JP2014101876A - Engine system including thermostat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine system including a thermostat capable of minimizing energy released to the external through cooling water and reducing fuel consumption by variably controlling a temperature of the cooling water to operate the thermostat according to a load of the engine and an outside air temperature.SOLUTION: An engine system including a thermostat includes an engine generating torque, a cooling water temperature sensor detecting a temperature of cooling water circulated in the engine, an atmospheric air temperature sensor detecting an atmospheric air temperature, a thermostat disposed in a cooling water line to convert a flow channel of cooling water, a driving portion disposed in the thermostat to convert the flow channel of the cooling water by utilizing supplied electric power, and a control portion for variably controlling the cooling water temperature to operate the driving portion according to the cooling water temperature and the atmospheric air temperature respectively output from the cooling water temperature sensor and the atmospheric air temperature sensor.

Description

  The present invention relates to an engine system equipped with a thermostat. More specifically, the cooling water flow path is switched according to the temperature of the circulating cooling water to prevent overheating, and the cooling water temperature is actively controlled. The present invention relates to an engine system equipped with a thermostat.

  The automotive thermostat is installed between the engine and the radiator, and is automatically opened and closed according to the temperature change of the cooling water, while maintaining the cooling water in the set temperature range by adjusting the flow rate flowing to the radiator. . In the mechanical thermostat, the wax expands depending on the temperature of the cooling water, and the piston causes the valve to open and close by such expansion force. Such a mechanical thermostat is a system that operates according to an opening / closing temperature set to a specified temperature, and is a system that simply opens and closes a valve only at a predetermined temperature, and changes in the traveling environment and conditions of the vehicle. I cannot deal with it positively.

  An electronic thermostat is disclosed for maintaining the temperature of engine coolant in an optimum state while complementing the disadvantages of a mechanical thermostat. Such an electronic thermostat can maintain the optimum cooling water temperature by actively controlling the cooling water temperature of the engine in accordance with the driving environment such as the load state of the vehicle. Compared to a thermostat, it can be expected to improve fuel efficiency and reduce exhaust gas.

  To open and close the thermostat valve, a temperature sensitive but electronically active drive is applied, such as wax, semi-fluid, rubber piston, backup plate, and main Includes pistons.

  On the other hand, the temperature of the cooling water at which the thermostat operates is fixed. By operating regardless of the engine load and the temperature of the outside air, energy is wasted through the cooling water, which may increase fuel consumption.

JP 2007-170236 A

  The present invention has been made in view of the above problems, and an object of the present invention is to consider the engine load state and the temperature of the outside air in varying the temperature of the cooling water at which the thermostat operates. Another object of the present invention is to provide an engine system including a thermostat capable of reducing energy wasted to the outside through cooling water.

  In order to achieve the above object, an engine system including a thermostat according to the present invention is provided to detect an atmospheric temperature, an engine for generating a rotational force, a cooling water temperature sensor for detecting a cooling water temperature circulating through the engine, and an atmospheric temperature. An air temperature sensor, a thermostat arranged in the cooling water line so as to change the flow path of the cooling water, and provided in the thermostat so as to change the flow path of the cooling water using a supplied power source. It includes a drive unit, and a control unit that variably controls the coolant temperature at which the drive unit operates according to the coolant temperature and the ambient temperature sent from the coolant temperature sensor and the ambient temperature sensor.

  In the engine system including such a thermostat, the engine system further includes a cooling fan disposed on one side of the radiator, and the control unit is configured to change the cooling water temperature and the atmospheric temperature from the cooling water temperature sensor and the atmospheric temperature sensor according to the cooling water temperature and the atmospheric temperature. It is preferable to variably control the operation point of the cooling fan. It is preferable that the control unit determines the load of the engine using the operation information of the engine and classifies the load of the engine into a low load, a medium load, and a high load. It is preferable that the control unit variably controls the temperature of the cooling water at which the drive unit operates according to the load of the engine. It is preferable that the temperature of the cooling water at which the drive unit operates decreases as the engine load increases. It is preferable that the temperature of the cooling water at which the drive unit operates increases as the engine load decreases. Moreover, it is preferable that the temperature of the cooling water in which the drive unit operates increases as the atmospheric temperature decreases. And it is preferable that the temperature of the cooling water which the said drive part operates becomes low, so that the said atmospheric temperature becomes high.

  An engine system having a thermostat according to the present invention minimizes the energy released to the outside through the cooling water by variably controlling the temperature of the cooling water at which the thermostat operates according to the engine load and the temperature of the outside air. Thus, fuel consumption can be reduced. Therefore, fuel consumption can be reduced, exhaust gas quality can be further improved, and energy consumption for operating a cooling fan that blows air to the radiator can be reduced.

It is a block diagram which shows an example of schematic structure of the engine system provided with the thermostat by this invention. It is a graph which shows an example of the characteristic which the thermostat by this invention operate | moves according to the temperature of a cooling water. It is a table | surface which shows an example of the characteristic which the thermostat by this invention operate | moves according to the temperature of a cooling water, and the load of an engine. 4 is a flowchart illustrating an example of a method for controlling a thermostat according to the present invention.

  Hereinafter, examples as preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, components are described and explained, and other components not described in the drawings refer to well-known techniques well known to those skilled in the art, and descriptions thereof are omitted. To do.

  A schematic configuration of an engine system including a thermostat according to the present embodiment is shown in FIG. Referring to FIG. 1, the engine system includes a thermostat, an engine 190, a radiator 194, an outside air temperature sensor 180, a cooling water temperature sensor 192, a cooling fan 196, and a control unit 200. The thermostat includes: The heater 100, the wax 110, the main piston 120, the valve guide 130, the main valve 140, the bypass valve 150, and the elastic member 160 are included.

  At the same time, the thermostat has a main inlet passage 170 connected to the radiator 194 at the top, and a bypass passage 172 connected to the coolant outlet of the engine 190 at the bottom. Is formed with a main outlet channel connected to the cooling water inlet of the engine 190.

  The elastic member 160 elastically supports the valve guide 130 upward, the main valve 140 blocks the main inlet channel 170, and the bypass valve 150 opens the bypass channel 172.

  The control unit 200 controls the operation of the thermostat using signals sent from the outside air temperature sensor 180, the engine 190, and the coolant temperature sensor 192.

  The outside air temperature sensor 180 senses the temperature of the outside air of the vehicle and transmits it to the control unit 200. The control unit 200 senses the load state using the operating conditions of the engine 190. At the same time, the cooling water temperature sensor 192 detects the temperature of the cooling water and transmits it to the control unit 200.

  The controller 200 variably controls the temperature of the cooling water at which the thermostat operates using the detected operating conditions (cooling water temperature, outside air temperature, load state, etc.).

  More specifically, when the control unit 200 supplies power to the thermostat heater 100 through a power unit (not shown), the wax 110 is heated and expands. The expanded wax 110 pushes the main piston 120 downward.

  Therefore, the main valve 140 opens the main inlet flow path 170 and the bypass valve 150 blocks the bypass flow path 172 so that the cooling water passes through the radiator 194 and is cooled.

  Here, a cooling fan 196 is disposed adjacent to the radiator 194 to assist cooling of the cooling water. The controller 200 can variably operate the cooling fan 196 using a clutch.

  The driving unit for operating the thermostat includes the heater 100, the wax 110, and the main piston 120. The control unit 200 controls the power applied to the heater 100 to actively control the thermostat. In this embodiment, the thermostat operates according to the temperature of the surrounding cooling water and the temperature of the heater 100.

  FIG. 2 is a graph illustrating characteristics of the thermostat according to the present embodiment that operates according to the temperature of the cooling water. Referring to FIG. 2, the horizontal axis represents the temperature of the cooling water, and the vertical axis represents the lift (lift amount) at which the valve guide 130 is lifted.

  “Up” and “down” indicate the amount of lift due to the temperature of the cooling water in a state where power is not supplied to the driving unit of the thermostat, that is, the heater 100.

  “75 degree power source” indicates an amount by which power is applied to the heater 100 and the valve guide 130 is lifted by the driving unit when the temperature of the cooling water is 75 degrees.

  “80-degree power supply” indicates an amount by which power is applied to the heater 100 and the valve guide 130 is lifted by the drive unit when the temperature of the cooling water is 80 degrees.

  “85 degree power source” indicates an amount by which power is applied to the heater 100 and the valve guide 130 is lifted by the drive unit when the temperature of the cooling water is 85 degrees.

  “90 degree power source” indicates an amount by which power is applied to the heater 100 and the valve guide 130 is lifted by the driving unit when the temperature of the cooling water is 90 degrees.

  FIG. 3 is a table showing characteristics in which the thermostat according to the present embodiment operates in accordance with the temperature of the cooling water and the engine load. Referring to FIG. 3, the operating temperature of the thermostat according to the atmospheric temperature in the high load state, the medium load state, and the low load state of the engine 190 is shown.

  More specifically, the control unit 200 determines whether the engine 190 is in a high load state, a medium load state, or a low load state using the operating conditions of the engine 190. Here, the control unit 200 can determine the load state by measuring the RPM and the fuel injection amount.

  When the engine 190 is in a high load state and the atmospheric temperature is 35 degrees, the thermostat starts to operate at a cooling water temperature of 90 degrees, and when the atmospheric temperature is 15 degrees, the thermostat indicates the temperature of the cooling water. Starts to work at 96 degrees.

  When the atmospheric temperature is 35 degrees in the middle load state of the engine 190, the thermostat starts to operate at a cooling water temperature of 95 degrees, and when the atmospheric temperature is 15 degrees, the thermostat indicates the temperature of the cooling water. Starts to work at 97 degrees.

  When the engine 190 is under a low load and the atmospheric temperature is 35 degrees, the thermostat starts to operate at a cooling water temperature of 100 degrees, and when the atmospheric temperature is 15 degrees, the thermostat is the temperature of the cooling water. Starts to work at 103 degrees.

  In the present embodiment, an antifreeze is added to the cooling water, and since the pressure is higher than the atmospheric pressure in a sealed space, it does not boil even at 100 degrees or more.

  FIG. 4 is a flowchart illustrating a method for controlling a thermostat according to the present embodiment. Referring to FIG. 4, first, the control unit 200 determines the load of the engine 190 (S400). The load of engine 190 can be determined by a set program or method through data collected during a set time.

  The controller 200 senses the outside air temperature in real time using the outside air temperature sensor 180 (S410). Then, the control unit 200 detects the temperature of the cooling water from the cooling water temperature sensor 192, and sets the temperature of the cooling water at which the thermostat operates (S420).

  Therefore, by variably controlling the temperature of the cooling water at which the thermostat operates according to the engine load and the temperature of the outside air, the energy released to the outside through the cooling water is minimized and the fuel consumption is reduced. be able to. At the same time, energy consumption for operating a cooling fan that blows air to the radiator can be reduced. As mentioned above, although the Example as preferable embodiment regarding this invention was demonstrated, this invention is not limited to the said Example, The person who has the normal knowledge in the technical field to which the said invention belongs from the Example of this invention. Includes all modifications within the scope that are easily modified and found to be equal.

DESCRIPTION OF SYMBOLS 100 Heater 110 Wax 120 Main piston 130 Valve guide 140 Main valve 150 Bypass valve 160 Elastic member 170 Main inlet flow path 172 Bypass flow path 180 Outside air temperature sensor 190 Engine 192 Cooling water temperature sensor 194 Radiator 196 Cooling fan 200 Control part

Claims (8)

An engine that generates torque,
A coolant temperature sensor for sensing the coolant temperature circulating through the engine;
An atmospheric temperature sensor provided to detect the atmospheric temperature,
A thermostat arranged in the cooling water line so as to change the flow path of the cooling water;
A drive unit provided in the thermostat so as to change the flow path of the cooling water using the supplied power;
And a control unit that variably controls the cooling water temperature at which the driving unit operates according to the cooling water temperature and the atmospheric temperature sent from the cooling water temperature sensor and the atmospheric temperature sensor. Engine system. A cooling fan disposed on one side of the radiator;
The controller is
2. The engine system having a thermostat according to claim 1, wherein an operation time point of the cooling fan is variably controlled according to a coolant temperature and an ambient temperature sent from the coolant temperature sensor and the ambient temperature sensor. 3. . The control unit determines the load of the engine using operation information of the engine,
The engine system with a thermostat according to claim 1, wherein the engine load is classified into a low load, a medium load, and a high load.   The engine system with a thermostat according to claim 3, wherein the control unit variably controls the temperature of cooling water in which the drive unit operates according to a load of the engine.   The engine system with a thermostat according to claim 4, wherein the temperature of the cooling water at which the drive unit operates becomes lower as the load on the engine increases.   The engine system with a thermostat according to claim 4, wherein the temperature of the cooling water at which the drive unit operates increases as the load on the engine decreases.   The engine system with a thermostat according to claim 1, wherein the temperature of the cooling water at which the drive unit operates increases as the atmospheric temperature decreases.   The engine system having a thermostat according to claim 1, wherein the temperature of the cooling water at which the drive unit operates becomes lower as the atmospheric temperature becomes higher.

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