JP3407930B2 - Reverse synchronizer for transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverse synchronizer for a transmission. 2. Description of the Related Art Generally, among transmissions of automobiles, those in which a reverse gear train is of a selective sliding type are configured such that a plurality of forward gear units can be switched smoothly via a synchronizing device. However, the reverse gear unit is normally configured to be selectively switched by sliding an idler gear without the intervention of a synchronizing device because the gear unit is normally switched in a stopped state. For this reason, when the clutch is disengaged from the neutral state or the slow forward state and the reverse shift is performed, the input shaft that is rotating inertia and the output shaft that is stopped or is rotating at a slow speed are connected via the reverse gear unit. Directly connected,
Gear noise or gear loss may occur. Therefore, as described in, for example, Japanese Patent Application Laid-Open No. 5-39828, a brake member having a partially conical tapered pressure contact surface which expands rearward near the shaft end of the input shaft is provided concentrically. A connecting member integrally provided with the brake member is connected to the shift fork, and a synchronizer ring arranged concentrically with the brake member during the reverse shift is connected to the shift member via a synchronizing device of the gear device for the fifth speed. A reverse synchronizer that frictionally presses against the taper pressure contact surface to brake the inertial rotation of the input shaft,
There is known a structure in which a synchronous fork of a brake member is supported by a shift fork. Here, the connecting member integrally provided with the brake member is connected to the shift fork because vibration during braking is not directly transmitted to the transmission cover, and vibration and vibration during braking are not transmitted. This is because generation of noise can be prevented. However, in such a case, as shown by a chain line in FIG. 6, the connecting position of the connecting member a (rotation restraining pin) with the shift fork 36 is shifted by the shift rod. Since it is configured to be located on the line L connecting the axis of 35 and the rotation center of the brake member b, the synchronous reaction force T1 of the brake member is received by the shift fork as it is during the reverse shift, and the synchronization of the brake member is performed. By receiving the reaction force, a relatively large torque acts in the rotation direction of the shift fork, and the shift fork is slightly rotated by the torque, and a tapping sound is generated between the shift fork and the reverse clutch hub sleeve. There is a problem. The present invention has been made in view of the above, and an object of the present invention is to provide a reverse synchronizer which reduces or eliminates a synchronous reaction force applied to a shift fork during a reverse shift. SUMMARY OF THE INVENTION The present invention provides an input shaft to which a driving force is input from an engine, an output shaft, a gear mechanism for transmitting the driving force from the input shaft to the output shaft, and the gear mechanism. A shift switching mechanism for switching the driving force transmission path via a synchronizing device, a shift rod for driving the shift switching mechanism, a shift fork connected to the shift rod, and rotatably loosely fitted to the input shaft, A reverse synchronizer for a transmission, comprising: a brake member that receives a frictional force from the synchronizer during a reverse shift to apply a brake to the input shaft; and a connecting member that is provided integrally with the brake member and that is connected to the shift fork. Is assumed. According to the first aspect of the present invention, when the connecting position of the connecting member to the shift fork is set to a reverse shift
From the brake member acting on the shift fork
In order to reduce the initial reaction force, the shaft center of
It is configured to be offset between a rotation center of the key member and a line connecting the axis of the shift rod and the rotation center of the brake member. According to the first aspect of the present invention, the shift fork receives the synchronous reaction force of the brake member during the reverse shift. In this case, the connecting position of the connecting member with the shift fork is changed to the position of the shift rod. Since the offset is offset from the line connecting the axis and the rotation center of the brake member, the synchronous reaction force T2 of the brake member does not act on the shift fork as it is, The component force T3 acts on the shift fork, and as a result, in the conventional case (the connection position of the connection member with the shift fork is not offset from the line connecting the axis of the shift rod and the rotation center of the brake member). ), The synchronous reaction force of the brake member received by the shift fork is greatly reduced, and the shift fork rotates slightly. Disappears (see the solid line in FIG. 6). Embodiments of the present invention will be described below in detail with reference to the drawings. In this embodiment, the present invention is applied to a reverse synchronizer of a manual transmission having five forward speeds. In FIG. 1 showing a schematic configuration, 1 is a manual transmission, 2 is a substantially cylindrical transmission case, and a transmission cover 3 made of a steel plate is attached to its rear end in an oil-tight manner. In the transmission case 2, an input shaft 6 connected to an engine output shaft 5 via a clutch 4 and an output shaft 7 arranged in parallel to the input shaft 6 via a pair of front and rear bearings 8, 9. Five forward gear devices 10 to 14 for the first to fifth speeds are provided rotatably and supported on the input shaft 6 and the output shaft 7 respectively. The input gears 15 to 19 on the input shaft 6 of the gear units 10 to 14 and the output gears 20 to 24 on the output shaft 7 are always meshed with each other.
5, 16, 22 to 24 are integrally formed or spline-fitted to the input shaft 6 or the output shaft 7 so as to rotate integrally, and the other gears 17 to 19, 20, 21 are connected to the input shaft 6 or
Alternatively, it is mounted on the output shaft 7 so as to be relatively rotatable. Note that lubricating oil is filled up to the vicinity of the lower end of the output shaft 7 in the transmission case 2 and the space formed by the transmission case 2 and the transmission cover 3. The gear device 1 for the first speed and the second speed
The gears between the gears 20 and 21 of the gears 0 and 11, the gears 17 and 18 of the gear devices 12 and 13 for the third speed and the fourth speed, and the gears 19 behind the gear 19 of the gear device 14 for the fifth speed 20, 21,
Synchronizing devices 25 to 27 for selectively coupling one of the driving shafts 17 to 19 to the input shaft 6 or the output shaft 7 are provided, and these synchronizing devices 25 to 27 are connected to a shift lever via a shift device (not shown). Operated according to the operation. Since the synchronizers 25 to 27 have the same configuration, the synchronizer 27 for the fifth speed will be described. As shown in FIGS. 1 to 4, the input gear 19 of the fifth speed gear device 14 is relatively rotatably supported near the rear end of the input shaft 6. The clutch hub 30 is spline-fitted concentrically, and a sleeve 31 is spline-fitted to the outer peripheral portion of the clutch hub 30 so as to be movable in the axial direction. Keys 33 urged outward through a pair of front and rear annular springs 32 are mounted between the clutch hub 30 and the sleeve 31 at predetermined intervals in the circumferential direction. A boss portion 19a extending to the bottom is formed. At the front of the boss 19a, a gear spline 19b that can be spline-fitted to the sleeve 31 is formed, and at the rear of the boss 19a, a partially conical tapered pressure contact surface 19c that increases in diameter toward the front is formed. A synchronizer ring 34 that can be spline-fitted to the sleeve 31 is externally fitted to the tapered pressure contact surface 19c. As shown in FIGS. 2 and 4, the shift device operates a synchronizer 27 for the fifth speed, and includes a shift rod 35 supported movably in the front-rear direction below the input shaft 6. A shift fork 36 fixed to the rear end of the shift rod 35 and extending upward from the shift rod 35 and having a pair of arm portions 36a engaged with the annular groove 31a of the sleeve 31. In the synchronizer 27, when the sleeve 31 is operated forward through the shift rod 35 and the shift fork 36 by operating the shift lever, as shown by the two-dot chain line in FIG.
Moves forward via the key 33 to form the tapered pressure contact surface 19c.
And the rotation of the input gear 19 causes the clutch hub 3 to rotate.
0 is gradually synchronized. Next, after the key 33 moves inward, the sleeve 31 is spline-fitted to the synchronizer ring 34, and the rotation of the sleeve 31 and the input gear 19 is almost completely synchronized. The two gear splines 19b are spline-fitted to each other to be integrally connected. A reverse gear device 37 is provided between the first speed gear device 10 and the second speed gear device 11. The gear device 37 has an input shaft as shown in FIG. 6 and an output gear 39 formed on the outer peripheral portion of the sleeve 25a of the synchronizing device 25. The input gear 38 is rotatably and axially mounted on an idle shaft 40 as shown in FIG. When the idle gear 41 is moved rearward through a shift fork (not shown) slidably supported, the idle gear 41 becomes an input gear 38 and an output gear 39.
And the rotational force in the direction opposite to that of the input shaft 6 is transmitted to the output shaft 7. That is, when the shift rod 35 is operated forward by operating the shift lever, the gear is shifted to the fifth speed,
When operated backward, it is shifted to reverse. Next, a reverse synchronizer 42 for preventing gear noise during a reverse shift from a neutral state or a slow forward state will be described. The reverse synchronizer 42 will now be described. As shown in FIGS. 2 to 4, a substantially cylindrical tubular portion 43a is provided on the rear side of the clutch hub 30 and a shift fork is provided from the lower rear end of the tubular portion 43a. And an extension 43b extending to the 36th side.
Is rotatably supported concentrically on the input shaft 6 via a bearing sleeve 44 in the cylindrical portion 43a, and is held immovably in the axial direction between the flange portion 44a of the bearing sleeve 44 and the clutch hub 31. The outer peripheral surface of the cylindrical portion 43a is formed with a tapered pressure contact surface 45 having a partially conical surface that increases in diameter rearward, and the front portion of the cylindrical portion 43a can be frictionally pressed against the tapered pressure contact surface 45 and can be pressed against the sleeve 31. A spline-fittable synchronizer ring 46 (corresponding to a friction welding member) is externally fitted, and a rotation restraining pin 47 (connecting member) in the front-rear direction that penetrates the lower end of the extension 43b through the middle portion of the shift fork 36 Is fastened, and the rotation restraining pin 4
Between the shift fork 36 and the shift fork 36, a spacer member 48 for sound and vibration isolation is interposed. This rotation restraining pin 47
Position (connection position) with the shift fork 36
Is largely offset from a line connecting the axis of the shift rod 35 and the rotation center of the cylinder 43a of the brake member 43 (see FIG. 2). The shift switching mechanism is constituted by the clutch hub 30, the sleeve 31, the spring 32, and the key 33 of the fifth-speed synchronizing device 27. A lubricating oil tray 51 extending from above the input gear 19 to above the rear part of the cylindrical portion 43a is provided on the upper inner wall surface of the transmission cover 3 at the rear downward. The lubricating oil scooped up by the rotation of the input gear 19 and the output gear 24 is collected in the catching portion 51a formed in the portion, and the collected lubricating oil is collected in the lubricating oil tray 5
1 and is dropped toward the rear upper surface of the cylindrical portion 43a, whereby lubrication between the synchronizer ring 46 and the tapered pressure contact surface 45 is performed. Next, the operation of the reverse synchronizer 42 will be described. In a neutral state or a slow forward state, the input shaft 6 is rotated integrally with the engine output shaft 5 via the clutch 4. Therefore, when the clutch 4 is disengaged and reverse shifted from this state, the input shaft 6 Even after cutting, it tries to rotate inertia for a while. At this time, the sleeve 31 moves rearward via the shift rod 35 and the shift fork 36 by the reverse shift operation of the shift lever,
First, the synchronizer ring 46 is moved rearward via the key 33 and frictionally pressed against the tapered pressure contact surface 45 of the brake member 43, and the sleeve 31 which is to be completely rotated integrally with the input shaft 6 via the clutch hub 30. The rotation is gradually braked via the synchronizer ring 46. Then, after the key 33 moves inward and the sleeve 31 is spline-fitted to the synchronizer ring 46, the inertial rotation of the input shaft 6 is almost completely braked.
The idle gear 41 is reversely engaged with the input gear 38 and the output gear 39. At this time, the fastening position (connection position) of the brake member 43 and the shift fork 36 by the rotation restraining pin 47 is largely offset from a line connecting the axis of the shift rod 35 and the rotation center of the cylinder 43a of the brake member 43. As shown by the solid line in FIG. 6, during the reverse shift, the synchronous reaction force T2 of the brake member 43 (corresponding to the conventional synchronous reaction force T1) does not act on the shift fork 36 as it is, but the synchronous reaction force. T2,
The component T3 in the rotation direction of the shift fork 36 acts on the shift fork 36. As a result, in the conventional case (the connection position of the connection member with the shift fork is determined by the shift center of the shift rod and the rotation center of the brake member) ), The synchronous reaction force of the brake member 43 received by the shift fork 36 is greatly reduced, and the shift fork 36 does not rotate finely. No rattling noise is generated between the clutch hub sleeves. Reference Example In the above-described embodiment, the fastening position (connection position) between the brake member 43 and the shift fork 36 by the rotation restraining pin 47 is determined by the shaft center of the shift rod 35 and the cylindrical portion 43 a of the brake member 43. Is largely offset from the line connecting the rotation center of the brake member 43, as shown in FIG.
The lower end of the extension 43d extending from the cylindrical portion 43c of A is extended to the vicinity of the shift rod 35A, and the extension 43c is connected to the shift fork 36A by the rotation constraint pin 47A and the connection position by the rotation constraint pin 47A is shifted to the shift rod 35A.
, The moment of the synchronous reaction force input to the shift fork 36A during the reverse shift can be eliminated. According to the first aspect of the present invention, as described above, the connecting position of the connecting member to the shift fork is offset from a line connecting the axis of the shift rod and the rotation center of the brake member. Therefore, at the time of reverse shift, the synchronous reaction force of the brake member does not act on the shift fork as it is, but the component of the synchronous reaction force in the rotation direction of the shift fork acts on the shift fork. Can be reduced. Therefore, at the time of the reverse shift, the shift fork does not rotate slightly, and no tapping noise is generated between the shift fork and the reverse clutch hub sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a manual transmission. FIG. 2 is a rear view of the manual transmission. FIG. 3 is a sectional view taken along line III-III in FIG. 2; FIG. 4 is a sectional view taken along line IV-IV in FIG. FIG. 5 is a longitudinal sectional view showing a main part of a reference example . FIG. 6 is an explanatory diagram of a synchronous reaction force of a brake member acting on a shift fork. [Description of Signs] 1 Manual transmission 2 Transmission case 3 Transmission cover 4 Clutch 5 Output shaft 6 Input shaft 10-14 Gear device 35,35A Shift rod 36,36A Shift fork 42 Reverse synchronizer 43,43A Brake member 47 , 47A Rotation restraint pin (connecting member)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-39828 (JP, A) JP-A-3-37456 (JP, A) Japanese Utility Model Application 59-185448 (JP, U) Japanese Utility Model Application 59-185448 165022 (JP, U) JP-A-61-212961 (JP, U) JP-B-61-3987 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 61/26-61 / 36 F16H 63/00-63/38 F16H 3/00-3/78

Claims (1)

(1) An input shaft to which a driving force is input from an engine, an output shaft, a gear mechanism for transmitting the driving force from the input shaft to the output shaft, and driving of the gear mechanism. A speed changeover mechanism for switching a force transmission path via a synchronizing device, a shift rod for driving the speed changeover mechanism, a shift fork connected to the shift rod, and a reverse shift rotatably fitted to the input shaft to be rotatable; A reverse synchronizing device for a transmission comprising a brake member that receives a frictional force at the time of the synchronizing device and applies a brake to the input shaft, and a connecting member that is provided integrally with the brake member and that is connected to the shift fork. of the connecting member, the connecting position of the shift fork, Riva
Brake part received by the shift fork during a gear shift
In order to reduce the synchronous reaction force of the material,
A reverse synchronizer for a transmission, wherein the reverse synchronizer is located between the rotation center of the brake member and a line connecting the axis of the shift rod and the rotation center of the brake member.