Motorcycle with active rear suspension unit providing improved braking

• US 20020040821A1
• Filed: 10/10/2001
• Published: 04/11/2002
• Est. Priority Date: 10/10/2000
• Status: Abandoned Application

• Current Assignee: Ducati Motor Holding SPA (Volkswagen AG)
• Original Assignee: Ducati Motor Holding SPA (Volkswagen AG)
• Inventors: Preziosi, Filippo, Domenicali, Claudio
• Application Number:
  US09/974,603
• Publication Number:
  US 20020040821A1
• Time in Patent Office: Days
• US Class Current: 180/227
• CPC Class Codes: B62K 25/283 for cycles without a pedal crank, e.g. motorcycles
• CPC Class Codes: B62K 25/286 the shock absorber being connected to the chain-stay via a linkage mechanism

Abstract

A motorcycle (1) having a frame (2) mounted on a front wheel (3) and on a rear wheel (4), each wheel (3, 4) operationally cooperating with a corresponding suspension unit (5, 6) connected to the frame (2), the wheels (3, 4) resting on a support surface (S); the rear suspension unit (6) including a reaction rod (15) selectively yieldable along a longitudinal axis (W) and having two opposing ends (15A, 15B), the ends (15A, 15B) being selectively approachable to each other when the vehicle (1) is braked in order to obtain lowering of the barycenter of the motorcycle (1) towards the support surface (S) to enable greater braking of the vehicle (1) and greater vehicle stability during this braking.

Claims

1. A motorcycle (1) comprising:

a frame (2) mounted on a front wheel (3) and on a rear wheel (4), each wheel (3, 4) operationally cooperating with a corresponding front and rear suspension unit (5, 6) connected to the frame (2), the wheels (3, 4) resting on a support surface (S),

wherein the rear suspension unit (6) comprises a member (15) having two opposing ends (15A, 15B), of which a first (15A) operationally cooperates with the frame (12) and the second (15B) operationally cooperates with the rear wheel (4), characterised in that the member (15) acting as the reaction rod is selectively yieldable along its longitudinal axis (W), the ends (15A, 15B) of said member (15) being selectively approachable to each other when the vehicle (1) is braked in order to obtain lowering of the barycentre of the motorcycle (1) towards the support surface (S) to enable greater braking of the vehicle (1) and greater vehicle stability during this braking, and

control means (41) structured and arranged to act on said member (15) to modify its extension during braking.

2. A motorcycle as claimed in claim 1, wherein the member (15) acting as the reaction rod is a hydraulic actuator (15) which acts as a rigid reaction rod during unbraked movement of the vehicle.

3. A motorcycle as claimed in claim 2, wherein the hydraulic actuator (15) comprises a cylinder (20) within which there moves a piston (21) arranged to define within this cylinder (20) two variable-volume chambers, these chambers communicating with a hydraulic circuit (40) provided with means (27) for controlledly varying the pressure of the fluid present in said chambers (20A, 20B) and for enabling the piston (21) to move within the cylinder (20), said piston operationally cooperating with one chosen from said frame (2) and said rear wheel (4), said cylinder (20) operationally cooperating with the other of said frame (2) and said rear wheel (4).

4. A motorcycle as claimed in claim 3, wherein the means for varying the pressure of the fluid in the cylinder chambers (20A, 20B) are a valve unit (27) connected to and controlled by the means (41) which control the variation in the extension of the member acting as the reaction rod (15), said control means acting on said valve unit to modify, when predetermined braking conditions are present, the extension of said member (15).

5. A motorcycle as claimed in claim 3, wherein the hydraulic circuit (40) forms part of the vehicle engine lubrication circuit.

6. A motorcycle as claimed in claim 3, wherein the hydraulic circuit (40) comprises a reservoir (30), a pumping member (33) and a fluid accumulator arranged to provide a substantially instantaneous high rate of pressurized fluid flow to the actuator (15) to suddenly modify its extension.

7. A motorcycle as claimed in claim 1, wherein the control means is a microprocessor unit (41).

8. A motorcycle as claimed in claim 7, wherein the control unit (41) is connected to a sensor (42) sensing a braking command applied to the front wheel brake (43), to a sensor (45) measuring the sinking of the fork (46) of the front suspension unit (5), to a sensor (48) measuring the motorcycle speed, and to a position sensor (47) for the front wheel (4) which senses when this latter rises from the ground (S).

9. A motorcycle as claimed in claim 8, wherein the unit (41) is connected to a sensor (50) measuring the throttling of the motorcycle engine air intake duct.

10. A motorcycle as claimed in claim 8, wherein the unit (41) is connected to a sensor (49) measuring the variation in the extension of the member acting as the reaction rod (15).