DE102008007203A1 - Compact injection device with pressure-controlled nozzle - Google Patents

Abstract

The invention relates to an injection device, comprising a fuel pump (20a), a pressure regulator (20b), an injector (20c) and an aerator (20d), wherein the fuel pump (20a), the pressure regulator (20b), the injector (20c) and the Air actuator (20d) are an integral part of an injection module (2) and the injector (20c) comprises a pressure-controlled nozzle (40) with a pressure chamber (41), a nozzle body (44) and a membrane (42).

Description

State of the art

The The present invention relates to an injection device with a Fuel pump, a pressure regulator, an injector with pressure-controlled nozzle and an air actuator in a compact design.

Injectors are known from the prior art in different embodiments. Especially for cost and space reasons require small combustion engines, which only one or two cylinders and a small displacement have independent solutions. applications Such small internal combustion engines are for example two-wheeled vehicles or tricycles or lawnmowers etc. Known injectors commonly include in a tank a fuel pump with a pressure regulator, where the fuel pump with a predetermined pressure in a line, z. B. a rail o. Ä., Promotes. At the End of the line, an injector is arranged, which, controlled by a control device, fuel in a suction pipe or directly injected into a combustion chamber. Such injectors However, they are very expensive and especially expensive, so they are small-fuel engines also very expensive.

From the EP 1 340 906 B1 For example, an electronic control fuel injection device is known in which an injector is disposed near a pump piston. Further, in this case, a pre-pressure valve is provided for exerting an admission pressure on the fuel in an initial phase of a pressure stroke of the piston in the return line of the fuel to the tank. The admission valve evacuates a part of the fuel located in a pressure chamber in the return line. In this way, in particular the formation of vapor bubbles in the injector can be reduced. However, the structure is relatively complicated and the device takes up a large amount of space.

Advantages of the invention

The Inventive injection device with the Features of claim 1, in contrast, the Advantage on that it has a very compact structure. Further can the injection device according to the invention be made particularly simple and inexpensive. As a result, the injection device according to the invention especially in small combustion engines, eg. B. in two-wheeled vehicles or lawnmowers or the like. This is inventively achieved in that the Injection device, a fuel pump, a pressure regulator for Control of an injection pressure, an injector with pressure-controlled Nozzle and an air actuator includes which integral components an injection module are. The injection module is a compact, small component in which the fuel pump, the pressure regulator, the injector and the air plate are arranged. Because the injector includes a pressure-controlled nozzle, the injector can be particularly be provided easily and inexpensively. The pressure-controlled The nozzle comprises a pressure chamber, a nozzle body and an elastic membrane. According to the invention understood by the term elastic membrane an elastic component, which a predetermined deformation at a pressure increase in the pressure chamber provides to start from a predetermined pressure level to allow injection of fuel in the pressure chamber. Through the pressure-controlled nozzle, the injection device thus a very simple and inexpensive construction. The injection module can be completely pre-assembled, so that it only connected to the necessary connections and can be installed directly into a vehicle. The Components of the injection module are preferably in a common Housing of the injection module arranged. In addition to the compactness of the injection module is another big advantage that Other components for the injection module can be minimized can. As a result, the invention is suitable Injection device especially for use in small machines.

The Subclaims show preferred developments of the invention.

The Injection device preferably comprises an actuator, which simultaneously actuates the fuel pump and the aerator. In particular, in each case a separate actuator for the Air actuator or the fuel pump omitted, so that the number of components is significantly reduced. This of course results also a cost reduction. Thus, the common actuator takes over first, the function of the pump drive and second, the function the actuator for the air actuator.

Preferably the nozzle body of the injector comprises a sealing seat. At the sealing seat, the membrane is applied and the membrane has at least an injection port on. Thus, the membrane has in addition the effect of a closing member for the injector, wherein the membrane lifts off from the sealing seat when the pressure in the pressure chamber over has increased to the predetermined pressure, so that fuel through the Gap between the sealing seat and the membrane can flow and are ejected from the injection port of the membrane can. This allows the parts number of the pressure-controlled nozzle be kept very low.

According to another preferred embodiment circuit of the present invention, the pressure-controlled nozzle comprises a closing body, which is arranged on a side facing the pressure chamber of the membrane on the membrane. Thereby, the membrane is given an improved stability, so that in particular a tearing of the membrane during operation can be avoided. The pressure-controlled nozzle thus has a longer life. The closing body can be attached to the membrane, for example, by gluing or welding. In order to have the simplest possible construction, the sealing seat on the nozzle body is preferably annular. This also has fluidic advantages during the injection process.

Further Preferably, the membrane is directly on the nozzle body fixed. The membrane is preferably by means of laser welding attached to the nozzle body, wherein the nozzle body at the area in which the membrane is to be fastened, preferably is cylindrical. This makes it possible for them to membrane has a structure similar to a hemisphere or shell.

According to one preferred alternative of the present invention comprises the nozzle body the pressure-controlled nozzle a sealing seat and the membrane is connected to a closing body. The closing body works with the sealing seat and gives a gap between Closing body and sealing seat for one Injection of fuel free or closes this again. By providing the closing body on the membrane can also have a long life of the pressure-controlled Nozzle can be ensured. The closing body is preferably a ball, wherein the membrane at the maximum Scope of the ball is fixed.

According to one further preferred embodiment of the present invention the pressure-controlled nozzle preferably a reset element, to return the membrane to its original position. This allows a return of the membrane faster be made possible, and the membrane from a cost-effective, be made flexible material.

Further Preferably, a stop is provided to a hub of the membrane to limit. This will ensure that the membrane is not due is damaged too large a stroke.

According to one Another preferred embodiment of the invention is the membrane connected with a sealing ring. The sealing ring is radial Game arranged in an annular groove, wherein the annular groove in the nozzle body is formed. As a result, the membrane has over the sealing ring a radial play, so that they work together with a closing body in the sealing seat can center. The sealing ring is preferably a O-ring.

Further Preferably, the membrane comprises at least one or more concentric Waves. Due to the concentric waves, the membrane has a softer Behavior on.

Preferably the fuel pump comprises a pumping chamber and also a first, a second and a third check valve, which on Supply lines or discharges of the pumping chamber are arranged. in this connection is the first check valve between a supply area arranged for fuels and the pumping chamber. The second Check valve is between the pumping chamber and the injector arranged and the third check valve is between the pumping chamber and a discharge area or return area arranged by pressure peaks. The use of the pumping chamber allows doing a particularly compact and thus space-saving and cost-effective Structure and may preferably be on a common axis with the Anchor of the actuator can be arranged. The pumping chamber points preferably a volume which is one volume of a maximum injectable Fuel quantity at maximum injection pressure corresponds.

Further The present invention relates to an internal combustion engine, which exactly one cylinder or exactly two cylinders and an inventive Fuel injection device comprises. Particularly preferred the internal combustion engine a fuel tank, which above the Injection module is arranged. As a result, in particular, the fuel pump be designed very small.

drawing

following preferred embodiments of the invention below Reference to the accompanying drawings described in detail. In the drawing is:

1 a schematic view of a small motor with an injection device according to a first embodiment of the invention,

2 a schematic view of the injection device according to the first embodiment,

3 a schematic sectional view of a pressure-controlled nozzle according to the first embodiment,

4 a schematic sectional view of a pressure-controlled nozzle according to a second embodiment of the invention,

5 a schematic sectional view of a pressure-controlled nozzle according to a third embodiment of the present invention,

6 FIG. 2 a schematic sectional view of a pressure-controlled nozzle according to a fourth exemplary embodiment of the present invention, FIG.

7 FIG. 2 a schematic sectional view of a pressure-controlled nozzle according to a fifth exemplary embodiment of the present invention, FIG.

8th a schematic sectional view of a pressure-controlled nozzle according to a sixth embodiment of the present invention, and

9 a schematic sectional view of a pressure-controlled nozzle according to a seventh embodiment of the present invention.

Preferred embodiments the invention

The following is with reference to the 1 to 3 a small engine 1 with an injection device according to the invention according to a first embodiment described in detail.

1 schematically shows the structure of the small motor 1 , which is designed as a single-cylinder engine. The small engine 1 includes a cylinder 3 , a reciprocating piston 4 , a control unit 5 and a tank 6 , The Tank 6 is via a fuel supply line 6a with an injection module 2 connected. A fuel return line 6b goes from the injection module 2 back to the tank 6 , How out 1 schematically is the tank 6 above the injection module 2 arranged. As a result, the fuel passes through the fuel supply line 6a due to gravity to the injection module 2 , The injection module 2 is shown very schematically and includes a fuel pump, a pressure regulator, an injector and an air actuator, so that the injection module 2 very compact.

The small engine 1 further includes a throttle valve 7 which is in a suction tube 8th is arranged. At the cylinder 3 are also a spark plug 9 , an inlet valve 10 and an exhaust valve 11 arranged. The reference number 12 refers to a bypass line for air, which air from the intake manifold 8th from an area in the flow direction of the air in front of the throttle valve 7 branches off and directly to the injection module 2 integrated air actuator leads. An outlet of the bypass line 12 lies directly adjacent to the injector of the injection module 2 ,

The small engine 1 further includes an exhaust pipe 13 passing through the outlet valve 11 is released or closed. Further, an oxygen sensor 14 at the exhaust pipe 13 provided, which with the control unit 5 connected, and the control unit 5 is also with a cooling water sensor 15 , an oil temperature sensor 16 and a sensor unit 17 for detecting a throttle position, a temperature in the intake manifold 8th and a pressure in the intake manifold 8th connected. The control unit 5 controls the injection module based on the received signals 2 ,

The injection device according to the invention is thus an injection module 2 provided with a fuel pump, a pressure regulator, an injector and an air actuator, and can be designed to be particularly compact and compact. Furthermore, the injection device according to the invention can be produced very inexpensively and in particular be pre-assembled in advance as a complete injection module, so that it only in the small engine 1 must be installed as a compact assembly. The integration of the four items fuel pump, pressure regulator, injector and air actuator thus a simple and inexpensive manufacturability is guaranteed. The fuel pump and the air actuator are actuated by a common actuator. As a result, the injection device according to the invention 2 For example, be used in small engines of two-wheelers or lawn mowers.

2 shows the injection module 2 in detail. In the injection module 2 are the fuel pump 20a , the pressure regulator 20b , the injector 20c and the air actuator 20d integrated. For this purpose, a multi-part housing 25 intended. A common actuator simultaneously actuates the fuel pump 20a and the air plate 20d , The common actuator comprises a coil 21 and an anchor 22 , How out 2 is apparent, is at anchor 22 a closing element 23 of the aeronaut 20d fastened, wherein the closing member 23 on a valve seat 12a a bypass line 12 the bypass line 12 can release or close. The anchor 22 is also with a piston 24 too firmly connected, which in this embodiment, a part of the fuel pump 20a is. The piston 24 is designed as a plunger. The sink 21 When energized, simultaneously activates both the closing element 23 as well as the piston 24 , After elimination of the current supply to the coil 21 represents a return spring 28 the closing member and the piston 24 back in the 2 back home positions shown. In the 2 shown position is a position at the end of a suction stroke of the fuel pump 20a ,

The injection module 2 further comprises the multi-part housing 25 comprising a first housing part 25a , a second housing part 25b , a third housing part 25c and a fourth housing part 25d , The first housing part 25a is the air actuator 20d assigned and represents the valve seat 12a of the aeronaut 20d ready. Furthermore, the first housing part 25a nor the function of a guide element for the anchor 22 , The second housing part 25b covers the coil 21 from. The third housing part 25c serves to accommodate the coil 21 and the fourth housing part 25d serves as a guide element for the piston 24 and puts a pumping chamber 27 ready. In the fourth housing part 25d are also connections for the fuel supply 6a as well as for a fuel return line 6b arranged. The fuel supply line 6a flows into the pumping chamber 27 and the fuel return line 6b goes from the pumping chamber 27 off. It should be noted that it is also possible that the fuel return line 6b does not lead back to a tank, but with the fuel supply 6a connected is. In the fourth housing part 25d are a first check valve 29 , a second check valve 30 and a third check valve 31 arranged. The first check valve 29 is between the fuel supply line 6a and the pumping chamber 27 arranged. The second check valve 30 is between pumping chamber 27 and a pressure room 41 a pressure-controlled nozzle 40 arranged. The third check valve is between the pumping chamber 27 and the fuel return line 6b arranged. The third check valve 31 forms the pressure regulator 20b to one in the third pumping chamber if necessary 27 reduce excess pressure. The second check valve 30 is further designed such that from a predetermined pressure in the pumping chamber 27 opens, leaving fuel in the pressure chamber 41 can flow.

As in particular from the 2 and 3 can be seen, includes the injector 20c next to the second check valve 30 also a pressure controlled nozzle 40 , The pressure-controlled nozzle 40 is in detail in 3 shown. The pressure-controlled nozzle 40 includes a nozzle body 44 in which an inlet bore 45 is arranged. The inlet bore 45 makes a connection between the second check valve 30 and the pressure room 41 ready. The pressure room 41 is annular at the end of the pressure-controlled nozzle 40 arranged. At the nozzle body 44 is still a sealing seat 46 formed, which is formed in this embodiment as a ring. Furthermore, the pressure-controlled nozzle comprises 40 a membrane 42 , in which several spray holes 43 are formed. The membrane 42 is by laser welding on the nozzle body 44 attached. How out 3 it can be seen, the membrane has 42 in the attached state, a hemispherical or shell-like shape.

This is the inside of the membrane 42 at the seal seat 46 at. This will be between the membrane 42 and the interior of the seal seat 46 a spray room 47 educated.

The function of the injection module according to the invention 2 is as follows. A suction phase of the fuel pump 20a is through the reset element 28 initiated, wherein the rest position of the return element 28 defines the end of the intake phase. During the intake phase is the first check valve 29 opened and the second and third check valve 30 . 31 are each closed. This allows fuel through the open first check valve 29 into the pumping chamber 27 stream. Subsequently, a current is applied to the coil 21 so that the anchor 22 in the direction of the arrow A is moved to that in the pumping chamber 27 located fluid by means of the piston 24 to put pressure on. This closes the first check valve 29 and while still a low pressure level in the pumping chamber 27 prevails, remain the second and the third check valve 30 . 31 also closed. From a predetermined pressure level then opens the second check valve 30 so that pressurized fluid enters the injector 20c can flow and over the inlet hole 45 in the pressure room 41 flows. Because the membrane 42 is made of an elastic material, as soon as the pressure in the pressure chamber 41 exceeds a predetermined pressure level, the membrane 42 deformed, leaving the membrane 42 from the seal seat 46 takes off. This is in 3 through the dashed membrane 42 ' shown. This allows fuel through the spray holes 43 in the suction pipe 8th be injected. 3 schematically shows a spray 48 , which from the spray holes 43 is injected. Should be a pressure in the pumping chamber 27 Too large, ie greater than a reference value, opens the third check valve 31 to reduce such pressure spikes in the fuel return line. Thus, the third check valve takes over 31 the function of the pressure regulator 20b , Simultaneously with the operation of the fuel pump 20a is when energizing the coil 21 also the closing element 23 of the aeronaut 20d from the seat 12a lifted. This opens the air actuator 20d , allowing air through the bypass line 12 can flow.

When the injection is to be finished, the energization of the coil 21 finished, leaving the anchor 22 through the return element 28 back in the 2 shown initial position is reset. This is the piston 24 from the pumping chamber 27 pulled out, leaving a pressure level in the pumping chamber 27 is reduced. This closes the second check valve 30 , so that too the pressure in the pressure room 41 is reduced. This can cause the membrane 42 again automatically return to their original position and is located on the annular sealing seat 46 at. This completes the injection. By the return movement of the piston 24 begins again the suction phase, in which the first check valve 29 is opened and fuel through the fuel supply line 6a is sucked. In order to prevent contamination, in particular of the check valves and the pressure-controlled nozzle, is also a filter 33 in the Fuel supply arranged. At the same time, by the provision of the anchor 22 also the air actuator 20d closed again by the pressure-controlled nozzle 40 points the injector 20c thus a very simple and low-wear construction. The injection of fuel via a pressure control, so that no complex electronic control o. Ä. Is necessary. The injection can be realized simply by energizing or not energizing the armature. As a result, in particular expensive, outwardly opening nozzles can be dispensed with.

Thus, according to the invention, the injection module 2 a common actuator for the fuel pump 20a and the air plate 20d on. This is merely a coil and a single electric power amplifier with wiring in the fuel pump 20a and the air plate 20d necessary. Furthermore, the air actuator 20d in the operating states of the small motor 1 , in which it is needed, ie, usually at idle, open and close and in operating conditions in which it is not absolutely necessary, it can be ensured that despite the common actuator with the fuel pump 20a an actuation of the fuel pump 20a not delayed or otherwise obstructed.

It should be noted that the injection device is very compact and inexpensive and the injection module 2 each as an integral part of a fuel pump 20a , a pressure regulator 20b , an injector 20c with pressure-controlled nozzle 40 and an air plate 20d includes. Here, in particular, a common actuator for the air actuator 20d and the fuel pump 20a with an anchor 22 intended. In the embodiment, in each case a magnetic actuator was described by energizing a coil as an actuator. It should be noted, however, that in principle other possible actuators can be used, for. B. a piezoelectric actuator.

The following is with reference to 4 an injection device according to a second embodiment of the invention described in detail. Equal or functionally identical parts are denoted by the same reference numerals as in the first embodiment. The injection device of the second embodiment has the difference from the first embodiment only a modified pressure-controlled nozzle 40 on. How out 4 is apparent, is on an inner side of the membrane 42 a closing body 49 arranged. The closing body 49 is, for example, stuck to the membrane by gluing 42 connected. The closing body 49 closes a connection between the pressure chamber 41 and the spray room 42 at a sealing seat 46 , The seal seat 46 is again annular and formed on the nozzle body 44 educated. The sealing seat is formed by an annular flat surface, which is connected to the closing body 49 is in contact to the connection between the pressure room 41 and the spray room 47 to close. If, as described in the first embodiment, a pressure increase in the pressure chamber 41 takes place, from a predetermined pressure, a deformation of the membrane 42 executed, so that the closing body 49 from the seal seat 46 takes off. This creates a connection between the pressure chamber 41 and the spray room 47 open, leaving fuel over the spray holes 43 in the suction pipe 8th can be injected. A return of the membrane 42 takes place as in the first embodiment by a pressure reduction in the pressure chamber 41 , How out 4 it can be seen, the membrane 42 of the second embodiment further formed flat, so that the membrane in particular free of stress on the nozzle body 44 can be fixed. Otherwise, this embodiment corresponds to the first embodiment, so that reference can be made to the description given there.

5 shows a pressure-controlled nozzle 40 according to a third embodiment of an injection device of the invention. The pressure-controlled nozzle 40 of the third embodiment corresponds substantially to that of the second embodiment, in contrast to the sealing seat 46 on the nozzle body by a tapered, in particular conical, area 46a is formed. In a similar manner is the closing body 49 a sealing surface 49a formed in a cone shape. Otherwise, this embodiment corresponds to the second embodiment, so that reference can be made to the description given there.

6 shows an injection device with a pressure-controlled nozzle 40 according to a fourth embodiment of the present invention. Equal or functionally identical parts are denoted by the same reference numerals as in the preceding embodiments.

In contrast to the previous embodiments, the pressure-controlled nozzle comprises 40 of the fourth embodiment additionally a valve body 50 , The seal seat 46 is conical and has a passage opening 46a at an upper end of the cone, which by means of a membrane 42 is closable. At the back of the membrane 42 is also a spring 51 arranged, which is against the valve body 50 supported. Next is on the valve body 50 a stroke stop 52 educated. The function of the pressure-controlled nozzle of the fourth embodiment is as follows. Once in the pressure room 41 an increase in pressure takes place, the membrane 42 against the spring force of the spring 51 from the seal seat 46 lifted. This can Fuel in the spray room 47 arrive and from there through injection holes 43 which is in a perforated disk 53 are arranged, are hosed. The stroke stop 52 limits a path of the membrane 42 , As soon as the pressure in the pressure room 41 is reduced again, as described above, represents the spring 51 the membrane 42 back to the starting position. This is the membrane 42 again at the sealing seat 46 and the injection is finished. The nozzle body 44 and the valve body 50 can be connected by welding, for example.

The following is with reference to 7 an injection device with a pressure-controlled nozzle according to a fifth embodiment of the invention described in detail. Identical or functionally identical parts are again denoted by the same reference numerals as in the previous embodiments.

How out 7 can be seen, includes the pressure-controlled nozzle 40 of the fifth embodiment, in contrast to the previous embodiments, a membrane 42 , which firmly with a designed as a ball closure body 49 connected is. The membrane 42 has a circular hole in which a partial section of the ball is arranged. The closing body 49 is on the membrane 42 attached by gluing or laser welding. The membrane 42 itself is on a nozzle body 44 fixed by laser welding. The closing body 49 is in the closed state at one on the nozzle body 44 formed sealing seat 46 at. The seal seat 46 downstream of the flow direction is a bore opening 56 , which with a perforated disc 53 is covered. In the perforated disc 53 are several spray holes 43 provided, from which a spray 48 with the nozzle open. If the pressure-controlled nozzle 40 pressurized fuel through the inlet bore 45 in the pressure room 41 is fed, starting from a predetermined pressure level, a deformation of the membrane 42 , wherein at the same time also the closing body 49 from the seal seat 46 takes off. In 7 is the deformed membrane by the reference numeral 42 ' and the lifted closing body 49 with the reference numerals 49 ' characterized. This will create a connection between the pressure chamber 41 and the hole opening 56 released, leaving fuel through the spray holes 43 can flow to the outside. As soon as the pressure in the pressure room 41 again sinks, puts the diaphragm 42 itself due to their inherent elasticity back to the starting position, the closing body 49 again at the sealing seat 46 is present and closes this. This completes the injection. The provision of the perforated disc 53 has the further advantage that the pressure-controlled nozzle may have a basic structure for various applications, whereby by simply replacing the perforated disc 53 different sprays can be produced for different purposes. As a result, the production costs for the pressure-controlled nozzle can be kept very low. Otherwise, this embodiment corresponds to the previous embodiments, so that reference can be made to the description given there.

The following is with reference to 8th a pressure controlled nozzle 40 according to a sixth embodiment of the invention described in detail. Equal or functionally identical parts are denoted by the same reference numerals as in the previous embodiments.

The pressure-controlled nozzle 40 of the sixth embodiment corresponds to the essential of the fifth embodiment, in addition to a return spring 51 and a stroke 52 are provided. The stroke stop 52 limits an opening degree of the nozzle, since at a pressure increase of the closing body 49 against the stroke stop 52 strikes and thus another open at the sealing seat 46 is no longer possible. By providing the return spring 51 can the membrane 42 Furthermore, be provided very inexpensively, since the membrane 42 does not have to apply its own restoring forces and thus can be made from a cost-effective material. The stroke stop 52 is on an additional part 44a of the nozzle body 44 attached. A room 54 in which the stroke stop 52 and the return spring 51 are classified, is preferably filled with a compressible medium air. Otherwise, this embodiment corresponds to the previous embodiments, so that reference may be made to the description given there.

Furthermore, the membrane comprises 42 two concentric waves 42a , which are arranged concentrically around a center of the membrane. By providing the concentric waves 42a the membrane softens and can thereby provide a faster response to pressure changes 9 a pressure-controlled nozzle according to a seventh embodiment of the invention described in detail. Equal or functionally identical parts are denoted by the same reference numerals as in the preceding embodiments.

How out 9 can be seen, the seventh embodiment substantially corresponds to the sixth embodiment. In contrast to the sixth embodiment, however, in the seventh embodiment, the attachment of the membrane 42 on the nozzle body 44 differently designed. How out 9 it can be seen, the membrane 42 with egg an o-ring 55 connected at its outer periphery. The O-ring 55 is in an annular groove 44b in the nozzle body 44 arranged. How out 9 it can be seen, the O-ring 55 a lateral radial clearance S1 inward and a lateral radial clearance S2 outward. This has the advantage that the membrane 42 and thereby also the closing body 49 , which is fixed to the membrane 42 connected, can center itself. As a result, the tolerance requirements for the items are slightly lower, so that a more cost-effective production is possible. Otherwise, this embodiment corresponds to the previous embodiment, so that reference can be made to the description given there.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - EP 1340906 B1 [0003]

Claims (12)

Injection device comprising a fuel pump ( 20a ), a pressure regulator ( 20b ), an injector ( 20c ) and an air plate ( 20d ), characterized in that the fuel pump ( 20a ), the pressure regulator ( 20b ), the injector ( 20c ) and the air actuator ( 20d ) integral part of an injection module ( 2 ), and the injector ( 20c ) a pressure-controlled nozzle ( 40 ) with a pressure chamber ( 41 ), a nozzle body ( 44 ) and a membrane ( 42 ). Injection device according to claim 1, characterized in that the nozzle body ( 44 ) a sealing seat ( 46 ), on which the membrane ( 42 ) and the membrane ( 42 ) at least one injection hole ( 43 ), wherein between the membrane ( 42 ) and the nozzle body ( 44 ) a spray room ( 47 ) is arranged and the at least one injection hole ( 43 ) of the membrane ( 42 ) in the area of the injection chamber ( 47 ) is arranged. Injection device according to claim 2, further comprising a closing body ( 49 ), which at one to the pressure chamber ( 41 ) directed side of the membrane ( 42 ) is arranged. Injection device according to claim 2 or 3, characterized in that the sealing seat ( 46 ) is annular. Injection device according to one of the preceding claims, characterized in that the membrane ( 42 ) on the nozzle body ( 44 ) is fixed. Injection device according to claim 1, characterized in that the membrane ( 42 ) with a closing body ( 49 ) is connected and the closing body ( 49 ) at a sealing seat ( 46 ), which on the nozzle body ( 44 ) is formed, is applied. Injection device according to one of the preceding claims, further comprising a return element ( 51 ) to the membrane ( 42 ) to return to a starting position. Injection device according to one of claims 1 to 6, characterized in that the membrane ( 42 ) has an intrinsic elasticity to automatically return to a starting position. Injection device according to one of the preceding claims, further comprising a stop ( 52 ) to limit a stroke during an injection. Injection device according to one of claims 6 to 9, characterized in that the membrane ( 42 ) with a sealing ring ( 55 ), wherein the sealing ring ( 55 ) with a radial clearance in an annular groove ( 44b ) of the nozzle body ( 44 ) is arranged to self-center the membrane ( 42 ). Injection device according to one of the preceding claims, characterized in that the membrane ( 42 ) has at least one concentric shaft. Internal combustion engine comprising exactly one or exactly two cylinders and an injection device according to one of the preceding Claims.