A die exchanging device

Abstract: The present invention relates to a die exchanging device for exchanging die sets (29) between a punch press (1) and a storage (31) unit comprising a transport unit (37) with a plurality of carrying sections (39) for carrying and transferring the die sets between the punch press and the storage unit and a loading device (67) for loading the transport unit with the die sets. The die exchanging device is particularly improved in that the loading device includes a die set charging unit for transferring singular die sets separately from the storage unit to carrying sections and vice versa, so that the punch press can be loaded with any desired combination of tools with an improved efficiency.

Description: The present invention relates to a die exchanging device for exchanging die sets between a punch press and a storage unit, comprising a plurality of carrying sections for horizontally carrying and transferring the die sets between the punch press and the storage unit and means for loading an unloading the die exchanging device with the die sets, the die exchanging device being moveable along an Y-axis. In the prior art, a finite number of die sets are attached in a turret of a turret punch press, and the die sets are exchanged by man power. Sometimes, an automatic die exchanging device is used to discharge die sets attached in the turret and to charge other die sets in the turret for next use. The above mentioned conventional automatic die exchanging device includes a pair of arms, that is, a first arm for discharging die sets from the turret and a second arm for taking other die sets out from a die storage magazine. By the way, in the above mentioned conventional automatic die exchanging device the pair of arms only carry out discharging and taking out of a die set respectively from the turret and the die storage magazine at the same time and only exchanges the die sets. Therefore, it is necessary to exchange die sets several times when some die sets are required for one processing on a workpiece, and this takes much time totally. In addition, it is necessary to move the arms upwards and downwards since heights of the die storage magazine and a die set attached in the punch press for use differ from each other. Due to such movements of the arms, which is complicated, the die exchanging device requires large space and much time for exchanging of the die sets. Furthermore, structure of the device becomes complicated for moving the arms, and, as a result, the exchanging device will cost much and take much time for possible repairing or maintaining. By the way, in a conventional turret punch press with a die exchanging device, for example, a method for positioning and fixing a die set in the turret is generally used by pushing the die set to come into contact with a reference surface disposed on the turret and fixing it by means of a hydraulic pressing device. In the above mentioned positioning and fixing method, the contact of the die set with the reference surface of the turret is surface-to-surface contact, and therefore it is difficult to cause the die set to come into contact with the reference surface uniformly by reason of processing precision. Then an error for positioning arises. Another die exchanging device is known from EP-A-0 138 122. In this known device a cassette magazine is adapted to carry several tools one above the other. The cassette magazine can be moved between a press and a main magazine where cassette magazines can be stored. The cassette magazine has to be moved vertically if a certain tool or die has to be transferred to the press. As there is only one single loader for pushing a die into the press the operation of this known die exchanging device is rather slow. From DE-A-20 44 183 a storage unit is known wherein several tools are carried by a rotatable plate. Each tool can be lifted individually from the plate by a lifter so that it engages with a carrier. The carrier is then rotated into another position where the tool is subsequently pushed into the press by another loading device. Again this apparatus is very slow in changing tools. A die exchanging device according to the opening paragraph is known from DE-A-35 07 220. The press shown there can be loaded with tools from a magazine by means of a carrier. The carrier can be moved along an axis between the press and a magazine and be rotated in a horizontal plane. The carrier comprises two tool receiving portion. For exchanging one tool the carrier has to be rotated by 180°. Thus, the tools can be changed only one by one, so that again the tool exchanging operation is rather slow. It is therefore the object of the present invention to improve the efficiency of the die exchanging procedure in a die exchanging device of the type mentioned above. This technical problem is solved by a die exchanging device according to claim 1. Accordingly the transport unit can be loaded with a desired combination of tools and moving the carrying sections back and forth can be avoided. Preferred embodiments of the present invention are laid down in the dependent claims. Hereinafter the present invention is explained and illustrated in greater detail by means of preferred embodiments thereof in conjunction with the accompanying drawings, wherein: Fig. 1 is a perspective drawing of a die exchanging device according to a preferred embodiment of the present invention. Fig. 2 is a sectional view in a large scale taken on the arrow II in Fig. 1. Fig. 3 is a section view along the line III-III in Fig. 2. Fig. 4 is a sectional view in a large scale taken on the arrow IV in Fig. 2. Fig. 5 is a sectional view taken along the line V-V in Fig. 4. Fig. 6 is a plan of an upper part of a turret shown in Fig. 4. Fig. 7 is a plan of a lower part of the turret shown in Fig. 4. Fig. 8 is a sectional view in a large scale taken on the arrow VIII-VIII in Fig. 2 showing the primary part of a second example of a turret. Fig. 9 is a sectional view along the line IX-IX in Fig. 8. Fig. 10 is a plan of an upper part of a turret shown in Fig. 8. Fig. 11 is a sectional view of a modified part of the second example of the turret. Fig. 12 is a plan of an upper part of a turret shown in Fig. 11. Fig. 13 is a plan of a lower part of the turret shown in Fig. 11. Fig. 14 is a perspective drawing of a die exchanging device according to another embodiment of the present invention. Fig. 15 is a front view in a large scale taken on the arrow XV in Fig. 14. Fig. 16 is a plan of the part of the punch press shown in Fig. 15. Fig. 17 is a left side elevation of the part of the punch press shown in Fig. 15. Fig. 18 is a sectional view in a large scale taken on the arrow XVIII in Fig. 14. Fig. 19 is a sectional view along the line XIX-XIX in Fig. 18. Fig. 20 is a sectional view in a large scale taken on the arrow XX in Fig. 18. Fig. 21 is a sectional view along the line XXI-XXI in Fig. 20. Fig. 22 is a plan of an upper part of a turret shown in Fig. 20. Fig. 23 is a plan of a lower part of the turret shown in Fig. 20. In Fig. 1-7, a die exhanging device of a first embodiment of the present invention is described. In Fig. 1, a turret punch press 1 is provided with a portal frame 3 in which at a central part a turret 9 consisted of an upper portion 5 and a lower portion 7 is supported by the frame 3. A plurality of punches P and dies D are attached in the upper portion 5 and the lower portion 7 of the turret 9 respectively at their circumferential parts. A processing location 11 is disposed in the turret punch press 1. After the turret 9 is rotated so that a die set 29 on the turret 9 is positioned at the processing location 11, a punching process starts on a workpiece W which has been positioned at the processing location 11. The punching is carried out by means of a punch P and a die D. The punch P is pressed by a striker (not shown) which is disposed above the processing location 11 and is actuated by driving means (not shown) disposed on the frame 3. In the turret punch press 1, the turret 9 is located on the center, the workpiece positioning device 21 on the left side, and a die set storage area 27 in the portal frame 3 on the right side which is opposite to the workpiece positioning device 21. The die set storage area 27 includes a die set storage section 31 in which a large number of die sets 29 each consisted of an upper die having an appropriate number of punches and a lower die, are stored being spaced from each other in the directions Y and Z. The die sets 29 can be moved in the die set storage section 31 at least in the direction Z by conventional known means. On the circumferential part of the turret 9 a plurality of die set attaching areas 33 are formed in almost U-shaped cuts for attaching die sets 29 and are spaced from each other appropriately. The turret 9 can be rotated, and each die set attaching area 33 can be positioned at a die exchanging position 35. In front of the die exchanging position 35 and the die set storage section 31, an automatic die exchange device 37 is disposed, which is movable in the direction X and Y and is provided with a plurality of housings 39 or die carrying sections. The number of the die carrying sections or housings 39 is greater by one than the number of the die attaching areas 33 of the turret 9 in Fig. 1. As shown in detail in Figs. 1-3, a plurality of guide rails 43 which extend in a parallel direction Y are disposed on a lower frame 41 of the turret punch press 1, and all the housings 39 are slidably mounted integrally on the guide rails 43 through guide members 45. A ball screw 49 is rotatably supported by bearings 47 mounted on both ends of the lower frame 41, and a nut member 51 fixed to a common bottom plate 39U of the housings 39 is engaged with the ball screw 49. When a driving motor (not shown) is actuated the ball screw rotates, and then the housings 39 moves in the direction Y through the nut member 51. The housings 39 moves smoothly since they are guided by the guide rails 43. A plurality of guide rails 53 spaced appropriately and extended in a parallel direction X are disposed on the bottom plate 39U of the housings 39, and a plurality of X-axis carriages 57 are mounted on the guide rails 53 through guide members 55. A X-axis cylinder 61 is mounted on a side wall 39F (Fig. 2) for each housing 39, and an end of a piston rod 63 disposed in the cylinder 61 is attached to an end wall of the X-axis carriage at an upper part. When the piston rod 63 of the X-axis cylinder 61 is actuated the X-axis carriage 57 moves in the direction X. The X-axis carriage 57 moves smoothly since it is guided by the guide rails 53. Each housing 39 is provided with an engagement releasing device 65, while the X-axis carriage is provided with a die holding section 67 for holding the die set 29. The engagement releasing device 65 includes engaging members 71P and 71D which are disposed beside the housing 39 through guiding members 69, and which are connected at one end by a connecting member 73 as shown in Fig. 2. The engagement releasing device 65 is provided with an engagement releasing cylinder 75 on the wall 39F of the housing 39, and a piston rod 77 is disposed in the engagement releasing cylinder 75. An end of the piston rod 77 is connected to the connecting member 73. When the piston rod 77 of the cylinder 75 is actuated the engaging members 71P, 71D connected to the connecting member 73 move in the direction X. The engaging members 71P, 71D are guided along the guiding members 69 when move. The die holding section 67 includes two holding bars 79 which are mounted on the X-axis carriage 57, and to top ends of which chuck devices 81P, 81D are attached as shown in Figs. 2 and 3. The holding bars 79 are connected integrally to two connecting bars 83 respectively which extend in the direction X. The connecting bars 83 are connected with each other at one end by a connecting member 85. The X-axis carriage 57 is provided with a holding cylinder 87 in which a piston rod 89 is attached, and a top end of the piston rod 89 is fixed to the connecting member 89. When the piston rod 89 of the cylinder 87 is actuated the chuck devices 81P, 81D move in the direction X through the connecting member 85 and the connecting bars 83. A die set 29 is attached in the die set attaching area 33 in an exchangeable manner. As shown in detail in Fig. 2 and Figs. 4 to 7, a U-shaped cut 5V is formed in the upper portion 5 of the turret 9 as the die attaching area 33, for attaching a die base or die holder 91 holding, for example, two punches P. The die base 91 is charged from and discharged to the right side (Fig. 6). Structure for holding the punches P in the die base 91 is not described here since it is known. In the die base 91 engaging members 95 with engaging portions 93 are disposed (Fig. 5, on the right and left of an upper part), while pins 97 as engaging members which engage with the engaging members 95 are disposed to slide vertically in the upper portion 5 of the turret 9. At a lower part of the each engaging pin 97 in the upper portion 5 of the turret 9 there is formed a cut 5C in which an L-shaped supporting block 99 is disposed and fixed to the upper portion 5 with bolts. A hole is formed vertically through the supporting block 99, and a screwed bar 101 is inserted in the hole. And an end of the screwed bar 101 is fixed to the engaging pin 97, and another end is fixed integrally to a supporting block 105 which supports a cam follower 103 in a rotatable manner. A spring 107 is disposed between the engaging pin 97 and the supporting block 99. The spring 107 is normally energized to press the engaging pin 97 upwards. The die base 91 and the upper portion 5 are designed so that the engaging pins 97 of the upper portion 5 of the turret 9 engage with the engaging members 95 of the die base 91 by means of the energized springs 107 when the die base 91 is charged and positioned. Therefore, positioning of the die base 91 is carried out precisely in the upper portion 5 of the turret 9 in the die attaching area 33. As shown in Figs. 5 and 6 a pair of holding members 109 are attached with bolts 111 to a top surface of the upper portion 5 of the turret 9 at both sides of the cut 5V for holding the die base 91 within the cut 5V. For protecting the die base 91 not to be damaged when it is charged in the die attaching area 33, an elastic member 113 made of gum or other material is fixed by means of bolts 115 under the each holding member 109 at an end portion of the holding member 109, which is an entrance of the die attaching area 33 for the die base 91. In addition, an L-shaped holding member 117 is attached with bolt 121 through a bracket 119 to the upper portion 5 near a front end of the cut 5V as shown in Fig. 4 and 6 for holding the die base 91 within the cut 5V. In the lower portion 7 of the turret 9 a U-shaped cut 7V is formed as the die attaching area 33 for attaching a die base or die holder 227 holding two dies D. The die base 227 is charged from and discharged to the right side (Fig. 7). Structure for holding the dies D in the die base 227 is not described here since it is known. In the die base 227 engaging members 127 with engaging portions 125 are disposed (Fig. 5, on the right and left of a lower part), while pins 129 as engaging members which engage with the engaging members 127 are disposed to slide vertically in a supporting member 235 fixed to the lower portion 7 of the turret 9. At a lower part of the each engaging pin 129 in the lower portion 7 of the turret 9 there is formed a cut 7C in which an L-shaped supporting block 133 is disposed and fixed to the supporting member 235 with bolts. A hole is formed vertically through the supporting block 133, and a screwed bar 135 is inserted in the hole. An end of the screwed bar 135 is fixed to the engaging pin 129, and another end is fixed integrally to a supporting block 139 which supports a cam follower 137 in a rotatable manner. A spring 141 is disposed between the engaging pin 129 and the supporting block 133. The spring 141 is normally energized to press the engaging pin 129 upwards. The die base 227 and the lower portion 7 are so designed that the engaging pins 129 of the lower portion 7 of the turret 9 engage with the engaging members 127 of the die base 227 by means of the energized springs 141 when the die base 227 is charged and positioned. Therefore, positioning of the die base 227 is carried out precisely at the die attaching area 33 of the lower portion 7 of the turret 9. As shown in Figs. 5 and 7 a pair of holding members 247 are attached with bolts 249 to the supporting member 235 at both sides of the cut 7V for holding the die base 227 within the cut 7V. For protecting the die base 227 not to be damaged when it is charged in the cut 7V of the die attaching area 33, an elastic member 251 made of gum or other material is fixed by means of bolts 149 under the each holding member 247 at an end portion of the holding member 247, which is an entrance of the die attaching area 33 for the die base 227. As shown in Fig. 4, when the engaging members 71P, 71D of the engagement releasing device 65 are moved to the turret 9, inclined parts of ends of the engaging members 71P, 71D contact and press down the cam followers 103, 137, and then the engaging pins 97, 129 come down through the supporting blocks 105, 139 and the screwed bars 101, 135 against force of the springs 107, 141. Therefore, the pins 97, 129 disengage from the engaging members 95, 127, and then the die bases 91, 227 become free from the upper portion 5 and the supporting member 235 of the lower portion 7 respectively, that is, ready to be discharged from the die set attaching area 33. Then, the chuck devices 81P, 81D are moved to the turret 9 and inserted in holes 255, 257 formed in the die bases 91, 227. When the chuck devices 81P, 81D, which are for example known collet chucks, are inserted in the holes 255, 257, the die bases 91, 227 are held automatically with the chuck devices 81P, 81D. Now, an operation for exchanging all die sets (two sets for this example) attached in the die set attaching areas 33 of the turret 9 is explained. The operation includes taking out the new die sets 29 from the die set storage section 31 and charging the die sets 29 into all the die set attaching areas 33 when each area 33 is at the die exchanging position 35 and discharging die sets from each area 33 at the die exchanging position 35 and storing the die sets taken out from each area 33 in the die set storage section 31. First, all the housings 39, each of which is now empty, are moved in the direction Y until they come in front of the die set storage section 31. Then, the X-axis cylinders 61 for two housings of the three are actuated to move the X-axis carriages 57 towards the die set storage section 31, and the holding cylinders 87 are actuated for the two to move the chuck devices 81P, 81D forwards in the direction X until the chuck devices are inserted in the holding holes 255, 257 of die bases 91, 227 of two die sets 29 which are arranged in the storage section 31 at a same height of the die set attaching area 33 at the die exchanging position 35. By the action of the cylinders 61, 87, two housings 39 of the three hold two die sets. Then, all the housings 39 are moved in the direction Y towards the turret 9 so that an empty housing 39 stands at the die exchanging position 35. The X-axis cylinder 61 is then actuated to move the X-axis carriage 61 for the empty housing 39 until the carriage 61 comes near the turret 9. Next, the engagement releasing cylinder 75 is actuated to enable the engaging members 71P, 71D to press down the cam follower 103, 137, and therefore a die set 29 which is engaged with the turret 9 is disengaged from it as described in the above. After it, the holding cylinder 87 is actuated until the chuck devices 81P, 81D come in the holes 255, 257 formed in the die bases 91, 227 to hold the die bases 91, 227, and then the die set 29 is discharged from the turret 9 by actuating the cylinder 87. The engagement releasing cylinder 75 and the X-axis cylinder 61 are then actuated to withdraw the engaging members 71P, 71D and the X-axis carriage 57 respectively away from the turret 9. The engaging pins 97, 129 are raised by action of the energized springs 107, 141 as the engaging members 71P, 71D have been withdrawn from the turret 9. Next, housings 39 are moved a little in the direction Y so that one of housings 39 which holds a die set 29 taken out from die set storage section 31 is located at the die exchanging position 35, and the engagement releasing cylinder 75 is actuated to press down the cam follower 103, 137, while the X-axis carriage 57 is moved forwards to charge the die set 29 into the die attaching area 33 which is at the die exchanging position 35. Then, the holding cylinder 87 is operated to withdraw the chuck devices 81P, 81D from the holding holes 255, 257, while the engagement releasing cylinder 75 is operated to withdraw the engaging members 71P, 71D. Therefore, the engaging pins 97, 129 engage with the engaging portions 93, 125 of the engaging members 95, 127 by action of the springs 107, 141, and the die set 29 is set in the die attaching area 33. By operating the automatic die exchanging device, another die set 29 in a die attaching area 33 is discharged from the turret 9 after the die attaching area 33 is located at the die exchanging position 35 by rotating the turret 9, and another die set 29 taken out from the die set storage section 31 is set in the die attaching area 33 in the same way mentioned above. By the above operation, exchanging of all die sets 29 on the turret 9 is completed. Then, two die sets 29 discharged from the turret 9 are stored in the die set storage section 31, if necessary. When exchanging of only one of two die sets is required, a housing 39 is used to take out one die set from the die set storage section 31, and an empty housing is used to discharge a die set to be exchanged from the turret 9. As mentioned above, all the die sets 29 on the turret 9 are exchanged only by the movement of the die exchanging device 37 from the die set storage section 31 to the turret 9, and therefore it is possible to shorten time for exchanging the dies . Furthermore, as an moving area of the die exchanging device 37 overlaps a part of a moving area of the workpiece positioning device 21 in the direction Y, width of the turret punch press 1 can be smaller than a conventional press. In addition, as the die exchanging device 37 is provided with a plurality of housings 39 to exchange a plurality of die sets 29 at a time, it is possible to shorten time for exchanging some die sets required for a processing. Furthermore the die bases are charged into and discharged from the upper and the lower portions of the turret horizontally by the die exchanging device, therefore exchanging of die sets will be carried out with ease even if a space between the upper portion and the lower portion is small in a vertical direction. Not limiting the embodiment described above, any modification is carried out for the embodiment within the scope of this invention. The press can be, for example, provided with more than three die attaching areas and the housings. The die set storage area 27 may be disposed outside the press instead of in the portal frame 3 of the press. Furthermore, the engaging pins 97, 129 may be rotated for engaging with the engaging members 95, 127 instead of moving vertically. In the following, the exchanging process of the die sets between the transport unit and a turret 9 according to a second embodiment thereof will be described. In Figs. 8 to 10, the die base 91 attached in the upper portion 5 of of the turret 9 is shown. The die base 91 is provided with engaging members 95 having conical engaging parts 93. In the upper portion 5 of the turret 9, two engaging members or pins 97 are slidably disposed for engaging with the engaging parts 93 of the engaging members 95 of the die base 91, and also a cut 5C is formed at a lower part of the each engaging pin 97. An L-shaped supporting block 99 is disposed in the each cut 5C and is fixed to the upper portion 5 by means of bolts. A hole is formed vertically through the supporting block 99, and a screwed bar 201 is inserted in the hole. An end of the screwed bar 201 is fixed to the engaging pin 97, and another end is fixed integrally to a supporting block 205 which supports a cam follower 203 in a rotatable manner. A spring 207 is disposed between the engaging pin 97 and the supporting block 99. The spring 207 is normally energized to press the engaging pin 97 upwards. A fixing member 209 is mounted on the upper portion 5 for pressing down the die base 91 not to come upwards out of the attaching area 33. The fixing member 209 is U-shaped as shown in Fig. 10, and is supported by pins 211 which are inserted in levers 209a of the member 209 and which are supported by bearings 213 fixed to the portion 5 of the turret 9, so that the member 209 rotates free around the pin 211. A base 209b of the fixing member 209 is attached to the portion 5 with two bolts 217 embedded in the portion 5, and is normally pressed upwards by action of tension springs 219 disposed around the bolts 217 between the base 209b and the portion 5. Therefore, round lower surfaces 215 formed at front ends of the fixing member 209 press down the die base 91. On the other hand, a driving member 223 is supported from the portal frame 3 through a bracket 221 for pressing down the base 209b of the fixing member 209. The driving member 223 is, for example, a pneumatic cylinder provided with a piston rod 225. When the cylinder or driving member 223 is actuated, the piston rod or pressing member 225 extrudes and press a central part of the base 209b of the fixing member 209 against the spring force. Therefore, the levers 209a rotate counterclockwise around the pins 211, and the round lower surfaces 215 rise apart from an upper surface of the die base 91. When the fixing member 209 is in this state, the die 91 is charged or discharged from the upper portion 5 of the turret 5. When the cylinder 223 is actuated to withdraw the piston rod 225 from the base 209b, the fixing member 209 rotates clockwise by the action of the spring 219 and press down the die base 91 to fix it securely to the portion 5. In the lower portion 7 of the turret 9 in the die attaching area 33, a U-shaped cut 7V is formed for attaching a die base or die holder 227 holding two dies D (Fig. 2). The die base 227 is charged from and discharged to the right side (Fig. 7). As shown in Figs. 8 and 9, engaging members 231 with engaging portions 229 are disposed in the die base 227, while engaging pins or members 233 for engaging with the engaging members 231 are disposed to slide vertically in a supporting member 235 fixed to the lower portion 7 of the turret 9. At a lower part of the each engaging pin 233 in the lower portion 7 of the turret 9 there is formed a cut 7C in which an L-shaped supporting block 237 is disposed and fixed to the supporting member 235 with bolts. A hole is formed vertically through the supporting block 237, and a screwed bar 239 is inserted in the hole. An end of the screwed bar 239 is fixed to the engaging pin 233, and another end is fixed integrally to a supporting block 243 which supports a cam follower 241 in a rotatable manner. A spring 245 is disposed between the engaging pin 233 and the supporting block 237. The spring 245 is normally energized to press the engaging pin 233 upwards. The die base 227 and the lower portion 7 are so designed that the engaging pin 233 of the lower portion 7 of the turret 9 engages with the engaging member 231 of the die base 227 by means of the energized spring 141 when the die base 227 is charged and positioned. Therefore, positioning of the die base 227 is carried out precisely in the lower portion 7 of the turret 9 in the die attaching area 33. As shown in Figs. 7 and 9, a pair of holding members 247 are attached with bolts 249 to the supporting member 235 at both sides of the cut 7V for holding the die base 227 within the cut 7V. For protecting the die base 227 not to be damaged when it is charged in the cut 7V of the die attaching area 33, an elastic member 251 made of gum or other material is fixed by means of bolts 253 under the each holding member 247 at an end portion of the holding member 247, which is an entrance of the die attaching area 33 for the die base 227. As shown in Fig. 8, when the engaging members 71P, 71D of the engagement releasing device 65 are moved to the turret 9, inclined parts of ends of the engaging members 71P, 71D contact and press down cam followers 203, 241, and the engaging pins 97, 233 come down through the supporting blocks 205, 243 and screwed bars 201, 239 against force of the springs 207, 245. Therefore, the pins 97, 233 disengage from the engaging members 95, 231, and then the die bases 91, 227 become free from the upper portion 5 and the supporting member 235 of the lower portion 7 respectively, that is, ready to be discharged from the die set attaching area 33. Then, the chuck devices 81P, 81D are moved to the turret 9 and inserted in the holes 255, 257 formed in the die bases 91, 227 (Fig.2). When the chuck devices 81P, 81D, are inserted in the holes 255, 257, the die bases 91, 227 are held automatically with the chuck devices 81P, 81D as mentioned in the above. An operation for exchanging all the die sets will be carried out as described in the above. However, a different point from the first embodiment is that the fixing member 209 is used during the operation. When a die set 29 is charged or discharged from the turret 9, the driving member 223 is activated to press down the base 209b of the fixing member 209 so that the contact surfaces 215 of the fixing member 209 to be raised. The fixing member 209 is used to press down the die set 29 after the die set 29 has been charged in the turret 9. In Figs. 11 to 13, a modified example for the second embodiment is shown, in which the same reference numerals is used for the same elements, and description is omitted for them. For this modified example, pressing elements for pressing down the die bases 91, 227 in the upper and lower portions 5, 7 are different from the example shown in Figs. 7 to 10. Elements for pressing a die base 91 attached in the upper portion 5 of the turret 9 are pressing members 259 which are disposed on a supporting block 261 mounted on the upper portion 5. An engaging member 263 is inserted in each supporting block 261. A screwed bar 265 is inserted and fixed in the engaging member 263, and an upper end of the screwed bar 265 is integrally fixed to a supporting block 205 by which a cam follower 203 is supported rotatably. A spring 207 is disposed between the engaging member 263 and the supporting block 261 so that the engaging member 263 is normally pressed downwards by the spring 207. Elements for pressing a die base 227 attached in the lower portion 7 of the turret 9 are pressing members 267 which are fixed to the supporting member 235 of the lower portion 7 by means of bolts, etc. An engaging member 269 slidable to the right and the left (Fig. 11) is disposed in each pressing member 267 as a fixing member for fixing the die base 227 in the portion 7. On a part of a bottom of the engaging member 269 an inclined surface is formed for sliding in contact with an inclined surface formed on the die base 227. A guide bar 277 for guiding the engaging member 269 is fixed to a base plate 275 which is formed integrally in the pressing member 267. A coil spring 279 is disposed around the guide bar 277 and between the engaging member 269 and the base plate 275, and is normally energized to press the engaging member 269 towards the left side for pressing down the die base 227. The pressing member 267 is provided with a step 281 at which the engaging member 269 stops and with a hole in which the engaging member 71D of the engagement releasing device 65 is to be inserted. When inclined parts of front ends of engaging members 71P, 71D of a engagement releasing device 65 (not shown) come into contact with and raise the cam followers 203, 241, and when inclined parts of front ends of other engaging members 71D of the engagement releasing device 65 move into the holes 283 and come into contact with and press the engaging members 269 towards the right side, the die bases 91, 227 are disengaged from the portions 5, 7. As mentioned above, fixing releasing elements such as engagement releasing device 65 and the driving member 223 are disposed outside the turret 9, and only fixing elements such as the engaging or fixing members 209, 263, 269 and pins 97, 129, 233 and springs 107, 207, 141, 219, 279, which are relatively small, light, and of simple structure, are mounted on the turret 9 in the turret punch press of the second embodiment So, the turret 9 can be of compact size and simple structure, and therefore it does not require large space, and is manufactured in low cost and easy to maintain. In addition, positioning of die bases is carried out with ease and precisely due to the conical engaging parts 93, 229. In Fig. 14-23, a die exchanging device according to another embodiment of the present invention are described. In Fig. 14 a turret punch press 301 is provided with a portal frame 303 in which at the central part a turret 309 consisted of an upper portion 305 and a lower portion 307 is supported by the frame 303. A plurality of die sets 329 are to be attached in the turret 309 at die set attaching areas 333 which are formed at a circumferential part of the turret 309. A processing location 311 is disposed in the turret punch press 301. After the turret 309 is rotated so that a die set 329 on the turret 309 is positioned at the processing location 311, a punching process starts on a workpiece W which has been positioned at the processing location 311. The punching is carried out by means of a punch P and a die D. The punch P is pressed by a striker (not shown) which is disposed above the processing location 311 and is actuated by driving means (not shown) disposed on the frame 303. In the turret punch press 301, the turret 309 is located on the center, the workpiece positioning device 321 on the left side, and a die set storage area 327 in the portal frame 303 on the right side which is opposite to the workpiece positioning device 321. The die set storage area 327 includes a die set storage section 331 in which a large number of die sets 329 each consisted of an upper die having an appropriate number of punches and a lower die, are stored and spaced from each other in the directions Y and Z. The die sets 329 can be moved in the storage section 331 at least in the direction Z by conventional known means. A plurality of die set attaching areas 333 are formed in almost U-shaped cuts on the circumferential part of the turret 309 for attaching die sets 329. The die set attaching areas 333 are spaced from each other appropriately and opposed to each other. The turret 309 can be rotated, so that each die set attaching area 333 can be positioned at a die exchanging position 335. In front of the die exchanging position 335 and the die set storage section 331, a die exchange device 337 is disposed, which is movable in the direction X and Y and is provided with a plurality of housings 339 or die carrying sections. The number of the die carrying sections or housings 339 is four and is greater by one than the number of the die attaching areas 333 of the turret 309 for this example shown in Fig. 14. The die exchanging device 337 is also provided with die carrying means 343 which include a plate 341 supported by a support (not shown) and two guide rails 345 mounted on the plate 341 and spaced from each other. The plate 341 and the guide rails 345 extend in a direction Y. All the housing 339 are integrally mounted on the guide rails 341 through guide members 351 (not shown in Fig. 14). A ball screw 347 is mounted on the plate 341 and between the two guide rails 345 for moving the housing 339 horizontally. In Figs. 15 to 17, details about the die carrying means 343 are described. The plate 341 is supported by a support through a bracket 359 as shown in Fig. 17. The guide rails 345 on the plate 341 are engaged with guide members 351 such as LM guides, etc. fixed to a bracket 349 which supports the housing 339. The ball screw 347 is supported in a rotatable manner by bearings 353 disposed on the plate 341 as shown in Fig. 15. A screwed nut engages with the ball screw 347 and joints entire housings 339 and the supporting bracket 349. A motor 357 is disposed at an end of the ball screw 347 for driving it. When the driving motor 357 is actuated, the ball screw 347 rotates, and then the housings 339 moves in the direction Y through the nut member 355. The housings 339 moves smoothly since they are guided by the guide rails 345. In Fig. 15, three positions where the housings 339 stand is shown. At the left position die sets are charged into and discharged from the turret 309 for exchanging the die sets, at the middle position the housings 339 stand waiting for next action, and at the right position die sets are taken out from and stored in the die set storage section 331. When die sets are used from the storage section 331, the housings 339 of the die exchanging device 337 are located at the right position in front of the storage section 331, and some die sets are taken out and held in the housings, and then the housings wait at the middle position until they receive an order for exchanging the die sets. If the housings receive the order, they move to the die exchanging position 335, and the die sets are exchanged by the die exchange device 337. In Figs. 18 to 23, description about the die exchanging device 337 of the present invention is made in detail. The guide members 351 are spaced and disposed on a front plate 349a of the supporting bracket 349, and are engaged in a slidable manner with the guide rails 345 which are fixed to a plate 341 mounted on the bracket 359. The ball screw 347 is supported in a rotatable manner by the bearings 353 mounted on the plate 341 at both ends of it, and is also engaged with a nut 355 fixed to the front plate 349a of the supporting bracket 349. A plurality of guide bars 361 extended in the direction X are disposed in the housing 339. A X-axis carriage 365 is mounted on the guide bars 361 through a plurality of bushings 363. A rodless cylinder 367 is fixed to the housing 339 by fixing both ends of a cylinder part 369 of the rodless cylinder 367 to the housing 339 with rock nuts 371. A driving portion 373 for driving the cylinder 367 is attached to the X-axis carriage 365. When the rodless cylinder 367 is actuated, the X-axis carriage 365 moves in the direction X through the driving portion 373. The X-axis carriage 365 moves smoothly since it is guided by the guide bars 361. Each housing 339 is provided with an engagement releasing device 374, while the X-axis carriage 365 is provided with a die holding section 375 for holding the die set 329. The engagement releasing device 374 includes engaging members 379P and 379D which are disposed beside the housing 339 through guiding members 377, and which are connected at one end by a connecting member 381 as shown in Figs. 18 and 19. The engagement releasing device 374 is provided with an engagement releasing cylinder 385 disposed in a rotatable manner on the front plate 349a of the supporting bracket 349 through a hinged block 383, and a piston rod 387 is disposed in the engagement releasing cylinder 387. A joint 389 is disposed for connecting an end of the piston rod 387 and an end of the link 391. The link 391 is hinged at the end in the joint 389, at the middle supported in a rotatable manner by an axis 393 mounted on the housing, and is at the other end engaged with a pin 395 mounted on the connecting member 381. When the engagement releasing cylinder 385 is actuated to extend or withdraw the piston rod 387, the link 391 rotates anticlockwise or clockwise around the axis 393, and the engaging members 379P, 379D connected to the connecting member 381 move in the direction X. The engaging members 379P, 379D are guided when move by the guiding members 377 disposed along each housing 339. The die holding section 375 includes two holding bars 397 which are mounted on the X-axis carriage 365, and to front ends of which chuck devices 399P, 399D are attached as shown in Figs. 18 and 19. The holding bars 397 are connected integrally to two holding cylinders 401 respectively which are attached to the X-axis carriage 365. Piston rods 403 of the holding cylinders 401 penetrate the holding bars 397, and to ends of the piston rods 403 the chuck devices 399P, 399D are attached. The piston rods 403 are normally pressed to withdraw (to the right, in Fig. 18) by action of springs 405 disposed in the holding bars 397. The structure of the chuck devices 399P, 399D is that of a collet chuck. When the holding cylinder 401 is actuated, the chuck devices 399P, 399D attached to the cylinder rods 403 move in the direction X. A die set 329 is attached in the die set attaching area 333 in an exchangeable manner. As shown in detail in Figs. 18 to 23, a U-shaped cut 5V is formed in the upper portion 305 of the turret 309 as the die attaching area 333 for attaching a die base or die holder 407 holding an appropriate number of punches P (for example, two or three as shown in Fig. 18). The die base 407 is charged from and discharged to the right side (Fig. 6). In the die base 407 engaging members 411 with engaging portions 409 are disposed (Fig. 21, on the right and left of an upper part), while pins 413 as engaging members which engage with the engaging members 411 are disposed to slide vertically in the upper portion 305 of the turret 309. At a lower part of the each engaging pin 413 in the upper portion 305 of the turret 309 there is formed a cut 5C in which an L-shaped supporting block 415 is disposed and fixed to the upper portion 305 with bolts. A hole is formed vertically through the supporting block 415, and a screwed bar 417 is inserted in the hole. And an end of the screwed bar 417 is fixed to the engaging pin 413, and another end is fixed integrally to a supporting block 421 which supports a cam follower 419 in a rotatable manner. A spring 423 is disposed between the engaging pin 413 and the supporting block 415. The spring 423 is normally energized to press the engaging pin 413 upwards. The die base 407 and the upper portion 305 are designed so that the engaging pins 413 of the upper portion 305 of the turret 309 engage with the engaging members 411 of the die base 407 by means of the energized springs 423 when the die base 407 is charged and positioned. Therefore, positioning of the die base 407 is carried out precisely at the die attaching area 333 of the upper portion 305 of the turret 309. As shown in Figs. 20 to 22, a pair of holding members 425 are attached with bolts 427 to a top surface of the upper portion 305 of the turret 309 at both sides of the cut 5V for holding the die base 407 within the cut 5V. For protecting the die base 407 not to be damaged when it is charged in the die attaching area 333, an elastic member 429 made of gum or other material is fixed by means of bolts 431 under the each holding member 425 at an end portion of the holding member 425, which is an entrance of the die attaching area 333 for the die base 407. In addition, an L-shaped holding member 433 is attached with bolt 121 through a bracket 435 to the upper portion 305 near a front end of the cut 5V as shown in Fig. 20 and 22 for holding the die base 407 within the cut 5V. In the lower portion 307 of the turret 309 a U-shaped cut 7V is formed as the die attaching area 333 for attaching a die base or die holder 439 holding two dies D. The die base 439 is charged from and discharged to the right side (Fig. 7). In the die base 439 engaging members 443 with engaging portions 441 are disposed (Fig. 21 on the right and left of a lower part), while pins 445 as engaging members which engage with the engaging members 443 are disposed to slide vertically in a supporting member 447 fixed to the lower portion 307 of the turret 309. At a lower part of the each engaging pin 445 in the lower portion 307 of the turret 309 there is formed a cut 7C in which an L-shaped supporting block 449 is disposed and fixed to the supporting member 447 with bolts. A hole is formed vertically through the supporting block 449, and a screwed bar 451 is inserted in the hole. An end of the screwed bar 451 is fixed to the engaging pin 445, and another end is fixed integrally to a supporting block 455 which supports a cam follower 453 in a rotatable manner. A spring 457 is disposed between the engaging pin 445 and the supporting block 449. The spring 457 is normally energized to press the engaging pin 445 upwards. The die base 439 and the lower portion 307 are so designed that the engaging pins 445 of the lower portion 307 of the turret 309 engage with the engaging members 443 of the die base 439 by means of the energized springs 457 when the die base 439 is charged and positioned. Therefore, positioning of the die base 439 is carried out precisely at the die attaching area 333 of the lower portion 307 of the turret 309. As shown in Figs. 21 and 23, a pair of holding members 459 are attached with bolts 461 to the supporting member 447 at both sides of the cut 7V for holding the die base 439 within the cut 7V. For protecting the die base 439 not to be damaged when it is charged in the cut 7V of the die attaching area 333, an elastic member 463 made of gum or other material is fixed by means of bolts 465 under the each holding member 459 at an end portion of the holding member 459, which is an entrance of the die attaching area 333 for the die base 439. As shown in Fig. 20, when the engaging members 379P, 379D of the engagement releasing device 374 are moved to the turret 309, inclined parts of ends of the engaging members 379P, 379D contact and press down the cam followers 419, 453, and then the engaging pins 413, 445 come down through the supporting blocks 421, 455 and the screwed bars 417, 451 against force of the springs 423, 457. Therefore, the pins 413, 445 disengage from the engaging members 411, 443, and then the die bases 407, 439 become free from the upper portion 305 and the supporting member 447 of the lower portion 307 respectively, that is, ready to be discharged from the die set attaching area 333. Then, the chuck devices 399P, 399D are moved to the turret 309 and inserted in holes 467, 469 formed in the die bases 407, 439. When the chuck devices 399P, 399D, which are for example known collect chucks, are inserted in the holes 467, 469, the die bases 407, 439 are held automatically with the chuck devices 399P, 399D. Now, an operation for exchanging die sets by means of the die exchanging device 337 is explained. The operation includes taking out the new die sets 329 from the die set storage section 331 and charging the die sets 329 into all the die set attaching areas 333 when each area 333 is at the die exchanging position 335 and discharging die sets from each area 333 at the die exchanging position 335 and storing the die sets taken out from each area 333 in the die set storage section 331. First, all the housings 339, each of which is now empty, are moved in the direction Y until they come to a desired position in front of the die set storage section 331. Then, the rodless cylinders 367 for three housings of the four are actuated to move the X-axis carriages 365 towards the die set storage section 331, and the holding cylinders 401 are actuated for the three to move the chuck devices 399P, 399D forwards in the direction X until the chuck devices are inserted in the holding holes 467, 469 of die bases 407, 439 of three die sets 329 which are arranged in the storage section 331 at a same height of the die set attaching area 333 which is at the die exchanging position 335. By the action of the cylinders 367, 401, three housings 339 of the four hold three die sets. Then, all the housings 339 are moved in the direction Y towards the turret 309 so that an empty housing 339 stands at the die exchanging position 335. The rodless cylinder 367 is then actuated to move the X-axis carriage 367 for the empty housing 339 until the carriage 367 comes near the turret 309. Next, the engagement releasing cylinder 385 is actuated to enable the engaging members 379P, 379D to press down the cam follower 419, 453, and therefore a die set 329 which is engaged with the turret 309 is disengaged from it as described in the above. After it, the holding cylinder 401 is actuated until the chuck devices 399P, 399D come in the holes 467, 469 formed in the die bases 407, 439 to hold the die bases 407, 439, and then the die set 329 is discharged from the turret 309 by actuating the cylinder 401. The engagement releasing cylinder 385 and the rodless cylinder 367 are then actuated to withdraw the engaging members 379P, 379D and the X-axis carriage 365 respectively away from the turret 309. The engaging pins 413, 445 are raised by action of the energized springs 423, 457 as the engaging members 379P, 379D have been withdrawn from the turret 309. Next, housings 339 are moved a little in the direction Y so that one of housings 339 which holds a die set 329 taken out from die set storage section 331 is located at the die exchanging position 335, and the engagement releasing cylinder 385 is actuated to press down the cam follower 419, 453, while the X-axis carriage 365 is moved forwards to charge the die set 329 into the die attaching area 333 which is at the die exchanging position 335. Then, the holding cylinder 401 is operated to withdraw the chuck devices 399P, 399D from the holding holes 467, 469, while the engagement releasing cylinder 385 is operated to withdraw the engaging members 379P, 379D. Therefore, the engaging pins 413, 445 engage with the engaging portions 409, 441 of the engaging members 411, 443 by action of the springs 423, 457, and the die set 329 is set in the die attaching area 333. By using the the housing which has just become empty, another die set 329 in a die attaching area 333 is discharged after the die attaching area 333 has been located at the die exchanging position 335 by rotating the turret 309, and another die set 329 held in another housing will beset in the die attaching area 333 which has now become empty. By the above operation, exchanging of all die sets 329 on the turret 309 is completed. Then, three die sets 329 discharged from the turret 309 are stored in the die set storage section 331, if necessary. When exchanging of only one or two of three die sets is required, one or two housings 339 are used to take out one or two die sets from the die set storage section 331, and an empty housing is used to discharge a die set to be exchanged from the turret 309. As mentioned above, all the die sets 329 on the turret 309 are exchanged quickly by the die exchanging device 337 which moves only on a plane horizontally at the height of the die attaching area 333 which is at the die exchanging position 335. Not limiting the embodiment described above, any modifications are applied for the embodiment within the scope of this invention as defined by the claims.

Claims: Die exchanging device for exchanging die sets (29; 329) between a punch press (1; 301) and a storage unit (31; 331), said die exchanging device comprising: a plurality of die carrying sections (39; 339) for horizontally carrying and transferring die sets (29; 329) between the punch press (1; 301) and the storage unit (31; 331), and means for loading and unloading (57, 67; 365, 375) the die exchanging device (37; 337) with die sets (29; 329), the die exchanging device (37; 337) being movable along an Y-axis, characterised in that said means for loading and unloading (57, 67; 365, 375) being adapted to move die sets (29; 329) to and from said die exchanging device (37; 337) along an X-axis which is substantially perpendicular to said Y-axis, said means for loading and unloading being provided on said die exchanging device (37; 337) for each die carrying section (39; 339) to transfer die sets (29; 329) individually to and from said die carrying sections (39; 339). Die exchanging device as claimed in claim 1, characterised in that a first driving means (49,357,347) is provided for moving the carrying sections (39,339) along said Y-axis and a second driving means (61,367) is provided for moving the carrying sections (39,339) or at least portions (57,365) thereof independently of each other along said X-axis. Die exchanging device as claimed in claim 1 or 2, characterised in that each of the carrying sections (39,339) is provided with a die holding section (67,375) for releasably gripping and holding a die set (39,339). Die exchanging device according to claim 3, characterised in that the means for loading and unloading includes a plurality of X-axis carriages (57;365), each X-axis carriage being provided with a die holding section (67;375) and being movable independently of the other X-axis carriages along the X-axis. Die exchanging device as claimed in claim 3 or 4, characterised in that the die holding section (67,375) comprises at least one holding bar (79,397) with a chuck device (399P,399D,81P,81D) mounted thereon for gripping the die set (39,339) and an actuating means (87,401,403) for moving said holding bar (79,397) and actuating said chuck device (399P,399D,81P,81D). Die exchanging device as claimed in at least one of claims 1 to 5, characterised in that the carrying sections (39,339) are connected to a common bottom plate (39U) which is movably supported on guide rails (43,345) extending along said Y-axis. Die exchanging device as claimed in claim 6, characterised in that each of the X-axis carriages (57,365) is slideably supported on guide rails (53,361) which are provided on the bottom plate (39U) and extend along said X-axis. Die exchanging device as claimed in at least one of claims 2 to 7, characterised in that the first driving means are formed by a screw spindle device (49,47,347,353) for moving the common bottom plate (39U) along said Y-axis. Die exchanging device as claimed in at least one of the claims 2 to 8, characterised in that the second driving means is formed by a cylinder unit (61,367) associated with each carrying section (39,339) for moving the carriage (57,365) thereof in the direction of said X-axis. Die exchanging device as claimed in at least one of claims 2 to 9, characterised in that the X-axis and the Y-axis of movement of the carrying sections (39,57,339,365) are disposed in a common horizontal plane. Die exchanging device as claimed in at least one of claims 1 to 10, characterised in that each of the carrying sections (39,339) is provided with an engagement releasing device (65,374) for releasing the engagement of the die set (39,339) and punch press (1,301). Die exchanging device as claimed in claim 11, characterised in that the engagement releasing device (65,374) comprises engaging members (379P,379D,81P,81D) having a cam surface for disengaging locking members of the punch press (1,301) for locking the die sets (29,329) and an actuating unit (385) for moving said engaging members (379P,379D,81P,81D). Die exchanging device as claimed in claim 11, characterised in that the plurality of carrying sections (39,339) are arranged in the direction of said Y-axis. Die exchanging device as claimed in claim 13, characterised in that the carrying sections (39,339) are arranged such that one of the carrying sections (39,339) can selectively move to a position in front of a tool stored in the storage unit (31,331).

Inventors: FUJIWARA TAKAYUKI, ITO SHIGERU, FUJIWARA, TAKAYUKI, ITO, SHIGERU
Applicants: AMADA CO LTD, AMADA COMPANY LIMITED
Application year: 1991
Main classification: B21D28
IPC codes: B21D37, B21D28