JPS6195762A - Method for embedding by die casting chip material formed with thin-walled hard layer on surface - Google Patents

Abstract

PURPOSE:To absorb the clearance between a chip material and a die for casting and to prevent the crack of the chip material by interposing a thin-walled metallic material between a hard sintered alloy layer formed on the surface of the chip material and the contact surface of the die for dicasting and embedding the chip material by casting. CONSTITUTION:The thin-walled soft metallic layer 6 is inserted between the hard sintered alloy layer 4 on the surface of the chip material and the contact surface of the die 8 for die casting in the range of embedding, by casting, the chip material 2 formed thinly with the hard sintered alloy layer 4 on the surface of a ferrous base material 3 and therefore the layer 6 acts as a cushion material when a molten metal is poured under the pressure into the residual cavity 10 of the die 9 for die casting. The clearance between the layer 4 and the contact surface of the die 8 is thus absorbed and uniform external force is exerted to the layer 4, by which the generation of the crack to the material 2 from the alloy layer 4 on the surface thereof is prevented.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is an improvement in a method of casting and integrating a chip material formed by forming a thin layer of hard sintered alloy on the surface of an iron-based base material by die-casting. Regarding.

(Prior Art) Conventionally, for example, when casting a rocker arm made of helical alloy for an automobile engine, a thin layer of hard sintered alloy is deposited on the surface of a steel member, as shown in Japanese Utility Model Application Publication No. 56-34013. After the formed chip material with wear resistance is installed with its hard sintered alloy layer side in contact with the cavity surface of the die-casting mold, the metal is poured under pressure into the remaining cavity of the mold and cast-in integrally. The method of casting rocker arms by means of a method of casting is well known.

(Problem to be Solved by the Invention) However, in the above conventional method, when installing the chip material in the cavity of the die-casting mold, the chip material is set so as to be in contact with the cavity surface of the die-casting mold. A slight clearance will inevitably occur between the chip material and the chip material. Therefore, when AU molten metal is poured into the mold cavity by die-casting pressure, the chip material is located around 1 degree from the correct position due to the above-mentioned clearance, and the bending bamboo acts on the chip material, resulting in a hard but brittle structure. There was a problem in that the chip material cracked from a part of the hard sintered alloy layer.

Therefore, in order to prevent the chip material from cracking as described above, it is possible to set the die-casting pressure lower than the normal setting value (<1oookv/- or more), but then
There is a risk of problems such as poor circulation in the M container field, large cavities in the AQ body, and failure to produce products, so reducing the die-casting pressure to less than 1000J/- is an essential solution. It cannot be a means. Another possible countermeasure would be to increase the thickness of the chip material to increase its rigidity, but this would require a large amount of chip material to be used.
In addition to increasing costs, the weight of interlocking parts such as rocker arms increases, and this cannot be an essential solution.

The present invention 9 has been made in view of the above-mentioned points, and its purpose is to create a gap between the hard sintered alloy layer of the chip material and the abutting surface of the die-casting mold when the chip material is cast. By pouring the metal under pressure with a predetermined material interposed, the clearance between the hard sintered alloy layer and the cavity surface of the die-casting mold is absorbed, and the hard sintered alloy layer is filled with irregularities such as bending WJ weight. The purpose is to prevent uniform die-casting pressure from acting and reliably prevent the occurrence of cracks in the chip material.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention provides lii! ￥J A chip material made of a thin sintered alloy layer is installed with the hard sintered alloy layer side in contact with the cavity surface of a die-casting mold, and then the remaining cavity is poured under pressure and cast-in integrally. When molding, a thin soft metal material is interposed between the hard sintered alloy layer and the contact surface of the die-casting mold, and the bale is pressed and poured.

(Function) With the above configuration, in the present invention, when the chip material is cast-in, the thin soft metal material is interposed between the hard sintered alloy layer on the surface of the chip material and the contact surface of the die-casting mold. When molten metal is poured under pressure into the remaining capacity, the soft metal acts as a cushioning material, absorbing the clearance between the sintered alloy layer and the contact surface of the mold, and uniformly spreads over the hard sintered alloy layer. As a result, cracks are prevented from forming in the alloy layer on the surface of the chip material.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 3 shows a rocker arm 1 for an engine according to an embodiment of the present invention. The rocker arm 1 is made of die-cast Aρ alloy, and its tip, that is, the part that makes sliding contact with the cam of the engine camshaft, is made of a chip material. 2 are molded and integrated. The chip material 2 basically has a hard surface on the surface of the sliding contact portion of an iron base material 3 having a substantially T-shaped cross section and a surface of the sliding contact portion formed in an arc shape, that is, the surface that comes into sliding contact with the cam of the camshaft. It is formed by forming a thin sintered alloy layer 4.

To explain the method of forming the hard sintered alloy layer 4 on the surface of the iron base material 3, as shown in FIG. , their integral body in a non-oxidizing atmosphere at the liquid phase formation temperature (100
The hard sintered alloy layer 4 is formed on the surface of the iron-based base material 3 by heating the powder alloy sheet 5 to the iron-based base material 3 by heating to a temperature of 0 to 1150''C). The powder alloy sheet 5 contains, for example, 0.5 to 2.5% by weight of P.

A wear-resistant eutectic with a powder particle size of 150 mesh or less having a composition of 1.5 to 4.5% by weight of C, 2.5 to 5% by weight of Mo, 10% by weight of Cr, and the balance "e". Alloy powder 85
~97% by volume and 15~ acrylic resin dissolved in solvent
31ffi% and then rolled to a predetermined thickness. It has adhesion and bonding properties to the metal scrap base material under temperature conditions of 'C or higher.

When the chip material 2 is integrated into the tip part of the rocker arm 1 by die-casting according to the method of the present invention, first, CLI or N1 is applied to the surface of the hard sintered alloy layer 4 formed on the surface of the chip material 2. Soft metal Ii!
16 is joined. This soft base layer a 6 is bonded at the same time as the hard sintered alloy layer 4 is formed on the surface of the iron base material 3 using the powder alloy sheet 5, as shown in FIG.
This is carried out by adhering a foil 7 made of Cυ or N1 to the surface of the young tree alloy sheet 5 and subjecting it to heat treatment. In that case,
If the thickness of the foil 7 is less than 30μ, the cushioning effect against die-casting pressure will be reduced, while if it exceeds 90μ, it will be difficult to adhere to the powder alloy sheet 5, and the uniform soft metal layer 6 will not be resistant to sintering erosion. A thickness of 30 to 90 μm is preferable because the chip material 2 becomes too thick and cannot be set in the die casting mold 8.

Next, as shown in FIG. 1, the chip material 2 with the soft metal 8!16 formed on the surface of the hard sintered alloy layer 4 is placed in the cavity 10 formed in the split die casting mold 8.9. , the hard sintered alloy l! of chip material 2! ! The die casting mold 8 is installed with its 4 side in contact with the wall surface 11 of the cavity 10 of the die casting mold 8. That is, a soft metal material is interposed between the hard sintered alloy layer 4 of the chip material 2 and the contact surface thereof to the die casting mold 8. After that, the remaining cavities 1 of the molds 8 and 9
0, as shown by the arrow in the figure, by pouring 8 molten metal of A9 alloy under pressure and integrating the chip material 2 by casting, the third
A rocker arm 1 as shown in the figure is cast. The soft metal layer 6 formed on the surface of the chip material 2 is easily removed by polishing after the rocker arm 1 is cast.
The desired hard sintered alloy layer 4 can be exposed at the tip of the rocker arm 1.

In that case, since the soft metal layer 6 is bonded to the hard sintered alloy layer 4 on the surface of the chip material 2, the chip material 2 set in the cavity 10 of the die-casting mold 8.9 and the wall surface 11 of the cavity 10 Even if there is a clearance between them, the clearance is absorbed by the cushioning effect of the soft metal layer 6, and uneven die-casting pressure does not act on the hard sintered alloy layer 4 of the chip material 2. layer 4
This can prevent cracks from occurring in the chip material 2.

As a result, a normal chip material 2 without a crank is cast into the tip of the rocker arm 1 thus produced, and its quality can be improved.

In the above example, the soft metal WI6 was joined to the surface of the hard sintered alloy W44 by using a method of forming the hard sintered alloy Fa4 on the surface of the iron base material 3 using the powder alloy sheet 5. After adhering a thin soft metal material to the chip material abutting surface of the cavity 10 of the die-casting mold 8, the chip material 2 may be set in the cavity 10 of the molds 8 and 9 and pressurized pouring may be performed. Effects similar to those of the embodiment can be obtained.

Further, in the above embodiment, the rocker arm 1 made of a steel alloy for an engine was cast, but the present invention uses rB
Needless to say, the present invention can also be applied to the casting of various articles by integrally casting them in hot water.

(Effects of the Invention) As described above, according to the method of the present invention, a thin soft metal material is interposed between the hard sintered alloy layer on the surface of the chip material and the contact surface of the die casting mold, and the remaining part of the mold is Molten metal is poured under pressure into the capitivity, and the chip material is integrated by casting, so when pouring under pressure,
The clearance created between the chip material and the mold can be absorbed by the cushioning effect of the soft metal material, allowing the die-casting pressure to be applied uniformly to the chip material, preventing cracks from forming on the hard sintered alloy layer on the surface of the chip material. It is possible to reliably prevent this from occurring and improve the quality of the cast product.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a cross-sectional view showing a chip material set in the cavity of a die-casting mold, Fig. 2 is an enlarged front view of the chip material, and Fig. 3 is a die-casting mold. FIG. 3 is a partially cutaway front view of the rocker arm. 1... Rocker arm, 2... Chip material, 3...
Iron base material, 4... Hard sintered alloy layer, 6... Soft metal layer, 8°9... Die casting mold, 10... Cavity.

Claims (2)

[Claims] (1) After installing a chip material formed by forming a thin hard sintered alloy layer on the surface of an iron base material with the hard sintered alloy layer side in contact with the cavity surface of a die-casting mold, the remaining This is a method of pouring metal into a cavity under pressure and integrating the cast-in, in which a thin soft metal material is interposed between the hard sintered alloy layer and the contact surface of the die-casting mold, and then pouring under pressure. A method for die-casting a chip material with a thin hard layer formed on its surface. (2) Die-cast casting of a chip material with a thin hard layer formed on the surface according to claim (1), wherein the thin soft metal material is a soft metal layer bonded in advance to the surface of the hard sintered metal layer. Method.