 1 to the evaporator is connected to the refrigerant pipe from the evaporator outlet, and the refrigerant pipe connection hole 6 is connected to the refrigerant pipe leading to the compressor, and the arrow in the figure indicates the flow direction of the refrigerant.
[0014]
A valve seat 7 is formed integrally with the body 2 in a fluid passage communicating from the refrigerant pipe connection hole 3 to the refrigerant pipe connection hole 4. A ball-shaped valve body 8 is formed upstream of the valve seat 7. Has been placed. A compression coil spring 9 that urges the valve body 8 to be seated on the valve seat 7 is disposed in the fluid passage on the refrigerant pipe connection hole 3 side. The compression coil spring 9 is received by an adjustment screw 10. . The adjustment screw 10 is screwed to the lower end surface of the body 2 and is sealed from the body 2 by an O-ring 17.
[0015]
The adjustment screw 10 has a convex portion 18 at an upper center portion thereof, and a groove 19 for holding the compression coil spring 9 is formed at a base portion thereof. Thereby, when the valve body 8 and the compression coil spring 9 are assembled, the compression coil spring 9 can be supported from the inside and outside by the convex portion 18 and the groove 19, so that the compression coil spring 9 can be prevented from wobbling. Therefore, when the adjusting screw 10 is assembled in the body 2 with the valve body 8 placed on the compression coil spring 9, the compression coil spring 9 does not fall over or fall off even if an impact is received. As a result, it is possible to prevent defective assembly of the valve body 8 and the compression coil spring 9.
[0016]
The adjustment screw 10 is usually made of a molding material. However, in the case of the molding material, there is a possibility that a parting line due to the split mold may be generated and the refrigerant may leak from the parting line. The adjusting screw 10 is configured by molding by double molding divided as follows. That is, the adjustment screw 10 first forms a member having the convex portion 18 and the groove 19, and then forms a portion having a thread for screwing onto the body 2. Thereby, the adjustment screw 10 without a parting line can be configured. Of course, this adjustment screw 10 can also be comprised with a cutting material.
[0017]
Further, at the upper end of the body 2, there is a power element constituted by an upper housing 11, a lower housing 12, a diaphragm 13 that partitions a space surrounded by these, and a disk 14 disposed on the lower surface of the diaphragm 13. Is provided.
[0018]
A shaft 15 that transmits the displacement of the diaphragm 13 to the valve body 8 is disposed below the disk 14. The upper portion of the shaft 15 is held by a holding member 16 disposed across a fluid passage communicating with the refrigerant pipe connection holes 5 and 6.
[0019]
The upper end of the shaft 15 is in contact with the lower surface of the disk 14, but the contact surface is inclined with respect to a plane perpendicular to the axis of the shaft 15, and the movement of the diaphragm 13 in the axial direction is An axial load and a lateral load are applied to the shaft 15. As a result, when the movement of the diaphragm 13 is transmitted to the shaft 15, a lateral load component acts on the shaft 15 to suppress vibration in the longitudinal direction of the shaft 15.
[0020]
In the expansion valve 1 having the above configuration, the power element senses the pressure and temperature of the refrigerant returned from the evaporator to the refrigerant pipe connection hole 5, and if the temperature of the refrigerant is high, the sealed gas therein expands, The valve body 8 is pushed in the direction in which the valve opens, and if the temperature is low, the valve body 8 is moved in the direction in which the valve is closed. Moreover, when the pressure of a refrigerant | coolant becomes low, the valve body 8 is pushed in the direction which a valve opens, and conversely, when it becomes high, it controls to move the valve body 8 in the direction which a valve closes.
[0021]
【The invention's effect】
As described above, in the present invention, a convex portion that prevents the compression coil spring from overturning is formed in the portion of the adjustment screw that receives the compression coil spring. As a result, the compression coil spring can be held on the convex portion of the adjustment screw, and therefore, when the valve body and the compression coil spring are assembled into the body, the compression coil spring will not fluctuate. Even so, there is no assembly failure due to the compression coil spring and valve body mounted on the adjusting screw falling or falling off, and productivity can be improved. Further, not only at the time of production but also when disassembling and reassembling, it is possible to eliminate the problem of quality defects associated therewith.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration example of an expansion valve according to the present invention.
FIG. 2 is a cross-sectional view showing a configuration example of a conventional expansion valve.
[Explanation of symbols]
1 Expansion valve 2 Body 3, 4, 5, 6 Refrigerant pipe connection hole 7 Valve seat 8 Valve body 9 Compression coil spring 10 Adjustment screw 11 Upper housing 12 Lower housing 13 Diaphragm 14 Disc 15 Shaft 16 Holding member 17 O-ring 18 Convex Part 19 groove

Claims (1)

A valve constituting a variable orifice, a compression coil spring that urges the valve body of the valve in a valve closing direction, an adjustment screw that receives the compression coil spring and adjusts a load of the compression coil spring, a pressure of the refrigerant, and In a temperature type expansion valve provided with a diaphragm for detecting the temperature and controlling the valve,
2. The expansion valve according to claim 1, wherein the adjustment screw is formed by double-molding molding divided with an outer peripheral groove on which an O-ring is mounted as a boundary, and a convex portion is provided in a portion that receives the compression coil spring.

Images