Fuel injection system and preheating device

Patent metadata

Field	Value
Publication number	US-9476389-B2
Application number	US-201214357568-A
Country	US
Kind code	B2
Filing date	Nov 9, 2012
Priority date	Nov 11, 2011
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A fuel injection system for an internal combustion engine may include at least one distributor unit to supply liquid fluid and a plurality of preheating systems each connected to the distributor unit. The respective preheating systems may have a preheating chamber and at least one heating element. A plurality of connection nozzles may each be connected to respective preheating systems. A fuel path may lead from the distributor unit through the respective preheating chambers to the respective injection nozzles of the plurality of preheating systems. The respective preheating systems may include a housing having an inlet and an outlet. The housing may be connected via a plug-in connection on the inlet to the distributor unit and via a plug-in connection on the outlet to the respective injection nozzle.

First claim

The invention claimed is:

1. A fuel injection system for an internal combustion engine, comprising:
at least one distributor unit to supply liquid fuel,
a plurality of preheating systems each connected to the distributor unit, the respective preheating systems having a preheating chamber and at least one heating element,
a plurality of injection nozzles each connected to respective preheating systems,
wherein a fuel path leads from the distributor unit through the respective preheating chambers to the respective injection nozzles, wherein the respective preheating systems comprises a housing having an inlet and an outlet, wherein the housing is connected via a plug-in connection on the inlet to the distributor unit and via a plug-in connection on the outlet to the respective injection nozzle;
wherein the at least one heating element of at least one preheating system is arranged coaxially in the preheating chamber, and wherein an inside of the at least one heating element delimits the preheating chamber radially relative to the fuel path and contains the fuel path radially inside of the at least one heating element.

2. The injection system according to claim 1 , wherein the respective heating elements at least partially enclose the respective preheating chamber.

3. The injection system according to claim 1 , wherein the respective housings are made of plastic.

4. The injection system according to claim 1 , wherein the heating element is a PTC element.

5. The injection system according to claim 1 , wherein the inside of the heating element is exposed to the fuel path.

6. The injection system according to claim 1 , wherein:
the housing inlet and outlet of the respective preheating systems include a radial inlet connected to the distributor unit and an axial outlet connected to the respective injection nozzle, respectively,
the respective preheating chambers and the respective heating elements are arranged in the respective housing coaxially to the outlet, and
wherein the respective heating elements include at least one radial inlet opening via which the inlet is connected fluidly to the respective preheating chamber.

7. The injection system according to claim 1 , wherein:
the housing inlet and outlet of the respective preheating systems include an axial inlet connected to the distributor unit and an axial outlet connected to the respective injection nozzle, respectively, and
the respective preheating chamber and the respective heating element are arranged coaxially to the inlet and the outlet in the respective housing.

8. The injection system according to claim 1 , wherein at least one heating element is arranged on an inside of the housing of at least one respective preheating system, the at least one heating element oriented towards the respective preheating chamber.

9. The injection system according to claim 1 , wherein at least one heating element is arranged on an outside of the housing of at least one respective preheating system, the at least one heating element oriented away from the respective preheating chamber.

10. The injection system according to claim 1 , wherein at least one heating element is integrated into a wall of the housing of at least one respective preheating system, the wall enclosing the respective preheating chamber.

11. The injection system according to claim 1 , wherein at least one housing includes a separating wall that encloses the respective preheating chamber and a radially spaced wall disposed away from the respective preheating chamber, wherein at least one associated heating element is arranged between the separating wall and the wall of the at least one housing.

12. The injection system according to claim 1 , wherein at least one housing includes a separating wall that encloses the respective preheating chamber, wherein at least one associated heating element is integrated into the separating wall such that the at least one heating element is arranged inside the separating wall.

13. The injection system according to claim 1 , wherein the number of injection nozzles equals a number of cylinders of the internal combustion engine.

14. The injection system according to claim 1 , comprising an operating nozzle and a cold start nozzle corresponding to each cylinder of the internal combustion engine, wherein the injection nozzle associated with the respective preheating system comprises the respective cold start nozzle.

15. The injection system according to claim 1 , wherein the respective preheating chambers include a preheating volume to accommodate a quantity of fuel sufficient for up to two injections of the liquid fuel from the respective injection nozzle at a cold start of the internal combustion engine.

16. The injection system according to claim 1 , wherein the respective heating element annularly encloses the respective preheating chamber.

17. The injection system according to claim 1 , wherein at least one of the plug-in connections on the inlet and outlet of the respective preheating systems are configured as a bayonet coupling.

18. A fuel injection system for an internal combustion engine, comprising:
at least one preheating assembly including a preheating chamber and at least one annular heating element at least partially enclosing the preheating chamber in a circumferential direction, the preheating assembly having a housing defining an inlet and an outlet;
a distributor unit coupled to the at least one preheating assembly via the inlet, the distributor unit configured to supply a liquid fuel to the at least one preheating assembly;
an injection nozzle coupled to the at least one preheating assembly via the outlet;
wherein the housing of the at least one preheating assembly couples to the distributor unit via an inlet plug-in connection and couples to the injection nozzle via an outlet plug-in connection, and a fuel path leads from the distributor unit through the preheating chamber to the injection nozzle;
wherein the inlet of the housing includes a radial inlet connected to the distributor unit configured to direct the liquid fuel radially to the preheating chamber and the outlet of the housing includes an axial outlet connected to the injection nozzle; and
wherein the preheating chamber and the at least one heating element are arranged in the housing coaxially to the outlet.

19. The fuel injection system according to claim 18 , wherein the radial inlet of the housing is arranged axially offset from an inlet opening of the at least one heating element so that the at least one heating element redirects the liquid fuel along the flow path.

20. A fuel injection system for an internal combustion engine, comprising:
a distributor unit to supply a liquid fuel;
a preheating system connected to the distributor unit, the preheating system having a preheating chamber and a heating element;
an injection nozzle connected to the preheating system, wherein a fuel path leads from the distributor unit through the preheating chamber of the preheating system to the injection nozzle;
wherein the preheating system includes a housing having an inlet and an outlet, wherein the housing is connected via a plug-in connection on the inlet to the distributor unit and via a plug-in connection on the outlet to the injection nozzle;
wherein the inlet of the housing includes a radial inlet connected to the distributor unit and the outlet of the housing includes an axial outlet connected to the injection nozzle;
wherein the preheating chamber and the heating element are arranged in the h

Assignees

• Mahle Int Gmbh

Inventors

• Amaral Tadeu
• Cruz Roberta
• Moreira Fabio
• Stehlig Juergen

Classifications

• F02M69/465

  of fuel rails · CPC title

• F02M2200/8015

  Provisions for assembly of fuel injection apparatus in a certain orientation, e.g. markings, notches or specially shaped sleeves other than a clip · CPC title

• F02M53/06

  with fuel-heating means, e.g. for vaporising · CPC title

• F02M53/02 Primary

  with fuel-heating means, e.g. for vaporising · CPC title

• F02M31/125

  Fuel · CPC title