JP2017100267A - Holding member of pastic pipe end part and cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic pipe end part holding member which has a simple structure and can securely hold an end part outer peripheral surface of a plastic pipe even when the plastic pipe has a small bore diameter, and to provide a cutting method of the plastic pipe end part using the holding member.SOLUTION: A holding member 21 for holding an end part of a plastic pipe has: a base shaft body 22 having an inner hole 22a provided with a female screw; and a contact body 23 which is integrated with the base shaft body 22 through a connection body 24. The connection body 24 may elastically deform in a centripetal direction toward a center of the plastic pipe 5, and an outer peripheral surface of the contact body 23 elastically contacts with an inner peripheral surface of the plastic pipe. The holding member 21 holds an end part of the plastic pipe 5 and an end part outer peripheral surface of the plastic pipe 5 is cut with a bit 15 of a cutting jig 10.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a holding member for holding an end portion of a plastic tube when the outer peripheral surface of the end portion of the plastic tube is cut. More specifically, the present invention relates to a holding member used when cutting an outer peripheral surface of a plastic pipe end before fusing the plastic pipe to a joint. The present invention also relates to a method of holding the plastic pipe end by the holding member and cutting the outer peripheral surface of the plastic pipe end.

Conventionally, plastic pipes are used for water pipes and gas pipes. An electrofusion joint (hereinafter referred to as an EF joint) using an electrofusion system is used for connecting the plastic pipes.

  In the EF joint, coiled heating wires are embedded in the inner peripheral surface of the joint plastic pipe, and the ends of the two plastic pipes to be connected are inserted from both ends of the EF joint, An electric current is passed to generate heat, and the inner surface of the EF joint and the outer surface of the plastic pipe are melted and connected.

  As conventional techniques for cutting the outer peripheral surface of an end portion of a plastic pipe, there are JP-A-5-104301 “Plastic pipe cutting tool” and JP-A 2011-36928 “Cutting tool”.

JP-A-5-104301 JP2011-36928

  In JP-A-5-104301, a holding member inserted into a plastic tube has a conical tapered portion. However, in this holding member, the length of scraping changes according to the inner diameter of the plastic tube.

  In JP 2011-36928 A, a holding member inserted into a plastic tube is provided with a mechanism so as to be able to cope with various diameters. However, a holding member that holds a plastic tube having a small diameter of 13A to 20A. Then, it is very difficult to provide such a mechanism portion, and the workability of insertion into the plastic pipe is greatly impaired.

  The present invention has a simple configuration and uses a holding member for a plastic tube end portion that can easily and firmly hold the outer peripheral surface of the end portion, even if the plastic tube has a small diameter, and the holding member. An object of the present invention is to provide a method for cutting a plastic pipe end.

  The holding member at the end of the plastic tube of the present invention includes a base shaft body through which an inner hole in which a female screw is engraved is formed, and a contact body integrated with the base shaft body via a connecting body The corresponding body is elastically displaceable in the centripetal direction toward the center of the plastic tube, and the outer peripheral surface of the corresponding body is elastically brought into contact with the inner peripheral surface of the plastic tube. It is characterized by.

  In one aspect of the present invention, the base shaft body is cylindrical, and the contact body surrounds the tip end side of the base shaft body coaxially, and a slit parallel to the axial direction of the base shaft body is provided in the contact body. The side opposite to the slit across the axis of the contact body is connected to the base shaft body via the connecting body.

  In another aspect of the present invention, the base shaft body is cylindrical, and a plurality of connecting bodies project from the outer peripheral side of the distal end surface of the base shaft body in a direction parallel to the axial direction of the base shaft body, The coupling bodies are arranged at intervals in the direction around the axis of the base shaft body, and each coupling body can be elastically deformed in the centripetal direction at each distal end. The contact body protrudes in the radial direction.

  The plastic pipe end outer peripheral surface cutting method according to the present invention includes a jig body, a male screw rod projecting from the jig body, and an arm extending from the jig body along the male screw rod. , A method of cutting the outer peripheral surface of the plastic pipe end using a cutting jig having a cutting tool provided on the tip side of the arm, the plastic pipe end is held by the holding member of the present invention, The male screw rod is screwed into the inner hole of the base shaft body of the holding member, the cutting tool is pressed against the outer peripheral surface of the plastic tube end, the jig body is rotated around the axis, and is screwed. Is moved in a spiral direction along the outer peripheral surface of the plastic tube to cut the outer peripheral surface of the end portion of the plastic tube.

  In one aspect of the present invention, the arm has a proximal end pivotally attached to the jig body by a support shaft, and the cutting jig has a spring for biasing the arm in a centripetal direction. Are provided, and the cutting tool is pressed against the outer peripheral surface of the plastic tube by the biasing force of the spring.

  The holding member of the present invention is inserted into the end portion of the plastic tube by compressing the contact body. When the compression / shrink force is released, the contact body elastically adheres to the inner peripheral surface of the plastic tube, whereby the end portion of the plastic tube is held by the holding member. Since the circumference of the contact body is large, the end portion of the plastic tube is firmly held.

  The holding member of the present invention has a simple configuration, and can easily hold the abutting body by inserting it into a small diameter plastic tube.

  After holding the end portion of the plastic tube using the holding member of the present invention, the male screw rod of the cutting jig is screwed into the inner hole of the base shaft body of the holding member. Then, the cutting tool arm tip is brought into contact with the outer peripheral surface of the plastic pipe end, the cutting jig is rotated, and the cutting tool is moved in the spiral direction to cut the outer peripheral surface of the plastic pipe.

  In the cutting method of the present invention, it is preferable to bias the arm with a spring. By doing so, since the cutting tool is pressed against the outer peripheral surface of the plastic pipe end with a constant pressing force, the outer peripheral surface of the plastic pipe end can be cut uniformly.

It is a perspective view of the holding member concerning an embodiment. It is the II-II sectional view taken on the line of FIG. It is a perspective view which shows the insertion method of the holding member to a plastic pipe edge part. It is the IV-IV sectional view taken on the line of FIG. It is the VV sectional view taken on the line of FIG. It is the VI-VI sectional view taken on the line of FIG. It is a perspective view of the holding member concerning another embodiment. It is a front view of the holding member of FIG. It is the IX-IX sectional view taken on the line of FIG. It is sectional drawing which shows the insertion state of the holding member to a plastic pipe edge part. It is sectional drawing which shows the cutting method of a plastic pipe edge part.

  Hereinafter, embodiments will be described with reference to the drawings.

  1 to 6 show a holding member 1 according to the first embodiment. The holding member 1 includes a thick cylindrical base shaft body 2, a thin cylindrical contact body 3 with a single slit 3a surrounding the outer periphery of the distal end side of the base shaft body 2, and the base body 2 It has the connection body 4 which connects the contact body 3. The inner hole 2a of the base shaft body 2 penetrates from the rear end to the front end of the base shaft body 2, and a female screw 2b is engraved on the entire inner peripheral surface thereof. The base shaft body 2 has a thickness (difference between an inner diameter (radius) and an outer diameter (radius)) larger than the thickness of the contact body 3, and strength and rigidity that do not substantially deform when the outer peripheral surface of the plastic pipe is cut. have.

  The contact body 3 surrounds the outer periphery on the distal end side of the base shaft 2 coaxially, and the diameter of the contact body 3 is reduced between the inner peripheral surface of the contact body 3 and the outer peripheral surface of the base shaft 2. There is a predetermined gap allowing deformation. The contact body 3 is provided with a single slit 3a extending in a direction parallel to the axial direction so as to be longitudinally cut from the front end to the rear end. Since the abutting body 3 has a thin cylindrical shape, the abutting body 3 can be elastically deformed in the reduced diameter direction by expanding and contracting the width w of the slit 3a.

  A connecting body 4 is arranged on the opposite side of the slit 3a across the axis of the contact body 3. The connecting body 4 extends in a direction parallel to the axial direction of the contact body 3 from the front end to the rear end of the contact body 3.

  The holding member 1 is integrally formed of synthetic resin or metal including the base shaft body 2, the contact body 3, and the connecting body 4.

  The plastic tube 5 held by the holding member 1 has an inner diameter slightly smaller than the outer diameter of the contact body 3. In order to hold the plastic tube 5 by the holding member 1, as shown in FIG. 3A, the contact body 3 is pressed and contracted in the radial direction with a fingertip or a tool so as to narrow the slit width w of the contact body 3. Insert into tube 5. When the pressing force of the abutment body 3 is released, the abutment body 3 is pressed against the inner peripheral surface of the plastic tube 5 to return to its original diameter by its own elastic force. One end of the plastic tube 5 is held as shown in FIGS. In this holding member 1, the whole or most of the outer peripheral surface of the contact body 3 is in close contact with the inner peripheral surface of the plastic tube 5, so that the end of the plastic tube 5 is firmly held by the holding member 1.

  FIG. 11 shows an example of a method of cutting the outer peripheral surface of the end portion of the plastic tube 5 held by the holding member 1 with the cutting jig 10. The cutting jig 10 includes a jig main body 11, a male screw rod 12 projecting forward from the jig main body 11, and a proximal end thereof rotated by a support shaft 13 with respect to the jig main body 11. A plurality of (usually 2 to 4) arms 14 that are freely attached and extend along the male screw rod 12 and springs (not shown) that bias the distal ends of the arms 14 toward each other in a centripetal direction. ) And a cutting tool (cutting blade) 15 provided on the centripetal direction side of the tip of each arm 14. In addition, although said spring is the helical spring wound around the spindle 13, it is not limited to this. A male screw is engraved on the outer peripheral surface of the male screw rod 12.

  When the male screw rod 12 is screwed into the inner hole 2a of the base shaft body 2 of the holding member 1 and the jig body 11 is rotated in the direction of the arrow θ by a motor (not shown), the male screw rod 12 is moved to the left in FIG. Screw on. When the male screw rod 12 is screwed by a predetermined length, the cutting tool 15 is brought into contact with the outermost surface of the plastic tube 5 as shown in FIG.

  When the jig body 11 is further rotated in the θ direction from this state, the male screw rod 12 further advances, and the cutting tool 15 moves in the spiral direction while cutting the outer peripheral surface of the plastic tube 5. The jig body 11 is rotated in the θ direction until a necessary range near the end of the plastic tube 5 is cut by the cutting tool 15. Thereafter, the jig main body 11 is rotated in the anti-θ direction, the male screw rod 12 is retracted in the right direction in FIG. 11, the male screw rod 12 is detached from the inner hole 2a, and the cutting jig 10 and the plastic tube 5 are moved. And are separated.

  Since the holding member 1 holds the end portion of the plastic tube 5 firmly, when the cutting jig 10 is rotated, the cutting jig 10 does not wobble, and the cutting tool 15 is not pressed. It moves in the spiral direction while being pressed against the outer peripheral surface of the plastic tube 5 by the pressure F. Thereby, the outer peripheral surface of the end portion of the plastic tube 5 is cut at a specified depth.

  7 to 10 show a holding member 21 according to the second embodiment. The holding member 21 includes a thick cylindrical base shaft body 22, a plurality of pieces (in this embodiment, four pieces) of connecting bodies 24 projecting from the outer periphery of the base shaft body 22, and each connecting body 24. And an abutment body 23 provided on the outer peripheral surface of the tip portion. The inner hole 22a of the base shaft body 22 penetrates from the rear end to the front end of the base shaft body 22, and a female screw 22b is engraved on the entire inner peripheral surface thereof. The base body 22 has a thickness (difference between an inner diameter (radius) and an outer diameter (radius)) larger than the thickness of the connecting body 24, and has a strength and rigidity that does not substantially deform when the outer peripheral surface of the plastic pipe is cut. Have.

  Each connection body 24 is arranged at intervals in the circumferential direction on the distal end side of the base shaft body 22, and the distal end side thereof can be elastically displaced in the centripetal direction. The contact body 23 is provided in a stepped shape that protrudes from the outer peripheral surface of the connection body 24. The central angle a (FIG. 8) around the axis of the base shaft 22, which is the circumferential extension range of one piece of the connecting body 24, is 10 to 170 °, particularly 30 to 120 °, particularly 60 to 90 °. preferable. The number of the contact bodies 23 is preferably large in order to hold the end portion of the plastic tube 5 firmly and with an equal force. However, from the viewpoint of manufacturing the holding member 21, if the number of the contact bodies 23 is too large, the number of the contact bodies 23 is generally 2 to 12 because the number of processes is complicated and complicated. Among these, 3 to 9, particularly 4 to 7 are preferable. Further, the central angle a (FIG. 8) around the axis of the base shaft 22 in the contact body 23 may be equal or non-uniform, but the end of the plastic tube 5 is firmly held with equal force. In order to do so, it is preferable to be nearly equal. In FIG. 8, the center angles a are substantially equal.

  The holding member 21 is integrally formed of synthetic resin or metal including the base shaft body 22, the contact body 23 and the connecting body 24.

  The inner diameter of the plastic tube 5 held by the holding member 21 is slightly smaller than the diameter of the circumscribed circle of the contact body 23. In order to hold the plastic pipe 5 by the holding member 21, as shown in FIG. 10, the connecting body 24 is pushed and bent in the centripetal direction, and the contact body 23 is inserted into the plastic pipe 5. When the compression force of the connecting body 24 is released, the contact body 23 is pressed against the inner peripheral surface of the plastic tube 5 so that the connecting body 24 returns to its original diameter by its own elastic force. One end of the plastic tube 5 is held. The holding member 21 has the whole or most of the outer peripheral surface of the contact body 23 in close contact with the inner peripheral surface of the plastic tube 5 and the total peripheral length of the four pieces of the contact body 23 is long. Are firmly held by the holding member 21.

  The method of cutting the outer peripheral surface of the end portion of the plastic tube 5 held by the holding member 21 with the cutting jig 10 is the same as that shown in FIG.

  That is, the male screw rod 12 is screwed into the inner hole 22a of the base shaft 2 of the holding member 21, and the jig body 11 is rotated by a motor (not shown) in the direction of the arrow θ so that the male screw rod 12 is screwed by a predetermined length. The bit 15 is brought into contact with the outermost peripheral surface of the plastic tube 5.

  From this state, the jig main body 11 is further rotated in the θ direction, the male screw rod 12 is further screwed, and the cutting tool 15 is moved in the spiral direction while cutting the outer peripheral surface of the plastic tube 5. The jig body 11 is rotated in the θ direction until a necessary range near the end of the plastic tube 5 is cut by the cutting tool 15. Thereafter, the jig body 11 is rotated in the anti-θ direction, the male screw rod 12 is moved backward in the right direction in FIG. 11, the male screw rod 12 is detached from the inner hole 22a, and the cutting jig 10 and the plastic tube 5 are removed. And are separated.

  Also in this embodiment, since the holding member 21 holds the end of the plastic tube 5 firmly, the cutting jig 10 does not wobble when the cutting jig 10 is rotated. Moves in the spiral direction while being pressed against the outer peripheral surface of the plastic tube 5 with a constant pressing force F. Thereby, the outer peripheral surface of the end portion of the plastic tube 5 is cut at a specified depth.

  The above-described embodiment is an example of the present invention, and the present invention may be configured other than illustrated.

DESCRIPTION OF SYMBOLS 1,21 Holding member 2,22 Base shaft body 3,23 Contact body 3a Slit 4,24 Connection body 5 Plastic pipe 10 Cutting jig 11 Jig body 12 Male screw rod 14 Arm 15 Bit

Claims (5)

A holding member for holding the end of the plastic tube,
A base shaft body through which an inner hole engraved with a female screw is formed;
A contact body integrated with the base shaft body via a connecting body,
The plastic pipe end characterized in that the contact body is elastically displaceable in a centripetal direction toward the center of the plastic tube, and an outer peripheral surface of the corresponding contact body is elastically contacted with an inner peripheral surface of the plastic tube. Part holding member. In Claim 1, the base shaft body is cylindrical, and the contact body surrounds the tip end side of the base shaft body coaxially,
The contact body is provided with a slit parallel to the axial direction of the base shaft body,
A holding member for an end portion of a plastic tube, wherein the side opposite to the slit across the axis of the contact body is connected to the base shaft body via the connecting body. In Claim 1, the base shaft body is cylindrical, and a plurality of connecting bodies project from the outer peripheral side of the distal end surface of the base shaft body in a direction parallel to the axial direction of the base shaft body,
Each coupling body is arranged at intervals in the direction around the axis of the base shaft body,
Each connecting body is elastically deformable in the centripetal direction at the tip side,
A holding member for an end portion of a plastic pipe, wherein the contact body projects radially from the outer peripheral surface on the tip side of each connecting body. A jig main body, a male screw rod projecting from the jig main body, an arm extending from the jig main body along the male screw rod, and a cutting tool provided on the tip side of the arm A method of cutting an outer peripheral surface of a plastic pipe end using a cutting jig,
The plastic pipe end is held by the holding member according to any one of claims 1 to 3,
The male screw rod is screwed into the inner hole of the base shaft body of the holding member, the cutting tool is pressed against the outer peripheral surface of the plastic tube end, the jig body is rotated around the axis, and is screwed. A method for cutting an outer peripheral surface of a plastic pipe end, wherein the outer peripheral surface of the plastic pipe end is cut by moving the screw along the outer peripheral surface of the plastic pipe in a spiral direction. In Claim 4, the said arm is attached to the above-mentioned jig main part by the support axis so that rotation is possible,
The cutting jig is provided with a spring for urging the arm in the centripetal direction,
A cutting method of a peripheral surface of a plastic pipe, wherein the cutting tool is pressed against the outer peripheral surface of the plastic pipe by a biasing force of the spring.

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