JPH0882189A - Propelling pipe - Google Patents

Abstract

PURPOSE: To keep the ends of a pipe in a true round state to make screw-cutting accurately and to obtain a certain and firm connection. CONSTITUTION: A metal ring 2a is fitted to the circumference of one end of a pipe body 1 of synthetic resin and, at the same time, a male screw 11 is provided to the circumference of the pipe end in the front end side from the metal ring 2a. The metal ring 2b is fitted to the circumference of the other end of the pipe body 1 and a female screw 12 screwed in the male screw 11 is provided to the internal circumference of the pipe end to which the metal ring is fitted. By the constitution, screw-cutting is made accurately, and after the connection, the pipe is deformed in a flat-shape to prevent the slippage thereof from the connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion pipe buried in the ground by a propulsion method.

[0002]

2. Description of the Related Art In Japanese Utility Model Laid-Open No. 2-14894, a pipe made of a synthetic resin such as a hard vinyl chloride resin is engraved with a male screw on the outer peripheral surface at one end and a female screw on the inner peripheral surface of the other end. It has been proposed that a male thread of one tube body and a female thread of the other tube body are screwed together, and then a reinforcing sleeve is fitted over the outer peripheral surface of the connecting portion.

[0003]

However, since the tubular body made of synthetic resin is easily deformed into a flat shape, when the male thread or the female thread is engraved at the tube end, the thickness of the threaded portion becomes uneven. In some cases, accurate thread cutting could not be performed. The present invention is to solve the above problems, the end portion of the tube made of synthetic resin can be held in a perfect circular shape for accurate threading, and after connection, the tube is deformed into a flat shape and the connection part The purpose of this is to provide a propulsion tube that does not come off.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a metal ring is fitted on the outer circumference of one end of a tubular body made of synthetic resin, and a male screw is engraved on the outer circumferential surface of the pipe end on the tip side of the metal ring. In addition, a metal ring is fitted into the outer periphery of the other end of the pipe body, and a female screw that is screwed into the male screw is engraved on the inner peripheral surface of the pipe end where the metal ring is fitted. And

[0005]

Since the metal ring is fitted around the end of the tube made of synthetic resin, the tube end is held in a perfect circle by the metal ring, and the wall thickness is uniform and accurate thread cutting can be performed. . Also, even if external force such as earth pressure or wheel load acts on the connection part after the pipe construction, the pipe end is held in a perfect circle by the metal ring, so the pipe may come off at the connection part, or may be flat. It does not deform and break.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the propulsion pipe of the present invention,
FIG. 2 is a partial cross-sectional view showing the connected state of the propulsion pipes, in which reference numeral 1 is a tubular body made of synthetic resin such as hard vinyl chloride resin, and 2a and 2b are rings made of stainless steel and cast iron metal members. Is. The metal rings 2a and 2b have an inner diameter substantially equal to the outer diameter of the tubular body 1, and one end thereof has a tapered surface 21 on the outer peripheral side. The metal ring 2a,
The wall thickness, width dimension, etc. of 2b can be appropriately set according to the outer diameter, etc. of the tubular body 1.

The propulsion pipe of the present invention is a tubular body 1 made of synthetic resin.
The metal rings 2a and 2b are fitted and inserted into both ends of the pipe to hold the pipe ends in a perfect circle shape, and the male screw 11 and the female screw 12 are engraved on the respective pipe ends. When manufacturing this propulsion tube, a metal ring 2a is fitted and inserted into one end of the tube body 1 and fixed so as not to move. At this time, the metal ring 2a is inserted into the tip of the tubular body 1 leaving a thread cutting margin, and the tapered surface 21 of the ring 2a is set to the tube end side. Therefore, a male screw 11 is engraved on the outer peripheral surface of the pipe end portion on the tip side of the metal ring 2a. Next, a metal ring 2b is attached to the outer periphery of the other end of the pipe body 1, and a female screw 12 that is screwed into the male screw 11 is engraved on the inner peripheral surface of the pipe end where the metal ring 2b is fitted. At this time, it is important to set the tapered surface 21 of the metal ring 2b in the same direction as the tapered surface 21 of the metal ring 2a.

In the case of using this propulsion pipe for buried piping, the propulsion device propels the leading propulsion pipe into the ground, and the female screw 12 provided at the rear end of the propulsion pipe is provided at the tip of the subsequent propulsion pipe. The male screw 11 is screwed. At this time, an adhesive may be interposed between the male screw 11 and the female screw 12 for connection. Therefore, press the rear end of the following propulsion pipe with the propulsion device,
After propelling into the ground, connect the next propulsion pipe.

In this propulsion process, when the propulsion pipe is pushed into the ground one after another, the thrust load concentrates on the connection portion and tends to buckle and deform. Since the metal rings 2a and 2b are mounted, the pipe is neither buckled nor deformed and damaged at the connecting portion.
In addition, the pipe body will not be detached at the connection portion due to an external force such as earth pressure or wheel load after the pipe construction, or will not be deformed into a flat shape and damaged.

[0010]

As described in detail above, in the propulsion pipe of the present invention, a metal ring is attached to the outer periphery of the end portion of a synthetic resin pipe body, and the pipe end portion is held in a perfect circular shape by the metal ring. After that, the male and female threads are engraved on each pipe end, so that an accurate screw with a constant wall thickness can be obtained and the connection work can be performed reliably. Further, since the wall thickness of the pipe end portion where the male screw and the female screw are engraved becomes uniform, when the thrust load acts on the connecting portion, stress is not concentrated on the thin portion and the pipe is not damaged at the connecting portion. Furthermore, even if an external force such as earth pressure or wheel load acts on the connection portion after pipe construction, the pipe end is held in a perfect circle by the metal ring, so the pipe body may come off at the connection portion. In addition, it has an extremely excellent practical effect that it is not deformed into a flat shape and is not damaged.

[Brief description of drawings]

FIG. 1 is a sectional view of a propulsion pipe showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a connected state of the propulsion pipes.

[Explanation of symbols]

 1 Tube 11 Male Thread 12 Female Thread 2a, 2b Metal Ring

Claims (1)

[Claims] 1. A propulsion pipe buried in the ground by a propulsion method, wherein a metal ring (2a) is fitted on the outer periphery of one end of a tubular body (1) made of synthetic resin, and the metal ring is also attached. A male screw (11) is provided on the outer peripheral surface of the pipe end portion on the tip side of (2a).
And a metal ring (2b) is inserted into the outer periphery of the other end of the pipe body (1), and the male screw (2b) is inserted into the inner peripheral surface of the pipe end where the metal ring (2b) is inserted. A propulsion tube characterized by being engraved with an internal thread (12) that is screwed with 11).