BRAKING APPARATUS FOR ELECTRIC WINCH

摘要

Provided is a braking apparatus for braking of an electric winch of a construction machine, ensuring safe braking with much regeneration. The apparatus includes a regenerative-power generation unit, a regenerative-power receiving unit, a braking device for mechanical braking separately from the regenerative-power generation unit, and a braking control unit including a necessary-braking-capacity calculation section, a regeneration-capacity calculation section calculating a regeneration capacity, and a command section. The command section, when the regeneration capacity is not less than a necessary braking capacity, performs braking with only a regenerative action while not operating the braking device and, when the regeneration capacity is less than the necessary braking capacity, calculates an auxiliary braking force equivalent to a difference between the necessary braking capacity and the regeneration capacity and brings the braking device into braking action with the auxiliary braking force.

主权项

1. An apparatus for braking an electric winch provided in a construction machine and driven to move a load, the apparatus comprising:
a regenerative-power generation unit that performs a regenerative action of generating regenerative power while applying a braking force to the electric winch; a regenerative-power receiving unit that receives the regenerative power generated by the regenerative-power generation unit; a braking device that applies a mechanical braking force to the electric winch separately from the braking force applied to the electric winch from the regenerative-power generation unit, the mechanical braking force being adjustable; and a braking control unit that provides commands to the regenerative-power generation unit and the braking device to thereby control braking of the electric winch, wherein: the braking control unit includes a necessary-braking-capacity calculation section that calculates, on the basis of an operation state of the electric winch, a braking capacity necessary for achieving a required braking action on the electric winch, a regeneration-capacity calculation section that calculates a regeneration capacity that is a limit of a regenerative action performed by the regenerative-power generation unit and the regenerative-power receiving unit, and a command section that commands the regenerative-power generation unit and the braking device on the basis of the regeneration capacity calculated by the regeneration-capacity calculation section and the necessary braking capacity calculated by the necessary-braking-capacity calculation section; the command section, when the regeneration capacity is equal to or greater than the necessary braking capacity, commands the regenerative-power generation unit to perform the braking of the electric winch with only a regenerative action by the regenerative-power generation unit while not operating the braking device; and the command section, when the regeneration capacity is less than the necessary braking capacity, commands the regenerative-power generation unit to perform the regenerative action within a range of the regeneration capacity, calculates an auxiliary braking force equivalent to a difference between the necessary braking capacity and the regeneration capacity, and commands the braking device to perform the braking of the electric winch with the auxiliary braking force.