中科微点-全球专利检索

  1. Login
  2. Sign Up

Search Results

6 records (took 0.033 seconds)

    Work vehicle
    2.
    发明授权
    Work vehicle 有权

    公开(公告)号：US11313103B2

    公开(公告)日：2022-04-26

    申请号：US16641484

    申请日：2019-03-22

    Applicant: Hitachi Construction Machinery Co., Ltd.

    Inventor： Keishi Mizutani ,  Ryousuke Matsutani ,  Shinichiro Tanaka

    IPC: B60T17/22 ,  E02F9/20 ,  E02F9/22 ,  B60T13/68

    Abstract: A work vehicle provided with a loading hydraulic circuit (A), including at least a main hydraulic pump (31), a lift arm cylinder (8) and a control valve (32), an auxiliary hydraulic pump (31), a negative parking brake device (PB), and a parking brake releasing hydraulic circuit (B2), in which the vehicle includes: a loading operation hydraulic circuit (B1) located upstream of the parking brake releasing hydraulic circuit; an emergency flow path (80) for supplying the pressure oil discharged from the auxiliary hydraulic pump to the parking brake device through the loading operation hydraulic circuit in an emergency; and a valve unit (81) located in the emergency flow path. If the pressure of the parking brake releasing hydraulic circuit is lower than the brake release pressure to release the braking state of the parking brake device, the valve unit is switched to the communicating position.

    Wheel loader
    3.
    发明授权
    Wheel loader 有权

    公开(公告)号：US11027775B2

    公开(公告)日：2021-06-08

    申请号：US16640363

    申请日：2019-03-05

    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

    Inventor： Shinichiro Tanaka ,  Hiroyasu Kodera

    IPC: B62D5/07 ,  E02F9/22

    Abstract: The operability can be improved when the rotational speed of the engine is low and the working device actuator and the steering actuator are operated in a combined manner, while the configuration of prioritizing the operation of the steering actuator is maintained. A control device (70) included in a wheel loader (1) determines whether a working device (4) is in load lifting operation or not based on the pressure that is between a working device directional switching valve (44) and an orifice (45) and is detected by a pressure sensor (71), and reduces the opening area of a steering control valve (37) when determining that the rotational speed of an engine (14) detected by a rotational speed sensor (72) is equal to or less than a predetermined threshold (Ns) and a working device is in the load lifting operation.

    Hydraulic drive device for work vehicle
    4.
    发明授权
    Hydraulic drive device for work vehicle 有权

    公开(公告)号：US10900200B2

    公开(公告)日：2021-01-26

    申请号：US16328840

    申请日：2018-03-07

    Applicant: Hitachi Construction Machinery Co., Ltd.

    Inventor： Shinichiro Tanaka

    IPC: E02F9/22 ,  F15B11/10 ,  F15B11/02 ,  F15B11/028

    Abstract: This hydraulic drive device for a work vehicle includes a main pump (1) of a variable displacement type or a fixed displacement type discharging pressure oil, a main flow passage (F1) for supplying pressure oil of the main pump to an actuator, a sub-pump (5) of a fixed displacement type discharging pressure oil, a sub-flow passage (F2) for making pressure oil of the sub-pump merge with the main flow passage and supplying the pressure oil to the actuator (2), a merging directional valve (6A) for connecting or cutting off the main flow passage and the sub-flow passage, a controller (30) for controlling operation of the merging directional valve, and a relief valve (7A) arranged in the sub-flow passage, in which the relief valve has a pressure override characteristic having a tendency that the relief pressure increases from a cracking pressure to a set pressure as a relief flow rate increases.

Patent Agency Ranking