What Is an Ultrasonic Cutting Machine?
An ultrasonic cutting machine is a device that uses ultrasonic waves to perform cutting and polishing operations. Cutting oil or abrasive slurry is applied between the ultrasonically vibrating tool and the workpiece, causing the surface of the workpiece to undergo brittle fracture and material removal gradually. Ultrasonic processing machines consist of a transducer that vibrates ultrasonically, an oscillator that drives the transducer, and a cutting tool.
Ultrasonic machining is one of the few machining methods that can process three-dimensional shapes of brittle materials, even if the materials are not conductive.
Applications of Ultrasonic Machining Tools
Ultrasonic machines are used to process brittle materials and materials that are difficult to process by general machining. Examples include cutting hard ceramic and metal materials, cutting hard-to-cut carbon fiber, processing quartz glass, and polishing molds.
In addition to hard materials, ultrasonic processing machines are also used for cutting cakes and pie crusts that easily lose their shape, slicing bread, and cutting pizza into pieces, which are commercialized as ultrasonic food cutters. The microscopic ultrasonic vibration reduces frictional resistance between the blade and the food, resulting in a clean-cut surface.
Principle of Ultrasonic Processing Machines
Ultrasonic processing machines apply ultrasonic vibrations to blades to reduce cutting resistance and achieve high processing speed and high precision cutting. There are several ultrasonic machining methods, including cutter and grinding, but the principles of typical methods are explained here.
In spindle machining, ultrasonic vibration is applied to the machining jig, and the jig is rotated for machining. In abrasive grain processing, abrasive grains are poured into the ultrasonically vibrating processing jig, and then ground and processed in small quantities.
The following is a brief description of the oscillator and transducer that make up the ultrasonic processing machine. The oscillator converts electric power into ultrasonic vibration. Since the operating frequency of the transducer varies with the blade and grinding wheel, it is equipped with an electronic circuit to adjust it to the optimum frequency.
The transducer consists of a bolted Langevin-type transducer (commonly called BL transducer) that generates ultrasonic vibration, a fixed horn that increases the amplitude, and a blade that transmits the vibration. There are several types of blades depending on the application, and they are used according to the situation.