EP1582706B1

EP1582706B1 - Internal combustion engine with cylinder lubricating system

Info

Publication number: EP1582706B1
Application number: EP05006988A
Authority: EP
Inventors: Satoru Murata; Sadao Yoshihara; Tetsuya Yamamoto; Motoki Izumi; Takashi Sonoda
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2004-03-31
Filing date: 2005-03-31
Publication date: 2008-07-16
Anticipated expiration: 2025-03-31
Also published as: CN101054913A; DK1582706T3; EP1582706A2; KR20070041697A; EP1582706A3; CN100549369C; KR100750542B1; DE602005008126D1; CN1676888B; CN1676888A; KR20060045405A

Description

BACKGROUND OF THE INVENTION

Field of the invention

The present invention relates to an internal combustion engine with a cylinder lubricating system applied to a large marine diesel engine, etc., lubricating oil pressure-fed by a lubricating oil pump being accommodated in a common lube oil feeding section, the lubricating oil in the common lube oil feeding section being supplied to a plurality of lubricators attached to engine cylinders to be supplied to the inner surfaces of the cylinders by the system.

Description of the Related Art

In large marine diesel engines, mechanical cylinder lubricating system are widely used, in which, as disclosed for example in patent literature 1 ( Japanese Laid-Open Utility Model Application No. 59-175619 or EP 0 049 603 ), a plurality of lubricators are arranged along the circumferential direction of a cylinder, and lubricating oil pressure-fed by an oil pump of plunger type driven by the rotation of the crankshaft is supplied to the inner surface of the cylinder by said lubricators.
In the lubricating system, a plurality of lubricators (injectors) are arranged along the circumferential direction of the cylinder, a rocker arm is oscillated by a cam formed on a cam shaft driven by the crankshaft of the engine, the plunger of a plunger type oil pump is provided so that an end of which contacts an end of the rocker arm. The plunger of the plunger type oil pump is reciprocated by the rocker arm through the rotation of the cam, and lubricating oil is supplied through an oil pipe connecting the oil pump to each of the lubricators at timing in syntonization with the rotation of the crankshaft to be supplied to the inner surface of the cylinder by the lubricators. With the mechanical cylinder lubricating system disclosed in said patent literature 1, lubricating oil is supplied to the inner surface of the cylinder from the lubricators at timing in syntonization with engine rotation, so that the lube oil feed timing and the characteristic of lube oil feed quantity are determined at the stage of engine assembling, the timing and also quantity of oil supplied are difficult to be adjusted, and it is impossible to control the lubrication timing and the quantity of lubricating oil supplied by each of a plurality of lubricators.
As it is impossible with the prior art to control the amount of lubricating oil to be supplied in accordance with varying factors such as actual properties of the lubricating oil, oil pressure, engine load, etc. Further, when some of the plurality of lubricators malfunction, other functioning lubricators can not help substitute for the function of the troubled lubricators, so that wear in the inner surface of cylinder or sticking tends to occur due to deteriorated lubrication.
With the prior art, there are problems mentioned above, and it is difficult to form an oil film extending over a wide range particularly in the axial direction in the inner surface of the cylinder. Therefore, it is difficult to achieve lubrication performance capable to meet increasing output of engine.
Further, with the prior art, as it is difficult to control the timing of injecting lubricating oil to inner surface of the cylinder, that is, to control the position of the piston when lubricating oil is injected to the inner surface of the cylinder, there may be a position for the piston not effective for lubrication, resulting in a tendency that lubricating oil consumption is increased and nevertheless wear or sticking occurs in portions where lubrication oil is insufficiently spread on the inner surface of the cylinder.
EP 0 049 603 describes a lubrication system for an internal combustion engine according to the preamble part of claim 1. It comprises a plurality of oil supply devices disposed around a cylinder bore of the engine, each oil supply device comprising in its body part a valve, operated by an electromagnetic device that opens or closes the oil flow from the body part through an oil supply passage to one of the plurality of openings disposed around the cylinder wall. The lubrication system includes an electronic control system which powers the electromagnetic devices (the valve solenoids), respectively, and provides control signals at the appropriate time to the solenoid of the valve members, thereby to allow supply of oil to the surfaces of the cylinder bore and piston rings. Timing signals are supplied to the control system according to the rotation state of the engine. Further operating parameters of the engine, such as the engine speed, the power being developed and the type and quality of fuel being used, can be provided to the control system in order that the amount of oil delivered to the piston can be varied to suit these engine operating parameters.
DE 197 43 955 discloses a cylinder lubrication device connected to several lubrication points on the internal surface of a cylinder bore. Only one lubrication device per cylinder, or one for several cylinders is disclosed. A control device controls the supply of oil to the lubrication point on each cylinder, and can be provided with signals corresponding to engine load, engine speed and other, not further specified special operating conditions.
EP 0 509 189 relates to a multi-cylinder engine comprising a cylinder lubricating means operated under electronic control, wherein one electronic control is installed for each cylinder, and the electronic controllers are installed in combination for each cylinder, so that even if a controller for one cylinder fails, the other cylinders operate normally, enabling the continued operation of the engine.

SUMMARY OF THE INVENTION

The present invention was made in light of the problems in the prior art as mentioned above. An obj ect of the invention is to provide an internal combustion engine provided with a cylinder lubricating system, in which it is possible to supply necessary amount of lubricating oil to each of lubricators or to each of positions to be supplied with lubricating oil independently and at necessary timing in order to make it possible to continue normal lube oil feeding even when malfunction occurs in some of the lubricators, and further it is possible to control the timing and amount of oil supply in accordance with varying factors such as actual properties and pressure of lubricating oil, engine load, etc. even during engine operation, and lubricating oil consumption can be reduced.
Another object of the invention is to attain lubrication performance capable of meeting increased engine output through evading wear and sticking due to lack of lubricating oil on the inner surface of cylinder by allowing the formation of oil film of uniform thickness spreading through wide range of the inner surface of cylinder, particularly along the axial direction of the cylinder, and to provide a cylinder lubricating system with which lubricating oil consumption can be reduced by eliminating non-effective lubrication.
To attain these objects, the present invention proposes an internal combustion engine provided with a lubricating system in which lube oil pressure-fed by a lube oil pump is accommodated in a common lube oil feeding section, the lube oil contained in said common lube oil feeding section is supplied to a plurality of lubricators (injectors) through lube oil passages connecting said common lube oil feeding section to said lubricators and injected to the inner surfaces of cylinders of the engine by said lubricators, wherein are provided a plurality of electromagnetic valves for opening or closing each of said lube oil passages independently, a controller for controlling the timing and period of opening of each of said electromagnetic valves independently, and wherein said controller calculates lube oil injection ratio (injection amount of lube oil per hour/engine load or engine output) on the basis of the amount of lube oil supply calculated as a function of the opening of the electromagnetic valves and engine load calculated from the detected engine rotation speed and amount of fuel input, and controls the opening period of said electromagnetic valves so that said calculated lube oil injection ratio coincides with a lube oil injection ratio determined beforehand.
According to the invention, as the timing and period of each of the electromagnetic valves connected to each of the lubricators respectively are controlled independently, the timing and amount of lube oil supply to the inner surface of each cylinder can be adjusted independently in accordance with the lubrication conditions in each cylinder at portions to be supplied with lube oil.
By this, it becomes possible to supply required amount of lube oil at required timing independently to portions to be supplied with lube oil, and supply amount of lube oil can be controlled to a minimum amount for maintaining eachportion to be supplied with lube oil in such a good lubrication condition that the occurrence of wear or sticking can be positively evaded. Therefore, lube oil consumption can be reduced compared with prior art of cylinder lubricating system in which the timing and amount of lube oil supply to a plurality of lubricators are adjusted uniformly not independently.
Moreover, by composing the controller like this, each of the electromagnetic vales is controlled so that the lube oil injection ratio(the amount of lube oil supply per an hour/engine load or engine output) calculated on the basis of the amount of lube oil supply and detected engine load coincides the targeted lube oil injection ratio, preferably a constant lube oil injection ratio all over the operation range of the engine, so that the amount of lube oil supply can be controlled accurately to supply a minimum amount of lube oil with which the inner surface of cylinder can be lubricated properly in accordance with each operating condition of the engine, and as a result, lube oil consumption can be maintained to a minimum all over the engine operating range.
In the invention, it is preferable that said controller controls said electromagnetic valves so that when at least one among two or more of said electromagnetic valves attached per cylinder malfunctions, the opening period of other valve or valves is lengthened.
By composing like this, the opening period, i.e. the supply amount of lube oil of each of the electromagnetic valves can be controlled independently, so that, when there occurs malfunction in some of the electromagnetic valves, the reduction in the amount of oil supply from lubricators connected to said malfunctioning electromagnetic valves can be complemented by lengthening the opening period of other electromagnetic valves not malfunctioning. By this, lube oil can be supplied to the inner surface of cylinder stably without influenced by the occurrence of malfunction in some of the electromagnetic valves.
In the invention, it is preferable that said controller controls the opening period of said electromagnetic valves so that the amount of oil supply which is determined as a function of the opening period of the electromagnetic valves, or lube oil injection ratio (injection amount of lube oil per hour/engine load or engine output) calculated on the basis of said amount of lube oil supply and engine load, is larger than predetermined minimum amount of lube oil supply or minimum lube oil injection ratio.
By composing like this, the amount of lube oil supply is increased by lengthening the opening period of concerned electromagnetic valve when actual amount of lube oil supply or lube oil injection ratio is smaller than the proper value corresponding to engine operating conditions such as engine rotation speed, engine load, etc., and the amount of lube oil supply is decreased by shortening the opening period of concerned electromagnetic valve when actual amount of lube oil supply or lube oil injection ratio is larger than the proper value corresponding to engine operating conditions, so that the most proper amount of lube oil, with which the inner surface of cylinder can be lubricated properly, can be supplied all over the operation range of the engine.
In the invention, it is preferable that an engine rotation speed detector for detecting the rotation speed of the engine and a fuel input sensor for detecting the amount of fuel input are provided, said controller calculates engine load on the basis of the engine rotation speed and amount of fuel input detected and controls the opening /closing of said electromagnetic valves so that lube oil is injected from said lubricators every cycle when the engine is operated at a high load higher than a certain load, and once per a few number of cycles when the engine is operated at a low load lower than said certain load, whereby stable lubrication is possible even when necessary amount of lube oil supply per unit time is small, resulting in a reduced lube oil consumption at low load operation(or low speed operation).
By composing like this, stable supplyof lube oil is possible on the basis of detected engine load (or engine rotation speed) also when the engine is operating at low load(low rotation speed) in which the amount of lube oil injected from a lubricator is small.
In the invention, it is preferable that a specific gravimeter is provided to said common lube oil feeding section, and said controller controls said electromagnetic valves so that the opening period thereof coincides with a value predetermined in correspondence with the value of specific gravity of lube oil inputted beforehand in the controller from said specific gravimeter or the value of actual specific gravity detected by said specific gravimeter.
Further, said controller controls said electromagnetic valves so that the opening timing and period thereof coincides with values predetermined in correspondence with the value of viscosity of lube oil inputted beforehand in the controller from a viscosity meter attached to the common lube oil feeding section or the value of actual viscosity detected by said viscosity meter.
By composing like this, when lube oil of large specific gravity is used, the opening period of electromagnetic valve is shortened to evade increase of mass flow due to increased specific gravity by reducing volume flow of lube oil, and the opening period is lengthened to evade decrease of mass flow due to decreased specific gravity by increasing volume flow of lube oil.
Further, it is possible to prevent a decrease in the amount of lube oil supply due to increased viscosity by advancing the opening timing and lengthening the opening period of the electromagnetic valves and lack of lube oil induced by an increased viscosity can be evaded. Therefore, the amount of lube oil supply can be maintained always to a targeted amount without influenced by the viscosity of lube oil.
Therefore, by controlling the timing and period of opening of electromagnetic valve in accordance with the properties of lube oil such as specific gravity and viscosity, lube oil supply can be controlled corresponding to the properties of lube oil.
In the invention, it is preferable that a pressure detector or a temperature detector is provided to said common lube oil feeding section, and said controller controls said electromagnetic valves so that the opening period thereof coincides with periods predetermined in correspondence with the pressure or temperature of lube oil in the common lube oil feeding section detected by and inputted from said pressure detector or temperature detector.
By composing like this, the opening period of electromagnetic valve is shortened to decrease the amount of lube oil supply as the supply pressure of lube oil in the common lube oil feeding section which is common for each cylinder increases and the opening period of electromagnetic valve is lengthened to increase the amount of lube oil supply as the pressure decreases, so that the amount of lube oil supply can be maintained always to a targeted amount without influenced by lube oil pressure.
In the invention, it is preferable that said controller controls said electromagnetic valves so that the opening period thereof coincides with periods predetermined in correspondence with the lift thereof which is predetermined or measured.
By composing like this, the opening period of electromagnetic valve is shortened when the detected lift of electromagnetic valve is larger than the predetermined value or measured value of the lift, and the opening period of electromagnetic valve is lengthened when the detected lift of electromagnetic valve is smaller than the predetermined value or measured value of the lift, so that the amount of lube oil supply can be maintained always to a targeted amount without influenced by the variations of the lift of electromagnetic valve even if the lift varies due to manufacturing errors.
In the invention, it is preferable that said controller controls said electromagnetic valves in correspondence with the predetermined or measured value of the air gap of said electromagnetic valve.
By composing like this, the opening period is controlled on the basis of the predetermined or measured air gap between the core and the armature, so that the amount of lube oil supply can be maintained always to a targeted amount without influenced by the variations of the air gap of electromagnetic valve even if the air gap varies due to manufacturing errors.
In the invention, a variety of connections between the electromagnetic valve and the lubricator can be possible as follows:

(1) A plurality of lubricators are provided per cylinder, each of said oil passages is connected to each of said lubricators, and each of said electromagnetic valves is provided to each of said oil passages.
(2) A plurality of lubricators are provided per cylinder, lube oil passages consist of a main passage and branch passages branching from said main passage and connecting to each of said lubricators respectively, an electromagnetic valve is provided to the main oil passage, and a single electromagnetic valve presides lube oil supply to a plurality of lubricators.
(3) The branched passages branching from each of the main passages are connected to lubricators located alternately along the periphery of cylinder, whereby even if one of the electromagnetic valves malfunctions lube oil can be supplied to the lubricators provided all around the periphery of cylinder excepting the lubricators connected to the malfunctioned electromagnetic valves.
(4) A plurality of lubricators are provided per cylinder and a plurality of controllers are provided to control one or a plurality of said electromagnetic valves.

A pressure regulating valve is provided to an end part of the common lube oil feeding section, and the lube oil pump discharges lube oil more than the amount injected to the cylinders of the engine. By this, lube oil in the common lube oil feeding section is allowed to circulate and the temperature of the lube oil in the common lube oil feeding section is maintained at uniform temperature.
In the invention, a return pipe is provided along the common lube oil feeding section, and heat exchange is possible between the lube oil in the common lube oil feeding section and that in the return pipe.
By this, temperature difference between the entrance and exit of the common lube oil feeding section is reduced by heating the lube oil in the common lube oil feeding section by the lube oil increased in temperature and passing through the return pipe after regulated in pressure, and the viscosity of the lube oil in the common lube oil feeding section is evened along the length of the section.
In the invention, the opening area of each of the electromagnetic valves is larger than the sum of the passage area of the lubricators connected to the concerned electromagnetic valve.
By this, even if opening areas varies among a plurality of electromagnetic valves due to the variations of valve lifts, required amount of lube oil supply through the lubricators can be achieved without influenced by the variations of valve lifts of the electromagnetic valves.
The present invention proposes a method of supplying lube oil to cylinders in a system in which the lube oil pressure-fed by a lube oil pump is supplied to lubricators attached to a cylinder through electromagnetic valves for adjusting the timing and amount of lube oil supply and oil passages to supply the lube oil to the inner surface of a cylinder in which a piston having a plurality of piston rings reciprocates, wherein lube oil is injected from the lubricators to spaces formed between the piston rings at least once per one reciprocation of piston, and wherein a lube oil injection ratio is calculated, i.e. the injection amount of lube oil per hour/engine load or engine output, on the basis of the amount of lube oil supply calculated as a function of the opening of the electromagnetic valves and engine load calculated from the detected engine rotation speed and amount of fuel input, and the opening period of said electromagnetic valves is controlled so that said calculated lube oil injection ratio coincides with a lube oil injection ratio determined beforehand.
The above recited method of supplying lube oil to cylinders is performed by a cylinder lubricating system in which the lube oil pressure-fed by a lube oil pump is supplied to lubricators attached to a cylinder through electromagnetic valves for adjusting the timing and amount of lube oil supply and oil passages to feed the lube oil to the inner surface of a cylinder in which a piston having a plurality of piston rings reciprocates, wherein are provided a crank angle sensor for detecting engine crank angle, rotation speed detector for detecting engine rotation speed, and a load detector for detecting engine load, and a controller for controlling the electromagnetic valves so that lube oil is injected from the lubricators to spaces formed between piston rings at least once per one reciprocation of piston on the basis of the values detected by the crank angle sensor, rotation detector, and load detector.
By controlling each of the electromagnetic vales so that the lube oil injection ratio(the amount of lube oil supply per an hour/engine load or engine output) calculated on the basis of the amount of lube oil supply and detected engine load coincides with the targeted lube oil injection ratio, preferably a constant lube oil injection ratio all over the operation range of the engine, the amount of lube oil supply can be controlled accurately to supply a minimum amount of lube oil with which the inner surface of cylinder can be lubricated properly in accordance with each operating condition of the engine, and as a result, lube oil consumption can be maintained to a minimum all over the engine operating range.
According to the invention, as lube oil is supplied from the lubricators to spaces formed between piston rings at least once per one reciprocation of piston, the lube oil injected from the lubricators and pooled in the spaces between piston rings is spread by the reciprocation of the piston in the axial direction on the inner surface of cylinder, and a uniform oil film can be formed in a wide range particularly along the axial direction on the inner surface of cylinder not only near the portion where lube oil is injected from the lubricators.
Therefore, lubrication on the inner surface of cylinder is improved, the occurrence of wear and sticking of piston rings can be evaded, and lubrication performance capable of meeting high-powered engines can be achieved. Also an reduction in lube oil consumption can be achieved by the improvement of lubrication.
In the invention, it is preferable to compose as follows:

(1) A first lube oil injection is done when the piston is traveling upward and is at a positioned lower than the lubricators and then a second lube oil injection is done to the spaces between the piston rings in the process of upward traveling of the piston.
By composing like this, By the first method, the firstly injected lube oil injected when the top piston ring is at a position upper than the lubricators is carried upward by the upward travel of the piston to upper portions of the inner surface of the cylinder liner where lubrication condition is severe, and the lube oil injected by the succeeding second lube oil injection from the lubricators and existing in the spaces between piston rings is carried upward along the inner surfaces of the cylinder liner. Therefore, lube oil can spread along the inner surface of cylinder in the axial direction and particularly spreading of lube oil toward upper portions of the inner surface is improved.
(2) A first lube oil injection is done when the piston is traveling downward and is at a positioned upper than the lubricator(s) and then a second lube oil injection is done to the spaces between the piston rings in the process of downward traveling of the piston. By composing like this, the firstly injected lube oil injected when the top piston ring is at a position upper than the lubricators is carried downward by the downward travel of the piston to lower portions of the inner surface of the cylinder liner, and the lube oil injected by the succeeding second lube oil injection from the lubricators and existing in the spaces between piston rings is carried downward along the inner surfaces of the cylinder liner. Therefore, lube oil can spread along the inner surface of the cylinder liner in the axial direction and particularly spreading of lube oil toward lower portions of the inner surface is improved.
By composing like this, lube oil can spread widely in the circumferential direction.
(3) The lubricators are attached to the cylinder such that the injection hole of each of the lubricator directs toward directions circumferential to the inner surface of cylinder so that lube oil is allowed to be injected from the lubricators in directions circumferential to the inner surface of cylinder.
(4) The lubricators are arranged in a plurality of rows along the periphery of a cylinder, and lubricators belonging to at least one row are attached to the cylinder such that the injection hole of each of the lubricators directs toward directions circumferential to the inner surface of cylinder so that lube oil is allowed to be injected from the lubricators in directions circumferential to the inner surface of cylinder.

By composing like this, lube oil is injected from a plurality of lubricators arranged in a plurality of row in the axial direction of cylinder liner and lube oil injected from lubricators belonging to at least a row is directed to the circumferential direction of the inner surface of cylinder, so that spreading of lube oil in the axial direction is improved and lube oil spread widely also in the circumferential direction on the inner surface of cylinder liner can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 is a overall connecting diagram of the first embodiment of the electronic controlled lubricating system of the present invention.
FIG.2 is a control block diagram of the first embodiment of FIG. 1.
FIG.3 is a connecting diagram of the second embodiment corresponding to FIG.1.
FIG.4 is a connecting diagram of the third embodiment corresponding to FIG. 1.
FIG.5 is a connecting diagram of the fourth embodiment corresponding to FIG.1.
FIG.6 is a connecting diagram of the fifth embodiment corresponding to FIG.1.
FIG.7 is a schematic representation of the electromagnetic valve.
FIG. 8 is an overall schematic representation of the sixth embodiment of the cylinder lubricating system of a diesel engine according to the present invention.
FIG.9. is an enlarged detail of a part indicated by Z in FIG.8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will now be detailed with reference to the accompanying drawings. It is intended, however, that unless particularly specified, dimensions, materials, relative positions and so forth of the constituent parts in the embodiments shall be interpreted as illustrative only not as limitative of the scope of the present invention.
FIG.1 is a overall connecting diagram of the first embodiment of the electronic controlled lubricating system of the present invention.
Referring to FIG.1, reference numeral 11 are cylinder liners and two cylinders liners (cylinders) are shown in the drawing. Reference numerals 12a, 12b, 12c, · · · , 12n (omitted) are lubricators for feeding lube oil to the inner surface of each cylinder 11. The plural lubricators 12a, 12b, 12c, · · · , 12n are located along the periphery of each cylinder 11 preferably spaced equidistantly.
Reference numeral 14 is a lube oil pump, 15 is a common lube oil feeding section in which lube oil pressure-fed by the lube oil pump 14 is accumulated. A pressure adjusting valve (not shown in the drawing) is located at an end of the common lube oil feeding section 15, and the lube oil pump 14 feeds the amount of lube oil larger than that supplied for engine lubrication. By circulating lube oil through the common lube oil feeding section 15, the temperature of the lube oil in the common lube oil feeding section 15 becomes uniform.
Reference numerals 16a, 16b, 16c, · · · , 16n are oil passages connecting the common lube oil feeding section 15 to the lubricators 12a, 12b, 12c, · · · , 12n of each cylinder.
Reference numerals 17a, 17b, 17c, · · · , 17n are electromagnetic valves provided at each of the lube oil passages 16a, 16b, 16c, · · · , 16n for opening /closing each of the passages 16a, 16b, 16c, · · · , 16n.
The timing and period of opening of each of these passages 16a, 16b, 16c, · · · , 16n is controlled by each of the electromagnetic valves independently.
Reference numerals 18a, 18b, 18c, · · · , 18n are lube oil flow limiters, each of which are located upstream of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n which are provided to each of the oil passages 16a, 16b, 16c, · · · , 16n for opening /closing each of the lube oil passages 16a, 16b, 16c, · · · , 16n.
In FIG.7 is shown the structure of the electromagnetic valve 17(17a, 17b, 17c, 17d, 17e, · · · , 17n) schematically. In the drawing, reference numeral 172 is a valve case, 173 is a valve seat, 171 is a valve body, 174 is an armature fixed on the valve body 171, 175 is a solenoid, 176 is a valve room. In an electromagnetic valve like this, when the solenoid 175 is energized, the armature 174 is pulled up and the valve body 171 is lifted up by a distance L, and the lube oil supplied to the valve room 176 is sent out to an outlet passage 178. In the drawing, Ga is the air gap between the undersurface of the solenoid 175 and the upper surface of the armature 174 when said lift L is at its maximum.
In the cylinder lubricating system shown in FIG.1, when the lube oil pressure-fed by the lube oil pump 14 and accumulated in the common lube oil feeding section 15 and each of the oil passages 16a, 16b, 16c, · · · , 16n is opened by the actuation of each of the electromagnetic valves 17a, 17b, 17c, 17d, 17e, · · · , 17n each of which are controlled independently by the controller 19, the lube oil accumulated in the common lube oil feeding section 15 is supplied to each of the lubricators 12a, 12b, 12c, · · · , 12n through each of the lube oil passages 16a, 16b, 16c, · · · , 16n to be injected to the inner surface of the cylinder liner 11.
Reference numeral 1 is an engine rotation speed detector for detecting the rotation speed of the engine, 2 is a fuel injection quantity sensor for detecting the quantity of fuel injected into the cylinders, 3 is a crank angle sensor for detecting crank angles of engine, i.e. rotation positions of the crankshaft of engine. Reference numeral 4 is a load detector by which engine load (output) is calculated from the engine rotation speed detected by said engine rotation speed detector 1 and the fuel injection quantity detected by said fuel injection quantity sensor 2.
Reference numeral 21 is oil pressure sensors for detecting the oil pressure of each of said lubricators 12a, 12b, 12c, · · · , 12n. Reference numeral 9 is a specific gravimeter for measuring the specific gravity of the lube oil in the common lube oil feeding section 15 and 10 is a viscosity meter for measuring the viscosity of the lube oil.
The engine rotation speed detected by the engine rotation speed detector 1, the engine load detected(calculated) by the load detector 4, the crank angle detected by the crank angle sensor 3, the oil pressures of the lubricators 12a, 12b, 12c, · · · , 12n detected by the oil pressure sensors 21, the specific gravity of lube oil measured by the specific gravimeter 9 and viscosity of lube oil measured by the viscosity meter 10, are inputted to a calculation part 191 (see FIG.2) for calculating timing and period of opening of each electromagnetic valve.
Further, measured lift L of each of the electromagnetic valves 17a, 17b, 17c, 17d, 17e, · · · , 17n and measured air gap Ga are also inputted to the calculation part 191 for calculating timing and period of opening of electromagnetic valve.
Next, the operation of the first embodiment will be explained referring to FIG. 2 showing the control block diagram, and FIG. 1.
Reference numeral 192 is a setting part of timing and period of opening of each electromagnetic valve, in which target or permissible values of timing and period of opening of each valve corresponding to said detected values are set.
The controller 19 performs calculations and controls on the basis of each value detected and the target or permissible values set in the setting part 192 as follows:

First, when at least one(for example 17a) of the electromagnetic valves connected to the lubricators of which at least two are attached to one cylinder, an electromagnetic valve control part 193 allows the opening period of the other valve or valves connected to the lubricators attached to the concerned cylinder to be lengthened.

By composing like this, by lengthening the opening period of the electromagnetic valve or valves other than the malfunctioning valve of a concerned cylinder, reduction of amount of lube oil supply through the lubricator connected to the malfunctioning valve can be complemented by the other valve or valves not malfunctioning, for each of the electromagnetic valves can be controlled independently. Therefore, even if some of the electromagnetic valves connected to lubricators attached to one cylinder malfunction, enough lube oil can be supplied to the inner surface of said cylinder without influenced by the malfunction.
Further, the calculation part 191 for calculating the timing and period of opening of electromagnetic valve compares the actual amount of lube oil supply, which is calculated as a function of the opening period of electromagnetic valve, or lube oil injection ratio with the minimum amount of lube oil or minimum lube oil injection ratio preset in the opening timing and period setting part 192, and the opening period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n is controlled so that lube oil of an amount larger than the minimum amount is supplied or so that lube oil injection ratio is larger than the minimum lube oil injection ratio. That is, when actual lube oil amount supplied through some of the lubricators or actual injection ratio thereof happens to be smaller than the minimum amount or minimum injection ratio, the opening period of each of electromagnetic valves connected to those some of lubricators is lengthened to increase the amount of lube oil supplied to those lubricators.
By composing like this, when the actual amount of lube oil supply or lube oil injection ratio calculated as a function of the opening period of electromagnetic valve is smaller than the minimum value determined corresponding to engine operation conditions, the opening period of the concerned electromagnetic valve is lengthened to increase the amount of lube oil to be supplied to the cylinder, and when said actual amount is larger than said minimum value determined corresponding to engine operation conditions, the opening period of the concerned electromagnetic valve is shortened to decrease the amount of lube oil to be supplied to the cylinder, so that an amount of lube oil capable of properly lubricating the inner surface of the cylinder 11 can be supplied always in accordance with engine operating conditions.
Further, in the timing and period of opening setting part 192 are set lube oil feeding modes of feeding lube oil from the lubricator 12a, 12b, 12c, · · · , 12n once per a few number of cycles of engine rotation when the engine is operated under low load lower than a certain reference load and feeding lube oil from the lubricator 12a, 12b, 12c, · · · , 12n for every cycle when the engine is operated under high load higher than a certain reference load.
The timing and period of opening calculating part 191 selects a lube oil feeding mode corresponding to the engine rotation speed and engine load inputted from the engine rotation speed detector 1 and load detector 4 respectively from the modes set in the timing and period of opening setting part 192, lube oil is supplied from the lubricators 12a, 12b, 12c, · · · , 12n once per a few number of cycles of engine rotation when the engine is operated under low load lower than a certain reference load, and lube oil is supplied from the lubricators 12a, 12b, 12c, · · · , 12n for every cycle when the engine is operated under high load higher than a certain reference load.
By composing like this, lube oil is supplied in accordance with the detected engine load (or engine rotation speed) such that lube oil is supplied for every cycle when operating at a high load(or high rotation speed) with which lubricating condition on the inner surface of cylinder is severe and lube oil is supplied once for a few number of cycles when operating at a low load (or low rotation speed) with which the lubricating condition is not so severe, so that lubricating oil consumption is decreased particularly in low load operation.
Further, in the timing and period of opening setting part 192 is set relations between reference(target) values of engine load(or rotation speed) and lube oil injection ratio(injection amount of lube oil per hour/engine load or engine output) of the amount of the fuel supplied from the lubricators 12a, 12b, 12c, · · · , 12n.
The timing and period of opening calculating part 191 calculates lube oil injection ratio on the basis of the actual amount of oil supplied to cylinder and the detected engine load, compares the calculated lube oil injection ratio with the reference(target) value of lube oil injection ratio corresponding to the engine load set in the timing and period of opening setting part 192, and the opening periods of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n are controlled according to the result of comparison so that the opening period thereof coincides with said reference (target) value. P14
By composing like this, as the opening period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17niscontrolled so that the lube oil injection ratio calculated on the basis of actual amount of lube oil supply and detected engine load coincide with reference value of lube oil injection ratio targeted, preferably a constant value, in all over the engine operation conditions, lube oil is accurately controlled to be supplied to the inner surface of the cylinder liner 11 by an amount with which proper lubrication is carried out and lube oil consumption can be reduced to a minimum in all over the operation conditions of the engine.
Further, in the timing and period of opening setting part 192 is set a relation between the lube oil feeding pressure to the cylinder liner 11 and the opening period of the electromagnetic valve, i.e. the amount of lube oil supply.
The timing and period of opening calculating part 191 takes out from the timing and period of opening setting part 192 the opening period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n corresponding to the detected lube oil feeding pressure in the common lube oil feeding section 15 sent from the pressure sensor 21.
By composing like this, it is possible to decrease the amount of lube oil supply as the oil pressure increases by shortening the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n, and to increase the amount of lube oil supply as the oil pressure decreases by lengthening the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n, so that the amount of lube oil supply can be maintained always to a targeted amount without influenced by lube oil pressure.
In the timing and period of opening setting part 192 is set a relation between the specific gravity of lube oil and the opening period of the electromagnetic valve, i.e. the amount of lube oil supply such that the opening period is shortened as the specific gravity of lube oil increases and the opening period is lengthened as the specific gravity of lube oil decreases.
The timing and period of opening calculating part 191 takes out from the timing and period of opening setting part 192 the opening period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n corresponding to the detected specific gravity of lube oil inputted from the specific gravimeter.
By composing like this, it is possible to decrease the amount of lube oil supply, i.e. volume flow rate of lube oil as the specific gravity of oil increases by shortening the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n, and to increase the amount of lube oil supply as the specific gravity of lube oil decreases by lengthening the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n, so that the amount of lube oil supply can be maintained always to a targeted amount without influenced by the specific gravity of lube oil.
Further, in the timing and period of opening setting part 192 is set a relation between the viscosity of lube oil and the timing and period of opening of the electromagnetic valve, i.e. the amount of lube oil supply such that the timing is advanced and the period is lengthened as the viscosity of lube oil increases and the timing is retarded and the period is shortened as the viscosity of lube oil decreases.
The timing and period of opening calculating part 191 takes out from the timing and period of opening setting part 192 the timing and period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n corresponding to the detected viscosity of lube oil inputted from the viscosity meter.
By composing like this, it is possible to prevent a decrease in lubricating ability due to viscosity rise by advancing the opening timing resulting in an increase in the amount of lube oil supply, and by lengthening the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n which results in lengthening the period of lube oil being supplied to the inner surface of cylinder liner 11. Therefore, the amount of lube oil supply can be maintained always to a targeted amount.
In the timing and period of opening setting part 192 is set a relation between the lift L of the electromagnetic valve as shown in FIG.7 and the opening period thereof so that the opening period is shortened as the lift L increases in order that the amount of lube oil supply is always constant.
The timing and period of opening calculating part 191 takes out from the timing and period of opening setting part 192 the opening period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n corresponding to the measured value of lift L.
By composing like this, it is possible to shorten the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n when measured value of lift L is larger than the set value of the lift L, and to lengthen the opening period when measured value of lift L is smaller than the set value of the lift L, so that, even if there are variations in valve lifts of electromagnetic valves due to manufacturing errors, the amount of lube oil supply can be maintained always to a targeted amount without influenced by said errors.
In the timing and period of opening setting part 192 is set a relation between the air gap Ga of the electromagnetic valve as shown in FIG.7 and the opening period thereof so that the opening period is shortened as the air gap Ga increases in order that the amount of lube oil supply is always constant.
The timing and period of opening calculating part 191 takes out from the timing and period of opening setting part 192 the opening period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n corresponding to the measured value of air gap Ga.
By composing like this, it is possible to shorten the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n when measured value of air gap Ga is larger than the set value of the air gap Ga, and to lengthen the opening period when measured value of lift L is smaller than the set value of the air gap Ga, so that, even if there are variations in sir gaps of electromagnetic valves due to manufacturing errors, the amount of lube oil supply can be maintained always to a targeted amount without influenced by said errors.
In the timing and period of opening setting part 192 is set a relation between the sulfur concentration in fuel and the opening period of the electromagnetic valve so that the opening period is determined to allow a minimum amount of lube oil necessary to neutralize the sulfur to flow.
The timing and period of opening calculating part 191 takes out from the timing and period of opening setting part 192 the opening period of each of the electromagnetic valves 17a, 17b, 17c, · · · , 17n corresponding to the sulfur concentration in fuel.
By composing like this, it is possible to suppress increasing of sulfur which deteriorate lubrication on the inner surface of cylinder by controlling the opening period of the electromagnetic valves 17a, 17b, 17c, · · · , 17n and maintaining a minimum flow of lube oil necessary to neutralize the sulfur in fuel.
In FIG. 3 to FIG. 5 showing the second to fourth embodiments, a variety of connections between the electromagnetic valves 17 and the lubricators 12 are shown.
In the second embodiment shown in FIG.3, a plurality of the lubricators 12 are attached to one cylinder as shown by 12a, 12b, 12c, 12d, 12e, · · · , 12n , and oil passages connecting to the lubricators 12 are composed to consist of main passages 161, 162, 163, and 164 and branch oil passages 16a, 16b, 16c, 16d, 16e, · · · , 16n (corresponding to the oil passages in the first embodiment) branching from the main passages 161, 162, 163, and 164 to be connected to each of the lubricators 12a, 12b, 12c, 12d, 12e, · · · , 12n. An electromagnetic valve 17 is provided to each of main oil passages, that is, a valve 17A and a valve 17B are provided to the main oil passages 161, and 162 respectively and another valve 17A and valve 17B are provided to the main oil passages 163 and 164 respectively. Thus, by controlling a plurality of lubricator 12 by one electromagnetic valve 17, the number of electromagnetic valves 17 is reduced.
Reference numeral 18A is a lube oil flow limiter located upstream of the electromagnetic valve 17A, and 18B is a lube oil flow limiter located upstream of the electromagnetic valve 17B. The composition other than the points mentioned above is the same as that of the first embodiment shown in FIG.1 and the same component is indicated by the same reference numeral.
By the way, detectors and sensors shown in FIG. 1 are omitted in FIG.3.
In the third embodiment shown in FIG.4, the branch oil passages 16a, 16b, 16c, 16d, 16e, · · · , 16n connected to the lubricators 12a, 12b, 12c, 12d, 12e, · · · , 12n arranged along the periphery of one cylinder liner 11 are connected alternately to the main oil passages 161, 162, 163, and 164. The electromagnetic valves 17A and 17B provided to the main oil passages 161 and 162 control respectively the lube oil flow to the alternately disposed lubricators, that is, for example, the valves 17A controls the lubricators 12a, 12c, and 12d, and valves 17B controls the lubricators 12b, 12d, and 12n. By this, controlling of lube oil supply is evened along the circumferential direction of the cylinder.
The composition other than the points mentioned above is the same as that of the first embodiment shown in FIG.1 or the second embodiment shown in FIG.3 and the same component is indicated by the same reference numeral.
By the way, detectors and sensors shown in FIG. 1 are omitted in FIG.3.
In the fourth embodiment shown in FIG.5, a plurality of the lubricators 12 are attached to one cylinder as shown by 12a, 12b, 12c, 12d, 12e, · · · , 1 2 n , and oil passages connecting to the lubricators 12 are composed to consist of main passages 161, 162, 163, and 164 and branch oil passages 16a, 16b, 16c, 16d, 16e, · · · , 16n (corresponding to the oil passages in the first embodiment) branching from the main passages 161, 162, 163, and 164 to be connected to each of the lubricators 12a, 12b, 12c, 12d, 12e, · · · , 12n, as is in the case of the second embodiment. In this fourth embodiment, a plurality of controllers 19A and 19B instead of a single controller 19 in the second embodiment, and the electromagnetic valves 17A and 17B are controlled independently by the controller 19A, and 19B respectively.
The composition other than the points mentioned above is the same as that of the first embodiment shown in FIG. 1 or the second embodiment shown in FIG.3 and the same component is indicated by the same reference numeral.
By the way, detectors and sensors shown in FIG. 1 are omitted in FIG.5.
In the fifth embodiment shown in FIG.6, a return pipe 23 and a pressure regulation valve 22 are provided to allow the lube oil in the common lube oil feeding section 15 to return to the lube oil pump 14 so that lube oil temperature in the common lube oil feeding section 15 is even along the widely extending section 15 by heating the lube oil in the common lube oil feeding section 15 by the lube oil in the return pipe 23.
The composition other than the points mentioned above is the same as that of the first embodiment shown in FIG.1 or the second embodiment shown in FIG.3 and the same component is indicated by the same reference numeral.
By the way, detectors and sensors shown in FIG. 1 are omitted in FIG.6.
In each of the embodiments, the opening area of each of the electromagnetic valves 17(17a, 17b, 17c, · · · , 17n) is larger than the sum of the passage area of the lubricators connected to the concerned electromagnetic valve (for example, In FIG.4, the opening area of the valve 17A is larger than the sum of the passage area of the lubricator 12a, 12b, and 12c) .
By this, even if opening areas varies among a plurality of electromagnetic valves due to the variations of valve lifts, required amount of lube oil supply through the lubricators can be obtained without influenced by the variations of valve lifts of the electromagnetic valves.
FIG.8 is an overall schematic representation of the sixth embodiment of the cylinder lubricating system of a diesel engine according to the present invention, and FIG. 9. is an enlarged detail of a part indicated by Z in FIG.8.
In FIG.8 and FIG.9, reference numeral 11 is a cylinder liner (cylinder) , 51 is a piston which reciprocates along the inner surface 11a of the cylinder liner 11, 52 are a few number of piston rings received in ring groove of the piston 52 (in the drawing, four rings are provided). Reference numeral 53 are spaces between the piston rings 52 formed between the inner surface of the cylinder liner 11 and the outer surface of the piston 51. Reference numeral 56 is a cylinder cover, 55 is an exhaust valve, and 58 is a combustion chamber. The composition mentioned above is the same as that of prior art.
Reference numeral 12 are lubricators (lube oil injectors) for injecting lube oil to the inner surface 11a of the cylinder liner 11. Two lubricators 12 are recognized in the drawing along the axial direction of the cylinder liner 11, and although not shown in the drawing, a plurality of lubricators are arranged along the periphery of the cylinder liner 11. The lubricators 12 are conventional ones used in large diesel engines(detailed explanation is omitted) and they may be arranged in a single row or in three or more rows along the periphery of one cylinder.
Reference numeral 14 is a lube oil pump, 15 is a common lube oil feeding section where the lube oil pressure-fed by the lube oil pump 14 is accumulated. Reference numeral 156 are oil passages connecting the common lube oil feeding section 15 to the lubricators 12 of each cylinder, 70 are electromagnetic valves provided to each of the oil passages 156 for opening/closing the oil passages 156.
Reference numeral 1 is an engine rotation speed detector for detecting the rotation speed of the engine, 4 is a load detector for detecting engine load (fuel injection quantity, etc.), 3 is crank angle sensor for detecting crank angles of engine, i.e. rotation positions of the crankshaft of engine .
Reference numeral 19 is a controller, to which are inputted the crank angle detected by the crank angle sensor3, the engine rotation speed detected by the engine rotation speed detector 1, and the engine load detected by the load detector 4. The controller 19 controls the timing and period of opening of each of the electromagnetic valves 70 on the basis of those detected values to adjust the timing and quantity of lube oil injection from each of the lubricators(injectors) 12.
Each of the electromagnetic valves 70 is controlled independently by the controller 19 to adjust the timing and period of opening thereof.
When the diesel engine provided with the fifth embodiment is in operation, the lube oil pressure-fed by the lube oil pump 14 is accumulated in the common lube oil feeding section 15. When each of the oil passages 156 is opened by each of the electromagnetic valves 70 controlled independently by the controller 19, the lube oil accumulated in the common lube oil feeding section 15 is supplied to the lubricators 12 through the oil passages 156 and injected to the inner surface of the cylinder liner 11 from each of the lubricators 12.
The controller 19 controls the timing and period of opening of each of the electromagnetic valves 70 on the basis of the detected values of crank angle, engine rotation speed, and engine load by the first or second method described in the following.
The controlling by the first method is done as follows:

When the piston 51 travels upward, a first lube oil injection is done from the lubricators 12 arranged in two rows along the periphery of the cylinder 11 when the top piston ring(uppermost piston ring of the four piston rings 52 in the drawing) is at a position upper than the lubricators 12 (at a position upper than the upper lubricators in the case the lubricators are arranged in two rows as this example) , then a second lube oil injection is done in the process of upward travel of the piston 51. As there are three spaces 53 between piston rings in the example, it is intended to inject lube oil at least to the uppermost space between piston rings, and lube oil is injected to other spaces between piston rings by either of the lubricators arranged in two rows.

By the first method, the firstly injected lube oil injected when the top piston ring is at a position upper than the lubricators 12 (at a position upper than the upper lubricators in the case the lubricators are arranged in two rows as this example) is carried upward by the upward travel of the piston 51 to upper portions of the inner surface of the cylinder liner 11 where lubrication condition is severe, and the lube oil injected by the succeeding second lube oil injection from the lubricators 12 and existing in the spaces 53 between piston rings is carried upward along the inner surfaces of the cylinder liner 11. Therefore, lube oil can spread along the inner surface 11a of the cylinder liner in the axial direction and particularly spreading of lube oil toward upper portions of the inner surface 11a is improved.
The controlling by the first method is done as follows:
When the piston 51 travels downward, a first lube oil injection is done from the lubricators 12 arranged in two rows when the bottom piston ring(lowermost piston ring of the four piston rings in the drawing) is at a position upper than the lubricators 12(at a position upper than the lower lubricators in the case the lubricators are arranged in two rows as this example), then a second lube oil injection is done in the process of downward travel of the piston 51. As there are three spaces 53 between piston rings in the example, it is intended to inject lube oil at least to the lowermost space between piston rings, and lube oil is injected to other spaces between piston rings by either of the lubricators arranged in two rows.
By the second method, the firstly injected lube oil injected when the top piston ring is at a position upper than the lubricators 12 (at a position upper than the lower lubricators in the case the lubricators are arranged in two rows as this example) is carried downward by the downward travel of the piston 51 to lower portions of the inner surface of the cylinder liner 11 , and the lube oil injected by the succeeding second lube oil injection from the lubricators 12 and existing in the spaces 53 between piston rings is carried downward along the inner surfaces of the cylinder liner 11. Therefore, lube oil can spread along the inner surface 11a of the cylinder liner in the axial direction and particularly spreading of lube oil toward lower portions of the inner surface 11a is improved.
The lubricators 12 arranged along the periphery of the cylinder liner 11(arranged in two rows in this example) may be attached to the cylinder such that the injection hole of each of the lubricators is directed to directions circumferential to the inner surface 11a of cylinder liner so that lube oil spreads widely in the circumferential direction of the inner surface 11a of cylinder.
When the lubricators 12 are arranged in a plurality of rows(two rows in this example) along the periphery of the cylinder liner 11, the injection hole of lubricators belonging at least to a row may be attached to the cylinder liner 11 such that the injection hole of each of the lubricators is directed to directions circumferential to the inner surface 11a of cylinder liner is directed. In this case also lube oil can be spread widely in the circumferential direction of the inner surface 11a of cylinder.
By this, lube oil is injected from a plurality of lubricators arranged in a plurality of row in the axial direction of cylinder liner 11 and lube oil injected from lubricators belonging to at leas a row is directed to the circumferential direction of the inner surface of cylinder, so that the spreading of lube oil in the axial direction is improved and lube oil spreads widely also in the circumferential direction on the inner surface 11a of cylinder liner.
According to the sixth embodiment, lube oil is injected from the lubricators 12 to the spaces 53 between piston rings at least once per one reciprocation of the piston 51, and the lube oil pooled in the spaces 53 between piston rings is transferred in the axial direction of the inner surface 11a of cylinder liner, so that an oil film of even thickness is formed on a wide range of the inner surface 11a of cylinder, particularly over a wide range along the axial direction thereof not only near portions where lube oil is injected from the lubricators.
By this, lubrication of the inner surface 11a of cylinder liner is improved, and the occurrence of wear or sticking of piston rings 52 can be evaded. Also, lubrication oil consumption is decreased due to the improved lubrication 12.
As has been described in the foregoing, according to the cylinder lubricating system of the present invention, it becomes possible to supply lube oil of required amount at required timing to each lubricator, that is, to each portion of the inner surface of cylinder independently, and normal supply of lube oil is possible even when malfunction occurs in some of the lubricators including magnetic valves to open / close the oil passages to supply lube oil to the lubricators. Further, the timing and amount of lube oil supply can be adjusted even in engine operation in accordance with varying factors such as properties of lube oil, lube oil pressure, etc. In addition, lube oil consumption can be reduced.
Further, according to the present invention, it becomes possible to supply lube oil of required amount at required timing to each lubricator, that is, to each portion of the inner surface of cylinder independently, and supply amount of lube oil or lube oil injection ratio can be controlled so that a minimum amount of lube oil required to maintain good lubricating condition in the inner surface of cylinder to positively evade the occurrence of wear or sticking of piston or piston rings is supplied on the inner surface of cylinder. Therefore, lube oil consumption can be reduced compared with prior art of cylinder lubricating system in which the timing and amount of lube oil supply to a plurality of lubricators are adjusted uniformly not independently.
The timing and supply amount or injection ratio of lube oil can be adjusted easily even in engine operation.
Further, according to the invention, as lube oil is supplied from lubricators to spaces between piston rings at least once per one reciprocation of piston, the lube oil supplied and pooled in the spaces between piston rings is carried in the axial direction on the inner surface of cylinder and an oil film of even thickness is formed on a wide range of the inner surface 11a of cylinder, particularly over a wide range along the axial direction thereof not only near portions where lube oil is injected from the lubricators.
By this, lubrication of the inner surface of cylinder liner is improved, and the occurrence of wear or sticking of piston rings can be evaded. Also, lubrication oil consumption is decreased due to the improved lubrication.

Claims

An internal combustion engine provided with a lubricating system in which lube oil pressure-fed by a lube oil pump (14) is accommodated in a common lube oil feeding section (15), the lube oil contained in said common lube oil feeding section is supplied to a plurality of lubricators (12a, b, c...n) through lube oil passages (16a, b, c...n) connecting said common lube oil feeding section to said lubricators and injected to the inner surfaces of cylinders (11) of the engine by said lubricators, wherein are provided a plurality of electromagnetic valves (17a,b,c...n) for opening or closing each of said lube oil passages independently, and a controller (19) for controlling the timing and period of opening of each of said electromagnetic valves independently, and wherein said controller calculates lube oil injection ratio, i.e. the injection amount of lube oil per hour/engine load or engine output, on the basis of the amount of lube oil supply calculated as a function of the opening of the electromagnetic valves and engine load calculated from the detected engine rotation speed and amount of fuel input, and controls the opening period of said electromagnetic valves so that said calculated lube oil injection ratio coincides with a lube oil injection ratio determined beforehand.
The internal combustion engine provided with a lubricating system according to claim 1, wherein said controller controls said electromagnetic valves so that when at least one among two or more of said electromagnetic valves which are attached per cylinder malfunctions, the opening period of other valve or valves is lengthened.
The internal combustion engine provided with a lubricating system according to claims 1 or 2, wherein said controller controls the opening period of said electromagnetic valves so that the amount of oil supply which is determined as a function of the opening period of the electromagnetic valves, or lube oil injection ratio calculated on the basis of said amount of lube oil supply and engine load, is larger than predetermined minimum amount of lube oil supply or minimum lube oil injection ratio.
The internal combustion engine provided with a lubricating system according to claims 1, 2 or 3, wherein an engine rotation speed detector (1) for detecting the rotation speed of the engine and a fuel input sensor (2) for detecting the amount of fuel input are provided, said controller calculates engine load on the basis of the engine rotation speed and amount of fuel input detected and controls the opening /closing of said electromagnetic valves so that lube oil is injected from said lubricators every cycle when the engine is operated at a high load higher than a certain load, and once per a few number of cycles when the engine is operated at a low load lower than said certain load.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 4, wherein a specific gravimeter (9) is provided to said common lube oil feeding section, and said controller controls said electromagnetic valves so that the opening period thereof coincides with a value predetermined in correspondence with the value of specific gravity of lube oil inputted beforehand in the controller from said specif ic gravimeter or the value of actual specific gravity detected by said specific gravimeter.
The internal combustion engine provided with a lubricating system according to claim 5, wherein said controller controls said electromagnetic valves so that the opening timing and period thereof coincides with values predetermined in correspondence with the value of viscosity of lube oil inputted beforehand in the controller from a viscosity meter (10) attached to the common lube oil feeding section or the value of actual viscosity detected by said specific gravimeter.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 6, wherein a pressure detector (21) or a temperature detector is provided to said common lube oil feeding section, and said controller controls said electromagnetic valves so that the opening period thereof coincides with periods predetermined in correspondence with the pressure or temperature of lube oil in the common lube oil feeding section detected by and inputted from said pressure detector or temperature detector.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 7, wherein said controller controls said electromagnetic valves so that the opening period thereof coincides with periods predetermined in correspondence with the lift (L) thereof which is predetermined or measured.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 8, wherein said controller controls said electromagnetic valves in correspondence with the predetermined or measured value of an air gap (Ga) of said electromagnetic valve.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 9, wherein a plurality of lubricators are provided per cylinder, each of said oil passages is connected to each of said lubricators, and each of said electromagnetic valves is provided to each of said oil passages.
The internal combustion engine provided with a lubricating system according to claim 10, wherein a plurality of lubricators are provided per cylinder, lube oil passages consist of a main passage (161-164) and branch passages (16a, b, c...n) branching from said mainpassage and connecting to each of said lubricators respectively, said electromagnetic valve is provided to the main oil passage, and a single electromagnetic valve (17) presides lube oil supply to a plurality of lubricators.
The internal combustionengineprovidedwitha lubricating system according to claim 11, wherein the branched passages branching from each of the main passages are connected to lubricators located alternately along the periphery of cylinder, whereby even if one of the electromagnetic valves malfunctions lube oil can be supplied to the lubricators provided all around the periphery of cylinder excepting the lubricators connected to the malfunctioned electromagnetic valves.
The internal combustionengineprovidedwitha lubricating system according to any of claims 1 to 12, wherein a plurality of lubricators are provided per cylinder and a plurality of controllers (19A, B) are provided to control one or a plurality of said electromagnetic valves.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 13, wherein a pressure regulating valve (22) is provided to an end part of the common lube oil feeding section, and the lube oil pump discharges more lube oil than the amount injected to the cylinders of the engine allowing lube oil in the common lube oil feeding section to circulate and maintaining the temperature of the lube oil in the common lube oil feeding section at uniform temperature.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 14, wherein a return pipe (23) is provided along the common lube oil feeding section, and heat exchange is possible between the lube oil in the common lube oil feeding section and that in the return pipe.
The internal combustion engine provided with a lubricating system according to any of claims 1 to 15, wherein the opening area of each of the electromagnetic valves is larger than the sum of the passage area of the lubricators connected to the concerned electromagnetic valve.
The internal combustion engine provided with a cylinder lubricating system according to any of claims 1 to 16, wherein, wherein there are provided a crank angle sensor (3) for detecting engine crank angle, a rotation speed detector (1) for detecting engine rotation speed, a load detector (4) for detecting engine load, and a controller (19) for controlling the electromagnetic valves so that lube oil is injected from the lubricators to spaces formed between piston rings (52) of a piston (51) reciprocating in the cylinder (11) at least once per one reciprocation of the piston on the basis of the values detected by the crank angle sensor, rotation speed detector, and load detector.
A method of supplying lube oil to cylinders in a system inwhich the lube oil pressure-fedbya lube oil pump is supplied to lubricators attached to a cylinder through electromagnetic valves for adjusting the timing and amount of lube oil supply and oil passages to feed the lube oil to the inner surface of a cylinder in which a piston having a plurality of piston rings reciprocates, wherein lube oil is injected from the lubricators to spaces formed between the piston rings at least once per one reciprocation of piston, and wherein a lube oil injection ratio is calculated, i.e. the injection amount of lube oil per hour/engine load or engine output, on the basis of the amount of lube oil supply calculated as a function of the opening of the electromagnetic valves and engine load calculated from the detected engine rotation speed and amount of fuel input, and the opening period of said electromagnetic valves is controlled so that said calculated lube oil injection ratio coincides with a lube oil injection ratio determined beforehand.
The method of supplying lube oil to cylinders according to claim 18, wherein a first lube oil injection is done when the piston is traveling upward and is at a position lower than the lubricator (s) and then a second lube oil injection is done to the spaces between the piston rings in the process of upward traveling of the piston.
The method of supplying lube oil to cylinders according to claim 18, wherein a first lube oil injection is done when the piston is traveling downward and is at a position higher than the lubricator(s) and then a second lube oil injection is done to the spaces between the piston rings in the process of downward traveling of the piston.
The method of supplying lube oil to cylinders according to claim 18, 19 or 20, wherein the lubricators are attached to the cylinder such that the injection hole of each of the lubricators is directed toward directions circumferential to the inner surface of cylinder so that lube oil is allowed to be injected from the lubricators in directions circumferential to the inner surface of cylinder.
The method of supplying lube oil to cylinders according to claim 18, 19 or 20, wherein the lubricators are arranged in a plurality of rows along the periphery of a cylinder, and lubricators belonging to at least one row are attached to the cylinder such that the injection hole of each of the lubricator directs toward directions circumferential to the inner surface of cylinder so that lube oil is allowed to be injected from the lubricators in directions circumferential to the inner surface of cylinder.