JPS5941310Y2 - Cylinder block of an in-line 4-cylinder engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder block of an in-line four-stroke engine, and particularly to the arrangement of cylinder bores thereof.

In recent years, we have reduced the weight of pistons, connecting rods, crankshafts, etc. to reduce reciprocating inertia, and increased the balance ratio of the counterweight to reduce the load on the main bearings and reduce the gap between cylinder bores.
Attempts have been made to shorten the overall length of the cylinder block.

For example, Japanese Patent Laid-Open No. 54-99824 describes that the cylinder spacing is reduced in order to shorten the overall length of the engine and reduce its weight.

However, one factor that hinders shortening of the total length of the cylinder block is the durability of the cylinder rad gasket.

That is, as the distance between the cylinder bores becomes smaller, a problem arises in that the heat load on the Rad gasket of the cylinder between the bores increases, causing deterioration and damage.

On the other hand, in a 4-cycle in-line 4-cylinder engine, combustion occurs in the order of 1-3-4-2-1 or 1-2-4-3-1 cylinders, with the first cylinder and the second cylinder And combustion occurs continuously between the third and fourth cylinders,
This does not occur continuously between the second and third cylinders.

Therefore, if we consider the heat load to the cylinder Rad gasket between the cylinder bores of each cylinder in a 4-cycle in-line 4-cylinder engine, the heat load between the cylinder bores of the 1st and 2nd cylinders, and between the 3rd and 4th cylinders. It can be seen that while heat from combustion is continuously received from both sides, the heat load between the cylinder bores of the second and third cylinders in the center is smaller than that of the former because the cylinder bores do not receive heat continuously from both sides. .

The present invention was made based on the above consideration, and is directed to a cylinder block of a 4-cycle in-line 4-cylinder engine having cylinder bores for the first, second, third, and fourth cylinders arranged in rows. The distance between the cylinder bores of the second cylinder and the third cylinder is made smaller than the distance between the cylinder bores of the first cylinder and the second cylinder, and the distance between the cylinder bores of the third cylinder and the fourth cylinder, thereby shortening the overall length of the cylinder block. .

Hereinafter, the present invention will be explained in detail according to embodiments shown in the drawings.

1.2, 3.4 indicate the first, second, third, and fourth cylinders, respectively, and each cylinder 1, 2, 3, and 4 is a cylinder bore 1 arranged in a line in the cylinder block 5. a,
It is composed of cylinder heads 2a, 3a, 4a and a cylinder head 6.

7 is a piston, 8 is a connecting rod, and 9 is a crankshaft.

Although not shown, each of the cylinders 1 to 4 is equipped with a known intake and exhaust valve, a spark plug assembly, or a fuel injection nozzle. −
The combustion is performed in the order of 2-4-3-1 cylinders.

10, the cylinder head sandwiched between the cylinder block 5 and the cylinder head 6 is a socket.

The cylinder bores 1a to 4a of each cylinder formed in the cylinder block 5 are such that the distance L23 between the cylinder bores 2a and 3a of the second cylinder 2 and the third cylinder 3 is the same as that of the first cylinder 1 and the second cylinder 2.
Distance L12 between cylinder bores la and 2a, and interval L between cylinder bores 3a and 4a of third cylinder 3 and fourth cylinder 4.
34.

By making L23 smaller than L12 and L34, the second cylinder 2 and third cylinder 3 of the cylinder gasket 10
The part A between the cylinders 0 and 0 is smaller than the other parts B and C between the cylinders, but since the combustion in the second and third cylinders is not continuous, the heat load is small and sufficient durability can be achieved. I can do it.

Although the cylinder bore in the above embodiment does not use a liner, it is not the case that the same applies to cylinder bores in which a liner is used.

As described above, the present invention was developed by considering the combustion order of a 4-cycle in-line 4-cylinder engine and the heat load on the radial gasket to the cylinder.・It enables miniaturization.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an engine using a cylinder block according to the present invention, and FIG. 2 is a plan view of the cylinder block of FIG. 1. 1: 1st cylinder, 2: 2nd cylinder, 3: 3rd cylinder, 4: 4th cylinder
Cylinder, 1a to 4a cylinder bore, 5 cylinder block.

Claims (1)

[Scope of utility model registration request] A button on the cylinder block of a 4-cycle in-line 4-cylinder engine with cylinder bores for the first, second, third, and fourth cylinders arranged in a row, and between the cylinder bores of the second and third cylinders where the combustion order is not consecutive. A cylinder block for an in-line four-cylinder engine, characterized in that the interval is smaller than the interval between the cylinder bores of the first and second cylinders and the third and fourth cylinders whose combustion order is consecutive.