Two-stroke four-cylinder piston engine muffler for medium and small unmanned aerial vehicles

Abstract

The invention discloses a two-stroke four-cylinder piston engine muffler for medium and small unmanned aerial vehicles, belonging to the field of unmanned aerial vehicle engines. The two-stroke four-cylinder piston engine muffler for the medium and small unmanned aerial vehicles includes a left muffler sub-component and a right muffler sub-component which are symmetrically arranged; the left muffler sub-component includes a flange assembly, an intake pipe and a muffler assembly; the muffler assembly includes an expansion chamber, an inner inserting tube, a front end cover, a front partition, arear partition and a rear end cover; the side walls of the inner inserting tube are provided with a number of second through holes along the circumferential direction, which are combined with the twocavities separated by the rear partition to form a double resonance cavity muffler; and the upper end of the side wall of the expansion chamber is provided with two through holes along the axial direction, which are connected to the two cylinders on the left side of the engine longitudinal axis through the intake pipe and the flange assembly. The invention designs an impedance composite muffler,which combines two types of structure mufflers of blocking and resistance, so that the muffler has the characteristics of a blocking muffler to eliminate medium and high frequency noise and a resistive muffler to eliminate low and medium frequency noise. Test data shows that the maximum insertion loss of the muffler can reach 14.48dB.

Description

technical field [0001] The invention belongs to the field of drone engines, and in particular relates to a muffler for a two-stroke four-cylinder piston engine used for small and medium-sized drones. Background technique [0002] With the application of various types of drones in various industries, their role in social life and daily life is becoming more and more significant, especially in military, exploration, monitoring, inspection and other fields. The application of this technology can effectively improve Improve work efficiency and work quality, reduce operating costs. [0003] The type and quantity of small and medium-sized UAVs powered by small aviation piston engines occupy a dominant position in the UAV equipment of various countries in the world. For a small aviation piston engine, it is itself a complex power machine with multiple sound sources. At present, the domestic small aviation piston engine is mainly realized through infrared stealth technology and son...

AI Technical Summary

Problems solved by technology

[0006] The above-mentioned first patent is a horizontally opposed four-cylinder two-stroke gasoline aeroengine, and its exhaust pipe is four simple and independently connected exhaust elbows, which do not have the function of noise reduction and noise reduction; the second patent describes The applicability of the muffler has the following disadvantages: first, it is essentially a resistant muffler, and the frequency band of noise that can be eliminated is limited; second, there is only one air inlet, that is, one muffler can only be installed on one cylinder, and the silencer resonance tube is always The length is 340mm, and the inner diameter of the muffler barrel is 50mm, so it is only suitable for installation on a single-cylinder or two-cylinder engine. If it is installed on a four-cylinder aviation piston engine, four mufflers are required, and its volume and weight are large, which will increase significantly. The overall size and weight of the engine cannot meet the structural size and weight restrictions of the UAV; third, it has only one fixed point for installation, and after installation, a cantilever structure will be formed at the muffler barrel, which has low reliability; fourth, the patent does not Describe in detail the structure of the installation interface between the muffler and the engine, so its structure is not suitable for installation on two-stroke four-cylinder aviation piston engines or other displacement engines

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