This construction machine comprises: includes a work machine; an automatic controller for automatically controlling the work machine according to design information; an operation lever for manually controlling the work machine; and an automatic switch mounted on the operation lever and alternatively switching between activation and deactivation of the automatic control. The manual control of the work machine has higher priority than the automatic control.

An excavator includes a lower traveling body; an upper turning body turnably mounted to the lower traveling body; an attachment that is attached to the upper turning body; a bucket constituting the attachment; and a control device configured to calculate a weight of an object that is moved from inside the bucket onto a loading platform of a transport vehicle, based on output of a space recognition device, configured to recognize a space surrounding the upper turning body, and the weight of the object in the bucket.

A hydraulic apparatus has a plurality of pump modules each of which is formed by a plurality of working chambers having a common high pressure manifold. A connecting circuit switchably connects pump modules to first and second hydraulic circuit portions to allocate capacity as first and second demands for hydraulic fluid vary. In an apparatus which may have two or more connecting circuit outputs, valves may be controlled or working chamber pumping cycles made inactive to facilitate the reallocation of a pump module from one output to another, and a control strategy addresses pump module allocation when the demands for hydraulic fluid exceed available capacity.

When a first control valve and a second control valve are in non-neutral positions, respectively, a fifth fluid passage and a second fluid passage are closed, thereby generating a first pressure within a fifth portion of the fifth fluid passage and a second pressure within a second portion of the second fluid passage, so that the first pressure is applied to a first valve through a fourth fluid passage to move the first valve to close the third fluid passage and a second pressure is applied to the confluence valve through a first fluid passage to move the confluence valve to a confluence position. When the confluence valve is in the confluence position, the confluence valve directs working fluid from a first working fluid supply to the second control valve.

A construction assist system that assists construction with a shovel includes a hardware processor configured to simulate the motion of the shovel in a virtual environment that is set based on the work environment of the shovel.

A hydraulic system for a working machine includes a hydraulic pump to output a hydraulic fluid, an operation device operable to supply a pilot fluid in accordance with an amount by which the operation device is operated, a hydraulic actuator to be operated by the hydraulic fluid, a pilot fluid passage connected to the operation device, a first control valve connected to the pilot fluid passage and to be operated by the pilot fluid to control a flow of the hydraulic fluid, a second control valve to be operated by the pilot fluid to control a flow of the hydraulic fluid, a proportional valve to change a pressure of the pilot fluid to operate the second control valve, a pressure detector provided in the pilot fluid passage to detect a pressure in the pilot fluid passage, and a controller to control the proportional valve based on the pressure.

Problem to be solved: To provide a hydraulic circuit for the construction machine which enables to use the relief valve of low capacity in the work tool circuit. Solution: The hydraulic circuit 2 for a construction machine has: a hydraulic pump 4 of variable capacity, a work tool 6 operated by hydraulic oil delivered by the hydraulic pump 4, a work tool operating device 10 to output a signal for operating the work tool 6, a control valve 14 allowing the hydraulic pump 4 to supply the hydraulic oil to the work tool 6 based on the signal output from the work tool operating device 10, a tool's relief valve 44 to release the hydraulic oil flowing between the control valve 14 and the work tool 6, a pressure sensor 46 to detect a pressure of hydraulic oil flowing into the work tool 6, and a controller 48 to reduce a delivery rate from the hydraulic pump 4 when the pressure detected by the pressure sensor 46 exceeds a predetermined value.

Disclosed are power systems, and power machines employing the power systems, having dual in-line pumps configured to supply hydraulic fluid to respective left and right side travel motors of the power machine. In some exemplary embodiments, pump pintle arm controls and a single centering mechanism for the pintle arm controls are provided. The single centering mechanism is configured to center the pintle arms for each of the two pumps. Also in some exemplary embodiments, a mechanical control linkage configuration allows the separate pump pintle arm controls to be positioned on a side of the pump substantially one behind the other. This allows hydraulic connections to the pumps to be placed on top of the pump assembly, improving the routing of hydraulic hoses in the power machine.

A hydraulic system for a working machine includes a first electric machine connected to a first hydraulic machine; a second electric machine connected to a second hydraulic machine, an output side of the second hydraulic machine being connected to an input side of the first hydraulic machine; at least one hydraulic consumer hydraulically coupled to an output side of the first hydraulic machine via a supply line and configured to be powered by the first hydraulic machine; and a valve arrangement arranged between the hydraulic consumer and the first and second hydraulic machines, wherein the valve arrangement is configured to control a return flow of hydraulic fluid from the hydraulic consumer to either the input side of the first hydraulic machine or an input side of the second hydraulic machine based on a requested output pressure from the first hydraulic machine.

A fluid supply system supplying multiple fluid consumers of a vehicle with fluid, the fluid supply system including: a first pump supplying a first fluid consumer, arranged in a first supply circulation of the vehicle, with fluid; a second pump supplying a second fluid consumer, arranged in a second supply circulation of the vehicle, with fluid; and a directional control valve adjustable between a first valve position and at least one other, second valve position and preferably includes an electromagnetic device for adjusting. The directional control valve allows the fluid to be delivered from the second pump into the first supply circulation in the first valve position and separates the first supply circulation from the second pump, or allows the fluid to be delivered from the second pump into the first supply circulation only to a restricted extent as compared to the first valve position, in the second valve position.