45 results about "Acoustic Noise Testing" patented technology

The invention discloses an oil pump noise test device. The device comprises a base supporting frame, a base supporting air cylinder and a vibration sensor unit; the upper end of an oil pump to be tested is hung and fixed, the base supporting frame vertically moves along with the telescopic motion of an ejector rod of the base supporting air cylinder, and when the base supporting frame moves to the upper end, the oil pump to be tested is supported; when the base supporting frame moves to the lower end, the oil pump to be tested is separated from the base supporting frame and is in the midair-suspending state; and the vibration sensor unit can be mounted on and fixed to a shell of the oil pump to be tested in a combined manner, and the vibration sensor unit is used for detecting output vibration signals. The invention further discloses an oil pump noise test method. According to the oil pump noise test device and test method, the actual level of the noise of the oil pump to be tested can be accurately reflected.

The invention relates to an electric locomotive speed reducer assembly noise testing device and a testing method thereof. The electric locomotive speed reducer assembly noise testing device comprisesa rack, a speed reducer connecting mechanism, a half-shaft axle housing connecting mechanism and a load mechanism are connected with the rack, and the speed reducer connecting mechanism comprises a transmission mechanism which comprises a rotating base and a motor connecting flange base; the speed reducer assembly is pressed on the rotating base through a first driving air cylinder, the motor connecting flange base is connected with a driving motor in driving connection with the speed reducer assembly, the half-shaft axle housing connecting mechanism comprises an axle housing body, an upper axle housing body connecting oil filling port, a lower axle housing body connecting oil filling port and an oil drain valve, two half shafts penetrate through the two sides of the axle housing body, andthe axle housing body is further connected with a second driving air cylinder. The load mechanism comprises a sliding shaft, the two ends of the sliding shaft are connected with a rotating shaft anda third driving air cylinder respectively, the rotating shaft is connected with a disc brake disc, and the sliding shaft matching the disc brake disc is connected with disc brake pincers. The electriclocomotive speed reducer assembly noise testing device and the testing method thereof are used for testing noise generated when the speed reducer assembly runs, and testing installation and operationare simple.

The invention discloses a method for quickly evaluating the sound insulation performance of a ship bulkhead structure. The method comprises the following steps: step 1, establishing a sound insulationperformance simulation test model; step 2, setting physical parameters of the bulkhead to be measured; and step 3, calculating the weighted sound insulation index of the bulkhead to be measured. According to the invention, a laboratory detection environment for cabin structure noise testing can be simulated. The sound insulation performance of the ship bulkhead structure is subjected to analoguesimulation to acquire the sound insulation performance index of the bulkhead structure. The method can be used for calculating the sound insulation indexes of the ship cabin combined wallboard and thecombined deck. Due to the fact that a bulkhead structure of any combination can be simulated, the defect that a manufacturer test report result is incomplete is overcome. Designers can find a sound insulation structure combination with the optimal cost performance. Design and manufacturing cost is reduced, and great significance is achieved for ship sound insulation calculation and bulkhead structure design.

The invention belongs to the technical field of air conditioner testing, and particularly discloses a method capable of accurately testing the thermal expansion and cold shrinkage abnormal sound condition of an air conditioner indoor unit. According to the testing method, the tested air conditioner indoor unit is installed in a testing room and connected with an external air conditioner outdoor unit, a pickup is arranged at a proper position, after an air conditioner is started to enable the operation state of the air conditioner to be consistent, the air conditioner indoor unit stands by simulating the actual use environment of the air conditioner indoor unit, then the environment temperature is improved, the air conditioner indoor unit is controlled to operate in a low-air heating manner to carry out thermal expansion noise testing, then the air conditioner indoor unit is turned off, meanwhile, the environment temperature is reduced to carry out cold shrinkage noise testing, a thermal expansion noise curve and a cold shrinkage noise curve are drawn according to noise data acquired by the pickup after testing is completed, and finally noise sharp points of the two noise curves which are 2-4 dB (A) higher than respective background noise curves are counted; and the thermal expansion and cold shrinkage abnormal sound condition of the air conditioner indoor unit can be effectively detected, and the accuracy of a testing result is high.

The invention relates to the field of air conditioners, and discloses a variable frequency air conditioner pipeline vibration and low-frequency noise evaluation method which is used for solving the problem that the accuracy of pipeline vibration and low-frequency noise evaluation is low. The method comprises the steps that firstly, a compressor and pipeline system finite element model is established according to structural parameters of a compressor and structural parameters of a pipeline; then, compressor and pipeline coupling vibration simulation is conducted based on the compressor and pipeline system finite element model, vibration noise evaluation is conducted on a simulation result; if the vibration noise evaluation is qualified, the compressor and pipeline system finite element model at the moment is machined into a prototype, and vibration noise testing is conducted on the prototype; and if the vibration noise evaluation is not qualified, the structural parameters of the pipeline are optimized by using an automatic pipeline optimization method, thus re-establishing a compressor and pipeline system finite element model, carrying out coupled vibration simulation, and carrying out vibration noise evaluation on a simulation result. The invention is suitable for variable frequency air conditioner pipeline vibration and low-frequency noise evaluation.

The invention discloses a noise detection method for a range hood. The noise detection method comprises the following steps: step 1, acquiring air performance data of the range hood and drawing an air volume-static pressure curve and an air volume-power curve; step 2,mounting the range hood and noise testing equipment located at a testing point, mounting a smoke tube of the range hood, and mounting an air volume adjusting valve on the smoke tube, wherein according to the air volume-power corresponding relation of the range hood, the motor power of the range hood is adjusted by adjusting the valve opening degree of an air volume adjusting valve, and after the power points of the range hood are controlled to be in one-to-one correspondence with the power points on the air volume-power curve, the working noises of the range hood are measured; and step 3, drawing working noise-power, working noise-air volume and working noise-static pressure curves according to the working noise data obtained through testing. All working states of the range hood are covered, so that noise data better fits the actual experience of a user, and the development work is better guided.

The invention relates to an automobile refrigerant flowing noise testing device and method, and belongs to the field of automobile air conditioning system noise testing. The device comprises an enthalpy difference performance table, and an acquisition and analysis system, a noise reduction system and a tested air conditioner which are arranged in the enthalpy difference performance table. The enthalpy difference performance table comprises a first evaporation chamber, a second evaporation chamber and a condensation chamber which are arranged in a mutually isolated manner, and a refrigerating/heating system and a controller thereof which are arranged on the outer side of the first evaporation chamber, the second evaporation chamber or the condensation chamber. The controller controls the refrigerating/heating system to provide environment temperature and humidity for the first evaporation chamber, the second evaporation chamber and the condensation chamber, so that environment bottom noise is guaranteed to be small during noise testing, environment temperature and humidity control factors are introduced, and the condition of noise caused by refrigerant flowing in real vehicle running is simulated more truly.

The invention discloses a bi-directional automobile special noise testing method. An experimental device used by the method comprises a first sound level meter, a second sound level meter, a third sound level meter, a fourth sound level meter, a high speed data collecting card NI, a computer and a software processing system thereof, a sound-insulating front checking plate, a sound-insulating bottom checking plate, a machine frame, a 12 V accumulator, and a 12 V to 220 V transformer. The device has the beneficial effects of increasing the sound-insulating effect, and testing the noises from two directions of the bottom part and the side face of the device through installing the sound-insulating front checking plate and the first sound level meter and the second sound level meter installed on the sound-insulating front checking plate, the sound-insulating bottom checking plate and the third sound level meter and the fourth sound level meter installed on the sound-insulating bottom checking plate, the high speed data collecting card NI, the computer and the software processing system thereof, discovering the noise frequency distribution of the device in time through FFT data processing of a time domain signal, and providing the reliable experimental data for the automobile noise reduction. The structure is simple, the operation is convenient, and the device is economical and practical.

The invention discloses a selecting method for an air inlet ring of a fan system. The fan system comprises a volute, an impeller arranged in the volute and the air inlet ring arranged at an air inlet of the volute. The air inlet ring comprises a radial flow guide part, an axial flow guide part axially extending from the radial inner side of the radial flow guide part to the inside of the volute and a net arranged on the radial inner side of the radial flow guide part, meshes are formed in the net, the inner diameter of the axial flow guide part is D1, the hole diameter of the meshes is D0, the height of the axial flow guide part is d, and the distance between the air inlet and the impeller is d1. The selecting method comprises the following steps that (1) the ranges of three parameters D1, D0 and d of the air inlet ring are limited; and 2) each parameter value is determined by adopting a control variable method: taking one parameter as a variable, changing the variable, keeping other parameters unchanged, carrying out noise test and air volume test, observing the noise condition under the condition of ensuring that the air volume is unchanged, and selecting a value corresponding to the variable when the noise is minimum as a corresponding size numerical value of the air inlet ring.

The invention belongs to the field of electrical equipment, and specifically relates to a working method of environment-friendly noise-reducing power generation equipment. A control module, a plurality of noise testers connected with an input end of the control module, a machine room, a plurality of generator units arranged in the machine room, a sound-absorption compound fabric laid at the innersides of walls of the machine room, and a stretching assembly located at the bottom of the sound-absorption compound fabric are comprised; the noise testers are located at the periphery of the machineroom, and used for detecting the quantity of a noise escaped from the machine room; and the control module is applicable to controlling the stretching assembly to stretch the sound-absorption compound fabric into wave lines with adjustable wave trough depths, so that the noise generated by the generator units is absorbed, and the detection value of the noise quantity is enabled to meet a set threshold value. The outward radiation of the noise in the machine room can be effectively reduced, and noise pollution to an environment is reduced.

The invention relates to the technical field of earphone noise reduction testing, in particular to a testing device and method for a noise reduction earphone, and the device comprises an isolation box body which is provided with a sealing door used for sealing the isolation box body; the table top is connected into the isolation box body in a displaceable manner through a first adjusting mechanism and can extend out of the isolation box body or be stored in the isolation box body; the earphone placing frame is arranged in the middle of the table top; the loudspeakers are arranged on the two sides of the earphone placing frame in a displaceable mode through second adjusting mechanisms, and the position angles of the loudspeakers can be adjusted relative to the earphone placing frame. Through the arrangement, the table top can be moved into the isolation box body, so that the whole testing device is located in a closed space, the testing result is not influenced by external factors, the accuracy of the testing result is ensured, noise testing in different directions can be carried out on the earphone by moving the position of the loudspeaker, and the testing efficiency is improved. Therefore, the noise reduction function of the earphone is comprehensively tested, and the accuracy of a test result is improved.

The invention discloses a noise testing device and a noise testing method for a duct type air conditioner. The device comprises a housing which is internally provided with an assembly cavity for the assembly of a duct type air conditioner, a first air return part arranged on one side wall of the housing and communicated with an external space and the assembly cavity, a second air return part arranged at the bottom of the housing and communicated with the external space and the assembly cavity, an air outlet part communicated with the assembly cavity and arranged on the side wall, opposite to the first air return part, of the housing, a hoisting part arranged on the outer side of the housing and used for hoisting the testing device, a noise pickup device for picking up a noise value, and amain controller in communication connection with the noise pickup device and at least capable of receiving noise signals sent by the noise pickup device. Therefore, problems of large noise value deviation and low measurement accuracy of a wind pipe machine noise test in the prior art are solved.

The invention provides a motor concentricity comparison method, system and device and a computer readable storage medium. The method comprises the following steps: S1, numbering all motors: 1, 2, 3...; S2, installing the motor 1, the motor 2, the motor 3 and the like on a using machine type, carrying out single-air-outlet noise testing, andcalculating the rotating frequency according to the actualrotating speed of the motor, wherein the rotating frequency is equal to the actual rotating speed of the motor/60; S3, collecting noise under different rotation frequencies when the motor 1, 2, 3...work through a noise tester; S4, comparing the noise of the motors 1, 2, 3... at a special rotating frequency point andcarrying out ranking, wherein the motor with the smallest noise value is the motor with the best concentricityofthe stator and the rotor; the method has the advantages that the noise of the stator and the rotor of the motor at a special rotating frequency point is used as a measurement standard, and the concentricity of the stator and the rotor of different motors can be rapidly, simply and conveniently compared.

The invention provides an outdoor unit noise testing device and method. The device comprises a detection chamber, a data processing device, a data acquisition device and a power supply device. The data processing device and the power supply device are arranged outside the detection chamber; the data processing device is connected with the power supply device; the detection chamber comprises an enclosing wall, a ceiling and a partition wall. The enclosing wall is matched with the ceiling, and the partition wall is matched with the enclosing wall and the ceiling and divides the detection chamberinto an indoor side and an outdoor side; the air conditioner outdoor unit is arranged on the outdoor side, the indoor unit is arranged on the indoor side, the air conditioner outdoor unit is connected with the indoor unit, the data acquisition device is arranged on the outdoor side, the data processing device is connected with the data acquisition device, the power supply device comprises a variable-frequency power supply and a harmonic generator, the variable-frequency power supply is connected with the harmonic generator, and the harmonic generator is connected with the indoor unit. According to the outdoor unit noise testing device and method, the influence of power supply harmonics on outdoor unit noise testing is eliminated to the maximum extent, and the accuracy of outdoor unit noise detection is improved.