Engine knock monitor and operation method thereof

Abstract

The invention provides an engine knock monitor and an operation method thereof, and belongs to the technical field of engine tests. The engine knock monitor comprises a monitoring module, a first knock sensor, a second knock sensor, four double-core shielding wires and an ECU, wherein the first knock sensor and the second knock sensor are connected with the ECU and the monitoring module simultaneously through the two double-core shielding wires, and the first knock sensor and the second knock sensor are used for sending knock signals to the ECU and the monitoring module when an engine knocks; the ECU is used for processing the knock signals; and the monitoring module is used for buffering and amplifying the knock signals, separating out effective knock signals and playing the effective knock signals. The monitor provided by the invention can effectively suppress noises, improve the signal-to-noise ratio, fully filter invalid audio signals, realize low-noise and high-definition engine knock monitoring, effectively reduce auditory fatigue and improve the work efficiency.

Description

technical field [0001] The invention relates to an engine knocking listener and an operating method thereof, belonging to the technical field of engine testing. Background technique [0002] Engine detonation is also called deflagration, which is an abnormal combustion process. Severe detonation can easily cause engine damage. The center frequency range of detonation is in the 5kHz-15kHz frequency band, which is in the audible frequency range of the human ear. In the engine test During the process, engineers and testers need to monitor the engine knock in order to adjust the calibration data in time to avoid engine damage. At present, there are two ways to monitor knocking. The first way is to use a copper tube to connect to the appropriate position of the cylinder (close to the top dead center of the piston movement), and then introduce the copper tube into the control room to monitor the knocking. Due to the current The structure of the engine is becoming more and more co...

AI Technical Summary

Problems solved by technology

At present, there are two ways to monitor knocking. The first way is to use a copper tube to connect to the appropriate position of the cylinder (close to the top dead center of the piston movement), and then introduce the copper tube into the control room to monitor the knocking. Due to the current The structure of the engine is becoming more and more compact, and generally there is no special connection position for knock monitoring. This method is hard connection, so it is difficult to find a suitable assembly position, and there are common problems such as interference and assembly difficulties; the second method is Use an independent knock sensor outside the engine EFI system, assemble it to a suitable position on the cylinder block, and then connect it to an active speaker to amplify and monitor the knock. This method is also not easy to find a suitable assembly position, and because The knock sensor is a piezoelectric element with high output impedance, which seriously does not match the input impedance of ordinary active speakers. The audio signal of active speakers is in the form of unbalanced input, which is very easy to introduce interference through connecting wires, so the signal-to-noise ratio Poor; in addition, since the frequency band of the knock signal is above 5KHz, the frequency response range of the active speaker is 20Hz-20KHz, and there are many other useless noises of the engine in the signal transmitted by the knock sensor, which is also emitted by the speaker, which is easy to cause Hearing fatigue, so it is very necessary to design and invent an engine knock monitor that can solve the above problems

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