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US 6,578,775 B2Granted
Fuel injector
AssigneeDenso Corporation
InventorTakayuki Hokao
Life of this patent
Estimating the term…
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.
Claims19
A fuel injector comprising:
- a valve body having a cylindrical part defining a fuel passage and a valve seal at an end of the cylindrical part on a downstream fuel side and providing an orifice on a downstream fuel side of the valve seat;
- a valve member enclosed and supported in the valve body to reciprocate in the fuel passage in an axial direction of the cylindrical part, the valve member having a contact portion on a downstream fuel side end to be seated on the valve seat to close the orifice;
- a coil located on an outer periphery of the valve body, the coil generating a magnetic force for lifting the valve member from the valve seat when supplied with electricity;
- and
- a plurality of ceramic heaters provided on an outer peripheral surface of the cylindrical part axially between the valve seat and the coil, each of the plurality of ceramic heaters having an arc shape in cross section and being arranged in a circumferential direction to form a cylindrical shape in contact with an outer peripheral surface of the cylindrical part.
2 more elements
A fuel injector comprising:
- a valve body having a cylindrical part defining a fuel passage and a valve seal at an end of the cylindrical part on a downstream fuel side and providing an orifice on a downstream fuel side of the valve seat;
- a plurality of ceramic heaters provided on an outer peripheral surface of the cylindrical part on an upstream fuel side of the valve seat, each of the plurality of ceramic heaters having an arc shape in cross section and being arranged in a circumferential direction to form a cylindrical shape in contact with an outer peripheral surface of the cylindrical part;
- and
- a heater holder surrounding outer peripheral surfaces of the plurality of ceramic heaters and being in contact with the outer peripheral surface of the valve body;
- wherein the heater holder includes a large diameter part and a small diameter part, the plurality of ceramic heaters is inserted in the large diameter part and the small diameter part is press-fitted to the cylindrical part of the valve body.
2 more elements
A fuel injector comprising:
- a valve body having a cylindrical part defining a fuel passage and a valve seat at an end of the cylindrical part on a downstream fuel side and providing an orifice on a downstream fuel side of the valve seat;
- a valve member enclosed and supported in the valve body to reciprocate in the fuel passage in an axial direction of the cylindrical part, the valve member having a contact portion on a downstream fuel side end to be seated on the valve seat to close the orifice and lifted from the valve seat to open the orifice;
- a heating element provided on an outer peripheral surface of the cylindrical part of the valve body on an upstream fuel side of the valve seat;
- and
- a holder surrounding an outer periphery of the heating element and being in contact with both the outer periphery of the heating element and the outer peripheral surface of the cylindrical part of the valve body, wherein the holder is made of metal.
2 more elements
A fuel injector comprising:
- a valve body having a cylindrical part defining a fuel passage and a valve seal at an end of the cylindrical part on a downstream fuel side and providing an orifice on a downstream fuel side of the valve seat;
- a plurality of ceramic heaters provided on an outer peripheral surface of the cylindrical part on an upstream fuel side of the valve seat, each of the plurality of ceramic heaters having an arc shape in cross section and being arranged in a circumferential direction to form a cylindrical shape in contact with an outer peripheral surface of the cylindrical part;
- and
- a heater holder surrounding outer peripheral surfaces of the plurality of ceramic heaters and being in contact with the outer peripheral surface of the valve body, wherein the heater holder has a slit extending in an axial direction to provide resiliency.
1 more element
A fuel injector comprising:
- a valve body having a cylindrical part defining a fuel passage and a valve seat at an end of the cylindrical part on a downstream fuel side and providing an orifice on a downstream fuel side of the valve seat;
- a valve member enclosed and supported in the valve body to reciprocate in the fuel passage in an axial direction of a cylindrical part, the valve member having a contact portion on a downstream fuel side end to be seated on the valve seat to close the orifice and lifted from the valve seat to open orifice;
- a heating element provided on an outer peripheral surface of the cylindrical part of the valve body on an upstream fuel side of the valve seat;
- and
- a holder surrounding an outer periphery of the heating element and being in contact with both the outer periphery of the heating element and the outer peripheral surface of the cylindrical part of the valve body,
- wherein the holder has a large diameter part and a small diameter part, the heating element is press-fitted in the large diameter part and the small diameter part is press-fitted on the cylindrical part of the valve body.
3 more elements
A fuel injector comprising:
- a valve body having a cylindrical part defining a fuel passage and a valve seat at an end of the cylindrical part on a downstream fuel side and providing an orifice on a downstream fuel side of the valve seat;
- a valve member enclosed and supported in the valve body to reciprocate in the fuel passage in an axial direction of a cylindrical part, the valve member having a contact portion on a downstream fuel side end to be seated on the valve seat to close the orifice and lifted from the valve seat to open orifice;
- a heating element provided on an outer peripheral surface of the cylindrical part of the valve body on an upstream fuel side of the valve seat;
- and
- a holder surrounding an outer periphery of the heating element and being in contact with both the outer periphery of the heating element and the outer peripheral surface of the cylindrical part of the valve body,
- wherein the heating element is fitted around the outer peripheral surface of the cylindrical part of the valve body more loosely than the holder is fitted around the outer periphery of the heating element.
3 more elements
Dependencies are inferred from the claim text.