Toyota Jidosha Kabushiki Kaisha

Toyoda Koki Kabushiki Kaisha

Kabushiki Kaisha Saginomiya Seisakusho

Kaname Saito

Kyosuke Haga

Hideya Kato

Kenichi Fukumura

Seiho Kawakami

Tatsuya Sagiyama

Takashi Matsushima

Hitoshi Iizuka

Miko Suzuki

Fumihiko Baba

A testing apparatus of a steering system is provided to correctly detect load in a direction in which steering reaction force acts, the load being applied to the steering system. A tie rod connected to a rack of the steering system is connected to a steering-angle vibrating unit via a torque lever, relay links and a drive link. A front link of the drive link and a link disposed parallel to the torque lever are provided in a swingable manner. Both ends of each of the relay links are respectively connected to the torque lever and the link disposed parallel to the torque lever, and the torque lever is swingable with respect to the link in a direction in which road-surface reaction force acts. Transducers are provided at intermediate portions of the relay links, respectively. A vertically-vibrating unit is connected via the torque lever to the rack.

Testing apparatus of steering system

A hydraulic power steering system includes a pump, a flow control valve, and a bypass control valve. The flow control valve responds to a pressure drop across a metering orifice disposed in a fluid supply passage so as to control the flow rate of operational fluid by bypassing part of the operational fluid to a reservoir. A spring chamber of the flow control valve is connected to the supply passage through a control orifice. The bypass control valve is disposed between the spring chamber and the reservoir so as to increase the amount of bypassed fluid by controlling the pressure in the spring chamber. The bypass control valve has a control spool, a load pressure introduction port connected to the upstream side of the control orifice for leading the load pressure to a first end of the control spool and a pilot port connected to the downstream side of the control orifice for leading the pressure in the spring chamber of the flow control valve to a second end of the control spool. Moreover, a pressure receiving area of the second end of the control spool is smaller than that of the first end of the control spool. Accordingly, a spring having a small spring constant can be used in the bypass control valve, even when the control spool is controlled within a short stroke.

Hydraulic power steering apparatus

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Toyota, Japan

Kaname Saito