JPH07178480A - Device for forming tube end swollen part - Google Patents

Abstract

PURPOSE:To provide a device for forming a tube end swollen part where the working efficiency is excellent, and no deformation or damages are generated in the swollen part to be formed. CONSTITUTION:A forming ring 6 made of elastic material is mounted in an annular groove 13 to be formed between a movable piece 3 and a fixed piece 5, and the end part of a tube where an annular swollen part is formed is fitted thereto. The outer circumference of the tube is held by a plurality of chucks 7. Forming grooves 7a are formed in the circumferential direction at the position opposite to the forming ring 6 on the inner circumferential surface of each chuck 7, and when the movable piece 3 is brought close to the fixed piece 5 through a shaft 2 by a driving means 11, the width of the annular groove 13 is reduced, and the forming ring 6 is elastically deformed to be swollen outward of the annular groove 13. Then, the inner circumferential surface of the tube is pushed toward the forming groove 7a side to form the swollen part along the shape of the forming groove 7a at the tube end part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe end bulge used for forming an annular bulge portion which engages with a joint member on the outer periphery of the pipe end when connecting water supply pipes of factories and buildings. A part forming device.

[0002]

2. Description of the Related Art Conventionally, in a joint used for piping, a joint portion is fixed to one pipe end by welding or the like, and an annular bulging portion is provided on the outer periphery near the pipe end of the other pipe. There is a structure in which both pipes are connected by engaging the bulging portion with the bulging portion, and a device for forming the bulging portion having such a shape is provided by Japanese Patent Laid-Open No. 59-197322. There is something.

FIG. 5 is a cross-sectional view showing the structure of the piston rod 21. A rubber retainer 23 is fixed to the tip of a piston rod 21 operated by pressure oil via a connecting pipe 22.
An annular expanded rubber 24 and a rubber receiver 25 are fitted around the outer circumference. The rubber receiver 25 surrounds the connecting pipe 22 and abuts on an expanding tube 26 attached to a cylinder (not shown),
The expanded rubber 24 is supported by being sandwiched between a rubber presser 23 and a rubber receiver 25.

Preparation for forming a bulge portion by fitting a pipe end portion 28 having a nut 27 fitted on the outer periphery thereof over the rubber receiver 25 and the rubber retainer 23, and screwing the nut 27 onto the pipe expanding cylinder 26. Is completed, the piston rod 21 is operated and the rubber retainer 2
When 3 is brought closer to the rubber receiver 25, the tube expansion rubber 24 bulges outward in the radial direction, and the tube wall is extruded into an annular recess having a mountain-shaped cross section formed by the tube expansion tube end surface inner periphery 26a and the nut inner peripheral surface 27a. As shown in FIG. 5, a bulging portion 29 having a mountain-shaped cross section is formed.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the apparatus of No. 97322, the nut needs to be attached to and detached from the tube for each operation, and when the nut is removed from the pipe after the bulging portion is formed, the end where the bulging portion is formed is formed. There is a problem that work efficiency decreases because the nut cannot be removed unless the nut is moved to the end opposite to the part.

Further, when the bulging portion is formed, the outer peripheral surface of the tube end is strongly pressed against the nut and the inner peripheral surface of the tube.
When removing the tube end, there is a problem that the nut screwed to the tube is difficult to rotate due to friction with the bulging portion of the tube end, and labor is required for removal. Moreover, in this case, since the torsional force acts on the bulging portion due to the rotation of the nut, the bulging portion may be deformed, or the rotating nut may be rubbed and damaged.

The present invention solves such a problem, and provides a pipe end bulging portion forming device which has good working efficiency and does not cause deformation or damage to the bulging portion formed. The purpose is to

[0008]

The pipe end bulging portion forming apparatus of the present invention for the above object has a movable piece fixed to the front end portion of a shaft and having a cylindrical outer peripheral surface. It is formed between a fixed piece having a cylindrical outer peripheral surface of the same diameter and having a front end surface opposed to a rear end surface of the movable piece and fitted into the shaft, and an end surface of the movable piece and an end surface of the fixed piece which are opposed to each other. An elastically deformable molding ring fitted in the annular groove, and a plurality of circumferential molding grooves are formed on the inner surface of each of a plurality of molding rings arranged around the molding ring and facing the molding ring, and the outer front end portions of the molding rings are formed. A chuck having an inclined surface inclined forward, a chuck support surface that supports the rear end of each chuck so that the front end side of each chuck can be expanded and contracted in the radial direction, and a fixed piece support surface that supports the fixed piece. Is formed on the front At the same time, a guide hole through which the shaft is slidably inserted is formed, and a chuck holder having a male screw formed on the outer peripheral surface having a concentric contour with the guide hole, and the front end side of each chuck is constantly expanded. Direction and elastic body and female screw which surrounds the outside of each chuck and is screwed to the male screw of the chuck holder are formed on the inner surface of the rear part, and the tapered surface that abuts on each inclined surface of the chuck and expands backward Is provided with a substantially hollow cylindrical chuck opening / closing ring formed on the inner peripheral surface of the front end portion, and a drive means for moving the shaft in the axial direction with respect to the chuck holder to move the movable piece toward and away from the fixed piece. is there.

[0009]

When the chuck opening / closing ring is rotated with respect to the chuck holder and moved forward, the inclined surface of each chuck is unconstrained from the tapered surface of the opening / closing ring and the front end side of each chuck is expanded by the urging force of the elastic body. Open.

From the front of the apparatus, the tube end of the tube forming the bulge is fitted and positioned over the movable piece and the fixed piece.

Next, when the chuck opening / closing ring is rotated with respect to the chuck holder in the opposite direction and retracted, the tapered surface presses the inclined surface of each chuck toward the center, and the chuck resists the urging force of the elastic body. The closed tube end is then clamped between each chuck, the movable piece and the fixed piece.

In this state, when the drive means is operated to pull the shaft rearward, the movable piece approaches the fixed piece and the molding ring mounted in the annular groove formed between the two moves forward and backward. Is compressed and deformed, and bulges outward in the radial direction. The bulging forming ring presses the inner peripheral surface of the pipe to the outside, but the inner peripheral surface of each chuck at the position facing the forming ring has a forming groove in the circumferential direction. The bulging portion is formed in the shape of the molding groove by being pushed into the molding groove by the molding ring.

When the shaft is advanced to its original position, the movable piece is separated from the fixed piece, so that the pressure on both end surfaces of the molding ring is released and the elastic restoring force restores the original shape so that the outer peripheral surface is inside the pipe end. Separated from the peripheral surface into the annular groove.

Next, the chuck opening / closing ring is rotated with respect to the chuck holder and moved forward to expand each chuck, and the tube end portion having the bulged portion is removed from the apparatus.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pipe end bulging portion forming apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of a tube end bulging portion forming device of the present invention. A tube end bulging portion forming device 1 has a shaft 2 arranged at the center thereof. A male screw 2a is formed near the front end of the shaft 2, and a movable piece 3 is fixed to this portion.

A female screw 3a is formed at the center of the movable piece 3, and the lock nut 4 is screwed onto the male screw 2a.
Is fixed to the front end of the shaft 2 so that the front-rear position can be adjusted. The outer peripheral surface 3b of the movable piece 3 is formed into a cylindrical surface and has an outer diameter adapted to the inner diameter of the pipe end to be molded. Further, a small diameter portion 3c is formed on the rear portion of the movable piece 3. The outer periphery of the front end surface of the movable piece 3 is chamfered 3d so that the tube end can be easily fitted.

A fixed piece 5 is arranged behind the movable piece 3. The fixed piece 5 is formed with a hole 5a through which the shaft 2 is inserted at the center and is slidably fitted to the shaft 2 adjacent to the fixed piece 5. A cylindrical recess 5b into which the small diameter portion 3c of the movable piece 3 can be fitted is formed on the front end surface thereof. The outer peripheral surface 5c on the front end side of the fixed piece 5 is formed into a cylindrical surface having substantially the same diameter as the outer peripheral surface 3b of the movable piece 3, and the pipe end is inserted into this portion.

At the rear of the outer peripheral surface 5c of the fixed piece 5, there is formed an annular positioning projection 5d for abutting with the end surface of the pipe end to be fitted and for axial positioning, and further behind it. Has an annular groove 5e.

The fixed piece 5 is fitted in the shaft 2 and is inserted into the cylindrical recess 5b of the fixed piece 5 in the small diameter portion 3c of the movable piece 3.
Is partially inserted, and the annular groove 1 is formed by the end surfaces 3e and 5f of the movable piece 3 and the fixed piece 5 which face each other.
3 is formed, and a molding ring 6 formed of an elastic material in a ring shape is fitted to this portion. Forming ring 6
The material (1) is preferably urethane rubber or the like which is hard because it can be elastically deformed and at the same time has an appropriate hardness. Also,
In this embodiment, the width of the annular groove 13 is adjusted by the screwing position of the female screw 3a of the movable piece 3 and the male screw 2a of the shaft 2 so as to match the width of the molding ring 6. The position of the movable piece after the adjustment is fixed by the lock nut 4.

On the other hand, a plurality of chucks 7 are radially arranged around the molding ring 6. A circumferential forming groove 7a is formed on each inner peripheral surface of the chuck 7 at a position facing the forming ring 6.

An inclined surface 7b is formed on the outer front end of each chuck 7. Further, a groove 7c into which the outer peripheral surface of the elastic body 9 fitted in the annular groove 5e of the fixed piece 5 is fitted is disposed behind the molding groove 7a. The elastic body 9 is made of synthetic rubber or the like in an annular shape, and urges each chuck 7 radially outward, that is, in the expanding direction.

An outer portion of the rear end surface of each chuck 7 is a receiving surface 7d formed in an arc shape, and this portion is supported by a chuck support surface 8a having a concave curved surface formed at the front end of the chuck holder 8. ing. The chuck support surface 8a of the chuck holder 8 is formed in an arc shape that conforms to the receiving surface 7d of the chuck 7, and the chuck 7 is formed with this portion as a fulcrum.
The front end side of the is swingable in the radial direction.

A guide hole 8b for slidably guiding the shaft 2 is formed in the chuck holder 8 so as to penetrate through the central portion thereof, and a male screw 8 is concentrically formed with the guide hole 8b on the outer peripheral surface.
c is formed. The rear end surface 5g of the fixed piece 5 is abutted and supported by the fixed piece support surface 8d between the chuck support surface 8a and the guide hole 8b.

The male screw 8c formed on the outer peripheral surface of the chuck holder 8 is attached to the chuck opening / closing ring 10 from the front thereof.
Is screwed by a female screw 10a formed on the inner peripheral surface of the rear end side. The chuck opening / closing ring 10 is formed in a substantially hollow cylindrical shape, and houses the chuck 7 therein.

The inner peripheral surface of the front end portion of the chuck opening / closing ring 10 is formed into a tapered surface 10b which expands rearward, and this portion is formed on the outer front end portion of each chuck 7 so as to be inclined forward. It is in contact with 7b. 1
Reference numeral 0c is a hole drilled in the radial direction, and a rod-shaped handle (not shown) is inserted into the hole 0c to open the chuck opening / closing ring 1
It is for rotating 0.

When the chuck opening / closing ring 10 is rotated in one direction, the female screw 10a of the chuck opening / closing ring 10 is screwed into the male screw 8c of the chuck holder 8 to move the chuck opening / closing ring 10 rearward, and the taper surface 10b of the chuck 10 opens / closes each chuck 7. The chucks 7 are closed in order to push the inclined surface 7b inward in the radial direction against the biasing force of the elastic body 9.

When the chuck opening / closing ring 10 is rotated in the opposite direction, the chuck opening / closing ring 10 advances.
In each chuck 7, each inclined surface 7b has a taper surface 10
The constraint of b is released, and the chuck 7 is expanded by the elastic force of the elastic body 9.

A driving means 11 for moving the shaft 2 penetrating rearward through the guide hole 8b of the chuck holder 8 is attached to the rear of the chuck holder 8. In this embodiment, the driving means 11 is integrally connected to the chuck holder 8 and is mounted on the support frame 12.

The driving means 11 is constructed by incorporating a piston 11b mounted on the shaft 2 in a cylinder 11a, and feeding a pressurized fluid such as pressure oil to the front of the piston 11b through a port 11f to drive the shaft 2 Is designed to drive backwards. Rear end 11 of cylinder 11a
A lid 11d is screwed to c, and a small-diameter portion 2b at the rear end of the shaft 2 penetrates through the center thereof and is slidably supported.

The lid 11d has recesses 11e formed at a plurality of positions on its front end surface. Elastic body 11g in the recess 11e
When the pressure oil is returned from the port 11f, the elastic force of the elastic body 11g acts on the rear surface of the piston 11b to move the shaft 2 forward and return to the original state. Elastic body 11g
A block-shaped synthetic rubber, a compression spring, or the like is used for this.

Although not shown, the forward position of the shaft 2 is limited to a predetermined amount by a restriction member such as a stopper. Also, around the shaft 2 and the piston 11b,
A seal member 8e for sealing a pressurized fluid such as pressure oil,
11h is provided.

Next, a method of using the pipe end bulging portion forming apparatus of the present invention having the above-described structure will be described. Figure 2
The state where the chuck opening / closing ring 10 is advanced and each chuck 7 is opened is shown.

In this state, the shaft 2 is in the forward position, the movable piece 3 and the fixed piece 5 are separated from each other, and the annular groove 13 formed between them is adjusted to a width T substantially equal to the width of the molding ring 6. Since both end surfaces of the molding ring 6 are not pressed, the molding ring 6 is kept in a state of being immersed in the annular groove 13.

In this state, the pipe end 14 to be molded from the front is fitted over the movable piece 3 and the fixed piece 5. Pipe end 14
The end surface 14a can be brought into contact with the positioning projection 5d to determine the insertion position. In this case, the chuck 7 and the chuck opening / closing ring 10 are provided with through holes 7e and 10e, respectively, so that the contact state between the positioning projection 5d and the end surface 14a of the tube end 14 can be confirmed from the outside.

By using the positioning projection 5d and the through holes 7e and 10e, the position where the bulging portion of the tube end 14 is formed can be accurately determined, but either one of them may be provided, or Both are omitted, for example, the tube end 14
It may be positioned by other methods such as marking near the end of the chuck and aligning with the tip of the chuck 7.

When the chuck opening / closing ring 10 is rotated and retracted toward the chuck holder 8 with the tube end 14 inserted in the apparatus, the taper surface 10b formed on the inner circumference of the front end of the chuck opening / closing ring 10 is moved to each chuck. Inclined surface 7b of 7
In order to push, the chucks 7 rotate in the closing direction to the state shown in FIG. 3 and clamp the outer peripheral surface of the tube end 14.

Next, when pressure oil is introduced from the port 11f to the front surface side of the piston 11b in the cylinder 11a shown in FIG. 1 to drive the piston 11b backward, the shaft 2 moves backward as shown in FIG. As they approach the fixed piece 5 and the width of the annular groove 13 is reduced to T '.
Both ends are pressed and elastically deformed and bulge outward in the radial direction.

As a result, the molding ring 6 presses the inner surface of the tube end 14 and pushes and deforms it toward the molding groove 7a of the chuck 7 to form a bulge 14b along the shape of the molding groove 7a at the tube end 14. To be done. After the bulging portion 14b is formed,
By releasing the pressure oil from the port 11f and advancing the piston 11b to separate the movable piece 3 from the fixed piece 5, the molding ring 6 is retracted into the groove 13 by the elastic restoring force and returns to the state of FIG. The tube end 14 on which the bulging portion 14b is formed can be pulled out forward by rotating the chuck opening / closing ring 10 in the forward direction to expand each chuck 7.

In this embodiment, a cylinder device is used as the drive means 11, but the drive means 11 is not limited to this, and any drive means capable of moving the shaft 2 in the axial direction can be used, for example, to rotate an electric motor. Other well-known drive means such as a screw mechanism or the like for converting into axial movement can be substituted.

Further, as the elastic body 9 for urging the chuck 7 in the expanding direction, an annular body made of synthetic rubber or the like is used in order to simplify the structure in the above embodiment, but it is not limited to this. Alternatively, a well-known elastic urging means such as a compression spring may be used for each chuck 7 to urge it in the expanding direction.

[0041]

According to the pipe end bulging portion forming apparatus of the present invention, the chuck can be opened and closed simply by rotating the chuck opening / closing ring, and the pipe can be attached and detached while the chuck is opened. Since the tube end is securely held by closing the chuck, the tube can be reliably and easily attached to and detached from the device. Therefore, it takes no time to attach and detach the pipe to and from the apparatus, and the efficiency of the piping work can be improved.

Further, since the bulging portion formed at the tube end is separated from the forming groove of the chuck by the movement of the chuck radially outward, an excessive force is applied to the bulging portion at the time of separation. Is prevented from being added. Therefore, the formed bulging portion is not deformed or damaged when it is removed from the device, and the accuracy of assembling the connecting portion of the pipe can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a tube end bulging portion forming device according to the present invention.

FIG. 2 is a partial cross-sectional view showing a chuck open state in an embodiment of the tube end bulging portion forming apparatus according to the present invention.

FIG. 3 is a partial cross-sectional view showing a pipe end portion mounted state in an embodiment of the pipe end bulging portion forming apparatus according to the present invention.

FIG. 4 is a partial cross-sectional view showing a state at the time of molding the bulging portion in the embodiment of the tube end bulging portion forming apparatus according to the present invention.

FIG. 5 is a cross-sectional view showing a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe end bulging portion forming device 2 Shaft 3 Movable piece 4 Lock nut 5 Fixed piece 6 Forming ring 7 Chuck 7a Forming groove 8 Chuck holder 9 Elastic body 10 Chuck opening / closing ring 11 Driving means 12 Support frame 13 Annular groove 14 Pipe end 14b Bulge

Claims (6)

[Claims] 1. A movable piece having a cylindrical outer peripheral surface and fixed to a front end portion of a shaft, and a front end surface opposed to a rear end surface of the movable piece having a cylindrical outer peripheral surface having substantially the same diameter as that of the movable piece. A fixed piece that is inserted into the shaft by means of a shaft, an elastically deformable molding ring that is fitted in an annular groove formed between the end surfaces of the movable piece and the fixed piece that face each other, and a plurality of molding rings around the molding ring. A chuck in which a circumferential forming groove is formed on each of the inner surfaces of the respective arranged and opposed to the forming rings, and an inclined surface inclined forward is formed on each outer front end, and the front end side of each chuck is radially arranged. A chuck support surface for supporting the respective rear end portions and a fixed piece support surface for supporting the fixed piece are formed on the front surface so that the shaft can be expanded and contracted, and a guide hole through which the shaft is slidably inserted is formed at the center. Formed , A chuck holder having a male screw formed on the outer peripheral surface having a concentric contour with the guide hole, an elastic body that constantly urges the front end side of each chuck in a direction to open it, and a chuck that surrounds the outside of each chuck. A substantially hollow cylindrical chuck opening / closing ring in which a female screw to be screwed into the male screw of the holder is formed on the inner surface of the rear portion, and a tapered surface that abuts each inclined surface of the chuck and expands backward is formed on the inner peripheral surface of the front end portion And a drive means for moving the shaft in the axial direction with respect to the chuck holder to move the movable piece toward and away from the fixed piece. 2. The pipe end bulging portion forming device according to claim 1, wherein the molding ring is made of hard urethane rubber. 3. An elastic body for urging the front end side of each of the chucks in a direction in which the chuck is always opened is disposed in an annular groove formed behind an annular groove for accommodating the molding ring on the outer peripheral surface of the fixed piece. 2. A rubber ring whose outer peripheral surface is in contact with each chuck and urges it outward in the radial direction.
Device for forming a bulged end of a pipe. 4. The pipe end bulging portion forming device according to claim 1, wherein the movable piece is screwed to the front end portion of the shaft so as to be axially positionally adjustable, and is fixed by a lock nut. 5. A pipe end expansion according to claim 1, further comprising a positioning projection provided on the outer peripheral surface of the fixed piece at the rear of the annular groove for accommodating the molding ring so as to contact the pipe end surface for positioning. Projection forming device. 6. The chuck and the chuck opening / closing ring are provided with a through hole for externally confirming the contact state of the pipe end surface with the positioning projection provided on the outer peripheral surface of the fixed piece. The pipe end bulging portion forming device according to claim 5.