KR20000023307A - Reciprocating piston combustion engine - Google Patents

Abstract

PURPOSE: A reciprocating piston combustion engine is provided to be used for not only a main engine for propelling a ship but also a fixing device for generating. CONSTITUTION: A reciprocating piston combustion engine comprises of: a jetting system(11); a gas exchange system for a cylinder(12); plural pumps(3,7,107,15); accumulators(5,8,108) for more than one fuel and control medium; a hydraulic system equipped with a member(14) for controlling the injection and the gas exchange; a lubricating device for each cylinder; more than one angle sensors(25,26); and a control device(21) equipped with plural electronic control modules(92). Thereby the combustion engine is electrically controlled in a normal operation.

Description

Reciprocating piston combustion engine {RECIPROCATING PISTON COMBUSTION ENGINE}

The present invention relates to a reciprocating piston combustion engine having a plurality of cylinders, in particular a two-stroke diesel engine.

Internal combustion engines, in particular two-stroke diesel engines, are used not only as main engines for ship propulsion but also as stationary devices for power generation. The combustion engine has a control shaft (camshaft) for operating the fuel pump through a cam mounted thereon, and the gas exchange valve is connected via a cam and a thrust rod. It is actuated by a control shaft or by a pump actuated by a cam, ie a hydraulic thrust rod and a piston drive. The control shaft already shows high manufacturing cost and complexity, the bearing of the reversal mechanism of the engine which is large, heavy and bidirectional over the entire length of the engine must be lubricated by oil, In particular at least two (up to four) gears (and / or chains) are needed to drive the control shaft with a crankshaft. There is also a need for a damping apparatus for torsion oscillation.

The disadvantages in the manufacture of combustion engines of the above kind are, on the one hand, that the start time of injection and the opening and closing time of the gas exchange valve are set constant by each cam, and on the other hand, the variable operation of the gas exchange valve And / or more effort is required in manufacturing for variable initiation of the injection.

It is an object of the present invention to improve a reciprocating piston combustion engine having a plurality of cylinders by avoiding the above disadvantages.

The advantage of the present invention is that by using an electronic control system, more economical combustion engine design, less fuel consumption, less pollution emissions, lower part temperature rise, simpler maintenance and more reliable operation can be realized. . In addition, by improving the operation of the combustion engine at a rotational speed of 25% lower than the normal rotational speed, the combustion engine can be operated continuously through improved smooth running, especially while traveling at narrow speeds at low speeds.

1 is a schematic diagram showing an embodiment of a two-stroke diesel engine according to the present invention;

2 shows a schematic view of the combustion engine according to FIG. 1;

3 is a schematic view showing an embodiment of the injection apparatus.

4 is a schematic diagram illustrating a gas exchange system.

5 is a block diagram of a control system for a combustion engine.

6 is a schematic view showing another embodiment of an injection device.

FIG. 7 is a detail view of A in FIG. 4; FIG.

The invention is described as follows with reference to the accompanying drawings introduced above.

See FIGS. 1 to 3. 1 shows a two-stroke diesel engine having, for example, four cylinders which are not illustrated and in which the operation of the gas exchange valve, cooperation between fuel supply and piston position, is electronically controlled. The combustion engine has a first gear 1 mounted to the crankshaft and a second gear 2 meshing with the first gear. The second gear 2 is present in the mechanical drive for auxiliary energy and can be used in the case of a certain number of cylinders to drive the compensation of secondary inertia forces. The combustion engine is connected via a high pressure pump 3, preferably a suction restrictor pump that variably compresses the fuel, a pressure regulator actuator 4, a tubular line 6. Accumulator for fuel (5) connected to the high pressure pump, pressure pump (7, 107) for control oil and accumulator for control oil (8) connected to compression pumps (7, 107) via piping line (109) 108, in each case only one pump, one accumulator and one piping line are illustrated. The fuel high pressure pump 3 is driven by the second gear 2, and the control oil pump 107 is driven by an auxiliary motor.

As shown in FIG. 2, the cylinder is provided with a gas exchange system 12 connected with an injection system 11 and a third accumulator 8 which are connected to the accumulator 5 as well as to the second accumulator 108.

The accumulators 5, 108 are tubular components with or without fittings. In accumulators without fittings, the storage capacity preferably depends only on the elasticity of the media to be stored. The accumulator 5 is provided with a safety valve 16 for limiting the maximum pressure in the accumulator to a set value and a pressure sensor 17 for measuring the pressure in the accumulator.

The compression pumps 7 and 107 and the pre-control valve 14 of the respective accumulators 8 and 108 for hydraulic oil or control oil are in each case a hydraulic pressure for controlling the injection system and the gas exchange system. A filter 13 is provided in front of each pump and each accumulator 8, 108 provided with pressure sensors 18, 19. At the inlet and outlet of the hydraulic control system and at the fuel line between the accumulator 5 and the injection system 11 valves 40, 41, 42 which allow the injection system of each individual cylinder to cut off from the engine. Is installed so that the injection system can be repaired while the engine is running.

The combustion engine has an electronic control device. In order to measure the rotational speed of the crankshaft and the crankshaft angle, an angle sensor 25 is coupled to the crankshaft without slipping and tolerance via mechanical means, the crankshaft being connected to the second gear 2. The angle sensor rotates at the rotational speed of the engine since power can be transmitted between and the angle sensor 25. Two reference sensors 26 are provided to monitor the synchronization between the crankshaft and the angle sensor.

The control device comprises at least one central unit 21, a control module 22 for each cylinder, a remote control 23 and a rotational speed regulator 24. The central unit 21 and the control module 22 are connected via a data bus, but the control module forms an independent control unit assigned a fixed range of tasks. The remote controller 23 is connected to the central unit in a signal transmitting manner. Pressure sensors 17, 18 and 19 are also connected to the central unit. The central unit 21 is also connected to one or more high pressure pump pressure regulator actuator 4 for fuel and one or more pressure setting members of the one or more high pressure pump 7 for hydraulic oil. ) The control module 22 comprises a preliminary control valve 14 of the injection system 11 and a preliminary control valve 14 of the gas exchange system 12 as well as a measurement system 71 and a volumetric system of the gas exchange system. It is also connected to a measurement system 36 for (volumetric) injection (see FIG. 7).

The central unit 21 includes a storage device in which all the functions related to the engine are stored. The control module likewise comprises a storage device in which the functions relating to the cylinder are stored.

The central unit 21 forms the interface of a sensor, a rotational speed regulator and a remote controller (driver interface) associated with the engine to the control unit of the cylinder. In addition, the pressure of the various media must be controlled.

According to the data supplied, each of the engine's temporary and desired operating states is determined at the central unit and communicated to the control module 22 via the bus.

The control module 22 determines the data according to the injection time, the injection amount and the gas exchange control time in consideration of the offset time and the delay time of the individual cylinder. In the present embodiment, the central unit 21 is provided in a redundant form for safety. Even if a problem occurs in one cylinder, continuous operation is ensured, so if a problem occurs in the control module 22, the new control module may be replaced.

Since the variant embodiment has only one central unit 21, the central unit may comprise only the function of the pressure regulator and the interface to the driver. Both functions are backed up by a simple backup system independent of the central unit. All other data and functions are collected in each individual control module 22, whereby the engine can still be operated even if a problem occurs in the central unit 21 and the control module 22.

In the following, an injection system 11 consisting of for example three fuel nozzles 31 for each of four cylinders and an injection device 32 and one or more preliminary control valves 14 associated with the cylinders will be described. will be.

3 shows an embodiment of the injection device 32 in a basic position. The injection device comprises a metering piston 34, a valve slider 35 and a path recorder system 36 for monitoring the position of the metering piston to effect volumetric injection. The metering piston 34 is designed as a differential piston. The metering piston 34 is installed in a metering chamber 37, on which the passage to the accumulator 5 is opened, on the other hand, the passage 140 is connected. The passage is connected to the chamber 141 and the chamber 142, the length of the passage is short designed to keep the dynamic pressure difference small and prevent the automatic opening of the valve slider. It is advantageous. The blind bore 143 is opened to the chamber 141. In the chamber 141, a spring 154 is supported, which is supported on the valve slider 35 on the one hand and supported on the other hand in the chamber 141, to maintain the valve slider in a basic state. The valve slider 35 is formed with a valve seat 38 ^I and two control edges 38 ^II and 38 ^IV . The valve slider 35 is installed in the housing and together with the housing forms a gab seal 38 ^III , 38 ^V , 39. The valve slider 35 has a piston 144 protruding into the blind bore. When the nozzle needle is stuck, the return passage for fuel with a mask 30 branches to the injection passage so that the fuel is discharged into a pressureless space through the mask 30 so that the fuel Will not be injected.

The preliminary control valve is designed as a switchover valve and should play a substantial role between both switching positions to prevent the second accumulator 108 from emptying when the valve piston is stuck.

In addition, a unit is provided which is not illustrated for supplying each cylinder with lubrication means dependent on the load and / or crankshaft angle.

The function of the injection system is described as follows. In the basic position of the valve slider 35, fuel enters the metering chamber 37 from the accumulator 5 via the control edge 38 ^IV of the valve slider 35. The metering piston 34, on which the accumulator pressure is applied on both sides, moves to the end position determined by the area difference. The metering piston and valve slider 35 block the passage of the fuel from the accumulator 5 to the fuel nozzle 31, preventing the accumulator 5 from emptying, for example, when the nozzle needle of the fuel nozzle is stuck. do. In addition, the fuel flows through the passage 140 to the chambers 141 and 142 so that the same pressure exists in the chamber. This has the advantage that the valve slider operates only by control commands.

The preliminary control valve 14 is opened and closed by the control module 22 such that control oil exits the accumulator 108 and reaches the control piston 39 of the valve slider 35 to displace the piston. As the control oil completely fills between the valve seat 38 ^I and the control edge 38 ^II , (38 ^IV ) is closed before (38 ^II ) is opened. When the control edge 38 ^II is opened, the metering chamber 37 is connected with the fuel nozzle 31. The displacement of the valve slider 35 causes the piston 144 to be displaced into the blind bore 143, the movement of the valve slider being initiated with braking by the control edge 147 in a particularly advantageous manner. Reach with damping.

The rear face of the metering piston is connected to the accumulator 5, the pressure in the accumulator being the volume of the fuel multiplied by the area of the metering piston and the stroke distance of the metering piston to obtain a rotational speed set by the rotational speed regulator. The fuel is transferred to the fuel nozzle, i.e., volumetric fuel metering is performed until The displacement of the metering piston 34 is measured by the measuring system 36, and the control module 22 switches the preliminary control valve 14 to close the first control edge 38 ^II in the valve slider 35. And then open the control edge 38 ^IV . In this way, the fuel supplied to the fuel nozzle 31 is interrupted.

The valve slider 35 is associated with each fuel nozzle 31 so that the fuel nozzles for each cylinder can be controlled independently of one another, for example simple injection, singlely interrupted injection or multiply. All injection possibilities, such as intermittent injection, injection times of varying lengths in individual fuel nozzles, can also be carried out cyclically or stochastic permutation, respectively (see FIG. 2). The fuel nozzle is preferably provided such that the nozzle needle is attenuated. To this end, a chamber 148 and a passage 149 for connecting the chamber to a leakage line are formed in the housing. An end of the nozzle needle is provided with a piston 150 which faces away from the valve seat and protrudes into the chamber. The single valve slider 35 can operate all fuel nozzles of the engine cylinder at low cost. In the system described above, conventional heavy oil and sediment oil can be used in such engines.

As shown in FIG. 4, the gas exchange system 12 includes a device 51 having a separation piston 56 and a control piston 52 associated with the gas exchange valve 53, respectively. . The separation piston 56 separates the hydraulic system (working oil) from the control oil circuit and dampens the movement of the exhaust valve 53 in the region of the end position. The preliminary control valve 14 removes the hydraulic fluid from the accumulator 8 in the open and close position and causes the control piston 52 to move to one of two movable positions, where the gas exchange valve 53 is a valve air spring. air spring; 61) to the "closed" position. Drive piston 54 presses the valve shaft and flows oil into piping line 55, which in turn displaces piston 56 and moves it to an approximately predetermined initial position. The piston 56 in turn sends hydraulic fluid through the control piston 52 to a line 57 which leads to a collection tank. The oil lost due to leakage losses and continuous ventilation (not shown) until the gas exchange valve 53 is operated the next time is the line 58 and the non-return valve. It is refilled through valve 59, thereby moving piston 56 to a fully defined initial position.

When the preliminary control valve 14 is in another position, the hydraulic fluid can be discharged through the preliminary control valve 14 by the compression spring 60 moving the control piston 52 to another position, and the piston 56 The side of the piston to the accumulator 8 via the control piston 52, where the side of the piston faces away from the piping line 58. The hydraulic fluid entering the piston 56, the piping line and the drive piston 54 opens the gas exchange valve against the gas pressure and valve air spring 61 still present in the cylinder of the engine.

When the gas exchange valve is used as an exhaust valve, the drive piston 54 is a stepped piston because a large force must be present at the beginning of this movement in order to be able to open against the pressure still remaining in the cylinder. (step piston; 65, 66). At the beginning of the movement path of the valve movement, the large piston 65 operates in its wider cross-section to generate the force necessary to open the gas exchange valve 53. Further processing of the valve operation is sufficient to allow the gas exchange valve 53 to perform a full stroke even with a smaller force. The large piston 65 moves towards an abutment 67, where the movement is attenuated by a short damping action, not shown, before reaching the abutment. By arranging the pistons 65 and 65 as described above, the amount of hydraulic oil coming out of the second accumulator 8 is minimized.

The measuring system 71 comprises a stepped cone 72 and a redundant sensor 78 for sensing the movement of the gas exchange valve and generating a measuring signal sent to the control module 22. The control system recognizes that the movement of the gas exchange valve meets expectations and prevents the next fuel injection in the case of an incorrect opening and closing and an inappropriate pressure, for example in the cylinder concerned. This ensures that for example an engine with n cylinders can be operated with n-1 cylinders. As shown in FIG. 7, the stepped cone 72 has a first conical section 79, a cylindrical section 76 adjacent to the first conical section, and a continuous second conical section 77, wherein The first and second cone angles are made as large as possible to ensure the maximum measurement range of the sensor. The first section 79 measures the opening action of the valve and enables a damping action which is determined while the valve is opening. The second section measures the closing action of the valve and enables a damping action which is determined while the valve is closed. It is also possible for smaller engines with shorter stroke strokes and smaller tolerances to be designed as simple cones in which the entire valve stroke is formed by only one conical section.

If for some reason the gas exchange valve 53 is not completely closed, the stepped pistons 65 and 66 will not be in their initial position, ie there will be too much oil in the line 55. . When the piston 56 pushes out the entire amount of oil at this time, the gas exchange valve 53 with the air spring 61 is pressed very strongly toward the valve guide sleeve, leading to damage to the engine.

To prevent this, a plate spring is provided which absorbs the kinetic energy of the gas exchange valve through compression, thereby preventing breakage of the engine. Unillustrated continuous ventilation and unavoidable leakage loss of the system between the piping line 55 and the drive piston 54 may occur after a certain number of minutes if there is a problem with hydraulic control during the "open" state of the gas exchange valve. Ensure that the valve closes automatically.

The risk of contamination of the hydraulic circuit is largely eliminated by the piston 56 separating the hydraulic system from the lubricating oil circuit since the hydraulic oil circuit filled with finely filtered oil does not need to be opened when the cylinder is not filled. . Valves 73, 74, 75, which allow the gas exchange system of each individual cylinder to be isolated from the engine, are replilenishing in front of the check valve 59 in the line between the second accumulator 8 and the control piston 52. ) And the flow-off line 57 so that the control device of the exhaust valve can be repaired while the engine is running.

As shown in FIG. 5, the control device can have two central units 21, one acting as a main unit and the other as a spare unit. The central unit 21 is connected to each control module 22 and sensors 25, 26 by a bus system. Sensors 25 and 26 are installed at specific angular positions of the crankshaft and the signals of all sensors are validated by logic. If an error is detected, a defective sensor can also be detected. Each control module 22 controls the injection system, gas exchange system and starting air valve 28 with the aid of data from the central unit 21. When inlet control 27, water injection or subsequent piston lubrication is provided, it is likewise controlled by the control module 22. In normal operation, the two buses shown in FIG. 5 share a role in the sense that one is used only for communication between modules and the other is used only for transmission of the current position and rotational speed of the crankshaft. In emergency operation, ie if one of the two buses fails, the engine can also be operated with low precision using the remaining one normal bus.

In the event of disturbance or failure within the electronic control system, for example, two angle sensors 25 may be damaged such that the central unit 21 no longer accurately or completely generates the required electrical signals. If not, an emergency system is required to maintain the operating capability of the large diesel engine. As shown in FIG. 5, in the internal combustion engine according to the invention, a pulse control shaft 91 for generating an electrical control signal for the preliminary control valve 14 in an attuned manner to the operating cycle of the engine. ) May be provided. The pulse control shaft 91 is a separate unit mechanically coupled to the crankshaft of the combustion engine.

6 shows another embodiment of the injection device. The compression pump 7, the accumulator 8 and the preliminary control valve 14 form a hydraulic system for the control of the injection and the action of the gas exchange.

The injection device comprises a metering piston 81, a valve slider 82, a control valve 83 and a path recording system 84 for measuring the position of the metering piston to effect volumetric injection. The metering piston is designed as a pressure amplifier. Compression pump 86 sends the fuel to metering piston 81 and control valve 83 blocks the passage to the injection nozzle.

In the default position the valve slider is closed, the pressure intensifier is in the initial position and the control valve is closed. Fuel delivered to the pressure increaser by the compression pump maintains the pressure increaser in its initial position. When the control slider is operated by the hydraulic system with the preliminary control valve 14a, pressurized oil flows into the pressure increaser to displace the pressure increaser. The pressure increaser increases the pressure in the fuel to the injection pressure. It will be appreciated that each cylinder may be provided with one or more preliminary control valves 14 or control valves 83.

The reciprocating piston combustor comprises an injection system for volumetric injection for each cylinder, one or more fuel supply compression pumps, at least one compression pump for supplying control media, one fuel each connected to the pump and gas exchange system, An accumulator for control oil, a hydraulic fluid, a control device having one or more angle sensors and a central unit, and a plurality of electronic control modules for controlling the starting air supply, injection, gas exchange and central lubrication.

The combustion engine is fully electronically controlled in normal operation.

In the two-stroke diesel engine according to the present invention, the design of combustion engines more economical than conventional engines, less fuel consumption, less pollution, low temperature rise of parts, simple maintenance and more reliable operation using electronic control system are realized. Can be.

Claims (19)

In a reciprocating piston combustion engine having a plurality of cylinders, specifically a two-stroke diesel engine, An injection system 11 for injecting fuel in a volumetric manner by means of a metering piston for each cylinder, Gas exchange system 12 for each cylinder, A plurality of pumps (3, 7, 107, 15) for supplying fuel and control medium, Accumulators 5, 8, 108 for one or more fuel and control media in communication with the pump and the injection system and / or the gas exchange system, A hydraulic system having said injection and gas exchange control member 14, Lubricator for each cylinder, One or more angle sensors 25, 26, and A control device 21 having a plurality of electronic control modules 92 for adjusting the fuel supply and gas exchange and for controlling the starting air supply control. Reciprocating piston combustion engine comprising a. In a reciprocating piston combustion engine having a plurality of cylinders, specifically a two-stroke diesel engine, An injection system 11 for injecting fuel in a volumetric manner by means of a metering piston for each cylinder, Gas exchange system 12 for each cylinder, A plurality of pumps (3, 7, 107, 15) for supplying fuel and control media, Accumulators 5, 8, 108 for one or more fuel and control media in communication with the pump and the injection system and / or the gas exchange system, A hydraulic system having a member 14 for controlling said injection and gas exchange, Lubricator for each cylinder, One or more angle sensors 25, 26, and Control device provided with the said central unit 21 for combustion engines Including; Automatic electronic control module 22 for each cylinder in such a way that the fuel nozzles can be operated individually for fuel supply, the gas exchange can be regulated, and the starting air supply can be controlled. Containing Reciprocating piston combustion engine. The method according to claim 1 or 2, A reciprocating piston combustion engine provided with a high pressure pump (4) having a suction restrictor control device for fuel. The method according to any one of claims 1 to 3, Reciprocating piston combustion engine wherein the pump (7) is connected to the crankshaft. The method according to any one of claims 1 to 4, A reciprocating piston combustion engine having an auxiliary drive for the pump (7). The method according to any one of claims 1 to 5, A reciprocating piston combustion engine provided with an accumulator (5, 8, 108) with or without fittings. The method according to any one of claims 1 to 6, A reciprocating piston combustion engine provided with a safety valve (16) for the accumulator (5) for fuel to maintain a maximum pressure set inside the accumulator. The method according to any one of claims 1 to 7, Valves 40, 41, 42; 73, 74, 75 for isolating the injection system 11 and gas exchange valve 13 of each individual cylinder from the engine are provided in each of the fuel line and the control medium line, A reciprocating piston combustion engine wherein the valves can be operated manually. The method according to any one of claims 1 to 8, A reciprocating piston combustion engine provided with a differential piston 34 or step piston 81 for metering the fuel. The method according to any one of claims 1 to 9, A reciprocating piston combustion engine having a measurement system for regulating the movement of said metering pistons (34, 81). The method according to any one of claims 1 to 10, A reciprocating piston combustion engine provided with a central lubrication device with pressure regulation. The method according to any one of claims 1 to 11, Reciprocating piston combustion engines provided with a clocked central lubrication system. The method according to any one of claims 1 to 12, A reciprocating piston combustion engine provided with a valve for starting air which can be electrically controlled for each cylinder. The method according to any one of claims 1 to 13, And a pulse control shaft (23) connected to the crankshaft to control the combustion engine in the event of a problem with the control device. The method according to any one of claims 1 to 14, A plurality of angle sensors 25 are installed on the shaft to generate a signal indicative of the crankshaft angle, and a plurality of reference sensors having control logic to monitor the signal indicative of the crankshaft angle. A reciprocating piston combustion engine provided with 26). The method according to any one of claims 1 to 15, A reciprocating piston combustion engine in which a control module associated with each cylinder is connected to the control device in a signal transmission manner. The method according to any one of claims 1 to 16, A reciprocating piston combustion engine having a measuring system for adjusting the movement of the gas exchange valve. The method according to any one of claims 1 to 17, A reciprocating piston combustion engine provided with an intake control device 27 for each cylinder. The method according to any one of claims 1 to 18, A reciprocating piston combustion engine, in which a filter for control oil (13) is provided in front of the pumps (7, 107).