JPH0517435B2 - - Google Patents

Description

Detailed Description of the Invention A. Purpose of the Invention (1) Industrial Field of Application The present invention relates to a multi-stage forward gear train established through a synchronization mechanism, and a reverse gear train established by sliding engagement of reverse idle gears. The present invention relates to a change device for a vehicle transmission equipped with a gear train, particularly to an improvement in a change device that prevents gear squeal when a reverse idle gear is shifted to establish a reverse gear train.

(2) Prior art In the above transmission, even if the clutch is first disengaged to establish the reverse gear train, the input shaft, which had been rotated by the engine until then, continues to rotate due to inertia, albeit for a short time. Therefore, if the reverse idle gear is shifted, that is, slidingly engages, during its inertial rotation, an abnormal noise called gear squeal is generated, causing discomfort to the occupants.

A change device designed to eliminate such inconveniences is disclosed in Japanese Utility Model Application Publication No. 59-68848.

The disclosed apparatus includes a reverse shift fork for shifting a reverse idle gear from its rest position to a reverse gear train establishment position and a forward shift fork for establishing one forward gear train. is provided with a resilient mechanism capable of shifting the shift fork in the direction of establishing the one forward gear train in response to the reverse idle gear being operated from the rest position to the reverse gear train establishing position, the resilient mechanism comprising: It is configured to deform and lose the shifting function for the forward shift fork when receiving an operating load of a predetermined value or more, and when the forward shift fork is shifted by this elastic mechanism, a synchronizing mechanism is applied to the synchronizing mechanism corresponding to the shift fork. The shift piece of the shift fork is brought into contact with the bottom of the concave portion of the interlock plate facing it, and the inertial rotation of the input shaft is stopped by the synchronizing action of the synchronizing mechanism just before the reverse gear train is established. Or it is made to be weakened.

(3) Problems to be Solved by the Invention In the conventional device described above, the triggering mechanism is activated not only when the reverse shift fork moves forward, but also when the reverse shift fork moves backward. The operation of the popping mechanism during movement has the drawback of making the forward movement heavy and giving a poor operational feeling.

The present invention has been made in view of these circumstances, and when the reverse shift fork moves forward, the forward shift fork is shifted by a prescribed small stroke, and the inertial rotation of the input shaft can be accurately suppressed. Moreover, it is an object of the present invention to provide the above-mentioned change device that can easily perform forward movement of the reverse shift fork while avoiding unnecessary resistance when the reverse shift fork moves backward.

B. Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a reverse shift fork for shifting a reverse idle gear from its rest position to a reverse gear train establishment position; A fixed cam is provided on one side of the forward shift fork to establish one forward gear train, and a movable cam that is free to rotate in only one direction is provided on the other side. , while the fork moves from the rest position of the reverse idle gear to the position on the verge of establishing the reverse gear, the forward shift fork cooperates with the fixed cam and the synchronizing mechanism corresponding thereto has a predetermined value sufficient to cause the corresponding synchronizing mechanism to exert only a synchronizing action. It only shifts a small stroke, but when the reverse shift fork is working,
It is characterized by being arranged so as to rotate in one direction so as not to resist the fixed cam.

(2) Effect When the reverse shift fork is moved forward in order to establish the reverse gear train, first, while the reverse shift fork is operating from the rest position of the reverse idle gear to the position on the verge of establishing the reverse gear train, the Since the forward shift fork of one forward gear train is shifted by a predetermined small stroke by the cooperation of the cam and the movable cam, only a synchronous action is produced in the synchronization mechanism of the forward gear train, and the inertial rotation of the input shaft is accurately controlled. Can be suppressed. Therefore, by further forward movement of the reverse shift fork, the reverse idle gear can be smoothly shifted to the position where the reverse gear train is established without causing gear squeal.

Next, when the reverse shift fork is moved back in order to release the establishment of the reverse gear train, the movable cam is rotated in one direction by the fixed cam, that is, it performs a load avoidance action, so that the forward shift fork This allows the reverse shift fork to move back easily without encountering any resistance.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an automobile power unit equipped with a transmission M having four forward speeds and one reverse speed to which the present invention is applied. In the figure, the output of engine E is transmitted from its crankshaft to clutch C to transmission M.
and the left and right wheel drive shafts S, sequentially through the differential device D.
S' and drive them.

Between the input and output shafts 11i and 11o supported in parallel to each other by the transmission case 10 of the transmission M,
In order from the engine E side, 1st forward gear train G ₁ , reverse gear train Gr, 2nd forward gear train G ₂ to 4th gear train G ₄
are provided in parallel. The 1st to 4th speed gear trains G ₁ to _{G 4} are
Input gears 1i to 4i fixed to input shaft 11i
and output gears 1o to 4 which are rotatably supported by the output shaft 11o and are constantly meshed with the corresponding input gears.
between the 1st speed output gear 1o and the 2nd speed output gear 2o, there is a 1st-2nd speed synchronization mechanism 7 which can alternately connect these to the output shaft 11o, and a 3rd speed output gear train 3o and 4 A 3rd and 4th speed synchronizing mechanism 8 is provided between the speed output gears 4o, which can alternately connect these gears to the output shaft 11o.

Thus, the 1st speed output gear 1o or the 2nd speed output gear 2o is connected to the output shaft 11 via the 1st-2nd speed synchronization mechanism 7.
o, a first speed gear train _G1 or a second speed gear train _G2 is established. In addition, 3-4 speed synchronization mechanism 8
via 3rd speed output gear 3o or 4th speed output gear 4
o is connected to the output shaft 11o, the 3rd speed gear train G ₃
Or the 4th speed gear train G ₄ is established. The gear train thus established transmits the output torque of the engine E from the input shaft 11i to the output shaft 11o at a predetermined gear ratio.

The torque transmitted to the output shaft 11o is transmitted to the differential gear D via the final reduction gear train Gf.

The reverse gear train Gr includes an input gear 5i fixed to an input shaft 11i, and an input gear 5i opposite to the input gear 5i.
- The output gear 5o carved in the sliding sleeve 7a of the second-speed synchronization mechanism 7 is slidably and rotatably supported by the intermediate shaft 14 arranged parallel to the input and output shafts 11i and 11o. and input above, output gear 5
It consists of a reverse idle gear 6 that can move between a differential position in which it meshes with gears i and 5o at the same time and a rest position in which it disengages from them. When the reverse idle gear 6 is moved to the operating position where it meshes with the input and output gears 11i and 11o, a reverse gear train Gr is established, and the torque of the input shaft 11i is transferred to the input gears 5i and 5i.
Reverse idle gear 6, output gears 5o and 1-
It can be transmitted to the output shaft 11o via the second speed synchronization mechanism 7 and reversed.

Next, a change device for establishing the first to fourth speed gear trains _G1 to _G4 and the reverse gear train Gr will be explained with reference to FIGS. 2 to 8.

First, Figure 2 shows the operation pattern of the change lever of the change device, where N is the neutral position,
is the 1st gear position, is the 2nd gear position, is the 3rd gear position, is the 4th gear position, and R is the reverse drive position.

In FIGS. 3 and 4, a change rod 17 interlocked with the change lever is slidably and rotatably supported by the mission case 10. As shown in FIGS. An operating arm 18 fixed to the tip of the change rod 17 is connected to a driven arm 19a formed integrally with the shift arm 19. The shift arm 19 is rotatably and slidably supported by a support shaft 20 extending in a direction perpendicular to the change rod 17, and when the change lever is operated in the select direction A in FIG. 2, it slides due to the rotation of the change rod 17. and when operated in the shift direction B, the change rod 17 is slid and rotated.

The support shaft 20 is supported by a support plate 21 fixed to the mission case 10.

Three shift pieces 22a, 23a, 24a are located on the trajectory of the tip of the shift arm 19 as it slides.
will be placed. When the shift arm 19 selects the - position of the change lever, the engagement groove 22b of the upper shift piece 22a in FIG.
, and when the change lever is in the N position, that is, the - position is selected, the center shift piece 23
a, and when the change lever is in the R position, the lower shift piece 24
It is adapted to engage with the engagement groove 24b of a.

The upper shift piece 22a engages with the sliding sleeve 7a of the 1-2 speed synchronization mechanism 7.
In addition, the central shift piece 22a engages with the sliding sleeve 8a of the synchronizing mechanism 8 for 3rd and 4th speeds.
3, the lower shift piece 24a is integrally connected to the reverse shift member 24, respectively.

As shown in FIG. 3, the 1st-2nd speed shift fork 22 and the 3rd-4th speed shift fork 23 are supported by a fork shaft 27 whose both ends are fitted into a pair of support holes 25 and 26 of the transmission case 10. Each is slidably supported on the Therefore, shift arm 1
9 to the upper shift piece 22a and rotate it left and right as shown in FIG. 3, the 1st-2nd speed shift fork 2
2 to the left and right on the fork shaft 27,
- the synchronizer 7 for second gear can be activated to the position where the first and second gear trains G ₁ , G ₂ are established; In addition, if the shift arm 19 is engaged with the center shift piece 22a and rotated left and right, the 3-4 speed shift fork 23
slide left and right on the fork shaft 27, and
The fourth speed synchronizer 8 can be operated to the position where the third and fourth speed gear trains G ₃ and G ₄ are established.

1-2 speed shift fork 22 and fork shaft 2
7, the shift fork 22 is connected between 1-2
A first detent device 28 for moderately holding the speed synchronizing mechanism 7 at the rest position, the first speed gear train _G1 at the established position, and the second speed gear train _G2 at the established position.
will be provided. Also 3-4 speed shift fork 23
and the fork shaft 27, the shift fork 23 is placed in three positions: the rest position of the 3rd-4th speed synchronization mechanism 8, the established position of the 3rd speed gear train _G3 , and the established position of the 4th speed gear train _G4 . A second detent device 29 is provided for moderately holding the vehicle. Both of these detent devices 28 and 29 are constructed of a known ball-notch type.

A pin 33 that engages with a rotation prevention groove 32 formed in the mission case 10 is fixed to one end of the fork shaft 27 in order to prevent rotation thereof. Further, a holding spring 34 is provided in one of the support holes 25 and 26 of the mission case 10 to press the fork shaft 27 against the end wall of the other support hole. This prevents the fork shaft 27 from freely moving in the support holes 25 and 26, thereby stabilizing the positions of both shift forks 22 and 23.

The reverse shift member 24 is connected to the fork shaft 2.
7 and is fixed to a reverse shift shaft 37 which is supported by slidably fitting both ends into another pair of support holes 35 and 36 of the mission case 10. Further, a support arm 24c is integrally formed on the reverse shift member 24, and this support arm 24c has a sliding groove 43 at its tip engaged with a fixed guide rod 44 parallel to the reverse shift shaft 37. This serves to prevent the rotation of the reverse shift member 24 while allowing it to slide.

Further, the reverse shift member 24 has a drive pin 38 protruding from one side thereof, and this drive pin 38 is connected to a long hole 40 formed in the middle part of the reverse shift fork 39, as shown in FIG. is engaged with. The reverse shift fork 24 is pivotably supported 41 on the support plate 21 and is engaged with an engagement groove 42 formed on the outer periphery of the boss portion of the reverse idle gear 6 .

When the shift arm 19 is engaged with the lower shift piece 24a and rotated to the right in FIG. By swinging the reverse shift fork 39 to the left in FIG. 5, the reverse idle gear 6 can be shifted from the locking position A to the establishment position C of the reverse gear train Gr (see FIG. 5).

Reverse shift shaft 37 and transmission case 10
The reverse shift member 24 is connected between the rest position A of the reverse idle gear 6 and the reverse gear train Gr.
A third detent device 30 is provided for holding the device in the established position C, and this detent device 30 is also constructed in a known ball-and-notch type.

Again in FIGS. 3 and 4, a pair of interlock plates 45, 46 are provided on both sides of the shift arm 19.
will be placed. These interlock plates 45, 46
is fitted to the boss 19b of the shift arm 19 so as to be relatively rotatable, and is also slidably fitted to a rotation stop pin 47 fixed to the support plate 21 in parallel with the support shaft 20. Therefore, the interlock plate 4
5 and 46 can slide on the support shaft 20 together with the shift arm 19, but cannot rotate around the support shaft 20.

However, rotation of the shift arm 19 is allowed.

These interlock plates 45 and 46 have a support shaft 2.
Both ends of a stopper pin 48 parallel to the shift arm 19 are fixed by caulking, and the stopper pin 48 is disposed in a regulating recess 49 provided on one side of the shift arm 19. When the shift arm 19 rotates, the end wall of the regulating recess 49 and the stopper pin 47 come into contact with each other, thereby changing the rotation angle of the shift arm 19, and therefore each shift fork 22, 23 and the shift member 2.
4 shift stroke is regulated.

The interlock plates 45 and 46 are connected to the shift arm 1.
regulating claws 45a facing each other with the tips of 9 in between;
46a, and these regulating claws 45
a, 46a engages with two shift pieces (for example, 22, 24) other than the one shift piece (for example, 23) engaged by the shift arm 19 to prevent malfunction of the two shift pieces. It is something.

The outer surface of one interlock plate 45 and the support plate 2
1, a first return spring 51 is installed. Further, an annular shoulder 20a is formed at the end of the shift arm 19 opposite to the interlock plate 45, and a position regulating plate 53 is formed opposite to the shoulder 20a and the end of the shift arm 19 adjacent to the shoulder 20a. is arranged, and the outer surface of this position regulating plate 53 and the support plate 21
A second return spring 52 is compressed between the two. The set load of the second return spring 52 is the same as that of the first return spring 5.
It is set larger than that of 1.

By the cooperation of the first and second return springs 51 and 52 and the position regulating plate 53, the shift arm Woo is moved to the position corresponding to the N position of the change lever, that is, the shift piece of the 3rd-4th speed shift fork 23. 2
It is constantly biased to the neutral position where it engages with 3a. When the shift arm 19 is slid against the elastic force of the first return spring 51, the arm 19 engages with the shift piece 22a of the 1st-2nd speed shift fork 22, and the arm 19 is moved into the second position. When the arm 19 is slid against the elastic force of the return spring 52, the arm 19 engages with the shift piece 24a of the reverse shift member 24. A fourth detent device 31 that moderates the sliding movement of the shift arm 19 is provided between the shift arm 19 and the support shaft 20.

In addition, in FIG. 3, 50 is the reverse shift member 2.
This is a back clamp switch that performs a closing operation when 4 is activated.

In FIG. 5, reverse shift fork 39
includes a swinging arm 54 that faces the side surface of the 3-4 speed shift fork 23 in the axial direction of the fork shaft 27.
A one-way cam mechanism 70 is constructed between the swing arm 54 and the 3-4 speed shift fork 23.

As shown in FIGS. 6 and 6A, the one-way cam mechanism 70 includes a drive cam 71 as a fixed cam integrally formed on the swing arm 54, and a pivot shaft 73 on the 3-4 speed shift fork 23. A driven cam 72 as a movable cam rotatably attached through the drive cam 71 is provided, and when the swing arm 54 swings due to the shift operation of the reverse shift fork 39, the drive cam 71
moves the driven cam 72 to the specified small stroke L in the direction of establishing the 4th gear train _G4 of the 3rd-4th gear shift fork 23.
It seems like it's only being pushed.

The pushing stroke L of the drive cam 71 with respect to the driven cam 72 is set to be sufficient for the 3rd-4th speed synchronization mechanism 8 to perform a synchronizing action, but not to establish the 4th speed gear train _G4 . be done.

The driven cam 72 has a stopper arm 72a on one side.
The arm 72a is integrally provided with 3-4
It is made to abut on one side of a stopper pin 75 fixed to the speed shift fork 23 so as to be able to separate from it. A return spring 74 is tensioned between the driven cam 72 and the stopper pin 75 and urges the stopper arm 72a in the direction of contact with the stopper pin 75 with a relatively weak spring force. With such a configuration, the swing arm 5 as the reverse shift fork 39 moves forward.
4 in the positive direction a, even if the driven cam 72 is pushed by the drive cam 71, the stopper arm 72a
is brought into contact with the stopper pin 75 and does not rotate, but
When the swing arm 54 swings in the opposite direction b due to the backward movement of the reverse shift fork 39, the driven cam 72 is pushed by the drive cam 72 and rotates around the pivot shaft 73 against the force of the return spring 74. It is supposed to rotate. The driven cam 7 around this pivot shaft 73
The rotation No. 2 is the load avoidance action of the one-way cam mechanism 70.

Therefore, in order to establish the reverse gear train Gr, first disengage the clutch C, then shift the change lever from the R select position to the shift position, and the shift arm 19 operates the reverse shift member 24 to shift the reverse shift fork. 39 to the left in Fig. 5. Then, while the reverse idle gear 6 is shifted by the fork 39 from the rest position A to the position B on the verge of establishment of the reverse gear train Gr, as shown in FIG. 5A, the swing arm 54 swings in the positive direction a. The driving cam 71 pushes the driven cam 72 due to the movement.

In this case, the driven cam 72 is
2a is brought into contact with the stopper pin 75 and cannot rotate, so the driven cam 72 is shifted by a predetermined small stroke L in the direction of establishing the 4th speed gear train _G4 together with the 3rd-4th gear shift fork 23. By obtaining only the synchronizing action of the speed synchronizing mechanism 8, the inertial rotation of the input shaft 11i can be stopped or weakened. Therefore, as the reverse shift fork 39 rotates as described above, the reverse idle gear 6 is moved to the reverse gear train.
By shifting Gr to the established position C, it is possible to smoothly mesh the input and output gears 5i and 5o without causing gear squeal.

In this case, as described above, keeping the fork shaft 27 in a fixed position by the holding spring 34 to stabilize the position of the 3rd-4th speed shift fork 23 is as follows:
3-4 speed shift fork 2 using cams 71 and 72
This is extremely effective in accurately obtaining the prescribed small shift stroke L of No. 3.

Next, in order to release the establishment of the reverse gear train Gr, the reverse shift fork 39 is rotated to the right in FIG. The driven cam 72 is pressed, but in this case, the driven cam 72 rotates around the pivot shaft 73 against the weak force of the return spring 74, as shown by the chain line in FIG. The reverse shift fork 39 can be easily returned to its original position with almost no resistance from the 3-4 speed shift fork 23.

When the reverse shift member 24 is activated, 3-4
In order to allow the movement of the speed shift fork 23 by a prescribed small stroke L in the direction of establishing the fourth speed gear train _G4 , as shown in FIG. A recess 60 is provided on one side of the regulating claw 45a of the interlock plate 45. Therefore, when the 3rd-4th speed shift fork 23 is slightly shifted in the direction of establishing the 4th speed gear train _G4 , a part of the shift piece 23a enters the recess 60, and the regulating pawl of the interlock plate 45 45a can be avoided.

Slopes 61 and 62 are formed at the opposing corners of the shift arm 19 and the portion of the shift piece 23a that enters the recess 60 of the regulating pawl 45a.

Therefore, in order to release the establishment of the reverse gear train Gr,
When the change lever is returned from the R shift position to the N position in FIG. 2, the shift arm 19 first moves the shift piece 24a backward so that the reverse idle gear 6 returns to the rest position A. Then, due to the cooperation of the first and second return springs 51 and 52 and the position regulating plate 53, the shift arm 19 and the interlock plate 45,
46 is returned to the neutral position corresponding to the N position in FIG. 2, but in the process, the slope 61 of the shift arm 19
collides with the slope 62 of the shift piece 23a, allowing the shift piece 23a to return to its original position.

When the shift arm 19 is in the neutral position, the recess 60 of the regulating pawl 45a of the interlock plate 45 is in the 1-
It faces the shift piece 22a of the second speed shift fork 22. Therefore, in order to prevent the shift piece 22a from entering the recess 60, a stopper 64 is integrally provided on the outer surface of the shift piece 22a and projects from the outer surface of the regulating pawl 46a. Therefore, even when the recess 60 faces the shift piece 22a, the contact between the stopper 64 and the outer surface of the regulating pawl 46a prevents the 1st-2nd speed shift fork 22 from moving in the direction of establishing the 2nd speed gear train _G2 . Activation can be prevented.

C. Effects of the Invention As described above, according to the present invention, there is provided a reverse shift fork for shifting a reverse idle gear from its rest position to a reverse gear train establishment position, and a forward shift fork for establishing one forward gear train. A fixed cam is provided on one side of the cam, and a movable cam that is freely rotatable in only one direction is provided on the other side.
While the fork moves from the rest position of the reverse idle gear to the position on the verge of establishing the reverse gear, the forward shift fork cooperates with the fixed cam to a predetermined small size sufficient to cause the corresponding synchronization mechanism to exert only a synchronizing action. Only the stroke is shifted, but when the reverse shift fork moves forward, it is arranged so that it rotates in one direction so as not to resist the fixed cam, so when the reverse shift fork moves forward, the fixed cam and the movable cam work together to move forward. By shifting the shift fork by a specified small stroke, it is possible to accurately suppress the inertia rotation of the input shaft, and when the reverse shift fork moves back, the load avoidance action of the movable cam avoids unnecessary resistance and reverses. The double-movement operation of the shift fork can be performed easily, and the operation feeling can be expected to be improved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic diagram of an automobile power unit equipped with a transmission to which the present invention is applied, and FIG. 2 is a diagram of a change lever operation pattern of a change device of the present invention. 3 is a longitudinal sectional front view of the change device of the present invention, FIG. 4 is a sectional view taken along the line -- in FIG. 3, and FIG. 5 is a view taken along the V arrow in FIG. 4.
Fig. 5A is an explanatory diagram of the operation in Fig. 5, Fig. 6 is a cross-sectional view taken along the - line in Fig. 4, and Fig. 6A is a -A - line sectional view in Fig. 6.
7 is a partially exploded perspective view of the main parts of the change device, FIG. 8 is a sectional view taken along the - line in FIG. 4,
8A and 8B are explanatory diagrams of the operation of FIG. 8. C...Clutch, E...Engine, D...Differential gear, _G1 to _G4 ...Forward 1st to 4th speed gear train, Gr...
...Reverse gear train, L... specified small stroke, M...
...Transmission, 6...Reverse idle gear, 7...
1-2 speed synchronizing mechanism, 8...3-4 speed synchronizing mechanism, 10...mission case, 11i...input shaft, 11o...output shaft, 22...1-2 speed shift fork, 22a... ...Shift piece, 23...3
-4-speed shift fork, 23a...shift piece, 24...reverse shift member, 24a...shift piece, 39...reverse shift fork,
45...Interlock plate, 45a...Regulation claw, 4
6...Interlock plate, 46a...Regulation claw, 54
... Swinging arm, 60 ... Recess, 64 ... Stopper,
70... One-way cam mechanism, 71... Drive cam as a fixed cam, 72... Driven cam as a movable cam, 72a... Stopper arm, 74... Return spring, 75... Stopper pin.

Claims (1)

[Claims] 1 A multi-stage forward gear train G ₁ to G ₄ established via synchronization mechanisms 7 and 8, respectively, and a reverse gear train established by sliding engagement of the reverse idle gear 6.
In the change device for a vehicle transmission equipped with Cr, a reverse shift fork 39 for shifting the reverse idle gear 6 from its rest position A to a reverse gear train establishment position C, and one forward gear train
A fixed cam 71 is provided on one side of the forward shift fork 23 for establishing _G4 , and a movable cam 72 that is free to rotate in only one direction is provided on the other side. During operation, while the fork 39 moves from the rest position A of the reverse idle gear 6 to the position B on the verge of establishing the reverse gear, it cooperates with the fixed cam 71 to synchronize the forward shift fork 23 with the corresponding synchronization mechanism 8. The vehicle is characterized in that it is shifted by a prescribed small stroke L that is sufficient to exert only the action, but when the reverse shift fork 23 moves forward, it is arranged so as to rotate in one direction so as not to resist the fixed cam 71. gearbox change device.