| 摘要 |
PURPOSE:To simplify the structure of a number of rotation detector by bringing a conductive movable sliding member and a contacting part, where a conductive part and a non-conductive part are combined, into contact with each other in accordance with rotation of a drive shaft of a fuel pump and detecting a voltage difference between them. CONSTITUTION:Slidable plungers 6a and 6b are provided in a cylinder chamber 3 in the front end of a drive shaft 2, and an insulating layer Z2 is provided on their sliding faces, and a conductive layer D1 is formed between them and the cylinder chamber 3. An insulating layer Z1 is provided between a housing 1 and an inner cam 9. This drive shaft 2 is rotated to supply fuel from a passage 11, and this fuel is sent from a retraction valve 19 to an injection nozzle through a feeder pump 4 and the cylinder chamber 3. At this time, the plunger 6a or the like sliding back and forth by rotation of the drive shaft 2 is made conductive or non-conductive to the cylinder chamber 3 in accordance with the rotation position, and a potential difference between the plunger 6a or the like and the housing 1 is changed. Consequently, the number of rotation is detected on a basis of the potential difference due to rotation positions of plungers 6a and 6b, and the structure of the number of rotation detector is simplified. |
