Patent ID: 9709011
Date: 2017-07-18
CPC Classifications: F02M

Claim:
1. A fuel injection valve comprising: a body having a nozzle hole for injecting high-pressure fuel into a combustion chamber of an internal combustion engine; a nozzle needle movable back and forth in the body to open and close the nozzle hole; a control chamber configured to apply fuel pressure to the nozzle needle in a closing direction; a first intermediate chamber communicated with the control chamber through a control chamber communication passage and configured to receive high-pressure fuel through a high-pressure passage; a second intermediate chamber communicated with a low-pressure portion through an exhaust passage; a valve cylinder configured to partition the first intermediate chamber from the second intermediate chamber; a valve element movable in a cylinder hole, which is formed in the valve cylinder, to control communication between the control chamber communication passage and the high-pressure passage and to control communication between the exhaust passage and the second intermediate chamber; a valve element spring biasing the valve element in a direction to communicate the control chamber communication passage with the high-pressure passage and to block the exhaust passage from the second intermediate chamber; and an actuator configured to actuate the valve element in a direction to block the control chamber communication passage from the high-pressure passage and to communicate the exhaust passage with the second intermediate chamber, wherein the valve element includes: a high-pressure-side valve portion in an annular shape and configured to make contact with a high-pressure seat surface formed in the body and to move away from the high-pressure seat surface to control communication between the control chamber communication passage and the high-pressure passage; a low-pressure-side valve portion configured to make contact with a low-pressure seat surface formed in the body and to move away from the low-pressure seat surface to control communication between the exhaust passage and the second intermediate chamber; a releasing portion formed on a radially inside of the high-pressure-side valve portion and configured to communicate with the control chamber communication passage when the high-pressure seat surface is in contact with the high-pressure-side valve portion to block the control chamber communication passage from the high-pressure passage; and a valve element internal passage formed in the valve element and configured to communicate the releasing portion with the second intermediate chamber, wherein the releasing portion is blocked from the first intermediate chamber when the high-pressure seat surface is in contact with the high-pressure-side valve portion.