DE2356250C2 - Device for the production of blanks - Google Patents

Description

■ 5 The invention relates to a device for manufacturing of blanks made of plate-shaped workpieces, in particular sheet metal, with straight and circular arcs Lines of composite contour, in which at least at a factory clearance recording table a cutting element and a guide ruler parallel to the cutting direction and a pivot point mediating clamping device are arranged.

To produce blanks with straight contours from plate-shaped workpieces, it is

² S knows to guide the workpieces along a guide ruler and at a fixed distance from the guide ruler z. B. to cut the workpiece with a scissors-like tool. A strip-shaped blank with a straight contour is obtained.

For the production of a circular arc-shaped blank, devices are known in which a cutting tool is arranged at the free end of an arm rotatably mounted about a vertical axis. the end a plate-shaped workpiece mounted above or below the rotary arm can in this way a circular blank can be made.

To produce a blank that has both straight and arcuate contours, it is but hitherto necessary to process the plate-shaped workpiece one after the other in the device described. The workpiece must therefore be transported from one device to the other.

It is also possible to make the cut at once; this can e.g. B. with a hand-operated Hand cutting device done, which is guided along the contour to be cut through the workpiece will. This has the disadvantage that deviations from the contour to be cut can occur and that the production of such blanks is very slow and expensive. With this method, only one Cut to be performed at the same time, it is z. B. not possible to run parallel contours at the same time cut.

A device for producing blanks of any desired line layout is also known (DT-OS 21 36 267), in which a horizontal runway for the Longitudinal feed of a sheet is arranged and in which the circular knife scissors around one through the cutting point extending vertical axis is pivotable and displaceable transversely to the runway. The production a cut of any contour is very difficult because the sheet to be cut is pushed forward at the same time, the circular knife scissors across the

device moved and must be rotated about its vertical axis. So there have to be three different movements cooperate in a suitable manner in order to cut the desired contour can. Here you can

\ deviations from the contour to be cut occur. With this method, too, only one cut can be made at a time, contours running in parallel must be cut one after the other.

It is the object of the invention to provide a Vorrichtur.g for To propose the production of blanks in which a plate-shaped workpiece is guided in such a way that when advancing the workpiece on at least one side of the blank, when running parallel Contours on two sides of the blank, one blank with one straight line one after the other in one operation and contour having circular arc-shaped areas can be produced.

This is achieved by placing one or two on a straight guide perpendicular to the cutting direction Cutting organs are each arranged adjustable in their distance from the pivot point that one in the Sehneidrichtung located behind the tensioning device, in this direction according to the length of one to be executed straight cut adjustable, from the workpiece advanced and the clamping device in Limit switch bringing the clamping position and a second vertically behind the cutting elements in the cutting direction Guide ruler also adjustable for the cutting direction according to the cut length to be performed are provided.

The following description of preferred embodiments of the device according to the invention serves in connection with the drawing of the closer F.r purification. It shows

F i g. 1 is a schematic view of the invention Contraption,

F i g. 2 a plan view of the device according to the invention,

Figure J is a sectional view taken along line 3-3 in Fig. 1,

4 is a partially sectioned cable view of the Clamping device,

F i g. 5 shows a section along the line 5-5 in FIG. 2.

6 shows a schematic circuit diagram of the according to the invention Contraption,

F i g. 7 a blank with parallel contours,

F i g. 8 a blank with non-parallel contours and

F i g. 9 a T-shaped cut.

In the Fi g. 1 and 2, a device for producing blanks according to the invention is shown in perspective and in plan view. It consists of an L-shaped workpiece receiving table 1. Running parallel to the edges of the table 1, it has a slot 2 extending approximately in the middle over almost the entire length of the table. Through this slot, cutting elements 3 and 4 arranged under the table 1 protrude above the level of the table surface. These cutting members 3 and 4 are arranged in such a way that the cutting direction is transverse to the direction of the slot 2. They are displaceably mounted transversely to the cutting direction along the slot 2 and can be locked in any position. The long sides of the slot 2 are formed by edge surfaces 2: i and 2b which run downwards at an angle.

This allows a platelike workpiece to be pushed over the slot without any effort Edge to be held on.

In 1- i g. 3 shows one of the two cutting members 3.4 in a side view. As a cutting organ finds /. B. a commercially available electric sheet metal shears 5 use. The artiee scissors are used in a known manner / .. B. for the production of contours of any shape, whereby they are then guided by hand ». The scissors can also be driven differently, e.g. B. by a pressurized medium, in particular a pneumatic Moior. In the preferred embodiment of the invention, such scissors 5 are arranged with the cutting head 6 facing upwards on a slide 7 which is displaceable transversely to the cutting direction. This comprises a base plate 8 on which a holder 9 carrying the scissors 5 is mounted so as to be displaceable perpendicular to the base plate 8. For this purpose, a piston-cylinder unit U is fastened in the base plate 8, the piston 12 of which is rigidly connected to the holder 9. To guide the holder 9, a guide member Π firmly connected to the base plate 8 is provided. By actuating the piston-cylinder unit 11, the distance between the holder 9 and thus the scissors 5 and the base plate 8 can be changed.

The base plate 8 is mounted below the workpiece receiving table I that the cutting head 6 of the In the upper position, scissors 5 protrude through slot 2 just above the level of the table top, that the cutting head for a plate-shaped workpiece advanced on the table surface exactly in Cutting position is. In the lower, lowered position is the cutting head 6 below the level of the table surface, so that a workpiece on the Table surface and the slot 2 can be pushed without being obstructed by the cutting head 6.

In order to be able to guide the carriage 7 along the slot, two are parallel to below the slot This extending guide rails 14 and 15 are provided. The one guide rail 14 preferably has has a circular cross-section and is arranged so that it is approximately below the center of gravity of the carriage 7 lies. On the underside of the base plate 8 of the carriage 7 is a horizontal guide rail 14 comprehensive guide bushes 16 that are firmly connected to the base plate are provided. To reduce the Friction between the sleeve 16 and the rail 14 is the sleeve 16 in a known manner, for. B. as a ball bushing educated. The second is to secure the slide 7 against twisting around the guide rail 14 Guide rail 15 is provided, which in F i g. 3 is a rectangular embodiment shown Has cross-section, but can also have other cross-sections. Retaining members attached to the base plate 8 17 and 18 embrace them on their top and bottom. The guide rails 14 and 15 are positioned so that that the cutting head in the raised position of the scissors 5 in the manner described in Discrimination position is. As in Fig. 3 is shown, it may be necessary to the base plate 8 of the carriage 7 against to lead the horizontal inclined.

In order to fix the carriage 7 against lateral displacement, there is 8 on the base plate a bearing block 19 is arranged. On this is a two-armed lever 21 with a long and a short one Arm rotatably mounted about a horizontal axis 22. The long arm is at its free end from one Stop 23 is supported, which is rigidly connected to the bracket 9 carrying the scissors 5. When lifting and Lowering cVr bracket 9 by actuating the piston-cylinder unit 11 is the lever around the Axis 22 pivoted. The bearing block 19 is positioned so that when pivoting the long lever arm upwards the short lever arm downwards against the

Guide rail 15 is pressed. This will make the Lateral displacement of the carriage 7 is prevented when the holder 9 and the scissors 5 are raised Position is. If the bracket and the scissors 5 against it are lowered, the long lever arm is pivoted down by the weight of the lever and the short lever arm is lifted off the guide rail 15. Then the carriage is along the guide rails 14 and 15 can be moved freely.

To increase the contact pressure, a screw 24 is arranged on the underside of the short lever in such a way that that it is pressed against the guide rail 15 when the scissors 5 are raised. Because of the small area of the screw head, the contact pressure is increased, and by turning the screw the contact pressure can be varied.

A pointer 25 is fixedly connected to the holder 9, the free end of which is positioned above a scale 26 arranged on the inclined edge surface 2b of the slot 2. This allows the exact position of the carriage 7 to be read on the scale 26 and adjusted.

The housing of a roll meter known per se can be attached to the cutting element 3. The tape measure is can be pulled out in the direction of the other cutting element 4, so that the distance between the two Cutting organs can be measured directly. When you let go, the tape measure is held back by a spring withdrawn into the housing and rolled up there.

It is beneficial to attach the beginning of the tape measure to the other cutting member 3 so that the tape measure when moving one of the two cutting elements pulled out of the housing by itself or in this is withdrawn. As a result, the distance between the cutting members 3, 4 can be easily adjusted at any time can be read immediately.

The two cutting elements 3 and 4 are constructed in exactly the same way, they are in the same guide rails 14,15 guided parallel to each other.

On the side of the slot 2 opposite the outside of the table 1 is a clamping device 27 (Figs. 2 and 4). It comprises a vertical piston-cylinder unit arranged above the table surface 28, the cylinder 31 of which is firmly connected to the workpiece receiving table 1 by a holder 29 is. The actuation of the piston-cylinder unit 28 takes place in the same way as the actuation of the piston-cylinder units 11 of the carriage 7 preferably pneumatically or hydraulically.

The piston 33 of the unit 28 is at its lower, free end = with a around the vertical axis rotatable turntable 34 is provided. For this purpose, a sleeve 35 is screwed onto the piston, in which the The turntable 34 is mounted on the turntable 34 by means of a ball bearing 36 to reduce friction exactly opposite another is embedded in the table top in a ball bearing 37 around the vertical Axis rotatably mounted turntable 38 arranged The upper surface of this lower turntable 38 protrudes a small amount over the table surface; the edges of the two turntables 34 and 38 are bevelled to make it easier to insert the plate-shaped workpieces between the turntables.

In the raised state, the piston 33 and thus the upper turntable 34 are so far above the lower turntable 38 that the plate-shaped workpiece pushed effortlessly between the two turntables can be. In the lowered state, the two turntables 34 and 38 dress the workpiece /. wipe each other firmly, creating a pivot point 39 for the workpiece. This can no longer be pushed forward between the turntables, but only need to be rotated around the common axis of rotation of the two turntables.

The clamping device 27 is positioned so that the pivot point 39 is exactly on the extension of the line lies, which connects the Arbcitpunkte the cutting heads 6 of the cutting members 3, 4, so the points at which

ίο the cutting of the workpiece takes place.

It is also possible not to provide the lower turntable 38, the workpiece is then pressed directly onto the table surface by the upper turntable 34.
In the cutting direction behind the clamping device 27, a further slot 41 is provided in the table top, running parallel to the cutting direction. A limit switch 42, which can be moved along the side, is arranged in it, which, like the carriages 7, is guided by means of a guide bushing and guide members on two guide rails 43 and 44 running below the table surface parallel to the slot 41. The limit switch 42 is actuated in that a workpiece advanced in the cutting direction touches a switching lever of the switch. For this purpose, the limit switch 42 is mounted below the table top in such a way that its sound lever protrudes through the slot 41 over the table surface and can thus be actuated by the workpiece being advanced. The actuation causes the piston 33 of the clamping device 27 to be lowered, that is to say, the clamping device 27 is brought into the clamping position. The limit switch 42 is designed so that, after the switch has been actuated, the workpiece can be advanced further over the slot 41 and the limit switch 42 without being hindered by the latter. As a switch z. B. a pneumatic spring rod valve.

The limit switch 42, which can be moved on the guide rails 43 and 44, is through a mechanical connection, z. B. a rod 45 connected to a control button 46, which is from the operating side of the table can be operated from. He is z. B. in a horizontal running slot of the table side wall and can be determined in this slot. A scale 47 arranged on the table 1 shows the position of the button 46 and thus the position of the limit switch 42 at.

In the cutting direction behind the clamping device 27 and on the side opposite the slot 2 of the slot 41, a further slot 48 running parallel to the slot 2 is provided in the table top. In this slot 48 is a bearing block 49 in a similar manner to the carriage 7 and the limit switch 42 by means a ball bushing on a guide rail 51 with a circular cross-section along the slot 48 movably mounted

On both sides of the bearing block 49 is a horizontal one Levers 52, 53 mounted pivotably about a horizontal axis 54. These carry at their free ends a guide ruler that runs parallel to the cutting direction and is arranged above the table top 55.

This is due to the rotatable mounting outside the center of gravity of the guide ruler 55 Guide ruler 55 always tightly on the table top due to its weight. This is unnecessary also a second guide rail for the bearing block 49, as used in the management of the limit switch 42 and the Cutting organs 3.4 are necessary.

ΛK I guideline 55 can ζ. B. an angle rail Find use. Form the vertical leg then on the side of the guide lens 55 facing the slot 41, a firmly resting on the table top Guide for a plate-shaped workpiece.

According to the invention, there is a fixed relationship between the position of the limit switch 42 and the position of the guide ruler 55. The distance of the limit switch 42 from that through the pivot point 39 transversely This is because the line running to the cutting direction is the same size as the spacing of the guide ruler 55 from the line running through pivot point 39 parallel to the cutting direction. As in detail later is described, the inventive device is in maintaining such a fixed relationship suitable for making circular arc cuts over an angle of 90 °.

In order to ensure the fixed relationship of the position of the limit switch 42 and the guide ruler 55, is a mechanical coupling of the sliding movements of these two parts along the corresponding guide rails intended. For this purpose, a horizontally circulating chain 56 is arranged below the table top, by means of deflection rollers 57, 58, 59 both parallel to slot 41 and parallel to slot 48 is performed (Fig. 2). The Knd switch 42 is with the help of a holder 61 is connected to the Cette 56, as is the bearing block 49 in the middle !. of a similar holder 62 (Fig. 5).

When the limit switch 42 is moved by the control button 46, the chain 56 is around the pulleys 57, 58, 59 drawn. At the same time, the bearing block 49 and thus the guide ruler 55 are longitudinal of the slot 48 moved. This is a clear mechanical coupling of the limit switch 42 and the Guide rulers 55 guaranteed.

In the cutting direction in front of the fulcrum 39 there is a side of the slot 41 facing away from the slot 2 Guide ruler 63 running parallel to the cutting direction is arranged. In the preferred embodiment (Fig. 2) this is firmly connected to the table 1, but it can also be displaced perpendicular to the cutting direction and be designed to be lockable.

On the operating side of the table, switches 64 and 65 for switching the scissors 5 on and off are provided. In addition, there is a valve 66, 67 for actuating the corresponding piston-cylinder units for each cutting element 11 provided. To release the clamping device 27, i. H. A foot switch 68 is used to raise the piston 33.

In Fig. 6 a circuit diagram is given schematically, as for the pneumatic operation of the piston-cylinder units 11 of the slide 7 and the piston-cylinder unit 28 of the clamping device 27 is used.

The raising and lowering of the cutting members 3 and 4 controlling, e.g. B. pneumatic valves 66 and 67 are operated by hand; In one position the pistons in the unit 11 are lowered (shown in Fig. 6), in the other position the pistons are raised (not shown in FIG. 6).

By actuating the limit switch 42, the valve 69 is switched over by applying compressed air and thereby the piston 33 of the unit 28 of the clamping device 27 is lowered Foot switch 68, the valve 69 is pushed back into its starting position, so that the piston 33 of the Aggregates ^ is raised again.

The limit switch 42 is actuated by the workpiece being advanced. If you move the Workpiece, it remains permanently actuated, since the workpiece moves over the limit switch 42 during the rotary movement is advanced. It would be impossible to relax the tensioning device 27 by actuation of the foot switch 68 to reach. Therefore, there is a delay element between the limit switch 42 and the valve 69 71 installed. A short time after the valve 69 has been switched over by the limit switch 42 is, the effect of the limit switch 42 is canceled by this delay element 71, d. H. the loading the valve 69 with compressed air is terminated. The valve 69 then remains in its clamping device for so long 27 held in the clamping position until it is switched again by the foot switch 68. The delay element 71 consists of a delay line 72 and a valve 73. When actuated of the limit switch 42, compressed air is applied not only to the valve 69, but also to the delay line 72. This allows the compressed air to pass slowly, so that the compressed air only occurs after a certain time at which the delay line 72 following valve 73 is applied and this moves, whereby the limit switch 42 leading to the valve 69 compressed air line is vented and the opening of the valve 69 terminated will. As soon as the limit switch 42 is relieved again, the valve 73 is returned to its starting position by a spring pushed back so that when the limit switch 42 is actuated again, compressed air is again applied to the valve 69 can work.

With the device according to the invention, blanks can be produced whose contours are straight and have circular arc-shaped contours extending over 90 °. Find such blanks from sheet metal z. B. in elbow pieces and branch pieces of ventilation ducts use. In the F i g. 7 through 9 are examples shown for blanks that can be produced with the device according to the invention.

In the cut of FIG. 7 the contours run parallel. The blank has a linearly delimited area of length b. an adjoining circular arc-shaped area and an adjoining rectilinear area of length a . The outer radius of the circular arc-shaped area is denoted by R, the smaller radius by r. Both arcs have the same center point M. The width of the blank is denoted by c , the width c being the difference between the radii R and r .

To produce the blank of FIG. 7, the procedure is as follows: By actuating the valves 66 and 67, both cutting members 3, 4 are lowered. In this position they can be moved freely along the slot 2. The cutting element 4, which is closer to the pivot point 39, is moved into a position distant from the pivot point 39 by the distance corresponding to the radius r , and the other cutting element 3 is moved into a position distant from the pivot point 39 by a distance corresponding to the radius R. The two cutting elements are then raised into the upper position by actuating the valves 66 and 67. As a result, they are clamped in the manner described on the guide rail 15 and secured against lateral displacement.

As a second step, after releasing the control button 46 by actuating it, the limit switch 42 and the guide ruler 55 brought into a position in which the limit switch 42 of the by the Point of rotation 39 parallel to the slot 2 running line

has a distance corresponding to the length b. In the manner described above, the guide ruler 55 is automatically shifted, so that its distance from the line running through the pivot 39 perpendicular to the slot 2 is also given by the length b . In this position, the control button 46 is fixed again in order to secure the limit switch 42 and the guide rule 55 against further displacement.

If the guide ruler 63 is designed to be displaceable, it is displaced in such a way that it is removed by the length α from the line running through the fulcrum 39 perpendicular to the slot 2. If this guide ruler 63 is not designed to be adjustable, then the length a is determined by the device; With such a device, only blanks with a fixed length a can then be produced.

After turning on the scissors 5 with the switches 64 and 65, a z. B. a rectangular, plate-shaped workpiece with one side applied to the guide ruler 63 and advanced in the cutting direction. A strip with straight contours of width c is cut by the two cutting members 3 and 4. As soon as the workpiece has been advanced by the length b , it hits the limit switch 42 and actuates it. As a result, the piston 33 and the associated rotary plate 34 of the clamping device 27 are lowered onto the workpiece and clamps it between the upper rotary plate 34 and the lower rotary plate 38. When the workpiece is moved further, it rotates about the pivot point 39; the cutting members 3, 4 perform circular arc-shaped cuts with the radii r and R. As soon as the workpiece has been rotated through 90 °, its front edge hits the guide ruler 55. By operating the foot switch 68, the tensioning device 27 can be released again in the manner described above. When the workpiece is advanced further along the guide ruler 55, a further section with straight contours of length a is cut off. The result of the cutting process described is a blank as shown in FIG.

In Fig. 8 shows a blank with non-parallel contours. The outer contour consists of a straight piece of length Sl, a circular arc-shaped piece with radius Ri around the center Ml and another straight piece with length Ai. In a similar way, the inner contour shows a straight piece of length B1, a circular arc-shaped piece with radius RT. around the center Ml, which differs from Ml, and an adjoining straight piece of length Ai.

These contours are cut on the device according to the invention in two successive operations. For this purpose, the cutting members 3 and 4 are set to the distance Ri or R2 from the pivot point 39 in the manner described above.

In the first step, only the outer contour is cut. For this purpose, the further away from the pivot point 39 is Cutting element 3 raised in the working position, but the other cutting element 4 is lowered. The limit switch 42 and thus the guide ruler 55 are set to a distance corresponding to the length ßl. In In exactly the same way as described above, the workpiece is first attached to the guide rail 63 pushed along, when reaching the limit switch 42 clamped in the clamping device 27 and around the pivot point 39 rotated. After a quarter turn of the workpiece, the clamping device 27 is through Pressing the foot switch is released again and the workpiece is advanced further along the guide ruler 55.

The second contour is cut in exactly the same way. The cutting element 3 further away from the pivot point 39 is lowered and the cutting element 4 located closer is raised. The limit switch 42 and the guide ruler 55 are set to the length B1 .

It is important that the outer contour is cut by the inner contour, because it is when cutting the inner contour of the section of the workpiece that is clamped between the turntables 34 and 38, is separated from the workpiece.

In a similar way, blanks can be produced as shown in FIG. 9 are shown. These too Contours are cut one after the other. A cutting element is set to the distance S3 or ß4 set and the workpiece advanced in the manner described.

By adjusting the guide rail 63, the distances A3 and A4 can also be set as desired.

It is an advantage of the device according to the invention that the cutting of contours that contain straight and circular arc-shaped sections with a Tool can be carried out in one operation.

In addition 5 sheets of drawings

Claims (13)

Patent claims: 1. Apparatus for the production of blanks from plate-shaped workpieces, in particular sheet metal, with a contour composed of straight and circular arc-shaped lines, in which at least one cutting element and a guide ruler parallel to the cutting direction as well as a pivot point are arranged on a workpiece receiving table, d a characterized in that one or two cutting members (3, 4) are arranged on a straight guide (14, IS) perpendicular to the cutting direction, each adjustable in their distance from the pivot point (39), that one located in the cutting direction behind the clamping device (27) , in this direction according to the length of a straight cut to be performed, adjustable limit switch (42) actuated by the advanced workpiece and bringing the clamping device (27) into the clamping position, as well as a second limit switch (42) in the cutting direction behind the cutting elements (3, 4), perpendicular to the cutting direction, likewise according to the to be executed A guide ruler (55) that can be adjusted to the cutting length is provided. 2. Device according to claim 1, characterized in that that the cutting members (3, 4) are designed as motorized scissors (5) that can be switched on and off are. 3. Apparatus according to claim 1 or 2, characterized in that the cutting members (3, 4) optionally can be lowered below the level of the table (1). 4. Apparatus according to claim 1, 2 or 3, characterized by a clamping device (19, 21, 23) for automatic clamping of the cutting elements (3, 4) in the set position when lifting over the table level. 5. Apparatus according to claim 4, characterized by a two-armed lever (21), one of which Arm by a stop attached to the cutting element (3, 4) and acting on the other lever arm (23) is pressed against a guide rail (15) when the cutting element (3, 4) is raised. 6. Device according to one of the preceding claims, characterized in that the Clamping device (27) actuated by pressure medium and the limit switch (42) designed as a pressure medium valve is. 7. Device according to one of the preceding claims, characterized in that the limit switch (42) by a mechanical operating element (45) from the operating side of the table (1) is adjustable. 8. Device according to one of the preceding claims, characterized in that the guide ruler (55) is pivotally mounted on levers (52, 53) about a horizontal axis (54) and through its own weight rests tightly on the table (1). 9. Device according to one of the preceding. Claims, characterized in that the adjustment movements the limit switch (42) and the guide ruler (55) are coupled to one another. 10. Apparatus according to claim 9, characterized in that the coupling of the adjustment movements takes place by a chain drive (56). 11. Device according to one of the preceding claims, characterized by a further, in Cutting direction arranged in front of the cutting members (3, 4) and running parallel to the cutting direction Guide ruler (63). 12. The device according to claim 11, characterized in that that the guide ruler (63) is displaceable perpendicular to the cutting direction. 13. Device according to one of the preceding claims, characterized in that the Cutting elements (3, 4), the limit switch (42) and the guide rulers (55, 63) with roller bearings on guide rails (14, 43, 51) are slidably mounted.