DE102004014198B3 - Servo valve and injector - Google Patents

Abstract

An injection valve has a valve drive, a servo valve, a first nozzle needle and a second nozzle needle. the first nozzle needle releases at least one first injection nozzle in its open position. In its closed position, it prevents the fluid flow through the first injection nozzle. The second nozzle needle releases the fluid flow through at least one second injection nozzle in its open position and prevents the fluid flow through the at least second injection nozzle in its closed position. The position of the first and second nozzle needle is controllable by means of the servo valve. The servo valve has a valve body (16) having a recess (38) and a seat (41) which is formed in a region of the recess (38). Furthermore, an outer piston (40) is provided, which is introduced into the recess (38) of the valve body (16) and which has a conical shoulder (42) which cooperates with the seat (41) of the valve body (16) it in the closed position of the outer piston (40) sealingly against the seat (41) of the valve body (16) and having a recess (44), in the region of a seat (46) of the outer piston (40) is formed. DOLLAR A An inner piston (48) is inserted in the recess (44) of the outer piston (40) and has a conical shoulder (50) which cooperates with the seat (46) of the outer piston (40) the closing position of the inner piston (48) sealingly abuts against the seat (46) of the outer piston (40). ...

Description

The The invention relates to a servo valve and an injection valve with a Servo valve.

always Stricter legal regulations regarding permissible pollutant emissions of internal combustion engines, which are arranged in motor vehicles, make it necessary to carry out various measures that pollutant emissions are lowered. A starting point here is the pollutant emissions generated by the internal combustion engine to lower. Another starting point is that of the internal combustion engine emissions generated by exhaust aftertreatment systems in harmless Transform substances. The formation of soot is highly dependent on the preparation of the air / fuel mixture in the respective Cylinder of the internal combustion engine. To a correspondingly improved To achieve mixture preparation, fuel is increasingly under metered very high pressure. In the case of diesel internal combustion engines amount to the fuel pressures up to 2,000 bar.

Furthermore, what are known as register nozzle injection valves have become known with two injection nozzle circuits and associated first and second nozzle needles, by means of which a stepwise opening or closing of the individual injection nozzle circuits is possible. So is out of the EP 0 978 649 A2 such a valve known. The valve has a housing in which a designed as a piezo actuator valve drive and a nozzle body are arranged. The nozzle body has a first series of injection holes and axially spaced therefrom a second series of injection holes. In a recess of Düsenkör pers a nozzle needle is guided, which in its closed position prevents the flow of fuel through both the first and the second series of injection holes and releases at least the fuel flow through the first series of injection holes in its open position.

The nozzle needle works over a driver mechanism on an insert body having an inner nozzle needle forms. The inner nozzle needle prevents in their closed position a fuel flow through the second series of injection holes and gives the other positions the fuel flow through the second row of injection holes free. The piezo actuator acts via a servo valve on the nozzle needle one. The servo valve comprises a drain hole, a valve stem, a closing element, a control chamber and a leakage chamber. By a corresponding Controlled expansion of the piezo actuator is via the locking bar the closing member of pushed away from his tight seat. This has the consequence that fuel flows out of the control chamber. By the associated decrease in pressure in the control chamber opens or the nozzle needle moves from their closed position towards their open position. As a result, they first the first Row of injection holes releases and with decreasing pressure in the control chamber then via the driver mechanism the inner nozzle needle from their closed position is moved into its open position and thus the second Row of injection holes is released. The first row of injection holes is formed so that their cross section is significantly smaller than the cross section of the injection holes of second row. As a result, the fuel passing through the first row of injection holes is measured in the combustion chamber of the internal combustion engine, clearly finely atomised becomes. This is especially in partial load operation of the internal combustion engine advantageous in which injected a smaller amount of fuel and then by the smaller diameter of the injection holes smaller drops of fuel are formed and thus the formation of soot is reduced. Due to the much larger diameter of the second Row of injection holes can then be guaranteed at full load the internal combustion engine be that sufficient amount of fuel in each Burning chamber of the cylinder is metered.

From the EP 1 063 421 A2 a fuel injection valve is known, which opens to the outside. It has a nozzle body that includes a first bore and a valve needle slidably disposed in the bore and engageable with a seat to control the delivery of fuel from the bore. There are provided first and second control chambers for receiving pressurized fuel and control valves for controlling the fuel pressure in the first and second control chambers, respectively. The valve needle is movable depending on a change in the fuel pressure in at least one of the first or second control chambers.

From the DE 103 09 387 A1 is also a fuel injection device known with a valve element having a through hole. When the valve member is fitted against a valve seat, fuel flow from an upstream side of fuel injection holes is blocked in the fuel injection holes. A rod is inserted in the through hole and a valve member is reciprocable relative to the rod. When the valve member is seated against the valve seat, a locking portion of the rod is engaged with a hole seat. Thus, a flow of the fuel from the through hole into the injection holes is blocked. A pressure receiving surface of the valve element that receives the fuel pressure from the high pressure fuel in a control chamber is ei NEN amount of a cross-sectional area of the through hole is reduced, so that a force that is applied to the valve element of the fuel in the control chamber in a Aufsetzrichtung is reduced.

The The object of the invention is to provide a servo valve that is suitable is for controlling a first and second nozzle needle of an injection valve and that is simple and compact. It is also the object of the invention to provide an injection valve with a first and second nozzle needle, that is simple and compact.

The Task is solved by the characteristics of the independent Claims. Advantageous embodiments of the invention are characterized in the subclaims.

According to the first Aspect of the invention, it is characterized by a servo valve, especially for an injection valve, with a valve body having a recess and a seat formed in a region of the recess is. Further, an outer piston provided, which is introduced into the recess of the valve body and the a cone-shaped Paragraph that interacts with the seat of the valve body so that he in the closed position of the outer bulb at the seat of the valve body sealingly rests. The outer piston has a recess in the area of which a seat of the outer bulb is trained. Further, an inner piston is provided which in introduced the recess of the outer piston is and a conical one Paragraph so interacting with the seat of the outer piston that he is in the closed position the inner piston sealingly abuts the seat of the outer piston. An sealing sleeve is provided, which are arranged in the recess of the inner piston is and has a circumferential sealing edge on the free end is formed, which faces away from the seat of the outer piston. The sealing sleeve is biased by a first spring in the direction of the sealing edge. Further, a first drain hole is formed, which with the recess of the outer bulb in the area within the sealing edge of the sealing sleeve hydraulically is coupled. A second drain hole is with the recess of the valve body in the area outside the sealing edge of the sealing sleeve hydraulically coupled. A leakage space is dependent on the position of the inner Piston with the first drain hole hydraulically coupled or decoupled and is dependent from the position of the outer piston with the second drain hole hydraulically coupled or decoupled. The outer piston and the inner piston each have a contact surface, the is provided that a valve actuator acts on it.

According to the other Aspect of the invention, it is characterized by an injection valve with a valve drive and the servo valve. The injection valve further includes a first nozzle needle and a second nozzle needle. The first nozzle needle is arranged in the injection valve so that it flows the fluid released by at least one first injection nozzle in its open position and in their closed position prevented. The second nozzle needle is arranged in the injection valve so that it flows through the fluid releases at least one second injection nozzle in its open position and in their closed position prevented. The servo valve is arranged in the injection valve, that by means of the servo valve, the position of the first and the second nozzle needle is controllable.

The Servovalve allows in a simple and compact way that fluid over the first drain hole is controlled without necessarily fluid over the second drain hole is shut down. It thus allows in the injection valve, that the first nozzle needle separated from the second nozzle needle from their closed position can be controlled in their open position and vice versa.

In An advantageous embodiment of the invention is the inner piston coaxial with the outer piston arranged. As a result, the servo valve for a particularly compact on the other hand, the actuator can be central both on the inner than on the outer piston act and have to no lever arrangements are provided and also the risk of Jamming of the inner or outer piston is extremely low.

In a further advantageous embodiment of the invention is based the first spring on the one hand on a shoulder of the inner piston and on the other hand on a paragraph of the sealing sleeve. That's how she stretches the first sealing sleeve before as well as the inner piston and the outer piston in their closed positions in front.

In a further advantageous embodiment of the invention is a second spring and a spring holder provided so with the outer piston coupled, that they are the outer piston in its closed position pull, if no further forces on the outer piston act. This results in a particularly compact arrangement, in particular, when the second spring and the spring holder in the leakage chamber are arranged. About that In addition, the intrinsic safety of the servo valve can be guaranteed become.

In a further advantageous embodiment of the invention, the outer diameter of the conical shoulder of the outer piston is greater than the diameter of its recess in the Be rich of the sealing sleeve. As a result, the outer piston is also pressed outside of the closed position of the inner piston in its closed position, as long as the valve drive does not act on the outer piston. As a result, it can be ensured during operation of the servo valve or of the injection valve that no unintentional opening of the servo valve takes place.

In a further advantageous embodiment of the invention is the first nozzle needle as inner nozzle needle trained and the second nozzle needle as an outer nozzle needle formed, which is arranged coaxially with the inner nozzle needle. Further is a control room provided with the inner and outer nozzle needle coupled, wherein the first drain hole in alignment with the inner nozzle needle flows into the control room and the inner and outer nozzle needle are formed so that the inner nozzle needle at a higher pressure moved in the control room from its closed position to its open position as the outer nozzle needle and the inner nozzle needle in its open position, the first drain hole hydraulically from the Control room decoupled. This is a simple separate control of inner and outer nozzle needles guaranteed.

In a further advantageous embodiment of the invention is the first drain hole formed as a spring pocket, which is a nozzle spring picks up the first nozzle needle in their closed position biases. As a result, the injection valve is extremely compact and simple.

embodiments The invention are explained below with reference to the schematic drawings. It demonstrate:

1 an injection valve with a servo valve and

2 an enlargement of the injection valve according to 1 in the area of the servo valve.

elements same construction and function are cross-figurative with the same Reference number marked.

An injection valve ( 1 ) has an injector housing 1 , In a recess 2 of the injector housing 1 an actuator is arranged, preferably as a piezo actuator 4 is trained. The piezo actuator 4 is formed as a stack of piezoelectric elements and changes its axial extent depending on the electrical energy supplied or discharged. The piezo actuator 4 is with a transformer 6 coupled. The transformer 6 is also in the recess 2 of the injector housing 1 arranged. The piezo actuator 4 is over an O-ring 8th in the recess 2 centered. A bellows 10 seals the piezo actuator from that in the recess 2 located fluid medium from. The bellows 10 is on the one hand with a pressed ring 12 welded and on the other hand with the transformer 6 welded. The bellows 10 and the pressed ring 12 opposite the piezo actuator 4 separated space forms a leakage space 14 , The leakage chamber is hydraulically coupled by means of a Le ckagebohrung not shown with a low pressure region of a fuel supply for the injection valve.

The injection valve further comprises a valve body 16 , an intermediate plate 18 , a needle guide body 20 and a nozzle body 21 , The valve body 16 , the intermediate plate 18 , the needle guide body 20 and the nozzle body 21 form a nozzle assembly by means of a nozzle locknut 22 on the injector housing 1 is attached.

The nozzle body 21 has a recess 24 in which an inner nozzle needle 26 and an outer nozzle needle 28 are arranged. The outer nozzle needle 28 is in the needle guide body 20 guided. The inner nozzle needle 26 is coaxial with the outer nozzle needle 28 in a recess 29 the outer nozzle needle arranged and guided in this. The recess 29 the outer nozzle needle 28 penetrates the outer nozzle needle 28 in the axial direction completely. A first nozzle spring 32 is arranged so that it has the inner nozzle needle 26 biased in one of these associated closed position in which they the fuel flow through at least one first injection nozzle 36 in derogation.

A second nozzle spring 30 clamps the outer nozzle needle 28 in a closed position, in which they the fuel flow through at least one second injection nozzle 34 in derogation.

A servo valve comprises the valve body 16 in which a recess 38 of the valve body 16 is trained. An outer piston 40 is in the recess 38 of the valve body 16 brought in. In the recess 38 of the valve body 16 is a seat 41 educated. The outer piston 40 has a cone-shaped heel 42 in a closed position of the outer piston sealing to the seat 41 of the valve body 16 is applied. The outer piston 40 has a recess 44 into which an inner piston 48 is introduced. The outer piston 40 has in the area of its recess 44 a seat 46 ,

The inner piston 48 has a cone-shaped heel 50 which is in a closed position of the inner piston 48 at the seat 46 of the outer bulb 40 sealingly rests.

Further, in the recess 44 of the outer bulb 40 a sealing sleeve 52 introduced, the one circumferential sealing edge 54 that's on her seat 46 of the outer bulb 40 opposite side is formed. The sealing sleeve 52 is by means of a first spring 56 in the direction of the sealing edge 54 biased and thus lies with the sealing edge 54 sealing on the intermediate plate 18 on. The first spring 56 on the one hand relies on a paragraph 58 of the inner piston 48 on the other hand, it relies on a heel 60 the sealing sleeve 52 from. By this arrangement of the first spring 56 on the one hand, the sealing sleeve 52 with its sealing edge 54 sealing on the intermediate plate 18 pressed and on the other hand, the inner piston 48 with its conical heel 50 in the seat 46 of the outer bulb 40 pressed and thus sealingly on this, if no other forces on the inner piston 48 through the piezo actuator 4 be exercised. In addition, the first spring presses 56 on the outer piston 40 sealing in the seat 41 of the valve body 16 with its conical heel 42 as long as that by the outer piston 40 surrounding hydraulic fluid caused forces are not greater than those caused by the bias of the first spring 56 applied force and provided by the piezo actuator 4 no forces acting in the opening direction are applied.

Preferably, the outer radius of the conical shoulder 42 of the outer bulb 40 greater than the outer radius of the sealing sleeve 52 and thus the radius of the recess 44 of the outer bulb 40 in the area of the sealing sleeve 52 , This has the advantage that due to the pressure of the hydraulic fluid, which is the outer piston 40 in the region of the recess 38 of the valve body 16 surrounds, the resulting force acting on the outer piston 40 acts, the outer piston 40 in the seat 41 of the valve body 16 with its conical heel 42 suppressed. This is the outer piston 40 regardless of the pressure of the hydraulic fluid surrounding it, in its closed position, when no corresponding forces via the piezo actuator 4 on the outer piston 40 be exercised. Furthermore, the first spring also acts 56 closing on the outer piston 14 because the force exerted by it is above the cone-shaped shoulder 50 of the inner piston 58 on the seat 46 of the outer bulb 40 and then on the cone-shaped paragraph 41 of the outer bulb 40 transfers.

For additional assurance that the outer piston 40 is in its closed position, if none of these counteracting forces by the piezo actuator 4 can be exercised, a pen 62 with the outer piston 40 be coupled, on which a second spring 64 supported on the one hand. The second spring 64 On the other hand, it rests on a floor of the leakage space 14 from. By means of the arrangement of the second spring 64 and the penholder 62 so will the outer piston 40 pulled into its closed position. By this arrangement, the second spring can 64 extremely compact the already existing leakage chamber 14 be arranged.

In the intermediate plate 18 is a first drain hole 66 introduced, starting from the valve body 16 facing side towards a pencil case 68 is guided. The pencil case 68 extends to the needle guide body 20 facing side of the intermediate plate 18 , The pencil case 68 flows into a control room 70 in the needle guide body 20 is trained.

A second drain hole 72 is from the control room 70 towards the side of the intermediate plate 18 guided, which the valve body 16 is facing. The first drain hole 66 is so hydraulically coupled with the spring bag 68 and, on the other hand, is hydraulically coupled to the recess 44 of the outer bulb 40 in the area inside the sealing edge 54 the sealing sleeve 52 , The second drain hole 72 couples the control room 70 hydraulically with the recess 38 of the valve body 16 in the area outside the sealing edge 54 the sealing sleeve 52 ,

A high pressure bore 74 penetrates the valve body 16 , the intermediate plate 18 , the needle guide body 20 and the nozzle body 21 and thus leads fuel under high pressure, for example up to 2,000 bar, to the at least first and second injection nozzle 34 . 36 ,

A first inlet throttle 76 couples the high pressure hole 74 hydraulically with the spring bag 68 , A second inlet throttle 78 couples the high pressure hole 74 hydraulically with the control room 70 and the second drain hole 72 , The control room 70 is limited in a range by a contact surface 80 the inner nozzle needle 26 and a contact surface 82 the outer nozzle needle 28 , The one in the pencil case 68 located second nozzle spring 32 rests on the contact surface 80 the inner nozzle needle 26 and thus tensioning them in the direction of their closed position.

If the piezo actuator 4 is driven in such a way that it is in the axial direction towards the inner and outer pistons 40 . 48 expands, first the inner piston is moved from its closed position to an open position, ie away from its abutment against the seat 46 of the outer bulb 40 emotional. For this purpose, a contact surface of the inner piston protrudes 40 to the transmitter 6 via a corresponding contact surface of the outer bulb 40 to the transmitter 6 out.

If then the inner piston 48 in egg ner position away from its closed position, fluid flows from the control room 70 through the pencil case 68 , the first drain hole 66 and through the recess 44 the outer piston along the conical shoulder 50 towards the leakage room 14 , in which there is a low fluid pressure. With the flow of fluid from the control room 70 there is a pressure drop in the control room 70 associated. This pressure drop has the consequence that the fluid in the control room 70 caused forces on the contact surface 80 the inner nozzle needle 26 and the contact area 82 the outer nozzle needle can be reduced. The inner and outer nozzle needle 26 . 28 also have paragraphs that are hydraulically coupled to the high pressure bore 74 and which are formed so that the forces caused by the pressure of the fluid in the high-pressure bore opening on the first and second nozzle needle 26 . 28 Act. These forces thus counteract the forces caused by the pressure of the hydraulic fluid in the control chamber 70 on the contact surfaces 80 . 82 the first and second nozzle needle 26 . 28 act. With progressive drop in pressure in the control room 70 the force balance of these forces shifts in favor of the forces of the hydraulic fluid, which open onto the first and second nozzle needle 26 . 28 Act. The first contact surface 80 and a corresponding shoulder on the inner nozzle needle 26 and the contact area 82 and a corresponding shoulder on the outer nozzle needle 28 are sized so that the inner nozzle needle 26 moved to its open position at a higher pressure value from its closed position than that for the outer nozzle needle 28 the case is.

The pressure in the control room drops 70 under the pressure, at which the inner nozzle needle 26 moved from its closed position to its open position, the inner nozzle needle moves toward a stop of the control chamber 70 at the intermediate plate 80 , The pencil case 68 flows into the control room 70 in the area of this stop, and in alignment with the inner nozzle needle 26 , By this arrangement it is achieved that when the inner nozzle needle 26 in its open position, ie at the stop of the control room 70 in or on the intermediate plate 18 is formed, another drain of fluid through the spring pocket 68 and continue through the drainage channel 66 and finally to the leakage space is prevented. In this state, although fluid flows through the first inlet throttle 76 towards the pencil case 68 , However, this fluid can through the first drain hole 66 and through the recess 44 of the outer bulb 40 in the leakage room 14 drain and thus results in the spring pocket no pressure increase, which leads to a moving away of the inner nozzle needle 26 would lead from their open position, with suitable dimensioning of the inlet throttle 76 ,

Then becomes the stroke of the piezo actuator 4 again so reduced that the inner piston 48 sealing again with its cone-shaped heel 50 at the seat 46 of the outer bulb 40 is applied, so no more fluid through the first drain channel 66 drain and that via the first inlet throttle 76 incoming fluid causes an increasing pressure in the spring pocket 68 , which eventually causes the inner valve needle 80 moved from its open position back to its closed position.

However, by appropriate control of the piezo actuator 4 the stroke of the piezoelectric actuator continues towards the inner and outer pistons 48 . 40 increased, so eventually the outer piston 40 from its sealing attachment with its conical heel 42 at the seat 41 of the valve body 16 moved away and so brought into its open position. In the open position of the outer piston 14 can that be in the control room 70 located fluid via the second flow channel 72 through the recess 38 of the valve body 16 past the seat 41 of the valve body 16 in the leakage room 14 stream. This then results in a further pressure drop in the control room 70 which eventually causes the outer nozzle needle as well 28 moved from its closed position to its open position. About the second inlet throttle 78 In this state, fluid flows into the control room 70 and from this then on through the second drain hole 72 and the recess 38 of the valve body 16 in the leakage room. With suitable dimensioning of the inlet throttle, however, the pressure in the control chamber increases as long as the coupling to the leakage chamber 14 is given, not to a value that causes a renewed movement of the outer nozzle needle 28 would lead to their closed position.

Then becomes the stroke of the piezo actuator 4 again reduced so that the outer piston 44 with its cone-shaped heel 42 back at the seat 41 of the valve body 16 sealingly abuts, so no more fluid through the second drain hole 72 drain and that via the second inlet throttle 78 Influent fluid causes a pressure increase in the control room 70 which eventually causes the outer nozzle needle 28 moved again from its open position to its closed position.

The nested arrangement of the inner and outer pistons 48 . 40 allows in cooperation with the sealing sleeve 52 the function of two servo valves in a very compact way. Furthermore, the piezo actuator 4 over the transformer 6 directly on both the inner piston 48 as well as on the outer piston 40 act. There are thus no additional levers or the like required. Due to the concentric arrangement of the inner and outer pistons 48 . 40 can also use the powers of the piezo actuator 4 over the transformer 6 be transmitted centrally.

Claims (8)

Servo valve, in particular for an injection valve, with - a valve body ( 16 ), which has a recess ( 38 ) and has a seat ( 41 ), which in a region of the recess ( 38 ), - an outer piston ( 40 ), which in the recess ( 38 ) of the valve body ( 16 ) having a conical shoulder ( 42 ), who has the seat ( 41 ) of the valve body ( 16 ) cooperates so that the conical shoulder ( 42 ) in the closed position of the outer piston ( 40 ) at the seat ( 41 ) of the valve body ( 16 ) sealingly abuts, and the one recess ( 44 ), in whose area a seat ( 46 ) of the outer bulb ( 40 ), - an inner piston ( 48 ), which in the recess ( 44 ) of the outer bulb ( 40 ) and a cone-shaped shoulder ( 50 ), who has the seat ( 46 ) of the outer bulb ( 40 ) cooperates so that the conical shoulder ( 50 ) in the closed position of the inner piston ( 48 ) at the seat ( 46 ) of the outer bulb ( 40 ) sealingly rests, - a sealing sleeve ( 52 ), which are in the recess ( 44 ) of the outer bulb ( 40 ) is arranged and a circumferential sealing edge ( 54 ), which on the free end of the sealing sleeve ( 52 ), which is the seat ( 46 ) of the outer bulb ( 40 ) facing away, wherein the sealing sleeve ( 52 ) by means of a first spring ( 56 ) in the direction of the sealing edge ( 54 ), - a first drain hole ( 66 ), which with the recess ( 44 ) of the outer bulb ( 40 ) in the area within the sealing edge ( 54 ) of the sealing sleeve ( 52 ) is hydraulically coupled, - a second drain hole ( 72 ), which with the recess ( 38 ) of the valve body ( 16 ) in the area outside the sealing edge ( 54 ) of the sealing sleeve ( 52 ) is hydraulically coupled, and - a leakage chamber ( 14 ), which depends on the position of the inner piston ( 48 ) with the first drain hole ( 66 ) is hydraulically coupled or decoupled and which depends on the position of the outer piston ( 40 ) with the second drain hole ( 72 ) is hydraulically coupled or decoupled from this, wherein the outer piston ( 40 ) and the inner piston ( 48 ) each have a contact surface, which are provided so that a valve drive acts on them. Servo valve according to Claim 1, in which the inner piston ( 48 ) coaxial with the outer piston ( 40 ) is arranged. Servo valve according to one of the preceding claims, in which the first spring ( 56 ) on the one hand on a paragraph ( 58 ) of the inner piston ( 48 ) and, on the other hand, on a paragraph ( 60 ) of the sealing sleeve ( 52 ) is supported. Servo valve according to one of the preceding claims, in which a second spring ( 64 ) and a penholder ( 62 ) provided with the outer piston ( 40 ) are coupled to the outer piston ( 40 ) in its closed position, if no further forces on the outer piston ( 40 ). Servo valve according to one of the preceding claims, in which the outer diameter of the conical shoulder ( 42 ) of the outer bulb ( 40 ) is greater than the diameter of the recess ( 44 ) of the outer bulb ( 40 ) in the region of the sealing sleeve ( 52 ). Injection valve with - a valve drive, - a servo valve according to one of the preceding claims, - a first nozzle needle ( 26 ) and a second nozzle needle ( 28 ), wherein the first nozzle needle ( 26 ) the fluid flow through at least one first injection nozzle ( 36 ) in its open position and prevented in its closed position and the second nozzle needle ( 28 ) the fluid flow through at least one second injection nozzle ( 34 ) in its open position and prevented in its closed position and the position of the first and second nozzle needle ( 26 . 28 ) is controllable by means of the servo valve. Injection valve according to claim 6, with - an inner nozzle needle ( 26 ) formed first nozzle needle, - one as an outer nozzle needle ( 28 ) formed second nozzle needle coaxial with the inner nozzle needle ( 26 ), - a control room ( 70 ), with the inner nozzle needle ( 26 ) and the outer nozzle needle ( 28 ), - wherein a first drain hole ( 66 ) in alignment with the inner nozzle needle ( 26 ) in the control room ( 70 ) and the inner and outer nozzle needle ( 26 . 28 ) are formed so that the inner nozzle needle ( 26 ) at a higher pressure in the control room ( 70 ) as the outer nozzle needle ( 28 ) moves from its closed position into its open position and the inner nozzle needle ( 26 ) in its open position, the first drain hole ( 66 ) hydraulically from the control room ( 70 ) decoupled. Injection valve according to one of claims 6 or 7, in which the first drain hole ( 66 ) as a spring bag ( 68 ) is formed, which is a nozzle spring ( 32 ) receiving the first nozzle needle ( 26 ) is biased in its closed position.