JP2017211080A - Synchromesh mechanism and transmission mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synchromesh mechanism and a transmission mechanism capable of restricting a torque shortage producing sense of running or the like when gears are changed over.SOLUTION: A synchromesh mechanism 10 comprises: a shaft; a gear 20 and a gear 30 each of which is rotatably supported at the shaft and formed with a tapered cone-shaped surface; a sleeve 50 integrally rotated with the shaft and changing-over an engagement between the gear 20 and the gear 30; a synchronizer ring 60 aligning the number of rotations of the gear 20 and the sleeve 50 through frictional force generated between itself and the tapered cone-shaped surface of the gear 20; and a synchronizer ring 70 aligning the number of rotations of the gear 30 and the sleeve 50 through frictional force generated between itself and the tapered-cone surface of the gear 30. The sleeve 50 has a length that enables it to be contacted simultaneously with the synchronizer ring 60 and the synchronizer ring 70.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a synchromesh mechanism for shifting and a shifting mechanism mounted on a vehicle or the like.

  Conventionally, as a synchromesh mechanism for a speed change mechanism mounted on a vehicle, when a gear connected to a sleeve that rotates integrally with a shaft is switched from one of two gears having a rotational speed difference to the other, A device that synchronizes the rotational speed of the gear and the rotational speed of the sleeve is known (for example, see Patent Documents 1-3).

JP-A-5-141488 JP-A-9-042314 JP 9-090002 A

  However, in the synchromesh mechanism, both the dog clutch that connects one gear and the sleeve and the dog clutch that connects the other gear and the sleeve are temporarily disconnected at the same time when the gear is switched, and power is transmitted to the shaft. As a result, a so-called torque interruption occurs, which causes a problem that the vehicle driver feels idle. This problem becomes more prominent when gears are automatically switched.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a synchromesh mechanism and a transmission mechanism that can suppress a torque break that causes an idling feeling at the time of gear switching.

  The synchromesh mechanism of the present invention includes a shaft, a first gear that is rotatably supported by the shaft, a first conical surface is formed, and a shaft that is rotatably supported by the shaft. A second gear having a different speed stage from the first gear and having a second conical surface formed thereon, and is supported by the shaft so as to rotate integrally with the shaft and to be movable in the extending direction of the shaft. First, which promotes synchronization of the first gear and the sleeve by a frictional force generated between the sleeve that switches the meshing between the first gear and the second gear and the first conical surface. And a second synchronizer ring that promotes synchronization of the second gear and the sleeve by a frictional force generated between the second conical surface, Reeve, wherein said a first synchronizer ring and said second synchronizer ring to simultaneously contact possible length.

  With this configuration, the synchromesh mechanism of the present invention has a length that allows the sleeve to be in contact with the first synchronizer ring and the second synchronizer ring at the same time. Therefore, switching from the first gear to the second gear is possible. Sometimes, after the meshing of the sleeve and the first gear is released, the second synchronizer ring is pushed directly or indirectly by the sleeve to contact the second conical surface of the second gear and apply a frictional force. The first synchronizer ring is pushed directly or indirectly by the sleeve after the meshing of the sleeve and the second gear is released at the time until the generation and the switching from the second gear to the first gear. The time until the frictional force is generated by contacting the first conical surface of the first gear is shorter than that of the conventional art. Therefore, the synchromesh mechanism of the present invention can suppress the torque interruption at the time of gear switching compared to the conventional art.

  In the synchromesh mechanism of the present invention, when the sleeve moves from the state of meshing with the second gear to the first gear side, at least before the contact with the second gear is released, The length may be such that the first synchronizer ring is indirectly pressed to bring the first synchronizer ring into contact with the first conical surface.

  With this configuration, the synchromesh mechanism of the present invention is configured so that when the sleeve is switched from the state of meshing with the second gear to the state of meshing with the first gear, at least before the contact between the sleeve and the second gear is released. Since the first synchronizer ring is pushed indirectly by the sleeve to bring the first synchronizer ring into contact with the first conical surface of the first gear to generate a frictional force, the second gear to the first gear Torque out at the time of switching to can be suppressed, the feeling of running idle can be suppressed.

  In the synchromesh mechanism of the present invention, when the sleeve moves from the state of meshing with the second gear to the first gear side, contact with the second gear, and the first synchronizer ring It may be the maximum length that occurs only when the contact with is different.

  With this configuration, the synchromesh mechanism according to the present invention enables the sleeve to be immediately after the contact between the sleeve and the second gear is released when the sleeve is switched from the state in which the sleeve is engaged with the second gear to the state in which the sleeve is engaged with the first gear. The first synchronizer ring is pushed directly by the contact to bring the first synchronizer ring into contact with the first conical surface of the first gear to generate a frictional force, so that the switching from the second gear to the first gear is performed. Torque out of time can be suppressed, and a feeling of idling can be suppressed.

  In the synchromesh mechanism according to the present invention, the second gear is disposed between the second gear and the sleeve when the sleeve moves from the state of meshing with the second gear to the first gear side. An inclined surface that contacts the sleeve by relative rotation and pushes the sleeve toward the first gear may be formed.

  With this configuration, the synchromesh mechanism of the present invention allows the second gear to move by the relative rotation between the second gear and the sleeve when the sleeve moves from the state of meshing with the second gear to the first gear side. Since the inclined surface of the first sleeve contacts the sleeve and pushes the sleeve toward the first gear, an operating force for indirectly contacting the first synchronizer ring with the first conical surface of the first gear by the sleeve is provided. Can be reduced.

  A speed change mechanism according to the present invention is a speed change mechanism including the above-described synchromesh mechanism, wherein the synchromesh mechanism switches a continuous speed among the speeds of the speed change mechanism.

  With this configuration, the speed change mechanism of the present invention suppresses torque interruption by the synchromesh mechanism at the time of switching between successive speeds, so that the speeds can be switched smoothly.

  The synchromesh mechanism and the speed change mechanism of the present invention can suppress a feeling of idle running at the time of gear switching by suppressing torque interruption at the time of gear switching.

1 is a block diagram showing a schematic configuration of a vehicle equipped with a synchromesh mechanism according to a first embodiment of the present invention. FIG. 2 is a front sectional view of the synchromesh mechanism for the speed change mechanism shown in FIG. 1. It is a schematic sectional side view of a part of synchromesh mechanism shown in FIG. FIG. 3 is a front sectional view of a part of the synchromesh mechanism shown in FIG. 2 in a state where a sleeve is engaged with a gear. It is a top view of a part of the synchromesh mechanism in the state shown in FIG. (A) It is front sectional drawing of a part of the synchromesh mechanism shown in FIG. 2 in a state where the friction surface of the synchronizer ring is in contact with the tapered cone surface of the gear when the synchronizer key presses the synchronizer ring. . (B) It is a partial top view of the synchromesh mechanism in the state shown in FIG. (A) It is front sectional drawing of a part of synchromesh mechanism shown in FIG. 2 in the state in which the friction surface of a synchronizer ring is contacting the taper cone surface of a gear by a sleeve pushing a synchronizer ring. (B) It is a top view of a part of the synchromesh mechanism in the state shown in FIG. (A) It is front sectional drawing of a part of synchromesh mechanism shown in FIG. 2 in the state which the synchronization with rotation of a synchronizer ring and rotation of a gear was completed. (B) It is a top view of a part of the synchromesh mechanism in the state shown in FIG. (A) It is front sectional drawing of a part of synchromesh mechanism shown in FIG. 2 in the state which the sleeve has meshed | engaged with the gear. (B) It is a top view of a part of the synchromesh mechanism in the state shown in FIG. It is a block diagram of an example of the speed change mechanism shown in FIG. It is sectional drawing of the speed change mechanism which concerns on the 2nd Embodiment of this invention in the state of 1st speed. FIG. 12 is a skeleton diagram of the speed change mechanism shown in FIG. 11. FIG. 12 is a block diagram of a control system of the speed change mechanism shown in FIG. 11. FIG. 12 is a cross-sectional view of the speed change mechanism shown in FIG. 11 in the second speed state. FIG. 12 is a cross-sectional view of the speed change mechanism shown in FIG. 11 when in a third speed state. FIG. 12 is a cross-sectional view of the speed change mechanism shown in FIG. 11 when in a fourth speed state. FIG. 12 is a cross-sectional view of the speed change mechanism shown in FIG. 11 when switching from second speed to third speed. FIG. 12 is a cross-sectional view of the speed change mechanism shown in FIG. 11 when switching from the third speed to the fourth speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, the configurations of the synchromesh mechanism and the transmission mechanism according to the first embodiment will be described.

  FIG. 1 is a block diagram showing a schematic configuration of a vehicle 1 equipped with a synchromesh mechanism and a transmission mechanism according to the present embodiment.

  As shown in FIG. 1, the vehicle 1 transmits power from a power source 2 such as an engine or a motor, wheels 3, and power from the power source 2 side to the wheel 3 side by changing torque, rotation speed, and rotation direction. A transmission mechanism 4 and a starting clutch 5 that is disposed between the power source 2 and the transmission mechanism 4 and changes the transmission state of power from the power source 2 side to the transmission mechanism 4 side are provided. When the power source 2 is a motor, the starting clutch 5 is not necessary. Although not shown, a final reduction gear and a differential gear are provided between the speed change mechanism 4 and the wheels 3.

  FIG. 2 is a front sectional view of the synchromesh mechanism 10 used in the transmission mechanism 4. FIG. 3 is a schematic sectional side view of a part of the synchromesh mechanism 10. FIG. 4 is a front sectional view of a part of the synchromesh mechanism 10 in a state where the sleeve 50 is engaged with the gear 30. FIG. 5 is a top view of a part of the synchromesh mechanism 10 in the state shown in FIG.

  As shown in FIGS. 2 to 5, the synchromesh mechanism 10 includes a shaft 11 that transmits power to the wheel 3 (see FIG. 1) side, and a gear 20 that is rotatably supported on the shaft 11 by a bearing 12. The bearing 12 is rotatably supported by the shaft 11 by a bearing 13 disposed at a position on the left side in the axial direction in FIG. 2, and the gear 30 is different from the gear 20 between the gears 20 and 30. A hub 40 that is provided integrally with the shaft 11 in the direction of rotation, a sleeve 50 that is supported by the hub 40 so as to be integrated in the direction of rotation and movable in the axial direction, and a tapered cone surface that is integral with the gears 20 and 30, respectively. 22 and 32 and dog gears 23 and 33 and a synchronizer ring capable of generating friction torque between the tapered cone surfaces 22 and 32 when pressed by the sleeve 50 And 60 and 70, and a fittable synchronizer key 14 to the sleeve 50.

  A hub 40 is disposed on the shaft 11 between the bearing 12 and the bearing 13 in the extending direction, that is, in the axial direction, and a spline 41 provided on the inner peripheral surface and extending in the axial direction is provided on the shaft 11. The hub 40 and the shaft 11 are rotated together with a spline 11 a formed on the outer periphery of the hub 11.

  The gear 20 is provided with teeth 21 on the outer periphery of the end opposite to the hub 40 side, and is always meshed with a speed change gear (not shown). The gear 20 has a tapered cone surface 22 formed on the outer periphery of the left end in FIG. In addition, a dog gear 23 extending in the axial direction is provided on the outer periphery of the gear 20 between the teeth 21 and the tapered cone surface 22 in the axial direction. In the dog gear 23, a chamfer 23a as an inclined surface inclined with respect to the axial direction is formed at the left end portion in FIG.

  The gear 30 is provided with teeth 31 on the outer periphery of the left end portion in FIG. 2 in the axial direction, and is always meshed with a gear for shifting (not shown). The gear 30 has a tapered cone surface 32 formed on the outer periphery of the right end portion in FIG. A dog gear 33 is provided on the outer periphery of the gear 30 between the teeth 31 and the tapered cone surface 32 in the axial direction. The dog gear 33 is formed with a chamfer 33a as an inclined surface inclined with respect to the axial direction at the right end in FIG.

  When the gear 20 is the first gear of the present invention, the tapered cone surface 22, the gear 30, the tapered cone surface 32, the synchronizer ring 60, and the synchronizer ring 70 are respectively the first conical surface of the present invention. , Second gear, second conical surface, first synchronizer ring, second synchronizer ring. Similarly, when the gear 30 is the first gear of the present invention, the gear 20, the tapered cone surface 22, the tapered cone surface 32, the synchronizer ring 60, and the synchronizer ring 70 are respectively the second gear of the present invention. , Second conical surface, first conical surface, second synchronizer ring, first synchronizer ring. For example, the gears 20 and 30 are driven gears for realizing the first speed and the second speed, respectively. These gears 20 and 30 are disposed concentrically on the center line 10a.

  The hub 40 is disposed between the gear 20 and the gear 30 in the axial direction, and a spline 41 formed on the inner periphery thereof meshes with the spline 11a of the shaft 11 so as to rotate integrally with the shaft 11. On the other hand, a spline 42 extending in the axial direction is formed on the outer periphery of the hub 40. The hub 40 has grooves 43 extending in the radial direction at three equally spaced locations in the circumferential direction.

  The sleeve 50 is provided with a spline 51 extending in the axial direction on the inner periphery, meshed with the spline 42 of the hub 40, and supported by the hub 40 so as to rotate integrally with the hub 40 and move in the axial direction. The spline 51 can mesh with the dog gear 23 of the gear 20 when moving to the right side from the neutral position in FIG. 2, and the dog gear 33 of the gear 30 when moving to the left side. That is, the sleeve 50 can switch the meshing with the gear 20 and the gear 30 by moving in the axial direction. In the spline 51, a chamfer 51a inclined with respect to the axial direction is formed at the gear 20 side end portion, and a chamfer 51b inclined with respect to the axial direction is formed at the gear 30 side end portion. In the spline 51, a groove 51c along the circumferential direction is formed near the right side from the center in the axial direction, and a groove 51d along the circumferential direction is formed near the left side from the center in the axial direction. The grooves 51c and 51d are respectively formed with slopes at both ends in the axial direction. An annular groove 52 extending in the circumferential direction, into which the shift fork 16 is fitted, is formed at the center of the outer periphery of the sleeve 50. As will be described later, in addition to the above configuration, the dimensional relationship of meshing between the gears 20 and 30 of the sleeve 50 and the dog gears 23 and 33 and the relationship between the sleeve 50 and the synchronizer key 14 are different from those of the prior art. It is.

  The synchronizer ring 60 is disposed between the hub 40 and the gear 20, and a conical friction surface 61 corresponding to the tapered cone surface 22 of the gear 20 is formed on the inner periphery. A spline 62 that can mesh with the spline 51 of the sleeve 50 is provided on the outer periphery of the synchronizer ring 60. In the spline 62, a chamfer 62a inclined with respect to the axial direction is formed at the left end in FIG. Further, the synchronizer ring 60 has a structure in which a part (not shown) is inserted into a groove (not shown) of the hub 40 and the like, for example, about one pitch of the spline 62 in the circumferential direction with respect to the hub 40. In a rotatable state, the rotation with respect to the hub 40 is restricted.

  On the other hand, the synchronizer ring 70 is disposed between the hub 40 and the gear 30, and a conical friction surface 71 corresponding to the tapered cone surface 32 of the gear 30 is formed on the inner periphery. A spline 72 that can mesh with the spline 51 of the sleeve 50 is provided on the outer periphery of the synchronizer ring 70. In the spline 72, a chamfer 72a inclined with respect to the axial direction is formed at the right end in FIG. The synchronizer ring 70 can be rotated in the circumferential direction with respect to the hub 40 by, for example, about one pitch of the spline 72 by a structure in which a part (not shown) is inserted into a groove (not shown) of the hub 40. In this state, the rotation with respect to the hub 40 is restricted.

  The synchronizer key 14 is disposed in the groove 43 of the hub 40. In the present embodiment, these synchronizer keys 14 can be selectively fitted into either the groove 51c or the groove 51d of the sleeve 50, and are used at three positions spaced equally in the circumferential direction. A protrusion 14 a is provided on the outer periphery of the synchronizer key 14 and is fitted in either the groove 51 c or the groove 51 d of the sleeve 50. The protrusion 14a has slopes at both ends in the axial direction. The inclination angle of these slopes, the inclination angle of the left side surface of the groove 51c of the sleeve 50 in FIG. 2, the inclination angle of the right side surface of the groove 51d in FIG. 2, the chamfer angle of the synchronizer rings 60 and 70, etc. are appropriately set. As long as the friction torque is generated by the axial pressing of the sleeve 50 between the tapered cone surfaces 22 and 32 of the gears 20 and 30 and the friction surfaces 61 and 71 of the synchronizer rings 60 and 70, The synchronizer rings 60 and 70 are dragged by the rotation of the gears 20 and 30 so as to be relatively rotated with respect to the sleeve 50, and the spline 51 of the sleeve 50 and the splines 62 and 72 of the synchronizer rings 60 and 70 are in the axial direction. Can be maintained in an opposing position at 50 to prevent further axial movement of the sleeve 50. If the friction torque is eliminated in synchronism, the sleeve 50 which is pushed in the axial direction pushes the chamfers 62a and 72a of the synchronizer rings 60 and 70 to move the synchronizer rings 60 and 70 in the reverse direction with respect to the sleeve 50. The spline 51 of the sleeve 50 and the splines 62 and 72 of the synchronizer rings 60 and 70 are not opposed to each other in the axial direction, and further axial movement is possible.

  The synchronizer key 14 is biased by a pair of springs 15 in the radially outward direction on the left and right sides in the axial direction. The synchronizer key 14 receives a centrifugal force in the radially outward direction when the shaft 11 rotates, and therefore when the gear is switched. Therefore, the synchromesh mechanism 10 does not necessarily include the spring 15.

  The shift fork 16 is configured such that a protruding portion provided on the inner periphery thereof fits in a part of the groove 52 of the sleeve 50 so that the sleeve 50 can be moved in the axial direction while being relatively rotatable. The shift fork is moved in the axial direction by driving an actuator (not shown) by a control unit (not shown). The control unit is configured to control the driving of the actuator by receiving a signal from a sensor that detects the rotational speed of the output shaft, the engine load, and the like and calculating the type and timing of gear switching.

  Next, the operation of the synchromesh mechanism 10 will be described.

  In the following, an operation for switching from a state in which the sleeve 50 is engaged with the gear 30 to a state in which the sleeve 50 is engaged with the gear 20 will be described. However, the same applies to the operation of switching the state in which the sleeve 50 is engaged with the gear 20 to the state in which the sleeve 50 is engaged with the gear 30, and the description in this case is omitted.

  The synchromesh mechanism 10 is in the state shown in FIGS. 4 and 5 when the sleeve 50 is engaged with the gear 30. That is, the sleeve 50 rotates together with the gear 30 because the spline 51 meshes with the dog gear 33 of the gear 30. Therefore, the shaft 11 including the spline 11 a meshing with the spline 41 of the hub 40 including the spline 42 meshing with the spline 51 of the sleeve 50 rotates together with the gear 30.

  Here, in the following description, the gear 20 and the gear 30 rotate in the downward direction in FIG. 5 (hereinafter referred to as “first rotation direction” and indicated by an arrow 10 f in FIG. 5). Shall. Further, the gear 20 is assumed to be slower in rotation speed than the gear 30. In this case, the spline 51 is pushed in the first rotation direction from the dog gear 33 existing in the direction opposite to the first rotation direction (hereinafter referred to as “second rotation direction” and indicated by the arrow 10 g in FIG. 5). Then, the spline 42 existing on the first rotation direction side is pushed in the first rotation direction.

  When the shift fork 16 starts moving in the gear 20 side direction according to the operation of the shift lever by the actuator, the sleeve 50 in which the groove 52 into which the shift fork 16 is fitted starts moving in the same direction.

  When the sleeve 50 starts moving in the gear 20 side direction, the synchronizer key 14 in which the protruding portion 14a is fitted in the groove 51c of the sleeve 50 is pushed by the slope of the protruding portion 14a against the slope of the groove 51c. Start moving sideways.

  When the synchronizer key 14 moves in the gear 20 side direction and contacts the synchronizer ring 60, the synchronizer ring 60 is pushed in the gear 20 side direction by the synchronizer key 14. That is, the sleeve 50 indirectly pushes the synchronizer ring 60 in the same direction via the synchronizer key 14. Accordingly, the synchronizer ring 60 moves in the gear 20 side direction and contacts the tapered cone surface 22 of the gear 20 at the friction surface 61. That is, the synchromesh mechanism 10 is in the state shown in FIG.

  FIG. 6A shows the synchromesh mechanism 10 in a state where the friction surface 61 of the synchronizer ring 60 is in contact with the tapered cone surface 22 of the gear 20 when the synchronizer key 14 pushes the synchronizer ring 60. It is front sectional drawing of a part. FIG. 6B is a top view of a part of the synchromesh mechanism 10 in the state shown in FIG.

  As described above, the hub 40 rotates in the first rotation direction together with the gear 30. Here, the gear 20 also rotates in the same direction but has a rotation speed slower than that of the gear 30, and therefore rotates relative to the hub 40 in the second rotation direction. Therefore, the synchronizer ring 60 rotates relative to the hub 40 in the second rotational direction when the friction surface 61 receives the frictional force in the second rotational direction from the tapered cone surface 22 of the gear 20, and thus the circumferential direction relative to the hub 40. In the rotatable angle range in FIG. 6, it stops at the end position in the second rotation direction as shown in FIG. 6 (b). That is, the synchronizer ring 60 is stopped in a state in which the spline 62 is rotated in the second rotational direction by about a half pitch of the spline 62 with respect to the position where the spline 62 meshes with the spline 51 of the sleeve 50. That is, at this time, the spline 51 of the sleeve 50 is in contact with the chamfer 33a of the dog gear 33 of the gear 30 and is engaged with the spline 72 of the synchronizer ring 70, but the spline 62 of the synchronizer ring 60 is also geared. The dog gear 23 is not meshed.

  In the state shown in FIG. 6, the chamfer 33 a of the dog gear 33 of the gear 30 is still in contact with the chamfer 51 b of the spline 51 of the sleeve 50, so that the sleeve 50 moves in the first rotation direction of the gear 30 relative to the sleeve 50. Along with the rotation, the gear 30 pushes in the gear 20 side direction. In this way, when the frictional surface 61 of the synchronizer ring 60 is pressed against the tapered cone surface 22 of the gear 20 by the pressing force from the sleeve 50 and the frictional force generated between them increases, the rotation of the synchronizer ring 60 rotates. And the rotation of the gear 20 are synchronized.

  When the sleeve 50 further moves in the gear 20 side direction from the state shown in FIG. 6, the synchronizer key 14 causes the biasing force and the synchronization by the spring 15 to be generated by the slope of the protrusion 14 a being pushed by the slope of the groove 51 c of the sleeve 50. The protrusion 14a is partially removed from the groove 51c by moving radially inward by the pressing force of the sleeve 50 in accordance with the resultant force of the centrifugal force acting on the nizer key 14. Accordingly, the sleeve 50 advances to the gear 20 side, and the chamfer 51a of the spline 51 of the sleeve 50 contacts the chamfer 62a of the spline 62 of the synchronizer ring 60 as shown in FIG.

  FIG. 7A shows a part of the synchromesh mechanism 10 in a state where the friction surface 61 of the synchronizer ring 60 is in contact with the tapered cone surface 22 of the gear 20 by the sleeve 50 pushing the synchronizer ring 60. It is front sectional drawing. FIG. 7B is a top view of a part of the synchromesh mechanism 10 in the state shown in FIG.

  As shown in FIG. 7, the synchronizer ring 60 pushed in the gear 20 side direction by the sleeve 50 increases the frictional force generated between the friction surface 61 and the tapered cone surface 22 of the gear 20. Therefore, the synchronization between the rotation of the synchronizer ring 60 and the rotation of the gear 20, that is, the synchronization between the rotation of the sleeve 50 and the rotation of the gear 20 proceeds.

  When the synchronization between the rotation of the synchronizer ring 60 and the rotation of the gear 20 is completed, the friction surface 61 does not receive the friction torque in the second rotation direction from the tapered cone surface 22 of the gear 20. Therefore, the spline 51 of the sleeve 50 rotates the synchronizer ring 60 with respect to the sleeve 50 in the first rotation direction via the chamfer 62a of the spline 62. Therefore, the spline 51 of the sleeve 50 further advances and meshes with the spline 62 of the synchronizer ring 60 as shown in FIG.

  FIG. 8A is a front sectional view of a part of the synchromesh mechanism 10 in a state where the synchronization of the rotation of the synchronizer ring 60 and the rotation of the gear 20 is completed. FIG. 8B is a top view of a part of the synchromesh mechanism 10 in the state shown in FIG.

  In the state shown in FIG. 8, in the synchronizer key 14, the protruding portion 14 a comes out of the groove 51 c of the sleeve 50 and is further pushed inward in the radial direction.

  When the sleeve 50 further moves in the gear 20 side direction from the state shown in FIG. 8, when the chamfer 51 a of the spline 51 of the sleeve 50 comes into contact with the chamfer 23 a of the dog gear 23 of the gear 20, the sleeve 50 is brought into contact with the chamfer 51 a and chamfer 23 a. 50 and the gear 20 are relatively rotated in the circumferential direction, and the chamfer 51a and the chamfer 23a are not in contact with each other. When the chamfer 51a does not contact the chamfer 23a, the sleeve 50 meshes with the dog gear 23 of the gear 20 by the spline 51 as shown in FIG.

  FIG. 9A is a front sectional view of a part of the synchromesh mechanism 10 in a state where the sleeve 50 is engaged with the gear 20. FIG. 9B is a top view of a part of the synchromesh mechanism 10 in the state shown in FIG.

  In the state shown in FIG. 9, the gear switching is completed, and the sleeve 50 rotates together with the gear 20 because the spline 51 is engaged with the dog gear 23 of the gear 20. Accordingly, the shaft 11 including the spline 11 a meshing with the spline 41 of the hub 40 including the spline 42 meshing with the spline 51 of the sleeve 50 rotates together with the gear 20.

  Here, since the gear 20 is rotating in the first rotation direction, the spline 51 is pushed in the first rotation direction from the dog gear 23 existing in the second rotation direction, and the spline 42 existing in the first rotation direction is moved. Press in the first rotation direction.

  In the state shown in FIG. 9, the synchronizer key 14 is urged by the spring 15 in the direction away from the center line 10 a (radially outward), and the protrusion 14 a is fitted in the groove 51 d of the sleeve 50. .

  As described above, the synchromesh mechanism 10 has a length that allows the sleeve 50 to contact the synchronizer ring 60 and the synchronizer ring 70 at the same time. Therefore, when switching from the gear 20 to the gear 30, the sleeve 50 and the gear 50 are synchronized. 20 until the synchronizer ring 70 is pushed directly or indirectly by the sleeve 50 to come into contact with the tapered cone surface 32 of the gear 30 to generate a frictional force. At the time of switching to 20, the engagement between the sleeve 50 and the gear 20 is released, and then the synchronizer ring 60 is pushed directly or indirectly by the sleeve 50 to contact the tapered cone surface 22 of the gear 20 to generate a frictional force. It takes less time than before. Therefore, the synchromesh mechanism 10 can suppress the torque interruption at the time of gear switching compared to the related art.

  In the synchromesh mechanism 10, when the sleeve 50 moves from the state of meshing with the gear 30 to the gear 20 side, at least before the contact with the gear 30 is released, the synchronizer indirectly through the synchronizer key 14. The length is such that the synchronizer ring 60 is brought into contact with the tapered cone surface 22 of the gear 20 by pushing the ring 60. With this configuration, when the synchromesh mechanism 10 is switched from the state in which the sleeve 50 is engaged with the gear 30 to the state in which it is engaged with the gear 20, at least before the contact between the sleeve 50 and the gear 30 is released, the sleeve 50 indirectly Since the synchronizer ring 60 is pressed to bring the synchronizer ring 60 into contact with the tapered cone surface 22 of the gear 20 to generate a frictional force, torque loss at the time of switching from the gear 30 to the gear 20 is suppressed, and a feeling of idling is suppressed. Can do. In the synchromesh mechanism 10, when the sleeve 50 moves from the state of meshing with the gear 20 to the gear 30 side, at least before the contact with the gear 20 is released, the sleeve 50 is indirectly synchronized with the synchronizer key 14. The length is such that the synchronizer ring 70 is brought into contact with the tapered cone surface 32 of the gear 30 by pushing the ring 70. Therefore, the synchromesh mechanism 10 can suppress running out of torque even at the time of switching from the gear 20 to the gear 30, and can suppress the feeling of idling.

  In the synchromesh mechanism 10, the sleeve 50 is the maximum length that occurs only when the contact with the gear 30 and the contact with the synchronizer ring 60 are different when moving from the state of meshing with the gear 30 toward the gear 20. It is. With this configuration, the synchromesh mechanism 10 allows the synchronizer ring 60 to be used by the sleeve 50 immediately after the contact between the sleeve 50 and the gear 30 is released when the sleeve 50 is switched from a state in which the sleeve 50 is engaged with the gear 30 to a state in which the sleeve 50 is engaged with the gear 20. Is directly pressed to bring the synchronizer ring 60 into contact with the tapered cone surface 22 of the gear 20 to generate a frictional force, thereby suppressing torque loss when switching from the gear 30 to the gear 20 and suppressing idling. . In the synchromesh mechanism 10, the sleeve 50 is the maximum length that occurs only when the contact with the gear 20 and the contact with the synchronizer ring 70 are different when moving from the state of meshing with the gear 20 toward the gear 30. It is. Therefore, the synchromesh mechanism 10 can suppress running out of torque even at the time of switching from the gear 20 to the gear 30, and can suppress the feeling of idling.

  When the sleeve 50 moves to the gear 20 side from the state of meshing with the gear 30, the sleeve 50 has a length that occurs only when the contact with the gear 30 and the contact with the synchronizer ring 60 are different from each other. And the maximum length that occurs only when the contact with the synchronizer ring 60 is different. Similarly, when the sleeve 50 moves to the gear 30 side from a state in which it engages with the gear 20, the sleeve 50 has a length that occurs only when the contact with the gear 20 and the contact with the synchronizer ring 70 are different. 20 may not be the maximum length that occurs only when the contact with the synchronizer ring 70 and the contact with the synchronizer ring 70 are different.

  When the sleeve 50 moves in the gear 20 side direction, the synchromesh mechanism 10 causes the chamfer 33a of the gear 30 to contact the sleeve 50 by the relative rotation between the gear 30 and the sleeve 50, thereby moving the sleeve 50 in the gear 20 side direction. Therefore, the operation force for bringing the synchronizer ring 60 into contact with the tapered cone surface 22 of the gear 20 indirectly via the synchronizer key 14 by the sleeve 50 can be reduced. Similarly, when the sleeve 50 moves in the gear 30 side direction, the synchromesh mechanism 10 indirectly contacts the synchronizer ring 70 with the tapered cone surface 32 of the gear 30 via the synchronizer key 14. It is possible to reduce the operating force for making it happen.

  As shown in FIG. 10, the transmission mechanism 4 has the gear 20 and the gear 30 from the power source 2 of the vehicle 1 when it is necessary to cut off the transmission of power from the power source 2 of the vehicle 1 to the gear 20 and the gear 30. A power transmission automatic shut-off mechanism 90 that automatically shuts off the power transmission up to may be provided. For example, the speed change mechanism 4 may be used for an automatic transmission (AT) such as a dual clutch transmission (DCT), or may be used for a semi-automatic transmission such as an automated manual (AMT).

  The transmission mechanism 4 may be a manual transmission (MT).

  The speed change mechanism 4 may include a gear other than the gear 20 and the gear 30. When the synchromesh mechanism 10 switches the continuous shift speeds among the shift speeds of the transmission mechanism 4, the transmission mechanism 4 suppresses torque interruption by the synchromesh mechanism 10 at the time of switching these continuous shift speeds. The gear position can be switched smoothly.

(Second Embodiment)
First, the structure of the speed change mechanism including the synchromesh mechanism according to the second embodiment will be described.

  FIG. 11 is a cross-sectional view of transmission mechanism 400 according to the present embodiment when in the first speed state. FIG. 12 is a skeleton diagram of the speed change mechanism 400.

  The speed change mechanism 400 shown in FIGS. 11 and 12 is similar to the speed change mechanism 4 (see FIG. 1) according to the first embodiment and the vehicle 1 (see FIG. 1) according to the first embodiment. Installed in similar vehicles.

  The transmission mechanism 400 is a four-speed transmission mechanism for FF (front engine / front drive system).

  The speed change mechanism 400 includes an input shaft 411 connected to a power source of the vehicle, a gear 412 that is rotatably supported by the input shaft 411 and realizes first and third speeds, and is rotatably supported by the input shaft 411. A gear 413 for realizing the second speed and the fourth speed, a synchromesh mechanism 414 for switching the connection state of the input shaft 411, the gear 412, and the gear 413, and a shift fork 415 for operating the synchromesh mechanism 414. I have.

  When the power source of the vehicle is a motor, the input shaft 411 can be connected to different motors at both ends. The input shaft 411 includes a hub 411a having a spline formed on the outer periphery.

  The gear 412 includes a dog gear 412a having a spline formed on the outer periphery. The dog gear 412a also has a tapered cone surface 412b formed on the outer periphery.

  The gear 413 includes a dog gear 413a having a spline formed on the outer periphery. The dog gear 413a also has a tapered cone surface 413b formed on the outer periphery.

  The synchromesh mechanism 414 is an inertia lock type synchromesh mechanism. The synchromesh mechanism 414 is disposed between the hub 411a and the dog gear 412a, and a spline is formed on the outer periphery to contact the tapered cone surface 412b to generate a frictional force, and between the hub 411a and the dog gear 413a. And a synchronizer ring 414b that generates a frictional force by contacting the tapered cone surface 413b and a synchronizer key 414c disposed between the synchronizer ring 414a and the synchronizer ring 414b. Mesh with the spline of the hub 411a, the spline of the dog gear 412a, the spline of the dog gear 413a, the spline of the synchronizer ring 414a, and the spline of the synchronizer ring 414b. A sleeve 414d which splines are formed on the inner peripheral possible, and a hub 411a, a gear 412 and gear 413. The sleeve 414d is movable in the extending direction of the input shaft 411, and an annular groove extending in the circumferential direction is formed on the outer periphery so that the shift fork 415 is fitted. Similarly to the sleeve 50 (see FIG. 2) of the synchromesh mechanism 10 (see FIG. 2) according to the first embodiment, the sleeve 414d has a length that allows simultaneous contact with the synchronizer ring 414a and the synchronizer ring 414b. That's it. Similarly to the sleeve 50 of the synchromesh mechanism 10 according to the first embodiment, the sleeve 414d is released from contact with at least the gear 412 when moving from the state of meshing with the gear 412 to the gear 413 side. When the synchronizer ring 414b is indirectly pressed through the synchronizer key 414c from the front to bring the synchronizer ring 414b into contact with the tapered cone surface 413b and the gear 413 is engaged with the gear 413, at least the gear is moved. The length may be such that the synchronizer ring 414a is brought into contact with the tapered cone surface 412b by indirectly pushing the synchronizer ring 414a via the synchronizer key 414c before the contact with the 413 is released. Similarly to the sleeve 50 of the synchromesh mechanism 10 according to the first embodiment, the sleeve 414d contacts with the gear 412 and synchronizer ring when moving from the state of meshing with the gear 412 to the gear 413 side. This occurs only when the contact with 414b is different, and when moving from the state of meshing with the gear 413 to the gear 412 side, the contact with the gear 413 and the contact with the synchronizer ring 414a occur only at different times. That's it.

  The speed change mechanism 400 includes a counter shaft 416 arranged in parallel to the input shaft 411, a sub shaft 417 rotatably supported by the counter shaft 416, a third shaft and a sub shaft 417 rotatably supported by the sub shaft 417. A gear 418 for realizing the fourth speed, a gear 419 for rotatably supporting the first and second speeds supported by the counter shaft 416, a counter shaft 416, a sub shaft 417, a gear 418 and a gear 419 A power switching device 420 for switching the connection state and shift forks 421 and 422 for operating the power switching device 420 are provided.

  The counter shaft 416 includes a dog gear 416a having a spline formed on the outer periphery, and a gear 416b that meshes with the gear 413 to realize the second speed and the fourth speed.

  The sub-shaft 417 includes a dog gear 417a having a spline formed on the outer periphery, and a gear 417b that meshes with the gear 412 to realize the first speed and the third speed.

  The gear 418 includes a dog gear 418a having a spline formed on the outer periphery.

  The gear 419 includes a dog gear 419a having a spline formed on the outer periphery.

  The power switching device 420 includes a sleeve 420a in which a spline that can mesh with a spline of the dog gear 416a, a spline of the dog gear 417a, and a spline of the dog gear 418a, a spline of the dog gear 416a, a spline of the dog gear 417a, In addition, a sleeve 420b in which a spline capable of meshing with the spline of the dog gear 419a is formed on the inner periphery, a dog gear 416a, a dog gear 417a, a dog gear 418a, and a dog gear 419a are provided. The sleeve 420a is movable in the extending direction of the counter shaft 416, and an annular groove extending in the circumferential direction is formed on the outer periphery so that the shift fork 421 is fitted. The sleeve 420b is movable in the extending direction of the countershaft 416, and an annular groove extending in the circumferential direction is formed on the outer periphery so that the shift fork 422 is fitted.

  The speed change mechanism 400 includes drive shafts 423 and 424 as output shafts that are arranged in parallel to the counter shaft 416 and transmit power to the vehicle wheel side, and a differential gear 425 that connects the output shafts 423 and 424. I have.

  The differential gear 425 includes a gear 425a that meshes with the gear 418 and realizes the third speed and the fourth speed, and a gear 425b that meshes with the gear 419 and realizes the first speed and the second speed.

  The speed change mechanism 400 is a power transmission system that transmits power transmitted from the power source side to the wheel side, a power transmission system 410a that can switch between first and third speeds, and power transmission that can switch between second and fourth speeds. And a system 410b. The synchromesh mechanism 414 is a clutch that switches a power transmission system in which power is transmitted from the power source side of the power transmission systems 410a and 410b and power is transmitted to the wheel side.

  FIG. 13 is a block diagram of a control system of the speed change mechanism 400.

  As shown in FIG. 13, the speed change mechanism 400 includes various sensors 401 that detect the state of the vehicle, and shift forks 415 (see FIG. 11) and 421 (see FIG. 11) in the extending direction of the input shaft 411 (see FIG. 11). 11) and 422 (see FIG. 11), and a control unit 403 that controls the operation of the actuator 402 according to the detection result of the sensor 401.

  Examples of the sensor 401 include a sensor that detects the accelerator pedal opening degree of the vehicle, a sensor that detects the vehicle speed of the vehicle, and the like.

  The control unit 403 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) storing programs and various data, and a RAM (Random Access Memory) used as a work area of the CPU. Yes. The CPU executes a program stored in the ROM.

  Next, the operation of the speed change mechanism 400 will be described.

  First, the states of the synchromesh mechanism 414 and the power switching device 420 when the speed change mechanism 400 is at each speed stage will be described.

  When the speed change mechanism 400 is in the first speed state, the synchromesh mechanism 414 connects the sleeve 414d to the hub 411a and the dog gear 412a as shown in FIG. In the power switching device 420, the sleeve 420a is connected to the dog gears 416a and 417a, and the sleeve 420b is connected to the dog gears 416a and 419a. Accordingly, the power input to the input shaft 411 is transmitted from the gears 412, 417, 419 and 425 a in order and output from the drive shafts 423 and 424.

  When the speed change mechanism 400 is in the second speed state, as shown in FIG. 14, the synchromesh mechanism 414 connects the sleeve 414d to the hub 411a and the dog gear 413a. In the power switching device 420, the sleeve 420a is connected to the dog gears 416a and 417a, and the sleeve 420b is connected to the dog gears 416a and 419a. Therefore, the power input to the input shaft 411 is transmitted in order through the gears 413, 416b, 419, 425a and output from the drive shafts 423 and 424.

  When the speed change mechanism 400 is in the third speed state, the synchromesh mechanism 414 connects the sleeve 414d to the hub 411a and the dog gear 412a as shown in FIG. In the power switching device 420, the sleeve 420a is connected to the dog gears 417a and 418a, and the sleeve 420b is connected to the dog gears 416a and 419a. Therefore, the power input to the input shaft 411 is transmitted from the gears 412, 417, 418, and 425 a in order and output from the drive shafts 423 and 424.

  When the speed change mechanism 400 is in the fourth speed state, as shown in FIG. 16, the synchromesh mechanism 414 connects the sleeve 414d to the hub 411a and the dog gear 413a. In the power switching device 420, the sleeve 420a is connected to the dog gears 417a and 418a, and the sleeve 420b is connected to the dog gears 416a and 417a. Therefore, the power input to the input shaft 411 is transmitted from the drive shafts 423 and 424 in order through the gears 413, 416b, 418, and 425a.

  Next, the operation of the speed change mechanism 400 when switching from the first speed to the second speed will be described.

  When the speed change mechanism 400 is in the first speed state shown in FIG. 11, the control unit 403 switches from the first speed to the second speed based on information such as the accelerator pedal opening and the vehicle speed detected by the sensor 401, for example. If it is determined that there is, the actuator 402 is operated to connect the sleeve 414d to the hub 411a and the dog gear 413a in the synchromesh mechanism 414. As a result, the speed change mechanism 400 enters the second speed state shown in FIG.

  Next, the operation of the speed change mechanism 400 when switching from the second speed to the third speed will be described.

  When the speed change mechanism 400 is in the second speed state shown in FIG. 14, the control unit 403 switches from the second speed to the third speed based on information such as the accelerator pedal opening degree and the vehicle speed detected by the sensor 401, for example. When it is determined that there is, the actuator 402 is operated to connect the sleeve 420a to the dog gears 417a and 418a in the power switching device 420 as shown in FIG.

  Next, the control unit 403 operates the actuator 402 to connect the sleeve 414d to the hub 411a and the dog gear 412a in the synchromesh mechanism 414. As a result, the speed change mechanism 400 enters the third speed state shown in FIG.

  Next, the operation of the speed change mechanism 400 when switching from the third speed to the fourth speed will be described.

  When the speed change mechanism 400 is in the third speed state shown in FIG. 15, the control unit 403 switches from the third speed to the fourth speed based on information such as the accelerator pedal opening and the vehicle speed detected by the sensor 401, for example. If it is determined that there is, the actuator 402 is operated to connect the sleeve 420b to the dog gears 416a and 417a in the power switching device 420 as shown in FIG.

  Next, the control unit 403 operates the actuator 402 to connect the sleeve 414d to the hub 411a and the dog gear 413a in the synchromesh mechanism 414. As a result, the speed change mechanism 400 enters the fourth speed state shown in FIG.

  As described above, when the speed change mechanism 400 switches from the second speed to the third speed, the power transmission system transmits the power transmitted from the power source side to the wheel side after switching to the third speed state in the power transmission system 410a. Is switched from the power transmission system 410b to the power transmission system 410a. When the speed change mechanism 400 is switched from the third speed to the fourth speed, the power transmission system that transmits the power transmitted from the power source side to the wheel side after switching to the fourth speed state in the power transmission system 410b, The transmission system 410a is switched to the power transmission system 410b.

  In the above, the operation of the speed change mechanism 400 at the time of upshifting has been described. The speed change mechanism 400 is similarly operated at the time of shift down to switch from 4th speed to 3rd speed, at the time of shift down to switch from 3rd speed to 2nd speed, and at the time of shift down to switch from 2nd speed to 1st speed. In the power transmission system to which the switch belongs, the power switching device 420 switches to the shift destination gear, and then the synchromesh mechanism 414 switches to the power transmission system to which the switch gear belongs.

  The synchromesh mechanism 414 can obtain the same effects as the synchromesh mechanism 10 (see FIG. 2) according to the first embodiment.

  Since the speed change mechanism 400 suppresses the torque interruption by the synchromesh mechanism 414 when switching the continuous speed stages, the speed stages can be switched smoothly.

  When switching the gear position, the transmission mechanism 400 switches to the power transmission system to which the switching destination gear position belongs, after switching to the switching destination gear stage by the power switching device 420 and then to the power transmission system to which the switching gear position belongs. Since it is switched by the synchromesh mechanism 414, the gear position can be switched instantaneously. Therefore, the speed change mechanism 400 is less likely to cause a torque shortage at the time of shift speed change, and can suppress the feeling of idling felt by the driver of the vehicle.

  In the speed change mechanism 400, since the mechanism for switching the power transmission systems 410a and 410b is not a disk clutch but the synchromesh mechanism 414, the power transmission system is compared with a configuration in which the mechanism for switching the power transmission systems 410a and 410b is a disk clutch. The diameter of the rotating part of the mechanism for switching between 410a and 410b can be reduced. Therefore, the speed change mechanism 400 can reduce the moment of inertia that must be synchronized when the power transmission systems 410a and 410b are switched. Therefore, the speed change mechanism 400 does not need to provide the synchromesh mechanism in the power switching device 420.

  In the above, a four-speed transmission mechanism has been described as the transmission mechanism 400. However, the speed change mechanism 400 may be a speed change mechanism other than the fourth speed. Here, by adding a countershaft, the speed change mechanism 400 can increase the number of shift stages while suppressing the overall length of the speed change mechanism 400 in the extending direction of the input shaft 411.

  In the above description, a transmission mechanism for FF is described as the transmission mechanism 400. However, the speed change mechanism 400 may be a speed change mechanism other than for FF, such as an FR (front engine / rear drive type) speed change mechanism, and may also be applied to a speed change mechanism other than a vehicle. it can.

2 Power source 4 Transmission mechanism 10 Synchromesh mechanism 11 Shaft 20 Gear (first gear, second gear)
22 Tapered cone surface (first conical surface, second conical surface)
23a Chamfa (inclined surface)
30 gears (first gear, second gear)
32 Tapered cone surface (first conical surface, second conical surface)
33a Chamfa (inclined surface)
50 Sleeve 60, 70 Synchronizer ring (first synchronizer ring, second synchronizer ring)
400 Transmission mechanism 411 Shaft 412 Gear (first gear, second gear)
412b Tapered cone surface (first conical surface, second conical surface)
413 gear (first gear, second gear)
413b Tapered cone surface (first conical surface, second conical surface)
414 Synchromesh mechanism 414a, 414b Synchronizer ring (first synchronizer ring, second synchronizer ring)
414d sleeve

Claims (5)

A shaft,
A first gear that is rotatably supported by the shaft and has a first conical surface;
A second gear that is rotatably supported by the shaft, has a different speed step from the first gear, and has a second conical surface;
A sleeve that rotates integrally with the shaft and that is supported by the shaft so as to be movable in the extending direction of the shaft, and switches between meshing with the first gear and the second gear;
A first synchronizer ring that facilitates synchronization of the first gear and the sleeve by a frictional force generated between the first conical surface and the first conical surface;
A second synchronizer ring for facilitating synchronization of the second gear and the sleeve by a frictional force generated between the second conical surface and
The synchromesh mechanism is characterized in that the sleeve has a length capable of simultaneously contacting the first synchronizer ring and the second synchronizer ring.   When the sleeve moves from the state of meshing with the second gear toward the first gear, at least before the contact with the second gear is released, the sleeve synchronizes the first synchronizer ring. The synchromesh mechanism according to claim 1, wherein the synchromesh mechanism has a length that pushes the first synchronizer ring in contact with the first conical surface.   When the sleeve moves from the state of meshing with the second gear toward the first gear, the contact with the second gear and the contact with the first synchronizer ring are different. 3. The synchromesh mechanism according to claim 1, wherein the synchromesh mechanism is a maximum length that occurs only when the synchromesh mechanism is used.   The second gear contacts the sleeve by relative rotation between the second gear and the sleeve when the sleeve moves from the state of meshing with the second gear to the first gear side. The synchromesh mechanism according to any one of claims 1 to 3, wherein an inclined surface is formed to push the sleeve toward the first gear. A transmission mechanism comprising the synchromesh mechanism according to any one of claims 1 to 4,
The synchromesh mechanism is configured to switch a continuous gear among the gears of the transmission mechanism.

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