EP4132757A1

EP4132757A1 - Clamping device for workpieces

Info

Publication number: EP4132757A1
Application number: EP21719046.1A
Authority: EP
Inventors: Paul Gurka; Jörg WIEDERROTH
Original assignee: Michael Weinig AG
Current assignee: Michael Weinig AG
Priority date: 2020-04-09
Filing date: 2021-04-09
Publication date: 2023-02-15
Also published as: DE102020002319A1; WO2021204417A1

Abstract

The clamping device for workpieces (1) made of wood, plastic, aluminum, and the like has at least one lower and at least one upper clamping jaw (12, 13) as well as at least one drive (14) for adjusting the upper and/or lower clamping jaw (12, 13) in the clamping direction (z-direction) and for producing a clamping force acting on the workpieces (1). At least two drives (14) are provided for the upper and/or lower clamping jaw (12, 13), said drives generating respective individual clamping forces independently of each other. Elongated workpieces (1) can thereby be securely clamped using a simple and inexpensive design.

Description

CLAMPING DEVICE FOR WORKPIECES

The invention relates to a clamping device for workpieces made of wood, plastic, aluminum and the like according to the preamble of claims 1 and a system with such a clamping device according to claim 9.

Elongated workpieces, as used in particular in wooden window construction, are clamped with several driven clamping jaws above a certain length in order to ensure a reliable hold of the workpiece and to apply uniform surface pressure to the workpiece over the workpiece length. The clamping pressure must be selected so that the workpiece is securely held for machining.

However, the clamping pressure must not be so high that the clamping jaws leave impressions on the workpiece. The clamping jaws must be spaced from one another in such a way that the workpiece is held during machining, especially on its long sides, in such a way that it does not slip or vibrate as a result of the machining forces. For this purpose, a certain distance between the clamping jaws must not be exceeded. This free distance between the clamping jaws is approximately 500 mm in practice. With a usual length of elongated workpieces of around 3 m, 6 to 7 individual clamping jaws are necessary.

In addition, depending on the length of the workpiece, the workpiece must be positioned in such a way that the freely protruding end is, for example, no longer than about 200 mm, otherwise this free end will begin to vibrate during machining. Care must also be taken that the clamping jaws at the two ends of the workpiece do not rest on the workpiece with such a small area that the surface pressure becomes too high. To that

CONFIRMATION COPY To counter this, either a large number of individual clamping jaws lying close behind one another or which can be positioned along the length of the workpiece must be used, which, however, leads to additional machine costs. Since positionable clamping jaws have to be provided with an associated drive, the clamping device and a system having such a clamping device are correspondingly expensive.

The invention is based on the object of designing the generic clamping device and the system in such a way that elongate workpieces can be securely clamped with a multiple and inexpensive design.

This object is achieved with the generic clamping device according to the invention with the characterizing features of claim 1 and with the system according to the invention with the features of claim 9.

The clamping device according to the invention is characterized in that at least two drives are provided for the upper and / or lower clamping jaw, which can apply an individual clamping force independently of one another, in order to achieve the clamping force. This makes it possible to apply force to the clamping jaw in such a way that the surface pressure on the workpiece remains essentially constant over the length of the workpiece, regardless of the available clamping surface.

The use of at least two drives makes it possible to design the upper and / or the lower clamping jaw in such a way that they have such an extension in the longitudinal direction of the workpieces that a large part of the elongated workpieces to be manufactured can be clamped over their entire length. The upper clamping jaw can be made narrow in order to minimize interference or collision areas with the tool during machining. Due to the narrow and therefore slender design, the length of the clamping jaw is not so stiff that the surface pressure is applied evenly, for example by using only one drive can be. By using at least two drives that independently apply a clamping force, however, an approximately uniform surface pressure can be achieved.

The majority of the workpieces are in the range of 0.5 m to 3 m in common window parts. For example, the lower and upper clamping jaws have a length of 3 m, so that they extend completely over workpieces with a maximum length of 3 m. Workpieces whose length exceeds the length of the clamping jaws can still be machined by clamping them a second time offset in the longitudinal direction. In the case of short workpieces, several can be clamped at once if necessary. Depending on the application and the workpiece lengths to be processed, the size of the system and, in particular, the length of the clamping jaws can be different.

In order to achieve a uniform pressure distribution over the length of the workpiece, it is advantageous if at least one of the drives is force-controlled, that is, that it can apply a variable clamping force.

An advantageous embodiment results when three drives are provided for adjustment, one of which is arranged approximately halfway along the length of the clamping jaw. With such a design, the workpieces are advantageously clamped symmetrically from the center of the clamping device, that is to say from half their length. The middle drive is equipped with a certain clamping force. The two outer drives are then advantageously jointly set to a certain clamping force, taking into account the workpiece length, the resulting lever ratios with regard to the positions of the drives and advantageously the weight of the clamping jaw. In this way, the surface pressure on the workpiece can be kept approximately constant over its entire length. It is advantageous here if the three drives are arranged at equal distances from one another. A uniform surface pressure can then be achieved in a simple manner over the length of the workpiece.

If the workpieces are not aligned and clamped symmetrically to the clamping device, the position of the workpiece in the clamping device and the lever ratios resulting from the position of the workpiece in relation to the positions of the drives can advantageously be taken into account to adjust the clamping force of the individual drives .

The use of three drives makes it possible to apply a slightly lower force to the two outer drives, since the outer drives act proportionally on a smaller clamping surface.

The use of only at least two drives for the long workpieces enables the workpieces to be clamped very economically, with the workpiece being fixed with a uniform clamping force despite the small number of drives or clamping jaws.

In an advantageous embodiment, the drives are part of an adjustment unit. With it, the clamping jaws can be adjusted transversely to the longitudinal direction of the workpieces in the y-direction. This makes it possible, for example, to adjust the clamping jaws to the width of the workpieces.

The drives can work electrically, pneumatically, hydraulically or the like. The drives piston-cylinder units, which are subjected to a pneumatic pressure, are advantageous. The clamping force is then set by specifying and regulating the pneumatic pressure for a given cylinder / piston diameter. Depending on the structural arrangement, the drives can aufwei sen cylinders with different diameters in order to be able to set an optimal clamping force. The clamping length of the upper and / or lower clamping jaw is advantageously at least 0.5 m, preferably at least 1.0 m, in particular at least 1.5 m.

In a further advantageous embodiment, one clamping jaw, preferably the upper clamping jaw, has two clamping jaw parts lying one behind the other, between which there is a central clamping jaw element which is hinged to the two clamping jaw parts. This advantageously ensures that workpieces of different heights can be clamped with the two jaw parts so that the jaw parts rest over their length on these workpieces that they rest on the workpieces over their length.

The middle clamping jaw element is preferably designed as a rocker which can be pivoted about an axis lying in the y-direction. As a result, the two clamping jaw parts linked to them can be adjusted relative to one another in the z-direction with the middle clamping jaw element by a simple pivoting movement so that they lie flat on the workpieces of different heights.

If the middle jaw element is not pivoted, then it forms, together with the hinged jaw parts, a continuous jaw with which the workpieces can be clamped in the x-direction over their length.

Here, the design is advantageously designed so that the jaw parts and the middle jaw element form a continuous clamping surface.

The system according to the invention with the Spanneinrich device according to the invention is characterized by its structurally simple structure. In addition, is this system is also inexpensive to manufacture because of its simple structure.

The subject of the application results not only from the subject matter of the individual patent claims, but also from all information and features disclosed in the drawings and the description. Even if they are not the subject of the claims, they are claimed as being essential to the invention insofar as they are new to the state of the art individually or in combination.

Further features of the invention emerge from the further claims, the description and the drawings.

The invention is explained in more detail below with reference to an embodiment shown in the drawings. It shows

1 shows a perspective view of a system according to the invention with a clamping device according to the invention,

2 shows a clamping device according to the invention in an enlarged and perspective view,

3 shows a perspective view of part of the system according to the invention,

Fig. 4 in an enlarged view and partially in section, a tool changing device of the system according to the invention,

5 to 9 each different phases in the clamping and alignment of workpieces for processing in the system, FIG. 10 shows, in a representation corresponding to FIG. 1, a system according to the invention with a clamping device for flat workpieces,

Fig. 11 to

Fig. 13 different steps when introducing the sheet-like work piece into the system,

14 shows a side view of a further embodiment of a clamping device according to the invention of the system according to the invention,

15 shows a part of the clamping device according to FIG. 14 in a perspective and enlarged illustration.

In the system described below, elongated workpieces are processed, which can advantageously consist of flolz, but also of plastic, aluminum or a similar material.

The workpieces have a rectangular cross-section and are fed on a feed device 2 transversely to their longitudinal direction in the y-direction. For this purpose, the feed device 2 is seen ver with at least one transport unit 3, with which the workpieces 1 are transported transversely to their longitudinal direction in the system. The workpieces 1 to be processed can be placed on the feed device 2 by hand. However, an automatic workpiece feed is also possible.

The transport unit 3 can be formed, for example, by transport belts which extend in the y-direction and on which the workpieces 1 rest when they are fed into the system.

The feed device 2 has at least one support table 4 on which the workpieces 1 are placed. As soon as the workpieces 1 leave the support table 4, they are picked up by the transport unit 3 and transported transversely to their longitudinal direction. The feed device can have several transport units 3 lying next to one another, for example several to be able to transport adjacent workpieces 1 at the same time.

The workpieces 1 are fed to two clamping devices 5a, 5b with which the workpieces 1 are clamped at the top and bottom who the.

The clamping devices 5a, 5b each have at least one, in the exemplary embodiment three clamping carriages 6a to 6c, 7a to 7c, each having upper clamping jaws 8a with which the workpieces 1 are clamped in a known manner against lower clamping jaws 8b. The clamping carriages 6a to 6c, 7a to 7c can be individually positioned in the x direction according to the length of the workpieces 1. Depending on the design of the system, the number of clamping devices 5a, 5b and clamping carriages 6a to 6c, 7a to 7c can vary. Depending on the workpiece length, a different number of clamping carriages 6a to 6c, 7a to 7c can form the clamping device 5a, 5b. The individual clamping device 5a, 5b is defined within the scope of the exemplary embodiment in such a way that a single workpiece 1 is clamped in a clamping device 5a, 5b. The clamping carriages 6a to 6c, 7a to 7c can be of different widths (in the longitudinal direction of the workpieces), so that a workpiece can only be clamped in one clamping carriage 6a to 6c, 7a to 7c. Correspondingly, the tensioning device 5a, 5b in this case consists of one tensioning carriage 6a to 6c, 7a to 7c.

The tensioning carriages 6a to 6c, 7a to 7c can be moved in the x direction along a guide 9. The elongated workpieces 1 extend in the x direction, the transport direction.

The clamping carriages 6a to 6c, 7a to 7c arrive in a transfer area 10 in which the workpieces 1 can be taken over by a second clamping device 11. The clamping device 11 has a lower clamping jaw 12 for the workpieces 1 (FIG. 2), on which the workpieces 1 rest in the clamped state. The clamping jaw 12 extends in the x direction over approximately the length of the clamping device 11.

To clamp the workpieces 1, an upper clamping jaw 13 is used, which extends in the x-direction over the length of the clamping device 11 and is connected to at least two drives 14, in the exemplary embodiment with three drives 14 spaced one behind the other in the x-direction which the upper jaw 13 can be adjusted in the z-direction.

The drives 14 each have a carrier 14a to which the clamping jaw 13 is attached and which can be adjusted in the z direction along a guide (not shown). The drive 14 is preferably a piston-cylinder unit with which the clamping force is generated. The piston-cylinder unit has the cylinder 15 which is attached to a carrier 16. The carrier 14a, which is firmly connected to the clamping jaw 13, is connected to a piston rod 17 which can be displaced in the z-direction in order to adjust the upper clamping jaw 13 in the z-direction.

The drives 14 are parts of adjustment units 18 which have the carrier 16 and which can be moved in the z-direction together with the drives 14.

The adjustment units 18 are provided in a further adjustment unit 19 which have z-guides 20 for the carrier 16 of the drives 14.

The adjustment units 19 can be moved on guides 21 extending in the y direction. To drive the adjustment units 19, a drive 22 (FIG. 1) is provided in order to move the adjustment units 19 in the y-direction. This travel axis is designed as a positioning axis, so that the clamping jaws 12, 13 for the takeover of the work to be described below. Pieces 1 can be set exactly in the y-direction in the clamping device 11.

The drive 22 has a drive motor 23 with a motor shaft 24 lying in the y-direction, which is drive-connected via endless drives 25 to adjusting spindles 26 extending in the y-direction. With them, the adjustment units 19 can be moved in the y direction.

The workpieces 1 to be processed are fed via the feed device 2 and the transport unit 3 (FIG. 1) in the y direction to the clamping devices 5a, 5b, which are located in a loading area 27 of the system. In this area, the workpiece 1 can be pushed against a spring-loaded counter-stop 28 (FIG. 5) in the y-direction and clamped with the clamping jaws 8a, 8b of the clamping carriages 6a to 6c, 7a to 7c. It is not necessary here to clamp the workpiece 1 in an exact and positionally precise manner. The depth dimension in the y-direction depends on the width of the workpiece 1, which is pushed in by means of a slide that engages behind the workpiece 1 and executes a defined stroke or path. It is limited by the maximum end position of the counter-stop 28. The workpiece 1 can also be twisted or odd or inclined on the clamping carriages 6a to 6c, 7a to 7c.

The transport unit 3 stands, for example, higher than the lower clamping jaws 8b, so that the workpieces 1, as shown for example in FIG. 5, are more likely to be tilted upwards on the protruding side than downwards. The retraction of the clamping device 11 can therefore take place in the y-direction without a previous z-stroke of the lower clamping jaws 8b.

After clamping the unprocessed workpieces 1, the transport unit is clocked off a small amount so that the underside of the work piece 1 comes free of it. The clamping devices 5a, 5b can then be transported along the guide 9 extending in the x direction into the transfer area 10, which also includes the processing area of the system forms. During this transport, the workpiece 1 is moved in its longitudinal direction, that is to say in the x direction.

5 shows an example of a workpiece 1 clamped at an angle and tilted between the clamping jaws 8a, 8b of the clamping device 5a. Only in the transfer area 10 is the workpiece 1 precisely aligned so that it can be clamped and machined with high accuracy in the transfer area 10 .

The upper clamping jaw 13 of the clamping device 11 located in the transfer area 10 is raised so far in the z-direction that the workpiece 1 can be retracted into the clamping device 11 in the x-direction and / or, if necessary, the clamping device 11 can be adjusted in the y-direction. If necessary, the lower clamping jaw 12 of the clamping device 11 is positioned slightly downwards during retraction, so that there can be no contact with the workpiece 1 and the resulting damage.

The workpieces 1 are clamped in the respective clamping device 5a, 5b when they are fed in such that their one long side 29 in the y direction over the clamping jaws 8a, 8b of the clamping carriages 6a to 6c, 7a to 7c in the direction of the clamping device 1 1 protrude. Since the workpiece 1 is clamped in the clamping device 5a, 5b at an angle, for example, the longitudinal side 29 of the workpiece 1 runs at a corresponding angle to the x-direction. If the workpiece 1, as shown by way of example, is also clamped in a tilted manner, then the longitudinal side 29 of the workpiece 1 is also at a small acute angle to the y-direction.

As soon as the clamping device 5a, 5b is in the transfer area 10 and is opposite the clamping device 11, the upper clamping jaws 8a of the clamping carriages 6a to 6c, 7a to 7c are raised in the z-direction (FIG. 6). The workpiece is completely exposed because the clamping jaw 13 of the clamping device 11 is also raised in the z-direction. Each clamping carriage 6a to 6c, 7a to 7c of the clamping devices 5a, 5b has at least one counter-stop 28, which can be clocked back and forth in two positions by means of a pneumatic cylinder and which acts as a spring-loaded counter-stop 28 in front of its position due to the application of pressure. In FIG. 3, the counter-stop 28 is in the retracted position in which it is at a distance from the workpiece 1. In the exemplary embodiment, each tensioning carriage 6a to 6c, 7a to 7c has a spring-loaded counter-stop 28 that can be moved forward and backward.

The distance measured in the y-direction between the opposing clamping devices 5a, 5b and 11 is set such that the workpiece 1 reaches the lower clamping jaw 12 of the clamping device 11 over part of its width.

Since the clamping jaws 8a, 13 are raised during the transfer or alignment of the workpiece 1, the workpiece 1 rests on the lower clamping jaws 8b, 12 without tension. It must be ensured that the lower clamping jaws 8b, 12 are at exactly the same height.

In the next step, the workpiece 1 is aligned so that it is positioned precisely for subsequent processing. For this purpose, the clamping device 5a, 5b is provided with the at least one spring-loaded counter stop 28 which can be moved in the y-direction. The counter-stop 28 has a stop surface 30 perpendicular to the support surface of the lower clamping jaw 8b, with which it comes to rest on the longitudinal side 31 of the workpiece 1 opposite the longitudinal side 29 when it moves the workpiece 1 in the y-direction (FIG. 7).

With the counter-stop 28, the workpiece 1 is pushed in the y-direction onto the lower clamping jaw 12 until the workpiece 1 rests with its longitudinal side 29 on a stop 32 of the clamping device 11 extending in the x-direction (FIG. 7), whose contact side is also perpendicular to the contact surface of the lower jaw 12. The stop 32 the clamping device 11 can be positioned in the y-direction. In this way, the position of the workpiece 1 can be set exactly for the subsequent machining.

The workpiece 1 is advantageously adjusted in such a way that it already assumes the position required for the subsequent machining of the longitudinal side 31 in the y-direction during this first clamping. Then the workpiece 1 does not have to be moved after the machining of one longitudinal side 29 and the transfer to the clamping device 11.

During the alignment process described, the workpiece 1 is brought into the exact position.

As soon as the precise positioning of the workpiece 1 has been carried out via the horizontal stops 28, 32, the upper clamping jaws 8a of the clamping carriages 6a to 6c, 7a to 7c are lowered in the z direction until the workpiece 1 is between the upper clamping jaws 8a and the lower ones Clamping jaws 8b is clamped. The clamping of the workpiece 1 is such that it protrudes in the y-direction in the direction of the clamping device 11 over the two clamping jaws 8a, 8b. In the exemplary embodiment, the workpiece 1 projects approximately over half its width over the clamping jaws 8a, 8b (FIGS. 8 and 9).

The clamped workpiece 1 rests with its longitudinal side 31 on the stop surface 30 of the counter-stop 28 of the clamping device 5a, 5b (FIGS. 8 and 9).

The stop 32 can be positioned in its y-position via a separate y-axis or by means of the y-axis of the clamping device 11.

In the exemplary embodiment, the stop 32 is arranged on the supports 16 of the adjustment units 18 and can be adjusted in three positions in the y-direction. To push off the finished workpieces 1, the beat 32 clocked forward in y-direction. The two precompacted positions of the stop 32 are used to align and push off the workpieces 1. The stop 32 is then returned to the third position when the workpiece 1 is to be transferred to the clamping device 11 for the second clamping for machining the longitudinal side 31. The stop 32 is then not in contact with the workpiece 1. In Fig. 6, the middle position of the stop 32 is shown.

As soon as the workpiece 1 is clamped in the clamping device 5a, 5b in the manner described, the clamping device 11 with the described adjustment units 19 (FIG Long side 29 processed with the appropriate tools, usually profiled or planed smooth.

In the area protruding over the clamping jaws 8a, 8b and in the areas lying between the upper and lower clamping jaws 8a, 8b, holes, grooves and the like can be made in the upper side 33 and / or the lower side 34 of the workpiece 1.

As soon as the workpiece 1 has been processed on its one longitudinal side 29 and possibly on its upper side and / or its lower side 34, the clamping device 11 is moved by means of the adjustment units 19 in the y-direction back into a position relative to the clamping device 5a, 5b in which the workpiece 1 is overlapped by the clamping jaws 12, 13 of the clamping device 11. This position of the two clamping devices 5a, 5b and 11 relative to one another corresponds approximately to the position as shown in Fig. 8 is Darge. In this position, in which the workpiece 1 being processed on one of its long sides 29 is still clamped in the clamping device 5a, 5b, the upper clamping jaw 13 of the clamping device 11 is lowered in the z-direction so far that the workpiece is in the over the clamping jaws 8a, 8b over standing area or on a previously processed area, for example in a fold, in which clamping device 11 is clamped. During this y-movement, the clamping device 11 is moved in the direction of the clamping device 5a, 5b until the clamping device 11 has reached the position that is optimal for optimal clamping and machining of the workpiece 1 on the longitudinal side 31.

During the transfer process, the workpiece 1 is not free at any time. In addition, the position of the workpiece 1 does not change, but remains stationary in the system. This ensures very precise machining of the workpiece 1, since in particular no axis positioning of the clamping device 11 has to take place.

As soon as the protruding part of the workpiece 1 is clamped in the clamping device 11, the upper clamping jaws 8a of the clamping carriages 6a to 6c, 7a to 7c are lifted in the z-direction, so that the workpiece 1 is no longer clamped by the clamping device 5a, 5b. The clamping device 5a, 5b is then moved back in the x direction to the transfer or loading area 27 in order to pick up the next workpiece 1 to be machined there.

Before this retraction, there is advantageously a small z-stroke (for example 3 mm) of the clamping device 11 upwards, or the clamping device 11 moves back in the y-direction so that the underside of the workpiece 1 does not move when the clamping device 5a, 5b is moved damaged.

So that a reliable transfer can take place between the clamping device 5a, 5b and the clamping device 11, it can also be advantageous if the lower clamping jaws 8b, 12 can be lowered slightly in the z-direction when moving into or out of the transfer position, so that it is ensured that the lower clamping jaws 8b, 12 do not come into contact with the support side of the workpiece 1 on which its surface could be damaged. The workpiece 1 is clamped in the clamping device 11 in such a way that it protrudes sufficiently far beyond the clamping jaws 12, 13 of the clamping device 11 in the y-direction. The not yet machined long side 31 of the work piece 1 can then easily be edited with the appropriate tool.

In the area of the upper side 33 or the lower side 34 of the workpiece 1 that is exposed, bores, grooves and the like can also be made with a corresponding tool.

The described sequence during clamping, transferring and machining of the workpiece 1 takes place in the same way with all clamping devices 5a, 5b. When machining two or more workpieces 1 at the same time, two or more clamping devices 5a, 5b can be used that execute the corresponding movements at the same time and in parallel, as has been explained with reference to FIGS. 5 to 9.

The two clamping jaws 12, 13 of the clamping device 11 extend over the entire length of the workpiece lengths customary in the area of application of the system. The upper clamping jaw 13 is driven in the z-direction by means of several drives 14 in the manner described. In the exemplary embodiment, three drives 14, which are arranged one behind the other at a distance in the x direction, are used for z adjustment of the upper clamping jaw 13. The clamping force required to clamp the workpieces 1 is applied with the drives 14.

The drives 14 can be electric, pneumatic, hydraulic or similar drives. They are advantageously the same distance from one another.

In order to enable even pressure distribution over the length of the clamping jaws 12, 13, at least one of the drives 14 is force-regulated. The lower clamping jaw 12, which normally forms the reference edge or reference surface for machining the workpiece 1, is made sufficiently rigid. This ensures high milling accuracy when machining the workpiece.

It is advantageous if the workpiece 1 or the workpieces 1 is or will be clamped symmetrically to the center of the clamping device 11. For this purpose, a certain force is exerted on the workpiece 1 with the middle of the three drives 14 via the clamping jaw 13. The two outer drives 14 are also set together to a certain clamping force. In this way, the surface pressure can be kept constant over the length of the workpiece 1.

It is possible to exert a somewhat higher clamping force on the workpiece 1 with the two outer drives 14 than with the central drive 14. As a result, the workpiece 1 is clamped more strongly in the region of its two ends than in the central region. The workpiece 1 as a whole can thus be optimally held in its position.

In order to generate the different forces, the clamping device 11 has several pressure circuits. In the exemplary embodiment, a pressure control valve 35 to 37 (FIG. 2) is assigned to each drive 14. With their help, the respective clamping pressure can be set on the drives 14 so that different clamping forces can be generated with the drives 14. In particular, if the workpieces 1 are not symmetrically positioned in the clamping device 1 1 or if the workpieces 1 are more or less unevenly curved, the clamping force can be adjusted over the length of the workpiece in such a way that optimal clamping is ensured. In particular, the effect of the weight of the upper jaw 13 can also be taken into account here. In principle, it is also possible for the two outer drives 14 to be acted upon by one pressure circuit and the middle drive 14 by another pressure circuit.

In the simplest case, the clamping device 11 has only two drives 14 for the upper jaw 13. In this case, the upper jaw 13 ge can optionally be formed slightly curved in the longitudinal direction to compensate for their deflection during clamping.

By using only two or three drives 14 for long workpieces 1, a very economical workpiece clamping is achieved, the workpiece 1 nevertheless being fixed with the lower clamping jaw 12 on the workpiece table with a uniform clamping force.

As has been explained in detail with reference to FIGS. 5 to 9, the clamping device 11 has the lateral stop 32 with which the clamping depth of the workpiece 1 can be determined. Since the lower jaw 12, like the upper jaw 13, extends over the length of the workpiece, the stop 32 can also go through the entire length of the clamping jaws 12, 13. In this way, with simple structural means, a high level of precision in the positioning of the workpiece 1 in the clamping device 11 or in the clamping device 5a, 5b can be achieved.

To adjust the stop 32 in the y direction, only one drive is required, since the stop points do not have to be flexible in length to each other.

As soon as the workpieces 1 are finished, ie have been processed accordingly at least on both longitudinal sides 29, 31, they are pushed onto a receiving unit 38 (FIG. 1). It has a support part 39 which extends horizontally and protrudes from a side wall 40 that adjoins vertically upwards. After finishing the workpieces 1, the receiving unit 38 is lowered until it is in the area below the clamped workpieces. Then the workpiece 1 after releasing the clamping voltage with the stop 32 of the clamping device 11 by a drive (not provided) is pushed onto the receiving unit 38 in the y-direction.

During the processing of the workpieces 1 in the transfer area 10, the receiving unit 38 is adjusted so far upwards that it does not interfere with the workpiece processing. After the finished work pieces 1 have been transferred to the receiving unit 38, the latter is adjusted upwards again in the z direction.

The receiving unit 38 is provided on a carrier designed as a portal 41, which can be moved in the x direction. The portal 41 has two uprights 42, 43 (FIG. 1) which can be moved on guides 44, 45 which extend in the x direction. The two uprights 42, 43 are connected to one another at the upper end by a cross member 46. To move the portal 41, a drive 47 is provided, which is arranged, for example, on the stand 43.

A slide 48 (FIG. 1), which can be moved in the z-direction, for adjusting the height of the receiving unit 38 is arranged on the cross member 46. To support the support part 39, two arms 49 are provided, one end of which is hinged to the receiving unit 38 and the other end to the slide 48.

With the portal 41, the receiving unit 38 is moved along the guides 44, 45 in the x direction so far that the workpieces 1 can be transferred from the receiving unit 38 to a discharge unit 50. It is provided in the area above the feed device 2. The receiving unit 38 is lowered in the z-direction. It has recesses 51 in which in the exemplary embodiment Belt tracks 52 of the discharge unit 50 protrude when the receiving unit 38 is lowered. The workpieces 1 deposited on the receiving unit 38 can thereby be grasped by the belt tracks 52 and removed from the receiving unit 38. The finished workpieces 1 are removed from the discharge unit 50 for further processing.

The two guides 44, 45 for the portal 41 are provided in such a way that the guide 9 for the clamping devices 5a, 5b lies in the area between the two guides 44, 45. As a result, the portal 41 can be moved in the x-direction and at the same time also the clamping devices 5a, 5b with the clamping carriages 6a to 6c, 7a to 7c in the x-direction, so that a time-parallel mode of operation is guaranteed.

In the exemplary embodiment, the guide 9 is provided close to the guide 44 of the portal 41. The stand 42 of the portal 41, which can be moved along the guide 44, is designed in such a way that it does not come into collision with the clamping devices 5a, 5b which can be moved along the guide 9.

The tools provided for machining the workpieces 1 are provided on the portal 41, which is moved along the guides 44, 45 for machining the workpieces 1.

A slide 53 is arranged on the cross member 46 such that it can be moved in the y direction. The slide 53 is advantageously arranged on the side of the cross member 46 facing away from the receiving unit 38. It has guides 54 extending in the y direction, along which the carriage 53 can be moved (FIG. 3). It carries a tool spindle 55, the axis of which runs in the z-direction and which in the exemplary embodiment is a motor spindle.

A tool 56 (FIG. 4) which is required for machining the workpieces 1 and which is made available in a magazine 57 is inserted into the lower end of the tool spindle 55. A linear magazine (Fig. 1), which has storage spaces 58 for the tools 56 arranged one behind the other in a row.

The tool spindle 55 is held on a spindle carrier 59 (FIG. 3) which can be moved in the z-direction with respect to the slide 53. The spindle carrier 59 can be adjusted in the z-direction by means of a drive 60 mounted on the slide 53.

The corresponding tool 56 can be moved to the desired extent in the x, y and z directions by means of the portal 41, the slide 53 and the spindle carrier 59. In this way, the corresponding sides of the workpiece 1 can be processed within the transfer area 10 in the manner described.

In order to remove the tools 56 from the tool magazine 57 and insert them into the tool spindle 55, the system is provided with a tool changing device 61 which is provided on the portal 41 and can be moved with it in the x direction.

With the tool changing device 61, the tools 56 required for machining the workpieces 1 can be removed from the magazine 57 and inserted into the tool spindle 55. Conversely, the respective tool 56 can be inserted into the magazine 57 with the tool changing device 61.

The tool changing device 61 has a plate magazine 62 with an axis 63 lying in the z direction, with which the plate magazine 62 can be rotated.

A star carrier 64 with radially extending arms 65, which are each provided with a receptacle 66 for tools 56 at the free end (FIG. 4), is seated in a rotationally fixed manner on the axis 63. The magazine 56 has the storage spaces 58 (FIG. 3), which are equipped with receptacles 67 corresponding to the receptacles 66 of the plate magazine 62.

The plate magazine 62 is part of a slide 68 (FIG. 3) which can be moved in the y direction along a transverse support 69 extending in the y direction. It is connected to the portal 41, in particular to its stand 42. As FIG. 3 shows, the cross member 69 is provided on one side with two guides 70 which extend in the y direction and which are spaced one above the other in the z direction. With the slide 68, the plate magazine 62 can be moved along the guides 70 into the respective transfer positions.

A cylinder unit 71, which is arranged above the cross member 69, is used for this purpose.

The tool changing device 61 is provided with a transfer unit 72 (FIG. 4) with which the tools 56 can be transferred from the magazine 57 to the plate magazine 62. The transfer unit 72 consists of a slide 73, a transfer part 74 and a drive 75.

The transfer unit 72 is provided on a holder 76, which is advantageously designed in the form of a plate and extends in the y direction. The holder 76 has a support element 77 which is fastened to the carriage 68.

In a further embodiment (not shown), the transfer unit 72 can be attached to the free end of the cross member 69.

The slide 73 can be moved in the y direction along the holder 76. A guide rail 78 for the slide 73 is located on the holder 76.

The slide 73 is adjusted via a piston-cylinder unit 79, the housing 80 of which is connected to the slide 73 and the piston rod 81 of which is connected to the holder 76. The transfer part 74, which can be adjusted in the z-direction, is accommodated in the slide 73. It is advantageously designed in the shape of a bolt and can be moved from a rest position to a transfer position. For this purpose, the drive 75 is provided, for example a pneumatic cylinder with which the transfer part 74 can be moved axially.

4 shows the transfer part 74 in its transfer position, in which it engages in an inner contour 82 of an interface 83 on the tool side. It is advantageously an HSK interface. It has a fitting diameter at the end of the cone and at a recess in the cone bottom, into which the bolt-shaped transfer part 74 can be inserted, whereby a tilt-free horizontal force can be exerted on the tool 56. This makes it possible to transfer the tool 56 from the receptacle 67 of the magazine 57 into the receptacle 66 of the plate magazine 62 without tilting.

In the area of the interface 83, the tool 56 has a gripper groove 84 which extends over the circumference of the interface 83 and into which legs 85, 86 engage, which delimit the receptacles 66 in the plate magazine 62 and the receptacles 67 in the magazine 57. The legs 85, 86 are formed in such a way that they engage in the gripper groove 84 in a form-fitting and advantageously non-positive manner. The tool 56 is thereby supported in the axial direction both in the magazine 57 or the plate magazine 62 and during the transfer, so that there is no risk of it falling down.

It is advantageous if the transfer part 74 is designed in such a way that when the transfer part 74 is retracted, the inner contour 82 of the interface 83 is blown out. The corresponding bore can be provided in the transfer part 74.

It is also possible to provide at least one blow nozzle separately on the side of the transfer unit 72 for the supply of the blow air, through which a blow jet passes, with which chips are removed from the bore of the tool 56. blown or sucked.

In order to pick up the tool 56 from the magazine 57, the slide 73 is moved in the y-direction on the cross member 69 in the direction of the magazine 57. The plate magazine 62 is aligned in the x direction by moving the portal 41 in relation to the tool 56 to be taken over and the star carrier 64 is rotated about the vertical axis 63 of the plate magazine 62 so that the receptacles 66, 67 of the plate magazine 62 and of the magazine 57 face each other. The transfer part 74 is withdrawn so far that it does not come into contact with the tool 56 when the slide 73 is moved.

In order to transfer the tool 56 from the magazine 57 to the plate magazine 62, the transfer part 74 of the transfer unit 72 is shifted downward in the z-direction until it engages the inner contour 82 of the interface 83 of the tool 56 (FIG. 4).

If the slide 73 with the transfer part 74 engaging in the tool 56 is moved in the y-direction in the direction of the portal 41, the tool 56 is pressed into the receptacle 66 of the plate magazine 62. The carriage 68 can now be moved together with the plate magazine 62 and the transfer unit 72 along the guides 70 in the y-direction in the direction of the portal 41. The transfer part 74 is withdrawn into the transfer position before, during or after travel, so that it is released from the tool 56. The plate magazine 41 is then rotated by 180 ° in such a way that the tool 56 is positioned in the area below the tool spindle 55 provided on the portal 41. It is then moved so far down in the z-direction that the tool 56 is received in the tool spindle 55 and clamped by means of an HSK clamping system known per se.

Flat or curved workpieces 87 can also be processed in the system, as is shown by way of example in FIGS. 1 and 10 to 13 for a flat Chen-shaped workpiece is shown. It is positioned on a workpiece carrier 88, for example as specified by the system control. The sheet-like workpiece 87 can be held on the workpiece carrier 88 by means of clamps and suction cups 89 (FIG. 10).

The workpiece carrier 88 is located on a carriage 90 which can be brought up to the system by means of wheels 91. On the carriage 90 there is a guide 92, preferably a guide 92 on each side, along which the workpiece carrier 88 can be displaced.

Since the carriage 90 is mobile, the workpiece 87 can be clamped on the workpiece carrier 88 at a set-up station, for example. The carriage 90 with the clamped workpiece 87 is then moved up to the system (FIG. 12) in such a way that the guide 92 can be docked to a guide system 93 of the system after a protective machine cover has been opened. The guide system 93 extends in the transfer area 10 of the system in the y-direction and advantageously also consists of a guide 93 on both sides Workpiece 87 can be pushed into the system.

Before the workpiece carrier 88 with the clamped workpiece 87 is moved into the system, the clamping device 11 is lowered so far in the z-direction that the workpiece carrier 88 can freely pass over the lowered clamping device (FIG. 12). Alternatively or additionally, the guide track 93 can be raised in the system. The travel portal 41 and the clamping units 5a, 5b are located outside the transfer area 10, so that the workpiece carrier 88 with the clamped workpiece 87 can be brought into the system without collision.

In the exemplary embodiment, the workpiece carrier 88 is pushed into the system by hand. However, this can also be done via a drive. The workpiece carrier 88 can advantageously also be lowered onto the carriage 90 in order to allow the operator an ergonomically good working position when placing and aligning the workpieces 87.

After the carriage 90 has moved away and the machine protection cover has been closed, the workpiece carrier 88 is lowered so far that the workpiece 87 reaches the required processing position. The workpiece 87 can be positioned at a similar height to the elongated workpieces 1 for machining within the transfer area 10. With the tool inserted into the tool spindle 55, the workpiece 87 can be machined in a known manner. The portal 41 can move over the guide system and the workpiece carrier 88 with the clamped workpiece 87 without collision.

The machining of the flat or curved workpieces 87 takes place in the same way as the machining of the elongated workpieces 1 in the transfer area 10 or the machining area of the system.

The workpiece carrier 88 is locked in its position, for example, by index bolts 95, which are arranged on the longitudinal sides of the workpiece carrier 88 and protrude downward from it in the z-direction. In order to lock the workpiece carrier 88, the guide system 93 is indexed in the z direction together with the workpiece carrier 88. The index bolts 95 are inserted into fixed recesses 96 (FIG. 13).

Separately clocked locking devices that securely connect the workpiece carrier 88 to the machine frame at required positions would also be possible.

Additional index bolts (not shown) can enable the workpiece carrier 88 to be fixed in the y-direction. These index bolts can be attached to the clamping device 11 and / or in the area of the the guide track 9 can be provided and engage in bores in the workpiece carrier 88.

The guide system 93 is so long that the workpiece carrier 88 is completely on the guide system 93 in the positioned position (FIG. 13). The carriage 90 can therefore be moved away after the workpiece carrier 88 has been transferred to the guide system 93 in order to arrange the next workpiece carrier 88 on it and to clamp the next workpiece 87 on it.

As is shown by way of example in FIG. 10, the clamps or suction cups 89 are arranged distributed over the width and length of the workpiece carrier 88. For example, the suction cups 89 can be arranged in rows at a distance from one another, as FIG. 10 shows by way of example.

It is possible to operate the suction cups 89 individually so that, depending on the size of the sheet-like workpiece 87, only the suction cups 89 required are actuated.

A further advantageous embodiment consists in training the suction cups 89 in such a way that they are arranged displaceably on the workpiece carrier 88. The position of the suction cups 89 can then be optimally adapted to the shape of the sheet-like workpieces 87. In particular, the workpiece 87 can also be easily positioned on the workpiece carrier 88 in this way.

Since the suction cups 89 are advantageously variably displaceable and can be arranged individually on the workpiece carrier 88, the worker can position the suction cups 89 exactly as specified by the machine control system, for example.

This positioning can be carried out particularly advantageously when the workpiece carrier 88 is divided into a chessboard pattern and the coordinates th of the positions of the suction cups 89 are specified. It is also possible, for example, for the positions of the suction cups 89 on the workpiece carrier 88 to be marked by a laser. In this case, the carriage 90 is at a defined position.

While the carriage 90 is being set up, the angular workpieces 1 can continue to be processed in the system in the stack processing or another workpiece on a second workpiece carrier.

In order to be able to move a heavy sheet-like workpiece 87, for example a door leaf, on the suction cups 89, the suction cups 89 can advantageously be designed so that they are operated with compressed air instead of a vacuum during the movement at the interface to the workpiece 87 they can be switched to compressed air operation. Then compressed air is generated, which forms an air cushion on which the workpiece 87 can be easily pushed ver. On the side facing the workpiece carrier 88, they are held in a manner to be described.

Since the carriage 90 can be placed at any desired place outside the system, there is the possibility of arranging the carriage 90 in such a way that the workpiece carrier 88 is accessible from all sides. As a result, a heavy workpiece can easily be placed by two people, for example. A tool, such as a workshop crane, is then not absolutely necessary.

The workpiece carrier 88 or the carriage 90 is advantageously provided with stops 94, 94a in two horizontal directions (x and y directions) against which the unprocessed workpiece 87 can be placed (FIGS. 1 and 10).

So that the suction cups 89 do not move unintentionally on the workpiece carrier 88, the workpiece carrier 88, but at least its support side, can be formed by a steel plate. The suction cups 89 are equipped with th equipped, by means of which the suction cups can be held firmly on the workpiece carrier 88.

However, it is also possible to apply a negative pressure to the suction cups 89 or to the workpiece carrier 88 and in this way to fix the suction cups 89 on the workpiece carrier 88.

It is basically possible that the carriage 90 and the system each have their own vacuum and / or pneumatic supply and that the corresponding lines are manually plugged into the system after the workpiece carrier 88 has been inserted. It is also possible that, for example, when the workpiece carrier 88 is lowered, the corresponding pneumatic connections are separated or connected automatically.

The machining of curved workpieces is carried out in the same way.

14 and 15 show a second embodiment of the Spanneinrich device 11. It has the lower jaw 12, which extends in the x direction over et wa the length of the clamping device 11 and on which the workpieces 1 in the manner described in the clamped state rest. The upper clamping jaw 13, which is used to clamp the workpieces 1 and which extends in the x direction, consists of two clamping jaw parts 13a, 13b. They lie one behind the other in the x direction and are connected to one another by a rocker 97. The rocker is mounted pivotably about an axis 98 lying in the y-direction.

The rocker 97 has arms 99, 100 extending on both sides of the pivot axis 98 in the x direction, which are arranged behind the mutually facing ends of the clamping jaw parts 13a, 13b. The rocker arms 99, 100 are articulated to the adjacent ends of the clamping jaw parts 13a, 13b via two axes 101, 102 each extending in the y direction. The rocker 97 can also serve as a clamping element. When the rocker 97 assumes its central position, its clamping surface 103 then lies in a plane with the clamping surfaces 104, 105 of the clamping jaw parts 13a, 13b. In this case, the clamping jaw parts 13a, 13b and the rocker 97 form a continuous clamping jaw with a continuous clamping surface 103 to 105.

The rocker 97 makes it possible to clamp workpieces of unequal height with the clamping device 11 in such a way that these workpieces are clamped over their length by the clamping jaw parts 13a, 13b.

In the illustrated embodiment, the workpiece 1 between the clamping jaw part 13a and the lower clamping jaw 12 has a slightly greater height than the workpiece 1 between the clamping jaw part 13b and the lower clamping jaw 12. The rocker 97 enables by a pivoting movement about its pivot axis 98 that the two Clamping jaw parts 13a, 13b are arranged offset from one another in such a way that they each rest completely on the workpieces over the length of the corresponding workpiece 1. The rocker 97 assumes an inclined position, as FIG. 14 shows.

In the same way, the rocker 97 can also pivot in the other direction, so that a higher workpiece 1 can be clamped with the clamping jaw part 13b than with the clamping jaw part 13a.

The pivoting movement of the jaw parts 13a, 13b with respect to the rocker arms 99, 100 is limited by the two axes 101 and 102, respectively.

The axes 101, 102 are advantageously formed by screws, the heads of which are countersunk in bores 106, 107 in the rocker arms 99, 100 (FIG. 15). The arrangement is made such that the screw heads with air lie in the bores 106, 107. A pivoting movement of the jaw parts 13a, 13b with respect to the rocker 97 is only possible within the scope of the Boh approximate air. Due to the swivel movement, a flawless flat chige support of the clamping jaw parts 13a, 13b on the workpieces 1 is assured.

The rocker 97 is connected via its pivot axis 98 to the drive 14 with which the rocker 97 can be adjusted in the z-direction. The rocker 97 is held at the upper end of the carrier 14 a of the drive 14. The ends of the clamping jaw parts 13a, 13b facing away from the rocker 97 are connected to the two outer drives 14 in FIG. 14.

The operation of the drives 14 is the same as in the previously described embodiment.

Since the clamping jaw parts 13a, 13b can only pivot to a small extent, as described above, those workpieces 1 which reach little below the clamping jaw parts 13a, 13b are not clamped too much on the edge.

If two workpieces 1 are clamped simultaneously in the clamping device 11, they are arranged in such a way that they are only under the clamping jaw parts 13a, 13b and not under the rocker 97 (FIG. 14).

Individual parts are placed and clamped symmetrically to the center in the x-direction. Very short workpieces that are shorter than 230mm, for example, are only clamped with the rocker 97.

In this case, the rocker 97 is adjusted in the z-direction with the drive 14 in order to clamp this short workpiece between the rocker 97 and the lower clamping jaw. Longer individual workpieces are clamped with the rocker 97 and the clamping jaw parts 13a, 13b.

The fastening of the clamping jaw parts 13a, 13b with the drives 14 at the ends facing away from one another is advantageously also carried out flexibly by means of screws with little hole clearance and contact pressure by means of springs, preferably disc springs. As a result, there is limited mobility of the Jaw parts 13a, 13b are possible in the x and z directions, for example for length compensation when the rocker 97 is pivoted.

Claims

Expectations

1. Clamping device for workpieces made of wood, plastic, aluminum and the like, with at least one lower and at least one upper clamping jaw and with at least one drive for adjusting the upper and / or lower clamping jaw in the clamping direction (z-direction) and for generating a clamping force the workpieces, characterized in that at least two drives (14) are provided for the upper and / or lower clamping jaws (12, 13), each of which generates an individual clamping force independently of one another.

2. Clamping device according to claim 1, characterized in that at least one of the drives (14) is force-controlled.

3. Clamping device according to claim 1 or 2, characterized in that three drives (14) are provided, of which one drive (14) is arranged approximately half the length of the clamping jaw (12, 13).

4. Clamping device according to claim 3, characterized in that the drives (14) are arranged at equal distances from one another.

5. Clamping device according to one of claims 1 to 4, characterized in that the drives (14) are part of an adjusting unit (19) with which the clamping jaws (12, 13) are adjustable in the y-direction.

6. Clamping device according to one of claims 1 to 5, characterized in that the one clamping jaw (12, 13), preferably the upper clamping jaw (12), has two clamping jaw parts (13, 13a) lying one behind the other, between which there is a middle res clamping jaw element (97) is located, which is hinged to the two clamping jaw parts (13, 13a).

7. Clamping devices according to claim 6, characterized in that the middle clamping jaw element (97) is designed as a rocker which is pivotable about an axis (98) lying in the y-direction.

8. Clamping device according to one of claims 1 to 8, characterized in that the clamping length of the upper and / or lower clamping jaws (12, 13) is at least 0.5 m, preferably at least 1 m, in particular at least 1.5 m.

9. Plant for processing workpieces made of wood, plastic, aluminum and the like with a clamping device according to one of claims 1 to 8.