A FU EL INJECTION VALVE WITH EFFICI ENT SEALING

The present invention relates to injection valves used for spraying fuel to the combustion chamber in internal combustion engines and particularly relates to injection valve regarding to the prior art part of claim 1.

PRIOR ART

Said injection valves essentially comprise a valve body and a valve piston which functions as a piston inside said body. The injection valves essentially transfer high pressured fuel to the combustion chamber, existing in the engine, in a controlled manner.

The valve piston is placed into a valve piece which is placed into the injection valve body and which separates the high-pressure regions and low-pressure regions from each other. The valve piece has the opening and control volume which will transfer the fuel through the high pressure valve to the piston in a controlled manner. Since the valve member, which is placed into the injection valve body, separates different pressure regions from each other, it requires a high resistance sealing member. This sealing member increases the lifetime of the injection valve. By means of the patent application WO 2008/125536 Al, a sealing gasket is improved in order to provide sealing between the valve piece and the valve piston region. The presence of a single sealing member is not sufficient for increasing the lifetime of the injection valve. Therefore, another gasket is considered which will support the sealing member and the support gasket is improved. These members prevent the fuel, which exists in the high pressure valve between the valve piece and injection valve body, from leaking to the valve region. These sealing members are essentially disclosed in the patent application DE 100 20 870 Al. In order to provide sealing of the injection valve body of the valve member to the other parts thereof, there is a sealing gasket in ring form and there is a support gasket for fixing the sealing gasket. The purpose of these two gaskets is to lengthen the lifetime of the injection valve. Since said gaskets have axial fixation problems, in the patent application US 2007/0209640 Al, an improvement is realized. In the improvement realized, changes are realized in the shapes of the sealing gasket and in the support gasket, and an improvement is realized for fixing the axial positions thereof.

The sealing gasket and the support gasket, existing in the region remaining between the valve piece and the injection valve body, can not realize the function thereof in an exact manner after certain working hours as a result of the abrasion formed because of axial movement, high pressure and other mechanical effects. Therefore, in all of the injection valve systems where the gaskets exist, leakage ratios are permitted within certain tolerances. However, as mentioned above, as the working hours increase, leakage increases and the tolerance values of leakage are exceeded. As a result of exceeding the tolerance limits, the system can not realize the spraying function. However, since the gaskets are fixed to the injection valve during assembly, they lead to an increase in cost. All of the pieces inside movable injection valve as long as the engine functions are pieces which are prone to failures. Therefore, realizing production with minimum error and failure expectation has a positive affect on the injection valve and this increases the working life of the injector. As a result, because of the abovementioned problems, an improvement is required in the related technical field.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to an injection valve where sealing is provided between the valve piece and the injection valve body by means of formal embodiments and which is used for spraying fuel to the combustion chamber in internal combustion engines, in order to eliminate the abovementioned problems and to bring new advantages to the related technical field.

The main object of the present invention is to provide a fuel injection valve where the sealing between the valve piece and the injection valve body is provided without a gasket.

In order to realize all of the abovementioned objects and the objects which are to be obtained from the detailed description below, the present invention relates to an injection valve for internal combustion engines, comprising an input region wherein fuel enters to the injection valve; a needle region where the fuel is sprayed into the combustion chamber; a valve channel for carrying the fuel between said input region and said needle region; a high pressure region provided on the valve channel; a low pressure region provided at the continuation of said high pressure region; a valve piece and a sealing region between said high and low pressure regions. Said injection valve is characterized in that said valve piece comprises a lower part which extends in the region corresponding to the low pressure region; a middle part which extends at the continuation of said lower part and along the high pressure region and which has a wider diameter than the lower part; and a chamfer part which is provided at the first sealing region where the lower part and the middle part join; and said body comprises another chamfer part which is provided thereon so as to correspond to said chamfer part.

In a preferred embodiment of the subject matter invention, there is a squashed washer so as to provide a second sealing region between the valve piece and the body, in the region where the upper part of the valve piece is seated to the seating surface defined on the body.

In another preferred embodiment of the subject matter invention, there is an angled surface which provides diameter widening from the lower part towards the middle part of the valve piece and which provides sealing in the region which corresponds to the first sealing region.

In another preferred embodiment of the subject matter Invention, on the body, there is an angled surface on the surface of the widening corresponding to the sealing region. Which is provided during the passage from the low pressure region to the high pressure region.

In order for the embodiment and the advantages of the subject matter Invention to be understood in the best manner with the additional elements, it has to be evaluated with the detailed description and with the figures explained below. BRI EF DESCRIPTION OF TH E FIGU RES

In Figure 1, the general view of an injection valve is given.

In Figure 2, the cross sectional zoomed view of the valve piece and of the valve piston region is given.

REFERENCE NUMBERS 10 Injection Valve

11 Body

12 Input Region

13 Needle Region

14 Squashed Washer

15 Seating Surface

16 High Pressure Region

17 low Pressure Region

18 Body Chamfer

19 Valve Channel

20 Valve Piece

21 Passage Opening

22 Control Volume

23 Upper Part

24 Middle Part

241 Valve Piece Chamfer

25 lower Part

30 Valve Piston

40 First Sealing Region

50 Second Sealing Region

THE DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject matter improvement is explained with references to examples without forming any restrictive effect in order to make the subject more understandable. Accordingly, in the detailed description and in the figures below, an injection valve (10) is disclosed which sprays fuel to the combustion chamber in internal combustion engines; and where the sealing between the valve piece and the injection valve body is provided without the need for an additional piece and using figurative precautions.

The injection valve (10) generally comprises two parts on a single body (11). These parts are defined as the needle region (13) and the input region (12). The input region (12) is defined as the region where the fuel, applied by different pieces of the vehicle, enters into the injection valve (10). Inside the body (11), there is the filter system (not illustrated in the figure) which is in connection at the vicinity of the input region (12) and there is a valve piece (20) which is connected at the vicinity of the filter system. The needle region (13) is defined as the region where the fuel inside the injection valve (10) is sprayed to the combustion chamber in a controlled manner. The needle (not illustrated in the figure) and the members helping the needle (not illustrated in the figure) are in connection with the needle region (13). There are two channels embodied on the body (11) for providing the conduction of fuel between the needle region (13) and the input region (12). The channels are positioned where one of them exists at the center of the body in a cross section manner and where the other one is positioned at the vicinity of the body edge. The channel at the body (11) center is defined as 35 the valve channel (19). The valve channel (19) is embodied by being widened at the part thereof which is adjacent to the input region (12) and this region is defined as the high pressure region (17). During this widening process, chamfer (18) is formed on the comers formed.

In the high pressure region (16) the valve channel (19) whose diameter advances in a fixed manner, widens in a sharp manner at the vicinity of the region where fuel, coming from the filter, enters into the high pressure region (16). The valve piston (30) is in connection into the valve channel (19). The valve piston (30) exists between the input region (12) and the needle region (13) in the valve channel (19). There is a valve piece (20) which provides the valve piston (30) to be connected to the input region (1 2) and which separates the other parts of the valve channel thereof (19) from the high pressure region (16) and which is in connection with the top point at the input region (12) side of the valve piston (30). The valve piece (20) is in connection at the vicinity of the high pressure region (16) on the valve channel (19). The valve piece (20) is embodied in a cylindrical manner and the piece is defined as a cylinder with three different widths. The part, which is closest to the needle region (13), is embodied as the narrowest part of the cylinder, and it is defined as the lower part (25). In order to facilitate the assembly of the valve piece (20) in said region, it does not contact with the valve channel (19) on the outer side and it does not contact with the valve piston (30) on the inner side thereof. The valve piece's (20) region where the high pressure region (16) begins in the outer side is defined as the middle region (24). Chamfer (241) is embodied to the corner which is formed during the diameter widening formed during passage from the lower part (25) to the middle part (24) of the valve piece (20). Moreover, the valve piece (20) widens at the vicinity of the high pressure region (16) from inside by means of the chamfer (not illustrated in the figure) and the space between the valve piece (20) and the valve piston (30) narrows.

There is a space at the top point between the valve piston (30) and the valve piece (20). This space is defined as the control volume (22). At the vicinity of the control volume (22), In order for the fuel filtered on the middle part (24) through the filter to reach the region, a passage opening (21) is embodied on the valve piece (20) and when this passage opening (21) is viewed from the cross section, it has a funnel like appearance. The valve piece (20) is embodied so as to be adjacent to the control volume (22) and by widening the diameter at the continuation of the middle part (24), on the input region (12) side of the valve piston (30). The valve piston (30) is so that it will completely cover the high pressure region (16) from the top point in this region and so that there is no space between it and the valve channel (19). The squashed washer (14) is in connection so as to correspond between the upper part (23) and the seating surface (15). This region is defined as the second sealing region (50).

The valve piston (30) and the valve piece (20), existing in connection inside the valve channel (19) inside the injection valve body (11), transfer high pressured fuel to the needle region (13). The function of the valve piece (20) during this process is to separate the high pressure region (16), where the valve channel (19) and the valve piston (30) operates, from the low pressure regions (17) existing inside the injection valve body (11). The function of the squashed washer (14) existing between the seating surface (15) of the valve piece (20) is to facilitate the seating of the valve piece (20) onto the seating surface (15) in a tight manner during assembly and to form the second sealing region (50). While passing from the low pressure region (17) to the high pressure region (16), during the passage from the lower part (25) to the middle part (24), the purpose of the chamfer (241), existing on the valve piece (20) embodied widely by means of the chamfer (241), is to seat the surfaces, which are embodied by breaking chamfer (18) between the said regions on the valve channel (19) embodied by widening between the low pressure region (17) and the high pressure region (16), so as to be mutual and completely on each other and to provide sealing.

The valve piston (30) is seated to the space existing in the valve piece (20) in figurative means the valve piece (20) is seated completely onto the seating surface (1 5) embodied on the body (11) by means of the upper part (23). The squashed washer (14) is in connection, existing between the part of the upper part (23) corresponding to the seating surface (15) part and the seating surface (15). The valve piece (20) is assembled to the region by means of the angle moment controlled assembly member. Meanwhile, the squashed washer (14) is squashed between the seating surface (15) and the valve piece (20) and after this squashing process is completed, the assembly member, which is angle moment controlled begins counting the real revolution thereof. However, during the assembly process realized, an uncertainty of 10 μ is formed along the valve piece (20). The squashed washer (14) is in connection with the region in order to form a firm second sealing region (50) and in order to provide said uncertainty, formed during assembly, to be within length tolerance values. The chamfer (241) exists on the outer surface of the valve piece (20) and the chamfer (18) existing on the valve channel (19) seat onto each other meanwhile and the first sealing region (40) is formed.

In the first sealing region (40), sealing problems may be faced in a formal manner. However, as known, in the presently used systems, there is leakage tolerance within certain limits. However, the space existing on the circular sealing region formed by the chamfers (18, 24) as a result of the seating of the chamfers (18, 24) one above the other is equal to one fourth of the space existing in the present system. Moreover, during the seating of the chamfer (241), existing on the valve piece (20), to the chamfer (18) existing on the valve channel (19. a squashing occurs in the chamfer (18) existing on the valve channel (19) and the chamfers (18, 24) engage to each other by squashing each other 2 μ. The leakage regions existing inside the sealing region (40) is one fourth of the leakage regions in the present system and these leakage regions are disappear substantially as a result of the squashing of the chamfers (18, 24). The protection scope of the present invention is set forth in the annexed claims and cannot be restricted to the illustrative disclosures given above, under the detailed description. It is because a person skilled in the relevant art can obviously produce similar embodiments under the light of the foregoing disclosures, without departing from the main principles of the present invention.