JPS639131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder block for an internal combustion engine.

As a cylinder block for an internal combustion engine, for example, cylinder blocks shown in FIGS. 1 and 2 have already been proposed. (See "Second Report on Automobile Pollution Prevention Technology" published by the Environment Agency in May 1981). To explain the structure of the cylinder block of this internal combustion engine,
1 is a cylinder block body, and a cylinder head 2 and an oil pan 3 are fixed to the upper and lower ends of the cylinder block body 1, respectively. A plurality of cylinders 4 are formed in the upper part of the cylinder block body 1, and a plurality of bulkheads 6 protrude from the skirt portion 5 of the cylinder block body 1 at predetermined intervals from each other in the length direction. Bearing caps 7 are fixed to these bulkheads 6 by bolts 8, and as shown in detail in FIG. It has one beam part 10 that connects the parts. The aforementioned bulkhead 6 and bearing cap 7 together constitute a main bearing 11, and as shown in FIGS. 1 and 2 again, a crankshaft 12 is rotatably supported by the main bearing 11. A piston (not shown) that is slidably housed in the cylinder 4 is connected to the crankshaft 12, and when the piston receives an impact combustion force and reciprocates within the cylinder, the crankshaft 12 converts this into rotational motion. Convert. However, in the case of such a cylinder block, the bearing cap was composed of multiple cap parts and a single beam part connecting the lower central parts of these parts, so the impact combustion force generated within the cylinder was applied to the main bearing. When the transmission is transmitted, the cap section causes torsional vibration,
This has caused a problem in that it increases the noise generated by the cylinder block body during operation of the internal combustion engine.
Furthermore, since the shape of the bearing cap is complex, there is a high percentage of defective products that occur during manufacturing, and if it is stored on a pallet with other parts for internal combustion engine assembly, it may become tangled with other parts and become careless. There was also the problem that it would bend when handled.

The present invention was made in view of these conventional problems, and includes a plurality of bulkheads provided on a cylinder block, and a bearing cap that together with the bulkheads forms a main bearing that supports a crankshaft. , the bearing cap is composed of a bearing beam part and a cap part, and the bearing beam part is composed of a plurality of beams that are parallel to each other and connected at appropriate points, and the beams are positioned on the outside of the bearing cap. It is an object of the present invention to solve the above-mentioned problems by providing a cylinder block for an internal combustion engine in which the bearing beam part is a separate body that can be attached to and detached from the cap part.

Hereinafter, this invention will be explained based on the drawings.

4 and 5 are diagrams showing an embodiment of the present invention, and the configuration will be explained first. Note that the same reference numerals are given to the parts having the same structure as the cylinder block of the already provided internal combustion engine described above, and the explanation thereof will be omitted. 15 is a bearing cap, and this bearing cap 15 has a bearing beam portion 16 and a plurality of cap portions 17. As shown in detail in FIG. 6, the bearing beam section 16 includes two beams 18 and 19 that are parallel to each other and positioned on the outside of the bearing cap 15.
and a connecting portion 20 that bridges these beams 18 and 19. Bolt holes 21 and 22 are formed on both sides of the connecting part 20, and bolt holes 23 and 22 are formed on both sides of the cap part 17.
24 is placed on the connecting portion 20 so as to align with the bolt holes 21 and 22, and is fixed to the bulkhead 6 together with the bearing beam portion 16 by bolts 25 and 26. As a result, cap portion 17 is located between beams 18 and 19. The aforementioned bulkhead 6 and bearing cap 15 constitute a main bearing 27 as a whole. In this way, since the bearing beam part 16 and the cap part 17 are separate bodies, the shapes of both the bearing beam part 16 and the cap part 17 are simplified, and the proportion of defective products that occur during their manufacture is reduced. Even if it is stored in a pallet with other parts, there is no risk of it becoming entangled with other parts.

Next, the action will be explained.

During operation of the internal combustion engine, the impact combustion force generated within the cylinder 4 is transmitted to the cap portion 17 of the main bearing 27 via the piston and crankshaft 12. As a result, the cap portion 17 tends to twist in the direction of arrow A in FIG. are further connected to each other by beams 18 and 19, so that twisting is suppressed. In addition, the cap portion 17
The height of the bearing cap 17 is equal to the height of the connecting portion 20 plus the height of the connecting portion 20, and the downward deflection of the bearing cap 15 is restricted.
9, so the bearing cap 15
Vibrations in the longitudinal direction are also regulated. Furthermore, beam 1
8 and 19 are located on the outside of the cap portion 17, the torsional rigidity of the cylinder block body 1 is improved. Therefore, the vibration of the cylinder block body 1 is suppressed, and the noise accompanying the vibration can be reduced.

In addition, the cap part 17 cylinder block body 1
If they are made of the same material, for example, cast iron or aluminum-based light metal, the bolt holes 23, 24 of the cap portion 17 and the bolt holes of the bulkhead 6 can be easily machined in one piece. Furthermore, if these are made of aluminum-based light metal, the Young's modulus/density of aluminum-based light metal is greater than that of cast iron, so it is effective in suppressing vibration.

As described above, the present invention includes a plurality of bulkheads provided on a cylinder block of an internal combustion engine, and a bearing cap that forms a main bearing that supports a crankshaft together with the bulkhead, and the bearing cap is attached to a bearing beam. The bearing beam part is composed of a plurality of beams that are parallel to each other and connected at appropriate points, and the beams are located outside of the bearing cap, and the bearing beam part is By making the cap part a detachable part, it is possible to reduce the noise of the cylinder block body, and also to reduce the proportion of defective products that occur when manufacturing bearing caps. This has the effect that even if it is stored in the storage area, it will not become entangled with these items.

[Brief explanation of the drawing]

Figure 1 is a front view of the cylinder block of an internal combustion engine that has already been proposed, and Figure 2 is the same as that shown in Figure 1.
3 is an enlarged perspective view of the bearing cap shown in FIG. 2, FIG. 4 is a partially sectional front view showing an embodiment of the cylinder block for an internal combustion engine according to the present invention, and FIG. FIG. 4 is a sectional view taken along the - arrow, and FIG. 6 is an enlarged perspective view of the bearing cap shown in FIG. 5. 1... Cylinder block, 6... Bulk head, 12... Crankshaft, 15... Bearing cap, 16... Bearing beam section, 1
7... Cap part, 18, 19... Beam, 27
...Main bearing.

Claims (1)

[Claims] 1 A cylinder block comprising a plurality of bulkheads provided on a cylinder block and a bearing cap which together with the bulkhead forms a main bearing that supports a crankshaft, a cap portion to which the bearing caps are fixed to each bulkhead, and a bearing that connects these cap portions. In the cylinder block for an internal combustion engine having a beam part, the bearing beam part is composed of a plurality of beams that are parallel to each other and connected at appropriate points, and the beams are located outside of the bearing cap, and the bearing A cylinder block for an internal combustion engine, characterized in that the beam part is a separate body that can be attached to and detached from the cap part.