Automatic beam combining method and device for longitudinal beam

The invention provides an automatic beam combining method and device for a longitudinal beam. The automatic beam combining device comprises a main beam combining unit, and is characterized in that themain beam combining unit comprises a main base, at least two guide bases are mounted above the main base, the guide bases are arranged at intervals in the length direction of the longitudinal beam ofan automobile, each guide base is provided with a main beam combining press, and the main beam presses can be driven by a main driving device to perform front-back reciprocating motion along linear guide rails fixed to the guide bases; a main support frame is mounted beside each main beam combining press on the main base in the length direction of the longitudinal beams, and the top surfaces of all the main support frames form a beam combining platform on one plane; and at least two sets of bolt devices are fixed to the main base, and the positions of the bolt devices can be adjusted in the length direction of the lon