KR100746916B1 - LFIA vehicle fuel line pressure regulator and monitoring method - Google Patents

Abstract

LIQUEFIED PETROLEUM GAS INJECTION In the vehicle, it is possible to apply the variable pressure regulator that provides the elastic force of the spring and the magnetic force of the electromagnet to adjust the pressure of the fuel line and whether the variable pressure regulator which adjusts the pressure of the fuel line is abnormal. By monitoring

If Elpia detects a start-up while the vehicle is kept off, the main relay and fuel pump relay are turned on, the control of the variable pressure regulator is activated, and the multi-valve disposed in the fuel supply line. And controlling the fuel supply to the injector by opening the shut-off valve, detecting the pressure of the fuel line and comparing it with the target pressure in the current operating conditions extracted from the map table, and the current pressure and the target pressure. The process of adjusting the pressure of the fuel line by controlling the opening and closing of the variable pressure regulating device according to the comparison result and comparing the fuel pressure detected after the pressure adjustment of the fuel line with the pressure detected before the pressure adjustment, the variable pressure And determining whether the control device has failed.

ELPIEY vehicle, injector leak, variable pressure regulator, monitoring

Description

FUEL LINE PRESSURE ADJUSTMENT SYSTEM OF LIQUIFIED PETROLEUM GAS INJECTION VEHICLE AND MONITORING METHOD THEREOF}

1 is a system configuration of a typical Elpia vehicle.

2 is a view showing the configuration of a diaphragm type fuel pressure regulating device applied to a conventional ELPI vehicle.

Figure 3 is a view showing the configuration of a variable pressure regulating device applied to the vehicle Elpia according to the present invention.

4 is a flow diagram of an embodiment of an Elpia performing fuel line monitoring in a vehicle in accordance with the present invention.

The present invention relates to a vehicle (LIQUEFIED PETROLEUM GAS INJECTION) vehicle, and more specifically, to adjust the pressure of the fuel line by applying a variable pressure regulating device provided at the same time the elastic force of the spring and the magnetic force of the electromagnet, the pressure of the fuel line ELPI for monitoring the abnormality of the variable pressure regulating device to adjust the pressure of the vehicle relates to a fuel line pressure adjusting device and a monitoring method.

For example, an Elpia vehicle refers to a vehicle that employs a fuel system in which a fuel pump is installed in a gas cylinder of an existing LPG vehicle to pump LPG in a liquid state to be injected from a gas injector. Responding to environmental regulations and the problems of existing LPG vehicles can be solved.

LPG fuel increases its volume by 250 times when liquid fuel phase changes into the gas phase due to temperature rise or pressure drop.

Therefore, if the phase change of the liquid fuel occurs during engine operation, the engine stop occurs because the amount of fuel actually introduced into the combustion chamber is only 1/250. Therefore, the phase change of the LPG fuel due to radiant heat of the engine during driving (including children) The fuel is injected by pressurizing the fuel in the cylinder so as not to occur.

As shown in FIG. 1, the LPI vehicle includes a fuel supply line 20 and a fuel return line including a cylinder 10 for receiving LPG fuel in a liquid state and an injector 50 mounted in a combustion chamber of the engine 40. Connected to 30.

The fuel supply line 20 is provided with a fuel pump 11 for pressurizing and pumping fuel in the cylinder 10, the multi-valve 12 and the shut-off valve 21 downstream of the fuel pump 11 ) And the fuel temperature sensor 22 are sequentially arranged.

The fuel return line 30 has a pressure regulator 31 for adjusting a pressure of approximately 5 bar in a liquid state to the injector 50 and a fuel pressure sensor for detecting the pressure of the fuel applied to the injector 50 ( 32) is arranged.

The injector 50, the fuel pump 11, the multivalve 12, the shutoff valve 21, the fuel temperature sensor 22, and the fuel pressure sensor 32 are connected to the electronic control unit 90 via an interface 80. Is electrically connected and controlled.

In addition, the intake cylinder 60 includes an intake air temperature sensor 61 for detecting the temperature of the air flowing into the combustion chamber, a map sensor 62 for detecting the amount of air, an idle speed actuator 63, and a throttle operated in conjunction with the accelerator pedal. The throttle position sensor 64 etc. which detect the opening degree of a valve are provided.

The exhaust system 70 includes an oxygen sensor 71, and the engine 40 itself cranks the position of the crankshaft in the state where the water temperature sensor 41 for detecting the temperature of the cooling water and the engine 40 are operated. 42 and the like.

Each component mounted in the intake system 60, the exhaust system 70, and the engine 40 supplies information necessary for engine operation to the electronic control unit 90 or according to a control signal of the electronic control unit 90. Controlled operation ensures optimal operation.

The pressure regulating device 31 disposed in the fuel return line 30 allows the pressure on the fuel supply line 20 to be maintained approximately 5 bar higher than the pressure inside the cylinder 10.

2, a fuel outlet pipe 31B is formed at the lower center of the valve housing 31A to maintain airtightness at the fuel outlet end of the regulator housing. It is fitted in the state, a plurality of fuel inlet 31C is formed around the lower fuel outlet pipe (31B) of the valve housing (31A) is disposed corresponding to the fuel inlet end of the regulator housing.

The diaphragm 31D is installed in the center of the valve housing 31A to divide the inside of the valve housing 31A into a diaphragm chamber C1 and a fuel inlet chamber C2, and the diaphragm 31D A valve 31E is installed at the fuel inlet chamber C2 side.

That is, the fuel outlet pipe 31B has an upper end thereof disposed in the fuel inlet chamber C2, and the valve 31E has the valve seat 31F mounted on its lower surface. 31F), the fuel outlet pipe 31B can be opened and closed.

A spring 31G is installed in the diaphragm seal C1 of the valve housing 31A, and the spring 31G is supported by an upper spring seat 31H whose upper end is installed on the upper inner surface of the valve housing 31A. The lower end is supported by the lower spring seat 31I installed at the upper end of the valve 31E to provide a constant elastic force to the valve 31E.

In addition, a pin groove 31J is formed inward at an upper center of the valve 31E, and a core pin 31K is vertically installed at a center of the upper spring seat 31H to be fitted into the pin groove 31J. It is configured to guide the up and down operation of the valve 31E in the state.

Therefore, the conventional pressure regulator 31 having the above configuration has a constant elastic modulus of the spring 31G, and the pressure of the fuel flowing into the fuel inlet 31C returned from the injector 50 is increased. When the elastic force of the spring 31G is overcome, the valve 31E opens the fuel outlet pipe 31B by pushing up the diaphragm 31D, whereby the fuel is returned to the cylinder 10.

On the other hand, if the pressure of the supplied fuel does not overcome the elastic force of the spring (31G), the diaphragm (31D) can not be pushed up, the valve (31E) maintains the fuel outlet pipe (31B) closed fuel supply line The pressure of the fuel in (20) is kept constant.

For example, if the elasticity modulus of the spring 31G is set so that the valve 31E can be pushed up when the fuel pressure in the fuel supply line 20 is 5 Bar or more (the current LPI mass production model is set to 5 Bar). When the pressure of the fuel flowing into the fuel inlet 31C is 5 Bar or more, the valve 31E opens the fuel outlet pipe 31B and the fuel is returned to the cylinder 10.

However, when a fuel pressure of less than 5 Bar is applied to the fuel inlet 31C, the valve 31E closes the fuel outlet pipe 31B so that fuel is not returned to the cylinder 10.

In the pressure regulator according to the related art, when the elastic modulus of the spring 31G is determined, the fuel pressure in the fuel supply line 20 is fixed, and thus the pressure regulator 31 is required by the system. There is a disadvantage that the set pressure of) cannot be changed.

In other words, if the set pressure of the pressure regulator 31 in the vehicle is fixed to 5 Bar, all systems are designed for 5 Bar while the engine is running, but on the fuel supply line 20 disposed in the engine room area when the engine is stopped. In the process of increasing the temperature of the fuel due to the internal heat of the engine room, the injector 50 or the injector 50 and the connection between the fuel supply line 20 has a problem that the possibility of leakage of fuel (Leak) is increased.

Of course, even when the engine is stopped, if the fuel pressure in the fuel supply line 20 rises to the pressure set in the pressure regulator 31, the valve 31E of the pressure regulator 31 is connected to the fuel outlet pipe 31B. The fuel is returned to the cylinder 10 to lower the pressure, but the problem of temporary fuel leakage through the injector 50 is eliminated by the increase in the fuel pressure in the fuel supply line 20 until the set pressure. The disadvantage is that it can't be.

In addition, in the conventional ELPAI vehicle equipped with the above-described pressure regulation politics, it is possible to determine whether the fuel pressure for the fuel supply line 20 between the cylinder 10 and the shutoff valve 21 is normal, but shut off. The normality of the pressure on the fuel line reaching the pressure regulator 31 and the cylinder 10 and the injector 50 of the engine 40 without passing through the valve 21 has a problem that cannot be determined.

The present invention has been invented to solve the above problems, the object of the Elpia is equipped with a variable pressure regulating device for adjusting the pressure of the fuel line by the elastic force of the spring and the magnetic force of the electromagnet, In conjunction with the control, it is determined whether the fuel pressure is normal or abnormal in all sections of the fuel line.

In addition, when the fuel pressure in the fuel line rises above or below a certain value, the limp home logic is activated to protect the vehicle and engine by considering a serious leak in the fuel line or judging it as an injector. It was made possible.

The present invention for realizing the above object is an engine, a fuel pump is disposed, LPG is filled with a fuel cylinder, an injector mounted between the engine and the fuel supply line and the fuel return line, fuel connected to the fuel pump An Elpia vehicle comprising a multi-valve and a shut-off valve sequentially disposed in a supply line, a pressure regulator disposed in a fuel return line, and a temperature sensor disposed in a fuel supply line to detect fuel temperature.

The pressure regulating device disposed in the fuel return line is applied as a variable pressure regulating device for adjusting the pressure of the fuel line by the elastic force of the spring and the magnetic force of the electromagnet. The pressure of the fuel line is detected and compared with the target pressure. Fuel line pressure control device of the Elpia vehicle, characterized in that it comprises a control unit for controlling the pressure of the fuel line through the control of the pressure regulator and then comparing the adjusted pressure and the previous pressure to diagnose the abnormality of the fuel line. To provide.

In addition, the present invention includes the step of turning on the main relay and the fuel pump relay when the start-up is detected in the state in which the vehicle maintains the start-up of the Elpia, and enters the state of the control of the variable pressure regulator to the activation state; Controlling the fuel supply to the injector by opening the multi-valve and the shut-off valve disposed in the fuel supply line; Detecting a pressure of the fuel line and comparing the target pressure with a target pressure at a current operating condition extracted from the map table; Controlling the pressure of the fuel line by controlling the opening and closing of the variable pressure regulating device according to the comparison result between the current pressure and the target pressure; And comparing the fuel pressure detected after the pressure adjustment of the fuel line with the pressure detected before the pressure adjustment, and determining whether the variable pressure regulating device is broken. Provide monitoring methods.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Since the system of the Elpia vehicle according to the present invention is the same or similar to the structure mentioned in the prior art, a detailed description thereof will be omitted.

Figure 3 is a view showing the configuration of a variable pressure regulating device applied to the vehicle Elpia according to the present invention.

In the variable pressure regulating device 101 according to the present invention disposed on the fuel return line, a valve height 103 is installed.

The valve housing 103 has a fuel outlet pipe 105 formed at a lower center thereof, and a plurality of fuel inlets 107 are formed around the fuel outlet pipe 105, and the fuel outlet pipe 105 is illustrated. The fuel inlet 107 is fitted in a state of being airtightly installed at the fuel outlet end of the unregulated regulator housing, and the fuel inlet 107 is disposed corresponding to the fuel inlet end of the not shown regulator housing.

In addition, a diaphragm 109 is installed at an inner center of the valve housing 103 to divide the inside of the valve housing 103 into a diaphragm chamber C1 and a fuel inflow chamber C2.

In the center of the diaphragm 109, a valve 111 is installed to penetrate the diaphragm 109, and the valve 111 is disposed across the diaphragm chamber C1 and the fuel inlet chamber C2, so that the diaphragm 109 is provided. Is fixed to.

That is, the valve 111 has a valve seat 113 for opening and closing the fuel outlet pipe 105 in the fuel inlet chamber C2 on the lower surface thereof, the upper portion of which is disposed in the center of the diaphragm chamber C1. The extension portion 115 of the metal material is formed integrally.

A spring groove 117 is formed in the center of the extension part 115, and a pin groove 119 is formed inside the spring groove 117.

Here, the spring groove 117 is formed as a circular groove having a larger diameter than the pin groove 119.

In addition, an electromagnet 121 is inserted into the extension part 115 of the valve 111 in the diaphragm chamber C1, and the support 123 of which the upper end of the electromagnet 121 is formed on the upper inner surface of the valve housing 103. The magnetic force is generated in the direction in which the valve 111 is closed through the extension 115 when the power is supplied.

Here, the connector 127 connecting the power supply terminal 125 may be configured at one side of the valve housing 103 so as to supply power to the electromagnet 121.

A spring 129 is inserted into the spring groove 117 of the valve 111, and an upper end of the spring 129 is supported by the support 123, and a lower end thereof is an inner surface of the spring groove 117 of the valve 111. Install to support

In addition, the core pin 131 is fixedly installed at the center of the support 123 through the upper end thereof, and the lower end of the core pin 131 is inserted into the pin groove 119 through the spring groove 117 of the valve 111. It is configured to guide the vertical operation of the valve 111 in the closed state.

At this time, the spring 129 is preferably made of a coil spring so that the core pin 131 can be fitted.

The spring 129 itself is set so that the elastic coefficient of the fuel line can open the valve 111 to return the fuel to the cylinder at a pressure lower than the set pressure, approximately 5 bar.

In addition, the electromagnet 121 assists the elastic force of the spring 129 to open the valve 111 at a pressure lower than the set pressure of the fuel line when the engine is driven, thereby controlling the valve 111 according to the control of the electronic control unit. By generating a magnetic tension in the direction of closing the valve 111 is operated to suppress the opening of the valve 111 until the fuel pressure supplied to the fuel inlet 107 reaches a set pressure.

When the power supply to the electromagnet 121 is connected to the fuel pump relay and the IG key is turned on, the main relay MAIN RELAY and the fuel pump relay are turned on in the electronic control unit. (ON) so that power is applied, and when the power is off, when the IG key is turned off, the electronic control unit is preferably configured to cut off the power by turning off the main relay and the fuel pump relay.

The basic concept of the variable pressure regulating device 101 is that after the engine is turned off, the magnetic tension of the electromagnet 121 is dissipated so that the pressure in the fuel supply line can be returned to the cylinder even at a pressure lower than the set pressure. To ensure that

In addition, the fuel in the fuel supply line disposed in the engine area after the engine stops increases the fuel pressure due to the temperature rise, but the fuel return set pressure of the variable pressure regulating device 101 is only set according to the elastic force of the spring 129. Since the fuel pressure is not increased in the fuel supply line disposed inside the engine room, and the fuel pressure rises to a predetermined pressure level determined by the spring 129, the fuel pressure increases through the variable pressure regulator 101. Return to bombe side.

As a result, the fuel pressure in the fuel supply line is formed at a lower fuel pressure than when starting, so that fuel leakage through the injector can be prevented in advance, thereby reducing the exhaust gas (EM) when the engine is restarted.

Referring to Figure 4 with respect to the monitoring operation of the fuel line in the Elpia vehicle equipped with the variable pressure regulator described above as follows.

In a state in which the engine starts to be off (S101), it is determined whether the engine start-on by the ignition key is detected (S102).

When the engine start-on is detected, the electronic control unit turns on the main relay contact and the fuel pump relay contact, and activates the control of the variable pressure regulator 101 (S103).

Thereafter, the multi-valve disposed on the bombe side and the shut-off valve disposed on the fuel supply line are opened (S104) to perform fuel supply to the injectors arranged in the engine (S105).

As the fuel is supplied to the injector as described above, the pressure of the fuel distributed in the fuel supply line and the fuel return line is detected and compared with the set target pressure (S106).

As a result of the comparison in S106, it is determined whether the pressure of the currently detected fuel line has a value less than or equal to the set target pressure (S107). If the state is less than or equal to the target pressure, the electronic control unit is configured to operate the variable pressure regulator. By reducing the control to close the variable pressure regulator to increase the pressure of the fuel line (S108).

After closing the variable pressure regulator as described above, the pressure of the fuel line is detected (S109), and the current pressure is previously detected by comparing the currently detected pressure with the detected pressure before closing the variable pressure regulator. It is determined whether the value is smaller than the pressure (S110).

If the present pressure is not a state having a value less than the pressure previously detected, the process returns to step S107, and if the current pressure has a value less than the previously detected pressure, the electronic control unit adjusts the variable pressure. It is determined by the open fixation (short circuit) of the apparatus or the failure of the injector (S111).

Thereafter, the fault code is stored, and then the lymph groove mode is performed to protect the engine (S112).

However, if the current pressure detected in the fuel line is not determined to be lower than or equal to the set target pressure in the determination of S107, it is determined whether to maintain the target pressure or more (S113).

If it is determined in S113 that the current pressure is equal to or higher than the set target pressure, the duty of operating the variable pressure regulator is increased to control the opening of the variable pressure regulator, thereby lowering the pressure of the fuel line (S114).

When the control to lower the pressure of the fuel line is performed by opening the valve of the variable pressure regulator as described above, the pressure of the fuel line is detected (S115) and it is determined whether the current pressure is higher than the previously detected pressure (S116). ).

As a result of the determination of S116, if the current pressure is higher than the previously detected pressure, the flow returns to S113. If the current pressure is lower than the previously detected pressure, the closed pressure (disconnection) or fuel system of the variable pressure regulator is closed. It is determined that there is a serious leak in (S117).

Thereafter, the fault code is outputted therefor and then the lymphatic groove mode is performed (S118).

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible.

As described above, in the present invention, Elpia applies the variable pressure control device in the vehicle to actively adjust the pressure in the fuel line, thereby preventing the injection pressure from the injector and the leakage from the injector after the engine is turned off, thereby ensuring the stability of the vehicle. And reliability.

In addition, by monitoring the pressure of the fuel line to diagnose the abnormality of the variable pressure control device, Elpia has the effect of providing a diagnosis on the fuel system of the vehicle.

Claims (8)

A fuel cylinder in which the engine and the fuel pump are disposed and the LPG is filled, an injector mounted on the engine and disposed between the fuel supply line and the fuel return line, and a multi-valve and a shutter arranged sequentially in the fuel supply line connected to the fuel pump. An Elpia vehicle comprising an off valve, a pressure regulator disposed on a fuel return line, and a temperature sensor disposed on a fuel supply line to detect a fuel temperature. The pressure regulating device disposed in the fuel return line is applied as a variable pressure regulating device for adjusting the pressure of the fuel line by the elastic force of the spring and the magnetic force of the electromagnet, The control unit detects the pressure of the fuel line and compares it with a target pressure, and then adjusts the pressure of the fuel line through the control of the variable pressure regulator, and then compares the adjusted pressure with the previous pressure to diagnose whether the fuel line is abnormal. Fuel line pressure regulating device of an Elpia vehicle comprising a. The method of claim 1, When the pressure of the fuel line is lower than the set target pressure, the control unit closes the variable pressure regulating device so that the pressure of the fuel line is increased, and before the pressure and pressure increase control detected after the pressure of the fuel line is increased. Compared to the pressure of the, if the previous pressure is higher than the current pressure is determined by the open fastening of the variable pressure control device or the failure of the injector and outputs a fault code, characterized in that the fuel line pressure regulator of the ELP eye vehicle. The method of claim 1, When the pressure of the fuel line is higher than the set target pressure, the controller controls the opening of the variable pressure regulator so that the pressure of the fuel line is lowered, and before the pressure and pressure lowering control detected after controlling the pressure of the fuel line to be lowered. When the current pressure is higher than the pressure before the descent control, it is determined that the variable pressure regulator is closed or the fuel system is leaked, and the fault code is output. Regulator. Turning on the main relay and the fuel pump relay when the Elpia detects the start-up while the vehicle maintains the start-off, and enters the control of the variable pressure regulator into an active state; Controlling the fuel supply to the injector by opening the multi-valve and the shut-off valve disposed in the fuel supply line; Detecting a pressure of the fuel line and comparing the target pressure with a target pressure at a current operating condition extracted from the map table; Controlling the pressure of the fuel line by controlling the opening and closing of the variable pressure regulating device according to the comparison result between the current pressure and the target pressure; And comparing the fuel pressure detected after the pressure adjustment of the fuel line with the pressure detected before the pressure adjustment, and determining whether the variable pressure regulating device is broken. Monitoring method. The method of claim 4, wherein If the pressure of the fuel line is less than a target pressure, controlling the pressure of the fuel line to increase by closing the variable pressure regulating device under duty control; Comparing the fuel pressure detected after the pressure rise control of the fuel line with the pressure before the pressure rise control; As a result of the comparison, if the fuel pressure detected after the pressure increase control is higher than the previous pressure, the variable pressure regulator is determined to be normal. If the pressure detected after the pressure increase control is lower than the previous pressure, the variable pressure regulator is determined. The method of monitoring the fuel line pressure regulator of an Elpia vehicle, characterized in that it comprises the step of outputting a failure code by determining that the open stuck. The method of claim 4, wherein If the pressure of the fuel line is greater than or equal to a target pressure, controlling the pressure of the fuel line to be lowered by opening a variable pressure regulator by duty control; Comparing the fuel pressure detected after the pressure drop control of the fuel line with the pressure before the pressure drop control; As a result of the comparison, if the fuel pressure detected after the pressure drop control is higher than the previous pressure, the variable pressure regulator is determined to be normal. If the pressure detected after the pressure drop control is lower than the previous pressure, the variable pressure is adjusted. A method for monitoring the fuel line pressure regulator of an Elpia vehicle, comprising: determining that the device is closed and outputting a fault code and performing a limp home mode. The method of claim 4, wherein As a result of comparing the fuel pressure detected after the pressure rise control of the fuel line and the pre-control pressure through the closing control of the variable pressure regulating device, if the pressure detected after the pressure rise control is lower than the previous pressure, it is determined that the injector is broken. Fuel line pressure regulator monitoring method for an Elpia vehicle, characterized in that it comprises a step of outputting a fault code. The method of claim 4, wherein When the pressure detected after the pressure lowering control is lower than the previous pressure as a result of comparing the fuel pressure detected after the pressure lowering control of the fuel line through the opening control of the variable pressure regulating device, the oil leakage path of the fuel system And determining and outputting a failure code.

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