JPH07127554A - Ignition device for multiple cylinder engine - Google Patents

Abstract

PURPOSE:To reduce unevenness of ignition characteristic caused by loss of high voltage by unifying high voltage electric wires for ignition coils in a short length, and also reduce its cost by making high pressure electric wires commonly usable. CONSTITUTION:Each of individual ignition coils 3a, 3b,... is provided per cylinder in a multiple cylinder engine 1. Respective high pressure electric coils 5a, 5b,... are wired from ignition coils 3a, 3b,... to spark plugs 4a, 4b,... of cylinders respectively. Respective ignition coils 3a, 3b,... are driven by an ignition control means 6, ignition spark is splashed to respective spark plug 4a, 4b,... in ignition order. An installing stay 8 for installing respective ignition coils 3a, 3b,... is provided on the head cover 7 of the multiple cylinder engine 1, and respective coil installing parts 9a, 9b... of the ignition coils 3a, 3b,... are superposed on each other, so as to be arranged and fixed in a zigzag shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition system for a multi-cylinder engine, and more particularly to an ignition system for a multi-cylinder engine having a separate ignition coil for each cylinder.

[0002]

2. Description of the Related Art In the conventional ignition system for a multi-cylinder engine, in addition to the well-known technique in which the output of one ignition coil is distributed to each ignition plug of each cylinder by a high voltage distributor, as shown in FIG.
Some are configured as follows: That is, separate ignition coils 3a, 3b ... Are provided for each cylinder 2a, 2b ... Of the multi-cylinder engine 1. Then, the high voltage electric wires 5a, 5b ... Are wired from the ignition coils 3a, 3b ... To the spark plugs 4a, 4b. Further, the ignition coils 3a, 3b ... Are driven by the ignition control means 6 so that ignition sparks are emitted to the spark plugs 4a, 4b ... In accordance with the ignition order of the cylinders 2a. 2b. is there. Reference numeral 10 is an ignition timing detection plate of the ignition control means 6, reference numeral 11 is an ignition timing detection sensor facing the outer periphery thereof, and reference numerals 29a and 29b.
Is a piston, and reference numeral 30 is a power battery.

[0003]

The above-mentioned conventional techniques have the following problems. If the high voltage electric wires 5a, 5b ... Wiring to the respective ignition plugs 4a, 4b ... of the respective cylinders 2a, 2b ... Are long, the ignition coils 3a, 3b. Therefore, it is better to install it on the engine body as close as possible to the spark plugs 4a, 4b ...
There is a problem with heat resistance and durability in places with high temperatures.
Further, when the number of cylinders of the engine is large and the number of ignition coils is increased, they are individually arranged in appropriate mounting spaces, so that the ignition coils 3a, 3b ...
The distance to 4b ... becomes long and short, the unevenness of the ignition characteristics becomes large, and the high-voltage electric wires 5a, 5b. An object of the present invention is to unify the high voltage electric wires of the ignition coil so as to shorten the unevenness of the ignition characteristics due to the loss of high voltage and to reduce the cost by making them common.

[0004]

In order to achieve the above object, the present invention adds the following improved structure to the above prior art as shown in FIGS. 1 to 3, for example. That is, a mounting stay 8 for mounting the ignition coils 3a, 3b ... Is provided on the head cover 7 of the multi-cylinder engine 1. Then, on the mounting stay 8, the coil mounting portions 9a, 9b, ... Of the ignition coils 3a, 3b ,.

[0005]

The operation and effect of the present invention is constructed as described above, and operates and effects as follows. Mounting stay 8
In the above, each coil attachment portion 9a of each ignition coil 3a, 3b ...
.. 9b ... are stacked on each other to have a compact mounting length, and the high voltage electric wires 5a, 5b ... Are mounted in a staggered manner so as not to interfere with each other. The mounting stay 8 is fixed to the head cover 7 close to the spark plugs 4a, 4b ... Of the cylinders 2a. Therefore, the distance between the ignition coils 3a, 3b ... And the spark plugs 4a, 4b .. In addition to reducing the loss, the lengths of the high-voltage electric wires 5a, 5b ... Can be made common and common. This makes it possible to shorten and unify the high-voltage wires of the ignition coil, reduce unevenness in ignition characteristics due to loss of high voltage, and reduce cost by sharing them.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (A) is a side view of a main part of an ignition device for a multi-cylinder engine, FIG. 1 (B) is a top view of the ignition coil and a mounting stay, and FIG.
FIG. 3 is a top view of a multi-cylinder engine. In the figure, a multi-cylinder engine 1 has a cylinder block 21 integrally formed above a crankcase 20, and a cylinder head 22 and a head cover 7 are sequentially mounted and fixed on the upper surface of the cylinder block 21 to form an engine body. There is.
The cylinder head 22 is provided with the cylinders 2a
b ... for each intake port 23a, 23b ..., exhaust port 24
are formed, and spark plugs 4a, 4b ... and intake / exhaust valves (not shown) are provided facing the combustion chambers 25a, 25b.

Further, each cylinder 2 of the multi-cylinder engine 1
a. 2b ... Separate ignition coils 3a, 3b ...
Is equipped with. Further, on the head cover 7, a mounting stay 8 for mounting the ignition coils 3a, 3b ...
For example, the head cover fastening bolts 26a, 26b ... Are fastened together with the cylinder head 22 and fixed to the engine body. Then, on the mounting stay 8, the coil mounting portions 9a, 9b of the ignition coils 3a, 3b, ... Are superposed on each other to have a compact mounting length, and the high voltage electric wires 5a, 5b ,. In order not to do so, they are arranged in a zigzag pattern and fixed with collars 8a, mounting bolts 8b and the like. Further, the high voltage electric wires 5a, 5b ... Are wired from the ignition coils 3a, 3b ... To the spark plugs 4a, 4b ... of the cylinders 2a, 2b. The ignition coils 3a, 3b ... Are driven by the ignition control means 6 so that ignition sparks are emitted to the spark plugs 4a, 4b ... In accordance with the ignition order of the cylinders 2a. . Further, on the front side of the engine body of the multi-cylinder engine 1, the ignition timing detection plate 10 of the ignition control means 6 is fixed by a center bolt 27a to the front surface of a drive pulley 28 fixed to the tip of the crankshaft 27. .
Reference numeral 30 is a power battery, and reference numeral 31 is a flywheel.

FIG. 3 is a sectional view of an essential part showing the ignition timing detection plate 10 and the drive pulley 28 of the ignition control means 6. The ignition timing detection plate 10 is fastened to the center hole 10a of the ignition timing detection plate 10 and the rotation axis center of the crank shaft 27 in order to maintain a gap G between the ignition timing detection sensor 11 and the outer periphery thereof. The center bolt 27a is fitted with the fitting portion 27b, and is fixed so that there is no deviation in the outer peripheral direction. Further, on the outer periphery of the ignition timing detection plate 10, the same number of ignition timing indicators 13a, 13b ... And 1 as the number of cylinders of the multi-cylinder engine 1 (three cylinders in the embodiment) are provided.
The individual starting point indicating portions 14 are provided in a protruding manner. Further, the ignition timing detection plate 10 is provided with a relief hole 15 for the power take-out boss 28a of the drive pulley 28, a matching mark hole 16 and the like so that it can be used for various types of drive pulleys. It is configured in a curved shape. Thereby, the ignition timing detection plate 10 can be shared and the cost can be reduced. still,
Reference numeral 10b is a rotation stop screw, and reference numeral 32 is a drive belt.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 (A) is a side view of a main part of an ignition device for a multi-cylinder engine, and FIG. 1 (B) is a top view of the ignition coil and a mounting stay.

FIG. 2 is a top view of a multi-cylinder engine showing an embodiment of the present invention.

FIG. 3 shows an embodiment of the present invention, FIG. 3 (A) is a sectional view of an essential part of an ignition timing detection plate and a drive pulley, and FIG. 3 (B) is a front view of the ignition timing detection plate.

FIG. 4 is a system diagram of an ignition device for a multi-cylinder engine, showing a conventional example.

[Explanation of symbols]

1 ... Multi-cylinder engine, 2a / 2b ... Cylinder, 3a / 3b ...
Ignition coil, 4a, 4b ... Spark plug, 5a, 5b ... High-voltage electric wire, 6 ... Ignition control means, 7 ... Head cover, 8 ... Mounting stay, 9a. 9b ... Coil mounting portion.

Claims (1)

[Claims] 1. A cylinder (2a.2) of a multi-cylinder engine (1).
b) each has a separate ignition coil (3a, 3b ...), and each of the ignition coils (3a, 3b ...)
.2b ...) to the spark plugs (4a.4b ...), respectively, to connect high-voltage electric wires (5a.5b ...), and to drive the ignition coils (3a.3b ...) by the ignition control means (6). , An ignition device for a multi-cylinder engine configured to blow an ignition spark to each of the spark plugs (4a, 4b ...) in accordance with an ignition order of each of the cylinders (2a, 2b ...), wherein a head cover of the multi-cylinder engine (1) (7) Mounting stay for mounting the ignition coils (3a, 3b ...) on the top
(8) is provided, and the ignition coils (3a, 3a) are mounted on the mounting stay (8).
An ignition device for a multi-cylinder engine, characterized in that the coil attachment parts (9a, 9b ...) of (b) are arranged one above the other in a staggered arrangement.