DE2336474A1 - Overload protector for tools and presses - responds to multiple loading or faulty functioning of drawing process - Google Patents

Abstract

This protector is used mainly for fitting into a press tool used for cutting and drawing and for trimming deep drawn containers. Contactless initiators under one arm of the double arm levers transmit contacting signals to an electronic system which in turn actuates the solenoid valves of the press clutch and brakes for stopping the press. The strip holder has a pressure sensing pin which is pressed down excessively if more than one sheet strip is inserted and this excessive travel is transmitted to the one arm of the actuating lever which in turn actuates the initiator. In addition to the above, pressure sensitive segments are excessively displaced in the case of excessive amount of strip material between the dies and this once again actuates the other lever for triggering the initiator.

Description

DR. MÜLLER-BORG DIPL.-PHYS. DF .. MAN ITZ DIPL.-CHEM. DR. DEUFEL

DIPL.-ING. FiNSTERVMLD DIPL.-IN6. GRÄMKOW

PATENT LAWYERS

33 Braunschweig, July 16, 1973 W / MB / Sch - K 826

KARGES-HAMMER-MASCHINEN GmbH & Co. KG 33 Braunschweig, Frankfurter Str. 36

Tool and press overload protection

The invention relates to a tool and press overload protection device, mainly suitable for installation in tools for cutting and drawing as well as edge trimming of drawn cans, with which at a multiple material feed or one that does not function corresponding drawing process, the press comes to a standstill.

With such tools for cutting and pulling as well as edge trimming of drawn cans, it is necessary to provide a tool safety device that prevents the tool from being overloaded in the case of multiple material feeds protects.

It is also necessary to design the tool lock in such a way that that the function of the drawing process is monitored and, if necessary, the press in the event of creasing or when a can is torn off turns off.

It is known to use overload protection devices to meet these requirements to be attached to presses. A distinction must be made between

1. Immediately acting fuses and

2. indirectly acting securing devices.

So-called crushing pots or crushing plates are used as immediate safeguards used as break protection in the press ram. The disadvantage, however, is that when determining the static breaking load, the shear strength the material and the shear surface must be related. Due to the variation within the material strength the breaking loads cannot be precisely determined.

At the same time, the disadvantage must be accepted that in use von Brecht Pots a so-called setting of the material and thus a game occurs after a short time.

409886/0841

Dr. Müller-Bore Dr. Manitz Dr. Deufel ■ Dipl.-Ing. Finsterwald Dipl.-Ing. Grämkow

Braunschweig, Am Bürgerpark 8 8 Munich 22, Robert-Koch-Strasse 1 7 Stuttgart-Bad Cannstatt, Marktstrasse

Telephone (0531) 73887 _Te | _e fon (0811) 293645, Telex 5-22050 mbpat

Bank: Central Cash Office Bayer. Volksbanken, Munich, account number 9822 Post check: Munich 95495

Hydraulic overload protection devices are also known, which are equipped with valve plates or with pressure limiting valves are. The oil pressure is preloaded in a cylinder; in the event of an overload, the valve disc lifts off the seat and the oil pressure will be dismantled.

Mechanical overload switches are used for the indirect fuses used. Here, the pressing force is transferred to a lever system with the corresponding expansion and electrical switches actuated. The disadvantage, however, is that the switching point changes due to the inertia of the system. Furthermore, they are almost inertialess Overload protection known, which has strain gauges or electrical path measurements are working. However, this system also requires that the press body be stretched must in order to be able to remove a switching contact.

Bibliography about press locks:

1. Manual for non-cutting shaping k. Extended edition from Schuler AG in Göppingen;

2. VDI reports No. 1 ^ 8 punching technology VDI-Verlag Düsseldorf;

J. MaschiBrenmarkt Industrie journal No. 90 Vogel-Verlag Würzburg
Article about the press with self-regulation.

The invention is based on the object of a tool and press safety device to create, in the case of double sheet feeding or a drawing process that does not correspond to the function, neither that If the tool is overloaded, the press body is still stretched.

This object is achieved according to the invention in that in tools suitable for cutting and pulling as well as edge trimming of drawn ones Can initiators are used, which are controlled via levers

409886/0641

2336m

pass the switching contact on to electronics without making any contact and thereby switch solenoid valves of the press clutch and brake so that the press comes to a standstill.

The advantages achieved with the invention are in particular: that the tool cannot be overloaded and that there is still no stretching of the press body.

An embodiment of the invention is shown in the drawing and described below.

The drawing shows a section in the starting position as well as in the end position of a working stroke of a tool for cutting, pulling and edge trimming of drawn cans. The tool and press overload protection is designed in such a way that an initiator 2 is adjustably fastened in the lower part 1, which is actuated without contact via the sheet metal holder and a pressure pin k as well as a lever mechanism 5 when between the cutting punch 6 and sheet metal holder 3 a double sheet is located.

Activation of the initiator 2 is also guaranteed if a pulling process that does not correspond to the function .Igt by itself Form creases on the sheet metal, for example due to insufficient sheet metal greasing or insufficient sheet holding pressure.

In the upper part 7, as in the lower part 1, an initiator -8 is attached, which is controlled without contact via the drawing bell 9, pressure segments 10, disk 11 and a pretensioned pressure bolt 12 as well as a lever mechanism 13 and thereby immediately stops the press in the manner described, if there is a double sheet in the drawing gap between the drawing bell 9 and the drawing punch I ^ or the drawing bell 9 is pushed upwards due to the formation of folds on the sheet.

The initiator 8 is also activated when there is between the

409886/0641,

-k-

upper surface of the drawing punch lh and forming punch 15 is a double sheet.

The forming punch I5, which is upward through an elastic Ring l6 is spring-loaded and does not touch the pressure segments 10 during the normal drawing process, gives way to the existing double sheet from above, lifts the pressure segments 10, the disk 11 and the pressure bolts 12, so that a pressure bolt 12 corresponding to the Lever mechanism I3 controls initiator 8.

The control pulse from initiators 2 or 8 is passed on until electronics switch the solenoid valves, the press coupling releases and the brake is applied, so that the press comes to a standstill.

The tool and press overload protection, preferably installed into a tool for cutting and pulling as well as edge trimming of drawn cans, remains in the rest position during the normal workflow and thus guarantees optimal wear resistance.

409886/0641 _ ₅ _

Claims (2)

Claims f 1. Tool and press overload protection, which in the event of a Mehxfach material feed or responds to a drawing process that does not correspond to the function, mainly for installation in a tool for cutting and pulling as well as edge trimming of drawn cans, characterized in that using levers (5j 13) contactless activated initiators are provided, which pass on the switching contact to electronics and thereby switch solenoid valves of the press clutch and brake, so that the press comes to a standstill. 2. Fuse according to claim 1, characterized in that a pressure bolt (^ f) is attached to the sheet metal holder (3), which through Double sheet or wrinkling around the respective oversize is pressed further down and via a lever (5) without contact controls an initiator, which is fastened in the lower part of the tool. 3 · fuse according to claim 1 or 2, characterized in that the drawing bell (9) is cushioned by pressure segments (10) and pressure pin ⁽¹ O and one of the pressure pin in double sheet or wrinkling acts on a lever which drives an initiator without contact. H. Fuse according to one or more of claims 1-3 », characterized in that pressure segments (10) are provided which, when double sheet metal is present, are raised between the drawing punch (1 * 0 and forming punch (I5) and in combination the pressure pin (12) and lever (13) 1 as described in spoke 2, control the same initiator. 409886/064 1 Blank page