Construction Machine

A construction machine comprising:

• a track structure;
• a swing structure disposed swingably on the track structure;
• a work implement including a boom, an arm, and a bucket, the boom being coupled vertically swingably to the swing structure;
• a first hydraulic pump and a second hydraulic pump that are driven by a prime mover;
• a boom cylinder driven by hydraulic fluid from the second hydraulic pump to thereby drive the boom;
• a swing hydraulic motor driven by hydraulic fluid from the first hydraulic pump to thereby drive the swing structure;
• a swing electric motor connected mechanically with the swing hydraulic motor;
• an inverter that controls operation of the swing electric motor;
• a controller that calculates a torque command value for controlling electric driving torque and electricity generating torque of the swing electric motor and outputs the torque command value to the inverter;
• a first operation lever device that directs operation of the swing structure;
• and
• a second operation lever device that directs operation of the boom, wherein
• the controller includes a torque command value calculation section that receives inputs of a swing operation amount signal of the first operation lever device and a boom raising operation amount signal of the second operation lever device and that outputs a torque command value of the electricity generating torque of the swing electric motor to the inverter when load pressure of the swing hydraulic motor is determined to be higher than load pressure of the boom cylinder.