Electric suspension device and motorcycle

• US 8,770,594 B2
• Filed: 09/26/2013
• Issued: 07/08/2014
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: KYB Corp., Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Kayaba Industry Company Limited, Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Amano, Yuki, Tominaga, Shuji
• Primary Examiner(s): BROWN, DREW J
• Application Number:
  US14/037,522
• Publication Number:
  US 20140091539A1
• Time in Patent Office: 285 Days
• Field of Search: 280/6.157, 280/5.515, 188/297, 188/266.2, 188/322.5, 188/313, 188/266.1, 267/218, 267/64.26
• US Class Current: 280/6.157
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2300/12 Cycles; Motorcycles
• CPC Class Codes: B62K 25/26 for rear wheel
• CPC Class Codes: B62K 25/286 the shock absorber being connected to the chain-stay via a linkage mechanism
• CPC Class Codes: F16F 9/185 Bitubular units where compression of gas leads to a clear spring action F16F9/062
• CPC Class Codes: F16F 9/466 Throttling control, i.e. regulation of flow passage geometry F16F9/464, F16F9/465 take precedence

Abstract

An electric suspension device includes a cylinder, a sub-tank, a first oil passage and a second oil passage, a damping force adjusting valve, and a damping force adjusting motor. The cylinder is rotatable about a mounting axis. The first oil passage connects a first inner oil chamber and an outer oil chamber. The second oil passage connects the first inner oil chamber of the cylinder and an oil chamber of the sub-tank. The first and second oil passages are disposed outside an inner tube and an outer tube, and share a portion with each other. The first and second oil passages are entirely disposed on the same side with respect to a reference plane.

Claims

1. An electric suspension device for a motorcycle that absorbs shocks between a vehicle body frame and a rear wheel, the electric suspension device comprising:

a cylinder including an inner tube filled with oil, a piston that partitions an interior of the inner tube into a first inner oil chamber and a second inner oil chamber, and an outer tube surrounding the inner tube, the outer tube defining around the inner tube an outer oil chamber that is continuous with the second inner oil chamber, the cylinder arranged to be supported on the vehicle body frame so as to be rotatable about a mounting axis extending in a left-right direction of the electric suspension device;

a sub-tank including an interior partitioned into an oil chamber filled with oil and a gas chamber filled with gas;

a first oil passage disposed outside the inner tube and the outer tube, the first oil passage being arranged to connect the first inner oil chamber and the outer oil chamber;

a second oil passage disposed outside the inner tube and the outer tube, the second oil passage being arranged to connect the first inner oil chamber and the oil chamber of the sub-tank;

a damping force adjusting valve to apply resistance to oil flowing through the first oil passage; and

a damping force adjusting motor to adjust an opening degree of the damping force adjusting valve;

wherein

the first oil passage and the second oil passage share a portion with each other, and an entirety of the first oil passage and an entirety of the second oil passage are disposed on a same side with respect to a reference plane that is orthogonal or substantially orthogonal to the mounting axis and includes a center line of the cylinder.

2. The electric suspension device according to claim 1, further including an upper mount joined to the cylinder, the upper mount being coupled to the vehicle body frame so as to be rotatable about the mounting axis;

wherein

at least a portion of the first oil passage and at least a portion of the second oil passage are provided inside the upper mount; and

the damping force adjusting valve and the damping force adjusting motor are held on the upper mount.

3. The electric suspension device according to claim 1, wherein the damping force adjusting valve and the damping force adjusting motor are disposed on the same side as the first oil passage and second oil passage with respect to the reference plane.

4. The electric suspension device according to claim 1, wherein the sub-tank is disposed on the same side as the first oil passage and the second oil passage with respect to the reference plane.

5. The electric suspension device according to claim 1, further comprising a hydraulic jack arranged to adjust a vehicle height, and a pump unit to feed oil to the hydraulic jack;

wherein

the pump unit is disposed on an opposite side to the first oil passage and the second oil passage with respect to the reference plane.

6. The electric suspension device according to claim 5, wherein the sub-tank, the damping force adjusting motor, and the pump unit are disposed farther to a rear of the motorcycle than the mounting axis.

7. The electric suspension device according to claim 1, wherein the damping force adjusting motor extends in a direction inclined with respect to the reference plane in a plan view of the electric suspension device.

8. The electric suspension device according to claim 1, wherein the second oil passage includes a first end portion and a second end portion, the second end portion being disposed closer to the sub-tank than the first end portion in a circulation direction of the oil;

and

the second end portion of the second oil passage on a side of the sub-tank is disposed farther away with respect to the center line of the cylinder than the first end portion of the second oil passage on a side of the cylinder.

9. The electric suspension device according to claim 8, wherein at least a portion of the second oil passage is inclined with respect to the center line of the cylinder such that the second end portion on the side of the sub-tank is located farther away with respect to the center line of the cylinder than the first end portion on the side of the cylinder.

10. The electric suspension device according to claim 1, wherein the second oil passage includes a flow passage linearly extending from an outer surface of the electric suspension device toward an interior of the electric suspension device.

11. A motorcycle comprising:

a vehicle body frame;

a rear wheel that is swingable in an up-down direction of the motorcycle with respect to the vehicle body frame; and

the electric suspension device according to claim 1 arranged to absorb shocks between the vehicle body frame and the rear wheel.