CN110630422A

CN110630422A - Fuel injector assembly

Info

Publication number: CN110630422A
Application number: CN201910548677.1A
Authority: CN
Inventors: B.R.M.德赛; J.马尼坎丹; P.R.桑德普
Original assignee: Robert Bosch GmbH; Bosch Ltd
Current assignee: Robert Bosch GmbH; Bosch Ltd
Priority date: 2018-06-25
Filing date: 2019-06-24
Publication date: 2019-12-31
Anticipated expiration: 2039-06-24
Also published as: CN110630422B

Abstract

A fuel injector (200) assembly is configured to be mounted on a cylinder head (202) of an engine and includes at least a nozzle retainer (204) adapted for mechanical engagement with a nozzle body. The nozzle body (206) is adapted to be located within a cylinder head (202) of the engine via a nut (208). A sleeve (210) is mechanically engaged with the nut (208) along a length of the sleeve and abuts a sealing washer (212) along a diameter of the sleeve. The sealing gasket (212) is located within the cylinder head (202). A spring element (214) is located between the sleeve (210) and the nut (208).

Description

Fuel injector assembly

Technical Field

The present disclosure relates to the field of fuel injector assemblies.

Background

Fig. 1 illustrates a fuel injector according to the prior art. The injector 100 is used to inject pressurized fuel into an internal combustion engine. The injector 100 may be mounted on or within a cylinder head 102 of an internal combustion engine. To prevent combustion gases from entering the injector, a sealing gasket 104 is used. A sealing gasket 104 also supports the injector 100 within the cylinder head 102. Injector 100 is assembled to cylinder head 102 with a clamp assembly (not shown) by providing sufficient torque to bolts tightened to the clamp assembly such that a force of 8 kN to 15 kN is achieved between the seal gasket and the cylinder head sealing surface. This force ensures that no combustion gases leak through the gap between injector 100 and cylinder head 102 during the combustion process in the engine cylinder.

The thickness of the sealing gasket 104 is determined based on the desired performance of the engine and the emission target. Sealing gaskets of different thicknesses were used during development testing to compare performance and drainage results and to fix the thickness of the sealing gaskets based on the results used during real-time conditions. Nozzle-tip protrusions 106 (NTP) are also subsequently secured once a seal gasket thickness is selected for a particular engine configuration and application.

Nozzle Tip Projection (NTP) 106 defines the spray impingement plane and directly affects performance and discharge. Therefore, very little/no change in NTP 106 is preferable for better performance of the engine combustion characteristics, which directly affects emissions, performance, and drivability. However, due to manufacturing tolerances of the sealing gasket 104, cylinder head 102, and nozzle shaft length 105, the NTP 104 is different for all cylinders of the internal combustion engine, thereby affecting spray characteristics.

Drawings

Various modes of the invention are disclosed in detail in the specification and illustrated in the accompanying drawings:

FIG. 1 illustrates a fuel injector according to the prior art; and

FIG. 2 illustrates a fuel injector assembly according to an embodiment of the invention.

Detailed Description

FIG. 2 illustrates a fuel injector 200 according to an embodiment of the invention. The fuel injector 200 assembly is configured to be mounted on a cylinder head 202 of an engine and includes at least a nozzle holder 204 adapted for mechanical engagement with a nozzle body 206. The nozzle body 206 is adapted to be located within the cylinder head 202 of the engine via a nut 208. The sleeve 210 is mechanically engaged with the nut 208 along the length of the sleeve 210, which abuts the sealing washer 212 along the diameter of the sleeve 210. A sealing gasket is located within cylinder head 202. The spring element 214 is located between the sleeve 210 and the nut 208. In an embodiment, the sleeve 210 may be integral with the nut 208.

The structural features of the fuel injector 200 assembly will be disclosed in further detail. The fuel injector 200 assembly includes a nozzle holder 204. The function of the nozzle holder 204 is to receive high pressure fuel from the common rail. Nozzle holder 204 also includes a spindle 207 that may be actuated by a fuel pressure differential. The nozzle retainer 204 is adapted to mechanically engage the nozzle body 206. The nozzle body 206 is adapted to be located within the cylinder head 202 of the engine via a nut 208. Nozzle body 206 includes a nozzle valve 211, the movement of nozzle valve 211 causing spray orifices (not shown) in fuel injector 200 to open a path for fuel to flow from fuel injector 200 into the combustion chamber of an engine cylinder.

The sleeve 210 is mechanically engaged with the nut 208 by means of threads along the length of the sleeve 210. The sleeve 210 abuts the sealing gasket 212 along a diameter of the sleeve 210. A sealing gasket 212 is located within the cylinder head 202. The spring element 214 is located between the sleeve 210 and the nut 208, which nut 208 is integrated in the sleeve 210 to prevent backlash (backlash).

The operation of the fuel injector 200 assembly will be explained in further detail. The fuel injector 200 is used to inject pressurized fuel into an engine cylinder. To achieve this, the nozzle tip of the fuel injector 200 needs to protrude into the engine cylinder in order to spray the fuel in atomized form, as disclosed in fig. 2. The protrusions are referred to as Nozzle Tip Protrusions (NTP) and/or bumps 209. To avoid variations in the nozzle tip protrusion 209 due to variations in tolerances, the gap between the nut 208 and the sleeve 210 is adjusted by rotating the sleeve 210. The rotation angle of the sleeve 210 is according to the formula: angle = (k × 360)/p implementation. Where P = pitch of the sleeve (pitch), k = correction factor. The 'K' correction factor is the variation of the undesired NTP/the required NTP due to tolerances. Rotation of the sleeve 210 causes a change in the gap between the sleeve 210 and the nut 208, which in turn helps achieve the desired NTP. Thus, rotation of the sleeve 210 compensates for variations in the nozzle tip protrusion due to variations in tolerances. The function of the spring element 214 is to ensure that there is no backlash and to accurately adjust the nozzle tip protrusion.

It should be understood that the embodiments illustrated in the foregoing description are illustrative only, and are not limiting upon the scope of the invention, as to the type of injector used and the material used for the sealing gasket. Many other modifications and variations of such embodiments, as well as those illustrated in the specification, are contemplated. The scope of the invention is limited only by the scope of the claims.

Claims

1. A fuel injector (200) assembly, the fuel injector (200) assembly configured to be mounted on a cylinder head (202) of an engine and comprising at least:

a nozzle retainer (204) adapted for mechanical engagement with a nozzle body (206), the nozzle body (206) adapted to be located within a cylinder head (202) of the engine via a nut (208); it is characterized in that the preparation method is characterized in that,

a sleeve (210), the sleeve (210) mechanically engaged with the nut (208) along a length of the sleeve (210) and abutting a sealing gasket (212) along a diameter of the sleeve (210), the sealing gasket (212) located within the cylinder head (202); and a spring element (214), the spring element (214) being located between the sleeve (210) and the nut (208).

2. The fuel injector (200) of claim 1, wherein the sleeve (210) is integral with the nut (208).