3results about How to "Dense metallographic structure" patented technology

The utility model discloses an air valve structure and engine, the air valve structure comprises a disk part and a rod part, the disk part comprises a first section, a second section and a third section which are connected in sequence, the second section is used for being matched with an air valve seat ring in a sealing mode, and the third section is connected with the rod part. The surface roughness of the first section of peripheral side surface and the surface roughness of the third section of peripheral side surface are both larger than the surface roughness of the second section of peripheral side surface. The air valve structure is particularly suitable for a hydrogen engine, the sealing effect between the second section and the air valve seat ring can be guaranteed, and the problems of air inlet channel backfire and exhaust channel after-combustion are solved; through the design of the first section and the third section, the processing difficulty is reduced, the heat transfer effect is improved, and the risk of hydrogen preignition is reduced; and due to increase of the surface roughness, hydrogen is not prone to entering metal, the probability of hydrogen brittleness fracture of the valve structure is reduced, and the service life of an engine is guaranteed.

The utility model discloses an aluminum alloy cardba hub, including the rim and the spoke, the spoke is connected on the rim one end top, be equipped with a plurality of air holes on the spoke, and the one end of spoke is the mounting surface, and the center of mounting surface is the center's positioning hole, and be equipped with a plurality of mounting holes on the mounting surface, the recess of spoke and rim junction is provided with the air valve hole, and the air valve hole and air hole are staggered. Compared with the prior art, the air valve hole of the utility model is located in the recess of the junction of the spoke and the rim, and the air valve hole and the air hole are staggered, which is beneficial to stress dispersion, avoids the common crack caused by the overlapping of the air valve hole and the air hole position, and improves the safety performance of the aluminum alloy cardba hub.

The invention discloses a precision roll forging-die forging composite forming process for a movable arm of engineering machinery, which comprises the following steps of: carrying out two-pass roll forging on a heated metal blank to obtain an intermediate blank with a required shape, bending and die forging to obtain a formed product, and directly entering the bending and die forging forming procedures of the intermediate blank without secondary heating; a workpiece extends in the axis direction of the workpiece through two-pass roll forging machining, the surface of the workpiece is extruded through a profiled groove in a two-pass roll forging die, and the workpiece is rolled into the needed section shape and size. According to the method, the heated metal blank with the circular cross section is subjected to two-pass roll forging to be manufactured into the blank for the subsequent forming procedure, the intermediate blank with the good shape, size and surface quality is obtained, the quality of the movable arm forge piece is effectively improved, and the defects that the forge piece is folded and cannot be fully filled due to the shape problem of the manufactured blank are overcome; and continuous local deformation is achieved in the roll forging process, so that the metal flow direction is consistent with the shape of the intermediate blank, the metallographic structure is uniform and compact, and forgings with good mechanical performance can be obtained easily.