These testing machines (type BUP) are used to determine and evaluate sheet metal properties.
Typical test methods include Erichsen cupping tests (EN ISO 20482), in which a hemispherical punch is pressed into a clamped test piece until a crack appears. There is no in-flow of the sheet metal.
The drawing formability of the sheet metal is determined from the punch penetration depth. Another test method frequently used is the earing test to EN 1669. In this test circular blanks are punched or inserted and drawn into cups (metal in-flow). The deep-drawing characteristics of the metal are determined via the percentage ear height ratio.
Other metal-forming test methods include square cup tests, hole expansion tests, FLC tests and bulge tests.
Key Advantages and Features
- Fast, easy tool and fixture changes, including drawing-punch, drawing-die, blank-holder, cutting-punch, cutting-ring and scraper-ring. Numerous modular expansion options.
- Test tools/fixtures from earlier-generation machines can still be used (with some restrictions). Test tools/fixtures for established test methods available 'off-the-shelf', special tools/fixtures on application.
- Low piston-cylinder friction enables accurate measurement recording and excellent reproducibility.
- Clean and quiet in operation. Easily transportable thanks to compact design.
- Hydraulic cup-extractor via integrated piston, with piston rod acting through drawing-punch.
- Electronics can be swiveled to optimum viewing angle for measured values.
- Conveniently positioned controls.
- Electrical and hydraulic protection for all functions.
- Adjustable automatic blank-holder unloading during test enables cup-drawing without crushing ear.
- Automatic setting of pre-selected clamping force after blanking procedure.
- Automatic piston withdrawal and switch-off after end of test due to crack detection or on reaching maximum ram stroke (s-limit).
- Swing doors and removable casing panels for easy access to components.
- Open design allows multiple tests to be performed on long sheet-metal strips without the need to open and close the tool head.
- No unpleasant odors thanks to closed oil-circuit.
- Special solutions (e.g. piezo load cell, different deep drawing speeds, separate hydraulic power-packs etc.) are available on request.
- Change deep drawing speed during test (BUP 400 / 600 / 1000).
- Operating-mode switch for automatic or manual operation (BUP 400 / 600 / 1000).
- Two-handed operation eliminates risk of accident when closing the manual tool head of the BUP 100/200 (e.g. falling due to accidental jolt).
- Hydraulic opening and closing of tool head, with 2-handed operation (BUP 400 / 600 / 1000).
- Setup stroke for easy tool/fixture change (BUP 400 / 600 / 1000).
Sheet Metal Testing Machines
Earing tests - In the earing test cups are drawn from metal sheets and the earing formation at the edges of the cups is evaluated.
Forming limit curves (FLC) - The test to determine the change in forming limit is used to test the maximum multiaxial ductility of sheet metal.
Erichsen cupping tests (EN ISO 20482) - In cupping tests on sheet metal a spherical drawing punch is pressed into a clamped metal sheet until a crack appears. The cupping test is used to assess drawing formality.
Hole expansion tests - In the hole-expansion test, metal strip containing a hole is clamped round the outer edge and the metal is deep drawn until a crack appears.
Zwick Sheet Metal Testing - Erichsen- / Cupping Test