JPH0529587Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a spacer expander for a combination oil ring used in an internal combustion engine.

[Conventional technology]

A combination oil ring usually has one side rail arranged on the upper and lower surfaces of one spacer expander, and the side rails are brought into sliding contact with the inner wall of the cylinder by the spacer expander to scrape up and scrape down lubricating oil. This is to ensure that an appropriate oil film is always formed on the cylinder inner wall to minimize wear on the piston ring and cylinder.

There are several types of spacer expanders, but one that is already known is that the outer top piece and the inner bottom piece are spaced apart in the radial direction and arranged alternately in the circumferential direction, and that there is an intermediate portion between them. There is a circumferential corrugated spacer expander connected in pieces.

[Problem that the invention attempts to solve]

Therefore, when trying to expand the abutment of the spacer expander and insert it into the ring groove of the piston, abutting the abutment of the spacer expander within the ring groove, and then assembling the side rails, one of the abutments of the spacer expander There may be cases where one crosses over the other and the abutments overlap.

When assembled to the piston in such a state, tension cannot be applied to the side rail and the spacer expander does not function.

The present invention aims to prevent such problems and improve the spacer expander so that it can be properly assembled to the piston.

[Means for solving problems]

The structure of the present invention that achieves the above-mentioned problems is a circumferentially corrugated structure in which outer top pieces and inner bottom pieces are arranged radially apart and alternately in the circumferential direction, and are connected by an intermediate piece. In the spacer expander,
A guide rod whose tip is folded back to form a folded elastic piece at the tip is inserted through a through hole provided in the intermediate piece and placed astride the abutment, and the tip of the guide rod is provided with the elastic piece. The intermediate piece is fitted into the through hole of the intermediate piece and fixed by its elastic force.

[Effect]

The guide rod, which is attached to the spacer expander while straddling the abutment, is rotated in a circular shape by having its tip portion equipped with a folded elastic piece fixed with elastic force to the through hole of the intermediate piece of the spacer expander. Movement in the circumferential direction is prevented. Then, when assembling the spacer expander into the piston ring groove,
When the abutment of the spacer expander is expanded, the through hole in the intermediate piece of the spacer expander slides along the guide rod, and the abutment is always guided by the guide rod and expanded. After the piston ring is inserted into the groove, when the abutment of the spacer expander is closed, the through hole in the middle piece of the spacer expander slides along the guide rod, as described above, and the abutment is always guided by the guide rod. , the spacer expander returns to its original state with the abutments closed without the abutments overlapping.

〔Example〕

Figure 1 is a perspective view showing the vicinity of the abutment of the spacer expander with the guide rod attached, with the abutment closed, Figure 2 is an enlarged front view of a portion of Figure 1, and Figure 3 is the guide rod. FIG. 4 is a sectional view of a ring groove portion of a piston incorporating a spacer expander and a side rail.

A spacer expander 1 includes a plurality of outer top pieces 2 and inner bottom pieces 3 extending in the circumferential direction, which are spaced apart from each other in the radial direction and arranged alternately in the circumferential direction, and an intermediate piece 4 extending in the radial direction between them. It consists of circumferentially corrugated strips connected by . Each intermediate piece 4 is provided with an elongated through hole 6 that serves as an oil return hole.

The guide rod 7 is a curved round rod with a circular cross section and approximately the same curvature as the spacer expander 1;
Preferably it is made of steel wire. Note that the cross-sectional shape is not limited to circular, but may be rectangular, for example, and it is preferable that the cross-sectional shape be curved with a curvature close to that of the spacer expander 1. A folded elastic piece 8 is formed at one end of the guide rod 7. That is, one end of the guide rod 7 extends outward on the curvature forming surface.
It can be bent to an angular position slightly greater than 90°,
About half of this bent portion is further bent toward the guide rod 7 until the tip is located near the guide rod 7. In this way, one end of the guide rod 7 has a substantially triangular shape, and the bent portion constitutes the folded elastic piece 8. In addition, the folded elastic piece 8
The tip of the guide rod 7 may be brought into contact with the guide rod 7. Also,
In the above example, it is folded outward, but it may be folded inward. Further, the folded shape is not limited to the above-mentioned triangular shape, but may be any shape that constitutes a folded elastic piece.

When installing the spacer expander 1 in the ring groove 10 of the piston 9 as shown in FIG.
It is inserted through the through hole 6 provided in the intermediate piece 4 of the , and is arranged so as to straddle the abutment 5 . Then, the end portion of the guide rod provided with the folded elastic piece 8 is inserted into the through hole 6.
Insert it into the section. Then, the end portion is inserted into the through hole 6 part in a slightly compressed state, and is fixed to the through hole 6 part by the elastic force of the folded elastic piece 8, thereby preventing movement of the through hole 6 in the circumferential direction. be done. In this way, the guide rod 7 is attached and fixed to the spacer expander 1.

Therefore, if the guide rod 7 is attached to the spacer expander 1 as described above before assembling it to the piston 9, when assembling the spacer expander 1 to the piston ring groove 10, the abutment 5 of the spacer expander 1 can be When expanded, the through hole 6 of the intermediate piece 4 of the spacer expander 1 is connected to the guide rod 7.
, and the abutment 5 is always guided by the guide rod 7 and widened. and piston ring groove 10
When the abutment 5 of the spacer expander 1 is closed after being attached to the spacer expander 1, the through hole 6 of the intermediate piece 4 of the spacer expander 1 slides along the guide rod 7, and the abutment 5 is always connected to the guide rod 7. , the spacer expander 1 returns to its original state with the abutment closed without the abutment 5 overlapping.

In addition, in FIG. 4, 11 is a side rail arranged on the upper and lower surfaces of the spacer expander 1;
is a cylinder.

[Effect of idea]

As explained above, according to the present invention, in a circumferentially corrugated spacer expander, a guide rod whose tip is folded back to form a folded elastic piece at the tip is inserted through a through hole provided in an intermediate piece. The spacer expander is disposed astride the abutment, and the tip of the guide rod having the elastic piece is fitted into the through hole of the intermediate piece and fixed by its elastic force, so that the spacer expander can fit into the piston ring groove. When assembling the spacer expander, it is possible to reliably prevent one of the abutments of the spacer expander from climbing over the other and overlapping the abutments.
In addition, by forming a folded elastic piece on the tip of the guide rod, it is easy to insert and fix it into the through hole of the intermediate piece, and the through hole does not have to have a special shape or size, and can be used for normal oil return. Since the holes (mostly long holes) can also be used, productivity is increased.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG.
The drawings are an enlarged front view showing a part of Fig. 1, Fig. 3 is a front view of the guide rod, and Fig. 4 is a sectional view of the ring groove portion of the piston incorporating the spacer expander and the side rail. 1 is a spacer expander, 2 is an outer top piece,
3 is an inner bottom piece, 4 is an intermediate piece, 5 is an abutment, 6 is a through hole, 7 is a guide rod, 8 is a folded elastic piece, 9
is the piston, and 10 is the ring groove.

Claims (1)

[Scope of utility model registration request] In a circumferentially corrugated spacer expander in which an outer top piece and an inner bottom piece are arranged radially apart and alternately in the circumferential direction and are connected by an intermediate piece, the tip is folded back to form a tip part. A guide rod having a folded elastic piece formed thereon is inserted through a through hole provided in the intermediate piece and is disposed astride the abutment, and the tip of the guide rod with the elastic piece is inserted into the intermediate piece. A spacer expander abutment overlap prevention structure characterized by being fitted into a through hole and fixed by its elastic force.