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公开(公告)号：US10676898B2
公开(公告)日：2020-06-09
申请号：US16326754
申请日：2017-12-14
Inventor： Kiwamu Takahashi , Taihei Maehara , Kazushige Mori , Yoshifumi Takebayashi , Natsuki Nakamura
Abstract: In a hydraulic drive system of a work machine which drives a plurality of actuators using three or more pumps, for an operation not including traveling, a highly efficient combined operation in a front implement and excellent combined operability of a swing and the front implement are enabled, while for an operation including traveling, a highly efficient traveling operation and a highly efficient combined operation of traveling and the front implement are enabled, and a sufficient operation speed of the front implement is achieved. To this end, each of the flow rates of the first, second, and third pumps (101, 201, 301) can be controlled independently by performing the load sensing control, and in a combined operation for driving a boom (511) and an arm (512), ether one of them is driven by the first pump while the other one is driven by the second pump, and the swing is driven by the third pump. In the traveling operation, the maximum capacity of the first and second pumps is switched to the maximum capacity for the traveling operation and driven by an open center circuit. In a combined operation of traveling and the front implement, the front implement is driven by performing the load sensing control using the third pump.
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公开(公告)号：US11142882B2
公开(公告)日：2021-10-12
申请号：US16080387
申请日：2017-02-22
Inventor： Yoshifumi Takebayashi , Hajime Yoshida , Kazushige Mori , Natsuki Nakamura , Taihei Maehara
Abstract: To provide a small hydraulic excavator, which even may have an upperstructure formed such that at least its rear end swings within a body width range and having a limited installation space for devices, that allows an accumulator to be disposed and allows the accumulator to be protected from external force generated during work. The present invention relates to a rear small-swing type mini excavator that includes an accumulator 30 accommodating and recovering potential energy and hydraulic energy used by at least one of drives of an undercarriage 1, an upperstructure 2 formed such that its rear end swings within the body width range of the undercarriage 1, and a working device 3. In the rear small-swing type mini excavator, the accumulator 30 is disposed between a valve block 26 and a front longitudinal board 41 of a longitudinal board member included in a main frame 10 along the front longitudinal board 41, and a pipe connected to the accumulator 30 and the valve block 26 is disposed closer to the accumulator 30 and the valve block 26.
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公开(公告)号：US11111650B2
公开(公告)日：2021-09-07
申请号：US16492482
申请日：2018-05-23
Inventor： Kiwamu Takahashi , Taihei Maehara , Takeshi Ishii , Yoshifumi Takebayashi , Natsuki Nakamura , Daisuke Oka
Abstract: When a swing motor and a boom cylinder are driven simultaneously, a hydraulic drive system appropriately adjusts a distribution of torques between hydraulic pumps and feeds back a torque actually consumed by the hydraulic pump for actuating the swing motor accurately to the hydraulic pump for actuating the boom cylinder. To that end, when boom raising and swinging are performed simultaneously, the hydraulic drive system corrects an allowable torque of a hydraulic pump 302 that supplies a hydraulic fluid to a swing motor 3c so as to be lowered by a certain ratio, reducing allowable torques of hydraulic pumps 102 and 202 that supply a hydraulic fluid to a boom cylinder 3a by torques consumed by the hydraulic pumps 102 and 202 that supply a hydraulic fluid to the swing motor 3c.
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公开(公告)号：US10280592B2
公开(公告)日：2019-05-07
申请号：US15376863
申请日：2016-12-13
Inventor： Kiwamu Takahashi , Shingo Kishimoto , Yoshifumi Takebayashi , Kazushige Mori , Natsuki Nakamura
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.
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公开(公告)号：US10060451B2
公开(公告)日：2018-08-28
申请号：US15030383
申请日：2014-11-26
Inventor： Kiwamu Takahashi , Yasutaka Tsuruga , Kazushige Mori , Yoshifumi Takebayashi , Natsuki Nakamura , Yasuharu Okazaki , Kenji Yamada
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.
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Patent Agency Ranking
公开(公告)号：US11332911B2
公开(公告)日：2022-05-17
申请号：US16328345
申请日：2017-09-29
Inventor： Yoshifumi Takebayashi , Hajime Yoshida , Natsuki Nakamura , Daisuke Oka
Abstract: Provided is a construction machine that can prevent a machine body from being lowered since a blade is not put into a float state even where a misoperation is made by an operator when the machine body is in a jacked-up state, and that can perform a favorable leveling operation by putting the blade into the float state in accordance with an operator's operation when the machine body is not in the jacked-up state. A hydraulic excavator includes a controller 42 that determines whether or not the machine body is in a jacked-up state and controls a float valve 41. In the case where it is determined that the machine body is not in the jacked-up state, the controller 42 changes over the float valve 41 to a float position V and invalidates an operation of a blade control valve 22, in accordance with a float instruction. In the case where it is determined that the machine body is in the jacked-up state, the controller 42 holds the float valve 41 in a reference position IV and validates the operation of the blade control valve 22, irrespectively of the presence or absence of the float instruction.
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公开(公告)号：US09835180B2
公开(公告)日：2017-12-05
申请号：US14763000
申请日：2013-11-15
Inventor： Kiwamu Takahashi , Shingo Kishimoto , Yoshifumi Takebayashi , Kazushige Mori , Natsuki Nakamura
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.
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公开(公告)号：US10995473B2
公开(公告)日：2021-05-04
申请号：US16641712
申请日：2019-01-31
Inventor： Yoshifumi Takebayashi , Hajime Yoshida , Natsuki Nakamura , Daisuke Oka
Abstract: Provided is a construction machine that can prevent a machine body from being lowered without placing a blade in a floating state when the machine body is jacked up, even if the operator performs an erroneous operation, and that can perform favorable leveling work by placing the blade in the floating state when the machine body is not jacked up. A hydraulic excavator includes a pressure sensor that detects the pressure in a bottom-side oil chamber of a blade cylinder, and a controller that switches between validation and invalidation of a floating command and a lowering command for a blade operation device. In the case where the pressure detected by the pressure sensor is less than a predetermined value, the controller switches a solenoid selector valve to an interruption position to invalidate the floating command when a forward stroke of the operation lever is equal to or more than a reference value. In the case where the pressure detected by the pressure sensor is equal to or more than the predetermined value, the controller holds the solenoid selector valve in a communication position to validate the floating command when the forward stroke of the operation lever is equal to or more than the reference value.
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公开(公告)号：US10655647B2
公开(公告)日：2020-05-19
申请号：US15883357
申请日：2018-01-30
Inventor： Yoshifumi Takebayashi , Kiwamu Takahashi , Kazushige Mori , Natsuki Nakamura
Abstract: Pressure compensating valves not fully closing at the stroke end are employed, and upon the operator's operation for the traveling, pilot primary pressure is reduced and supplied to remote control valves 34c-34h of non-travel operating devices. Thus, the inflow of the hydraulic fluid into non-travel actuators is suppressed and a necessary amount of hydraulic fluid for travel motors is secured in travel combined operation. Accordingly, when saturation occurs in a construction machine's hydraulic drive system performing the load sensing control due to combined operation with a great load pressure difference between two actuators, deceleration/stoppage of an actuator on the low load pressure side is prevented by preventing full closure of the pressure compensating valve on the low load pressure side, while also preventing deceleration/stoppage of a high load pressure actuator by securing a necessary amount of hydraulic fluid for the high load pressure actuator.
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公开(公告)号：US10107311B2
公开(公告)日：2018-10-23
申请号：US14769922
申请日：2014-04-21
Inventor： Kiwamu Takahashi , Yasutaka Tsuruga , Yoshifumi Takebayashi , Kazushige Mori , Natsuki Nakamura
Abstract: To cope with a variety of flow rate balance required of two actuators flexibly in combined operations driving two actuators of high maximum demanded flow rates at the same time while suppressing the wasteful energy consumption caused by the throttle pressure loss in a pressure compensating valve, the arrangement is such that when the demanded flow rate of a boom cylinder 3a is lower than a prescribed flow rate, the boom cylinder 3a is driven only by hydraulic fluid delivered from a single flow type main pump 202 and when the demanded flow rate of the boom cylinder 3a is higher than the prescribed flow rate, the hydraulic fluid delivered from the single flow type main pump 202 and hydraulic fluid delivered from a first delivery port 102a of a split flow type main pump 102 are merged together and the boom cylinder 3a is driven by the merged fluids. Further, when the demanded flow rate of an arm cylinder 3b is lower than a prescribed flow rate, the arm cylinder 3b is driven only by hydraulic fluid delivered from a second delivery port 102b of the split flow type main pump 102 and when the demanded flow rate of the arm cylinder 3b is higher than the prescribed flow rate, hydraulic fluid delivered from the first delivery port 102a and hydraulic fluid delivered from the second delivery port 102b are merged together and the arm cylinder 3b is driven by the merged fluids.
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