JP2683285B2 - Pipe fitting structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pipe joint structure.

[Conventional technology]

FIG. 3 shows a conventional joint structure of a gas pipe made of cast iron pipe.

As shown in FIG. 3, in the conventional pipe joint structure, an inlet pipe 1 having a projection 1A formed on the inner surface thereof and a spigot ring 6 fixed to an end thereof are inserted into the inlet pipe 1. A backup ring 3, a round rubber ring 4 and a square rubber ring 5 are inserted between the pipe 2 and the push ring 8 that abuts the square rubber ring 5 by a bolt 7 that is screwed into the flange 1B of the socket pipe 1. It was something to do.

According to the above-described conventional pipe joint structure, when a pulling force acts on the pipe, the backup ring 3 comes into contact with the spigot ring 6 and the receiving pipe 1 is removed from the insertion pipe 2 as shown in FIG. Prevent it from coming out.

[Problems to be solved by the invention] However, when an excessive pulling force acts on the pipe due to an earthquake or the like, the round rubber ring 4 and the square rubber ring 5 fly out from between the push ring 8 and the socket pipe 1. However, the seal of the pipe joint might be broken.

Therefore, an object of the present invention is to provide a pipe joint structure in which the seal of the pipe joint is not broken even if an excessive drawing force acts on the pipe due to an earthquake or the like.

[Means for solving the problem]

According to the present invention, a backup ring, a round rubber ring, and a square rubber are provided between an inlet pipe having a projection formed on an inner surface thereof and an inlet pipe having a spigot ring fixed to an end thereof and inserted into the inlet pipe. In a pipe joint structure in which a ring is inserted, and a push ring that abuts against the square rubber ring is pressed by a bolt that is screwed into the flange of the insertion tube, a lock is provided between the spigot ring and the backup ring. A ring is provided, and the lock ring is characterized by being expanded by the backup ring and being sandwiched between the spigot ring and the projection of the socket pipe when a pulling force acts on the pipe. Is.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a pipe joint structure according to an embodiment of the present invention.

As shown in FIG. 1, the pipe joint structure of the present invention has an insertion pipe 1 having a projection 1A formed on an inner surface thereof and a spigot ring 6 fixed at an end thereof, and inserted into the reception pipe 1. The backup ring 3, the round rubber ring 4 and the square rubber ring 5 are inserted between the mouth pipe 2 and the push ring 8 abutting against the square rubber ring 5 by the bolt 7 screwed to the flange 1B of the socket pipe 1. In the pipe joint structure consisting of pressing, a lock ring 9 is provided between the spigot ring 6 and the backup ring 3.

The lock ring 9 is made of FRP or steel having excellent elasticity and compressive force, and its tip is tapered. Therefore, when the pulling force acts on the pipe, the lock ring 9 is moved to the backup ring 3 as shown in FIG.
It is pushed and spread by the tip of the and is sandwiched between the spigot ring 6 and the projection 1A of the socket 1. As a result, even if a pulling force is applied to the pipe, the round rubber ring 4 and the square rubber ring 5 may be ejected from between the push ring 8 and the socket pipe 1 and the sealing of the pipe joint may be broken. There is no.

The lock ring 9 may be provided with radial slits on its outer peripheral portion so that the lock ring 9 can easily spread.

〔The invention's effect〕

As described above, according to the present invention, the lock ring 9 is sandwiched between the spigot ring 6 and the backup ring 3 even if an excessive pulling force acts on the pipe due to an earthquake or the like. The ring 4 and the square rubber ring 5 do not come out from between the push ring 8 and the socket pipe 1 to the outside, and there is a useful effect that the seal of the pipe joint is not broken.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a pipe joint structure of an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a state when a drawing force is applied to a pipe, and FIGS. 3 and 4 are conventional drawings. 3 is a cross-sectional view showing the pipe joint structure of FIG. In the drawing, 1 ... Receiving pipe, 2 ... Inlet pipe, 3 ... Backup ring, 4 ... Round rubber ring, 5 ... Square rubber ring, 6 ... Spigot ring, 7 ... Bolt, 8 ... … Push ring, 9 …… Lock ring.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuyoshi Hoshino 4-18-15 Bunzo, Urawa-shi, Saitama (72) Inventor Takanori Ito 1-33-1 Ebisu Nishi, Shibuya-ku, Tokyo (56) References Japanese Patent Publication Sho 61-20758 (JP, B2)

Claims (1)

(57) [Claims] 1. A backup ring, a round rubber ring, and a corner are provided between an inlet pipe having a projection formed on an inner surface thereof and an inlet pipe having a spigot ring fixed to an end thereof and inserted into the inlet pipe. In a pipe joint structure in which a rubber ring is inserted and by which a push ring that abuts against the square rubber ring is pressed by a bolt that is screwed into the flange of the insertion tube, between the spigot ring and the backup ring, A lock ring is provided, and when the pulling force acts on the pipe, the lock ring is spread by the backup ring and is sandwiched between the spigot ring and the projection of the receiving pipe. Pipe joint structure.