# US 8,783,696 B2 · Vehicle-height adjustment apparatus of motorcycle

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- Number: US 8,783,696 B2
- Document ID: US8783696B2
- Status: Granted
- Kind: B2
- Application number: 13/800,813
- Filed: 2013-03-13
- Published: 2014-03-27
- Granted: 2014-07-22
- Earliest claimed: 2012-09-25
- Assignees: Showa Corporation
- Applicants: Showa Corporation
- Inventors: Yosuke Murakami
- Web page: https://patentgrep.com/patent/US8783696B2

## CPC

- B60G 17/08: Characteristics of fluid dampers (adjusting fluid dampers in general F16F9/44 - F16F9/53)
- B60G 13/08: hydraulic
- B62K 25/00: Axle suspensions (for vehicles in general B60G)
- F16F 9/56: Means for adjusting the length of, or for locking, the spring or damper, e.g. at the end of the stroke {(F16F9/50 takes precedence; for telescopic gas springs or dampers F16F9/0245; vehicle suspension locking arrangements B60G17/005)}
- B60G 2300/12: Cycles; Motorcycles
- B60G 2500/30: Height or ground clearance
- B62K 2025/045: {Suspensions with ride-height adjustment}
- B60G: VEHICLE SUSPENSION ARRANGEMENTS (air-cushion vehicles B60V; {cycle suspensions B62K25/00})
- B62K: CYCLES; CYCLE FRAMES; CYCLE STEERING DEVICES; RIDER-OPERATED TERMINAL CONTROLS SPECIALLY ADAPTED FOR CYCLES; CYCLE AXLE SUSPENSIONS; CYCLE SIDECARS, FORECARS, OR THE LIKE
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION

## Abstract

In a vehicle-height adjustment apparatus of a motorcycle having the hydraulic jack attached to the damper, damping force characteristics of a damper are stabilized, the influence of the charged gas pressure of an oil reservoir chamber is eliminated, and the sealing performance of a hydraulic jack is reduced. In the vehicle-height adjustment apparatus of a motorcycle, a back pressure chamber is provided on a side opposite to a jack chamber, with a plunger being interposed therebetween inside a hydraulic jack, and this back pressure chamber is communicated with a hydraulic chamber inside a damper tube.

## Claims

### Claim 1

A vehicle-height adjustment apparatus of a motorcycle including a damper in which a piston rod slides in a hydraulic chamber inside a damper tube, and a suspension spring,
the vehicle-height adjustment apparatus comprising:
a hydraulic jack provided on one of the damper tube and the piston rod;
a jack chamber provided inside the hydraulic jack;
a plunger inserted in the jack chamber;
a spring bearing supported by the plunger, wherein the suspension spring is interposed between the spring bearing and a spring bearing provided on the other one of the damper tube; and
a hydraulic pump that is caused to perform a pumping operation by extension and compression movements of the piston rod relative to the damper tube and supplies and drains oil of the hydraulic chamber inside the damper tube to and from the jack chamber of the hydraulic jack, whereby adjusting a vehicle height,
wherein the vehicle-height adjustment apparatus further comprises a back pressure chamber that is provided on a side opposite to the jack chamber, with the plunger being interposed therebetween inside the hydraulic jack, and that is communicated with the hydraulic chamber inside the damper tube.

### Claim 2 (depends on 1)

The vehicle-height adjustment apparatus of the motorcycle according to claim 1, wherein a pressure receiving area of the plunger on a side of the jack chamber is made different from a pressure receiving area of the plunger on a side of the back pressure chamber inside the hydraulic jack.

### Claim 3 (depends on 1)

The vehicle-height adjustment apparatus of the motorcycle according to claim 1, wherein the pressure receiving area of the plunger on the side of the jack chamber is made substantially the same as the pressure receiving area of the plunger on the side of the back pressure chamber inside the hydraulic jack.

### Claim 4 (depends on 1)

The vehicle-height adjustment apparatus of the motorcycle according to claim 1, wherein the jack chamber and the back pressure chamber inside the hydraulic jack are communicated with a piston-side hydraulic chamber and a rod-side hydraulic chamber inside the damper tube, respectively, and a hydraulic pressure of the jack chamber is made different from a hydraulic pressure of the back pressure chamber by a pressure of a damping force of the damper.

### Claim 5 (depends on 2)

The vehicle-height adjustment apparatus of the motorcycle according to claim 2, wherein the jack chamber and the back pressure chamber inside the hydraulic jack are communicated with a piston-side hydraulic chamber and a rod-side hydraulic chamber inside the damper tube, respectively, and a hydraulic pressure of the jack chamber is made different from a hydraulic pressure of the back pressure chamber by a pressure of a damping force of the damper.

### Claim 6 (depends on 3)

The vehicle-height adjustment apparatus of the motorcycle according to claim 3, wherein the jack chamber and the back pressure chamber inside the hydraulic jack are communicated with a piston-side hydraulic chamber and a rod-side hydraulic chamber inside the damper tube, respectively, and a hydraulic pressure of the jack chamber is made different from a hydraulic pressure of the back pressure chamber by a pressure of a damping force of the damper.