KR101791756B1 - Fuel Supply System of Vehicle and Method of Driving Thereof - Google Patents

Abstract

The present invention relates to a fuel supply system for a vehicle and a driving method thereof, which can accurately estimate the temperature of the fuel existing between a low-pressure pump and a high-pressure pump to improve stability of the fuel supply and improve fuel economy. A fuel supply system for a vehicle according to an embodiment of the present invention includes a fuel tank pressure sensor disposed in a fuel tank for detecting a pressure in the fuel tank and outputting a pressure value; And an ECU (Electronic Control Unit) for calculating the fuel temperature in the low pressure section based on the pressure value. The ECU adjusts the fuel delivery pressure of the low-pressure pump based on the fuel temperature in the low-pressure section. This fuel supply system of the vehicle can accurately estimate the fuel temperature in the low pressure section without the temperature sensor.

Description

Technical Field [0001] The present invention relates to a fuel supply system for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for a vehicle and a driving method thereof, and more particularly to a fuel supply system for a vehicle, which accurately estimates a temperature of a fuel present between a low- And a method of driving the fuel supply system.

The boiling point of gasoline is about 30 ° C to 200 ° C, and it evaporates easily at room temperature. As described above, the property of vaporization from a liquid to a gas is called volatility, and a liquid having a high volatility is easily vaporized.

The temperature of the fuel is one of the important factors for correcting the fuel injection. Depending on the temperature of the fuel, the density changes and the overall volume changes. The amount of fuel flowing into the cylinder of the first engine and the amount of fuel flowing into the cylinder of the second engine are different even if the fuel is injected into the two engines having different temperatures for the same time.

Therefore, accurate detection or estimation of the temperature of the fuel can accurately control the amount of fuel injected into the cylinder. The amount of fuel injected into the cylinders must be correct so that the engine can be normally driven and a desired fuel economy can be obtained.

As a first method of detecting the fuel temperature, a temperature sensor may be disposed in the low-pressure pipe to directly detect the temperature of the fuel. Here, the first method is advantageous in that the temperature is directly measured by using a temperature sensor, thereby achieving high accuracy. However, there is a disadvantage in that the cost is increased due to the necessity of additionally providing a temperature sensor, and there is a problem that leakage may occur in the process of sending fuel through pressure.

As a second method of detecting the fuel temperature, it is possible to estimate the fuel temperature of the low-pressure pipe by analyzing other factors besides the fuel. Here, the second method is advantageous in that it is not necessary to provide a temperature sensor and cost reduction and leakage can be prevented. However, there is a problem in that the accuracy of the fuel is low because the fuel temperature is indirectly estimated through other factors rather than directly measuring the temperature of the fuel.

When the fuel is at a high temperature, air bubbles may be generated in the duct for sending out the fuel. If air bubbles are generated in the pipeline, the fuel injection from the DGI (Gasoline Direct Injection) system will not be performed properly, and the cylinder will not be able to accurately detect the cylinder. Such bubbles in the pipeline can be removed by sending the fuel to high pressure. However, there is another problem that the fuel consumption is lowered when the fuel is always supplied at a high pressure in the entire section of the oil pipeline. Therefore, there is a demand for a fuel supply system for a vehicle and a driving method thereof, which can accurately estimate a fuel temperature in a low-pressure section without increasing costs and improve fuel economy.

Korean Patent Publication No. 10-2014-0097588 (Apparatus and method for controlling fuel supply of an internal combustion engine operated using liquefied gas)

The inventors of the present application recognize the above-mentioned problems and propose the following technical problems.

SUMMARY OF THE INVENTION The present invention provides a fuel supply system for a vehicle and a method of driving the same that can accurately estimate a fuel temperature in a low pressure section.

It is still another object of the present invention to provide a fuel supply system for a vehicle that supports the stability of fuel supply and a driving method thereof.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

According to an aspect of the present invention, there is provided a fuel supply system for a vehicle, comprising: a fuel tank pressure sensor disposed in a fuel tank for detecting a pressure in the fuel tank and outputting a pressure value; A low pressure pump for sending the fuel inputted from the low pressure section to a predetermined pressure, and an ECU (Electronic Control Unit) for calculating the fuel temperature in the low pressure section based on the pressure value. The ECU adjusts the fuel delivery pressure of the low-pressure pump based on the fuel temperature in the low-pressure section.

The ECU of the fuel supply system of the vehicle according to the embodiment of the present invention controls the delivery pressure of the low pressure pump so that the fuel is delivered to the first pressure when the fuel temperature in the low pressure interval is below the reference temperature. When the fuel temperature in the low pressure section exceeds the reference temperature, the delivery pressure of the low pressure pump is controlled such that the fuel is delivered to the second pressure higher than the first pressure.

The ECU of the fuel supply system of the vehicle according to the embodiment of the present invention controls the delivery pressure of the low pressure pump so as to be proportional to the fuel temperature in the low pressure interval.

The ECU of the fuel supply system of the vehicle according to the embodiment of the present invention determines that a failure has occurred in the fuel tank pressure sensor when the pressure value exceeds a preset pressure range. If the pressure value does not exceed the predetermined pressure range, it is determined that the fuel tank pressure sensor operates normally.

The ECU of the fuel supply system of the vehicle according to the embodiment of the present invention controls the delivery pressure of the low pressure pump such that fuel is delivered to the second pressure when it is determined that a failure has occurred in the fuel tank pressure sensor.

A method of driving a fuel supply system for a vehicle according to an embodiment of the present invention includes: detecting a pressure in the fuel tank by a fuel tank pressure sensor disposed in the fuel tank; Calculating a fuel temperature in a low-pressure section based on a pressure in the fuel tank; And adjusting a fuel delivery pressure of the low-pressure pump based on the fuel temperature in the low-pressure section.

The method of driving a fuel supply system of a vehicle according to an embodiment of the present invention controls the delivery pressure of the low-pressure pump so that fuel is delivered to the first pressure when the fuel temperature in the low-pressure section is below a reference temperature. When the fuel temperature in the low pressure section exceeds the reference temperature, the delivery pressure of the low pressure pump is controlled such that the fuel is delivered to the second pressure higher than the first pressure.

The driving method of the fuel supply system of the vehicle according to the embodiment of the present invention controls the delivery pressure of the low pressure pump so as to be proportional to the fuel temperature in the low pressure interval.

The method of driving a fuel supply system for a vehicle according to an embodiment of the present invention determines that a failure occurs in the fuel tank pressure sensor when the pressure in the fuel tank exceeds a preset pressure range. If the pressure in the fuel tank does not exceed the predetermined pressure range, it is determined that the fuel tank pressure sensor operates normally.

The method of driving a fuel supply system for a vehicle according to an embodiment of the present invention controls the delivery pressure of the low-pressure pump so that fuel is delivered to the fuel tank pressure sensor when a failure occurs in the fuel tank pressure sensor.

The fuel supply system and the driving method of the vehicle according to the embodiment of the present invention can accurately estimate the fuel temperature in the low pressure section without the temperature sensor.

The fuel supply system of the vehicle and the driving method thereof according to the embodiment of the present invention can support the stability of the fuel supply.

The fuel supply system and the driving method of the vehicle according to the embodiment of the present invention enable the vehicle to travel to the garage by sending fuel at a high pressure even if a failure occurs in the fuel tank pressure sensor located in the fuel tank.

In addition, other features and advantages of the present invention may be newly understood through embodiments of the present invention.

1 is a view showing a fuel supply system of a vehicle according to an embodiment of the present invention.
Fig. 2 is a graph showing the characteristics of gasoline being volatilized according to the relationship between temperature and pressure.
3 is a view showing a driving method of a fuel supply system of a vehicle according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

If any part is referred to as being "on" another part, it may be directly on the other part or may be accompanied by another part therebetween. In contrast, when a section is referred to as being "directly above" another section, no other section is involved.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

Terms indicating relative space such as "below "," above ", and the like may be used to more easily describe the relationship to other portions of a portion shown in the figures. These terms are intended to include other meanings or acts of the apparatus in use, as well as intended meanings in the drawings. For example, when inverting a device in the figures, certain parts that are described as being "below" other parts are described as being "above " other parts. Thus, an exemplary term "below" includes both up and down directions. The device can be rotated by 90 degrees or rotated at different angles, and terms indicating relative space are interpreted accordingly.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

1 is a view showing a fuel supply system of a vehicle according to an embodiment of the present invention.

1, a fuel supply system 100 for a vehicle according to an embodiment of the present invention includes a fuel tank pressure sensor 190, a low pressure pump 130 and an ECU 180 Unit). The fuel supply system 100 of the vehicle does not have a separate temperature sensor but estimates the fuel temperature of the low pressure section (low pressure pipe) in the fuel supply path.

The fuel sent out from the fuel tank 110 is supplied to the low pressure pump 130 through the tank line 120 and the low pressure pump 130 delivers the inputted fuel at a low pressure (for example, 3 atm or less). The low-pressure fuel sent from the low-pressure pump 130 is supplied to the high-pressure pump 150 via the low-pressure line 140.

The high-pressure pump 150 delivers the input fuel at a high pressure (for example, 6 atm or higher). The high-pressure fuel delivered from the high-pressure pump 150 is supplied to the injection 170 via the high-pressure line 160. The injection 170 injects the input high-pressure fuel into the cylinder.

Fig. 2 is a graph showing the characteristics of gasoline being volatilized according to the relationship between temperature and pressure.

Referring to Fig. 2, the amount of gas evaporated by fuel vapor differs depending on the temperature of the fuel of the vehicle. Therefore, the temperature of the fuel discharged from the fuel tank 110 can be calculated based on the pressure measured by the fuel tank pressure sensor 190. As shown in FIG. 2, the fuel has different densities depending on the temperature, and the pressure value measured at the fuel tank pressure sensor 190 forms a temperature characteristic curve in the form of a curve.

The fuel tank pressure sensor 190 senses the leakage and purge leakage of the fuel tank 110 and detects the pressure inside the fuel tank 110. Then, pressure data is generated in accordance with the detection result, and the generated pressure data is supplied to the ECU 180. [

The ECU 180 calculates the temperature of the fuel delivered from the fuel tank 110 based on the pressure data input from the fuel tank pressure sensor 190. [ When the fuel sent from the fuel tank 110 is output to the low-pressure line 140 via the low-pressure pump 130 because the ECU 180 recognizes the pressure at which the low-pressure pump 130 outputs the fuel, Can be calculated. That is, the fuel temperature at the low-pressure section located between the low-pressure pump 130 and the high-pressure pump 150 can be calculated based on the pressure of the fuel tank 110.

The ECU 180 controls the driving of the low-pressure pump 130 by reflecting the result of estimating the temperature of the fuel located in the low-pressure line 140. For example, when the temperature of the fuel located in the low-pressure pipe 140 exceeds a predetermined first reference temperature, it is determined that the fuel is at a high temperature. As described above, when the DGI (Gasoline Direct Injection) system is applied to the engine, bubbles may be generated in the duct when the fuel is at a certain temperature or higher. Therefore, when the fuel located in the low-pressure pipe is at a high temperature, the ECU 180 raises the delivery pressure of the low-pressure pump 130 to a high pressure (for example, 3 atmospheric pressure) to deliver the fuel.

On the other hand, the ECU 180 determines that the fuel is at a low temperature when the temperature of the fuel located in the low-pressure pipe 140 is lower than a predetermined first reference temperature. The ECU 180 controls the driving of the low pressure pump 130 to send the delivery pressure of the low pressure pump 130 to the low pressure (for example, 3 atmospheres or less).

The ECU 180 detects the pressure of the fuel tank 110 by using the fuel tank pressure sensor 190 and the ECU 180 detects the pressure in the low pressure section (Low-pressure pipe). And controls the delivery pressure of the low-pressure pump 130 based on the estimated fuel temperature of the low-pressure section (low-pressure conduit). The ECU 180 adjusts the delivery pressure of the low-pressure pump 130 to a high pressure to prevent bubbles from being generated in the pipeline if the fuel temperature of the low-pressure section (low-pressure conduit) is high. Then, when the fuel temperature of the low-pressure section (low-pressure conduit) returns to the low temperature, the ECU 180 lowers the delivery pressure of the low-pressure pump 130 to the low pressure again.

As another example of the present invention, when the pressure of the fuel tank 110 is increased, the delivery pressure of the low-pressure pump 130 can be increased in proportion thereto. In contrast, when the pressure of the fuel tank 110 is lowered, the delivery pressure of the low-pressure pump 130 can be reduced in proportion thereto.

The ECU 180 determines that a failure has occurred in the fuel tank pressure sensor 190 when the pressure value of the fuel tank 110 input from the fuel tank pressure sensor 190 exceeds the effective range do. Thereafter, the ECU 180 stops driving estimating the fuel temperature of the low-pressure section (low-pressure conduit), raises the delivery pressure of the low-pressure pump 130, and sends out the fuel at a high pressure.

3 is a view showing a driving method of a fuel supply system of a vehicle according to an embodiment of the present invention.

Referring to FIGS. 1 and 3, the pressure of the fuel tank 110 is detected by a fuel tank pressure sensor 190 disposed in the fuel tank 110 (S10).

Thereafter, the ECU 180 receives the pressure value detected by the fuel tank pressure sensor 190 (S20). Then, the detected pressure value of the fuel tank 110 is stored in the memory.

Thereafter, the ECU 180 confirms the intake air temperature in addition to the pressure of the received fuel tank 110 (S30), and in addition, the ECU 180 confirms the temperature of the engine (S40). Here, further checking of the intake air temperature and the engine temperature in addition to the pressure of the fuel tank 110 is made by adding other factors of the vehicle to increase the accuracy in estimating the temperature of the fuel in the low pressure section (low pressure conduit).

On the other hand, in order to confirm whether the fuel tank pressure sensor 190 normally operates and the pressure of the fuel tank 110 received in S20 is measured, the ECU 180 controls the fuel tank pressure sensor 190, It is determined whether the pressure value of the pressure sensor 110 exceeds the effective range. That is, it is confirmed whether the fuel tank pressure sensor 190 operates normally (S50).

As a result of the determination in S50, if it is determined that the input value of the fuel tank 110 exceeds the effective range and the fuel tank pressure sensor 190 has failed, the operation of estimating the temperature of the fuel in the low pressure section (low pressure conduit) (S60).

Thereafter, the delivery pressure of the low-pressure pump 130 is raised so that the fuel delivered from the low-pressure pump 130 is always output at a high pressure (more than 3 atmospheres) (S70).

On the other hand, if it is determined in S50 that the pressure value of the input fuel tank 110 is within the effective range, it is determined that the fuel tank pressure sensor 190 has operated normally. Thereafter, the temperature of the fuel in the low-pressure section (low-pressure conduit) is estimated based on the pressure of the fuel tank 110 measured using the curve characteristic of the pressure and temperature shown in FIG. 2 (S80).

Thereafter, the intake temperature of S30, the engine temperature of S40, the fuel temperature of the low-pressure section (low-pressure pipe) estimated at S80, and other characteristics S90 of the vehicle are collected (S100).

Then, the temperature of the fuel of the low-pressure section (low-pressure pipe) is finally calculated (S110) by reflecting the intake air temperature, the engine temperature, the fuel temperature of the estimated low-pressure section, and other characteristics of the vehicle.

Thereafter, the ECU 180 determines that the fuel is at a low temperature when the temperature of the fuel located in the low-pressure section (low-pressure conduit) is equal to or lower than a predetermined first reference temperature. The ECU 180 controls the driving of the low pressure pump 130 to send the fuel to the low pressure pump 130 at a low pressure (for example, 3 atm or less) (S120).

On the other hand, when the temperature of the fuel located in the low-pressure section (low-pressure conduit) exceeds the predetermined first reference temperature, it is determined that the fuel is at a high temperature. As described above, when the DGI (Gasoline Direct Injection) system is applied to the engine, bubbles may be generated in the duct when the fuel is at a certain temperature or higher. Accordingly, when the fuel located in the low-pressure pipe is at a high temperature, the ECU 180 raises the delivery pressure of the low-pressure pump 130 to a high pressure (for example, more than 3 atmospheres) to deliver the fuel (S130).

The fuel supply system and the driving method of the vehicle according to the embodiment of the present invention can accurately estimate the fuel temperature in the low pressure section without the temperature sensor.

Further, the fuel supply system of the vehicle and the driving method thereof according to the embodiment of the present invention can support the stability of the fuel supply.

Also, the fuel supply system and the driving method of the vehicle according to the embodiment of the present invention can deliver the fuel at a high pressure even if a failure occurs in the fuel tank pressure sensor 190 located in the fuel tank 110, .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: vehicle fuel supply system
110: Fuel tank
120: tank channel
130: Low pressure pump
140: Low pressure pipe
150: High pressure pump
160: High pressure pipe
170: injector
180: ECU (Electronic Control Unit)
190: Fuel tank pressure sensor

Claims (10)

A fuel tank pressure sensor disposed in the fuel tank for detecting a pressure in the fuel tank and outputting a pressure value;
A low pressure pump for sending the fuel inputted from the fuel tank to a predetermined pressure; And
An ECU (Electronic Control Unit) for calculating the fuel temperature in the low pressure section based on the pressure value;
Lt; / RTI >
Wherein the ECU controls the delivery pressure of the low-pressure pump so that the fuel is delivered to the first pressure when the fuel temperature in the low-pressure section is equal to or lower than the reference temperature, and when the fuel temperature in the low- Controls the delivery pressure of the low-pressure pump so that the fuel is delivered to the second pressure higher than the first pressure,
The ECU determines that a failure has occurred in the fuel tank pressure sensor when the pressure of the low pressure pump is controlled so as to be proportional to the fuel temperature in the low pressure section and the pressure value exceeds a preset pressure range, Determines that the fuel tank pressure sensor operates normally if the value does not exceed the preset pressure range,
Wherein the ECU stops the operation of calculating the fuel temperature in the low pressure section when the fuel tank pressure sensor is determined to be in failure and then increases the delivery pressure of the low pressure pump so that the fuel delivered from the low pressure pump is always constant So as to be output at a higher pressure than the pressure,
Wherein the ECU controls the delivery pressure of the low-pressure pump such that fuel is delivered to the second pressure when it is determined that a failure has occurred in the fuel tank pressure sensor,
The fueling system of the vehicle.
delete delete delete delete Detecting a pressure in the fuel tank with a fuel tank pressure sensor disposed in the fuel tank;
Calculating a fuel temperature in a low-pressure section based on a pressure in the fuel tank; And
Adjusting a fuel delivery pressure of the low-pressure pump based on the fuel temperature in the low-pressure section;
Lt; / RTI >
Wherein the step of controlling the fuel delivery pressure of the low pressure pump controls the delivery pressure of the low pressure pump so that the fuel is delivered to the first pressure when the fuel temperature in the low pressure section is below the reference temperature, Controls the delivery pressure of the low-pressure pump so that the fuel is delivered to a second pressure higher than the first pressure when the temperature of the low-pressure pump exceeds the reference temperature,
Pressure pump is controlled such that the delivery pressure of the low-pressure pump is proportional to the fuel temperature in the low-pressure section, and when the pressure in the fuel tank exceeds a predetermined pressure range, it is determined that a failure has occurred in the fuel tank pressure sensor, It is determined that the fuel tank pressure sensor operates normally if the predetermined pressure range is not exceeded,
When the pressure value output from the fuel tank pressure sensor exceeds the effective range and it is determined that the fuel tank pressure sensor is faulty, the operation of calculating the fuel temperature in the low pressure section is stopped, So that the fuel delivered from the low-pressure pump is always output at a high pressure higher than a predetermined pressure,
And controlling the delivery pressure of the low-pressure pump so that fuel is delivered to the second pressure when it is determined that a failure has occurred in the fuel tank pressure sensor,
A method of driving a fuel supply system of a vehicle.
delete delete delete delete

Images