JPS6114600Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structure for attaching a ring carrier to a ring groove of a piston.

Generally, in direct injection diesel engines,
The heat load on the top of the piston is greater than in other internal combustion engines, so it is necessary to cool the piston sufficiently, especially in engines with a large output per cylinder or supercharged engines. It is necessary.

Therefore, conventionally, for high-output engines, an annular oil groove 6 is provided on the outside of the combustion chamber 5 of the piston as shown in FIG. The piston heat load is reduced by injecting
On the other hand, a ring carrier (also called a ring trager) 3 with a U-shaped cross section is cast into the top ring groove 2 of the piston 1 to prevent wear and deformation of the groove 2 caused by the top ring 4. 6, the inner thickness t of the portion 7 between the oil groove 6 and the back surface of the ring carrier 3 becomes smaller.
A problem arises in that the mechanical strength of the piston is reduced.

Therefore, in order to solve this problem, the wall thickness t of the portion 7 can be increased by using a split type ring carrier consisting of only an upper piece and a lower piece instead of the conventional ring carrier 3 having a U-shaped cross section. Although this is desirable from the standpoint of piston strength, such a ring carrier with a top and bottom split type has the disadvantage that it easily falls out of the ring groove.

The object of the present invention is to provide a ring carrier mounting structure that eliminates the above-mentioned drawbacks.

Hereinafter, embodiments of the present invention will be described with reference to FIG. 2 and subsequent figures.

2 shows a first embodiment of the present invention. The ring carrier 8 shown in the figure is a split type ring carrier in which an upper piece 9 and a lower piece 10 are formed by casting, and therefore the thickness t of the portion 7 between the groove bottom surface 12 of the ring groove 11 and the oil groove 6 can be made large. The upper piece 9 has an upper surface 13 that slopes obliquely upward from the outer periphery to the inner periphery, and has an inclined surface 14 on its inner periphery that is even steeper than the upper surface 13.
On the piston 3, fitting pieces 15 inclined with respect to the vertical line, i.e., the axis of the piston, are provided at predetermined intervals along the circumferential direction (along the direction perpendicular to the paper in FIG. 2) as shown in FIG. 3. These fitting pieces 15
The side shape of the fitting piece 15 (i.e., the shape when viewed from the direction of the arrow A in Fig. 2) is dovetailed as shown in Fig. 3. The fitting piece 15 is dovetailed in order to prevent the ring carrier 8 from falling off.
The dovetail-shaped cross section is not limited to the cross section shown in FIG. 3, but may be the cross section shown in FIG.

On the other hand, the upper surface 1 of the ring groove 11 of the piston
6 and bottom upper part 12' are also formed as inclined surfaces corresponding to the upper surface 13 and inclined surface 14 of the upper piece 9, respectively, and fitting grooves 17 for receiving fitting pieces 15 are provided at predetermined intervals in the circumferential direction. There is.

On the other hand, the lower piece 10 is symmetrical to the upper piece 9, with a lower surface 1 that slopes downward from the outer peripheral edge to the inner peripheral edge.
8. It has a fitting piece 19 projecting from the lower surface 18, and an inclined surface 20 formed diagonally downward on the inner peripheral edge. In addition, a lower piece 10 is provided in the ring groove 11.
A slanted lower surface 21 corresponding to the lower surface 18 and a lower bottom surface 12'' formed corresponding to the sloping surface 20 are provided, and fitting grooves 22 are provided at predetermined intervals along the circumferential direction. 19, like the fitting piece 15 of the upper piece 9, projects from the lower surface 18 of the lower piece 10, and its side surface shape is dovetail like the fitting piece 15 shown in FIG.

According to the above mounting structure, the fitting piece 1
Since the cross sections of the ring carriers 5 and 19 are dovetail shaped, the ring carrier 8 is prevented from falling. Furthermore, if the structure is provided with the inclined surfaces 14 and 20, the effect of preventing falling off becomes even greater.

As described above, according to the present invention, the split ring carrier can be firmly attached to the piston without reducing the mechanical strength of the piston, and as a result,
Piston cooling performance can be improved.

[Brief explanation of the drawing]

Fig. 1 is a partial longitudinal sectional view of a piston with a conventional ring carrier attached, Fig. 2 is a longitudinal sectional view showing a piston and a split ring carrier attached to the piston using the mounting structure of the present invention, and Fig. 3 is a longitudinal sectional view of a piston with a split ring carrier attached to the piston using the mounting structure of the present invention. FIG. 3 is a view taken along the - line in FIG. 2; 1: Piston, 2, 11: Ring groove, 6: Oil groove, 3, 8: Ring carrier, 9: Upper piece, 1
0: Lower piece, 15: Fitting piece, 19: Fitting piece, 1
7: Fitting groove, 22: Fitting groove.

Claims (1)

[Claims for Utility Model Registration] In a ring carrier mounting structure for mounting a split ring carrier consisting only of an upper piece and a lower piece in a ring groove of a piston, a ring carrier is provided with a circumferential surface on the upper and lower surfaces of the ring groove. fitting grooves are formed at predetermined intervals in the circumferential direction, and fitting pieces are protruded from each of the upper piece and the lower piece at predetermined intervals in the circumferential direction; A mounting structure for a ring carrier, wherein each of the fitting piece and the fitting groove has a dovetail shape.