KR19990085836A - Electronically Controlled Fuel Injector and Injection Method for LPI / Gasoline Combined Vehicle - Google Patents

Abstract

The electronically controlled fuel injector 100 of the LPG / gasoline combined vehicle according to the present invention outputs various control signals including a gasoline fuel ignition timing and fuel injection amount according to signals input from various switches and sensors provided to the vehicle. Gasoline control ECU 106; An injector for supplying a predetermined amount of gasoline fuel to a cylinder according to a fuel injection amount control signal output from the gasoline control ECU 106 during a gasoline fuel use mode; A power LPG control ECU 122 connected to an output side of the gasoline control ECU 106 for receiving a signal output from the gasoline control ECU 106 and outputting various control signals including an LPG fuel ignition timing and a fuel injection amount; And a duty solenoid valve 120 for supplying a predetermined amount of LPG fuel to the cylinder according to a fuel injection amount control signal output from the power LPG control ECU 122 in the LPG fuel use mode.

Description

Electronically Controlled Fuel Injector and Injection Method for LPI / Gasoline Combined Vehicle

The present invention relates to a fuel injector and an injection method for an LPG / gasoline combined vehicle, and in particular, to improve the engine power and to effectively perform the fuel cut function by performing fuel correction for each control section according to the engine performance curve. Electronically controlled fuel injectors and injection methods for LPG / gasoline combined vehicles that can be used in a variety of vehicles that improve fuel economy and enable different fuel injection systems by reducing emissions and enabling precise control of the ignition timing. method for injecting fuel in an electronically controlled manner in LPG / gasoline vehicle.

Typically, gasoline, diesel, or LPG is used as a fuel for automobiles, which burns hotter and cleaner than gasoline or diesel. LPG is highly volatile and must be stored in special tanks to prevent rapid evaporation into the atmosphere. LPG, a hydrocarbon compound, emits more energy and produces less emissions than gasoline or diesel fuel. Therefore, at present, there are few cases of using LPG as fuel except for some vehicles, but it is expected that the use of LPG vehicles will be increased in the future due to the inherent advantages of LPG.

1, there is shown a block diagram showing the configuration of a fuel injector for a vehicle dedicated to LPG according to the prior art. The fuel injector of the LPG dedicated vehicle includes an LPG cylinder 20, an LPG solenoid valve 22, a filter 24, a preheater 26, a vaporizer 28, and a mixer 30. LPG cylinder 20 is a tank for storing LPG, LPG cylinder 20 is provided with a gas LPG discharge valve and a liquid LPG discharge valve. The LPG solenoid valve 22 is an LPG shutoff valve that can be operated from the driver's seat, and the filter 24 is installed below the LPG solenoid valve 22 to filter impurities contained in the LPG. The preheater 26 supplies a predetermined latent heat of evaporation to the LPG, that is, part or all of the LPG is vaporized using the coolant heat to supply to the vaporizer 28. The vaporizer 28 converts the liquid LPG into gas LPG by reducing the pressure, and the mixer 30 serves as a vaporizer of a gasoline engine as a device for mixing LPG vaporized in the vaporizer 28 with air and supplying it to each cylinder. .

In recent years, in order to combine the inherent advantages of LPG, there has been a tendency to change the structure of the LPG / gasoline combined vehicle. 2, there is shown a block diagram showing the configuration of a fuel injector for an LPG / gasoline combined vehicle according to the prior art. The fuel injector of the LPG / gasoline combined vehicle according to the prior art includes an LPG portion and a gasoline portion. The LPG unit includes an LPG cylinder 20, an LPG solenoid valve 22, a filter 24, a vaporizer 28, a mixer 30, an LPG control ECU 32 and a duty solenoid valve 34. Since the functions of the components other than the LPG control ECU 32 and the duty solenoid valve 34 have been described above in the case of the LPG dedicated vehicle, the description thereof will be omitted with reference to FIG. 2. The gasoline portion includes a gasoline tank 36, a gasoline pump 38, a gasoline control ECU 40 and an injector 42.

The gasoline tank 36 is a tank for storing gasoline fuel, and the gasoline pump 38 functions to pump gasoline fuel from the gasoline tank 36. The gasoline control ECU 40 outputs various control signals including gasoline fuel ignition timing and fuel injection amount according to signals input from various switches and sensors provided to the vehicle. The injector 42 supplies a predetermined amount of gasoline fuel to the cylinder in accordance with the fuel injection amount control signal output from the gasoline control ECU 40 during the gasoline fuel use mode. The LPG control ECU 32 is connected to the output side of the oxygen sensor and the throttle position sensor (TPS) to receive a signal input to the gasoline control ECU 40, including various LPG fuel ignition timing and fuel injection amount Output a control signal. The duty solenoid valve 34 supplies a predetermined amount of LPG fuel to the cylinder in accordance with the fuel injection amount control signal output from the LPG control ECU 32.

However, in the fuel injector of the LPG / gasoline combined vehicle according to the prior art structured as described above, in comparison with a gasoline-only vehicle, the output is lowered and sometimes ignited as a burning phenomenon other than combustion prescribed in the backfire. It may be caused by poor timing or abnormal valve timing, but sometimes the air cleaner may be lit.), which may cause engine damage by causing air cleaner or air volume sensor failure, and fuel-cut function: It refers to the function to temporarily stop the fuel injection signal from the ECU when the fuel injection signal is determined according to each sensor signal or the load state, and the fuel injection signal is temporarily stopped. Since there is a lot of hydrocarbon gas at this point, all vehicles The fuel cut function is dependent on the coolant temperature and the lower the coolant temperature, the higher the fuel cut-off speed). Accordingly, the LPG / gasoline combined vehicle according to the prior art is not only satisfactory in exhaust speed, acceleration performance, and climbing performance due to the three disadvantages of the fuel injector, but also exhaust gas discharge is not satisfactory.

In addition, in the LPG / gasoline combined vehicle according to the prior art, not only the time for controlling the duty solenoid valve by using the feedback signal is long, but also the response is low and the feedback is not made accurately, especially the output of the hill section is significantly reduced. It becomes difficult to achieve the top speed.

The reason why the output of the existing LPG / gasoline combined vehicle is lowered is that fuel correction is not performed according to the engine output curve in the LPG control ECU. In general, 1500cc to 2000cc of difference in output torque is generated at an engine RPM of 2500 to 3000, and the amount of correction at this time is not accurate. Comparing at low speed, it is between about 80 and 100 km / h. In addition, between 120 km / h to 140 km / h can be seen as the most difficult section, in this section, the LPG control ECU should be fuel correction according to the control section by receiving signals from various sensors. LPG / gasoline combined vehicles according to the prior art will not be corrected correctly in the section.

Typically, backfire occurs when the mixing ratio is 0.7 or less, or 1.3 or more, which is one of the pulses used to determine the average value of the ON time by repeating ON and OFF according to the duty control (ECU pulse signal) even when the duty solenoid valve is mounted. Is the duty value, and the duty cycle is controlled by changing this duty value.) It should be sensitive to RPM fluctuations and control should be made according to the oxygen sensor signal. In some cases, the bigger one is ignition advance or ignition delay due to RPM variation, which results in backfire due to improper fuel injection timing. To solve this problem, duty control should be performed based on the signals of various sensors, because the existing LPG / gasoline combined vehicles perform duty control only with the oxygen sensor signal and the throttle position sensor signal. If flashback occurs, the parts will be damaged, fuel economy will be poor, and there is a risk of fire.

In addition, the existing LPG / gasoline combined vehicles perform duty control only with the oxygen sensor signal and the throttle position sensor signal, and thus the fuel cut function cannot be provided, thereby increasing the hydrocarbon (HC) emission, especially at low speeds. It is not desirable for environmental protection.

Therefore, the present invention was created to solve the problems inherent in the fuel injection structure of the LPG / gasoline combined vehicle according to the prior art as described above, and the main object of the present invention is fuel compensation for each control section according to the engine performance curve. This ensures that the engine output is improved and the fuel cut function can be carried out effectively, thereby reducing fuel emissions and allowing precise control of the ignition timing, thereby improving fuel economy. And to provide a spraying method.

It is another object of the present invention to provide an electronically controlled fuel injector and an injection method for an LPG / gasoline combined vehicle that can be used in all vehicles employing any one of the group injection method, the independent injection method, and the simultaneous injection method. Is in.

It is still another object of the present invention to provide an electronically controlled fuel injection device and injection method for an LPG / gasoline combined vehicle that can replace an existing LPG control ECU mounted on an LPG / gasoline combined vehicle at a low price.

1 is a block diagram showing the configuration of a fuel injector for an LPG vehicle according to the prior art.

Figure 2 is a block diagram showing the configuration of the fuel injector of the LPG / gasoline combined vehicle according to the prior art.

Figure 3 is a block diagram showing the configuration of an electronically controlled fuel injector of LPG / gasoline combined vehicle according to the present invention.

4 is a circuit diagram showing a circuit configuration of an electronically controlled fuel injector of an LPG / gasoline combined vehicle according to the present invention.

5 is a block diagram illustrating a signal transmission system of an electronically controlled fuel injector of an LPG / gasoline combined vehicle according to the present invention.

6 is a system diagram showing the function of the gasoline control ECU of FIG.

7 is a flowchart illustrating a process of controlling the fuel injection timing and the fuel injection amount by the ECU of FIG.

8 is a schematic diagram illustrating a process in which an air-fuel ratio feedback correction is performed by a gasoline control ECU.

9 is a system diagram showing a feedback system for a gasoline control ECU.

10 to 12 are graphs showing engine fuel injection performance test results at 840 rpm, 1310 rpm, and 4700 rpm in a combined LPG / gasoline vehicle according to the prior art.

13 to 15 are graphs showing engine fuel injection performance test results at 760 rpm, 860 rpm, and 1640 rpm in the LPG / gasoline combined vehicle according to the present invention.

Explanation of symbols on the main parts of the drawings

20: LPG cylinder 22: LPG solenoid valve

24: Filter 26: Preheater

28: Vaporizer 30: Mixer

32: LPG Control ECU 34: Duty Solenoid Valve

36: gasoline tank 38: gasoline pump

40: gasoline control ECU 42: injector

100: electronically controlled fuel injection device 102: gasoline tank

104: gasoline pump 106: gasoline control ECU

108: injector 110: LPG cylinder

112: LPG solenoid valve 114: filter

116: Vaporizer 118: Mixer

120: duty solenoid valve 122: power LPG control ECU

124: microcomputer 126: coil

128: first driving circuit 130: waveform shaping circuit

132: I / O LSI 134: ROM

136: RAM 138: CPU

140: security circuit 142: second drive circuit

144: air flow meter 146: engine

148: three-way catalyst 150: oxygen sensor

According to one aspect of the present invention, there is provided an electronically controlled fuel injector for an LPG / gasoline combined vehicle: the injector includes a gasoline fuel ignition timing and fuel injection amount according to signals input from various switches and sensors provided in the vehicle. A gasoline control ECU for outputting various control signals; An injector for supplying a predetermined amount of gasoline fuel to a cylinder according to a fuel injection amount control signal output from the gasoline control ECU during a gasoline fuel use mode; A power LPG control ECU connected to an output side of the gasoline control ECU for receiving a signal output from the gasoline control ECU and outputting various control signals including LPG fuel ignition timing and fuel injection amount; And a duty solenoid valve for supplying a predetermined amount of LPG fuel to the cylinder according to a fuel injection amount control signal output from the power LPG control ECU in the LPG fuel use mode.

According to another aspect of the present invention, the power LPG control ECU is provided with a microcomputer for accurately controlling the total amount of LPG fuel supplied to the cylinder by reading the fuel injection method according to the vehicle type in accordance with the signal output from the gasoline control ECU To; Accordingly, the power LPG control ECU can be shared by all vehicles employing any one of the group injection method, the independent injection method, and the simultaneous injection method.

According to another aspect of the present invention, the signal input to the gasoline control ECU is a throttle valve switch, start switch, air conditioner switch, neutral switch, intake temperature sensor, exhaust temperature sensor, coolant temperature sensor, vehicle speed sensor, battery voltage, oxygen sensor , Signal from the air flow meter, crank angle sensor.

According to another aspect of the present invention, there is provided an electronically controlled fuel injection method for an LPG / gasoline combined vehicle: the injection method ignites gasoline fuel in accordance with signals input to the gasoline engine control ECU from various switches and sensors provided to the vehicle. Outputting various control signals including timing and fuel injection amount from the gasoline engine control EUC; Supplying a predetermined amount of gasoline fuel to a cylinder according to a fuel injection amount control signal output from the gasoline control ECU to the injector during the gasoline fuel use mode; Outputting various control signals including LPG fuel ignition timing and fuel injection amount by a power LPG control ECU connected to an output side of the gasoline control ECU and receiving a signal output from the gasoline control ECU; And supplying a predetermined amount of LPG fuel to the cylinder according to a fuel injection amount control signal output from the power LPG control ECU to the duty solenoid valve during the LPG fuel use mode.

According to another aspect of the present invention, the method comprises the steps of always accurately controlling the total amount of LPG fuel supplied to the cylinder by reading the fuel injection method according to the vehicle type according to the signal output from the gasoline control ECU; It is further provided.

According to another aspect of the present invention, the power LPG control ECU can be shared by all vehicles employing any one of the group injection method, the independent injection method and the simultaneous injection method.

According to another aspect of the invention, the signal input to the gasoline control ECU is a throttle valve switch, start switch, air conditioner switch, neutral switch, intake temperature sensor, exhaust temperature sensor, coolant temperature sensor, battery voltage, oxygen sensor, vehicle speed Includes signals from sensors, air flow meters, and crank angle sensors.

According to the above characteristics of the present invention, by using the power LPG control ECU in the LPG / gasoline combined vehicle, the power LPG control ECU receives a signal output from the gasoline control ECU to control various types including the LPG fuel ignition timing and fuel injection amount Since the signal is output, fuel correction can be made precisely for each control section according to the engine performance curve, so that the engine output is improved, the fuel cut function can be effectively performed, the emission gas is reduced, and precise control of the ignition timing It becomes possible and improves fuel economy.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention, the same reference numerals will be used for the same parts throughout the drawings.

3, a block diagram showing a configuration of an electronically controlled fuel injector of an LPG / gasoline combined vehicle according to the present invention is shown; Figure 4 shows a circuit diagram showing the circuit configuration of the electronically controlled fuel injector of the LPG / gasoline combined vehicle according to the present invention; 5 is a block diagram illustrating a signal transmission system of an electronically controlled fuel injector of an LPG / gasoline combined vehicle according to the present invention.

Electronic air fuel injection device 100 of the combined LPG / gasoline vehicle according to the present invention includes a gasoline unit and LPG unit. The gasoline portion includes a gasoline tank 102, a gasoline pump 104, a gasoline control ECU 106 and an injector 108. The LPG unit includes an LPG cylinder 110, an LPG solenoid valve 112, a filter 114, a vaporizer 116, a mixer 118, a duty solenoid valve 120, and a power LPG control ECU 122.

The gasoline tank 102 is a tank for storing gasoline fuel, and the gasoline pump 104 pumps gasoline fuel from the gasoline tank 102 and compresses the gas to high pressure, thereby injecting the fuel to the injector 108 of each cylinder in the order of injection. It acts as a pump. The gasoline control ECU 106 outputs various control signals including the gasoline fuel ignition timing and fuel injection amount according to signals input from various switches and sensors provided to the vehicle. The injector 108 supplies a predetermined amount of gasoline fuel to the cylinder in accordance with the fuel injection amount control signal output from the gasoline control ECU 106 during the gasoline fuel use mode. Signals input to the gasoline control ECU 106 are throttle valve switch, start switch, air conditioner switch, neutral switch, intake temperature sensor, exhaust temperature sensor, coolant temperature sensor, battery voltage, oxygen sensor, vehicle speed sensor, air flow meter, crank It includes a signal input from each sensor.

LPG cylinder 110 is a tank for storing LPG, LPG cylinder 110 is provided with a gas LPG discharge valve and a liquid LPG discharge valve. The LPG solenoid valve 112 is an LPG shutoff valve that can be operated from the driver's seat, and the filter 114 is installed below the LPG solenoid valve 112 to filter impurities contained in the LPG. The vaporizer 116 converts the liquid LPG into a gas LPG by depressurizing it, and the mixer 118 mixes the vaporized LPG in the vaporizer 116 with air to supply each cylinder. The power LPG control ECU 122 is connected to the output side of the gasoline control ECU 106 and receives a signal input from the gasoline control ECU 106 to output various control signals including the LPG fuel ignition timing and the fuel injection amount. The duty solenoid valve 120 supplies a predetermined amount of LPG fuel to the cylinder according to the fuel injection amount control signal output from the power LPG control ECU 122 during the LPG fuel use mode.

As illustrated in FIG. 4, the power LPG control ECU 122 includes a microcomputer 124, a coil 126, and a first driving circuit 128. The coil 126 provides the same resistance value to the gasoline control ECU 106 when switching from the gasoline fuel usage mode to the LPG fuel usage mode, thereby allowing the gasoline control ECU 106 to continue to operate. The microcomputer 124 reads the fuel injection method according to the vehicle type according to the signal output from the gasoline control ECU 106 to accurately control the total amount of LPG fuel supplied to the cylinder. Therefore, the power LPG control ECU 122 can be shared by all vehicles employing any one of the group injection method, the independent injection method, and the simultaneous injection method. The first driving circuit 128 amplifies and outputs the signal output from the microcomputer 124 to the duty solenoid valve 120.

6, there is shown a system diagram showing the function of the gasoline control ECU of FIG. 3; 7 shows a flow chart showing a process in which a gasoline control ECU controls fuel injection timing and fuel injection amount; 8 shows a schematic diagram illustrating a process in which an air-fuel ratio feedback correction is made by a gasoline control ECU; 9 shows a system diagram showing a feedback system for a gasoline control ECU.

The gasoline control ECU 106 includes a waveform shaping circuit 130, an input / output large scale integrated circuit (LSI) 132, a ROM 134, a RAM 136, a CPU 138, and a security circuit 140. ) And a second driving circuit 142.

The information (input signal) of various sensors for detecting various situations of the vehicle is input to the input / output LSI 132 after the noise is removed from the waveform shaping circuit 130 and the signal level is adjusted. The input / output LSI 132 converts each input signal into a binary signal that can be understood by a computer, and analog signals such as intake air amount are converted into digital signals by an analog / digital converter.

In the ROM 134, an execution order program of logic executed by the central processing unit (CPU) 138 and data for control calculation are recorded. The CPU 138 receives a program or data of the ROM 134 or an input signal of the input / output LSI 132 and calculates and generates an output signal necessary for control. The I / O data and the data during the operation are temporarily stored in the RAM 136 and retrieved when necessary. The output signal output from the CPU 138 is sent to the input / output LSI 132, converted into a pulse width signal and a switch signal in the output circuit of the input / output LSI 132, and then amplified by the second driving circuit 142. Output to actuators such as solenoid valves, relays, and amplifiers. The operation of the CPU 138 is performed in units of 8 bits (2 ⁸ = 256).

The gasoline control ECU 106 performs a self-diagnosis function to perform self-check when a self-check signal is input from an electronic concentrated control system (ECCS) checker in addition to the above-described control operation. In addition, the security circuit 140 is provided with an abnormal control due to abnormal radio noise, etc. immediately detects it and performs a so-called fail safe function to return the control program to a normal state.

The CPU 138 can only calculate once per engine revolution, and this calculation proceeds very quickly. First, the basic injection amount is calculated within 10ms based on the latest information necessary for control, and then the control signal of the ignition time and energization time is output at the engine speed at the crank angle of 120 °. Then, the fuel injection amount correction calculation is performed at about 360 ° of the crank angle, the fuel injection control signal is output, the idle control signal is calculated, the calculation result is output, and EGR (exhaust gas recirculation) control is performed. Calculate the signal and output the calculation result. In addition, it calculates and outputs the control of the ignition advance energization time. The total time required to run all these programs is about 16.4 ms.

Since the fuel injection amount is determined by the opening time of the injector 108, that is, the pulse width (time) of the voltage pulse applied to the injector 108, the fuel injection control signal is the same as the pulse width signal.

The gasoline control ECU 106 determines the most basic injection pulse based on the amount of intake air detected from the air flow meter 144 and the rotation speed of the engine 146 detected from the crank angle sensor (CAS).

ECCS uses a ternary catalyst (148), which converts harmful carbon monoxide (CO) or hydrocarbons (HC) into harmless carbon dioxide (CO ₂ ) or water (H ₂ O) and nitrates ( NOx) is reduced to nitrogen (N ₂ ) or oxygen (O ₂ ) to purify the air pollution three components at once. The purification rate of the three-way catalyst 148 must be precisely adjusted within a narrow range centering on the theoretical performance ratio to maximize the purification efficiency. Therefore, after the oxygen sensor 150 is mounted on the exhaust pipe through which the combustion gas is discharged, the oxygen concentration in the exhaust gas is measured and the signal is fed back to the gasoline control ECU 106 to correct the injection pulse. However, if the cooling water temperature is 70 ℃ or less for stability of operation, if the fuel cut correction during inertia driving is 0, if the air-fuel ratio correction is the maximum due to the rich mixing ratio (the high-load, high-speed range for adjusting the output-standard air-fuel ratio is rich). State), when the rich mixing ratio signal is continuously generated for more than 6.4 seconds from the oxygen sensor 150 and when the sparse mixing ratio signal is continuously generated for at least 10 seconds from the oxygen sensor 150, and the engine is rotated 50 times after starting. While the feedback control is stopped.

Correcting the fuel to the theoretical performance ratio by the feedback control of the oxygen sensor 150 is the basis of gasoline fuel injection control, but according to the engine condition, water temperature increase correction, start-up and post-start increase correction, post-idling increase correction, and mixing ratio Correction and fuel shut-off during inertial driving are performed.

When the gasoline control ECU 106 receives signals from various sensor signals and controls the injector to lengthen the fuel injection energization time, the oxygen sensor voltage is instructed to be high and the gasoline control ECU 106 determines that the air-fuel ratio is rich. By shortening the energization time sent to the injector 108, emissions of carbon monoxide and hydrocarbons are reduced. When the fuel injection energization time is shortened, the oxygen sensor voltage is instructed to be low, and at this time, the gasoline control ECU 106 determines that it is lean so that the energization time sent to the injector 108 is increased to control the theoretical air fuel ratio. That is, when the output voltage of the oxygen sensor 150 is 0.45V or more, the gasoline control ECU 106 determines that the air-fuel ratio is rich and shortens the air-fuel ratio by shortening the injection nozzle energization time. When the mixer supplied into the combustion chamber becomes thin, the voltage input from the oxygen sensor 150 to the gasoline control ECU 106 becomes a low voltage of 0.45V or less. At this time, the gasoline control ECU 106 determines that the current concentration of the mixer in the combustion chamber is lean so as to increase the air-fuel ratio by increasing the injection nozzle energization time.

As described above, since the energization time sent to the injector is controlled by the gasoline control ECU 106 by receiving signals from various sensors, when the duty solenoid valve 120 is controlled based on this signal, the ignition timing and fuel injection By matching the engine power, it is possible to solve the backfire problem, the exhaust gas problem and the fuel economy problem that occur most in the LPG / gasoline combined vehicle according to the prior art.

As a result of experiments while controlling the energization time of the injector to ms for various fuel injection methods using the fuel injection value of the LPG / gasoline combined vehicle according to the present invention structured as described above, no matter what fuel injection method, And satisfactory results were obtained at high speeds, and the emission of carbon monoxide, hydrocarbons and nitrides, which are the main causes of environmental pollution, was minimized. In particular, the exhaust gas at idle and mid-speed is close to the theoretical air-fuel ratio, so fuel economy was also the best.

10 to 12 show graphs showing engine fuel injection performance test results at 840 rpm, 1310 rpm and 4700 rpm in a combined LPG / gasoline vehicle according to the prior art; 13 to 15 show graphs showing engine fuel injection performance test results at 760 rpm, 860 rpm, and 1640 rpm in the LPG / gasoline combined vehicle according to the present invention.

The fuel injection performance test of FIGS. 10 to 15 was performed at the Korea Tune Up Research Group using a Bosch 560 engine tester manufactured by Germany. In FIGS. 10 to 15, the horizontal axis represents time and the vertical axis represents voltage.

As described above, the fuel injection amount is determined by the opening time of the injector 108, that is, the pulse width of the voltage pulse applied to the injector 108.

When the graphs of FIGS. 10 and 15 are compared with each other, in the range of 750 to 840 RPM corresponding to idle, the LPG / gasoline combined vehicle according to the prior art requires a large pulse signal because fuel correction is not performed accurately. While the fuel is injected too much, it can be seen that a large amount of hydrocarbons are generated due to the large amount of carbon monoxide, hydrocarbons, and nitrous oxides, as well as fuel cut function is not provided, especially LPG / gasoline combination according to the present invention Since the fuel is corrected correctly, the number of pulse signals is reduced, so that the fuel consumption is low and the amount of harmful emission gas is significantly reduced.

11 and 12, in the LPG / gasoline combined vehicle according to the prior art, the number of pulses remains almost the same even when the RPM is changed from 840 RPM to 1310 RPM and back to 4700 RPM. Therefore, the LPG / gasoline combined vehicle according to the prior art can be seen that various corrections for the fuel injection timing and the fuel injection amount are not accurately made for each control section.

Referring to FIG. 14, when an RPM change occurs from an idle state of 760 RPM to 860 RPM, initially, the number of pulses increases as the RPM changes in an idle duty waveform of 760 RPM. The fuel supply stops and finally switches back to the idle duty waveform. In addition, referring to Figure 15, when the RPM change from the idle idle 860 RPM to 1640 RPM, the number of pulses increases as the RPM changes in the idle duty waveform of the 860 RPM at first, the fuel supply increases and then fuel In the cutable section, the fuel supply stops and finally switches back to the idle duty waveform. Therefore, it can be seen that in the LPG / gasoline combined vehicle according to the present invention, various corrections for the fuel injection timing and the fuel injection amount are precisely performed for each control section.

According to the configuration as described above of the present invention, by using the power LPG control ECU in the LPG / gasoline combined vehicle, the power LPG control ECU receives the signal output from the gasoline control ECU to include the LPG fuel ignition timing and fuel injection amount Since various control signals are outputted, fuel compensation can be accurately performed for each control section according to the engine performance curve, so that the engine output can be improved, the fuel cut function can be effectively performed, the emission gas is reduced, and the ignition timing is precise. Control becomes possible, and fuel economy is improved.

While the present invention has been illustrated and described with reference to certain preferred embodiments, the invention is not limited thereto but may vary without departing from the spirit or scope of the invention as set forth in the claims below. It will be readily apparent to those skilled in the art that such modifications and variations can be made in the art.

Claims (7)

In an electronically controlled fuel injector of a LPG / gasoline combined vehicle, A gasoline control ECU for outputting various control signals including gasoline fuel ignition timing and fuel injection amount according to signals input from various switches and sensors provided to the vehicle; An injector for supplying a predetermined amount of gasoline fuel to a cylinder according to a fuel injection amount control signal output from the gasoline control ECU during a gasoline fuel use mode; A power LPG control ECU connected to an output side of the gasoline control ECU for receiving a signal output from the gasoline control ECU and outputting various control signals including LPG fuel ignition timing and fuel injection amount; And And a duty solenoid valve for supplying a predetermined amount of LPG fuel to the cylinder according to a fuel injection amount control signal output from the power LPG control ECU in the LPG fuel use mode. Device. The method of claim 1, The power LPG control ECU includes a microcomputer for accurately controlling the total amount of LPG fuel supplied to the cylinder by reading a fuel injection method according to the vehicle type according to a signal output from the gasoline control ECU; Accordingly, the power LPG control ECU can be shared with all vehicles adopting any one of the group injection method, the independent injection method, and the simultaneous injection method, and the LPG / gasoline combined vehicle. Fuel injector. The method of claim 1, The signal input to the gasoline control ECU is a throttle valve switch, start switch, air conditioner switch, neutral switch, intake temperature sensor, exhaust temperature sensor, coolant temperature sensor, battery voltage, oxygen sensor, vehicle speed sensor, air flow meter, crank angle sensor Electronically controlled fuel injector of the LPG / gasoline combined vehicle comprising a signal input from. In the electronically controlled fuel injection method of the LPG / gasoline combined vehicle, Outputting, from the gasoline engine control EUC, various control signals including gasoline fuel ignition timing and fuel injection amount according to signals input to the gasoline engine control ECU from various switches and sensors provided to the vehicle; Supplying a predetermined amount of gasoline fuel to a cylinder according to a fuel injection amount control signal output from the gasoline control ECU to the injector during the gasoline fuel use mode; Outputting various control signals including LPG fuel ignition timing and fuel injection amount by a power LPG control ECU connected to an output side of the gasoline control ECU and receiving a signal output from the gasoline control ECU; And Supplying a predetermined amount of LPG fuel to a cylinder according to a fuel injection amount control signal output from the power LPG control ECU to the duty solenoid valve during the LPG fuel use mode; and an electronically controlled LPG / gasoline combined vehicle. Fuel injection method. The method of claim 4, wherein Reading the fuel injection method according to the vehicle type by the microcomputer according to the signal output from the gasoline control ECU and always accurately controlling the total amount of the LPG fuel supplied to the cylinder; LPG / gasoline further comprising a Electronically controlled fuel injection method for a combined vehicle. The method according to claim 4 or 5, The power LPG control ECU is an electronically controlled fuel injection method for an LPG / gasoline combined vehicle, which can be shared by all vehicles employing any one of the group injection method, the independent injection method, and the simultaneous injection method. . The method of claim 4, wherein The signal input to the gasoline control ECU is a throttle valve switch, start switch, air conditioner switch, neutral switch, intake temperature sensor, exhaust temperature sensor, coolant temperature sensor, battery voltage, oxygen sensor, vehicle speed sensor, air flow meter, crank angle sensor Electronically controlled fuel injection method of a combined LPG / gasoline vehicle, characterized in that it comprises a signal input from.