JPS5813252B2 - How to make a mold for cylinder head casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a method for manufacturing a mold for casting cylinder heads of automobile engines, and more particularly to a method for assembling cores in such a mold.

The structure of a conventional cylinder head casting mold is shown in Fig. 1, and the assembly order is that the core 3 for the lower side of the water jacket is first assembled into the lower mold 1, and then the mold for the intake and exhaust boats is assembled. After installing the core 2, it was common to place the core 4 for the upper side of the water jacket.

In this case, there are a plurality of cores 2 for the intake and exhaust boats, each of which is independent, and the weir core 5 may be used separately, so the number of cores to be combined is large, and the number of man-hours is also large. It was undeniable that it would become expensive and the work of assembling the core would become troublesome.

Furthermore, a large number of cores to be combined is undesirable because it increases the occurrence of cast burrs at the joints of the cores, leading to an increase in the number of finishing steps.

Therefore, in the present invention, a plurality of intake and exhaust boat cores are joined to a manifold mounting side baseboard and a main mold component located on the side opposite to this baseboard and forming a part of the main mold. An attempt was made to eliminate the above-mentioned problems by forming a core as one piece, combining this core with a water jacket core, and incorporating these cores into the main mold. be.

An example of actual winding of the method of the present invention will be explained below based on FIGS. 2 to 4.

The core 12 for the intake and exhaust ports is made by joining together a plurality of cores 2 shown in FIG. 1 at a baseboard portion 12a.

A core in which a plurality of cores 12 for the intake and exhaust boats are provided has a fitting part 12b, and is combined with a core 13 for the water jacket side using the fitting part 12b and glued, Next, the core 14 for the upper side of the water jacket is assembled and glued.

Note that this fitting portion 12b is provided at a portion corresponding to the cast hole H.

Further, it is preferable to fill the joint surfaces of the cores 13 and 14 with powder to prevent the occurrence of burrs during casting.

After these cores 12, 13, and 14 are assembled in this way, they are assembled into the lower mold 11 and covered with an upper mold (not shown) to form a mold.

According to this method, a plurality of intake and exhaust ports can be formed with one core 12, and it is also possible to replace a part of the weir core as shown in the figure 12d, and as a result, the number of cores to be combined is reduced. As a result, the number of man-hours is reduced, making the combination work easier.

Furthermore, a reduction in the number of cores inevitably leads to a reduction in the number of places where casting burrs occur, making finishing work easier.

As a result, the cost of the mold itself can be reduced.

When forming a core having a plurality of cores 12 for intake and exhaust ports, a lower mold 11 that forms a main mold together with an upper mold is used.
Since the part 12c as the main mold component forming a part of the manifold mounting side baseboard part 12c is also integrally provided on the side facing the manifold mounting side baseboard part 12c, positioning of the core when assembled into the lower mold 11 becomes easy. Since there is no misalignment with the lower mold 11 and the casting gap can be maintained accurately, the precision of casting can be improved and the assembly work becomes extremely easy.

The treatment of the cast hole H after casting is the same as in the conventional method, and it may be sealed with a blind plug, or used for connection to a water pump, etc.

As described above, the present invention reduces the number of cores to be combined when producing a cylinder head casting mold, and also reduces the number of assembly and finishing steps. The effect is extremely large.

Furthermore, positioning of the core in the main mold becomes extremely easy, and since no misalignment occurs between the main mold and the core, the casting gap becomes accurate and casting accuracy can be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view illustrating a conventional cylinder head casting mold, Figs. 2 to 4 show an example of the present invention, and Fig. 2 shows a combination of cores. FIG. 3 is a cross-sectional view of the mold corresponding to the section taken along line A-A' in FIG. 2, and FIG. 4 is a vertical cross-sectional view of the mold. 11...Lower mold, 12...Intake/exhaust port core, 1
2a...baseboard, 13.14...core for water jacket, H...cast hole.

Claims (1)

[Scope of Claims] 1. A mold for casting a cylinder head, which includes a manifold mounting side baseboard portion, a main mold component that exists on the side facing the baseboard portion and constitutes a part of the main mold, and a plurality of air intakes. , a core for an exhaust port, and a core integrally joined together, a core for a water jacket is combined with this core, and these cores are assembled into a main mold. A method for manufacturing a mold for head casting. 2. The manifold mounting side baseboard part, the main mold component part,
Claim No. 1, characterized in that a core in which a plurality of intake and exhaust cores are joined and integrated is combined with a water jacket core at a portion corresponding to a cast hole in the water jacket part. A method for manufacturing a cylinder head casting mold according to item 1.