JPS5928105Y2 - 2-point ignition engine - Google Patents

Description

[Detailed description of the invention] The present invention relates to an engine that is equipped with two spark plugs in the engine combustion chamber and ignites at two points.In particular, the spark plug is arranged to prevent interference with other engine components, and its attachment and detachment are improved. It is something to improve.

Two spark plugs are installed relatively far apart from each other in the combustion chamber of the engine, and the exhaust gas recirculation rate (exhaust recirculation amount relative to the amount of intake air) is extremely high, with a maximum value of 25 to 45%. The present applicant has already proposed a two-point ignition engine that can significantly reduce nitrogen oxides (NOx) without impairing engine operating performance by performing two-point ignition.

It is most preferable to arrange these spark plugs so that the ignition point is approximately symmetrical with respect to the center of the cylinder when looking at the engine in plan. It is extremely difficult to ideally arrange a spark plug in a limited space due to its relationship with ports, intake and exhaust valves, or their valve operating mechanisms.

Furthermore, since the spark plug is frequently removed and installed during engine maintenance and maintenance, it is necessary to determine its installation position with due consideration given to its ease of installation and removal.

The present invention was proposed to solve this problem, and it avoids interference with intake and exhaust valves, valve mechanisms, and even carburetors, and is easy to attach and detach without impairing the combustion characteristics of two-point ignition. To provide a two-point ignition engine in which an ignition plug is placed at a position where the ignition plug is placed at a certain position.

Examples will be described below based on the drawings.

Figure 1 shows an embodiment in which the present invention is applied to a four-cylinder engine.
2a*2bt2C and 2d indicate the cylinder head body, and the combustion chamber.

And intake valves 3b of the two cylinder combustion chambers 2b and 2c closer to the center in plan projection.

3c is offset inward with respect to the center M in the direction of the cylinder head center line X connecting the centers M of each cylinder,
One of the spark plugs 5b and 5c is attached to the side of the intake manifold 4 located outside of the intake manifold 4.

Furthermore, the exhaust valves 6b, 6c of these combustion chambers 2b, 2c are offset to the outside opposite to the intake valves 3b, 3c, and the other spark plug 7b is attached from the mounting side of the exhaust manifold 8. 7c is disposed inside the cylinder center M, and is connected to the ignition points of the spark plugs 5b and 7b as well as the spark plug 5.
The ignition points of cylinders c and 70 are positioned so that they are substantially symmetrical to each other with respect to the cylinder center M.

In the combustion chambers 2a and 2d of the two outer cylinders in the direction of the cylinder head center line X, the intake valve 3 is
a, 3d are arranged on the outside, spark plugs 5a, 5d on the intake manifold 4 side are arranged on the inside, exhaust valves 6a, 6d are also arranged on the inside, and spark plugs 7a, 7d on the exhaust manifold 8 side are arranged on the outside. .

The spark plugs 5b, 5c of the central combustion chambers 2b, 2c are placed outside the cylinder center M to prevent interference with the carburetor 10, but the spark plugs 5a, 5d of the combustion chambers 2a, 2d on both needle sides are Since there is no interference with the carburetor 10, it is not necessarily necessary to do it as in this example, but if you do it as in this example, the exhaust port 9a.

9b, 9ct, 9d, which have 5 adjacent cylinders, it is possible to merge exhaust ports 9a and 9b and 9c and 9d in the cylinder head body 1 to form a so-called Siamese port. This prevents the exhaust gas temperature from decreasing and reduces end-combustion harmful components (HC,
CO) oxidation efficiency can be improved.

Note that Ila, 11b=11c and 11d indicate intake ports.

In addition, 12 is an exhaust gas recirculation passage for recirculating a part of the exhaust gas into the intake air, and 13 is a control valve that controls the amount of recirculation. The value is set to .

In this way, since the spark plugs 5a to 5d and 7a to 7d are arranged on different sides of the cylinder head center line X, the intake manifold 4 side and the exhaust manifold 8 side, each spark plug 5, 70 The ignition point can be arranged almost symmetrically with respect to the cylinder center M without interfering with the intake and exhaust valves 3 and 6 or the intake and exhaust ports 11°9, and therefore even when high-rate exhaust gas recirculation is performed. Maintains fast combustion characteristics due to two-point ignition, and produces NO without impairing engine operating performance.
A reduction in x can be achieved.

In particular, the spark plugs 5b and 5c on the intake manifold 4 side of the combustion chambers 2b and 2c of the two cylinders near the center are arranged outside the cylinder center M in the direction of the center line X, in other words, outside the intake valves 3bt3c. , spark plug 5b, 5c
Interference with the carburetor 10 can be avoided during attachment and detachment, and attachment and detachment can be easily performed.

In this embodiment, the spark plugs 5b and 5c are aligned with the center line
Although it is arranged in a direction perpendicular to this, it may also be inserted in a direction oblique to this, that is, from an obliquely outer side.

Next, FIG. 2 shows an embodiment in which the present invention is applied to a six-cylinder engine.
Outside of the intake valves 23c and 23d (in the center line X direction)
There is no difference between arranging the spark plugs 25a to 25f and the ignition plugs 27a to 27f on different sides of the cylinder head with respect to the center line X in each combustion chamber 22a to 22f. As a result, as in the first embodiment, the spark plugs 25, 27 can be placed at ideal positions for two-point ignition without interfering with other components.

As described above, according to the present invention, the ignition plug can be installed in the most suitable position without interfering with other components, and the combustion characteristics of a two-point ignition engine can be improved.

The exhaust characteristics can be further improved, and the ignition plug can be easily attached and detached, making maintenance and inspection easier.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the first embodiment, and FIG. 2 is a plan view of the second implementation row. 1... Cylinder head body, 2a, 2b, 2c
. 2d... Combustion chamber, 3a, 3b, 3ct 3d
...Intake valve, 4...Intake manifold, 5at 5b, 5c+5d...Spark plug, 6
a, 6b, 6c, 6d...exhaust valve? a, 7b
-7c, 7d... Spark plug, 8... Exhaust manifold, 10... Carburetor.

Claims (1)

[Scope of utility model registration request] In a multi-cylinder two-point ignition engine that has two spark plugs located relatively apart from each other in the engine combustion chamber, the intake and exhaust ports are shaped like a cross-flow type, and the cylinder head centerline is the boundary on the plane projection. , ignition plugs are arranged on the intake manifold side and the exhaust manifold side, and the ignition plugs on the intake manifold side of the two central cylinders are located outside of the intake valves in the direction of the center line of the cylinder head,
Two points characterized in that the spark plugs on the exhaust manifold side of the two central cylinders are located inside the exhaust valves in the direction of the center line, and the spark plugs of each cylinder are provided at positions that are approximately symmetrical with respect to the center of the cylinder. ignition engine.