DE102015014350B4 - Pressurized injector - Google Patents

Abstract

Pressure-actuated injector (1), comprising: - a pressure surge generator, - a slave device (5) with a membrane (7), with which membrane (7) a fuel chamber (9) is divided in the injector (1), wherein the slave device (5) is provided to receive a pressure surge on the part of the surge absorber and to effect a corresponding increase in hydraulic pressure in the fuel chamber (9) under deflection of the diaphragm (7) depending on the intensity of the pressure surge, - wherein the injector (1) further comprises an injection valve (17) on the Fuel chamber (9), which is urged with hydraulic pressure increase in the open position.

Description

The present invention relates to a pressure-operated injector according to claim 1.

Generally fuel injectors are known in different configurations, for. B. from the publications DE 10 2013 021 242 A1 . DE 43 06 072 A1 . EP 0 630 442 B1 or the publication US 4,728,074 A ,

In order to ignite fuel gas mixtures in gasoline engines, spark plugs are usually used, for example, with purged or unsprayed antechamber. These spark plugs are expensive and usually wear out after about 4000 operating hours. As an alternative to the use of spark plugs the Zündstrahlverfahren is known, which provides the application of a Zündölmenge via a particular timed injector to then ignite after the ignition of the fuel gas mixture. As a result, such lean mixtures can be ignited, which would no longer be flammable with the lower energy input of a spark plug.

The problem with such a Zündstrahlverfahren is always the effort to be operated for the injection system, in particular for the timed injector, the high-pressure pump, the at least one cooler and the return system.

Proceeding from this, the object of the present invention is to specify an injector with which the outlay for an ignition oil application-in particular in the context of an ignition-jet process-can advantageously and significantly be reduced.

This object is achieved with a pressure-operated injector with the features of claim 1.

Advantageous developments and embodiments of the invention are specified in the further claims.

The invention proposes a pressure (shock) actuated injector, which is preferably used with a gasoline engine and further in particular with a gas-powered gasoline engine. Preferably, the injector for Zündölausbringung is provided, in particular of small or very small amounts, insofar preferably for a Zündstrahlverfahren, in particular in conjunction with a gasoline engine or fuel gas operation as mentioned above. As ignition oil can z. B. diesel fuel or heavy oil or another ignitable liquid. The injector is advantageously usable with a large engine, for example in a motor vehicle such as a truck, a different commercial vehicle, a ship, a locomotive woneben the injector can also be provided for a stationary device, for. B. for a combined heat and power plant, an (emergency) generator, z. B. also for industrial applications.

The pressure-operated injector comprises a pressure surge generator, in particular in the form of a striking mechanism. By means of the pressure surge generator, a pressure pulse or impact pulse of very short duration can be generated, for example in the range of 1 to 3 ms or even below. In the context of the present invention, the pressure surge generator is in particular also designed to be able to generate pressure surges with different intensity, for example by varying the energy input into an encoder or striking element. With the variation of the energy input, for example, a deflection of the donor element can be influenced, for. B. in view of the deflection amplitude of the same. The pressure surge generator can, for example, have a monopolar or bipolar linear magnet, for example also a piezoelectric package, in order to accelerate or deflect the transmitter or striking element, such as a hammer, directly or indirectly, for example by means of a biasing spring, to produce pressure shock , in particular electric. A compressed air actuation is z. B. conceivable.

The pressure-actuated injector further comprises a slave device with a membrane, with which membrane a fuel chamber is divided in the injector. The membrane is particularly elastic, preferably a rubber or polymer membrane, alternatively, for example, a metallic membrane, for example made of a metal sheet. In general, the slave device is provided to receive a pressure impulse or impact pulse on the part of the pressure surge generator and to effect a corresponding (hydraulic) pressure increase in the fuel chamber under deflection of the membrane as a function of the intensity of the pressure impulse or impact pulse.

The fuel chamber is now provided to receive a (liquid) fuel volume, in particular ignition oil. In this case, the volume of the chamber in the context of the present invention is influenced by the deflection of the membrane, by means of which the fuel chamber in particular undergoes a housing or is defined. The fuel chamber is - in addition to the membrane - further defined or formed in particular by a - rigid - housing of the injector.

The injector further comprises an injection valve, which is formed on the fuel chamber, wherein the thus configured injector is further configured, the injection valve with the Hydraulic pressure increase (in the fuel chamber), and in particular on the hydraulic pressure increase, to urge in the open position, in particular hydraulically and further in particular by means of the recorded fuel in the fuel chamber (ignition oil). In this way, an injector can be provided in which the injection valve selectively opens in response to a hydraulic pressure in the fuel chamber (or when a differential pressure threshold value of hydraulic pressure and combustion chamber-side backpressure is exceeded).

The injector can advantageously extremely low cost and structurally inexpensive, also be made small building, the injector allows the intended small and very small injection quantity reliably and wherein the required injection pressure, i. e. in the present case, a corresponding hydraulic pressure is applied in a simple manner by the impact pulse or the pressure surge, as a result of which the injection valve also opens when an opening pressure threshold value of the injection valve is exceeded.

The injection valve itself can be advantageously formed inexpensively, for. B. have an injection valve seat which cooperates with an injection valve member of the injection valve. The injection valve member is z. B. a valve plate which acts against the injection valve seat, wherein the injection valve seat z. B. a cone (ring) seat is. In order to urge a thus formed injection valve in the open position, thus releasing a flow path from the fuel chamber (through the valve seat) for injection, the injection valve may preferably be provided outwardly opening (toward a combustion chamber), so that the hydraulic pressure (through the Valve seat through) can act in a simple manner against the valve disk, d. H. to remove it from the seat.

For closing the open or in the open position compressed injection valve, the injector preferably has at least one restoring device, which may be formed for example by means of a spring load. The return device is provided to the injection valve member, for. B. also the slave device, due to an unloaded or pressure shock-free starting position.

In a first preferred embodiment of the present invention, the slave device has a piston. The piston can in this case be formed in one or more parts, for example, have an inner part, which is the impact stress receiving made of a relatively harder material, and for example an outer, z. B. cup-shaped, part, which is made of a relatively softer and so far also favorable material. The piston may preferably be guided in a piston guide, which is formed by the fuel chamber or a wall thereof.

By means of the piston can be divided in this embodiment, for example, a first einspritzventilfernerer chamber part in the fuel chamber, which is further defined with the membrane, next to a second, injection valve closer chamber part on which the injection valve is formed. It is noteworthy that in this case the first and the second chamber part - in particular communicate via an overflow connection - in particular with each other, d. H. for fuel filling of the second chamber part, for example via an annular gap around the piston or between piston and piston guide. In this case, a check valve device is preferably arranged in the overflow connection, which can be provided in the context of the invention as an advantageously simple ring seal with the function of a check valve. Furthermore, it can be provided in this case to provide the annular gap as a ring capillary line, via which the second chamber part can be filled with fuel from the first chamber part.

In this embodiment, in particular, the piston is provided for acting on the pressure surge, wherein the piston with the membrane - to a common deflection - in particular also connected, preferably also mitdefiniert the fuel chamber. For example, the piston may be arranged in the middle of the membrane surrounded by this circumferentially, which in this case covers the first, around the piston or an end portion thereof formed around the chamber part elastically. In this embodiment, the piston may extend from the first chamber part and through the piston guide towards the second fuel chamber part, wherein the volume of the second fuel chamber part varies depending on the piston position.

In the course of a Druckstoßbeaufschlagung on the part of the pressure surge, the piston is deflected in the injector thus formed, especially in the direction of the first chamber to the second chamber, which in particular is accompanied by a deflection of the membrane and further hydraulic pressure increase in the second chamber part, d. H. according to the invention to penetrate in the open position (so that fuel from the second chamber part can be applied (injection)). Preferably, then the piston - preferably together with the injection valve member - are displaced by means of a return device provided for this purpose again in the direction of the first chamber part, so that the injection valve closes.

In this embodiment of the injector can be a refilling of the fuel chamber via a guided to the first chamber part line, which also has, for example, a check valve device. Piston guide, first and second chamber part here z. Example, be formed by means of a stepped bore, in particular such that the first chamber part has a largest cross-section, the piston outlet from a second smaller cross-section and the third chamber part ultimately has a third, smallest cross-section (eg., With a funnel-shaped transition from the second Cross-section).

In a further preferred embodiment of the present invention, the membrane is provided in the context of the slave device directly to Druckstoßbeaufschlagung or for acting on the impact pulse. The membrane has in particular a low rigidity in order to counteract the impact impulse with as little resistance as possible. In this embodiment, the injector in particular also has no piston.

Even with such an embodiment of the injector is provided to provide a fuel chamber, which is encapsulated by means of the membrane, and on which the injection valve is formed. If the membrane is subjected to the pressure surge, this causes a hydraulic pressure increase (in the fuel) in the fuel chamber and in the consequence that the injection valve with the hydraulic pressure increase and in particular via the hydraulic pressure increase in the open position is urged or is forced into the open position. For a closing of the injection valve can also be provided here a restoring device, which causes the injection valve member is again guided against the seat. A refilling of the fuel chamber can be provided via a guided to the fuel chamber fuel line, for example, in turn provided with a check valve device or z. B. formed as a capillary.

In connection with such an embodiment, it is further proposed that one or more support elements or stops are associated with the membrane, which counteract overstressing or even avoidance of the membrane in the course of a pressure impingement.

Furthermore, the fuel chamber may be formed in such a structurally advantageous simple embodiment of the injector in a pot-shaped portion of the injector, wherein the membrane spans an inner cross section, for example, thus defining the fuel chamber. Spacer elements can be attached to the edge of the membrane, for example annularly.

Generally, it is also provided in the context of the invention that the pressure-actuated injector has a valve rod which is coupled to the injection valve member of the injection valve. Preferably, the valve rod can also be in operative connection with a restoring device, for. B. be coupled to the piston. About such a valve rod can in the context of the present invention, for. As well as a mechanical opening support of the injector carried out, for example, to the effect that the piston or the membrane are urged at pressure shock loading against the valve stem.

With the invention, a fuel injection system is proposed, which is in particular fair established a Zündstrahlverfahren. In this case, the fuel injection system has at least one pressure-actuated injector as discussed above, in particular for discharging ignition oil as fuel.

Furthermore, the invention also proposes an internal combustion engine, in particular designed for an ignition jet method (preferably with fuel gas and ignition oil) and furthermore provided as a gasoline engine, wherein the internal combustion engine has at least one pressure-operated injector as discussed above or a fuel injection system as discussed above.

Further features and advantages of the invention will become apparent from the following description of embodiments of the invention, with reference to the figures of the drawings, which show details essential to the invention, and from the claims. The individual features may be implemented individually for themselves or for a plurality of different combinations in a variant of the invention.

Preferred embodiments of the invention are explained below with reference to the accompanying drawings. Show it:

1 exemplary and schematically a pressure-operated injector in a broken and partially cut view according to a possible embodiment of the invention.

2 exemplary and schematically a detail of the pressure-operated injector after 1 ,

3 exemplary and schematically a pressure-operated injector in a broken view according to another possible embodiment of the invention.

In the following description and the drawings, the same reference numerals correspond to elements of the same or comparable function.

1 shows an example and schematically a pressure (shock) operated (fuel) injector 1 in a broken, partially cutaway view, with the injector 1 a (not illustrated in detail) pressure surge, which is formed and set up by means of a percussion, by means of a push-button element 3 against a slave device 5 of the injector 1 to act on their impact with a shock pulse or pressure surge. The surge absorber element 3 may be formed, for example, as a firing pin or striker.

As 1 Also illustrated, the slave device 5 a membrane 7 on, with which membrane 7 a fuel chamber 9 in the injector 1 is divided. The membrane 7 is formed as a (flat) annular rubber membrane and on its outer periphery with the peripheral wall 11 a first chamber part 9a the fuel chamber 9 connected, with its inner circumference continues with an end portion 13 a piston 15 the slave device 5 , At one to the membrane 7 opposite end of the fuel chamber 9 , ie in the direction of the pressure surge to the piston 15 considered, the injector points 1 an injection valve 17 at the fuel chamber 9 on, which by means of an injection valve member 17a and a cooperating injector seat 17b is formed. About the injector 17 can fuel from a second chamber part 9b the fuel chamber 9 be applied, which second chamber part 9b over the piston 15 the slave device 5 from the first chamber part 9a is divided. Visible is the second chamber part 9b formed funnel-shaped, wherein the injection valve member 17a is arranged at the outflow end of the funnel neck, the piston 15 at the inlet section of the funnel shape.

The piston 15 the slave device 5 is in through the fuel chamber 9 formed piston receiving or -führung 19 taken up, which differ from the first chamber part 9a towards the second chamber part 9b extends, wherein an annular gap 21 around the piston 15 or between pistons 15 and piston guide 19 an overflow connection between the first 9a and the second 9b Chamber part forms. The fuel chamber 9 this can be done by means of a stepped bore 25 be made, which z. B. in a specially provided Injektorgehäuse 23 is bildbar, wherein the injector housing 23 for example, but can also be formed directly by a cylinder head. To form the first, as an annular volume around the piston 15 provided chamber parts 9a has the stepped bore 25 Here, a first, largest cross-section, to form the piston guide 19 a second, smaller cross-section and forming the second chamber part 9b a third smallest cross section. To the fuel chamber 9 to supply fuel is still a fuel line 27 to the first chamber part 9a guided, for example, provided with a check valve 29 ,

The piston 15 the slave device 5 may also be formed in several parts, as shown, for example, a relatively hard core 15a which is provided to receive a pressure surge from the pressure surge generator. Recorded is the core 15a for example in a cup-shaped piston element 15b , which in this case can be made of a relatively softer material.

With the injector 1 is the receiving device thus formed 5 set up, depending on the intensity of the pressure surge, a corresponding increase in hydraulic pressure in the fuel chamber 9 under deflection of the membrane 7 to effect. Will the piston 15 For this purpose, acted upon by a percussion pulse, the same from the rest position shown in the direction from the first to the second chamber part 9b shifted, whereby in the second chamber part 9b a hydraulic pressure increase is effected. A specially designed ring seal 31 in the circumferential gap 21 between pistons 15 and its leadership 19 in this case causes a blocking of the overflow connection, so that the now the pressure increase exposed fuel in the second chamber part 9b not via the overflow connection in the first chamber part 9a can flow back. Will be an opening pressure of the injector 17 exceeded in the sequence, this opens. In other words, the injector is 1 set up, along with the hydraulic pressure increase in the fuel chamber 9 , in particular in the second chamber part 9b , the injection valve 17 to open or to urge in the open position, ie hydraulically via the fuel in the fuel chamber 9 or the chamber part 9b ,

In this embodiment, with the first chamber part 9a a fuel reservoir is formed from which the annular gap 21 around the piston 15 or the overflow connection at the lowest point of the first chamber part 9a filled with fuel (also works "over head"), allowing largely bubble-free fuel in the second chamber part 9b (for its refilling) can get. Fuel can in this case via the overflow into the second chamber part 9b refill as soon as the pressure in the second chamber part 9b falls off and the sealing element 31 opens.

2 illustrates the design of the ring seal 31 closer in detail. The seal 31 has a number of elastic lips 33 on, which in overflow from the first chamber part 9a in the second chamber part 9b in the flow direction (arrows) are deflected, so that the annular gap 21 partially opened and thus can be flowed through. The pressure in the second chamber part increases 9b , this causes a deflection of the lips 33 in opposite directions Direction so that these are in abutment against the piston 15 arrive, thus shut off the overflow.

Now again referring to 1 points the fuel injector 1 furthermore a (first) restoring device 35 which is provided to the piston 15 after the impact pulse action back to the original, in 1 back home position shown. The reset device is formed 35 by means of a spring 37 , in particular a helical compression spring, which between a piston flange 39 and the step surface 41 the stepped bore in the first chamber part 9a is caught, and the piston 15 in the closing direction of the outwardly opening injection valve 17 urges.

As 1 Also illustrated, the injector includes 1 or its injection valve 17 continue a valve stem 43 , which on the piston 15 is attached. For the attachment of the valve rod 43 is at the injection valve end of the piston 15 a recording room 45 formed in which a head 47 the valve rod 43 is recorded, continue a compression spring 49 which the head 47 in the direction of the pressure surge. The compression spring 49 acts as a valve closing spring and supports a brennraumdruckbedingtes closing of the injector 17 , An axial play between the head 47 and the pressure pad side wall of the receiving space 45 is hereby preferably dimensioned so that the piston 15 when disengaged from the starting position against the head 47 mechanically come into contact and thus the opening process of the injector 17 In the closed position, they can not continue to lean against their heads 47 reaches, so that the reliable receipt of the closed position with the thus formed (second) restoring device 51 is fully guaranteed.

3 now shows a further preferred embodiment of the pressure-operated injector 1 , in contrast to the previously based on 1 and 2 described embodiment, the membrane 7 the slave device 5 directly with the pressure surge or impact pulse - via the pressure surge element 3 - Can be acted upon. In the embodiment according to 3 becomes the taker device 5 first through the membrane 7 itself formed, with which in turn a fuel chamber 9 in the injector 1 is divided, with the partitioned fuel chamber 9 in contrast to the previously described embodiment advantageously small builds, so that even the smallest injector designs can be realized.

After the injector 3 can the injector body 23 have a hollow cylindrical interior, for example, provided as a mere axial bore, with which the fuel chamber 9 is formed. Here is a definition or department of the fuel chamber 9 by means of the membrane 7 it is possible that the membrane 7 spans an injection-valve-proximal, end-side portion of the hollow cylindrical inner cavity, the outer peripheral side, for example, on the wall 11 the internal cavity is attached.

At the thus defined fuel chamber 9 is in turn the injection valve 17 formed, with an (estuary) channel 53 from the fuel chamber 9 towards an injection valve seat 17b extends, which with the injection valve member 17a interacts. The fuel chamber can be affected 9 again via a line 27 which is formed, for example, as a capillary line, or which, to avoid a backflow due to a pressure surge, a check valve 29 having. The administration 27 For example, can be flowed through a fuel supply device of a fuel injection system, for. B. low pressure.

Also in this embodiment of the injector 1 is the taker device 5 , in this case in particular the membrane 7 , Provided to receive a pressure surge from the pressure surge generator and a function of the intensity of the pressure surge, a corresponding (hydraulic) pressure increase in the fuel chamber 9 under deflection of the disc-shaped membrane 7 to effect. However, it is remarkable that the membrane 7 by means of an annular support element 55 is supported on an outer peripheral portion and further on its injection valve remote side, so that a deflection of the membrane 7 at Druckstoßbeaufschlagung and a potential damage to the membrane 7 is prevented.

As 3 Furthermore, it is also in this embodiment of the fuel injector 1 a reset device 51 provided, which is provided, a closing assistance or a closing of the injection valve member 17a to effect. The reset device 51 is by means of a valve rod 43 formed by a support ring 57 at the mouth channel 53 passed through, and which by means of a spring 49 , in particular helical compression spring, which between the support ring 57 and a head 47 the valve rod 43 is trapped, pushed towards the surge absorber.

Again, it can be provided that with deflection of the membrane 7 in the course of a pressure surge opening support takes place in such a way that the membrane 7 at the head 47 the valve rod 43 comes into abutment, ie, thus helping the injection valve member 17a from the injection valve seat 17b to urge.

With the invention, it is possible to inject advantageous significantly smaller amounts of ignition oil than previously known, timed common-rail systems. In addition, the ignition of lean mixtures is possible, which are no longer flammable with a spark plug. Due to the low energy input z. B. in a mobile application with Zündöltank a supply of the ignition system over several thousand kilometers can be achieved without refilling.

LIST OF REFERENCE NUMBERS

1

Pressurized injector

3

Pressure impactor element

5

slave device

7

membrane

9

Fuel chamber

9a

first chamber part

9b

second chamber part

11

peripheral wall

13

end

15

piston

15a

core

15b

cup-shaped piston element

17

Injector

17a

Injection valve member

17b

Injector seat

19

piston guide

21

annular gap

23

injector

25

stepped bore

27

Fuel line

29

check valve

31

ring seal

33

lip

35

Reset device

37

feather

39

flange

41

step

43

valve rod

45

accommodation space

47

head

49

compression spring

51

Reset device

53

channel

55

supporting

57

support ring

Claims (13)

Pressure actuated injector ( 1 ), comprising: - a pressure surge generator, - a slave device ( 5 ) with a membrane ( 7 ), with which membrane ( 7 ) a fuel chamber ( 9 ) in the injector ( 1 ), wherein the slave device ( 5 ) is provided to receive a pressure surge from the pressure surge generator and a function of the intensity of the pressure surge, a corresponding hydraulic pressure increase in the fuel chamber ( 9 ) under deflection of the membrane ( 7 ), the injector ( 1 ) an injection valve ( 17 ) at the fuel chamber ( 9 ), which is urged with hydraulic pressure increase in the open position. Pressure actuated injector ( 1 ) according to claim 1, characterized in that - the injector ( 1 ), with opening of the injection valve ( 17 ) Fuel from the fuel chamber ( 9 ). Pressure actuated injector ( 1 ) according to one of the preceding claims, characterized in that - the slave device ( 5 ) a piston ( 15 ), which is provided for pressure impingement, wherein the piston ( 15 ) with the membrane ( 7 ) and / or together with this the fuel chamber ( 9 ) Are defined. Pressure actuated injector ( 1 ) according to claim 3, characterized in that - by means of the piston ( 15 ) a first, Einspritzventilfernerer chamber part ( 9a ) and a second, injection valve closer chamber part ( 9b ) the fuel chamber ( 9 ) is divided, which via an overflow connection on the piston ( 5 ), the first chamber part ( 9a ) with the membrane ( 7 ), and wherein in the overflow connection a check valve device ( 31 ) is arranged, and wherein the injection valve ( 17 ) at the second chamber part ( 9b ) is formed. Pressure actuated injector ( 1 ) according to claim 4, characterized in that - the second chamber part ( 9b ) can be filled with fuel via the overflow connection, wherein the overflow connection is formed as Kapillarleitung. Pressure actuated injector ( 1 ) according to one of claims 3 to 5, characterized in that - the piston ( 5 ) with a reset device ( 35 . 51 ) is in operative connection. Pressure actuated injector ( 1 ) according to claim 1 or 2, characterized in that - the membrane ( 7 ) as part of the slave device ( 5 ) is provided for direct pressure impingement. Pressure actuated injector ( 1 ) according to claim 7, characterized in that - the membrane ( 7 ) a supporting element ( 55 ) associated with overstressing and / or dodging the membrane ( 7 ) counteracts in the course of a Druckstoßbeaufschlagung. Pressure actuated injector ( 1 ) according to one of the preceding claims, characterized in that - the injector ( 1 ) a valve rod ( 43 ), which with an injection valve member ( 17a ) of the injection valve ( 17 ), wherein the valve rod ( 43 ) with the piston ( 15 ) and / or with a resetting device ( 51 ) is in operative connection Pressure actuated injector ( 1 ) according to one of the preceding claims, characterized in that - the pressure surge is designed as a percussion, in particular for generating pressure surges or impact pulses of variable intensity. Pressure actuated injector ( 1 ) according to one of the preceding claims, characterized in that - the fuel chamber ( 9 ) via a line ( 27 ) can be filled with fuel, which automatically blocks in a pressure surge and / or wherein the line ( 27 ) is a capillary line. Fuel injection system, in particular adapted for an ignition jet method, characterized in that - the fuel injection system comprises at least one pressure-operated injector ( 1 ) according to one of the preceding claims, in particular for a discharge of ignition oil as a fuel. Internal combustion engine, in particular adapted for an ignition jet method, characterized in that - the internal combustion engine has at least one pressure-operated injector ( 1 ) according to one of claims 1 to 11 or a fuel injection system according to claim 12.

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