JP2000127086A - Pipe cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve exactness and safety of a cutting work by providing an operating part whose end is located in the vicinity of an installation surface of a pipe mounting base and which interlocks with rotation of a holder on either of the holder or the rotary shaft and rotating the holder by a stepping operation of the operating part. SOLUTION: When a worker pushes down an operating lever 12 till the operating level 12 is abutted on a wear plate (pipe clamp) 5b of a base frame 5 of a rotation amount adjusting tool 13, a rotary shaft 9 rotates, and a cutting blade 10a of a disc grinder 10 and a chamfering blade 10b rise by pushing down amount. In the pushing down operation of the operating lever 12, the operating lever 12 is projected to the vicinity of an installation surface of a pipe mounting base 2 so that the worker may foot-stepping a tip of the operating level 12, taking exactness and safety of a cutting work into consideration. Therefore, the worker can cut a pipe P mounted on a supporting roller 7, surely pressing and rotating the pipe P by using both of his hands.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe cutter for cutting or chamfering pipes such as a void pipe and a rigid vinyl chloride pipe.

[0002]

2. Description of the Related Art At a construction site, various pipes having different materials, structures, and sizes, such as spiral ducts, hard vinyl chloride pipes, and void pipes for formwork, are piped according to applications.
It is extremely rare to use so-called fixed-length pipes as they are, so when performing plumbing work, they can be cut at the site and adjusted to an appropriate length, or chamfered at the end of the pipe. Often used before. As a pipe cutter that performs such cutting work as cutting and chamfering of pipes,
In addition to the ease of transportation that can be carried to the site, it is also required to have a function that can perform cutting operations such as cutting and chamfering with high precision and easily.

The present applicant has proposed a novel pipe cutter satisfying such performance in Japanese Patent Application No. 10-32677. This pipe cutter, as shown in FIG.
A pipe is placed on a pair of support rollers arranged in parallel, and the pipe is cut by operating a cutting tool while rotating the pipe using the rotation of the support roller.

[0004]

By the way, in a pipe cutter adopting an apparatus structure in which a pipe is rotated by a support roller, an operator rotates the pipe while holding the pipe with a left hand and simultaneously holds a cutting tool with a right hand. It is necessary to perform different operations with different hands, but if you hold and rotate the pipe with only your left hand, you may suddenly move the pipe in its axial direction. And it is not always sufficient in terms of accuracy and safety of the cutting operation. This is especially true when the dominant hand of the worker is the right hand.

The present invention has been made against such a background of the prior art, and an object of the present invention is to make it possible for an operator to use both hands to securely press and rotate a pipe placed on a support roller, and to rotate the pipe. It is an object of the present invention to provide a pipe cutter which is capable of cutting a workpiece and further improves the accuracy and safety of the cutting operation.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a pipe mounting table having at least one pair of support rollers for mounting pipes arranged in parallel, and a cutting tool having a cutting blade at a tip end. A holder having a rotating shaft rotatably supported on the pipe mounting table at a base end side of the center of gravity of the stored cutting tool in the longitudinal direction with respect to the longitudinal direction of the stored cutting tool. With regard to the pipe cutter which is designed to bring the cutting blade of the cutting tool into contact with the pipe, the end is located near the installation surface of the pipe mounting table on either the holder or its rotation axis, and the rotation of the holder is performed. An interlocking operation unit is provided, and the holder can be rotated by stepping on the operation unit.

In this pipe cutter, a rotating shaft of a holder for detachably storing the cutting tool is rotatably supported on the pipe mounting base at a base end side of a position of a center of gravity in a longitudinal direction of the cutting tool. When the cutting operation is not performed, the cutting blade is located at a position separated from the pipe. Then, when performing the cutting operation, since the end of the operation unit that is interlocked with the rotation of the holder is located near the installation surface of the pipe mounting table, the operator steps on the end of the operation unit. By rotating the holder, the cutting blade can be brought into contact with the pipe.
Therefore, the worker can rotate the pipe placed on the support roller while holding the pipe with both hands, so that the accuracy and safety of the cutting operation can be further improved.

[0008]

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

FIG. 1 is a plan view of a pipe cutter 1 according to the present embodiment. The pipe cutter 1 is roughly provided with a pipe mounting base 2, a cutting tool holder 3, and a side box 4. Both are screwed to a rectangular frame-shaped base frame 5.

The pipe mounting table 2 is provided with a pair of side frames 6 and a support roller 7. At the upper end of each side frame 6, as shown in FIG. Support recesses 6a, 6b, 6c, 6d, 6e
Are formed. The support roller 7 has three rollers 7b mounted on a roller shaft 7a.
Stop both sides of b with fixtures so that they do not move left and right,
The pipe to be mounted can be provided with uniform support in its longitudinal direction. As for the size of the roller 7b, the outer diameter is 75 mm and the inner diameter is 20 mm. Reference numerals 8a and 8b denote reinforcing cylinders fixed to the side frames. A rod-shaped measure 8c that can expand and contract in the X direction like a fishing rod can be stored inside the reinforcing cylinder 8a.
This measure 8c has a reference position “0” at a portion located on the extension of the cutting blade of the cutting tool just mounted on the holder 3.
Is stamped, and the length of the pipe to be cut can be measured by graduations cut at predetermined intervals in the extending direction from there.

FIG. 2 is a front view of each side frame 6 of FIG. Reference numeral 6f denotes a mounting hole for the reinforcing cylinder, and 6g denotes a support hole serving as a "support portion" of the rotating shaft 9 connected to the holder 3 of the cutting tool. Also, five pairs of support recesses 6a to
6e is formed at the upper end of the side frame 6 so that the arrangement state is substantially V-shaped. Support recesses 6a to 6e
The angle formed by each of the substantially V-shaped lines formed by the array with the horizontal line is approximately 3
It is 4 degrees. The positions where the support recesses 6a to 6e are formed are shown as design values in FIG. 2, and the unit is millimeter. When the support recesses 6a to 6e are formed in this manner, the lower ends of the pipes having different diameters placed on the support roller 7 are positioned at different specific positions according to the respective pipes (see FIGS. 5 to 9). The center axis of the support roller 7 can be positioned.

The holder 3 is formed in a cylindrical shape, and a disk grinder 10 as a cutting tool is detachable. When the holder 3 is stored, a fixing screw 3c is inserted into a screw hole formed in the holder 3 so that the tip side of the disk grinder 10 can be inserted. Screw it into the screw hole in and fix it. 3 shown in FIGS. 1 and 3
a and 3b are cutting blades 10a of the disc grinder 10;
And an adjusting screw for finely adjusting the position of the chamfering blade 10b. By tightening these screws, the base end side of the disc grinder 10 is held, and the base end position of the disc grinder 10 can be finely adjusted in the left-right direction. I have. The method of this fine adjustment is, for example, the cutting blade 10a and the chamfer blade 10
When b contacts the central axis of the pipe placed on the support roller 7 from an oblique direction, the balance between the tightening amount of the right adjusting screw 3a and the tightening amount of the left adjusting screw 3b is changed. Correcting the inclination of the longitudinal axis of the disc grinder 10 with respect to the pipe,
The cutting blade 10a and the chamfering blade 10b are brought into straight contact with the pipe from an orthogonal direction.

An indicator 11 attached to the side plate of the holder 3 functions as an indicator for indicating the position of the cutting blade 10a hidden under the pipe during the cutting operation (see FIG. 4), and when the cutting operation is not performed. It functions as a safety device for regulating the rotation of the holder 3 (see FIG. 3). That is, when the cutting operation is not performed, the indicator 11 is moved to the base frame 5 as shown in FIGS.
And the tip thereof is located close to the base frame 5, so that even if the holder 3 is rotated in this state, the indicator 11 becomes a stick bar, and the cutting blade 10a The chamfer blade 10b does not rise and is not exposed to the outside. Then, when the indicator 11 is rotated to above the pipe during the cutting operation, it can be seen that the cutting blade 10a hidden below the pipe is located on the straight line indicated by the indicator 11.
At this time, since the indicator 11 is in pressure contact with the holder 3 under the bias of the coil spring 11a, the indicator 11 can be kept stationary at any rotational position.

The rotating shaft 9 attached to the holder 3 is shown in FIG.
As shown by, they are supported by supporting holes 6 g (see FIG. 2) of each side frame 6 so as to be parallel to the supporting roller 7. As described above, the holder 3 is connected to the rotation shaft 9 that is bridged over the side frames 6, and the support holes 6 g of the rotation shaft 9 and the support recesses 6 a to 6 e of the support roller 7 are symmetric with respect to each side frame 6. Because it is formed in the position,
The support roller 7 and the rotating shaft 9 that are stretched over each side frame 6 are always parallel. Therefore, the sizes and positions of the screw holes formed through the lower end flange 6h of each side frame 6 and the base frame 5 are different from the design values in units of zero commas for the left and right side frames 6 due to tolerances and dimensional errors. Even in a case where the side frames 6 are fixed to the base frame 5 in a state where they are not slightly parallel to each other, the rotation shaft 9 and the support roller 7 position the support holes 6g and the support recesses 6a to 6e in symmetric positions. Are always parallel to each other, so that the orthogonality of the cutting blade 10a and the chamfering blade 10b with respect to the central axis of the pipe is also ensured.

Reference numeral 12 denotes an operation lever of the holder 3 fixed to the rotation shaft 9, and as shown in FIG. When the operating lever 12 is pushed down until it comes into contact with 5b, the rotating shaft 9 is rotated and the cutting blade 10a and the chamfering blade 1 of the disc grinder 10 are moved by the same amount as the pushing down.
0b rises. When the operation lever 12 is pressed down, the operation lever 12 is projected to the vicinity of the installation surface of the pipe mounting base 2 so that the operator can step on the tip of the operation lever 12 in consideration of the accuracy and safety of the cutting operation. . Therefore, the operator can cut the pipe P while rotating the pipe P placed on the support roller 7 while securely pressing the pipe P with both hands. Also,
Two fastening screws 12 for fixing the operation lever 12 to the rotation shaft
a (see FIG. 4), the operating lever 12 can be removed from the installation surface.
Of the operating lever 12 in the longitudinal direction of the rotating shaft 9 can be adjusted.

Reference numeral 13 attached to the operation lever 12 is a turning amount adjusting tool for adjusting the turning amount of the holder 3, that is, the cutting depth of the cutting blade 10a into the pipe P. As shown in FIG. 4, the rotation amount adjuster 13 includes a knob 13 b in which a screw portion 13 a is screwed into a through hole of the operation lever 12, and a rotation of the screw portion 13 b with respect to the through hole of the operation lever 12. The lock nut 13c keeps the amount of protrusion of the screw portion 13b from the lock nut 13c constant. Here, holder 3
The method of adjusting the amount of rotation of the operating lever 12 will be described. If it is desired to reduce the amount of rotation after loosening the lock nut 13c, turn the knob 13a clockwise to turn the operating lever 12
If it is desired to increase the amount of protrusion of the screw portion 13b protruding from the lower end of the control lever 12 and increase the amount of rotation, the knob 13a is rotated counterclockwise to reduce the amount of protrusion of the screw portion 13b protruding from the lower end of the operation lever 12. Then, the lock nut 13c is tightened again to fix the knob 13a so as not to rotate. At this time, the threaded portion 13b and the through hole of the operation lever 12 screwed to the threaded portion 13b are finely threaded, so that the cutting edge 10a and the chamfering edge of the disc grinder 10 can be freely adjusted in a unit of zero comma several millimeters. The height of the upper end position of 10b can be adjusted.

The side box 4 attached to the right side of the holder 3 is box-shaped, and has an upper lid 4a and a right side plate 4b openably and closably attached. FIG. 1 shows a state in which the upper lid 4a and the side plate 4b are opened. The side box 4 is large enough to substantially cover the side surface of the holder 3, so that even if the pipe cutter 1 is dropped or hit, an impact is directly applied to the right side frame 6 and the holder 3. Therefore, the support roller 7 and the rotating shaft 9 are kept parallel. Also, in consideration of safety, the side box 4 accommodates the cutting blade 10a and the chamfer blade 10b of the disc grinder 10 in a state where the holder 3 is not rotated, that is, when the pipe is not cut, without being exposed to the outside. Has become.

When the holder 3 is rotated, that is, when the pipe is cut, the cutting blade 10 is attached to the upper lid 4a of the side box 4.
An opening 4c is formed so that the uppermost portion of the portion a is exposed to the outside from a slightly lower portion. Therefore, even during the cutting operation, the entire cutting blade 10a is not exposed to the outside, so that the safety can be further secured. Further, at the time of cutting the pipe, the facet can be introduced into the side box 4 through the opening 4c, so that the facet is not scattered around. 4d projecting in a cylindrical shape in front of the side box 4 is a discharge port of a cut piece, and a suction port of a vacuum cleaner (not shown) is attached to the discharge port 4d so that the cut piece stored in the side box 4 can be discharged. I have. The ventilation holes 4e formed through the upper lid 4a are for generating an airflow to the discharge port 4d in the side box 3 when suctioning the cutting pieces by the vacuum cleaner, thereby enhancing the suction effect of the cutting pieces. The side plate 4b can be opened and closed from the lowermost end of the side surface of the side box 4, so that cut pieces collected by a broom or a vacuum cleaner can be taken out.

Next, a description will be given of a chamfering operation performed on the ends of pipes having different diameters by the pipe cutter 1 having the above-described apparatus configuration.

The JIS standard specifies two types of rigid vinyl chloride pipes, VP and VU. Here, as an example, a nominal diameter of 100, which is widely used for drain pipes, is used.
The case where the ends of the VP tubes 150, 200, 250, and 300 are chamfered will be described. Of the support recesses 6a to 6e of the side frame 6 designed as shown in FIG.
a is used for supporting a VP tube having a nominal diameter of 100. Similarly, the support recess 6b has a nominal diameter of 150, the support recess 6c has a nominal diameter of 200, the support recess 6d has a nominal diameter of 250, and the support recess 6 has a nominal diameter of 250.
e is used for supporting a VP tube having a nominal diameter of 300, respectively. The state in which these VP tubes are mounted on the respective support recesses 6a to 6e via the support rollers 7 is schematically shown in FIGS. As shown in FIGS. 5 to 9, when five types of VP tubes P1 to P5 having a nominal diameter of 100 to 300 are placed on the support roller 7 at the respective support recesses 6 a to 6 e, the larger the nominal diameter becomes, , Each VP tube P
1 to P5 are positioned at specific positions where the lower end positions are gradually lowered. The positions of the cutting blade 10a and the chamfering blade 10b are at the same height in each figure.

In the case of chamfering the end of the VP pipe P1 having a nominal diameter of 100, first, as shown in FIG. After being placed, the chamfering blade 10 as shown in FIG.
c is 1/100 of the thickness d1 of the VP pipe P1 having a nominal diameter of 100.
In order to cut about three times, the turning amount adjuster 13
Is changed, and the upper end position of the chamfering blade 10c when the holder 3 is rotated to the maximum is adjusted. Then, the end of the VP pipe P1 is chamfered by rotating the chamfering blade 10c.

Next, when chamfering the end of the VP pipe P2 having a nominal diameter of 150, as described above,
As shown in FIG. 6A, the support roller 7 is moved to the support recess 6 without touching the rotation amount adjuster 13 already adjusted for the pipe P1.
b, and a VP pipe P2 with a nominal diameter of 150 is placed,
As shown in FIG. 6B, when the holder 3 is rotated to the maximum, the upper end position of the chamfer blade 10c is positioned at a height position at which the VP pipe P2 can be cut by approximately 1/3 of the thickness d2. ing.

Similarly, the VP pipes P3 to P5 having the nominal diameters 200, 250, and 300 are similarly kept in contact with the rotation amount adjuster 13 which has been adjusted for the VP pipe P1 having the nominal diameter of 100. To the supporting recess 6
c, 6d, and 6e, and mounted (FIG. 7A)
9 (a)), the upper end position of the chamfering blade 10c when the holder 3 is rotated to the maximum can cut the wall thicknesses d3, d4 and d5 of the VP tubes P3, P4 and P5 by approximately 1/3. The position is determined.

When the support recesses 6a to 6e are formed as shown in FIG. 2, any one of the support recesses 6a to 6e is formed.
When the cutting depth of the chamfering blade 10b is adjusted to １ ／ of the wall thickness of any one of the VP tubes, the other supporting recess 6a
The lower end position of the other VP tube placed on the support roller 7 through 6e is positioned at a "specific position" where the thickness is cut by approximately 1/3 by the chamfering blade 10b. I have. Therefore, once the upper end position of the chamfering blade 10b is adjusted for a VP tube of a certain size, it is not necessary to adjust the upper end position of the chamfering blade 10b again for a VP tube of another size.
The chamfering operation of cutting the thickness of each of the VP pipes 0, 200, 250, and 300 by 1/3 can be performed. When adjusting the upper end position of the chamfering blade 10b for the first time, the screw 13
Since the threaded connection between a and the through hole of the operation lever 12 is performed by a fine screw, the vertical movement of the operation lever 12, that is, the vertical movement of the chamfer blade 10b can be adjusted with high accuracy in units of a few millimeters of a comma.

For VU pipes having a nominal diameter of 75 and 125, which are widely used for water supply pipes, the support rollers 7 are attached to the support recesses 6a and 6b in FIG.
Since the lower end position of each VU tube is not positioned at the above-mentioned “specific position”, a supporting recess is formed in accordance with each VU tube so that the lower end position of each VU tube is positioned at the above “specific position”. In this case, an auxiliary plate which is detachable from the side frame 6 is used.

The pipe to be cut is a pipe cutter 1
If the object is too long to support, a pipe mounting table (not shown) having the same device structure as that of the pipe mounting table section 2 is installed beside the pipe cutter 1. Then, it is necessary to make the pipe cutter 1 parallel to the pipe mounting table. In this case, the pipe cutter 1 and the pipe mounting table are laid with iron pipes frequently used on site, and the pipes attached to the base frame 5 respectively. The iron pipe bridged by the clamp 5c is held. In this way, even if the pipe is long, appropriate support can be provided, and the rotation thereof is facilitated, which is convenient.

In the above embodiment, the support recesses 6a to 6e of the side frame 6 are formed with dimensions as shown in FIG. 2, but the present invention is not limited to this, and each substantially V-shaped line forms a horizontal line. The angle and the position at which each support recess is formed, the chamfering depth of one of the support recesses with respect to the pipe is adjusted to 1/3 of the wall thickness, and the other support recesses are used for other pipes. It is also possible to change such that the lower end positions of all the pipes are positioned at "specified positions" where the thickness can be substantially chamfered. Also,
The number of the support recesses is arbitrary.

In the above embodiment, the operation lever 12
Although the example in which only one rotation amount adjustment tool 13 fixed to the above is provided is shown, for example, two rotation amount adjustment tools 13 may be provided for each adjustment of the VP tube and the VU tube. Further, in the above-described embodiment, an example in which the operation lever 12 is fixed to the rotation shaft 9 is shown. However, the operation lever 12 may be attached to the holder 3 of the disc grinder 10, for example.

Further, in the above embodiment, the side frame 6
Only the portions where the supporting recesses 6a to 6e are formed may be replaceably attachable / detachable.

[0030]

According to the present invention, the pipe is cut by moving the cutting blade up and down by stepping on the foot while the operator securely presses and rotates the pipe placed on the support roller using both hands. Therefore, the accuracy and safety of the cutting operation can be further improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a pipe cutter according to an embodiment of the present invention.

FIG. 2 is a front view of the side frame of FIG. 1;

FIG. 3 is a rear view of the holder of FIG. 1 and a disc grinder stored in the holder.

FIG. 4 is a schematic view showing a state where cutting blades (cutting blades and chamfering blades) of a disc grinder come into contact with a pipe by rotation of a holder of FIG. 1;

FIG. 5 is a diagram schematically showing a positional relationship between a VP pipe having a nominal diameter of 100 and placed on a support roller provided in a support recessed portion 6a and a chamfering blade during a chamfering operation.

FIG. 6 is a diagram schematically showing a positional relationship between a VP tube having a nominal diameter of 150 mounted on a support roller in a support concave portion 6b and a chamfering blade during a chamfering operation.

FIG. 7 is a diagram schematically showing a positional relationship between a VP pipe having a nominal diameter of 200 and a chamfering blade placed on a support roller provided in a support recessed portion 6c during a chamfering operation.

FIG. 8 is a diagram schematically showing a positional relationship between a VP tube having a nominal diameter of 250 and a chamfering blade placed on a support roller provided in a support recess 6d during a chamfering operation.

FIG. 9 is a diagram schematically showing a positional relationship between a VP pipe having a nominal diameter of 300 and a chamfering blade, which are placed on a support roller provided in a support concave portion 6e during a chamfering operation.

FIG. 10 is a view showing a conventional example of a pipe cutter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe cutter 2 Pipe mounting base part 3 Holder 3a Disk grinder fixing screw 4 Side box 4a Top lid 4b Side plate 4c Opening 4d Discharge port 4e Vent 4f Engaging part 4g Engagement receiving part 5 Base frame 5a Fixing screw 5b Backing plate 5c Pipe clamp 6 Side frame 6a to 6e Support recess (support portion of support roller) 6f Mounting hole 6g Support hole (support portion of rotation shaft) 6h Lower end flange 7 Support roller 7a Roller shaft 7b Roller 7c Roller fixing tool 8a, 8b Reinforcement cylinder 8c Measure 9 Rotating axis 10 Disc grinder (cutting tool) 10a Cutting blade 10b Chamfering blade 11 Indicator 11a Coil spring 12 Operating lever (operating part) 12a Fastening screw 13 Rotation amount adjusting tool 13a Knob 13b Screw 13c Locker Door

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[Procedure amendment]

[Submission date] October 30, 1998 (1998.10.
30)

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Claims (1)

[Claims] 1. A pipe mounting table having at least one pair of support rollers for pipe mounting arranged in parallel, and a cutting tool having a cutting blade on a tip end side are detachably housed,
A holder having a rotation axis rotatably supported on the pipe mounting table at a base end side of the center of gravity of the stored cutting tool in the longitudinal direction with respect to the center of gravity. The pipe cutter is adapted to be brought into contact with the pipe, and has an operating part having an end located near the installation surface of the pipe mounting table and being interlocked with the rotation of the holder, on one of the holder and the rotating shaft thereof. A pipe cutter characterized in that the holder can be rotated by a stepping operation of an operation unit.