EP2998068B1 - Center tensioner with fast change jaws - Google Patents

Description

The present invention relates to a center tensioner with quick change jaws.

In order to hold workpieces safely and precisely and to be able to machine, for example, in machine tools, machining centers, 5-axis milling or drilling machines, machine vices are usually used, which can also have a power transmission. These machine vices also include centering or centering vise, in which two clamping jaws are guided by means of a spindle in a common base body and are centrally movable toward or away from each other. To be able to adapt such a center tensioner quickly to different sized workpieces, his jaws are often interchangeable, in particular rotatable.

For example, the DE 10 2010 047 380 B3 a linear mechanical quick release lock for locking and unlocking compatible clamping devices, where the jaw consists of a base and a top. The lower part has at least two, on a plane in one axis, transversely to the clamping direction, successively and sublime molded locking elements in dovetail shape, which serve for connection to the upper part. This has on a side facing the lower part of two correspondingly shaped and arranged recesses which are either open ended on one end side of the upper part or in a locking element larger insertion opening, so that the upper part placed flat on the lower part and by linear displacement locking means and recess in Intervention can be brought together. A releasing displacement is prevented by a blocking means pivotable in front of the upper part.

It is also known to provide a longer-lasting jaw lower part at its upper side with a plurality of mutually parallel and transversely to the direction of movement of the clamping jaw extending (dovetail) grooves and provided on the underside of a shorter jaw upper part correspondingly shaped webs, so that the jaw tops by a linear movement laterally in the grooves can be inserted and locked there by means of a laterally accessible Allen screw. A disadvantage of this is in particular the susceptibility to chip of the unoccupied grooves, which therefore must be laboriously protected against damage.

It is also known to provide a clamping jaw upper part (interchangeable insert) on a clamping jaw lower part (carrier jaw), which is lockably guided pivotably on the clamping jaw lower part and which can be removed upwardly out of the carrier jaw. For this purpose, the interchangeable insert on its side facing the support jaw two lugs which engage in corresponding recesses of the support jaw and on which the pivot axis is formed by a pressure pin passing through them.

The DE 20 2004 004 636 U discloses a center tensioner, according to the preamble of claim 1, comprising a base body and two clamping carriages arranged thereon, one arranged on the base body and acting on the clamping slide adjusting device is provided and the clamping slide under handle, which arranged on the base body, and this superior guide bar embrace.

A disadvantage of these known solutions is that they require a rather complicated construction of the clamping jaws.

The present invention therefore has the task of specifying a structurally simple and pollution-prone quick change clamping jaws.

This object is achieved in a center tensioner comprising a base body, two quick change jaws arranged thereon and an adjustment device acting on the base body and acting on the quick change jaws, the base body having on its upper side facing the quick change jaws a cross-sectional area than on its underside opposite it and each one Quick change jaws has a wrap around for this area, achieved by providing a releasable locking device for direct or indirect locking of the quick change jaws on the adjustment, wherein the locking device is formed by a through hole in the quick change jaws, a passing through this pin with manipulation means and engaging end and an engagement end on the adjusting device, wherein engaging and engaging ends are positively and / or positively engaged with each other. Such a locking device ensures the operability of the device by allowing it to safely initiate the clamping forces on the jaws in the body.

In contrast to the known technical solutions, a one-piece clamping jaws can be given with great advantage, eliminating the susceptibility to fouling two- or multi-part jaws, as well as the construction is simplified. Umgriff and corresponding Umgreifbereich represent a secure connection that is free from tilting moments of any kind.

Umgriff and quick change jaws are integrally formed, alternatively hinged together. Here, the first variant is preferred because it can be dispensed with a joint and its protection against unwanted opening.

In an embodiment of the invention it is provided that the region is formed as two opposing and mutually pioneering webs, wherein the webs are extending in the longitudinal direction of the center tensioner. These webs are inventively formed on the side walls of the body, spaced or not to the top. The webs may be continuous or longitudinally formed single or multiple interrupted. According to the invention, its cross-sectional area is approximately square or rectangular or polygonal or rounded, preferably a substantially square cross-sectional area with a radius in the transition of the sides. The webs may be formed according to the invention in particular hardened, preferably they are made of the same material as the body.

By the measure that the enclosures of the quick-change jaws are frontally open, so that the quick-change jaws in the longitudinal direction of the center tensioner can be pushed or removed from this, an extremely easy handling of the device is ensured with great advantage: The quick change jaws can easily by an operator to the rear, or be deducted from the front of the body or postponed. This allows the operator to replace one quick-change jaw with another with a handle in just a few seconds and quickly restore the operational capability of the center tensioner.

Another advantage is the embodiment, according to which the base body has a closed surface between the two quick-change jaws to their largest spacing from each other. Thus, the penetration of chips, dust or coolant / lubricant is prevented in the region of the adjusting device, the tensioner according to the invention is particularly long without cleaning used.

It is preferably provided that the webs are formed with their top side in alignment with the surface of the base body. As a result, a simplest construction is achieved while maximizing the width of a bearing surface of the quick-change jaws on the body.

Details of this embodiment are explained in more detail in the following description of the figures, which describes the invention in a preferred embodiment with reference to a drawing by way of example and further advantageous details in the figures of the drawing. Functionally identical parts are provided with the same reference numerals.

• Fig. 1: zeigt eine perspektivische Ansicht der Erfindung,
• Fig. 2: zeigt einen Querschnitt entlang der Linie A-A aus Fig. 1,
• Fig. 3: zeigt einen Längsschnitt entlang der Linie B-B aus Fig. 1 und
• Fig. 4 zeigt ein Detail der Arretiervorrichtung.

The figures of the drawing show in detail:

• Fig. 1 : shows a perspective view of the invention,
• Fig. 2 : shows a cross section along the line AA Fig. 1 .
• Fig. 3 : shows a longitudinal section along the line BB Fig. 1 and
• Fig. 4 shows a detail of the locking device.

Fig. 1 shows a perspective view of an embodiment of the invention Zentrierspanners 1 with main body 2 and two quick-change jaws 3. The main body 2 is received in a plate 17, as they are for automated workpiece change in the Serial production is needed. The base body 2 shows on its visible front side a cover plate 18, interspersed by a drive connection 19 for the invisible, inside the body protected adjustment device arranged 4. The quick change jaws 3 have in this embodiment, a two-stage surface with a first workpiece support surface 20 and one of these superior Stop 21 on. On the visible front side of the front quick-change jaw 3 whose open to the front end Umgriff 8 is shown, which surrounds a web 9, which in turn is integrally formed on the base body 2 and terminates with the surface 5. On the in Fig. 1 shown behind quick change jaws 3 is visible from the outside visible part of the locking device 11. This has manipulation means 14, here a hexagon socket. These manipulation means 14 are formed at one end of a pin 13, which passes through the quick-change jaws 3 to the adjusting device. The quick-change jaws 3 can be easily removed from the main body in the longitudinal direction of the device, or defer, as soon as the locking device has been solved. Thereafter, an exchange can be made against differently shaped quick-change jaws. According to the invention, the original quick-change jaws 3 rotated by 180 ° can be postponed again, so that there are different clamping options with the same quick-change jaws.

Fig. 2 shows a cross section along the line AA Fig. 1 , so that the locking device 11 is clearly visible, which consists of several parts. The main body 2 has two webs pointing away from each other 9, which are integrally formed on the upper side 5 and integrally formed with the base body 2. Their cross-sectional area is approximately square or slightly rectangular, namely higher than wide. These webs 9 are each encompassed by a wrap-around 8 of the quick-change jaw 3. The edges of the webs 9 have either a radius 22 or a chamfer 22, each in particular facilitate the removal and postponement of the quick-change jaws 3 on the body 2, but also improve their gliding. Webs 9 and body 2 are made in one piece from the same material. Inside the main body 2, the adjusting device 4 is arranged protected from environmental influences. The adjusting device 4 is in Fig. 3 shown clearly, at her the quick-change jaws 3 are locked. The locking device 11 used for this purpose has a through hole 12 which passes through the quick-change jaws 3 laterally to its center region. In this through hole 12, a pin 13 is sealed, which has a manipulation means 14 at one end, here a hexagon socket. Its opposite second end is formed as an engagement 15, here as a cone. Pin 13 and through hole 12 have corresponding threads. The engaging end 15 engages upon rotation of the pin 13 in an engaging end 16, which is designed here as a tapered bore in a locking block 25. The locking block 25 is clamped in this embodiment by means of a spring, not shown, against the quick change jaws 3 and thus leads to its operative connection with the spindle 23 of the adjusting device 4. From the illustrated working position of the center tensioner 1, the jaw change is made possible by the fact that the pin 13 is screwed , so that its engaging 15 passes deeper into the tapered bore of the engagement end 16 and thereby lifts the locking block 25 up against the spring force of the adjusting device 4. Once the locking block 25 is disengaged, that is sufficiently raised, the quick-change jaws 3 is removable from the body, together with the locking block secured to it 25. According to the invention would be if the pin 13 is manually operated by pressing in the direction of the center region , In this case, the manipulation means 14 would be according to an operator's finger formed troughs or the like. The pressing would take place against a counterforce, for example a spring.

Fig. 3 shows a longitudinal section along the line BB Fig. 1 and thus the internal structure of the adjusting device 4. This is taken up lengthwise in the base body 2 and closed at their end faces to the outside in each case by a cover plate 18. The spindle 23 acts via corresponding threads on a carriage 24 which has grooves 26 on its upper side into which a web 27 of the locking block 25 is engaged. In the illustrated working position, the quick change jaws 3 are moved by rotation of the spindle 23 relative to each other. The locking block 25 can be raised by means of the pin 13 until its web 27 comes out of engagement with the groove 26. For this purpose, the quick-change jaws 3 have a correspondingly large recess in its interior. The quick change jaws 3 can then either be withdrawn and exchanged for another or be moved to engage in one of the other grooves 26, so that can be easily adjusted in stages with the centering clamp achievable maximum clamping spans. Shown here are three stages (three grooves), but according to the invention, fewer or more stages may be provided.

It can also be seen well that the area between the quick-change jaws 3 is formed by a closed surface 10, which closes the interior of the clamping device to the outside and thus allows a high susceptibility to soiling. Even in the illustrated maximum span of the device, the surface is closed. Since the locking device 11 is arranged inside, the penetration of dust, dirt or coolant lubricants is virtually eliminated, the device is very safe.

Fig. 4 shows an inventive alternative to the described combination of pin 13 with taper and conical bore in the locking block 25. Shown is a pin 13 with an engagement end 15 which is formed in the manner of a worm gear. In this case, it would be possible to dispense with a spring force, provided that it is ensured that the pin 13 can not come loose unintentionally. Quite generally, according to the invention, any assembly can be used that enables axial-radial displacement conversion and whose final states can be locked. For better clarity contains Fig. 4 two rotational states of the pin 13, namely a raised and a lowered state of the locking block 25th

The invention allows with great advantage a rapid adjustment of the span of the Zentrierspanners with only one handle, namely, for example, only a quarter turn on the pin 13 with the one and the position changing the so dissolved Quick change jaw 3 with the other hand in a few seconds.

LIST OF REFERENCE NUMBERS

1

centering vise

2

body

3

Quick change jaws

4

adjustment

5

top

8th

throwing

9

web

10

surface

11

locking device

12

Through Hole

13

pen

14

manipulation means

15

engaging

16

engaging end

17

plate

18

cover

19

drive connection

20

Workpiece support surface

21

attack

22

Radius, chamfer

23

spindle

24

carriage

25

locking block

26

groove

27

web

Claims (7)

1. A centre clamp (1), comprising a main body (2), two fast change jaws (3) arranged thereon and an adjustment device (4) arranged on the main body and acting on the fast change jaws (3), wherein the main body (2) has, on its upper side (5) facing towards the fast change jaws (3), a cross-sectional region larger than on its underside arranged opposite, and wherein each fast change jaw (3) has a wrap-around means (8) for this region, characterised in that a releasable locking device (11) for directly or indirectly locking the fast change jaws (3) is provided on the adjustment device (4), wherein the locking device (11) is formed by a through-bore (12) in the fast change jaw (3), a pin (13) passing therethrough and comprising manipulation means (14) and an engagement end (15), and an engagement end (16) on the adjustment device (4), wherein the engagement end (15) and engagement end (16) are engaged with one another interlockingly and/or frictionally.
2. The centre clamp (1) according to claim 1, characterised in that the wrap-around means (8) and fast change jaws (3) are formed in one piece.
3. The centre clamp (1) according to claim 1, characterised in that the wrap-around means (8) and fast change jaws (3) are connected to one another in a hinged manner.
4. The centre clamp (1) according to claim 1 or 2, characterised in that the region is formed as two mutually opposed ribs (9) pointing away from one another and extending in the longitudinal direction of the centre clamp (1).
5. The centre clamp (1) according to any one of the preceding claims, characterised in that the wrap-around means (8) of the fast change jaws (3) are open at the ends, such that the fast change jaws (3) can be slid onto the centre clamp (1) or removed therefrom in the longitudinal direction of the clamp.
6. The centre clamp (1) according to any one of the preceding claims, characterised in that the main body (2) has a closed surface (10) between the two fast change jaws (3), as far as the greatest deflection of said jaws from one another.
7. The centre clamp (1) according to any one of the preceding claims, characterised in that the ribs (9) are formed such that their upper side is flush with the surface (10) of the main body.

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