JP2017032050A - Multistage transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multistage transmission which is excellent in a gear change characteristic by releasing gears from fastened states that the gear are fastened to a gear shaft into open states by a small forcible release force.SOLUTION: A multistage transmission has an input-side gear shaft to which a plurality of drive-side gears are idly attached, and switches a gear change stage by fastening the gears to the gear shaft. Oscillation arms 45 are attached into the gears so as to be oscillatory, and when tip faces 52a of the oscillation arms 45 are engaged with engagement faces 51a of the gears, the gears are fastened to the gear shaft. Inclination angles α of the engagement faces 51a are set so that gear face load angles θ which are formed of directions of gear face loads Fx applied from the oscillation arms 45 and directions of fasten loads F which are applied between oscillation centers of the oscillation arms 45 and the engagement faces 51a are located inside the oscillation arms 45, and that the gear face load angles θ satisfy a condition of θ>tan*μ.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a parallel shaft type multi-stage transmission having an input-side gear shaft provided with a plurality of drive gears and an output-side gear shaft provided with a plurality of driven gears that are always meshed with the drive gears.

  The parallel shaft type multi-stage transmission has an input side gear shaft and an output side gear shaft parallel thereto, and the input side gear shaft is provided with a plurality of drive side gears, and the output side gear shaft. The shaft is provided with a plurality of driven gears that are always meshed with the driving gear and constitute a transmission gear pair. One of the drive-side gear and the driven-side gear constituting the transmission gear pair is mounted on the gear shaft so as to freely rotate, and the other is fixed to the gear shaft. When the idler gear is connected to the gear shaft, a transmission gear pair that transmits power from the input gear shaft to the output gear shaft is selected from the plurality of transmission gear pairs.

  Patent Document 1 discloses a multi-stage transmission including a synchronous mesh clutch for connecting an idled gear to a gear shaft. The multi-stage transmission includes a first drive shaft in which a third gear, a fourth gear, and a fifth gear are idleably provided, and a second drive shaft in which a first and second gear are provided idle. The driven gears that always mesh with the respective drive gears are fixed to the output shaft. A synchronous mesh clutch is provided on the first drive shaft, and a two-way clutch is provided on the second drive shaft, and the idle gear is fastened to the drive shaft by these clutches.

  Patent Document 2 discloses a transmission including a dog clutch in order to fasten an idle gear to a gear shaft. This transmission has an output-side countershaft in which a plurality of driven gears are rotatably provided, and a speed-change rod provided with an annular protrusion is inserted into the shaft hole of the subshaft so as to be movable in the axial direction. ing. When a connector or engagement pin that meshes with the engagement groove of each driven gear is provided on the countershaft so as to be movable in the radial direction, and when the annular protrusion engages the connector with the engagement groove by the movement of the speed change rod, the driven The gear is connected to the countershaft.

  Patent Document 3 discloses a multi-stage transmission including a swinging claw member, that is, a swinging arm, for connecting an idled gear to a gear shaft. This multi-stage transmission has a counter gear shaft in which a plurality of driven gears, that is, driven transmission gears, are provided so as to freely rotate, and the swinging claw member is provided swingably on a support pin provided on the counter gear shaft. Yes. A control rod is inserted into the counter gear shaft so as to be movable in the axial direction, and a pin member is mounted so as to be movable in the radial direction, and swings by moving the control rod and projecting the pin member in the radial direction. When the claw member is engaged with the driven transmission gear, the driven transmission gear is connected to the counter gear shaft.

JP 2004-316825 A Japanese Patent Publication No. 58-44899 JP 2009-243655 A

  The tip of the swing claw member engages with the engagement surface of the engagement protrusion provided on the inner surface of the gear, and the angle formed by the engagement surface and the radial line of the control rod is reduced. Thus, when the engaging surface is brought close to the radial line, the swinging claw member can be prevented from being detached from the engaging convex portion of the gear. However, in order to release the engagement between the swinging claw member and the engaging projection and forcibly release the swinging claw member from the fastened state to the released state, a large forced release force is applied to the swinging claw member by the actuator. It is necessary to add, and it is necessary to increase the size of the actuator. On the other hand, when the angle formed by the engagement surface and the radial line is increased, it is necessary to apply a large fastening force to the swinging claw member in order to keep the swinging claw member in the fastening state.

  Therefore, when the gear is fastened, the swinging claw member, that is, the swinging arm reliably maintains the engaged state with the engagement surface, and when the gear is released, the engagement surface and the swinging claw member are released by a small forcible release force. Various studies have been conducted to achieve this. As a result, it has been found that the coefficient of friction between the swinging claw member and the engagement surface has a great influence on the forced release force in addition to the inclination angle of the engagement surface.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-stage transmission excellent in speed change characteristics so that a gear can be released from a fastening state in which a gear is fastened to a gear shaft to a released state by a small forcible releasing force.

The multi-stage transmission of the present invention is provided with an input-side gear shaft provided with a plurality of drive-side gears, and a plurality of driven-side gears that always mesh with the drive-side gears to form a transmission gear pair. An output-side gear shaft, one of the drive-side and driven-side gears forming a transmission gear pair is fixed to the gear shaft, and the other gear is idly mounted on the gear shaft, In a multi-stage transmission that switches the gear position by fastening the gear to the gear shaft, the gear is swingably mounted inside the idler gear and engages with an engagement surface provided on the idler gear. A swing arm provided with an engaging claw at a tip; a shift rod mounted in a hollow hole provided in the gear shaft so as to be reciprocally movable in an axial direction; and provided in the shift rod; The idler gear that presses the engaging claw against the engaging surface A fastening protrusion for fastening to the gear shaft; and a forcible release protrusion provided on the shift rod for pressing the base end of the swing arm when releasing the fastening of the gear. The tooth surface load angle θ formed by the direction of the tooth load applied from the swing arm in the vertical direction and the direction of the fastening load applied between the swing center of the swing arm and the engagement surface is the swing. When the friction coefficient between the tip surface of the swing arm and the engaging surface is μ inside the arm, the tooth surface load angle θ satisfies the condition of θ> tan ⁻¹ · μ, An inclination angle of the engagement surface is set.

  When the inclination angle of the engagement surface is set so that the tooth surface load angle θ satisfies the above-described conditions, the swing arm in the fastening state for fastening the gear to the gear shaft is swung to the release state for releasing the fastening. Since the forcible release force can be reduced, the speed change operation can be quickly performed, and the actuator for driving the swing arm can be reduced in size. As a result, a multi-stage transmission with excellent shift characteristics can be obtained.

It is a skeleton figure which shows the power transmission system provided with the multistage transmission which is one Embodiment. FIG. 2 is a cross-sectional view showing the multi-stage transmission shown in FIG. 1. It is an expanded sectional view which shows the principal part of FIG. FIG. 4 is a partially cutaway perspective view showing a gear shaft on the input side shown in FIG. 3. FIG. 5 is a sectional view taken along line 5-5 in FIG. FIG. 6 is a cross-sectional view illustrating a state in which the gear illustrated in FIG. 5 is fastened to the gear shaft by a swing arm. FIG. 6 is a friction force characteristic diagram showing a frictional force applied from the swing arm to the engagement surface in a state where the swing arm is engaged with the engagement surface of the gear. FIG. 5 is a partially cutaway perspective view showing a rod driving mechanism for driving the shift rod shown in FIGS. 3 and 4. It is a longitudinal cross-sectional view of FIG. (A1) is a perspective view showing the position of the fastening ball and the release ball relative to the gear shaft when the swing arm is released, (B1) is a development view showing the sleeve of the rod drive mechanism at that time, (A2) FIG. 5 is a perspective view showing positions of a fastening ball and a release ball with respect to the gear shaft when the swing arm is fastened, and (B2) is a development view showing the sleeve at that time. (A1) is a perspective view showing the position of the fastening ball of the swing arm in the released state and the release ball relative to the shift rod at the start of the skipping shift, and (B1) is a development view showing the sleeve at that time, (A2 ) Is a perspective view showing the positions of the fastening ball and the release ball with respect to the shift rod in a state where the shift rod is rotated by the axial movement of the sleeve, and (B2) is a development view showing the sleeve at that time, (A3) ) Is a perspective view showing the positions of the fastening ball and the release ball with respect to the shift rod in a state where the shift rod is moved in the axial direction by the sleeve, and (B3) is a development view showing the sleeve at that time. (A1) is a perspective view showing positions of a fastening ball and a release ball with respect to the shift rod in a state where the shift rod is further driven in the axial direction and rotated from the state of FIG. 11 (A3), and (B1) is It is a development view showing the sleeve at that time, (A2) is a perspective view showing the position of the fastening ball and the release ball with respect to the shift rod in the state where the cam pin is returned to the neutral position from the state of (A1), (B2 ) Is a development view showing the sleeve at that time. It is a top view which shows the movement locus | trajectory with respect to the shift rod of the fastening ball | bowl and the cancellation | release ball | bowl at the time of a skip transmission.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The multi-stage transmission shown in FIG. 1 has an input-side gear shaft 10 and an output-side gear shaft 20 arranged in parallel to the gear shaft 10. On the input side gear shaft 10, first to sixth speed driving gears 11 to 16 are mounted so as to be freely rotatable. The gear 11 is for the first speed, the gear 13 adjacent to the gear 11 is for the third speed, and the gear 15 adjacent to the gear 13 is for the fifth speed. The gear 12 adjacent to the gear 15 is for the second speed, the gear 14 adjacent to the gear 12 is for the fourth speed, and the gear 16 adjacent to the gear 14 is for the sixth speed. The plurality of first to sixth gears are each annular, and are adjacent in the axial direction in the order described above.

  The first to sixth gears 21 to 26 on the output side are fixed to the gear shafts 20 to 26, respectively. The gear 21 and the gear 11 form a first-speed transmission gear pair, the gear 22 and the gear 12 form a second-speed transmission gear pair, and the gear 23 and the gear 13 form a third-speed transmission gear pair. The gear 24 and the gear 14 form a 4-speed transmission gear pair, the gear 25 and the gear 15 form a 5-speed transmission gear pair, and the gear 26 and the gear 16 form a 6-speed transmission gear pair. Is done. Each transmission gear pair is always meshed. When any one of the plurality of freely rotatable gears 11 to 16 is fastened to the input side gear shaft 10, power is transmitted from the input side gear shaft 10 to the output side gear shaft 20. The multi-stage transmission shown in FIG. 1 has six shift stages, and the gears are switched by selecting a gear that is fastened to the gear shaft 10 from among the idled gears.

  An input clutch 32 is arranged between the crankshaft of the engine 31 and the input side gear shaft 10. When the input clutch 32 is fastened by an actuator (not shown), the power of the engine 31 is transmitted to the input side gear shaft 10. Is done. The output-side gear shaft 20 is hollow, and a front wheel output shaft 33 is rotatably incorporated therein via a bearing (not shown). The gear shaft 20 and the front wheel output shaft 33 are connected by a center differential device 34. The front wheel output shaft 33 is connected to a front wheel drive shaft (not shown) via a front differential device 35, and a front wheel (not shown) is driven by the drive shaft. The center differential device 34 is connected to a rear wheel output shaft 38 via a drive gear 36 and a driven gear 37. The rear wheel output shaft 38 is connected to a drive shaft for a rear wheel (not shown) via a rear differential device (not shown), and a rear wheel (not shown) is driven by the drive shaft.

  The input side gear shaft 10 is rotatably supported by the transmission case 17 by bearings 27a and 27b, the output side gear shaft 20 is rotatably supported by the transmission case 17 by bearings 28a, and the front wheel output shaft 33 is The bearing 28b is rotatably supported by the transmission case 17. Thus, FIG. 1 shows a four-wheel drive power transmission system in which the front wheels and the rear wheels are drive wheels.

  As shown in FIGS. 2 to 4, the input side gear shaft 10 has a hollow hole 40, and a shift rod 41 is attached to the hollow hole 40. The shift rod 41 rotates integrally with the gear shaft 10 and reciprocates in the axial direction with respect to the gear shaft 10, and is rotatable relative to the gear shaft 10. By driving the shift rod 41, any one of the plurality of drive-side gears 11 to 16 is fastened to the gear shaft 10.

  As shown in FIGS. 5 and 6, the gear shaft 10 has a small diameter portion corresponding to the gear 11, and between the inner peripheral surface 42 of the gear 11 and the outer peripheral surface 43 of the small diameter portion, An annular space 44 is provided. In the annular space 44, three swing arms 45 each extending in an arc shape in the circumferential direction are arranged at equal intervals in the circumferential direction. Support portions 46 protrude from both sides of the swing arm 45, and the support portions 46 are swingably mounted in support recesses 47 provided on the gear shaft 10 as shown in FIG. Spaces 44 are also provided between the inner peripheral surfaces of the other gears 12 to 16 and the outer peripheral surface 43 of the gear shaft 10, and three swing arms 45 are similarly disposed in the respective spaces 44. However, the number of the swing arms 45 provided in each of the gears 12 to 16 is not limited to three, and can be any number. However, when a plurality of swing arms 45 are provided, one swing arm 45 is provided. The load applied to the swing arm 45 can be reduced.

  FIG. 4 is a partially cutaway perspective view of the gear shaft 10. In FIG. 4, the gears 14 and 16 shown in FIG. 3 are removed, and one of the three swing arms 45 respectively disposed inside the gears 15 and 12 is shown. ing. A support recess 47 for supporting the support portion 46 of the swing arm 45 is provided on the gear shaft 10, and the arc surface of the support portion 46 abuts on the inner surface of the support recess 47, and swings about the contact portion. ing. The support 46 is covered with a snap ring 48 attached to the gear shaft 10. A bush 49 is fitted to the snap ring 48, and flanges 50 provided so as to protrude from both side surfaces of the respective gears 11 to 16 are fitted to the outside of the bush 49, and the bush 49 corresponds to the respective gears 11 to 16. Receives thrust reaction force.

  As shown in FIGS. 5 and 6, an engagement groove 51 is provided on the inner peripheral surface 42 of each of the gears 11 to 16, and an engagement claw 52 that enters the engagement groove 51 corresponds to each swing arm 45. Projecting radially outward at the tip of the. When the swing arm 45 swings about the arc surface of the support portion 46 to reach the fastening position, the front end surface 52a of the engagement claw 52 becomes the engagement surface 51a of the engagement groove 51 as shown in FIG. The gear 11 is brought into contact with the gear shaft 10, and the rotational torque of the gear shaft 10 is transmitted to the gear 11. On the other hand, as shown in FIG. 5, when the swing arm 45 swings to the release position for releasing the fastening, the engagement claw 52 is separated from the engagement groove 51, and the gear 11 is in an idle state with respect to the gear shaft 10. It becomes. Similarly, for the other gears 12 to 16, when the swing arm 45 is in the fastening position, the rotational torque of the gear shaft 10 is transmitted to the gear, and when the swing arm 45 is in the release position, the gear is relative to the gear shaft 10. Will be idle.

  As shown in FIG. 3, the shift rod 41 is provided with two fastening protrusions 53 at the same axial position. Each fastening protrusion 53 corresponds to a portion between the distal end portion of the swing arm 45 and the support portion 46, that is, a central portion in the longitudinal direction of the swing arm 45. In FIG. 3, the fastening protrusion 53 (a) shown with the symbol a on the left side drives the swing arm 45 provided inside the gears 11, 13, and 15 to the fastening position, and the symbol b on the right side. The fastening protrusion 53 (b) shown in FIG. 6 drives the swing arm 45 provided inside the gears 12, 14, 16 to the fastening position. The fastening protrusion 53 (b) is separated from the fastening protrusion 53 (a) by a distance including the axial dimensions of the three gears 11, 13, 15 and the neutral position. Three fastening protrusions 53 are provided on the same circumferential surface of the shift rod 41 so as to correspond to the swing arm 45. If the position shown in FIG. 3 is the forward limit position, the shift rod 41 is axially relative to the gear shaft 10 in the range of the stroke S between the forward limit position and the reverse limit position as shown in FIG. Moving. The reverse limit position of the shift rod 41 is a position where the fastening protrusion 53 (b) drives the swing arm 45 inside the gear 16 to the fastening position.

  As shown in FIGS. 5 and 6, the gear shaft 10 is provided with a holding hole 54, and the holding hole 54 passes through the hollow hole 40 and the outer peripheral surface 43. Is housed. When the fastening protrusion 53 is driven to the position of the swing arm 45 by the shift rod 41, as shown in FIG. 6, the shift rod 41 projects the fastening ball 55 radially outward and the swing arm 45 is fastened. It is driven to the fastening position by the shift rod 41 via the ball 55. As shown in FIG. 3, a guide groove 56 is provided on the outer peripheral surface of the shift rod 41 so as to extend in the axial direction. The guide groove 56 is provided over the range of the reciprocating stroke S of the shift rod 41, and the fastening protrusion 53 protrudes in the radial direction in a direction crossing the guide groove 56. As shown in FIGS. 5 and 6, three fastening balls 55 are provided on the same circumferential surface corresponding to the number of swing arms 45, and the guide grooves 56 also have a constant interval in the circumferential direction. Three are provided apart.

  In order to swing the swing arm 45 from the state where the swing arm 45 is in the fastening position as shown in FIG. 6 to the release position as shown in FIG. 57 is provided. The outer peripheral surface of the forcible release protrusion 57 is substantially the same outer diameter surface as the outer peripheral surface of the fastening protrusion 53. The forcible release protrusion 57 corresponds to the base end portion of the swing arm 45 and is provided at a position shifted in the circumferential direction and also in the axial direction with respect to the fastening protrusion 53. Therefore, as shown in FIG. 6, when the shift rod 41 is moved in the axial direction with the swing arm 45 in the fastening position, as shown in FIG. The swing arm 45 is swung by the forcible release protrusion 57 so that the base end portion is radially outward, and the swing arm 45 is in the release position.

  As shown in FIGS. 5 and 6, the gear shaft 10 is provided with a holding hole 58, the holding hole 58 passes through the hollow hole 40 and the outer peripheral surface 43, and a release ball 59 is provided in the holding hole 58. Be contained. As shown in FIG. 5, when the forcible release protrusion 57 is driven in the axial direction to the position of the swing arm 45, the shift rod 41 causes the release ball 59 to protrude radially outward, and the swing arm 45 is released. It is driven to the release position by the shift rod 41 via the ball 59. The shift rod 41 is provided with a retreat groove 60 at a position shifted in the circumferential direction with respect to the fastening protrusion 53. Therefore, as shown in FIG. 5, when the shift rod 41 is moved in the axial direction with the swing arm 45 in the release position, the release ball 59 is moved in the radial direction as shown in FIG. It moves inward and enters the retreat groove 60.

  FIG. 7 is a friction force characteristic diagram showing a friction force applied from the swing arm to the engagement surface 51a in a state where the swing arm 45 is engaged with the engagement surface 51a of the gear. When the engagement between the engagement claw 52 and the engagement groove 51 of the swing arm 45 is released, a forced release force P is applied from the forced release protrusion 57 to the base end portion of the swing arm 45.

  As shown in FIG. 7, in the state where the swing arm 45 is engaged with the engagement surface 51a and the gear 11 is fastened to the gear shaft 10, the swing arm 45 is engaged with the swing center O. A fastening load F is generated in a line connecting the mating surface 51a. By this fastening load F, a tooth surface load Fx is applied to the engagement surface 51a in the vertical direction. Therefore, as shown in FIG. 5, when driving torque remains between the swing arm 45 and the gear 11 when the swing arm 45 is driven to the release position, the swing arm 45 is fastened. A load F is generated. In FIG. 7, symbol Tg indicates the residual torque that acts on the front end surface 52a of the swing arm 45 from the gear engagement surface 51a, and the swing center of the support portion 46 of the swing arm 45 faces the residual torque Tg. Residual torque Ta in the direction acts from the gear shaft 10.

  Under this state, the load Fy in the direction parallel to the engagement surface 51a on which the fastening load F acts becomes the release force for releasing the engagement of the swing arm 45, and the tooth surface in the direction perpendicular to the engagement surface 51a. The load Fx becomes the resistance of the release force Fy. When the tooth surface load Fx acts on the engagement surface 51a, a frictional force f is applied to the tip surface 52a of the swing arm 45.

  The inclination angle α of the engagement surface 51a is set so that the direction of the tooth surface load Fx is inside the gear with respect to the fastening load F. As shown in the figure, the tooth surface load Fx is inward with respect to the fastening load F by an angle θ. As a result, the inclination angle α of the engagement surface 51a is an angle that is more open with respect to the radial line R of the shift rod 41 than when the tooth surface load Fx is outside the fastening load F. The tooth surface load angle θ formed by the tooth surface load Fx and the fastening load F is further set as follows based on the friction coefficient μ between the engagement surface 51a and the tip surface 52a of the swing arm 45.

  The release force Fy and the friction force f are expressed as follows.

Fy = F · sin θ, f = Fx · μ = F · cos θ · μ
In order to increase the release force Fy, it is necessary to satisfy the condition of Fy> f.

From the above equation, F · sin θ> F · cos θ · μ and sin θ / cos θ> μ are obtained, and the relationship of tan θ> μ is obtained. Therefore, when the angle of the engaging surface 51a is set so that θ> tan ⁻¹ · μ, even if the residual torque Tg is applied to the distal end surface of the swing arm 45, the self-locking is not caused. The arm 45 can be driven to the release position. Thus, the tooth surface load angle θ formed by the direction of the tooth load Fx and the direction of the fastening load F is inside the swing arm 45, and the tip surface 52a of the swing arm 45, the engagement surface 51a, If the friction coefficient between is?, The inclination angle α of the engagement surface 51a is set so that the tooth surface load angle θ satisfies θ> tan ⁻¹ · μ. As a result, when the shift rod 41 is driven from the engaged state where the gear is engaged to the gear shaft 10 to the released state by the shift rod 41, the swing arm 45 can be driven to the released state with a small forcible releasing force, and the actuator can be reduced in size. And a multi-stage transmission excellent in speed change characteristics can be obtained.

  8 is a partially cutaway perspective view showing a rod drive mechanism 61 for driving the shift rod 41 shown in FIGS. 3 and 4, and FIG. 9 is a longitudinal sectional view of FIG.

  The rod drive mechanism 61 has a sleeve 62 mounted on the outside of the shift rod 41 via a gap. As shown in FIG. 9, a spline 63a is provided at the base end portion of the hollow hole 40 of the gear shaft 10, and the outer peripheral surface of the distal end portion of the sleeve 62 meshes with the spline 63a so as to be movable in the axial direction. A spline 63b is provided. Therefore, the sleeve 62 rotates integrally with the gear shaft 10 and is movable in the axial direction with respect to the gear shaft 10.

  Two spring bearing members 64 and 65 are attached to the outer periphery of the base end portion of the shift rod 41 so as to face each other, and a compression coil spring 66 is mounted as a spring member between the two spring bearing members 64 and 65. The An annular stopper 67 that contacts the spring receiving member 64 and an annular stopper 68 that contacts the spring receiving member 65 are fixed to the inner peripheral surface of the sleeve 62. As shown in FIG. 9, the actuator 71 is arranged coaxially with the sleeve 62. The actuator 71 is coupled to the sleeve 62 via the coupling 72, and the reciprocating motion of the actuator 71 is transmitted to the sleeve 62 by the coupling 72 with respect to the rotating sleeve 62.

  As shown in FIG. 8, the sleeve 62 is provided with a cam groove 73, and a cam pin 74 that enters the cam groove 73 is fixed to the shift rod 41. The cam groove 73 includes an axial portion 73a that extends in the axial direction of the sleeve 62, and inclined portions 73b and 73c that are continuous with both ends of the sleeve 62 and are inclined in the circumferential direction. The spring force of the compression coil spring 66 is applied to the shift rod 41 so that the cam pin 74 is in the center portion of the axial direction portion 73a of the cam groove 73, that is, the neutral position. When the sleeve 62 is driven in the axial direction by a reference stroke corresponding to one gear position by the actuator 71, the compression coil spring 66 contracts at the start of the movement of the sleeve 62, and the fastening protrusion 53 swings through the fastening ball 55. The moving arm 45 is driven to the fastening position.

  FIG. 3 shows a state in which the shift rod 41 is in the forward limit position. At this time, all the drive-side gears 11 to 16 are idle with respect to the gear shaft 10, that is, in a neutral state. In order to fasten the first-speed gear 11 to the gear shaft 10 from this state, the actuator 71 drives the sleeve 62 rightward in FIG.

  FIG. 10A1 is a diagram showing the positions of the fastening ball 55 and the release ball 59 relative to the shift rod 41 when the swing arm 45 inside the gear 11 is in the release position, as shown in FIG. is there. Under this state, when the sleeve 62 is driven in the axial direction by the reference stroke S0 by the actuator 71, the sleeve 62 moves by the reference stroke S0 as shown in FIG. 10 (B1). In this moving process, the cam pin 74 moves in the axial direction within the range of the axial portion 73 a of the cam groove 73, the compression coil spring 66 of the rod drive mechanism 61 contracts, and the shift rod 41 has a spring force in the axial direction. Is added.

  When a spring force is applied to the shift rod 41, the shift rod 41 is driven by the reference stroke S0 as shown in FIG. 10A2, and the fastening ball 55 is pushed out radially outward by the fastening protrusion 53 (a). Accordingly, the release ball 59 enters the retreat groove 60. As a result, as shown in FIG. 10 (B2), the cam pin 74 is returned to the intermediate position in the axial direction of the axial portion 73a of the cam groove 73, and the swing arm 45 is fastened as shown in FIG. Driven to the position, the first-speed gear 11 is fastened to the gear shaft 10. 10 (B1) and 10 (B2), the cam groove 73 formed in the sleeve 62 is shown in an unfolded state. 10 (A1) and (A2), one fastening ball 55 and one release ball 59 are shown corresponding to one swing arm 45, and the other fastening balls 55 and release balls 59 are shown. Is omitted in the figure.

  When the first speed gear 11 is fastened to the gear shaft 10, the fastening protrusion 53 (b) shown in FIG. 3 approaches the fastening ball 55 inside the second speed gear 12. Similarly, when upshifting from the first speed to the second speed, the sleeve 71 is further driven to the right in FIG. 3 by the reference stroke S0 by the actuator 71. As a result, the swing arm 45 inside the first-speed gear 11 is driven to the release position as shown in FIG. 5, and the swing arm 45 inside the second-speed gear 12 is fastened as shown in FIG. Driven to position.

  Thus, the shift operation for one step is the same when upshifting from 2nd to 3rd, 3rd to 4th, etc., or downshifting from 6th to 5th, 5th to 4th, etc. is there.

  As shown in FIG. 10, the guide groove 56 protrudes in the circumferential direction from the fastening protrusion 53, and the guide groove 56 is entirely straight through a detour portion 56 a adjacent to the fastening protrusion 53. It is lined up. That is, the fastening protrusion 53 protrudes radially outward from the guide groove 56 so as to cross a part of the guide groove 56 that is connected in a straight line through the detour portion 56a as a whole. Therefore, when the shift rod 41 is rotated and driven in the axial direction, the fastening ball 55 can roll and move the fastening ball 55 to the guide groove 56 via the detour portion 56 a without riding on the fastening protrusion 53. Therefore, for example, when skipping at least one shift, such as 6th to 4th, or 6th to 1st, etc. The moving arm 45 can be maintained in the released state shown in FIG. As a result, the swing arm inside the gear of the gear to be skipped can be smoothly skipped without being driven to the fastening position, and a multi-speed transmission with excellent gear shifting characteristics can be obtained.

  11 and 12 show the positional relationship of the fastening ball 55 and the release ball 59 inside the gear to be skipped with respect to the shift rod 41 in the case of performing the skip shift as described above. For example, a description will be given of a case where the downshift is performed by shifting from the sixth speed to the fourth speed, etc. When the sixth speed gear 16 is fastened to the gear shaft 10, the fastening ball 55 and the release ball inside the fifth speed gear 15 are described. The positional relationship between 59 and the fastening protrusion 53 (b) is as shown in FIG. 11A1, the fastening ball 55 enters the guide groove 56, and the release ball 59 protrudes radially outward by the forced release protrusion 57. ing.

  Under this state, when the sleeve 62 is driven in the downshift direction, the shift rod 41 is not driven in the axial direction as shown in FIG. 73a moves in the axial direction along the cam pin 74. As shown in FIG. 11 (B2), when the cam pin 74 enters the inclined portion 73c of the cam groove 73 by the subsequent movement of the sleeve 62, the cam pin 74 is guided to the inclined portion 73c, and the shift rod 41 is moved as shown in FIG. As shown in (A2), it is rotated toward a position continuous with the detour part 56a. When the shift rod 41 rotates in this way, the release ball 59 moves in the circumferential direction with respect to the shift rod 41 and moves away from the position of the axial extension line of the retreat groove 60. When the cam pin 74 is in contact with the terminal end of the inclined portion 73c, the compression coil spring 66 is in the most contracted state. When the sleeve 62 is further driven in the axial direction, the fastening ball 55 passes through the detour portion 56a of the guide groove 56 without riding on the fastening protrusion 53, as shown in FIG. Thereby, the fastening protrusion 53 is prevented from being pressed by the swing arm 45 via the fastening ball 55.

  When the sleeve 62 driven by the actuator 71 stops at the fourth speed position, as shown in FIG. 12 (B1), the cam pin 74 is axially moved along the inclined portion 73c by the spring force of the contracted compression coil spring 66. It is driven toward 73a. Accordingly, as shown in FIG. 12A1, the shift rod 41 is rotated and driven in the axial direction. Further, the cam pin 74 is driven to the intermediate position of the axial direction portion 73a by the spring force as shown in FIG. 12 (B2). Accordingly, as shown in FIG. 12A2, the fastening ball 55 bypasses the fastening protrusion 53 (b) and moves to the guide groove 56, and the release ball 59 bypasses the retraction groove 60. The state in contact with the forcible release protrusion 57 is maintained. Therefore, when shifting from the 6th speed to the 4th speed, the swing arm 45 inside the 5th gear 15 is in the release position as shown in FIG. Continue to maintain.

  FIG. 13 shows the trajectory of the detour movement of the fastening ball 55 and the release ball 59 with respect to the shift rod 41 in the case of skipping and shifting as described above.

  When shifting from 6th speed to 3rd speed, 2nd speed, 1st speed, etc., as shown in FIG. 11 (B3), the gear shaft 10 remains in a state where the cam pin 74 is in contact with the end of the inclined portion 73c. The shift rod 41 is driven at a stroke to the position of the gear to be fastened. At this time, the fastening ball 55 inside the gear to be skipped passes through the detour portion 56a. In this way, when performing the skipping shift, the swing arm 45 inside the gear to be skipped does not open and close between the fastening position and the release position, so that the skipping shift can be performed smoothly, Characteristics can be improved.

  3 and FIG. 9, the sleeve 62 is driven leftward, and in the skipping operation, the cam pin 74 is guided to the inclined portion 73c and the shift rod 41 is rotated. On the other hand, in the case of upshifting by skipping shift, the sleeve 62 is driven rightward. At this time, in the skipping operation, the cam pin 74 is guided to the inclined portion 73b and the shift rod 41 is rotated. However, in the case of performing a shifting shift only when downshifting, only the inclined portion 73c is provided, and the inclined portion 73b is unnecessary.

  As shown in FIG. 3, the odd-numbered gears are adjacent to each other as one group, the even-numbered gears are adjacent to each other as one group, and two fastening protrusions 53 are provided on the shift rod 41. As described above, when the gears 11 to 16 are grouped into a plurality of groups and the plurality of fastening protrusions 53 are provided on the shift rod 41, the shift stroke of the shift rod 41 can be shortened as compared with the case of using one fastening protrusion. The above-described multi-stage transmission can be applied not only to an automatic transmission for a vehicle but also to a manual type, that is, a manual type transmission.

  In the illustrated multi-stage transmission, when the swing arm 45 is driven to the fastening position by the fastening protrusion 53 via the fastening ball 55 and the swing arm 45 is driven to the release position, the forced release protrusion via the release ball 59. The swing arm 45 is swung by 57. On the other hand, the swinging arm 45 may be directly driven to the fastening position by the engaging protrusion and directly driven to the releasing position by the forced releasing protrusion 57 without the fastening ball 55 and the releasing ball 59 interposed. However, as compared with such a configuration, by interposing the ball, the swing arm 45 can be smoothly opened and closed by rolling the ball. In the rod drive mechanism 61 shown in FIGS. 8 and 9, the cam pin 74 is provided on the shift rod 41. However, the cam pin 74 protrudes toward the shift rod 41 on the inner surface of the sleeve 62 so as to shift the shift rod 41. Even if the cam groove 73 is formed, the gear position can be similarly switched. That is, the cam pin 74 is provided on one of the shift rod 41 and the sleeve 62, and the cam groove 73 is provided on the other of the shift rod 41 and the sleeve 62.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, FIG. 1 shows a multi-stage transmission applied to a power transmission system for four-wheel drive, but the multi-stage transmission can also be applied to a multi-stage transmission for driving front wheels. Further, the drive side gear is mounted on the input side gear shaft 10 so as to be free to rotate, and the driven side gear is fixed to the output side gear shaft 20, but the driven side gear can be idled to the gear shaft 20. It may be mounted and the shift rod 41 may be provided on the gear shaft 20. In this way, one gear on the driving side and the driven side can be fixed to the gear shaft, and the other gear can be mounted on the gear shaft so as to freely rotate.

DESCRIPTION OF SYMBOLS 10 Input side gear shaft 11-16 Drive side gear 20 Output side gear shaft 21-26 Drive side gear 32 Input clutch 41 Shift rod 45 Swing arm 46 Support part 47 Support recessed part 51 Engagement groove 51a Engagement surface 52 engaging claw 52a tip surface 53 fastening projection 55 fastening ball 56 guide groove 56a detouring portion 57 forcible release projection 59 release ball 60 retraction groove 61 rod drive mechanism 62 sleeve 66 compression coil spring 71 actuator 73 cam groove 73a axial portion 73b, 73c Inclined part 74 Cam pin

Claims (5)

An input-side gear shaft provided with a plurality of drive-side gears, and an output-side gear shaft provided with a plurality of driven-side gears that always mesh with the drive-side gears to form a transmission gear pair. One of the driving and driven gears forming the transmission gear pair is fixed to the gear shaft, the other gear is rotatably mounted on the gear shaft, and the idle gear is fastened to the gear shaft. In a multi-stage transmission that switches the gear position,
A swing arm that is swingably mounted inside the idler gear and has an engaging claw that engages with an engagement surface provided on the idler gear;
A shift rod mounted in a hollow hole provided in the gear shaft so as to be capable of reciprocating and rotating in the axial direction;
A fastening protrusion provided on the shift rod, and pressing the engaging claw against the engaging surface to fasten the free-wheeling gear to the gear shaft;
A forcible release protrusion that is provided on the shift rod and presses the base end of the swing arm when releasing the fastening of the gear;
Tooth surface load angle formed by the direction of the tooth surface load applied from the swing arm in the direction perpendicular to the engagement surface and the direction of the fastening load applied between the swing center of the swing arm and the engagement surface When θ is inside the swing arm and the friction coefficient between the tip surface of the swing arm and the engagement surface is μ, the tooth surface load angle θ is a condition of θ> tan ⁻¹ · μ. A multi-stage transmission in which an inclination angle of the engagement surface is set so as to satisfy   2. The multi-stage transmission according to claim 1, wherein a bypass portion provided in the shift rod adjacent to the fastening protrusion in a circumferential direction, the shift rod is driven in an axial direction, and at least one of the idler gears is skipped. And a rod drive mechanism that rotates the shift rod to avoid pressing the swing arm by the fastening protrusion when the other gear is fastened. The multi-stage transmission according to claim 1 or 2,
A fastening ball is disposed between the shift rod and the central portion in the longitudinal direction of the swing arm,
A guide groove into which the fastening ball enters is provided over the length of the reciprocating stroke of the shift rod,
The fastening protrusion is provided on the shift rod across the guide groove adjacent to the bypass portion of the guide groove in the circumferential direction,
A release ball is disposed between the forced release protrusion of the shift rod and a base end of the swing arm;
A multi-stage transmission in which a retraction groove into which the release ball enters is provided in the shift rod at a position shifted in a circumferential direction of the fastening protrusion.   The multi-stage transmission according to any one of claims 1 to 3, wherein a plurality of the swing arms are provided inside the idler gear.   5. The multi-stage transmission according to claim 1, wherein a plurality of drive-side gears provided on the input-side gear shaft are rotatably mounted on the input-side gear shaft, and the shift rod is provided. Is provided on the gear shaft on the input side.

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