JPH0261608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water pump control device for an engine, and more particularly to one in which the water pump is controlled to have a variable speed ratio relative to the rotation of the engine.

(Prior Art) Conventionally, a water pump for circulating cooling water inside an engine has been driven directly by the engine at a constant speed ratio with respect to engine rotation. However, recently, in order to reduce driving loss and improve fuel efficiency, as well as precisely control engine temperature, water pumps have been
By using its own motor or by connecting it to the engine via a variable pulley or clutch, the speed ratio is variable with respect to the engine rotation, that is, it is driven independently of the engine rotation. Things (Utility Model Application Publication No. 138630, Utility Model Application Publication No. 1983-1986)
138631) has been proposed.

(Problem to be Solved by the Invention) By the way, when controlling the drive of a water pump that can be driven independently of the engine rotation in accordance with the engine temperature, the temperature distribution throughout the engine is not uniform, and the temperature distribution near the combustion chamber is uneven. Since there is a large temperature difference between the high temperature part of the cylinder block and the low temperature part of the lower part of the cylinder block, if the temperature is controlled based on the temperature of the high temperature part, the engine tends to be overcooled. In particular, if the temperature is controlled based on the temperature of the low-temperature section, there is a problem in that the engine cannot be cooled sufficiently, which may cause the engine to overheat.

In view of this point, the present invention has been developed in such a way that when the water pump, which can be driven independently of engine rotation, is driven and controlled according to the engine temperature as described above, the temperature of the low-temperature part of the engine is adjusted to the temperature of the high-temperature part of the engine. It is an object of the present invention to provide an engine water pump control device that can control the temperature of the engine without causing insufficient cooling and suppressing overcooling by controlling the water pump accordingly.

(Means for Solving the Problems) In order to achieve the above object, the solution means of the present invention includes a water pump for circulating cooling water inside the engine, and a speed ratio of the water pump to the engine rotation. a drive device that drives variably;
a first temperature sensor installed at the bottom of the cylinder block to detect the temperature of the low temperature part of the engine; a second temperature sensor installed near the combustion chamber to detect the temperature of the high temperature part of the engine; and the first and second temperature sensors. and a control circuit that receives the output of the controller and controls the drive device based on the temperature obtained by adding the temperature of the low temperature section to the temperature of the high temperature section.

(Function) Accordingly, in the present invention, the first temperature sensor detects the temperature of the low-temperature part of the engine at the lower part of the cylinder block (where the low-temperature cooling water flows in after heat is radiated by the radiator), and the second temperature sensor The sensor detects the temperature of the high temperature part of the engine near the combustion chamber, and these detection signals are each input to a control circuit. Then, the control circuit controls the drive device based on the temperature of the engine's high-temperature section and the temperature of the engine's low-temperature section, so that the rotation speed of the water pump is changed between the temperature of the engine's high-temperature section and the temperature of the low-temperature section of the engine. The temperature of the engine is controlled according to the temperature that reflects the temperature.

In this case, the temperature of the engine is controlled based on the engine temperature signal that controls the water pump, which reflects the temperature of the engine's high-temperature parts and the temperature of its low-temperature parts. The relaxation is suppressed and the temperature is controlled to an appropriate temperature.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, 1 is an engine, 2 is a water pump for circulating cooling water inside the engine 1, and 3 is a radiator, and the engine 1 and the radiator 3 are connected to a first circulation path 4a and a first circulation return path. 4b to form a first circulation passage 4. A bypass passage 5 that branches off from the middle of the first circulation passage 4a and bypasses the radiator 3 is provided in parallel to the first circulation passage 4, and a thermos A tattoo 6 is provided. When the engine is cold and the cooling water temperature is lower than the set value, the first circulation passage 4a is closed by the closing operation of the thermostat 6 and the bypass passage 5 is opened. On the other hand, after the engine warms up when the cooling water temperature is higher than the set value, the thermostat 6 is activated to close the bypass passage 5 and the first circulation passage 4a is closed.
When opened, cooling water is circulated through the radiator 3 to cool the engine 1 normally. Further, 7 is a second circulation passage for circulating the cooling water of the engine 1 to the heat core 8,
The downstream end of the second circulation passage 7 is connected to the bypass passage 5.
The bypass passage 5 and a part of the first circulation return passage 4b are also used as a part of the second circulation passage 7. A switching valve 9 is interposed in the middle of the second circulation passage 7, and when the switching valve 9 is opened, cooling water is circulated to the heater core 8, and the heater core 8 directs air from a blower (not shown). is configured to generate warm air.

Reference numeral 10 denotes a drive device comprising a motor 12 that independently drives the water pump 2 via a belt transmission mechanism 11 so that the speed ratio is variable with respect to the rotation of the engine 1. A control circuit 13 for controlling the motors 12 is connected to the ten motors 12.

Reference numeral 14 denotes a first temperature sensor which is disposed in a low temperature section of the lower part of the cylinder block of the engine 1 (a section into which the cooling water radiated by the radiator 3 flows) and detects the temperature of the low temperature section. Each temperature sensor 1 is a second temperature sensor disposed in a high temperature part near the room to detect the temperature of the high temperature part.
Detection signals 4 and 15 are input to the control circuit 13.

As shown in FIG. 2, the control circuit 13 is a first temperature detection circuit that outputs a voltage signal corresponding to the temperature of the low temperature section of the engine 1 in response to a detection signal (resistance value signal) of the first temperature sensor 14. 16, a second temperature detection circuit 17 that outputs a voltage signal corresponding to the temperature of the high temperature portion of the engine 1 according to the detection signal of the second temperature sensor 15, and from the first and second temperature detection circuits 16 and 17. a representative temperature calculation circuit 18 that receives an output signal from the engine 1 and outputs a representative temperature signal that takes the temperature of the low temperature part into consideration with the temperature of the high temperature part of the engine 1; an output current calculation circuit 19 that outputs an output current signal obtained by calculating the output current to the motor 1 according to the output current signal from the output current calculation circuit 19;
2. The current control circuit 20 controls the output current to 2. Then, according to the output from the current control circuit 20, the field current to the excitation coil 12a of the motor 12, which is supplied with power from the power source B, is controlled via the transistor Tr, and the output from the current control circuit 20 controls the field current to the excitation coil 12a of the motor 12, which is supplied with power from the power source B. MR
By turning ON and energizing the electric element 12b of the motor 12 from the power source B, the motor 12 (drive device 10) is driven and controlled according to a representative temperature that takes into account the temperature of the high-temperature section and the temperature of the low-temperature section of the engine 1. It is something. In addition, in FIG. 2, S is a key switch.

Next, the operation of the above embodiment will be explained.
The temperature of the low temperature part of the engine 1 is detected by the first temperature sensor 14, and the temperature of the high temperature part of the engine 1 is detected by the second temperature sensor 15, and these detection signals are inputted to the control circuit 13. Ru. Then, in the control circuit 13, the first
The detection signals from the second temperature sensors 14 and 15 are detected by the first and second temperature detection circuits 16 and 17, respectively, to determine the temperature of the low temperature part of the engine 1 and the temperature of the low temperature part of the engine 1.
After being converted into a voltage signal corresponding to the temperature of the high temperature part of the engine 1, the representative temperature calculation circuit 18 outputs a representative temperature signal corresponding to the representative temperature obtained by adding the low temperature part to the temperature of the high temperature part of the engine 1. In response to the signal, the output current calculation circuit 19 outputs an output current signal corresponding to a preset output current to the motor 12 based on the engine temperature, and the current control circuit 20 controls the output current to the motor 12. Ru. As a result, the field current of the motor 12 is controlled according to the output current signal,
The rotation speed of the motor 12, that is, the water pump 2
The rotational speed of the engine 1 is controlled in accordance with a representative temperature obtained by adding the temperature of the high-temperature section and the temperature of the low-temperature section of the engine 1, so that the temperature of the engine 1 is controlled.

In that case, the engine temperature signal that controls the water pump 2 is a representative temperature signal that reflects the temperature of the high temperature part of the engine 1 and the temperature of the low temperature part, and the temperature of the engine 1 is controlled based on this representative temperature. Therefore, the temperature of the engine 1 is controlled to an appropriate temperature while reducing and suppressing supercooling without causing insufficient cooling, and good engine cooling performance can be ensured.

In the above embodiment, a motor 12 that is driven independently of the engine is provided as the drive device 10 that drives the water pump 2 at a variable speed ratio with respect to the rotation of the engine 1, and the motor 12 drives the belt transmission mechanism. Although the water pump 2 is driven through the engine 11, the water pump 2 may be driven by connecting the engine 1 and the water pump 2 through a variable pulley or a clutch, but the control In terms of ease of operation, the motor as in the above embodiment is preferable.

(Effects of the Invention) As explained above, according to the present invention, the water pump, which can be driven independently of the engine rotation, is operated based on the temperature of the high-temperature part of the engine reflecting the temperature of the low-temperature part of the engine. As a result, the temperature control by the water pump of the engine can be appropriately performed while reducing and suppressing supercooling without causing insufficient cooling.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the invention.
The figure shows the engine cooling water circulation system, and FIG. 2 is a block diagram of the control circuit. DESCRIPTION OF SYMBOLS 1... Engine, 2... Water pump, 10... Drive device, 12... Motor, 13... Control circuit, 14...
First temperature sensor, 15...Second temperature sensor, 16...
First temperature detection circuit, 17...Second temperature detection circuit, 1
8...Representative temperature calculation circuit, 19...Output current calculation circuit, 20...Current control circuit.

Claims (1)

[Claims] 1. A water pump for circulating cooling water inside the engine; a drive device that drives the water pump at a variable speed ratio relative to the engine rotation;
a first temperature sensor installed at the bottom of the cylinder block to detect the temperature of the low temperature part of the engine; a second temperature sensor installed near the combustion chamber to detect the temperature of the high temperature part of the engine; and the first and second temperature sensors. A water pump control device for an engine, comprising a control circuit that receives an output of the engine and controls the drive device based on a temperature obtained by adding the temperature of the low temperature portion to the temperature of the high temperature portion.