Vehicle with automatic downshift function

1. A vehicle with an automatic downshift function, the vehicle comprising:

an engine including a throttle device and an ignition device;

an engine speed sensor which detects an engine speed;

a shift operation member which is operated by a rider to perform speed change;

a manual transmission connected to the engine, the manual transmission being configured to select one of gears corresponding to a plurality of transmission gear positions, respectively, in response to an operation of the shift operation member performed by the rider, and to place the selected gear in a driving power transmission state;

a shift operation sensor which detects the operation of the shift operation member performed by the rider;

a gear position sensor which detects a transmission gear position selected from among the plurality of transmission gear positions, and

a controller which controls the engine based on a detection signal of the engine speed sensor, a detection signal of the gear position sensor, and a detection signal of the shift operation sensor, wherein

the controller performs an automatic downshift control, and

in the automatic downshift control:

in a case where the controller determines that a deceleration shift operation has been initiated based on the detection signal of the shift operation sensor, the controller controls the throttle device to increase an intake-air amount of the engine and controls the ignition device to change an ignition timing, based on the engine speed detected by the engine speed sensor, and

in a case where the controller determines that a deceleration shift movement of the manual transmission has been completed based on the detection signal of the gear position sensor, the controller controls the ignition device to return the ignition timing to one in a normal state.

2. The vehicle with the automatic downshift function according to claim 1 ,

wherein in a case where the controller determines that the deceleration shift movement of the manual transmission has been completed, the controller controls the ignition device so that the ignition timing returns to an ignition timing in the normal state over time.

3. A vehicle with an automatic downshift function, the vehicle comprising:

an engine including a throttle device and an ignition device;

an engine speed sensor which detects an engine speed;

a shift operation member which is operated by a rider to perform speed change;

a manual transmission connected to the engine, the manual transmission being configured to select one of gears corresponding to a plurality of transmission gear positions, respectively, in response to an operation of the shift operation member performed by the rider, and to place the selected gear in a driving power transmission state;

a shift operation sensor which detects the operation of the shift operation member performed by the rider;

a gear position sensor which detects a transmission gear position selected from among the plurality of transmission gear positions; and

a controller which controls the engine based on a detection signal of the engine speed sensor and a detection signal of the shift operation sensor, wherein

the controller performs an automatic downshift control, and

in the automatic downshift control, in a case where the controller determines that a deceleration shift operation has been initiated based on the detection signal of the shift operation sensor, the controller controls the throttle device to increase an intake-air amount of the engine based on the engine speed detected by the engine speed sensor without reference to the transmission gear position detected by the gear position sensor, and controls the ignition device to change an ignition timing based on the transmission gear position detected by the gear position sensor.

4. A vehicle with an automatic downshift function, the vehicle comprising:

an engine including a throttle device and an ignition device;

an engine speed sensor which detects an engine speed;

a shift operation member which is operated by a rider to perform speed change;

a manual transmission connected to the engine, the manual transmission being configured to select one of gears corresponding to a plurality of transmission gear positions, respectively, in response to an operation of the shift operation member performed by the rider, and to place the selected gear in a driving power transmission state;

a shift operation sensor which detects the operation of the shift operation member performed by the rider;

a gear position sensor which detects a transmission gear position selected from among the plurality of transmission gear positions; and

a controller which controls the engine based on a detection signal of the engine speed sensor, a detection signal of the gear position sensor and a detection signal of the shift operation sensor,

wherein in a case where the controller determines that a deceleration shift operation has been initiated, the controller controls the ignition device to change a phase of an ignition timing, and decides a phase change amount of the ignition timing based on the transmission gear position detected by the gear position sensor.

5. The vehicle with the automatic downshift function according to claim 4 ,

wherein the controller changes a phase of the ignition timing by retarding the ignition timing, and increases a retard amount of the ignition timing as the transmission gear position in deceleration shift is higher.

6. The vehicle with the automatic downshift function according to claim 4 ,

wherein in a case where a transmission gear ratio difference in deceleration shift is maximum, the controller controls the throttle device to increase an intake-air amount of the engine without changing the ignition timing of the ignition device, and

wherein in a case where the transmission gear ratio difference in the deceleration shift is not maximum, the controller controls the ignition device to retard the ignition timing.

7. A vehicle with an automatic downshift function, the vehicle comprising:

an engine including a throttle device and an ignition device;

an engine speed sensor which detects an engine speed;

a shift operation member which is operated by a rider to perform speed change;

a manual transmission connected to the engine, the manual transmission being configured to select one of gears corresponding to a plurality of transmission gear positions, respectively, in response to an operation of the shift operation member performed by the rider, and to place the selected gear in a driving power transmission state;

a shift operation sensor which detects the operation of the shift operation member performed by the rider;

a gear position sensor which detects a transmission gear position selected from among the plurality of transmission gear positions; and

a controller which controls the engine based on a detection signal of the engine speed sensor, a detection signal of the gear position sensor and a detection signal of the shift operation sensor, wherein

in a case where a predetermined control condition is met, the controller performs an automatic downshift control,

the predetermined condition includes a condition in which a speed of the vehicle is higher than a first threshold, the engine speed is higher than a second threshold and lower than a third threshold, and a throttle opening rate of the throttle device is less than a fourth threshold, and

in the automatic downshift control, in a case where the controller determines that a deceleration shift operation has been initiated based on the detection signal of the shift operation sensor, the controller controls the throttle device to increase an intake-air amount of the engine and controls the ignition device to change an ignition timing, based on the engine speed detected by the engine speed sensor.