JP2010023117A - Circular pipe cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circular pipe cutting tool which is lightweight and inexpensive and capable of facilitating cutting of even a long stretching and small-bore circular pipe from the inside. <P>SOLUTION: The cutting tool includes a shaft support portion 2 for rotatably supporting a shaft 4 having a ratchet tooth-shaped thread; a grip 5 tightened on an end portion 4a of the shaft 4 projecting from a rear face 2b thereof; a slider 6 fitted onto the shaft support portion 2 so as to be capable of advancing and retreating; tension springs 7, 7 for forcing a slider 6 toward the forward shaft portion 2; a stopper 8 having a claw portion 8a engageable with the thread of the shaft 4 and rotatably mounted inside a square hole 6a in the slider 6; a cutter support portion 12 and a roller support portion 13 pivoted to the shaft support portion 2 and the slider 6 through link members 14a, 14b so as to be symmetric, sandwiching the shaft support portion 2 therebetween, positioned forward of the slider 6; and a cutter 3 and rollers 15, 15, each of which is supported by the cutter support portion 12 and the roller support portion 13. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circular tube cutting tool that cuts a circular tube used for piping equipment such as air conditioning and drainage from the inside, and in particular, it is easy to cut even if the diameter of the tube is small and long. The present invention relates to a tool for cutting a circular tube.

  It may be necessary to cut a part of a plastic or metal circular pipe used for piping equipment such as air conditioning or drainage after installation. Generally, in such a case, the circular tube is often cut from the outside by applying a cutting tool blade to the outer peripheral surface. With this method, it is necessary to secure a working space for operating the cutting tool, and conventionally, wasteful work such as partially disassembling or temporarily removing the installed equipment occurs. It was. Therefore, in order to solve such a problem, in recent years, a method of cutting a circular pipe from the inner peripheral surface side by installing it in the pipe so that it is not necessary to provide a work space around the pipe is attracting attention. . Research and development have been actively conducted on a cutting instrument that can cut a circular tube from the inside, and several inventions and devices have already been disclosed in this regard.

For example, Patent Document 1 discloses an invention relating to a “pipe cutting device” that cuts a circular pipe embedded in the ground from the inner peripheral side into a circular cut state.
The invention disclosed in Patent Document 1 includes a fixed portion fixed in the vicinity of the opening of the circular tube, and a shaft portion extending from the fixed portion to the inner front side of the circular tube in a state where the axis is matched with the axis of the circular tube. A cutter that cuts the circular tube, a cutter pressing portion that moves the cutter in the radial direction of the shaft portion while holding the position of the cutter in the axial direction of the shaft portion, and presses the inner surface of the circular tube, and a fixed portion And an actuator that transmits a rotational driving force to the shaft portion to rotate the cutter and the cutter press around the axis of the shaft portion.
In the “tube cutting device” having the above structure, the circular tube can be easily and appropriately cut from the inside. In addition, it is possible to improve maintainability and workability.

Patent Document 2 discloses an invention relating to a “steel pipe cutting device” capable of safely and quickly cutting steel pipes.
The invention disclosed in Patent Document 2 includes a hydraulically driven clamp member that presses the inner wall of a cylindrical steel pipe, and a hydraulically driven type that is provided at the front end of the main casing so as to protrude toward the inner wall. Hydraulic pressure having a cutting processing unit composed of a cutting blade and a hydraulically driven rotary casing that holds the hydraulically driven cutting blade, and pressure detection means for supplying hydraulic pressure to the cutting processing unit and monitoring the hydraulic pressure with respect to the driving unit of the cutting blade And a drive unit.
According to the “steel pipe cutting device” having the above-described structure, it is possible to accurately grasp the cutting state of the steel pipe at the cutting work location. Moreover, while being able to protect a cutting blade, workability | operativity and safety | security can be improved.

Further, Patent Document 3 discloses a device relating to an apparatus for cutting a thick circular small-diameter long circular pipe from the inside under the name “small-diameter pipe cutting apparatus”.
The device disclosed in Patent Document 3 is a cutting tool for cutting a tube, a cutter holder that rotatably holds the cutter, a slide block that slides through the cutter holder and an inclined portion, and a slide block that is coupled to the slide block. A hydraulic cylinder having a piston and a reaction force roller.
In the “small-diameter pipe cutting device” having the above structure, since each member constituting the cutting machine head portion is disposed in the axial direction of the circular pipe, the circular pipe is inserted even if it has a small diameter. Can do. Further, since the two blades are configured to operate in synchronization with the opposing directions by the hydraulic cylinder, the blades can be pressed against the tube wall with a strong force. In addition, when the blade bites into the inner wall of the thick tube, the blade can be forcibly retracted from the tube wall. Therefore, it is possible to prevent a failure of the cutting machine head part due to the biting of the cutter into the tube wall.
JP 2005-334993 A JP 2000-282466 A Utility Model Registration No. 2506501

  However, since the invention disclosed in Patent Document 1 as the above-described prior art includes an actuator, the structure becomes complicated and the apparatus becomes large. Therefore, it is difficult to apply to small diameter pipes.

  Moreover, since the invention disclosed in Patent Document 2 incorporates a hydraulic drive unit in the main body, it is difficult to reduce the size and weight. Therefore, there is a problem that it cannot be applied to a small diameter steel pipe and is difficult to handle because it is heavy.

  The device disclosed in Patent Document 3 has a problem that it is not easy to reduce the weight because it incorporates a hydraulic cylinder. Further, when a long pipe is cut, it is necessary to lengthen the hydraulic cylinder, which increases the weight and increases the manufacturing cost.

  The present invention has been made in response to such a conventional situation, and provides a circular tube cutting tool that is light and inexpensive and can be easily cut from the inside even if it is a long and small-diameter circular tube. For the purpose.

In order to achieve the above object, a circular tube cutting tool according to claim 1 is a shaft having a thread, a shaft support portion that rotatably supports the shaft, and a rear half portion of the shaft support portion. A slider that is inserted so as to be able to move forward and backward, a stopper formed with a claw that can engage with a screw thread, a grip that is installed at the end of the shaft that protrudes backward from the shaft support, and a shaft that is in front of the slider A cutting blade support portion and a roller support portion that are arranged symmetrically with respect to the support portion, a roller that is supported by the roller support portion in parallel with the rotation center of the shaft, and a shaft that is rotated by the cutting blade support portion. A cutting blade pivotally supported at the central portion parallel to the moving center, and a distal end portion pivoted at the front portion of the cutting blade support portion or roller support portion, and a base end portion pivoted at the shaft support portion A pair of first A link member, and a pair of second link members having a distal end portion pivotally provided at the rear portion of the cutting blade support portion or the roller support portion and a proximal end portion pivotally provided on the slider, and the stopper is provided on the screw thread. On the other hand, the claw portion is attached to the slider so as to be freely engageable.
In the circular tube cutting tool having such a structure, the distance between the cutting blade support portion and the roller support portion can be increased by rotating the grip with the claw portion of the stopper engaged with the thread of the shaft. By changing, the diameter of the circumscribed circle formed by the cutting edge and the roller is changed. In addition, when cutting the circular tube, the roller support portion presses a roller arranged symmetrically with the cutting blade across the rotation center of the shaft against the inner peripheral surface of the circular tube, so that the cutting blade against the inner peripheral surface is pressed. It has the effect | action of preventing the fall of the contact pressure.

According to a second aspect of the present invention, in the circular tube cutting tool according to the first aspect, the slider is urged along the rotation center of the shaft by an elastic member connecting the shaft support portion. It is characterized by.
In the circular tube cutting tool having such a structure, when the engagement between the claw portion of the stopper and the thread of the shaft is released, the slider urged by the elastic member moves forward or along the rotation center of the shaft. It has the effect of retreating.

A third aspect of the present invention is the circular tube cutting tool according to the first or second aspect, wherein the tool has a thread having the same diameter and the same pitch as the shaft, and the front end thereof is freely detachable from the rear end of the shaft. An auxiliary shaft connected to the auxiliary shaft, an auxiliary shaft support portion that rotatably supports the auxiliary shaft, and an auxiliary shaft support portion that is externally inserted so as to be able to advance and retract, and a slider and a grip are inserted in front of the auxiliary shaft support portion. An auxiliary slider provided with a hole, a through hole provided in communication with the insertion hole on the side surface of the auxiliary slider, an auxiliary claw portion engageable with a screw thread of the auxiliary shaft, and an auxiliary shaft screw An auxiliary stopper that can be attached to the auxiliary slider so that the auxiliary claw can be engaged with the mountain, and an auxiliary grip that is attached to the rear end of the auxiliary shaft that protrudes backward from the auxiliary shaft support. An auxiliary shaft connection means consisting of a flop, the slider is characterized in that it comprises a preventer omission is engaged with the through hole of the auxiliary slider.
In the circular tube cutting tool having such a structure, the auxiliary stopper functions in the same manner as the stopper, and the auxiliary grip functions in the same manner as the grip. Further, the auxiliary shaft has an action of rotating integrally with the shaft in a state where the auxiliary slider is mounted on the slider.

According to a fourth aspect of the present invention, in the circular tube cutting tool according to the third aspect, a pair of attachments that are detachably attached to the auxiliary slider at a predetermined interval from each other, and the pair of attachments A pair of guide roller support portions which are disposed symmetrically with the auxiliary slider in between, a guide roller which is supported in parallel with the rotation center of the auxiliary shaft by the guide roller support portion, and a tip portion Has an auxiliary slider guide means provided with four guide link members pivoted at one end of the guide roller support portion and pivoted at the base end portion of the fixture.
The circular tube cutting tool having such a structure has an effect that the rotation center of the shaft and the rotation center of the auxiliary shaft exactly coincide with the cylindrical axis of the circular tube by the auxiliary slider guide means.

According to a fifth aspect of the present invention, in the circular tube cutting tool according to any one of the first to third aspects, an insertion hole for holding the slider in a non-rotatable manner is formed at one end, and the other end is formed. The present invention is characterized by comprising a rotation assisting means comprising a slider holder provided with a handle mounting portion and a handle installed on the handle mounting portion.
The circular tube cutting tool having such a structure has an effect that the slider and the shaft support are simultaneously held by the slider holder.

  As described above, in the circular tube cutting tool according to claim 1 of the present invention, after the cutting blade is brought into contact with the inner peripheral surface of the circular tube, the slider is rotated together with the shaft support portion. The circular tube can be easily cut from the inside. Also, when cutting the circular pipe, if the contact pressure of the cutting edge against the inner peripheral surface is not appropriate, by rotating the grip, the mutual distance between the cutting edge support part and the roller support part is changed, It is possible to easily adjust the contact pressure. Thereby, the cutting state of a circular pipe is stabilized. Further, after the cutting of the circular tube is completed, the gripper is rotated in a predetermined direction with the claw portion of the stopper engaged with the screw thread of the shaft, so that the cutting blade and the roller are connected to the inner peripheral surface of the circular tube. It can be easily detached from. In addition, by operating the stopper to release the engagement between the claw portion and the thread of the shaft, the slider is moved backward relative to the shaft support portion, which is even shorter than the above method of rotating the grip. It is possible to separate the cutting blade and the roller from the inner peripheral surface with time.

  In the circular tube cutting tool according to claim 2 of the present invention, the cutting blade and the roller are inserted into the circular tube in a shorter time than when the shaft is rotated after the front portion is inserted into the circular tube. It can be brought into contact with the peripheral surface.

  In the circular tube cutting tool according to claim 3 of the present invention, a cutting blade is inserted into a long circular tube as far as the cutting portion, and is easily brought into contact with the inner peripheral surface. It can cut accurately in the vertical direction. Further, since the tool can be reduced in diameter, it can be applied to a small diameter circular pipe.

  In the circular tube cutting tool according to claim 4 of the present invention, the cutting blade is abutted at right angles to the inner peripheral surface of the circular tube, and the circular tube is accurately cut from the inside in a direction perpendicular to the cylindrical axis. can do.

  In the circular tube cutting tool according to claim 5 of the present invention, the shaft support portion and the slider can be easily rotated around the rotation center of the shaft as a whole by gripping and rotating the vicinity of both ends of the handle. Can be moved.

  Examples of the circular tube cutting tool according to the best mode of the present invention will be described below.

Example 1 of a circular tube cutting tool will be described with reference to FIGS. 1 to 4 (particularly corresponding to claims 1, 2, and 5).
1 (a) and 1 (b) are a front view and an enlarged view of the right side of Example 1 of the circular tube cutting tool according to the embodiment of the present invention, and FIGS. 2 (a) and 2 (b) respectively. It is the top view and bottom view of the circular tube cutting tool of Example 1. 3 (a) and 3 (b) are XZ planes passing through the rotation center of the shaft when the front portion of the shaft support portion is inserted into the circular tube in the circular tube cutting tool of the first embodiment. It is sectional drawing. In the present specification, the rotation center of the shaft is taken as the X axis, the positive direction and the negative direction are referred to as the front and the rear, respectively, and the positive direction and the negative direction of the Z axis are referred to as the upper and the lower, respectively. And
In the circular tube cutting tool 1a of the present embodiment, after the front portion of the shaft support portion 2 is inserted and arranged inside the circular tube, the cutting blade 3 abutted against the inner peripheral surface of the circular tube is manually moved to the shaft support portion. The circular tube is cut from the inside by rotating it by two.

As shown in FIGS. 1 and 2, the shaft support portion 2 has a vertically long box shape with an open upper surface, and a shaft 4 having ratchet-like threads is accommodated therein. Both ends of the shaft 4 are rotatably supported by a front surface 2a and a rear surface 2b (see FIG. 3) of the shaft support portion 2, and an end portion 4a (see FIG. 3) of the shaft 4 protruding rearward from the rear surface 2b. The grip 5 is fastened using a hexagon socket head bolt 5a. That is, when the grip 5 is held and rotated, the shaft 4 is configured to rotate inside the shaft support portion 2. In addition, small unevenness | corrugation (not shown) is formed in the outer peripheral surface of the substantially cylindrical grip 5 so that it may become slippery when it grasps with a hand.
In addition, the substantially square cylindrical slider 6 that is externally attached to the shaft support portion 2 can move only in the X-axis direction. Further, the slider 6 is urged forward by tension springs 7 and 7 connecting the lower surface of the shaft support portion 2 positioned in front of the slider 6. In addition, a stopper 8 is rotatably installed around a pivot 9a parallel to the Y axis inside a long square hole 6a drilled on the upper surface of the slider 6 along the X-axis direction. The lower end of the stopper 8 protrudes into the slider 6, and a claw portion 8 a (see FIG. 3) that can be engaged with the thread of the shaft 4 is formed. Further, the upper end of the stopper 8 protrudes outside the slider 6, and a compression spring 11 (see FIG. 3) is attached in the vicinity of the upper end. The compression spring 11 biases the stopper 8 in the direction of arrow A (see FIG. 3), and the claw portion 8a engages with the thread of the shaft 4.

A cutting blade support portion 12 and a roller support portion 13 are symmetrically disposed in front of the slider 6 with the shaft support portion 2 interposed therebetween, and the front portions of the cutting blade support portion 12 and the roller support portion 13 are proximal end portions. Are pivotally connected to the distal ends of a pair of link members 14a and 14a pivoted on the shaft support 4 via pivots 10a and 10b via pivots 10c and 10d, respectively. On the other hand, the rear portions of the cutting blade support portion 12 and the roller support portion 13 have pivots 10g, 10h at the distal ends of a pair of link members 14b, 14b whose base ends are pivotally mounted on the slider 6 via pivots 10e, 10f. Each is pivoted through.
The cutting blade 3 having a substantially disc shape is pivotally provided on the cutting blade support 12 via a pivot 9b in parallel with the rotation center 4b of the shaft 4. A pair of rollers 15 and 15 having a substantially cylindrical shape are pivoted on the roller support portion 13 via pivots 9c and 9c in parallel with the rotation center 4b of the shaft 4, respectively.

  In the circular tube cutting tool 1 a having such a structure, the grip 5 is rotated in a state where the claw portion 8 a of the stopper 8 is engaged with the thread of the shaft 4 to rotate the shaft 4 within the shaft support portion 2. When moved, the slider 6 has an action of moving forward or backward along the X axis. When the slider 6 moves forward, the links 14a and 14b rotate in the direction of the arrow B shown in FIG. 1A, so that the cutting blade support portion 12 and the roller support portion 13 are in the positive and negative directions of the Z axis. Move each one. When the slider 6 moves backward, the links 14a and 14b rotate in the direction opposite to the arrow B, so that the cutting blade support portion 12 moves in the negative direction of the Z axis and the roller support portion 13 moves to the Z direction. Move in the positive direction of the axis. Thereby, the diameter of the circumcircle 16 (refer FIG.1 (b)) formed with the cutting blade 3 and the rollers 15 and 15 changes. That is, in the circular tube cutting tool 1a of this embodiment, when the grip 5 is rotated in a state where the claw portion 8a of the stopper 8 is engaged with the thread of the shaft 4, the cutting blade support portion 12 and the roller support portion are supported. The distance between the portions 13 in the Z-axis direction changes, and as a result, the size of the circumscribed circle 16 formed by the cutting blade 3 and the rollers 15 and 15 changes. When the upper end of the stopper 8 is pushed in the positive direction of the X axis and the stopper 8 is rotated in the direction opposite to the arrow A around the pivot 9a against the force of the compression spring 11, the thread of the shaft 4 The engagement state of the claw portion 8a with respect to is released. In this case, since the slider 6 is urged by the tension spring 7 and moves forward, the cutting blade support portion 12 and the roller support portion 13 move away from each other in the Z-axis direction, and the circumscribed circle 16 becomes larger. . Further, the stopper 8 prevents the claw portion 8a from rotating in the direction opposite to the arrow A, thereby maintaining the engagement state. In the circular tube cutting tool 1a of the present invention, the lengths of the link members 14a and 14b are set so that the center of the circumscribed circle 16 always coincides with the rotation center 4b of the shaft 4.

A circumscribed circle 16 formed by the cutting blade 3 and the rollers 15 and 15 represents an inner diameter of a circular tube that can be cut using the circular tube cutting tool 1a. That is, the circular tube cutting tool 1a can be used when cutting a circular tube having an inner diameter that is larger than the minimum diameter of the circumscribed circle 16 and smaller than the maximum diameter. Hereinafter, a method of cutting a circular pipe using the circular pipe cutting tool 1a will be described with reference to FIG.
As shown in FIG. 3A, first, the X axis direction of the slider 6 is set so that the diameter of the circumscribed circle 16 (see FIG. 1B) is smaller than the inner diameter of the circular tube 17 to be cut. Is adjusted in advance, and the front portion of the circular tube cutting tool 1 a is inserted into the circular tube 17. Next, the upper end of the stopper 8 is pushed in the positive direction of the X axis, and the engagement between the claw portion 8a and the thread of the shaft 4 is released. As a result, the slider 6 moves forward while being urged by the tension spring 7, so that the link members 14a and 14b rotate in the direction of the arrow B, and the cutting blade support portion 12 and the roller support portion 13 are separated from each other in the Z-axis direction. To move. As a result, as shown in FIG. 3B, the cutting blade 3 and the rollers 15 and 15 abut against the inner peripheral surface 17 a of the circular tube 17. At this time, the rotation center 4 b of the shaft 4 coincides with the central axis of the circular tube 17. That is, in the circular tube cutting tool 1a of the present embodiment, the cutting edge 3 and the rollers 15, 15 are shorter in a shorter time than when the shaft 4 is rotated after the front portion is inserted into the circular tube 17. Can be brought into contact with the inner peripheral surface 17a.

In FIG. 3 (b), when the slider 6 is held and rotated together with the shaft support portion 2 around the rotation center 4 b of the shaft 4, the inner peripheral surface 17 a of the circular tube 17 is easily cut by the cutting blade 3. can do. At this time, the roller support portion 13 presses the rollers 15 and 15 disposed substantially symmetrically with the cutting blade 3 with the rotation center 4b interposed therebetween against the inner peripheral surface 17a, so that the cutting blade 3 is pressed against the inner peripheral surface 17a. It has the effect of preventing a decrease in contact pressure. In addition, when the contact pressure of the cutting blade 3 with the inner peripheral surface 17a is not appropriate, the grip 5 is rotated to change the distance between the cutting blade support portion 12 and the roller support portion 13 in the Z-axis direction. The contact pressure can be easily adjusted. Thereby, the circular pipe 17 can be cut in a stable state.
After the cutting operation of the circular tube 17 is completed, the cutting blade 3 and the roller 15 are rotated by rotating the grip 5 in a predetermined direction with the claw portion 8a of the stopper 8 engaged with the thread of the shaft 4. 15 can be detached from the inner peripheral surface 17a, and the circular tube cutting tool 1a can be easily taken out from the inside of the circular tube 17. Instead of rotating the grip 5, the upper end of the stopper 8 is pushed in the positive direction of the X axis to release the engagement between the claw portion 8 a and the thread of the shaft 4, and then the slider 6 is moved with respect to the shaft support portion 2. You may make it retreat relatively. According to this method, the cutting blade 3 and the rollers 15 and 15 can be separated from the inner peripheral surface 17a in a shorter time than the method of rotating the shaft 4.
Although the cutting blade 3 is not limited to a substantially disk shape, the inner peripheral surface of the circular tube 17 is obtained by holding the slider 6 and rotating the shaft support portion 2 about the rotation center 4 b of the shaft 4. Since 17a is cut by the cutting blade 3, it is desirable to have a rotatable disk shape in order to maintain a low friction with the inner peripheral surface 17a and achieve a long life.

Next, rotation assisting means used when the slider 6 is held and rotated together with the shaft support portion 2 will be described with reference to FIG.
FIGS. 4A to 4C are a front view, a plan view, and a left side view, respectively, of the rotation assisting means, and FIG. 4D is a circular tube cut of Example 1 showing a state where the rotation assisting means is mounted. It is an external view of the tool for operation. The components shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIGS. 4A to 4D, the rotation assisting means 20 has an insertion hole 18a for holding the slider 6 in a non-rotatable manner at one end, and a handle mounting portion 18b at the other end. Further, the slider holder 18 having a substantially rectangular tube shape, and a rod-like handle 19 installed on the handle mounting portion 18b. A recess 18c is formed in a part of the insertion hole 18a so as not to interfere with the stopper 8 when the slider 6 is inserted.
When the rotation assisting means 20 is attached to the circular tube cutting tool 1a, as shown in FIG. 4D, the slider 6 leaves the installation positions of the pivots 10e and 10f so that the operation of the link member 14b is not hindered. Together with the grip 5, it is inserted into the insertion hole 18a.
The rotation assisting means 20 having such a structure has an effect that the slider 6 and the shaft support portion 2 are simultaneously held by the slider holder 18. Therefore, in the state shown in FIG. 4D, by gripping and rotating the vicinity of both ends of the handle 19, the shaft support 2 and the slider 6 can be easily integrated around the rotation center 4b of the shaft 4. It can be rotated.
The shape of the handle 19 is not limited to a rod shape, and may be a ring shape or a rectangular shape.

  As described above, in the circular tube cutting tool 1a of the present embodiment, the cutting blade 3 is inserted into the circular tube 17 up to the cutting position and easily brought into contact with the inner peripheral surface 17a. It is possible to cut accurately in a direction perpendicular to. Further, since the structure is simple, it is easy to reduce the diameter of the tool. Therefore, even a small diameter circular tube can be applied.

  The present invention is not limited to the case shown in the present embodiment. For example, the number and installation location of the tension springs 7 are not limited to those shown in the present embodiment, and can be changed as appropriate. Further, instead of installing the tension spring 7 in front of the slider 6, it may be installed in the rear of the slider 6. Further, a compression spring can be used instead of the tension spring 7. The member that urges the slider 6 may be a so-called elastic member that generates a tensile force or a compressive force in accordance with elastic deformation, and thus a member other than a spring can be used. Further, the shape of the shaft support portion 2 is not limited to the box shape, and can be changed as appropriate. Furthermore, the slider 6 and the rotation assisting means 18 do not have to be rectangular. However, the insertion hole 18a of the rotation assisting means 18 needs to have a shape that can restrain the rotation of the slider 6.

A second embodiment will be described with reference to FIGS. 5 to 9 (particularly corresponding to claims 3 and 4).
FIGS. 5A to 5C are a front view, a plan view, and a left side view, respectively, of the auxiliary shaft connecting means of Example 2 of the circular tube cutting tool according to the embodiment of the present invention, and FIG. It is a GG arrow directional cross-sectional view in the same figure (b). FIG. 6A is a front view of the circular tube cutting tool of Example 2, and FIG. 6B is a partial front view of the circular tube cutting tool showing the slider and its vicinity when the auxiliary shaft connecting means is not mounted. And (c) is a cross-sectional view taken along line HH in FIG. (A), and (d) is a partially enlarged view of FIG. FIG. 7 is a cross-sectional view taken along the XZ plane passing through the rotation center of the shaft in FIG. FIGS. 8A and 8B are a front view and a side view of the auxiliary slider guide means, respectively. Further, FIG. 9A is an external view of the circular tube cutting tool of Example 2 showing a state where the auxiliary slider guide means is mounted, and FIGS. 9B and 9C are circular tubes of FIG. The state which inserted the front part of the shaft support part in the inside of a circular pipe in the cutting tool is shown. In FIGS. 9B and 9C, only the circular tube is shown in a sectional view. The constituent elements shown in FIGS. 1 to 4 are denoted by the same reference numerals, and the description thereof is omitted.
The circular tube cutting tool 1b according to the present embodiment is the same as the circular tube cutting tool 1a according to the first embodiment, in which the slider 6 is provided with a stopper 27 and an auxiliary shaft connecting means 26 and an auxiliary slider guide means 29. It is characterized by that.
As shown in FIGS. 5 to 7, the auxiliary shaft connecting means 26 has a thread having the same diameter and the same pitch as the shaft 4, and the front end 21a is inserted into the rear end of the shaft 4 via the hexagon socket bolt 5a. Auxiliary shaft 21 that is detachably connected and an auxiliary shaft support portion 22 that has a vertically long box shape with an open upper surface, accommodates auxiliary shaft 21 inside, and is rotatably supported by front surface 22a and rear surface 22b. And an auxiliary slider 23 that is inserted into the auxiliary shaft support portion 22 so as to be able to advance and retreat and that has an insertion hole 23a for the slider 6 and the grip 5 in front of the auxiliary shaft support portion 22, and an auxiliary shaft support. The auxiliary grip 25 is fastened to the rear end 21b of the auxiliary shaft 21 protruding rearward from the rear surface 22b of the portion 22 by using a screw 25a. That is, when the auxiliary grip 25 is rotated, the auxiliary shaft 21 rotates inside the auxiliary shaft support portion 22. When the auxiliary slider 23 is attached to the slider 6, the rotation center 21c of the auxiliary shaft 21 and the rotation center 4b of the shaft 4 are configured to coincide (see FIG. 7). In addition, small irregularities (not shown) are formed on the outer peripheral surface of the substantially cylindrical auxiliary grip 25 so as to prevent slipping when gripped with a hand.
In addition, an auxiliary stopper 24 is rotatably installed around a pivot 9d parallel to the Y axis inside a long rectangular hole 23d formed in the upper surface of the auxiliary slider 23 along the X-axis direction. . The lower end of the auxiliary stopper 24 protrudes into the auxiliary slider 23, and an auxiliary claw portion 24 a that can be engaged with the thread of the auxiliary shaft 21 is formed. Further, the upper end of the auxiliary stopper 24 protrudes to the outside of the auxiliary slider 23, and a compression spring 28 is attached in the vicinity of this upper end. That is, the auxiliary stopper 24 is urged in the direction of arrow A by the compression spring 28 so that the auxiliary claw portion 24a engages with the thread of the auxiliary shaft 21. Further, a through-hole 23b is provided on the side surface of the auxiliary slider 23 so as to be capable of engaging with the removal prevention tool 27 so as to communicate with the insertion hole 23a. A recess 23c is inserted into a part of the insertion hole 23a so that the slider 6 can be inserted while the upper end of the stopper 8 is pushed in the positive direction of the X axis to release the engagement between the claw portion 8a and the thread of the shaft 4. Is formed.
The removal prevention tool 27 includes a concave portion 6b formed on the side surface of the slider 6, a convex body 27a installed in the concave portion 6b so as to be able to protrude and retract from the opening 6c of the slider 6, and a convex shape that is also installed in the concave portion 6. It is comprised from the compression spring 27b which urges | biases the body 27a so that it can protrude from the opening part 6c (refer FIG.6 (b) thru | or (d)). In addition, since the opening part 6c is formed smaller than the convex body 27a, there is no possibility that the convex body 27a jumps out of the recessed part 6. 6C and 6D, for example, after the convex body 27a and the compression spring 27b are installed in the concave portion 6b, the plate-like separate member provided with the opening 6c is formed into the concave portion. It can be easily realized by attaching to the open end of 6b.
In the circular tube cutting tool 1b provided with the auxiliary shaft connecting means 26, as shown in FIG. 6A, the slider 6 leaves the installation positions of the pivots 10e and 10f so that the operation of the link member 14b is not hindered. Together with the grip 5, it is inserted into the insertion hole 23a. At this time, since the convex body 27 a of the removal prevention tool 27 is locked in the through hole 23 b of the auxiliary slider 23, the slider 6 is fixed to the auxiliary slider 23.

  In the circular tube cutting tool 1 b having such a structure, the auxiliary claw portion 24 a of the auxiliary stopper 24 is engaged with the thread of the auxiliary shaft 21 instead of the stopper 8 engaging with the thread of the shaft 4. Therefore, the auxiliary stopper 24 can be used in place of the stopper 8. In the circular tube cutting tool 1b, the front end 21a of the auxiliary shaft 21 is fitted in the hexagonal hole of the hexagonal hole bolt 5a fastened to the rear end of the shaft 4 with the auxiliary slider 23 mounted on the slider 6. Since the structure is a combination (see FIG. 7), the auxiliary shaft 21 has an action of rotating integrally with the shaft 4. In addition, when the auxiliary grip 25 is rotated in a state where the auxiliary claw portion 24 a of the auxiliary stopper 24 is engaged with the thread of the auxiliary shaft 21, the auxiliary shaft 21 rotates in the auxiliary shaft support portion 22. The auxiliary slider 23 has the action of moving forward or backward along the X axis. In addition, since the auxiliary shaft 21 has a thread having the same diameter and the same pitch as the shaft 4, the auxiliary shaft 21 can realize the same rotation state as the shaft 4. That is, according to the circular tube cutting tool 1b of the present embodiment, the same operation as that of the circular tube cutting tool 1a of the first embodiment can be performed at the rear position by the length of the auxiliary shaft 21. .

  As shown in FIGS. 8 and 9, the auxiliary slider guide means 29 is made of a frame-like member having an opening 30c, and is attached to the auxiliary slider 23 so as to be detachably attached to the auxiliary slider 23 at a predetermined interval. A pair of guide roller support portions 31, 31 disposed between 30 a, 30 b and the fixtures 30 a, 30 b and symmetrically with the auxiliary slider 23 interposed therebetween, and the guide roller support portions 31, 31, A pair of guide rollers 32, 32 pivotally supported via pivots 9e, 9e in parallel to the rotation center 21c, and four guide links connecting the guide roller support portions 31, 31 to the fixtures 30a, 30b. And a member 33. The four guide link members 33 each have a base end portion pivoted on the fixtures 30a and 30b via the pivot 34a, and a tip end portion pivoted on the guide roller support portion 31 via the pivot 34b. Further, the fixtures 30 a and 30 b can be fixed to the auxiliary slider 23 using screws 35. That is, in the state where the auxiliary slider guide means 29 is attached to the auxiliary slider 23, the diameter of the circumscribed circle 36 formed by the four guide rollers 32 changes when the distance between the attachment tools 30a and 30b is changed. In the auxiliary slider guide means 29, the length of the link member 34 is set so that the center of the circumscribed circle 36 always coincides with the rotation center 21c of the auxiliary shaft 21.

The operation procedure of the auxiliary slider guide means 29 will be described with reference to FIG.
As shown in FIG. 9A, in the circular tube cutting tool 1 b in which the auxiliary slider guide means 29 is mounted on the auxiliary slider 23, only the fixture 30 a is fixed to the auxiliary slider 23 using a screw 35. Next, the front portion of the circular tube cutting tool 1b is inserted into the circular tube 17 until it reaches a position where the cutting blade 3 can come into contact with the cut portion of the inner peripheral surface 17a. Next, the upper end of the auxiliary stopper 24 is pushed in the positive direction of the X axis, and the engagement between the auxiliary claw portion 24a and the thread of the auxiliary shaft 21 is released. Accordingly, since the auxiliary slider 23 moves forward together with the slider 6 biased by the tension spring 7, the cutting blade support portion 12 and the roller support portion 13 move away from each other in the Z-axis direction. As shown in (b), the cutting edge 3 and the rollers 15, 15 abut on the inner peripheral surface 17 a of the circular tube 17. In this state, the fixture 30b is advanced along the auxiliary slider 23, and the four guide rollers 32 are brought into contact with the inner peripheral surface 17a of the circular tube 17. Thereafter, the fixture 30 b is fixed to the auxiliary slider 23 using the screw 35. As a result, as shown in FIG. 9 (c), the circular tube cutting tool 1 b is Y− against the inner peripheral surface 17 a of the circular tube 17 by the cutting blade 3, the rollers 15, 15 and the four guide rollers 32. The position in the Z plane is fixed. That is, the auxiliary slider guide means 29 has an action of accurately aligning the rotation center 4b of the shaft 4 and the rotation center 21c of the auxiliary shaft 21 with the cylindrical axis of the circular tube 17. In this case, the cutting edge 3 always comes into contact with the inner peripheral surface 17a at a right angle. Therefore, the circular tube 17 can be accurately cut in a direction perpendicular to the cylindrical axis. Note that the rotation assisting means 20 described in the first embodiment forms the slider holder 18 so that the auxiliary slider 23 can be inserted in place of the slider 6, so that the circular tube cutting tool 1b of the present embodiment is used. Can be used in the same manner.

  As described above, in the circular tube cutting tool 1b of the present embodiment, even when the circular tube 17 is long, the cutting blade 3 is inserted to the cutting portion and easily brought into contact with the inner peripheral surface 17a. It can be cut accurately in a direction perpendicular to the cylindrical axis. Further, since the structure of the auxiliary shaft connecting means 26 and the auxiliary slider guide means 29 is simple, the diameter of the tool can be reduced. Therefore, the present invention can also be applied to the case of cutting the small diameter circular tube 17.

  As described above, the inventions described in claims 1 to 5 can be applied when it is necessary to cut the circular tube from the inside while being installed.

(A) And (b) is the front view and enlarged view of the right side surface of Example 1 of the circular tube cutting tool which concerns on embodiment of this invention. (A) And (b) is the top view and bottom view of the circular tube cutting tool of Example 1, respectively. (A) And (b) is sectional drawing by the XZ plane which passes along the rotation center of a shaft at the time of inserting the front part of a shaft support part in the inside of a circular tube in the circular tube cutting tool of Example 1. FIG. . (A) thru | or (c) is the front view, top view, and left view of a rotation assistance means, respectively, (d) is the circular tube cutting tool of Example 1 which shows the state with which the rotation assistance means was mounted | worn. FIG. (A) thru | or (c) are the front views, top views, and left view of the auxiliary shaft connection means of Example 2 of the circular tube cutting tool which respectively concerns on embodiment of this invention, (d) is the figure. It is a GG arrow directional cross-sectional view in (b). (A) is a front view of the circular tube cutting tool of Example 2, (b) is a partial front view of the circular tube cutting tool showing the slider and its vicinity when the auxiliary shaft connecting means is not mounted, (C) is the HH arrow directional cross-sectional view in the figure (a), (d) is the elements on larger scale of the figure (c). It is sectional drawing by the XZ plane which passes along the rotation center of a shaft in Fig.6 (a). (A) And (b) is the front view and side view of an auxiliary slider guide means, respectively. (A) is an external view of the circular tube cutting tool of Example 2 showing a state where the auxiliary slider guide means is mounted, and (b) and (c) are the circular tube cutting tool of FIG. The state which inserted the front part of the shaft support part in the inside of a circular pipe is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b ... Circular pipe cutting tool 2 ... Shaft support part 2a ... Front face 2b ... Rear face 3 ... Cutting blade 4 ... Shaft 4a ... End part 4b ... Center of rotation 5 ... Grip 5a ... Hex socket head bolt 6 ... Slider 6a ... Square hole 6b ... Recess 6c ... Opening 7 ... Tension spring 8 ... Stopper 8a ... Claw 9a-9e ... Pivot 10a-10h ... Pivot 11 ... Compression spring 12 ... Cutting blade support 13 ... Roller support 14a, 14b ... Link Member 15 ... Roller 16 ... circumscribed circle 17 ... circular pipe 17a ... inner peripheral surface 18 ... slider holder 18a ... insertion hole 18b ... handle mounting part 18c ... concave part 19 ... handle 20 ... rotation assist means 21 ... auxiliary shaft 21a ... Front end 21b ... Rear end 21c ... Center of rotation 22 ... Auxiliary shaft support 22a ... Front 22b ... Rear 23 ... Auxiliary slider 23a ... Insertion hole 23b ... Through hole 23c ... Concave 23d ... Square hole 24 ... Auxiliary stopper 24a ... Auxiliary claw 25 ... Auxiliary grip 25a ... Screw 26 ... Auxiliary shaft connecting means 27 ... Detachment prevention device 27a ... Convex body 27b ... Compression spring 28 ... Compression spring 29 ... Auxiliary slider guide Means 30a, 30b ... fixture 30c ... opening 31 ... guide roller support 32 ... guide roller 33 ... guide link member 34a, 34b ... pivot 35 ... screw 36 ... circumscribed circle

Claims (5)

  A shaft having a thread, a shaft support that rotatably supports the shaft, a slider that is externally inserted into the rear half of the shaft support, and a claw that can be engaged with the thread are formed. A stopper, a grip installed at the end of the shaft protruding rearward from the shaft support, and a cutting blade support and a roller support arranged symmetrically with the shaft support in front of the slider And a roller supported in parallel with the rotation center of the shaft by the roller support portion, and a central portion is supported in parallel with the rotation center of the shaft by the cutting blade support portion. A pair of first link members each having a cutting edge, a distal end portion pivoted at the front portion of the cutting blade support portion or the roller support portion, and a proximal end portion pivoted at the shaft support portion; Part A pair of second link members pivotally provided at the rear part of the cutting blade support part or the roller support part and having a base end part pivotally provided on the slider, and the stopper is provided with respect to the screw thread. A circular tube cutting tool, wherein the claw portion is attached to the slider so as to be freely engageable.   2. The circular tube cutting tool according to claim 1, wherein the slider is urged along a rotation center of the shaft by an elastic member connecting the shaft support portion.   An auxiliary shaft having a thread having the same diameter and the same pitch as the shaft, the front end of which is detachably connected to the rear end of the shaft, and an auxiliary shaft support portion that rotatably supports the auxiliary shaft; An auxiliary slider that is inserted in the auxiliary shaft support portion so as to be able to advance and retreat, and has an insertion hole for the slider and the grip in front of the auxiliary shaft support portion, and a side surface of the auxiliary slider with the insertion hole A through hole provided in communication and an auxiliary claw portion engageable with a thread of the auxiliary shaft are formed, and the auxiliary claw portion can be freely engaged with the auxiliary slider with respect to the screw thread of the auxiliary shaft. An auxiliary shaft comprising an auxiliary stopper to be attached and an auxiliary grip attached to the rear end portion of the auxiliary shaft protruding rearward from the auxiliary shaft support portion Comprising a connection means, said slider circular tube cutting tool according to claim 1 or claim 2, characterized in that it comprises a preventer omission is engaged with the through hole of said auxiliary slider.   A pair of attachments that are detachably attached to the auxiliary slider at a predetermined distance from each other, and a pair of guide rollers that are disposed between the pair of attachments and symmetrically across the auxiliary slider A support portion, a guide roller that is pivotally supported by the guide roller support portion in parallel to the rotation center of the auxiliary shaft, a distal end portion pivotally connected to one end of the guide roller support portion, and a base end portion 4. The circular tube cutting tool according to claim 3, further comprising auxiliary slider guide means provided with four guide link members pivoted on the fixture. An insertion hole for holding the slider in a non-rotatable manner at one end and a slider holding tool provided with a handle attaching portion at the other end, and a rotation assisting means comprising a handle installed at the handle attaching portion. The circular tube cutting tool according to any one of claims 1 to 3, further comprising a cutting tool.