GB2177035A

GB2177035A - Pipe bending machine

Info

Publication number: GB2177035A
Application number: GB08516365A
Authority: GB
Inventors: Alan Laycock
Original assignee: INTEGRATED PRODUCTION MACHINES
Current assignee: INTEGRATED PRODUCTION MACHINES
Priority date: 1985-06-28
Filing date: 1985-06-28
Publication date: 1987-01-14
Also published as: EP0227778A1; GB8516365D0; WO1987000097A1

Abstract

A pipe bending machine serves to bend two pipes simultaneously and is particularly suited to produce "handed" pairs of pipes. Holding means (26) support the pipes parallel to each other and advance them simultaneously into a bending head. This head comprises a bending die (12) and a clamp (16) for clamping the two pipes against its surface. The bending die is turned on its axis to perform the bending. The holding means (26) turns the two pipes through equal but opposite angles to select the plane of the next bend to be performed.

Description

SPECIFICATION Pipe bending machine This invention relates to a pipe ortube bending machine, particularly but not solely to such a machine of the draw bending type.

Hitherto pipe ortube bending machines have been arranged to handle a single pipe ortube at a time. We have now devised a bending machine which is arranged to handle two pipes ortubes simultaneously.

In accordance with this invention, there is provided a pipe bending machine having means for holding two pipes simultaneously and means for performing a like bending operation on the two pipes simultaneously.

In a preferred embodimentofthis invention, the machine isa draw bending machineandthetwo pipes are held and advanced parallel to each other into the bending head. This bending head includes a bending die and a clamp for clamping the two pipes to that bending die: turning of the bending die serves to bend the two pipes whereafterthe clamp is released to enable the bending die to be returned to its original position and the pipes to be advanced ready forthe next bend to be made.The pipes are arranged to be automatically rotated abouttheiraxes if that next bend is to be in a different plane from the previous bend, but they are rotated in opposite senses: thus this preferred embodiment of bending machine is particularly suited to forming "handed" pairs of pipes and the machine will operate with relatively little limitation or risk due to interference between the portionsofthetwo pipeswhichatanytimearedown- stream ofthe bending head.

The preferred embodiment ofthis invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic plan view of the example of pipe bending machine; and Figure2 is a section on the line Il-Il of Figure 1, on an enlarged scale.

Referring to the drawings, there is shown a pipe or tube bending machine of the draw bending type. At a forward end ofthe machine bed, a bending head 10 is provided. This comprises a bending die 12 of generally cylindrical form and mounted for rotation about its axis, which is disposed vertically. The bending die is formed with two annular grooves 14spaced apart from each other and being semi-circular in section.

The bending die 12 is provided with a short, flatfaced, tangential extension 1 2a which has two grooves forming tangential extensions ofthe grooves 14. A clamp block 16 is provided to cooperate with the extension 1 2a and is formed with two semi-circular section grooves horizontally across its face, so that it can clamp two pipes 1, 2 againstthe bending die 12. The clamp block 16 is mounted to an arm 18forsliding movementtowardsandawayfrom the bending die extension 12a: the arm 18 is mounted for rotating about the axis of the bending die so that it can be turned with the bending die during a bending operation.

The bending head further comprises a pressure die 20, having a flat surface formed with two semicircular section grooves co-operating with the grooves ofthe bending die. The pressure die 20 is movable towards and away from the bending die, and is also movable lengthwise of the pipes during a bending operation. Awiper die 22 may also be provided, fixed to the machine bed, and positioned opposite the pressure die and shaped at its forward end to fit close against the bending die. The flat rear surface ofthe wiper die is also provided with two semicircular section grooves co-operating with the grooves of the pressure die.

The bending machine further comprises two pipe ortube holders mounted one abovethe other on a carriage 24: one only of these holders is shown at 26.

The carriage 24 is mountedforsliding movement along the length of the machine bed. Each pipe holder comprises a cylindrical bodythrough which, in use, the pipe extends, and is provided with a colletwhich can be applied to gripthe pipe.Thetwo pipe holder bodies are rotatable about their axes and coupled so that they will rotate through equal angles but in opposite directions.

The machine also comprises two mandrels 28 carried at the ends of respective mandrel rods 30. The mandrels are positioned in the pipes to supportthe latter internally immediately upstream of the bend.

The mandrel rods are mounted to the machine beyond the trailing ends of the pipes being processed.

The machine is powered hydraulically and controlled by a computer numerical control system. In use, with two pipes 1,2 placed overthe mandrels and mandrel rods and held in their pipe holders 26, then firstly the carriage 24 is advanced to position the two pipes correctly, relative to the bending head, ready for the first bend to be made. Then the pressure die 20 is advanced to press the pipes against the bending die, and the clamping block 16 is advanced to clamp thetwopipessecurelyagainstthebendingdie. Next the bending die 12 and clamp arm 18 are turned together around the axis ofthe bending die, and through the angle required. During this step, the pressure die 20 slidesforwardly infollowing the pipes.The clamping block is then retracted to free the pipes from the bending die and the clamp arm 18 is returned to its initial position.

The carriage 24 is next advanced an appropriate amount so as to position the pipes correctly forthe next bend. The bending die and pressure die are returned to their initial positions. If the next bend in the pipes is to be effected in a different plane from the first bend,thenthe pipe holders 26 areturned through the appropriate angle (but in opposite directions, as mentioned above). That next bend in the pipes is then carried out in the same manner as explained above, and the whole sequence of steps is repeated for all the following bends which are to be made in the pipes.

In accordance with a preferred feature,the drive meanswhich returnstheclamp arm to its initial position may be arranged to transmit drive to turn the clamp arm in the required direction during the bending operation (drive from a separate drive means being transmitted to the bending die itself). Instead however, drive may be transmitted only to the bending die (during the bending operation), the bending diethen itselfturning the clamp arm.

It will be appreciated that, because when the pipes are rotated between successive bending operations, they are rotated through opposite directions, there are nevertheless cases in which interference will occur between the portions ofthe two pipes which at anytime are downstream ofthe bending head. Preferably however an off-line programming system may be provided for the machine, with its software so arranged that the system will determine and indicate when there would be any interference of the two pipes if processed on the machine according to the program being formulated. Although particularly suited for producing "handed" pairs of pipes,the machine may also be used to produce two individual pipes simultaneously.

Claims

1. Apipebending machine, comprising meansfor holding two pipes simultaneously, means spaced from the holding means and operable to engage the two pipes simultaneously, and driving meansfordisplacing the engaging means to perform a like bending operation on the two pipes simultaneously.

2. A pipe bending machine as claimed in claim 1, which is a draw bending machine, in which the holding means is operable to hold the two pipes parallel to each other, and means are provided for displacing the holding means lengthwise of the pipes to advance the two pipes into said engaging means.

3. A pipe bending machine as claimed in claim 1 or 2, in which said engaging means comprises a bending head which includes a bending die having an axis of rotation and a clamp for clamping thetwo pipes to the bending die and the driving means serves to turn the bending die on its axis to bend the two pipes.

4. A pipe bending machine as claimed in any preceding claim, in which the holding means comprises means for rotating the pipes about their axes to select the plane of bend, said rotating ofthe two pipes being in the opposite senses.

5. A pipe bending machine as claimed in any preceding claim, comprising a computer numerical control system.

6. A pipe bending machine of a draw bending type, comprising a bending head which includes a bending die of generally cylindrical form and a vertically disposed axis of rotation, the bending die having a peripheral surface which is formed with two annular grooves spaced apa rtalong the axis of the bending die and serving to receive two pipes, a clamp displaceable towards and away from the peripheral surface ofthe bending dieforclamping and unclamping the two pipes against the bending die, holding means spaced from the bending head and provided with two holders for gripping the two pipes parallel to each other, means for displacing the holding means to- wards the bending head to advance the two pipes into the bending head, and drive means for turning the bending die about its axis to perform a like bending operation on the two pipes simultaneously.

7. A pipe bending machine as claimed in claim 6, further comprising means for rotating the two pipe holders through equal angles but in opposite senses.

8. A pipe bending machine substantially as herein described with reference to the accompanying drawings.