DE10003449C2 - Hydraulic universal clamping tower in modular design - Google Patents

Description

The invention relates to a clamping tower for a machine tool according to the Preamble of claim 1. This is e.g. B. a CNC Machine, with at least one side mounting wall, on which in at least a workpiece to be machined can be clamped on one plane.

Tension towers of this type are generally known. You will be on the palette one Machine tool attached and are rotatable by means of the pallet, so that the Workpieces fastened to the clamping tower and to be machined for example a drilling, milling or other processing tool are positionable.

It is also known on one of the side mounting walls of the tension tower not just clamping one workpiece to be machined, but several Arrange workpieces one above the other in several levels. Then can with the Machining tool of the machine one after the other in different Workpieces approached at heights of the clamping tower and accordingly to be edited.

After machining all workpieces that are clamped on an assembly wall are, the tension tower is rotated so that the next assembly wall with again several workpieces compared to the machining tool is aligned. After processing all workpieces on all levels each individual mounting wall is either the processing tool too switch to rework the workpieces one after the other, or if the  Machining is complete, the workpieces from the clamping tower are closed remove and then re-populate it.

To increase efficiency, it makes sense to load several pallets with them Keeping tensioning towers ready and loading the machine with a new pallet. The reloading of the tensioning tower can then take place outside the machine and does not stop the further production process.

The number of workpieces that can be machined with an assembly depends on the number of assembly walls, the workpiece size and the maximum vertical Tool strokes (spindle travel), which is the norm for many machines Corresponds to 630 mm.

So it is possible to construct tensioning towers, the four side mounting walls have on which each in z. B. two different levels of workpieces Machining can be clamped. Thus, in one work cycle eight workpieces can be processed. This number is in the known Tension towers essentially due to the given standard size of 630 mm Spindelweg and the large space required for clamping and changing the Given workpieces. It would also be possible to have them pre-assembled accordingly Base plates have to be kept ready, but this makes storage in disadvantageous Way would be charged. (see DE 43 31 166 C2, DE 42 19 967 A1).

It has also been found to be disadvantageous that the known tensioning towers each have to be specially designed for a workpiece to be machined. Should a completely different workpiece be machined after completion of production the entire spanning tower against a new one is again special to replace the adapted tower. This results in high production costs and long set-up times.

A clamping tower for a machine tool is also known from EP 0 298 168 A1 several extending from at least one side mounting wall  Levels, each at least one, mechanically or by means of a fluid have actuatable clamping device for holding a workpiece, known.

The disadvantage of this tension tower is that there is space for one to be clamped Workpiece is limited by the height of the spacer plates and in the event of a change the entire clamping tower for inserting spacer plates with another Height must be dismantled.

The object of the invention is to provide a universally applicable, modular structure To provide a tension tower with which without further or only with little Adjustments with as little space as possible various workpieces can be clamped for processing.

This object is achieved by the invention characterized in claim 1, d. H. in that each clamping device is a central, with the mounting wall Detachably connected connection unit on which a clamping head and a Base plate are releasably attached.

In this construction, the modular structure is such that the Clamping tower as such is always a central one, even after a workpiece change again represents a universally usable column, on which in turn modular constructed clamping devices are attached, with which preferably one each workpiece to be machined can be clamped.

When converting production to a different workpiece, you need if need be, only the tensioning device attached to the tensioning tower was changed become. Since this in turn has a modular structure, it is sufficient to use only certain ones Parts of the clamping device to change and the remaining parts continue to use.

This results in a constant reusability and universality of the entire modular elements of the tension tower structure, i.e. the tension tower  itself and the modular clamping devices, which means set-up times, resulting production costs and material costs can be saved.

Due to the low overall height according to the invention at maximum The clamping path of each clamping device can do more per mounting wall Workpieces are clamped and processed. For example, with a Clamping tower with four assembly walls and four levels up to 16 workpieces in editable in a production cycle.

Advantageous embodiments of the invention result from the Dependent claims.  

To achieve great flexibility, it is advantageous if in one Mounting wall, especially for every level, mechanical and / or hydraulic and / or pneumatic connection points are arranged, to which each Clamping device with suitable connection points can be connected. Through these connection points it is then possible that in each Existing mechanism for clamping a workpiece actuate.

It also proves useful if the connection points of a type so z. B. the hydraulic, can be controlled centrally. So it turns out z. B. the possibility of the tensioning tower provided with the tensioning devices to assemble a large number of workpieces and centrally controlled via a hydraulic line all workpieces simultaneously in all over the connection points clamp interconnected fixtures.

After all workpieces have been machined, they can also be machined at the same time released from their clamping and removed from the tensioning tower become.

In addition to central control of the hydraulics, it is also possible, for. B. all pneumatic or mechanical connection points and thus any further functions of the clamping devices, such as. B. the rotation of the Work piece or a clamping head in the released state, centrally controlled.

A particularly simple and universal design results according to the invention further characterized in that all clamping devices are identical can. For example, clamping devices that are used during the Production damage can be replaced from a low inventory.

To identical fixtures in every level of an assembly wall and also To be able to use on all assembly walls, it is recommended that Junction points in every level of an assembly wall are also identical train.  

The connection points thus form groups, each for connecting one Clamping device are provided and z. B. equidistant from each other are, so that in this case the clamping devices are evenly distributed in the different levels of an assembly wall are arranged.

Another essential aspect of the invention is modularity and low Height of the clamping devices with maximum clamping path, which on one Tension tower and in particular used on the tension tower according to the invention can be.

The modularity of each clamping device, which can be attached to the clamping tower, is essentially achieved in that the tensioning device comprises at least one central connection unit on which a clamping head and a base plate can be attached.

In this case, only the central connection unit with the Clamping tower releasably connected. Each central connection unit has on its side facing the mounting wall at least one positioning pin, which engages in a corresponding recess, one in each level Mounting wall of the tension tower is arranged. This will create a reproducible positioning of the clamping devices and the therein clamped workpieces z. B. achieved with an accuracy of 1/100 mm, so that the workpieces can also be manufactured with this accuracy.

The connection unit can also have at least one additional positioning pin have their underside, each in a suitable recess in the base plate engages in order to ensure that it is also exact and reproducible on the Attach the connection unit.

With this construction z. B. with changed requirements for Clamping device due to a changed workpiece while maintaining the central connection unit only the clamping head, or the base plate or both can be exchanged, thereby reducing costs.  

The central connection unit represents a basic body that all mechanical and / or hydraulic and / or pneumatic connections for includes the connection to a tension tower. This ensures that the in the mechanics provided by means of these connections in the Connection unit can be controlled via the tension tower.

Furthermore, the construction has the advantage that when changing the Workpiece and the associated exchange, for example of Clamping head none of the z. B. hydraulic and / or pneumatic lines must be opened because the corresponding connection points by the on Tension tower remaining central connection unit are closed.

The connecting unit has an actuatable pressure pin, by means of which one Force can be transmitted to a clamping rod arranged in the clamping head if the Clamping head is attached to the connection unit.

Both the base plate and the clamping rod of the clamping head are standing laterally with respect to the connecting unit and opposite each other, so that a workpiece between the head of the clamping rod and the base plate can be arranged and clamped.

The pressure pin has a piston at one end, which in a Piston sleeve, especially in a cylinder bore provided therein, is slidably arranged. This piston sleeve can, for. B. as a separate component be attached to the bottom of the connection unit, making quick maintenance and interchangeability of the pressure pin is guaranteed.

In this construction, the piston sleeve can be designed such that the Piston of the pressure pin can be pressurized on both sides. Particularly advantageous it is when the pressure is applied hydraulically, because it is sufficiently high Clamping pressures of z. B. 160 bar can be realized in the clamping device.  

Due to the bilateral nature of the pressurization can also be achieved be that the tensions are released specifically on request can wait without a pressure drop in the individual clamping devices to have to.

The connecting unit is preferably characterized in that especially in an upper area, an annular groove and a rotatably mounted Has swivel sleeve, which are each arranged coaxially to the pressure pin and by means of which the clamping head can be attached to the connecting unit. The central axis of the pressure pin is one according to the coaxial structure Axis of rotation around which the clamping head, when attached to the connection unit is mounted, is rotatable.

For a rotatable connection between the clamping head and the connection unit To manufacture, the clamping head has an annular collar on its underside on the when the clamping head is attached to the connection unit in its Ring groove engages appropriately. The one when clamping over the clamping head on the In this construction, workpiece forces are exerted via the ring groove added.

Furthermore, the clamping head is assembled with the swivel sleeve Connection unit connected, causing it to move out of its clamping position can be turned out.

The rotation can be in the connection unit and / or in the Mechanism arranged z. B. triggered hydraulically or pneumatically are achieved, which ensures that after releasing the tension between the arranged in the clamping head and the base plate Workpiece can be removed more easily from the clamping device, what the space requirement of the clamping device for arranging and removing of the workpieces reduced.  

The swivel bushing is preferred to ensure precise rotatability stored by means of a needle bearing, the swivel sleeve in another Embodiment of the invention can have a collar-shaped approach that with its underside rests on a sliding surface on the connecting unit.

To ensure a defined position of the clamping head in relation to the Connection unit before an intended clamping of workpieces a spring-loaded ball can be arranged in the collar-shaped neck, the in the desired centering position in a recess in the sliding surface engages and holds the clamping head in position and against an unintentional Secures torsion. The detent between the ball and the recess is designed so that they are initiated by the rotation of the clamping head can be overcome.

To the rotation of the clamping head relative to the connection unit realize, the swivel sleeve has bolt-shaped on its underside Projections on which push rods z. B. a mechanical and / or pneumatic connection point between the clamping tower and the connection unit attack by means of which the swivel sleeve can be rotated.

The push rods, which are connected to the bolt-shaped projections are connected to the piston be located within the tension tower and hydraulic or else be moved pneumatically. So you can also centrally over the spanning tower Controlled all clamping heads are simultaneously rotated around the workpieces refer to.

For clamping a workpiece which is arranged on the base plate was, an already mentioned tension rod is provided in the clamping head is pivotally arranged in a self-aligning bearing. This is preferably done that its central longitudinal axis through the center of the self-aligning bearing and through the center of a spherical end of the pressure pin, whereby easy longitudinal rotation is achievable.  

If the clamping head is mounted on the connection unit, the clamping rod is in place at one end in contact with the pressure pin of the connection unit. The piston is moved by pressurizing the piston and turns the tension rod like a lever around the center of the self-aligning bearing.

In this case, selected distances between the Point of contact from the pressure pin with the tension rod and the self-aligning bearing as well as the entire length of the tension rod desired power ratios can be adjusted, which is facilitated by the fact that the tension rod is preferably interchangeable.

At the end of the tension rod, which is on the Moves the base plate and comes into contact with the workpiece An interchangeable head element. Due to the interchangeability the head element can be easily attached to different surface structures and shapes of a workpiece can be adapted.

It is also considered to be very advantageous that a uniform Force distribution between the workpiece and the head element is achieved that the tie rod through the storage in the self-aligning bearing is rotatable about its longitudinal axis and thus automatically when braced by turning to a z. B. sloping or uneven surface of the Adapts workpiece.

When pressure is applied, the tension rod is through the pressure bolt preferably deflectable against a spring load, so that the tension rod after Pressure relief automatically by the spring load in their original Position is pushed back and preferably on a path-limiting End stop is present.

The path-limiting end stop is particularly intended for the Connection between clamping head and connection unit during assembly is made easier since this defines the rest position of the tension rod and  this is a defined connection of pressure pin and tie rod end allows.

The spring load can be by a through the pressure pin Pressurized spring-loaded end of the tension rod Be pin realized with the rounded end in a V-shaped groove on Housing of the clamping head is arranged.

This has the advantage that the mentioned longitudinal rotation of the Tension rod is made possible, but the tension rod after pressure relief automatically into a defined by the spring bolt guided in the V-groove Starting position for the next clamping process is returned.

Due to the releasable attachment of the base plate and head element to the central one Connection unit ensures that workpieces in a simple manner can be clamped at different heights in the clamping device.

The maximum workpiece height results from the maximum distance between the base plate and the head element of the tension rod in the unloaded Status. The workpiece must, however, at least for secure clamping have a height that the distance between the head element and base plate in corresponds to the maximum deflected state of the tension rod.

If smaller workpieces are to be clamped, it is simply possible to between Insert an intermediate piece or a corresponding piece into the workpiece and base plate to mount the modified base plate on the connection unit. Here, the Surface of the base plate to be provided with wart-like projections only few support points and thus secure clamping of the workpiece to reach the base plate.

If larger workpieces are to be clamped, then between the base plate and Clamping head a longer connection unit can be used.  

Accordingly, in both cases, only modular parts of the Clamping device can be changed without replacing the entire device, thereby reducing part costs.

An embodiment of the invention is shown in the drawings and will described in more detail below. Show it:

Figure 1 is a plan view of a tensioning tower with four side mounting walls and tensioning devices mounted thereon.

Fig. 2 is a side view of a mounting tower according to the invention with clamping devices which are fixed on each mounting wall in four levels;

Fig. 3 is a side view of a clamping device of the invention with a mounted base plate and disassembled clamping head;

Figure 4 is a plan view of a clamping device with clamping head disassembled.

5 is a sectional view of the mechanism for rotating the pivot sleeve.

Fig. 6 is a side view of the tensioner with mounted clamping head without a base plate;

Figure 7 is a section through the fastening plane for mounting the tensioning device the tensioning tower. and

Fig. 8 is an illustration of the individual elements from which the clamping head is composed.

Fig. 1 shows a supervision of a tensioning tower 1 according to the invention, which with its round base 2 on the pallet 3 z. B. is placed on a CNC machine. In the embodiment described here, the tensioning tower 1 has a square cross section and thus has four lateral mounting walls 4 , to which the tensioning devices 5 are fastened in several planes.

The arrangement of the clamping devices 5, identical in the present exemplary embodiment, in a total of four levels on each mounting wall 4 can be seen more clearly in FIG. 2. In each of the clamping devices 5 shown here, a workpiece 6 , shown in broken lines, is clamped between the head element 8 of the clamping rod 7 and the base plate 9 , in total 16 workpieces 6 simultaneously in the present case.

It can also be seen here that the workpiece 6 does not rest on the entire surface of the base plate 9 , but on only a few (here four) wart-like projections 10 which are arranged on the surface of the base plate 9 . This storage in only a few support points ensures that the centered and fixed workpiece 6 can be clamped securely.

In FIG. 2, also provided for in the clamping devices 5 holes 11 are seen through which the tensioning devices 5 may be secured by screws to a side wall assembly 4 of the mounting tower. 1 This is also shown in FIG. 7 in a clearer sectional view through the fastening plane. A quick and easy interchangeability of the entire clamping device 5 is thus ensured.

The tensioning tower 1 and each tensioning device 5 furthermore have hydraulic, pneumatic and mechanical connection points by means of which the tensioning device 5 and tensioning tower 1 can be connected to one another in order to actuate the mechanics of the tensioning devices 5 centrally.

For feeding, in particular the hydraulic and pneumatic connection points with fluid, that is, for. B. hydraulic oil or compressed air, the tensioning tower 1 has a plurality of inlets and / or outlets.

Within the tension tower 1 , the incoming and outgoing fluids are then conducted via lines 33 , 54 , 55 and the corresponding connection points, so that, for. B. the mechanisms of all 16 clamping devices 5 can be actuated simultaneously by a central pressurization.

The modular structure of each clamping device 5 according to the invention is shown in more detail in FIGS. 3 to 7.

Fig. 3 shows the modular composition of an inventive clamping device 5 of a central connection unit 12 to which the base plate 9 is detachably fastened by means of screws 13. In this figure, the clamping head 14 is shown as a further modular unit separate from the connecting unit 12 .

In the exemplary embodiment shown, the connection unit 12 has both hydraulic connection points 15 and 15 'and mechanical connection points 16 and 16 '.

There are also positioning pins 58 and 59 on the side of the connecting unit 12 facing the mounting wall 4 , which engage in corresponding recesses in the tensioning tower 1 and serve for exact positioning of the connecting unit 12 on the mounting wall 4 of the tensioning tower 1 . A reproducible accuracy of 1/100 mm is achieved.

At least one further positioning pin 57 is located on the underside of the connection unit 12 . This engages in a recess 56 in the base plate 9 in order to position it exactly as well.

The piston 18 located at the lower end of the pressure pin 17 can be pressurized via hydraulic oil, which can be supplied to the connection points 15 and 15 'through the tensioning tower 1 via lines 54 , 55 . The piston 18 is slidably arranged in a cylinder bore 19 of a piston sleeve 20 and can be pressurized on both sides by guiding the hydraulic lines 53 between the connection points 15 and 15 'and the cylinder bore 19 , which are located both in the connecting unit 12 and in the piston sleeve 20 in order to be able to move the piston 18 selectively up or down on request.

The piston liner 20 is in turn designed as a separate part and pressure-tightly attached to the connecting unit 12 by screws in order to, for. B. to be removable for maintenance work on the pressure pin 17 . Since the piston sleeve 20 projects with its dimensions beyond the outer dimensions of the connecting unit 12 , the base plate 9 has a corresponding recess which surrounds the piston sleeve 20 when the base plate 9 is fastened to the connecting unit 12 .

The connection unit 12 shown in FIG. 3 has in its upper region an annular and collar-shaped projection 21 , through which an annular groove 22 is formed, which extends coaxially to the central axis 17 'of the pressure bolt 17 . Projection 21 and annular groove 22 are formed around the pressure bolt 17 over an angular range of 360 °.

Also coaxial to the center axis 17 'is arranged a pivot bushing 23 around the pressure pin 17, which is rotatably mounted in the connection unit 12 by a needle bearing 24th The clamping head 14 can be rotatably mounted on the connecting unit 12 both via the annular groove 22 and via the swivel sleeve 23 .

For this purpose, the swivel bushing 23 also has a collar-shaped extension 25 , the underside of which rests on a sliding surface 26 of the collar-shaped projection 21 of the connecting unit 12 . This collar-shaped extension 25 comprises two radial threaded bores 27 for receiving screws 27 ', with which the clamping head 14 is fastened and secured to the connecting unit 12 in the assembled state.

Between the two radial threaded bores 27 , the collar-shaped extension 25 has a cutout 60 in order to receive the rear end 38 of the clamping rod 7 when the clamping head 14 is mounted on the connecting unit 12 .

Furthermore, the annular groove 22 and the collar-shaped extension 25 of the swivel sleeve 23 are partially covered by a cup-shaped protective cap 61 which can be screwed to the collar-shaped extension 25 and thus moves with it when the swivel sleeve 23 rotates.

The protective cap 61 has, with respect to its central axis, which corresponds to the central axis 17 'of the pressure bolt 17 after mounting, a recess 62 which runs radially from the outside inwards, in particular over approximately 130 ° in the form of a segment of a circle, which widens in a circular manner in the central region around the axis , This cutout 62 essentially has the shape of the rear region 48 of the clamping head 14 , which fits in the cutout 62 in the assembled state.

Thus, a protective cover 61 and clamping head 14 form a cover which completely surrounds the annular groove 22 after assembly and which covers the annular groove 22, for. B. protects against chips removed from the workpiece 6 .

To fasten the clamping head 14 to the connecting unit 12 , the underside has an annular collar 28 , which extends over an angular range of approximately 130 ° and engages in the annular groove 22 of the connecting unit 12 when the clamping head 14 is on the connecting unit 12 is put on. Here, the upper rounded end of the pressure pin 17 engages in a suitable recess 39 on the pressurized end 38 of the tension rod 7 located in the clamping head, whereby a connection between the pressure pin 17 and the tension rod 7 is established.

After fastening by means of the screws 27 'in the threaded bores 27 of the swivel sleeve 23 , the clamping head 14 can be rotated in its entirety about the axis 17 ' by means of a controlled rotation of the swivel sleeve 23 from its clamping position into a position for removing and inserting a workpiece 6 , as shown in dashed lines in Fig. 1. The swivel angle α is 60 ° here, but can also be set to other values.

In order to enable this rotation to be controlled centrally by the tensioning tower 1 , bolt-shaped projections 30 are arranged on the underside of the swivel bushing 23 , on which push rods 31 engage. This is shown in section through the corresponding plane in FIG. 5. The push rods 31 in turn are guided out of the tensioning tower 1 through the channel-shaped mechanical connection points 16 and 16 'to the bolt-shaped projections 30 and driven by means of pneumatically operated pistons 32 which are located in corresponding cylinder bores 32 ' in the tensioning tower 1 .

The unit consisting of cylinder bores 32 ', pistons 32 and push rods 31 forms a pneumatically actuated mechanical connection point 16 , 16 ', which is realized in every plane on each mounting side 4 of the tensioning tower 1 . The cylinder bores 32 ′ shown in FIG. 5 are all connected to one another by lines 33 which run through the entire height of the tensioning tower 1 and can be pressurized centrally with compressed air.

The same applies to the hydraulic connection points 15 and 15 ', which are shown in FIG. 6. Here, each lower connection point 15 is connected via an essentially horizontally running channel to a line 55 running vertically over the entire height of the tensioning tower 1 , which line is located in the middle of the tensioning tower 1 in this exemplary embodiment (in relation to the cross section). This line 55 carries the hydraulic oil with which the piston 18 of the pressure pin 17 is displaced for clamping a workpiece 6 .

Via another vertical line 54 , which also has horizontal branches to each connection point 15 'for each level, the hydraulic oil for pushing back the pressure bolt 17 , and thus for releasing the workpiece 6 , is supplied to the piston 18 .

By pressurizing one of the pistons 32 , the latter is displaced forward in the cylinder bore 32 ', as a result of which the push rod 31 presses against the projection 30 and the pivot sleeve 23 rotates together with the clamping head 14 . If the rotation is to be reversed, the corresponding other piston 32 must be displaced by compressed air after a pressure relief.

In order to secure the position of the clamping head 14 with the clamping rod 7 relative to the workpiece 6 to be clamped in before clamping and after a pneumatic pressure drop in the rotating mechanism against unintentional rotation, a spring-loaded ball 34 is arranged in the collar-shaped extension 25 of the swivel sleeve 23 , which in the desired centering position engages in a corresponding recess in the sliding surface 26 .

The spring, which rests with one end on the ball 34 , is supported with the other end on the inside of the protective cap 61 , which is fastened to the swivel sleeve 23 . In order to prevent the protective cap 61 from being moved in an uncontrolled manner by the force of the spring after loosening its screw connection to the swivel sleeve 23 , the protective cap 61 is secured by means of a locking pin 63 , for which purpose this engages under the projection 21 of the connecting unit 12 .

The engagement between ball 34 and recess is designed so that the clamping head 14 is secured against unintentional rotation, but the engagement force is overcome by a pneumatically triggered rotation of the swivel sleeve, so that the clamping rod 7 is then pivoted over the workpiece 6 .

In order to limit the swivel angle α of the clamping head 14 in the event of a triggered rotation, a stop pin 65 is arranged in the sliding surface 26 of the connecting unit 12 , which engages in an elongated arc-shaped recess or groove 66 which on the underside of the collar-shaped extension 25 of the swivel sleeve 23 is provided.

In the clamping position of the clamping head 14 , which is shown in FIG. 4, the stop pin 65 then lies against one end of the groove 66 , the ball 34 simultaneously engaging in the recess provided in the sliding surface 26 .

If the swivel sleeve 23 is rotated by a pneumatic release, the stop pin 65 comes to rest on the other end of the groove 66 and thus limits the swivel angle α of the swivel sleeve 23 to z. B. 60 °.

The tension rod 7 can be pivoted in the tensioning head 14 by means of a self-aligning bearing 29 about an axis of rotation 45 perpendicular to the plane of the sheet and at the same time rotatably supported about its longitudinal axis 46 in the plane of the sheet.

In the assembled state of the clamping head 14 , which is shown in FIG. 6, the pressure bolt 17 is then raised during a hydraulic displacement of the piston 18 and presses the rear end 38 of the clamping rod 7 upwards, as a result of which the pendulum bearing 29 is adjustable and desired lever ratio, the head element 8 of the clamping rod 7 lowers, presses on the workpiece 6 and clamps it.

The head member 8 is attached to the clamping bar 7 interchangeable, so that on the one hand the shape of the head element can be adapted to 8 to the shape of a workpiece 6 and on the other hand the tension rod 7, after removal of the head member taken 8 from the self-aligning bearing 29 and against a tension rod 7 can be exchanged with a different length. This makes it possible in particular to change the leverage ratios and thus the resulting clamping forces.

Due to the rotatability of the tension rod 7 about its longitudinal axis 46 , which is also shown on the right in FIG. 5, it is still ensured that the head element 8 lies evenly against a workpiece 6 , since the head element 8 automatically adapts to the surface by rotation ,

This rotatability is ensured by the fact that both the center point of the self-aligning bearing 29 and the center point of the spherically rounded end of the pressure bolt 17 lie on an axis which corresponds to the central longitudinal axis 46 of the tension rod 7 .

When clamping a workpiece 6 , the clamping rod 7 is deflected by the pressure pin 17 against a spring load. In the present exemplary embodiment, this spring loading is realized by means of a spring-loaded pin 35 which is arranged in the region of the end 38 of the clamping rod 7 arranged in the clamping head 14 .

The pin 35 is provided with a bore in which a compression spring 47 is arranged and is in turn arranged in a bore 49 in the rear pressurized end 38 of the tension rod 7 . The pin 35 is secured against jumping out of this hole with a screw.

If now for releasing the clamping of a workpiece 6, the pressure pin 17 retracted hydraulically, it will automatically by the spring loading of the pin 35, the end of which is supported on the housing of the clamping head 14, the clamping bar 7 is returned to its starting position and the head member 8 is lifted from the workpiece 6 ,

Any rotation of the tension rod 7 and the head element 8 about the longitudinal axis 46 is automatically reversed here, since the rounded end of the pin 35 rests in a V-shaped groove 36 provided on the inner housing wall and the oblique side surfaces 64 of the groove 36 den Push pin 35 and thus also the tension rod 7 back into a centered position.

When pushing back the tension rod 7 by means of the spring-loaded pin 35 , the tension rod 7 is pressed against a path-limiting stop pin 37 in order to define the position of the tension rod 7 in the unloaded state. This is particularly important for the fact that the clamping head 14 can be mounted on the connection unit 12 in a simple manner.

The stop pin 37 ensures that the end 38 of the clamping rod 7 located in the clamping head 14 assumes a desired position relative to the rounded upper end of the pressure bolt 17 . Only in this way the recess 39 can ride up on the end of the tension rod 7 in a defined manner over the bevelled end 38 of the tension rod 7 to the rounded end of the pressure pin 17 and engage over this.

The detailed structure of the clamping head 14 is shown in several sectional views in FIG. 8. This FIG. 8 shows that the clamping head 14 essentially comprises the two head components 40 and 41 . The two head components 40 , 41 are screwed together by means of screws 42 through the bores 43 and the threads 43 '.

The head part 40 thereby comprises the pendulum bearing 29 which is pressed by the clamping head in the inside of the head member 40th Also from the inside of the clamping head 14 , the clamping rod 7 is guided through the self-aligning bearing 29 and then screwed to the head element 8 .

The inner end 38 of the tension rod 7 has, in addition to the beveled surface and the recess 39 , in which the pressure pin 17 engages, grooves 44 on two opposite sides, which overlap two stop pins 37 and form the limit stop with these.

The self-aligning bearing 29 pressed into the head component 40 is secured against being pressed out due to the high pressure load when clamping a workpiece 6 by means of two pins 52 pressed into the head component 41 , which are screwed into the head components 40 and 41 in corresponding recesses 52 'from the inside of the head press against the self-aligning bearing 29 .

The V-shaped groove 36 , which is provided for centering the round end of the spring-loaded pin 35 , is arranged on the inside at the top of the head member 41 and is formed here in that two bolts 50 and 51 are pressed into the top, the inside of which of the head component 41 pointing bolt heads each have a bevel 64 at an angle, here 45 °. This results in a groove 36 with an opening angle of 90 ° between the heads of the bolts 50 , 51 . Other angles are also possible.

The front head component 40 and also the central connecting unit 12 have bevelled surfaces 67 and 68 on the area facing the workpiece 6 , in order to make it easier to remove the workpiece 6 from the clamping device or to put it in easier, since this construction makes it easier with the hands can reach around the workpiece 6 .

In summary, it can be stated that a large number of workpieces 6 can be clamped simultaneously with the clamping device 5 according to the invention when operated on the clamping tower 1 according to the invention, the modularity of the devices proving to be particularly flexible, universal and cost-saving.

LIST OF REFERENCE NUMBERS

1

tombstone

2

foot

3

palette

4

prefabricated walls

5

jig

6

workpiece

7

tension rod

8th

header

9

baseplate

10

wart-like projections

11

drilling

12

connecting unit

13

screw

14

clamping head

15

Connection point (hydraulic)

15

'' Connection point (hydraulic)

16

Connection point (mechanical)

16

'' Connection point (mechanical)

17

pushpin

17

'Center axis

18

Piston (hydraulic)

19

bore

20

piston bush

21

head Start

22

ring groove

23

pivot bushing

24

needle roller bearings

25

collar-shaped approach

26

sliding surface

27

threaded holes

27

'Screws

28

ring-shaped collar

29

aligning bearing

30

projections

31

pushrods

32

Piston (pneumatic)

33

Line (pneumatic)

34

Bullet

35

pen

36

V-shaped groove

37

stop pin

38

End of the tie rod

39

recess

40

head assembly

41

head assembly

42

screw

43

drilling

43

'Thread

44

groove

45

axis of rotation

46

longitudinal axis

47

compression spring

48

the backstage area

49

drilling

50

bolt

51

bolt

52

pencils

52

'Recess

53

hydraulic lines

54

Pipe (hydr.)

55

Pipe (hydr.)

56

recess

57

positioning

58

positioning

59

positioning

60

recess

61

protective cap

62

recess

63

safety pin

64

faces

65

stop pin

66

groove

67

beveled surfaces

68

beveled surfaces
α swivel angle

Claims (18)

1. Clamping tower for a machine tool with a plurality of planes extending from a lateral mounting wall, each having at least one, mechanically or by means of a fluid actuated clamping device for holding a workpiece, characterized in that each clamping device ( 5 ) has a central, with the mounting wall ( 4 ) detachably connected connection unit ( 12 ) on which a clamping head ( 14 ) and a base plate ( 9 ) are detachably attached. 2. Clamping device according to claim 1, characterized in that the central connecting unit ( 12 ) comprises all mechanical and / or hydraulic and / or pneumatic connections ( 15 , 15 ', 16 , 16 ') for the connection to a clamping tower ( 1 ). 3. Clamping device according to claim 1 or 2, characterized in that the connecting unit ( 12 ) has an actuatable pressure pin ( 17 ), by means of which a force on a clamping rod ( 7 ) arranged in the clamping head ( 14 ) can be transmitted. 4. Clamping device according to claim 3, characterized in that the pressure pin ( 17 ) has at one end a piston ( 18 ) which is arranged displaceably in a piston sleeve ( 20 ) which can be fastened to the connecting unit ( 12 ). 5. Clamping device according to claim 3 or 4, characterized in that the piston ( 18 ) of the pressure pin ( 17 ) in the piston sleeve ( 20 ) can be pressurized on both sides, in particular hydraulically. 6. Clamping device according to one of the preceding claims, characterized in that the connecting unit ( 12 ) has an annular groove ( 22 ) and a rotatably mounted swivel sleeve ( 23 ) which are arranged coaxially to the pressure pin ( 17 ) and by means of which the clamping head ( 14 ) can be fastened to the connecting unit ( 12 ). 7. Clamping device according to claim 6, characterized in that the swivel sleeve ( 23 ) has a collar-shaped projection ( 25 ) which rests with its underside on a sliding surface ( 26 ) on the connecting unit ( 12 ). 8. Clamping device according to claim 7, characterized in that in the collar-shaped extension ( 25 ) a spring-loaded ball ( 34 ) is arranged, which engages in a centering position in a recess in the sliding surface ( 26 ). 9. Clamping device according to claims 6 to 8, characterized in that the swivel sleeve ( 23 ) has on its underside bolt-shaped projections ( 30 ) on which push rods ( 31 ) a mechanical connection point ( 16 , 16 ') between the clamping tower ( 1 ) and Attack the connecting unit ( 12 ) by means of which the swivel sleeve ( 23 ) can be rotated. 10. Clamping device according to one of the preceding claims, characterized in that the clamping head ( 14 ) has on its underside an annular collar ( 28 ) which, when the clamping head ( 14 ) is fastened to the connecting unit ( 12 ), fits in its annular groove ( 22 ) intervenes. 11. Clamping device according to claims 6 to 10, characterized in that the clamping head ( 14 ) in the assembled state is connected to the swivel sleeve ( 23 ) of the connecting unit ( 12 ) and can be rotated out of its clamping position by means of this. 12. Clamping device according to one of the preceding claims, characterized in that the clamping head ( 14 ) has a clamping rod ( 7 ) which is arranged pivotably in a self-aligning bearing ( 29 ) and rotatable about its longitudinal axis ( 46 ). 13. Clamping device according to claim 12, characterized in that the clamping rod ( 7 ) is at one end in the assembled state with the pressure bolt ( 17 ) of the connecting unit ( 12 ) in connection. 14. Clamping device according to claim 12 or 13, characterized in that the clamping rod ( 7 ) has an exchangeable head element ( 8 ) at its other end. 15. Clamping device according to claims 12 to 14, characterized in that the clamping rod ( 7 ) when deflected by the pressure bolt ( 17 ) can be deflected against a spring load. 16. Clamping device according to claim 15, characterized in that the clamping rod ( 7 ) rests on a path-limiting end stop ( 37 ) when the pressure is released by the spring load. 17. Clamping device according to claim 15 or 16, characterized in that the spring loading is realized by a spring-loaded pin ( 35 ) arranged on the pressurized end of the tensioning rod ( 7 ), which with its rounded end in a V-shaped groove ( 36 ) on the housing the clamping head ( 14 ) is arranged. 18. Clamping device according to claims 12 to 17, characterized in that a workpiece ( 6 ) between the head element ( 8 ) of the clamping rod ( 7 ) and the base plate ( 9 ) by hydraulic action of the piston ( 18 ) can be clamped.