Komatsu Corporation

Toyomi Kataoka

Naoki Ishizaki

Nobumi Yoshida

Yuusuke Miyamoto

Keita Nagaoka

A valve device switching between an open position and a close position, the open position allowing passage of oil through a gap between two ports in a spool bore from a small-diameter portion of a spool via a notch formed in a large-diameter portion of the spool, the close position blocking passage of oil through the gap between the two ports by the large-diameter portion, wherein the notch of the large-diameter portion has an inner bottom face at a portion located on a center side of the spool and is open to an outer peripheral space of the small-diameter portion and an outer peripheral surface of the large-diameter portion, and is formed such that an opening width of an opening at the outer peripheral surface is larger than a width of the inner bottom face.

Valve device

A pressurized hydraulic fluid supply apparatus capable of merging or separating a plurality of hydraulic pump lines according to the driving states of a plurality of actuators. The pressurized hydraulic fluid supply apparatus has a merge/separation valve,that merges or separates the hydraulic fluids delivered under pressure by the first hydraulic pump,and the second hydraulic pump,The merge/separation valve,is set to a flow separation state upon driving of the second hydraulic actuator,and is preferentially shifted to a flow merging state when the third hydraulic actuator,is driven. Hence, even when a manually driven operation valve is used, the merge/separation valve,is automatically switched between the flow separation state and the flow merging state according to the operation of the operation valve. This apparatus prevents an unintended flow rate difference between the first and second actuators from being produced upon driving of the third actuator.

Growing community of inventors

Oyama, Japan

Toyomi Kataoka