The utility model relates to a make the automobile body be difficult for producing the inflation -free tire who jolts and feel, include the matrix, the matrix includes roof and the lateral wall of setting in the roof both sides, and the bottom of lateral wall is provided with the tire bead, and roof, lateral wall and the tire bead of matrix surround and form the working chamber, are provided with a plurality of baffles in the working chamber, and the both sides of baffle are fixed and are set up on the lateral wall of matrix, and the top of baffle is equipped with follows the notch that separates the plate thickness orientation and run through the baffle to the upper surface of baffle and the lower surface contactless of roof.