公开(公告)号：US20180305898A1

公开(公告)日：2018-10-25

申请号：US15768841

申请日：2016-12-05

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Hiroyuki KOBAYASHI ,  Hiroshi SAKAMOTO ,  Yasutaka TSURUGA

IPC: E02F9/22

CPC classification number: E02F9/2228 ,  E02F3/435 ,  E02F9/2235 ,  E02F9/2267 ,  E02F9/2271 ,  E02F9/2285 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/04 ,  F15B11/08 ,  F15B2211/30525 ,  F15B2211/526 ,  F15B2211/6653

Abstract: A construction machine that can ensure an initial response that varies in accordance with a hydraulic actuator in a similar fashion to a case of adopting a hydraulic pilot-type operation device is provided. A controller 100 of a hydraulic excavator outputs a command current for driving the corresponding solenoid proportional valve (i.e. some of solenoid proportional valves 41a, 41b, 42a to 42d, 43a to 43d, 44a and 44b) in response to an operation signal from an electric lever-type work operation device 2a or 2b, and includes a correction function to correct the command current such that the command current is higher than a target current corresponding to an operation amount of the operation device for preset predetermined time at a time of starting to operate the operation device from a neutral position thereof. This correction function corrects only the command current to the bucket solenoid proportional valves 44a and 44b.

公开(公告)号：US20150377258A1

公开(公告)日：2015-12-31

申请号：US14767480

申请日：2014-03-17

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

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

IPC: F15B11/16 ,  F15B11/17

CPC classification number: F15B11/166 ,  E02F3/325 ,  E02F9/2239 ,  E02F9/2285 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/17 ,  F15B2211/20553 ,  F15B2211/20576 ,  F15B2211/253 ,  F15B2211/2656 ,  F15B2211/30535 ,  F15B2211/30595 ,  F15B2211/6658 ,  F15B2211/7135 ,  F15B2211/7142 ,  F15B2211/88

Abstract: In addition to a main pump 102 having two delivery ports 102a and 102b and performing the load sensing control, two subsidiary pumps 202 and 302 for the load sensing control for respectively performing assist driving on a boom cylinder 3a and an arm cylinder 3b are provided. When driving the boom cylinder 3a or the arm cylinder 3b, a selector valve 141 or 241 is switched and flows of hydraulic fluid are merged together and supplied to the boom cylinder 3a or the arm cylinder 3b. When driving actuators other than the boom cylinder 3a or the arm cylinder 3b, only the hydraulic fluid from the main pump is supplied to the actuators. In short, the hydraulic drive system is configured so that two specific actuators having great demanded flow rates and tending to have a great load pressure difference between each other when driving at the same time can be driven with hydraulic fluid delivered from separate delivery ports. With this configuration, wasteful energy consumption due to pressure loss in a pressure compensating valve can be suppressed, and in cases of driving an actuator of a low demanded flow rate, the hydraulic pump can be used at a point where the volume efficiency is high.

Abstract translation: 除了具有两个输送口102a和102b并执行负载感测控制的主泵102之外，还提供了用于分别在动臂缸3a和臂缸3b上执行辅助驱动的负载感测控制的两个辅助泵202和302。 当驱动动臂缸3a或臂缸3b时，选择阀141或241被切换并且液压流体的流动被合并在一起并供给到动臂缸3a或臂缸3b。 当驱动除了动臂缸3a或臂缸3b之外的致动器时，仅将来自主泵的液压流体供给到致动器。 简而言之，液压驱动系统被构造成使得具有很大要求流量并且倾向于在同时驱动时彼此之间具有很大负载压力差的两个特定致动器可以由从单独的输送口输送的液压流体驱动。 由此，能够抑制因压力补偿阀的压力损失引起的浪费的能量消耗，在驱动低要求流量的致动器的情况下，可以在体积效率高的点使用液压泵。

公开(公告)号：US20240368857A1

公开(公告)日：2024-11-07

申请号：US18688633

申请日：2023-03-16

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Seiji HIJIKATA ,  Yasutaka TSURUGA ,  Masatoshi HOSHINO ,  Shou FURUKAWA ,  Ryou YAGISAWA

IPC: E02F9/22 ,  E02F9/08 ,  F15B1/02

Abstract: Provided is a work machine including a flow control valve serving as a flow control mechanism that controls a flow rate of pressurized fluid from a hydraulic pump to a hydraulic actuator via a first control valve. A controller of the work machine, when the pressurized fluid is supplied to the hydraulic actuator from only an accumulator, drives a second control valve such that a meter-in side of the hydraulic actuator and the accumulator are connected to each other, drives the first control valve such that a meter-out side of the hydraulic actuator and a tank are connected to each other, and drives the flow rate control mechanism such that a flow of the pressurized fluid from the hydraulic pump to the hydraulic actuator via the first control valve is interrupted.

公开(公告)号：US20240344297A1

公开(公告)日：2024-10-17

申请号：US18683384

申请日：2022-10-31

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Kento KUMAGAI ,  Shinya IMURA ,  Yasutaka TSURUGA ,  Takaaki CHIBA ,  Shinjirou YAMAMOTO ,  Hiroaki AMANO ,  Shinji NISHIKAWA ,  Akihiro NARAZAKI

IPC: E02F9/22

CPC classification number: E02F9/2235 ,  E02F9/2296

Abstract: The present invention intends to provide a work machine that can execute speed control of an actuator and torque control of a swing motor by a simple configuration at the time of combined operation to simultaneously drive the swing motor and the other actuator. For this purpose, a controller calculates a pump target flow rate on the basis of an actuator target flow rate and a swing target flow rate and calculates a target meter-in opening area of an actuator directional control valve on the basis of the actuator target flow rate, a pump pressure, and an actuator meter-in pressure. The controller calculates target torque of the swing motor on the basis of the input amount of operation devices and output values of posture sensors and calculates a swing target meter-out pressure on the basis of the target torque and a swing meter-in pressure. The controller calculates a target meter-out opening area of a swing directional control valve on the basis of the swing target meter-out pressure and a swing meter-out pressure.

公开(公告)号：US20230323635A1

公开(公告)日：2023-10-12

申请号：US18023784

申请日：2021-12-17

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Masatoshi HOSHINO ,  Seiji HIJIKATA ,  Yasutaka TSURUGA ,  Ryou YAGISAWA ,  Shou FURUKAWA

IPC: E02F9/22

CPC classification number: E02F9/2235 ,  E02F9/2246 ,  E02F9/2296

Abstract: Provided is a work machine capable of achieving both low fuel consumption and ensuring of workability. The work machine is configured to, in a state where an output of an engine or hydraulic pump has increased to an increase threshold (S12: Yes) with the rotational speed being at a first rotational speed (S11: Yes), raise the rotational speed from the first rotational speed to a second rotational speed (S13); in a process of raising the rotational speed to the second rotational speed, output, to a regulator, a signal instructing reduction in the discharge rate (S14) so as to keep the output of the engine or hydraulic pump constant; and after the rotational speed has reached the second rotational speed, output, to the regulator, a signal instructing increase in the discharge rate (S16) so as to make the output of the engine or hydraulic pump have a value corresponding to a request load.

公开(公告)号：US20230323634A1

公开(公告)日：2023-10-12

申请号：US18025085

申请日：2021-12-15

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Masatoshi HOSHINO ,  Seiji HIJIKATA ,  Yasutaka TSURUGA

IPC: E02F9/22 ,  E02F9/20 ,  F15B13/044 ,  F15B15/26

CPC classification number: E02F9/2203 ,  E02F9/2296 ,  E02F9/2004 ,  F15B13/044 ,  F15B15/26 ,  E02F9/2285 ,  E02F9/2292 ,  F15B2211/426

Abstract: The object of the invention of the present application resides in provision of a work machine that can be improved in operability at start of an action of a hydraulic actuator in a fine operation in which an operation lever is operated by a small amount. To this end, on the basis of a signal from a first timing sensor and a signal from a second timing sensor, a machine body controller controls, before the first timing is sensed, the pump delivery flow rate to a minimum delivery flow rate, controls, after the first timing is sensed but before the second timing is sensed, the pump delivery flow rate to a predetermined delivery flow rate that is greater than the minimum delivery flow rate, and controls, after the second timing is sensed, the pump delivery flow rate to a delivery flow rate according to an operation amount of the operation lever.

公开(公告)号：US20230184265A1

公开(公告)日：2023-06-15

申请号：US17910521

申请日：2021-07-13

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Masatoshi HOSHINO ,  Seiji HIJIKATA ,  Yasutaka TSURUGA

IPC: F15B11/042 ,  E02F9/22 ,  E02F9/20 ,  F15B21/08

CPC classification number: F15B11/0423 ,  E02F9/2228 ,  E02F9/2282 ,  E02F9/2004 ,  E02F9/2296 ,  F15B21/082 ,  F15B21/087 ,  E02F3/435

Abstract: A work machine includes: a hydraulic actuator that is driven by a hydraulic fluid from a hydraulic pump; an open-center directional control valve that is arranged on a center bypass line, and controls a flow of the hydraulic fluid to be supplied to the hydraulic actuator; a CB cut valve arranged between a directional control valve and a hydraulic working fluid tank on the center bypass line; and a machine controller that controls an opening of the CB cut valve. The machine controller restricts the opening of the CB cut valve when operation on the hydraulic actuator is in a fine operation state in which the operation on the hydraulic actuator is within a predetermined range representing a region of fine operation, and the fine operation state is continued longer than a predetermined period, and fully opens the CB cut valve otherwise.

公开(公告)号：US20220333348A1

公开(公告)日：2022-10-20

申请号：US17641038

申请日：2021-03-18

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Kento KUMAGAI ,  Shinya IMURA ,  Yasutaka TSURUGA ,  Takaaki CHIBA ,  Hiroaki AMANO ,  Shinji NISHIKAWA ,  Akihiro NARAZAKI ,  Genroku SUGIYAMA ,  Shinjiro YAMAMOTO

IPC: E02F9/22 ,  E02F9/20 ,  F15B13/02

Abstract: Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.

公开(公告)号：US20210002868A1

公开(公告)日：2021-01-07

申请号：US16979338

申请日：2019-06-21

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Kento KUMAGAI ,  Shinya IMURA ,  Genroku SUGIYAMA ,  Katsuaki KODAKA ,  Yasutaka TSURUGA

IPC: E02F9/22

Abstract: To provide a work machine that makes it possible to drive actuators faster and more accurately by supplying flows to the actuators accurately at target rates without depending on load variations in a case where the machine body is controlled automatically by command inputs of a controller, while high operability is ensured for manual operation by an operator. In a case where a machine control function is cancelled via a machine control switch, a controller cancels limitation of the flow rate of a hydraulic fluid supplied to a plurality of directional control valves, the limitation being performed by the auxiliary flow rate control devices, and in a case where the machine control function is selected via the machine control switch, the controller causes the auxiliary flow rate control devices to limit the flow rate of the hydraulic fluid supplied to the plurality of directional control valves.

公开(公告)号：US20160333900A1

公开(公告)日：2016-11-17

申请号：US15030383

申请日：2014-11-26

Applicant: Hitachi Construction Machinery Co., Ltd.

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

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

CPC classification number: F15B13/06 ,  E02F3/325 ,  E02F9/2235 ,  E02F9/2267 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/161 ,  F15B11/17 ,  F15B2211/20507 ,  F15B2211/20523 ,  F15B2211/20546 ,  F15B2211/20553 ,  F15B2211/20576 ,  F15B2211/253 ,  F15B2211/255 ,  F15B2211/2656 ,  F15B2211/50554 ,  F15B2211/6355 ,  F15B2211/67

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 the 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 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. The torque feedback circuit 112v includes first and second variable pressure reducing valves 112g and 112q.

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，从而随着输出压力的增加而减小最大转矩T12max。 扭矩反馈电路112v包括第一和第二可变减压阀112g和112q。