JP3661705B2 - Fuel injection type two-cycle engine starting device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a starter for a fuel injection type two-cycle engine, and more particularly to a starter for a fuel injection type two-cycle engine that can maintain a proper air-fuel ratio at the time of restart and improve restartability.
[0002]
[Prior art]
The two-cycle engine generates power by repeating two strokes of the piston with one revolution of the crankshaft, and is mounted on motorcycles, outboard motors, and snowmobiles called snowmobiles. Has been.
[0003]
Such a fuel injection type two-cycle engine starting device is disclosed in, for example, Japanese Patent Laid-Open Nos. 3-172551 and 3-172552. Those described in these publications allow the restart to be easily performed in consideration of the correction coefficient value corresponding to the cranking time so that the fuel injection amount does not become rich during the restart.
[0004]
[Problems to be solved by the invention]
However, conventionally, in a two-cycle engine, when the engine is stopped by running in a completely warm-up state, and then restarted after the engine is stopped, that is, the cooling water temperature has decreased to some extent, the ambient temperature in the crankcase When the engine is still warm and still warming up, the amount of fuel injection based on the coolant temperature is increased more than necessary, and the air-fuel ratio becomes excessively rich, which makes it easy to misfire and difficult to restart. There was the inconvenience of becoming.
[0005]
In addition, the water temperature sensor and the engine temperature sensor may be installed at a location where the cooling water temperature and the crankcase temperature are the same, but on the layout, the water temperature sensor and the engine temperature sensor cannot be installed at the same location. The mounting position of the water temperature sensor is restricted, and over-riching of the air-fuel ratio cannot be avoided.
[0006]
[Means for Solving the Problems]
Accordingly, in order to eliminate the above-described disadvantages, the present invention provides a two-cycle engine mounted on a snow vehicle, in a fuel injection type two-cycle engine starting device for controlling a fuel injection amount at the time of starting. A water temperature sensor for detecting the coolant temperature of the engine is provided, and the engine temperature sensor for detecting the atmosphere temperature of the two-cycle engine is disposed in the vicinity of the flywheel magneto, and the fuel injection amount at the start is determined according to the coolant temperature In addition, there is provided a control means for obtaining a magnitude relationship between the cooling water temperature and the engine atmosphere temperature, and when the engine atmosphere temperature is higher than the cooling water temperature, a control means for reducing the fuel injection amount at the start-up is provided. And
[0007]
[Action]
According to the configuration of the present invention, in the two-cycle engine mounted on the snow vehicle, the fuel injection amount at the start is determined according to the coolant temperature, and the magnitude relationship between the coolant temperature and the engine atmosphere temperature is obtained. If the engine ambient temperature is higher than the coolant temperature, the fuel injection amount at start-up is corrected so that the 2-cycle engine is stopped after running in a fully warmed-up state, and then left unattended. When the atmospheric temperature is higher than the cooling water temperature, the control means accurately calculates the amount of fuel to be injected, so that over-riching is prevented, the air-fuel ratio is made appropriate, restartability is improved, The mounting position of the water temperature sensor is not restricted, and the degree of freedom of the mounting position of the water temperature sensor can be increased.
[0008]
【Example】
Embodiments of the present invention will be described in detail and specifically with reference to the drawings.
[0009]
1 to 9 show an embodiment of the present invention. 8 and 9, 2 is a snow vehicle, 4 is a steering ski, 6 is a hood, 8 is a two-cycle engine, 10 is a windshield, 12 is a handle, 14 is a seat, and 16 is a truck.
[0010]
The snow vehicle 2 is configured to reduce the contact pressure by reducing the weight, increase the output per unit weight, and to drive through fresh snow and deep snow. A two-cycle engine 8 that is easy to start is mounted.
[0011]
As shown in FIG. 1, the engine 8 includes a main body 18, a crankcase 20, a bottom 22, a head 24, a crankshaft 26, and a combustion chamber 28. In addition, an intake port 30, an exhaust port 32, and a cooling water passage 34 are formed in the main body 18. Further, a water pump 36 is attached to the main body 18. A water bypass pipe 38 is connected to the water pump 36. A water temperature sensor 40 for detecting the cooling water temperature is attached to the water bypass pipe 38. The head 24 is provided with a spark plug 42.
[0012]
A throttle body 46 having a throttle valve 44 is connected to the main body 18 on the intake port 30 side. A throttle position sensor 48 for detecting the opening state of the throttle valve 44 is communicated to the throttle valve 44. An air box 50 is provided on the upstream side of the throttle body 46. The air box 50 is provided with an intake air temperature sensor 52 for detecting the intake air temperature.
[0013]
A fuel injection valve 54 that injects fuel downstream of the throttle valve 44 is attached to the throttle body 46. Since the engine 8 has two cylinders, a fuel injection valve 54 is provided for each cylinder. One end side of a fuel supply passage 56 is connected to the fuel injection valve 54. The other end side of the fuel supply passage 56 is connected to, for example, a fuel pump 60 installed in the fuel tank 58. Here, when the fuel pump 60 is installed outside the fuel tank 58, the fuel pump 60 and the fuel filter 62 are sequentially disposed in the middle of the fuel supply passage 56 from the fuel tank 58 side as shown by the broken line in FIG. And intervene.
[0014]
In order to keep the fuel pressure to the fuel injection valve 54 constant, a fuel pressure adjustment valve 64 is provided in communication with the fuel injection valve 54, and the fuel pressure adjustment valve 64 is connected to the fuel tank 58. A return passage 66 is in communication.
[0015]
A flywheel magneto 68 is attached to the end of the crankshaft 26. In the vicinity of the flywheel magneto 68, a crank angle sensor 70 for detecting the crank position and the engine speed, and a cylinder discrimination sensor 72 for discriminating which cylinder comes after the top dead center (TDC). A non-contact type engine temperature sensor 74 that detects the temperature in the crankcase 20 that is the atmospheric temperature of the engine 8 is disposed.
[0016]
The flywheel magneto 68 is in communication with a CDI unit 76. The spark plug 42 is connected to the CDI unit 76 via an ignition coil 78.
[0017]
The fuel injection valve 54 is in communication with a control means (ECU) 82 via a dropping register 82. Therefore, the operation of the fuel injection valve 54 is controlled by the drive signal pulse from the control means 82.
[0018]
Further, the fuel pump 60 is communicated to the control means 82 via a fuel pump relay 84, and the water temperature sensor 40, the throttle position sensor 48, the intake air temperature sensor 52, the crank angle sensor 70, and the cylinder discrimination sensor 72 are A non-contact type engine temperature sensor 74, a CDI unit 76, and an EFI relay 86 are in communication.
[0019]
The EFI relay 86 is connected to an ignition switch 88, a first fusible link 90, and an EFI relay circuit (ignition off circuit) 92 connected to the CDI unit 76.
[0020]
The first fusible relay 90 is in communication with a battery 94. The battery 94 is in communication with a second phaseable link 96 connected to the fuel pump relay 84.
[0021]
Further, a DCRR circuit 98 connected to the flywheel magneto 68 is connected to the battery 94. A charge lamp 100 is communicated to the DCRR circuit 98.
[0022]
An AC regulator 102 and a headlamp 104 are connected to the flywheel magneto 68.
[0023]
Further, the control means 82 incorporates an atmospheric pressure sensor 106.
[0024]
The control means 82 receives detection signals from various sensors and controls the fuel injection amount at start-up according to the coolant temperature (TW) and the temperature (TC) in the crankcase 20 that is the engine atmosphere temperature. It is.
[0025]
For this reason, the program of the control means 82 includes a map of the single injection amount (TAONIJ) corresponding to the cooling water temperature (TW) as shown in FIG. 4 and a cooling water temperature (TW) as shown in FIG. Corresponding map of starting basic injection amount (TiLNTK), map of rotation correction coefficient (KLN) according to engine speed as shown in FIG. 6, and time correction corresponding to cranking time as shown in FIG. A coefficient (KLT) map is incorporated.
[0026]
Next, the operation of this embodiment will be described based on the block diagram of FIG.
[0027]
When the detection signal from the crank angle sensor 70 is input to the control means 82, the CDI pulse, crank position and engine speed are calculated (202), and the cylinder discrimination pulse and cylinder discrimination are set ( 204).
[0028]
When the detection signal from the throttle position sensor 48 is input, the basic fuel injection amount is set (206) from the basic fuel injection amount map (208).
[0029]
When detection signals from the water temperature sensor 40, the atmospheric pressure sensor 106, and the intake air temperature sensor 52 are input, an increase correction coefficient is set in each sensor (210), and a corrected fuel injection amount is calculated (212). .
[0030]
When the voltage state of the battery 94 is input, the voltage correction increase amount of the fuel injection valve 54 is set (214), and the first fuel injection amount (NO.1) is calculated (216), and the second A fuel injection amount (NO. 2) is calculated (218). Here, there is a relationship of first fuel injection amount> second fuel injection amount. The corrected fuel injection amount (212) described above is added to the first and second fuel injection amounts, and the first fuel injection amount or the second fuel injection amount is compared (220).
[0031]
When the detection signal from the engine temperature sensor 74 is input, it is determined whether or not the relationship between the coolant temperature (TW) and the ambient temperature of the engine 8, that is, the temperature (TC) in the crankcase 20, satisfies TW ≧ TC (222). Further, it is determined whether or not TW <TC (224).
[0032]
The determination by comparison (222) when TW ≧ TC is sent to the comparison (220) of the first fuel injection amount or the second fuel injection amount described above.
[0033]
Further, the determination based on the comparison (224) when TW <TC is sent to the calculation of the first corrected fuel injection amount (226).
[0034]
The CDI pulse, the crank position, and the engine speed (202) are added to the basic fuel injection amount setting (206) and the engine speed setting (228). Further, the setting (228) of the engine speed takes into account the comparison (220) of the first fuel injection amount or the second fuel injection amount and the first corrected fuel injection amount (226).
[0035]
If the engine speed is set (228), the total fuel injection amount is set (230) according to the set engine speed, the CDI pulse, the crank position, and the engine speed (202). Then, the cylinder discrimination pulse and the cylinder discrimination setting (204) are added to set the drive of the fuel injection valve (232), and the first cylinder fuel injection valve (134) and the second cylinder fuel injection valve 54 are set. (136) are activated.
[0036]
Next, fuel injection amount setting control will be described based on the flowchart of FIG.
[0037]
When the program of the control means 82 is started (step 302), first, it is determined whether or not it is started, that is, whether or not the ignition switch 78 is on (step 304).
[0038]
If YES in step 304, it is determined whether or not TW ≧ TC or TW <TC based on the coolant temperature (TW) and the engine atmosphere temperature (TC) (step 306).
[0039]
If TW ≧ TC in step 306, the injection quantity (TAONIJ) is determined from the map of FIG. 4 corresponding to the coolant temperature (TW) (step 308).
[0040]
Then, the starting basic injection amount (TiLNTK) is determined from the map of FIG. 5 according to the coolant temperature (TW) (step 310), and the rotation correction is made from the map of FIG. 6 according to the engine speed (N). A coefficient (KLN) is determined (step 312), and a time correction coefficient (KLT) is determined from the map of FIG. 7 according to the cranking time (T) (step 314).
[0041]
Then, the one-shot injection amount (TAONIJ) + starting injection pulse width (TiLN ₁ ) is calculated (step 316). Here, the starting injection pulse width (TiLN ₁ ) = starting basic pulse width (TiLNTK) × rotation correction coefficient (KLN) × time correction coefficient (KLT).
[0042]
On the other hand, if TW <TC in step 306, the injection quantity (TAONIJ) is determined from the map of FIG. 4 corresponding to the cooling water temperature (TW) and the injection quantity (TAONIJ). X A weight reduction correction coefficient (KE) is calculated (step 318).
[0043]
Then, the starting basic injection amount (TiLNTK) is determined from the map of FIG. 5 according to the coolant temperature (TW), and the starting basic injection amount (TiLNTK) × the reduction correction coefficient (KE) is calculated (step 320). In addition, a rotation correction coefficient (KLN) is determined from the map of FIG. 6 according to the engine speed (N), and a rotation correction coefficient (KLN) × a reduction correction coefficient (KE) is calculated (step 322). Further, a time correction coefficient (KLT) is determined from the map of FIG. 7 according to the cranking time (T) (step 324).
[0044]
Then, the single injection amount (TAONIJ) × the reduction amount correction coefficient (KE) + the starting injection pulse width (TiLN ₂ ) is calculated (step 326). Here, starting injection pulse width (TiLN ₂ ) = starting basic pulse width (TiLNTK) × reduction correction coefficient (KE) × rotation correction coefficient (KLN) × reduction correction coefficient (KE) × time correction coefficient (KLT) is there.
[0045]
On the other hand, if the answer is NO in step 304, a normal total injection amount (Ti) is calculated (step 328).
[0046]
When the calculation of each injection amount is completed, the process is returned (step 330).
[0047]
As a result, the engine ambient temperature is detected by the engine water temperature sensor 74 near the flywheel magneto 68 in a non-contact manner, so that the engine ambient temperature, that is, the temperature in the crankcase 20 is accurately detected. After running in a completely warm-up state, after stopping the engine 8 and leaving it to stand, the fuel injection amount is appropriately reduced when starting when the crankcase 20 temperature is still higher than the coolant temperature. Thus, it is possible to prevent the air-fuel ratio from being excessively rich and facilitate the restart.
[0048]
Further, since the engine temperature sensor 74 detects the engine atmosphere temperature, the degree of freedom of the mounting position of the water temperature sensor 40 is increased.
[0049]
【The invention's effect】
As is apparent from the above detailed description, according to the present invention, in a two-cycle engine mounted on a snow vehicle, a water temperature sensor for detecting the coolant temperature of the two-cycle engine is provided, and the ambient temperature of the two-cycle engine is detected. disposed engine temperature sensor in the vicinity flywheel magneto, and determines a fuel injection amount at the time of starting in accordance with the coolant temperature, determine the magnitude relation between the cooling water temperature and the engine ambient temperature, the engine ambient temperature cooling water When the temperature is higher than the temperature, the control means for correcting the decrease in the fuel injection amount at start-up is provided, so that the two-cycle engine is stopped after running with complete warm-up, When the ambient temperature is higher than the cooling water temperature, the air-fuel ratio is prevented from becoming excessively rich, the air-fuel ratio is maintained appropriately, and restartability is improved. Moreover, the mounting position of the water temperature sensor is not restricted, and the degree of freedom of the mounting position of the water temperature sensor can be increased.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a starter.
FIG. 2 is a block diagram of fuel injection control.
FIG. 3 is a flowchart for obtaining a fuel injection amount.
FIG. 4 is a relationship diagram of a single injection amount corresponding to a cooling water temperature.
FIG. 5 is a relationship diagram of a starting basic injection amount corresponding to a coolant temperature.
FIG. 6 is a relationship diagram of a rotation correction coefficient corresponding to the engine speed.
FIG. 7 is a relationship diagram of time correction coefficients corresponding to cranking time.
FIG. 8 is a side view showing an engine part of a snow vehicle.
FIG. 9 is a side view of a snow vehicle.
[Explanation of symbols]
2 Snowmobile 8 Engine 40 Water temperature sensor 54 Fuel injection valve 68 Flywheel magneto 74 Engine temperature sensor 82 Control means

Claims (1)

A two-cycle engine mounted on a snow vehicle, wherein the starter of the fuel-injection type two-cycle engine controls a fuel injection amount at the time of starting, and a water temperature sensor for detecting a cooling water temperature of the two-cycle engine is provided, An engine temperature sensor that detects the ambient temperature of the two-cycle engine is arranged near the flywheel magneto , determines the fuel injection amount at start-up according to the coolant temperature, and the magnitude relationship between the coolant temperature and the engine ambient temperature When the engine ambient temperature is higher than the cooling water temperature , the fuel injection type two-cycle engine starting device is provided with a control means for reducing the fuel injection amount at the time of starting.

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