Abstract: A gap forming member has: a plate portion that is placed on an opposite side of a needle, which is opposite from a valve seat; and an extending portion that is formed to extend from the plate portion toward the valve seat, while an opposite end part of the extending portion, which is opposite from the plate portion, is contactable with a movable core. A first wall surface of the gap forming member, which is a wall surface opposed to an outer wall of the flange, is slidable relative to the outer wall of the flange, and a second wall surface of the gap forming member, which is a wall surface opposed to an inner wall of a stationary core, forms a radial gap, which is a gap in a radial direction, between the second wall surface and the inner wall of the stationary core.

Abstract: An inner side wall surface of a gap forming member, which is opposed to a flange outer wall surface of a flange of a needle, is slidable relative to the flange outer wall surface. Also, an outer side wall surface of the gap forming member, which is opposed to a stationary core inner wall surface of a stationary core, is slidable relative to the stationary core inner wall surface. The flange outer wall surface and the outer side wall surface are curved to project in a radially outer direction of a housing in a cross section thereof taken along an imaginary plane, which includes an axis of the housing.

Abstract: A gap forming member has: a plate portion that is placed on an opposite side of a needle, which is opposite from a valve seat; and an extending portion that is formed to extend from the plate portion toward the valve seat, while an opposite end part of the extending portion, which is opposite from the plate portion, is contactable with a movable core. A first wall surface of the gap forming member, which is a wall surface opposed to an outer wall of the flange, is slidable relative to the outer wall of the flange, and a second wall surface of the gap forming member, which is a wall surface opposed to an inner wall of a stationary core, forms a radial gap, which is a gap in a radial direction, between the second wall surface and the inner wall of the stationary core.

Abstract: A gap forming member has: a plate portion that is placed on an opposite side of a needle, which is opposite from a valve seat; and an extending portion that is formed to extend from the plate portion toward the valve seat, while an opposite end part of the extending portion, which is opposite from the plate portion, is contactable with a movable core. A first wall surface of the gap forming member, which is a wall surface opposed to an outer wall of the flange, is slidable relative to the outer wall of the flange, and a second wall surface of the gap forming member, which is a wall surface opposed to an inner wall of a stationary core, forms a radial gap, which is a gap in a radial direction, between the second wall surface and the inner wall of the stationary core.

Abstract: A movable core is movable relative to a needle main body of a needle. A stationary core is placed on an opposite side of the movable core, which is opposite from a valve seat. A spring is operable to urge the needle and the movable core toward the valve seat. A spring seat is shaped into a ring form and is placed on a radially outer side of the needle main body at the valve seat side of the movable core. The spring is placed between the movable core and the spring seat and is operable to urge the movable core toward the stationary core. A guide is placed on the valve seat side of the movable core in an inside of a housing. An outer wall of the spring seat is slidable relative to an inner wall of the guide to guide reciprocation of the needle.

Abstract: An inner side wall surface of a gap forming member, which is opposed to a flange outer wall surface of a flange of a needle, is slidable relative to the flange outer wall surface. Also, an outer side wall surface of the gap forming member, which is opposed to a stationary core inner wall surface of a stationary core, is slidable relative to the stationary core inner wall surface. The flange outer wall surface and the outer side wall surface are curved to project in a radially outer direction of a housing in a cross section thereof taken along an imaginary plane, which includes an axis of the housing.

Abstract: A gap forming member has: a plate portion that is placed on an opposite side of a needle, which is opposite from a valve seat; and an extending portion that is formed to extend from the plate portion toward the valve seat, while an opposite end part of the extending portion, which is opposite from the plate portion, is contactable with a movable core. A first wall surface of the gap forming member, which is a wall surface opposed to an outer wall of the flange, is slidable relative to the outer wall of the flange, and a second wall surface of the gap forming member, which is a wall surface opposed to an inner wall of a stationary core, forms a radial gap, which is a gap in a radial direction, between the second wall surface and the inner wall of the stationary core.

Abstract: A movable core is movable relative to a needle main body of a needle. A stationary core is placed on an opposite side of the movable core, which is opposite from a valve seat. A spring is operable to urge the needle and the movable core toward the valve seat. A spring seat is shaped into a ring form and is placed on a radially outer side of the needle main body at the valve seat side of the movable core. The spring is placed between the movable core and the spring seat and is operable to urge the movable core toward the stationary core. A guide is placed on the valve seat side of the movable core in an inside of a housing. An inner wall of the guide is slidable relative to an outer wall of the spring seat to guide reciprocation of the needle.

Abstract: A hydraulic pump includes a housing, a seat portion, and a valve element. The housing has a compression chamber and a fluid passage. The seat portion is provided midway through the fluid passage. The valve element is located between the compression chamber and the fluid passage. The valve element is a closed-end cylindrical member having a bottom portion, a cylindrical portion, and an opening end arranged in this order. The cylindrical portion is located farther away from the seat portion than the bottom portion. The valve element is seated to the seat portion at the bottom portion. A stopper substantially closes the opening end when making contact with the opening end to regulate movement of the valve element.

Abstract: In an injector, a first shaft portion of a needle is slidably supported by a first sleeves which is loosely received in a first internal chamber, and a second shaft portion of the needle is slidably supported in a body. Thereby, the first and second shaft portions are supported by the different members, and a relatively large clearance is formed on a radially outer side of the first sleeve.

Abstract: A coil is provided radially outside a housing. Each of a stator and a moving core is formed from a magnetic material and substantially in a tubular shape. The stator and the moving core are located radially inside the housing and opposed to each other in an axial direction. The moving core is configured to move toward the stator when being drawn by magnetic attractive force caused between the moving core and the stator in response to energization of the coil. A valve element is movable together with the moving core in the axial direction and configured to open and close a nozzle hole for controlling fuel injection. The moving core and the valve element are separate components. The moving core has an inner periphery defining a through hole in which the valve element is slidable in the axial direction. The inner circumferential periphery has a surface-hardened layer.

Abstract: In an injector, a first shaft portion of a needle is slidably supported by a first sleeves which is loosely received in a first internal chamber, and a second shaft portion of the needle is slidably supported in a body. Thereby, the first and second shaft portions are supported by the different members, and a relatively large clearance is formed on a radially outer side of the first sleeve.

Abstract: A hydraulic pump includes a housing, a seat portion, and a valve element. The housing has a compression chamber and a fluid passage. The seat portion is provided midway through the fluid passage. The valve element is located between the compression chamber and the fluid passage. The valve element is a closed-end cylindrical member having a bottom portion, a cylindrical portion, and an opening end arranged in this order. The cylindrical portion is located farther away from the seat portion than the bottom portion. The valve element is seated to the seat portion at the bottom portion. A stopper substantially closes the opening end when making contact with the opening end to regulate movement of the valve element.

Abstract: An electromagnetic device includes a solenoid stator comprised of a plurality of magnetic plates stacked spirally and regulated to prevent displacement. The stator is constructed by spirally disposing around its central axis a plurality of magnetic plates each having a uniform thickness and being bent in a curved shape. A support body of the device is so assembled to the stator as to abut its bottom face and a through hole. The support body has a disk part having an outer diameter generally corresponding to that of the stator and a cylindrical part extending upwardly from the central part of the disk part. The top end part of the cylindrical part is fixedly joined to the stator by laser welding. A push rod coupled with an armature is disposed slidably in a hole of the support body. The bottom face of a cap housing abuts the peripheral part of the top face of the stator to press the peripheral part from the upperside.

Abstract: A target fuel injection timing of the fuel injection pump is calculated based on the operating conditions of a diesel engine (Steps 102; 302; 602), while an actual fuel injection timing is calculated based on crank angle signals (Steps 103; 303: 603). Then, a fuel injection timing error (Terr) is obtained based on a difference between the target fuel injection timing and the actual fuel injection timing (Steps 104; 304; 604). To adjust the actual fuel injection timing based on the error (Terr), a rotational position of a roller ring (10) is controlled through a timer piston (21) slidable and housed in a timer device (28) by a hydraulic pressure control valve (27) in response to a pulse actuating signal having a controllable duty ratio (DFIN).

Abstract: An injection timing control device for a fuel injection pump includes an oil-pressure control valve for controllably changing the fuel injection timing of the fuel injection pump. The oil-pressure control valve includes a valve cylinder having a valve seat. The valve seat has a first truncated-conical surface. The oil-pressure control valve further includes a valve needle slidably received in the valve cylinder and movable by a control unit. The valve needle has a second truncated-conical surface for engaging with the first truncated-conical surface to close the oil-pressure control valve and disengaging from the first truncated-conical surface to open the oil-pressure control valve. The first and second truncated-conical surfaces, when engaged, form a circular seal line on which the first and second truncated-conical surfaces abut each other. The circular seal line has a diameter which is substantially the same as a diameter of the valve needle.

Abstract: An injection timing control device for a fuel injection pump includes a timer cylinder and a timer piston slidably received in the timer cylinder to define a high-pressure chamber and a low-pressure chamber at opposite axial ends thereof. The high-pressure chamber communicates with a high pressure side, while the low-pressure chamber communicates with a low pressure side and is provided therein with a spring for biasing the timer piston toward the high-pressure chamber. A servo valve having a spool is further provided. Communication between the high-pressure and low-pressure chambers is allowed or prohibited depending on movement of the spool of the servo valve. When the communication is allowed, a fuel pressure in the high-pressure chamber is released into the low-pressure chamber so that the timer piston moves toward the high-pressure chamber due to a biasing force of the spring. This movement of the timer piston is transmitted to a roller ring to retard a fuel injection timing.

Abstract: A fuel injection apparatus which, when raising fuel of a low viscosity and a low lubricating ability such as gasoline or methanol to a high pressure by a fuel injection pump and injecting it into a combustion chamber of an internal combustion engine etc., prevents the lubricating oil for the fuel injection pump from being diluted by this fuel by pressurizing a separate working oil with a viscosity and lubricating ability higher than the fuel by the fuel injection pump and raising the pressure of the fuel by a diaphragm apparatus by the pressure of the high pressure working oil and thereby supplies the same to the fuel injector.

Abstract: A hydraulic valve drive device for intake/exhaust valves of an internal combustion engine using an oil pump similar to a distributor type injection pump. A plunger rotates and engages in reciprocating motion to pressurize hydraulic fluid taken into a pressure chamber and opens to discharge the same into a hydraulic cylinder of a specific intake/exhaust valve in register with the passage. The intake/exhaust valve maintains its valve lift to continue remaining open when the supply of the hydraulic fluid is stopped, but closes when the plunger rotates so that the passage is communicated with a relief channel and the relief valve opens.