DE1083555B - Magazining device for a device for inductive high-frequency heating of workpieces made of non-ferrous metal - Google Patents

Description

GERMAN

With the known heating process for the purpose of hot pressing, in which larger quantities are heated by blanks made of non-ferrous metal in a resistance furnace, the heating time is approximately 15 minutes. This long heating time does not allow the blanks to be heated as the metallurgical point of view is necessary. During such a period of time and the necessary Temperature oxidizes the zinc present in most alloys on the surface ("burning"). This results in a depletion of zinc in the surface layer, causing a diffusion of Zinc is produced from the inner to the outer layers of the compact. It finally arises a reduction in the zinc content over the entire cross-section, d. i.e., structure and composition of the starting material are changing, and in the meantime there has been a surface on the surface very thick oxide skin formed.

If the heating time is too long at elevated temperature, the crystals will grow, which has a detrimental effect on the quality of the end product. These changes in structure are easily detectable after the compacts have been polished.

These phenomena occur particularly when small parts made of non-ferrous metal are heated Purposes of hot pressing. These are parts of around 100 g and less, like most of them occur in the watch industry.

It is important that the workpieces under the action of the high frequency in one time brought to the temperature of the best ductility for hot working in less than 20 seconds will.

The workpieces must be fed to the heating process piece by piece at regular intervals and removed after heating and fed directly to the pressing device. The pieces arrive z. B. from a storage container in the area of the inductor. After a short stop in the area of the indicator the further transport to the press tool takes place. Thanks to this even time interval for the Transporting the pieces, it is also possible to control the press in a simple and timely manner.

Due to the short heating time, it is possible to introduce the raw material in the form of a strip or wire or the like into the inductor, where the amount required for a stamping operation is heated. The previous warming up of a certain minimum stock is not necessary. This avoids the risk of scaling.

When work is interrupted, there is never more than one piece at temperature, in contrast to the bis magazine for a device for inductive high-frequency heating

of workpieces made of non-ferrous metal

Applicant:
»PATELHOLD«
ίο Patent utilization & electrical holding

A.-G.,
Glarus (Switzerland)

Representative: Dr.-Ing. E. Sommerfeld, patent attorney,
Munich 23, Dunantstr. 6th

Claimed priority:
Switzerland from October 8, 1956

Oscar Pfaff, Neuenhof,

and Ernst Guyer, Ennetbaden (Switzerland),

have been named as inventors

previous processes, where the furnace always has a certain supply, which is then available for further processing can no longer be used because the workpieces have been exposed to the temperature for too long are.

It is advisable to carry out the heating in two stages. In a first stage the piece with the optimum specific output adapted to the piece dimensions over the largest possible Cross-section brought to the upper permissible limit of the pressing temperature. In a second stage takes place the temperature equalization over the entire cross-section through reheating with reduced high-frequency power.

Both of these processes must be completed in less than 20 seconds. In this For a short time, the workpieces are not affected by the structure.

The invention relates to a magazine device on a device for inductive high-frequency heating of workpieces made of non-ferrous metal for the purpose of hot pressing, the workpieces under the action the high frequency in a time of less than 20 seconds in two stages on the temperature of the the best formability can be brought under flow of two high frequency coils.

009 530/469

The object of purchase consists of a vertical guide tube, into which two lateral tubes lie one above the other Openings holding organs for the workpieces above are inserted alternately and pulled out, wherein the lower holding member is designed as a pin on which the stack workpieces falling into the guide tube, and that the upper holding member is a pressure thumb adjustable in height, which is attached to the second lowest Workpiece can be pressed resiliently in this way laterally. that this and the overlying workpieces on the other Case are hindered, and that a drive mechanism is provided, which alternates between the two holding members in the holding position or with a time delay in the release position.

For the movement of the holding members, one-sided pressure pistons actuated with compressed air are advantageous used, which are controlled alternately by means of valves. Under the compressed air pressure the organs are brought into the holding position relatively quickly during the releasing backward movement takes place by a correspondingly dimensioned return spring with a desired time delay.

The figure shows one embodiment of the invention shown.

1 is a vertical guide tube. This is in communication with a storage container 2 from which the workpieces 3 to be glowed continuously into the guide tube by means of a corresponding mechanism be filled. Overfilling of the guide tube is prevented by the monitoring element 4.

On the guide tube there are two lateral openings 5 and 6, one above the other lower opening 5, a pin 7 can be pushed into the guide tube as a holding member. Pieces that made the container 2 come and fall through the guide tube are pushed in by the pin 7 And a number of these pieces pile up. This roughly always the same number is monitored by organ 4. A pressure thumb 8 can be inserted through the upper opening 6. This pressure thumb is attached to a lever 9 which can be pivoted about the pivot point 10. The pressure thumb 8 is adjustable in height, huh? done so that the thumb is the second from the bottom Piece can press against the inner wall of the guide tube. The pressure is applied via an elastic intermediate link 11 by the piston 12 of a compressed air cylinder 13. By pressing the second from the bottom This piece and the pieces above it will be prevented from falling further if the piece below Piece falls down because of the receding pin 7. The pin is on the piston 15 of the press cylinder 16 fastened by means of the clamping piece 14. The pen goes back after stopping of the pressure in the plunger 16 with a desired time delay, which by a corresponding Dimensioning of the return spring and the throttling of the air outlet is determined, whereby the The workpiece is released with a delay. The return of the piston 12 is also delayed in the same way.

The pressure cylinders 13 and 16 are connected to control valves 17 and 18. These will take turns magnetically controlled. The pistons and thus the holding organs run rapidly into the air inlet Holding position while the pieces continue to fall when the air pressure ceases with a time delay he follows.

The way it works is that the retaining pin alternates 7 pushed in, the thumb 8 withdrawn and in the next phase the thumb pressed down and then the pin 7 is withdrawn, releasing the lowest piece 3 to continue falling, while the whole pile is held by the thumb up to the second from the bottom.

In the continuation of the guide tube are the two heating inductors 20 and 21, the Inductors 6 and 7 of the main patent correspond. The retaining pins 22 and 23 will be under the inductors also displaced by air pistons, the control of which is also carried out by the control valves 17 and off takes place. Here, too, the pins are retracted with a time delay under spring force. By the time lag The piston returns ensure that the workpieces are passed through individually.

The \ 'orteil of the device is that the height of the workpieces can be very different. It is only necessary to move the thumb 8 up or down. Furthermore, the pneumatic drive of the holding members for manufacturing facilities is very well suited due to its simple structure.

Claims (3)

Patent claims: 1. Al-storage device for a facility for inductive high-frequency heating of workpieces on non-ferrous metal for the purpose of hot pressing », the workpieces under the action of the high frequency in a time of less than 20 seconds be brought under in two stages to the temperature of the best deformability Passage of two high-frequency coils, characterized in that in a vertical guide tube ("It has two lateral breakthroughs one on top of the other for holding elements (7/8) are provided for the workpieces above, which alternate Can be pushed in and out, the lower holding member (7) being designed as a pin where the workpieces falling into the guide tube pile up, and the upper hook element (8) is a height-adjustable pressure thumb, which is attached to the second lowest workpiece in this way laterally is resiliently pressed. that this and the workpieces above it fall through further are obstructed, and wherein a drive means for the alternate engagement and disengagement of the IT organs are provided. 2. Apparatus according to claim 1, characterized in that controlled by λ entile for driving Compressed air cylinders with unilaterally acting pressure pistons are provided on the opposite side Return springs are arranged. 3. On loader according to claim 1, characterized in that in pairs with the pressure cylinders two further pressure cylinders are coupled for the flow control of the A workpieces through the subsequent heating inductors. Considered publications:
Rough. Practical Transmission theory, 1939. Vol. 2. P. 192. Fig. 483. 484, 485, 487. 1 sheet of drawings © 009 530/469 6.