DE102018117011A1 - Workpiece clamp, machining device and clamping method - Google Patents

Abstract

Workpiece clamp (1) for clamping workpieces, which preferably consist at least in sections of wood, wood materials, plastic or the like, comprising: a first clamping element (2) and a second clamping element (4), each of which has a clamping surface (2 ', 4') to clamp a workpiece between the clamping surfaces, the first and second clamping elements (2 ', 4') being movable relative to each other between a clamping position and an opening position, and a locking device (10) which detects the maximum distance between the clamping surfaces ( 2 ', 4'), the locking device (10) being unlockable in order to set the maximum distance between the clamping surfaces (2 ', 4'), characterized in that the workpiece clamp has a securing device (20) which is set up a to prevent unwanted unlocking of the locking device (10).

Description

Technical field

The invention relates to a workpiece clamp according to the preamble of claim 1, as well as a machining device with such a workpiece clamp and a clamping method using such a workpiece clamp.

State of the art

When machining workpieces, they are usually fixed with suitable clamping devices, for example on a machining table or a conveyor. A wide variety of workpiece clamps are used for this purpose, for example in the furniture and component industry often pneumatically or optionally also hydraulically operated workpiece clamps are used. A workpiece clamp of the type in question here is, for example, in FIG DE 10 2014 216 638 A1 disclosed.

When using pneumatic or hydraulic clamping devices, strict safety regulations apply, for example with regard to finger pinch protection. For example, the gap between the clamping surfaces of a clamping element must usually not exceed a certain dimension, so that fingers cannot be pinched before the clamping process is initiated. For this purpose, workpiece clamps are known in which the maximum distance between the clamping surfaces can be set or limited in order to meet the safety requirements. However, known workpiece clamps are not very user-friendly and also have room for improvement in operational safety.

Presentation of the invention

It is therefore an object of the invention to provide a workpiece clamp of the type mentioned at the outset which is easy to operate with high operational reliability.

This object is achieved by a workpiece clamp according to claim 1. In addition, the invention provides a processing device according to claim 11 and a clamping method according to claim 12. Particularly preferred embodiments of the invention are specified in the dependent claims.

The workpiece clamp according to the invention is characterized in that it has a securing device which is set up to prevent undesired unlocking of the locking device. In this way, the operational safety of the workpiece clamp according to the invention can be increased considerably, since even with frequent adaptation of the maximum distance between the clamping surfaces, it is ensured that the locking device is actually locked and that an enlarged gap does not inadvertently arise, which entails a considerable risk of injury, in particular by squeezing fingers. At the same time, the user-friendliness is retained, since the security device is directly linked to the locking device.

This direct link with corresponding user-friendliness results in particular if, according to a development of the invention, the securing device has a securing element which can be fixed in a securing position in which an undesired unlocking of the locking device is prevented.

In addition, according to a development of the invention, it is provided that the securing device has an actuating element which is set up to fix the securing element in the securing position. This further increases the user-friendliness, since the actuating element enables an operator to easily access it.

It is particularly preferred that the actuating element can be operated without tools. As a result, the operator does not always have to carry a suitable tool with him and place it in the right place, but can directly - for example with one hand - actuate the securing device in order to unlock or lock the locking device. This also has the advantage that the operator then "still has one hand free" with which he can, for example, adjust the maximum distance between the clamping surfaces before the locking device is locked again by means of the securing device. All in all, this results in a drastically increased user friendliness combined with high operational reliability.

The actuating element can be designed in a wide variety of ways within the scope of the invention. To achieve tool-free operability, it is provided according to a development of the invention that the actuating element has at least one load application point for an operator, the lever arm of which is preferably at least ten times larger than a lever arm, in particular radius, of the securing element. This ensures that a sufficient force or torque can also be applied manually to the actuating element, so that the securing device is adequately secured, but is nevertheless easy to use or operate. The actuating element can for example be a disc and / or one Have levers to provide the at least one load application point. This gives the actuating element a very simple construction with a high degree of user-friendliness.

Alternatively or additionally, it is provided according to a further development of the invention that the securing element is set up to unlock the locking device by means of a lifting movement as soon as it is released by the actuating element. This results in a two-stage operating concept of the securing device, in which the securing element is first released, preferably manually, by actuating the actuating element, and then the locking device is actually unlocked by a lifting movement of the securing element. This means that an undesired unlocking of the locking device is practically impossible, while the user friendliness remains high.

These advantages are particularly pronounced if, according to a further development of the invention, the actuating element is arranged in such a way that, when actuated by a user, a lifting movement of the securing element is caused.

In addition, according to a development of the invention, it is provided that the workpiece clamp has a scale in order to facilitate the setting of the maximum distance between the clamping surfaces. This measure also increases both the operational reliability and the user-friendliness of the workpiece clamp according to the invention.

Furthermore, it is provided according to a development of the invention that the workpiece clamp has an actuator that is set up to move at least one clamping element between the open position and the clamping position. This results in a simple and effective clamping process.

The advantages mentioned above are particularly pronounced when the workpiece clamp according to the invention is used in a processing device according to claim 11.

In the clamping method according to the invention according to claim 12, the workpiece clamp according to the invention is also used. This is characterized by first defining a workpiece to be clamped and then determining the workpiece thickness to be clamped. On this basis, it is checked whether the maximum distance between the clamping surfaces exceeds the workpiece thickness of a maximum gap dimension. If this is the case, the maximum distance between the clamping surfaces is reduced accordingly. Operational safety can thus be increased in a simple manner.

It is particularly preferred that, in order to reduce the maximum distance between the clamping surfaces, the locking device is first unlocked by means of the securing device in order to subsequently reduce or set the maximum distance between the clamping surfaces. Finally, the locking device is locked again by means of the securing device, so that an undesired adjustment of the maximum distance and a corresponding risk of injury is avoided.

list of figures

• 1 shows schematically a sectional view of an embodiment of the workpiece clamp according to the invention.

Detailed description of preferred embodiments

Preferred embodiments of the invention are described in detail below with reference to the accompanying drawings.

A workpiece clamp 1 as a preferred embodiment of the invention is in 1 represented schematically in a sectional view. In the present embodiment, the workpiece clamp is used for clamping workpieces which at least in sections consist of wood, wood-based materials, plastic or the like, as are widely used in the field of furniture and structural elements. The workpiece clamp can be used for this purpose 1 are used in a processing device, not shown, in which case a plurality of workpiece clamps are usually provided. Such a machining device additionally has at least one machining unit for machining the workpieces and a conveyor unit for bringing about a relative movement between the at least one workpiece clamp and the machining unit.

The processing unit can be, for example, a cutting processing unit or a unit for coating the workpiece surface (for example with an edge material). The conveying unit can be, for example, a continuous conveying device in which the clamps are conveyed through the device in one pass direction during processing with the workpieces - if necessary clocked. Alternatively or additionally, the conveyor unit can also serve to move the processing unit to start processing the workpieces. Various combinations of these concepts are also possible.

As in 1 the workpiece clamp can be seen 1 a first, upper clamping element 2 and a second, lower clamping element 4 on, each a clamping surface 2 ' respectively. 4 ' exhibit. The clamping surfaces 2 ' . 4 ' serve to clamp a workpiece W. For this purpose, the first clamping element is in the present embodiment 2 between a clamping position and an opening position, as in 1 is shown, movable.

Alternatively, the second clamping element could also be used 4 be movable between a clamping position and an opening position. If necessary, both clamping elements 2 . 4 be moved.

For this purpose, the first clamping element 2 via a piston rod 6 connected to a drive, not shown, which can be, for example, a pneumatic or hydraulic actuator. The first tensioning element is by means of this actuator 2 between the in 1 shown opening position and a clamping position in which the workpiece W between the clamping surfaces 2 ' . 4 ' is stretched, movable.

In the area of the piston rod 6 points the workpiece clamp 1 a locking device 10 on that a maximum distance of the clamping surfaces 2 ' . 4 ' Are defined. In order to be able to adjust this distance if necessary, the locking device is 10 unlocked. In this unlocked state, for example, the upper clamping surface 2 can be raised or lowered by the maximum distance between the clamping surfaces without actuating the actuator 2 ' . 4 ' adapt. To set the maximum distance between the clamping surfaces 2 ' . 4 ' To facilitate, is in the present version on the piston rod 6 a scale 6 ' intended.

Although in 1 not shown, the locking device 10 have different non-positive and / or positive elements, which are in the unlocked state of the locking device 10 an adjustment of the maximum distance between the clamping surfaces 2 ' . 4 ' allow, in the locked state, however, ensure a reliable locking of the maximum distance.

To prevent unwanted unlocking of the locking device 10 the workpiece clamp has to prevent 1 also a safety device 20 on, which in the present embodiment is a rod-shaped securing element 22 and a substantially disk-shaped actuator 24 has by a screw 26 are interconnected. The actuator 24 has (imaginary) load application points on its outer circumference 28 for an operator. The go to the load application points 28 extending radius R of the actuator 24 is ten times larger than the radius in the present embodiment r of the securing element 22 , Thanks to these lever ratios, the actuating element can be operated without tools, ie an operator can manually rotate around the longitudinal axis of the securing element 22 apply in order to actuate the safety device in this way, ultimately to the locking device 10 to unlock or lock. This process can be done, for example, simply by rotating the actuating element 24 respectively. Alternatively, it is also possible that a two-stage actuation is provided, in which by rotating the actuating element 24 first the securing element 22 is then released by pressing or pulling (along the longitudinal axis of the securing element 22 ) the locking device 10 to unlock or lock. With this unlocking, as already mentioned, the maximum distance between the clamping surfaces can, if required 2 ' . 4 ' be adjusted.

The operation of the workpiece clamp 1 It then takes place as follows, for example. If the workpieces to be clamped are changed, the thickness of the workpieces to be clamped must first be determined, for example by measuring the workpiece thickness or by reading the workpiece thickness from a table, a display of the machine or the like. On this basis, it is checked whether the maximum distance between the clamping surfaces 2 ' . 4 ' the workpiece thickness plus a maximum gap dimension, which can be, for example, 5 mm. If this is the case, the maximum distance between the clamping surfaces 2 ' . 4 ' reduced.

For this purpose, the actuator is first 24 about the longitudinal axis of the securing element 29 rotated to the fuse element 22 release. Then the actuator 24 along the longitudinal axis of the securing element 22 depressed so that the securing element 22 performs a lifting movement. Through this lifting movement, the locking device 10 unlocked, so that now the maximum distance between the clamping surfaces 2 ' . 4 ' can be customized. Then the locking device 10 locked again, for example by an opposite rotational movement of the actuating element 22 , Now the desired workpiece can be in the area between the clamping surfaces 2 ' . 4 ' be inserted. Then the workpiece W can be tensioned by the actuator the upper tensioning element 2 lowered and a clamping force on the workpiece W applies.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102014216638 A1 [0002]

Claims (13)

Workpiece clamp (1) for clamping workpieces, which preferably consist at least in sections of wood, wood materials, plastic or the like, comprising: a first clamping element (2) and a second clamping element (4), each of which has a clamping surface (2 ', 4') to clamp a workpiece between the clamping surfaces, the first and second clamping elements (2 ', 4') being movable relative to each other between a clamping position and an opening position, and a locking device (10) which detects the maximum distance between the clamping surfaces ( 2 ', 4'), the locking device (10) being unlockable in order to set the maximum distance between the clamping surfaces (2 ', 4'), characterized in that the workpiece clamp has a securing device (20) which is set up a to prevent unwanted unlocking of the locking device (10). Workpiece clamp after Claim 1 , characterized in that the securing device (20) has a securing element (22) which can be fixed in a securing position in which an undesired unlocking of the locking device (10) is prevented. Workpiece clamp after Claim 2 , characterized in that the securing device (20) has an actuating element (24) which is set up to fix the securing element (22) in the securing position. Workpiece clamp after Claim 3 , characterized in that the actuating element (24) can be operated without tools. Workpiece clamp after Claim 3 or 4 , characterized in that the actuating element (24) has at least one load application point (28) for an operator, the lever arm of which is at least 10 times larger than a lever arm, in particular radius, of the securing element (22). Work clamp according to one of the Claims 3 to 5 , characterized in that the actuating element (24) has a disc and / or a lever in order to provide the at least one load application point (28). Work clamp according to one of the Claims 2 to 6 , characterized in that the securing element (22) is set up to unlock the locking device (10) by a lifting movement as soon as it is released by the actuating element (24). Workpiece clamp after Claim 7 , characterized in that the actuating element (24) is arranged to cause a lifting movement of the securing element (22) when actuated by a user. Workpiece clamp according to one of the preceding claims, characterized in that it has a scale (6 ') to facilitate the setting of the maximum distance between the clamping surfaces (2', 4 '). Workpiece clamp according to one of the preceding claims, characterized in that it has an actuator which is set up to move at least one clamping element (2, 4) between the open position and the clamping position. Device for machining workpieces, which preferably consist at least in sections of wood, wood-based materials, plastic or the like, comprising: at least one workpiece clamp according to one of the preceding claims, a processing unit for processing the workpieces, and a conveyor unit for bringing about a relative movement between the at least one workpiece clamp and the processing unit. Method for clamping a workpiece using a workpiece clamp according to one of the Claims 1 to 10 , with the steps: Define a workpiece to be clamped and determine the workpiece thickness to be clamped, check whether the maximum distance between the clamping surfaces (2 ', 4') exceeds the workpiece thickness plus a maximum gap dimension, reduce the maximum distance between the clamping surfaces (2 ', 4 ') if this exceeds the workpiece thickness plus a maximum gap dimension. Procedure according to Claim 12 , characterized in that the following steps are carried out in order to reduce the maximum distance between the clamping surfaces (2 ', 4'): unlocking the locking device (10) by means of the securing device (20), reducing and adjusting the maximum distance between the clamping surfaces (2 ', 4 '), Locking the locking device (10) by means of the securing device (20).

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