DD270724A1 - DEVICE FOR THE THERMAL FORMING OF METALLIC MATERIALS - Google Patents

Abstract

The invention relates to a device for thermoforming of metallic materials. In order to ensure a material-specific and material geometry dependent subsequent continuous forming, such as annealing, sintering, pressing, rolling, forging, drawing o. Ae., It is an object of the invention to process materials by means of magnetically moved Lichtbogen and using non-consumable auxiliary electrodes, that there is a wide working range between the electric arc power and the forming speed. At least two separate and electrically powered auxiliary electrodes 1; 2, the electric arc power PL is coupled directly via a feed device 7 of the material to be formed 6, the plusgepolten auxiliary electrodes 1; 2, which with each other and against metallic Magnetleitbleche 4 a; 4 b by means of insulating 5 a; 5b; 5 c are electrically isolated, and each auxiliary electrode 1; 2 with its own power source contribute to the invention solution. Fig. 1

Description

For this 3 pages drawings

Field of application of the invention

The invention relates to a device for thermoforming metallic materials by means of magnetically moved arc with auxiliary electrode in order to secure a material-specific and material-geometrically dependent subsequent continuous forming, such as annealing, sintering, pressing, rolling or forging.

Characteristic of the known state of the art

In thermal forming processes, in particular gas-heated or inductive heat sources are used to achieve the material-specific forming Stolltemperatur.

Gas-fired heat sources are not optimal for high-performance forming because the start-up time is too high and the conversion speed is too low when starting up the process. Gas-fired heat sources require a corresponding furnace space for continuous forming. In order to achieve the required heat setpoint temperature, a certain furnace room temperature profile is to be guaranteed, which is achieved by a certain amount and distribution of the fuel and combustion air amount. Errors in this sequence Fuel gas / air flow rate, combustion, heat supply to the kiln lining and the furnace chamber add up to a deviation from the desired setpoint temperature. The actual setting of the true heat input temperature is therefore not perfectly manageable for all temperature ranges.

The size of the gas burner can not be increased arbitrarily, because at the same time the thermal efficiency drops, d. H.

small increases in the forming speed are bought with ever higher fuel gas ¹ · and air quantities.

Also known for the annealing treatment are induction systems. Disadvantages are the costs, the equipment costs and the weight.

Above all, the high investment costs narrow the range of application of this technology.

Object of the invention

The aim of the invention is to stoigern the performance of the forming process while reducing the equipment and energy consumption and to ensure a continuous flow of the forming process even with changes in energy.

Explanation of the essence of the invention

The invention has for its object to work by means of magnetically moving arcs and using non-consumable auxiliary electrodes materials of different geometries such that there is a wide working range between the electric arc power and the forming speed. According to the invention at least two separate and electrically powered auxiliary electrodes are arranged. Oils electric arc power, as the output of the auxiliary electrodes, is gekoppalt directly with a drive a Umformag _tt , egats.

exemplary

The invention will be explained below the embodiment. Mean

Fig. 1: Arrangement of the auxiliary electrodes required for forming

Fig. 2: Forming speed as a function of the arc power Fig. 3: arc-dependent control regime.

According to FIG. 1, two auxiliary electrodes 1; 2 as "twin" are accommodated in a common magnetic coil 3. The two plus-polarity auxiliary electrodes 1, 2 are electrically separated from each other and from the metallic magnetic guide plates 4 a, 4 b by the insulating diaphragms 5 a, 5 b, 5 c a separate current source (not shown) is fed, so that their electrical power for the magnetically moved arcs can be selected differently and independently of one another The drive of the minus-polarized annealed material 6 takes place via the feed device 7.

According to FIG. 2, there are clear relationships between the electric arc power P _L and the forming speed ν _υ with a wide working range as a necessary prerequisite for the controllability of the forming process.

vm

The slope angle or tg = - from the linear (quasi-linear) course of the function is a measure of the

pl

Performance and sensitivity of the tax procedure.

For a continuous automated forming process, two performance criteria are decisive: high forming speed and high availability with a failure rate approaching zero.

These performance requirements are met by using multiple auxiliary electrodes. The separately supplied for each auxiliary electrode electrical energy ensures the failure of an arc for the working capacity of the entire system with the securing dos continuous forming process

 According to Fig. 3, two possibilities are proposed:

When using z. B. two arc after the arc start 8, the full deformation rate 9 is reached after a very short time. In the event of failure of an arc, the reduced forming speed 10 is set in a time-limited manner by the reduced arc output t... Ti. The continuity of the forming process is thus ensured.

The second possibility, when an arc occurs, is to operate the still functioning auxiliary electrode with increased electrical power P1 in order to ensure the full forming speed for a limited time (to ... ti).

Claims (3)

claims: 1. An apparatus for thermoforming metallic materials to process by means of magnetically moving arcs and using non-consumable auxiliary electrodes materials of different geometries such that between the electric arc power and the forming speed is a wide work table, characterized in that at least two separate and mutually electrically powered Auxiliary electrodes (1, 2) whose electrical arc power (P1) is coupled directly via a feed device (7) of the metallic material (6) to be formed. 2. A device for the thermal forming of metallic materials according to claim 1, characterized by plusgepolte auxiliary electrodes (1, 2), which are electrically separated from each other and against metallic magnetic guide plates (4a, 4b) by means of insulating diaphragms (5a; 5b; 5c). 3. A device for thermal forming of metallic materials according to claim 1 and 2, characterized by for each auxiliary electrode (1; 2) own power source.