WO2013023995A1

WO2013023995A1 - An injection valve with efficient sealing

Info

Publication number: WO2013023995A1
Application number: PCT/EP2012/065612
Authority: WO
Inventors: Suat SACARCELIK; Barkin ARAK; Serkan ELMALI; Dogan Vardar; Rahman CAKIR; Nese YENIGUN; Erhan KAYAR; Veyzat GAZI; Ozan DINCEL; Ediz ILHAN; Tuna AYDIN
Original assignee: Robert Bosch Gmbh; COMERT, Alper
Priority date: 2011-08-13
Filing date: 2012-08-09
Publication date: 2013-02-21
Also published as: TR201108103A2

Abstract

The subject matter invention is an injection valve (10) for internal combustion engines, said injection valve (10) is characterized in that said valve piece (20) comprises a lower part (23) which extends in the region corresponding to the low pressure region (16); a middle part (22) which extends along the high pressure region (15) at the continuation of said lower part (23) and which has a wide part (222) with a diameter greater than the lower part (23); a seating edge (221) which is provided in the first sealing region (40) where the lower part (23) and said middle part (22) coincide and which corresponds to said first seating surface (40).

Description

SPECI FICATION

AN INJECTION VALVE WITH EFFICI ENT SEALING

TECHNICAL FI ELD

The present invention relates to injection valves used for spraying fuel to the combustion chamber in internal combustion engines and particularly relates to an injection valve regarding 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 the injection valve body and it is placed into the valve piece which separates the high pressure-low pressure regions from each other. The valve piece has opening and control volume which will transfer the fuel from the high pressure region to the piston in a controlled manner. Since the valve member, which is placed into the injection valve body, separates the different pressure regions from each other, a high resistance sealing member is needed. This sealing member leads to a longer life for the injection valve. In order to provide sealing between the high and low pressure regions, a sealing gasket is improved in the patent application WO 2008/125536 Al . The presence of a single sealing member is not sufficient for lengthening the life time of the injection valve. Therefore, another gasket is considered which will support the sealing member and as a result, the support gasket is improved. These members prevent the fuel, existing in the high pressure valve between the valve piece and the injection valve body, from leaking into the valve region. These sealing members are essentially disclosed in the patent application DE 100 20 870 Al. In order to provide leakage 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 seating gasket. The purpose of these two gaskets is to lengthen the lifetime of the injection valve. Since said gaskets have axial fixation problems, an improvement is realized in the patent application US 2007/0209610. In the improvement realized, the shapes of the sealing gasket and the support gasket are changed and an improvement is realized for fixing the axial positions thereof.

Moreover, in the patent application EP 1 710 429 Al, an improvement is realized where sealing is provided between the high and low pressure regions without a gasket. However, the improvements realized can not provide the required improvement for providing sealing during operation and during the production steps.

The support gasket and the sealing gasket existing in the region existing between the valve piece and the injection valve body can not realize the functions thereof after certain working hours as a result of the abrasion formed because of axial movement, high pressure and other mechanic effects. Therefore, in all of the injection valve systems where gaskets exist, a certain leakage within certain tolerances is permitted. However, as mentioned above, as the working hours increase, the leakage increases and the tolerance limits are exceeded. As the tolerance limits are exceeded, the system can not realize the spraying function. Moreover, since the gaskets are added to the injection valve during assembly, they lead to a cost increase. All of the pieces inside the injection valve which is movable as long as the engine is functioning are the pieces which are prone to failures. Therefore, production with minimum error and failure expectation has a positive affect on the injection valve and it also increases the lifetime 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 which is used for spraying fuel to the combustion chamber of the internal combustion engines and where sealing between the injection valve body and the valve piece is provided using formal embodiments, 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 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 the fuel enters to the injection valve; a needle region which realizes the spraying process of the fuel to the combustion chamber; a valve channel which carries fuel between said input region and said needle region; a high pressure region which is provided on said valve channel ; a low pressure region provided at the continuation of said high pressure region; sealing regions between said high and low pressure regions; a first seating surface in said first sealing region; and a valve piece. 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 alone the high pressure region at the continuation of said lower part and which has a wide part with a diameter greater than the lower part; a seating edge which is provided in the first sealing region where the lower part and said middle part coincide and which corresponds to said first seating surface.

In a preferred embodiment of the subject matter invention, in the first sealing region, there is at least one squashed washer which is provided between the first seating surface and the valve piece.

In another preferred embodiment of the subject matter invention, said wide part extends along the middle part.

In another preferred embodiment of the subject matter invention, said seating edge has sharp corners during the passage to the wide part.

In another preferred embodiment of the subject matter invention, the seating edge is embodied so as to contact with the body. 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.

BRIEF DESCRIPTION OF THE FIGU RES

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

In Figure 2, the detailed view of an injection valve is given.

REFER ENCE NUMBERS

10 Injection Valve

11 Body

12 Needle Region

13 Input Region

14 Squashed Washer

15 High Pressure Region

16 Low Pressure Region

17 Valve Channel

18 First Seating Surface

19 Second Seating Surface

20 Valve Piece

21 Upper Part

22 Middle Part

221 Seating Edge

222 Wide Part

23 Lower Part

24 Control Volume

25 Passage Opening

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 is used for spraying fuel to the combustion chamber in internal combustion engines and where sealing between the valve piece and the injection valve body is provided without additional sealing members and with figurative precautions.

With reference to Figure 1, an injection valve (10) comprises two regions defined on a cylindrical body (11). These regions are the needle region (12) and the input region (13). Said input region (13) is the region where the applied fuel enters into said injection valve (10) by means of different pieces of the vehicle. Inside said body (11), there is the filter system (not illustrated in the figure) which is in connection at the vicinity of the input region (13). Said needle region (12) is defined as the region where the fuel inside the injection valve (10) is sprayed to the combustion chamber in a controlled manner. In the needle region (12), there is the needle (not illustrated in the figure) and there are the auxiliary members (not illustrated in the figure) which are in connection with said needle. In order to transfer the fuel between the needle region (12) and the input region (13), there is valve channel (17) which is embodied on the body (11). Said valve channel (17) is positioned at the center of the body in a cross sectional manner. The valve channel (17) is embodied at the part which will be adjacent to the input region (13) by being widened. This region is defined as the high pressure region (15). Moreover the edge, which is embodied so as to be adjacent to the point where the valve channel (17) widens, is defined as the first seating surface (18).

The valve channel (17), whose diameter advances in a fixed manner in said high pressure region (15), widens in a sharp manner at the vicinity of the area where the fuel, coming from the filter, enters into the high pressure region (15). This edge, which is formed during widening, is defined as the second seating surface (19).

There is the valve piston (30) which is in connection with the valve channel (17). Said valve piston (30) is positioned inside the valve channel (17) so as to be between the needle region (12) and the input region (13). The valve piston (30) and the valve piece (20) are in connection. Said valve piece (20) is embodied in a cylindrical manner. The valve piece (20) is defined as a cylinder with three different widths. The valve piece (20) is positioned at the vicinity of the input region (13) of the valve piston (30) and at the end thereof existing in the high pressure region (15). The valve piece's (20) part which is closest to the needle region (12) is embodied so as to be the narrowest part of the cylinder and it is defined to be the lower part (23). The valve piece's (20) part which is adjacent to the high pressure region (15) is defined as the middle part (22,. The diameter widening of the valve piece (20), which is formed during the passage from said lower part (23) to said middle part (22), is provided by an edge. Said edge is defined as the seating edge (221). In this region, there is a squashed washer (14) the valve piece (20) and the valve channel (17). The region formed by the valve piece (20), the valve channel (17) and said squashed washer (14) is defined as the first sealing region (40).

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 (24). At the vicinity of said control volume (24), a passage opening (25) is embodied on the middle part (22) in order for the fuel filtered through the filter to reach the region. When viewed from the cross section, said passage opening (25) has a funnel-like view. The valve piece (20) is embodied so as to be adjacent to the control volume (24) and at the side of the input region (13) of the valve piston (30) by widening the diameter at the continuation of the middle part (22). This part is defined as the upper part (21). The valve piston (30) covers the high pressure region (15) from the upper 6 point at said upper part (21) and there is no space between the valve piston (30) and the valve channel (17). This region is defined as the second sealing region (50). The valve piece (20) and the valve piston (30) are

responsible for transferring the high pressured fuel to the needle region (12) in a controlled manner. The function of the valve piece (20) during this process is to separate the high pressure region (15), where the valve channel (17) and the valve piston (30) function, from the low pressure regions (16) inside the injection valve body (11 ). The function of the squashed washer (14), which exists on said first seating surface (18) between the valve piece (20) and the body (11), is to facilitate the seating of the valve piece (20) onto the first seating surface (18) and onto said second seating surface (19) in a tight manner during assembly. In a figurative manner, the valve piece (20) seats completely at the second seating surface (19) part embodied on the body (11) by means of the upper part (21). Moreover, at the first seating part (19) of the valve piece (20), there is the squashed washer (14) in the area where it seats by means of the seating edge (221). By means of the angle moment controlled assembly member, the valve piece (20) is assembled to the region. Meanwhile, the squashed washer (14) is squashed between the first seating surface (18) and the valve piece (20) and after this squashing process is finished, the angle moment controlled assembly member begins counting the real revolution. However, during the assembly process realized, there is an uncertainty of around 1 0 ~ in the length of the valve piece (20). The squashed washer (14) is in connection with the region, in order to provide said uncertainty, formed during the assembly, to be within the length tolerance values and in order to form a firm first sealing region (18)_ By means of this, the injection valve (10) dimension and assembly adjustments are realized in an easy manner. Meanwhile, the valve piece (20) and the valve channel (17) seat onto each other; and as a result of this, the first sealing region (40) is formed. In the first sealing region (40) , leakage problems may occur. However, as known, the leakage is allowed within certain tolerances in the presently used systems. As a result of the fact that the squashed washer is squashed at the vicinity of 100- 200 μ, the sealing ratio provided in the first sealing region is five times smaller than the sealing ratio in the present system. Moreover, during the seating of the valve piece (20) and of the valve channel (17) onto each other on the second seating surface, squashing may occur in the materials, the valve piece and the valve channel squash each other 3 11 and they engage into each other. Thanks to this, sealing surfaces are formed which have tolerance which is lower than the permitted tolerances in said first and said second sealing regions (40, 50).

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.

Claims

An injection valve (10) for internal combustion engines, comprising an input region (13) wherein the fuel enters to the injection valve (10); a needle region

(12) which realizes the spraying process of the fuel to the combustion chamber; a valve channel (17) which carries fuel between said input region

(13) and said needle region (12); a high pressure region (15) which is provided on said valve channel (17); a low pressure region (16) provided at the continuation of said high pressure region (15); sealing regions (40, 50) between said high and low pressure regions (15,16); a first seating surface (18) in said first sealing region (40); and a valve piece (20), said injection valve (10) is characterized in that said valve piece (20) comprises a lower part (23) which extends in the region corresponding to the low pressure region (16); a middle part (22) which extends along the high pressure region (15) at the continuation of said lower part (23) and which has a wide part (222) with a diameter greater than the lower part (23); a seating edge (221) which is provided in the first sealing region (40) where the lower part (23) and said middle part (22) coincide and which corresponds to said first seating surface (40).

An injection valve (10) according to Claim 1, characterized in that in the first sealing region (40), there is at least one squashed washer (14) which is provided between the first seating surface (18) and the valve piece (20).

An injection valve (10) according to Claim 1 or 2, characterized in that said wide part (222) extends along the middle part (22).

An injection valve (10) according to anyone of the preceding claims, characterized in that said seating edge (221) has sharp corners during the passage to the wide part (222)

An injection valve (10) according to anyone of the preceding claims, characterized in that the seating edge (221) is embodied so as to contact with the body (11).