JPH0318058B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a synchronizing device for a transmission.

(Prior Art) Conventionally, inertia lock type synchronizers, particularly Borg-Warner type synchronizers, have been widely used. That is, this is a device that generates friction torque in the cone clutch due to the difference in circumferential speed, and uses that friction torque to achieve synchronization.

In such devices, as the dynamic performance of vehicles has recently improved, there has been a demand for increased synchronization capacity in order to improve operability. For example, the following four measures can be considered in order to increase the synchronization capacity.

(1) Increase the cone diameter.

(2) Reduce the cone angle.

(3) Increase the friction coefficient of the tapered friction surface.

(4) Pressing thrust of tapered friction surface (sleeve thrust) Make it bigger.

However, no matter which of the above measures is used, it is difficult to sufficiently increase the synchronous capacity.

That is, in the case of the measure described in item (1), it is difficult to increase the cone diameter due to the problem of dimensional constraints of the transmission. In reality, the limit is a size increase of a few percent, and the accompanying increase in synchronization capacity only reaches a few percent, so the effect obtained is extremely low considering the amount of effort.

In the case of the countermeasure in item (2), by setting the cone angle small, a "biting phenomenon" occurs between the synchronizer cone and the synchronizer ring, and the synchronizer ring separates from the synchronizer cone after synchronization. It disappears. In other words, the synchronizer ring is fixed to the synchro cone as if it were press-fitted. In the range of cone angles generally used in practical use, if the angle has already been set at the lower limit, it is impossible to reduce the angle any further.

In the case of the countermeasure in item (3), it is possible to provide a high-friction base material on the tapered friction surface, but in that case, the "biting phenomenon" will occur as in the case of item (2) above. The cone angle must be made slightly larger. Therefore, an increase in the overall synchronous capacity does not correspond to an increase in the coefficient of friction.

In the case of the measure described in item (4), there are problems with the durability of the synchronizer ring and deterioration of operability, so the sleeve thrust cannot be made excessively large.

(Objective of the Invention) The object of the first, second, and third inventions of the present application is to dramatically increase the synchronizing capacity of the synchronizing device, and to reduce the sticking phenomenon so that the clutch hub and the synchro cone can quickly engage. It is to do so.

(Means for Achieving the Object) In order to increase the synchronization capacity and reduce the biting phenomenon, the first invention (claim 1)
(invention of claim 2), second invention (invention of claim 2), third invention (invention of claim 4)
A cone clutch is formed by forming a tapered friction surface on the inner periphery of a synchronizer ring that rotates integrally with the clutch hub, and making the tapered friction surface face the outer periphery tapered friction surface of a synchronizer cone. The main part of the invention is that at least one pair of intermediate cones is arranged between the cones to form a multi-plate conical crunch structure.

Furthermore, in order to further eliminate the jamming phenomenon by reducing the residual torque generated on the friction surface of the intermediate cone: In the first invention, a synchro cone is attached to the intermediate cone that rotates integrally with the clutch hub and the clutch hub engaging portion. In the second invention, the engagement portion between the synchro cone and the intermediate cone, which rotates integrally with the synchro cone, is provided with play in the circumferential direction equivalent to approximately half or more of the tooth thickness of the dog gear. In the third invention, the radial thickness of the intermediate cone that rotates integrally with the synchro cone is such that the inner and outer circumferential surfaces of the intermediate cone become thicker toward the small diameter end. The taper angles are different.

(Embodiment to which the first and second inventions are applied) Fig. 1 shows an example in which a synchronizer to which the first and second inventions are applied is used in a transmission of a small truck. is rotatably fitted to the transmission main shaft 1 via a bearing 3, and the clutch hub 5 is spline-fitted to the main shaft 1 so as to rotate integrally with the main shaft 1. The inner teeth 31 of the sleeve 6 are spline-fitted to the outer teeth of the clutch hub 5 so as to be slidable in the axial direction, so that the sleeve 6 and the clutch hub 5 always rotate together. A shift arm 10 is engaged with the outer circumferential annular groove 8 of the sleeve 6, and the shift arm 10 is fixed to a shift rod 11. The shift rod 11 is interlocked and connected to a shift lever (not shown), etc., and can be moved in the axial direction. be done. The input gear 2 meshes with a counter gear of a counter shaft (not shown).

A multi-plate cone-type clutch is provided between the input gear 2 and the clutch hub 5, which includes a synchronizer cone 12, a synchronizer ring (block ring) 13, a strut 17, an intermediate cone, etc.

The synchro cone 12 is spline-fitted to the boss portion of the input gear 2 so that it always rotates integrally with the input gear 2. A tapered friction surface 22 whose diameter becomes smaller toward the clutch hub 5 is formed on the outer periphery of the cylindrical portion of the synchro cone 12 that protrudes toward the clutch hub 5. On the other hand, the synchronizer ring 13 includes a plurality of notches 30, into which the struts 17 protrude with play in the circumferential direction. A tapered friction surface 26 that faces the tapered friction surface 22 of the synchronizer cone 12 is formed on the inner peripheral surface of the synchronizer ring 13 .

As shown in FIG. 5, a friction cone 20 and a separator cone 21 are disposed as intermediate cones between the friction surfaces 22 and 26 in order from the inside, and both intermediate cones 20 and 21 are made of steel (e.g. The friction cone 20 is made of structural steel, and a friction material 32 with a high coefficient of friction is pasted on both the inner and outer surfaces of the inner friction cone 20.

A sleeve-side chamfer part 31a is formed at the end of the internal teeth 31 of the sleeve on the arrow F side, and a sleeve-side chamfer part 31a is formed at the outer peripheral end of the synchronizer ring 13 and the outer peripheral end of the synchro cone 12. Chamfer part 27 that can be freely engaged
and dog teeth 24 are formed, respectively. A dog tooth side chamfer portion 24a is formed at the end of the dog tooth 24 on the opposite side to the arrow F side.

The strut 17 is attached to the clutch hub 5 shown in FIG.
The notch 15 is fitted into a notch 15 at the outer peripheral end of the tooth, and the notch 15 is formed deeper than the outer peripheral tooth. The strut 17 shown in FIG. 5 has an outward protrusion 17a, is biased in the outer circumferential direction by a pair of springs 18, and is in contact with the inner circumferential surface of the sleeve 6. A recess 6a is formed on the inner circumferential surface of the inner tooth 31 of the sleeve 6 and engages with the protrusion 17a of the strut 17.

In FIG. 2 showing an exploded perspective view of the intermediate cone, circular friction cone engagement holes 29 are formed in the clutch hub 5 at intervals in the circumferential direction, while the small diameter end of the friction cone 20 There is a protrusion 20a protruding toward the clutch hub 5 side.
A plurality of projections 20a are formed at intervals in the circumferential direction, and each projection 20a corresponds to each engagement hole 2 of the clutch hub 5.
9, thereby causing friction cone 20
is adapted to rotate integrally with the hub 5.

As a measure against residual torque during indexing, the protrusion 20a and the engagement hole 29 engage with each other with a play d in the circumferential direction of the clutch hub 5, and the size of the play d is as shown in FIG. The size is approximately half or more of the tooth thickness l of the dog tooth 24 (d≧
l/2).

At the end of the separate cone 21 on the large diameter side (arrow F side), a plurality of protrusions 21a protruding toward the arrow F side are formed at intervals in the circumferential direction. A plurality of engagement holes 25 are formed at intervals, and each engagement hole 25
The synchro cone 12 and the separator cone 21 rotate integrally by engaging the protrusion 21a with the synchro cone 12 and the separator cone 21.

This separator cone 21 and synchro cone 1
2 is also provided with means for dealing with residual torque. That is, the protrusion 21a is formed in a wedge shape, and both end surfaces 21 in the circumferential direction
b is an inclined surface that becomes narrower between both end surfaces as it goes toward the arrow F side. Furthermore, both end surfaces 2 of the engagement hole 25
5b also has an inclined surface that becomes narrower between both end surfaces as it goes toward the arrow F side.

(Function) When the input gear 2 in FIG. 1 is rotating and the main shaft 1 and hub 5 are not rotating, the shift arm 10 and shift rod 11
When the strut 17 starts moving in the direction of arrow F, the strut 17 also starts moving in the direction of arrow F together with the sleeve 6. When the strut 17 comes into contact with the edge of the notch 30 in the direction of arrow F as shown in FIG. , this escape force is synchronizer ring 13
acts as an initial load, and the sleeve 6 and ring 13 are positioned so that the sleeve-side channel portion 31a and the channel portion 27 of the synchronizer ring 13 face each other. The movement of the sleeve 6 is prevented by the synchronizer ring 13, and this blocking force acts as a friction torque on the cone clutch. Frictional torque is generated by three frictional parts. That is, the friction portion between the inner peripheral friction surface 26 of the synchronizer ring 13 and the outer peripheral surface of the separator cone 21, the friction portion between the inner peripheral surface of the separator cone 21 and the outer peripheral surface of the friction cone 20, and the synchronizer cone 12. Tapered friction surface 2
2 and the inner peripheral surface of the friction cone 20. Therefore, the synchronous capacity becomes extremely large.

Also, the friction material 32 is only in the friction cone 20.
Therefore, at the beginning of the generation of friction torque, friction starts to develop between the inner circumferential friction surface 27 of the ring 13 and the outer circumferential surface of the separator cone 21, which are metal-to-metal contacts, as in the conventional case, and then the friction cone Moving on to 20 frictions. Therefore, under synchronization does not occur.

At the time when the synchronization is completed, the state is as shown in FIGS. 3 and 5, and the sleeve side channel portion 31a and the ring side channel portion 27 are in contact with each other as described above. At this point, the relative speed between the synchro cone 12 and the synchronizer ring 13 is lost, and by further moving the sleeve 6 in the F direction, the sleeve side channel part 31a is moved to the dog tooth side channel part as shown in FIGS. 4 and 6. It comes into contact with 24a.

By further moving the sleeve 6 in the direction of the arrow F from the states shown in FIGS. 4 and 6, the sleeve 6 is shifted in the direction of the arrow E (index direction) relative to the dog teeth 24, and insert. However, when the sleeve 6 is inserted between the dog teeth 24 from the state shown in FIGS. 4 and 6 as described above, that is, when indexing is performed, the friction torque due to the action of the strut 17 etc. is temporarily eliminated, but in reality In this case, residual torque is generated at the abutting portion between the friction cone 20 and the separator cone 21 due to viscous resistance of the material, etc., and both intermediate cones 20 and 21 are integrated, so that the residual torque is generated. prevents the sleeve 6 from shifting in the direction of arrow E, making it difficult for the sleeve 6 to index with the dog teeth 24. To deal with such residual torque, the engagement hole 29 and the protrusion 2 in FIG.
Since the sleeve 6 has a play d in the circumferential direction of 1/2 or more, the sleeve 6 can be shifted to the position between the dog teeth 24 almost unhindered by residual torque. Further, the protrusion 21a of the separator cone 21 and the engagement hole 25 of the synchro cone 1 are arranged on inclined surfaces 21b, 25.
Due to the butt-butting structure of a, when the dog teeth 24 and the sleeve 6 index, a force that tries to protrude in the opposite direction of the arrow F is generated due to the wedge effect, and the residual torque is almost eliminated. let (Embodiment to which the third invention is applied) FIG. 7 shows an embodiment to which the third invention is applied, and similarly to the embodiments of the first and second inventions, a friction cone 20 and a separator cone 21 are used as intermediate cones. A multi-plate conical clutch structure is adopted, and by devising the cross-sectional shape of the separator cone 21, the residual torque is completely eliminated.

That is, the radially outer surface and the inner surface are arranged so that the thickness W of the end 21C on the small diameter side (opposite to the arrow F side) of the separator cone 21 is thicker than the thickness of the end on the large diameter side. The cone angles of the surfaces are different. Specifically, the cone angle of the outer peripheral surface is made gentler than the cone angle of the inner peripheral surface.

The rest of the structure is the same as the embodiments of the first and second inventions, but as shown in FIG. About dog teeth 2
The tooth thickness l may be less than 1/2 of the tooth thickness l of the separator cone 21, and the protrusion 21a of the separator cone 21 and the engagement hole 25 of the synchro cone 12 do not need to be engaged with each other on inclined surfaces.

According to the structure shown in FIG. 7, the separator cone 21
As shown in FIG. 8, the contact pressure on the inner circumferential surface increases toward the small diameter end 21c. Therefore, as shown in the upper half of Fig. 4, after synchronization, the dog tooth 2
Even if residual torque is generated between the friction cone 20 and the separator cone 21 that disturbs indexing when the chamfer part 24a of the sleeve 6 and the chamfer part 31a of the sleeve 6 are in contact with each other, as shown in FIG. separator cone 21
Due to the unbalance of pressure applied to the friction cone 20, the friction cone 20 tends to jump out to the side where the pressure is greater, that is, the small diameter end 21c side.
The residual torque between the separator cone 21 and the separator cone 21 can be significantly reduced, making indexing operations easier.

(Other embodiments) (1) The embodiments shown in FIGS. 1 to 6 show examples having the structures of the first invention and the second invention, but of course only the first invention regarding play d is used. Even in structures with
A synchronization device having a structure including only the invention may be used.

(2) A synchronizing device may be configured by combining the first invention and the third invention, or by combining the second invention and the third invention, or it may include all of the first, second, and third inventions. A synchronizer may also be configured.

(3) Two or more pairs of intermediate cones may be provided. In that case, the separator cone that engages with the synchro cone and the friction cone that engages with the clutch hub must be arranged alternately.

(Effects of the Invention) As explained above, the first, second, and third inventions of the present application form a tapered friction surface on the inner circumference of the synchronizer ring that rotates integrally with the clutch hub,
A cone clutch is formed by arranging the tapered friction surface to face the outer peripheral tapered friction surface of the synchro cone, and at least one pair of intermediate cones is arranged between the synchronizer ring and the synchro cone to form a multi-plate conical clutch structure. Since the main part is
By increasing the friction surface, the synchronous capacity can be dramatically increased, which also greatly improves the operability of the transmission.

Furthermore, since there is no need to reduce the cone angle below the allowable limit or to increase the cone diameter, it is possible to reduce the biting phenomenon and maintain compactness.

Further, in the first invention, the intermediate cone (friction cone 2) rotates integrally with the clutch hub 5.
0) and the clutch hub 5 is given circumferential play d equivalent to approximately half or more of the tooth thickness l of the dog gear, so even if residual torque is generated on the friction surface of the intermediate cone after synchronization is completed, However, since the sleeve 6 and the dog teeth 24 have a degree of freedom in the circumferential direction by the amount of play d described above, the clutch hub 5 can be relatively moved in the index direction regardless of the residual torque, making it easy to operate. Your sexuality will further improve.

In the second invention, since the engaging portion of the synchro cone 12 and the intermediate cone (separator cone 21) that rotates integrally with the synchro cone 12 has a structure in which inclined surfaces abut against each other, even if the synchronization is completed, the friction of the intermediate cone Even if residual torque is generated on the surface, the wedge effect generates a force that pushes the separator cone 21 toward the cone thrust release side (opposite to the arrow F side in Figure 4), thereby eliminating the residual torque. This further improves operability.

In the third invention, the inner peripheral surface and the outer peripheral surface of the separator cone 21 are arranged such that the radial thickness of the intermediate cone (separator cone 21) that rotates integrally with the synchro cone 12 becomes thicker toward the small diameter end. Because the taper angles of the , residual torque can be eliminated, and operability is further improved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a synchronizer to which the first and second inventions of the present application are applied, Fig. 2 is an exploded perspective view of an intermediate cone, and the upper half of Fig. 3 is a of Fig. 1 during synchronization. -a cross section enlarged development view, lower half part is b-b cross section enlarged development view of Fig. 1, upper half part of Fig. 4 is aa cross section enlarged development view of Fig. 1 immediately before the index, lower half part is Fig. 1 is an enlarged cross-sectional view taken along line bb in Fig. 1, Fig. 5 is a - sectional view in Fig. 3, Fig. 6 is a - sectional view in Fig. 4, and Fig. 7 is a vertical cross-section of the synchronizing device to which the third invention is applied. The enlarged surface view, FIG. 8, is a partial cross-sectional view of the separator cone showing surface pressure distribution. 5...Clutch hub, 12...Synchro cone, 13...Synchronizer ring, 20,2
1...Friction cone, separator cone (intermediate cone), 22, 26...Friction surface, 20a...
...Protrusion, 21a...Protrusion, 21b...Slope, 2
4... Dog tooth, 25... Engagement hole, 25a... Inclined surface, 29... Engagement hole.

Claims (1)

[Claims] 1. A cone clutch is constructed by forming a tapered friction surface on the inner periphery of a synchronizer ring that rotates integrally with the clutch hub, and making the tapered friction surface face the outer periphery tapered friction surface of the synchro cone. At least one pair of intermediate cones is disposed between the synchronizer ring and the synchro cone to form a multi-plate conical clutch structure, and at the engagement portion between the intermediate cone, which rotates integrally with the clutch hub, and the clutch hub,
A synchronizing device for a transmission, characterized in that it provides play in the circumferential direction equivalent to approximately half or more of the dog gear tooth thickness of a synchro cone. 2 A tapered friction surface is formed on the inner periphery of a synchronizer ring that rotates integrally with the clutch hub, and the tapered friction surface is opposed to the outer periphery tapered friction surface of the synchro cone to form a cone clutch, and the synchronizer ring and synchro cone are At least one pair of intermediate cones is arranged between them to form a multi-plate conical clutch structure, and the engaging portion between the intermediate cone, which rotates integrally with the synchro cone, and the synchro cone has a structure in which inclined surfaces abut against each other. A synchronizing device for a transmission characterized by: 3. According to claim 2, the engagement portion between the intermediate cone, which rotates integrally with the clutch hub, and the clutch hub is provided with play in the circumferential direction corresponding to approximately half or more of the dog gear tooth thickness of the synchro cone. transmission synchronizer. 4 A tapered friction surface is formed on the inner periphery of a synchronizer ring that rotates integrally with the clutch hub, and the tapered friction surface is opposed to the outer periphery tapered friction surface of the synchro cone to form a cone clutch, and the synchronizer ring and synchro cone are At least one pair of intermediate cones is arranged between them to form a multi-plate conical clutch structure, and the thickness of the intermediate cone, which rotates integrally with the synchro cone, in the radial direction becomes thicker toward the smaller diameter end. A synchronizing device for a transmission, characterized in that the inner circumferential surface and the outer circumferential surface of an intermediate cone have different taper angles. 5. According to claim 4, the engagement portion between the intermediate cone, which rotates integrally with the clutch hub, and the clutch hub is provided with play in the circumferential direction corresponding to approximately half or more of the dog gear tooth thickness of the synchro cone. transmission synchronizer. 6. The synchronizing device for a transmission according to claim 5 or 6, wherein the engagement portion between the intermediate cone that rotates integrally with the synchro cone and the synchro cone has a structure in which inclined surfaces abut against each other.