EP0209876A2

EP0209876A2 - Universal bending machine and respective method for bending

Info

Publication number: EP0209876A2
Application number: EP86109981A
Authority: EP
Inventors: Giuliano Ballico; Gerald Hütter; Giorgio Tosolini
Original assignee: BLM SpA
Current assignee: BLM SpA
Priority date: 1985-07-22
Filing date: 1986-07-21
Publication date: 1987-01-28
Also published as: EP0209876A3; IT1201974B; IT8583383A0; JPS6257718A; JPH0757379B2

Abstract

An automatic multiplane bending machine for tube or wire stock from feeding reel (A), comprising in working line: stock strightening means (B), stock drawing or advancing means (C), stock bending means (D), stock cutting means (E) and electronic controlling means to control advancing and bending said stock material (t) to realize multiplane bents (S), wherein said bending means (D) are mounted and rotating sround the stock to be bent or to vary the position of the bending plane.

With this system is avoided the drawback to cut the stock material before bending when bending in different planes is retired.

Description

This invention has as object a method and a machine for the production of three dimensional shapeds.
This innovation finds a particular and convenient application for the production of shaped metallic elongated parts, preferably, but not necessarily, tubular for the bending orientation in three dimensional directions, that is to say with bends not necessarily placed on the same plane, but made also in other planes.
Prior art, particularly in the field of bending and shaping machines, includes automatic bending machines acting in a single plane and also machines that are capable of bending in a sucession of different planes, by a sucession of bends, either in a clockwise or counterclockwise direction. The bending in different planes are particulary necessary in the field of small diameter bended pipes (for example metal tubes of copper or aluminium or other metals) to be utilized in the most varied areas, including that of the automobile vehicles.
These bending machines, from now on called three dimensional bending machines, use the system of starting from a straight tubular piece and consist of machines more or less mechanized, nnd or automated and or electronically programmable, having means for advancing the tubular piece or billet, means for rotating the tube to take it to a predetermined bending plane, means for bending in a fixed plane, preferably with a clockwise or counterclockwise direction, means to cut the tube to length. Machines of this kind are known as tube bending machines or "pipe benders", and are made and marketed by several companies specialized in this field, . such as models "CNC PIPE BENDERS" made by CHIODA KOGYO CO. LTD. company with home office at 4 17, TAGAWA 2 chome YODOGAWA KU, OSAKA - JAPAN, on models B32 and BB63 CNC manufactured by BLM Curvatubi with home office at Via Selvaregina 30 22063 CANTU' (CO) Italy, which use a programmable system and a computerized numeric control command and consist therefore of:

- means to program and store to memory;
- means to view the programs in use;
- means to select the programs in "storage" that are already stored in memory;

These machines therefore need a pipe cutting machine that cuts the tubes in a predetermined length and are not capable of producing three dimensional parts from a feeding reel or coil, but only from a bar, because for the production of three dimensional parts it is necessary to rotate the tube to vary the plane of the bend.
The rotation of the tube to change the plane of the bend is achieved in said machines with numeric control by a program in the same way as for the other parameters of advancement, the entity of the bend and the sucession of the phases.
In the field of bending iron reinforcement bars, there have been developed, and are commonly known, machines called stirrup machines which bend by a program more or less computerized, in a continuous way with feeding from a feeding reel, the wire to be bent, producing brackets or stirrups that every time have to be cut from the feeding wire. With this type of machine however it is possible to make bends in a clockwise or counterclockwise direction, but only in one single bending plane.
The purpose of this invention is to produce a machine capable to automatically work not only on a tube in a form of a straight bar as the former machines, but also with feeding from a feeding reel or coil as the latter kind of machines, and at the same time make it possible to be able to make bends in several bending planes, i.e. to be able to produce a three , dimensional part as the former machines and not only in a single bending plane as the latter machines.
The present invention, as stated in the specification and the claims, solves the problem by the realization of a machine having a bending group attached to and rotating around the tube to be bent, to change the position. of the bending plane.
In the preferred embodiment the machine consists of:

- means to feed the tube or wire from feeding reel or coil;
- means to straighten with rollers the stock material coming from the feeding reel or coil;
- means to advance the stock material coming from the feeding reel or coil along a straight working path;
- means to bend the stock material coming from the feeding reel or coil, which consist of a stock material guiding and control device and a device with a bending nib that rotate around the device that guides and controls the stock material coming from the feeding reel, that engages and bends around said control device the stock material to be bent which is coming from the feeding reel;
- means to cut the shaped piece;
- means to cammand, to program and to control the operation consisting of:
- means with electric impulses that measure the entity of the advancement of the stock material:
- means with electric impulses that measure the entity of the angle of rotation of said device with the bending nib;
- means to program, to add and to compare, capable to calculate the entity of the material that as been advanced and the entity of the bends made, and compare them with the values previously programmed, according to a programmed succession, and eventually perform the cutting.
- where:
- said bending means are mounted in such a way that can rotate around the axis of advancement of the stock material coming from the feeding reel and the respoctive rotation is controllable and is programmable to establish in a logical succession the orientation of the bending plane after the respective advancement.

The advantages that can be obtained due to this solution, essentially consist in that the machine can work from a feeding reel continually; making possible the production of bended parts even three dimensional ones, with an increase in productivity of more than 50% in comparison to the traditional machines that use billets, in addition to a sensible simplification of the construction of the machine itself.
The invention is explained in more details with the enclosed drawings showing one preferred embodiment, of which the particulars of execution are not to be intended as limitative.

Fig. 1 shows a perspective view of an automatic three dimensional tube bending machine according to this invention.
Fig. 2 shows a diagram view of the parts that compose this machine.
Fig. 3 shows a fluid dynamic diagram of the movement command system for the cutting group.

As shown in the above mentioned figures, the invention consists of a machine comprising:

- means to feed the tube or wire (t) from the feeding reel (A);
- means to straighten with rollers (B) the stock' material coming from the feeding reel (A);
- means to draw and to advance the stock material (C) coming from the feeding reel (A) along a straight working path (r);
- means to bend the advanced tube stock material (D) comprising an anvil guide device (1) a bending device with a bending nib (2) which rotates around the anvil guide device, to bend the advanced tube stock material around said anvil guide device (1);
- means to cut the bent part (E);
- means to command, to program and control the operation comprising;
- means with electric impulses that measure the entity of advancement of the advanced stock material (encoder 3);
- means with electric impulses that measure the entity of the angle of rotation of said bending device with the bending nib (4);
- means to program, to add and to compare, capable to calculate the entity of the stock material that has been advanced and the entity of the bends made and compare them with the values that have been previously programmed, according to a programmed succession and eventually perform the cutting (F)
- where:
- said means to bend (D) are mounted in such a way that can rotate Bcound the axis of advancement of the advanced tube stock material coming from the feeding reel (r) and the respective rotation can be controlled and programmed to establish a logical succession as to the orientation of the bending plane after a respective advancement.
- for convenience the rotation of the bending group (D) can be obtained with the use of a motor (5) that has as transmission a chain (5') with means to measure the actual rotation and also of impulse senders that send impulses to the operation program and control command system of the "CNC" (F) machine which also controls:
- by means of an electro valve (17) the means of advancement and return of the fluid dynamic cylinder (6) of the cutting group , in the instant case consisting of a cutting disk driven by an independent electric motor (7);
- the c.c. motor (8) of the drawing and advancement group (c) for the stock material;
- the step motor for the bending angle (4)
- the bending nib (2) consists of an enclosure roller rotating freely and mounted on an arm co-axial to the fixed roller (1) of a diameter corresponding to the radius of the bend cF the tube and therefore interchangeable.

After the rotation of the entire group (D) has completed, the bending roller is pressed against the tube to be bent (t) by means of a fluid dynamic piston (2') that is operated by an electro valve (2") which is controlled by the central system program and control command "CNC" (F).
The working system consists, after having advanced the tube (t) to the desired entity with the motor (8), in rotating the bending group (D) with the motor (₅) to the desired bending plane, around the axis of the path of the tube (r) bringing the bending nib (2) always on the side where it is desired to start the bend with the pulling piston (2') idle, after which, the bending roller is pressed against the tube on the fixed roller and the bending motor (4) is activated, which with the chain (4') rotates the nib (2) in the desired angle of the bend, and then recalls it to the position as at the start, untightening the grip on the tube, determining the acvancement of the tube of another entity, rotate t.he bending group (D) to the second bending plane and proceed with the cycle up to the end and then command the cutting disk of the cutting device (E) allowing the complete bent part (S) to fall, repeating the cycle to produce another bent part and so on in a continuous automatic succession until the desired number of bent parts is reached.
In a practical solution, the cutting group has an approaching sliding command that is controlled by the fluid dynamic cylinder with a mixture of oil and air with a respective oil chamber on the stem (6') and air in a counter position (6") respectively controlled by an electro valve and a hydraulic brake (9) acting at the end of the strokes (Fcl, Fco) and at starting of the slow down (Fc2); from a one way valve (10) and from a flow regulator (11); the whole is operated by an auxiliary cylinder (15) with double chamber, oil (15') and air (15") which is controlled by an electro valve of the drawer type (17) with pressured air feeding (12) and discharge (₁3). In this way, it is possible to obtain a rapid approach and removal with a controlled slow cutting stroke.
Of course, the particulars of the execution may vary without altering the protection of this invention as defined and stated in the claims.

Claims

1. An automatic multiplane bending machine for tube or wire stock from feeding reel (A), comprising in working line: stock strightening means (B), stock drawing or advancing means (C), stock bending means (D), stock cutting means (E) and electronic controlling means to control advancing and . bending said stock material (t) to realize multiplane bents (S), characterised in that it said bending means (D) are mounted and rotating around the stock to be bent (r) to vary the position of the bending plane.

2. A bending machine, according to Claim 1 comprising:

- means to feed the stock (t) from a feeding reel (A);

- means to straighten with the aid of rollers the stock coming from the feeding reel (B);

- means to draw and to advance the stock (C) coming from the feeding reel along a straight working path (r);

- means to bend the stock coming from the feeding reel (D) comprising advanced stock anvil guide means (1), bending means with a bending nib (2) that rotates around the anvil guide means (1), to engage and to bend the advanced stock material around said guide anvil guide means (1);

- means to cut the bent stock (E);

- means to command, to program and control the operation comprising;

- means with electric impulses that measure the entity of advancement of the advanced stock material (encoder 3);

- means with electric impulses that measure the entity of the angle of rotation of said bending device with the bending nib (4);

- means to program, to add and to compare, capable to calculate the entity of the stock material that has been advanced and the entity of the bends made and compare them with the values that have been previously programmed, according to a programmed succession and eventually perform the cutting (F) wherein

- said means to bend (D) are mounted in such a way that can rotate around the axis of advancement of the advanced tube stock material coming from the feeding reel (r) and the respective rotation can be controlled and programmed to establish a logical succession as to the orientation of the bending plane after a respective advancement.

3. A bending machine as claimed in Claim 1, characterised in that the bending group (D) is actuated by a motor (5), comprising means to measure the actual rotation and impulse sender means to imput the program command and operation control means of the machine "CNC" _(F).

4. A bending machine as claimed in claim 1, characterised in that it ; comprises a program command and operation control means "CNC" (F) that controls, by an electro valve (17), the means of motion of advance and return of a fluid dynamic cylinder (6) that moves to approach or return from the bent stock (s) downstream of the bending device (1,2), the cutting group (7) which consists of a cutting disk driven by an independent electric motor in cooperation with the program command and operation control means controlling, a step motor (8) of the drawing and advance means (C), and a step motor for the bending angle (4).

5. A bending machine as claimed in claim 1, characterised in that said cutting means (E) has a sliding command for a rapid approach controlled by a fluid dynamic mixture of oil and air respectively wit chambers for oil on the stem (6') and air in a counter position (6") controlled respectively by an electro hydraulic brake valve (9) acting a; the end of the strokes (Fcl,Fco) and at the beginning of the slow down (Fc2); by a one way valve (10) and by a flow regulator (11): the ensemble being activated by an auxiliary cylinder (15) with double chambers for oil (15') and air (15"), which is controlled by an electro valve (17) with pressured air feed (12) and discharge (13).

6. A bending machine as claimed in claim 1, in which in the bending means, a bending nib (2) comprises a roller that rotates freely, mounted on an arm co-axial to an guide anvil roller in said guide anvil means (1), being the last one of a diameter corresponding to the radius of the curvature of the tube and therefore interchangeable.

7. A bending machine as claimed in claim 1, characterised in that it comprisises means to command and to program a bending roller (2) in said bending means (D) in such a way that the bending roller is pressed against the tube to be bent (t), after having rotated the entire bending group (D), being provided means of a fluid dynamic cylinder (2') actuated by an- electro valve (2") which is controlled by the program command and operation control means "CNC" (F).

8. A bending machine as claimed in claim 1, characterised in that it comprises programming means in order to realize the following operative steps:

- after having advanced the stock (t) in the desired entity by the drawing device (C) assisted by a straightening device (B);

- rotating the bending means (D) around the axis of the path of the advanced stock (r) to the desired plane of the bend placing the bending nib (2) in an idle mode, always on the side where it is desired to start the bend; after that the bending nib (2) is pusced against the opposed anvil guide (1), clench the advanced tube between them to ben it by actuation the motor (4) and chain transmission means (4'); that allow

- rotation the bending nib (2) in the desired angle of the bend around the anvil guide (1), and then recalling it to the starting position, releasing the grip on the bent stock;

- advancing the bent stock to a new position;

- rotating the bending means (D) to a second bending plane and proceeding with the cycle until completed;

- and then cutting off the stock with the cutting disk advancing the cutting means (E), and letting the finished bent stock fall (S); and repeating the cycle to obtain another bent piece in an automatic continuous succession until the desired number of pieces is reached.