Mechanism of engagement

Abstract

To provide an engagement mechanism capable of eliminating the edge contact of dog teeth in shift operation which is performed at an arbitrary timing by an operator.SOLUTION: The engagement mechanism includes one-side rotary members 33, 35, 37 capable of shifting in the axial direction, other-side rotary members 9, 11, 17, 19, 23, 27 for attaining torque transmission between the one-side rotary members and themselves, dog teeth 33a, 33b, ...provided on the one-side and other-side rotary members, respectively, for engaging each other in the rotating direction to attain torque transmission, a shift mechanism 39 for shifting the one-side rotary bodies with shift operation to engage the dog teeth, a standby mechanism 41 provided on the shift mechanism for standing by the shift of the one-side rotary bodies with the shift operation, a pair of sensors for detecting the rotation positions of the dog teeth of the one-side and other-side rotary members, separately, and a control part 45 for calculating an engaging timing for engaging the dog teeth in no contact with each other from the rotation position detected by the pair of sensors, respectively, to cancel the standby of the standby mechanism.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an engagement mechanism for use in a saddle-riding type vehicle or the like.

Background Art

[0002] As a conventional engagement mechanism, there is one applied to a saddle-riding type vehicle described in Patent Document 1.

[0003] This engagement mechanism sets the start timing of processing based on the rotation angle of at least one of the input shaft and the output shaft detected by a rotation angle detector, and performs control divided into a case where dog contact occurs and a case where dog contact does not occur. Such control is such that at least the process of increasing or decreasing the output of the power source starts at different timings, based on the detection timing of the operation by the shift pedal operation detector, so that the timing of starting the increase or decrease of the output of the power source is different.

[0004] Thereby, for example, regardless of dog contact, processing can be started at a timing that cancels shock. As a result, it is said that even in a transmission in which the operation of switching the gear stage is performed by the operating force of the driver's foot, the inertia phase shock can be reduced.

[0005] However, such an engagement mechanism has a problem that it cannot prevent the contact of dog teeth against a shift pedal operation performed by an operator at an arbitrary timing. That is, when dog tooth contact occurs, the power reduction process is started at a timing later than when dog tooth contact does not occur. Therefore, although the influence of dog tooth contact can be suppressed, the problem of causing edge contact of dog teeth remains.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Disclosure of the Invention

[0007] The problem we are trying to solve is that while it is possible to suppress the effect of dog contact on shift operations performed at any time by the operator, it can still cause edge contact of the dog teeth. [Means for solving the problem]

[0008] The meshing mechanism of the present invention, in order to eliminate edge contact of the dog teeth during a shift operation performed at any timing by an operator, comprises: one rotating member that can be shifted in the axial direction; another rotating member for transmitting torque between itself and the first rotating member; dog teeth provided on each of the first and second rotating members for meshing in the rotational direction to transmit torque; a shift mechanism for shifting the first rotating member by a shift operation to mesh the dog teeth; a waiting mechanism provided on the shift mechanism for waiting for the shift operation to occur; a pair of sensors for separately detecting the rotational positions of the dog teeth of the first and second rotating members; and a control unit that calculates the meshing timing required for the dog teeth to mesh without colliding based on the rotational positions detected by the pair of sensors and releases the waiting mechanism from standby. The waiting mechanism comprises a transmission unit, a shift drive arm, and a release mechanism. The transmission unit transmits the operating force of the shift mechanism via an elastic body. The shift drive arm operates with the operating force transmitted via the transmission unit. The release mechanism stops the movement of the shift drive arm in a releaseable state, allowing the operating force to accumulate in the elastic body, and the release is performed by the control unit. It is characterized by the following: [Effects of the Invention]

[0009] Because the meshing mechanism of the present invention has the above configuration, the meshing timing for the dog teeth to mesh without colliding is calculated from the rotational position detected by each of the pair of sensors, and the standby mechanism is released, thereby eliminating edge contact of the dog teeth in response to shift operations performed at any timing by the operator. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view of the main part of a transmission having a meshing mechanism using dog teeth, relating to Example 1. [Figure 2]Figure 1 is a schematic diagram of the waiting mechanism used in the transmission. [Figure 3] Figure 1 relates to a quick shift sensor equipped with an elastic body, which is used in the waiting mechanism of the transmission. (A) is a cross-sectional view in the OFF state, (B) is during an upshift, and (C) is during a downshift. [Figure 4] Figure 1 shows a time chart for upshifts, including the transmission's waiting mechanism. [Figure 5] This is a schematic cross-sectional view relating to Example 2, showing another example of a transmission having a meshing mechanism using dog teeth. [Figure 6] Figure 5 is a cross-sectional view of the main part showing the shallow meshing of the dog teeth used in the transmission. [Figure 7] This is an exploded view of the main parts showing the relationship between the shift pin and the shift drum in a comparative example. [Figure 8] Figure 5 is a cross-sectional view of a key part showing an example of a failed engagement of the dog teeth used in the transmission. [Figure 9] Figure 5 is an exploded view of the shift drum, showing the position of the shift pin used in the transmission. [Figure 10] Figure 9 is an exploded view of the main components of the shift drum. [Figure 11] This is an explanatory diagram of the check mechanism of the shift drum. [Figure 12] This diagram shows a comparative example illustrating the relationship between the meshing state of the dog teeth and the position of the shift pin relative to the shift drum. [Figure 13] This diagram, relating to Example 2, shows the relationship between the meshing state of the dog teeth and the position of the shift pin relative to the shift drum. [Modes for carrying out the invention]

[0011] The objective of eliminating contact between the dog teeth edges during shift operations performed at any time by the operator was achieved as follows.

[0012] One rotating member that can be shifted axially, another rotating member for transmitting torque between the one rotating member, dog teeth provided on each of the one and the other rotating members and meshing in the rotational direction to transmit the torque, a shift mechanism for shifting the one rotating body by a shift operation to mesh the dog teeth, a waiting mechanism provided in the shift mechanism for waiting for the shift movement of the one rotating body by the shift operation, a pair of sensors for separately detecting the rotational positions of the dog teeth of the one and the other rotating members, and a control unit for calculating a meshing timing for the dog teeth to mesh without hitting based on the rotational positions respectively detected by the pair of sensors and releasing the waiting of the waiting mechanism.

[0013] The meshing mechanism is not limited in the object to be applied as long as the dog teeth can be meshed by an arbitrary shift operation of an operator. For example, it can be applied to four-wheel vehicles, two-wheel vehicles, buggies, snowmobiles, saddle-riding type vehicles, industrial machines, agricultural machines, ships, small airplanes, etc.

[0014] The one rotating member is realized by a clutch ring, but it may also be realized by a gear or the like that also serves as a clutch ring.

[0015] The dog teeth can be realized without particular limitation such as general dog teeth, dog teeth for seamless shift, etc.

[0016] The shift mechanism only needs to be able to shift the one rotating body by a shift operation to mesh the dog teeth, and can be realized without limitation by a shift operation by a shift pedal, a shift operation by a shift lever, etc.

[0017] The waiting mechanism only needs to be able to wait for the shift movement of the one rotating body by a shift operation, and can be realized including an elastic body, a solenoid, etc.

[0018] The standby mechanism comprises a transmission unit, a shift drive arm, and a release mechanism. The transmission unit transmits the operating force of the shift mechanism via an elastic body, the shift drive arm operates with the operating force transmitted through the transmission unit, and the release mechanism is implemented in a manner that allows the movement of the shift drive arm to be released, accumulating the operating force in the elastic body, and allowing the control unit to release it.

[0019] The movement of the shift drive arm is achieved by stopping it with a solenoid, but this can also be achieved by replacing the solenoid with an electric motor. Alternatively, the transmission section can be electrically configured to electrically detect the operation of the shift mechanism, and the shift drive arm can be operated by a solenoid or electric motor at a calculated meshing timing.

[0020] The control unit achieves the release of the standby mechanism by reducing the rotational difference or input torque between one and the other rotating member. This also includes achieving the release by reducing both the rotational difference and the input torque.

[0021] Reducing rotational difference or input torque is achieved by ignition cut in the case of an internal combustion engine, but it is sufficient if the rotational difference or input torque between one rotating member and the other can be reduced. Reducing rotational difference or input torque can also be achieved by changing the ignition timing, cutting fuel, applying an input shaft brake, or disengaging the starting clutch. In the case of an electric motor, it can also be achieved by reducing the current, applying an input shaft brake (regenerative braking), etc.

[0022] One rotating member is a clutch ring provided on the input or output shaft, and the other rotating member is one of the normally meshed variable speed gears provided on the input or output shaft. When the dog teeth of the clutch ring mesh with the dog teeth of the variable speed gear, torque is transmitted between the input and output shafts via the normally meshed variable speed gear.

[0023] The sensor was implemented by including an input axis sensor that detects rotational pulses on the input axis and an output axis sensor that detects rotational pulses on the output axis. [Examples]

[0024] [Transmission Overview] Figure 1 is a schematic cross-sectional view of the main part of a transmission having a meshing mechanism using dog teeth.

[0025] The transmission 1 shown in Figure 1 is used, for example, in a saddle-type vehicle. As shown in Figure 1, the transmission 1 includes an input shaft 3 and an output shaft 5. These input shaft 3 and output shaft 5 are rotatably supported in a transmission case (not shown) by bearings or the like.

[0026] The input shaft 3 and output shaft 5 are supported by a multi-speed transmission gear system consisting of 1st gears 7 and 9, 2nd gears 11 and 13, 3rd gears 15 and 17, 4th gears 19 and 21, 5th gears 23 and 25, and 6th gears 27 and 29, which are constantly meshed with each other.

[0027] The first gear 7 and third gear 15 of the input shaft 3 are supported on the input shaft 3 so as to be able to rotate together, and the second gear 13, fourth gear 21, fifth gear 25, and sixth gear 29 of the output shaft 5 are supported on the output shaft 3 so as to be able to rotate together.

[0028] The 2nd gear 11, 4th gear 19, 5th gear 23, and 6th gear 27 of the input shaft 3 are supported so as to be rotatable relative to the input shaft 3, and the 1st gear 9 and 3rd gear 17 of the output shaft 5 are supported so as to be rotatable relative to the output shaft 5.

[0029] The transmission 1 is equipped with a meshing mechanism 31 for shifting gears. The meshing mechanism 31 comprises one rotating member 33, 35, 37 and the other rotating member 9, 11, 17, 19, 23, 27, dog teeth 33a, 33b, 35a, 35b, 37a, 37b, 9a, 11a, 17a, 19a, 23a, 27a, a shift mechanism 39, a waiting mechanism 41, a pair of input shaft sensors 43a, 43b, and a control unit 45.

[0030] The rotating members 33, 35, and 37 are composed of first, second, and third clutch rings. The first, second, and third clutch rings 33, 35, and 37 are capable of shifting in the axial direction by spline fitting to the output shaft 5.

[0031] The other rotating members 9, 11, 17, 19, 23, and 27 are a first-speed gear 9 and a third-speed gear 17 on the output shaft 5 for transmitting torque with the first clutch ring 33, a second-speed gear 11 and a fifth-speed gear 23 on the input shaft 3 for transmitting torque with the second clutch ring 35, and a fourth-speed gear 19 and a sixth-speed gear 27 on the input shaft 3 for transmitting torque with the third clutch ring 37.

[0032] Dog teeth 33a and 33b are provided on the first clutch ring 33, and dog teeth 9a and 17a are provided separately on the first gear 9 and the third gear 17, respectively. The dog teeth 33a and 9a or the dog teeth 33b and 17a mesh in the rotational direction to transmit torque from the first gear 9 or the third gear 17 to the output shaft 5.

[0033] The dog teeth 35a and 35b are provided on the second clutch ring 35, and the dog teeth 11a and 23a are provided separately on the second gear 11 and the fifth gear 23, respectively. The dog teeth 35a and 11a or the dog teeth 35b and 23a mesh in the rotational direction to transmit torque from the input shaft 3 to the second gear 11 or the fifth gear 23.

[0034] The dog teeth 37a and 37b are provided on the third clutch ring 37, and the dog teeth 19a and 27a are provided separately on the 4th gear 19 and the 6th gear 27, respectively. The dog teeth 37a and 19a or the dog teeth 37b and 27a mesh in the rotational direction to transmit torque from the input shaft 3 to the 4th gear 19 or the 6th gear 27.

[0035] The shapes of the dog teeth 33a, 33b, 35a, 35b, 37a, 37b, 9a, 11a, 17a, 19a, 23a, and 27a are not particularly limited and can be various shapes such as normal dog teeth or seamless shift dog teeth. The embodiment will be described using a seamless shift.

[0036] The shift mechanism 39 shifts one of the first, second, or third clutch rings 33, 35, or 37 by a shift operation. The shift mechanism 39 includes a shift drum (not shown), a shift rod, a shift fork, etc., which are linked to the shift operation of the shift pedal described later. The rotation of the shift drum is transmitted via the shift cam and shift rod to the respective shift forks of the first, second, or third clutch rings 33, 35, or 37, and one of the first, second, or third clutch rings 33, 35, or 37 is shifted in response to the shift operation.

[0037] The first clutch ring 33 is shifted to engage the 1st gear dog clutch of dog teeth 33a and 9a or the 3rd gear dog clutch of dog teeth 33b and 17a. The second clutch ring 35 is shifted to engage the 2nd gear dog clutch of dog teeth 35a and 11a or the 5th gear dog clutch of dog teeth 35b and 23a. The third clutch ring 37 is shifted to engage the 4th gear dog clutch of dog teeth 37a and 19a or the 6th gear dog clutch of dog teeth 27a and 37b.

[0038] The waiting mechanism 41 is provided in the shift mechanism 39 and keeps the first clutch ring 33, the second clutch ring 35, or the third clutch ring 37 in standby mode for the shift movement caused by the shift operation.

[0039] The pair of sensors 43a and 43b are input and output shaft sensors that separately detect the rotational position of the dog teeth of one and the other rotating member. The input shaft sensor 43a is installed to detect the detection gear 47 of the input shaft 3, and the output shaft sensor 43b is installed to detect the detection gear 49 of the output shaft 5. The detection pulses from the input shaft sensor 43a and the output shaft sensor 43b are input to the control unit 45.

[0040] The input shaft sensor 43a detects the rotational position of the input shaft 3. Based on this detection, the rotational positions of the dog teeth 35a, 35b, 37a, 37b of the second clutch ring 35 and the third clutch ring 37, and the dog teeth 9a, 17a of the first and third gears 9, 17 are detected.

[0041] The output shaft sensor 43b detects the rotational position of the output shaft 5. Based on this detection, the rotational positions of the dog teeth 33a and 33b of the first clutch ring 33, and the dog teeth 11a, 19a, 23a, and 27a of the 2nd, 4th, 5th, and 6th gears 11, 19, 23, and 27 are detected.

[0042] The control unit 45 calculates the meshing timing so that the dog teeth 33a, 9a, 35a, 11a, 33b, 17a, 37a, 19a, 35ba, 23a, 37b, and 27a of each gear step do not collide during gear changes, and controls the waiting mechanism 41 to release its standby state.

[0043] The control unit 45 is configured with an MPU, ROM, RAM, etc. The control unit 45 calculates the meshing timing for the meshing from the input pulse signal, the relative rotational positions of the input and output shafts 3 and 5 when the dog teeth 35a, 11a, 33b, 17a, 37a, 19a, 35ba, 23a, 37b, 27a of each gear shift mesh, information on which gear's dog teeth 33a, 9a... are meshing, and a count of the rotational positions of the dog teeth 33a, 9a... of each gear shift.

[0044] (Shift mechanism and standby mechanism) Figure 2 is a diagram showing the shift pedal and other components of the shift mechanism 39.

[0045] The shift pedal 51 in Figure 2 is of a type that is operated by the driver's foot in a saddle-type vehicle, and is rotatably supported on the vehicle body side by a pivot shaft 53. The shift pedal 51 includes an operating part 55 for foot operation and a rod connecting part 56.

[0046] One end of the interlocking rod 58 is rotatably connected to the rod connection section 56 as a transmission section, and a contact plate 57 is fixed to the other end of the interlocking rod 58. The interlocking rod 58 has an extendable structure and is equipped with an elastic body 59, and is equipped with a shift sensor (not shown). The detection signal from the shift sensor is input to the control unit 45. In Figure 2, the elastic body 59 is shown, but as described later, it is arranged inside the case as a quick shift sensor. The elastic body 59 of the standby mechanism 41 is shared with the elastic body of the quick shift sensor. The operation of the standby mechanism 41 and the quick shift sensor will be described later along with the operation of the shift pedal 51.

[0047] An arm connecting portion 60 is fixed to the contact plate 57 together with the interlocking rod 58 so as to sandwich the contact plate 57. The arm connecting portion 60 is coupled to one end of the shift drive arm 61 so as to be rotatable relative to it. The other end of the shift drive arm 61 has an axis 61a that is coaxially coupled to a shift shaft (not shown) which is not shown. When the shift drum (not shown in this embodiment) rotates via a shift ratchet (not shown) due to the rotation of the shift shaft, one of the first, second, or third clutch rings 33, 35, or 37 is shifted as described above.

[0048] A stopper 63 is positioned on the contact plate 57, aligned with the arm connecting portion 60. The stopper 63 is rotatably supported on the vehicle body side. The release rod 65a of the release mechanism 65 is rotatably connected to the connecting projection 63a around the rotation axis of the stopper 63. The rotation of the stopper 63 is determined by the release mechanism 65, and the roller portion 63b at the tip contacts the contact plate 57. The release mechanism 65 is composed of a solenoid or the like. The release mechanism 65 is connected to the control unit 45 and is electrically controlled.

[0049] The standby mechanism 41 consists of a release mechanism 65, a stopper 63, a contact plate 57, and a shared elastic body 59, and the operating force of the shift pedal 51 is temporarily stored in the elastic body 59. The release mechanism 65 is operated by the control unit 45, and the standby mechanism 41 is released.

[0050] Figure 3(A) is a cross-sectional view of the quick shift sensor when it is OFF. Figure 3(B) is a cross-sectional view of the quick shift sensor when it is shifting up. Figure 3(C) is a cross-sectional view of the quick shift sensor when it is shifting down.

[0051] As shown in Figure 3, the interlocking rod 58 is divided into a first rod 58a on the pedal side and a second rod 58b on the contact plate side. The quick shift sensor 67, which includes an elastic body 59, is interposed between the first and second rods 58a and 58b. A case 67a is fixed to the first rod 58a, and a pair of flanges 67b and 67c, which are located inside the case 67a, are provided on the second rod 58b. Movable contact plates 67d and 67e are positioned between the flanges 67b and 67c, and the elastic body 59 is interposed between the contact plates 67d and 67e. A switch 67f is attached to one of the contact plates 67d, and the contacts of the switch 67f face the other contact plate 67e. The contact plates 67d and 67e are electrically connected to the control unit 45, and the detection signal from the switch 67f is input to the control unit 45.

[0052] (Shift up operation) In Figure 2, when the operating part 53 of the shift pedal 51 is operated with the foot to shift up in the upward direction (arrow direction), the rod connecting part 56 presses the interlocking rod 58 against the contact plate 57 in the axial direction.

[0053] When the interlocking rod 58 is pressed, the case 67a of the first rod 58a presses against one of the contact plates 67d, as shown in Figure 3. This pressing causes the contact plate 67d to move relative to the second rod 58b from the state shown in Figure 3(A) to Figure 3(B), compressing the elastic body 59 and accumulating operating force. The switch 67f then contacts the other contact plate 67e. This contact turns the switch 67f ON, detecting the shift operation and inputting the detection signal to the control unit 45.

[0054] If the meshing timing calculated by the control unit 45 is not correct, the standby mechanism 41 will not be released in the state shown in Figure 2. If it is correct, the release mechanism 65 of the standby mechanism 41 will be operated under the control of the control unit 45. This operation pulls the connecting projection 63a of the stopper 63, causing the stopper 63 to rotate and the roller portion 63b to instantly detach from the contact plate 57. This detachment releases the positioning of the contact plate 57, releasing the elastic body 59 and extending the interlocking rod 58, causing the contact plate 57 to move instantaneously.

[0055] This movement pushes one end of the shift drive arm 61 through the arm connecting portion 60, causing the shift drive arm 61 to rotate around the shaft 61a. The rotation of the shaft 61a causes the shift drum to rotate via the shift shaft and shift ratchet. This rotation causes one of the first, second, or third clutch rings 33, 35, or 37 to shift in response to the upshift operation, allowing the dog teeth 33a, 9a (1st gear), 35a, 11a (2nd gear), 33b, 17a (3rd gear), 37a, 19a (4th gear), 35ba, 23a (5th gear), and 37b, 27a (6th gear) of each gear from 1st to 6th gear to engage at the appropriate timing during upshifts.

[0056] (Downshift operation) When the operating part 53 of the shift pedal 51 is pressed down by foot operation (in the opposite direction of the arrow), the rod connecting part 56 moves in a direction that pulls the interlocking rod 58 axially relative to the contact plate 57.

[0057] When the interlocking rod 58 is pulled, the case 67a is pulled away from the other contact plate 67e by the first rod 58a, as shown in Figure 3. This pulling motion causes the other contact plate 67e to move away from the flange 67c, as shown in Figure 3(C), and the elastic body 59 is compressed, causing the other contact plate 67e to contact the switch 67f. This contact turns on the switch 67f, detecting the shift operation, and the detection signal is input to the control unit 45.

[0058] During a downshift operation, the waiting mechanism 41 does not operate, and the control unit 45 stores the gear position based on the signal from switch 67f, and can engage the dog teeth 33a, 9a (1st gear), 35a, 11a (2nd gear), 33b, 17a (3rd gear), 37a, 19a (4th gear), and 35ba, 23a (5th gear) for each gear position from 1st to 5th.

[0059] (Timing of bite) The meshing timing is detected by detecting the phase of the input and output shafts using pulse sensors. The input shaft 3 is mechanically connected to the input-side dog teeth of each gear stage by gear meshing or by a clutch ring. For example, in 1st and 3rd gear, the dog teeth 9a and 17a are connected to the input shaft 3 by the meshing of the 1st gear 7 and 9, and the meshing of the 3rd gear 15 and 17. In 2nd and 5th gear, the dog teeth 35a and 35b are connected to the input shaft 3 by a second clutch ring 35. In 4th and 6th gear, the dog teeth 37a and 37b are connected to the input shaft 3 by a third clutch ring 37.

[0060] Similarly, the output shaft 5 is mechanically connected to the output-side dog teeth of each gear stage by gear meshing or by a clutch ring. For example, in 1st and 3rd gear, the dog teeth 33a and 33b are connected to the output shaft 5 by the first clutch ring 33. In 2nd and 5th gear, the dog teeth 11a and 23a are connected to the output shaft 5 by the meshing of the 2nd gear 11 and 13, and the 5th gear 23 and 25. In 4th and 6th gear, the dog teeth 17a and 27a are connected to the output shaft 5 by the meshing of the 4th gear 19 and 21, and the 6th gear 27 and 29.

[0061] Therefore, by counting the detection pulses of the input shaft 3 and the output shaft 5, the rotation angles of the dog teeth 33a, 9a (1st gear), 35a, 11a (2nd gear), ... for each gear stage can be calculated.

[0062] When the dog teeth 33a, 9a (1st gear), 35a, 11a (2nd gear), etc. of the dog clutch of any gear are engaged, the gears and dog teeth of the other gears rotate regularly at a constant ratio. As a result, the engagement timing for the dog teeth of each gear to engage without colliding appears regularly.

[0063] When the gear is shifted to any gear and drive torque is applied, there is no play in the transmission of driving force between the input and output shafts 3 and 5. At this time, the control unit 45 remembers that the relative angle between the input and output dog teeth of the dog clutch of the current gear is 0°. This operation is called calibration. Calibration is performed each time the dog clutch of each gear engages while drive torque is applied.

[0064] Let's assume the gear that was calibrated is, for example, 3rd gear.

[0065] When upshifting to 4th gear from a calibrated state, a relative angle is created between the input dog teeth 17a and output dog teeth 33b of the 3rd gear from the moment the 4th gear dog clutch engages. This change in angle is detected to determine whether the 3rd gear has engaged or disengaged. From the moment of disengagement, the rotation angle count of the 3rd gear dog teeth 17a and 33b is started by the detection pulse.

[0066] Pulse counting is performed independently for the input and output dog teeth of each gear. For example, in a 6-speed transmission, 12 pulse counters are set in the control software of the control unit 45.

[0067] When shifting up from 3rd to 4th gear, the relative angle is calculated from the pulse count of the pulse counter to determine the meshing timing of the dog teeth 19a and 37a.

[0068] (Determining the rotation angle of the dog teeth) The initial calibration involves engaging all stages one by one. The control unit 45 stores the relationship between the detection pulses of input axis sensors 43a and 43b on input / output axes 3 and 5 as the engaged position. The control unit stores the phase at which the dog teeth engaged and also stores the number of rotations after the dog teeth disengage to calculate the timing for the dog teeth to align again during subsequent engagement.

[0069] (Dog phase of input / output axis) The angle at which the dog teeth align again is calculated from the point when the bite is disengaged.

[0070] Gear ratio × (360 / number of pawls) = rotation angle at which the next dog teeth are at the same angle Example 1: In the case of 1st gear with a gear ratio of 15 / 36 and 5 teeth on the dog gear, the rotation angle of the 1st gear 9 on the output shaft 5 is calculated from the detection pulse on the input shaft 3. (36 / 15) × (360 / 5) = 172.8°

[0071] The rotation of input shaft 3 is 172.8°, and the dog teeth 9a have the same rotation angle.

[0072] Example 2: In the case of a 2nd gear with a gear ratio of 19 / 39 and 5 teeth on the dog gear, the rotation angle of the 2nd gear 11 on the input shaft 3 is calculated from the detection pulse of the output shaft 5. (19 / 39) × (360 / 5) = 35.07692°

[0073] The rotation of input shaft 3 is 147.7895°, and the dog teeth 11a have the same rotation angle.

[0074] The counter memory of the control unit 45 is reset to 0° at every rotation angle that is divisible by the unit to prevent overflow.

[0075] The rotation angle that divides evenly in Example 1 is the least common multiple of (36, 15) → 180 rotations. The rotation angle that divides evenly in Example 2 is the least common multiple of (39, 19) → 741 rotations. The reset occurs at this angle.

[0076] (N→1st gear) shift (1) Detection of the rotation angle of the 1st gear 9 The first gear 9 rotates in mesh with the first gear 7 on the input shaft 3, resulting in a rotation angle equal to the first gear reduction ratio, and counts the detection pulses of the input shaft sensor 43a on the input shaft 3 side. (Number of pulses on the input shaft × Angle of pulse interval × 1st gear reduction ratio) = Rotation angle of 1st gear 9

[0077] (2) Detection of the rotation angle of the first clutch ring The first clutch ring 33 rotates integrally with the output shaft 5 and counts the detection pulses of the output shaft sensor 43b on the output shaft 5 side. (Number of pulses on the output shaft side × Angle of pulse interval) = Rotation angle of the first clutch ring 33

[0078] (3) Calculation of meshing timing The control unit 45 stores the time it takes to reach the axial distance at which engagement becomes possible from the start of the shift. The relative angle between the first gear 9 and the first clutch ring 33 is calculated, and the shift start timing is calculated by working backward from the time it takes for the dog teeth 33a of the first clutch ring 33 to reach the axial distance at which engagement with the dog teeth 9a of the first gear 9 can occur.

[0079] (1st gear → 2nd gear) shift The first gear 9 and the first clutch ring 33's first gear dog clutch (dog teeth 9a, 33a) are engaged and driving, and then the second clutch ring 35 and the second gear 11's second gear dog clutch (dog teeth 35a, 11a) are engaged. The first gear 9 and the first clutch ring 33's first gear dog clutch disengage.

[0080] (4) Detection of the rotation angle of the 2nd gear 11 The second gear 11 rotates in mesh with the second gear 13 on the output shaft 5, resulting in a rotation angle equal to the second gear reduction ratio, and counts the detection pulses of the output shaft sensor 43b on the output shaft 5 side. (Number of pulses on the output shaft × Angle of pulse interval × 2nd gear reduction ratio) = Rotation angle of 2nd gear 11

[0081] (5) Detection of the rotation angle of the second clutch ring The second clutch ring 35 rotates integrally with the input shaft 3 and counts the detection pulses of the input shaft sensor 43a on the input shaft 3 side. (Number of pulses on the input shaft side × Angle of pulse interval) = Rotation angle of the second clutch ring 35

[0082] (6) Calculation of meshing timing The control unit 45 stores the time it takes to reach the axial distance at which engagement becomes possible from the start of the shift. The relative angle between the second gear 11 and the second clutch ring 35 is calculated, and the shift start timing is calculated by working backward from the time it takes for the dog teeth 35a of the second clutch ring 35 to reach the axial distance at which engagement with the dog teeth 11a of the second gear 11 can occur.

[0083] Rotational phase control is performed by ignition cut at the engagement timing in every gear. However, ignition cut can be omitted.

[0084] (Angular velocity detection) In the above explanation, the angular change can be estimated by calculating the angular velocity from the time between the previous detection pulses, and then estimating how many milliseconds later the angle will reach based on this angular velocity information.

[0085] (Time Chart) Figure 4 is a time chart showing the relationship between the waiting mechanism, shift drum, and dog gear meshing timing during upshifts. The left side of Figure 4 shows an example of an upshift, specifically a shift from 3rd to 4th gear. The right side of Figure 4 shows another example of an upshift, specifically a shift from 2nd to 3rd gear.

[0086] The left side of Figure 4 (3-4UP) shows a time chart related to shifting up from 3rd to 4th gear. From top to bottom, it shows the square wave of the gear shift command, the square wave of the standby mechanism release signal, the shift drum displacement line, the 3rd relative angle (the relative angle of dog tooth 33b of the 3rd gear dog clutch to dog tooth 17a), the 4th dog matching period (the matching period of dog tooth 19a of the 4th gear dog clutch to dog tooth 37a), the 3rd dog matching period (the matching period of dog tooth 33b of the 3rd gear dog clutch to dog tooth 17a), and the ignition cut signal.

[0087] In the rectangular wave of the gear shift command, time A is the engagement point of the dog tooth 19a of the 4th gear dog clutch with the dog tooth 37a.

[0088] As described above, the shift operation using the shift pedal 51 is performed by the rider with their foot at any time they choose. This timing may or may not match the meshing timing calculated by the control unit 45.

[0089] When a gear shift command is received from the shift pedal 51 but the engagement timing is not matched, the standby mechanism release signal is not issued, and the state shown in Figure 2 is maintained.

[0090] When a gear shift command is received from the shift pedal 51 and the engagement timing is correct, a standby mechanism release signal is issued. Considering the operating time of the standby mechanism 41 and the shift drum, for example about 50 m / s, the standby mechanism 41 is released, and at point A, the third clutch ring 37 is operated to engage the dog teeth 37a of the 4th gear dog clutch with the dog teeth 19a.

[0091] At this time, the shift drum, which is held in the 3rd position by the waiting mechanism 41, moves out of position as the waiting mechanism 41 releases it, and moves to the 4th position.

[0092] The relative angle of the 3rd gear before and after shifting, which is the relative angle of the dog tooth 33b of the 3rd gear dog clutch with respect to the dog tooth 17a, is 0° when the 3rd gear dog teeth are engaged. When the 3rd gear dog teeth disengage and the 4th gear dog teeth engage, the relative angles of the 3rd gear dog teeth 17a and 33b coincide every 120°, assuming there are 3 dog teeth per rotation.

[0093] The matching period of the 4th dog clutch, which is the matching period of the dog tooth 19a of the 4th gear dog clutch with respect to the dog tooth 37a, appears at a constant period as described above, and the waiting mechanism 41 is released so that it engages at that timing. After the 4th gear engages, the relative angle of the 3rd gear dog teeth shifts as described above, and the relative angle of the 4th gear dog teeth becomes 0°.

[0094] (Ignition cut timing) To reduce the shock torque caused by inertial mass during upshifts, ignition cut is performed at the appropriate timing.

[0095] The engagement timing is determined by the relative angle calculated from the number of detected pulses, as described above. However, there is a time delay between the start of the gear shift operation and the actual engagement of the dog clutch teeth. Therefore, the actual shift timing is estimated by taking this time delay into account in addition to the sensor signal.

[0096] Ignition cut-off begins a predetermined time before the appropriate timing and continues for a predetermined period. The appropriate timing and duration are determined by the torque, inertial mass, and rotational speed applied at the time of gear change.

[0097] Figure 4 shows two examples, C and D.

[0098] The ignition cut-off in (C) is performed for a set time, a predetermined time before the meshing point A.

[0099] The ignition cut-off in (D) continues from a predetermined time before to a predetermined time after the meshing point A.

[0100] This allows the gear shift to be performed while reducing the rotational difference between the clutch ring and the dog teeth between the gears, which are rotating relative to each other before engagement, thereby suppressing shift shock.

[0101] The right side of Figure 4 (2-3UP) shows a portion of the time chart for shifting up from 2nd to 3rd gear.

[0102] For example, when shifting up to third gear, the calculated relative angle of the dog tooth 33b of the third-gear dog clutch with respect to the dog tooth 17a results in a discrepancy t between this angle and the actual meshing timing. Therefore, this discrepancy t is reset by calibration as described above, and the discrepancy does not accumulate.

[0103] [Effects and Effects] In this embodiment of the present invention, the pair of input shaft sensors 43a and 43b each detect rotational positions, and the meshing timing required for the dog teeth to mesh without colliding is calculated from these positions, and the standby mechanism 41 is released. This eliminates edge contact of the dog teeth 33a, 9a (1st gear), 35a, 11a (2nd gear), 33b, 17a (3rd gear), 37a, 19a (4th gear), 35ba, 23a (5th gear), and 37b, 27a (6th gear) for shift operations performed at any timing by the operator.

[0104] The waiting mechanism 41 can share the elastic body 59 of the quick shift sensor, which simplifies the structure. [Examples]

[0105] Figure 5 is a schematic cross-sectional view relating to Embodiment 2, showing another example of a transmission having a meshing mechanism using dog teeth. In this Embodiment 2, the basic configuration is the same as in Embodiment 1, and the same or corresponding components are denoted by the same reference numerals, and redundant explanations are omitted.

[0106] [Transmission Overview] Transmission 1 in Figure 5 has a structure that allows for seamless shifting during upshifts, similar to Example 1. In Transmission 1 of Example 1, the dog teeth are engaged by aligning the meshing timing during downshifts. Therefore, as long as the function for aligning the meshing timing is working, failure of the dog teeth to mesh will not basically occur.

[0107] However, if the function for adjusting the meshing timing fails, or if the transmission is designed for seamless shifting without a function for adjusting the meshing timing, it may lead to malfunctions as described below.

[0108] The transmission 1 in this embodiment 2 is a 4-speed transmission, and both the first and second clutch rings 33 and 35 are located on the output shaft 5. The second clutch ring 35 is located between the second gear 13 and the fourth gear 21.

[0109] An input gear 71 is supported on the input shaft 3 via a clutch 69. The input gear 71 meshes with a drive gear 73, which is coupled to the crankshaft 77 of the engine 75.

[0110] Therefore, the output of the engine 75 can be transmitted to the input shaft 3 via the drive gear 73 and input gear 71 by engaging the clutch 69.

[0111] The first and second clutch rings 33 and 35 are configured to engage with the shift forks 79 and 81. The shift pins 83 and 85 of the shift forks 79 and 81 are positioned to engage with the shift cams 89 and 91 of the shift drum 87.

[0112] When the shift drum 87 rotates due to a shift operation, the shift cams 89 and 91 guide the shift pins 83 and 85. This guidance allows the first and second clutch rings 33 and 35 to move selectively via the shift forks 79 and 81, depending on the shape of the shift cams 89 and 91. This movement allows for selective engagement of the dog teeth in response to the shift operation.

[0113] The shift drum 87 is equipped with a check mechanism 93. The check mechanism 93 has a check cam 95 attached to the end of the shift drum 87. A check ball 99, biased by a check spring 97 supported on the transmission case side, elastically contacts the circumferential surface of the check cam 95.

[0114] [Dog Clutch] Figure 6 is a cross-sectional view of the main part showing the shallow meshing of the dog teeth used in the transmission shown in Figure 5.

[0115] The shape of the dog teeth in Figure 6 is the same structure from the 1st gear dog clutch to the 4th gear dog clutch. The dog clutch is formed for so-called seamless shifting and has a tooth tip slope for disengagement, which causes the load described later.

[0116] This explanation will focus on the 3-speed dog clutch as an example for seamless shifting. The 1st, 2nd, and 4th gear dog clutches are basically the same.

[0117] As shown in Figure 6, the 3rd gear dog clutch has multiple dog teeth 33b on the first clutch ring 33 and multiple dog teeth 17a on the 3rd gear 17.

[0118] The dog teeth 33b and 17a are set to a uniform height in the circumferential direction. The dog teeth 33b and 17a are formed in a helical shape with respect to the axis of the output shaft 5. Therefore, when the dog teeth 33b and 17a engage or disengage, they are relatively helically guided with a screw-like action.

[0119] The tip of the dog teeth 17a of the 3rd gear 17 is provided with a tip bevel 101 for release guidance. The dog teeth 17a are provided with a drive meshing surface 103 on the rear tip side in the drive torque transmission direction and a movement guide surface 105 on the root side. The front part of the dog teeth 17a is provided with a coast meshing surface 107.

[0120] The tooth tip bevel 101 is formed to be gradually inclined in the rotational direction with respect to the rotation axis of the output shaft 5. This inclination allows the tooth tip bevel 101 to guide the tooth tip of the other dog tooth 33b by coasting torque, thereby generating an axial force in the disengagement direction relative to the first clutch ring 33.

[0121] The coast meshing surface 107 of the dog teeth 17a engages with the dog teeth 33b during gear changes and engine braking. The coast meshing surface 107 rises in the axial direction of the output shaft 5 at the lower end of the inclination of the tooth tip bevel 101. The coast meshing surface 107 is set to be inclined rearward from the tooth root toward the tooth tip bevel 101 with respect to the direction of transmission of coasting torque with respect to the rotation axis of the output shaft 5. This inclination setting of the coast meshing surface 107 has the effect of pulling the dog teeth 33b in the meshing direction when the dog teeth 33b engage due to coasting torque.

[0122] The tip surface 108 of the dog teeth 33b is formed as a flat surface or a rounded surface (curved surface). The dog teeth 33b has a drive meshing surface 109 and a coast meshing surface 111. The drive meshing surface 109 and the coast meshing surface 111 are set to be inclined in accordance with the drive meshing surface 103 and coast meshing surface 107 of the dog teeth 17a.

[0123] The first meshing position where the coast meshing surfaces 107 and 111 engage is the position where the first clutch ring 33 and the third gear 17 engage due to their relative rotation during coasting torque. The second meshing position is the shallow meshing position shown in Figure 6, where the tip of the dog tooth 33b faces the tip bevel 101 in the direction of rotation.

[0124] In other words, when shifting up from 3rd gear to 4th gear via simultaneous engagement, the moving guide surface 105 moves the first clutch ring 33 so that the dog teeth 33b of 3rd gear move from the first engagement position to the second engagement position.

[0125] When shifting up from 3rd gear to 4th gear, the first and second clutch rings 33 and 35 engage simultaneously in response to the rotation of the shift drum 87 caused by the shift-up operation of the shift pedal 51. This simultaneous engagement results in a state where the 3rd gear 17 is coupled to the output shaft 5 by the engagement of the first clutch ring 33, and the 4th gear 21 is coupled to the output shaft 5 by the engagement of the second clutch ring 35.

[0126] When the engagement of the 3rd gear dog clutch is changed from the 3rd gear dog clutch to the 4th gear dog clutch after this simultaneous engagement, the 3rd gear dog teeth 17a and 33b receive relative torque, causing the tips of the dog teeth 33b to come into contact with the tip bevel surface 101 of the dog teeth 17a, and moving the first clutch ring 33 away from the 3rd gear 17.

[0127] In this case, the relative rotation is caused by the simultaneous engagement of the first and second clutch rings 33 and 35, resulting in a coasting torque generated in the lower gear and a drive torque generated in the upper gear.

[0128] When shifting down from 4th gear to 3rd gear, the second clutch ring 35 disengages in response to the rotation of the shift drum 87 caused by the downshift operation of the shift pedal 51, and the dog teeth 33b of the first clutch ring 33 receive a moving force so that they are in the first engagement position with the dog teeth 17a of the 3rd gear 17.

[0129] (Relative position of the shift cam and shift drum during downshifting) Figure 7 is an exploded view of the main parts showing the relationship between the shift pin and the drum groove in a comparative example. Figure 8 is a cross-sectional view of the main parts showing an example of a failed engagement of the dog teeth used in the transmission of Figure 5. Figure 9 is an exploded view of the shift drum showing the position of the shift pin used in the transmission of Figure 5. Figure 10 is an exploded view of the main parts of the shift drum of Figure 9. Figure 11 is an explanatory diagram of the check mechanism of the shift drum.

[0130] Let's continue with the example of shifting down from 4th to 3rd gear. As shown in Figure 7, in the conventional comparative example, the shift pin 83 that is to be shifted is moved to the cam lobe apex 115 during downshifting. In other words, the rotation of the shift drum 87 moves the shift pin 83 to the cam lobe apex 115, thereby providing a moving force to the first clutch ring 33.

[0131] At this time, there is no problem if the dog teeth 33b and 17a properly mesh with the first meshing position, but sometimes the meshing fails and the situation shown in Figure 8 occurs.

[0132] If torque T continues to be transmitted in the state shown in Figure 8, the tooth tip of the dog tooth 33b increases the contact force with the tooth tip bevel 101 of the dog tooth 17a. Due to this contact force, the dog tooth 33b receives a guiding force on the tooth tip bevel 101, resulting in the generation of an excessive axial force P.

[0133] This axial force P presses the shift pin 83 against the cam lobe apex 115 as shown in Figure 7, which can cause malfunctions in the shift mechanism.

[0134] In contrast, in Example 2, as shown in Figures 9 and 10, the shift pin 83 is moved to a position shifted forward from the cam lobe apex 115, thereby applying a moving force to the first clutch ring 33.

[0135] Therefore, when an axial force P is generated, the thrust of the shift pin 83 presses against the cam lobe of the shift drum 87, causing the shift drum 87 to rotate and releasing the thrust of the shift pin 83.

[0136] As shown in Figures 5 and 11, the rotation of the shift drum 87 activates the check mechanism 93 attached to the shift drum 87. This action causes the check cam 95 to rotate together with the shift drum 87. This rotation causes the cam lobe of the check cam 95 to compress the check spring 97 via the check ball 99. The compressed check spring 97 stores elastic energy for its return.

[0137] Therefore, when the meshing timing of the dog teeth 17a and 33b next aligns, the elastic energy of the check spring 97 is released, and the check cam 95 is rotationally biased so that the check ball 99 falls into the gap between the cam lobes of the check cam 95.

[0138] The rotation of the check cam 95 reverses the rotation of the shift drum 87, returning it to the position shown in Figure 9. This return allows the first clutch ring 33 to receive further axial force, for example, from the movement biasing mechanism 117 provided between the first clutch ring 33 and the output shaft 5, enabling it to correctly engage with the first engagement position.

[0139] Here, the movement biasing mechanism 117 includes, for example, a check ball 119 provided on the output shaft 5 side and biased radially outward by a spring (not shown). The check ball 119 is configured to contact an inclined surface formed on the inner circumference of the first clutch ring 33. The inclined surface is formed on both sides in the axial direction of the first clutch ring 33. A similar movement biasing mechanism is also provided between the second clutch ring 35 and the output shaft 5 with the same structure.

[0140] Figure 12 is a diagram showing the relationship between the meshing state of the dog teeth and the position of the shift pin relative to the drum groove, relating to a comparative example. Figure 13 is a diagram showing the relationship between the meshing state of the dog teeth and the position of the shift pin relative to the drum groove, relating to Example 2.

[0141] Figures 12 and 13 summarize the operation of Example 2, along with a comparative example.

[0142] In both FIG. 12 and FIG. 13, the operations of each part are simply illustrated in a four-row and three-column table. The first row shows the relationship between the shift drum (drum groove) and the shift pin, the second row shows the check mechanism, the third row shows the dog clutch (exploded view), and the fourth row shows the shift drum and the dog clutch (exploded view).

[0143] In both FIG. 12 and FIG. 13, the first column shows the downshift when the rotational speed N1 < N2, the second column shows the successful downshift when the rotational speed N1 > N2, and the third column shows the failed downshift state when the rotational speed N1 > N2.

[0144] In the comparative example of FIG. 12, in the case of a downshift when N1 < N2, even if the shift pin 83 is guided to the cam peak point 115 by the rotation of the shift drum 87, the dog teeth 17 and 33 engage at the first engagement position by the drive engagement surfaces 103 and 109, so the unreasonable axial force P described in FIG. 6 does not occur.

[0145] In the comparative example of FIG. 12, in the case of a successful downshift when N1 > N2, even if the shift pin 83 is guided to the cam peak point 115 by the rotation of the shift drum 87, the dog tooth 33 immediately moves to the first engagement position and engages at the coast engagement surfaces 107 and 111, so the unreasonable axial force P described in FIG. 6 does not occur.

[0146] In the comparative example of FIG. 12, in the case of a failed downshift when N1 > N2, if the engagement fails even if the shift pin 83 is guided to the cam peak point 115 by the rotation of the shift drum 87, the unreasonable axial force P described in FIG. 6 occurs.

[0147] In contrast, in the second embodiment, it operates as shown in FIG. 13. When there is a downshift when N1 < N2 or a successful downshift when N1 > N2 in FIG. 13, there is no significant difference from the comparative example of FIG. 12.

[0148] In the downshift failure when N1 > N2 shown in Figure 13, the shift pin 83 is positioned in front of the cam lobe apex 115, generating an axial force P as described above. However, the thrust of the shift pin 83 presses against the cam lobe of the shift drum 87, causing the shift drum 87 to rotate and releasing the thrust of the shift pin 83. Furthermore, the action of the check mechanism 93 and the movement biasing mechanism allows the dog teeth 17a and 33b to complete engagement to their first engagement positions at the next engagement timing. [Explanation of symbols]

[0149] 1. Transmission 3 Input axes 5 Output shaft 7 1st gear 9. 1st gear (the other rotating member) 11. 2nd gear (the other rotating member) 13 2nd gear 15 3rd gear 17. 3rd gear (the other rotating component) 19. 4th gear (the other rotating member) 21 4th gear 23. 5th gear (the other rotating component) 25 5-speed gear 27. 6-speed gear (the other rotating component) 29 6-speed gear 31. Mechanism of meshing 33. First clutch ring (one of the rotating members) 35. Second clutch ring (one of the rotating members) 37. Third clutch ring (one of the rotating members) 33a, 33b, 35a, 35b, 37a, 37b, 9a, 11a, 17a, 19a, 23a, 27a dog teeth 39 Shift mechanism 41 Waiting mechanism 43a Input axis sensor (sensor) 43b Output axis sensor (sensor) 45 Control Unit 57 Contact plate (transmission part) 58 Interlocking rod (transmission section) 59 Elastic body (transmission part) 60 Arm connection section 61 Shift drive arm 65 Release mechanism

Claims

1. One rotating member that can be shifted in the axial direction, A second rotating member for transmitting torque between the first rotating member and the second rotating member, Each of the aforementioned rotating members is provided with a dog tooth that meshes in the rotational direction to transmit the torque, A shift mechanism that shifts one of the rotating bodies by a shift operation to engage the dog teeth, The shift mechanism is provided with a waiting mechanism that keeps the shift movement of one of the rotating bodies due to the shift operation in place, A pair of sensors for separately detecting the rotational position of the dog teeth of one and the other rotating member, A control unit calculates the meshing timing for the dog teeth to mesh without colliding based on the rotational position detected by the pair of sensors, and releases the standby of the waiting mechanism. Equipped with, The aforementioned waiting mechanism comprises a transmission unit, a shift drive arm, and a release mechanism. The transmission unit transmits the operating force of the shift mechanism through the interposition of an elastic body. The shift drive arm operates with the operating force transmitted through the transmission unit. The release mechanism stops the movement of the shift drive arm in a releaseable manner, accumulates the operating force in the elastic body, and allows the control unit to perform the release. Meshing mechanism.

2. The meshing mechanism according to claim 1, The control unit releases the standby of the standby mechanism while reducing the rotational difference or input torque between the one and the other rotating members. Meshing mechanism.

3. The meshing mechanism according to claim 1 or 2, The aforementioned rotating member is a clutch ring provided on the input shaft or output shaft. The other rotating member is one of the normally meshing variable speed gears provided on the input shaft or output shaft. When the dog teeth of the clutch ring engage with the dog teeth of one of the transmission gears, torque is transmitted between the input and output shafts via the constantly engaged transmission gear. Meshing mechanism.

4. The meshing mechanism according to claim 1 or 2, The sensor comprises an input axis sensor that detects rotation pulses of the input axis and an output axis sensor that detects rotation pulses of the output axis. Meshing mechanism.

Images