Hydraulic drive unit
    2.
    发明申请
    Hydraulic drive unit 有权
    液压驱动单元

    公开(公告)号:US20050144938A1

    公开(公告)日:2005-07-07

    申请号:US10520144

    申请日:2003-07-09

    摘要: To permit releasing an excessive rod pressure from a first hydraulic cylinder and also effectively using pressure oil of its rod chamber upon performing such an operation that pressure oil is fed to a bottom chamber of a second hydraulic cylinder, a hydraulic drive unit is provided with a boom cylinder, an arm cylinder, a communication line communicating a rod chamber of the boom cylinder and a bottom chamber of the arm cylinder with each other, and a switching valve arranged on the communication line for communicating or shutting off the communication line in accordance with a rod pressure of the boom cylinder. When an arm-crowding single operation is performed and by its digging counterforce, a rod pressure of the boom cylinder rises to a high pressure of at least a predetermined pressure, the switching valve is changed over from a shut-off position to a communicating position to feed pressure oil from the rod chamber of the boom cylinder to the bottom chamber of the arm cylinder. The boom cylinder is hence caused to automatically extend, thereby avoiding lifting of a body of a hydraulic excavator.

    摘要翻译: 为了允许从第一液压缸释放过大的杆压力,并且在执行将压力油供给到第二液压缸的底部室的操作时,还可以有效地使用其杆室的压力油,液压驱动单元设置有 动臂缸,斗杆缸,将动臂缸的杆室与斗杆缸的底部室连通的连通管线,以及设置在通信线路上的切换阀,用于根据通信线路进行通信或切断通信线路 动臂缸的杆压力。 当执行搂紧单次操作并且通过其挖掘反作用力时,动臂缸的杆压力升至至少预定压力的高压,切换阀从关闭位置切换到连通位置 将压力油从动臂缸的杆室输送到臂缸的底部腔室。 因此,动臂缸被自动延伸,从而避免了液压挖掘机的主体的提升。

    Pressure compensating valve spool positioned by difference in pressure
receiving areas for load and inlet pressures
    3.
    发明授权
    Pressure compensating valve spool positioned by difference in pressure receiving areas for load and inlet pressures 失效
    压力补偿阀由压力接收区域负载和入口压力的差异定位

    公开(公告)号:US5152140A

    公开(公告)日:1992-10-06

    申请号:US640440

    申请日:1991-02-06

    IPC分类号: E02F9/22 F15B13/04

    摘要: A hydraulic drive system has a hydraulic pump (1), an actuator (2), a flow control valve (5) disposed between the hydraulic pump and the actuator, a pressure compensating valve (8; 8A; 8B) having a valve spool (23; 23A; 23B) that controls the differential pressure (Pz-PLS) across the flow control valve, and a pump delivery rate control device (9) for controlling a flow rate of the hydraulic fluid delivered from the hydraulic pump dependent on a differential pressure (Pd-PLS) between a pump pressure and a load pressure of the actuator. The pressure compensating valve has a first control chamber (30; 30A) subjected to the load pressure (PLS) of the actuator such that the load pressure acts on a first pressure receiving section (28; 28A) of the valve spool to urge the valve spool in the valve-opening direction, a second control chamber (29; 29A) subjected to the inlet pressure (Pz) of the flow control valve such that the inlet pressure acts on a second pressure receiving section (27; 27A) of the valve spool to urge the valve spool in the valve-closing direction, and a target differential pressure setting arrangement (31, 50, 51; 31B, 51) for urging the valve spool in the valve-opening direction. A damping capability to the actuator (2) is provided by setting pressure receiving area (Az) of the second pressure receiving section (27; 27A) to be greater than a pressure receiving area (ALS) of the first pressure receiving section (28; 28A).

    摘要翻译: PCT No.PCT / JP90 / 01310 Sec。 371日期1991年2月6日 102(e)日期1991年2月6日PCT 1990年10月11日PCT PCT。 出版物WO91 / 05958 日期:1991年5月2日。液压驱动系统具有液压泵(1),致动器(2),设置在液压泵和致动器之间的流量控制阀(5),压力补偿阀(8; 8A; 8B )具有控制跨过流量控制阀的差压(Pz-PLS)的阀芯(23; 23A; 23B)和用于控制从所述流量控制阀输送的液压流体的流量的泵输送速率控制装置(9) 液压泵取决于泵压力和执行器的负载压力之间的压差(Pd-PLS)。 压力补偿阀具有受到致动器的负载压力(PLS)的第一控制室(30; 30A),使得负载压力作用在阀芯的第一压力接收部分(28; 28A)上,以推动阀 阀门处于阀打开方向,第二控制室(29; 29A)经受流量控制阀的入口压力(Pz),使得入口压力作用在阀的第二压力接收部分(27; 27A)上 阀芯沿阀关闭方向推压阀芯,以及用于沿阀打开方向推压阀芯的目标压差设定装置(31,50,51; 31B,51)。 通过将第二受压部分(27; 27A)的压力接收面积(Az)设定为大于第一压力接收部分(28; 27)的受压面积(ALS)来提供致动器(2)的阻尼能力。 28A)。

    Hydraulic drive system
    5.
    发明授权
    Hydraulic drive system 失效
    液压驱动系统

    公开(公告)号:US5152143A

    公开(公告)日:1992-10-06

    申请号:US449848

    申请日:1989-12-21

    IPC分类号: E02F9/22 F15B11/00 F15B11/05

    摘要: A hydraulic drive system comprising a prime mover (21), a hydraulic pump (22) driven by the prime mover, a plurality of hydraulic actuators (23-28) driven by hydraulic fluid supplied from the hydraulic pump, a plurality of flow control valves (29-34) for controlling flow of the hydraulic fluid supplied to the actuators, and a plurality of pressure compensating valve (35-40) for controlling respective differential pressures across the respective flow control valves, in which each of the pressure compensating valves applies a control force (f-F.sub.c) in a valve opening direction for setting a target value of the differential pressure across the flow control valve. There are provided a first detector (60) for detecting the target rotational speed (N.sub.0) of the prime mover (21), and controllers (61, 62, 63) for controlling the control force on the basis of the target rotational speed detected by at least the first detector such that the control force (f-F.sub.c) decreases in accordance with a decrease in the target rotational speed.

    摘要翻译: PCT No.PCT / JP89 / 00893 Sec。 371日期1989年12月21日第 102(e)1989年12月21日PCT PCT 1989年8月31日PCT公布。 出版物WO90 / 02268 日本1990年8月3日。一种液压驱动系统,包括原动机(21),由原动机驱动的液压泵(22),多个液压致动器(23-28),由液压泵 ,用于控制供应到致动器的液压流体的流动的多个流量控制阀(29-34)和用于控制横跨各个流量控制阀的相应差压的多个压力补偿阀(35-40),其中 每个压力补偿阀在阀打开方向上施加控制力(f-Fc),以设定跨过流量控制阀的差压的目标值。 提供了用于检测原动机(21)的目标转速(N0)的第一检测器(60)和用于根据由原动机(21)检测到的目标转速控制控制力的控制器(61,62,63) 至少第一检测器,使得控制力(f-Fc)根据目标转速​​的降低而减小。

    Valve apparatus and hydraulic drive system
    7.
    发明授权
    Valve apparatus and hydraulic drive system 失效
    阀门装置和液压驱动系统

    公开(公告)号:US5203678A

    公开(公告)日:1993-04-20

    申请号:US655368

    申请日:1991-02-28

    IPC分类号: E02F9/22 F15B13/04

    摘要: A valve apparatus has a flow control valve having a supply passage communicating with a hydraulic fluid supply source, a load passage communicating with an actuator, and a first meter-in variable restrictor disposed between the supply passage and the load passage and opened dependent on an operation amount there; a first signal passage located downstream of the first variable restrictor and having a passage section for detecting load pressure of the actuator; a tank passage communicating with a reservoir tank; a discharge passage for communicating the first signal passage with the tank passage; and a second variable restrictor provided in the discharge passage and having its opening variable dependent on the operation amount of the flow control valve to produce in the first signal passage a control pressure different from the load pressure, the control pressure in the first signal passage being led to the hydraulic fluid supply source though a second signal passage. An auxiliary restrictor is disposed in the first signal passage to reduce the load pressure detected in the passage section of the first signal passage so that a pressure lower than the detected load pressure is produced in the first signal passage as the control pressure.

    摘要翻译: PCT No.PCT / JP90 / 01407 Sec。 371日期1991年2月28日 102(e)日期1991年2月28日PCT 1990年11月1日PCT PCT。 公开号WO91 / 10833 日期:1991年7月25日。一种阀装置具有流量控制阀,该流量控制阀具有与液压流体供给源连通的供给通道,与致动器连通的负载通道,以及设置在供给通道和 负载通道和开启取决于操作量; 第一信号通道,位于第一可变节流器的下游,并具有用于检测致动器的负载压力的通道部分; 与储罐连通的罐通道; 用于使第一信号通道与油箱通道连通的排出通道; 以及第二可变节流器,其设置在所述排出通道中,其开口变化取决于所述流量控制阀的操作量,以在所述第一信号通道中产生与所述负载压力不同的控制压力,所述第一信号通道中的控制压力为 通过第二个信号通道导致液压流体供应源。 辅助限制器设置在第一信号通道中以减小在第一信号通道的通道部分中检测到的负载压力,使得在第一信号通道中产生低于检测到的负载压力的压力作为控制压力。

    Direction selector valve having load-sensing function
    8.
    发明授权
    Direction selector valve having load-sensing function 失效
    方向选择阀具有负载感应功能

    公开(公告)号:US5161575A

    公开(公告)日:1992-11-10

    申请号:US717537

    申请日:1991-06-19

    摘要: There is disclosed a direction selector valve having function of detecting load. The valve is used in a hydraulic system. A spool has two passage holes extending axially partially through the spool from both side ends. These two passage holes have their respective high-pressure holes. When the spool is in its neutral position, the high-pressure holes are closed off by spool hole walls between bridge ports and actuator ports. The two passage holes further include low-pressure holes which are in communication with tank ports via load check valves mounted in the passage holes, respectively. Guide holes are formed near the front end of one passage hole and in communication with a load-sensing port. A restriction portion is formed on the outer surface of the spool adjacently to the guide holes to control the flow from the load-sensing port to the tank ports. First guide holes and second guide holes which are close to each other are formed near the front end of the other passage hole. The first guide holes are in communication with the load-sensing port even when the spool is in its neutral position. The second guide holes are placed in communication with the load-sensing port after the spool has shifted from its neutral position, connecting the high-pressure holes with the bridge ports. This structure smoothly responds to the load pressure in the actuator.

    摘要翻译: 公开了一种具有检测负载功能的方向选择阀。 阀门用于液压系统。 阀芯具有从两侧端部轴向部分地穿过阀芯延伸的两个通道孔。 这两个通孔具有各自的高压孔。 当阀芯处于其中性位置时,高压孔由桥接口和执行器端口之间的阀芯孔封闭。 两个通道孔还包括分别通过安装在通孔中的负载止回阀与罐口连通的低压孔。 在一个通孔的前端附近形成导向孔,并与负载传感端口连通。 限制部分形成在与引导孔相邻的卷轴的外表面上,以控制从负载感测端口到罐口的流动。 在另一个通孔的前端附近形成彼此靠近的第一导向孔和第二引导孔。 即使当阀芯处于其中立位置时,第一引导孔也与负载感测端口连通。 在阀芯已经从其中立位置移动之后,第二引导孔与负载感测端口连通,将高压孔与桥接口连接。 该结构平滑地响应致动器中的负载压力。

    Hydraulic drive system for civil engineering and construction machine
    9.
    发明授权
    Hydraulic drive system for civil engineering and construction machine 失效
    公路工程施工机械液压驱动系统

    公开(公告)号:US5150574A

    公开(公告)日:1992-09-29

    申请号:US573138

    申请日:1990-09-24

    IPC分类号: E02F9/22 F15B13/04

    摘要: A hydraulic drive system for a construction machine has a flow control valve (5) disposed between a hydraulic pump and an acutator, a pressure compensating valve for controlling a differential pressure across the flow control valve, and a pump delivery rate regulator for controlling a flow rate of the hydraulic fluid delivered from the hydraulic pump dependent on a differential pressure (Pd-PLS) between a pump pressure and a load pressure of the actuator. The pressure compensating valve has a valve body subjected to control forces. A first control force based on the differential pressure across the flow control valve to the valve body urges the valve body in the valve-closing direction. A second predetermined control force urges the valve body in the valve-operating direction; and a third control force based on the differential pressure (Pd-PLS) between the pump pressure and the load pressure of the actuator urges the valve body in the valve-opening direction.

    摘要翻译: PCT No.PCT / JP90 / 00573 Sec。 371 1990年9月24日第 102(e)1990年9月24日PCT PCT 1990年5月1日PCT公布。 WO90 / 13748 PCT公开 日本1990年11月15日。一种用于建筑机械的液压驱动系统具有设置在液压泵和辅助器之间的流量控制阀(5),用于控制流量控制阀两端的压差的压力补偿阀,以及泵 输送速率调节器,用于根据泵压力和致动器的负载压力之间的差压(Pd-PLS)控制从液压泵输送的液压流体的流量。 压力补偿阀具有经受控制力的阀体。 基于流量控制阀与阀体两端的差压的第一控制力在阀关闭方向上推动阀体。 第二预定控制力促使阀体处于阀操作方向; 并且基于泵压力和致动器的负载压力之间的差压(Pd-PLS)的第三控制力促使阀体沿阀打开方向。