| 摘要 |
1,062,805. Electro erosion. MINIMATION Inc. June 8, 1965 [June 22, 1964], No. 24183/65. Headings B3A and B3V. Apparatus suitable for electro-machining small openings in a fuel injection nozzle 38 includes a fixture 28 for the nozzle and a number of electrode guides 30 surrounding the nozzle, a source of electrical pulsating energy 168 being connected between the nozzle and electrodes. A servomotor 20 is energized by a signal corresponding to the gap between the nozzle and electrodes in order to keep the spacing between them at a desired value. The nozzle is held in position by a head 34 and dielectric fluid is circulated by a pump 26 between the fixture 28 and nozzle. The servomotor operates a pinion 54 to move a head 18 vertically, the head including a cup-shaped cam 70, which when raised, causes the outer portions of the guides 30 to move towards the nozzle for feeding electrode wires 40 inwardly. The wires pass between guide-wheels (Fig. 2, not shown) and longitudinally of the guides to the tip of the nozzle. Ratchet wheels, operated by spring-loaded pawls attached to the cam 70, produce step-by-step feeding of the electrode wires between each machining operation. Alternatively the wires may be fed by means of a solenoid surrounding each guide 30, the solenoid being energized as the guide moves inwardly and de-energized as it returns. A number of nozzles can be machined simultaneously by using several interconnected cams 70. The guides, instead of being screwed into the fixture 28, can be mounted on separate blocks and be individually operated hydraulically. |
