JPH0542827U - Wire rod for piston ring - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the wear resistance and the friction resistance to improve the performance of the piston ring. [Structure] At least one side surface of a wire having an irregular cross section is made rough with a large number of dimples or pear skin.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a piston ring wire used in a piston ring for an internal combustion engine.

[0002]

[Prior Art]

 Conventionally, piston rings have been mainly surface-treated with hard chrome plating to improve wear resistance. However, in recent years, as the engine output has increased, the rotation speed has increased, and the fuel consumption has been reduced, it has become difficult to use conventional piston rings plated with hard chrome, and higher performance piston rings are required. Therefore, some engines use nitriding or composite plating piston rings. Further, in order to reduce the frictional resistance with the cylinder, a piston ring having a coating layer excellent in self-lubricating property has been tried.

[0003]

[Problems to be solved by the device]

 However, the former piston ring that has been subjected to nitriding treatment or composite plating is superior in wear resistance compared to the conventional hard chrome plated piston ring, but because the friction resistance with the cylinder is still large, Fuel consumption is decreasing. Further, the latter piston ring having a coating layer has a problem of peeling of the coating layer.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a piston ring wire rod which is a piston ring having excellent wear resistance and low frictional resistance.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the wire rod for a piston ring of the present invention has a wire rod having an irregular cross section with at least one side surface roughened.

The rough surface is composed of a large number of dimples having a diameter of 2 to 100 μm and a depth of 5 to 30 μm, or is composed of a pear skin having a surface roughness of Rz 5 to 30 μm, and is formed on one roughened side surface. Allow a moderately thick oil film to form.

[0007]

[Action]

 When a piston ring is molded with the piston ring wire configured as described above, when one roughened side surface becomes a sliding surface with the cylinder wall, the lubricating oil supplied is between the rough surface and the cylinder wall. It forms a good oil film. Therefore, the friction resistance between the piston ring and the cylinder wall is reduced, and the wear resistance is also improved.

Further, when the rough surface is on the upper and lower side surfaces of the piston ring, an oil film is formed between the rough surface and the piston ring groove in which the piston ring is mounted in the same manner as above. Therefore, the frictional resistance between the piston ring upper and lower side surfaces and the piston ring groove is reduced, and the wear resistance is also improved.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

Example 1 In FIG. 1, reference numeral 1 denotes a piston ring wire, which is formed by subjecting a stainless steel (SUS420J 2) wire to required wire drawing, rolling, heat treatment, etc., and a thickness t = 1. ． It has a substantially rectangular cross section with a width of 3 mm and a width W of 2.9 mm. A large number of dimples 3 are formed on the side surface 2 of the piston ring wire 1 to make it rough. As shown in FIG. 2, the dimple 3 has a diameter A of 2 to 100 μm and a depth B of 5 to 30 μm. By the way, it is more preferable that the dimples 3 have a diameter A of 20 to 60 μm and a depth B of 8 to 20 μm, and are scattered at an occupancy rate of 10 to 50% of the surface area of the side surface 2. Is.

Example 2 In FIG. 3, 4 is a piston ring wire formed in the same manner as in Example 1 above, and the side surface 5 of this piston ring wire 4 has a pear skin 6 and is roughened. To do. As shown in FIG. 4, the side surface 5 having the above-mentioned pear skin 6 is formed to have a surface roughness Rz = 5 to 30 μm.

By the way, the wire rod 4 for the piston ring may be subjected to a rolling process thereafter, or a side face 5 may be subjected to a lapping process to form a flat portion 7 after the ring forming process to form a piston ring. ..

In the first and second embodiments, the piston ring wire rods 1 and 4 have a substantially rectangular cross-section, but they may have a special cross-sectional shape such as an L-shape or a U-shape. Although the ground surface 6 is provided on only one side surface, it may be provided on an appropriate side surface of the wire (for example, the upper and lower side surfaces or the entire peripheral surface).

By the way, the rough surface of the dimples and the pear skin can be formed by an appropriate means such as rolling with a roller having a large number of minute projections, liquid honing treatment, shot blasting, or the like. ..

[0015]

[Effect of the device]

 Since the present invention has the above-described configuration, when a piston ring is used, the recess on the rough surface serves as a reservoir for the lubricating oil, and an appropriately thick oil film is formed between the cylinders, which results in wear resistance. It also has the effects of improving the friction resistance with the cylinder, contributing to lower fuel consumption of the engine, and greatly improving the piston ring performance.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a first embodiment.

FIG. 2 is an enlarged cross-sectional view of a main part of FIG.

FIG. 3 is a partially cutaway perspective view of the second embodiment.

FIG. 4 is an enlarged cross-sectional view of a main part of FIG.

FIG. 5 is an enlarged cross-sectional view of an essential part showing a state in which Example 2 is subjected to rolling or lapping.

FIG. 6 is a perspective view of a piston ring using the first embodiment.

[Explanation of symbols]

 1, 4 Piston ring wire rod 2, 5 Side surface 3 Dimple 6 Rashiko skin 7 Flat part

Claims (3)

[Scope of utility model registration request] 1. A wire rod for a piston ring having a modified cross section, wherein at least one side surface is roughened. 2. The rough surface has a diameter of 2 to 100 μm and a depth of 5 to 3.
The piston rod wire rod according to claim 1, which is composed of a large number of 0 μm dimples. 3. The wire rod for a piston ring according to claim 1, wherein the roughened surface is a pear skin having a surface roughness Rz of 5 to 30 μm.