The invention relates to the technical field of body-in-white
welding fixtures, and in particular to a pneumatic
logic control air circuit for a
welding fixture and a
welding fixture, wherein the control air circuit comprises: a multi-stage
reversing valve group, each comprising a plurality of clamping reversing valves; the control air circuit comprises a release and clamping control air circuit; the clamping control air circuit comprises a
sequence control air circuit and a plurality of clamping control branches, the clamping control
branch comprises an AND valve and a
vehicle type selection air circuit, the
vehicle type selection air circuit comprises a plurality of
vehicle type control air ports, and the vehicle type control air ports of different vehicle types cooperate with the
sequence control air circuit to realize control of different clamping sequences of different vehicle types, and when it is necessary to increase control of other vehicle types, it is only necessary to increase the vehicle type control air port in the vehicle
type selection air circuit; when it is necessary to increase the number of clamping reversing valves in the
reversing valve group, it is only necessary to increase the clamping control
branch, as well as increase the output ports of the
sequence control air circuit and the release control air circuit, so as to solve the problem that the existing pneumatic
control logic design is complicated and difficult to edit and modify.