SPS – Welding spark plug casing
The machine for welding spark plug casing is designed for welding the external electrodes to the spark plug casing, subsequent adjustment of overflows after welding and shape cutting of the welded electrodes end. The machine can weld one, two, three or four electrodes to the casing. Each weld is measured – current thrust and size inspection.
Range of goods
Welding machine enables welding one, two, three, and four electrodes on the casing. The machine operates with 6HR 16 up to 21 mm casings with 20 to 42 mm height. Electrodes for welding: standard Ni alloys, Ni electrodes with inner Cu tube 7 to 12 mm.
100% inspection
All parameters of the production process which are decisive for the final product quality are measured, inspected , and evaluated in all welds.
1. Materials
The spark plug casing inlet in the machine is made from a vibration conveyor. The operational stock of casings has been created for the purpose of continuous machine operation. The conveyor system output is the accurately inserted casing in the eight position rotary table clamp.
The spark plug electrode is made from electrode wire coil. Operating station for the electrode manufacture consists of a sliding, a levelling mechanism and a cutting tool. The cutter creates optimum geometry for the electrode ends, which affects the weld strength. The machine also operates with single piece electrodes.
2. Locating the casing and electrode
The casing attached in the eight position table clamp is transported into the first station where the position and height of the casing location is inspected. Correctly located casing in the clamp is transported into the welding head area.
The casing and the electrode are in the welding head, positioned mutually as per the required geometrical parameters. The set is prepared for welding. The electrode is placed on the casing by means of a welding head movement in the X and Y axis supported by servo drives with an accuracy of 0.02 mm.
Welding cycle:
a) starting phase
b) welding phase
c) pause
d) annealing I.
e) cooling
f) annealing II.
The analysis of these values enables the computer to decide whether the weld is good or defective. The measuring results are statistically processed for evaluating the process and machine applicability. The welding head area is also designed for welding in a protective atmosphere.
3. Welding
Welding the casing with electrode is performed by means of incandescent welding. The welding cycle is control by a computer. All welding cycle phases can be parametrically adjust by users.
Welding power (thrust – power reaction between the casing and engine spark plug electrode) is initiated by the servo drive. The thrust size is adjustable. The welding current intensity in individual phases of the welding cycle and the thrust power value (strain gauge) is measured and evaluated..
4. External overflow of material
During the welding process, the material overflow occurs in the root area of the electrode weld, which can prevent the correct assembly of the final spark plug in the engine. In the following station, the external overflow of material is milled.
5. Internal overflow of material
In the following station, a part of overflow is removed above the internal opening. The removal is performed by means of cutting. The cutting device guiding part is adjusted to the required position and it cuts off the exceeding part of the electrode material overflow by means of immersion.
6. The elctrode end shape
If the shaping of the loose electrode end is required, the machine can perform it. The casing is placed in the cutting tool and the cutter forms the required geometry.
7. De-burring after the shaping cut
During the electrode shape cutting, burrs are created on the electrode starting cutting edge. The burrs are safely removed in this working station. The cutting of the shaping cut and the burrs are exhausted from the machine.
8. CCD inspection
The last station includes the measuring of completed weld geometry. The measuring is performed by means of CCD cameras. This visualisation method measures the welded electrode position in the radial and tangential direction against the casing.
It also measures the electrode height from the casing face and geometry, which is completed by means of a shaping cut on the loose electrode end. These measurements are evaluated by the control computer, and together with the welding process data create a base for decision making regarding the weld being good or faulty.
9. Selection
After completing the quality evaluation, the weld is released from the clamp jaw and transported to the transport box by means of sliding. During the sliding process, good and faulty pieces are selected. Faulty casings are separated as faulty from the welding procedure and from geometry inspection.
Technical data:
| Machine weight | 3200 kg |
| Machine dimensions | 2500 × 2200 × 4100 mm |
| Operational air pressure | 5 to 6 bar |
| Air consumption | cca 8000 l/hour (at 6 bar) |
| Operating voltage | 3NPE-50 Hz, 400 V/TN |
| Current intensity | 80 A |
| Machine performance | 1000 welds / hour. |
| Casing dimen | 6HR 16 mm to 21 mm |
| Casing height | 20 mm to 42 mm |
| Electrode height | 7 mm to 12 mm |
| Thrust force | 200 N to 400 N ± 0,5% JH |
| Thrust force measurement | strain gauge |
| Machine capacity | Cpk > 1,63 |
| CCD measuring tolerance | 0,02 mm |
| CCD measuring tolerance | Promat |
| Declaration of conformity | DLE 89/32/EWG |
| Number of operation stations | 8 |
| Re-adjustment of the machine | cca 2 hours |
| Non-compliance products | automatic selection |
| Evaluating the machine condition | remote – Internet |
| Number of electrodes on casing | 1; 2; 3; 4; |
| Welding process | PC controlled |
| Machine callibration | By user |
| Quality guarantee | 2 years |
