JPH05536B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cylinder head for a four-stroke internal combustion engine with a suspended intake valve and an exhaust valve.

Prior art German Patent Advertisement No. 1127144 (DE-B-
1127144), this type of cylinder head is
A total of three valves are arranged parallel to each other and in triangular correspondence, so that the boundary wall of the combustion chamber in the cylinder head is extremely flat. Also,
All the valve heads of these valves are in close contact with the cylinder wall, so that even in the open position the opening cross section of the valve is narrow in this cylinder wall region, which impedes gas exchange. Furthermore, the relatively small diameter of the valve head of the exhaust valve compared to the full opening cross section of the two intake valves also contributes to the obstruction of gas exchange. In addition, even if this known internal combustion engine is configured with spark ignition, the wide compression gap extends in an annular manner and also extends into the area of the exhaust valve, which is very hot during operation, so that the combustion process is not affected. This has an adverse effect and can cause spontaneous combustion in the area of the exhaust valve.

German Patent No. 708283 (DE
-C-708283), German Patent No. 755495 (DE
-C-755495) and magazine “Motorad”, 1980,
In the known cylinder head from Volume 24, pages 28 and 30, the intake and exhaust valves are arranged in a V-shape, but there are problems with the arrangement of the valves and spark plugs in relation to the configuration of the combustion chamber. However, the use of the combustion chamber wall is not satisfactory in synchronizing the valve size and the compression gap size, and on the other hand, the ignition is off-center, which has a negative effect on the combustion process.

A four-valve cylinder head with two intake valves and two exhaust valves arranged likewise in a V-shape is known from DE-A-2919213 (DE-A-2919213), but with an additional second The structure is complicated because it requires an exhaust valve and its control device. Also, since one intake valve and one exhaust valve interfere with each other's stroke, either the size of the valve or the size of the V-shaped angle is limited, thereby impeding gas exchange. . In this case, the spark gap of the spark plug is located approximately at the center of the four valves, but with this arrangement, there is a limit to the size of the exhaust valve when there are three valves.

Purpose The purpose of the present invention is to eliminate the conventional drawbacks, to enlarge the cross section of the valve opening, to enable ignition to be performed almost at the center of the combustion chamber, to make the combustion chamber compact, and to provide a combustion process. The arrangement of the intake valve and the configuration and arrangement of the compression gap should be considered so as to have a favorable influence on the performance.

Structure In order to achieve the above object, the present invention provides a cylinder head for a four-stroke internal combustion engine having intake valves and exhaust valves arranged in a suspended manner, in which two intake valves are arranged parallel to each other in each cylinder. the exhaust valve and the spark plug are arranged in a first plane equidistant from both intake valves and including the cylinder axis; The spark plug's spark gap is located approximately at the center of both intake valves.
A longitudinal axis of the spark plug extends at an outwardly open angle from said second surface determined by the axes of both intake valves, and the valve heads of the intake and exhaust valves are arranged in the cylinder in the closed position. A four-cycle engine, in which an axis that is substantially tangent to the circular outline, intersects at right angles to the first surface, and passes through the center of the circular outline overlaps the valve head of the intake valve when viewed from the side of the partition between the cylinder and the cylinder head. In the cylinder head of an internal combustion engine, two intake valves arranged parallel to each other in each cylinder are arranged so as to form a V-shape with said one exhaust valve, and the longitudinal axis of the spark plug and the exhaust the second intake valve, the angle formed with the axis of the valve being determined by the axes of both intake valves;
is larger than the angle formed by the plane of the exhaust valve and the axis of the exhaust valve, the diameter of the valve head of the exhaust valve is approximately equal to the radius of the circular outline of the cylinder, and the angle between the intake valve and the spark plug is A compression surface is formed between the circular outlines of the cylinder, the compression surface forming an interface of a compression gap defined by the compression surface and the bottom portion of the attached piston. It is something.

Effect: Arranging the valve and spark plug according to the present invention,
By providing only one exhaust valve,
An enlarged valve cross section and a compact configuration of the combustion chamber are obtained, and the ignition can be located approximately in the center of the combustion chamber. Also, by arranging the intake valve according to the invention, the configuration and arrangement of the compression gap is advantageous, which has a favorable influence on the combustion process.

Embodiment Next, one embodiment of the present invention will be described with reference to the accompanying drawings.

The cylinder head 1 of a spark-ignited four-stroke internal combustion engine has three valves 2 and 3 arranged in a V-shape. Two of these intake valves 2 are arranged parallel to each other corresponding to the V-shaped sides determined by the surfaces of these intake valves. The angle that the intake valve 2 forms with the cylinder axis 4 is approximately 37°. On the other hand, the V-shaped side determined by the exhaust valve 3 forms an angle of approximately 15° with the cylinder axis 4. The camshaft 5 has an angle formed by the intake valve 2 and the exhaust valve 3, that is, approximately
It is located on the line that bisects 52°. camshaft 5
and the intake valve 2 and the exhaust valve 3,
One rocker arm 6 in each case is rotatably arranged on a bearing shaft 7.

When the intake valves 2 and exhaust valves 3 are arranged in a V-shape as described above, both the intake valves 2, and therefore their valve heads 2', can be arranged at a relatively large arbitrary interval, and the spark plugs 8 can be arranged in a V-shape. In conjunction with this spacing of the spark gap, the combustion chamber 9 can be configured in a manner favorable for the size of the valve opening cross-section and the combustion process. For this reason, the valve heads 2' and 3' also closely adjoin the circular outline 10' of the cylinder 10, and the valve head 2' is located at a relatively narrow distance from the valve head 3'. Valve head 3' of exhaust valve 3
The diameter of the cylinder 10 is approximately equal to the radius of the cylinder 10. As can be seen from FIG. 2, an axis 10'', which is equidistant from both intake valves 2, intersects at right angles to a plane containing the cylinder axis 4, and passes through the center of the circular outline 10', Valve head 2' of intake valve 2 when viewed from the partition surface side of head 11
There is an overlap. In this way, intake valve 2
By arranging the exhaust valve 3 or its valve heads 2' and 3', and arranging the spark gap of the spark plug 8 between the valve heads 2', the opening cross section of the intake valve 2 and the exhaust valve 3 can be changed. They can be conveniently synchronized with each other and the spark gap of the spark plug 8 can be set approximately in the center of the combustion chamber 9. Therefore, it is advantageous in terms of performance and fuel consumption.

In the region of the combustion chamber 9 outside the valve head 2' of the intake valve 2, a relatively large compression surface 11 is formed. This compression surface 11, together with the flat bottom part 12' of the piston 12, forms a compression gap which favorably influences the combustion process.

The longitudinal axis of the spark plug 8 and the cylinder axis 4
The angle formed by the valve shaft of the intake valve 2 and the cylinder axis 4 is
is larger than the angle formed by Therefore, spark plug 8
The mounting space does not affect the mounting space of the valve spring 13 of the intake valve 2. The spark plug 8 and its electrical connection are also located in a particularly convenient position for servicing the intake side of the cylinder head 1, which has a relatively low temperature during operation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a cylinder head of a four-stroke internal combustion engine according to the present invention, and FIG. 2 is a cross-sectional view taken along the line of FIG.
FIG. 3 is a sectional view showing the inside of the combustion chamber of the cylinder head. 1...Cylinder head, 2...Intake valve, 2'...
...Intake valve head, 3...Exhaust valve, 3'...Exhaust valve head, 4...Cylinder shaft, 5...Camshaft, 6...
...Swinging arm, 7...Support shaft, 8...Spark plug, 9
... combustion chamber, 10 ... cylinder, 11 ... compression gap, 12 ... piston, 12' ... bottom part of piston, 13 ... valve spring.

Claims (1)

[Scope of Claims] 1. A cylinder head 1 for a four-stroke internal combustion engine having an intake valve 2 and an exhaust valve 3 arranged in a suspended manner, in which two intake valves 2 are arranged parallel to each other in each cylinder 10. , the exhaust valve 3 and the spark plug 8 are
The exhaust valve 3 is located in a first plane that is equidistant from both intake valves 2 and includes the cylinder axis 4.
are arranged at a distance from a second plane determined by the axes of both intake valves 2, the spark gap of the spark plug 8 is approximately at the center of both intake valves 2, and the longitudinal axis of the spark plug 8 is , extending at an outwardly open angle from said second surface determined by the axes of both intake valves 2, the valve heads 2' of the intake valves 2 and exhaust valves 3;
3' substantially tangent to the circular outline 10' of the cylinder 10 in the closed position, an axis 1 that intersects at right angles to said first surface and passes through the center of the circular outline 10';
0'' are arranged parallel to each other in each cylinder 10 in the cylinder head 1 of the four-cycle internal combustion engine, which overlaps the valve head 2' of the intake valve 2 when viewed from the side of the partition between the cylinder 10 and the cylinder head 11. The two intake valves 2 are arranged to form a V-shape with the one exhaust valve 3, and the angle between the longitudinal axis of the spark plug 8 and the axis of the exhaust valve 3 is equal to The angle between the second surface determined by the axis of the intake valve 2 and the axis of the exhaust valve 3 is greater than the angle formed by the axis, and the diameter of the valve head 3' of the exhaust valve 3 is larger than the circular outline 10 of the cylinder 10. ', and a compression surface 11 is formed between the intake valve 2 and the spark plug 8 and between the intake valve 2 and the circular outline 10' of the cylinder 10; 1
1. A cylinder head for a four-stroke internal combustion engine, characterized in that it forms an interface between compression defined by the bottom portion 12' of the associated piston 12.