JPS60188660A - Piston ring - Google Patents

Abstract

PURPOSE:To prevent abnormal abrasion such as scuffing caused by sliding of a compound layer by removing a compound layer which is the upper layer portion of a nitriding layer and then plating or flame spraying a diffusion layer which is the lower layer portion thereof. CONSTITUTION:A nitriding layer 2 is disposed on the whole surface of a piston ring 1. As a compound layer 21 which is the upper layer portion of the nitriding layer 2 on the outer surface 11 of the piston ring 1 is not suitable for plating and flame spraying and not required, the compound layer is removed by polishing or the like, and then plating or flame spraying layer 3 is disposed on a diffusion layer 22 which is the lower layer portion of the compound layer 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piston ring for internal combustion engines, and particularly to a piston ring for internal combustion engines that use high lead fuel or have a corrosive atmosphere.

In recent years, lead-free fuel has been promoted due to pollution problems, but high-lead fuel is still widely used mainly in other countries. In internal combustion engines that use high-lead fuel, the corrosive atmosphere such as 1-IOA is strong, so the chrome plating on the sliding surfaces that are commonly used is subject to significant wear.

Therefore, as a countermeasure against high lead fuel, thick chromium plating has been implemented on sliding surfaces, but the effects are not sufficient in terms of cost and productivity.

In response to this, a method has been developed in which the sliding member is subjected to nitriding treatment, but this may cause abnormal wear such as scuffing depending on the engine.

The present invention has been developed with these points in mind, eliminating the drawbacks and making the most of the advantages.

That is, the entire surface of the cast iron or piston ring is nitrided, and the compound layer is removed from the nitrided layer on the outer peripheral surface to expose the diffusion layer, and then plating or thermal spraying is applied on the diffusion pattern. This is a piston ring with a special feature.

The present invention will be described below with reference to the accompanying drawings.

As shown in Fig. 1, a nitride layer 2 is formed on the entire surface of the piston ring 1.
Further, the compound layer 21 which is the upper layer of the nitride layer 2 on the outer circumferential surface 11 of the piston ring 1 is not needed because it does not adhere well to plating or thermal spraying, so after removing this compound layer by till polishing etc. A plating or melting layer 3 is provided on the diffusion layer 22 which is the upper layer of the compound layer 21.

Figure 12 shows that after removing the entire nitride layer from the outer peripheral surface 11,
A plating or thermal spray layer 3 is provided.

The plating may be chromium plating, dispersion plating, etc., depending on the compatibility with the engine, and the melting method may be the same (iron-based, molybdenum, etc.).

As described above, the compound layer which is the upper layer of the nitride layer is removed.1. : After that, by plating or thermal spraying on the diffusion layer which is the lower layer part, 1! of the compound layer is applied. ! This prevents abnormal wear such as scuffing during the 8th shift, and by plating or thermal spraying on the base material after removing the diffusion layer, the hard layer can last longer than when a thin diffusion layer is simply slid. Worth the time. In addition, the nitride layer on the top surface can be plated or thermal sprayed on the diffusion layer, or plated directly on the ring sliding movement.
When thermal spraying is applied, it prevents the upper and lower surfaces from being hit and worn, and also improves the wear resistance of the sliding surfaces due to the mating effect.

[Brief explanation of the drawing]

FIG. 1 is a J-sectional view showing one embodiment of the present invention;
The figure is a sectional view showing another embodiment of the present invention. Description of symbols 1...Piston ring 11...Same outer peripheral surface 2...Nitrided layer 21...Compound layer, 22...Diffusion layer 3...Plating or thermal spraying layer Patent applicant Japan Piston Ring Co., Ltd.

Claims (2)

[Claims] (1) Nitriding the entire surface of the iron or lil piston ring, and then removing the compound layer from the nitriding layer on the outer peripheral surface to expose the diffusion layer, and then plating or thermal spraying on the diffusion layer. A piston ring that is characterized by (2) In the piston ring, the base material is exposed by removing even the diffusion layer from the outer peripheral surface, and plating or thermal spraying is performed on the base material! 2. The piston ring according to claim 1, characterized in that: