JPH0532630B2 - - 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 transmission described above, 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 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; It is configured to deform and lose the shifting function for the forward shift fork when receiving an operating load exceeding a value, and when the forward shift fork is shifted by this resilient mechanism,
In order to cause only a synchronizing action in the synchronizing mechanism corresponding to the shift fork, the shift piece of the shift fork is brought into contact with the bottom surface of the recess of the interlock plate facing it, and just before the reverse gear train is established,
The inertial rotation of the input shaft is stopped or weakened by the synchronizing action of the synchronizing mechanism.

(3) Problems to be Solved by the Invention In the conventional device described above, when the reverse shift fork is operated rapidly, the spring mechanism deforms early during the synchronizing action of the synchronizing mechanism, causing the input shaft to deform. Rotation may not be suppressed satisfactorily, and each time the reverse shift fork is operated, the deformation load of the rebound mechanism acts on the contact area between the shift piece and the interlock plate, producing a collision sound. In addition, there are drawbacks such as the durability of the abutting portions being impaired to some extent.

SUMMARY OF THE INVENTION An object of the present invention is to provide a change device capable of eliminating the drawbacks of the conventional device described above without impairing the original function of the interlock plate for preventing malfunction of each shift fork. do.

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; and a forward shift fork for establishing one forward gear train, the forward shift fork is moved between the forward shift fork and the reverse gear fork in response to the reverse idle gear operating from a rest position to a position on the verge of establishing a reverse gear train. A cam mechanism is provided to shift the corresponding synchronizing mechanism by a prescribed small stroke sufficient to exert only a synchronizing action, and when the change lever is shifted to the reverse position, an interlock plate facing the shift piece of the forward shift fork is provided with a cam mechanism that shifts the forward shift fork. A recess that allows only the small stroke shift operation of the shift fork is provided, and a shift piece of another forward shift fork that faces the recess when the change lever is in the neutral position is configured to prevent the shift piece from entering the forward recess. The present invention is characterized in that a stopper is provided that can engage with the outer surface of the interlock plate to prevent the interlock plate from interlocking.

(2) Effect When the reverse shift fork is operated to establish the reverse gear train, first, while the reverse shift fork operates from the rest position of the reverse idle gear to the position on the verge of establishing the reverse gear train, the cam mechanism is activated. It operates to reliably shift the forward shift fork of one forward gear train by a predetermined small stroke, so that only a synchronizing action is produced in the synchronization mechanism of the forward gear train, and the inertial rotation of the input shaft is accurately suppressed. I can do it. Therefore, further actuation of the reverse shift fork allows the reverse idle gear to be smoothly shifted to the establishment position of the reverse gear train without causing gear squeal.

During this time, the recessed portion of the interlock plate allows the forward shift fork to perform a small stroke shift operation, thereby making it possible to avoid a collision between the shift piece of the forward shift fork and the interlock plate.

When the change lever is returned to the neutral position, the recess faces the shift piece of another forward shift fork, but due to the abutment between the stopper specially provided on the shift piece and the outer surface of the interlock plate having the recess, the recess faces the shift piece of another forward shift fork. The shift piece is prevented from entering the recess, and the forward shift fork is prevented from malfunctioning.

(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.
It is transmitted to S' and drives it.

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 engraved on the sliding sleeve 7a of the second-speed synchronization mechanism 7 and the intermediate shaft 14 arranged parallel to the input and output shafts 11i and 11o are obstructed from sliding and rotating freely. and input above, output gear 5
It consists of a reverse idle gear 6 which can be moved between an operating position in which it engages 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 is in the - position selector 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 bead 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; Also, if the shift arm 19 is engaged with the center shift piece 23a and rotated left and right, the 3-4 speed shift fork 23a
slide left and right on the fork shaft 27, and
The fourth gear synchronizer 8 can be operated to the position where the third and fourth 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. Furthermore, 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.
8 is engaged with a long hole 40 formed in the middle part of the reverse shift fork 39, as shown in FIG. The reverse shift fork 39 is connected to the support plate 2
1, 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. 5A).

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.

Thus, by the cooperation of the first and second return springs 51 and 52 and the position regulating plate 53, the shift arm 19
is the position corresponding to the N position of the change lever, that is, the shift bead 2 of the 3rd-4th speed shift fork 23
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 closes 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.
are integrally connected, and a pair of driving and driven cams 55 and 56 are respectively protruded from opposing surfaces of the swing arm 54 and the 3-4 speed shift fork 23. These cams 55 and 56 cooperate with each other to shift the 3-4 speed shift fork 23 while the reverse shift fork 39 shifts the reverse idle gear 6 from the rest position A to the position B where the reverse gear train Gr is about to be established. It is formed so that it can shift with a small stroke L in the direction of establishing the 4th speed gear train _G4 , and the small stroke L is sufficient for the 3rd-4th speed synchronizing mechanism 8 to perform a synchronizing action. The setting is made so that the fourth gear _G4 is not established.

In this case, as described above, it is extremely important to keep the fork shaft 27 stable at a fixed position by the holding spring 34 in order to accurately obtain the specified small stroke L of the 3-4 speed shift fork 23 by the cams 55 and 56. It is valid.

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 drive cam is shifted by the swing of the swing arm 54. 55 pushes the driven cam 56 to shift the 3rd-4th gear shift fork 23 by a prescribed small stroke L in the direction of establishing the 4th gear train _G4 .
By obtaining only the synchronizing action of the 4-speed synchronizing mechanism 8, the input shaft 1
The inertial rotation of 1i can be stopped or weakened. Therefore, if the reverse idle gear 6 is shifted to the established position C of the reverse gear train Gr by the progress of the rotation of the reverse shift fork 39, the input and output gears 5i and 5o can be shifted without causing gear squeal.
can be meshed smoothly.

In the above, the swinging arm 54 and the driving and driven cams 55 and 56 constitute the cam mechanism 57 of the present invention.
It is preferable that at least one of the cams 55 or 56 be formed of a roller, as this will allow the cam mechanism 57 to operate more smoothly.

When the reverse shift member 24 is operated as described above, the 4th gear G ₄ of the 3rd-4th speed shift fork 23
In order to allow movement of a prescribed small stroke L in the direction of establishment, as shown in FIG. A recess 60 is provided. Therefore, when the 3rd-4th gear shift fork 23 is slightly shifted in the direction of establishing the 4th gear train _G4 , the shift piece 23a
A part of the interlock plate 45 enters the recess 60, thereby avoiding interference with the regulating pawl 45a of the interlock plate 45.

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
can collide with the slope 62 of the shift piece 23a and return the shift piece 23a to its original position.

When the shift arm 19 occupies 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 to protrude from the outer surface of the regulating pawl 45a. 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 45a 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. , the forward shift fork is sufficient to cause the corresponding synchronization mechanism to exert only a synchronizing action in response to the reverse shift fork operating from the rest position of the reverse idle gear to a position on the verge of establishing the reverse gear train. A cam mechanism for shifting by a prescribed small stroke is provided, and when the change lever is shifted to the reverse position, an interlock plate facing the shift piece of the forward shift fork has a recess that allows only the small stroke shift operation of the forward shift fork. Therefore, when operating the reverse shift fork to establish the reverse gear train, first, while the reverse shift fork operates from the rest position of the reverse idle gear to the position on the verge of establishing the reverse gear train, the cam mechanism is By this operation, the forward shift fork of one forward gear train can always be reliably shifted by a predetermined small stroke, and therefore, regardless of the speed or speed of the shift operation, only a synchronizing effect is exerted on the synchronization mechanism of the forward gear train. can always be sufficiently generated. As a result, the inertial rotation of the input shaft can be accurately suppressed at all times, so further operation of the reverse shift fork will always smoothly shift the reverse idle gear to the position where the reverse gear train is established, without causing gear squeal. can be shifted to. Moreover,
At this time, the small stroke shift operation of the forward shift fork is easily allowed due to the presence of the recess in the interlock plate, so it is possible to avoid a collision between the shift piece of the forward shift fork and the interlock plate. Therefore, there is no impact noise, and there is no risk of impairing the durability of the shift piece and interlock plate.

Further, when the change lever assumes the neutral position, the shift piece of another forward shift fork faces the recess, and in particular in the present invention, the shift piece of the other forward shift fork faces the recess of the shift piece. Since a stopper is provided that can engage with the outer surface of the interlock plate to prevent the shift piece from entering, when the change lever is returned to the neutral position, the stopper and the outer surface of the interlock plate engage with each other to prevent the shift piece from entering. can be prevented from entering the recess, thereby reliably preventing the other forward shift fork from malfunctioning, and therefore,
It is possible to reliably prevent the fork from rattling or the corresponding synchronization mechanism from repeating unnecessary synchronization actions due to running vibrations, etc.
Although the interlock plate itself is specially provided with the recessed portion, the original function of the interlock plate is not impaired in any way.

[Brief explanation of the drawing]

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.
5A is an explanatory diagram of the operation in FIG. 5, FIG. 6 is a sectional view taken along the line - - in FIG. 4, FIG. 7 is a partially exploded perspective view of the main parts of the change device, and FIG. The sectional view, FIG. 8A, and FIG. 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, 7...1-2 speed synchronization mechanism, 8...3
-4-speed synchronization 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, 45...Interlock plate, 45a...Regulation claw, 46...Interlock plate, 46a...Regulation claw, 54...Swinging arm, 55...
... Drive cam, 56 ... Driven cam, 57 ... Cam mechanism, 60 ... Recess, 64 ... Stopper.

Claims (1)

[Claims] 1. In a change device for a vehicle transmission equipped with 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 reverse idle gear is moved backward from its rest position. Between the reverse shift fork for shifting to the gear train establishment position and the forward shift fork for establishing one forward gear train, the reverse shift fork moves from the rest position of the reverse idle gear to the position on the verge of establishing the reverse gear train. A cam mechanism is provided that shifts the forward shift fork by a predetermined small stroke sufficient to cause the corresponding synchronizing mechanism to exert only a synchronizing action in response to the movement of the forward shift fork. An interlock plate facing the shift piece of the shift fork is provided with a recess that allows only the small stroke shift operation of the forward shift fork, and when the change lever is in the neutral position, another forward shift fork that faces the recess is shifted. A change device for a vehicle transmission, characterized in that the piece is provided with a stopper that can engage with the outer surface of the interlock plate so as to prevent the shift piece from entering the recess.