JPH059472Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cylinder liner used in internal combustion engines and the like.

[Conventional technology]

FIG. 6 shows a piston portion of an internal combustion engine (hereinafter referred to as engine), and FIG. 7 shows an example of lubricating oil consumption (hereinafter referred to as oil consumption) with respect to engine rotational speed.

In Fig. 6, 1 is a cylinder liner, 2 is a piston, 3 is a top ring, 4 is a piston pin,
5 is connecting rod, a is lubricating oil (oil)
shows. Further, 6 is a piston top land of the piston 2, 7 is a ring land, and 8 is a piston skirt.

In an internal combustion engine, a top ring 3 is installed at the top of the piston 2 to seal the high temperature gas in the combustion chamber.
Oil a is used to smooth the friction between the top ring 3 and the cylinder liner 1. This oil a is supplied through an oil jet provided in an oil pan (not shown), a crankshaft, or an opening from a connecting rod 5.

[Problem that the invention attempts to solve]

In general, the consumption amount of oil a increases greatly depending on the engine speed, as shown in FIG. The reason why the oil consumption increases almost in proportion to the square of the rotational speed is that the oil that accumulates in the area surrounded by the top spring 3, the top ring 6 of the piston, and the cylinder liner 1 is splashed by inertia and enters the combustion chamber. However, conventional engines do not take any measures to prevent droplets from entering the air and disappearing through evaporation or combustion.

The present invention addresses the above-mentioned problems, and aims to reduce the oil consumption rate of the engine by suppressing the large increase in oil consumption accompanying the increase in engine speed.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a ring groove on the inner periphery of the cylinder liner, and installs an oil draining ring having an oil draining recess on the lower surface in the ring groove. By arranging the concave portion of the ring near the position of the top surface of the piston when the piston is at the top dead center, it is possible to reduce oil flow as the engine speed increases, that is, oil consumption. It is characterized by having been configured.

[Effect]

By having the above structure, it is possible to prevent the oil accumulated in the area surrounded by the top ring and top land and the cylinder liner from becoming droplets due to inertia force and rising into the combustion chamber.

〔Example〕

1 to 5 of the present invention.
To explain an embodiment, FIG. 1 shows an example in which a cylinder liner according to the present invention is used in an engine.

1 is a cylinder liner according to the present invention, 10 is a ring groove provided in the cylinder liner 1, 11 is a piston ring inserted into the ring groove 10 and has tension on the outside, and 12 is provided on the lower surface of the piston ring 11. It is a dent. The groove 10 of the cylinder liner 1 is provided so that the recess 12 is located close to the upper end corner 6a of the top land 6 when the piston 2 reaches the top dead center.

Incidentally, as shown in FIG. 2, the bush 14 may be fitted into the inner periphery of the cylinder liner 1 after the piston ring 11 or the ring 13 without a gap is inserted into the cylinder liner 1.

In the conventional engine, the oil present in the portion 15 surrounded by the piston ring 3, the piston toppland 6, and the cylinder liner 1 is destroyed by inertial force at the top of the engine, as shown in FIG. It turns into droplets and disappears as shown by the arrow. On the other hand, in the present invention, a piston ring 11 stretched outwardly and a normal ring 13 without a joint are provided on the inner periphery of the cylinder liner 1, so that the ring 11 (or 13) prevents the oil from rising. This can prevent oil from entering the combustion chamber in the form of droplets at top dead center.

[Effect of idea]

Since the present invention is configured as described above, it has the following effects.

The oil draining ring installed on the inner surface of the cylinder liner can prevent oil that accumulates in the area surrounded by the top ring and top land and the cylinder liner from turning into droplets due to inertia and rising into the combustion chamber.

In conventional engines, the drastic increase in oil consumption due to rotation was dealt with by increasing the surface pressure on each stage ring, but this tends to cause scuffing and abnormal wear. In contrast, with the cylinder liner of the present invention, as shown in Figure 5, it is possible to significantly reduce the increase in oil consumption due to an increase in rotation speed without increasing the surface pressure of the piston rings at each stage. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of essential parts showing one embodiment of the present invention;
FIG. 2 is a sectional view of a main part showing another embodiment of the present invention. Figure 3 shows the oil splash state of a conventional engine.
FIG. 4 is a cross-sectional view showing how oil splash is prevented in the cylinder liner of the invention, and FIG. 5 is a diagram showing an example of the effect of reducing oil consumption when using the cylinder liner of the invention. FIG. 6 is a cross-sectional view of the vicinity of the upper part of a cylinder liner showing a conventional example, and FIG. 7 is an oil consumption curve of a conventional engine that is exactly the same as the broken line curve in FIG. 5. 1...Cylinder liner, 2...Piston, 6...
...Totsupurando, 10...groove, 11, 13...ring.

Claims (1)

[Claims for Utility Model Registration] In an internal combustion engine that supplies lubricating oil between a piston ring and a cylinder liner, a ring groove is provided on the inner periphery of the cylinder liner, and a recess for draining oil is provided on the lower surface of the ring groove. The piston is equipped with an oil draining ring having a section, and the ring groove is provided such that the concave section of the ring is located near the position of the top surface of the piston when the piston is at the top dead center. cylinder liner.