JPH07136830A - Cutting device - Google Patents

Abstract

PURPOSE:To provide a cutting device which can cut a pipe from the inside in the radial direction of the thin pipe. CONSTITUTION:A basic board body 36 of a cutting device is arranged inside an inner pipe 1 to be cut. The first arm 18 is turned by the turning driving force of a driving motor 14 fixed on the basic board body 36. One end part 20a of the second arm 20 is supported in a turnable manner at the other end part 18a of the first arm 18 through a shaft 44, and a supporting roller 22 which is installed in a turnable manner at the other end part of the second arm 20 makes contact with the inner wall of the inner pipe 1. A cutter 24 which is installed in the vicinity of the other end part of the second arm 20 cuts the inner pipe 1 from the diameter inside. At this time, the turning radius which is represented by the distance from a rotary shaft 42 to the cutter 24 can be varied by varying the angle formed by the first arm 18 and the second arm 20.

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 cutting a thin cylindrical tube.

[0002]

2. Description of the Related Art Conventionally, as a device for cutting a tubular pipe, a blade of a cutting device is pressed from the outside of the pipe and the pipe is cut by traversing in the radial direction of the pipe. For example, cutting is performed by a cutter along the circumferential direction of the pipe, and the pipe is cut so as to go around the circumferential direction once. There is also a method in which a thin tube is rotated and a cutter is cut from the outside of the rotating tube.

[0003]

However, according to the conventional cutting device, when the thin pipe to be cut is covered with a rigid outer pipe, the cutting device is provided outside the pipe. There is no extra space to install. For this reason, when cutting such a pipe, the pipe is cut in advance outside to make it into a pipe having a predetermined size and then buried in a narrow space or underground.

However, in a narrow space or underground, if the pipe can be cut from the inner wall side of the pipe, the pipe installation work or the cutting work can be easily performed. Further, when a thin, large-diameter tube is cut while pressing it with a cutter from the outside, the tube is distorted and the deformation becomes large, which makes cutting difficult. The present invention has been made from such a viewpoint, and an object thereof is to provide a cutting device capable of cutting a thin-walled pipe from the inside in the radial direction.

It is another object of the present invention to provide a cutting device which can be cut with the same device even if the diameter of a thin pipe to be cut is changed.

[0006]

DISCLOSURE OF THE INVENTION The present invention is for solving the above-mentioned problems, and includes a base that can be installed inside a tubular body to be cut, a drive source fixed to the base, and A first arm whose one end is fixed to a rotary drive shaft of a drive source;
A second arm whose one end is rotatably supported by the other end of the first arm, and a tubular body which is rotatably supported by the other end of the second arm and is cut. Is attached near the other end of the second arm and the guide means abutting the inner wall of the second arm, and the distance from the center of the rotary drive shaft is farther than the distance to the guide means, and the cutting is performed. And a cutting means for cutting the tubular body.

The cutting device of the present invention has the above-mentioned structure.
An arrangement is provided which comprises arm angle changing means capable of changing an angle formed by the first arm and the second arm so that a distance from a center of the rotary drive shaft to the cutting means is variable. adopt.

[0008]

According to the construction of the cutting device of the present invention, the cutting device main body is installed inside the pipe, the first arm is swiveled around the rotary drive shaft, and the diameter in the rotational direction from the rotary drive shaft to the cutting device is set. By bending the arm at the indirect part of the first arm and the second arm so that the tube can be changed, the tube is cut around by turning around the tube in the circumferential direction.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, the cutting device is installed on the inner diameter side of the tube to be cut. That is, as shown in FIG. 2, the cutting device is inserted in the direction of arrow 100 into the inner pipe 1 inserted into the thick outer pipe 2.

Specific examples of the cutting device are shown in FIGS.
Shown in. In FIG. 2, a thin inner tube 1 to be cut is inserted inside a thick cylindrical outer tube 2. Outer tube 2
The gap between the inner tube 1 and the inner tube 1 is very small. Then, the cutting device 10 is installed inside the outer tube 2. The cutting device 10 includes a base 12, a hydraulic motor 14 as a drive source, and a power transmission device 1.
6, first arm 18, second arm 20, support roller 2
2, a cutter 24, a hydraulic cylinder 26 as a turning radius varying means, and a pressure sensor 28.

The base 12 is provided with supports 32 and 34 for fixing it to the outer tube 2, and a base body 36 is installed by these supports 32 and 34. The base 12 supports the cutter and a first arm 18 and a second arm 20 described later. Further, the inner pipe 1 is fixed by the guide 55 fixed to the base 12.
The end of is supported. That is, a circular arc-shaped portion of a part of the outer peripheral portion of the inner pipe 1 is supported by the guide 55, the inner pipe 1 is held by the guide 55, and the inner pipe 1 is held at a position immediately left in FIG. Is cut by the blade portion 48.

The hydraulic motor 14 is fixed to a base main body 36, a gear 38 fixed to a drive shaft of the hydraulic motor 14 meshes with a gear 40, and the other end side of a rotary shaft 42 fixing the gear 40. The first arm 18 is fixed to the. The rotation force of the hydraulic motor 14 is transmitted to the first arm 18 via the gear 38, the gear 40, and the rotation shaft 42.

One end 18a of the first arm 18 on the rotation center side is fixed to the other end 42a of the rotary shaft 42. One end of a shaft 44 is rotatably supported by the other end portion 18a on the radially outer side of the first arm 18, and the other end of the shaft 44 is rotatably supported by the second arm 2
An end 20a of the rotation center side of 0 is attached. The second arm 20 is supported rotatably about a shaft 44, and a support roller 22 is rotatably provided on the other end side.

The support roller 22 is in contact with the inner wall of the inner tube 1 to be cut and rotatably supported on the other end side of the second arm 20, and has a role of positioning the cutting position of the cutter 24 described later. . That is, the support roller 22 is the inner tube 1
Guide the inner wall of the cutter in the circumferential direction, and use this guide to cut the cutter 2.
The rotation center position of No. 4 is determined, and it has a role of smoothly cutting.

The cutter 24 comprises a drive motor 46 and a blade portion 48 rotated by the drive motor 46.
The drive motor 46 is fixedly attached to the other end side of the second arm 20. The rotation shaft 4 of this drive motor 46
A blade portion 48 having a disk-shaped blade is fixed to 6a. As shown in FIG. 4, the hydraulic device 26 as the turning radius varying means includes a hydraulic cylinder 50 and a rod 52 that expands and contracts in the axial direction of the hydraulic cylinder according to the pressure of the hydraulic chamber in the hydraulic cylinder. One end 52a of the rod 52 is rotatably attached to the end of the second arm 20 near the outside in the radial direction. The rod 52 is extendable / contractible in the directions of arrows B and C shown in FIG. 4, and the position of the rod 52 is
It becomes variable according to the hydraulic chamber in the hydraulic cylinder 50 by the command of the hydraulic control means 56 shown in FIG.

The hydraulic control means 56 inputs the signal of the pressure sensor 28 for detecting the pressure of the hydraulic line 57 communicating with the hydraulic cylinder 50, and, for example, the hydraulic signal becomes a constant value according to the signal. First, hydraulic oil is supplied to the hydraulic chamber so that the hydraulic chamber of the hydraulic cylinder 50 is kept constant.
As a result, the rod 52 determines the expansion / contraction position so that the contact force of the support roller 22 provided at the tip of the second arm 20 against the inner tube 1 is constant. Therefore, the first arm 18 and the second arm 2 are moved in the direction of arrow D about the rotation shaft 42.
When 2 swivels, the radius-of-rotation changing means 26 can be rotated along the circumferential direction of the inner pipe 1 by expanding and contracting the rod 52.

When the turning radius varying means 26 turns about the rotating shaft 42 in the direction of arrow D, the blade 48 is rotated by the drive motor 46. As a result, even if the rotary shaft 42, which is the center of rotation of the cutting device, is not located at the center of the inner tube 1, the inner radius of the inner tube 1 is changed by the rotation radius varying means 26 making one rotation in the circumferential direction.
Can be cut. Next, the operation of the cutting device 10 will be described.

First, the cutting device 10 is inserted into the outer tube 2 in the direction of arrow 100 shown in FIG. At this time, as shown in FIG. 1, the rotary shaft 42 of the cutting device 10 is moved to the center O of the inner pipe 1.
It is assumed that it is installed at a lower position that is eccentric by a distance δ. This is to make it possible to cut the pipe to be cut regardless of the eccentric position of the cutting device 10 set to the rotation axis. At this time, the outer peripheral circular arc surface of the inner tube 1 is supported by the guide 55.

Next, the hydraulic motor 46 is rotationally driven to rotate the blade portion 48. Then, as shown in FIG. 1, the angle α formed by the first arm 18 and the second arm 20 is increased to, for example, α
_The support roller 22 is brought into contact with the inner wall of the position tube _{1 at} an angle of 1. At this time, the blade portion 48 starts cutting the inner pipe 1.
Then, the first arm 18 is rotated about the rotation axis 42 in the counterclockwise direction as shown in FIG. At the same time, the hydraulic signal from the pressure sensor 28 adjusts the length of the rod 52 by the hydraulic control means 56 so that the pressure value in the hydraulic chamber becomes constant. Thus, the inner pipe 1 makes one round around by the rotation of the blade portion 48, and the inner pipe 1 is cut while the radius of rotation around the rotation axis 42 formed by the first arm 18 and the second arm 20 is variable. After the cutting is completed, the rotation of the rotary shaft 42 is stopped, the second arm 20 is folded, and the rotation of the blade portion 48 is stopped. This completes the cutting.

In this embodiment, the folding angle of the first arm 18 and the second arm 20 is controlled based on the signal of the pressure sensor 28, but the turning radius of the cutter 24 is controlled by other sensors and control means. It may be variably controlled. Further, in this embodiment, since the outer peripheral circular arc surface in the vicinity of the end portion of the inner pipe 1 is supported by the guide 55, the inner pipe is pressed and cut by the hub 48 of the cutter 24 while maintaining the shape of the inner pipe. It can be cut without distortion.

[0021]

As described above, according to the cutting apparatus of the present invention, there is an effect that the cutting apparatus is installed inside the pipe and the cutting can be performed from the inner diameter side of the pipe. Therefore, if there is no extra space outside the pipe, installing this device inside the pipe enables cutting from inside the pipe,
This has the effect of improving the operability.

Further, according to the cutting device of the present invention, even if the diameter of the thin pipe to be cut is changed, the first arm and the second arm
There is an effect that they can be cut by the same device by an indirect bending action that serves as a connecting portion of the arm.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view according to the first embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a portion III in FIG.

FIG. 4 is a schematic diagram showing a radius-of-rotation changing means according to a first embodiment of the present invention.

[Explanation of symbols]

 1 Inner Pipe 10 Cutting Device 12 Base 14 Hydraulic Motor (Drive Source) 16 Power Transmission Device 18 First Arm 20 Second Arm 22 Support Roller 24 Cutter 26 Rotation Radius Variable Means 28 Pressure Sensor 46 Motor (Cutter) 48 Blade Part ( Cutter) 50 Hydraulic cylinder (turning radius changing means) 52 Rod (turning radius changing means) 55 Guide 56 Hydraulic control means

Claims (2)

[Claims] 1. A base that can be installed inside a tubular body to be cut, a drive source that is fixed to this base, and one end that is fixed to a rotary drive shaft of this drive source.
An arm, a second arm whose one end is rotatably supported by the other end of the first arm, and a rotatably supported one end of the second arm by the other end. And a guide means that abuts the inner wall of the tubular body, and is attached near the other end of the second arm, and the distance from the center of the rotary drive shaft is farther than the distance to the guide means. A cutting device, comprising: a cutting means for cutting a tubular body to be cut. 2. An arm angle changing means capable of changing an angle formed by the first arm and the second arm so that a distance from a center of the rotary drive shaft to the cutting means is variable. The cutting device according to claim 1, which is characterized in that.