JPS63297770A - Ignition device for engine - Google Patents

Abstract

PURPOSE:To maximize a fuel consumption effect and an output effect by detecting the load current of an alternator by a load current value detecting means and controlling an ignition energy varying means so that the increasing quantity of an ignition energy can be varied in accordance with the detected load current value. CONSTITUTION:When the value of the load current of an alternator 4 is small, the voltage drop V of a resistance R is less than a defined value V0, a DC-DC converter 10 is controlled by a voltage control circuit 18, and the ignition energy of ignition plugs 1a-1d is increased, resulting in a favorable combustion of a mixture to improve fuel consumption. On the other hand, when the value of the load current of the alternator 4 becomes large, the power loss of an engine is increased. In this case, however, since the increased amount of the ignition energy of the ignition plugs 1a-1d is controlled to be small or zero by the voltage control circuit 18, the deterioration of fuel consumption can be prevented. Thereby, the combustion property of the mixture can be made favorable by the increase in ignition energy while suppressing increase in the power loss of the engine as much as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ignition device for an engine, and more specifically, it improves the combustibility of a mixture by increasing the amount of ignition energy.
This article relates to improvements aimed at improving fuel efficiency.

(Prior Art) Conventionally, as an ignition system for this type of engine, for example, as disclosed in Japanese Unexamined Patent Publication No. 58-13161, the discharge energy of the spark plug is increased by increasing the primary current value of the ignition coil. It is known that the combustion engine is equipped with an ignition energy variable means that increases the discharge energy to improve the combustibility of the air-fuel mixture in the combustion chamber, thereby improving fuel efficiency.

(Problems to be Solved by the Invention) By the way, a vehicle is equipped with an on-board battery as a power supply source as well as an alternator that is driven and connected to the engine, and when the ignition energy increases as described above, the primary ignition coil As the current value increases, the load current value of the alternator also increases, and the power loss of the engine increases accordingly. Moreover, when the load current value of this alternator is large, that is, when an electrical load such as an in-vehicle electrical component is operated, the internal resistance increases due to the heat generation of the armature coil, and the resistance loss increases synergistically. The power loss of the engine further increases, and its power loss characteristics increase in a quadratic manner as the load current of the alternator increases.

Therefore, when the alternator's load current value is large, even if the ignition energy is increased, the resulting improvement in fuel efficiency is outweighed by the reduction in fuel efficiency due to increased engine power loss. On the contrary, this will lead to a decrease in fuel efficiency.

The present invention has been made in view of the above, and its purpose is to increase the ignition energy while suppressing the power loss of the engine by adjusting the increase in the ignition energy according to the load current value of the alternator. The goal is to effectively improve fuel efficiency and maximize fuel efficiency and output effects.

(Means for solving the problem) In order to achieve the above object, the solving means of the present invention is as follows.
As shown in the figure, an ignition system for an engine is assumed to be provided with an ignition energy variable means 10 that variably adjusts the ignition energy of spark plugs 1a to 1d. Load current value detection means 16 detects the load current value of the alternator 4, and the alternator 4 detected by the load current value detection means 16
The ignition energy control means 25 is provided for controlling the ignition energy variable means 1o so as to vary the amount of increase in ignition energy according to the load current value.

(Function) With the above configuration, in the present invention, when the load current value of the alternator 4 is a small value, the power loss of the engine is relatively small, and in this situation, the ignition energy variable means 1o adjusts the ignition energy The operation is controlled by the control means 25, and the ignition energy of the spark plugs 18 to 1d is greatly increased, so that as the ignition energy increases, the combustion state of the air-fuel mixture becomes even better, and fuel efficiency improves.

On the other hand, when the load current value of alternator 4 is large,
The power loss of the engine is large, and if the ignition energy is further increased in this situation, the increase in power loss will become significant and will exceed the improvement in fuel efficiency due to the increase in ignition energy, resulting in a decrease in fuel efficiency. It turns out. However, in this case, the ignition energy control means 25 controls the increase in the ignition energy of the spark plugs 1a to 1d to be small or to zero, thereby preventing the fuel consumption from worsening. Therefore, while suppressing the increase in engine power loss as much as possible, the ignition energy is increased to improve the combustibility of the mixture, so that the improvement in the combustibility of the mixture exceeds the increase in engine power loss. As a result, fuel efficiency can be effectively improved, and the effects of improving fuel efficiency and output can be maximized.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall configuration of the engine ignition system according to the present invention, where 1a to 1d are spark plugs arranged in each cylinder of a four-cylinder engine, and 2 is a distributor that distributes power to each of the point hole plugs 1a to 1d. be.

Further, 3 is an in-vehicle battery as a power supply source to each of the spark plugs 1a to 1d, and 4 is an alternator drivingly connected to the engine. Armature coil 4b and both coils 4
The rectifier 4c rectifies the three-phase current generated by the relative rotation of the motors a and 4b, and the rectifier 4c supplies electric power together with the vehicle battery 3.

Furthermore, 5 is an ignition coil, and the ignition coil 5 is
One end of the next coil 5a is connected to the ignition switch 7.
It is connected to the on-board battery 3 and the rectifier 4c of the alternator 4 through the in-vehicle battery 3 and the rectifier 4c of the alternator 4 to be able to supply current, and the other end is connected to a control transistor T', whose base B is connected to the rectifier 4c of the alternator 4. An ignition unit 8 is connected to turn on the control transistor Tr at the ignition timing of the air-fuel mixture.On the other hand, the distributor 2 is connected to one end of the secondary coil 5b, and the distributor 2 is connected to the other end of the secondary coil 5b.
A C-DC converter 10 is connected.

The DC-DC converter 10 transforms and adjusts the secondary voltage value generated in the secondary coil 5b, and converts it into each spark plug 1a to 1.
It functions as an ignition energy variable means for adjusting the ignition energy (discharge energy) at d.

In addition, 12 is an electric load such as an on-vehicle cooler, and the electric load 12 is connected to the on-board battery 3 and alternator 4 in parallel with the ignition coil 5 via a cooler switch 13. When the load is activated and the above D
When the C-DC converter 10 increases the secondary current value of the ignition coil 5, the load current value of the alternator 4 also increases accordingly.

Here, in the spark plugs 1a to 1d, as the ignition energy increases, the combustibility of the air-fuel mixture improves as the ignition energy increases, so that the fuel efficiency also increases proportionally. On the other hand, as shown in the same figure (b), the alternator 4
When the load current value increases, the driving torque of the engine to the alternator 4 initially increases proportionally, but as the load current increases, the internal resistance of the armature coil 4b increases, and the heat loss increases. As the value increases, it gradually increases in a quadratic curve. As a result, the power loss of the engine also increases in a quadratic manner, as shown in FIG. In particular, when the alternator 4 is at high temperature (hot state indicated by the broken line), the efficiency of electrical conversion due to heat generation decreases. ) has the characteristic that the curvature of the quadratic curve is much larger.

In FIG. 2 above, a resistor R with a minute resistance value is interposed in the current supply wiring 15 from the alternator 4, and when the load current of the alternator 4 changes, the resistor R changes accordingly. The load current value detecting means 16 is configured to detect the load current value of the alternator 4 by changing the voltage drop of the alternator 4.

The voltage drop signal of the resistor R is input to a voltage control circuit 18 having a CPU, etc. inside, and the voltage control circuit 18 includes a rotation speed sensor 19 that detects the engine rotation speed, and an engine load based on intake negative pressure, etc. A load sensor 20 is connected to detect the DC voltage.
- Controls the operation of the DC converter 10, and controls the spark plug 1a.
The ignition energy is controlled at ~1d. In addition, in FIG. 2, 21 is a voltage regulator that adjusts the voltage value applied to the field coil 4a of the alternator 4.

Next, the operation control of the DC-DC converter 10 by the voltage control circuit 18, that is, the adjustment control of the ignition energy of the spark plugs 1a to 1d will be explained based on the control flow shown in FIG.

After starting, input the engine speed N from the rotation speed sensor 19, the engine load TP from the load sensor 20, and the voltage drop V across the resistor R in step S1, and then input the voltage drop across the resistor R in step S2. v1, that is, the load current value of the alternator 4, is determined from the fuel efficiency characteristics and power loss characteristics according to the engine speed shown in FIGS. 3(a) and 3(c) above. Compare the magnitude with the voltage value Vo (different depending on when the alternator 4 is hot or cold) corresponding to the load current value at which the maximum effect of improving fuel efficiency can be obtained, and if v<v□, YES, that is, the fuel efficiency is Step S3 only if it is possible to obtain
and S4, the engine speed N and engine load TP, respectively.
is compared with the boundary values No, 'rpo of a predetermined operating range in which the ignition energy is increased as shown in FIG. The H1gh voltage signal is applied to the DC-DC converter 10 to increase the secondary voltage of the ignition coil 5, thereby increasing and adjusting the ignition energy of each spark plug 1a to 1d. On the other hand, N≧No or TP≧TPo which is not within the specified operating range
In this case, in step S6, the DC-DC converter 10
A Low voltage signal is output to the ignition coil 5 to return the secondary voltage of the ignition coil 5 to the original value, and the ignition energy of each of the ignition plugs 1a to 1d is set to a normal value. In this case, since the combustion speed of the air-fuel mixture becomes slower and the minimum ignition advance value (MBT) becomes advanced, the ignition timing is also advanced by a certain amount from the basic value.

Also, in step S2 above, vkuvo.

If the increase in ignition energy causes a decrease in fuel efficiency, the process proceeds to step S6, where the secondary voltage of the ignition coil 5 is returned to its original value and the ignition energy of each spark plug 1a to 1d is reduced, even if the fuel consumption is within the predetermined operating range. Set as normal value.

Therefore, steps S2 and S of the control flow in FIG.
s s S6 detects the load current value of the alternator 4 detected by the load current value detection means 16 (voltage drop V at the resistor R).
), if the voltage drop V is less than a predetermined value Vo (v<v□) at which the fuel efficiency improvement effect is obtained, the ignition coil 5
The secondary voltage value of the ignition coil 5 is increased to make the amount of increase in ignition energy a large positive value, and in the case of V≧VO, the secondary voltage value of the ignition coil 5 is set to the normal value and the amount of increase in ignition energy is set to zero value. The ignition energy control means 25 is configured to control the operation of the DC-DC converter 10 so as to achieve the following.

Therefore, in the embodiment described above, in the predetermined operating range shown in FIG. Since the secondary voltage value is controlled to be high and the ignition energy of the spark plugs 1a to -1d increases, the combustibility of the air-fuel mixture is further improved and fuel efficiency is improved.

Now, if the load current value of alternator 4 is small, the resistance R
The voltage drop V is less than the predetermined value Vo (v<v□),
The ignition energy is increased and controlled as described above. In this case, the driving torque to the alternator 4 is small as shown in Figure 3 (B), and the power loss of the engine is small as shown in Figure 3 (C), so the effect of improving fuel efficiency due to the increase in ignition energy is Large and effective.

On the other hand, when the load current value of the alternator 4 is large, the voltage drop V across the resistor R is equal to or greater than the predetermined value V (V≧Vo).
In this case, the power loss of the engine tends to increase rapidly, corresponding to points with high curvature on the loss characteristic curve in FIG. 3(c). In particular, when the alternator is hot, the rising curvature of the power loss becomes larger than when the alternator is cold, and the power loss increases significantly because the electric conversion efficiency decreases due to heat generation.

Therefore, when the ignition energy increases, the power loss of the engine due to the increase in the load current of the alternator 4 is greater than the resulting improvement in fuel efficiency, and the fuel efficiency tends to deteriorate. However, in this case, the voltage control circuit 18 sends Lo to the DC-DC converter 10.
Since the w voltage signal is output, the secondary voltage value of the ignition coil 5 is returned to the normal value, and control to increase the ignition energy of the spark plugs 1a to 1d is not performed, fuel efficiency does not deteriorate.

Therefore, increasing control of ignition energy is prohibited in situations that would lead to a significant increase in power loss, and the effect of improving fuel efficiency by improving the combustibility of the air-fuel mixture can be maximized.

In the above embodiment, the ignition energy was increased in a 0N10FF manner in the predetermined operating range shown in FIG. may be controlled continuously.

(Effects of the Invention) As explained above, according to the present invention, when increasing the ignition energy to increase the combustibility of the air-fuel mixture and improving fuel efficiency, the increase in the ignition energy of the spark plug is applied to the load on the alternator. Since it is controlled according to the current value, the combustibility of the mixture can be further increased without causing a significant increase in the power loss of the engine, and the improvement in the combustibility of the mixture can always be used to increase the power loss of the engine. It can be made larger than the previous model, maximizing the effect of improving fuel efficiency and output.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. Figures 2 to 5 show embodiments of the present invention, Figure 2 is an electric circuit diagram showing the overall schematic configuration, and Figures 3 (A) to (C).
are diagrams showing fuel efficiency characteristics with respect to ignition energy, required driving torque characteristics of the alternator with respect to alternator load current, and engine power loss characteristics with respect to alternator load current, respectively; FIG. 4 is a flow chart diagram showing the operation of the voltage control circuit; The figure shows a predetermined operating range in which ignition energy increase control is performed. 1a to 1d...Spark plug, 4...Alternator,
5... Ignition coil, 10... DC-DC converter, R... Resistor, 16... Load current value detection means, 18
... Voltage control circuit, 25... Ignition energy control means. Figure 1 Figure 4

Claims (1)

[Claims] (1) An ignition device for an engine equipped with a variable ignition energy means for variably adjusting the ignition energy of a spark plug, comprising a load current value detection means for detecting a load current value of an alternator, and a load current value detected by the load current value detection means. and ignition energy control means for controlling the ignition energy variable means so as to vary the amount of increase in ignition energy according to the load current value of the alternator.