Electromagnetic drive mechanism and a high-pressure fuel supply pump

An electromagnetic valve mechanism comprising:

• an inward-opening valve body provided at a fluid intake port,
• a movable plunger mounted to the valve body,
• an electromagnetic drive mechanism for biasing electromagnetically the movable plunger thereby opening the valve body, and
• a spring for biasing the valve body and the movable plunger along the direction of closing the fluid intake port, wherein
• the spring is the sole spring for biasing the valve body and the movable plunger along the direction of closing the fluid intake port, the valve body is operated in the direction of opening for resisting the force of the spring by the fluid differential pressure between upstream side pressure and downstream side pressure of the valve body to a specific distance, wherein the specific distance is a portion of an available range of plunger displacement, and the electromagnetic force is applied to the movable plunger after the movable plunger has been displaced the specific distance in the direction toward the direction of opening the valve body by the fluid differential pressure and displaces the movable plunger from the specific distance to a specific position which is greater than the specific distance.

An electromagnetic valve mechanism comprising:

• an inward-opening valve body provided at a fluid intake port,
• a movable plunger mounted to the valve body,
• a spring for biasing the valve body and the movable plunger in the direction along the direction of closing the fluid intake port, and
• an electromagnetic drive mechanism biasing electromagnetically the movable plunger and opening the valve body, wherein
• the spring is the sole spring for biasing the valve body and the movable plunger in the direction alone the direction of closing fluid intake portion, and after the valve body has initially opened a specific distance as the result of resisting the force of the spring caused by the fluid differential pressure between upstream side pressure and downstream side pressure of the valve body, the electromagnetic drive mechanism applies an electromagnetic force to the movable plunger for biasing the movable plunger in the direction along which the valve body is kept open or kept further open and displaces the movable plunger from the specific distance to a specific position which is greater than the specific distance.

A high-pressure fuel supply pump including an intake channel through which fuel is taken into a pressure chamber, a discharge channel through which the fuel is delivered from the pressure chamber, and a plunger which reciprocates in the pressure chamber draws and discharges the fuel, and the intake channel has an electromagnetic intake valve and the discharge channel has a discharge valve, and the amount of fuel delivered is controlled by connecting and disconnecting the intake channel to the pressure chamber by opening and closing the electromagnetic intake valve;

• wherein
• the electromagnetic intake valve is an electromagnetic drive mechanism comprising
• an intake valve operated by a magnetic biasing force,
• the electromagnetic drive mechanism opens the intake valve and keeps it open by means of the magnetic biasing force,
• a restricting member for restricting, in a specific position, the displacement of the intake valve when it opens, and
• a biasing member for biasing the intake valve in the direction of closing the valve, wherein
• the biasing member is the sole biasing member for biasing the intake valve in the direction of closing the valve, and when the electromagnetic drive mechanism is turned off, after the intake valve is displaced in the direction of opening the valve for resisting the force of the biasing member a specific distance which is a portion of the specific position due to a fluid differential pressure between the intake channel side pressure and pressure chamber side pressure of the intake valve, the electromagnetic drive mechanism is turned on and biases the movable plunger toward the direction of opening the intake valve body and displaces the movable plunger from the specific distance to a specific position which is greater than the specific distance.

A high-pressure fuel supply pump including an intake channel through which fuel is taken into a pressure chamber, a discharge channel through which the fuel is delivered from the pressure chamber, and a plunger which reciprocates in the pressure chamber draws and discharges the fuel, and the intake channel has an electromagnetic intake valve and the discharge channel has a discharge valve, and the amount of fuel delivered is controlled by connecting and disconnecting the intake channel to the pressure chamber by opening and closing the electromagnetic intake valve, wherein

• the electromagnetic intake valve is an electromagnetic drive mechanism comprising
• an intake valve operated by a magnetic biasing force,
• the electromagnetic drive mechanism opens the intake valve and keeps it open by means of the magnetic biasing force,
• a restricting member for restricting, in a specific position, the displacement of the intake valve when it opens, and
• a biasing member for biasing the intake valve in the direction of closing the valve, wherein
• when the electromagnetic drive mechanism is turned off, after the intake valve is displaced in the direction of opening the valve for resisting the force of the biasing member due to a fluid differential pressure between the intake channel side pressure and pressure chamber side pressure of the intake valve, the electromagnetic drive mechanism is turned on and biases the movable plunger toward the direction of opening the intake valve body, and
• during the period from when an input voltage is applied to the electromagnetic drive mechanism to when it is turned off, the input voltage is periodically applied and turned off in a shorter cycle.