JPS6244169Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a connecting rod for an internal combustion engine, and in particular, the connecting rod is made of composite materials such as FRP (fiber reinforced plastic), FRM (fiber reinforced metal), or Al alloy. When using light alloy materials to reduce weight, the stress level is high at the oil outlet at the shoulder at the large end of the connecting rod, and the strength at the small end of the connecting rod decreases due to insufficient cooling, but these can be alleviated. It's about structure.

Conventionally, connecting rods are mainly made of carbon steel forgings (for example, S55), and in order to lubricate the sliding parts between the piston and the cylinder bore, oil is applied to the large end shoulder 1' as shown in Figure 1. Although an air outlet 2' is provided, when using alternative materials (light alloys such as Al alloy, composite materials such as FRP and FRM) to reduce the weight of the connecting rod, the small end of the connecting rod may be There is a problem that the connecting rod may be damaged due to a decrease in strength due to insufficient cooling of the connecting rod, and stress concentration due to a notch such as an oil outlet in the shoulder of the large end. In particular, the strength of composite materials such as FRP and FRM, and light alloy materials such as Al alloys suddenly decreases at approximately 150℃ to 200℃, and the operating temperature environment of connecting rods is 150℃.
℃ to 180℃, it will be difficult to apply lightweight materials unless the problems of temperature-induced strength reduction and stress concentration at the notch are solved.

The present invention solves the problems of strength reduction due to temperature and stress concentration due to notches, and allows connecting rods to be manufactured using composite materials such as FRP and FRM, or light alloy materials such as Al alloy. The aim is to significantly reduce the weight of the reciprocating parts compared to conventional carbon steel ones, and to greatly contribute to improving engine output and fuel efficiency by reducing the weight of the reciprocating parts.

In order to achieve this purpose, the connecting rod for an internal combustion engine of the present invention solves the problem of cooling by providing an oil outlet connected to the oil passage from the crankshaft at the large end. The problem of stress concentration at the oil outlet at the big end was solved by spraying the oil from the piston to the small end of the connecting rod in addition to the lubricating part of the piston. This problem can be solved by providing the large end outer ring at a relatively low stress level, which makes it possible to construct the connecting rod from composite materials such as FRP and FRM, or light alloy materials such as Al alloy. ing.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

2 and 3 show a connecting rod according to an embodiment of the present invention. In the figure, a connecting rod 1 is made of a composite material such as FRP or FRM or a light alloy material such as an Al alloy. The big end 2 of the connecting rod 1 has a bearing hole extending from the shoulder 3 (that is, the central part along the central axis 5 of the big end bearing hole 4 and extending smoothly from the column part 6). Oil outlet ports 8 and 9 are provided in the large end outer ring portion 7 located apart in the direction along the central axis 5 of 4.
is provided. Of these, the oil outlet 8 is directed toward the sliding portion between the piston and the cylinder bore, and is therefore directed diagonally upward. Also, the oil outlet 9 is directed toward the small end 10 of the connecting rod 1, and therefore the small end 1
The small end bearing hole 11 is opened almost directly upward at a position directly below the end 13 in the direction of the axis 12.

The bearing 14 is made of a metal bearing, and has sufficient strength and lubrication performance as in the past, and the oil passage connecting the oil outlet 8 and the oil outlet 9 is as shown in FIGS. 4 and 5. It consists of an oil groove 15 formed in this bearing 14. The bearing 14 is also provided with a hole 16 that communicates between the inner and outer circumferences of the bearing 14, and the oil groove 15 is connected to this hole 16. The hole 16 is continuously connected to an oil supply passage provided in the crankshaft as the crankshaft rotates, and when the oil supply passage of the crankshaft and the hole 16 are aligned, the oil supplied from the crankshaft is connected. The oil is blown out from oil outlets 8 and 9.

FIG. 6 shows a bearing 14 according to another embodiment of the present invention.
This is what is shown. The oil blow-off ports 8, 9 may be provided at any position as long as they are provided in the portion corresponding to the large end outer ring portion 7, that is, the shaded portion in FIG. 6, and any number of oil blow-off ports may be provided. The embodiment shown in FIG. 6 shows a case where three oil grooves 15 are formed in the bearing 14 to guide oil to the three oil outlets 9 when three oil outlets 9 are provided.

In the connecting rod 1 of the present invention configured as described above, oil is supplied to the sliding portion between the piston and the cylinder bore through the oil outlet 8, and the small end of the connecting rod 1 is supplied with oil through the oil outlet 8. 1
0 is also sprayed with oil, and the small end 10, which is particularly stressed, is cooled to approximately the same temperature as the oil, that is, 90°C to 120°C. Therefore,
Since the temperature can be maintained below 150°C, which is the point at which material strength begins to decline, strength decline due to temperature is prevented.

Further, the stress level of the large end outer ring portion 7 is lower than that of the shoulder portion 3, and even if the oil outlets 8, 9 are drilled in this portion, the concentrated stress is small and will not lead to fatigue failure. Further, since the oil groove 15 is provided on the bearing metal 14 side, problems regarding the strength and damage of the connecting rod 1 do not occur.

As described above, when using the connecting rod for an internal combustion engine of the present invention, it is possible to sufficiently cool the connecting rod and there is no problem of fatigue damage caused by the oil outlet.
It is now possible to manufacture connecting rods using composite materials such as FRM or light alloy materials such as Al alloy, making it possible to reduce the weight of the reciprocating parts of reciprocating internal combustion engines. The ultimate effect is that engine output can be improved and fuel efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view of a conventional connecting rod, FIG. 2 is a front view of a connecting rod for an internal combustion engine according to the present invention, and FIG. 3 is a front view of the connecting rod of FIG. 2. 4 is a plan view of the large end bearing of the connecting rod shown in FIG. 2, FIG. 5 is a sectional view of the bearing shown in FIG. FIG. 3 is a plan view of the bearing. 1...Connecting rod, 2...Big end,
3...Shoulder part, 7...Big end outer ring part, 8, 9...Oil outlet, 10...Small end part, 14...Bearing, 15...
...Oil ditch.

Claims (1)

[Scope of utility model registration request] A big-end outer ring made of a composite material such as fiber-reinforced plastic, fiber-reinforced metal, or a light alloy material such as aluminum alloy, and located away from the big-end shoulder 3 in the direction along the center axis 5 of the big-end bearing hole. Part 7
A first oil outlet 8 blows oil toward the cylinder bore surface and a second oil outlet 8 blows oil toward the small end 10.
The first oil outlet 8 and the second oil outlet 9 are connected to each other by an oil groove 15 formed in a bearing 14 fitted to the large end 2. A connecting rod for an internal combustion engine, characterized in that the connecting rod is connected to the internal combustion engine.