JPH0327745B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine control device that detects the humidity of intake air and corrects and controls various control devices governing the combustion state of the engine in accordance with changes in the humidity.

When the humidity of the outside air changes, the humidity of the intake air changes, and the combustion rate in the combustion chamber of the engine changes under the influence of the moisture in the intake air. That is, when the humidity of the intake air is low, the combustion speed of the engine is high, and as the humidity increases, the combustion speed becomes slow.

For this reason, conventionally, when the humidity of the intake air is low, the engine's ignition timing advance is delayed from the normal advance, and when the humidity becomes high, the ignition timing is advanced, thereby preventing knocking caused by abnormal engine combustion and reducing fuel consumption. There is a known method that aims to improve the performance (Japanese Unexamined Patent Publication No. 156234/1983).

However, the humidity of the intake air is usually detected as relative humidity, not the actual amount of moisture contained in the intake air, that is, absolute humidity.

However, since it is the amount of moisture in the intake air that affects combustion, there has been a problem in that it is difficult to adequately control relative humidity.

In order to improve the above-mentioned drawbacks, this invention simultaneously measures the humidity and temperature of the air taken into the engine, corrects the humidity of the intake air with temperature, and controls the combustion state of the engine according to this corrected humidity. The purpose of the present invention is to provide an engine control device that controls various control devices such as an ignition timing setting device and has good operating performance and high combustion efficiency.

The present invention will be specifically described below based on embodiments shown in the drawings.

In Fig. 1, 1 is the engine body, 2 is an intake passage, and this intake passage 2 has an air flow sensor 3.
A basic injection pulse generator 5, which is one of various control devices that receives the output signal from the air flow sensor 3 and the output signal from the engine rotation speed sensor 4, is connected to the fuel injection valve via an arithmetic circuit 6. 7
electrically connected to.

Reference numeral 8 denotes a humidity sensor for detecting the humidity S% of the intake air A in the intake passage 2, and is connected to the first correction factor generating circuit 9. 10 is the temperature of intake air A
This is an intake air temperature sensor for detecting T°, and is connected to the second correction factor generation circuit 11. The humidity signal from the first correction factor generating circuit 9 is corrected with the temperature signal from the second correction factor generating circuit 11, and then input to the arithmetic circuit 6, which corrects the output signal of the basic injection pulse generator 5. Add.

The first and second correction factor generating circuits 9 and 11 and the arithmetic circuit 6 constitute a control circuit.

In the above configuration, the amount of intake air A is detected by the air flow sensor 3, and the detected output is inputted to the basic injection pulse generator 5 together with the output signal from the rotation speed sensor 4, and fuel is injected according to the amount of intake air. The fuel injected from the valve 7 and supplied into the combustion chamber of the engine body 1 is appropriately controlled.

However, if the humidity S of the intake air A changes due to changes in outside air humidity, the air-fuel ratio will inevitably change.
In order to correct this, the humidity signal from the humidity sensor 8 is applied to the first correction factor generation circuit 9, and when the humidity increases, the amount of oxygen from the fuel injection valve 7 decreases by the amount of oxygen in the intake air A. The arithmetic circuit 6 adjusts the fuel injection amount using a correction signal from the first correction factor generation circuit 9 so as to reduce the fuel injection amount.

Furthermore, when the temperature T of the intake air A increases, as shown by the characteristic S in Figure 2, even if the humidity is the same S%, the amount of moisture contained in the intake air A (M (g/cm ³ ) increases, and the amount of oxygen in the intake air A decreases by the increased amount of moisture. In order to correct this, the temperature signal from the intake air temperature sensor 10 is applied to the second correction factor generating circuit 11, and the temperature signal from the fuel injection valve 7 is applied to the second correction factor generating circuit 11, and the temperature signal from the fuel injection valve 7 is applied to the second correction factor generating circuit 11. Temperature correction is added to the humidity signal from the first correction factor generation circuit 9 to correct the arithmetic circuit 6 so as to reduce the fuel injection amount.

Thereby, the combustion efficiency of the engine can be increased, driving performance without the risk of knocking can be obtained, and moreover, it can contribute to improving fuel efficiency.

In the above embodiment, a case has been described in which the fuel injection valve 7 is controlled to correct the air-fuel ratio. It can be applied when performing correction control with a correction factor according to temperature.

As is clear from the above description, according to the present invention, the control amount based on the amount of moist air of various control devices that govern the combustion state of the engine is corrected in accordance with the amount of dry air based on the moisture content at the temperature. As a result, improvements in drivability, output, and fuel efficiency can be achieved. In addition, since a correction factor is used to calculate the amount of dry air, the amount of data that needs to be stored in the storage means is small, and the storage means has a small storage capacity and can be easily calculated at each temperature. This method has the advantage of being able to determine the moisture content, that is, the amount of dry air.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an engine control device according to the present invention, and FIG. 2 is a diagram showing the relationship between humidity and temperature to explain the operation of FIG. 1. 1...Engine body, 2...Intake passage, 3...
Air flow sensor, 7... Fuel injection valve, 8... Humidity sensor, 9... First correction factor generation circuit, 10...
Intake temperature sensor, 11... second correction factor generation circuit.

Claims (1)

[Scope of Claims] 1. An intake air amount detection means for detecting the humid air amount of the intake air taken into the engine; an intake air temperature sensor for detecting the temperature of the intake air; an intake air humidity sensor for detecting the humidity of the intake air; storage means for storing the relationship between moisture content in the intake air and humidity at a predetermined temperature; and a device for receiving a signal from the intake air humidity sensor and extracting the moisture content in the intake air corresponding to the humidity from the storage means. water content detection means; receiving a signal from an intake air temperature sensor and detecting the water content in the intake air detected by the water content detection means;
water content correction means for correcting the water content at the temperature based on a predetermined correction factor that is set in advance to increase as the temperature rises; 1. A control device for an engine, comprising: control amount correction means for correcting a control amount based on a moist air amount of various controlling devices in accordance with a dry air amount based on a moisture content at the temperature.