Cylinder Lubrication System

Abstract

To provide a cylinder oil-filling system which can efficiently fill a piston reciprocating in a cylinder with a lubricant.SOLUTION: A cylinder oil-filling system being one embodiment of this invention comprises: an oil syringe for filling a piston reciprocating in a cylinder of a marine internal combustion engine with a lubricant through an oil-filling rod arranged at the cylinder; an electromagnetic valve for accumulating the lubricant in the oil syringe in a closed state, and making the oil syringe fill the piston with the lubricant in an open state; and a control device. The control device derives an oil-filling rate of the lubricant according to an engine load, decides an oil-filling frequency and the oil-filling timing of the lubricant to a piston upper side part of the piston and a skirt part at the derived oil-filling rate, and controls the opening / closing drive of the electromagnetic valve so that the oil syringe fills the piston with the lubricant at the decided oil-filling frequency and the oil-filling timing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cylinder lubrication system. [Background technology]

[0002] Conventionally, engines (marine internal combustion engines) installed on ships are provided with multiple cylinders that house pistons that can reciprocate freely, and the reciprocating motion of the pistons inside each of these multiple cylinders is converted into the rotational motion of a crank, causing the crankshaft to rotate. Generally, in marine internal combustion engines, each time the pistons reciprocate inside the cylinders, combustion gas in the combustion chamber is compressed, fuel is burned, etc. The pistons are housed in the cylinders with their crowns facing the combustion chambers, and reciprocate inside the cylinders while being subjected to the pressure inside the combustion chambers (hereinafter referred to as intra-cylinder pressure).

[0003] The outer periphery of such a piston is provided with a plurality of piston rings aligned in the direction of the piston's reciprocating motion. These piston rings are in sliding contact with the inner periphery of the cylinder while applying an appropriate surface pressure, and slide along the inner periphery of the cylinder as the piston reciprocates. The piston also has a skirt portion (piston skirt) below the lowest piston ring among the plurality of piston rings. Generally, due to its structure, a piston may tilt while reciprocating inside the cylinder. This tilting of the piston is regulated by the sliding contact between the inner periphery of the cylinder and the skirt portion.

[0004] As described above, lubricating oil is supplied (lubricated) between the piston reciprocating inside the cylinder and the inner circumferential surface of the cylinder to ensure the piston's ability to slide against the inner circumferential surface of the cylinder. For example, Patent Document 1 describes an oil-filling method in which a first oil-filling period for filling the cylinder while the piston is rising is adjusted based on the crank angle and engine speed of a two-stroke engine, and if the engine speed drops and oil cannot be filled below the lowest piston ring within the first oil-filling period, oil is supplementarily filled below the lowermost piston ring within a second oil-filling period after the first oil-filling period. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-83228 Summary of the Invention [Problem to be solved by the invention]

[0006] Generally, the higher the internal pressure applied to the crown of a cylinder during reciprocating motion, the more stable the piston's posture and the less likely it is to tilt, whereas the lower the internal pressure, the more unstable the posture and the more likely it is to tilt. Therefore, in order to ensure the slidability of the piston along the inner circumferential surface of the cylinder, it is necessary to supply lubricating oil so that an oil film is formed between the inner circumferential surface of the cylinder and the piston ring, and also to supply lubricating oil so that an oil film is formed between the inner circumferential surface of the cylinder and the skirt when the skirt slides along the inner circumferential surface of the cylinder as the piston tilts.

[0007] However, in the oil injection method described in Patent Document 1, the period and timing for injecting lubricating oil into the piston in the cylinder are controlled according to the engine speed. Therefore, even if the piston is difficult to tilt due to an increase in the pressure inside the cylinder, there is a possibility that lubricating oil may be injecting wastefully into the skirt portion, making it difficult to efficiently inject lubricating oil into the piston in the cylinder.

[0008] In other words, regardless of the engine speed, the in-cylinder pressure of a marine internal combustion engine can increase or decrease as the load on the marine internal combustion engine (hereinafter referred to as engine load) increases or decreases due to the influence of sea conditions on a ship while sailing. For example, even if the engine speed decreases, if the engine load increases due to sea conditions, the in-cylinder pressure increases and the piston becomes less likely to tilt within the cylinder. With the oil injection method described in Patent Document 1 mentioned above, even if the piston is less likely to tilt as described above (i.e., contact between the inner circumferential surface of the cylinder and the skirt portion is less likely to occur), lubricating oil is wastedly injected into the skirt portion due to a decrease in engine speed.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a cylinder lubrication system that can efficiently inject lubricating oil into a piston that reciprocates inside a cylinder. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, a cylinder lubrication system according to the present invention comprises: an oil dispenser that dispenses lubricating oil through an oil dispenser rod provided in a cylinder to a piston that reciprocates inside the cylinder of a marine internal combustion engine; a solenoid valve that causes the oil dispenser to accumulate the lubricating oil when in a closed state and causes the oil dispenser to dispense the lubricating oil to the piston when in an open state; and a control device that derives an oil dispense rate of the lubricating oil in accordance with a load on the marine internal combustion engine, determines the frequency and timing of dispensing the lubricating oil to each of an upper piston portion and a skirt portion of the piston at the derived oil dispense rate, and controls the opening and closing drive of the solenoid valve so that the oil dispenser dispenses the lubricating oil at the determined frequency and timing.

[0011] In addition, the cylinder lubrication system of the present invention is characterized in that, in the above invention, the control device determines the frequency and timing of feeding the lubricating oil to the upper part of the piston and the frequency and timing of feeding the lubricating oil to the skirt part so that the rate of feeding the lubricating oil to the skirt part is a constant ratio to the rate of feeding the lubricating oil to the upper part of the piston.

[0012] Furthermore, in the cylinder lubrication system according to the present invention, in the above invention, the control device sets the lubricating oil feed rate when the load of the marine internal combustion engine is 100% as a reference oil feed rate, and derives the lubricating oil feed rate according to the load of the marine internal combustion engine based on the set reference oil feed rate.

[0013] In addition, the cylinder lubrication system of the present invention is characterized in that, in the above invention, it includes an input unit that inputs a designated value to the control device to changeably designate the standard lubrication rate, and the control device sets the standard lubrication rate based on the input designated value.

[0014] In addition, the cylinder lubrication system of the present invention is characterized in that, in the above invention, it includes an input unit that inputs permission information to the control device to permit the lubrication of the lubricating oil to the skirt portion, and the control device permits the lubrication of the lubricating oil to the skirt portion based on the input permission information.

[0015] In addition, the cylinder lubrication system of the present invention is characterized in that, in the above invention, the control device determines, for each cycle included in a fixed cycle period in which one cycle corresponds to one reciprocating motion of the piston, whether to inject the lubricating oil into the piston, and, if injecting the lubricating oil, whether to oil the upper part of the piston or the skirt part.

[0016] Furthermore, in the cylinder lubrication system according to the present invention, in the above invention, the control device controls the opening and closing drive of the solenoid valve based on the crank angle of the marine internal combustion engine so that the oil dispenser dispenses the lubricating oil to the upper part of the piston when the piston is rising or to the skirt part of the piston when the piston is falling. [Effects of the Invention]

[0017] According to the present invention, it is possible to efficiently supply lubricating oil to a piston that reciprocates inside a cylinder. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a cylinder lubrication system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing an example of the arrangement of oiling rods in an embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing an example of a first data table used for oil supply control for the upper portion of the piston in the embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing an example of a second data table used for oil supply control for the skirt portion in the embodiment of the present invention. [Figure 5] FIG. 5 is a schematic diagram showing an example of oiling the piston upper portion 5a in the embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram showing an example of oiling a piston skirt in an embodiment of the present invention. [Figure 7] FIG. 7 is a flowchart showing an example of a processing flow of oil supply control by the cylinder oil supply system according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] A preferred embodiment of the cylinder lubrication system according to the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to this embodiment. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from those in reality. The drawings may also include parts whose dimensional relationships and ratios differ from one another. In addition, the same components are designated by the same reference numerals in each drawing.

[0020] (Configuration of cylinder lubrication system) FIG. 1 is a schematic diagram showing an example of the configuration of a cylinder lubrication system according to an embodiment of the present invention. This cylinder lubrication system 10 injects lubricating oil into a piston 5 reciprocating inside a cylinder 1 of a marine internal combustion engine to ensure the slidability of the piston 5 relative to the inner circumferential surface 2a of the cylinder 1. Although not specifically shown, the marine internal combustion engine is a propulsion engine mounted on a ship that rotates a propeller for propelling the ship via a propeller shaft, and is, for example, a two-stroke diesel engine such as a uniflow scavenging / exhausting crosshead diesel engine. Cylinder 1 is an example of multiple cylinders provided in the marine internal combustion engine. The cylinder lubrication system 10 injects lubricating oil into each of these multiple cylinders in the same manner as in the case of cylinder 1 shown in FIG. 1.

[0021] More specifically, as shown in Figure 1, the cylinder 1 is a cylindrical structure (cylinder) made up of a cylinder liner 2 and a cylinder cover 3. The cylinder 1 accommodates a piston 5 inside the cylindrical cylinder liner 2 so that it can reciprocate freely. The cylinder cover 3 is fixed to the top of the cylinder liner 2. The cylinder liner 2, cylinder cover 3, and piston 5 form (compartmentalize) a combustion chamber 4 of the marine internal combustion engine inside the cylinder 1. The cylinder cover 3 is also provided with an exhaust valve 9. The exhaust valve 9 is a valve that opens and closes an exhaust port that leads to the combustion chamber 4 inside the cylinder 1 in an openable and closable manner.

[0022] 1, the piston 5 includes a piston body 6 and three piston rings 7a, 7b, and 7c. In this embodiment, the piston 5 includes three piston rings 7a, 7b, and 7c, but the present invention is not limited to this, and the piston 5 may include a plurality of (two or more) piston rings.

[0023] As shown in FIG. 1 , the piston body 6 is composed of a crown portion 6a, a skirt portion 6b, and an intermediate portion 6c, and is formed to have a circular shape when viewed from the central axis direction of the cylinder liner 2. Piston rings 7a, 7b, and 7c are each fitted into annular grooves provided on the outer periphery of the intermediate portion 6c, which is located between the crown portion 6a and the skirt portion 6b of the piston body 6, and are configured to slide against the inner circumferential surface 2a of the cylinder liner 2 while applying an appropriate surface pressure. The crown portion 6a is a portion of the piston body 6 above the uppermost piston ring 7a (opposite the skirt portion 6b) and is also referred to as a piston crown. The piston body 6 is accommodated in the cylinder liner 2 of the cylinder 1 so that the crown portion 6a faces the combustion chamber 4 and is capable of reciprocating freely. The skirt portion 6b is a portion of the piston body 6 below the lowermost piston ring 7c (opposite the crown portion 6a) and is also referred to as a piston skirt.

[0024] 1, one end of a piston rod 8 is rotatably connected to the piston body 6. Although not shown, the other end of the piston rod 8 is rotatably connected to a crosshead, and one end of a connecting rod is rotatably connected to the crosshead. The other end of the connecting rod is rotatably connected to the crank of the crankshaft.

[0025] In a marine internal combustion engine, as shown in FIG. 1, a piston 5 reciprocates between top dead center Ct and bottom dead center Cb in the cylinder 1 while piston rings 7a, 7b, and 7c slide against the inner circumferential surface 2a of the cylinder 1, receiving the internal pressure of the combustion chamber 4 at its crown 6a. Each time the piston 5 reciprocates inside the cylinder 1, the following events occur sequentially inside the cylinder 1: introduction of combustion gas into the combustion chamber 4, compression of the combustion gas, combustion of the fuel supplied to the combustion chamber 4, and exhaust from the combustion chamber 4. This reciprocating motion of the piston 5 is converted into the rotational motion of a crank via the piston rod 8 and other components. As a result, the crankshaft rotates, which in turn rotates the propeller shaft and the propeller for propelling the ship.

[0026] Furthermore, when the piston 5 reciprocates inside the cylinder 1, the piston 5 may tilt with respect to the central axis of the cylinder 1. In this case, the skirt portion 6b comes into contact with the inner peripheral surface 2a of the cylinder liner 2, thereby suppressing tilting of the piston 5. The piston 5 returns from the tilted position to its pre-tilt position while continuing its reciprocating motion inside the cylinder 1. Note that tilting of the piston 5 tends to be less likely as the in-cylinder pressure applied to the crown portion 6a increases, and tends to occur more easily as the in-cylinder pressure applied to the crown portion 6a decreases.

[0027] On the other hand, as shown in Fig. 1, the cylinder lubrication system 10 includes an oiling rod 11, an oiler 12, a solenoid valve 13, an oil supply unit 14, an operating device 15, and a control device 16. In Fig. 1, solid arrows schematically indicate the flow and piping of lubricating oil, and dashed arrows schematically indicate electrical signal lines.

[0028] As shown in Fig. 1, the oil dosing rod 11 is provided in the cylinder liner 2 so as to be located between the top dead center Ct and the bottom dead center Cb of the reciprocating motion of the piston 5 and so as to face its oil dosing port toward the inside of the cylinder 1. The oil dosing rod 11 is also connected to a lubricator 12 through piping, allowing communication between the inside of the cylinder 1 and the lubricator 12. Note that, for the sake of convenience of explanation, one oil dosing rod 11 is shown in Fig. 1, but in the cylinder oil dosing system 10, a plurality of oil dosing rods 11 are provided in the cylinder liner 2.

[0029] FIG. 2 is a schematic diagram showing an example of the arrangement of lubricating rods in an embodiment of the present invention. FIG. 2 schematically shows a cross section of the cylinder liner 2 shown in FIG. 1. In FIG. 2, solid arrows schematically show the flow and piping of lubricating oil. As shown in FIG. 2, a plurality of lubricating rods 11 (eight in this embodiment) are arranged in the cylinder liner 2 at intervals in the circumferential direction of the cylinder liner 2. Each of these lubricating rods 11 is connected to a lubricator 12 through a pipe, allowing communication between the interior of the cylinder liner 2 and the lubricator 12. The arrangement intervals of the plurality of lubricating rods 11 may be any desired interval, but it is preferable that they are equally spaced.

[0030] The oil dispenser 12 dispenses lubricating oil to the piston 5 reciprocating inside the cylinder 1 of the marine internal combustion engine through an oil dispenser rod 11 provided in the cylinder 1. Specifically, as shown in FIG. 1 , the oil dispenser 12 is connected to each of the oil dispenser rods 11 and the oil supply unit 14 via multiple pipes so that the oil dispenser 12 can communicate with them. The oil dispenser 12 has an oil reservoir (not shown) therein that communicates with these pipes, and accumulates the lubricating oil supplied from the oil supply unit 14 in the oil reservoir. The oil dispenser 12 also has, for example, a hydraulic plunger (not shown) or the like, which pressurizes the lubricating oil accumulated in the oil reservoir. In this way, the oil dispenser 12 pressure-feeds the lubricating oil to the oil dispenser rod 11 through the pipes, and dispenses the lubricating oil from the oil dispenser rod 11 to the piston 5 in the cylinder 1. For example, the oil dispenser 12 discharges a fixed amount of lubricating oil from each of the multiple oil dispenser rods 11 per oil dispensing operation.

[0031] The solenoid valve 13 is a valve for appropriately controlling the lubricant dispenser 12 to dispense or store lubricating oil. Specifically, as shown in FIG. 1 , the solenoid valve 13 is provided in a pipe leading to the lubricant dispenser 12. This pipe is, for example, a branch pipe branching off from a pipe connecting the lubricant dispenser 12 and the lubricating unit 14. The solenoid valve 13 is driven and controlled by the control device 16, and is in either an open state, which connects the lubricant dispenser 12 and the lubricating unit 14 through the branch pipe, or a closed state, which closes the communication between the lubricant dispenser 12 and the lubricating unit 14 through the branch pipe. For example, the solenoid valve 13 is normally in a closed state, and opens when it receives an operation command control signal from the control device 16. When in the closed state, the solenoid valve 13 causes the lubricant dispenser 12 to store the lubricant supplied from the lubricating unit 14. Furthermore, when the solenoid valve 13 is in an open state, it causes the oil dispenser 12 to dispense lubricating oil to the piston 5 in the cylinder 1 .

[0032] The oil supply unit 14 supplies lubricating oil to the oil dispenser 12, which dispenses the lubricating oil to the piston 5 in the cylinder 1 through the oil dispenser rod 11. Specifically, the oil supply unit 14 is composed of a pump, a pressure regulating valve, etc., and is connected to the oil reservoir of the oil dispenser 12 through a pipe, as shown in FIG. 1 . The oil supply unit 14 is also connected to the working chamber (not shown) of the oil dispenser 12 through a branch pipe branching off from the pipe and a solenoid valve 13. When the solenoid valve 13 is closed, the oil supply unit 14 delivers lubricating oil at adjusted pressure through the pipe to the oil reservoir of the oil dispenser 12. This lubricating oil is stored in the oil reservoir of the oil dispenser 12 to be dispensed to the piston 5 in the cylinder 1. When the solenoid valve 13 is open, the oil supply unit 14 delivers lubricating oil at adjusted pressure through the branch pipe to the working chamber of the oil dispenser 12. This lubricating oil is used as hydraulic oil for causing the lubricator 12 to perform an oil supplying operation by operating a hydraulic cylinder, for example.

[0033] The operation device 15 is composed of a display device, an input device, etc., and displays various information on the display screen and transmits it to the control device in response to user input operations. For example, the operation device 15 functions as a first input unit that inputs a designated value to the control device 16 for variably specifying the reference lubricating oil feed rate. The reference lubricating oil feed rate is a reference value for the lubricating oil feed rate derived by the control device 16 during lubrication control. The designated value of the reference lubricating oil feed rate is input so that it can be changed within an allowable range based on the specifications of the marine internal combustion engine, etc. The operation device 15 also functions as a second input unit that inputs permission information to the control device 16 for permitting the feeding of lubricating oil to the skirt portion 6b of the piston 5. This permission information is input when the control device 16 is permitted to feed lubricating oil to the skirt portion 6b.

[0034] The control device 16 controls the supply of lubricating oil to the piston 5 in the cylinder 1. For example, the control device 16 is configured with a CPU, memory, etc., and has a central control unit 17 and a drive control unit 19 for executing the lubrication control, as shown in FIG. 1. The central control unit 17 also has pre-registered, by programming or the like, a first data table 18a indicating the correspondence between the lubricating oil supply rate, lubrication frequency, and lubrication timing for the piston upper portion 5a, and a second data table 18b indicating the correspondence between the lubricating oil supply rate, lubrication frequency, and lubrication timing for the skirt portion 6b of the piston 5. The piston upper portion 5a is the portion of the piston 5 above the skirt portion 6b, as shown in FIG. 1. For example, the piston upper portion 5a includes the crown portion 6a, middle portion 6c, and piston rings 7a to 7c of the piston 5.

[0035] The central control unit 17 derives the lubricating oil supply rate to the piston 5 in accordance with the load (engine load) of the marine internal combustion engine, and determines the frequency and timing of supplying lubricating oil to each of the piston upper portion 5a and the skirt portion 6b of the piston 5 at the derived lubricating oil supply rate.

[0036] In detail, the central control unit 17 sets the lubricating oil supply rate for the piston 5 when the engine load is 100% as the reference oil supply rate. For example, the central control unit 17 sets the maximum oil supply rate (hereinafter referred to as the maximum oil supply rate) among the multiple oil supply rates included in the first data table 18a as the reference oil supply rate. Alternatively, when a designated value for the reference oil supply rate is input to the control device 16 by the operation device 15, the central control unit 17 sets the reference oil supply rate based on this input designated value.

[0037] The central control unit 17 derives the lubricating oil feed rate according to the engine load, based on the reference oil feed rate set as described above. At this time, the central control unit 17 derives the oil feed rate for each operating mode of the marine internal combustion engine. For example, when the operating mode of the marine internal combustion engine is the mean effective pressure proportional mode, the central control unit 17 calculates the mean effective pressure of the marine internal combustion engine based on the engine speed detected by the engine speed detector 22 and the engine load detected by the load detector 23. The central control unit 17 calculates the ratio of the calculated mean effective pressure to the mean effective pressure when the engine load is 100%, and derives the oil feed rate according to the engine load by, for example, multiplying this ratio by the reference oil feed rate. Alternatively, when the operating mode of the marine internal combustion engine is the power proportional mode, the central control unit 17 derives the oil feed rate according to the engine load by, for example, multiplying the engine load detected by the load detector 23 by the reference oil feed rate.

[0038] The central control unit 17 also refers to the first data table 18a and the second data table 18b and determines the frequency and timing of lubricating oil supply to the piston 5 based on the derived oil supply rate. Specifically, the central control unit 17 determines the oil supply frequency and timing corresponding to the derived oil supply rate from among the oil supply frequencies and timings shown in the first data table 18a as the frequency and timing of lubricating oil supply to the piston upper portion 5a. The central control unit 17 also determines the oil supply frequency and timing corresponding to a certain percentage of the derived oil supply rate from among the oil supply frequencies and timings shown in the second data table 18b as the frequency and timing of lubricating oil supply to the skirt portion 6b. That is, the central control unit 17 determines the frequency and timing of lubricating oil supply to the piston upper portion 5a and the frequency and timing of lubricating oil supply to the skirt portion 6b so that the lubricating oil supply rate to the skirt portion 6b is a constant ratio to the lubricating oil supply rate to the piston upper portion 5a. The central control unit 17 instructs the drive control unit 19 on the lubricating oil supply frequency and lubricating timing determined as described above.

[0039] In this embodiment, when one reciprocating motion of the piston 5 inside the cylinder 1 is defined as one cycle, oil is supplied to either the piston upper portion 5a or the skirt portion 6b during one cycle of the piston 5 (hereinafter referred to as a piston cycle). Therefore, the frequency of supplying lubricating oil to the piston upper portion 5a is represented by the number of piston cycles during which lubricating oil is supplied to the piston upper portion 5a within a fixed period including multiple piston cycles (hereinafter referred to as a fixed cycle period). Similarly, the frequency of supplying lubricating oil to the skirt portion 6b is represented by the number of piston cycles during which lubricating oil is supplied to the skirt portion 6b within a fixed cycle period.

[0040] The timing of lubricating oil supply to the piston upper portion 5a is represented by specific information identifying each of the multiple piston cycles included in a certain cycle period and the crank angle corresponding to the piston upper portion 5a. Similarly, the timing of lubricating oil supply to the skirt portion 6b is represented by specific information identifying each of the piston cycles within the certain cycle period and the crank angle corresponding to the skirt portion 6b. The crank angle corresponding to the piston upper portion 5a is the crank angle of the marine internal combustion engine when the piston upper portion 5a reaches a position facing the oil filler port of the oil filler rod 11 arranged in the cylinder liner 2. The crank angle corresponding to the skirt portion 6b is the crank angle of the marine internal combustion engine when the skirt portion 6b reaches a position facing the oil filler port of the oil filler rod 11.

[0041] That is, in this embodiment, the central control unit 17 determines whether or not to inject lubricating oil into the piston 5 for each piston cycle included in a fixed cycle period, with one reciprocating motion of the piston 5 being one cycle. When injecting lubricating oil into the piston 5, the central control unit 17 determines for each piston cycle whether the piston upper portion 5a or the skirt portion 6b is to be oiled.

[0042] Furthermore, in this embodiment, the central control unit 17 may permit or prohibit the supply of lubricating oil to the skirt portion 6b, among the supply of lubricating oil to the piston 5, based on a user operation. For example, when permission information for supplying lubricating oil to the skirt portion 6b is input to the control device 16 by the operation device 15, the central control unit 17 permits the supply of lubricating oil to the skirt portion 6b based on the input permission information. In this case, the central control unit 17 permits the drive control unit 19 to supply lubricating oil to the skirt portion 6b by setting a permission flag, for example.

[0043] The drive control unit 19 controls the opening and closing drive of the solenoid valve 13 so that the lubricator 12 dispenses lubricating oil at the oil dispensing frequency and timing determined by the central control unit 17 as described above. Specifically, the drive control unit 19 controls the solenoid valve 13 to start opening the solenoid valve 13 at the oil dispensing timing instructed by the central control unit 17 for the piston upper portion 5a based on the crank angle of the marine internal combustion engine detected by the angle detector 21, and to maintain the open state for a predetermined period to drive it to close. Furthermore, the drive control unit 19 controls the solenoid valve 13 to start opening the solenoid valve 13 at the oil dispensing timing instructed by the central control unit 17 for the skirt portion 6b based on the crank angle of the marine internal combustion engine detected by the angle detector 21, and to maintain the open state for a predetermined period to drive it to close. Every time the drive control unit 19 receives instructions about the oil dispensing frequency and oil dispensing timing from the central control unit 17, the drive control unit 19 repeatedly controls the opening and closing drive of the solenoid valve 13 for a fixed cycle period, with the instructed oil dispensing frequency as an upper limit. When the drive control unit 19 has repeatedly controlled the drive of the solenoid valve 13 up to the instructed oil supply frequency, it again repeatedly controls the opening and closing drive of the solenoid valve 13 within a certain cycle period.

[0044] For example, during each piston cycle in which lubricating oil is dispensed to the piston 5 during a certain cycle period, the drive control unit 19 controls the opening and closing drive of the solenoid valve 13 based on the crank angle of the marine internal combustion engine detected by the angle detector 21 so that the lubricating oil dispenser 12 dispenses lubricating oil to either the piston upper portion 5a of the ascending piston 5 or the skirt portion 6b of the descending piston 5. In this embodiment, whether the piston 5 is ascending or descending within the cylinder 1 can be determined by the rotation angle (crank angle) of the crank that rotates in conjunction with the reciprocating motion of the piston. For example, if the crank angle when the piston 5 is located at top dead center Ct in the cylinder 1 is taken as the reference (=0 degrees), the crank angle when the piston 5 is located at bottom dead center Cb in the cylinder 1 is 180 degrees. When the piston 5 is moving from the top dead center Ct side to the bottom dead center Cb side (i.e., descending), the crank angle is between 0 degrees and 180 degrees. When the piston 5 moves from the bottom dead center Cb side to the top dead center Ct side (that is, rises), the crank angle is between 180 degrees and 360 degrees.

[0045] Furthermore, if the central control unit 17 has permitted the supply of lubricating oil to the skirt portion 6b, the drive control unit 19 controls the opening and closing drive of the solenoid valve 13 at the oil supply timing for the skirt portion 6b. On the other hand, if the central control unit 17 has not permitted the supply of lubricating oil to the skirt portion 6b, the drive control unit 19 does not control the opening and closing drive of the solenoid valve 13 at the oil supply timing for the skirt portion 6b, even if the oil supply timing for the skirt portion 6b has been instructed.

[0046] Furthermore, the drive control unit 19 controls the timing of driving the solenoid valve 13, which is in an open state, to close, based on the temperature of the lubricating oil detected by the temperature detector 24 and the pressure of the lubricating oil detected by the pressure detector 25. In this way, the drive control unit 19 can correct the time from when the solenoid valve 13 is driven to open until when it is driven to close, in accordance with changes in the state of the lubricating oil, such as the viscosity of the lubricating oil, so that the amount of lubricating oil dispensed by the lubricator 12 per oil dispense operation is constant. The time from when the solenoid valve 13 is driven to open until when it is driven to close is the time during which the solenoid valve 13 maintains its open state, and corresponds to the time during which the lubricating oil is dispensed to the piston 5 by the lubricator 12.

[0047] The angle detector 21 detects the crank angle of the marine internal combustion engine. Specifically, the angle detector 21 detects the crank angle, which changes in accordance with the reciprocating motion of the piston 5 inside the cylinder 1, continuously or intermittently over time. Each time the angle detector 21 detects a crank angle, it transmits an electrical signal indicative of the detected crank angle to the control device 16. A plurality of such angle detectors 21 are provided in the marine internal combustion engine, for example, corresponding to the plurality of cylinders of the marine internal combustion engine.

[0048] The rotation speed detector 22 is provided in the marine internal combustion engine and detects the engine rotation speed of the marine internal combustion engine. For example, the rotation speed detector 22 detects the engine rotation speed continuously or intermittently in time series, and transmits an electrical signal indicating the detected engine rotation speed to the control device 16 each time.

[0049] The load detector 23 is provided in the marine internal combustion engine and detects the engine load of the marine internal combustion engine. For example, the load detector 23 detects the engine load continuously or intermittently over time. Alternatively, the load detector 23 detects a plurality of engine loads at predetermined intervals and calculates an average value of the detected plurality of engine loads. The load detector 23 obtains the detected engine load or the average value of the calculated engine load as described above as the current engine load of the marine internal combustion engine, and transmits an electrical signal indicating the obtained engine load to the control device 16 each time.

[0050] The temperature detector 24 is provided, for example, in the lubricator 12 or the lubrication unit 14, and detects the temperature of the lubricant being dispensed to the piston 5 continuously or intermittently over time. Each time the temperature detector 24 detects the temperature of the lubricant, it sends an electrical signal indicative of the detected temperature to the control device 16. The pressure detector 25 is provided, for example, in the lubricator 12 or the lubrication unit 14, and detects the pressure of the lubricant being dispensed to the piston 5 continuously or intermittently over time. Each time the pressure detector 25 detects the pressure of the lubricant, it sends an electrical signal indicative of the detected pressure to the control device 16.

[0051] (Data Table) Next, the first data table 18a and the second data table 18b used for the oil supply control in the embodiment of the present invention will be described in detail. Fig. 3 is a schematic diagram showing an example of the first data table used for the oil supply control for the piston upper part 5a in the embodiment of the present invention. As shown in Fig. 3, the first data table 18a contains the oil supply rate Q N [g / kWh] and oil filling frequency N [times] and oil filling timing T N 1 is a data table showing the correspondence between the

[0052] Specifically, in the first data table 18a shown in FIG. 3, the oil supply frequency N is calculated based on the oil supply rate Q for the piston upper portion 5a. N The lubrication frequency N is a numerical value indicating the lubrication frequency (the lubrication frequency to the piston upper part 5a) at each of the plurality of lubrication rates registered as N. a and each value that decreases by 1 from this point. a is the maximum value among the multiple numerical values ​​registered as the oil supply frequency N in the first data table 18a.

[0053] Lubrication rate Q N is made up of a plurality of oil supply rates associated with each of the values ​​of the above-mentioned oil supply frequency N. For example, as shown in FIG. a The maximum oil supply rate Q ais associated with the maximum lubrication frequency N a Oiling frequency N minus 1 a -1 corresponds to the oiling rate Q1, and this oiling frequency N a -1 minus 1, lubrication frequency N a -2 corresponds to the oil injection rate Q2. N is calculated by the following formula (1). Lubrication rate Q N =(maximum lubrication rate Q a / Maximum lubrication frequency N a ) × Lubricating frequency N (1) In the above formula (1), for example, if the oil supply frequency N is N a -1, the oiling rate Q N The oil supply rate Q1 is calculated as follows. The oil supply frequency N is the oil supply frequency N a -2, the oiling rate Q N The oil injection rate Q2 is calculated as follows.

[0054] Such an oil injection rate Q N As shown in Figure 3, the maximum oil injection rate Q a , upper limit lubrication rate Q b , lower limit lubrication rate Q c etc. Maximum oil injection rate Q a is the maximum oil supply rate among the multiple oil supply rates registered in the first data table 18a. b is the upper limit of the oil supply rate when lubricating oil is supplied to each of the piston upper portion 5a and the skirt portion 6b. c is the minimum oil supply rate required to ensure lubrication of the piston 5 against the inner circumferential surface 2a of the cylinder 1 when supplying lubricating oil to the piston upper portion 5a.

[0055] In addition, among the oil supply frequencies N in the first data table 18a, the oil supply frequency N b is the upper limit of oil supply rate Q b is the oiling frequency corresponding to the oiling frequency N c is the lower limit oil supply rate Q c The oil supply frequency corresponds to the oil supply frequency N a / 2(maximum lubrication frequency N a The oiling rate Q is a / 2(maximum lubrication rate Q a This is the oiling frequency corresponding to the oiling rate (1 / 2 of the oiling rate).

[0056] In addition, in the first data table 18a shown in FIG. N is the timing of supplying lubricating oil to the piston upper portion 5a. More specifically, as shown in FIG. 3, the oil supply timing T N is expressed by a combination of the cycle number Y of the piston cycle, where one reciprocating motion of the piston 5 inside the cylinder 1 is one cycle, and the crank angle A corresponding to the piston upper part 5a. The cycle number Y is a number that identifies each of the multiple piston cycles included in a certain cycle period, and indicates the chronological order of these multiple piston cycles. The cycle number Y is numbered 1 to Y as shown in FIG. 3 in accordance with the chronological order of the multiple piston cycles within the certain cycle period. e Cycle number Y e is a number that identifies the last piston cycle within a given cycle period. For example, cycle number Y e is the maximum lubrication frequency N a The crank angle A corresponds to the timing of oil supply to the piston upper portion 5a for each piston cycle. That is, in the first data table 18a, "Yes" and "No" indicate whether oil is supplied to the piston upper portion 5a for each piston cycle. In a piston cycle with "Yes", oil is supplied to the piston upper portion 5a at the timing when the crank angle of the marine internal combustion engine reaches "A". In a piston cycle with "No", oil is not supplied to the piston upper portion 5a. This oil supply timing T N The number of "present" piston cycles included in the fixed cycle period is the frequency of oil supply to the piston upper part 5a performed within this fixed cycle period, and is represented by the oil supply frequency N described above.

[0057] Such oiling timing T NAs shown in Figure 3, the oil supply frequency N and the oil supply rate Q N For example, the oil injection rate Q N is the maximum oil injection rate Q a If N is the maximum lubrication frequency, N a and the oil injection timing T N is the maximum lubrication frequency N a In this case, the oil supply timing to the piston upper portion 5a is set to be 1 to Y. e The oil supply rate Q is "Yes" for all piston cycles. N If the oil supply rate Q1 is, the oil supply frequency N is a -1, and the oil injection timing T N is the oiling frequency N a In this case, the oil supply to the piston upper portion 5a is performed in the order of cycle number Y in the following pattern: "Yes" → "Yes" → "Yes" → "No" → "Yes" → "Yes" → "Yes" → "Yes", ... → "Yes". The oil supply rate Q N is the upper limit of oil supply rate Q b If N is the oil supply frequency, then N is the oil supply frequency b and the oil injection timing T N is the oiling frequency N b In this case, the oil supply to the piston upper portion 5a is performed in the order of cycle number Y in the following pattern: "Yes" → "No" → "Yes" → "Yes" → "No" → "Yes" → "Yes" → "No", ... → "Yes". The oil supply rate Q N is the lubrication rate Q a / 2, the oiling frequency N is the oiling frequency N a / 2, and the oil injection timing T N is the oiling frequency N a In this case, the oil supply to the piston upper portion 5a is performed in the order of cycle number Y in the following pattern: "Yes" → "No" → "Yes" → "No" → "Yes" → "No" → "Yes" → "No", ... "No". The oil supply rate Q N is the lower limit of the oil supply rate Q c If N is the oil supply frequency, then N is the oil supply frequency c and the oil injection timing T N is the oiling frequency N cIn this case, oil is supplied to the piston upper portion 5a in the order of cycle number Y in the following pattern: "none" → "yes" → "none" → "none" → "yes" → "none" → "none" → "yes", ... → "none".

[0058] 4 is a schematic diagram showing an example of a second data table used for oil supply control for the skirt portion in the embodiment of the present invention. As shown in FIG. 4, the second data table 18b contains the oil supply rate Q M [g / kWh] and oil filling frequency M [times] and oil filling timing T M 1 is a data table showing the correspondence between the

[0059] In detail, in the second data table 18b shown in FIG. 4, the oil supply rate Q M is the oil supply rate Q for the piston upper portion 5a. N It is registered so that it becomes a constant ratio R. That is, the oil supply rate Q M is the above-mentioned oil injection rate Q N and multiplication by a fixed rate R (Q N For example, as shown in FIG. 4, the oil supply rate Q for the piston upper portion 5a is expressed as N is the maximum oil injection rate Q a If the oil injection rate Q M is the maximum oil injection rate Q a and the constant rate R multiplied by (=Q a In this embodiment, the oil supply rate Q M (=Q a × R) is the maximum oil supply rate Q for the piston upper part 5a a These oil injection rates Q M , Q N The correspondence between the maximum oil injection rate Q a Other than oil filling rate Q N The same applies to the above-mentioned constant ratio R. It is preferable that the constant ratio R is, for example, 10% or more and 15% or less.

[0060] The oil supply frequency M is the oil supply rate Q for the skirt portion 6b. MEach value of the oil supply frequency M is equal to or less than the number of piston cycles during which oil is not supplied to the piston upper part 5a within a certain cycle period. Specifically, each value of the oil supply frequency M is equal to or less than the number of piston cycles (=Y e ) minus the frequency N of oil supply to the piston upper part 5a (Y e -N) is set as the upper limit. However, the oil supply rate Q M Q b ×R, the oil supply frequency M is zero (M=0), as shown in Fig. 4. In addition, among the oil supply frequencies M in the second data table 18b, a is the upper limit of oil supply rate Q b is the lubrication frequency corresponding to the lubrication frequency M d is the oiling rate Q a / 2, and the lubrication frequency M e is the lower limit oil supply rate Q c The oiling frequency corresponds to

[0061] In addition, in the second data table 18b shown in FIG. M is the timing of supplying lubricating oil to the skirt portion 6b. In detail, as shown in FIG. M is expressed by a combination of the cycle number Y of the piston cycle and the crank angle B corresponding to the skirt portion 6b. M The cycle number Y in the figure is the oil supply timing T N That is, the oil supply timing T M The piston cycle in the above process is the oil supply timing T NThe crank angle B corresponds to the oil supply timing for each piston cycle when oil is supplied to the skirt portion 6b. That is, in the second data table 18b, "Yes" and "No" indicate whether oil is supplied to the skirt portion 6b for each piston cycle. In a piston cycle with "Yes", oil is supplied to the skirt portion 6b at the timing when the crank angle of the marine internal combustion engine reaches "B". In a piston cycle with "No", oil is not supplied to the skirt portion 6b. This oil supply timing T M The number of "present" piston cycles included in the fixed cycle period is the frequency of oil supply to the skirt portion 6b performed within this fixed cycle period, and is represented by the oil supply frequency M described above.

[0062] Such oiling timing T M As shown in Figure 4, the oil supply frequency M and the oil supply rate Q M (i.e., Q N ×R), and is set so that oil supply to the piston upper part 5a and oil supply to the skirt part 6b do not overlap within one piston cycle. For example, the oil supply rate Q N is the maximum oil injection rate Q a If the oil injection rate Q M =Q a ×R, and the oil supply frequency M=0. In this case, the oil supply timing T M In this case, oil is applied to the skirt portion 6b in cycle numbers 1 to Y. e The oil supply rate Q N is the upper limit of oil supply rate Q b If the oil injection rate Q M =Q b × R, and the lubrication frequency M is the lubrication frequency M a and the oil injection timing T M This lubrication frequency M a In this case, oil is supplied to the skirt portion 6b in the order of cycle number Y in the following pattern: "none" → "yes" → "none" → "none" → "yes" → "none" → "yes" → "none" → "yes", ... → "none". Oil supply rate Q N is the lubrication rate Q a / 2, the oiling rate QM =(Q a / 2) × R, and the lubrication frequency M is the lubrication frequency M d and the oil injection timing T M This lubrication frequency M d In this case, oil is supplied to the skirt portion 6b in the order of cycle number Y in the following pattern: "none" → "none" → "none" → "yes" → "none" → "yes" → "none" → "none", ... → "yes". Oil supply rate Q N is the lower limit of the oil supply rate Q c If the oil injection rate Q M =Q c × R, and the lubrication frequency M is the lubrication frequency M e and the oil injection timing T M This lubrication frequency M e In this case, oil is supplied to the skirt portion 6b in the order of cycle number Y in the following pattern: "none" → "none" → "none" → "none" → "none" → "yes" → "none", ... → "yes".

[0063] In addition, the oil supply timing T N , T M The oil supply timing T is an example of the oil supply timing for each of the piston upper portion 5a and the skirt portion 6b, and is not intended to limit the present invention. N , T M 3 and 4 may be used as the timing of oil supply, as long as the oil supply to the piston upper portion 5a and the oil supply to the skirt portion 6b do not overlap within one piston cycle.

[0064] (Oil application to the upper part of the piston) Next, oil supply to the piston upper portion 5a will be described in detail. Fig. 5 is a schematic diagram showing an example of oil supply to the piston upper portion 5a in an embodiment of the present invention. In this embodiment, oil is supplied to the piston upper portion 5a when the piston 5 rises from the bottom dead center Cb side to the top dead center Ct side during the reciprocating motion inside the cylinder 1, for example.

[0065] 5, the piston 5 moves up inside the cylinder liner 2 with the piston rings 7a to 7c in sliding contact with the inner circumferential surface 2a of the cylinder liner 2. At this time, the piston 5 moves up toward the position of the oil filler port of the oil filler rod 11 provided in the cylinder liner 2.

[0066] At the timing when the crank angle of the marine internal combustion engine reaches crank angle A (hereinafter referred to as the first timing), the ascending piston 5 reaches a predetermined position on the piston upper portion 5a, for example, as shown in FIG. 5, where the lower end of the crown portion 6a faces the oil filler port of the oil filler rod 11. Note that, as shown in FIG. 5, the lower end of the crown portion 6a is adjacent to the upper end of the uppermost piston ring 7a. At this first timing, as shown in FIG. 5, the supply of lubricating oil 30 to the piston upper portion 5a begins. At this time, the lubricating oil 30 is first discharged from the oil filler rod 11 to the lower end of the crown portion 6a.

[0067] The piston 5 then continues to rise inside the cylinder liner 2 and reaches a position where the lower end of the piston upper portion 5a, i.e., the lowest piston ring 7c, faces the oil inlet of the oil filler rod 11, as shown in FIG. 5 . When the ascending piston 5 reaches this position (hereinafter referred to as the second timing), the supply of lubricating oil 30 to the piston upper portion 5a ends. That is, the lubricating oil 30 continues to be discharged from the oil filler rod 11 to the piston upper portion 5a during the period from the first timing to the second timing. This period is the same as the period from the opening of the solenoid valve 13 shown in FIG. 1 until the closing of the solenoid valve 13 (the period during which the open state is maintained). The lubricating oil 30 is supplied to the region of the ascending piston 5 from the lower end of the crown portion 6a to the lowest piston ring 7c.

[0068] The piston 5 thus filled with the lubricating oil 30 continues to reciprocate inside the cylinder liner 2 while spreading the lubricating oil 30 with the piston rings 7a to 7c. As a result, an oil film of the lubricating oil 30 is formed between the inner circumferential surface 2a of the cylinder liner 2 and the piston 5.

[0069] (Oil application to piston skirt) Next, oil supply to the piston skirt (i.e., skirt portion 6b of piston 5) will be described in detail. Fig. 6 is a schematic diagram showing an example of oil supply to the piston skirt in an embodiment of the present invention. In this embodiment, oil is supplied to the skirt portion 6b when, for example, the piston 5 descends from the top dead center Ct side to the bottom dead center Cb side during the reciprocating motion inside the cylinder 1.

[0070] 6, the piston 5 descends inside the cylinder liner 2 with the piston rings 7a to 7c in sliding contact with the inner circumferential surface 2a of the cylinder liner 2. At this time, the piston 5 descends toward the position of the oil filler port of the oil filler rod 11 provided in the cylinder liner 2.

[0071] Here, at the timing when the crank angle of the marine internal combustion engine reaches crank angle B (hereinafter referred to as the third timing), the descending piston 5 reaches a predetermined portion of the skirt portion 6b, for example, a position where the lower end of the skirt portion 6b faces the oil filler port of the oil filler rod 11, as shown in FIG. 6. At this third timing, the supply of lubricating oil 30 to the skirt portion 6b begins, as shown in FIG. 6. At this time, the lubricating oil 30 is first discharged from the oil filler rod 11 to the lower end of the skirt portion 6b.

[0072] The piston 5 then continues to descend inside the cylinder liner 2 and reaches a position where the upper end of the skirt portion 6b faces the oil inlet of the oil filler rod 11, as shown in FIG. 6. The upper end of the skirt portion 6b is adjacent to the lower end of the lowest piston ring 7c, as shown in FIG. 6. When the descending piston 5 reaches this position (hereinafter referred to as the fourth timing), the supply of the lubricating oil 30 to the skirt portion 6b ends. That is, the lubricating oil 30 continues to be discharged from the oil filler rod 11 to the skirt portion 6b during the period from the third timing to the fourth timing. This period is the same as the period from the opening of the solenoid valve 13 shown in FIG. 1 to the closing of the solenoid valve 13. The lubricating oil 30 is supplied to the region of the descending piston 5 from the lower end to the upper end of the skirt portion 6b.

[0073] The piston 5 thus filled with the lubricating oil 30 continues to reciprocate inside the cylinder liner 2 while spreading the lubricating oil 30 with the piston rings 7a to 7c, etc. As a result, an oil film of the lubricating oil 30 is formed between the inner circumferential surface 2a of the cylinder liner 2 and the skirt portion 6b.

[0074] (Oil control) Next, the oil supply control by the cylinder oil supply system 10 according to the embodiment of the present invention will be described in detail. Fig. 7 is a flowchart showing an example of a processing flow of the oil supply control by the cylinder oil supply system according to the embodiment of the present invention. The cylinder oil supply system 10 (see Fig. 1) controls the supply of lubricating oil to the piston 5 in the cylinder 1 by appropriately performing each process of steps S101 to S116 shown in Fig. 7.

[0075] In detail, as shown in FIG. 7, the cylinder oil supply system 10 controls the reference oil supply rate Q s In step S101, the central control unit 17 sets the oil supply rate when the engine load is 100% as the reference oil supply rate Q s Set as.

[0076] For example, if the designated value of the reference oil supply rate is not input to the control device 16 from the operation device 15, the central control unit 17 refers to the first data table 18a and selects one of the multiple oil supply rates Q N Maximum oil injection rate Q a The standard lubrication rate Q s Alternatively, when a designated value for the reference oil supply rate is input to the control device 16 from the operation device 15, the central control unit 17 sets the reference oil supply rate Q based on the input designated value. s At this time, the central control unit 17 sets a plurality of oil supply rates Q registered in the first data table 18a. N The oil injection rate closest to the specified value is the reference oil injection rate Q s For example, these multiple oil injection rates Q N If there is an oil injection rate with the same value as the specified value in the table, the central control unit 17 sets the oil injection rate with the same value as the specified value as the reference oil injection rate Q s These multiple oil injection rates Q N If there is no oil injection rate with the same value as the specified value among the multiple oil injection rates Q N The oiling rate with the smallest difference from the above specified value is the reference oiling rate Q s Set as.

[0077] After executing the process of step S101, the cylinder lubrication system 10 derives the lubricating oil feeding rate Q of the lubricating oil to be fed to the piston 5 in the cylinder 1 (step S102). In step S102, the central control unit 17 derives the lubricating oil feeding rate Q in accordance with the engine load of the marine internal combustion engine.

[0078] In detail, when the operating mode of the marine internal combustion engine is the mean effective pressure proportional mode, the control device 16 acquires the current engine speed of the marine internal combustion engine detected by the speed detector 22 and the current engine load of the marine internal combustion engine detected by the load detector 23. The central control unit 17 calculates the mean effective pressure of cylinder 1 based on the acquired engine speed and engine load. Next, the central control unit 17 calculates the ratio of the calculated mean effective pressure to the mean effective pressure when the engine load is 100%, and compares this obtained ratio with the reference oil supply rate Q s Alternatively, when the operating mode of the marine internal combustion engine is the output proportional mode, the control device 16 acquires the current engine load of the marine internal combustion engine detected by the load detector 23. The central control unit 17 calculates the reference oil injection rate Q according to the current engine load by multiplying the reference oil injection rate Q by the engine load. s By multiplying the calculated value by the above formula, the oil supply rate Q corresponding to the current engine load is calculated.

[0079] After executing the process of step S102, the cylinder lubrication system 10 determines the level of the derived oil supply rate Q (step S103). In step S103, the central control unit 17 compares the oil supply rate Q derived by the process of step S102 with the upper limit oil supply rate Q registered in the first data table 18a. b and the lower limit oil supply rate Q c By this comparison process, the central control unit 17 determines whether the oil supply rate Q is equal to or lower than the upper limit oil supply rate Q b Whether the oil injection rate Q exceeds the lower limit oil injection rate Q c Above, upper limit lubrication rate Q b Whether the oil supply rate Q is within the following range or not, the lower limit oil supply rate Q c It is determined whether or not the value is less than .

[0080] The upper limit of the oil supply rate Q is the oil supply rate Q b If Q>Q (step S103, b ), the control device 16 determines the oil supply frequency and timing at the oil supply rate Q for the upper half portion of the piston 5 (piston upper side portion 5a) (step S104).

[0081] In step S104, the oil supply rate Q is calculated based on the oil supply rate Q registered in the first data table 18a. N Of these, the upper limit of oil injection rate Q b Super, maximum lubrication rate Q a The central control unit 17 calculates the lubrication frequency N and the lubrication timing T registered in the first data table 18a. N Among these, the central control unit 17 determines the oil supply frequency and oil supply timing corresponding to this oil supply rate Q as the oil supply frequency and oil supply timing to the piston upper part 5a. That is, the central control unit 17 determines the frequency at which lubricating oil is supplied to the piston upper part 5a for each fixed cycle period, the piston cycle to which lubricating oil is supplied among the multiple piston cycles included in the fixed cycle period, and the target of oil supply (piston upper part 5a) for each piston cycle. The central control unit 17 instructs the drive control unit 19 of the oil supply frequency and oil supply timing determined as above.

[0082] After executing the process of step S104, the cylinder lubrication system 10 controls the supply of lubricating oil to the piston upper portion 5a (step S105). In step S105, the drive control unit 19 controls the opening and closing drive of the solenoid valve 13 so that the lubricator 12 supplies lubricating oil at the lubrication frequency and timing instructed by the central control unit 17 through the process of step S104.

[0083] Specifically, the drive control unit 19 determines the frequency N of oil supply to the piston upper portion 5a per fixed cycle period based on the oil supply frequency instructed by the central control unit 17. Furthermore, the drive control unit 19 determines the cycle number Y of a piston cycle with oil supply in which oil is supplied to the piston upper portion 5a within the fixed cycle period, and the crank angle A at which the oil supply is performed, based on the oil supply timing instructed by the central control unit 17. Furthermore, the drive control unit 19 sequentially acquires the crank angles of the marine internal combustion engine detected by the angle detector 21 in chronological order. The drive control unit 19 controls the solenoid valve 13 to open at the timing when the acquired crank angle becomes crank angle A in the piston cycle with oil supply to the piston upper portion 5a. Thereafter, the drive control unit 19 controls the solenoid valve 13 to close while maintaining the open state for a predetermined period. The drive control unit 19 grasps one cycle of the piston cycle based on the crank angle detected by the angle detector 21, and sequentially controls the opening and closing drive of the solenoid valve 13 as described above in order of the cycle number Y of the piston cycle (chronological order). While the solenoid valve 13 is in the open state, the lubricator 12 injects lubricating oil through the oil injection rod 11 or the like to the piston upper part 5a of the piston 5 rising inside the cylinder 1, as shown in FIG. 5, for example.

[0084] After executing the process of step S105, the cylinder lubrication system 10 determines whether the engine load of the marine internal combustion engine is constant (step S106). In step S106, the central control unit 17 determines that the engine load is not constant (has changed) if there is a change of a predetermined value or more between each of the engine loads sequentially acquired from the load detector 23. Furthermore, the central control unit 17 determines that the engine load is constant if the difference between each of the engine loads sequentially acquired from the load detector 23 is less than a predetermined value.

[0085] If the engine load is constant in step S106 (Yes in step S106), the cylinder lubrication system 10 returns to step S105 and repeats the processing from step S105 onwards. On the other hand, if the engine load has changed in step S106 (No in step S106), the cylinder lubrication system 10 returns to step S102 and repeats the processing from step S102 onwards.

[0086] On the other hand, in the process of step S103 described above, the oil supply rate Q is lower than the lower limit oil supply rate Q c Above, upper limit lubrication rate Q b If it is within the following range (step S103, Q c ≦Q≦Q b ), the control device 16 determines the oil supply frequency and timing at the oil supply rate Q for the piston upper portion 5a and the skirt portion 6b of the piston 5 (step S107).

[0087] In step S107, the oil supply rate Q is calculated based on the oil supply rate Q registered in the first data table 18a. N Of these, the lower limit oil injection rate Q c Above, upper limit lubrication rate Q b The value is equal to any one of the values ​​within the following ranges. The central control unit 17 determines the oil supply frequency and oil supply timing corresponding to this oil supply rate Q as the oil supply frequency and oil supply timing for the piston upper part 5a, similar to step S104 described above.

[0088] In step S107, the central control unit 17 calculates the lubrication frequency M and the lubrication timing T registered in the second data table 18b. MThe central control unit 17 determines the oil supply frequency and oil supply timing corresponding to the product of the oil supply rate Q and the constant rate R (oil supply rate Q×R) as the oil supply frequency and oil supply timing to the skirt portion 6b. That is, the central control unit 17 determines the frequency at which lubricating oil is supplied to each of the piston upper portion 5a and the skirt portion 6b for each constant cycle period, the piston cycles to which lubricating oil is supplied among the multiple piston cycles included in the constant cycle period, and the target of oil supply for each piston cycle (either the piston upper portion 5a or the skirt portion 6b). The central control unit 17 instructs the drive control unit 19 of the oil supply frequency and oil supply timing determined as described above.

[0089] After executing the process of step S107, the cylinder lubrication system 10 determines whether or not to permit the supply of lubricating oil to the skirt portion 6b (step S108). In the cylinder lubrication system 10, the user operates the operation device 15 to input permission information to the control device 16, thereby permitting the supply of lubricating oil to the skirt portion 6b. In step S108, if permission information is input to the control device 16 from the operation device 15, the central control unit 17 permits the drive control unit 19 to supply lubricating oil to the skirt portion 6b by processing such as setting a permission flag based on the input permission information. On the other hand, if permission information is not input to the control device 16 from the operation device 15, the central control unit 17 prohibits the drive control unit 19 from supplying lubricating oil to the skirt portion 6b.

[0090] In step S108, if the supply of lubricating oil to the skirt portion 6b is permitted (step S108, Yes), the cylinder lubrication system 10 controls the supply of lubricating oil to each of the piston upper portion 5a and the skirt portion 6b (step S109). In step S109, the drive control unit 19 controls the opening and closing drive of the solenoid valve 13 so that the lubricator 12 supplies lubricating oil at the lubrication frequency and timing instructed by the central control unit 17 in the processing of step S107.

[0091] Specifically, as in step S105 described above, the drive control unit 19 determines, for the piston upper portion 5a, the oil supply frequency N per fixed cycle period, the cycle number Y of the piston cycle with oil supply within the fixed cycle period, and the crank angle A at which the oil supply is performed. Furthermore, the drive control unit 19 determines the oil supply frequency M to the skirt portion 6b per fixed cycle period based on the oil supply frequency for the skirt portion 6b instructed by the central control unit 17. Furthermore, the drive control unit 19 determines the cycle number Y of the piston cycle with oil supply for the skirt portion 6b within the fixed cycle period and the crank angle B at which the oil supply is performed based on the oil supply timing for the skirt portion 6b instructed by the central control unit 17. The drive control unit 19 synchronizes the piston cycle for the piston upper portion 5a within the fixed cycle period with the piston cycle for the skirt portion 6b within the fixed cycle period. That is, the cycle number Y of the piston cycle for the piston upper portion 5a within the fixed cycle period is common to both the piston upper portion 5a and the skirt portion 6b.

[0092] The drive control unit 19 also sequentially acquires the crank angles of the marine internal combustion engine detected by the angle detector 21 in chronological order. The drive control unit 19 controls the opening and closing drive of the solenoid valve 13 for the supply of lubricating oil to the piston upper portion 5a in the same manner as in step S105 described above. In parallel with this, the drive control unit 19 controls the solenoid valve 13 to open at the timing when the acquired crank angle becomes crank angle B in a piston cycle with oil supply to the skirt portion 6b. Thereafter, the drive control unit 19 controls the solenoid valve 13 to close while maintaining the open state for a predetermined period of time. The drive control unit 19 identifies one piston cycle based on the crank angle detected by the angle detector 21, and sequentially executes the above-described control of the opening and closing drive of the solenoid valve 13 in the order of the cycle number Y of the piston cycle (in chronological order).

[0093] During the period when the solenoid valve 13 is continuously open from the first timing (the timing of crank angle A) to the second timing, the lubricator 12 injects lubricating oil through the oil dosing rod 11 or the like to the piston upper part 5a of the piston 5 ascending within the cylinder 1, as shown in Fig. 5 for example. Furthermore, during the period when the solenoid valve 13 is continuously open from the third timing (the timing of crank angle B) to the fourth timing, as shown in Fig. 6 for example, in a piston cycle different from the timing of injecting lubricating oil to the piston upper part 5a, the lubricator 12 injects lubricating oil through the oil dosing rod 11 or the like to the skirt part 6b of the piston 5 descending within the cylinder 1.

[0094] On the other hand, if the supply of lubricating oil to the skirt portion 6b is not permitted in step S108 (step S108, No), the cylinder lubrication system 10 does not supply lubricating oil to the skirt portion 6b, but controls the supply of lubricating oil to the piston upper portion 5a (step S110). In step S110, the drive control unit 19 controls the opening and closing drive of the solenoid valve 13 so that the lubricator 12 supplies lubricating oil to the piston upper portion 5a at the lubrication frequency and timing specified by the central control unit 17 in the processing of step S107.

[0095] Specifically, the drive control unit 19 controls the opening and closing of the solenoid valve 13 so that lubricating oil is dispensed to the piston upper portion 5a, similar to step S105 described above. Furthermore, even when the crank angle acquired from the angle detector 21 reaches crank angle B, the drive control unit 19 does not control the opening and closing of the solenoid valve 13, thereby prohibiting the lubricant dispenser 12 from dispensing lubricating oil to the skirt portion 6b. During the period when the solenoid valve 13 remains open from the first timing to the second timing, the lubricant dispenser 12 dispenses lubricating oil to the piston upper portion 5a of the piston 5 ascending within the cylinder 1 via the lubricant dispenser rod 11 or the like, as shown in FIG. 5, for example. Meanwhile, the lubricant dispenser 12 does not dispense lubricating oil to the skirt portion 6b.

[0096] After executing the processing of step S109 or step S110, the cylinder lubrication system 10 determines whether or not the engine load of the marine internal combustion engine is constant (step S111). In step S111, the central control unit 17 determines whether or not the engine load is constant, similar to step S106 described above.

[0097] If the engine load is constant in step S111 (Yes in step S111), the cylinder lubrication system 10 returns to step S108 and repeats the processing from step S108 onwards. On the other hand, if the engine load has changed in step S111 (No in step S111), the cylinder lubrication system 10 returns to step S102 and repeats the processing from step S102 onwards.

[0098] Here, when the cylinder lubrication system 10 repeatedly executes the processes of steps S108 to S111, there is a possibility that the supply of lubricant to the skirt portion 6b will be temporarily prohibited and then permitted. In this case, the supply of lubricant to the skirt portion 6b may be additionally initiated from an intermediate piston cycle within the fixed cycle period in which the supply of lubricant to the piston upper portion 5a has begun. In this embodiment, as described above, the piston cycle within the fixed cycle period for the piston upper portion 5a and the piston cycle within the fixed cycle period for the skirt portion 6b are synchronized. Therefore, even if the supply of lubricant to the skirt portion 6b is additionally initiated from an intermediate piston cycle as described above, it is possible to avoid a situation in which the supply of lubricant to the piston upper portion 5a and the supply of lubricant to the skirt portion 6b overlap within a single piston cycle.

[0099] On the other hand, in the process of step S103 described above, the oil supply rate Q is lower than the lower limit oil supply rate Q c If the value is less than (step S103, Q c ), the control device 16 determines the lower limit oil supply rate Q instead of the oil supply rate Q for the piston upper portion 5a and the skirt portion 6b of the piston 5. c The oil supply frequency and timing are determined (step S112). ​

[0100] In step S112, the lower limit oil supply rate Q c is the oil supply rate Q registered in the first data table 18a N The central control unit 17 determines the minimum oil injection rate Q c The oil supply frequency and oil supply timing corresponding to the above are determined as the oil supply frequency and oil supply timing for the piston upper portion 5a in the same manner as in step S107 described above.

[0101] In step S112, the central control unit 17 calculates the oil supply frequency M and the oil supply timing T registered in the second data table 18b. M Of these, the lower limit oil supply rate Q c and a constant rate R (oil supply rate Q c ×R) as the lubrication frequency and lubrication timing for the skirt portion 6b, similar to step S107 described above. The central control unit 17 instructs the drive control unit 19 on the lubrication frequency and lubrication timing determined as above.

[0102] After executing the process of step S112, the cylinder lubrication system 10 determines whether or not to permit the supply of lubricating oil to the skirt portion 6b (step S113). In step S113, similar to step S108 described above, the central control unit 17 permits the supply of lubricating oil to the skirt portion 6b based on the permission information input from the operation device 15 to the control device 16, and prohibits the supply of lubricating oil to the skirt portion 6b if the permission information has not been input.

[0103] In step S113, if the supply of lubricating oil to the skirt portion 6b is permitted (step S113, Yes), the cylinder lubrication system 10 controls the supply of lubricating oil to each of the piston upper portion 5a and the skirt portion 6b (step S114). In step S114, the drive control unit 19 controls the supply of lubricating oil to each of the piston upper portion 5a and the skirt portion 6b. cExcept for the above-described step S109, the opening and closing of the solenoid valve 13 is controlled for each of the piston upper portion 5a and the skirt portion 6b.

[0104] On the other hand, in the above-mentioned step S113, if the supply of lubricating oil to the skirt portion 6b is not permitted (step S113, No), the cylinder lubrication system 10 does not supply lubricating oil to the skirt portion 6b, but controls the supply of lubricating oil to the piston upper portion 5a (step S115). In step S115, the drive control unit 19 determines whether the oil supply rate Q is equal to or lower than the lower limit oil supply rate Q c Except for the fact that step S110 is replaced by step S111, the opening and closing drive of the solenoid valve 13 is controlled for the piston upper portion 5a in the same manner as step S110 described above.

[0105] After executing the processing of step S114 or step S115, the cylinder lubrication system 10 determines whether or not the engine load of the marine internal combustion engine is constant (step S116). In step S116, the central control unit 17 determines whether or not the engine load is constant, similar to step S106 described above.

[0106] If the engine load is constant in step S116 (Yes in step S116), the cylinder lubrication system 10 returns to step S113 and repeats the processing from step S113 onwards. On the other hand, if the engine load has changed in step S116 (No in step S116), the cylinder lubrication system 10 returns to step S102 and repeats the processing from step S102 onwards.

[0107] Furthermore, even when the processes of steps S113 to S116 described above are repeatedly executed, the piston cycle within a certain cycle period for the piston upper portion 5a and the piston cycle within a certain cycle period for the skirt portion 6b are synchronized, so it is possible to avoid a situation in which the supply of lubricating oil to the piston upper portion 5a and the supply of lubricating oil to the skirt portion 6b overlap within one piston cycle.

[0108] Furthermore, when the engine load changes, in step S102 described above, the oil supply rate Q is calculated in accordance with the changed engine load. Thereafter, in each of steps S104, S107, and S112 described above, the oil supply frequency and timing to the piston 5 are switched to the oil supply frequency and timing at the oil supply rate Q after the change in engine load. In each of steps S105, S109, S110, S114, and S115 described above, the supply of lubricating oil to the piston 5 is controlled at the oil supply frequency and oil supply timing switched in accordance with the change in engine load as described above. At this time, even if the oil supply control had progressed to an intermediate piston cycle within the fixed cycle period before the change in engine load, the supply of lubricating oil to the piston 5 is re-controlled from the first piston cycle (cycle number Y=1) within the fixed cycle period at the oil supply frequency and oil supply timing after the switch.

[0109] In addition, in the cylinder lubrication system 10, whenever a new specified value for the standard lubrication rate is input from the operating device 15, the control device 16 may perform the processing of the above-mentioned step S101, and then repeat the processing from step S102 onwards as appropriate.

[0110] As described above, in the cylinder lubrication system 10 according to an embodiment of the present invention, the control device 16 derives the lubricating oil feed rate Q for the piston 5 in accordance with the engine load of the marine internal combustion engine, determines the frequency and timing of lubricating oil feed to each of the upper half of the piston 5 (the piston upper portion 5a) and the skirt portion 6b at the derived lubricating oil feed rate Q, and controls the opening and closing drive of the solenoid valve 13 so that the lubricator 12 feeds lubricating oil to the piston 5 at the determined frequency and timing. Based on the drive control by the control device 16, when the solenoid valve 13 is closed, the lubricator 12 accumulates lubricating oil. When the solenoid valve 13 is open, the lubricator 12 feeds lubricating oil to the piston 5 reciprocating inside the cylinder 1 of the marine internal combustion engine through the lubricating rod 11 provided in the cylinder 1.

[0111] This makes it possible to control the frequency and timing of lubricating oil supply to each of the piston upper portion 5a and the skirt portion 6b in accordance with the in-cylinder pressure applied to the crown portion 6a of the piston 5. This allows the lubricating oil required to ensure slidability of the piston 5 relative to the inner circumferential surface 2a of the cylinder 1 to be supplied between the piston 5 and the inner circumferential surface 2a of the cylinder 1, and also prevents excessive supply of lubricating oil to the skirt portion 6b when the in-cylinder pressure increases and the piston 5 is difficult to tilt inside the cylinder 1, and prevents insufficient supply of lubricating oil to the skirt portion 6b when the in-cylinder pressure decreases and the piston 5 is easy to tilt inside the cylinder 1. As a result, it is possible to prevent excess or deficiency of lubricating oil from being supplied to each of the piston upper portion 5a and the skirt portion 6b, thereby enabling efficient supply of lubricating oil to the piston 5 reciprocating inside the cylinder 1.

[0112] Furthermore, in the cylinder lubrication system 10 according to the embodiment of the present invention, the control device 16 determines the frequency and timing of lubricating oil supply to the piston upper portion 5a and the frequency and timing of lubricating oil supply to the skirt portion 6b so that the lubricating oil supply rate to the skirt portion 6b is a constant ratio to the lubricating oil supply rate to the piston upper portion 5a. This allows lubricating oil to be supplied to each of the piston upper portion 5a and the skirt portion 6b in a balanced manner, thereby further improving the efficiency of lubricating oil supply to the piston 5.

[0113] Furthermore, in the cylinder lubrication system 10 according to the embodiment of the present invention, the control device 16 sets a reference oil feed rate for when the engine load is 100% based on a designated value variably input via the operation device 15, and derives the lubricant feed rate Q corresponding to the engine load based on the set reference oil feed rate. Therefore, the reference oil feed rate can be easily changed by changing the designated value input in response to a user's input operation. This makes it possible to reduce the reference oil feed rate depending on the operating time (working time) of the marine internal combustion engine, the condition of the piston rings provided on the piston 5 and the inner circumferential surface 2a of the cylinder 1, and the like. As a result, it is possible to promote a reduction in the costs required for operating the ship.

[0114] Furthermore, in the cylinder lubrication system 10 according to the embodiment of the present invention, the control device 16 permits the supply of lubricating oil to the skirt portion 6b of the piston 5 based on the permission information input by the operation device 15. Therefore, the user can select whether or not to permit the supply of lubricating oil to the skirt portion 6b, and thus the supply of lubricating oil to the skirt portion 6b can be performed as needed at the user's discretion.

[0115] Furthermore, in the cylinder lubrication system 10 according to an embodiment of the present invention, the opening and closing drive of the solenoid valve 13 is controlled based on the crank angle of the marine internal combustion engine so that the lubricator 12 injects lubricating oil to the piston upper portion 5a of the ascending piston 5 or to the skirt portion 6b of the descending piston 5. As a result, the lubricating oil injected to the piston upper portion 5a can be spread to form an oil film between the inner circumferential surface 2a of the cylinder 1 and at least the piston upper portion 5a as the piston 5 reciprocates. Furthermore, the lubricating oil injected to the skirt portion 6b can be spread to form an oil film between the inner circumferential surface 2a of the cylinder 1 and at least the skirt portion 6b as the piston 5 reciprocates. As a result, a lubricating oil film can be efficiently formed between the inner circumferential surface 2a of the cylinder 1 and the piston 5 to ensure the slidability of the piston 5 relative to the inner circumferential surface 2a.

[0116] In the above-described embodiment, an example was given in which eight oil supply rods 11 are provided in one cylinder 1, but the present invention is not limited to this. In the present invention, the number of oil supply rods 11 provided in one cylinder 1 is not particularly limited, and may be, for example, two or more (plural).

[0117] In the above-described embodiment, lubricating oil is supplied to the piston upper portion 5a when the piston 5 is ascending, and lubricating oil is supplied to the skirt portion 6b when the piston 5 is descending. However, the present invention is not limited to this. For example, lubricating oil may be supplied to the piston upper portion 5a when the piston 5 is descending. In this case, the supply of lubricating oil may start from the position of the lowest piston ring 7c on the piston upper portion 5a. Furthermore, lubricating oil may be supplied to the skirt portion 6b when the piston 5 is ascending. In this case, the supply of lubricating oil may start from the upper end portion of the skirt portion 6b (the portion adjacent to the lowest piston ring 7c).

[0118] In the above-described embodiment, the supply of lubricating oil to the skirt portion 6b is permitted when permission information is input to the control device 16, but the present invention is not limited to this. For example, the operating device 15 may input prohibition information for prohibiting the supply of lubricating oil to the skirt portion 6b to the control device 16 in response to an input operation by the user, and the control device 16 may prohibit the supply of lubricating oil to the skirt portion 6b based on the input prohibition information.

[0119] In the above-described embodiment, one operating device 15 is provided with both the function of a first input unit for inputting a designated value of the reference oil supply rate and the function of a second input unit for inputting permission information for oil supply to the skirt portion 6b, but the present invention is not limited to this. For example, the cylinder oil supply system 10 may be provided with the above-described first input unit and second input unit as separate input units (operating devices).

[0120] In the above-described embodiment, three piston rings are used as an example of the number of piston rings provided on the outer periphery of the piston body, but the present invention is not limited to this. For example, two or more piston rings may be provided on the outer periphery of the piston body so as to be aligned in the reciprocating direction of the piston body.

[0121] In addition, in the above-described embodiment, the angle detector 21, the rotation speed detector 22, and the load detector 23 are provided in a marine internal combustion engine, but the present invention is not limited to this. For example, the angle detector 21, the rotation speed detector 22, and the load detector 23 may each be a configuration example of the cylinder lubrication system 10 according to an embodiment of the present invention. Similarly, the temperature detector 24 and the pressure detector 25 may also be a configuration example of the cylinder lubrication system 10.

[0122] Furthermore, the present invention is not limited to the above-described embodiments. Configurations that appropriately combine the above-described components are also included in the present invention. In addition, other embodiments, examples, operational techniques, etc. that are made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention. [Explanation of symbols]

[0123] 1 cylinder 2 Cylinder Liners 2a Inner surface 3 Cylinder cover 4 Combustion chamber 5 pistons 5a Upper part of piston 6 Piston body 6a Crown 6b Skirt section 6c middle part 7a, 7b, 7c piston rings 8 Piston rod 9 Exhaust valve 10 Cylinder Lubrication System 11 Lubrication rod 12 Lubricator 13 Solenoid valve 14 Refueling unit 15 Operating device 16 Control device 17 Central Control Unit 18a First Data Table 18b Second Data Table 19 Drive control unit 21 Angle detector 22 Rotational speed detector 23 Load detector 24 Temperature detector 25 Pressure detector 30 Lubricating oil Ct top dead center Cb bottom dead center

Claims

1. an oil dispenser that dispenses lubricating oil through an oil dispenser rod provided in a cylinder of a marine internal combustion engine to a piston that reciprocates inside the cylinder; a solenoid valve that, when closed, causes the lubricant dispenser to store the lubricant and, when open, causes the lubricant dispenser to dispense the lubricant to the piston; a control device that derives an oil supply rate of the lubricating oil in accordance with a load of the marine internal combustion engine, determines an oil supply frequency and an oil supply timing of the lubricating oil to each of the piston upper portion and the skirt portion of the piston at the derived oil supply rate, and controls the opening and closing drive of the solenoid valve so that the lubricating oil dispenser dispenses the lubricating oil at the determined oil supply frequency and oil supply timing; a permission information input unit that inputs permission information for permitting the supply of the lubricating oil to the skirt portion into the control device; Equipped with The control device permits the supply of the lubricating oil to the skirt portion based on the input permission information. A cylinder lubrication system comprising:

2. the control device determines a frequency and timing of supplying the lubricating oil to the piston upper portion and a frequency and timing of supplying the lubricating oil to the skirt portion so that a rate of supplying the lubricating oil to the skirt portion is a constant rate with respect to a rate of supplying the lubricating oil to the piston upper portion.

2. The cylinder lubrication system of claim 1.

3. the control device sets the lubricating oil feed rate when the load of the marine internal combustion engine is 100% as a reference oil feed rate, and derives the lubricating oil feed rate according to the load of the marine internal combustion engine based on the set reference oil feed rate.

3. A cylinder lubrication system according to claim 1 or 2.

4. an input unit that inputs a designated value for designating the standard oil feeding rate in a changeable manner into the control device, The control device sets the reference oil feeding rate based on the input designated value.

4. The cylinder lubrication system of claim 3.

5. the control device determines, for each cycle included in a fixed cycle period in which one reciprocating motion of the piston is one cycle, whether to inject the lubricating oil into the piston, and, when injecting the lubricating oil, whether to inject the lubricating oil into an upper portion of the piston or into the skirt portion; 5. A cylinder lubrication system according to claim 1.

6. the control device controls the opening and closing drive of the solenoid valve based on a crank angle of the marine internal combustion engine so that the oil dispenser dispenses the lubricating oil to the upper portion of the piston when the piston is rising or to the skirt portion of the piston when the piston is falling.

6. A cylinder lubrication system according to claim 1.

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