JPS5912178Y2 - Tools for bending plastic pipes - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tool for bending plastic pipes that can easily bend plastic pipes.

Conventional methods for bending plastic pipes include heating and softening the pipe with a torch, charcoal, or heated sand, and then bending the pipe to a predetermined curvature on the ground.

However, these heating methods may cause partial burns or
This often results in damage to the tube, and it is difficult to uniformly heat the entire part to be bent, resulting in flattening, corner bends, and excessive bending, which not only makes accurate bending impossible, but also makes the work more difficult. It was inefficient.

In order to eliminate the drawbacks of the conventional method, the present invention proposes a heating tool that is equipped with a removable fixture that can be attached and detached with a single touch on a pair of opposing edges of a rectangular flexible surface heater, and a fixing device that is attached to one end of the curvature radius adjusting mandrel. Bending of plastic pipes is carried out using a plastic pipe bending tool consisting of a bending adjustment internal tool with a metal fitting and a plurality of annular flattening prevention guides inserted and a tightening metal fitting on the other end. The purpose of this is to uniformly heat the bending part, and also to enable easy bending with high accuracy not only on the ground but also in excavated grooves.
To obtain a bending tool that is easy to handle and improves work efficiency.

FIG. 1 shows a heating tool which is a surface heater of the present invention, FIG. 1 shows a plan view and FIG. 1 shows a front view.

In the figure, 1 is a flexible mat-like electric heater, and A is a removable fixture consisting of 2a and 2b, such as a snap, magnet, or hook-and-loop fastener (trade name: Velcro).
etc., 3 indicates a power cord, 4 indicates an intermediate switch, and 5 indicates a power plug.

FIG. 2 shows the bending adjustment internal mold tool 13 of the present invention, with figure a showing a front view and figure b showing a side view.

In the figure, 7 is a curvature half-type adjusting mandrel (hereinafter referred to as the mandrel).

), 8 is a flattening prevention guide, 9 is a fastener, 9-1 is a stopper, and 10 is a rope.

A thread portion 7-1 is provided at one end of the mandrel 7, and the fastener 9 is provided with a thread portion that is engaged with the thread portion 7-1.

The flattening prevention guide 8 has a plate-shaped body shaped into a donut-shaped ring.
The outer diameter is slightly smaller than the inner diameter of the plastic tube into which the cable is inserted, and the inner diameter is larger than the outer diameter of the mandrel 7.

The flatness prevention guide 8 is fixed or locked with a fastener 9-1 near the left end of the mandrel 7 in the figure by an appropriate means, and then the required number of flatness prevention guides 8 are inserted into the mandrel 7, and the fastener 9 is inserted into the mandrel 7. The anti-flattening guides 8 can be fixed to each other at desired positions.

Next, a method for bending plastic pipes using the heating tool and bending adjustment internal tool of the present invention will be explained.

First, as shown in FIG. 3, the heating tool 1, which is a surface heater, is wrapped around the plastic tube 6 to be bent.

The plastic tube 6 is shown in cross section. heating tool 1
are joined by a removable fitting A and are heated uniformly over the entire length of the heating tool 1, which is wrapped around a plastic tube 6.

After uniformly heating and softening the plastic pipe 6, as shown in FIG. located in the heating section.

FIG. 4 is a cross-sectional view of a state in which it is bent to be convex upward.

When bent upward to convex as shown in the figure, the upper sides of the inner diameter surfaces 8A and 8F of the flatness prevention guides 8-1.8-6 at both ends abut against the mandrel 7, and the central flatness prevention guide 8-3.8-4 It stops when the lower side of the inner diameter surfaces 8C and 8D abut against the mandrel 7, and even if you try to bend it any further, it will not be possible.

Therefore, the flattening prevention guides 8-1 at both ends and the center.
A predetermined radius of curvature is obtained by bending the inner diameter surface of 8-6.8-3.8-4 until it comes into contact with the mandrel 7, and in this state, the plastic tube 6 is forcibly cooled by air or water.

With the above processing, each flattening prevention guide enables highly accurate bending without flattening.

The bending adjustment inner mold tool B inserted into the plastic tube 6 can be pulled out by a rope 10.

By adjusting the clearance between the outer diameter of the mandrel 7 and the inner diameter of the flattening prevention guide, bending with any radius of curvature is possible.

If the heating tool 1 is combined with a thermostat, it is possible to control the temperature and prevent damage to the plastic pipe due to overheating.

If you use the plastic pipe bending tool of this invention,
Easily attach a heating tool to a plastic tube with a single touch for uniform heating.Bending adjustment The internal tool can be easily inserted into a plastic tube that has been uniformly heated and softened, allowing for highly accurate bending with the required radius of curvature. .

The tool of this invention has a simple structure and is easy to handle, so it can be bent freely not only on the ground but also in excavated trenches, improving work efficiency, avoiding underground objects, etc., and efficiently performing piping construction. This brings about effects such as making it possible.

[Brief explanation of the drawing]

Figure 1 is a heating tool of the present invention, figure a is a plan view, figure b is a front view, figure 2 is a bending adjustment inner mold tool of the present invention, figure a is a plan view,
Figure b is a side view, Figure 3 is a cross-sectional view of a plastic tube with the heating tool of the present invention attached to the plastic tube, and Figure 4 is a bending process performed by inserting a bending adjustment internal tool into a plastic tube that has been softened by heating. A cross-sectional view of the state is shown. 1: Heating tool, 2a, 2b: Detachable fixture, 6: Plastic pipe, 7: Mandrel, 8.8-1 to 8-6: Flattening prevention guide, 9: Fastener, 9-1: Stopper, 10 :rope.

Claims (1)

[Scope of utility model registration request] A heating tool is provided with detachable fittings that can be attached and detached with one touch on a pair of opposing edges of a rectangular flexible surface heater, and a plurality of annular flattening prevention guides are provided with a stopper on one end of the curvature radius adjustment mandrel. A tool for bending plastic pipes, which consists of a bending adjustment internal mold tool that is inserted into one end and has a clamping fitting on the other end.