JP2905833B2 - Front wheel suspension for motorcycles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to a front wheel of a lower swing arm, which is provided at a front end of a lower swing arm so as to be steerable via a knuckle. The present invention relates to a suspended front wheel suspension device for a motorcycle.

[Conventional technology]

A conventional front wheel suspension of this type is disclosed in JP-A-63-14 / 1988.
There is one disclosed in Japanese Patent No. 9279. In this front wheel suspension device, one knuckle for rotatably supporting the front wheel is vertically extended on the left side of the front wheel, and an upper swing arm is steerable above the knuckle and a lower swing arm is steerable below the knuckle. And it was connected so that it could swing up and down. The connecting portion between the upper and lower swing arms and the knuckle is located on the same plane passing through the axial center of the front wheel. In particular, the lower swing arm is connected to a portion of the knuckle above the front wheel axle, and is disposed relatively above the steering wheel so as to be less likely to interfere with the front wheel rotating during steering and to allow a large steering angle.

[Problems to be solved by the invention]

However, in the conventional front wheel suspension device configured as described above, the front portion of the lower swing arm faces inward from the side of the front wheel, and its swinging end is located just above the hub of the front wheel. Therefore, the front wheel must have a structure that avoids interference with the lower swing arm. That is, the wheels are formed by cast wheels,
The spokes must be largely bypassed from the center of the front wheel to the side. For this reason, there is a problem that the wheel becomes heavy if the rigidity of the wheel is secured. In order to solve the above-mentioned problem by using a lightweight spoke wheel, the swing end side connecting portion of the lower swing arm is prevented from interfering with the front wheel as disclosed in JP-A-54-102739. Or placed above the front wheels,
What is necessary is just to arrange in the axial center part of a front wheel as disclosed by 25436 gazette. However, if the swing end of the lower swing arm is provided above the front wheel, the gap between the head pipe and the front wheel is occupied by the upper and lower swing arms, so that the suspension stroke is shortened. The span becomes narrow and the torsional rigidity becomes small. In addition, if the swing end of the lower swing arm is provided at the axis of the front wheel, the arm portion protrudes greatly to the side of the vehicle body to secure the steering wheel turning angle because the entire lower swing arm is at a low position. I have to do it. This reduces the bank angle and the road clearance.

[Means for solving the problem]

The front wheel suspension device for a motorcycle according to the present invention is configured such that the knuckle is divided into a left knuckle member and a right knuckle member arranged on the side of the front wheel, and these knuckle members are connected by an upper connecting member and a lower connecting member. The upper connecting member is rotatably connected to each other around the steering axis of the front wheel, the upper connecting member is constituted by a pivot located on the same axis as the steering axis, and the lower connecting member is connected to the steering axis. It is constituted by a front wheel axle that can be bent at the corresponding position and both ends are supported at the lower part of both knuckle members, and the front ends of the upper and lower swing arms are connected to one of these knuckle members and the other is connected to the other. A steering device is coupled to the hub, and a front wheel hub is rotatably supported.

[Action]

The knuckle member to which the upper and lower swing arms are connected shares the reaction force of the suspension, and the other knuckle member shares the steering force.

〔Example〕

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

FIG. 1 is a side view of a front and rear wheel drive type motorcycle employing a front wheel suspension device according to the present invention, FIG. 2 is a front view showing a main part of the knuckle cut away, FIG. 3 is a side view of the same knuckle, FIG. 4 is a top view of the knuckle, FIG. 5 is a front view of a link member used for the front wheel suspension, FIG. 6 is a sectional view of the lower arm taken along line VI-VI in FIG. 1, and FIG. FIG. 8 is a side view of the upper arm, FIG. 9 is a cross-sectional view of the upper arm taken along line IX-IX in FIG. 8, and FIG. 10 is an enlarged view of a swing arm side drive unit of the front wheel drive device. FIG. 11 is a side view showing, in an enlarged scale, a portion of the front arm drive unit in which a swing arm side drive unit is attached to a frame, FIG. 12 is a front view, and FIG.
FIG. 11 is a view taken in the direction of arrow A in FIG. 10. In these figures, 1
1 shows a frame of a front and rear wheel drive type motorcycle. This frame 1 comprises a head pipe 4 which rotatably supports a handle 2 and a link member of a front wheel suspension device to be described later via a steering shaft 3, A main pipe 6 extending rearward and downward from the vehicle body 4 to support the fuel tank 5; and a main pipe 6 disposed below the main pipe 6 and supporting the front side of the engine 7 via an engine bracket 8. And a left and right seat pillar tube 11 connected to the rear of the main pipe 6 and supporting the rear side of the engine 7 via a rear arm bracket 10. A protector 12 is fixed to the engine bracket 8 and the seat pillar tube 11 so as to cover the lower surface of the engine 7.

Reference numeral 20 denotes a front wheel suspension device for suspending the front wheel 21 so as to be steerable. The front wheel suspension device 20 rotatably supports the front wheel 21 via a hub 22 and is connected to the steering shaft 3 via a link member 23. The knuckle 24 includes a lower arm 25, an upper arm 26, and the like that support the knuckle 24 so as to be steerable. As the front wheel 21, a spoke wheel type in which a wire spoke 21a is interposed between the front wheel 21 and the hub 22 is employed.

As shown in FIG. 2, the knuckle 24 is divided into a left knuckle member 27 located on the left side of the vehicle body with respect to the front wheel 21 and a right knuckle member 28 located on the right side of the vehicle body with respect to the front wheel 21. A pair of upper and lower upper axles 29 and a front axle 31 on which a universal joint 30 is interposed are connected.

The upper pivot 29 constitutes an upper connecting member according to the present invention, and the front wheel shaft 31 having the universal joint 30 constitutes a lower connecting member according to the present invention.

The left knuckle member 27 includes an upper bracket 27a that supports the upper pivot 29 via a bearing 32, a pipe portion 27b that extends downward from the upper bracket 27a, and a lower bracket 27c that is connected to a lower end of the pipe portion 27b. The link member 23 is connected to the upper bracket 27a. The position of the upper pivot 29 is set such that its axis is located on the same axis as the axis of the steering shaft 3 (hereinafter referred to as steering axis A) when viewed from the front of the vehicle body. Hereinafter, the turning axis B is inclined according to a predetermined caster angle.

The right knuckle member 28 includes a substantially cylindrical connecting portion 28a to which the upper pivot 29 is connected, a pipe portion 28b extending downward from the connecting portion 28a, and a lower end bracket 28c connected to a lower end of the pipe portion 28b. The cylindrical connecting bracket 28a
And the lower arm 25 is connected to the pipe portion 28b. The connecting portion 28a has its axial direction parallel to the vehicle width direction. Then, a front wheel shaft 31 connecting the left knuckle member 27 and the right knuckle member 28
The hub 2 has a universal joint 30 positioned on the steering axis B, a right end coupled to the lower end bracket 28c of the right knuckle member 28, and a left end coupled to the shaft center of the hub 22.
2, and is rotatably supported by the lower end bracket 27c of the left knuckle member 27. Reference numerals 33 to 35 denote bearings that support the front wheel shaft 31. That is, according to the knuckle 24, the front wheel 21
Is rotated about the steered axis B together with the left knuckle member 27. The connecting portion between the pipe portions 27b, 28b of the left and right knuckle members 27, 28 and the lower end brackets 27c, 28c has a structure in which both ends are overlapped with each other in the vehicle width direction and fastened by connecting bolts 36. By adjusting the length of the overlap with the bolt 37, the knuckle 24
Is configured to be able to adjust the total length.

As shown in FIG. 5, the link member 23 has an upper link 23b connected to the steering shaft 3 via a handle crown 23a, and a link bolt at the lower end of the upper link 23b.
And a lower link 23c connected at its lower part to the left knuckle member 27 of the knuckle 24. The connection between the upper link 23b and the handle crown 23a and the connection between the lower link 23c and the left knuckle member 27 have front wheels 2
A pivot 39 having an axis parallel to the one axis is interposed on the left and right, respectively. The link bolt 38 is connected to the upper link 23b via a bearing 40 and is located on the steering axis A when viewed from the front side of the vehicle body, and the lower link 23c
And a second shaft portion 38b which is connected to the front wheel 21 via a bearing 41 and which is parallel to the axial direction of the front wheel 21. The link member 23 is mounted in a state where the link bolt 38 is bent in the shape of a side view around the link bolt 38 so that the link bolt 38 is disposed behind the steering axis A. That is, in this link member 23, the front wheel
When the 21 is moved up and down, the upper link 23b and the lower link 23c are bent and stretched about the second shaft portion 38b of the link bolt 38. Also, to steer the front wheels 21,
The operation is performed by rotating the handle 2 and rotating the link member 23 and the left knuckle member 27.

The lower arm 25 includes a main arm 25a extending forward and backward on the right side of the vehicle body from the front wheel 21, and an auxiliary arm 25c and the like connected to the main arm 25a via a cross member 25b. The rear end of the auxiliary arm 25c is supported by the engine bracket 8 of the frame 1 so as to be vertically swingable. The swinging end of the main arm 25a is rotatably connected to the right knuckle member 28 of the knuckle 24 via a support shaft 42. The axial direction of the support shaft 42 is parallel to the axial direction of the front wheel 21. Further, as shown in FIG. 6, the front portion of the main arm 25a is connected to the front wheels 21 during steering.
Is slightly extended outward in the vehicle width direction to avoid contact. Reference numeral 43 denotes a front cushion unit. The front cushion unit 43 is disposed at the center in the vehicle width direction and in front of the down tube 9 of the frame 1. The upper end is pivotally supported by the frame 1 via a bracket 44, and the lower end is pivotally supported by the cross member 25b of the lower arm 25.

As shown in FIGS. 7 to 9, the upper arm 26 includes a base side connecting member 26a rotatably supported on the frame 1 side with the vehicle width direction as an axial direction, and the knuckle 2
4, the right end of the vehicle body is extended from the base side connecting member 26a to the front side, and
An upper arm body 26c formed of a square pipe connecting the base side connecting member 26a and the rotating end side connecting member 26b, and extends to the left of the vehicle body from the swinging end side of the upper arm body 26c across the front of the engine and to the left side of the vehicle body. The rear end is composed of an auxiliary arm 26d and the like rotatably supported on the frame 1 side with the vehicle width direction as the axial direction.

The base side connecting member 26a is a cylindrical housing 26 that covers a sprocket for a middle chain of a front wheel drive device described later.
e, and a cap 26f for closing the opening of the cylindrical housing 26e.
Are supported via bearings 45 and 46 on a swing arm side drive unit of the front wheel drive device attached to the drive unit. In addition, the swing arm side drive unit is connected to the auxiliary arm through a bearing 47.
The rear end of 26d is also supported.

The rotating end side connecting member 26b is provided integrally with a cylindrical body 26g facing coaxially within a cylindrical connecting part 28a of the right knuckle member 28, and bearings 48, 49 are provided in the cylindrical body 26g. The connection shaft 50 is supported via the. The rotating end side connecting member 26b is provided between the cylindrical body 26g and the connecting portion 28a.
By interposing a bearing 52 between the connection shaft 50 and the upper right end of the right knuckle member 28, the right knuckle member 28 is rotatably connected to the right knuckle member 28 with the vehicle width direction as a rotation axis.

The upper arm main body 26c has welding blocks 26h welded to both front and rear ends thereof, and the connecting block 26h is fastened to the base-side connecting member 26a and the rotating end-side connecting member 26b by connecting bolts 53. Is connected to the member. The front end of the auxiliary arm 26d is welded to the front connection block 26h of the front and rear connection blocks 26h. As shown in FIG. 9, each of the connecting blocks 26h has a convex portion 26i having a substantially trapezoidal cross section.
6i is fastened in a state of being fitted into the concave grooves of the base side connecting member 26a and the rotating end side connecting member 26b. Note that, of the two connection blocks 26h, the rotation end side connection member 26b
The connection hole for the connecting bolt 53 is an elongated hole. As shown in FIG. 8, the upper arm main body 26c extends in the front-rear direction along a straight line connecting the front and rear rotation axes of the upper arm 26, and the connection bolt 53,
The protrusion 26i is located on this straight line. 54 is an adjustment bolt for adjusting the total length of the upper arm 26, and this adjustment bolt 54 is used for the upper arm body 26c.
Is screwed to the front connection block 26h, and its head is in contact with the rear surface of the rotating end side connection member 26b. In other words, by adjusting the adjusting bolt 54 with the connecting bolt 53 loosened, the rotating end side connecting member 26 is adjusted.
b is shifted with respect to the connection block 26h, and the entire length of the upper arm 26 is expanded and contracted. Reference numeral 55 denotes a chain cover that covers a middle chain of a front wheel drive device, which will be described later. The chain cover 55 is formed by molding a plate material into a substantially U-shaped cross section, and as shown in FIG. 7 and is screwed to the side surface of the connection block 26h so as to surround three sides of the upper arm body 26c.

In the front wheel suspension device 20 configured as described above, when the steering wheel 2 is rotated by the steering operation, the left knuckle member 27 of the knuckle 24 rotates about the steering axis B,
The front wheel 21 rotates together with the left knuckle member 27. When the front wheel 21 moves up and down and the knuckle 24 moves up and down, the lower arm 25 moves around the connection with the engine bracket 8,
The upper arm 26 swings up and down about the connection with the swing arm side drive unit of the front wheel drive device.

Reference numeral 60 denotes a front wheel drive device for driving the front wheel 21. The front wheel drive device 60 is connected to a drive shaft 7a of the engine 7 via a front primary chain 61 and is provided on a swing arm side as a support member for an upper swing arm. Drive unit 62
And a knuckle-side drive unit 65 that is connected to the swing arm-side drive unit 62 via a middle chain 63 that passes above and below the upper arm body 26c, and that drives the front wheel 21 by a front drive chain 64 along the right knuckle member 28.
It is composed of

The front primary chain 61 includes a front wheel drive sprocket 61a which rotates together with the rear wheel drive sprocket 7b.
And a front primary chain sprocket 62a of the swing arm side drive unit 62.

The swing arm side drive unit 62 includes an input side middle shaft 62b in which a bearing 47 for supporting the auxiliary arm 26d of the upper arm 26 and a front primary chain sprocket 62a are coupled to the left end of the vehicle body. A housing 62e that holds the side middle shaft 62b in parallel with the drive shaft 7a of the engine 7 via bearings 62c and 62d and rotatably supports the housing 62e, and is fitted into the right-side large-diameter portion of the input side middle shaft 62b. Input middle shaft 62b
An output side middle shaft 62g coaxially connected to the output side middle shaft 62g via a connecting pin 62f and a dog clutch 66, and a one-way A driven shaft 62k rotatably connected via a clutch 62h and bearings 62i, 62j. The connecting pin 6
Two 2f are inserted and held in the large-diameter portion on the right side of the input-side middle shaft 62b, and are slidably fitted in the outer circumferential groove of the output-side middle shaft 62g. The connecting pin 62f is prevented from coming off by a snap ring fitted to the outer peripheral portion of the input side middle shaft 62b. By using the connecting pin 62f, the output side middle shaft 62g and the input side middle shaft 62b can be rotatable relative to each other in a state where they are prevented from coming off.

The housing 62e of the swing arm side drive unit 62 includes:
As shown in FIGS. 11 and 12, the frame 1 is attached to the seat pillar tube 11 via a fastening ring 67. The fastening ring 67 is formed in a substantially C-shaped cross section in which a fastening bolt 67a is provided at an end edge of the open portion, and is respectively passed through the left and right seat pillar tubes 11 along the vehicle width direction. Welded. The eleventh
In the figure, reference numeral 68 denotes a chain tensioner for adjusting the tension of the front primary chain 61.
The cylindrical base 68a fixed to the
And a chain guide 68c that moves back and forth with respect to the base 68a by adjusting.

The driven shaft of the swing arm drive unit 62
62k has a large-diameter portion facing the shaft end of the output-side middle shaft 62g and a small-diameter portion integrally provided at one end of the large-diameter portion, and the one-way clutch 62h and the bearing 6 are provided in the large-diameter portion.
2i and 62j are attached. A large-diameter portion of the driven shaft 62k is rotatably supported by a housing 62e via a bearing 62l, and a small-diameter portion includes a first sprocket 63a for a middle chain for driving the middle chain 63.
And bearings 45 and 46 for swingably supporting the upper arm 26 are mounted. The one-way clutch 62h transmits a driving force in only one direction from the output side middle shaft 62g to the driven shaft 62k. That is, this one-way clutch 62
When h is mounted, the driving force is normally not transmitted to the front wheels 21 only by driving the rear wheels, but when the rear wheels idle, the driving force is also transmitted to the front wheels 21.

The dog clutch 66 has an output side middle shaft 62g.
A connecting member 66a that is spline-coupled to and engages with the shaft end of the input-side middle shaft 62b, a spring 66b for urging the connecting member 66a toward the input-side middle shaft 62b, and a connecting member 66a It is formed by a release member 66c or the like that moves to the release side against the resilience. The release member 66c penetrates the housing 62e and is rotatably supported by the housing 62e. The eccentric pin 66d inserted into the outer peripheral groove of the connecting member 66a and a switching lever (not shown) such as a handle portion are provided.
And an operating lever 66f connected via a wire 66e. That is, when the release lever 66c is rotated by operating the switching lever, the position of the eccentric pin 66d changes, and the connecting member 66a moves forward and backward on the output side middle shaft 62g. When the dog clutch 66 is released, the driving force of the engine 7 is no longer transmitted from the input middle shaft 62b.

The knuckle-side drive unit 65 is connected to the connection shaft 50 of the upper arm 26 and is connected to the first sprocket 63a for the middle chain via the middle chain 63. A front drive chain drive sprocket 65b coupled to the connection shaft 50 together with the second sprocket 65a for the middle chain; a front wheel side sprocket 65c connected to the front drive chain drive sprocket 65b via the front drive chain 64; It is composed of The front wheel side sprocket 65c is connected to the right end of the front wheel shaft 31 that connects the left and right knuckle members 27 and 28.

70 is a rear arm that rotatably supports a rear wheel 71, 72 is a rear wheel drive chain, and 73 is the rear arm 70 and the frame 1
And a rear cushion unit interposed between the rear cushion unit and the rear cushion unit.
Reference numeral 74 denotes a brake disc for a front wheel brake, and the brake disc 74 is attached to the hub 22. Reference numeral 75 denotes a brake caliper. The brake caliper 75 is fixed to a lower end bracket 27c of the left knuckle member 27.

In the front and rear wheel drive type motorcycle configured as described above, when the rear wheel 71 idles due to entering a mud or the like during traveling, the output side middle shaft 62g is driven by the one-way clutch 62h incorporated in the swing arm side drive unit 62. And the driven shaft 62k are connected, and the driving force of the engine 7 is also transmitted to the front wheels 21. That is, the driving force of the engine 7 is transmitted from the drive shaft 7a to the rear wheel 71 via the rear wheel drive chain 72, and the front primary chain
It is transmitted to the input side middle shaft 62b, the output side middle shaft 62g and the driven shaft 62k via 61. Then, the driving force of the engine transmitted from the driven shaft 62k to the middle chain 63 is transmitted to the front wheels 21 via the knuckle-side drive unit 65 and the front drive chain 64. At this time, even if the front wheel 21 moves up and down, the driving force of the engine 7 is transmitted to the front wheel 21 without interruption because the middle chain 63 swings together with the upper arm 26. Further, since the right knuckle member 28 provided with the front drive chain 64 does not rotate in the steering operation, the driving force is transmitted regardless of the steering operation.

Accordingly, the reaction force of the suspension is shared by the right knuckle member 28 to which the lower arm 25 and the upper arm 26 are connected, and the steering force is shared by the other left knuckle member 27. For this reason, the connection position between the lower arm 25 and the knuckle 24 can be set to an arbitrary position irrespective of the steering axis B.

Also, as shown in this embodiment, when the one-way clutch 62h is used for the swing arm side drive unit 62 of the front wheel drive device 60, the front wheel drive system and the rear wheel drive system may interfere with each other when the vehicle is moved backward, for example, when handling the vehicle. The resistance increases with each other,
As shown in this embodiment, if the dog clutch 66 is provided and the front wheel drive system and the rear wheel drive system are separated from each other when the vehicle is moving backward, the vehicle body can be easily handled. Moreover, when the dog clutch 66 is held in the released state, the vehicle can travel only by rear wheel drive.

〔The invention's effect〕

As described above, the motorcycle front wheel suspension device according to the present invention has a knuckle divided into a left knuckle member and a right knuckle member arranged on the side of the front wheel, and these knuckle members are connected to each other by an upper connecting member. And the lower connecting member is rotatably connected to each other around the steering axis of the front wheel, the upper connecting member is constituted by a pivot located on the same axis as the steered axis, and the lower connecting member is A front wheel shaft which is bendable at a position corresponding to the steering axis and has both ends supported at the lower portions of both knuckle members, and one of these knuckle members is provided with the front ends of the upper and lower swing arms. The upper and lower swing arms are connected by a knuckle member, so that the front and rear hubs are rotatably supported. The reaction force, will share the steering force in the other of the knuckle member. Therefore, the connection position between the lower swing arm and the knuckle can be set to an arbitrary position irrespective of the steering axis B. For this reason, the lower swing arm can be disposed as much as possible above the side of the front wheel, so that the steering wheel turning angle can be increased, and the width of the lower swing arm can be reduced. In addition, since the position of the lower swing arm can be freely set in the vertical direction, the degree of freedom in design is high, and the distance (arm span) between the lower swing arm and the upper swing arm is widened while securing the steering wheel turning angle. Can be taken. In addition, because the lower swing arm is connected to the knuckle on the side of the front wheel,
The front wheel can be a wire spoke type wheel, and the weight can be reduced. When the cast wheel type is used, the spoke portion can be disposed at the center of the front wheel, so that the rigidity does not decrease.

[Brief description of the drawings]

FIG. 1 is a side view of a front and rear wheel drive type motorcycle employing a front wheel suspension device according to the present invention, FIG. 2 is a front view showing a main part of the knuckle cut away, FIG. 3 is a side view of the same knuckle,
FIG. 4 is a top view of the knuckle, FIG. 5 is a front view of a link member used for the front wheel suspension, FIG. 6 is a sectional view of the lower arm taken along line VI-VI in FIG. 1, and FIG. FIG. 8 is a side view of the upper arm, FIG. 9 is a cross-sectional view of the upper arm taken along line IX-IX in FIG. 8, and FIG. 10 is an enlarged view of a swing arm side drive unit of the front wheel drive device. FIG. 11 is a side view showing, on an enlarged scale, a portion of a front arm drive unit in which a swing arm side drive unit is attached to a frame, FIG. 12 is a front view, and FIG.
It is an arrow A view in a figure. 21 front wheel, 22 hub, 20 front wheel suspension device, 23 link member, 24 knuckle, 25 lower arm, 26 upper arm, 27 left knuckle member, 28 right knuckle member, 29
... upper pivot, 30 ... universal joint, 31 ... front wheel axle.

Claims (1)

(57) [Claims] 1. A front wheel suspension device for a motorcycle, wherein a front wheel of the motorcycle extends forwardly of a vehicle body and is provided to be vertically swingable, and a front wheel of the lower swing arm is steerably suspended via a knuckle. Is divided into a left knuckle member and a right knuckle member arranged on the side of the front wheel, and these knuckle members are mutually rotatable about the steering axis of the front wheel by an upper connecting member and a lower connecting member. The upper connecting member is constituted by a pivot located on the same axis as the steered axis, and the lower connecting member is bendable at a position corresponding to the steered axis and has both ends at both ends. It consists of a front wheel axle supported at the lower part of the knuckle member.
A front wheel suspension device for a motorcycle, wherein a front end of a lower swing arm is connected, a steering device is connected to the other end, and a front wheel hub is rotatably supported.