Kabushiki Kaisha Komatsu Seisakusho

Komatsu Corporation

Tadao Karakama

Naoki Ishizaki

Teruo Akiyama

Sadao Nunotani

Nobumi Yoshida

Jun Maruyama

Kazuo Uehara

Mitsumasa Akashi

Toshiro Takano

Yosuke Oda

Nobuhisa Honda

Shuji Hori

Kazunori Ikei

Masamitsu Takeuchi

Keisuke Taka

Masayuki Tanaami

Hiroshi Endo

Seita Hayashi

Suji Hori

Kouji Yamashita

Naoki Isizaki

Kohji Yamashita

Flow control apparatus in a hydraulic circuit

Working machine fall preventive valve apparatus

Flow reinforcement directional control valve for a hydraulic circuit

Displacement control system for variable displacement type hydraulic pump

A multiple valve includes first and second valve units respectively having first and second valve bodies. The first and second valve bodies have respective spool bores therein; and a respective spool is inserted in the spool bore of each of the first and second valve bodies. The first and second valve bodies of the first and second valve units also have inlet ports, tank ports, and first and second blocks having mounting holes, the blocks and a respective valve body being fixedly coupled together by means of stud bolts. The first block has a first threaded hole on one side surface thereof for receiving the stud bolt, and a second threaded hole on another side surface thereof for receiving a cover bolt. A pump passage, a main passage and a tank passage extend between the one side surface and the another side surface of the first block, and a stud bolt extends through the second block and is engaged with the first threaded hole. A cover is fixedly mounted on the another side surface of the first block by a cover bolt which is engaged with the second threaded hole, the cover having a cut-out groove therein for communicating the pump passage with the main passage.

Multiple valve unit for pressurized fluid supply system

Hydraulic pilot valve

Pressurized fluid supply system

Hydraulic circuit for operating plural actuators and its pressure

A hydraulic circuit including a pressure compensating valve, which aims at preventing the delay in operation of the valve due to the time required for the inflow of fluid in amount corresponding to stroke volume thereof, thereby improving the response of thereof. This hydraulic circuit includes a pressure compensating valve (3) provided between the delivery side of a hydraulic pump (1) and the inlet of a directional control valve (4), the pressure compensating valve (3) being arranged to be urged by the pressure applied to first pressure receiving portion (6) to position (D) where the area of opening thereof is kept maximum, and also urged by the pressure applied to second pressure receiving portion (8) to position (E) where the area of opening thereof is kept minimum, the portions (6) and (8) being connected with the outlet and inlet sides of the valve (4). The circuit includes a hydraulic cylinder (30) adapted to push the valve (3) to the position (D) and whose piston elongating chamber (31) is connected with an exterior pressurized fluid supply (11) and whose piston retracting chamber (34) is connected with the portion (6) so that when the valve (4) is located at neutral position (A) the valve (3) is held at position (D).

Hydraulic circuit including pressure compensating valve

Hydraulic circuit for swivel working machine

Hydraulic circuit system

A pressure control system in which a pressure in a back pressure chamber of a flow control valve is controlled according to a throttle opening of a pilot valve to locate stationary the valve body of the flow control valve at a position corresponding to the throttle opening of the pilot valve. In the system, a fixed throttle is provided in an oil passage extended to the back pressure chamber of the flow control valve, thereby applying a dampering action to the valve body.

Hydraulic pressure control system

Operating lever device

Pilot valve

Growing community of inventors

Kanagawa, Japan

Tadao Karakama