JP4320655B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine having a function of detecting a gear position of a transmission.

  For example, in a two-wheeled vehicle, a gear position of a transmission is detected by a gear position sensor, and engine control such as vehicle speed limitation is performed using an output signal of the gear position sensor and an engine speed as parameters.

  In the above configuration, if the gear position sensor fails, the gear position is naturally erroneously detected, so that appropriate engine control according to the gear position cannot be performed. Further, in a state where the gear position is being switched (that is, during shifting), the output of the gear position sensor does not detect the gear position, so that engine control according to the gear position becomes impossible. That is, every time the gear position is switched, the control using the gear position as a parameter is interrupted during the gear shift, and the control characteristics during the gear shift are poor.

An object of the present invention detects the during shifting, it is to improve the control characteristics during the shift.

In order to achieve the object of the present invention, in claim 1, when it is determined that the transmission is shifting based on the output signal of the gear position detecting means and the light on / off signal of the neutral lamp, the gear immediately before that is determined. The correction coefficient for the fuel injection amount during the shift or the correction coefficient for the ignition timing during the shift is set using only the position and the rotational speed of the internal combustion engine. In this way, the correction coefficient for the fuel injection amount or the correction coefficient for the ignition timing can be set appropriately even during the shift, and the control characteristics during the shift are improved.

  Hereinafter, an embodiment in which the present invention is applied to a motorcycle will be described with reference to the drawings. An intake manifold 12 is connected to the intake port 10 of each cylinder of the engine 11 which is an internal combustion engine, and an air box 13 is connected to the upstream side of the intake manifold 12 of each cylinder, and is sucked into the air box 13. Air is sucked into the intake manifold 12 of each cylinder. An air cleaner (not shown) is mounted in the air box 13, and an intake air temperature sensor 14 for detecting the intake air temperature is attached to the air box 13. A throttle valve 15 is attached in the middle of the intake manifold 12 of each cylinder, and an opening degree (throttle opening degree) of the throttle valve 15 is detected by a throttle opening degree sensor 16. Further, an intake pressure sensor 17 for detecting intake pressure is provided on the downstream side of the throttle valve 15 in the intake manifold 12, and a fuel injection valve 18 is attached in the vicinity of the intake port 10 of each cylinder.

  On the other hand, the fuel pumped up from the fuel tank 19 by the fuel pump 20 is sent to the fuel pipe 21 → the fuel filter 22 → the fuel pipe 23 → the delivery pipe 24, and is distributed to the fuel injection valve 18 of each cylinder. Excess fuel in the delivery pipe 24 is returned to the fuel tank 19 through a path of the pressure regulator 25 → the return pipe 26. The pressure regulator 25 adjusts the fuel pressure in the delivery pipe 24 so that the differential pressure between the fuel pressure in the delivery pipe 24 and the intake pressure is constant.

  An ignition plug 27 is attached to the cylinder head of the engine 11 for each cylinder, and a high voltage generated on the secondary side of the ignition coil 28 at each ignition timing is applied to the ignition plug 27 of each cylinder and ignited. The engine 11 is provided with an engine speed sensor 29 (rotation speed detecting means) for detecting the engine speed, a cylinder discrimination sensor 30 for discriminating a specific cylinder, and a water temperature sensor 31 for detecting a cooling water temperature. . An atmospheric pressure sensor 32 for detecting atmospheric pressure is attached to a predetermined position of the vehicle body.

  Further, a gear position sensor 33 (gear position detecting means) for detecting a gear position of a transmission (not shown) for transmitting the output of the engine 11 to driving wheels is provided, and a neutral lamp 34 for displaying the neutral position is further provided. Is provided. An output signal of the gear position sensor 33 and an ON / OFF signal (lighting / extinguishing signal) of the neutral lamp 34 are input to the engine control circuit 35.

  Next, the circuit configuration of the gear position sensor 33 and the neutral lamp 34 will be described with reference to FIG. The gear position sensor 33 is constituted by a rotary switch having a rotary contact 36 connected to the ground terminal, and the rotary contact 36 rotates in conjunction with the speed change operation of the transmission. On the rotation locus of the rotary contact 36, for example, five fixed contacts S1 to S5 for gear position detection (in the case of five-speed shift) and a fixed contact Sn for neutral position detection are arranged. Resistors R1 to R5 having different resistance values are connected to the fixed contacts S1 to S5 for detecting the gear position, and these resistors R1 to R5 are connected to an A / D conversion circuit 37 in the engine control circuit 35 via a signal line L1. It is connected to the. The signal line L1 is connected to a DC power source Vcc (for example, 5V) via a resistor 38.

  In this case, when the rotary contact 36 comes into contact with the gear position detection fixed contact Si (i = 1 to 5), the resistor Ri (i = 1 to 5) and the resistor 38 cause the DC power supply voltage Vcc. Is divided, the divided voltage is taken into the A / D conversion circuit 37 in the engine control circuit 35, and the gear position is detected by the divided voltage. Further, when the speed is being changed, the rotary contact 36 is not in contact with any of the fixed contacts Si (i = 1 to 5) (all the fixed contacts Si are in an open state). In this state, the potential of the signal line L1 taken into the A / D conversion circuit 37 in the engine control circuit 35 is pulled up to the DC power supply voltage Vcc by the resistor 38, thereby detecting that the speed is being changed.

  On the other hand, the neutral contact Sn for detecting the neutral position is connected to one terminal of the neutral lamp 34, and the other terminal of the neutral lamp 34 is connected to the battery terminal (+ B). Further, the neutral contact Sn for detecting the neutral position (one terminal of the neutral lamp 34) is connected to an A / D conversion circuit 37 in the engine control circuit 35 through a signal line L2, and will be described later through this signal line L2. The neutral lamp 34 is turned on / off (ON / OFF signal). In the middle of the signal line L2, a diode 39 is connected with the cathode facing the neutral lamp 34, and the signal line L2 on the anode side of the diode 39 is connected to the DC power source Vcc via a resistor 40. The capacitor 41 is connected to the ground terminal. As a result, the potential of the signal line L2 taken into the A / D conversion circuit 37 in the engine control circuit 35 becomes the charge voltage of the capacitor 41, and this is read as a turn-on / off signal of the neutral lamp 34.

  In this case, in a state where the rotary contact 36 is away from the neutral position detecting fixed contact Sn, the neutral lamp 34 is OFF (extinguished). In this state, since the charging voltage of the capacitor 41 is maintained at the DC power supply voltage Vcc, the potential of the signal line L2 (charging voltage of the capacitor 41) taken into the A / D conversion circuit 37 in the engine control circuit 35 is high level. Thus, it is detected that the gear position is not the neutral position. Thereafter, when the rotary contact 36 comes into contact with the fixed contact Sn for detecting the neutral position, the neutral lamp 34 is turned on (lighted). In this state, since the charge of the capacitor 41 is discharged to the ground terminal side via the diode 39, the potential of the signal line L2 (charge voltage of the capacitor 41) taken into the A / D conversion circuit 37 in the engine control circuit 35 is discharged. ) Becomes a low level, and the neutral position is detected.

The engine control circuit 35 is mainly composed of a microcomputer, and various programs for engine control and the programs shown in FIGS. 3 to 4 are stored in a built-in ROM 45 (storage medium). The engine control circuit 35 executes various programs for engine control, and thereby controls various sensors such as a throttle opening sensor 16, an intake pressure sensor 17, an engine speed sensor 29, a cylinder discrimination sensor 30, and a water temperature sensor 31. The fuel injection control and the ignition control are performed by reading the output signal, and the program of FIGS. 3 to 4 is executed to read the output signal of the gear position sensor 33 and the on / off signal of the neutral lamp 34 to determine the gear position. Abnormal detection of the gear position sensor 33, detection during shifting, calculation of a ram pressure correction coefficient, and vehicle speed limitation are performed. The processing contents of the programs in FIGS. 3 to 4 will be described below.

[Gear position detection]
The gear position detection program of FIG. 3 is repeatedly executed every time the main program for engine control is started (for example, every 4 ms). When this program is started, first, at step 101, it is determined whether or not the signal of the neutral lamp 34 is ON (lighted). If it is ON, the routine proceeds to step 109, where the output signal GP of the gear position sensor 33 is output. Is compared with a predetermined determination value β (a voltage value slightly lower than the normal value of GP at the neutral time). If GP <β, it is determined that the gear position sensor 33 is abnormal, and the routine proceeds to step 111 where the gear position sensor abnormality flag XGPFL is set to “1” meaning abnormality. That is, at neutral, if the gear position sensor 33 is normal, the potential of the output signal GP of the gear position sensor 33 is at a high level, but the signal line L1 and the fixed contact Si for detecting the gear position (i = 1 to 5). If any one of them is short-circuited to the ground side, the potential of the output signal GP of the gear position sensor 33 decreases. Accordingly, an abnormality such as a short circuit of the gear position sensor 33 is detected by detecting a decrease in the potential of the output signal GP of the gear position sensor 33.

  If it is determined in step 109 that GP ≧ β, the gear position sensor 33 is determined to be normal, and the process proceeds to step 111 to determine neutral.

  On the other hand, if it is determined in step 101 described above that the signal of the neutral lamp 34 is OFF (extinguished), the process proceeds to step 102 where the output signal GP of the gear position sensor 33 is set to a predetermined determination value α (GP during shifting) Voltage value slightly higher than the normal value). If GP ≧ α, it is determined that the gear position sensor 33 is abnormal such as a short circuit, and the process proceeds to step 111, where the gear position sensor abnormality flag XGPFL is set to “1” meaning abnormality. That is, since the output signal GP of the gear position sensor 33 (the potential of the signal line L1) becomes the highest voltage during the shift (when the gear position detection fixed contact Si is opened), the output signal GP of the gear position sensor 33 and An abnormality such as a short circuit of the gear position sensor 33 is detected by setting the determination value α to be compared to a voltage value that is slightly higher than the normal value of the GP during the shift.

  If it is determined in step 102 that GP <α, the process proceeds to step 103, and the output signal GP of the gear position sensor 33 is set to a predetermined determination value β (a voltage value slightly lower than the normal value of GP during a shift). Compare with If GP> β, either the gear is being changed or the gear position sensor 33 is abnormal. In this case, the routine proceeds to step 104 where the shifting determination flag XGPCH is temporarily set to “1” meaning that shifting is in progress, and in the next step 105, whether shifting is in progress or the gear position sensor 33 is abnormal. Determine as follows. That is, since the vehicle is in a decelerating state during a shift, the duration of the decelerating state is compared with a predetermined time γ (a time slightly longer than the time required for the shifting operation), and if the duration of the decelerating state is shorter than the predetermined time γ, It is determined that a shift is in progress, and a shift determination flag XGPCH = 1 (during a shift) is maintained.

  On the other hand, if the duration time of the deceleration state exceeds the predetermined time γ, it is determined that the gear position sensor 33 is abnormal, the process proceeds to step 106, and the gear position sensor abnormal flag XGPFL is set to “1” meaning abnormal. Then, the shift determination flag XGPCH is reset to XGPCH = 0 (not being shifted).

If it is determined in step 103 described above that GP ≦ β, the gear position sensor 33 is not normal and the gear position sensor 33 is normal. In this case, the routine proceeds to step 107, where the gear position sensor abnormality flag XGPFL is set to “0” meaning normal, and the shifting determination flag XGPCH is set to “0” meaning that shifting is not in progress. Thereafter, in step 108, the gear position is determined from the voltage value of the output signal GP of the gear position sensor 33.

The processing of the above steps 101 to 111 corresponds to the shifting determining means in the claims .

  In determining whether the gear is being changed, the ON / OFF signal of the clutch may be taken into consideration, and the fact that the clutch is OFF may be added as one determination condition for whether the gear is being changed. In this way, it is possible to further improve the determination accuracy during the shift.

[Calculation of ram pressure correction coefficient]
The ram pressure correction coefficient calculation program in FIG. 4 serves as correction means in the claims and is repeatedly executed every time the main program for engine control is started (for example, every 4 ms). When this program is started, first, at step 201, it is determined whether or not the gear position sensor abnormality flag XGPFL = 1 (abnormal). If XGPFL = 1, the routine proceeds to step 202 where ignition cut or fuel cut is performed. This limits the maximum engine speed to a speed where ram pressure is not applied. Here, the ram pressure refers to the intake pressure that rises above the atmospheric pressure due to the filling effect of the air flowing into the air box 13 by the traveling wind. Then, in the next step 203, the ram pressure correction coefficient FRAM is set to 1.0 so that the correction by the ram pressure is not performed when the gear position sensor 33 is abnormal.

  If it is determined in step 201 that the gear position sensor abnormality flag XGPFL = 0 (normal), the process proceeds to step 204, in which it is determined whether a shift determination flag XGPCH = 1 (during shift). If XGPCH = 1, the routine proceeds to step 205 where the gear position immediately before the shift determination flag XGPCH is switched from “0” to “1” is read, and the routine proceeds to step 207.

  On the other hand, if XGPCH = 0 (not changing gear), the process proceeds from step 204 to step 206, the gear position corresponding to the output signal GP of the gear position sensor 33 at that time is read, and the process proceeds to step 207.

  In this step 207, the engine speed NE at that time is read, and in the next step 208, the ram pressure correction coefficient FRAM is calculated using a two-dimensional map or function equation using GP and NE as parameters. The ram pressure correction coefficient FRAM is used as one of a fuel injection amount correction coefficient or an ignition timing correction coefficient.

  According to the ram pressure correction coefficient calculation program described above, the ram pressure correction coefficient FRAM is calculated using the gear position immediately before the shift is detected (XGPCH = 1). The correction coefficient FRAM can be set appropriately, and the control characteristics during shifting can be improved.

  In addition, the present invention is not limited to a two-wheeled vehicle, but can be applied to a four-wheeled vehicle.

1 is a schematic configuration diagram of an entire engine control system showing an embodiment of the present invention. Circuit diagram showing the electrical configuration of the main part Flow chart showing the processing flow of the gear position detection program Flow chart showing the processing flow of the ram pressure correction coefficient calculation program

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... Intake manifold, 15 ... Throttle valve, 16 ... Throttle opening sensor, 17 ... Intake pressure sensor, 18 ... Fuel injection valve, 29 ... Engine speed sensor (rotation speed detection means), 32 ... Atmospheric pressure sensor, 33 ... Gear position sensor (gear position detecting means), 34 ... Neutral lamp, 35 ... Engine control circuit (abnormality judging means, judging means during shifting, operating state detecting means, correcting means, vehicle speed limiting means) 36, rotary contact, 45, ROM, S1 to S5, fixed contact for detecting the gear position, Sn, fixed contact for detecting the neutral position, R1 to R5, resistance for detecting the gear position.

Claims (1)

Gear position detecting means for detecting the gear position of the transmission for transmitting the output of the internal combustion engine to the drive wheels;
A neutral lamp that lights when the gear position of the transmission is in the neutral position;
The controller of an internal combustion engine and a determining shift in determining means whether the transmission is in gear shift based on the on / off signal of the output signal and the neutral lamp of the gear position detecting means,
When it is detected by the rotation speed detection means for detecting the rotation speed of the internal combustion engine and the shifting determination means that the speed is being changed, only the gear position immediately before the shift and the rotation speed of the internal combustion engine are used. And a correction means for setting a correction coefficient for the fuel injection amount during the shift or a correction coefficient for the ignition timing during the shift.

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