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公开(公告)号：US20200232180A1
公开(公告)日：2020-07-23
申请号：US16641712
申请日：2019-01-31
摘要： 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：US20210332560A1
公开(公告)日：2021-10-28
申请号：US16328345
申请日：2017-09-29
摘要： 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：US20210131069A1
公开(公告)日：2021-05-06
申请号：US16492482
申请日：2018-05-23
发明人： Kiwamu TAKAHASHI , Taihei MAEHARA , Takeshi ISHII , Yoshifumi TAKEBAYASHI , Natsuki NAKAMURA , Daisuke OKA
摘要： 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：US20190292753A1
公开(公告)日：2019-09-26
申请号：US16277533
申请日：2019-02-15
摘要： A construction machine that can easily regulate a set maximum flow rate at a time of replacement of an attachment and that can improve an energy conservation performance is provided. A controller selects a corresponding map in response to an attachment designation signal from among maps each of which sets a relationship between an operation signal per type of the attachment and a flow rate of a hydraulic fluid supplied to an actuator, generates a control signal by causing the selected map to refer to the operation signal, and controls a flow control valve of an attachment flow rate regulation valve device in such a manner that a position of the flow control valve is switched over from a neutral position on the basis of the control signal. An unloading valve that maintains a differential pressure across the flow control valve is disposed in the attachment flow rate regulation valve device.
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公开(公告)号：US20200340206A1
公开(公告)日：2020-10-29
申请号：US16082447
申请日：2017-03-24
摘要： A hydraulic drive system for a hydraulic excavator that enables leveling work and a jack-up operation by a blade in a float state, that can prevent a body from falling even when an operator has falsely operated the hydraulic excavator during the jack-up operation by the blade, and that yet can perform favorable leveling work with the blade turned into the float state is provided. A float switch 37, a float valve 38, and a controller 34 are provided, the float valve 38 is changed over to a float position VI upon operating the float switch 37 when the blade is not in a jack-up state, the float valve 38 is changed over from the float position VI to a normal position V when the float valve 38 is in a state of being at the float position VI and an operation lever device 22 has been operated, and the float valve 38 is kept at the normal position V when the float valve 38 is at the normal position V and the float switch 37 has been operated in the jack-up state.
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公开(公告)号：US20190177953A1
公开(公告)日：2019-06-13
申请号：US16326754
申请日：2017-12-14
摘要： 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：US20200165794A1
公开(公告)日：2020-05-28
申请号：US16080387
申请日：2017-02-22
摘要： 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：US20180156242A1
公开(公告)日：2018-06-07
申请号：US15883357
申请日：2018-01-30
CPC分类号： F15B9/08 , E02F3/325 , E02F9/2203 , E02F9/2225 , E02F9/2285 , E02F9/2296 , F15B9/03 , F15B11/166 , F15B13/06 , F15B2211/20553 , F15B2211/30535 , F15B2211/329 , F15B2211/355 , F15B2211/6051 , F15B2211/6055 , F15B2211/6058 , F15B2211/6355 , F15B2211/7058 , F15B2211/7135 , F15B2211/781
摘要： 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：US20170067226A1
公开(公告)日：2017-03-09
申请号：US15122789
申请日：2015-06-10
发明人： Kiwamu TAKAHASHI , Kazushige MORI , Masamichi ITO , Yoshifumi TAKEBAYASHI , Natsuki NAKAMURA , Yasuharu OKAZAKI , Kenji YAMADA
CPC分类号： E02F9/2062 , E02F3/325 , E02F3/964 , E02F9/2225 , E02F9/2228 , E02F9/2232 , E02F9/2235 , E02F9/2285 , E02F9/2296 , F15B11/162 , F15B11/163 , F15B11/165 , F15B13/024 , F15B13/06 , F15B2211/20507 , F15B2211/20546 , F15B2211/20553 , F15B2211/30535 , F15B2211/40576 , F15B2211/50518 , F15B2211/513 , F15B2211/5151 , F15B2211/55 , F15B2211/6051 , F15B2211/6055 , F15B2211/7135
摘要： In a hydraulic driving system for construction machines, when track motors 3f and 3g are operated and the delivery pressure of a main pump 2 increases to a second value PS2 of the set pressure of a main relief valve 14, the set pressure of a signal pressure relief valve 16 increases from a third value PA1 to a fourth value PA2, which is smaller than the second value PS2 of the set pressure of the main relief valve 14, the difference between the second value PS2 and the fourth value PA2 being smaller than the target LS differential pressure. With such a structure, even if one of actuators reaches the stroke end and the delivery pressure of the hydraulic pump rises to the set pressure of the main relief valve, the other actuators do not stop, and further when the main relief valve is configured to increase the set pressure during operation of a specific actuator, the load pressure of the specific actuator does not increase to the increased set pressure of the main relief valve.
摘要翻译： 在用于施工机械的液压驱动系统中，当履带马达3f和3g被操作并且主泵2的输送压力增加到主溢流阀14的设定压力的第二值PS2时，信号压力的设定压力 安全阀16从第三值PA1增加到小于主溢流阀14的设定压力的第二值PS2的第四值PA2，第二值PS2和第四值PA2之间的差小于 目标LS差压。 通过这样的结构，即使一个致动器到达行程端，液压泵的输送压力上升到主安全阀的设定压力，其他的执行器也不会停止，而当主安全阀配置为 增加特定执行机构运行时的设定压力，特定执行器的负载压力不会增加到主溢流阀的设定压力增加。
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