JPS647210B2 - - 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.

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. There is a problem that overheating occurs due to an insufficient amount of cooling water being fed, or overcooling occurs due to an excessive amount of cooling water being fed.

Therefore, as shown in Japanese Patent Application Laid-Open No. 53-136144, the water pump can be driven and controlled independently of the engine rotation, and the rotation speed of the water pump is controlled depending on, for example, the engine temperature. A system has been proposed that aims to maintain the engine temperature at a stable temperature and obtain a good cooling function.

However, even when controlling the water pump rotation speed according to the engine operating condition as described above, for example, when there is insufficient cooling water, when the radiator fan does not operate, or when knocking occurs for a long period of time, etc. This has the problem that the engine temperature, that is, the cooling water temperature, rises abnormally, resulting in an overheating state.

In view of this, the present invention controls the water pump rotation speed based on the operating state of the engine so that the engine temperature becomes a stable temperature, and when the engine temperature becomes higher than the stable temperature by more than a set value, The purpose is to prevent the occurrence of an abnormally high temperature state by increasing the water pump rotation speed more than the control rotation speed based on the above-mentioned operating conditions.

That is, the engine water pump control device according to the present invention includes a drive device that drives the water pump independently of the engine rotation and whose rotation speed can be adjusted, and a temperature sensor that detects the engine temperature. a main control means for controlling the drive device to increase or decrease the water pump rotation speed according to the operating state of the engine so that the temperature becomes a stable temperature, and an engine temperature set from the stable temperature in response to the output of the temperature sensor. The invention is characterized by being provided with a control device comprising an abnormality control means for controlling the drive device so as to increase the water pump rotation speed above the rotation speed controlled by the main control means when the rotation speed exceeds a specified value. .

Therefore, in the above-mentioned water pump control device, the main control means basically controls the engine temperature to a stable temperature by increasing or decreasing the water pump rotation speed based on the operating state of the engine. When the engine temperature becomes higher than the stable temperature by more than a set value, that is, when the engine temperature cannot be maintained near the stable temperature by the control based on the above-mentioned operating conditions, the abnormality control means performs the following:
The water pump rotational speed is increased above the rotational speed controlled by the main control means, and the amount of cooling water supplied is increased, thereby improving the cooling ability of the engine by this cooling water.

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 driven by a drive device 8 so that the drive can be controlled independently of the engine rotation, that is, the rotation speed can be adjusted. In this case, this drive device 8 is linked and controlled by a control device 9, and the water pump 7
The rotation speed 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, 13 is a rotation sensor that detects the engine rotation speed, and the outputs of the temperature sensor 12 and rotation sensor 13 are input to the control device 9,
The control device 9 receives the outputs of the temperature sensor 12 and rotation sensor 13 to control the drive device 8, and basically stabilizes the engine temperature by controlling the water pump rotation speed in response to fluctuations in the engine rotation speed. The engine temperature is maintained at a constant temperature, and the water pump rotational speed is increased when the engine temperature is higher than the stable temperature by a set value or more.

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.

Further, as the rotation sensor 13, a sensor that detects an ignition pulse, for example, is 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
It is a ventilation fan.

FIG. 2 shows an example of the control device 9, which includes an engine rotation speed detection circuit 17, an output current calculation circuit 18, and a current control circuit 23, and includes an output of the rotation sensor 13. a main control means for controlling the drive device 8 to increase or decrease the water pump rotation speed so that the engine temperature becomes a stable temperature in response to the engine temperature, a temperature detection circuit 20, a reference level transmission circuit 22, a comparison circuit 21 and a correction circuit 1.
9, and when the engine temperature becomes higher than the stable temperature by a set value or more in response to the output of the temperature sensor 12, the water pump rotation speed is increased above the rotation speed controlled by the main control means. and abnormality control means for controlling the device 8. That is, the output signal of the rotation sensor 13 is input to the rotation speed detection circuit 17 to detect the engine rotation speed, and the output signal of the rotation speed detection circuit 17 is input to the output current calculation circuit 18. This output current calculation circuit 18 calculates an output current to drive the electric motor 11 at a predetermined rotation speed in accordance with the magnitude of the engine rotation speed signal from the rotation speed detection circuit 17, and outputs it to the correction circuit 19. . On the other hand, the output signal of the temperature sensor 12 is input to the temperature detection circuit 20 to detect the engine temperature, and the output signal of this temperature detection circuit 20 is input to the comparison circuit 21 and is compared with the reference signal from the reference level generation circuit 22. be compared. The output signal of this reference level transmitting circuit 22 corresponds to an engine temperature higher than the stable temperature by a set value, and when the output signal from the temperature detection circuit 20 is higher than the above reference signal, that is, the detected engine temperature is higher than the set value of the stable temperature. When the value is higher than the value, the comparison circuit 21 outputs a signal to the correction circuit 19, and the correction circuit 19 outputs a signal to the output current calculation circuit 18.
A correction signal is added to the output signal of the output signal to obtain a large output signal. The output signal of the correction circuit 19 is outputted to the drive device 8 by the current control circuit 23.

The output current from the current control circuit 23 is applied to a relay 24 that starts and stops the electric motor 11, and is also applied to the base of a transistor 26 connected to a rotation control coil 25 of the electric motor 11. That is, when the output current becomes larger than a predetermined value, the contacts of the relay 24 are closed to start the electric motor 11, while a rotation control current corresponding to the output current flows to the rotation control coil 25 due to the action of the transistor 26, and the electric motor is activated. 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.

Further, when the engine temperature becomes higher than the stable temperature by a set value or more and the rotational speed of the water pump 7 is increased, an alarm (not shown) such as an alarm lamp is activated.

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 7, 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 speed ratio of this variable pulley mechanism.

Furthermore, in the above embodiment, the rotational speed of the water pump 7 is basically controlled in accordance with the engine rotational speed, but in addition, the rotational speed of the water pump 7 is controlled depending on the combination of the engine rotational speed and the intake negative pressure (load state). Further, basic control may be performed based on the engine temperature.

Therefore, according to the present invention as described above, the water pump can be driven and controlled independently of the engine rotation, and a main control means and an abnormality control means are provided so that the engine temperature can be maintained at a stable temperature. The water pump rotation speed is increased or decreased depending on the engine operating condition, while the engine temperature is detected and when the engine temperature is higher than the stable temperature by a set value, the water pump rotation speed is increased to control the amount of cooling water supplied. In order to improve the cooling capacity, the main control means basically keeps the engine temperature at a stable temperature. Even when the engine temperature rises rapidly due to fan failure, knocking, etc., it has the advantage of suppressing the temperature rise and preventing the occurrence of an abnormally high temperature state, thereby protecting the engine. .

[Brief explanation of drawings]

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 system. 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
... Rotation sensor, 17 ... Rotation speed detection circuit, 1
8... Output current calculation circuit, 19... Correction circuit, 2
0... Temperature detection circuit, 21... Comparison circuit, 22...
...Reference level transmission circuit, 23...Current control circuit,
24... Relay, 25... Rotation control coil, 26
...Transistor.

Claims (1)

[Claims] 1. A drive device that drives the water pump independently of the engine rotation and whose rotation speed can be adjusted;
a temperature sensor for detecting engine temperature, and a main control means for controlling the driving device to increase or decrease the water pump rotation speed according to the operating state of the engine so that the engine temperature becomes a stable temperature; abnormality control means for controlling the drive device so as to increase the water pump rotation speed above the rotation speed controlled by the main control means when the engine temperature becomes higher than the stable temperature by a set value or more in response to the output of the engine; An engine cooling device characterized by comprising a control device comprising: