JPH02238141A - Idle rotation frequency control device of engine - Google Patents

Abstract

PURPOSE:To decide the adequate control amount constantly and to make it possible to control the engine rotation frequency accurately by deciding the control amount to control the engine rotation frequency depending on the exciting period of a generator, and correcting the control amount responding to the temperature of the generator. CONSTITUTION:A generator 1 driven by an engine is composed of a Y-connected armature winding 10 an diodes 12-14 to rectify the threephase current of a field coil 11 and the armature winding 10. In this case, a switching device 2 to control the exciting period of the field coil 11 to make the battery voltage at a specific voltage and to control the exciting current is provided. Moreover, a control unit 5 to control the opening of an electromagnetic valve 7 arranged in a bypass passage 8 of a throttle valve 9 is provided, which detects the exciting period of the field coil 11 between specific crank angles. And the system is composed to correct the control amount determined depending on the exciting period, and the opening of the electromagnetic valve 7 is controlled by the control amount after the correction.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an engine idle speed control device,
In particular, it relates to correcting the amount of intake air supplied to the engine according to the amount of electrical load. [Prior Art] Conventional idle speed control devices control the amount of intake air supplied to the engine according to the deviation between the target idle speed and the actual engine speed, and adjust the engine speed to the target speed. It is being maintained. [Problems to be Solved by the Invention] In the conventional device described above, when an electrical load that consumes a large amount of electricity (headlights, electric radiator fan, etc.) is used, the generator that supplies electricity to the electrical load is activated. The load on the engine increases and the engine speed decreases. This decrease in engine speed will eventually return to the target speed through the control operation described above, but because the control response is slow, the engine may stall depending on the magnitude of the electrical load. Further, for example, in Japanese Patent Application Laid-Open No. 58-197449, an electric load switch corresponding to a plurality of electric loads is provided,
It has been proposed to correct the intake air amount by detecting the on/off status of this electrical load switch, but this would require switches and input circuits corresponding to the number of electrical loads, which would complicate the scale of the control device. Ta. Therefore, for example,
No. 9-5855 provides an excitation period detection means for detecting an excitation period of a switching means for controlling the field current of a generator, and controls the engine rotation speed by a control amount determined based on the output of this detection means, Efforts were made to eliminate engine stalls and control response delays.

However, the above excitation period changes depending on the temperature of the generator, and even if the amount of electricity is the same, the higher the temperature of the generator, the longer the above excitation period becomes. Therefore, the control amount determined based on the above excitation period becomes larger than the required control amount, causing an increase in engine speed.
Similarly, even if the electrical load is the same, the lower the temperature of the generator, the shorter the excitation period, and the control amount determined based on the excitation period will be smaller than the required control amount, resulting in a decrease in engine speed. This will invite This invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain an engine idle speed control device that can always accurately control the engine speed. [Means for Solving the Problems] An engine idle speed control device according to the present invention includes:
Temperature detection means that directly or indirectly detects the temperature of the generator, and a control amount that controls the engine rotation speed are determined based on the excitation period of the generator, and this control amount is used to generate electricity. It is equipped with a correction means that corrects according to the temperature. [Operation] In this invention, the control amount for controlling the engine speed is determined based on the excitation period of the generator, and this control amount is corrected according to the generator temperature. [Examples] Examples of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of the engine idle speed control device according to this embodiment, where 1 is a generator, 2 is a field coil 1
1 is a switching means for controlling the excitation current, 3 is an engine switch, and 4 is an on-vehicle battery. The power generation lja1 is composed of a Y-connected armature winding 10, a field coil 11, and diodes 12 to 14 that rectify the Sanwa AC output of the armature winding vA10. Switching means 2
is a voltage detection circuit 21 that detects the voltage value of the battery 4;
A semiconductor switching element 22 connected in series with the field coil 11 and turned on by the output of the voltage detection circuit 21 when the voltage of the battery 4 becomes lower than a predetermined value, and a field coil when the semiconductor switching element 22 becomes non-conductive. It consists of a diode 23 that commutates the excitation current flowing through the magnet 11. 5 is the field coil 11
An on/off signal (hereinafter referred to as an excitation signal) at the connection point between the semiconductor switching element 22 and the semiconductor switching element 22, a crank angle signal generated in synchronization with a predetermined crank angle of the engine, and the output of an engine cooling water temperature sensor (not shown) are input. , is a control unit that detects the excitation period of the field coil 11 (on period of the semiconductor switching element 22) and the engine cooling water temperature between predetermined cranks of the engine, and calculates the control amount according to the results. Reference numeral 6 denotes a solenoid that controls the opening and closing of the solenoid valve 7 according to a control amount that is the output of the control unit 5. The opening and closing of the solenoid valve 7 opens and closes the bypass passage 8 of the throttle valve 9 disposed in the intake passage 15 of the engine. It will happen. Next, the operation of the above configuration will be explained. The generator 1 is driven by the engine and charges the battery 4. The switching means 2 controls the excitation period of the field coil 11 and its excitation current so that the generated voltage of the generator 1 or the voltage of the battery 4 becomes a predetermined value. FIG. 2 shows details of the control unit 5, and FIG. 3 is a time chart showing its operation. 51 is a pulse A of a predetermined frequency (Fig. 3 (
Shown in C). ), and pulse A is input to a counter 53 via a resistor 52.

On the other hand, this input signal is masked by the transistor 54 only during the non-conducting period of the excitation signal shown in FIG.
Signal B shown in FIG. 3 (a) is input to the counter 53.
The counter 53 counts the signal B and sends the count value C shown in FIG. 3(e) to the CPU 55.The CPU 55 counts the signal B every time the crank angle signal shown in FIG. ) and outputs an initialization signal R (FIG. 3(f)) to initialize the counter 53. With the above operation, the CPU55
The count value CP read into becomes a value corresponding to the excitation period for each predetermined crank period. In addition, the CPU 5 reads engine cooling water temperature information,
The control amount for controlling the intake air amount is calculated from this engine cooling water temperature, count value C, and crank angle signal, and its operation will be explained using FIGS. 4 to 8. 4 and 5 are flowcharts showing the procedure for calculating the above-mentioned control amount. The flow shown in FIG. 5 is repeatedly executed according to the control program, and when a crank angle signal is generated during this execution, the flow shown in FIG. The process is canceled and the crank angle signal interrupt routine shown in FIG. 4 is executed. In step 351, the count value CP is read, and in step S52, the externally provided counter 53 is initialized. That is, the count value CP read into the CPU 55 is updated every crank angle signal. Next, in step S53, the crank angle signal
In step 354, the excitation period ratio D with respect to the crank angle signal period T is determined using the following equation. Here, K1 is a conversion coefficient for converting the excitation period rate D to a predetermined resolution. That is, the value meant by the excitation period rate D is a value corresponding to the excitation current flowing through the field coil 11. As described above, the crank angle signal interrupt routine shown in FIG. 4 is completed. Next, in the routine of FIG. 5, based on the excitation period rate D, first, in step S61, I is searched from the relationship diagram between the excitation period rate D and IE shown in FIG. This I is a state in which the engine is sufficiently warmed up, that is, the generator 1
The relationship between D It is the value corresponding to the output current of the generator l when the engine is sufficiently warmed up.
This is because D corresponds to the excitation current of the field coil 11, and I corresponds to the output current of the generator 1. That is, this is because the output of the generator 1 is given by the magnitude of the excitation current and the engine speed. Next, in step S62, from FIG. 7 showing the relationship between the generator output current I and the correction amount P, the standard correction amount P when the generator 1 is sufficiently warmed up is the generator output. The search is performed according to the current I. The data set in Figure 7 is the generator output when there is no electrical load. Set the correction amount to zero at the point , and set the correction amount corresponding to the increase in electrical load. In step S63, the engine cooling water temperature information W7 is read, and in step S64, a correction coefficient KET corresponding to the engine cooling water temperature Wa is searched from the cooling water temperature W and correction coefficient KtT table shown in FIG. In step S65, the correction amount P. Correction coefficient Kf? Multiply. Here, the correction coefficient K! T is a correction coefficient K.T corresponding to the engine cooling water temperature when the engine is sufficiently warmed up, that is, when the generator l is sufficiently warmed up. is set to 1.0, and when the cooling water temperature, that is, the temperature of the generator 1 is lower than this, the correction coefficient KtT is increased to compensate for the shortage of the correction amount P, and the engine cooling water temperature, that is, the temperature of the generator 1 is lower than this. In a state higher than the warm-up state, the correction amount is P! Decrease the correction coefficient KtT so that it does not become excessive. Thereby, the product Pta of the correction amount P and the correction coefficient K1 is set so as to always be a control amount corresponding to the electrical load, regardless of the temperature of the generator 1. In step S66, the basic control amount P of the intake air amount is set to PET,
are added, and the final control amount Pa is obtained. thus,
The amount of intake air increases according to PET. In the above embodiment, the correction coefficient Kt is searched based on the cooling water temperature, but the correction coefficient Kt is searched based on the engine intake air temperature.
A similar effect can be obtained by searching for T. Further, although the correction amount P is multiplied by the correction coefficient KET, the same effect can be obtained by multiplying the excitation period or excitation period rate D by the correction coefficient KET to obtain PTT.

〔Effect of the invention〕

As described above, according to the present invention, the control 'af# for controlling the engine speed is determined based on the excitation period of the generator,
Moreover, this control amount is corrected according to the generator temperature.
The excitation period, which changes depending on the generator temperature, is corrected correctly, and the control amount is therefore determined correctly, allowing the engine speed to be accurately controlled.

[Brief explanation of drawings]

1 and 2 are the overall configuration diagram and the configuration diagram of the control unit of this invention device, FIG. 3 is a time chart showing the operation of this invention device, and FIGS. 4 and 5 are diagrams showing the operation of this invention device. The flowcharts shown in FIGS. 6 to 8 are control characteristic diagrams stored in the control unit of the apparatus of the present invention. ■... Generator, 2... Switching means, 4...
Battery, 5...Control unit, 1l...Field coil. In addition,

Claims (1)

[Claims] A generator that is driven by an engine and charges a battery, and a switching device that controls the excitation current by controlling the excitation period of the field coil of the generator so that the generated voltage of the generator or the battery voltage becomes a predetermined voltage. , excitation period detection means for detecting the excitation period for each predetermined crank period of the engine, temperature detection means for directly or indirectly detecting the temperature of the generator, and a control amount for controlling the engine speed during the excitation period. What is claimed is: 1. An engine idle speed control device comprising a correction means for determining the control amount based on the temperature detection means and correcting the control amount according to the output of the temperature detection means.