JPS6029658Y2 - cylinder block of internal combustion engine - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a cylinder block for an internal combustion engine.

For example, the cylinder block of an internal combustion engine is shown in Figures 1 to 3.
As shown in the figure, a main journal 4 for pivotally supporting a crankshaft is formed at the center of the lower end of a bulkhead 3 that partitions each cylinder 2 of a cylinder block 1, and skirt portions 5 are formed on both sides of this bulkhead 3. It has a structure that supports the crankshaft by connecting it to the
(Refer to pages 365 and 409 of Internal Combustion Engine Handbook, published by Asakura Shoten Co., Ltd. on March 30th).

However, in the conventional case, the joint portion between the bulkhead 3 and the skirt portion 5 is simply connected in a substantially T-shape as shown in the third figure, and the width between adjacent joint portions is long and the joint rigidity is low.

For this reason, the main journal 4 due to engine explosion pressure
The left and right vibrations of the skirt portion 5 shown by the broken line in FIG. 3 caused by the deformation of the bulkhead 3 through the
There was a problem in that the noise from the skirt portion 5 was large.

The present invention has been developed in view of the above-mentioned circumstances, and involves branching the joint part of the bulkhead to the skirt part in the front and back, and connecting the parts to the skirt part so as to form a substantially triangular space on the lower surface of the joint. The purpose is to solve the conventional problems by increasing the rigidity of the connection between the two.

Hereinafter, embodiments of the present invention will be described based on the drawings.

4 to 6, a main journal 14 for pivotally supporting a crankshaft is formed at the center of the lower end of a bulkhead 13 that partitions each cylinder 12 of a cylinder block 11. As shown in FIGS.

On both sides of the bulkhead 13, the lower end side branches into the front and back, respectively, and the branching path 13a increases toward the upper side of the cylinder block 11.

13a approaches and is combined with the skirt portion 15 to form a substantially triangular pyramid shape.

In this configuration, both sides of the bulkhead 13 are divided into two branches in the front and back, and the branch portions 13a thereof.

13a is connected to the skirt portion 15 of the cylinder block 11, the rigidity of the connection between the bulkhead 13 and the skirt portion 15 is higher than that of the conventional case where a panel-shaped bulkhead is extended to the skirt portion and connected. As the distance increases, the distance between adjacent joints becomes narrower, and the skirt portion 15 is substantially divided into smaller parts than before, so that the vibration becomes smaller as shown by the broken lines in FIG.

Therefore, the vibration level can be greatly reduced and the generated noise can be significantly reduced.

7 to 9 show another embodiment.

In the figure, branch portions 22a, 22a on both sides of the bulkhead 22 of the cylinder block 21 extend substantially vertically upward, and are combined with the skirt portion 23 to form a substantially triangular prism shape.

Further, the bulkhead 22 is formed into a flat plate shape with no irregularities so that the mold can be easily pulled out downward.

24 is a relief part of the piston skirt part.

This embodiment is suitable when the cylinder block is made of a light alloy such as aluminum.

According to this embodiment, even if the cylinder block is made of a light alloy, there is no need to use complicated molds such as split molds compared to the previous embodiment, and the extremely simple mold allows for easy casting. Improved cylinder block productivity - lower manufacturing costs.

In an internal combustion engine having a four-counter crankshaft as shown in FIG. Rigidity can be improved more effectively by making the width between the two bulkhead branches wider than between the other bulkhead branch parts.

As described above, according to the present invention, the skirt connecting portion of the bulkhead is branched back and forth so as to form a substantially triangular space on the lower surface thereof, and is connected to the skirt portion. The joint rigidity between the engine and the skirt section is greatly improved, and the vibration of the skirt section caused by the engine's explosion pressure can be greatly suppressed, making it possible to significantly reduce noise.

[Brief explanation of the drawing]

1 to 3 are views showing an example of a conventional cylinder block, in which FIG. 1 is a sectional view, FIG. 2 is a bottom view, and FIG. 3 is a sectional view taken along the line A-A in FIG. 4 to 6 are views showing one embodiment of the present invention, in which FIG. 4 is a sectional view, FIG. 5 is a bottom view, and FIG. 6 is a sectional view taken along the line B-B in FIG. Figures 7 to 9 are views showing other embodiments, with Figure 7 being a sectional view and Figure 8 being a sectional view.
9 is a sectional view taken along the line CC in FIG. 7, and FIG. 10 is a bottom view showing an example applied to a 4-cylinder, 4-counterweight crankshaft engine. 11.21...Cylinder lock, 13.22
...Bulkhead, 13a, 22a...
- Branch part, 15.23...Skirt part.

Claims (1)

[Scope of utility model registration request] A cylinder block for an internal combustion engine having a skirt portion, characterized in that the connecting portion of the bulkhead to the skirt portion is branched back and forth so as to form a substantially triangular space on the lower surface thereof by joining with the skirt portion. Cylinder valves and locks for internal combustion engines.