JPH04300467A - Combination oil ring - Google Patents

Abstract

PURPOSE:To promote low fuel consumption by making the width of a combination oil ring thin resulting in shortening the piston length and miniaturizing and lightening the weight of an engine. CONSTITUTION:A combination oil ring is composed of two thin width rails 7, 8 and one expander 1. The expander 1 has an abutment and is made of a ring shaped axial waved steel band plate with its outside circumferential surface in an angle shape composed of a pair of upper and lower taper surfaces 5, 6. A rails 7, 8 are ring shaped steel band plates with abutments. The upper and lower taper surfaces 5, 6 of the expander 1 press the respective inside circumferential surfaces 9 of the rails 7, 8, outside circumferential surfaces 10 of the rails 7, 8 press an inside circumferential surface 14 of a cylinder 13, the inner circumferential side end portion of an upper surface 15 of the upper rail 7 presses an upper surface 16 of a ring groove 12 and the inner circumferential side end portion of a bottom surface 17 of the lower rail 8 presses a bottom surface 18 of the ring groove 12.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to a combination oil ring for reciprocating internal combustion engines.

0002

2. Description of the Related Art A conventional steel combination oil ring consists of two side rails and one spacer expander. There are various shapes of spacers, but all of them hold the two side rails vertically apart from each other and apply a force to the side rails to tension them outward.

0003

Therefore, in a combination oil ring having a conventional structure, a spacer is interposed between the side rails, so that the practical limit for the overall ring width is about 1.5 mm.

SUMMARY OF THE INVENTION An object of the present invention is to provide a combination oil ring that allows the overall width of the ring to be reduced.

[0005]

[Means for Solving the Problems] A first configuration of the present invention is as follows:
A combination oil ring consisting of one annular thin rail with an abutment and one expander, which is installed in a piston ring groove of an internal combustion engine, the tapered surface provided on the outer periphery of the expander. is characterized in that it contacts the inner circumferential side of the rail and presses the rail against the inner circumferential surface of the cylinder and the ring groove surface.

[0006] A second configuration of the present invention is a combination oil ring that is installed in a piston ring groove of an internal combustion engine, and includes a pair of annular upper and lower thin rails with abutments and one expander. A pair of upper and lower tapered surfaces provided on the outer periphery of the expander contact the inner periphery of the rail to press the rail against the inner periphery of the cylinder and the ring groove surface.

[0007]The taper angle of the tapered surface is 5 to 25.
It is better to have a degree.

[0008]

[Operation] When there is only one rail, the tapered surface provided on the outer periphery of the expander presses the rail from the inner periphery side, presses the outer periphery of the rail against the inner periphery of the cylinder, and also presses the outer periphery of the rail against the inner periphery of the cylinder. Since the circumferential end is pressed against the upper surface of the ring groove of the piston, and the outer circumferential end of the lower surface of the rail is pressed against the lower surface of the ring groove, it is possible to ensure oil removal on the inner circumferential surface of the cylinder and sealing of the ring groove.

When there are two rails, a pair of upper and lower tapered surfaces provided on the outer periphery of the expander presses each rail from the inner periphery side, and presses the outer periphery of the upper and lower rails against the inner periphery of the cylinder. , the inner end of the upper surface of the upper rail is pressed against the upper surface of the ring groove, and the inner end of the lower surface of the lower rail is pressed against the lower surface of the ring groove, so that oil is not scraped from the inner peripheral surface of the cylinder. This ensures the sealing of the ring groove.

Furthermore, since the expander is not inserted between the upper and lower rails, the overall width of the ring can be made thinner.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a combination oil ring consisting of two thin rails and one expander. Figure 1
- In Fig. 2, the expander 1 is composed of an annular axially corrugated steel strip with an abutment, and an upper piece 2.
and the lower pieces 3 are spaced apart in the axial direction and arranged alternately in an annular shape,
The two are connected by an intermediate piece 4 extending in the axial direction. The outer peripheral surface of the expander 1 has a protruding chevron shape consisting of a pair of upper and lower tapered surfaces 5 and 6. Each taper angle θ of the tapered surfaces 5 and 6 (see Fig. 3) is 5 to 25.
Good degree. At least the outer peripheral surface of this expander 1 is
Nitriding treatment, ion plating [TiN, TiC, T
i(C,N), CrxNY, CrxCY, etc.],
A hard coating is formed by a conventional method such as chrome plating (solid plating, bolus plating), ion implantation (N, C, etc.), or thermal spraying.

[0012] The expander 1 bends a strip plate,
After forming into an annular shape, a pair of upper and lower tapered surfaces 5 and 6 are formed on the outer circumferential surface by polishing or the like.

[0013] In the above description, the corrugated shape of the expander 1 is such that the upper piece 2 and the lower piece 3 are parallel, and the intermediate piece 4 is diagonally connected between their ends. but,
It is not limited to this. For example, it can also be configured in the form of a sine wave.

The two thin rails 7 and 8 are annular steel strips with an abutment, and the inner circumferential surface 9 and the outer circumferential surface 10 are arcuate, and at least the outer circumferential surface 10 is coated with nitrided steel. Treatment, ion plating [TiN, TiC, Ti(C,N)
, Crx NY, Crx CY, etc.], chromium plating (solid plating, bolus plating), ion implantation (N
, C, etc.) or by a conventional method such as thermal spraying.

Therefore, as shown in FIG. 1, the two rails 7 and 8 are arranged one above the other in the ring groove 12 of the piston 11, and the expander 1 is arranged on the inner circumferential side of these rails. Stretch 7 and 8 outward. That is, the upper tapered surface 5 of the outer circumference of the expander 1 presses against the inner circumferential surface 9 of the upper rail 7, and presses the outer circumferential surface 10 of the rail 7 against the inner circumferential surface 14 of the cylinder 13. The inner peripheral end of the upper surface 15 is pressed against the upper surface 16 of the ring groove 12. Further, the lower tapered surface 6 of the outer circumference of the expander 1 presses against the inner circumferential surface 9 of the lower rail 8, presses the outer circumferential surface 10 of the rail 8 against the inner circumferential surface 14 of the cylinder 13, and The inner circumferential end of the lower surface 17 of 8 is pressed against the lower surface 18 of the ring groove 12 . In this way, oil can be properly scraped from the inner peripheral surface 14 of the cylinder 13 by the two upper and lower rails 7 and 8, and the upper and lower surfaces 16 and 18 of the ring groove 12 can be properly sealed.

FIG. 4 shows a combination oil ring with one thin rail and one expander. In FIG. 4, the expander 1A is the same as the expander 1 shown in the above example, except for the outer peripheral shape. That is,
The outer peripheral surface of this expander 1A is composed of one tapered surface 19 instead of a pair of upper and lower tapered surfaces. Tapered surface 19
The taper angle θ (see FIG. 5) is preferably 5 to 25 degrees. The thin rail 7 is the same as the rail 7 shown in the above example.

Therefore, as shown in FIG. 4, one rail 7 is placed in the ring groove 12 of the piston 11, and the expander 1A is placed on the inner circumferential side of the rail 7 to extend the one rail 7 outward. Stretch. That is, the tapered surface 19 of the outer circumference of the expander 1A presses against the inner circumferential surface 9 of the rail 7, presses the outer circumferential surface 10 of the rail 7 against the inner circumferential surface 14 of the cylinder 13, and also presses the outer circumferential surface 10 of the rail 7 against the inner circumferential surface 14 of the cylinder 13. The circumferential end is pressed against the upper surface 16 of the ring groove 12 of the piston 11, and the outer circumferential end of the lower surface 17 of the rail 7 is pressed against the lower surface 18 of the ring groove 12. In this way, the inner peripheral surface 14 of the cylinder 13 can be properly scraped with oil using one rail 7, and the upper and lower surfaces 14 of the ring groove 12 can be properly scraped with oil.
6 and 18 are also properly sealed.

When there are two rails, the expander may be configured as follows. That is, as shown in FIG. 6, a large number of trapezoidal notches 21 are formed continuously in the longitudinal direction on one side of the strip plate 20, and triangular protrusions 22 are formed on one side of the strip plate 20 in the longitudinal direction. Form a large number at equal intervals. Then, this strip plate 20 is bent and formed into an annular shape, and the upper and lower pieces are spaced apart from each other in the axial direction and alternately arranged in an annular shape, and are connected by an intermediate piece that extends in the axial direction. This constitutes an annular, axially corrugated expander with an abutment. In this case, the outer circumferential end surface of the intermediate piece forms a pair of upper and lower tapered surfaces (the end surfaces of the triangular protrusion form the pair of upper and lower tapered surfaces of the intermediate piece).

Further, when there is only one rail, the expander may be constructed in the same manner as described above. That is, as shown in FIG. 7, a large number of trapezoidal notches 24 are formed on one side of the strip plate 23 at equal intervals in the longitudinal direction, and the trapezoidal projections 2 are formed.
5 are formed in large numbers on one side of the strip plate 23 at equal intervals in the longitudinal direction, and the strip plate 23 is bent and formed into an annular shape.
An extract of an annular axial wave type with an abutment, in which upper pieces and lower pieces are spaced apart in the axial direction and arranged alternately in an annular shape, and are connected by an intermediate piece extending in the axial direction. Configure pandas. In this case, the outer circumferential end surface of the intermediate piece forms one tapered surface (each of the inclined end surfaces of the trapezoidal projecting piece forms one tapered surface of the intermediate piece).

[0020]

As explained above, according to the present invention, the rail is pressed against the inner peripheral surface of the cylinder and the ring groove surface by the tapered surface on the outer periphery of the expander, so that the oil scraping action and the sealing action of the ring groove surface can be achieved. Can be done properly. Even in the case of two rails, since no expander is inserted between the rails, the entire ring can be made thinner. Therefore, the piston can be made shorter and lighter. As a result, the engine can be made smaller and lighter, and fuel efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a combination oil ring when there are two rails, and showing a state in which the combination oil ring is installed in a ring groove.

FIG. 2 is a perspective view showing a portion of the expander in the above example.

FIG. 3 is a sectional view of the expander.

FIG. 4 is a sectional view showing an example of a combination oil ring when there is one rail, and showing a state in which the combination oil ring is installed in a ring groove.

FIG. 5 is a sectional view of the expander.

FIG. 6 is a plan view of a strip plate before forming an expander, showing another example in which there are two rails.

FIG. 7 is a plan view of a strip plate before forming an expander, showing another example in which there is one rail.

[Explanation of symbols]

1, 1A Expander 2 Upper piece 3 Lower piece 4 Intermediate piece 5, 6 Tapered surface 7, 8 rail 9 Inner peripheral surface of rail 10 Rail outer circumferential surface 11 Piston 12 Ring groove 13 Cylinder 14 Cylinder inner circumferential surface 15 Top surface of rail 16 Ring groove top surface 17　Rail bottom surface 18 Lower surface of ring groove 19 Tapered surface 20, 23 Band plate 21, 24 Notch 22, 25 Projection piece θ Taper angle

Claims (3)

[Claims] Claim 1: A combination oil ring that is installed in a piston ring groove of an internal combustion engine, and is made up of an annular thin rail with an abutment and an expander, the oil ring having an outer circumference of the expander. A combination oil ring characterized in that a provided tapered surface contacts the inner circumferential side of the rail and presses the rail against the inner circumferential surface of the cylinder and the ring groove surface. 2. A combination oil ring which is installed in a piston ring groove of an internal combustion engine, and which comprises a pair of annular upper and lower thin rails each having an abutment and an expander, and which is installed in a piston ring groove of an internal combustion engine. A combination oil ring characterized in that a pair of upper and lower tapered surfaces contact the inner peripheral side of the rail and press the rail against the inner peripheral surface of the cylinder and the ring groove surface. 3. The combination oil ring according to claim 1, wherein the tapered surface has a taper angle of 5 to 25 degrees.