JPH068034A - Pipe cutting tool - Google Patents

Abstract

PURPOSE:To provide a pipe cutting tool capable of sectionally cutting a pipe easily with extremely small force while being compact, portable, low-priced and easily usable in a narrow place. CONSTITUTION:A recessed part 3 allowing a pipe 2 to be inserted rotatably without looseness from an inlet-outlet 1 is formed at base material 4, and a cutting tool 5 for biting and sectionally cutting the pipe 2 inserted into the recessed part 3 is fitted to the base material 4 in such a way as to protrude into the recessed part 3. The tool tip 6 of the cutting tool 5 is gradually tapered, and the cutting tool 5 is fitted into a position out of the width direction centerline Y-Y of the recessed part 3. The cutting edge 7 of the cutting tool 5 is fitted in such a way as to face the back wall 8 of the recessed part, and the tool tip 6 of the cutting tool 5 is fitted into such a position as to collide with the pipe 2 before the pipe 2 collides with the back wall 8. The protruding length of the cutting tool 5 is set into such length as to be able to pierce only the wall of the pipe 2 inserted into the recessed part 3, and the peripheral wall surface 9 of the recessed part 3 is protrusively provided with guide rails 11 to be fitted into the hollows of the corrugated pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugated flexible conduit tube having an electric wire, a cable or the like drawn therein, and a pipe cutting tool capable of easily cutting a pipe or the like into which it is not drawn.

[0002]

2. Description of the Related Art When wiring electric wires, cables, etc. on a floor or wall of a building made of reinforced concrete, conventionally, a corrugated flexible conduit is embedded in the concrete to be the floor or wall, and after the concrete is solidified, Wires and cables are drawn and passed through the corrugated flexible conduit.

In recent years, the construction industry has been required to shorten the construction period, but the delay in construction due to lack of manpower has become serious. In order to solve this even a little, it is considered that electric wires and cables are previously drawn into the corrugated flexible conduit tube at the factory and then laid. In order to realize this, it is necessary to cut out the corrugated flexible conduit to expose the ends of the wires or cables by the length required for wiring. In this case, there is a need for a pipe cutting tool that can easily cut only a corrugated flexible electric wire tube in a narrow place without cutting or damaging the internal electric wires or cables.

As a pipe cutting tool which is considered to be usable for such an application, there is one shown in FIG. This is a semi-ring shaped pipe gripping part 30, 31 with a handle part 3.
The pipe gripper 3 is a cutting tool that opens and closes by 2, 33.
A blade 34 is provided on the inside of 0, 31 in a protruding manner.

[0005]

However, in this pipe cutting tool, the gripping parts 32 and 33 must be constantly tightened and turned so that the pipe gripping parts 30 and 31 do not open, and the cutting operation is easy. There was a problem not.
In addition, this pipe cutting tool also has a problem that a large force is required when the cutting tool 34 is cut into the pipe.

It is an object of the present invention to provide an inexpensive pipe cutting tool that can easily cut various pipes such as a corrugated flexible conduit tube and a pipe not corrugated with a light force.

[0007]

The pipe cutting tool according to claim 1 of the present invention, as shown in FIG.
The base material 4 is formed with a recessed portion 3 which can be inserted rotatably and rotatably, and the base material 4 is formed so that a blade 5 that cuts into the pipe 2 inserted into the recessed portion 3 and cuts the pipe 2 protrudes into the recessed portion 3. A pipe cutting tool attached to
The blade 5 is provided with the following conditions.

[0008] The cutting edge 6 of the cutting tool 5 is gradually tapered as shown in FIG. ． As shown in FIGS. 5 and 6, the blade 5 is attached so that the blade tip 6 is located at a position deviated from the widthwise center line Y-Y of the recess 3. ． The cutting blade 7 of the blade 5 faces the central portion O side of the back wall 8 of the recess 3 as shown in FIG. ． As shown in FIGS. 4 and 9, the blade edge 6 of the blade 5 is a recess 3
The pipe 2 to be inserted therein should be arranged at a position where it hits the pipe 2 before hitting the inner wall 8 of the recess 3.

According to the second aspect of the present invention, as shown in FIG. 10, the width of the recess 3 can be changed.

A pipe cutting tool according to a third aspect of the present invention is a guide rail 11 which is fitted into the peripheral wall surface 9 of the recess 3 shown in FIG. 1 and into the valley 10 of the pipe 2 which is corrugated as shown in FIG.
Is projected.

[0011]

The pipe cutting tool according to claim 1 of the present invention is shown in FIG.
As shown in FIG. 9, when the pipe 2 is inserted into the recess 3 of the base material 4, as shown in FIG. 9, the pipe 2 abuts on the cutting edge 6 of the cutting tool 5 and a rotational moment about the cutting edge 6 is generated.
This rotational moment acts on the pipe 2 in the direction of the arrow M in FIG. 9 (direction of the cutting blade 7 of the cutting tool 5), so that the pipe 2 rotates in the direction of the arrow M relative to the pipe cutting tool and moves in the concave portion 3. Fits in the back. At this time, FIG. 4 (a) (b) (c)
The cutting edge 6 of the blade 5 bites into the pipe 2 in the order shown in.

After the pipe 2 is housed in the recess 3 and the substrate 4 is turned in the direction in which the blade 5 is directed to the central portion O of the back wall 8 (direction of arrow A in FIGS. 2 and 3), the blade 5 is cut. The pipe 2 is torn by the cutting blade 7 of. At this time, since the pipe 2 is constrained by the back wall 8 and the side wall in the direction in which the blade 5 faces,
The pipe 2 does not come out from the innermost part of the recess 3. In this way, when the blade 5 makes one rotation, the pipe 2 is sliced.

In the pipe cutting tool according to the second aspect of the present invention, since the width of the concave portion 3 can be changed, the pipe 2 of various sizes can be sliced by one pipe cutting tool.

With the pipe cutting tool according to the third aspect of the present invention, the pipe 2 can be sliced in the same manner as in the above case. Furthermore, in this pipe cutting tool, in the case where the pipe 2 is a corrugated flexible conduit in which electric wires, cables, etc. C are drawn as shown in FIG. 7, a corrugated flexible conduit is used as shown in FIG. Valley 1
Since the guide rail 11 is fitted in the position 0, when the base material 4 is rotated once in this state, the base material 4 is guided by the valleys 10 without being shaken and guided correctly in the circumferential direction of the pipe 2.

[0015]

[Embodiment 1] A pipe cutting tool of the present invention will be described in detail with reference to the embodiment of FIG. In the pipe cutting tool shown in this figure, a concave portion 3 is formed in a base material 4, a guide rail 11 and a holding protrusion 13 are formed on a peripheral wall surface 9 of the concave portion 3, and a single blade 5 is formed on the base material 4. It is attached so as to project into the recess 3.

The base material 4 is made of plastic, wood, metal or the like. The base material 4 of FIG. 1 is horizontally long, and the handle 21 is formed on the right side portion thereof, and the concave portion 3 is formed on the left side portion thereof.
It is designed so that a large turning force can be obtained.

The recess 3 in FIG. 1 is formed in a substantially U-shape, and its width is set to a size approximately the same as the diameter of the pipe so that the pipe fits snugly, so that the pipe can be rotated without loosening. It can be inserted. The concave portion 3 in FIG. 1 is formed obliquely on the base material 4 so that the inlet / outlet 1 opens to the outer peripheral surface 23.

The guide rail 11 is fitted in two adjacent valleys (ring-shaped grooves) of the corrugated flexible conduit (pipe 2) shown in FIG. 7 as shown in FIG. , Two thin plates on the peripheral wall surface 9 of the recess 3 and two adjacent valleys 10
Are provided in parallel according to the interval (wave pitch). In the case of FIG. 1, this guide rail 11 is formed on the peripheral wall 9
Although it is formed intermittently at a location, it may be formed continuously over the entire peripheral wall surface 9. Further, when used for cutting a pipe that is not corrugated, the guide rail 11 is not always necessary.

The holding protrusion 13 (FIG. 1) is the pipe 2
The base material 4 is rotated along the outer circumference of
It is provided as a precaution in order to reliably prevent the pipe cutting tool of the present invention from falling out of the pipe 2 when it is positioned below the pipe (in a state of being hung on the pipe 2). The holding protrusion 13 of FIG. 1 is connected to the guide rail 11 on the right side of the peripheral wall surface 9 and protrudes further into the recess 3 than the guide rail 11. As a result, the outer periphery of the pipe 2 can be held and held from below.

The blade 5 has a base portion 24 as shown in FIG.
In the state in which is embedded in the base material 4, only the tip portion of the cutting blade 7 is projected into the recess 3. Conditions such as the structure and the mounting position of the blade 5 are as follows.

[0021]. As shown in FIG. 1, the blade tip 6 of the blade 5 is tapered so that it can easily bite into the pipe 2. ． As shown in FIG. 1, the blade 5 is attached so that its blade edge 6 is located at a position deviated from the widthwise center line YY of the recess 3. In the case of FIG. 1, the center line YY of the recess 3 in the width direction.
It is mounted on the left side and near the back wall 8. ． The cutting blade 7 of the blade 5 is directed toward the central portion O of the back wall 8 of the recess 3 as shown in FIG. As a result, when the pipe 2 is inserted into the recess 3 of the base material 4, the cutting blade 7 of the blade 5 bites into the pipe 2 as shown in FIG. Further, the pipe 2 does not come out of the recess 3 when the base material 4 is rotated in a predetermined direction. ． A pipe 2 into which a blade tip 6 of a blade 5 is inserted into a recess 3
Is arranged at a position where it hits the pipe 2 before hitting the inner wall 8 of the recess 3. When the cutting edge 6 of the cutting tool 5 is positioned in this way, as shown in FIG. 9, the pipe 2 abuts on the cutting edge 6 while the pipe 2 is being inserted into the recess 3 and the pipe 2
A rotational moment in the direction of arrow M is applied to. ． The protruding length of the blade 5 is such that the blade 5 can penetrate the meat of the pipe 2 and the blade 5 that has bitten into the ridges 12 between the valleys 10 penetrates the ridges 12 as shown in FIG. It is designed so that it does not project inward from the bottom of the. As a result, when the electric wire or cable C is drawn into the pipe 2 as shown in FIG. 7, only the pipe 2 is cut without damaging the electric wire or cable C or cutting them. can do.

Next, an example of use in the case of cutting a corrugated flexible conduit by the pipe cutting tool of this embodiment will be described. First, the base material 4 is pressed against the pipe 2 (the pipe 2 is relatively inserted into the recess 3). At this time, as shown in FIG. 8, each of the two guide rails 11 is fitted into each of the two adjacent valleys 10 of the corrugated flexible conduit (pipe 2) to form the corrugated flexible conduit. While being guided by the guide rails 11, the guide rails 11 are inserted into the recesses 3 without being displaced.

When the inserted pipe 2 hits the blade edge 6 of the blade 5, the blade edge 6 is used as a fulcrum and the arrow M in FIG.
A rotational moment is generated in the direction. This rotation moment M
Is expressed by the following equation. {M = F ・ a = f ・ (L + a) / a ・ a = f (L +
a)} This rotation moment causes the pipe 2 to be inserted until it abuts on the inner wall 8 of the recess 3 while rotating in the direction of arrow M in FIG. 9 (direction of the cutting blade 7 of the blade 5). Then, the pipe 2 is gradually pushed down by the cutting blade 7 of the blade 5 as shown in FIGS. 4 (a) (b) (c). That is, the blade edge 6 of the blade 5 bites into the pipe 2. At this time, even if the pipe 2 is pushed in without being rotated, the pipe 2 hits the back of the cutting edge 6 and receives a large resistance, so that the pipe 2 cannot be pushed in without being rotated.

As described above, after the cutting edge 6 bites into the pipe 2 and the pipe 2 hits the inner wall 8 of the recess 3, the blade 5
When the substrate 4 is rotated in the direction toward the central portion O (the direction of arrow A in FIGS. 2 and 3), the pipe 2 is continuously torn by the cutting blade 7 of the blade 5. At this time, since the pipe 2 is constrained by the back wall 8 and the side wall in the direction in which the blade 5 faces, the recess 3
The pipe 2 never comes out of the. When the blade 5 makes one revolution, the widthwise center of the peak 12 (FIG. 8) between the adjacent valleys 10 of the pipe 2 is sliced by the blade 5. That is, in the pipe cutting tool of this example, the blade 5 is on the left side of the center line YY of the recess 3 as shown in FIG.
And it is pressed against the right side wall. Therefore, even if the base material 4 is not pressed against the corrugated conduit tube by hand from beginning to end, the corrugated conduit tube is torn only by rotating. Incidentally, the cutting force P (FIG. 3) of the pipe 2 by the blade 5 is P = f · L / a.
In the pipe cutting tool of this example, since there is only one blade 5, the resistance during cutting is small.

[0025]

[Embodiment 2] The pipe cutting tool shown in FIG. 5 uses a substantially rectangular base material 4, and locking protrusions 22 for hanging fingers during rotation are formed at the four corners thereof. The recess 3 is formed in a rectangular shape and straight in the width direction of the base material 4. The peripheral wall surface 9 of the recess 3 is formed flat. In this example, the blade 5 is provided on the left side of the central portion O of the back portion 8 of the recess 3.

Also in the pipe cutting tool of this embodiment, as in the case of the first embodiment, the pipe 2 inserted into the recess 3 hits the cutting edge 6 of the blade 5 before reaching the innermost part of the recess 3, so that the pipe 2 The rotary moment acts on the blade 2 and the blade 5 easily bites into the pipe 2.

Further, in the pipe cutting tool of this embodiment, the base material 4 is used.
Has a shape in which the locking protrusions 22 are provided so as to protrude from the four corners of the rectangle, so that it can be mounted on the pipe 2 and rotated even in a narrow space. Therefore, the pipe cutting tool of this embodiment is convenient for use in a narrow space.

[0028]

[Third Embodiment] In the pipe cutting tool shown in FIG. 5B, the blade 5 is attached to the right side of the central portion O of the inner portion 8 of the recess 3. For this reason, the cutting blade 7 of the blade 5 is formed on the left side. Also in the pipe cutting tool of this embodiment,
The same action and effect as those of

[0029]

Fourth Embodiment FIG. 6 shows another embodiment in which the position of the blade 5 is changed. The position of the blade 5 may be such that the blade 5 penetrates the meat of the pipe 2 inserted in the deepest portion of the recess 3 as shown in FIG.
Even if it is provided in the back of the recess 3 as shown in FIG.
It may be provided on the entrance / exit side of the recess 3 as shown in FIG.

[0030]

Fifth Embodiment In the pipe cutting tools of the first to fourth embodiments, the width of the recess 3 is fixed, but the width of the recess 3 may be variable. For example, as shown in FIG.
Is composed of a fixed base material 25 and a movable base material 26, and a movable base material 26 having a long hole 27 formed therein is slidably attached to the fixed base material 25. ,
The width of the concave portion 3 formed between the 29 may be adjustable. In this pipe cutting tool, the movable base material 26 is set at a desired position, and then the thumbscrew 30 is tightened to fix the movable base material 26 to the fixed base material 25.

In addition, in the pipe cutting tool shown in FIG. 10, the protruding amount of the blade 5 can be changed. In the conventional pipe cutting tool shown in FIG. 12, since the pipe must be gripped by the pipe gripping portions 30 and 31, only the pipe that fits the inner diameter of the gripping portions 30 and 31 can be cut. Since the pipe 2 can be cut if it is housed in the recessed portion 3, the width of the recessed portion 3 is made variable as in the pipe cutting tool shown in FIG. Can cut pipes 2 of any diameter up to large pipes 2. Further, in the pipe cutting tool shown in FIG. 10, since the protruding amount of the blade 5 is variable, pipes 2 having different wall thicknesses can be cut appropriately.

[0032]

COMPARATIVE EXAMPLE 1 FIG. 11 (a) shows a pipe cutting tool that cannot achieve the above-mentioned effects. In the pipe cutting tool of this comparative example, the cutting edge 6 of the cutting tool 5 is located in the inner part 8 and on the widthwise center line Y-Y of the recess 3. When the blade 5 is attached in this way, since the rotational moment does not act on the pipe 2 inserted into the recess 3, the blade tip 6 of the blade 5 does not bite into the pipe 2 unless the pipe 2 and the blade 5 are relatively strongly pressed. The mounting position is not suitable as the mounting position of the blade 5.

[0033]

Comparative Example 2 FIG. 11B shows a second example of a pipe cutting tool in which the blade 5 is not properly mounted. In this pipe cutting tool, the cutting blade 7 of the cutting tool 5 faces the side opposite to the central portion O of the inner portion 8 of the recess 3. In this pipe cutting tool, when the cutting tool is turned, the pipe 2 is pushed out from the recessed portion 3,
The cutting tool is lifted and the pipe 2 cannot be cut.

In the first embodiment described above, the case of cutting a corrugated flexible conduit tube has been described as an example, but the pipe cutting tool of the present invention can also cut an ordinary round pipe which is not corrugated. When cutting a round pipe, one with a guide rail 11 may be used, but as shown in FIG.
Those without 1 may be used. The pipe cutting tool of the present invention can cut not only plastic pipes but also rubber pipes and metal pipes such as thin-walled aluminum.

[0035]

The pipe cutting tool of the present invention has the following effects. Since a rotational moment acts on the inserted pipe 2, the blade 5 surely bites into the pipe 2 even if the pipe 2 is inserted with a slight force. ． Since the base material 4 can be downsized because it can bite into the pipe 2 with a slight force, it is convenient to carry and can be configured to be used even in a narrow place such as under a reinforcing bar. After the pipe 2 is housed in the recessed portion 3, the pipe 2 can be cut by simply turning the substrate 4, so that the cutting operation is easy. ． With the pipe cutting tool according to the second aspect, it is possible to cut pipes of various sizes with one piece. ． In the pipe cutting tool according to claim 3, the corrugated pipe 2
There is an advantage that the deviation of the cutting line at the time of cutting can be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a pipe cutting tool of the present invention.

FIG. 2 is a perspective view showing a state in which a corrugated flexible conduit is inserted into a recess of the pipe cutting tool of the present invention.

FIG. 3 is a front view of a state in which the pipe is vertically cut in the state of FIG.

4 (a), (b) and (c) are partial explanatory views of the cutting process of the blade of the pipe cutting tool of the present invention into the pipe.

5 (a) and 5 (b) are explanatory views of an example in which the tool cutting position of the pipe cutting tool of the present invention is different.

6 (a) and 6 (b) are explanatory views showing still another example of the blade mounting position of the pipe cutting tool of the present invention.

FIG. 7 is an explanatory diagram showing an example of a flexible electric wire tube with a wave containing an electric wire.

FIG. 8 is a vertical cross-sectional explanatory view of the upper half of a state where a flexible electric wire tube with electric waves containing electric wires is cut by the pipe cutting tool of the present invention.

FIG. 9 is an explanatory diagram of a rotation moment of the pipe cutting tool of the present invention.

FIG. 10 is an explanatory view of the pipe cutting tool of the present invention in which the width of the recess can be changed.

11 (a) and 11 (b) are front views showing different examples of the pipe cutting tool in which the installation state of the blade is poor.

FIG. 12 is a front view showing a conventional pipe cutting tool.

[Explanation of symbols]

 1 Entry / Exit 2 Pipe 3 Recess 4 Base Material 5 Blade 6 Cutting Edge 7 Cutting Edge 8 Back Wall O Central Part 9 Peripheral Wall 10 Valley 11 Guide Rail

Claims (3)

[Claims] 1. A base material 4 is formed with a recess 3 into which a pipe 2 can be inserted rotatably and rotatably from an inlet / outlet 1.
Is a pipe cutting tool that is attached to a base material 4 so as to protrude into the recess 3 by cutting into the pipe 2 inserted into the pipe 2 and cutting the pipe 2 in a circular manner. A pipe cutting tool characterized by being equipped with. ． The cutting edge 6 of the cutting tool 5 is gradually tapered. ． The blade 5 should be attached so that the blade tip 6 is located at a position deviated from the center line Y-Y of the recess 3 in the width direction. ． The cutting blade 7 of the blade 5 faces the central portion O side of the back wall 8 of the recess 3. ． A pipe 2 into which a cutting edge 6 of a blade 5 is inserted into a recess 3.
Is arranged at a position where it hits the pipe 2 before hitting the inner wall 8 of the recess 3. 2. The pipe cutting tool according to claim 1, wherein the width of the recess 3 is variable. 3. The pipe cutting tool according to claim 1, characterized in that a guide rail (11) fitted into a trough (10) of the corrugated pipe (2) is projectingly provided on a peripheral wall surface (9) of the recessed portion (3). Cutting tool.