JPS6047033B2 - Cylinder block and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder block for a water-cooled engine and a method for manufacturing the same.

In general, water-cooled engines used in automobile engines, etc., are provided with a water jacket 2 around the outer periphery of a cylinder 1 of the engine to form a passage for water, as shown in Fig. 1, and are cooled by a radiator 3. The engine is cooled by circulating the water between the outer periphery of the cylinder 1 of the engine and the radiator 3 using the water pump 4.

) By improving the cooling effect of this cooling water on the cylinder 1 and uniformly cooling the entire cylinder 1, it is possible to completely prevent the cylinder 1 from deforming due to heat and generating abnormal noises. In order to do this, it is necessary to form each cylinder 1 independently as shown in Fig. 1, and to provide a passage 5 through which cooling water flows between each cylinder 1. If the interval is increased and the passage 5 is enlarged, the cooling effect will be improved, but if the overall size of the engine is increased, such problems will arise, so it is preferable to make the passage 5 as narrow as possible. However, the cylinder cylinder 6 consisting of the cylinder 1 and water jacket 2 of the engine as described above is made of a main mold (usually
(referred to as a matrix) and a core 7 of a sand mold etc. as shown in Figure 2.
If only the sand mold core 7 made of shell sand or the like is used, it is necessary to provide a draft during core manufacturing, so a cooling passage is provided between each cylinder of the sand mold core 7. If the part 8 to form is made too thin,
Particularly, the upper part of the part 8 becomes very thin and there is a risk of deformation or breakage during casting, so the thickness T of this part 8 is set at 5 to 6 mm. I couldn't do less. For this reason, the width of the cooling passage formed between each cylinder of the cylinder block cast using the core 7 cannot be reduced to less than 5 to 6 mm, which limits the ability to reduce the size and weight of the engine. Ta. Therefore, the present invention provides a core for use in cylinder block casting, in which at least the outer circumferential surface of the upper end of the portion for forming the cooling passages between the cylinders has a U-shaped cross section that sandwiches the cooling passage portions, and further, The above-mentioned drawbacks are eliminated by fitting a reinforcing member having a core deformation prevention piece extending from the cooling passage portion to both side wall portions, thereby making it possible to form this portion thinner than before. The following is a description of the embodiments shown in the detailed description of the present invention.

3 and 4 are a plan view and a cross-sectional view taken along the line 1-1 showing a core used when casting a cylinder block according to the present invention. Cooling water passes between each cylinder of this core 10. A reinforcing member 12 formed by bending a metal plate-like member into a U-shaped cross section is fitted onto at least the upper end outer circumferential surface of the portion 11 for forming the cooling passage.
1, especially the strength of the upper part where the inner thickness is thinner due to the draft angle.

Of course, it goes without saying that the reinforcing member 12 may be fitted onto the outer peripheral surface of the lower end of the portion 11 in order to improve the strength of the lower portion. If the strength of the portion 11 forming the cooling passage of the core 10 is improved in this way, the inner thickness T of this portion can be increased from 2 to 37077! It can be formed as thin as possible. If a cylinder block is cast using the core 10, each cylinder 13 will be completely independent, and the cooling water formed between each cylinder 13 will be as shown in FIGS. 5 and 6. It is possible to obtain a cylinder block 15 in which the width of the cooling passage 14 passing therethrough is made as narrow as possible. In addition, Yanghe, who uses this core 10 to cast the cylinder block 15,
The reinforcing member 12 fitted into the upper or lower part of the portion 11 forming the cooling passage of the core 10 is inserted into the cylinder 13 during casting.
It is cast into the upper part of the outer wall surface of the cooling passage 14.
Since the reinforcing member 12 does not protrude inward, the cooling efficiency of the engine is not reduced by the reinforcing member 12.
7 and 8 show other embodiments of the reinforcing member 12 fitted to the upper or lower outer peripheral surface of the portion 11 for forming the cooling passage of the core 10. What is shown is a U-shaped support arm 16 fixed to the upper end of a reinforcing member 12 formed by bending a metal plate-like member into a U-shape. When fitting the part for forming the cooling passage, the bent portions 16a at both ends of the support arm 16 are brought into contact with the recesses 10a provided on the outer periphery of the core 10 as shown in FIG. This prevents the portion 11 of the core 10 for forming the cooling passage from being deformed due to the force generated from the inside to the outside of the core.

Further, in the case shown in FIG. 8, a plurality of tongue pieces 17 extending outward are formed on both sides of the reinforcing member 12, and the reinforcing member 12
When the tongue piece 17 is fitted into the cooling passage forming portion 11 of the core 10, the tongue piece 17 is brought into contact with the inner wall surface 10b of the core 10 as shown in FIG.
This prevents the portion 11 for forming the cooling passage of the core 10 from deforming due to the force generated from the outside toward the inside. Of course, by fixing the above-mentioned support arm to this, it is also possible to resist the forces generated from the inside to the outside, thereby preventing deformation due to forces in both directions. Also, as shown in FIG. 11, the core 1 of the tongue piece 17 of the reinforcing member 12
It is possible to prevent deformation of the portion 11 due to forces in both directions during casting. As explained above, the cylinder block of the present invention surrounds a plurality of independent cylinders, has a cooling passage between each cylinder with a narrow width dimension in the cylinder arrangement direction, and has a narrow width dimension in the cylinder arrangement direction. A metal reinforcing member having a U-shaped cross section is cast and embedded at the upper end or the lower end across the passageway, and is integrated with the reinforcing member and extends along the passageway to both side wall portions in a direction orthogonal to the cylinder arrangement direction. Since it is equipped with seven core deformation prevention pieces, it is possible to reduce the width of the cooling passage between each cylinder to about half compared to the conventional one, and the whole can be made smaller and lighter. , it is possible to maintain a uniform cooling effect as each cylinder is an independent type, and the reinforcing member and the core deformation prevention piece are cast and embedded flush with the wall surface forming the cooling water passage, so that the cooling water can be maintained evenly. It does not create resistance to the passage and has the effect of reinforcing the cylinder block in these parts.

Further, in the method for manufacturing a cylinder block of the present invention, a plurality of cylinder bores are arranged in a line at equal intervals, the whole is formed into a rectangular block shape with core sand, and a thin-walled cooling passage forming part is provided between each cylinder bore. , a metal reinforcing member having a U-shaped cross section fitted over the upper end or lower end of this part and spanning the part, and a metal reinforcing member integrated with the reinforcing member and extending along the passage forming part in a direction perpendicular to the arrangement direction of the cylinder bores. Since the core having core deformation prevention pieces extending to both side wall portions is placed in the mother mold and cast, the thickness of the core at the cooling passage forming portion between each cylinder bore can be reduced. is possible,
The entire cylinder block can be made smaller and lighter, and the thin wall section is equipped with a reinforcing member and a core deformation prevention piece, so it can be used during handling such as molding the core, incorporating it into the mother mold, etc. It is possible to prevent damage due to the pressure of the engine, it is possible to accurately form narrow cooling passages, and it is possible to provide a small and lightweight engine with good cooling efficiency. This method is not applied to the entire length of the thin wall part, but is applied locally only to the upper or lower end, which is prone to breakage.It requires only the minimum number of parts required, can be manufactured at low cost, and has the effect of not impeding heat transfer. be.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view showing a water-cooled engine, Fig. 2 is a drawing showing a conventional example of a core used when casting a cylinder block for a water-cooled engine, and Fig. 3 is a plan view of a core according to the present invention. 4 is a cross-sectional view taken along line I-1 in FIG. 3, FIG. 5 is a cross-sectional view showing a cylinder block cast using the core according to the present invention, FIG. 6 is a vertical cross-sectional view, and FIG. and the eighth
The figure is a perspective view showing the shape of the reinforcing member attached to the core according to the present invention, and FIGS. 9 to 11 are drawings showing how the reinforcing member shown in FIGS. 7 and 8 is attached to the core. There is. DESCRIPTION OF SYMBOLS 10... Core, 11... Part forming a cooling passage, 12... Reinforcement member, 13...
・Cylinder, 14...Cooling passage, 15...
Ulindaprotsk.

Claims (1)

[Scope of Claims] 1 A cooling passage surrounding a plurality of independent cylinders and having a narrow width dimension in the cylinder arrangement direction between each cylinder, with the passage at the upper end or lower end of each cooling passage. A metal reinforcing member having a U-shaped cross section is cast and buried across the core, and a core deformation preventing portion is integrated with the reinforcing member and extends along the passageway to both side wall portions in a direction orthogonal to the cylinder arrangement direction. A cylinder block characterized by comprising a piece. 2 A plurality of cylinder bores are arranged in a row at equal intervals, the whole is formed into a rectangular block shape with core sand, and there is a thin walled cooling passage forming part between each cylinder bore, and this part is attached to the upper or lower end of this part. A metal reinforcing member with a U-shaped cross section that is fitted over the reinforcing member, and a deformed core that is integrated with the reinforcing member and extends along the passage forming portion to both side wall portions in a direction perpendicular to the arrangement direction of the cylinder bores. 1. A method of manufacturing a cylinder block, comprising placing a core having a prevention piece in a master mold and casting.