EP0037096B1 - Device working like a stamp or press - Google Patents

Abstract

A machine for punching or pressing sheet material comprises a support base, a stationary machine member and a machine member which is rectilinearly displaceable relative thereto for the working movement. At least one such member is fitted with a tool and in order to produce the working movement, a wedge is displaceable transversely to the direction of the said movement in a reciprocatory manner by means of a drive provided between the base support, or a member connected thereto, and the displaceable machine member, or a member connected thereto. The load transmitting surfaces on the wedge and the load transmitting surfaces facing the same on the adjacent support base and displaceable member are formed by hardened body-surfaces.

Description

The invention relates to a wedge press according to the first part of claim 1. Such a wedge press is known from GB-A-780 165.

From DE-OS 2 408 939 a machine for machining workpieces with high pressure, in particular a high-pressure press, is known, in which a piston forming the movable tool is raised and lowered by means of two wedges which can be moved apart and apart. A vibration wheel with large mass and internal eccentric surfaces is used to drive the wedges. This machine is intended to deform a workpiece in pressing processes, with a short contact time being achieved in order to protect the tools against excessive temperature rise and to avoid heat loss of the workpiece. It is therefore the hot forming of metallic workpieces.

Furthermore, from GB-PS 780 165 a machine for processing sheet metal is known, in which a machine part provided with a tool can be raised and lowered in the direction of a fixed machine part by means of a wedge that can be moved transversely and can be moved back and forth by a hydraulic cylinder . The transversely displaceable wedge is delimited on the top and on the bottom by inclined surfaces, which are assigned correspondingly inclined surfaces on the movable machine part and on the lower stationary machine part. Rollers are arranged between the pairs of surfaces.

Finally, a drop forging press is known as a tied crank press (DE-AS 1 265 548), which has a drive wedge for a tappet that can be moved horizontally from the crank pin of the crankshaft via a push rod. The drive wedge is clamped to the plunger on the one hand and the machine frame on the other by bars. The crank pin bearing is provided with an eccentric bushing which can be rotated by means of a worm gear. This allows the basic position of the drive wedge relative to the plunger and thus the position of the upper tool located on the plunger to be changed relative to a lower tool attached to the machine frame. A pressure-medium-operated adjustment device is also provided in order to be able to shift the stroke before the last forging operation by the amount of spring deflection of the press in order to carry out the calibration process.

In the case of metal-cutting machine tools, longitudinal guides with roller bearings are known for slide movements, and the raceways must have sufficient hardness (D. H. Bruins "Tools and machine tools for metal cutting", Carl Hanser Verlag, Munich 1965).

For wear-stressed metallic castings has been proposed (DE-GM 7326661), in the cast iron hard material particles, for. B. sintered carbide grains, spaced from each other so that they are largely clutched by the cast iron, while a small remaining part protrudes freely over the cast material surface. The area proportion of the hard material particles, projected onto the wear area, should be about 5% to 50%, that is to say make up at most half of the total area. It is only a wear protection as a replacement for armor by a surfacing. This means that accuracy requirements cannot be met.

There are numerous cases in which operations are to be carried out by means of a tool which can be moved in a straight line towards a material to be machined and away from it, with the requirement that the stroke or the end position of the tool must be observed very precisely when the working stroke is completed. This applies in particular to the manufacture of adhesive labels. There is a self-adhesive layer and a material web from which the labels are to be made on a paper or plastic carrier web. When punching out the label shape, only this material web should be punched through with the adhesive layer, but not the carrier web. Because of the extremely small thickness of such a web, compliance with this requirement has previously been very difficult. The example mentioned stands for other cases in which high accuracy is also important in a machining operation with a tool moving in a straight line.

The object of the invention is to overcome existing shortcomings, disadvantages and difficulties and to create a wedge press with which high accuracy requirements with regard to the work process can be fulfilled in a convenient and relatively simple manner. The invention also strives for an advantageous design of the device in detail and in the elements belonging to it. Further problems with which the invention is concerned arise from the respective explanation of the indicated solution.

The invention is characterized by the features specified in claim 1.

The fact that the movement surfaces are formed from the hard body surfaces to be explained in their details and their construction, it is possible to provide a displaceable wedge body for generating the working movement. The hard body surfaces can be produced with such accuracy and flatness that, in cooperation with the wedge body, a high precision of the device and thus also a high level of work accuracy are achieved.

The hard body surfaces can slide directly onto one another. However, rolling elements are advantageous between the movement surfaces Arrangements provided, in particular in the form of a needle bearing or the like. With corresponding cages made of plastic, as are known per se, so that there is no sliding friction.

In the invention it is not necessary to provide materials for the interacting parts, for example for the wedge body and for the movable machine part, which can be hardened. Rather, other and especially light materials can also be used for this. Thus, according to the invention, the wedge body and / or the movable machine part can even be made of aluminum or a light metal alloy, which has the advantage that the size of the masses to be moved is reduced.

In a further embodiment of the device, the invention provides that the tool is also fastened to the part carrying it on a hard body surface and / or that the machine part opposite the tool is also formed by a hard body surface. This further contributes to increasing the accuracy of the device and its operation.

For the reciprocating movement of the wedge body, a cam drive can advantageously be provided, for. B. an eccentric drive.

An adjusting device is advantageously assigned to the movable machine part. This can be designed particularly expediently so that the movable machine part can be displaced parallel to the direction of movement of the wedge body for its precise adjustment and is thereby adjusted in the direction of the working movement. An eccentric drive in particular can be used for adjustment.

• Fig. 1 eine Vorrichtung gemäß der Erfindung, teilweise im Schnitt nach der Linie I-I in Fig. 2,
• Fig. 2 eine Draufsicht auf die Vorrichtung nach Fig. 1,
• Fig. 3 einen Schnitt durch eine Hartkörper-Fläche nach der Linie 111-111 in Fig. 4,
• Fig. 4 eine Draufsicht auf einen Teil der Hartkörper-Fläche,
• Fig. 5 einen der Fig. 3 entsprechenden Schnitt bei einer abgewandelten Ausführung und
• Fig. 6 einen Ausschnitt aus einer Hartkörper-Fläche in größerem Maßstab.

Further details, features and advantages of the invention result from the following explanation of exemplary embodiments, from the associated drawing and from the claims. It shows

• 1 is a device according to the invention, partly in section along the line II in Fig. 2,
• 2 is a plan view of the device of FIG. 1,
• 3 shows a section through a hard body surface along the line 111-111 in FIG. 4,
• 4 is a plan view of part of the hard body surface,
• 5 a section corresponding to FIG. 3 in a modified embodiment and
• Fig. 6 shows a section of a hard body surface on a larger scale.

The device shown in FIGS. 1 and 2 has a base 1, a head part 3 firmly connected to it by means of a series of screw bolts 2 or corresponding rigid connecting elements, and a head part 3 up and down relative to the latter in the direction of arrow P1 in FIG. 1 movable machine part 4. The latter therefore executes a movement as is necessary to carry out a pressing, cutting, punching or punching out process. In particular, the device is suitable for punching out parts from an intermittently moving web, designated as a whole by the number 5, it being possible in particular for a combined web in which a self-adhesive layer is located on a carrier and one for forming labels or similar elements serving top layer made of paper or plastic. The die cut should only cut through the web used to form the labels and, if necessary, the adhesive layer, but not the backing web. This requires extremely precise operation of the device.

To generate the working movement of the movable part 4, a wedge body 6 is used which can be moved back and forth in the direction of arrow P2 (FIG. 1) by means of a drive by a given and preferably adjustable path. This wedge body 6 is supported with a horizontal underside on the base 1 and causes with its upper inclined surface the vertical movement of the part 4 provided on its underside with a corresponding inclined surface. In the illustrated embodiment, a cam mechanism is provided for the movement of the wedge body 6, of the two curves 8, z. B. eccentric, the peripheral surfaces of which abut on sliders 9 on the wedge body 6. Tension springs 10 or other suitable elements are used to ensure a permanent, fixed system when the curves 8 circulate. The curves 8 are driven together by a motor, not shown, which is located in the pedestal and expediently its speed can be changed or controlled.

In order to be able to precisely adjust the height of the movable part 4 relative to the fixed head part 3, depending on which material is to be processed, an adjusting device 11 is provided, which has two eccentrics 12, which are received by precise bores in projections 13 of the movable part 4 are. By simultaneously rotating these eccentrics 12, the movable part 4 is displaced horizontally by a corresponding amount relative to the wedge body 6, the base being simultaneously lowered or raised due to the inclined surfaces. This setting is very sensitive because of the translation given by the sloping surfaces. The common rotation of the eccentrics 12 can be carried out by a threaded spindle 15 to be rotated by means of the handwheel 14 and mounted in the base of the device, on which sit two nuts 16 on which levers 17 connected to the eccentrics 12 are connected in an articulated manner.

The surfaces referred to as movement surfaces, ie the top of the base 1 in the area of the wedge body 6, the bottom and top of the wedge body 6 and the inclined underside of the movable part 4 are formed by hard body surfaces F, between which rolling element arrangements 18 are provided are, in particular needle bearings or other rolling bearings suitable for linear movements.

The hard body surfaces F themselves are designed according to the invention as illustrated in FIGS. 3 to 6. 3 and 4 are in a hardened embedding 22, z. B. is an epoxy resin or a polyester resin, if necessary. With the addition of bronze or steel powder, balls 21 of the same shape and size held, the hardness of z. B. 65 to 68 Rockweil C. These can be ball bearing balls. These balls are ground to a part of their height after the investment has hardened, so that a large number of mutually adjacent end faces 23 (FIG. 4) result, which together form the hard surface F of the element E.

In the embodiment according to FIG. 3 there is still an area formed by the investment material of a height below the balls 21 which can be selected according to the respective need.

In the embodiment according to FIG. 5, which otherwise corresponds to that according to FIGS. 3 and 4 and in which the parts are designated with the same reference numbers, such a lower area is missing.

An element E of the type described can, for. B. be fixed by gluing or by clamping or in any other suitable manner on the aforementioned parts of the device.

Instead of inserting a prefabricated element, hard surfaces F on parts 4 and 6 or 1 and 3 can also be produced directly on them. Is z. B. Fig. 6 as a section through the top of the wedge body 6 along the central plane of embedded balls, it can be seen that the balls 21 are supported on the bottom 24 of a recess of the wedge body 6 and are surrounded by an investment material 22. After the latter has hardened, the balls have been removed from the original height H (diameter) to the final height h by grinding or another machining process. As a result, the hard surface F results from the large number of individual end faces 23 of these ablated balls 21, the areas of the investment material in between, which still appear on the upper side, being small. This is exaggerated in Fig. 4 for better illustration. The processed height H - h can be in particular in the range from 25% to 50%.

It has been found that such hard body surfaces F with an extremely high precision and high dimensional accuracy, i. H. Flatness can be produced, so that in connection with this an advantageous generation of the working movement in a device of the type described and high working accuracy of the device itself is achieved. With such a device, very difficult machining problems, such as u. a. punching or severing part of a sheet of thin material.

In an advantageous further embodiment of the device, the part carrying the tool, here the fixed head part 3, is equipped with a hard body surface F of the type described, so that the clamping or fastening of the tool, for example a steel strip cutting tool 19, with high accuracy is possible.

Furthermore, the part opposite the tool, here the movable part 4, is advantageously formed on its side facing the tool by a hard body surface F. A support made of copper, brass or the like can be arranged on this when carrying out a punching process.

By arranging the hard body surfaces F, it is otherwise not necessary to design certain parts of the device, for example the wedge body 6, from a material of increased hardness or strength. Rather, the wedge body and / or the movable part can also consist of a non-ferrous material, primarily a light material such as aluminum or aluminum alloy. This allows u. a. also reduce the mass forces when working.

In a further advantageous embodiment, the device shown in FIGS. 1 and 2 is equipped with a quick adjustment device 30 for the movable machine part 4. This makes it possible to lower the movable machine part 4 regardless of its setting or adjustment for the working process by such an amount that, when the wedge body 6 is moved back and forth, the machine part 4 still moving up and down in the upper one upon a command The turning point of his working movement is so deep that the material web 5 is no longer punched or cut by the tool 19. This can be beneficial in several cases, e.g. B. when one end of a web 5 is connected to the start of a new web by gluing or the like, and the overlapping of the web parts results in twice the thickness, which can lead to the fact that not only an upper one at this point , for example intended for label position of the web is cut, but also one of the carrier layers.

The quick adjustment device can be formed in various ways. There are all the designs within the scope of the invention with which the described effect can be achieved, in particular by moving the movable machine part 4 parallel to the direction of the arrow P2. A device that is independent of an adjusting device or one that is combined with the latter can be provided. This is shown in the exemplary embodiment. The threaded spindle 15 of the adjusting device 11 can be displaced with the nuts 16 in the axial direction by a sufficient amount, for example with the aid of a pressure medium cylinder 31, the piston rod 32 of the piston 33 displaceable therein being coupled to the threaded spindle 15 via a connection permitting the rotation of the latter. In the position shown, the piston 33 has an end position which is precisely defined by a stop or the like, as a result of which the setting and exact working position of the movable machine part 4 which is effected by means of the handwheel 14 is ensured. The piston 33 can be held in this position by the action of pressure medium or by a strong spring 34.

From this position, the piston 33 can be extended over its entire stroke or only a part thereof by supplying a pressure medium to the cylinder 31 via a valve 35, whereby it moves the threaded spindle 15. As a result, the eccentrics 12 are rotated via the levers 17 in such a way that the movable machine part 4 undergoes a shift in size, to the left in FIG. 1, that it is only lifted vertically during the reciprocating movement of the wedge body 6, that the tool 19 can no longer cut the web 5. By switching the valve 35 and thereby reducing the pressure in the cylinder 31, the piston 33 and all the parts connected therewith return to the starting position, so that the device continues to operate normally.

The valve 35 can be actuated manually at the desired time, furthermore also by a program or in particular depending on the response of a sensor 36 scanning the path 5 (FIG. 1), which, for. B. is able to detect a temporary thickening of the web and can otherwise be formed in a manner known to those skilled in the art. The number 37 in FIG. 2 denotes a control device which, on signals supplied by the sensor 36 via a line 38, causes the valve to be actuated. By means of such a sensor 36, the valve 35 can in particular also be actuated with a delay caused by a timing element in the control device 37, which is just selected so that the movable machine part 4 is adjusted by means of the device 30 to suppress a cutting process when the relevant one Location of the intermittently moving web is located under the tool 19. By means of sequence control or in another suitable manner, the part 4 can be reset immediately afterwards by the device 30, so that the next working stroke is carried out normally again. Accordingly, the suppression of the cutting process is possible for several strokes if necessary.

Claims (13)

1. A wedge press for punching out flat objects from web-like or sheet-like material, in particular in the production of adhesive labels, having a support base (1), a stationary machine member (3) and a machine member (4) which is displaceable relatively thereto in a rectilinear manner to the working movement, between which members a tool (19), namely a cutting tool, is disposed, there being provided between the support base (1) and the movable machine member (4) a wedge (6) which can be moved in a reciprocatory manner by means of a drive (7, 8) transverse to the direction of the working movement in order to produce the latter, characterized in that the movement surfaces on the wedge (6) and the movement surfaces, facing these surfaces, on the adjacent members (1, 4) are formed by hard body surfaces (F) which are comprised of hard bodies (21) which are embedded in a mass (22) and, in the initial state, are spherical and whose original height (H) in the embedded state is reduced to a final height (h) by removal work in such a way that in the final state produced in this way there are end faces of the hard bodies (21) in one plane.

2. An apparatus as claimed in claim 1, characterized in that rolling bearings (18) are provided between the movement surfaces (F) in a manner known per se.

3. An apparatus as claimed in one of claims 1 and 2, characterized in that the tool (19) is secured on the member (3), bearing the latter, on a hard body surface (F).

4. An apparatus as claimed in one of claims 1 to 3, characterized in that the member (4) lying opposite the tool (19) comprises a hard body surface (F).

5. An apparatus as claimed in one of claims 1 to 4, characterized in that a cam drive (8) for the reciprocatory displacement of the wedge (6) is provided.

6. An apparatus as claimed in one of claims 1 to 5, characterized in that the displaceable machine member (4) is adjustable parallel to the direction (P2) of movement of the wedge (6) by means of an adjusting device (11).

7. An apparatus as claimed in claim 6, characterized in that an eccentric drive (12, 13) is provided for the adjustment.

8. An apparatus as claimed in one of claims 1 to 7, characterized by a rapid adjustment device (30) for the displaceable machine member (4).

9. An apparatus as claimed in claim 8 and one of claims 6 and 7, characterized in that the rapid adjustment device (30) is combined with the device (11) for the adjustment of the displaceable machine member (4).

10. An apparatus as claimed in one of claims 8 and 9, characterized in that the rapid adjustment device (30) comprises an element (33) which is actuatable by pressure means.

11. An apparatus as claimed in one of claims 8 to 10, characterized in that the rapid adjustment device (30) is controllable dependently upon an element (36) which can be influenced by the material (5) to be treated.

12. An apparatus as claimed in one of claims 1 to 11, characterized in that the wedge (6) consists of a non-ferrous material.

13. An apparatus as claimed in one of claims 1 to 12, characterized in that the displaceable machine member (4) consists of a non-ferrous material.

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