公开(公告)号：US20170089038A1

公开(公告)日：2017-03-30

申请号：US15376863

申请日：2016-12-13

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Kiwamu TAKAHASHI ,  Shingo KISHIMOTO ,  Yoshifumi TAKEBAYASHI ,  Kazushige MORI ,  Natsuki NAKAMURA

IPC: E02F9/20 ,  F15B13/06 ,  E02F9/22 ,  F15B11/16

CPC classification number: E02F9/207 ,  E02F3/325 ,  E02F3/964 ,  E02F9/2095 ,  E02F9/2235 ,  E02F9/2296 ,  F04B35/04 ,  F15B11/16 ,  F15B11/165 ,  F15B13/06 ,  F15B2211/20515 ,  F15B2211/20538 ,  F15B2211/20546 ,  F15B2211/255 ,  F15B2211/30555 ,  F15B2211/6055 ,  F15B2211/6309 ,  F15B2211/6313 ,  F15B2211/6651 ,  F15B2211/6652 ,  F15B2211/71 ,  F15B2211/76

Abstract: An electrically-operated hydraulic work machine drives an actuator with a hydraulic pump driven by an electric motor and exercises load sensing control by controlling the rotation speed of the electric motor. The useful life of an electrical storage device, which is an electrical power source for the electric motor, is increased by suppressing the horsepower consumption of the hydraulic pump. This prolongs the operating time of the electrically-operated hydraulic work machine, and reduces the size of the electric motor. A controller exercises load sensing control over a variable displacement main pump by controlling the rotation speed of the electric motor, and provides the main pump with a torque control device that reduces the delivery rate of the main pump when the delivery pressure of the main pump increases, or provides the controller with a control algorithm that performs the same function as the torque control device.

公开(公告)号：US20150330415A1

公开(公告)日：2015-11-19

申请号：US14763000

申请日：2013-11-15

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Kiwamu TAKAHASHI ,  Shingo KISHIMOTO ,  Yoshifumi TAKEBAYASHI ,  Kazushige MORI ,  Natsuki NAKAMURA

IPC: F15B11/16 ,  F15B13/02

CPC classification number: F15B11/165 ,  E02F9/2232 ,  E02F9/2253 ,  E02F9/2285 ,  E02F9/2296 ,  F15B11/163 ,  F15B11/168 ,  F15B13/026 ,  F15B2211/20553 ,  F15B2211/253 ,  F15B2211/30535 ,  F15B2211/329 ,  F15B2211/40515 ,  F15B2211/428 ,  F15B2211/50536 ,  F15B2211/6058 ,  F15B2211/6355 ,  F15B2211/67 ,  F15B2211/7135

Abstract: An object of the invention is to achieve a travel speed known in the art during travelling operation, improve energy efficiency by reducing energy loss, and obtain favorable travel operability less susceptible to effects from variations in a travel load and changes in a pump delivery pressure when travelling operation is performed through operation of a travel lever over a half stroke range or less. A variable restrictor valve 80 is disposed in parallel with a flow sensing valve 50 of an engine speed sensing valve unit 13. A travel pilot pressure is adapted to act in an opening direction of the variable restrictor valve 80. The variable restrictor valve 80 is set to have a continuously increasing opening area from a full closure to a maximum with an increasing travel pilot pressure. Travel flow control valves 6d and 6e have an opening area that allows a predetermined flow rate QT required for traveling to be obtained even when a target LS differential pressure is decreased to a second specified value Pa3 when the travel lever is fully operated. In a first half of a spool stroke, the travel flow control valves 6d and 6e have an opening area approximate to an opening area of comparative example 1.

Abstract translation: 本发明的一个目的是在行驶中实现本领域已知的移动速度，通过减少能量损失来提高能量效率，并获得较不易受行驶负载变化和泵输送压力变化影响的良好行驶操作性能 行驶操作通过行程杆在半冲程范围以下的操作来进行。 可变节流阀80与发动机速度检测阀单元13的流量检测阀50平行设置。行驶先导压力适于沿可变节流阀80的打开方向作用。可变节流阀80被设定 随着行驶先导压力的增加，开启面积从全封闭到不断增加。 行程流量控制阀6d和6e具有开口面积，即使当行程杆完全操作时目标LS差压降低到第二规定值Pa3时，也能够获得行驶所需的预定流量QT。 行程流量控制阀6d和6e在滑阀冲程的前半部分中具有与比较例1的开口面积近似的开口面积。