JPH0949576A - Relief valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize miniaturization of a relief valve without damaging the strength of the relief valve by providing a screw relief part at a male screw lower end part, extending the bottom part of a chamber to this screw relief part. SOLUTION: At a relief valve, a valve body 8 made up by being provided with an opening 6 that exists at the center of a lower surface and at the upper part of a valve seat 3 part in a metal body 1 and by being fitted with an elastic body packing 7 in the opening 6; a compression spring 9; and a plate 11 having a through-opening 10 at its center are housed in order, and by calking the upper part opening edge of the body 1 at the plate 11 upper edge, fixation is carried out, and screw relief pert 12a is provided at the lower end pert of a male screw 12, and a position of the bottom part of a chamber 4 is arranged so that it may be the same as the position of the relief part 12e upper end of the male screw 12 or may reach the lower part position.

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 refrigerating cycle such as a car air conditioner, and more particularly to a screw having a lower end of a male screw formed at the bottom of a chamber formed inside a metal body. The relief valve is extremely miniaturized by extending to the same position as the upper end position of the relief portion or a position below.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional relief valve. In the relief valve, a pressure introducing port 2 having a diameter smaller than that of a pressure introducing port 2 is formed inside a metal body 1 having a cylindrical outer peripheral portion. 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 provided on the upper opening edge of the body 1.
A shoulder 5 for mounting 0 is provided. Then, above the valve seat 3 in the chamber 4, an opening 6 is provided in the center of the lower surface, and a valve body 8 having an outer peripheral portion formed into a polygonal shape by fitting an elastic packing 7 in the opening 6, A compression coil spring 9 and a plate 11 having a through hole 10 in the center
Are sequentially stored, and these parts are fixed by caulking the upper opening edge of the body 1 to the upper edge of the plate 11. In addition, 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 the refrigerant between the inner wall surface of the chamber 4 and the outer peripheral portion of the valve body 8. Further, reference numeral 12 in the drawing denotes a male screw provided at the end portion on the pressure introducing side, which can be connected to a piping system or the like of a fluid to be controlled. Reference numeral 13 is 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 moves away from the valve seat 3, and the refrigerant gas is introduced from the inlet 2 into the outer peripheral portion of the valve body 8. It is discharged into the atmosphere from the opening 10 of the plate 11 through the (gap between the chamber 4 and the valve body 8) in the axial direction of the body 1, and when the pressure in the circuit drops, the force of the compression coil spring 9 The valve body 8 gradually descends, the valve body 8 returns to its original position, and the elastic packing 7 closes the valve seat 3.

[0004]

As described above, in the conventional relief valve, since the bottom portion of the chamber 4 is located at the upper position, which is considerably distant from the male screw 12, it is possible to reduce the size particularly in the height direction. There was a problem that I could not do it.

[0005]

The relief valve of the present invention is such that the bottom portion of the chamber formed inside the metal body is located at the same position as the upper end position of the screw relief portion formed at the lower end portion of the male screw or at a lower position. The purpose of the extension is to reduce the size of the relief valve without impairing the strength of the relief valve.

That is, in the relief valve of the present invention, an opening 6 is provided in the center of the lower surface above the valve seat 3 in the metallic body 1, and an elastic packing 7 is fitted in the opening 6 to form a valve body 8. And a compression coil spring 9 and a plate 11 having a through hole 10 in the center are sequentially stored, and in the relief valve fixed by caulking the upper opening edge of the body 1 to the upper edge of the plate 11, the male screw 12 Is provided at the lower end portion thereof so that the position of the bottom portion of the chamber 4 reaches the same position as the upper end position of the screw relief portion 12a or the lower position thereof.

[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 vertical sectional view of a relief valve of the present invention. The relief valve of the present invention has an outer peripheral portion in which an opening 6 is provided in the center of the lower surface above the valve seat 3 in the metal body 1 and an elastic packing 7 is fitted in the opening 6 just like the conventional product. A valve body 8 having a polygonal shape, a compression coil spring 9, and a plate 11 having a through hole 10 in the center are sequentially housed. These parts are arranged such that the upper opening edge of the body 1 is located at the upper edge of the plate 11. It is fixed by tightening.

In the relief valve of the present invention, the escape portion 12a for the screw is provided in the lower half portion of the external thread 12, and the position of the bottom of the chamber 4 is the same as the upper end position of the screw escape portion 12a. Or it has reached a position below, and the dimension in the height direction is extremely shorter than that of the conventional product.

In the relief valve of the present invention, when the relief valve is attached to the piping of the refrigeration cycle by the above-described screw relief portion 12a, a stress is generated in the innermost thread of the body 1 at the lowermost male thread portion. However, in the relief valve of the present invention, since the position of the valve seat 3 is the same as or lower than the upper end position of the screw relief portion 12a, the stress does not directly act on the valve seat 3 portion, so the valve seat is deformed. There is nothing to do. Therefore, the bottom of the chamber 4 can be lowered to the extreme position.

[0010]

In the relief valve of the present invention, since the position of the bottom of the chamber 4 is 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. Further, when the relief valve is installed in the piping of the refrigeration cycle, the screw relief portion 1 described above is used.
Even if a stress is generated in the lower end portion of the male screw in the inward direction of the body 1 by the 2a, the position of the valve seat 3 is changed to the screw relief portion
Since the stress is not directly applied to the valve seat 3 portion, the valve seat is not deformed because it is located at or below the upper end position.

[Brief description of drawings]

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

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

[Explanation of symbols]

1 Body 2 Pressure introduction hole 3
Valve seat 4 chamber 5 shoulder 6
Opening 7 Elastic body packing 8 Valve body 9
Compression coil spring 10 Vent hole 11 Plate 12
Male thread 12a Screw relief section

Claims (1)

[Claims] 1. A valve body 8 in which an opening 6 is provided in the center of a lower surface above a valve seat 3 in a metal body 1 and an elastic packing 7 is fitted in the opening 6, and a compression coil spring 9, And a plate 11 having a through hole 10 in the center are sequentially housed, and the relief valve is fixed by caulking an upper opening edge of the body 1 to an upper edge of the plate 11, wherein a screw escape portion is provided at a lower end portion of the male screw 12. 12a is provided so that the position of the bottom of the chamber 4 reaches the same position as the upper end of the screw relief portion 12a or the lower position thereof.