There is provided a work machine that is capable of realizing operability and energy saving ability that are equivalent to those of work machines that have a joint line to be used during swinging/boom raising operation, without incorporating a joint line for supplying a pressurized fluid from a second pump to a bottom-side chamber of a boom cylinder. The controller is configured to compute a hypothetical flow rate representing a flow rate in a hypothetical joint line, compute a first pump provisional target flow rate on the basis of an operation amount of a boom operation device, compute a second pump provisional target flow rate on the basis of an operation amount of a swing operation device, compute a first pump final target flow rate by adding the hypothetical flow rate to the first pump provisional target flow rate, and compute a second pump final target flow rate by subtracting the hypothetical flow rate from the second pump provisional target flow rate.

A hydraulic system for a machine includes a hydraulic circuit, a heater, a temperature sensor, and a controller. The hydraulic circuit is configured to be coupled to an actuator of the machine. The hydraulic circuit includes a reservoir configured to store hydraulic fluid and a pump configured to drive the hydraulic fluid from the reservoir through the hydraulic circuit. The heater is configured to facilitate selectively heating the hydraulic fluid. The temperature sensor is configured to acquire temperature data indicative of a temperature of the hydraulic fluid. The controller is configured to activate the pump to drive the hydraulic fluid through the hydraulic circuit with the heater deactivated to facilitate cooling the hydraulic fluid in response to the temperature of the hydraulic fluid exceeding or approaching a maximum temperature threshold.

A hydraulic system for a machine includes a hydraulic circuit, a heater, a temperature sensor, and a controller. The hydraulic circuit is configured to be coupled to an actuator of the machine. The hydraulic circuit includes a reservoir configured to store hydraulic fluid and a pump configured to drive the hydraulic fluid from the reservoir through the hydraulic circuit. The heater is configured to facilitate selectively heating the hydraulic fluid. The temperature sensor is configured to acquire temperature data indicative of a temperature of the hydraulic fluid. The controller is configured to activate the pump to drive the hydraulic fluid through the hydraulic circuit with the heater deactivated to facilitate cooling the hydraulic fluid in response to the temperature of the hydraulic fluid exceeding or approaching a maximum temperature threshold.

A hydrostatic drive includes at least one hydrostatic pump configured to supply at least one hydrostatic consumer and an apparatus for an energy recovery procedure of at least a part of the energy that is output by the consumer. An electronic control unit or at least one software component is further included, with which the energy recovery procedure is controlled in a variable manner and depends upon detected influencing variables.

[Object] To provide a tactile sense presentation apparatus, an electronic apparatus, an accessory, and a holding apparatus that can achieve an improvement in mountability.

[Solving Means] A tactile sense presentation apparatus according to an embodiment of the present technology includes a mounting portion, a pump unit, and a control unit. The mounting portion is mounted on a target object and includes a surface material which is deformable in at least a part of a contact portion with the target object. The pump unit includes a flow path, which is connected to the mounting portion, and feeds a fluid for deforming the surface material to the mounting portion. The control unit controls driving of the pump unit.

[Object] To provide a tactile sense presentation apparatus, an electronic apparatus, an accessory, and a holding apparatus that can achieve an improvement in mountability.

[Solving Means] A tactile sense presentation apparatus according to an embodiment of the present technology includes a mounting portion, a pump unit, and a control unit. The mounting portion is mounted on a target object and includes a surface material which is deformable in at least a part of a contact portion with the target object. The pump unit includes a flow path, which is connected to the mounting portion, and feeds a fluid for deforming the surface material to the mounting portion. The control unit controls driving of the pump unit.

It is an object of the present invention to provide a construction machine having a good engine starting property in a low temperature environment. The construction machine of the present invention includes: an electric pump having a delivery port connected to a line part of a pilot line, the line part connecting a pilot pump with a pilot control valve; a motor that drives the electric pump; and a temperature sensor that measures a temperature of a hydraulic working fluid delivered from the pilot pump. A controller starts driving of the motor in the case where a key switch is operated from a key OFF state to a key ON state and where the temperature of the hydraulic working fluid measured by the temperature sensor is lower than a predetermined temperature.

A hydraulic circuit includes a pump connected to a tank for supplying hydraulic liquid under pressure to a component via a directional control slide valve provided with a feed port connected to an inlet of the component and with a return port connected to an outlet of the component. The hydraulic circuit further includes a pressure limiter connected to the inlet of the component and the tank, and a feed control system for the hydraulic component including a pressure sensor installed upstream of the hydraulic component downstream of the feed port for supplying information about the pressure of the hydraulic liquid and a setpoint pressure. The feed control system further including an actuator for controlling the movement of the directional control slide valve, and a control unit for generating a control signal for the actuator based on information about the pressure measured at the feed port.

A hydraulic circuit includes a pump connected to a tank for supplying hydraulic liquid under pressure to a component via a directional control slide valve provided with a feed port connected to an inlet of the component and with a return port connected to an outlet of the component. The hydraulic circuit further includes a pressure limiter connected to the inlet of the component and the tank, and a feed control system for the hydraulic component including a pressure sensor installed upstream of the hydraulic component downstream of the feed port for supplying information about the pressure of the hydraulic liquid and a setpoint pressure. The feed control system further including an actuator for controlling the movement of the directional control slide valve, and a control unit for generating a control signal for the actuator based on information about the pressure measured at the feed port.

There is provided a construction machine that is capable of measuring a minute leakage flow rate of a one-sided tilting variable displacement hydraulic pump. The construction machine includes a pressure sensor that detects a pressure of a hydraulic pump, a bleed-off adjusting device that is enabled to adjust a bleed-off flow rate of the hydraulic pump, and an input device that gives an instruction for measurement of a leakage flow rate of the hydraulic pump. The controller is configured to measure, when the controller determines that the operation device is in a non-operated state and when a measuring command is inputted from the input device, a pressure of the hydraulic pump while changing a control command value for the bleed-off adjusting device in a state in which a flow rate of the hydraulic pump is maintained, and calculate the leakage flow rate of the hydraulic pump on the basis of the control command value for the bleed-off adjusting device at the time that the pressure of the hydraulic pump is stabilized at a predetermined pressure.