JP2007167925A - Mandrel-movable type swaging machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mandrel-movable type swaging machine constituted so that the mandrel is not broken in the case of forming the inner surface of a work while adjusting to the outer peripheral surface shape of the mandrel by hitting the outer peripheral surface of the work with the plurality of dies. <P>SOLUTION: This swaging machine is provided with a mandrel driving mechanism 25 which controls so that a mandrel holding shaft 26 for holding the mandrel 24 is synchronously rotated with the rotation of the work A and also can be retreated in synchronization with the advancing shift of the work A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a swaging machine configured such that a mandrel used for swaging the inner surface side of a shaft hole of a pipe-shaped workpiece can move in the axial direction.

  Swaging is often used as a processing means for reducing the outer diameter of a round bar. The same applies to round pipes as well as round bars, but swaging is performed in the axial direction while the workpiece is struck by a die from the outside, where the workpiece is sequentially processed to have a predetermined outer diameter. If the workpiece is a round pipe, it is processed so that a mandrel fits into the hole and does not collapse.

  By the way, although there are various workpieces to be subjected to the swaging process, the outer peripheral cross section is basically circular, and the material varies from a relatively soft one to a hard one. The present invention is an apparatus for forming the inner surface of a pipe by swaging, but in a conventional swaging machine, a die that strikes the outer peripheral surface of a workpiece is mounted at a predetermined position, and the workpiece is axially following the movement of the die. It is configured to move forward. The mandrel to be inserted into the work is supported in a fixed state at a fixed position.

  FIG. 5 is a schematic diagram for swaging the inner surface (d) of a pipe-shaped workpiece (a). A mandrel (b) is inserted into the workpiece (a), and a plurality of dies (c), (c),. The outer circumference of the workpiece (I) is pressed. In other words, the dies (c), (c) are arranged on the outer periphery of the work (b) and moved inward toward the center to hit the outer periphery of the work (b), and as a result, the inner surface (d ) Is crushed and formed into the shape of the outer peripheral surface of the mandrel (b).

  The dice (c), (c), and so on, move intermittently to the left of the axis when leaving the work (a) to intermittently apply pressure. The work (a) is processed at a constant pitch along with the movement, but the mandrel (b) does not move. Therefore, as the work (a) moves, the work inner surface (d) rubs against the mandrel (b) to generate friction, and a large load acts on the mandrel (b) in the axial direction.

  Although the base of the mandrel (b) is gripped, it cannot withstand the axial load acting on the tip (e) and the mandrel (b) buckles. In particular, when the workpiece (a) is thin or the inner diameter of the swallowed workpiece (a) is small, the outer diameter of the mandrel (b) is inevitably reduced, which further promotes the buckling phenomenon. To do.

  Therefore, the mandrel (b) is damaged due to buckling, and even if it is not damaged, the mandrel (b) is bent, thereby hindering the feeding of the workpiece (a) and lowering the machining accuracy of the inner surface of the workpiece. On the other hand, the outer peripheral surface of the mandrel (b) is worn by being constantly rubbed when the workpiece (b) is fed. Of course, surface treatment or a hard material is used to suppress wear, but the wear of the surface cannot be completely prevented, and the wear of the mandrel surface affects the processing accuracy. If a hard material is used to suppress wear, it becomes brittle and promotes damage due to buckling, and it is not easy to prevent both buckling and wear.

There are various well-known documents on swaging devices. However, the “plastic processing device” disclosed in Japanese Patent Application Laid-Open No. 11-741 is a high-quality product with less wear on processing tools, defects such as cracks in processed products, and variations in product characteristics. This is a swaging device that can stably mass-produce processed products. However, there is no document regarding the prevention of breakage and wear prevention due to buckling of the mandrel (b).
"Plastic processing apparatus" according to JP-A-11-741

  As described above, when the inner surface of the pipe-shaped workpiece is subjected to the swaging process, there are problems as described above. The problems to be solved by the present invention are these problems, and provide a mandrel movable swaging machine in which the mandrel is not damaged or worn by friction based on rubbing when the workpiece is fed in the axial direction.

  The basic structure as a swaging device is the same as the conventional one. In other words, the spindle head is rotatably held on the inner peripheral side of the annular outer ring via a plurality of swaging rollers, and a guide groove provided in the spindle head has a hammer. A die is disposed inside (center side) of the hammer, and the hammer moves together with the spindle head to move against the swaging roller and simultaneously presses the die toward the center side. Accordingly, a workpiece sandwiched between a plurality of dies is struck by the dies and processed into a predetermined shape.

  The workpiece has a chuck for holding the workpiece so as to be positioned on the central axis, and the chuck is movable in the axial direction. A mandrel extends from the opposite direction to the chuck that holds and fixes the base of the workpiece, and the mandrel is inserted into the shaft hole of the workpiece. In the present invention, the mandrel gripping part that holds the base part of the mandrel is provided with a mandrel drive mechanism that can move backward following the workpiece feed. That is, the mandrel gripping part moves without stopping at a fixed position.

  On the other hand, a mandrel extends from the same direction as the chuck for holding and fixing the base of the workpiece, and the mandrel is inserted into the shaft hole of the workpiece. In the present invention, the mandrel gripping part that holds the base part of the mandrel is provided with a mandrel drive mechanism that can move forward following the workpiece feed. That is, the position of the mandrel with respect to the chuck is not limited.

  In the swaging machine according to the present invention, the mandrel gripping part that fixes the base part of the mandrel can move backward or forward following the feed of the workpiece. Therefore, there is no rubbing between the mandrel outer peripheral surface and the work inner surface when the workpiece is fed, and there is no axial load generated by friction based on the conventional rubbing, and therefore, no mandrel buckling phenomenon occurs. And since there is no rubbing, the outer surface of the mandrel is not worn. This not only prolongs the life of the mandrel, but also leads to an improvement in workpiece swaging accuracy.

  FIG. 1 and FIG. 2 are embodiments showing a mandrel movable swaging machine according to the present invention, and show a front view and a side view. In the figure, 1 represents a die, 2 represents a hammer, 3 represents a spindle head, 4 represents a swaging roller, 5 represents a hammer roller, and 6 represents an outer ring. The swaging rollers 4, 4,... Are arranged at equal intervals on the inner peripheral surface 7 of the annular outer ring 6, and the spindle head 3 is held inside the swaging rollers 4, 4,.

  The spindle head 3 can be rotated via the swaging rollers 4, 4... And the hammers 2, 2... Fit into the grooves provided in the spindle head 3, and the inside of the hammer 2 (center side). Dice 1,1, ... are arranged. The hammer rollers 5, 5... Are rotatably mounted on the outside of the hammers 2, 2.

  Therefore, if the spindle head 3 rotates, the hammer rollers 5, 5,... Intermittently hit the swaging rollers 4, 4,. The dies 1, 1,... Connected to 2, 2,. The inside of the dies 1, 1... Forms an arcuate surface 9, 9... Continuous with the tapered surface 10, 10..., And the arcuate surface 9, 9. Work A is machined thinly. The four dies 1, 1,... Are operated simultaneously as a set so as to press the workpiece A.

  Although the gaps 11, 11,... Remain between the dies 1, 1,..., The spring force that pulls the adjacent dies 1, 1,. Energized. Therefore, if the hammer rollers 5, 5... Are separated from the swaging rollers 4, 4,..., The dies 1, 1,. Returned in the direction. Of course, if the spindle head 3 rotates at a high speed, the dies 1, 1... And the hammers 2, 2... Receive the centrifugal force and move outward, and the swaging rollers 4, 4. 5. Moves inward when hit.

  Incidentally, a flywheel 14 is attached to the main shaft 13, and the main shaft 13 rotates together with a pulley 15 assembled to the flywheel 14. The pulley 15 is interlocked with the motor via a belt, and the spindle head 3 connected to the main shaft 13 rotates together with the main shaft 13. The main shaft 13 is a pipe and has a slider rod 16 inside.

  A slider 17 is attached to the tip of the slider rod 1, and a wedge 18 extends from the slider 17 to the die side. There are four wedges 18, 18,... Inserted between the dies 1, 1,. Therefore, if the wedges 18, 18,... Are pushed by the slider rod 16 and move to the die side, the dies 1, 1,. Therefore, the thickness of the wire subjected to the swaging process can be controlled by inserting and removing the wedges 18, 18,.

  By the way, the slider rod 16 is configured to rotate with the dies 1, 1..., The hammers 2, 2, and the spindle head 3 and slide in the axial direction while rotating. If the gear 19 is rotated by a servo motor (not shown), the screw 20 connected to the gear 19 is rotated, and the ball screw 21 screwed with the screw 20 is guided so as not to rotate. In addition, it can slide in the main axis direction.

  The ball screw 21 slidable in the main axis direction is connected to a connecting bearing 22, and the slider rod 16 and the connecting bearing 22 are connected via a thrust bearing 23. Accordingly, the slider rod 16 can slide with the ball screw 21 while rotating with the spindle head 3. The rotation of the gear 19 is controlled by a servomotor, and the workpiece A can be machined into a predetermined shape by controlling the cross-sectional reduction rate of the workpiece A while performing swaging.

  The slider rod 16 and the ball screw 21 are hollow pipes, and a mandrel gripping shaft 26 is inserted into the internal space. The mandrel gripping shaft 26 extends long, and grips and fixes the mandrel 24 at its tip. The mandrel 24 is inserted into the hole of the pipe-shaped workpiece A, and the workpiece A is crushed by being pressed from the outside with the dies 1, 1,..., And the inner surface of the workpiece is formed into a shape that fits the outer periphery of the mandrel 24. Is done.

  The workpiece A is fed in the axial direction (left direction) by a certain length while rotating, and is processed by the feed length. In the present invention, a mandrel drive mechanism 25 is provided so that the mandrel 24 is inserted into the hole of the pipe-shaped workpiece in advance by a predetermined length, and the mandrel 24 moves backward as the workpiece A is moved. The mandrel drive mechanism 25 shown in FIG. 1 employs a hydraulic drive mechanism and is configured to be driven by a hydraulic cylinder 28.

  FIG. 3 is an embodiment showing the mandrel driving mechanism 25, and the mandrel gripping shaft 26 extends through the shaft hole of the piston 27 of the mandrel mechanism 25. The piston 27 is accommodated in a hydraulic cylinder 28, and a tip part of the piston 27 protrudes from the hydraulic cylinder 28, and a head 29 is attached to the tip. In the head 29, bearings 30a and 30b are provided to rotatably support the tip of the mandrel gripping shaft 26.

  A head 29 is attached to the tip of the piston 27 indicated by hatching, and the tip of the mandrel gripping shaft 26 is screwed to and connected to the head 29. Therefore, the mandrel gripping shaft 26 can move in the axial direction following the movement of the piston 27 and is supported by the bearings 30a and 30b, so that the mandrel gripping shaft 26 is allowed to rotate. Has been.

  The hydraulic cylinder 28 has two oil supply ports 31a and 31b, and if hydraulic oil is supplied from one oil supply port 31a, the piston 27 moves to the left, and conversely operates from the other oil supply port 31b. If oil is supplied, the piston 27 can move to the right. FIG. 3 shows the case where the piston 27 has moved to the left end, and the mandrel 24 fixed to the chuck portion 32 at the right end of the mandrel gripping shaft 26 is also in the retracted position.

  The workpiece A is gripped by the power chuck 33 and can move in the axial direction in synchronism with the movement of the dies 1, 1. The operating oil is supplied to the oil supply port 31a so that the mandrel 24 inserted into the shaft hole of the workpiece A can be moved backward following the forward movement of the workpiece A. The supply of the hydraulic oil is controlled to synchronize with the forward movement of the workpiece A.

  Incidentally, the mandrel driving mechanism 25 shown in FIG. 3 is a hydraulic mechanism including a hydraulic cylinder, but the movement of the mandrel gripping shaft 26 can be controlled by an NC motor. That is, the NC motor can be used to control the mandrel gripping shaft 26 to move backward in synchronization with the forward movement of the workpiece A.

  FIG. 4 shows another embodiment according to the present invention, in which the mandrel 24 extends from the side of the power chuck 33 that clamps the workpiece A. The basic structure is the same as in FIG. 1, and the rod 34 is a hollow pipe, and a mandrel gripping shaft 26 is inserted into the internal space. The mandrel gripping shaft 26 extends long, and grips and fixes the mandrel 24 at its tip. The mandrel 24 is inserted into the hole of the pipe-shaped workpiece A, and the workpiece A is crushed by being pressed from the outside with the dies 1, 1,..., And the inner surface of the workpiece is formed into a shape that fits the outer periphery of the mandrel 24. Is done.

  The workpiece A is fed in the axial direction (left direction) by a certain length while rotating, and is processed by the feed length. In the present invention, a mandrel driving mechanism 25 is provided so that the mandrel 24 is inserted into the hole of the pipe-shaped workpiece in advance by a predetermined length, and the mandrel 24 is moved forward as the workpiece A is moved. Here, the chuck claw 35 clamping the workpiece A is operated by a chuck claw opening / closing hydraulic cylinder 36, and the chuck claw 35 is rotationally driven by a chuck rotation gear 37. Same as swaging machine.

The front view of the swaging apparatus which concerns on this invention. The side view of the swaging apparatus which concerns on this invention. The example which shows a mandrel drive mechanism. Another mandrel drive mechanism attached to the swaging apparatus according to the present invention. Swaging process with a mandrel inserted into the shaft hole of a pipe-shaped workpiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dice 2 Hammer 3 Spindle head 4 Swaging roller 5 Hammer roller 6 Outer ring 7 Inner peripheral surface 8 Outer 9 Arc surface
10 Tapered surface
11 Clearance
12 Coil spring
13 Spindle
14 Flywheel
15 pulley
16 Slider rod
17 Slider
18 Wedge
19 Gear
20 screws
21 Ball screw
22 Connecting bearing
23 Thrust bearing
24 Mandrel
25 Mandrel drive mechanism
26 Mandrel gripping shaft
27 Piston
28 Hydraulic cylinder
29 head
30 bearings
31 Refueling port
32 Chuck part
33 Power chuck
34 Rod
35 Chuck claw
36 Hydraulic cylinder for opening and closing the chuck jaws
37 Chuck rotating gear

Claims (4)

The spindle head that rotates with the rotation of the main shaft is held by a swaging roller arranged on the inner peripheral surface of the outer ring, and a plurality of hammers mounted on the spindle head with hammer rollers that contact the swaging roller are attached to the spindle head. The center axis has a mandrel that fits into the hole of a pipe-type workpiece, and the workpiece outer surface is struck with the above-mentioned multiple dies so that the workpiece inner surface conforms to the mandrel outer shape. In the swaging device to be molded, a mandrel driving mechanism for controlling the mandrel gripping shaft for gripping the mandrel so as to be rotated in synchronization with the rotation of the workpiece and to be retracted in synchronization with the forward movement of the workpiece is provided. Characteristic mandrel movable swaging machine. The spindle head that rotates with the rotation of the main shaft is held by a swaging roller arranged on the inner peripheral surface of the outer ring, and a plurality of hammers mounted on the spindle head with hammer rollers that contact the swaging roller are attached to the spindle head. The center axis has a mandrel that fits into the hole of a pipe-type workpiece, and the workpiece outer surface is struck with the above-mentioned multiple dies so that the workpiece inner surface conforms to the mandrel outer shape. In the swaging device to be molded, a mandrel driving mechanism for controlling the mandrel gripping shaft for gripping the mandrel to be rotated in synchronization with the rotation of the workpiece and to be advanced in synchronization with the forward movement of the workpiece is provided. Characteristic mandrel movable swaging machine. As the mandrel drive mechanism, a mandrel gripping shaft for gripping the mandrel is inserted into the shaft hole of the slide rod, and the end of the mandrel gripping shaft is connected to the tip of a piston that slides with a hydraulic cylinder and a bearing that allows rotation is provided. The mandrel movable swaging machine according to claim 1 or claim 2. The mandrel movable swaging machine according to claim 3, wherein the hydraulic cylinder is provided with two oil supply ports to control the hydraulic oil supplied so as to synchronize with the forward movement of the workpiece.

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