JPH06117247A - Controller of engine - Google Patents

Abstract

PURPOSE:To provide the controller of an engine which can accurately control a cooling fan to be controlled based on an engine cooling water temperature at a position except the vinicity of an intake port, based on the engine cooling water temperature in the vicinity of the intake port. CONSTITUTION:A set operational temperature of a cooling fan 43 is increased by a control unit 31 as a detected intake gas temperature becomes higher and thermal influence of outer air on the engine water in the vicinity of the intake gas port 7 is offset.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device.

[0002]

2. Description of the Related Art In an engine, Japanese Patent Laid-Open No. 59-180
As shown in Japanese Patent Publication No. 023, a cooling fan is provided to cool a radiator, a condenser, etc., but the cooling fan is generally turned on and off in the following manner.
A fan water temperature sensor is attached to the cover of a thermostat interposed between a radiator and the like and the engine body, and control is performed based on the water temperature detected by the fan water temperature sensor.

Recently, from the viewpoint of reducing the number of parts, in a device for controlling the controlled means based on the state of the engine cooling water temperature outside the engine body, the controlled means is unique such as the above-mentioned fan water temperature sensor. It has been considered to omit the water temperature detecting means and use the fuel control water temperature detecting means for detecting the cooling water temperature in the vicinity of the intake port.

[0004]

However, as described above, when the water temperature detecting means in the vicinity of the intake port is also used as the water temperature detecting means in a portion outside the engine body, the engine cooling in the vicinity of the intake port is performed. Since the water is affected by the heat of the outside air (intake air), the engine cooling water temperature when the controlled means at the position where the controlled means-specific water temperature detection means should be provided is equal to the outside air temperature. It tends to change depending on the state and not reach a predetermined value (constant value). In particular, the higher the outside temperature,
Since the engine cooling water temperature in the vicinity of the temperature becomes high, the engine cooling water temperature at the time of operating the controlled means at the above-mentioned position tends to largely deviate from the predetermined value. Therefore, when the water temperature detecting means in the vicinity of the intake port is also used as the water temperature detecting means in other places, when controlling the controlled means based on the detected water temperature of the unique water temperature detecting means in other places. In comparison, the operating accuracy is inferior. The present invention has been made in view of the above circumstances, and an object thereof is to provide a controlled means to be controlled on the basis of the engine cooling water temperature in a portion other than the vicinity of the intake port to the engine cooling water temperature in the vicinity of the intake port. An object of the present invention is to provide a control device for an engine that can be accurately controlled based on the above.

[0005]

In order to achieve the above object, the present invention provides a water temperature detecting means for detecting the engine cooling water temperature near the intake port, and an intake temperature detecting means for detecting the intake temperature. A setting means for setting the operating temperature of the controlled means, a control means for determining the operation of the controlled means based on a comparison between the water temperature detected by the water temperature detecting means and the operating temperature set by the setting means; And a correction means for increasing the set operating temperature of the setting means as the intake air temperature detected by the air temperature detection means increases. With the above structure, the higher the detected intake air temperature by the correction means, the higher the set operating temperature becomes, so the thermal influence of the outside air on the engine cooling water in the vicinity of the intake port is offset, and the outside air temperature changes. However, based on the engine cooling water temperature near the intake port, the controlled means
The engine cooling water temperature in a portion other than the vicinity of the intake port is operated at a constant temperature (predetermined value). For this reason, the controlled means to be controlled based on the engine cooling water temperature at a location other than the vicinity of the intake port can be controlled accurately based on the engine cooling water temperature near the intake port.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes an Otto-type engine body of a 4-cycle reciprocating type. The engine body 1 is fitted into a cylinder block 2, a cylinder head 3, and a cylinder 2a of the cylinder block 2 as is known. A combustion chamber 5 is defined by the inserted piston 4.
A spark plug 6 is arranged in the combustion chamber 5, and
The intake port 7 and the exhaust port 8 are opened, and these ports 7 and 8 are opened and closed by an intake valve 9 or an exhaust valve 10 at a known timing in synchronization with the engine output shaft. In the intake passage 21 connected to the intake port 7, an air cleaner 22, an air flowmeter 24 for detecting the intake air amount, a throttle valve 25, a surge tank 26, and a fuel injection are sequentially provided from the upstream side to the downstream side. A valve 27 is provided.

In front of the engine body 1, there is a radiator.
An engine cooling water circulation passage 42 is formed between the engine body 1 and the radiator 41. The radiator 41 is a cooling fan 4
It is supposed to be cooled by 3, and the circulating water channel 4
In 2, the thermostat 44 is interposed.

Reference numeral 31 in FIG. 1 denotes a control unit constituted by a micro computer, and the control unit 31 has sensors 32, 33 in addition to the signal from the sensor 24.
The signal from is input. The sensor 32 detects the intake air temperature (outside air temperature). The sensor 33 detects the engine cooling water temperature in the vicinity of the intake port 7. On the other hand, the control unit 31 outputs a control signal to the fuel injection valve 27 and the cooling fan 43.

Next, an outline of control by the control unit 31 will be described with reference to FIGS. 2 and 3. The control unit 31 performs the conventional fuel control based on the cooling water temperature and the like in the vicinity of the intake port 7 in consideration of vaporization and atomization in the vicinity of the intake port 7, and also adds the intake temperature to the control condition. The operation of the cooling fan 43 is to be controlled. That is, in the operation control of the cooling fan 43, as shown in FIG. 2, the set operating water temperature of the cooling fan 43 is set (corrected) to be higher as the intake air temperature is higher. , Sensor 3 by heat of intake air
Even if the detected water temperature of 3 becomes high, the set operating water temperature also becomes high. Therefore, as shown by the solid line in FIG. 3, the cooling fan 43 at the outlet of the thermostat 44 is activated regardless of the state of the intake air temperature. The cooling fan 43 can be turned on with the cooling water temperature kept constant (predetermined value). Therefore, in the above control, when the cooling fan 43 is operating at the outlet of the thermostat 44 according to the state of the intake air temperature, as in the case where the set operating temperature of the cooling fan 43 is not corrected according to the intake air temperature. That the cooling water temperature of the product changes (see the chain line in Fig. 3)
Disappears.

Next, the control by the control unit 31 will be described in detail with reference to the flowchart of FIG.
In the following description, S indicates a step. First, in S1, various signals from the above-mentioned sensors 32, 33, etc. are read, and thereafter, in S2, the set operating water temperature of the cooling fan 43 is obtained from the intake air temperature based on FIG.
As a result, the thermal influence of the intake air on the cooling water in the vicinity of the intake port 7 is offset. Then, in the next S3, it is determined whether or not the set operating water temperature in S2 is higher than the water temperature detected by the sensor 33 (current water temperature).
If the determination in S3 is YES, the cooling fan 43 is turned off in S4, while the determination in S3 is N.
When it is O, the cooling fan 43 is turned on in S5. Then, after this, in S6, normal fuel injection control is performed.

FIG. 5 shows a second embodiment. In the second embodiment, when the intake air temperature (outside air temperature) exceeds a predetermined temperature and becomes high, the set operating water temperature of the cooling fan 43 is positively lowered. As a result, when the intake air temperature becomes high, the cooling fan 4
3 becomes easier to operate, the reliability of the engine body 1 can be improved, and the temperature inside the engine room can be lowered.

FIG. 6 shows a third embodiment. In the third embodiment, the set operating water temperature of the cooling fan 43 is positively raised when the intake air temperature (outside air temperature) becomes lower than a certain temperature and becomes low. As a result, when the intake air temperature is low, the cooling fan 43 is less likely to operate, and the warm-up performance and the like can be improved.

[0013]

As described above, according to the present invention, the controlled means to be controlled on the basis of the engine cooling water temperature other than the vicinity of the intake port is controlled based on the engine cooling water temperature near the intake port. Can be controlled accurately.

[Brief description of drawings]

FIG. 1 is an overall system diagram showing an engine control device according to an embodiment.

FIG. 2 is a diagram showing a relationship between a set operating water temperature of a cooling fan and an intake air temperature.

FIG. 3 is a diagram showing a relationship between a cooling water temperature and an intake air temperature when a cooling fan is operating at a thermostat outlet.

FIG. 4 is a flowchart showing an example of operation control of a cooling fan.

FIG. 5 is an explanatory diagram illustrating a second embodiment.

FIG. 6 is an explanatory diagram illustrating a third embodiment.

[Explanation of symbols]

 7 Intake port 31 Control unit 32 Sensor 33 Sensor 43 Cooling fan

Claims (1)

[Claims] 1. A water temperature detecting means for detecting an engine cooling water temperature in the vicinity of an intake port, an intake temperature detecting means for detecting an intake temperature, a setting means for setting an operating temperature of a controlled means, and the water temperature detecting means. The control means for determining the operation of the controlled means based on the comparison between the detected water temperature by the setting means and the set operating temperature by the setting means, and the higher the detected intake air temperature by the intake air temperature detecting means, the higher the operating temperature set by the setting means. A control device for an engine, comprising: a correction unit for increasing the height.