JPH0417796Y2 - - 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 is inserted through a through hole provided in the intermediate piece and is disposed astride the abutment, and the tip of the guide rod is bent toward the inner bottom surface of the inner bottom piece, and the guide rod is inserted at the bent portion. It is characterized by being locked to the spacer expander.

[Effect]

The guide rod, which is attached to the spacer expander with the abutment straddling the guide rod, is prevented from moving in the circumferential direction through the through hole by having the bent portion at the tip thereof locked to the spacer expander. When the spacer expander is assembled into the piston ring groove and 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 of the intermediate piece of the spacer expander slides along the guide rod, as described above.
The abutment is always guided by the guide rod, and the spacer expander returns to its original state with the abutment closed without the abutment overlapping.

〔Example〕

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

When installing the spacer expander 1 in the ring groove 10 of the piston 9 as shown in FIG.
The spacer expander 1 is inserted into the through hole 6 provided in the middle piece 4 of the spacer expander 1, and is attached to the spacer expander 1 while straddling the abutment 5. Then, one tip of the guide rod 7 is bent toward the inner bottom surface 3a of the inner bottom piece 3, and this tip bent portion 8 is locked to the inner bottom piece 3 of the spacer expander 1, thereby opening the through hole 6. movement in the circumferential direction is prevented.

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.

Incidentally, a part of the through hole 6 may be made into a hole slightly larger than the cross-sectional shape of the guide rod 7, for example, a round hole.

[Effect of idea]

As explained above, according to the present invention, in the circumferential wave type spacer expander, the guide rod is inserted through the through hole provided in the intermediate piece and is disposed astride the abutment. By bending the tip toward the inner bottom surface of the inner bottom piece and locking the guide rod to the spacer expander at the bent portion,
When assembling the spacer expander into the piston ring groove, it is possible to reliably prevent one of the abutments of the spacer expander from climbing over the other and overlapping the abutments. It is easy to bend the tip of the guide rod toward the inner bottom surface of the inner bottom piece, and the through hole at the bent point does not need to be of any special shape or size. hole-like)
can be used for both purposes, increasing productivity.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG.
The drawing is an enlarged front view showing a part of Fig. 1, and Fig. 3 is a sectional view of a ring groove portion of the piston incorporating a spacer expander and a 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 bent portion, 9 is a piston, and 10 is a ring groove.

Claims (1)

[Scope of utility model registration request] In a circumferential wave type spacer expander 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, the guide rod is connected to the intermediate piece. The guide rod is inserted through a through-hole provided in the piece, and is disposed astride the abutment, and the tip of the guide rod is bent toward the inner bottom surface of the inner bottom piece, and the guide rod is engaged with the spacer expander at the bent portion. A structure that prevents the spacer expander from overlapping at the abutment.