JPS59147811A - Lubricating device for reciprocating engine - Google Patents

Abstract

PURPOSE:To properly lubricate a reciprocating engine while keeping oil film thickness satisfactory in a period when the bearing load is high, by providing an independent oiling passage for each cylinder and providing an oiling device for periodically supplying high pressure oil to said oiling passage while interlocking with a crank shaft. CONSTITUTION:A high pressure oiling pump 8 is provided with plunger pumps in the number corresponding to the number of the engine cylinders, and each of said plungers is connected to an oiling passage 74 of a main bearing 73 via an oiling pipe 81 in correspondence with an engine cylinder 2. Moreover, for timing of the pump 8 when it sends water, a crank shaft 7 and a pump driving shaft are connected to each other such that the point of said timing corresponds to the neighborhood of the compression top dead point of the cylinder 2. Therefore, when a piston 4 rises near the top dead point, a corresponding plunger of the oiling pump 8 is operated, high pressure lubricating oil is supplied to a main bearing 73 through the oiling pipe 81, reaching a crank pin bearing part 62 through the oiling passage 74 and a piston pin bearing part 61 through an oil passage in the connecting rod 6.

Description

[Detailed description of the invention] It relates to lubrication devices such as compressors.

FIG. 1 shows a part of a longitudinal section of a conventional multi-cylinder internal combustion engine. In the figure, 1 is the cylinder block of the engine, 2 is the cylinder, 3 is the cylinder 2 inner door, 4 is the piston, 5 is the piston pin, 6 is the connecting rod, 61 is the small end bearing of the connecting rod, that is, the piston pin bearing, 62 is the large end bearing, that is, the crank pin bearing, 7 is the crankshaft, 7l is the crank main bearing,
72 is a fuel supply passage.

Generally speaking, 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 an internal combustion engine. It is supplied to the crank pin bearing 62 and the piston pin bearing 6l, generates oil film pressure by rotation and rocking of the shaft, and receives pressure inside the cylinder 2 applied via the piston 4.

Figure 5 shows these situations. Figure (a) shows the change in cylinder gas pressure depending on the crank angle θ. Generally, the pressure of the piston 4 is highest near the top dead center (TDC). Push down piston 4. As a result, there is an oil film pressure on each bearing. is generated as shown in Figure (b), and in response to this force, the work caused by the reciprocating motion of the piston is smoothly converted into rotational motion of the crank. At this time, the oil film thickness h of the bearing portion gradually becomes thinner as the piston passes the top dead center (TDC), as shown by the solid line in Figure (c), and after reaching the minimum oil film thickness inside the cylinder. When the pressure drops, it recovers again.

As mentioned above, in an internal combustion engine, the reciprocating motion of the piston is converted into rotational motion by the crank mechanism, but as shown in Figure 5, when the bearing load is high, the crank angle is 30° to 60°.
It is about °. On the other hand, conventional bearings do not have sufficient load capacity because they rely solely on the formation of an oil film due to the wedge effect caused by the rotation of the bearing. The reliability of the bearing is maintained. As a result, the bearings of the engine become larger, which increases the overall size and weight of the engine.
There is a drawback that the cost is high, the bearing area is large, and the circumferential speed of the bearing section is also high, so that the friction loss of the bearing section becomes large.

Especially in highly supercharged internal combustion engines, the pressure inside the cylinder is large.
As the engine speed increases, it becomes necessary to thicken the bearings, and as a result, it is not possible to sufficiently reduce the weight of the engine, and the loss of horsepower in the bearings also increases, making it impossible to fully improve the efficiency of the engine due to high supercharging. There are drawbacks.

The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a lightweight controller for engines.
The object of the present invention is to provide a lubrication device for a reciprocating engine that significantly reduces friction and mechanical loss.

The reciprocating engine lubrication device of the present invention focuses on the periodicity of engine operation, and applies high-pressure oil from the outside during periods of high bearing load so that the bearing load capacity maintains a sufficient oil film thickness. It is configured to achieve the above objective by periodically supplying it from a little earlier to when the load is high.

An embodiment of the present invention will be described below based on the accompanying drawings.

Here, the same or equivalent components as those of the conventional device will be described using the same reference numerals.

Figure 2, like Figure 1, shows a part of the longitudinal section of the internal combustion engine, where l is the cylinder block, 2 is the cylinder, 3 is the cylinder head, 4 is the piston, 5 is the piston pin, and 6 is the connecting rod. , 61 is a piston pin bearing part, 62 is a crank pin bearing part, 7 is a crankshaft, 73 is a crank main bearing part,
Reference numeral 74 indicates an oil supply passage, 8 indicates a displacement type pump 0 that is driven in synchronization with the crankshaft and delivers high-pressure oil for a predetermined period of the crank angle, and 81 connects this pump to the main bearing portion 73. It's a fuel pipe.

In the figure, the oil supply passage 74 has the main bearing 7.3a = ← In Figure 2, the high-pressure oil supply pump 8 has a number of plant pumps corresponding to the number of cylinders of the engine, and each one corresponds to cylinder 2 of the engine. It is connected to the oil supply passage 74 of the main bearing 73 via the oil supply pipe 81 . Furthermore, the crankshaft 7 and the pump drive shaft are connected so that the delivery timing of the oil supply pump 8 corresponds to the vicinity of the compression top dead center of the corresponding cylinder.

Therefore, when the piston 4 rises to the vicinity of the top dead center, the corresponding silant of the high-pressure oil supply pump 8 is activated, and high-pressure lubricating oil flows through the oil supply pipe 81 to the main bearing 73a.

73b, passes through the oil supply passage 74, passes through the oil passage in the crank pin bearing part 62 and the connecting rod 6, and reaches the piston pin bearing part 62. As a result, high-pressure oil enters the bearing, lifting the shaft and thickening the oil film. After that, the oil supply is stopped, but since a thick oil film has already been formed and the pressure inside the cylinder 2 has decreased, a sufficiently thick oil film is maintained. This is illustrated in FIG. 5(C). this(
c) The one shown by the broken line in the figure is according to the present invention, and by applying high-pressure pongee oil around the top dead center as shown in the broken line as shown in Fig. 5(b), the result shown in Fig. 5(c) is As shown in the figure, 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 and squeezing effect caused by the rotation of the shaft, making the engine smaller and lighter and significantly reducing mechanical losses. can be measured.

FIG. 3 shows a second embodiment of the present invention, in which the structure of the engine body is the same as that of the first embodiment shown in FIG. 2, but the high pressure oil supply system is changed. Figure 3 shows the main bearing portion 73a shown in Figure 2 in detail.
4 is supplied from the high pressure oil pressure accumulator lO through the high pressure conduit 101 and the distributor 9 to the oil supply pipe 9 corresponding to each cylinder.
It is a structure that goes through 1.

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 similarly to Embodiment 1 shown in FIG. Opening characteristics are provided to supply high pressure oil to the intended bearing system.

In this system, a predetermined amount of high-pressure oil is stored by a high-pressure pump (not shown) provided separately from the pressure accumulator 10.
It is supplied into the shaft of the distributor 9 through the bearing system of the target cylinder by rotation of the distribution shaft, and its operation and effect are the same as in the first embodiment.

Figure 4 shows the third embodiment of the present invention, and the structure of the engine body is the same as the first embodiment.
This is similar to the embodiment, but with a different high pressure oil supply system. FIG. 4 shows a system having a distributor 11 with an electrically driven valve, which distributes high-pressure oil from an accumulator 12 through a high-pressure conduit 121, which is supplied from a separate high-pressure pump (not shown). 11 and at predetermined times by an electrically driven valve actuated in response to the trough 7 ring of the engine.

High pressure oil passes through the oil supply pipe 111 for a predetermined period of time to the main bearing 73a'=! shown in FIG. j=hi; supplied to the oil supply path 74;

In this example, high-pressure oil from the pressure accumulator 12 is applied to the main bearing at a predetermined time and for a predetermined period by a solenoid valve that opens and closes using an electric current controlled by a separate electrical control system (not shown). 73a=# key i By supplying oil to the oil supply system 74, the same effect as that described for the first embodiment with reference to FIG. 5 is performed, and the effect is the same as that of the first embodiment.

As mentioned above, the oil supply device for a reciprocating engine according to the present invention includes:
A lubrication device that works with the crankshaft and periodically supplies high-pressure oil is installed in the independent lubrication passage connecting the crankshaft main bearing, crankshaft bearing, and piston pin bearing for each of the seven rings, making the engine lighter and more compact. It is possible to achieve a significant reduction in mechanical loss, and since refueling is only performed for a short time, the number of oil gauges can be reduced, and the capacity of auxiliary equipment can be reduced.

[Brief explanation of drawings]

Figure 1 is a partial longitudinal sectional view of a conventional multi-cylinder reciprocating internal combustion engine.
Fig. 2 is a schematic diagram of a first embodiment of a reciprocating engine lubrication device according to the present invention, Fig. 3 is a configuration diagram of a high-pressure oil supply system portion of the second embodiment, and Fig. 4 is a diagram of a third embodiment of the same. Figure 5 shows the configuration of the high-pressure oil supply system, with respect to the crank angle θ, (a) shows the cylinder internal pressure p, (b) shows the bearing hydraulic pressure pb,
(c) is the oil film thickness. FIG. 2 ・Cylinder, 4...Piston, 8, (9,10)
. (11, 12) - Oil supply device, 61 Piston pin bearing, 62 Crank bottle bearing, 73a, 73b... Crankshaft main bearing, 74... Oil supply passage. Figure 1 Figure 2 Figure 3 0 12

Claims (1)

[Claims] In reciprocating engines such as internal combustion engines and compressors that have reciprocating pistons, each cylinder has an independent oil supply passage that connects the crankshaft main bearing, crank pin bearing, and piston pin bearing, and an oil supply passage that connects the crankshaft to the piston pin bearing. A lubricating device for a reciprocating engine, comprising a lubricating device that periodically supplies high-pressure oil.