The invention relates to a method and device for transferring work pieces into and out of a tool, in particular a multi-staged cutting and processing tool, wherein a blank is cut out of a clamped flat strip in an upper part.
A method and device are known from EP2 036 629 B1 for fine blanking and forming of a work piece made from a flat strip, wherein a plurality of processing stages lie in a circular path. The work pieces are transferred from one processing stage to the next by way of a rotatable cutting plate. This results in the cutting plate having both a cutting function and a transport function, which leads on one hand to a complicated design of the fine blanking tool and on the other hand encourages wear in the cutting plate due to the continuous sequence of aligning and locating in order to cut the work pieces and the rotational movement to transport the work pieces. Therefore, continuous monitoring of the active elements is required to maintain the precision and accuracy of the fine-blanked parts.
There is also a device known from EP 2 444 172 A1 for removing precision-punched or fine-blanked parts from a tool. The device makes use of a linearly movable cross slide to transport the work piece, the cross slide being movable into the work space between the working parts when the tool is opened, and out of the tool when it is closed. For multi-staged tools, this means that each work operation can only be carried out after the cross slide is moved out of the tool. The time it takes to open the tool must be accounted for, increasing the finishing time per part and decreasing productivity. Also, the linear slides require sufficient space and therefore make compact tool design difficult.
An object of the invention is to provide a device and a method for transferring work pieces in and out of multi-staged cutting and processing tools that eliminates the need to move the slide into and out of the tool while at the same time increasing the number of strokes and economic efficiency, degree of precision in the parts, improved compactness in the tool, and a simplified design.
Of significance is that the slide is designed as a rotary slide including a plurality of transfer openings and a discharge opening. Also, the cutting stage and the individual processing stages are designed with a discharge stage as separate, mutually-supporting components arranged about a rotating axis of the rotary slide, the axis being supported at the lower block. The transfer openings and the discharge opening lie in a circular path that coincides with the circular paths of the active elements of the cutting stage, the processing stages and the discharge stage. The transfer openings have a distance from one another that is identical to the arc distance between the active elements in the circular paths.
This is achieved in that the rotary slide comprises a slide plate in which the transfer openings and the discharge opening are matched to the size and shape of the cutting and processing stages in order to accommodate the blanks. The slide plate is connected to a linear drive that is arranged approximately tangential to the lower pressure plate and the lower frames coaxial to the circular path. The drive executes a horizontal pivoting motion of the plate about a rotating axis fixed at the lower block of the lower part. The slide plate connection is such that the transfer openings located in the circular path and the discharge opening of the slide plate seize the blanks after the plate pivots in the direction of the cutting stage by an amount equal to the arc distance of the cutting stage and the processing stages in the circular path. These openings can then drop the blanks from the cutting stage into the subsequent processing stages after the slide plate pivots hack from the cutting stage.
According to a preferred embodiment of the device according to the invention, the slide plate can he damped between the frames of the active elements of the processing stages of the upper and the lower parts upon dosing in such a way that the active elements can process the blanks through the transfer openings. The slide plate thus becomes an integral part of the tool.
In another embodiment of the invention, the distance from the rotating axis of the slide plate to the far edge of the flat strip away from the slide plate is equal to the radius of the slide plate. This makes it possible to provide two mirror-imaged rotary slides in the travel direction of the flat strip opposite one another, having pivot directions opposite to one another for transferring the blanks and work pieces. The two rotary slides are disposed offset relative to one another in the direction of travel of the strip at a distance that is equal to about four times the arc distance of the cutting stage and the first processing stage in the circular path.
In another useful embodiment of the device according to the invention, the slide plate is disposed in a plane that allows horizontal pivoting of the slide plate with the transfer openings and the discharge opening directly over the respective active elements of the cutting stage and processing stages when the tool is open. In this way, the transfer openings and the discharge opening reach a position in which they can accommodate the blanks and grasp them for transport.
According to another embodiment of the invention, the slide plate is designed as a section of a circular disc provided with a dog at the periphery thereof facing the linear drive. The dog is connected to a carriage guided in a guide rail of the linear drive for purposes of executing the pivot motion of the slide plate about the rotating axis.
It is also an advantage that the slide plate comprises stop plates with stops at the frames of the active elements of the lower part for limiting the displacement of the linear drive to the arc distance between the fine blanking stage and the processing stages.
Another preferred embodiment of the device according to the invention provides that the transfer opening for the cutting stage is provided with claws for gripping the cut blank. The transfer openings for the processing stages are provided with transport masks for aligning and fixing the blanks. The opening fix discharging the finished work piece is provided with transport magnets for lifting and feeding to a chute.
According to another preferred embodiment of the device according to the invention, the discharge stage comprises an ejector fixed to the upper block of the upper part and located in the circular path. The ejector separates the finished work piece from the transport magnets of the discharge opening to a discharge chute.
In another preferred embodiment of the invention, the chute is disposed perpendicular to the circular path and parallel to the direction of travel of the strip. The chute is connected to at least one conveyor belt for removing the finished work pieces, the direction of removal of the conveyor belt being perpendicular to the chute.
The object is further achieved by transferring the blanks between the cutting stage and the processing stages when the tool is open using a reversible slide plate of a rotary slide. The plate includes transfer openings and a discharge opening. The rotary slide seizes the blank cut in the cutting stage by making a first pivot motion by an amount equal to the arc distance between the cutting stage and the processing stages and bringing it to the first processing stage in a second direction of identical arc distance opposite to the first pivot motion for processing. At the same time the blanks from the first processing stage and from the other processing stages are shifted to the next respective processing stage, and the finished work piece is discharged.
The method according to the invention proceeds substantially with the following steps:
a) holding the flat strip at the guide plate of the upper part when opening the tool, which is done by lowering the lower part;
b) pivoting the slide plate and the transfer openings and discharge opening thereof that lie in the circular path. until the first transfer opening facing the cutting stage sits over the cutting stage, and the remaining transfer openings sit over the processing stages, and the discharge opening sits over the last processing stage,
c) ejecting the blanks from the cutting stage and the processing stages to the respective transfer openings and ejecting the finished work piece into the discharge opening,
d) pivoting the slide plate in a direction opposite to step b) with the blanks seized by the transfer openings until the slide plate releases the cutting stage, and the transfer openings with the blanks reach the next processing stages,
e) aligning and centering the blanks in the processing stages and accommodating the finished work piece in the discharge opening, and
f) clamping the slide plate between the frames of the active elements of the processing stages of the upper and lower parts simultaneously with the clamping of the strip material in the cutting stage when closing the upper and lower parts in the position reached according to step e), such that the active elements of the processing stages can process the blanks through the transfer openings, a new blank is cut in the cutting stage and the finished work piece is pushed out of the discharge opening by an ejector to a chute for removal.
One particular advantage is that the rotary slide is driven by a linear drive attached at the lower block and running tangentially coaxial to the circular path. The displacement of such linear drive matches the arc distance between the cutting and the processing stages in the circular path so that it is certain that the respective transfer and discharge opening always sits over or reaches the corresponding active elements, and so that the cutting stage is exposed for the next cutting process.
In another embodiment of the method according to the invention, rotary slides are used on both sides of the flat strip to transfer the cut and processed blanks. The pivot directions of the rotary slides are directed opposite to one another so that the entire width of the flat strip can be used for cutting.
In another preferred embodiment of the method according to the invention, the far side edges of the fiat strip are guided over the periphery of the respective slide plate of the respective rotary slide, resulting in the rotary axes of the rotary slide being equal distances away from the flat strip, respectively.
Other advantages, features and details of the invention can be found in the following description with reference to the attached drawings.
The invention is described in more detail below using an example of the manufacture of a fine-blanked part with internal cogging. It is understood that stamped or fine-blanked parts of other configurations are also covered by the invention. Shown are:
The cutting and processing tool 1 has two cutting stages 8 and 8.1 separated from one another in the direction of travel R of the strip and a plurality of processing stages 9 to 12 and 9.1 to 12.1 per cutting stage, respectively, as well as one discharge stage each 13 and 13.1. As shown in
The chamfer angle α at the guide plate 18 is matched with the central angle φ of the circular-segment components A, B, C and D such that it is equal to 0.5 times the mid-point angle φ. As a result component A sits directly against the chamfers 20 and 20.1 of the guide plate 18 next to cutting stages 8 and 8.1 in circular paths K1 and K2, respectively.
As shown in
The cutting plate 27 is located in the center of the tool along with the guide plate 18 in the direction of travel R of the strip and has a longitudinal polyhedron-shaped member 30, which is the same identical shape and form as the guide plate 18, with two chamfers 31 and 31.1, with which each of the lower parts of the cutting stage 8 and 8.1 is associated, respectively. The lower parts of the cutting stages 8 and 8.1 lie in the cutting plate 27 in a circular path K3 and K4 superimposed about the center point P3/P4. The lower active elements of processing stages 9 to 12 and 9.1 to 12.1 lie in the circular path as separate lower components E, F, G and H in the form of circular segments, as does a chute 32 of discharge stages 13 and 13.1. Components E to H each comprise separate lower pressure plates 33 and lower frames 34 in which are accommodated the lower active elements 35, such as an anvil, cutting plate inserts, punches for drawing, calibrating and supporting, as well as ejectors.
The chamfer angle al on the cutting plate 18 is matched to the central angle φ1 of the circular-segment lower components E, F, G and H in such a way that it is 0.5 times the central angle φ1. This causes component E to come to sit directly against the chamfers 31 and 31.1, respectively, of the cutting plate 27 on the respective circular paths K3 and K4 along with the lower active elements of cutting stages 8 and 8.1, respectively (see
A rotating axis DA of a slide plate 36 of a rotary slide 37 is positioned in perpendicular alignment with the center points P1/P2. of the lower circular paths K1/K2 and the center points P3/P4 of circular paths K3/K4—as shown in
The rotating axis DA is a distance b away from the far side edge SR of the flat strip 7, the distance being equal to the radius r of the slide plate 36 (see
Stops 42.1 and 42.2 are associated with the carriage 41 that runs along the guide rail 40 and are attached at the exterior periphery of the lower frames 34 at a distance which allows the path of displacement of the carriage 41 on the guide rail 40 to be limited to the arc distance BA. To accomplish this, the slide plate 36 is provided with corresponding stop plates 59 which are associated with the stops 42.1 and 42.2.
The lower part of the discharge stage 13 and 13.1 includes the chute 32, which is attached at the lower block 6, The chute slopes downward from the chute entrance 43, which lies in the circular path K3/K4, to a conveyor belt 45 and 45.1 running along the longitudinal sides 44 of the lower part 4 for taking away the finished work pieces.
The slide plate 36 has a protrusion 55 at the exterior periphery 51 thereof for attaching a dog 53 connected to the carriage 41 of the linear drive 39. The dog executes a reversible pivoting motion between stops 42.1 and 42.2 about the rotating axis DA.
Claws 54 placed in the transfer opening 46 can seize the blank 2 cut in cutting stages 8 and 8.1 as soon as the transfer opening 46 arrives over cutting stage 8 and 8.1 by way of the pivot motion about the rotating axis DA. The transfer openings 47 to 49 are provided with transport masks 55 that enable the blanks 2 to be exactly fixed and aligned relative to the respective processing stage. The discharge opening 50 comprises transport magnets 56 that fix the finished work piece 58 and position it for discharge by way of the chute entrance 43.
The method according to the invention is explained below with the aid of
The slide plates 36 have made a horizontal pivot motion—as shown in FIG. 9—under the flat strip 7 about rotating axis DA in the direction of the arrows in circular path K5 in arc distance BA in a plane that lies directly above the active elements. Thus, the first transfer opening 46 facing the cutting stage 8 and 8.1 comes to lie above the active elements of the cutting stage 8 and 8.1. At the same time, the transfer openings 47 to 49 have moved over the corresponding active element of the processing stages, and the discharge opening 50 has moved over the corresponding active elements of the processing stages 9 to 11 and 9.1 to 11, and the discharge opening 50 has reached processing stage 12. The protrusion 52 of slide plate 36 is then located at stop 42.2, which is positioned at the outer periphery of the lower frames 34.
In simultaneous fashion, the blank 2 cut in cutting stage 8 and 8.1, the processed blanks 2 in the other processing stages 9 to 11 and 9.1 to 11.1, and the finished work piece 57 are ejected to transfer openings 46 to 49, and the finished work piece 58 is ejected to discharge opening 50.
Slide plate 36 pivots back in a direction opposite to the first pivot motion by the arc distance BA in circular path KS together with seized blanks 2 and the finished work piece 57. The slide plate 36 releases the cutting stage 8 and 8.1. Transfer openings 46 to 49 with blanks 2 reach processing stages 9 to 12. The blanks are placed in the correct position in processing stages 9 to 12 and 9.1 to 12.1 using the claws 54 and transport masks 55 located in the transfer openings 46 to 49. The finished work piece 57 was transported simultaneous to this through the discharge opening 50 by way of the transport magnets 56 to the chute entrance 43 of the discharge stage 13 and 13.1.
The flat strip 7 is guided over the center of the tool 1 in such a way that the respective far side edges SR of the flat strip 7 facing away from the slide plate 36 are guided over the periphery 51 of the slide plate 36 so that a rotary slide 37 can be used to transfer cut and processed blanks 2 and finished work pieces 57 on each side of the flat strip 7, the pivoting directions of the slides being opposite directions to one another. The rotary slides 37 are offset in the direction BD of travel R of the strip by about four times the arc distance BA such that a sufficient cycle time is available for each processing cycle.
Number | Date | Country | Kind |
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13004193.2 | Aug 2013 | EP | regional |