CN210221279U

CN210221279U - Abnormal sound detection circuit for motor or engine

Info

Publication number: CN210221279U
Application number: CN201921529164.8U
Authority: CN
Inventors: Houchao Liang; 梁厚超; Jingzhao Li; 李景照; Wei Li; 李卫
Original assignee: Shunde Polytechnic
Current assignee: Shunde Polytechnic
Priority date: 2019-09-13
Filing date: 2019-09-13
Publication date: 2020-03-31
Anticipated expiration: 2029-09-13

Abstract

The utility model relates to a motor or engine abnormal sound detection circuitry for the unusual noise detection of motor or engine in operation, the circuit board sets up in the shell, set up the display screen on the shell, draw forth the detection probe from the shell, the built-in microphone of detection probe, the input of detection circuitry is connected to the microphone, the singlechip is connected to the output of detection circuitry, alarm system, data acquisition module, display screen are connected to the singlechip; the detection circuit comprises a primary audio amplification circuit, a high-pass filtering circuit, a secondary audio amplification circuit and a comparison circuit which are sequentially connected, wherein signals output by the microphone are amplified and filtered by the filter to remove signals of normal operation of the machine, abnormal noise signals are amplified by the secondary audio amplification circuit and then are sent to the comparison output circuit to form pulse signals which are consistent with the abnormal noise and output. The utility model discloses can eliminate environmental disturbance noise, normal running noise science to the engine/motor abnormal sound condition is looked for simply, accurately.

Description

Abnormal sound detection circuit for motor or engine

Technical Field

The utility model belongs to the technical field of motor or engine, concretely relates to motor or engine abnormal sound detection circuitry.

Background

When the engine/motor is in operation, abnormal sounds generated inside the mechanical structure are various, and abnormal sounds generated during the operation of the engine and exceeding the design requirements (technical documents) are often called abnormal sounds. The repeated abnormal sound is often an expression mode that the engine/motor has faults, and the abnormal sound needs to be removed when the engine/motor is subjected to factory inspection and after-sale use, and then the reason for the abnormal sound is found out. However, the judgment of abnormal sound is difficult, and at present, although there is a special device for detecting the operating sound power level, a special detection environment (such as a noise room) is often needed, and a professional person is needed to make a professional judgment on the detection result, so that the detection cost is very high. After the product is sold, the detection and accurate judgment of abnormal sound are more difficult to realize, the abnormal sound judgment mainly depends on manual experience, and the accuracy and the efficiency are low. For example, when an automobile engine is started, other parts of the automobile are in working states at the same time, and sounds generated by vibration are overlapped with each other, at this time, it is more difficult to simply and accurately judge whether the engine is abnormal or not.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a motor, or engine abnormal sound detection circuitry just can accurately judge whether have unusually through probe contact motor, or engine case to overcome prior art's not enough.

The technical proposal of the utility model for solving the technical problem is that: the utility model provides a motor, or engine abnormal sound detection circuitry for the unusual noise of motor or engine in the operation detects, and the circuit board setting is in the shell, set up the display screen on the shell, draw forth test probe, its characterized in that in the shell: the circuit board comprises a detection circuit, a data acquisition module and an alarm system, a microphone is arranged in the detection probe, the microphone is connected with the input end of the detection circuit, the output end connected with the detection circuit is connected with a single chip microcomputer, and the single chip microcomputer is connected with the alarm system, the data acquisition module and a display screen; the detection circuit comprises a primary audio amplification circuit, a high-pass filter circuit, a secondary audio amplification circuit and a comparison output circuit which are sequentially connected, wherein a signal output by a microphone is amplified by the primary audio amplification circuit, a low-frequency noise signal generated by normal operation of a motor or an engine is filtered by a high-pass filter, an abnormal noise signal generated in the operation of the motor or the engine is amplified by the secondary audio amplification circuit, and then the abnormal noise signal is sent to the comparison output circuit to form a pulse signal output consistent with the abnormal noise.

The detection probe comprises a detection finger and a handle, the detection finger comprises a long and thin rod-shaped finger rod and a sleeve, a microphone is arranged in the sleeve, and an air cavity is arranged at the front end of the microphone.

The handle is provided with a wire groove, and a connecting wire of the microphone is led out from the wire groove and is connected with the detection circuit.

The handle comprises an external thread connecting part and a holding part, wherein the external thread connecting part is in threaded connection with a sleeve of the detection finger.

The handle further comprises a cylinder part, the outer diameter of the cylinder part is the same as that of the sleeve, and the wire guide groove penetrates through the external thread connecting part, the cylinder part and the handle part.

The utility model has the advantages that:

the utility model discloses a probe contact in-service engine/motor, on the microphone vibrating diaphragm in conducting the vibration of engine/motor self to the probe chamber, filter the normal sound of engine through amplifier circuit, filter circuit again to obtain the product and whether have the result of abnormal vibration, the utility model discloses can eliminate environmental disturbance noise, normal running noise science, thereby find out the abnormal sound condition of engine/motor simply, accurately. The detection is convenient, rapid and accurate.

Drawings

Fig. 1 is a circuit diagram of the abnormal sound detection circuit of the motor or the engine of the present invention.

Fig. 2 is a waveform diagram of the detection circuit before and after comparing the output circuit.

Fig. 3 is a schematic structural diagram of the detection probe of the present invention.

Fig. 4 is a sectional view of the structure of the detection probe of the present invention.

Detailed Description

The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

When the engine/motor normally operates, uniform and light buzzing sound without noise and special sound can be generated, and if the noise is too high, the noise comprises electromagnetic noise, bearing noise, mechanical friction and the like, the noise can be a failure precursor or a failure phenomenon, so that detecting the noise and judging abnormal sound are important rings for judging the product quality. However, the judgment from ear hearing and experience is often inaccurate and is easily interfered by environmental noise. The utility model discloses a probe direct contact engine/motor, the probe only conducts the running noise of machine, can reject the interference of environment noise, provides the guarantee for hou mian sound detection circuitry and singlechip discernment.

The noise detection of the device applies the working principle of a microphone, and air in a probe cavity is influenced by an engine to generate vibration pressure difference, so that a diaphragm of the microphone vibrates to push a magnet inside the diaphragm to form variable current. Since the air vibration source of the probe cavity is the vibration transmission of the engine/motor, the noise of the external environment does not influence the detection result.

Referring to fig. 1-4, the abnormal sound detection circuit of the motor or the engine mainly comprises a detection probe, a microphone, a sound detection circuit board, a display screen and an alarm system. The structure of the detection probe is shown in fig. 3-4, a microphone is arranged in the detection probe, the microphone is connected with a detection circuit of a sound detection circuit board, the sound detection circuit board comprises a data acquisition module, and an alarm system and the data acquisition module are connected with a display screen. Referring to fig. 1, the detection circuit includes a first-stage audio amplification circuit 1, a high-pass filter circuit 2, a second-stage audio amplification circuit 3, and a comparison output circuit 4, which are connected in sequence, and the four circuits are based on an operational amplifier and combined with different combinations of capacitors and resistors to form an amplification circuit, a filter circuit, and a comparison circuit. The connecting socket P3 of the first-stage audio amplifying circuit 1 is connected with a microphone, so that the input signal of the microphone is input through the connecting socket P3, the signal output by the sound pick-up is amplified through the first-stage high-sensitivity audio amplifying circuit, the low-frequency noise signal generated by the normal operation of the motor is filtered through the high-pass filter, the abnormal noise signal (with higher frequency) generated in the operation of the motor is amplified through the second-stage audio amplifying circuit, and then the abnormal noise signal is sent to the comparison circuit to form the pulse signal output consistent with the abnormal noise. The connection socket P2 of the comparison output circuit 4 is connected with the singlechip. The display screen can display the pulse signal waveform after comparing the output circuit, and display the detection result in an intuitive mode. The shown graphs are compared through the internal calculation of the single chip microcomputer, and when the comparison result is abnormal sound, the alarm system sends out alarm signals on a display screen, such as alarm information of characters, colors and the like. The alarm mode is a conventional technical means in the prior art, and is not described herein again. Fig. 2 is a waveform diagram of a noise signal displayed on an oscilloscope by an abnormal sound motor, wherein a curve S is a waveform of the noise signal at the front end of a comparison output circuit, and a curve Y is a waveform of a noise pulse signal after the comparison output circuit. In order to visually reflect the abnormal noise condition of the motor/motor, the display screen of the device can display the noise pulse signal waveform passing through the comparison output circuit.

The single chip microcomputer reads the noise pulse signals after comparing the output circuit and identifies whether the abnormality is judged according to the rule that whether a section of pulse signals appears periodically or not, usually, the section of pulse signals reflects the emission of abnormal noise, as shown in fig. 2, three sections of pulse signals appear within 0.5 second, the noise can be considered to repeatedly appear three times within 0.5 second, at the moment, the single chip microcomputer judges that abnormal sound appears in the motor/motor, and the system emits an alarm signal. If the pulse signal is happened and is not repeated regularly, the single chip microcomputer judges that the sound pulse is not abnormal sound which needs to be checked and found by the device, but is an interference signal. Generally, for an engine/motor, pulse square wave groups appear in 1 second of pulse signals caused by abnormal sound, so that the system reads data with a time length of more than 1 second when a singlechip recognizes a fault, selects an appropriate data recognition time length of 2 seconds, and performs detection and recognition for multiple times to prevent misjudgment.

The structure of the detection probe is shown in fig. 3-4, the detection probe 10 comprises a detection finger 11 and a handle 12, the detection finger 11 comprises a long and thin rod-shaped finger rod 111 and a sleeve 112, one end of the sleeve 112 is sealed, the finger rod 111 extends out of the outer plane of the sealed end of the sleeve 112, the other end of the sleeve 112 is open, an air cavity 113, a microphone installation cavity and an internal thread connection cavity are arranged in the inner cavity of the sleeve 112, the air cavity 113 is close to the sealed end of the sleeve 112, the microphone installation cavity is matched with the shape of a microphone 6, the handle 12 is a cylinder body and comprises an external thread connection part 121, the outer diameter of the cylindrical part 122 is the same as that of the sleeve 112, the external thread connecting part 121 and the internal thread connecting cavity of the detection finger form a thread connecting pair, a wire groove is arranged through the external thread connecting part 121, the cylindrical part 122 and the handle part 123, a connecting lead 7 of the microphone 6 is arranged in the wire groove, and the connecting lead 7 is led out from the wire groove and is connected with a circuit board in the device shell. During detection, the finger rod 111 contacts the shell of the motor, vibration of the motor is conducted to the air cavity through the finger rod, the air in the cavity is vibrated, input of the microphone is formed, and the microphone converts the vibration into an electric signal and outputs the electric signal to the detection circuit.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents, and all changes that can be made without inventive step are intended to be embraced therein.

Claims

1. The utility model provides a motor, or engine abnormal sound detection circuitry for the unusual noise of motor or engine in the operation detects, and the circuit board setting is in the shell, set up the display screen on the shell, draw forth test probe, its characterized in that in the shell: the circuit board comprises a detection circuit, a data acquisition module and an alarm system, a microphone is arranged in the detection probe, the microphone is connected with the input end of the detection circuit, the output end connected with the detection circuit is connected with a single chip microcomputer, and the single chip microcomputer is connected with the alarm system, the data acquisition module and a display screen; the detection circuit comprises a primary audio amplification circuit, a high-pass filter circuit, a secondary audio amplification circuit and a comparison output circuit which are sequentially connected, wherein a signal output by a microphone is amplified by the primary audio amplification circuit, a low-frequency noise signal generated by normal operation of a motor or an engine is filtered by a high-pass filter, an abnormal noise signal generated in the operation of the motor or the engine is amplified by the secondary audio amplification circuit, and then the abnormal noise signal is sent to the comparison output circuit to form a pulse signal output consistent with the abnormal noise.

2. The motor or engine abnormal noise detection circuit according to claim 1, characterized in that: the detection probe comprises a detection finger and a handle, the detection finger comprises a long and thin rod-shaped finger rod and a sleeve, a microphone is arranged in the sleeve, and an air cavity is arranged at the front end of the microphone.

3. The motor or engine abnormal noise detection circuit according to claim 2, characterized in that: the handle is provided with a wire groove, and a connecting wire of the microphone is led out from the wire groove and is connected with the detection circuit.

4. The motor or engine abnormal noise detection circuit according to claim 3, wherein: the handle comprises an external thread connecting part and a holding part, wherein the external thread connecting part is in threaded connection with a sleeve of the detection finger.

5. The motor or engine abnormal noise detection circuit according to claim 4, wherein: the handle further comprises a cylinder part, the outer diameter of the cylinder part is the same as that of the sleeve, and the wire guide groove penetrates through the external thread connecting part, the cylinder part and the handle part.