| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a new constitution must be added to reduce noise, which causes complication of a structure, affects a production process, and increases costs.SOLUTION: A fuel injection device 10 is provided with: a casing 20; a valve seat 30 that is provided on a lower end of the casing 20, and is provided at its upper portion with a cylindrical inner peripheral face 30A, and at its lower portion with a seating face 30B formed into the taper shape from the inner peripheral face 30A; and a needle-shaped needle valve 70 that is disposed inside of the casing 20, and slides from an upper part to a lower part in the casing 20 while in diagonal contact with an inner peripheral face of the casing 20 and the inner peripheral face 30A of the valve seat 30 due to an elastic force of a spring 80 to cause a tip ball portion 72 provided on the lower end to be seated on the seating face 30B, where the valve seat 30 is formed so that a clearance 2c of the inner peripheral face 30A has a larger value of 15 μm - 50 μm compared to a value of 11 μm that is as small as processing accuracy is kept.SELECTED DRAWING: Figure 6 |
