JPH08178165A - Cutter for drilling for branch joint - Google Patents

Abstract

PURPOSE: To provide a cutter for drilling capable of performing a drilling work without needing a high force and preventing entrance of chips to a main pipe during a drilling work. CONSTITUTION: The blade surface 23 of the tip of the blade part 22 of a cutter 21 for drilling consists of a wave-form sharp edge based on the screw-in direction of the cutter 21 for drilling. Thus, when the cutter 21 for drilling is rotated in a given direction during drilling, the blade part 22 is rotated integrally with a rotation part 4a and cuts through the main pipe 2. In this case, the part protruded to the main pipe 2 side of the waveform blade surface 23 is repeatedly cut through the main pipe 2 at intervals of a specified angular distance. A friction force against a peripheral direction is reduced and drilling is effected as the cutter 21 for drilling is rotated with a comparatively low force. Further, since the blade surface 23 is gently curved, chips are prevented from generation during drilling, and the chips are prevented from entering the main pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade for drilling which is installed in a branch joint for joining a resin-made base pipe and a resin-made branch pipe.

[0002]

2. Description of the Related Art In recent years, resin pipes made of polyethylene or the like have been used as gas pipes buried in the ground. Compared with steel pipes that have been used as gas pipes, this resin pipe has excellent corrosion resistance, so there is no electrical action under buried conditions, corrosion of acidic soil, etc., and excellent chemical resistance. Since it is not affected by chemical substances and has flexibility, it can follow the ground as it is and cause bending damage like a steel pipe even when the ground changes or is improperly submerged during an earthquake. There is no advantage.

In this type of gas pipe, there is a branch joint shown in FIG. 5 as a branch joint for connecting a polyethylene main pipe and a polyethylene branch pipe. The branch joint 1 is provided with a substantially semi-cylindrical base pipe fusion part 3 to be joined to the base pipe 2 and a vertical standing from the base pipe fusion part 3, and a piercing blade 4 (Fig. 6).
(See FIG. 7) and a tubular body portion 5 in which is internally provided, and a tubular branch portion 8 that extends from the body portion 5 in a vertical lateral direction and is connected to a branch pipe 7 through a socket 6. It is composed of a cap body 9 that is exteriorly mounted on the end of the body 5,
Except for the punching blade 4, it is made of polyethylene.

As shown in FIG. 8, a heating wire 10 is embedded in a spiral shape on the inner surface of the main tube fusion part 3 to be fused to the main tube 2, and this heating wire 10 is fused to the main tube fusion part 3 It is connected to the protruding terminals 11a and 11b.

As shown in FIG. 9, the punching blade 4 is integrally formed of stainless steel, and the tip of a rotating jig (not shown) is attached to the rotating portion 4a having a screw formed on the outer peripheral surface thereof. A hexagonal hole 4b to be fitted is provided, and a blade portion 4c is integrally formed at a position below the rotating portion 4a facing the base tube 2. The blade portion 4c is formed in a thin tubular shape,
The blade surface 4d at the tip is linearly formed so as to be circular in the same plane.

When the main pipe 2 and the branch pipe 7 are connected by the branch joint 1, first, the fusion-bonding surface of the main pipe 2 with the branch joint 1 is cut with a planer, and the branch joint 1 is cut.
The inner surface of the main tube fusion-bonding part 3 in Fig. 2 is cleaned, and after that, both are clamped by a clamping jig (not shown) with the branch joint 1 placed on the main tube 2, and the heating wire 10 is energized. The branch joint 1 is heat-sealed to the base pipe 2. And the branch joint 1
The branch portion 8 and the branch pipe 7 are fused via the socket 6.

Although not shown, a heating wire is also provided on the inner surface of the socket 6, and the terminals 6a and 6b of the socket 6 are provided.
By energizing the heating wire 10 from the above, thermal fusion is performed in the same manner as fusion with the main tube 2.

After this, after inspecting the fusion-bonded portion and confirming the airtightness and the like, the punching operation is performed by the punching blade 4. That is, the cap body 9 is removed, the rotating jig is set on the body portion 5 of the branch joint 1, the tip of the rotating jig is fitted into the hexagonal hole 4b of the punching tool 4, and then the rotating jig is used. By rotating the tool with a ratchet wrench etc.,
The main pipe 2 while rotating the punching tool 4 about the vertical axis x
It is gradually lowered to the side and the branch position portion of the base pipe 2 is cut by the blade portion 4c (see the phantom line portions in FIGS. 5 and 6).

After the cutting, the rotating jig is rotated in the opposite direction so that the punching tool 4 is at its original position (the position where the upper end surface of the punching tool 4 substantially coincides with the upper surface of the body portion 5 (see FIGS. (See Figure 7)))
Up. At this time, the cut portion of the main tube 2 that has been cut is press-fitted into the blade portion 4c of the punching blade 4 and is moved upward together with the punching blade 4 in this state. As a result, the base pipe 2 is perforated, and the one blocking the space between the base pipe 2 and the branch pipe 7 is removed, so that the base pipe 2 and the branch pipe 7 are connected via the branch joint 1.

After the boring tool 4 is moved up to its original position, the cap body 9 is put on the body portion 5 and tightened. At this time, the O-ring 15 fitted on the upper part of the body 5
Alternatively, the O-ring 16 provided between the body portion 5 and the cap body 9 ensures the sealing property.

By using this branch joint 1, not only the main pipe 2 through which gas has not yet flowed but also the main pipe 2 through which gas has already passed can be branched.

[0012]

However, according to the branch joint 1 having the above-mentioned conventional structure, the punching tool 4 is used in the drilling operation.
By rotating the tool with a rotating jig,
Since the main pipe 2 is threaded in a state where the entire circumference of the blade surface 4d of the above is in contact with the main pipe 2, a large frictional force in the circumferential direction is constantly applied and the blade 4 for drilling must be rotated with a very large force. , Was putting a heavy burden on the workers.

FIG. 1 shows a punching tool 4 for coping with this.
As shown in FIG. 0, it is conceivable that the blade surface 4e has a saw-tooth shape, and according to this configuration, the base tube 2 is kept in a state where only the tip of the saw blade-shaped blade surface 4e is in contact with the base tube 2. Since the cutting is performed, the frictional force in the circumferential direction is reduced, and it is only necessary to rotate the punching blade 4 with a relatively small force. However, in this case, chips are generated when the base pipe 2 is cut, and the chips enter the base pipe 2.

The present invention solves the above-mentioned problems, and it is possible to perform a piercing operation at the time of branching without requiring a large force, and it is possible for cutting chips to enter the main pipe during the piercing operation. An object of the present invention is to provide a blade for piercing a branch joint that does not exist.

[0015]

In order to solve the above-mentioned problems, the present invention is provided in a tubular body portion standing upright from a resin-made base tube fusion portion, and the main tube fusion portion is fused. A blade for piercing a branch joint that pierces a main pipe by screwing it into the main pipe to be attached so that the main pipe-side passage communicates with the branch-side passage, and the blade surface at the tip of the blade portion is screwed. It is formed in a wave shape with respect to the direction.

[0016]

With the above structure, the blade surface at the tip of the blade portion is formed in a wave shape with respect to the screw-in direction, and when the rotating member is rotated, the protruding side of the wave-shaped blade surface is spaced at regular intervals. Since it repeatedly bites into the original pipe, the frictional force applied to the circumferential direction is small, and it is possible to punch while rotating the punching blade with a relatively small force. Further, since the blade surface has a wavy shape and is formed by a gently curved surface, no cutting chips are generated and the cutting chips do not enter the main tube.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Since the structure of the branch joint other than the blade portion in the punching blade is the same as the conventional structure, the same reference numerals are given to these members and the description thereof will be omitted.

As shown in FIG. 1, the blade portion 22 of the perforating blade 21 is made of stainless steel or the like and is the rotating portion 4a as in the conventional case.
The blade surface 23 at the tip thereof is formed as a corrugated thin blade with respect to the screwing direction (downward direction in FIG. 1) of the punching blade 21 unlike the conventional case. There is.

As shown in the enlarged view of FIG.
A protrusion 24 that protrudes toward the inner peripheral side is formed on the inner periphery of the tip end of No. 2, and the tip end of the blade portion 22 to the top of the protrusion 24 is inclined at a small angle, while upward from the top of the protrusion 24. Is inclined at a relatively large angle, and a small uneven surface 25 such as a screw is formed.

Next, the operation of the above-described construction during the punching operation will be described. When the tip of the jig for rotation is inserted into the hexagonal hole 4b of the rotating portion 4a and the tip is rotated in a predetermined direction by a ratchet wrench or the like, the rotating portion 4a rotates along the threaded portion on the inner surface of the body portion 5. While moving to the original pipe 2 side (direction a) (see FIG. 3). Then, the blade portion 22 rotates integrally with the rotating portion 4a and bites into the main tube 2,
In this case, since the blade surface 23 at the tip of the blade portion 22 is formed in a corrugated shape in the screwing direction, the corrugated blade surface 2
The portion of the protrusion 3 projecting to the side of the base pipe 2 repeatedly bites into the base pipe 2 at regular intervals. Therefore, the frictional force in the circumferential direction is smaller than that of the conventional drilling tool, and the drilling tool 21 can be drilled while rotating with a relatively small force. Further, since the blade surface 23 has a corrugated shape and is formed with a gently curved surface, chips are not generated during perforation, and the chips do not enter the main tube 2.

After the cutting, the rotating jig is rotated in the opposite direction, and as shown in FIG. 3 and FIG.
Is moved up to the original position (the position where the upper end surface of the punching tool 21 substantially coincides with the upper surface of the body portion 5). At this time, the cut target portion Y (see FIGS. 1 and 2) of the source pipe 2 is press-fitted into the blade portion 22 of the punching blade 21, and the uneven surface 25 formed on the blade portion 22 and The to-be-cut portion Y cut by the projection 24 is locked, and in this state, the punching tool 2
Moved up with 1. Therefore, after this, even if the branch joint 1 is cooled to the external temperature and the cut portion Y is thermally contracted, the cut portion Y is locked by the uneven surface 25 of the blade portion 22 and the projection 24, and the blade portion is cut. It is prevented from dropping from 22.

In the above-mentioned embodiment, the case of applying the same to the conventional buried gas pipe has been described, but it is needless to say that the present invention can also be applied to a water pipe made of a resin having flexibility. .

[0023]

As described above, according to the present invention, since the blade surface at the tip of the blade portion is formed in a corrugated shape with respect to the screwing direction, the branching joint can be drilled without requiring much force. Therefore, the working efficiency can be improved, and since the cutting powder will not be generated and the cutting powder will not enter the main tube, the reliability as a drilling blade is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a punching tool for a branch joint according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part of a blade portion of the same punching tool.

FIG. 3 is a sectional view of a branch joint using the same punching tool.

FIG. 4 is a cross-sectional view of a branch joint using the same punching tool.

FIG. 5 is a perspective view of a branch joint.

6 is a sectional view taken along line AA of FIG.

7 is a sectional view taken along line BB of FIG.

FIG. 8 is a bottom view of a conventional branch joint as viewed from below.

FIG. 9 is a cross-sectional view of a conventional blade for piercing a branch joint.

FIG. 10 is a sectional view of another conventional blade for piercing a branch joint.

[Explanation of symbols]

 2-way pipe 4a Rotating part 5 Body part 21 Cutting tool for drilling 22 Blade part 23 Blade surface 24 Projection part 25 Uneven surface

Claims (1)

[Claims] 1. A blade portion which is internally mounted in a tubular body portion erected from a resin-made base tube fusion-bonding portion, and is screwed into the main tube-side where the base-tube fusion-bonding portion is fused. A piercing blade of a branch joint for piercing a main pipe to communicate the main pipe-side passage with the branch-side passage, wherein the blade surface of the tip of the blade portion is formed in a corrugated shape in the screwing direction. Tool for drilling joints.