Hitachi Astemo Ltd.

Showa Corporation

Hitachi Automotive Systems, Ltd.

Yasuhiro Aoki

Makoto Yamakado

Nobuyuki Ichimaru

Ryusuke Hirao

Osamu Yuno

Umi Tanabe

A front fork includes a spring that is provided between a first cylindrical body and a second cylindrical body and applies a force in a direction to separate the first cylindrical body and the second cylindrical body, and a spring seat portion that is provided on an outer peripheral surface of the first cylindrical body and receives a first end of the spring. The spring seat portion includes a fixing portion that is fixed to the first cylindrical body, a spring seat body that is made of metal and receives the spring, and a third cylindrical body that is disposed between an inner peripheral surface of the spring seat body and the outer peripheral surface of the first cylindrical body and reduces a frictional force when the spring seat body rotates.

Front fork

This shock absorber includes a friction generating member which is provided at a position on a side defined by a seal member of a cylinder and comes into sliding contact with a piston rod. The friction generating member has an annular elastic rubber portion which comes into sliding contact with the piston rod and a base portion to which the elastic rubber portion is fixedly attached. The elastic rubber portion is formed such that an upstream side and a downstream side are able to communicate with each other when a differential pressure between a one side chamber of the cylinder and a reservoir chamber reaches a predetermined pressure.

Shock absorber

A shock absorber includes an outer tube, an inner tube fitted to the outer tube so as to be able to move forward and backward, a cylinder provided inside the outer tube and extending inside the inner tube, a rod extending from an end portion of the inner tube exposed from the outer tube to an inside of the cylinder, and a piston which is provided on the rod and divides the inside of the cylinder to form a gas chamber. On an outer peripheral surface of the piston, a first lubricating member, a first seal member, and a second seal member are provided in this order from a side closest to the gas chamber to a side away from the gas chamber. The members are in sliding contact with an inner peripheral surface of the cylinder.

A front fork includes a first shock absorber and a second shock absorber disposed respectively on both sides of a vehicle wheel. The first shock absorber includes a set of tubes configured to slide relative to each other; damping force generation parts configured to generate a damping force in accordance with the sliding of the tubes; and a spring configured to urge the set of tubes in a stretching direction. The second shock absorber includes a set of tubes configured to slide relative to each other; and a coil spring configured to urge the set of tubes in the stretching direction.

Electrorheological fluid is loaded in a shock absorberas hydraulic fluid. The shock absorbercontrols a generated damping force by producing a potential difference in an electrode passageto thus change viscosity of electrorheological fluid flowing in the electrode passage. A plurality of partition wallsis provided in the electrode passageformed between an inner tubeand an electrode tube. Due to this configuration, a plurality of helical flow passagesis formed in the electrode passage. In this case, the flow passagesare each provided with a flow passage cross-sectional area change portion that allows the flow passageto have a larger cross-sectional area on one side spaced apart from an entranceAside (an intermediate region F) at least compared to the entranceAside of the extension-side flow passage(an inflow region E).

Cylinder apparatus

Electrorheological fluid is loaded in a shock absorber () as hydraulic fluid (). The shock absorber () controls a generated damping force by causing a potential difference to be generated in an electrode passage () and controlling a viscosity of the electrorheological fluid passing through this electrode passage (). A plurality of partition walls () is provided between an inner cylinder () and an electrode cylinder (). By being configured in this manner, the shock absorber () forms a plurality of helical flow passages () between the inner cylinder () and the electrode cylinder (). In this case, an inclination angle of each of the partition walls () is not constant, and each of the partition walls () includes a sharply inclined portion (A) inclined at a large angle on at least an entrance side of an extension-side flow passage ().

A damping force control type shock absorber capable of achieving both air bleeding performance and damping force responsiveness at reduced cost. When a pilot valve () is closed during the extension stroke of a piston rod (), a cylinder upper chamber (A) is communicated with a back-pressure chamber () through a passage () including an orifice (), a communicating passage (), a pilot chamber (), and a communicating passage (). At this time, the cylinder upper chamber (A) is not communicated with a cylinder lower chamber (B); therefore, damping force responsiveness is ensured. Further, because there is no need to provide a check valve in the passage, it is possible to suppress an increase in manufacturing cost. Further, air entering the pilot chamber () moves upward through the communicating passage (). Therefore, the air can be discharged into the cylinder upper chamber (A) through the passage ().

Damping force control type shock absorber

A suspension apparatus includes a first tube and a second tube that are telescopic and that are disposed on a vehicle body side and on a wheel side, respectively; a cylinder that is provided in the first tube; a rod that is provided in the second tube; a piston that is provided on the rod, slidingly contacts with an inner circumferential surface of the cylinder, and forms a first gas chamber on a side of the first tube; a coil spring configured to urge the first tube and the second tube in an extension direction; and a spring receiving member that is disposed at a position on a second tube side from a movable region of the piston, the coil spring being disposed between the spring receiving member and the second tube.

Suspension apparatus

A tire load calculation section of a controller calculates tire load factors of the respective wheels. A target tire load-factor calculation section calculates a tire load factor average value (&#x3b7;) obtained by averaging the tire load factors (&#x3b7;) of the respective wheels as a target tire load factor. A target tire vertical-load calculation section calculates target tire vertical loads (Fzref) for the respective wheels so that the tire load factors of the respective wheels become equal to the tire load factor average value. A vertical-load control section and a suspension control section control thrusts of electromagnetic dampers for the respective wheels so as to achieve the target tire vertical loads.

Vehicle behavior control apparatus

In a spring leg of a front fork, the capacity of a rebound air spring chamber is expanded and a stable rebound reaction force is ensured, and the spring leg of the front fork is provided with a sub-tank including an air chamber communicating with a rebound air spring chamber.

Spring leg of front fork

A front fork spring leg, which is capable of stably maintaining air spring, has an inward-facing seal member, an outward-facing seal member, and a piston ring arranged on an outer periphery of a guide of a guide rod sequentially in this order along an axial direction of the guide from a side close to an inner air spring chamber toward a side far from the inner air spring chamber. The inward-facing seal member has a lip which is slidably in contact with an inner periphery of the guide cylinder, with this lip being oriented toward the inner air spring chamber. The outward-facing seal member has a lip which is slidably in contact with the inner periphery of the guide cylinder, with this lip being oriented in an opposite direction to the inner air spring chamber.

Growing community of inventors

Fukuroi, Japan

Yasuhiro Aoki