JP2011256867A - Large engine with cylinder lubrication device and method for lubricating large engine cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved lubrication device and method which can determine an ideal time of introducing lubricating oil into a cylinder and lubricate the inner wall surface of a cylinder of a large engine.SOLUTION: The large engine has a plurality of cylinders 20. A piston 25 is arranged inside the cylinder 20. A lubrication device of the cylinder can supply lubricating oil to the cylinder wall 22 through two lubrication points 7 and 17, and has lubricating oil lines 8 and 18 for feeding lubricating oil to the lubrication points 7 and 17. Cut-off elements 5 and 15 which are controlled by a central unit 50 are arranged to the lubricating oil lines 8 and 18, and when the cut-off elements 5 and 15 are open, lubricating oil can be supplied to the lubrication points 7 and 17. The cut-off elements 5 and 15 can be opened at an arbitrary predetermined point of time according to the state of operation of the large engine. The period that the cut-off elements 5 and 15 are open is adjusted so that the amount of lubricating oil to be carried to the lubrication points 7 and 17 can be set arbitrarily according to the state of operation of the large engine.

Description

  The present invention relates to a large engine having a cylinder lubricating device and a method for lubricating a running surface of a cylinder wall of a cylinder of the large engine.

  The large engine is a reciprocating piston engine, and is particularly used as a large diesel engine that operates at a low speed, for example, in the hull. Large engines are often used as a drive assembly for ships or as a drive assembly in fixed operation, for example, to drive a large generator for generating electrical energy. In this regard, the engine operates for a substantial period of time in a continuous mode of operation that generally places high demands on operational safety and availability. For this reason, in particular, long intervals between maintenance, limited wear, economical handling of fuel, operating materials are central criteria for the operator for machine operation. Among other things, the operating behavior of the pistons of such large-bore low-speed large engines is decisive for the operating costs directly due to the interval between maintenance, availability, and the consumption of lubricating oil, and hence for economic efficiency. This is a major factor. For this reason, the complex problem of lubrication of large diesel engines is more important.

  In large diesel engines, but not limited to this, piston lubrication occurs via a lubrication device disposed within the reciprocating piston or within the cylinder wall, thereby providing lubrication. Oil is applied to the running surface of the cylinder wall to reduce friction between the piston and the running surface, thereby reducing wear on the running surface and the piston ring. For example, for current modern engines, for example for Wartsila PTA engines, running surface wear is less than 0.05 mm for a 1000 hour operating period. The amount of lubricating oil delivered to such an engine is about 1.3 kg / kWh or less and should be further reduced as much as possible at least for cost reasons and wear should be minimized at the same time.

  With regard to both the special design of the current lubrication system and the method of lubrication, a very different solution is known as a lubrication system for lubricating the running surface. For example, a lubricating device is known in which lubricating oil is applied on a piston that travels through a plurality of lubricating openings arranged in the circumferential direction of a cylinder wall and past the lubricating openings. Is dispersed in the circumferential direction and the axial direction by the piston ring. Lubricating oil is not applied in large amounts on the running surface of the cylinder wall, but is selectively applied more or less between the piston rings on the side surface of the piston.

  In this regard, different methods are known. For example, a lubrication system is proposed in US Pat. No. 6,057,049, in which the lubricating oil is pressurized at high pressure by a spray nozzle disposed in the cylinder wall to scavenges present in the combustion space substantially tangentially to the cylinder wall. Once injected, the lubricant is sprayed onto very small particles. Through this, the sprayed lubricating oil is finely distributed within the scavenging as a result of the swirl resulting from the centrifugal force that assists the scavenging, and thus also the finely distributed lubricating oil, particles Are blown against the running surface of the cylinder wall.

  The plurality of lubricating oil nozzles are preferably provided in the movable piston in different ways, in which case the term lubricating oil nozzle can be easily applied with lubricating oil over the entire height of the running surface at any position. It can include units with check valves and / or simple outlet openings as possible.

  The type of lubricating oil, the manner in which the lubricating oil is applied to the running surface of the cylinder wall, its metering, and the point at which the lubricating oil is introduced into the cylinder of a large engine have an essential effect on the quality of the lubrication.

  The amount of lubricant applied on the running surface per unit time per unit surface can depend on many different parameters during operation of the large engine. For example, the chemical composition of the fuel used, in particular its sulfur content, plays an important role. Along with the lubrication of the cylinder, i.e. the friction between the piston and the cylinder running surface, more particularly the wear between the piston ring and the running surface of the cylinder wall, the lubricating oil is inter alia in the combustion space of the engine. It also works for aggressive acid neutralization, particularly sulfur-containing acids, that occur during the combustion process. For this reason, different types of lubricating oils can be used depending on the fuel used, and different types of lubricating oils, among other things, have different neutralization capabilities, so-called lubricating oil BN values are neutralized. It is an indicator of ability. For example, lubricating oils with high BN values have a greater neutralizing effect on acids, so for high sulfur content fuels, higher BN values than for low sulfur content fuels. It is advantageous to use the lubricating oil that it has.

  However, it often happens that the same type of lubricant must be used for different quality fuels. For example, higher or lower acid content in the combustion products can be compensated by a corresponding increase or decrease in the amount of lubricating oil used in such cases.

  Further problems associated with metering the amount of lubricant to be applied are due to timely and / or local deviations in the thickness of the lubricant film, particularly in the thickness of the lubricant film in the engine operating state of a reciprocating piston. expressed.

  In essence, the required amount of lubricating oil is also subject to different operating parameters such as, for example, speed, combustion temperature, engine temperature, cooling capacity for cooling the engine, load and many other operating parameters. Dependent. For example, for high loads at a given speed, different amounts of lubricating oil must be applied to the running surface of the cylinder than for low loads at the same speed.

  Furthermore, the condition of the engine itself can also affect the amount of lubricating oil. For example, the amount of lubricating oil to be used varies greatly depending on the wear state of the cylinder running surface, the piston ring, the piston wear state, and the like. For example, to some extent an increased amount of friction is desired during the leveling phase of a cylinder and / or a new piston ring with a new unfamiliar cylinder running surface, and thus the opposing runs, i.e. for example piston rings, The piston ring groove and the running surface can be scraped and are therefore ideally synchronized with each other. This is achieved, inter alia, by using different amounts of lubricating oil during the leveling phase of the cylinder than for cylinders that have already been operated in a considerable operating time. For this reason, the amount of lubricating oil, in particular the amount of lubricating oil for each cylinder, can often be set separately in a period having a plurality of cylinders.

  The running surface of the cylinder will also wear both circumferentially and longitudinally depending on the number of hours of operation performed. The same applies to the piston ring and the piston itself, for example.

  Thus, the amount of lubricating oil for the reciprocating piston engine is not only set according to the number of hours of operation to be performed, but the amount of lubricating oil is determined in a timely manner and depending on the requirements of the cylinder. It should be metered differently locally in one and the same cylinder at different locations on the wall running surface.

  For this reason, preferably individually controllable lubricating oil nozzles are provided in different areas in the running surface of the cylinder or in the moving piston, the amount of lubricating oil being locally and temporally flexible depending on the requirements It has been known for many years to be able to change.

  Different methods are known for determining the amount of lubricant to be introduced by a particular lubricant nozzle at a particular time. In the simple case, the amount of lubricant depends on the operating conditions of the engine reciprocating in a controlled manner, for example load, speed, taking into account the quality of the fuel and the current lubricant used if possible. In this case as well, the wear state between the opposing runs can be taken into account on the basis of the already performed operating time.

  For example, those skilled in the art differ in the field of so-called fluid lubrication, in the field of inferior lubrication, and in the field of mixed lubrication. In the case of fluid lubrication when a lubricating oil film having such a thickness is formed between the opposing runs, i.e., between the running surface of the cylinder wall and the piston ring of the piston, the surfaces of the opposing runs do not contact each other. Thus, they are well separated from each other by the lubricating oil film. Different boundaries are represented by so-called mixed friction or mixed lubrication. In the case of mixed friction, the lubricating oil film between the opposing runs is at least partially very thin so that the opposing runs are in direct contact with each other. In this case, there is a risk of scuffing, and eventually piston seizure occurs. Between these two boundary cases, a so-called low-grade lubrication is possible. In the state of low lubrication, the lubricating oil film is so thick that the opposing runs are no longer in contact. However, the amount of lubricating oil between opposing runs is not sufficient to cause fluid lubrication. In the past, both low-level lubrication and mixed lubrication conditions were avoided as much as possible. This means that the thickness of the lubricating oil film is preferably selected so that fluid lubrication is set between opposing runs.

  Operation in the field of fluid lubrication inevitably results in a correspondingly large consumption of lubricating oil. This, on the other hand, was surprisingly shown not only to be very uneconomical, but also to lack of lubricating oil, as well as excessive lubricating oil can cause opposing running damage in the cylinder.

  The problem is that the characteristic size of the lubricating oil film is determined by the sensor in the operating state, and following evaluation of the sensor signal by the adjustment unit, the state parameter of the lubricating oil film on the running surface is optimized and the lubricating oil supply source With the corresponding metric, the lubricating oil film thickness was preferably solved locally, for the first time, in a satisfactory manner. Corresponding devices and related methods have already been described in detail in US Pat.

  While this innovative method ideally solves the problem of determining the required amount of lubricant that needs to be transported to a specific location on the cylinder's running surface, it is still possible to inject lubricant into the cylinder. There is always a problem in determining the ideal point in time for.

  In this regard, the ideal point in time depends on many parameters, in particular the different operating conditions in which the engine is operating. Many of the parameters that play a role in this respect are the same as described above in relation to the exact lubricant film thickness. In particular, the exact point of time necessarily depends mainly on the different lubrication methods mentioned above. For example, the point in time for the injection of lubricating oil necessarily results in the lubricating oil being injected, for example, directly into the scavenging or overrunning piston, for example directly onto the piston ring package of the piston. Sensitively depends on what should be done.

  Obviously, the point of time of the lubricant injection is notably the static and dynamic geometric parameters of the large engine, in particular the position of the piston between the bottom dead center region and the top dead center region relative to the location of the lubricant nozzle. Also depends on. This is to ensure ideal injection of lubricant into the cylinder, the position, sensor piston position X is known relative to the cylinder's longitudinal axis at the time of lubricant injection as accurately as possible It means you have to.

  So far, the position X of each piston between the bottom dead center region and the top dead center region is determined in the cylinder, and according to different methods, the current large engine crank angle of each piston of the engine is, for example, It was judged from a single central crank angle measuring device by a chain drive directly connected to the lubricating oil pump by a shaft.

  Generally speaking, the current crank angle of large engines is still being measured in the operating state, and from this central crank angle measuring device all positions of the pistons in the cylinder are calculated. The point of injection of the lubricating oil into the relevant cylinder is then calculated from the position X of the piston in the cylinder calculated from the measured crank angle.

  However, the methods that have been used up to now are not practical for the calculated position of the piston in the cylinder, especially in certain operating conditions such as maximum load or high or maximum speed or other extreme operating conditions. Has the decisive drawback of being associated with large unacceptable errors.

  However, also under normal operating conditions, these errors can result in the lubricant not being introduced into the cylinder at an ideal time, resulting in premature wear, reducing service intervals and hence increasing costs. In the worst case, it causes considerable damage to the cylinder components.

  The reasons for this erroneous position determination are, inter alia, the elasticity of the engine, its movable and stationary parts, and the large vibrations and movement of the crankshaft in the torsional direction.

  In particular, this has the effect that the crank angle measured at a certain position or component of a large engine cannot be accurately correlated in a well-defined manner with the current position of a certain piston in the cylinder, but at best with an error that cannot be calculated. Thus, the accuracy includes an error that easily expands to a plurality of crank angles depending on the state, for example, the load and rotation speed of a large engine and other arbitrary operating parameters. The lubricant can then be injected at a completely wrong time. In the worst case, it is also not used for lubrication, for example, it is not injected onto the piston wall during the compression stroke, it is injected below the piston, and thus does not even contribute to lubrication during at least that stroke of the piston.

  To increase this problem, the error for each cylinder of a large engine, which is not always always a large number of cylinders, for example 6, 8, 10, 12, 14 are preferably arranged in series, has different errors. This is because other amplitudes, such as vibration, torsion, etc., as described above, and other possible frequency spectra have different effects depending on the position and / or section of the crankshaft where the cylinder is located. It is.

  Furthermore, for the fine adjustment of the engine and / or the fine adjustment of the compression for each cylinder, the fact that the top dead center area of the piston is adjusted individually, for example by means of a specific support disk and / or separation support, this is the so-called "Compression shim" means that each cylinder is individually provided at a suitable location for mounting a piston, piston rod, crosshead or other piston mounting element, so that compression within the cylinder is achieved. Optimized. This leads to the fact that even if the position of the piston cylinder is accurately correlated to the crank angle measured at a certain position, the position of the cylinder is still not accurate. This is because the calculation of the position of each piston needs to be performed with different generally unknown correlation factors due to different adjustments of the individual pistons by the compression shims.

  However, since these correction factors are not known, the error typically increases during the currently performed calculation of the position of the piston in the cylinder.

  Furthermore, electronically regulated lubricant systems do not necessarily prevent excessive amounts of lubricant from reaching the running surface. This is because, in addition to a predetermined amount of lubricating oil, it is not considered whether the large engine is operating at maximum load.

  The metering of the lubricating oil is typically defined by a lubricating oil system as shown in Patent Document 3, for example. The lubricating oil system includes a pump nozzle unit for supplying a predetermined amount of lubricating oil to each of the lubricating points on the running surface of the cylinder. The pump is designed as a reciprocating piston pump. Lubricating oil present in the pump is transported to the one or at most two lubrication points by the stroke of the working piston. The working piston is operated by a hydraulic medium. The stroke is started when a hydraulic line connected to the working piston is opened by the switching valve and a hydraulic medium is applied to the working piston.

  The switching valve is switched depending on the operating state of the large engine, such as the position and / or location of the crankshaft, load, speed. The operating state is detected by the sensor unit in the large engine and converted into an electronic signal introduced into the adjustment unit. The regulating unit monitors whether the electrical signal corresponds to an operating condition that requires the supply of lubricating oil and can send a corresponding output signal to the switching valve.

  The fact that the lubrication point or pair of lubrication points can be supplied with a single predetermined amount of lubricating oil determined by the size of the pump space is disadvantageous for this construction. The predetermined amount must be very large so that sufficient lubricating oil is guaranteed even during operation at maximum load of the large engine.

  However, when a large engine is operated with a partial load, the amount of lubricating oil supplied to the lubrication point is too large to reach the fluid lubrication field described above.

  Patent Document 4 also proposes providing each valve with a valve whose opening time can be adjusted individually for each lubrication point. For this, a central pressure reservoir for lubricating oil is used, from which lubricating oil can be supplied to all lubricating points of all cylinders of a large engine. Although it is possible to set the amount of lubricating oil by precisely adjusting the opening time using this lubrication system, a significant number of operating parameters need to be monitored. This adjustment requirement requires a significant increase in labor in addition to increased costs when operational safety needs to be ensured over time.

  In addition, a pump is provided for transporting into the pressure reservoir. If the amount of lubricating oil in the pressure reservoir is not fully required, for example when the large engine is operating at a partial load, the valve connected to the pressure reservoir will allow the lubricating oil to be conveyed into the circuit. Opened to be able to.

  The amount of lubricating oil delivered to the lubricating point is thus determined solely by the opening time of the switching valve located in the lubricating oil line between the pressure reservoir and the lubricating point.

  In Patent Document 5, it is proposed that the lubricating oil is sent from a single pump in a common lubricating oil supply source to all the cylinders by a lubricating oil passage connected to an injector belonging to each cylinder. Each lubrication point is therefore its own injector. Each injector is arranged with an electromagnetic valve to independently supply lubricating oil to each injector position. This means that according to this process, the amount of lubricating oil and the time point for conveying the lubricating oil can be set arbitrarily.

  From Patent Document 6, it is also known to foresee a small lubricating oil reservoir or accumulator arranged in a lubricating oil supply path to each cylinder. The supply of lubricating oil to the lubrication location in the cylinder is controlled by a single common solenoid valve. The electromagnetic valve is disposed between the accumulator and the lubricating oil distribution valve. The lubricant distribution valve can open all the passages to all the lubrication locations of a particular cylinder. This means that according to this solution, the amount of lubricating oil supplied to the cylinder and the time of lubrication can be controlled. However, the amount of lubricating oil supplied to each lubricating location is not further affected due to the fact that no closing element is arranged downstream of the lubricating oil distribution valve. Therefore, the control of the amount of lubricating oil and the point of lubrication is not performed independently of each other.

  However, the disadvantage is that the amount of lubricating oil supplied to each cylinder cannot be changed when the opening time of the switching valve, for example, the electromagnetic valve of Patent Document 5, remains the same. This means that the amount of lubricating oil can only be changed by the opening time of the switching valve. However, the volumetric flow rate through the switching valve per hour is determined fixedly.

  Furthermore, it is indicated as a drawback that the viscosity of the lubricating oil needs to be monitored. This is because the lubricant must follow a long path from the central pressure reservoir to the lubrication point. In the middle of the lubrication point, the temperature experienced by the lubricating oil line changes greatly, which has a considerable influence on the viscosity of the lubricating oil. In particular, it should be avoided that the lubricant solidifies in the individual lubricant lines, thereby clogging the lines. To help with this problem, the viscosity and / or temperature must pass through a cold region or at least be provided in a particularly long lubricating oil line.

  For this reason, a further lubricating oil system has been developed in US Pat. No. 6,057,075, where each cylinder is associated with its own lubricating module. The lubrication module includes a lubricant pump that sporadically conveys, whereby the lubricant is metered and conveyed in pulses to the lubricant nozzle. The pump is formed as a reciprocating piston pump having a plurality of feed pistons. The feed piston is movably arranged in the pump space. The pump space determines the volume of lubricating oil that can be transported to each lubrication point with each stroke.

  Each lubrication point is associated with a feed piston. As the pump strokes, the volume of lubricating oil in the pump space is transferred to the corresponding lubrication point. This means that a constant volume of lubricant reaches the lubrication point with each stroke. Stroke frequency, which means the number of feed strokes within a certain time interval, but can be varied. The pump is operated by servo oil. The feed piston is moved by the actuating piston to perform a stroke. The working piston is collided with servo oil. The switching valve controls the movement of the working piston. The switching valve is controlled according to the operating parameter of the engine. This means that the number of strokes per unit time can be changed via an adjustment unit that controls the switching valve.

WO00 / 28194 brochure EP 1 505 270 A1 EP 2 177 720 A1 EP 1 426 571 B1 EP 1 582 706 A2 EP 0 368 430 EP 1 767 751 A1

  The object of the present invention is therefore to avoid the above-mentioned problems and, through its use, determine the ideal point in time for the introduction of lubricating oil into the cylinder, the running surface of the cylinder of a large engine It is an object to provide an improved lubrication apparatus and lubrication method.

  The subject that achieves the above objectives in terms of equipment and process engineering aspects is characterized by the features of the independent claims of each category.

  Each dependent claim relates to a particularly advantageous embodiment of the invention.

  The large engine includes at least a first and a second cylinder, each having a bore (B) and a longitudinal axis (A), and a piston movable back and forth along the running surface in each cylinder. Is done. A lubrication device for cylinder lubrication is provided, the lubrication device includes at least two lubrication points, and lubrication oil can be applied to the traveling surface via the lubrication points, and the lubrication device includes a lubrication oil supply source A lubricating oil line for delivering lubricating oil from to the lubricating point. The lubricating device includes, for each cylinder, a pump, a distributor, at least two lubricating oil lines, and at least one blocking element disposed in each of the lubricating oil lines. Lubricating oil can be pumped into the distributor and from the distributor to the lubrication point when the blocking element is in the open position. The position of the shut-off element can be adjusted by a central unit according to the operating state of the large engine, and the shut-off element is supplied with lubricating oil to the corresponding lubricating point and the lubricating oil is supplied to the corresponding cylinder It can be opened at any given time depending on the operating state of the large engine. During the period in which the blocking element is opened according to the operating state of the large engine, the time point is set so that the amount of lubricating oil conveyed to the lubrication point can be arbitrarily set according to the operating state of the large engine. Can be adjusted independently.

  For example, the rotational speed and / or load and / or cylinder temperature and / or combustion space temperature and / or other current operating parameters may be determined as operating parameters.

  In particular, the working material used, for example the properties of the fuel used, in particular the sulfur content of the fuel used and / or the type of lubricant used and / or the BN value of the lubricant, Since they also play a central role in the ideal time of injection and / or the ideal duration of lubricant injection, they can also be used effectively for the calculation of setpoints and need If it is effective or effective, it can be monitored during operation by a suitable measuring device.

  Naturally, it is understood that the above-mentioned operating conditions of a reciprocating piston engine that can be taken into account to determine the ideal point in time and / or time interval settings for lubricant injection. The enumeration of parameters and / or data can be used effectively, but is not final and can also include additional relevant parameters and data for determining setpoints.

  The shut-off element can be maintained in the open position at least during each third rotation of the large engine so that a supply of lubricating oil to the lubrication point occurs. In particular, lubrication can always occur at the same piston position or at the same time so that the lubrication process is determined very accurately.

  The blocking element is maintained in the open position at a frequency of at least once every ten seconds to at least once every minute so that lubricating oil can be supplied to the lubrication point. Thereby, particularly simple control of the lubrication process can be achieved. In particular, in the case of emergency lubrication, it is necessary to ensure a periodic supply of lubricating oil to the lubrication point. A supply cycle of every 0.5 seconds is particularly effective.

  In particular, the operating state can be determined by measuring the position and / or torque and / or rotational speed and / or crank angle of the cylinder of a large engine.

  The distributor can be designed as a lube advisory rail reservoir connected to all lube lines for each cylinder. This can ensure that the same pressure exists in each of the lubricating oil lines.

  The lubrication points can be arranged at different positions on the cylinder wall with respect to the axial direction defined by the longitudinal axis (A) of the cylinder. Lubricating oil is not only injected at multiple points distributed along the cylinder circumferential surface, but also at different axial positions, so the lubricating oil is evenly distributed over a large surface of the running surface Can be done. Lubricant supply can occur simultaneously at this point, which means that all shut-off elements are open at the same time. However, it is also possible to carry out the lubricant injection at different times. This means, for example, that lubrication precedes piston movement.

  The pump can in particular be configured as a piston pump having a plurality of pistons. The feed piston is preferably driven by a camshaft. In particular, the camshaft can be driven by an electric motor. The rotation speed of the camshaft, which means the number of feed strokes per hour, is variable within a predetermined range of rotation speeds by an electric motor. The feed piston can also be connected to the working piston according to a further variant, in which case the working piston can be moved by means of hydraulic pressure so that a feed stroke can be carried out.

  The feed piston conveys lubricating oil to the distributor. When the feed piston of the rotary piston pump performs successive feed strokes, the pressure deviation of the distributor can be reduced, which is particularly noticeable when the camshaft cams are arranged at different angles. It is.

  The fluid pressure means can be lubricating oil supplied from an additional lubricating oil source. In particular, the lubricating oil supply source can be pressurized at a higher pressure than the lubricating oil supply source used for lubrication. This lubricating oil supply can be pressurized at pressures up to 50 bar. Lubrication for the lubrication device is provided in particular by a lubricating oil source that is pressurized at pressures up to 30 bar. Use of two lube oil sources, which means two lube oil reservoirs or lube containers at different pressures, which allows the pump to operate with lube oil. Here, there is no need to provide a seal between the driving fluid and the working fluid, that is, lubricating oil for lubrication. Here, the installation of the sealing member in the pump is negligible, which results in a cost-effective production of the pump and simplification during operation and maintenance.

  The pressure of the lubricating oil source for the lubrication device is preferably less than the pressure of the lubricating oil source for actuation of the working piston of the pump.

  The invention further relates to a method for lubricating a running surface of a cylinder wall of a cylinder of a large engine, the cylinder having a bore (B) and a longitudinal axis (A), in which a piston follows the running surface. Thus, a lubrication device for cylinder lubrication is foreseen, and the lubrication device includes at least two lubrication points provided in the cylinder wall, and the lubricating oil is passed through the lubrication points. The lubricating oil is applied to the running surface and reaches the lubricating point from a lubricating oil supply source. The pump conveys lubricating oil from the lubricating oil source into the distributor, the distributor having at least two lubricating oils when there is a fluid conveying connection between the distributor and the corresponding lubricating point. Conveying the lubricating oil to the lubrication point on the running surface of the cylinder wall via a line and at least one blocking element respectively disposed on each of the lubricating oil lines, the blocking element being in the open position The lubricating oil is transported from the lubricating oil line, and the position of the shut-off element is adjusted according to the operating state of the large engine, and the shut-off element supplies the lubricating oil to the corresponding lubricating point Is maintained in the open position at any given time for an arbitrary period, depending on the operating state of the large engine, the large motor has at least first and second cylinders, Serial lubricating device comprises at least one pump for each of the cylinders.

  Preferably, the setting of the blocking element occurs according to the load of the large engine. Here, the lubricant supply can be precisely adapted to the requirements.

  The setting of the shut-off element occurs depending on the position and / or torque and / or rotational speed and / or crank angle of the piston in the cylinder of the large engine.

  According to a particularly simple variant, the conveyance of the lubricating oil to the running surface of the cylinder wall is interrupted when the pressure in the cylinder space is greater than the feed pressure of the lubricating oil. Here, it can be ensured that the lubricant does not reach the combustion chamber of the cylinder when the piston is in the vicinity of the top dead center. Here, the presence of the lubricating oil in the combustion space during the combustion process can lead to combustion of the lubricating oil leading to undesirable deposits and exhaust gases, which can be prevented.

  The presence of lubricating oil can be measured at the distributor, for example by a pressure sensor, and transmitted to the central unit. The central unit checks whether the pressure is within a predetermined pressure range defined by an upper threshold and a lower threshold, in which case the injection is extended and / or blocked when the upper threshold of the pressure range is exceeded. The element is forced to remain in the open position and / or the safety valve is activated and / or the pump is turned off and an alarm is triggered when the pressure drops below that pressure. Long-term drops below that pressure, in particular, indicate a leak in the lubrication system, which needs to be checked as quickly as possible to prevent damage due to lack of lubricating oil.

The figure of the cylinder of the 2-stroke large diesel engine which has the conventional lubrication apparatus. 1 is a diagram of a cylinder of a two-stroke large diesel engine having a lubrication device according to the present invention. The graph of the pressure distribution in the combustion space according to the crank angle with the lubricating oil pressure by a 1st modification. The graph of the pressure distribution in the combustion space according to the crank angle with the lubricating oil pressure by a 2nd modification. FIG. 2 is an injection characteristic diagram of the system according to FIG. 1. The injection characteristic figure by this invention. FIG. 6A is a pressure distribution diagram of FIG.

  The invention is described in detail below with reference to the schematic drawing.

  A cylinder of a two-stroke large diesel engine with a common lubrication device is shown schematically in part in FIG. Each cylinder of a two-stroke large diesel engine is associated with a self-contained lubrication module 100. The lubrication module includes an intermittent conveyance type lubricating oil pump 100, whereby the lubricating oil is measured and conveyed to the lubricating oil nozzles 107 and 117 in a pulsed manner. The pump 101 is configured as a reciprocating piston pump having a plurality of feed pistons 138. The feed piston 138 is movably disposed in the pump space 136. The pump space 136 determines the volume of lubricating oil that can be transferred to each lubrication point with each stroke. A feed piston 138 is associated with each lubrication point. As the pump 101 strokes, the volume of lubricating oil present in the corresponding pump space 136 is transferred to the corresponding lubrication point. This means that for each stroke, a certain fixed volume of lubricating oil reaches the lubricating point, that is, each of the lubricating oil nozzles 107 and 117.

  The pump spaces 136 of the pump 101 all have the same size so that the same amount of lubricating oil can be conveyed to each lubrication point.

  The stroke period, i.e. the number of feed strokes within a unit time, can be varied. The pump is operated by servo oil. Feed piston 138 is moved by actuating piston 133 to perform a stroke. The working piston 133 is collided by servo oil. The switching valve 132 is controlled according to the engine operating parameter. This means that the number of strokes per hour can be changed via the adjustment unit 150 that controls the switching valve 132.

  Since the pump 101 is operated with servo oil, a seal on the drive side of the working piston space 135 is required with respect to the feed piston side of the working space 134. Lubricating oil is discharged by the common rail reservoir 111 to the feed piston side of the working piston space 134 to which the lubricating oil is supplied, for example. The lubricating oil line 112 extends from the common rail reservoir 111 to the working piston 134. This construction is similar for each cylinder, and in this example, the additional lubricating oil line 162 leads to the illustrated lubricating module 200 on the side not close to the additional cylinder of the two-stroke large diesel engine.

  Lubricating oil discharged into the working piston space 134 reaches the working space 136 through the respective openings 139. The opening 139 is connected to the working piston space 134 as long as the working piston is in the working piston space 134, which means that the pump stroke has not yet begun. As soon as the working piston is hit by the servo oil, the working piston space 135 starts to move against the resistance of the return means 135. Each of the openings 139 is closed by a feed piston 138 and the lubricating oil in the pump space 136 is compressed. When the pressure of the lubricating oil in the pump space reaches the required pressure, the opening valve 163 is opened and the lubricating oil reaches the lubricating oil lines 108, 118 reaching the corresponding lubricating oil nozzles 107, 117. When the pump spaces all have the same volume, the same amount of lubricating oil reaches each lubrication point for each feed stroke.

  Therefore, this amount of lubricating oil cannot be changed. When a two-stroke large diesel engine operates, for example, with partial load, in practice only a small portion of the amount of lubricating oil supplied will be required. Matching with the amount of lubricating oil currently required is therefore not possible with conventional lubrication modules.

  In order to operate the prior art lubrication module, two further circuits are required, namely on the one hand represented by the common rail reservoir 111 and on the other hand by the servo oil supply vessels 130, 131. Servo oil circuit is required.

  A cylinder of a two-stroke large diesel engine with a lubrication device 10 according to the invention is shown schematically in part in FIG. The two-stroke large diesel engine of FIG. 2 has a plurality of cylinders 20 and only one cylinder 20 is schematically shown for clarity. The cylinder 20 includes a cylinder wall 22 that defines an internal space 23 of the cylinder 20 in a circumferential direction in a manner known per se. The piston 25 is disposed in the cylinder 20 so as to be movable back and forth along the traveling surface 21 of the cylinder wall 22 with respect to the axial direction A of the cylinder 20. In the special example of FIG. 1, the running surface 21 is provided on a surface region layer 24 applied to the surface of the cylinder wall 22 by, for example, thermal spraying. At least one lubrication point 7, 17 is arranged in the cylinder wall 22, in particular the lubricant nozzles 26, 46 are arranged in the cylinder wall 22 and are lubricated by the pump 1 in a manner known per se. Supplied and, therefore, in the operating state, a lubricant film can be applied on the running surface of the cylinder wall 22.

  According to the invention, the lubrication points 7, 17 are connected to the pump 1 via the lubricating oil lines 8, 18. Each lubricating oil line includes a blocking element 5, 15. The lubricating oil line is part of the distributor 3 which can also be configured as a common rail reservoir. The pump 1 conveys the lubricating oil from the lubricating oil supply source 30 to the lubricating points 7 and 17 via the distributor 3.

  The pump 1 can have a similar type of configuration as already shown in FIG. However, in contrast to the prior art, the pump is operated with lubricating oil rather than servo oil. This means that the lubrication source 30 supplies lubricating oil at a pressure of about 20 bar. The operating piston 33 of the pump 1 is operated by the lubricating oil conveyed from the lubricating oil supply source 31 having a higher pressure than the lubricating oil supply source 30. In general, the pressure in the lubricant source 31 is between 40 and 50 bar, in particular about 50 bar.

  Lubricating oil discharged into the working piston space 34 reaches the feed space 36 through the respective openings 39. The opening 39 is connected to the working piston space 3 as long as the working piston is present in the working piston space 34. This means that the stroke of the pump 1 has not yet started. As soon as the working piston is struck by the lubricating oil in the working piston space 35, it is moved against the resistance of the return means 37. Each opening 39 is closed by a feed piston 38, and the lubricating oil in the feed space 36 is compressed. Since the feed space 36 is in fluid communication with the distributor 3, the lubricating oil in the distributor and / or lubricating oil lines 8, 18 is also compressed.

  When the feed stroke is complete, the lubricating oil reaches the required pressure in the lubricating oil lines 8,18. A pressure sensor in the distributor 3 can monitor whether pressure is present within a predetermined range required to ensure lubrication. This range is generally in the range of 20 to 50 bar.

  Lubricating oil is therefore supplied to the lubricating oil lines 8, 18 so that it can be added to the running surface 21 of the cylinder 20 at a desired time. The desired point in time is determined by the central unit which sends a signal for opening the corresponding blocking element 5, 15 via the signal transmission lines 42, 43. The point of lubrication can therefore be determined completely freely by the central unit.

  Naturally, the closing time of the blocking elements 5, 15 can also be determined arbitrarily by the central unit 50. Here, the amount of lubricating oil required for this particular lubricating cycle can be set accurately.

  The measuring device 40 is schematically shown in FIG. 2, whereby the characteristic value for the operating state of the two-stroke large diesel engine is detected. The measuring device 40 generates an electronic signal that is characteristic to the characteristic value and transmits the signal to the central unit 50 via a signal transmission line 41 so as to be used for controlling the lubrication system. The signal is evaluated in the central unit 50. If the evaluation determines that lubrication is necessary, the shut-off elements 5, 15 are actuated, i.e. the shut-off elements 5, 15 are shut off from the central unit so that they are open or closed for the passage of lubricating oil. Signals are transmitted to the elements 5 and 15 via signal transmission lines 42 and 43. The signal can also be used for the control of the pump 1. This can be used for pumps where the feed flow rate can be varied, for example rotary pumps such as centrifugal pumps or impeller pumps. For example, the number of revolutions of the motor driving the pump can be changed so that the volumetric flow rate conveyed by the pump can change per time. This possibility is also given to the rotary piston pump. Such rotary piston pumps typically include a plurality of pistons that are moved by a camshaft driven by an electric motor. As the camshaft speed increases, the number of piston strokes per unit time increases, thus changing the volumetric flow rate delivered by the pump. Inevitably, a pump with a single feed piston can also be used, in which case the feed piston can be moved by a camshaft or by hydraulic pressure. In this example, the switching cycle of the switching valve 32 can be changed. In this case, the signal is transmitted from the central unit 50 to the switching valve 32 via the signal transmission line 44. The switching valve 32 is in particular formed as a magnetic valve. The switching valve 32 can take two positions. In the first position, the connection between the working piston 33 and the lubricating oil supply 30 can be guided so that the lubricating oil returns from the feed piston space 34 where the working piston 33 is present to the lubricating oil supply 30. To be opened. The connection line between the lubricant supply 30 and the feed space 36 is opened so that the lubricant can flow into the feed space 36.

  The actuating piston 33 is brought to its upper limit position by return means 37, which in this example is a spring, and is now ready to perform a feed stroke. When the switching valve 32 receives a signal to perform a feed stroke from the central unit 50, it switches so that the connection to the lubricant supply 31 is open. Lubrication at high pressure is discharged from the lubricating oil supply source 31 into the working piston space 35 and the working piston 33 performs a feed stroke, i.e., the lubricating oil is drawn into the distributor 3 from the feed space by the feed piston 38. The Furthermore, the working piston need not be separated from the feed space by a seal. A seal on the drive side of the working piston space 33 against the feed piston side of the working piston space 34 is therefore not required.

  The shut-off elements 5 and 15 are each opened for a specific period based on the measurement values of the measuring device 40, so that lubricating oil is applied onto the running surface 31. The period during which each blocking element 5, 15 is maintained in the open position is individually adapted and depends on the measured value detected by the measuring device 40.

  Inevitably, multiple measuring devices can be provided to determine different characteristics of a large engine.

  The adjustment of the pump supply current needs to be coupled to the adjustment of the opening time of the shut-off element.

  The method for the operation of the lubricating device according to the invention comprises the following steps. That is, the set value for the duration and / or time point of the lubricant discharge onto the running surface 21 of the cylinder 20 is determined according to different operating parameters of the large engine. In particular, the rotational speed and / or load and / or cylinder temperature and / or crank angle and / or different operating parameters and / or the composition of the fuel used and / or the lubricating oil used and / or other operations used. It depends on the material. With their help, the duration and / or current point in time of the lubricant discharge into the cylinder is different from the relevant current operating parameter B and / or special absolute operating parameter B and / or use for large engines. Can be determined in consideration of the components of the fuel used, in particular the fuel used or the lubricating oil used, and / or other relevant factors.

  The point of time and / or duration of the lubricant discharge is optimized in this respect during operation of the large engine to the set point. For example, the measured value can be measured by a position sensor, which corresponds to the position X of the piston and / or the time distribution of the position X, and the measured value specifically includes adjusting means together with the data processing system. It can be transported to the central unit 50. In this respect, preferably a plurality of position sensors spaced apart from each other in the axial direction A are provided for determining the position X of the piston. Such a position sensor can also be used for measuring the crank angle.

  The position sensor is, for example, especially when it is a passive acoustic emission sensor, via the calculation of the propagation time difference of the signals detected by the position sensor and / or taking into account the known technique of the correction signal, i.e. Through a search for the corresponding correlation function of the signal, it is possible to determine the position X of the piston, especially depending on time.

  It should be understood that other types of position sensors can actually be used effectively instead of acoustic emission sensors, in particular by means of pressure sensors, the pressure of the gas and / or inside the cylinder 20. The time dependence of the gas pressure can be measured and / or the pressure characteristic value characteristically related to the position X of the piston in the cylinder can be measured.

  However, other types of sensors, such as inductive position sensors and electrical position sensors, can be used effectively. Depending on the sensor used, the piston can also include marking means, such as magnetic marking means, so that the piston contour can be better recognized by the position sensor. .

  In addition, a further measuring device is provided here, not shown here, which can determine different operating parameters B, for example cylinder temperature and load of the large engine, among others, and send them further to the central unit 50. Can be done.

  A particularly simple variant produces results when a shielded organ with a spring mounted is provided at the lubrication point, which means that the lubricating oil is introduced into the cylinder's internal space when the pressure in the cylinder is within a certain range. It only allows access.

  It is also possible to set the pressure of the lubricating oil so that it is between the maximum pressure and the minimum pressure existing in the combustion space. The pressure of the combustion space is greater than the pressure of the lubricating oil at least during the last phase of the compression stroke, at the time of ignition of the mixture and at the beginning of the expansion phase, so that no lubricating oil can enter the combustion space. Only when the pressure in the combustion space falls below the pressure of the lubricating oil during the expansion phase, the supply of fresh air or the first phase of the compression stroke, the lubricating oil can be discharged onto the running surface of the cylinder. Alternatively, lubricating oil can be discharged when the piston passes the lubrication point during the compression stroke. This means that the lubrication point opens into a cylinder space filled with scavenging air present at the corresponding scavenging pressure. In this regard, the scavenging pressure is typically typically greater than the ambient pressure, with a margin of approximately 3 bar. Thus, a connection exists between the location of the lubrication point and the piston. When the piston is located above the lubrication point, i.e., when the piston ring packet is above the lubrication point, scavenging air is generally present at the shielding element, but the pressure in the combustion space, i.e., between the piston package and the outlet valve. The pressure in the cylinder space in between is remarkably high. 3 and 4 are graphs showing the pressure in the combustion space according to the crank angle. The crank angle is indicated on the x-axis and the pressure in the combustion space is indicated on the y-axis. Lubricating oil pressure distribution 60 is shown by the lines running horizontally in FIG. In this case, the pressure of the lubricating oil is constant.

  Therefore, when the lubrication point is in the area covered by the piston ring package during the compression stroke, this is because the scavenging side pressure is significantly lower than the combustion side pressure in the cylinder space, so the piston is near bottom dead center The lubricating oil reaches the inside of the cylinder space when positioned at the position.

  FIG. 4 shows a case where the pressure distribution 60 of the lubricating oil changes according to the crank angle. This modification occurs, for example, due to adjustment of the supply amount of the pump.

  The lubricating device according to the present invention or the method according to the present invention not only significantly increases the life of the piston ring and the cylinder running surface, but also reduces the consumption of lubricating oil at the same time, and can significantly extend the maintenance interval. Furthermore, the lubrication device according to the present invention requires a circuit that is very simple and therefore not subject to errors, significantly reducing the possibility of anomalies, for example for a system such as that shown in US Pat.

FIG. 5 shows the distribution of discharge by a lubricating oil nozzle having the lubricating module 101 according to FIG. The graph shown in FIG. 5 shows the pressure distribution shown on the y-axis according to the time shown on the x-axis. This measurement is made with the engine stopped and the engine is a type RT-flex96C-B engine with a discharge volume of 310 mm ³ per lubricant nozzle.

  The graph shows a large increase or decrease, where the pressure distribution is recorded immediately downstream of the pump outlet, ie outlet valve 163.

  FIG. 6 shows the distribution of discharge in the lubricating oils 7 and 17 by the lubricating device 10 according to FIG. The graph shown in FIG. 6 shows the volumetric flow rate shown on the y-axis as a function of time shown on the x-axis. As can be concluded from the volumetric flow distribution found by the simulation, there is a small pressure fluctuation, as shown in connection with the diagram according to FIG. 6b for the pressure distribution in the distributors 3, 8, 18 according to FIG. Accordingly, FIG. 6B shows the pressure distribution at the lubrication point as a function of time.

  Naturally, the present invention is not limited to the particular embodiment illustrated, but is limited to the results of each lubrication system according to the present invention.

Claims (15)

A large engine including at least a first cylinder and a second cylinder, wherein each of the first cylinder and the second cylinder has a bore and a longitudinal axis, and can reciprocate back and forth along the traveling surface. A piston is provided, and a lubrication device for cylinder lubrication is provided, the lubrication device including at least two lubrication points, through which the lubricating oil can be applied to the traveling surface, the lubrication device Includes a lubricating oil line that sends lubricating oil from a lubricating oil source to the lubricating point;
The lubrication device includes a pump for each cylinder, a distributor, at least two lubricating oil lines, and at least one blocking element disposed in each of the lubricating oil lines,
Lubricating oil can be pumped into the distributor and from the distributor to the lubrication point when the shut-off element is in the open position;
The position of the shut-off element can be adjusted by a central unit according to the operating state of the large engine, and the shut-off element is supplied with lubricating oil to the corresponding lubricating point and the lubricating oil is supplied to the corresponding cylinder Can be opened at any given time depending on the operating state of the large engine.
During the period in which the blocking element is opened according to the operating state of the large engine, the time point is set so that the amount of lubricating oil conveyed to the lubrication point can be arbitrarily set according to the operating state of the large engine. Large engine that can be adjusted independently from.   2. The large engine according to claim 1, wherein the blocking element is held in an open position so that the supply of lubricating oil occurs once during each rotation of the large engine and at least during each third rotation.   3. The large engine according to claim 1, wherein the blocking element is held in an open position so that lubricating oil can be supplied at a frequency of at least once every ten seconds to at least once every minute.   The said operation state is determined by the measured value of the position and / or torque and / or rotation speed and / or crank angle of the piston in the said cylinder of the said large sized engine. Large engine described in 1.   The large engine according to any one of claims 1 to 4, wherein the distributor is designed as a common rail reservoir for lubricating oil connected to all lubricating oil lines for each cylinder.   The large-sized engine according to any one of claims 1 to 5, wherein the lubrication points are arranged at different positions on the cylinder wall with respect to an axial direction defined by a longitudinal axis of the cylinder.   The large engine according to any one of claims 1 to 6, wherein the pump is a piston pump having a plurality of feed pistons.   The large engine according to claim 7, wherein the feed piston can be driven by a camshaft.   The large engine according to claim 7 or 8, wherein the feed piston conveys lubricating oil to the distributor.   The large engine according to any one of claims 1 to 9, wherein a pressure sensor is disposed in the distributor. A method of lubricating a running surface of a cylinder wall of a cylinder of a large engine, the cylinder having a bore and a longitudinal axis, in which a piston is reciprocated back and forth along the running surface, A lubrication device for cylinder lubrication is foreseen, and the lubrication device includes at least two lubrication points provided in the cylinder wall, through which lubrication oil is applied to the running surface, Reaching the lubrication point from a lubrication oil supply, the pump conveys the lubrication oil from the lubrication oil supply into the distributor, and the distributor conveys fluid between the distributor and the corresponding lubrication point When there is a connection, the cylinder wall via at least two lubricating oil lines and at least one blocking element respectively disposed in each of the lubricating oil lines Conveys the lubricating oil into the lubricating points in the running surface, so the lubricating oil is conveyed from the lubricating oil line when the blocking element is in the open position,
The position of the shut-off element is adjusted according to the operating state of the large engine, and the shut-off element is an aspect in which the supply of lubricating oil to the corresponding lubrication point occurs, and is arbitrarily set according to the operating state of the large engine. Held in the open position at any given point in time,
The large motor has at least first and second cylinders, and the lubrication device includes at least one pump for each of the cylinders.   The method of claim 11, wherein the setting of the blocking element occurs in response to a load on the large engine.   The method according to claim 11 or 12, wherein the setting of the shut-off element occurs depending on the position and / or torque and / or speed and / or crank angle of the piston in the cylinder of the large engine.   The conveyance of the lubricating oil to the said running surface of the said cylinder wall is interrupted when the pressure in a cylinder space is higher than the supply pressure of lubricating oil, Any one of Claims 11-13. Method.   The lubricating oil pressure is measured in the distributor and transmitted to a central unit, which checks whether the central unit is within a predetermined pressure range defined by an upper threshold and a lower threshold; When the upper limit of the pressure range is exceeded, the injection is extended and / or the shut-off element is forced open and / or the safety valve is activated and / or the pump is turned off and a warning is issued for the pressure The method of claim 14, wherein the method is initiated upon descent.

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