Abstract: A solenoid apparatus includes a fixed core, a coil, and a movable core. The coil generates magnetic attractive force when the coil is supplied with electricity. The movable core is attracted to the fixed core by the magnetic attractive force generated between the fixed core and the movable core when the coil is supplied with electricity. The fixed core has a fixed axial end on a side of the movable core. The movable core has a movable axial end on a side of the fixed core. At least one of the fixed axial end and the movable axial end has at least one recession. The at least one of the fixed axial end and the movable axial end, which has the at least one recession, has an outer circumferential periphery and an inner circumferential periphery. The outer circumferential periphery radially communicates with the inner circumferential periphery through the at least one recession.

Abstract: A fluid injection valve has a valve body, a fixed core, a moving core, a coil and a valve element. The valve element slides together with the moving core to open and close a valve seat. The valve element has an annular connection portion at an axial end portion thereof to be connected and fitted to an inner circumferential face of the moving core. The valve element forms an inner space therein to open to the moving core. A side wall of the valve element has a notch thereon at a downstream side of the annular connection portion to form a communication passage between the inner space and an outer space outside of the valve element.

Abstract: A solenoid apparatus includes a fixed core, a coil, and a movable core. The coil generates magnetic attractive force when the coil is supplied with electricity. The movable core is attracted to the fixed core by the magnetic attractive force generated between the fixed core and the movable core when the coil is supplied with electricity. The fixed core has a fixed axial end on a side of the movable core. The movable core has a movable axial end on a side of the fixed core. At least one of the fixed axial end and the movable axial end has at least one recession. The at least one of the fixed axial end and the movable axial end, which has the at least one recession, has an outer circumferential periphery and an inner circumferential periphery. The outer circumferential periphery radially communicates with the inner circumferential periphery through the at least one recession.

Abstract: In a fuel injection device, a valve seat is formed on an inner peripheral surface of a valve body. The valve seat and a contacting portion of a needle form a sealing portion. Virtual perpendicular lines, which cross the sealing portion and are perpendicular to the inner peripheral surface of the valve body, intersect with each other at an intersecting point on a movable core side. The intersecting point is positioned between a first end of a guiding portion on a sealing portion side and a second end of the guiding portion opposite from the sealing portion. An end of the needle on a contacting portion side rotates around the intersecting point. Contact between the needle and the guiding portion is inhibited by positioning the intersecting point near the guiding portion.

Abstract: In a welding machine and welding method, for welding cylinder members together about an outside diameter, which prevents the cylinder members from being deformed and corrects the deformation of a portion to be welded, a laser beam, generated by a laser generator, is dispersed in two directions by a spectroscope. The laser beams focus on an outer cylinder member using two optical heads, respectively, in a plane perpendicular to a center axis of outer cylinder member. The optical heads are separated from each other by approximately 90 degrees in the plane. The outer and inner cylinder members are welded to each other in the circular direction using laser beams. Therefore, directions, in which the cylinder members are deformed due to the laser beams, are perpendicular to each other creating uniform radial deformation.

Abstract: In a welding machine and welding method, for welding cylinder members together about an outside diameter, which prevents the cylinder members from being deformed and corrects the deformation of a portion to be welded, a laser beam, generated by a laser generator, is dispersed in two directions by a spectroscope. The laser beams focus on an outer cylinder member using two optical heads, respectively, in a plane perpendicular to a center axis of outer cylinder member. The optical heads are separated from each other by approximately 90 degrees in the plane. The outer and inner cylinder members are welded to each other in the circular direction using laser beams. Therefore, directions, in which the cylinder members are deformed due to the laser beams, are perpendicular to each other creating uniform radial deformation.

Abstract: A stationary core has a press fitting portion and is secured to an inner peripheral wall of a tubular member by press fitting, so that an outer peripheral wall of the press fitting portion of the stationary core is engaged with the inner peripheral wall of the tubular member, and a radial space is formed upstream of the press fitting portion of the stationary core between the stationary core and the tubular member. The stationary core can have a tapered annular outer surface section, which is arranged in an outer peripheral wall of a downstream end portion of the stationary core and is tapered toward a downstream end of the stationary core at a taper angle of 2 to 60 degrees to have a reduced outer diameter.

Abstract: A fuel injection valve that sprays a finer particulate fuel has a tightly closed valve portion and can be assembled by press-fitting. A cup-shaped injection hole plate has its entire circumference joined to a valve body, has a bottom portion with injection holes, and has a cylindrical portion provided upright from the peripheral edge of the bottom portion. A resin sleeve has a resin annular portion with an opening that opens toward the downstream direction of fuel sprayed from the injection hole plate, and a resin cylindrical portion provided upright from the peripheral edge of the resin annular portion. The injection hole plate is provided with projections and the sleeve is provided with cutout grooves to engage the projections.

Abstract: In a fuel injection device, a valve seat is formed on an inner peripheral surface of a valve body. The valve seat and a contacting portion of a needle form a sealing portion. Virtual perpendicular lines, which cross the sealing portion and are perpendicular to the inner peripheral surface of the valve body, intersect with each other at an intersecting point on a movable core side. The intersecting point is positioned between a first end of a guiding portion on a sealing portion side and a second end of the guiding portion opposite from the sealing portion. An end of the needle on a contacting portion side rotates around the intersecting point. Contact between the needle and the guiding portion is inhibited by positioning the intersecting point near the guiding portion.

Abstract: In a fuel injection valve, a cylindrical valve body has a valve seat protruding radially inward out of an inner wall thereof and a needle supporting cylindrical inner wall. A nozzle needle is fixed to the armature so as to move together with the armature, while being supported slidably by the needle supporting cylindrical inner wall. The nozzle needle is provided with a valve portion to be seated on the valve seat when a coil is de-energized and inside thereof with a cavity into which fuel is introduced. A fuel accumulation bore is provided between inner circumference of the cylindrical valve body and outer circumference of the nozzle needle. With the construction mentioned above, the nozzle needle is provided with an opening through which the cavity communicates with the fuel accumulation bore.

Abstract: In a fuel injector, a valve unit consisting of a valve body and an injection plate is connected to a bottom end of a cylindrical housing. The valve unit is connected to the fuel injector after other components are assembled to the fuel injector. In the process of forming the valve unit, the valve body and the injection plate are coupled with each other, and then both are connected by welding. Then, the valve body having the injection plate welded thereto is inserted into a bottom end bore of the cylindrical housing, and then the valve body and the cylindrical housing are connected to each other by welding. A circular valve seat formed on the valve body is not deformed in the course of forming the valve unit and connecting the valve unit to the cylindrical housing.

Abstract: A stationary core has a press fitting portion and is secured to an inner peripheral wall of a tubular member by press fitting, so that an outer peripheral wall of the press fitting portion of the stationary core is engaged with the inner peripheral wall of the tubular member, and a radial space is formed upstream of the press fitting portion of the stationary core between the stationary core and the tubular member. The stationary core can have a tapered annular outer surface section, which is arranged in an outer peripheral wall of a downstream end portion of the stationary core and is tapered toward a downstream end of the stationary core at a taper angle of 2 to 60 degrees to have a reduced outer diameter.

Abstract: A fuel injection device includes a cylindrical valve housing, a valve needle disposed inside the valve housing and a ceramic heater disposed around the valve housing. The valve housing has a fuel inlet at an end, a first fuel passage, a second fuel passage, a nozzle hole at the other end and a valve seat. The valve needle has a hollow portion connected to the first fuel passage and a plurality of fuel apertures connecting the hollow portion and the second fuel passage, a head portion disposed to be seated on or unseated from the valve seat thereby intermittently injecting fuel through the nozzle hole. The ceramic heater is disposed around the valve housing down stream of the fuel apertures and upstream of the valve seat. Fuel vapor can be discharged upward though the fuel apertures.

Abstract: In a fuel injector, a valve member in a hollow cylindrical shape having a bottom is enclosed and supported in a magnetic cylinder defining a fuel passage to reciprocate in an axial direction. At least two of the ceramic heaters having an arc shape in cross section are arranged on the outer periphery of the magnetic cylinder in a circumferential direction to be a cylindrical shape. The ceramic heaters are pressed toward the outer periphery of the magnetic cylinder by a heater holder with a small resiliency. The ceramic heaters are tightly fitted on the outer peripheral surface of the magnetic cylinder without being damaged. Therefore, heat of the ceramic heaters is conducted to the magnetic cylinder and fuel in the magnetic cylinder is effectively heated.

Abstract: A nozzle needle has a hollow tubular form having a closed base end. A heat transfer tube is press fitted into a first magnetic portion. The heat transfer tube surrounds an outer peripheral surface of the nozzle needle. A ceramic heater is formed as an integral cylindrical body by sintering a ceramic material together with a heat generating resistive element. A case covers the heater and protects the heater from externally applied water. An inner tube of the case is resiliently engaged with both the heater and the first magnetic portion. Heat of the heater is conducted to the nozzle needle through the inner tube, the first magnetic portion and the heat transfer tube to heat fuel inside the nozzle needle.

Abstract: A fuel injection valve that sprays a finer particulate fuel has a tightly closed valve portion and can be assembled by press-fitting. A cup-shaped injection hole plate has its entire circumference joined to a valve body, has a bottom portion with injection holes, and has a cylindrical portion provided upright from the peripheral edge of the bottom portion. A resin sleeve has a resin annular portion with an opening that opens toward the downstream direction of fuel sprayed from the injection hole plate, and a resin cylindrical portion provided upright from the peripheral edge of the resin annular portion. The injection hole plate is provided with projections and the sleeve is provided with cutout grooves to engage the projections.

Abstract: A nozzle needle has a hollow tubular form having a closed base end. A heat transfer tube is press fitted into a first magnetic portion. The heat transfer tube surrounds an outer peripheral surface of the nozzle needle. A ceramic heater is formed as an integral cylindrical body by sintering a ceramic material together with a heat generating resistive element. A case covers the heater and protects the heater from externally applied water. An inner tube of the case is resiliently engaged with both the heater and the first magnetic portion. Heat of the heater is conducted to the nozzle needle through the inner tube, the first magnetic portion and the heat transfer tube to heat fuel inside the nozzle needle.

Abstract: In a fuel injector, a valve member in a hollow cylindrical shape having a bottom is enclosed and supported in a magnetic cylinder defining a fuel passage to reciprocate in an axial direction. At least two of the ceramic heaters having an arc shape in cross section are arranged on the outer periphery of the magnetic cylinder in a circumferential direction to be a cylindrical shape. The ceramic heaters are pressed toward the outer periphery of the magnetic cylinder by a heater holder with a small resiliency. The ceramic heaters are tightly fitted on the outer peripheral surface of the magnetic cylinder without being damaged. Therefore, heat of the ceramic heaters is conducted to the magnetic cylinder and fuel in the magnetic cylinder is effectively heated.

Abstract: In a fuel injector, a valve unit consisting of a valve body and an injection plate is connected to a bottom end of a cylindrical housing. The valve unit is connected to the fuel injector after other components are assembled to the fuel injector. In the process of forming the valve unit, the valve body and the injection plate are coupled with each other, and then both are connected by welding. Then, the valve body having the injection plate welded thereto is inserted into a bottom end bore of the cylindrical housing, and then the valve body and the cylindrical housing are connected to each other by welding. A circular valve seat formed on the valve body is not deformed in the course of forming the valve unit and connecting the valve unit to the cylindrical housing.

Abstract: In a welding machine and welding method, for welding cylinder members together about an outside diameter, which prevents the cylinder members from being deformed and corrects the deformation of a portion to be welded, a laser beam, generated by a laser generator, is dispersed in two directions by a spectroscope. The laser beams focus on an outer cylinder member using two optical heads, respectively, in a plane perpendicular to a center axis of outer cylinder member. The optical heads are separated from each other by approximately 90 degrees in the plane. The outer and inner cylinder members are welded to each other in the circular direction using laser beams. Therefore, directions, in which the cylinder members are deformed due to the laser beams, are perpendicular to each other creating uniform radial deformation.