DE102020102194A1 - Fuel injector - Google Patents

Abstract

Fuel injection valve (10), with a nozzle body (11) which receives a nozzle needle (14), with at least one fuel supply line (15) being introduced into the nozzle body, which opens into a pressure chamber (16) which partially surrounds the nozzle needle (14) a nozzle holder (12), at least one fuel supply line (17) being introduced into the nozzle holder, which communicates with a respective fuel supply line (15) of the nozzle body, and with a clamping nut (13) via which the nozzle body and nozzle holder are axially braced. Coolant feed lines (22) and coolant discharge lines (23) communicating with one another are introduced into the nozzle body (11) and nozzle holder (12). On the end face (11a) of the nozzle body (11) and / or on the end face (12a) of the nozzle holder (12) adjoining the end face (11a) of the nozzle body (11) are an outer sealing surface (25) and at least one of the outer Sealing surface formed by at least one recess (24) separated inner sealing surface (26), the respective inner sealing surface (26) sealing the respective communicating fuel supply lines (15) in the area of the adjacent end faces, and the respective outer sealing surface (25) the respective communicating coolant lines (22, 23) in the area of the adjacent end faces.

Description

The invention relates to a fuel injection valve according to the preamble of claim 1.

From the DE 198 27 628 A1 a fuel injection valve for an internal combustion engine is known. So reveals the DE 198 27 628 A1 a fuel injection valve with a nozzle body, a nozzle holder and a clamping nut, the nozzle body and the nozzle holder being axially clamped via the clamping nut. The nozzle body receives a nozzle needle, with at least one fuel supply line being introduced into the nozzle body which opens into a pressure chamber for the fuel of the nozzle body surrounding the nozzle needle. In the nozzle holder, which is axially clamped to the nozzle body via the clamping nut, at least one fuel supply line is also attached, which communicates with the fuel supply line of the nozzle body, directly without an intermediate piece being arranged between the nozzle holder and the nozzle body. End faces of the nozzle body and the nozzle holder of the fuel injection valve that rest against one another are pressed against one another via the clamping nut as a result of the axial tensioning in order to provide a seal on the end faces that rest against one another.

After DE 198 27 628 A1 a recess is made in the end face of the nozzle body, as a result of which a radially outer sealing surface is formed on the end face of the nozzle body. This radially outer sealing surface seals the communicating fuel supply lines in the area of the end faces of the nozzle body and nozzle holder. A fuel leakage migrating over this sealing surface can get to the outside.

From the DE 199 14 720 B4 Another fuel injection valve for an internal combustion engine is known. This fuel injection valve has a union nut which holds several injector modules on top of one another, namely an injector head, a servo body, a transmission body, an intermediate body and a nozzle body. A recess is made on one end face of the injector head, forming an outer sealing surface and an inner sealing surface. The inner sealing surface seals fuel-carrying lines from the recess on the end face.

In the case of cooled fuel injection valves, the sealing of fuel lines and coolant lines has so far caused difficulties.

Proceeding from this, the present invention is based on the object of creating a novel fuel injection valve with reduced leakage of both fuel and coolant.

This object is achieved by a fuel injection valve according to claim 1. According to the invention, in the nozzle body and in the nozzle holder and in the optional intermediate piece communicating coolant supply lines and coolant discharge lines are introduced, via which coolant can be supplied to the nozzle body and removed from the nozzle body for cooling the nozzle body. An outer sealing surface and at least one inner sealing surface separated from the outer sealing surface by at least one recess are formed on the end face of the nozzle body and / or on the end face of the nozzle holder or the intermediate piece adjoining the end face of the nozzle body, the respective inner sealing surface being the respective communicating Seals fuel supply lines in the area of the adjoining end faces, and wherein the respective outer sealing surface seals the respective communicating coolant lines in the area of the adjoining end faces.

In the fuel injection valve according to the invention, separate, separate sealing surfaces are formed for sealing the fuel lines and for sealing the coolant lines. A respective inner sealing surface is separated from a respective outer sealing surface by at least one recess, the respective inner sealing surface sealing the fuel supply lines and the respective outer sealing surface sealing the coolant lines of the adjoining assemblies of the fuel injection valve in the area of the adjoining end faces. A fuel leak is caught in the area of the recess and cannot reach the outside via the respective outer sealing surface. A coolant leak can also migrate into the respective depression or to the outside. This allows a particularly advantageous sealing of a fuel injection valve while reducing fuel leakage and coolant leakage.

The respective depression preferably communicates with a leakage drain in the area of the nozzle holder, via which a leak that collects in the area of the depression can be discharged. In this way, a leak that collects in the area of the respective depression can be discharged from the fuel injection valve in a particularly advantageous manner.

According to a first variant, the respective outer sealing surface and the respective inner sealing surface are separated by a common recess for fuel leakage and coolant leakage. According to a second variant, the respective outer sealing surface and the respective inner sealing surface are separated by separate depressions for fuel leakage and coolant leakage. The first variant, which provides a common recess for fuel leakage and coolant leakage, is structurally simpler. The second variant with separate recesses for fuel leakage and coolant leakage is structurally more complex, but allows fuel leakage and coolant leakage to be discharged separately.

• 1 einen Axialschnitt durch ein Kraftstoffeinspritzventil;
• 2 das Detail II der 1; und
• 3 den Querschnitt III-III der 1.

Preferred developments of the invention emerge from the subclaims and the following description. Exemplary embodiments of the invention are explained in more detail with reference to the drawing, without being restricted thereto. It shows:

• 1 an axial section through a fuel injection valve;
• 2 the detail II of the 1 ; and
• 3 the cross-section III-III of the 1 .

The invention relates to a fuel injection valve. 1 shows an axial section through a fuel injection valve 10 for an internal combustion engine. The fuel injector 10 of the in 1 The embodiment shown has a nozzle body 11 , a nozzle holder 12th and a clamping nut 13th .

The nozzle body 11 takes a jet needle 14th on. The jet needle 14th is in a recess in the nozzle body 11 guided axially displaceable. In the nozzle body 11 is at least one fuel supply line 15th introduced via the fuel of a pressure chamber 16 of the nozzle body 11 can be supplied which the nozzle needle 14th surrounds in sections.

The nozzle body 11 is about the clamping nut 13th with the nozzle holder 12th axially braced, with the nozzle holder 12th likewise at least one fuel supply line 17th is introduced with a respective fuel supply line 15th of the nozzle body 11 communicates.

The nozzle holder 12th takes a feather 18th on, which is at a first end on a spring plate 19th and at an opposite second end on a spring plate 20th supports. On the spring plate 20th is a pestle 21 formed on the nozzle needle 14th acts and rests against the same.

The one from the spring element 18th The spring force is provided via the plunger 21 on the nozzle needle 14th transmitted and tends to go through the nozzle needle 14th the nozzle body 11 to close. The jet needle 14th can counter this from the spring element 18th provided spring force with opening of the nozzle body 11 be axially displaced if any of the pressure in the pressure chamber 16 dependent force greater than the spring force of the spring element 18th is.

In the exemplary embodiment shown, there are nozzle bodies 11 and nozzle holder 12th via the clamping nut 13th Axially braced directly with one another, opposite end faces 11a and 12a of nozzle body 11 and nozzle holder 12th are therefore directly adjacent to each other, so that the fuel supply lines 15th , 17th communicate directly with each other.

In contrast to this, it is also possible that between the nozzle body 11 and the nozzle holder 12th an intermediate piece (not shown) is arranged, wherein then nozzle body 11 and nozzle holder 12th with intermediate arrangement of the intermediate piece indirectly via the clamping nut 13th are braced together, in which case the end face 11a of the nozzle body 11 on an adjacent first end face of the intermediate piece and the opposite second end face of the intermediate piece on the end face 12a of the nozzle holder 12th is sealed.

If such an intermediate piece is present, at least one fuel supply line is of course also introduced into this intermediate piece, so that the respective fuel supply line is then introduced 15th of the nozzle body 11 with the respective fuel supply line 17th of the nozzle holder 12th communicates indirectly, namely via the fuel supply line of the intermediate piece (not shown) running between them.

3 shows the cross-section III-III of 1 and thus a view of the frontal area 11a of the nozzle body 11 . 3 can be seen that in the nozzle body 11 two fuel supply lines 15th are introduced, via which fuel the pressure chamber 16 of the nozzle body 11 can be fed. Accordingly, they are also in the nozzle holder 12th two fuel supply lines introduced, which are connected to the fuel supply lines 15th of the nozzle body 11 communicate directly or indirectly.

In the nozzle body 11 and the nozzle holder 12th and in the case in which the optional intermediate piece between the nozzle body 11 and the nozzle holder 12th is also arranged in the intermediate piece, intercommunicating coolant supply lines and coolant discharge lines are introduced, wherein 3 a coolant supply line 22nd and a coolant drain 23 of the nozzle body 11 in the area of the end face 11a shows about the cooling of the nozzle body 11 Coolant to the nozzle body 11 fed and from the nozzle body 11 can be discharged.

These coolant lines 22nd , 23 of the nozzle body 11 communicate with corresponding coolant lines (not shown) of the nozzle holder 12th and then, if the intermediate piece is present, with corresponding coolant lines of the intermediate piece.

To the one hand the fuel lines 15th , 17th and on the other hand the coolant lines 22nd , 23 to seal in the area of adjacent end faces is in the shown embodiment in the end face 11a of the nozzle body 11 a depression 24 introduced, which has an outer sealing surface 25th the face 11a of at least one inner sealing surface 26th the face 11a separates. In the illustrated embodiment of the 3 are two inner sealing surfaces 26th present that of the outer sealing surface 25th through the recess 24 are separated.

The respective inner sealing surface 26th the face 11a seals the respective communicating fuel lines 15th , 17th of nozzle body 11 and nozzle holder 12th in the area of the adjacent end faces 11a , 12a against each other. Should be in the area of these inner sealing surfaces 26th If a fuel leak flows, it reaches the area of the depression 24 .

The outer sealing surface 25th the face 11a seals communicating coolant lines 22nd , 23 in the area of the adjacent end faces 11a , 12a of nozzle body 11 and nozzle holder 12th against each other, with a coolant leakage over the outer sealing surface 25th flows, on the one hand inwards into the area of the depression 24 and on the other hand outwards in the direction of the clamping nut 13th can flow.

In the embodiment shown, in which nozzle body 11 and nozzle holder 12th are axially braced directly without an intermediate piece, are the sealing surfaces 25th and 26th , i.e. the outer sealing surface 25th and the inner sealing surfaces 26th , on the face 11a of the nozzle body 11 educated. However, it is also possible to use these sealing surfaces 25th , 26th alternatively or additionally on the face 12a of the nozzle holder 12th to train. To reduce manufacturing costs, however, it is preferred to use the sealing surfaces described above 25th , 26th exclusively on the face 11a of the nozzle body 11 to be provided.

The respective inner sealing surface 26th thus seals the respective fuel supply line 15th , 17th opposite the respective to the respective inner sealing surface 26th subsequent deepening 24 away. Fuel leakage reaches the area of the recess 24 .

The respective outer sealing surface 25th seals the respective coolant line 22nd , 23 opposite the depression 24 as well as to the outside. Coolant leakage can therefore also in the area of the depression 24 reach.

Then if like in 3 shown between the outer sealing surface 25th and the inner sealing surfaces 26th a common recess is formed, leakage of fuel and leakage of coolant pass together in this recess 24 and can proceed from this recess 24 via a leakage drain 27 be discharged without pressure.

The leakage process 27 extends in the area of the nozzle holder 12th radially outside on the ram 21 over, through holes 28 of the valve disc 20th through along the spring element 18th towards a hole 29 in the valve disc 19th from there via a leakage drain hole 30th from the fuel injector 10 to be led away.

The respective inner sealing surfaces 26th is a high pressure sealing surface for the respective fuel supply line 15th , 17th . The outer sealing surface 25th into a low-pressure sealing surface for the respective coolant line 22nd , 23 .

In the area of the respective inner sealing surfaces 26th a biting edge can be formed. Such a bite edge deforms plastically when the assemblies to be axially braced via the clamping nut are braced and thus increases the sealing effect.

Although in the exemplary embodiment shown, a common recess for fuel leakage and coolant leakage 24 is provided, in contrast to this, it is also possible in the area of the end face 11a to introduce separate depressions, which the outer sealing surface 25th from the inner sealing surfaces 26th separate, a first recess then serving to collect fuel leakage and a second recess to collect coolant leakage, in order to then separate these leaks via separate leakage drains from the fuel injection valve 10 to dissipate.

Then when, in contrast to the embodiment shown, between the nozzle body 11 and the nozzle holder 12th an intermediate piece is positioned and therefore nozzle body 11 and nozzle holder 12th are indirectly axially braced with intermediate arrangement of the intermediate piece, can be provided with reference to 3 described sealing surfaces 25th , 26th on the one hand on the front face 11a of the nozzle body 11 and on the other hand on that of the nozzle body 11 remote end face of the intermediate piece, which is on the end face 12a of the nozzle holder 12th comes to the plant to train.

It is also possible to have the sealing surfaces on both opposite end faces of the intermediate piece 25th , 26th train so that then the end faces 11a and 12a of nozzle body 11 and nozzle holder 12th , which come to rest on the end faces of the intermediate piece, are conventionally designed, that is, without the recess 24 which are the sealing surfaces 25th , 26th trains and separates from each other.

The in 3 shown recesses 28 These are bores for receiving dowel pins that align the nozzle body 11 and nozzle holder 12th When assembling serve to the in nozzle body 11 and nozzle holder 12th running fuel lines 15th , 17th and coolant lines 22nd , 23 to align precisely and in a defined manner.

The invention accordingly proposes a fuel injection valve cooled with coolant, in which fuel lines and coolant lines are sealed by spatially and functionally separate sealing surfaces. Fuel is prevented from escaping into the environment. Fuel leakage and coolant leakage can be discharged in a defined manner.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19827628 A1 [0002, 0003]
• DE 19914720 B4 [0004]

Claims (10)

Fuel injection valve (10) for an internal combustion engine, with a nozzle body (11) which receives a nozzle needle (14), at least one fuel supply line (15) being introduced into the nozzle body (11), which is fed into a pressure chamber surrounding the nozzle needle (14) in sections (16) of the nozzle body (11) opens with a nozzle holder (12), at least one fuel supply line (17) being introduced into the nozzle holder (12), which connects directly or indirectly to a respective fuel supply line (15) of the nozzle body (11) a respective coolant supply line of an intermediate piece communicates with a clamping nut (13) via which the nozzle body (11) and nozzle holder (12) are axially braced either directly or indirectly via the intermediate piece with sealing of abutting end faces (11a, 12a), characterized in that coolant supply lines (22) communicating with one another in the nozzle body (11) and in the nozzle holder (12) and in the optional intermediate piece d coolant discharge devices (23) are introduced, via which coolant can be supplied to the nozzle body (11) and removed from the nozzle body (11) for cooling the nozzle body (11), on the end face (11a) of the nozzle body (11) and / or on the an outer sealing surface (25) and at least one inner sealing surface separated from the outer sealing surface (25) by at least one recess (24) (26), wherein the respective inner sealing surface (26) seals the respective communicating fuel supply lines (15, 17) in the area of the adjacent end faces (11a, 12a), and the respective outer sealing surface (25) seals the respective communicating coolant lines ( 22, 23) in the area of the adjacent end faces (11a, 12a). Fuel injector after Claim 1 , characterized in that when the nozzle body (11) and nozzle holder (12) are directly axially braced, on the end face (11a) of the nozzle body (11) which is directly adjacent to the end face (12a) of the nozzle holder (12), the outer sealing surface (25) and the respective inner sealing surface (26) are formed. Fuel injector after Claim 1 , characterized in that when the nozzle body and nozzle holder are axially braced indirectly via the intermediate piece, on the end face of the nozzle body, which is directly adjacent to a first end face of the intermediate piece, and on an opposite second end face of the intermediate piece, which is directly on the end face of the Nozzle holder adjoins, in each case the outer sealing surface and the respective inner sealing surface are formed. Fuel injector after Claim 1 , characterized in that when the nozzle body and nozzle holder are axially braced indirectly via the intermediate piece, on a first end face of the intermediate piece, which is directly adjacent to the end face of the nozzle body, and on an opposite second end face of the intermediate piece, which is directly on the end face of the Nozzle holder adjoins, in each case the outer sealing surface and the respective inner sealing surface are formed. Fuel injection valve according to one of the Claims 1 until 4th , characterized in that the respective recess (24) communicates with a leakage drain (30) in the area of the nozzle holder (12), via which leakage collecting in the area of the respective recess (24) can be discharged from the fuel injection valve. Fuel injection valve according to one of the Claims 1 until 5 , characterized in that the respective inner sealing surface (26) seals the respective fuel supply line (15, 17) against the respective recess (24) adjoining the respective inner sealing surface (26). Fuel injection valve according to one of the Claims 1 until 6th , characterized in that the respective outer sealing surface (25) seals the respective coolant line (22, 23) against the respective recess (24) adjoining the respective outer sealing surface (25) and to the outside. Fuel injection valve according to one of the Claims 1 until 6th , characterized in that the respective outer sealing surface (25) seals the respective recess (24) adjoining the respective outer sealing surface (25) to the outside. Fuel injection valve according to one of the Claims 1 until 8th , characterized in that the respective outer sealing surface (26) and the respective inner sealing surface (26) are separated by a common recess (24) for fuel leakage and coolant leakage. Fuel injection valve according to one of the Claims 1 until 8th , characterized in that the respective outer sealing surface and the respective inner sealing surface are separated by separate depressions for fuel leakage and coolant leakage.

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