JP7776346B2 - Gear transmission control device, vehicle, and control method - Google Patents

Description

This disclosure relates to a control device, vehicle, and control method for a gear transmission that changes gears using the power of a shift actuator.

Patent Document 1 discloses a gear change control device equipped with an electric motor that rotates a shift drum and a control unit that controls the electric motor. A protrusion on a shift fork engages with a groove formed on the outer peripheral surface of the shift drum. When the shift drum is rotated by the electric motor, the dogs are displaced along with the shift fork, disengaging the currently engaged dog clutch and engaging the next dog clutch.

JP 2010-78117 A

In a dog clutch gear transmission, it is desirable for the dogs to engage smoothly.

The present disclosure therefore aims to provide a gear transmission control device, vehicle, and control method that can achieve smooth engagement of the dogs in a dog clutch-type gear transmission.

In order to solve the above-mentioned problems, one aspect of the present disclosure provides a gear transmission control device that includes an input shaft, an output shaft, multiple sets of gear pairs, each including a gear that is coaxial with the input shaft and a gear that is coaxial with the output shaft, a shift actuator that moves multiple engagement portions that can engage with the multiple sets of gear pairs and places one of the multiple sets of gear pairs that is engaged with an engagement portion into a power transmission state, and a sensor that detects the position of the engagement portions. The control device includes a processing circuit that, upon receiving a shift command to shift a gear position, determines the engagement timing for starting engagement between the gear and the engagement portions based on the difference between the rotational speed of the gear and the rotational speed of the engagement portions, and controls the shift actuator so that the position detected by the sensor is maintained within a disengagement range in which the multiple engagement portions do not engage with any of the multiple sets of gear pairs until the engagement timing is reached.

A vehicle according to one aspect of the present disclosure is a vehicle that travels when operated by a driver, and includes a vehicle body equipped with a driving source, the gear transmission supported on the vehicle body, and the control device that controls the gear transmission.

A gear transmission control method according to one aspect of the present disclosure is a gear transmission control method for controlling a shift actuator that moves an engagement portion that can engage with a transmission gear to shift gear stages. When a shift command to shift gear stages is received, the method determines the engagement timing for initiating engagement between the transmission gear and the engagement portion based on the difference between the rotation speed of the transmission gear and the rotation speed of the engagement portion, and maintains the position of the engagement portion within a disengagement range in which the engagement portion does not engage with the transmission gear until the engagement timing is reached.

This disclosure provides a gear transmission control device, vehicle, and control method that can achieve smooth engagement of the dogs in a dog clutch-type gear transmission.

1 is a schematic diagram of a vehicle power system equipped with a gear transmission control device according to an embodiment; FIG. 2 is a side view of a change mechanism of the gear transmission shown in FIG. 1 . 4 is a flowchart showing an example of the flow of a gear shift process performed by the control device. FIG. 10 is a schematic diagram showing an example of the positional relationship between a change cam, a positioning roller, and a shift pawl in a first gear position. FIG. 10 is a schematic diagram showing an example of the positional relationship between a dog and a speed change gear in a first speed change stage. FIG. 10 is a schematic diagram showing an example of the positional relationship between a change cam, a positioning roller, and a shift pawl during standby control. FIG. 10 is a schematic diagram showing an example of the positional relationship between a dog and a transmission gear during standby control. FIG. 10 is a schematic diagram showing an example of the positional relationship between a change cam, a positioning roller, and a shift pawl in a second gear position. FIG. 10 is a schematic diagram showing an example of the positional relationship between the dog and the speed change gear in a second speed change stage. 10 is a schematic diagram showing another example of the positional relationship between the change cam, the positioning roller, and the shift pawl during standby control. FIG.

The following describes the embodiment with reference to the drawings.

<Gear transmission configuration>
1 is a schematic diagram of a power system of a vehicle 1 equipped with a control device 40 for a gear transmission 10 according to one embodiment. The vehicle 1 is, for example, a straddle-type vehicle (e.g., a motorcycle). In this embodiment, the vehicle 1 is exemplified as a hybrid vehicle equipped with two driving sources: an engine 2, which is an internal combustion engine serving as a first prime mover, and a drive motor 3, which is an electric motor serving as a second prime mover.

The crankshaft 2a of the engine 2 is connected to the gear transmission 10 via a primary gear 4 and a main clutch 5 (e.g., a friction clutch). The main clutch 5 is driven by a clutch actuator 5a to connect and disconnect the power transmission path from the crankshaft 2a to the input shaft 11. The motor drive shaft 3a of the drive motor 3 is connected to the gear transmission 10 via a power transmission mechanism 6 (e.g., a chain and sprocket mechanism, a belt and pulley mechanism, a drive shaft and gear mechanism, etc.). The gear transmission 10 is connected to the drive wheels 8 via an output transmission mechanism 7 (e.g., a chain and sprocket mechanism, a belt and pulley mechanism, a drive shaft and gear mechanism, etc.).

The gear transmission 10 is a dog clutch type transmission. The gear transmission 10 includes an input shaft 11, an output shaft 12, multiple sets of transmission gear pairs 13 corresponding to multiple gear stages, and multiple dogs 14 (corresponding to engagement portions) corresponding to the multiple sets of transmission gear pairs 13. The multiple dogs 14 select one of the multiple sets of transmission gear pairs 13 that has the desired reduction ratio.

The input shaft 11 can transmit the driving force of at least one of the engine 2 and drive motor 3, which are driving sources for traveling. When the main clutch 5 is engaged, power is input to the input shaft 11 from only the engine 2, or from both the engine 2 and drive motor 3. When the main clutch 5 is disengaged, power is input to the input shaft 11 from only the drive motor 3. The output shaft 12 is arranged parallel to the input shaft 11. Hereinafter, the direction parallel to the input shaft 11 and the output shaft 12 will be referred to as the "axial direction." Multiple sets of transmission gear pairs 13 are aligned in the axial direction. The multiple sets of transmission gear pairs 13 have different reduction ratios. The reduction ratio can also be referred to as the gear ratio or the transmission ratio.

Each transmission gear pair 13 includes one transmission gear 13 coaxially mounted on the input shaft 11 and one transmission gear 13 coaxially mounted on the output shaft 12. Of the two transmission gears 13 included in each transmission gear pair 13, one transmission gear 13 is a gear (hereinafter referred to as the "co-rotating gear") 13a that rotates integrally with the input shaft 11 or output shaft 12, which is coaxial with that gear. For example, the co-rotating gear 13a is assembled to the input shaft 11 or output shaft 12 by spline fitting. Of the two transmission gears 13 included in each transmission gear pair 13, the other transmission gear 13 is a gear (hereinafter referred to as the "idling gear") 13b that can rotate relative to the input shaft 11 or output shaft 12, which is coaxial with that gear.

The co-rotating gear 13a and the idling gear 13b in each transmission gear pair 13 are constantly meshed. In this embodiment, the co-rotating gears 13a and the idling gears 13b are arranged alternately in the axial direction on the input shaft 11. Similarly, the idling gears 13b and the co-rotating gears 13a are arranged alternately in the axial direction on the output shaft 12.

Several co-rotating gears 13a are integral with dogs 14, and together with the dogs 14, form dog gears 15. In the dog gears 15, the dogs 14 are arranged so as to protrude axially from the axial end faces of the co-rotating gears 13a. For example, the dogs 14 are composed of multiple protrusions arranged at predetermined intervals around the circumferential direction of the co-rotating gear 13a on the end faces of the co-rotating gears 13a. Note that in Figure 2, to avoid complexity, not all of the co-rotating gears, idling gears, and dog gears are labeled with reference numerals, but only some of them.

The dog gear 15 is movable axially relative to the input shaft 11 or the output shaft 12. The idle gear 13b, which is axially opposed to the dog gear 15, has an accommodation space S. The accommodation space S is open on the axial side where the dog 14 is located so that the moving dog 14 can enter. In this embodiment, the accommodation space S is formed by multiple protrusions arranged at predetermined intervals around the circumferential direction of the idle gear 13b on the axial end face of the idle gear 13b. In other words, the accommodation space S is the space formed between adjacent protrusions around the circumferential direction of the idle gear 13b on the end face of the idle gear 13b. Note that the accommodation space S may also be a hole formed in the axial end face of the idle gear 13b. In other words, the accommodation space S may or may not be open radially of the idle gear 13b.

A shift fork 22, which moves to change gears, is slidably supported on a support shaft 21 arranged parallel to the input shaft 11 and output shaft 12. The tip of the shift fork 22 is connected to a dog gear 15. The base end of the shift fork 22 is fitted into a guide groove G of the shift drum 23. When the shift drum 23 rotates, the shift fork 22, guided by the guide groove G, slides the corresponding dog gear 15 along the input shaft 11 or output shaft 12. The dog gear 15 slides and moves. The dog 14 corresponding to a certain gear enters the accommodation space S of the gear pair 13 corresponding to that gear, thereby placing the gear pair 13 corresponding to that gear in a power transmission state.

The gear transmission 10 has a gear position sensor 31 (corresponding to the sensor), a shift actuator 32, and a change mechanism 33.

The gear position sensor 31 detects the rotation angle of the shift drum 23. The rotation angle of the shift drum 23 makes it possible to detect which of the multiple transmission gear pairs 13 of the gear transmission 10 is in a selected state, i.e., which gear position it is in. A detected angle signal indicating the rotation angle detected by the gear position sensor 31 is sent to the control device 40 of the vehicle 1.

The control device 40 controls the engine 2, drive motor 3, clutch actuator 5a, and shift actuator 32. The control device 40 has a processor 40a and memory 40b. The processor 40a controls the engine 2, drive motor 3, clutch actuator 5a, and shift actuator 32 by executing programs stored in memory 40b. The processor 40a is an example of a processing circuit. The control device 40 controls the shift actuator 32 in response to a shift command sent from the shift switch 41.

The shift switch 41 is used to change the gear position, or shift stage, of the gear transmission 10. The shift switch 41 is located, for example, on the grip of the steering wheel of the vehicle 1 so that it can be manually operated by the driver. The shift switch 41 sends a shift command to the control device 40 in response to manual operation by the driver. For example, the shift command is an upshift command or a downshift command. An upshift command is a command to increase the gear stage of the gear transmission 10. More specifically, an upshift command is a command to increase the reduction ratio of the output shaft 12 relative to the input shaft 11. A downshift command is a command to decrease the gear stage of the gear transmission 10. More specifically, a downshift command is a command to decrease the reduction ratio of the output shaft 12 relative to the input shaft 11.

The shift actuator 32 is controlled by the control device 40 and generates power to rotate the shift drum 23. The shift actuator 32 is, for example, an electric motor that can rotate forward and backward. The power from the shift actuator 32 is transmitted to the shift drum 23 via the change mechanism 33.

Figure 2 is a side view of the change mechanism 33 as seen in the direction in which the axis X1 of the shift drum 23 extends. In Figure 2, the change mechanism 33 is located on the front side, and the shift drum 23 is located on the back side. The change mechanism 33 operates using the rotational power of the shift actuator 32, and intermittently rotates the shift drum 23. The change mechanism 33 includes a change shaft 51, a change lever 52, a return spring 53, a change cam 54, a stopper rod 55, and a position lever 56.

The axis X2 of the change shaft 51 is arranged parallel to the axis X1 of the shift drum 23. The shift actuator 32 is attached to the first end of the change shaft 51 (see Figure 1), and the change lever 52 is attached to the second end of the change shaft 51. The change shaft 51 receives power from the shift actuator 32 and rotates around its axis X2.

The change lever 52 is fixed to the change shaft 51. The change lever 52 comprises a lever body 61, a slider 62, a rivet 63, and a slider spring 64. The lever body 61 and the slider 62 are plate-shaped members that are perpendicular to a line parallel to the axis X2.

The lever body 61 is fixed to the change shaft 51, for example, by welding. The lever body 61 rotates together with the change shaft 51 around the axis X2. The lever body 61 has a base 71 fixed to the change shaft 51 and a slider support portion 72 that protrudes from the base 71 in a radial direction perpendicular to the axis X2. The base 71 has a biased portion 71a and a stopper hole 71b.

The return spring 53 is disposed on one axial side of the base 71, and the biased portion 71a protrudes from the main surface of the base 71 toward the return spring 53 (toward the back of the page in the example of Figure 2). The biased portion 71a abuts against the return spring 53 and is subjected to a biasing force from the return spring 53. The stopper hole 71b has an oval shape that extends circumferentially around the axis X2. The slider support portion 72 has a pin hole 72a through which the rivet 63 passes.

The slider 62 is slidably placed on the slider support portion 72. The slider 62 has a guide hole 75 through which the shank of the rivet 63 is inserted. The guide hole 75 extends in the radial direction so as to guide the shank of the rivet 63 in the radial direction. The rivet 63 passes through the guide hole 75 of the slider 62 and is fastened into the pin hole 72a of the lever body 61. Note that the object inserted into the guide hole 75 of the slider 62 is not limited to a rivet; any object that functions as a guide pin (for example, a pin or a retaining device) may be used.

The slider 62 has a pair of shift pawls 66 distal from the axis X2, i.e., radially outward from the change shaft 51. The pair of shift pawls 66 are formed by bending the tip of the slider 62 toward the change cam 54. The pair of shift pawls 66 are spaced apart in a direction perpendicular to the direction from the axis X2 toward the slider 62. When viewed from the direction of the axis X2, the pair of shift pawls 66 have a symmetrical shape with respect to the imaginary line extending radially and passing through the midpoint between the pair of shift pawls 66.

The slider spring 64 biases the slider 62 in a direction that brings the slider 62 closer to the axis X2. One end of the slider spring 64 is attached to the spring support portion 62a of the slider 62. For example, the slider spring 64 is positioned on the opposite side of the slider 62 from the side where the change cam 54 is located, and the spring support portion 62a protrudes from the main surface of the slider 62 toward the slider spring 64 (toward the front of the page in the example of Figure 2). The other end of the slider spring 64 is attached to a ring that is fitted onto the change shaft 51 so as to be rotatable relative to the change shaft 51, or to the base 71 of the lever body 61. When the slider 62 slides radially outward (in other words, away from the axis X2) relative to the lever body 61, the slider spring 64 applies a biasing force that returns the slider 62 radially inward (in other words, toward the direction away from the axis X2). The slider spring 64 is shown in simplified form in Figure 2.

The return spring 53 is a torsion spring fitted onto the change shaft 51. One end and the other end of the return spring 53 sandwich the biased portion 71a of the lever body 61 in the circumferential direction around the axis X2. A stopper rod 55 passes between the one end and the other end of the return spring 53. The return spring 53 biases the change lever 52 so that the phase angle of the change lever 52 around the axis X2 is maintained at a predetermined lever reference angle.

The change cam 54 rotates integrally with the shift drum 23 around the rotation axis X1 of the shift drum 23. The change cam 54 is fixed to the end face of the shift drum 23 in the direction of the axis X1 and faces the change lever 52. The change cam 54 has a disk portion 81 and multiple passive convex portions 82.

The disc portion 81 is arranged perpendicular to the axis X1 of the shift drum 23. A plurality of positioning valleys 83 are formed on the outer peripheral surface (which may also be referred to as the outer peripheral edge) of the disc portion 81 at intervals in the circumferential direction around the axis X1, and a peak 84 is formed between two adjacent valleys 83 in the circumferential direction. In this embodiment, the plurality of valleys 83 are arranged at equal intervals in the circumferential direction around the axis X1, and the plurality of peaks 84 are arranged at equal intervals in the circumferential direction around the axis X1. The number of valleys 83 is the same as the number of gears in the gear transmission 10 (six in this example). In this embodiment, the outer peripheral surface of the disc portion 81 has repeated unevenness formed thereon, and the unevenness has a smooth curved shape.

The multiple passive protrusions 82 protrude from the surface of the disc portion 81 facing the change lever 52. The multiple passive protrusions 82 are arranged at equal intervals in the circumferential direction around the axis X1. The number of passive protrusions 82 is the same as the number of gears in the gear transmission 10. The position of the passive protrusions 82 in the direction of the axis X1 overlaps with the position of the shift pawl 66 in the direction of the axis X1. When the shift pawl 66 rotates around the axis X2, one or more of the multiple passive protrusions 82 abuts against the shift pawl 66.

The stopper rod 55 is inserted into the stopper hole 71b of the lever body 61 with some play in the rotational direction of the change lever 52. The stopper rod 55 is fixed to the side wall of the case of the gear transmission 10 and protrudes from that side wall toward the lever body 61.

The position lever 56 has a positioning arm 91, a positioning roller 92, and a positioning spring 93. The positioning arm 91 is rotatable around a straight line X3 that passes through its base end 91a and is parallel to the axis X2. The base end 91a of the positioning arm 91 is rotatably supported on the side wall of the case of the gear transmission 10. A positioning roller 92 is rotatably attached to the tip end 91b of the positioning arm 91. The positioning roller 92 faces the outer peripheral surface of the change cam 54. The positioning spring 93 biases the positioning arm 91 so as to press the positioning roller 92 against the outer peripheral surface of the change cam 54. The biasing force of the positioning spring 93 positions the positioning roller 92 so that it fits into the valley 83 on the outer peripheral surface of the change cam 54. As a result, the change cam 54 is positioned so that its phase angle around the axis X1 corresponds to the gear corresponding to the valley 83 into which the positioning roller 92 fits.

<Gear shifting process>
Fig. 3 is a flowchart showing an example of the flow of the gear shifting process by the control device 40 when the processor 40a acquires a shift command to shift from the current gear to the next gear. The flow of the gear shifting process in Fig. 3 will be explained below with reference to Figs. 4 to 9 as appropriate. For convenience, in this specification, the current gear will be referred to as the first gear, the dog 14 corresponding to the first gear will be referred to as the first dog 14a (corresponding to the first engagement portion), and the transmission gear 13 corresponding to the first gear and engageable with the first dog 14a will be referred to as the first gear (or first transmission gear, current gear, or pre-transmission gear) 13b1. In addition, the next gear stage after the dog 14 shifts from the current gear stage based on a shift command will be referred to as the second gear stage, the dog 14 corresponding to the second gear stage will be referred to as the second dog 14b (corresponding to the second engagement portion), and the gear 13 corresponding to the second gear stage that can engage with the second dog 14b will be referred to as the second gear (or second gear, next gear, or post gear) 13b2.

(First gear selected)
First, with reference to Figures 4 and 5, a state in which the first gear is selected will be described. Figure 4 is a schematic diagram showing an example of the positional relationship between the change cam 54, positioning roller 92, and shift pawl 66 in the first gear. The shift pawl 66 is indicated by a two-dot chain line. The biasing force of the positioning spring 93 (see Figure 2) causes the positioning arm 91 to press the positioning roller 92 against the outer peripheral surface of the change cam 54, causing the positioning roller 92 to fit into the valley portion 83 corresponding to the first gear. Hereinafter, the valley portion 83 corresponding to the first gear will be referred to as the first valley portion 83a, and the valley portion 83 corresponding to the next gear, the second gear, will be referred to as the second valley portion 83b. The pair of shift pawls 66 are positioned so as to sandwich two adjacent passive convex portions 82 of the change cam 54. That is, the shift pawls 66 face the passive convex portions 82 in the circumferential direction around the axis X1.

The rotation angle θ of the shift drum 23, i.e., the rotation angle θ detected by the gear position sensor 31, is an angle corresponding to the first gear. Note that in FIG. 4 and the later-described FIGS. 6, 8, and 10, the passive convex portion 82 that contacts the shift pawl 66 during the shift from first gear to second gear is designated by the reference symbol 82a, and the rotation angle θ detected by the gear position sensor 31 is represented as the rotation angle from the position of the passive convex portion 82a in first gear. In other words, in FIG. 4, which shows the first gear, the shift drum 23 and change cam 54 are positioned where the rotation angle θ is 0°.

Figure 5 is a schematic diagram showing an example of the positional relationship between the dog 14 and the transmission gear 13 in the first gear position. As shown in Figure 5, the transmission gear 13, which has an accommodation space S, has a first surface 16a and a second surface 16b that define the accommodation space S in the circumferential direction of the transmission gear 13. The first surface 16a is the surface against which the dog 14 inserted into the accommodation space S abuts when transmitting torque to the output shaft 12 in a predetermined positive direction. The second surface 16b is the surface against which the dog 14 inserted into the accommodation space S abuts when transmitting torque to the output shaft 12 in the negative direction, opposite to the positive direction.

In Figure 5, the axial direction and the positive direction are indicated by arrows. In this specification, the positive direction refers to the direction in which torque is generated by the input shaft 11 and the output shaft 12, accelerating the output shaft 12 as the vehicle 1 moves forward. That is, the first surface 16a is the surface against which the dog 14 inserted into the storage space S abuts when accelerating the rotation of the output shaft 12, and the second surface 16b is the surface against which the dog 14 inserted into the storage space S abuts when decelerating the rotation of the output shaft 12. In particular, in this example, the first surface 16a is the surface against which the dog 14 inserted into the storage space S abuts when the vehicle 1 is accelerating forward, and the second surface 16b is the surface against which the dog 14 inserted into the storage space S abuts when the vehicle 1 is decelerating.

As shown in FIG. 5, when the first dog 14a abuts against the first surface 16a of the first gear 13b1, the first gear 13b1 rotates together with the first dog 14a. In this way, the transmission gear pair 13 with which the first dog 14a is engaged transmits the torque of the input shaft 11 to the output shaft 12.

(dog removal control)
3, when the control device 40 receives a shift command from the shift switch 41 to shift from the first gear to the second gear, the control device 40 executes dog-disengagement control (step S1). The dog-disengagement control may also be referred to as disengagement control.

Dog disengagement control is a control performed on the shift actuator 32 to disengage the first dog 14a from the accommodation space S of the first gear 13b1. Specifically, the memory 40b pre-stores information indicating the correspondence between the rotation angle θ and whether or not the dog 14 of each gear is engaged with the gear 13 (in other words, whether or not the dog is in the accommodation space). During dog disengagement control, the control device 40 controls the shift actuator 32 so that the rotation angle θ detected by the gear position sensor 31 moves from the first engagement angle range R1 (corresponding to the first engagement range) to the non-engagement angle range R0 (corresponding to the non-engagement range).

The first engagement angle range R1 is the range of rotational angle θ in which the first gear 13b1 and the first dog 14a are engaged. The non-engagement angle range R0 is the range of rotational angle θ in which the first dog 14a is not engaged with the first gear 13b1 and the second dog 14b is not engaged with the second gear 13b2. In other words, the non-engagement angle range R0 is the range of rotational angle θ in which none of the transmission gear pairs 13 of the gear transmission 10 is selected.

In other words, as shown in FIG. 6, by controlling the shift actuator 32 to rotate the shift pawl 66 about axis X2, the shift pawl 66 rotates the passive convex portion 82a about axis X1. As a result, as shown in FIG. 7, none of the transmission gear pairs 13 of the gear transmission 10 are engaged with the dogs 14, i.e., they are in a disengaged state. In this disengaged state, torque transmission between the input shaft 11 and the output shaft 12 is interrupted. Note that in FIG. 6, only the shift pawl 66 of the pair of shift pawls 66 that is in contact with the passive convex portion 82a is shown by a two-dot chain line. Also, in FIGS. 6, 8, and 10, reference numerals not necessary for explanation have been omitted for clarity.

(Standby control and synchronization control)
After the rotation angle θ has entered the non-engagement angle range R0 as a result of the execution of the dog disengagement control, the control device 40 executes standby control (step S2) and synchronization control (step S3).

Standby control is a control performed on the shift actuator 32 that maintains the rotation angle θ within the non-engagement angle range R0 until the dog engagement timing (corresponding to the engagement timing) determined by the control device 40 arrives. In other words, standby control waits for the second dog 14b to enter the accommodation space S of the second gear 13b2 until the difference in rotation speed between the second dog 14b and the second gear 13b2 becomes small to a certain extent (until it reaches a set value) through synchronization control, which will be described later. Note that rotation speed refers to the speed (number of times) at which an object rotates per unit time. Rotation speed can also be referred to as rotational speed or angular velocity.

Synchronization control is performed on the prime mover (in this example, at least one of the engine 2 and drive motor 3) that drives the input shaft 11, and is control that brings one of the rotation speeds of the second dog 14b and the second gear 13b2 closer to the other. By performing synchronization control before inserting the second dog 14b into the accommodation space S of the second gear 13b2, the difference in rotation speed between the second dog 14b and the second gear 13b2 is reduced, allowing the second dog 14b to smoothly engage with the second gear 13b2.

Explained in more detail, synchronous control is control that aligns the input side of the second dog 14b and second gear 13b2 with the output side. For example, when the second dog 14b, which rotates integrally with the input shaft 11, is engaged with the second gear 13b2 mounted on the input shaft 11, the synchronous control refers to control that brings the rotation speed of the second dog 14b closer to the rotation speed of the second gear 13b2. Also, when the second dog 14b, which rotates integrally with the output shaft 12, is engaged with the second gear 13b2 mounted on the output shaft 12, the synchronous control refers to control that brings the rotation speed of the second gear 13b2 closer to the rotation speed of the second dog 14b.

Note that the timing for starting synchronous control does not have to be after the end of dog-disengagement control; for example, it may be before the start of dog-disengagement control or simultaneously with the start of dog-disengagement control.

In step S2, the control device 40 determines the timing for engaging the second gear 13b2 with the second dog 14b based on the difference between the rotation speed of the second gear 13b2 and the rotation speed of the second dog 14b. The control device 40 controls the shift actuator 32 so that the rotation angle θ is maintained within the non-engagement angle range R0 until the timing for engaging the second gear 13b2.

In this embodiment, the control device 40 determines the timing at which the difference between the rotation speed of the second gear 13b2 and the rotation speed of the second dog 14b becomes equal to or less than a predetermined value as the dog engagement timing.

The rotation speed of the input side member, either the second gear 13b2 or the second dog 14b, is obtained from the rotation speed of the input shaft 11 or a parameter corresponding thereto. A first rotation speed sensor mounted on the vehicle 1 detects the rotation speed of the input shaft 11 or a parameter corresponding thereto and sends it to the control device 40. Examples of the first rotation speed sensor include a rotation speed sensor that directly detects the rotation speed of the input shaft 11, an engine rotation speed sensor that detects the rotation speed of the crankshaft 2a, and a motor rotation speed sensor that detects the rotation speed of the motor drive shaft 3a.

The rotation speed of the output side member, either the second gear 13b2 or the second dog 14b, is obtained from the rotation speed of the output shaft 12 or a parameter corresponding thereto. A second rotation speed sensor mounted on the vehicle 1 detects the rotation speed of the output shaft 12 or a parameter corresponding thereto and sends it to the control device 40. Examples of the second rotation speed sensor include a rotation speed sensor that directly detects the rotation speed of the output shaft 12, and a wheel rotation speed sensor 8a (see Figure 1) that detects the rotation speed of the drive wheels 8.

During standby control, the rotation angle θ may be within the non-engagement angle range R0. During standby control, the rotation angle θ may be maintained at a predetermined angle within the non-engagement angle range R0, or may vary within the non-engagement angle range R0. In this embodiment, the control device 40 controls the shift actuator 32 during standby control to maintain the positioning roller 92 in contact with the apex 84a of the peak 84 between the first valley 83a and the second valley 83b (see FIG. 6). As a result, when the apex 84a of the peak 84 has a smoothly curved surface, as in this example, the force with which the positioning roller 92 presses against the apex 84a of the peak 84 is directed toward the axis X1 (see the arrow extending from the apex 84a in FIG. 6). Therefore, the torque that rotates the change cam 54 circumferentially due to the pressing force of the positioning roller 92 can be reduced to almost zero.

(Dog control)
When the control device 40 determines that the timing for engaging the dog clutch has arrived, it ends the standby control and executes the dog clutch engagement control (step S4). When the dog clutch engagement control is completed, the control device 40 ends the gear shift process. The dog clutch engagement control may also be referred to as engagement control.

Dog engagement control is a control performed on the shift actuator 32 to insert the second dog 14b into the accommodation space S of the second gear 13b2. Specifically, during dog engagement control, the control device 40 controls the shift actuator 32 so that the rotation angle θ detected by the gear position sensor 31 moves from the non-engagement angle range R0 to the second engagement angle range R2 (corresponding to the second engagement range). The second engagement angle range R2 is the range of rotation angle θ in which the second gear 13b2 and the second dog 14b engage.

From the state shown in FIG. 6, by further rotating the passive convex portion 82a around the axis X1 by the shift pawl 66, the second dog 14b enters the accommodation space S of the second gear 13b2. Furthermore, the biasing force of the positioning spring 93 (see FIG. 2) causes the positioning arm 91 to press the positioning roller 92 against the outer peripheral surface of the change cam 54, causing the positioning roller 92 to fit into the second valley portion 83b corresponding to the second gear, as shown in FIG. 8. As shown in FIG. 9, the second dog 14b abuts against the first surface 16a of the second gear 13b2, causing the second gear 13b2 to rotate together with the second dog 14b. In this way, the transmission gear pair 13 with which the second dog 14b is engaged transmits torque from the input shaft 11 to the output shaft 12.

With the configuration described above, the timing of engagement is determined based on the difference in rotation speed between the second dog 14b and the second gear 13b2, so the second dog 14b and the second gear 13b2 can be engaged in the next gear with a reduced difference in rotation speed, reducing gear shift shock.

In addition, in this embodiment, the control device 40 determines the timing for engaging the dog as the timing when the difference between the rotation speed of the second gear 13b2 and the rotation speed of the second dog 14b becomes equal to or less than a predetermined value, thereby reliably preventing the second dog 14b and the second gear 13b2 from engaging when there is a large difference between the rotation speed of the second gear 13b2 and the rotation speed of the second dog 14b.

<Other embodiments>
The present disclosure is not limited to the above-described embodiments, and the configurations thereof can be changed, added, or deleted.

For example, in the above embodiment, the gear transmission was a dog gear type in which the dog and the co-rotating gear were integrated, but the dog and the co-rotating gear may be separate. For example, the gear transmission may be a dog ring type in which a dog ring having a dog is provided so as to slide freely on the input shaft or the output shaft. Also, the dogs do not have to be arranged around both the input shaft 11 and the output shaft 12; the dogs for all gear stages may be arranged around only one of the input shaft 11 and the output shaft 12.

In addition, while the above embodiment describes a configuration in which the dog is moved by the shift actuator, the engagement portion moved by the shift actuator is not limited to this. For example, a dog may be fixed to the transmission gear, and a member having an engagement hole (or storage space) with which the dog engages may be moved by the shift actuator. In other words, the engagement portion that engages with the transmission gear pair to place the transmission gear pair in a power transmission state may be the dog, or an element with which the dog engages (for example, an engagement hole). Furthermore, there are no particular limitations on the shape of the engagement portion, i.e., the shape of the dog or the shape of the engagement hole with which the dog engages.

In the above embodiment, an electric motor was used as an example of the shift actuator, but the shift actuator is not limited to this and may be, for example, a hydraulically driven actuator. Furthermore, in the above embodiment, the shift actuator generates power to rotate the shift drum, thereby moving the dog serving as the engagement portion, but the gear transmission does not have to include a shift drum. For example, the engagement portion may be driven directly by the shift actuator without the intervention of the shift drum. Furthermore, the sensor that detects the position of the engagement portion does not have to be a gear position sensor. The sensor that detects the position of the engagement portion does not have to indirectly detect the position of the engagement portion, but may be a sensor that directly detects the position of the engagement portion in the direction of movement.

Furthermore, the number, shape, and arrangement of each component of the change mechanism 33 described in the above embodiment are merely examples. For example, the number of valleys in the change cam and the shape of the outer surface of the change cam are also merely examples. The distance between two adjacent valleys may be different from the distance between two other adjacent valleys.

In Figures 5, 7, and 9, the process of shifting from the first gear to the second gear is explained using one dog gear 15, but this is shown merely for ease of understanding. In other words, the control of the gear transmission is not limited to the control explained in Figures 5, 7, and 9. For example, the gear transmission does not have to have a dog gear that includes both a first dog and a second dog. The first dog and second dog may be provided on separate gears or on separate dog rings.

The shift command may be sent from another device instead of a shift switch. Alternatively, the control device may automatically generate the shift command and send it to a processing circuit that controls the shift actuator. For example, the control device may store a shift map that defines the relationship between vehicle speed, engine speed, throttle opening, and shift timing, and may automatically generate the shift command based on the shift map. Also, the shift command does not have to be a command to shift from one gear to another; for example, it may be a command to shift from neutral to a certain gear.

In addition, in the above embodiment, the control device 40 determines the timing at which the difference between the rotation speed of the second gear 13b2 and the rotation speed of the second dog 14b becomes equal to or less than a predetermined value as the dog engagement timing, but the method for determining the dog engagement timing is not limited to this.

For example, the control device may determine the standby time based on the difference between the rotation speed of the second gear and the rotation speed of the second dog, and the control device may determine the timing for engaging the dog as the time when the time during which the rotation angle detected by the gear position sensor is maintained within the disengagement angle range reaches the standby time. This makes it possible to reduce gear shift shock without measuring or calculating the difference in rotation speed between the second gear and the second dog.

In this case, the control device may determine the standby time using one or more of the reduction ratio of the first gear pair, the reduction ratio of the second gear pair, and the type of shift command, whether it is an upshift command or a downshift command, in addition to the difference between the rotation speed of the second gear and the rotation speed of the second dog. This makes it possible to determine an appropriate standby time that can reduce gear shift shock.

In addition, in the above embodiment, the control device 40 controlled the shift actuator 32 during standby control so as to maintain the positioning roller 92 in contact with the apex 84a of the peak 84 between the first valley 83a and the second valley 83b, but the method for controlling the rotation angle θ during standby control is not limited to this.

For example, the control device may control the shift actuator to apply a counterforce to the change cam that counters the torque generated in the change cam when the positioning roller is pressed against it. This reduces the rotational torque of the change cam caused by the pressing force of the positioning roller.

In this case, for example, as shown in FIG. 10, the control device may control the shift actuator 32 during standby control so that the positioning roller 92 remains in contact with the portion between the first valley 83a and the apex 84a of the peak 84. In other words, the control device 40 may control the shift actuator 32 so that a counter force f2 is applied to the change cam 54 that counters the torque f1 generated in the change cam 54 when the positioning roller 92 is pressed against it. This allows the shift gear to be engaged in a state where the difference in rotational speed between the shift gear and the engagement portion is reduced, thereby reducing shift shock.

Alternatively, the control device may control the shift actuator 32 so that the positioning roller 92 remains in contact with the portion between the second valley portion 83b and the apex 84a of the peak portion 84 during standby control.

In addition, in the above embodiment, an engine and an electric motor are exemplified as prime movers that transmit driving force to the input shaft, but the prime mover that transmits driving force to the input shaft is not limited to these. The prime mover may be, for example, an internal combustion engine, an external combustion engine, an electric motor, a fluid machine, or the like. The type of engine is also not particularly limited; for example, the engine may be a reciprocating engine or a rotary engine. For example, the engine may be a gasoline engine or a diesel engine. For example, the engine may be a two-stroke engine or a four-stroke engine. The first prime mover and the second prime mover may both be the same type of prime mover.

Furthermore, in a system equipped with a first prime mover and a second prime mover as in the above embodiment, the start timing of synchronous control may be the same or different for the first prime mover and the second prime mover. Furthermore, in the above embodiment, the vehicle 1 is a hybrid vehicle, but the vehicle does not have to be a hybrid vehicle. For example, the vehicle may be equipped with only one of an engine and an electric motor.

The vehicle is not limited to a motorcycle. For example, the vehicle may be, for example, a three-wheeled motor vehicle or a four-wheeled motor vehicle. In the above embodiment, a gear shift control device for a power system of a motorcycle was described, but the gear shift control device can also be applied to the power systems of other types of vehicles, such as three-wheeled motor vehicles and four-wheeled motor vehicles. The control device can also be applied to shift operations in systems other than vehicle power systems, such as machine tools.

Note that if the gear transmission is installed in a vehicle that is operated by the driver, the control device for the gear transmission may determine the engagement timing based on the difference between the rotation speed of the transmission gear and the rotation speed of the engagement portion, as well as the driving conditions or driving operation when the shift command is received. The control device for the gear transmission may determine the engagement timing based on the difference between the rotation speed of the transmission gear and the rotation speed of the engagement portion, as well as the driving conditions or driving operation when the shift command is received. For example, the control device for the gear transmission may determine the engagement timing using one or more of the reduction ratio of the transmission gear pair, the reduction ratio of the transmission gear pair, acceleration/deceleration, vehicle speed, engine rotation speed, and bank angle as the driving conditions. For example, the control device for the gear transmission may determine the engagement timing based on one or more of the accelerator operation, brake operation, and gear shift operation as the driving operation. Gear shift operations include upshift operations, downshift operations, and continuous gear shift operations.

Depending on the driving conditions or driving operation, there are cases where shift shock is relatively tolerable to the occupant, and there are also cases where it is desirable to reduce shift shock. The gear transmission control device determines the timing at which the difference between the rotation speed of the shift gear and the rotation speed of the engagement portion reaches a differential setting value as the engagement timing. In this case, the gear transmission control device may change the differential setting value depending on the driving conditions or driving operation when a shift command is received. For example, if the gear transmission control device determines that the driving conditions or driving operation when a shift command is received belongs to a first category corresponding to a situation in which the occupant can tolerate shift shock, it may increase the differential setting value from a predetermined reference value, thereby advancing the engagement timing. Furthermore, for example, if the gear transmission control device determines that the driving conditions or driving operation when a shift command is received belongs to a second category corresponding to a situation in which the occupant cannot tolerate shift shock, it may decrease the differential setting value from a predetermined reference value, thereby delaying the engagement timing.

For example, when acceleration is increasing, that is, when the driver is operating the accelerator, the occurrence of gear shift shock is expected by the occupant, and it is believed that the occupant can tolerate the shock. For this reason, when such an acceleration situation or accelerating driving operation occurs, the gear transmission control device may increase the differential setting value from the reference value, thereby advancing the engagement timing. For example, the gear transmission control device may increase the differential setting value as acceleration or accelerator opening increases, thereby advancing the engagement timing.

For example, when the vehicle speed is high, it is considered undesirable for the occupants to experience gear shift shock. For this reason, the control device for the gear transmission may reduce the set differential value from the reference value when the vehicle speed is higher than a predetermined speed, thereby delaying the engagement timing. For example, the control device for the gear transmission may reduce the set differential value the higher the vehicle speed, thereby delaying the engagement timing.

For example, when shifting between multiple (e.g., six) gears, shifting between low and medium gears (e.g., switching between 1st, 2nd, 3rd, and 4th gears) tends to result in greater shift shock than shifting between high gears (e.g., switching between 4th, 5th, and 6th gears), so it is desirable to reduce shift shock when shifting between low and medium gears. For this reason, the gear transmission control device may reduce the differential setting value used when shifting between low and medium gears compared to the differential setting value used when shifting between high gears. This may result in the engagement timing being slower when shifting between low and medium gears than when shifting between high gears. For example, the gear transmission control device may reduce the differential setting value as the gear is shifted to a lower gear, thereby slowing the engagement timing.

For example, when a vehicle is traveling on a highway, it is considered undesirable for the occupants to experience gear shift shock. For this reason, if the gear transmission control device determines that the road on which the vehicle is traveling is a predetermined road (such as a highway) on which it is desirable to reduce gear shift shock, it may reduce the set differential value from the reference value, thereby delaying the engagement timing. The road on which the vehicle is traveling may be determined using a position detector that detects the geographical position, such as a GPS (Global Positioning System) installed in the vehicle.

For example, when a vehicle is traveling on a gravel road, the vehicle vibrates up and down while traveling, and the shift shock is considered to be a relatively tolerable situation for the occupants. For this reason, if the gear transmission control device determines that the degree of vertical vibration of the vehicle has exceeded a threshold, it may increase the set differential value from a reference value, thereby accelerating the engagement timing. The degree of vertical vibration of the vehicle may be determined using an acceleration sensor mounted on the vehicle that detects vertical acceleration, or a stroke sensor in the suspension device.

If the vehicle is capable of turning by banking the body to one side in the vehicle width direction from an upright position, it is desirable to reduce the shock when the body is banked. For this reason, for example, the gear transmission control device may reduce the differential setting value from a reference value when the bank angle, which indicates the degree of inclination of the body, is greater than a predetermined angle, thereby delaying the engagement timing. For example, the gear transmission control device may reduce the differential setting value as the bank angle increases, thereby delaying the engagement timing.

The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, or any combination thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware or processor.

A gear transmission control device according to one aspect of the present disclosure includes an input shaft, an output shaft, multiple sets of shift gear pairs, each including a shift gear coaxial with the input shaft and a shift gear coaxial with the output shaft, a shift actuator that moves multiple engagement portions engageable with the multiple sets of shift gear pairs to place one of the multiple sets of shift gear pairs engaged with an engagement portion into a power transmission state, and a sensor that detects the position of the engagement portions. The control device includes a processing circuit that, upon receiving a shift command to shift a gear position, determines the engagement timing for initiating engagement between the shift gear and the engagement portions based on the difference between the rotational speed of the shift gear and the rotational speed of the engagement portions, and controls the shift actuator so that the position detected by the sensor is maintained within a disengagement range in which the multiple engagement portions do not engage with any of the multiple sets of shift gear pairs until the engagement timing is reached.

With the above configuration, the timing for starting engagement between the transmission gear and the engagement portion is determined based on the difference between the rotational speed of the transmission gear and the rotational speed of the engagement portion. This allows engagement to be achieved with a reduced difference in rotational speed between the transmission gear and the engagement portion, thereby reducing gear shift shock.

In addition, the processing circuit performs synchronization control on the prime mover that drives the input shaft, bringing the rotation speed of the engagement part and the rotation speed of the transmission gear that engages with it closer to each other, thereby reducing the difference in rotation speed between the transmission gear and the engagement part.

The multiple sets of shift gear pairs include a first shift gear pair including a first shift gear and a second shift gear pair including a second shift gear, and the multiple engagement portions include a first engagement portion engageable with the first shift gear and a second engagement portion engageable with the second shift gear, and the processing circuit, when receiving a shift command to shift from a first gear stage in which the first engagement portion engages with the first shift gear to a second gear stage in which the second engagement portion engages with the second shift gear, controls the shift actuator so that the position detected by the sensor moves from a first engagement range in which the first engagement portion engages with the first shift gear to the non-engagement range in which the first engagement portion does not engage with the first shift gear and the second engagement portion does not engage with the second shift gear, and determines the engagement timing for starting engagement between the second engagement portion and the second shift gear based on the difference between the rotational speed of the second engagement portion and the rotational speed of the second shift gear.

The gear transmission may include one or more shift forks that displace together with the multiple engagement portions, and a shift drum having a guide groove that guides the one or more shift forks, the shift actuator may generate power to rotate the shift drum, and the sensor may detect the rotation angle of the shift drum corresponding to the position of the engagement portions.

The processing circuit may determine the engagement timing to be the timing when the difference between the rotation speed of the transmission gear and the rotation speed of the engagement portion falls below a predetermined value. This reliably prevents the engagement portion and the transmission gear from engaging when there is a large difference in rotation speed between them.

The processing circuit may determine the standby time based on the difference between the rotational speed of the transmission gear and the rotational speed of the engagement portion, and may determine the timing at which the time during which the position detected by the sensor is maintained within the disengagement range reaches the standby time as the engagement timing. This makes it possible to reduce shift shock without measuring or calculating the difference in rotational speed between the transmission gear and the engagement portion.

The gear transmission is mounted on a vehicle that is driven by a driver, and the processing circuit may determine the engagement timing based on the difference between the rotation speed of the transmission gear and the rotation speed of the engagement portion, as well as the driving conditions or driving operation when the shift command is received. Depending on the driving conditions or driving operation, shift shock may be tolerated by the occupant, and the above configuration makes it possible to determine the engagement timing appropriate for the situation.

The processing circuit may determine the engagement timing using one or more of the reduction ratio of the transmission gear pair, the reduction ratio of the transmission gear pair, acceleration/deceleration, vehicle speed, engine speed, and bank angle as the driving conditions.

The processing circuit may determine the engagement timing using one or more of the following driving operations: accelerator operation, braking operation, and gear shift operation.

The gear transmission further includes a change cam that has an outer peripheral surface including a first valley corresponding to the first gear, a second valley corresponding to the second gear, and a peak between the first valley and the second valley, and rotates integrally with the shift drum; and a position lever having a positioning roller and a positioning spring that presses the positioning roller against the outer peripheral surface of the change cam. When the processing circuit receives a shift command to shift from the first gear to the second gear, it may control the shift actuator to maintain the positioning roller in contact with the peak of the peak on the outer peripheral surface until the engagement timing occurs. This reduces the rotational torque of the change cam due to the pressing force of the positioning roller.

The gear transmission further includes a change cam that has an outer peripheral surface including a first valley corresponding to the first gear, a second valley corresponding to the second gear, and a peak between the first and second valleys and rotates integrally with the shift drum; and a position lever having a positioning roller and a positioning spring that presses the positioning roller against the outer peripheral surface of the change cam. When the processing circuit receives a shift command to shift from the first gear to the second gear, it may control the shift actuator to apply a counterforce to the change cam that counters the torque generated in the change cam by the positioning roller being pressed against it until the engagement timing. This allows the change cam to be engaged with a reduced difference in rotational speed between the shift gear and the engagement portion, even in a gear transmission equipped with a mechanism that holds the change cam in a predetermined rotational position using a position lever, thereby reducing shift shock.

The processing circuit may control the shift actuator to maintain the positioning roller in contact with the portion of the outer peripheral surface between the first valley and the peak of the peak until the engagement timing is reached. With this configuration, the direction in which the change cam is rotated to shift from the first gear to the second gear can be made to coincide with the direction of the counterforce applied to the change cam. This makes it easier to control than maintaining the positioning roller in contact with the portion of the outer peripheral surface between the second valley and the peak of the peak.

A vehicle according to one aspect of the present disclosure is a vehicle that travels when operated by a driver, and includes a vehicle body equipped with a driving source, the gear transmission supported on the vehicle body, and the control device that controls the gear transmission.

A gear transmission control method according to one aspect of the present disclosure is a control method for a gear transmission for controlling the rotation angle of a shift drum that rotates to shift gears. When a shift command to shift from a first gear to a second gear is received, the method rotates the shift drum so that the rotation angle of the shift drum moves from a first engagement angle range, in which a first dog engages with a first gear corresponding to the first gear, to a non-engagement angle range, in which the first dog does not engage with the first gear and a second dog corresponding to the second gear does not engage with the second gear; the method determines a dog engagement timing for starting engagement of the second gear with the second dog based on the difference between the rotation speed of the second gear and the rotation speed of the second dog; and maintains the rotation angle of the shift drum within the non-engagement angle range until the dog engagement timing is reached.

The above method determines the timing for starting engagement between the transmission gear and the engagement portion based on the difference between the rotational speed of the transmission gear and the rotational speed of the engagement portion, allowing the transmission gear to be engaged in a state where the difference between the rotational speed of the transmission gear and the engagement portion is reduced, thereby reducing gear shift shock.

2: Engine 3: Drive motor 10: Gear transmission 11: Input shaft 12: Output shaft 13: Transmission gear 13b1: First transmission gear 13b2: Second transmission gear 14: Dog 14a: First dog 14b: Second dog 22: Shift fork 23: Shift drum 31: Gear position sensor 32: Shift actuator 33: Change mechanism 40: Control device 40a: Processor 54: Change cam 56: Position lever 66: Shift pawl 82: Passive convex portion 83a: First valley portion 83b: Second valley portion 84: Peak portion 84a: Peak 91: Positioning arm 92: Positioning roller 93: Positioning spring

Claims (12)

An input shaft;
An output shaft;
a plurality of sets of speed change gear pairs each including a speed change gear coaxially attached to the input shaft and a speed change gear coaxially attached to the output shaft;
a shift actuator that moves a plurality of engagement portions that can be engaged with the plurality of sets of transmission gear pairs, and places one of the plurality of sets of transmission gear pairs that is engaged with the engagement portion into a power transmission state;
A control device for a gear transmission comprising: a sensor that detects the position of the engagement portion,
the control device comprises a processing circuit;
The processing circuitry
When a shift command for shifting a gear position is acquired, determining a waiting time based on a difference between a rotation speed of the transmission gear and a rotation speed of the engagement portion;
determining the timing at which the time during which the position detected by the sensor is maintained within the non-engagement range reaches the standby time as the engagement timing at which the engagement between the transmission gear and the engagement portion starts, the non-engagement range being a range in which the plurality of engagement portions do not engage with any of the plurality of sets of transmission gears;
and controlling the shift actuator so that the position detected by the sensor is maintained within the disengagement range until the engagement timing is reached. An input shaft;
An output shaft;
a plurality of sets of speed change gear pairs each including a speed change gear coaxial with the input shaft and a speed change gear coaxial with the output shaft;
a shift actuator that moves a plurality of engagement portions that can be engaged with the plurality of sets of transmission gear pairs, and places one of the plurality of sets of transmission gear pairs that is engaged with the engagement portion into a power transmission state;
A control device for a gear transmission comprising: a sensor that detects the position of the engagement portion,
the control device comprises a processing circuit;
When the processing circuit receives a shift command for shifting a gear position,
controlling the shift actuator to disengage the engagement portion currently engaged with the transmission gear;
determining an engagement timing for starting engagement between the transmission gear and the engagement portion based on a difference between the rotation speed of the transmission gear and the rotation speed of the engagement portion, and a driving situation or driving operation of a vehicle equipped with the gear transmission when the shift command is acquired;
and controlling the shift actuator so that the position detected by the sensor is maintained within a non-engagement range in which the plurality of engagement portions do not engage with any of the plurality of sets of transmission gear pairs until the engagement timing is reached. the processing circuit determines, as the engagement timing, a timing at which a difference between the rotation speed of the transmission gear and the rotation speed of the engagement portion reaches a difference setting value;
3. The control device for a gear transmission according to claim 2, wherein the processing circuit changes the difference setting value depending on a driving situation or driving operation of a vehicle equipped with the gear transmission when a shift command for shifting a gear position is acquired. the plurality of sets of change gear pairs include a first change gear pair including a first change gear and a second change gear pair including a second change gear,
the plurality of engaging portions include a first engaging portion engageable with the first shift gear and a second engaging portion engageable with the second shift gear,
The processing circuitry
when a shift command is acquired to shift from a first gear stage in which the first engagement portion is engaged with the first shift gear to a second gear stage in which the second engagement portion is engaged with the second shift gear, the shift actuator is controlled so that the position detected by the sensor moves from a first engagement range in which the first engagement portion is engaged with the first shift gear to the non-engagement range in which the first engagement portion is not engaged with the first shift gear and the second engagement portion is not engaged with the second shift gear,
4. The control device for a gear transmission according to claim 1, wherein the engagement timing for starting engagement between the second engagement portion and the second shift gear is determined based on a difference between a rotation speed of the second engagement portion and a rotation speed of the second shift gear. The control device for a gear transmission according to claim 2, claim 3, or claim 4 that cites claim 2, wherein the processing circuit determines the engagement timing using one or more of the reduction ratio of the transmission gear pair, the reduction ratio of the transmission gear pair, acceleration/deceleration, vehicle speed, engine speed, and bank angle as the driving conditions. The gear transmission control device according to claim 2 , claim 3, or claim 4 that cites claim 2, wherein the processing circuit determines the engagement timing using one or more of an accelerator operation, a brake operation, and a gear shift operation as the driving operation . The gear transmission includes:
one or more shift forks that are displaced together with the plurality of engagement portions;
a shift drum having a guide groove that guides the one or more shift forks;
A change cam having an outer peripheral surface including a first valley portion corresponding to a first gear position, a second valley portion corresponding to a second gear position, and a peak portion between the first valley portion and the second valley portion, and rotating integrally with the shift drum;
a position lever having a positioning roller and a positioning spring that presses the positioning roller against the outer peripheral surface of the change cam,
The shift actuator generates power to rotate the shift drum,
The sensor detects a rotation angle of the shift drum corresponding to the position of the engagement portion,
7. The gear transmission control device according to claim 1, wherein, when the processing circuit receives a shift command to shift from the first gear to the second gear , the processing circuit controls the shift actuator so that the positioning roller remains in contact with the apex of the peak on the outer peripheral surface until the engagement timing is reached. The gear transmission includes:
one or more shift forks that are displaced together with the plurality of engagement portions;
a shift drum having a guide groove that guides the one or more shift forks;
A change cam having an outer peripheral surface including a first valley portion corresponding to a first gear position, a second valley portion corresponding to a second gear position, and a peak portion between the first valley portion and the second valley portion, and rotating integrally with the shift drum;
a position lever having a positioning roller and a positioning spring that presses the positioning roller against the outer peripheral surface of the change cam,
The shift actuator generates power to rotate the shift drum,
The sensor detects a rotation angle of the shift drum corresponding to the position of the engagement portion,
7. The gear transmission control device according to claim 1, wherein, when the processing circuit acquires a shift command to shift from the first gear to the second gear, the processing circuit controls the shift actuator so as to apply to the change cam a counter force that counters a torque generated in the change cam by pressing the positioning roller until the engagement timing is reached . 9. The control device for a gear transmission according to claim 8, wherein the processing circuit controls the shift actuator so that the positioning roller maintains contact with a portion of the outer peripheral surface between the first valley portion and the apex of the peak portion until the engagement timing is reached. A vehicle that runs by being operated by a driver,
a vehicle body equipped with a driving source;
the gear transmission supported on the vehicle body;
A vehicle comprising the control device according to any one of claims 1 to 9 , for controlling the gear transmission. A control method for a gear transmission for controlling a shift actuator that moves an engagement portion that can be engaged with a transmission gear in order to shift a gear position, comprising:
When a shift command for shifting a gear position is acquired, determining a waiting time based on a difference between a rotation speed of the transmission gear and a rotation speed of the engagement portion;
determining a timing at which the time during which the position of the engaging portion is maintained within the non-engagement range reaches the waiting time as an engagement timing at which the engagement between the transmission gear and the engaging portion starts, wherein the non-engagement range is a range in which the engaging portion does not engage with the transmission gear;
and maintaining a position of the engagement portion within the disengagement range until the engagement timing is reached. A control method for a gear transmission for controlling a shift actuator that moves an engagement portion that can be engaged with a transmission gear in order to shift a gear position, comprising:
When a shift command to shift gears is received,
disengaging the engagement portion that is currently engaged with the transmission gear;
determining an engagement timing for starting engagement between the transmission gear and the engagement portion based on a difference between a rotation speed of the transmission gear and a rotation speed of the engagement portion, and a driving situation or a driving operation when the shift command is acquired;
and maintaining a position of the engagement portion within a disengagement range in which the engagement portion does not engage with the transmission gear until the engagement timing is reached.