JPH10306710A - Aluminum alloy tappet and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably reduce the cost for manufacture, by easily fixing a metallic cam receiving plate having the abrasion resistance, to an outer face of a top wall of a tappet body through an adhesion coating layer made of pure aluminum or nickel, with high bonding strength. SOLUTION: The fixing of the adhesion coating layer 3 to a cam receiving plate 2, is performed by the hot rolling, thermal spraying or the like, when pure aluminum is used, and is performed by the plating or the like when nickel is used. By using the adhesion coating layer 3, a cam receiving plate 2 and an upper face of a tappet body can be strongly fixed to each other when they are strongly kept into contact with each other. The bonding force of the metallic plate with aluminum alloy containing Si, is low, but that of the metallic plate with pure aluminum and nickel, and that of the aluminum alloy with the pure aluminum and nickel are high. Whereby the cam receiving plate 2 made of metal, and the tappet body 1 made of aluminum alloy can be strongly bonded in a condition that the adhesion coating layer 3 made of pure aluminum and nickel, acts as the strong binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy tappet used for a valve train of an internal combustion engine and a method of manufacturing the tappet.

[0002]

2. Description of the Related Art In a general aluminum alloy tappet used for a direct-acting valve train in an internal combustion engine,
A hard metal shim having wear resistance is detachably fitted into a recess formed in the outer surface of the top wall to prevent abrasion of the sliding contact surface with the cam. However, the use of the above-described shim is disadvantageous in terms of cost because parts management is troublesome and the engine assembly line is complicated.

[0003] Further, since the effective surface area of the outer surface of the top wall of the tappet in contact with the cam is reduced, if the lift amount of the engine valve is to be increased, the outer diameter of the tappet body is increased and a large diameter shim is required. It must be mounted, which limits the degree of freedom in engine design.

As a solution to such a problem, as shown in FIG. 6, a wear-resistant thin metal cam receiver is provided on the entire outer surface of a top wall of a tappet body (1) made of an aluminum alloy. There is a tappet to which the plate (2) is integrally fixed.

[0005]

The above-mentioned cam receiving plate (2)
Heating means such as welding or brazing is used to fix the material to the upper surface of the tappet body (1), but in order to combine materials having greatly different melting points, strict temperature control of both materials is required. Therefore, it is necessary to prevent the occurrence of variations in the bonding strength, which is troublesome and increases the manufacturing cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and greatly reduces the manufacturing cost by fixing the tappet body and the cam receiving plate, which are made of different materials, very easily and with a large bonding strength. It is an object of the present invention to provide an aluminum alloy tappet and a method for manufacturing the same.

[0007]

According to the aluminum alloy tappet of the present invention, the above-mentioned object is achieved by providing an outer surface of a top wall of a raised tappet body formed of an aluminum alloy,
The problem is solved by fixing a wear-resistant metal cam receiving plate via an adhesive film layer made of pure aluminum or nickel.

According to the tappet manufacturing method of the present invention, the above-mentioned problem is solved as follows. (1) A molding chamber is formed between the die in the press device and the punch inserted therein, the molding chamber forming a complementary shape with the top of the tappet body to be manufactured. After inserting a metal cam receiving plate having an adhesive film layer made of pure aluminum or nickel and a material made of an aluminum alloy in an overlapping manner so that the adhesive film layer faces the material side, the material is plastically deformed by punching Then, the top of the tappet body is formed, and the cam receiving plate is fixed to the outer surface of the top wall.

(2) A molding chamber is formed between the die in the press device and the punch inserted therein, the molding chamber forming a complementary shape with the main body of the tappet to be manufactured. A metal cam receiving plate is inserted through a bonding film layer made of aluminum or nickel with a material made of an aluminum alloy, which is previously fixed to the lower surface, and then the material is plastically deformed by a punch to form the cam receiving plate. The plate is secured to the outer surface of the top wall of the tappet body.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a tappet of the present invention, in which a cylindrical tappet body (1) whose upper surface is closed by a top wall (1a) is made of an aluminum alloy (for example, Al-Si).
System), on the outer surface (upper surface) of the top wall (1a),
As shown in FIG. 2 in an enlarged manner, a hard metal cam receiving plate (2) having a thin disk shape (for example, about 1.0 mm) having wear resistance is provided.
They are integrally connected via an adhesive film layer (3) made of pure aluminum or nickel fixed to the lower surface.
The adhesion of the adhesive film layer (3) to the cam receiving plate (2) can be performed by hot rolling or thermal spraying for pure aluminum, or by plating or the like for nickel.

[0011] The thickness of the adhesive film layer (3) depends on the cam receiving plate.
(2) is preferably a minimum thickness that does not directly contact the tappet body (1), and when made of pure aluminum, 5 to 40 μm,
When nickel plating is used, the thickness is preferably in the range of 1 to 4 μm.

When the above-mentioned adhesive coating layer (3) is interposed, when the cam receiving plate (2) is strongly pressed against the upper surface of the tappet body (1), they are firmly fixed to each other. That is, although the bonding strength between the metal plate and the aluminum alloy containing Si is generally small, the metal plate and pure aluminum and nickel,
Since the bonding force between the aluminum alloy and pure aluminum and nickel is large, the adhesive film layer (3) made of such pure aluminum or nickel becomes a strong binder,
The metal cam receiving plate (2) and the aluminum alloy tappet body (1) are firmly connected.

Next, the procedure for manufacturing the tappet will be described. As shown in FIG. 3, a disc-shaped adhesive film layer (3) made of pure aluminum or nickel is fixed on the bottom surface of a mold hole (4a) having a bottom in a die (4). Is inserted with the adhesive coating layer (3) side up. The inner diameter of the mold hole (4a) is substantially equal to the outer diameter of the tappet to be manufactured.

Next, a thick disk-shaped material (5) made of an aluminum alloy is placed on the upper surface of the cam receiving plate (2).

Next, a punch (upper die) (6) having a small diameter portion (6a) whose lower end portion is gradually tapered downward in a tapered shape.
Is lowered to a predetermined position, and the material (5) is cold forged. Then, as shown in FIG. 4, the material (5) is filled with the bottom of the die hole (4a) in the die (4), the lower end surface of the punch (6) and the concave portion (8) facing upward, and the die hole (4) in the die (4). It is plastically deformed in a forming chamber (7) formed between the inner surface of 4a) and the outer peripheral surface of the small diameter portion (6a) and complementary to the tappet body (1). The recess (8) is for forming a bulge (1b) at the center of the lower surface of the top wall (1a) of the tappet body (1), and forms a complement with the bulge (1b). I have.

When the material (5) is pressed, the material (5)
The lower face of the tappet is firmly adhered to the adhesive coating layer (3) on the upper face of the cam receiving plate (2) so that they are firmly fixed to each other, and the tappet is formed using the adhesive coating layer (3) as a binder. The main body (upside down) (1 ') and the cam receiving plate (2) are integrally connected.

Thus, a tappet similar to that shown in FIG. 1 is obtained. After molding, surface treatment such as finishing or heat treatment, or thermal spraying of the outer peripheral surface may be performed.

The present invention is not limited to the above embodiment. In the above-mentioned manufacturing procedure, the cam receiving plate (2) to which the adhesive coating layer (3) is fixed is separated from the material (5) by a die.
Although inserted in (4), a material (5) to which the cam receiving plate (2) is fixed in advance may be used. The material at this time is formed, for example, as follows.

That is, as shown in FIG. 5, a strip-shaped material (10) made of an aluminum alloy is placed on the upper surface of a strip-shaped steel sheet (9) to which an adhesive film layer (3) made of pure aluminum or nickel is fixed in advance. And place them on the upper and lower rollers (11) (1
The steel plate (9) and the belt-shaped material (10) are integrally bonded through the adhesive coating layer (3) by rolling the belt-shaped material (10) by pressing strongly by 1), and this is pressed by a press. A blank is punched into a material, which is inserted into a die (4). By doing so, the number of parts is reduced, so that the management is easy, and the punching operation by the press is completed only once, so that the number of press machines and man-hours are reduced.

[0020]

According to the present invention, a tappet body made of an aluminum alloy having a different melting point and a metal cam receiving plate can be easily and firmly connected without using a conventional heat welding means. .

According to the second aspect of the present invention, the cam receiving plate can be easily fixed at the same time as the tappet body is formed by pressing the aluminum alloy material.
Manufacturing costs can be reduced.

According to the method of the third aspect, the number of parts can be reduced, and the number of steps for forming the cam receiving plate and the material by stamping with a press can be reduced.

[Brief description of the drawings]

FIG. 1 is a central longitudinal sectional front view of a tappet of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a longitudinal sectional view showing a state before forming a tappet in the method of the present invention.

FIG. 4 is a longitudinal sectional view showing a state after molding.

FIG. 5 is a vertical cross-sectional view showing a procedure for fixing a material and a cam receiving plate in advance by rolling.

FIG. 6 is a front view in the center longitudinal section showing a conventional tappet.

[Explanation of symbols]

 (1) (1 ') Tappet body (1a) Top wall (1b) Swelling part (2) Cam receiving plate (3) Adhesive coating layer (4) Die (4a) Mold hole (5) Material (6) Punch ( 6a) Small diameter part (7) Forming chamber (8) Recess (9) Steel plate (10) Strip material (11) Roller

Claims (3)

[Claims] 1. A wear-resistant metal cam receiving plate is fixed to an outer surface of a top wall of a tappet main body formed of an aluminum alloy via an adhesive coating layer made of pure aluminum or nickel. An aluminum alloy tappet, characterized in that: 2. A molding chamber is formed between a die in a press device and a punch inserted therein, the molding chamber forming a complementary shape to a tappet body to be manufactured, and one of the molding chambers is formed in the molding chamber. After inserting a metal cam receiving plate having an adhesive film layer made of pure aluminum or nickel on its surface and a material made of an aluminum alloy in such a manner that the adhesive film layer faces the material side, the material is punched. A method of manufacturing an aluminum alloy tappet, comprising forming a capped tappet body by plastic deformation and fixing the cam receiving plate to an outer surface of a top wall thereof. 3. A molding chamber is formed between a die in a press device and a punch inserted therein, the molding chamber forming a complementary shape with a tappet body to be manufactured. Pure aluminum is formed in the molding chamber. Alternatively, after inserting a material made of an aluminum alloy to which a metal cam receiving plate is fixed in advance on the lower surface via an adhesive film layer made of nickel, the material is plastically deformed by a punch, thereby forming the cam receiving plate. A tappet made of an aluminum alloy, wherein the tappet is fixed to an outer surface of a top wall of a tappet body.