JPH05118440A - Gear squeak preventing mechanism for manual transmission - Google Patents

Abstract

PURPOSE:To suppress the gear squeak of a reverse idle gear in simple manner by installing a reversal part which shifts a shift fork in the direction for establishing an advance gear train when a shift member is slided in the reverse direction to the probability direction of the advance gear train, in order to establish a retreat gear train. CONSTITUTION:The pin 51a of a five speed reverse shift rod 51 and the pin 32b of a five speed shift fork 32 are engaged with the cam grooves 54d and 54e of a cylindrical member 54 supported on the shift rod 51. While the pin 29d of a shift piece 29 is engaged with the cam groove 33b of a reverse shift fork 33. A reverse idle gear 18 is slided in the direction (g) by driving the shift piece 29 and the shift rod 51 in the (b) direction, in order to establish a retreat gear train. In this case, the shift fork 32 is slightly shifted in the (d) direction by the action of a reversal part 54e1 formed in the cam groove 54e, and the synchronizing mechanism 13 of the five speed gear train is operated only in a short time. Accordingly, the gear squeak in the meshing of the reverse idle gear 18 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a plurality of forward gear trains, each of which is established through a synchronizing mechanism, and a reverse gear train, which is established by a sliding engagement of a reverse idle gear. The present invention relates to a manual transmission that establishes a predetermined forward gear train among the plurality of forward gear trains by sliding, and establishes the reverse gear train by sliding the shift piece in the second direction.

[0002]

2. Description of the Related Art Normally, in establishing a reverse gear train in a vehicle manual transmission, a reverse idle gear supported on a reverse idle shaft is slid in an axial direction by a reverse shift fork, and the reverse idle gear is provided on a main shaft. The reverse drive gear is engaged with a reverse driven gear provided on the counter shaft. Since the shift change to the reverse gear train is performed while the vehicle is stopped, the reverse gear train generally does not have the synchronization mechanism that the forward gear train has.

By the way, while the vehicle is stopped, the counter shaft connected to the drive wheels is in a state in which the rotation is stopped.
Even if the clutch is disengaged and the connection with the engine is disconnected, the main shaft continues to rotate for a short time due to inertia,
When performing a shift change to a reverse gear train, there is a problem that the reverse idle gear does not smoothly mesh with the reverse drive gear provided on the main shaft that rotates due to the inertia, and a gear noise occurs.

Therefore, just before the reverse idle gear is slid in the axial direction to mesh with the reverse drive gear and the reverse driven gear to establish the reverse gear train, the predetermined forward gear train synchronizing mechanism is operated for a short time. It is known to brake the rotation of the main shaft due to inertia, and then mesh a reverse idle gear with a reverse drive gear and a reverse driven gear (for example, JP-A-61-248942 and JP-B-61-3).
987).

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The one described in Japanese Patent No. 8942 has four forward gears and one reverse gear.
In a three-stage manual transmission, synchronization is performed when a reverse gear train is established by using a synchronization mechanism of a forward gear train (3rd-4th gear train) in a shift train different from the reverse gear shift train in the change lever operation pattern. It is acting. Therefore, different shift rods, that is, the 3-4th speed shift fork and the reverse shift fork, which are respectively supported by the 3-4th speed shift rod and the reverse shift rod, need to be interlockingly connected to each other via the cam mechanism. There is a problem in that the layout of the shift rods and shift forks inside the narrow mission case is hindered. Further, such a transmission is provided with an interlock mechanism to prevent simultaneous establishment of different gear trains. In the above-mentioned conventional one, a notch is formed in the interlock plate of the interlock mechanism, which is usually an interlock plate. It is necessary to temporarily allow the movement of the shift piece for the forward gear train whose movement is restricted when the reverse gear train is established, which causes a problem that the structure of the change device is complicated.

Further, the one described in Japanese Patent Publication No. 61-3987 discloses a manual transmission having five forward gears and one reverse gear, in which a fifth gear train is provided on the same shift train in the operation pattern of the change lever. By arranging the reverse gear train, it is possible to selectively operate the synchronizing mechanism of the fifth speed gear train and the synchronizing friction member for the reverse gear train with the common shift rod, and the reverse friction gear train is operated by the synchronizing friction member. It prevents the ringing of gears during establishment. However,
When the friction member for synchronization for the reverse gear train is added as described above, there is a problem that the axial size of the transmission becomes large.

The present invention has been made in view of the above circumstances, and in a manual transmission in which a reverse gear train and a predetermined forward gear train are established via a common shift member, a gear squeal is generated when the reverse gear train is established. The objective is to solve the problems with a simple and compact structure.

[0008]

In order to achieve the above object, a gear squeal preventing mechanism of a manual transmission according to the present invention is provided with a plurality of forward gear trains and a reverse idle gear which are established through a synchronizing mechanism. And a reverse gear train established by meshing, wherein a predetermined forward gear train of the plurality of forward gear trains is established by sliding the shift member in the first direction, and the shift member moves in the second direction. In a manual transmission that establishes the reverse gear train by sliding, the shift member and a shift fork of the predetermined forward gear train are connected via a forward cam mechanism, and the forward cam mechanism is The shift member includes a cylindrical member that is supported by the shift member so as to be relatively rotatable and slidable in the axial direction and is relatively rotatable with respect to the fixed portion and is not slidable in the axial direction, and the shift portion is provided between the cylindrical member and the shift member. A first cam that converts the sliding of the cylinder member into rotation of the cylindrical member is provided, and rotation of the cylindrical member of the shift fork of the predetermined forward gear train is provided between the cylindrical member and the shift fork of the predetermined forward gear train. A second cam that converts into sliding is provided, and in the direction in which the predetermined forward gear train is established when the shift member is slid in the second direction to establish the reverse gear train on the second cam. An inversion portion is provided for moving the shift fork of the forward gear train by a specified small stroke, and the synchronization mechanism of the predetermined forward gear train is caused to perform only the synchronizing action immediately before the establishment of the reverse gear train. It is characterized by preventing gear noise.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 9 show a first embodiment of the present invention. FIG. 1 is a schematic view of an automobile power unit, FIG. 2 is a view showing an operation pattern of a change lever, and FIG. 3 is a vertical section of a change device. FIG. 4 is a sectional view taken along line 4-4 of FIG.
5 is a sectional view taken along line 5-5 of FIG. 4, FIG. 6 is an exploded perspective view of the forward cam mechanism, and FIGS. 7 to 9 are explanatory views of the operation.

As shown in FIG. 1, the output of the engine E is
From the crank shaft, the clutch C, the transmission M, and the differential device D are sequentially transmitted to the left and right wheel drive shafts S _L and S _R ,
Drive these.

Between the main shaft Ms and the counter shaft Cs, which are supported in parallel with each other inside the transmission case of the transmission M, from the engine E side, the forward first speed gear train G ₁ , the reverse gear train G _R , and the forward drive 2 speed gear train G ₂ ~ fifth forward speed gear train G ₅ are provided in parallel. The first speed gear train G ₁ is a main first speed gear 1 fixed to the main shaft Ms and a counter first speed gear 2 rotatably supported by a counter shaft Cs, and the second speed gear train G ₂ is fixed to the main shaft Ms. From the installed main second speed gear 3 and the counter second speed gear 4 rotatably supported on the counter shaft Cs, the third speed gear train G ₃ is a counter and the main third speed gear 5 rotatably supported on the main shaft Ms. From the counter third speed gear 6 fixed to the shaft Cs, the fourth speed gear train G ₄ is a main fourth speed gear 7 rotatably supported by the main shaft Ms and the counter fourth speed gear 8 fixed to the counter shaft Cs. From
The fifth speed gear train G ₅ is composed of a main fifth speed gear 9 rotatably supported on the main shaft Ms and a counter fifth speed gear 10 fixedly mounted on the counter shaft Cs.

Main 1st to 5th gears 1, 3, 5,
7, 9 and counter 1st-5th gears 2, 4, 6, 8, 10
Is always meshed with each other, and between the counter first speed gear 2 and the counter second speed gear 4, there is a 1-2 speed synchronizing mechanism 11 capable of selectively connecting them to the counter shaft Cs, and a main third speed gear 5. A third-fourth speed synchronizing mechanism 12 capable of selectively connecting the main shaft Ms to the main shaft Ms is provided between the main fourth-speed gear 7 and the main fourth speed gear 7, and can be connected to the main shaft Ms near the main fifth-speed gear 9. A 5-speed synchronization mechanism 13 is provided.

When the counter first speed gear 2 or the counter second speed gear 4 is connected to the counter shaft Cs via the first and second speed synchronizing mechanism 11, the first speed gear train G ₁ or the second speed gear train G ₂ Is established. If the main third speed gear 5 or the main fourth speed gear 7 is connected to the main shaft Ms via the third to fourth speed synchronization mechanism 12, the third speed gear train G ₃ or 4
The speed gear train G ₄ is established. Further, if the main fifth speed gear 9 is connected to the main shaft Ms via the fifth speed synchronizing mechanism 13, the fifth speed gear train G ₅ is established. The gear train thus established changes the output torque of the engine E to the main shaft Ms.
The torque transmitted from the counter shaft Cs to the counter shaft Cs with a predetermined gear ratio is transmitted to the differential device D via the final drive gear 14.

The reverse gear train G _R includes a reverse drive gear 15 fixed to the main shaft Ms, and the 1-2nd speed synchronizing mechanism 11 facing the reverse drive gear 15.
The reverse driven gear 16 engraved on the sliding sleeve 11a of the above and a reverse idle shaft 17 arranged in parallel between the main shaft Ms and the counter shaft Cs are slidably and rotatably supported, and the reverse drive is performed. Gear 15 and reverse driven gear 1
6 and a reverse idle gear 18 that can move between an operating position that meshes with the gear 6 at the same time and a rest position that disengages them.

The reverse idle gear 18 is replaced by the reverse drive gear 15 and the reverse driven gear 1.
If moved to 6 mesh to the operating position, is established reverse gear train G _R, the torque of the main shaft Ms reverse drive gear 15, reverse idle gear 18, via the reverse driven gear 16 and the 1-2 speed synchronous mechanism 11 It can be transmitted to the counter shaft Cs and reversed.

Next, will be described with reference to FIG. 2 to FIG. 6 for changing device for establishing the first speed to 5-speed gear train G ₁ ~G ₅ and reverse gear train G _R.

First, FIG. 2 shows the operation pattern of the change lever of the change device, where N is the neutral position and 1 is
Speed position, is second speed position, is third speed position, is fourth speed position,
Is the fifth speed position, and R is the reverse position.

In FIGS. 3 and 4, a change rod 21 interlocked with the change lever is slidably and rotatably supported by a mission case 22. The operation arm 23 fixed to the tip of the change rod 21 is connected to a driven arm 24a formed integrally with the shift arm 24. The shift arm 24 is the change rod 21.
2, a change lever is rotatably and slidably supported by a support shaft 26 supported by a support plate 25 fixed to the transmission case 22 and extending in a direction orthogonal to the change direction.
When the change rod 2 is operated, it is slid by the rotation of the change rod 21, and when operated in the shift direction B, the change rod 2 is moved.
It is designed to be rotated by sliding 1.

Three shift pieces 27, 28, 29 are arranged on the locus along which the drive arm 24b provided on the shift arm 24 moves as the shift arm 24 slides. The drive arm 24b of the shift arm 24 is
When the change lever-position is selected, as shown in FIG.
Engages with the engaging groove 27a of the upper 1st-2nd speed shift piece 27, and engages with the engaging groove 28a of the center 3-4th speed shift piece 28 at the N position of the change lever, that is, when selecting the-position. Also, when selecting the -R position of the change lever, the lower fifth speed-reverse shift piece 29
It engages with the engaging groove 29a.

As can be seen by referring also to FIG.
The upper 1st-2nd speed shift piece 27 is connected to the 1st-2nd speed shift fork 30 which engages with the sliding sleeve 11a of the 1st-2nd speed synchronizing mechanism 11, and the central 3-4th speed shift piece 2 is provided.
8 is a sliding sleeve 12a of the 3-4 speed synchronizing mechanism 12
To the 3rd to 4th speed shift fork 31, and the lower 5th speed-reverse shift piece 29 engages to the sliding sleeve 13a of the 5th speed synchronizing mechanism 13.
And a reverse shift fork 33 that engages with the reverse idle gear 18.

Then, the shift arm 24 is moved upward by 1-2.
When engaged with the speed shift piece 27 and rotated to the left and right in FIG. 3, the 1-2 speed synchronizer 11 is connected to the 1st and 2nd gear trains G ₁ and G ₂ via the 1-2 speed shift fork 30. It can be activated to the established position. Further, if the drive arm 24b of the shift arm 24 is engaged with the central 3-4th speed shift piece 28 and pivoted to the left or right, the 3-4th speed synchronizer 12 is moved to the 3rd speed through the 3rd-4th speed shift fork 31. , 4th gear train G ₃ ,
It is possible to operate to the established position of G ₄ . Further, when the drive arm 24b of the shift arm 24 is engaged with the lower fifth speed-reverse shift piece 29 and rotated leftward, the fifth speed synchronizing device 13 is moved to the fifth speed gear train via the fifth speed shift fork 32. It is possible to operate to the established position of G ₅ , and conversely, if it is rotated to the right, the reverse idle gear 18 can be operated from the rest position to the established position of the reverse gear train G _R via the reverse shift fork 33. it can.

Referring again to FIGS. 3 and 4, a pair of interlock plates 34 and 35 are provided on both sides of the drive arm 24b of the shift arm 24. These interlock plates 3
Numerals 4 and 35 are fitted to the boss portion 24c of the shift arm 24 so as to be rotatable relative to each other, and slidably fitted to a detent pin 36 fixed to the support plate 25 in a state parallel to the support shaft 26. To be done. Therefore, the interlock plates 34 and 35 can slide on the support shaft 26 together with the shift arm 24.
It cannot rotate about 6, and also allows the shift arm 24 to rotate.

Both ends of a stopper pin 37 which is parallel to the support shaft 26 are fixed to the interlock plates 34 and 35 by caulking, and the stopper pin 37 is fixed to the shift arm 24.
It is arranged in the restriction recess 24d provided on one side. Thus, when the shift arm 24 rotates, the contact angle of the shift recess 24d with the stopper pin 37 causes the shift angle of the shift arm 24, and hence the shift forks 30, 31, 3 to be changed.
The shift strokes of 2, 33 are restricted.

The interlock plates 34, 35 are opposed to each other with the tip of the shift arm 24 in between, and the restricting claws 34a, 3 are opposed to each other.
5a, and these control claws 34a, 35 are provided.
a is two shift pieces (for example, 2) other than one shift piece (for example, 29) with which the shift arm 24 is engaged.
7, 28) to prevent malfunction of the two shift pieces.

A first return spring 38 is contracted between the outer surface of one interlock plate 34 and the support plate 25. An annular shoulder portion 26a is formed at the end of the support shaft 26 opposite to the interlock plate 34, and the position regulating plate faces the shoulder portion 26a and the end of the shift arm 24 adjacent thereto. 39 is disposed, and the second return spring 40 is contracted between the outer surface of the position regulating plate 39 and the support plate 25. The set load of the second return spring 40 is equal to the first return spring 38.
It is set larger than that.

By the cooperation of the first and second return springs 38, 40 and the position regulating plate 39, the drive arm 24b of the shift arm 24 is at a position corresponding to the N position of the change lever, that is, 3-4. It is constantly biased to the neutral position where it engages with the speed shift piece 28. When the shift arm 24 is slid against the elastic force of the first return spring 38, the drive arm 24b of the shift arm 24 is moved to the 1-2 speed shift piece 2.
7 and the shift arm 24 to the second return spring 40.
When it is slid against the elastic force of the drive arm 24, the drive arm 24b of the shift arm 24 engages with the fifth speed-reverse shift piece 29. The day tent device 41 for moderating the above-mentioned sliding of the shift arm 24 includes a shift arm 24 and a support shaft 26.
It is provided between.

As shown in FIGS. 4, 5 and 6, the transmission case 22 supports a fifth speed / reverse shift rod 51 in parallel with the main shaft Ms and the reverse idle shaft 17. The boss portion 29b of the fifth speed / reverse shift piece 29 is integrally connected to the fifth speed / reverse shift rod 51. Therefore, when the 5th speed-reverse shift piece 29 is driven by the shift arm 24, the 5th speed-reverse shift rod 51 slides left and right together with the 5th speed-reverse shift piece 29, and the detent device 52 causes the neutral position in the arrow a direction. 5th gear train G ₅ slid on to the established position, reverse gear train G slid in the direction of arrow b
_R Stop at one of the established positions.

A cylindrical member 54 is supported by the 5th-reverse shift rod 51. The cylindrical member 54 has a small diameter portion 54.
a and a large diameter portion 54b, the small diameter portion 54a rotatably and slidably supported on the fifth speed / reverse shift rod 51, and the projection 54c provided on the outer periphery of the large diameter portion 54b. By engaging with the notch 22a formed in the transmission case 22,
Axial sliding is restricted. The small diameter portion 54a
The large diameter portion 54b and the large diameter portion 54b are respectively provided with a first cam groove 54d having a substantially "F" shape and a second cam groove 54e having a substantially "F" shape having an inversion portion 54e _{1 in the} center. The first cam groove 54d of the small diameter portion 54a is engaged with the pin 51a planted on the fifth speed / reverse shift rod 51. A boss portion 32a of a fifth speed shift fork 32 that engages with a fifth speed sliding sleeve 13a of the fifth speed synchronizing mechanism 13 is slidably supported on the fifth speed / reverse shift rod 51. Boss 3
2a is engaged with the inner circumference of the large diameter portion 54b of the cylindrical member 54 so as to be relatively rotatable and axially slidable, and its boss portion 32a.
The second cam groove 54e of the large diameter portion 52b engages with the pin 32b planted in. Then, these first cam grooves 54d,
The second cam groove 54e, advancing cam mechanism C ₅ is constituted by a pin 51a and pin 32b. Mission case 2
An intermediate portion of the reverse shift fork 33 is pivotally supported on a support shaft 55 that is planted on the inner surface of 2. A forked portion 33a formed at one end of the reverse shift fork 33 engages with the reverse idle gear 18, and an "L" -shaped cam groove 33b formed at the other end thereof has a boss portion of the fifth speed-reverse shift piece 29. The pin 29d planted in 29b is engaged. A reverse cam mechanism C _R is composed of the cam groove 33b and the pin 29d.

Next, the operation of the embodiment of the present invention having the above construction will be described.

When the change lever is selected to the -R position in FIG. 2 to establish the fifth speed gear train G ₅ , the drive arm 24b of the shift piece 24 is engaged with the fifth speed-reverse shift piece 29 as shown in FIG. It engages with the groove 29a. When the change lever is shifted to the position shown in FIG. 2 from this state, the drive arm 2 of the shift piece 24 is moved as shown in FIG.
The 5th-reverse shift piece 29 slides together with the 5th-reverse shift rod 51 in the direction of arrow a by 4b.

The fifth speed-reverse shift rod 51 has an arrow a.
When it slides in the direction, the first cam groove 54 is moved by the pin 51a.
The 5th-speed shift fork 32, in which the cylindrical member 54 pressed by d rotates in the direction of arrow c and the pin 32b is pressed by the second cam groove 54e, is the 5th-reverse shift rod 51.
Slide up in the direction of arrow d. As a result, the sliding sleeve 13a of the 5-speed synchronizing mechanism 13 is moved by the 5-speed shift fork 32.
Is driven and the main fifth speed gear 9 is coupled to the main shaft Ms, whereby the fifth speed gear train G ₅ is established.

At this time, the action of the fifth-speed synchronizing mechanism 13 allows the fifth-speed gear train G ₅ to be smoothly established without causing gear noise. 5th-reverse shift piece 29
Even if the pin 29d provided on the boss portion 29b of the fifth speed / reverse shift piece 29 is moved by sliding in the direction of arrow a, the reverse shift fork 33 is formed by the shape of the cam groove 33b with which the pin 29d engages. Is now unaffected.

[0034] When the change lever to establish a reverse gear train G _R to select the -R position of FIG. 2 is shifted to the R position, the drive arm 24b of the shift piece 24 as shown in FIG. 8, the fifth speed - reverse Shift piece 29 is 5
It slides in the direction of arrow b together with the speed-reverse shift rod 51.

5th speed-reverse shift rod 51 is indicated by arrow b
When it slides in the direction, the first cam groove 54 is moved by the pin 51a.
The cylindrical member 54 pressed by d rotates in the direction of arrow e.
At this time, the 5th-speed shift fork 32 whose pin 32b is pressed by the reversing portion 54e ₁ formed in the second cam groove 54e of the cylindrical member 54 is the 5th-reverse shift rod 51.
Slightly slide up in the direction of arrow d. As a result, the sliding sleeve 13a of the fifth speed synchronizing mechanism 13 is slightly driven by the fifth speed shift fork 32 to generate a synchronizing action, and the main shaft Ms which has been rotating by inertia until then is braked.

At the same time, the reverse shift fork 33 pressed against the cam groove 33b by the pin 29d of the fifth speed-reverse shift piece 29 starts swinging in the direction of arrow f to move the reverse idle gear 18 in the direction of arrow g. Slide it.

As shown in FIG. 9, when the fifth speed / reverse shift rod 51 further slides in the direction of the arrow b, the reverse idle gear 18 meshes with the reverse drive gear 15 and the reverse driven gear 16 (not shown), and the reverse gear train. G _R is established. At this time, as described above, the sliding of the fifth speed shift fork 32 in the direction of the arrow d (see FIG. 8) causes the fifth speed synchronization mechanism 13 to operate for a moment to brake the main shaft Ms. The gear 18 is a reverse drive gear 15 and a reverse driven gear 16.
The gear meshes without causing any gear noise. When the reverse gear train G _R is established as described above, the pin 32b of the fifth speed shift fork 32 rides over the reversing portion 54e ₁ of the second cam groove 54e of the cylindrical member 54, and the fifth speed shift fork 32 indicates the arrow h. It is driven in the direction, that is, the direction in which the synchronizing action of the fifth speed synchronizing mechanism 13 is released, and is held at the neutral position.

When the reverse gear train G _R shown in FIG. 9 is returned to the neutral position shown in FIG. 5, the reversing portion 54e ₁ formed in the second cam groove 54e of the cylindrical member 54 causes the fifth speed synchronizing mechanism. 13 operates instantaneously. 5 speed synchronization mechanism 1
The operation of No. 3 is practically no problem, but in order to prevent this, the lost motion mechanism described in Japanese Patent Publication No. 1-58380 may be added. That is, the reversing portion 54e ₁ of the second cam groove 54e is formed by projecting a plate pivotally supported by the cylindrical member 54 into the second cam groove 54e to establish the reverse gear train G _R. When returning from the position to the neutral position, the plate is moved to the second cam groove 54.
The inverted portion 54e ₁ may be eliminated by rocking so as to be separated from e.

FIG. 10 shows a second embodiment of the present invention and corresponds to FIG. 6 of the first embodiment described above.

In this embodiment, the large diameter portion 54 of the cylindrical member 54 is used.
Pin 54f is planted on the inner surface of b, and this pin 54f is
Inversion part 3 formed on boss part 32a of shift fork 32
2c ₁It is engaged with the attached second cam groove 32c. This place
Reverse gear train G_RThe cylindrical member 54 to the neutral position to establish the
When it is rotated in the direction of arrow e from the
By the pin 51f provided, the reversing portion 3 of the second cam groove 32c
2c₁The 5th-speed shift fork 32 that was pressed is temporarily
Sliding in the direction of arrow d, which shortens the fifth speed synchronizing mechanism 13.
Only works for hours. Thus, according to this second embodiment
Also, it is possible to achieve the same effect as the first embodiment.
it can.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various small design changes can be made.

For example, in the embodiment, the first cam groove 54d provided in the small diameter portion 54a of the cylindrical member 54 and the cylindrical member 5
The second cam groove 54e (or the second cam groove 32c provided in the fifth-speed shift fork 32) provided in the fourth large-diameter portion 54b is inclined from the upper left to the lower right. The groove 54d and the second cam groove 54e (the second cam groove 32
Both c) may be inclined from the upper right to the lower left.

[0043]

As described above, according to the present invention, in order to establish a reverse gear train in the forward cam mechanism that connects the shift member and the shift fork of the predetermined forward gear train, the shift member is used. When sliding in the direction opposite to the established direction of
Since the reversing portion for moving the shift fork of the forward gear train in the direction in which the forward gear train is established is moved by the specified small stroke, only the synchronizing action is performed on the synchronizing mechanism of the forward gear train just before the reverse gear train is established. In addition, the ringing of the reverse idle gear can be prevented. Then, a common shift member is connected to the forward gear train and the reverse gear train by a cam mechanism having a high degree of freedom in design, and the predetermined forward gear train is connected by sliding the shift member in the first direction or the second direction. Since the reverse gear train is selectively established, the notch of the interlock plate and the synchronizing friction member for the reverse gear train, which were required in the past, are not required, and as a result, the reverse idle gear gear noise prevention mechanism is eliminated. The structure is simplified and the structure is made compact.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an automobile power unit.

FIG. 2 is a diagram showing a change lever operation pattern.

FIG. 3 is a vertical sectional view of the change device.

4 is a sectional view taken along line 4-4 of FIG.

5 is a sectional view taken along line 5-5 of FIG.

FIG. 6 is an exploded perspective view of a forward cam mechanism.

FIG. 7 is an explanatory diagram of operation

FIG. 8 is an explanatory diagram of the operation

FIG. 9 is an explanatory diagram of operation

FIG. 10 is a diagram corresponding to FIG. 6 according to the second embodiment.

[Explanation of symbols]

11 1-2 speed synchronous mechanism (synchronous mechanism) 12 3-4 speed synchronous mechanism (synchronous mechanism) 13 5 speed synchronous mechanism (synchronous mechanism) 18 reverse idle gear 22 mission case (fixed part) 29 5th speed-reverse shift piece ( Shift member) 32 5th speed shift fork (shift fork) 32c second cam groove (second cam) 32c ₁ reversing portion 51 5th speed-reverse shift rod (shift member) 54 cylindrical member 54d first cam groove (first cam) 54e second cam groove (second cam) 54e ₁ inverting section C ₅ advancing cam mechanism G ₁ ~G ₅ forward gear train G _R the reverse gear train

Claims (1)

[Claims] 1. Synchronizing mechanism (11, 12, 13), respectively
A plurality of forward gear trains (G _{1 to} G ₅ ) established via
And a reverse gear train established by sliding engagement of the reverse idle gear (18) (G _R), a shift member (29,5
Establishes a predetermined forward gear train of said plurality of forward gear train by sliding in the first direction of _{1) (G 1 ~G 5)} (G 5), said shift member (29,51) Second
In manual transmission for establishing the reverse gear train by sliding in the direction (G _R), advancing a shift fork (32) of the shift member (29,51) and said predetermined forward gear train (G ₅₎ become connected via the use cam mechanism (C _5), said forward cam mechanism (C ₅₎ is the shift member (2
9, 51) includes a cylindrical member (54) which is supported by relative rotation and axial slidability and is relatively rotatable and axially non-slideable with respect to the fixed portion (22).
4) and the shift member (29, 51) are provided with a first cam (54d) for converting sliding of the shift member (29, 51) into rotation of the cylindrical member (54), and the cylindrical member (54d). 54) and the predetermined forward gear train (G ₅₎ shift fork (32) wherein the predetermined forward gear train rotation of said cylindrical member (54) between (G ₅₎ shift fork (3 of
Second cam that converts the sliding of 2) (54e, 32c) and is provided, the second cam (54e, 32c) to said reverse gear train (the shift member to establish a G _R) (29,51) Is slid in the second direction, the predetermined forward gear train (G
₅ ) is provided with a reversing portion (54e ₁ , 32c ₁ ) for moving the shift fork (32) of the forward gear train (G ₅ ) by a specified short stroke, and the reverse gear train (G _R ) The manual transmission is characterized in that the squealing of the reverse idle gear (18) is prevented by causing the synchronizing mechanism (13) of the predetermined forward gear train (G ₅ ) to perform only the synchronizing action immediately before establishment. Gear noise prevention mechanism.