KR102589931B1 - System and method for controlling evaporation gas in vehicles - Google Patents

Abstract

The present invention includes a sealing portion provided on a path through which evaporation gas collected in a canister from a fuel tank is discharged to the atmosphere, and mechanically opened and closed by pressure provided from the canister; a detection unit provided on a path through which air containing evaporative gas passes through the seal and is discharged to the atmosphere, and detects whether the air passes through; A temperature and pressure sensor that measures the temperature and pressure inside the fuel tank; And when air passing through the detector is detected in the ignition off state, the amount of evaporative gas adsorbed to the canister is calculated based on the temperature and pressure measured by the temperature and pressure sensor, and when the ignition is turned on, the amount of evaporative gas absorbed in the canister is calculated. A vehicle evaporative gas control system and method including a control unit that controls evaporative gas by reflecting the amount of adsorbed evaporative gas is introduced.

Description

System and method for controlling evaporation gas in vehicles {System and method for controlling evaporation gas in vehicles}

The present invention relates to a system and method for an evaporative gas control system for a vehicle that efficiently performs evaporative gas control when the vehicle is driven by calculating the amount of evaporative gas adsorbed to the canister when the vehicle is not driven.

The fuel in the fuel tank evaporates due to external heat, or evaporative gas is generated when refueling.

When evaporative gas (HC gas) is released into the atmosphere, it causes environmental pollution, and when it enters the room, it causes a fuel smell, causing discomfort to passengers.

To solve this problem, a method of collecting evaporative gas in a canister is adopted, and the evaporative gas collected in the canister flows into the engine surge tank through a purge valve and is burned.

At this time, in order to consume the evaporative gas collected in the canister while driving the vehicle, the evaporative gas is purged by controlling the purge duty according to the target purge flow rate calculated by the vehicle's controller.

Meanwhile, when a vehicle with existing sealed fuel tank specifications is left with the engine turned off in a high temperature environment, the fuel in the fuel tank continues to evaporate, and the pressure in the sealed system increases excessively due to the evaporation gas generated at this time.

Accordingly, when the relief valve provided in the canister toward the atmosphere cannot overcome the pressure and opens mechanically, the evaporation gas is adsorbed to the canister.

In this case, since the vehicle is in an undriven state, it is not possible to know when the valve was opened and how long the valve was open, making it impossible to calculate the concentration of evaporative gas adsorbed to the canister.

Therefore, since the concentration of evaporative gas adsorbed in the canister is not known, there is a problem in that evaporative gas control is inevitably limited, and as a result, it is impossible to satisfy emission regulations set by the certification agency.

The matters described as background technology above are only for the purpose of improving understanding of the background of the present invention, and should not be taken as acknowledgment that they correspond to prior art already known to those skilled in the art.

KR 10-2107300 B

The present invention was developed to solve the problems described above, and is a vehicle evaporative gas control system that efficiently performs evaporative gas control when the vehicle is driven by calculating the amount of evaporative gas adsorbed to the canister when the vehicle is not driven. The goal is to provide systems and methods.

The configuration of the vehicle evaporative gas control system of the present invention to achieve the above object is provided on a path through which the evaporative gas collected in the canister from the fuel tank is discharged to the atmosphere, and is mechanically controlled by the pressure provided from the canister. A sealing part that is opened and closed by; a detection unit provided on a path through which air containing evaporative gas passes through the seal and is discharged to the atmosphere, and detects whether the air passes through; A temperature and pressure sensor that measures the temperature and pressure inside the fuel tank; And when air passing through the detector is detected in the ignition off state, the amount of evaporative gas adsorbed to the canister is calculated based on the temperature and pressure measured by the temperature and pressure sensor, and when the ignition is turned on, the amount of evaporative gas absorbed in the canister is calculated. It may be characterized by including a control unit that controls the boil-off gas by reflecting the adsorption amount of the adsorbed boil-off gas.

The detection unit detects the flow rate of air; The control unit may determine that air has passed when the air flow rate detected by the detection unit exceeds the effective flow rate.

The control unit includes a monitoring module that calculates changing pressure and temperature values in the fuel tank using the temperature and pressure measured by the temperature and pressure sensor when detecting air passing through the detection unit; It may include an ECU that calculates the adsorption amount of boil-off gas using the pressure value and temperature value calculated by the monitoring module and boil-off gas mapping data mapped to the relationship between pressure and temperature.

The pressure value is the integrated value of the decreasing pressure in the fuel tank; The temperature value may be an average of the temperature within the fuel tank.

Pressure and temperature values can be calculated from the point where the pressure in the fuel tank decreases to the point where the pressure in the fuel tank stabilizes.

When the air flow rate passing through the detection unit exceeds the effective flow rate, the detection unit, monitoring module, and temperature pressure sensor are woken up and the monitoring module can begin calculating pressure and temperature values.

In the process where the monitoring module calculates the pressure and temperature values, if the air flow rate passing through the detection unit is less than the effective flow rate, the wake-up may be terminated after saving the pressure and temperature values calculated to date.

The configuration of the evaporative gas control method for a vehicle according to the present invention includes the steps of the control unit detecting air passing through the detection unit when the vehicle is started in an off state; When the control unit detects air passing through the detection unit, calculating the amount of evaporated gas adsorbed to the canister based on the temperature and pressure measured by the temperature and pressure sensor; The control unit may include a step of controlling evaporative gas by reflecting the amount of evaporative gas adsorbed to the canister when the vehicle is started.

Through the above-mentioned problem solving means, the present invention calculates the adsorption amount of evaporative gas adsorbed to the canister when the vehicle is not driven, and later uses the calculated evaporative gas adsorption amount in the vehicle non-driving state for evaporative gas control when the vehicle is driven. By reflecting this, there is an effect of performing evaporative gas control more accurately and efficiently.

1 is a diagram showing the configuration of an evaporative gas control system according to the present invention.
FIG. 2 is a diagram illustrating a method of calculating an integrated pressure value and an average temperature along with changes in pressure and temperature within a fuel tank according to the present invention.
Figure 3 is a flow chart illustrating the evaporation gas control process according to the present invention.

Specific structural and functional descriptions of the embodiments of the present invention disclosed in the present specification or application are merely illustrative for the purpose of explaining the embodiments according to the present invention, and the embodiments according to the present invention are implemented in various forms. It may be possible and should not be construed as being limited to the embodiments described in this specification or application.

Since the embodiments according to the present invention can make various changes and have various forms, specific embodiments will be illustrated in the drawings and described in detail in the present specification or application. However, this is not intended to limit the embodiments according to the concept of the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component, for example, without departing from the scope of rights according to the concept of the present invention, a first component may be named a second component, and similarly The second component may also be referred to as the first component.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "immediately between" or "neighboring" and "directly adjacent to" should be interpreted similarly.

The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the existence of a described feature, number, step, operation, component, part, or combination thereof, but are not intended to indicate the presence of one or more other features or numbers. It should be understood that this does not preclude the existence or addition of steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in this specification, should not be interpreted as having an ideal or excessively formal meaning. .

A preferred embodiment of the present invention will be described in detail with the accompanying drawings as follows.

Figure 1 is a diagram showing the configuration of an evaporative gas control system according to the present invention.

Referring to the drawing, the vehicle evaporative gas control system of the present invention is provided on a path through which evaporative gas collected in the canister 100 from the fuel tank 10 is discharged to the atmosphere, and the pressure provided from the canister 100 is A sealing portion 200 that is mechanically opened and closed by; A detection unit 300 provided on a path through which air containing evaporation gas passes through the sealing unit 200 and is discharged to the atmosphere, and detects whether the air passes through; A temperature and pressure sensor 400 that measures the temperature and pressure inside the fuel tank 10; And when air passing through the detection unit 300 is detected in the ignition off state, the amount of evaporation gas adsorbed to the canister 100 is calculated based on the temperature and pressure measured by the temperature and pressure sensor 400, and the ignition is started. When turned on, it is configured to include a control unit 500 that controls the evaporation gas by reflecting the amount of evaporation gas adsorbed to the canister 100 in the ignition-off state.

Specifically, the evaporative gas control system according to the present invention includes a fuel tank 10, a temperature pressure sensor 400, a canister 100, a seal 200, an active purge pump 600, and a PCSV 700. This forms a closed system.

The fuel tank 10 may be a sealed fuel tank 10 designed to store fuel and withstand pressure above a certain level, and the temperature and pressure sensor 400 is connected to the inside of the fuel tank 10 to determine the fuel tank 10. ) It serves to measure internal temperature and pressure.

The canister 100 is connected to the fuel tank 10 and adsorbs evaporation gas generated from the fuel tank 10.

The sealing portion 200 is disposed to be openable and closed at the atmospheric entrance of the canister 100 and includes a control valve 220 and a relief valve 210.

The control valve 220 is operated so that the pressure of the sealed system (ex: pressure provided from the canister 100 or fuel tank 10 pressure) is maintained at a certain value set by the ECU (520) when the ECU (520) is turned on. When it arrives, an electrical signal is applied from the ECU 520 to open it, thereby relieving the pressure of the closed system.

The relief valve 210 is mechanically opened when the pressure provided from the canister 100 becomes excessively high or low while the ECU 520 is turned off, and the relief valve cannot overcome the pressure, thereby reducing the pressure of the closed system. It plays a role in dissolving.

The detection unit 300 may be a flow meter installed at the atmospheric entrance of the sealing unit 200 to measure the flow rate, and detects whether the air passes through the canister 100 by detecting the flow rate of the evaporated gas and air discharged from the canister 100. can do.

The purge pump 600 serves to pump and lift the evaporative gas adsorbed on the canister 100, and the PCSV (700) (Purge Control Solenoid Valve) pumps the evaporative gas sucked up through the purge pump 600 into the engine intake. It is sent to the organ to purge it.

In particular, when the control unit 500 detects air generated in the atmospheric direction through the detection unit 300 in the ignition off state, the canister ( 100) The adsorption amount of boil-off gas adsorbed is calculated.

And, when the engine is switched to the on-state, evaporation gas control, including purge control, is performed based on the calculated adsorption amount of evaporation gas.

According to the above configuration, the adsorption amount of evaporative gas adsorbed to the canister 100 when the vehicle is not driven is calculated, and when the vehicle is later driven, the calculated evaporative gas adsorption amount in the vehicle not driven state is reflected in the evaporative gas control. , evaporative gas control can be performed more accurately and efficiently.

For reference, the control unit 500 according to an exemplary embodiment of the present invention has a non-volatile memory (not shown) configured to store data regarding an algorithm configured to control the operation of various components of a vehicle or a software instruction that reproduces the algorithm. (not shown) and may be implemented through a processor (not shown) configured to perform the operations described below using data stored in the corresponding memory. Here, the memory and processor may be implemented as individual chips. Alternatively, the memory and processor may be implemented as a single chip integrated with each other. A processor may take the form of one or more processors.

Meanwhile, referring to Figure 1, in the present invention, the detection unit 300 detects the flow rate of air; The control unit 500 may determine that air has passed when the air flow rate detected by the detection unit 300 exceeds the effective flow rate.

For example, the detection unit 300 may be a flow meter, and the flow meter 300 may have a structure with a built-in switch. Accordingly, when a flow rate greater than the effective flow rate occurs in the pipe of the flow meter 300, the switch is turned on and it can be determined that air has passed.

In addition, the control unit 500 of the present invention may be configured to include a monitoring module 510 and an ECU 520.

When detecting air passing through the detection unit 300, the monitoring module 510 calculates the changing pressure and temperature values in the fuel tank 10 using the temperature and pressure measured by the temperature and pressure sensor 400.

The ECU 520 receives the pressure and temperature values calculated from the monitoring module 510 and calculates the adsorption amount of the boil-off gas using the boil-off gas mapping data mapped to the relationship between pressure and temperature.

At this time, the pressure value calculated by the monitoring module 510 is the integrated value of the pressure decreasing within the fuel tank 10; The temperature value is the average value of the temperature within the fuel tank 10.

And, the pressure value and temperature value are values calculated from the time when the pressure within the fuel tank 10 decreases to the time when the pressure within the fuel tank 10 is stabilized.

Figure 2 is a diagram for explaining a method of calculating the integrated pressure value and average temperature along with changes in pressure and temperature within the fuel tank 10 according to the present invention.

Referring to the drawing, a method for calculating the pressure integration value and average temperature will be described. When the pressure provided to the sealing part 200 from the canister 100 reaches the limit pressure (p2) of the relief valve 210, In this case, the relief valve 210 is opened.

When the relief valve 210 is opened, a flow of air occurs in the atmospheric direction of the seal 200, and the flow meter 300 operates, thereby monitoring the temperature and pressure within the fuel tank 10.

At the same time, when the relief valve 210 is opened, the evaporation gas in the fuel tank 10 moves to the canister 100, and the pressure inside the fuel tank 10 begins to decrease. The difference between the pressure (p1) at the time when it starts to decrease (t1) and the pressure (p2) until the point at which it stabilizes (t2) is integrated into unit time to calculate the area of area A, thereby calculating the integrated pressure value. do.

The formula for calculating the pressure integration value can be defined as follows.

Additionally, the temperature within the fuel tank 10 between time t1 and time t2 is stored as an average value.

In addition, the pressure integration value and average temperature calculated as above are stored in the monitoring module 510, and when the ECU 520 is turned on later when the vehicle is started, the value stored in the monitoring module 510 is transmitted to the ECU 520. The adsorption amount of evaporative gas adsorbed on the canister 100 is calculated through the evaporative gas mapping data transmitted and mapped to the ECU 520.

Meanwhile, in the present invention, when air passing through the detection unit 300 is detected, the detection unit 300, the monitoring module 510, and the temperature pressure sensor 400 wake up to calculate the pressure and temperature values in the monitoring module 510. You can start doing it.

For example, when the turbine of the flow meter 300 operates due to the flow rate of air, the switch of the flow meter 300 is turned on and power is turned on to the flow meter 300, the monitoring module 510, and the temperature and pressure sensor 400. It is approved and wakes them up.

That is, if the power to the monitoring module 510, the detection unit 300, and the temperature pressure sensor 400 is cut off when the vehicle is not driven, and the air flow rate exceeding the effective flow rate is detected in the detection unit 300, the monitoring module By waking up the detection unit 300 and the temperature pressure sensor 400 (510), unnecessary power consumption is blocked and battery discharge is prevented.

In addition, in the present invention, when the air flow rate passing through the detection unit 300 is less than the effective flow rate in the process of the monitoring module 510 calculating the pressure value and temperature value, the pressure value and temperature value calculated to date are stored and then wake. The business may end.

That is, if the air flow rate passing through the flow meter 300 does not occur, or occurs in the opposite direction to the atmospheric side, the calculation of the pressure value and temperature value by the monitoring module 510 is stopped, and the pressure value calculated before the stop is accumulated. After saving the value and average temperature, wake-up of the monitoring module 510, detection unit 300, and temperature pressure sensor 400 is stopped.

Meanwhile, the configuration of the method for controlling evaporative gas of a vehicle according to the present invention is a method of controlling evaporative gas of a vehicle, wherein the control unit 500 detects air passing through the detection unit 300 when the vehicle is started in an off state. ; When the control unit 500 detects air passing through the detection unit 300, it calculates the amount of evaporation gas adsorbed to the canister 100 based on the temperature and pressure measured by the temperature and pressure sensor 400. step; The control unit 500 is configured to include a step of controlling the evaporation gas by reflecting the amount of evaporation gas adsorbed to the canister 100 when the vehicle is started.

Figure 3 is a flow chart illustrating the evaporation gas control process according to the present invention.

Accordingly, below, the flow of the boil-off gas control process according to the present invention will be described by way of example with reference to FIG. 3.

When the vehicle is left in a high-temperature environment with the engine turned off for a long time, the pressure of the sealed system connected to the sealed fuel tank 10 gradually increases.

Accordingly, when the relief valve 210 constituting the sealing part 200 is opened by the pressure provided to the sealing part 200 from the canister 100 so as not to overcome the pressure, air containing the evaporation gas flows through the relief valve 210. ) and flows toward the flow meter 300.

Then, the turbine of the flow meter 300 rotates due to the flow rate passing through the pipe of the flow meter 300, and the switch of the flow meter 300 is turned on due to the operation of the turbine of the flow meter 300 (S10), and the monitoring module ( 510), the flow meter 300 and the temperature and pressure sensor 400 are woken up (S20).

Next, the temperature and pressure of the fuel tank 10 are measured by the temperature and pressure sensor 400 and transmitted to the monitoring module 510 (S30).

In addition, the monitoring module 510 uses the temperature and pressure measured by the temperature and pressure sensor 400 to calculate the pressure integration value by accumulating the decreasing pressure within the fuel tank 10. Calculate the average value of the changing temperature (S40).

In this way, in the process of calculating the integrated pressure value and average temperature, it is determined whether the flow rate detected by the flow meter 300 is more than the effective flow rate (S50).

As a result of the judgment in step S50, if the detected flow rate of the flow meter 300 is more than the effective flow rate, the pressure integration value and average temperature calculation are continued, and if it is less than the effective flow rate, the pressure integration value and average temperature value calculated to date are stored. , Wakeup ends (S60).

Meanwhile, later, when the vehicle starts, it is determined whether the ECU 520 is turned on (S70), and when the ECU 520 is turned on, the pressure integration value and average temperature calculated from the monitoring module 510 are transmitted to the ECU 520. do.

Then, the ECU (520) calculates the adsorption amount of the boil-off gas adsorbed on the canister 100 using pre-mapped boil-off gas mapping data using the pressure integration value and the average temperature, and uses the calculated boil-off gas adsorption amount as Based on this, evaporation gas is controlled (S80).

Afterwards, it is determined whether the ECU 520 is turned off (S90), and when the ECU 520 is turned off, the process moves to step S10, so that the logic of the present invention can be continuously implemented when the vehicle is not driven.

As described above, the present invention calculates the amount of evaporative gas adsorbed to the canister 100 when the vehicle is not driven, and later uses the calculated amount of evaporative gas adsorption in the non-driving state to control evaporative gas when the vehicle is driven. By reflecting this, evaporative gas control is performed more accurately and efficiently.

Meanwhile, although the present invention has been described in detail only with respect to the above-mentioned specific examples, it is clear to those skilled in the art that various changes and modifications are possible within the technical scope of the present invention, and it is natural that such changes and modifications fall within the scope of the appended patent claims. .

10: Fuel tank
100: canister
200: sealing part
210: relief valve
220: control valve
300: Detection unit (flow meter)
400: Temperature pressure sensor
500: Control unit
510: Monitoring module
520:ECU
600: Purge pump
700:PCSV

Claims (8)

A sealing portion provided on a path through which the evaporative gas collected in the canister from the fuel tank is discharged to the atmosphere, and mechanically opened and closed by pressure provided from the canister;
a detection unit provided on a path through which air containing evaporative gas passes through the seal and is discharged to the atmosphere, and detects whether the air passes through;
A temperature and pressure sensor that measures the temperature and pressure inside the fuel tank; and
When detecting air passing through the detector when the engine is off, the amount of evaporative gas adsorbed to the canister is calculated based on the temperature and pressure measured by the temperature and pressure sensor. When the engine is turned on, it is absorbed into the canister when the engine is off. It includes a control unit that controls the boil-off gas by reflecting the adsorption amount of the boil-off gas,
The control unit,
A monitoring module that calculates changing pressure and temperature values in the fuel tank using the temperature and pressure measured by the temperature and pressure sensor when detecting air passing through the detection unit;
It includes an ECU that calculates the adsorption amount of boil-off gas using the pressure value and temperature value calculated in the monitoring module and the boil-off gas mapping data mapped to the relationship between pressure and temperature,
A vehicle evaporative gas control system characterized in that pressure and temperature values are calculated from the point when the pressure in the fuel tank decreases to the point when the pressure in the fuel tank stabilizes. In claim 1,
The detection unit detects the flow rate of air;
An evaporative gas control system for a vehicle, wherein the control unit determines that air has passed when the air flow rate detected by the detection unit exceeds the effective flow rate. delete In claim 1,
The pressure value is the integrated value of the decreasing pressure in the fuel tank;
A vehicle evaporative gas control system, wherein the temperature value is an average value of the temperature within the fuel tank. delete In claim 1,
An evaporative gas control system for a vehicle, wherein when the air flow rate passing through the detection unit exceeds the effective flow rate, the detection unit, monitoring module, and temperature pressure sensor wake up and the monitoring module begins to calculate pressure and temperature values. In claim 1,
When the air flow rate passing through the detection unit is less than the effective flow rate during the process of the monitoring module calculating the pressure and temperature values, the evaporation of the vehicle is characterized in that the wake-up is terminated after saving the pressure and temperature values calculated to date. Gas control system. A method of controlling evaporative gas of a vehicle in the vehicle evaporative gas control system according to claim 1, comprising:
A control unit detecting air passing through the detection unit when the vehicle is in an ignition-off state;
When the control unit detects air passing through the detection unit, calculating the amount of evaporated gas adsorbed to the canister based on the temperature and pressure measured by the temperature and pressure sensor;
A step of controlling, by the control unit, evaporative gas by reflecting the amount of evaporative gas adsorbed to the canister when the vehicle is started,
When detecting air passing through the detection unit, the control unit calculates the changing pressure and temperature values in the fuel tank using the temperature and pressure measured by the temperature pressure sensor.
Calculate the adsorption amount of boil-off gas using the pressure value and temperature value calculated by the control unit and the boil-off gas mapping data mapped to the relationship between pressure and temperature,
A method for controlling evaporative gases in a vehicle, characterized in that the pressure value and temperature value are calculated from the time the pressure in the fuel tank decreases to the time the pressure in the fuel tank stabilizes.

Images