JP2008051142A - Gear decoupling preventing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear decoupling preventing structure for preventing the decoupling of a gear in a sleeve while preventing an increase in suction force working on the sleeve, especially, the decoupling preventing structure for a synchronizing device. <P>SOLUTION: A tapered tooth face 1a is formed at the tooth face of a sleeve spline 1 so that the tooth width of the sleeve spline 1 becomes wider toward a tooth tip side. Tapered tooth faces 3a are formed at tooth faces of the gear piece spline 3 provided at each gear piece 13 illustrated in Fig.2 so that the tooth width of the gear piece spline 3 becomes wider toward the tooth tip side. An inclined surface 1b facing a tooth base side is formed at the tooth tip side of the tapered tooth face 1a and a rounded face 3b facing the tooth base side is formed at the tooth base side of the tapered tooth face 3a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gear drop prevention structure, and more particularly to a gear drop prevention structure for a synchronization device, and more particularly to a gear drop prevention structure for a synchronization device applied to a gear transmission mounted on a vehicle.

  FIG. 2 is a cross-sectional view of a synchronizing device applied to a vehicle gear transmission.

  Referring to FIG. 2, the gear transmission includes a clutch hub 15 assembled on a shaft 16 so as to be able to transmit torque, and a sleeve 11 supported on the clutch hub 15 so as to be movable in the axial direction and capable of transmitting torque. The gears 10 and 10 loosely fitted on the shaft 16, the gear pieces 13 and 14 that rotate integrally with the gears 10 and 10, and the sleeve 11 and the gear pieces 13 and 14, respectively, are interposed between the sleeve 11 and the gear pieces 13 and 14. It has synchro mechanisms 17 and 18 for transmitting, and a shift fork 12 for moving the clutch sleeve 11 in the axial direction. A sleeve spline 11a is formed on the inner periphery of the sleeve 11, and gear splines 13a and 14a are formed on the outer periphery of the gear pieces 13 and 14, respectively.

  The tooth surfaces of the sleeve spline 11a and the gear piece splines 13a and 14a that are engaged with each other are formed in a tapered shape. The sleeve spline 11a and the gear piece splines 13a and 14a can be released after the rotation of the sleeve 11 side and the gear pieces 13 and 14 side is synchronized by the action of the synchro mechanisms 17 and 18 when the sleeve 11 moves in a predetermined direction. To mesh. Thus, torque is transmitted from the shaft 16 to any one of the gears 10 and 10 via any one of the clutch hub 15, the sleeve 11, and the gear pieces 13 and 14.

  FIG. 3 is a partial view showing an engagement state between a sleeve spline and a gear piece spline for explaining a conventional gear drop prevention structure applied to the gear transmission shown in FIG.

Referring to FIG. 3, conventionally, the tooth spurs of the sleeve spline 11a and the gear piece spline 13a are provided with taper angles Q1 and Q2, respectively, so as to prevent gear slippage between the sleeve spline 11a and the gear piece spline 13a.
JP-A-6-307465

  However, when the gear disconnection force is large, the gear disconnection may not be sufficiently prevented by giving the taper angle Q to the tooth surface of the spline as in the prior art. Further, if the taper angle Q is excessively increased, the suction force generated between the sleeve and the gear piece is excessively increased, and the sleeve is excessively moved to move the sleeve and is positioned at a predetermined shift position. An excessive pressure may be generated between the shift fork and the shift fork may be worn.

  An object of the present invention is to provide a gear disengagement prevention structure, in particular, a gear disengagement prevention structure of a synchronizer, in which an increase in suction force acting on the sleeve is prevented while preventing gear disengagement of the sleeve.

  According to the first aspect of the present invention, a sleeve that rotates together with a shaft is moved in the axial direction, and a sleeve spline formed on the inner periphery of the sleeve is rotated with a gear loosely fitted on the shaft. In a synchronizer that synchronously rotates the gear and the shaft by releasably engaging with a gear piece spline formed on the outer periphery, the tooth width of the sleeve spline is widened on the tooth tip side of the sleeve spline. A tapered tooth surface is formed, and a tooth surface of the gear piece spline is formed on the tooth surface of the gear piece spline so that the tooth width of the gear piece spline is widened on the tooth tip side. A slope facing the tooth base side is formed on the tooth base side of the tapered tooth surface of the gear piece spline. A slidable contact chamfered surface is formed to provide a gear disengagement prevention structure, characterized in that.

  According to the present invention, a slope is formed with a tapered tooth surface on the sleeve spline, and a chamfered surface is formed with the tapered tooth surface on the gear piece spline. In some cases, the sleeve is pressed against the gear piece, and the inclined surface and the chamfered surface are brought into sliding contact with each other, so that the gear disengagement preventing force is enhanced as compared with the case where only the tapered tooth surface is provided. In addition, according to the present invention, since the slope and the chamfered surface are newly provided, the gear disengagement prevention force can be enhanced without increasing the angle of the tapered tooth surface, so that when the sleeve spline and the gear piece spline are engaged, The suction force acting on the sleeve can be reduced, and as a result, wear of the shift fork connected to the sleeve can be suppressed.

  A gear drop prevention structure according to the present invention includes a clutch hub assembled on a shaft so as to be able to transmit torque, a sleeve supported on the clutch hub so as to be movable in the axial direction and capable of transmitting torque, and loosely fitted on the shaft. A gear piece that rotates integrally with the gear, a synchro mechanism that is interposed between the sleeve and the gear piece, and transmits torque between the two by frictional force, and a shift fork that moves the clutch sleeve in the axial direction. ing. The present invention is suitably applied to a synchronizing device in which a sleeve spline is formed on the inner periphery of the sleeve and a gear spline is formed on the outer periphery of the gear piece.

  In a preferred form of the gear slip-off preventing structure of the present invention, the taper angle with respect to the axial direction of the tapered tooth surface provided in the sleeve spline and the gear piece spline is 10 degrees or less, respectively, and the inclined shaft provided in the sleeve spline. The angle with respect to the direction is 45 degrees or less, and the angle with respect to the axial direction of the chamfered surface provided in the gear piece spline is 45 degrees or less.

  In a preferred form of the gear drop prevention structure of the present invention, when the sleeve spline and the gear piece spline are engaged, the tapered tooth surfaces of both face each other, and the inclined surface and the chamfered surface face each other.

  In a preferred form of the gear drop prevention structure of the present invention, when there are a pair of gears or gear pieces loosely fitted to the shaft on both sides of the sleeve, the slope of the present invention is formed on both axial sides of the sleeve spline. Is done. In this form, the tooth base side of the sleeve spline is the axial center side of the sleeve.

  An embodiment of the present invention will be described below with reference to the drawings. The gear drop prevention structure of the present embodiment is applied to the synchronization device shown in FIG. 2, and FIG. 2 can be referred to for the basic configuration of the synchronization device. However, the gear drop prevention structure of the present invention is not limited to the synchronization device shown in FIG. 2 and can be applied to other synchronization devices.

  FIG. 1 is a partial view showing an engagement state between a sleeve spline and a gear piece spline for explaining a gear drop prevention structure according to an embodiment of the present invention.

  Referring to FIG. 1, a tapered tooth surface 1a is formed on the tooth surface of the sleeve spline 1 included in the sleeve 11 shown in FIG. 2 so that the tooth width of the sleeve spline 1 becomes wider on the tooth tip side, and the gear piece 13 shown in FIG. Is formed on the tooth surface of the gear piece spline 3 with a tapered tooth surface 3a so that the tooth width of the gear piece spline 3 is wider on the tooth tip side, and the inclined surface faces the tooth root side on the tooth tip side of the taper tooth surface 1a. 1b is formed, and a chamfered surface 3b facing the tooth base side is formed on the tooth base side of the tapered tooth surface 3a.

  When the sleeve 11 and the gear piece 13 shown in FIG. 2 are engaged with each other, the tapered tooth surfaces 1a and 3a face each other, and the angle of each surface with respect to the sleeve axial direction, that is, the tapered surface so that the inclined surface 1b and the chamfered surface 3b face each other. The taper angles Q1 and Q2 of 1a and 3a, the angle θ1 of the inclined surface 1b, and the angle θ2 of the chamfered surface 3b are set.

  The operation of the gear drop prevention structure according to this embodiment will be described. The shift fork 12 shown in FIG. 2 is operated to displace the sleeve 11 in the axial direction from the neutral position, and by the action of the synchro mechanism 17 (18), the rotation of the gear piece 13 (14) and the sleeve 11 is synchronized. (14) and the sleeve 11 are engaged, that is, when the tapered tooth surfaces 1a and 3a are opposed to each other, when there is torque input or fluctuation, the inclined surface 1b and the chamfered surface 3b come into sliding contact with each other, resulting in a large gear loss. Preventive power is generated.

  In this way, a large gear slip prevention force is generated by the sliding contact between the inclined surface 1b and the chamfered surface 3b. Therefore, even if the taper angles Q1 and Q2 of the taper surfaces 1a and 3a are reduced, a predetermined gear slip prevention force can be obtained. . As a result, the amount of suction of the sleeve 11 when the suction force acts on the sleeve 11 is reduced, and wear of the shift fork 12 is also suppressed.

  Note that the angle θ1 of the inclined surface 1b and the angle θ2 of the chamfered surface 3b can be set so as not to inhibit the shift of the sleeve 11 even when the inclined surface 1b and the chamfered surface 3b are in sliding contact when the sleeve 11 is returned to the neutral position. it can.

  The synchronization device of the present invention is preferably applied to a gear transmission for a vehicle or the like.

FIG. 4 is a partial view showing an engagement state between a sleeve spline and a gear piece spline for explaining a gear drop prevention structure according to an embodiment of the present invention. It is sectional drawing of the synchronizer applied to the gear transmission for vehicles. FIG. 3 is a partial view showing an engagement state of a sleeve spline and a gear piece spline for explaining a conventional gear drop prevention structure applied to the gear transmission shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sleeve spline 1a Tapered tooth surface 1b Slope 3 Gear piece spline 3a Taper tooth surface 3b Chamfered surface 10 Gear 11 Sleeve 11a Sleeve spline 12 Shift fork 13, 14 Gear piece 13a, 14a Gear piece spline 15 Clutch hub 16 Shaft 17, 18 Synchro mechanism Q1, Q2 Taper angle of taper surface 1a, 3a

Claims (3)

A sleeve that rotates together with the shaft is moved in the axial direction, and a sleeve spline formed on the inner periphery of the sleeve, a gear piece spline formed on the outer periphery of the gear piece that rotates together with the gear loosely fitted on the shaft; In the synchronizer that synchronously rotates the gear and the shaft by meshing releasably,
A tapered tooth surface is formed on the tooth surface of the sleeve spline so that the tooth width of the sleeve spline is wide on the tooth tip side,
A tapered tooth surface is formed on the tooth surface of the gear piece spline so that the tooth width of the gear piece spline is wide on the tooth tip side,
An inclined surface facing the tooth base side is formed on the tooth tip side of the tapered tooth surface provided in the sleeve spline,
A gear omission prevention structure, characterized in that a chamfered surface is formed on the tooth base side of the tapered tooth surface of the gear piece spline so as to face the tooth base side and be slidable in contact with the inclined surface. The taper angle with respect to the axial direction of the tapered tooth surface provided in the sleeve spline and the gear piece spline is 10 degrees or less,
The angle with respect to the axial direction of the slope provided in the sleeve spline is 45 degrees or less,
The gear drop prevention structure according to claim 1, wherein an angle of the chamfered surface of the gear piece spline with respect to the axial direction is 45 degrees or less.   3. The gear drop prevention structure according to claim 1, wherein, when the sleeve spline and the gear piece spline are engaged, the tapered tooth surfaces of the sleeve spline and the chamfered surface face each other.

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