JP3537036B2 - Pipe cutting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manual pipe cutting machine suitable for cutting steel pipes buried underground for protecting transmission lines.

[0002]

2. Description of the Related Art When a transmission line is buried underground, the transmission line is passed through a steel pipe (carbon steel pipe) for protecting the transmission line. Power line may need to be provided. In this case, the steel pipe covering the transmission line at the branch point is cut into two sections at
After removing the necessary length of steel pipe for branching, perform the branching work on the transmission line.

FIG. 8 shows a conventional example of a main part of a pipe cutting machine used for cutting a steel pipe. In this conventional pipe cutting machine, an annular frame (not shown) is attached to an outer peripheral surface of a steel pipe to be cut. It is supposed to. When the pressing handle (11) provided to protrude to the outside of the frame is rotated, the lever member (12) rotatably supported by the frame is pushed downward, and the disc-shaped cutting blade (13) is pressed against the steel pipe p. Will be done. In this pressed state, when the frame is rotated with respect to the steel pipe p,
The cutting blade (13) gradually cuts the outer peripheral surface of the steel pipe p to a predetermined depth. When this cutting operation is completed around the steel pipe p, the pressing blade (11) is operated to push the cutting blade (13) into the steel pipe p to a predetermined depth to perform the above-described cutting operation of the steel pipe p. By repeating such a series of operations a plurality of times, the steel pipe p can be cut into round sections.

[0004]

By the way, such a tube cutting machine has a simple structure and excellent portability, and achieves its intended purpose. The problem has been pointed out.

That is, depending on the space where transmission lines are buried, there are cases where a plurality of steel pipes are buried side by side at narrow intervals of, for example, about 60 mm due to space restrictions. When the steel pipes are arranged at such a narrow interval, the frame can be barely wrapped around the steel pipe p with the above-described pipe cutting machine,
When the frame is rotated with respect to the steel pipe p, the pressing handle (11) protruding to the outside of the frame comes into contact with an adjacent steel pipe, so that the steel pipe p cannot be completely sliced. There is.

The following problems have been pointed out with respect to the structure of the conventional pipe cutting machine. That is, FIG.
As shown in the figure, in this pipe cutting machine, the pressing handle (1
By tightening 1), the tightening force is transmitted as the pressing force of the cutting blade (13) against the steel pipe p. However, if the hardness of the sliding surface (11a) of the pressing handle (11) at which the tightening force is generated or the strength of the screw (11b) of the pressing handle (11) is insufficient, the tightening force generated by the pressing handle (11) is insufficient. Cannot be transmitted to the cutting blade (13) with the same strength, and the pressing force of the cutting blade (13) against the steel pipe p is weakened. In order to compensate for such deterioration of the transmission of the tightening force, it is sufficient to simply increase the torque applied to the pressing handle (11) .However, in a dug up ground where the working space is limited, the pressing handle (11) is manually operated. There is also a limit to the rotation as desired, and it is very difficult to generate enough torque to compensate for transmission degradation with human power.

The present invention has been made in the background of such a conventional pipe cutting machine, and an object of the present invention is to completely cut a pipe even if a plurality of pipes to be cut are arranged at narrow intervals. An object of the present invention is to provide a tube cutting machine having a simple device structure.

Another object of the present invention is to provide a tube cutting machine having an apparatus structure capable of applying a large pressing force to a cutting blade on a tube to be cut.

[0009]

To achieve the above object of the Invention The present invention comprises an outer circumferential adhesive capable annular frame tube to be cut, the pair of arms hinged attached to the annular frame A cutting mechanism that connects the opposing ends with a turnbuckle, provides a cutting blade between the hinge attachment point of each arm and the opposing end, and moves the cutting blade toward the center of the annular frame by tightening the turnbuckle. tube cutting machines odor comprising a part provided in the annular frame
And a recess formed over the entire circumference of the annular frame.
A stop groove is formed, and a chain of a chain wrench is formed in the lock groove.
And a pipe cutting machine characterized by accommodating a pipe.

According to this pipe cutting machine, since the cutting mechanism is provided in the annular frame and there is no device portion protruding outside the outer periphery of the annular frame, a plurality of pipes to be cut are arranged at narrow intervals. Even so, as long as the annular frame can be circumferentially attached to the tube, it is possible to cut the tube all around without the rotating annular frame hitting the adjacent tube.

Further, according to the cutting mechanism as described above,
When the turnbuckle is tightened, each arm rotates with the hinge attachment point as a fulcrum, and accordingly the cutting blade moves toward the center of the annular frame (toward the center of the steel pipe) and is pressed against the pipe to be cut. become. Therefore, the tightening force of the turnbuckle can be applied as a pressing force of the cutting blade to the pipe, so that a stronger pressing force can be applied to the cutting blade than in a conventional pipe cutting machine.

In order to perform the cutting operation after setting the above-described pipe cutting machine on the pipe to be cut, it is necessary to rotate the pipe cutting machine with respect to the pipe.
It is preferable that the locking groove for accommodating the chain of the chain wrench is formed in a concave shape over the outer periphery of the annular frame. According to this, even if the chain is wound around the locking groove formed concavely over the outer periphery of the annular frame, the chain is not housed inside the locking groove and does not protrude outside the annular frame. Therefore, even if a plurality of pipes to be cut are arranged at narrow intervals, the chain hooked on the annular frame does not hit the adjacent pipe and does not hinder cutting by the pipe cutting machine. Further, it is preferable to use a chain wrench to rotate the pipe cutting machine, because handling is easy and workability is improved.

Further, as the annular frame of the pipe cutting machine as described above, for example, only one opposing end of a half frame can be separated and the other opposing end cannot be separated from each other, such as handcuffs. Both opposing ends of the half frame may be configured to be separable from each other. Of course, the annular frame may have a configuration that can be divided into two or more, instead of being divided into half.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a steel pipe cutting machine (1) according to an embodiment.
FIG. 3 is a view showing a chain wrench (2) for rotating a cutting machine (1) around a steel pipe. This cutting machine (1) is a dedicated machine for cutting a steel pipe (carbon steel pipe) for protecting transmission lines.

As shown in FIG. 1, the cutting machine (1) has an annular frame (3) having a half structure, and each of the divided frames (3a) (3b).
Are opened and closed via a hinge connection part (3c). In order to close the divided frames (3a) and (3b) to form an entire ring, the divided frame (3d)
The pin members (3f) may be inserted into the pin holes with the connecting projections (3e) of (b) inserted so that the divided frames (3a) and (3b) do not separate from each other. The closed annular frame (3) has a slightly larger inner diameter than the outer diameter of the steel pipe to be cut, and the radial width of the annular frame (3) is slightly smaller than 60 mm. It is formed as follows.

As shown in FIG. 2, each of the divided frames (3a) and (3b) is provided with a cutting mechanism so as not to protrude outside the annular frame (3). That is, this cutting mechanism is an arm
(4), a disk-shaped cutting blade (5), and a hexagonal tension nut
A turnbuckle (6) in which a right screw bolt (6a) and a left screw bolt (6b) are screwed to each end of (6a).

FIG. 3 is an exploded perspective view of the cutting mechanism.
(4) is an arm hinged to the divided frames (3a) (3b) via a pin member (4a). The arm (4) has a disk-shaped cutting blade (5) on the pin member (4b). It is rotatably supported via. The other end of the arm (4) opposite the hinge attachment point (4c) (see FIG. 2) is connected to the right screw bolt (6a) or the left screw bolt (6b) constituting the turnbuckle (6) with a pin member (4d). Have been.

Next, a procedure for cutting a steel pipe using the cutting machine (1) having the above configuration will be described.

First, each divided frame (3a) (3b) shown in FIG.
Is opened, an annular frame (3) is wrapped around a steel pipe p to be cut, and then the two divided frames (3a) and (3b) are closed and connected by a pin member (3f) (see FIG. 2). ).

Next, an operation of pressing the cutting blade (5) against the steel pipe p is performed. This includes a spanner as shown in FIG.
The tension nut (6a) is rotated in the tightening direction using a suitable tool such as. Then, as shown in FIG. 5, the arm (4) receives the tension of the right-hand screw bolt (6b) or the left-hand screw bolt (6c), and turns around the hinge mounting point (4c) in the direction of the outer peripheral surface of the steel pipe p using the hinge mounting point (4c) as a pivot point. Move. Along with this, the cutting blade (5)
Moves in the direction of contact with the outer peripheral surface of the steel pipe p and comes into contact therewith. Further, when the tension nut (6a) is tightened, it comes into pressure contact with the steel pipe p so as to bite. Thus, turnbuckle
Since the tightening force of (6) can be transmitted to the cutting blade (5) without deterioration, a strong pressing force can be applied to the cutting blade (5). Further, since a strong pressing force can be applied to the cutting blade (5), the torque for rotating the tension nut (6a) can be relatively small, and the cutting blade (5) can be applied to the steel pipe p with relatively small force even by human power. You can bite it.

When the cutting blade (5) is brought into pressure contact with the steel pipe p in this manner, the chain wrench shown in FIG.
The chain (2a) of (2) is hooked on a locking groove (3g) formed in the annular frame (3) shown in FIG.

For this purpose, as shown in FIG. 6, first, the wrench body (2a) is placed on the upper part of the cutting machine (1). At this time, insert the thin bent part (2b) of the wrench body (2a)
Wrench body so that it goes into the locking groove (3g) of (3)
Place (2a). The bent part (2b) of the wrench body (2a)
Has a thickness slightly smaller than the width of the locking groove (3 g).

In this state, the other end of the chain (2c) having one end fixed to the upper side of the bent portion (2b) is turned from the lower side of the annular frame, and the insertion hole ( 2d).

The chain (2c) passed through the insertion hole (2d)
In order to provide the fixation, a stopper (7) as shown in FIG. 7 is used. This stopper (7) is provided with a pin (7a) that can be inserted into the gap of the chain (2c), and a spring (7) provided inside the housing (7b).
By (7c), the structure is always biased in the pop-out direction.

In order to fix the chain (2c) by using the stopper (7), the screw at the tip of the housing (7b) is attached to the wrench body.
After being screwed into the screw hole at the end of (2a) to be in the mounted state, the pin (7a) is pulled against the bias of the spring (7c). Then, the chain (2c) passed through the insertion hole (2d) of the wrench body (2a) is pulled until an appropriate tension is obtained, and the tension of the pin (7a) is released. Then the pin (7a)
Is inserted into the gap of the chain (2c), and the chain (2c) is fixed.

After the chain (2c) is fixed as described above, when the wrench body (2a) is pulled in the forward direction x as shown in FIG. 6, the cutting machine (1) is rotated with respect to the steel pipe p. be able to. At this time, the bent part (2b) of the wrench body (2a)
1 is knurled as shown in FIG. 1, while the bottom of the locking groove (3g) of the annular frame (3) is knurled in a lattice, so that the bent portion (2b) and the locking groove are formed. The contact resistance with the wrench (3g) is sufficiently large that the wrench body (2a) does not slip. In addition, the locking grooves (3g) cut in a knurled shape in a grid form can increase the contact resistance with the chain (2c), so even when rotating the cutting machine (1), the chain
(2c) does not slip in the locking groove (3g),
Cutting work can be performed stably.

When the cutting machine (1) is rotated around the steel pipe (p), the cutting blade (5) is no longer pressed against the steel pipe (p). Therefore, the tension nut (6a) is tightened again to cut the cutting blade (5).
, And then the cutting machine (1) is further rotated once. By repeating such a series of operations a plurality of times, the steel pipe p can be cut into a round section.

In the above embodiment, a steel pipe (carbon steel pipe) has been described as an example of an object to be cut. However, it is a matter of course that a hard PVC pipe, a void pipe or the like may be cut.

[0030]

According to the pipe cutting machine of the present invention, even if a plurality of pipes to be cut are arranged at narrow intervals, the adjacent pipes are not obstructed and the pipes are completely cut. be able to. Further, it is possible to apply a large pressing force to the pipe to be cut to the cutting blade.

[Brief description of the drawings]

FIG. 1 is a view showing a steel pipe cutting machine and a chain wrench according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a cutting mechanism provided inside the cutting machine shown in FIG. 1;

FIG. 3 is an exploded perspective view of the cutting mechanism shown in FIG. 2;

FIG. 4 is an explanatory view of a use state of the cutting machine of FIG. 1;

FIG. 5 is a view for explaining the pressing operation of the cutting blade shown in FIG. 2 against a steel pipe.

FIG. 6 is an explanatory view of a use state in which the cutting machine of FIG. 1 is combined with a chain wrench.

FIG. 7 is an enlarged cross-sectional view of a main part of a chain wrench tip portion showing a fixed state of the chain of FIG.

FIG. 8 is an explanatory view of a main part showing an example of a conventional pipe cutting machine.

[Explanation of symbols] (1) Cutting machine (pipe cutting machine) (2) Chain wrench (2a) Wrench body (2b) Bent part (2c) Chain (2d) Insertion hole (3) Ring frame (3a) Split frame (3b) Split frame (3c) Hinge connection (3d) Connecting recess (3e) Connecting projection (3f) Pin member (3g) Lock groove (4) Arm (4a) Pin member (4b) Pin member (4c) Hinge attachment point (4d) Pin member (5) Cutting blade (6) Turnbuckle (6a) Tension nut (6b) Right screw bolt (6c) Left screw bolt (7) Stopper (7a) Pin (7b) Housing (7c) Spring

Claims (1)

(57) All Claims comprising an outer to allow peripheral deposition annular frame tube to be cut, along with connecting the opposite ends of the pair of arms hinged attached to the annular frame turnbuckle, of each arm In a tube cutting machine provided with a cutting mechanism provided in the annular frame, a cutting blade is provided between the hinge attachment point and the opposite end, and the cutting blade is moved in the center direction of the annular frame by a tightening operation of the turnbuckle . Of the annular frame
A locking groove is formed on the outer circumference and is formed over the entire circumference.
Hold the chain of the chain wrench in the notch
Tube cutting machine, characterized in that the.