FI106973B - Injection device for injecting fuel into a stroke piston combustion engine - Google Patents

Description

106973

Injection apparatus for injecting fuel into a percussion piston engine machine

The invention relates to the preamble of claim 1; 5 injection equipment for fuel injection of a percussion piston engine engine. In such injection systems, for example, diesel engines inject fuel at high pressure into the cylinders.

The injection process has taken place at a certain rate, i.e. at the right time and in the right amount. Conventional fuel injection systems with cam controls are mechanically operable and, for example, have only limited flexibility with respect to fuel demand and emission optimization. However, injection systems such as those of the invention are known in passenger cars and trucks. However, not all of these systems are suitable for use with heavy fuel oil 15, they only provide purely time-controlled fuel quantity metering, and the high pressure fuel tank is not leak-proof.

An object of the invention is to provide an injection system in which the injection function is improved. According to the invention, such an injection system is characterized by the features set forth in the characterizing part of independent claim 20. Further, the object of the invention is achieved by the multiple injection apparatus according to claim 6. The dependent claims disclose further preferred embodiments of the invention.

In the improved injection system of the invention, the combustion • ·. the injection of the substance is monitored and controlled by a control piston and a dispensing piston 25.

* The piston is coupled and made to operate in one direction: preferably by means of a hydraulically, electrically operated hydraulic valve. If mechanical operation of the piston is desired for replacement, this is also possible.

30 In the other direction, similar equipment or operation may also be provided in the other direction by the use of pressurized fuel, separate ** ·. its steering hydraulics with steering oils or spring.

The piston controls both the fuel inlet to the dosing piston and the fuel outlet from the dosing piston to the engine cylinder injector: ...: 35. The control portions, e.g. grooves and / or bores, are arranged so that at any position of the control piston, both the fuel inlet to the metering piston and the outlet of the fuel to the cylinder injection valve are not open.

To start the injection, the control piston must be lifted from its seat so that there is a direct connection from the high pressure fuel tank to the injection nozzle. This communication path has a metering piston which is retracted during the fuel injection event. Its distance multiplied by its cross-sectional area precisely determines the volume of fuel to be injected. This distance is measured, for example, by an inductive distance sensor, which acts on the electric control and outputs a signal to stop the injection to the pilot control valve. This further results in the return movement of the piston so that its stop surface is sealed, the connection from the high pressure fuel tank to the injection valve is cut off and thus the injection is stopped.

A volume injection is also provided in connection with the dispensing piston. For example, the injection volume volume may be kept constant despite partially clogged or worn injection nozzles, which would not be possible with purely time-controlled injection. In combination with the ignition pressure measurement arrangement, the injection apparatus according to the invention can be used to control the ignition pressure to a permissible value such that at all times advantageous fuel consumption is achieved.

20 The dispensing piston fulfills another function. In the event of accidental irregularity in the control or clogging of the control piston, it limits the injection volume to the maximum volume in use. In such a case, by measuring the distance traveled by the dosing piston, it can be determined by electronic adjustment that too large a ♦ «4" \ 25 injection occurs. The following and subsequent injections can thus be prevented and indicated.

• · · | · * When such damage occurs, pressure may build up in the spray line, i.i: because the piston is not completely sealed against fuel in the high pressure • · · v. To prevent this, the load control valve 30 can reduce the load on the line. This prevents unlicensed spraying:: ···. In addition, the trip sensor of the dosing piston can also indirectly indicate, for example, broken ends of the injection nozzles, since in such cases the speed of the dosing piston becomes higher than usual during the injection process. This signal can be used to instruct the control elbow 35 to prevent fuel injection into a cylinder with damaged injectors 106973 nozzle and, in that case, to reduce the load on the entire engine and / or to indicate an error in the pointing device.

The dosing piston has to be preconfigured with the signal of the distance measuring device so that the fuel injection by the control piston can be closed at the right time, which allows for a clean control and prevents the injection volume required by the speed controller. When starting the engine, this preset is stored as an approximate battery. After start-up, this ako is constantly adjusted to the actual conditions by means of an adjustable adjustment.

It is readily possible to make the injection apparatus 10 with a single metering piston for a plurality of control pistons, wherein the fuel is supplied to the metering piston space in Saija via all the control pistons. In such a device, fuel can only flow into the metering piston when some fuel channels to the injection nozzles are closed. On the other hand, injection can only take place when all control pistons are open.

The new spraying device provides excellent leak-proof, volume-accurate spraying equipment.

The injection apparatus operates by means of a pressurized fuel metering piston formed as a separating piston. The backside of the batch-20 snow plow is connected to a fuel under high pressure at and above 2,000 bar and pressurized. The steering piston, for example, is actuated hydraulically, which can be electrically controlled by moving it back and forth between the two end positions. The steering piston has • · fuel lines, which guide the fuel from the fuel pump to 25 metering spaces or from the metering space to the cylinder of the percussion piston engine. Steering parts, i.e.. grooves and bores, are preferably so-followed, · · ·: · * that never, i.e. in no position, there is a connection to both the · ·: high pressure fuel pump and the cylinder injection nozzles at the same time.

Embodiments of the invention, i.e. The spray equipment and its 30 functions are explained and described in the following schematic diagrams: ···.

. ···. The figures show:

Figure 1 is a schematic and partially sectioned injection apparatus;

Figure 2 shows a schematic and partially sectioned second injection apparatus which differs from the control piston of Figure 1 with respect to differences in the second embodiment.

4, 106973

Figures 1 and 2 show schematically and partially in cross-section the injection apparatus 1 charged with fuel from a high pressure pump 8 and a tank 81. The fuel inlet channel 2 is branched into a channel 21 which leads to the rear side of a dispensing piston 3 formed as a separating piston, and a main channel 22 through which the fuel is led through the slots 41 of the piston 4 to the in the discharge side, by means of a control oil under pressure, is moved downwardly from the front side 43 of the control piston 4. The pilot control valve receives its control command 10 from the control electronics 7, which ensures that the fuel injection occurs at the right time and in the right amount. Thus, for example, signals are provided to the control electronics from the engine crankshaft angle sensor 71. The sensor 72, which operates, for example, inductively, provides signals to the control electronics Kalle instead of the dosing piston 3. In this case, it is possible that the amount of fuel injection with respect to the injection function can be determined and varied.

As the piston moves downward, the connection between the main channel 22 and the inlet channel section 23 is next closed. Thereafter, the control piston connecting the four grooves 42 of the outlet conduit 24 of injection 25, a lead 20 of a diesel engine 51. The injector 53 of the cylinder 3 to move the dispensing pressure of the fuel to target the dispensing piston to the rear side 31 of the duct 21. Fuel is injected into the motor 5 in the cylinder chamber 52.

When the pilot control valve 61 is closed and the control oil backflow is opened, the control piston 4 is pressed upwardly on the front surface 44 of the control piston 4 under the influence of fuel pressure and spring force. The conduction of the fuel into the conduit 25 is interrupted and is thus passed past the injection end.

In the control piston of Fig. 1, for example, five sealing points are sealed durably against high-pressure fuel.

• «· v; The most important sealing site, namely the one communicating with the injector nozzle, is formed as a socket valve 45, so that between the individual injector functions, ·: ··: the line to the injector nozzle is not pressurized. The valve seat 45 is completely tight when closed. ”*: This can prevent uncontrolled spraying. The second sealing point 46 utilizes the tight fit of the piston 4 and ',.' taking into account the small leakage current of the fuel and recirculating it '·; · '35 through channels 27 back to the fuel tank.

«· ·« «» * · · «· 106973 5

Figure 2 shows a control piston 4 'having only two sealing points 46' where only very small amounts of leakage occur. In this embodiment, the three sealing points continuously seal against the fuel under high pressure. In this embodiment, the hydraulic efficiency 5 is higher than in Variant 1. In addition, the injection apparatus warms up due to reduced leakage flows.

In the case where the guide piston becomes clogged at an arbitrary point, there is a relatively poor seal between the channels 22 and 25. In order to avoid an undesirable increase in pressure and subsequent undesirable injections, the pressure of 10 ducts 25 is lowered by opening a spare valve 80.

In order to achieve a long life of the control valve 4, this is cured on its outer surfaces. In this case, a suitable curing process may be used in each case. The control valves and the associated housing seals can be formed so that they can be easily replaced when worn. Thus, these seals 15 can be inserted into the housing in a conical manner, which allows and simplifies the replacement of these seals with the control piston as a complete control unit.

Multiple cylinder injection nozzles on a percussion internal combustion engine can be controlled simultaneously by one control valve. In particular, when using a high speed pilot valve 61, the control of the injection function can be tailored to the requirements of the engine at full and partial load in the best possible manner.

Multiple control pistons may also be provided in the dispensing piston. with associated pilot valves and injection valves. In this case, individual cylinder injection nozzles can be controlled over time individually.]. *.

* ♦ ♦ | f The control electronics sensor 72 preferably operates inductively. However, there are other measuring systems suitable for capacitive, optical, magnetic, or similar work to monitor and measure the dosing piston space. For the interruption time, ie. System Slowdown ·: ··: Injection system accuracy, to minimize, it can be equipped with * * '*? with adaptive injection volume control with adaptive components.

The actual status and actual speed of the dosing plunger can be monitored and adjusted by comparing these with the set value at each time and the set speed • · '···.

* · · • · 6 106973

Always a deviation, that is. based on the difference between a specified value and a true value, the electronics can eliminate the possibility of injecting too much or too little fuel or injecting fuel too fast or too slowly. The magnitude of this deviation can be used, for example, to trigger an alarm when a predetermined limit value is reached to prevent injection into that cylinder and to reduce engine power.

In the examples shown, the piston is pushed in the closing direction by high pressure fuel, in some cases by a spring. Other types of pushing may also be suitable for pushing the control piston, e.g. a different hydraulic pusher also in the closing direction and not just in the opening direction. The control piston is illustrated in the examples and shown in one piece. However, it is obviously possible for the piston to be made of a plurality of pieces, possibly even different materials or differently processed materials. The individual parts can then be fixedly connected to each other 15 or may be freely connected to each other depending on the pressure and power ratios of the control piston. It is also conceivable that the steering piston operates by means of a mechanical camshaft and a hydraulic piston rod. However, this is extra in case the hydraulic drive is disrupted or damaged.

Injection systems for diesel engines operate at a fuel pressure range of 400 bar to more than 2,000 bar, and the pressure in the hydraulic control circuit may be, for example, in the range of 100 to 400 bar.

The injection apparatus, as shown, can be used to inject both diesel and heavy fuel oil. This allows • a. that the cold engine is started with diesel fuel and as soon as the higher operating temperature required for the heavy fuel oil is reached, switched to the heavy fuel oil.

«« I «« t • 4 * a «i« i «« i «t« 4 * a «i«. · · «·

Claims (12)

7 106973 An injection apparatus (1) for injecting fuel into a percussion internal combustion engine machine (5) having a metering piston (3) and a control piston (4) and guide portions (41, 42) for controlling the metering piston (3) and an inlet (2, 22, 23). for introducing nasal fuel into the inlet (2, 22, 23) of the dispensing piston (3), characterized in that the dispensing piston (3) is formed as a separating piston (30) whose backside (21) is permanently connected to the fuel supply (8, 10 81); the control piston (4) has guide portions (41, 42) for fuel and can take two end positions in its bore, wherein in the first end position the fuel inlet (2, 22, 23) in front of the fuel dosing piston (3) is open and the fuel duct ) from the front face of the blow-15 to the injection nozzle (51) of the cylinder (52, 53) of the reciprocating internal combustion engine (5), and at the other end position the connection of the fuel inlet (2, 22, 23) the groove is closed and the fuel passage (24, 25) from the front of the metering piston (3) to the injection nozzle (51) of the cylinder (52, 53) of the piston combustion engine (5) is open. Injection apparatus (1) according to Claim 1, characterized in that the guide portions (41, 42) are disposed on the piston and the associated fuel passages (2, 22, 23; 24, 25) such that in any position The channel (2, 22, 23) from the pressure accumulator (81) to the metering piston (30) and the fuel channel (24, 25) from the metering piston (30) to the injection valve (51) are not simultaneously open. Injection apparatus (1) according to claim 1 or 2, characterized in that it has an electro-hydraulic control (7; 6, 61) with a piston (4) ·. ♦ ♦ for. Injection device (1) according to claim 3, characterized in that it has a device (32, 72) for instantaneous installation of the metering piston (3). and comparing the actual position and / or actual speed of the metering piston (3) with a preset position and / or speed. Injection device (1) according to one of Claims 1 to 4, characterized in that it has one or more high pressure pumps (8) and; 'I *: One or more pressure accumulators (81). • · «« · • «· • · _ 106973 O Multiple injection apparatus for fuel injection of a percussion internal combustion engine machine (5), comprising a plurality of units having a dispensing piston (3) and a control piston (4) and guide portions (41, 42) for controlling the dispensing piston (3) and inlet (2, 22). 23) for introducing pressurized fuel into the inlet (2, 22, 23) of the dispensing piston (3), characterized in that the dispensing piston (3) is formed as a separating piston (30) whose backside is permanently connected to the fuel supply (8). , 81), the control piston (4) has guide portions (41, 42) for fuel and can take two end positions in its bore, whereby in the first end position the fuel inlet (2, 22, 23) in front of the fuel dosing piston (3) is open. and the fuel passage from the front of the dispensing piston (3) to the injection nozzle (51) of the cylinder (52, 53) of the percussion internal combustion engine (5) is closed, and at the other end position the fuel inlet The connection (2, 22, 23) to the front side of the lifting piston is closed and the fuel channel (24, 25) from the front of the metering piston (3) to the injection nozzle (51) of the cylinder (52, 53) of the piston combustion engine (5) is open. Multiple injection device according to claim 6, characterized in that it has a plurality of guide pistons (4), wherein the number of guide pistons (4) is greater than the number of metering pistons (3). Multiple injection device according to claim 7, characterized in that it has a single dispensing piston (3). a cylinder (52, 53) for a plurality of injection nozzles (51). Multiple injection apparatus according to claim 7 or 8, characterized in that the fuel supply to the plurality of injection nozzles (51) of the cylinder (52) occurs sequentially in a series of several or all control pistons (4). ) through the cable sections (41.42). Injection apparatus according to one of Claims 1 to 9, characterized in that it is intended for injection of diesel or heavy fuel oil into the cylinder (52) of the piston engine engine (5). . * · *. Spraying device according to one of Claims 4 to 10, characterized in that it has an adaptive spraying control (7; 32, 72; 6, 61.) based on a comparison between the actual value and the set value corresponding to the spray rate and / or spray rate. · • · * • * «9 106973 Injection device (1) according to one of Claims 1 to 5, characterized in that the control piston has only two or three gap sealing areas (46) and a valve seat region (45). • • • • • • • • • • • • • • • 10 106973