Fluid sprinkling – spraying – and diffusing – Fluid pressure responsive discharge modifier* or flow... – Fuel injector or burner
Reexamination Certificate
2000-04-07
2002-04-23
Yuen, Henry C. (Department: 3747)
Fluid sprinkling, spraying, and diffusing
Fluid pressure responsive discharge modifier* or flow...
Fuel injector or burner
C123S467000
Reexamination Certificate
active
06375098
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an injection valve for the fuel injection in an internal combustion engine, in particular in a diesel engine, comprising a holder body in which a first passage is formed, a nozzle body of an injection nozzle which is secured at the holder body and in which a second passage is formed which is connected to the first passage and which with the latter forms a fuel infeed line for the injection nozzle, a closure mechanism for the closing off of the injection nozzle, and a sealing means for the sealing off of the connection point between the first and the second passage. Furthermore, the invention relates to a sealing means for the sealing off of the connection point between the two passages.
BACKGROUND OF THE INVENTION
An injection nozzle of the initially named kind is used in internal combustion engines such as Otto engines or diesel engines in order to inject the fuel directly into the cylinder of the internal combustion engine or indirectly into an antechamber which is in connection with the cylinder. The injection valve should introduce an amount of fuel which is as precisely metered as possible at a predetermined time point into the cylinder or the antechamber respectively as a finely distributed mist. For this purpose the injection nozzle of the injection valve is closed off by a closure mechanism, for example a nozzle needle, which is mechanically prestressed and which opens the injection nozzle briefly for the fuel injection, with the emerging fuel being atomized by the injection nozzle. In order that a sufficient amount of fuel is injected and the fuel is atomized as finely as possible in spite of the short injection duration, the fuel is fed in to the injection valve with a pressure of 1400 bar and more in the known injection systems, such as for example the common rail injection system.
In order that the closure mechanism which is required for the closing off of the injection nozzle can be installed, the known injection valves are constructed of several parts. Thus the actual injection nozzle is secured together with the closure mechanism at a holder body. The fuel infeed takes place via a first passage which is formed in the holder body and which is connected to a second passage which is formed in the nozzle body of the injection nozzle. The second passage ends in a pressure chamber or in an outlet opening of the injection nozzle. In order to avoid a leakage of the fuel between the holder body and the nozzle body, the connection point between the two passages is sealed off by a sealing means, such as for example a sealing disc, or through correspondingly machined contact surfaces between the holder body and the nozzle body.
Since the fuel which is located in the fuel supply line is under very high pressure, as explained above, the sealing means at the connection point between the passages must be designed in such a manner that it can withstand very high stresses. For this reason in the known injection valves the sealing surfaces which are formed at the holder body and the nozzle body, at which the sealing means lies in contact, and the sealing means itself must be manufactured with very high manufacturing precision and high surface quality. Moreover, the sealing means which is arranged between the holder body and the nozzle body must be pressed together with such a high bias force that the connection point between the two passages does not leak in spite of the high pressures.
SUMMARY OF THE INVENTION
The object of the invention is to further develop an injection nozzle or, respectively, a sealing means of the initially named kind in such a manner that the connection point between the passages is sealed off in a simple manner and can also withstand high pressures.
This object is satisfied in the injection nozzle of the initially named kind in that a sleeve which protrudes at least into the first passage of the holder body or into the second passage of the nozzle body serves as a sealing means.
In the injection valve in accordance with the invention the sleeve, which protrudes into the passage, is pressed by the high pressure acting in the interior of the fuel infeed line against the inner wall of the passage and conforms to the surface of the latter, through which a leakage-free sealing off at the connection point between the passages is achieved. Moreover, lower demands need be placed on the manufacturing precision and the surface quality both during the manufacture of the passage and in the manufacture of the sleeve than in conventional injection valves since the sleeve, which conforms to the inner wall of the passage through the high pressure, compensates possible unevennesses or measurement deviations. Furthermore, the assembly of the injection valve is facilitated since the sleeve serves at the same time as a centering aid which simplifies the exact mutual orientation of the holder body and the nozzle body and the mutual alignment of the passages.
Advantageous further developments result from the description, from the drawings and from the respective subordinate claims.
Thus it is particularly advantageous when the sleeve has a section of smaller outer diameter. Through this design of the sleeve it is achieved that the sleeve is more strongly widened by the high pressure in the weakened section of smaller diameter than in the non-weakened sections of the sleeve and the sleeve conforms even better to the inner wall of the passage, with it bulging slightly outwardly in a convex manner at the same time. Through the convex deformation the transition between the section of smaller diameter and the adjacent, non-weakened section of the sleeve lays itself linear at the inner wall of the passage, through which a particularly good sealing action is achieved. In this the section of smaller diameter is preferably arranged in the region of the connection point between the passages in order to achieve as great a sealing action at the connection point as possible.
In a preferred embodiment of the injection valve the sleeve is formed as a separate component which is inserted into the fuel infeed line during the assembly of the injection valve and protrudes both into the first passage of the holder body and into the second passage of the nozzle body. This has the advantage that through the intentional selection of sleeves which differ in the design of the inner periphery the flow conditions of the fuel which flows through the fuel infeed line can be intentionally influenced.
In order that the sleeve has a secure hold in the fuel infeed line it can be pressed in into the passages so that a press fit is formed between the sleeve and the inner wall of the respective passage.
Alternatively, the sleeve can be formed integrally with the holder body or with the nozzle body. The sleeve then serves as a tubular prolongation of the first or of the second passage, respectively, which protrudes into the second passage of the nozzle body or the first passage of the holder body respectively after the assembly of the injection valve. In this embodiment of the injection nozzle there is the advantage that in the assembly of the injection valve there are only few components to be assembled.
Furthermore, it is advantageous when at least one of the passages has at its end which faces the other passage a section with a larger inner diameter in which the sleeve is accommodated or pressed in, respectively. If the sleeve is designed as a separate component, as in the first of the two exemplary embodiments described above, the sleeve can rest on the offset which is formed in the passage, whereby on the one hand a moving about of the sleeve in the fuel infeed line is effectively prevented and, on the other hand, the sleeve is held by the offset in a predetermined position in the fuel infeed line.
The fuel infeed line can be designed as a simple passage which extends through the holder body and the nozzle body. On the other hand the passages which form the fuel infeed line can also be used as a reception for the closure mechanism of the injection nozzle. Thus
Bosch Russell Harmon
Breitbach Hermann
Fujita Mahoro M.
Fuseya Tsutomu
Delphi Technologies Inc.
Gimie Mahmoud
Vanophem Attorney John
Yuen Henry C.
LandOfFree
Injection valve for the fuel injection in an internal... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Injection valve for the fuel injection in an internal..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Injection valve for the fuel injection in an internal... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2904330