KR100906847B1 - An engine cooling system and the cooling method thereof - Google Patents

Abstract

The present invention relates to an engine variable separation cooling system of a vehicle,

The conventional variable block cooling method using a mechanical block thermostat has problems such as bore deformation and piston noise due to excessive increase in the cylinder block temperature during rapid acceleration in a state in which the main thermostat variation is small. In case of applying the stat, there was a problem that the engine knocked down due to the instantaneous acceleration of the vehicle under the high engine coolant temperature, resulting in halved fuel efficiency and performance degradation.

The solenoid valve 40 is mounted on the outlet side 22 of the cylinder block 20 (CYL / BLK) which is cooled separately from the cylinder head 10 (CYL / HEAD), and connected to the electronic control unit 50 (ECU). According to the present invention characterized in that the opening and closing according to the operating conditions it is possible to smoothly control the block cooling water temperature through the solenoid valve and its operating logic, high cooling water during rapid acceleration by only controlling the cylinder block cooling water temperature high Since there is no perception of ignition timing due to the temperature, the effect of maximizing the performance or fuel efficiency can be obtained.

Variable Variable Cooling Engine, Cylinder Block, Solenoid Valve, Electronic Control Unit

Description

Variable engine cooling system of vehicle {an engine cooling system and the cooling method

1 is a block diagram of a variable separation cooling method using a conventional mechanical block thermostat

Figure 2 is a longitudinal cross-sectional view of Behr's electronically controlled thermostat

Figure 3 is a longitudinal sectional view of the step motor type electronically controlled thermostat of INZI Corporation

4 is a graph showing the head of the electronically controlled thermostat

5 is a graph showing a cooling water temperature drop pattern during the transition from low load to high load

6 is a block diagram of one embodiment of the present invention

7 is a longitudinal sectional view of main parts of the embodiment;

Fig. 8A is a longitudinal sectional view of a main portion of the cylinder block outlet side sealed state in the embodiment;

Fig. 8B is a longitudinal sectional view showing main parts of the cylinder block outlet side in an open state of the embodiment;

9 is an input and output configuration diagram of the solenoid valve operating logic of the embodiment;

10 is a control flow diagram of the solenoid valve basic operation logic of the embodiment;

11 is a control map state diagram of the solenoid valve operating logic of the embodiment;

12 is a control flow diagram of a solenoid valve operating logic for improving fuel efficiency of the embodiment.

Figure 13 is a control flow diagram of the solenoid valve operation logic for improving the heating performance of the embodiment

14 is a control flow diagram of a solenoid valve operating logic for improving knocking of the embodiment;

Explanation of symbols on the main parts of the drawings

10: cylinder head 20: cylinder block

22: outlet side 40: solenoid valve

41 valve body 42 plunger

43: blocking valve 44: spring

50: electronic control unit

The present invention relates to an engine variable separation cooling system of a vehicle, and more particularly, to a solenoid valve mounted on an outlet side of a cylinder block and connected to an electronic control unit (ECU) to open and close according to driving conditions. will be.

In general, the engine cooling system absorbs high temperature heat generated from the combustion chamber, maintains the metal surface temperature around the combustion chamber at a constant level, ensures engine durability, and sends sufficient flow to the radiator and heater in connection with the vehicle's heating and cooling performance. Play the role.

There are various methods of cooling the engine. Among them, a method of improving the fuel economy of the engine is to control the cooling water temperature of the cylinder block variably and to control the entire engine cooling water temperature using the electronically controlled thermostat according to the engine operating conditions. There is a way.

In the variable separation cooling method using the mechanical block thermostat, the outlet side of the cylinder block 20 in a method of separately cooling the cylinder head 10 (CYL / HEAD) and the cylinder block 20 (CYL / BLK) as shown in FIG. The mechanical block thermostat (30) is additionally installed in this case, and the modification temperature of the mechanical block thermostat (30) additionally mounted is usually set to be opened at a temperature higher than a commonly used 82 ° C thermostat. to be.

Therefore, in a low load operation condition such as a general driving situation, the cylinder block coolant flow is stagnant with the mechanical block thermostat 30 closed, so that the coolant temperature of the cylinder block 20 is controlled to be high, and thus the cylinder block 20 Fuel economy is improved by reducing friction.

On the other hand, under high load operating conditions such as climbing, the mechanical block thermostat 30 mounted on the cylinder block 20 is opened together with the increase in the cooling water temperature, thereby maintaining the cylinder block 30 coolly, thereby ensuring the reliability of the engine. .

However, the engine variable separation cooling method using the mechanical block thermostat 30 has the following problems.

That is, since the mechanical block thermostat 30 is generally slow in response, the engine block may be degraded since the cylinder block 20 is still kept hot under operating conditions such as rapid acceleration (a section in which the main thermostat is less variable), As a result, the temperature of the cylinder block 20 rises excessively, causing deformation of the cylinder block bore and piston noise.

In addition, since the cylinder block coolant temperature is changed at 95 ° C, it is impossible to obtain additional fuel efficiency gains due to the cooling water temperature optimization, and in particular, when the mechanical block thermostat 30 mounted on the cylinder block 20 is broken, in particular, a closed stuck In this case, the cylinder block 20 may be overheated, and the mechanical block thermostat 30 mounted on the cylinder block 20 is closed when the vehicle warms up, and thus the flow resistance of the engine (pressure difference between the engine inlet and outlet) increases. There is a problem that the heater flow rate is reduced and the heating performance is deteriorated.

Meanwhile, the electronic thermostat developed to improve the fuel efficiency of the engine and the vehicle by supplementing the disadvantages of the mechanical block thermostat is the MCT (Map Controlled Thermostat) for each developer (Behr-Thopmson, INZI Controls, Wahler, etc.). ), AET (Adjustable Electric Thermostat) is different, but in the end, it is the same device in terms of adding electric and mechanical devices to the mechanical block thermostat to control according to the vehicle status.

2 is a longitudinal sectional view of Behr's electronically controlled thermostat, and FIG. 3 is a longitudinal sectional view of an INZI's step motor type electronically controlled thermostat.

The electronically controlled thermostat improves the fuel economy by controlling the coolant temperature high in the low thermal load state of the vehicle, and improves the fuel economy, and controls the coolant temperature low in the thermal high load state such as climbing conditions, trailer towing conditions or rapid acceleration. It is a device that seeks stability.

Basically, the opening temperature of the wax in the electronically controlled thermostat is set to 100 ° C or higher, so the engine outlet temperature is controlled 15 ~ 20 ° C higher than the existing 82 ° C thermostat.

In normal driving conditions, the temperature of the coolant is controlled only by wax, but the head of the valve is increased by operating the heater or step motor mentioned above only when the heat load of the vehicle is severe.

Therefore, the head of the electronically controlled thermostat has two different curves as shown in FIG. 4, and when the heater or the step motor is operated as shown in FIG. 4, the head of the electronic thermostat can be seen to have a large head at the same temperature.

FIG. 5 is a graph showing a pattern in which the coolant temperature decreases when the electronically controlled thermostat is operated and starts controlling at the same temperature as a general mechanical thermostat. Referring to FIG. 5, the coolant within about 5 seconds when the step motor type is applied. It lowers by 20 degreeC.

However, the electronically controlled thermostat has the disadvantage of reducing the engine fuel efficiency and performance by increasing the amount of ignition timing due to knocking of the engine during the time of dropping the total coolant temperature under the same conditions as the rapid acceleration of the vehicle.

This is because the knocking performance of the engine is deteriorated because the electronically controlled thermostat has to change the engine coolant temperature.

The present invention has been made in view of the conventional situation as described above, the object is to compensate for the disadvantages of the variable separation cooling method employing a conventional mechanical block thermostat and the cooling water temperature control method using an electronically controlled thermostat to improve the fuel economy effect It is to provide a variable engine cooling system of a new concept of maximizing the vehicle.

Hereinafter, the specific technical details of the present invention will be described in more detail with reference to the accompanying drawings.

That is, FIG. 6 is a block diagram of one embodiment of the present invention, Figure 7 is a longitudinal cross-sectional view of the main part of the embodiment bar, the engine variable separation cooling system of the present invention is a cylinder head (10) as shown in FIG. The solenoid valve 40 is mounted on the outlet side 22 of the cylinder block 20 (CYL / BLK) that is cooled separately from the CYL / HEAD, and connected to the electronic control unit 50 (ECU) according to the operating conditions. It can be opened and closed.

In the illustrated embodiment, the solenoid valve 40 has a blocking valve 43 elastically supported by a spring 44 at the tip of the plunger 42 which is movably installed in the valve body 41 in a lateral direction as shown in FIG. 7. It has a form to be mounted.

In the present invention, the solenoid valve 40 is connected to the electronic control unit 50 (ECU), and if the engine is determined to be low, the electronic control unit (ECU) extends the plunger 42 of the solenoid valve 40. As the blocking valve 43 seals the outlet side 22 of the cylinder block 20 as shown in FIG. 8A, the cylinder block 20 maintains a high temperature.

In the above, when the blocking valve 43 seals the outlet side 22 of the cylinder block 20, the spring 44 which elastically supports the blocking valve 43 has a blocking valve 43 cooling the cylinder block 20. It is kept slightly compressed so that it does not open to water pressure.

On the other hand, when the engine is under heavy load such as sudden acceleration or climbing, the electronic control unit (ECU) retracts the plunger 42 of the solenoid valve 40 as shown in FIG. 8B so that the blocking valve 43 is the outlet side of the cylinder block 20. By opening 22, the cylinder block 20 is kept cold.

As such, in the present invention, when the vehicle is operated in a state in which the outlet side 22 of the cylinder block 20 is sealed with the blocking valve 43 of the solenoid valve 40, the cooling water temperature of the cylinder block 20 can be increased. It is possible to improve the fuel economy of the engine, it is possible to control the heating performance and knocking as well by opening and closing the blocking valve 43 according to the engine operating conditions.

In the present invention, the operation of the solenoid valve 40 is applied to the electronic control unit 50 (ECU) that receives input signals such as engine speed (RPM), engine torque (Torque), cooling water temperature, vehicle speed, air conditioner operation, and compressor pressure. Controlled by the electronic control unit 50 outputs an output signal related to solenoid valve 40 control, heating performance control, knocking control, fuel economy improvement, and the like.

9 shows an input and output configuration diagram of the solenoid valve operating logic of the present invention, and FIG. 10 shows an operation flow diagram of the solenoid valve operating logic.

In the present invention, the electronic control unit 50 reads the data values input through various sensors and then retrieves the actual heating performance requirements from the HVEC operating section to release the application of the solenoid valve for the cylinder block coolant flow control. It improves heating performance, improves fuel economy by setting threshold and transition area by applying solenoid valve for flow control of cylinder block coolant, and improves fuel efficiency by searching knocking area in solenoid valve operation section. The knocking is improved by releasing the control solenoid valve.

For example, the basic control of the solenoid valve for improving fuel efficiency may be driven by two maps as shown in FIG. 11.

In FIG. 11, region 0 represents solenoid valve closing, region 1 represents solenoid valve operation, and region 2 represents a transition region.

In other words, when the solenoid valve is operated and opened, the cylinder block cooling water flow rate is increased to reduce the heat load of the engine. The factor is fuel efficiency improvement through control by engine speed, engine load, cooling water temperature, and vehicle speed, and engine rotation. Knocking becomes more frequent as the number and engine load increase, so the solenoid valve operating range is lowered.

 On the other hand, the relationship between vehicle speed and cooling water temperature is applied in reverse, which takes into account the vehicle speed and cooling water temperature during climbing.

On the other hand, the solenoid valve opens too frequently and forms a transition region to prevent the closing phenomenon, and in the transition region, the hysteresis concept is introduced to reduce the fatigue of the solenoid valve to improve durability.

In the transition region, the upper value is applied when changing from the low state to the high state, but the lower value is applied when moving from the high state to the low state.

For example, if the solenoid valve is operated (stopped) at 3500 rpm and the 500 RPM range is set to the transition zone, the solenoid valve release will occur at the moment of falling below 3000 RPM.

This transition zone application is applied in the same way to the engine load, cooling water temperature and vehicle speed which are the basic input elements of the solenoid valve control logic.

12 is an operation flowchart of a solenoid valve operation control logic for improving fuel efficiency when a transition region is applied.

If the engine is not in the OFF state as shown in FIG. 12, after reading the heating performance, the cooling water temperature (A), the vehicle speed (B), the engine RPM (C), and the engine load (D) are read, If it is bigger than), the solenoid valve is operated. If any one of each input value is not greater than the threshold, the solenoid valve is stopped.

On the other hand, when the solenoid valve is closed, operating the Cabin Heater (Cabin Heater) will lower the heating performance than when the cylinder block coolant flows smoothly (open solenoid valve).

13 is a flow chart of the control logic to compensate for this disadvantage.

13 is a basic concept of the control logic is to improve the fuel economy in other operating conditions, except for the environment that requires the driver to switch on the HVEC heating environment, and the related factors are cooling water temperature, outside air temperature, The main point is the air conditioner switch, air conditioner compressor pressure, and selectively operate the solenoid valve according to the vehicle speed condition.

The control logic performs the basic logic of FIG. 11 when the cooling water temperature (A) is greater than the thermostat (T / S) opening temperature, and the outside air temperature when the cooling water temperature (A) is less than the thermostat (T / S) opening temperature. Check if (B) is greater than the standard temperature, if the outside temperature (B) is less than the standard temperature, it is determined whether the air conditioner switch (C) is On, or if the air conditioner switch (C) is on, It is judged whether it is larger than the middle and the vehicle speed E is higher than the high speed, and if the switch F of the environmental air conditioning system HVEC is not off, the solenoid valve is operated.

In addition, even when the air conditioner switch (C) is not on, the solenoid valve is operated unless the switch (F) of the environmental air conditioning apparatus (HVEC) is off.

Figure 14 shows the control flow diagram of the solenoid operation logic when knocking occurs in the present invention.

In the above-described solenoid valve basic operation logic, the solenoid valve is operated to circulate the coolant of the cylinder block by activating the solenoid valve, but the knocking generated in the actual vehicle is more complicated, so the operation logic of FIG. By minimizing knocking through, it can improve fuel economy and maintain stable performance.

In the knocking operation, the solenoid operation logic reads the vehicle speed (A), the intake temperature (B), the exhaust temperature (C), and the outside air temperature (D), and then the vehicle speed (A) is smaller than the set value and the intake temperature (B) and exhaust temperature (C). ), If the outside temperature (D) is greater than the set value, operate the solenoid valve. Otherwise, operate the solenoid when the air conditioner switch (E) is on and the air conditioner pressure (F) is greater than the middle to open the cylinder block coolant flow path. .

As described above, in the present invention, the solenoid valve 40 is mounted on the outlet side 22 of the cylinder block 20 (CYL / BLK) which is cooled separately from the cylinder head 10 (CYL / HEAD), and the electronic control unit (50; ECU) to be opened and closed according to the operating conditions, the conventional variable block cooling method using a mechanical block thermostat, the cylinder block temperature is excessively increased during rapid acceleration in the state that the main thermostat change amount is small The bore deformation and piston noise is generated, but according to the present invention, it is possible to smoothly control the block cooling water temperature through the solenoid valve and its operation logic.

In addition, when the electronically controlled thermostat is applied, the engine knocks down in an instantaneous acceleration state of the vehicle in a state where the total coolant temperature of the engine is high, resulting in half the fuel efficiency effect and a decrease in performance. Therefore, there is no perception of the ignition timing due to the high cooling water temperature during rapid acceleration, so that the effect of maximizing performance or fuel efficiency can be obtained.

Claims (10)

delete delete delete delete delete delete delete The solenoid valve 40 is mounted on the outlet side 22 of the cylinder block 20 (CYL / BLK) which is cooled separately from the cylinder head 10 (CYL / HEAD), and connected to the electronic control unit 50 (ECU). In constructing an engine variable separation cooling system of a vehicle that can be opened and closed according to driving conditions, The operation of the solenoid valve 40 is controlled by an electronic control unit 50 (ECU) which receives an input signal such as engine speed (RPM), engine torque (Torque), cooling water temperature, vehicle speed, air conditioner operation, compressor pressure, and the like. and, The electronic control unit 50 outputs an output signal related to the solenoid valve 40 control, heating performance control, knocking control, fuel efficiency improvement, and the like, and reads data values input through various sensors, and then, an environmental air conditioning apparatus (HVEC). Search the actual heating performance requirement in the operating section to release the cylinder block coolant flow control solenoid valve to improve heating performance, and apply the cylinder block coolant flow control solenoid valve to set the threshold and transition area. By improving fuel economy, by searching for the area where knocking occurs in the solenoid valve operating section, by canceling the application of the cylinder block coolant flow control solenoid valve, the knocking property is improved. If the coolant temperature is lower than the thermostat opening temperature, check if the outside air temperature is higher than the standard temperature.If the outside air temperature is lower than the standard temperature, determine whether the air conditioner switch is on. The engine variable separation cooling system of the vehicle, characterized in that the solenoid valve is operated if the switch of the environmental air conditioning apparatus is not turned off by determining whether it is larger than the set high speed. 9. The variable engine cooling system of claim 8, wherein the solenoid valve is operated even if the air conditioner switch is not turned on unless the environmental air conditioner switch is turned off. The solenoid valve 40 is mounted on the outlet side 22 of the cylinder block 20 (CYL / BLK) which is cooled separately from the cylinder head 10 (CYL / HEAD), and connected to the electronic control unit 50 (ECU). In constructing an engine variable separation cooling system of a vehicle that can be opened and closed according to driving conditions, The operation of the solenoid valve 40 is controlled by an electronic control unit 50 (ECU) which receives an input signal such as engine speed (RPM), engine torque (Torque), cooling water temperature, vehicle speed, air conditioner operation, compressor pressure, and the like. and, The electronic control unit 50 outputs an output signal related to the solenoid valve 40 control, heating performance control, knocking control, fuel efficiency improvement, and the like, and reads data values input through various sensors, and then, an environmental air conditioning apparatus (HVEC). Search the actual heating performance requirement in the operating section to release the cylinder block coolant flow control solenoid valve to improve heating performance, and apply the cylinder block coolant flow control solenoid valve to set the threshold and transition area. By improving fuel economy, by searching for the area where knocking occurs in the solenoid valve operating section, by canceling the application of the cylinder block coolant flow control solenoid valve, the knocking property is improved. After reading the vehicle speed, intake temperature, exhaust temperature, and outside air temperature, operate the solenoid valve if the vehicle speed is lower than the set value and the intake temperature, exhaust temperature, and outside temperature is higher than the set value. Otherwise, the air conditioner switch is on and the air condition pressure is Operating the solenoid to open the cylinder block cooling water flow path.

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