KR101033317B1 - Method for controlling thermostat, and thermostat implementing the same - Google Patents

Abstract

The present invention relates to a thermostat control method and a thermostat implementing the same. The present invention relates to a thermostat connected to an engine side, a heater side, and a bypass side, respectively, comprising: a housing, a central body located in the center of the housing, The bypass valve is formed at the lower end of the center body to move up and down and open and close the bypass side passage, and is formed of a structure surrounding the outer circumferential surface of the center body, elastic member for supporting the bypass valve in a carbon, the upper end of the housing It is fixedly positioned, and includes a first electromagnet that generates magnetism when a current is applied, and a second electromagnet that is attached to an upper end of the bypass valve and generates magnetism when a current is applied. According to the present invention, the temperature of the cooling water is controlled by using a thermostat, and thus, the engine temperature is adjusted to easily control the ignition and combustion even under the high speed and high load of the engine.

Thermostat, electromagnet, bypass, engine, HCCI, ECU, sermostat, coolant temperature.

Description

Thermostat control method and thermostat implementing the same {Method for controlling thermostat, and thermostat implementing the same}

The present invention relates to a thermostat control method and a thermostat implementing the same, and more particularly, a thermostat control method and a thermostat for embodying the same by controlling the thermostat in a vehicle to precisely control the ignition and combustion of the engine. It's about stats.

With the recent environmental pollution and fuel depletion issues, the emission and fuel economy development items have become an important part in vehicle development. In order to improve these parts, systems and engines different from existing vehicles are being developed. For example, GID engine, ISG, power generation control, HCCI engine.

The Homogeneous Charge Compression Ignition (HCCI) engine is a premixed compression ignition engine that is designed to reduce fuel consumption, while reducing major emissions, HC, CO, NOx and PM. HCCI engines, like gasoline engines, have a good mix of fuel and air and are drawn into the cylinders. Since HCCI engine is well mixed with fuel and air and burns, the particulate matter (PM) is hardly generated, and there is no loss caused by throttle like a diesel engine, so it is advantageous to achieve high efficiency. In addition, unlike the gasoline engine or the diesel engine, HCCI engine combustion occurs in the entire combustion chamber, so the combustion temperature is lower than the existing system, thereby reducing the NOx emission.

This HCCI engine has a disadvantage in that ignition and combustion are not free because, unlike conventional engines, combustion of the engine starts from the spontaneous combustion of the mixer and the spontaneous combustion is most affected by the compression temperature of the mixer. The compression temperature of the mixer is particularly high when the engine is driven in a high speed high load region, leading to rapid spontaneous spontaneous combustion, thus causing problems such as NOx emissions and high speed high load output degradation.

Attempts have been made to improve ignition and combustion characteristics in conventional HCCI engines. It was mainly intended to be improved by adding external hardware and software. Representative examples include an exhaust circulation system (EGR) and a change in compression ratio by variable valve timing. The exhaust circulation device (EGR) sucks the discharged gas back into the cylinder. The discharged gas is sucked back into the cylinder to lower the temperature to control the ignition timing and combustion at high temperature and high load. In addition, the control method by the variable valve timing determines the operating range of the HCCI engine, and rapidly changes the intake / exhaust valve timing at high speed and high loads to instantaneously control the compression pressure and to re-induce the exhaust gas that has been burned out by the exhaust port. This is to control the ignition and combustion of the engine. However, this conventional method has to add a new device, there are problems such as cost increase and engine shape change.

On the other hand, in the normal engine is provided with a thermostat that is installed in the outlet or inlet of the coolant to automatically open and close the passage in accordance with the change in the coolant temperature circulating the water jacket inside the engine to maintain a constant cooling water temperature. The thermostat is a valve that operates automatically according to the coolant temperature. It is installed at the outlet of the radiator of the cylinder head. When the coolant temperature is low, the valve closes to prevent the coolant from entering the radiator and increases the temperature in the water jacket. When the temperature of the coolant is high, the valve opens to allow the coolant to circulate and radiate.

The present invention has been made to solve the above problems, a thermostat control method and a thermostat for implementing the same to precisely control the ignition and combustion of the engine using the thermostat at high speed high load of the engine The purpose is to provide.

The present invention for achieving the above object is a thermostat connected to the engine side, the heater side and the bypass side, respectively, the housing, the central body located in the center of the housing, formed on the lower end of the central body and move up and down The bypass valve is formed to open and close the bypass side passage, the structure surrounding the outer circumferential surface of the central body is formed, the elastic member for elastically supporting the bypass valve, is fixed to the upper end of the housing, the magnetic when the current is applied The first electromagnet for generating a, and the second electromagnet attached to the upper end of the bypass valve for generating a magnetism when the current is applied.

The first electromagnet and the second electromagnet are respectively enclosed in a coil connected to an ECU (Electronic Control Unit), and may generate magnetism when a current is applied to the coil under control of the ECU.

If it is determined that the engine state is a high speed, high load region, the ECU may apply a current to the coil so that the magnets attracting the first and second electromagnets are generated.

The ECU may determine that the engine state is a high speed, high load region when the rate of change of the coolant temperature exceeds the first reference value. In this case, after determining that the engine state is a high speed high load region, the ECU may stop supplying the current applied to the coil when the rate of change of the cooling water temperature is less than the second predetermined reference value.

In the present invention, the thermostat control method is a change rate calculation step of calculating the cooling water temperature change rate by monitoring the cooling water temperature when the engine is turned on (on), the first reference value by checking whether the cooling water temperature change rate exceeds a predetermined first reference value If exceeded, a thermostat opening step of controlling the thermostat to open the conduit connected to the thermostat.

In one embodiment of the present invention, after the step of opening the thermostat, checking whether the cooling water temperature reaches a target value, checking whether the cooling water temperature change rate is less than a second predetermined reference value when the cooling water temperature reaches a target value, and cooling water temperature. If less than the second predetermined reference value may further include a thermostat closing step of controlling the thermostat so that the conduit connected to the thermostat is closed.

In one embodiment of the present invention, if the cooling water temperature is above a predetermined temperature by comparing the cooling water temperature with a predetermined temperature before the step of calculating the change rate, the fan is not operated by checking whether the fan is operating, and by checking the thermostat operation. If it does not work, by checking whether the heater is operating, if the heater does not operate, by checking whether the engine load is normal state can enter the next step when the engine load is normal state.

According to the present invention, the temperature of the cooling water is controlled by using a thermostat, and thus, the engine temperature is adjusted to easily control the ignition and combustion even under the high speed and high load of the engine. In particular, there is an effect that can improve the exhaust gas and engine performance in the high speed high load region of the HCCI engine.

In addition, the present invention has the advantage that it can contribute to cost reduction because hardware for the engine temperature control such as conventional exhaust circulation (EGR), variable valve timing is not required. Another advantage is that the engine room space can be freed up due to such hardware savings.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same reference numerals even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 and 2 are views showing the structure of a thermostat according to an embodiment of the present invention. The thermostat has a structure that is connected to the engine side pipeline 200, the heater side pipeline 300, and the bypass side pipeline 400, respectively, and has a central body 110, a housing 120, and an elastic member 130. , The bypass valve 132, the first electromagnet 140, and the second electromagnet 150 are included.

The central body 110 is located at the center of the housing 120.

The elastic member 130 is formed in a structure surrounding the outer circumferential surface of the central body 110 serves to support the bypass valve 132 in a shot. In one embodiment of the present invention, the elastic member 130 may be composed of a spring.

The bypass valve 132 is formed at the lower end of the central body 110 to move up and down, and is formed to open and close the bypass side conduit 400.

The first electromagnet 140 is fixedly positioned at the upper end of the housing 120 and generates magnetism when a current is applied. In one embodiment of the present invention, the first electromagnet 140 may be made of iron.

The second electromagnet 150 is attached to the upper end of the bypass valve 132 and generates magnetism when a current is applied. In one embodiment of the present invention, the second electromagnet 150 may be made of iron.

In the present invention, the opening and closing of the thermostat is controlled by using the magnetism of the first electromagnet 140 and the second electromagnet. Referring to the drawings the operation principle of the first electromagnet 140 and the second electromagnet in the present invention are as follows.

3 is a view showing an electromagnet portion of the thermostat according to an embodiment of the present invention.

In FIG. 3, the first electromagnet 140 and the second electromagnet 150 are respectively wrapped in a coil connected to an ECU (Electronic Control Unit) 160, and magnetically applied when current is applied to the coil under control of the ECU 160. Will be generated.

In one embodiment of the present invention, when the ECU 160 determines that the engine state is a high speed and high load region, the ECU 160 applies a current to the coil so that the magnetism in which the first electromagnet 140 and the second electromagnet 150 attract each other is generated. For example, in FIG. 3, since the S pole of the first electromagnet 140 and the N pole of the second electromagnet 150 face each other in the magnetic polarity of the first electromagnet 140 and the second electromagnet 150, the attraction force is increased. Works. Accordingly, the fixed second electromagnet 150 attracts the first electromagnet 140, and thus the bypass valve 132 moves upward. In accordance with the movement of the bypass valve 132, a pipe connected to the thermostat is opened.

In the present invention, the ECU 160 calculates the rate of change of the coolant temperature and determines that the engine state is a high speed high load region when the rate of change of the coolant temperature exceeds a predetermined first reference value. When the ECU 160 determines that the engine state is a high speed high load region, as shown in FIG. 3, the ECU 160 applies a current to the coil surrounding the electromagnet so that the second electromagnet 150 pulls the first electromagnet 140. This will open the thermostat to regulate the coolant temperature and consequently the engine temperature.

In the present invention, the determination of the high speed, high load region of the engine may be determined using the rate of change of the cooling water temperature. In other words, when the engine is driven at high speed and high load, the engine temperature is higher than when driven at low speed and low load. When the engine temperature is high, the cooling water temperature is changed, and the rate of change of the cooling water temperature is increased at high speed and high load. Therefore, when the rate of change of the cooling water temperature is more than the predetermined reference value, it can be determined that the engine is a high speed and high load. Detailed description of the method of controlling the thermostat using the cooling water temperature change rate will be described later.

In the present invention, after determining that the engine state is the high speed high load region, the ECU 160 stops supplying the current applied to the coil when the rate of change of the cooling water temperature is less than the second predetermined reference value.

4 is a flowchart illustrating a thermostat control method according to an embodiment of the present invention.

When the engine start is on (S401), the cooling water temperature is monitored (S403). The rate of change of cooling water temperature, which is the rate of change of cooling water temperature, is calculated (S405). In one embodiment of the present invention, the rate of change of the cooling water temperature may be calculated by checking the degree of change of the cooling water temperature during the monitoring time.

Next, it is checked whether the rate of change of the cooling water temperature exceeds the first predetermined reference value (S407). When the rate of change of the cooling water temperature exceeds the first reference value, the thermostat is controlled to open the conduit connected to the thermostat (S409). In the present invention, the thermostat may be controlled using the electromagnets 140 and 150.

Thus, when the thermostat is opened in the present invention, it is possible to cool the cooling water more efficiently than simply cooling the cooling water using a cooling fan. For example, in the case where the vehicle speed is increased to 100 degrees Celsius at 80 Kph, the cooling fan can be used to cool the cooling water to 90 degrees Celsius, but the temperature of the coolant is controlled to 80 degrees Celsius by controlling the thermostat as in the present invention. Cooling area can be expanded further by cooling. When the coolant temperature is relatively lowered as described above, the engine temperature is lowered and the engine temperature is kept constant at the temperature at which the engine is to be controlled, so that the ignition and combustion timing can be properly controlled.

Next, check whether the cooling water temperature reaches the target value (S411). For example, if the target value is 80 degrees Celsius, it is to check whether the cooling water temperature reaches 80 degrees Celsius.

When the cooling water temperature reaches the target value, it is determined whether the cooling water temperature change rate is less than the second predetermined reference value (S413).

If the cooling water temperature is less than the second predetermined reference value, the thermostat is controlled to close the conduit connected to the thermostat (S415). In the present invention, when the thermostat is controlled using the electromagnets 140 and 150, the thermostat may be controlled to close the conduit connected to the thermostat by stopping current application to the coil surrounding the electromagnets 140 and 150. .

In an embodiment of the present invention, the algorithm of the present invention may be applied only when certain conditions are satisfied before entering the step S403.

5 is a flowchart illustrating a thermostat control method according to an embodiment of the present invention.

In FIG. 5, the cooling water temperature is compared with the predetermined temperature to determine whether the cooling water temperature is greater than or equal to the predetermined temperature (S501). If the cooling water temperature is above a predetermined temperature, check whether the fan is operating (S503). This is because it is not necessary to forcibly control the thermostat when the cooling water temperature is lower than the predetermined temperature.

Next, if the fan does not operate, check whether the thermostat is operating (S505). When the fan is running, the cooling of the coolant by the fan takes place, which prevents cooling by using a thermostat.

If the thermostat does not work, check whether the heater is operating (S507). The operation of the thermostat means that the thermostat is automatically operated by the physical characteristics, so that it is not necessary to control the thermostat using the electromagnet as in the present invention.

Next, if the heater does not operate, it is checked whether the engine load is in a normal state (S509). If the engine state is normal, the cooling water temperature monitoring starts (S403).

While the invention has been described using some preferred embodiments, these embodiments are illustrative and not restrictive. Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the invention and the scope of the rights set forth in the appended claims.

1 and 2 are views showing the structure of a thermostat according to an embodiment of the present invention.

3 is a view showing an electromagnet portion of the thermostat according to an embodiment of the present invention.

4 and 5 are flowcharts illustrating a thermostat control method according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

110 centerpiece 120 housing

130 Elastic member 132 Bypass valve

140 First Electromagnet 150 Second Electromagnet

160 ECU 200 Engine Side Pipeline

300 Heater side pipeline 400 Bypass side pipeline

Claims (8)

delete delete In the thermostat connected to the engine side, the heater side and the bypass side, respectively, housing; A central body located in the center of the housing; A bypass valve formed at a lower end of the center body and configured to move up and down and open and close a bypass side conduit; An elastic member formed to have a structure surrounding the outer circumferential surface of the central body, and elastically supporting the bypass valve; A first electromagnet fixedly positioned at an upper end of the housing, wrapped in a coil connected to an ECU (Electronic Control Unit) and generating magnetism when current is applied to the coil under control of the ECU; A second electromagnet attached to an upper end of the bypass valve, wrapped in a coil connected to an ECU (Electronic Control Unit), and generating a magnetism when current is applied to the coil under control of the ECU; Including; The ECU, when it is determined that the engine state is a high speed high load region, the thermostat, characterized in that to apply a current to the coil so that the magnetism is attracted to the first electromagnet and the second electromagnet. The method of claim 3, The ECU calculates a rate of change of the coolant temperature, and if the rate of change of the coolant temperature exceeds a predetermined first reference value, the thermostat characterized in that the engine state is a high speed high load region. The method of claim 4, wherein And the ECU stops supplying current applied to the coil when the rate of change of the cooling water temperature is less than the second predetermined reference value after determining that the engine state is a high speed high load region. Connected to an engine side, a heater side, and a bypass side, respectively, a housing, a central body located in the center of the housing, a bypass valve formed at the lower end of the central body, and fixed to the upper end of the housing and wrapped in a coil. In the control method of the thermostat consisting of a first electromagnet generating a magnetism when the current is applied, and a second electromagnet attached to the upper end of the bypass valve and wrapped in a coil so as to generate a magnetism when the current is applied to the coil , A change rate calculating step of calculating cooling water temperature change rate by monitoring the cooling water temperature when the engine start is turned on; Check if the rate of change of the coolant temperature exceeds the predetermined first reference value, and if the first reference value is exceeded, determine that the engine is in the high speed and high load region, and generate magnetism to attract the first and second electromagnets to each other. A thermostat opening step of controlling the thermostat to open the conduit; Thermostat control method comprising a. The method of claim 6, After the thermostat opening step, Confirming whether the cooling water temperature reaches a target value; Checking whether the rate of change of cooling water is less than a second predetermined reference value when the cooling water temperature reaches a target value; Thermostat closing step of controlling the thermostat so that the conduit connected to the thermostat is closed if the coolant temperature is less than the second predetermined threshold Thermostat control method comprising more. The method of claim 6 or 7, wherein before the step of calculating the rate of change, If the cooling water temperature is higher than the predetermined temperature by comparing the cooling water temperature with the predetermined temperature, check whether the fan is operating. If the fan is not working. If the thermostat is not working, check whether the heater is working. The method of controlling the thermostat, characterized in that the heater enters the next step only when one or more of the conditions are met or the engine load is in a normal state by checking whether the engine load is in a normal state.

Images