JPS6357873A - Ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE:To enable cross distribution of power to be performed simplifying the constitution, by utilizing plural maps, in which electric conduction and non-conduction in every predetermined crank angle for each ignition coil are respectively and separately set in every predetermined operative condition of an engine, and controlling the electric conduction to each ignition coil. CONSTITUTION:Electric conduction and non-conduction in every predetermined crank angle for an ignition coil, provided in each cylinder, are respectively and separately set in every predetermined operative condition of an engine in plural maps, and a conduction control timing memory means A, which stores in memory the plural maps, is provided. While a map selecting means B, which selects an applicable map from the memory means A in accordance with the engine operative condition, is provided. Further a crank angle detecting means C and an electric conduction cutoff timing setting means D, which sets the electric conduction cutoff timing to each ignition coil on the basis of the engine operative condition, are provided. And it is constituted that the electric conduction to each ignition coil is respectively and separately controlled by an electrification control means E on the basis of the selected map, crank angle of engine and the set electric conduction cutoff timing which are described in the above.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an ignition system for an internal combustion engine, and more specifically, an ignition system that includes an ignition coil for each cylinder and a spark plug connected to the secondary side of the ignition coil. Regarding.

<Conventional technology> A conventional general ignition system has only one ignition coil, and by cutting off the current to the primary side of the ignition coil, the high voltage generated on the secondary side is transmitted through a distributor. Power is distributed to the spark plugs of each cylinder.

<Problems to be Solved by the Invention> Incidentally, in order to ensure a high voltage on the secondary side to obtain sufficient ignition energy, it is necessary to increase the energization time to the primary side of the ignition coil to a certain extent or more. .

However, when generating ignition signals for all cylinders with one ignition coil, for example in a 4-stroke engine,
Since it is necessary to energize the primary side of the ignition coil intermittently several times during the two revolutions of the engine, sufficient energization time can be secured when the engine is running at low speeds, but when the engine is running at high speeds, the ignition signal is As the interval between occurrences becomes shorter, it is necessary to shorten the energization time.
This has caused a problem in that ignition energy decreases and combustion tends to become unstable.

Further, when a distributor is used, electric energy is consumed, and since the wiring from the secondary side of the ignition coil to each spark plug becomes long, the electric energy loss during this period also increases.

For this reason, some systems have been designed to reduce electrical energy consumption and increase ignition energy by providing an ignition coil for each cylinder, omitting the distributor, and shortening the wiring between the ignition coil and spark plug. . However, even in this case, if the ignition signal is intermittently output from one output port of the microcomputer to each cylinder and distributed to each cylinder via a multiplexer, multiple cylinders will be ignited at the same time. Output signal (cross power distribution)
It is impossible to ensure sufficient energization time at high rotation speeds. For this reason, there is a system in which each cylinder is provided with an ignition signal output port to enable independent energization time control, that is, cross power distribution.
023894 etc.), however, there was a problem in that the circuit configuration became complicated.

The present invention was made in view of the above problems, and provides an ignition device in which each cylinder is provided with an ignition coil.
The purpose is to enable cross power distribution without complicating the device circuit.

(Means for Solving the Problems) Therefore, in the present invention, as shown in FIG. The device stores a crank angle detection means for detecting the crank angle of the engine, and a plurality of knobs each independently setting energization/de-energization for each of the ignition coils at each predetermined crank angle for each predetermined operating state of the engine. energization control timing storage means, energization cutoff timing setting means for setting the energization cutoff timing to each of the ignition coils based on the engine operating state, and energization control timing storage means for setting the energization control timing storage means to the corresponding engine based on the engine operating state. A crank angle of the engine detected by a map selection means for selecting a map in an operating state and a crank angle detection means.

energization control means for independently controlling energization to each ignition coil based on the energization cutoff timing set by the energization cutoff timing setting means and the map selected from the energization control timing storage means by the map selection means; The ignition system for an internal combustion engine is constructed using the same technology.

<Operation> According to the ignition device having such a configuration, energization/de-energization of each ignition coil is independently memorized for each predetermined crank angle depending on the engine operating state such as the engine rotational speed. At this time, at high speeds, it is necessary to perform so-called cross power distribution in order to secure the energization time, but as mentioned above, the energization and de-energization of each ignition coil are stored independently, so cross power distribution is not possible. There is no problem in keeping the memory in such a state. Therefore, if the energization cutoff timing, that is, the ignition timing is set, and the energization is controlled independently for each ignition coil based on the memory of energization/de-energization for each ignition coil, cross power distribution at high speeds can be implemented. It is something that

In addition, since this type of loss power distribution is performed by outputting ignition signals corresponding to each ignition coil based on a map instead of the ignition signals that were conventionally distributed by a multiplexer, the circuit configuration becomes complicated. There's nothing to do.

<Example> An embodiment of the present invention will be described below based on the drawings.

FIG. 2 shows the hardware configuration of this embodiment. Here, ignition coils 1a to 1f are provided for each cylinder of a six-cylinder (#l to #6) internal combustion engine (not shown), and the primary side thereof is connected to power transistors 2a to 2f as energization control means.
The spark plugs 3a to 3f are connected to the secondary side.

Ignition signals are inputted to the bases of the power transistors 2a to 2f independently from each output terminal of a memory 6 serving as energization control timing storage means, thereby causing current to flow through the primary sides of the ignition coils 1a to 1f. When this current is cut off, the high voltage generated on the secondary side causes the spark plugs 3a to
Ignition is performed by discharging between the 3F electrodes.

The memory 6 stores a plurality of maps in which each of the ignition coils la to lf is set to be energized or de-energized for each of a plurality of engine operating states divided by the engine rotational speed N. As shown in FIGS. 4 and 5, this map includes each cylinder (#1 to #6), that is, each ignition coil 1a-
rOJ to determine whether to energize or not energize each 1f.
orrl", that is, it is stored in binary notation. Here, "0"
indicates that the power is not energized, and "1" indicates that the power is energized. It's Nishide. For example, in the map shown in FIG. 4, the address (
A D D R) 0000 energized and address 00
At 01, the energization is cut off, and when the energization is cut off, the #1 cylinder is ignited.

In this embodiment, on the map, the ignition timing in each cylinder #1 to #6 changes from "1" to "0" at a predetermined address so that the ignition timing for each cylinder #1 to #6 is set at a predetermined address.
The cylinder is the 2nd address (2) of each map, the 92nd cylinder is the 10th (10), the #3 cylinder is the 6th (6), and the #4
Cylinder is the 12th (12), #5 cylinder is the 4th (4),
For #6 cylinder, the 8th (8) is the ignition timing. Therefore, if "1" continues in the address before the ignition timing of each cylinder #1 to #6, the energization time will be set longer.

Addresses of multiple maps as described above can be obtained by using an address counter (ADDRC0UNTO) as a map selection means.
R) 5, and an ignition signal corresponding to rOJorrlJ at the specified address is input to the paces of power transistors 2a to 2f.

The ignition reference signal is input from the CPU 4 to the CountUp circuit 5a and the Re5et circuit 5b of the address counter 5, and the engine rotational speed N is input from the CPU 4 to the 0ffset circuit 5C. The CPU 4 receives a reference signal REF every 120' from a crank angle sensor (not shown) as a crank angle detecting means (it includes a cylinder discrimination signal, and since this embodiment is a 6-cylinder internal combustion engine, it is every 1200'). 1 for a 4-cylinder internal combustion engine
The reference signal R
The engine rotational speed N can be determined by measuring the period of EF or by counting the number of inputs of position signal PO8 per unit time.
is measured, and the engine rotational speed N as a result of this measurement is output to the 0ffset circuit 5C of the address counter 5.

Further, the CPU 4 as a deenergization timing setting means determines the ignition timing (ftJ1 when de-energizing the ignition coils 1a to 1f ).

The ROM in the CPUd has previously stored data on ignition timing (expressed as a crank angle) in correspondence with the engine speed N and basic fuel injection ff1Tp, and from this data, the ignition timing in the relevant operating state is stored. The timing is searched and set based on the basic fuel injection amount 'rp and the engine rotational speed N.

When CPU4 sets the ignition timing in this way,
The position signal PO8 is counted from a crank angle that is a predetermined angle before the reference signal REF for each 0°, and the set ignition timing (the energization cutoff timing of the ignition coils la to 1f) is measured. Here, as shown in FIG. 3, the CPU 4 outputs an ignition reference signal with a pulse width equivalent to a crank angle of 60'' that falls at the measured ignition timing. That is, the fall of this ignition reference signal is This corresponds to the ignition timings 1 to #6, and the CountUp circuit 5a inputting this ignition reference signal counts addresses in synchronization with the rise and fall of the pulse signal and specifies a predetermined address on the map. .

In the map stored in the memory 6, the ignition timing addresses for each cylinder #1 to #6 are determined as described above (even numbered addresses, #1 (2)
1→#5 (4)→#3 (6)-96(8)→#
2αω→#40) Therefore, if the rise of the ignition reference signal is counted as an odd number and the fall of the ignition reference signal is counted as an even number, the rise and fall of the ignition reference signal can be counted and this count can be calculated. By specifying the address in the memory 6 in synchronization with the ignition timing, each ignition coil 1a
~If is cut off. Thermal theory, the ignition cylinder in the map and the ignition cylinder in the ignition reference signal are synchronized based on cylinder discrimination based on the reference signal REF output from the crank angle sensor.

To explain specifically, the ignition timing falls at the ignition timing set based on the basic fuel injection ff1Tp and the engine rotation speed N,
However, at the beginning of engine operation, as shown in Figure 3, the ignition reference signal whose first fall is synchronized with the ignition timing of the #1 cylinder is set to C.
When outputted to the countup circuit 5a, the countup circuit 5a specifies the first address of the map selected according to the engine rotational speed N in synchronization with the first rise of the ignition reference signal.

Therefore, for example, when a map for high engine speeds as shown in FIG. A high level signal (point signal) is output to the set power transistor 2a for the #1 cylinder and the power transistor 2e for the #5 cylinder. The next first fall (2) is the ignition timing of the #1 cylinder on the map, and this first fall (2) is the ignition timing of the #1 cylinder on the map.
) is synchronized with the ignition timing set based on the engine operating state, so by specifying address 0011 when counting the falling edge (2), the ignition in #1 cylinder will be ignited according to the engine operating state. It will be done. That is, when the address 0011 is specified, since the #1 cylinder is "0", the output of the high level signal to the power transistor 2a for the #1 cylinder is cut off, and the ignition coil 1a is
(at address 0010, the ignition coil 1a is energized).

On the other hand, at address 0011, #5 cylinder is at address 0.
Since it continues to be "1" from 010, the output of the high level signal to the power transistor 2e for the #5 cylinder continues. That is, the output of the high level signal to the power transistor 2e for cylinder #5 is at address 0.
The ignition continues from 010 to address 0012, and is cut off at address 0013 to ignite cylinder #5.

In this way, by counting the addresses in synchronization with the rise and fall of the pulse of the ignition reference signal, the energized crank angle shown in the map stored in the memory 6 in advance (in this embodiment, the "1" indicates that the current is energized corresponding to a crank angle of 60 degrees), the energization of the ignition coils 1a to 1f is controlled, and the setting of the energizing crank angle is for each cylinder #1 to #6.
can be set independently (by continuously setting "1" to each address, the energization time for the ignition coils 1a-1f can be set longer), so "1" can be set for multiple cylinders at the same address. Once the settings are made, so-called cross power distribution will occur, and by setting the map in advance to cross power distribution as described above, it is possible to ensure sufficient energization time even at high speeds. It is what it is.

However, according to this embodiment, it is only necessary to provide an address counter 5 and a memory 6 instead of the multiplexer that distributes the ignition signal to the ignition coils 1a to 1f of each cylinder, and cross power distribution is possible by adding the hardware configuration. The circuit configuration can be simplified compared to the case where

Incidentally, the Re5et circuit 5b is for returning to the first address of the map when the address goes around.
When the applied map is changed due to a change in the engine rotational speed N, the 0ffset circuit 5c specifies the address of the changed map according to the address order with respect to the reference signal.

<Effects of the Invention> As explained above, according to the present invention, in an ignition device including an ignition coil and a spark plug for each cylinder, it is possible to avoid complicating the circuit configuration of the device (cross power distribution between each ignition coil is not required). This has the effect that a sufficient current application time can be obtained during high rotation.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the present invention, Fig. 2 is a system diagram showing an embodiment of the present invention, Fig. 3 is a diagram showing an ignition reference signal in the above embodiment, and Fig. 4 is a low rotation speed diagram in the above embodiment. FIG. 5 is a time chart showing the ignition signal for each cylinder corresponding to the high-speed map in the same embodiment. 1a-1f...Ignition coil 2a-2f...Power transistor 33-3f...Spark plug 4...
・CPU 5... Address counter 5 a -
CountUp circuit 5 b...Reset circuit 5c...Memory for 0ffset circuit 6 Figure 3 Side 1 u5 n3 5 s2
#4 Figure 4

Claims (1)

[Claims] An ignition system for an internal combustion engine comprising an ignition coil for each cylinder and a spark plug connected to the secondary side of the ignition coil, comprising: a crank angle detection means for detecting a crank angle of the engine; energization control timing storage means storing a plurality of maps independently setting energization/de-energization for each of the ignition coils at each predetermined crank angle; and energization control timing storage means for cutting off the energization to each of the ignition coils based on the operating state of the engine. a map selection means for selecting a map for a corresponding engine operating state from the energization control timing storage means based on the engine operating state; An ignition device for an internal combustion engine, comprising: energization control means that independently controls energization to each ignition coil based on a cutoff timing and a selected map.