JP5049238B2 - Multi-speed transmission - Google Patents

Description

  The present invention relates to a multi-stage transmission in which a plurality of drive gears and driven gears are supported on a gear shaft parallel to each other in a state where they are always meshed with each other in each gear stage.

  In this always-meshing multi-stage transmission, one of the driving gear and the driven gear is fixed to the gear shaft, the other is rotatably supported on the gear shaft, and the gear shaft of the rotatable gear by the engaging means is mounted on the gear shaft. Shifting is performed by switching the gears to be engaged.

  A structure in which a lost motion mechanism is incorporated in a speed change driving means that is provided between a plurality of gears and a gear shaft and performs switching by switching engaging means that engage with each other has been filed earlier by the same applicant. (Patent Document 1).

Japanese Patent Application No. 2008-093701

  The shift drive means of the multi-stage transmission disclosed in Patent Document 1 includes two types of control rods arranged on the hollow central shaft of the gear shaft so as to be slidably contacted with the hollow inner peripheral surface of the gear shaft in the axial direction. It is in sliding contact with the inside of the cam rod, and lost motion mechanisms are arranged at both ends of the two types of cam rods, and each lost motion mechanism is connected to each cam rod.

  The lost motion mechanism is interlocked by interposing springs acting in the axial direction between the control rod and each cam rod, and this lost motion mechanism is housed compactly in the hollow of the gear shaft.

However, since the lost motion mechanism is arranged at both ends of the cam rod, the gear shaft becomes long, the axial width of the transmission becomes large, and the transmission becomes large.
The present invention is an improvement of such a point in a multi-stage transmission of the prior application. The object of the present invention is to compactly accommodate the lost motion mechanism of the speed change drive mechanism in the hollow of the gear shaft, and to perform the multi-stage transmission. The point is to provide a multi-stage transmission which can be miniaturized.

  In order to achieve the above object, according to a first aspect of the present invention, a plurality of drive gears and driven gears are supported on gear shafts parallel to each other in a constantly meshing state for each shift stage, and the drive gears and the driven gears are supported. A plurality of gears are fixed to the gear shaft, and engaging means provided between the other plurality of gears and the gear shaft and engaged with each other are switched and driven by the speed change driving means to perform speed change. In the machine, the engagement means includes an engagement portion provided with an engagement surface in a circumferential direction at a plurality of locations in the circumferential direction of the inner peripheral surface of each gear, and the engagement of each gear provided on the gear shaft. An engaging member that is detachably engaged with a joint portion, and a sliding contact surface that is slidably contacted with a hollow inner peripheral surface of the gear shaft, and a plurality of cam surfaces are formed at a required position in the axial direction on the sliding contact surface; A plurality of cam rods that operate by moving the engaging member, and the speed change drive means A control rod provided on the hollow central shaft of the gear shaft inside the plurality of cam rods, and interposed between an outer peripheral surface of the control rod and an inner surface of the plurality of cam rods, and the control rod and each cam rod The multi-stage transmission is provided with a lost motion mechanism that is linked via a spring acting in the axial direction.

  According to a second aspect of the present invention, in the multi-stage transmission according to the first aspect, two of the lost motion mechanisms are provided in the axial direction on the control rod, and the lost motion mechanisms are linked to the cam rods different from each other. It is characterized by doing.

  According to a third aspect of the present invention, in the multi-stage transmission according to the first or second aspect, the lost motion mechanism is configured such that the control rod is disposed at an axial position covering an outer peripheral recess formed by reducing the diameter of the control rod. Between the outer peripheral surface of the plurality of cam rods and the inner surface of the plurality of cam rods, and is locked integrally with the required cam rod, and an inner peripheral concave portion having the same axial length is formed corresponding to the outer peripheral concave portion. A cylindrical spring holder, a pair of opposing spring receivers straddling both spaces of the inner peripheral recess of the spring holder corresponding to the outer peripheral recess of the control rod, and both spring receivers interposed between the pair of spring receivers And the spring for urging in the direction of separating them.

  According to the multi-stage transmission of the first aspect, the lost motion mechanism is interposed between the outer peripheral surface of the control rod and the inner surfaces of the plurality of cam rods. The structure that overlaps the motion mechanism and the cam rod in the radial direction can avoid the expansion of the transmission in the axial direction, and the lost motion mechanism can be compactly accommodated in the hollow of the gear shaft, thereby reducing the size of the multi-stage transmission itself.

  According to the multi-stage transmission according to claim 2, two lost motion mechanisms are provided on the control rod in the axial direction, and each lost motion mechanism is linked to another cam rod, so that one control rod can be moved. On the other hand, it is possible to make two types of different movements on a plurality of cam rods to smoothly shift gears, and to make the lost motion mechanism symmetrical, thereby reducing manufacturing costs and facilitating component management during assembly.

  According to the multi-stage transmission according to claim 3, the lost motion mechanism is formed by the inner peripheral recess of the spring holder interposed between the outer peripheral surface of the control rod and the inner surfaces of the plurality of cam rods and the outer peripheral recess of the control rod. Since the spring is interposed in the space, the lost motion mechanism having the same shape can be configured on the control rod.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
A multi-stage transmission 10 according to the present embodiment is configured to be incorporated in an internal combustion engine mounted on a motorcycle.
FIG. 1 is a cross-sectional view of the multi-stage transmission 10. As shown in FIG. 1, the multi-stage transmission 10 is provided in an engine case 1 that is common to an internal combustion engine.
The engine case 1 formed by combining the left engine case 1L and the right engine case 1R which are divided into left and right forms a transmission chamber 2, in which the main gear shaft 11 and the counter gear shaft 12 are parallel to each other. The shaft is supported so as to be rotatable in the left-right direction.

  The main gear shaft 11 is rotatably supported on the side wall of the left engine case 1L and the side wall 1RR of the right engine case 1R via bearings 3L and 3R, and passes through the right bearing 3R and protrudes from the transmission chamber 2 to the right end. Is provided with a multi-plate friction clutch 5.

On the left side of the friction clutch 5, a primary driven gear 4 to which rotation of a crankshaft (not shown) is transmitted is rotatably supported by the main gear shaft 11.
The rotation of the crankshaft of the internal combustion engine is transmitted from the primary driven gear 4 to the main gear shaft 11 via the engaged friction clutch 5.

  On the other hand, the counter gear shaft 12 is also rotatably supported on the side wall of the left engine case 1L and the side wall 1RR of the right engine case 1R via bearings 7L and 7R, and protrudes from the transmission chamber 2 through the left bearing 7L. An output sprocket (not shown) is fixed to the left end by spline fitting.

  A drive chain wound around the output sprocket is wound around a sprocket that drives a rear wheel (not shown) behind, and the rotational power of the counter gear shaft 12 is transmitted to the rear wheel so that the vehicle travels.

On the main gear shaft 11, a drive transmission gear m group is configured between the left and right bearings 3L, 3R so as to be rotatable integrally with the main gear shaft 11.
A first drive transmission gear m1 is formed integrally with the main gear shaft 11 along the right bearing 3R, and a spline formed between the first drive transmission gear m1 of the main gear shaft 11 and the left bearing 3L is viewed from the right. The second, third, fourth, fifth, and sixth drive transmission gears m2, m3, m4, m5, and m6, whose diameters are sequentially increased to the left, are spline-fitted.

On the other hand, on the counter gear shaft 12, a group of driven transmission gears n is rotatably supported via an annular bearing collar member 13 between the left and right bearings 7L and 7R.
In the counter gear shaft 12, a right end bearing collar member 13 is provided through a collar member 14R interposed to the left of the right bearing 7R, and an outer case is provided through a collar member 14L interposed to the right of the left bearing 7L. Five bearing collar members 13 are packaged at equal intervals between the bearing collar member 13 at the left end, and a total of seven bearing collar members 13 straddle between adjacent bearing collar members 13 and 13. The first, second, third, fourth, fifth, and sixth driven transmission gears n1, n2, n3, n4, n5, and n6, whose diameters are sequentially reduced from right to left, are rotatably supported. .

  The first, second, third, fourth, fifth, and sixth drive transmission gears m1, m2, m3, m4, m5, and m6 that rotate integrally with the main gear shaft 11 are rotatable on the counter gear shaft 12. The corresponding first, second, third, fourth, fifth and sixth driven transmission gears n1, n2, n3, n4, n5 and n6 are always meshed with each other.

  The meshing of the first drive transmission gear m1 and the first driven transmission gear n1 constitutes the first speed with the largest reduction ratio, and the meshing of the sixth drive transmission gear m6 and the sixth driven transmission gear n6 has the smallest reduction ratio. Sixth speed is configured, and during that period, the reduction gear ratio is gradually decreased to form second speed, third speed, fourth speed, and fifth speed.

  The counter gear shaft 12 has odd-numbered gears (first, third, and fifth driven gears n1, n3, and n5) with odd-numbered gears and even-numbered gears (second, fourth, and fourth) with even-numbered gears. 6 driven transmission gears n2, n4, n6) are alternately arranged.

  The counter gear shaft 12 having a hollow cylindrical shape is incorporated so that the engagement means 20 that can be engaged with each driven transmission gear n will be described later. A total of eight cam rods C (Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe) are formed in the hollow inner peripheral surface of the counter gear shaft 12 and fit into a cam guide groove 12g described later. In addition, they are provided to be movable in the axial direction.

  A control rod 51, which is one component of the speed change driving means 50 that drives the cam rod C to change the speed, is inserted into the hollow central axis of the counter gear shaft 12, and the movement of the control rod 51 in the axial direction is lost motion. The cam rod C is moved in the axial direction in conjunction with each other via the mechanisms 52 and 53.

A mechanism for moving the control rod 51 in the axial direction is provided in the right engine case 1R.
The movement of the control rod 51 in the axial direction interlocks the cam rod C in the axial direction via the lost motion mechanisms 52 and 53, and the movement of the cam rod C is changed to each driven speed change by the engaging means 20 incorporated in the counter gear shaft 12. The gear n is selectively engaged with the counter gear shaft 12 for shifting.

  Referring to FIG. 6, the control rod 51 of the speed change drive means 50 has a cylindrical rod shape, and outer peripheral recesses 51a and 51b formed by reducing the diameter in two axial positions on the left and right sides respectively over a predetermined length. Is formed.

The left end of the control rod 51 is a two-plane width cut end portion 51aa in which a circular plane is cut out in a parallel plane, and a pin hole 51h is drilled in the two-plane width cut end portion 51aa so as to penetrate both planes. .
The right end of the control rod 51 is a male screw end portion 51bb formed with a male screw, and a hexagonal nut portion 51c is formed in front of the male screw end portion 51bb.

The lost motion mechanisms 52 and 53 are assembled corresponding to the left and right outer peripheral recesses 51a and 51b of the control rod 51, respectively.
The left and right lost motion mechanisms 52, 53 are arranged so as to be symmetrical with respect to each other.

  The left lost motion mechanism 52 has a spring holder 52h into which a control rod 51 is slidably inserted and is configured by connecting a long holder 52hl and a short holder 52hs, and corresponds to the outer peripheral recess 51a of the control rod 51 on the inner peripheral surface. An inner peripheral recess 52ha is formed.

  When the control rod 51 is passed through the spring holder 52h and the spring holder 52h is positioned in the outer peripheral recess 51a, the inner peripheral recess 52ha of the spring holder 52h and the outer peripheral recess 51a of the control rod 51 constitute a common space. To do.

A pair of left and right cotters 52c and 52c, which are spring receivers, are fitted oppositely so as to straddle both spaces of the inner peripheral recess 52ha of the spring holder 52h and the outer peripheral recess 51a of the control rod 51, and the control is performed between the two cotters 52c and 52c A compression coil spring 52 s wound around the rod 51 is interposed to urge both the cotters 52 c and 52 c in a separating direction.
The cotter 52c has a hollow disk shape in which the inner diameter of the inner peripheral recess 52ha of the spring holder 52h is the outer diameter, and the outer diameter of the outer peripheral recess 51a of the control rod 51 is the inner diameter. Yes.

The right lost motion mechanism 53 (spring holder 53h, long holder 53hl, short holder 53hs, inner peripheral recess 53ha, cotter 53c, compression coil spring 53s) has the same structure and is disposed in the outer peripheral recess 51b of the control rod 51. The
Therefore, when the control rod 51 moves in the axial direction, the spring holders 52h, 53h move in the axial direction via the compression coil springs 52s, 53s of the left and right lost motion mechanisms 52, 53.

  Eight cam rods C (Cao, Cao, Cae, Cae, Cbo, Cbo) are provided on the outer peripheral surfaces of the spring holders 52h, 53h of the lost motion mechanisms 52, 53 attached to the left and right outer peripheral recesses 51a, 51b of the control rod 51. , Cbe, Cbe) are in contact with each other at the radiation position (see FIG. 7).

The cam rod C is a rectangular rod-like member having a rectangular cross section and extending in the axial direction. The outer peripheral side opposite to the inner peripheral side contacting the spring holders 52h, 53h forms a cam surface, and the cam surface Grooves v are formed at the required three locations, and a pair of locking claws p that locks either one of the spring holders 52h and 53h from the left and right protrude from the inner peripheral side surface.
Since the cam rod C is a rectangular prismatic member having a simple cross section and a generally simple outer shape, the cam rod C can be easily manufactured.

  The cam rods Cao, Cbo for odd-numbered stages formed with cam grooves v1, v3, v5 at three positions corresponding to the odd-numbered stage gears (first, third, fifth driven transmission gears n1, n3, n5) There are two types of rotation (rotation direction in which force is applied from the driven transmission gear n to the counter gear shaft 12 during acceleration) and reverse rotation (rotation direction in which force is applied from the driven transmission gear n to the counter gear shaft 12 during deceleration). One forward rotation odd-stage cam rod Cao has an engaging claw p that engages with the right spring holder 53h on the inner peripheral side, and the other reverse rotation odd-stage cam rod Cbo has a left spring holder 52h on the inner peripheral side. There is a locking claw p that locks to (see FIG. 7).

  Similarly, cam rods Cae for even-numbered stages formed at three positions corresponding to even-numbered gears (second, fourth and sixth driven transmission gears n2, n4, n6) with even-numbered gear grooves v2, v4, v6. , Cbe are of two types, forward rotation and reverse rotation, and one forward rotation even-stage cam rod Cae has a locking claw p that locks to the left spring holder 52h on the inner peripheral side, The reverse rotation even-stage cam rod Cbe has a locking claw p that locks to the right spring holder 53h on the inner peripheral side surface (see FIG. 7).

  Accordingly, when the control rod 51 is moved in the axial direction, the positive rotation odd-numbered cam rod Cao and the reverse-rotating even-numbered cam rod Cbe are linked in the axial direction together with the spring holder 53h via the compression coil spring 53s of the lost motion mechanism 53 on the right side. Then, the reverse rotation odd stage cam rod Cbo and the forward rotation even stage cam rod Cae are interlocked in the axial direction together with the spring holder 52h via the coil spring 52s of the left lost motion mechanism 52.

  As shown in FIG. 7, a cylindrical control rod operating element 55 is attached to the right end portion on the right side of the nut portion 51c of the control rod 51 via a ball bearing 56 fitted inside.

  Two ball bearings 56 are connected in the axial direction. The ball bearings 56 are inserted into the right end portion on the right side of the nut portion 51c of the control rod 51, and are engaged with the nut portion 51c by a nut 57 screwed into the male screw end portion 51bb. It is sandwiched and fastened.

Therefore, the control rod operator 55 holds the right end portion of the control rod 51 rotatably.
A pin hole 55h pierced in the diametrical direction is formed in a cylindrical portion extending to the right side of the nut 57 to which the control rod operating element 55 is screwed, and the shift pin 58 penetrates the pin hole 55h.
Note that the engagement pin 59 passes through the pin hole 51h formed in the two-surface width cut end portion 51aa at the left end of the control rod 51.

The shift pin 58 penetrated by the control rod operating element 55 is protruded at both ends with reference to FIG.
A groove 60 is formed in the guide portion 1Ra projecting to the right of the side wall 1RR of the right engine case 1R so as to be directed in the left-right direction. One end head of the shift pin 58 projecting on the groove 60 is slidable. The shift pin 58 is prevented from rotating by fitting.

  A support shaft 65 is implanted in the side wall 1RR so as to protrude rightward, and a shift drum 67 is rotatably supported on the support shaft 65 via a bearing 66. A shift groove 67v of the shift drum 67 is provided. The other end of the shift pin 58 is slidably fitted.

  The shift groove 67v of the shift drum 67 is formed so as to draw a spiral on the outer peripheral surface of the drum, and each gear position from the first speed to the sixth speed at every predetermined rotation angle (for example, 60 degrees) therebetween. And the neutral position is formed in the middle.

Therefore, the rotation of the shift drum 67 moves the shift pin 58 fitted in the shift groove 67v together with the control rod operator 55 in the axial direction.
Since the control rod operating element 55 holds the right end portion of the control rod 51 rotatably, the rotation of the shift drum 67 eventually moves the control rod 51 in the axial direction.

The shift drum 67 is rotated via shift transmission means (not shown) by manual operation of a shift select lever (not shown).
The shift transmission means is provided with a mechanism such as a shift cam member that stably holds the shift drum 67 at the gear position for each predetermined angle, and the operation power of the shift select lever is transmitted to a gear 67g formed on the side edge of the shift drum 67. Then, the shift drum 67 is sequentially rotated to the gear position.

  As described above, the shift drive means 50 moves in the axial direction while the shift drum 67 is rotated by manual operation of the shift select lever, and the rotation of the shift drum 67 guides the shift pin 58 fitted in the shift groove 67v. Then, the movement of the shift pin 58 moves the control rod 51 in the axial direction via the control rod operator 55, and the movement of the control rod 51 moves through the eight motion rods Cao of the engaging means 20 via the lost motion mechanisms 52 and 53. , Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe.

The control rod 51 assembled with the lost motion mechanisms 52 and 53 is inserted into the hollow of the counter gear shaft 12 and disposed on the central shaft.
The hollow cylindrical counter gear shaft 12 has an inner diameter substantially equal to the outer diameter of the spring holders 52h and 53h of the lost motion mechanisms 52 and 53, and the spring holders 52h and 53h attached to the control rod 51 are slidably fitted. Insert.

Then, eight cam guide grooves 12g having a rectangular cross section are formed extending in the axial direction at eight radial positions on the hollow inner peripheral surface of the counter gear shaft 12 (see FIG. 9).
The eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe are slidably fitted into the corresponding cam guide grooves 12g in the arrangement shown in FIG.
The same kind of cam rod C is disposed at a symmetrical position.
The cam guide groove 12g, which serves as a detent for the cam member C with respect to the counter gear shaft 12, has a simple U-shaped cross section and can be easily machined.

  The cam guide groove 12g has a depth equal to the radial width of the cam rod C. Therefore, the cam surface which is the outer peripheral side surface of the cam rod C is in sliding contact with the bottom surface of the cam guide groove 12g, and the inner peripheral side surface is substantially the same as the hollow inner peripheral surface. A locking claw p which forms a surface and contacts the outer peripheral surface of the spring holders 52h and 53h and protrudes from the inner peripheral side surface grips either of the spring holders 52h and 53h from both sides.

  The counter gear shaft 12 having a hollow cylindrical shape includes a left cylindrical portion 12b and a right cylindrical portion whose outer diameters are reduced on both the left and right sides of the central cylindrical portion 12a on which the driven transmission gear n is pivotally supported via a bearing collar member 13. 12c is formed (see FIG. 8).

  The left cylindrical portion 12b is fitted with a bearing 7L via a washer 14L, and a spline 12s is partially formed to fit an output sprocket (not shown), while the right cylindrical portion 12c is fitted with a washer. The bearing 7R is fitted through 14R (see FIGS. 1, 2 and 3).

In the hollow of the counter gear shaft 12, the inner diameter of the small-diameter inner surface where the cam guide groove 12g is formed is equal to the outer diameter of the spring holders 52h, 53h, and the inner diameters on both sides of the small-diameter inner peripheral surface are the cam guide grooves 12g. A large-diameter inner peripheral surface that forms substantially the same peripheral surface as the bottom surface is formed (see FIGS. 2 and 3).
About half of the control rod operating element 55 is inserted inside the enlarged inner diameter part on the right side.

The engagement pin 59 that penetrates the pin hole 51h formed in the two-sided width cut end portion 51aa at the left end of the control rod 51 engages the cam guide grooves 12g and 12g at symmetrical positions to prevent rotation. Therefore, the control rod 51 rotates relative to the counter gear shaft 12 while being relatively movable in the axial direction, and the rotation of the control rod 51 is integrally rotated.
With a simple configuration in which the engaging pin 59 is engaged using the cam guide groove 12g, the control rod 51 can be prevented from rotating with respect to the counter gear shaft 12.

  Thus, when the control rod 51, the lost motion mechanisms 52 and 53, and the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe are incorporated into the hollow of the counter gear shaft 12, all of these are incorporated. When the control rod 51 rotates together in the axial direction, the reverse rotation odd-numbered cam rod Cbo and the forward rotation even-numbered cam rod Cae are linked in the axial direction via the coil spring 52s of the left lost motion mechanism 52, and the right side Through the coil spring 53s of the lost motion mechanism 53, the forward rotation odd stage cam rod Cao and the reverse rotation even stage cam rod Cbe are interlocked in the axial direction.

  Since the lost motion mechanisms 52 and 53 are arranged in the axial direction of the counter gear shaft 12 and interposed between the outer peripheral surface of the control rod 51 and the inner surfaces of the plurality of cam rods C, the lost motion mechanisms 52 and 53 are located in the hollow of the counter gear shaft 12. The control rod 51, the lost motion mechanism 52, 53, and the cam rod C are overlapped in the radial direction to avoid the expansion of the multi-stage transmission 10 in the axial direction, and the lost motion mechanism 52, 53 can be compactly accommodated in the hollow of the counter gear shaft 12. The housing can be accommodated to reduce the size of the multi-stage transmission 10 itself.

  Two lost motion mechanisms 52 and 53 are provided on the control rod 51 in the axial direction, and each lost motion mechanism 52 and 53 is linked to another cam rod C. The cam rod C can be made to move in two different ways to make the speed change smooth, and the lost motion mechanisms 52 and 53 are made symmetrical to reduce the manufacturing cost and facilitate the management of parts during assembly. .

  Lost motion mechanisms 52 and 53 are interposed between the outer peripheral surface of the control rod 51 and the inner surfaces of the plurality of cam rods C. The inner peripheral recesses 52ha and 53ha of the spring holders 52h and 53h and the outer peripheral recess 51a of the control rod 51 Since the coil springs 52 s and 53 s are interposed in the space formed by 51 b, the lost motion mechanisms 52 and 53 having the same shape can be configured on the control rod 51.

  As shown in FIG. 8, the central cylindrical portion 12a on which the driven transmission gear n is pivotally supported via the bearing collar member 13 of the counter gear shaft 12 has a large outer diameter and is configured to be thick. A narrow circumferential groove 12cv that goes around in the circumferential direction on the outer periphery corresponds to the first, second, third, fourth, fifth, and sixth driven transmission gears n1, n2, n3, n4, n5, and n6. In addition, six axial grooves 12av are formed at equal intervals in the axial direction, and four axial grooves 12av oriented in the axial direction are formed at equal intervals in the circumferential direction.

  Further, on the outer peripheral portion of the central cylindrical portion 12a of the counter gear shaft 12, four portions defined by four axial grooves 12av are adjacent to each other in the circumferential direction. A long rectangular recess 12p that is elongated equally between the grooves 12av and 12av in the left and right direction, and a short length in which the groove width of the circumferential groove 12cv is evenly enlarged in the left and right directions in part between the adjacent axial grooves 12av and 12av. Rectangular recesses 12q are alternately formed in the axial direction.

Spring receiving portions 12d and 12d are formed in two axially elongated oval shapes in the axial direction and slightly recessed over the circumferential groove 12cv at two locations on the bottom surface of the long rectangular recess 12p.
Further, a pin hole 12h is formed in the radial direction up to the cam guide groove 12g on the circumferential groove 12cv at a thick portion between the short rectangular recess 12q and the axial groove 12av.

That is, the pin hole 12h is drilled in the radial direction of the cam guide groove 12g formed at eight locations in the circumferential direction from the hollow inner peripheral surface of the counter gear shaft 12.
Four pin holes 12h are formed on each circumferential groove 12cv.

The spring receiving portion 12d is provided with a compression spring 22 wound in an elliptical shape with its end fitted.
A pin member 23 is slidably inserted into the pin hole 12h.
The cam guide groove 12g communicating with the pin hole 12h is smaller than the outer diameter width of the pin member 23.
Therefore, the pin member 23 that advances and retreats through the pin hole 12h does not fall into the cam guide groove 12g, so that the engagement means 20 can be easily assembled to the counter gear shaft 12.

Since the cam rod C is slidably fitted in the cam guide groove 12g, the pin member 23 fitted in the pin hole 12h comes into contact with the cam surface of the corresponding cam rod C at the center end, and the cam rod C moves. When the cam groove v corresponds to the pin hole 12h, the pin member 23 falls into the cam groove v, and when the slidable contact surface other than the cam groove v corresponds, the pin member rides on the slidable contact surface and moves forward and backward by the movement of the cam rod C.
The advancement and retraction of the pin member 23 in the pin hole 12h causes the distal end portion of the pin member 23 to protrude outward from the bottom surface of the circumferential groove 12cv.

The swinging claw member R is formed in the circumferential groove 12cv that communicates between the long rectangular recess 12p and the short rectangular recess 12q formed on the outer peripheral portion of the central cylindrical portion 12a of the counter gear shaft 12 having the above-described structure. Is embedded, and a support pin 26 is embedded in the axial groove 12av to pivotally support the swing claw member R.
FIG. 11 shows a state in which all the swinging claw members R are assembled in this way.

  In the exploded perspective view of FIG. 10, the circumferential grooves 12cv, the long rectangular recesses 12p, and the short rectangular recesses 12q corresponding to the odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5) are embedded. Four oscillating claw members R, and circumferential grooves 12cv and long rectangular recesses 12p corresponding to even-numbered even gears (second, fourth and sixth driven transmission gears n2, n4, n6), The four swinging claw members R embedded in the short rectangular recess 12q are illustrated in a posture maintaining the relative angular positional relationship with each other, and in addition, a support pin that pivotally supports each swinging claw member R. 26 and a compression spring 22 and a pin member 23 acting on each swing claw member R are shown.

  The swinging claw members R are all of the same shape, have a substantially arc shape when viewed in the axial direction, and the outer peripheral portion of the through hole through which the support shaft pin 26 penetrates in the center lacks the bearing recess Rd. A wide rectangular engagement claw Rp is formed on one side of the bearing recess Rd so as to be swingably fitted to the long rectangular recess 12p. A pin hole is formed on the other side. A narrow pin receiving portion Rr that slidably fits in the circumferential groove 12cv formed with 12h extends, and an end of the pin receiving portion Rr reaches a short rectangular recess 12q to form a wide end Rq that is widened. Yes.

In the swing claw member R, the pin receiving portion Rr is fitted in the circumferential groove 12cv in which the pin hole 12h is formed, and one engaging claw portion Rp is fitted in the long rectangular recess 12p and the bearing recess Rd is formed. The other wide end Rq is fitted in the short rectangular recess 12q, matching the axial groove 12av.
Then, the support pin 26 is fitted into the matched bearing recess Rd and the axial groove 12av.

  The swinging claw member R is formed symmetrically with respect to the circumferential groove 12cv to be fitted, and one wide rectangular engagement claw Rp is heavier than the other pin receiving part Rr and the wide end Rq, When the pin 26 is pivotally supported and rotates together with the counter gear shaft 12, the swinging claw member R swings so that the engaging claw Rp acts as a weight against the centrifugal force and protrudes in the centrifugal direction.

The swinging claw member R is formed such that the pin receiving portion Rr is narrower than the engaging claw Rp side on the opposite side with respect to the swinging center.
Further, since the pin receiving portion Rr only needs to have a width sufficient to receive the pin member 23, the swinging claw member R can be formed in a small size, and the other engaging claw portion Rp can be swung by the centrifugal force. The movement can be facilitated.

  Since the swinging claw members R adjacent to each other in the circumferential direction are assembled to the counter gear shaft 12 in a symmetrical attitude, the engaging claw portions Rp, Rp facing each other with a predetermined interval are the same long rectangular recess 12p. The other wide end Rq adjacent to each other is fitted into a common short rectangular recess 12q.

  A compression spring 22 supported at one end by a spring receiving portion 12d of the counter gear shaft 12 is interposed inside the engaging claw portion Rp of the swing claw member R, and is inserted into the pin hole 12h inside the pin receiving portion Rr. The pin member 23 is interposed between the cam rod C and the pin member 23.

  In this way, the swing claw member R is pivotally supported by the support pin 26 and is embedded in the long rectangular recess 12p, the short rectangular recess 12q, and the circumferential groove 12cv of the counter gear shaft 12, The engaging claw portion Rp is urged outward by the compression spring 22, and the other pin receiving portion Rr is pressed by the advancement and retraction of the pin member 23, so that the oscillating claw member resists the urging force of the compression spring 22. R swings.

When the pin member 23 advances in the centrifugal direction and swings the swinging claw member R, the swinging claw member R has the engagement claw portion Rp submerged in the long rectangular recess 12p and the central cylinder of the counter gear shaft 12 There is nothing that protrudes outward from the outer peripheral surface of the portion 12a.
When the pin member 23 is retracted, the engaging claw Rp biased by the compression spring 22 protrudes outward from the outer peripheral surface of the central cylindrical portion 12a of the counter gear shaft 12, and can be engaged with the driven transmission gear n. To do.

  Since the compression spring 22 is interposed between the inner side surface of the engaging claw Rp of the swing claw member R and the long rectangular recess 12p of the counter gear shaft 12, the space dedicated to the spring is not required in the axial direction. The size of the counter gear shaft 12 in the axial direction can be avoided, and the compression spring 22 is arranged in the center of the axial width of the swing claw member R so that the swing claw member R itself is disposed on both sides in the axial direction. Two types of swinging claw members that can be formed symmetrically and thus engaged and disengaged in both directions of the relative rotational direction of the driven transmission gear n and the counter gear shaft 12 are the same shape of the swinging claw member R. It is not necessary to prepare swinging claw members having different shapes.

  The compression spring 22 has an elliptical shape whose major axis is the axial direction of the counter gear shaft 12. The elliptical compression spring 22 has a major axis larger than the width of the pin receiving portion Rr of the swinging claw member R, and the pin receiving portion Rr. Since the counter gear shaft 12 can be easily machined and the swinging claw member R can be stabilized stably. The counter gear shaft 12 can be assembled.

  Four swinging claw members R corresponding to odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5) and even-numbered gears (second, fourth, and sixth driven gears) The four swinging claw members R corresponding to the transmission gears n2, n4, n6) are in a relative angular position relationship rotated 90 degrees around the axis.

  Four swinging claw members R corresponding to the odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5) are in contact with each other in the forward rotation direction of the gear, and each odd-stage driven transmission gear n1. , N3, n5 and the counter gear shaft 12 are engaged with each other so as to rotate in synchronization with each other, and the odd-numbered driven gears n1, n3 are in contact with each other in the reverse rotation direction of the gear. , N5 and counter gear shaft 12 are provided with a pair of counter-rotating odd-numbered engaging members Rbo that are engaged so as to rotate in synchronization with each other at symmetrical positions.

  Similarly, the four swinging claw members R corresponding to the even-numbered gears (second, fourth, and sixth driven transmission gears n2, n4, and n6) are brought into contact with each other in the forward rotation direction of the gears, and each even-numbered gear is driven. A forward rotation even-numbered-stage swinging claw member Rae engaged so that the transmission gears n2, n4, n6 and the counter gear shaft 12 rotate in synchronization with each other, and the even-numbered driven gears in contact with each other in the reverse rotation direction of the gear. A pair of counter-rotating even-numbered engaging members Rbe that are engaged so that n2, n4, and n6 and the counter gear shaft 12 rotate synchronously are provided in pairs at symmetrical positions.

The forward rotation odd-stage swinging claw member Rao is swung by the pin member 23 that moves forward and backward by the movement of the forward-rotation odd-stage cam rod Cao, and the reverse-rotation odd-stage engagement member Rbo is moved by the reverse-rotation odd-stage cam rod Cbo. It swings by the pin member 23 that advances and retreats by
Similarly, the forward rotating even-stage swinging claw member Rae is swung by the pin member 23 that moves forward and backward by the movement of the forward-rotating even-numbered cam rod Cae, and the reverse-rotating even-numbered engaging member Rbe is the reverse-rotating even-numbered cam rod. The pin member 23 is moved back and forth by the movement of Cbe to swing.

  When the engagement means 20 is incorporated in the counter gear shaft 12, first, the right end bearing collar member 13 is externally mounted on the outer peripheral end of the central cylindrical portion 12a, and the support pin 26 is inserted into the axial groove 12av inside the bearing collar member 13. The right end engaging means 20 is incorporated so that one end of the shaft is inserted, and the next bearing collar member 13 is packaged so as to cover the other end of the support pin 26, and then the next stage engagement is performed in the same manner as the previous stage. The incorporation of the combining means 20 is sequentially repeated, and finally the bearing collar member 13 at the left end is packaged to finish.

As shown in FIG. 12, the bearing collar member 13 is sheathed in an axial position other than the long rectangular recess 12p and the short rectangular recess 12q of the central cylindrical portion 12a, and is continuously embedded in a line in the axial groove 12av. The support pin 26 is disposed across the adjacent support pins 26 and 26 to prevent the support pin 26 and the swinging claw member R from falling off.
Since the support pin 26 embedded in the axial groove 12av of the central cylindrical portion 12a of the counter gear shaft 12 is embedded at a depth in contact with the outer peripheral surface of the central cylindrical portion 12a, when the bearing collar member 13 is sheathed. It is fixed without play.

Seven bearing collar members 13 are mounted on the counter gear shaft 12 at equal intervals, and the driven transmission gear n is rotatably supported so as to straddle between the adjacent bearing collar members 13 and 13.
Each driven transmission gear n has a notch formed in the left and right inner periphery (the left and right periphery of the inner peripheral surface), and a thin annular protrusion 30 is formed between the left and right notches. The left and right bearing collar members 13 and 13 are slidably engaged with the notches so as to be sandwiched (see FIGS. 2 and 3).

The protrusions 30 on the inner peripheral surface of each driven transmission gear n have six engaging projections 31 formed at equal intervals in the circumferential direction (see FIGS. 2, 3, 4 and 5).
The engagement convex portion 31 has a thin arc shape when viewed from the side (in the axial direction shown in FIGS. 4 and 5), and both end surfaces in the circumferential direction engage with the engagement claw portion Rp of the swing claw member R. An engagement surface is formed.

  The forward rotation odd-numbered swinging claw member Rao (forward rotation even-numbered swinging claw member Rae) and the reverse rotation odd-numbered step engagement member Rbo (reverse rotation even-numbered step engagement member Rbe) Rp and Rp are extended, and the positive rotation odd-numbered swinging claw member Rao (positive rotation even-numbered swinging claw member Rae) is an engagement convex portion in the positive rotation direction of the driven transmission gear n (and the counter gear shaft 12). The reverse rotation odd-numbered engagement member Rbo (reverse rotation even-numbered engagement member Rbe) contacts and engages the engagement convex portion 31 in the reverse rotation direction of the driven transmission gear n. To do.

  It should be noted that the forward rotation odd-numbered swinging claw member Rao (forward rotation even-numbered swinging claw member Rae) is not engaged in the reverse rotation direction of the driven transmission gear n even if the engagement claw portion Rp protrudes to the outside. In addition, the reverse rotation odd-numbered engagement member Rbo (reverse rotation even-numbered engagement member Rbe) is not engaged in the forward rotation direction of the driven transmission gear n even if the engagement claw Rp protrudes outward.

A procedure for assembling the above engaging means 20 to the counter gear shaft 12 will be described.
The left and right lost motion mechanisms 52 and 53 are assembled to the control rod 51 to which the control operation element 55 and the engagement pin 59 are attached, and eight cam rods Cao, Cao, Cae, Cae, In a state where Cbo, Cbo, Cbe, and Cbe are disposed, the counter gear shaft 12 is inserted into the hollow.

At that time, the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe are respectively inserted into the corresponding eight cam guide grooves 12g.
The left and right movement positions of the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe with respect to the counter gear shaft 12 are set to the neutral position.

The counter gear shaft 12 in such a state is set to a posture in which the left side is up.
First, as shown by a solid line in FIG. 12, after the outermost bearing collar member 13 is sheathed at the lower end (right end) of the central cylindrical portion 12a, the circumferential groove 12cv corresponding to the lowermost first driven transmission gear n1. A pin member 23 is inserted into the pin hole 12h, one end of the compression spring 22 is supported by the spring receiving portion 12d, and the swinging claw member R is fitted into the long rectangular recess 12p, the short rectangular recess 12q, and the circumferential groove 12cv. The pivot pin 26 is fitted into the axial groove 12av inside the bearing collar member 13 at the right end and simultaneously fitted into the bearing recess Rd of the swing claw member R to assemble the swing claw member R.

  The cam rod C is in the neutral position, and the pin member 23 advances in contact with the sliding contact surface other than the cam groove and presses the pin receiving portion Rq of the swinging claw member R from the inside to resist the urging force of the compression spring 22. Thus, the swinging engagement claw Rp is immersed in the long rectangular recess 12p so that there is nothing protruding outward from the outer peripheral surface of the central cylindrical portion 12a.

  When the four swinging claw members R in the circumferential groove 12cv corresponding to the first driven transmission gear n1 are assembled, the first driven transmission gear n1 is inserted from above and the first driven transmission gear n1 protrudes into the bearing collar member 13. The second bearing collar member 13 is inserted from above and engaged with the notch of the first driven transmission gear n1 so that the counter gear shaft 12 is in a predetermined position. The first driven transmission gear n1 is axially positioned and attached.

Next, the engaging means 20 for the second driven transmission gear n2 is assembled, the second driven transmission gear n2 is attached, and thereafter, this operation is repeated and the remaining third, fourth, fifth and sixth driven transmission gears. n3, n4, n5, and n6 are sequentially assembled, and finally the seventh bearing collar member 13 is packaged.

With the six driven transmission gears n assembled to the counter gear shaft 12, the counter gear shaft 12 is fitted to the side wall 1RR of the left engine case 1L and the right engine case 1R as shown in FIG. If the bearings 7L and 7R are rotatably supported so as to be sandwiched between the collar members 14L and 14R, the six driven transmission gears n and the seven bearing collar members 13 are alternately combined to the left and right. And is positioned in the axial direction.
The bearing collar member 13 supports the axial force of each driven transmission gear n and can receive axial positioning and thrust force.

  In this way, the first, second, third, fourth, fifth and sixth driven transmission gears n1, n2, n3, n4, n5, and n6 are freely rotatable on the counter gear shaft 12 via the bearing collar member 13. Is pivotally supported.

  Since the cam rod C is in the neutral position, all the driven transmission gears n have the pin members 23 protruding from the movement positions of the cam rods C of the corresponding engaging means 20 so that the pin receiving portions Rq of the swinging claw member R are moved from the inside. In the disengaged state in which the push-up engagement claw Rp is retracted inward, it rotates freely with respect to the counter gear shaft 12.

  On the other hand, the pin member 23 enters the cam groove v by the movement position of the engagement means 20 other than the neutral position of the cam rod C, the swing claw member R swings, and the engagement claw portion Rp protrudes outward. Then, the engagement convex portion 31 of the corresponding driven transmission gear n comes into contact with the engagement claw portion Rp, and the rotation of the driven transmission gear n is transmitted to the counter gear shaft 12, or the counter gear shaft 12 Is transmitted to the driven transmission gear n.

  In the shift drive means 50, the shift drum 67 is rotated by a predetermined amount by manual operation of the shift select lever, and the rotation of the shift drum 67 is moved in the axial direction via the shift pin 58 fitted in the shift groove 67v. It moves by a predetermined amount and interlocks the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe of the engaging means 20 through the lost motion mechanisms 52, 53.

  As the cam rod C moves in the axial direction, the pin member 23 slidably in contact with the cam surface of the cam rod C moves into and out of the cam groove v to move forward and backward, swinging the swinging claw member R, and driven gear The shift is performed by releasing the engagement with n and changing the driven transmission gear n that engages with the counter gear shaft 12 by engaging with another driven transmission gear n.

  As the speed change drive means, the shift drum 67 is rotated by manual operation of the shift select lever to change speed. However, the speed change drive motor is driven to rotate the shift drum via a Geneva stop mechanism or the like. In this way, a shift may be performed.

Hereinafter, the process of shifting up from the first speed state to the second speed state in which the reduction ratio is one step smaller at the time of acceleration by driving the internal combustion engine will be described with reference to FIGS.
FIGS. 13 to 17 show the changes over time. In each figure, FIG. 13A is a sectional view in which the gears and the like in FIG. 2 (the sectional view taken along the line II-II in FIGS. 4 and 5) are omitted. Yes, FIG. (B) is a cross-sectional view in which the gears and the like in FIG. 3 (cross-sectional view taken along the line III-III in FIGS. 4 and 5) are omitted, and (c) in FIG. -C cross-sectional view (cross-sectional view of the first driven transmission gear n1), FIG. (D) is a cross-sectional view taken along the line dd (cross-sectional view of the second driven transmission gear n2) in FIGS. is there.

  The power of the internal combustion engine is transmitted to the main gear shaft 11 via the friction clutch 5, and the first, second, third, fourth, fifth and sixth drive transmission gears m2, m3, m4, m5, m6. The first, second, third, fourth, fifth, and sixth driven transmission gears n1, n2, n3, n4, n5, and n6 that are always meshed with each other are rotated at their respective rotational speeds. It is rotated with.

  FIG. 13 shows the first speed state. In FIG. 13C, the first driven transmission gear n1 rotates in the arrow direction, and in FIG. 13D, the second driven transmission gear n2 rotates in the arrow direction. Therefore, the second driven transmission gear n2 rotates at a higher speed than the first driven transmission gear n1.

Only the pin member 23 of the engaging means 20 corresponding to the first driven transmission gear n1 is in the cam groove v1 of the positive rotation odd-numbered cam rod Cao (see FIG. 13A). The positive rotation odd-numbered swinging claw member Rao protrudes outward from the engagement claw Rp, and the engaging convex portion 31 of the rotating first driven transmission gear n1 is the engagement claw of the positive rotation odd-numbered swinging claw member Rao. Engaging with Rp (see FIG. 13C), the counter gear shaft 12 is rotated together with the first driven transmission gear n1 at the same rotational speed as the first driven transmission gear n1.
In FIG. 13 to FIG. 20, a lattice hatch is applied to the swinging claw member R and the engaging convex portion 31 that transmit power effectively.

In this first speed state, in the second driven transmission gear n2, the pin member 23 of the corresponding engaging means 20 protrudes from the cam groove v2 of the even-numbered cam rods Cae and Cbe (see FIG. 13B), Since the even-numbered swinging claw members Rae and Rbe of the engaging means 20 retract the engaging claw Rp inward, they are idle.
The other third, fourth, and fifth driven transmission gears n3, n4, n5, and n6 are similarly idle (see FIGS. 13A and 13B).

  Here, when there is a manual operation of the shift select lever to shift to the second speed and the shift drum 67 rotates and the control rod 51 begins to move rightward in the axial direction, the coil springs 52s of the lost motion mechanisms 52, 53 are moved. , 53s, the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe are interlocked to move to the right in the axial direction.

  Referring to FIGS. 14A and 14C, one reverse rotation odd-numbered cam rod Cbo is operated via a pin member 23, and the reverse rotation odd-numbered swinging claw member Rbo is engaged with the first driven transmission gear n1. Since it is not engaged with the mating convex portion 31, it moves without much resistance, and the pin member 23 that has entered the cam groove v1 is pulled out and protrudes (see FIG. 14 (a)), and the reverse rotation odd number stage swinging claw The member Rbo is swung and the engaging claw Rp is retracted inward (see FIG. 14C).

  On the other hand, in the other positive rotation odd-numbered cam rod Cao, the positive rotation odd-number swinging claw member Rao that operates via the pin member 23 engages with the engagement convex portion 31 of the first driven transmission gear n1. Since the power is received from the first driven transmission gear n1, there is a considerable frictional resistance to swing and release the positive rotation odd-numbered swinging claw member Rao, and therefore the coil of the lost motion mechanism 53 Even if the positive rotation odd-numbered cam rod Cao is moved by the force of the spring 53s to cause the pin member 23 to protrude along the inclined side surface of the cam groove v1, the positive rotation odd-numbered rotation claw member Rao is pushed up and swung. The positive rotation odd-number cam cam Cao is stopped when the pin member 23 starts to rise on the inclined side surface of the cam groove v1, and the engagement cannot be released (FIGS. 14A and 14C). )reference).

In the state shown in FIG. 14, in the second driven transmission gear n2, the positive rotation even-numbered cam rod Cae moves without resistance, but the pin member 23 still does not enter the cam groove v2 and the even-numbered swinging claw member. There is no change in Rae and Rbe (see FIGS. 14B and 14D).
Since the positive rotation odd stage cam rod Cao is stopped together with the spring holder 53h of the lost motion mechanism 53 engaged therewith, the reverse rotation even stage cam rod Cbe engaged with the spring holder 53h is also stopped. .

When the forward rotation odd-numbered cam rod Cao is stopped and the control rod 51 further moves to the right and reaches the 2nd gear position, the reverse-rotation odd-numbered cam rod Cbo and the forward-rotation even-numbered cam rod Cae further to the right. As shown in FIG. 15B, the pin member 23 enters the cam groove v2 of the positive rotation even-numbered cam rod Cae, so that the positive rotation even-numbered swing claw member Rae receives the biasing force of the compression spring 22 and The engagement claw Rp is swung by the centrifugal force of the engagement claw Rp and protrudes outward (see FIG. 15D).
The reverse rotation even-numbered cam rod Cbe remains stopped, and the reverse rotation even-number swinging claw member Rbe also retracts the engagement claw Rp inside.

Then, the engaging claw 31 of the second driven transmission gear n2 that rotates at a higher speed than the counter gear shaft 12 that rotates together with the first driven transmission gear n1 protrudes outside the forward rotation even-stage swing claw member Rae. It catches up and abuts against the portion Rp (see FIG. 16D).
At this moment, referring to FIG. 16C and FIG. 16D, the contact of the engagement convex portion 31 of the second driven transmission gear n2 with the positive rotation even-numbered swing claw member Rae and the first driven speed change. The contact of the engaging projection 31 of the gear n1 with the positive rotation odd-numbered swing claw member Rao occurs simultaneously.

  Accordingly, immediately after this, the counter gear shaft 12 starts to rotate at the same rotational speed as that of the second driven transmission gear n2 by the second driven transmission gear n2 rotating at a higher speed (see FIG. 17D), and the first driven transmission gear shift is performed. The engagement claw Rp of the positive rotation odd-numbered swinging claw member Rao is separated from the engagement projection 31 of the gear n1, and the actual upshift from the first speed to the second speed is executed.

  When the engagement claw Rp of the positive rotation odd-numbered swinging claw member Rao is separated from the engagement convex portion 31 of the first driven transmission gear n1, the frictional resistance for fixing the positive rotation odd-numbered swinging claw member Rao is eliminated. The positive rotation odd-numbered cam rod Cao urged by the coil spring 53s of the lost motion mechanism 53 moves backward and the pin member 23 that has entered the cam groove v1 comes out and swings in the positive rotation odd-numbered step. The claw member Rao is swung and the engagement claw portion Rp is retracted inward (see FIG. 17C).

The movement of the forward rotation odd-numbered cam rod Cao also moves the reverse rotation even-numbered cam rod Cbe via the spring holder 53h of the lost motion mechanism 53, and the pin member 23 enters the cam groove v2 of the reverse rotation even-numbered cam rod Cbe. Then, the reverse rotation even-stage swinging claw member Rbe swings and the engaging claw Rp protrudes outward to complete the shift (see FIG. 17D).
Thus, the shifting operation from the first speed to the second speed is completed, and the state shown in FIG. 17 is the second speed state.

  As described above, when shifting up from the first speed state to the second speed state in which the reduction gear ratio is smaller by one step, as shown in FIG. 16, the engaging convex portion 31 of the first driven transmission gear n1 is rotated in an odd number of positive rotations. A second driven transmission gear n2 that rotates at a higher speed while the counter gear shaft 12 is rotating at the same speed as the first driven transmission gear n1 by contacting and engaging with the engaging claw Rp of the moving claw member Rao. Since the engaging convex portion 31 catches up and comes into contact with the engaging claw portion Rp of the forward rotation even-numbered swinging claw member Rae, the counter gear shaft 12 is rotated at a higher speed together with the second driven transmission gear n2 to change the speed. The engagement claw Rp of the positive rotation odd-numbered swinging claw member Rao is naturally separated from the engagement convex portion 31 of the first driven transmission gear n1, and the engagement is smoothly released. It can operate smoothly and perform upshifts smoothly.

  Similarly, each shift-up from 2nd to 3rd, 3rd to 4th, 4th to 5th, and 5th to 6th is performed with the driven transmission gear n engaged with the swinging claw member R. Since the driven transmission gear n with a reduction ratio of one step is engaged with the swinging claw member R and shifted up, no force is required to release the engagement and the clutch is not required for shifting. In addition, there is no loss in the switching time at the time of upshifting, there is no loss of driving force, and the shift shock is small, so that smooth upshifting can be performed.

For example, when in the first speed state, as shown in FIG. 13 (c), at the same time as the positive rotation odd-numbered stage swing claw member Rao is engaged with the engagement convex portion 31 of the first driven transmission gear n1, The engaging claw portion Rp of the other reverse rotation odd-numbered swinging claw member Rbo is in an engageable state close to the engaging convex portion 31.
Therefore, when the vehicle speed is decelerated and the driving force from the rear wheel to the counter gear shaft 12 is applied and the direction of the driving force is changed, the engagement convex portion 31 of the first driven transmission gear n1 is rotated in the forward rotation odd-numbered stage. The engagement can be quickly switched from the member Rao to the reverse rotation odd-numbered swinging claw member Rbo, and the engagement can be smoothly taken over and maintained.

Next, the process of shifting down from the 2nd speed state to the 1st speed state in which the reduction ratio is increased by one step when the vehicle speed is being reduced will be described with reference to FIGS.
FIG. 18 shows a state immediately after the gear position is decelerated in the second speed state.
Due to the deceleration, the driving force from the rear wheel to the counter gear shaft 12 acts, and as shown in FIG. 18 (d), the engagement convex portion 31 of the second driven transmission gear n2 whose rotational speed is lowered is brought into an engageable state. A so-called engine brake is applied which engages with the engaging claw portion Rp of the reverse rotation even-numbered swing claw member Rbe and transmits the rotational power of the counter gear shaft 12 to the second driven transmission gear n2.

In this state, in order to shift down to the first speed, the shift drum 67 is rotated by a predetermined amount in the opposite direction by manual operation of the shift select lever, and the control rod 51 is moved to the left in the axial direction. The eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, and Cbe try to move to the left in the axial direction via the coil springs 52s and 53s of the mechanisms 52 and 53. In the step cam rod Cbe, the reverse rotation even-stage swinging claw member Rbe that operates via the pin member 23 engages with the engagement convex portion 31 of the second driven transmission gear n2, and power is supplied from the second driven transmission gear n2. Therefore, there is a considerable frictional resistance for releasing the engagement by swinging the reverse-rotation even-numbered swing claw member Rbe, and reverse when the pin member 23 starts to rise on the inclined side surface of the cam groove v2. The cam rod Cbe for rotating even stages Is locked, it will remain unable to disengage (FIG. 19 (b), the reference (d)).
The reverse rotation even-numbered cam rod Cbe and the forward rotation odd-numbered cam rod Cao are also stopped through the spring holder 53h of the lost motion mechanism 53.

  On the other hand, the positive rotation even-numbered cam rod Cae is not very resistant because the positive-rotation even-numbered swinging claw member Rae operating via the pin member 23 is not engaged with the engagement convex portion 31 of the second driven transmission gear n2. Instead, the pin member 23 that has entered the cam groove v2 is pulled out and protrudes, and the forward rotation even-numbered swing claw member Rae is swung to retract the engagement claw portion Rp inward ( (Refer FIG.19 (d)).

In the first driven transmission gear n1, the reverse rotation odd-numbered stage cam rod Cbo moves to the left without resistance, and the pin member 23 enters the cam groove v1 of the reverse rotation odd-numbered stage cam rod Cbo (see FIG. 19A). ), The reverse rotation odd-numbered swinging claw member Rbo is swung by the urging force of the compression spring 22 and the centrifugal force of the engaging claw Rp to project the engaging claw Rp outward (see FIG. 19C). .
After the forward rotation even-stage swing claw member Rae retracts the engagement claw Rp inward, the reverse rotation odd-stage swing claw member Rbo projects the engagement claw Rp outward.

When the counter-rotating odd-numbered swinging claw member Rbo rotates together with the counter gear shaft 12 and catches up against the engaging convex portion 31 of the first driven transmission gear n1, it is shown in FIGS. 19 (c) and 19 (d). As shown, the engagement convex portion 31 of the second driven transmission gear n2 and the engagement convex portion 31 of the first driven transmission gear n1 are respectively connected to the engagement claw portion Rp of the reverse rotation even-numbered swing claw member Rbe and the reverse rotation odd number. There is a moment when the stepping claw member Rbo simultaneously contacts the engaging claw Rp.
Immediately after this, the engagement with the first driven transmission gear n1 rotating at a lower speed becomes effective, the engagement with the second driven transmission gear n2 is released, and the downshift from the second speed to the first speed is executed. The

  Disengagement between the engagement convex portion 31 of the second driven transmission gear n2 and the reverse rotation even-numbered cam rod Cbe eliminates the frictional resistance that fixes the reverse rotation even-numbered swing claw member Rbe, and the lost motion. The reverse rotation even-numbered cam rod Cbe urged by the coil spring 53s of the mechanism 53 moves backward to the left, and the pin member 23 that has entered the cam groove v2 comes out (see FIG. 20B). Then, the reverse rotation even-stage swinging claw member Rbe is swung and the engaging claw portion Rp is retracted inward (see FIG. 20D).

The reverse rotation even stage cam rod Cbe moves through the spring holder 53h of the lost motion mechanism 53, and the forward rotation odd stage cam rod Cao also moves, and the pin member 23 enters the cam groove v1 of the forward rotation odd stage cam rod Cao. Then, the positive rotation odd-numbered swinging claw member Rao swings and the engaging claw Rp protrudes outward to complete the shift (see FIG. 20 (c)).
In this state, the shifting operation from the second speed to the first speed is completed.

  As described above, when shifting down from the second speed state to the first speed state in which the reduction gear ratio is one step larger, as shown in FIG. 19, the engagement convex portion 31 of the second driven transmission gear n2 has an even number of reverse rotation steps. In a state where the engaging claw Rp of the moving claw member Rbe is in contact and engaged, the reverse rotation odd-numbered swinging claw member Rbo of the reverse rotation odd-numbered swing claw member Rbo is engaged with the engaging convex portion 31 of the first driven transmission gear n1 rotating at a lower speed. Since the engagement claw portion Rp catches up and switches the engagement, the engagement projection 31 of the second driven transmission gear n2 and the engagement claw portion Rp of the reverse rotation even-numbered swing claw member Rbe are smoothly engaged. Therefore, it is possible to perform a smooth downshift by smoothly operating without requiring a force for releasing the engagement.

  Similarly, for each downshift from 6th to 5th, 5th to 4th, 4th to 3rd, 3rd to 2nd, with the driven transmission gear n engaged with the swinging claw member R, Since the swinging claw member R is engaged with the driven transmission gear n having a large reduction ratio by one step and the shift down is performed, no force is required for releasing the engagement, and the clutch is smoothly operated and does not require a shifting clutch. In addition, there is no loss in switching time at the time of downshifting, there is no loss of driving force, and the shift shock is small, so that smooth downshifting can be performed.

For example, when in the second speed state, as shown in FIG. 18 (d), the reverse rotation even-numbered-step swing claw member Rbe is engaged with the engagement convex portion 31 of the second driven transmission gear n2, The engaging claw portion Rp of the other positive rotation even-numbered swinging claw member Rae is in an engageable state close to the engaging convex portion 31.
Therefore, when the vehicle speed is accelerated and a driving force is applied from the internal combustion engine to the second driven transmission gear n2, and the direction of the driving force is changed, the engagement convex portion 31 of the second driven transmission gear n2 is reversely rotated evenly. The engagement is quickly switched from the claw member Rbe to the forward rotation even-stage swing claw member Rae, and the engagement can be smoothly taken over and maintained.

In the multi-stage transmission 10, during acceleration by driving the internal combustion engine, even if the control rod 51 is moved to the left in the axial direction in order to shift down, the multi-stage transmission 10 and the driven transmission gear n that transmits power as it is are not changed. Since the engaged state with the moving claw member R cannot be released, when shifting down during acceleration, the speed change operation is performed with the friction clutch 5 temporarily disconnected and decelerated before the speed change operation. The driven transmission gear n having a large one-stage reduction ratio and the swinging claw member R are smoothly switched to engagement, and then the friction clutch 5 is engaged to accelerate.

  If the friction clutch 5 is not employed, the rotational speed of the driven transmission gear n is temporarily reduced by drive source rotational speed reduction means such as ignition timing control or fuel injection amount control, thereby shifting down even during acceleration. Can be executed smoothly.

When the driving force is applied from the rear wheel to the counter gear shaft 12 by decelerating the vehicle speed, shifting is not possible even if the control rod 51 is moved to the right in the axial direction in order to shift up. Since a shift shock is generated when the driven transmission gear n having a small reduction ratio is engaged with the swinging claw member R, it is possible to prevent a shift shock from occurring by prohibiting a shift-up operation during deceleration. Can do.

  By moving the cam rod C fitted in the cam guide groove 12g formed in the hollow inner peripheral surface of the counter gear shaft 12 in the axial direction, the pin member 23 fitted in the required portion of the counter gear shaft 12 is advanced and retracted. Since the swinging claw member R is swung to engage and disengage from the engagement convex portion 31 of the driven transmission gear n, the required pin member 23 is moved forward and backward with a small amount of movement of the cam rod C. As shown in FIG. 1, it is possible to make a structure in which adjacent driven transmission gears n supported by the counter gear shaft 12 are brought close to each other, and the axial width of the multi-stage transmission 10 can be changed. Can be reduced.

  According to this multi-stage transmission 10, the lost motion mechanism 53 on the right side causes the positive rotation odd-numbered cam rod Cao and the reverse rotation even-numbered cam rod Cbe to interlock with the control rod 51, and the second lost motion mechanism operates in the forward rotation even number. Since the stage cam rod Cae and the reverse rotation odd stage cam rod Cbo are linked to the control rod 51, the four types of cam rods Cao, Cae, Cbo, and Cbe are connected to one control rod 51 by two lost motion mechanisms 52 and 53. It can be interlocked, and the number of parts can be reduced to simplify the structure.

  As described above, the lost motion mechanisms 52 and 53 of the multi-stage transmission 10 are provided on the control rod 51 in the axial direction, and the lost motion mechanisms 52 and 53 are linked to different cam rods C. It is possible to make two or more different movements of the plurality of cam rods C with respect to the movement of the control rod 51 so that the speed change can be made smoothly, and the lost motion mechanisms 52 and 53 are made symmetrical to reduce the manufacturing cost. Facilitates parts management during assembly.

  According to the multi-stage transmission 10, the lost motion mechanisms 52 and 53 are interposed between the outer peripheral surface of the control rod 51 and the inner surfaces of the plurality of cam rods C. The structure that overlaps the control rod 51, lost motion mechanisms 52, 53, and cam rod C in the radial direction avoids the expansion of the multi-stage transmission 10 in the axial direction, and the lost motion mechanisms 52, 53 are compactly accommodated in the hollow of the counter gear shaft 12. Thus, the multi-stage transmission 10 itself can be reduced in size.

  Lost motion mechanisms 52 and 53 are interposed between the outer peripheral surface of the control rod 51 and the inner surfaces of the plurality of cam rods C. The inner peripheral recesses 52ha and 53ha of the spring holders 52h and 53h and the outer peripheral recess 51a of the control rod 51 Since the coil springs 52s and 53s are interposed in the space formed by 51b, the lost motion mechanisms 52 and 53 having the same shape can be formed on the control rod 51, and the manufacturing cost can be reduced.

It is sectional drawing of the multistage transmission which concerns on one embodiment of this invention. It is sectional drawing (II-II sectional view taken on the line of FIG. 4, FIG. 5) which shows a counter gear shaft and the structure around it. It is another sectional view (III-III line sectional view of Drawing 4 and Drawing 5) which shows a counter gear shaft and the structure around it. FIG. 4 is a sectional view taken along line IV-IV in FIGS. 2 and 3. FIG. 5 is a cross-sectional view taken along line VV in FIGS. 2 and 3. It is a disassembled perspective view of a control rod and a lost motion mechanism. FIG. 5 is an exploded perspective view of a state in which a lost motion mechanism is assembled to a control rod and a cam rod and the like. It is a disassembled perspective view of a part of a counter gear shaft, a pin member, and a spring. FIG. 9 is a left side view of the counter gear shaft (a view taken along arrow IX in FIG. 8). It is a disassembled perspective view of a rocking claw member, a spindle pin, a pin member, and a spring. It is a perspective view which shows the state which assembled | attached a part of speed-change drive means and the engagement means to the control rod. FIG. 12 is a perspective view showing a state where one bearing collar member is externally mounted on the counter gear shaft in the state shown in FIG. 11. It is explanatory drawing which shows the 1st speed state at the time of a shift up start. It is explanatory drawing which shows 1 process in the middle of a shift-up operation | work. It is explanatory drawing which shows the next process. It is explanatory drawing which shows the next process. It is explanatory drawing which shows the 2nd speed state at the time of completion of a shift up. It is explanatory drawing which shows the 2nd speed state at the time of downshift start. It is explanatory drawing which shows 1 process in the middle of a downshift work. It is explanatory drawing which shows the 1st speed state at the time of shift-down completion.

Explanation of symbols

m: drive transmission gear, m1 to m6 ... first to sixth drive transmission gears,
n: driven transmission gear, n1 to n6: first to sixth driven transmission gears,
1L ... Left engine case, 1R ... Right engine case, 2 ... Shift chamber, 4 ... Primary driven gear, 5 ... Friction clutch, 7L, 7R ... Bearing,
10 ... multi-speed transmission, 11 ... main gear shaft, 12 ... counter gear shaft, 12cv ... circumferential groove, 12av ... axial groove, 12p ... long rectangular recess, 12q ... short rectangular recess, 12g ... cam guide groove, 12h ... Pin hole, 12d ... Spring receiving part, 13 ... Bearing collar member,
20 ... engaging means, 22 ... compression spring, 23 ... pin member, 26 ... spindle pin, 31 ... engaging convex part,
C ... Cam rod, Cao ... Forward rotation odd-numbered cam rod, Cae ... Forward rotation even-numbered cam rod, Cbo ... Reverse rotation odd-numbered cam rod, Cbe ... Reverse rotation even-numbered cam rod, p ... Locking claw, v1, v2, v3, v4, v5, v6 ... cam groove,
R ... swinging claw member, Rao ... forward rotation odd-numbered swinging claw member, Rae ... forward rotation even-numbered swinging claw member, Rbo ... reverse rotation odd-numbered swinging claw member, Rbe ... reverse rotation even-numbered swinging claw member , Rp ... engaging claw, Rr ... pin receiving part, Rq ... wide end,
50 ... Transmission drive means, 51 ... Control rod, 51a ... Outer peripheral recess, 52, 53 ... Lost motion mechanism, 52h, 53h ... Spring holder, 52ha, 53ha ... Inner peripheral recess, 52s, 53s ... Coil spring, 55 ... Control rod 56, ball bearing, 57 ... nut, 58 ... shift pin, 59 ... engagement pin, 60 ... groove, 65 ... spindle, 66 ... bearing, 67 ... shift drum, 67v ... shift groove.

Claims (3)

A plurality of drive gears and driven gears are respectively supported by gear shafts that are parallel to each other in a constantly meshing state for each shift stage, and a plurality of gears of the drive gear and the driven gear are fixed to the gear shaft, In the multi-stage transmission that is provided between the gear and the gear shaft and that engages with each other and is switched and driven by the speed change drive means to perform speed change,
The engaging means includes
An engagement portion provided with an engagement surface in the circumferential direction at a plurality of locations in the circumferential direction of the inner peripheral surface of each gear;
An engaging member provided on the gear shaft and detachably engaged with the engaging portion of each gear;
A plurality of cam rods that are slidably contacted with the hollow inner peripheral surface of the gear shaft in the axial direction, a plurality of cam surfaces are formed on the slidable contact surface at required positions in the axial direction, and the engagement members are operated by movement;
The speed change driving means comprises:
A control rod provided on the hollow central shaft of the gear shaft inside the plurality of cam rods;
A lost motion mechanism that is interposed between an outer peripheral surface of the control rod and inner surfaces of the plurality of cam rods and that interlocks the control rod and each cam rod via a spring acting in an axial direction. Multi-stage transmission. Two lost motion mechanisms are provided in the axial direction on the control rod,
The multi-stage transmission according to claim 1, wherein each of the lost motion mechanisms interlocks the cam rods different from each other. The lost motion mechanism is
The control rod is interposed between the outer peripheral surface of the control rod and the inner surfaces of the plurality of cam rods at an axial position covering an outer peripheral recess formed by reducing the diameter of the control rod and is integrally locked with the required cam rod. A cylindrical spring holder formed with an inner peripheral recess having the same axial length corresponding to the outer peripheral recess;
A pair of opposing spring receivers straddling both spaces of the inner circumferential recess of the spring holder corresponding to the outer circumferential recess of the control rod;
The multi-stage transmission according to claim 1 or 2, comprising the spring interposed between the pair of spring receivers and biasing the spring receivers in a direction of separating the spring receivers.

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