Komatsu Corporation

Yasuhiko Takeuchi

Takuya Uemura

Hiroki Yamamoto

Takashi Noda

Naomi Kobayashi

Toshio Ibuki

Kazumasa Teramoto

A restraining roller of a hook winch has a roller middle part and first and second roller end parts. The roller middle part is formed in a columnar shape. Each of the first and second roller end parts is formed in a roughly circular truncated cone shape. The widths of the first and second roller end parts are greater than the diameter of a wire rope. A difference in diameter between an inner end and outer end of each of the first and second roller end parts is less than the diameter of the wire rope. Taper angles of the first and second roller end parts are different from each other.

Winch for pipelayer and pipelayer equipped with same

A pipelayer includes a pilot pressure control unit. The pilot pressure control unit supplies hydraulic fluid to a pilot port of a warm-up control valve so that the warm-up control valve enters an open state when a winch control valve is in the closed state. The pilot pressure control unit drains hydraulic fluid from the pilot port of the warm-up control valve so that the warm-up control valve enters the closed state when the winch control valve is in the open state. The stroke amount from the stroke end of the closed side of the spool of the warm-up control valve when the meter-out opening of the warm-up control valve is fully closed is larger than the stroke amount from the stroke end of the closed side of the spool of the winch control valve when the meter-in opening of the winch control valve is fully closed.

Pipelayer

A warm-up pilot pressure control unit adjusts pilot pressure inputted to a first flow channel open/close unit so that the flow channel open/close unit is switched to an open state when a warm-up start state is entered under the necessary condition that a first winch operation member is in a neutral position. When the first flow channel open/close unit is in the open state, a first pump displacement adjustment unit adjusts the displacement of a first hydraulic pump so that the differential pressure between a first pump hydraulic circuit and a first warm-up hydraulic circuit becomes constant at a predetermined set pressure.

Pipe layer and warm-up method for pipe layer

An operator's room (cab) situated in a region above the power train of a work machine which has an opening for maintenance purposes formed passing through a floor frame and a lid member for closing off the opening installed on the floor frame, and which achieves both good quietness characteristics and good workability during servicing. In the operator's cab of the invention, the floor section of the floor frame has a hollow box-type structure, and the lid member has a hollow box-type structure which fits into the opening in the floor section of the floor frame, and furthermore, a sealing member for sealing a gap between the floor section of the floor frame and the lid member is provided.

Growing community of inventors

Katano, Japan

Yasuhiko Takeuchi