Electric Head Restraint Gearbox

In common traffic accidents, such as rear-end collisions, passengers are vulnerable to neck injuries. Active head restraints are becoming more and more popular. ZHAOWEI gearbox for active head restraint (AHR) can improve the effectiveness of active head restraints.

The design of modern car attaches big importance to safety. Rear-end collisions account for a large proportion of traffic accidents. Most rear-end collisions cause neck injuries. Neck injuries in a low-speed rear-end collision may cause cervical spine injuries and long-term neck pain. Improving the anti-whipping performance of seat headrests has practical economic and social significance.

Active head restraint (AHR) is a mechanical system. The upper cushion support is a pressure plate connected to the seatback through a connecting rod. When the car was rear-ended, the passenger’s body was impacted. The impact force will hit the backrest and push the pressure plate back. The headrest will be pushed forward to push the passenger’s head and neck, preventing or reducing the possibility of injury before the head and neck swing. The collision activation device is placed inside the headrest. When activated, the device moves the entire headrest upward through the metal support column to protect the head and neck of the passenger.

Drive System for Active Headrest

The headrest mechanism includes a control module, a drive motor, and a connecting drive mechanism. The control system and the drive motor interact through signals. The connecting drive mechanism includes an upper cross link mechanism arranged in parallel, a lower crosslink mechanism, and a drive screw connected to the motor. When a dangerous situation occurs, the control module uses a single-chip microcomputer or on-board computer to control the forward rotation of the motor. When the two nuts move toward each other, the head restraint is unfolded through the connecting drive mechanism. When the dangerous conditions are eliminated, the control motor will reverse. The two nuts move backward, and the cushion mechanism folds the headrest. The drive motor/gearbox must meet specific requirements: it should have the characteristics of low noise, reliability, quick start, and strong vibration resistance, which are the requirements that ZHAOWEI gearbox can meet.

The AHR gearbox mentioned above is only shown as a case that is developed for specific customers. It can be also customized according to customer requirements.