JPH0740415Y2 - Vehicle diff lock device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a diff lock device for a vehicle and is used for a front wheel diff, a rear wheel diff, etc. of a tractor or the like.

(Prior Art) For example, in Japanese Utility Model Application No. 60-171454, a clutch cylinder that is slidable only in the axial direction is fitted onto a differential output shaft, and the sliding of the clutch cylinder causes a boss portion of a differential case in a differential mechanism. There has been proposed a diff lock device for a vehicle, which is fixed and released freely.

(Problems to be solved by the invention) However, in the above technique, the differential case is a casting (for example, a castable material such as a malleable and the claw portion is induction hardened and tempered), while the clutch cylinder is made of steel (for example, , SC
Carburized and tempered with carbon steel such as M415).

Therefore, depending on the usage situation due to the hardness difference in the claw part,
The claws may be damaged or broken, which is a problem in terms of durability.

So, between the cast differential case and the clutch tube,
A diff lock device has been devised which prevents damage or breakage of the claw portion by interposing a steel clutch ring. That is, in FIG. 9, reference numeral 101 denotes a steel clutch ring, and a plurality of circumferential engagement claws 105, 106 formed on mutually opposing surfaces on a boss portion 104 of a cast differential case 103 of the differential mechanism 102.
Are engaged with each other. The boss portion 104 of the differential case 103 is axially supported by the differential bearing case 107 via a bearing 108. 109 is a steel clutch cylinder, which is slidably fitted onto the differential output shaft 110 only in the axial direction.
A plurality of clutch portions 111, 112 that can be engaged and disengaged with each other are provided in the circumferential direction on the opposing surfaces of the clutch ring 101 and the clutch ring 101, respectively. A return spring 113 is provided between the opposing surfaces of the clutch cylinder 109 and the clutch ring 101 so as to urge the clutch portions 111 and 112 in directions away from each other. The engaging claws 106 of the differential case 103 and the engaging claws 105 of the clutch ring 101 are always engaged with each other, and the clutch cylinder 109 is slid against the elastic force of the return spring 113. The clutch portion 111 of the clutch cylinder 109 and the clutch portion 112 of the clutch ring 101 are engaged with each other to lock the differential mechanism 102.

Therefore, when locking and releasing the differential mechanism 102, the clutch portion 111 and the clutch ring of the clutch cylinder 109 are
Since the clutch portion 112 of 101 is engaged and disengaged with each other, the strength of the clutch portions 111 and 112 can be sufficiently ensured, and the differential case 1
It is also possible to effectively prevent damage to the 03 side.

However, since the clutch ring 101 side and the differential case 103 side have a structure in which they are engaged and held by the frictional force of the engaging claws 105 and 106 and the elastic force of the return spring 113 on both sides, both clutch parts are released when the differential lock is released. The clutch ring 101 is inadvertently moved to the clutch cylinder 109 side by the frictional force of 111 and 112, the engagement of both engagement claws 105 and 106 is released, and there is a drawback that the lock operation cannot be performed.

Therefore, in view of the above problems, it is an object of the present invention to provide a device that restricts the inadvertent movement of the clutch ring so that the locking operation can be favorably performed.

(Means for Solving the Problem) The technical means is that the boss portion 9 of the differential case 5 from which the differential output shaft 13 is projected is pivotally supported by the differential bearing case 19, and the clutch ring 23 is meshed with the end surface of the boss portion 9. The clutch cylinder 21 that engages with the clutch ring 23 in a disengageable manner is fitted onto the differential output shaft 13 so as to be slidable in the axial direction and not relatively rotatable.
A return spring 29 is provided between the clutch cylinder 21 and the clutch ring 23 for urging the clutch ring 21 and the clutch ring 23 in directions away from each other, and the clutch ring 23 is meshed with the boss portion 9 by the urging force of the return spring 29. In the diff lock device for vehicle, an overhanging flange 27 is provided on the outer periphery of the clutch ring 23,
A restriction step portion 28 is formed on the inner peripheral surface of the differential bearing case 19 so as to contact the end surface of the overhang flange 27 on the clutch cylinder 21 side and restrict the movement of the clutch ring 23 toward the clutch cylinder 21 side. It is in.

Further, the thrust collar 33 may be interposed between the facing surfaces of the overhanging flange 27 and the regulation step portion 28.

(Operation) According to the present invention, the clutch cylinder 21 is used to release the diff lock.
When the clutch ring 23 is disengaged from the clutch cylinder 21 by sliding the lever toward the side of the differential case 5 by the urging force of the return spring 29, the bulging flange 27 abuts against the regulation step portion 28 at this time. The clutch ring 23 restricts the movement of the clutch ring 23 toward the clutch cylinder 21 side.
The frictional force between the clutch ring 23 and the clutch cylinder 21 prevents the clutch ring 23 from moving to the clutch cylinder 21 side, which prevents the clutch ring 23 from coming off the boss portion 9 of the differential case 5.

(Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, 1 is a front axle case of a tractor, which is supported by a center pin 2 on the vehicle body side. A differential mechanism 3 is provided in the case 1.

The diff mechanism 3 includes a cast diff case 5 having a crown gear 4, a diff pinion gear 7 supported by the case 5 via a pinion shaft 6, a diff side gear 8 with which the diff pinion gear 7 meshes. Both boss portions 9 of the differential case 5 are axially supported by bearings 10, and the bevel gear 12 of the differential drive shaft 11 is engaged with the crown gear 4. Therefore, when the diff drive shaft 11 is driven, the diff mechanism 3 acts as a diff to rotate the pair of left and right diff output shafts 13 to drive the front wheels through the reduction mechanism in the reduction case.

Reference numeral 14 is a differential case lid, which is attached to the differential case 5 and the crown gear 4 with knock pins 15, bolts 16 and the like, and is supported by a bearing 10 on the fixed side, that is, the arm portion 18 of the front axle case lid 17.

Reference numeral 19 denotes a differential bearing case, which is fastened to the other arm portion 18 with a bolt 20 and supports a boss portion 9 of the differential case 5 with a bearing 10.

Reference numeral 21 denotes a clutch cylinder, which is made of carbon steel such as SCM415, is carburized and tempered, and is fitted onto one differential output shaft 13 so as to be slidable only in the axial direction, that is, the inner end side thereof, that is, A clutch portion 22 is provided on the side of the differential case 5, and the clutch portion 22 is substantially a plurality of projection claws in the circumferential direction.

Reference numeral 23 denotes a clutch ring, which is made of steel similar to the clutch cylinder 21 and is mounted on the outside of the bearing 10 so as to restrict axial movement of the inner race of the bearing 10. On the surface facing the 21st side, a clutch portion 24 of the clutch cylinder 21 is provided which is engageable and disengageable in the circumferential direction, and is substantially a plurality of circumferential projection claws as in the above. Further, on the end face of the ring 23 on the side of the differential case 5, a plurality of circumferential engagement pawls 25 provided on the end face of the boss portion 9 of the differential case 5 and a plurality of circumferential engagement pawls 26 engaging in the circumferential direction are provided. The engaging claws 25 and 26 are also projecting claws as in the above. And here clutch ring 23 and differential case 5
And are engaged to rotate integrally. Further, the outer peripheral surface of the clutch ring 23 is provided with an overhanging flange 27 projecting in an outwardly projecting manner in the radial direction, and is disposed within a concave restricting step portion 28 formed on the inner peripheral surface of the differential bearing case 19. The end surface of the overhanging flange 27 on the side of the clutch cylinder 21 comes into contact with the facing surface of the regulation step portion 28 so that the clutch cylinder 21 of the clutch ring 23 can be separated.
Movement of the clutch ring 23 is restricted, and the engaging claw 26 of the clutch ring 23 is restricted.
And the engaging claw 25 on the side of the differential case 5 are held in a constantly engaged state.

Reference numeral 29 denotes a return spring, which is interposed between the clutch cylinder 21 and the clutch ring 23 so as to surround the differential output shaft 13 and pushes back the clutch cylinder 21.

Reference numeral 30 denotes a diff lock operation lever, which pushes the clutch cylinder 21 in the direction of the arrow in FIG. 2 against the spring 29, and is rotated about the fulcrum shaft 31 via a link mechanism or the like (not shown). It

FIG. 3 shows a second embodiment, in which a regulating step portion 28 of a circumferential ridge is provided on the inner peripheral surface of the differential bearing case 19, and the projecting amount of the projecting flange 27 is made small to reduce the processing cost. Has been done.

FIG. 4 shows a third embodiment, in which a thrust collar 33 is provided between the opposing faces of the overhanging flange 27 of the clutch ring 23 and the regulating step portion 28.
The wear is prevented by the relative rotation between the facing surfaces of the overhanging flange 27 and the regulation step portion 28 with the interposition of.

FIG. 5 shows the fourth embodiment, and the clutch portion of the clutch cylinder 21.
22 and the clutch portion 23 of the clutch ring 23, or the engaging claws 26 of the clutch ring 23 and the engaging claws 25 of the differential case 5 are formed in a trapezoidal shape to improve the strength.

6 to 8 disclose another structure for restricting the movement of the clutch ring 23. In the drawings, the same reference numerals are used for the same components as those in the above embodiment.

FIG. 6 shows that the clutch ring 23 is fastened to the boss portion 9 of the differential case 5 with the hexagon socket head cap screw 35 so that the clutch cylinder
Movement in 21 directions is restricted.

FIG. 7 shows a structure in which a bolt 35 is fastened to each other through a collar 36 in order to form a clearance between the clutch ring 23 and the boss portion 9 of the differential case 5, and the torque is transmitted only by the side surfaces of the engaging claws 25 and 26. To prevent the generation of shearing force on the bolt 35.

Further, as a structure for restricting the movement of the clutch ring 23 in the direction of the clutch cylinder 21, an outer peripheral surface of the engaging claw 26 of the clutch ring 23 and the bearing 10 are made to have an interference fit structure so as to increase the frictional force or to return. A structure in which the spring 29 has a large spring constant to improve the reaction force of the spring 29 is conceivable. In FIG. 8, the bearing 10 of the boss portion 9 has a double structure and a clutch ring.
The outer peripheral surface of the engaging claw 26 of 23 and the bearing 10 have an interference fit structure and the contact area is increased.

(Effect of the Invention) According to the present invention, the overhanging flange 27 of the clutch ring 23 comes into contact with the regulation step portion 28, so that the clutch ring 23 becomes the clutch tube 21.
Restricting the movement of the clutch ring 23
The clutch ring 23 is prevented from being disengaged from the boss portion 9 of the differential case 5 by the frictional force between the clutch ring 23 and the clutch cylinder 21, so that the meshing state between the clutch ring 23 and the boss portion 9 of the differential case 5 is reliably maintained, and the diff lock is concerned. Good diff lock operation by the device can be secured for a long time.

Further, the thrust collar interposed between the facing surfaces of the overhanging flange and the regulation step portion can prevent wear caused by relative rotation between the facing surfaces and improve durability.

[Brief description of drawings]

FIG. 1 is a plan sectional view of a front wheel differential device showing a first embodiment of the present invention, FIG. 2 is an enlarged sectional view of an essential part thereof, and FIG. 3 is a sectional view of an essential part showing a second embodiment, FIG. Is a cross-sectional view of an essential part showing a third embodiment, FIG. 5 is a plan view of an essential part showing a fourth embodiment, FIGS. 6 to 8 are cross-sectional views of an essential part showing a comparative example, and FIG. 9 is a prior art. FIG. 5 ... Differential case, 9 ... Boss part, 10 ... Bearing, 13 ...
Differential output shaft, 19 ... Differential bearing case, 21 ... Clutch tube, 22 ... Clutch section, 23 ... Clutch ring, 24 ...
Clutch part, 25, 26 ... Engaging claw, 27 ... Overhang flange, 2
8 …… Regulation step, 29 …… Return spring, 33 …… Thrust collar.

Claims (2)

[Scope of utility model registration request] 1. A boss portion (9) of a differential case (5), from which a differential output shaft (13) is projected, is axially supported by a differential bearing case (19), and a clutch ring (23) is provided on an end surface of the boss portion (9). The clutch cylinder (21) meshed with the clutch ring (23) in a disengageable manner is fitted onto the differential output shaft (13) so as to be axially slidable and non-rotatable relative to the clutch ring (23). And a clutch ring (23) are provided with a return spring (29) for urging them in directions away from each other, and the urging force of the return spring (29) causes the clutch ring (23) to move the boss (9). In a vehicle diff lock device configured to be engaged with a clutch ring (23), an overhanging flange (27) is provided on the outer periphery of the clutch ring (23), and the overhanging flange (27) is brought into contact with the end face of the clutch cylinder (21) side. Clutch ring (23) moves to clutch tube (21) side Restricting stepped portion for restricting (28) is a vehicle differential lock, characterized in that formed on the inner peripheral surface of the differential bearing case (19). 2. The diff lock device for a vehicle according to claim 1, wherein a thrust collar (33) is interposed between the facing surfaces of the overhanging flange (27) and the regulation step (28). .