JPS6251741A - Internal combustion engine with liner intermediate member - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention comprises a cylinder cover and a liner provided with a mounting collar, and between the mounting collar and the cylinder cover, a piston ring area is provided. The present invention relates to an internal combustion engine in which a coolable intermediate member forming an upper cylinder wall is provided.

[Conventional technology]

An internal combustion engine of this type is known from German Patent Application No. 3,417,515. The intermediate part is also called a "flame ring" since it annularly surrounds the combustion chamber between the support collar and the cylinder cover.

This intermediate member prevents the harmful effects of combustion pressure and heat on the liner.

However, in addition to the problems to be solved due to the mechanical and thermal loading of the liner, there is the difficulty of avoiding striations on the cylinder wall. These streaks are caused in particular by the formation and accumulation of oil coke on the piston.

[Purpose of the invention]

The problem on which the invention is based is to ensure that the accumulation of coke on the piston does not exceed limits.

[Structure of the invention]

This problem is solved in that the inner diameter of the intermediate member is smaller than the inner diameter of the liner, at least in part of the cylinder wall section of the intermediate member.

〔Effect of the invention〕

If the intermediate impression material is formed in this way, during the stroke movement of the piston, the coke that tends to accumulate radially outward in the running gap is scraped off by the piston. The piston is "corrected" during each stroke.

In the embodiment of the present invention, this dimensional correction effect is achieved by the fact that the inner diameter of the intermediate member decreases continuously in the direction of the longitudinal axis of the cylinder from the liner mounting collar to the cylinder cover, and/or that the intermediate member forming the cylinder wall is This is further improved by hardening the surface portion of the member.

In order to enhance the scraping effect and to ensure that the oil coke is scraped off and conveyed upward toward the combustion chamber, the cylinder wall portion formed by the intermediate member is coated with a file with the scraping surface facing toward the cylinder cover. structure or m
It may also include a tooth structure.

〔Example〕

Hereinafter, the present invention will be explained in detail based on embodiments schematically illustrated in the figures.

FIG. 1 shows a conventional cylinder structure for an internal combustion engine. This cylinder structure comprises an engine stand 1, a liner 2 with a mounting collar 3, and a piston 4 carrying a piston ring 5.

In contrast, FIG. 2 shows a cylinder structure according to the invention. The cylinder structure comprises an engine stand 6, a liner or piston running bush 7 with a mounting collar 8, and a piston 9 with a piston ring IO. Above the area of the piston ring IO, an intermediate part 11 with a cooling water chamber 12 is arranged on the support 8 as follows. That is, the intermediate member is provided so as to annularly surround the upper portion of the piston 9 and whose cylinder wall portion 13 forms part of the combustion chamber wall.

FIG. 3 shows a cylinder structure with an intermediate member 14 according to another embodiment of the invention. In the case of this cylinder structure, the engine stand is indicated by 15, the liner is indicated by 16, the mounting collar is indicated by [7], the piston is indicated by 18, and the cylinder cover or cylinder head is indicated by 25.

FIG. 4 shows a further embodiment of an intermediate part I9 for an internal combustion engine cylinder according to the invention.

In the case of conventional cylinder structures, the liner and its mounting collar tend to warp under the effects of the high temperatures and pressures generated during fuel combustion, as shown exaggerated in FIG. The upper portions of the liner and the mounting collar widen, and the gap between the piston 4 and the mounting collar 3 becomes larger.

When the coke is deposited on the piston edge 20, the hard coke inevitably reaches the enlarged upper running gap above the piston ring 5, as shown by the arrow 2I. oil coke 1
Overworking initially results in the formation of striations or burrs in the upper portion of the liner 2. This is indicated by arrow 22.

The formation of such streaks can lead to major engine failure and even shutdown.

In order to prevent oil coke deposits 23 from exceeding limits and to avoid shutdowns, the invention provides that the inner diameter d of the intermediate member 11, 14, 19 is equal to or smaller than at least one of its cylinder wall portions, e.g. The inside diameter of the liner, for example 7 or 16, is smaller than that of the liner.

A part constitutes the combustion chamber. Therefore, the intermediate part, which is called a "refractory ring" or "flame ring," has a smaller diameter d than the liner and therefore exerts a dimensional correction effect on the respective piston. Therefore, oil coke deposits exceeding the diameter d are scraped off again during the piston stroke movement. The diameter reduction by the intermediate part then reaches values of the order of 1 per mil.

In order to improve the abrasive action, other embodiments of the invention include:
As shown by the angle α in FIG. 3, the inner diameter d of the intermediate member 14 is
It gradually becomes smaller and smaller toward 5.

Furthermore, as indicated by the cross in FIGS. 2 and 3, the surface portion 1 of the intermediate member 11 or 14 forming the cylinder wall
It is advantageous to cure 3 or 24.

The scraping of oil coke and its transport into the combustion chamber are improved by providing the surface portion of the intermediate member 9 forming the cylinder wall with a rasp or sawtooth body, as shown in Figure 4. be done.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional cylinder structure, FIG. 2 is a sectional view of a cylinder structure according to the present invention, FIG. 3 is a sectional view of another embodiment of the cylinder structure according to the present invention, and FIG. The figure is a sectional view of a wall portion of another embodiment of the present invention. 7.16... liner, 8,17... mounting collar,
10...Piston ring, 11°14.19
... intermediate member, 25 ... cylinder head, d
...Inner diameter of intermediate member, D...Inner diameter of liner FIG, 1

Claims (1)

[Claims] 1. A coolable intermediate comprising a cylinder cover and a liner with a mounting collar, and forming a cylinder wall above the piston ring area between the mounting collar and the cylinder cover. In an internal combustion engine in which a member is provided, an intermediate member (
The inner diameter (d) of the intermediate member in at least a part of the cylinder wall portion of the liner (7; 16)
) is smaller than the inner diameter (D) of the engine. 2. Claims characterized in that the inner diameter of the intermediate member (14) decreases continuously in the cylinder longitudinal axis direction from the mounting collar (17) of the liner (16) to the cylinder cover (25). The internal combustion engine according to paragraph 1. 3. The internal combustion engine according to claim 1 or 2, characterized in that the surface portion (13; 24) of the intermediate member (11; 14) forming the cylinder wall is hardened. 4. Any one of claims 1 to 3, characterized in that the surface portion of the intermediate member (19) forming the cylinder wall is formed in the form of a dimension correction tool having a cutting surface. An internal combustion engine as described in one of the following.