JPH04125318A - Synchronizing mechanism - Google Patents

Abstract

PURPOSE:To make smooth chamfer shifting action possible by forming a sleeve chamfer into double or single slant face chamfer, forming the single slant face chamfer in a direction where a clutch gear chamfer is decelerated, and protruding it forward than the double slant face chamfer. CONSTITUTION:At the time of shifting up, a chamfer face 9b on a back side in the rotational direction of the double slant face sleeve chamfer 9A of a synchro sleeve 1 abuts on a chamfer face 11a on a front side in the rotational direction of a ring chamfer 11A, and reaction torque therefore acts to the chamfer face 9b in the direction of rotation and to the chamfer face 11a in the direction of reverse rotation to cause a difference in the rotation between a synchrosleeve 1 and a clutch gear 2. When the synchrosleeve 1 moves farther, the chamfer face 9c of the single slant face sleeve chamfer 9B faces a rear side in its rotational direction, and the chamfer face 10c of a clutch gear chamfer 10B faces a front side in its rotational direction, and the clutch gear chamfers 10B are therefore pushed apart in a direction not opposed to a differential rotation for the smooth abutting of the single slant face sleeve chamfer 9B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a synchronizer mechanism suitable for use in an automobile transmission, and particularly to a so-called Warner type synchro mechanism that performs synchronization through a synchro ring.

[Prior Art] Transmissions installed in automobiles and the like are provided with synchro mechanisms, and currently, so-called Warner type synchro mechanisms are the mainstream in passenger cars.

Such a Warner type synchronization mechanism is shown in Fig. 7(a).
As shown in (b), it includes a synchronizer sleeve (or synchronizer sleeve) 1, a clutch gear 2, and a synchronizer ring (or synchronizer ring) 3. In some of the drawings, the synchro sleeve 1 is shown as S, the clutch gear 2 is shown as C, and the synchro ring is shown as R.

The synchronizer sleeve 1 is provided on the outer periphery of the clutch hub (or synchronizer hub) 4 in serration connection with the clutch hub 4, and is configured to rotate integrally with the clutch hub 4 while sliding on the clutch hub 4 in the axial direction. . Furthermore, the synchro sleeve 1 can be slid by a driver's operation through a shift fork (not shown) or the like.

Further, the clutch gear 2 is provided coaxially and in series next to the clutch hub 4 and the synchro sleeve 1, and meshes with a gear (not shown Q) provided on a countershaft (not shown) or the like during riding. It is integrally equipped with a gear 5.

The synchro ring 3 is provided at the end of the synchro sleeve 1 on the clutch gear 2 side so that it can rotate together with the synchro sleeve 1 while being allowed an appropriate amount of play in the rotational direction, and when the synchro sleeve 1 is slid and driven. synchronizes both members 1 and 2 when they are coupled to clutch gear 2.

Further, as shown in FIGS. 7(a) and 7(b), teeth 16, 17, and 18 are provided on the inner circumference of the synchro sleeve 1 and on the outer circumferences of the clutch gear 2 and synchro ring 3, respectively. When the synchro sleeve 1 slides, the teeth 16 of the synchro sleeve 1 mesh with the teeth 17 and 18 of the clutch gear 2 and the synchro ring 3 so as to hang there.

The above-mentioned play amount (index deviation amount) of the synchro ring 3 with respect to the synchro sleeve 1 in the rotational direction is as shown by the solid line in FIG. The neutral position is the state in which the tooth is located in the center, and it can be shifted forward and backward by approximately half the tooth width (see the chain line in FIG. 8).

In order to achieve such a constant shift, for example, the key on the synchro sleeve 1 side is placed in the key groove (shift piece groove) formed on the synchro ring 3 side with a play of about one tooth width, as described above. It is fitted. In addition, the key on the synchro sleeve 1 side and the keyway on the synchro ring 3 side, when the teeth 18 of the synchro ring 3 are in the neutral position,
The key is arranged so as to be located at the center of the keyway in the rotational direction.

Then, the synchro sleeve 1 and the synchro ring 3,
For example, when rotating in the directions shown by the arrows ωS and ωR in FIG. 8, the synchro ring 3 is accelerated first during upshifting, so the teeth 18 of the synchro ring 3 are rotated as shown by the reference numeral 18'. Tooth 1 of synchro sleeve 1
Tooth 1 of the front synchro sleeve 1 in advance of 6
It comes to a position where it can come into contact with 6. In addition, at the time of downshifting, the synchro ring 3 is decelerated first, so the teeth 18 of the synchro ring 3 move backward relative to the teeth 16 of the synchro sleeve 1, as shown by the reference numeral 18, and the synchro ring 3 at the rear moves backward. It comes to a position where it can come into contact with the teeth 16 of No. 1.

In order to smoothly engage each tooth, the teeth 16 of the synchro sleeve 1 are provided with teeth 16 at the longitudinal ends of the teeth 16.
A sleeve chamfer 19A is formed as a double-sided chamfer consisting of two inclined surfaces (chamfer surfaces) 19a and 19b that are symmetrical about the center line of the clutch gear 2. Two chamfer surfaces 20a, 2 symmetrical with respect to the center line of the tooth 17
A clutch gear chamfer 20A of a double-sided chamfer made of chamfer 0b is formed, and two chamfer surfaces 21a symmetrical with respect to the center line of the tooth 18 are also formed at the longitudinal end of the tooth 18 of the synchro ring 3.

Ring chamfer 2 of double slope chamfer consisting of 21b
1A is formed.

Further, in an adjacent portion between the clutch gear 2 and the synchro ring 3, the clutch gear 2 is formed with a tapered outer circumferential surface 2a, and the synchro ring 3 is formed with a tapered inner circumferential surface 3a, so that the synchro ring 3 is on the side of the clutch gear 2. When moving to , these tapered surfaces 2a and 3a come into contact and become rotationally synchronized.

With this configuration, when the synchro sleeve 1 is driven from the neutral state to the clutch gear 2 side, the synchro ring 3 is first moved toward the clutch gear 2 side by a synchro key (not shown), and the taper of the synchro ring 3 is Side 3
a comes into contact with the tapered surface 2a of the clutch gear 2. As the synchro sleeve 1 moves, the synchro ring 3 is pressed, and the synchro ring 3 is pressed.
The tapered surface 3a of the clutch gear 2 comes into strong pressure contact with the tapered surface 2a of the clutch gear 2. This pressing force acts as a synchronizing force that rotationally synchronizes the synchronizing ring 3 with the clutch gear 2.

Further, when the synchro sleeve l moves toward the clutch gear 2, the sleeve chamfer 19A comes into contact with the ring chamfer 21A, as shown in FIG. 9(a), and the synchro sleeve 1 presses the synchro ring 3. The teeth 16 of the sleeve 1 engage the teeth 18 of the synchro ring 3. At this time, the synchro ring 3 is rotationally synchronized with the clutch gear 2, and the synchro sleeve 1, which rotates integrally with the synchro ring 3, is also synchronized with the clutch gear 2.
The rotation is synchronized with.

When the synchro sleeve 1 moves further after being rotationally synchronized in this way, as shown in FIG.
1117, and the connection between synchro sleeve 1 and clutch gear 2 is completed.

[Problems to be Solved by the Invention] By the way, in the conventional synchronizing mechanism described above, when the synchronizing sleeve 1 engages with the clutch gear 2, a two-stage motion occurs in the shift operation force. Such a two-stage motion becomes particularly large during upshifting, and there is a problem in that it worsens the shift feeling during upshifting.

That is, before the shift operation, the rotation speed ωS of the synchro sleeve 1 is smaller than the rotation speed ωC of the clutch gear 2, but when the upshift operation is started, as shown in FIG. The tapered surface 3a of the synchro ring 3 and the tapered surface 2a of the clutch gear 2
The operating force (synchronized force) as shown by code a1 is applied between
In response to F, the synchro sleeve 1 becomes synchronized with the clutch gear 2, and the rotational speed ω of the synchro sleeve 1 increases.
S becomes equal to the rotational speed ωC of the clutch gear 2.

In this way, while the synchro sleeve 1 is rotationally synchronized with the clutch gear 2, the sleeve chamfer 19A abuts the ring chamfer 21A. As shown in FIG. 9(a), the slope 19b of the sleeve chamfer 19A on the rear side in the rotational direction comes into contact with the slope 21a on the front side in the rotational direction of the ring chamfer 21A. Become.

Therefore, when the sleeve chamfer 19A pushes the ring chamfer 21A while decelerating it (the amount of ring deceleration pushing is in hours), it receives the operating force F as shown by the symbol a2, and as shown in FIG. 9(a). Synchro sleeve 1 as shown
In this case, torque TI acts on the acceleration side as a pushing force, and torque TI acts on the synchro ring 3 on the deceleration side as a reaction torque to this torque TI. Therefore, the rotation of the synchro sleeve 1 is accelerated and the rotation of the synchro ring 3 and the clutch gear 2 is decelerated by the ring deceleration push, so that the rotation speed ωS of the synchro sleeve 1 becomes
The rotational speed ωC of the clutch gear 2 becomes larger, and as shown in FIG. 9(b), the differential rotation Δω (=ωS−ωC)
occurs.

In addition, friction torque Tf acts on the clutch gear 2 on the synchronized side in the deceleration direction, and torsional vibration also occurs on the synchronized side synchro sleeve 1 side, so the above-mentioned differential rotation Δω is promoted. Become so.

Therefore, after the synchro sleeve 1 is rotationally synchronized with the clutch gear 2, the rotation speed ωS of the synchro sleeve 1 is accelerated, while the rotation speed ωC of the clutch gear 2 is decelerated, and the differential rotation Δω becomes large. See the characteristic line Δωi in Figure 9(b).

As shown in FIG. 10, when the sleeve chamfer 19A pushes the clutch gear chamfer 2OA apart and engages in a state where the rotational speed ωS of the synchro sleeve 1 is higher than the rotational speed ωC of the clutch gear 2, as shown in FIG. The slope 19a on the front side in the rotational direction of the sleeve chamfer 19A comes into contact with the slope 20b on the rear side in the rotational direction of the clutch gear chamfer 2OA, and the differential rotation Δω rapidly decreases to 0 [Fig. 9 ( b), see characteristic line Δωd].

Therefore, the synchro sleeve 1 comes into contact with and meshes with the clutch gear 2 at a relative speed of the differential rotation Δω, and a large operating force is required when meshing with the clutch gear 2.

Therefore, the operating force (shift operating force) F of the synchro sleeve 1 changes as shown in FIG. 11 in response to time Tc, and when the synchro sleeve 1 engages with the synchro ring 3 (see time t1) - After the time decreases to almost 0, the push amount to the clutch gear chamfer 20A is sign a due to engagement.
As shown in 3, the clutch gear chamfer 20A increases rapidly.
(see time t2), it decreases to 0 again, and during this time tc, the operating force F fluctuates greatly.
This shift shock results in a step motion and causes a worsening of the shift feeling.

Note that during downshifting, contrary to the above, the rotational speed ωS of the synchro sleeve 1 becomes smaller than the rotational speed ωC of the clutch gear 2 due to ring pushing apart, but a friction torque T acts on the clutch gear 2 on the deceleration side. Therefore, the difference between the rotational speed ωS of the synchro sleeve 1 and the rotational speed ωC of the clutch gear 2 is alleviated, the two-stage motion of the operating force becomes gentle, and no deterioration of the special shift feeling occurs.

The present invention was devised in view of such problems, and
It is an object of the present invention to provide a synchronizer mechanism that can improve shift feeling by reducing the two-step motion of operating force that occurs during upshifting in the synchro mechanism.

[Means for Solving the Problems] Therefore, the synchro mechanism of the present invention includes a synchro sleeve that moves in the axial direction, a clutch gear that can be engaged with the synchro sleeve, and a synchro mechanism provided in a transmission. A synchro ring is provided between the sleeve and the clutch gear to synchronize the rotations of the synchro sleeve when the synchro sleeve moves to the clutch gear, and a sleeve chamfer is formed at the longitudinal end of the teeth of the synchro sleeve. At the same time, a clutch gear chamfer and a ring chamfer that can come into contact with the sleeve chamfer are formed at the longitudinal ends of the teeth of the clutch gear and the teeth of the synchro ring, respectively, and the sleeve chamfer has an inner slope. The shaft includes a chamfer and a single-sided chamfer, the single-sided chamfer is formed in a direction capable of decelerating the clutch gear chamfer, and is arranged so as to protrude more forward than the inner slope chamfer, The ring chamfer is characterized in that it is formed corresponding to the position where the inner slope chamfer of the sleeve chamfer is formed.

[Function] In the synchro mechanism of the present invention described above, when the synchro sleeve moves from the neutral position to the clutch gear side, the synchro ring is pressed toward the clutch gear side, and the synchro sleeve and synchro ring are rotationally synchronized with the clutch gear. go. Then, while the inner slope chamfer of the sleeve chamfer pushes the ring chamfer apart, the teeth of the synchro sleeve mesh with the teeth of the synchro ring. When this is an upshift, when the synchro sleeve pushes the ring chamfer apart, the synchro sleeve is accelerated and the ring chamfer and clutch gear are decelerated, creating a differential rotation between the synchro sleeve and the clutch gear. Afterwards, among the sleeve chamfers, a single slope chamfer which is arranged to decelerate the clutch gear chamfer and to be formed in a longitudinal direction and to protrude more forward than the inner slope chamfer comes into contact with the clutch gear chamfer, and this clutch Since the gear chamfer is pushed to the deceleration side,
Even if the differential rotation between the synchro sleeve and the clutch gear is large, the shock caused by the synchro chamfer pushing the clutch gear chamfer is small.

[Example] Hereinafter, a synchronizer mechanism as an example of the present invention will be explained with reference to the drawings. Fig. 1 is a configuration diagram schematically showing the shape of each tooth in plan view (a diagram of each chunk in the neutral state of the synchro sleeve). Diagram showing positional relationship), 2nd
4 are schematic plan views of each tooth sequentially showing the movement state of the synchro sleeve, FIG. 5 is a graph showing the effect, and FIG. 6 is a plan view showing a modification of the ring chamfer.

This synchronization mechanism is also a Warner type synchronization mechanism,
Its overall structure is as explained in the prior art section with reference to FIG. It is composed of:

These synchro sleeves 1. The overall structure and arrangement of each of the clutch gear 2 and the synchro ring 3 are almost the same as those described above, so a description thereof will be omitted here, but in this synchro mechanism, the synchro sleeve 1. clutch gear 2
The shape and arrangement of each tooth of the synchro ring 3 are different from those of the conventional synchro ring.

In other words, as shown in FIG. 1, when the teeth 6, 7 and 8 formed on the inner periphery of the synchro sleeve 1 and the outer peripheries of the clutch gear 2 and synchro ring 3 are shown unfolded on the same cylindrical surface, The result will be as shown in Figure 1.

As shown in the figure, the teeth 6 of the synchro sleeve 1 are arranged almost in the same way as in the conventional example, but the teeth 6 of the synchro sleeve 1 are arranged in two pairs that are symmetrical on the center line of the teeth 6.
The sleeve chamfer 6A is provided with a sleeve chamfer 9A having two chamfer surfaces 9a and 9b, which is a double-sided chamfer almost similar to the conventional example.

It consists of a sleeve chamfer 9B, which is a single-sided chamfer consisting of only one chamfer surface 9c, and a sleeve chamfer 6B. In this embodiment, the teeth 6B having the single slope sleeve chamfer 9B are provided two each between the teeth 6S having the double slope sleeve chamfer 9A, but the arrangement is not limited to this.

Further, the 5-slope sleeve chamfer 9B protrudes forward (toward the clutch gear 2 side) than the double-slope sleeve chamfer 9A, and is located earlier than the double-slope sleeve chamfer 9A.
It can come into contact with a clutch gear chamfer IOB, which will be described later.

The teeth 7 of the clutch gear 2 are arranged almost in the same way as in the conventional example, but the chamfers (clutch gear chamfers) 10B of the teeth 7 of the clutch gear 2 are all constituted by a chamfer surface 10c having a single slope. It has a chamfer on one side.

The single-sided sleeve chamfer 9B that comes into contact with the clutch gear chamfer 1oB first is constituted by a chamfer surface 9c facing rearward with respect to the rotational direction, and the clutch gear chamfer IOB has a chamfered surface facing forward with respect to the rotational direction. 10c. As a result, the single slope sleeve chamfer 9B comes into contact with the clutch gear chamfer 10B, and this clutch gear chamfer 10
When B is pushed apart, due to the reaction force of the contact surfaces of both,
One side slope sleeve chamfer 9B has rotation direction (acceleration side)
A force is applied to the clutch gear chamfer IOH in a direction opposite to the rotational direction (deceleration side).

Further, the teeth 8 of the synchro ring 3 are formed only at locations corresponding to the teeth 6A forming the double-slope sleeve chamfer 9A, and are not formed at locations corresponding to the teeth 6B forming the single-slope sleeve chamfer 9B. Not yet.

Note that the ring chamfer IIA formed on the tooth 8 of this synchro ring 3 has two chamfer surfaces 11a, l that are approximately symmetrical on the left and right sides with respect to the center line of the tooth 8, as in the conventional example.
It is formed as a double-sided chamfer consisting of lb.

The synchro mechanism as an embodiment of the present invention is configured as described above, and its operation will be explained using an example of upshifting. When the synchro sleeve 1 is driven from the neutral position toward the clutch gear 2, The synchro ring 3 is pressed toward the clutch gear 2 via a synchro key (not shown), and the synchro sleep 1 and the synchro ring 3 become rotationally synchronized with the clutch gear 2.

As shown in FIG.
The ring chamfer IIA is pushed apart, and the teeth 6A and 6B of the synchro sleeve 1 mesh with the teeth 8 of the synchro ring 3.

Since the shift is now up, the chamfer surface 9b on the rear side in the rotational direction of the double slope sleeve chamfer 9A is the chamfer surface 11a on the front side in the rotational direction of the ring chamfer 11A.
in contact with the chamfer surface 9 of the sleeve chamfer 9A.
b receives a reaction torque T in the rotational direction, and the chamfer surface 11a of the ring chamfer IIA receives a reaction torque T in a direction opposite to the rotational direction.

Therefore, the synchro sleeve 1 is accelerated and its rotational speed ωS increases, whereas the ring chamfer 3 and the clutch gear 2 are decelerated, and the rotational speed ωC of the clutch gear 2 is decreased.

Therefore, a differential rotation occurs between the synchro sleeve 1 and the clutch gear 2.

In addition to this, friction torque Tf acts on the clutch gear 2 on the synchronized side in the direction of deceleration.
Torsional vibration also occurs on the synchronous sleep 1 side. The differential rotation described above is facilitated.

Subsequently, when the synchro sleeve 1 moves further, the third
As shown in the figure, first, the one-sided sleeve chamfer 9B of the sleeve chamfers contacts the clutch gear chamfer IOB and pushes the clutch gear chamfer IOB apart.

At this time, the chamfer surface 9c of the single-slope sleeve chamfer 9B faces toward the rear with respect to the rotation direction, and the chamfer surface 1°C of the clutch gear chamfer IOH faces toward the front with respect to the rotation direction, so that the chamfer surface 9c When you push the chamfer surface 10c apart, sleep chamfer surface 9B
The chamfer surface 9c of the clutch gear chamfer IOB moves forward while rotating relative to the chamfer surface 10c in the rotation direction thereof.

At this time, the rotational speed ωS of the synchro sleeve 1 is larger than the rotational speed ωC of the clutch gear 2, resulting in a rotational difference Δω [Refer to the characteristic line Δω1 in FIG. 9(b). Since the sleeve chamfer 9B pushes the clutch gear chamfer IOB apart in a direction that cannot resist this differential rotation, the one-slope sleeve chamfer 9B comes into contact with the clutch gear chamfer IOB smoothly. In other words, the characteristic line Δωd in FIG. 9(b) is the characteristic line Δωd.
The connection becomes relatively smooth with respect to ωi. Therefore, as shown in FIG. 5, the operating force F required when the synchro sleeve 1 engages with the clutch gear 2 is
(see figure) to Fc', and the operating time also decreases from tc to tc', and the operating resistance is significantly reduced as indicated by symbol a3' compared to the conventional example, indicated by symbol a3. 2-stage motion is reduced.

As a result, it becomes possible to perform a smooth shift operation during upshifting, which has the effect of significantly improving shift feeling.

In addition, in this embodiment, the clutch gear chamfer IOB
are all single-sided chamfers, but this is adapted to the single-sided sleeve chamfer 9B. A part of the clutch gear chamfer IOB may be a single-sided chamfer and the other part a double-sided chamfer, or all It is also conceivable to use the clutch gear chamfer IOB as a double-sided chamfer.

Furthermore, as shown in FIG. 6, the ring chamfer 11 is
It is also conceivable that the chamfer 11C is asymmetrical on both sides. In other words, when shifting up, the sleeve chamfer 9
The chamfer surface lid on the acceleration side (front side in the rotational direction) of the ring chamfer 11C that comes into contact with A is formed to be smaller than the other chamfer surface lie.

As a result, during upshifting, the chamfer surface 9b on the rear side in the rotational direction of the double slope sleeve chamfer 9A becomes the chamfer surface li on the front side in the rotational direction of the ring chamfer IIA.
d, the contact area and contact time are small, so the reaction torque T that the chamfer surface 9b of the sleeve chamfer 9A receives in the rotational direction is also small, causing acceleration of the synchro sleeve 1, ring chamfer 3, etc. clutch gear 2
As a result, the differential rotation Δω generated between the synchro sleeve 1 and the clutch gear 2 is reduced, and the effect of preventing the two-stage motion during the above-mentioned operation becomes even more reliable.

[Effects of the Invention] As detailed above, according to the synchronization mechanism of the present invention,
A synchro mechanism provided in a transmission includes a synchro sleeve that moves in an axial direction, a clutch gear that can be engaged with the synchro sleeve, and a clutch gear of the synchro sleeve that is interposed between the synchro sleeve and the clutch gear. A synchronizer ring is provided to synchronize the rotations of these teeth when the clutch gear moves to the shaft, and a sleeve chamfer is formed at the longitudinal end of the teeth of the synchro sleeve, and a sleeve chamfer is formed at the longitudinal end of the teeth of the clutch gear and the synchro ring. A clutch gear chamfer and a ring chamfer that can come into contact with the sleeve chamfer are respectively formed at the longitudinal ends of the teeth, the sleeve chamfer is configured with a double-sided chamfer and a single-sided chamfer, and the single-sided chamfer is configured to The ring chamfer is formed in a direction capable of decelerating the clutch gear chamfer and is disposed so as to protrude more forward than the both sloped chamfers, so that the ring chamfer corresponds to the position where the both sloped chamfers of the sleeve chamfer are formed. Due to the structure that is formed by
This has the effect of reducing the two-stage motion of the operating force during upshifting, allowing smoother shifting, and greatly improving shift feeling.

[Brief explanation of drawings]

Figures 1 to 5 show a synchronizer mechanism as an embodiment of the present invention, and Figure 1 is a configuration diagram schematically showing the shape of each tooth in plan view (the position of each chunk in the neutral state of the synchro sleeve). Figures 2 to 4 are plan view schematic diagrams of each tooth showing the movement state of the synchro sleeve, Figure 5 is a graph showing its effect, and Figure 6 is a deformation of the ring chamfer. FIG. 7 is a plan view showing an example, and FIGS. 7 to 11 show a conventional synchronizing mechanism.
Fig. 7(a) is a sectional view of the main part showing the shape of each tooth of the synchronizing mechanism [Fig. Fig. 8 is a schematic plan view of each tooth of the synchro sleeve and synchro ring showing the amount of phase shift of the synchro ring, and Fig. 9 (,) shows the contact of the sleeve chamfer to the ring chamfer. FIG. 9(b) is a schematic plan view of each tooth showing the contact state, and FIG.
FIG. 0 is a schematic plan view of each tooth showing the contact state of the sleeve chamfer to the clutch gear chamfer, and FIG. 11 is a graph showing the problem. 1- Synchronizer sleeve (or synchronizer sleeve)
, 2-clutch gear, 3-synchronizer ring (or synchronizer ring), 6.6A, 6B-teeth of synchro sleeve, 7-teeth of clutch gear, 8-teeth of synchro ring, 9A-sleeve chamfer (double slope sleeve chamfer) ), 9B-Sleeve chamfer (single slope sleeve chamfer) 10B-Clutch gear chamfer, IIA, 1
1C-ring chamfer, 9a, 9b, 9c, 10c,
lla, llb, lld, 1ie = chamfered surface.

Claims (1)

[Claims] A synchro mechanism provided in a transmission includes a synchro sleeve that moves in an axial direction, a clutch gear that can be engaged with the synchro sleeve, and a clutch gear of the synchro sleeve that is interposed between the synchro sleeve and the clutch gear. A synchronizer ring is provided to synchronize the rotations of these teeth when the clutch gear moves to the shaft, and a sleeve chamfer is formed at the longitudinal end of the teeth of the synchro sleeve, and a sleeve chamfer is formed at the longitudinal end of the teeth of the clutch gear and the synchro ring. A clutch gear chamfer and a ring chamfer that can come into contact with the sleeve chamfer are respectively formed at the longitudinal ends of the teeth, the sleeve chamfer is configured with a double-sided chamfer and a single-sided chamfer, and the single-sided chamfer is configured to The ring chamfer is formed in a direction capable of decelerating the clutch gear chamfer and is disposed so as to protrude more forward than the both sloped chamfers, so that the ring chamfer corresponds to the position where the both sloped chamfers of the sleeve chamfer are formed. A synchronizing mechanism characterized by being formed.