JPH0420994Y2 - - 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 side of the abutment 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 having a flat cross section is inserted through a through hole provided in the intermediate piece and is disposed astride the abutment,
Moreover, the guide rod is locked to the spacer expander at a twisted portion formed by twisting the guide rod.

[Effect]

The guide rod is attached to the spacer expander while straddling the abutment, and the twisted portion formed on the guide rod is locked to the spacer expander, thereby preventing movement of the through hole in the circumferential direction. Ru. When assembling the spacer expander into the piston ring groove, when the abutment of the spacer expander is expanded, the through hole in the middle piece of the spacer expander slides along the guide rod, and the abutment is always guided by the guide rod. It spreads. 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, and the abutment is always guided by the guide rod, as described above. , the spacer expander returns to its original state with the abutments closed without the abutments overlapping.

〔Example〕

Fig. 1 is a perspective view showing the vicinity of the abutment of the spacer expander with the guide rod attached, and shows the abutment closed; Fig. 2 is a perspective view showing the vicinity of the end of the guide rod in Fig. 1; The figure 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 an elliptical cross section and approximately the same curvature as the spacer expander 1. Most of the guide rods 7 are made of steel wire that is elastic at high temperatures; As long as it has, it may be made of resin or the like, and its material does not matter. Further, the cross-sectional shape is not limited to an elliptical shape, but may be a flat shape, and it is preferable that the cross-sectional shape is curved with a curvature close to that of the spacer expander 1.

When installing the spacer expander 1 in the ring groove 10 of the piston 9 as shown in FIG.
Attach it to That is, spacer expander 1
A guide rod 7 is inserted into a through hole 6 provided in an intermediate piece 4 of
, and attach it to the spacer expander 1 so that it straddles the abutment 5. Then, by twisting the end of the guide rod 7 180 degrees, the end is turned into the twisted part 8.
form. This twisted portion 8 is larger than the axial width of the through hole 6 provided in the intermediate piece 4, and the guide rod 7 is locked to the spacer expander 1 to extend the through hole 6 in the circumferential direction. Prevented from moving. In addition, the twist angle of the above-mentioned twist part 8 is
A temperature of 30 degrees or more is suitable. Furthermore, it goes without saying that the position of the twisted portion 8 is not limited to the above position.

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. 3, 11 is a side rail arranged on the upper and lower surfaces of the spacer expander 1;
is a cylinder.

FIG. 2 shows an example in which the end of the guide rod 7 is placed between the inner bottom pieces 3, while FIG. 4 shows an example in which the end of the guide rod 7 is placed between the inner bottom pieces 3 This figure shows a case in which a twisted portion 8 similar to that shown in FIG. 2 is formed at the end.

[Effect of idea]

As explained above, according to the present invention, in a circumferential wave type spacer expander, a guide rod having a flat cross section is inserted through a through hole provided in an intermediate piece and is disposed astride the abutment. , and by locking the guide rod to the spacer expander 1 at the twisted portion formed by twisting the guide rod, when assembling the spacer expander 1 into the piston ring groove, one of the abutments of the spacer expander can be attached to the other. It is possible to reliably prevent the abutments from overlapping by overcoming this.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view showing the vicinity of the abutment of a spacer expander equipped with a guide rod, with the abutment closed, and FIG. 2 shows a state where the abutment is closed. Figure 3 is a perspective view showing the vicinity of the end; Figure 3 is a sectional view of the ring groove portion of the piston incorporating the spacer expander and side rail;
This figure is a perspective view showing the vicinity of the end of the guide rod similar to that in FIG. 2. 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 twisted portion, 9 is a piston, and 10 is a ring groove.

Claims (1)

[Claims for Utility Model Registration] (1) 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 a spacer expander, a guide rod with a flat cross section is inserted through a through hole provided in the intermediate piece and is disposed astride the abutment, and the guide rod is twisted at a twisted portion formed by twisting the guide rod. A spacer expander abutment overlap prevention structure, characterized in that the spacer expander is locked to the spacer expander. (2) The spacer expander abutment overlap prevention structure according to claim 1, wherein the guide rod has an elliptical cross section. (3) The spacer expander abutment overlap prevention structure according to claim 1, wherein the twist angle of the twist portion is 30 degrees or more.