EP1543892B1 - Machine for bending bars, in particular tubes - Google Patents

Description

The invention relates to a bending machine according to the preamble of claim 1.

There are bending machines for bending strands, in particular of tubular strands with relatively small outer diameters of about 15 mm and smaller known. These bending machines work without bending mandrels and are equipped with one or more bending stands. The bending head is attached to a vertically arranged by 360 ° pivotable support disk and has a radial slot for insertion of the strand to be bent. This pivotable arrangement of the bending head allows bending in all directions.

From DE-GM 295 01 141 U1 a device for bending pipes is known, which has a bending stand with a rotatably mounted, drivable support disk. The support disk is provided with a segment-like radial slot for inserting unbent pipes. On the support disc, a bending head with a drivable Biegearm is attached. A stationarily arranged on the bending stand motor drives via chains both the support plate and the bending arm on the bending head. For selectively switching the drive movement of the support disk on the bending head and vice versa, a lock, which cooperates with a brake, necessary. This common drive for the pivoting movement of the support disk and for the movement of the bending arm requires a plurality of deflections of the drive movement with pinions and flexible traction means such as chains and corresponding means for braking and locking the support disk movement. Furthermore, this common drive prevents a rapid consequence of the necessary for a bending operation Tragscheiben- and Biegearmbewegung, because between these two movements a blocking of the support plate is required. Only after completion of the blocking movement of the bending arm can be initiated. Therefore, such bending machines work accordingly slowly and because of the many deflections of the long flexible traction means little precise. In addition, she needs a lot of maintenance.

From DE-PS 36 35 169, which forms the preamble of claim 1, a bending machine for bending tubular strands is known, which has a machine bed as a foundation plate for a strand holding device and a displaceable on the machine bed bending stand. The bending stand is provided with a rotatable by 360 ° support plate and attached to the support disc bending head. One first electric motor for the displacement of the bending stand is arranged on the machine bed. This electric motor generates the strand feed by the displacement of the bending stand. A second electric motor is arranged on the sliding bending stand and generates the rotational movement of the support disk by 360 ° together with the bending head. A third electric motor is connected to the bending head and is pivoted together with the support disk and the bending head. The electric motor with a reduction gear and the bending head and the rotatable support disc together form a correspondingly large mass, which must be accelerated and decelerated at each bending operation and at each strand feed. Furthermore, for the power supply to the mobile motors arranged cables etc. for a mobile power supply necessary. By mounting the second electric motor on the bending stand whose displaceable mass is increased. The relatively large masses to be moved limit the working speed and increase the susceptibility of the bending machine. The free space in the range of movement of the workpiece is thereby severely limited.

From DE-PS 38 11 891, another device for bending strand material is known. On a horizontally movable stand, a bending head is attached to a 360 ° rotatable vertical support disc. Parallel to the support disk on the stator, a drive disk is arranged, which pivots a bending arm of a bending head via an angular gear and thereby performs a bending on the strand material. The drive for both the support disc and for the bending head by two mounted on the movable stator motors with their associated gearboxes. When bending strands with multiple bending operations on the same strand, especially on long strands that require a travel of 0.3m or more between bending operations, in this bending device, the horizontally movable stand must move with its bending head together with the two drive motors and their reduction gears become. Between subsequent bending operations on the same strand of the movable stand must be accelerated and decelerated again, which is correspondingly time-consuming for relatively large masses. Furthermore, trailing cables are required for the mobile motors.

The invention is based on the object to overcome the disadvantages described and in particular to build a bending machine, which allows a great deal of flexibility ie a rapid conversion to other products and has a compact relatively lightweight bending stand. In addition, space should be created in the area of the bending stand, thus for facilities for loading and unloading the bending machine good accessibility is available. A further objective is the achievement of a high number of bending cycles per unit time on the same bending part or bending parts which follow themselves by reducing the masses moved and a high bending precision. In addition, the ease of maintenance of the machine should be improved.

According to the invention, this object is achieved by the features of claim 1.

The bending machine according to the invention offers a high degree of flexibility due to the compact bending stand. a quick conversion to other products. The free space in the area of the bending stand also creates additional freedom for the bent product as well as optimum accessibility for loading and unloading facilities. Furthermore, by reducing the moving masses a high number of cycles of bending operations, even with elongated bent tubes, high bending precision and improved ease of maintenance of the machine can be achieved.

An advantageous Anodnung the drive units is achieved if they are attached outside of predetermined displacement paths of the bending stand at the end of the machine bed.

An inexpensive and precise drive can be achieved if the drive units are designed as electric motors that transmit their driving force via profiled shafts to transmissions such as toothed belts, chains, etc. on the carrier disc and on the bending head.

An advantageous arrangement of the force-transmitting machine elements results when the profile shafts are mounted on the machine bed. Further advantages result from the common displacement of the gears with the bending stand and the transmission of the drive movements of the profiled shafts on arranged on the bending stand transmissions on the support plate and the bending head.

A reduction of the movement tolerances of the support plate and the bending head are achievable when the sliding on the profile shafts gears with gears arranged on a bending stand transmission are engaged and the transmission transmitted the drive movement to a drive pulley and from there via gears on the support disc.

A compact design of the bending head and minimal movement masses are achievable when an internal gear rim transmits the drive movement via a gear on the bending head and a bevel gear on the drive axle for the bending operation.

Small tolerances in the movements are achievable according to an embodiment, when the drive axle for the bending operation carries a gear which is in engagement with a arranged on the bending arm rack and a support rail leads before the Biegearmverschwenkung by a linear movement to the strand. Furthermore, a cam can be arranged on the drive axle for the bending operation, which is in contact with a linearly movable scanner and which transmits the linear movement to a slide rail.

The pivoting movement of the bending arm is automatically initiated when the support rail has reached a support position on the tubular strand.

In order to obtain dimensionally accurate bent workpieces, the movement tolerances that are decisive in the bending operation are of crucial importance. It is therefore advantageous to optimize all gearwheels involved in the motion transmission with reduction ratios, from the drive motor to the bending head. It is therefore proposed to achieve by the choice of the reduction of the engine speed at the gears before and after the transmission least possible movement tolerances.

In the following, the invention will be explained in more detail by way of example.

Fig. 1

eine Seitenansicht einer Einkopfbiegemaschine,

Fig. 2

eine zweite Seitenansicht auf die Biegemaschine gemäss Fig.1,

Fig. 3

eine Draufsicht auf Fig.1,

Fig. 4

einen Schnitt durch den Biegekopf nach der Linie IV-IV in Fig. 6,

Fig. 5

einen Schnitt gemäss der Linie V-V in Fig. 2,

Fig. 6

einen vom Biegeständer getrennten Biegekopf in Perspektive und

Fig. 7

einen Biegekopf ohne Biegewerkzeug und ohne Zahnstangenabdeckung.

Showing:

Fig. 1

a side view of a single-head bending machine,

Fig. 2

a second side view of the bending machine according to Fig.1,

Fig. 3

a plan view of Figure 1,

Fig. 4

a section through the bending head along the line IV-IV in Fig. 6,

Fig. 5

a section along the line VV in Fig. 2,

Fig. 6

a bending head separated from the bending stand in perspective and

Fig. 7

a bending head without bending tool and without rack cover.

In Fig.1-3 and 5, 1 denotes a machine bed for an inventive bending machine. On the machine bed 1, a strand holding device 2 are arranged in a stationary manner and a bending stand 4 (not shown) which is displaceable in the direction of the central axis 3 of the unbent strand. The example shown in Fig. 1-3 shows a single-head bending machine. By arranging a second machine bed and a second bending stand on the right side of the strand holding device 2, the single-head bending machine could be extended to a double-head bending machine.

At the bending stand 4, as known from the prior art, a support disc 5 for a bending head 6 is arranged. The support plate 5 is rotatably mounted about the central axis 3 of the unbent strand by 360 ° and provided with a radial slot 13 for insertion of the strand. Outside a predetermined displacement path 8 of the bending stand 4 drive units 9, 10 and 11 are arranged stationarily at the end of the machine bed 1. The drives, designed in the example shown as electric motors, the following drive functions are assigned. The drive 9 can move the bending stand 4 along the machine bed 1 in the direction of the arrow 14 via a ball screw spindle 12. The drives 10 and 11 transmit their drive motion to profile shafts 15 and 16, e.g. Shafts with a keyway, which are mounted on the machine bed 1. The rotational movement of the profile shafts 15 and 16 is transmitted to gears 17 and 18 which are mounted on the profile shafts 15 and 16 and displaceable together with the bending stand 4. Transmission, e.g. Timing belts 20 and 21 transmit the drive movements to the support disk 5 or, as shown in FIG. 2, indirectly via an additional drive disk 19 and gears 22, 23 onto the support disk 5 or onto the bending head 6.

In Fig. 4, the bending head 6 is shown without bending stand 4 (Fig. 1,2 + 5). The bending head 6 receives its drive movement for the bending operation of the drive pulley 19 via a ring gear 28 to a gear 35. The gear 35 is keyed on an axis 24, which feeds the drive via bevel gears 25 of the drive shaft 26 for the bending operation. At the end of the drive shaft 26, a bending tool 37 is clamped. In addition, the drive shaft 26 carries a cam 31 which is in contact with a scanner 38 and transmits a linear movement to a slide rail 33 (Fig. 5 + 6). On the drive shaft 26, a gear 32 is also arranged, which is in engagement with a rack 39. The rack 39 transmits a in Fig. 5 + 6 support rail 29 shown a linear movement.

6, the bending head 6 is provided with a pivotable about the drive axis 26 bending arm 27 and the linearly movable in the direction of arrow 30 support rail 29 and the linear movement in the direction of arrow 34 slide rail 33. The bending tool 37 is placed on the drive axle 26.

In Fig. 7, the effect of the gear 32 and the rack 39 for the linear movement of the support rail 29 is easily recognizable. The gear 32 transmits at the beginning of the bending operation, the rotational movement on the rack 39 which carries the support rail 29. The support rail 29 is driven against a workpiece, not shown, and clamps this in the bending tool 37 (Fig 4,5,6) firmly. Via the scanner 38, the slide rail 33 receives a linear movement from the cam 31 to the bending tool 37 (FIGS. 4, 5, 6). After the clamping of the workpiece by the support rail 29, the pivoting movement of the bending arm 27 is automatically initiated by the movement standstill of the support rail 29.

After a change of direction of the bevel gear 25 of the bending arm 27 is pivoted back and then the support rail 29 retracted. The workpiece is now without clamping on the bending tool 37 and the bending stand 4 can be moved to a new position and another bending operation can be made on the workpiece. In the same way, the necessary number of bends on a workpiece can be carried out rapidly in a program-controlled manner before it can be removed from the strand holding device 2 automatically or by hand and a new workpiece can be inserted.

Claims (10)

1. Bending machine for bending rods, in particular tubular rods, said machine consisting of a rod-holding device (2) and of a bending stand (4) which can be displaced on a machine bed (1) in the direction of the central axis (3) of the unbent rod, wherein said bending stand is provided with a carrying disc (5) for a bending head (6), which carrying disc is mounted so as to be rotatable about said central axis (3) by 360°, and said carrying disc (5) has a radial slit (13); and said machine also consisting of driving units for the displacement of the bending stand (4), for the rotation of the carrying disc (5) and for the bending operation by means of the bending head (6), characterised in that the driving units (9-11) for the displacement of the bending stand (4), for the rotation of the carrying disc (5) and for the bending operation are disposed on the machine bed (1) in a stationary manner, and that profiled shafts (15, 16) for transmitting the driving movement from the stationary driving units (10, 11) to the bending stand (4) are provided along a path (8) of displacement of the bending stand (4) on the machine bed (1).
2. Bending machine according to Claim 1, characterised in that the driving units (9-11) are fastened to one end of the machine bed (1) outside-a predetermined path (8) of displacement of the bending stand (4).
3. Bending machine according to Claim 1 or 2, characterised in that the driving units (10, 11) are constructed as electric motors which transmit their driving force via the profiled shafts (15, 16) to gearwheels (17, 18) and transmissions such as toothed belts (20, 21), chains, etc., to the carrying disc (5) and to the bending head (6).
4. Bending machine according to Claim 3, characterised in that the profiled shafts (15, 16) are mounted on the machine bed and the gearwheels (17, 18) are disposed so as to be displaceable, together with the bending stand (4), along said profiled shafts (15, 16).
5. Bending machine according to Claim 3 or 4, characterised in that the gearwheels (17, 18) which slide on the profiled shafts (15, 16) are in engagement with gearwheels belonging to a transmission (20, 21) disposed on the bending stand and, via said transmission, the driving movement can be transmitted to a driving pulley (19) and, from the latter, via gearwheels (22, 23) to the carrying disc (5) and the bending head (6).
6. Bending machine according to one of Claims 1 to 5, characterised in that a gear ring (28) transmits the driving movement to a gearwheel (35) engaging in said gear ring (28) and, via a bevel gear unit (25), to a driving spindle (26) for the bending operation.
7. Bending machine according to Claim 6, characterised in that the driving spindle (26) carries a gearwheel (32) which is in engagement with a toothed rack (39) disposed on the bending arm (27) and guides a supporting rail (29) towards the rod by means of a linear movement prior to the tilting of the bending arm.
8. Bending machine according to Claim 6, characterised in that the driving spindle (26) has a cam disc (31) which is in contact with a detector (38) which is movable in a linear manner and which transmits a linear movement to a sliding rail (33).
9. Bending machine according to one of Claims 7 or 8, characterised in that a tilting movement of the bending arm (27) can be initiated automatically when the supporting position of the supporting rail (29) on the rod is reached.
10. Bending machine according to one of Claims 3 to 9, characterised in that the tolerances of motion which are determinative in the bending process can be optimised by choosing the gearing-down of the rotational speed of the motor by the gearwheels (17, 18) and of the transmission (20, 21) and also from the latter to the driving pulley (19).

Images