JP5238550B2 - Arrangement structure of gear shifting actuator for motorcycle internal combustion engine - Google Patents

Description

  The present invention relates to an arrangement structure of a shift actuator that shifts and drives a transmission attached to an internal combustion engine mounted on a motorcycle.

An internal combustion engine mounted on a motorcycle generally includes a transmission integrally with an engine case, and a space for mounting the internal combustion engine on a vehicle body frame is narrow, and accessories are disposed around the internal combustion engine. The space becomes more and more narrow, and the gear shifting actuator for driving the gear to change gears must be arranged so as not to interfere with the accessories.
The speed change actuator is a relatively large actuator and is usually provided in a protruding manner on the engine case.

  There is an example in which an internal combustion engine mounted on a motorcycle has a transmission integrally with an engine case (crankcase), and a shift actuator for shifting and driving the transmission is provided on the engine case (for example, , See Patent Document 1).

JP 2008-137417 A

  In Patent Document 1, an electric motor, which is a speed change actuator, protrudes from the lower left side so as not to interfere with auxiliary equipment of an engine case that is integrally provided with a transmission.

The speed change actuator disclosed in Patent Document 1 is provided so as to protrude from the lower left side of the engine case. Therefore, the actuator does not have to have a special structure, but it protrudes sideways and is not preferable in appearance.
In addition, a protective member or the like must be specially provided in order to protect the speed change actuator from collision of foreign matters such as flying stones.

  The present invention has been made in view of the above points, and the object of the present invention is to project the shifting actuator to the outside while providing the shifting actuator outside the engine case of the internal combustion engine without interfering with the auxiliary machinery. The present invention is to provide an arrangement structure of a shifting actuator for a motorcycle-equipped internal combustion engine that can protect against collision of foreign matter without causing damage and maintain a good appearance.

In order to achieve the above object, the invention according to claim 1
In the arrangement structure of the speed change actuator (80) for driving to change the speed of the transmission (10) in the speed change chamber (2) of the internal combustion engine equipped with a motorcycle integrally provided with the speed change chamber (2) in the engine case (1). ,
The transmission (10) is supported by a main shaft (11) and a counter shaft (12) parallel to each other in a state in which a plurality of driving gears (m) and a driven gear (n) are always meshed at each shift stage, A drive gear (m) is fixed to the main shaft (11), and a plurality of cam rods (C) disposed in the hollow of the counter shaft (12) move in the axial direction with the counter shaft (12). An engagement means (20) for switching the engagement of the driven gear (n) for each gear, and a speed change drive mechanism (50) for moving the cam rod (C) to change speed,
The transmission drive mechanism (50)
A shift rod (51) that is inserted into the hollow central shaft of the counter shaft (12) inside the plurality of cam rods (C) and moves the cam rod (C) by moving in the axial direction;
A cylindrical shift rod operator (55) attached coaxially and rotatably to the end of the shift rod (51);
A shift pin (58) provided projecting radially in the shift rod operator (55);
A shift drum (67) having an outer peripheral surface formed with a shift guide groove (G) with which an end of the shift pin (58) engages,
On the outer wall of the engine case (1) in the rear direction of the vehicle body of the transmission (10), the engine case outer wall (1Ll, 1Lr (8)) facing each other on both the left and right sides is left, and the space between them is recessed forward. A recess (1D) that can accommodate the speed change actuator (80) is formed,
Of the engine case outer walls (1Ll, 1Lr (8)) opposed to the left and right sides, one of the engine case outer walls (1Lr (8)) is connected to the drive actuator (80d) by the shift actuator (80). It is mounted so as to protrude to the one engine case outer wall (1Lr (8)) side, and the shift drum (67) has a rotation center axis in the left-right direction between the countershaft and the speed change actuator (80) An intermediate shaft (70) that is rotatably supported in a direction and that transmits the rotation of the drive shaft (80d) of the speed change actuator (80) to the shift drum (67) through meshing of a gear is in the left-right direction. Thus, the arrangement structure of the shifting actuator of the motorcycle-equipped internal combustion engine that is axially supported is obtained.

  According to a third aspect of the present invention, in the arrangement structure of the shift actuator of the motorcycle-equipped internal combustion engine according to the first or second aspect, the main shaft, the counter shaft, and the shift actuator of the transmission are separated from each other. Are arranged at the vertices of a triangle with substantially equal.

According to the arrangement structure of the shifting actuator of the motorcycle-equipped internal combustion engine according to claim 1, the actuator main body of the shifting actuator is disposed in the recessed portion in which a part of the outer wall of the engine case is recessed inward. While providing a gear shifting actuator on the outside without interfering with auxiliary machinery, it protects the gear shifting actuator from collisions of foreign objects without requiring a special protective member, and it has an appearance without protruding the gear shifting actuator to the outside. Can keep good.
Further, since the actuator main body is disposed outside the engine case, a general-purpose actuator can be used without making the actuator a special structure.

The speed change actuator is arranged in a recess recessed inside by leaving the engine case outer wall facing each other at the center of the outer wall of the engine case in the vehicle body width direction, so that most of the speed change actuator is hidden in the recess. It is possible to improve the appearance and reduce the air resistance.
Since the shift drum is disposed between the counter shaft and the speed change actuator, the shift drum can be disposed centrally close to the main shaft, and the transmission and the internal combustion engine can be miniaturized with a more compact arrangement structure. it can.

  According to the arrangement structure of the shift actuator of the motorcycle-equipped internal combustion engine according to claim 3, the main shaft, the counter shaft, and the shift actuator of the transmission are arranged at the apex of a triangle whose distances are substantially equal. The transmission and the internal combustion engine can be downsized with a compact arrangement structure.

1 is a right side view of a partially omitted internal combustion engine incorporating a multi-stage transmission according to an embodiment of the present invention. It is sectional drawing (II-II sectional view taken on the line of FIG. 1) of a multistage transmission. It is a right view of an engine case It is a right view of a bearing lid member. It is a left view of a mounting bracket. It is explanatory drawing for demonstrating the attachment method of the motor for transmission. It is an expanded view of the outer peripheral surface of a shift drum. It is a figure which shows the correspondence of the rotation angle of a shift drum, each gear stage, and the detection angle of a potentiometer. It is sectional drawing (the IX-IX sectional view taken on the line of FIG. 11, FIG. 12) which shows a counter gear shaft and its surrounding structure. FIG. 13 is another cross-sectional view (cross-sectional view taken along the line XX in FIGS. 11 and 12) showing the counter gear shaft and the structure around the counter gear shaft. It is the XI-XI sectional view taken on the line of FIG. It is the XII-XII sectional view taken on the line of FIG. 9, FIG. It is a disassembled perspective view of a shift rod and a lost motion mechanism. It is a disassembled perspective view of the state which assembled | attached the lost motion mechanism to the shift rod, and a cam rod. It is a disassembled perspective view of a part of a counter gear shaft, a pin member, and a spring. FIG. 16 is a left side view of the counter gear shaft (a view taken along arrow XVI in FIG. 15). 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 mechanism and the engagement means to the counter gear shaft. It is a perspective view which shows the state which coat | covered the 1 bearing collar member on the counter gear shaft of the state shown in FIG. 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.

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 right side view of the internal combustion engine E with a part omitted, and FIG. 2 is a cross-sectional view of the multi-stage transmission 10 (cross-sectional view taken along the line II-II in FIG. 1), as shown in FIGS. In addition, the multi-stage transmission 10 is provided in an engine case 1 common to the internal combustion engine.

As shown in FIG. 3, which is a right side view of the engine case 1, the engine case 1 is formed by combining the upper engine case 1 </ b> U and the lower engine case 1 </ b> L that are vertically divided with respect to the crankshaft 6 that is oriented in the horizontal direction. The engine case 1 is integrally formed with a transmission chamber 2, and the main gear shaft 11 and the counter gear shaft 12 of the multi-stage transmission 10 are oriented in the horizontal direction in parallel to each other in the transmission chamber 2. Thus, it is pivotally supported.
The upper engine case 1U and the lower engine case 1L are united and supported so as to sandwich the crankshaft 6 and the countershaft 12 at the same height as the crankshaft 6 at a high position in the transmission chamber 2 from above and below.

  A transmission chamber 2 is formed in the rear half of the combined engine case 1, and the engine case 1 pivotally supports the left side portion of the main gear shaft 11 and the counter gear shaft 12 in the transmission chamber 2, but the right side of the transmission case is wide open. An opening 2h is formed, and the bearing cover member 8 covers the transmission chamber opening 2h. The bearing cover member 8 pivotally supports the right side portions of the main gear shaft 11 and the counter gear shaft 12.

The main gear shaft 11 is rotatably supported by the side wall of the lower engine case 1L and the bearing lid member 8 via bearings 3L and 3R, and passes through the right bearing 3R and protrudes from the transmission chamber 2 to the right end portion. A multi-plate friction clutch 5 is provided.
On the left side of the friction clutch 5, a primary driven gear 4 to which the rotation of the crankshaft 6 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.

Referring to FIG. 2, the main gear shaft 11 has a hollow cylindrical shape, and the inside of the hollow is composed of a long large-diameter hole portion 11a having a relatively large inner diameter and a small-diameter hole portion 11b slightly reduced in diameter on the right side. A long push rod 15l is inserted into the large-diameter hole 11a, a short push rod 15s is slidably inserted into the small-diameter hole 11b, and a right end 15lr of the long push rod 15l is fitted into the small-diameter hole 11b. Three balls 16 are sandwiched between the left end of the short push rod 15s.
The ball 16 has an outer diameter in which three small diameter holes 11b enter the same position in the axial direction, and the right end portion 15lr of the long push rod 15l and the left end portion of the short push rod 15s have an annular shape on the opposite end surfaces. A shallow annular groove is formed on each of the three balls 16 so that the three balls 16 can be stably held.

The left end portion of the long push rod 15l passes through the lower engine case 1L to the left and is fitted to the piston 17p of the clutch hydraulic actuator 17.
On the other hand, the right end portion of the short push rod 15s protrudes rightward from the main gear shaft 11 and abuts against the central portion of the pressure plate 5p of the friction clutch 5.

Therefore, when the clutch hydraulic actuator 17 is actuated and the piston 17p pushes the long push rod 15l to the right, the short push rod 15s is pushed through the ball 16, and the pressure plate 5p is made elastic by the clutch spring 5s. Accordingly, the engagement of the friction clutch 5 engaged by the elastic force of the clutch spring 5s can be released by moving the pressure plate 5p to the right.
The three balls 16 serve as thrust bearings and do not transmit the rotation of the short push rod 15s to the long push rod 15l.

Since the main gear shaft 11 has a large diameter hole portion 11a having a relatively large inner diameter, the weight can be reduced.
Also, when the three balls 16 interposed between the long push rod 15l and the short push rod 15s are inserted into the small diameter hole 11b, the three balls 16 are inserted into the large diameter hole 11a from the left side. When the long push rod 15l is inserted from the left, the three balls 16 are pushed to the right by the right end 15lr of the long push rod 15l and enter the small diameter hole 11b. Is pressed against the end face of the left end portion of the short push rod 15s that has been inserted.
Then, the three balls 16 are sandwiched between the right end portion 15lr of the long push rod 15l and the left end portion 15sl of the short push rod 15s, and are naturally spread in the circumferential direction so as to be stably accommodated in the annular grooves on both end surfaces. Since it is supported, assembly work is also easy.

The counter gear shaft 12 is pivotally supported via a bearing 7L sandwiched between both side walls of the upper engine case 1U and the lower engine case 1L, and the right end portion of the counter gear shaft 12 is supported by a bearing lid member 8 via a bearing 7R. It is pivotally supported.
The counter gear shaft 12 is a drive shaft, and an output sprocket 32 is attached to a shaft end portion protruding leftward from the bearing 7L.
A chain 38 is wound around the output sprocket 32, power is transmitted to the rear wheel side via the chain 38, and the vehicle travels.

The shaft end portion of the counter gear shaft 12 is formed with a male screw 12e at the outermost end, a spline groove 12s is formed inside (right side) of the male screw 12e, and an outer peripheral groove 12f is formed at the boundary between the male screw 12e and the spline groove 12s. (See FIG. 9).
Referring to FIG. 6, an annular collar member 33 is mounted on the shaft end portion of the counter gear shaft 12 so as to contact the inner race of the bearing 7L, and then the disc spring 34 mounted on the shaft end portion is connected to the spline groove 12s. The output sprocket 32 that is spline-fitted to the collar member 33 is then sandwiched between the collar member 33, and then the half cotter 35 is fitted to the outer peripheral groove 12f, and the annular retainer 36 is externally fitted to the half cotter 35.

The annular retainer 36 is composed of an outer peripheral wall and an annular side wall facing the outer peripheral surface and the outer surface of the half cotter 35. When the annular side wall abuts on the outer surface of the half cotter 35, the outer peripheral wall is the outer periphery of the half cotter 35. It protrudes inward (right side) from the half cotter 35 along the surface and comes into contact with the output sprocket 32 that is spline-fitted in the spline groove 12s.
Then, a bag-like nut member 37 is screwed into the outermost male screw 12e of the counter gear shaft 12, and the annular retainer 36 is sandwiched between the half cotter 35 and fixed.

  The output sprocket 32 that is spline-fitted to the counter gear shaft 12 in this way is regulated between the collar member 33 that is in contact with the inner race of the bearing 7L and the annular retainer 36 that is fixed in contact with the half cotter 35. Since the disc spring 34 is elastically pressed against the annular retainer 36, the force component that swings in the axial direction applied to the output sprocket 32 is absorbed by the disc spring 34, and the output sprocket 32 is always within the required axial range. The power can be stably transmitted to the chain 38 by being positioned.

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.
The third, fourth, fifth, and sixth drive transmission gears m3, m4, m5, and m6 are light weight with an inner circumferential groove mv formed in the circumferential direction on the inner circumferential surface where the spline fitting portion is formed. It is planned.

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 so as to be movable in the axial direction.

  A shift rod 51, which is one component of a speed change drive mechanism 50 that drives the cam rod C to change the speed, is inserted into the hollow center shaft of the counter gear shaft 12, and the movement of the shift 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 shift rod 51 in the axial direction is provided on the right side of the engine case .
The movement of the shift rod 51 in the axial direction is linked to 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. 13, the shift rod 51 of the speed change drive mechanism 50 has a cylindrical rod shape, and outer peripheral recesses 51a and 51b formed by reducing the diameter in two places on the left and right in the axial direction have a predetermined length. Is formed.
The right end of the shift 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 to correspond to the left and right outer peripheral recesses 51a and 51b of the shift 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 the shift rod 51 is slidably inserted and is configured by connecting the long holder 52hl and the short holder 52hs, and the inner peripheral surface corresponds to the outer peripheral recess 51a of the shift rod 51. An inner peripheral recess 52ha is formed.

  When the shift 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 shift rod 51 constitute a common space. To do.

A pair of left and right cotters 52c, 52c, which are spring receivers, are fitted to face each other 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 shift rod 51, and shift between the both cotters 52c, 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 shift rod 51 is the inner diameter, and is divided in half for assembly. 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 shift rod 51. The
Therefore, when the shift 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 shift rod 51. , Cbe, Cbe) are in contact with each other at the radiation position (see FIG. 14).

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. It has the latching claw p latched to (refer FIG. 14).

  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-numbered cam rod Cbe has a locking claw p that locks to the right spring holder 53h on the inner peripheral side surface (see FIG. 14).

  Accordingly, when the shift rod 51 is moved in the axial direction, the positive rotation odd-numbered cam rod Cao and the reverse-rotation even-numbered cam rod Cbe are interlocked 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. 14, a cylindrical shift rod operating element 55 is attached to the right end portion on the right side of the nut portion 51c of the shift rod 51 via a ball bearing 56 fitted inside the shift rod operation element 55.

  Two ball bearings 56 are connected in the axial direction. The ball bearing 56 is inserted into the right end portion on the right side of the nut portion 51c of the shift rod 51 and is 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 shift rod operator 55 holds the right end portion of the shift rod 51 rotatably.
A pin hole 55h pierced in the diametrical direction is formed in a cylindrical portion extending to the right side from the nut 57 to which the shift rod operating element 55 is screwed, and the shift pin 58 passes through the pin hole 55h.

The shift pin 58 passes through the shift rod operating element 55 and protrudes only to one side (see FIG. 2). As shown in FIG. 14, the protruding end portion is formed in a shift guide groove G of the shift drum 67 described later. A cylindrical engaging portion 58a that is slidably engaged, and a sliding portion 58b having a rectangular parallelepiped shape is formed between the small diameter cylindrical portion 58c penetrating the shift rod operating element 55 and the engaging portion 58a. Yes.
The portion that penetrates the shift rod operating element 55 is a small-diameter cylindrical part 58c having a smaller diameter than the engaging part 58a, so that the shift rod operating element 55 and the part that guides the shift rod operating element 55 are reduced in size and weight to save space. Can be planned.

  The lower engine case 1L is formed with a recess 1D for accommodating a speed change motor 80, which is a speed change actuator, with the left and right central portions of the rear lower part of the outer wall of the speed change chamber 2 recessed inside (front side) leaving both sides. A first fitting hole 1p is formed in the right engine case outer wall 1Lr of the opposing engine case outer walls 1Ll and 1Lr on both sides of the recess 1D to fit the outer periphery of the mounting bracket 81 of the speed change motor 80. .

The transmission chamber opening 2h on the right side of the transmission chamber 2 and the first fitting hole 1p are opened facing the inner side of the common annular frame wall 1f (see FIG. 3), and the bearing covers the transmission chamber opening 2h. The lid member 8 is attached so as to cover the annular frame wall 1f and simultaneously covers the first fitting hole 1p together with the transmission chamber opening 2h.
In addition, since the bearing lid member 8 abuts the peripheral edge portion against the end face of the annular frame wall 1f and fastens with the bolt 9, it can be attached and detached by removing the bolt 9.

As shown in FIG. 4, the bearing lid member 8 is fitted with a main bearing hole 8m for fitting a bearing 3R for supporting the main gear shaft 11 and a bearing 7R for supporting the counter gear shaft 12 obliquely above. A counter bearing hole 8n is formed, and a cylindrical guide portion 8g is formed so as to protrude rightward coaxially with the counter bearing hole 8n.
The cylindrical guide portion 8g includes a circular hole 8gh that is coaxial with the counter bearing hole 8n and has a small diameter, and a lower portion thereof is cut obliquely downward to form a guide long hole 8gl that is elongated in the axial direction.

Then, referring to FIG. 4, a shaft hole 8a for implanting a support shaft 65 (see FIG. 2) for pivotally supporting a shift drum 67, which will be described later, through a bearing 66 in a diagonally downward direction where the guide long hole 8gl is opened. A bearing hole 8b for supporting the intermediate shaft 70 via a bearing 70b (see FIG. 2) is formed below the shaft hole 8a. Further, a drive shaft 80d ( A second fitting hole 8q formed in a cylindrical shape coaxial with that of FIG. 2 is formed.
Three bolt holes 8c are formed on concentric circles around the second fitting hole 8q.

A support shaft 65 is previously planted in the shaft hole 8 a in the bearing lid member 8, and a cylindrical shift drum 67 is rotatably supported on the support shaft 65 via a bearing 66.
An intermediate shaft 70 is pivotally supported in the bearing hole 8b via a bearing 70b. A large-diameter intermediate gear 71 is fitted on the intermediate shaft 70, and a small-diameter intermediate gear 72 is integrally formed. The small-diameter gear 72 is meshed with a drum gear 67g formed on the side edge of the shift drum 67.

  When the bearing cover member 8 in this state is attached so as to cover the transmission chamber opening 2h and the first fitting hole 1p and cover the annular frame wall 1f, the main gear shaft 11 is inserted into the main gear shaft 11 via the bearing 3R. The counter gear shaft 12 is supported by the counter bearing hole 8n via the bearing 7R, and the shift rod operating element 55 at the right end of the shift rod 51 protruding rightward from the counter gear shaft 12 is cylindrical. The guide portion 8g is slidably inserted into the circular hole 8gh (see FIG. 2).

  Then, a rectangular parallelepiped sliding portion 58b of the shift pin 58 penetrating the shift rod operating element 55 is slidably inserted into the guide long hole 8gl of the cylindrical guide portion 8g, and the engaging portion 58a at the end of the shift pin 58 is inserted. Is slidably engaged with the shift guide groove G of the shift drum 67.

  The shift rod moving mechanism (shift drum 67, shift pin 58, shift rod operating element 55) that moves the shift rod 51 in the axial direction via the shift pin 58 by the rotation of the shift drum 67 is a friction at the right end of the main gear shaft 11. It is compactly arranged between the clutch 5 and the driven transmission gear n on the counter gear shaft 12 (see FIG. 2).

Since the guide long hole 8gl of the cylindrical guide portion 8g slides and guides the sliding portion 58b continuous with the engaging portion 58a of the shift pin 58 engaged with the shift guide groove G of the shift drum 67, the shift pin 58 Since the frictional resistance caused by the movement is the sliding part 58b in the vicinity of the engaging part 58a to which the operating force is applied by the rotation of the shift drum 67, the shift pin 58 has a structure that hardly tilts in the axial direction with the movement. Thus, it is possible to prevent the tilting and realize a smooth movement in the axial direction so that the speed change can be performed smoothly.
Further, the prevention of the tilt of the shift pin 58 prevents the shaft center of the shift rod operator 55 from being shaken, and the smooth movement of the shift rod 51 can be maintained and the shift can be performed more smoothly.
In addition, preventing the tilting of the shift rod 51 by guiding the shift rod operating element 55 with the cylindrical guide portion 8g also contributes to the smooth operation of the shift rod 51.

  Since the diameter of the small diameter cylindrical portion 58c on the shift rod operating element 55 side of the shift pin 58 is made smaller than the diameter of the portion on the shift drum 67 side, the strength of the engaging portion 58a to which the operating force is applied by the rotation of the shift drum 67 is maintained. However, by reducing the diameter of the shift pin 58 on the shift drum 67 side, the shift rod operating element 55 and the cylindrical guide portion 8g can be reduced in size and weight, and space can be saved.

The shift guide groove G of the shift drum 67 is formed so as to form a spiral over two or more rounds on the outer peripheral surface of the drum, and each speed change from the first speed to the sixth speed at every predetermined rotation angle (for example, 150 degrees) therebetween. The step positions are formed in order.
There is a neutral N position before the first gear.
FIG. 7 is a development view of the outer peripheral surface of the shift drum 67, and FIG. 8 shows the rotational angle of the shift drum 67 and the positional relationship between the respective shift stages.

  The shift guide groove G is provided with a shift stage groove portion Gs oriented in the circumferential direction in which the shift pin 58 is not moved in the axial direction by the rotation of the shift drum 67 at the axial position determined for each shift stage. A spiral transmission groove Gm that moves the shift pin 58 in the axial direction by rotation is sequentially connected.

  The shift guide groove G is formed over two or more rounds despite the fact that the outer diameter of the shift drum 67 is relatively small, so there is room for setting the length of each gear stage groove portion Gs to be long. As shown in FIG. 8, each shift step groove portion Gs has a length of 90 degrees in terms of the rotation angle of the shift drum 67, and each shift step groove portion Gs is provided with the shift drum 67 from the time when the drive of the shift motor 80 is stopped. It is set longer than the distance to run idle.

Even if the shift motor 80 rotates the shift drum 67 at a high speed, it can be easily set to a desired shift stage.
In other words, the shift rod can be stably maintained in a desired fixed position in a short time and the gear position can be set reliably and promptly even if the gear change speed of the gear change motor 80 is high with a simple configuration without requiring an intermittent drive mechanism.
The speed change groove portion Gm in the speed change process is set to 60 degrees as the rotation angle of the shift drum 67.

  Since the shift guide groove G is continuously formed on the outer peripheral surface of the shift drum 67 over two or more rounds, even in the multi-stage transmission 10 having as many as six shift stages, one shift drum 67 and the outer The shift drum 67 having a small diameter can be used, and the multi-stage transmission 10 can be reduced in size and weight, and the cost can be reduced.

An intermediate shaft 70 that integrally supports a small-diameter intermediate gear 72 that meshes with a drum gear 67g on the side edge of the shift drum 67 extends rightward and has a small-diameter gear 73 formed at the end thereof. As shown by a two-dot chain line, a large-diameter reduction gear 75b rotatably supported by a support shaft 74 implanted in the bearing lid member 8 meshes with a small-diameter gear 73 of the intermediate shaft 70, and has a large diameter. A small-diameter reduction gear 75 s integrated with the reduction gear 75 b is further engaged with a large-diameter gear 77 that is rotatably supported by a support shaft 76 that is implanted in the bearing lid member 8.
A cylindrical base 77a of the large-diameter gear 77 is connected to an operating portion of a potentiometer 78 supported by the lower engine case 1L.

Therefore, the rotation of the potentiometer 78 is decelerated via the reduction gear mechanism of the large diameter reduction gear 75b and the small diameter reduction gear 75s and detected by the potentiometer 78.
FIG. 8 shows the angle detected by the potentiometer 78 in correspondence with the rotation angle of the shift drum 67.

Since the potentiometer 78 detects the rotation of the shift drum 67 by decelerating with a reduction gear mechanism, as shown in FIG. 8, the detection angle is about one third of the rotation angle of the shift drum 67. Yes.
Thus, the inexpensive potentiometer 78 can be used by detecting the rotational angle of the shift drum 67 by decelerating it through the reduction gear mechanism.

The speed change motor 80 for rotating the shift drum 67 is disposed in the recess 1D on the outer wall of the lower engine case 1L.
A drive shaft 80d protrudes from one end face of a cylindrical motor body 80a, and an end of the motor body 80a from which the drive shaft 80d protrudes is a mounting bracket 81.

  As shown in FIG. 5, the mounting bracket 81 has a generally disk shape, and a bearing cylindrical portion 81s for supporting the drive shaft 80d of the speed change motor 80 via a bearing 82 is formed at the center (see FIG. 6). An annular mounting surface 81a of the speed change motor 80 is formed around the periphery, three motor body mounting holes 81b are formed around the outer periphery, and three motor mounting bolt boss portions 81c are formed.

  Referring to FIG. 6, drive shaft 80d protruding from motor body 80a of speed change motor 80 is fitted into bearing cylindrical portion 81s of mounting bracket 81 via bearing 82, and the motor is mounted on mounting seat 81a of motor body mounting hole 81b. The end of the main body case is abutted and the bolt 83 is screwed into the motor main body mounting hole 81b so that the mounting bracket 81 is attached to the motor main body case.

  The outer diameter of the disc-shaped mounting bracket 81 is substantially equal to the inner diameter of the first fitting hole 1p of the right engine case outer wall 1Lr that forms the right side surface of the recess 1D of the lower engine case 1L. The outer diameter of the cylindrical portion 81s is substantially equal to the inner diameter of the second fitting hole 8q of the bearing lid member 8.

  Referring to FIG. 6, seal member 84 is externally fitted to the outer peripheral groove formed in the outer peripheral groove formed on the outer peripheral surface of disc-shaped mounting bracket 81 attached to transmission motor 80, and mounting bracket 81 is recessed. By fitting into the first fitting hole 1p of the right engine case outer wall 1Lr from the 1D side (left side) and simultaneously fitting the bearing cylindrical portion 81s into the second fitting hole 8q of the bearing lid member 8, The motor 80 is disposed in the recess 1D of the lower engine case 1L, and the fastening bolts 86 are passed through the three bolt holes 8c of the bearing lid member 8 from the right side and screwed to the three motor mounting bolt boss portions 81c of the mounting bracket 81. Thus, the speed change motor 80 is attached.

Thus, when the speed change motor 80 is liquid-tightly fitted to the first fitting hole 1p and the second fitting hole 8q via the mounting bracket 81 and attached to the right engine case outer wall 1Lr and the bearing lid member 8. The motor body 80a of the speed change motor 80 is positioned in the recess 1D, and the drive gear 80g at the end of the drive shaft 80d protruding rightward from the motor body 80a is engaged with the large-diameter gear 71 of the intermediate shaft 70.
The fitting accuracy of fitting the mounting bracket 81 into the second fitting hole 8q of the bearing cylindrical portion 81s is higher than fitting the fitting bracket 81 into the first fitting hole 1p.

On the concave surface of the concave portion 1D of the lower engine case 1L, a semicircular ridge portion 90 is formed in a semicircular shape near the left engine case outer wall 1Ll that forms the left side surface of the concave portion 1D. A rubber member 91 is attached to the inner peripheral surface, and a motor main body 80a of a speed change motor 80 attached via a mounting bracket 81 is fitted to the semicircular protrusion 90 via the rubber member 91.
A semicircular semicircular support member 92 facing the semicircular ridge 90 is fitted to the motor body 80a via a rubber member 93 adhered to the inner peripheral surface, and both ends are fastened by bolts 95. Thus, the motor body 80a is supported by the semicircular protrusion 90 and the semicircular support member 92 so as to be tightened.

Further, a drop-off prevention screw rod 96 is screwed into the left engine case outer wall 1Ll forming the left side surface of the recess 1D so as to be movable back and forth coaxially with the drive shaft 80d of the attached transmission motor 80 from the left side.
As shown in FIG. 2, the shifting motor 80 is prevented from falling off when the tip of the falling prevention screw rod 96 comes close to the rear surface (left side) of the motor body 80a by the advancement of the falling prevention screw rod 96. .

  When mounting the speed change motor 80, the drop prevention screw rod 96 is retracted and the semicircular support member 92 is removed, and the speed change motor 80 is moved from the rear where the recess 1D of the lower engine case 1L opens. As shown in FIG. 6, a part of the outer peripheral surface of the mounting bracket 81 attached to the speed change motor 80 is brought into contact with the opening edge of the first fitting hole 1p of the right engine case outer wall 1Lr. The mounting bracket 81 is fitted into the first fitting hole 1p so as to turn the speed change motor 80 about the contact point, and at the same time, the mounting bracket 81 is fitted into the second fitting hole 8q of the bearing lid member 8. The bearing cylindrical portion 81s is fitted.

Since the fitting accuracy of the outer periphery of the mounting bracket 81 to the first fitting hole 1p is not required to be as high as the second fitting hole 8q, the fitting of the mounting bracket 81 is performed smoothly, and the speed change motor 80 Easy installation work.
Since the mounting bracket 81 is liquid-tightly fitted into the first fitting hole 1p and the second fitting hole 8q, high sealing performance is ensured.

The mounting bracket 81 is fixed to the bearing lid member 8 with fastening bolts 86.
Then, as the drop prevention screw rod 96 advances, the tip of the drop prevention screw rod 96 comes close to the end surface of the motor main body 80a to prevent the transmission motor 80 from falling off and is fitted to the semicircular protrusion 90. A semicircular support member 92 is fitted into the motor main body 80a and fastened to the semicircular protrusion 90 with bolts 95 to support the motor main body 80a.

When the speed change motor 80 accommodates the motor body 80a in the recess 1D of the lower engine case 1L and is attached to the lower engine case 1L, the drive gear 80g of the drive shaft 80d of the speed change motor 80 is larger than the intermediate shaft 70. Engaged with the diameter gear 71.

A speed change motor 80 disposed in a recess 1D formed obliquely below and rearward of the outer wall of the speed change chamber 2 of the lower engine case 1L is located below the counter gear shaft 12 in the speed change chamber 2 and is connected to the main gear shaft. Located behind 11.
That is, referring to FIG. 1, counter gear shaft 12 is disposed obliquely above main gear shaft 11, and transmission motor 80 is disposed below counter gear shaft 12. The driven shift drum 67 is arranged between the transmission motor 80 and the counter gear shaft 12, and the shift drum 67 and the transmission motor 80 arranged below the counter gear shaft 12 are connected to the counter gear shaft. The main gear shaft 11 arranged obliquely in front of 12 can be arranged intensively close to the main gear shaft 11, and the multi-stage transmission 10 and the internal combustion engine E can be downsized with a compact arrangement structure.

The speed change drive mechanism 50 is configured as described above, and when the speed change motor 80 is driven, the drive shaft 80d rotates via the large diameter gear 71 of the intermediate shaft 70 and the reduction gear mechanism of the small diameter gear 72. This is transmitted to the rotation of the shift drum 67, and the shift drum 67 is sequentially rotated to the gear position.
As described above, the shift stage groove portion Gs of the shift guide groove G of the shift drum 67 is set to be longer than the distance that the shift drum 67 runs idle from the time when the drive of the shift motor 80 is stopped. And it can be set quickly.

  The rotation of the shift drum 67 is guided by the shift pin 58 having the engagement portion 58a engaged with the shift guide groove G in the guide long hole 8gl of the cylindrical guide portion 8g of the bearing cover member 8, and is translated in the axial direction. The shift rod 51 is moved in the axial direction via the shift rod operator 55, and the movement of the shift rod 51 is caused by the eight cam rods Cao, Cao, Cae, Cae of the engaging means 20 via the lost motion mechanisms 52, 53. , Cbo, Cbo, Cbe, Cbe.

The shift rod 51 to which the lost motion mechanisms 52 and 53 are assembled 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 shift 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. 16).
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. 15).

  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. 2, 9, and 10).

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. 9 and 10).
About half of the shift rod operating element 55 is inserted inside the enlarged inner diameter part on the right side.

  As described above, when the shift rod 51, the lost motion mechanisms 52, 53 and the eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe are incorporated into the hollow of the counter gear shaft 12, all of them are incorporated. When the shift rod 51 is moved together in the axial direction, the reverse rotation odd-numbered cam rod Cbo and the forward rotation even-numbered cam rod Cae are interlocked in the axial direction via the coil spring 52s of the left lost motion mechanism 52. The forward rotation odd stage cam rod Cao and the reverse rotation even stage cam rod Cbe are linked in the axial direction via the coil spring 53s of the right lost motion mechanism 53.

  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 shift 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 shift 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 is compactly placed 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 shift rod 51 in the axial direction, and each lost motion mechanism 52 and 53 interlocks with another cam rod C. Therefore, a plurality of lost motion mechanisms 52 and 53 are associated with the movement of one shift rod 51. 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, 53 are interposed between the outer peripheral surface of the shift rod 51 and the inner surfaces of the plurality of cam rods C. The inner peripheral recesses 52ha, 53ha of the spring holders 52h, 53h and the outer peripheral recess 51a of the shift 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 shift rod 51.

  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 a large thickness as shown in FIG. 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. 18 shows a state in which all the swinging claw members R are assembled in this manner.

  In the exploded perspective view of FIG. 17, it is embedded in the circumferential groove 12cv, the long rectangular recess 12p, and the short rectangular recess 12q corresponding to the odd-stage gears (first, third, and fifth driven transmission gears n1, n3, and n5). 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, the next bearing collar member 13 is covered so as to cover the other end of the support shaft pin 26, and the driven transmission gear n is incorporated. In the same manner, the incorporation of the next-stage engaging means 20 is sequentially repeated, and finally the leftmost bearing collar member 13 is packaged to finish.

As shown in FIG. 19, the bearing collar member 13 is packaged 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. 9 and 10).

The protrusions 30 on the inner peripheral surface of each driven transmission gear n are formed with six engaging convex portions 31 at equal intervals in the circumferential direction (see FIGS. 9, 10, 11, and 12).
The engaging convex portion 31 has a thin arc shape when viewed from the side (in the axial direction shown in FIGS. 11 and 12), and both end surfaces in the circumferential direction engage with the engaging claw portion Rp of the swinging 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 shift rod 51 to which the shift operation element 55 is attached, and eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe are provided around the outer periphery of the lost motion mechanisms 52, 53. , Cbe are disposed in the hollow of the counter gear shaft 12.

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 Rr 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 in this way, the counter gear shaft 12 is freely rotatable on the left and right bearings 7L and 7R fitted to the side wall of the engine case 1 and the bearing lid member 8. When the shaft is supported, the six driven transmission gears n and the seven bearing collar members 13 are alternately combined and sandwiched from the left and right to be 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 projecting from the moving positions of the cam rods C of the corresponding engaging means 20 so that the pin receiving portions Rr of the swinging claw member R can be seen 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 speed change drive mechanism 50, the shift drum 67 is rotated by a predetermined amount by driving the speed change motor 80, and the rotation of the shift drum 67 is axially moved through the shift pin 58 fitted in the shift guide groove G. The eight cam rods Cao, Cao, Cae, Cae, Cbo, Cbo, Cbe, Cbe of the engaging means 20 are interlocked via 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.

Here, the lubricating structure of the counter gear shaft 12 of the multi-stage transmission 10 will be described.
Referring to FIG. 6, a plurality of oil supply introduction holes 12 x that are penetrated in the radial direction are formed at positions where the collar member 33 of the counter gear shaft 12 is fitted, and the introduction holes 33 x are also formed in the collar member 33 correspondingly. An annular seal member 39 is formed around the outer periphery.

  Then, as shown in the left side view of the counter gear shaft 12 in FIG. 16, the hollow inner peripheral surface of the counter gear shaft 12 is provided with four cam guide grooves 12g every four places. An axial oil supply groove 12y is cut in parallel to the cam guide groove 12g at a radial position (equally spaced positions in the circumferential direction) (see FIGS. 11 and 12).

Each of the axial oil supply grooves 12y communicates with a radial oil supply hole 12z that is drilled in the radial direction at an axial position where the required pin member 23 exists, and the radial oil supply hole 12z is connected to the axial oil supply groove 12y and the swinging claw member. It communicates with the circumferential groove 12cv in which R is fitted.
In addition, each axial direction oil supply groove | channel 12y does not connect to the radial direction oil supply hole 12z drilled by the adjacent axial direction position among the axial direction positions in which the pin member 23 is located, but the radial direction of every other axial position It communicates with the oil supply hole 12z.

  That is, of the four axial oil supply grooves 12y, the two opposing axial oil supply grooves 12y correspond to odd-numbered gears (first, third, and fifth driven transmission gears n1, n3, and n5). It communicates with the radial oil supply hole 12z that opens in the circumferential groove 12cv where the pin member 23 is located (see FIG. 11), and the other two opposite axial oil supply grooves 12y are even gears (second and fourth gears). , The sixth driven transmission gear n2, n4, n6) communicates with the radial oil supply hole 12z opened in the circumferential groove 12cv where the pin member 23 is located (see FIG. 12).

  Since the lubricating oil introduced into the hollow end portion of the counter gear shaft 12 by the oil supply introduction hole 12x is guided in the axial direction along the inner peripheral surface of the hollow portion of the counter gear shaft 12, the axial oil supply groove 12y is guided in the axial direction. Even with small oil supply actuators by reducing the oil path resistance of oil, the entire oil supply is smoothly supplied to the entire engagement switching mechanism (engagement means 20 such as rocking claw member R, pin member 23, compression spring 22 and cam rod C). It can be sufficiently lubricated.

  Four axial oil supply grooves 12y are formed, and each axial oil supply groove 12y does not communicate with the radial oil supply holes 12z drilled at the adjacent axial position among the axial positions where the pin member 23 is located. Lubricating oil supplied from one end of the axial oil supply groove 12y can be passed to the other end without much lowering the hydraulic pressure, and can be supplied substantially evenly to the engagement switching mechanisms arranged in the axial direction.

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 during acceleration by driving the internal combustion engine will be described with reference to FIGS.
FIGS. 20 to 24 show sequential changes over time. In each figure, FIG. (A) is a cross-sectional view in which the gears and the like in FIG. 9 (cross-sectional view taken along the line IX-IX in FIGS. 11 and 12) are omitted. FIG. 5B is a cross-sectional view in which the gears and the like in FIG. 10 (the cross-sectional view taken along the line XX in FIGS. 11 and 12) are omitted, and 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. 20 shows the first speed state. In FIG. 20C, the first driven transmission gear n1 rotates in the arrow direction, and in FIG. 20D, 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. 20A). 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. 20C), the counter gear shaft 12 is rotated together with the first driven transmission gear n1 at the same rotational speed as that of the first driven transmission gear n1.
20 to 27, a lattice hatch is applied to the swinging claw member R and the engaging projection 31 which are transmitting 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. 20B), 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. 20A and 20B).

  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 shift rod 51 starts moving 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. 21A and 21C, one reverse rotation odd-numbered cam rod Cbo has a reverse rotation odd-numbered swinging claw member Rbo that operates via a pin member 23 and 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. 21 (a)), and the reverse rotation odd-numbered stage swinging claw The member Rbo is swung and the engaging claw Rp is retracted inward (see FIG. 21C).

  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-numbered cam rod 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. 21A and 21C). )reference).

In the state shown in FIG. 21, 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. 21B and 21D).
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 shift rod 51 further moves to the right and reaches the 2nd speed position, the reverse-rotation odd-numbered cam rod Cbo and the forward-rotation even-numbered cam rod Cae further to the right. 22 (b), 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 has 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. 22D).
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. 23D).
At this moment, referring to FIG. 23 (c) and FIG. 23 (d), 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. 24D), and the first driven transmission gear 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. 24C).

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. 24D).
Thus, the shifting operation from the first speed to the second speed is completed, and the state shown in FIG. 24 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 one step smaller, as shown in FIG. 23, the engagement 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. 20 (c), at the same time that the positive rotation odd-numbered swinging 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 one step larger when the vehicle speed is being reduced will be described with reference to FIGS.
FIG. 25 shows a state immediately after the shift stage is in the second speed state and is decelerated.
Due to the deceleration, the driving force from the rear wheel to the counter gear shaft 12 acts, and as shown in FIG. 25 (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 shift 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 the even rotation stage is stopped. Te will remain unable to disengage (FIG. 26 (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.26 (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. 26A). ), The reverse rotation odd-stage 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. 26C). .
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.

Then, when the counter-rotating odd-numbered swinging claw member Rbo rotates together with the counter gear shaft 12 and catches up with the engaging convex portion 31 of the first driven transmission gear n1, it is shown in FIGS. 26 (c) and 26 (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 and moves to the left, and the pin member 23 that has entered the cam groove v2 comes out (see FIG. 27B). Then, the counter-rotating even-numbered swinging claw member Rbe is swung and the engaging claw portion Rp is retracted inward (see FIG. 27D).

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-stage swinging claw member Rao swings and the engaging claw portion Rp protrudes outward to complete the shift (see FIG. 27C).
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. 26, the engagement convex portion 31 of the second driven transmission gear n2 has the reverse rotation even number step. 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. 25 (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, when accelerating by driving the internal combustion engine, even if the shift rod 51 is moved leftward in the axial direction so as 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 shift 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.

The speed change motor 80 of the motorcycle-equipped internal combustion engine E is disposed in the recess 1D between the engine case outer walls 1Ll and 1Lr facing both sides of the engine case 1 without interfering with the auxiliary machinery. Most of the 80 can be concealed in the recess 1D, the appearance can be kept good, the air resistance can be reduced, and the speed change motor 80 can be protected from the collision of foreign matter without requiring a special protective member. Can do.
Further, since the motor main body 80a is arranged outside the engine case 1, a general-purpose motor can be used without making the speed change motor 80 a special structure.

  A counter gear shaft 12 is disposed obliquely above the main gear shaft 11, a transmission motor 80 is disposed below the counter gear shaft 12, and a shift drum 67 driven by the transmission motor 80 is provided with the transmission motor 80 and the counter. The main gear shaft 11, the counter gear shaft 12, and the speed change motor 80 are arranged between the gear shaft 12 and the apex of the triangle where the distance between them is substantially equal, and the shift drum 67 is brought closer to the main gear shaft 11. Therefore, it is possible to reduce the size of the transmission and the internal combustion engine.

E ... Internal combustion engine, 1 ... Engine case, 1U ... Upper engine case, 1L ... Lower engine case, 1D ... Recess, 1Ll ... Left engine case outer wall, 1Lr ... Right engine case outer wall, 1p ... First fitting hole DESCRIPTION OF SYMBOLS 2 ... Shift chamber, 4 ... Primary driven gear, 5 ... Friction clutch, 6 ... Crankshaft, 7L, 7R ... Bearing, 8 ... Bearing cover member, 8m ... Main bearing hole, 8n ... Counter bearing hole, 8g ... Cylindrical shape Guide part, 8gl ... guide slot, 8q ... second fitting hole,
10 ... multi-speed transmission, 11 ... main gear shaft, 12 ... counter gear shaft, 12a ... center cylindrical portion, 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, 12x ... Oil supply introduction hole, 12y ... Axial oil supply groove, 12z ... Radial oil supply hole, 13 ... Bearing collar member, 15l ... Long push rod, 15s … Short push rod, 16… ball, 17… clutch hydraulic actuator,
20 ... engaging means, 22 ... compression spring, 23 ... pin member, 26 ... spindle pin, 30 ... protrusion, 31 ... engaging convex part, 32 ... output sprocket, 33 ... collar member, 34 ... disc spring, 35 ... half cotter, 36 ... annular retainer, 37 ... nut member, 38 ... chain, 39 ... annular seal member,
50 ... transmission drive mechanism, 51 ... shift rod, 51a, 51b ... outer peripheral recess, 52, 53 ... lost motion mechanism, 52h, 53h ... spring holder, 52ha, 53ha ... inner peripheral recess, 52s, 53s ... coil spring, 55 ... Shift rod operator, 56 ... ball bearing, 57 ... nut, 58 ... shift pin, 60 ... groove, 65 ... support shaft, 66 ... bearing, 67 ... shift drum, G ... shift guide groove, Gs ... shifting step groove, Gm ... shifting groove, 67g ... drum gear, 70 ... intermediate shaft, 71 ... large diameter intermediate gear, 72 ... small diameter intermediate gear,
73 ... small diameter gear, 74 ... support shaft, 75b ... large diameter reduction gear, 75s ... small diameter reduction gear, 76 ... support shaft, 77 ... large diameter gear, 78 ... potentiometer,
80 ... Motor for shifting, 80a ... Motor body, 81 ... Mounting bracket, 82 ... Bearing, 83 ... Bolt, 84,85 ... Seal member,
90 ... Semicircle protrusion, 91 ... Rubber member, 92 ... Semicircle support member, 93 ... Rubber member, 94 ..., 95 ... Bolt, 96 ... Screw rod for preventing falling off,
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,
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.

Claims (3)

In the arrangement structure of the speed change actuator (80) for driving to change the speed of the transmission (10) in the speed change chamber (2) of the internal combustion engine equipped with a motorcycle integrally provided with the speed change chamber (2) in the engine case (1). ,
The transmission (10) is supported by a main shaft (11) and a counter shaft (12) parallel to each other in a state in which a plurality of driving gears (m) and a driven gear (n) are always meshed at each shift stage, A drive gear (m) is fixed to the main shaft (11), and a plurality of cam rods (C) disposed in the hollow of the counter shaft (12) move in the axial direction with the counter shaft (12). An engagement means (20) for switching the engagement of the driven gear (n) for each gear, and a speed change drive mechanism (50) for moving the cam rod (C) to change speed,
The transmission drive mechanism (50)
A shift rod (51) that is inserted into the hollow central shaft of the counter shaft (12) inside the plurality of cam rods (C) and moves the cam rod (C) by moving in the axial direction;
A cylindrical shift rod operator (55) attached coaxially and rotatably to the end of the shift rod (51);
A shift pin (58) provided projecting radially in the shift rod operator (55);
A shift drum (67) having an outer peripheral surface formed with a shift guide groove (G) with which an end of the shift pin (58) engages,
On the outer wall of the engine case (1) in the rear direction of the vehicle body of the transmission (10), the engine case outer wall (1Ll, 1Lr (8)) facing each other on both the left and right sides is left, and the space between them is recessed forward. A recess (1D) that can accommodate the speed change actuator (80) is formed,
Of the engine case outer walls (1Ll, 1Lr (8)) opposed to the left and right sides, one of the engine case outer walls (1Lr (8)) is connected to the drive actuator (80d) by the shift actuator (80). The shift drum (67) is rotatably supported with the rotation center axis directed in the left-right direction, and is mounted so as to protrude toward the outer wall (1Lr (8)) of one engine case. An internal combustion engine mounted on a motorcycle, wherein an intermediate shaft (70) for transmitting the rotation of the drive shaft (80d) of (80) to the shift drum (67) through meshing of a gear is supported in the left-right direction. Arrangement structure of engine speed change actuator. The one engine case outer wall (1Lr (8)) is an annular frame wall (1f) integral with the engine case (1) and a separate bearing lid member (8) that closes the opening of the annular frame wall (1f). And consist of
The automatic transmission according to claim 1, wherein the shift actuator (80) is supported by the bearing lid member (8), and the shift drum (67) and the intermediate shaft (70) are pivotally supported. Arrangement structure of speed change actuator of internal combustion engine mounted on motorcycle.   The main shaft (11), the counter shaft (12), and the shift actuator (80) of the transmission (10) are arranged at the vertices of a triangle having mutually equal distances. 3. An arrangement structure of a shift actuator for an internal combustion engine mounted with a motorcycle according to claim 1.

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