KR100364070B1 - Fuel injection device of reciprocating piston internal combustion engine - Google Patents

Abstract

The fuel injection device 1 operates with a metering piston 3 driven by fuel under pressure, that is, a metering piston 3 formed as a differential piston. The rear end 31 of the metering piston 3 is connected to a fuel under high pressure up to 2000 bar and above, and is operated by this fuel. The control piston 4 is moved up and down between the two end positions by, for example, hydraulic drivers 6, 61; 7 which are electrically controlled. The control piston 4 has fuel guide elements 41 and 42 through which fuel is supplied from the fuel pumps 8 and 81 to the metering piston space 30 or from the metering piston space 30 to the reciprocating piston internal combustion. It is supplied to the cylinders 52 and 53 of the engine 5. The control or guide elements 41, 42, ie the grooves and the bores are advantageously arranged, ie connected to the high pressure fuel pumps 8, 81 or to the injection nozzles 51 of the cylinders 52, 53 at any position. It doesn't work.

Description

Fuel injection device of reciprocating piston internal combustion engine

The present invention relates to a fuel injection device for a reciprocating piston internal combustion engine having an adjustment piston, a control piston having a guide member for controlling the adjustment piston, and a flow passage for sending pressurized fuel to the adjustment piston. In such an injector, for example a diesel engine, combustion fuel is injected into a cylinder under high pressure.

The injection process takes place in a very special cycle, at the right moment and in the right amount. Conventional fuel injection systems by cam control are mechanically complex and, moreover, only flexible in a limited way, for example for optimization of fuel consumption and emissions. Injection systems such as those described above of the present invention are known for passenger cars and freight cars, but all of these systems are not suitable for heavy fuel oil operation and only have a purely time-controlled fuel volume adjustment and high pressure fuel. The tank is not protected from leakage.

The main object of the present invention is to provide an injection apparatus with an improved injection process. According to the present invention, such an injector is provided with an adjustment piston whose rear is always connected to the fuel passage via a channel, the control piston having a fuel guide member, which can take two end positions of the bore. At the same time, in the first end position, the fuel flow passage is opened to supply fuel to the front of the adjustment piston, and the fuel channel from the front of the adjustment piston to the injection nozzle of the cylinder of the reciprocating piston internal combustion is closed, and the second end is closed. In the position, the fuel flow passage directed toward the front of the adjustment piston is closed, and the fuel channel from the front of the adjustment piston to the injection nozzle of the cylinder of the reciprocating piston internal combustion engine is opened. Dependent claims relate to more advantageous examples of the invention.

In the improved injector of the invention, the injection of fuel is controlled and monitored by the control piston and the adjustment piston.

The control piston is hydraulically driven, advantageously switching in one direction through the electrohydraulic valve. This is also possible if mechanical drive of the control piston is desired for redundancy reasons.

Corresponding configurations may also be provided in other directions, or driving in other directions may be done with a separate hydraulic control system or spring using pressurized fuel, control oil.

The control piston controls the fuel inlet to the adjustment piston and also the fuel outlet from the adjustment piston space to the injection nozzle of the engine cylinder. Since the guide member, for example, the groove and the bore are arranged, both the fuel inflow to the adjustment piston and the fuel outflow to the cylinder injection nozzle are simultaneously opened at any position of the control piston.

In order to start the injection, the control piston must be raised so as to be connected directly from the high pressure tank of fuel to the injection nozzle. The adjusting piston is in this connecting passage and is slowly drawn by the fuel during the injection process. The flow path whose cross sectional area is increased injects the fuel amount accurately. This flow path is recorded by, for example, an inductive flow path sensor, processed by electric control, and sent to the pre-control valve as the end of the injection signal. Next, since this induces reverse movement of the control piston, the seat is sealed, and the connection from the fuel high pressure tank to the injection nozzle is interrupted, thus the injection is finished.

In this way, volume injection is realized by the adjustment piston. For example, the injection amount can be kept constant even in the case of partially clogged or cleaned injection nozzles, which is not possible with purely time controlled injection. With the ignition pressure measuring device, the ignition pressure can be adjusted to an allowable value with the injector according to the present invention, so that optimum fuel consumption is always obtained.

The adjusting piston serves another purpose. In the case of malfunction of the control or blocking of the control piston, the adjustment piston limits the injection amount to the amount most effectively provided during operation. In such a case, it can be determined that the injection has occurred too large through the flow path measurement in the adjustment piston of the electric control. In this way, the next and other injections can be suppressed and displayed.

When such damage occurs, the pressure can be increased in the injection line since the control piston is not absolutely sealed to the fuel under high pressure up to 2000 bar and above. To prevent this, the line can be relaxed with a relief control valve. This prevents uncontrolled injection. Further, for example, a broken injection nozzle can also be determined indirectly by the adjustment piston flow sensor, because in this case, the speed of the adjustment piston during the injection process becomes larger than usual. In response to this signal, the control electronics can suppress fuel injection to the cylinder with a damaged injection nozzle, reduce the overall load of the engine if necessary and / or display a fault on the display.

Since the preceding value must be added to the signal of the adjusting piston flowmeter, it is possible to finish the fuel supply to the control piston in a time zone, which enables complete adjustment and prevents the injection amount required by the speed regulator from being exceeded. During engine startup, this preceding value is a stored approximation. After startup, this value is continuously adapted to the instantaneous state by appropriate adjustments.

It is readily possible to make an injector with one adjusting piston for a plurality of control pistons, and the fuel supply to the adjusting piston space must be directed continuously for all control pistons. In such an apparatus, fuel can only enter the adjusting piston space when all the fuel lines to the injection nozzle are closed. On the other hand, injection can only occur when all the control pistons are open.

As a novel injector in particular an injector is achieved which does not leak and works correctly in volume.

The fuel injection device acts as an adjustment piston driven by pressurized fuel, that is, an adjustment piston formed as a differential piston. The rear of the adjustment piston is connected to the fuel under high pressure up to 2000 bar and above, and is operated by this fuel. The control piston moves up and down between the two end positions, for example by an electrically controlled hydraulic driver. The control piston has a fuel guide member, through which fuel is supplied from the fuel pump to the adjustment piston space or from the adjustment piston space to the cylinder of the reciprocating piston internal combustion engine. Since the guiding member, i.

Next, embodiments of the present invention will be described in detail.

1 and 2 are schematic partial cross-sectional views of the fuel injection device 1, and fuel is supplied to the injection device 1 by the high pressure pump 8 and the accumulator 81. The fuel inlet channel 2 branches into a channel 21 and a main channel 22 at the rear of the adjustment piston 3 formed as a differential piston, which main channel 22 is a guide member of the control piston 4. The fuel is guided into the adjustment piston space 30 through the groove 41 and the inlet channel 23. When the pre-control valve 61 of the control hydraulic pressure 6 having the supply path and the return path is driven by the control oil under pressure, the upper end 43 of the control piston 4 moves downward. The pre-control valve receives its control command from the regulator electronics 7, which ensures that the fuel injection process occurs at the right moment and in the correct amount. In this manner, the signal is transmitted to the regulator electronic device 7 by the angle transmitter 71 on the crankshaft of the engine, for example. For example, the inductively operated transmitter 72 transmits a signal regarding the position of the shaft 32 of the adjusting piston 3 to the regulator electronics 7. In this way, it is possible to determine and change the fuel injection amount per injection process.

When the control piston moves downward, the connection between the main channel 22 and the inlet channel 23 is interrupted. The outlet channel 24 is then connected to the injection channel 25 via a groove 42 which is a guide member of the control piston 4, which is guided to the injection nozzle 51 of the cylinder 53 of the diesel engine. . The adjusting piston 3 is moved by the pressure exerted on the rear 31 of the adjusting piston by fuel through the channel 21. The fuel is injected into the cylinder space 52 of the engine 5, which is a reciprocating piston internal combustion engine.

When the pre-control valve 61 is closed and the return path for the control oil is opened, the control piston 4 is upward by the force of the fuel pressure and the spring acting on the lower end 44 of the control piston 4. Pushed. Then, the fuel supply to the channel 25 is stopped, and thus the injection ends.

For example, five seal portions are continuously sealed from the fuel under high pressure in the control piston of FIG. The most important seal, in particular the position connected to the injection nozzle, is formed as a valve seat 45, so that the connection channel 25 to the injection nozzle is not pressurized between each injection process. The valve seat 45 is completely sealed in a closed state. This can prevent uncontrolled injection. In the remaining seal portion 46, the control piston 4 is in close contact, but some leakage of the flow of fuel is allowed and once again returns to the fuel tank via the return channel 27.

2 shows the control piston 4 'having only two seal portions 46' leaking in very small amounts. In this embodiment, three seal portions are continuously sealed from the fuel under high pressure. This embodiment has a higher hydraulic efficiency than the previous embodiment. This injector is also less heated due to less leakage flow.

When the control piston is blocked at any position, the seal between the channel 22 and the channel 25 becomes relatively poor. The relief valve 80 is opened to lower the pressure in the channel 25 in order to prevent undesired rise in pressure and hence unwanted injection.

It hardens on the surface in order to make the control piston 4 life longer. To achieve this, any suitable curing process may be used. Since they can be formed from a control piston and a liner coupled thereto, they can be easily replaced when they are worn out. As such, the liner can be inserted into the housing as a cone, which makes it possible and simple to replace this liner with the control piston as a complete control unit.

One control piston can simultaneously drive a plurality of injection nozzles of a cylinder of a reciprocating piston internal combustion engine. In particular, when using the high speed pre-control valve 61, the control of the injection process can be adapted in the best way to the requirements of the full load or partial load engine.

In addition, a plurality of control pistons combined with a plurality of pre-control valves and injection valves can be arranged together with one adjustment piston. In this case, the individual injection nozzles of the cylinder can be driven individually temporarily.

The transmitter 72 for the regulator electronics 7 advantageously operates in an inductive manner. However, other measurement systems that operate capacitively, optically, magnetically, or in other ways may be suitably used to monitor and measure the position of the adjustment piston. In order to minimize the effect of delay time, i.e. system delay, on the functioning precision of the injector, suitable injection quantity adjustments can be made with the appropriate components.

The monitoring and control of the actual position and the actual speed of the adjusting piston can be compared with the set position and the set speed at any time.

The electronics can induce a difference, or deviation, between the set point and the actual value whether too much or too little fuel is injected or whether the fuel is injected too quickly or too slowly. By using the magnitude of these deviations to reach a preset threshold, for example, the alarm starts to sound, the injection of the affected cylinder is suppressed, and the engine power is reduced.

In the above examples, the control piston is driven in a direction closed by the fuel under high pressure, and in some cases additionally driven by a spring. However, other drive types are also suitably available for the drive of the control piston, for example a separate hydraulic drive in the closed direction rather than necessarily in the open direction. The control piston of this example is described and illustrated as one member. However, it is readily possible to make the control piston from other or differently treated materials from a plurality of parts. The individual parts can then be firmly connected to each other as a result of the pressure and force states in the control piston or simply contact each other continuously. It is also conceivable to drive the control piston with a mechanical camshaft and hydraulic rack. However, this is only preliminary for cases where hydraulic drive is incomplete or impossible.

The injector of the diesel engine operates at fuel pressure within the range of 400 to 2000 bar and above, and the pressure of the hydraulic control circuit operates at a pressure within the range of 100 to 400 bar.

The injector as shown can be used for the injection of diesel oil and heavy oil. This makes it possible to start the cooled engine with diesel oil and convert it to heavy oil as soon as the higher operating temperature required for heavy oil is reached.

1 is a schematic partial cross-sectional view of a first fuel injection device.

FIG. 2 is a schematic partial sectional view of a second fuel injection device according to another embodiment different from the control piston of FIG.

Claims (13)

Control piston 4 having an adjustment piston 3, guide members 41 and 42 for controlling the adjustment piston 3, and flow paths 2 and 22 for sending pressurized fuel to the adjustment piston 3. In the fuel injection device 1 of the reciprocating piston internal combustion engine 5 having 23, The adjusting piston 3 is formed of a differential piston whose rear 31 is always connected to the fuel passages 8, 81 through the channel 21, The control piston 4 is provided with fuel guide members 41 and 42 and may take two end positions of the bore, and in the first end position, the fuel flow path facing the front of the adjustment piston 3. 2, 22 and 23 are opened to supply fuel, and the fuel channel from the front of the adjusting piston 3 to the injection nozzle 51 of the cylinders 52 and 53 of the reciprocating piston internal combustion engine 5 is closed. , In the second end position, the fuel flow passages 2, 22, and 23 facing the front of the adjusting piston 3 are closed, and the cylinder 52 of the reciprocating piston internal combustion engine 5 is opened from the front of the adjusting piston 3; A fuel injection device in which fuel channels 24 and 25 directed to the injection nozzle 51 of 53 are opened. 2. Fuel channels 24 directed from the accumulator 81 to the adjusting piston space 30 and from the adjusting piston space 30 to the injection nozzle 51 at any position. Fuel injection device (41,42) and fuel channels (2,22,23; 24,25) of the control piston are arranged so that the (25) are not opened simultaneously. The fuel injection device according to claim 1 or 2, further comprising an electro-hydraulic controller (7; 6, 61) for the control piston (4). A device (32, 72) for monitoring the instantaneous position of the adjusting piston (3) and for comparing the actual position or actual speed of the adjusting piston (3) with a preset position or speed. Fuel injection device. The fuel injection device according to claim 1 or 2, further comprising at least one high pressure pump (8) and at least one pressure accumulator (81). A multiple fuel injection device having a plurality of fuel injection devices (1) according to claim 1 or 2 for injecting fuel into a plurality of cylinders (52, 53) of an internal combustion engine (5). 7. A multi-fuel injection device according to claim 6, comprising a larger number of control pistons (4) than the number of adjustment pistons (3). 8. A multi-fuel injection device according to claim 7, having one adjustment piston (3) for a plurality of injection nozzles (51) of one cylinder (52, 53). 8. The multi-fuel injection device according to claim 7, which guides the sequential fuel supply to the plurality of injection nozzles 51 of the cylinder 52 continuously through the guide members 41 and 42 of the plurality or all the control pistons 4. . The fuel injection device according to claim 1 or 2, wherein diesel fuel or heavy oil is injected into the cylinder (52) of the reciprocating piston internal combustion engine (5). 5. A fuel injection device according to claim 4, having an injection control system (7; 32, 72; 6,61) adapted to suit the injection speed or injection amount based on a comparison of the corresponding actual and set points. A reciprocating piston internal combustion engine (5) comprising a fuel injection device (1) according to any one of the preceding claims. A control piston (4) for a fuel injection device (1) according to claim 1, having only two or three gap seal regions (46) and one valve seat region (45).