JP6669835B2 - transmission - Google Patents

Description

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

  In general, in a vehicle transmission using a single clutch, the driving force is interrupted at the time of shifting, and shift shock, acceleration delay, and the like are inevitable. Also, in the case of a construction machine, an agricultural machine, or the like having a large running resistance and a small speed energy, when the driving force is interrupted at the time of shifting, there is a case that the shifting is difficult and the shifting is difficult.

  On the other hand, a twin-clutch transmission is known to be able to suppress a shift shock and an acceleration delay without interrupting the driving force.

  However, the twin clutch transmission has a problem that the structure is complicated and the weight is large.

  On the other hand, seamless shift transmissions have attracted attention as being capable of suppressing an increase in weight.

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

  This seamless shift transmission includes three first burettes engaged with an input shaft between a first gear and a second gear, and three second burets, and moves in accordance with a shift operation. . Mesh teeth are formed on the first gear and the second gear, and complex faces different in front and rear directions of rotation are formed at both ends of the first buret and the second buret.

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

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

  By the first burette and the second burette having such a complicated face and the selecting operation via the spring, the driving force is not interrupted, the shift shock and the delay of acceleration can be suppressed, and the weight can be reduced. .

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

On the other hand, a transmission was proposed in which the driving force was not interrupted, the shift shock and the delay of acceleration were suppressed, the weight could be reduced, and the structure could be simplified. (Patent Document 1)
Although this transmission achieved its basic intended purpose, Applicants have further refined it in terms of shifting shock.

JP 2012-127471 A

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

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

According to the present invention, since the driving force is not interrupted, shift shock and delay of acceleration can be suppressed, weight can be reduced, and the structure can be simplified. A plurality of supported transmission gears; and a plurality of clutch rings provided for selectively coupling the transmission gears to the driving force transmission shaft and outputting a transmission, and capable of selectively meshing with the transmission gears; and a shift operating unit for operating the clutch ring selectively, the shift lower when shifting lower and shifting the upper clutch ring has had co engaged by the shift-up operation or shift-down operation of the gearshift operating part wherein said shift lower drive torque is generated to shift the upper clutch ring or shifting the upper clutch Li with coasting torque on clutch ring occurs A transmission which performs shift by causing axial forces of meshing releasing direction grayed, the clutch ring and the speed change gear is provided with a meshing clutch teeth in the rotational direction, the clutch teeth, by the simultaneous engagement A guide surface for generating a thrust force in the direction of disengagement by the action of the slope is provided.

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

FIG. 2 is a schematic sectional view showing a transmission together with a front differential device. (Reference Example 1) FIG. 2 is an enlarged sectional view of a main part of the transmission. (Reference Example 1) It is a development view showing a cam groove and a cam projection. (Reference Example 1) It is a development view showing a cam groove and a cam projection. (Reference Example 1) It is a perspective view which shows the relationship between a clutch cam ring and a clutch ring. (Reference Example 1) FIG. 4 is a perspective view showing a relationship between a clutch cam ring and a clutch ring (Reference Example 1). It is a perspective view showing a clutch cam ring. (Reference Example 1) It is a perspective view which shows a clutch ring. (Reference Example 1) It is a schematic diagram showing a relation with a shift fork, a check part, and a dog clutch. (Reference Example 1) It is a schematic diagram showing a relation with a shift fork, a check part, and a dog clutch. (Reference Example 1) FIG. 3 is a development view of a main part of the clutch ring. (Reference Example 1) FIG. 3A is an essential part developed view showing the engagement of the dog clutch, in which FIG. 3A is a coast mesh position, and FIG. 2B is a standby mesh position. (Reference Example 1) FIG. 5 is a schematic diagram showing the engagement of fourth-speed gears of the transmission during upshifting. (Reference Example 1) FIG. 8 is a schematic diagram showing a position of a transmission in a standby state for disengagement of a fourth-speed clutch ring during upshifting. (Reference Example 1) It is a schematic diagram at the time of shifting to fifth speed. (Reference Example 1) FIG. 9 is a schematic diagram showing that the fourth speed and the fifth speed are neutral when downshifting. (Reference Example 1) It is an operation explanation of a drum groove at the time of shift up and shift down. (Reference Example 1) FIG. 2 is a schematic sectional view showing a transmission together with a front differential device. (Reference Example 1) It is an expanded sectional view around a connection part. (Reference Example 1) (A) is an enlarged front view of the outer plate of the coupling transmission unit, and (B) is an enlarged front view of the inner plate of the coupling transmission unit. (Reference Example 1) FIG. 2 is a schematic sectional view showing a transmission together with a front differential device. (Reference Example 2) FIG. 2 is a schematic sectional view showing a transmission together with a front differential device. (Reference Example 3) (A) is a schematic cross-sectional view showing engagement of the pressure shear ring as viewed from arrows XXIIIA-XXIIIA in FIG. 22, (B) is a cross-sectional view of the center ring, and (C) is a front view of the center ring. (D) is a front view of the pressure ring, and (E) is a sectional view of the pressure ring. (Reference Example 3) 1 is a schematic cross-sectional view showing an application to an ER-based transmission. (Reference Example 4) FIG. 4 is a cross-sectional view showing a drive meshing position, relating to a main portion of the meshing clutch. (Example 1) FIG. 11 is a cross-sectional view showing a drive meshing position, relating to a main portion of a meshing clutch according to a modification. (Example 2) (A) is a schematic cross-sectional view of one of the meshing of the meshing tooth and the meshed tooth as viewed from the tangential direction of the clutch ring; (B) is XXVIIB-XXVIIB arrow sectional drawing of (A). (A) is a schematic cross-sectional view of one of the meshing of the meshing tooth and the meshed tooth as viewed from the tangential direction of the clutch ring, and (B) is a diagram illustrating the meshing of the meshing tooth. FIG. 7C is a schematic cross-sectional view of the disengaged state of the intermeshing and intermeshing teeth as viewed from the tangential direction of the clutch ring, and FIG. 10C is a cross-sectional view taken along the line XXIIXC-XXIIXC of FIG.

  The purpose of the clutch ring and the transmission gear is to prevent the drive force from being interrupted, to suppress shift shocks and delays in acceleration, to reduce the weight, and to simplify the structure. The clutch teeth are meshed with each other, and the clutch teeth are provided with a guide surface that generates a thrust force in a disengagement direction by the action of a slope by coasting torque.

  The first embodiment of the present invention is characterized in that the clutch teeth are provided with a guide surface that generates a thrust force in the direction of disengagement by the action of the slope by the coasting torque, but employs the elastic portion and the damping portion. Prior to the structure described above, the structure and operation of the transmission, which is the premise of the first embodiment of the present invention, will be described overall with reference to FIGS. The section will be described.

  FIG. 1 is a schematic sectional view showing a transmission according to a first embodiment 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 a transmission case 17 by bearings 9, 11, 13, 15 and the like. The idler shaft 7 is fixed to the transmission 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 provided relative to the main shaft 3 and the counter shaft 5 as a plurality of speed change gears. It is rotatably supported.

  The first speed gear 19 and the third speed gear 23 on the counter shaft 5 mesh with the output gears 31 and 33 of the main shaft 3, and the second speed gear 21, the fourth speed gear 25 and the fifth speed gear on the main shaft 3. The 27th and 6th 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 arranged so as to mesh with an output gear 44 on the main shaft 3 and an input gear 45 on the counter shaft 5 by axial movement.

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

  The first to third dog clutches 47, 49, 51 change the speed of the plurality of speed gears to the upper gear by changing the plurality of first to third dog clutches 47, 49, 51. It has become.

  That is, 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, which are a plurality of speed change gears, are first to third meshing clutches 47. , 49, and 51 are changed so as to perform gear shifting.

  For example, shifting 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 dog clutches 47, 49, 51 have basically 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 opposing surfaces of the first gear 19 to the sixth gear 29, respectively. .

  Therefore, the clutch rings 59, 61, 63 are meshed 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, Coupling for shifting output is performed by selective engagement of 25a, 27a, and 29a.

  The V-shaped cam grooves 65, 67, and 69 are formed in the clutch cam rings 53, 55, and 57 of the first to third dog clutches 47, 49, and 51, respectively. The clutch cam ring 53 of the first dog clutch 47 is connected to the counter shaft 5 by spline fitting or the like, and is rotatable integrally. The clutch cam rings 55, 57 of the second and third dog clutches 49, 51 are connected to the main shaft 3 by spline fitting or the like, and are integrally rotatable.

  The clutch rings 59, 61, 63 of the first to third meshing clutches 47, 49, 51 are fitted around the outer circumferences of the clutch cam rings 53, 55, 57 and are movable in the axial direction. ing. The clutch rings 61 and 63 selectively connect the second gear 21, the fourth gear 25, the fifth gear 27, and the sixth gear 29, which are transmission gears, to the main shaft 3 that is the driving force transmission shaft. A clutch ring 59 is provided to selectively couple the first gear 19 and the third gear 23, which are transmission gears, to the counter shaft 5 which is the driving force transmission shaft. There are several to provide. On the inner periphery of the clutch rings 59, 61, 63, cam projections 71, 73, 75 each having a circular cross section are formed as projections so as to fit into and be guided by the cam grooves 65, 67, 69. I have.

  The clutch ring 59 and the reverse idler 43 are formed with circumferential concave streaks 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, a first gear 19, a second gear 21, a third gear 23, a fourth gear 25, a fifth gear 27, and a sixth gear 29 are selected, and each side is selected. The second and third gears are arranged so that the transmission gears on both sides can be selectively engaged with each other. That is, the first gear 19, the third gear 23 are arranged on both sides of the clutch ring 59, the second gear 21, the fifth gear 27 are arranged on both sides of the clutch ring 61, and the clutch ring 63 A fourth-speed gear 25 and a sixth-speed gear 29 are arranged on both sides.

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

  The shift operation section 93 is provided in the transmission 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.

  The 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 of the meshing clutches 47, 49, 51, the reverse idler. 43 in conjunction with each other.

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

  The shift arms 111, 113, 115, 117 are connected to the respective shift rods 103, 105, 107, 109.

  The shift drum 119 has shift grooves 120, 121, 123, and 125, and the tip 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 transmission case 17. Although an uneven portion and a check portion having the same structure are provided between the shift fork 99 and the transmission case 17, they are not shown.

  The concave / convex portions 127 and 129 are formed on the shift forks 95 and 97, and include angled positioning concave portions 127a, 127b, 127c, 129a, 129b, and 129c. The positioning recesses 127a, 129a correspond to the neutral position, and the positioning recesses 127b, 127c, 129b, 129c correspond to the coast meshing position.

  The check portions 131 and 133 are supported by the transmission case 17 side, and urge the check balls 131a and 133a by the check springs 131b and 133b to engage the concave and convex portions 127 and 129 with elastic force. By this engagement, the first to third meshing clutches 47, 49, 51 can be positioned between the neutral position and the coast meshing position.

  The output of the transmission 1 is provided 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 a manual operation signal of a shift lever or an accelerator opening and a vehicle speed signal by operating an accelerator pedal, the shift is performed. The shift rods 103, 105, 107, and 109 are selectively driven in the axial direction through any 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, and 109, the first to third dog clutches 47, 49, and 51 or the reverse idler are provided via any of the shift forks 77, 79, 85, and 87. 43 is selected. By this selection operation, the 1st gear 19th to 6th gear 29 and the reverse idler 43 are selectively operated, and it is possible to perform shift up, shift down, and reverse change.

[Guide]
The output torque of the engine when the lower speed gear and the upper speed gear are engaged simultaneously with the shift operation unit 93 and the first to third mesh clutches 47, 49, 51 by the operation of the shift operation unit 93. Irrespective of the mechanism, the internal circulating torque inevitably generated by the mechanism causes the torque in the drive direction to act on the clutch ring in the upper stage of the shift to generate an axial force in the direction of meshing deeper, and the clutch ring in the lower stage of the shift has the course Guide portions G are provided at each stage for individually generating an axial force in the direction of releasing the engagement by moving the clutch in the neutral direction by the torque.

  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 as described above, and the clutch rings 59, 61, The structure is provided between the main shaft 3 and the driving force transmission shaft 63. The cam grooves 65, 67, 69 and the cam projections 71, 73, 75 transfer the driving torque and the coasting torque at the coast engagement positions of the first to third engagement clutches 47, 49, 51 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, and the course is provided only at the stand-by position where the gear is shifted to the meshing side from the coast meshing position. The meshing can be guided in the neutral direction by the torque in the pointing direction.

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

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

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

  That is, in the present embodiment, the mechanism that brings the clutch rings 59, 61, 63 into a state in which the first to third meshing clutches 47, 49, 51 mesh with each other at the second meshing position is such that the drive slope F is Constitute.

  As will be described later, the drive slope F is formed at one of the roots in one rotation direction of the clutch teeth 47a, 47b, 49a, 49b, 51a, 51b and the clutch teeth 19a, 21a, 23a, 25a, 27a, 29a. At the time of transmitting the driving force, the other end of the clutch teeth 47a, 47b, 49a, 49b, 51a, 51b and the clutch teeth 19a, 21a, 23a, 25a, 27a, 29a is guided to form the clutch rings 59, 61, 63. It is to move from the first meshing position to the second meshing position.

  3 and 4 are developed views showing a cam groove and a cam projection, FIGS. 5 and 6 are perspective views showing the relationship between a clutch cam ring and a clutch ring, and FIG. 7 is a 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 surfaces of the clutch cam rings 53, 55, 57 at equal intervals in the circumferential direction. The cam grooves 65, 67, and 69 have V-shaped portions 65a, 67a, and 69a formed in the center in the axial direction including a portion corresponding to neutral, and flat portions 65b, 67b, and 69b formed on both sides thereof. Things.

  Therefore, when the dog clutches 47, 49, and 51 are located at the non-standby position, the cam projections 71, 73, and 75 are located on the flat portions 65b, 67b, and 69b. The thrust in the neutral direction does not occur and the meshing is maintained.

  The cam projections 71, 73, and 75 are radially projected on the inner circumference of the clutch rings 59, 61, and 63 at regular intervals in the circumferential direction, are fitted into the cam grooves 65, 67, and 69, and are guided. It has become.

  Therefore, at the coast meshing positions of the first to third meshing clutches 47, 49, 51, the cam projections 71, 73, 75 are located on the flat portions 65b, 67b, 69b, and the driving torque and the coasting torque are set. 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.

  At the positions where the first to third dog clutches 47, 49, and 51 are in a stand-by state, the cam projections 71, 73, and 75 are located at the V-shaped portions 65a, 67a, and 69a. The meshing can be guided in the neutral direction by the directional torque.

  9 and 10 are schematic diagrams showing the relationship between the shift fork, the check section, and the dog clutch, FIG. 11 is a development view of a main part of the clutch ring, and FIG. FIG. 3A is a main part developed view showing a coast meshing position, and FIG. 9 to 12 illustrate the third dog clutch. The same applies to the first and second dog clutches, and redundant description is omitted.

  As shown in FIGS. 1 and 9 to 12, the third dog 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 gear 25 and the sixth gear 29. In the circumferential arrangement, they have 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 slopes F are formed on the meshing surfaces that receive the drive torque.

  Accordingly, when the third dog clutch 51 is meshed and connected to, for example, the sixth speed gear 29 and a 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 provided with an appropriate axial play for the guide of the shift arm 117. Due to this movement, the clutch ring 63 is moved to the meshing and disengaging side from the coast meshing position in FIGS. 9 and 12 (a) to the disengagement standby position in FIGS. 10 and 12 (b). Next, when the driving torque changes in the coast direction, the teeth are pressed to the opposite side and separate from the slope F shown in FIGS. Therefore, the energy of the spring 133b causes the concave portion 129b and the ball 133a to be brought into a deep meshing state shown in FIGS. 9 and 12A. In this state, since the cam protrusion 75 shown in FIG. 2 is located on the flat portion 69 b on the axial end side of the cam groove 69, no thrust is generated on the clutch ring 63.

  As described above, in the present reference example, the recess 129b, the ball 133a, and the spring 133b of the shift fork 87 are engaged with the clutch during transmission of the driving force in which only the clutch ring (59, 61, 63) at the lower stage of the gear shift is engaged. A mechanism for storing energy for returning the rings (59, 61, 63) from the second meshing position to the first meshing position is configured, and this mechanism is provided on the speed change operation unit 93 side. .

  Regarding the clutch ring 61 as well, the recess 127b of the shift fork 85, the ball 131a, and the spring 131b constitute a mechanism for storing the same energy.

  That is, the clutch ring (59, 61, 63) is connected to the shift operation unit 93 when the driving force is transmitted when only one of the clutch ring (59, 61, 63) of the lower gear or the upper gear is engaged. The structure is provided with a mechanism for accumulating energy for returning from the second meshing position to the first meshing position.

  On the other hand, when the shift to the upper stage of the shift is started, the shift drum 119 shown in FIG. 1 is rotating, so that the play of the shift arm 117 with respect to the guide is eliminated by the shape of the shift groove 125 at the lower stage of the shift. 109, the movement of the clutch ring 63 in the axial direction is restricted via the shift fork 87, so that the clutch ring 63 is maintained at the disengagement standby position even when the coast torque acts. At this time, since the cam protrusion 75 is moving from the flat portion 69b of the cam groove 69 to the slope, when a coasting torque is applied to the lower gear due to meshing of the upper gear, the neutral of the cam groove 69 is caused by the slope of the cam groove 69. A thrust component moving in the direction can be obtained. The 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) are linked. The clutch ring (59, 61, 63) is moved from the second meshing position to the first meshing position at the time of the coasting torque in which the clutch gears (59, 61, 63) of the lower gear and the upper gear are simultaneously meshed. And a mechanism for maintaining the second meshing position against the energy for returning to the second engagement position.

[Shift up 4th → 5th]
FIG. 13 is a schematic diagram showing the fourth-speed gear meshing of the transmission at the time of upshifting, FIG. 14 is a schematic diagram showing the position of the fourth-speed clutch ring of the transmission at the time of upshift waiting for disengagement, and FIG. FIG. 16 is a schematic diagram showing the state at the end of shifting, and FIG. 16 is a schematic diagram showing that the fourth speed and the fifth speed are neutral when downshifting.
Here, in order to simplify the description, only the upshifting from the fourth speed (lower gear) to the fifth gear (upper gear) will be described. The same applies to shift-up of other stages.

  13 to 15 show the movement at the time of shifting up, and FIG. 16 shows the completion of shifting down. Since drive torque is applied to the fourth-speed clutch teeth 25a in FIG. 13, the clutch ring 63 is brought into 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 the 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 meshes with the fifth gear 27, and the fourth gear 25 and the fifth gear 27 mesh simultaneously.

  At this time, irrespective of the engine output torque, a coasting torque is generated on the fourth speed side and a drive torque is generated on the fifth speed side due to the mechanically necessary internal circulation torque due to the simultaneous meshing. This torque acts on the inclined surfaces of the cam grooves 69 and 67 to generate a thrust in the clutch ring 63 at the fourth speed position in the right neutral direction in the drawing and a clutch ring 61 at the fifth speed position in the direction to deepen the right engagement in the drawing. Then, the respective clutch rings 63 and 61 are moved to predetermined positions, and the upshift to the fifth speed is completed as shown in FIG.

  The feature 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 slopes of the cam grooves 65, 67, 69. The rotation of the clutch rings 59, 61, 63 on the lower shift stage is delayed with respect to the cam rings 53, 55, 57, and the rotation of the clutch rings 59, 61, 63 on the upper shift stage is advanced. In such a situation, the relative speed of the clutch teeth 19a, 21a, 23a, 25a, 27a, 29a 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 generate a shift shock. ease.

[Shift up when engine brake is working]
If the upshift is performed while the engine brake is applied, the shift is performed without the clutch ring 63 at the fourth speed position being at the standby position. At this time, the clutch ring 61 meshes with the fifth speed gear 27 due to the shift-up operation, and further coasting torque acts on the fourth speed. However, the clutch ring 63 at the fourth speed is not in the disengagement standby position, so it is in the neutral direction. No thrust component is generated.

  However, the absolute value of the coasting torque during engine braking is smaller than the torque during acceleration, and the frictional force acting on the dog 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.

This thrust passes through the shift fork 85, shift rod 107, shift arm 115, shift groove 123 and shift groove 125 of the shift drum 119 at the fifth speed position, and the shift rod 109 and shift fork 87 at the fourth speed position. To move the clutch ring 63 at the fourth speed position to the disengagement standby position in the neutral direction on the right side in the figure. Therefore, even in such a case, there is no problem in upshifting.
The shift groove 123 and the shift groove 125 are cut so as to perform such a cooperative operation, and the thrust force from the shift arm 115 side causes the shift drum 119 to rotate slightly through the shift groove 123. The thrust force is transmitted to the shift arm 117 via the shift groove 125.

  Accordingly, the mechanism for bringing the clutch rings 59, 61, 63 into a state in which the first to third meshing clutches 47, 49, 51 mesh with each other at the second meshing position is constituted by the clutches of the lower gear stage and the upper gear stage. The shift forks 77, 85, 87 of the rings 59, 61, 63, the shift rods 103, 107, 109, the respective shift grooves 120, 123, 125 of the shift drum 119, and the shift arms 111, 115, 117 and the above. The shift drum 119 is provided.

  Even when the drive torque is applied, if there is no slope F, the clutch ring 63 is not located at the separation standby position. However, even in this case, the clutch ring 63 can be forcibly moved in the neutral direction by transmitting the 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 for smoother shifting.

In this embodiment, the shift operation is performed by the shift grooves 120, 121, 123, and 125 (cylindrical cams) of the shift drum 119. The flat cams or each shift rod is driven by controlled hydraulic pressure or electric motor air pressure. However, the present invention holds.
[Shift down 5th → 4th]
When decelerating, there is no need for a seamless shift as when accelerating. This is because deceleration is mainly handled by the brake, and the output from the engine is basically unrelated, so that there is no problem even if the driving torque from the engine or the engine braking torque is interrupted. Therefore, in the same manner as a normal manual transmission, first, the clutch ring 61 at the fifth gear position in the upper gear stage is moved to the neutral position shown in FIG. 16 to cut off the power, and then the clutch ring 63 is connected to the fourth gear 25. Shift down by meshing.

  Thus, the meshing state shown in FIG. 13 is obtained.

  As described above, this embodiment is characterized in that the form of meshing transition is different between upshifting and downshifting. This is due to the fact that the upper and lower shift rings 61, 63 are independent of each other, and that the shift grooves 125, 123 of the cylindrical cam 119 cooperate with each other.

  Hereinafter, a mechanism for changing the shift mode between upshifting and downshifting will be described with reference to FIG. FIG. 17 is a diagram for explaining the operation of the drum groove at the time of shifting up and shifting down.

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

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

  On the other hand, the shift arm 115 shifts from the position 115c to the position 115b1 and becomes neutral at the fourth speed and the fifth speed 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 meshes with the clutch teeth 25a of the fourth speed gear 25, and the shift down is completed in the state of FIG.

  The transmission 1 is configured such that, when the lower and upper shift clutch rings (59, 61, 63) are simultaneously engaged by the shift up operation of the shift operating section 93, the lower shift clutch rings (59, 61, 63). The gear shift is performed by generating an axial force in the disengagement direction at the gear shift, and more specifically, the clutch rings (59, 61, 63) of the lower gear and the upper gear by the shift-up operation of the gear shift operation unit 93. ), When the gears are simultaneously meshed, the clutch rings (59, 61, 63) of the lower gear stage and the upper gear stage generate the axial forces in directions different from the disengagement direction and the engagement direction, respectively, to perform the gear shift. It is.

  On the other hand, when the clutch 1 (59, 61, 63) of the lower shift stage and the upper shift stage is simultaneously engaged by the shift-down operation of the shift operating section 93, the transmission 1 shifts the clutch ring (59, 61) of the upper shift stage. , 63) to generate the axial force in the disengagement direction to perform the gear shift. More specifically, the shift-down operation of the gear shift operation section 93 causes the lower and upper gear clutch rings (59, 61) to shift. , 63) are simultaneously engaged with each other, and the clutch rings (59, 61, 63) of the lower shift stage and the upper shift stage respectively generate axial forces in directions different from the engagement direction and the disengagement direction to shift gears. It is also possible to adopt a configuration in which it is performed.

  This means that when the speed of a construction machine, an agricultural machine, a heavy truck, etc. is low and the speed energy is small and the traveling resistance is large, such as when traveling on a muddy road or climbing a hill, a downshift is required to obtain a larger driving force. In such a situation, when downshifting with a normal meshing transmission, if the driving force is interrupted even for a short time, the vehicle stops and it becomes difficult to climb a hill. According to the present invention, since the driving force can be changed without interruption, the downshift can be easily performed and the traveling can be maintained.

  The shift guide by the guide portion G of the transmission 1 may be configured to be performed by both the shift-up operation and the shift-down operation of the shift operation portion 93.

[Elastic part and damping part]
18 to 20 relate to Reference Example 1, FIG. 18 is a schematic cross-sectional view showing a transmission together with a front differential device, FIG. 19 is an enlarged cross-sectional view around a coupling portion, and FIG. FIG. 4B is an enlarged front view of an outer plate of the unit, and FIG. 4B is an enlarged front view of an inner plate of the coupling transmitting unit. The overall basic configuration of the transmission of this reference example is the same as that of reference example 1 in FIGS. 1 to 17, and in FIGS. 18 to 20, the same components as in FIGS. The characteristic portion will be further described.

  As shown in FIGS. 18 and 19, the transmission 1 of the reference example has a configuration in which the main shaft 3 performs drive input as a drive force transmission shaft 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 during 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 periphery, and has a through hole 205 formed in the shaft core. Needle bearings 207a, 207b are provided at both ends of the hollow outer shaft 201 with respect to the through hole 205. One end of the hollow outer shaft 201 protrudes out of the bearing 9 and is formed with a spline 201a.

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

  The torsion portion 203 is a portion that generates a torsional reaction force, has a slightly smaller diameter with respect to the through hole 205, and is fitted and disposed so as to be relatively rotatable. Both ends of the torsion portion 203 are supported in the through hole 205 by needle bearings 207a and 207b 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 an abutting end face. Is being done. The distal end side of the input coupling portion 209 is formed to have a slightly smaller diameter, and a spline 209a for input coupling is formed on the distal end side. The space between the base end of the input coupling portion 209 and the spline 209a is formed in a tapered shape or the like.

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

  As shown in FIGS. 19 and 20, the frictional coupling transmitting 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.

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

  The outer plate 219 and the inner plate 221 are alternately arranged, and the pressing plate 217 is arranged so as 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 is engaged with the spline 213 a of the coupling shaft 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 friction transmitting 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 friction coupling transmission unit 211 is not particularly limited as long as it has the above-described function, and a clutch using a magnetic fluid, a coupling using silicone oil and an outer plate and an inner plate, an electromagnet An electromagnetic clutch or the like consisting of a multi-plate pilot clutch and a main clutch engaged via a cam operated by the engagement force of the pilot clutch can be appropriately employed.

  With such a structure, when a drive input is input from the engine to the input coupling section 209 of the torsion bar 202, the input is performed to the outer shaft 201 via the torsion section 203, the coupling shaft section 213, and the friction coupling transmission section 211, and The operation and effect of the transmission 1 can be achieved.

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

  More specifically, when a shift shock is input to the outer shaft 201 during the shift operation, the shift shock 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 215 b to the outer plate 219, and is input from the spline 213 a to the coupling shaft 213 via a 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 between the coupling portion 209 and the input from the engine, and is absorbed by the torsion elastic force of the torsion portion 203.

  Further, when the torsion of the torsion portion 203 returns and vibrates, the friction coupling transmitting portion 211 has a damping function, and can attenuate the vibration.

  When there is a sudden drive input to the main shaft 3, the frictional coupling transmission unit 211 can exhibit a torque limiter function by slipping between the outer plate 219 and the inner plate 221.

  For this reason, it is possible to reduce the occurrence of speed change noise and protect the functional components.

  The torsional elasticity can be easily changed by changing the diameter of the torsion portion 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-like characteristic of the friction coupling transmission unit 211 can be changed by external adjustment.

  The torsion portion 203 of the torsion bar 202 can be replaced with a machined spring (registered trademark "Miki Pulley Co., Ltd."). The machined spring is a coil spring having a helical cut formed by cutting. The torsion torque can be determined by tightening with a torsion torque equal to or more than a certain value, and a reliable torque transmission can be performed. . Further, in the case of a machined spring, it is also possible to connect the outer shaft 201 and the input coupling portion 209 so as to fit between the outer periphery and the outer periphery.

  In the first embodiment, the torsion bar 202 as an elastic part and the friction coupling transmitting part 211 as a damping part are provided on the main shaft 3 side. It can also be provided on the side.

In this case, the counter shaft 5 is separated into an output portion on the output gear 135 side and a main portion on the first speed gear 19 side, and the main portion is formed as a hollow outer shaft and integrated with the output gear 135 of the output portion. The torsion portion of the coupled torsion bar is disposed so as to penetrate through the shaft portion of the outer shaft of the main portion, and a multi-plate frictional coupling transmitting portion is coupled between the end of the torsion portion and the outer shaft.
[Reference Example 2]

  FIG. 21 is a schematic cross-sectional view showing a transmission together with a front differential device according to Reference Example 2. Note that the basic configuration is the same as that of the first embodiment. The same components are denoted by the same reference numerals, and corresponding components are denoted by the same reference numerals with an A appended thereto, and redundant description will be omitted.

  The transmission 1A of the present reference example is provided with a friction coupling transmission section 211A as a damping section between the input coupling section 209 and the outer shaft 201A. That is, a spline is formed over the outer periphery of the end portion where the input coupling portion 209 and the outer shaft 201A meet, and the friction coupling transmission portion 211A is engaged with the spline.

  That is, the case 215A of the friction coupling transmission unit 211A is engaged with the spline of the outer shaft 201A, and the outer plate is spline-engaged with the case 215A. The inner plate of the friction coupling transmitting portion 211A is engaged with the spline of the input coupling portion 209, and the outer shaft 201A in which the nut 223A is screwed or press-fitted and fixed to the outer periphery of the input coupling portion 209 has a bearing 9 outside. The coupling member 210 is spline-fitted, and the coupling member 210 is fastened and fixed to the coupling shaft 213A of the torsion bar 202A by a nut 212.

  Therefore, in the present embodiment, torque can be transmitted from the torsion bar 202A to the outer shaft 201A via the coupling member 210, and the speed change 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 at the time of absorbing the speed change shock can be properly attenuated by the friction coupling transmitting unit 211A.

  In addition, the same functions and effects as those of the first embodiment can be obtained.

Note that, also in this reference example, the structure of the elastic portion and the damping portion can be provided on the counter shaft 5 side in the same manner as described above.
[Reference Example 3]

  22 and 23 relate to Reference Example 3. FIG. 22 is a schematic cross-sectional view showing a transmission together with a front differential device. FIG. 23 (A) is a view of the pressure shear ring taken along line XXIIIA-XXIIIA in FIG. FIG. 4B is a schematic cross-sectional view showing the engagement, FIG. 4B is a cross-sectional view of the center ring, FIG. 4C is a front view of the center ring, FIG. 5D is a front view of the pressure ring, and FIG. -It is sectional drawing of a ring. The basic configuration is the same as that of the first embodiment. The same components are denoted by the same reference numerals, and the corresponding components are denoted by the same reference numerals with B added thereto, and redundant description will be omitted.

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

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

  The pressure ring 237 is supported so as not to rotate relatively around the axis of the differential case 229 and to be movable in the axial direction. The support for relative rotation about the axis is provided by a pin 239 disposed between a groove on the inner surface of the differential case 229 and a concave portion on the outer peripheral surface of the pressure ring 237, and the pressure ring 237 moves along the pin 239. It is configured to be axially movable with respect to the differential case 229.

  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 mountain-shaped cam projection 227 a formed on the center ring 235 into a correspondingly shaped cam recess 227 b formed on the pressure ring 237.

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

  At this time, 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 meshing with the pinion gear 231. It rotates relative to the center ring 235.

  Due to this relative rotation, the damping cam mechanism 227 acts, and the pressure ring 237 moves outward in the axial direction. 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 projection 227a and the cam recess 227b.

  Thus, also in the present embodiment, the shift shock can be absorbed and attenuated.

  In addition, the same functions and effects as those of the first embodiment can be obtained.

Note that, also in this reference example, the structure of the elastic portion and the damping portion can be provided on the counter shaft 5 side in the same manner as described above.
[Reference Example 4]

  FIG. 24 is a schematic cross-sectional view showing an application to an ER-based transmission according to Reference Example 4. The basic configuration of the present invention is the same as that of the first embodiment.

  The transmission 1C of the present embodiment is configured to be applied to a front engine / rear drive (FR) automobile as shown in FIG.

  A guide portion G is provided at each shift speed of the transmission 1C as in the first embodiment so that a seamless shift operation can be performed via the shift operation portion 93, the moving force transmission mechanism M, the cam groove and the cam protrusion. Has become.

  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 portion 203C of the torsion bar 202C is formed integrally with the input gear 243, and the coupling of the torsion portion 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 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 transmitting portion 211C including an outer plate and an inner plate. The outer plate is spline-engaged with the outer shaft 201C, and the inner plate is The spline is engaged with the torsion portion 203C. The fastening of the outer plate and the inner plate is performed between the outer shaft 201C and the input gear 243 by the nut 212C.

  Therefore, in this embodiment, torque can be transmitted from the torsion bar 202C to the outer shaft 201C via the coupling member 210C, and the speed change shock can be absorbed by the torsional elasticity of the torsion bar 202C. Further, the torsional vibration of the torsion bar 202C with respect to the outer shaft 201C at the time of absorbing the speed change shock can be accurately attenuated by the friction coupling transmitting unit 211A.

  In addition, the same functions and effects as those of the first embodiment can be obtained.

  The structure of the front differential device 137B of Reference Example 3 can be applied to a rear differential device of an FR vehicle.

[Clutch teeth]
FIG. 25 is a cross-sectional view showing a main part of the dog clutch of the present embodiment, showing a drive dog position. The clutch teeth of this embodiment can be applied to any of FIGS.

  Since the dog clutch of FIG. 25 has the same function as the guide portion G employed in the examples of FIGS. 1 to 24, the present transmission is obtained by changing the first to third dog clutches 47, 49, and 51. The cam grooves 65, 67, 69 and the cam projections 71, 73, 75 of the guide portion G are eliminated. The clutch ring 59 is axially movably connected to the counter shaft 5 by a spline or a parallel groove, and the clutch rings 61 and 63 are axially movably connected to the main shaft 3 by a spline or a parallel groove. Is done.

  That is, a first-speed gear 19, a second-speed gear 21, a third-speed gear 23, and a fourth-speed gear, which are a plurality of speed-change gears rotatably supported on the main shaft 3 or the counter shaft 5 as a driving force transmission shaft. A plurality of gears 25, 5th gear 27, 6th gear 29 and a plurality of gears are provided for selectively coupling the gears to the main shaft 3 or the counter shaft 5 to output gear shifts. A clutch ring 59, 61, 63 that can be selectively engaged with the transmission gears on both sides by an engagement clutch, and a shift operation section 93 that selectively operates the clutch ring. It has become.

  As described in FIGS. 9 and 10, the clutch rings 59, 61, and 63 are provided with the transmission gears 1st gear 19, 3rd gear 23, 2nd gear 21, 5th gear 27, 4th gear 25, 6 A state in which the first to third dog clutches 47, 49, and 51 are meshed with each other at the first meshing position in the axial direction with respect to the speed gear 29, and a second meshing that is shallower than the first meshing position. At the meshing position, the first to third meshing clutches 47, 49, 51 can move to a meshing state.

  When the third meshing clutch 51 is described as a representative, as in FIG. 12, a guide surface 51ba is provided as shown in FIG. The guide surface 51ba is set to be inclined in the rotation direction, and when the lower and upper shift clutch rings 63, 61 are simultaneously engaged by the operation of the shift operation section 93, the guide surface 51ba is shifted to the lower shift clutch ring 63. At the second meshing position, an axial force is generated in the unmating direction.

  That is, the third dog clutch 51 has the clutch teeth 29a on the side of the sixth speed gear 29, which is the transmission gear, and the clutch teeth 51b on the side of the clutch ring 63, and the guide surface 51ba is formed of the clutch teeth 51b, 29a. On the other hand, the clutch ring 63 is provided on the other end 51b to generate an axial force in the disengagement direction on the clutch ring 63 by the relative guide of the tip 29aa of the other one 29a of the clutch teeth 51b, 29a during the coasting torque.

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

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

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

  The drive slope F is formed on the tooth base on the other side in the rotation direction of one of the clutch teeth 51b and 29a, and is relatively formed between the clutch teeth 51b and the tip 29ad of the other 29a of the clutch teeth 51b during transmission of the driving force. The guide ring is used to move the clutch ring 63 from the first meshing position to the second meshing position.

  Therefore, a mechanism for bringing the clutch ring 63 into a state in which the third meshing clutch 51 is meshed at the second meshing position is formed at the root of one of the clutch teeth 51b and 29a in the rotation direction. When the driving force is transmitted, the clutch ring 63 is moved from the first meshing position to the second meshing position by a relative guide between the clutch teeth 51b and the tip portion 29aa of the other 29a of the clutch teeth 51a. is there. The same applies to the first and second dog clutches 47 and 49 for the clutch rings 59 and 61.

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

  A drive meshing surface 29ae that is continuous with the tip 29ad of the other 29a of the clutch teeth 51b, 29a is formed to be inclined corresponding to the drive meshing surface 51bc.

  Note that the guide surface 51ba and the drive slope F can be formed on the side of the sixth speed gear 29, which is a transmission gear.

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

[drive]
When the third meshing clutch 51 is meshed and connected to, for example, the sixth speed gear 29 and a drive torque is applied, the clutch ring 63 is moved by the drive 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 provided with an appropriate axial play for the guide of the shift arm 117.

  By this movement, the clutch ring 63 is brought into the disengagement standby position in FIG. 25 which has moved to the meshing disengagement side from the coast meshing position (see FIGS. 9 and 12A).

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

Next, when the drive torque changes in the coast direction, the clutch teeth 29a are separated from the drive engagement surfaces 51bc and 29ae . At this time, due to the energy of the spring 133b, a deep meshing state is established at the first meshing position by the action of the concave portion 129b and the ball 133a (see FIGS. 9 and 12A). In this state, the coast engagement surface 29ab shown in FIG. 25 abuts against the coast engagement surface 51bb, so that no thrust force is generated on the clutch ring 63.

[Shift up 4th → 5th]
The operation at the time of shifting up in FIGS. 13 to 15 will be described again with reference to FIG. Although FIG. 25 illustrates the third meshing clutch 51 on the side of the sixth gear 29, the first and second meshing clutches 47 and 49 have the same structure. The surface and the like will be described with reference to FIG. 25 using the same reference numerals.

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

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

  At this time, when the 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 meshes with the fifth gear 27, and the fourth gear 25 and the fifth gear 27 mesh simultaneously.

  At this time, as described above, regardless of the engine output torque, a coasting torque is generated on the fourth speed side and a drive torque is generated on the fifth speed side due to the mechanically inevitable internal circulation torque due to the simultaneous meshing. This torque generates a thrust force in the direction of disengagement (neutral) to the clutch ring 63 at the fourth speed position due to the action of the slope of the guide surface 51ba, and the clutch ring 63 moves from the fourth speed position to the release position. I do.

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

  With this release and engagement, the upshift 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 in FIGS.

  Therefore, the same operation and effect as described above can be obtained.

  Upshifting at other shift speeds can be performed in a similar manner. FIG. 26 is a cross-sectional view illustrating a main portion of a dog clutch according to a modification and illustrating a drive dog position.

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

  In this example, the thrust force is not generated between the drive meshing surface 51bc and the drive meshing surface 29ae at the time of simultaneous meshing, and the clutch ring on the upper gear stage is moved only by the shifting force from the gearshift operating section 93. become.

  Therefore, the drive meshing surface 51bc forms a guide surface, and the first to third meshing clutches 47, 49, and 51 operate the lower gear and the lower gear by the shift-up operation or the shift-down operation of the shift operation unit 93. When the upper-stage clutch rings (59, 61, 63) are simultaneously engaged, the lower-stage and upper-stage clutch rings (59, 61, 63) are engaged with each other by the coasting torque at the second engagement position. And guide surfaces (51ba, 51bc) for individually generating axial forces in directions different from the engaging direction and the disengaging direction.

[Prevent wear of clutch teeth]
FIG. 27 illustrates the wear of the tooth tips of the dog clutch according to the comparative example, and FIG. 27A shows one of the dog teeth and the tooth meshing viewed from the tangential direction of the clutch ring. FIG. 28 is a schematic cross-sectional view, (B) is a cross-sectional view taken along the line XXVIIB-XXVIIB of (A), FIG. 28 is a diagram illustrating wear of a tooth tip of a dog clutch according to the present embodiment, and (A) is a clutch tooth. (B) is a schematic cross-sectional view of the disengagement state of the clutch teeth as viewed from the tangential direction of the clutch ring, and FIG. It is XXXIXC-XXIIXC arrow sectional drawing of A).

  As shown in FIG. 27 (A), 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 tangential direction of the clutch ring 63, the clutch ring In the radial direction of 63, the clutch teeth 51b and the clutch teeth 29a are engaged with each other at the full length.

  In such meshing, the tip 29ad of the clutch teeth 29a repeatedly collides with the clutch teeth 51b due to repetition of meshing and disengagement, causing wear due to long-term use or the like.

  When the tip portion 29ad of the clutch tooth 29a wears, the position of the clutch tooth 29a with respect to the drive slope F slightly shifts toward the first meshing position, and the second meshing position, which is the separation standby position, shifts and separates. May not be performed smoothly.

  On the other hand, in the present embodiment, the collision avoiding slope 51be is provided on the clutch teeth 51b as shown in FIGS.

  In the clutch teeth of FIGS. 28 (A) and (B), a portion 29ada where the tip end 29ad of the clutch tooth 29a does not collide with the clutch tooth 51b at the beginning of engagement due to the collision avoiding slope 51be is formed. No or greatly reduced.

  Therefore, when the clutch ring 63 moves to the second meshing position by the relative guide between the tip portion 29ad of the clutch teeth 29a and the driving slope F of the clutch teeth 51b, a portion that does not collide with the driving slope F. Since the 29ada is relatively guided, the clutch ring 63 can be accurately moved to the second meshing position.

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

  Note that the clutch rings 59, 61, and 63 only need to exert a thrust force in the disengagement direction at the second meshing position at the time of simultaneous meshing. There is no.

1, 1A, 1B, 1C Transmission 3 Main shaft (driving force transmission shaft)
5 Counter shaft (driving force transmission axis)
19 1st gear (shift gear)
21 2nd gear (transmission gear)
23 3rd gear (shift gear)
25 4th gear (shift gear)
27 5th gear (shift gear)
29 6th gear (shift gear)
19a, 21a, 23a, 25a, 27a, 29a Clutch teeth 29ae Drive engagement surfaces 65, 67, 69 Cam grooves 71, 73, 75 Cam projections (projections)
77, 79, 85, 87 shift forks 103, 105, 107, 109 shift rods 111, 113, 115, 117 shift arm 119 shift drums 120, 121, 123, 125 shift grooves 131, 133 check section 47 First meshing clutch 49 Second meshing clutch 51 Third meshing clutch 47a, 47b, 49a, 49b, 51a, 51b Clutch tooth 51ba Guide surface 51bc Drive meshing surface 59, 61, 63 Clutch ring 93 Shift Operation part 201, 201A, 201C Outer shaft 202, 202A, 202C Torsion bar (elastic part)
209 Input coupling unit 211, 211A, 211C Friction coupling transmission unit (damping unit)
225 Disc spring (elastic part, elastic member)
227 Damping cam mechanism (damping part)
F Drive slope G Guide part M Moving force transmission mechanism T Transmission surface

Claims (4)

A plurality of speed-change gears rotatably supported on the driving force transmission shaft; and a plurality of speed-change gears selectively connected to the driving force transmission shaft for speed-change output. It is provided with a clutch ring capable of meshing, and a shift operation section for selectively operating the clutch ring,
When the clutch gears of the lower shift stage and the upper shift stage are simultaneously meshed by the shift-up operation or the shift-down operation of the shift operation unit, a coasting torque is generated in the clutch ring of the lower shift stage and the upper shift stage of the shift shift stage. A transmission in which a drive torque is generated in a clutch ring to generate an axial force in a disengagement direction in the clutch ring in the lower gear shift stage or the upper gear shift stage, thereby performing gear shifting,
The clutch ring and the transmission gear include clutch teeth that mesh in a rotational direction,
The clutch tooth includes a guide surface that generates a thrust force in a disengagement direction by an action of a slope by the simultaneous meshing ,
A transmission characterized in that: The transmission according to claim 1,
The clutch tooth has a drive meshing surface that is set substantially parallel to the axial direction and meshes with a drive torque.
A transmission characterized in that: A plurality of speed-change gears rotatably supported by the driving force transmission shaft; and a plurality of speed-change gears selectively provided with the speed-change gears coupled to the driving force transmission shaft to output a speed change. A clutch ring which is disposed on both sides to be selectively engaged with the transmission gears on both sides, and a shift operation section for selectively operating the clutch ring,
When the clutch gears of the lower shift stage and the upper shift stage are simultaneously engaged by the shift-up operation or the shift-down operation of the shift operation unit, a coasting torque is generated in the clutch ring of the lower shift stage and the shift-up operation of the upper shift stage. A transmission in which a drive torque is generated in a clutch ring, and an axial force in a different direction from the disengagement direction and the meshing direction is separately generated in the lower and upper gear shift clutch rings, thereby performing gear shifting.
The clutch ring and the transmission gear include clutch teeth that mesh in a rotational direction,
The clutch tooth includes a guide surface that generates a thrust force in a disengagement direction by an action of a slope by the simultaneous meshing ,
A transmission characterized in that: The transmission according to claim 3, wherein
The clutch tooth has a drive meshing surface inclined to generate a thrust force in a meshing direction by the simultaneous meshing .
A transmission characterized in that:

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