JPH0825127A - Pipe cutting machine - Google Patents

Abstract

PURPOSE:To provide a pipe cutting machine by which a pipe line for flammable fluid such as a gas conduit can be quickly and safely cut without contaminating a working environment. CONSTITUTION:A cutting machine main body 1, which rotationally drives a diamond cutter so as to sequently cut a pipe P to be cut around its whole circumference while circularly moving along the outer circumference of the pipe P to be cut, is provided with a cover member 11, which covers the diamond cutter 6 so that its circumference part faces the outer circumferential face of the pipe P to be cut, and a nozzle 12, which jets inert gas toward the cutting part of the diamond cutter 6 inside the cover member 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe cutting machine which can be attached to a pipe having a relatively large diameter and can cut the pipe on site, and more specifically, a pipeline of a flammable fluid can be cut safely and quickly. To an improved pipe cutting machine.

[0002]

2. Description of the Related Art As a pipe cutting machine for cutting a pipe having a relatively large diameter up to a diameter of about 1,500 mm, Japanese Patent Publication No.
Those described in Japanese Patent Publication No. 6-23727, Japanese Examined Patent Publication No. 59-9288, etc. are conventionally known. This pipe cutting machine is equipped with a cutter, and a cutting machine body that rotates at a reduced speed via a clutch mechanism and a speed reduction mechanism, and a belt-type self-propelled machine that is decelerated by the clutch mechanism and the speed reduction mechanism of the cutting machine body. It is equipped with a device, a belt type self-propelled device, and a chain with rollers that attach the cutting machine body to the outer circumference of the pipe to be cut, and the rotational power of the engine, hydraulic motor, etc. is input to the cutting machine body via a flexible shaft. By doing so, the main body of the cutting machine circulates along the outer periphery of the pipe to be cut by the belt type self-propelled device, and sequentially cuts the pipe to be cut over the entire circumference by the cutter.

[0003] Such a pipe cutting machine is small and lightweight, is very easy to handle, and above all, can cut existing buried pipes in the field. Therefore, it is necessary to cut existing gas pipes made of steel pipes or cast iron pipes. It is also used frequently.

[0004]

By the way, when cutting an existing gas conduit by using the above-mentioned pipe cutting machine, that is, when cutting a gas conduit made of steel or cast iron by a disk-shaped diamond cutter or the like. A spark is likely to be generated, and a large amount of spark is generated when the rotation speed of the cutter is increased, and there is a risk that the flammable gas inside the gas conduit is ignited. Therefore, generally, the rotation speed of the cutter is set low so that sparks are not generated, or water is poured and oiled in the vicinity of the cut portion of the cutter to prevent sparks by the cooling action. Therefore, there is a problem that the cutting work of the gas conduit takes a long time and the cooling water and the cooling oil are scattered to pollute the surrounding work environment.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pipe cutting machine capable of cutting a flammable fluid pipeline or the like quickly and safely without polluting the working environment.

[0006]

To this end, the present invention is provided with a cutting machine body for sequentially cutting the pipe to be cut by rotating the cutter while rotating the pipe along the outer periphery of the pipe to be cut. In the pipe cutting machine, the cutting machine includes a cover member that covers the cutter and has a peripheral edge facing the outer peripheral surface of the pipe to be cut, and a nozzle that ejects an inert gas toward a cut portion of the cutter in the cover member. It is attached to the main body.

Further, the nozzle is also mounted on the main body of the cutting machine so that the jetting direction of the inert gas can be adjusted.

Here, the material of the cover member is not particularly limited, but if the cover member is made of a flexible material such as various synthetic rubbers or an appropriate soft synthetic resin, the peripheral portion thereof is a pipe to be cut. It is possible to improve the sealing property by elastically contacting the outer peripheral surface of the. On the other hand, when the cover member is made of various metals or rigid synthetic resin as a material having rigidity,
It is preferable to support the cover member via an appropriate elastic member such as a spring, and thereby the peripheral portion of the cover member can be elastically contacted with the outer peripheral surface of the pipe to be cut.

The inert gas ejected from the nozzle is not particularly limited, and nitrogen gas or carbon dioxide gas can be used.

[0010]

In the pipe cutting machine according to the present invention which employs such means, the cutting machine main body circulates along the outer periphery of the pipe to be cut and rotationally drives the cutter, whereby the entire circumference of the pipe to be cut is sequentially cut by the cutter. Be disconnected.

Here, during the cutting work of the pipe to be cut by the cutter, the inactive gas ejected from the nozzle is intensively blown to the cut portion of the cutter, thereby cooling the cut portion of the cutter and the pipe to be cut. . Further, the inside of the cover member that covers the cutter is filled with an inert gas and becomes an inactive region. Therefore, no sparks are generated even if the cutter is rotated at high speed, and even if the flammable fluid leaks when cutting the pipeline of the flammable fluid such as city gas or oil, it may ignite and explode. Nor.

Most of the cutting powder of the pipe to be cut by the cutter is discharged inside the pipe to be cut by the inert gas which is intensively ejected from the nozzle, and the remaining cutting powder is also discharged to the surroundings by the cover member. Since the scattering is prevented and the inert gas only flows out to the outside of the cover member, the periphery of the pipe to be cut is not contaminated.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the accompanying drawings. As shown in FIG. 1, a pipe cutting machine according to an embodiment includes a cutting machine body 1, a support arm 2, a belt type self-propelled device 3, a roller chain 4, etc., which are mounted along the outer peripheral surface of a pipe P to be cut. In the main body 1 of the cutting machine, a flexible shaft (not shown) in a power transmission tube 5 is inserted from a drive engine or hydraulic pump (not shown) installed in the vicinity of the pipe P to be cut. Rotational power is transmitted.

The cutting machine body 1 includes a power transmission tube 5
2 has a centrifugal clutch capable of interrupting rotational power input via a flexible shaft therein and an decelerator mechanism for reducing rotational power input via the centrifugal clutch, which is incorporated in the casing 1a, and is shown in FIG. As described above, the cutter rotation shaft 1b and the wheel drive shaft 1c that are decelerated by the deceleration mechanism project from the casing 1a.

The cutter rotating shaft 1b is located on the rear side (lower side in FIG. 2) of the cutting machine main body 1 in the traveling direction, and is located in the casing 1.
The disk-shaped diamond cutter 6 is detachably fixed to the cutter rotation shaft 1b, which projects from the boss 1d on one side (a right side in FIG. 2) of a. The wheel drive shaft 1c is located on the front side (upper side in FIG. 2) in the traveling direction of the cutting machine body 1 and protrudes on both sides of the casing 1a, and V pulleys 3a, 3a as drive wheels are provided at both ends thereof.
Has been fixed.

The support arms 2 are disposed on both the left and right sides of the casing 1a of the cutting machine body 1, one end of which is pivotally mounted around the wheel drive shaft 1c, and the other end of which is the cutting machine body 1. It is a pair of left and right facing the backward direction (lower side in FIG. 2) in the traveling direction, and its side surface shape is a semi-circular shape that bulges upward and straddles the boss portion 1d of the casing 1a and the like (see FIG. 1). . And this pair of left and right support arms 2, 2
The other end portions of are connected to each other via a connecting shaft 7, and a chain connecting fitting 9 is attached to the connecting shaft 7 together with a pair of left and right rolling wheels 8 rolling on the outer peripheral surface of the pipe P to be cut. There is.

The chain connecting fitting 9 is formed by connecting the other ends of a pair of left and right connecting arms 9a, 9a pivotally attached to the connecting shaft 7 with two connecting shafts 9b, 9c. A pair of left and right rolling wheels 9d, 9d capable of rolling on the outer peripheral surface of the pipe P to be cut are attached to the connecting shaft 9b, and similar rolling wheels 9e, 9e are also attached to the connecting shaft 9c.

Here, the cutting machine main body 1 has a pair of left and right support arms 2 and 2, and a wheel drive shaft 1c on the front end side thereof.
The cutter rotary shaft 1b on the rear end side is swingable up and down, and the diamond cutter 6 is cut into the pipe P to be cut by swinging the cutter rotary shaft 1b downward. Therefore, in order to set the cutting amount of the diamond cutter 6 according to the thickness of the pipe P to be cut, a screw is provided between the rear part of the pair of left and right support arms 2 and 2 and the rear part of the casing 1a of the cutting machine body 1. A cut-and-fixed cutting depth setting device 17 is provided.

As shown in FIG. 3, a support shaft 3b is arranged in front of the cutting machine body 1 in the traveling direction (upper side in FIG. 3), and the V pulleys 3a, 3 are provided at both ends of the support shaft 3b.
A pair of left and right V pulleys 3c having the same diameter corresponding to a are rotatably mounted. And this V pulley 3c,
3c and the V pulleys 3a, 3a, a pair of left and right V belts 3 whose lower surface frictionally contacts the outer periphery of the pipe P to be cut.
The belt type self-propelled device 3 is wound by winding d and 3d.
Is configured.

The roller-equipped chain 4 has a predetermined length and a predetermined width which are wound around the pipe P to be cut, and each connecting pin 4a extending in the width direction has the pipe P to be cut. A pair of left and right rollers 4 that can roll on the outer peripheral surface
b and 4b are rotatably mounted, and a pair of left and right hook pieces 4c and 4c are fitted and mounted on the connecting pin 4a at one end. The chain 4 with rollers is wound around the outer peripheral surface of the pipe P to be cut with the hook pieces 4c, 4c at one end engaged and connected to the connecting shaft 9b of the chain connecting fitting 9, and the other end has a length. It is connected to the support shaft 3b of the belt type self-propelled device 3 via an adjusting metal fitting 10.

The length adjusting fitting 10 includes a connecting block 10b with a bolt insertion hole 10a fitted and attached to a connecting pin 4a at the other end of the roller-equipped chain 4, and a support shaft 3b.
Connection block 10 with screw 10c for fitting and mounting to
d and the female screw 1 through the bolt insertion hole 10a.
0c and a connecting bolt 10e screwed together, and by adjusting the screwing amount of the connecting bolt 10e, the other end of the roller-equipped chain 4 is connected to the support shaft 3b in a freely adjustable length.

Here, as shown in FIG. 2, the cutting machine body 1 has a cover member 11 for covering the diamond cutter 6.
Also, a nozzle 12 for ejecting an inert gas toward the cut portion of the diamond cutter 6 is attached.

The cover member 11 is integrally formed of a flexible synthetic rubber or synthetic resin in the shape shown in FIG. 4, and has a diameter and a thickness capable of covering the periphery of the diamond cutter 6 with a margin. A hollow circular main body 11a and a pipe P to be cut on a part of the outer circumference of the main body 11a.
A main body 1a having a circular arc-shaped peripheral edge portion 11b along the outer peripheral surface of the main body 11a, and a mounting cylinder portion 11c protruding from the central portion of one surface of the main body 11a and capable of being fitted into the boss portion 1d of the cutting machine main body 1.
A cut-off portion 11d reaching the center of the peripheral edge portion 11b from the mounting cylinder portion 11c is formed on one surface of 1a, and an insertion hole 11e for the nozzle 12 is formed on the outer peripheral portion of the main body 11a.

In the cover member 11, the diamond cutter 6 is inserted into the opening surrounded by the peripheral portion 11b, the cut-off portion 11d is opened, and the mounting cylinder portion 11c is fitted to the boss portion 1d of the cutting machine body 1. And clip 13 around its circumference
It is attached to the cutting machine body 1 by tightening it with an appropriate tightening tool (see FIG. 2).

On the other hand, the nozzle 12 has a cock connected to the tip of a hose 14 extending through a regulator from a nitrogen gas cylinder (or carbon dioxide gas cylinder) (not shown) installed in the vicinity of the pipe P to be cut. It is fixed to the outer periphery of the boss portion 1d of the cutting machine body 1 via a free stay 15 shown in FIG.

The flexible stay 15 is formed by connecting three L-shaped brackets 15a, 15b, 15c to each other with screws, and the L-shaped bracket 15a on the tip side is fastened by tightening the screws at arbitrary mutual rotating positions. Can be three-dimensionally adjusted with respect to the L-shaped bracket 15c on the base end side. Therefore, in the universal stay 15, the L-shaped bracket 15c on the base end side is screwed and fixed to the outer periphery of the boss portion 1d, and the L-shaped bracket 15a on the tip end side.
The nozzle 12 penetrates through and is fixed by screwing a nut 16. The tip end of the nozzle 12 having a nitrogen gas ejection hole is seen inside through the insertion hole 11e of the cover member 11 and ejects the nitrogen gas toward the cut portion of the diamond cutter 6.

Next, the operation of the pipe cutting machine having the cutting machine body 1 as described above will be described. Figure 5
The cutting work of the to-be-cut pipe P (gas conduit which is a pipeline of city gas) using the pipe cutting machine of this example is shown, and the cutting machine main body 1 is the V belt 3d, 3d of the belt type self-propelled device 3. Rotates around the outer circumference of the pipe P to be cut by frictionally contacting the outer circumference of the pipe P to be cut, and at the same time, the diamond cutter 6 is rotationally driven to sequentially cut the pipe P to be cut.

Here, the nitrogen gas is intensively blown toward the cut portion of the diamond cutter 6 from the nozzle 12 in which the jet direction of the nitrogen gas is adjusted by the free stay 15, whereby the diamond cutter 6 and the pipe P to be cut P. The cutting point of is cooled. In addition, the nitrogen gas ejected from the nozzle 12 fills the cover member 11 so that the cover member 11 becomes an inactive region.

Therefore, even if the diamond cutter 6 is rotated at a high speed to improve the work efficiency, no spark is generated, and even if the city gas which is a combustible fluid in the pipe P to be cut is leaked, There is no danger of it catching fire and exploding.

Further, most of the cutting powder of the pipe P to be cut by the diamond cutter 6 is discharged inside the pipe P to be cut by the nitrogen gas intensively ejected from the nozzle 12, and the remaining cutting powder is also covered. 11 prevents scattering to the surroundings. Therefore, only harmless nitrogen gas flows out to the outside of the cover member 11, and the periphery of the pipe P to be cut is not contaminated.

[0031]

As described above, according to the present invention, during the cutting work of the pipe to be cut by the cutter, the inactive gas ejected from the nozzle is intensively blown to the cut portion of the cutter, whereby the cutter and the pipe to be cut are cut. The cutting point of is cooled. Further, the inside of the cover member that covers the cutter is filled with an inert gas and becomes an inactive region. Therefore, no sparks are generated even if the cutter is rotated at high speed, and even if the flammable fluid leaks when cutting the pipeline of the flammable fluid such as city gas or oil, it may ignite and explode. Nor.

Most of the cutting powder of the pipe to be cut by the cutter is discharged to the inside of the pipe to be cut by the inert gas intensively ejected from the nozzle, and the remaining cutting powder is also discharged to the surroundings by the cover member. Scattering is prevented. Therefore, only the inert gas flows out to the outside of the cover member, and the periphery of the pipe to be cut is not polluted.

Therefore, according to the present invention, a flammable fluid pipeline or the like can be quickly and safely cut without polluting the working environment.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall schematic structure of an embodiment of a pipe cutting machine according to the present invention.

FIG. 2 is an enlarged plan view of the cutting machine body showing a mounting state of the cover member and the nozzle in one embodiment.

FIG. 3 is a plan view of the vicinity of a cutting machine body in one embodiment.

FIG. 4 is an enlarged perspective view showing the outer appearance of a cover member in one embodiment.

FIG. 5 is an enlarged side view of an essential part showing the operation of the embodiment.

[Explanation of symbols]

 1 Cutting Machine Main Body 1a Casing 1b Cutter Rotation Shaft 1c Wheel Drive Shaft 1d Boss 2 Support Arm 3 Belt Type Self-propelled Device 3a, 3c V Pulley 3b Support Shaft 3d V Belt 4 Roller Chain 4a Connecting Pin 4b Roller 4c Hook Piece 5 Power transmission tube 6 Diamond cutter 7 Connecting shaft 8 Rolling wheel 9 Chain connecting fitting 9a Connecting arm 9b, 9c Connecting shaft 9d, 9e Rolling wheel 10 Length adjusting fitting 10a Bolt insertion hole 10b Connecting block 10c Female screw 10d Connecting block 10e Connecting bolt 11 Cover Member 11a Main Body 11b Peripheral Edge 11c Mounting Tube 11d Separation Part 11e Insertion Hole 12 Nozzle 13 Clip 14 Hose 15 Universal Stay 15a, 15b, 15c L-Shaped Bracket 16 Nut 17 Depth Setting Device

Claims (2)

[Claims] 1. A pipe cutting machine equipped with a cutting machine main body, which circulates along the outer circumference of a pipe to be cut and rotationally drives the cutter to sequentially cut the pipe to be cut over the entire circumference thereof, wherein the cutter covers a peripheral edge. A pipe cutting machine, characterized in that a cover member whose part faces the outer peripheral surface of the pipe to be cut and a nozzle for injecting an inert gas toward a cutting position of the cutter in the cover member are attached to the cutting machine body. . 2. The pipe cutting machine according to claim 1, wherein the nozzle is attached to the cutting machine body so that the direction of ejection of the inert gas can be adjusted.