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公开(公告)号：US11891781B2
公开(公告)日：2024-02-06
申请号：US17251069
申请日：2019-03-13
Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Inventor： Koji Hyodo , Fumihiro Nakao , Yasunori Miyamoto , Masaki Nukii
CPC classification number: E02F9/2253 , E02F3/283 , E02F9/02 , E02F9/2228 , E02F9/2292 , E02F9/2296 , F15B15/00 , E02F9/2285
Abstract: A loading vehicle is capable of improving work efficiency by adjusting engine rotational speed with high accuracy in accordance with an operation state of the working device. An HST traveling driven wheel loader has an electrically controlled HST pump. A controller is configured to control input torque of the HST pump 31 and solenoid proportional pressure reducing valve is configured to generate control pressure for controlling displacement volume of the pump based on a control signal from the controller. The controller is configured to calculate the displacement volume q of the HST pump based on discharge pressure Pf of a loading hydraulic pump so that maximum input torque Thst of the HST pump decreases as the discharge pressure Pf or input torque of the loading hydraulic pump increases, and output a control signal corresponding to the calculated displacement volume q to the solenoid proportional pressure reducing valve.
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公开(公告)号：US11905682B2
公开(公告)日：2024-02-20
申请号：US17271743
申请日：2019-12-25
Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Inventor： Tetsuji Tanaka , Masaki Nukii , Keisuke Naitou
CPC classification number: E02F9/2253 , E02F3/84
Abstract: Provided is a wheel loader capable of automatically decreasing vehicle speed without making an operator feel discomfort during a loading operation. A wheel loader 1 mounted with a torque converter type traveling drive system comprises a controller 5 configured to control shifting of a transmission 32. When a vehicle body travels forward at vehicle speed corresponding to a second speed stage set greater by one speed stage than the lowest speed stage of the transmission 32 while operating the lift arm 21 upwardly, the controller 5 sets, as a gear ratio of the transmission 32, an intermediate gear ratio between a gear ratio corresponding to the second speed stage and a gear ratio corresponding to a first speed stage, and outputs a signal for selecting a combination of a plurality of gears corresponding to the set gear ratio to each first to fifth solenoid control valves 32A to 32E.
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公开(公告)号：US10947701B2
公开(公告)日：2021-03-16
申请号：US16980055
申请日：2019-09-24
Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Inventor： Koji Hyodo , Tetsuji Tanaka , Isamu Aoki , Masaki Nukii , Yuki Ahiko
Abstract: Provided is a working vehicle capable of, while reducing fuel consumption, improving traveling performance only when high traveling performance is required.
A wheel loader 1 comprises: an engine 3; a variable displacement HST pump 41; a variable displacement HST motor 42 connected to the HST pump 41 through a closed circuit; pressure sensors 72A, 72B configured to load pressure of the HST motor 42; and a controller 5, wherein the controller 5 is configured to, in a case of determining that a load pressure detection value P is included in a predetermined pressure range of greater than load pressure Pα corresponding to flat ground traveling and smaller than load pressure Pγ corresponding to an excavation operation, increase maximum rotational speed of the engine 3 only within the predetermined pressure range.-
公开(公告)号：US11286646B2
公开(公告)日：2022-03-29
申请号：US16973794
申请日：2019-03-13
Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Inventor： Koji Hyodo , Fumihiro Nakao , Yasunori Miyamoto , Masaki Nukii
Abstract: Provided is a loading vehicle in which a control characteristic of traction force can be easily and finely set and changed while a configuration of a hydraulic circuit is simple. An HST traveling driven wheel loader includes an electronically controlled HST pump and HST motor, including a solenoid proportional pressure reducing valve to control displacement volume of the HST pump based on a control signal output from a controller. The controller stores characteristic tables indicating a correlation between discharge pressure of a loading hydraulic pump or an operation state of an engine and a maximum discharge pressure of the HST pump, and when the vehicle speed corresponds to work requiring traction force, outputs a control signal to the solenoid proportional pressure reducing valve so as to obtain the maximum discharge pressure Pm of the HST pump that corresponds to one of the characteristic tables.
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Patent Agency Ranking
公开(公告)号：US11274745B2
公开(公告)日：2022-03-15
申请号：US15756072
申请日：2016-12-14
Applicant: Hitachi Construction Machinery Co., Ltd.
Inventor： Koji Hyodo , Masashi Yamashita , Tetsuji Tanaka , Katsutaka Hara , Masaki Nukii , Isamu Aoki
IPC: F01P11/10 , F16H61/18 , F02B39/16 , F16H59/78 , F02D29/02 , F16H63/50 , F01P7/04 , F02B37/24 , B60W30/184 , B60K11/08 , F02D41/00 , F01P7/16 , B60W50/12 , F01P5/04 , F02D45/00 , F02D29/04 , F16H61/16 , F02D31/00 , F01P5/02
Abstract: To curb temperature rises in a control device for a supercharger and extend the life of the control device for the supercharger, a work vehicle includes a variable geometry supercharger with variable boost pressure, and a working device driven by pressure oil discharged from a working hydraulic pump, the work vehicle further including: a supercharger control device adapted to control the supercharger; a temperature detection device adapted to detect temperature of the supercharger control device; and a main control device adapted to limit at least one of maximum rotational speed of an engine and maximum vehicle speed of the work vehicle in case the temperature of the supercharger control device is above a predetermined temperature as compared to case the temperature of the supercharger control device is below the predetermined temperature.
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公开(公告)号：US10895062B2
公开(公告)日：2021-01-19
申请号：US16641718
申请日：2018-09-28
Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Inventor： Koji Hyodo , Yuki Ahiko , Tetsuji Tanaka , Isamu Aoki , Masaki Nukii , Masashi Yamashita
IPC: E02F9/22 , E02F3/43 , B60W10/06 , B60W10/103 , F02D29/00
Abstract: Provide is a loading vehicle capable of quickly operating an object handling device in the upward direction while traveling forward.
A wheel loader 1 comprises an engine 3, an HST pump 41, an HST motor 42, a forward/reverse changeover switch 62, a step-on amount sensor 610, a pressure sensor 73, and a controller 5. In a case where a specific condition for specifying lifting operation of a lift arm 21 during forward traveling of the vehicle body is satisfied, the controller 5 increases maximum rotational speed of the engine to a predetermined value Nmax2 which is greater than maximum engine rotational speed Nmax1 during traveling on the flat ground, and limit maximum vehicle speed to a predetermined value Vmax2 which is smaller than maximum vehicle speed Vmax1 prior to the lifting operation of the lift arm 2.-
公开(公告)号：US12031299B2
公开(公告)日：2024-07-09
申请号：US17638391
申请日：2021-03-08
Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Inventor： Koji Hyodo , Yasunori Miyamoto , Masaki Nukii
IPC: F16H59/44 , E02F9/22 , F16H59/26 , F16H61/425 , F16H61/47
CPC classification number: E02F9/2253 , F16H59/26 , F16H59/44 , F16H61/425 , F16H61/47
Abstract: Provided is a work vehicle capable of attaining a maximum vehicle speed specification value set in advance for each vehicle body even in the case where a device constituting an HST traveling drive system has deteriorated over time. In a wheel loader 1 equipped with an HST traveling drive system, a controller 5 is configured to, in the case where a detection pressure value P is equal to or less than a switching pressure value Ps corresponding to a switching point in the HST motor 42 between a maximum displacement volume qmax and a minimum displacement volume qmin, and a detection vehicle speed value V is less than an upper limit vehicle speed specification value Vmaxs, limit the minimum displacement volume qmin of the HST motor 42 to a first minimum displacement volume value qmin1 less than a minimum displacement volume specification value qmins that is associated with the upper limit vehicle speed specification value Vmaxs.
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公开(公告)号：US12012725B2
公开(公告)日：2024-06-18
申请号：US17273844
申请日：2018-09-28
Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Inventor： Koji Hyodo , Masaki Yoshikawa , Tetsuji Tanaka , Masaki Nukii
CPC classification number: E02F9/2246 , E02F3/3417 , E02F3/422 , E02F3/431 , E02F9/2289
Abstract: Provided is a loading work vehicle capable of improving work efficiency even when working on a slippery road surface. An HST-traveling-drive wheel loader 1 comprises a step-on amount detection sensor 610, a discharge pressure detection sensor 75, a mode switch device 60, and a controller 5. The controller 5 is configured to: determine whether a limit mode is selected by the mode switch device 60; specify an operation state of the wheel loader 1 when determining that the limit mode is selected; limit maximum traction force to a first set value which is set based on a static friction coefficient μ and vehicle weight when specifying that a bucket 23 is pushed into a natural ground 100; and increase the maximum traction force from the first set value when specifying that excavation of the natural ground 100 is started.
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公开(公告)号：US10773590B2
公开(公告)日：2020-09-15
申请号：US15754300
申请日：2017-02-08
Applicant: Hitachi Construction Machinery Co., Ltd.
Inventor： Masaki Nukii , Koji Hyodo , Isamu Aoki , Tetsuji Tanaka
IPC: B60K17/10 , B60W10/06 , B60W10/103 , B60W10/30 , F01N3/08 , F02D29/04 , B60W10/04 , F02D31/00 , F02D41/02 , F01N9/00 , F01N3/20 , F01N11/00
Abstract: The present invention relates to a work vehicle including an engine, a hydraulic pump, a hydraulic motor to drive wheels, an HST circuit in which the hydraulic pump and the hydraulic motor are connected to each other in the form of a closed circuit, a reducing agent sensor that detects the state of a reducing agent used to clean exhaust gas from the engine, and an engine restrictor that restricts the rotational speed of the engine based on the output from the reducing agent sensor, and the work vehicle further includes a control unit that changes the tilting angle of the hydraulic pump or the hydraulic motor independently of the rotational speed of the engine to a tilting angle associated with minimum travel drive force necessary for self-travel of the work vehicle when the control unit determines that the engine restrictor has restricted the rotational speed of the engine.
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