JPS58117310A - Tappet for engine - Google Patents

Abstract

PURPOSE:To eliminate the need for finish working after curing treatment while improving abrasion resistance by integrally forming a tappet proper by stainless steel and nitriding the surface by ions. CONSTITUTION:The tappet proper 1 is formed integrally by stainless steel, and the surface is ground and finished, and nitrided by ions at a comparatively low temperature. A material manufactured by adding a very small amount of one kind or several kinds of elements in vanadium, titanium, boron, tungsten, aluminum, nitorgen, etc. to stainless steel may be used as the material of the tappet proper 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tappet for an engine, which uses materials that are cheaper than conventional ones, has a higher surface hardness, and
It increases impact resistance, and also improves repeated fatigue strength and manufacturing efficiency.

Tappets for engines are required to have high surface hardness. Therefore, conventionally, this goal has been achieved by using heat-resistant steel and applying hard metal to the surface of the tappet body by thermal spraying or quenching, but after thermal spraying or quenching, the surface is modified again. In addition, since the thermal sprayed layer or the quench-hardened layer must be corrected, the thickness thereof becomes uneven, resulting in low reliability.

The present invention uses materials that are cheaper than conventional materials, and has the desired shape and shape.
By ion nitriding the surface of the tappet body, which is formed to the same size, its hardness is increased, eliminating the need for finishing after hardening treatment, improving product reliability and manufacturing efficiency. It is something that makes you In addition, the hardened layer is made thicker to improve performance such as wear resistance and peeling resistance. To explain this with respect to the embodiment shown in the drawings, (1) is the tappet body, which is composed of a rod portion (2) and a disk portion (3) with a trapezoidal cross section integrally formed at one end of the rod portion. , and its surface is nitrided by ion nitriding treatment to increase its hardness.

The entire tappet body (1) is integrally formed of stainless steel. It is also possible to use a material in which a small amount of one or more of elements such as vanadium, titanium, boron, tungsten, aluminum, and nitrogen is added to stainless steel.

As mentioned above, the tappet of the present invention is made of stainless steel, the surface of which is hardened by nitriding using the ion nitriding method, and the material of the main body (1), stainless steel, is easily nitrided. Contains chromium, which becomes extremely hard through nitriding and greatly improves wear resistance. Therefore, even on the surface of the tappet body (1) where there is a risk of wear due to friction with other parts, the wear due to the friction can be minimized, and a tappet that can be used for a long period of time can be provided. The nitriding of the main body (1) is carried out by reacting nitrogen with the surface of the tappet main body (1), which is integrally formed with the above-mentioned nitriding material, and allowing it to penetrate into the surface of the main body (1). As a result, the surface of the main body (1) itself is hardened, so there is no fear that the surface layer of the area subject to friction will peel off due to friction, unlike when thermal spraying is applied. In addition, the ion nitriding method is carried out by heating the main body (1), but since the processing temperature is relatively low, the nitriding process does not cause strain or coarsening of crystal grains in the main body (1). Therefore, if the surface of the tappet body (1) is polished and finished and then ion nitrided, there will be no need for correction after nitriding, which will reduce the labor involved in finishing and improve manufacturing efficiency. It is possible to provide a highly reliable tappet that can be made into 4 densities, and the thickness of the hardened layer after nitriding does not become thinner.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, with FIG. 1 being a front view and FIG. 2 being a plan view. (1): Tappet body, (2): Salary section, (3) - Disk section agent Patent attorney Tadayoshi Fujiwara Figure 7 Figure 2

Claims (1)

[Claims] (1) In an engine tappet having a disk portion with a trapezoidal cross section at one end of the rod portion, the entire tappet body is integrally formed of stainless steel, and the surface thereof is nitrided by ion nitriding method. (2) Claim 1 in which the entire tappet body is integrally formed of stainless steel containing trace amounts of one or more of vanadium, titanium, boron, tungsten, aluminum, and nitrogen.
tappets for engines.