JP2000018381A - Reverse gear squeak preventing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a gear squeak of a reverse gear by inhibiting a rotation against a cam member at an initial time of a reverse shift and slightly acting an ahead stage synchronizing mechanism by a stroke of a movable cam moving with the cam member to stop the rotation of a main shaft. SOLUTION: In a reverse gear squeak preventing device 164, a cam member 166 positioned between a first supporting body 128 and an interlock plate 96 is mounted to a shift and select shaft 92 to which the interlock plate 96 is attached. The reverse gear squeak preventing device 164 inhibits a rotation against the cam member 166 at an initial time of a reverse shift. Second gear speed synchronizing mechanism is certainly acted slightly by a stroke of a movable cam 188 moving with the cam member 166 and a rotation of a main shaft is stopped by a synchronizing action of the second gear speed synchronizing mechanism. Thereby, a gear squeak of a reverse gear can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverse gear squeal preventive device, and more particularly to a reverse gear squeal preventive device which can reliably prevent reverse gear sway irrespective of shaft speed and shift load, and can be applied to transmissions of different constructions. Further, the present invention relates to a reverse gear squeak prevention device capable of ensuring the reliability of the reverse gear squeal prevention operation without affecting the operation of the forward gear synchronizing mechanism operated when the reverse gear squeal is prevented.

[0002]

2. Description of the Related Art A vehicle is provided with a manual or automatic transmission in order to convert the power of an internal combustion engine as required according to running conditions and to extract the power. Such transmissions include a gear-type transmission and a belt-type transmission, and a gear-type transmission with small power transmission loss is frequently used.

[0003] The gear type manual transmission has a plurality of speed change gear trains, and the power train of the internal combustion engine is changed in accordance with the running conditions by switching the gear trains with a shift lever to mesh the gears of each stage. And convert it to the required one.

[0004] In such a gear type manual transmission, there are, for example, a selective sliding type, a constant meshing type and the like according to a method of switching a gear ratio.

[0005] In a selective sliding type manual transmission, gear pairs for the required number of gears are arranged on two shafts, and either one of these gear pairs can slide in the axial direction with respect to the shaft. The other of the pair of gears, which is fixed to the shaft by sliding one of the gears spline-engaged to the shaft in the axial direction while the other is fixed to the shaft. By meshing with a gear, a torque of a required speed ratio is transmitted.

In addition, the constant mesh type manual transmission has a structure in which gear pairs for the required number of gears are constantly meshed, and a structure in which the shaft and the gear can idle is provided, so that a gear having a required gear ratio can be obtained. The pair is fixed to the shaft by a coupling sleeve on the shaft to transmit torque.

[0007]

Incidentally, in the manual transmission of the constant mesh type, since the reverse gear is normally operated with the reverse gear engaged when the vehicle is stopped, it is of the selective sliding type. However, when the reverse gear meshes, the sleeve gear of the stationary counter shaft and the main reverse gear of the main shaft that rotates by inertia even after the clutch is disengaged via the reverse idler gear that slides on the reverse idler shaft. Since the gears are engaged with each other, there is a disadvantage that the gears squeal and give discomfort, and each part is damaged and the life is shortened.

In order to solve this drawback, a synchronous mechanism may be provided as a constant mesh type, like other gears.
As the weight increases, the structure becomes complicated and more expensive, which is disadvantageous from a practical and economical point of view.

For this reason, a simple synchronizing mechanism for simply stopping the rotation of the main shaft before the reverse idler gear meshes with the sleeve gear has been used.

One of such configurations is, for example, when a reverse shift operation is performed during a shift to a reverse gear, a reverse gear, for example, a second speed synchronizing mechanism is lightly operated to stop the rotation of the main shaft. There is gear squeal prevention device.

In this case, it is necessary to temporarily operate the second-speed synchronization mechanism and release the second-speed synchronization mechanism before the engagement of the second-speed gear occurs. Normally, a method is used in which the two-speed synchronization mechanism is operated by using the repulsive force of the spring, and the two-speed synchronization mechanism is released by pressing the spring against the stopper before each gear meshes to compress the spring.

[0012] Such a reverse gear squeak preventive device is disclosed in Japanese Patent Application Laid-Open Nos. Hei 5-1059 and Hei 8-3269.
There is one disclosed in Japanese Patent Application Publication No. 13-131.

[0013] Japanese Unexamined Patent Publication No. Hei 5-1059 discloses a shift rod that operates a synchronous meshing device at a specific forward gear and a selective sliding reverse gear device, and a rotation about an axis. In a gear noise prevention device having a control rod that engages with a shift rod and moves the shift rod to the synchronous meshing device and the reverse gear device by moving in the axial direction, a gear noise prevention device is provided between the control rod and the shift rod. A cam mechanism for shifting the shift rod to the specific forward gear with the rotation of the control rod toward the shift rod, the cam mechanism comprising a sleeve having a spherical projection, a cam plate, a ball member, The spring prevents the gear from shifting when shifting to reverse.

Japanese Patent Application Laid-Open No. 8-326913 discloses a cam member of a shift-and-select shaft which is mounted so as to be movable in the axial direction and not in the circumferential direction. A cam spring for pressing the shift yoke is provided. The cam spring engages the engaging portion of the cam member with the first-speed / second-speed shift yoke at the initial stage of the reverse shift to move the cam member in the first-speed shift direction by a small amount. This is to prevent gear squeal.

However, these conventional reverse gear squeal prevention devices all operate the cam mechanism by the spring load to stop the rotation of the shaft. Therefore, depending on the shaft rotation speed and the shift load, the spring load is sufficient. In some cases, the cam mechanism cannot be operated, and the gear squeak prevention effect cannot be obtained.

[0016] For this reason, the conventional reverse gear squeak prevention device has a disadvantage that the squeal prevention of the gear squeal of the reverse gear cannot be reliably achieved by operating the cam mechanism by the spring load. Also, when applied to a transmission with a different configuration, the spring load of the cam mechanism
When the shaft rotation speed and the shift load are different for each transmission, the cam mechanism cannot be operated sufficiently, and the gear squeak prevention effect may not be obtained.

[0017]

In order to eliminate such inconveniences, the present invention provides a shift-and-select shaft which is axially moved at the time of selection and is moved circumferentially at the time of shift by operating a shift lever. Provided,
A shift and select lever is attached to the shift and select shaft, and when the shift and select lever is moved from the reverse select position to the reverse shift position, the forward gear synchronizing mechanism is slightly operated to prevent gear squeal. In the prevention device, the shift and select shaft includes a cam member that is opposed to a pair of yoke portions of a forward gear shift yoke that operates the forward gear synchronization mechanism when the shift and select lever is moved to a reverse select position. The cam member is provided with a movable cam that is supported between the pair of yoke portions when the shift and select lever is moved to the reverse select position. Move lever from reverse select position to reverse shift position When the cam member is moved from the original position, the cam member is prevented from rotating from its original position, and the forward gear shift yoke is slightly moved toward the forward gear shift position side by engagement with one of the pair of yoke parts. Then, when the shift and select lever is moved from the reverse shift position to the reverse select position, the cam member is allowed to rotate from its original position when the shift and select lever is moved from the reverse shift position to the reverse select position. The cam member is rotatably supported on the cam member so as to be located between the pair of yoke portions over the one yoke portion from which the engagement is released.

The movable cam rides over one of the yoke portions of the pair of yoke members at a position where the forward shift shaft provided with the forward shift yoke is returned to the neutral position by the positioning mechanism. The movable cam is provided with a notch in which an engaging portion at the tip of the movable cam engages with one of the pair of yoke members. A cam spring is provided which, when allowed to rotate, moves over the one yoke part disengaged and returns to the original position when it is positioned between the pair of yoke parts.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The reverse gear squeal prevention device of the present invention is movable between a pair of yoke portions of a forward shift yoke when a shift and select lever is moved from a reverse select position to a reverse shift position. The cam is prevented from rotating from its original position with respect to the cam member,
After the forward gear shift yoke is slightly moved to the forward gear shift position side by engaging with one of the pair of yoke parts, the engagement is released by climbing over the one yoke part. In this way, the rotation of the cam member is prevented at the initial stage of the reverse shift, and the stroke of the movable cam that moves together with the cam member can reliably operate the forward gear synchronizing mechanism with a small allowance. The rotation of the main shaft can be stopped, and gear squeal of the reverse gear can be prevented.

Further, the reverse gear squeak prevention device is provided with:
When moving the shift and select lever from the reverse shift position to the reverse select position, the movable cam that has passed over one yoke portion is allowed to rotate from its original position with respect to the cam member, and the one of the disengaged ones is released. The movable cam can be returned between the pair of yoke portions without being locked by the one yoke portion when returning to the reverse select position by being positioned between the pair of yoke portions over the yoke portion. .

The movable cam is disengaged by moving over one of the pair of yoke members at a position where the forward shift shaft provided with the forward shift yoke is returned to the neutral position by the positioning mechanism. As a result, it is possible to reliably release the forward gear synchronizing mechanism that was operated at the beginning of the reverse shift.

In addition, a notch is provided in one of the yoke members of the pair of yoke members so that the engaging portion at the tip of the movable cam is engaged, so that the movable cam and the one yoke portion can be securely connected. Can be engaged.

Further, the movable cam is allowed to rotate from its original position with respect to the cam member, and moves over one of the disengaged yoke portions so as to return to its original position when positioned between the pair of yoke portions. By providing the returning cam spring, it is possible to reliably return to the original position with respect to the cam member.

[0024]

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

1 to 13 show an embodiment of the present invention. In FIG. 5, reference numeral 2 denotes a constantly meshing manual transmission (hereinafter simply referred to as "transmission"), 4 denotes a gear unit, 6 denotes a differential unit, and 8 denotes a transmission case. In the transmission case 8, a main shaft 1 which is an input shaft connected to a crankshaft of an internal combustion engine (not shown) via a clutch (not shown) is provided.
0, the counter shaft 12 and the reverse idler shaft 14 are arranged in the longitudinal direction of the transmission 2 and substantially in parallel.

The main shaft 10 includes a first main shaft bearing 20 held on a right wall portion 18 of a right case 16 of the transmission case 8 and a left case 22 of the transmission case 8.
Main shaft bearing 26 held by the left wall portion 24
And are rotatably supported.

The counter shaft 12 includes a light case 16
Counter shaft bearing 2 held by the light wall portion 18
8 and a second counter shaft bearing 30 held on the left wall portion 24 of the left case 22 so as to be rotatable.

The reverse idler shaft 14 is supported by the right wall 18 and a support 32 fixed to the left case 24.

On the main shaft 10, a first-speed main gear 34, a reverse main gear 36, and a second-speed main gear 38 are fixedly provided in order from the internal combustion engine side, and a third-speed main gear 40 and a fourth-speed main gear 42 A fifth speed main gear 46 is rotatably provided in a side case 44 of the transmission case 8.

A final drive gear 50 constituting a final reduction mechanism 48 is fixedly provided on the counter shaft 12 sequentially from the side of the internal combustion engine, and a first-speed counter gear 52 meshing with the first-speed main gear 34 and a second-speed A second speed counter gear 54 meshing with the main gear 38 is rotatably provided, and a third speed counter gear 56 meshing with the third speed main gear 40, a fourth speed counter gear 58 meshing with the fourth speed main gear 42, and inside the side case 44. A fifth speed counter gear 60 meshing with the fifth speed main gear 46 is fixedly provided.

A reverse idler gear 62 is rotatably provided on the reverse idler shaft 14. A reverse sleeve 64 is provided integrally with the reverse idler gear 62. The reverse idler gear 62 is
It is provided so as to mesh with the reverse main gear 36 and a sleeve gear 70 described later by sliding in the axial direction.

The final drive gear 50 is engaged with a final driven gear 66 provided in the differential section 6.

On the counter shaft 12 between the first-speed counter gear 52 and the second-speed counter gear 54, a first-speed / second-speed sleeve 68 is provided. The first-speed / second-speed sleeve 68 is provided integrally with a sleeve gear 70 as a reverse counter gear. The sleeve gear 70 is provided so as to mesh with the reverse idler gear 62.

On the counter shaft 12 between the first-speed / second-speed sleeve 68 and the first-speed counter gear 52, a first-speed synchronization mechanism 7 is provided.
2 are provided. A second speed synchronization mechanism 74 is provided on the counter shaft 12 between the sleeve gear 70 and the second speed counter gear 54.

On the main shaft 10 between the third speed main gear 40 and the fourth speed main gear 42, a third speed / fourth speed sleeve 76 is provided.
Is provided.

A third speed synchronizing mechanism 78 is provided on the main shaft 10 between the third speed / fourth speed sleeve 76 and the third speed main gear 40. In addition, 3-speed / 4-speed sleeves 76 and 4
On the main shaft 10 between the high speed main gears 42, a fourth speed synchronization mechanism 80 is provided.

The main shaft 10 has a 5-speed main gear 4
A fifth-speed sleeve 82 is provided adjacent to the sixth gear. The main shaft 10 between the fifth speed sleeve 82 and the fifth speed main gear 46
Is provided with a five-speed synchronization mechanism 84.

In the transmission 2, the meshing state of the gear section 4 is switched by a shift operation section 86. The shift operation unit 86
As shown in FIGS. 1 to 3, the shaft holding portion 88 of the transmission case 8 is provided.
A shift and select shaft 92 is held and provided at 90. The shift-and-select shaft 92 is moved in the axial direction at the time of selection through a control shaft (not shown), a control lever 94, or the like by operation of a shift lever (not shown) (not shown), and rotates around the axis at the time of shift. Moved in the direction.

The shift and select shaft 92 has an interlock plate 9 formed in a substantially C shape for preventing malfunction.
6 is provided. Interlock plate 96
The first and second side portions 9 and 100 are connected to each other at one end sides of first and second side portions 98 and 100 parallel to each other by a connecting portion 102.
8 and 100 are provided with first and second guide portions 104 and 106 which are bent so as to face each other.
A bolt insertion hole 108 is provided in the first and second guide portions 102.
A lever groove 110 is provided between 104.

The interlock plate 96 includes first and second
The shift and select shaft 94 is inserted into the guide portions 102 and 104, and the tip end 114 of the plate holding bolt 112 attached to the transmission case 8 is inserted into the bolt insertion hole 108, so that the shift and select shaft 92 is moved in the axial direction of the shift and select shaft 92. It is movably supported.

On one side of the shift and select shaft 92 on which the interlock plate 96 is mounted, a one-side fixed body 116 is fixedly mounted away from the interlock plate 96. Between the one-side fixed body 116 and the interlock plate 96, a one-side return spring 118 loosely fitted on the shift and select shaft 92 is elastically supported via one-side first and second supports 120 and 122. Is established.

On the other side of the shift and select shaft 92 on which the interlock plate 96 is mounted, another side fixed body 124 is fixedly mounted away from the interlock plate 96. The other fixed body 124 and the interlock plate 96
The other return spring 126 loosely fitted to the shift and select shaft 92 is elastically provided between the first and second support members 128 and 130 between the first and second support members 128 and 130.

A shift and select lever 132 is attached to the shift and select shaft 92 in the interlock plate 96. Interlock plate 9
6 is prevented by the shift and select lever 132 from moving the shift and select shaft 92 in the axial direction.

As a result, the one-side return spring 118 presses the shift and select shaft 92 operated to the fifth speed / reverse select position toward the neutral position. The other-side return spring 126 is resiliently provided on the interlock plate 96 via a cam member 166 described later, and presses the shift-and-select shaft 92 operated to the first-speed / second-speed select position toward the neutral position.

At one end of the shift and select lever 132, a lever member 134 is provided. The lever member 134 is selectively engaged with the first speed / second speed shift yoke 136, the third speed / fourth speed shift yoke 138, and the fifth speed / reverse shift yoke 140.

The first-speed / second-speed shift yoke 136 is a first-speed / second-speed shift yoke.
The second speed shift shaft 142 is provided. The third / fourth shift yoke 138 is provided on the third / fourth shift shaft 144. The fifth speed / reverse shift yoke 140 is provided on a fifth speed / reverse shift shaft 146 and is guided by a fifth speed / reverse guide shaft 148. These first gear
2nd speed shift shaft 142, 3rd speed / 4th speed shift shaft 144, 5th speed / reverse shift shaft 146, 5th speed / reverse guide shaft 1
Reference numeral 48 denotes a shaft supported by the transmission case 8 so as to be movable in the axial direction.

The first / second speed shift shaft 142 is provided with a first / second speed fork 150 for operating the first / second speed sleeve 68. The first and second speed forks 150
The first and second speed sleeves 68 are engaged. The third speed / fourth speed shift shaft 144 is provided with a third speed / fourth speed fork 152 for operating the third speed / fourth speed sleeve 76. The third speed / fourth speed fork 152 is engaged with the third speed / fourth speed sleeve 76.

The fifth speed / reverse shift shaft 146 has:
A fifth speed fork 154 for operating the fifth speed sleeve 82 is provided. The fifth speed fork 154 is engaged with the fifth speed sleeve 82. Also, this 5-speed reverse shift shaft 146
Is provided with a reverse gear shift arm 156.
The reverse gear shift arm 156 swings a reverse gear shift lever 158 engaged with the reverse sleeve 64 to operate the reverse idler gear 36.

A guide 160 is provided at the other end of the shift and select lever 132. Guide part 1
Reference numeral 60 denotes a tip 11 of the plate holding bolt 112.
4 is provided with a guide recess 162 in which the loose fit is provided. The shift and select lever 132 is connected to the plate holding bolt 1
The select stroke and the shift stroke are regulated by the front end portion 114 of the twelve and the guide concave portion 162.

The transmission 2 is provided with a reverse gear squeal prevention device 164. Reverse gear squeak prevention device 16
4 is provided on the other side of the shift and select shaft 92 on which the interlock plate 96 is mounted, on the other side of the first support 128.
And a cam member 166 is attached and provided. As shown in FIG. 2, when the shift and select lever 132 is moved to the reverse select position, the cam member 166 operates the second-speed synchronizing mechanism 74 that is the forward-stage synchronizing mechanism. The shift yoke 136 is opposed to the pair of first speed yoke portion 168 and second speed yoke portion 170.

As shown in FIGS. 6 to 11, the cam member 166 is provided with a fitting hole 174 for fitting the shift and select shaft 92 in an annular fitting portion 172.
A mounting hole 176 is formed and provided in the radial direction of the
A protruding portion 178 having a substantially triangular plate shape is provided so as to protrude from the outer periphery of. A pair of abutting portions 180 are formed on both sides near the tip of the protruding portion 178 to provide a supporting portion 182 thinner than the protruding portion 178, and a supporting hole 184 is provided in the supporting portion 182. The cam member 166 is mounted on the shift and select shaft 92 by a mounting shaft 186 inserted through the mounting hole 176.

When the shift and select lever 132 is moved to the reverse select position, the cam member 166 is located between the pair of first speed yoke portion 168 and second speed yoke portion 170 of the first speed / second speed shift yoke 136. A movable cam 188 to be positioned is pivotally provided.

The movable cam 188 is provided with a substantially columnar engaging portion 192 at the distal end of a movable portion 190 formed in a substantially triangular plate shape so as to conform to the shape of the distal end side of the fitting portion 172 of the cam member 166. The support portion 182 is provided at the base of the movable portion 190.
Are formed, and a pair of mounting portions 196 disposed on both sides of the support portion 182 are provided.
The pair of mounting portions 196 have a contact portion 1 of the cam member.
Each of the locking portions 198 to be brought into contact with 80 is provided, and each of the shaft holes 200 corresponding to the support holes 184 is provided.

The engaging portion 192 at the tip of the movable cam 188 is
A pair of first speed yoke portions 1 of the first speed / second speed shift yoke 136
When positioned between the first and second speed yoke portions 170, 170, one of the first speed yoke portions 168 and the second speed yoke portion 170, a cutout provided inside the second speed yoke portion 170 in this embodiment. 202 is engaged.

In the movable cam 188, the support portion 182 of the cam member 166 is inserted into the mounting groove 194, and a pair of mounting portions 196 are provided on both sides of the support portion 182. 196 and the support shaft 204
Is rotatably supported on the cam member 166 by being inserted.

The movable cam 188 is allowed to rotate in the direction of the arrow D1 until the engaging portion 198 contacts the contact portion 180 of the cam member 166, and the original position where the engaging portion 198 contacts the contact portion 180. , The rotation in the direction of arrow D1 is prevented, and the rotation in the direction of arrow D2 is allowed from the original position where the locking portion 198 abuts on the abutting portion 180.

The movable cam 188 has a cam member 166.
A cam spring 206 is provided for urging the motor to return to the original position when it is rotated from the original position.
As shown in FIGS. 6 to 9, the cam spring 206 is provided with a pair of winding portions 208 supported by the support shaft 204, and a substantially U-shaped first locking portion is formed from the pair of winding portions 208. 21
The 0 and the second locking portions 212 are respectively extended. The cam spring 204 supports the pair of winding portions 208 at both ends of the support shaft 204, and the first locking portion 210 is elastically locked to the projection 178 of the cam member 166, and the second locking portion is provided. 212 is provided on the movable portion 190 of the movable cam 188 so as to be elastically locked.

Accordingly, the cam spring 206 causes the movable cam 188 to return to the original position by elastically bringing the engaging portion 198 of the movable cam 188 into contact with the abutting portion 180 of the cam member 166 to return to the original position. Apply biasing force.

When the shift and select lever 132 is moved from the reverse select position to the reverse shift position, the movable cam 188 causes the rotation of the cam member 166 from the original position in the direction of arrow D1 to the contact portion 180 and the locking portion. The notch 202 provided inside the second speed yoke portion 170 of the pair of the first speed yoke portion 168 and the second speed yoke portion 170 is blocked by the contact with the first speed yoke portion 168 and the engagement portion 19 at the tip end.
After the first-speed / second-speed shift yoke 136 is slightly moved toward the second-speed shift position by engagement with the second gear 2, the cam member 166 is moved over the one second-speed yoke portion 170 to be disengaged. It is provided so as to be rotatable.

Further, when the shift and select lever 132 is moved from the reverse shift position to the reverse select position, the cam member 188 is allowed to rotate from the original position with respect to the cam member 166 in the direction of arrow D2 to engage. The notch 2 provided between the pair of the first speed yoke portion 168 and the second speed yoke portion 170 over the one released second speed yoke portion 170 and provided inside the second speed yoke portion 170
02 so as to engage the engaging portion 192 at the distal end with the cam member 1.
66 is rotatably supported.

The movable cam 188 is, as shown in FIG.
The first-speed gear provided with the first-speed / second-speed shift yoke 136
At the position where the second speed shift shaft 142 is returned to the neutral position by the positioning mechanism 214, the second speed shift shaft 142 gets over the second speed yoke 170 and is disengaged. The positioning mechanism 214 includes a first-speed / second-speed shift shaft 1
42, a neutral positioning hole 216 and a first-speed positioning hole 218, a second-speed positioning hole 220 are provided, and a positioning spring 224 for elastically engaging a positioning ball 222 is provided in each of the holes 216 to 220.

The movable cam 188 is configured such that the positioning ball 222 of the positioning mechanism 214
Immediately before moving out of 6 and moving to the second-speed positioning hole 218 side, the vehicle gets over the second-speed yoke 170 and is disengaged. Thus, the first-speed / second-speed shift shaft 142 provided with the first-speed / second-speed shift yoke 136 is positioned by the positioning mechanism 214 when the movable cam 188 gets over the second-speed yoke portion 170 and is disengaged. When the ball 220 is pushed back into the neutral positioning hole 218 by the elastic force of the positioning spring 224, the ball 220 is returned from the second speed shift position to the neutral position.

Next, the operation of this embodiment will be described.

When the vehicle is stopped and the shift operation unit 86 is in the neutral state, the transmission 2
0 is rotated by the driving force of the internal combustion engine. But,
The counter shaft 12 has stopped rotating because the vehicle has stopped.

The reverse gear squeal preventive device 164 is provided in FIG.
As shown in the figure, the movable cam 188 is in the neutral position.
Are separated from the first-speed / second-speed shift yoke 136.
When the reverse gear squeeze preventive device 164 is operated from the neutral position to the reverse select position by the shift operation section 86, as shown in FIG.
2, the interlock plate 96 and the shift and select lever 132 move in the axial direction indicated by the arrow, and the cam member 166 adjacent to the interlock plate 96 also moves in the axial direction integrally with the shift and select shaft 92.

As shown in FIG. 12A, the shift and select lever 132 in the interlock plate 96 is
The lever member 134 is engaged with the fifth speed yoke portion 226 and the reverse yoke portion 228 of the fifth speed / reverse shift yoke 140 by moving to the reverse select position. The cam member 166 includes a pair of first and second speed yoke 136.
The second speed yoke 168 and the second speed yoke 170 are opposed to each other. The movable cam 188 is provided with a pair of first speed yoke portions 1.
68 and a notch 202 provided inside the second speed yoke 170 and located in the second speed yoke 170.
2 are engaged.

In this state, the clutch (not shown)
And operate to the reverse shift position. When the clutch is disengaged, the main shaft 10 stops transmitting the driving force of the internal combustion engine, but continues to rotate due to inertia.

When the operation from the reverse select position to the reverse shift position is started after the clutch is disengaged, the shift and select shaft 92 is rotated in the circumferential direction indicated by the arrow as shown in FIG.

The shift and select lever 132 pushes the reverse yoke portion 228 of the fifth speed reverse shift yoke 140 toward the reverse shift position by the rotation of the shift and select shaft 92, and the operation of the fifth speed reverse shift yoke 140. The reverse sleeve 64 is operated via the fifth speed / reverse shift shaft 146, the reverse gear shift arm 156, and the reverse gear shift lever 158 to make the reverse idler gear 62 mesh with the reverse main gear 36 and the reverse counter gear 70.

At this time, the cam member 166 rotates in the direction of the arrow by the rotation of the shift and select shaft 92, and the cam member 166 is rotated from its original position by the contact between the contact portion 180 and the locking portion 198. The blocked movable cam 188 is also rotated in the same direction. This allows
The movable cam 188 rotates together with the shift-and-select shaft 92 as shown in FIG.
6 by pushing the second speed yoke 170 toward the second speed shift position.
The operation of the speed synchronization mechanism 74 is started.

As a result, the rotation of the main shaft 10 starts to be synchronized with the counter shaft 12 which has stopped rotating. That is, the rotation of the main shaft 10 is controlled by the reverse idler gear 62.
The reverse main gear 36 and the reverse counter gear 7
The gear is decelerated in the initial stage of the reverse shift to engage with zero.

When the reverse shift operation is continued, the movable cam 188 which rotates together with the cam member 166 becomes
While pushing the second speed yoke 170 with the second gear 92, the second gear yoke 170 gradually moves out of the notch 202, and finally the second notch 2
02 and got over the 2nd speed yoke 170.
As shown in (C), the engagement is released.

When the movable cam 188 rides over the second speed yoke 170 and is disengaged, the positioning ball 222 of the positioning mechanism 214 moves from the neutral positioning hole 216 to the second speed positioning hole 218 as shown in FIG. Is located just before moving on.

Thus, the first / second speed shift yoke 13
When the movable cam 188 gets over the second speed yoke portion 170 and is disengaged, the first speed / second speed shift shaft 142 provided with the second gear 6 is returned to the neutral position by the positioning mechanism 214 and the second speed synchronization mechanism 74 Release the operation.

At this time, the main shaft 10 is
By the operation of the two-speed synchronization mechanism 74 in (B), the rotation has already been sufficiently decelerated or stopped.

The cam member 166 has a two-speed synchronization mechanism 74.
After the operation is stopped, the gear is rotated together with the shift and select shaft 92 by continuing the reverse shift operation. However, since the movable cam 188 has passed over the second speed yoke 170 and is disengaged, the second speed The synchronization mechanism 74 is not operated.

The shift and select lever 134
Moves to the reverse shift position due to the continuation of the reverse shift operation, and eventually the reverse idler gear 62 meshes with the reverse main gear 36 and the reverse counter gear 70.

Thus, when the reverse idler gear 62 meshes with the reverse main gear 36, the main shaft 10
Since the rotation has already been sufficiently decelerated or stopped, unpleasant reverse gear squeal can be prevented. Note that the select and shift lever 134
In this case, the tip end 114 of the plate holding bolt 112 abuts on the stopper 230 of the guide recess 162 of the guide 160 to restrict the shift stroke.

Since the operation of the second-speed synchronizing mechanism 74 has already been completed, the main shaft 10 can rotate freely. Therefore, the reverse idler gear 62 and the reverse main gear 36 can slightly rotate even when the vertexes abut, and the reverse idler gear 62 and the reverse main gear 36 can smoothly mesh with each other.

When the reverse gear squeak preventive device 164 performs an operation of returning from the reverse shift position to the reverse select position in FIG.
As shown in (A), the interlock plate 96 and the shift and select lever 132 rotate in the circumferential direction shown by the arrow together with the shift and select shaft 92, and the cam member also rotates integrally with the shift and select shaft 92.

The shift and select lever 132 pushes the fifth speed yoke portion 226 of the fifth speed and reverse shift yoke 140 toward the reverse select position by the rotation of the shift and select shaft 92, and the operation of the fifth speed and reverse shift yoke 140. 5th speed, reverse shift shaft 1
The reverse sleeve 64 is operated via the reverse gear shift arm 156 and the reverse gear shift lever 158 to release the reverse idler gear 62 from the reverse main gear 36 and the reverse counter gear 70.

At this time, the cam member 166 is rotated in the direction of the arrow by the rotation of the shift and select shaft 92, and the engaging portion 192 of the movable cam 188 is brought into contact with the second speed yoke portion 170. As shown in FIG. 13 (B), the movable cam 188 is brought into contact with the contact portion 180 against the cam spring 206 around the support shaft 204 by an engaging portion 192 abutting on the top portion 232 of the second speed yoke portion 170. Is rotated in the direction of arrow D2 away from the locking portion 198, and the cam member 166 is allowed to rotate from its original position.

As a result, the movable cam 188 is
As shown in (B), the cam member 166 rotates together with the shift-and-select shaft 92 in the direction of arrow D2 rearward with respect to the rotation direction of the cam member 166, and the engagement portion 192 is moved to the second speed yoke portion 17.
It moves between the first speed yoke portion 168 and the second speed yoke portion 170 while slidingly contacting the top portion 232 of the zero.

When the returning operation to the reverse select position is continued, the first speed yoke portions 168 and 2 are rotated while rotating in the direction of arrow D2 with respect to the original position of the cam member 166 while slidingly contacting the top portion 232 of the second speed yoke portion 170. The movable cam 188 moving between the speed yoke portions 170 eventually gets over the top portion 232 of the second speed yoke portion 170.

The movable cam 188 having passed over the top 232 of the second speed yoke 170 is rotated in the direction of arrow D1 by the cam spring 206 as shown in FIG. Located between
The engaging portion 192 is engaged with the notch 202 of the second speed yoke 170.

The shift and select lever 134
Is moved to the reverse select position by continuing the reverse shift operation, and finally the reverse idler gear 62
The reverse main gear 36 and the reverse counter gear 7
It will be separated from zero.

The reverse gear squeal preventive device 164 is provided in FIG.
In the reverse select position, the movable cam 188 is moved to the first speed yoke portion 168 and the second speed yoke portion 17 as shown in FIG.
0, and the engaging portion 192 is engaged with the notch 202 of the second speed yoke portion 170. When the shift operation portion 86 is operated to the neutral position from this state, as shown in FIG. Is the 1st and 2nd speed shift yoke 13
6 away.

The shift and select lever 132
When the gear is operated from the reverse select position to the neutral position by the speed change operation unit 86, the gear is disengaged from the fifth speed yoke part 226 and the reverse yoke part 228 of the fifth speed / reverse shift yoke 140.

As described above, when the shift and select lever 132 is moved from the reverse select position to the reverse shift position, the reverse gear squeal prevention device 164 has a pair of first speed yoke portions of the first speed / second speed shift yoke 136. The movable cam 188 located between the 168 and the second speed yoke 170 is prevented from rotating from its original position with respect to the cam member 166, and is engaged with the second speed yoke 170 to move the first and second speed shift yokes 136 to two. After slightly moving to the speed shift position, the engagement is released by getting over the second speed yoke portion 170.

As a result, the reverse gear squeal prevention device 1
In the initial stage of the reverse shift, the rotation of the movable gear 164 is prevented from rotating with respect to the cam member 166, and the second speed synchronizing mechanism 74 can be reliably operated by the stroke of the movable cam 188 moving with the cam member 166. 2-speed synchronization mechanism 7
4, the rotation of the main shaft 10 can be stopped, and reverse gear squeal can be prevented.

Therefore, the reverse gear squeak prevention device 164 can surely prevent the reverse gear squeal regardless of the shaft rotation speed and the shift load, and can be operated in transmissions having different shaft rotation speeds and shift loads. Since the second-speed synchronizing mechanism 74 can be operated with a small allowance by the stroke of the cam 188, it can be applied to transmissions having different configurations, and the versatility can be increased.

The reverse gear squeak prevention device 16
4 moves the shift and select lever 132 from the reverse shift position to the reverse select position.
The movable cam 188 that has passed over the second speed yoke 170 is allowed to rotate from its original position with respect to the cam member 166, and has passed over the disengaged second speed yoke 170 and a pair of first speed yoke 168 and second speed It will be located between the yoke parts 170.

As a result, when the reverse gear squeak prevention device 164 returns to the reverse select position, the movable cam 188 is not locked by the second speed yoke portion 170, and the pair of first speed yoke portions 168 and Speed yoke section 170
You can go back in time.

The movable cam 188 of the reverse gear squeak prevention device 164 has a first-speed / second-speed shift shaft 142 provided with a first-speed / second-speed shift yoke 136.
At the position returned to the neutral position by
Since the engagement is released so as to get over the speed yoke portion 170, the second speed synchronization mechanism 74 that has been operated at the beginning of the reverse shift can be reliably released.

Further, the second speed yoke 170 is provided with a notch 202 with which the engaging portion 192 at the tip of the movable cam 188 is engaged, so that the movable cam 188 and the second speed yoke 17
0 can be reliably engaged.

Further, the movable cam 188 includes the cam member 1.
When it is allowed to rotate from its original position with respect to 66 and is positioned between the first speed yoke portion 168 and the second speed yoke portion 170 over the disengaged second speed yoke portion 170, it is returned to its original position. By providing the cam spring 206, it is possible to reliably return to the original position with respect to the cam member 166.

Therefore, the reverse gear squeak prevention device 164 can ensure the reliability of the reverse gear squeal prevention operation without affecting the operation of the second speed synchronization mechanism 74.

[0098]

As described above, in the reverse gear squeal prevention device of the present invention, the rotation of the movable member, which is prevented from rotating with respect to the cam member at the beginning of the reverse shift and moves together with the cam member, is synchronized with the forward gear. Can be reliably operated for a short time, the rotation of the main shaft can be stopped by the synchronizing action of the forward-stage synchronizing mechanism, and gear squeal of the reverse gear can be prevented.

For this reason, the reverse gear squeal prevention device can surely achieve the reverse gear squeal prevention regardless of the shaft rotation speed and the shift load, and can be used even in transmissions having different shaft rotation speeds and shift loads. The stroke of the forward-stage synchronizing mechanism can be reliably operated with a small stroke, so that the present invention can be applied to transmissions having different configurations.

Further, the reverse gear squealing device can surely release the forward gear synchronizing mechanism that was operated at the beginning of the reverse shift, and can reliably engage the movable cam with one of the yoke portions. Thus, it is possible to reliably return to the original position with respect to the cam member.

Therefore, the reverse gear squeak prevention device can ensure the reliability of the reverse gear squeal prevention operation without affecting the operation of the forward gear synchronization mechanism.

[Brief description of the drawings]

FIG. 1 is a side view of a shift operation portion showing an embodiment of a reverse gear squeal prevention device according to the present invention.

FIG. 2 is a side view of a shift operation unit in a state where the shift operation unit has been operated to a reverse select position.

FIG. 3 is a plan view of a speed change operation unit.

FIG. 4 is an enlarged front view of a positioning mechanism provided on a first speed / second speed shift shaft.

FIG. 5 is a sectional view of a transmission.

FIG. 6 is an enlarged side view of a cam member and a movable cam.

FIG. 7 is a side view of a cam member and a movable cam.

FIG. 8 is a plan view of a cam member and a movable cam.

FIG. 9 is a plan view of a cam spring.

FIG. 10 is a plan view of a cam member.

FIG. 11 is a plan view of a movable cam.

12A and 12B show an operation state from a reverse select position to a reverse shift position, where FIG. 12A is a bottom view at the reverse select position, FIG. 12B is a bottom view showing a state where the reverse select position is slightly operated, and FIG. FIG. 4 is a bottom view at the reverse shift position.

13A and 13B show an operation state from a reverse shift position to a reverse select position, where FIG. 13A is a bottom view at the reverse shift position, FIG. 13B is a bottom view of a state where the reverse shift position is operated, and FIG. It is a bottom view in a selection position.

[Explanation of symbols]

 Reference Signs List 2 transmission 4 gear train 8 transmission case 10 main shaft 12 counter shaft 14 reverse idler shaft 36 reverse main gear 62 reverse idler gear 70 sleeve gear 92 shift and select shaft 96 interlock plate 132 shift and select lever 136 1st speed, 2nd speed Shift yoke 138 Third speed / fourth speed shift yoke 140 Five speed / reverse shift yoke 164 Reverse gear squeak prevention device 166 Cam member 188 Movable cam 192 Engaging portion 202 Notch portion 206 Cam spring

Claims (4)

[Claims] A shift-and-select shaft that is axially moved at the time of selection and circumferentially moved at the time of shift by operating a shift lever is provided, and a shift-and-select lever is attached to the shift-and-select shaft and provided. In a reverse gear squeak prevention device for preventing a gear squeal by operating a forward gear synchronizing mechanism for a short time when the select lever is moved from a reverse select position to a reverse shift position, the shift and select shaft is provided with the shift and select lever in reverse. A cam member which is opposed to a pair of yoke portions of the forward gear shift yoke for operating the forward gear synchronizing mechanism when moved to the select position is provided, and the shift and select lever is attached to the cam member by the reverse select position. When moved to A movable cam positioned between the gear members is pivotally provided to prevent rotation of the cam member from its original position when the shift and select lever is moved from the reverse select position to the reverse shift position. Then, the engagement with one of the pair of yoke portions causes the forward shift yoke to slightly move to the forward shift position side, and then, over the one yoke portion, the engagement is released. When the shift and select lever is moved from the reverse shift position to the reverse select position, the cam member is allowed to rotate from the original position and rides over the one of the disengaged yoke portions to move over the one yoke portion. A reverse gear squeal prevention device, which is rotatably supported on the cam member so as to be located between the portions. 2. The movable cam moves over one of the pair of yoke members at a position where a forward shift shaft provided with the forward shift yoke is returned to a neutral position by a positioning mechanism. The reverse gear squeal prevention device according to claim 1, wherein the reverse gear is provided so as to cancel the engagement. 3. The reverse according to claim 1, wherein one of the yoke portions of the pair of yoke members is provided with a cutout portion with which an engaging portion at the tip of the movable cam engages. Gear squeal prevention device. 4. The reverse according to claim 1, wherein the movable cam is provided with a cam spring for urging the movable cam to return to the original position when rotated from the original position with respect to the cam member. Gear squeal prevention device.