JPH0423151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a check valve used in a refrigeration system, etc., and in particular to a check valve that is installed inside a pipe to facilitate piping connection by brazing to a piping pipe. be.

Conventional configuration and its problems A conventional example is shown in FIG. 1 and will be explained.

In the figure, a is a check valve in which a hinge type valve b is housed inside a pipe c. This check valve a has a cylindrical valve body d.
One end surface of the valve is cut off at an angle, and a valve seat e is formed on this inclined surface. On the other hand, the locking hole f at the upper end of the valve b is supported by a locking pin h press-fitted into a step g continuous to the valve seat e. Due to the arrangement of the inlet hole i, the inlet hole i is formed to be offset downward from the axis of the valve body d. Such a valve body d is inserted into a pipe c, the outer periphery is sized and a bead j is formed using a roll, and the deformed material is press-fitted into an annular groove k formed on the outer peripheral surface of the valve body d. Fix and seal d and pipe c.

However, during this sizing process, the valve body d is deformed, and this deformation extends to the valve seat e, resulting in a disadvantage that the flatness of the valve seat changes and the amount of leakage increases when the valve is closed. In addition, the eccentric entrance hole further promoted deformation.

Technical Problem of the Invention In order to improve this drawback, the present invention aims to prevent deformation of the valve seat surface during sizing processing.

Structure of the Invention According to the present invention, a buffer groove for preventing deformation is formed closer to the valve seat than the groove for sizing.

Effect of the Invention With this configuration, deformation during sizing processing is prevented from reaching the valve seat side by the buffer groove.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

1 is an internal pipe check valve (hereinafter simply referred to as a check valve), 2 is an external pipe, and 3 is an external pipe check valve.
is a cylindrical valve body housed inside this pipe 2. This valve body 3 has a bore portion 4 formed concentrically, and an inlet hole 5 having a smaller diameter than the bore portion 4 and extending downwardly and eccentrically in the axial direction.
Reference numeral 6 designates a valve seat formed by cutting the valve body 3 at an angle and subjecting it to a lapping process. A valve 7 has a T-shaped locking portion 8 at its upper end and a horizontal locking groove 9 at one end, and is made of flapper sheet material. Numeral 10 is a U-shaped locking piece having a pair of engaging portions 11 that engage with the locking groove 9, and a stopper portion 12 that restricts the press-fitting amount of the engaging portions 11. Further, reference numeral 13 denotes a hole into which the engaging portion 11 is press-fitted and fixed, and is provided at right angles to the valve seat 6.
14 inserts the valve body 3 into the pipe 2 and creates a bead 15 in the pipe 2 by sizing process.
It is a concave groove that receives the plastically deformed deformable member when it is formed, and is formed in an annular shape. Further, this groove 14 is located on the outside of the bore portion 4. Reference numeral 16 denotes a buffer groove for buffering deformation, which is formed between the groove 14 and the valve seat 6 so as to be parallel to the groove 14. Note that 17 is a filter, and 18 is a stepped portion on which the open end of the filter 17 is attached.

Effects of the Embodiment In this configuration, the valve 7 is pre-assembled to the valve body 3 using the locking piece 10, and the filter 17 is further attached so that one end of the filter 17 is attached before the diameter is reduced as shown by the two-dot chain line in FIG. After inserting into pipe 2 and positioning, start sizing process of pipe 2 and make bead 15.
form. At this time, due to the concentricity of the bore 4 and the buffer groove 16, the material of the pipe 2 can be deformed uniformly along the entire circumference, and the groove 14 can be sufficiently filled. Concave groove 1
The deformation around the valve seat 4 does not extend to the valve seat 6 due to the buffer groove 16.

Effects of the Invention The present invention has such a configuration, so that even if the inlet hole is formed eccentrically in the valve body, deformation of the valve body will not reach the valve seat when the valve body is fixed by pipe sizing processing. Therefore, the flatness does not deteriorate, the amount of valve leakage is reduced, and high sealing performance can be maintained.
Furthermore, since sufficient sizing processing can be performed, the sealing performance between the pipe and the valve body can be improved.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a conventional check valve.
FIG. 2 is a sectional view of a pipe-internal check valve showing an embodiment of the present invention, and FIG. 3 is an exploded perspective view of the main parts. 3...Valve body, 2...Pipe, 5...Inlet hole, 6...Valve seat, 15...Bead, 1
4...Concave groove, 16...Buffer groove.

Claims (1)

[Claims] 1 Comprising a cylindrical valve body and a pipe that houses the valve body, the valve body has an eccentric inlet hole extending substantially in the axial direction, a valve seat connected to the inlet hole, and a bead formed by sizing the pipe. A pipe-internal check valve is provided with an annular groove located on the outer peripheral surface of the valve and a buffer groove located between the groove and the valve seat.