JPH04259622A - Engine cooling device - Google Patents

Abstract

PURPOSE:To enhance the cooling effect of an auxiliary unit after the engine is stopped. CONSTITUTION:An engine supply line 41 is arranged coupling in series to a radiator 5 and a main water pump 6, and there a water-cooled engine 2 and a control valve 7 are furnished. A turbo-supercharger 3 and a sub-water pump 8 are installed in a supercharger supply line 4 coupled with the engine 2 parallelly and coupled in series to the main water pump 6. At least after the engine 2 is stopped, the engine supply line 41 is shut by the control valve 7, and the cooling water is circulated forcedly through the supercharger supply line 42 and radiator 5 by operating the sub-water pump 8.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cooling system for cooling an engine and auxiliary equipment mounted on a vehicle with cooling water.

0002

[Prior Art] In recent years, the number of vehicles equipped with auxiliary equipment such as turbo superchargers has increased, and it is important to prevent heat damage to the turbo superchargers, especially during dead soaking after high-load driving. There is a need to prevent excessive temperature rise.

[0003] Conventionally, for example, Utility Model Application No. 59-19453
In Publication No. 5, a cooling pipe line for supplying cooling water to a turbo supercharger is built in parallel with the engine in a cooling water circuit that connects an engine, a water pump, and a radiator in series, and the turbo cooling pipe An engine cooling system (prior art) has been proposed in which a tank is provided in the roadway to store cooling water for cooling a turbocharger after the engine is stopped.

0004

[Problems to be Solved by the Invention] However, in the conventional technology, when the engine is stopped, the water pump does not forcefully circulate the cooling water in the turbo cooling pipe line, so that the water inside the tank for cooling the turbo supercharger is The temperature of the cooling water rose quickly, and the cooling effect of the turbo supercharger could not be expected to be very effective.

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine cooling system that improves the cooling effect of auxiliary equipment after the engine is stopped.

[0006]

[Means for Solving the Problems] The present invention provides a water-cooled engine mounted on a vehicle, a radiator that cools the cooling water of the engine, and a space between the outflow side of the radiator and the inflow side of the engine. a water pump that is connected to the engine and rotationally driven by the engine to forcibly circulate cooling water flowing out from the radiator to the engine; and a water pump that is connected in series to the engine and connects the outflow side of the engine and the inflow side of the radiator. a first conduit connected in parallel to the engine and connecting an outflow side of the water pump and an inflow side of the radiator; and a water-cooled supplement provided in the second conduit. an electric pump that is provided in the second pipe line and forcibly circulates the cooling water flowing out from the radiator to the auxiliary machine; a solenoid valve that opens and closes the first pipe line; A technical means is adopted, which includes a control means for operating the electric pump and controlling the electromagnetic valve to close the first pipe line.

[0007]

According to the present invention, when the engine is stopped, the operation of the water pump driven by the engine is also stopped, but the solenoid valve is controlled by the operation of the control means to close the first pipe line provided with the engine. Then, all the cooling water flowing out from the radiator by operating the electric pump by the operation of the control means is forcibly circulated to the auxiliary equipment through the second pipe line connected in parallel to the engine. Therefore, the cooling water that has received heat in the auxiliary equipment is forced to circulate through the radiator and is cooled, thereby preventing the cooling water from rising excessively. Then, the cooled cooling water flows into the auxiliary equipment again through the second pipe line due to the operation of the electric pump, so that the auxiliary equipment is sufficiently cooled.

[0008]

According to the present invention, the auxiliary equipment can be cooled with the cooling water cooled by the radiator even after the engine is stopped, so that the cooling effect of the auxiliary equipment after the engine is stopped can be improved.

[0009]

[Example] The engine cooling system of the present invention is shown in FIGS. 1 to 3.
This will be explained based on an example shown in FIG. FIG. 1 is a schematic diagram showing the overall structure of an engine cooling system for a passenger car.

The engine cooling system 1 for a passenger car includes a cooling water circuit 4 for cooling an engine 2 and a turbocharger 3;
and a control device 10 that controls the cooling state of the engine 2 and turbocharger 3.

The engine 2 is a water-cooled gasoline engine, and cooling water is forcedly circulated within the water jacket 21. The turbo supercharger 3 is an auxiliary machine of the present invention, and is used to prepress the intake air or air-fuel mixture taken into the engine 2. Both the engine 2 and the turbocharger 3 are arranged in an engine compartment (not shown) of a passenger car.

The cooling water circuit 4 includes an engine supply pipe 41 as a first pipe in which a radiator 5, a main water pump 6, an engine 2 and a control valve 7 are arranged, a turbo supercharger 3 and a sub water pump 8. The supercharger supply pipe 42 as a second pipe, a bypass pipe 44 that is opened and closed by a thermostat 43, and a heater supply pipe 45 in which a heater core 9 is disposed are provided. thermostat 4
3 closes the bypass pipe 44 when the temperature of the cooling water rises above the set water temperature.

The radiator 5 is disposed at the front of the engine room of the passenger car, and cools the cooling water by exchanging heat between the air passing through the radiator 5 while the passenger car is running and the electric fan 51 sucks the cooling water flowing inside.

The main water pump 6 is a water pump according to the present invention, and is arranged along with the engine 2 and connected between the outflow side of the radiator 5 and the inflow side of the engine 2. This main water pump 6 forcibly circulates the cooling water flowing out from the radiator 5 to the engine 2 and turbocharger 3. In addition, main water pump 6
A pulley 61 is connected to the output shaft of the engine 2 via a belt (not shown). Therefore, when the engine speed is low, the circulating flow rate in the cooling water circuit 4 is low, and when the engine speed is high, the circulating flow rate in the cooling water circuit 4 is high.

The control valve 7 is a solenoid valve of the present invention, and is an electromagnetic three-way valve, which controls the circulation flow rate of the cooling water in the engine supply pipe 41 and the cooling water in the supercharger supply pipe 42. The circulating flow rate and the circulating flow rate of cooling water in the heater supply pipe line 45 are adjusted. Further, the control valve 7 changes the degree of opening of the engine supply pipe 41 from a fully closed state to a fully open state in a stepwise or continuous manner depending on the amount of energization.

The subwater pump 8 is an electric pump of the present invention, and is connected in parallel to the engine 2 and in series to the main water pump 6 and the radiator 5. This subwater pump 8 forcibly circulates the cooling water flowing out from the radiator 5 to the turbo supercharger 3. In addition, since the subwater pump 8 is rotationally driven by the electric motor 81, the circulating flow rate in the cooling water circuit 4 is circulated at a constant flow rate. The heater core 9 heats the air heading into the cabin of the passenger car by using the cooling water flowing inside the heater core 9 to heat the cabin of the passenger car.

The control device 10 is a control means of the present invention, and controls the amount of current applied to the control valve 7, the electric fan 51, and the electric motor 81 according to the outputs of the water temperature sensor 11 and the engine speed sensor 12.

The water temperature sensor 11 detects the temperature of the cooling water in the water jacket 21 of the engine 2, and sends an electric signal to the control device 10 when the water temperature rises to, for example, a reference temperature (subwater pump operating temperature) or higher. send to The engine rotation speed sensor 12 detects the engine rotation speed, and the engine rotation speed is in a high speed range (for example, 3000
A signal is sent to the control device 10 when the engine speed is in a low speed range (for example, less than 3000 rpm).

FIGS. 2 and 3 are flow charts showing an example of the operation of the control device 10. This flowchart starts when a key switch (not shown) is turned on. First, as shown in FIG. 2, it is determined whether the temperature of the cooling water in the water jacket 21 of the engine 2 has risen to a reference temperature or higher (step S1). When the water temperature has not risen above the reference temperature (N), the electric motor 81
energization is stopped (turned off) (step S2). and,
By controlling the amount of electricity supplied to the control valve 7, the engine supply pipe 4
The circulating flow rate (QT) of the cooling water flowing inside the supercharger supply pipe 42 is decreased (
QE>QT), for example, the engine supply pipe 41
is fully opened (step S3). Then return.

In step S1, when the water temperature has risen above the reference temperature (Y), it is determined whether the engine speed has increased to a high speed range (high speed) (step S4). When the speed has increased above the high speed range (Y), control in step S2 is performed.

In step S4, if the rotation has not reached the high speed range (N), the electric motor 81 is energized (turned on) as shown in FIG. 3 (step S5). and,
By controlling the amount of electricity supplied to the control valve 7, the engine supply pipe 4
The circulating flow rate (QT) of the cooling water flowing inside the supercharger supply pipe 42 increases (
QE<QT) (step S6). Then, it is determined whether the engine is stopped (step S7). Returns when the engine is not stopped (N).

In step S7, when the engine is stopped (Y), the amount of current supplied to the control valve 7 is controlled to completely close the engine supply pipe 41 (QE=0) (step S8). Subsequently, it is determined whether a certain period of time (10 seconds to 20 seconds) has elapsed (step S9). When the certain period of time has not elapsed (N), control in step S9 is performed.

[0023] In step S9, when a certain period of time has elapsed (Y), the electric motor 81 is de-energized (turned off).
(Step S10). Control is then terminated.

The operation of this engine cooling system 1 for a passenger car will be explained based on FIG. When the engine 2 is started by turning on the key switch, the water temperature of the cooling water in the water jacket 21 of the engine 2 is detected by the water temperature sensor 11. At this time, if the temperature of the cooling water is lower than the reference temperature, and furthermore, lower than the set water temperature of the thermostat 43, the cooling water discharged from the main water pump 6 is transferred to the water jacket 21 of the engine 2. A circuit is formed which returns to the main water pump 6 through a bypass line 44 .

[0025] When the water temperature rises above the set temperature of the thermostat 43, the bypass pipe 44 is closed by the thermostat 43. Therefore, as shown by the solid arrow in FIG. 1, a circuit is formed in which the cooling water discharged from the main water pump 6 passes through the water jacket 21 of the engine 2 and the radiator 5 and returns to the main water pump 6.

Furthermore, when the engine load such as vehicle speed, throttle opening, and engine speed increases, the temperature of the cooling water in the water jacket 21 of the engine 2 rises.
The temperature of the subwater pump 8 is raised to a reference temperature at which it can be operated.

At this time, for example, when the engine speed increases to a high speed range, the circulation flow rate of the cooling water in the cooling water circuit 4 is large, and while there is sufficient cooling performance of the radiator 5, the subwater pump 8 itself becomes a resistor, and the total circulating flow rate in the cooling water circuit 4 is reduced.

Therefore, by turning off the electric motor 81 of the subwater pump 8 and controlling the amount of electricity supplied to the control valve 7 to fully open the engine supply pipe 41, the total resistance is suppressed and the engine 2 is cooled. Ensure performance. In addition,
Even if the operation of the subwater pump 8 is stopped, cooling water flows into the supercharger supply pipe 42 due to the discharge force of the main water pump 6, so as shown by the broken line arrow in FIG. The low-temperature cooling water cooled by is forcedly circulated within the turbo supercharger 3. Therefore, the turbocharger 3 is cooled and each part of the turbocharger 3 is maintained at an appropriate temperature.

Further, for example, when the engine speed has decreased to a low speed range, the circulation flow rate of the cooling water in the cooling water circuit 4 is small, and the cooling performance of the engine 2 is reduced by using the main water pump 6 alone. Put it away. Therefore, the electric motor 81 is turned on to operate the subwater pump 8 to increase the circulation flow rate of the cooling water in the cooling water circuit 4.

At this time, the amount of current supplied to the control valve 7 is controlled so that, for example, the circulating flow rate of the cooling water in the engine supply pipe 41: the circulating flow rate of the cooling water in the supercharger supply pipe 42 is 3:7.
The degree of opening of the engine supply pipe 41 is controlled so that Therefore, the circulation flow rate of the cooling water in the supercharger supply pipe 42 increases, so that the circulation flow rate to the radiator 5 increases, and the circulation flow rate of the cooling water in the engine supply pipe 41 decreases, so that the circulation flow rate to the engine 2 increases. The circulation flow rate decreases.

[0031] Therefore, the cooling loss of the engine 2 is reduced by reducing the amount of heat received from the engine 2 by the cooling water, and the cooling performance of the engine 2 is improved by improving the cooling capacity of the radiator 5. Note that cooling water is supplied to the supercharger supply pipe 42 by the operation of the subwater pump 8.
Since there is forced circulation inside, the turbocharger 3 is sufficiently cooled and each part is maintained at an appropriate temperature.

When the engine 2 is stopped after driving the passenger car under high load (for example, when the engine 2 is stopped after driving on a slope at low speed and high engine speed,
Alternatively, if the engine 2 is stopped immediately after driving at high speed), the temperature of the turbocharger 3 may rise excessively and a malfunction may occur in the turbocharger 3.

At this time, when the electric motor 81 is turned on, the amount of current supplied to the control valve 7 is controlled, the subwater pump 8 is operated for a certain period of time, and the engine supply pipe 41 is completely closed, the broken line in FIG. Only the turbo cooling circuit indicated by the arrow is formed. Therefore, the cooling water discharged from the subwater pump 8 passes through the turbocharger 3 to cool each part of the turbocharger 3, is cooled by the radiator 5, and then flows into the turbocharger 3 again.

[0034] Therefore, since the turbocharger 3 is forcibly cooled by low-temperature cooling water, the durability of the turbocharger 3 can be improved by preventing the turbocharger 3 and the cooling water from becoming abnormally high.

(Modification) In this embodiment, an electromagnetic three-way valve is used as the electromagnetic valve, but an electromagnetic proportional control valve, an electromagnetic opening/closing valve, etc. may also be used as the electromagnetic valve. Note that when an electromagnetic on-off valve is used, the circulation flow rate in the first pipe line and the circulation flow rate in the second pipe line can be adjusted by controlling the valve opening time. In this embodiment, a bypass pipe, a heater supply pipe, a thermostat, and a heater core are provided in the cooling water circuit, but they may not be provided.

In this embodiment, a turbo supercharger is used as an auxiliary machine, but a water-cooled alternator or the like may also be used as an auxiliary machine. Note that either the auxiliary equipment or the electric pump may be located on the upstream side. Also, after the engine stops, the electric fan 5
1 may be operated together with the subwater pump 8.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall structure of a passenger car engine cooling system.

FIG. 2 is a flowchart showing an example of the operation of the control device.

FIG. 3 is a flowchart showing an example of the operation of the control device.

[Explanation of symbols]

1 Passenger car engine cooling system 2 Engine 3 Turbo supercharger (auxiliary equipment) 5 Radiator 6 Main water pump (water pump) 7
Control valve (electromagnetic valve) 8 Subwater pump (electric pump) 10 Control device (control means) 41 Engine supply pipe (first pipe) 42 Supercharger supply pipe (second pipe)

Claims (1)

[Claims] Claim 1: (a) a water-cooled engine mounted on a vehicle; (b) a radiator that cools cooling water for the engine; and (c) between an outflow side of the radiator and an inflow side of the engine. (d) a water pump connected in series to the engine and rotationally driven by the engine to forcibly circulate the cooling water flowing out from the radiator to the engine; (e) a second pipe line connected in parallel to the engine and connecting the outflow side of the water pump and the inflow side of the radiator;
f) A water-cooled auxiliary machine installed in this second pipe, and (g)
(h
) a solenoid valve that opens and closes the first conduit; and (i) control means that operates the electric pump and controls the solenoid valve to close the first conduit at least after the engine is stopped. engine cooling system.