WO2014170308A1

WO2014170308A1 - Clamp

Info

Publication number: WO2014170308A1
Application number: PCT/EP2014/057590
Authority: WO
Inventors: Rüdiger Schenke
Original assignee: Rüdiger Schenke
Priority date: 2013-04-18
Filing date: 2014-04-15
Publication date: 2014-10-23
Also published as: DE102013103913B4; DE102013103913A1

Abstract

The invention relates to a clamping device having a base plate (6), at least two clamping blocks (1, 2), a spindle (3) arranged therebetween in the upper region of the clamping blocks (1, 2) for introducing a clamping force, support plates (4, 5) for spacing a work piece from the base plate (6), wherein a support plate (4, 5), which movably contacts the clamping block above the spindle (3), is associated with every clamping block (1, 2), wherein every clamping block (1, 2) is designed to introduce the clamping force into the support plate (4, 5) associated therewith, wherein the support plates (4, 5) together with the associated support blocks (1, 2) are connected to each other in an articulated manner in the region of the base plate (6) and form a pull-down element (7), characterized in that the centres of gravity of the support plates (4, 5) in the operating state of the clamping device are further away from each other than the work piece support surfaces (8) of the support plates (4, 5).

Description

Stretcher

The present invention relates to a clamping device, as it is known in principle from DE 10 2008 013 643 A1.

Such a clamping device has at least two clamping blocks and a spindle arranged in the upper region of the clamping blocks

Introduction of a clamping force and support plates for spacing a workpiece from a machine table or a base plate, wherein a clamping block and an associated support plate adjacent to each other above a tensioned workpiece and a

Sliding movement to each other are possible.

Due to the position of the spindle at any height above a base plate of the clamping device or a machine table and immediately below the clamped workpiece, high clamping forces can be introduced into the workpiece without bending the base plates or the machine table on which the device is mounted.

When applying clamping forces from 30kN, workpieces tend to be lifted away from the clamping floor up to several hundredths of a millimeter. This stroke movement during the introduction of the clamping force is caused by the smallest misalignment of the jaw parallel

Side edges of the workpiece, allowing the clamping force too

different contact forces on the jaws and thus leads to a considerable torque and tilting. It is further caused by the distance between the parallel planes of spindle and workpiece clamping. This results in a resultant force that results in the lifting of the workpiece.

The well-known from the prior art mounting workpieces on support plates makes it possible, especially in their workpieces

Tensioning in a precisely defined position, so that the usually very tight manufacturing tolerances are met. This is especially true in a series production, in which a plurality of identical workpieces are clamped one behind the other, without each time an additional check can be made. A clamping block initiates the clamping force in its associated support plate and has a relative to this relatively movable contact area, so slides on this. This means that the clamping force over two does not match

connected components is introduced into the workpiece, so that occurring lifting forces within the clamping device and not between the clamping device and the workpiece can be derived by the clamping block slides on its associated support plate. This prevents that the support plates bend, setting up the workpieces when applying the clamping force is prevented.

A disadvantage of this prior art, the user often perceived as not easy handling and the tendency not completely derive the resulting forces.

The present invention therefore has as its object, a functionally at least equivalent, but easier to use

Specify clamping device. This object is achieved with a clamping device, comprising a

Base plate, at least two clamping blocks, one arranged in the upper region of the clamping blocks between them spindle for introducing a clamping force, support plates for spacing a workpiece from the base plate, each clamping block is associated with a support plate, the clamping block above the spindle is slidably contacting, each Clamping block, the clamping force is formed in the associated with him support plate preliminarily, wherein the articulated with their associated clamping blocks in the base plate connected to each other and forming a Niederzugelement, solved by the fact that the centers of gravity of the support plates in the operating state of the clamping device are further apart than the

Workpiece bearing surfaces of the support plates from each other. In contrast to the known prior art, in which the support plates, the clamped workpiece and the spindle formed a parallelogram, which is basically bending or verkippungsanfällig, the embodiment of the invention leads to an approximately trapezoidal structure, ie to a structure with wider Base and narrower upper ground. The broad base of the trapezoid is formed by the foot of the support plates, or the imaginary line connecting their centers of gravity, or the projected emphasis on the base plate, the narrow upper base of the trapezoid through the imaginary line connecting the two workpiece support surfaces of the support plates, or in the ready-to-use state of the device also by the workpiece clamped between the support plates. In this case, both the beginning and the middle or end points of the horizontal support surface can be used as a reference point for the upper base side. Such a trapezoidal structure is much more stable than that of a parallelogram, as it results in relatively narrow platen, since a tilting of the trapezoid is always associated with a change in length of the bases and thus significantly more difficult. The invention retains the advantageous separation of support plate and clamping block, wherein the clamping block does not touch the workpiece but rather can slide on the former and thereby avoids a placement of the workpiece. This effect is particularly enhanced by the fact that the two clamping blocks are both movable and strictly symmetrical to each other. As a result, the forces always occur symmetrically in the workpiece clamping in two clamping blocks, so that they are far predominantly neutralize and do not lead to a change in position of the workpiece relative to the base plate or to a lying outside the device reference point. The positional accuracy thus achieved leads to a particularly dimensionally stable, and unaffected by the jig machining of the workpiece.

In an embodiment of this principle, the invention proposes that

Platen one basically decreasing in the direction of the spindle and the associated clamping blocks have a basically increasing in this direction course of their respective lying on a common plane horizontal diameter. The described

Change according to the invention, however, is not necessarily continuous, rather the respective diameter may also remain constant or decrease or increase in opposite directions as long as the foot region of the

Platen a much larger diameter than their

Has workpiece support area. The approximately inverse course of the horizontal diameter of both components of a tensioner leads with great advantage to the fact that the foot area is particularly stable due to the very thick support plate here and the center of gravity significantly influenced. At the same time, therefore, the clamping block is designed to be particularly thick in the spindle and thus provides sufficient material thickness for their attachment available.

According to the invention it is further provided that the support plates in each case by means of a connecting means with their associated

Clamping blocks are formed movably connected. This

Connecting means advantageously does not lead to a rigid connection that would prevent sliding of the two components relative to each other, but rather to a bias between the two parts, so as to allow sliding only after exceeding a predetermined force and at the same time the joint adjustability of the two otherwise allow separate components. As a result, the device is easy to use despite the rather complicated construction of a tensioner page.

In development of the invention it is provided that the support plates have quick adjustment, in particular screw-nut combinations. As a result, while still adequately fixing the clamping block-pad combination on the base plate a quick adjustability achieved by the screw simply solved briefly on the nut side, the combination of both components moved together on the base plate and the mother are tightened again. The screw is inventively preferably held positively in the support plate to have only one moving part - the mother. As a result, the support plate must have only a smooth-walled through hole, which is easy to manufacture and is difficult to damage during operation by chips or other influences.

Is there a support plate of at least two horizontally separate and releasably interconnected components, an easy-to-use adaptability of the support plate is with great advantage

achieved different workpieces. The larger lower component of the support plate always remains the same, on it can as needed

differently shaped upper components are attached to support so different workpieces by means of, for example, pins, rubber plates, or other mounts. As a result, the flexibility of the device is increased, the adaptation of the holder to differently-type workpieces can be easily achieved by changing only a part of the support plate.

In a further embodiment of the invention is provided, the

Pull-down element at the same time a centering element for its clamping block is and is formed by a wedge element, a variable recess and a clamping portion on the base plate, which is clamped by the variable recess. According to the invention, the centering of the clamping block support plate unit to the base plate, wherein for this purpose a portion of the base plate between two relatively movable parts is clamped and wherein the relative movement of the two parts in a preferred embodiment by an action of a clamping block portion on a

Platen section is successful. In this embodiment, the clamping portion of the base plate is located in the central region along the longitudinal axis and is configured in cross-section approximately trapezoidal. On the right and left of it there are at least one wedge element, arranged on the clamping block, which press into the respectively associated expandable recess, arranged in the support plate, so that the widened wall of the recess against the

Press the clamping section and pull the support plate down onto the base plate and center it. Of course, the arrangement of wedge element and recess could also be reversed.

Finally, the invention provides that the area between the support plates and clamping block is covered by a cover to the environment. As a result, the penetration of chips and possibly inserted lubricating coolant in the gap between

Support plate and clamping block prevented.

Has at least one clamping block an oval passage opening, which is penetrated by a portion of the spindle, wherein the portion has a recess in which correspondingly shaped portions of retaining pins are engaging, wherein the retaining pins have at least one thread, in which a threaded piece is engaging and the retaining pins are enforcing the clamping block, so is with large Advantage of a very easy to handle and replaceable spindle

specified. In the prior art, the replacement of the spindle was cumbersome and difficult.

Thanks to the oval passage opening is for a user of

inventive clamping device sufficient space to use the spindle in the clamping block can. In this case, the spindle has a recess, in particular a passage opening, into which laterally correspondingly shaped sections of retaining pins engage. The retaining pins are in turn thanks to a thread and a correspondingly shaped and engaging in the thread

Threaded piece helically in the direction of the recess or in the opposite direction movable. To change the clamping width when changing a workpiece type, the spindle according to the invention is shortened by removing a spindle segment or extended by adding a spindle segment. For this purpose, a retaining pin is released on one side, whereby the spindle is removable from the other retaining pin, which is made possible thanks to the large diameter oval cross section of the through hole of the clamping block and the support plate. The length-matched spindle can then be pushed onto the remaining in the clamping block retaining pin and mounted by screwing in the second retaining pin in the correct position and reliable supported.

The invention will now be with reference to the figures to a

Embodiment explained in more detail, wherein the same reference numerals designate the same components. 1 shows a side view of a device according to the invention,

2 shows a partially sectioned plan view of an embodiment according to the invention, 3 shows a front view of an embodiment according to the invention,

Fig. 4 is a side view of the same embodiment with transparent lines and

Fig. 5: a front view with transparent lines.

Fig. 1 shows a clamping device according to the invention in side view. On a base plate 6 are two movable clamping blocks 1, 2

arranged, each associated with a support plate 4, 5. A spindle 3 penetrates with its ends in each case a support plate 4, 5 and a clamping block 1, 2 and is supported in the latter. Between clamping block and support plate per cover 15 is releasably attached. This is omitted on the right side of Fig. 1. There is good to recognize the approximately inverse course of the horizontal diameter of support plate 4 and clamping block 1, which complement each other at least in the lower area to a constant overall diameter, the invention depends particularly on the different horizontal position of the center of gravity and center of the support surface, what in this embodiment by a particularly wide foot of the

Platen is achieved at a rather narrow diameter in the support area for the workpiece. Platen 4, 5 and clamping block 1, 2 are connected by means of a connecting means 9 (see FIGS. 4 and 5) approximately in the vertical center with each other movably. The connecting means 9 is a screw 22, which, however, does not connect the two parts firmly together, that is not fully tightened. It should only give a certain bias to the two components and is secured for this purpose with a locking pin 26 against its detachment. The clamping block 1 is located at its upper end slidably on the

Platen 4, so that it is about one hundredths of its location can change relative to the support plate 4. The upper part 4b of

Platen 4 is fixed with a screw 27 per side on the lower, thicker part 4a of the support plate 4. In the foot region of the support plate 4, a quick adjustment device 10 can be seen. This is formed by a screw-nut combination 1 1, which are clamped between two separate by an air gap sections of the support plate. Loosening the nut with screw head guided in a form-fitting manner in a slot causes the support plate to be displaced on the base plate 6 together with the clamping block held by the connecting means 9. This applies equally to both clamping blocks.

FIG. 2 shows a partially sectioned plan view of the embodiment of FIG. 1. FIG. In the cut part of Fig. 2 is the Niederzug- and

Centering element 7 shown. The pull-down and centering element 7 is formed by a wedge element 12 on the clamping block 1 and a

variable recess 13 in the support plate, as well as an integrally formed on the support plate corresponding to the wedge element 12 obliquely shaped wall portion. The wedge member 12 presses when tightening the spindle 3 with its slope 12 against the corresponding obliquely shaped wall in the support plate. Since the recess 13 is oriented centrally and coaxially to the longitudinal axis of the base plate 6 and two to the longitudinal axis of the base plate 6 symmetrically arranged wedge elements 12 per

Clamping block are provided, the recess 13 is symmetrically narrowed by this, as soon as the screw-nut combination 1 1 is tightened. The clamping block support plate unit is thereby centered on the base plate 6 and pulled down, since the two parts of the support plate next to the recess 13 between them

Clamping portion 14 (see Fig. 3) clamp. Fig. 4 shows a side view of the same embodiment with

transparent lines, in particular the position of connecting means 9 between the support plate and clamping block with locking pin 26th

play. In the area of the spindle 3, the two setscrews 16 with their threads 20 are clearly visible, in each case one

Threaded piece 21 is engaging (see also Fig. 5). The setscrews 16 have smaller diameter portions 18 which engage in correspondingly shaped recesses 17 of the spindle 3 and hold them in a form-fitting manner. In other words, the

smaller diameter portions 18 of the two opposing threaded pins 16 a tensioner side toward each other. The sections 18 are preferably cylindrical, the recess 17 is a corresponding to the sections 18 sized passage opening, as well as Fig. 5 can be seen. Although four or four

Hexagonal recesses and sections conceivable, but these are more difficult to manufacture and therefore rather disadvantageous. Fig. 4 also shows connecting means 25 between the parts 4a and 4b of the support plate 4, which are formed as screws 27. The segment-like structure of the spindle 3 can also be clearly recognized. By choosing different lengths or by joining several segments together, different spindle lengths can be generated, thus clamping workpieces of different lengths. Advantageously, one of the two attachment ends of the spindle 3 in the clamping block remain, for example, the left in Fig. 4. To change the spindle length is a threaded pin 16 on the other side tensioner to solve and remove from the block. As a result, the spindle end is free and can be used in the slot and brought out of engagement with the other threaded pin 16 of this tensioner side. After extension or

Shortening of the spindle 3, the attachment end in the slot transverse to the longitudinal axis of the device over the whole or at least partially pushed into this oval slot projecting threaded pin 16 so that the spindle can be quickly placed correctly. After the spindle 3 has been placed easily and quickly, the second set screw 16 quickly becomes due to its high pitch thread

Attachment of the spindle 3 screwed. A change is therefore fast, reliable and under constant visual and tactile control of the operator.

Fig. 5 finally shows the front view with transparent lines. Good to see is the attachment of the spindle 3 by means of the threaded pins 16 in the oval passage opening 28. The previously described simplicity of Spindelösens, shortening or -verlängerns and re-inserting are even easier to understand in this view of the invention. FIG. 5 also illustrates the pull-down and centering element 7.

reference numeral

clamping block

spindle

platen

baseplate

Pull-down and centering element

Workpiece support surface

connecting means

Schnellverstellvorrichtung

Screw-nut combination

key member

Changeable recess

clamping section

cover

Set screw

recess

section

retaining pin

thread

threaded piece

screw Hexagon bolt Lanyard Locking pin

screw

Oval passage opening

Claims

claims

Clamping device, comprising a base plate (6), at least two clamping blocks (1, 2), one in the upper region of the clamping blocks (1, 2) arranged therebetween spindle (3) for introducing a clamping force, support plates (4, 5) for spacing a

Workpiece of the base plate (6), wherein each clamping block (1, 2) is associated with a support plate (4, 5), the clamping block above the spindle (3) is slidably contacting, each

Clamping block (1, 2) the clamping force in his assigned

Support plate (4, 5) is formed initially, the

Support plates (4, 5) with their associated clamping blocks (1, 2) in the region of the base plate (6) hingedly connected to each other and forming a Niederzugelement (7), characterized

characterized in that the centers of gravity of the support plates (4, 5) in the operating state of the clamping device are further apart than the workpiece support surfaces (8) of the support plates (4, 5) from each other.

Clamping device according to claim 1, characterized in that the support plates (4, 5) in the direction of the spindle (3) basically decreasing and the associated clamping blocks (1, 2) in this direction basically increasing course of their respective lying on a common plane have horizontal diameter.

Clamping device according to claim 1 or 2, characterized

characterized in that the support plates (4, 5) are each connected by means of a connecting means (9) with their associated clamping blocks (1, 2) movably connected. Clamping device according to claim 1, 2 or 3, characterized

characterized in that the support plates (4, 5)

Have quick adjustment devices (10), in particular

Screw-nut combinations (1 1).

Clamping device according to claim 1 or 2, characterized

characterized in that a support plate (4) consists of at least two horizontally separate and releasably interconnected components (4a, 4b).

Clamping device according to claim 1, 2 or 3, characterized

characterized in that the pull-down element (7) is at the same time a centering element for its clamping block and is formed by a wedge element (12), a variable recess (13) and a clamping portion (14) on the base plate (6), which through the

Quick adjustment device in cooperation with the wedge element (12) and the variable recess (13) is clamped.

Clamping device according to one of the preceding claims, characterized in that the area between support plates (4, 5) and clamping block (1, 2) by means of a cover (15) is covered to the environment.

Clamping device according to one of the preceding claims, characterized in that at least one clamping block (1, 2) has an oval passage opening which is penetrated by a portion (16) of the spindle (3) and wherein section (16) has a recess (17) into the correspondingly shaped sections (18) of

Holding pins (19) are engaging, wherein the retaining pins (19)

have at least one thread (20), in the one

Threaded piece (21) is engaging and wherein the retaining pins (19) the clamping block (1, 2) are penetrating.