7results about How to "Improve noise reduction efficiency" patented technology

The utility model relates to a new car roof structure for medium -high speed elevator, aims at the demand of reducing elevator shaft pit depth. Including car roof welding spare (1), perforated plate (2), sound insulation material (3) and car roof sealing plate (4), its car roof welding spare (1) as core bearing matrix, adopts the design of grid reinforcing rib, and the reinforcing rib height is 20 50mm, and the interval is 200 400mm, the perforated plate (2) is laid on the upper portion of car roof welding spare (1), is fixed through the drill tail silk, the sound insulation material (3) selects polyurethane foam or glass fiber cotton thickness 10 30mm, the car roof sealing plate (4) adopts galvanized steel sheet or stainless steel sheet, and the edge sets up the bending structure, the utility model not only guarantees the strength and rigidity of elevator car bottom, also effectively improved the security and operation effect of overall structure, is applicable to the elevator equipment that needs shallow pit installation.

The utility model relates to muffler technical field, concretely is a kind of muffler device for gasoline engine, including muffler shell, air inlet pipe and exhaust pipe, muffler shell is equipped with baffle one and baffle two, and the shell is divided into first chamber, second chamber and third chamber, the top end of air inlet pipe is elbow and is located in second chamber;Baffle one and baffle two are equipped with the connecting pipe between first chamber and third chamber, exhaust pipe penetrates baffle one, baffle two and the top of muffler shell, so that first chamber is connected with the outside space of muffler shell.Its advantages are: first, it is equipped with three chambers, gas is discharged from second chamber, then passes through third chamber and first chamber, and finally discharged from exhaust pipe, due to the change of airflow by three chambers and the increase of resonance time of gas between chambers, noise is reduced;Second, exhaust pipe is equipped with sound-absorbing cotton, and honeycomb board is further equipped between exhaust pipe and connecting pipe, which greatly reduces noise and improves sound-absorbing efficiency.

The utility model relates to refrigerating machine technical field discloses a kind of muffler for refrigerating machine, comprising: sound-absorbing shell, and the air inlet pipe and air outlet pipe for air flow in and out, the sound-absorbing shell top is equipped with the sound-absorbing cover body for air outlet pipe installation;Through the cooperation between sound-absorbing shell, sound-absorbing cover body and multistage sound-absorbing mechanism, through the setting of the outer diameter and the aperture of first sound-absorbing disc, second sound-absorbing disc and third sound-absorbing disc gradually decrease from top to bottom, can make airflow when flowing through multistage sound-absorbing mechanism, constantly change flow direction and speed, under the blocking effect of first sound-absorbing disc, second sound-absorbing disc and third sound-absorbing disc, sound wave energy is weakened multiple times, simultaneously, increase the contact area and contact time of airflow and multistage sound-absorbing mechanism, further improve sound-absorbing efficiency, effectively reduce the noise generated in the operation process of refrigerating machine, create quiet environment for equipment stable operation.

The utility model relates to the technical field of gas turbine power generation, in particular to gas turbine combined cycle power generation low-noise emission equipment which comprises a sound absorption box body, a box door is hinged to one side of the sound absorption box body, and through holes are formed in the two faces of the sound absorption box body respectively. The silencing box body is arranged in the sound absorption box body, an air inlet is formed in one side of the silencing box body, an air outlet is formed in the other side of the silencing box body, and the air inlet and the air outlet are matched with the through holes in the two faces of the sound absorption box body respectively. Compared with the prior art, by arranging the silencing box body, the multistage serially-connected silencing cavities and the complex airflow path, stage-by-stage attenuation, disturbance and dissipation of sound waves are effectively achieved, linear propagation and high-frequency impact of noise are avoided, the noise reduction efficiency is improved, and the noise pollution risk of the system is reduced.

The utility model relates to the field of damping rubber sheet, specifically disclose a damping rubber sheet for car, including damping rubber sheet main part, damping rubber sheet main part includes from top to bottom sequentially arranged corrosion -resistant protective layer, reinforcing layer, double damping layer, magnetic composite layer, first adhesive layer, double damping layer includes laminated arrangement and close reinforcing layer's upper damping layer, far away reinforcing layer's lower damping layer, the upper damping layer, lower damping layer all are provided with a plurality of sound absorption holes, the porosity of upper damping layer is greater than the porosity of lower damping layer. Double damping layer can carry out graded absorption and processing to the noise of different frequency, and the larger porosity of upper damping layer is favorable to absorb middle high frequency noise, and the smaller porosity of lower damping layer has better absorption effect to low frequency noise, thereby can effectively widen the noise reduction frequency band of this damping rubber sheet, significantly improve the overall noise reduction performance, can effectively reduce various noises in the car, create a quiet and comfortable in-car environment for the driver and passenger.

The utility model provides modular assembly type road sound insulation screen frame relates to road sound insulation screen technical field, including bottom plate, the four corner of bottom plate installs the positioning pin, the top of bottom plate installs lower mounting seat, the both sides inside lower mounting seat installs lower cross bar, the top inside lower mounting seat installs vertical pole, the top of vertical pole installs upper mounting seat, the both sides inside upper mounting seat installs upper cross bar, the inside of lower mounting seat is provided with connecting mechanism, through being provided with connecting mechanism in the inside of lower mounting seat, the mutual match between the positioning hole, the locating piece, the screw groove, the threaded rod and the rotating block of utilizing connecting mechanism, can carry out convenient disassembly and installation handling to vertical pole, can realize module standardization quick butt joint, need not complex procedure, greatly shorten single section assembly time, can replace module alone in local damage, reduce maintenance cost, also promote transportation space utilization, save engineering cost.

The application belongs to the field of variable frequency range hood, and discloses a noise reduction method and device. The method comprises the following steps: acquiring the current torque and the current rotating speed of a motor in a range hood; inputting the current torque and the current rotating speed into a pre-trained noise identification model to output a first noise identification result; if the first noise identification result is 0, outputting a noise prompt message to enable a user to adjust the torque and the rotating speed of the motor; and the first noise identification result being 0 indicates that the noise generated by the motor based on the current torque and the current rotating speed is greater than a preset noise threshold. The application can achieve noise reduction without structural changes.