JPS5888440A - Lightweight cylinder block with sheet metal part - Google Patents

Abstract

PURPOSE:To obtain a lighweight and inexpensive cylinder block by dividing the cylinder block into a steel plate part and an aluminium alloy part for providing cylinder liners and cooling water jackets on the steel plate part and connecting the aluminium alloy part under them to be fastened by bolts. CONSTITUTION:This cylinder block is constructed by dividing its main body into a steel plate part 5 and an aluminium alloy part 6 at the position of the half length of a cylinder bore part. In the steel plate part 5, cylinder liners 8 are arranged in a line at a number equivalent to the number of cylinders on an upper plate 7 of a box-shaped main body of the steel plate part 5, and welded to be fast fixed. Each cylinder liner 8 is constructed into a double structure in the upper half of its whole length and bolt holes 10 are bored on the upper face of the steel plate part 5 to use the inside of the double tube for a jacket 9 of cooling water. Meanwhile, the aluminium alloy part 6 is formed by arranging tubes 11 in a line in accordance with the number of cylinders for inserting the above-said liners 8. The steel plate part 5 and the aluminium alloy part 6 are combined into one body by fastening bolts 15 inserted through respective bolt holes 10 and 10 by bolts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piston engine cylinder block formed by combining a steel plate cylinder part and an aluminum alloy block part in order to achieve mass reduction.

BACKGROUND ART Conventionally, a cylinder block 1 has an integral structure made of iron casting, as shown in FIG.

For this reason, in the design process, requirements for strength and paper size are often determined by manufacturing constraints, leaving many areas that can be considered to be of excessive quality. For example, cylinder block 1
0 strength means that the safety factor is too high. The lip between the bores cannot be made thin, so the gap between the cylinders 20 must be made larger as shown in FIG. The width of the cooling water jacket 5 provided around the cylinder 2 is made larger, the screw holes 4 for assembly are further arranged on the outer periphery, and the block 1 is formed larger.

In recent years, due to the demand for mass production and weight reduction of complex shapes,
The trend is toward aluminum blocks. However, even with regard to aluminum blocks, emphasis is placed on the precision and strength of the jacket part, and even if the precision and strength of the lower skirt part become excessive in terms of strength, they have no choice but to match the upper part. Therefore, when looking at the sleeve, it is common knowledge that there are 4 to 5 parts for cast iron, but it is thicker than that, and if it is a wet structure, the different materials are likely to loosen due to the difference in thermal expansion, resulting in a decrease in performance. Despite the fact that steel liners can be made thinner, have a higher cooling ability, and are preferred by K, they are not commonly used because of the high cost required for distortion-sound polishing after quenching.

The present invention aims to improve the above drawbacks by dividing the cylinder block into a steel plate block and an aluminum alloy block.
The steel plate part has a cylinder liner and a cooling water jacket, and the aluminum alloy part has the necessary parts as a cast product constituting the lower part of the cylinder block, and both parts are assembled by bolting. It provides engine cylinder blocks.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 4, the main body is divided into a steel plate portion 5 and an aluminum alloy portion 6 at a position approximately % of the cylinder bore length. The steel plate part 5 is fixed to the upper plate 7 of the box-shaped main body by welding cylinder liners 8 arranged in series in a number corresponding to the number of cylinders. The cylinder liner 8 has a double structure in the upper half of its entire length, and the inside of the double cylinder is used as a jacket 9 for cooling water. Bolt holes 10 are bored in the upper surface of the steel plate part 5 so as to surround each cylinder liner 8. . Aluminum alloy cover 6 Welfare steel plate section 5
The cylindrical parts 11 into which the cylinder liners 8 are inserted are arranged in series according to the number of cylinders, and the intervals between them are made to match the intervals between the cylinder liners 80 of the steel plate part 5. Further, bolt holes 10' are formed in the upper surface of the aluminum alloy part 6 to match the bolt holes in the steel plate part 5.

When assembling the steel plate part 5 and the aluminum alloy part 6, each cylinder liner 8 is inserted into the cylindrical part 11, and the cylinder 14 is used as an intermediary between the steel plate part rib 12 and the aluminum alloy part lip 13 using the port 15. Tighten the bolts.

For watertightness, before tightening the bolts, make sure to use a resin with the same coefficient of thermal expansion as aluminum, such as EponJi28;
10Ω, heat-resistant curing agent (Ciba) HV998:10, high temperature heating 140'U casting agent of calcium carbonate CaCo123G is dripped onto the bottom. Alternatively, it may be fixed from the back side with a glass cloth laminated epoxy resin.

FIG. 5 is a view of the upper block viewed from below, and is characterized by the fact that the -cylinder interval C can be made extremely narrow. C value is 7±
It can be done in about 2■.゛For example, cylinder liner 2
If the intermediate rep is 2■ in ■, C=4■ will be achieved. The minimum distance between the cylinders in the block below is 2M, but the height of the cylinder liner is 5, and the explosive force is greater in the upper steel plate part and smaller in the lower aluminum part, so the strength is There's nothing to worry about from a practical standpoint.

FIG. 6 shows a typical cross-sectional view of the bore section. Here, the water jacket is limited to approximately % depth of the cylinder bore height. The entire surface of the cylinder liner 8 or the upper 60% thereof is hardened.

Hardening is considered to be expensive due to the generation of distortion and the need for a larger polishing method, so it has been abandoned, but it can be put to practical use by beam hardening the cutting surface of the tool using an appropriate method using a laser or electron beam. be made to become Also, on the cylinder liner 80 guide cylindrical surface 11, for example, a square screw-shaped lll11 is opened to communicate with the water jacket.
6 can be provided to prepare for shore friction heat caused by sliding of the piston in the lower half of the cylinder liner. In this case, even if the water waves are small, they will be sufficient in time. Circulation with the upper part may be a natural convection of heated and lightened water, which functions as a -1 for the cooling channel in which the upper part grows. In this way, the lower water jacket section is omitted, making it possible to create a compact and simplified cylinder block. The problem with the wet type method, which has a high separation due to its rigidity, is that the bearing hole in the lower block and the lower bore guide make it possible to perform centering in one piece, and using this as a guide. A cylinder liner is installed, and the steel plates are beam-welded to each other on the upper surface to be integrated and fixed to provide strength and rigidity, resulting in a structure that can withstand pressure explosion strength.

Due to the above configuration, the core of the water jacket part is not required in the production of this cylinder block'&),
In terms of external appearance, a recess is formed in the aluminum alloy part, making it easier to tighten bolts and improving workability. Only the upper part of the cylinder block is made of iron-based block with excellent properties.
The cylinder liner was made of steel, hardened and polished at low cost, making it extremely thin, improving cooling ability, eliminating the water jacket in the lower half, and narrowing the cylinder gap. Therefore, the entire cylinder block can be made smaller and lighter.

The central part of the cylinder, which tends to heat up easily, is made of iron and is made into a separate piece, allowing the heat-affected zone to have the same precision as conventional iron castings, eliminating the performance deterioration caused by changes in clearance between the pistons. Regardless of the wet structure, the upper circumference is beam welded and integrated to solve the problem of reduced rigidity. The inner surface of the steel pipe is hardened and polished to improve durability and reliability. Now that automation has progressed, mass production using methods such as having robots perform welding can be considered to have solved the difficulties of manufacturing steel sheets in terms of cost. Therefore, with the present invention, compared to conventional cast iron products, the steel plate part has a thinner wall thickness and the cooling water jacket volume is smaller, and the aluminum alloy part has less flab and has a slender body. The specific gravity is smaller than that of the cylinder block, making the entire cylinder block lighter, making it more likely that the cylinder block will be made of sheet metal or aluminum.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional cast iron cylinder block, Fig. 2 is a top plan view of the cylinder block according to the conventional example, Fig. 5 is a sectional view taken along line A-A in Fig. 2, and Fig. 4. 5 is a perspective view of a cylinder block according to the present invention, FIG. 5 is a plan view as seen from FIG. 4B, and FIG. 6 is a sectional view taken from FIG. 5 CC. 5... Steel plate part, 6... Aluminum alloy part, 7... Steel plate part upper plate, 8... Cylinder liner, 9... Cooling water jacket, 10... Bolt hole, 11...・Cylindrical part of aluminum alloy part.

Claims (1)

[Claims] (1) In the cylinder block of a piston engine, the upper half is made of steel plate and the lower half is made of aluminum alloy,
At the top of the steel plate block, a box-shaped main body is formed using a solid steel plate.A number of cylinder liners corresponding to the number of cylinders are welded and fixed to the steel plate part on the top surface, and the cylinder liners are double-walled. The structure forms a jacket for cooling water, and bolt holes are drilled on the top surface of the steel plate block so as to surround the cylinder/drill and nai, and cylinders and holes are drilled in the aluminum alloy block to match the steel plate block. A cylindrical part is provided for the liner, and a bolt hole is provided for the bolt hole.Furthermore, the cylinder/block assembly is performed by inserting the cylinder liner of the steel plate block into the cylindrical part of the aluminum alloy block, and firmly tightening the bolts. A lightweight cylinder block that is easy to assemble.