JPH0645062B2 - Casting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is to install a heterogeneous or homogeneous piece preliminarily processed into a predetermined shape in a cavity for pouring, thereby integrally integrating the piece and the casting. The present invention relates to a method of casting a cast gurney to melt molten metal.

(Prior Art) As a conventional technology, there is one described in JP-A-56-39365.

That is, as shown in FIG. 4, a columnar cavity 2 for forming a cam shaft is formed in a mold 1, and a sprue 3 is communicated with one end (right end) of the cavity 2 to form the cavity 2
A plurality of cam pieces 4 are arranged apart from each other in the axial direction.

As shown in FIG. 5, the cam piece 4 is formed in an annular shape and an egg shape, and a thick fixing piece 5 is formed on the inner peripheral portion of the cam piece 4 so as to project in a tooth shape in the axial direction. Piece 5
Are projectingly arranged in a direction orthogonal to the molten metal flow path 2a of the cavity 2.

Then, there is a method of pouring molten metal into the cavity 2 from the sprue 3 to integrally join the cam piece 4 with the casting through the fixing piece 5 as shown in FIG.

(Problems to be Solved by the Invention) In the above-mentioned conventional one, the cam piece 4 installed in the cavity 2 is injected into the cavity 2 and the piece 4
Since it was only heated by the molten metal for molding remaining on the (fixed piece 5), the heating time for the piece 4 to be immersed in the molten metal having a high temperature was short, and the contact portion (a) between the piece 4 and the molten metal was smoothly fixed. There was a drawback that it was difficult to do.

It is an object of the present invention to obtain a new cast-in-turn casting method that solves the above drawbacks.

(Means for Solving Problems) The present invention is configured as follows to achieve the above object.

That is, a cavity that communicates with the gate and a preliminary chamber with a predetermined volume that communicates with the cavity are formed in the mold, and a piece having a predetermined shape is placed in the cavity located upstream of the preliminary chamber. It is configured such that the piece is heated by the molten metal that flows from the to the spare chamber through the cavity.

(Operation) Since the present invention is configured as described above, when pouring the molten metal from the sprue, the molten metal first passes through the cavity and flows into the auxiliary chamber, and while gradually flowing into the auxiliary chamber, the capacity of the cavity is gradually increased. It will fill from the downstream side toward the upstream gate.

In this case, since the piece is arranged in the molten metal flow path of the cavity, the piece comes into contact with the molten metal passing through the cavity.

Therefore, the piece is heated by new molten metal that is poured from the time when pouring is started from the spout to the time when the molten metal fills the preliminary chamber and reaches the piece, and is then surrounded by the molten metal. It will be.

(Example) Hereinafter, the Example of this invention is described based on drawing.

In the drawings, FIG. 1 is a cross-sectional view of a mold apparatus to which the present invention is applied, FIG. 2 is a cross-sectional view of a piece installed in its cavity, and FIG. 3 is a main part showing a welding state of the piece and a casting. It is an expanded sectional view.

In FIG. 1, reference numeral 10 denotes a mold for molding a camshaft for a multi-cylinder engine. Inside the mold 10, a camshaft-forming cavity 11 extending vertically and the camshaft 11 are vertically arranged in parallel. A preliminary chamber 15 that extends and communicates with the lower portion of the cavity 11 at the lower end is formed.

The cavity 11 has a large diameter and a plurality of cam piece fitting portions 12, a gear piece fitting portion 13, and a journal portion 14 which are vertically spaced apart from each other by a predetermined distance, and the cam piece fitting portion 12 and the gear piece fitting portion 12 are formed. A cam piece 16 and a gear piece 17 are fitted and locked on the shaft 13.

The cam piece 16 and the gear piece 17 are made of spheroidal graphite cast iron of the same material as the molten metal poured into the cavity 11, and as shown in FIG.
A thin and annular fixing piece 19 protruding in the axial direction is formed on a. This fixing piece 19 is, for example, a piece main body (16.1 having an outer diameter of about 60 mm and an inner diameter of about 40 mm).
It is formed on the inner peripheral wall of 7) with a thickness of about 0.2 to 1.5 mm and a width of about 5 mm in the axial direction. In this case, the thickness of the fixing piece 19 may be formed in a taper shape that gradually becomes thinner toward the axis.

In addition, the above-described mold 10 includes the cam piece fitting portions 12,
The gear piece fitting portion 13 and the upper surface of the journal portion 14 are split molds that can be divided in the vertical direction, and the upper part of the mold 10 has a sprue 11a communicating with the upper part of the cavity 11.
To form.

Then, each cam piece fitting portion 1 of the cavity 11
2. After fitting the cam piece 16 and the gear piece 17 to the gear piece fitting portion 13, the molten metal is poured from the sprue 11a.

According to the above-described embodiment, when the molten metal is poured from the sprue 11a, the molten metal first passes through the cavity 11 and the spare chamber 1
5, while flowing into the auxiliary chamber 15, the filling gradually increases from the downstream side of the cavity 11 toward the upstream sprue 11a.

In this case, since the fixing pieces 19 of the cam pieces 16 and the gear piece 17 are projected in the axial center portion of the cavity 11, that is, the molten metal flow path, the fixing pieces 19 are formed in the above-mentioned cavity 1.
It comes into contact with the hot melt passing through 1.

For this reason, the pieces 16 and 17 and the fixing pieces 19 are sufficiently heated by being immersed in the new molten metal poured from the sprue 11a for a long time, and as a result, as shown in FIG.
After the surface layer portion (a) is melted, it is surrounded by the new molten metal that has arrived at the fixing piece 19 portion.

The fixing piece 19 may be omitted in the present invention.

(Effects of the Invention) As is apparent from the above description, the present invention forms a preliminary chamber having a predetermined volume that communicates with the downstream end of the cavity, and uses a new molten metal that passes through when the preliminary chamber is introduced into the cavity. Since the piece installed in the above is heated, the piece is sufficiently heated by the molten metal for pouring, so that the piece and the casting surrounding the piece can be welded smoothly and firmly fixed to each other. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold apparatus to which the present invention is applied, FIG. 2 is a sectional view of a piece installed in its cavity, and FIG. 3 is an enlarged sectional view of an essential part showing a welding state between the piece and a casting. , FIG. 4 is a cross-sectional view of a mold device showing a conventional example, FIG. 5 is a cross-sectional view of a piece installed in the cavity, and FIG.
The figure is a cross-sectional view showing a welded state of a piece and a casting. 10: Mold, 11: Cavity, 11a: Gate, 1
2: cam piece fitting portion, 13: gap piece fitting portion, 1
4: journal section, 15: spare room, 16: cam piece,
17: gear piece, 18: main body, 18a: inner peripheral wall, 1
9: Fixed piece, (a): Surface layer part.

Claims (3)

[Claims] 1. A cavity for communicating with a sprue in a mold,
A preliminary chamber having a predetermined volume communicating with the cavity is formed,
A cast-in-fill casting method characterized in that a piece formed in advance in a predetermined shape is installed in a cavity located upstream of a preliminary chamber, and the piece is heated by a molten metal that flows from the spout to the preliminary chamber through a cavity. 2. The cast-in-girth casting method according to claim 1, wherein the piece has a plate-shaped fixing piece projectingly formed on a part of a peripheral wall of the piece toward the inside of the cavity. 3. The piece is annular and has a plate-shaped fixing piece extending in the circumferential direction on the inner peripheral wall of the piece so as to project inwardly. The cast-in-gully casting method described in the item.