EP0854771B1 - Shaped clamping jaw for a clamping device - Google Patents

Abstract

The invention relates to a shaped clamping jaw for a clamping device with a clamping frame (12), a plurality of clamping rams (20, 20') arranged in parallel transversely to the plane of the frame and movable independently of one another and a clamping mechanism (26) pressing the clamping rams together inside the clamping frame (12). In order to ensure that the clamping rams (20, 20') are uniformly secured inside the clamping frame (12), the invention proposes that the clamping rams be stressed longitudinally and transversely inside the rectangular clamping frame by means of the clamping mechanism.

Description

The invention relates to a mold clamping jaw according to the preamble of claim 1.

Mold clamping jaws are components of clamping devices, such as in vices, machine tools or machining centers to hold on to of workpieces with contoured surfaces become. A mold clamping jaw of this type is known (US-A-2 754 708) in which the plunger is a Has hexagonal profile and honeycomb in the clamping frame are arranged so that they are transverse to the direction of displacement of the pressure piece and the tappet-running contact surfaces against each other. This will form between the pressure piece and the abutment piece in the direction of displacement the plunger individual plunger columns, that do not exert any transverse forces on the neighboring columns. There is therefore no transverse tension within of the clamping frame and therefore not a safe one Clearing effect. The tension plungers are there in their direction of displacement acted upon by a compression spring. The compression springs designed as a coil spring are on Guide tappets protruding rearward over the tensioning plungers attached and are supported on a frame fixed Support plate. The guide plungers reach through Openings in the support plate and wear its rear end strikes against the support plate Stop collar. With these measures one a relatively large length of the plunger and one correspondingly large depth of the clamping frame, the particularly disadvantageous for small and narrow clamping tasks impact. The end faces of the hexagon ram are spherical, so that a point contact on Workpiece.

A mold jaws with the contained in the preamble of claim 1 Characteristics is e.g. known from DE-C-107135.

The invention is based on the object to develop a mold jaw that has a reliable locking of all rams in the clamping frame enables.

To solve this problem is the in claim 1 specified combination of features proposed. Beneficial Refinements and developments of the invention result from the dependent claims.

The solution according to the invention is based on the idea that the plunger under the action of the pressure piece and the abutment piece also transversely to the direction of displacement against each other and against the parallel to Direction of movement aligned frame leg can be pressed are. To achieve this, according to the invention suggested that the feed movement of the Pressure piece over at an angle to the direction of displacement Thrust ram aligned contact surfaces is partially converted into a transverse movement that too a tension compared to that parallel to the direction of displacement aligned frame legs leads, wherein the plungers within the plunger assembly both in the direction of displacement and against the direction of displacement of the pressure piece converging like an arrow Have contact surfaces. This is been achieved with tension plungers, the one Hexagonal profile with in the direction of displacement and against the direction of displacement of the Have pressure point pointing profile tips.

To create the pressure piece and the abutment piece to improve against the tensioning plunger, the Pressure piece and / or the abutment piece facing Side faces of the rams flattened plane-parallel become.

The abutment piece can be fixed to the frame and through the frame leg opposite the pressure piece be formed. But it can also be used for Pressure piece in the opposite direction against the ram arrangement slidably arranged in the clamping frame be.

In order to securely jam everyone arranged in the clamping frame To reach the ram, it is advisable the clear width of the frame opening transverse to that in the direction of displacement of the pressure piece essentially parallel Frame legs in the course of these frame legs vary continuously or in stages. The light one Width can be from the movable pressure piece to the fixed one Remove the abutment piece or from the movable one Pressure piece and from the movable abutment piece from Remove the center of the frame. With these measures can be achieved be that of the movable plunger further removed ram before the pressure piece Tappets within the clamping frame be braced.

An automatic adaptation to a curved or stepped Workpiece surface is reached when the Tension rams spring-loaded in their feed direction are. To do this with the shortest possible length of the To reach the ram and the depth of the clamping frame, according to a preferred embodiment of the invention suggested that the tension plunger be a rear, axially central blind hole for receiving one a compression spring that supports the frame exhibit. The support surface can preferably by frame-fixed support plate parallel to the frame level be educated.

A preferred and particularly simple embodiment the invention provides that the compression spring as between the support surface and the ram clamped, clear the space between these two parts bridging helical compression spring is formed. For Improve the stability of such a pressure piece it may be beneficial if individual in the blind hole Tension ram protruding from the support surface penetrating the helical compression spring, preferably in the length of its protruding beyond the support surface Section adjustable stop and guide pin intervenes. The helical compression spring can with her end turns lying on block against each other a support surface and / or a ram side Threads are turned or in a support surface and / or ram-side recess fixed with an adhesive or screw connection become.

For special clamping tasks, where always the same, with a pronounced surface contour Workpieces are to be clamped, the ram path at Optimizing the contouring process has proven to be advantageous proven when the ram in their respect the outermost end position of the frame opening the surface contour of the workpieces to be clamped have an adapted length and / or end face contour.

Advantageously, one with her in the blind hole External surface an annulus for the as a helical compression spring trained compression spring limiting guide sleeve inserted into which a protruding over the support plate frame-fixed guide pin can engage. In order to the displacement of the ram can be relatively easy be limited if the guide sleeve by a end pipe retraction formed stop for one molded onto the free end of the guide pin Has stop collar. The guide pin is for that expediently designed as a headed bolt, in the Sleeve with head part engaging play the stop collar forms and its end opposite the head attached to the support plate, preferably glued, soldered or welded on.

Another advantageous embodiment of the invention provides that the ram with a rear Contact surface against the surface of a frame-fixed, elastic in the direction of displacement of the clamping plunger resilient cushion layer. For improvement the ram guide can the ram one projecting beyond its rear contact surface, engaging in a catch recess of the cushion layer Have anchoring spigot at its end expediently has a latching thickening.

An additional improvement in the holding effect of the Mold clamping jaws can be achieved in that the Tappet a ball socket open on the front Inclusion of a rotatable in the ball socket on your segment protruding outwards through the pan opening flattened ball to form the end face exhibit. To improve mobility and the cleaning option of the tensioning ball can be preferred leading axially from the blind hole to the ball socket, bore in the ram that can be pressurized with compressed air be provided.

To facilitate the handling of the mold clamping jaw it is advantageous if a device for common Retracting the ram into its inside the Clamping frame provided biased end position is provided is. The pull-in device can be mechanically pneumatically, hydraulically, electromagnetically operated become. In this context, it is advantageous if the guide bolts are on a common, opposite the clamping frame can be moved transversely to the displacement plane, forming part of the feeder Retraction plate are attached.

For large mold jaws with many rams it turned out to be advantageous if the pressure piece is designed as an elbow, which is parallel to Direction of movement aligned, on the adjacent frame leg has indirectly supported angle leg.

Fig. 1

eine Draufsicht auf einen Formspannbacken;

Fig. 2

eine Längsseitenansicht des Formspannbackens nach Fig. 1;

Fig. 3

eine Stirnseitenansicht zweier einander zugewandter Formspannbacken;

Fig. 4

einen vergrößerten Ausschnitt aus einem Formspannbacken in teilweise geschnittener Darstellung;

Fig. 5

eine Längsseitenansicht des Formspannbackens entsprechend Fig. 2 mit einer Einziehvorrichtung für die Spannstößel;

Fig. 6

einen vergrößerten Ausschnitt aus dem Formspannbacken nach Fig. 5 in teilweise geschnittener Darstellung;

Fig. 7

eine Längsseitenansicht eines abgewandelten Formspannbackens mit Polsterschicht in teilweise geschnittener Darstellung;

Fig. 8

eine Seitenansicht eines Spannstößels nach Fig. 7 in vergrößerter Darstellung;

Fig. 9

eine Seitenansicht eines federbelasteten Spannstößels in teilweise geschnittener schematischer Darstellung;

Fig. 9a

eine Seitenansicht eines gegenüber Fig. 9 abgewandelten Ausführungsbeispiels eines federbelasteten Spannstößels in teilweise geschnittener Darstellung;

Fig. 10

eine Draufsicht auf einen Formspannbacken mit winkelförmigem Druckstück;

Fig. 11a und b

eine Stirnseitenansicht und eine Breitseitenansicht zweier einander zugewandter Formspannbacken mit eingespanntem Werkstück;

Fig. 12

eine Stirnseitenansicht zweier einander zugewandter Formspannbacken mit spannflächenkonturierten Spannstößeln.

The invention is explained in more detail below with reference to an exemplary embodiment shown schematically in the drawing. Show it

Fig. 1

a plan view of a mold clamping jaw;

Fig. 2

a longitudinal side view of the mold clamping jaw according to Fig. 1;

Fig. 3

an end view of two mutually facing mold jaws;

Fig. 4

an enlarged section of a mold jaw in a partially sectioned representation;

Fig. 5

a longitudinal side view of the mold clamping jaw according to Figure 2 with a retraction device for the clamping plunger.

Fig. 6

an enlarged section of the mold jaw according to Figure 5 in a partially sectioned representation.

Fig. 7

a longitudinal side view of a modified mold jaw with cushion layer in a partially sectioned representation;

Fig. 8

a side view of a plunger according to Figure 7 in an enlarged view.

Fig. 9

a side view of a spring-loaded ram in a partially sectioned schematic representation;

Fig. 9a

a side view of a modified embodiment of Figure 9 of a spring-loaded plunger in a partially sectioned representation;

Fig. 10

a plan view of a mold jaw with an angular pressure piece;

11a and b

an end view and a broad side view of two mutually facing mold jaws with clamped workpiece;

Fig. 12

an end view of two mutually facing mold jaws with ram contoured ram.

The mold clamping jaw 10 shown in the drawing is part of a clamping device, such as in vices, machine tools or machining centers needed to hold workpieces become. The mold clamping jaw 10 contains one Clamping frame 12, the two opposite each other in pairs, a rectangular frame opening 14 delimiting short frame legs 16 ', 16' 'and long frame legs 18 ', 18' '. In the frame opening 14 the clamp frame 12 is a plurality of transverse to the frame plane aligned parallel and independent tensioning plungers 20, 20 'which are displaceable from one another provided that on their side surfaces 21 in denser Pack against each other and with their over the Frame opening 14 outwardly projecting free end faces 22 one on the surface contour of a workpiece Form 24 adjustable clamping surfaces. Within the Clamping frame 12 is also a plate-shaped Pressure piece 26 arranged with an operating lever 28 bearing, in a thread 30 of the short Frame leg 16 'guided threaded plunger 32 in the direction arrow 34 against the ram arrangement 20, 20 'is displaceable. In the embodiment shown forms the pressure piece 26 opposite short frame leg 16 '' an abutment for the ram assembly.

The clamping plunger 20 inside the clamping plunger arrangement have a hexagonal profile and are like a honeycomb arranged that two of their profile corners 36 in the manner of a Arrowhead in the direction of displacement 34 and counter are aligned with the direction of displacement. The the pressure piece 26 and the short, which acts as an abutment piece Frame leg 16 '' facing ram 20 ' are on the side of the pressure piece or the abutment piece flattened.

As can be seen from Fig. 4, the plungers 20, 20 'under the action of a compression spring 38 transverse to Frame level limited by the distance a in the clamping frame 12 slidable. For this purpose, the plungers have a rear stepped bore 40 into which a guide sleeve 42 is inserted on its outer surface limited an annular space 44 for receiving the compression spring 38 and in their central interior one into one Bore 46 of a frame-fixed support plate 48 glued in Head bolt 50 engages with its head part 52. The Guide sleeve 42 is drawn in at its free end and there forms a stop 55 for the head 52 of the Head bolt 50 in the extended end position of the Tappet 20. The compression spring is supported on her one end to the frame-fixed support plate 48 and its other end on a tappet-proof shoulder 54 within the stepped bore 40.

In the area of the end face 22, the tension plungers have 20, 20 'a ball socket 53 for receiving one around her Center point 56 rotatable clamping ball 58. On hers segment protruding from the opening of the ball socket 53 the clamping ball 58 has a flat, the end face 22 forming flattening. To improve the Movability of the clamping ball and for cleaning purposes is an axial bore 60 to which compressed air can be applied provided that from the stepped bore 40 in the ball socket 53 opens.

To adapt to the surface contour of a to be clamped Workpiece 24 are first the mold jaws 10 with the end faces 22 of the free in the clamping frame 12th against the force of the compression springs 38 slidable Plunger 20, 20 'guided against the workpiece surface. The plungers 20, 20 'adapt to the Surface contour of the workpiece 24 on (Fig. 2). In this position, the plungers 20, 20 'then by moving the pressure piece 26 over the actuating lever 28 and the threaded plunger 32 against the clamping plunger arrangement postponed. The ram assembly towards the abutment on the short frame leg 16 '' pressed. Initially, the rams 20 a cross game against the frame legs 18 ', 18' ' on what is the shift in the direction of arrow 34 only made possible. After hitting the abutment surface 16 '' is on the clamping plunger 20 over the inclined contact surfaces 21 in the manner of a wedge gear additionally exerted a transverse force that leads to a transverse displacement the plunger 20 and thus to one Cross bracing with the long frame legs 18 ', 18 '' leads. As can be seen from Fig. 1, the clear width of the frame opening transverse to the direction of displacement 34 of the pressure piece 26 in the course between Thrust piece 26 and abutment piece 16 '' from step. This ensures that the transverse tension of the Tappet 20 from the abutment end to the pressure piece side Towards the end and therefore an even one Clamping of all clamping rams is possible.

In the exemplary embodiments shown in FIGS. 11 and 12 the plungers 20, 20 'have a surface contour of a workpiece 24 to be clamped Length and / or end face contour, for example by turning, copy milling or eroding can be. So with special clamping tasks, always with the same workpieces a pronounced surface contour must, possible, the ram path during the adjustment process to minimize and a deformation-free clamping to ensure the workpieces.

In the embodiment shown in FIGS. 5 and 6 is a mechanical, pneumatic, hydraulic or Electromagnetically actuated pull-in device 71 provided with which the plunger 20, 20 'in their inside the prestressed end position of the frame are retractable. The retractor includes one Retraction plate 72 on which the guide pin 50 with an end plate 70 attached, preferably welded are. The retraction plate is opposite the frame Support plate with the tension plunger 20, 20 'against the force of the compression springs 38 Distance dimension a 'displaceable.

In the embodiment shown in FIGS. 7 and 8 a mold jaw is a frame-fixed one Padding layer 80 of elastomeric material, preferably made of silicone gel, provided against its surface 84 the clamping plungers 20, 20 'with their rear contact surface 83 concerns. The tension plungers also have one projecting beyond the rear contact surface 83, an anchoring pin having a thickening 81 85 on, with which they in a corresponding, open edge Engage the catch recess of the cushion layer 80.

In the embodiment shown in Fig. 9 are the plunger 20 with a helical compression spring 38 connected to the frame-fixed support plate 48. The helical compression spring is doing it with their on block against each other adjacent turns 39 on a support surface side and a rake face thread 41, 43 turned up and bridged with their free spring turns the space between the plunger 20 and the support plate 48 so that a lateral shift of the Tension ram is possible during the tensioning process. In the embodiment 9a, a stop and guide pin 49 is additionally provided, which with its the portion protruding from the support plate Coil spring 38 penetrates and into the rear Blind hole 40 of the plunger 20 engages. The stop and guide pin 49 engages through a threaded hole 59 of the support plate and is over the Hexagon socket 51 in the length of its over the support plate 48 protruding section adjustable and with a lock nut 57 can be fixed on the support plate 48. The helical compression spring 38 is there on Block opposing end turns 39 in recesses 45 ', 45' 'of the support plate 48 and the plunger 20 fixed for example by means of an adhesive.

In the embodiment shown in FIG. 10 the pressure piece 26 is formed as an elbow, which ever an angle leg parallel to the frame legs 16 'and 18' 91, 92 and by pins 90 transverse to the direction of displacement 34 against the frame leg 18 'is supported.

Claims (31)

1. A shaped clamping jaw for a clamping device comprising a clamping frame (12) which has two pairs of opposed frame legs (16', 16'', 18', 18'') delimiting an essentially rectangular frame opening (14), comprising a plurality of clamping rams (20, 20') which are disposed within the frame opening (14) of the clamping frame (12) and aligned parallel to each other and transversely with respect to the plane of the frame, and which are adapted to be moved independently of one another, lie against one another in a dense packing and form with their free front faces (22) which project over the frame opening (14) a clamping surface which is adapted to be matched to the surface contour of a workpiece (24), and comprising a clamping mechanism which presses the clamping rams against one another within the clamping frame (12), which clamping mechanism has a thrust piece (26) which is disposed within the frame opening (14) and which is adapted to be moved transversely with respect to the direction of movement of the clamping rams (20, 20') essentially parallel with respect to one pair of the frame legs (18', 18'') laterally against the clamping ram arrangement and an abutment piece (16'') which is opposed to the thrust piece in the direction of movement (34) thereof and lies against the clamping ram arrangement, wherein the clamping rams (20, 20') are adapted to be pressed transversely with respect to the direction of movement (34) against the frame legs (16', 16'') which are aligned parallel with respect to the direction of movement (34) under the action of the thrust piece (26) and the abutment piece (16'') by means of their contact surfaces which are oriented slanted with respect to the direction of movement (34) of the thrust piece (24), characterized in that the clamping rams (20) have a hexagonal profile with two profile corners (36) pointed in the direction of movement (34) and opposed to the direction of movement of the thrust piece (26) in the fashion of arrow tips, and that the clamping rams are arranged in a honeycomb manner within the clamping ram arrangement.
2. The shaped clamping jaw of claim 1, characterized in that the abutment piece is formed by the frame leg (16'') which is opposed to the thrust piece (26) in the direction of movement (34).
3. The shaped clamping jaw of claim 1, characterized in that the abutment piece is adapted to be moved against the clamping ram arrangement in a direction opposed to the direction of movement of the thrust piece.
4. The shaped clamping jaw of one of claims 1 to 3, characterized in that the thrust piece (26) is adapted to be moved by means of a threaded rod (32) guided in an internal thread (30) disposed in the adjacent frame leg (16').
5. The shaped clamping jaw of one of claims 1 to 4, characterized in that the clearance of the clamping opening (16) varies continuously or in steps transversely with respect to the frame legs (18', 18'') which are essentially parallel with respect to the direction of movement (34) of the thrust piece (26) along these frame legs.
6. The shaped clamping jaw of claim 5, characterized in that the clearance decreases from the movable thrust piece (26) toward the fixed abutment piece (16'').
7. The shaped clamping jaw of claim 5, characterized in that the clearance decreases from the movable thrust piece (26) and from the movable abutment piece toward the frame center.
8. The shaped clamping jaw of one of claims 1 to 7, characterized in that the clamping rams (20, 20') are spring-loaded in their direction of movement.
9. The shaped clamping jaw of claim 8, characterized in that the clamping rams have a rearward axially centered blind bore (40) for accepting a compression spring (38) which is borne on a frame-fixed bearing surface (48).
10. The shaped clamping jaw of claim 9, characterized in that the bearing surface (48) is formed by a frame-fixed bearing plate (40) disposed parallel with respect to the frame plane.
11. The shaped clamping jaw of claim 9 or 10, characterized in that the compression spring (38) is formed to be a helical compression spring clamped between the bearing surface (48) and the clamping ram (20, 20'), bridging the free gap.
12. The shaped clamping jaw of claim 11, characterized in that the helical compression spring (38) is screwed with its end turns (39), which lie against each other when compressed, onto a thread (41, 43) on the bearing surface side and/or the clamping ram side.
13. The shaped clamping jaw of claim 11, characterized in that the helical compression spring (38) is fastened with its end turns (39), which lie against each other when compressed, in a recess (45', 45'') on the bearing surface side and/or the clamping ram side by means of an adhesive or a screw connection.
14. The shaped clamping jaw of one of claims 9 to 13, characterized in that a stop and guide bolt (49) is engaged in the blind bore (40) of individual clamping rams (20), which bolt (49) protrudes over the bearing surface (48) and penetrates the compression spring (38).
15. The shaped clamping jaw of claim 14, characterized in that the stop and guide bolt (49) is adjustable with respect to the length of its part which protrudes over the bearing surface (48).
16. The shaped clamping jaw of one of claims 9 to 15, characterized in that a guide sleeve (42), which de-limits with its outer surface an annular space (44) for the compression spring (38), which is formed to be a helical compression spring, is inserted into the blind bore (40).
17. The shaped clamping jaw of claim 16, characterized in that a guide bolt (50) which protrudes over the bearing plate (48) is engaged in the guide sleeve (42).
18. The shaped clamping jaw of claim 17, characterized in that the guide sleeve (42) comprises a stop (55) for a stop collar (52) formed onto the free end of the guide bolt (50), which stop is formed by a tubular retraction at the end-side.
19. The shaped clamping jaw of claim 17 or 18, characterized in that the guide bolt (50) is formed to be a head bolt, the head (52) of which, which engages the guide sleeve (42) with free play, forms the stop collar, and the end of which which is opposed to the head is affixed, preferably glued, soldered or welded, to the bearing plate (48).
20. The shaped clamping jaw of one of claims 1 to 8, characterized in that the clamping rams (20, 20') lie with a rearward abutment surface (83) against the surface (84) of a padding layer (80) which is clamped in the frame and which is elastically resilient in the direction of movement of the clamping rams (20, 20').
21. The shaped clamping jaw of claim 20, characterized in that the clamping rams (20, 20') comprise an anchoring pin (85) which axially protrudes over the rearward abutment surface (83) and which engages in an open-edged opening of the padding layer (80).
22. The shaped clamping jaw of claim 21, characterized in that the anchoring pin (85) has a snap-in thickened portion (81) which snaps into the open-edged opening in the padding layer.
23. The shaped clamping jaw of one of claims 1 to 22, characterized in that the clamping rams (20, 20') comprise a ball socket (53) open toward the front face for accepting a clamping ball which is rotatable within the ball socket (53) and is flattened at its segment which protrudes over the socket opening, forming the front face (22).
24. The shaped clamping jaw of claim 23, characterized by a bore (60) which leads preferably axially from the blind bore (40) to the ball socket (53) and is adapted to be subjected to pressurized air.
25. The shaped clamping jaw of one of claims 1 to 24, characterized in that the lateral surfaces of the clamping rams (20, 20') which lie against the thrust piece (26) and/or the abutment piece (16'') are flattened thereto in a plane-parallel manner.
26. The shaped clamping jaw of one of claims 1 to 25, characterized by a device for mutually retracting the clamping rams (20, 20') to their end position within the clamping frame (12).
27. The shaped clamping jaw of claim 26, characterized in that the retracting device (71, 72) is adapted to be actuated mechanically, pneumatically, hydraulically or electromagnetically.
28. The shaped clamping jaw of one of claims 14 to 27, characterized in that the guide bolts (50) are attached to the frame.
29. The shaped clamping jaw of one of claims 17 to 27, characterized in that the guide bolts (50) are fixed to a common retracting plate (72) which is adapted to be moved with respect to the clamping frame (12) transversely with respect to the frame plane.
30. The shaped clamping jaw of one of claims 1 to 29, characterized in that the thrust piece (26) is formed to be an angled part which comprises an angle leg (92) which is aligned parallel to the direction of movement (34) and is supported directly or indirectly by the adjacent frame leg (18').
31. The shaped clamping jaw of one of claims 1 to 30, characterized in that the clamping rams (20, 20') have in their extreme end position relative to the frame opening (14) a length and/or front face contour which is matched to the surface contour of the workpiece (24) to be clamped.

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