JPH0338436Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control unit for fuel injection amount control provided with an air regulator control function.

The air regulator is used to warm up the engine smoothly, and as shown in Figure 1, the air regulator
An air regulator 4 is interposed in the bypass passage 3 that bypasses the throttle valve 2 of the engine, and immediately after the engine is started, that is, immediately after the heater 5 starts to be energized, the bimetal temperature is low and the air flow rate in the bypass passage 3 is increased in the fully open state to maintain idling rotation. Make it expensive. Then, as the time for energizing the heater 5 passes, the bimetal temperature increases, and the bypass passage 3 is gradually closed and the air flow rate is controlled to be reduced. That is, it has air flow control characteristics as shown in FIG.

By the way, in the conventional electronically controlled fuel injection internal combustion engine equipped with this heater energization control type air regulator, the heater energization control of the air regulator 4 is not performed within the control unit for controlling the fuel injection amount, and the oil plate is operated as shown in FIG. The running or stopping state of the engine is determined by the shift switch and alternator signals, and the heater 5 is energized by turning on the air regulator relay 6 during operation.

Therefore, a relay and wiring dedicated to the air regulator were required, resulting in high cost. In FIG. 1, 7 is an air flow meter, and 8 is an engine body.

The present invention was developed in view of the above-mentioned circumstances, and it incorporates the function of duty-controlling the amount of electricity supplied to the heater of the air regulator in accordance with the width of the fuel injection pulse calculated by the control unit for controlling the amount of fuel injection into the control unit for controlling the amount of fuel injection. The purpose of this additional configuration is to solve the conventional problems and to perform heater energization control appropriate to the load condition of the engine.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 3 shows an embodiment of the control unit according to the present invention.

In the figure, a fuel injection amount control control unit 11 has a built-in injection pulse width calculation section 12 that calculates the fuel injection pulse width, and an air amount signal,
The fuel injection pulse width is calculated based on engine rotation signals synchronized with engine rotation used for fuel injection control such as water temperature, intake air temperature signals, switch signals, ignition signals, etc., and the width of this pulse signal is amplified by the width increaser 13. After that,
The fuel injection valve 14 is driven and controlled by this amplified pulse signal.

Furthermore, inside this control unit 11,
It corresponds to heater energization control means that inputs the injection pulse signal output from the injection pulse width calculation section 12 and duty-controls a width increasing section 16 as a switching means for opening and closing a heater energization circuit, which will be described later, based on the pulse signal. Pulse width extension section 15
(The expansion rate is approximately 10). This pulse width expanding section 15 is for expanding the fuel injection pulse width as shown in FIG. 4b, since the duty of the fuel injection pulse is small as shown in FIG. . The collector of the widening portion 16 is connected to the positive electrode of the battery 19 via the heater 5 of the air regulator 4,
It includes a transistor 17 whose emitter is grounded and which turns on and off based on the duty of the expanded fuel injection pulse signal output from the pulse width expansion section 15. 18 is a fixed resistor.

Next, the action will be explained.

When the engine is warmed up, the injection pulse width calculation section 12 calculates and outputs an injection pulse width corresponding to the engine load at that time based on each input signal. The pulse width expansion section 15 expands the pulse signal output from the injection pulse width calculation section 12 and outputs the expanded pulse signal to the width expansion section 16 . In the width increasing section 16, the transistor 17 is turned on and off according to the duty of the output pulse signal from the pulse expanding section 15, and the amount of current flowing from the battery 19 to the heater 5 of the air regulator 4 is controlled in accordance with the duty. .

By incorporating the air regulator control function into the fuel injection control control unit 11 in this way, the conventional air regulator control relays, wiring, etc. are no longer necessary, and costs can be reduced.

Further, according to this configuration, the injection pulse width differs depending on the engine load state, and the amount of electricity supplied to the heater of the air regulator 4 can be controlled to match the load state during warm-up, and the air flow rate can be controlled. accuracy can be increased.

That is, in the past, as shown in FIG. 2, the air flow rate was determined only by the heater energization time. For this reason, the warm-up of the idle duration (during low load)
If the engine warms up slowly, such as when the engine warms up slowly, the air flow rate may drop to zero despite insufficient warming, or if the engine warms up quickly, such as when warming up while driving (at high load). There were problems such as the air flow rate sometimes not reaching zero even after warming up.

However, according to this embodiment, when the engine warms up slowly at low load, the duty of the injection pulse width is small, so the amount of current supplied to the heater 5 of the air regulator 4 per unit time is also small, as shown in FIG. 5A. Similarly, the decrease in air flow rate also becomes slower.

On the other hand, when the engine is warmed up quickly and under high load, the duty of the injection pulse width is larger than when the load is low, so the amount of electricity per unit time to the heater 5 of the air regulator 4 increases, and the air flow rate increases as shown in Figure 5B. also decreases faster.

In this way, this embodiment has the effect of being able to obtain air flow characteristics commensurate with the warming-up speed of the engine.

As explained above, according to the present invention, since the heater energization control of the air regulator is performed within the control unit for controlling the fuel injection amount,
Conventional air regulator control relays and wiring are unnecessary, reducing costs. In addition, since the heater energization is duty-controlled using fuel injection pulses, the air flow rate can be controlled by the air regulator according to the load condition during engine warm-up, improving the accuracy of air flow control. .

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing a conventional air regulator control device, Fig. 2 is a diagram showing air flow control characteristics of the same air regulator, Fig. 3 is a block diagram showing an embodiment of the present invention, and Fig. 4 a shows an injection Figure 5 is a diagram showing the air flow rate control characteristics of the air regulator during warm-up of the engine in the same example as above; Time and B indicate the respective cases under high load. 2...Throttle valve, 3...Bypass passage, 4...Air regulator, 5...Heater, 1
DESCRIPTION OF SYMBOLS 1... Control unit, 12... Injection pulse width calculation section, 15... Pulse width expansion section, 16...
Width part.

Claims (1)

[Scope of utility model registration request] A control unit for controlling the fuel injection amount, and a heater that is installed in the bypass passage of the throttle valve and operates to close the valve as the heater is energized, gradually closing the bypass passage and controlling the air flow rate during warm-up. In an electronically controlled fuel injection internal combustion engine equipped with an energization control type air regulator, switching means for opening and closing the energization circuit of the air regulator and a fuel injection pulse signal outputted from a fuel injection pulse width calculation means in the control unit are provided. 1. A control unit for fuel injection amount control with an air regulator control function, further comprising heater energization control means for duty-controlling the opening and closing of the switching means.