JPH10180538A - Cutting tool and cutting assistant tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a rotary blade from contacting with an inside pipe so as to injure it without paying attention in particular by an operator by providing guard members preventing the rotary blade advancing while cutting the pipe wall of an outside pipe from contacting with the inside pipe on a cutter main body. SOLUTION: The wall portion of a first pipe 200 cut off along the lengthwise direction by a pipe slitter is inserted between a guard member 8 and a second guard member 5, a rotary blade 50 is approached to one end face 200a, the rotary blade 50 is cuttingly advanced in the circumferential direction of the first pipe 200 without injuring a second pipe 300 inserted inside the first pipe 200 while being rotationally driven, and the first pipe 200 is at first divided into two. Next, similar cutting is executed again on the position where the rotary blade is moved by a fixed distance along the lengthwise direction on the first pipe 200, and a cut piece of a fixed dimension is cut off from the first pipe 200.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting device for a conduit, and more particularly, to a tube wall portion previously cut along a longitudinal direction of a first conduit, and an end face formed by the cutting. A cutting tool capable of cutting along the circumferential direction of the first conduit and with the second conduit inserted inside the first conduit, or
A pipe wall portion cut in advance along the longitudinal direction of the conduit is connected to a second portion along the circumferential direction of the first conduit and inside the first conduit, starting from the end face formed by the cutting. The present invention relates to a cutting aid for attaching to a cutter provided with a rotary blade capable of cutting while a conduit is inserted.

[0002]

2. Description of the Related Art Conventionally, as a cutting technique of this kind, a cutter provided with a rotary blade is used as a cutting device, and the cutting device is pressed in the circumferential direction of the first conduit while pressing the rotary blade against the outer surface of the first conduit. There is known a method of moving along a vehicle to make a cut.

[0003]

In the above-described conventional cutting apparatus, when performing the cutting, the cutting operator performs the cutting with care as much as possible so that the rotary blade does not contact the second conduit. However, in reality, there is a concern that the rotating blade may come into contact with the second conduit and damage the latter regardless of the operator's attention. SUMMARY OF THE INVENTION It is an object of the present invention, in view of the above-mentioned drawbacks found in the cutting device of the conventional structure illustrated above, that the rotating blade contacts and damages the second conduit without any special attention of the operator. Attaching to a cutting tool having no cutting tool or a cutter provided with a rotating blade provides a cutting aid that does not cause the rotating blade to contact and damage the second conduit without any special care by an operator. Is to do.

[0004]

[Means for Solving the Problems]

<1> In order to achieve the above object, a cutting tool according to the present invention includes a cutter body 100 having a rotary blade 50 capable of cutting through a pipe wall of a first conduit 200. Guard member 8 for preventing contact with second conduit 300
Are provided on the cutter body 100.

[Effects of the Invention] Due to the above-mentioned features,
In the cutting tool according to the present invention, since the rotating blade is reliably prevented from coming into contact with the second conduit, the rotating blade can be brought into contact with the second conduit without any special attention by an operator. There is no danger of damaging this, and therefore, a unique effect of increasing the efficiency of the cutting operation is produced. further,
Since the cutting is performed in a state where the guard member is inserted into the inner surface of the first conduit, the rotary blade of the cutting tool keeps the first blade as long as the cutting tool continues to move while moving along the peripheral surface of the first conduit. This produces an effect that the state of contact with the conduit is automatically maintained. In other words, it is possible to prevent the rotary blade from being separated from the first conduit so as not to be cut, so that a unique effect that the cutting operation can be performed more easily occurs.

In addition, with respect to the above-mentioned feature, the rotary blade 50 is provided with the guard member 8 positioned between the pipe wall portion of the first conduit 200 and the second conduit 300 as in the second aspect of the present invention.
It is more convenient to add a feature that a second guard member 6 for keeping the distance from the rotation axis to the first conduit 200 at a predetermined distance or more is provided. When implemented in such a form, the angle of attack that the rotary blade makes with the tube wall portion of the first conduit, or the cut length of the rotary blade with respect to the already cut surface of the tube wall portion of the first conduit is appropriate for the rotary blade. This is advantageous because the pipe wall of the first conduit is sandwiched between the guard member and the second guard member, so that the cutting tool itself is kept in a proper range and thus high cutting efficiency is maintained. Since the attitude with respect to the pipe wall is also fixed, the cutting tool is easily moved naturally along the outer peripheral surface of the pipe wall of the first conduit, so that the cutting operation is easier and convenient.
Furthermore, unique effects, such as being advantageous because it is possible to prevent cutting chips generated from the pipe wall of the first conduit by the cutting and fragments or the like in the event that the rotary blade is chipped from flying directly toward the operator as much as possible, are produced. .

<2> In order to achieve the above object, the cutting aid according to the present invention is characterized by having a guard member 8 for preventing the rotary blade 50 from contacting the second conduit 300.

[Effects of the Invention] Due to the above-mentioned features,
In the cutting tool according to the present invention, since the rotating blade is reliably prevented from coming into contact with the second conduit, the rotating blade can be brought into contact with the second conduit without any special attention by an operator. There is no danger of damaging this, and therefore, a unique effect of increasing the efficiency of the cutting operation is produced. further,
Since the cutting is performed in a state where the guard member is inserted into the inner surface side of the first conduit, the rotary blade of the cutting tool is moved to the first position as long as the cutting tool continues to move along the outer periphery of the first conduit with the cutting. The state of contact with the conduit is maintained, in other words, the rotating blade is prevented from being separated from the first conduit and cannot be cut, so that a unique effect that the cutting operation can be performed more easily occurs.

According to the fourth aspect of the present invention, in the state where the guard member 8 is located between the pipe wall portion of the first conduit 200 and the second conduit 300, the rotary blade 50 is provided.
It is more convenient to add a feature that a second guard member 6 for keeping the distance from the rotation axis to the first conduit 200 at a predetermined distance or more is provided. When implemented in such a form, the angle of attack that the rotary blade makes with the tube wall portion of the first conduit, or the cut length of the rotary blade with respect to the already cut surface of the tube wall portion of the first conduit is appropriate for the rotary blade. This is advantageous because the pipe wall of the first conduit is sandwiched between the guard member and the second guard member, so that the cutting tool itself is kept in a proper range and thus high cutting efficiency is maintained. Since the attitude with respect to the pipe wall is also fixed, the cutting tool is easily moved naturally along the outer peripheral surface of the pipe wall of the first conduit, so that the cutting operation is easier and convenient.
Furthermore, a unique effect such as being advantageous because it is possible to minimize the possibility that chips generated from the pipe wall of the first conduit due to the cutting and fragments or the like in the event that the rotary blade is chipped fly toward the operator as much as possible is obtained. .

[0010] In the description of the above-mentioned features, reference numerals are used for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, first, a first conduit is first longitudinally cut by a pipe splitter (an example of a structure is shown in FIG. 8) along its longitudinal direction. A new second conduit is drawn into the inner space of the first conduit and inserted thereinto, and then at two places of the longitudinally cut tube wall portion of the first conduit (two places separated in the longitudinal direction of the first conduit). Is cut by the cutting tool according to the present invention along the circumferential direction of the first conduit starting from the end face formed by the vertical cutting, and finally, the first conduit sandwiched between the two cut locations. An embodiment of the present invention will be described by taking as an example a series of operations of providing a branch pipe in the second conduit portion exposed after removing the fragment.

(Structure of Cutting Tool and Cutting Aid) FIG. 1
1 and 2 show the appearance of the cutting tool 1 according to the present invention. As can be understood from FIGS. 1 and 2, the cutting aid 2 is attached to a cutter 100 having a rotary blade as illustrated in FIG. And the cutting tool 1 are obtained. Further, as shown in FIGS. 1 to 4, the cutting aid 2 has a box-shaped auxiliary tool main body 4 having a generally trapezoidal shape in a side view and an open top.
The bottom of the assisting device body 4, that is, the short side of the trapezoid is almost closed by a guard member 5 having an arc shape in a side view. As shown in FIGS.
Is provided with a slit-shaped opening 6. A connecting plate 7 extends downward from a lower rear portion of the assisting device main body 4, and a second guard member 8 further extends from a distal end of the connecting plate 7.
The guard member 8 has an arc shape smaller in diameter than the guard member 5 and extends concentrically with the guard member 5. Further, as best shown in FIG. 3, front attachment holes 9, 9 are formed in the front end of the auxiliary tool main body 4 in a horizontal and horizontal direction.
At the rear end is a rear mounting plate 10 in which a rear mounting hole 10a is opened in the horizontal front-rear direction in FIGS.

As shown best in FIGS. 1 and 7, the cutter 100 includes a cutter body 20, an electric motor section 30 connected to the cutter body 20, and an operating section extending upward from the electric motor section 30 in FIG. A handle 40 is provided. The handle 40 is provided with a trigger switch 42 for turning on / off the electric motor, a switch lock 44, and the like, and further connected to a covered conductor 46 for supplying an alternating current. A rotary shaft 32 extends horizontally from the electric motor unit 30 through the cutter body 20, and a metal rotary blade 50 in which diamond particles are embedded in the cutting blade portion is fixed to the rotary shaft 32 so as to be integrally rotatable. I have. Also, the rotary blade 5 is provided on the cutter body 20.
A cover 22 is provided to cover 0 from above. Further, a fixing through hole 24 is formed at the front end of the cutter body 20, and a fixing bolt 26 extends from the rear end of the cutter body 20.

The cutting aid 2 and the cutter 100 are connected to the fixing through hole 24 of the cutter body 20 and the fixing bolt 2.
6, and by using the front mounting holes 9, 9 and the rear mounting hole 10a of the cutting auxiliary tool 2, it is fixed to the state shown in FIG. That is, first, the rotary blade 50 is placed in the space in the auxiliary tool main body 4, and the rotary blade 50 is further projected downward from the slit-shaped opening 6, and the cutter main body is inserted into the rear mounting hole 10 a of the cutting auxiliary tool 2. 20
Of the cutter body 20 and then the cutter body 20
After the bolt 11 is passed through the through hole 24 for fixing and the front mounting holes 9, 9 of the cutting aid 2, the bolt 11 is fixed with the nut 12, and finally, the fixing bolt 26. Screw the wing nut 13 to the rear mounting plate 1
1 is fixed to the cutter body 20, the cutting tool 1 of FIGS. 1 and 2 is formed. As shown in FIG. 2, in the cutting tool 1, the rotation locus of the rotary blade 50 protruding from the slit-shaped opening 6 of the guard member 5 is positioned between the guard member 5 and the second guard member 8. It is configured to be.
The connecting plate 7 and the rotary blade 50 are located in the same vertical plane, and the thickness of the connecting plate 7 is set to be substantially smaller than that of the rotary blade 50. Can enter the groove to be cut formed by the rotary blade 50 without resistance.

(Process of Pipe Cutting Operation) <First Cutting Step> Here, a so-called preliminary stage of cutting along the longitudinal direction of the first pipe will be described. FIG.
Cuts (longitudinal cut) the iron gas conduit 200 (an example of the first conduit) along the longitudinal direction using the pipe splitter 400, and cuts and substantially expands the diameter almost simultaneously with the cutting. A process of drawing a polyethylene gas conduit 300 (an example of a second conduit) into the gas conduit 200 is shown. The pipe splitter 400 is an apparatus having a long bullet body 70 made of steel, and has guide rollers 72, 72,. . Are provided rotatably, and the cutting rotary cutters 74, 74,. . Are provided rotatably. However, the rotary cutters 74 and 7
4,. . The protrusion dimension of the blade gradually increases from the front to the rear of the pipe splitter 400. The front end of the bullet body 70 has an outer diameter smaller than the inner diameter of the gas conduit 200, and a female screw (or hook) 79 capable of connecting a rod or wire is formed at the foremost end. Also,
At the rear part of the bullet body 70, there is an enlarged diameter part 76 (in which neither a guide roller nor a rotary cutter is provided) that gradually increases in diameter toward the rear, and at the end, a gas pipe made of polyethylene. A connecting portion 78 capable of connecting the same is formed.

A gas conduit 3 made of polyethylene is connected to the connecting portion 78.
00, the front end of the pipe splitter 400 is inserted into the gas conduit 200, and then the pipe splitter 4
When the rod or wire connected to the female screw (or hook) 79 at the front end of the rotary cutter 74 is hydraulically pulled, the rotary cutters 74, 74,. . Cuts the gas conduit 200 along the longitudinal direction, and further, the pipe diameter is greatly expanded from the cut portion by the enlarged diameter portion 76. As a result, the gas conduit 200 is enlarged, and the polyethylene gas conduit is placed there. 300 is retracted.

<Second Cutting Step> FIG. 5A shows the first conduit 2 cut along the longitudinal direction by the first cutting step.
00 and a cross section of the second conduit 300 drawn therein. In the second cutting step, the pipe wall portion of the first conduit 200 cut in the first cutting step is placed in the circumferential direction of the first conduit 200 with the end face 200a of the first conduit 200 formed in the first step as a starting point. Cutting and cutting using the cutting tool 1 (i.e., cutting across the first conduit 200) so as not to damage the second conduit 300 inserted along and inside the first conduit 200. ). First, as shown in FIG. 5-B, the second guard member 8 of the cutting tool 1 is
Inserted into the gap between the first conduit 200 and the second conduit 300 from between the end faces 200a, 200a of the conduit 200, in other words,
The tube wall portion of the first conduit 200 is inserted between the guard member 8 and the second guard member 5, and the rotary blade 50 is connected to one end face 200a.
, The rotary blade 50 is driven to rotate and cut in the circumferential direction of the first conduit 200 (the direction of the arrow in FIG. 5B), and the first conduit 200 is first divided into two.

<Third Cutting Step> The same cutting as in the second cutting step is performed at a position shifted by a length L along the longitudinal direction on the first conduit 200 from the position where the cutting was performed in the second cutting step. The operation is performed again, and the piece 200 ′ having the length L cut off from the first conduit 200 is removed, and all the cutting operations are completed (see FIG. 6).

<Branch Pipe Forming Step> A necessary portion of the surface of the portion 300 ′ exposed in the previous step of the second conduit 300 is cleaned and scraped, and then cleaned with alcohol or the like. The formation of the branch pipe (not shown) is completed by electro-welding the saddle joint 400 in which the heat wire is embedded and further piercing the second conduit 300 in accordance with the through hole of the fused saddle joint 400.

[Alternative Embodiment] As the rotary blade 50, a resin-bonded blade containing an abrasive such as silicon carbide can of course be used.

[Brief description of the drawings]

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

FIG. 2 is a side view of the cutting tool of FIG. 1;

FIG. 3 is a side view showing a cutting aid according to the present invention.

FIG. 4 is a front sectional view showing the cutting tool of FIG. 1 and first and second conduits;

FIG. 5 is a schematic view showing a step of cutting a first conduit by the cutting tool of FIG. 1;

FIG. 6 is a schematic view showing a step of forming a branch pipe in a second conduit.

FIG. 7 is a perspective view showing a cutter used for the cutting tool in FIG. 1;

FIG. 8 is a perspective view showing a pipe splitter.

[Explanation of symbols]

 5 second guard member 8 guard member 50 rotary blade 100 cutter 200 first conduit 300 second conduit

Claims (4)

[Claims] 1. A pipe wall portion cut in advance along a longitudinal direction of a first conduit, starting from an end face formed by the cutting, along a circumferential direction of the first conduit, and
What is claimed is: 1. A cutting tool capable of cutting through a second conduit inserted inside the first conduit, comprising a rotary blade capable of cutting through a pipe wall of the first conduit. And a guard member provided on the cutter body for preventing the rotary blade from contacting the second conduit. 2. A distance from the axis of rotation of the rotary blade to the first conduit in a state where the guard member is located between the pipe wall portion of the first conduit and the second conduit. The cutting tool according to claim 1, further comprising a second guard member for maintaining the cutting tool. 3. A pipe wall portion cut in advance along the longitudinal direction of the first conduit, starting from an end face formed by the cutting, along a circumferential direction of the first conduit, and
A cutting aid for attaching to a cutter having a rotary blade capable of cutting in a state where a second conduit is inserted inside the first conduit, wherein the rotary blade contacts the second conduit. A cutting aid having a guard member for preventing cutting. 4. A distance from the axis of rotation of the rotary blade to the first conduit in a state where the guard member is located between the pipe wall portion of the first conduit and the second conduit. 4. The cutting aid according to claim 3, further comprising a second guard member for keeping the cutting force.