JPH07314119A - Production of casting part having cast in material - Google Patents

Abstract

PURPOSE:To provide a production method of the casting part having a cast in material which is surely fixed. CONSTITUTION:A projecting part 2b of flange shape projecting from the outer circumferential surface of a cylindrical main body part 2a is integrally formed to a boss member 2 made of stainless steel to be cast in to the mounting part of an oxygen sensor 3, in pouring, the surface of projecting part 2b is not melted by the heat of molten metal. The projecting part 2b is formed to encircle the side surface of boss member 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing cast parts such as an exhaust manifold, a manifold case and an exhaust pipe mounted on an internal combustion engine of an automobile.

[0002]

2. Description of the Related Art For example, an exhaust manifold formed by casting is known to be mounted on an internal combustion engine of an automobile. This exhaust manifold includes, for example
As disclosed in Japanese Patent No. 62917, an oxygen sensor for detecting the oxygen concentration in the exhaust gas flowing through the exhaust passage may be provided. The oxygen sensor is detachably attached by being screwed into a screw hole formed at a predetermined position of the exhaust manifold.

[0003]

However, when the oxygen sensor is mounted on the exhaust manifold by the screwing method as described above, seizure occurs in the mounting contact portion of the oxygen sensor due to heat and corrosion caused by the high temperature exhaust gas. However, there is a problem that it becomes difficult to remove the oxygen sensor. Further, since the oxygen sensor mounting portion of the exhaust manifold body is usually formed to be thicker than other portions, the temperature gradient with other portions becomes large and thermal fatigue easily occurs. Therefore, the mounting portion is likely to be deformed or cracked, which causes gas leakage.

Therefore, in order to solve these problems, it is conceivable that a boss member for mounting a sensor, which is formed of a metal material having higher heat resistance and corrosion resistance than cast iron, is cast during casting of the exhaust manifold. However, in that case, there is a difference in material compatibility, melting point temperature, and the like between the metal forming the cast-in-stock material and the cast iron forming the exhaust manifold body,
It becomes difficult to securely fix the cast-in-mold material.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a cast part having a cast-in-circumference material capable of securely fixing the cast-in-gurgling material. It is a thing.

[0006]

DISCLOSURE OF THE INVENTION The present invention for solving the above-mentioned problems is directed to a method of manufacturing a cast part having a cast-in-place material in which a metal cast-in-place material is placed and poured into a mold. A flange-shaped protrusion is integrally provided on the side surface,
It is characterized in that the surface of the projecting portion is melted by the heat of the molten metal during pouring.

In a preferred aspect of the present invention, the protrusion is formed so as to surround the side surface of the cast-in-stock material.

[0008]

In the method of manufacturing a cast component according to the present invention, the cast-in-gurney material placed in the mold is heated by the contact with the poured molten metal. At this time, since the flange-shaped protrusion provided on the cast-in-stock material has a smaller heat capacity than that of the cast-in-stock material main body, it is heated rapidly at high temperature and its surface is melted. In particular, since the heat is less likely to escape to the cast-in-garment body main body toward the tip end side of the protruding portion, the tip end of the protruding portion is heated at the highest temperature and rapidly to melt the surface thereof. As a result, the melted portion on the surface of the protruding portion is fused with the molten metal, and the surface portion of the protruding portion is integrally joined to the solidified body of the molten metal as the fused portion is solidified by the subsequent cooling. If the protruding portion is formed so as to surround the side surface of the cast iron material, the portion integrally joined to the solidified body of the molten metal is formed so as to surround the periphery of the cast iron material, and the sealing property is improved. .

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of an exhaust manifold manufactured in this embodiment, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a boss member used as a cast-in member in this embodiment. 4 is a plan view of the boss member, and FIG. 5 is a sectional view taken along the line BB of FIG.

In this embodiment, the exhaust manifold 1 as shown in FIG. 1 and FIG. 2 is manufactured by casting, using the boss member 2 serving as the mounting portion of the oxygen sensor as a cast-in member. Inside the exhaust manifold, there are four exhaust passages 1a each having one end communicating with each cylinder discharge port of the four-cylinder internal combustion engine.
And a collective exhaust passage 1b formed by collecting the exhaust passages and communicating with an exhaust pipe (not shown) connected to the downstream side. The boss member 2 is provided near the outlet of the collective exhaust passage 1a.
Is cast around.

The boss member 2 is made of austenitic stainless steel (SUS304 (according to JIS G4303)) and, as shown in FIGS. 3 to 5, has a cylindrical main body 2a and an outer peripheral surface of the main body 2a. And a projecting portion 2b that projects and is formed in the shape of a thin ring plate. The boss member 2 is formed so that the outer peripheral surface of the main body portion 2a and the protruding portion 2b are in contact with each other and are cast. The main body 2
In a, a screw hole 2c for mounting the oxygen sensor 3 (see FIG. 2)
Are formed after the end of casting.

In order to manufacture this exhaust manifold, the boss member 2 is arranged at a predetermined position in the prepared mold and the molten metal is poured. At this time, the boss member 2 is heated by the contact of the poured molten metal, but the protrusion 2b is
Since the heat capacity is smaller than that of a, it is heated at a high temperature and rapidly to melt its surface. In particular, since heat is less likely to escape to the main body 2a toward the tip of the protrusion 2b, the tip of the protrusion 2b is heated at the highest temperature and rapidly, and the surface thereof is also melted more. As a result, the melted portion of the surface of the protrusion 2b is fused with the molten metal. When pouring is completed in this state and then left to cool, the fused portion and the molten metal solidify, and the boss member 2 is cast with the surface of the protruding portion 2b integrally joined to the solidified body of the molten metal. A circulated exhaust manifold 1 is formed.

Therefore, according to the method for manufacturing the exhaust manifold of the present embodiment, the boss member 2 used as the cast-in member.
Since the projecting portion 2b that is melted by the heat of the molten metal is provided in the boss member 2, the boss member 2 can be firmly fixed. Further, since the flange-shaped protrusion 2b projectingly provided on the outer peripheral surface of the main body 2a is formed over the entire circumference in the circumferential direction, an exhaust manifold that requires airtightness so that exhaust leakage does not occur. The sealing property is improved.

Further, in the exhaust manifold manufactured by the manufacturing method of the present embodiment, the boss member 2 serving as the mounting portion of the oxygen sensor 3 can be formed of a metal having excellent heat resistance and corrosion resistance. It is possible to prevent seizure from occurring in the mounting portion, and it is possible to easily remove and replace the oxygen sensor 3. Further, the possibility that the boss member 2 serving as the mounting portion of the oxygen sensor 3 is deformed or cracked is reduced.

Although the protruding portion 2b of the boss member 2 in this embodiment is formed in a flat shape, as shown in FIG. 6, the protruding portion 5b is formed in a wavy shape so that the protruding portion 5b is substantially formed. The length may be extended. Further, as shown in FIGS. 7 and 8, the protrusion 6b may be formed in a polygonal flange shape, or a plurality of the protrusions 6b may be provided.

Further, the protrusion 2b in this embodiment is
In consideration of the sealing property, it is formed on the outer peripheral surface of the main body portion 2a over the entire circumference in the circumferential direction. However, in the case of a cast component that does not require much sealing performance, a projecting portion is partially formed in the circumferential direction. You may. Although the above embodiment illustrates the case where the boss member 2 is cast around the exhaust manifold 1, for example, the cast stuff is cast around cast parts such as a maniverter case and an exhaust pipe which are parts for automobiles. In this case, the present invention can be applied.

[0017]

EFFECTS OF THE INVENTION According to the method for manufacturing a cast part having a cast-in member according to the present invention, a flange-shaped protrusion is integrally provided on the side surface of the cast-in member, and the surface of the protrusion is heated by the molten metal when pouring. Since it is made to melt by this, it is possible to securely fix the cast stuffed material. Further, by forming the projecting portion so as to surround the periphery of the side surface of the cast product, the sealing property can be improved.

[Brief description of drawings]

FIG. 1 is a front view of an exhaust manifold manufactured in an example.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a front view of a boss member used as a cast body material in Examples.

FIG. 4 is a plan view of a boss member used as a cast body material in Examples.

5 is a sectional view taken along the line BB of FIG.

FIG. 6 is a cross-sectional view of a boss member according to another embodiment.

FIG. 7 is a plan view of a boss member according to another embodiment.

FIG. 8 is a front view of a boss member according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Exhaust manifold 1a ... Exhaust passage 1b ... Collective exhaust passage 2 ... Boss member (casting material) 2a ... Main body 2b
… Projection 2c… Screw hole 3… Oxygen sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshi Miwa Aisin Takaoka Co., Ltd., Tenno No. 1, Takaoka Shinmachi, Toyota City, Aichi Prefecture

Claims (2)

[Claims] 1. A method for manufacturing a cast component having a cast-in-place material in which a metal cast-in-place material is placed and poured into a mold, wherein a flange-shaped protrusion is integrally provided on a side surface of the cast-in-die material. A method for manufacturing a cast component having a cast-in member, characterized in that the surface of the protrusion is melted by the heat of the molten metal during pouring. 2. The method for manufacturing a cast part having a cast-in material according to claim 1, wherein the protruding portion is formed so as to surround a side surface of the cast-in member.