JPS6337247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water pump control device for an engine.

Generally, in an engine, a water jacket is provided on the cylinder block and the cylinder head, and cooling water is circulated within the water jacket by driving a water pump to cool each part.

However, in the above-mentioned water pump, the rotation of the engine's crankshaft is usually transmitted through a belt through a pulley, and the water pump is constantly driven to rotate while the engine is rotating to circulate cooling water. The amount of circulating water (water pump rotation speed) is set to ensure sufficient cooling capacity to prevent overheating even when the outside temperature is high and the combustion heat of the engine is high. be. Therefore, when the engine temperature is lower than the set value in cold regions, etc., the amount of cooling water supplied may become excessive, resulting in supercooling, which increases the warm-up time, and requires unnecessary water pump operation. The drive results in a loss of engine output and impedes improvement in fuel efficiency.

Therefore, as shown in Japanese Patent Application Laid-Open No. 53-136144, the water pump that supplies cooling water to the cooling water passage can be driven and controlled independently of the engine rotation, and the engine temperature can also be detected. , the rotation speed of the water pump is controlled according to the engine temperature, and when the engine temperature is low, the amount of cooling water supplied by the water pump is reduced or stopped,
Engines have been proposed that improve fuel efficiency and shorten warm-up time by reducing engine output loss.

However, when controlling the rotation speed of the water pump according to the engine temperature as in the conventional example described above, it is preferable from the viewpoint of fuel efficiency to control the engine temperature at a high temperature near the upper limit. No problem occurs when the engine is in a steady state, but when the engine shifts to an accelerated state, there is a risk that overheating may occur in extreme areas. That is,
When acceleration occurs, the amount of heat generated by combustion increases rapidly, and the engine temperature rises accordingly, but because there is a large time lag during this time, the increase in the water pump rotational speed is delayed and the cooling capacity is reduced. The cylinder head near the combustion chamber (especially the exhaust port area) where the high-temperature combustion gas comes into contact becomes high temperature.
This high-temperature part becomes extremely overheated exceeding the allowable value, resulting in a problem that adversely affects durability and the like.

In view of this, the present invention detects the acceleration state of the engine, and controls the rotation speed of the water pump to a higher rotation speed than in a steady state during acceleration,
This is intended to prevent the occurrence of localized overheating during acceleration, while also reducing the output loss of the engine as a whole and improving warm-up performance.

That is, the engine water pump control device of the present invention includes a drive device that can drive and control the water pump independently of engine rotation, a temperature sensor that detects engine temperature, and an acceleration sensor that detects the acceleration state of the engine. and a control device that receives outputs from the temperature sensor and acceleration sensor, controls the drive device, controls the rotation speed of the water pump in accordance with the engine temperature, and controls the rotation speed to be higher than in a steady state during acceleration. It is characterized by the fact that it has been provided.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is an engine, 2 is a cooling water passage provided with a radiator 3, and the cooling water passage 2 is connected to a water jacket formed in the cylinder block 4 of the engine 1 from downstream of the radiator 3, and It passes through a water jacket formed within the cylinder head 5 and is configured to communicate with the upstream side of the radiator 3 via a thermostat 6.

A water pump 7 for feeding cooling water is interposed in the cooling water passage 2, and the water pump 7 is configured to be able to be driven and controlled independently of engine rotation by a drive device 8, and this drive device 8 is controlled in conjunction with a control device 9, and the rotational speed of the water pump 7 is controlled.

That is, the water pump 7 is connected to an electric motor 11 via a transmission belt 10, and the operation of the electric motor 11 is controlled by signals from a control device 9.

Further, 12 is a temperature sensor that detects the engine temperature, and the output of the temperature sensor 12 is input to the control device 9, and the control device 9 receives the output of the temperature sensor 12 and controls the drive device 8. When the engine temperature is low, the rotation speed of the water pump 7 is reduced or stopped, and when the engine temperature rises, the water pump 7 is
The rotation speed of the engine is increased or the drive is started.

In the illustrated case, the temperature sensor 12 is mounted on the cylinder head 5 of the engine 1 and is configured to detect the engine temperature from the cooling water temperature or wall temperature of the high temperature portion.

On the other hand, 13 is an acceleration sensor that detects the acceleration state of the engine 1, and the output of the acceleration sensor 13 is also input to the control device 9, and the control device 9 receives the output of the acceleration sensor 13 and controls the drive device 8. When the engine 1 is in an accelerated operating state, the rotational speed of the water pump 7 is increased to a higher rotational speed than in a steady state.

As the acceleration sensor 13, a known sensor for detecting the acceleration state of the engine 1 can be used.
For example, a method that detects the rate of change in the accelerator pedal, a method that detects the throttle valve opening of the carburetor, and a method that detects the change in the intake negative pressure may be used as appropriate.

Furthermore, 14 is a heating device (radiator) branch-connected to a part of the cooling water passage 2, and the amount of cooling water supplied from the cooling water passage 2 to the heating device 14 is adjusted by an on-off valve 15. In addition, 16 is a heating device 14
This is a ventilation fan.

FIG. 2 shows an example of the control device 9, in which the output signal of the temperature sensor 12 is input to a temperature detection circuit 17 to detect the engine temperature, and the output signal of the temperature detection circuit 17 is used to calculate the output current. The signal is input to the circuit 18. This output current calculation circuit 18
The correction circuit 19 calculates an output current to drive the electric motor 11 at a predetermined rotation speed in accordance with the magnitude of the engine temperature signal from the temperature detection circuit 17.
Output to. The output signal of the acceleration sensor 13 is inputted to the correction circuit 19 via the processing circuit 20, and when the engine 1 is in an acceleration state, the correction signal is added to the output signal of the output current calculation circuit 18 to increase the output current. This is the output current. The output signal of the correction circuit 19 is outputted to the drive device 8 by the current control circuit 21.

The output current from the current control circuit 21 is applied to a relay 22 that starts and stops the electric motor 11, and is also applied to the base of a transistor 24 connected to a rotation control coil 23 of the electric motor 11. That is, when the output current becomes larger than a predetermined value, the contacts of the relay 22 are closed to start the electric motor 11, while a rotation control current corresponding to the output current flows to the rotation control coil 23 due to the action of the transistor 24, and the electric motor is started. It is configured to control the rotation speed of the motor 11, that is, the rotation speed of the water pump 7, to a predetermined rotation speed.

In the above embodiment, the cooling water passage 2 is one system, but this cooling water passage is connected to the first
It is also applicable to a system in which the cooling water passage is branched into two systems: a cooling water passage and a second cooling water passage that cools the low temperature part (cylinder block 4) of the engine 1.

Further, in the above embodiment, an example is shown in which the electric motor 11 is used as the drive device 8 of the water pump 4, but the present invention is not limited to this. For example, the water pump is connected to the output shaft of the engine. The driving device may be configured to drive in conjunction with each other via a variable pulley mechanism, and to control the gear ratio of this variable pulley mechanism.Furthermore, the water pump may be connected to the output shaft of the engine via a clutch mechanism. It is also possible to use a driving device that drives in conjunction with each other.

Therefore, according to the present invention as described above, the rotation speed of the water pump is controlled according to the engine temperature,
This eliminates unnecessary driving of the water pump and improves engine output loss, improving fuel economy and warm-up performance, while also controlling the water pump rotation speed to a higher rotation speed than in steady state when the engine is accelerating. In this way, it is possible to prevent the occurrence of localized overheating in an accelerated state.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention, with FIG. 1 being an explanatory diagram showing the overall configuration, and FIG. 2 being a control circuit diagram showing an example of a control device. DESCRIPTION OF SYMBOLS 1... Engine, 2... Cooling water passage, 3... Radiator, 6... Thermostat, 7... Water pump, 8... Drive device, 9... Control device, 1
1...Electric motor, 12...Temperature sensor, 13
...Acceleration sensor.

Claims (1)

[Claims] 1 A drive device that can drive and control the water pump independently of the engine rotation, a temperature sensor that detects the engine temperature, an acceleration sensor that detects the acceleration state of the engine, and a drive device that receives the outputs of the temperature sensor and acceleration sensor. A water pump control for an engine, comprising: a control device that controls the drive device to control the rotation speed of the water pump according to the engine temperature, and controls the rotation speed to be higher than in a steady state during acceleration. Device.