JPH0547352Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to a coupling device for synthetic resin pipes buried underground by the propulsion method.

[Conventional technology]

Conventional synthetic resin pipes such as hard vinyl chloride pipes are lightweight and have excellent corrosion resistance, so
It is widely used as a piping material for water and sewage systems, but because it is a flexible pipe, it cannot be buried underground using the propulsion method like rigid pipes such as Hiccomb pipes, ceramic pipes, steel pipes, and cast iron pipes.

For this reason, conventionally, they are buried underground using the open-cut construction method, but for pipes such as water and sewage pipes, which are often buried under roads, the open-cut construction method, which occupies the road, has problems such as causing traffic congestion. It was hot.

In order to improve this problem, propulsion devices and propulsion methods have been developed that enable the propulsion of pipes without applying large forces to the pipes being propelled. It is now possible to bury it.

[The problem that the idea aims to solve]

However, as shown in Fig. 5A, joints for pipe bodies buried underground using the conventional propulsion method involve liquid-tightly joining the joints of pipe bodies a and b that are butted against each other with a sleeve c, or As shown in Fig. 5b, the pipes a and b are connected by threads, whereas the joints conventionally used to connect synthetic resin pipes are as shown in Fig. 6 a, b, and c. , since the joint d protrudes from the outer periphery of the tubes a and b by h, it is necessary to drill a hole from the propulsion head with an inner diameter that allows the joint d to pass through during propulsion. The relationship between the outer diameter D ₀ of the propulsion head e and the outer diameter D ₁ of the joint d is set so that D ₀ D ₁ >D. Note that D is the outer diameter of tubes a and b.

As a result, a void f as shown in Figure 8 is generated around the pipes a and b buried underground, which causes the ground to loosen and the earth pressure acting on the pipe surface due to wheel loads on the road. The distribution becomes uneven, leading to uneven settling of the pipe and deformation of the pipe, which may result in damage to the pipe.

In addition, in the joints shown in Figures 6A and 6C that connect pipe bodies a and b using adhesive, thrust, force, changes, etc. during propulsion act on the adhesive part during the curing period of the adhesive. In addition, the reliability after burial is low due to a decrease in the amount of adhesion and poor adhesion, and the connection between tubes a and b during propulsion is poor in the joint using the rubber seal ring g shown in Figure 6 (b). There were some problems, such as the risk of it coming off.

This invention was made with the aim of improving the above-mentioned problems, and is intended to provide a synthetic resin pipe coupling device suitable for the propulsion method.

[Means and actions for solving the problem]

In order to achieve the above object, this invention was developed in a propulsion method in which a pipe body made of synthetic resin is propelled into the ground by a propulsion device and buried. By forming a reinforcing sleeve around the threaded portion of each tube, it is possible to propel the tube without applying a large force to the connecting portion of each tube. By reinforcing the connection part with a sleeve, we have made it possible to connect synthetic resin pipes that are propelled underground using the propulsion method.

In addition, the gap formed between the threaded part of each tube and the sleeve is filled with sealing material to enhance the sealing effect, and the sleeve is made of a thin metal plate to reduce resistance during propulsion. To provide a synthetic resin pipe joint device that eliminates problems such as ground subsidence by preventing gaps from forming around the pipe body.

〔Example〕

One embodiment of this invention will be described in detail with reference to the drawings. In the figure, 1 is a tube body made of a hard vinyl chloride tube, etc., and the propulsion head 2 shown in FIG. 3 A and B is attached to the tip. It is designed to be propelled underground by a propulsion device (not shown). Note 2
a is a metal lead pipe.

Reference numeral 3 denotes a joint body that connects the advanced pipe body 1 and the succeeding pipe body 1, which includes a female threaded part 3a formed at the connection part of each pipe body 1, a male threaded part 3b screwed into this female threaded part 3a, and It consists of a sleeve 3c surrounding the outer periphery of the connection part.

The female threaded portion 3a and the male threaded portion 3b are square threads that correspond to the wall thickness of the tube body 1, and are designed to prevent stress from being concentrated at the corners and root portions of the valley side, as shown in Fig. 2. Small arcuate portions R ₁ , R ₂ , and R ₃ are formed, respectively, and the length of the female threaded portion 3a is made shorter by α than the length l of the male threaded portion 3b, and the tip of the female threaded portion 3a and male thread part 3
A gap 3e for filling the sealing material 4 is formed at the base of b.

The sealing material 4 is used to prevent water leakage and especially inflow of sewage from the outside, and is used in the threaded portions 3a and 3b.
A material with high viscosity that does not twist due to compaction movement and a little fluidity is used, and a water-swellable sealing material that expands by absorbing moisture after solidification is used.

On the other hand, the sleeve 3c surrounding the connection part is
It functions as a reinforcing material that increases the impact resistance of the connection part, and is formed by processing a thin plate of stainless steel or the like into a cylindrical shape.

The length is 2 on the female threaded portion 3a side and 1 on the male threaded portion 3b side.
A stopper 3d that prevents displacement due to resistance with the soil during propulsion is protruded in an annular shape, and both ends thereof are fitted into small diameter portions 1a formed on the outer peripheral surface of each tube 1. The outer circumferential surface of the sleeve 3c and the outer circumferential surface of the sleeve 3c are configured to be substantially on the same plane.

Next, to explain the operation, when propelling the tube 1 underground, first attach the propulsion head 2 shown in FIG. The pipe body 1 is propelled underground while drilling the hole.

When the propulsion for a unit length is completed, first, as shown in Fig. 4A, the stopper 3d of the sleeve 3c is
The sealing material 4 is arranged in an annular manner on the front surface, and then one end of the sleeve 3c is attached to the trailing pipe body 1 as shown in FIG.
The other end is fitted into the rear end of the tubular body 1 which is already being propelled, and the male threaded portion 3b is screwed into the female threaded portion 3a while rotating the succeeding tubular body 1.

By screwing the succeeding tubes 1 all the way as shown in Fig. 4C, the end surfaces of each tube 1 come into contact with each other, and the connections between the tubes 1 can be made without creating any gaps or steps on the inner surface of each tube 1. At the same time, the sealing material 4 placed on the front surface of the stopper 3d fills the gap 3e and seals.

Further, since this sealing material 4 expands when water or the like enters the pipe during use, the sealing effect becomes even better.

When the connection of the succeeding tube 1 is completed as described above, the tube 1 is propelled underground again, and the above operation is repeated to propel the tube 1 until a predetermined burial distance is reached.

[Effect of idea]

As explained in detail above, this design uses screws to connect each pipe body, making it easy to connect at the propulsion site in a short time. Propulsive force can be efficiently transmitted to the body.

In addition, the valley side corner and root of the square screw are shaped into small arcs to avoid concentration of stress, and the effective cross-sectional area reduced by forming the screw is compensated for by fitting a metal sleeve around the outer periphery of the threaded part. Since this is compensated for by doing so, even if an excessive propulsive force is applied to the threaded portion during propulsion, the screw will not be damaged or deformed.

Furthermore, since the gap between the connections is filled with a water-expandable sealing material, the water absorbed after burial expands the sealing material and increases the sealing function, so the sealing effect will not deteriorate over a long period of time. .

[Brief explanation of the drawing]

The drawings show one embodiment of this invention; Fig. 1 is a side view of the pipe with the joint device section cut away, Fig. 2 is an enlarged view of the circle in Fig. 1, and Fig. 3 A and B are views of the propulsion head. Explanatory diagrams, Figure 4 A to C are action explanatory diagrams, Figure 5 A, B, Figure 6 A, B, C, Figures 7 and 8.
The figure is a conventional explanatory diagram. 1 is a tube body, 3a is a female threaded part, 3b is a male threaded part,
3c is a sleeve, 3d is a stopper, 3e is a gap,
4 is sealing material.

Claims (1)

[Scope of utility model registration request] In a propulsion method in which a pipe body 1 made of synthetic resin is propelled into the ground by a propulsion device and buried, a square screw having a valley side corner and a base formed in a small arc shape is attached to the connection part of the pipe body. A reinforcing calve 3c made of metal is fitted around the threaded portion of each tube 1, and the threaded portion of each tube 1 and the inner surface of the sleeve 3c are formed. A water-swellable sealing material 4 is placed in the gap 3e formed between the
A fitting device for synthetic resin pipes filled with.