JPH06174094A - Three-piece oil ring - Google Patents

Abstract

PURPOSE:To depress excessive oil consumption by constantly providing, regardless of a variation in spacer shape, expected degree of circumferential tensile force of a side rail upper highly affected by oil consumption in a three-piece oil ring suitable for mounting in an engine piston. CONSTITUTION:In a three-piece oil ring 9 comprising a pair of ring side rails 4, 5, and a ring spacer 6 coaxially provided between a pair of the side rails 4, 5, at the spacer 6 are formed a pair of side rail inner periphery locking parts 6a locked with the inner peripheral parts of a pair of the side rails 4, 5, respectively. Each side rail inner periphery locking part 6a is provided in asymmetrical to the axial orthogonal central face S of the spacer 6 so that the circumferential tensile force of a side rail upper 4 may be higher than that of a side rail lower 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-piece oil ring suitable for mounting on an engine piston.

[0002]

2. Description of the Related Art FIG. 5 is a cross-sectional view of a piston and a cylinder portion of a conventional 4-cycle reciprocating engine equipped with a three-piece oil ring. As shown in FIG.
The piston 51 has three ring grooves,
In these ring grooves, the top ring 52, the second ring 53, and the
3-piece oiling 59 composed of side rail upper 54, side rail lower 55, and spacer 56
However, as the piston 51 moves, the cylinder block 57
Each is fitted to slide with the liner.

Here, the top ring 52 and the second ring 53 have a sealing function for enhancing airtightness. Further, in the three-piece oil ring 59, the side rail lower 55 has a main function of scraping off oil attached to the cylinder liner, while the side rail upper 54 has not only a function of scraping oil but also a sealing function. have.

Further, in the spacer 56, an equal circumferential tension is generated in the side rail upper 54 and the side rail lower 55, and both of them are pressed against the wall surface of the ring groove with an equal force. Peripheral locking part 56a
Is a plane S perpendicular to the center axis of the cylinder and equally divided into two with respect to the thickness of the spacer 56 (hereinafter, the central plane S orthogonal to the axis
(See FIG. 5).
reference).

Reference numeral 58 is an oil hole. With such a configuration, as the piston 51 moves, the top ring 52, the second ring 53, the side rail upper 5
4. While the side rail lower 55 slides on the cylinder liner, the top ring 52 and the second ring 53 have a sealing function, the side rail upper 54 has a sealing function and a function of scraping off oil adhered to the cylinder liner, and the side rail lower 55 Responsible for scraping off oil adhering to the cylinder liner.

The side rail inner periphery locking portion 56a of the spacer 56 may be a ring-shaped continuous surface along the inner periphery of the side rail upper 54 or the side rail lower 55, and FIG. It may be in the form of protrusions with a space (corrugation) as shown.

[0007]

However, in such a conventional three-piece oil ring, the spacer is made of sheet metal, but the bending angle has a width within an appropriate angle range, so that the shape is changed. There are variations, and depending on the product, the side rail lower may be installed so that it projects more than the side rail upper.In this case, the tension in the circumferential direction of the side rail upper, which greatly affects oil consumption, There is a problem that the desired size cannot be obtained due to the influence of the side rail lowers, resulting in extra oil consumption.

The present invention was devised in view of the above problems, and the tension in the circumferential direction of the side rail upper, which greatly affects the oil consumption, is always the desired size regardless of variations in the spacer shape. By making it possible to obtain, it was possible to suppress the excessive oil consumption, 3
The purpose is to provide a peace oil ring.

[0009]

Therefore, the three-piece oil ring of the present invention is a three-piece oil ring including a pair of annular side rails and an annular spacer coaxially interposed between the pair of side rails. In the oil ring, a pair of side rail inner peripheral locking portions that respectively lock with the inner peripheral portions of the pair of side rails are formed in the spacer, and the tension in the circumferential direction of the side rail upper is increased by the side rail lower. Each of the side rail inner peripheral locking portions is asymmetrically provided with respect to the center plane orthogonal to the axis of the spacer so as to be larger than the tension in the circumferential direction.

The three-piece oil ring of the present invention is
In a three-piece oil ring consisting of a pair of annular side rails and an annular spacer coaxially interposed between the pair of side rails, the spacer is locked to the spacers and to the inner peripheral portions of the pair of side rails. A pair of side rail inner circumferential locking portions are formed, and the ring widths of the pair of side rails are set so that the tension in the circumferential direction of the side rail upper is greater than the tension in the circumferential direction of the side rail lower. The feature is that they are different.

[0011]

In the above-described three-piece oil ring of the present invention, a pair of side rail inner peripheral locking portions provided asymmetrically with respect to the central plane orthogonal to the axis of the spacer, or a pair of annular side rails having different ring widths. By using, the circumferential tension of the side rail upper becomes larger than the circumferential tension of the side rail lower.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. (A) Description of First Embodiment FIG. 1 is a sectional view of a piston and a cylinder of a four-cycle reciprocating engine equipped with a three-piece oil ring as a first embodiment of the present invention. In the case of the first embodiment Also, as shown in FIG. 1, the piston 1
In the three ring grooves provided in the top ring 2, the second ring 3, and the side rail upper 4, the side rail lower 5, and the spacer 6 are arranged in this order from the side closer to the piston head. 9
Are fitted so as to slide with the liner of the cylinder blog 7 as the piston 1 moves.

Here, the top ring 2 and the second ring 3 have a sealing function for improving airtightness, and in the three-piece oil ring 9, the side rail lower 5 mainly scrapes off the oil attached to the cylinder liner. On the other hand, the side rail upper 4 has not only the oil scraping function but also the sealing function. In addition, 8 is an oil hole.

Next, FIG. 2 shows a diagram for explaining the three-piece oil ring of this embodiment. In the present embodiment, as shown in FIG. 2, the spacer 6 is provided at a pair of side rail inner peripheral locking portions that are locked to the inner peripheral portions of the side rail upper 4 and the side rail lower 5, The reference point diameter of the side rail inner circumference locking portion 6a on the side rail upper 4 side is r ₁ , the inclination angle is θ ₁ , the reference point diameter of the side rail inner circumference locking portion 6a on the side rail lower 5 side is r ₂ , When the inclination angle is θ ₂ , it is formed so as to satisfy r ₁ > r ₂ or θ ₁ <θ ₂ . As a result, each side rail inner peripheral locking portion 6a is provided asymmetrically with respect to the center plane S orthogonal to the axis of the spacer 6.

The side rail upper 4 and the side rail lower 5 are assumed to have the same shape. With the above configuration, the following actions occur. FIG. 3 is a diagram illustrating a force acting on the siderail upper 4. As shown in FIG. 3, the force F ₁ exerted on the side rail upper 4 from the side rail inner peripheral locking portion 6 a of the spacer 6 is the force t ₁ for pressing the side rail upper 4 against the wall of the ring groove and the side rail upper 4. Force T that is proportional to the tension in the circumferential direction
It can be divided into two components called ₁ . Similarly, the spacer 6
From the side rail inner periphery locking portion 6a of the side rail lower 5
Let F ₂ be the force acting on F, and let t ₂ and T ₂ be the _two force components obtained by decomposing F ₂ in the same manner as F ₁ .

In this embodiment, the spacer 6 is r₁> R₂To
Or θ₁<Θ₂It is formed so that
No, r₁> R₂In case of (θ₁= Θ₂And
), F ₁, F₂The size relationship of F is₁> F₂Will be
And T₁= F₁cos θ₁, T₂= F₂cos θ₂Yo
, T₁> T₂And therefore the siderail upper 4
Circumferential tension generated on the side rail
Greater than circumferential tension.

Next, when θ ₁ <θ ₂ , (r ₁ = r ₂
As is), the magnitude of F ₁ and F ₂ are substantially equal, a T _1> T ₂ from the relation theta ₁ and theta _2, thus circumferential tension generated in the side rail upper 4 siderail lower 5 It becomes larger than the tension in the circumferential direction. Thus, in any case of r ₁ > r ₂ and θ ₁ <θ ₂ ,
Since the circumferential tension generated in the siderail upper 4 becomes larger than the circumferential tension generated in the siderail lower 5, the siderail lower 5 eliminates the influence, and the circumferential tension generated in the siderail upper 4 is expected. Can be obtained in size. As a result, the side rail upper 4
The cylinder liner's oil removal function and the sealing function of the cylinder can be fully exerted, and as a result, the excessive oil consumption can be suppressed.

It is of course possible to form the spacers 6 so that r ₁ > r ₂ and θ ₁ <θ ₂ . (B) Description of Second Embodiment FIG. 4 is a view for explaining a three-piece oil ring as a second embodiment of the present invention, and the three-piece oil ring 9 according to the second embodiment is also shown in FIG. In such a piston, it is used in the same manner as in the first embodiment described above, but in the case of this embodiment, the spacer 6 has a pair of side rail inner peripheral locking portions 6a in the center orthogonal to the axis line, as in the conventional example. Although formed symmetrically with respect to the surface S, the ring width L ₁ of the side rail upper 4 is equal to the ring width L of the side rail lower 5.
Greater than ₂ . That is, the side rail upper 4 and the side rail lower 5 are formed such that the inner diameter of the side rail upper 4 is smaller than the inner diameter of the side rail lower 5.

The above-mentioned structure produces the following effects. As in the first embodiment, the force F ₁ acting on the siderail upper 4 and its component forces t ₁ and T ₁ , and the force F ₂ acting on the siderail lower 5 and its component forces t ₂ and T ₂ are used. explain. The inner diameter of the side rail upper 4 is the side rail lower 5
Despite being smaller than the inner diameter of F, the pair of side rail inner peripheral locking portions 6a provided on the spacer 6 are symmetrical with respect to the center plane S orthogonal to the axis, and therefore the relationship between the sizes of F ₁ and F ₂ is F _{Since 1} > F ₂ and therefore T ₁ > T ₂ , the circumferential tension generated in the siderail upper 4 is larger than the circumferential tension generated in the siderail lower 5. Therefore, similarly to the first embodiment described above, the circumferential tension generated in the side rail upper 4 can be obtained with a desired magnitude. As a result, the cylinder liner adhering oil scraping function and the sealing function of the side rail upper 4 can be sufficiently exerted, and as a result, an excessive oil consumption amount can be suppressed.

(C) Others In each of the first and second embodiments described above, the pair of side rail inner peripheral locking portions 6a provided on the spacer 6 is formed by the side rail upper 4 and the side rail. The surface may be continuous in a ring shape along the inner circumference of the lower 5, or may be a protruding shape (corrugated shape) with intervals as shown in FIG. 7.

[0021]

As described above in detail, according to the three-piece oil ring of the present invention, the circumferential tension generated in the siderail upper is made larger than the circumferential tension generated in the siderail lower, so that the siderail is formed. Since the side rail lower does not affect the circumferential tension generated in the upper, the circumferential tension generated in the side rail upper, which greatly affects the oil consumption, can be obtained with the desired magnitude regardless of the spacer shape variation. As a result, the cylinder liner adhering oil scraping function and the sealing function of the side rail upper can be sufficiently exerted, and as a result, there is an advantage that an excessive oil consumption amount can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of a piston and a cylinder portion of a four-cycle reciprocating engine equipped with a three-piece oil ring as a first embodiment of the present invention.

FIG. 2 is a diagram showing a main part of the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a force acting on a side rail upper.

FIG. 4 is a diagram showing a main part of a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a piston and a cylinder portion of a 4-cycle reciprocating engine to which a conventional 3-piece oil ring is attached.

FIG. 6 is a diagram illustrating a conventional three-piece oil ring.

FIG. 7 is a perspective view showing an example of the shape of a spacer.

[Explanation of symbols]

 1,51 Piston 2,52 Top ring 3,53 Second ring 4,54 Side rail upper 5,55 Side rail lower 6,56 Spacer 6a, 56a Side rail inner circumference locking part 7,57 Cylinder block 8,58 Oil hole 9,59 3-piece oil ring S S-axis orthogonal center plane

Claims (2)

[Claims] 1. A three-piece oil ring comprising a pair of annular side rails and an annular spacer coaxially interposed between the pair of side rails, wherein the spacer has an inner circumference of the pair of side rails. A pair of side rail inner circumferential locking portions that are respectively locked to the side portions are formed, and the side rail uppers are circumferentially tensioned to be larger than the circumferential tension of the side rail lowers. A three-piece oil ring, wherein the rail inner peripheral locking portion is provided asymmetrically with respect to the center plane orthogonal to the axis of the spacer. 2. A three-piece oil ring comprising a pair of annular side rails and an annular spacer coaxially interposed between the pair of side rails, wherein the spacer has an inner circumference of the pair of side rails. A pair of side rail inner circumferential engaging portions that are respectively engaged with the side rails are formed so that the tension in the circumferential direction of the side rail upper is greater than the tension in the circumferential direction of the side rail lower. A 3-piece oil ring characterized by different rail ring widths.