Straddled vehicle
Patent Information
- Application Number
- PCT/JP2025/006019
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2026-08-27
Smart Images
Figure JP2025006019_27082026_PF_FP_ABST
Abstract
Description
Straddle vehicle
[0001] The present invention relates to a straddle-type vehicle, and more particularly to a straddle-type vehicle that suspends fuel injection by an injector during decelerated travel.
[0002] A straddle-type vehicle that suspends fuel injection by an injector during decelerated travel has been proposed (see, for example, Patent Document 1 below). In the straddle-type vehicle described in Patent Document 1 below, the first braking means and the second braking means are simultaneously operated, and when the vehicle speed reaches the idle-stop acceptable vehicle speed, after shifting from fuel cut during decelerated travel to idle stop, the vehicle stops. Also, when the vehicle speed reaches the idle-stop acceptable vehicle speed while the second braking means is operated and the first braking means is not operated, it shifts from fuel cut during decelerated travel to the idle state. In the idle state, the clutch operates so that low-speed travel that is due to the creep phenomenon of the power transmission system and does not depend on the accelerator operation is performed. Thereafter, when the first braking means and the second braking means are simultaneously operated, after shifting from the idle state to idle stop, the vehicle stops.
[0003] Japanese Patent No. 6147128
[0004] Straddle-type vehicles are required to be agile and maneuverable. Therefore, it is preferable that they can appropriately respond to the rider's intention.
[0005] An object of the present invention is to provide a straddle-type vehicle that can appropriately respond to the rider's intention while expanding the period during which fuel injection by an injector is suspended during decelerated travel, thereby suppressing the rider's sense of discomfort.
[0006] The inventors investigated measures to enable appropriate response to the rider's intentions while extending the period during which fuel injection by the injector is suspended during deceleration. As a result, they obtained the following findings. First, the inventors considered situations in which they wanted to enable appropriate response to the rider's intentions during deceleration. As a result, they found that there are situations like the following. For example, consider a saddle-type vehicle traveling on a public road. When the traffic light ahead turns red, the rider stops operating the accelerator and operates the front brake and / or rear brake. As a result, the saddle-type vehicle decelerates. Here, the saddle-type vehicle is configured so that the rider places their feet on the road surface or ground when stopped. Therefore, when the saddle-type vehicle stops at a stop line before a traffic light, the rider needs to place their feet on the road surface or ground. Therefore, the rider may stop operating the brake lever or reduce the amount of brake lever operation before the stop line in order to avoid placing their feet on the road surface. The inventors further investigated this situation. Specifically, they examined the case where fuel injection by the injector is suspended during deceleration. As a result, they found that it is best to disengage the clutch during deceleration and coast while suspending fuel injection by the injector. Furthermore, they found that when the engine speed drops below the engine speed at which the engine is idling with fuel injection by the injector, and the rider stops operating the brake lever or reduces the amount of operation of the brake lever, the system should transition from coasting with fuel injection suspended by the injector to coasting with fuel injection resumed and the engine idling, and this state of coasting with the engine idling should be continued at least until the saddle-type vehicle comes to a stop.Fuel injection by the injector is suspended until the rider stops operating the brake lever or reduces the amount of operation on the brake lever, thus extending the period during which fuel injection by the injector is suspended during deceleration. After the suspended fuel injection by the injector is resumed, coasting at idle continues at least until the saddle-type vehicle comes to a stop, so it can respond to both cases: when decelerating and coming to a stop (according to the rider's intention to stop) and when stopping deceleration and continuing to travel (according to the rider's intention to drive or request to travel). It can respond appropriately to the rider's intentions. The present invention was completed based on these findings. The present invention adopts the following configuration.
[0007] A saddle-type vehicle according to one embodiment of the present invention comprises: an engine configured such that power generated by the combustion of a fuel-air mixture is output via a crankshaft; an accelerator control configured to be operated by a rider to control the power of the engine; an injector configured to inject fuel to produce the fuel-air mixture according to the amount of operation of the accelerator control; a front wheel and a rear wheel, at least one of which constitute a drive wheel to which power from the engine is transmitted; a front wheel brake control configured to be operated by the rider to control the operation of a front wheel brake configured to brake the front wheel; a rear wheel brake control configured to be operated by the rider to control the operation of a rear wheel brake configured to brake the rear wheel; a clutch configured to allow / disconnect power transmission from the engine to the drive wheels; and a control device, wherein the control device is When the saddle-type vehicle is in motion, the clutch allows power transmission from the engine to the drive wheels, and the accelerator operator is not operated, or the accelerator operator is not operated and at least one of the front brake operator and the rear brake operator is operated by the rider, thereby performing deceleration fuel injection deactivation control, which suspends fuel injection by the injector during deceleration of the saddle-type vehicle, and when this deceleration fuel injection deactivation control is performed, the clutch changes from a state that allows power transmission from the engine to the drive wheels to a state that disconnects it, thereby causing the saddle-type vehicle to coast while suspending fuel injection by the injector during deceleration, and during the coasting of the saddle-type vehicle, When the engine speed of the engine has decreased to a level below that of the engine when fuel injection by the injector is performed and the engine is idle, at least one of the front wheel brake levers and the rear wheel brake levers that has been operated by the rider since the start of the deceleration fuel injection deactivation control is not operated, or the amount of operation of the brake lever is reduced.The system is configured to resume fuel injection by the injector, which had been deactivated, thereby idling the engine while performing COM (Change Of Mind) standby control, in which the clutch disconnects power transmission from the engine to the drive wheels, and to continue this COM standby control at least until the saddle-type vehicle comes to a stop.
[0008] According to one embodiment of the present invention, a saddle-type vehicle can respond appropriately to the rider's intentions while extending the period during which fuel injection by the injector is suspended during deceleration, thereby suppressing discomfort for the rider. More specifically, it is as follows: According to one embodiment of the present invention, when the saddle-type vehicle is in motion, and the clutch is allowing power transmission from the engine to the drive wheels, deceleration fuel injection suspension control is initiated when the accelerator is not operated, or when the accelerator is not operated and at least one of the front wheel brake operator and the rear wheel brake operator is operated by the rider, thereby suspending fuel injection by the injector during deceleration of the saddle-type vehicle. This deceleration fuel injection suspension control continues even during coasting. The period during which fuel injection by the injector is suspended during deceleration can be extended. According to one embodiment of the present invention, when the saddle-type vehicle is coasting, when the engine speed drops below the engine speed when the engine is idling with fuel injection by the injector, the rider either refrains from operating at least one of the front and rear brake levers that has been operated by the rider since the start of the deceleration fuel injection deactivation control, or reduces the amount of operation of the brake lever, thereby reactivating the deactivated fuel injection by the injector. This activates COM standby control, which keeps the engine idling while the clutch disconnects power transmission from the engine to the drive wheels. In other words, the saddle-type vehicle coasts with the engine idling. The saddle-type vehicle transitions from a state of coasting with fuel injection by the injector deactivated to a state of coasting with the engine idling. This COM standby control (i.e., idle state; more specifically, idle state while coasting) continues at least until the saddle-type vehicle comes to a stop. It can respond to both situations: slowing down and coming to a complete stop (in accordance with the rider's intention to stop) and stopping the deceleration and continuing to travel (in accordance with the rider's intention or request to continue driving). It can respond appropriately to the rider's intentions.In other words, according to the saddle-type vehicle of one embodiment of the present invention, as long as the rider intends to decelerate or stop, fuel injection by the injector is suspended, so the period during which fuel injection by the injector is suspended can be extended. Furthermore, after the suspended fuel injection by the injector is resumed, coasting at idle continues at least until the saddle-type vehicle comes to a stop, so it can respond to both cases: when the rider decelerates and stops (in accordance with the rider's intention to stop) and when the rider stops decelerating and continues driving (in accordance with the rider's intention to drive or request to drive). It can respond appropriately to the rider's intentions.
[0009] A saddle-type vehicle is a vehicle equipped with a saddle-type seat. A saddle-type vehicle is a vehicle configured in which the rider sits in a position as if straddling a saddle. Saddle-type vehicles are not limited to scooter-type, moped-type, off-road-type, or on-road-type motorcycles, but also include snowmobiles, watercraft, all-terrain vehicles (ATVs), etc. A saddle-type vehicle is, for example, equipped with at least one front wheel and at least one rear wheel. A saddle-type vehicle is not limited to motorcycles, and may also be a three-wheeled vehicle with either a front or rear wheel consisting of a pair of left and right wheels, or a four-wheeled vehicle with both front and rear wheels consisting of a pair of left and right wheels. A saddle-type vehicle may be configured to turn in a lean position toward the inside of a curve. A saddle-type vehicle is, for example, a vehicle configured so that the rider's feet touch the road surface or ground when stopped. Saddle-type vehicles are configured so that the rider controls the vehicle's posture by shifting their weight, for example, while driving and turning. Therefore, saddle-type vehicles require agility and maneuverability so that posture control can be efficiently performed by the rider's weight shift.
[0010] The engine is the power source for a saddle-type vehicle. Power is generated by the combustion of a fuel-air mixture. Power is output via the crankshaft. The engine is, for example, a spark-ignition engine that burns the fuel-air mixture with a spark plug. The engine is, for example, a reciprocating engine. The engine is, for example, a four-stroke engine. The engine may be a single-cylinder engine or a multi-cylinder engine. A multi-cylinder engine may be a V-type engine, an inline engine, or a horizontally opposed engine. The engine may be a water-cooled engine, an air-cooled engine, or an oil-cooled engine. The crankshaft is, for example, rotatably supported in the crankcase of the engine. The engine may be, for example, a four-stroke engine having a high-load region during the four strokes in which the load on rotating the crankshaft is large and includes the compression stroke, and a low-load region in which the load on rotating the crankshaft is small and does not include the compression stroke. In a four-stroke engine having a high-load region and a low-load region during its four-stroke cycle, torque fluctuations are large, and the torque required when transitioning from the low-load region to the high-load region increases. In a saddle-type vehicle according to an embodiment of the present invention, even when equipped with such an engine, it can respond appropriately to the rider's intentions. A four-stroke engine having a high-load region and a low-load region during its four-stroke cycle is, for example, a single-cylinder engine, a two-cylinder engine, an uneven-interval combustion type three-cylinder engine, or an uneven-interval combustion type four-cylinder engine. However, the engine is not particularly limited, and may also be, for example, an equal-interval combustion type three-cylinder engine or an equal-interval combustion type four-cylinder engine.
[0011] The accelerator control is configured, for example, to be operated by the rider's hand. The rider's operation of the accelerator control controls the engine's power. The rider's operation of the accelerator control causes the saddle-type vehicle to move. The rider's operation of the accelerator control to control the engine's power includes, for example, the rider operating the accelerator control to start the saddle-type vehicle, the rider operating the accelerator control to accelerate the saddle-type vehicle, the rider changing the amount of the accelerator control operation to change the saddle-type vehicle's acceleration, the rider maintaining the amount of the accelerator control operation to keep the saddle-type vehicle moving, and the rider returning the amount of the accelerator control operation to zero to decelerate the saddle-type vehicle. Note that if the amount of the accelerator control operation is maintained at zero, it means that the accelerator control is not being operated. Depending on the amount of the accelerator control operation, the acceleration of the saddle-type vehicle, and consequently the speed of the saddle-type vehicle, changes. For example, a larger press of the accelerator pedal increases the acceleration of the saddle-type vehicle, and consequently, its speed. A smaller press of the accelerator pedal decreases the acceleration of the saddle-type vehicle, and consequently, its speed. When the accelerator pedal is not pressed while the saddle-type vehicle is moving, engine braking occurs. This causes the saddle-type vehicle to decelerate. When the accelerator pedal is not pressed while the saddle-type vehicle is moving, it indicates the rider's intention to decelerate. The accelerator pedal is, for example, an accelerator grip located on the handlebars of the saddle-type vehicle.
[0012] An injector injects fuel, for example, into the combustion chamber of an engine, or into an intake passage connected to the combustion chamber of an engine. The fuel injected by the injector may be a fossil fuel or an alcohol-containing fuel. An example of a fossil fuel is gasoline. An alcohol-containing fuel may be alcohol fuel alone, or a mixture of alcohol fuel and fossil fuel. An example of an alcohol fuel is ethanol or methanol. The injector injects an amount of fuel corresponding to the amount of operation of the accelerator pedal. For example, if the amount of operation of the accelerator pedal increases, the fuel injection amount increases, and if the amount of operation of the accelerator pedal decreases, the fuel injection amount decreases. For example, if the fuel injection amount increases, the engine power increases, and if the fuel injection amount decreases, the engine power decreases. If the engine power increases, the acceleration of the saddle-type vehicle, and consequently the vehicle speed of the saddle-type vehicle, increases. If the engine power decreases, the acceleration of the saddle-type vehicle, and consequently the vehicle speed of the saddle-type vehicle, decreases.
[0013] The drive wheel may be the front wheel or the rear wheel. For example, the drive wheel may be the rear wheel. The power transmission path from the engine to the drive wheel is configured, for example, to reduce the rotation of the crankshaft and transmit it to the drive wheel. The power transmission path from the engine to the drive wheel includes, for example, a transmission. The transmission may be a multi-speed transmission or a continuously variable transmission. In the case of a multi-speed transmission, the saddle-type vehicle may further be equipped with a shift actuator. The shift actuator switches the gear in the multi-speed transmission, for example, according to the driving conditions of the saddle-type vehicle or according to the rider's operation.
[0014] The front brake applies braking force to the front wheel. This reduces the rotational speed of the front wheel, causing the saddle-type vehicle to decelerate. The front brake lever is configured to be operated, for example, by the rider's hand. The front wheel is braked when the rider operates the front brake lever. The rider operating the front brake lever to control the operation of the front brake includes, for example, the rider operating the front brake lever to decelerate or stop the saddle-type vehicle, the rider changing the amount the front brake lever is operated to change the deceleration of the saddle-type vehicle, and the rider returning the amount the front brake lever is operated to zero to stop the deceleration or stop of the saddle-type vehicle. The front brake lever is being operated if the braking force of the front brake is acting on the front brake and the saddle-type vehicle is decelerating. When the front brake lever is operated while the saddle-type vehicle is moving, it indicates the rider's intention to decelerate or stop. The front brake applies braking force to the front wheel with a braking force corresponding to the amount the front brake lever is operated. The front brake, for example, increases the braking force applied to the front wheel when the front brake lever is operated more, and decreases the braking force applied to the front wheel when the front brake lever is operated less. For example, an increase in the braking force applied to the front wheel increases the deceleration of the saddle-type vehicle, and a decrease in the braking force applied to the front wheel decreases the deceleration of the saddle-type vehicle. The front brake lever is, for example, a lever provided on the handlebars of the saddle-type vehicle. For example, when the front brake lever is operated, the rear brake may also be activated along with the front brake. The ratio of the braking force applied to the front wheel to the braking force applied to the rear wheel may be determined, for example, according to the amount the front brake lever is operated.
[0015] The rear brake applies braking force to the rear wheel. This reduces the rotational speed of the rear wheel, causing the saddle-type vehicle to decelerate. The rear brake lever is configured to be operated, for example, by the rider with their hand or foot. The rear wheel is braked when the rider operates the rear brake lever. The rider operating the rear brake lever to control the operation of the rear brake includes, for example, operating the rear brake lever to decelerate or stop the saddle-type vehicle, changing the amount of the lever operated to change the deceleration of the saddle-type vehicle, and returning the amount of the lever operated to zero to stop the deceleration or stopping of the saddle-type vehicle. The rear brake lever is being operated if the braking force of the rear brake is acting on the rear brake and the saddle-type vehicle is decelerating. When the rear brake lever is operated while the saddle-type vehicle is moving, it indicates the rider's intention to decelerate or stop. The rear brake applies braking force to the rear wheel, for example, corresponding to the amount of movement of the rear brake lever. For example, if the amount of movement of the rear brake lever increases, the braking force on the rear wheel increases, and if the amount of movement of the rear brake lever decreases, the braking force on the rear wheel decreases. For example, if the braking force on the rear wheel increases, the deceleration of the saddle-type vehicle increases, and if the braking force on the rear wheel decreases, the deceleration of the saddle-type vehicle decreases. The rear brake lever may be a lever provided on the handlebars of the saddle-type vehicle, or it may be a pedal provided near the footrest where the rider places their feet. For example, when the rear brake lever is operated, the front wheel may also be operated along with the rear brake. The ratio of braking force on the front wheel to braking force on the rear wheel may be determined, for example, according to the amount of movement of the rear brake lever.
[0016] The clutch's ability to allow / disconnect power transmission from the engine to the drive wheels includes, for example, allowing / disconnecting power transmission from the crankshaft to the input shaft in the transmission. By allowing power transmission from the engine to the drive wheels, the clutch enables power transmission from the engine to the drive wheels. By disabling power transmission from the engine to the drive wheels, the clutch prevents power transmission from the engine to the drive wheels. The clutch may be, for example, a centrifugal clutch configured to allow / disconnect power transmission from the engine to the drive wheels depending on the engine speed. In this case, the clutch can be automatically engaged / disconnected depending on the engine speed. The centrifugal clutch is configured to allow / disconnect power transmission from the engine to the drive wheels by utilizing weights moved by the centrifugal force generated by the rotation of the crankshaft. The centrifugal clutch is configured to allow / disconnect power transmission from the engine to the drive wheels by changing the engagement state between a first friction plate and a second friction plate using weights moved by the centrifugal force generated by the rotation of the crankshaft. The centrifugal clutch engages, for example, when a saddle-type vehicle starts moving. A centrifugal clutch engages, for example, when the rotational speed of the crankshaft increases. Clutch-in means, for example, that the centrifugal clutch begins to allow power transmission from the engine to the drive wheels. The centrifugal clutch may be, for example, an operable centrifugal clutch. An operable centrifugal clutch may be configured to forcibly interrupt power transmission from the engine to the drive wheels, regardless of the centrifugal force generated by the rotation of the crankshaft, when an operation is performed to interrupt power transmission from the engine to the drive wheels. This forced interruption of power transmission may be performed by transmitting an operating force to the rider's clutch lever, or by transmitting the output of the clutch actuator. If it is performed by transmitting the output of the clutch actuator, the clutch actuator may be driven in response to the rider's operation to the clutch lever. The clutch actuator may also be driven in response to a command from a control device, without any operation by the rider.The clutch may include, for example, a clutch mechanism and a clutch actuator. The clutch mechanism includes, for example, an engageable first friction plate and a second friction plate. The clutch actuator is configured to operate the clutch mechanism according to the driving conditions of the saddle-type vehicle. That is, the clutch may be configured to allow / disconnect power transmission from the engine to the drive wheels by changing the engagement state of the first friction plate and the second friction plate in the clutch mechanism using the output of the clutch actuator. In other words, the clutch may be configured to allow / disconnect power transmission from the engine to the drive wheels based on the operation of the clutch actuator. When the clutch comprises a clutch mechanism and a clutch actuator as described above, the saddle-type vehicle may further include a clutch operator. In this case, the rider operates the clutch operator, causing the clutch to forcibly disconnect power transmission from the engine to the drive wheels. That is, the clutch may forcibly disconnect power transmission from the engine to the drive wheels in response to the rider's operation.
[0017] A control device is, for example, an ECU (Electronic Control Unit). An ECU is implemented by a combination of, for example, an IC (Integrated Circuit), electronic components, a circuit board, etc. The control performed by the control device is implemented, for example, by a CPU (Central Processing Unit) reading a program stored in non-volatile memory and executing predetermined processing according to that program.
[0018] A saddle-type vehicle further includes, for example, a sensor that detects whether the saddle-type vehicle is in motion. The control device is configured, for example, to receive a signal from the sensor. The sensor is, for example, a vehicle speed sensor. The saddle-type vehicle is in motion if, for example, the vehicle speed is greater than zero. A saddle-type vehicle further includes, for example, a sensor that detects the amount of operation of the accelerator pedal. The control device is configured, for example, to receive a signal from the sensor. The sensor is, for example, an accelerator operation detection sensor. The accelerator pedal is not being operated if, for example, the amount of operation of the accelerator pedal is zero. A saddle-type vehicle further includes, for example, a sensor that detects whether at least one of the front wheel brake pedal and the rear wheel brake pedal is being operated. The control device is configured, for example, to receive a signal from the sensor. The sensor is, for example, a brake operation detection sensor. The brake operation detection sensor is, for example, a front wheel brake operation detection sensor that detects whether the front wheel brake pedal is being operated, and / or a rear wheel brake operation detection sensor that detects whether the rear wheel brake pedal is being operated. Detecting whether the brake lever is being operated may involve detecting whether the brake lever is being operated or detecting the amount of brake lever operation. For example, if the clutch comprises a clutch mechanism and a clutch actuator, the saddle-type vehicle may further include a sensor for detecting the state of the clutch. The control device may be configured, for example, to receive a signal from the sensor. Alternatively, if the control device controls the operation of the clutch actuator, the control device may determine the state of the clutch by referring to the operation of the clutch actuator.
[0019] The control device may, for example, refer to the vehicle speed of the saddle-type vehicle, the time the accelerator pedal is not being operated, the time the brake pedal is being operated, and changes in the amount the brake pedal is being operated when deciding whether or not to perform fuel injection deactivation control during deceleration.
[0020] In a saddle-type vehicle, for example, deceleration begins when the accelerator is not operated while the clutch is still allowing power transmission from the engine to the drive wheels. For example, if a saddle-type vehicle is equipped with a stepped transmission, downshifting will increase the deceleration of the saddle-type vehicle. The deceleration of a saddle-type vehicle will also increase when at least one of the front and rear brake levers is operated by the rider.
[0021] Coasting refers to the movement of a saddle-type vehicle while the clutch is engaged, for example, to disconnect power transmission from the engine to the drive wheels. A saddle-type vehicle begins coasting when, for example, the clutch engages to disconnect power transmission from the engine to the drive wheels during deceleration.
[0022] A saddle-type vehicle further includes, for example, a sensor for detecting the rotation of the crankshaft. A control device is configured, for example, to receive a signal from the sensor. The sensor is, for example, an encoder. The control device may, for example, calculate the rotational speed of the crankshaft based on the signal from the sensor for detecting the rotation of the crankshaft, and determine whether the calculated rotational speed of the crankshaft is less than the rotational speed of the crankshaft in an idle state.
[0023] Of the front and rear brake levers, the brake lever operated by the rider after the start of the deceleration fuel injection deactivation control is, for example, if the deceleration fuel injection deactivation control is performed when the accelerator lever is no longer operated, it is sufficient to have a brake lever related to a brake operation performed after the point in time when the accelerator lever is no longer operated. For example, if the accelerator lever is not operated and the deceleration fuel injection deactivation control is performed when at least one of the front and rear brake levers is operated by the rider, it may be the brake lever related to the brake operation that triggered the deceleration fuel injection deactivation control, or it may not be the brake lever related to the rider's brake operation that triggered the deceleration fuel injection deactivation control. The control device performs COM standby control, for example, in the coasting of a saddle-type vehicle, by reducing the amount of operation of the brake lever related to the rider's brake operation performed after the start of the deceleration fuel injection deactivation control when the engine speed has decreased to below the engine speed when fuel injection by the injector is performed and the engine is in an idle state. Reducing the amount of operation of the brake levers related to the rider's braking operation performed after the start of the deceleration fuel injection deactivation control means, for example, if the brake levers related to the rider's braking operation performed after the start of the deceleration fuel injection deactivation control are the front brake levers and the rear brake levers, then reducing the amount of operation of at least one of the front brake levers and the rear brake levers; if the brake levers related to the rider's braking operation performed after the start of the deceleration fuel injection deactivation control are the front brake levers, then reducing the amount of operation of the front brake levers; and if the brake levers related to the rider's braking operation performed after the start of the deceleration fuel injection deactivation control are the rear brake levers, then reducing the amount of operation of the rear brake levers. For example, consider a case where both the front and rear brakes operate when the rider operates either the front brake lever or the rear brake lever.In this case, the brake levers related to the rider's braking operation performed after the start of the deceleration fuel injection deactivation control refer to, for example, the front brake lever or the rear brake lever that triggered the activation of both the front and rear brakes. In this case, reducing the amount of operation of the brake levers related to the rider's braking operation performed after the start of the deceleration fuel injection deactivation control refers to, for example, reducing the amount of operation of the front brake lever or the rear brake lever that triggered the rider's braking operation that triggered the activation of both the front and rear brakes. Reducing the amount of operation of the brake levers includes, for example, setting the amount of operation of the brake levers to zero, that is, ceasing to operate the brake levers. Reducing the amount of operation of the brake levers indicates the rider's intention to drive or request to drive, or more specifically, the rider's intention to continue driving. For example, consider a scenario where, after deceleration fuel injection deactivation control is initiated due to the accelerator pedal being stopped being operated, either the front brake pedal or the rear brake pedal is operated, and the other of the front and rear brake pedals is also operated when the control device decides whether or not to perform COM standby control. In this case, reducing the amount of operation of either the front or rear brake pedal corresponds to reducing the amount of operation of the brake pedal related to a brake operation performed after the accelerator pedal was stopped being operated, that is, reducing the amount of operation of the brake pedal related to a brake operation performed by the rider after the start of deceleration fuel injection deactivation control. For example, consider a scenario where, with the accelerator pedal not being operated, deceleration fuel injection deactivation control is initiated due to the operation of either the front or rear brake pedal, and the other of the front and rear brake pedals is also operated when the control device decides whether or not to perform COM standby control.In this case, reducing the amount of operation of the brake lever for one operation corresponds to reducing the amount of operation of the brake lever for the brake operation that triggered the deceleration fuel injection deactivation control, and reducing the amount of operation of the brake lever for the other operation corresponds to reducing the amount of operation of a brake lever different from the brake lever for the brake operation that triggered the deceleration fuel injection deactivation control.
[0024] Assume a situation where the control device is performing deceleration fuel injection deactivation control, and the engine speed is higher than the engine speed when fuel injection by the injector is active and the engine is idle. In this situation, if the amount of operation of the brake lever operated by the rider decreases, the control device may, for example, continue the deceleration fuel injection deactivation control. Assume a situation where the saddle-type vehicle is coasting while fuel injection by the injector is deactivated, and the engine speed drops below the engine speed when fuel injection by the injector is active and the engine is idle. In this situation, if the amount of operation of the brake lever operated by the rider does not decrease, the control device may, for example, continue the deceleration fuel injection deactivation control. For example, when the control device is performing COM standby control and the saddle-type vehicle comes to a stop, the control device may deactivate fuel injection by the injector, or it may continue fuel injection by the injector to maintain the engine in an idle state. For example, when the control device is in a state where it has suspended fuel injection by the injectors without performing COM standby control (i.e., the control device is performing deceleration fuel injection suspension control), and the saddle-type vehicle comes to a stop, the control device may continue to suspend fuel injection by the injectors. When the accelerator pedal is operated while the saddle-type vehicle is stopped with fuel injection by the injectors suspended, the control device may resume the suspended fuel injection by the injectors. For example, when the control device is performing deceleration fuel injection suspension control, if the accelerator pedal is operated, the control device may discontinue the deceleration fuel injection suspension control.
[0025] The control device may be configured to monitor both the front and rear brakes when deciding whether or not to perform COM standby control. In this case, it becomes easier to understand the rider's COM (Change Of Mind). Monitoring the operation of both the front and rear brakes may mean, for example, monitoring the operation of both the front brake lever and the rear brake lever, or monitoring the operation of an actuator that controls the operation of both the front and rear brakes, where operation of either the front or rear brake lever activates both brakes.
[0026] An embodiment of the present invention of a saddle-type vehicle may further include a motor-generator connected to a crankshaft. The motor-generator is, for example, a rotating electric machine configured to generate electricity in conjunction with the rotation of the crankshaft. The motor-generator is, for example, a rotating electric machine configured to output power to rotate the crankshaft. The direction of rotation of the crankshaft by the motor-generator is, for example, the forward rotation direction of the crankshaft. The forward rotation direction of the crankshaft is, for example, the same direction as the rotation direction of the crankshaft when the engine outputs power. The motor-generator is, for example, a rotating electric machine configured to output power to rotate the crankshaft when the engine is started. That is, the saddle-type vehicle may be configured to start the engine with a motor-generator, or it may have a starter motor for starting the engine separately from the motor-generator. The motor-generator may be of outer rotor type or inner rotor type. The motor-generator may be of radial gap type or axial gap type. Embodiments of how the motor-generator is connected to the crankshaft include, for example, an embodiment in which the motor-generator is connected to the crankshaft so as to rotate at a fixed speed ratio with the crankshaft. For an electric generator to be connected to a crankshaft so as to rotate at a fixed speed ratio with the crankshaft means, for example, that there is no power disconnection means or speed change means such as a clutch between the electric generator and the crankshaft.
[0027] In embodiments where the saddle-type vehicle further comprises an electric generator connected to the crankshaft, the electric generator may be configured to assist the engine in driving the saddle-type vehicle when starting and / or accelerating. Specifically, the control device may be configured to control the electric generator so that it promotes an increase in the rotational speed of the crankshaft when starting and / or accelerating the saddle-type vehicle. In this case, the control device can respond appropriately to the rider's intention, specifically the rider's intention to drive or driving request. Assistance by the electric generator is performed, for example, by suppressing the decrease in crankshaft rotational speed associated with clutch engagement. To suppress the decrease in crankshaft rotational speed associated with clutch engagement, for example, the rotational load on the crankshaft by the electric generator is reduced, or forward torque is applied to the crankshaft by the electric generator. The reduction in the rotational load on the crankshaft by the electric generator is performed, for example, by the electric generator stopping or reducing the amount of power generated in conjunction with the rotation of the crankshaft. The application of forward rotation torque to the crankshaft by the motor-generator is performed, for example, by the motor-generator rotating the crankshaft in the forward rotation direction. Forward rotation torque is the torque applied to the crankshaft in the forward rotation direction. Forward rotation torque is the torque that accelerates the rotation of the crankshaft. The forward rotation direction of the crankshaft is the direction in which the crankshaft rotates when the engine outputs power. A mode in which the control device controls the motor-generator includes, for example, a mode in which the control device outputs commands to a driver for controlling the motor-generator, and the driver controls the motor-generator based on the commands from the control device. The control device controls the motor-generator, for example, so that the motor-generator promotes an increase in the rotational speed of the crankshaft from a start timing to an end timing. The start timing is, for example, when the rotational speed of the crankshaft is lower than, the same as, or higher than the rotational speed at clutch engagement. The end timing is, for example, when the rotational speed of the crankshaft is higher than the rotational speed at the start timing and lower than, the same as, or higher than the rotational speed at clutch engagement.
[0028] The motor-generator may include an inner stator having a stator core with multiple slots spaced apart in the circumferential direction and multiple phase windings arranged to pass through the slots, and a flywheel having a permanent magnet section provided on the outside of the inner stator in the radial direction and a back yoke section provided on the outside of the permanent magnet section in the radial direction, and rotating in conjunction with the rotation of the crankshaft. The flywheel may have magnetic pole surfaces arranged in the circumferential direction of the motor-generator and more than two-thirds of the number of slots on the inner circumferential surface of the permanent magnet section in the radial direction of the motor-generator, and may be configured to rotate at least when the engine is started by changing the current supplied to each phase winding by the control device. Since the flywheel has magnetic pole surfaces more than two-thirds of the number of slots, the number of magnetic poles is increased. The magnetic flux density is increased, and leakage flux between the stator cores that does not become linked flux is reduced, thus ensuring output torque when the engine is started. In addition, the angular velocity ω is increased due to the increased number of magnetic poles. This reduces the detent torque, allowing the engine to quickly increase its rotational speed from a standstill. Additionally, the increased number of magnetic poles raises the frequency of the current supplied to each phase winding, improving the continuity of the output torque during engine startup. For example, even in a four-stroke engine that has a high-load region during the four-stroke cycle where the load on the crankshaft is large and includes the compression stroke, and a low-load region where the load on the crankshaft is small and does not include the compression stroke, the effect of the load in the high-load region is suppressed.
[0029] The above-mentioned and other objectives, features, aspects and advantages of this invention will become more apparent from the following detailed description of embodiments of this invention made in reference to the accompanying drawings. As used herein, the term "and / or" includes any or all combination of one or more related enumerated items. As used herein, the use of the terms "including," "comprising," or "having" and their variations specifies the presence of described features, processes, operations, elements, components and / or equivalents thereof, but may include one or more of steps, operations, elements, components and / or groups thereof. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology and this disclosure, and not as ideal or overly formal unless expressly defined herein. It is understood that numerous technologies and processes are disclosed in this description of the invention. Each of these has its own individual benefit, and each can be used in conjunction with one or more, or possibly all, of the other disclosed technologies. Therefore, for clarity, this description refrains from unnecessarily repeating all possible combinations of the individual steps. Nevertheless, the specification and claims should be read with the understanding that all such combinations are within the scope of the invention and claims. The following description provides numerous specific details for illustrative purposes to provide a complete understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without these specific details. This disclosure should be considered illustrative of the invention and is not intended to limit the invention to the specific embodiments shown in the following drawings or description.
[0030] According to the present invention, it is possible to provide a saddle-type vehicle that can appropriately respond to the rider's intentions while extending the period during which fuel injection by the injector is suspended during deceleration, thereby suppressing discomfort for the rider.
[0031] This is an explanatory diagram showing a saddle-type vehicle according to an embodiment of the present invention. This is a flowchart showing an example of control processing performed by a control device provided in a saddle-type vehicle according to an embodiment of the present invention. This is an explanatory diagram showing a modified example of, where (A) shows a case where the clutch is a centrifugal clutch, and (B) shows a case where an electric generator is further provided. (A) is a vertical cross-sectional view showing an electric generator connected to a crankshaft, and (B) is a schematic cross-sectional view showing the flywheel and inner stator of the electric generator.
[0032] The details of a saddle-type vehicle according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that the embodiments described below are merely examples. The present invention is not to be interpreted in any way as being limited by the embodiments described below.
[0033] A saddle-type vehicle 10 according to an embodiment of the present invention will be described with reference to Figure 1. The saddle-type vehicle 10 comprises an engine 12, an accelerator control 14, an injector 16, a front wheel 18F, a rear wheel 18R, a front brake 20F, a rear brake 20R, a front brake control 22F, a rear brake control 22R, a clutch 24, and a control device 26.
[0034] The engine 12 is configured such that the power generated by the combustion of the air-fuel mixture is output via the crankshaft 121. The accelerator lever 14 is configured to be operated by the rider to control the power of the engine 12. The injector 16 is configured to inject fuel to produce the air-fuel mixture according to the amount the accelerator lever 14 is operated. At least one of the front wheel 18F and the rear wheel 18R constitutes the drive wheel to which the power of the engine 12 is transmitted. In the example shown in Figure 1, the rear wheel 18R constitutes the drive wheel. The front brake 20F is configured to brake the front wheel 18F. The front brake lever 22F is configured to be operated by the rider to control the operation of the front brake 20F. The rear brake 20R is configured to brake the rear wheel 18R. The rear brake lever 22R is configured to be operated by the rider to control the operation of the rear brake 20R. The clutch 24 is configured to allow / disconnect the transmission of power from the engine 12 to the drive wheel (rear wheel 18R). The control device 26 is configured to perform deceleration fuel injection deactivation control, which suspends fuel injection by the injector 16 when the saddle-type vehicle 10 is decelerating, when the accelerator pedal is not operated while the clutch 24 is allowing power transmission from the engine 12 to the drive wheels (rear wheels 18R) while the saddle-type vehicle 10 is in motion. When this deceleration fuel injection deactivation control is performed, the clutch 24 changes from a state where power transmission from the engine 12 to the drive wheels (rear wheels 18R) is allowed to be transmitted to the drive wheels (rear wheels 18R) to a state where it is disconnected, and as a result, the saddle-type vehicle 10 coasts while suspending fuel injection by the injector 16 during deceleration.The control device 26 is configured to perform COM (Change Of Mind) standby control in which the clutch 24 disconnects power transmission from the engine 12 to the drive wheels (rear wheels 18R) while the saddle-type vehicle 10 is coasting, when the engine speed of the engine 12 has decreased to less than the engine speed when the engine is idle due to fuel injection by the injector, by not operating at least one of the front wheel brake lever 22F and rear wheel brake lever 22R that has been operated by the rider since the start of the deceleration fuel injection deactivation control, or by reducing the amount of operation of the brake lever, thereby reactivating the fuel injection by the deactivated injector 16, and thereby keeping the engine 12 in an idle state. This COM standby control continues at least until the saddle-type vehicle 10 comes to a stop.
[0035] The control process performed by the control device 26 will be explained with reference to Figure 2. First, in step S1, the control device 26 determines whether the conditions for performing deceleration fuel injection deactivation control are met. These conditions are that when the saddle-type vehicle 10 is in motion, the clutch 24 allows power transmission from the engine 12 to the drive wheels (rear wheels 18R), and the accelerator pedal is not operated. If these conditions are met (step S1: YES), the control device 26 performs deceleration fuel injection deactivation control in step S2. If these conditions are not met (step S1: NO), the control device 26 terminates the control process shown in Figure 2. Next, in step S3, the control device 26 determines whether or not to perform COM standby control. The condition is that, during coasting of the saddle-type vehicle 10, when the engine speed of the engine 12 has decreased to less than the engine speed when the engine is idling due to fuel injection by the injector, at least one of the front brake levers 22F and rear brake levers 22R that has been operated by the rider since the start of the deceleration fuel injection deactivation control is not operated, or the amount of operation of the brake lever is reduced. If this condition is met (step S3: YES), the control device 26 performs COM standby control in step S4. If this condition is not met (step S3: NO), the control device 26 terminates the control process shown in Figure 2. Regarding the coasting of the saddle-type vehicle 10, for example, the determination is made as follows: If the clutch 24 is equipped with a clutch mechanism and a clutch actuator, the control device 26 determines whether the saddle-type vehicle 10 is coasting or not based on, for example, the operating state of the clutch actuator. If the clutch 24 includes a clutch mechanism and a clutch actuator, the control device 26 determines, for example, whether to disconnect the power transmission by the clutch 24 and allow the saddle-type vehicle 10 to coast, based on the vehicle speed and engine speed of the saddle-type vehicle 10. If the clutch 24 is a centrifugal clutch, the control device 26 determines, for example, whether the saddle-type vehicle is coasting, based on the engine speed.
[0036] According to the saddle-type vehicle 10, the period during which fuel injection by the injector 16 is suspended during deceleration can be extended while responding appropriately to the rider's intentions, thereby suppressing discomfort for the rider.
[0037] As shown in Figure 3, the control device 26 may be configured to perform deceleration fuel injection deactivation control, which suspends fuel injection by the injector 16 when the saddle-type vehicle 10 is decelerating, when the clutch 24 is allowing power transmission from the engine 12 to the drive wheels (rear wheels 18R) while the accelerator is not operated and either the front brake operator 22F or the rear brake operator 22R is operated, while the saddle-type vehicle 10 is traveling. The control device 26 may be configured to monitor both the front brake 20F and the rear brake 20R when deciding whether or not to perform COM standby control. As shown in Figure 4(A), the clutch 24 may be a centrifugal clutch 24A configured to allow / disconnect power transmission from the engine 12 to the drive wheels (rear wheels 18R) according to the engine speed. The engine 12 may be a four-stroke engine having a high-load region during the four strokes in which the load rotating the crankshaft 121 is large and includes a compression stroke, and a low-load region in which the load rotating the crankshaft 121 is small and does not include a compression stroke. As shown in Figure 4(B), the saddle-type vehicle 10 may further include an electric generator 28 connected to the crankshaft 121. The electric generator 28 may be configured to assist the engine 12 in driving the saddle-type vehicle 10 when starting and / or accelerating the saddle-type vehicle 10. As shown in Figures 5(A) and (B), the motor-generator 28 may include an inner stator 30 having a stator core ST in which a plurality of slots SL are formed with a spacing d in the circumferential direction, and a plurality of phase windings W provided so as to pass through the slots SL, and a flywheel 36 having a permanent magnet portion 32 provided on the outside of the inner stator 30 in the radial direction and a back yoke portion 34 provided on the outside of the permanent magnet portion 32 in the radial direction, and rotating in conjunction with the rotation of the crankshaft 121. The flywheel 36 may have magnetic pole surfaces arranged in the circumferential direction of the motor-generator 28 and more than 2 / 3 of the number of slots SL on the inner circumferential surface of the permanent magnet portion 32 in the radial direction of the motor-generator 28, and may be configured to rotate at least when the engine 12 is started by changing the current supplied to each phase winding by the control device 26.
[0038] (Other Embodiments) Embodiments and modifications described and illustrated herein are for the purpose of facilitating the understanding of this disclosure and do not limit the spirit of this disclosure. The above embodiments and modifications may be modified and improved without departing from the spirit. This spirit includes equivalent elements, modifications, deletions, combinations (e.g., combinations of features spanning embodiments and modifications), improvements, and changes that can be recognized by a person skilled in the art based on the embodiments disclosed herein. The limitations in the claims should be interpreted broadly based on the terms used in those claims and should not be limited to the embodiments and modifications described herein or in the prosecution of this application. Such embodiments and modifications should be interpreted as non-exclusive. For example, in this specification, the terms “preferred” and “good” are non-exclusive and mean “preferred but not limited to” and “good but not limited to.”
[0039] 10 Saddle-type vehicle 12 Engine 121 Crankshaft 14 Accelerator control 16 Injector 18F Front wheel 18R Rear wheel 20F Front brake 20R Rear brake 22F Front brake control 22R Rear brake control 24 Clutch 26 Control device
Claims
1. A saddle-type vehicle comprising: an engine configured such that power generated by the combustion of a fuel-air mixture is output via a crankshaft; an accelerator control configured to be operated by a rider to control the power of the engine; an injector configured to inject fuel to produce the fuel-air mixture according to the amount of operation of the accelerator control; a front wheel and a rear wheel, at least one of which constitute a drive wheel to which the power of the engine is transmitted; a front brake control configured to be operated by the rider to control the operation of a front brake configured to brake the front wheel; a rear brake control configured to be operated by the rider to control the operation of a rear brake configured to brake the rear wheel; a clutch configured to allow / disconnect power transmission from the engine to the drive wheels; and a control device, wherein the control device, when the saddle-type vehicle is running, is configured such that the clutch allows power transmission from the engine to the drive wheels and the accelerator control is not operated, or the accelerator control is not operated and at least one of the front brake control and the rear brake control is operated by the rider, When the saddle-type vehicle is decelerating, a deceleration fuel injection deactivation control is performed to suspend fuel injection by the injector, and when this deceleration fuel injection deactivation control is performed, the clutch changes from a state that allows power transmission from the engine to the drive wheels to a state that disconnects it, thereby causing the saddle-type vehicle to coast while suspending fuel injection by the injector during deceleration, and during the coasting of the saddle-type vehicle, when the engine speed of the engine has decreased to less than the engine speed when the engine is idling with fuel injection by the injector, at least one of the front wheel brake levers and the rear wheel brake levers that has been operated by the rider since the start of the deceleration fuel injection deactivation control is not operated, or the amount of operation of the brake lever is reduced,The system is configured to resume fuel injection by the injector, which had been deactivated, thereby idling the engine while performing COM (Change Of Mind) standby control, in which the clutch disconnects power transmission from the engine to the drive wheels, and to continue this COM standby control at least until the saddle-type vehicle comes to a stop.
2. A saddle-type vehicle according to claim 1, wherein the control device is configured to monitor the operation of both the front brake and the rear brake when deciding whether or not to perform the COM standby control.
3. A saddle-type vehicle according to claim 1 or 2, wherein the clutch is a centrifugal clutch configured to allow / disconnect power transmission from the engine to the drive wheels according to the engine speed.
4. A saddle-type vehicle according to any one of claims 1 to 3, wherein the engine is a four-stroke engine having, during the four strokes, a high-load region in which the load that rotates the crankshaft is large and includes a compression stroke, and a low-load region in which the load that rotates the crankshaft is small and does not include a compression stroke.
5. A saddle-type vehicle according to any one of claims 1 to 4, further comprising an electric generator connected to the crankshaft, wherein the electric generator is configured to assist the engine in driving the saddle-type vehicle when the saddle-type vehicle is starting and / or accelerating.
6. A saddle-type vehicle according to any one of claims 1 to 5, further comprising an electric generator connected to the crankshaft, the electric generator including an inner stator having a stator core with a plurality of slots formed circumferentially spaced apart and a plurality of phase windings provided to pass through the slots, and a flywheel having a permanent magnet portion provided radially outside the inner stator and a back yoke portion provided radially outside the permanent magnet portion, and rotating in conjunction with the rotation of the crankshaft, the flywheel having magnetic pole surfaces arranged circumferentially around the electric generator and more than 2 / 3 of the number of slots on the inner circumferential surface of the permanent magnet portion radially around the electric generator, and configured to rotate at least when the engine is started by changing the current supplied by the control device to each phase winding.