JPH0587240A - Thin width three-piece oil ring - Google Patents

Abstract

PURPOSE:To provide such an oil ring as holding the same sealability equal to the conventional one even if the extent of tension in a spacer expander is made lower than that of those heretofore in use, in the thin width 3-piece oil ring that is made up of combining the spacer expander and two vertical side rails formed out of shape steel. CONSTITUTION:A spacer expander 10 is formed out of T-formed shape steel whose section is almost tilted sidelong, and end parts are alternately bent up and down and then vertical pads 16, 16' are formed in the inner circumferential side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil ring used in an internal combustion engine.
The present invention relates to an improvement of a thin three-piece oil ring including a spacer expander formed of a mold steel and upper and lower side rails.

[0002]

2. Description of the Related Art The oil ring shown in FIG.
Proposed as an improvement of the thin three-piece oil ring known by Japanese Patent No. 19653 (Japanese Patent Application No. 2-19060)
The oil ring is formed of a shaped steel material having a substantially H-shaped cross section, and the spacer expander 10 is a hollow annular body having slits 11 alternately cut from the inner peripheral side and the outer peripheral side. Equipped with two side rails 20 and 20 'assembled so that the expander is sandwiched from above and below.
The side rail pressing surfaces 15 and 15 'were provided on the outer peripheral side of the, and the side rail pressing surfaces 15 and 15' were formed to be inclined surfaces whose roots were outward. This oil ring had good sealing performance and side rail posture stability in a wide range of rotation from low speed to high speed.

[0003]

However, in the oil ring shown in FIG. 1, the inner peripheral enlarged portion 13 has upper and lower side rails.
Since it is the upper and lower pads themselves that support the 20 and 20 ', the wall thickness is thick, so the rigidity is high, and the degree of freedom as a pad that supports the side rails was small. As a result, with the conventional oil ring, when the deformation of the cylinder inner peripheral surface is large, the side rail cannot follow the cylinder inner peripheral surface,
The oil scraping function could not be satisfied. In addition, it was not possible to obtain the high sealing property required for engine braking of automobiles. In order to satisfy this, the spacer expander having high tension increases the friction of the oil ring, which adversely affects the fuel economy and the high output of the engine.

The present invention has been made in order to solve this problem, and an object thereof is to be required at the time of engine braking without applying a high tension to the spacer expander formed from the die steel material. It is to provide a thin three-piece oil ring that can maintain high sealing performance.

[0005]

In order to achieve the above object, the means adopted by the present invention is, as shown in FIGS. 2 and 3, a slit 11 which is alternately cut from the inner peripheral side and the outer peripheral side. An oil ring consisting of a truncated annular spacer expander and two side rails 20 and 20 'which are combined so as to sandwich the spacer expander from above and below. Form the expander, form the side rail bearing surfaces 14, 14 'above and below the outer peripheral side enlarged portion 12 of the spacer expander, and alternately bend the inner peripheral side end portion 17 of the spacer expander that is extended up and down. Upper and lower pads that press the side rails 1
6 and 16 'are formed.

[0006]

The pad is formed by bending the extended end of a T-shaped shaped steel material having a cross section with a substantially horizontal cross section. The thickness of the pad is fine, so its rigidity is small and it is relatively easily elastically deformed. The degree of freedom of displacement is also large. The elasticity of the pad, which has a large degree of freedom, presses the side rail against the inner peripheral surface of the cylinder to reliably follow the deformation of the inner peripheral surface of the cylinder, so that the oil ring maintains a good sealing property. Therefore, even if the tension of the spacer expander is made smaller than in the conventional case, the oil ring can have a high sealing property required for engine braking. By reducing the tension of the spacer expander, the friction of the oil ring is reduced, which contributes to fuel efficiency and high output of the engine.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An oil ring of the present invention will be described based on the embodiments shown in the drawings. As shown in FIG. 2, the three-piece combined oil ring of the present invention includes a spacer expander 10 having a truncated annular body formed of a T-shaped steel material having a substantially horizontal cross section, and two side rails 20 sandwiching the spacer expander 10 from above and below. , 20 ', and the spacer expander 10 having an open torus has slits 11 that are alternately cut from the inner peripheral side and the outer peripheral side.

As shown in FIG. 2 and FIG. 3, the oil ring is installed in the oil ring groove 32 of the piston 30, and the cylinder is
Fitted in 40. The spacer expander 10 includes side rail bearing surfaces 14 and 14 above and below the outer peripheral side enlarged portion 12, and the inner peripheral side extended end portion 17 is alternately bent up and down to form an upper pad 16 and a lower pad 16 '. The upper and lower pads 16, 16 'are provided with pressing surfaces 15, 15' on the outside. The side rail bearing surfaces 14 and 14 'support the side rails 20 and 20' in the axial direction, and the side rail pressing surfaces 15 and 15 'connect the side rails 20 and 20' to the cylinder inner peripheral surface 42 and the oil ring groove upper and lower surfaces. Press to. pad
Since 16 and 16 'are formed by bending up and down by plastic working, they have low rigidity and large movement due to elastic deformation. Therefore, the followability of the side rails 20 and 20 'backed up by this pad with respect to the inner peripheral surface 42 of the cylinder 40 is remarkably better than that of the one having a large rigidity, and accordingly a high sealing property is obtained.

Side rail pressing surfaces of the upper and lower pads 16, 16 '
Reference numerals 15 and 15 'are inclined surfaces whose bases are outwardly protruded, and side rail bearing surfaces 14 and 14' are inner peripheral edges rather than outer peripheral edges 14a and 14'a.
14b and 14'b are slopes close to the center. When the spacer expander 10 is stretched in the radial direction, the side rail pressing surface 1
5, 15 'presses the inner peripheral ends of the side rails 20, 20', but the pressing force orthogonal to the inclined surface is the axial component force and the radial component force, and the axial component force is the side rail 20, 20 'is pressed and brought into close contact with the upper and lower surfaces 33, 33' of the oil ring groove 32.

In the conventional oil ring, since the pad is less elastically deformed, the side rail is pressed against the inner peripheral surface of the cylinder by the tension of the spacer expander to maintain the sealing property. 16, 16
′ Is elastically deformed, so that the side rails 20 and 20 ′ follow the cylinder inner peripheral surface 42 to maintain the sealing property, so that the tension of the spacer expander 10 can be significantly reduced as compared with the conventional one. .. Spacer expander
When the tension of 10 is reduced, the friction of the oil ring is reduced, so that the fuel consumption of the engine is reduced and the output of the engine is increased.

[0011]

As described above, the oil ring of the present invention is formed by forming the spacer expander from the steel material having the T-shaped cross section by laying it substantially sideways and by bending the inner peripheral side end portions thereof up and down alternately to form the upper and lower pads. In contrast to the conventional oil ring that has a high rigidity and hardly moves elastically by forming the spacer expander from the conventional H-shaped steel material and using the inner peripheral side enlarged portion as the upper and lower pads, the upper and lower pads of the present invention are Since the rigidity is low, the side rail can sufficiently follow the inner peripheral surface of the cylinder by its elastic movement. Therefore, the oil ring of the present invention maintains the same sealability even when the tension of the spacer expander is made lower than that of the conventional one. If the tension of the spacer expander is reduced,
Since the friction of the oil ring is reduced, the oil ring of the present invention has an excellent effect of contributing to fuel saving and high output of the engine.

[Brief description of drawings]

FIG. 1 is a partial perspective view of a conventional oil ring,

FIG. 2 is a partial perspective view of an oil ring according to an embodiment of the present invention,

3 is a cross-sectional view of a main part of a piston equipped with the oil ring of FIG.

[Explanation of symbols]

10: Spacer expander, 11: Slit, 12: Enlarged outer peripheral side, 14: Side rail bearing surface, 15: Side rail pressing surface, 16: Pad, 17: Inner peripheral side end, 20: Side rail

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsushi Ishihara 5-2-6 Honmachi Nishi, Yono City, Saitama Japan Piston Ring Co., Ltd.

Claims (1)

[Claims] 1. A spacer expander (10), which is a ring-shaped annular body having slits (11) alternately cut from the inner peripheral side and the outer peripheral side, and a spacer expander which is combined so as to sandwich the spacer expander from above and below. In an oil ring composed of a number of side rails (20, 20 '), the spacer expander is formed of a T-shaped steel material having a substantially horizontal cross section, and the outer peripheral side enlarged portion (12) of the spacer expander is vertically Rail support surfaces (14, 14 ') are provided, the inner peripheral side end (17) is alternately bent up and down to form upper and lower pads (16, 16'), and side rail pressing surfaces (16, 16 ') are formed on the outer peripheral side of the pads. 15, 15
A thin three-piece oil ring characterized by the provision of ').