JP3075289B2 - Engine cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, vehicles equipped with auxiliary equipment such as a turbocharger have been increasing, so that the heat damage of the turbocharger can be prevented. It is called for prevention of overheating.

[0003] Conventionally, for example, Japanese Utility Model Laid-Open No. 59-19453.
In Japanese Patent Laid-Open Publication No. 5 (1993) -1993, a cooling pipe line for supplying cooling water to a turbocharger is incorporated in a cooling water circuit in which an engine, a water pump and a radiator are connected in series, in parallel with the engine, and the turbo cooling pipe is further provided. 2. Description of the Related Art There has been proposed an engine cooling device (prior art) provided with a tank for storing cooling water for cooling a turbocharger after the engine is stopped on a road.

[0004]

However, in the prior art, when the engine is stopped, the forced circulation of the cooling water in the turbo cooling line by the water pump is not performed, so that the inside of the tank for cooling the turbocharger is not provided. The temperature of the cooling water immediately rose, and the cooling effect of the turbocharger could not be expected much.

[0005] It is an object of the present invention to provide an engine cooling device in which the cooling effect of accessories after the engine is stopped is improved.

[0006]

According to the present invention, there is provided a water-cooled engine mounted on a vehicle, a radiator for cooling a cooling water of the engine, and a radiator between an outlet side of the radiator and an inlet side of the engine. A water pump, which is connected to the engine, and forcibly circulates cooling water flowing out of the radiator by being driven by the engine and forcibly circulating the cooling water to the engine; A first pipe connected in parallel with the engine, a second pipe connecting the outflow side of the water pump and the inflow side of the radiator, and a water-cooled auxiliary provided in the second pipe. And an electric pump provided in the second pipe line for forcibly circulating cooling water flowing out of the radiator to the auxiliary machine, and the first pump at a downstream side of the engine. A third conduit branching from the passage and connecting the outflow side of the engine and the inflow side of the water pump, a heater core provided in the third conduit and exchanging heat between cooling water and room air; A three-way valve that is provided at a branch point between a first pipeline and the third pipeline and that adjusts a flow rate of cooling water to the first pipeline and the third pipeline; A technical means comprising a control means for operating the pump and controlling the three-way valve to cut off the flow of the cooling water into the engine is employed.

[0007]

According to the present invention, when the engine stops, the operation of the water pump driven by the engine also stops. However, the operation of the control means controls the three-way valve to cut off the flow of cooling water into the engine. All the coolant flowing out of the radiator by the operation of the electric pump by the operation of the control means is forcibly circulated to the auxiliary machine through the second pipe connected in parallel with the engine. For this reason, the cooling water received by the auxiliary machine is forcibly circulated through the radiator and cooled, thereby preventing an excessive rise of the cooling water. Then, the cooled cooling water flows into the auxiliary machine again through the second conduit by the operation of the electric pump, so that the auxiliary machine is sufficiently cooled.

[0008]

According to the present invention, since the auxiliary equipment can be cooled with the cooling water cooled by the radiator even after the engine is stopped, the cooling effect of the auxiliary equipment after the engine is stopped can be improved. Also, when the electric pump is operated (when the engine is stopped), a three-way valve is used to shut off the flow of cooling water to the engine, so that the cooling of the heater core is stopped while the supply of the cooling water to the engine is stopped when the electric pump is operated. Can supply water.

[0009]

1 to 3 show an engine cooling apparatus according to the present invention.
A description will be given based on one embodiment shown in FIG. FIG. 1 is a schematic diagram showing the entire structure of a passenger car engine cooling device.

A passenger car engine cooling device 1 includes a cooling water circuit 4 for cooling an engine 2 and a turbocharger 3.
And a control device 10 for controlling a cooling state of the engine 2 and the turbocharger 3.

The engine 2 is a water-cooled gasoline engine, and cooling water is forcibly circulated in a water jacket 21. The turbocharger 3 is an auxiliary machine of the present invention, and pre-presses intake air or air-fuel mixture taken into the engine 2. The engine 2 and the turbocharger 3 are both arranged in an engine room (not shown) of the passenger car.

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

The radiator 5 is disposed in front of the engine room of the passenger car, and cools the cooling water by exchanging heat between the air passing by the traveling of the passenger car and the suction of the electric fan 51 and the cooling water flowing inside.

The main water pump 6 is a water pump according to the present invention, which is disposed in association with the engine 2 and is connected between the outflow side of the radiator 5 and the inflow side of the engine 2. The main water pump 6 forcibly circulates the cooling water flowing out of the radiator 5 to the engine 2 and the turbocharger 3. The main water pump 6
The 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 an electromagnetic three-way valve,
The circulation flow rate of the cooling water in the engine supply circuit 41, the circulation flow rate of the cooling water in the supercharger supply pipe 42, and the heater supply pipe 45
It adjusts the circulation flow rate of the cooling water in the inside. Also,
The control valve 7 controls the engine supply line 4
The degree of opening of 1 is changed stepwise or continuously from the fully closed state to the fully opened state.

The sub water pump 8 is an electric pump according to the present invention, and is connected to the engine 2 in parallel and connected to the main water pump 6 and the radiator 5 in series. The sub water pump 8 forcibly circulates the cooling water flowing out of the radiator 5 to the turbocharger 3. Since the sub water pump 8 is driven to rotate by the electric motor 81, the circulation flow rate in the cooling water circuit 4 is circulated at a constant flow rate. The heater core 9 heats the air flowing into the passenger compartment of the passenger car with the cooling water flowing inside to heat the passenger compartment.

The control device 10 is a control means of the present invention, and controls the amount of electricity supplied 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 outputs an electric signal when the water temperature rises, for example, to a reference temperature (sub-water pump operating temperature) or higher. Send to The engine speed sensor 12 detects the engine speed, and when the engine speed is in a high speed range (for example, 3000).
When the engine speed is in a low-speed rotation range (for example, less than 3000 rpm), a signal is sent to the control device 10.

FIG. 2 and FIG. 3 are flowcharts showing an example of the operation of the control device 10. This flowchart is started 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 above the reference temperature (step S1). When the water temperature has not risen above the reference temperature (N), the electric motor 81
Is stopped (turned off) (step S2). And
By controlling the amount of current supplied to the control valve 7, the engine supply line 4 is controlled.
For example, the engine supply line 4 is set so that the circulation flow (QT) of the coolant flowing through the supercharger supply line 42 is reduced (QE> QT) from the circulation flow (QE) of the coolant flowing through the inside 1.
1 is fully opened (step S3). Then return.

In step S1, when the water temperature rises above the reference temperature (Y), it is determined whether or not the engine speed has risen to a high speed range (high speed) (step S4). Higher than high-speed rotation range (Y)
At this time, the control of step S2 is performed.

In step S4, when the motor has not risen to the high-speed rotation range (N), the electric motor 81 is energized (turned on) as shown in FIG. 3 (step S5). And
By controlling the amount of current supplied to the control valve 7, the engine supply line 4 is controlled.
The circulating flow rate (QT) of the cooling water flowing in the supercharger supply pipe 42 increases (QE <QT) from the circulating flow rate (QE) of the cooling water flowing in the inside 1 (step S6). Then, it is determined whether or not the engine is stopped (step S7).
When the engine is not stopped (N), the routine returns.

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

In step S9, when the predetermined time has elapsed (Y), the energization of the electric motor 81 is stopped (off).
(Step S10). Thereafter, the control ends.

The operation of the passenger car engine cooling apparatus 1 will be described with reference to FIG. When the engine 2 is started by turning on the key switch, the 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, when the temperature of the cooling water is lower than the reference temperature, and when the temperature of the cooling water is lower than the set temperature of the thermostat 43, the cooling water discharged from the main water pump 6 is supplied to the water jacket 21 of the engine 2, A circuit that returns to the main water pump 6 through the bypass line 44 is formed.

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

Further, when the engine load such as the vehicle speed, the throttle opening and the engine speed increases and the temperature of the cooling water in the water jacket 21 of the engine 2 rises,
The temperature of the sub water pump 8 is raised to a operable reference temperature or higher.

At this time, for example, when the engine speed is increasing to a high speed range, the circulation flow rate of the cooling water in the cooling water circuit 4 is large, and while the cooling performance of the radiator 5 has a margin, the sub water pump is provided. 8 itself becomes a resistor, and on the contrary, the total circulation flow rate in the cooling water circuit 4 decreases.

For this reason, the electric motor 81 of the sub water pump 8 is turned off, and the amount of electricity supplied to the control valve 7 is controlled to fully open the engine supply pipe 41, thereby suppressing the total resistance and cooling the engine 2 Ensure performance. In addition,
Even when the operation of the sub-water pump 8 is stopped, the cooling water flows into the supercharger supply pipe 42 by the discharge force of the main water pump 6, so that the radiator 5 as shown by the broken arrow in FIG. The low-temperature cooling water cooled by the above is forcibly circulated in the turbocharger 3. For this reason, 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 is reduced to the 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. I will. Therefore, the electric motor 81 is turned on and the sub water pump 8 is operated 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 circulation flow rate of the cooling water in the engine supply pipe 41: the circulation 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 coolant 2 flows to the engine 2. Circulating flow decreases.

Therefore, the cooling loss of the engine 2 is reduced by reducing the amount of heat received from the engine 2 in the cooling water, and the cooling performance of the engine 2 is improved by improving the cooling capacity of the radiator 5. The operation of the sub water pump 8 causes the cooling water to be supplied to the supercharger supply line 42.
The turbocharger 3 is sufficiently cooled, and each part is maintained at an appropriate temperature.

In the case where the engine 2 is stopped after the passenger car is driven under a high load (for example, when the engine 2 is stopped on a hill running at a low engine speed and a high engine speed,
Alternatively, when the engine 2 is stopped immediately after traveling at high speed), the turbocharger 3 may overheat and a malfunction may occur in the turbocharger 3.

At this time, when the electric motor 81 is turned on to control the amount of energization of the control valve 7, the sub-water pump 8 is operated for a fixed time, and the engine supply line 41 is fully closed, the broken line in FIG. Only the turbo cooling circuit indicated by the arrow is formed. For this reason, the cooling water discharged from the sub-water pump 8 passes through the turbocharger 3, cools each part of the turbocharger 3, is cooled by the radiator 5, and flows into the turbocharger 3 again.

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

When the sub water pump 8 is operated (when the engine is stopped), the control valve 7 for shutting off the flow of the cooling water into the engine 2 is a three-way valve. While the supply of the cooling water is stopped, the cooling water can be supplied to the heater core 9.

(Modification) In this embodiment, a turbocharger is used as an accessory, but a water-cooled alternator or the like may be used as an accessory. Either the auxiliary machine or the electric pump may be on the upstream side. Further, the electric fan 51 may be operated together with the sub water pump 8 after the engine is stopped.

[Brief description of the drawings]

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

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]

 DESCRIPTION OF SYMBOLS 1 Passenger car engine cooling device 2 Engine 3 Turbocharger (auxiliary equipment) 5 Radiator 6 Main water pump (water pump) 7 Control valve (three-way valve) 8 Sub water pump (electric pump) 9 Heater core 10 Control device (control means) ) 41 Engine supply line (first line) 42 Supercharger supply line (second line) 45 Heater supply line (third line)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F01P 7/16 501 F01P 3/20 F02B 39/00

Claims (1)

(57) [Claims] (A) a water-cooled engine mounted on a vehicle; (b) a radiator for cooling a cooling water of the engine; and (c) a radiator between an outflow side of the radiator and an inflow side of the engine. A water pump, which is connected to the engine and forcibly circulates cooling water flowing out of the radiator by being driven by the engine and flowing out of the radiator; (E) a second conduit connected in parallel with the engine and connecting the outflow side of the water pump and the inflow side of the radiator; and (f) the second pipeline. (G) an electric pump provided in the second conduit, forcibly circulating cooling water flowing out of the radiator to the auxiliary device, and (h) an electric pump provided in the second conduit . Downstream of the first pipe
From the outflow side of the engine and the water pon
A third pipe connecting the inlet side of the pump and (i) a cooling water and indoor air provided in the third pipe.
(J) a heater core provided at a branch point between the first conduit and the third conduit;
And the flow rate of the cooling water to the first pipe and the third pipe.
(K) at least after stopping the engine, the electric pump
While operating the three-way valve,
An engine cooling device comprising: a control unit configured to block a flow of cooling water into an engine.