EP2115291B8

EP2115291B8 - Valve, device and method for generating a fluid pulse

Info

Publication number: EP2115291B8
Application number: EP08707539A
Authority: EP
Inventors: Franz Durst; Bülent Ünsal Dr.-Ing.
Original assignee: FMP Tech GmbH Fluid Measurements and Projects
Current assignee: FMP Tech GmbH Fluid Measurements and Projects
Priority date: 2007-02-05
Filing date: 2008-02-04
Publication date: 2011-09-14
Anticipated expiration: 2028-02-04
Also published as: RU2009133331A; DE102007006415A1; CN101652557A; CA2677433A1; JP2010518299A; US20100089460A1; DE502008003091D1; BRPI0808143A2; WO2008095674A1; EP2115291A1; ATE504733T1; EP2115291B1; MX2009008260A; KR20090117893A

Abstract

The invention relates to a valve (16), in which a fluid inlet opening provided in a valve housing (1) is connected to a fluid outlet opening (3) downstream of the fluid inlet opening by a fluid passage (2) and with a valve closing body (6) which may be moved between a first position which opens the fluid outlet opening (3) and a second position closing the fluid outlet opening (3) by means of an actuator, said body being housed in the valve housing (1). According to the invention, pressure waves are avoided by at least one fluid drain channel (5) branching off the fluid passage (2) via at least one fluid drain opening (4) in the vicinity of the fluid outlet opening (3) and a device is provided in the valve housing for the alternate opening of the fluid drain opening (3) and the fluid outlet opening (4) such that fluid may continuously flow through the fluid passage (2).

Description

Valve, apparatus and method for generating a fluid pulse

The invention relates to a valve and a device and a method for generating a fluid pulse using the valve.

Conventional valves for injecting fuel into the combustion chamber of an internal combustion engine, so-called fuel injection valves, are usually designed such that the fuel supplied to the fuel injection valve is discharged into the combustion chamber exclusively through a fuel injection port provided at the fuel injection valve. In some fuel injection valves, a fuel return line is provided in addition to a fuel supply, which allow a discharge of gas bubbles or cooperates with a pressure control device.

Such a valve is known for example from DE 42 22 628 Al. In this case, the valve designed as a fuel injection valve is inserted into a stepped receiving bore. A fuel supply and a fuel discharge passage are connected to an annular space-like fuel chamber formed between the fuel injection valve and the stepped receiving bore. From the fuel chamber, the fuel passes through the screen body in the fuel injection valve. The fuel return passage is connected to a pressure regulator with which the pressure prevailing in the fuel chamber is regulated as a function of an air pressure prevailing in the combustion chamber.

DE 43 32 118 Al describes a possibility of attachment and electrical contacting of the fuel injection valve described above. An injection system is known from US Pat. No. 6,877,679 B2, in which a piston movable with magnetic coils is provided in a fuel injection valve. In the piston, a fluid passage is provided through which the fluid flows from a fuel feed port to an injection port. A fuel return passage is connected to the fuel supply port via a low pressure pump.

US Pat. No. 6,412,704 B2 describes a fuel injection valve in which the movement of a valve closing body is controlled with a hydraulic actuated by a piezoactuator.

Other fuel injectors are known from U.S. Patents 5,040,727 and 6,029,902. In this case, located in the vicinity of an injection opening, a fuel metering chamber, which is connected to a fuel supply. Further, a degassing line is connected to the fuel metering chamber, so that no unwanted gas bubbles can accumulate in the Brennstoffdosierkammer.

DE 198 47 388 A1 discloses a fuel injection system with fuel injectors that can be cooled by fuel. In this case, for the purpose of cooling a branched off in the vicinity of a nozzle opening return line is provided. The return line is connected via a shut-off throttle valve with a high-pressure pump. To open the nozzle opening, the throttle valve is closed. As a result, the pressure generated by the high-pressure pump increases to the extent that a nozzle needle closing the nozzle opening lifts. In this process, a provided in the vicinity of the nozzle opening opening of the return line is always open. As a result, the pressure generated by the high-pressure pump also acts in the entire region of the return line. The return line or the return system has a certain elasticity. As a result, the volume flow of the injected fuel can not be exactly be controlled. This can lead to relatively large inaccuracies, especially in multiple injections.

DE 196 39 149 C1 describes a similar injection nozzle. Also, a bypass line is connected via a throttle with a high-pressure line. However, the bypass line here branches off relatively far away from the nozzle opening. Again, the bypass line remains open when opening the nozzle opening. The same problems occur as in DE 198 47 388 A1.

When opening and closing a fuel injection port in conventional fuel injection valves, pressure waves pass through the entire piping and pumping system. In particular, with short injection times and high injection frequencies, the pressure fluctuations caused by the pressure waves become so strong that the amount of fuel injected during an injection process can no longer be accurately controlled.

In conventional fuel injection valves, the fuel, which is initially at rest, is accelerated during the injection process and expelled through the fuel orifice. To accelerate the fuel, inertial forces must be overcome. As a result, there is a time delay until the maximum mass flow rate is delivered through the fuel port. This time delay limits further shortening of the fuel injection valve opening times. Such a further shortening of the opening times would enable, in particular, multiple injections during a stroke of an internal combustion engine. Theoretical and experimental investigations have shown that with such multiple injections the combustion process can be further optimized. The object of the invention is to eliminate the disadvantages of the prior art. In particular, a valve, a device and a method for generating a fluid pulse are to be specified with which a high mass flow rate of the delivered fluid can be achieved even with extremely short fluid pulse times immediately after the opening of a fluid outlet opening.

This object is solved by the features of claims 1, 8, 10 and 13. Advantageous embodiments of the invention will become apparent from the features of claims 2 to 7, 9, 11 and 12 and 14 to 18.

According to the invention, it is provided in the valve that at least one fluid exhaust passage branches off from the fluid passage via at least one fluid outlet port provided near the fluid exhaust port, and means is provided in the valve housing for alternately opening the fluid exhaust port and the fluid outlet port such that the fluid passage is uninterrupted can be flowed through with fluid.

In the proposed valve, the fluid outflow opening is alternately opened and the fluid outlet opening is closed or the fluid outflow opening is closed and the fluid outlet opening is opened. The proposed valve operates similar to a double valve, which comprises a main valve and a return valve, which are alternately opened and closed. This ensures that fluid is flowed through without interruption and at a substantially constant speed. The device provided according to the invention for alternately opening the fluid outflow opening and the fluid outlet opening merely causes a deflection of the fluid flowing out of the fluid passage alternately through the fluid outflow and the fluid outlet Fluid outlet openings. As a result, the fluid does not need to be accelerated as it passes through the fluid outlet port. Thus, the formation of pressure waves can be avoided. Significantly shortened opening times can be realized, wherein a high mass flow rate can be achieved immediately after the opening of the fluid outlet opening. The amount of fluid delivered through the fluid outlet port during a fluid pulse can be reproduced with high accuracy.

According to a particularly simple embodiment, it is provided that the valve closing body is received in the fluid passage.

A further advantageous embodiment of the invention is that the valve closing body and the Fluidabströmöff- tion are formed corresponding to each other, so that the valve closing body in the first position, the Fluidab- strömöffnung closes and releases in the second position. It is thus possible to control the alternating opening of the fluid outlet opening and the fluid outlet opening by means of a single adjusting device.

The adjusting device advantageously has a piezoactuator or a magnet coil for moving the valve closing body. It can be provided as a control device also a plurality of piezo actuators or a combination of a piezoelectric actuator with a hydraulic auxiliary device for moving the valve closing body. Such actuators allow short opening times and a high opening frequency.

Appropriately, a device for cooling the fluid outflow channel is provided. This can be at least one or more cooling channels, which are used to dissipate heat to be flowed through with the fluid or a special cooling fluid. The heat dissipating fluid or cooling fluid can also be removed via the Fluidabströmkanal. For cooling, it is also possible to provide a Peltier element which is provided in the region of the fluid outlet channel or is part of the fluid outlet channel.

The valve according to the invention may be a fuel injection valve. In this case, the fluid is liquid fuel.

However, the valve according to the invention may also be a pneumatic valve. In this case, the fluid is a gas, preferably air. The valve according to the invention is particularly suitable as a pneumatic control valve for generating extremely short compressed air pulses.

According to a further aspect of the invention, a device is provided for generating a fluid pulse, in which the fluid inlet opening of the valve according to the invention is connected to a pressure source via a first line, and wherein the fluid outlet channel is provided with a fluid supply via a second line provided downstream of the fluid outlet opening connected is.

Between the pressure source and the fluid supply, a suitable pressure gradient is set, so that an uninterrupted flow of the fluid through the fluid passage is achieved at a predetermined flow rate. The setting of a suitable pressure gradient can be done with conventional throttle valves or the like. will be realized. If a throttle valve is switched on in the second line, it is considered advantageous for it to produce a similar pressure gradient as when the fluid outlet opening is open. This ensures that, irrespective of whether the fluid outlet opening or the fluid outlet opening is just opened, there is always approximately the same pressure in the fluid passage,

The fluid reservoir can be a gas reservoir, for example a liquefied gas vessel, or else the atmosphere. If the device is designed as a fuel injection system, the fluid supply is, for example, a fuel tank.

The proposed device is conventional

Device for generating a fluid pulse with low pressure feedback comparable.

According to another aspect of the invention, a device for generating a fluid pulse is provided, wherein the fluid inlet opening of the valve according to the invention is connected via a first line to a pressure source, and wherein the fluid outlet opening is connected via the second line to the pressure source.

The pressure source may be a high pressure pump or a pressure vessel. If the device is designed as a pneumatic device, the pressure source may also be a compressor.

Also in this case, a pressure gradient is generated between the first and the second line, which allows a continuous flow through the fluid passage. The pressure gradient can be generated, for example, by connecting the second line to a low pressure side of the pressure source.

The proposed device is comparable to a conventional device for generating a fluid pulse, which is designed according to the principle of high pressure return.

Advantageously, the adjusting device for moving the valve closing body comprises an electronic control device with which the opening time of the valve and the opening frequency can be controlled. The control can be done depending on measured or preset parameters. The electronic control device can in particular be designed such that it can be opened and closed several times during a cycle of an internal combustion engine, the fluid outlet opening.

According to a further aspect of the invention, a method is provided for generating a fluid pulse with the following steps:

Providing a valve according to the invention,

alternately opening the Fluidabströmöffnung and the fluid outlet, so that the fluid passage is continuously flowed through with fluid.

With the proposed method, the formation of pressure waves in a device for generating a fluid pulse can be avoided. Furthermore, a high, in particular the maximum, mass flow rate of fluid can thus be conveyed through the fluid outlet opening directly after opening the valve closing body. This allows a significant reduction in opening hours. In this way, multiple injections can be realized in particular in fuel injection system and thus the combustion in an internal combustion engine can be further optimized.

According to an advantageous embodiment, the fluid flow is due to the alternating opening of the Fluidabströmöffnung and the Fluid outlet alternately deflected. As a result, the fluid to be delivered through the fluid outlet opening need not be separately accelerated when a fluid pulse is generated. It can be used by the deflection of the fluid flow immediately contained therein kinetic energy and thus the fluid pulse can be generated. The proposed deflection of the fluid flow avoids the generation of undesired pressure waves in the device for generating fluid pulses in a simple manner.

According to a further embodiment of the method, the valve closing body is used for alternately opening the fluid outlet opening and the fluid outlet opening. For this purpose, the valve closing body can be moved in the direction of the fluid outlet opening between a first and a second position back and forth. With the proposed method steps can be realized in a particularly simple manner suitable for carrying out the method valve or a device for generating a fluid pulse.

According to a further advantageous embodiment, a piezoelectric actuator or a solenoid coil are used as adjusting device for moving the valve closing body. Such actuators allow very short opening times.

Finally, according to a further feature of the method according to the invention, the fluid outlet channel can be cooled.

In the foregoing embodiments, the valve, the device, and the method for generating a fluid pulse have each been described with a fluid outlet port, a fluid exhaust port, and a fluid exhaust port. Of course, it is possible that a plurality of fluid outlet openings are provided in a valve. The fluid outlet opening can also be provided with a valve disk or a be conically designed valve closing body be closed. With regard to the at least one fluid outlet opening, embodiments are possible, as are known in conventional valves, in particular fuel injection valves.

In the foregoing embodiments, the valve and the apparatus and method for generating a fluid pulse have each been described with a fluid outflow port and a fluid outflow port. Of course, in the context of the present invention, it is also possible for a single fluid outflow channel to be branched and connected to the fluid passage via a plurality of fluid outflow openings. The fluid outlet opening can also be designed as an annular channel, which is connected to at least one fluid outlet channel. Of course, it is also possible that a plurality of Fluidabströmkanäle are connected to a plurality of Fluidabströmöffnungen with the fluid passage. For example, two, three, four or five fluid outflow openings may be provided. A minimum overall cross-section, through which the fluid flows through the fluid outflow channel, is expediently larger than a maximum passage cross-section of the fluid outlet opening. This ensures that a sufficient flow velocity of the fluid is always provided. Overall, in the entire device for generating a fluid pulse, the openings through which the fluid flows have to be matched to one another in their flow cross-section such that a predetermined desired pressure prevails at the fluid outlet opening.

Embodiments of the invention will be explained in more detail with reference to the drawing. Show it:

1 shows a valve with a valve closing body which is in a first position, 2, the valve of FIG. 1, wherein the valve closing body is in the second position,

3 is a plan view of FIG. 2,

4 is a schematic view of another valve,

5 shows the rate of mass flow over time for a valve according to the prior art,

6 is a comparison of the mass flow rate over time for a valve according to the prior art with a valve according to the invention,

7 shows a device for generating a fluid pulse with high-pressure return,

Fig. 8 shows a device for generating a fluid pulse with low pressure feedback and

9 shows a device according to FIG. 8 with cooling.

In FIGS. 1 to 3, a valve housing 1 with a fluid passage 2 is provided, which has a fluid outlet opening 3. In the vicinity of the fluid outlet opening 3, two fluid outlet passages 5, which are connected to the fluid passage 2 via fluid outlet openings 4, branch off.

In the fluid passage 2, a valve closing body 6 is provided, which with a (not shown here) adjusting device in the axial direction is movable back and forth. The valve closing body 6 has, at its free end, in this case a conical design, first closing surfaces 7, which are provided with second closing surfaces 8 provided on the valve housing 1 in this way Correspond that the fluid discharge opening 3 in a first position of the valve closing body 6 - as shown in Fig. 1 - can be closed.

The valve closing body 6 also has projections 9 extending radially therefrom with third closing surfaces 10 provided thereon. The third closing surfaces 10 adjoin the first closing surfaces 7 or are arranged close to the first closing surfaces 7. The projections 9 and the third closing surfaces 10 provided thereon extend in the axial direction only over a lower portion of the valve closing body 6.

1 shows the valve closing body 6 in the first position in which the fluid outlet opening 3 is closed and at the same time the fluid outlet openings 4 are opened. In the first position, the fluid outlet openings 4 are opened and the fluid flows through the fluid passage 2 into the fluid outflow channels 5.

Fig. 2 shows the valve closing body 6 in a second position, in which the first 7 and the second closing surfaces 8 are removed from each other. In the second position, the third closing surfaces 10 close off the fluid outlet openings 4. In this case, the fluid 2 flows through the fluid passage 2 and through the fluid outlet opening 3.

FIG. 3 shows a plan view according to FIG. 2. It can be seen from this that the fluid passage 2 is formed at least in sections in the manner of an annular space, at least in the region of the valve closing body 6.

Although not shown in FIGS. 1 to 3, it goes without saying that in the valve housing 1 upstream of the Fluid passage 2, a fluid inlet port for supplying fluid is provided.

Fig. 4 shows schematically a further valve. In this case, the fluid passage 2 branches into a first branch al, at the end of which the fluid outlet opening is provided. A second branch a2 is arranged symmetrically with respect to an axis A of the fluid passage 2 to the first branch al, d. H. a first angle α1 between a first axis Al of the first branch al and the axis A is the same as a second angle α2 between the axis A and a second axis A2 of the second branch a2. The fluid outflow opening 4 is arranged downstream of a not shown here Fluidabströmkanal downstream. The fluid outlet opening 3 and the fluid outlet opening 4 are each provided with a valve (not shown here) with which the fluid outlet opening and the fluid outlet opening can alternately be opened or closed. The proposed further valve has the advantage that due to the symmetrical arrangement of the branches al, a2 with respect to the fluid passage 2 in a simple manner, the flow resistance downstream of the fluid passage 2 can be kept substantially constant, regardless of whether just the fluid outlet or the Fluidabströmöffnung is open. In this way, any generation of pressure waves can be avoided in a particularly simple manner.

Fig. 5 shows a numerical simulation of the mass flow rate over time for a valve according to the prior art. The curve lit. a represents the mass flow rate over time in a first conduit connected to a fluid inlet port for delivery of fluid. The curve lit. b represents the course of the mass flow rate over time in a section of the fluid passage 2, which is located immediately in front of the fluid outlet opening 3. As shown in particular from the curve lit. a is apparent, occur in conventional Valves pressure waves in the first line. As shown in the curve lit. b, the mass flow rate continuously increases after opening the fluid outlet opening to a maximum value. Ie. immediately after opening the fluid outlet opening, the maximum mass flow rate is not reached. This effect is explained by the current state of knowledge in that immediately before opening the fluid outlet, the fluid is at rest and must be accelerated first. The acceleration results in a finite rate of change of the fluid delivered through the fluid outlet port. When the fluid outlet opening is opened, a negative pressure wave forms, which counteracts the actual acceleration of the fluid.

Fig. 6 shows a comparison of the mass flow rate over time for a conventional valve with a valve according to the invention. The curve lit. c gives the progression of the mass flow rate over time for a conventional valve and the curve lit. d the course of the mass flow rate for a valve according to the invention again. Which is clear from Fig. 6 is the

Mass flow rate in the valve according to the invention immediately after the opening of the fluid outlet significantly higher than the valve of the prior art. A maximum value of the mass flow rate is achieved in the valve according to the invention already one millisecond after the opening of the fluid outlet opening. In this way, a particularly high mass flow rate can be reproducibly realized at considerably shortened opening times. The opening hours can be shortened considerably. Apart from that, it is possible to achieve the maximum mass flow rate almost immediately after opening the fluid outlet opening. The advantageous effects of the valve according to the invention are attributed in particular to the fact that the fluid does not have to be accelerated before opening the fluid outlet opening. A particularly ne fluid flow through the fluid passage 2 is merely deflected by the movement of the valve closing body 6.

FIGS. 7 and 8 show devices for generating a fluid pulse using the example of a fuel injection system for liquid fuel. The device shown in Fig. 7 is a high pressure feedback fuel injection system. In a fuel tank 11, a fuel pump 12 is provided. The fuel pump is connected via a first line 15 to the fluid inlet opening of the fuel injection valve, generally designated by the reference numeral 16, with the interposition of a fuel filter 13 and a pressure regulator 14. The pressure regulator 14 is also connected to the fuel pump 12 with the interposition of a ramjet pump 14a. A second line 7 is connected to the fluid discharge opening (s) via the fluid discharge channel (s). Upstream, the second line 17 is connected to a high-pressure pump 18 which in turn is connected to a high-pressure container 19 which is switched into the first line 15.

Fig. 8 shows a fuel injection system with low pressure feedback. In this case, the second line 17 is connected directly to the fuel tank 11. In the first line 15 no high-pressure vessel is turned on.

In both variants of the fuel injection systems shown fluid is continuously pumped through the valve 16. The fluid is constantly under the required injection pressure or pressure for the generation of a fluid pulse.

The proposed device for generating a fluid pulse can be used as a fuel injection system for injecting liquid fuel in internal combustion engines, in particular gasoline or diesel engines. The invention measure proposed valve or the device for generating a fluid pulse can also be used for pneumatic devices. In this case, a gas, for example compressed air, is used as the fluid. The proposed valve enables the generation of extremely short opening times and thus extremely short valve pulses, which enable particularly fast and exact control of pneumatic devices.

FIG. 9 shows a variant of the fuel injection system according to FIG. 8. A cooling device 20 is provided in the second line 17. With the cooling device 20, the fluid returned to the fuel tank 11, in particular liquid fuel, is cooled. It is thus prevents undesired heating of the fluid in the fuel tank 11.

The cooling device 20 may be a conventional cooling device, for example a heat exchanger or the like. , act.

LIST OF REFERENCE NUMBERS

1 valve housing

2 fluid passage

3 fluid outlet opening

4 fluid outlet opening

5 fluid outlet channel

6 valve closing body

7 first closing surfaces

8 second closing surfaces

9 lead

10 third closing surfaces

11 fuel tank

12 fuel pump

13 fuel filters

14 pressure regulator

14a ramjet pump

15 first line

16 valve

17 second line

18 high pressure pump

19 high pressure tanks

20 cooling device

αl, α2 first, second angle

A axis

Al first axle

A2 second axis al first branch a2 second branch

Claims

claims

A valve in which a fluid inlet port provided in a valve housing (1) is connected to at least one fluid outlet port (3) provided downstream of the fluid inlet port, and wherein in the valve housing (1) a fluid outlet port is provided in the valve housing (1) (3) releasable first in a the fluid outlet opening (3) closing the second position movable valve closing body (6) is accommodated,

characterized in that

at least one fluid outlet channel (5) branches off from the fluid passage (2) via at least one fluid outlet opening (4) provided in the vicinity of the fluid outlet opening (3), and in that

in the valve housing means for alternately opening the Fluidabströmöffnung (4) and the fluid outlet opening (3) is provided, so that the fluid passage (2) is continuously flowed through with fluid.

2. Valve according to claim 1, wherein the valve closing body (6) in the fluid passage (2) is accommodated.

3. Valve according to one of the preceding claims, wherein the valve closing body (6) and the Fluidabströmöffnung (4) is formed corresponding to each other, so that the valve closing body (6) in the first position, the Fluidabström- opening (4) closes and in the second position releases.

4. Valve according to one of the preceding claims, wherein the adjusting device for movement of the valve-closing body (6) comprises a piezoelectric actuator or a magnetic coil.

5. Valve according to one of the preceding claims, wherein means for cooling the Fluidabströmkanals (5) is provided.

6. Valve according to one of the preceding claims, wherein the valve (16) is a fuel injection valve and the fluid is liquid fuel.

7. A valve according to any one of claims 1 to 5, wherein the valve (16) is a pneumatic valve and the fluid is a gas.

8. A device for generating a fluid pulse, wherein the fluid inlet port of the valve (16) according to claim 1 via a first line (15) is connected to a pressure source, and wherein the Fluidabströmkanal (5) via a downstream of the Fluidabströmöffnung (4) provided second Line (17) is connected to a fluid reservoir.

9. Apparatus according to claim 8, wherein the fluid reservoir is a gas reservoir or a fuel tank (11).

10. A device for generating a fluid pulse, wherein the fluid inlet port of the valve (16) according to claim 1 via a first line (15) is connected to a pressure source, and wherein the Fluidabströmöffnung (3) via a second line (17) with the pressure source connected is.

11. The apparatus of claim 10, wherein the pressure source is a high-pressure pump (18) or a pressure vessel (19).

12. The apparatus of claim 10 or 11, wherein the pressure source is a compressor.

13. A method of generating a fluid pulse comprising the steps of: Providing a valve (16) according to claim 1,

alternately opening the fluid outlet opening (4) and the fluid outlet opening (3), so that the fluid passage (2) is continuously flowed through with fluid.

14. The method of claim 13, wherein the fluid flow is alternately deflected by the alternate opening of the Fluidabströmöffnung (4) and the Fluidauslassöffnung (3).

15. The method according to claim 13 or 14, wherein for alternately opening the Fluidabströmöffnung (4) and the Fluidauslassöffnung (3) of the valve closing body (6) is used.

16. The method according to any one of claims 13 to 15, wherein the valve closing body (6) for alternately opening the Fluidabströmöffnung (4) and the Fluidauslassöffnung (3) in the direction of the Fluidauslassöffnung (3) between a first and a second position is reciprocated.

17. The method according to any one of claims 13 to 16, wherein a piezoelectric actuator or a solenoid coil are used as adjusting device for moving the valve closing body (6).

18. The method according to any one of claims 13 to 17, wherein the Fluidabströmkanal (5) is cooled.