JPH04103809A - Manufacture for tappet - Google Patents

Abstract

PURPOSE:To reduce a material cost and work expense by dividing a tappet into an upper half part for constituting a guide part and a lower half part connected to a bottom wall, and integrating the upper half part with the lower half part by welding from an inner side. CONSTITUTION:A tappet 1 consists of a cylindrical guide part 3 and a bottom wall 2, and is in a bottomed cylindrical shape. A ceramic chip is jointed on the bottom wall 2. A semi-spherical recessed part 8, is formed in the center of the inner side surface of the bottom wall 2 in order to receive the bottom end of a push rod 6. The tappet 1 is formed by dividing it into an upper half part 3a for constituting the guide part 3 and a lower half part 3b connected to the bottom wall 2, fitting the recessed part and the projecting part of both end surfaces, to each other and welding together the fitting parts of the upper half part 3a and the lower half part 3b from the push rod side 6, namely, from the inner side of the tappet 1. It is thus possible to provide the tappet 1 with the ceramic chip connected thereto at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a tabetsu F used in industrial aircraft covers, including internal combustion engines.

``Conventional Technology'' In recent years, air pollution in cities has been caused by exhaust gases from various fixed combustion devices such as factories, incinerators, heating appliances, and power plants, as well as from mobile sources such as automobiles and aircraft, which have increased rapidly in recent years.

In automobiles, which are one of the causes of these nine types of pollution, diesel engines have adopted EGR as required by exhaust gas regulations. As a result, tappets, which are sliding parts of internal combustion engines, are required to have wear resistance, and research is being carried out.

In view of this, the technique of brazing ceramic chips to the necessary parts of the metal parts of the tappet was developed in %K. 2-658.
It is disclosed as Publication No. 09. In this technology, the metal parts other than the ceramic are integrally constructed, and the hardness of the metal is t'HRc, which hardens at the same time as brazing.
46 or higher.

``Problem to be Solved by the Invention'' However, in Tabetsu F, the material whose adhesion does not dull due to heat treatment is a relatively expensive material among steel materials.

In addition, these materials do not have good workability, and especially when deep hole drilling is required, the processing time is long and the processing cost is high.

An object of the present invention is to provide a tappet with bonded ceramic chips at low cost.

"Section Mt - Means for Solving" Therefore, in order to solve the above problems, the present invention makes sliding contact with the bottom wall that contacts the cam and has the ceramic chip brazed thereon, and the guide hole of the V cylinder block. In a bottomed cylindrical tappet consisting of a guide part, the tappet is divided into an upper half that constitutes the guide part and a lower half that connects to the bottom wall, and the upper half and lower half are welded together from the inside of the tube. This is a tappet manufacturing method.

As the welding method, it is preferable to use electron beam welding or laser welding, which has a high degree of heat concentration.

Further, ceramics include all materials with excellent sliding properties such as silicon nitride, zirconia, alumina, carbide, and cermet.

Methods for brazing include methods of metamorphizing the surface of the wamic and then brazing with metal solder such as silver solder or aluminum solder, or directly joining metal with silver solder containing active metals such as titanium and zirconium. This is done using a known method.

Carbide and cermet can be bonded directly using a metal solder, or if necessary,
The residual stress of brazing due to tension difference is 1! Copper, nickel, etc. may be interposed to improve the balance.

It is desirable that the joint between the upper part and the lower half be a concave-convex fit.

``Function'' The function is that the metal part of the tappet is divided into an upper half and a lower half, and a ceramic chip is joined to the lower half by brazing. It is sufficient to use only the lower half of the metallic material gold, which can reduce the cost of the material.

In terms of workability, by dividing the metal part into upper and lower parts, the depth of the lower cylindrical part can be made shallower, making it relatively easy to work with materials that are difficult to work with. It's easy. On the other hand, the lower half is very easy to process because it has a simple pipe shape or a similar shape. Therefore, overall processing costs can be reduced.

Furthermore, if the hardness of the contact surface (back surface of the bottom wall) with the lower half of the deck V-rod is insufficient, at least that contact surface can be partially hardened by electron beam hardening, laser hardening, etc., if necessary. By doing so, the requirements for wear resistance can be satisfied.

Furthermore, by welding from the inside, there is no need to worry about excess S* forming on the guide portion that comes into sliding contact with the guide hole of the V cylinder block. If welding is performed from the outer periphery, the extra material must be machined, but this also helps reduce costs.

Furthermore, the concentricity and concentricity of the upper and lower halves can be increased by fitting the upper and lower halves together.

"Example" Embodiments of the present invention will be described below with reference to the drawings.

[Example 1] As shown in FIG. 1, the tube 1 has a cylindrical shape with a bottom and a cylindrical guide portion 3 and a bottom wall 2.

! El! A ceramic chip is bonded to 2.

A push rod 6 is provided at the center of the inner surface of the bottom wall 2.
A hemispherical recess 8 is formed to receive the lower end of.

Accordingly, the tabetsu obtained by the production method of the present invention)
1 is divided into an upper half part 8a constituting the guide part 8 and a lower half part 8b connected to the bottom wall, and the end faces are fitted with concavities and convexities, and the upper half part 8& and the lower half part 8b are connected to the rod 611. ．． The tab P is formed by welding the fitting part from the inside.

The metal material for the upper half is preferably JIS 840C, and the material for the lower half is JIS8NCM68G.
, JIS 5K024, etc. are preferable.

Ceramic chip 4Fi, 81sN4 content 90 weight-
A disc of pressureless sintered silicon nitride is processed by T-grinding and used. The surface of the ceramic nap 4 to be joined to the lower half portion 8b may be subjected to metafusing treatment in advance by a vapor deposition method.

Next, the manufacturing process will be explained.

First, the upper half part 8a and the lower half part 8b are made separately by cutting or the like. The upper half 8a has a total length of 45W1 and an outer diameter of φ
20 cm, and has a cylindrical shape with an inner diameter of 16 m. lower half 8
b is the outer diameter φ20■, the outer diameter φ of the fitting part with the upper half 8a
16m 111% fit length 1mm, jEI! It is 10m from the joint surface to the joint surface, and titanium,
Ceramic chip 4 with a thickness of 15 cm and an outer diameter of 20 mm, made of steel deposited by sputtering using the physical vapor deposition method.
The silver is soldered via solder.

The hardness of the lower half after brazing was HRC4G.

The thus-formed upper half 8at and lower half 8b were welded from the inside by electronic beam welding (not shown). Although the welding reinforcement 5 was about 0.8 - on the inner side, no excess was generated on the outer circumferential surface that slidably contacts the guide hole of the V cylinder lock.

The hardness of the lower half after welding was HRC40.

"Example 2" Example 10 The diameter of the bottom wall was made larger as it approached the bonding surface with the ceramic chip.

The diameter of the tube is also increased to match the diameter of the bottom wall, but other points are the same.

"Effects" Tappets manufactured using the manufacturing method of the present invention reduce material costs and processing fees, and by welding from the inside, excess material can be removed by processing compared to welding from the outside. No need (extremely useful in industry! This is a bet manufacturing method.

[Brief explanation of drawings]

FIG. 111 shows a first embodiment of the present invention. @Figure 2 is the second
This is an example. 1...φ tappet, 2...bottom wall, 8...guide part,
8a...Upper half, 8b...Lower half, 4...Ceramic chip, 5...S* section excess, 6...Deck V Erod, 7...Cam, 8...・Concavity Fig. 1 Fig. 2

Claims (2)

[Claims] (1) In a bottomed cylindrical tappet consisting of a bottom wall that contacts the cam and is brazed with a ceramic chip, and a guide section that slides into guide hole of the cylinder block, the upper half and bottom wall that make up the guide section A method for manufacturing a tappet in which the tappet is divided into a lower half that is connected to the tappet, and the upper and lower halves are welded from the inside to be integrated. (2) The tappet manufacturing method according to claim (1), wherein the welding means is electron beam welding or laser welding.