Impact machine and a method of forming a body

Abstract

The invention concerns an impact machine for forming a body with desired shape of a formable working material through impact action in a forming operation, said impact machine comprising a machine stand (6), an upper unit which comprises either a lower impact unit (3), which comprises a counter-impact device, or a stationary anvil, and a central unit between the upper and the lower units. The central unit (4) comprises one or more carriers (30), each of which containing and carrying one or a plurality of identically equal tool units (32), each of which comprising a die (34) with a mould cavity (46) for the working material (90) intended to be formed, said carriers including at least one carrier which is stationary during the forming operation and which contains at least one such tool unit, and that motion devices (7) are provided for indexing the carrier or carriers in a horizontal plane for positioning the tool units in different function stations (I-V), comprising a forming station (II) and at least one more station.

Description

[0001] The invention concerns an impact machine for forming a body with desired shape of a formable working material through impact action in a forming operation, said impact machine comprising a machine stand, an upper unit which comprises an upper impact unit with an upper ram and an upper punch, a lower unit which comprises either a counter-impact device or a stationary anvil, and a central unit between the upper and the lower unit. The invention also concerns a method of forming a body of formable working material of such a machine.STATE OF THE ART[0002] Impact machines for working by the employment of high kinetic energy are machines for working in the first place metal, such as cutting, punching, and plastic forming of powder components, powder compaction, and similar operations, in which the speed of a ram, which may consist of a press piston, may be essentially higher than in conventional presses. Also polymeric and ceramic working materials can be conceived, as well as vari...

AI Technical Summary

Benefits of technology

[0008] to counteract shock waves from the impact via the machine stand, which in turn makes it possible to use a light carrier in the central unit, and to eliminate heavy bases, which according to prior art have had the purpose of absorbing shock waves,

[0014] to make it possible to manufacture compacted bodies in the machine with desired shape from metal powder, essentially without communicating pores and with such a great strength that they can be pushed out from their mould cavity without being damaged and be moved to a furnace in order, in a subsequent treatment, to be heated to sintering temperature, wherein the powder grains, which were softened and changed as to their shape in the machine, will be welded together (sinter, coalesce) for the achievement of a very dense body with high strength.

Problems solved by technology

The stress on all joints therefore become very large, as well as on sensitive components, e.g. electronic components for controlling those hydraulic valves which usually form parts of impact machines, which may cause a great risk of failure.

Large, unwieldy stands also give rise to problems in connection with service, change of tool unit or of tool insets in the tool unit, changing the height of the impact unit above the tool unit, etc.

Another problem with known impact machines of the said type is that they have a comparatively small production capacity.

This basically is due to the clumsiness of the machines, which makes it difficult to provide the machine with devices which would make a rational production possible.

Therefore, the consolidated body can be comparatively brittle and should be handled carefully, before it has been pushed out of the die and been heated to a sintering temperature in a subsequent operation, so that the individual powder grains from this treatment are caused to completely coalesce, i.e. to weld together.

This is an important application but in no way the only one possible for the impact machine 1.

On the other hand, it takes of course a longer time to first eject the product and then press down the lower punch to its lower position than to perform those operations simultaneously in two different stations.

It can for example take longer time to carefully push out a comparatively large body with a more complicated shape than a small body with a simple geometry.

In view of the fact that the formed bodies can be rather brittle, this solution, however, possibly may be jeopardising, not only because of the action of the removing arm but also because of the shakings which the turntable 30 can be subjected to during the forming operation in the forming station II, when the table is released from said fixation and locking devices.

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