Kubota Corporation

Kurimoto, Ltd.

Kyb Corporation

Hiroshi Horii

Hiroya Mori

Katsunobu Miyake

Kenji Ikoma

Atsushi Matsumoto

Keisuke Miura

Hirotaka Kobayashi

Masaaki Ueda

Tetsuya Aoki

Teruo Kunizawa

Shoichi Kawano

Toshiaki Otani

Hisayuki Hiramatsu

Hitoshi Iwamura

Kazuaki Shobu

Kunihiko Bito

Shohei Doi

Ryohei Masuda

A hydraulic system of a working machine includes: a hydraulic actuator; a direction switching valve; the solenoid proportional valve; a controller to control a current to be supplied to the solenoid proportional valve; an operation member for a worker to operate the hydraulic actuator; and a permission operation actuator capable of performing a switching operation between a permission operation for permitting driving of the hydraulic actuator and a non-permission operation for not permitting the driving, in which, when the permission operation actuator is subjected to the non-permission operation and a temperature of the hydraulic fluid is lower than a predetermined temperature, the controller supplies, to the solenoid proportional valve, a first standby current of a first current value defined in a range in which a switching position of the direction switching valve is not switched.

Hydraulic system of working machine and working machine

A working machine includes: a plurality of hydraulic actuators including a high-load hydraulic actuator and a low-load hydraulic actuator whose hydraulic pressure for actuation thereof is lower than that of the high-load hydraulic actuator; a plurality of direction switching valves each of which switches a direction of a hydraulic fluid for a corresponding one of the hydraulic actuators, the plurality of direction switching valves including a low-load direction switching valve that switches a direction of hydraulic fluid for the low-load hydraulic actuator; and a dummy-load forming unit that forms a dummy load in the low-load direction switching valve to suppress a variation in an actuation speed of the low-load hydraulic actuator between a time when the high-load hydraulic actuator and the low-load hydraulic actuator are operated in combination and a time when the low-load hydraulic actuator is operated singly.

Working machine

A working machine includes a machine body, a first hydraulic actuator mounted on the machine body, a first control valve that controls the first hydraulic actuator, a controller that controls the first control valve, and a second hydraulic actuator that is different from the first hydraulic actuator. When the second hydraulic actuator and the first hydraulic actuator are operated in combination, the controller reduces the amount of change in the flow rate of a hydraulic fluid supplied from the first control valve to the first hydraulic actuator with respect to changes in a manipulation amount to operate the first hydraulic actuator to a value smaller than that when the first hydraulic actuator is solely operated.

A working machine, in which a detection device for detecting a swing position of a supported member is prevented from being damaged, includes a support member pivotally supporting the supported member via a pivot, and a cylinder telescopically moved by extension and contraction movement of its piston rod with respect to its cylinder tube by hydraulic fluid flowing through a fluid passage formed in the piston rod. The cylinder tube is pivotally supported by a first end portion of the support member, and the piston rod is pivotally supported by a second end portion of the support member. The detection device for detecting a telescopic movement state of the cylinder is provided between the cylinder and the support member.

A hydraulic system of a working machine includes a hydraulic actuator to be driven with a hydraulic fluid; a solenoid proportional valve to control the hydraulic actuator in accordance with a current that is supplied; and a controller to control the current that is supplied to the solenoid proportional valve. The controller changes a dither amplitude of the current that is supplied to the solenoid proportional valve in accordance with a temperature of the hydraulic fluid.

Hydraulic system of working machine

A working machine includes: an operator's seat; and at least one pedal to be operated by being stepped on with a foot, or with feet. The at least one pedal is disposed ahead of the operator's seat. The at least one pedal includes a pedal body extending in a predetermined direction, a pedal shaft having an axis intersecting the predetermined direction and supporting the pedal body in such a way as to allow pivotal motion of the pedal body around the axis, and a tread surface provided on an upper surface of the pedal body and being a surface on which an operator places the foot. The tread surface is sloped such that a height from the pedal body decreases gradually from a portion closer to a big toe of the foot of the operator placed thereon toward a portion closer to a little toe.

In a hydraulic system of a working device, a controller includes a first calculator that calculates a first electric current value for decelerating an angular velocity of a movable member, a second calculator that calculates a second electric current value for decreasing a supply flow rate of a hydraulic fluid to a hydraulic cylinder, and an electric current restrictor that corrects an electric current supplied to an electromagnetic proportional valve by the second electric current value if a determination distance of an operation length from a current operation position of the hydraulic cylinder to a stroke end is longer than a first threshold value and is not more than a second threshold value and corrects the electric current supplied to the electromagnetic proportional valve by either the selected first or second electric current value if the determination distance is not more than the first threshold value.

Hydraulic system of working machine and method for controlling hydraulic system of working machine

To ease work of transferring a fuel from a fuel supply tank to a fuel tank, a fuel supply guide to be used to supply the fuel by using the fuel supply tank to the fuel tank having a tank body for storing the fuel and a fuel supply port on the upper side of the tank body includes a support member provided on an upper portion of the fuel tank, and a body member projecting from the support member in a direction away from the fuel supply port as the body member extends upward and projecting higher than the fuel supply port. The body member is capable of receiving the fuel supply tank by an upper portion thereof to support the fuel supply tank.

Fuel supply guide and working machine

A manipulator mechanism includes a rotary shaft rotatable about an axis extending in a first horizontal direction, an operation member disposed at one of opposite ends of the rotary shaft in an axial direction thereof to rotate together with the rotary shaft, an angle sensor disposed at the other of the opposite ends of the rotary shaft in the axial direction to detect a rotation angle of the rotary shaft, and a neutral return mechanism provided between the operation member and the angle sensor to return the operation member to a neutral position from a post-operation position which is a position to which the operation member has been moved.

Manipulator mechanism and working machine

A working machine includes a cooling fan, and a first cooling device and a second cooling device that are disposed in series in a flow passage of cooling air that is generated by the cooling fan. The first cooling device is disposed upstream of the second cooling device in a direction of flow of the cooling air, and has a heat-exchange suppressing portion that is provided at a portion corresponding to a region in a rotation center vicinity of the cooling fan and that suppresses heat exchange between the cooling air and a fluid that flows in the first cooling device.

Working vehicle

A neutral return mechanism includes an interlocking shaft to be pushed and pulled in an axial direction in conjunction with a swinging operation of an operation member; a housing member to support the interlocking shaft such that the interlocking shaft is movable in the axial direction and accommodate the interlocking shaft such that one of opposite end portions thereof protrudes; a neutral return spring to return the interlocking shaft from a post-movement position to an initial position, the neutral return spring being accommodated in the housing member such that the neutral return spring extends in the axial direction of the interlocking shaft, wherein the housing member includes a supported portion between a spring accommodation portion in which the neutral return spring is accommodated and a protrusion opening through which the interlocking shaft protrudes, the supported portion being supported at a bracket member.

Neutral return mechanism

In a working machine, a stroke of an arm cylinder caused when a distance of a tip portion of an arm from a machine body is equal to a predetermined limit distance is defined as a stroke Y, a stroke of a boom cylinder caused when the stroke of the arm cylinder is equal to the stroke Yand a height of the tip portion of the arm is equal to a height of a boom pivot shaft is defined as a stroke X, and when the stroke of the boom cylinder is between Xand a stroke end thereof in a direction to swing the boom upward, the controller restricts the stroke of the arm cylinder to swing the arm in a dumping direction to prevent the arm from swinging further in the dumping direction from a position where the stroke of the arm cylinder is equal to Y

A working machine includes a controller device to set an allowable-stroke range of the arm cylinder moving the arm toward the boom depending on a turn position of the boom such that a shortest trajectory distance that is a shortest distance between the boom cylinder and a turn trajectory of the tip end portion of the bucket is kept at a predetermined value even when the turn position of the boom changes, in a case where the boom is turned in a direction separating from a boom reference position.

Working machine and control method of working machine

A working machine includes a machine body, a support bracket protruding forward from the machine body, a swing bracket pivotally supported by the support bracket to be capable of horizontally pivoting, a boom pivotally supported by the swing bracket to be capable of pivoting up and down, a swing sensor configured to detect a position of the swing bracket, and a controller configured to acquire a detection signal from the swing sensor and to control a swinging movement defined as a pivotal movement of the swing bracket. The controller includes a swinging stopper unit to stop the swinging movement when the swing bracket in the pivotal movement reaches a center position at which the boom is orientated in a forward direction of the machine body.

A working machine includes a traveling device having a traveling frame, a turn base plate supported on the traveling frame and configured to turn around an axis extending in a vertical direction, the turn base plate having an opening portion through which the axis extends, and a swivel joint including an outer sleeve fixed to the turn base plate, and an inner shaft inserted to the opening portion and inserted to the outer sleeve so as to rotate about the axis, the inner shaft being configured to restrictively rotate with respect to the traveling frame. The outer sleeve has a flange portion fixed to the turn base plate on a periphery of the opening portion and covering the opening portion.

Growing community of inventors

Sakai, Japan

Hiroshi Horii