DE19648952C1 - Device for breaking out and removing waste stampings from sheets or material sheets, in particular for flat-bed stamping and / or embossing machines - Google Patents

Abstract

This invention consists of a device and procedure to break out and remove residual stampings cut from panels or sheet material, particularly for use in automatic flat-bed punching and/or stamping machines. Needle-shaped stripping devices (12) are fitted to a stripping mould in such a way that they remain resilient and elastic around the points where they are embedded in or attached to the mould. The stripping needles (12) consist a conical or arched section which tapers to a tip (14) and accounts for more than half the total length of the needle. Preferably, the ratio R of needle length l to maximum needle diameter d should be between 6 and 80, whereby the maximum needle diameter is </= 2 mm. Stripping needles fitted on or inside the stripping mould can be combined with established cutting tools, rigid stripping pins or stripping punches.

Description

The invention relates to a device for Breaking out and removing waste stampings from panels or Material sheets, especially for flat bed punching and / or Embossing machine, comprising a stripping board for receiving the Benefit or material sheet, an upper and / or lower Stripping mold as a stripping tool holding plate, the Stripping tool with stripping tools towards the stripping board is vertically movable, further comprising in the stripping board provided recesses or openings by the respective Waste stamped part of the material sheet are spanned.

DE 41 24 098 C1 describes a device for removing Contain break-out parts from a blank or the like tendency material sheet known. The material sheet lies on a carrier plate in which openings with continuous  vertical walls are provided. Every stripping part of the Material sheet spans the associated breakthrough and is, as mentioned, with corresponding contact surfaces on the Carrier plate on.

On the work that can be moved towards and away from the carrier plate Tool holding plate are stripping tools made of steel strip arranges. The stripping tools have vertical and horizontal Narrow sides. Any of the known stripping tools Steel strip has at least one point towards the carrier plate as the end of the respective vertical narrow side. The angle α between the tip and the one from it to the adjacent one, the horizontal narrow side facing the carrier plate extending surface projected into the narrow side center plane should be in a range from 20 ° to 50 °.

With the help of technologically very complex apprentices The knockout part should have tips or tips when pressed into the respective breakthrough does not slip, so that a Safe separation and spinning of the waste piece even without additional wiping elements in the carrier plate is possible. In order to improve the desired effect, it is featured there beat, which extends from the tip to the carrier plate side horizontal narrow side of the steel stripping tool extending surface so that they have the shape of a has isosceles triangle, its acute angle is preferably 60 °. It is obvious that the ent speaking grinding is production-intensive, in particular if you assume that the peaks raise you Lichen are subject to wear, so that in addition a frequent tool change becomes necessary.

From German utility model 90 03 329 it is known rotationally symmetrical pins with tips as stripping tools to use, the tips with elastic abutments in arranged lower area of the stripping mold, cooperate. When the stripping pin returns in connection with the The stripping part is removed from the abutment. The disadvantage is however, the rigid embodiment of the rotationally symmetrical  Pins in conjunction with the elastic abutments that are extremely susceptible to wear.

From the company publication BOBST SA, 1992, DOCtraining Knockout pins known, the smallest diameter at about 4mm with a free length of 35mm. The breakout pins from the front into corresponding holes crushed form inserted or used and indicate this a shoulder so that the desired length Positioning can be achieved. A lot of them arranged stripper then serves to remove waste stamped parts, as already described above.

Especially for very small waste and stripping parts the known stripping pins are not suitable. At acquaintances Stripping tools are flat or band-shaped elements Stamp larger diameter at best with a tip provided so that there is a corresponding change of steel strip or stamp and tip results. The stamp and tip are in shape firmly connected or flat on the head, serrated or with one corrugated structure.

Due to the size geometry of the known stripping elements arise when breaking out on high-speed punch car mate significant problems. On the one hand, the well-known Aus Crushing elements, as already mentioned, can be used for very small ones refractive parts too large, so that they are not sufficient Success can be removed. Because of the fixed effect connection between tip and punch or steel strip the tips do not cut at the critical points attack geometry. By the specified lines of action of known tips in connection with the vertical narrow side of the tool according to DE 41 24 098 C1, it is not possible To prevent torques of the parts to be broken out, so that Faults in the automatic operation of a flat bed die cutter Episode are.

Because of the geometric design of known tips when touching the material sheet surface and for locking  of the waste stamping part requires a large counterforce, which is not present in the normal die cut, so that additional Breakpoints in the stripping or punching form are necessary.

Ultimately, the additional stops increase the Required pressure force in the stripping station of a flat bed punch automatons. In addition, unwanted vibrations build up of the material sheet on the positioning and rest position adversely affect the stripping process. Due to the previously mentioned problems, it was previously necessary to use pencils to use.

It is therefore an object of the invention to provide a device for breaking out and removing waste stampings from sheets or material sheets, especially for flat beds stamping and / or embossing machines indicate which one it allows with reduced pressure force in the off breaking station both the incoming material sheet hold, smooth and position, even the smallest Remove waste stampings safely and completely.

The object of the invention is achieved with a counter stood according to the features of claim 1. The subclaims provide at least purpose moderate developments or refinements of the invention.

An essential basic idea of the invention is that previous rigid system between stripping mold or stripping tool holding plate and stripping tool to leave derge stalt that now the stripping tools at least partially are designed as break-out needles, which are opposite their respective clamping or fastening point in the stripping mold are resiliently flexible. By the corresponding the slim and elongated needle shape presents itself desired elastic mobility, so that a safe Break out and remove especially very small breakouts parts is given.  

According to the positioning of the knockout needles very small stripping parts made such that before preferably three needles form a group that is the same sided, isosceles or uneven triangle stretch, the needles related to critical breakout points can be freely positioned.

To safely and successfully break out larger ones too Waste stamping parts, the z. B. tapering critical According to the invention, sections can be combined Nation of breakaway needles with breakout known per se tools can be used.

In a preferred embodiment, the knockouts have needles compared to the combined stripping mechanism produce a greater height and it is ensured that the elastic mobility of the respective needle relative to their respective clamping or fastening point opposite beard stripping tools are preserved.

The needles according to the invention can be set independently, so that the number of breakpoints can be reduced or stop points can be completely eliminated.

The needle-shaped stripping tools fulfill the function of Prepositioning of the material sheet, pressing and Holding it and smoothing the arc starting from a gripper section on all sides, so that the The material sheet lies flat on the stripping board. Here too is the elasticity of the breakaway needles and the provision targeted differences in height or length of the needles from Gripper or geometric center of gravity starting outwards an advantage. Overall, unwanted swinging of the material arches and bulging them in the sudden Decelerate in the stripping section of an automatic punching machine changes, which affects the productivity and quality of the machined material sheets increased.  

It is within the spirit of the invention that the breakaway needles too with tools for edge separation or with holding blocks for Run abt or break out larger parts work together can, however, the desired elastic movement around the Clamping or fastening point of the respective needle safely must be posed.

The stripping needles according to the invention have a conical shape or arcuate portion forming a tip, wherein this section is essentially half the needle length occupies. In a preferred embodiment, the breakout needling is the ratio V of needle length l to the largest Diameter d of the needle is in the range from 6 to 80, where the largest diameter of the breakaway needles in the range ≦ 2mm lies.

For all-round smoothing in the break-out section of the Flatbed punching machine incoming material sheet or a so-called benefit are the breakaway needles over the Stripping form from the center or the geometric center of gravity the stripping mold and / or from the gripper section to Fixing the material sheet on the stripping board starting so arranged that the needles have a greater free length or height related to the other areas or directions exhibit. This is to be understood as the needles in the other directions starting from the gripper or geometric Focus from a decreasing length or height, so that with lowering the stripping mold and putting on the off break needles on the sheet of material to smooth the surface on all sides Material sheet is made according to the level stripping board.

According to the breakaway needles from the back inserted into the stripping mold and fastened in it. Preferably, the stripping mold, which is made of multi-layer glued plywood, by laser radiation created holes that have a slightly smaller through have a knife than that of the needles. To ensure an exact height or lengthwise positioning of the stripping needles To reach the stripping mold, the stripping needles have  a V- or goblet-shaped fastening shaft, the upper flush with the back of the stripping mold.

So it will be the needles in the laser holes or in breakthroughs produced or introduced beat, the fastening shaft forming a stop.

After positioning the Break-out needles in the break-out form become a known one Relative movement between the one having the stripping needles Stripping form and the Aus with a material sheet crushing board executed. With the beginning touch of the Arch through the break-out needles takes place in the preposition pressing and smoothing as well as holding the bow. As movement continues, the desired breaking out will be of the waste part with reference to the state of the art less pressure required. Ultimately it will using the stripping needles according to the invention prevents position ver changing vibrations of the bow arise. The existing ones Lateral forces generated by the bow when swinging are caused by Opposing forces due to the needle elasticity of the fixed stretched needles added, so that a flatness of the Bogens results in a highly productive and effective overall automatic removal of waste parts with largely no need is given on lower pins.

In summary, the breakaway needles represent elements that a punctiform, elastic attack on the waste allow stamped part, the breakaway needles no fixed, direct connection to other known per se Have crushing tools.

An upper stripping mold in particular has stripping needles, a larger one on the gripper and / or inner surface section Height in relation to the right, left and rear edge take cuts so that a smoothing of the incoming Material sheets is guaranteed.  

Due to the needle geometry, even very small parts can be attached critical points are fixed so that a successful Breaking out of these small parts is guaranteed. The almost punctiform small contact or contact surface of the Needle tip also allows penetration into the surface of the bow without the introduction of auxiliary elements that create a counterforce elements in the bow, e.g. B. of additional stops or specially trained conditions on the breakthroughs of the Streaking boards, too. A jamming of the waste stampings by accidentally turning them in the stripping board can be countered by the fact that the individual breakaway needles Open the triangle.

The invention is illustrated below with the aid of an embodiment game and explained with the help of figures will.

Here show:

Fig. 1 is a schematic representation of a flat bed stamping presses with stripping;

Fig. 2 is a schematic representation of the arrangement of breakout board and stripping mold within the stripping station and

Fig. 3 is a schematic representation of a stripping needle according to the embodiment.

The flat-bed punching machine shown in FIG. 1 has a loading and planting station 1 which has means for feeding the individual material sheets 2 to a punching station 3 . After punching in the punching station 3, remaining waste punching parts 6 or stripping parts are removed in a stripping station 4 . The stripping station 4 contains a tool frame 5 for upper and lower tools and for a stripping board. After the removal of the waste stamped parts 6, the thus processed material sheets 2 arrive at a Stapelauslage- and -abgabestation. 7

The performance of well-known flatbed punching and / or embossing machines lies in the range of 5000 to 6000 material sheets per hour, the maximum punching force can be 600 t. Maximum Sheet formats are in the range of 1020 × 1500 mm. Of the Gripper edge adjustment range for holding the material sheets takes about 10 to 15mm. Die cutting and embossing machines can use paper with a basis weight of at least 70g / qm and box or Solid cardboard up to a basis weight of 2000g / qm or well Process cardboard up to a total thickness of approximately 4mm.

Result from the specified sheet output per hour considerable sheet movement or transport speeds corresponding forces when braking or accelerating the Material sheets in the respective station, with the consequence of Bulges, especially when holding within the punching and stripping station. In addition, it is necessary to Posi to achieve the accuracy of the material bends are on the order of magnitude smaller than the smallest Breakout parts is.

With the aid of FIG. 2, a device for breaking out and removing waste punched parts, which are located within the breaking out station 4 according to FIG. 1, will now be explained in more detail.

The device, as shown in Fig. 2, has a stripping board 8 , which is used to accommodate the benefits or the material sheets 2 . The stripping board 8 has cutouts or openings 9 in accordance with the position of the waste punched parts. Above the stripping board 8 there is an upper breaking mold 10 , which consists of layered and glued plywood. The stripping mold 10 serves as a stripping tool holding plate and is vertically movable relative to the stripping board 8 . The direction of movement is symbolized by an arrow. The stripping mold 10 has longitudinal bores 11 into which stripping tools 12 , in the example shown in the form of a stripping needle, can be inserted and fastened.

The knock-out needle 12, which is inserted into the stripping mold 10 from the rear and fastened to a clamping point 13 , is capable of performing an elastic movement around the fixed clamping point 13 due to its given relationships between diameter and length.

When lowering of the punching mold 10 with the punching needles 12, the needles 12 first touch the surface of the material sheet 2, hold and flatten it, and then penetrate the recesses or apertures 9 in the stripping board 8 below with the name and removing the waste portion dance. 6

In a further embodiment, the stripping needles 12, starting from a gripper section or the geometric center of gravity of the stripping board 8 or stripping mold 10 , have a greater free length, that is to say protruding from the stripping mold 10 , in comparison to the edge sections, so that the lowering or , so that a reliable and optimum area, that is, flat contact of sheet of material 2, board on the surface of the driftout 8 is given to the relative movement of the punching mold 10 and stripping board 8 towards each other, smoothing the introduced material sheets 2 from the center towards the edge area he follows. In order to allow a correspondingly quick displacement of air between material sheet 2 and stripping board 8 , holes can be provided in the stripping board.

Especially with very small waste parts, the kriti sections of these parts associated with breakaway needles.

In the case of larger waste parts, the knock-out needles 12 can be used with known knock-out tools, e.g. B. in the form of streak lines can be combined. In the latter case, however, an unimpeded lateral, elastic movement of the break-out needles around their respective clamping point, ie a corresponding lateral distance from the rigid break-out lines or break-out punches, must be observed. In addition, there is a vertical distance between the stripping needle and another stripping tool.

FIG. 3 shows a particularly preferred embodiment of a Ausbrechnadel 12th This break-out needle 12 has a conical or arcuate section 14 which forms a tip, this section 14 taking up essentially half of the free needle length l. The maximum diameter of the needle 12 is denoted by d.

The ratio V of needle length l to the largest diameter d the needle is generally in the range of 6 to 80, where the largest diameter d of the needle is ≦ 2mm.

The end of the mounting shaft 15 of the Ausbrechnadel 12 has a V-shaped or cone-shaped end 16 which serves to form breaking or turning of the locking Ausbrechnadel in the bores of the corner. The stripping needles are fastened in the stripping mold in such a way that the V-shaped or conical end 16 of the fastening shaft is flush with the back of the stripping mold. In a particularly preferred embodiment, the total needle length is approximately 50 mm with a tip section of 25 mm. The breakout needle is inserted with its fastening shaft and the conical end into a 15mm thick wooden plate that forms the breakout shape. The diameter of the needle according to the preferred embodiment is approximately 1.2 mm.

Particularly in the case when the longitudinal bores 11 are made in the stripping mold 10 by means of a laser, the cross-sectional area of the bore with alternating micro-recesses and projections results in a firm press connection between the stripping needle 12 and the stripping mold 10 , with the V or conical shape of the end 16 the desired desired height positioning is secured and unwanted twisting of the needle can be prevented. The exact fit or the exact attachment of the stripping needles in the stripping mold can be checked or determined by a quasi tuning fork test, ie striking the stripping needles.

Claims (9)

1. An apparatus for breaking and removing waste stamped parts (6) of benefit or material sheets (2), in particular for Flachbettstanz- and / or embossing machine, comprising a stripping board (8) for receiving the benefit or material sheet (2), an upper and / or lower punching mold (10) as Ausbrechwerkzeughalteplatte, wherein the punching mold (10) toward vertically movable with stripping tools (12) for stripping part (8) in the stripping part (8) provided recesses or openings (9) extending from the respective drop stamped part (6 ) of the material sheet ( 2 ) are spanned, characterized by essentially vertically fixed in the knockout mold ( 10 ) needle-shaped knockout tools ( 12 ), the knitting needles ( 12 ) thus formed being flexibly and flexibly movable about their respective clamping or fastening point ( 13 ) . 2. Apparatus according to claim 1, characterized in that for breaking out the smallest waste punched parts ( 6 ) a combination of three arranged in irregular or regular triangular breakout needles ( 12 ) are each fixed in the breakout mold ( 10 ). 3. Apparatus according to claim 1 or 2, characterized in that the break-out needles ( 12 ) have a conical or bogenför shaped, a tip-forming section ( 14 ), this section occupying substantially half the needle length. 4. Device according to one of the preceding claims, characterized in that the ratio V of needle length l to the largest diameter d of the needle substantially in the range of
V = 6 to 80
lies, whereby the largest diameter is ≦ 2mm. 5. Device according to one of the preceding claims, characterized in that in addition to the stripping needles ( 12 ), the stripping mold ( 10 ) has known rigid cutting-like stripping tools, stripping pins and / or stripping punches, the other stripping tools only indirectly via the stripping mold ( 10 ) communicate with the knock-out needles ( 12 ). 6. The device according to claim 5, characterized in that the knock-out needles ( 12 ) protrude relative to the further knock-out tools and are laterally spaced from these that the elastic mobility around the clamping or fastening point ( 13 ) is retained. 7. Device according to one of the preceding claims, characterized in that the stripping needles ( 12 ) on the stripping mold ( 10 ) from the center or the geometric center of gravity of the stripping mold ( 10 ) and / or of the gripper section for fixing the material sheet ( 2 ) have a greater free length or height in relation to all other areas or directions on the stripping board ( 8 ), so that when the stripping mold ( 10 ) is lowered and the stripping needles ( 12 ) are set down, the material sheet ( 2 ) is smoothed on all sides. 8. Device according to one of the preceding claims, characterized in that the stripping needles ( 12 ) from the back of the stripping mold ( 10 ) are inserted and secured in this. 9. The device according to claim 8, characterized in that the knock-out needles ( 12 ) have a V- or conical or goblet-shaped end ( 16 ) of the fastening shaft ( 15 ), this end ( 16 ) flush with the back of the knock-out mold ( 10 ) completes.