DE1168739B - Reversing device for work machines, especially machine tools, e.g. B. Planing machines with reciprocating table movement - Google Patents

Description

Reversing device for work machines, in particular machine tools, z. B. Planing machines with reciprocating table movement The invention relates on a reversing device for work machines, in particular machine tools, z. B. Lifting machines with reciprocating table movement and during operation according to a scale adjustable stroke length while maintaining a constant overflow path at different table speeds.

On machines with a reciprocating main movement of the table is it is known to adapt the size of the stroke to the respective conditions. So results z. B. with planing machines the required stroke of the table from the existing one Cutting length and the front and rear overflow path. For setting the stroke adjustable lugs are attached to the long side of the table, which have a Trigger control switch the reversing pulse to change the direction of rotation of the motor trigger for the table drive or by actuating a double-sided friction clutch, mostly designed as a multi-disc clutch, the clockwise or counterclockwise rotation of the engine is mechanical steer.

Reversals of this type, however, have significant shortcomings. So are for setting the lugs to the required stroke length considerable non-productive times required because the machine is stopped to adjust and lock the lugs must become. In addition, there are lugs that go back and forth with the table represents a source of accident risk for the worker working on the machine.

Particular difficulties also arise on planing machines, where the surface to be machined is deeper than the surface of the workpiece and the cutting length is limited by the end faces. An exact setting of the Hubes is difficult here. The degree of difficulty is increased by this increases that the overflow of the workpiece at the individual table speeds is different in size.

To the overflow of the workpiece and thus the stroke of the table independently from the table speed always on an assumed or given economic To keep size, it is known to trigger the triggering of the switching pulses for to relocate the reversing of the table, that is, the lugs on the long side to adjust the table. However, the required adjustment path is only cumbersome afterwards Try to determine.

Furthermore, to control devices on machine tools are known in which cams are arranged on a control disk, which may be on adjustable roller switches act and thus the reversal of movement of the machine part and trigger the associated additional circuits, with an adjustment the switching time is enabled. The disadvantage here, however, is that an adjustment the cam on the control disc or an exchange of the same also only with shutdown machine can take place. The risk of accidents is eliminated, but here too there are high non-productive times for setting or adjusting the stroke.

When using infinitely variable electric motors as drive for the table it is possible to use the control lever for the speed control of the electric motor to be connected to a potentiometer in such a way that the overflow path corresponds to the table speed of the table can be changed with electrical switchgear.

There are also electronic controls to eliminate the shift of the turning point has been used, that is, that the table is independent of the speed always reversed at the same set location, with the setting of the turning points can be done using push buttons from the switching point.

Such reversing devices are, however, relatively expensive and much more susceptible to failure than reversing devices with mechanical machine elements.

The invention is based on the problem of the deficiencies outlined to eliminate and to create a reversal of the type mentioned, which is easier with Service. and as far as possible operational safety the setting of the real Stroke lengths, taking into account the table speed resulting overflow during the table movement by means of mechanical Machine elements enables and can be used on machines of all table sizes.

The invention therefore relates to a reversing device for work machines, in particular machine tools, e.g. B. planing machines, with reciprocating table movement and stroke length adjustable according to a scale during operation while maintaining the same a constant overflow path at different table speeds to which a reversing device is assigned to each direction of movement and each reversing device one that can be driven in alternating directions of rotation according to the table speed Switching drum or dgi. having, via cam rings with roller control switches interacts, through which the reversing of the table, the actuation of the auxiliary drives, if necessary, this is done by emergency switches.

According to the invention sit firmly in a known manner with the on the circumference arranged cam rings provided switching drums freely rotatable on the over the Table movement driven shafts of two pinions, which the sun gears from known webs forming lockable, swivel arms having planetary gears form, which over the arranged on the swivel arms, forming intermediate wheels The gears of the planetary gears drive the shift drums and change the Table stroke takes place by swiveling the swivel arms according to the scale and when changing the table speed, the roller control holders for reversing the advance in reverse and the roller control switch for changing the direction of movement from return to advance in a manner known per se along the circumference of the cam rings are adjustable.

Here, in the further training, the swivel arms can be used as with an external toothing provided disks be formed with by handwheels Comb driven and fixed pinions.

Adjusting the roll reversing switch and the emergency switch can furthermore offset by two against each other on one pivotable by a hand lever Shaft arranged eccentrics, which attack swivel levers with eccentric rods, which carry the roll reversing switch or emergency switch, with the eccentric supporting shaft designed as a hollow shaft and on a shaft supporting the handwheels is stored.

In the drawing, the invention is shown using an exemplary embodiment. It shows A b b. 1 the transmission diagram of the reversing device, A b b. 2 the device for adjusting the stroke length, A b b. 3 shows a section along line A -A of A b b. 1 for return, A b b. 4 shows a section along line BB of A b b. 3 at maximum stroke setting of the switching drum for return, A b b. 5 shows a section along line BB of A b b. 3 with minimum stroke setting of the switching drum for return, A b b. 6 shows the required switching times for the reversing and emergency contacts at low (K), medium (M) and high (G) table speed v T and constant stroke length of the table, A b b. 7 the device for adjusting the reversing and emergency contacts depending on the table speed v T for return, A b b. 8 a section along line CC of A b b. 1 shown for flow, A b b. 9 a section along line DD of A b b. 8 with maximum stroke setting of the switching drum, shown for forward travel, A b b. 10 a section along line DD of A b b. 8 with the minimum stroke setting of the switching drum, shown for advance, A b b. 11 the device for adjusting the reversing and emergency contacts as a function of the table speed v7, shown for the advance.

A shaft 2 or 2 'is mounted in a housing 1 which can be fastened to the machine bed, on which a gear 3 or 3' is rigidly fastened and a pinion 4 or 4 'acting as a sun gear is fastened. On the shafts 2, 2 'there is also rotatably mounted a disk 6 or 6' provided with an external toothing 5 or 5 '. These disks simultaneously each form the webs for lockable swivel arms which mesh with the pinions 4, 4 ' . Planet gears 7, 7 ' are also in engagement with the internal gears 8, 8' of the freely rotatable indexing drums 9, 9 'mounted on the shafts 2, 2 ', on whose outer surfaces cam rings 10, 11, 12, 13 or 10 ', 11 ', 12', 13 'are attached. External teeth 5, 5 'are each connected to handwheels 15, 15' via pinions 14, 14 ' . A HiAR roller switch for the auxiliary drives, releasing the support clamping, chisel ventilation, which interacts with the cam ring 10 , is attached to the housing 1. On a bearing plate 25 that guides the shaft 2 and is fastened to the housing 1, roller reversing switches UR 1 and UR 2 are pivotably mounted via pivot levers 26 and an emergency switch NR via pivot levers 27. The emergency switch NR interacts with the cam ring 13 and the roller reversing switches UR 1 and UR 2 interact with the cam ring 12 or with the cam ring 11. The pivot levers 26, 27 (A b b. 7), the roller reversing switch UR 1 and UR 2 and the emergency switch NR are via eccentric rods 28 and 29 with an eccentric shaft pivoted on the shaft 16 of the handwheel 15 and its two eccentrics 30 offset from one another Link. A hand lever 31 is articulated on the eccentric shaft, which is designed as a hollow shaft. The cable drum 17 on the disk 6 is connected in a known manner to a pointer 19 via a closed traction mechanism drive 18 (A b b. 2) shown in dashed lines. Since the table has to be reversed after the end of the advance or return, i.e. twice, a reversing device must be available for each direction of movement, which initiates the advance or return. Accordingly, two devices of this type are arranged side by side in the housing 1, which are shown in A b b. 3 for return and A b b. 8 are shown for advance.

For a better understanding, the reference numerals of the devices are for the advance (A b b. 8) with a comma, the names of the roller switches for the return with an R and those for the forward with a V.

The gears 3, 3 'attached to the shafts 2, 2' mesh with a gear 32 (A b b. 1) which is connected to the mechanical drive of the table via a gear train 33, 34, etc. The cable drum 17 'on the disk 6' of the device for the advance is also connected to a pointer 21 via a closed traction mechanism drive 20 (A b b. 2) shown in dash-dotted lines. Pointers 19 and 21 mark a scale 22 which is arranged in the housing 1 and which corresponds to a length scale attached to the reciprocating table.

The reversing device works as follows: By means of the handwheels 15, 15 ', the disks 6, 6' provided with external teeth 5, 5 'and the cable drums 17, 17' are rotated via the pinions 14, 14 'and via the closed traction drives 18, 20 the pointer 19, 21 set to the required cutting length. The same can be read on the scale 22 of the housing 1. The movement of the disks 6, 6 'is simultaneously transmitted via the planet gears 7, 7' to the indexing drums 9, 9 'mounted pivotably and rotatably on the shafts 2, 2'. A b b. 4 and 5) for return for the cam rings 10, 11, 12, 13 or for advance 23 ', 24' (from b. 9 and 10) for the cam rings 10 ', 11', 12 ', 13 ' can be set. After switching on the table drive, the movement of the table is transmitted to the gear wheel 32 mounted in the housing 1. Since this meshes with the gears 3, 3 'of the reversing device for the forward and for the return, the shafts 2, 2' and thus the sun gears 4, 4 'of each device are rotated in the same direction. The movement of the sun gears 4, 4 'is transmitted to the indexing drums 9, 9', the planet gears 7, 7 'being held in place according to the set cutting length and now serving as intermediate gears. The rotary movement of the indexing drums 9, 9 'is also carried out by the cam rings 10, 11, 12, 13 or 10', 11 ', 12', 13 'firmly connected to them, while the roller switches of both devices remain in their set position. Shortly before the end of the stroke, the cam of the ring 12 comes under the roller reversing switch UR 1 of the device for the return and actuates it by switching off the drive of the table (from b. 7). Due to the fact that the table continues to run in the outlet, the indexing drums 9, 9 'continue to rotate, and the cam. of the ring 11 now comes under the roller reversing switch UR 2, which switches the table on in the opposite direction. Shortly before the table begins to run in the opposite direction, the roller switch HiAR is actuated by the cam of the ring 10, which triggers the auxiliary drives for releasing the support clamping and chisel lifting. The table now runs back with the tool lifted.

The roll reversal switches of the device for the forward run were not effective during this reversal to reverse. Only after the return has ended, that is, shortly before the set end position is reached, does the cam of the ring 12 'run under the roller reversing switch UV I and switch off the motor. The further sequence of the switching operations is the same as already described for reversing to reverse. The HiAV switch, however, triggers auxiliary drives that switch on the feed, lower the chisel and clamp the support. The roller switches for the reverse switch are now ineffective. This circuit sequence for return and forward is repeated at each reversal point of the table. The distance that the table still covers during the switching time is called overflow and depends on the table speed, the moment of inertia of the table, the weight of the workpieces attached to it and the cutting forces. If the overflow is greater than the set value due to the above-mentioned variable conditions, machine and workpiece damage can result if the reversal is not responded in time. A cam ring 13, 13 'is therefore arranged on each of the switching drums 9, 9', which cooperates with the emergency switch NR or NV in such a way that when the set stroke length is exceeded, the cams of the ring 13 or 13 'release the emergency switch NR or NV actuated, which shuts down the main drive of the machine.

Since the setting of the cam rings 10, 11; 12, 13 or 10 ', 11', 12 ', 13' on the indexing drums 9, 9 'after a certain assumed or given overflow was carried out by the workpiece to be machined and cannot be changed during the work process Table speed the overflow will be greater than the set one. To avoid this, the time at which the switches UR 1, UR 2 and NR or UV 1, UV 2 and, NV are triggered must be changed with the table speed.

In A b b. 6 schematically shows how the factors influencing the length of the overflow can be taken into account by adjusting the switches UV 1, UV 2, NV or UR 1, UR 2, NR at different table speeds in order to achieve a constant stroke length. This is achieved in that the hand levers 31 (Ab b. 7) and 31 ' (Ab b. 11) are pivoted according to a scale into the position required for the correspondingly set table speed. The movement of the hand levers 31, 31 'is transmitted to the eccentric shafts with their eccentrics 30, 30' offset from one another 1, UR 2 and the emergency switch NR as well as UV 1, UV 2 and NV can be pivoted around the shafts 2, 2 '. As a result, the roller reversing and emergency switches on the cam rings are moved depending on the direction of rotation so that sooner or later they come into contact with the cams of these rings. This enables the table to be reversed regardless of the table speed and the inertia forces of the table and workpiece weight according to A b b. 6 always takes place constantly at one and the same desired point. The change in the overflow is thus compensated for by changing the point in time at which the roller reversing switch and emergency switch are actuated. This, like the setting of the respective stroke size (cutting length), can be done in the simplest way while the machine is running by operating the handwheels 15, 15 'and the hand levers 31, 31'.

Claims (3)

Claims: 1. Umsteuereinricfitung for work machines, in particular machine tools, z. B. planing machines, with reciprocating table movement and stroke length adjustable according to a scale while maintaining a constant overflow path at different table speeds, in which each direction of movement is assigned a reversing device and each reversing device od a switching drum drivable according to the table speed in alternating directions of rotation. The like., which interacts via cam rings with roller control switches, by means of which the reversing of the table, the actuation of the auxiliary drives, possibly the emergency switches, are characterized in that the cam rings (10, 11 , 12, 13 or 10 ', 11', 12 ', 13') provided indexing drums (9, 9 ') sit freely rotatable on the shafts (2, 2') of two pinions (4, 4 ') driven by the table movement , which the sun gears of known webs forming lockable swivel arms having n form planetary gears, which drive the indexing drums (9, 9 ') via the gears (7, 7') of the planetary gears that are arranged on the swivel arms and form intermediate gears, and the table stroke is changed by swiveling the swivel arms according to the scale and when changing the table speed the roller control switches (UR 1, UR 2 and NR) for switching from forward to reverse and the roller control switches (UV 1, UV 2 and NV) for changing the direction of movement from return to forward adjustable in a known manner along the circumference of the cam rings are. 2. Device according to claim 1, characterized in that the pivot arms are provided with external teeth Discs (6, 6 ') are formed and with handwheels drivable and fixedly mounted Comb the pinion (14, 14 '). 3. Device according to claim 1, characterized in that the adjustment of the roller reversing switch (UR 1, UR 2 or UV 1, UV 2) and the emergency switch (NR and NV) offset by two on one by a hand lever (31 or 31 ') swiveling shaft arranged eccentrics (30 or 30') which engage with eccentric rods (28, 29 or 28 ', 29') on pivot levers (26, 27 or 26 ', 27'), which the roller reversing switch or emergency switch, the shaft carrying the eccentrics being designed as a hollow shaft and being mounted on a shaft (16 or 16 ') carrying the handwheels (15 or 15'). Documents considered: German Patent No. 842 608; Swiss Patent No. 291340; British Patent No. 561818; U.S. Patent No. 1462,354.