JPH04159180A - Front wheel suspension device for front-rear wheel drive vehicle - Google Patents

Abstract

PURPOSE:To heighten the freedom of design at the time of determining wheel alignment by changing the fitting position of a hub, fixed to a knuckle, in relation to the knuckle so as to displace the axial position of the hub, thereby moving a front wheel forward/backward to change its trail. CONSTITUTION:This front wheel suspension device 12 of a front-rear wheel drive vehicle is formed of a knuckle 13 for supporting a front wheel 11 rotatably, an upper arm 14 and a lower arm 15 for supporting this knuckle 13 in the freely steered state, a front cushion unit 16, and the like. The knuckle 13 is of the structure of cantilever-supporting the front wheel 11, and provided with a front wheel supporting hub 17 fixed to the lower end part thereof. On the outer peripheral part of the hub 17, an annular outer gear 20 connected to the wheel 11a of the front wheel 11 is rotatably supported, an inner gear 24 meshed with this outer gear 20 is rotatably supported in the hub 17, a first axle 27 is connected coaxially, and a second axle 28 rotatably supported at the lower arm 15 is connected to the first axle 27 through a universal joint 29.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a front wheel suspension system for a front-rear wheel drive vehicle, and particularly relates to the structure of a front wheel axle that transmits engine driving force to the front wheels and supports the front wheels in a freely steerable manner. It is.

[Conventional technology]

A conventional front wheel suspension system for a front and rear wheel drive vehicle is disclosed in Japanese Patent Application Laid-Open No. 143270/1983.

In this, the front wheels of a three-wheeled motor vehicle were supported by a single swing arm that could swing up and down, and a front wheel drive device that transmitted engine power to the front wheels was built into this swing arm. In this front wheel suspension system, a cylindrical body that rotatably supports the axle of the front wheel at its axial center is connected to the front end of the swing arm via two upper and lower pivots so as to be freely steerable, and the axle is connected to a constant velocity joint. It was connected to the front wheel drive unit of the swing arm via the front wheel drive unit. The pivot and constant velocity joint were positioned on the steering axis, and were configured so that when the cylinder rotated around the steering axis by the steering device, the power of the engine was transmitted to the axle. .

[Problem to be solved by the invention]

However, 1. The conventional front wheel suspension system configured as described above has a problem in that there is little freedom in design when determining wheel alignment. This is because with a front wheel suspension system that uses a telescopic front fork, you can change the trail without changing the caster angle by changing the fork offset, but with a front wheel suspension system that uses a swing arm as described above, the caster angle can be changed by changing the fork offset. Because you can't change the trail unless you change it. That is, in order to change the trail with a conventional front wheel suspension system, it is necessary to change the caster angle by changing the positions of the two upper and lower pivots that connect the cylinder and the swing arm.

(Means for Solving the Problems) A front wheel suspension system for a front and rear wheel drive vehicle according to the present invention includes a vertically swingable swing arm that supports the front wheels in a steerable manner, and a lower arm provided with a front wheel drive transmission device. and an upper arm having a wheel interposed between the swinging end of the lower arm and forming a parallel link with the lower arm, and the knuckle is connected to the upper arm in a steerable manner, and and a knuckle, a knuckle fixing hub that rotatably supports a front wheel and an internal gear coupled to the front wheel, and a gear that meshes with the internal gear and rotates on the knuckle fixing hub eccentrically with respect to the axis of the front wheel. A first axle that is freely provided, and a second axle that is connected to the first axle via a universal joint located on the steering axis, is pivotally supported by a lower arm, and is connected to a front wheel drive transmission. They are connected.

[For production]

The knuckle fixing hub is attached to the knuckle by changing its position and shifting the axis of the hub back and forth, thereby moving the front wheel back and forth and changing the trail.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 8.

Part 1 is a side view of a front and rear wheel drive motorcycle that employs the front wheel suspension system according to the present invention, Figure 2 is a plan view showing the same vehicle body structure, and Figure 3 is a diagram of the lower arm bracket in Figure 1 Line sectional view, Figure 4 is II-I in Figure 1.
5 is an enlarged sectional view of the main parts of the power transmission device, FIG. 6 is an enlarged sectional view of the front wheel drive section of the power transmission device, and FIG. 7 is an enlarged sectional view of the front wheel steering device. The enlarged plan view and FIG. 8 are schematic configuration diagrams of the front wheel suspension system showing trail changes. In these figures, ■ is a front and rear wheel drive type motorcycle, 2 is an engine of this motorcycle 1, and this engine 2 is supported by a pair of left and right main frames 3 that are shaped like a mouth when viewed from the side.

The main frame 3 includes upper and lower horizontal pipes 3a and 3b extending in the longitudinal direction of the vehicle body, a lower arm bracket 3c that connects these horizontal pipes 3a and 3b at the front end, and a lower arm bracket 3c that connects the horizontal pipes 3a and 3b at the rear end. It is composed of a rear arm bracket 3d that is connected to the rear arm bracket 3d. Further, the left and right lower arm brackets 3c are divided into two parts: one is connected to the upper horizontal pipe 3a, and the other is connected to the lower horizontal pipe 3b, and both members are connected by bolts. Note that the rear end of the lower horizontal pipe 3b is bolted to the rear arm bracket 3d.

Furthermore, of the left and right lower arm brackets 3c, the lower arm bracket 3c located on the left side of the vehicle body is bent outward in the vehicle width direction to avoid the lower arm, which will be described later, as shown in FIG. . The left and right main frames 3 are connected to each other by connecting the engine 2 to the left and right lower arm brackets 3C via an engine support bracket 3e, and by horizontally suspending cross members 3f and 3g between the left and right rear arm brackets 3d. ing.

4 is a rear wheel, and 5 is a rear arm that supports this rear wheel 4. This rear arm 5 is swingably connected to a rear arm bracket 3d of the main frame 3 via a pivot shaft 5a. Further, of the two arms of the rear arm 5, the arm 5b located on the left side of the vehicle body has a built-in known shaft drive type rear wheel drive device 6 driven by a power transmission device to be described later. 5c is the rear arm 5
A suction unit is interposed between the fuel tank and the main frame 3, 7 is a fuel tank, and 8 is a seat, which are supported by the main frame 3. In addition, 9 is an exhaust pipe, 10
is a footrest attached to the rear arm bracket 3d of the main frame 3 via a bracket 10a.

11 is a front wheel, and 12 is a swing arm type front wheel suspension device that supports the front wheel 11 through parallel links so as to be freely steerable. This front wheel suspension system 12 includes one knuckle 13 that rotatably supports the front wheel 11, and an upper arm 14 that supports this knuckle 13 so that it can be steered. It consists of a lower arm 15, a front cushion unit 16, etc., and the knuckle 13 is connected to a steering device to be described later and is configured to rotate on a steering axis. This steering axis includes the knuckle 13 and the upper arm 14. 2 with lower arm 15
A straight line connecting the two connection brackets is indicated by the dashed line A in FIGS. 1 and 2.

As shown in FIG. 4, the knuckle 13 has a structure that supports the front wheel 11 in a cantilevered manner, and a hub 17 for supporting the front wheel is fixed to the lower end of the knuckle 13 by two bolts 18, front and rear. A plurality of bolt insertion holes (four holes in this embodiment) are provided for mounting the knuckle 13 so that the mounting position of the hub 17 to the knuckle 13 can be changed. That is, when changing the mounting position of the hub 17, the bolt 18 is inserted into the bolt insertion hole and screwed onto the hub 17.

The hub 17 has a right hub 17a and a left hub 17b.
The wheel lla of the front wheel 11 is attached to the outer periphery of the hub 17.
An annular outer gear 20 coupled to is rotatably supported via a bearing 21. Note that a recess 1 in the axial center of the hub 17 is formed on the inner circumference of the outer gear 20.
An internal gear 20a facing 7C is formed. Further, a brake disc support hub 23 supported on the outer circumference of the hub 17 via a bearing 22 is screwed to the outer gear 20 . That is, the front wheel 11 is connected to the outer gear 2
0. Together with the brake disc support hub 23, it rotates relative to the hub 17.

The center of rotation (wheel center) of this front wheel 11 is indicated by a dashed line B in FIG. Reference numeral 24 denotes an inner gear that meshes with the outer gear 20, and the inner gear 24 is rotatably supported within the hub 17 by bearings 25 and 26.
A first axle 27 is coaxially coupled. Further, the arrangement position of the inner gear 24 is set such that its axis is eccentric with respect to the wheel center B. The axial center (drive center) of the inner gear 24 is shown by the dotted chain line C in FIG. Furthermore, a second axle 28 rotatably supported by the lower arm 15 is connected to the first axle 27 via a universal joint 29 . In addition,
The axial center of the universal joint 29 is positioned on the steering axis wAA.

As shown in FIG. 2, the upper arm 14 is formed in a square shape in plan view, pointing toward the front of the vehicle body, and is rotatably attached to the upper end of the top bolt 13 located on the front side.
Brackets 31 provided at the top of the left and right main frames 3
They are each supported so that they can swing up and down. Note that the connecting shaft between the upper arm 14 and the knuckle 13 is the steering axis A.
is positioned at the top.

The lower arm 15 includes a main arm 15a extending in the longitudinal direction on the left side of the vehicle body, and an auxiliary arm 15b extending across from the base of the main arm 15a to the right side of the vehicle body in front of the engine. It is supported by the lower arm bracket 3C of No. 3 so as to be vertically swingable. A front gear case 32, which constitutes a part of a shaft drive type front wheel drive device to be described later, is attached to the swing end of the main arm 15a. The second axle 28 is pivotally supported by the front gear case 32.

That is, the hub 17. First axle 27. Second axle 28
The knuckle 13 and the lower arm 15 are connected via. With this structure, the knuckle 13 is supported by the lower arm 15 so that it can be steered freely and can swing freely in the front and rear directions, so that the knuckle 13 is
When the front wheel 11 rotates, the front wheel 11 moves to the universal joint 29.
It will rotate around.

The front tongue unit 16 includes a core arm 15
The main frame 3 is interposed between the front gear case 32 and the left bracket 31 of the main frame 3.

33 is a power transmission device for driving the rear wheels 4 and front wheels 11, and this power transmission device 33 includes a rear drive shaft 34 that drives the shaft drive type rear wheel drive device 6;
It is composed of a front drive shaft 36 that drives a shaft drive type rear wheel drive device 35, which will be described later. As shown in FIG. 5, the rear drive shaft 34 is installed on the shaft end side of the engine output shaft 2a with its axis parallel to the longitudinal direction of the vehicle body, and is attached to the transmission case 2b of the engine 2.
The drive shaft housing 2C is rotatably supported via bearings 37 and 38, which is integrally provided with the drive shaft housing 2C. Further, the rear drive shaft 24 is rotatably provided with a manual bevel gear 40 that meshes with a bevel gear 39 coupled to the engine output shaft 2a. A damper 41 consisting of a cam and a compression coil spring is mounted on the shaft. By interposing this damper 41 on the input side of the rear drive shaft 34, shocks during sudden acceleration or engine braking can be absorbed. And this rear drive shaft 3
4, the shaft drive type rear wheel drive device 6 is connected to the rear end of the rear arm 5 via a universal joint 42 positioned on the swing axis of the rear arm 5, and the front portion thereof is provided with spur gears 43. The front drive shaft 36 is connected via 44. This front drive shaft 3
6 is disposed on the outside of the rear drive shaft 34 in the vehicle width direction (on the left side of the vehicle body) and parallel to the rear drive shaft 34. Further, this front drive shaft 36 has a bearing 4 mounted on a cover 2d integrally formed with the drive shaft housing 2C.
It is rotatably supported via 5 and 46. and,
The engine support bracket 1-3e of the lower arm bracket 3c is bolted to this cover 2d.

Further, among the two spur gears connecting the two shafts, the spur gear 43 of the rear drive shaft 34 is connected to the rear drive shaft 34.
The other spur gear 44 is rotatably supported by the front drive shaft 36 . The spur gear 43 and the rear drive shaft 34 are connected via a connecting member 47 that is spline-coupled to the rear drive shaft 34 and engages with a side portion of the spur gear 43 to form a dog clutch. The connecting member 47 is configured to move forward and backward on the rear drive shaft 34 by operating a switching lever (not shown), thereby connecting and disengaging the dog clutch. That is, when the dog clutch is released, the rotation of the rear drive shaft 34 is the same as that of the front drive shaft 3.
6 will no longer be transmitted.

As shown in FIG. 6, the shaft drive type front wheel drive device 35 is connected to a propeller shaft 51 built in the main arm 15a of the lower arm 15 via a spline 52 to the front end of the propeller shaft 51. The front gear case 32 has a bevel gear 54 rotatably supported via a bearing 53, and a ring gear 55 that meshes with the bevel gear 54. The front gear case output shaft 58 is rotatably supported through the front gear case output shaft 58 and the like. The propeller shaft 51 is connected to the front drive shaft 36 via a universal joint 59 positioned on the swing axis of the lower arm 15. In addition, the front gear case output shaft 58
Inside, there is a second axle 28 that rotates together with the first axle 27.
are connected via a one-way clutch 60. This one-way clutch 60 is used to transmit driving force in only one direction from the front gear case output shaft 58 to the second axle 28. In the shaft drive type front wheel drive device configured in this way, the power of the engine 2 is transmitted from the rear drive shaft 34 through the front drive shaft 36 during running. When the propeller shaft 51 rotates together with the front drive shaft 36, this rotation is caused by the splines 52. It is transmitted to the front gear case output shaft 58 via the bevel gear 54 and ring gear 55.

During normal driving when the rear wheels 4 and front wheels 11 rotate at a constant speed, the driving force of the engine 2 is cut off by the one-way clutch 60 and is not transmitted to the second axle 28, driving only the rear wheels. However, the rear wheel 4 was spinning and the front wheel 11
When the vehicle rotates at a higher speed, the one-way clutch 60 is engaged and the driving force of the engine 2 is transmitted from the front gear case output shaft 58 to the second axle 28.

61 is a steering device for steering the front wheels 11. In this steering device 61, a handle shaft 62a of a handle 62 is rotatably supported by the head vibro 3, and is connected to the knuckle 13 via a pair of left and right push-pull wires 64. The head vibro 3 is supported by a handle support vibro 5 fixed to the horizontal pipes 3a of the left and right main frames 3, and a handle support pipe 66 fixed to the bracket 31 of the main frame 3, and is mounted at the center in the vehicle width direction. It is positioned. The bush pull wire 64 is made up of an inner wire 64a and an outer wire 64b, and the handle side end of the inner wire 643 is pivotally supported by an arm 67 provided at the lower end of the handle shaft 52a so as to protrude left and right. ing. Also,
The knuckle side end of the inner wire 64a is connected to the knuckle 1
It is connected to the upper arm bracket 13a of No. 3 via a pillow ball. Further, the handle side end of the outer wire 64b is supported by the handle support vibro 5, and the knuckle side end is supported by the bar arm 14. Both ends of the left and right push-pull wires 64 are
It is connected to each member from the rear so as to be orthogonal to the axis of the handle shaft (indicated by dotted chain gD in FIG. 1) and the steering axis A, respectively. In addition, the left and right push pull wires 6
The wire connected to the left side of the arm 67 is connected to the right side of the amber arm bracket 13a, and the wire connected to the right side of the arm 67 is connected to the left side of the upper arm bracket 13a. connected. In the steering device 61 configured in this way, when the steering wheel shaft 62a rotates due to a steering operation,
One of the left and right push-pull wires 64 is pulled by the arm 67, and the other is pushed. This Pu・7
The movement of the pull wire 64 is transmitted to the knuckle 13, so that the knuckle 13 is steered in the same direction as the steering wheel 62. Further, when the front wheel suspension system 12 swings and the knuckle 13 moves up and down, the left and right bush pull wires 64 bend while maintaining the state of connection with the knuckle 13. That is, in this steering device 61, the deflection of the push-pull wire 64 can absorb the misalignment between the steering axis iA and the steering wheel axis, which is caused by the movement of the knuckle 13 up and down.

Reference numeral 68 denotes a brake disc for the front wheel brake, and this brake disc 68 is attached to the brake disc support hub 23 of the hub 17 and positioned at the center of the front wheel 11 in the vehicle width direction. 69 is a brake caliper, and this brake caliper 69 is attached to the knuckle 13.

In the front and rear wheel drive type motorcycle 1 configured as described above, when the rear wheel 4 slips due to entering a muddy place while driving, the one-way clutch 60 provided in the shaft drive type front wheel drive device 35 closes the front gear case output shaft. 58 and the second axle 28 are connected, and the driving force of the engine 2 is also transmitted to the front wheels 11. That is, in this case, the driving force of the engine 2 is transmitted from the rear drive shaft 34 to the rear wheels 4 via the shaft drive type rear wheel drive device 6, and from the rear drive shaft 34 to the shaft drive type front wheel drive device 35. The signal is transmitted to the front wheels 11 via. At this time, even if the front wheel 11 is moved up and down or steered, the propeller shaft 51 bends around the universal joint 59, and the first axle 27 bends around the universal joint 29, and the second axle 28 bends around the universal joint 29. On the other hand, since the vehicle is bent, the driving force of the engine 2 is transmitted to the front wheels 11 without interruption.

Furthermore, the trail can be changed by rotating the front wheel supporting hub 17 in the circumferential direction about the wheel center B and changing the attachment position to the knuckle 13. For example, if the position of the hub 17 is changed from the position shown by the solid line in FIG.
will shift toward the front with respect to the knuckle 13. For this reason, the distance (trail) from the intersection of the steering axis A and the road surface to the grounding point of the front wheels 11 changes from 1 to 1 and becomes shorter. 17, the position of the bolt 18 must be changed to fix the hub 17 to the knuckle 13.In other words, the bolt 18 is not inserted through the four bolt insertion holes. To attach the hub 17 to the front insertion hole, replace the bolt 18 and fix the hub 17 to the knuckle 13.

In the present embodiment, the knuckle 13 is mounted using a round hole with a plurality of bolt insertion holes, but the insertion holes may be long in the front-rear direction.

Therefore, by changing the attachment position of the hub 17 to the knuckle 13 and shifting the axial center position of the hub 17 back and forth, the front wheel 11 moves back and forth and the trail changes.

Further, as shown in this embodiment, if the axial center position of the hub 17 is shifted forward with respect to the axial center position of the first axle 27° and the second axle 28, the front wheel 11 will shift forward with respect to the lower arm 15. From this relationship, the rotation angle until the rear part of the front wheel comes into contact with the lower arm 15 during steering can be increased, and the steering angle can be increased.

Furthermore, when the push-pull wire 64 is employed in the steering device 61 as shown in this embodiment, the play of the handle 62 is reduced because the handle 62 and the knuckle 13 are directly connected by the wire.

Furthermore, if there are two push-pull wires 64 on the left and right, steering in either the left or right direction can always be performed by a pulling action, so that responsive steering can be achieved. In particular, if two wires are used, even if one wire breaks, the steering state can be maintained with the other compression wire.

In addition, if the hub 17 attached to the knuckle 13 has the structure shown in this embodiment, the left and right hubs 17a, 17b,
The brake disc support hub 23°, the outer gear 20, the inner gear 24, etc. can be assembled as one unit. Therefore, the trail can be changed without disassembling the hub 17.

〔Effect of the invention〕

As explained above, the front wheel suspension system for a front and rear wheel drive vehicle according to the present invention includes a swing arm that can freely swing up and down that supports the front wheels in a steerable manner, a lower arm provided with a front wheel drive transmission device, and a lower arm that is provided with a front wheel drive transmission device. and an upper arm having a knuckle interposed between the swinging end of the front wheel and the upper arm forming a parallel link together with the lower arm. and a knuckle fixed hub that rotatably supports an internal gear coupled to the front wheel, and a gear that meshes with the internal gear, and a hub that is rotatably provided on the knuckle fixed hub eccentrically with respect to the axis of the front wheel. 1
Position on the axle and steering axis! The knuckle fixing hub is connected to the first axle via a universal joint, and the second axle is pivotally supported by the lower arm and connected to the front wheel drive transmission. By shifting the axial center position of this hub back and forth, the front wheel moves back and forth and the trail changes. Therefore, the degree of freedom in design is increased in determining wheel alignment. Further, since a reduction gear with a large reduction ratio consisting of an internal gear and a first axle is provided in the hub of the front wheel, the reduction ratio of the front wheel drive transmission device disposed on the side of the front wheel can be reduced. Therefore, it is possible to reduce the diameter of a gear reducer or the like located on the side of the front wheel, and when this front wheel suspension system is applied to a motorcycle, a large bank angle can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side view of a front and rear wheel drive type motorcycle that employs a front wheel suspension system according to the present invention, FIG. 2 is a plan view showing the vehicle body structure, and FIG. 111 line sectional view, Figure 4 is IV in Figure 1
-IV line sectional view, FIG. 5 is an enlarged sectional view of the main parts of the power transmission device, FIG. 6 is an enlarged sectional view of the front wheel drive section of the power transmission device, and FIG. 7 is a front wheel steering device. FIG. 8 is a schematic diagram of the front wheel suspension system showing trail changes. 11...Front wheel, 12...Front wheel suspension system, 13...
...knuckle, 14...upper arm, 15.
,,. Lower arm, 17...Hub, 20...Outer gear, 24...Inner gear, 27...1st axle, 28...2nd axle, 29...Universal gear Into, 35...Shaft drive type front wheel drive device.

Claims (1)

[Claims] A swing arm that can swing up and down to support the front wheels in a steerable manner, a lower arm equipped with a front wheel drive transmission,
A knuckle is interposed between the swinging end of the lower arm and an upper arm forming a parallel link with the lower arm, and the knuckle is steerably connected to the upper arm. , a knuckle fixing hub rotatably supporting a front wheel and an internal gear coupled to the front wheel, and a gear meshing with the internal gear, the knuckle fixing hub being eccentric with respect to the axis of the front wheel and rotatably provided on the knuckle fixing hub. and a second axle that is connected to the first axle via a universal joint located on the steering axis, is pivotally supported by the lower arm, and is connected to the front wheel drive transmission. Front wheel suspension system for front and rear wheel drive vehicles.