JP6459419B2 - Vehicle transmission - Google Patents

Description

  The present invention relates to a transmission for a vehicle that transmits a driving force from a crankshaft through a plurality of gears.

  An engine mounted on a vehicle such as a motorcycle includes a transmission that transmits a driving force of a crankshaft to a driving wheel via a clutch mechanism. Such a transmission includes a counter shaft (input shaft) and a drive shaft (output shaft) extending in parallel with the vehicle width direction, and a plurality of transmission gears mounted on each shaft, and changes the combination of meshing transmission gears. Shifting with. In such a transmission, as disclosed in Patent Document 1, the number of shift stages is often set to six.

  On the other hand, as disclosed in Patent Document 2, in a rough terrain vehicle (for example, a four-wheel buggy), a sub-transmission is used in addition to a normal transmission in order to widen the range of the gear ratio. Yes. In Patent Document 2, a normal transmission and a sub-transmission are provided with two drive shafts, and gears that mesh with each drive shaft are provided to perform sub-transmission.

JP 2005-127392 A JP-A 61-189347

  In transmissions, the number of gears is expected to increase in the future for reasons such as improved fuel efficiency. As a configuration for increasing the number of stages, a configuration is provided that includes a first transmission that transmits the driving force from the crankshaft and a second transmission that transmits the driving force from the first transmission to the driving wheel side. Can be considered. In this configuration, each of the first and second transmissions includes a plurality of transmission gears and a slide dog that is displaced between the transmission gears through operation of a shift mechanism. When the shift mechanism is operated to shift, the slide dog is displaced, and in each transmission, the slide dog is engaged with and joined to any of the plurality of transmission gears. In this way, the driving force is transmitted through the transmission gear joined to the slide dog of each transmission.

  However, in the above-described configuration, the slide dog of the first transmission and the slide dog of the second transmission may be displaced simultaneously, and each slide dog may be joined to the transmission gear. In this case, the joining of the slide dog and the transmission gear in the first transmission is exactly the same as the joining of the slide dog and the transmission gear in the second transmission. As a result, there is a problem that even if the joining with either one of the transmissions can be performed satisfactorily, the joining with any one of the other transmissions becomes difficult.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a vehicle transmission device that can suppress the occurrence of poor joining between a slide dog and a transmission gear.

A transmission for a vehicle according to the present invention is a transmission that transmits a driving force of a crankshaft from a first transmission to a drive wheel through a second transmission, and the first transmission includes a plurality of first transmission gears. When, and a first slide dot grayed selectively joined to any of a plurality of said first transmission gear, the second transmission, the driving force of the first transmission gear is plural transmitted 2 and gear, and a second slide dots grayed selectively joined to one of the plurality of the second speed change gear, a shift mechanism for switching said first and second transmission gear for transmitting a driving force further The shift mechanism includes simultaneous joint avoiding means for differentiating a timing at which the first slide dog is joined to the first transmission gear and a timing at which the second slide dog is joined to the second transmission gear , The first slide In the neutral position, a first clearance is formed between the first slide dog and the first transmission gear, while in the neutral position of the second slide dog, the second slide dog and the second speed change gear. A second clearance is formed between the gears, and the simultaneous joint avoiding means includes the slide dogs and the transmission gears disposed so that the first clearance is smaller than the second clearance. configured characterized Rukoto.

According to this configuration, since the respective timings described above are made different by the simultaneous joining avoiding means, it is possible to suppress the occurrence of poor joining between the slide dog and the transmission gear due to the fact that the respective timings are the same. it can. Thereby, even if the first and second transmissions are used to increase the number of stages of the transmission, smooth shift change can be realized. Moreover, it is possible to avoid the joints in the first transmission and the joints in the second transmission from having the same timing with a simple configuration in which the clearances have the above-described relationship. Further, the first slide dog can be brought closer to the transmission gear than the second slide dog in the neutral position. Thus, in the same manner as described above, the first slide dog can be joined to the transmission gear before the second slide dog, and a change shock to the rear wheel is avoided when the first slide dog is joined. Can

  In the vehicle transmission of the present invention, the shift mechanism includes a shift cam having first and second lead grooves formed on the outer periphery, and the first and second lead grooves are inclined with respect to the rotation direction of the shift cam. Each of the first lead grooves is inclined at a first shift angle with respect to the rotation direction of the shift cam, and the first slide dog is displaced by the rotation of the shift cam. The first transmission gear to be joined is switched, and the inclined groove of the second lead groove is inclined at a second shift angle with respect to the rotation direction of the shift cam, and the second slide dog is displaced by the rotation of the shift cam. The second transmission gear to be joined is switched, and the simultaneous joining avoiding means includes the respective inclined grooves in which the first and second shift angles are set to different angles. It may be. According to this configuration, it is possible to avoid that the joining in the first transmission and the joining in the second transmission have the same timing by a simple configuration in which each shift angle is set to the above-described angle.

  In the vehicle transmission of the present invention, it is preferable that the first shift angle is larger than the second shift angle. According to this configuration, the displacement amount of the first slide dog can be larger than that of the second slide dog with respect to the rotation angle of the shift cam. As a result, when the shift cam is rotated and the first and second slide dogs are switched from the non-joined state to the joined state with respect to the speed change gear, the first slide dog is connected to the speed change gear before the second slide dog. Can be joined. As a result, the change shock to the rear wheel only occurs once when the second slide dog is joined, and the occurrence of the change shock to the rear wheel when the first slide dog is joined can be avoided.

  According to the vehicle transmission device of the present invention, it is possible to suppress the occurrence of poor joint between the slide dog and the transmission gear by the simultaneous joint avoidance means.

It is a right view of the crankcase provided with the transmission for vehicles concerning this embodiment. It is the conceptual diagram which abbreviate | omitted and simplified the one part structure of FIG. FIG. 3 is a simplified cross-sectional view cut along a plane passing through O1, O2, O3, O4, and O5 of FIG. 2. FIG. 3 is a simplified cross-sectional view cut along a plane passing through O3, O7, O6, O8, and O4 of FIG. 2. It is an outer diameter expansion | deployment figure of a shift cam. It is an outer diameter expanded view of the shift cam for demonstrating the joining timing of the slide dog and transmission gear based on this Embodiment. It is the elements on larger scale of FIG. It is the elements on larger scale similar to FIG. 7 of the shift cam which concerns on a comparative example.

  Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. In the following, an example in which the vehicle transmission of the present invention is applied to a motorcycle will be described, but the application target is not limited to this and can be changed. For example, the vehicle transmission apparatus according to the present invention may be applied to a four-wheeled vehicle, an outboard motor, or the like. With reference to FIG.1 and FIG.2, the transmission for vehicles is demonstrated. FIG. 1 is a right side view of a crankcase provided with a vehicle transmission, and FIG. 2 is a conceptual diagram in which a part of the configuration of FIG. 1 is omitted and simplified. In the following drawings, the front of the vehicle is indicated by an arrow FR, the rear of the vehicle is indicated by an arrow RE, the left side of the vehicle is indicated by an arrow L, the right side of the vehicle is indicated by an arrow R, and the vehicle width direction is indicated by an arrow W.

  As shown in FIG. 1, a crankshaft 11 is disposed in front of the crankcase 10, and the crankshaft 11 has a rotation shaft disposed in parallel to the vehicle width direction (the direction orthogonal to the plane of FIG. 1). . Further, a transmission 20 is disposed in the rear side of the crankcase 10. As shown also in FIG. 2, the transmission 20 is adjacent to the first transmission 21 disposed behind the crankshaft 11, the rear of the first transmission 21, and arranged side by side with the first transmission 21. The second transmission 22 is disposed, and a single shift mechanism 23 is disposed at an adjacent position below the first and second transmissions 21 and 22.

  FIG. 3 is a simplified cross-sectional view cut along a plane passing through points O1, O2, O3, O4, and O5 in FIG. As shown in FIG. 3, a primary drive gear 12 is integrally provided at one end (right end) of the crankshaft 11 so as to rotate integrally. The first transmission 21 includes a first counter shaft (first input shaft) 25 and a first drive shaft (first output shaft) 26. The second transmission 22 includes a second counter shaft (second input shaft) 27 and a second drive shaft (second output shaft) 28. Each of the shafts 25 to 28 is disposed in parallel to the vehicle width direction like the crankshaft 11, and both ends thereof are rotatably supported by the crankcase 10 (see FIG. 1) via bearings 30.

  Here, returning to FIGS. 1 and 2, the points O <b> 1 to O <b> 5 indicate the axial center positions of the crankshaft 11, the first countershaft 25, the first driveshaft 26, the second countershaft 27, and the second driveshaft 28. . When the center O1 of the crankshaft 11, the center O2 of the first counter shaft 25, and the center O5 of the second drive shaft 28 are viewed in their extending directions (when the transmission 20 is viewed from the side), The positions of the centers O1, O2, and O5 are arranged along substantially the same straight line indicated by a two-dot chain line in FIG. Thereby, simplification of the layout of these shafts 11, 25, 28 can be achieved. A first counter shaft 25 is disposed above the first drive shaft 26, and a second drive shaft 28 is disposed above the second counter shaft 27. The first counter shaft 25 and the second drive shaft 28 are arranged side by side. As a result, the four shafts 25 to 28 are arranged in a state of being densely packed in the front-rear direction and the vertical direction, and the transmission 20 can be reduced in size in the same direction.

  Returning to FIG. 3, a primary driven gear 32 that meshes with the primary drive gear 12 is rotatably provided on the first counter shaft 25. An input-side outer case (clutch housing) 34 of the clutch mechanism 33 is fixed to the primary driven gear 32 so as to rotate together. On the other hand, an output side inner hub 35 of the clutch mechanism 33 is fixed to one end side of the first counter shaft 25. The outer case 34 and the inner hub 35 are connected to each other through a plurality of friction plates so as to be intermittently operated, whereby the driving force from the crankshaft 11 is transmitted to the first countershaft 25 via the clutch mechanism 33. Is done.

  The first transmission 21 further includes four first input-side transmission gears provided on the first countershaft 25 and having different numbers of teeth. The first input side transmission gears are, in order from the right, a first input side first speed gear 37a, a first input side third speed gear 37c, a first input side fourth speed gear 37d, and a first input side second speed gear 37b. . Further, the meshing pitch circle diameter increases in the order of the first input side first speed gear 37a, the first input side second speed gear 37b, the first input side third speed gear 37c, and the first input side fourth speed gear 37d. These gears 37a to 37d are spline-fitted or integrally formed with the first counter shaft 25, rotate integrally with the first counter shaft 25, and are fixed so as not to move in the axial direction.

  The first transmission 21 further includes four first output side transmission gears (first transmission gears) provided on the first drive shaft 26 with different numbers of teeth. The first output side transmission gears are, in order from the right, a first output side first speed gear 38a, a first output side third speed gear 38c, a first output side fourth speed gear 38d, and a first output side second speed gear 38b. . Further, the meshing pitch circle diameter becomes smaller in the order of the first output side first speed gear 38a, the first output side second speed gear 38b, the first output side third speed gear 38c, and the first output side fourth speed gear 38d. These gears 38a to 38d are rotatably provided to the first drive shaft 26 so as to be able to idle and are mounted so as not to move in the axial direction. The gears 38a to 38d on the first output side always mesh with the gears 37a to 37d on the first input side.

  A reduction drive gear 40 is fixed to one end (left end) side of the first drive shaft 26 so as to rotate integrally. On the other hand, a reduction driven gear 41 is fixed to one end (left end) side of the second countershaft 27 so as to rotate integrally. The reduction drive gear 40 and the reduction driven gear 41 mesh with each other, and the driving force of the first drive shaft 26 is transmitted to the second countershaft 27 via these gears 40 and 41. Here, the reduction drive gear 40 and the reduction driven gear 41 constitute a transmission mechanism.

  The second transmission 22 further includes two second input side transmission gears (second transmission gears) provided on the second countershaft 27 and having different numbers of teeth. The second input side transmission gears are, in order from the right, a second input side first speed gear 43a and a second input side second speed gear 43b. These gears 43a and 43b are rotatably provided to the second countershaft 27 so as to be able to idle, and are mounted so as not to move in the axial direction.

  The second transmission 22 further includes two second output side transmission gears provided on the second drive shaft 28 with different numbers of teeth. The second output side transmission gears are, in order from the right, a second output side first speed gear 44a and a second output side second speed gear 44b. These gears 44a and 44b are spline-fitted or integrally formed with the second drive shaft 28, rotate integrally with the second drive shaft 28, and are fixed so as not to move in the axial direction. The gears 44a and 44b on the second output side are always meshed with the gears 43a and 43b on the second input side.

  A drive sprocket 46 is provided at one end (left end) of the second drive shaft 28. The drive sprocket 46 is connected to a driven sprocket (not shown) provided on a drive wheel (not shown) via a drive chain 47, and the drive force of the second drive shaft 28 is driven to the drive wheel side by this chain drive. To communicate.

  Here, the first drive shaft 26 is provided with right and left first slide dogs 51 and 52, and the second countershaft 27 is provided with a second slide dog 53. The right first slide dog 51 is disposed between the first output side first speed gear 38a and the first output side third speed gear 38c, and is selectively joined thereto. The left first slide dog 52 is disposed between the first output side fourth speed gear 38d and the first output side second speed gear 38b, and selectively joins them. The right and left first slide dogs 51 and 52 are spline-fitted to the first drive shaft 26, rotate integrally with the first drive shaft 26, and are mounted so as to be movable in the axial direction. A dog clutch 55 is integrally formed on the side surface of the first slide dog 51 on the right side and the side surfaces of the first output side first speed gear 38a and the first output side third speed gear 38c. Yes. Also, the dog clutch 56 similar to the above is integrally formed on the side surface of the left first slide dog 52 and the side surfaces of the first output side fourth speed gear 38d and the first output side second speed gear 38b. In the first drive shaft 26, the gears 38 a to 38 d meshed with the dog clutches 55 and 56 of the right and left first slide dogs 51 and 52, and the first input side transmission gears 37 a to 37 d meshed with the gears 38 a to 38 d. Thus, the driving force from the first counter shaft 25 is transmitted.

  A second slide dog 53 is provided between the second input side first speed gear 43 a and the second input side second speed gear 43 b of the second countershaft 27. The second slide dog 53 is selectively joined to the second input side first speed gear 43a and the second input side second speed gear 43b. The second slide dog 53 is spline-fitted to the second countershaft 27, rotates integrally with the second countershaft 27, and is mounted so as to be movable in the axial direction. A dog clutch 57 similar to the above is integrally formed on the side surface of the second slide dog 53 and the side surfaces of the second input side first speed gear 43a and the second input side second speed gear 43b. In the second countershaft 27, the second drive shaft 28 is connected to either the gear 43a, 43b engaged with the dog clutch 57 of the second slide dog 53 or the second output side transmission gear 44a, 44b engaged therewith. Transmits driving force.

4 is a simplified cross-sectional view cut along a plane passing through O3, O7, O6, O8, and O4 of FIG. As shown in FIG. 4, between the dog clutch 55, 56 of each first slide dot grayed 51, the dog clutch 55, 56 of each first output side gear 38a~38d meshing with the dog clutch 55, 56 Is formed with a first clearance C1. In this embodiment, the left and right sides of the first slide dot grayed 51, first clearance C1 is formed a total of four positions located in the later-described neutral position of the first slide dot grayed 51, All the first clearances C1 are set to the same size.

The dog clutch 57 of the second slide dots grayed 53, the dog clutch 57 and meshing the second input side gear 43a, between the dog clutch 57 and 43b, the second clearance C2 is formed. Each second clearance C2 which is formed on the left and right sides of the second slide dot grayed 53 in later-described neutral position of the second slide dots grayed 53, it is set to the same size. The second clearance C2 and the first clearance C1 are different, and the first clearance C1 is formed smaller than the second clearance C2. Here, when the clearances C1 and C2 become 0 (zero) due to the movement of the slide dogs 51 to 53, the dog clutches 55 to 57 can be engaged with each other.

  Next, the configuration of the shift mechanism 23 will be described with reference to FIGS. As shown in FIG. 1, the shift mechanism 23 includes a shift pedal shaft 60, a shift drive plate 61, a shift cam 62, and a shift pedal arm (not shown). Further, as shown in FIGS. 2 and 4, the shift mechanism 23 includes right and left first shift forks 63 and 64, a second shift fork 65, and first and second shift shafts 67 and 68. Have. 1 and 2, points O6 to O8 indicate the axial center positions of the first shift shaft 67, the shift cam 62, and the second shift shaft 68.

  The first and second shift shafts 67 and 68 are arranged in parallel to the vehicle width direction. The first shift shaft 67 is provided at a position below the first drive shaft 26, and the second shift shaft 68 is provided at a position below the second counter shaft 27. The first and second shift forks 63 and 64 are attached to the first shift shaft 67 so as to be slidable in the axial direction, and the third shift fork 65 is attached to the second shift shaft 68 so as to be slidable in the axial direction. ing. The right and left first shift forks 63, 64 and the tip of the second shift fork 65 (not shown in FIG. 4) have a bifurcated shape, and the right and left first slide dogs 51, 52, the second slide dog. 53 is engaged. The right and left first shift forks 63 and 64 and the second shift fork 65 have right and left first pins 63a and 64a and a second pin 65a at their bases, and these pins 63a, 64a and 65a are provided with a shift cam 62. Are received in right and left first lead grooves 71 and 72 and a second lead groove 73 described later.

  The shift cam 62 is rotationally operated stepwise via a shift pedal shaft 60 and a shift drive plate 61 in conjunction with a shift operation of a shift pedal arm (not shown). The shift cam 62 is disposed in parallel with the shafts 26 and 27 in the vicinity of the lower side of the first drive shaft 26 and the second counter shaft 27 and is pivotally supported. The shift cam 62 is, for example, a cylindrical cam cast in a hollow shape, and right and left first lead grooves 71 and 72 and a second lead groove 73 are formed on the outer peripheral surface as three lead grooves. The right and left first lead grooves 71 and 72 and the second lead groove 73 extend in the circumferential direction of the shift cam 62 and are spaced apart in the axial direction of the shift cam 62. A right first pin 63a is received in the right first lead groove 71, a left first pin 64a is received in the left first lead groove 72, and a second pin 65a is slidable in the second lead groove 73. It is accepted.

  FIG. 5 is a development view of the shift cam. The numbers on the surface of the shift cam 62 in FIG. 5 indicate the positions of the pins 63a, 64a, 65a at the gear positions of the numbers. In the circumferential direction of the shift cam 62 (vertical direction in FIG. 5), the number in the second lead groove 73 is the angle α in FIG. 5 with respect to the number (gear position) in the right and left first lead grooves 71 and 72. The corresponding position is displaced downward. In the present embodiment, the neutral (N) is positioned lower than the first speed.

Each of the lead grooves 71 to 73 has parallel grooves 71 a, 72 a, 73 a extending in parallel to the rotation direction (circumferential direction) of the shift cam 62, and extends in a direction inclined with respect to the rotation direction of the shift cam 62. The existing portions are inclined grooves 71b, 72b, 73b. In the lead grooves 71 to 73, the parallel grooves 71a, 72a, and 73a between the gear positions do not change the left and right positions of the pins 63a, 64a, and 65a even if the shift cam 62 is rotated to change speed. On the other hand, in the inclined grooves 71b, 72b, and 73b between the gear positions, when the shift cam 62 is rotated to change speed, the left and right positions of the lead grooves 71 to 73 are displaced at the positions where the pins 63a, 64a, and 65a are received. . Therefore, by rotating the shift cam 62 by a predetermined rotation amount, the left and right positions of the lead grooves 71 to 73 are displaced, and the shift forks 63 to 65 move in the axial direction (left and right direction). Accordingly, to move to selectively axially each slide dot grayed 51-53 engaged with the shift forks 63 to 65, each slide dot grayed 51 to 53 are switched gears to be joined.

  The inclined grooves 71 b and 72 b of the right and left first lead grooves 71 and 72 are inclined at a first shift angle θ 1 with respect to the rotation direction of the shift cam 62. The inclined groove 73 b of the second lead groove 73 is inclined at the second shift angle θ <b> 2 with respect to the rotation direction of the shift cam 62. The first shift angle θ1 and the second shift angle θ2 are different, and the first shift angle θ1 is formed larger than the second shift angle θ2.

  In the right first lead groove 71, the position of the pin 63a in the axial direction becomes the neutral position Np at the neutral (N) and the third, fourth, seventh, and eighth speeds. At this time, the first clearance C1 (see FIG. 4) on both the left and right sides of the first slide dog 51 is disposed at a neutral position where the values are the same, and the first output side first speed gear 38a and the first output side third speed gear 38c. It becomes non-contact with both. Therefore, both the first output side first speed gear 38a and the first output side third speed gear 38c are idle with respect to the first drive shaft 26. In the first lead groove 71 on the right side, in the first and second speeds, the axial position of the pin 63a is shifted to the right, and the right first slide dog 51 is joined to the first output side first speed gear 38a via the dog clutch 55. Is done. Accordingly, the driving force is transmitted from the first counter shaft 25 to the first drive shaft 26 via the first input side first speed gear 37a and the first output side first speed gear 38a. In the right first lead groove 71, at the fifth and sixth speeds, the axial position of the pin 63a is shifted to the left, and the right first slide dog 51 is joined to the first output side third speed gear 38c via the dog clutch 55. Is done. Accordingly, the driving force is transmitted from the first counter shaft 25 to the first drive shaft 26 via the first input side third gear 37c and the first output side third gear 38c.

  In the left first lead groove 72, the position of the pin 64a in the axial direction becomes the neutral position Np at the neutral (N) and the first, second, fifth, and sixth speeds. At this time, the first clearance C1 (see FIG. 4) on both the left and right sides of the left first slide dog 52 is disposed at a neutral position where the same value is obtained, and the first output side fourth speed gear 38d and the first output side second speed gear are arranged. It becomes non-contact with both of 38b. Accordingly, both the first output side fourth speed gear 38d and the first output side second speed gear 38b are idle with respect to the first drive shaft 26. In the left first lead groove 72, at the third and fourth speeds, the axial position of the pin 64a is shifted to the left, and the left first slide dog 52 is joined to the first output side second speed gear 38b via the dog clutch 56. Is done. Accordingly, the driving force is transmitted from the first counter shaft 25 to the first drive shaft 26 via the first input side second speed gear 37b and the first output side second speed gear 38b. In the left first lead groove 72, in the seventh and eighth speeds, the axial position of the pin 64a is shifted to the right, and the left first slide dog 52 is joined to the first output side fourth speed gear 38d via the dog clutch 56. Is done. Accordingly, the driving force is transmitted from the first counter shaft 25 to the first drive shaft 26 via the first input side fourth gear 37d and the first output side fourth gear 38d.

  In the second lead groove 73, at the neutral (N) and the first, third, fifth, and seventh speeds, the axial position of the pin 65a is shifted to the right, and the second slide dog 53 is moved via the dog clutch 57. It is joined to the 2-input side 1st gear 43a. Accordingly, the driving force is transmitted from the second counter shaft 27 to the second drive shaft 28 via the second input side first speed gear 43a and the second output side first speed gear 44a. In the second lead groove 73, in the second, fourth, sixth and eighth speeds, the axial position of the pin 65a is shifted to the left, and the third slide dog 53 is connected to the second input side second speed via the dog clutch 57. Joined to the gear 43b. Accordingly, the driving force is transmitted from the second counter shaft 27 to the second drive shaft 28 via the second input side second speed gear 43b and the second output side second speed gear 44b. The neutral position Np of the pin 65a in the second lead groove 73 is a center position between the position where the axial direction of the pin 65a is to the right and the position to the left as described above. At this time, the second clearance C2 (see FIG. 4) on both the left and right sides of the second slide dog 53 is disposed at a neutral position where the values are the same, and the second input side first speed gear 43a and the second input side second speed gear 43b. It becomes non-contact with both.

  As described above, a shift using each gear is performed by each of the lead grooves 71 to 73. In the shift in the first transmission 21, every two stages (when an even stage is changed to an odd stage) as the number of stages is increased. The gear for transmitting the driving force changes, and the gear ratio gradually decreases. The first transmission 21 does not change the gear for transmitting the driving force when the number of steps is increased from an odd number to an even number, and when the number of steps is decreased from an even number to an odd number. . On the other hand, in the second transmission 22, every time the number of stages is changed, the gear for transmitting the driving force changes, and the odd-numbered stage has a smaller gear ratio than the even-numbered stage. In the present embodiment, the number of gears of the first transmission 21 is set to four, the number of gears of the second transmission 22 is set to two, and the number of gears of the transmission 20 as a whole is multiplied by the number of gears. X2 = 8 steps. The gear ratio of the entire transmission 20 with respect to the gear ratio of the first and second transmissions 21 and 22 is as shown in Table 1 below.

  In the gear ratios shown in Table 1, when the number of gears is increased and the gear ratio of the second transmission 22 is increased from B2 to B1, the first and second transmissions 21 are set so that the gear ratio of the entire transmission 20 is reduced. , 22 are respectively set. As a result, the gear ratio can be gradually reduced as the number of steps is increased while the transmission device 20 is multistaged from the first to eighth speeds.

  Here, the drive force transmission path when shifting from the second speed to the third speed from the first to eighth speed gear positions will be described as an example.

  When the gear position is the second speed, as described above, the right first slide dog 51 is positioned to the right by the right first lead groove 71, and the left first slide dog 52 is neutral by the left first lead groove 72. It will be in the state located. In this state, the right first slide dog 51 and the first output side first speed gear 38a are joined via the dog clutch 56, and the first output side first speed gear 38a and the first drive shaft 26 rotate together. It becomes a state to do. Accordingly, the first output side first speed gear 38a and the first drive shaft 26 which are meshed with the first input side first speed gear 37a rotate, and the first counter shaft 25 passes through these gears 37a and 38a. A driving force is transmitted to the first drive shaft 26. The driving force of the first drive shaft 26 is transmitted to the second countershaft 27 through a reduction drive gear 40 and a reduction driven gear 41 that mesh with each other.

  At the second speed, the second slide dog 53 is positioned to the left by the second lead groove 73. In this state, the second slide dog 53 and the second input side second speed gear 43b are joined via the dog clutch 57, and the second input side second speed gear 43b and the second counter shaft 27 rotate integrally. It becomes. As a result, the second output side second speed gear 44b and the second drive shaft 28 which are meshed with the second input side second speed gear 43b rotate, and the second countershaft 27 passes through these gears 43b and 44b. A driving force is transmitted to the second drive shaft 28. The driving force of the second drive shaft 28 is transmitted to a drive wheel (not shown) such as a rear wheel through the drive sprocket 46 and the drive chain 47.

  When the gear position is changed from the second speed to the third speed, the right first slide dog 51 is positioned at the neutral position by the right first lead groove 71, and the left first slide dog 52 is moved to the left by the left first lead groove 72. It will be in the position. Accordingly, the connection between the right first slide dog 51 and the first output side first speed gear 38a is released, and the left first slide dog 52 and the first output side second speed gear 38b are switched to be joined. That is, in the first transmission 21, the gear for transmitting the driving force is switched to the first output side second speed gear 38b and the first input side second speed gear 37b, and the first countershaft is connected via these gears 37b and 38b. The driving force is transmitted from 25 to the first drive shaft 26.

  Further, at the third speed, the second slide dog 53 is positioned to the right by the second lead groove 73. Accordingly, the joining target of the second slide dog 53 is switched, the joining of the second slide dog 53 and the second input side second speed gear 43b is released, and the second slide dog 53 and the second input side first speed gear are released. 43a is joined. That is, in the second transmission 22, the gear for transmitting the driving force is switched to the second input side first speed gear 43a and the second output side first speed gear 44a, and the second countershaft is connected via these gears 43a and 44a. The driving force is transmitted from 27 to the second drive shaft 28.

  Next, the timing of engagement in each of the dog clutches 55 to 57 at the time of shifting from the second speed to the third speed will be described with reference to FIGS. 6 and 7. 6 and 7 are explanatory diagrams of the joining timing of the slide dog and the transmission gear according to the present embodiment. 6 is a development view of the shift cam, and FIG. 7 is a partially enlarged view of FIG. FIG. 6 shows the second lead groove 73 displaced by an angle α in order to align each gear position in the lateral direction with respect to the developed view of the shift cam of FIG. 5 for convenience of explanation. Further, the alternate long and short dash line passing through the center of each of the lead grooves 71 to 73 becomes a passage route at the center of the pins 63a, 64a and 65a.

  6 and 7, when the shift cam 62 is rotated to shift the speed from the second speed to the third speed, the pins 63a, 64a, 65a move downward in the lead grooves 71-73. Is done. In the second lead groove 73, the second pin 65a is displaced rightward by the inclined groove 73b. Then, when the second pin 65a passes through the position P1 that is separated to the left by the second clearance C2 from the neutral position Np, the connection between the second slide dog 53 and the second input side second speed gear 43b is released. Further, in the right first lead groove 71, the right first pin 63a is displaced leftward by the inclined groove 71b, and the right first pin 63a passes the position P2 separated from the neutral position Np by the first clearance C1. The joining of the 1 slide dog 51 and the first output side first speed gear 38a is released. At this time, in the left first lead groove 72, the left first pin 64a is maintained in the horizontal position by the parallel groove 72a.

  And in the center position Cp of 2nd speed and 3rd speed, all the pins 63a, 64a, 65a in each lead groove 71-73 are each arrange | positioned in the neutral position Np.

  Thereafter, when the rotation of the shift cam 62 proceeds, first, in the left first lead groove 72, the left first pin 64a is displaced leftward by the inclined groove 72b. When the left first pin 64a passes through the position P3 that is separated from the neutral position Np by the first clearance C1 to the left, each dog clutch 56 between the left first slide dog 52 and the first output side second gear 38b is engaged. Is done.

  At the timing when each dog clutch 56 is engaged, the amount of displacement of the second pin 65a in the right direction from the neutral position Np in the second lead groove 73 is smaller than the second clearance C2. Accordingly, the second slide dog 53 is not joined to any of the second input side gears 43a and 43b. After the dog clutches 56 are joined, the second pin 65a that is displaced in the right direction in the inclined groove 73b of the second lead groove 73 passes through a position that is separated to the right by the second clearance C2 from the neutral position Np. Thereby, each dog clutch 57 of the 2nd slide dog 53 and the 2nd input side 1st speed gear 43a is joined. That is, the dog clutch 57 between the second slide dog 53 and the second input side first gear 43a cannot be engaged while the second pin 65a is displaced rightward by W1 in FIG. 7 in the inclined groove 73b. be able to.

  As described above, at the time of shifting from the second speed to the third speed, the timing at which the left first slide dog 52 is joined to the first output side second speed gear 38b and the second slide dog 53 are the second input side 1 The timing of joining to the speed gear 43a can be made different. The reason why these timings are different is that the second clearance C2 is larger than the first clearance C1, and therefore the first slide on the left side of the second slide dog 53 after passing through the center position Cp between the second speed and the third speed. This is because the dog 52 can be joined earlier. Also, since the first shift angle θ1 of the inclined groove 72b is larger than the second shift angle θ2 of the inclined groove 73b, the left first slide dog 52 is displaced from the second slide dog 53 with respect to the rotation angle of the shift cam 62. The amount can be increased, that is, the displacement speed can be increased. Therefore, this also allows the left first slide dog 52 to be joined earlier than the second slide dog 53 after passing through the center position Cp between the second speed and the third speed. .

  Here, also in the shift from the third speed to the second speed, the timing of joining at the first slide dog 51 on the right side and joining at the second slide dog 53 can be made different. The description will be given below from the time after passing through the center position Cp between the second speed and the third speed described above by the rotation of the shift cam 62.

  From such time, the right first pin 63a in the inclined groove 71b in the right first lead groove 71 passes through the position P2 that is separated to the right by the first clearance C1 from the neutral position Np. Thereby, each dog clutch 55 of the right side first slide dog 51 and the first output side first speed gear 38a is joined. The rotation of the shift cam 62 proceeds from this joining, and while the second pin 65a is displaced leftward in the inclined groove 73b of the second lead groove 73 by W2 in FIG. 7, the second slide dog 53 and the second input side 2 Each dog clutch 57 with the speed gear 43b cannot be engaged. Then, after a predetermined time, the second pin 65a that is displaced leftward in the inclined groove 73b passes through a position P1 that is separated to the left by the second clearance C2 from the neutral position Np. Thereby, each dog clutch 57 of the 2nd slide dog 53 and the 2nd input side 2nd speed gear 43b is joined. Therefore, the right first slide dog 51 can be joined faster than the second slide dog 53 after passing through the center position Cp between the third speed and the second speed.

In the above description, the shift between the second speed and the third speed has been described. However, the shift between the second speed and the third speed in which both the first transmission 21 and the second transmission 22 are shifted. As for the shift between the fourth speed and the fifth speed, and between the sixth speed and the seventh speed, the joining at the first slide dog 51 on the right side or the first slide dog 52 on the left side and the second slide dog 53 It is possible to make the timing different from the joining at. Here, the structure which makes those timings differ is each inclination groove | channel 71b, 72b, 73b by which 1st and 2nd shift angle (theta) 1 and (theta) 2 were set to the different angle. Further, first and second clearances C1, C2 each are arranged differently slide dot grayed 51-53 and this and can joint gear 38 a to 38 d, 43a, 43 b are also included. Here, the simultaneous joining avoiding means of the present invention is configured by each of the configurations having different timings.

  FIG. 8 is a partially enlarged view similar to FIG. 7 of the shift cam according to the comparative example. As shown in FIG. 8, in each of the lead grooves 71 ′ to 73 ′ according to the comparative example, the shift angles θ of the inclined grooves 71 b ′, 72 b ′, and 73 b ′ are all set to the same angle. Further, the first and second clearances C1 and C2 in the above embodiment are all set to the same value as the clearance C in the comparative example. About another structure, it comprises the same structure as this Embodiment, attaches | subjects and demonstrates the same code | symbol.

  In the comparative example, when shifting from the second speed to the third speed, the center position Cp of the second speed and the third speed passes through the pins 63a, 64a, 65a by the rotation of the shift cam 62. Thereafter, the left first pin 64a in the inclined groove 72b 'in the left first lead groove 72' passes through the position P5 that is separated to the left by the clearance C from the neutral position Np. At the same time, the second pin 65a, which is displaced in the right direction in the inclined groove 73b 'in the second lead groove 73, passes through the position P6 that is separated to the right by the clearance C from the neutral position Np. Accordingly, the left first slide dog 52 moved through the left first pin 64a and the first output side second speed gear 38b are joined, and the second slide dog 53 moved through the second pin 65a and the second Joining to the 2-input side first-speed gear 43a is simultaneously performed.

  As described above, according to the present embodiment, unlike the comparative example, the joint timing at the first slide dogs 51 and 52 and the joint timing at the second slide dog 53 are determined by the simultaneous joint avoidance means described above. Can be shifted. Thereby, even if the joining with any one of the slide dogs can be performed satisfactorily, it is possible to suppress the occurrence of the joining failure that makes the joining with any one of the other slide dogs difficult. Therefore, even if the first and second transmissions 21 and 22 are shifted as in the present embodiment, the shift change can be smoothed.

  Further, at the time of shifting to move both the right and left first slide dogs 51 and 52 and the second slide dog 53, after both the slide dogs 51 to 53 have passed the neutral position Np, the second slide dog 53 The first slide dogs 51 and 52 can be joined earlier than the first slide dogs 51 and 52. In other words, when the first slide dogs 51 and 52 are switched from the non-joined state to the joined state with respect to any one of the first output side gears 38a to 38d, the second slide dog 53 has both the second input side gears 43a, 43b is not joined. By this non-joining, it is possible to avoid the occurrence of a change shock to the rear wheel when the first slide dogs 51 and 52 are joined, and the number of change shocks to the rear wheel is set to one time when the second slide dog 53 is joined. Can be.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, direction, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

For example, the number of shift stages of the first and second transmissions 21 and 22 may be changed as long as it is plural. For example, like the first transmission 21, the number of the second transmission gears of the second transmission 22 may be increased to four, and the number of gears of the transmission 20 as a whole may be 4 × 4 = 16. In this case, the second slide dog 53 is similarly a two-body and the first slide dot grayed 51,52. As described above, the slide dogs in the first and second transmissions 21 and 22 are increased or decreased according to the number of installed transmission gears.

  Moreover, the position of neutral (N) in FIG.5 and FIG.6 is not limited, For example, you may change between 1st speed and 2nd speed.

  In addition, as long as the transmission mechanism that transmits the driving force of the first drive shaft 26 to the second countershaft 27 functions in the same manner as the reduction drive gear 40 and the reduction driven gear 41, another configuration may be adopted. it can.

  In the simultaneous joining avoiding means, contrary to the above embodiment, the first shift angle θ1 is formed smaller than the second shift angle θ2, or the first clearance C1 is formed larger than the second clearance C2. May be. However, it is advantageous that the magnitude relationship between them is as in the above embodiment in that the number of change shocks described above can be reduced.

  The first and second transmissions 21 and 22 may include a slide dog in which the number of gears is an odd number and the number of gears that can be joined is one. The neutral position of the slide dog where the number of gears that can be joined is one is the position at the number of speeds at which the slide dog is not joined to the gear.

  As described above, the present invention has an effect that it is possible to suppress the occurrence of poor joining between the slide dog and the transmission gear, and in particular, the driving force of the crankshaft is driven by the plurality of transmissions to drive wheels. This is useful for transmissions that transmit to the side.

DESCRIPTION OF SYMBOLS 11 Crankshaft 20 Transmission 21 1st transmission 22 2nd transmission 23 Shift mechanism 38a 1st output side 1st gear (1st transmission gear, simultaneous joining avoidance means)
38b First output side second gear (first transmission gear, simultaneous joining avoiding means)
38c 1st output side 3rd speed gear (1st transmission gear, simultaneous joining avoidance means)
38d 1st output side 4th gear (1st transmission gear, simultaneous joining avoidance means)
43a 2nd input side 1st gear (2nd speed change gear, simultaneous joining avoidance means)
43b Second input second speed gear (second transmission gear, simultaneous joining avoiding means)
51 Right first slide dog (first slide dog, simultaneous joint avoidance means)
52 left first slide dog (first slide dog, simultaneous joint avoidance means)
53 Second slide dog (simultaneous joining avoidance means)
62 Shift cam 71 Right first lead groove (first lead groove)
71a Inclined groove (simultaneous joining avoidance means)
72 Left first lead groove (first lead groove)
72a Inclined groove (Simultaneous joining avoidance means)
73 Second lead groove 73a Inclined groove (simultaneous bonding avoidance means)
C1 First clearance C2 Second clearance Np Neutral position θ1 First shift angle θ2 Second shift angle

Claims (3)

A transmission that transmits a driving force of a crankshaft from a first transmission to a drive wheel through a second transmission,
Wherein the first transmission includes a plurality of first transmission gear, and a first slide dot grayed selectively joined to any of a plurality of said first transmission gear,
It said second transmission includes a plurality of second gear to which the driving force of the first transmission gear is transmitted, and a second slide dots grayed selectively joined to one of the plurality of the second transmission gear Prepared,
The shift mechanism further includes a shift mechanism for switching between the first and second transmission gears for transmitting a driving force, the shift mechanism including a timing at which the first slide dog is joined to the first transmission gear, and the second slide dog. Comprises a simultaneous joining avoiding means for differentiating the timing of joining to the second transmission gear ,
In the neutral position of the first slide dog, a first clearance is formed between the first slide dog and the first transmission gear, while in the neutral position of the second slide dog, A second clearance is formed between the second transmission gear and the second transmission gear;
The simultaneous joining avoidance means, wherein the first clearance vehicle transmission system wherein is disposed is configured with a respective slide dog and the respective transmission gear, characterized in Rukoto as smaller than the second clearance . The shift mechanism includes a shift cam having first and second lead grooves formed on the outer periphery,
Each of the first and second lead grooves includes an inclined groove extending in a direction inclined with respect to the rotation direction of the shift cam,
The inclined groove of the first lead groove is inclined at a first shift angle with respect to the rotational direction of the shift cam, and the first transmission gear is switched by displacing the first slide dog by the rotation of the shift cam,
The inclined groove of the second lead groove is inclined at a second shift angle with respect to the rotation direction of the shift cam, and the second transmission gear is switched by displacing the second slide dog by the rotation of the shift cam,
The vehicular transmission according to claim 1, wherein the simultaneous joining avoiding means includes the inclined grooves in which the first and second shift angles are set to different angles.   The vehicular transmission according to claim 2, wherein the first shift angle is formed larger than the second shift angle.

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