Fuel injector

• US 5,915,626 A
• Filed: 07/23/1997
• Issued: 06/29/1999
• Est. Priority Date: 07/23/1996
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Maier, Stefan, Awarzamani, Assadollah
• Primary Examiner(s): Kaufman, Joseph A.
• Assistant Examiner(s): Nguyen, Dinh Q
• Application Number:
  US08/898,817
• Time in Patent Office: 706 Days
• Field of Search: 239/135, 239/585.1, 239/585.4, 239/585.5, 251/129.21, 137/341
• US Class Current: 239/135
• CPC Class Codes: F02M 31/125 Fuel
• CPC Class Codes: F02M 51/0614 characterised by arrangement of electromagnets or fixed armature
• CPC Class Codes: F02M 51/0682 the body being hollow and its interior communicating with the fuel flow F02M51/0675 takes precedence
• CPC Class Codes: F02M 53/06 with fuel-heating means, e.g. for vaporising
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y10T 137/6606 With electric heating element

Abstract

A fuel injector includes a magnetic coil whose power dissipation is utilized to pre-heat fuel flowing through the fuel injector. The magnetic coil is arranged so that a thermal coupling between the magnetic coil and the fuel flowing through a heat exchanger segment is acquired. In addition, a Peltier element (which functions as a heat pump) can be arranged between the magnetic coil and the heat exchanger segment. Furthermore, the fuel can also be heated using a heating coil.

Claims

1. A fuel injector for a fuel injection system of an internal combustion engine, comprising:

a valve seat element;

a value needle including a valve closing element, the valve closing element cooperating with the valve seat element to form a sealed seat;

a fuel inlet nozzle;

a fuel feed channel extending from the fuel inlet nozzle to the sealed seat and including a heat exchanger segment;

an armature connected to the valve needle; and

a magnetic coil segmentally surrounding the fuel feed channel and cooperating with the armature to actuate the fuel injector, the magnetic coil being thermally coupled to the heat exchanger segment,

wherein the magnetic coil is coupled to the heat exchanger segment one of directly and via a heat-conductive winding carrier holding the magnetic coil, and

wherein the heat-conductive winding carrier extends from the magnetic coil to the valve seat element.

4. The fuel injector according to claim 1, wherein the heat exchanger segment includes a heat conductor element composed of a high heat conductivity material.

2. A fuel injector for a fuel injection system of an internal combustion engine, comprising:

a valve seat element;

a valve needle including a valve closing element, the valve closing element cooperating with the valve seat element to form a sealed seat;

a fuel inlet nozzle;

a fuel feed channel extending from the fuel inlet nozzle to the sealed seat and including a heat exchanger segment;

an armature connected to the valve needle; and

a magnetic coil segmentally surrounding the fuel feed channel and cooperating with the armature to actuate the fuel injector, the magnetic coil being thermally coupled to the heat exchanger segment,

wherein the magnetic coil is coupled to the heat exchanger segment one of directly and via a heat-conductive winding carrier holding the magnetic coil,

wherein the winding carrier includes a thin-wall sleeve composed of a high heat conductivity material, the thin-wall sleeve surrounding the heat exchanger segment, and

wherein the magnetic coil is wound around the thin-wall sleeve.

3. The fuel injector according to claim 2, wherein the winding carrier includes a ring and a sleeve collar, the sleeve collar radially extending to the thin-wall sleeve and positioned at one end of the thin-wall sleeve, the sleeve collar and the ring limiting an extension of the magnetic coil along an axial direction of the fuel injector, the ring being settable on the thin-wall sleeve.

9. The fuel injector according to claim 2, wherein the thin-wall sleeve has a plurality of holes.

11. The fuel injector according to claim 2, wherein the high heat conductivity material includes a metal material.

5. A fuel injector for a fuel injection system of an internal combustion engine, comprising:

a valve seat element;

a valve needle including a valve closing element, the valve closing element cooperating with the valve seat element to form a sealed seat;

a fuel inlet nozzle;

a fuel feed channel extending from the fuel inlet nozzle to the sealed seat and including a heat exchanger segment;

an armature connected to the valve needle;

a magnetic coil segmentally surrounding the fuel feed channel and cooperating with the armature to actuate the fuel injector, the magnetic coil being thermally coupled to the heat exchanger segment; and

a Peltier element operating as a heat pump and being positioned between the magnetic coil and the heat exchanger segment, the Peltier element having a first surface facing the heat exchanger segment and a second surface facing the magnetic coil,

wherein the magnetic coil is coupled to the heat exchanger segment one of directly and via a heat-conductive winding carrier holding the magnetic coil, and

wherein, when the Peltier element is operating, a first temperature of the first surface increases and a second temperature of the second surface decreases.

6. The fuel injector according to claim 5, wherein the Peltier element includes a continuous hollow cylinder.

7. The fuel injector according to claim 5, wherein the Peltier element is divided into two half-shells forming a hollow cylinder.

8. The fuel injector according to claim 5, wherein the Peltier element is divided into a plurality of strips extending in an axial direction, the plurality of strips being circumferentially curved to form a hollow cylinder.

10. A fuel injector for a fuel injection system of an internal combustion engine, comprising:

a valve seat element;

a valve needle including a valve closing element, the valve closing element cooperating with the valve seat element to form a sealed seat;

a fuel inlet nozzle;

a fuel feed channel extending from the fuel inlet nozzle to the sealed seat and including a heat exchanger segment;

an armature connected to the valve needle;

a magnetic coil segmentally surrounding the fuel feed channel and cooperating with the armature to actuate the fuel injector, the magnetic coil being thermally coupled to the heat exchanger segment; and

a heating coil positioned between the magnetic coil and the sealed seat and extending along a fuel flow direction,

wherein the magnetic coil is coupled to the heat exchanger segment one of directly and via a heat-conductive winding carrier holding the magnetic coil.

12. The fuel injector according to claim 10, further comprising:

a plug-in connector providing power to the magnetic coil and to the heating coil.

13. The fuel injector according to claim 12, wherein the magnetic coil and the heating coil are simultaneously actuated and deactuated.

14. The fuel injector according to claim 10, wherein the heating coil heats fuel upstream from the sealed seat.