JPH07197953A - Automatic hub clutch device for vehicle - Google Patents

Abstract

PURPOSE:To suppress dragging by winding a coil spring around an outer cam, fitting a fastening cylinder on a releasing cylinder in a relatively rotatable manner, bringing a cam edge of an end of the fastening cylinder into a sliding contact with a projection of a key block, abutting a projection piece of the releasing cylinder to the projection, and engaging a bent piece of the coil spring with a cutout of the fastening cylinder and a long hole of the releasing cylinder. CONSTITUTION:A bent piece 45a is abutted against a cutout 43a of a fastening cylinder 43 by the rotation of an outer cam 7 and a coil spring 45. The coil spring 45 is wound around the outer cam 7, to turn the fastening cylinder 43. When a cutout edge of the fastening cylinder 43 is disengaged with a projection 5c of a key block 5 and a cam edge 43c of the fastening cylinder 43 is in sliding contact with the projection 5c, the outer cam 7 is further moved axially and separated from an inner cam 6. While a releasing cylinder 41 is rotated together with the fastening cylinder 43, a projection piece 41c of the releasing cylinder 41 is abutted against the projection 5c. Only the fastening cylinder 43 is pressed by the bent piece 45a and turned. The bent piece 45b of the coil spring 45 is abutted against an and of a long hole, and the coil spring 45 is unwound. Dragging force of the coil spring 45 in respect to the outer cam 7 is thus reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle which can be switched between rear wheel drive and front and rear wheel drive by operating a transfer valve.
Particularly, the present invention relates to an automatic hub clutch device for a vehicle, in which when the front wheel axle is not rotationally driven, the front wheel idles with respect to the front wheel axle, and when the front wheel axle is rotationally driven, the rotation of the axle is automatically transmitted to the front wheel. It is a thing.

[0002]

2. Description of the Related Art For example, in a conventional automatic hub clutch device disclosed in Japanese Patent Application No. 4-81432, a retaining ring having a cutout or notch is fitted onto an outer cam and elastically attached to the outer cam. It is frictionally engaged and the end cam edge of the captive ring engages a projection projecting radially outward from the key block. When the engagement between the inner cam and the outer cam is released when the hub clutch is connected, the end cam edge comes into sliding contact with the protrusion as the catch ring rotates, and then the catch ring moves axially so that the catch ring moves. Completely separate from the inner cam.

However, even when the hub clutch is connected, the catch ring exerts a frictional engagement force on the outer cam, and the outer cam slides and rotates with respect to the catch ring, so that the catch ring and the outer cam fit especially during high-speed running of the vehicle. If frictional heat is generated at the joint and the enclosed grease is deteriorated, there is a problem that the fitting portion between the catch ring and the outer cam is prematurely worn.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is, when the clutch is connected, by the action of the coil spring wrapping around the outer cam by the tightening cylinder and the slack by the releasing cylinder. It is an object of the present invention to provide an automatic hub clutch device for a vehicle, which suppresses the rotation and axial movement of the coil and the drag of the coil spring, and suppresses the sliding wear of the coil spring and the outer cam.

[0005]

In order to achieve the above object, the structure of the present invention comprises an annular key block having a U-shaped cross section fixed to an axle case, and a rotatable shaft within a predetermined range in the inner space of the key block. An inner cam that is fitted so that it cannot move,
In an automatic hub clutch device for a vehicle, which has an outer cam that is spline-fitted and supported on the axle, and that engages and disengages the inner cam and the outer cam to release and engage the clutch teeth of the axle and the clutch teeth of the wheel hub, the outer periphery of the outer cam A coil spring is wound around, and the tightening cylinder and the release cylinder are fitted so as to be relatively rotatable,
The cam edge formed at the end of the tightening cylinder is slidably contacted with the projection that projects radially outward from the key block, and the projecting piece that projects axially from the release cylinder can collide with the projection, and from both ends of the coil spring. A bent piece projecting radially outward is engaged with a notch of the tightening cylinder and a pair of elongated holes in the circumferential direction of the release cylinder with a gap.

[0006]

[Operation] When the clutch is connected, if the end of the coil spring wound around the outer cam hits the notch of the tightening cylinder, the coil spring will be tightly wound, and the tightening cylinder is rotated / axially moved to disconnect the outer cam from the inner cam. Then, when the projecting piece of the release cylinder collides with the projection of the key block and stops, the coil spring is unwound and the drag on the outer cam is eliminated, and wear due to sliding between the release cylinder and the outer cam is suppressed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The upper half of FIG. 1 is a side sectional view showing a clutch connection state in an automatic hub clutch device for a vehicle according to the present invention, and the lower half thereof is a clutch release state. The axle case 2 suspended from the vehicle body supports the axle 3 by inserting the axle case 3 inside.
The proximal end (left end in the figure) of the is connected to the lateral gear of the differential. The tip of the axle 3 is projected from the axle case 2 and spline-fitted to the sleeve 8. Relative axial movement between the axle 3 and the sleeve 8 is achieved by a retaining ring 10 fitted between the inner peripheral step of the sleeve 8 and the small diameter end of the axle 3, and a pair of inner and outer retaining rings 12,
13 and regulated.

On the other hand, the axle case 2 rotatably supports the wheel hub 22 by a pair of thrust bearings 17. The wheel hub 22 has a known wheel disk superimposed on the flange,
And it is fastened with a plurality of bolts. The wheel hub 22 is butt-joined to the right end with a plurality of bolts 32 together with an extension hub 25 and a cap 28. However, the extension hub 25
May be formed integrally with the wheel hub 22 and the sleeve 8 may be formed integrally with the axle 3.

When the axle 3 is rotationally driven by operating a transmission (not shown) from the driver's cab, the clutch teeth 27a of the hub clutch 27 spline-fitted to the sleeve 8 are changed to the clutch teeth 25a of the extension hub 25. As shown in the upper half of FIG. 1, the rotation of the axle 3 is transmitted to the wheel through the sleeve 8, the hub clutch 27, the extension hub 25, and the wheel hub 22.

A clutch actuating mechanism for automatically meshing the clutch teeth 27a of the hub clutch 27 with the clutch teeth 25a of the extension hub 25 as the axle 3 rotates is provided in the annular space between the extension hub 25 and the sleeve 8. To be done. The hub clutch actuating mechanism includes an annular key block 5 having a U-shaped cross section fixed to the axle case 2, an inner cam 6 fitted in an annular inner space of the key block 5 so as not to be axially movable and rotatable within a predetermined range, and a sleeve. An outer cam 7 spline-fitted to 8,
A coil spring 45 wound on the outer cam 7, a tightening cylinder 43 fitted on the outer cam 7, and a release cylinder 41 fitted on the tightening cylinder 43.
Composed of and.

An annular key block 5 having a U-shaped cross section
Engages a pair of ridges 5a (FIG. 2) formed in the shaft holes with the keyway of the axle 3 and abuts against the detent plate 19a.
The rotation stop plate 19a fixes the nut 4 for tightening the inner ring of the thrust bearing 17 with bolts 19 and suppresses the slack of the nut 4. The left half of the inner cam 6 is rotatably fitted onto the inner space of the key block 5 and is prevented from axial movement by the elastic ring 6b.

The inner cam 6 is a pair of protrusions 6a protruding leftward.
(FIG. 2) is engaged with a pair of arc-shaped slits 5b provided on the end wall of the key block 5. The coil-shaped spring 23 housed in the inner space of the key block 5 has one end locked to the key block 5 and the other end locked to the inner cam 6, respectively.
Is urged to rotate to a neutral rotation position (a position where the protrusion 6a engages with the center of the slit 5b in the circumferential direction). In FIG. 1, the inner cam 6 has a cam tooth 6c (FIG. 3) formed on the right end surface thereof, and engages with a cam tooth 7a formed on the left end surface of the outer cam 7, so that when the both rotate relative to each other, Cam teeth 6c, 7 accompanying axial movement
The engagement of a is released.

The outer cam 7 has a coil spring 45 wound around the outer peripheral surface thereof, a tightening cylinder 43 having an L-shaped cross section, and a release cylinder 41. Tightening tube 43
The release cylinder 41 may be disposed inside out. Tightening tube 4
3. The sliding plate 31 is interposed between the release cylinder 41 and the right end flange 7b of the outer cam 7. The bent pieces 45a and 45b projecting radially outward from both ends of the coil spring 45 are engaged with openings or notches in a tightening cylinder 43 and a releasing cylinder 41 described below with a circumferential gap. When the outer cam 7 rotates, the cam edge 43c formed on the left end surface of the tightening cylinder 43 is brought into sliding contact with the protrusion 5c protruding radially outward from the key block 5, and the tightening cylinder 43
Is axially moved together with the outer cam 7.

A spring 2 is provided between the outer cam 7 and the hub clutch 27.
6 is interposed, and a slide key 9 penetrating the groove 27b of the hub clutch 27 is interposed between the outer cam 7 and the seat plate 29.
The seat plate 29 is brought into contact with the right end surface of the hub clutch 27 by a spring 30 that is interposed between the seat plate 29 and the retaining ring 14 that is locked to the right end of the sleeve 8.

According to the present invention, as shown in FIGS.
The tightening cylinder 43 has a pair of protrusions 5c on the left edge (lower edge in FIG. 3).
Is provided with a notch edge 43b that engages with and an inclined cam edge 43c, and a notch 43a is provided at the right edge (the upper edge in FIG. 3). On the other hand, the release cylinder 41 is formed with an axial protrusion 41c that collides with the protrusion 5c at the left end edge thereof, and is provided with a pair of elongated holes 41a and 41b extending in the circumferential direction. Long hole 41a,
41b intersects the notch 43a at different positions in the axial direction and the circumferential direction, and engages the bent pieces 45a and 45b of the coil spring 45 with a gap in the circumferential direction.

Next, the operation of the automatic hub clutch device for a vehicle according to the present invention will be described. When the rear wheels are driven, the rotation of the engine is blocked by the transfer, and the axle 3 is not driven to rotate. At this time, the hub clutch 27 is pushed to the left in FIG. 1 by the force of the spring 30 to be released, the outer cam 7 is pushed to the left by the force of the spring 26, and the cam teeth 7a are meshed with the cam teeth 6c. There is.

When the rear wheel drive is switched to the front and rear wheel drive by the operation of the transfoil, the rotation of the engine is changed to the axle 3
Transmitted to. The rotation of the axle 3 is transmitted to the inner cam 6, the coil spring 45, the tightening cylinder 43, and the releasing cylinder 41 via the sleeve 8 and the outer cam 7. When the protrusion 6a of the inner cam 6 hits the end of the slit 5b of the key block 5, the outer cam 7 is moved to the position shown in FIGS.
The inner cam 6 and the outer cam 7 are disengaged from each other, and only the outer cam 7 rotates.

As shown in FIG. 4, as the outer cam 7 and the coil spring 45 rotate in the direction of the arrow y, the bent piece 45a has a side edge of the notch 43a of the tightening cylinder 43 (the left edge of FIG. 4). When it hits, the coil spring 45 is dragged by the outer cam 7 and strongly wraps around the outer cam 7, while rotating the tightening cylinder 43 in the arrow y direction.

The notch edge 43b of the tightening cylinder 43 is disengaged from the projection 5c of the key block 5, and the cam edge 43c of the tightening cylinder 43 slides on the projection 5c. Therefore, the outer cam 7 is further axially moved together with the tightening cylinder 43 in the direction of the arrow x, and the cam teeth 7a are completely separated from the cam teeth 6c and are not in contact with each other.

While the release cylinder 41 rotates together with the tightening cylinder 43, the projection 41c of the release cylinder 41 contacts the projection 5c of the key block 5. When only the tightening cylinder 43 is pushed by the bending piece 45a of the coil spring 45 and rotates in the direction of the arrow y, the bending piece 45b of the coil spring 45 hits the end edge (the left end edge in FIG. 4) of the elongated hole 41b, The coil spring 45 is expanded (unrolled), and the drag force (friction torque) of the coil spring 45 on the outer cam 7 is reduced. Therefore,
Sliding wear of the winding portion of the coil spring 45 around the outer cam 7 is suppressed.

On the other hand, the axial movement of the outer cam 7 in the direction of the arrow x first pushes the seat plate 29 to the right in FIG. 1 via the slide key 9 to cancel the force of the spring 30, and then through the spring 26, the hub clutch. Push 27 to the right to engage the clutch teeth 27a with the clutch teeth 25a. Therefore, the rotation of the axle 3 is transmitted to the wheels via the sleeve 8, the clutch teeth 27a of the hub clutch 27, the clutch teeth 25a of the extension hub 25, and the wheel hub 22.

When the front wheel drive is switched to the rear wheel drive by operating the transmission, the rotation of the engine is interrupted by the transfer and the axle 3 is not rotationally driven. When the vehicle is moved backward, the wheel hub 22 and the extension hub 2 are driven by the front wheels.
5, the hub clutch 27, the sleeve 8, the outer cam 7, the coil spring 45, the tightening cylinder 43, and the releasing cylinder 41 are reversely rotated, and the relationship between the protrusion 5c and the protrusion 41c is as shown in FIG. At this time, the inner cam 6 is returned to the neutral rotational position by the force of the spring 23, and the outer cam 7 is meshed with the inner cam 6 by the force of the spring 26. The seat plate 29 and the hub clutch 27 are pushed to the left by the force of the spring 30, so that the clutch teeth 27a move to the clutch teeth 2
It comes off from 5a.

Even when the vehicle is driven by the front and rear wheels to move backward, the hub clutch is automatically connected in the same manner. In the case of reversing, the tightening cylinder 43 is pushed by the bending piece 45b of the coil spring 45 to rotate / axially move, and the protrusion 41 of the release cylinder 41 is moved.
When c hits the protrusion 5c, the bent piece 45a hits the front edge of the elongated hole 41a in the rotational direction, and the coil spring 45 is unwound.

[0024]

As described above, according to the present invention, the coil spring is wound around the outer cam, and the tightening cylinder and the releasing cylinder are fitted on the end of the tightening cylinder so as to be relatively rotatable. The cam edge is slidably contacted with the projection protruding radially outward from the key block so that the projection protruding axially from the release cylinder can collide with the projection, and the bending piece protruding radially outward from both ends of the coil spring. Is engaged with the notch of the tightening cylinder and the pair of elongated holes in the circumferential direction of the releasing cylinder with a gap, so that the end of the coil spring becomes the notch of the tightening cylinder when the clutch is connected. When it hits, the coil spring is strongly wound around the outer cam, the tightening cylinder is rotated and axially moved to separate the outer cam from the inner cam, and then the projection of the release cylinder collides with the projection of the key block and stops. Be done. Therefore, dragging of the coil spring with respect to the outer cam is eliminated, and wear due to sliding between the coil spring and the outer cam is suppressed.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an upper half portion in a clutch connected state in an automatic hub clutch device for a vehicle according to the present invention, and a lower half portion in a clutch released state.

FIG. 2 is a front view of a key block of the hub clutch device.

FIG. 3 is a plan view showing the relationship between the key block, the tightening cylinder, and the release cylinder.

FIG. 4 is an enlarged plan view showing the relationship between the key block, the coil spring, the tightening cylinder, and the releasing cylinder.

[Explanation of symbols]

2: Axle case 3: Axle 5: Key block 5c:
Protrusion 6: Inner cam 7: Outer cam 22: Wheel hub 25
a: Clutch tooth 27: Hub clutch 27a: Clutch tooth 41: Opening cylinder 41a, 41b: Long hole 41 Stoke: c: Projection piece 43: Tightening cylinder 43a: Notch 43c:
Cam edge 45: Coil spring 45a, 45b: Bending piece

Claims (1)

[Claims] 1. An annular key block having a U-shaped cross section fixed to an axle case, an inner cam that is fitted into an inner space of the key block so as to be rotatable within a predetermined range and not axially movable, and spline-fitted and supported on an axle. In an automatic hub clutch device for a vehicle that includes an outer cam, and that disengages and engages the clutch teeth of the axle and the clutch teeth of the wheel hub by engaging and disengaging the inner cam and the outer cam, in addition to winding a coil spring around the outer cam, The tightening cylinder and the release cylinder are fitted to each other so that they can rotate relative to each other, and the cam edge formed at the end of the tightening cylinder is brought into sliding contact with the projection protruding radially outward from the key block, and the axial direction from the release cylinder. The projecting projecting piece can be collided with the projecting piece, and the bending piece projecting radially outward from both ends of the coil spring is formed as one of the notch of the tightening tube and the release tube.
An automatic hub clutch device for a vehicle, which is engaged with a pair of circumferentially elongated holes with a gap.