초록 ▼

The invention relates to an injection valve ( 1) comprising a booster piston (23), said piston delimiting a pump chamber ( 22) and a booster chamber (29). A valve ( 14) is provided in the inlet to the chamber (22). The valve is configured as a 3/2-way valve and controls the pressure in the pump cham

The invention relates to an injection valve ( 1) comprising a booster piston (23), said piston delimiting a pump chamber ( 22) and a booster chamber (29). A valve ( 14) is provided in the inlet to the chamber (22). The valve is configured as a 3/2-way valve and controls the pressure in the pump chamber (22). The pressure in the pump chamber (22) is converted into a correspondingly increased pressure in the booster chamber (29) and in an injection chamber (34) containing an injection needle (6), by means of the booster piston (23). The use of the valve (14) allows a precise control of the injection times.

대표청구항 ▼

What is claimed is: 1. An injection valve, comprising: a housing defining an input line; a controllable first valve arranged in said housing and connected to the input line defined in said housing; a pump piston having a first face and a second face arranged in said housing, wherein said housing an

What is claimed is: 1. An injection valve, comprising: a housing defining an input line; a controllable first valve arranged in said housing and connected to the input line defined in said housing; a pump piston having a first face and a second face arranged in said housing, wherein said housing and said second face of said pump piston delimit a pump chamber, the input line feeding the pump chamber through said first valve, said housing and said first face of said pump piston defining a booster chamber, wherein said first valve comprises a 3/2-way valve having a first line connection connected to the input line, a second line connection connected to a first feeder line defined in said housing and connected to the pump chamber, and a third line connection connected to a discharge line defined in said housing, the first feeder line being connected to the input line in a first operating state of said first valve and the first feeder line being connected to the discharge line in a second operating state of said first valve; a second valve selectively connecting said booster chamber and a fuel reservoir defined by said housing, said housing further defining an injection chamber connected to said booster chamber, wherein said pump piston transmits a pressure in the pump chamber to produce a higher pressure in the booster chamber and the injection chamber; and a movable injection needle projecting into the injection chamber, said injection needle having a pressure surface in the injection chamber, said injection needle being movable for selectively opening or closing spray holes defined in said housing, wherein a position of said injection needle is set in response to the pressure in the pump chamber which is controlled by said first valve. 2. The injection valve of claim 1, wherein said first valve includes a first valve chamber connected to the input line, a sealing seat formed in the first valve chamber around an outflow opening connected to the first feeder line, said first valve further comprising a first closing element movable into sealing engagement with said sealing seat, said first closing element being moveable to selectively connect the first valve chamber to the first feeder line. 3. The injection valve of claim 2, wherein said first closing element has a first conical sealing surface and said sealing seat has a second conical sealing surface. 4. The injection valve of claim 3, wherein said first valve further includes a second valve chamber connected to the discharge line and a connecting borehole connecting said first valve chamber and said second valve chamber, said first valve further comprising a second closing element in the second valve chamber and a rod connecting said first closing element to said second closing element, said rod passing through said connecting borehole. 5. The injection valve of claim 4, further comprising an actuator linked with said second closing element, wherein said first and second closing elements are positioned in response to said actuator. 6. The injection valve of claim 5, wherein said injection valve comprises a central axis of symmetry and said first and second valve chambers are arranged along a line parallel to said central axis of symmetry. 7. The injection valve of claim 6, wherein said first and second valve chambers are arranged along said central axis of symmetry. 8. The injection valve of claim 4, wherein the second valve chamber has a sealing seat with a third sealing surface surrounding an inlet opening connected to the connecting borehole, and said second closing element includes a fourth sealing surface associated with said third sealing surface. 9. The injection valve of claim 8, wherein said third and fourth sealing surfaces are conical surfaces. 10. The injection valve of claim 8, wherein said third and fourth sealing surfaces comprise planar surfaces and said connecting borehole is connected to the first feeder line. 11. The injection valve of claim 8, wherein said third and fourth sealing surfaces are sealingly engaged in said first operating state and said first and second sealing surfaces are sealingly engaged in said second operating state. 12. The injection valve of claim 4, further comprising a landing plate arranged between said first valve and said pump piston, wherein said first face of said pump piston comprises a raised landing surface, said pump piston being movable to a position in which said raised landing surface abuts said landing plate, said feeder line opening into said pump chamber in an area outside the landing surface. 13. The injection valve of claim 1, further comprising a piezoelectric actuator connected for actuating said first valve. 14. The injection valve of claim 13, wherein said housing comprises an upper end proximate said first valve and a lower end proximate said spray holes, said actuator being at least partially inserted into said upper end of said housing. 15. The injection valve of claim 14, wherein said injection valve comprises a central axis of symmetry and said piezoelectric actuator comprises a central axis located on the central axis of symmetry of said injection valve. 16. The injection valve of claim 4, further comprising a piezoelectric actuator connected for actuating said first valve. 17. The injection valve of claim 16, wherein said housing comprises an upper end proximate said first valve and a lower end proximate said spray holes, said actuator being at least partially inserted into said upper end of said housing. 18. The injection valve of claim 17, wherein said injection valve comprises a central axis of symmetry and said piezoelectric actuator comprises a central axis located on the central axis of symmetry of said injection valve. 19. An injection valve, comprising: a housing defining an input line; a controllable first valve arranged in said housing and connected to the input line defined in said housing; a pump piston having a first face and a second face arranged in said housing, wherein said housing and said second face of said pump piston delimit a pump chamber, the input line feeding the pump chamber through said first valve, said housing and said first face of said pump piston defining a booster chamber; a second valve selectively connecting said booster chamber and a fuel reservoir defined by said housing, said housing further defining an injection chamber connected to said booster chamber, wherein said pump piston transmits a pressure in the pump chamber to produce a higher pressure in the booster chamber and the injection chamber; a movable injection needle projecting into the injection chamber, said injection needle having a pressure surface in the injection chamber, said injection needle being movable for selectively opening or closing spray holes defined in said housing, wherein a position of said injection needle is set in response to the pressure in the pump chamber which is controlled by said first valve; and a landing plate arranged between said first valve and said pump piston, wherein said first face of said pump piston comprises a raised landing surface, said pump piston being movable to a position in which said raised landing surface abuts said landing plate, said first valve comprising a feeder line opening into said pump chamber in an area outside the landing surface.