JP3292796B2 - Relief valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relief valve used in a refrigeration cycle of a car air conditioner or the like, and more particularly to a screw formed in a metal body at a lower end portion of a male screw. By extending the relief valve to a position equal to or lower than the upper end position of the relief portion, an extremely small relief valve is provided.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional relief valve. The relief valve has a pressure inlet 2 having a smaller diameter than a lower portion inside a metal body 1 having an outer peripheral portion formed in a cylindrical shape. A convex ring-shaped valve seat 3 is formed on the inner peripheral edge of the inlet 2 and a large-diameter chamber 4 is formed above the valve seat 3.
On the other hand, a plate 1 to be described later is
There is provided a shoulder portion 5 for placing 0 thereon. A valve body 8 having an opening 6 in the center of the lower surface above the valve seat 3 in the chamber 4 and an outer peripheral portion formed by fitting an elastic packing 7 in the opening 6 is formed in a polygonal shape; Compression coil spring 9 and plate 11 having a central opening 10
Are sequentially accommodated, and these parts are fixed by caulking the upper opening edge of the body 1 to the upper edge of the plate 11. The reason why the outer peripheral portion of the valve body 8 is formed in a polygonal shape is to form a clearance for discharging refrigerant between the inner wall surface of the chamber 4 and the outer peripheral portion of the valve body 8. Reference numeral 12 in the figure denotes a thread provided at an end on the pressure input side, which can be connected to a piping system of a fluid to be controlled. Reference numeral 13 denotes an O-ring for sealing.

When the pressure in the refrigerant circuit becomes higher than the set pressure, the valve body 8 overcomes the pressing force of the compression coil spring 9 and separates from the valve seat 3, and the refrigerant gas flows from the inlet 2 to the outer peripheral portion of the valve body 8. (The gap between the chamber 4 and the valve body 8) passes through the opening 10 of the plate 11 and is released into the atmosphere in the axial direction of the body 1, and when the pressure in the circuit drops, the force of the compression coil spring 9 causes it. The valve body 8 gradually descends, and the valve body 8 returns to the original position, so that the elastic packing 7 closes the valve seat 3.

[0004]

As described above, in the conventional relief valve, since the bottom of the chamber 4 is located at an upper position considerably away from the male screw 12, it can be downsized especially in the height direction. There was a problem that it was not possible.

[0005]

In the relief valve of the present invention, the bottom of the chamber formed inside the metal body is positioned at the same or lower position as the upper end of the screw relief formed at the lower end of the male screw. An object of the present invention is to reduce the size of the relief valve without deteriorating the strength of the relief valve.

[0006] In other words, the relief valve of the present invention, under
A chamber in a metal body 1 having a screw 12 at the end
A valve body 8 formed by providing an opening 6 in the center of the lower surface above the valve seat 3 provided in the center of the bottom of the chamber 4 and fitting an elastic packing into the opening 6; A coil spring 9 and a plate 11 having a through hole 10 in the center are sequentially housed, and the upper opening edge of the body 1 is
1 In a relief valve fixed by caulking to an upper edge, a screw relief portion 12 is provided at a lower end portion of the male screw 12.
a, so that the position of the bottom of the chamber 4 is equal to or lower than the upper end position of the screw relief portion 12a.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of the relief valve of the present invention. The relief valve according to the present invention is similar to the conventional valve in that the metal valve 1 has a screw 12 at its lower end.
A chamber 4 is provided and provided at the center of the bottom of the chamber 4.
The opening 6 is provided in the center of the lower surface above the three valve seats.
A valve body 8 having an outer peripheral portion formed in a polygonal shape formed by fitting an elastic packing 7 therein, a compression coil spring 9, and a plate 11 having a through hole 10 in the center are sequentially housed. The upper opening edge of the body 1 is fixed by caulking the upper edge of the plate 11.

[0008] The relief valve of the present invention, the metallic ball
A thread relief 12a is provided at the lower end of the male thread 12 of the die 1, and the position of the bottom of the chamber 4 is the same as the upper end of the thread relief 12a or reaches a lower position. Therefore, the dimension in the height direction is extremely shorter than the conventional product.

In the relief valve of the present invention, when the relief valve is mounted in the piping of the refrigeration cycle by the above-mentioned screw relief portion 12a, a stress is generated in the outer thread portion of the lower end toward the inward direction of the body 1. However, in the relief valve of the present invention, since the position of the valve seat 3 is located at the same position or below the upper end position of the screw relief portion 12a, the stress is not directly applied to the valve seat 3 and the valve seat is deformed. I will not let you. Therefore, the bottom of the chamber 4 can be lowered to the extreme position.

[0010]

According to the relief valve of the present invention, since the position of the bottom of the chamber 4 is located below the position of the escape portion 12a of the male screw 12, the dimension in the height direction can be made extremely shorter than that of the conventional product. it can.

When the relief valve is installed in the piping of the refrigeration cycle, even if stress is generated at the lower end of the male screw toward the inward direction of the body 1 by the above-mentioned screw relief portion 12a, the valve seat 3 can be used. Is located at the same or lower position as the upper end position of the screw relief portion 12a, so that the stress does not directly act on the valve seat 3, so that the valve seat is not deformed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a relief valve of the present invention.

FIG. 2 is a longitudinal sectional view of a conventional relief valve.

[Explanation of symbols]

1 body 2 pressure inlet 3
Valve seat 4 Chamber 5 Shoulder 6
Opening 7 Elastic packing 8 Valve 9
Compression coil spring 10 Full-year hole 11 Plate 12
Male screw 12a Screw escape.

Claims (1)

(57) [Claims] 1. A metal body having a screw 12 at a lower end.
1, a chamber 4 is provided, and a bottom center of the chamber 4 is provided.
A valve body 8 formed by providing an opening 6 in the center of the lower surface above the valve seat 3 provided on the
And a compression coil spring 9 and a plate 11 having a through hole 10 in the center are sequentially housed, and a relief valve fixed by caulking an upper opening edge of the body 1 to an upper edge of the plate 11 is provided. A relief valve, characterized in that a screw relief portion 12a is provided at a lower end portion of the chamber 4 so that a position of a bottom portion of the chamber 4 is equal to or lower than an upper end position of the screw relief portion 12a.