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。

公开(公告)号：US20170284064A1

公开(公告)日：2017-10-05

申请号：US15506894

申请日：2015-03-16

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Seiji HIJIKATA ,  Kouji ISHIKAWA ,  Yasutaka TSURUGA ,  Masatoshi HOSHINO ,  Kiwamu TAKAHASHI

IPC: E02F9/22 ,  F15B21/14

CPC classification number: E02F9/2217 ,  E02F9/2012 ,  E02F9/2225 ,  E02F9/2228 ,  E02F9/2267 ,  E02F9/2285 ,  E02F9/2296 ,  F15B1/024 ,  F15B13/0433 ,  F15B21/14 ,  F15B2013/0428 ,  F15B2211/20546 ,  F15B2211/212 ,  F15B2211/50536 ,  F15B2211/50554 ,  F15B2211/6316 ,  F15B2211/6355 ,  F15B2211/67 ,  F15B2211/88

Abstract: The construction machine includes: a control valve that switchingly supplies hydraulic fluid from a hydraulic pump to a hydraulic actuator; a control valve drive device that supplies pilot secondary hydraulic fluid to the control valve in accordance with an operation of an operation lever device; a pilot hydraulic pump that supplies pilot primary hydraulic fluid to the control valve drive device; a pressure accumulation device that recovers return hydraulic fluid returned from the hydraulic actuator. The construction machine further includes: a check valve provided in a line between the pilot hydraulic pump and the control valve drive device; a pressure reducing valve that supplied the hydraulic fluid accumulated in the pressure accumulation device; a flow rate reduction device; and a controller that controls the flow rate reduction device in accordance with the pressure in the line between the check valve and the control valve drive device.

公开(公告)号：US20160376769A1

公开(公告)日：2016-12-29

申请号：US15262500

申请日：2016-09-12

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Kazushige MORI ,  Yasutaka TSURUGA ,  Kiwamu TAKAHASHI ,  Yoshifumi TAKEBAYASHI

IPC: E02F9/22 ,  E02F9/02 ,  F15B11/16

CPC classification number: E02F9/2267 ,  E02F3/325 ,  E02F3/964 ,  E02F9/02 ,  E02F9/2225 ,  E02F9/2228 ,  E02F9/2232 ,  E02F9/2235 ,  E02F9/2271 ,  E02F9/2285 ,  E02F9/2292 ,  E02F9/2296 ,  E02F9/267 ,  F04B17/03 ,  F15B11/163 ,  F15B11/165 ,  F15B13/026 ,  F15B19/002 ,  F15B2211/20523 ,  F15B2211/20546 ,  F15B2211/20553 ,  F15B2211/30535 ,  F15B2211/3111 ,  F15B2211/3116 ,  F15B2211/323 ,  F15B2211/355 ,  F15B2211/522 ,  F15B2211/528 ,  F15B2211/5756 ,  F15B2211/6054 ,  F15B2211/7058 ,  F15B2211/7135 ,  F15B2211/782

Abstract: A hydraulic drive system for a track device of crawler type has right and left hydraulic track motors. The hydraulic drive system is capable of correcting for skew occurring in the straight line traveling of the track device. A traveling test is conducted upon shipment from a factory. If skew is noted during the test, a plug disposed on the side of a valve opening-side pressure receiving portion of a pressure compensating valve for the track which is lower in speed is removed and, replaced with an adjusting mechanism-mounted plug having an adjusting pin. The pin is operated so as to strengthen a biasing force of a target compensating differential pressure adjusting spring. An opening in the pressure compensating valve is thereby corrected in an opening direction and a flow rate to one of the left and right track motors is thereby adjusted to be equal to the other motor.

公开(公告)号：US20160265561A1

公开(公告)日：2016-09-15

申请号：US15030384

申请日：2014-11-26

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Kiwamu TAKAHASHI ,  Yasutaka TSURUGA ,  Yoshifumi TAKEBAYASHI ,  Kazushige MORI ,  Natsuki NAKAMURA ,  Yasuharu OKAZAKI ,  Hiroyuki NOBEZAWA ,  Kenji YAMADA

IPC: F15B11/16 ,  E02F9/22 ,  F15B13/06 ,  F15B11/17 ,  F15B13/02

CPC classification number: F15B11/165 ,  E02F3/325 ,  E02F3/964 ,  E02F9/2066 ,  E02F9/2228 ,  E02F9/2235 ,  E02F9/2267 ,  E02F9/2285 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/17 ,  F15B13/026 ,  F15B13/06 ,  F15B20/007 ,  F15B2211/20523 ,  F15B2211/20546 ,  F15B2211/20553 ,  F15B2211/20576 ,  F15B2211/6652 ,  F15B2211/6655

Abstract: The object is to make it possible to efficiently utilize rated output torque of the prime mover by performing total torque control with high precision through precise detection of absorption torque of the other hydraulic pump by use of a purely hydraulic structure and feedback of the absorption torque to one hydraulic pump's side. For this purpose, the hydraulic drive system is equipped with: a torque feedback circuit 112v which is supplied with delivery pressure of a main pump 202 and load sensing drive pressure, modifies the delivery pressure of the main pump 202 to achieve a characteristic simulating the absorption torque of the main pump 202, and outputs the modified pressure; and a torque feedback piston 112f which is supplied with an output pressure of the torque feedback circuit and controls displacement of a main pump 102 so as to decrease the displacement of the main pump 102 and thereby decrease maximum torque T12max as the output pressure increases.

Abstract translation: 目的是通过使用纯水力结构和吸收扭矩的反馈来精确地检测另一液压泵的吸收扭矩，通过高精度地执行总转矩控制来有效地利用原动机的额定输出转矩 一个液压泵的一侧。 为此，液压驱动系统配备有：被供应主泵202的输送压力和负载感测驱动压力的扭矩反馈电路112v，改变主泵202的输送压力，以实现模拟吸收的特性 主泵202的转矩，输出修正压力; 以及扭矩反馈活塞112f，其被提供有扭矩反馈回路的输出压力并且控制主泵102的位移，以便减小主泵102的位移，从而随着输出压力增加而减小最大扭矩T12max。

公开(公告)号：US20160258133A1

公开(公告)日：2016-09-08

申请号：US15027016

申请日：2014-11-26

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Yasutaka TSURUGA ,  Kiwamu TAKAHASHI ,  Yasuharu OKAZAKI ,  Hiroyuki NOBEZAWA ,  Kenji YAMADA

IPC: E02F9/22 ,  F15B13/08 ,  F15B13/02 ,  F15B11/17

CPC classification number: E02F9/2235 ,  E02F3/325 ,  E02F9/2228 ,  E02F9/2232 ,  E02F9/2267 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/17 ,  F15B13/025 ,  F15B13/026 ,  F15B13/0803 ,  F15B20/007 ,  F15B2211/20523 ,  F15B2211/20546 ,  F15B2211/20553 ,  F15B2211/20576 ,  F15B2211/25 ,  F15B2211/6652 ,  F15B2211/6655

Abstract: It is an object of the present invention to accurately detect the absorption torque of the other of two hydraulic pumps by a purely hydraulic structure and feed the absorption torque to one of the two hydraulic pumps, thereby to accurately perform a total torque control, effectively utilize a rated output torque of a prime mover, and enhance mountability. To achieve the object, there are provided: a torque feedback circuit 31 to which the delivery pressure of a first hydraulic pump 1a and a load sensing drive pressure are introduced, which modifies the delivery pressure of a second hydraulic pump 1b to provide a characteristic simulating the absorption torque of the second hydraulic pump 1b, and which outputs the modified pressure; and torque feedback pistons 32a, 32b to which the output pressure of the torque feedback circuit 31 is introduced, and which control the capacity of the first hydraulic pump 1a to decrease the capacity of the first hydraulic pump 1a and decrease a maximum torque T1max as the output pressure becomes higher. The torque feedback circuit 31 includes pressure dividing restrictor parts 34a, 34b, pressure dividing valves 35a, 35b, and relief valves 37a, 37b.

Abstract translation: 本发明的目的是通过纯粹的液压结构精确地检测两个液压泵中的另一个的吸收扭矩，并将吸收扭矩馈送到两个液压泵中的一个，从而精确地执行总转矩控制，有效地利用 原动机的额定输出扭矩，并增强了安装性。 为了实现该目的，提供了：引入第一液压泵1a的输出压力和负载感测驱动压力的扭矩反馈电路31，其改变第二液压泵1b的输送压力，以提供模拟的特性 第二液压泵1b的吸收扭矩，并输出修正压力; 以及引入扭矩反馈回路31的输出压力的转矩反馈活塞32a，32b，并且控制第一液压泵1a的容量降低第一液压泵1a的容量，并将最大转矩T1max减小为 输出压力变高。 扭矩反馈回路31包括分压限制部34a，34b，分压阀35a，35b，溢流阀37a，37b。