WO2009098112A1

WO2009098112A1 - Compact injection device with reduced tendency to form vapor bubbles

Info

Publication number: WO2009098112A1
Application number: PCT/EP2009/050411
Authority: WO
Inventors: Guenther Hohl; Udo Sieber; Walter Maeurer; Harald Lang
Original assignee: Robert Bosch Gmbh
Priority date: 2008-02-04
Filing date: 2009-01-15
Publication date: 2009-08-13
Also published as: TW200944653A; CN101970851A; DE102008007349A1; CN101970851B; TWI445884B; DE102008007349B4

Abstract

The present invention relates to an injection device comprising a fuel pump (20a), a pressure regulator (20b), an injector (20c) and an air adjuster (20d), characterized in that the fuel pump (20a), the injector (20c) and the air adjuster (20d) are integral components of an injection module (2), the pressure regulator (20b) is an integral component of the injector (20c) and the injection device comprises an intake chamber (30) which is an integral component of the injection module (2) and which is connected to a pump chamber (31) of the fuel pump by way of a first check valve (33), wherein a volume of the pump chamber (31) is smaller than a volume of the intake chamber (30) and wherein the intake chamber (30) comprises a gas-filled area (30a) and a fuel area (30b) for damping an intake pulsation in the intake chamber (30).

Description

description

title

Compact injection device with reduced steam bubble inclination

State of the art

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

Injectors are known in the prior art in various configurations. Especially for cost and space reasons require small internal combustion engines, which have only one or only two cylinders and a small displacement, independent solutions.

Areas of use of such small internal combustion engines are, for example, two-wheelers or tricycles or lawnmowers, etc. Known injectors usually comprise in a tank a fuel pump with a pressure regulator, the fuel pump injecting fuel at a predetermined pressure into a duct, e.g. a rail o.a., promotes. At the end of the line, an injector is arranged, which, controlled by a control device, injects fuel into a suction pipe or directly into a combustion chamber. However, such injectors are very expensive and especially expensive, so that they also make small internal combustion engines very expensive.

From EP 1 340 906 B1 a fuel injection device with electronic control is known in which an injector is arranged close to 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 injection device according to the invention with the features of claim 1 has the advantage that it has a very compact structure. Furthermore, the injection device according to the invention can be produced in a particularly simple and cost-effective manner. Furthermore, according to the invention, a suction pulsation of the pump can be reduced and in particular the generation of vapor bubbles in the fuel supply line can be avoided. This allows the Injection device according to the invention in particular in small internal combustion engines, for example in two-wheelers or lawn mowers or the like may be used. This is inventively achieved in that the injection device comprises a fuel pump, a pressure regulator for controlling an injection pressure, an injector and an air actuator, which are integral components of an injection module. The injection module is a compact, small-sized component. The pressure regulator is an integral part of the injector. Furthermore, the injection device comprises a suction space, which is an integral part of the injection module. The suction chamber is connected via a first check valve to a pump chamber of the fuel pump. A volume of the pumping space is smaller, preferably many times smaller, than a volume of the intake space. Particularly preferably, the volume of the pumping space is smaller by a factor of 10 or more than the volume of the suction space. A gas-filled area and a fuel area containing liquid fuel are provided in the intake space. The gas-filled area assumes the task of damping an intake pulsation of the fuel pump in the intake chamber. Furthermore, any vapor bubbles present in the fuel supply line rise to the gas-filled region of the intake space, since the intake space between an opening of the fuel supply line and the

Fuel pump is arranged. The injection module can be completely pre-assembled so that it only needs to be connected to the necessary connections and can be installed directly into a vehicle. The components of the injection module are preferably arranged in a common housing of the injection module. In addition to the compactness of the injection module is another great advantage that other components for the injection module can be minimized.

The dependent claims show preferred developments of the invention.

Preferably, the injection device further comprises a return space, which is connected via a second check valve with the pump space. The return space preferably has a volume which is larger, preferably 10 times larger than the volume of the pump space. The return space takes on the task that, if vapor bubbles have formed in the pump chamber or vapor bubbles were sucked into the pump chamber, they can be removed via the second check valve in the return space, especially at the beginning of the pressure phase in the fuel pump. Here, one end of a piston of the fuel pump forms a control edge, which closes a connection of the second check valve in the further course of the movement of the piston to build up pressure in the pump chamber. Thus, the actual pressure build-up phase in the pumping chamber begins somewhat delayed.

Particularly preferably, the return space also comprises a gas-filled area. This can be achieved by providing two gas-filled areas, once in the return space and once in the suction, a further reduction of Saugpulsation the fuel pump. As a result, if vapor bubbles have been delivered into the recirculation space, they can accumulate in the gas filled area of the recirculation space.

Preferably, the return space is hydraulically connected to the suction space. Particularly preferably, the return space and the suction space is provided as a common, annular space. As a result, a particularly simple construction is made possible and the common space has two gas-filled areas, one at the return area and one at the intake area.

More preferably, the return space is connected to a tank. This may allow the vapor bubbles separated from the pumping chamber to be fed back into the tank. In order to maintain a gas-filled area in the return space, a connection of the tank is preferably arranged slightly below a vertically located uppermost region of the return space.

According to an alternative embodiment of the present invention, the return space is connected to the air actuator. As a result, vapor bubbles, which were conveyed into the return space, are guided via the bypass air line to the intake manifold. Since the air actuator and the fuel pump or the injector are actuated simultaneously during each injection process, the fuel vapor accumulated in the return chamber passes via the air actuator into the intake manifold so that an amount of fuel injected into the intake manifold via the injector can be reduced.

In order to prevent liquid fuel from entering the aerator via the connecting line between the return chamber and the aerator, a float valve is preferably arranged in the connecting line. The float valve includes a float that floats on top of the fuel. The float is guided with play in the connecting line and can seal the line to a floating valve seat. As a float, for example, a ball or a float with a separate sealing element can be used.

Preferably, a discharge line from the air actuator opens in the intake manifold at a location which lies in the flow direction in the intake manifold in front of a sealing throttle. This prevents the fuel from escaping from the return space via the connecting line to the air actuator and from there via the intake manifold to the engine into the environment when the engine is stopped.

More preferably, the connecting line between the return chamber and the air actuator opens into a region of the air actuator such that an opening of the connecting line is released or closed by a closing member of the air actuator. Thus, the closing member of the - A -

Luftstellers in addition to the release and closing of the Luftstellers nor the function of releasing and closing the connecting line. This will prevent fuel from evaporating into the environment if the throttle is not completely sealed.

Particularly preferably, the mouth of the connecting line is parallel to an air supply to the air actuator. In this way, a simple and cost-effective design of the air regulator can be achieved and the connecting line and the air plate can be opened and closed simultaneously. Alternatively, the mouth of the connecting line opens at an angle of 90 ° to the air supply line of the Luftstellers. This can be achieved in a simple manner a time-varying opening and closing of the mouth and the Luftstellers.

More preferably, an inlet from the tank to the suction chamber and the first check valve between the suction chamber and the pump chamber are arranged at positions offset from one another in the axial direction of the injection device. This prevents that possibly occurring pressure waves, which are transmitted from the fuel supply, can not propagate directly through the opened first check valve in the pump chamber. Furthermore, it can be prevented that possibly supplied from the fuel supply steam bubbles are not directly sucked by the pump, but have the ability to ascend previously in the suction in the direction of the gaseous region in the suction. The staggered arrangement is chosen in particular such that the first check valve in the horizontal direction of the injection device is arranged lower than the mouth of the fuel supply line in the suction.

The injection device preferably comprises exactly one actuator, which simultaneously actuates the fuel pump and the aerator. As a result, in each case a separate actuator for the aerator or the fuel pump can be omitted in each case, so that the number of components is significantly reduced. Of course, this also results in a cost reduction. Thus, the common actuator assumes first the function of the pump drive and secondly the function of the actuator for the air actuator. The common actuator may perform a simultaneous actuation of the fuel pump and the air actuator, wherein the actuator comprises a coil, a first armature and a second armature. Here, the first armature is assigned to the air actuator and the second armature of the fuel pump, and both anchors can be activated by means of the common coil. Alternatively, the air actuator can also be operated independently of the fuel pump.

The pressure regulator integrated into the injector preferably comprises an outwardly opening valve element and a spring element biasing the valve element in order to regulate the injection pressure. In other words, the injector is provided as an outwardly opening injector, which opens upon application of a predetermined pressure, wherein the spring force of the spring element overcome becomes. An injection is terminated as soon as a pressure applied to the injector drops below the actuating pressure, so that the outwardly opening valve element is returned to the starting position by the spring element.

In order to provide as compact a structure as possible, the first armature is preferably a part of the air regulator and the second armature is a part of the fuel pump. In particular, the first armature is a valve member of the air regulator and the second armature is a piston of the fuel pump.

Furthermore, the present invention relates to an internal combustion engine which comprises exactly one cylinder or exactly two cylinders and a fuel injection device according to the invention. Particularly preferably, the internal combustion engine comprises a fuel tank, which is arranged above the injection module. As a result, a negative pressure and thus the gas bubble formation during suction can be reduced.

drawing

Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:

Figure 1 is a schematic view of a small motor with an injection device according to a first embodiment of the invention, Figure 2 is a schematic view of the injection device according to the first

Embodiment,

FIG. 3 shows a schematic view of the injection device according to a second exemplary embodiment,

Figure 4 is a schematic view of the injection device according to a third

Embodiment, Figure 5 is a schematic view of the injection device according to a fourth

Embodiment, and Figure 6 is a schematic view of the injection device according to a fifth embodiment. Preferred embodiments of the invention

Hereinafter, a small motor 1 with an injection device according to the invention according to a first embodiment will be described in detail with reference to Figures 1 to 4.

Figure 1 shows schematically the structure of the small motor 1, which is designed as a single-cylinder engine. The small engine 1 comprises a cylinder 3, a reciprocating piston 4, a control unit 5 and a tank 6. The tank 6 is connected to an injection module 2 via a fuel supply line 6a. A fuel return line 6b goes from the injection module 2 back to the tank 6. As can be seen schematically from FIG. 1, the tank 6 is arranged above the injection module 2. 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, an injector with integrated pressure regulator, and an air actuator, so that the injection module 2 is very compact.

The small engine 1 further comprises a throttle valve 7, which is arranged in a suction pipe 8. On the cylinder 3, a spark plug 9, an intake valve 10 and an exhaust valve 11 are further arranged. The reference numeral 12 designates a bypass line for air, which branches off air from the intake manifold 8 from a region in the flow direction of the air in front of the throttle valve 7 and leads directly to the integrated into the injection module 2 air actuator. An outlet 12z of the bypass line 12 opens in the intake manifold 8 behind the throttle valve. 7

The small engine 1 further comprises an exhaust pipe 13, which is released or closed by the exhaust valve 11. Further, an oxygen sensor 14 is provided on the exhaust pipe 13, which is connected to the control unit 5, and the control unit 5 is further provided 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 8 and a pressure in the intake manifold 8 are connected. The control unit 5 controls the injection module 2 on the basis of the received signals.

The injection device according to the invention is thus provided as an injection module 2 with a fuel pump, a pressure regulator, an injector and an air actuator, and can be designed to be particularly compact and physically small. 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 needs to be installed in the small engine 1 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. Thereby For example, the injection device 2 according to the invention can be used in small motors of two-wheelers or lawn mowers.

FIG. 2 shows the injection module 2 in detail. In the injection module 2, the fuel pump 20a, the pressure regulator 20b, the injector 20c and the aerator 2Od are integrated. For this purpose, a multi-part housing 25 (shown only schematically in FIG. 2) is provided. The pressure regulator 20b is part of the injector 20c. A common actuator simultaneously actuates the fuel pump 20a and the aerator 2Od. The common actuator comprises a coil 21, a first armature 22 and a second armature 23. As can be seen in FIG. 2, the first armature 22 is part of the air actuator 2Od, the armature 22 having at one end a valve member 22a which on a valve seat 12a of the bypass line 12, the bypass line 12 can release or close. The aerator 2Od is further associated with a first return spring 28. The actuator further includes a second armature 23, which in this embodiment is a part of the fuel pump 20a. Here, the second armature 23 is axially connected to a piston 26 of the fuel pump 20a. The second armature 23 is a cylindrical component and is in

Inside the coil 21 guided by a guide member 19. The guide element 19 has, in addition to a guide function, also a support function for the first return spring 28. Reference numeral 29 denotes a non-magnetic element to interrupt the iron circle of the coil 21. The coil 21 actuates, when energized, both the first armature 22 and the second armature 23. After elimination of the energization of the coil 21 are the first

Return spring 28 and a second return spring 24 for the second armature the two anchors back to the initial positions shown in Figure 2 back. The second return spring is supported on a housing block 25a and an end face of the second armature 23.

As can be seen from Figure 2, the fuel supply line 6a and the housing 25 are on

Fuel return line 6b arranged. The fuel supply line 6a discharges into an intake space 30. The fuel return line 6b starts from a return space 32. The volume of the suction space 30 and the return space 32 are hydraulically connected to each other. In the housing block 25a, a pumping space 31 is further formed. The pump chamber 31 is connected via bores to the suction chamber 30, the return chamber 32 and the injector 20c, more precisely a pressure chamber 42 of the injector 20c. Here, a first check valve 33 is disposed between the suction chamber 30 and the pump chamber 32, between the pump chamber 31 and the pressure chamber 42, a second check valve 34, and between the pump chamber 31 and the return chamber 32, a third check valve 35, respectively. The pump chamber 31 is part of the fuel pump 20b. As can be seen from FIG. 2, a piston 26 of the fuel pump is arranged in the housing block 25a in such a way that it can pressurize a fluid located in the pumping space 31. The piston 26 is axially connected to the second armature 23. The position shown in Figure 2 is a position at the end an intake stroke of the fuel pump 20a. The pump chamber 31, the first armature 22 and the second armature 23 lie on a common axis XX.

As is apparent from FIG. 2, the third check valve 35 is arranged in the axial direction X-X of the injection module 2 at a position closer to the coil 21 than the first check valve 33.

The third check valve 35 serves at the beginning of the pressure phase to the fact that any existing gas bubbles can be conveyed from the pump chamber 31 in the return chamber 32. The end of the piston 26 forms a control edge 26a, which closes the connection for the third check valve 35 in the further course of the movement of the piston 26, so that then the actual pressure build-up phase for the fuel located in the pump chamber 31 begins. The second check valve 34 is further designed such that it opens from a slight overpressure in the pump chamber 31, so that fuel can flow into the pressure chamber 42 of the injector 20c. The injector 20c, which also includes the pressure regulator 20b for regulating the injection pressure, then opens from a predetermined pressure in the pressure chamber 42 against the force of a spring element 41, wherein the valve element 40 is an outwardly opening valve element. The injector 20c injects fuel into the intake manifold 8.

As shown in FIG. 3, the suction space 30 has a gas-filled region 30a at its end lying in the vertical direction. This gas-filled area 30a serves as

Damping pads to dampen pressure waves, which are returned from the fuel supply line 6a to the suction chamber 30. Reference numeral 30b denotes a region of the intake pipe filled with liquid fuel. Further, as shown in Fig. 2, an orifice of the fuel supply pipe 6a is arranged in the suction space 30 at a position closer to the spool 21 than the first check valve 33 in the vertical direction

Pressure waves or vapor bubbles from the fuel supply line 6a are forwarded directly into the pump chamber 31 and be sucked. Steam bubbles from the fuel supply line can easily outgas, and pressure waves are thrown back from the housing block 25a first and then mitgedämpft over the gaseous region 30a.

Similarly, a gas filled area 32a is provided in the return space 32. In this embodiment, the return chamber 32 and the suction chamber 30 form a common, substantially annular space, in the middle of the housing block 25a and the coil 21 is arranged. One half of this common space forms the suction chamber 30 and the other half the return space 32. The common volume of the suction and the return space 32 is a multiple of the volume of the pump chamber 31, for example, ten times the total volume. The fuel return line 6b is, as can be seen from FIG. 2, not on arranged at the top end of the return space 32, but slightly below, to prevent the gaseous cushioning pad in the return chamber 32 is passed directly back into the tank.

The function of the injection module 2 according to the invention is as follows. An intake phase of the fuel pump 20a is introduced through the second return element 24, wherein the rest position of the second return element 24 defines the end of the intake phase. During the suction phase, the first check valve 33 is opened and the second and third check valves 34, 35 are each closed. As a result, fuel can flow into the pump chamber 31 via the open first check valve 33. Subsequently, the coil 21 is energized, so that the second armature 23 is moved in the direction of the arrow A, in order to pressurize the fluid located in the pumping space 31. This closes the first check valve 33 and as long as there is still a low pressure level in the pump chamber 31, the second check valve 34 also remains closed. At the beginning of the pressure phase, the third check valve 35 is opened in order to push out any gases present in the pump chamber 31 into the return chamber 32. As soon as the control edge 26a of the piston 26 has completely closed the connection for the third check valve 35, a pressure buildup in the pump chamber 31 begins. From a predetermined pressure level, the second check valve 34 opens, so that the pressurized fluid enters the pressure chamber 42 of the injector 20c can flow and is injected from there from a certain pressure level independently. When the fuel pump 20a is actuated, the first armature 22 of the air regulator 2Od is also attracted in the direction of the arrow B when the coil 21 is energized. As a result, the air actuator opens 2Od, so that air can flow through the bypass line 12. As a result, air can flow to the suction pipe 8 via the outlet 12z.

After injection, the energization of the coil 21 is terminated, so that the return springs 24 and 28, the first and second armature 22, 23 back to their original positions. As a result, the aerator 2Od is closed again and during the return of the second armature 23, the piston 26 is pulled back so that the suction phase begins again. It should be noted that the restoring forces of the return springs 24 and 28 are designed such that, with only a small current to the coil 21, the air actuator 2Od can also be operated separately without actuating the fuel pump.

As described above, a suction pulsation of the fuel pump 20a is now damped by the gaseous region 30a, which acts like a damping pad in the suction space 30. Furthermore, a disturbing fuel vapor in the supply line resulting from the cyclical suction of the fuel pump 20a can also be prevented from penetrating into the pumping space 31. If vapor bubbles occur in the fuel supply line 6a, they can escape upwards in the intake space 30 due to the large volume of the intake space 30 and are thus not sucked in by the fuel pump 20a. Furthermore, since a steam cushion 32a is also provided in the return space 32, a result is obtained Storage effect in the return space 32, so that a negative pressure formation and a Pulsationsausbreitung is reduced in the fuel supply. Thus, the tendency for vapor bubble formation is reduced. The fuel volume in the return space 32 also further reduces the tendency for vapor bubbles to form in the pumping space 31.

Thus, according to the invention, a compact injection device can be provided in which a risk of the formation of vapor bubbles is reduced and in particular can be avoided that vapor bubbles are injected via the injector 20c in the intake manifold 8 and thereby the amount of fuel injected by the injection of vapor bubbles is wrong ,

Furthermore, the injection module 2 has a common actuator for the fuel pump 20a and the aerator 2Od. As a result, only one coil and a single electric power amplifier with wiring in the fuel pump 20a and the aerator 2Od is necessary. Furthermore, in the operating states of the small engine 1 in which it is required, ie usually idle, the aerator 2Od can open and close and in operating states in which it is not absolutely required, it can be ensured that despite the common actuator with the Fuel pump 20 a actuation of the fuel pump 20 a is not delayed or otherwise hindered. In the embodiment, a magnetic actuator by energizing a coil has been described as an actuator. It should be noted, however, that in principle other possible actuators may be used, e.g. a piezoactuator. It should also be noted that the described closure element 22a of the air actuator 2Od can also be designed as a tapering, in particular conical, end region of the armature 22, or in any other way, for example as a sphere or part sphere.

Hereinafter, an injection device 1 according to a second embodiment of the invention will be described in detail with reference to FIG. Identical or functionally identical parts are denoted by the same reference numerals as in the first embodiment.

The second embodiment corresponds essentially to the first embodiment, in contrast to the second embodiment, no fuel return line is provided to the tank. Instead, as shown in FIG. 3, a connecting line 50 is provided between the return space 32 and the aerator 2Od, more precisely a space 12b, in the area of the aerator. Furthermore, a float valve 51 is provided, which is arranged in the connecting line 50. The float valve 51 comprises a float ball 52, which can be pressed by a rising column of liquid against a valve seat 53 in the connecting line 50.

As a result, the connecting line 50 can be closed. The float valve 51 prevents liquid fuel from entering the aerator 2Od and thus blocks the air Connecting line 50 between the return space 32 and the air actuator 2Od. The float ball 52 in this case has such a diameter that it is arranged in the region of the return space 32 below the connecting line 50 with play, so that steam bubbles can be easily passed past the float ball 52.

If there is only a small formation of vapor bubbles, the fuel level in the return chamber 32 increases, so that the float ball 52 closes the valve seat 53. As a result, no fuel vapor passes via the air actuator 2Od to the intake manifold 8, so that the injection module injects fuel only via the injector 20c.

The arrangement of the float valve 51 in the axial direction X-X of the injection module 2 is chosen such that it is ensured that in the suction chamber 30, which is arranged parallel to the return chamber 32, remains over a gaseous volume in the region 30a. As a result, the damping function is maintained in the suction chamber 30.

Since the injection module 2 simultaneously actuates the fuel pump 20a and the aerator 2Od, possibly existing fuel vapor may be required via the connecting line 50 and the outlet 12z of the air regulator 2Od into the intake manifold 8. Thereby, an injection amount of fuel via the injector 20c can be reduced.

Figure 4 shows a section of an alternative embodiment of the float valve 51 according to a third embodiment of the invention. As can be seen from FIG. 4, the float valve 51 is designed as a floating body 54 with a separate sealing element 55. Otherwise, this embodiment corresponds to the second embodiment, so that reference can be made to the description given there.

FIG. 5 shows an injection module 2 according to a fourth exemplary embodiment of the invention. Identical or functionally identical parts are designated by the same reference numerals as in the preceding embodiments.

The fourth exemplary embodiment substantially corresponds to the second exemplary embodiment, wherein, in contrast to the second exemplary embodiment, an opening region of the connecting line 50 to the air distributor 2Od is designed differently. As shown in FIG. 5, an orifice 50a of the communication passage 50 is arranged so as to be parallel to an orifice of the bypass passage 12 for the air of the air actuator 20d. The valve closing member 22a of the air actuator 2Od has an enlarged diameter and simultaneously closes both the connecting line 50 between the return space 32 and the space 12b of the air regulator and the supply line 12 (see. FIG. 5). When the coil 21 is energized, the valve closing member 22a simultaneously opens both the supply line 12 and the connecting line 50. This ensures that fuel vapor can only enter the intake manifold 8 via the air regulator 22d when the air regulator 22d is actuated. An actuation of the Luftstellers 22d takes place only during engine operation, because only then the steam-air mixture is sucked. When engine arrest remains possibly occurring

Fuel vapor therefore in the connecting line 50 and in the return chamber 32, so as to ensure that no outgassing of fuel vapor can occur during engine stall.

Thus, the remaining fuel vapor via the air actuator 2Od is shared and further, a fuel return line to the tank can be omitted. Otherwise, this embodiment corresponds to the previous embodiments, so that reference can be made to the description given there.

FIG. 6 shows an injection module 2 according to a fifth exemplary embodiment of the invention, wherein in turn identical or functionally identical parts are designated by the same reference numerals as in the preceding exemplary embodiments.

The fifth embodiment corresponds substantially to the fourth embodiment, wherein in contrast to an orifice 50a of the connecting line 50 Luftsteller 2Od is different loaned lent. As can be seen from FIG. 6, the connecting line 50 opens relative to the connecting line 50

Air supply line 12 at an angle of 90 ° in the space 12b. Since a diameter of the valve member 22a of the air actuator 2Od is designed to cover the entire area of the space 12b, a side surface 22c of the valve member 22d is responsible for releasing the mouth 50a of the connection pipe 50. Here, a small shoulder for 25b is provided in the housing 25, so that the air supply line 12 and the connecting line 50 are opened with a time delay. A Öffhungsreihenfolge is such that only the air line 12 and then the connecting line 50 is opened. Thus, the valve member 22a on a slide function, so that in a simple manner, a time-delayed opening can be realized. It should be noted that, of course, can be dispensed with the paragraph 25b in the housing and the mouth in the space 12b is arranged such that it is provided directly at the top of the room. As a result, a simultaneous opening of the air supply line 12 and the connecting line 50 can be realized. Otherwise, this embodiment corresponds to the previous embodiment, so that reference can be made to the description given there.

Claims

claims

An injection apparatus comprising a fuel pump (20a), a pressure regulator (20b), an injector (20c) and an aerator (20d), characterized in that the fuel pump (20a), the injector (20c) and the aerator (20d) integral part of an injection module (2), the pressure regulator (20b) is an integral part of the injector (20c), and the injection device comprises a suction chamber (30) which is an integral part of the injection module (2) and which via a first check valve (33 ) is connected to a pumping space (31) of the fuel pump, wherein a volume of the pumping space (31) is smaller than a volume of the suction space (30) and wherein the suction space (30) comprises a gas-filled area (30a) and a fuel area (30b) to dampen suction pulsation in the suction space (30).

2. Injection device according to claim 1, further comprising a return space (32) which is connected via a second check valve (35) with the pump chamber (31).

3. Injection device according to claim 2, characterized in that the return space (32) comprises a gas-filled area (32a).

4. Injection device according to claim 2 or 3, characterized in that the return space (32) is hydraulically connected to the suction space (30).

5. Injection device according to one of claims 2 to 4, characterized in that the return space (32) is connected to the tank via a return line (6b).

6. Injection device according to claim 5, characterized in that the return line (6b) is arranged to the tank below a vertical in the vertical direction of the injector highest portion of the return space (32).

7. Injection device according to one of claims 2 to 4, characterized in that the return space (32) with the air actuator (2Od) is connected.

8. Injection device according to claim 7, characterized in that in a connecting line (50) between the return space (32) and the air plate (2Od), a float valve (51) is arranged.

9. Injection device according to claim 8, characterized in that the connecting line (50) in a region (12b) of the Luftstellers (2Od) opens such that an orifice (50a) of the connecting line (50) by a closing member (22a) of the Luftstellers ( 2Od) is lockable and releasable.

10. Injection device according to claim 9, characterized in that the mouth (50a) of the connecting line (50) at an angle of 90 ° to an air supply line (12) in the air plate (2Od) opens and the valve member (22a) of the Luftstellers (2Od ) opens the mouth of the connecting line (50) offset in time to the air supply line (12) opens and closes.

11. Injection device according to one of the preceding claims, characterized in that a fuel supply line (6a) to the suction chamber (30) and the first check valve (33) between the suction chamber (30) and the pump chamber (31) in the axial direction (XX) of the injection device are arranged to each other.

12. Injection device according to one of the preceding claims, characterized in that a discharge line (12z) of the air regulator (2Od) opens into a suction pipe (8) in the flow direction of the suction pipe in front of a sealing throttle.

13. Injection device according to one of the preceding claims, characterized in that the injection device comprises exactly one actuator which actuates both the fuel pump (20a) and the air actuator (2Od), wherein the actuator comprises a coil (21), a first armature (22 ) and a second anchor (23).

14. Injection device according to one of the preceding claims, characterized in that the pressure regulator (20b) comprises an outwardly opening valve element (40) and a valve element (40) biasing spring element (41) to regulate the injection pressure.

15. Internal combustion engine comprising exactly one or exactly two cylinders and an injection device according to one of the preceding claims.