JPH0240903B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a differential for a vehicle, and more particularly to a locking device in a friction plate type simple differential.

[Prior Art] The present applicant has provided a small and lightweight automatic tricycle with one front wheel and two rear wheels. Such vehicles have two rear wheels, which creates a difference between the inner and outer wheels when turning, etc. To deal with this, it is necessary to install a differential device on the axle that drives the left and right rear wheels, which increases the cost. From the viewpoint of weight reduction, a simple friction plate type differential device is used.
Such a friction plate type simple differential device is used not only for motorcycles but also for vehicles with two rear wheels such as small and lightweight four-wheeled vehicles.

[Problems to be Solved by the Invention] By the way, in a friction plate type simple differential device, when a differential that exceeds a set value occurs, slippage occurs between the drive shaft and the driven shaft, and the driving force of the left and right wheels is reduced. becomes unbalanced.

The present invention has been made in view of the above, and its purpose is to directly connect the main drive shaft and the slave drive shaft in the event of excessive slip while performing smooth differential movement by sliding the friction plates. It is an object of the present invention to provide a locking device for a differential gear for a vehicle that is capable of transmitting an even driving force to the drive wheels of the vehicle and has a simple structure and reliable operation.

[Means for Solving the Problems] In order to solve the above problems, the present invention comprises a main shaft having drive shafts attached to both ends thereof, and a main drive shaft and a slave drive shaft. A cylindrical clutch center is disposed at one end of the drive shaft, a slidable cylindrical clutch outer is disposed around the outer periphery of the clutch center, and a clutch inner is disposed at the other shaft end. Friction plates are arranged on the inner periphery of the clutch outer and the outer periphery of the clutch inner, respectively, and a resilient member is arranged between the clutch center and the friction plates, which can press the friction plates and transmit rotational force. In the vehicle differential device, a plurality of cam rollers are disposed on the inner periphery of the clutch outer in parallel with the resilient member in the axial direction, and a guide cam that guides the cam roller to the cylindrical portion of the clutch center. and a cam mechanism for moving the clutch outer in a direction in which the pressing force acting on the friction plate by the elastic member increases due to relative rotation between the main drive shaft and the slave drive shaft. It is characterized by

[Function] Differential movement is performed smoothly by the sliding of the friction plates, and when the differential movement exceeds a predetermined value, it is locked and driving force is transmitted equally to the left and right wheels.

[Embodiment] Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional plan view showing an example of a rear wheel drive mechanism including a locking device of the present invention, in which a continuously variable speed drive pulley 3 driven by a crankshaft 2 of an engine 1 is connected to a driven pulley via a V-belt 4. 5, its output shaft 6 is connected to a transmission gear train 7 and an intermediate shaft 8, and this is meshed and connected to a gear 10 of an axle 11 having left and right drive wheels 9 fixed to both ends.
The main drive shaft 12 and the slave drive shaft 1 are coaxially provided.
It consists of 3.

The base end portion 12a of the main drive shaft 12 has a small diameter, and a tapered portion 12b whose diameter gradually increases axially outward is formed in front of the base end portion 12a, while an enlarged diameter portion is formed at the opposite base end portion of the slave drive shaft 13. A clutch inner 13a is formed, and an axial recess 13b having the same axis is formed on the end face of the clutch inner 13a. The base end 12a of the main drive shaft 12 is loosely engaged with the recess 13b of the clutch inner 13a provided at the base end of the slave drive shaft 13, and the recess 13b
A bearing 14 is interposed between the base end portion 12a and the shafts 12 and 13, and the shafts 12 and 13 are arranged concentrically and integrated via a differential device A so as to be relatively rotatable.

The differential device A is as shown in Fig. 2, and the tapered surface 12b of the base end 12a of the main drive shaft 12 faces outward in the axial direction of the clutch inner 13a at the base end of the slave drive shaft 13, and the outer circumference thereof is The clutch center 15 is fitted through a female tapered surface 15b provided at the center, and is tightened and fixed in the axial direction with a lock nut 16 provided inside the tapered surface 12b. clutch center 15
is attached to the outer periphery of the disk portion 15a at the base end portion 12 of the slave drive shaft.
It has a drum-shaped cylindrical part 15c extending in the direction a, and a small-diameter cylindrical holding part 15d inside this. The cylindrical portion 15c of the clutch center 15
As shown in FIG. 3, the base continuous with the disk portion 15a has a guide surface 17b that is open axially outward, closed axially inward, has a curved concave portion 17a, and has one edge sloped. For example, three guide cams 17 are provided radially at equal angular intervals.

The base portion 18a of the clutch outer 18 is fitted to the outer periphery of the cylindrical portion 15c of the clutch center 15, and
The clutch outer 18 is rotatable relative to the clutch center 15 and movable in the axial direction. The clutch outer 18 has a two-stage drum shape, the base 18a has a small diameter, and the outer end of the clutch outer 18 is provided with a flange 18b bent in the inner diameter direction. are in contact with each other. At the tip of the base 18a of the clutch outer 18, a large-diameter tip 18c whose diameter expands outward in the radial direction is formed in the shape of a drum, and on the peripheral wall of this large-diameter tip 18c, locking notches 19 that are open toward the front in the axial direction are arranged radially in three radial directions. The notch 19 is wide at the back in the axial direction and narrow at the front. The large-diameter tip 18c of the clutch outer 18 faces the outer periphery of the clutch inner 13a at the base end of the slave drive shaft 13 at a distance, and on the other hand, a spline portion 13c is formed on the outer periphery of the clutch inner 13a, and a plurality of disc-shaped friction sections are formed on the outer periphery of the clutch inner 13a. The inner diameter portion of the clutch plate 20 is engaged so as to be movable in the axial direction and restrained in the circumferential direction. A friction plate 21, which is also a disc-shaped friction plate, is placed between the clutch plates 20, and its outer diameter is locked with a notch 19 in the large diameter end 18c of the clutch outer 18 so as to be movable in the axial direction. The outer diameter part of the outermost friction plate 21 is locked with a clip 22 to prevent it from coming off in the axial direction. clutch plate 2
0 and the friction plate 21 are the large diameter tips 18c of the clutch inner 13a and the clutch outer 18.
It will be interposed in between.

A resilient member 23 made of a coil spring is compressed between the innermost side of the friction plate 21 and the opposing surface of the clutch center disk portion 15a, and the resilient member 23 has a coiled inner and outer diameter portion formed into a cylindrical portion. 1
5c and the holding part 15d, and the elastic member 2
At step 3, the friction plate 21 and the clutch plate 20 are pressed together with a predetermined spring load.

The clutch center 15 and clutch outer 18 described above are shown in an exploded perspective view in FIG.

A pin 24 is installed on the inner periphery of the base 18a of the clutch outer 18 so as to be perpendicular to the axial direction, thereby rotatably supporting the cam roller 25, and fitting the cam roller 25 into the inner periphery of the base 18a of the clutch outer 18. The guide cam 17 is fitted and engaged with the guide cam 17 formed on the cylindrical portion 15c of the clutch center 15.

Next, to explain the operation and effect in detail, the main drive shaft 12 is driven as described above, and its rotation is caused by the clutch center 15, the elastic member 23, the friction plate 21, which is a friction plate, and the clutch plate 20.
It is transmitted to the slave drive shaft 13 via the clutch inner 13a. In other words, the friction plate 21 and the clutch plate 20 are brought into a connected state by the pressing force of the resilient member 23 caused by the coil spring disposed between the clutch center 15 and the friction plate 21. This makes it possible to drive the left and right drive wheels 9, 9.

In this case, the clutch outer 18, which is slidably disposed around the outer periphery of the clutch center 15 and holds the friction plate 21, is provided with a resilient member 23 via the friction plate 21, the clutch plate 20, and the clip 22. Since pressure is applied and the clutch outer 18 is biased toward the left side in FIG.
It is located on the bottom surface of the curved concave portion 17a on the left side in the drawing in the guide cam 17 of 5c.

When turning, the rotation difference between the left and right drive wheels 9, 9 due to the difference between the inner and outer wheels overcomes the frictional force due to the spring load of the resilient member 23, and the clutch plate 20
This is absorbed by the sliding between the friction plates 21, and the differential movement between the shafts 12 and 13 is performed smoothly.

By the way, when the drive wheels 9 on the main drive shaft 12 side spin in mud or sand while driving on rough terrain, etc., and a large differential torque exceeding the elastic force of the elastic member 23 is generated, the clutch center 15 and clutch outer 18
A difference in rotation occurs between the two, and the clutch center 15 rotates upward in FIG.
The cam action of b pushes the cam roller 25 to the right as shown in FIG. 7, and the clutch outer 18 having this cam roller 25 moves to the right with respect to the clutch center 15 as shown in FIG.

As the clutch outer 18 moves to the right in FIG. Since the frictional engagement force between the clutch plates 20 is increased, a locked state of connection between the friction plate 21 and the clutch plate 20 is obtained, that is, driving force transmission from the main drive shaft 12 to the slave drive shaft 13 is obtained.

In particular, in the embodiment, since the resilient member 23 is compressed and the open end 15e of the clutch center 15 directly presses the friction plate 21 as shown in FIG. This ensures that the connection is locked, i.e. the main drive shaft 12 and the slave drive shaft 13
are directly connected, and an equal driving force acts on both shafts 12 and 13.

Therefore, even if the drive wheels 9 on the main drive shaft 12 side spin in mud or sand while driving on rough terrain, the main drive shaft 1
2, the slave drive shaft 13 is directly connected, and the drive wheels 9 on the slave drive shaft 13 side are driven, so the running ability can be improved.

In addition, in the embodiment, since the pressing force acting on the friction plate 21 is divided into the pressing force by the elastic member 23 and the pressing force by the clutch center opening side end 15e, the friction plate type is simplified. The pressing force of the resilient member 23 required for normal operation of the differential device A can be freely set, that is, the degree of freedom of operation can be greatly improved.

[Effects of the Invention] As explained above, according to the present invention, in a friction plate type simple differential device, it is possible to perform differential operation smoothly and lock when the differential is more than a predetermined value, thereby equally applying driving force to the left and right wheels. can be transmitted.

In addition, since the friction plates are engaged by moving the clutch outer in the axial direction, the force required to engage the friction plates is applied at a position radially outward from the elastic member that presses the friction plates. This makes it possible to reduce the force required to lock the friction plate provided on the clutch outer and the friction plate provided on the clutch inner, thereby reducing the rigidity of the clutch outer, cam roller, etc. The weight of the lock device of the device can be reduced.

Furthermore, since the cam mechanism that moves the clutch outer in the axial direction is provided in parallel with the resilient member in the axial direction, it is possible to prevent the locking device of the vehicle differential from increasing in size in the axial direction. This prevents an increase in the width between the attached drive wheels, thereby preventing the vehicle from becoming larger in the width direction.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a drive mechanism implementing the differential device of the present invention, Fig. 2 is a longitudinal cross-sectional side view of the differential device, Fig. 3 is a bottom view of the main parts, and Fig. 4 is a diagram of the clutch outer and clutch center. FIG. 5 is an exploded perspective view, FIG. 5 is a cutaway front view of essential parts in the assembled state, and FIGS. 6 and 7 are views similar to FIGS. 2 and 3 in the locked state. In addition, in the drawing, 9 is a drive wheel, 11 is an axle, 12 is a main drive shaft, 13 is a slave drive shaft, 13a is a clutch inner, 15 is a clutch center, 15c is a cylindrical part,
15e is an open end, 17 is a guide cam, 18 is a clutch outer, 20, 21 are friction plates, 23 is an elastic member, 25 is a cam roller, and A is a differential device.

Claims (1)

[Scope of Claims] 1. A main shaft with drive wheels attached to both ends is composed of a main drive shaft and a slave drive shaft, and a cylindrical shaft is provided at the end of either the main drive shaft or the slave drive shaft. A clutch center is provided, a slidable cylindrical clutch outer is provided on the outer periphery of the clutch center, a clutch inner is provided at the other shaft end, and friction is provided on the inner periphery of the clutch outer and the outer periphery of the clutch inner, respectively. In a vehicle differential device, the differential for a vehicle is provided with a plate and a resilient member between the clutch center and the friction plate that can press the friction plate and transmit rotational force, the inner periphery of the clutch outer. A plurality of cam rollers are disposed in parallel with the resilient member in the axial direction, and a guide cam for guiding the cam roller is formed in the cylindrical portion of the clutch center, and the main drive shaft and the slave drive shaft are connected to each other. A locking device for a differential gear for a vehicle, characterized in that a cam mechanism is provided that moves the clutch outer in a direction in which the pressing force acting on the friction plate by the elastic member increases by relative rotation with the clutch outer. 2. The vehicle differential according to claim 1, wherein the open end of the clutch center presses the friction plate by a predetermined relative rotation between the main drive shaft and the slave drive shaft. Locking device for moving equipment.