GB2514907A

GB2514907A - Clamping system for clamping a punch on a ram of an impact extrusion press

Info

Publication number: GB2514907A
Application number: GB1406434.9A
Authority: GB
Inventors: Carsten Brechling; Thomas Gorke
Original assignee: L Schuler GmbH
Current assignee: L Schuler GmbH
Priority date: 2013-04-22
Filing date: 2014-04-09
Publication date: 2014-12-10
Anticipated expiration: 2034-04-09
Also published as: DE102013006831A1; DE102013006831B4; GB2514907B; GB201406434D0

Abstract

A clamping system 101 for clamping a punch 103 on a ram 116 of an impact extrusion press 117 comprises a clamping head 111 fastened to the ram, an adapter or collet 113 and the punch 103, the clamping head 111 having a conical flange space 112 to receive the conical collet 104 and the collet 104 has a clamping channel to receive a clamping portion 105 of the punch 103, the clamping head 111 having further a base body 114 and a movable chuck 115, the collet 104 and chuck 115 having complementary bayonet formations 119, 120, the chuck moving linearly between a release position (F figure 5) and a clamping position (S figure 5) pressing the collet 104 into the flange space 102. The chuck 115 may be moved to the clamping position (S figure 5) by force producing means such as a cup spring package 125 and may further be moved to the release means by counter force means such as cylinder 132. A sensor (250 figure 6) may be used to sense the presence of the collet (204 figure 6).

Description

S

Clamping system for clamping a punch on a ran of an impact extrusion press The invention relates to a clamping system for clamping a punch on a ram of an impact extrusion press according to the preamble of claim 1.

A clamping system for clamping a punch on a ram of an impact extrusion press is known from the prior art shown in Fig. 1, the clamping system having a clamping head fastened to the ram, an adapter and the punch, the clamping head having a conical flange space to receive the adapter configured as a conical collet and the collet having a clamping channel to receive the clamping portion of the punch. The drawback in a clamping system of this type is the laborious assembly and disassembly of the punch on the clamping head using a hook wrench acting on a union nut.

The object of the invention is to propose a clamping system, in which the assembly and disassembly of the punch on/from the clamping head is simplified.

This object is achieved proceeding from the features of the preamble of claim 1 by the characterising features of claim 1.

Advantageous and expedient developments are given in the sub-claims.

In the clamping system according to the invention for clamping a punch on a ram of an impact extrusion press, which is configured, in particular, as an impact extrusion press punch clamping system, the clamping head comprises a base body and a chuck, the chuck having a first bayonet geometry, the collet forming a clamping unit together with the punch, the collet having a second bayonet geometry and the two bayonet geometries being adapted to one another in such a way that they can be coupled to one another by an insertion-rotary movement and can be separated from one another by a rotary-pulling movement, the chuck being guided on the base body, the chuck being linearly movable between a release position and a clamping position in relation to the base body while entraining the clamping unit coupled to the chuck by the insertion-rotary movement in such a way that the collet of the clamping unit in the clamping position is pressed into the flange space of the clamping head. Using a clamping system of this type, the coupling and uncoupling of the punch when the adapter is mounted on the punch or when the collet is mounted on the punch, is possible by means of an insertion-rotary movement or rotary-pulling movement, which is easy to carry out when the clamping head is in a release position. Owing to the simplification of the coupling and uncoupling process, punches can be changed substantially more quickly and with a substantially higher process safety for impact extrusion presses in comparison to the clamping system described in Fig. 1. The core of the invention is therefore a bayonet holding system, which is suitable to clamp a punch held in a collet.

Furthermore, the invention provides equipping the clamping head with at least one force-production means, the force-production means being arranged between the base body and the chuck and the force-production means pressing the chuck into the clamping position, the clamping head comprising at least one counter-force production means, the counter-force production means being arranged between the base body and the chuck and the counter-force production means displacing the chuck, upon activation of the counter-force production means, against the force of the force-production means into the release position. As a result, a secure retention of the clamping unit in the clamping head is ensured, which can be eliminated in a targeted manner by the counter-force production means. To eliminate the clamping position, the counter-force production means has a maximum force that is greater than a maximum force of the force-production means.

The invention also provides that the force-production means be configured as a spring means. This ensures that the force required for the clamping position is constant and is available independently of an energy supply.

Furthermore, the invention provides that the force-production means is to be provided with a pin anchored in the base body of the clamping head, a cup spring package guided on the pin and a lock nut screwed on to a free end of the pin, the cup spring package being arranged between the lock nut and the chuck that is also guided on the pin, and the counter force-production means being arranged between the base body of the clamping head and the chuck. Owing to a linear arrangement of this type of the components, the clamping head has compact dimensions.

The invention also provides that the counter force-production means be configured as a drive means, which can be driven by an energy source, the counter-force production means in particular comprising a cylinder that can be actuated hydraulically or pneumatically or electrically. A configuration of this type can easily be realised on an impact extrusion press as energy sources of this type are available here.

A development of the invention provides that the clamping system be equipped with a plurality of force-production means, the force-production means being arranged around the chuck and force vectors of the force-production means being oriented, in particular, parallel to an insertion direction for the clamping unit. This allows a compact design of the clamping head to be retained while simultaneously realising high clamping forces.

According to the invention, the clamping unit comprises an entrainer and the clamping head comprises a stop, the entrainer resting on the stop in the clamping position. As a result, it is possible to safely carry out the insertion-rotary movement required for coupling completely as, after insertion, rotation has to take place until abutment is achieved.

A development of the invention provides that the clamping head be equipped with a sensor, the sensor detecting the abutment of the entrainer on the stop. The successful conclusion of the insertion-rotary movement required for coupling can thus be detected electronically and therefore integrated into safety monitoring.

The invention provides a cooperation of this type of the chuck and collet in the clamping position in that the collet, upon an activation of the counter-force production means, is moved from the chuck out of the clamping position counter to the insertion direction and is thus released from the base body of the clamping head. Owing to an automated removal of this type of the clamping unit or the collet from the conical flange space of the base body of the clamping head, a disassembly of the clamping unit is substantially simplified for a user as only a rotary movement is still necessary by hand to remove the clamping unit from the clamping head. Due to the prior release of the collet from the base body, a smoothness of the rotary movement is ensured.

Furthermore, the invention provides that the punch be secured by a retaining ring arranged on the punch and a clamping ring arranged on the punch, on the collet. The clamping ring means that the connection is secured against the clamping unit on the punch being pressed too hard into the clamping head and the punch being pushed by the collet. The clamping ring also, in particular, prevents the punch slipping out of the collet before clamping. The retaining ring, when the impact extrusion press is working, prevents the punch being pulled out of the collet when there are lower clamping forces than process forces.

The invention also provides that the chuck be guided on the base body and that the base body be equipped with a bore, in which the pin of the force-production means is anchored. As a result, the chuck is securely connected to the base body.

Finally, the invention provides that the clamping head be equipped with a pressure piece, the pressure piece being arranged in the flange space and being configured in such a way that, when the clamping unit is mounted, said pressure piece opposes the collet without contact and has flat contact with the punch. As a result, forces that are axially directed from the ram by way of the base body and the pressure piece can be transmitted directly to the punch.

In the sense of the invention, a bayonet geometry of the collet and a bayonet geometry of the chuck are taken to mean two shapings of components adapted to one another, which, by means of an insertion-rotary movement of one of the components relative to the respective other component, lead to a positive connection that is suitable to transmit forces in the insertion direction and counter to the insertion direction.

In the sense of the invention, a* clamping head is taken to mean a chuck, which is arranged on a machine and with which a tool formed by a clamping unit can be clamped.

Further details of the invention are described in the drawings with the aid of schematically shown embodiments.

In the drawings: Fig. 1 shows a clamping system according to the prior art in a schematic view; Fig 2 shows a first embodiment variant of a clamping unit, which comprises a punch and a collet; Fig. 3 shows a clamping head of the first embodiment variant, which is in a release position; Fig. 4 shows the clamping head shown in Fig. 3 in a clamping position; Fig. 5 shows a further view of the clamping head of the first embodiment variant, a lower half of the clamping head being in a release position and an upper half of the clamping head being in a clamping position; Fig. 6 shows a second embodiment variant of a clamping system in a sectional side view, the sectional view running in accordance with the section line VI-VI shown in Fig. 6; Fig. 7 shows a further view of the clamping system shown in Fig. 6, the sectional view running in accordance with the section line Vu-Vu shown in Fig. 8, and Fig. 8 shows a plan view of the clamping system shown in Figs. 6 and 7.

A clamping system 1 according to the prior art is shown in Fig. 1 in a schematic view. The clamping system 1 is provided to clamp a punch 2 on a ram 3 of an impact extrusion press 4 and is configured as an impact extrusion press punch clamping system 5. The clamping system 1 comprises a clamping head 6 fastened to the ram 3, an adapter 7 and the punch 2. In this case, the clamping head 6 comprises a base body 8 with a conical flange space 9 to receive the adapter 7 configured as a conical collet 10. Furthermore, the clamping head 6 comprises a *union nut 11, which can be screwed on to the base body 8 and, in its screwed-on position, presses the collet 10 into the flange space 9. The punch 2 is held here by a clamping portion 12 in a clamping channel 13 of the clamping head 6. Furthermore, the clamping head 6 also comprises a pressure piece 14, which is arranged in the flange space 9. A retaining ring 15, which secures the punch 2, is arranged on the clamping portion 12.

Figs. 2 to 5 show a first embodiment variant of a clamping system 101 according to the invention. Fig. 2 shows a sectional side view of a clamping unit 102 of the clamping system 101. The clamping unit 102 comprises a punch 103 and a collet 104, the punch 103 being held by a clamping portion 105 in the clamping channel 106 of the collet 104. Mounted on the punch 103 is a retaining ring 107, which opposes a step 108 of the clamping channel 106, so the punch 103, when it is pulled due to the process force in an arrow direction x from its clamping, cannot be pulled in an arrow direction x out of the collet 104 as the retaining ring 107 is supported against the step 108. Furthermore, a clamping ring 109 is arranged on the punch 103. The clamping ring 109 is clamped around the punch 103 in such a way that the latter, on insertion of the punch 103 into the collet 104 in an insertion direction x', serves as a stop, which runs against a front face 110 of the collet 104. The clamping system 101 according to the invention is provided for impact extrusion presses and thus forms an impact extrusion press clamping system 118. The same collet can be used for different punches. It is also provided that the same punch, together with different collets, forms a clamping unit.

The clamping system 101, apart from the clamping unit 102 shown in Fig. 2, also comprises a clamping head 111, which is in a release position F in Fig. 3, in which it is possible to couple the clamping unit 102 to the clamping head 111. using an insertion-rotary movement, the clamping unit 102 being inserted for this purpose with its collet 104 in the insertion direction x' into a flange space 112 of the clamping head 111 and then being rotated to the right about a longitudinal axis L by 330 in a rotational direction DR. As, by means of the collet 104, an adaptation to the flange space 112 is carried out, this is also called an adapter 113. The clamping head 111 comprises *a base body 114 and a chuck 115. With the base body 114, the clamping head 111 is fastened on a ram 116 of an impact extrusion press 117, not further shown. The clamping system 101 is therefore configured as an impact extrusion press clamping system 118. The collet 104 shown in Fig. 2 has a bayonet geometry 119, which cooperates with a bayonet geometry 120 of the clamping head 111 during the insertion-rotary movement described, the bayonet geometry 120 being implemented on the chuck 115. The clamping head 111 furthermore comprises six force production means 121 and six counter-force production means 122, which, pair-wise, form force units 123, only one force unit 123 being described below in more detail by way of example. The force production means 121 comprises a pin 124, which is anchored in a bore 114a of the base body 114 of the clamping head 111 and is oriented parallel to the insertion direction x'. Furthermore, the force production means 121 comprises a cup spring package 125 and a lock nut 127 screwed onto a free end 126 of the pin 124. In this case, the chuck 115 is guided with an annular flange 128 on the pin 124 and is pressed in the insertion direction x' by the cup spring package 125, which is supported on the lock nut 127. This pressure force of the cup spring package 125, in the release position F shown, of the clamping head ill counteracts the counter-force production means 122, which is arranged between the base body 114 and the flange 128 of the chuck 115, with such a large counter-force that the cup spring package is compressed and that the chuck 115 is displaced counter to the insertion direction x' in an ejection direction x away from the base body 114. This achieves the fact that a conical outer face 129 of the collet 104 indicated schematically in Fig. 3 during the insertion-rotary movement to be carried out for coupling, after insertion still does not have any flat contact with a conical contact face 130 of the flange space 112 and can thus be rotated with little resistance. The counter-force production means 122. is configured as a drive means 131, which is supplied by an energy source, not shown.

In the embodiment of the invention shown in Fig. 3, the counter-force production means 122 is formed by an annular cylinder 132 that can be actuated hydraulically, which, in the release position F of the clamping head 111, is pressurised and therefore extended. The other counter-force production means, not described in more detail, are also in each case formed by a cylinder of this type, which is in each case extended in the release position F. Fig. 4 shows the clamping head 111 known from Fig. 3 standing in a clamping position S. In the clamping position 5, the counter-force production means 122 is switched to be without power, so the force production means 121 presses the chuck 115 on its flange 28 in the insertion direction x' in the direction of the base body 114 of the clamping head 111. In this case, a force transmission takes place from the bayonet geometry 120 of the chuck 115 to the bayonet geometry 119 of the collet 104, not shown in Fig. 4, so the latter is pressed with its conical outer face 129 against the conical contact face 130 of the flange space 112 formed by the base body 114 and is thereby firmly received in the clamping head 111. In order to release the collet 104 or the entire clamping unit 102, as shown in Fig. 2, using the rotary-pulling movement from the clamping head 111, the chuck 115 is moved by an activation of the counter-force production means 122 into, the release position F shown in Fig. 3. The collet 104 is thus pulled from the chuck in the arrow direction x out of the flange space 112. As a result, the contact of its outer face 129 with the contact face 130 of the flange space 112 is released, so the clamping unit 102 can be completely decoupled from the chuck 115 using a low expenditure of force by a rotation to the left in a rotational direction DL and can be pulled out of the clamping head 111 tn the arrow direction x.

For better understanding, the clamping head 111 is again shown in Fig. 5 in such a way that the half located below the longitudinal axis L shows the clamping head ill in the release position F, as known from Fig. 3, and in that the half located above the longitudinal axis L shows the clamping head lii in the clamping position 5, as known from Fig. 4. It can be seen from this comparison that the counter-force production means 122 in the clamping position S and in the release position F are in difference positions and that the position of the chuck in relation to the base body 114 of the clamping head 111 is different according to the position of the counter-force production means 122, the chucic having a spacing AS in the clamping position S in relation to the base body 114 and the chuck having a spacing AF, which is greater than the spacing AS, in the release position F with respect to the base body 114. Furthermore, a pressure piece 133 can be seen in Fig. 5, which is arranged in the flange space 112. If the clamping unit, not shown in Fig. 5, is held in the clamping head 111 in the clamping position 5, the punch, not shown, is in contact with the pressure piece 133, so axially directed forces can be transmitted by the latter. It can be seen in Fig. 2 that the punch 103 projects for this purpose with a free end 134 beyond the collet 104, so the collet 104 opposes the pressure piece 133 without contact.

The clamping unit 102 shown in Fig. 2 comprises an entrainer 135, which comes into contact with a stop 136, shown in Fig. 3, of the clamping head 111 when the insertion-rotary movement, with which the clamping unit 102 is coupled to the clamping head 111, is completed. The entrainer 135 is configured as a component of the collet 104. The collet 104 comprises a further entrainer 136, which, when the punch 103 is inserted, rests on a flattened area 137 of the punch 103 and prevents a rotation of the punch 103 in relation to the collet 104.

Figs. 6 to 8 show a second embodiment variant of a clamping system 201 according to the invention, the second embodiment variant only differing in details from the first embodiment variant shown in Figs. 2 to 5. Fig. 6 shows the clamping system 201 in a sectional side view, the sectional view running in accordance with the section line VI-VI shown in Fig. 8. A clamping head 211, when a clamping unit 202 is inserted, is in a clamping position S, the clamping unit 102 comprising a punch 203 and a collet 204. The punch 203 rests on a pressure piece 233 of the clamping head 211. On completion of an insertion-rotary movement when the clamping unit 202 is coupled to the clamping head 211 and in the clamping position S, a sensor 250 arranged in the clamping head 211 is actuated by a bayonet geometry 219 of the collet 204, so that during coupling, the transition of the clamping head 211 from a release position into the clamping position S can be triggered by the sensor 250 and so that the correct seat of the clamping unit 202 in the clamping head 211 can be monitored during operation. An entrainer 236 can also be seen in Fig. 6, by means of which the punch 203 and the collet 204 can be held in a manner secured against rotation in relation to one another about a longitudinal axis L. In this case, the entrainer 236 acts on a flattened area 237 formed on the punch 203. A ram 216 of an impact extrusion press 217, on which the clamping head 211 is fastened by three screws 251, 252 and 253, is indicated by dashed lines in Fig. 6. Reference is also made in this regard to Figs. 7 and 8. Fig. 7 shows the screw 252 twice owing to the angled section course Vu-Vu.

According to an embodiment of Fig. 6, a component 254 designated a sensor 250 above is configured as a small hydraulic cylinder 255 with a continuous piston rod 256. The position of the piston rod 256 is detected, in particular at a defined crank angle, by a further, schematically indicated sensor SE attached to a machine body of the impact extrusion press. During clamping, the piston rod 256 retracts with its sensor-side piston rod end 256a. In this case, the hydraulic cylinder 255 is actuated, in particular, by the same working medium as the counter-force production means. A bayonet tooth 257 is worked differently to the other bayonet teeth 258 on the bayonet geometry of the collet 204. The bayonet tooth 257 has a free space 259. On completion of the insertion rotary movement, the free space 259 is such that the piston rod 256 with its bayonet-side piston rod end 256b retracts during the reduction in the pressure of the working medium until said piston rod is in the position shown in Fig. 6. If the free space 259 is not met by the piston rod end 25b, the sensor-side piston rod end 256a continues to be in front of the sensor SE. A position of this type of the piston rod 256 leads to a fault message and thus prevents the start-up of the impact extrusion press.

The invention 15 not limited to embodiments shown or described. Rather, it comprises developments of the invention in the framework of the patent claims.

List of reference numerals 1 clamping system 2 punch 3 ram 4 impact extrusion press impact extrusion press punch clamping system 6 clamping head 7 adapter 8 base body 9 flange space of 6 conical collet 10 11 union nut 12 clamping portion of 2 13 clamping channel in 10 14 pressure piece retaining ring 101 clamping system 102 clamping unit 103 punch 104 collet clamping portion of 103 106 clamping channel of 104 107 clamping ring on 103 108 step on 104 109 clamping ring on 103 front face 110 of 104 111 clamping head 112 flange space 113 adapter 114 base body of 111 chuck of 111 116 tarn of 117 117 impact extrusion press 118 impact extrusion press clamping system 119 bayonet geometry of 104 bayonet geometry of 115 121 force production means 122 counter-force production means 123 force unit 124 pin 124a bore 114a in 114 for 124 cup spring package 126 free end of 124 127 lock nut 128 annular flange 129 conical outer face of 104 conical contact face of 112 131 drive means 132 cylinder that can be hydraulically actuated 133 pressure piece 134 free end of 103 entrainer 13 stop 137 flattened area on 103 201 clamping 202 clamping unit 203 punch 204 collet 211 clamping head 216 ram 217 impact extrusion press 219 bayonet geometry. of 204 233 pressure piece 236 entrainer 237 flattened area on 203 250 sensor 251-253 screw 254 component 255 hydraulic cylinder 256 piston rod 256a, 25Gb piston rod end 257 bayonet tooth 258 bayonet tooth 259 free space of 257 AF spacing between 115 and 114 in the release position AS spacing between 115 and 114 in the clamping position DL rotational direction (left) DR rotational direction (right) F release position L longitudinal axis S clamping position SE second sensor x ejection direction, arrow direction insertion direction

Claims

Claims 1. Clamping system (1; 101; 201) for clamping a punch *(2; 103; 203) on a ram (3; 116; 216) of an impact extrusion press (4; 117; 217), in particular an impact extrusion press punch clamping system (5; 118), comprising a clamping head (6; 111; 211) fastened to* the rant (3; 116; 216) -an adapter (7; 113) and -the punch (2; 103; 203), -wherein the clamping head (6; 111; 211) has a conical flange space (9; 112) to receive the adapter (7; 113) configured as a conical collet (10; 104; 204) and -wherein the collet (10; 104, 204) has a clamping channel (13; 106) to receive a clamping portion (12; 105) of the punch (2; 103; 203), characterised in that -the clamping head (111; 211) comprises a base body (114) and a chuck (115), the chuck (115) having a first bayonet geometry (120), -in that the collet (104; 204), together with the punch (103; 203), forms a clamping unit (102; 202), the collet (104; 204) having a second bayonet geometry (119), -in that the two bayonet geometries (120; 119) are adapted to one another in such a way that they can be coupled to one another by means of an insertion-rotary movement and * can be separated from one another by a rotary-pulling movement, -in that the chuck (115) is guided on the base body (114) and in that the chuck (115) can be moved linearly between a release position (F) and a clamping position (5) relative to the base body (114) while entraining the clamping unit (102; 202) coupled to the chuck (115) by the insertion-rotary movement in such a way -that the collet (104; 204) of the clamping unit (102; 202) is pressed in the clamping position (S) into the flange space (112) of the clamping head (111; 211).
2. clamping system according to claim 1, characterised in that the clamping head (111; 211) comprises at least one force-production means (121), wherein the force-production means (121) is arranged between the base body (114) and the chuck (115) and wherein the force-production means (121) presses the chuck (115) into the clamping position (S) and in that the -clamping head (111; 211) comprises at least one counter-force production means (122), the counter-force production means (122) being arranged between the base body (114) and the chuck (115) and wherein the counter-force production means (122) displaces the chuck (115), upon activation of the counter-force production means (122), against the force of the force-production means (121) into the release position (F).
3. clamping system according to claim 2, characterised in that the force-production means (121) is configured as a spring means.
4. clamping system according to claim 2 or 3, characterised in that the force-production means (121) comprises a pin (124) anchored in the base body (114) of the clamping head (111; 211), a cup spring package (125) guided on the pin (124) and a lock nut (127) screwed onto a free end (126) of the pin (124), wherein the cup spring package (125) is arranged between the lock nut (127) and the chuck (115) also guided on the pin (124) and wherein the counter-force production meahs (122) is arranged between the base body (114) of the clamping head (111; 211) and the chuck (115)
5. Clamping system according to claim 2, characterised in that the counter-force production means (122) is configured as a drive means (131), which can be driven from an energy source, and wherein the counter-force production means (122) in particular comprises a cylinder (132) that can be actuated hydraulically or pneumatically or electrically.
6. Clamping system according to any one of the preceding claims, characterised in that the clamping system (101; 201) comprises a plurality of force-production means (121), the force-production means (121) being arranged around the chuck (115) and force vectors of the force-production means (121) being oriented, in particular, parallel to an insertion direction (x') for the clamping unit (102; 202)
7. Clamping system according to any one of the preceding claims, characterised in that the clamping unit (102; 202) comprises an entrainer (135) and in that the clamping head (111; 211) comprises a stop (136), the entrainer (135) resting on the stop (136)in the clamping position (S).B. Clamping system according to claim 7, characterised in that the clamping head (111; 211) comprises a sensor (250), the sensor (250) detecting the abutment of the entrainer (135) on the stop (136) 9. Clamping system according to any one of the preceding claims, characterised in that the chuck (115) and the collet (104; 204) cooperate in the clamping position (S) in such a way that the collet (104, 204), upon an activation of the counter-force production means (122), is moved from the chuck (115) out of the clamping position (S) counter to the insertion direction (x') and is thus released from the base body (114) of the clamping head (111; 211) 10. Clamping system according to any one of the preceding claims, characterised in that the punch (103; 203) is secured by a retaining ring (107) arranged on the punch (103; 203) and by a clamping ring (109) arranged on the punch (103; 203) on the collet (104; 204) 11. Clamping system according to claim 4, characterised in that the chuck (115) is guided on the base body (114) and the latter has a bore (114a) in which the pin (124) of the force-production means (121) is anchored.12. Clamping system according to any one of the preceding claims, characterised in that the clamping head (111; 211) comprises a pressure piece (133, 233), the pressure piece (133; 233) being arranged in the flange space (112) and being configured in such a way that said pressure piece, when the clamping unit (102; 202) is mounted, opposes the collet (104; 204) without contact and has flat contact with the punch (103 203)