JPH0911040A - Scraper for plastic pipe - Google Patents

Abstract

PURPOSE: To provide a tool thinly scraping the surface of a plastic pipe exposed to the inside of steel pipe. CONSTITUTION: A shaft hole 14 is formed in the center of a base board 10, in which fixing legs 11 to be fixed to the circumference edge of a hole formed in a steel pipe are formed on the lower face, and a rotary shaft 15, in which an engaging part 16 for a rotary tool is formed in the upper end, is inserted into the shaft hole 14, while a blade mounting arm 18, in which a blade 22 is installed downward, is mounted via a horizontal mounting member 17 in the lower end of the rotary shaft 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe having a plastic pipe inserted into the inner surface thereof, and after forming a branching hole in a part of the steel pipe, a virgin layer is formed on the surface of the plastic pipe exposed in the hole. Regarding the scraper to do.

[0002]

2. Description of the Related Art A gas pipe or a water pipe in which a plastic pipe (layer) is formed inside a steel pipe to protect the steel pipe from corrosion or repair the steel pipe is known. When taking out a branch pipe from such a steel pipe, if the branch side is metal, it is possible to branch using a saddle or a clamp, but a plastic branch member is directly attached to the plastic pipe inside the steel pipe. When fusing and taking out, scrape off the surface of the plastic pipe exposed in the hole drilled in the steel pipe,
It is necessary to expose the plastic virgin layer and fuse the plastic branch member there.

FIG. 5 shows an example of this branching, 1 is a steel tube having a plastic tube 2 inserted into its inner surface, 3 is a hole perforated in the branching portion, 4 is a branching member, and this branching member 4 is As shown in FIG. 6, an electric heater wire 5 is attached to the fusion surface, and the electric heater wire 5 is energized to generate heat, and the heat causes the surface of the plastic tube 2 and the fusion surface to melt to melt the plastic tube 2. It is designed to be fused to.

[0004]

When the branch pipe is taken out by the above-mentioned fusion method, the surface of the plastic pipe 2 is often deteriorated or not smooth, and if the fusion is performed as it is, poor fusion will occur. . Therefore, conventionally, the surface of the plastic pipe 2 is scraped off before the fusing to expose the virgin layer, and then the fusing is performed. However, since the tool for producing this virgin layer is a work in a small hole, there is no suitable one, and sandpaper is used or a method such as shaving thinly with a tool such as a chisel is taken. There is. For this reason, there are drawbacks that the surface cannot be neatly finished and the work is troublesome.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and the constitution thereof is as follows. A fixed leg that can be fixed to the periphery of the hole drilled in the steel pipe is attached to the lower surface, a base with a shaft hole in the center and an engaging part of the rotary tool at the upper end are formed, A rotary shaft that is vertically movably inserted, a mounting member that is horizontally fixed to the lower end of the rotary shaft, a base that is rotatably supported by the mounting member, and a blade on the tip side. A scraper for a plastic pipe, comprising: a blade mounting arm that is attached downwardly and a spring that applies a downward rotating force to the blade mounting arm.

[0006]

A hole is made in a steel pipe to be processed by using a saw until the inner plastic pipe is exposed, and the lower end of the fixing leg of the scraper is fixed to the edge of the hole. Then, when the spindle of the rotary tool is fitted to the engaging portion formed at the upper end of the rotary shaft and the rotary shaft is rotated, the blade mounting arm initially stands by the force of the spring, and Rotate with drawing a small circle in the center. Then, when the rotary shaft is pushed down little by little, the blade mounting arm displaces the plastic pipe surface in the radial direction against the spring, and as a result, the rotational radius of the blade gradually expands. By thus pushing down while rotating the rotary shaft, the blade scrapes the surface of the plastic pipe in the radial direction from the center to expose the virgin layer. The branch member is
The virgin layer thus formed is fused by the heat of the electric heater wire.

[0007]

EXAMPLE FIG. 1 shows an example of the scraper according to the present invention. 10 is a circular base, and a rotary shaft hole 14 is formed in the center thereof. Reference numeral 11 is a fixed leg formed downward from the periphery of the base 10, 12 is an engaging step formed at the lower end of the fixed leg 11, and 13 is the fixed leg 11.
It is a fixing screw that is fixed to.

Reference numeral 15 designates an engaging portion 16 for engaging a spindle of a rotating machine at an upper end thereof, and a rotary shaft slidably inserted in a rotary shaft hole 14 of the base 10 up and down, and 18 is the rotary shaft. A blade mounting arm rotatably attached to the lower end of 15 by a support shaft 19 through a mounting member 17, and a blade 22 is attached downward to the tip of the arm, and a spring 20 is provided by a spring 20. In FIG. 1, the force is applied in the clockwise direction (downward), and in an unloaded state, the angle is almost vertical. 2 in the figure
Reference numeral 1 is a connecting rod of the left and right blade mounting members 18, and 23 is a blade mounting screw.

In the scraper of the above embodiment, as shown in FIG. 3, a hole 3 formed by drilling the step 12 of the fixed leg 11 in the steel pipe 1.
It is attached by engaging the edge 31 of the inside from the inside. At this time,
The rotary shaft 15 is a spring 20 acting on the blade mounting arm 18.
It has been lifted upward by the reaction force of. In this state, the rotating shaft 1
When the spindle a of the rotating machine is fitted into the engaging portion 16 at the upper end of the rotary shaft 5 and rotated, the blade 22 rotates around the rotary shaft 15 while drawing a small circle to scrape the surface of the plastic pipe 2. Then, when the rotary shaft 15 is pushed down against the force of the spring 20, the blade mounting arm 18 gradually expands, scraping the surface of the plastic tube 2 while gradually drawing a large circle from a small circle, and eventually the figure. As shown in 4, the maximum circle is drawn. At this point, the predetermined area has been scraped off, so the work is completed.

The central portion of the hole 3 remains without being scraped off, but since the branch opening is bored in this central portion, there is no problem even if this central portion remains. The method of fusing the branching member 4 is the same as the conventional example.

[0011]

As described above, according to the present invention, since the surface of the plastic pipe can be automatically scraped in the hole of the steel pipe, the work is more efficient than the conventional manual method. In addition, the scraped surface becomes a smooth and beautiful virgin layer, which enables reliable fusion bonding.

[Brief description of the drawings]

FIG. 1 is a perspective view of a scraper according to the present invention.

FIG. 2 is a plan view of a blade mounting arm portion.

FIG. 3 is an explanatory diagram at the beginning of the use state of the scraper.

FIG. 4 is an explanatory diagram of the end of the usage state of the scraper.

FIG. 5 is an explanatory view of a situation in which a branch pipe is taken out from a steel pipe having a plastic pipe inserted inside by using a plastic branch member.

FIG. 6 is an explanatory view of a situation in which the branch member is fusion-bonded to the plastic pipe exposed in the hole of the steel pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel pipe 2 Plastic pipe 3 Hole 4 Branch member 5 Electric heater wire 10 Base plate 11 Fixed leg 12 Step part 13 Fixing screw 14 Bearing hole 15 Rotating shaft 16 Engagement part 17 Mounting member 18 Cutlery mounting arm 19 Support shaft 20 Spring 21 Continuous rod 22 cutlery 23 cutlery mounting screw

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location // B29L 23:00 (72) Inventor Tetsuro Naganuma 2-11-2 Kajigaya, Takatsu-ku, Kawasaki-shi, Kanagawa

Claims (1)

[Claims] 1. A base formed by attaching a fixed leg, which can be fixed to a peripheral edge of a hole drilled in a steel pipe, to a lower surface of the steel pipe, and a shaft hole formed at a center thereof, and an engaging portion of a rotary tool formed at an upper end thereof. A rotary shaft vertically movably inserted into the hole from above, a mounting member horizontally fixed to a lower end of the rotary shaft, and a base portion rotatably supported on the mounting member. A scraper for a plastic pipe, comprising: a blade mounting arm having a blade mounted downward on a tip side thereof; and a spring imparting a downward rotating force to the blade mounting arm.