JP6251585B2 - transmission - Google Patents

Description

  The present invention relates to a transmission for shifting a vehicle, a construction machine, an agricultural vehicle, or the like.

  In general, in a vehicle transmission using a single clutch, the driving force is interrupted at the time of a shift, and a shift shock or an acceleration delay cannot be avoided. In addition, in a construction machine or agricultural machine having a large running resistance and a small speed energy, when the driving force is interrupted at the time of shifting, it may stop immediately and the shifting may be difficult.

  On the other hand, the transmission of the twin clutch is known as a driving force that is not interrupted and can suppress shift shock and acceleration delay.

  However, the twin clutch transmission has a problem that its structure is complicated and heavy.

  On the other hand, seamless shift transmissions are attracting attention as being able to suppress weight gain.

  The operation of the seamless shift transmission will be described below. Here, in order to simplify the description, a shift between the first speed and the second speed will be described.

  This seamless shift transmission has three first burettes and three second burettes engaged with the input shaft between the first gear and the second gear, and is configured to move according to the shift operation. . The 1st speed gear and the 2nd speed gear are formed with meshing teeth, and different complex faces are formed on both ends of the first and second burettes before and after the rotation direction.

  The first buret and the second burette are configured to move toward the first gear or the second gear via a spring with respect to the operation of the select fork.

  With such a configuration, for example, when shifting to the first speed gear, the three first burettes mesh with the meshing teeth of the first speed gear, and then the remaining three second burettes mesh with the meshing teeth.

  At the time of shifting to the second speed, the three second burettes mesh with the meshing teeth of the second speed gear, and then the remaining three first burettes mesh with the meshing teeth.

  With the first and second burettes having such complicated faces and the selection operation via the spring, the driving force is not interrupted, the shift shock and the delay in acceleration can be suppressed, and the weight can be reduced. .

  However, there is a problem that the structure including the first bullet and the second bullet is complicated and the number of parts increases.

June 2005 Racecar Engineering (www.racecar / engineering.com)

  The problem to be solved is that the driving force is not interrupted, the shift shock and acceleration delay can be suppressed and the weight can be reduced, but the structure is complicated.

In the present invention, the driving force is not interrupted, the shift shock and the delay in acceleration can be suppressed, the weight can be reduced, and the structure can be simplified. A plurality of supported speed change gears, and a plurality of clutches that are selectively connected to the drive force transmission shaft and output the speed change gear, and that can be selectively engaged with the speed change gear by a mesh clutch. A ring, a speed change operation portion that selectively operates the clutch ring, and a guide portion provided between the clutch ring and the driving force transmission shaft, the guide portion including a cam groove and The cam groove includes a cam protrusion that fits in the cam groove, and the cam groove includes a surface that is engaged with the cam protrusion in the rotational direction of the driving force transmission shaft and is inclined with respect to the axial direction. Shift by the operation of the shift operation section Stage and shifting the upper clutch ring of the simultaneous meshing Isle clutch ring plane inclined and the cam protrusion of the cam groove by the internal circulation torque by the inclination of the surface involved in the simultaneous engagement when had simultaneously meshed While allowing relative rotation, the clutch ring in the lower gear stage or the upper gear stage is caused to generate an axial force in the mesh release direction to release the mesh, and the clutch ring is engaged with the first gear in the axial direction with respect to the transmission gear. The engagement clutch is movable to a state where the engagement clutch is engaged at the engagement position and a state where the engagement clutch is engaged at a second engagement position where the engagement is shallower than the first engagement position. The second clutch is connected to the lower clutch or upper clutch ring when the lower gear and upper gear ring are simultaneously engaged by the operation of the speed change operation unit. A guide surface that generates an axial force in a disengagement direction by a coasting torque at a meshing position, and when the clutch ring is simultaneously meshed, It is characterized by having a mechanism for setting the meshing position.

  Since the present invention is the above-described means, the driving force is not interrupted, the shift shock and the delay in acceleration can be suppressed, the weight can be reduced, and the structure can be simplified.

It is a schematic sectional drawing which shows a transmission with a front differential apparatus. (Reference example) It is a principal part expanded sectional view of a transmission. (Reference example) It is an expanded view which shows a cam groove and a cam protrusion. (Reference example) It is an expanded view which shows a cam groove and a cam protrusion. (Reference example) It is a perspective view which shows the relationship between a clutch cam ring and a clutch ring. (Reference example) It is a perspective view which shows the relationship between a clutch cam ring and a clutch ring (reference example). It is a perspective view which shows a clutch cam ring. (Reference example) It is a perspective view which shows a clutch ring. (Reference example) It is the schematic which shows the relationship between a shift fork, a check part, and a meshing clutch. (Reference example) It is the schematic which shows the relationship between a shift fork, a check part, and a meshing clutch. (Reference example) It is a principal part expanded view of a clutch ring. (Reference example) FIG. 4 is a main part development view showing meshing of the meshing clutch, wherein (a) is a coast meshing position, and (b) is a standby meshing position. (Reference example) It is the schematic which shows 4th gear meshing | engagement of the transmission at the time of shift up. (Reference example) It is the schematic which shows the position of the disengagement stand-by of the 4-speed clutch ring of a transmission at the time of shift up. (Reference example) It is the schematic at the time of completion | finish of gear shifting to 5th speed. (Reference example) It is the schematic which shows that the 4th speed and the 5th speed are neutral at the time of downshift. (Reference example) It is an operation explanation of the drum groove at the time of shift up and shift down. (Reference example) It is a schematic sectional drawing which shows a transmission with a front differential apparatus. (Reference example) It is an expanded sectional view of a coupling part periphery. (Reference example) (A) is an enlarged front view of the outer plate of a coupling transmission part, (B) is an enlarged front view of the inner plate of a coupling transmission part. (Reference example) It is a schematic sectional drawing which shows a transmission with a front differential apparatus. (Reference example) It is a schematic sectional drawing which shows a transmission with a front differential apparatus. (Reference example) (A) is a schematic sectional view showing engagement of the pressure ring in the direction of arrows XXIIIA-XXIIIA in FIG. 22, (B) is a sectional view of the center ring, and (C) is a front view of the center ring. (D) is a front view of a pressure ring, (E) is sectional drawing of a pressure ring. (Reference example) It is a schematic sectional drawing which shows the application to the ER base transmission. (Reference example) It is sectional drawing which shows the drive meshing position in connection with the principal part of a meshing clutch. Example 1 It is sectional drawing which concerns on the principal part of the meshing clutch which concerns on a modification, and shows a drive meshing position. Example 1 (A) is a schematic cross-sectional view of one of the meshing teeth and the meshing teeth as viewed from the tangential direction of the clutch ring. B) is a sectional view taken along the line XXVIIB-XXVIIB in (A). Explaining the wear of the tooth of the meshing clutch, (A) is a schematic cross-sectional view of one of the meshing of the meshing tooth and the meshed tooth as seen from the tangential direction of the clutch ring, (B) is the meshing FIG. 4C is a schematic cross-sectional view of the engagement and disengagement state of the teeth and the engaged teeth as viewed from the tangential direction of the clutch ring, and FIG. 5C is a cross-sectional view taken along the line XXIIIXC-XXIIIXC of FIG.

  The purpose of the meshing clutch is the operation of the speed change operation unit with the purpose of preventing the driving force from being interrupted, suppressing the shift shock and delay in acceleration, reducing the weight, and enabling the structure to be simplified. This is realized by providing a guide surface for generating an axial force in the disengagement direction at the second engagement position in the clutch ring of the lower shift stage or the upper shift stage when the clutch ring of the lower shift stage and the upper shift stage are engaged at the same time.

  In the first embodiment of the present invention, when the lower shift gear and the upper shift clutch ring are simultaneously engaged by the operation of the shift operation portion, the shaft in the disengagement direction at the second engagement position with the lower shift gear or the upper shift clutch ring. The engagement clutch is provided with a guide surface that generates a force. Before the structure adopting the engagement clutch provided with this guide surface, for the sake of easy understanding, FIGS. The reference example of the present invention generally explains the structure and operation of the transmission, which is the premise of the first embodiment of the present invention, and then, will be described with reference to FIGS.

  FIG. 1 is a schematic sectional view showing a transmission according to a reference example of Embodiment 1 of the present invention together with a front differential device, and FIG. 2 is an enlarged sectional view of a main part of the transmission.

  As shown in FIGS. 1 and 2, the transmission 1 includes a solid main shaft 3, a counter shaft 5, and an idler shaft 7 as driving force transmission shafts. The main shaft 3 and the counter shaft 5 are rotatably supported on the transmission case 17 by bearings 9, 11, 13, 15 and the like. The idler shaft 7 is fixed to the mission case 17 side.

  A first speed gear 19, a second speed gear 21, a third speed gear 23, a fourth speed gear 25, a fifth speed gear 27, and a sixth speed gear 29 are relative to the main shaft 3 and the counter shaft 5 as a plurality of speed change gears. It is rotatably supported.

  The first gear 19 and the third gear 23 on the counter shaft 5 mesh with the output gears 31 and 33 of the main shaft 3, and the second gear 21, the fourth gear 25 and the fifth gear on the main shaft 3. The 27th and 6th speed gears 29 mesh with the input gears 35, 37, 39, and 41 of the counter shaft 5, respectively.

  The reverse idler 43 on the idler shaft 7 is disposed so as to be able to mesh with the output gear 44 on the main shaft 3 and the input gear 45 on the counter shaft 5 by axial movement.

  The first speed gear 19 and the third speed gear 23 are selectively coupled to the counter shaft 5 by the first meshing clutch 47, and the second speed gear 21, the fourth speed gear 25, the fifth speed gear 27, and the sixth speed gear 29 are The second and third meshing clutches 49 and 51 are selectively coupled to the main shaft 3. By this selective coupling, a variable speed output from the main shaft 3 to the counter shaft 5 is possible.

  The first to third meshing clutches 47, 49, 51 change the plurality of speed change gears to the upper speed by changing the plurality of first to third meshing clutches 47, 49, 51. It is like that.

  That is, the first speed gear 19, the second speed gear 21, the third speed gear 23, the fourth speed gear 25, the fifth speed gear 27, and the sixth speed gear 29, which are a plurality of speed change gears, are included in the first to third meshing clutches 47. , 49, 51 are arranged to change the speed.

  For example, the shift from the first gear 19 to the second gear 21 is performed by changing the plurality of first and second meshing clutches 47 and 49.

  The first to third meshing clutches 47, 49, 51 basically have the same structure, and include clutch cam rings 53, 55, 57, clutch rings 59, 61, 63, clutch rings 59, 61, 63 and clutch teeth 47a, 47b, 49a, 49b, 51a, 51b, 19a, 21a, 23a, 25a, 27a, 29a formed on the opposing surfaces of the first gear 19 to the sixth gear 29. .

  Therefore, the clutch rings 59, 61, 63 are engaged and moved in the axial direction of the main shaft 3 and the counter shaft 5, and the clutch teeth 47a, 47b, 49a, 49b, 51a, 51b, 19a, 21a, 23a, Connection for shifting output is performed by selective engagement of 25a, 27a, and 29a.

  The clutch cam rings 53, 55, 57 of the first to third meshing clutches 47, 49, 51 are formed with substantially V-shaped cam grooves 65, 67, 69. The clutch cam ring 53 of the first meshing clutch 47 is coupled to the counter shaft 5 by spline fitting or the like, and can rotate integrally. Clutch cam rings 55 and 57 of the second and third meshing clutches 49 and 51 are coupled to the main shaft 3 by spline fitting or the like, and can rotate integrally.

  The clutch rings 59, 61, 63 of the first to third meshing clutches 47, 49, 51 are fitted on the outer periphery of the clutch cam rings 53, 55, 57, and are movable in the axial direction. ing. The clutch rings 61, 63 selectively couple the second speed gear 21, the fourth speed gear 25, the fifth speed gear 27, and the sixth speed gear 29, which are transmission gears, to the main shaft 3, which is the driving force transmission shaft. A plurality of clutch rings 59 are provided to selectively output the first speed gear 19 and the third speed gear 23 that are transmission gears to the counter shaft 5 that is the driving force transmission shaft. There are several to do. On the inner periphery of the clutch rings 59, 61, 63, cam protrusions 71, 73, 75 having a circular cross section are formed as protrusions, and are fitted and guided in the cam grooves 65, 67, 69. Yes.

  The clutch ring 59 and the reverse idler 43 are formed with circumferential recesses 81 and 83 into which shift forks 77 and 79 described later are fitted. The input gear 45 is further formed on the outer periphery of the clutch ring 59. The clutch rings 61 and 63 are formed with circumferential ridges 89 and 91 into which shift forks 85 and 87 described later are fitted. On both sides of the clutch rings 59, 61, 63, the first speed gear 19, the second speed gear 21, the third speed gear 23, the fourth speed gear 25, the fifth speed gear 27, and the sixth speed gear 29 are selected. The second and higher gears are arranged so as to be selectively meshed with the transmission gears on both sides. That is, the first speed gear 19 and the third speed gear 23 are arranged on both sides of the clutch ring 59, the second speed gear 21 and the fifth speed gear 27 are arranged on both sides of the clutch ring 61, and the clutch ring 63 A four-speed gear 25 and a sixth-speed gear 29 are arranged on both sides.

  The first to third meshing clutches 47, 49, 51 are selectively operated by the speed change operation unit 93. The reverse idler 43 is also operated by the speed change operation unit 93.

  The transmission operation unit 93 is provided in the mission case 17 and includes a plurality of shift forks 77, 79, 85, 87, a plurality of shift rods 103, 105, 107, 109 and shift arms 111, 113, 115, 117. And a shift drum 119.

  Shift forks 77, 79, 85, 87 are provided for each of the first to third meshing clutches 47, 49, 51 and the reverse idler 43, and each meshing clutch 47, 49, 51, reverse idler 43 is linked.

  The shift rods 103, 105, 107 and 109 support the shift forks 77, 79, 85 and 87.

  Shift arms 111, 113, 115, 117 are coupled to each shift rod 103, 105, 107, 109.

  The shift drum 119 includes shift grooves 120, 121, 123, and 125, and the front end protrusions of the shift arms 111, 113, 115, and 117 are engaged with the shift grooves 120, 121, 123, and 125. .

  Uneven portions 127 and 129 and check portions 131 and 133 are provided between the shift forks 85 and 87 and the mission case 17 side. An uneven portion and a check portion having the same structure are also provided between the shift fork 99 side and the mission case 17 side, but the illustration is omitted.

  The concave and convex portions 127 and 129 are formed in the shift forks 95 and 97, and include mountain-shaped positioning concave portions 127a, 127b, 127c, 129a, 129b, and 129c. The positioning recesses 127a and 129a correspond to the neutral position, and the positioning recesses 127b, 127c, 129b and 129c correspond to the coast meshing positions.

  The check parts 131 and 133 are supported on the mission case 17 side, and the check balls 131a and 133a are urged by the check springs 131b and 133b to be engaged with the uneven parts 127 and 129 with an elastic force. By this engagement, the first to third meshing clutches 47, 49, 51 can be positioned to the neutral position and the coast meshing position.

  The output of the transmission 1 is performed from a front differential device 137 that meshes with the output gear 135 of the counter shaft 5.

  That is, when the shift drum 119 is rotationally driven by a shift motor (not shown) based on the manual operation signal of the shift lever or the accelerator opening and the vehicle speed signal by the operation of the accelerator pedal, the shift The shift rods 103, 105, 107, and 109 are selectively driven in the axial direction via any one of the shift arms 111, 113, 115, and 117 by the guides of the grooves 120, 121, 123, and 125.

  By selectively driving the shift rods 103, 105, 107, 109, the first to third meshing clutches 47, 49, 51 or the reverse idler via any of the shift forks 77, 79, 85, 87. 43 is selected. By this selection operation, the first speed gear 19 to the sixth speed gear 29 and the reverse idler 43 are selectively operated, and shift up, shift down, and reverse can be changed.

[Guide section]
When the gear shift lower unit and the gear shift upper step are simultaneously meshed with the gear shift operation unit 93 and the first to third gear clutches 47, 49, 51 by the operation of the gear shift operation unit 93, the output torque of the engine Regardless of the mechanism, the internal circulation torque that is inevitably generated by the mechanism causes the torque in the drive direction to act on the clutch ring at the upper speed of the shift to generate an axial force in the deeper meshing direction. Each stage is provided with a guide portion G that generates an axial force in the direction of releasing the meshing by moving the clutch in the neutral direction by the ting torque.

  As described above, the guide portion G includes the cam grooves 65, 67, 69 and the cam protrusions 71, 73, 75 in the first to third meshing clutches 47, 49, 51. The drive gear and the coasting torque at the coast engagement position of the first to third engagement clutches 47, 49, 51 by the cam grooves 65, 67, 69 and the cam protrusions 71, 73, 75 are the first speed gear. 19, 2nd speed gear 21, 3rd speed gear 23, 4th speed gear 25, 5th speed gear 27, 6th speed gear 29 are transmitted to the gear disengagement side rather than the coast meshing position. The meshing can be guided in the neutral direction by the torque in the tilting direction.

  Further, the guide portion G includes a moving force transmission mechanism M in the speed change operation portion 93, and a driving slope F described later is provided only on the positive driving torque transmission side of the first to third meshing clutches 47, 49, 51. ing.

  The drive slope F can generate a moving force that moves the clutch rings 59, 61, 63 of the first to third meshing clutches 47, 49, 51 to the disengagement standby position by the drive torque. The slope F may be provided on the gear side clutch teeth, and the same function can be obtained.

  The deep engagement state of the clutch rings 59, 61, 63 is the engagement state at the first engagement position of the first to third engagement clutches 47, 49, 51. On the other hand, the disengagement standby position is a state where the first to third engagement clutches 47, 49, 51 are engaged at a second engagement position where the engagement is shallower than the first engagement position. .

  In other words, in the present embodiment, the drive slope F is a mechanism for causing the clutch rings 59, 61, 63 to engage with the first to third engagement clutches 47, 49, 51 at the second engagement position. Configure.

  As will be described later, the driving slope F is formed at the tooth base on one side in the rotational direction of the clutch teeth 47a, 47b, 49a, 49b, 51a, 51b and the clutch teeth 19a, 21a, 23a, 25a, 27a, 29a. When transmitting the driving force, the clutch teeth 59a, 61b, and 63a are moved by guiding the other end of the clutch teeth 47a, 47b, 49a, 49b, 51a, 51b and the clutch teeth 19a, 21a, 23a, 25a, 27a, 29a. It is moved from the first meshing position to the second meshing position.

  3 and 4 are developed views showing cam grooves and cam protrusions, FIGS. 5 and 6 are perspective views showing the relationship between the clutch cam ring and the clutch ring, and FIG. 7 is the clutch cam ring. FIG. 8 is a perspective view showing a clutch ring.

  As shown in FIGS. 3 to 7, a plurality of cam grooves 65, 67, 69 are formed on the outer peripheral surface of the clutch cam ring 53, 55, 57 at equal intervals in the circumferential direction. The cam grooves 65, 67, and 69 are formed with V-shaped portions 65a, 67a, and 69a in the center portion in the axial direction including a portion corresponding to the neutral, and flat portions 65b, 67b, and 69b on both sides thereof. Is.

  For this reason, when the meshing clutches 47, 49, 51 are located at the non-standby position, the cam protrusions 71, 73, 75 are located at the flat portions 65b, 67b, 69b. , Neutral thrust does not occur and keeps meshing.

  The cam projections 71, 73, 75 project radially from the inner periphery of the clutch rings 59, 61, 63 at regular intervals in the circumferential direction, and are fitted and guided in the cam grooves 65, 67, 69, respectively. It is like that.

  Therefore, at the coast engagement positions of the first to third engagement clutches 47, 49, 51, the cam protrusions 71, 73, 75 are positioned at the flat portions 65b, 67b, 69b, and the driving torque and the coasting torque are set. Can be transmitted to the first gear 19, the second gear 21, the third gear 23, the fourth gear 25, the fifth gear 27, and the sixth gear 29.

  Since the cam projections 71, 73, 75 are located at the V-shaped portions 65a, 67a, 69a at the position where the first to third meshing clutches 47, 49, 51 are in the standby state, as shown in FIG. The meshing can be guided in the neutral direction by the direction torque.

  9 and 10 are schematic views showing the relationship between the shift fork, the check unit, and the meshing clutch, FIG. 11 is a developed view of the main part of the clutch ring, and FIG. 12 is a diagram showing the meshing of the meshing clutch. (A) is a coast part engagement position, (b) is a principal part expanded view which shows a standby mesh position. 9 to 12 describe the third meshing clutch. The same applies to the first and second meshing clutches, and a duplicate description is omitted.

  As shown in FIGS. 1 and 9 to 12, the third meshing clutch 51 includes clutch teeth 51 a and 51 b of the clutch ring 63 and clutch teeth 25 a and 29 a of the fourth speed gear 25 and the sixth speed gear 29. In the circumferential arrangement, there is a mutual interval larger than the tooth width. The circumferential meshing surfaces of the clutch teeth 51a, 51b, 25a, and 29a are inclined so that the roots of the teeth are slightly thinner.

  At the roots of the clutch teeth 51a and 51b of the clutch ring 63, the drive slope F is formed on the meshing surface that receives the drive torque.

  Therefore, when the third meshing clutch 51 is meshed with, for example, the sixth gear 29 and the driving torque is applied, the clutch ring 63 is moved by the driving slope F as shown in FIG. At this time, the recess 129b of the shift fork 87 shown in FIG. 10 pushes the ball 133a, and the spring 133b is pressurized and stores energy. This movement is allowed because the shift groove 125 is appropriately provided with axial play with respect to the guide of the shift arm 117. As a result of this movement, the clutch ring 63 becomes the disengagement standby position of FIGS. 10 and 12B, which has moved to the disengagement side from the coast engagement position of FIG. 9 and FIG. 12A.

  Next, when the driving torque changes in the coast direction, the teeth are pressed to the opposite side and are separated from the slope F shown in FIGS. For this reason, the elastic energy of the spring 133b results in the deep meshing state shown in FIGS. 9 and 12 (a) by the action of the recess 129b and the ball 133a. In this state, since the cam projection 75 shown in FIG. 2 is positioned on the flat portion 69 b on the axial end side of the cam groove 69, no thrust is generated in the clutch ring 63.

  As described above, in this embodiment, the recess 129b, the ball 133a, and the spring 133b of the shift fork 87 are engaged with only the clutch ring (59, 61, 63) at the lower gear stage when the driving force is transmitted. A mechanism for accumulating elastic energy for returning the rings (59, 61, 63) from the second meshing position to the first meshing position, and the mechanism provided on the speed change operation unit 93 side; Become.

  For the clutch ring 61, the recess 127b of the shift fork 85, the ball 131a, and the spring 131b constitute a mechanism for accumulating similar elastic energy.

  That is, when the driving force is transmitted to the shift operation unit 93 side when only one of the clutch ring (59, 61, 63) in the lower shift stage or the upper shift stage is engaged, the clutch ring (59, 61, 63) is transmitted. The structure is equipped with a mechanism for accumulating elastic energy and returning the clutch ring (59, 61, 63) from the second engagement position to the first engagement position by elastic energy during coasting torque. .

  On the other hand, when the shift to the upper shift stage is started, the shift drum 119 shown in FIG. 1 is rotated, so that the play of the shift arm 117 with respect to the guide of the shift arm 117 is eliminated by the shape of the shift groove 125 of the lower shift stage. The movement of the clutch ring 63 in the axial direction is restricted via the rod 109 and the shift fork 87, and the disengagement standby position is maintained even when coasting torque is applied. At this time, since the cam protrusion 75 moves from the flat portion 69 b of the cam groove 69 to the slope portion, when a coasting torque is applied to the lower gear due to the meshing of the upper gear, the cam groove 69 is neutralized by the slope of the cam groove 69. A thrust component moving in the direction can be obtained. Specific shift action will be described later.

  Therefore, the shift drum 119, the shift groove 125 (120, 123), the shift arm 117 (111, 115), the shift fork 87 (77, 85), and the clutch ring 63 (59, 61) The clutch ring (59, 61, 63) is moved from the second engagement position to the first engagement position at the time of the coasting torque in which the lower shift gear stage and the upper shift clutch ring (59, 61, 63) are simultaneously engaged. It becomes the structure provided with the mechanism which maintains the 2nd meshing position against the energy for returning to (1).

[Shift up 4th → 5th]
FIG. 13 is a schematic diagram showing the meshing of the 4-speed gear of the transmission at the time of shift-up, FIG. 14 is a schematic diagram showing the position of waiting for the separation of the 4-speed clutch ring of the transmission at the time of the shift-up, and FIG. FIG. 16 is a schematic diagram showing that the fourth speed and the fifth speed are neutral at the time of shifting down.
Here, for simplification of explanation, only the shift-up from the fourth speed (shift lower stage) to the fifth speed (shift upper stage) will be described. The same applies to the shift-up of other stages.

  FIGS. 13 to 15 show the movement at the time of shifting up and FIG. 16 shows the completion of the shifting down. Since drive torque is applied to the fourth-speed clutch teeth 25a in FIG. 13, the clutch ring 63 is in the disengagement standby position as shown in FIG. That is, the cam projection 75 of the clutch ring 63 at the fourth speed position is located on the slope of the cam groove 69. At this time, when a shift-up operation to the fifth speed is performed by the rotation of the shift drum 119, the shift groove 123 works, and the clutch ring 61 is moved via the shift arm 115, the shift rod 107, and the shift fork 85. Operated. By this operation, the clutch ring 61 is engaged with the fifth gear 27 and the fourth gear 25 and the fifth gear 27 are simultaneously engaged.

  At this time, coasting torque is generated on the 4th speed side and drive torque is generated on the 5th speed side due to the internal circulation torque caused by the mechanical engagement by simultaneous meshing regardless of the engine output torque. This torque is caused by the action of the inclined surfaces of the cam grooves 69 and 67, and the clutch ring 63 in the fourth speed position generates thrust in the neutral direction in the right side of the figure and the clutch ring 61 in the fifth speed position in the direction to deepen the engagement on the right side in the figure. Then, the respective clutch rings 63 and 61 are moved to predetermined positions, and the shift-up to the fifth speed is completed as shown in FIG.

  A feature of the embodiment of the present invention is that when the clutch rings 59, 61, 63 move in the axial direction, they rotate together with the main shaft 3 or the counter shaft 5 by the action of the inclined surfaces of the cam grooves 65, 67, 69. The rotation of the clutch rings 59, 61, 63 on the lower speed side relative to the cam rings 53, 55, 57 is delayed, and the rotation of the clutch rings 59, 61, 63 on the upper speed side is preceded. In such a situation, the relative speed of the gears 19a, 21a, 23a, 25a, 27a, 29a of the gears of the lower gear and the upper gear that rotate in such a situation is eliminated to allow double meshing, and a synchronizing action is generated to cause a gear change shock ease.

[Shifting up when the engine brake is working]
When shifting up when the engine brake is applied, the clutch ring 63 in the fourth speed position is shifted without being in the standby position. At this time, the clutch ring 61 is engaged with the fifth speed gear 27 by the shift-up operation, and further coasting torque is applied to the fourth speed. However, the clutch ring 63 at the fourth speed position is not at the disengagement standby position. No thrust component is generated.

  However, the coasting torque during engine braking has a smaller absolute value than the torque during acceleration, and the friction force acting on the meshing clutch is small. A strong thrust component is generated in the clutch ring 61 at the fifth speed position by the slope action of the cam groove 67.

  The thrust passes through the shift fork 85, the shift rod 107, the shift arm 115, the shift groove 115 and the shift groove 125 of the shift drum 119 at the fifth speed position, and then the shift rod 109 and the shift fork 87 at the fourth speed position. To the disengagement standby position side in the neutral direction on the right side of the figure. Therefore, even in such a case, there is no problem with shifting up. The shift groove 123 and the shift groove 125 are cut so as to perform such a cooperative operation, and the shift drum 119 rotates slightly through the shift groove 123 by the thrust force from the shift arm 115 side. The thrust force is transmitted to the shift arm 117 through the shift groove 125.

  Therefore, the mechanism for causing the clutch rings 59, 61, 63 to engage with the first to third engagement clutches 47, 49, 51 at the second engagement position is the clutches for the lower gear and the upper gear. The shift forks 77, 85, 87 of the rings 59, 61, 63, the shift rods 103, 107, 109, the shift grooves 120, 123, 125 of the shift drum 119, and the shift arms 111, 115, 117 The shift drum 119 is provided.

  Even when the drive torque is working, the clutch ring 63 is not positioned at the disengagement standby position without the slope F. However, even in this case, the clutch ring 63 can be forcibly moved in the neutral direction by transmission of force from the shift mechanism at the fifth speed position.

  For this reason, the slope F is not essential for the present invention, but is used for smoother shifting.

In this embodiment, the shift groove 120, 121, 123, 125 (cylindrical cam) of the shift drum 119 is used for the shift operation. The flat cam or each shift rod is driven by controlled hydraulic pressure, electric motor air pressure, or the like. Even so, the present invention is established.
[Shift down 5th gear → 4th gear]
When decelerating, there is no need for a seamless shift like during acceleration. This is because the deceleration is mainly handled by the brake, and the output from the engine is basically not related, so there is no problem even if the drive torque or engine brake torque from the engine is interrupted. For this reason, as in a normal manual transmission, first, the clutch ring 61 at the fifth speed position of the upper gear position is moved to the neutral position shown in FIG. 16 to cut off the power, and then the clutch ring 63 is changed to the fourth speed gear 25. Shifting down by meshing.

  Thus, the meshing state of FIG. 13 is obtained.

  As described above, the present embodiment is characterized in that the mode of meshing transition is different between shift-up and shift-down. This is due to the fact that the shift rings 61 and 63 of the upper shift stage and the lower shift stage are independent, and due to the cooperative shape of the shift grooves 125 and 123 of the cylindrical cam 119.

  Hereinafter, a mechanism for changing the shift mode between shift-up and shift-down will be described with reference to FIG. FIG. 17 is a diagram illustrating the operation of the drum groove during shift up and shift down.

[Shift up 4th → 5th]
At the 4th speed shown in FIG. 13, the shift arm 117 and the shift arm 115 at the 5th speed position are at a position 115a and a position 117a shown in FIG. When the shift drum 119 rotates to the front side in order to shift up, the shift arm 115 is moved from the position 115b1 to the positions 115b2 and 115c by the inclined surface 123a of the shift groove 123. At this time, double meshing occurs and the shift arm 117 is automatically moved from the position 117b1 to the position 117b2 by the action of the inclined surface of the cam groove 69 of the cam ring 57, and becomes neutral. Further, the shift drum 119 rotates to shift to the position 117C. This completes the shift-up from 4th gear to 5th gear.

[Shift down 5th gear → 4th gear]
When the clutch is engaged at the fifth speed, the shift fork 87 is held in the neutral position by the check portion 133 as shown in FIG. Even if the shift drum 119 rotates and the shift groove 125 is located at the position 117b2 in FIG. 17 with respect to the shift arm 117 and there is play in the axial direction, the check arm 133 causes the shift arm 117 to be neutral at the position 117b2. Retained.

  On the other hand, the shift arm 115 shifts from the position 115c to the position 115b1, and becomes neutral as shown in FIG.

  When the shift drum 119 further rotates, the shift fork 87 shifts from the position 117b2 to the position 117a, the clutch ring 63 engages with the clutch teeth 25a of the fourth gear 25, and the state shown in FIG. 13 is completed by shifting down.

  The transmission is the same as the gear shifting principle described above, but when the cam groove slope of the guide section G and the position of the slope F are opposite to the clutch teeth, the guide section By the action of G, the lower gear side can be guided in the direction in which the clutch ring engages more deeply, and the upper gear side can be guided in the neutral direction.

  This is because when the construction machinery, agricultural machinery, large trucks, etc. are traveling at a low speed, such as traveling on a muddy ground or climbing a hill, when the speed energy is small and the traveling resistance is large, a greater driving force is required, so a downshift is required. In such a situation, when shifting down with a normal meshing transmission, if the driving force is interrupted even for a short time, the vehicle stops, causing problems such as difficulty in climbing. According to the present invention, since the driving force can be changed without interruption, shifting can be easily performed and traveling can be maintained.

  The shift guide by the guide portion G of the transmission 1 can be configured only on the shift / up operation side or only on the shift / down operation side of the shift operation unit 93. In this case, the shift-down operation side or the shift-up operation side on the other side may be configured to change the clutch on / off and through the synchronized mesh mechanism.

[Elastic part and damping part]
18 to 20 relate to another reference example, FIG. 18 is a schematic cross-sectional view showing the transmission together with the front differential device, FIG. 19 is an enlarged cross-sectional view around the coupling portion, and FIG. The enlarged front view of the outer plate of a transmission part, (B) is an enlarged front view of the inner plate of a coupling transmission part. The overall basic configuration of the transmission of the first embodiment is the same as the reference example of FIGS. 1 to 17. In FIGS. 18 to 20, the same components as those of FIGS. The characteristic part will be further described.

  As shown in FIGS. 18 and 19, the transmission 1 of this reference example has a configuration in which the main shaft 3 performs drive input as a drive force transmission shaft in the same manner as described above. The main shaft 3 includes a hollow outer shaft 201 and a torsion bar 202 as an elastic portion. The torsion bar 202 absorbs a shift shock generated at the time of a shift in which the guide portion G functions by a torsional elastic force.

  The hollow outer shaft 201 has the transmission gears 21, 25, 27, 29 and the clutch rings 61, 63 arranged on the outer peripheral portion, and a through hole 205 is formed in the shaft core portion. Needle bearings 207 a and 207 b are provided for the through hole 205 at both ends of the hollow outer shaft 201. One end of the hollow outer shaft 201 protrudes outside the bearing 9, and a spline 201a is formed.

  The torsion bar 202 includes an input coupling portion 209 at one end portion of the torsion portion 203, and a coupling shaft portion 213 that couples a friction coupling transmission portion 211 as a damping portion to the other end portion. The frictional coupling transmission part 211 attenuates the vibration of the torsion bar 202 which is an elastic part, and also has a function of a torque limiter.

  The torsion part 203 is a part that generates a torsional reaction force, is formed to have a slightly small diameter with respect to the through hole 205, and is fitted and arranged so as to be relatively rotatable. Both ends of the torsion part 203 are supported by needle bearings 207a and 207b in the through hole 205 so as to be relatively rotatable.

  The input coupling portion 209 is formed to have a larger diameter than the torsion portion 203, and the input coupling portion 209 has a proximal end formed to be the same as the outer diameter of the outer shaft 201, and the outer shaft 201 has a mutual end face butt. Has been done. The distal end side of the input coupling portion 209 is formed with a slightly small diameter, and an input coupling spline 209a is formed on the distal end side. A taper shape or the like is formed between the proximal end of the input coupling portion 209 and the spline 209a.

  The coupling shaft portion 213 protrudes from the end portion of the outer shaft 201, and a spline 213a and a screw portion 213b are formed.

  As shown in FIGS. 19 and 20, the frictional coupling transmission unit 211 includes a case 215, a pressing plate 217, a multi-plate outer plate 219 and an inner plate 221, and is fastened by a nut 223.

  In the case 215, inner splines 215a and 215b are formed on the inner periphery of the side wall and the peripheral wall, respectively. The inner spline 215 a on the side wall is fitted to the spline 201 a of the outer shaft 201. The outer peripheral projection 219a of the outer plate 219 is engaged with the inner spline 215b of the peripheral wall, and the inner peripheral projection 221a of the inner plate 221 is engaged with the spline 213a of the coupling shaft portion 213.

  The outer plate 219 and the inner plate 221 are alternately arranged, and the pressing plate 217 is arranged to face the inner plate 221 at the outer end. An inner spline 217 a is formed on the inner periphery of the pressing plate 217 and engages with the spline 213 a of the coupling shaft portion 213.

  The outer surface of the pressing plate 217 in the axial direction is fastened by a nut 223 that is screwed into the screw portion 213b of the coupling shaft portion 213. The frictional transmission force between the outer plate 219 and the inner plate 221 can be adjusted by the fastening force of the nut 223.

  The mechanism of the frictional coupling transmission part 211 is not particularly limited as long as it has the above-mentioned function. A clutch using a magnetic fluid, a coupling using silicone oil and an outer plate and an inner plate, an electromagnet And a multi-plate pilot clutch and an electromagnetic clutch or the like that is engaged with a main clutch that is fastened through a cam that operates with a fastening force of the pilot clutch can be appropriately employed.

  With this structure, when there is a driving input from the engine to the input coupling portion 209 of the torsion bar 202, the input is performed to the outer shaft 201 via the torsion portion 203, the coupling shaft portion 213, and the friction coupling transmission portion 211, The effect of the transmission 1 can be exhibited.

  The transmission 1 significantly reduces the shift shock, but a slight remaining shift shock can be absorbed by the torsional elastic force of the torsion bar 202.

  More specifically, when a shift shock is input to the outer shaft 201 at the time of the shift, it is input to the case 215 via the spline 201a and the inner spline 215a.

  The input to the case 215 is transmitted from the inner spline 215b to the outer plate 219, and is input from the spline 213a to the coupling shaft portion 213 via the frictional transmission force between the outer plate 219 and the inner plate 221.

  The input to the coupling shaft portion 213 is received by the torsion portion 203 with the input coupling portion 209 that receives the input from the engine, and is absorbed by the torsional elastic force of the torsion portion 203.

  Further, when the twist of the torsion part 203 returns and vibrates, the frictional coupling transmission part 211 has a damping function and can attenuate the vibration.

  When there is an abrupt drive input to the main shaft 3, the friction coupling transmission part 211 can exhibit a torque limiter function by sliding between the outer plate 219 and the inner plate 221.

  For these reasons, it is possible to reduce the generation of gear shifting noise and protect the functional components.

  The torsional elastic characteristics can be easily changed by changing the diameter of the torsion part 203 of the torsion bar 202.

  By adjusting the fastening force between the outer plate 219 and the inner plate 221 by the nut 223, the damping characteristic and the torque limiter characteristic of the frictional coupling transmission part 211 can be changed by external adjustment.

  The torsion part 203 of the torsion bar 202 may be replaced with a machined spring (registered trademark “Miki Pulley Co., Ltd.”). Machined springs are coil springs with spiral cuts made by cutting, and the torsional torque can be determined by tightening with a torsional torque above a certain level, allowing reliable torque transmission. .

  FIG. 21 is a schematic sectional view showing a transmission together with a front differential device according to still another reference example. The basic configuration is the same as that of the reference example in FIGS. 1 to 20, and the same components are denoted by the same reference numerals, the corresponding components are denoted by the same reference numerals with A, and duplicate descriptions are omitted. Omitted.

  In the transmission 1A of this embodiment, a frictional coupling transmission portion 211A as a damping portion is provided between the input coupling portion 209 and the outer shaft 201A. That is, a spline is formed on the outer periphery of the end portion where the input coupling portion 209 and the outer shaft 201A abut each other, and the friction coupling transmission portion 211A is engaged with the spline.

That is, the case 215A of the frictional coupling transmission part 211A is engaged with the spline of the outer shaft 201A, and the outer plate is engaged with the case 215A. The inner plate of the frictional coupling transmission portion 211A engages with the spline of the input coupling portion 209, and the nut 223A is screwed or press-fitted to the outer periphery of the input coupling portion 209. The coupling member 210 is spline-fitted, and this coupling member 210 is fastened and fixed to the coupling shaft portion 213A of the torsion bar 202A by a nut 212.

  Therefore, in this reference example, torque can be transmitted from the torsion bar 202A to the outer shaft 201A via the coupling member 210, and the shift shock can be absorbed by the torsional elasticity of the torsion bar 202A. Further, the torsional vibration of the torsion bar 202A with respect to the outer shaft 201A when absorbing the shift shock can be accurately damped by the frictional coupling transmission portion 211A.

  In addition, the same effects as the reference examples of FIGS. 1 to 20 can be obtained.

  FIGS. 22 and 23 relate to still another reference example, FIG. 22 is a schematic cross-sectional view showing the transmission together with the front differential device, and FIG. 23 (A) is a schematic view showing the position of the pressure plate in the direction of arrows XXIIIA-XXIIIA in FIG. (B) is a cross-sectional view of the center ring, (C) is a front view of the center ring, (D) is a front view of the pressure ring, and (E) is a cross-sectional view showing the engagement of the ring. It is sectional drawing of a pressure ring. The basic configuration is the same as that of the reference example in FIGS. 1 to 20, and the same components are described with the same reference numerals, the corresponding components are described with the same reference numerals B, and duplicated descriptions are omitted. Omitted.

  As shown in FIGS. 22 and 23, the transmission 1B of the present reference example is provided with a disc spring 225 as an elastic member and a damping cam mechanism 227 as a damping portion on a front differential device 137B as a differential device. It is a thing.

  Specifically, the front differential device 137B includes a pinion gear 231 and a pair of side gears 233 in a differential case 229, a center ring 235, a pressure ring 237, the disc spring 225, a damping A cam mechanism 227 is provided.

  The center ring 235 supports the pinion gear 231 via the pinion shaft 238 and is supported so as to be relatively rotatable about the axis of the differential case 229.

  The pressure ring 237 is supported so as not to rotate relative to the differential case 229 and to move in the axial direction. The non-rotatable support around the axis is provided by a pin 239 disposed between the groove on the inner surface of the differential case 229 and the recess on the outer peripheral surface of the pressure ring 237, and the pressure ring 237 extends along the pin 239. The differential case 229 is configured to be movable in the axial direction.

  The disc spring 225 is disposed between the pressure rings 237 and the differential case 229.

  The damping cam mechanism 227 is configured by fitting a chevron-shaped cam convex portion 227a formed on the center ring 235 into a cam concave portion 227b having a corresponding shape formed on the pressure ring 237.

  Therefore, when a shift shock is applied to the front differential device 137, it is input from the differential case 229 to the pressure ring 237 via the pin 239.

  At this time, since the center ring 235 receives resistance from the rear wheel side via the pinion shaft 238, the pinion gear 231, and the side gear 233 that meshes with the pinion gear 231, the pressure ring 237 is caused by the shift shock. Rotates relative to the center ring 235.

  Due to this relative rotation, the damping cam mechanism 227 acts, the pressure ring 237 moves outward in the axial direction, and this movement is absorbed by the elastic force of each disc spring 225.

  The vibration of each disc spring 225 at this time is attenuated by the frictional force between the cam convex portion 227a and the cam concave portion 227b.

  Thus, even in this reference example, it is possible to absorb and attenuate the shift shock.

  In addition, the same effects as the reference examples of FIGS. 1 to 20 can be obtained.

  FIG. 24 is a schematic cross-sectional view showing application to an ER-based transmission according to still another reference example. The basic configuration as the invention is the same as that of the reference example shown in FIGS.

  The transmission 1C of this reference example is configured to be applied to a front engine / rear drive (FR) vehicle as shown in FIG.

  As in the reference examples of FIGS. 1 to 20, a guide portion G is provided at each gear position of the transmission 1C, and seamless gear shifting is performed via the gear shifting operation portion 93, the moving force transmission mechanism M, the cam groove, and the cam protrusion. Can be operated.

  On the other hand, in the transmission 1C, the counter shaft 241 includes a hollow outer shaft 201C and a torsion bar 202C fitted to the outer shaft 201C.

  The torsion part 203C of the torsion bar 202C is formed integrally with the input gear 243, and the connection of the torsion part 203C to the outer shaft 201C is performed in the same manner as in the second embodiment. That is, the coupling member 210C is spline-fitted to the outer shaft 201C outside the bearing 245, and the coupling member 210C is fastened and fixed to the coupling shaft portion 213C of the torsion bar 202C by the nut 212C.

  Between the outer shaft 201C and the input gear 243, there is provided a friction coupling transmission portion 211C comprising an outer plate and an inner plate. The outer plate is spline-engaged with the outer shaft 201C, and the inner plate is The torsion part 203C is spline-engaged. The outer plate and the inner plate are fastened between the outer shaft 201C and the input gear 243 by a nut 212C.

  Therefore, in this reference example, torque can be transmitted from the torsion bar 202C to the outer shaft 201C via the coupling member 210C, and the shift shock can be absorbed by the torsional elasticity of the torsion bar 202C. Further, the torsional vibration of the torsion bar 202C relative to the outer shaft 201C when absorbing the shift shock can be accurately damped by the frictional coupling transmission portion 211A.

  In addition, the same effects as the reference examples of FIGS. 1 to 20 can be obtained.

  FIG. 25 is a cross-sectional view illustrating the drive meshing position, which is related to the main part of the meshing clutch of the first embodiment. This embodiment can be applied to any of the reference examples shown in FIGS. 1 to 20 and the other reference examples shown in FIGS.

  In the transmission of this embodiment, the first to third meshing clutches 47, 49, 51 of the reference example are changed.

  That is, according to the first embodiment of the present invention, the first gear 19, the second gear 21, and the third gear 21 are three-speed transmission gears that are rotatably supported by the main shaft 3 or the counter shaft 5 that is a driving force transmission shaft. A plurality of transmission gears are provided for selectively coupling the speed gear 23 to the main shaft 3 or the counter shaft 5 to output a speed change. Clutch rings 59, 61, 63 that are arranged on both sides apart from the 2nd speed and can be selectively engaged with the transmission gears on both sides by a meshing clutch, and a gear shifting operation that selectively operates this clutch ring And a portion 93.

  As described with reference to FIGS. 9 and 10, the clutch rings 59, 61 and 63 of the first embodiment are the transmission gear 1st gear 19, 3rd gear 23, 2nd gear 21, 5th gear 27, 4 The first gear to the third gear clutch 47, 49, 51 are engaged at the first meshing position in the axial direction with respect to the speed gear 25 and the sixth gear 29, and the meshing is performed more than the first meshing position. The first to third meshing clutches 47, 49, 51 can be moved to a meshed state at the second meshing position to be shallowed.

  The third meshing clutch 51 will be described as a representative as in FIG. 12. As shown in FIG. 25, the guide surface 51 ba is provided. The guide surface 51ba is set to be inclined in the rotational direction, and when the shift operation unit 93 is operated, the lower and upper clutch rings 63 and 61 are simultaneously meshed with the lower shift clutch ring 63. An axial force in the mesh release direction is generated at the meshing position 2.

  That is, the third meshing clutch 51 has a clutch tooth 29a on the 6th speed gear 29 side that is a transmission gear and a clutch tooth 51b on the clutch ring 63 side, and the guide surface 51ba is formed of the clutch teeth 51b and 29a. One side 51b is provided to generate an axial force in the disengagement direction on the clutch ring 63 by a relative guide of the tip 29aa of the other 29a of the clutch teeth 51b and 29a during the coasting torque.

  The guide surface 51ba is inclined in the drive direction toward the tooth tip side. A coast meshing surface 51bb is formed at the root of the clutch tooth 51b in the rotation direction, and is smoothly continuous with the guide surface 51ba.

  Corresponding to the coast meshing surface 51bb, a coast meshing surface 29ab is formed which is continuous with the tip 29aa of the other 29a of the clutch teeth 51b, 29a. A flank 29ac is formed continuously to the coasting surface 29ab.

  The clutch ring 63 includes a drive slope F as a mechanism for bringing the third meshing clutch 51 into meshing state at the second meshing position.

  The driving slope F is formed at the tooth base on the other side in the rotational direction of either one of the clutch teeth 51b and 29a, and is relative to the tip 29ad of the other 29a of the clutch teeth 51b and 29a when the driving force is transmitted. The guide is used to move the clutch ring 63 from the first engagement position to the second engagement position.

  Therefore, the mechanism for causing the clutch ring 63 to engage with the third engagement clutch 51 at the second engagement position is formed at the tooth base on one side in the rotational direction of either one of the clutch teeth 51b and 29a. The drive slope F moves the clutch ring 63 from the first meshing position to the second meshing position by a relative guide between the clutch teeth 51b and 29a and the tip 29aa of the other 29a when the driving force is transmitted. is there. The same applies to the first and second meshing clutches 47 and 49 for the clutch rings 59 and 61.

  On the other side of the clutch tooth 51b in the rotational direction, a drive meshing surface 51bc continuous with the drive slope F is formed. The drive engagement surface 51bc is formed to be inclined in the drive direction toward the tooth tip side.

  Corresponding to the drive meshing surface 51bc, a drive meshing surface 29ae continuing to the tip 29ad of the other 29a of the clutch teeth 51b, 29a is inclined.

  The guide surface 51ba and the drive slope F can also be formed on the 6th speed gear 29 side which is a transmission gear.

  The structure of the clutch teeth 51b and 29a is the same for the first and second meshing clutches 47 and 49.

[drive]
When the third meshing clutch 51 is meshed with, for example, the sixth gear 29 and driving torque is applied, the clutch ring 63 is moved by the driving slope F as shown in FIG. At this time, the recess 129b of the shift fork 87 shown in FIG. 10 pushes the ball 133a, and the spring 133b is pressurized and stores energy. This movement is allowed because the shift groove 125 is appropriately provided with axial play with respect to the guide of the shift arm 117.

  As a result of this movement, the clutch ring 63 becomes the disengagement standby position of FIG. 25 which has moved to the disengagement side from the coast meshing position (see FIGS. 9 and 12A).

  This disengagement standby position is a state where the third engagement clutch 51 is engaged with the drive engagement surfaces 51bc and 29ae at a second engagement position where engagement is shallower than a first engagement position described later.

  Next, when the driving torque changes in the coast direction, the live engagement surfaces 51bc and 29ae of the clutch teeth 29a are separated. At this time, due to the energy of the spring 133b, the concave portion 129b and the ball 133a act to deeply engage at the first engagement position (see FIGS. 9 and 12A). In this state, since the coast meshing surface 29ab shown in FIG. 25 contacts the coast meshing surface 51bb, no thrust force is generated in the clutch ring 63.

[Shift up 4th → 5th]
Again, description will be made with reference to FIG. 25 based on the movement at the time of upshifting in FIGS. FIG. 25 is an explanation on the sixth gear 29 side of the third meshing clutch 51, but the first and second meshing clutches 47 and 49 have the same structure, and therefore corresponding guides. The description of the surface and the like will be described with reference to FIG.

  Since drive torque is applied to the fourth-speed clutch teeth 25a in FIG. 13, the clutch ring 63 is in the disengagement standby position as shown in FIG.

  That is, as in FIG. 25, the guide surface 51ba of the clutch ring 63 in the fourth speed position faces the drive meshing surface 29ae of the clutch tooth 29a in the rotational direction.

  At this time, when a shift-up operation to the fifth speed is performed by the rotation of the shift drum 119, the shift groove 123 works, and the clutch ring 61 is moved via the shift arm 115, the shift rod 107, and the shift fork 85. Operated. By this operation, the clutch ring 61 is engaged with the fifth gear 27 and the fourth gear 25 and the fifth gear 27 are simultaneously engaged.

  At this time, as described above, coasting torque is generated on the 4th speed side and drive torque is generated on the 5th speed side due to the internal circulation torque caused by the mechanical meshing regardless of the engine output torque. This torque generates a thrust force in the disengagement (neutral) direction with respect to the clutch ring 63 at the fourth speed position by the action of the inclined surface of the guide surface 51ba, and the clutch ring 63 moves from the fourth speed position to the release position. To do.

  The clutch ring 61 in the fifth speed position generates a thrust force in the direction in which the drive engagement surface 51bc is guided by the inclination of the drive engagement surface 29ae to deepen the engagement, and the clutch ring 61 moves in the engagement direction. 5th position.

  As a result of such release and meshing, the upshifting to the fifth speed is completed as shown in FIG.

  At the time of shifting, the shift shock can be absorbed or reduced by the elastic portion and the damping portion of FIGS.

  Therefore, the same effect as described above can be achieved by the structure of the first embodiment.

  Shifting up at other speeds can be performed in the same manner. FIG. 26 is a cross-sectional view showing the drive meshing position in relation to the main part of the meshing clutch according to the modification.

  In FIG. 26, the drive engagement surface 51bc and the drive engagement surface 29ae are not inclined and are set substantially parallel to the axial direction.

  In this example, a thrust force is not generated between the drive engagement surface 51bc and the drive engagement surface 29ae at the time of simultaneous engagement, and the clutch ring on the upper speed side of the shift moves only by the shift force from the speed change operation unit 93. become.

  Accordingly, the drive meshing surface 51bc constitutes a guide surface, and the first to third meshing clutches 47, 49, 51 are shifted to the lower gear and the gearshift by the shift-up operation or the shift-down operation of the shift operation unit 93. When the upper clutch ring (59, 61, 63) is engaged at the same time, the clutch ring (59, 61, 63) between the lower gear and the upper gear is engaged by the coasting torque at the second engagement position. The guide surface (51ba, 51bc) is provided that generates axial forces in different directions, ie, a different direction and a disengagement direction.

[Clutch tooth wear prevention]
FIG. 27 relates to a comparative example and explains the wear of the tooth tip of the meshing clutch. FIG. 27A shows one of the meshing of the meshing tooth and the meshing tooth viewed from the tangential direction of the clutch ring. XXVIIB-XXVIIB arrow sectional view of (A), FIG. 28 relates to the present embodiment, explaining wear of the tooth tip of the meshing clutch, (A) is the clutch tooth 1B is a schematic cross-sectional view of one of the meshes as viewed from the tangential direction of the clutch ring, (B) is a schematic cross-sectional view of the clutch teeth as viewed from the tangential direction of the clutch ring, and FIG. It is XXIIIXC-XXIIIXC arrow sectional drawing of A).

  As shown in FIG. 27A, for example, when the engagement between the clutch teeth 51b of the clutch ring 63 and the clutch teeth 29a of the sixth speed gear 29 is seen through the side from the tangential direction of the clutch ring 63, the clutch ring The clutch teeth 51b and the clutch teeth 29a are engaged with each other in the radial direction of 63.

  In such engagement, the tip 29ad of the clutch teeth 29a repeatedly collides with the clutch teeth 51b by repeated engagement and disengagement, and wear is caused by long-term use.

  When the tip 29ad of the clutch tooth 29a is worn, the position of the clutch tooth 29a with respect to the drive slope F is slightly shifted toward the engagement position, and the second engagement position, which is the release standby position, is shifted. There is a risk that the withdrawal may not be performed smoothly.

  On the other hand, in this embodiment, as shown in FIGS. 28A and 28B, the collision avoidance slope 51be is provided on the clutch tooth 51b.

  In the clutch teeth of FIGS. 28 (A) and (B), since the tip 29ad of the clutch tooth 29a does not collide with the clutch tooth 51b at the beginning of meshing by the collision avoiding slope 51be, there is at least wear on this part. No or significantly reduced.

  For this reason, when the clutch ring 63 moves to the second meshing position by the relative guide between the tip 29ad of the clutch tooth 29a and the drive slope F of the clutch tooth 51b, the portion that does not collide with the drive slope F Since 29ada receives a relative guide, the clutch ring 63 can be accurately moved to the second meshing position.

  The same applies to the other clutch rings 59 and 61.

  The clutch rings 59, 61, and 63 only need to have a thrust force in the mesh release direction at the second meshing position at the time of simultaneous meshing, and the transmission gears need to be arranged on both sides with the second speed or higher. There is no.

1, 1A, 1B, 1C Transmission 3 Main shaft (drive force transmission shaft)
5 Counter shaft (driving force transmission shaft)
19 1st gear (transmission gear)
21 2nd gear (transmission gear)
23 3rd gear (transmission gear)
25 4-speed gear (transmission gear)
27 5-speed gear (transmission gear)
29 6-speed gear (transmission gear)
51ba Guide surface 59, 61, 63 Clutch ring 65, 67, 69 Cam groove 71, 73, 75 Cam protrusion (protrusion)
77, 79, 85, 87 Shift fork 103, 105, 107, 109 Shift rod 111, 113, 115, 117 Shift arm 119 Shift drum 120, 121, 123, 125 Shift groove 131, 133 Check section 47 No. 1 meshing clutch 49 2nd meshing clutch 51 3rd meshing clutch 59, 61, 63 Clutch ring 93 Transmission operation part 201, 201A, 201C Outer shaft 202, 202A, 202C Torsion bar (elastic part )
209 Input coupling part 211, 211A, 211C Friction coupling transmission part (attenuation part)
225 Belleville spring (elastic part, elastic member)
227 Damping cam mechanism (damping part)
F Driving slope G Guide part M Moving force transmission mechanism T Transmission surface

Claims (7)

A plurality of speed change gears supported by a driving force transmission shaft so as to be relatively rotatable, and a plurality of speed change gears that are selectively coupled to the driving force transmission shaft to output a speed change, and mesh with the speed change gear. A clutch ring that can be selectively engaged with each other, a shift operation portion that selectively operates the clutch ring, and a guide portion that is provided between the clutch ring and the driving force transmission shaft. ,
The guide portion includes a cam groove and a cam protrusion that fits into the cam groove,
The cam groove includes a surface that allows the cam protrusion to engage in the rotational direction of the driving force transmission shaft and is inclined with respect to the axial direction.
When the clutch ring of the lower gear and the upper gear is engaged at the same time by the operation of the transmission operation portion, the inclined surface of the cam groove and the cam protrusion are engaged in the simultaneous engagement by the internal circulation torque, and the inclination of the surface to release the engagement by causing axial force releasing direction meshing the gear lower or shift the upper clutch ring while permitting relative rotation of the simultaneous meshing Isle clutch ring,
The clutch ring is engaged with the gear clutch at a first meshing position in the axial direction with respect to the transmission gear and at a second meshing position where the meshing is shallower than the first meshing position. The meshing clutch is movable to a meshing state;
The meshing clutch has a coasting torque at the second meshing position with the clutch ring of the lower gear stage or the upper stage of the gearshift when the clutch ring of the lower gear stage and the upper gear stage are meshed simultaneously by the operation of the speed change operation unit. A guide surface that generates an axial force in the meshing release direction by
A mechanism for setting the clutch ring in the lower gear stage or the upper gear stage to the second meshing position when the clutch ring is engaged at the same time;
Transmission characterized by that. A plurality of speed change gears supported by a driving force transmission shaft so as to be relatively rotatable, and a plurality of speed change gears that are selectively coupled to the driving force transmission shaft to output a speed change, and mesh with the speed change gear. A clutch ring that can be selectively engaged with each other, a shift operation portion that selectively operates the clutch ring, and a guide portion that is provided between the clutch ring and the driving force transmission shaft. ,
The guide portion includes a cam groove and a cam protrusion that fits into the cam groove,
The cam groove includes a surface that allows the cam protrusion to engage in the rotational direction of the driving force transmission shaft and is inclined with respect to the axial direction.
When the clutch ring of the lower gear and the upper gear is engaged at the same time by the operation of the transmission operation portion, the inclined surface of the cam groove and the cam protrusion are engaged in the simultaneous engagement by the internal circulation torque, and the inclination of the surface to release the engagement by causing axial force releasing direction meshing the gear lower or shift the upper clutch ring while permitting relative rotation of the simultaneous meshing Isle clutch ring,
The clutch ring is engaged with the gear clutch at a first meshing position in the axial direction with respect to the transmission gear and at a second meshing position where the meshing is shallower than the first meshing position. The meshing clutch is movable to a meshing state;
The meshing clutch is operated at the second meshing position between the clutch and ring of the lower gear and the upper gear when the lower gear and the upper gear are simultaneously engaged by the operation of the speed change operation unit. It has a guide surface that generates axial forces in different directions of the meshing direction and the meshing release direction by the ting torque,
A mechanism for setting the clutch ring in the lower gear stage or the upper gear stage to the second meshing position when the clutch ring is engaged at the same time;
Transmission characterized by that. The transmission according to claim 1 or 2,
The clutch ring is arranged on both sides with the speed change gear separating from the second speed or more,
Transmission characterized by that. The transmission according to any one of claims 1 to 3,
The meshing clutch comprises a clutch tooth on the transmission gear side and a clutch tooth on the clutch ring side,
The guide surface is provided on one of the clutch teeth,
Transmission characterized by that. The transmission according to claim 4, wherein
The mechanism for setting the clutch ring to the second meshing position is formed at the tooth base on one side in the rotational direction of any one of the clutch teeth, and between the other tip of the clutch teeth when driving force is transmitted. A drive ramp for moving the clutch ring from the first engagement position to the second engagement position by a relative guide;
Transmission characterized by that. The transmission according to any one of claims 1 to 5,
The shift operation unit is guided by shift gears of the shift drum supported by the shift forks engaged with the clutch rings, the shift rods supporting the shift forks, and the shift rods. Each shift arm and
The mechanism for bringing the clutch ring into the second meshing position includes the shift fork, the shift rod, the shift grooves of the shift drum, and a shift arm for each of the lower and upper shift clutch rings. Comprising the shift drum,
Transmission characterized by that. The transmission according to any one of claims 1 to 6,
Only one of the lower gear or upper gear clutch ring accumulates elastic energy to the clutch ring when transmitting the meshing force, and the coasting torque is A mechanism for returning the clutch ring from the second engagement position to the first engagement position by the elastic energy;
Transmission characterized by that.

Images