JPS63219859A - Engine control device - Google Patents

Abstract

PURPOSE:To obtain an engine control device providing sufficient commonness and improving serviceability, by storing the conversion characteristic, necessary for fetching a data from a detecting means, in plural kinds of memories and enabling the necessary conversion characteristic to be selected. CONSTITUTION:When a detecting element in a detecting part 11 of a detector 1 for a flow amount of intake air to an engine uses, for instance, a platinum wire wound onto a ceramic bobbin, platinum wire arranged in an air passage etc., both the hot wires generate heating power serving for a function of a flow amount of air, obtaining an electric signal V. However, the conversion characteristic of said voltage V into the flow amount of air is different. And a discrimination signal S, output from a discrimination signal generating part 12, is discriminated by an air flow amount arithmetic part 24 through a discrimination control part 22. As the discrimination result, selecting specific one of the conversion characteristics stored in a memory 23, calculation based on the voltage V is performed, and an air flow amount Q is output. Accordingly, a control device is obtained with sufficient commonness and improved serviceability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic engine control device using a microcomputer, and particularly to a control device suitable for automobile engines.

[Conventional technology]

Detects physical quantities that represent the operating state of the engine, such as intake air flow rate and engine speed, and uses the signals to determine fuel efficiency,
Devices that optimally control exhaust gas have been increasingly adopted due to the need to save resources and prevent pollution, and the need for more precise control has led to the adoption of microcomputers. Note that related devices of this type include, for example, Japanese Patent Publication No. 49-48893;
There are publications such as No. 60-8329.

Incidentally, in an engine control device using such a microcomputer, it is necessary to use various detection means to convert the above-mentioned physical quantities, such as the intake air flow rate, into an electrical signal and incorporate it into the control. Regarding the conversion characteristics that express the relationship between the physical quantity to be detected and the electrical signal, the conversion characteristics of the detection means used for the detection, for example, an intake air flow rate sensor, are stored in advance in the memory of the microcomputer. The data necessary for control is taken in by the system.

[Problem that the invention seeks to solve]

However, although a system as complex as this prior art is highly accurate, it has problems in serviceability at the KWi field, especially in the event of a failure.

Therefore, one of the means for improving serviceability in the market is the ability to share parts. For example, intake air flow rate detectors are manufactured by several companies, and due to differences in basic technology and methods, the relationship between intake air flow rate and output voltage differs depending on the manufacturer. However, by allowing this to be shared by one engine control system, serviceability can be greatly improved.

However, the conventional technology does not take this kind of commonality into account, and there is a problem in that sufficient serviceability cannot be maintained.

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine control device that has sufficient commonality with respect to detection means and can greatly improve serviceability.

[Means for solving problems]

The above purpose is to store in memory in advance multiple types of conversion characteristics necessary for importing data from a detection means, so that the necessary conversion characteristics can be selected according to the detection means to be used. achieved.

[For production]

Even when changing the detection means, since the necessary conversion characteristics can be selected arbitrarily, the detection means can be easily changed, sufficient commonality is provided, and serviceability can be improved.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An engine control device according to the present invention will be explained in detail below using illustrated embodiments.

FIG. 1 shows one embodiment of the present invention. In the figure, 1 is a detector for the intake air flow rate of an engine, and 11 is an air flow rate detecting section in the detector 1. In FIG. Reference numeral 12 denotes an identification signal generator representing 10 types of detectors. 2 is a control section of the engine control device, which uses a microcomputer. 21 is an A/D converter for converting the analog signal output from the detector 1 into a digital signal, and 23 stores the relationship between the air flow rate of the detector 1 and the digitized detector output for several models. A memory 22 is an identification control circuit that converts the identification signal of the detector 1 into a digital signal, and 24 is an air flow rate calculation section.

Figure 2 shows an example of the basic configuration of an engine control system to which the present invention is applied. The control unit 2 is mainly determined by the output Q of the intake air flow rate detector 1 and the output N of the engine rotation speed detector 3. Calculate the ignition timing and fuel injection amount, add corrections to the engine cooling water temperature, etc., output the predetermined ignition timing and fuel injection amount to the ignition device 4 and fuel injection t5, and control the engine to the best condition. It is something.

Figure wc3 shows the details of the intake air flow rate detector 1, Figure 4 shows the detection element of the air flow rate detector 1, and Figure 5 shows the output when the detection element shown in Figure 4 is used. It shows the characteristics.

In Fig. 3, RH is a hot wire that is a temperature-sensitive resistor placed in the internal pressure of the intake air flow path B of the engine, RC is a temperature-sensitive resistance wire for compensating the intake air temperature, R1 and R2 are resistances, and Tr
is a transistor, and OP is a differential amplifier. This circuit is controlled by the differential amplifier OP to satisfy the relationship expressed by equation (1).

Therefore, the hot wire RH can be heated to a constant temperature with the ratio of R2 and R1. That is, the heating power of the hot wire RH becomes a function of the air flow iF, and an electric signal V can be obtained.

The hot wire RH, that is, the detection element is shown in Fig. 4 (
As shown in a), a ceramic bobbin BK with a platinum wire W wound around it, or as shown in FIG. As shown in the figure, a platinum film WP formed on the insulating film M is used, but these have advantages and disadvantages.For example, the one in (a) has strong mechanical strength but has poor responsiveness, and the one in (b) is the opposite of (a). On the other hand, the material shown in (c) is resistant to dirt.

However, these differ in the relationship between the voltage V and the air flow tQ, that is, the conversion characteristics, and these characteristics are approximately as shown in FIG. 5.

Returning to FIG. 3, the identification signal S output from the identification signal generating section 12 is a voltage signal determined by the division ratio of the resistors RX and RY.

On the other hand, in response to this, the identification control circuit 22 in the control unit 2
is as shown in FIG. 6, and the voltage obtained by dividing the power supply voltage Vs by resistors R1 and R2 and the identification signal S, which is the division ratio voltage of the resistors RX and RY from the detector l, are detected by a comparator. C
OM is compared, and the result is sent to the calculation unit 24. For example, when the detection unit 11 has the characteristic shown in FIG.
', and when the characteristic is (b), the signal ''']'' is output. Then, the arithmetic unit 24 reads this signal, and according to it, the memory 23
A specific one is selected from among several conversion characteristics 231 and 232 stored in the memory, a calculation is performed based on the voltage V, and the air flow rate Q is calculated and output.

Therefore, as the detector 1, (a) and (b) in FIG.
), each with different characteristics, exists, and even if any of them could be used in combination with the control unit 1, the control unit 2 The identification signal S determines which characteristic the detector 1 combined with the detector 1 has, and the corresponding conversion characteristic can be read out from the memory 23 and used.
According to this embodiment, no matter what kind of characteristics the detectors 1 are combined with, the control section 2 can always automatically respond and output the correct air flow rate Q, and the parts can be used in common. can give.

In addition, in the above embodiment, the case where there are two types of characteristics as the detector 1 was shown, but two or more comparators COM are used, and accordingly, three or more conversion characteristics are stored in the memory 23. (By this, it is possible to create an embodiment that targets three or more types of detectors.

Further, in the above embodiments, an intake air flow meter is used as the detector 1, but it goes without saying that the present invention is applicable to any object to be detected.

〔Effect of the invention〕

According to the present invention, it is possible to easily obtain an engine control system in which many types of detectors can be used in common, and furthermore, since changes in detectors are automatically dealt with, troubleshooting and maintenance in the market can be easily achieved. This has the effect of being able to easily and satisfactorily improve serviceability.

[Brief explanation of drawings]

@ Figure 1 is a block diagram showing an embodiment of an engine control device according to the present invention, Figure 2 is a block diagram showing an example of an engine control system to which the embodiment of the present invention is applied, and Figure 3 is a block diagram showing an example of an engine control system to which the embodiment of the present invention is applied. FIG. 4(a) is a circuit diagram showing an embodiment of
, -(b) and (c) are explanatory diagrams of the detection element, respectively;
FIG. 5 is a characteristic curve diagram of the detector, and FIG. 6 is a detailed explanatory diagram of the control section. DESCRIPTION OF SYMBOLS 1...Air flow rate detector, 2...Control unit, 11...Detection unit, 12...Identification signal generation unit, 21...・・A/D converter, 22...
...Identification control unit, 23...Memory, 24...
...Air flow rate calculation section. Figure 1 + 2: r & Spear 1 No. So 1 Shu 22: Kamebetsu Control Se 24:! Xet, 11JLtF Figure 2 Figure 4

Claims (3)

[Claims] 1. In an engine control device that converts at least one physical quantity that represents the operating state of the engine into electrical data and performs engine control based on this electrical data, the conversion characteristics necessary for capturing the physical quantity are determined in advance. An engine control device comprising: a storage means storing a plurality of types of conversion characteristics, and configured such that a predetermined conversion characteristic is selected depending on the type of detection means used to take in the physical quantity. 2. In claim 1, the detection means comprises:
An engine control device comprising a function of generating a predetermined identification signal depending on the type of the engine control device, and configured such that the selection of the predetermined conversion characteristic is automatically performed in accordance with the identification signal. 3. 3. The engine control device according to claim 2, wherein at least one of the physical quantities is an intake air flow rate of the engine, and the identification signal is an electrical signal having a meaning in terms of voltage value.