JPH06288461A - Tooth striking sound preventing structure for transmission - Google Patents

Abstract

PURPOSE:To provide an effective means for preventing or reducing the wear of a friction damper in a transmission provided with the friction damper to prevent the generation of tooth striking sound. CONSTITUTION:At the idle time, a separate journal 21 is strongly energized inward by a spring member 24 so as to be pressed to a stopper 22. At this time, friction torque is applied to an output gear 5 from a friction damper 25 so as to prevent the generation of tooth striking sound from the output gear 5. At the time of high speed or the like, on the other hand, the rotating speed of the output gear 5 becomes high, and the separate journal 21 is displaced in the direction of being separated from the friction damper 25 against the energizing force of the spring member 24 by centrifugal force. At this time, the lip part of the friction damper 25 is separated from the separate journal 21. Wear is not therefore generated to the lip part of the friction damper 25, so that its durability can be heightened in large degree.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing a rattling noise of a manual transmission having a synchronizing device.

[0002]

2. Description of the Related Art Generally, a manual transmission (manual transmission) has a clutch hub that rotates integrally with a transmission output shaft (main shaft) and a transmission output in order to smoothly perform a shifting operation. A synchronizing device is provided for synchronizing the input gear (gear fixed to the counter shaft) loosely fitted to the shaft with the rotation speed of the output gear that meshes with the shaft during gear shifting (see, for example, Japanese Patent Publication No. 58-54290).

However, in a transmission equipped with such a synchronizing device, the output gear is constantly meshed with the input gear to rotate while the engine is operating, so that the output gear is hardly loaded during idling and the engine is not loaded. Under a situation where the torque fluctuation is large, a relative rotational phase fluctuation occurs between the input gear and the output gear, which causes the input gear and the output gear to collide with each other, resulting in a rattling sound from the meshing portion. There's a problem.

Therefore, a friction damper (resistor) for applying a frictional force to the output gear is provided to prevent relative phase fluctuation between the output gear and the input gear due to the frictional force (friction torque). There has been proposed a transmission designed to prevent the generation of hammering noise. Specifically, for example, one end is fixed to the clutch hub and the other end is provided with a friction damper made of fluororubber or the like that abuts on the inner peripheral surface of the output gear, and the relative rotation speed is provided between the clutch hub and the output gear. It has been proposed that friction force (friction torque) is generated between the friction damper and the output gear when a difference occurs. It should be noted that such gear rattling noise is mainly generated from the output gear for the first speed or the second speed during idling.

[0005]

However, in the conventional transmission provided with such a friction damper,
Since the friction damper is always in contact with the output gear, there is a problem in that the lip portion of the friction damper (contact portion with the output gear) is worn. For example, in the case where a friction damper is provided for the output gear for the first speed, when the transmission is at the second speed or at a shift speed higher than this, the rotation speed of the clutch hub is that of the output gear for the first speed. Since the rotational speed is higher than the rotational speed, the relative rotational speed difference between the friction damper and the output gear becomes very large during high-speed traveling, and the lip portion of the friction damper becomes worn severely.

Further, during racing (during idling) while the vehicle is stopped, the rotational speed of the output gear is significantly higher than the rotational speed of the clutch hub, so that the lip portion of the friction damper is greatly worn. For this reason, the conventional friction damper has low durability, wear progresses at an early stage and sufficient friction torque cannot be obtained, and it is impossible to effectively prevent generation of rattling noise from the output gear. There is.

The present invention has been made in order to solve the above-mentioned conventional problems, and provides a transmission in which a friction damper is provided to prevent generation of rattling noise.
An object of the present invention is to provide an effective means capable of preventing or reducing wear of the friction damper.

[0008]

To achieve the above object, a first aspect of the present invention is directed to a rotation speed of a synchronous side member that rotates integrally with a transmission output shaft and a synchronized side loosely fitted to the transmission output shaft. A gear-type transmission gear tooth transmission noise prevention structure provided with a synchronizing device for synchronizing the rotational speed of a member during gear shifting, wherein a frictional force is generated between the synchronizing side member and the synchronized side member. It is characterized in that a friction member for preventing the generation of a rattling sound from the synchronization side member and a friction force reduction means for reducing the friction force with the increase in the rotation speed of the synchronized side member are provided. To provide a structure for preventing gear rattling noise of a transmission.

According to a second aspect of the invention, in the gear rattling noise prevention structure for a transmission according to the first aspect of the invention, the synchronized journal which is formed separately from the synchronized member body and can be frictionally engaged with the friction member. A member is provided, the synchronized journal member is formed in a divided manner so as to be radially outward and displaceable in a direction away from the friction member, and bias the synchronized journal member toward the friction member side. (EN) Provided is a gear rattling noise prevention structure of a transmission, characterized in that a biasing means is provided.

According to a third aspect of the present invention, in the gear rattling noise prevention structure for a transmission according to the first aspect of the present invention, the friction member is fixed to the synchronized side member while being frictionally engaged with the synchronizing side member side. The frictional member is urged in a direction that is radially outward with the increase in the rotation speed of the synchronized side member and is widened in the direction away from the synchronization side member side, and biases the friction member in the direction away from the synchronization side member side. Provided is a gear rattling noise prevention structure for a transmission, characterized in that a spring is provided to reduce a frictional force between the synchronous member side.

[0011]

EXAMPLES Examples of the present invention will be specifically described below. <First Embodiment> As shown in FIG. 8, in a synchronizer 1 of a gear transmission T (manual transmission), a needle bearing 4 is attached to a second speed journal portion 3 of a transmission output shaft 2 (main shaft). The second-speed output gear 5 is loosely fitted via the. In addition, in the output gear 5 for the second speed,
A gear portion 5a, a cone portion 5b, and a spline portion 6 are provided. Further, in the synchronizer 1, the first speed output gear 9 is loosely fitted to the first speed journal portion 7 of the transmission output shaft 2 via the needle bearing 8, and the first speed output gear 9 has a gear. A portion 9a and a spline portion 10 are provided.

A clutch hub 12 is spline-fitted to a clutch hub connecting portion 11 formed on the transmission output shaft 2 between the second speed journal portion 3 and the first speed journal portion 7. A key groove (not shown) is provided in the hub spline portion 13 provided on the outer circumference of the clutch hub 12, and the synchronizer key 14 is fitted in the key groove. Further, the hub sleeve 15 is spline-fitted to the hub spline portion 13.

When the transmission T is in steady operation at the second speed, the torque of the second speed output gear 5 is transmitted from the spline portion 6 via the hub sleeve 15 and the clutch hub 12 to the transmission output shaft 2. To be transmitted to. Further, during steady operation at the first speed, the torque of the first-speed output gear 9 is transmitted from the spline portion 10 to the hub sleeve 1
5 and the clutch hub 12 are transmitted to the transmission output shaft 2.

When the transmission T is shifted from the neutral state to the second speed, a shift fork (not shown)
Depending on the hub sleeve 15 and synchronizer key 14
And are moved toward the second speed output gear 5 side, and the synchronizer key 14 is used to move the synchronizer ring 16
Is moved to the second speed output gear 5 side, the inner peripheral surface of the synchronizer ring 16 contacts the outer peripheral surface of the cone portion 5b,
The synchronizer ring 16 and the cone portion 5b are frictionally engaged with each other. As a result, the hub sleeve 15 (output shaft 2) and the second speed output gear 5 rotate synchronously, and then the hub sleeve 15 further moves to the second speed output gear 5 side and the synchronizer ring 16 The transmission T is fitted to the outer periphery and further fitted to the spline portion 6 of the second speed output gear 5, and the transmission T is shifted to the second speed. Note that when shifting from the neutral state to the first speed, the description is omitted because it is the same as the above-described case of shifting to the second speed except that the synchronizer ring 17 and the spline 10 are used.

By the way, the transmission T is provided with a rattling noise preventing structure in order to prevent a rattling noise from being generated from the second speed output gear 5 and the first speed output gear 9. Hereinafter, the gear rattling noise prevention structure of the second speed output gear 5 will be described with reference to FIGS. 1 to 3. Although description is omitted, it goes without saying that a gear rattling noise prevention structure is similarly provided for the first speed output gear 9.

As shown in FIGS. 1 to 3, a separate journal 21 formed separately from the output gear 5 is provided near the end of the output gear 5 on the clutch hub 12 side. Here, the separate journal 21 is divided into a first piece 21a and a second piece 21b. The first and second pieces 21a and 21b can be slightly displaced outward in the radial direction of the transmission output shaft 2, but the displacement inward in the radial direction is formed integrally with the output gear 5. The first and second pieces 21a and 21b are regulated by the stopper 22 and cannot be displaced inward from the inner peripheral surface L of the output gear 5. Here, the first and second pieces 21a and 21b respectively include the recess 23 formed in the output gear 5 and the first and second pieces 21a and 21b.
A plurality of spring members 24 interposed between the outer peripheral surface of 21b and
Is always urged inward in the radial direction. In FIG. 1, reference numeral 18 is a third speed output gear, and 19 is a lubricating oil passage.

Further, between the output gear 5 and the clutch hub 12, one end is fixed to the clutch hub 12 and the other end is fixed.
(Lip) is a separate journal 21 (first and second pieces 21
Friction damper 25 that abuts the inner peripheral surface of a, 21b)
(Resistor) is provided. Here, the friction damper 25 is made of a friction material such as fluororubber, and when there is a relative rotational speed difference between the output gear 5 and the clutch hub 12, an appropriate friction force ( Friction torque) is added. In addition,
Clutch hub 12, output gear 5, separate journal 2
1, the spring member 24, and the friction damper 25,
Each of the "synchronous side members" described in the claims,
It corresponds to the “synchronized side member”, the “synchronized side journal member”, the “biasing member”, and the “friction member”.

In the structure for preventing the rattling noise, when the engine is idle (600 to 850 rpm), the first and second pieces 21a, 21b are as shown in FIG.
Are strongly urged inward by spring members 24 and are pressed against the stopper 22. At this time, the lip portion of the friction damper 25 is attached to the separate journal 21 (first,
When there is a relative rotational speed difference between the clutch hub 12 and the output gear 5, the friction damper 25 contacts the output gear 5 with an appropriate frictional force (friction force). Torque) is applied and output gear 5
It is possible to effectively prevent the generation of a rattling noise at a meshing portion with an input gear (not shown) meshing with the gear.

On the other hand, when the engine is not idling or at high engine speed (for example, 1000 rpm or more), as shown in the state of FIG. The first and second pieces 21a, 21b are displaced by the centrifugal force outward in the radial direction against the biasing force of the spring member 24, that is, in the direction away from the friction damper 25, and at this time, the lip portion of the friction damper 25 is separated. Separate from the inner peripheral surface of the body journal 21. When the rotation speed of the output gear 5 is relatively low, the lip portion does not separate from the separate journal 21, and the frictional force merely decreases. Therefore, wear does not occur in the lip portion of the friction damper 25, and the durability thereof is significantly improved.

<Second Embodiment> The second embodiment will be described below with reference to FIGS. 4 to 7. The basic part of the transmission in the second embodiment is the same as that of the first embodiment shown in FIG. Since they are common, the same parts as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
Only points different from the embodiment will be described.

As shown in FIGS. 4 and 5, in the second embodiment, one end of the friction damper 31 is fixed to the end face of the output gear 5, and the other end, that is, the tip of the lip portion 32 is the journal portion 3 (transmission output). It is in contact with the peripheral surface of the shaft 2). The friction damper 31 near the tip of the lip portion
A substantially annular split spring 33, which is partially cut away, is attached to the (lip portion 32). Here, the split spring 33 basically presses the lip portion 32 of the friction damper 31 against the peripheral surface of the journal portion 3 by its contracting force. However, when the friction damper 31 (output gear 5) rotates, a centrifugal force acts according to the rotation speed, and the split spring 33 moves radially outward of the transmission output shaft 2, that is, X _{1 to} X _{3 in} FIG. It is designed to spread in the direction. Here, friction damper 31
The split spring 33 and the split spring 33 correspond to the "friction member" and the "spring" described in the claims, respectively. In addition,
For reference, FIG. 7 shows a conventional friction damper mounting structure. As is apparent from FIG. 7, in the conventional case, the friction damper 31 ′ is fixed to the journal 3 while being frictionally engaged with the inner peripheral surface of the output gear 5.

In the structure for preventing the rattling noise of the second embodiment, when idle (600 to 850 rpm), etc.,
As shown in FIG. 6 (a), the output gear 5
Since the rotation speed is low and therefore the centrifugal force acting on the split spring 33 is weak, the split spring 33 presses the lip portion 32 against the journal portion 3 (transmission output shaft 2) by its contracting force. At this time, due to the frictional force (friction torque) generated between the lip portion 32 and the journal portion 3, the output gear 5 and the input gear meshed therewith
It is possible to effectively prevent the generation of a rattling noise at a meshing portion with (not shown).

On the other hand, at the time of non-idle or high engine speed (for example, 1000 rpm or more), FIG.
As the state is shown in (b), the rotation speed of the output gear 5 becomes high, the centrifugal force acting on the split spring 33 overcomes the contracting force, and the split spring 33 is moved outward in the radial direction. Spread, and at this time, the lip portion 32 is the journal portion 3
Away from the surface. When the rotation speed of the output gear 5 is relatively low, the lip portion 32 does not separate from the journal portion 3, and the frictional force only decreases. Therefore,
The lip portion 32 of the friction damper 31 is not worn, and the durability thereof is significantly improved.

[0024]

According to the first aspect of the present invention, the friction force is applied to the synchronized member by the friction member at the time of idling.
Since (friction torque) is applied, generation of rattling noise from the synchronized member is prevented. On the other hand, at the time of high speed or racing when tooth-sync noise is not generated from the synchronized member, the frictional force between the friction member and the synchronized member is reduced by the frictional force reducing means, so that the frictional member wears. Is prevented.

According to the second invention, basically, the same operation and effect as those of the first invention can be obtained. Further, since frictional force (friction torque) is applied from the friction member to the synchronized side journal member at the time of idling or the like, generation of gear rattling sound from the synchronized side member is more effectively prevented. On the other hand, at high speeds, the synchronized journal member is displaced by the centrifugal force in the direction away from the friction member, so the friction force between the friction member and the synchronized journal member is reduced, and wear of the friction member is more effective. To be prevented.

According to the third invention, basically, the same action and effect as the first invention can be obtained. Further, at the time of idling, etc., the friction member is pressed against the synchronization side member side by the spring, so that friction torque is applied to the synchronized side member due to frictional contact between the friction member and the synchronization side member side. It is possible to more effectively prevent the occurrence of the rattling noise. On the other hand, at high speeds, the spring causes the spring to expand in the radial direction, and the friction member is displaced in the direction away from the synchronization side member side due to this, so the friction force between the friction member and the synchronization side member side is increased. Is reduced and wear of the friction member is prevented more effectively.

[Brief description of drawings]

FIG. 1 is a side cross-sectional explanatory view around a second speed output gear of a transmission according to a first embodiment.

FIG. 2 is a front elevational explanatory view around a second speed output gear when the transmission shown in FIG. 1 is idle.

FIG. 3 is a view similar to FIG. 2 at high speed.

FIG. 4 is a side cross-sectional explanatory view around a friction damper of the transmission according to the second embodiment.

5 is an explanatory front elevational view around a friction damper of the transmission shown in FIG.

6A is a view similar to FIG. 4 at the time of idling, and FIG. 6B is a view similar to FIG. 4 at the time of high speed.

FIG. 7 is a view showing a friction damper mounting structure of a conventional transmission.

FIG. 8 is a side cross-sectional explanatory view around the first and second speed clutch hubs of the transmission according to the present invention.

[Explanation of symbols]

 T ... Transmission 1 ... Synchronous device 2 ... Transmission output shaft 5 ... Second speed output gear 12 ... Clutch hub 21 ... Separate journal 24 ... Spring member 25 ... Friction damper 31 ... Friction damper 33 ... Split spring

Claims (3)

[Claims] 1. A gear provided with a synchronizing device for synchronizing the number of rotations of a synchronous side member that rotates integrally with a transmission output shaft and the number of synchronized side members loosely fitted to the transmission output shaft during gear shifting. A structure for preventing gear rattling noise of a transmission, comprising: a friction member that generates a frictional force between a member on the synchronized side and a member on the synchronized side to prevent generation of tooth rattle from the member on the synchronized side; A gear rattle noise prevention structure for a transmission, comprising: frictional force reducing means for reducing the frictional force as the number of rotations of the synchronized member increases. 2. The gear rattle noise prevention structure for a transmission according to claim 1, wherein a synchronized journal member that is formed separately from the synchronized member body and that can be frictionally engaged with the friction member is provided. The
The synchronized journal member is formed in a divided manner so as to be radially outward and displaceable in a direction away from the friction member, and a biasing means for biasing the synchronized journal member toward the friction member is provided. A structure for preventing gear rattling noise of a transmission, which is characterized by being provided. 3. The gear rattling noise prevention structure for a transmission according to claim 1, wherein the friction member is fixed to the synchronized member while being frictionally engaged with the synchronizing member. With the increase in the number of rotations of the synchronized member, the friction member and the synchronizing member are radially outward and spread in the direction away from the synchronizing member to urge the friction member in the direction away from the synchronizing member. A structure for preventing a rattling noise of a transmission, comprising a spring for reducing a frictional force between the side and the side.