3results about How to "Reduce sound intensity" patented technology

The present application relates to internal combustion engine, specifically provide a kind of muffler for aviation internal combustion engine and aviation internal combustion engine, to solve the problem that the exhaust muffler of existing internal combustion engine is too large in size and too heavy in weight, not suitable for the needs of low-altitude aircraft.For this purpose, the muffler of the present application includes air inlet, air outlet and multiple layers of pleated partition, air inlet and air outlet form airflow passage, multiple layers of pleated partition are arranged in airflow passage in spaced-apart, each layer of pleated partition is configured to scatter, reflect, refract and diffract the sound waves of airflow, multiple layers of pleated partition are configured to continuously reflect and refract sound waves in multiple stages, so that sound waves collide with each other to cancel sound energy and reduce sound intensity, so that sound energy concentrated sound waves are scattered and attenuated step by step when passing through multiple layers of pleated partition, so that the muffler of the present application has obvious noise reduction effect, and the muffler of the present application is made of metal 3D printing, so that the effect of small size and light weight can be realized.

The invention relates to the technical field of silencers, in particular to a secondary silencer of a vehicle-mounted air conditioner and a silencing method. The secondary silencer comprises a shell, a shell cover, a connecting pipe, a silencing pipe, a first silencing cavity and a second silencing cavity; the vehicle-mounted air conditioner secondary silencer is installed at the preset position of a vehicle; the secondary silencer of the vehicle-mounted air conditioner is used for silencing the vehicle-mounted air conditioner, under the simultaneous sound absorption and silencing effects of the two silencing cavities, the sound intensity is greatly reduced, finally, the sound is further weakened through the silencing cotton interlayer, the noise is reduced again, the comfort is improved when a long-distance driver has a rest, other people are prevented from being influenced, and the vehicle-mounted air conditioner is safe and reliable. Therefore, the problem that an existing vehicle-mounted air conditioner silencer is low in silencing efficiency is solved.

The utility model provides a kind of metallized polypropylene film capacitor noise reduction device, it is related to capacitor technical field, comprising: capacitor, the one side of capacitor is equipped with two power lines, the upper and lower positions of capacitor are respectively installed one noise reduction board, the outside position of noise reduction board is installed one first cache sponge, the outside position of first cache sponge is installed one protective inner shell, protective inner shell has two, the outside position of protective inner shell is respectively installed one first protective outer shell, one second protective outer shell.Noise reduction board inside face is established honeycomb structure noise reduction groove, can make incoming sound wave constantly reflect and refract, effectively consume sound wave energy, first cache sponge and second cache sponge and noise reduction board mutually cooperate, further enhance the sound insulation effect, so that noise reduction board can more effectively absorb noise, solve the problem that capacitor generates noise and influences surrounding environment.