JP4554234B2 - Gearbox for internal combustion engine - Google Patents

Description

  The present invention relates to a transmission for an internal combustion engine mounted on a motorcycle.

  FIG. 11 is a cross-sectional view of a conventional transmission that is integrated with an internal combustion engine for a motorcycle. An input shaft 021 and an output shaft 022 of the transmission are provided below the crankshaft (not shown) in parallel with the crankshaft. The input shaft 021 is rotatably supported by the left crankcase 001 and the right crankcase 002 via bearings. The output shaft 022 is rotatably supported by a left crankcase cover 003 and a right crankcase 002 via bearings. The input shaft 021 is driven by a crankshaft through a primary reduction gear and a clutch. A wheel (not shown) is directly attached to the left end of the output shaft 022.

  The input shaft 021 is provided with four drive gears m1 to m4 in order of diameter, and all are fixed to the input shaft. These are the first-speed drive gear to the fourth-speed drive gear. Four driven gears c1 to c4 that are always meshed with the four gears m1 to m4 of the input shaft are loosely fitted to the output shaft 022 so as to be freely rotatable with respect to the output shaft 022. These are the 1st-speed driven gear to the 4th-speed driven gear.

  A central hole 030 having one end opened is formed at the center of the large diameter portion 022a of the output shaft 022 into which the gears c1 to c4 are loosely fitted. Four axial slits 032 communicating the hole 030 and the outer peripheral portion of the thick cylindrical portion 031 are cut at equal intervals in the circumferential direction. The central hole 030 and the four slits 032 form a cross-section slit.

  The central through-holes of the gears c1 to c4 fitted to the large-diameter portion 022a of the output shaft 022 are all formed in the same uneven shape. A plurality of inward projections k1 to k4 are engaging portions 033 with which a cruciform pole 036, which will be described later, is engaged, and each inner end thereof is in contact with the outer periphery of the output shaft large-diameter portion 022a in the circumferential direction. The sliding part 033a slides. A portion kn having no engaging portion is a neutral position of the cross-shaped pole 036. The concave portion sandwiched between the adjacent engaging portions 033 is a pole tip moving space 034 serving as a space for moving the tip of a cruciform pole described later in the axial direction.

  The cross-section slit formed by the center hole 030 and the axial slit 032 includes a pole connecting shaft 035 and a cross-shaped pole (pawl, gear rotation locking claw) 036 attached to the tip of the pole connecting shaft 035 so that it can slide in the axial direction. It is mounted (for example, see Patent Document 1). A guide pipe 037 is mounted in a space between the pole connecting shaft 035 and the center hole 030. The guide pipe 037 slides in the axial direction together with the pole connecting shaft 035 and the cross-shaped pole 036. The driver moves the pole connecting shaft 035 via a rotation linear motion converter 050 described later, and the tip of the cross-shaped pole 036 attached to the tip of the pole connecting shaft 035 is set to any one of the gears c1 to c4. When the gears are engaged with the engaging portions 033 and the free rotation of the gears with respect to the output shaft 022 is locked, the gears are selected. As a result, a speed change is made according to the gear ratio between the gear locked to the output shaft 022 and the fixed gear on the input shaft 021 side meshed therewith, and the rotation of the crankshaft passes through the input shaft 021 to the output shaft 022. The wheel is driven. An uneven portion 056 is formed on a part of the outer periphery of the guide pipe 037. A steel ball 057 is urged and pressed by the coil spring 058 from the large diameter portion 022a to the uneven portion 056. This is a device that urges the cross-shaped pole 036 so as to be in the normal position of each gear position.

  A rotating linear motion conversion device 050 is shown at the right end of FIG. This device is provided between the right crankcase 002 and the rotating linear motion conversion device cover 051. There is a central shaft 052 that is rotatably supported by the cover at the center of the rotational linear motion conversion device cover 051. An arm member 053 is fixed to the central shaft 052, and an engagement piece 054 that contacts and slides on the pole connecting shaft 035 is rotatably attached to the tip of the arm member 053 via a support shaft 055. is there. A pulley 080 is fixed to the central shaft 052, and an up-side wire 071 and a down-side wire 072 are attached to the pulley 080 along the circumference of the circular groove, and one end of each wire is fixed to the pulley 080. Has been. The other ends of the up-side wire 071 and the down-side wire 072 are connected to a turning operation unit (not shown) attached to the vehicle handle.

  In the above apparatus, when shifting from the first gear to the top gear (fourth gear in this example), it is necessary to largely rotate the rotation operation unit attached to the handle of the vehicle.

Japanese Patent Publication No. 5-70747.

  In a conventional transmission, if a shift from the first gear to the top gear is to be performed, it is necessary to rotate the rotation operation unit attached to the steering wheel of the vehicle at a large angle. Was putting an unreasonable burden on his fingers. In order to prevent an excessive burden on the finger of the vehicle driver, for example, when performing a four-stage shift from a first speed gear to a fifth speed gear, the present invention provides a small step for performing the one-stage shift. Provided is a means that enables shifting from the first gear to the fifth gear by repeating the angle rotation operation four times.

The present invention solves the above-mentioned problems, and the invention according to claim 1 provides an input shaft and an output shaft parallel to the input shaft, and a plurality of gears constituting different gear ratios on the two shafts. A gear group provided on one of the input shaft and the output shaft is fixed to the shaft, and the gear group provided on the other shaft is rotatably fitted to the shaft. A pivot coupling provided on a vehicle handle, comprising a pole coupling shaft having a pole that moves in the axial direction and selectively locks one of the gears fitted on the other shaft. In the internal combustion engine speed change device that converts the rotation of the part into a linear motion and performs a shift via the rotation linear motion conversion means for moving the pole connecting shaft and the pole in the axial direction, the rotation linear motion conversion means is a shift plate mounted pivotally central axis around the center axis, said sheet A return spring for returning the center plate to the neutral position, an arm member having a distal end coupled to the pole coupling shaft and a proximal end fixed to the central axis, a ratchet fixed around the central axis, Left and right pawl members that are rotatably supported by a support shaft at left and right positions of the ratchet on the shift plate and that are opposed to the ratchet so as to be engageable with each other, and one shift stage of the pawl provided on a vehicle handle A rotation operation unit capable of rotation corresponding to the movement of a minute, one end is connected to the rotation operation unit, and the other end is connected to the left and right claw members, respectively, to operate the rotation operation unit. Accordingly, the wire includes a wire for rotating the claw member, and the wire engages the claw of the claw member connected to the wire with the ratchet only when a tension is applied to the wire by the operation of the rotation operation unit. Together While by rotating the arm member with the ratchet causes a force of the wire to the ratchet, internal combustion engine, characterized by being configured to move the pawl connecting shaft and the pawl in the axial direction It is a transmission device .

According to a second aspect of the present invention, in the transmission of the internal combustion engine according to the first aspect, the claw member is supported by the shift plate via a return spring that urges the claw so as not to contact the ratchet. The claw member is engaged with the ratchet against the force of the return spring when a tension is applied to the wire.
According to a third aspect of the present invention, in the transmission for an internal combustion engine according to the first or second aspect, the base end of the arm member extends in a fan shape, and an uneven portion is formed around the base end. Further, the ball urged by the spring is pressed.

  According to the present invention, a multi-stage shift can be achieved by repeating a small-angle rotation operation a plurality of times at a rotation operation unit attached to a vehicle handle.

  FIG. 1 is a developed cross-sectional view including each rotation shaft of a four-stroke cycle internal combustion engine for a motorcycle according to an embodiment of the present invention, and is a view of the cross-section viewed from above in an in-vehicle state of the internal combustion engine. In the figure, the outer shell of the internal combustion engine is composed of a left crankcase 1, a right crankcase 2, a left crankcase cover 3, a right crankcase cover 4, a cylinder block 5, a cylinder head 6, and a cylinder head cover 7. The crankshaft 8 is composed of left and right parts, and is integrated by a crankpin 9. The crankshaft 8 is rotatably supported by the left crankcase 1 and the right crankcase 2 via main bearings 10 and 11, respectively. A piston 13 is connected to the crankpin 9 via a connecting rod 12, and the piston 13 reciprocates in the cylinder axis direction in the cylinder block 5. A combustion chamber 14 is formed on the lower surface of the cylinder head 6. A spark plug 15 is attached to the cylinder head 6, and its tip faces the combustion chamber 14. A camshaft 16 of a valve mechanism is rotatably supported in the cylinder head 6.

  A cam chain chamber 17 penetrating from the left end space of the cam shaft 16 to the left end space of the crankshaft 8 is provided on the left side of the internal combustion engine assembled as described above. A drive sprocket 18 is fitted to the left side portion of the crankshaft 8, and a driven sprocket 19 is fixed to the left end portion of the camshaft 16, and a cam chain 20 is bridged between the two sprockets. As a result, the rotational driving force of the crankshaft 8 is transmitted to the camshaft 16, and the intake and exhaust valves arranged in the cylinder head 6 can be driven at a predetermined timing by the cam formed on the camshaft 16.

  An ACG (alternating current generator) 40 is provided at the right end of the crankshaft 8. The ACG 40 includes a stator 41 fixed to the right crankcase 2 and a rotor 42 fixed to the crankshaft 8 and rotating on the outer periphery of the stator as the crankshaft 8 rotates. A centrifugal fan 43 is fixed to the right side surface of the rotor 42 and rotates together with the rotor 42. The air flow that flows in from a large number of small air intake holes 44 provided in the right crankcase cover 4 and is wound up by the centrifugal fan 43 circulates inside the right crankcase cover 4, and serves as a cylinder block 5 and a cylinder head. 6 is cooled.

  An input shaft 21 and an output shaft 22 of the transmission are provided below the crankshaft. The input shaft 21 is rotatably supported by the left crankcase 1 and the right crankcase 2 via bearings. The output shaft 22 is rotatably supported by the left crankcase cover 3 and the right crankcase 2 via bearings. A primary reduction drive gear 23 is fixed to the left end portion of the crankshaft 8, and a primary reduction driven gear 24 meshing with the drive gear 23 is rotatably provided at the left end portion of the input shaft 21. The primary reduction driven gear 24 is connected to the clutch outer 26 of the clutch 25. A clutch inner 27 of the clutch 25 is fixed to the input shaft 21. The output shaft 22 is an output shaft of the internal combustion engine, and a wheel 28 is directly attached to the left end of the output shaft 22.

  The input shaft 21 is provided with five drive gears M1 to M5 in the order of diameter, and all are fixed to the input shaft 21. These are the first-speed drive gear to the fifth-speed drive gear. Five driven gears C1 to C5 that are always meshed with the five gears M1 to M5 of the input shaft 21 are loosely fitted to the output shaft 22 so as to be freely rotatable. These are the 1st-speed driven gear to the 5th-speed driven gear.

  FIG. 2 is an enlarged cross-sectional view of the large-diameter portion 22a of the output shaft 22 in which the gears C1 to C5 are loosely fitted. A central hole 30 having one end opened at the center is formed, and four axial directions communicating the central hole 30 and the outer peripheral portion of the thick cylindrical portion 31 are formed in the surrounding thick cylindrical portion 31. The slits 32 are cut at equal intervals in the circumferential direction. The center hole 30 and the four slits 32 form a cross-section slit.

  FIG. 3 shows a cross section of the central portion of the gear C1 in the thickness direction as a representative example of the loosely fitted gears C1 to C5. The central through hole of the gear C1 is formed in an uneven shape. A plurality of inward projections are engaging portions 33 with which a cruciform pole, which will be described later, is engaged, and each of the inner ends thereof is in contact with the outer periphery of the output shaft large-diameter portion 22a and slides in the circumferential direction. It is the moving part 33a. The concave portion sandwiched between the adjacent engaging portions 33 is a pole tip moving space 34 serving as a space for moving the tip of the pole described later in the axial direction. The inner edge shape of the central through hole of the loosely fitting gears C2 to C5 is the same as the inner edge shape of the gear C1.

  The cross-section slit formed by the center hole 30 and the axial slit 32 has a pole connecting shaft 35 and a cross-shaped pole (pawl, gear rotation locking claw) 36 attached to the tip of the pole connecting shaft 35 so that it can slide in the axial direction. It is installed. The driver moves the pole connecting shaft 35 via a rotation linear motion converting device 50 described later, and the tip of the cross-shaped pole 36 attached to the tip of the pole connecting shaft 35 is set to any one of the gears C1 to C5. When engaged with the engaging portions 33 and the free rotation of the gear with respect to the output shaft 22 is stopped, the gear is fixed with respect to the output shaft 22, and the gear is selected. In this process, the gear Cx fixed to the output shaft 22 and the gear ratio between the fixed gear Mx meshing with the gear Cx in the fixed gears M1 to M5 on the input shaft 21 side are changed, and the crankshaft 8 Is transmitted to the output shaft 22 via the input shaft 21, and the wheel 28 is driven.

  FIG. 4 is a diagram of the gear groups C1 to C5 mounted on the large diameter portion 22a and the rotating linear motion conversion device 50 connected thereto. 5 is a cross-sectional view taken along the line VV in FIG. First, in the left half of FIG. 4, as described above, the five driven gears C1 to C5 are loosely fitted to the large diameter portion 22a of the output shaft 22. These are the 1st-speed driven gear to the 5th-speed driven gear, respectively. Engagement portions 33 of K1 to K5 are provided on the inner side of each gear corresponding to C1 to C5. The first speed driven gear C1 is provided with a neutral portion Kn where the engaging portion 33 does not exist. 4 and 5, a cross-section slit formed by a center hole 30 and an axial slit 32 is provided with a pole connecting shaft 35 and a cross-shaped pole 36 attached to the tip of the pole connecting shaft 35 so as to be slidable in the axial direction. Yes. A guide pipe 37 is mounted between the pole connecting shaft 35 and the inner surface of the center hole 30. The guide pipe 37 moves together with the pole connecting shaft 35 in the axial direction. The driver moves the pole connecting shaft 35 in the axial direction via the rotating linear motion conversion device 50, and the tip of the cross-shaped pole 36 is engaged with the engaging portion K1 of any one of the gears C1 to C5. When engaged with K5 and the free rotation of the gear with respect to the output shaft 22 is locked, a gear shift (1st to 5th) according to the gear ratio with the fixed gear on the input shaft 21 side engaged with the gear is achieved. Made. When the pole is at the position Kn, it is in a neutral state. FIG. 4 shows a neutral state.

  6 is a cross-sectional view of the rotational linear motion conversion device 50 shown in the right half of FIG. 4, and is a view mainly depicting a cross-section VI-VI of FIG. Some members show cross sections other than the VI-VI cross section in order to clearly show their shapes. This device is provided between the right crankcase 2 and the rotating linear motion conversion device cover 51.

  At the center of the rotating linear motion conversion device cover 51, there is a center shaft 52 that is rotatably supported by the cover. The arm member 53 is fixed to the central shaft 52 at the innermost side in FIG. 4 and at the right side in FIG. A ratchet 59 is fixed to the central shaft 52 at the foremost side in FIG. 4 and the left end in FIG. Therefore, when the ratchet 59 is rotated, the arm member 53 is rotated via the central shaft 52. An engagement piece 54 that slides in contact with the pole connecting shaft 35 is rotatably attached to the tip of the arm member 53 via a support shaft 55. The lower part of the arm member 53 extends in a fan shape, and an uneven portion 56 is formed around the fan member. A steel ball 57 is urged and pressed by the coil spring 58 from the side of the rotational linear motion conversion device cover 51 to the uneven portion. This is a device that urges the cruciform pole 36 so as to be within a normal position of each gear position (a central position in the axial direction of the engaging portion 33 of each gear).

A shift plate 60 is rotatably mounted on the central shaft 52 behind the ratchet 59 in FIG. A large through-hole 61 is provided in the upper half of the shift plate 60, and a stopper boss 62 protruding from the rotating linear motion conversion device cover 51 on the rear side passes through the through-hole 61 and is in front of the shift plate 60. Protrudes to the side. The shift plate 60 has an engagement protrusion 63 formed by bending a part of the periphery of the through hole 61 toward the front side. Between the ratchet 59 and the shift plate 60, a return torsion coil spring 64 is mounted on the central shaft 52, and two legs respectively extending from both ends of the coil spring 64 are engaged with the stopper boss 62. The protrusion 63 is sandwiched.

  On the left and right of the lower part of the shift plate 60, a left claw member 65 and a right claw member 66 are rotatably attached by support shafts 67 and 68, respectively. Each claw member 65, 66 includes a claw 65a, 66a on the side facing the ratchet 59. The support shafts 67 and 68 are respectively provided with torsion coil springs 69 and 70 that are bridged between the shift plate 60 and the claw members 65 and 66, and the claws 65a and 66a are attached to the ratchet when not in operation. It is urged not to touch 59. One end of the up-side wire 71 is attached to the outer end of the left claw member 65, and one end of the down-side wire 72 is attached to the outer end of the right claw member 66, respectively. The other ends of the up-side wire 71 and the down-side wire 72 are connected to a turning operation unit attached to a vehicle handle.

  FIG. 4 shows a neutral state, where the cross pole 36 is in the neutral position Kn. Shifting is performed intermittently step by step. When the cruciform pole 36 reaches the position of the first speed engagement portion K1, the first speed state is established. FIG. 7 is an intermediate state from the neutral state to the first speed state, and FIG. 8 is a view showing the positions of the members of the rotating linear motion conversion device 50 when the first speed state is reached.

Next, a description will be given of the shifting process for one step for shifting from the neutral state to the first speed state.
(1) In the neutral state of FIG. 4, the driver pulls the up-side wire 71 by operating the turning operation portion of the steering wheel of the vehicle.
(2) Then, the left claw member 65 rotates against the urging force of the torsion coil spring 69, and the claw 65 a engages with the recess of the ratchet 59.
(3) When the up-side wire 71 is further pulled, the left claw member 65 moves upward, and the engaged ratchet 59 is rotated.
(4) Since the ratchet 59 is connected to the arm member 53 via the central shaft 52, the arm member 53 starts to rotate.
(5) The steel ball 58 pressed against the concave portion of the concave and convex portion 56 below the arm member 53 starts to ride on the convex portion of the concave and convex portion 56.
(6) Since the support shaft 67 of the left claw member 65 is erected on the shift plate 60, the shift plate 60 rotates together with the ratchet 59 and the arm member 53 by the same angle as the left claw member 65 moves upward. Move.
(7) With the rotation of the arm member 53, the pole connecting shaft 35, the cross-shaped pole 36, and the guide pipe 37 are moved in the axial direction by being pulled by the engaging piece 54 at the tip thereof.
(8) The steel ball 57 that has climbed the convex portion of the concave-convex portion 56 below the arm member 53 starts to descend after reaching the top and enters the adjacent concave portion.
(9) When the rotation of the shift plate 60 proceeds and one edge of the inner periphery of the through hole 61 contacts the stopper boss 62, the rotation of the shift plate 60 and the like stops, and the state shown in FIG. At this time, both legs of the return torsion coil spring 64 are spread to the maximum by the stopper boss 62 and the engaging protrusion 63.
(10) In this state, the cross-shaped pole 36 is engaged with the first gear engagement position K1 of the gear, but is slightly advanced from the first gear position K1. The steel ball 57 is also slightly advanced from the first speed position K1. In this state, the tension of the up-side wire 71 is released.
(11) When the tension of the up-side wire 71 is released, the engagement between the claw 65a of the left claw member 65 and the recess of the ratchet 59 is released by the biasing force of the torsion coil spring 69 applied to the left claw member 65. Is done.
(12) When the tension of the up-side wire 71 is further released, the shift plate 60 is moved by the action of the return torsion coil spring 64 that generates an elastic force between the stopper boss 62 and the engaging projection 63 of the shift plate 60. Then, the claw members 65, 66 and the like standing on this return to their original positions.
(13) At this time, since the engagement between the claw 65a of the claw member 65 and the recess of the ratchet 59 has already been released, the ratchet 59 and the arm member 53 are interlocked even if the claw member 65 returns to the original position. Without staying in the rotated position.
(14) Since the steel ball 57 is pressed against the innermost part of the concave portion corresponding to the first speed of the concave and convex portion 56 of the arm member 53, the arm member 53, the pole connecting shaft 35, the cross pole 36, and the guide pipe 37 are slightly Retreat to the normal position of the first gear. FIG. 8 shows the first speed state reached by the above-mentioned one-stage shift process.

  Although the speed increasing process for one step for shifting from the neutral state to the first speed state has been described above, the other speed increasing processes are the same. By repeating these one-stage accelerations a plurality of times, a high speed state such as a fifth speed state can be reached. In the deceleration process, the driver operates the turning operation part of the steering wheel of the vehicle and pulls the down-side wire 72 to similarly perform one-step deceleration. A characteristic of the transmission is that the arm member drive mechanism including the wires 71 and 72, the claw members 65 and 66, the shift plate 60, and the like returns to the original position every time one-stage shift is performed.

  FIG. 9 is a view showing the position of each member of the rotational linear motion conversion device 50 at the third speed, and FIG. 10 is a diagram showing the position of each member of the rotational linear motion conversion device 50 at the fifth speed. Since the position of each member of the rotational linear motion conversion device 50 in the first speed is shown in FIG. 8, the position of each member in the second speed and the fourth speed can be easily determined from the position of each member shown in these drawings. The illustration is omitted because it can be estimated. 9 and 10, the shift plate 60, the claw members 65, 66, etc. are in their original positions (positions when no speed change operation is performed) and are the same as the positions in FIGS. Simple display of only the outline. Since the return torsion coil spring 64 is also in its original position, it is not shown.

  As described above in detail, in the present embodiment, a multi-stage shift can be achieved by repeating a small-angle rotation operation a plurality of times by a rotation operation unit attached to a vehicle handle.

1 is a developed cross-sectional view including each rotation shaft of a four-stroke cycle internal combustion engine for a motorcycle according to an embodiment of the present invention. 4 is an enlarged cross-sectional view of a large diameter portion 22a of the output shaft 22. FIG. It is sectional drawing of the center part in the thickness direction of gear C1. It is a figure of gear group C1-C5 and the rotation linear motion conversion apparatus 50 connected to this, The neutral state is shown. It is VV sectional drawing of FIG. FIG. 5 is a cross-sectional view of the rotational linear motion conversion device 50 shown in the right half of FIG. 4, mainly depicting a VI-VI cross section of FIG. 4. It is the figure which showed the position of each member of the rotation linear motion conversion apparatus 50 in the intermediate state from a neutral state to a 1st speed state. It is a figure of the rotation linear motion conversion apparatus when the 1st speed state is reached. It is the figure which showed the position of each member of the rotation linear motion conversion apparatus 50 in 3rd speed. It is the figure which showed the position of each member of the rotation linear motion conversion apparatus 50 in 5th speed. It is sectional drawing of the conventional transmission.

Explanation of symbols

  M1, M2, M3, M4, M5... Driving gear, Mx... Driving gear meshing with the locked driven gear Cx, C1, C2, C3, C4, C5... Driven gear, Cx. Gears, Kn ... neutral pole positions, K1, K2, K3, K4, K5 ... 1st-5th pole positions, 1 ... left crankcase, 2 ... right crankcase, 3 ... left crankcase cover, 4 ... right crankcase cover, 5 ... cylinder block, 6 ... cylinder head, 7 ... cylinder head cover, 8 ... crankshaft, 9 ... crankpin, 10 ... main bearing, 11 ... main bearing, 12 ... connecting rod, 13 ... piston, 14 ... combustion chamber, 15 ... ignition plug, 16 ... cam shaft, 17 ... cam chain chamber, 18 ... drive sprocket, 19 ... driven sprocket, 20 ... cam chain, 21 ... input shaft of transmission, 22 ... output shaft, 22a ... Large diameter of output shaft , 23 ... primary reduction drive gear, 24 ... primary reduction driven gear, 25 ... clutch, 26 ... clutch outer, 27 ... clutch inner, 28 ... wheel, 30 ... center hole, 31 ... thick-walled cylindrical part, 32 ... Axial slit, 33 ... engagement part, 33a ... sliding part, 34 ... pole tip moving space, 35 ... pole connecting shaft, 36 ... cross pole, 37 ... guide pipe, 40 ... ACG (alternating current generator), 41 ... Stator, 42 ... Rotor, 43 ... Centrifugal fan, 44 ... Small hole for air intake, 50 ... Rotary linear motion converter, 51 ... Rotary linear motion converter cover, 52 ... Central shaft, 53 ... Arm member, 54 ... engagement piece, 55 ... support shaft, 56 ... uneven portion, 57 ... steel ball, 58 ... coil spring, 59 ... ratchet, 60 ... shift plate, 61 ... through hole, 62 ... stopper boss, 63 ... engagement protrusion, 64 ... Torsion coil spring for return, 65 ... Left claw member, 65a ... Claw, 66 ... Right claw member, 66a ... Claw, 67 ... Support shaft, 68 ... Support shaft, 69 ... Torsion Ile spring, 70 ... Torsion coil spring, 71 ... Up-side wire, 72 ... Down-side wire, m1, m2, m3, m4 ... Drive gear (conventional example), c1, c2, c3, c4 ... Driven gear (conventional example) , Kn ... neutral pole position (conventional example), k1, k2, k3, k4 ... 1st to 4th pole position (conventional example), 001 ... left crankcase, 002 ... right crankcase, 003 ... left crankcase Cover, 021 ... transmission input shaft, 022 ... output shaft, 022a ... large diameter portion of output shaft, 030 ... center hole, 031 ... thick cylindrical portion, 032 ... axial slit, 033 ... engagement portion, 033a ... Sliding part, 034 ... Pole tip moving space, 035 ... Pole connecting shaft, 036 ... Cross-shaped pole, 037 ... Guide pipe, 050 ... Rotating linear motion converter, 051 ... Rotating linear motion converter cover, 052 ... Central axis, 053 ... arm member, 054 ... engagement piece, 055 ... support shaft, 056 ... uneven portion, 057 ... steel ball, 058 ... coil , 071 ... up-side wire, 072 ... down-side wire, 080 ... pulley

Claims (3)

A plurality of gear sets (M1, C1, M2, C2, M3) provided with an input shaft (21) and an output shaft (22) in parallel with the input shaft (21, 22) and having different gear ratios on the two shafts (21, 22) , C3, M4, C4, M5, C5), the gear group provided on either the input shaft (21) or the output shaft (22) (21) is fixed to the shaft, and the other shaft (22 The gear group (C1, C2, C3, C4, C5) provided on the other shaft (22) is rotatably fitted to the shaft (22) and moves in the axial direction on the other shaft (22). A pole connecting shaft (35) having a pole (36) for selectively locking one of the gear groups (C1, C2, C3, C4, C5) fitted to the The rotation of the rotation operation portion provided is converted into a linear motion, and the speed is changed via the rotational linear motion converting means (50) for moving the pole connecting shaft (35) and the pole (36) in the axial direction. In a transmission for an internal combustion engine,
The rotating linear motion converting means (50)
A shift plate (60) mounted on the central shaft (52) so as to be rotatable about the central shaft (52);
A return spring (64) for returning the shift plate (60) to the neutral position;
An arm member (53) having a distal end coupled to the pole coupling shaft (35) and a proximal end fixed to the central shaft (52);
A ratchet (59) fixed around the central axis (52);
Claws (65a, 66a) rotatably supported by support shafts (67, 68) at the left and right positions of the ratchet (59) and opposed to the ratchet (59) to the shift plate (60). Left and right claw members (65, 66), and
A rotation operation unit provided on a handle of the vehicle and capable of rotating corresponding to the movement of the pawl (36) for one shift step;
One end is connected to the turning operation unit, and the other end is connected to the left and right claw members (65, 66), and the claw member (65, 66) is moved along with the operation of the turning operation unit. Rotating wires (71, 72),
With
The wire (71, 72) is a claw (65a, 66a) of the claw member (65, 66) connected to the wire (71, 72) only when tension is applied to it by the operation of the turning operation unit. Is engaged with the ratchet (59) to cause the force of the wire to act on the ratchet (59) and the arm member (53) is rotated together with the ratchet so that the pole connecting shaft (35) and the pole ( A transmission for an internal combustion engine, which is configured to move 36) in the axial direction . The claw member (65, 66) is supported by the shift plate (60) via a return spring (69, 70) that urges the claw (65a, 66a) so as not to contact the ratchet (59). The claw member (65, 66) engages with the ratchet (59) against the force of the return spring (69, 70) when a tension is applied to the wire (71, 72). A transmission for an internal combustion engine according to claim 1. The base end of the arm member (53) extends in a fan shape, and an uneven portion (56) is formed around the fan member, and the ball (57) urged by a spring (58) is pressed against the uneven portion (56). 3. The transmission device for an internal combustion engine according to claim 1, wherein the transmission device is an internal combustion engine.

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