1539results about How to "Improve the noise reduction effect" patented technology

A blender includes a base frame, a cover for covering the base frame, a muffler housing, a motor, and a fan. The base frame includes a hollow column having a compartment for receiving the motor. Two separating plates extend downward from a bottom end of the base frame. The motor includes a lower drive shaft for driving the fan for driving ambient cool air into the compartment of the hollow column via the apertures, thereby directly cooling the motor. The separating plates prevent the hot air exiting the blender from entering the blender again.

The invention provides an improved opposite impact silencer. The improved opposite impact silencer comprises a gas inlet and an exhaust port, wherein more than one shunting opposite impact units which are connected end to end are arranged between the gas inlet and the exhaust port; each shunting opposite impact unit comprises two shunting passages which are used for symmetrically dividing the inlet flow into two, and confluence channels which are used for oppositely converging the gas flow in the two shunting passages from the front; gas outlets are respectively formed in the channel walls of the two confluence channels; the gas outlets are symmetrical about the converge center of the gas flow; each gas outlet is over 5 cm away from the converge center of the gas flow; the gas outlet of the previous shunting opposite impact unit is the gas inlet of the next shunting opposite impact unit. The improved opposite impact silencer has a smaller size, and has an excellent noise elimination effect compared with the patent application with application number 201210267691. 2.

The invention relates to a variable-frequency microperforated pipe silencer with variable perforation section lengths. The silencer comprises a main pipeline, a sleeve piston, an outer pipeline and a sleeve position adjusting device. The middle section of the main pipeline is a perforated pipe provided with microperforated-holes, the sleeve piston is arranged outside the main pipe in a closely-attached and sleeved mode, a disk is arranged on the head portion of the sleeve piston, the tail portion of the sleeve piston is connected with the sleeve position adjusting device, one end of the outer pipeline is connected to the main pipeline in a sealing mode, the other end of the outer pipeline is connected to the outer side of the sleeve piston through an end cap and enables the disk of the sleeve piston to be connected with the inner wall of the outer pipeline in an attached mode, an expansion cavity is formed by enclosure of the outer pipeline, and the main pipeline and the disk. The expansion cavity is communicated with a fluid channel of the main pipeline through the microperforated-holes, and therefore the effect of silencing can be achieved; the sleeve position adjusting device drives the sleeve piston to axially slide on the main pipeline to adjust effective lengths of the expansion cavity and a microperforated pipe, and therefore silencing frequency of the silencer can be adjusted. Compared with the prior art, the variable-frequency microperforated pipe silencer has the advantages of being simple in structure, adjustable in silencing frequency, and the like.

The invention relates to a muffler for an exhaust system of an internal combustion engine, consisting a housing having at least one exhaust inlet and at least one exhaust outlet and having at least two pipes at the inlet end or at the outlet end, at least one of which is switchable by a control device at least between an open state and a closed state and is acoustically coupled to a silencer system, such that the silencer system is active when the switchable pipe is opened as well as when it is closed and has a different damping characteristic when the switchable pipe is opened than when the switchable pipe is closed.

A floor covering characterized as having a strong noise-reducing properties for the interior trim of means of transport. The floor covering has, on the passenger side, a textile or non-textile surface, acoustically coupled through at least one microperforated sheet to a fibrous non-woven and/or foamed plastic. A microperforated sheet having a hole diameter from 0.2 to 0.5 mm and an interhole distance from 3 to 7 mm.

The invention discloses a vibration signal noise reduction method based on variable-step-length LMS-EEMD. The method includes: acquiring an initial noise reduction signal according to an original signal; decomposing the initial noise reduction signal, and selecting an IMF component needed in noise reduction; acquiring a final noise reduction signal according to the original signal and the selected IMF component. By the method, the defects of complex operation process, high noise pollution and weak noise reduction capability in the prior art can be overcome, and simple operation process, low noise pollution and strong noise reduction capability are achieved.

A car muffle comprises a housing (1), an inlet pipe (4) and an outlet pipe (5), wherein, the car muffle further comprises at least a clapboard (2), a resonance pipe (6) and a control valve (8). The outer margin of the clapboard (2) is in sealed connection with the inner wall of the housing (1) and the inner part of the housing (1) is divided into at least two non-communicated chambers (3), and the inlet pipe (4) is inserted from one end of the housing (1); the outlet pipe (5) is inserted from the other end thereof; through-holes are formed on the circumference of the pipe body of the inlet pipe (4) which is positioned inside the chamber where the a port of the outlet pipe (5) is disposed; the control valve blocks off the port (6A) at one end of the resonance pipe (6) and a valve control device (9) controls the opening degree of the valve (8). The muffle can automatically adjust the area of airflow according to air displacement so as to adapt to different working conditions of the engine, thus improving noise elimination effect and reducing exhaust backpressure.

The invention discloses an automatic dust collector, belonging to the technical field of dust collectors. The dust collector comprises a supporting frame, a dust collecting unit arranged on the supporting frame, an air regulation device, a silencing device, a water circulator and a control system, wherein the top of the dust collecting unit is provided with a water inlet pipe; the end of the water inlet pipe is provided with a sprayer; a dust collection filter screen is arranged in the dust collecting unit; one side of the dust collecting unit is provided with an air inlet pipe connected with a blower; the other side of the dust collecting unit is provided with an air outlet pipe; the air regulation device is arranged on the air inlet pipe; the silencing device is connected with an air outlet of the blower; the water circulator is connected with the water inlet pipe; the water inlet pipe is provided with a water regulating valve; a dust concentration sensor is arranged in the dust collecting unit; and the control system is respectively connected with the air regulation device, the water regulating valve and the dust concentration sensor. The automatic dust collector can achieve favorable automatic dust collection effects, implements favorable silencing effects, and performs the functions of energy saving and environmental protection.

A noise reduction device used on rebreather is prepared as setting spiral air passage at internal of said device, arranging air inlet at external end of said air passage and air outlet at internal end center of said air passage, setting round arc-surface structure on side wall of spiral air passage and convex shoulder between side wall top-edge and air inlet. The said noise reduction device is installed at air inlet of fan on rebreather.

The invention discloses a mute motor inner cover, a mute motor and a dust collector provided with a mute motor. The mute motor inner cover for the dust collector comprises an inner housing defining an accommodating cavity for accommodating a motor body and an outer housing which is an integrally formed part, wherein a first outlet is formed in the side wall of the inner housing, the inner housing is detachably arranged in the outer housing, an airflow channel is defined between the outer housing and the inner housing, a second air outlet is formed in the outer housing, the first air outlet and the second air outlet are respectively communicated with the airflow channel, and a mute cavity is defined in the outer housing, is located between the first air outlet and the second air outlet and is communicated with the first air outlet. According to the mute motor inner cover for the dust collector, the number of parts is decreased, convenience is brought to mounting and dismounting, damage is not likely to occur, and the problem of inverse mounting can be also prevented. In addition, the mute cavity can be defined in the outer housing, and the mute effect of the motor inner cover for the dust collector can be further improved.

The invention discloses an automobile noise reduction system with one-fourth wavelength pipes combined with a Helmholtz silencer, and belongs to the technical field of environment control and improvement in order to solve the problems that an existing automobile noise reduction system is high in manufacturing cost, poor in noise elimination effect, high in air inlet resistance and consumed power, poor in fuel economy and not suitable for various automobiles. The Helmholtz silencer is communicated with the side wall of a front air inlet guide pipe, the front air inlet guide pipe is communicated with an air filter, an air filtering net is arranged in the air filter, the air filter is communicated with a first rear air inlet guide pipe, the first rear air inlet guide pipe is communicated with a second rear air inlet guide pipe through a flexible connecting pipe, an air throttling valve is arranged on the second rear air inlet guide pipe, the second rear air inlet guide pipe is communicated with an air inlet header pipe, the air inlet header pipe is communicated with an air inlet manifold, and one ends of the two one fourth wavelength pipes are both connected and communicated with the side wall of the first rear air inlet guide pipe. According to the system, while power property and economy of an automobile are maintained, the noise of the whole automobile can be lowered particularly, the environment quality can be improved, and the system is suitable for various automobiles.

The invention discloses a flexible silencer which comprises a termination flange, a silencing internal hose, a silencing external hose, an isolation layer, a sound absorbent lining and a composite hose. The flexible silencer is characterized in that: the silencing internal hose is densely equipped with a plurality of silencing holes, the external part of the silencing internal hose is covered with the external silencing hose; the silencing external hose is densely equipped with a plurality of silencing holes, a sound absorbent cavity is positioned between the silencing internal hose and the silencing external hose, a plurality of fixing rings are arranged in the sound absorbent cavity in interval, the external part of the silencing external hose is equipped with the isolation layer, the external part of the isolation layer is equipped with the sound absorbent lining, the external part of the sound absorbent lining is covered with the composite hose, and the silencing internal hose and the internal-circular connector of the termination flange are fixedly connected; the silencing external hose, the composite hose and the connector of the external-circular turned-edge connector of the termination flange are fixedly connected mutually. The flexible silencer is made of the flexible material which can be bent, the sound absorbent material and the reasonable silence structure, the invention can be configured according to the environment condition, and has the advantages of low cost, good silence effect and convenient installation.

The invention discloses a riding mower with a noise reduction measure and hydraulic stepless speed change. The riding mower comprises a steerable front axle, a drivable rear axle with hydraulic stepless speed change, a frame with a double-protection lever, a mowing device with noise reduction, an engine with a noise elimination groove, a head housing with noise reduction, a noise elimination air filtering net, a saddle with noise reduction and a grass collection box with noise reduction, wherein the front axle is connected with two front wheels; the drivable rear axle is ocnencted with two rear wheels; the frame is arranged above the four wheels; the mowing device is arranged below the frame; the engine is arranged above the frame close to the front side; the saddle is arranged on the middle part above the frame close to the rear side; the grass collection box is arranged behind the mower; in addition, for personal protection of a riding operator, accessories such as earplugs, sound-proof cotton, ear muffs and a sound-proof helmet are arranged. The invention also introduces a heightening quadrilateral structure, diagrammatic design of a mowing part, a preferable thinking method and a comprehensive application method of the noise reduction measure to the entire mower.

The invention discloses a snow plough with antiskid chains, an ice tooth and snow brush auger, a heat transfer steam tank and a front exhaust pipe. The heat transfer steam tank is arranged on an engine and a noise eliminator for temperature reduction, and hot steam is guided to the front of the snow plough to locally heat ice to make the ice fragile and further remove the ice, so that two results are gotten from one effort; hot waste gases are also guided to the front of the snow plough through the front exhaust pipe with wedges for noise elimination, so that a noise elimination effect is improved, waste gases which are originally close to an operator are emitted away to keep the operator healthy, and the shortcoming that a part of the waste gases are secondarily mixed into air entering an air filter because a waste gas outlet of a small gasoline engine is close to an inlet of the air filter is also overcome to get four results from one effort; the temperature reduction, difficulty in noise reduction, slipping and advancing incapability, counterweight antiskid, damage of waste gas inhaling to health, secondary gas mixing, thermal insulation and vibration damping, a deicing function and a snow blowing function are comprehensively improved; or perhaps, the snow plough with the antiskid chains for wheels, parabolic blades, the heat transfer steam tank and the front exhaust pipe is created, and belongs to the new technical fields of temperature reduction, noise reduction, energy saving and emission reduction, the auger and a shoveling plate of the snow plough are provided with ice teeth and snow brushes, and gears and racks are used for steering.

The invention discloses an exhaust muffler capable of automatically adjusting the overflow area, which comprises an air inlet pipe, an expansion chamber and an air outlet pipe, wherein the inner circle of the section (provided with radial through-holes) of the air inlet pipe is provided with a piston which can slide to and fro along the inner wall of the pipe, and the front end of the piston faces the air inlet direction, while the rear end is provided with a pressure spring which can apply pressure (with a direction opposite to the air inlet direction) to the rear end. The invention adopts a structure that the exhaust pipe section of the air inlet pipe is provided with the piston which divides the exhaust pipe section into an exhaust part and a closed part, the position of the piston can be automatically adjusted according to the exhaust pressure and the piston can reset under the action of the spring when the exhaust pressure is low; therefore, the exhaust muffler has the advantages of adjusting the area of the airflow ventilating section according to the exhaust gas flow of an engine under different working conditions, keeping the exhaust airflow in an even flow velocity, effectively lowering the exhaust backpressure, reducing the regenerated noise of the airflow, improving the erasure effect of the muffler, and having a positive significance for reducing the fuel consumption and carbon dioxide emission of an automobile.

The invention relates to the field of mufflers, and particularly provides a three-layer series micro-perforated pipe muffler which comprises a muffler body, an intake end and an exhaust end. The muffler body is of a three-layer micro-perforated pipe structure for muffling, aperture ranges from 0.1mm to 0.5mm, porosity is less than 5%, gaps are formed between three-layer micro-perforated pipes without being filled with filling materials, the three-layer micro-perforated pipes are different in aperture, equal in porosity and different in cavity volume, and noise in different frequency bands is eliminated. When the muffler is at work, airflow directly flows through a pipeline, and back pressure loss is low. The exhaust muffler is simple in structure, convenient to process and low in cost, and is resistant to high temperature, corrosion and airflow impact and long in service life as being of a pure-metal structure. The muffler has good muffling effect in the whole spectral range and particularly in high-frequency band, and muffling volume reaches 15-25dB.

The invention relates to an air silencer which comprises an outer barrel body, an air inlet pipe and an air outlet pipe, wherein the inner part of the outer barrel body is partitioned into a first cavity and a second cavity by a partition plate; a plurality of air pipes communicated with the first cavity and the second cavity are arranged on the partition plate; a distance between the first end face, positioned in the first cavity, of the air inlet pipe and the partition plate is smaller than a distance between the second end face, positioned in the first cavity, of each air pipe; a sound absorption structure for sound absorption is formed in the second cavity; a resisting silencer is arranged in the first cavity, and a resistive silencer is arranged in the second cavity, so that low, medium and high-frequency noise in high-speed air flow can be eliminated; after entering the first cavity, external high-speed air flow flows towards the partition plate and then returns so as to enter the second cavity from the air pipes; therefore, all the air flows go through such a 'backflow' process in the first cavity, and the air silencer disclosed by the invention is extremely good in silencing and noise reduction effects under an environment with high pressure difference and high flowing speed.

The invention discloses a double-cavity resonant type muffler, which relates to a double-cavity resonant type muffler for inhibiting pipeline noises, and is formed by connecting an upper resonant cavity with a lower resonant cavity in series, wherein the upper cavity is connected with a main pipeline through a branch pipeline; and the upper cavity is connected with the lower cavity through a pipeline or an opening hole on a clapboard. The double-cavity resonant type muffler is adopted to inhibit the pipeline noises, so that two noise elimination peak values can be generated in a low-frequency range, a favorable noise elimination effect is achieved, and the noises spread in the pipelines can be effectively inhibited. Meanwhile, the double-cavity resonant type muffler also fully utilizes an original idle space around the branch pipe, so that the space utilization ratio of the resonant type muffler is improved.

The invention relates to a steel face type composite wind pipe and a manufacturing method thereof, which relates to a wind pipe, in particular to a steel face type composite wind pipe used for building ventilation and an air-conditioning system, and the manufacturing method thereof. The invention provides the steel face type composite wind pipe and the manufacturing method thereof that combine the advantages of the traditional galvanized iron sheet wind pipe and the composite wind pipe, not only have an anti-collision external surface layer, but also have an internal heat insulating layer with good heat preservation effect. The composite wind pipe is provided with a steel face type surface layer, an intermediate foam heat insulating layer and an internal protecting layer which are all bonded by glue. The manufacturing method comprises the following steps: first, a steel face type composite wind pipe plate is prepared, treated with pipe section division and cutting according to the requirements of the size specification, then bonded for molding after pipe section division and cutting, and connected, sealed and blocked.

The invention belongs to the technical field of a sound barrier acoustic member, and specifically relates to a cup-shaped noise reduction and sound absorption member of a sound barrier. The cup-shaped noise reduction and sound absorption member is composed of a plurality of cup-shaped noise reduction and sound absorption member units, wherein a panel of each unit is composed of a plurality of rectangular arrays and trapezoidal transverse bars; each rectangular array is composed of a plurality of uniformly distributed reflector cups with a paraboloid-shaped acoustic construction; diffraction holes are formed in the bottom of each reflector cup; a rectangular connecting groove is respectively arranged in the longitudinal center on the upper surface and the lower surface of a back plate of each unit; the connecting groove and the rectangular connecting grooves of other sound absorption member units in the same position form a square cavity during installation, wherein a square steel pipe is embedded in the cavity as a connecting piece for clamping two adjacent cup-shaped noise reduction and sound absorption member units; a sound insulation plate is mounted in a tubular cavity which is formed by connecting the panel and the back plate; support frames are arranged on the transverse bars inside the cavity; and spaces divided by the support frame are filled with sound absorption wools and gauzes. The cup-shaped noise reduction and sound absorption member has stronger sound absorption ability, and the low-frequency sound absorption ability is improved.

The invention relates to brazing filler metal for connecting copper and stainless steel, application of the brazing filler metal and a method for welding a silencer and belongs to the field of brazing filler metal and silencer welding methods. The brazing filler metal comprises, by weight, 26-34 percent of Cu, 34-35 percent of Ag, 5-8 percent of Co, 2-4.5 percent of Li, 1-1.5 percent of Sn, 0.2-1.8 percent of Ni, 1.8-2 percent of B, 0.5-1.3 percent of Mn, 0.1-1.4 percent of Si, 0.03-0.16 percent of mischmetal and the balance of Zn. The mischmetal is composed of La and Pr, the mass ratio of La and Pr is equal to the mass ratio of Cu and Ag. When the brazing filler metal for connecting the copper and the stainless steel is applied to welding of the silencer, flames are utilized for welding, the requirement for welding is met, meanwhile, welding efficiency is high, production cost is low, a noise reduction effect after the silencer is welded is good, and the service life of the silencer is prolonged.