Transmission control apparatus

Abstract

When a first abnormality that is an abnormality in transmission assist control occurs in a state in which manual mode driving or automatic mode driving is possible, a transmission control apparatus (4) transitions to a retraction mode in which a change in the gear stage of a dog-type transmission (T) when engagement between dogs of the dog-type transmission (T) is released or weakened is permitted without depending on the transmission assist control.

Description

Shift control device

[0001] The present invention relates to a shift control device mounted on a motorcycle.

[0002] Conventionally, there has been known a shift control device that performs control for switching the gear stage of a transmission by an actuator such as an electric motor in a motorcycle. Further, conventionally, in a motorcycle equipped with a shift control device, when a driver switches a mode changeover switch and operates a shift switch, the shift control device drives an actuator to change the gear stage of the transmission. It is also known that it is possible to select between manual mode operation in which the gear stage is changed, and automatic mode operation in which the shift control device automatically drives an actuator according to the running state of the motorcycle to change the gear stage of the transmission.

[0003] Further, some conventional motorcycles include a dog-type transmission. In such a dog-type transmission, without the driver operating the main clutch, the dogs (dog teeth) of the dog-type transmission come into contact with each other, and one of the engine and the drive wheels drives the other. A shift operation can be performed in this state. This allows the driver to omit the operation of the main clutch and perform a quick shift.

[0004] Under such circumstances, Patent Document 1 discloses a shift control device that restricts automatic mode operation and permits manual mode operation when a predetermined failure occurs. This improves limp-home performance in a motorcycle capable of switching between manual mode operation and automatic mode operation.

[0005] Japanese Patent Application Laid-Open No. 2010-151307

[0006] However, in Patent Document 1, since the system automatically switches to manual mode operation when a predetermined failure occurs, there is room for improvement in improving the limp-home performance when shifting with a dog-type transmission.

[0007] An object of the present invention is to provide a shift control device capable of improving limp-home performance when an abnormality occurs when changing the gear stage of a dog-type transmission.

[0008] To achieve the above objectives, the present invention provides a gear control device mounted on a motorcycle equipped with a dog-type transmission having multiple gear stages and an actuator for changing the gear stages of the transmission, which enables manual mode operation in which the actuator changes the gear stages of the transmission based on the operation of the motorcycle driver, or automatic mode operation in which the actuator changes the gear stages of the transmission based on the driving state of the motorcycle, wherein the device performs gear assist control that temporarily changes the output of the drive source of the motorcycle in order to disengage or weaken the engagement between the dogs of the transmission and enable gear shifting of the transmission. The system comprises a control unit 1 and a second control unit capable of performing a gear change of the transmission by controlling the drive of the actuator when the engagement of the transmission dogs is released or weakened by the execution of the gear change assist control of the first control unit, thereby enabling gear changes of the transmission. In one phase, the second control unit, when a first abnormality, which is an abnormality of the gear change assist control, occurs while manual mode operation or automatic mode operation is possible, transitions to a retraction mode that permits gear changes when the engagement of the transmission dogs is released or weakened without the gear change assist control.

[0009] According to one aspect of the present invention, a gear shift control device includes: a first control unit that performs gear shift assist control to temporarily change the output of the drive source of a motorcycle so that the engagement between the dogs of the gear shift is released or weakened so that the gear shift of the gear shift can be made possible; and a second control unit that can perform gear shifting by controlling the drive of an actuator when the engagement between the dogs of the gear shift is released or weakened so that the gear shift of the gear shift can be made possible by the execution of gear shift assist control by the first control unit. The second control unit, when a first abnormality, which is an abnormality of the gear shift assist control, occurs in a state in which manual mode operation or automatic mode operation is possible, switches to a retraction mode that permits gear shifting when the engagement between the dogs of the gear shift is released or weakened without using gear shift assist control, thereby improving the limp-home performance in the event of an abnormality when changing the gear of a dog-type gear shift.

[0010] Figure 1 is a block diagram showing the configuration of a gear shift control device according to an embodiment of the present invention. Figure 2 is a schematic cross-sectional view showing the configuration of a dog-type transmission or the like to which the gear shift control device according to an embodiment of the present invention is applied. Figure 3 is a diagram showing the operation of the gear shift control device according to an embodiment of the present invention in chronological order. Figure 4 is a flowchart showing the gear shift control process executed by the gear shift control device according to an embodiment of the present invention. Figure 5 is a flowchart showing the retraction mode operation process executed by the gear shift control device according to an embodiment of the present invention. Figure 6 is a flowchart showing the manual mode operation process executed by the gear shift control device according to an embodiment of the present invention.

[0011] Hereinafter, with reference to the drawings as appropriate, a gear change control device according to an embodiment of the present invention will be described in detail.

[0012] <Configuration of the Electronic Control Unit> The configuration of the ECU 1 equipped with a gear shift control unit 4 according to an embodiment of the present invention will be described in detail with reference to Figures 1 and 2.

[0013] The ECU (Electronic Control Unit) 1 is an electronic control unit that operates using a battery (not shown) as its power source.

[0014] The ECU 1 is mounted on a motorcycle that transmits the output of an internal combustion engine (engine) E, which acts as a drive source, to a drive wheel (not shown) via a crankshaft, clutch 51, and dog-type transmission T (not shown) as driving force, and performs control of the operating state of the engine E. Here, the clutch 51 is a centrifugal clutch provided between the engine E and the dog-type transmission T. When the centrifugal force increases to a certain extent, the centrifugal force causes the engine E-side component to receive the driving force from the engine E to come into contact with the drive wheel-side component due to dynamic friction, resulting in a partially clutched state where the engine E-side component and the drive wheel-side component slip. When the centrifugal force increases further, the engine E-side component and the drive wheel-side component come into complete contact due to static friction, resulting in a fully engaged clutch state where the clutch does not slip. Note that the clutch 51 is not limited to a centrifugal clutch; it may be an electronically controlled clutch or other clutch that operates without operator intervention. Furthermore, the drive source may be a combination of the engine E and an electric motor, or an electric motor alone, as needed.

[0015] Furthermore, the ECU 1 is connected to an accelerator position sensor 11, a water temperature sensor 12, a shift switch 13, a gear position sensor 14, a throttle position sensor 15, a crank angle sensor 16, a vehicle speed sensor 17, a brake stroke sensor 18, an IMU (inertial measurement unit) 19, a throttle valve 20, a spark plug 21, a fuel injection valve 22, a TCU (Transmission Control Unit) 23, and a notification unit 24. Two sets of accelerator position sensors 11 and throttle position sensors 15 are connected to the ECU 1. Note that in Figure 1, the description of one of the two sets of accelerator position sensors 11 and throttle position sensors 15 is omitted.

[0016] Specifically, the ECU 1 includes an A / D converter 2a, an A / D converter 2b, an A / D converter 2c, an A / D converter 2d, an A / D converter 2e, an A / D converter 2f, an A / D converter 2g, a communication circuit 2h, a waveform shaping circuit 3, a gear shift control device 4, a throttle motor drive circuit 5, a spark plug drive circuit 6, a fuel injection valve drive circuit 7, a communication circuit 8, and a notification control unit 9.

[0017] The A / D converter 2a converts an electrical signal, which exhibits a voltage corresponding to the amount of operation (accelerator opening) of an accelerator operating member such as an accelerator grip (not shown) of a motorcycle, output from the accelerator opening sensor 11 and input to the ECU 1, from analog to digital and outputs it to the transmission control device 4.

[0018] The A / D converter 2b converts an electrical signal, which exhibits a voltage corresponding to the temperature of the coolant flowing through the coolant passages in the side walls of the cylinder block of an engine (not shown), output from the water temperature sensor 12 and input to the ECU 1, from analog to digital and outputs it to the transmission control device 4.

[0019] The A / D converter 2c converts the electrical signal that instructs the change of gear position of the dog-type transmission T, which is output from the shift switch 13 and input to the ECU 1, from analog to digital and outputs it to the transmission control device 4.

[0020] The A / D converter 2d converts the electrical signal indicating the rotational position (rotation angle) of the shift drum 31 of the dog-type transmission T, which is output from the gear position sensor 14 and input to the ECU 1, from analog to digital and outputs it to the transmission control device 4.

[0021] The A / D converter 2e converts an electrical signal, which exhibits a voltage corresponding to the opening degree (throttle opening) of a throttle valve 20 (not shown) output from the throttle opening sensor 15 and input to the ECU 1, from analog to digital and outputs it to the transmission control device 4.

[0022] The A / D converter 2f converts the electrical signal, which is output from the vehicle speed sensor 17 and input to the ECU 1 and exhibits a voltage corresponding to the rotational speed of the front or rear wheel of the motorcycle, from analog to digital and outputs it to the transmission control device 4.

[0023] The A / D converter 2g converts the electrical signal, which exhibits a voltage corresponding to the amount of operation of a brake operating member such as a brake pedal and is output from the brake stroke sensor 18 to the ECU 1, from analog to digital and outputs it to the gear shift control device 4.

[0024] The communication circuit 2h is a CAN transceiver that receives electrical signals indicating acceleration, pitch angle, and roll angle, which change depending on the attitude of the motorcycle, output from the IMU 19 and input to the ECU 1, and outputs them to the gear shift control device 4.

[0025] The waveform shaping circuit 3 shapes the crank pulse signal, which is output from the crank angle sensor 16 and input to the ECU 1 and indicates the rotational position of the engine's crankshaft, to generate a digital pulse signal, and also outputs the generated digital pulse signal to the transmission control device 4.

[0026] The transmission control device 4 controls the operating state of the engine E by reading a control program stored in a ROM (not shown) and loading it into a RAM (not shown), and then executing the control program. At this time, the transmission control device 4 outputs a control signal that controls the operating state of the motorcycle based on the electrical signals input from the A / D converters 2a, 2b, 2c, 2d, 2e, 2f, 2g and waveform shaping circuit 3, and the pitch angle and roll angle indicated by the electrical signals input from the communication circuit 2h. This controls the operation of the throttle motor drive circuit 5 to control the drive of the throttle valve 20, the operation of the spark plug drive circuit 6 to control the drive of the spark plug 21, the operation of the fuel injection valve drive circuit 7 to control the drive of the fuel injection valve 22, the operation of the communication circuit 8 to communicate with the TCU 23, and the operation of the notification control unit 9 to activate the notification unit 24. Details of the configuration of the transmission control device 4 will be described later.

[0027] The throttle motor drive circuit 5 controls the drive of the throttle valve 20 by driving a throttle motor (not shown) according to a control signal input from the gear shift control device 4.

[0028] The spark plug drive circuit 6 controls the ignition operation of the engine by the spark plug 21, that is, a series of ignition operations such as starting, stopping, and restarting ignition, by controlling the electromotive force of a secondary coil (not shown) according to the control signal input from the transmission control device 4.

[0029] The fuel injector drive circuit 7 controls the fuel injection operation of the fuel injector 22, which injects fuel into the engine, by driving the fuel injector 22 according to the control signal input from the transmission control device 4, that is, a series of fuel injection operations such as starting, stopping, and restarting fuel injection.

[0030] The communication circuit 8 is a CAN transceiver that communicates with the TCU 23 according to the control signals input from the gear shift control device 4.

[0031] The notification control unit 9, in accordance with the control signal input from the gear shift control device 4, notifies that the gear position of the dog-type transmission T can be changed by lighting or flashing the notification unit 24, by generating sound from the notification unit 24, or by displaying an image on the notification unit 24. The notification unit 24 is equipped with a lamp, speaker, display, or a plurality of these.

[0032] <Configuration of the transmission control device> The configuration of the transmission control device 4 according to an embodiment of the present invention will be described in detail with reference to Figure 1.

[0033] The gear shift control device 4 is a CPU (Central Processing Unit) that operates using a battery (not shown) as its power source. The gear shift control device 4 enables manual mode operation, in which actuator A changes the gear position of the dog-type transmission T based on the operation of the motorcycle driver, or automatic mode operation, in which actuator A changes the gear position of the dog-type transmission T based on the driving state of the motorcycle.

[0034] Specifically, the transmission control device 4 controls the operation of the throttle motor drive circuit 5 to control the drive of the throttle valve 20 based on the throttle opening indicated by the voltage of the electrical signal input from the A / D converter 2e and the engine speed calculated based on the digital pulse signal input from the waveform shaping circuit 3, in response to an instruction to change the gear position of the dog-type transmission T indicated by the electrical signal input from the A / D converter 2c. This controls the drive of the throttle valve 20, thereby performing transmission assist control that changes the throttle opening so as to temporarily change the driving force of the engine E from a value corresponding to the accelerator opening. In addition, it communicates with the TCU 23 via the communication circuit 8 to control the drive of actuator A, thereby enabling manual mode operation in which the gear position of the dog-type transmission T is changed. Furthermore, the transmission control device 4 automatically performs transmission assist control according to the driving state of the motorcycle and communicates with the TCU 23 via the communication circuit 8 to control the drive of actuator A, thereby enabling automatic mode operation in which the gear position of the dog-type transmission T is changed. Here, the driving state of the motorcycle is determined, for example, by the throttle opening and engine speed. The driving state of the motorcycle may also be determined using parameters other than the throttle opening and engine speed. Furthermore, manual mode driving and automatic mode driving are switched by the transmission control device 4 when, for example, the driver operates a selector switch (not shown) provided on the motorcycle, and an electrical signal corresponding to this operation is input to the transmission control device 4.

[0035] The gear shift control device 4 comprises a first control unit 141 and a second control unit 142, which are shown in the figure as functional blocks for executing control programs, etc., and performs the gear shift control processing described later.

[0036] The first control unit 141, while the engine E and the dog-type transmission T are connected by the clutch 51, controls the operation of the throttle motor drive circuit 5 to control the drive of the throttle valve 20 based on the throttle opening indicated by the voltage of the electrical signal input from the A / D converter 2e and the engine speed calculated based on the digital pulse signal input from the waveform shaping circuit 3. This controls the operation of the throttle motor drive circuit 5 to temporarily change the output of the engine E so that the engagement between the dogs of the dog-type transmission T is released or weakened, thereby enabling a change in the gear of the dog-type transmission T.

[0037] The second control unit 142 determines whether it is necessary to change the gear position of the dog-type transmission T. If it determines that it is necessary to change the gear position of the dog-type transmission T, the second control unit 142 executes the gear shift assist control of the first control unit 141 to release or weaken the engagement between the dogs of the dog-type transmission T. In a state where it is possible to change the gear position of the dog-type transmission T, the second control unit 142 controls the operation of the communication circuit 8 to transmit an electrical signal corresponding to the target operation amount of actuator A to the TCU 23 via the communication circuit 8, thereby causing the TCU 23 to control the drive of actuator A and changing the gear position of the dog-type transmission T. When the second control unit 142 is in a state where manual mode operation or automatic mode operation is possible, and a first abnormality occurs in which the engagement of the dogs of the dog-type transmission T cannot be released by the shift assist control, it switches to a retraction mode that permits the change of the gear of the dog-type transmission T when the engagement of the dogs of the dog-type transmission T is released or weakened without the use of shift assist control, regardless of whether manual mode operation or automatic mode operation is selected by a mode switching switch (not shown), and executes the retraction mode operation process described later. Here, the first abnormality is a failure of the accelerator opening sensor 11, a failure of the throttle opening sensor 15, or a failure of the water temperature sensor, etc.

[0038] The second control unit 142, when a second abnormality less severe than the first abnormality occurs while manual mode operation or automatic mode operation is possible, switches to manual mode operation and executes the manual mode operation process described later. Here, the second abnormality is a failure of equipment used to obtain parameters used in the shift map used in automatic mode operation, such as engine speed, rider-requested torque (torque instructed by the driver), actual engine torque (actual torque of engine E), vehicle speed, vehicle acceleration, vehicle pitch angle, vehicle roll angle, or brake input. For example, it could be a failure of the vehicle speed sensor 17, a failure of the IMU 19, or a failure of the brake stroke sensor 18.

[0039] Furthermore, when the TCU23 connected to the ECU1 receives an electrical signal corresponding to the target operation amount of actuator A from the second control unit 142 via the communication circuit 8, it provides feedback control of the drive of actuator A by referring to the target operation amount of actuator A indicated by the received electrical signal and the operation amount of actuator A detected by a sensor (not shown), etc.

[0040] <Configuration and Operation of Dog-Type Transmission> The configuration and operation of a dog-type transmission T to which the transmission control device 4 according to an embodiment of the present invention is applied will be described in detail with reference to Figure 2.

[0041] The dog-type transmission T has a configuration in which a fixed gear 41 is mounted on the input shaft 46, and a free gear 42 and a sliding gear 43 are mounted on the drive shaft 47. The drum shaft 32 of the dog-type transmission T, that is, the shift drum 31, rotates when the actuator A is driven in response to the operation of the shift switch 13 by the driver or the driving state of the motorcycle.

[0042] The rotation of the shift drum 31 is transmitted to the shift fork 34, which is positioned in a cam groove (guide groove) 33 formed in the drum portion 31a, which is an enlarged diameter portion of the drum shaft 32, and moves along the guide groove 33. In response to this, the shift fork 34 moves, causing the slide transmission gear 43 to move in translation while mounted on the drive shaft 47. As the slide transmission gear 43 moves toward the free transmission gear 42 and approaches it, the dog teeth 44 and 45 become able to mesh. Here, although the reference numerals are omitted, pairs of free transmission gears and slide transmission gears that become able to mesh with each other's dog teeth 44 and 45 as the shift fork 34 moves are also provided in addition to the pair of free transmission gear 42 and slide transmission gear 43, and the dog-type transmission T has multiple gears. Furthermore, the diagram illustrates a configuration in which three guide grooves 33 are formed in the drum portion 31a.

[0043] When the clutch 51 is engaged and the dog teeth 44 and 45 are in contact and meshed, with the dog teeth 44 pushing against the dog teeth 45, the rotational force of the crankshaft (not shown) is transmitted to the drive wheels sequentially via the clutch 51, input shaft 46, fixed transmission gear 41, free transmission gear 42, sliding transmission gear 43, and drive shaft 47. Furthermore, when the clutch 51 is engaged and the dog teeth 44 and 45 are in contact and meshed, with one pushing against the other, it becomes difficult to move the sliding transmission gear 43 away from the free transmission gear 42 with the shift fork 34, making it difficult to shift to other gears. Note that the dog teeth 44 and 45 may have a configuration in which one is a concave tooth that accommodates the convex tooth of the other, in addition to the configuration in which they are convex teeth.

[0044] Further, adjacent to the drum portion 31a of the shift drum 31, a shift cam 35 is fixedly provided on the drum shaft 32, and the shift cam 35 rotates around the axis coaxial with the rotation shaft of the drum shaft 32 as the drum shaft 32 rotates. With respect to such a shift cam 35, a detent member 36 to which the elastic force of an elastic member 37 is applied as an urging force is abutted while being pressed. The outer peripheral edge of the shift cam 35 is provided with an uneven shape, and the detent member 36 is abutted against and pressed against the recess of the shift cam by the urging force of the elastic member 37, whereby the rotational position of the drum shaft 32 and thus the shift drum 31 is positioned and maintained so as not to move at a predetermined position (predetermined angle).

[0045] The dog-type transmission T having such a configuration is configured to bring the engine E and the drive wheels into a connected state by bringing the dogs into an engaged state where the dogs are engaged with each other, and to bring the engine E and the drive wheels into a disconnected state by bringing the dogs into a disengaged state where the engagement between the dogs is released. The dog clutch DC is provided, enabling gear shift while the clutch 51 is kept in a connected state.

[0046] In the dog clutch DC, there can be a driving state where the dog D1 on the engine E side presses the dog D2 on the drive wheel side and the engine E side transmits driving force, and a driven state where the dog D2 on the drive wheel side presses the dog D1 on the engine E side and the engine E side is driven by the driving force from the drive wheel side. Further, a predetermined gap (backlash) exists between the dog D1 and the dog D2. When switching between the driving state and the driven state as described above, the dog D1 and the dog D2 make relative rotation by the backlash amount, resulting in a transient cut-off state where no driving force is transmitted between the dog D1 on the engine E side and the dog D2 on the drive wheel side.

[0047] Here, the no-load line indicates an operating state of the engine E in which the driving force of the engine E is balanced with the resistance of the engine E (such as mechanical frictional force and viscoelastic force of lubricating oil). Specifically, the no-load line consists of characteristic data indicating the operating state of the engine E in which engagement between dogs of the dog-type transmission T can be released, with the engine speed and throttle opening as parameters, and is preset and stored in a memory not shown in the figure. Specifically, the no-load line defines a boundary of the operating state of the engine E where the engagement state between the dogs of the dog-type transmission T switches between the engagement state during deceleration and the engagement state during acceleration. The no-load line defines the relationship between the engine speed and the throttle opening in the aforementioned transient cut-off state where no driving force is transmitted between the dog D1 on the engine E side and the dog D2 on the drive wheel side: the state where the dogs that enter the cut-off state simply abut against each other without separating or pressing each other, and the state where the dogs gently press each other in a detachable state. Such a no-load line is preset in correspondence with the engine speed and the throttle opening.

[0048] Further, in a region above the no-load line, since the engine E drives the drive wheels, the dog D1 on the engine E side presses the dog D2 on the drive wheel side in the dog clutch DC of the dog-type transmission T. On the other hand, in a region below the no-load line, since the drive wheels drive the engine E, the dog D2 on the drive wheel side presses the dog D1 on the engine E side in the dog clutch DC of the dog-type transmission T. Note that the no-load line may be not only a simple line but also a region having a predetermined width including this line in an orthogonal coordinate system having the engine speed and the throttle opening as respective coordinate axes, and such a region may be treated equivalent to the no-load line.

[0049] <Shift Control Processing> The shift control processing executed by the shift control device 4 according to the embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

[0050] For example, when a motorcycle is running in third gear and no malfunction or other abnormality occurs, if the dog D1 on the engine E side pushes the dog D2 on the drive wheel side, resulting in the drive state shown in Figure 3(a) where the engine E side transmits driving force to the drive wheel, then the gear position of the dog-type transmission T cannot be changed by automatic mode operation unless the torque of the engine E is reduced. Also, under normal conditions where no abnormality occurs, the transmission control device 4 can operate in manual mode or automatic mode.

[0051] In this driving state, if a first abnormality occurs, which is an abnormality in the shift assist control that prevents the operation of changing the torque of the engine E, the shift control device 4 cannot disengage or weaken the engagement between the dogs of the dog-type transmission T by the shift assist control in the first control unit 141, and therefore cannot change the gear position of the dog-type transmission T in manual mode operation or automatic mode operation. At this time, the shift control device 4 switches to a retraction mode that permits changing the gear position of the dog-type transmission T when the engagement between the dogs of the dog-type transmission T is disengaged or weakened without the use of shift assist control.

[0052] After transitioning to the retraction mode, the transmission control device 4 controls the operation of the notification control unit 9 to notify the notification unit 24 that the engagement between the dogs of the dog-type transmission T has been released or weakened, thereby enabling a change in the gear position of the dog-type transmission T. This allows the motorcycle driver to clearly recognize that a change in the gear position of the dog-type transmission T is possible. Furthermore, the transmission control device 4 prohibits the execution of the gear shift assist control by the first control unit 141 when the first abnormality occurs. This prevents the gear shift assist control from being executed unintentionally when the first abnormality occurs. In addition, it is preferable to regulate the torque of the engine E by controlling the throttle opening to a value smaller than the value corresponding to the accelerator opening when the first abnormality occurs.

[0053] Furthermore, after transitioning to the retraction mode, if the engagement between the dogs of the dog-type transmission T shown in Figure 3(a) is not released or weakened, the transmission control device 4 will need to change the torque of the engine E. For example, when a motorcycle driver attempts to shift up from 3rd to 4th gear by operating the shift switch 13, the transmission control device 4 will not perform the shift up in manual mode or automatic mode. On the other hand, after transitioning to the retraction mode, if the engagement between the dogs of the dog-type transmission T shown in Figure 3(b) is released or weakened without the use of transmission assist control, the transmission control device 4 will not need to change the torque of the engine E, and will therefore permit a shift down from 3rd to 2nd gear. This state of release or weakening of the engagement between the dogs of the dog-type transmission T occurs, for example, when the throttle opening changes from a predetermined opening to a fully closed opening (0 degrees) or a nearby opening (predetermined opening > nearby opening) (a few degrees) due to the driver reducing the amount of operation of the accelerator operating member. This ensures limp-home functionality even in the event of a first abnormality that prevents the engine E from performing a torque change operation, by allowing the dog-type transmission T to change gears.

[0054] Here, the state in which the dogs of the dog-type transmission T are disengaged or weakened is the state in which the engine E is operating on the no-load line, which indicates an operating state in which the dogs of the dog-type transmission T can be disengaged, and the state in which the clutch 51 is disengaged. The state in which the clutch 51 is disengaged means the state in which the clutch 51 is completely disengaged and does not include the half-clutch state of the clutch 51.

[0055] On the other hand, if the first abnormality has not occurred, and a second abnormality less severe than the first abnormality has occurred in the motorcycle, the transmission control device 4 prohibits automatic mode operation and permits manual mode operation to change the gear position of the dog-type transmission T.

[0056] Next, the gear shift control process will be explained in more detail with reference to Figures 4 to 6.

[0057] The gear shift control process shown in Figure 4 begins when the ignition switch (not shown) of the motorcycle is turned on and the gear shift control device 4 is activated, and the gear shift control process proceeds to step S1. The gear shift control process shown in Figure 4 is repeatedly executed at predetermined control cycles while the motorcycle is started and the gear shift control device 4 is activated.

[0058] In step S1, the second control unit 142 of the gear shift control device 4 determines whether or not the first abnormality has occurred. If the determination shows that the first abnormality has occurred, the second control unit 142 proceeds to step S2 of the gear shift control process. On the other hand, if the first abnormality has not occurred, the second control unit 142 proceeds to step S3 of the gear shift control process.

[0059] In step S2, the second control unit 142 switches to the retraction mode and executes the retraction mode operation process. This completes step S2 and terminates the gear shift control process. Thus, if the first abnormality occurs, the system switches to the retraction mode and executes the retraction mode operation process, regardless of whether manual mode operation or automatic mode operation is selected by the mode switching switch (not shown).

[0060] In step S3, the second control unit 142 determines whether or not a second abnormality has occurred. If the determination shows that a second abnormality has occurred, the second control unit 142 proceeds to step S4 of the gear shift control process. On the other hand, if no second abnormality has occurred, the second control unit 142 proceeds to step S5 of the gear shift control process.

[0061] In step S4, the second control unit 142 executes manual mode operation processing. This completes step S4 and terminates the gear shift control processing. At this time, if the second abnormality occurs while manual mode operation is selected by the mode selector switch, the second control unit 142 prohibits automatic mode operation and maintains manual mode operation, executing manual mode operation processing. On the other hand, if the second abnormality occurs while automatic mode operation is selected by the mode selector switch, the second control unit 142 prohibits automatic mode operation and switches to manual mode operation, executing manual mode operation processing.

[0062] In step S5, the second control unit 142 determines whether manual mode operation is selected by the mode switching switch. If manual mode operation is selected, the second control unit 142 proceeds to step S4 for the gear shift control process. On the other hand, if manual mode operation is not selected, the second control unit 142 proceeds to step S6 for the gear shift control process.

[0063] In step S6, the second control unit 142 controls the vehicle to operate in automatic mode. This completes step S6, and the gear shift control process ends.

[0064] <Retraction Mode Operation Process> The retraction mode operation process performed by the transmission control device 4 according to the embodiment of the present invention will be described in detail with reference to Figure 5.

[0065] The escape mode operation process shown in Figure 5 is initiated when it is determined that a first abnormality has occurred in step S1 of the gear shift control process, and the escape mode operation process proceeds to step S21.

[0066] In step S21, the second control unit 142 prohibits the execution of the gear shift assist control. This completes step S21, and the retraction mode operation process proceeds to step S22.

[0067] In step S22, the second control unit 142 determines whether the operating state of the engine E is on the no-load line. In this case, if, for example, one of the two throttle opening sensors 15 fails, the second control unit 142 determines whether the operating state of the engine E is on the no-load line based on the throttle opening corresponding to the voltage of the electrical signal output from the other throttle opening sensor 15 and input to the ECU 1. If the determination shows that the operating state of the engine E is not on the no-load line, the second control unit 142 proceeds to step S23 for the retraction mode operation process. On the other hand, if the operating state of the engine E is on the no-load line, the second control unit 142 proceeds to step S28 for the retraction mode operation process.

[0068] In step S23, the second control unit 142 determines whether the engine speed is below a predetermined value because the clutch 51 is released and the transmission of power from the engine E to the drive wheels (not shown) is interrupted. If the determination shows that the engine speed is below the predetermined value, the second control unit 142 proceeds to step S24 for the retraction mode operation process. On the other hand, if the engine speed is greater than the predetermined value, the second control unit 142 terminates the retraction mode operation process.

[0069] In step S24, the second control unit 142 controls the notification control unit 9 to notify the driver that the vehicle can change gears via the notification unit 24. With this, the process of step S24 is completed, and the evacuation mode operation process proceeds to step S25.

[0070] In step S25, the second control unit 142 determines whether the gear is in first gear. If the determination shows that the gear is not in first gear, the second control unit 142 proceeds to step S26 for the retraction mode operation process. On the other hand, if the gear is in first gear, the second control unit 142 terminates the retraction mode operation process.

[0071] In step S26, the second control unit 142 communicates with the TCU 23 via the communication circuit 8 to control the drive of actuator A, thereby initiating a forced downshift by changing the gear position of the dog-type transmission T. By initiating a forced downshift, the second control unit 142, knowing that the clutch 51 has already been released and the transmission of power from the engine E to the drive wheels (not shown) has been cut off, and that the motorcycle is decelerating, forcibly downshifts in accordance with the speed of the motorcycle to automatically decelerate the motorcycle. With this, the process of step S26 is completed, and the evacuation mode operation process proceeds to step S27.

[0072] In step S27, the second control unit 142 transmits an electrical signal corresponding to the target operating amount of actuator A due to the downshift to the TCU 23 via the communication circuit 8. This completes step 27, and the retraction mode operation process ends.

[0073] In step S28, the second control unit 142 controls the notification control unit 9 to cause the notification unit 24 to notify the driver that the vehicle can be shifted. With this, the process of step S28 is completed, and the evacuation mode operation process proceeds to step S29.

[0074] In step S29, the second control unit 142 determines, based on the electrical signal output from the shift switch 13 and input to the ECU 1, whether or not the driver has instructed the driver to change gears by operating the shift switch 13. If the determination shows that the driver has instructed the driver to change gears by operating the shift switch 13, the second control unit 142 proceeds to step S30 for the retraction mode operation process. On the other hand, if the driver has not instructed the driver to change gears by operating the shift switch 13, the second control unit 142 terminates the retraction mode operation process.

[0075] In step S30, the second control unit 142 transmits an electrical signal to the TCU 23 via the communication circuit 8, corresponding to the target operating amount of actuator A due to the change in gear stage. This completes the process in step 27, and the retraction mode operation process ends.

[0076] <Manual Mode Operation Process> The manual mode operation process performed by the gear shift control device 4 according to the embodiment of the present invention will be described in detail with reference to Figure 6.

[0077] The manual mode operation process shown in Figure 6 is initiated when it is determined that a second abnormality has occurred in step S3 of the gear shift control process, and the manual mode operation process proceeds to step S41.

[0078] In step S41, the second control unit 142 determines, based on the electrical signal output from the shift switch 13 and input to the ECU 1, whether or not there was an instruction to change gears by operating the shift switch 13. If the determination shows that there was an instruction to change gears by operating the shift switch 13, the second control unit 142 proceeds to step S42 of the manual mode operation process. On the other hand, if there was no instruction to change gears by operating the shift switch 13, the second control unit 142 terminates the manual mode operation process.

[0079] In step S42, the first control unit 141 performs gear shift assist control. This completes step S42, and the manual mode operation process proceeds to step S43.

[0080] In step S43, the second control unit 142 transmits an electrical signal to the TCU 23 via the communication circuit 8, corresponding to the target operating amount of actuator A due to the change in gear position. This completes step 43, and the manual mode operation process ends.

[0081] As is clear from the above description, in the first aspect of the transmission control device 4 according to this embodiment, the transmission control device 4 is mounted on a motorcycle equipped with a dog-type transmission T having a plurality of gear stages and an actuator A for changing the gear stages of the dog-type transmission T, and enables manual mode operation in which the actuator A changes the gear stages of the dog-type transmission T based on the operation of the motorcycle driver, or automatic mode operation in which the actuator A changes the gear stages of the dog-type transmission T based on the driving state of the motorcycle, and includes a first control unit 141 that performs transmission assist control to temporarily change the output of the motorcycle's engine E so that the engagement of the dogs of the dog-type transmission T is released or weakened to enable the gear stages of the dog-type transmission T to be changed, and The system includes a second control unit 142 that enables the gear change of the dog-type transmission T by controlling the drive of actuator A when the engagement of the dogs of the dog-type transmission T is released or weakened by the execution of the gear assist control of control unit 141, thereby enabling the gear change of the dog-type transmission T. The second control unit 142, when a first abnormality, which is an abnormality of the gear assist control, occurs while manual mode operation or automatic mode operation is possible, switches to a retraction mode that permits the gear change of the dog-type transmission T when the engagement of the dogs of the dog-type transmission T is released or weakened without using gear assist control, thereby improving the limp-home capability in the event of an abnormality when changing the gear of the dog-type transmission T.

[0082] Furthermore, in the second aspect of the transmission control device 4 according to this embodiment, in addition to the first aspect, the state in which the engagement between the dogs of the dog-type transmission T is released or weakened is a state in which the operating state of the engine E is on the no-load line, which indicates an operating state in which the engagement between the dogs of the dog-type transmission T can be released. Therefore, when the system transitions to the retraction mode and the operating state of the engine E is on the no-load line, it is possible to allow a change in the gear position of the dog-type transmission T.

[0083] Furthermore, in a third aspect of the transmission control device 4 according to this embodiment, in addition to the first or second aspect, the motorcycle has a clutch 51 which is a centrifugal clutch between the engine E and the dog-type transmission T, and when the engagement between the dogs of the dog-type transmission T is released or weakened, the centrifugal clutch is released, so it is possible to allow a change in the gear of the dog-type transmission T when it transitions to the retraction mode and the centrifugal clutch is released.

[0084] Furthermore, in the fourth aspect of the transmission control device 4 according to this embodiment, in addition to any of the first to third aspects, the second control unit 142 notifies that it is possible to change the gear of the dog-type transmission T when the engagement between the dogs of the dog-type transmission T is released or weakened, thereby making it clear to the driver that it is possible to change the gear of the dog-type transmission T.

[0085] Furthermore, in the fifth aspect of the transmission control device 4 according to this embodiment, in addition to any of the first to fourth aspects, the first abnormality is an abnormality in which the dogs of the dog-type transmission T cannot be disengaged by the transmission assist control. Therefore, the limp-home performance when an abnormality occurs in which the dogs of the dog-type transmission T cannot be disengaged by the transmission assist control can be improved.

[0086] Furthermore, in the sixth aspect of the transmission control device 4 according to this embodiment, in addition to any of the first to fifth aspects, if the first abnormality occurs, the execution of the transmission assist control by the first control unit 141 is prohibited. Therefore, it is possible to prevent the transmission assist control from being executed when the first abnormality occurs.

[0087] Furthermore, in the seventh aspect of the transmission control device 4 according to this embodiment, in addition to any of the first to sixth aspects, the second control unit 142 prohibits automatic mode operation and allows manual mode operation to change the gear position of the dog-type transmission T when the first abnormality has not occurred and a second abnormality, which is less severe than the first abnormality, has occurred in the motorcycle. Therefore, the limp-home capability in the event of a second abnormality can be improved.

[0088] The present invention is not limited to the above-described embodiments in terms of the type, shape, arrangement, number, etc. of the components, and it is of course possible to modify them as appropriate without departing from the spirit of the invention, such as by appropriately substituting the components with those that produce equivalent effects.

[0089] Specifically, in the above embodiment, in manual mode operation, the gear position of the dog-type transmission T was changed by driving actuator A through the operation of the driver's shift switch 13. In addition to this, the microcontroller may also perform gear shift control by an automatic clutch that connects or disconnects the engine E and the dog-type transmission T.

[0090] As described above, the present invention makes it possible to change gears by the transmission according to the state of the dog-type transmission, thereby improving the limp-home capability in abnormal situations. Due to its general-purpose and universal nature, it is expected to be widely applicable to transmission control devices installed in motorcycles.

[0091] A...Actuator D1...Dog D2...Dog DC...Dog clutch E...Engine T...Dog type transmission 1...ECU 4...Transmission control unit 5...Throttle motor drive circuit 6...Spark plug drive circuit 7...Fuel injector drive circuit 8...Communication circuit 9...Notification control unit 11...Accelerator position sensor 12...Water temperature sensor 13...Shift switch 14...Gear position sensor 15...Throttle position sensor 16...Crank angle sensor 17...Vehicle speed sensor 18...Brake stroke sensor 19...IMU 20...Throttle valve 21...Spark plug 22...Fuel injector 23...TCU 24...Notification unit 41...Fixed transmission gear 42...Free transmission gear 43...Slide transmission gear 44...Dog teeth 45...Dog teeth 51...Clutch 141...First control unit 142...Second control unit

Claims

1. A gear control device mounted on a motorcycle equipped with a dog-type transmission having multiple gear stages and an actuator for changing the gear stages of the transmission, which enables manual mode operation in which the actuator changes the gear stages of the transmission based on the operation of the motorcycle driver, or automatic mode operation in which the actuator changes the gear stages of the transmission based on the driving state of the motorcycle, comprising: a first control unit that performs gear assist control by temporarily changing the output of the drive source of the motorcycle so that the engagement of the dogs of the transmission is released or weakened so that the gear stages of the transmission can be changed; and a second control unit that enables the gear stages of the transmission to be changed by controlling the drive of the actuator when the engagement of the dogs of the transmission is released or weakened so that the gear stages of the transmission can be changed as a result of the execution of the gear assist control by the first control unit, wherein the second control unit A gear shift control device characterized in that, when a first abnormality, which is an abnormality in the gear shift assist control, occurs while the manual mode operation or the automatic mode operation is possible, the device transitions to a retraction mode that permits a change in the gear position of the transmission when the engagement between the dogs of the transmission is released or weakened without the gear shift assist control.

2. The gear control device according to claim 1, characterized in that the state in which the engagement between the dogs of the transmission is disengaged or weakened is a state in which the operating state of the drive source is on a no-load line indicating an operating state in which the engagement between the dogs of the transmission can be disengaged.

3. The transmission control device according to claim 1, wherein the motorcycle has a centrifugal clutch between the drive source and the transmission, and the state in which the engagement between the dogs of the transmission is disengaged or weakened is the state in which the centrifugal clutch is disengaged.

4. The gear control device according to claim 2 or 3, characterized in that the second control unit notifies that it is possible to change the gear position of the transmission when the engagement between the dogs of the transmission is disengaged or weakened.

5. The gear shift control device according to claim 1, characterized in that the first abnormality is an abnormality in which the gear shift assist control cannot disengage the engagement between the dogs of the gear shift.

6. The gear shift control device according to claim 5, characterized in that, if the first abnormality occurs, the execution of the gear shift assist control by the first control unit is prohibited.

7. The transmission control device according to claim 1, characterized in that the second control unit prohibits the automatic mode operation and permits the change of the transmission gear position by the manual mode operation when the first abnormality has not occurred and a second abnormality less severe than the first abnormality has occurred in the motorcycle.

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