JP2000107927A - Pipe cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable cutting edges to positively and stably abut against the inner periphery of a pipe to cut it at positions when the pipe is cut from inside by rotating cutters without using fire tools. SOLUTION: Plural grippers 3, 4 for performing pressing and fixing to the inner peripheral surface of an objective pipe to be cut are provided at the end of a shaft 2 inserted into the objective pipe 1 to be cut, radially and at a distance apart vertically (laterally). Plural cutters 5 which are rotatably driven around the shaft 2 and the cutting edges 13a to 13d of which are advanced and retracted by a cylinder or a jack, are provided at the shaft 2 radially at the positions between the grippers 3, 4 provided up and down (right and left) stages, and a rotation-driving power unit of the cutters 5 is also provided at the end of the shaft 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium diameter pipe cutting apparatus capable of cutting a steel pipe or the like as an underground pipe from the inside.

[0002]

2. Description of the Related Art Various apparatuses have been proposed and applied for cutting metal pipes such as steel pipes and copper pipes and synthetic resin pipes such as vinyl chloride pipes. Of these, when cutting from the outside of the pipe, cutting with a rotating cutting blade or cutting with a firearm such as a burner is also possible, but is there any obstacles such as pipes in the water or soil? Alternatively, in situations where it is difficult to use firearms, it is desirable to cut the tube from the inside.

[0003] Japanese Patent Application Laid-Open No. 60-71110 discloses an apparatus in which a drive shaft of a cutting blade is inserted into a pipe and the cutting blade is rotated by rotation of the drive shaft. It can be found in the official gazettes.

[0004]

As described above, in order to cut the pipe from the inside, in the case where the rotary drive shaft is inserted into the pipe to the cutting position, the power transmission mechanism becomes complicated, and a stable cutting posture is maintained. Therefore, even if a reaction force roller moving on the inner circumference of the pipe is provided, the instability cannot be eliminated. Moreover,
Even if the cutting blade is a disk-shaped rotary cutter, it is more difficult to make a cut by contacting the rotary cutter with the inner wall of the pipe in a pressed state as the rotary drive shaft becomes longer.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the disadvantages of the prior art, and to stably and reliably insert the cutting blade of the cutter into the inner circumference of the pipe when cutting the pipe from the inside with a rotating cutter without using a firearm. An object of the present invention is to provide a tube cutting device which can cut at an arbitrary position in contact with the tube.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention firstly provides a gripper for pressing and fixing an end of a shaft inserted into a pipe to be cut to an inner peripheral surface of the pipe to be cut. Are protruded radially and with an interval in the vertical (left and right) directions. At the position between the upper and lower (left and right) grippers, the shaft is driven to rotate around the shaft, and the cutting blade is A plurality of cutters moving forward and backward by a cylinder or a jack are provided radially, and a rotation drive power unit of the cutter is also provided at the shaft end.
An electric or hydraulic motor, an inner gear meshing with a gear provided on the motor is provided with a cutter; third, a gripper combines a telescopic gripper with a cylinder and a fixed gripper; fourth, a rotary drive power unit Is a telescopic sliding body such as a jack, which is connected to a cutter via a ratchet mechanism which rotates by the expansion and contraction of the telescopic sliding body.

According to the first aspect of the present invention, the shaft is a non-rotating member for positioning the cutter at a cutting position, and is inserted into the pipe to be cut. Is fixed to the inner peripheral surface of the pipe to be cut by a gripper projecting vertically (left and right) at intervals.
Then, the cutter between the grippers smoothly and reliably advances the cutting blade by the cylinder or the jack, rotates while abutting on the inner periphery of the pipe to be cut, and cuts from the inner peripheral surface side of the pipe to be cut. Since the upper and lower sides (front and rear) of the cutter are fixed by the gripper, the cutter can be rotated in a stable state.

According to the second aspect of the present invention, the rotary drive power unit is an electric or hydraulic motor, which can continuously rotate, and the gear provided in the electric motor and the inner gear mesh with the reduction gear. And the rotation of the electric or hydraulic motor can be transmitted to the cutter as rotation with a large torque.

According to the third aspect of the present invention, since the gripper includes the fixed gripper, the hydraulic or pneumatic control is simplified as compared with the case where all the grippers are telescopic grippers.

According to the fourth aspect of the present invention, the rotary drive power unit is a telescopic sliding member such as a jack and can be moved by hydraulic pressure, and a ratchet mechanism is replaced with a cutter instead of a large hydraulic motor. It can be rotated with a large torque in the direction.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional side view showing one embodiment of the pipe cutting apparatus of the present invention, FIG. 2 is a view taken along line AA of FIG. 1, FIG. 3 is a view taken along line BB of FIG. FIG. 5 is a view taken along the line DD in FIG. 5, and FIG.
It is a pipe to be cut such as a fume pipe or a synthetic resin pipe.

The pipe to be cut is, for example, a horizontally laid propulsion pipe buried in the ground by a propulsion method so as to connect a manhole as a pipeline, and the protective concrete is destroyed at a manhole remodeling work site. The remaining portion of the pipeline and the removal portion are cut off from the inside so that the remaining portion is not affected.

Further, a steel pipe sheet pile or the like may be a pipe to be cut, and in this case, it is a vertical pipe in the soil or underwater.

The pipe cutting device of the present invention presses and fixes the end of the non-rotating shaft 2 which is a member for positioning by inserting into the pipe 1 to be cut to the inner peripheral surface of the pipe 1 to be cut. It is provided with grippers 3 and 4 and a cutter 5 driven to rotate about the shaft 2.

Although the shaft 2 is not shown, the shaft 2 is connected to each other by a screw joint or the like to obtain a required length.
The piping 6 such as hydraulic or air and the wiring piping such as electricity can be formed in the pipe wall or can be built in the hollow interior.

The grippers 3 and 4 are provided at an interval above and below (right and left) with respect to the shaft 2, and as shown in FIGS. Protrusions were provided radially in the horizontal direction at appropriate intervals (three at 180 ° intervals in the illustrated example).

The grippers 3 and 4 are telescopic grippers 3a and 4a provided with a block-shaped pressing plate 8 at the tip of a piston rod 7a of a hydraulic (or air) cylinder 7.
And two fixed grippers 3b and 4b provided with a similar pressing plate 8 at the tip of a non-extended plate or bar.

The cutter 5 includes the upper and lower grippers 3,
As shown in FIG. 4, a hydraulic (or air) cylinder 12 is provided between a rotary body (rotary block) 11 rotatably provided on a shaft 2 via a bearing 10.
The hydraulic cylinder 12 is used as a holder, and a plurality of cutting blades 13a to 13d are attached to the tip of a piston rod 12a of the hydraulic cylinder 12 at appropriate intervals (four at 90 ° intervals in the illustrated example). Was attached by insertion.

A swivel is formed in the pipe 6 between the rotating body 11 and the shaft 2, and the four hydraulic cylinders 12 communicate with a hydraulic circuit equal to the shaft 2 side. When lubricating, the four piston rods 12a are pushed out at the same time, and the cutting blades 13a
単 13d is a single-acting cylinder that comes out.

As shown in FIG. 6, the four cutting blades 13a to 13d have a left cutting blade 13a and a right cutting blade 13a.
b, divided into cutting edges 13c and 13d for chamfering. FIG. 7 shows the case of a parting-type cutting tool of the cutting blades 13a and 13b, and FIG.
The shape in the case of 13c, 13d serious bite is shown.

The four cutting blades 13a to 13d are arranged such that the left cutting blade 13a and the right cutting blade 13b are arranged in a straight line, and the chamfering cutting blades 13c and 13d are arranged in a straight line. The cutting blades 13a and 13b are arranged so as to be linearly aligned with each other. Further, the positions of the cutting blades 13a to 13d are slightly shifted so as not to be on the extension line from the center of the shaft 2 including the center of the hydraulic cylinder 12, so that the tip angle of the hydraulic cylinder 12 or the tip angle of the piston rod 12a is cut. A situation in which the cutting blades 13a to 13d do not reach the inner peripheral surface of the target pipe 1 is prevented from occurring.

The mounting flange 9 of the lower gripper 4 is provided with a mounting flange 15 for providing an electric motor 14 or a hydraulic motor (not shown) also as a rotation driving power unit of the cutter 5. Rotary drive shaft 14a
Is engaged with an inner gear 17 fixed to the rotary body (rotary block) 11. The combination of the pinion gear 16 and the inner gear 17 constitutes a speed reducer. In this embodiment, the electric motor
Two 14 are installed, and these are connected to one inner gear 17.

The inner gear 17 is screwed to a drive wheel 19 rotatably provided on the shaft 2 with the bearing 10 interposed therebetween. The drive wheel 19 is screwed to the rotating body 11.

Next, the use and operation will be described.
Is determined, and the grippers 3 and 4 are inserted into the tube 1 to be cut in a contracted state. At the cutting position, the telescopic grippers 3a and 4a of the grippers 3 and 4 are extended by the cylinder 7, and are fixed to the fixed grippers 3b and 4b. Gripper 3 while taking reaction force
All the pressing plates 8 are pressed and fixed to the inner peripheral surface of the pipe 1 to be cut.

When the shaft 2 is inserted, a lid-like positioning support fitting 20 is wrapped around the end of the pipe 1 to be cut, and the shaft 2 is passed through the central hole 20a of the positioning support fitting 20. Then, the shaft 2 is cut into the pipe 1 to be cut.
At the center position of.

When the cylinder 12 of the cutter 5 is extended in this state, the cutting blades 13a to 13d come out all at once and join the inner peripheral surface of the pipe 1 to be cut.

When the electric motor 14 is energized, the electric power is transmitted from the pinion gear 16 to the inner gear 17, the drive wheel 19 rotates, the cutter 5 also rotates, and the cutting blades 13a to 13a.
At 13d, the pipe 1 to be cut is cut. The cutting blade 13
a to 13d are gradually pushed out when the cutter 5 rotates, but the left cutting is performed by the cutting blade 13a and the right cutting is performed by the cutting blade 13b. Cutting is performed efficiently so as not to receive much cutting resistance, and chamfering is performed with the cutting blades 13c and 13d.

When the cutters 5 do not move due to the cutting blades 13a to 13d being caught, the cylinder 12 can be rotated again by retracting the cutting blades 13a to 13d.

After the pipe 1 to be cut is cut, the cutting blades 13a to 13d of the cutter 5 are retracted, and if the telescopic grippers 3a and 4a of the grippers 3 and 4 are retracted, locking with the pipe 1 to be cut is performed. Is released, the shaft 2 can be pulled out.

FIGS. 9 to 11 show a second embodiment of the present invention, in which the rotary drive power unit of the cutter 5 is a jack 21 as a telescopic sliding body, and this jack 21 fixes a piston rod 21a. A claw 22 is provided outside the cylinder holder 21b via a claw holder 22a.

The two jacks 21 are arranged at intervals.
In the meantime, a ratchet gear 23 was provided, the pawl 22 was engaged with the ratchet gear 23, and the ratchet gear 23 was connected to the cutter 5.

In this way, the jack 21 is connected to the cutter 5 via the ratchet mechanism.
When the cylinder 21 is extended, the cylinder holder 21b is pushed out, the pawl 22 rotates the ratchet gear 23, and the cutter 5 is driven to rotate.

When the jack 21 is contracted, the pawl 22 is disengaged from the teeth of the ratchet gear 23 and returns to its original position, and the cutter 5 is rotated only in one direction by repeating the expansion and contraction of the jack 21.

The other mechanisms, such as fixing with a gripper and the protruding of the cutting blades 13a to 13d of the cutter 5, are the same as those of the first embodiment.
Numeral 4 is a telescopic gripper, all of which project radially from the shaft 2 in the horizontal direction and extend and contract with the cylinder 7.

The pushing mechanism of the cutting blade of the cutter 5 may be advanced and retracted by the screw jack 24 without using hydraulic pressure.

[0036]

As described above, the pipe cutting apparatus according to the present invention can stably and reliably cut the cutting blade of the pipe inside the pipe when cutting the pipe from the inside with a rotating cutter without using a firearm. And can be cut at any position.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of a pipe cutting device of the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a view taken in the direction of arrows BB in FIG. 1;

FIG. 4 is a view taken along line CC of FIG. 1;

FIG. 5 is a view taken along line DD in FIG. 1;

FIG. 6 is an explanatory view of a cutting blade.

FIG. 7 is an explanatory view showing a case of a parting-type cutting tool of a cutting blade.

FIG. 8 is an explanatory diagram showing a case of a serious cutting tool of a cutting blade.

FIG. 9 is a vertical sectional side view showing another embodiment of the pipe cutting device of the present invention.

FIG. 10 is a cross-sectional plan view showing another embodiment of the pipe cutting device of the present invention.

FIG. 11 is a perspective view of a rotary driving power unit of a cutter showing another embodiment of the pipe cutting device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pipe to be cut 2 ... Shaft 3, 4 ... Gripper 3a, 4a ... Telescopic gripper 3b, 4b ... Fixed gripper 5 ... Cutter 6 ... Piping 7 ... Cylinder 7a ... Piston rod 8 ... Pressing plate 9 ... Mounting flange 10 ... Bearing 11 ... Rotating body 12 ... Cylinder 12a ... Piston rod 13a ~ 13d ... Cutting blade 14 ... Electric motor 14a ... Rotating drive shaft 15 ... Mounting flange 16 ... Pinion gear 17 ... Inner gear 18 ... Swivel 19 ... Drive wheel 20 ... Positioning support bracket 20a ... Center hole 21 ... Jack 21a ... Piston rod 21b ... Cylinder holder 22 ... Claw 22a ... Claw holder 23 ... Ratchet gear 24 ... Screw jack

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[Procedure amendment]

[Submission date] July 23, 1999 (1999.7.2)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Pipe cutting device

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium diameter pipe cutting apparatus capable of cutting a steel pipe or the like as an underground pipe from the inside.

[0002]

2. Description of the Related Art Various apparatuses have been proposed and applied for cutting metal pipes such as steel pipes and copper pipes and synthetic resin pipes such as vinyl chloride pipes. Of these, when cutting from the outside of the pipe, cutting with a rotating cutting blade or cutting with a firearm such as a burner is also possible, but is there any obstacles such as pipes in the water or soil? Alternatively, in situations where it is difficult to use firearms, it is desirable to cut the tube from the inside.

[0003] Japanese Patent Application Laid-Open No. 60-71110 discloses an apparatus in which a drive shaft of a cutting blade is inserted into a pipe and the cutting blade is rotated by rotation of the drive shaft. It can be found in the official gazettes.

[0004]

As described above, in order to cut the pipe from the inside, in the case where the rotary drive shaft is inserted into the pipe to the cutting position, the power transmission mechanism becomes complicated, and a stable cutting posture is maintained. Therefore, even if a reaction force roller moving on the inner circumference of the pipe is provided, the instability cannot be eliminated. Moreover,
Even if the cutting blade is a disk-shaped rotary cutter, it is more difficult to make a cut by contacting the rotary cutter with the inner wall of the pipe in a pressed state as the rotary drive shaft becomes longer.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the disadvantages of the prior art, and to stably and reliably insert the cutting blade of the cutter into the inner circumference of the pipe when cutting the pipe from the inside with a rotating cutter without using a firearm. An object of the present invention is to provide a tube cutting device which can cut at an arbitrary position in contact with the tube.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention firstly provides a gripper for pressing and fixing an end of a shaft inserted into a pipe to be cut to an inner peripheral surface of the pipe to be cut. As a combination of a telescopic gripper with a cylinder and a fixed gripper, three are protruded radially at 120 ° intervals, one of which is a telescopic gripper provided with a pressing plate at the tip of the cylinder, and the other two are It is a fixed gripper provided with a block-shaped pressing plate at the tip of a non-extended plate or bar, and the three grippers projecting radially protrude vertically (left and right) at intervals. At the position between the upper and lower (left and right) stage grippers, a plurality of cutters are driven radially around the shaft and the cutting blades of which are advanced or retracted by a cylinder or a jack. A cutting blade having a different inclination and a cutting blade performing chamfering, and a rotary drive power unit of the cutter is also provided at the shaft end. Second, the rotary drive power unit is an electric or hydraulic motor. Providing a cutter with an inner gear meshing with the gear provided on the third gear;
In addition, the rotary drive power unit is a telescopic sliding body such as a jack,
The gist of the present invention is to connect the cutter to a cutter via a ratchet mechanism which rotates by the expansion and contraction of the telescopic slide.

According to the first aspect of the present invention, the shaft is a non-rotating member for positioning the cutter at a cutting position, and is inserted into the pipe to be cut. Is fixed to the inner peripheral surface of the pipe to be cut by a gripper projecting vertically (left and right) at intervals.
Then, the cutter between the grippers smoothly and reliably advances the cutting blade by the cylinder or the jack, rotates while abutting on the inner periphery of the pipe to be cut, and cuts from the inner peripheral surface side of the pipe to be cut. Since the upper and lower sides (front and rear) of the cutter are fixed by the gripper, the cutter can be rotated in a stable state.

Further, since there is a fixed gripper as the gripper, hydraulic or pneumatic control is simplified as compared with a case where all the grippers are telescopic grippers. In addition, the cutting blade gradually extrudes as the cutter rotates, but the left cutting is performed with one of the cutting blades with different inclinations,
The right cutting is performed with the other cutting blade, and the cutting is performed efficiently so that the inclination is different from each other so that the front back surface does not receive much cutting resistance, and the chamfering cutting blade performs the chamfering.

According to the second aspect of the present invention, the rotary drive power section is an electric or hydraulic motor, which can continuously rotate, and the gear provided in the electric motor and the inner gear mesh with the reduction gear. And the rotation of the electric or hydraulic motor can be transmitted to the cutter as rotation with a large torque.

According to the third aspect of the present invention, the rotary drive power unit is a telescopic sliding member such as a jack, which can be moved by hydraulic pressure, and a ratchet mechanism including a cutter instead of a large-scale hydraulic motor. It can be rotated with a large torque in the direction.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional side view showing one embodiment of the pipe cutting apparatus of the present invention, FIG. 2 is a view taken along line AA of FIG. 1, FIG. 3 is a view taken along line BB of FIG. FIG. 5 is a view taken along the line DD in FIG. 5, and FIG.
It is a pipe to be cut such as a fume pipe or a synthetic resin pipe.

The pipe to be cut is, for example, a horizontally laid propulsion pipe buried in the ground by a propulsion method so as to connect a manhole as a pipeline, and the protective concrete is destroyed at a manhole remodeling work site. The remaining portion of the pipeline and the removal portion are cut off from the inside so that the remaining portion is not affected.

Further, a steel pipe sheet pile or the like may be a pipe to be cut, and in this case, it is a vertical pipe in the soil or underwater.

The pipe cutting device of the present invention presses and fixes the end of the non-rotating shaft 2 which is a member for positioning by inserting into the pipe 1 to be cut to the inner peripheral surface of the pipe 1 to be cut. It is provided with grippers 3 and 4 and a cutter 5 driven to rotate about the shaft 2.

Although the shaft 2 is not shown, the shaft 2 is connected to each other by a screw joint or the like to obtain a required length.
The piping 6 such as hydraulic or air and the wiring piping such as electricity can be formed in the pipe wall or can be built in the hollow interior.

The grippers 3 and 4 are provided at an interval above and below (right and left) with respect to the shaft 2, and as shown in FIGS. Protrusions were provided radially in the horizontal direction at appropriate intervals (in the example shown, three at 120 ° intervals).

The grippers 3 and 4 are telescopic grippers 3a and 4a provided with a block-shaped pressing plate 8 at the tip of a piston rod 7a of a hydraulic (or air) cylinder 7.
And two fixed grippers 3b and 4b provided with a similar pressing plate 8 at the tip of a non-extended plate or bar.

The cutter 5 includes the upper and lower grippers 3,
As shown in FIG. 4, a hydraulic (or air) cylinder 12 is provided between a rotary body (rotary block) 11 rotatably provided on a shaft 2 via a bearing 10.
The hydraulic cylinder 12 is used as a holder, and a plurality of cutting blades 13a to 13d are attached to the tip of a piston rod 12a of the hydraulic cylinder 12 at appropriate intervals (four at 90 ° intervals in the illustrated example). Was attached by insertion.

A swivel is formed in the pipe 6 between the rotating body 11 and the shaft 2, and the four hydraulic cylinders 12 communicate with a hydraulic circuit equal to the shaft 2 side. When lubricating, the four piston rods 12a are pushed out at the same time, and the cutting blades 13a
単 13d is a single-acting cylinder that comes out.

As shown in FIG. 6, the four cutting blades 13a to 13d have a left cutting blade 13a and a right cutting blade 13a.
b, divided into cutting edges 13c and 13d for chamfering. FIG. 7 shows the case of a parting-type cutting tool of the cutting blades 13a and 13b, and FIG.
The shape in the case of 13c, 13d serious bite is shown.

The four cutting blades 13a to 13d are arranged such that the left cutting blade 13a and the right cutting blade 13b are arranged in a straight line, and the chamfering cutting blades 13c and 13d are arranged in a straight line. The cutting blades 13a and 13b are arranged so as to be linearly aligned with each other. Further, the positions of the cutting blades 13a to 13d are slightly shifted so as not to be on the extension line from the center of the shaft 2 including the center of the hydraulic cylinder 12, so that the tip angle of the hydraulic cylinder 12 or the tip angle of the piston rod 12a is cut. A situation in which the cutting blades 13a to 13d do not reach the inner peripheral surface of the target pipe 1 is prevented from occurring.

The mounting flange 9 of the lower gripper 4 is provided with a mounting flange 15 for providing an electric motor 14 or a hydraulic motor (not shown) also as a rotation driving power unit of the cutter 5. Rotary drive shaft 14a
Is engaged with an inner gear 17 fixed to the rotary body (rotary block) 11. The combination of the pinion gear 16 and the inner gear 17 constitutes a speed reducer. In this embodiment, the electric motor
Two 14 are installed, and these are connected to one inner gear 17.

The inner gear 17 is screwed to a drive wheel 19 rotatably provided on the shaft 2 with the bearing 10 interposed therebetween. The drive wheel 19 is screwed to the rotating body 11.

Next, the use and operation will be described.
Is determined, and the grippers 3 and 4 are inserted into the tube 1 to be cut in a contracted state. At the cutting position, the telescopic grippers 3a and 4a of the grippers 3 and 4 are extended by the cylinder 7, and are fixed to the fixed grippers 3b and 4b. Gripper 3 while taking reaction force
All the pressing plates 8 are pressed and fixed to the inner peripheral surface of the pipe 1 to be cut.

When the shaft 2 is inserted, a lid-like positioning support fitting 20 is wrapped around the end of the pipe 1 to be cut, and the shaft 2 is passed through the central hole 20a of the positioning support fitting 20. Then, the shaft 2 is cut into the pipe 1 to be cut.
At the center position of.

When the cylinder 12 of the cutter 5 is extended in this state, the cutting blades 13a to 13d come out all at once and join the inner peripheral surface of the pipe 1 to be cut.

When the electric motor 14 is energized, the electric power is transmitted from the pinion gear 16 to the inner gear 17, the drive wheel 19 rotates, the cutter 5 also rotates, and the cutting blades 13a to 13a.
At 13d, the pipe 1 to be cut is cut. The cutting blade 13
a to 13d are gradually pushed out when the cutter 5 rotates, but the left cutting is performed by the cutting blade 13a and the right cutting is performed by the cutting blade 13b. Cutting is performed efficiently so as not to receive much cutting resistance, and chamfering is performed with the cutting blades 13c and 13d.

When the cutters 5 do not move due to the cutting blades 13a to 13d being caught, the cylinder 12 can be rotated again by retracting the cutting blades 13a to 13d.

After the pipe 1 to be cut is cut, the cutting blades 13a to 13d of the cutter 5 are retracted, and if the telescopic grippers 3a and 4a of the grippers 3 and 4 are retracted, locking with the pipe 1 to be cut is performed. Is released, the shaft 2 can be pulled out.

FIGS. 9 to 11 show a second embodiment of the present invention, in which the rotary drive power unit of the cutter 5 is a jack 21 as a telescopic sliding body, and this jack 21 fixes a piston rod 21a. A claw 22 is provided outside the cylinder holder 21b via a claw holder 22a.

The two jacks 21 are arranged at intervals.
In the meantime, a ratchet gear 23 was provided, the pawl 22 was engaged with the ratchet gear 23, and the ratchet gear 23 was connected to the cutter 5.

In this way, the jack 21 is connected to the cutter 5 via the ratchet mechanism.
When the cylinder 21 is extended, the cylinder holder 21b is pushed out, the pawl 22 rotates the ratchet gear 23, and the cutter 5 is driven to rotate.

When the jack 21 is contracted, the pawl 22 is disengaged from the teeth of the ratchet gear 23 and returns to its original position, and the cutter 5 is rotated only in one direction by repeating the expansion and contraction of the jack 21.

The other mechanisms, such as fixing with a gripper and the protrusion of the cutting blades 13a to 13d of the cutter 5, are the same as those in the first embodiment. Also, cutter 5
The pushing mechanism of the cutting blade may use the screw jack 24 to advance and retreat without using hydraulic pressure.

[0035]

As described above, the pipe cutting apparatus according to the present invention can stably and reliably cut the cutting blade of the pipe inside the pipe when cutting the pipe from the inside with a rotating cutter without using a firearm. And can be cut at any position.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of a pipe cutting device of the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a view taken in the direction of arrows BB in FIG. 1;

FIG. 4 is a view taken along line CC of FIG. 1;

FIG. 5 is a view taken along line DD in FIG. 1;

FIG. 6 is an explanatory view of a cutting blade.

FIG. 7 is an explanatory view showing a case of a parting-type cutting tool of a cutting blade.

FIG. 8 is an explanatory diagram showing a case of a serious cutting tool of a cutting blade.

FIG. 9 is a vertical sectional side view showing another embodiment of the pipe cutting device of the present invention.

FIG. 10 is a cross-sectional plan view showing another embodiment of the pipe cutting device of the present invention.

FIG. 11 is a perspective view of a rotary driving power unit of a cutter showing another embodiment of the pipe cutting device of the present invention.

[Description of Signs] 1 ... Pipe to be cut 2 ... Shaft 3, 4 ... Gripper 3a, 4a ... Telescopic gripper 3b, 4b ... Fixed gripper 5 ... Cutter 6 ... Piping 7 ... Cylinder 7a ... Piston rod 8 ... Press plate 9 ... Mounting Flange 10 ... Bearing 11 ... Rotating body 12 ... Cylinder 12a ... Piston rod 13a ~ 13d ... Cutting blade 14 ... Electric motor 14a ... Rotary drive shaft 15 ... Mounting flange 16 ... Pinion gear 17 ... Inner gear 18 ... Swivel 19 ... Drive wheel 20 ... Positioning support bracket 20a ... Center hole 21 ... Jack 21a ... Piston rod 21b ... Cylinder holder 22 ... Claw 22a ... Claw holder 23 ... Ratchet gear 24 ... Screw jack

Claims (4)

[Claims] 1. A plurality of grippers for pressing and fixing to an inner peripheral surface of a pipe to be cut are protruded at an end of a shaft inserted into the pipe to be cut radially and at intervals vertically and horizontally. At the position between the upper and lower (left and right) grippers,
A pipe cutting device, wherein a plurality of cutters, which are driven to rotate around a shaft and whose cutting blades advance and retreat by a cylinder or a jack, are radially provided, and a rotation driving power unit of the cutter is also provided at an end of the shaft. . 2. The tube cutting device according to claim 1, wherein the rotary drive power unit is an electric or hydraulic motor, and an inner gear meshing with a gear provided on the motor is connected to a rotating body provided with a cutter. 3. The pipe cutting device according to claim 1, wherein the gripper combines a telescopic gripper with a cylinder and a fixed gripper. 4. The tube cutting device according to claim 1, wherein the rotary drive power unit is a telescopic slide such as a jack, and is connected to the cutter via a ratchet mechanism that rotates by the expansion and contraction of the telescopic slide.