A high pressure fuel pump for delivering fuel, which is suctioned into a pressurizing chamber from a low pressure fuel pump through a suction passage, to a supply destination after pressurizing the fuel in the pressurizing chamber with a plunger, the high pressure fuel pump comprising:
- a pump body that slidably supports the plunger and forms the suction passage, the pressurizing chamber, a release passage and a drain passage, wherein the pressurizing chamber is communicated with the suction passage and the release passage through a connection, and the release passage and the drain passage are connected in this order to form an open passage, which always communicates between the connection and an outside of the pump body, along an entire extent of the release passage and the drain passage while the drain passage opens to the outside of the pump body;
- a control valve that is configured to open and close the connection;
- and
- a controller that is configured to control an operation of the control valve, wherein:
- the controller is configured to place the control valve in an opening state where the control valve opens the connection to supply the fuel from the suction passage to the pressurizing chamber through the connection in a suction stroke, during which the plunger is driven toward a suction side for suctioning the fuel into the pressurizing chamber;
- the controller is configured to place the control valve in a closing state where the control valve closes the connection at a closing timing in a delivery stroke, during which the plunger is driven toward a delivery side for delivering the fuel out of the pressurizing chamber upon pressurization of the fuel after the suction stroke;
- the controller is configured to maintain the control valve in the opening state to relieve the fuel, which is pressurized by the plunger, from the pressurizing chamber to a fuel tank through the connection, the release passage and the drain passage during the delivery stroke until the closing timing reaches after a start of the delivery stroke;
- the pressurizing chamber is one of a primary pressurizing chamber and a secondary pressurizing chamber, which are formed at the pump body;
- the plunger is one of a primary plunger and a secondary plunger respectively provided to the primary pressurizing chamber and the secondary pressurizing chamber, while a period of the delivery stroke of the primary pressurizing chamber and a period of the delivery stroke of the secondary pressurizing chamber are deviated from each other;
- the pump body forms:
- a cam receiving chamber that receives a drive cam, which is configured to drive the primary plunger and the secondary plunger through a primary tappet and a secondary tappet respectively;
- and
- a primary internal pressure variable chamber and a secondary internal pressure variable chamber, wherein an internal pressure of the primary internal pressure variable chamber and an internal pressure of the secondary internal pressure variable chamber change in response to reciprocation of the primary tappet and reciprocation of the secondary tappet, respectively, when the primary tappet and the secondary tappet are driven by the drive cam;
- and
- the suction passage includes:
- an inlet passage portion that communicates between the low pressure fuel pump and the cam receiving chamber to supply the fuel discharged from the low pressure fuel pump to the cam receiving chamber;
- a common passage portion that extends from the cam receiving chamber to a predetermined location in the pump body;
- a primary branch passage portion that is branched from the common passage portion and supplies the fuel from the common passage portion to the primary pressurizing chamber, wherein the primary branch passage portion includes an upstream part, which communicates between the common passage portion and the primary internal pressure variable chamber, and a downstream part, which communicates between the primary internal pressure variable chamber and the primary pressurizing chamber;
- and
- a secondary branch passage portion that is branched from the common passage portion and supplies the fuel from the common passage portion to the secondary pressurizing chamber, wherein the secondary branch passage portion includes an upstream part, which communicates between the common passage portion and the secondary internal pressure variable chamber, and a downstream part, which communicates between the secondary internal pressure variable chamber and the secondary pressurizing chamber.