Semi-Automatic Production Facility for Ornamental and Facing Rings
Task:
The manufacture of high-quality yet inexpensive ornamental and facing rings for the pot and fitting industry and for other applications presented us with the problem of finding another solution in addition to the fully automatic facility we already produce. The machine had to be on a much lower technical level to permit an initial start to ring production with approximately equivalent quality. It was accepted here that the quality of the rings would partly depend on the skill of the operator. The facility was to be operable by one or two persons.
(see also the fully automatic solution)
Solution:
1. Automatic steel strip feeding device
The steel strip feeding device can be of the double-sided or single-sided type in order to ensure problem-free production.
2. Cutting-to-length unit
It was assumed here that the skill of the operator should have no effect on the accuracy of the cutting operation. The length is preset exactly using an electronically powered intake unit, and the strip is cut to length without burr. The machine can be set to other sizes without difficulty simply by entering the appropriate numerical values. The entire control system has been accommodated in an 19″ module inside the base frame. This makes the facility very compact and suitable for even the most cramped conditions.
3. Welding unit
Two welding systems are possible: with the first variant more attention is devoted to the diameter of the welded ring, which is of major benefit when the ring is fitted. The second variant assumes that the overlap is adjustable and not dependent on the overall length of the strip. As a result the length tolerance of the cut strip has no effect on the weld overlap. The facility has a 40 kW transformer and a digital welding control unit. To change the ring size the clamping disc must be changed in the first variant. The welding tongs can be adjusted to the appropriate diameter in a guide slide. This permits a high degree of flexibility and adjustment to any ring size. For the unit to work self-sufficiently, it has its own cooling system accommodated in the base frame. Welding speed and electrode welding pressure can be precisely regulated. The entire unit has a stored-program control, installed like the power unit for the welding control in a 19″ module.
The welding control can also be provided with a pulse welding unit for precise welding work.
4. Profiling machine
When constructing the facility, a modular design was assumed. The drive of the rolling tool is DC-controlled, so permitting the speed to be precisely adjusted to the strip quality and to the appropriate ring diameter. To minimise the resetting times, a tool is available as an alternative which already integrates the ejection device and the entire lower section of the rolling tool. By undoing a screw it is possible to carry out the tool change.
Ring ejection is fully automatic and can be controlled so that the ring is deposited in a container. Both the rollers and the rolling tool are made of high-quality nitrided steel to withstand the heavy wear. To comply with safety regulations the facility has a two-hand control, and it can be operated in both setup mode and in fully automatic mode.
Tool set
The tool sets are not included in the general scope of supply, but are available separately. They comprise substantially the external and the internal ring and an efector device. Resetting the facility does not present problems because the roller plate and rolling tool can be changed over once a screw is loosened.
General technical sequence
With the first station (cutting-to-length unit), its is possible to work directly into a container or discharge chute. From there, the operator takes the part and welds the strip into a ring. After welding, an intermediate position can be activated, depending on the numbers required, so that the profiling machine can be operated by a second person. If the numbers required are below a certain level, all three facilities can be operated by the same person.
It must be remembered that when the strip width changes the guides of the cutting-to-length unit are changed also. During welding the clamping disc and the clamping jaws are replaced additionally.
