JPS59168213A - Lubricating apparatus for reciprocating piston engine - Google Patents

Abstract

PURPOSE:To make bearings compact and to reduce the weight of an internal combustion engine, by supplying high-pressure oil to the bearings from th outside so as to keep the load carrying capacity of bearings and a sufficient thickness of oil film at the time when the bearing load is high, taking the periodicity of operation of a reciprocating internal combustion engine into consideration. CONSTITUTION:An inlet port is formed respectively in the surface of a crank- shaft 7 at the portions thereof journaled by adjacent main bearings 73a, 73b, and oil feed passages 74 are extended from these two inlet ports to a crank pin bearing 62 for a cylinder located between the two main bearings 73a and 73b. Further, there is provided a pump 8 which is driven synchronously with the crankshaft 7 for delivering high-pressure oil for a prescribed crank-angle period. An oil feed port 75 is opened in each of the main bearings 73, and independent oil feed lines 81 for supplying high-pressure oil are connected between the oil feed ports 75 and the pump 8. With such an arrangement, aimed objects of this invention can be achieved by supplying high-pressure oil from the outside to keep the load carrying capacity of the bearings and a sufficient thickness of oil film at the time when the bearing load is high.

Description

[Detailed description of the invention] The present invention relates to a lubricating device for a reciprocating piston engine (1) Ru.

FIG. 1 is a sectional view showing the main parts of a conventional multi-cylinder internal combustion engine. In the figure, 1 is the cylinder block of the engine, 2
is the cylinder, and 3 is the cylinder head.

4 is the piston, 5 is the piston pin, and 6 is the connecting rod.

61 is a connecting rod small end bearing, that is, a piston pin bearing.

62 is the same big end bearing, that is, the crank bottle bearing, 7 is the crankshaft, and 71 is the crank main! It is an Iuit receiver and is provided between each cylinder, that is, between each crank throw and at both ends of the cylinder row. 72 is a fuel supply passage.

Generally, in the bearings of an internal combustion engine, lubricating oil supplied from the crank main bearing 71 passes through oil supply passages provided in the crankshaft 7 and the connecting rod 6 to the bearings of various parts, that is, the main bearing 71. It is supplied to the crankbin bearing 62 and the piston bearing 61, and receives the pressure inside the cylinder 2 applied via the stopper stone 4, which generates oil film pressure by the rotation and rocking of the shaft.

FIG. 5 shows this situation, which is indicated by a solid line in FIG. In the figure, the upper part shows the change in the gas pressure r2) in the cylinder depending on the crank angle, and generally the pressure is highest near the top dead center (TDC) of the piston, pushing the piston down. As a result, oil and film pressure in each bearing is generated as shown in the middle row, and in response to this force, the work of the reciprocating movement of the piston is smoothly converted into rotational movement of the crankshaft.

The change in the oil film thickness on the bearing at this time is as shown by the lower solid line, where the piston gradually becomes thinner after it passes the top dead center, reaches the minimum oil film thickness, and then recovers again when the cylinder pressure decreases. Follow.

However, the above method has the following drawbacks.

Due to the above-mentioned action, the internal combustion engine converts the reciprocating motion of the piston into rotational motion using the crank.

As shown in FIG. 5, the period when the bearing load is high is around 30° to 60' in terms of crank angle. On the other hand, conventional bearings rely solely on the formation of an oil film due to the wedge effect of the bearing, and therefore have a sufficiently high load capacity. ensured and maintained reliability.

As a result, the bearings of the two engines become larger, which increases the overall size of the engine, increases weight, and increases costs.In addition, the bearing area is large and the circumferential speed of the bearings increases, resulting in friction loss in the bearings. The disadvantage is that it becomes large.

In particular, in highly supercharged internal combustion engines, as the pressure inside the cylinder increases significantly, it becomes necessary to make the bearings larger, which makes it impossible to achieve sufficient weight reduction of the engine, and the loss of horsepower at the bearings also increases. death.

The drawback is that the efficiency of the engine cannot be fully realized due to high supercharging.

An object of the present invention is to focus on the above points, and to provide a lubricating device that can realize a lightweight and compact internal combustion engine and a significant reduction in mechanical loss. In a lubricating device for a reciprocating piston engine having main bearings between the throws and at both ends, the above-mentioned amphiphilic bearings are clamped to the respective inlets provided on the surface of the crankshaft portion that slides on the adjacent amphiphilic bearings. an oil supply passage for each cylinder formed between the cylinder and a crank bin bearing; an oil supply hole provided in each of the main bearings and connected to the entrance of the oil supply passage for each cylinder only during a predetermined crank angle;
The oil supply hole is provided with a high-pressure oil supply device that supplies high-pressure oil only during the period of the predetermined crank angle.

In other words, focusing on the periodicity of the operation of a reciprocating internal combustion engine, high-pressure oil is applied from the outside during periods of high load to maintain sufficient bearing load capacity and sufficient oil film thickness during periods of high bearing load. A lubricating oil system was constructed to periodically supply oil from the main bearings on both sides of the cylinder.

The present invention is applicable to various reciprocating internal combustion engines (diesel gasoline) and compressors, and rotary piston internal combustion engines and compressors.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a sectional view showing the main parts of an internal combustion engine equipped with a lubricating device according to an embodiment of the present invention.

In the figure, 1 is a cylinder block, 2 is a cylinder, and 3 is a cylinder block.
is the cylinder head, 4 is the piston, 5 is the piston pin,
6 is a connecting rod, 61 is a piston pin bearing, 62 is a crank pin bearing, and 7 is a crankshaft.

A main bearing 73 is provided between each cylinder, that is, between each crank throw and at both ends of the cylinder row.

74 is an oil supply passage, which connects adjacent main bearings 73a and 73b.
An inlet is provided on each surface of the crankshaft portion on which the crankshaft slides, and the above-mentioned amphiphilic bearing 73a is opened from both inlets.

This is an oil supply passage for each cylinder that reaches the crank bin bearing 62 of the cylinder sandwiched by the cylinders 73b. Of course, crankbin bearing 6
2, the piston bearing 61 is supplied with oil in the same manner as the conventional one.

A jerk pump 8 is driven in synchronization with the crankshaft 7, and is a positive displacement high-pressure oil supply pump that delivers high-pressure oil for a predetermined period of the crank angle. Reference numeral 81 is an oil supply pipe connecting the pump 8 and the main bearing 73.

Each main bearing 73 has an oil supply hole 75 opened therein.

Each oil supply hole 75a, 75b is provided with an oil supply line 81 for independently supplying high pressure oil between the high pressure oil supply bong 7°8.

The oil supply hole 75 meets or connects with the entrance of the oil supply passage 74 only during a predetermined period (200 to 60 degrees in crank angle) near the piston top dead center with respect to the piston movement of the cylinder,
During this period, they are arranged as shown in FIG. 6 so that they do not meet with the inlets of the fuel supply passages 74' and 74'' belonging to adjacent cylinders.

The jerk-type high-pressure oil pump 8 has a number of plunger pumps corresponding to the main bearings 73 of one engine, and the main bearings 73 in which the oil supply holes 75 connected via the oil supply line 81 are located are adjacent to each other. The piston movement of the cylinder is controlled by a cam, as shown in the figure, so that high pressure oil is supplied only during a predetermined period (20° to 600° in crank angle) near the top dead center of the piston. In other words, in a plunger pump compatible with a main bearing having cylinders on both sides, a predetermined Jul' near the top dead center on both sides
Accordingly, high pressure oil is supplied twice during one cycle.

The operation in the case of the above configuration will be described.

As shown in Fig. 7, the changes in the oil supply pressure of each plunger pump are determined by the deviation on both sides of the main bearing 73 to which the oil hole 75 belongs and the compression top death of the n+1st shilling. Although the pressure is increased to correspond to the vicinity of the point, the entrance of the oil supply passage 74 corresponding to the nth shilling meets the oil supply hole 75 only once in one cycle as shown by the solid line.

As a result, when the piston 4 of the n-th cylinder rises to near the compression top dead center, the two corresponding plunger pumps of the high-pressure oil supply pump 8 operate, and high-pressure lubricating oil passes through the oil supply pipe 81 to the main bearings 73a, 73b. High pressure oil is supplied directly to the main bearings on both sides of the cylinder.
At the same time as paying.

High pressure oil is also supplied to the piston pin bearing 61 through the oil supply passage 74 and through the oil passage in the crank pin bearing 62 and the connecting rod 6. As a result, high-pressure oil enters the sliding portion of each pusher 1, lifting the shaft and thickening the oil film.

After that, the oil supply to the plunger pump is stopped and the entrance of the oil supply passage 74 is also closed, but a thick oil film has already been formed and the pressure inside the cylinder 2 has decreased, so a sufficiently thick oil film is maintained. .

This is illustrated in diagram v5. In the same figure, the dashed line shows the invention, which is achieved by supplying high-pressure oil around the second dead center as shown in the middle row.

As shown in the lower diagram, the oil film on the bearing rapidly thickens, and even after the oil supply is stopped, a sufficient oil film is maintained due to the oil film forming ability due to the rotation of the shaft and the squeezing effect.

The above case has the following effects.

Due to the above-mentioned effects, the load capacity of the bearing can be increased over a wide range, so that the bearing can be made more compact.

As a result, it is possible to make the internal combustion '+JA gate smaller, lighter, and higher in output. Dimensions. The smaller the bearing area, the better the mechanical efficiency.

Furthermore, since refueling is carried out for a short period of time, the amount of #oil is slightly reduced, resulting in effects such as a reduction in the capacity of auxiliary equipment.

FIG. 3 is an explanatory diagram showing the main parts of another embodiment according to the present invention.

The structure of the engine body is the same as that shown in FIG. 2 of the previous embodiment, but the high pressure oil supply system is changed as shown in FIG. 3.

In the figure, the main bearing 73a shown in FIG.

73b and the oil supply passage 74 are supplied to the high pressure oil pressure accumulator 10.
The structure is such that oil supply pipes 91 are connected to each main bearing via a high pressure conduit 101 and a distributor 9.

The distributor 9 in FIG. 3 is an example of a distributor having a distribution shaft that rotates in synchronization with the rotation of the crankshaft, and is intended to distribute high-pressure oil at a predetermined time for a predetermined period as in the previous embodiment. The aperture characteristics that supply the bearing are given.

Regarding the operation, this device stores a predetermined amount of high-pressure oil using a high-pressure pump (not shown) installed separately in the pressure accumulator.
From these conduits]01, it is supplied into the shaft of the distributor 9, and by rotation of the distribution shaft, it is delivered to the bearing of the target cylinder at a predetermined time (near the dual point of the piston) for a predetermined period (20°~
60°).

The effect is the same as in the previous embodiment.

FIG. P4 is an explanatory diagram showing a main part of still another embodiment according to the present invention.

The structure of the engine main body is the same as that shown in FIG.

In the figure, the device comprises a distributor 11 with an electrically driven valve.

A pressure accumulator 12, which is supplied from a separately provided high-pressure pump (not shown), enters the distribution pipe 11 through a high-pressure conduit 121.Predetermined pressure is supplied by electrically driven valves that operate corresponding to each cylinder of the engine. High pressure oil is supplied to the main bearings 73a, 73b and the oil supply path 74 shown in FIG. 2 through the oil supply pipe 111 for a predetermined period.

In the case of an electrically driven valve, the solenoid valve sends a current to the electric wire 112 controlled by an electrical control system (not shown) that has separate valve opening timing and period depending on the rotation angle of the engine. It is controlled by flowing the water.

Regarding the operation, in this embodiment, the high-pressure oil from the pressure accumulator 12 is controlled at a predetermined time and at a predetermined time in the corresponding cylinder by a solenoid valve that opens and closes with a current controlled by a separate electrical control system (not shown). Period main bearing 73a,
7.3b, by supplying oil to the oil supply path 74, the fifth
The same effect as that described in the previous embodiment with reference to the figures is performed.

The effect is the same as in the previous embodiment.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of a conventional multi-cylinder internal combustion engine, FIG. 2 is a sectional view showing the main parts of an internal combustion engine equipped with a lubricating device according to an embodiment of the present invention, and FIG. FIG. 4 is an explanatory diagram showing the essential parts of another embodiment according to the present invention, FIG. 5 is an explanatory diagram showing the essential parts of still another embodiment according to the present invention, and FIG. 5 shows changes in cylinder internal pressure, bearing oil pressure, and oil film thickness. Diagram showing the state, No. 6
The figure is a sectional view taken along the line ■--■ in FIG. 2, and FIG. 7 is a diagram showing the relationship between the opening area of the oil supply passage inlet and the oil supply pressure. 7...Crankshaft, 8...High pressure oil pump, 61...
・Piston pin bearing, 62...crank pin bearing. 73a, 73b...Main bearing, 74...Oil supply passage. 75a, 75b...oil supply holes. 10 BDCTDCCBDC θ Climax 7511 to 104-7177ffi

Claims (1)

[Claims] 1. In a lubricating system for a reciprocating piston engine that has a main bearing between each crank throw and at both ends of the crankshaft, an inlet and A refueling passage for each cylinder is formed between the crank bin bearing of the cylinder sandwiched between the two main bearings, and a period of a predetermined crank angle is provided at the entrance of the refueling passage for each cylinder provided in each of the main bearings. 1. A lubricating device for a reciprocating piston engine, comprising: an oil supply hole that is connected only inside the oil supply hole; and a high pressure oil supply device that supplies high pressure oil to the oil supply hole only during the period of the predetermined crank angle.