Leaning vehicle and vehicle leaning unit

1. A leaning vehicle, comprising:

a vehicle body;

a base member supported by the vehicle body so as to be turnable around a turning center relative to the vehicle body;

an upper arm whose longitudinally intermediate portion is pivoted to the base member at a height;

a lower arm whose longitudinally intermediate portion is pivoted to the base member at another height below the height to pivot the upper aim to the base member;

a first support member disposed on one of opposite sides of the base member in a vehicle-width direction;

a second support member disposed on the other of the opposite sides of the base member in the vehicle-width direction;

a first wheel pivoted to the first support member;

a second wheel pivoted to the second support member;

a steering operation member operable to turn the base member; and

a restriction member restricting a rotation angle range of at least one of the upper arm and the lower arm by abutting the at least one of the upper arm and the lower arm,

wherein the upper arm, the lower arm, the first support member and the second support member constitute a parallel link mechanism,

wherein the first wheel is movable integrally with the first support member in a turning direction of the base member,

wherein the second wheel is movable integrally with the second support member in the turning direction of the base member, and

wherein according to turning of the base member, all of the upper arm, the lower arm, the first support member, the second support member, the first wheel and the second wheel turn around the turning center of the base member.

2. The leaning vehicle according to claim 1 , wherein the parallel link mechanism includes:

a first junction where the longitudinally intermediate portion of the upper arm is pivotally connected to the base member;

a second junction where one of the longitudinally opposite side portions of the upper arm is pivotally connected to the first support member;

a third junction where the other of the longitudinally opposite side portions of the upper arm is pivotally connected to the second support member,

a fourth junction where the longitudinally intermediate portion of the lower arm is pivotally connected to the base member;

a fifth junction where one of the longitudinally opposite side portions of the lower arni is pivotally connected to the first support member;

a sixth junction where the other of the longitudinally opposite side portions of the lower arm is pivotally connected to the second support member; and

wherein the first junction, the second junction and the third junction are aligned on a straight line in view along pivot axes of the parallel link mechanism, and

wherein the fourth junction, the fifth junction and the sixth junction are aligned on a straight line in view along the pivot axes of the parallel link mechanism.

3. The leaning vehicle according to claim 1 , wherein when the leaning vehicle is viewed in front, at least a part of the parallel link mechanism is disposed between the first wheel and the second wheel.

4. The leaning vehicle according to claim 1 , wherein a pivot axis pivoting the upper arm to the base member and a pivot axis pivoting the lower arm to the base member are each inclined to have opposite axial ends different in height from each other.

5. The leaning vehicle according to claim 4 , wherein the pivot axis pivoting the upper arm to the base member and the pivot axis pivoting the lower arm to the base member are each inclined forwardly downward from a horizontal plane.

6. The leaning vehicle according to claim 1 , wherein both a pivot axis pivoting the upper arm to the base member and a pivot axis pivoting the lower arm to the base member are parallel to a road surface.

7. The leaning vehicle according to claim 3 , further comprising:

a transmission member interposed between the steering operation member and the base member,

wherein the steering operation member, the transmission member, and the base member are integrally turnable relative to the vehicle body.

8. The leaning vehicle according to claim 7 , wherein the transmission member includes a shock absorber for reducing a shock transmitted from a road surface to the vehicle body via the first wheel or the second wheel.

9. The leaning vehicle according to claim 8 , wherein the upper arm includes:

a first left arm portion disposed close to the first support member leftward with respect to the longitudinally intermediate portion of the upper arm; and

a first right arm portion disposed close to the second support member rightward with respect to the longitudinally inteimediate portion of the upper arm, and

wherein the lower arm includes:

a second left arm portion disposed close to the first support member leftward with respect to the longitudinally intermediate portion of the lower arm; and

a second right arm portion disposed close to the second support member rightward with respect to the longitudinally intermediate portion of the lower aim.

10. The leaning vehicle according to claim 4 , wherein both the first wheel and the second wheel are front wheels, and wherein both the upper arm and the lower arm are disposed forward from the base member.

11. The leaning vehicle according to claim 4 , further comprising:

a single rear wheel disposed at a center portion of the leaning vehicle in the vehicle-width direction,

wherein both the first wheel and the second wheel are front wheels.

12. The leaning vehicle according to claim 1 , further comprising:

a first brake mechanism braking the first wheel; and

a second brake mechanism braking the second wheel.

13. The leaning vehicle according to claim 1 , wherein the restriction member is fixed to the first support member and restricts a rotation of the upper arm and the lower arm beyond a predetermined angle by abutting the at least one of the upper arm and the lower arm.

14. The leaning vehicle according to claim 13 , further comprising a further restriction member, the further restriction member being fixed to the second support member and restricting the rotation of the upper arm and the lower arm beyond the predetermined angle by abutting the at least one of the upper arm and the lower arm.

15. A vehicle leaning unit, comprising:

a base member adaptable turnably around a turning center;

an upper arm whose longitudinally intermediate portion is pivoted to the base member at a height;

a lower arm whose longitudinally intermediate portion is pivoted to the base member at another height below the height to pivot the upper arm to the base member;

a first support member disposed on one of opposite sides of the base member in a vehicle-width direction;

a second support member disposed on the other of the opposite sides of the base member in the vehicle-width direction;

a first wheel pivoted to the first support member;

a second wheel pivoted to the second support member; and

a restriction member restricting a rotation angle range of at least one of the upper arm and the lower arm by abutting the at least one of the upper arm and the lower arm,

wherein the upper arm, the lower arm, the first support member and the second support member constitute a parallel link mechanism,

wherein the first wheel is movable integrally with the first support member in a turning direction of the base member,

wherein the second wheel is movable integrally with the second support member in the turning direction of the base member, and

wherein according to turning of the base member, all of the upper arm, the lower ann, the first support member, the second support member, the first wheel and the second wheel turn around the turning center of the base member.