EP2626173B1 - Jaw for a clamping device - Google Patents

Description

The present invention relates to a clamping claw for a clamping device for clamping a workpiece to a clamping surface of a clamping body.

Such a clamping claw serves to transmit a clamping force from the clamping device to the workpiece to be clamped.

Known Spannpratzen are designed as solid, one-piece metal body.

The FR 2 497 140 A1 , the US Pat. No. 5,836,574 , the DE 831 530 C and the DE 198 27 396 A1 disclose clamps according to the preamble of claim 1.

The present invention has for its object to provide a clamping claw of the type mentioned, which has a low weight, but still sufficient strength for the transmission of a high clamping force on the workpiece to be clamped.

This object is achieved by a clamping claw according to claim 1.

The multi-part construction of the clamping claw according to the invention offers the advantage of a reduced weight and a lower material requirement, yet sufficient mechanical strength is ensured in order to transfer a sufficiently high clamping force of the clamping claw on the workpiece to be clamped can.

Due to the distance between the two side walls of the main body, the outer contour of the contact surface, on which the base body of the clamping claw rests on the workpiece to be clamped, increased, without requiring correspondingly more material for the body is needed.

Preferably, the side cheeks are spaced apart in all their sections.

Each of the side cheeks of the main body of the clamping claw according to the invention can each be formed in one piece or a plurality of layers.

The side cheeks are preferably connected to each other by positive engagement and / or by frictional connection.

The clamping claw comprises at least one connecting element which is positively connected to at least one of the side cheeks.

Preferably, such a connecting element is integrally formed.

In a preferred embodiment, it is provided that at least one connecting element is positively connected to both side cheeks.

For producing a positive connection with at least one of the side cheeks, it is favorable that at least one connecting element has at least one rivet head.

Such a rivet head can be produced, for example, during the assembly of the clamping claw by press molding, preferably from a rivet head preform.

Alternatively or additionally, it may be provided that the clamping claw comprises at least one connecting element which is non-positively connected to at least one of the side cheeks.

Such a connecting element is preferably formed in one piece.

Furthermore, it is advantageous if at least one connecting element is non-positively connected to both side cheeks.

In particular, it can be provided that at least one connecting element is connected to at least one of the side cheeks, preferably with both side cheeks, by press fitting.

In order to increase the weight and material savings in the inventive clamping claw, it can be provided that at least one of the side cheeks is provided with recesses.

Such recesses may extend through the respective side cheek or be formed as depressions on one of the outer surfaces of the side cheek.

In a preferred embodiment of the invention it is provided that the surface covered by the recesses amounts to at least approximately one quarter of the total area of an outer surface, preferably a main surface, of the respective side wall.

It is particularly favorable if the surface of the recesses amounts to at least approximately one third, in particular at least approximately half, of the total area of an outer surface, preferably a main surface, of the respective side cheek.

In order to increase the stability of a recessed side cheek, it is advantageous if at least one recess has at least one edge portion which is at an angle of about 20 ° to about 50 °, preferably at an angle of about 20 ° to about 40 °, inclined relative to a clamping direction of the main body of the clamping claw.

The clamping direction of the main body of the clamping claw extends perpendicular to a contact surface, with which the base body rests during operation of the clamping device on the workpiece to be clamped.

In a preferred embodiment of the invention include at least two recesses with each other a web, the longitudinal direction inclined at an angle of about 20 ° to about 50 °, preferably at an angle of about 20 ° to about 40 °, relative to a clamping direction of the main body of the clamping claw runs.

In order to avoid a notch effect in corner regions of recesses on the side cheeks, it is favorable if at least one recess has at least one rounded corner region.

Preferably, all corner areas are rounded in at least one recess.

It is particularly favorable if all corner regions of all recesses of at least one side cheek are rounded.

Furthermore, the clamping claw according to the invention preferably comprises at least one clamping disc held displaceably relative to the side cheeks on the base body of the clamping claw.

In particular, it can be provided that a clamping screw of the clamping device extends through a passage opening in the clamping disk.

Due to the displaceability of the clamping disk relative to the main body of the clamping claw, the position of the clamping screw can be selected relative to the workpiece to be clamped in the desired manner.

In a preferred embodiment of the clamping claw according to the invention it is provided that the clamping claw comprises at least two interconnected and together displaceable clamping discs.

By rotation of the clamping claw about a longitudinal axis of the main body can then each one of these clamping discs are used to support a clamping nut of the clamping device.

The two clamping disks are preferably connected to each other by positive locking and / or by frictional connection.

A form-fitting connection can be produced, in particular, in that one or more rivet heads, for example by press-forming, are formed on a connecting element, by which the two clamping disks are connected to one another.

In order to hold the clamping plate captive on the main body of the clamping claw, it is advantageous if the clamping claw comprises at least one stop for limiting the displacement of the clamping plate relative to the main body of the clamping claw.

The clamping body, on the clamping surface of which the workpiece to be clamped is clamped, can be designed, for example, as a machine table or as a clamping pallet.

Further features and advantages of the invention are the subject of the following description and drawings of an embodiment.

Fig. 1

eine schematische Seitenansicht einer Spannvorrichtung, mittels welcher ein Werkstück an einer Spannfläche eines Aufspannkörpers eingespannt ist;

Fig. 2

eine Draufsicht auf die Spannvorrichtung, das Werkstück und den Aufspannkörper aus Fig. 1 von oben;

Fig. 3

eine schematische perspektivische Darstellung einer Spannpratze der Spannvorrichtung aus den Fig. 1 und 2;

Fig. 4

eine schematische Seitenansicht der Spannpratze aus Fig. 3;

Fig. 5

eine schematische Draufsicht von oben auf die Spannpratze aus den Fig. 3 und 4, mit der Blickrichtung in Richtung des Pfeiles 5 in Fig.4;

Fig. 6

eine der Fig. 5 entsprechende Draufsicht auf die Spannpratze von oben, wobei eine Spannscheibe der Spannpratze von der in Fig. 5 dargestellten Stellung in eine Anschlagstellung verschoben worden sind;

Fig. 7

eine schematische Vorderansicht der Spannpratze aus den Fig. 3 bis 6, mit der Blickrichtung in Richtung des Pfeiles 7 in Fig. 4;

Fig. 8

einen schematischen Querschnitt durch die Spannpratze aus den Fig. 3 bis 7 im Bereich eines Verbindungselements, welches zwei Seitenwangen der Spannpratze formschlüssig miteinander verbindet, längs der Linie 8 - 8 in Fig. 5; und

Fig. 9

einen der Fig. 8 entsprechenden schematischen Querschnitt durch die Spannpratze im Bereich des Verbindungselements, während der Montage der Spannpratze, bevor Nietköpfe an dem Verbindungselement für die Herstellung der formschlüssigen Verbindung durch Pressformen erzeugt worden sind.

In the figures show:

Fig. 1

a schematic side view of a clamping device by means of which a workpiece is clamped to a clamping surface of a clamping body;

Fig. 2

a plan view of the clamping device, the workpiece and the clamping body Fig. 1 from above;

Fig. 3

a schematic perspective view of a clamping claw of the clamping device of the Fig. 1 and 2 ;

Fig. 4

a schematic side view of the clamping claw Fig. 3 ;

Fig. 5

a schematic plan view from above on the clamping claw of the Fig. 3 and 4 , looking in the direction of arrow 5 in Figure 4 ;

Fig. 6

one of the Fig. 5 corresponding top view of the clamping claw from above, wherein a clamping disc of the clamping claw of the in Fig. 5 shown position have been moved to a stop position;

Fig. 7

a schematic front view of the clamping claw of the Fig. 3 to 6 , looking in the direction of the arrow 7 in Fig. 4 ;

Fig. 8

a schematic cross section through the clamping claw of the Fig. 3 to 7 in the region of a connecting element, which connects two side cheeks of the clamping claw form-fitting together, along the line 8 - 8 in Fig. 5 ; and

Fig. 9

one of the Fig. 8 corresponding schematic cross section through the clamping claw in the region of the connecting element, during the assembly of the clamping claw, before rivet heads have been produced on the connecting element for the production of the positive connection by press molding.

Identical or functionally equivalent elements are denoted by the same reference numerals in all figures.

One in the Fig. 1 and 2 illustrated, as a whole with 100 designated clamping device is used for clamping a workpiece 102 on a clamping surface 104 of a clamping body 106th

The clamping body 106 may be formed, for example, as a machine table or as a clamping pallet.

The clamping device 100 comprises a clamping claw 108 which, during operation of the clamping device 100, is supported on a clamping surface 110 of the workpiece 102 and on a supporting surface 112 of a clamping support or a supporting body 114.

The support body 114 is clamped in the operation of the clamping device 100 as well as the workpiece 102 against a clamping surface 104 of the clamping body 106.

The clamping claw is in detail in the Fig. 3 to 9 and comprises a base body 116, with which the clamping claw 108 can be applied to the workpiece 102 and to the support body 114.

The main body 116 comprises two side cheeks 118, which both extend in a longitudinal direction 120 of the main body 116 and are spaced apart from one another in a transverse direction 122 of the main body 116 that is perpendicular to the longitudinal direction 120.

The side cheeks 118 may be formed plate-shaped, for example.

The thickness d of the sidewalls 118, that is to say their extent in the transverse direction 122, is preferably constant.

The side cheeks 118 may be mirror-symmetrical to each other.

It is particularly favorable if the side cheeks 118 are formed substantially identical to one another.

Each side wall 118 has a contact surface 124, with which the side cheek 118 can be applied to the clamping surface 110 of the workpiece 102 and / or to the support surface 112 of the support body 114.

The contact surface 124 is preferably in the plane defined by the longitudinal direction 120 and the transverse direction 122 of the main body 116 of the clamping claw 108.

A clamping direction 126 of the clamping claw 108, along which the clamping claw 108 exerts a clamping force on the workpiece 102, is perpendicular to the contact surfaces 124 of the side walls 118 and preferably perpendicular to the longitudinal direction 120 and to the transverse direction 122 of the base body 116th

The side cheeks 118 are connected to each other by means of a plurality of connecting elements 128 which extend in the transverse direction 122 of the base body 116.

Two of these connecting elements 128, namely a first connecting plate 130 and a second connecting plate 132, are substantially parallelepiped-shaped or plate-shaped, while a further connecting element 128 is designed as a, for example substantially cylindrical, connecting rod 134.

The connecting rod 134 comprises a middle section 136 arranged between the side cheeks 118 and two end sections 138 which have a smaller diameter than the central section 136 and engage in passage openings 140 formed in the side cheeks 118 complementary thereto.

The end portions 138 of the connecting rod are frictionally held by press-fitting on the respectively associated side cheek 118, so that the two side cheeks 118 are frictionally connected to each other by the connecting rod 134.

The connecting plates 130 and 132 comprise a substantially parallelepiped-shaped central portion 142, which is arranged between the side cheeks 118 in the assembled state of the clamping claw 108, and two connecting portions 144 protruding from the middle portion 142 in the transverse direction 122, which pass through openings 146, 14a, which are complementary thereto extend through the side cheeks 118 (see in particular Fig. 8 ).

In the in Fig. 9 illustrated initial state of the connecting plate 132 have their connecting portions 144 at their respective, the central portion 142 remote from the free end each have a Nietkopf preform 148, which includes an end piece 150 which is connected via two webs 152 with a base portion 154 of the respective connecting portion 144.

Between the webs 152, a recess 156 is arranged, which in the in Fig. 9 illustrated initial state of the connecting plate 132, the tail 150 separates from the base part 154.

In this initial state, the extension s of the rivet head preform 148, that is to say its extent in the longitudinal direction of the passage opening 146, is slightly smaller than the extent S of the passage opening 146 in its longitudinal direction, so that the connection section 144 in this initial state is readily accessible through the passage opening 146 can be inserted.

When both connecting portions 144 have been inserted through the respectively associated passage opening 146, the rivet head preforms 148 of the connecting portions 144 are deformed by press molding so that the end piece 150 abuts against the base part 154 and the webs 152 buckle so that from the rivet head preform 148 of the Fig. 8 rivet head 158 is formed, which in the longitudinal direction of the passage opening 146 has a greater extent s 'than the rivet head preform 148. The extent s' is greater than the extent S of the passage opening 146 in the longitudinal direction thereof, so that the rivet head 158 has undercuts 160 , which prevent a retraction of the rivet head 158 through the respective associated passage opening 146.

Im in Fig. 8 illustrated assembled state of the base body 116 thus the two side cheeks 118 are positively connected to each other by the connection plate 132 provided with rivet heads 158.

In order to facilitate the deformation of the connection plate 132 during compression molding, it may be provided that the connection plate 132 is provided in the region of the transition between the middle section 142 and the connection sections 144, each with a recess 162 which may, for example, have a substantially circular section-shaped edge.

The first connecting plate 130 is essentially the same as the second connecting plate 132 and is inserted in a corresponding manner in through openings of the side walls 118 and connected by forming rivet heads 158 form-fitting manner with two side cheeks 118.

Furthermore, the clamping claw 108 comprises two clamping disks 163, which are likewise connected to one another by two connecting elements 164, in particular in a form-fitting manner.

The connecting elements 164 may be formed, for example, as connecting plates 166, which are formed substantially parallelepiped-shaped and extend substantially parallel to the side walls 118 in the longitudinal direction 120 and in the clamping direction 126 of the base body 116.

The connecting elements 164 have in the transverse direction 122 of the main body 116 a greater distance from each other than the opposite outer sides 168 of the side walls 118, so that the clamping discs 163 together with the connecting elements 164 form a frame 170 which surrounds the base body 116 and in the longitudinal direction 120 is displaceable relative to the base body 116.

Since the distance between the mutually facing inner sides 171 of the connecting elements 164 of the clamping disks 163 is smaller than the distance between the opposite outer sides 172 of the rivet heads 158 of the connecting elements 128 of the side walls 118, the rivet heads 158 each form a stop 174, which the displacement of the connecting elements 164 and thus the frame 170 and the clamping disks 163 in the longitudinal direction 120 of the base body 116 is limited to the front or to the rear.

In the in Fig. 6 shown position of the clamping disks 163 of the frame 170 is applied to the rear stops 174a.

Out of this in Fig. 6 shown sliding end position of the frame 170 with the clamping disks 163 is displaceable into a (not shown) opposite displacement end position in which the connecting elements 164 of the clamping disks 163 abut the front stops 174b.

Fig. 5 shows an intermediate position of the frame 170 with the clamping disks 163 lying between these two displacement end positions.

The connecting elements 164 of the clamping disks 163 are, for example, in the same manner positively connected to the two clamping disks 163, as has been described above in connection with the second connecting plate 132 with respect to the form-locking connection with the two side walls 118.

Each of the tension discs 163 has, for example, a substantially central, and preferably substantially cylindrical, passage opening 176, wherein the two passage openings 176 of the tension discs 163 are preferably aligned substantially coaxially with one another and coaxially with the tension direction 126.

The tensioning device 100 further comprises a clamping screw 178 with an external thread 180, with a shaft section 182 adjoining the external thread 180 and with a screw head 184 adjoining the end of the shaft section 182 facing away from the external thread 180, preferably in the form of a sliding block 186, in particular is formed with a substantially T-shaped cross-section.

During operation of the clamping device 100, the screw head 184 of the clamping screw 178 is guided in a complementary groove 188 of the clamping body 106, which thus preferably has a substantially T-shaped cross section.

The external thread 180 of the clamping screw 178 extends during operation of the clamping device 100 substantially parallel to the clamping direction 126 through the passage openings 176 of the clamping disks 163 and between the side walls 118 of the base body 116 of the clamping claw 108 therethrough.

On the clamping body 106 facing away from the end portion 190 of the external thread 180 of the clamping screw 178, a clamping nut 192 is screwed.

By tightening the clamping nut 192 against the clamp body 163 facing away from the clamping plate 163a acting in the clamping direction 126 clamping force of the clamping nut 192 via the clamping plate 163a and the base 116 of the clamping claw 108 on the workpiece 102 and on the support body 114 is transmitted, so that the Workpiece 102 and the support body 114 are pressed with the clamping force against the clamping surface 104 of the clamping body 106. In this, in the Fig. 1 and 2 illustrated clamping state of the clamping device 100 are thus the workpiece 102 and the support body 114 clamped by means of the clamping device 100 between the clamping claw 108 and the clamping body 106.

In this clamping position, the workpiece 102 may be subjected to a workpiece machining, for example a machining operation.

By loosening the clamping nut 192 from the clamping disk 163a, the tension of the workpiece 102 is released on the clamping body 106, after which the workpiece 102 can be released from the clamping body 106.

To save material and weight, the side cheeks 118 of the base body 116 of the clamping claw 108 may be provided with recesses, which preferably extend in the transverse direction 122 of the base body 116 through the respective side cheek 118 therethrough.

In principle, however, it can also be provided that the recesses 194 form only depressions on one of the main surfaces (outer side 168 or inner side 202 facing the other side cheek 118) of the respective side cheek 118 and do not pass through the entire thickness of the respective side cheek 118 extend.

Preferably, the surface covered by the recesses 194 on a main surface 168, 202 of a side wall 118 is at least approximately one quarter of the total area of the respective main surface 168, 202 of the side wall 118 framed by the outer contour of the side wall 118.

It is even more favorable if this surface portion of the recesses 194 on the total area of the main surface 168, 202 of the side wall 118 is at least approximately one third, in particular at least approximately half.

In order to avoid a notch effect in the corner regions of the recesses 194, it is favorable if at least one corner region 196 of at least one recess 194 is rounded, that is to say has no sharp edge.

Preferably, all corner regions 196 of at least one recess 194 are rounded.

It is particularly favorable if all corner regions 196 of all recesses 194 of the side cheeks 118 are rounded.

The recesses 194 can basically have any shape, for example a circular or polygonal shape.

In a preferred embodiment shown in the figures, most of the recesses 194 are substantially triangular, with rounded corner portions 196 formed.

If the recesses 194 have rectilinear edge sections 198, then it is favorable if some of these edge sections 198, preferably the majority of these edge sections 198, with respect to the clamping direction 126 of the base body 116 at an angle in the range of about 20 ° to about 50 °, preferably about 20 ° to about 40 °, are inclined.

As a result, a particularly high mechanical stability of the side cheeks 118 is achieved even with a large area proportion of the recesses 194.

To produce the above-described tensioning device 100, the procedure is as follows:
The side cheeks 118 are cut out of a starting material, for example of a metallic sheet, for example punched out or cut out (for example by means of a laser).

The side cheeks 118 can thus be designed in particular as web plates.

When separating the side walls 118 from the starting material and the recesses 194 can be introduced into the side walls 118.

Subsequently, the side walls 118 are positively connected by means of the first connection plate 130 and the second connection plate 132 and by means of the connecting rod 134 with each other to the base body 116, so that the side walls 118 are captively connected to each other.

The clamping disks 163 are likewise cut out of a starting material, for example of a sheet metal material, in particular punched out or cut out (for example by means of a laser), arranged on opposite sides of the base body 116 and interconnected by means of the connecting elements 164, in particular in a form-fitting manner.

Subsequently, the clamping device 100 is completed by inserting the clamping screw 178 in the passage openings 176 of the clamping disks 163 and screwing the clamping nut 192 on the end portion 190 of the external thread 180 of the clamping screw 178.

Since the clamping claw 108 is provided on two opposite sides, each with a clamping plate 163, the clamping claw 108 can also be used in a second working position in which the base body 116 of the clamping claw 108 relative to the in the Fig. 1 and 2 shown first working position is rotated by an angle of 180 ° about the longitudinal direction 120.

In the second working position, the clamping claw 108 is in operation of the clamping device 100 with the contact surfaces 124 of the side cheeks 118 opposite, also parallel to the longitudinal direction 120 and the transverse direction 122 aligned second contact surfaces 200 on the workpiece 102 to be clamped and possibly also on a support body 114.

The clamping claw 108 and / or the other components of the clamping device 100 are preferably made of a metallic material, for example of a steel material.

In principle, however, any other material which has suitable mechanical properties, for example a fiber-reinforced plastic material, can also be used for the components of the clamping claw 108 and for the other components of the clamping device 100.

Claims (14)

1. Clamping claw for a clamping device (100) for clamping a workpiece (102) to a clamping face (104) of a clamping body (106),
   wherein the clamping claw (108) comprises a base body (116) which comprises two side cheeks (118) which are arranged at a distance from each other at least in sections and are captively connected to each other,
   characterized in that
   the clamping claw (108) comprises at least one connecting element (130, 132) which is connected to at least one of the side cheeks (118) in a form-fitting manner, has at least one rivet head (158), and is of substantially plate-like configuration.
2. Clamping claw in accordance with Claim 1, characterized in that the side cheeks (118) are connected to each other by form fit and/or by force fit.
3. Clamping claw in accordance with either one of Claims 1 or 2, characterized in that at least one rivet head (158) is produced by press forming.
4. Clamping claw in accordance with any one of Claims 1 to 3, characterized in that the clamping claw (108) comprises at least one connecting element (134) which is connected to at least one of the side cheeks (118) in a force-fit manner.
5. Clamping claw in accordance with Claim 4, characterized in that at least one connecting element (134) is connected to at least one of the side cheeks (118) by interference fit.
6. Clamping claw in accordance with any one of Claims 1 to 5, characterized in that at least one of the side cheeks (118) is provided with recesses (194).
7. Clamping claw in accordance with Claim 6, characterized in that the area of the recesses (194) is at least about a fourth of the total area of an outer face (168, 202) of the respective side cheek (118).
8. Clamping claw in accordance with either one of Claims 6 or 7, characterized in that at least one recess (194) has at least one rim section (198) which runs inclined at an angle of about 20° to about 50° in relation to a clamping direction (126) of the base body (116) of the clamping claw (108).
9. Clamping claw in accordance with any one of Claims 6 to 8, characterized in that at least one recess (194) has at least one rounded corner region (196).
10. Clamping claw in accordance with any one of Claims 1 to 9, characterized in that the clamping claw (108) comprises at least one clamping disc (163) which is held on the base body (116) of the clamping claw (108) so as to be displaceable relative to the side cheeks (118).
11. Clamping claw in accordance with Claim 10, characterized in that the clamping claw (108) comprises at least two clamping discs (163) which are connected to each other and are displaceable together.
12. Clamping claw in accordance with Claim 11, characterized in that the clamping discs (163) are connected to each other by form fit and/or by force fit.
13. Clamping claw in accordance with either one of Claims 11 or 12, characterized in that the clamping claw (108) comprises at least one stop (174) for delimiting the displacement path of the clamping disc (163) relative to the base body (116) of the clamping claw (108).
14. Clamping claw in accordance with any one of Claims 10 to 13, characterized in that a clamping screw (178) extends through a through-opening in the at least one clamping disc (163).

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