KR20160124217A - Oil Ring - Google Patents

Abstract

And a pair of leg portions 12 and 13 integrally provided on both sides of the web portion 11 in the axial direction of the web portion 11. The leg portions 10a and 10b are formed integrally with the web portions 11, And a coil expander 20 mounted on an inner portion in the radial direction of the oil ring body 10 to press the oil ring body 10 toward the outside in the radial direction The outer peripheral surface 12b of the oil ring 1 facing the radially outer side of the one rail portion 12 and the outer peripheral surface 13b facing the radially outer side of the other rail portion 13, The axial distance D1 between the axially outer edges of the oil ring body 10 is set to 70% or less of the axial width dimension of the oil ring body 10. [

Description

Oil Ring

The present invention relates to an oil ring used in a piston of a reciprocating engine (reciprocating internal combustion engine), and more particularly, to a ring-shaped oil ring body having an annular shape having an end gap and having a coil expander To a two-piece type.

BACKGROUND ART Conventionally, in a piston of a reciprocating engine, an oil ring for sealing a lubricating oil is mounted in addition to a compression ring for sealing a combustion gas.

There are three-piece types mainly used for gasoline engines and two-piece types mainly used for diesel engines. Due to the demand for low fuel consumption and the like, the oil ring can be further thinned in the axial direction A two-piece type oil ring has been used.

Such two-piece type oil rings include, for example, as described in Patent Document 1, a pair of oil rings having a web portion provided with a through hole and a pair of rails integrally provided on both sides (upper and lower sides) And a coil expander which is mounted on the radially inner portion of the oil ring body and presses the oil ring body toward the radially outward side. In this case, the oil ring body is formed in a toroidal shape having a miter, is expanded by being pressed toward the radially outer side by the coil expander, and the oil ring body expands, When the piston reciprocates, the oil staying between the pair of levers is applied to the inner surface of the cylinder, and at the same time, the excess oil is scraped off by the rail portion And is discharged through the through holes to form an oil film having an appropriate thickness on the inner surface of the cylinder.

JP-A-61-45172

In the above conventional oil ring, the surface pressure against the inner surface of the cylinder is set to be several times higher than that of the compression ring in order to effectively suppress the oil rise of the lubricating oil and reduce the oil consumption.

On the other hand, from the viewpoint of fuel efficiency of the engine, it is required to reduce the friction of the oil ring against the inner surface of the cylinder. For this purpose, it is necessary to decrease the surface pressure of the sealing portion against the inner surface of the cylinder by making the oil ring low-

However, when the oil ring is made stockpile, the followability of each rail portion when the piston is tilted (vibrates) is lowered and the oil consumption amount is increased. Therefore, both reduction in friction due to storage capacity and reduction in oil consumption are both achieved It was difficult.

An object of the present invention is to solve the above problems and to provide an oil ring having a storage capacity and excellent oil consumption reduction capability.

The inventors of the present invention have studied the means of solving the above-mentioned problems, and it is important to make the oil ring main body to have a shape with high followability with respect to the inner surface of the cylinder in order to increase the capacity and the oil consumption reduction capability with a storage capacity. The axial distance between the axially outer rim of the outer circumferential surface facing the radially outer side and the axially outer rim of the outer circumferential surface facing the radially outer side of the other rail portion is not more than 70% And the present invention has been completed.

That is, the oil ring of the present invention comprises an oil ring body formed into a toric shape having a web portion provided with a through hole and a pair of rail portions integrally provided on both sides in the axial direction of the web portion, And a coil expander mounted on a radially inward portion of the oil ring body for pressing the oil ring body toward the radially outer side, the oil ring comprising: an axially outer rim of an outer circumferential surface of the one of the rails facing radially outward; And an axial outer side edge of the outer peripheral face of the other of the rails facing the radially outer side is 70% or less of an axial width dimension of the oil ring body.

In the above configuration, the "annular shape with the oil ring main body having the mating mouth" means that the annular oil ring body is cut in a part in the circumferential direction thereof and the C And is formed in a shape of a letter.

Further, in the above configuration, it is preferable that "the axial distance between the axially outer rim of the outer circumferential surface of the one of the rails facing the radially outer side and the axially outer rim of the outer circumferential surface of the other rac portion facing the radially outer side Means the distance between the outer circumferential surface of one rail part and the outer circumferential surface of the other rail part in the axial direction.

In the present invention, it is preferable that the axial width dimension of the outer circumferential surfaces of the pair of rails is in the range of 5.0% to 10.0% of the axial width dimension of the oil ring body. And preferably in the range of 5.0% to 8.0%.

Further, in the present invention, it is preferable that, in the above configuration, the thickness dimension of the web portion in the radial direction is 25% or less of the radial thickness dimension of the oil ring body.

Further, according to the present invention, in the above-described structure, the radial direction center-of-gravity position of the oil expander main body in a section perpendicular to the circumferential direction of the coil expander from the radial direction center- Position is less than 55% of the radial thickness dimension of the oil ring body.

According to the present invention, by making the oil ring main body to have a high followability with respect to the inner surface of the cylinder, it is possible to reduce the oil consumption by reducing the friction of the oil ring with respect to the inner surface of the cylinder while effectively following the oil ring body to the inner surface of the cylinder. have.

1 is a plan view of an oil ring according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. Fig.
Fig. 3 is a view of a part of the oil ring shown in Fig. 1 viewed from the outside in the radial direction. Fig.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The oil ring 1, which is an embodiment of the present invention shown in Fig. 1, is also called oil control ring and is used, for example, mounted in a ring groove formed on the outer peripheral surface of a piston of a diesel engine. The oil ring 1 is of a two-piece type and has an oil ring body 10 and a coil expander 20.

The oil ring main body 10 is formed in a C-shape in which a toric shape having a mouth by a steel material, that is, a portion in the circumferential direction is cut and the cut portion is formed as a crown 10a, 10b. The grooves 10a and 10b are formed so that the oil ring main body 10 can elastically deform such that the grooves 10a and 10b are distant from each other in the circumferential direction and can expand toward the radially outer side. Further, when the oil ring main body 10 is disposed in the cylinder while being mounted on the piston, the grooves 10a and 10b are closed to form a substantially toric shape, so that oil can be sealed over the entire circumference of the piston.

2 and 3, the oil ring main body 10 has a web portion 11, an upper rail portion 12 and a lower rail portion 13, have.

The web portion 11 is formed in a thin cylindrical shape, and a plurality of air holes 14 are arranged side by side in the circumferential direction at a central position in the axial direction. Each of the through holes 14 is formed as a long hole extending in the circumferential direction, and penetrates the web portion 11 in the radial direction.

The upper rail part 12 is provided integrally with the web part 11 on one side in the axial direction of the web part 11 and the lower rail part 13 is provided on the other side in the axial direction of the web part 11 And is integrally provided with the web portion 11. [ The thickness dimension in the radial direction of each of the rail parts 12 and 13 is larger than the thickness dimension in the radial direction of the web part 11 and the width of the web part 11 in the radial direction middle part of each of the rail parts 12 and 13 Are arranged in the corresponding rails (12, 13). The portions protruding outward in the radial direction from the web portions 11 of the rails 12 and 13 are lands 12a and 13a and the outer peripheral surfaces 12b and 12b, 13b are each a sliding surface in contact with the inner surface of the cylinder. Each of the lands 12a and 13a has a substantially trapezoidal section in which the axial width gradually narrows from the base end side toward the outer peripheral faces 12b and 13b side and each of the outer peripheral faces 12b and 13b And are disposed to be offset from the axial center of the oil ring body 10 in the axial direction with respect to both ends in the axial direction of the oil ring body 10.

The outer peripheral surfaces (sliding surfaces) 12b and 13b of the rail portions 12 and 13 are provided with hard films by various surface treatments such as hard chrome plating, nitriding (GNR), and ion plating (PVD) .

As shown in Fig. 2, a mounting groove 15 for mounting the coil expander 20 is provided in the radially inner portion (inner circumferential surface) of the oil ring body 10. The mounting groove 15 has a semicircular concave section extending from the web portion 11 to both rail portions 12 and 13 and extends along the entire circumference of the oil ring body 10 along the circumferential direction.

1, the coil expander 20 is formed by winding a wire material formed of a steel material or the like in a coil shape and then forming both ends thereof in a toroidal shape. The coil expander 20 is elastically deformable toward the inward and outward directions in the radial direction. The outer diameter of the coil expander 20 in its natural state is larger than the inner diameter of the oil ring body 10. 2, the coil expander 20 is attached to the mounting groove 15 of the oil ring body 10 in a state elastically deformed in the diameter-reducing direction, To the outside in the radial direction.

On the other hand, the radius viewed in the direction perpendicular to the circumferential direction of the coil expander 20 is slightly smaller than the radius of the mounting groove 15 of the oil ring body 10.

When the oil ring 1 having such a configuration is mounted in the ring groove of the piston and disposed in the cylinder, the oil ring body 10 is expanded in the radially outward direction by being pressed against the coil expander 20 in addition to its own elasticity And the outer circumferential surfaces 12b and 13b of the respective rails 12 and 13 come into contact with the inner surface of the cylinder at a predetermined surface pressure. When the piston reciprocates, the oil staying between the upper and lower races 12, 13 is applied to the inner surface of the cylinder, and the excess oil is scraped off by the rails 12, 13, Excess oil between the oil holes 12 and 13 can be guided to the oil hole provided in the ring groove of the piston through the air hole 14 to form an oil film having an appropriate thickness on the inner surface of the cylinder.

As shown in Fig. 2, in the oil ring 1 of the present invention, the elastic force of the coil expander 20 and the tensile force of the coil expander 20 (the elastic force toward the radially outward side) The outer peripheral face of the outer peripheral face 12b of the upper rail portion 12 and the outer peripheral face 13b of the lower rail portion 13 are formed so as to be able to reduce the oil consumption amount of the engine, Is set to be 70% or less of the axial width dimension (w1) of the oil ring body (10) in the axial direction. That is, the axial distance D1 between the outer circumferential surface 12b of the upper rail 12 and the outer circumferential surface 13b of the lower rail portion 13, The width of the oil ring body 10 is set to be not more than 70% of the axial width dimension w1 of the oil ring body 10 so that the oil ring body 10 is fitted to the cylinder inner face with a width narrower than the axial width dimension w1 of the oil ring body 10 . Particularly, in the present embodiment, the axial distance D1 is set to 66% of the axial width dimension w1 of the oil ring main body 10.

With this configuration, the followability of the oil ring main body 10 to the inner surface of the cylinder when the piston is tilted (vibrated) can be enhanced. That is, when the piston is tilted, one of the pair of rails 12 and 13 comes into contact with the inner surface of the cylinder and the other comes off from the inner surface of the cylinder. At this time, It is possible to prevent the axial outer edge of the outer circumferential surface 12b of the upper rail 12 and the lower outer rail 12b of the upper rail 12 from being displaced in the axial direction, As compared with the case where the axial distance D1 between the axially outer rims of the outer circumferential surface 13b of the part 13 is equal to the axial width dimension w1, The distance can be reduced. Therefore, even if the oil ring 1 is made to have a storage capacity and the friction with respect to the cylinder inner surface is reduced, the oil ring body 10, that is, the respective rail portions 12 and 13, The outer circumferential surfaces 12b and 13b of the outer cylinder 12 can be effectively followed by the inner cylinder surface. Therefore, the oil consumption of the engine in which the oil ring 1 is used can be reduced. As described above, since the oil ring body 10 can effectively follow the inner surface of the cylinder, even if the oil ring 1 is made to have a storage capacity, such as using a coil spring having a smaller elastic force as the coil expander 20, The oil consumption amount of the oil ring 1 can be reduced.

The axial distance between the axially outer edge of the outer circumferential surface 12b of the upper rail part 12 and the axially outer edge of the outer circumferential surface 13b of the lower rail part 13 in the oil ring 1 of the present invention, The axial width dimension w2 of the outer circumferential surface 12b of the upper rail portion 12 is set to be smaller than the axial width dimension w1 of the oil ring body 10 in the axial direction, And the axial width dimension w2 of the outer circumferential face 13b of the lower rail part 13 are preferably set within a range of 5.0% to 10.0% of the axial width dimension w1 of the oil ring body 10 Do. For example, in the present embodiment, the axial width dimension w2 is set to 8.0% of the axial width dimension w1 of the oil ring body 10.

The axial width w2 of the outer circumferential surfaces 12b and 13b of the rails 12 and 13 is set within the range of 5.0% to 10.0% of the axial width w1 of the oil ring body 10 The outer circumferential surfaces 12b and 13b of the rails 12 and 13 are brought into contact with the inner surface of the cylinder with an appropriate surface pressure against the size of the oil ring body 10 without using the coil expander 20 having an excessively large elastic force . Therefore, as described above, the axial distance D1 between the axially outer rim of the outer peripheral surface 12b of the upper rail 12 and the axially outer rim of the outer peripheral surface 13b of the lower rail 13, The outer circumferential surfaces 12b and 13b of the rails 12 and 13 can be prevented from being deformed in the axial direction by setting the outer circumferential surfaces 12b and 13b of the oil ring body 10 to 70% It is possible to reduce the oil consumption of the oil ring 1 by further reducing the oil rise by contacting the inner surface with a predetermined surface pressure.

On the other hand, the axial distance D1 is set to 70% or less of the axial width dimension w1 of the oil ring main body 10 and the outer peripheral surfaces 12b and 13b of the rail portions 12 and 13 By setting the axial width dimension w2 of the upper rail 12 within the range of 5.0% to 10.0% of the axial width dimension w1 of the oil ring main body 10, the outer peripheral surface 12b of the upper rail 12, The interval between the outer circumferential surfaces 13b of the rail portion 13 is set to be not more than 60% of the axial width dimension w1 of the oil ring main body 10. [ In this case, the distance between the outer peripheral surface 12b of the upper rail part 12 and the outer peripheral surface 13b of the lower rail part 13 is set to 60% or less of the axial width dimension w1 of the oil ring main body 10 The opening area of the air hole 14 provided in the web portion 11 is set to be equal to or larger than 20% of the width dimension w1 of the axial direction so that the followability with respect to the cylinder inner surface of the oil ring body 10 is ensured, It can be ensured sufficiently.

The axial distance between the axially outer edge of the outer circumferential surface 12b of the upper rail part 12 and the axially outer edge of the outer circumferential surface 13b of the lower rail part 13 in the oil ring 1 of the present invention, The thickness dimension t2 in the radial direction of the web portion 11 is set to be not more than 70% of the axial width dimension w1 of the oil ring main body 10, Of the thickness t1 in the radial direction. For example, in the present embodiment, the radial thickness dimension t2 is set to 20% of the radial thickness dimension t1 of the oil ring main body 10.

In this way, by setting the radial thickness dimension t2 of the web portion 11 to 25% or less of the radial thickness dimension t1 of the oil ring body 10, the web portion 11, that is, the oil ring body 10 When the piston is tilted (vibrated), the oil ring main body 10 is pressed against the outer circumferential surfaces 12b and 13b of the rail portions 12 and 13 with the web portion 11 as the center, It is possible to easily deform (warp) the gap between the first and second plates. Therefore, when the web portion 11 is deformed due to the tilting of the piston due to the radial load, the outer peripheral surfaces 12b and 13b of the rails 12 and 13 on the side remote from the cylinder inner surface approach the inner surface of the cylinder, The followability of the ring body 10 with respect to the inner surface of the cylinder can be further improved and the oil consumption of the oil ring 1 can be further reduced.

By setting the radial thickness t2 of the web portion 11 to 25% or less of the radial thickness dimension t1 of the oil ring body 10 as described above, It is possible to increase the space between the lower side rails 13 and to increase the oil discharge performance from the air hole 14 provided in the web portion 11. [ The axial distance D1 between the outer circumferential surface 12b of the upper rail part 12 and the outer circumferential surface 13b of the lower rail part 13 in the axial direction is made larger than the axial distance D1 of the oil ring body 10 Even if the space between the upper rail part 12 and the lower rail part 13 is narrowed by enlarging the corresponding space and setting the oil in the space to be smaller than 70% of the axial width dimension w1, Can efficiently be discharged from the air hole (14) of the main body (11). Therefore, even if the axial distance D1 is set to 70% or less of the axial width dimension w1 of the oil ring main body 10, the distance between the upper rail part 12 and the lower rail part 13 It is possible to efficiently discharge the oil in the space to reduce the oil stay in the space and to further reduce the oil consumption of the oil ring 1.

The thickness t2 in the radial direction of the web portion 11 is preferably 25% or less of the thickness t1 in the radial direction of the oil ring body 10 and 10% or more. Thus, it is possible to secure the strength of the web portion 11 while ensuring the deformability of the oil ring body 10, and to prevent breakage of the oil ring body 10.

Further, in the oil ring 1 of the present invention, the axial distance between the axially outer rim of the outer circumferential surface 12b of the upper rail part 12 and the axially outer rim of the outer circumferential surface 13b of the lower rail part 13, In addition to the configuration in which the direction distance D1 is set to be 70% or less of the axial width dimension w1 of the oil ring body 10, the diameter of the oil ring body 10 in the cross section perpendicular to the circumferential direction thereof The radial distance D2 from the directional center of gravity position G1 to the radial direction center of gravity position G2 in the section perpendicular to the circumferential direction of the coil expander 20 is set to be smaller than the diameter D2 of the oil ring body 10 Is preferably less than 55% of the direction thickness dimension (t1).

With this configuration, the moment of inertia in the tilting direction of the oil ring 1 when the piston is tilted can be reduced, and the followability of the oil ring body 1 with respect to the cylinder inner surface can be further enhanced.

By reducing the radial distance D2 and bringing the center-of-gravity position G1 of the oil ring main body 10 and the center-of-gravity position G2 of the coil expander 20 close to each other, when the piston is tilted, 10 and the coil expander 20 can be reduced. Therefore, it is possible to make the coil expander 20 difficult to detach from the oil ring body 10, and at the same time, the mounting property of the coil expander 20 to the mounting groove 15 can be enhanced.

In this oil ring 1, the protruding thickness t3 of the lands 12a and 13a of the pair of rails 12 and 13 to the outside in the radial direction with respect to the web portion 11 is set to be larger than the thickness t3, 10 can be set to 40% or more of the thickness dimension t1 in the radial direction. For example, in the present embodiment, the thickness t3 is set to be 42.5% of the thickness dimension t1 in the radial direction of the oil ring main body 10.

By setting the protruding thickness t3 of the lands 12a and 13a in the radially outward direction with respect to the web portion 11 to 40% or more of the radial thickness dimension t1 of the oil ring main body 10 By setting the axial distance D1 to 70% or less of the axial width dimension w1 of the oil ring main body 10, the space between the upper rail part 12 and the lower rail part 13 Even if it is narrowed, the corresponding space can be enlarged by that much. Thus, the oil stay in the space between the upper rail portion 12 and the lower rail portion 13 can be reduced, and the oil consumption of the oil ring 1 can be further reduced.

3, in the oil ring 1, the opening height h toward the axial direction of the plurality of air holes 14 provided in the web portion 11 is set to be larger than the opening height h in the axial direction of the oil ring body 10 Can be set to 25% or less of the width dimension w1. For example, in the present embodiment, the opening height h of the air hole 14 is set to 21.5% of the axial width dimension w1 of the oil ring body 10. The opening width L of the air hole 14 toward the circumferential direction can be 20% or more with respect to the pitch P in the circumferential direction of the plurality of air holes 14. For example, in the present embodiment, the opening width L is set to about 31.4% with respect to the pitch P in the circumferential direction of the plurality of air holes 14.

With this configuration, since the oil discharge from the space between the upper rail portion 12 and the lower rail portion 13 by the air hole 14 can be enhanced, the axial distance D1 can be set to be Even if the space between the upper rail part 12 and the lower rail part 13 is narrowed by setting the axial width w1 of the oil ring main body 10 to 70% or less, (14). Thus, the oil stay in the space between the upper rail portion 12 and the lower rail portion 13 can be reduced, and the oil consumption of the oil ring 1 can be further reduced.

These through holes 14 may be formed by using laser processing or electron beam processing. The space between the upper rail 12 and the lower rail 13 is narrowed by setting the axial distance D1 to 70% or less of the axial width w1 of the oil ring body 10 A plurality of air holes 14 can be formed in the web portion 11 with high accuracy by laser processing or electron beam processing. Therefore, it is possible to set the axial distance D1 to be 70% or less of the axial width dimension w1 of the oil ring body 10 to improve the followability with respect to the cylinder inner surface of the oil ring body 10, The oil in the space between the upper rail 12 and the lower rail 13 can be effectively discharged from the through holes 14 to further reduce the oil consumption of the oil ring 1. [

Example

In the oil ring of the embodiment, the axial distance between the axially outer edge of the outer peripheral surface of the upper rail and the outer peripheral edge of the lower rail is 1.32 mm, The thickness dimension in the radial direction of the oil ring body was set to be 2.00 mm, the thickness dimension in the radial direction of the web portion was set to 0.40 mm, the thickness of the land was set to 0.85 mm, the circumferential direction of the oil ring body The radial distance from the radial center-of-gravity position in the cross section perpendicular to the circumferential direction of the coil expander to the radial direction center-of-gravity position in the cross section perpendicular to the circumferential direction of the coil expander was 1.04 mm. In this case, the axial distance between the axially outer rim of the outer peripheral surface of the upper rail and the axially outer rim of the outer peripheral surface of the lower rail is 66% of the axial width dimension of the oil ring main body, The width dimension in the axial direction of the oil ring body is 8% of the axial width dimension of the oil ring body, the thickness dimension in the radial direction of the web portion is 20% of the thickness dimension in the radial direction of the oil ring body, Diameter radial distance from the radial direction center-of-gravity position of the end face of the coil expander to the radial direction center-of-gravity position of the cross-section perpendicular to the circumferential direction of the coil expander is 52% of the radial thickness dimension of the oil ring body.

In this embodiment, the opening height of the air hole provided in the web portion is 0.43 mm, the opening width is 1.10 mm, and the pitch between the plurality of air holes is 3.50 mm.

Further, in the present embodiment, the inner side surfaces, that is, the outer peripheral surfaces and the side surfaces, in which the air holes of the web are opened, are mutually inclined at an angle of 10 degrees with respect to the radial direction, And the outer circumferential surface of the web are continuous, an R having a radius of 0.10 mm is attached. On the other hand, the outer side surfaces of the rail portions facing each other are inclined at an angle of 18 degrees with respect to the radial direction.

Next, as a comparative example of this embodiment, it is assumed that the axial distance between the axially outer rim of the outer peripheral surface of the upper rail and the axially outer rim of the outer peripheral surface of the lower rail is 70% Or more. In the oil ring of this comparative example, the axial width of the oil ring body was 2.00 mm, the axial distance between the axially outer rim of the outer peripheral surface of the upper rail and the axially outer rim of the outer peripheral surface of the lower rail was 1.74 mm, The radial thickness dimension of the oil ring body is 0.55 mm, the thickness dimension of the web section is 0.55 mm, the land thickness is 0.70 mm, the circumferential direction of the oil ring body in its circumferential direction The radial distance from the radial gravity center position in the cross section perpendicular to the circumferential direction of the coil expander to the radial gravity center position in the cross section perpendicular to the circumferential direction of the coil expander is 1.10 mm. In this case, the axial distance between the axially outer rim of the outer peripheral surface of the upper rail and the axially outer rim of the outer peripheral surface of the lower rail is 87% of the axial width of the oil ring main body, The width dimension in the axial direction of the oil ring body is 11% of the axial width dimension of the oil ring body, the thickness dimension in the radial direction of the web portion is 27.5% of the thickness dimension in the radial direction of the oil ring body, The radial distance from the radial direction center-of-gravity position in the end face to the radial direction center-of-gravity position in the section perpendicular to the circumferential direction of the coil expander is 55% of the radial thickness dimension of the oil ring body.

In this comparative example, the opening height of the air hole provided in the web portion is 0.50 mm, the opening width is 1.50 mm, and the pitch between the plurality of air holes is 10.00 mm.

Further, in this comparative example, the inner side surfaces, that is, the outer peripheral surfaces and the side surfaces, in which the outer peripheral surfaces of the webs have the air holes, are inclined at an angle of 10 degrees with respect to the radial direction, And the outer circumferential surface of the web are continuous, an R having a radius of 0.15 mm is attached. On the other hand, the outer side faces of the rail portions opposite to each other are inclined at an angle of 20 degrees with respect to the radial direction.

Either of the oiling rings of Examples and Comparative Examples was mounted on a piston of a diesel engine and used as a steel material. In the examples and the comparative examples, the same coil expander having a coil diameter of 1.6 mm was used, and the elastic force of the coil was adjusted so that the same surface pressure was generated.

The oil ring of the embodiment and the oil ring of the comparative example were each mounted on a piston of a diesel engine and the oil consumption when the diesel engine was operated at a predetermined number of revolutions and load was measured and the results were compared. As a result of the comparison, it was found that the oil consumption of the oil ring of the example was reduced by about 15% as compared with the oil ring of the comparative example.

Thus, in the oil ring of the embodiment, even in the case of the oil ring in which the axial width dimension of the oil ring body is thinly formed to 2.00 mm, the axial outer- Of the oil ring body 10 is set to be 70% or less of the axial width dimension of the oil ring body so that the followability of the oil ring body 10 with respect to the cylinder inner surface can be improved and the oil consumption amount thereof can be reduced.

Further, in the oil ring of the embodiment, in the oil ring in which the width dimension in the axial direction of the oil ring body is thinner than 2.00 mm, the axial outer edge of the outer peripheral surface of the upper rail and the outer peripheral edge of the lower rail Even when the axial distance between the upper rail and the lower rail is set to 70% or less of the axial width dimension of the oil ring main body, the oil stay in the space between the upper rail and the lower rail is suppressed, , It was found that the oil consumption amount can be reduced.

It is needless to say that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, the oil ring of the present invention is mounted on the piston of the diesel engine. However, the present invention is not limited thereto and may be applied to the oil ring mounted on the piston of the gasoline engine.

Although the outer peripheral surfaces 12b and 13b of each of the rails 12 and 13 are formed as flat surfaces perpendicular to the axial direction in the above-described embodiment, the outer peripheral surfaces 12b and 13b are not limited to the axial direction and the radial direction It can be formed into an inclined surface inclined with respect to both directions or a curved surface curved into a convex shape or a concave shape. In this case, the axially outer rims of the outer circumferential surfaces 12b and 13b become the outermost portions in the axial direction among the portions in contact with the inner surface of the cylinder in accordance with the tilting of the pistons of the outer circumferential surfaces 12b and 13b.

Further, the material of the oil ring main body 10 is not limited to the steel material but may be made of other materials. Further, the outer circumferential surfaces 12b, 13b of the rail portions 12, 13 of the oil ring body 10 Various surface treatments can be performed on the surface.

1 oil ring
10 Oil ring body
10a and 10b,
11 web portion
12 Lower part
12a land
12b outer peripheral surface
13 Lower part
13a land
13b outer peripheral surface
14 through hole
15 Mounting groove
20 coil expander
w1, w2 Axial width dimension
D1 Axial distance
D2 Distance in the radial direction
t1, t2, t3 Diameter Thickness Dimensions
h opening height
L opening width
P pitch

Claims (6)

An oil ring body formed in a toric shape having a web portion provided with a through hole and a pair of rail portions integrally provided on both sides in the axial direction of the web portion and having a mating hole; An oil ring having a coil expander that presses the oil ring body toward the radially outer side,
An axial distance between an axially outer rim of the outer peripheral surface of the one of the rails facing the radially outer side and an axially outer rim of the outer peripheral surface of the other of the rails facing the radially outer side, Of the direction width dimension is 70% or less of the direction width dimension. The method according to claim 1,
Wherein an axial width dimension of an outer peripheral surface of each of the pair of rails is in a range of 5.0% to 10.0% of an axial width dimension of the oil ring body. 3. The method according to claim 1 or 2,
Wherein the thickness dimension in the radial direction of the web portion is 25% or less of the thickness dimension in the radial direction of the oil ring body. The method according to claim 1,
Wherein a radial distance from a radial direction center-of-gravity position on a cross-section perpendicular to the circumferential direction of the oil ring main body to a radial direction center-of-gravity position on a cross section perpendicular to the circumferential direction of the coil expander, And less than 55% of the radial thickness dimension of the body. 3. The method of claim 2,
Wherein a radial distance from a radial direction center-of-gravity position on a cross-section perpendicular to the circumferential direction of the oil ring main body to a radial direction center-of-gravity position on a cross section perpendicular to the circumferential direction of the coil expander, And less than 55% of the radial thickness dimension of the body. The method of claim 3,
Wherein a radial distance from a radial direction center-of-gravity position on a cross-section perpendicular to the circumferential direction of the oil ring main body to a radial direction center-of-gravity position on a cross section perpendicular to the circumferential direction of the coil expander, And less than 55% of the radial thickness dimension of the body.

Images