JPH06167231A - Alternate fuel controller of fuel injection type two-cycle engine - Google Patents

Abstract

PURPOSE:To make the structure of an alternate fuel controller adoptable without using sensor, etc., for detecting the characteristic of fuel by varying a fuel set condition to such a condition which matches that of the fuel in use in response to ON-operation of respective fuel command switches when the fuel set condition of an engine is different from that of the fuel in use. CONSTITUTION:A plural number of injectors 32 for injecting fuel per cylinder are arranged in the throttle body 24 of an engine 8. Those injectors 32 are connected to a fuel tank 36 via a fuel supply passage 34 provided with a fuel pump 40. At least fuel designation changeover switch 74 for making its switching operation required to select the kind of fuel to be used is connected to the control unit 44. In this case, a plural number of the fuel designation switches 76, 78 for designating the kind of fuel are connected to the control unit 44. As a result, the fuel setting condition is changed so that it may match the fuel designated by the respective fuel designation switches 76, 78 when the fuel setting condition of the engine 8 is different from that of the fuel in use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternative fuel control system for a fuel injection type two-cycle engine, and more particularly, to a fuel injection type two which is provided with an injector for injecting fuel and which performs a switching operation to select and use a fuel type. The present invention relates to an alternative fuel control device for a cycle engine.

[0002]

2. Description of the Related Art A two-cycle engine is an engine in which a piston moves two strokes by one rotation of a crankshaft, and is distinguished from a four-cycle engine. Outboard motor,
And it is installed in a snowmobile called a snowmobile.

[0003]

In the conventional alternative fuel control system for a fuel injection type two-cycle engine, the specific gravity of the fuel in the fuel tank is detected by the methanol sensor, and this detection signal is sent to the alternative fuel control system. Feedback was used to optimize. However, since the methanol sensor is compatible with ethanol, the cost of the sensor increases, which is economically disadvantageous.

[0004]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention is provided with an injector for injecting fuel and a fuel designation changeover switch for changing over to select and use the type of fuel. Fuel injection type 2
In the cycle engine, a fuel designating switch for designating fuel is provided, and if the preset fuel setting state of the two-cycle engine is different from the fuel used, the fuel designating switch should be turned on to match the fuel used. It is characterized in that a control unit for changing the fuel setting state is provided.

[0005]

According to the invention as described above, when the preset fuel setting state of the two-cycle engine is different from the fuel to be used, the control unit should match the fuel to be used by turning on the fuel designation switch. The fuel setting status is being changed.

[0006]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 6 show an embodiment of the present invention. 3 (a) and 3 (b), 2 is a snowmobile, 4
Is a ski for steering, 6 is a hood, 8 is an engine, 10 is a windshield, 12 is a steering wheel, 14 is a seat, 1
6 is a truck.

[0008] The snow vehicle 2 is constructed so that the snow contact pressure can be reduced by reducing the weight thereof, the output per unit weight can be increased, and even fresh snow and deep snow can be run through, and the snow vehicle 2 is small and lightweight. A two-cycle engine 8 that is easy to start in cold weather is installed.

Further, the snowmobile 2 is, as shown in FIG.
An intake passage 20 communicating with the combustion chamber 18 of the engine 8 is provided, and the intake passage 20 is formed in a throttle body 24 connecting an air box 22 on the upstream side.

Further, an intake air temperature sensor 26 for detecting an intake air temperature is provided in the air box 22, a throttle valve 28 is provided in the throttle body 24, and
A throttle position sensor 30 for detecting the throttle opening of the throttle valve 28 is provided.

A plurality of injectors 32 for injecting fuel into each cylinder (not shown) are provided above the throttle body 24, and a fuel tank 36 is connected to the injectors 32 through a fuel supply passage 34. When provided, the fuel return passage 38 is also connected.

In the middle of the fuel supply passage 34,
It is also possible to interpose a fuel pump 40 that pumps the fuel under pressure, and the installation position of this fuel pump 40 may be the broken line portion in FIG. 4.

In the middle of the fuel return passage 38, the surplus fuel pressure is adjusted so that the fuel injection pressure is adjusted to a predetermined value.
A pressure regulator 42 that escapes to the side is provided.

A control unit 44 is provided on the snowmobile 2. The control unit 44 includes a crankshaft 46 of the engine 8.
Crank angle sensor 5 for detecting crank position and engine speed by a flywheel magneto 48 mounted on
0, a cylinder discriminating sensor 52 for discriminating a cylinder next to the top dead center (TDC), and the throttle position sensor 3
0 and the water pump 54 arranged in the engine 8
For example, various sensors such as a cooling water temperature sensor 58 provided in the water bypass passage 56 for detecting the cooling water temperature, an atmospheric pressure sensor 60 built in the control unit 44 and detecting the atmospheric pressure, and the intake air temperature sensor 26 are provided. In addition to being connected, the battery 62 and the ignition switch 64 for detecting the supply of operating power and the power supply voltage are also connected.

Further, as shown in FIG.
A CDI unit 66, an AC regulator 68, a headlamp 70, a warning bell lamp 72, a fuel designation changeover switch 74, and first and second fuel designation switches 76 and 78 are connected.

When the preset fuel setting state is different from the fuel used, the control unit 44 matches the fuel used by turning on the first and second fuel designation switches 76 and 78. Therefore, the fuel injection amount of the injector 32 in the fuel setting state is changed.

Reference numeral 80 is an ignition coil and 82
Is a spark plug, 84 is an EFI relay for an ignition OFF circuit,
86 is a DC RR, 88 is a dropping register, 90
Is a fuel pump relay, 92 is an EFI relay, 94 is a fusible link, and 96 is a charge lamp.

Next, the function of the control unit 44 will be described with reference to FIG.

When a detection signal is input to the control unit 44 from the crank angle sensor 50 and the cylinder discrimination sensor 52, the CDI pulse crank position and the engine speed are calculated (100) from the detection signal, and the cylinder discrimination pulse is calculated. The cylinder discrimination setting (102) is performed.

Then, from the calculation of the CDI pulse crank position and the engine speed (100), the total injection amount is set (1
04) is performed, and the drive setting (106) of the injector 32 is performed by the total injection amount setting process (104) and the cylinder determination setting process (102).
The drive signal is output to.

Further, the throttle position sensor 3
The basic fuel injection amount is set (110) by the detection signal from 0, the CDI pulse crank position, the engine speed calculation (100), and the basic fuel injection amount map (108), and the engine speed is set (112). The process is later informed of the total injection amount setting process (104).

The cooling water temperature sensor 58 and the atmospheric pressure sensor 60,
Then, the increase correction coefficient of each sensor is set (114) by the detection signal of each intake air temperature sensor 26.

The corrected fuel injection amount is calculated (116) by the output signal from the increase correction coefficient setting process (114) and the output signal from the basic fuel injection amount setting process (110) in each sensor.

When the detection signal of the power source voltage of the battery 62 is input, the voltage correction amount increase (118) of the injector 32 is performed, and the correction fuel injection amount calculation process (11) is performed.
6) and the output signal from the voltage correction increase processing (118). 1> NO. No. 2 having a relationship of 2. Calculation of fuel injection amount (tiln) (120) and NO. 2 Calculation of fuel injection amount (TE) (122) is performed.

When the detection signal from the fuel designation changeover switch 74 is input, the alternative specification fuel setting (12
4) and normal specification fuel setting (126),
After selecting the normal specification fuel setting (126), NO. Calculation of 1 fuel injection amount (tiln) (122) and NO. No. 2 from the calculation (TE) (124) of the fuel injection amount. 1 or NO. The two fuel injection amounts are compared (128) and output to the above-described engine speed setting (112).

After selecting the alternative fuel setting (124), the NO. 1, NO. 2 Calculation of corrected fuel injection amount (13
0) and set the engine speed as described above (112)
Output to.

The alternative specification fuel setting (124) can be specified by turning on the first fuel specifying switch 76, and the normal specification fuel setting (126) can be specified by turning on the second fuel specifying switch 78. be able to.

If the fuel setting state preset by the fuel designation changeover switch 74 is different from the fuel used, the control unit 44 uses the fuel to be used by turning on the first and second fuel designation switches. The fuel setting state is changed to meet the above condition.

Next, the operation will be described with reference to the start control flowcharts of the two-cycle engine shown in FIGS.

When the program for fuel injection control starts, it is judged whether it is a normal specification or an alternative specification (200). When this judgment (200) is a normal specification, the normal total injection amount (ti) and the fuel are injected. The injection amount (tiin) is calculated (202) and returned (204).

When the determination (200) is the alternative specification, the normal total injection amount (ti) and the fuel injection amount (tii)
n) is calculated by multiplying it by a uniform ratio (206), and the process is returned (204).

Further, the user selects the fuel designation changeover switch 74.
If the user forgets to do so, as shown in FIG. 2, it is judged whether the first fuel designation switch 76 is ON (300),
When the first fuel designation switch 76 is turned on, calculation is performed by multiplying the normal total injection amount (ti) and the fuel injection amount (tiin) by a uniform ratio (302), and the return (30).
4) Yes. At this time, the alarm bell lamp 72 for notification is turned on to notify the user of the state of fuel used.

Furthermore, when the first fuel designating switch 76 is off, it is judged whether or not the second fuel designating switch 78 is on (306), and the second fuel designating switch 78 is on. In the case, the normal total injection amount (ti)
Then, the fuel injection amount (tiin) is calculated (306) and returned (304).

Next, referring to FIG. 6, after setting the total injection amount (tiln) at startup (400), the NO.
1 Calculation of fuel injection amount (402) and setting of correction coefficient (40
4) is performed and is output to drive (406) the injector 32.

As a result, an alternative fuel control device can be constructed without using sensors for detecting the property of fuel,
Manufacturing cost can be reduced, which is economically advantageous.

When the fuel setting state preset by the control unit 44 is different from the fuel used, the fuel setting state is set to match the fuel used by turning on the first and second fuel designation switches 76 and 78. By being able to change, it is possible to reliably adapt to the fuel used and the fuel setting state, which is practically advantageous.

Further, since the alarm lamp 72 is provided, the fuel used can be reliably notified to the user, which is practically advantageous.

The present invention is not limited to the above-mentioned embodiment, but various application modifications are possible.

For example, in the embodiment of the present invention, when the user forgets the fuel designation changeover switch 74, the control is performed by the flow chart shown in FIG. 2, but the control is performed by the flow chart shown in FIG. It can also be configured appropriately.

According to the flow chart of FIG. 7, when the fuel injection control program starts, the engine 8
Is determined (500), and if this determination (500) is YES, the normal total injection amount (ti) and the fuel injection amount (tiin) are multiplied by a uniform ratio. The calculation is performed (502) and the process is returned (504).

If the determination (500) is NO, the switch positions of the first and second fuel designation switches 76 and 78 are determined (406). If the switch position is the first fuel designation switch 76, A calculation is performed by multiplying the normal total injection amount (ti) and the fuel injection amount (tiin) by a uniform ratio (502), and the process returns (504).

When the switch position is the second fuel designation switch 78 in the judgment (406), the normal total injection amount (ti) and the fuel injection amount (tiin) are calculated (508), and the return (504) is performed. )is doing.

Even if you forget to specify the fuel,
It is possible to reliably shift to the alternative fuel side before starting, it is possible to prevent seizure from occurring, and it is possible to secure engine protection and optimum operating conditions.

[0044]

As described above in detail, according to the present invention, the fuel designation switch for designating the fuel is provided, and when the preset fuel setting state of the two-cycle engine is different from the fuel used, the fuel designation switch is used. Since a control unit that changes the fuel setting state to match the fuel used by turning on the fuel is installed, an alternative fuel control device can be configured without using sensors that sense the property of the fuel, and the manufacturing cost can be reduced. Therefore, it is economically advantageous. When the fuel setting state preset by the control unit is different from the fuel used, the fuel setting state is changed to match the fuel used by turning on the fuel designation switch. It can be reliably adapted to the fuel setting state, which is practically advantageous.

[Brief description of drawings]

FIG. 1 is a flowchart for alternative fuel control of a two-cycle engine showing an embodiment of the present invention.

FIG. 2 is a flowchart for alternative fuel control.

FIG. 3 (a) is a right side view of the snowmobile in a partially cutaway state. (B) It is a right view of a snowy vehicle.

FIG. 4 is a schematic diagram of an alternative fuel control system for a two-cycle engine.

FIG. 5 is a block diagram showing an operation of a control unit.

FIG. 6 is a flow chart showing setting of a total injection amount at startup.

FIG. 7 is a flow chart for alternative fuel control of a two-cycle engine showing another embodiment of the present invention.

[Explanation of symbols]

 2 Snowmobiles 4 Steering skis 6 Hood 8 Engine 10 Windshield 12 Handle 14 Seat 16 Truck 20 Intake passage 24 Throttle body 26 Intake temperature sensor 28 Throttle valve 30 Throttle position sensor 32 Injector 36 Fuel tank 40 Fuel pump 44 Control unit 50 Crank Angle sensor 52 Cylinder discrimination sensor 54 Water pump 58 Cooling water temperature sensor 60 Atmospheric pressure sensor 62 Battery 64 Ignition switch 72 Warning bell lamp for notification

[Procedure amendment]

[Submission date] February 10, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 6]

[Figure 4]

[Figure 5]

[Figure 7]

Claims (1)

[Claims] 1. A fuel injection type two-cycle engine having an injector for injecting fuel and a fuel specification changeover switch for selecting and selecting a type of fuel for use. When the preset fuel setting state of the two-cycle engine is different from the fuel used, a control unit is provided for changing the fuel setting state to match the fuel used by turning on the fuel designating switch. An alternative fuel control device for a characteristic two-cycle fuel injection engine.