Automatic operation for vehicle tailgate door - has hydraulic system with controlled servo motor drive, sensitive to obstructions in door gap

摘要

The tailgate is moved about its horizontal axis by a servo ram (2) coupled to a drive cylinder (3) driven by an electric servo motor (35). The servo ram piston (22) has a non-return valve, closed in the power stroke, and a flow restriction (4). The latter provides for a controlled closing of the flap when the drive cylinder is reversed. The movement of the drive motor is controlled by a speed sensor (9) which determines the end of movement of the door action. A gas spring (G) integral to the servo ram provides a cushioning effect. Obstruction jammed into the door are sensed by the change in speed of the drive motor and a reversal drive is initiated to release the obstruction. ADVANTAGE - Compact servo drive, failsafe.