JPS627013Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for preventing gear noise in a manual transmission, particularly gear noise during reverse shifting.

Since the reverse shift in a manual transmission is basically performed when the vehicle is stopped, it is mostly a sliding mesh mechanism. Furthermore, in recent years, low-viscosity lubricating oils for manual transmissions have come into widespread use in order to improve fuel efficiency and shift operability at low temperatures. As a result, the shaft, which is in a free state when the clutch is disengaged, continues to rotate inertia, causing gear noise during reverse shifting, making the driver feel uncomfortable and, in severe cases, causing damage to the gears. This problem was particularly likely to occur during the summer when the idling speed was set to high when the cooler was used.

Therefore, the purpose of this invention is to provide a gear noise prevention device that can prevent gear noise caused by inertial rotation of the shaft during reverse shifting.
The aim is to eliminate driver discomfort and gear damage caused by gear noise.

In order to achieve the above object, this invention provides a manual transmission equipped with a synchronized mesh mechanism in which the hub sleeve is moved in a direction opposite to that during a forward shift during a reverse shift.
When shifting to reverse, a friction ring provided on the hub sleeve is brought into pressure contact with a cone body fixed to the case, thereby stopping inertial rotation of the shaft provided with the synchromesh mechanism. It is something.

An embodiment of this invention will be described below with reference to the drawings. First, an outline of the manual transmission with five forward speeds and one reverse speed, which is the subject of this example, will be described with reference to the skeleton diagram in Fig. 1. Case 1 of the transmission has an input shaft 2 and an output shaft. 3 are arranged so as to be mutually parallel and rotatable. A first gear 4, a reverse gear 5, and a second gear 6 are respectively fixed to the input shaft 2 from the right side in the figure.
Further, a third gear 7, a face gear 8, and a fifth gear 9 are each rotatably arranged.
Driven gears 10 and 11 that are always in mesh with the first gear 4 and second gear 6, respectively, are rotatably disposed on the output shaft 3, and driven gears 12 to 14 that are always in mesh with the third gear 7 to fifth gear 9, respectively, are fixed. The first driven gear 10 and the second driven gear 11 each rotate integrally with the output shaft 3 through the connection of the hub sleeve 16 of the first synchronized mesh mechanism 15, and the third driven gear 7 and the fourth driven gear 8 rotate together with the second synchronized mesh mechanism 15. The fifth gear 9 rotates integrally with the input shaft 2 by connecting the hub sleeve 18 of the mechanism 17, and the fifth gear 9 rotates integrally with the input shaft 2 by connecting the hub sleeve 20 of the third synchromesh mechanism 19. (not shown) is shifted from the input shaft 2 to the output shaft 3 via a clutch 21. A reverse driven gear 22 is provided on the outer periphery of the hub sleeve 16 of the first synchronized mesh mechanism 15,
A reverse idler gear shaft 23 rotatably installed on the case 1 includes a reverse idler gear 2.
4 is provided so as to be integrally rotatable and movable in the axial direction, and by moving this reverse idler gear 24 to the left in the figure and meshing with the reverse gear 5 and the reverse driven gear 22 at the same time, the input shaft 2 The rotation is transmitted to the output shaft 3 in reverse. The rotation of the output shaft 3 is transmitted to the differential device 26 by the drive gear 25 on the output shaft 3, and then to the left and right drive shafts 27, 28. The figure shows a state in which the rotation of the input shaft 2 is not transmitted to the output shaft 3, that is, a neutral state of the transmission.

Therefore, the third synchronized mesh mechanism 1
A forward shift fork 29 is engaged with the hub sleeve 20 of No. 9 to allow rotation of the sleeve 20 and to allow the sleeve 20 to move in the axial direction, and a shift arm (not shown) is connected to the reverse idler gear 24. The reverse shift fork 30 is connected to allow the gear 24 to rotate and to move the gear 24 in the axial direction.
When the forkshaft 31 is shifted to the right, the hub sleeve 20 is connected to the fifth gear 9 to obtain the fifth forward speed, and when the forkshaft 31 is shifted to the left, the hub sleeve 20 is connected to the fifth gear 9, and when the forkshaft 31 is shifted to the left, the hub sleeve 20 is connected to the fifth gear 9. is meshed with the reverse gear 5 and the reverse driven gear 22 to obtain reverse operation. In addition, the fork shaft 31 selects the inner lever 34 on the lever shaft 33 by moving the shift and select lever shaft 33 in the axial direction with respect to the shift head 32 fixed to the fork shaft 31. By being rotated, it is shafted in the axial direction.

Next, the configuration of the main part of this invention, including the third synchronized mesh mechanism 19, will be described based on FIG. Adjacent to each other, they are integrally press-fitted by means such as serration fitting. The hub sleeve 20 is spline-slidingly fitted to the outer periphery of the clutch hub 35. As is well known, a shifting key 36 is assembled between the clutch hub 35 and the hub sleeve 20 in a state where it is pressed against the hub sleeve 20 by a key spring 37. On the left side of the fifth gear 9, there is a synchronizing cone 3.
8 are integrally press-fitted by means such as serration fitting. This synchronizing cone 3
A synchronizer ring 40 is disposed on the tapered cone surface 39 of No. 8. The synchronizer ring 40 is engaged with the shifting key 36 and rotates together with the hub sleeve 20.

A cylindrical cone body 42 is provided on the inner surface of the left wall 41 of the case 1 on the same axis as the input shaft 2. The cone body 42 has a tapered cone surface 43 symmetrical to the tapered cone surface 39 of the synchronizing cone 38 on its outer periphery. A friction ring 44 is disposed on this tapered cone surface 39. Like the synchronizer ring 40, this friction ring 44 is engaged with the shifting key 36 and rotates together with the hub sleeve 20. The friction ring 44 has the same shape as the synchronizer ring 40, except that no chamfer is formed thereon.

In the above configuration, when the fifth speed forward shift is performed, the hub sleeve 20 is moved to the right by the operation of the shift fork 29 described above. As a result, rotational synchronization is achieved by the shifting key 36, synchronizing ring 40, and synchronizing cone 38, and the hub sleeve 20
is engaged with the synchronizing cone 38, and the shift is completed.

Contrary to the above, when a reverse shift is performed,
Due to the operation of the reverse shift fork 30 described above, the reverse idler gear 24 is shifted to the reverse gear 5.
and the reverse driven gear 22 at the same time, and the shift is completed. Simultaneously with this reverse shift, the hub sleeve 20 is moved to the left by the operation of the shift fork 29 described above. As a result, the shifting key 36, the friction ring 44
Rotation synchronization is performed by the cone body 42. Here, the friction ring 44 is brought into frictional contact with the cone body 42 fixed to the case 1, and a braking action is applied to the input shaft 2 which rotates by inertia when the clutch is disengaged, so that the rotation of the input shaft 2 is reduced or stopped. . Note that the shifting key 36 is configured to press the friction ring 44 against the cone body 42 from the start to the completion of the reverse shift, and when the reverse shift is completed, the shifting key 36 and the hub sleeve 20 are brought into contact with each other.
Since the axial engagement with the wheel is disengaged and the pressing action is eliminated, almost no load is generated during reverse running.

In the above embodiment, the case 1 includes the cone body 4.
Although the cone body 2 is integrally formed, a separate cone body 42 may be attached to the case 1.

In other words, during reverse shifting, the friction ring provided on the hub sleeve is pressed against the cone body fixed to the case, and the inertial rotation of the shaft is reduced or stopped, thereby eliminating gear noise during reverse shifting. This prevents driver discomfort and gear damage.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a skeleton diagram of a manual transmission, and FIG. 2 is a sectional view of a gear noise prevention device. 1... Transmission case, 2... Input shaft, 5... Reverse gear, 9... Fifth gear (forward gear), 14... Fifth driven gear, 1
9... Third synchronized mesh mechanism, 20... Hub sleeve, 22... Reverse driven gear, 2
4... Reverse idler gear, 29... Shift fork, 30... Reverse shift fork, 31
...Forkshaft, 35...Crutchhub,
36... Shifting key, 38... Synchronizing cone, 40... Synchronizing ring, 42... Cone body, 43... Friction ring.

Claims (1)

[Scope of utility model registration request] During forward shifting, the hub sleeve is moved along the splines of the clutch hub on the shaft rotatably mounted in the transmission case, thereby engaging the shifting key, synchronizing ring, and synchronizing cone of the forward gear. After the synchronization action, the shaft and the forward gear rotatably provided on the shaft are integrally connected, while during a reverse shift, the hub sleeve swings in the opposite direction to that during the forward shift. In a manual transmission equipped with a synchronized mesh mechanism of the type described above, a cone body is fixed to the case wall facing in the direction of missed movement of the hub sleeve, and a friction ring is attached to the hub sleeve to prevent the reverse shift. A gear noise prevention device, characterized in that the gear noise prevention device is provided so as to be pressed against the cone body by the shifting key.