JPH05332450A - Gear noise preventing mechanism for reverse gear shift - Google Patents

Abstract

PURPOSE:To prevent the generation of gear noise with the simple structure, and reduce the number of parts to make the whole body compact and light, and secure the synchronism, and improve the compatibility with the specification, which does not have the gear noise preventing mechanism. CONSTITUTION:A gear noise preventing mechanism, which stops the rotation of a reverse idler gear 102 with the inertia rotation of a main shaft 10 at the initial time of the reverse shift operation and which allows the rotation of the reverse idler gear at the end of that operation, is provided between a reverse idler shaft 100 and a reverse gear shift yoke. One end of a reverse gear shift arm 156 is supported freely to turn, and the other end thereof is provided with a cam part 170, and the periphery of the reverse idler gear base part is formed with the taper surface, and a synchronizer ring is fitted thereto, and a reverse idler sleeve 42, in which a sleeve dog part for abutting and separating to/from a ring dog part of the synchronizer ring is provided, is provided in the periphery of the reverse idler gear base part, and furthermore, the cam pushing surface is provided in the reverse idler sleeve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverse gear shift gear noise prevention mechanism, and more particularly to a reverse gear shift reverse gear shift prevention mechanism capable of preventing generation of gear noise at the time of reverse shift with a simple construction in a manual transmission of a sliding type. Gear sound prevention mechanism.

[0002]

2. Description of the Related Art A vehicle is equipped with a manual or automatic transmission in order to convert the power of an internal combustion engine into a desired one in accordance with a running condition and take it out. Such transmissions include gear type transmissions and belt type transmissions, and gear type transmissions with low power transmission loss are often used.

A gear type manual transmission has a plurality of speed change gear trains, and the gear trains are switched by a shift lever to engage the gears of the respective stages, so that the power of the internal combustion engine is adjusted according to the running conditions. I convert it to the required one and take it out.

In such a gear type manual transmission, there are, for example, a selective sliding type and a constantly meshing type, depending on the method of switching the gear ratio.

The selective sliding type manual transmission includes a main shaft which is connected to and disconnected from the internal combustion engine by a clutch on the internal combustion engine side, a counter shaft which is arranged substantially parallel to the main shaft, and a reverse shaft which is arranged substantially parallel to the main shaft. Each has a gear on the idler axis,
The reverse idler gear of the reverse idler slides and meshes with the reverse main gear of the main shaft and the reverse counter gear of the counter shaft to transmit power, and the reverse idler gear is configured to be operated even when the vehicle is stopped. ing.

Further, in the always meshing type manual transmission, the gear pairs corresponding to the required number of gears are constantly meshed, and the structure in which the shaft and the gears are allowed to idle and the gear pair having the necessary gear ratio is obtained. Is fixed to the shaft with a coupling sleeve on the shaft to transmit torque.

However, in the selective sliding type manual transmission, the counter reverse 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 slide on the reverse idler shaft. Is engaged through the reverse idler gear, which is why
There are drawbacks such as squealing gears and giving discomfort, and damage to each part to shorten the life.

More specifically, as shown in FIGS. 19 to 21, in the conventional selective sliding automatic transmission 202, the reverse idler gear 204 is mounted on the reverse idler shaft 206 as shown in FIG. It can rotate freely (free state), and continues to rotate by inertia even after the main shaft 206 disengages a clutch (not shown).

When the reverse shift operation is started, the operating force from the shift lever (not shown) is transmitted to the reverse gear shift arm 212 by the reverse gear shift yoke 210 as shown in FIG. 23, and the operation of the reverse gear shift arm 212 is performed. The reverse idler gear 204 causes the reverse main gear 2 of the main shaft 208 to
The reverse idler gear 204 starts to mesh with the reverse main gear 214. At this time, since the main shaft 208 is still rotating, the reverse idler gear 204 is also rotating. However, since the reverse idler gear 204 is in the free state, no gear noise is generated when the reverse idler gear 204 meshes with the reverse main gear 214.

However, when the reverse shift arm 212 continues to push the reverse idler gear 204, the reverse idler gear 204 contacts the reverse counter gear 218 of the counter shaft 216, as shown in FIG.
At this time, since the counter shaft 216 is connected to the axle via the final reduction gear mechanism 210, it cannot rotate. Therefore, the rotating reverse idler gear 20 is rotating.
The contact between No. 4 and the reverse counter gear 218 that is stationary causes gear noise.

In order to prevent the occurrence of the gear squeal, there is a device provided with a gear squeal prevention mechanism for stopping the rotation of the main shaft 216 between the operations shown in FIGS.

As shown in FIG. 24, the reverse idler gear 204 must be able to rotate freely at the moment when the reverse idler gear 204 and the reverse counter gear 218 mesh with each other. This is the reverse idler gear 204
This is for rotating the reverse idler gear 204 and meshing with the reverse counter gear 218 when the phases of the reverse counter gear 218 do not match.

In order to prevent the occurrence of this gear noise,
As with the other gears, the synchronizing device may be provided as a constant mesh type, but it has the drawbacks of increased weight and increased cost.

In order to solve this drawback, a simple synchronizer has been used which simply stops the rotation of the main shaft before the reverse idler gear meshes with the reverse counter gear.

That is, conventionally, at the time of reverse shift operation,
A configuration in which the rotation of the main shaft is stopped by lightly actuating a synchronizing device for other gears such as a second speed gear, or a reverse synchronizing device is provided outside the fifth speed gear of the main shaft to provide a transmission case or a counter shaft. It has been conceived that a structure in which the rotation of the main shaft is stopped by synchronizing the main shaft with a dedicated gear that meshes with the reverse counter gear of the above.

A gear noise suppression device for such a transmission is disclosed, for example, in Japanese Utility Model Publication No. 57-17163. The one disclosed in this publication is provided with a spacer slidably fitted on the counter shaft and located on the side surface of the counter gear, and a spring is provided between the transmission case and the spacer in a compressed state to provide a spring. By pressing the spacer against the side surface of the counter gear to generate drag torque on the counter gear,
The counter gear is also pressed to the other side in the axial direction to prevent gear noise.

[0017]

However, conventionally, in the method of using another gear synchronizer in order to prevent the occurrence of gear squeal, a complicated link mechanism and parts such as springs are required, and Since the synchronizer is actuated via the repulsive force of the spring, there is a disadvantage that the gear cannot be sufficiently synchronized and the gear squeal cannot be sufficiently reduced in the case of quick shift operation.

When a dedicated synchronizing mechanism is provided outside the fifth speed gear, the total length of the transmission is increased and the weight is increased, and a dedicated gear is added or the inner surface of the side case is synchronized. It was necessary to do processing for the device.

Therefore, in order to prevent the occurrence of gear squeal, when using other gears or providing a dedicated synchronizing device, the number of parts becomes large, and the transmission case is also processed. In addition, when changing from a transmission having a specification that does not have a gear squeal preventing mechanism at the time of reverse shift, there is a disadvantage that existing parts must be changed significantly.

[0020]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention firstly arranges a main shaft, a counter shaft, and a reverse idler shaft in a transmission case substantially in parallel, A reverse main gear is provided on the main shaft, a reverse counter gear is provided on the counter shaft, a reverse idler gear is provided on the reverse idler shaft, and the reverse idler gear is operated by the operation of a reverse gear shift arm connected to a reverse gear shift yoke during reverse shift. In a transmission that slides on the reverse idler shaft to mesh with the reverse main gear and the reverse counter gear, the rotation of the reverse idler gear accompanying the inertial rotation of the main shaft is stopped and the reverse shift is performed at the initial stage of the reverse shift operation. Reverse at the end of operation Characterized in that the gear noise prevention mechanism to permit rotation of Idoragiya provided between the reverse gear shift yoke and the reverse idler shaft.

Secondly, the main shaft, the counter shaft, and the reverse idler shaft are arranged substantially in parallel in the transmission case, the main shaft is provided with a reverse main gear, the counter shaft is provided with a reverse counter gear, and A reverse idler gear is installed on the reverse idler shaft, and the reverse idler gear is slid on the reverse idler shaft by the operation of the reverse gear shift arm that is connected to the reverse gear shift yoke during reverse shift to mesh with the reverse main gear and the reverse counter gear. In the transmission, the rotation of the reverse idler gear due to the inertial rotation of the main shaft is stopped in the initial stage of the reverse shift operation, and at the end of the reverse shift operation, the rotation of the reverse idler gear is allowed so that the reverse gear shift arm is rotated. A cam portion is provided on the other end side of the reverse shift arm while supporting the end side, and a taper surface is formed on the outer periphery of the reverse idler gear base portion of the reverse idler gear, and a synchronizer ring is fitted on the taper surface. A reverse idler sleeve provided with a sleeve dog portion that contacts and separates from the ring dog portion of the synchronizer ring is rotatably slidably provided on the outer periphery of the reverse idler gear base portion, and the reverse gear shift arm operates as the reverse gear shift yoke. A gear squeal preventing mechanism is configured by providing a cam pressing surface on the reverse idler sleeve with which the cam portion comes into contact with and separates from each other when being swung by.

[0022]

According to the structure of the present invention, first, during reverse shift, inertial rotation of the main shaft can be stopped by the gear noise prevention mechanism on the reverse idler shaft to prevent gear noise. Therefore, the gear squeal prevention mechanism is simply provided on the reverse idler shaft, the structure is simple, and the main shaft and the like are not required to be extended.
No additional gears are required, the number of parts can be reduced, the transmission can be made smaller and lighter, and additional parts such as a dedicated link mechanism and springs are not required.
Easy to assemble. Secondly, since the gear squeal preventing mechanism is composed of parts such as a synchronizer ring and an idler sleeve, the squeal does not occur even in the case of quick gear shifting and the gear squeal preventing mechanism. Compatibility with specifications that do not have can also be improved.

[0023]

Embodiments of the present invention will now be described in detail and specifically with reference to the drawings. 1 to 18 show an embodiment of the present invention. In FIGS. 1 and 2, 2 is a selective sliding automatic transmission (hereinafter simply referred to as “transmission”), 4 is a gear portion, 6 is a shift operation portion, and 8 is a transmission case. In the transmission case 8, a main shaft 10 and a counter shaft 12 in which power from an internal combustion engine (not shown) is intermittently connected by a clutch (not shown) and a counter shaft 12 are substantially parallel to each other in the longitudinal direction of the transmission 2. It is installed in.

The main shaft 10 is held by the first main shaft bearing 18 held by the right wall portion 16 of the light case 14 of the transmission case 8 and the left wall portion 22 of the left case 20 of the transmission case 8. It is rotatably supported by the second main shaft bearing 24.

The counter shaft 12 is rotated by a first counter shaft bearing 26 held by the right wall portion 16 of the right case 14 and a second counter shaft bearing 28 held by the left wall portion 22 of the left case 20. Supported as possible.

The main shaft 10 has a first-speed main gear 30, a reverse main gear 32, and a second main gear 32 in order from the internal combustion engine side.
The third main gear 36, the fourth main gear 38, and the fifth main gear 42 are rotatably provided in the side case 40 of the transmission case 8 while the third main gear 34 is fixedly provided.

A final drive gear 46 constituting a final reduction mechanism 44 is fixed to the counter shaft 12 in order from the internal combustion engine side, and a first speed counter gear 48 and a second speed main gear 34 with which the first speed main gear 30 meshes. Is rotatably provided with a second speed counter gear 50 that meshes with the third speed counter gear 5 that meshes with a third speed main gear 36.
The fourth speed counter gear 5 in which the second and fourth speed main gears 38 mesh with each other
The fourth gear and the fifth gear counter gear 56 meshing with the fifth gear main gear 42 are fixedly provided in the side case 40.

The final drive gear 46 meshes with the final driven gear 60 of the differential portion 58.

The right case 14 and the left case 20.
And are connected by a first mounting bolt 62.
In addition, the left case 20 has a second side case 40.
It is mounted by mounting bolts 64.

The counter shaft 12 between the first speed counter gear 48 and the second speed counter gear 50 has a first speed / second speed hub 66.
Is fixedly provided. The first-speed / second-speed hub 66 is integrally provided with a reverse counter gear 68 and a first-speed / second-speed sleeve 70 so as to be moved in the axial direction of the counter shaft 12. This 1st speed / 2nd speed sleeve 70
The first and second speed forks (not shown) that engage with the first and second speed sleeve grooves 72 are operated to operate the first and second speed synchronizing mechanism 74 having a synchronizer ring for the first and second speeds. is there.

A third-speed / fourth-speed hub 76 is fixedly provided on the main shaft 10 between the third-speed main gear 36 and the fourth-speed main gear 38. In this 3rd speed / 4th speed hub 76,
A third speed sleeve and a fourth speed sleeve 78 are provided to be moved in the axial direction of the main shaft 10. This 3rd / 4th sleeve 7
Reference numeral 8 is a third-speed / fourth-speed synchronizing mechanism 8 which is operated by a third-speed / fourth-speed fork (not shown) engaged with the third-speed / fourth-speed sleeve groove 80 and has a synchronizer ring for the third-speed / fourth speed.
2 is operated.

Further, in the side case 40, a 5-speed hub 84 is fixedly provided on the main shaft 10, and the 5-speed hub 84 is moved in the axial direction of the main shaft 10 to move to the 5-speed main gear 42. A 5-speed sleeve 86 for connecting and disconnecting is provided. The fifth-speed sleeve 86 is operated by a fifth-speed fork (not shown) that engages with the fifth-speed sleeve groove 88, and operates the fifth-speed synchronizing mechanism 90 having a fifth-speed synchronizer ring.

A holding wall portion 94 is attached to the left case 20 by a third attaching bolt 92 substantially in parallel with the right wall portion 16. The shaft support portion 96 attached to the holding wall portion 94 and the shaft support hole 9 formed in the light wall portion 16
A reverse idler shaft 100, which is arranged substantially parallel to the main shaft 10, is supported on the shaft 8.

A reverse idler gear 102 is provided on the reverse idler shaft 100. A pin engaging groove 106 is formed in a reverse idler gear base portion 104 of the reverse idler gear 102. The reverse idler gear 102 is movable on the reverse idler shaft 102 in the axial direction of the reverse idler shaft 100, and is provided so as to mesh / disengage with the reverse main gear 32 and the reverse counter gear 68.

As shown in FIG. 2, in the shift operation portion 6, a first speed / second speed shift yoke 108, a third speed / fourth speed shift yoke 110, and a fifth speed / reverse shift yoke 112 are arranged in parallel. These first and second speed shift yokes 10
Although not shown, one end side of each of the 8th, 3rd speed / 4th speed shift yoke 110 and the 5th speed / reverse shift yoke 112,
A shift-and-select lever that operates with the operation of the shift-and-select shaft is selectively engaged.

A first-speed / second-speed shift shaft 114 is provided on the other end side of the first-speed / second-speed shift yoke 108. The first and second speed shift shafts 114 are provided with first and second speed forks (not shown) that engage with the first and second speed sleeve grooves 72.

A third speed / fourth speed shift shaft 116 is provided on the other end side of the third speed / fourth speed shift yoke 110. The third and fourth speed shift shafts 116 are provided with third and fourth speed forks (not shown) that engage with the third and fourth speed sleeve grooves 80.

A fifth speed / reverse shift shaft 118 is provided on the other end side of the fifth speed / reverse yoke 112.
The fifth speed / reverse shift shaft 118 is provided with a fifth speed fork (not shown) that engages with the fifth speed sleeve groove 88.

A fifth speed / reverse guide shaft 120 is provided in parallel with the fifth speed / reverse shift shaft 118.

The fifth speed / reverse guide shaft 120 and the fifth speed / reverse shift shaft 118 are provided with one end 122a of a reverse gear shift yoke 122.

The other end portion 122b of the reverse gear shift yoke 122 is extended to the reverse idler gear 102 side.

Between the other end portion 122b of the reverse gear shift yoke 122 and the reverse idler gear 102, the rotation of the reverse idler gear 102 due to the inertial rotation of the main shaft 10 is stopped at the beginning of the reverse shift operation, so that the main shaft is stopped. A gear squeal preventing mechanism 124 is provided which stops the rotation of 10 and allows the rotation of the reverse idler gear 102 at the end of the reverse shift operation.

That is, in the reverse idler gear 102, as shown in FIG. 3, a gear recess 126 is formed on one surface side, and the diameter gradually increases from the pin engagement groove 106 side into the gear recess 126. A tapered surface 128 is formed as a friction surface. A sliding surface 130 formed on the outer circumference of the reverse idler gear base 104 is provided continuously with the tapered surface 128 in parallel with the main shaft 10.

A synchronizer ring 132 is provided in contact with the tapered surface 128 as shown in FIGS. This synchronizer ring 132 has a tapered surface 12.
8 and the ring base 134 that contacts 8 and the reverse idler gear 1
And a ring dog portion 136 that is oriented in the radial direction within the gear recess 126 formed in No. 02. This ring dog part 1
As shown in FIG. 7, a ring locking piece 138 that is oriented in the axial direction is formed on the 36, and a plurality of ring slopes 140 are formed.
Are formed.

Further, as shown in FIGS. 3 and 5, a reverse idler sleeve 142 is rotatably slidably provided on the sliding surface 130. The reverse idler sleeve 142 includes a sleeve base portion 144 that contacts the sliding surface 130 and a sleeve dog portion 146 that joins the ring dog portion 136. In this sleeve dog part 146,
As shown in FIG. 7, a sleeve locking piece 148 with which the ring locking piece 138 is locked and a sleeve slope 150 contacting the ring slope 140 are formed. The ring engaging groove piece 138 is disposed between the engaging piece plane 152 which is a straight surface of the sleeve engaging piece 148 and the sleeve step surface 154 which is separated from the engaging piece plane 152 by the rotation range D, and , Overlapped with the sleeve locking piece 148 by the overlapping distance Y.

The reverse gear shift arm 1 is brought close to the sleeve base 144 of the reverse idler sleeve 142.
56 are provided.

This reverse gear shift arm 156 is
As shown in FIGS. 4 and 5, one end of the arm body 158 is swingably provided on the support 162 by the arm mounting pin 160. This support 162 is a support attachment pin 1
It is attached to the light wall portion 16 by 64 and 164.

A reverse engagement pin 166 that engages with the pin engagement groove 106 is attached to the other end of the arm body 158, and is provided on the back surface of the sleeve dog portion 146 of the reverse idler sleeve 142. Further, the cam portion 170 is continuously provided so as to face the cam pressing surface 168 side. As shown in FIG. 6, when the cam center C1 is oriented downward from the horizontal direction, the cam portion 170 has a distance L from the outer peripheral surface of the reverse engagement pin 166 to the front end surface, and rotates. When the cam center C1 is oriented in the horizontal direction, it is extended by the cam distance X. The relationship between the cam distance X and the overlapping distance Y is Y> X.

A long hole 172 for inserting a yoke is formed in the central portion of the arm body 158 in the longitudinal direction of the arm body 158. This long hole 17 for inserting the yoke
The other end portion 122b of the reverse gear shift yoke 122 is inserted through 2.

Further, the reverse gear shift arm 15
6 is provided with a sleeve rotation stop flat portion 174.

That is, in the gear squeal preventing mechanism 124, the reverse idler gear 102 is rotatable and slidable on the reverse idler shaft 100, and the reverse idler sleeve 142 is rotatable and slidable on the reverse idler gear base 104. There is a reverse gear shift arm 1
Since the sleeve rotation stopping flat portion 174 is suppressed by 56, the reverse idler gear 102 can move only in the axial direction with respect to the light wall portion 16, and also in the axial direction, the cam portion 170 of the reverse gear shift arm 156. Is in contact with the cam pressing surface 168 on the back surface of the sleeve dog portion 146 of the reverse idler sleeve 142, so that the reverse idler sleeve 142 can move only in a small portion between the synchronizer ring 132 and the reverse gear shift arm 156. is there.

Further, at the time of reverse shift, the idler sleeve 142 pressed by the cam portion 170 by the rotation of the reverse gear shift arm 156 moves the synchronizer ring 13 via the sleeve slope 150 and the ring slope 140.
2 is pressed against the reverse idler gear 102, and the reverse idler gear 102 and the reverse idler sleeve 142
The rotation of the reverse idler gear 102 is stopped in synchronization with each other.

Further, the rotation of the synchronizer ring 132 with respect to the reverse idler sleeve 142 is limited by the sleeve engaging piece 148 as shown in FIG. 5, and is limited to the angle of one tooth of the ring dog portion 136 in the rotation range D. It Further, unlike the normal synchronizing mechanism, the reverse idler sleeve 142 presses the synchronizer ring 132 and returns after synchronizing, so that parts such as keys are not necessary.

Next, the operation of this embodiment will be described with reference to FIGS.

8 and 9, the reverse idler gear 102 is pushed at the initial stage of the reverse shift operation. The main shaft 10 rotates due to inertia even after the clutch is disengaged. Then, by a reverse shift operation using a shift lever (not shown), the yoke insertion slot 172 of the reverse gear shift arm 156 is inserted.
The other end 122b of the reverse gear shift yoke 122 inserted into the reverse gear shift arm 122 is moved to the reverse idler gear 102 side in the left side of FIGS.
Starts rotating clockwise around the arm mounting pin 160 in FIG. The reverse engagement pin 166 on the other end side of the arm body 158 pushes the side surface of the pin engagement groove 106 of the reverse idler gear base 104 to reverse the reverse idler gear 102.
Is moved to the left in FIG. At this time, since the cam portion 170 does not press the reverse idler sleeve 142 and the synchronizer ring 132, the reverse idler sleeve 142 and the synchronizer ring 132 are freely rotated.

10 and 11, the cam portion 170 of the reverse gear shift arm 156 further rotates, the cam center C1 of the cam portion 170 is located in front of the axis C2 of the reverse idler shaft 100, and the reverse idler gear 102 is rotated.
Is a state in which it moves to the reverse main gear 32 side and starts to mesh with the reverse main gear 32, that is, a state in which synchronization is started. In this case, since the reverse idler gear 102 is rotatable on the reverse idler shaft 100, no gear squeal does not occur even if the reverse idler gear 102 meshes with the reverse main gear 32, and the reverse idler gear 102 reverses with the inertial rotation of the main shaft 10. The idler gear 102 starts rotating.

Then, the ring base portion 134 of the synchronizer ring 132 is pulled in the rotational direction of the reverse idler gear 102 by the friction with the tapered surface 128, and the rotation of the synchronizer ring 132 causes the ring dog portion 136 to rotate, as shown in FIGS. While sliding on the ring slope 140 of FIG.
Press to the right of 6. At this time, since the reverse idler sleeve 142 is in the free state, it moves to the right in FIG. 10, and the ring dog portion 13 of the synchronizer ring 132 is moved.
6 is the sleeve dog portion 146 of the idler sleeve 138.
It contacts the locking piece flat surface 152 which is a straight surface, and the rotation of the synchronizer ring 132 stops at this portion.

Then, the reverse gear shift arm 156
When is further rotated, as shown in FIG.
The distance L between the tip surface of the and the reverse engaging pin 166 is the distance X
Therefore, the reverse gear shift arm 156 is sandwiched between the groove side surface of the reverse engagement pin 166 and the back surface of the idler sleeve 142 and cannot rotate any more. That is, FIG.
As shown in FIG. 7, the cam portion 170 strongly presses the reverse idler sleeve 142 to the left, and the reverse idler sleeve 142 causes the sleeve dog portion 146 to move toward the sleeve slope 1
The synchronizer ring 132 is pressed against the reverse idler gear 102 via 50. As a result, the frictional force between the synchronizer ring 132 and the tapered surface 128 of the reverse idler gear 102 becomes larger than the inertial rotational force between the reverse idler gear 102 and the main shaft 10, and the rotation between the reverse idler gear 102 and the main shaft 10 is increased. To stop.

Next, when the rotation of the reverse idler gear 102 is stopped, the rotating force of the synchronizer ring 132 is also lost as shown in FIGS. 12 and 13, so that the synchronizer ring 132 and the reverse idler gear 102 pushed by the dog slopes are the original. 18, the idler sleeve 142 moves to the left along each dog slope, and the reverse gear shift arm 156 can again rotate clockwise as shown in FIG.

Further, the reverse gear shift arm 156 rotates, the reverse engagement pin 166 pushes the pin engagement groove 106 of the reverse idler gear 102, and the reverse idler gear 102 continues to move to the left. Due to the rotation of the reverse gear shift arm 156, the cam portion 170 does not press the cam pressing surface 168 on the back surface of the reverse idler sleeve 142 as shown in FIGS. 14 and 15, and the reverse idler sleeve 142 and the synchronizer ring 132 are free again. It becomes a rotation state. Further, since the reverse idler gear 102 does not rotate and meshes with the reverse counter gear 68, gear noise does not occur. The friction force between the reverse idler gear 102 and the synchronizer ring 132 is almost eliminated, and the reverse idler gear 102 is free to rotate. Therefore, even when the teeth of the reverse counter gear 68 and the teeth of the reverse idler gear 102 come into contact with each other, the reverse idler gear 102 can rotate with the main shaft 10 and does not interfere with meshing. This allows
The shift to reverse is completed (see FIGS. 14 and 15).

Then, the clutch is engaged and the main shaft 1
0 rotates again, and the reverse idler gear 102 also rotates. At this time, the reverse idler sleeve 142 is
The cam portion 170 is not in contact with the cam pressing surface 168 of the reverse gear shift arm 156. The synchronizer ring 132 is slightly pulled in the same direction as the reverse idler gear 102 by the friction of the tapered surface 128, but stops at the engaging piece flat surface 152 of the straight portion of the sleeve dog portion 146 of the reverse idler sleeve 142.
The reverse idler sleeve 142 is not pushed in the axial direction by the force from the reverse idler gear 102.

The operation of the gear squeal preventing mechanism 124 is as follows.
It is shown in Table 1.

[Table 1]

On the other hand, when the vehicle is shifted from reverse to neutral and back, the above operation is reversed.

As a result, the shapes of the reverse idler gear 102 and the reverse shift arm 156 are changed, and the synchronizer ring 132 and the reverse idler sleeve 14 are changed.
Just add 2, without changing other parts,
With a simple configuration, gear rattle of the transmission 2 can be prevented.

Further, as shown in FIG. 1, since it is not necessary to extend each shaft or add a gear, the number of parts can be reduced, and the gear squeal preventing mechanism 124 can be housed in the normal transmission case 8. The machine case 8 can be reduced in size and weight and can be easily assembled.

Further, since the force pushing the synchronizer ring 132 does not depend on the spring, it is not affected by the speed of the shift operation.

Furthermore, since the synchronizer ring 132 is exclusively used for reverse, an optimum value can be selected for the specifications of the taper angle, dog slope, etc., so effective synchronization is possible, and synchronization is ensured even during quick gear shifting operations. Generation of gear noise can be prevented.

Further, the structure of this embodiment can be easily applied to a transmission having a specification without a gear squeal preventing mechanism, and the compatibility is high.

[0069]

As is apparent from the above detailed description, according to the present invention, first, the rotation of the reverse idler gear due to the inertial rotation of the main shaft is stopped at the beginning of the reverse shift operation, and the reverse shift operation is completed at the end. Is equipped with a gear noise prevention mechanism that allows the rotation of the reverse idler gear between the reverse idler shaft and the reverse gear shift yoke, which simplifies the configuration and eliminates the need to extend the main shaft. It is not necessary, the number of parts can be reduced, the overall size and weight can be reduced, and additional parts such as a dedicated link mechanism and springs are not necessary, and assembly can be facilitated.

Secondly, in order to stop the rotation of the reverse idler gear accompanying the inertial rotation of the main shaft at the beginning of the reverse shift operation and allow the rotation of the reverse idler gear at the end of the reverse shift operation, the reverse gear shift arm A cam portion is provided on the other end side of the reverse shift arm while supporting one end side, and a taper surface is formed on the outer periphery of the reverse idler gear base portion of the reverse idler gear.
A reverse idler sleeve provided with a synchronizer ring fitted on the tapered surface and equipped with a sleeve dog that comes in contact with and separates from the ring dog of the synchronizer ring is rotatably slidable on the outer periphery of the reverse idler gear base, and the reverse gear shift arm reverses. By providing the reverse idler sleeve with a cam pressing surface that the cam part comes into contact with and separates from when the gear shift yoke is swung by the operation of the gear shift yoke, a gear noise prevention mechanism is configured, so that the gear noise prevention mechanism functions as a synchronizer ring or a reverse idler sleeve. Since it is made up of parts, it is possible to ensure synchronization and to prevent gear squeaking even in a quick gear shifting operation, and also to improve compatibility with a specification having no gear squeal preventing mechanism.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a gear unit of a transmission.

FIG. 2 is a configuration diagram of a shift operation unit of the transmission.

FIG. 3 is a side view of a gear noise prevention mechanism.

FIG. 4 is a plan view of a gear noise prevention mechanism indicated by arrow 〓 in FIG.

5 is an enlarged view of a main part of FIG.

FIG. 6 is an explanatory diagram of an operation of a cam portion.

FIG. 7 is an explanatory diagram of a ring dog portion and a sleeve dog portion.

FIG. 8 is a plan view of an initial state of reverse shift.

FIG. 9 is a side view showing an initial state of reverse shift.

FIG. 10 is a plan view showing a state where a reverse shift has been advanced.

FIG. 11 is a side view showing a state where a reverse shift has been advanced.

FIG. 12 is a plan view showing a state in which a reverse shift is further advanced.

FIG. 13 is a side view showing a state where the reverse shift is further advanced.

FIG. 14 is a plan view showing a state in which reverse shift is completed.

FIG. 15 is a side view of the reverse shift end state.

FIG. 16 is an explanatory diagram of a state in which the ring dog portion is rotated together.

FIG. 17 is an explanatory diagram of a state in which the ring dog portion starts to come into contact with the sleeve dog portion.

FIG. 18 is an explanatory diagram of a state in which the ring dog portion is rotated by pressing the sleeve dog portion.

FIG. 19 is a configuration diagram of a gear portion of a conventional transmission.

20 is a configuration diagram of a shift operation unit of the transmission shown in FIG.

21 is a configuration diagram of a gear shift operation unit of the transmission of FIG.

22 is an explanatory diagram showing a state where the main shaft of the transmission shown in FIG. 19 inertially rotates and the reverse main gear is not meshed with the reverse idler gear.

23 is an explanatory diagram showing a state where a reverse idler gear meshes with a reverse main gear in the transmission shown in FIG.

24 is an explanatory diagram showing a state where a reverse idler gear meshes with a reverse counter gear in the transmission shown in FIG.

[Explanation of symbols]

 2 transmission 10 main shaft 12 counter shaft 32 reverse main gear 68 reverse counter gear 100 reverse idler shaft 102 reverse idler gear 122 reverse gear shift yoke 128 taper surface 130 sliding surface 132 synchronizer ring 142 reverse idler sleeve 156 reverse gear shift arm 170 cam section

[Procedure amendment]

[Submission date] July 16, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0062

[Correction method] Change

[Correction content]

The operation of the gear squeal preventing mechanism 124 is as follows.
It is shown in Table 1.

[Table 1]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

[Fig. 12]

[Fig. 13]

FIG. 14

FIG. 15

FIG. 16

FIG. 17

FIG. 18

FIG. 20

FIG. 19

FIG. 21

FIG. 22

FIG. 23

FIG. 24

Claims (2)

[Claims] 1. A main shaft, a counter shaft, and a reverse idler shaft are arranged substantially parallel to each other in a transmission case, a reverse main gear is provided on the main shaft, a reverse counter gear is provided on the counter shaft, and the reverse idler is provided. A reverse idler gear is installed on the shaft, and the reverse gear shift arm that is linked to the reverse gear shift yoke during reverse shift operates to slide the reverse idler gear on the reverse idler shaft to mesh with the reverse main gear and the reverse counter gear. In the machine, a gear noise prevention mechanism that stops rotation of the reverse idler gear due to inertial rotation of the main shaft at the beginning of the reverse shift operation and allows rotation of the reverse idler gear at the end of the reverse shift operation is provided on the reverse idler shaft. When A gear noise preventing mechanism for a reverse gear shift, which is provided between the reverse gear shift yokes. 2. A main shaft, a counter shaft, and a reverse idler shaft are arranged substantially parallel to each other in a transmission case, a reverse main gear is provided on the main shaft, a reverse counter gear is provided on the counter shaft, and the reverse idler is provided. A reverse idler gear is installed on the shaft, and the reverse gear shift arm that is linked to the reverse gear shift yoke during reverse shift operates to slide the reverse idler gear on the reverse idler shaft to mesh with the reverse main gear and the reverse counter gear. In the machine, one end side of the reverse gear shift arm is arranged to stop the rotation of the reverse idler gear accompanying the inertial rotation of the main shaft at the initial stage of the reverse shift operation and allow the rotation of the reverse idler gear at the end of the reverse shift operation. To A cam portion is provided on the other end side of the reverse shift arm while supporting the shaft, a taper surface is formed on the outer periphery of the reverse idler gear base portion of the reverse idler gear, and a synchronizer ring is fitted on the taper surface. A reverse idler sleeve provided with a sleeve dog portion that contacts and separates from the ring dog portion of the synchronizer ring is rotatably slidably provided on the outer periphery of the reverse idler gear base portion, and the reverse gear shift arm swings by the operation of the reverse gear shift yoke. A gear noise prevention mechanism for a reverse gear shift, characterized in that a cam noise prevention mechanism is formed by providing a cam pressing surface on the reverse idler sleeve with which the cam portion comes into contact with and separates from the reverse idler sleeve.