Vacuum clamp for machining circular arc of salt core

Abstract

The invention belongs to the technical field of a manufacturing industry and specifically relates to a vacuum clamp for machining a circular arc of a salt core; the vacuum clamp comprises an upper mold and a lower mould integrally connected from top to bottom; a plurality of workpiece positioning ring-shaped slots are arranged at the upper part of an upper die, and an vacuum evacuation mold cavity is arranged at the lower part of the upper die; a plurality of small holes mutually communicated with the vacuum evacuation mold cavity are evenly distributed on the workpiece positioning ring-shaped slots; the mold cavity is connected with a pipe of a vacuum pump unit; a lower mold is of a solid. The vacuum clamp is used for clamping a fragile workpiece (the salt core), the workpiece is clamped and released in a vacuum evacuation mode, a vacuum evacuation clamp can reduce stress of the workpiece in clamping and machining processes, so that the workpiece is not easily to be broken in the clamping and machining processes, thereby ensuring a size requirement of the circular arc; the clamp is simple in structure, easy to manufacture, convenient to operate in a clamping operation; by using the vacuum clamp to machine workpieces, most polishing allowance is reduced, production efficiency is high, machining quality is ensured in a certain degree, labor intensity is reduced, production cost is reduced, so that the vacuum clamp is worthy to be popularized and can machine salt cores in various special shapes.

Description

technical field [0001] The invention relates to a vacuum fixture for processing arcs of salt cores, which belongs to the technical field of manufacturing industry. Background technique [0002] At present, most of the internal cooling passage pistons at home and abroad use salt-core aluminum pistons, that is, the pistons whose internal cooling oil passages are formed with salt cores during the casting process of aluminum pistons, which have become an inevitable choice for high-speed and high-power engines. Salt cores are formed by pressing molds, and then made by turning arcs, trimming the appearance (grinding with fine sandpaper), sintering, and drilling. The raw material is sodium chloride (medical salt), but the salt cores are poor in brittleness. It is easy to break under force and easy to be affected by moisture. The tensile strength of the salt core after sintering is required to be greater than or equal to 50N. [0003] As the production of salt cores is increasing ...

AI Technical Summary

Problems solved by technology

The disadvantage is that the clamping force is too large (the force is not easy to control, the hand control) the salt core is easy to break, the tensile strength is low, and the fracture rate of this process is high; and for the salt core with a boss (or platform) (such as Shanghai KS’s LDK salt core) or oval salt core cannot be clamped and turned on a lathe. At present, after scraping off a part of the margin with a blade by hand, it is then polished into an arc with 120-grit sandpaper to make the arc connection smooth. The grinding allowance is large, the process is labor-intensive, low in efficiency, and the arc size is difficult to guarantee

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