GB2023474A

GB2023474A - Process for producing heated severed portions for die forging

Info

Publication number: GB2023474A
Application number: GB7909155A
Authority: GB
Original assignee: KROESBACHER STAHLWAREN FRANZ
Current assignee: KROESBACHER STAHLWAREN FRANZ
Priority date: 1978-03-24
Filing date: 1979-03-15
Publication date: 1980-01-03
Also published as: FR2420381B3; ATA212178A; AT351337B; FR2420381A1; DE2911048A1; DE2911048C2

Abstract

A process for producing heated severed portions, which serve as blanks for die forging, wherein bars (1, 1') of material are fed successively to a heating means (2), preferably a medium-frequency induction heating means, wherein, before entering the heating means (2), each following bar (1, 1') is welded to the preceding bar (1) to form an endless line (3), in a welding means which is disposed upstream of the heating means, which line (3) of bars is separated into the severed portions, after issuing from the heating means (2). <IMAGE>

Description

SPECIFICATION Process for producing heated severed portions for die forging The invention relates to a process for producing heated severed portions for die forging, wherein starting material in bar form is heated before the severing operation, and apparatus for carrying out the process.

The most suitable starting material for die forging are so-called severed portions which are severed in the required shape from plates or bars.

The severed portions must be fed to the forging die, in a heated condition. However, uniformly heating the severed portions in conventional oil or gas furnaces gives rise to difficulties due to the severed portions oxidising or sticking together in the furnace, or such heating also gives rise to economy problems, as the degree of efficiency of the furnaces is poor.

Electrical heating of the severed portions, such as induction or resistance heating, is difficult, as the severed portions are not generally of a uniform cross-section, and thus have regions at different temperatures. Attempts have already been made to heat the starting bar material in a conventional furnace, and only then to severe the severed portions, and feed them to the forging die. In order to achieve a continuous mode of operation in this process, a plurality of bars are heated in the furnace at the same time, and each bar is fed to the severing device in succession, a respective severed portion is severed from the bar, and the bars are then returned to the furnace, heated, fed to the severing device, where a further severed portion is severed from each bar.A relatively complicated conveyor system is required for this process, in which in addition a conventional furnace is used. However, continuity in the mode of operation of this process is interrupted when the bars placed in the furnace have been used up, and the next group of bars must be fed to the furnace. Finally, a portion which cannot be used remains at the end of each bar.

The problem of the invention is that of providing a process and apparatus of the kind set out above, which permit continuous operation, with uniformly heated severed portions, while eliminating waste portions.

According to the invention, this is achieved in that the bars of material are fed successively to the heating means, wherein, before entering the heating means, each following bar of material is welded to the preceding bar to form an endless line which is separated into the severed portions after issuing from the heating means.

Connecting the individual bars before they are heated, to form an endless line, permits rapid, continuous operation as no interruptions can occur due to the treatment of individual bars and there are no waste portions remaining from individual bars, which waste portions would cause an interruption in the procedure, in order for them to be removed from the process. Welding the successive bars together also makes it possible for the feed means to be arranged not in the region of the heating means but upstream thereof.

The process according to the invention also makes it possible, by virtue of the continuous nature of the feed movement and the mode of operation, to use electrical heating means, for example medium-frequency induction heating means, as the line of bars to be heated is of uniform cross-sections, so that it is also possible to make use of the other advantages of electrical heating, such as good efficiency, low degree of oxidation, lack of environmental pollution and the like. A further advantage is that it is possible to convert the process to producing severed portions of a different size, and thus different forged articles, solely by altering the severing means, while the heating means itself remains unchanged.

The apparatus for carrying out the process according to the invention is characterised in that a welding means is disposed upstream of the electrical heating means.

The invention will now be described in greater detail hereinafter with reference to the accompanying drawings, without however being limited thereto. Likewise, the reference numerals set out in the appended claims do not denote any limitation of the invention but are provided only to facilitate idenfifying the relevant components in the drawings.

Figure 1 shows a diagrammatic side view of apparatus according to the invention, Figure 2 shows a plan view of the apparatus of Figure 1, and Figure 3 shows a plan view of the line of bar material, from which a severed portion is cut off.

An operating line 7 which is suitable for carrying out the process according to the present invention has a storage means 10 for the starting material, the bars 1', from which the bars are fed by feed means 6, 6' to the electrical heating means 2, preferably a medium-frequency induction heating means. Arranged upstream of the heating means 2 is a welding means 4 by means of which the trailing end of a bar 1 of material which has been introduced into the heating means 2 is welded to the leading end of the next following bar 1', to form an endless line of bars 3.After leaving the heating means 2, the heated bars 3 pass to a severing means 8 which is disposed directly downstream of the heating means 2 and in which the bars are separated off to form severed portions 11 (Figure 3) which are fed to the forging die 5 for shaping and which leave the forging die again, for example by way of a conveyor belt 9. Welding the bars together to form an endless line 3 permits a continuous feed movement go that the electrical heating means 2, the servering means 8 and the forging die 5 can be kept in operation without the interruptions which were hitherto necessary, so that it is possible to achieve a significant increase in the number of forged articles, with better operating costs.

If the bars 1 and 1' are welded together properly and skillfully, it is even possible for severed portions 11 which include the join region to be readily passed to the forging die 5. Severed portions 11 from the join region, which suffer from defective welding, can be extracted from the process either on the way from the severing means 8 to the forging die 5 or possibly after leaving the forging die in a forged condition.

Claims

1. A process for producing heated severed portions for die forging in which bars of starting material are fed successively to heating means and before entering the heating means, each following bar of material is welded to the preceding bar to form an endless line which is separated into severed portions after issuing from the heating means.

2. A process according to claim 1, in which the line of welded bars is fed to a medium-frequency induction heating means.

3. A process for producing heated severed portions for die forging, substantially as hereinbefore described with reference to the accompanying drawings.

4. Apparatus for carrying out the process according to claim 1, including an electrical heating means, severing means disposed downstream thereof, and a welding means disposed upstream of the electrical heating means.

5. Apparatus for carrying out the process according to claim 1 substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.