Swivel drive controller and construction machine including the same

Abstract

The invention provides a swivel drive controller and a construction machine including the same. A swivel drive controller for controlling drive of a swivel mechanism on a construction machine which is swivel-driven by an electric motor includes a velocity command output section to output a velocity command for controlling rotation speed of the electric motor in accordance with the amount of operational input from an operational section on the construction machine, a torque direction detection section to detect a direction of the torque applied to a rotary shaft of the swivel mechanism, and a drive control section which generates a drive command for controlling the electric motor to control drive of the electric motor in accordance with the velocity command output from the velocity command output section. In case a swivel direction indicated by the velocity command output from the velocity command output section and a torque direction detected by the torque direction detection section are opposite to each other, the drive control section starts drive of the electric motor using the drive command in starting swivel of the swivel mechanism.

Description

technical field [0001] The present invention relates to a turning drive control device for driving control of a turning mechanism of a construction machine, and a construction machine including the turning drive control device. Background technique [0002] Conventionally, a construction machine including an electric motor as a power source of a turning mechanism for turning an upper turning body has been proposed. In such a construction machine, when the swing mechanism is accelerated (driven) by the electric power of the motor and decelerated (braked), the swing mechanism is regeneratively operated to charge the battery with generated electric power (for example, Patent Document 1). In addition, the construction machine described in this patent document 1 is provided with a hydraulic pump in order to hydraulically drive the driving mechanism other than the slewing mechanism, which connects the generator to the engine for driving the hydraulic pump through the speed increas...

AI Technical Summary

Problems solved by technology

[0005] In this way, when turning again in a state where vibration is generated, if the swing direction starts in the same direction as the swing direction, the boom, arm, and bucket will repeatedly swing in a direction that is backward relative to the swing direction, thereby vibrating It is amplified (or new vibration is generated), so there is a problem that sometimes the turning cannot be started smoothly and the riding feeling is deteriorated

[0006] In addition, the increase in vibration may become more pronounced when the bucket is loaded with soil, sand, etc., or when a lifting magnet that is heavier than the bucket is installed

[0007] In addition, when the rotation cannot be started smoothly in this way, there may be a shock caused by the backlash of the gears of the rotation mechanism.

[0008] If there is knocking between the teeth due to such backlash, a large impact is transmitted to the upper swing body, and there is a problem that the swing drive cannot be started smoothly and the ride quality is deteriorated.

In addition, there is a problem of damaging the gears of the slewing mechanism if the knocking between the teeth of the backlash continues.

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