Abstract: A fuel injection valve includes a needle valve that controls communication between a high pressure chamber and an injection hole, a follower valve provided inside a control chamber controlled by fuel pressure inside an intermediate chamber, and an open-close valve that controls communication between a first passage and a low pressure passage and communication between a second passage and the low pressure passage. The fuel injection valve is configured to control the gradient of the fuel injection rate from the injection hole with an improved configuration.

Abstract: A fuel injection control device has a valve opening control portion which opens a control valve by electrically charging a piezoelectric element, and a valve closing portion which closes the control valve. The valve opening control portion includes a first rising control portion, a pause control portion and a second control portion. The first rising control portion increases a charge amount of the piezoelectric element during a first rising period. The pause control portion pauses an increase in the charge amount of the piezoelectric element during a pause period after the first rising period. The second rising control portion increases the charging amount of the piezoelectric elements again during a second rising period after the pause period. The pause period includes a period of immediately before the control valve is opened.

Abstract: The fuel injection valve includes a valve body having an injection hole at an end of the valve body facing in a first direction, and a needle valve provided inside the valve body and movable in an axial direction which includes the first direction and a second direction opposite to the first direction. A first control valve and a second control valve control the internal pressure of a back pressure chamber provided inside the valve body, a first actuator controls the first control valve, and a second actuator controls the second control valve. The second control valve is longer than the first control valve in the axial direction. The second actuator is located away in the second direction from the first actuator. A part of the second actuator overlaps at least a part of the first actuator when viewed in a plan view along the axial direction.

Abstract: The fuel injection valve includes a valve body having an injection hole at an end of the valve body facing in a first direction, and a needle valve provided inside the valve body and movable in an axial direction which includes both the first direction and a second direction opposite to the first direction. The needle valve is driven in the axial direction by a change in internal pressure of a back pressure chamber in the valve body. The fuel injection valve includes a control valve that controls the internal pressure of the back pressure chamber, and an actuator that drives the control valve. The control valve is longer than the needle valve in the axial direction. An end of the control valve facing in the second direction and the actuator are arranged away in the second direction from a center of the valve body in the axial direction.

Abstract: A fuel injection device includes a valve mechanism and a drive unit. The valve mechanism includes a first control valve body driven by a drive unit to open and close an outflow opening portion, a hydraulically actuated valve body for opening and closing an inflow opening portion by a pressure difference, and a second control valve body driven by the drive unit through the first control valve body. When a first drive energy is input to the drive unit, the second control valve body maintains a seated state on the hydraulically actuated valve body. When the second drive energy is input to the drive unit, the second control valve body is unseated from the hydraulically actuated valve body. According to the seating and unseating of the second control valve body, a flow channel area of a communication passage for communicating an upper control chamber portion with a lower control chamber portion is switched to another.

Abstract: A fuel injection valve includes a needle valve that controls communication between a high pressure chamber and an injection hole, a follower valve provided inside a control chamber controlled by fuel pressure inside an intermediate chamber, and an open-close valve that controls communication between a first passage and a low pressure passage and communication between a second passage and the low pressure passage. The fuel injection valve is configured to control the gradient of the fuel injection rate from the injection hole with an improved configuration.

Abstract: A fuel injection device includes a valve mechanism and a drive unit. The valve mechanism includes a first control valve body driven by a drive unit to open and close an outflow opening portion, a hydraulically actuated valve body for opening and closing an inflow opening portion by a pressure difference, and a second control valve body driven by the drive unit through the first control valve body. When a first drive energy is input to the drive unit, the second control valve body maintains a seated state on the hydraulically actuated valve body. When the second drive energy is input to the drive unit, the second control valve body is unseated from the hydraulically actuated valve body. According to the seating and unseating of the second control valve body, a flow channel area of a communication passage for communicating an upper control chamber portion with a lower control chamber portion is switched to another.

Abstract: A fuel injection control device has a valve opening control portion which opens a control valve by electrically charging a piezoelectric element, and a valve closing portion which closes the control valve. The valve opening control portion includes a first rising control portion, a pause control portion and a second control portion. The first rising control portion increases a charge amount of the piezoelectric element during a first rising period. The pause control portion pauses an increase in the charge amount of the piezoelectric element during a pause period after the first rising period. The second rising control portion increases the charging amount of the piezoelectric elements again during a second rising period after the pause period. The pause period includes a period of immediately before the control valve is opened.

Abstract: An enclosure member includes a throughhole that penetrates a cover portion. The cover portion includes a blocking portion that receives an abutment by a wall portion to close an opening of an outflow passage with respect to spaces outside of the enclosure member. The blocking portion is provided so as to surround an opening of the throughhole, and the throughhole is in communication with the outflow passage even when the blocking portion is abutting the wall portion. Further, a spring is outside of a back pressure chamber to bias the enclosure member. The enclosure member itself blocks outside spaces from the back pressure chamber, so the expenditure of high pressure fuel may be controlled, and an injection hole may be opened and closed by a needle.

Abstract: An enclosure member includes a throughhole that penetrates a cover portion. The cover portion includes a blocking portion that receives an abutment by a wall portion to close an opening of an outflow passage with respect to spaces outside of the enclosure member. The blocking portion is provided so as to surround an opening of the throughhole, and the throughhole is in communication with the outflow passage even when the blocking portion is abutting the wall portion. Further, a spring is outside of a back pressure chamber to bias the enclosure member. The enclosure member itself blocks outside spaces from the back pressure chamber, so the expenditure of high pressure fuel may be controlled, and an injection hole may be opened and closed by a needle.

Abstract: A fuel injection valve includes a body including a first chamber that supplies fuel of a first pressure, a second chamber that supplies fuel of a second pressure, and an injection hole, a valve chamber member including a valve chamber connectable to the first chamber and the second chamber, a control chamber member including a control chamber connectable to the first chamber, a needle pressed by pressure of fuel in the control chamber in a direction that causes fuel injection from the injection hole to stop, an actuator, a valve element that selectively connects the first chamber, second chamber, and the valve chamber according to the actuator extending and contracting, and a transmission mechanism that when the actuator extends, transmits the force to the needle as a force in a direction that causes fuel to be injected from the injection hole.

Abstract: A high-pressure-side valve portion makes contact with and moves from a high-pressure seat surface formed in a body to control communication between a control chamber communication passage and a high-pressure passage. A low-pressure-side valve portion makes contact with and moves from a low-pressure seat surface formed in the body to control communication between an exhaust passage and a second intermediate chamber. A releasing portion in the high-pressure-side valve portion communicates 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. A valve element internal passage is formed in the valve element to communicate the releasing portion with the second intermediate chamber.

Abstract: A valve cylinder partitions a first intermediate chamber from a second intermediate chamber. A first valve element in the first intermediate chamber includes a tubular high-pressure-side valve portion to control communication between a control chamber communication passage and the first intermediate chamber. A second valve element in the second intermediate chamber includes a low-pressure-side valve portion to control communication between an exhaust passage and the second intermediate chamber. A columnar rod portion located between the first valve element and the second valve element is slidably held at a cylinder hole of the valve cylinder. An internal passage communicates the control chamber communication passage with the second intermediate chamber. The high-pressure-side valve portion has an outer diameter greater than an outer diameter of the rod portion.

Abstract: A fuel injection valve includes a body including a first chamber that supplies fuel of a first pressure, a second chamber that supplies fuel of a second pressure, and an injection hole, a valve chamber member including a valve chamber connectable to the first chamber and the second chamber, a control chamber member including a control chamber connectable to the first chamber, a needle pressed by pressure of fuel in the control chamber in a direction that causes fuel injection from the injection hole to stop, an actuator, a valve element that selectively connects the first chamber, second chamber, and the valve chamber according to the actuator extending and contracting, and a transmission mechanism that when the actuator extends, transmits the force to the needle as a force in a direction that causes fuel to be injected from the injection hole.

Abstract: A valve cylinder partitions a first intermediate chamber from a second intermediate chamber. A first valve element in the first intermediate chamber includes a tubular high-pressure-side valve portion to control communication between a control chamber communication passage and the first intermediate chamber. A second valve element in the second intermediate chamber includes a low-pressure-side valve portion to control communication between an exhaust passage and the second intermediate chamber. A columnar rod portion located between the first valve element and the second valve element is slidably held at a cylinder hole of the valve cylinder. An internal passage communicates the control chamber communication passage with the second intermediate chamber. The high-pressure-side valve portion has an outer diameter greater than an outer diameter of the rod portion.

Abstract: A high-pressure-side valve portion makes contact with and moves from a high-pressure seat surface formed in a body to control communication between a control chamber communication passage and a high-pressure passage. A low-pressure-side valve portion makes contact with and moves from a low-pressure seat surface formed in the body to control communication between an exhaust passage and a second intermediate chamber. A releasing portion in the high-pressure-side valve portion communicates 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. A valve element internal passage is formed in the valve element to communicate the releasing portion with the second intermediate chamber.

Abstract: A fuel injection system for use with an internal combustion engine supplies fuel to an injector (fuel injection valve) from a common rail (accumulator) through a high-pressure pipe to spray the fuel from a spray hole formed in the injector. A thin-walled portion is formed in a path member (e.g., an injector body, the high-pressure pipe, or a connector connecting the injector and the high-pressure pipe) and defined by a locally thin wall of the path member. A strain gauge (strain sensor) is affixed to the thin-walled portion to measure strain of the thin-walled portion arising from the pressure of fuel in a high-pressure fuel path.

Abstract: It is used with a fuel injection system for an internal combustion engine which supplies fuel to an injector (fuel injection valve) from a common rail (accumulator) through a high-pressure pipe to spray the fuel from a spray hole formed in the injector. A thin-walled portion 70bz is formed in a path member (e.g., an injector body 4z, the high-pressure pipe, or a connector 70z connecting the injector and the high-pressure pipe) and defined by a locally thin wall of the path member. A strain gauge 60z (strain sensor) is affixed to the thin-walled portion 70bz to measure strain of the thin-walled portion 70bz arising from the pressure of fuel in a high-pressure fuel path 70az.