JPH08309481A - Method for assembling mold of cylinder block of engine for vehicle - Google Patents

Abstract

PURPOSE: To provide a mold assembling method capable of setting a core with high precision when a mold is assembled. CONSTITUTION: A plurality of cores 3-6 arranged in a casting cavity by main molds 1, 2 which are split into an upper part and a lower part are directly set to the main molds 1, 2 and kept respective, the respective cores 3-6 are positioned with reference to the main molds 1, 2, the expansion of the positioning error between the cores due to the accumulated setting errors is suppressed, and the variance of the wall thickness of a cast cylinder block is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting method suitable for casting a cylinder block of a vehicle engine, and more particularly,
The present invention relates to a mold assembling method capable of increasing upsetting accuracy during mold assembling.

[0002]

2. Description of the Related Art As a casting device for a cylinder block of a vehicle engine, as shown in FIGS. 3 and 4, for example, a main mold 1 divided into upper and lower parts to mold the outer surface of the cylinder block of the vehicle engine. 2, a main core 3, a head surface core 4, a water jacket core 5, a water gallery core 6 and the like are arranged inside the casting space formed by 2, and the inner surface of the cylinder block is formed by these cores, There are those that are designed to mold water jackets and water galleries.

By the way, when a cylinder block is cast using the main molds 1 and 2 and the plurality of cores 3 to 6, the cores 3 to 6 are positioned and held with respect to the main molds 1 and 2. There is a need. For this reason, conventionally, as shown in FIG. 3, the skirting board portion 3a of the main core 3 is installed in the main molds 1 and 2 via the head surface core 4, or as shown in FIG. The water gallery core 5 is positioned by fitting the skirting part 5a of the water jacket core 5 to the water gallery core 6 installed in the main mold 2 on the side.

However, when the main core 3 and the water gallery core 5 are indirectly set up in the main molds 1 and 2 as described above, the space between the main molds 1 and 2 and the head face core 4 is increased. The upsetting error and the upsetting error between the head surface core 4 and the main core 3 affect the positioning accuracy of the main core 3, and the upsetting between the main cores 1 and 2 and the water gallery core 6 is performed. The error and the upsetting error between the water jacket core 5 and the water gallery core 6 are caused by the water jacket core 5
Will affect the positioning accuracy of. Therefore, even when the errors of the main molds 1 and 2 and the respective cores 3 to 6 are made as small as possible, it is extremely difficult to avoid a decrease in the positioning accuracy of the main core 3 and the water jacket core 5. As a result, the accuracy of core upsetting at the time of mold assembly is reduced.

When the core upsetting accuracy is lowered as described above, the variation in wall thickness of the cast cylinder block becomes large. Therefore, in the conventional art, a cylinder block having a thicker wall thickness than necessary is taken into consideration in consideration of the variation. It was necessary to design, and there was a limit to reducing the thickness of the cylinder block to reduce the weight of the vehicle engine.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a mold assembling method that allows a core to be set up with high accuracy during mold assembling. The challenge is to reduce the variation in wall thickness and contribute to weight reduction of vehicle engines.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is designed such that a plurality of cores arranged in a casting space of a vertically divided main mold are directly upset and held in the main mold. It is characterized by that.

[0008]

In the method of assembling the cylinder block mold configured as described above, since the respective cores disposed inside the main mold are directly installed in the main mold, each core is based on the main mold. Be positioned as. Therefore, the expansion of the positioning error between the cores due to the accumulation of the upsetting error as in the conventional case is suppressed, and the positioning accuracy of the core is improved. For this reason, variations in the thickness of the cast cylinder block are reduced, and the cylinder block can be made thinner and lighter, and the vehicle engine can be made lighter.

[0009]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing a concrete example of a mold assembled by the method according to the present invention, and FIG. 2 is a sectional view of another portion. In these figures, parts having the same functions as those of the conventional example shown in FIGS. 3 and 4 are designated by the same reference numerals.

In these figures, a main mold for molding the outer surface of a cylinder block of a vehicle engine is divided into upper and lower parts. Further, the main core 3, the head surface core 4, the water jacket core 5, and the water gallery core 6
By arranging the above in a casting space formed by the main molds 1 and 2, a cylinder block provided with a water jacket and a water gallery can be molded.

Here, in the present invention, as shown in FIG. 1, the skirting board portion 3a of the main core 3 is directly installed in the main molds 1 and 2 by penetrating the head face core 4 and as shown in FIG. As shown, the skirting board portion 5a of the water jacket core 5 is directly installed in the lower main mold 2 with the water gallery core 6 being penetrated. The head surface core 4 and the water gallery core 6 are directly installed in the main molds 1 and 2 as in the conventional case.

That is, since the cores 3 to 6 arranged in the casting space formed by the main molds 1 and 2 are directly installed in the main molds 1 and 2, respectively, the cores 3 to 6 are The main molds 1 and 2 are positioned relative to each other. Therefore, the main mold 1,
In addition to the upsetting accuracy of the cores 3 to 6 with respect to 2, the expansion of the positioning error due to the accumulation of upsetting errors is suppressed between the respective cores 3 to 6, and the positioning accuracy of the cores 3 to 6 is improved. Get higher

For this reason, the variation in wall thickness of the cast cylinder block becomes small, and it is not necessary to make the cylinder block thicker than necessary in consideration of the variation in wall thickness. The weight can be reduced and the vehicle engine can be reduced in weight. By reducing the thickness of the cylinder block, heat transfer efficiency and stress strain are improved.

In the above embodiment, the main core 3, the head surface core 4, the water jacket core 5 and the water gallery core 6 are shown as typical examples of the core, but other cores are provided as required. Similarly, the child can be directly mounted on the main molds 1 and 2.

[0015]

As is apparent from the above description, according to the present invention, the cores arranged in the casting space of the main mold for molding the inner surface of the cylinder block are directly set up in the main mold. Since the positioning accuracy of each core is high, the variation in wall thickness of the cast cylinder block can be reduced and the cylinder block can be made thinner and lighter, and the vehicle engine can be made lighter. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a specific example of a mold assembled by the method according to the present invention.

FIG. 2 is a sectional view of a portion different from FIG. 1 showing a specific example of the mold similarly assembled by the method according to the present invention.

FIG. 3 is a sectional view of a conventional example.

FIG. 4 is a sectional view of a conventional example showing a portion different from that of FIG.

[Explanation of symbols]

 1 Upper main mold 2 Lower main mold 3 Main core 3a Baseboard part 4 Head face core 5 Water jacket core 5a Baseboard part 6 Water gallery core

Claims (1)

[Claims] 1. A main mold, which is divided into upper and lower parts, and a plurality of cores arranged in a casting space of the main molds. Each core is directly upset and held in the main mold. Cylinder block mold assembling method for vehicle engine.