CN207909500U - A kind of muffler of automatic adjustment magnetorheological damping - Google Patents

Abstract

The utility model is related to exhaust noise silencing apparatus fields, and in particular to a kind of muffler of automatic adjustment magnetorheological damping.Including hollow cylinder, air inlet pipe and an air outlet pipe is equipped with along cylinder both ends；Cylinder includes shell, felt and perforated plate；Cylinder is divided into the first cavity, the second cavity and third cavity along vertical tubular axis direction by left clapboard and right clapboard in cylinder, air inlet pipe is communicated with the first cavity, and escape pipe is communicated with third cavity；Left clapboard is equipped with the shaft coaxial with cylinder, extend into the shaft of the first cavity and is equipped with sound-absorbing blade, and sound-absorbing blade is bonded by piezoelectric chip and metal substrate, and the shaft for extending into the second cavity is equipped with damping unit.Air-flow, which blows on sound-absorbing blade to generate, to be transformed into mechanical energy by the kinetic energy of air-flow and utilizes the piezoelectric effect active sound-absorbing of piezoelectric chip.Advantage and characteristic：The kinetic energy of air-flow is transformed into mechanical energy using sound-absorbing blade, acoustical absorptivity is strong, and absorption band is wide；The piezoelectric effect self-powered of sound-absorbing blade is utilized to damping unit, is not necessarily to external power, is reduced cost.

Description

A kind of muffler of automatic adjustment magnetorheological damping

Technical field

The utility model is related to exhaust noise silencing apparatus fields, and in particular to it is a kind of automatic adjustment magnetorheological damping exhaust disappear Sound device.

Background technology

Exhaust silencer be prevent sound transmission and allow air-flow by a kind of device, be eliminate air power noise Important measures.Exhaust silencer be mounted in air powered equipment (such as air blower, air compressor machine, boiler exhaust mouth, generator, The larger equipment of the exhaust outlet noises such as water pump) exhaust system in reduction noise device.There are many type of exhaust silencer, It is developed according to anti-, spray, resistance composite sound damping principle, mainly there is micropore jet and dilatation sound absorption.

In the prior art, the exhaust noise silencing effect of exhaust silencer is not ideal enough, and reason is：1. based on micropore jet Noise reduction method has the intrinsic frequency of oneself, the sound wave of certain frequencies only near mesh intrinsic frequency due to each hole Could be by mesh, therefore acoustic absorptivity is low, absorption band is narrow, and not easy to control；2. the sound-absorbing method based on impedance matching is to low The effect of frequency is good and high-frequency effect is poor.

Invention content

For the problems of in terms of existing muffler noise reduction, the utility model proposes a kind of automatic adjustment magnetic currents The muffler of variable damping, the embodiment that the utility model uses are：Including hollow cylinder, along cylinder one end off-axis The position of line is equipped with air inlet pipe, and the escape pipe that left end is cone is equipped with along the position of cylinder other end axis；Cylinder includes shell Body, felt and perforated plate are provided with several stomatas on perforated plate；By left clapboard and right clapboard along vertical tubular axis direction in cylinder Cylinder is divided into the first cavity, the second cavity and third cavity, air inlet pipe is communicated with the first cavity, escape pipe and third cavity It communicates；Left recirculation hole and right recirculation hole are provided on left clapboard and right clapboard in uniform way；Left clapboard is equipped with turn coaxial with cylinder Axis, the axis platform end face for extending into the shaft of the first cavity are equipped with sound-absorbing blade by screw, extend into the second cavity in uniform way Shaft be equipped with damping unit；Sound-absorbing blade is bonded by piezoelectric chip and metal substrate；Damping unit includes and cylinder Coaxial cylinder, the coil being installed in cylinder, the left pole being disposed in parallel in cylinder between left clapboard and right clapboard and right pole, Be located between left pole and right pole every magnetic rubber ring；Left clapboard, cylinder, right clapboard are fixed as one, left pole and right pole composition one A cylinder, inside form a cavity；Rotor is arranged in cavity and is set in shaft by key, is opened on the arc surface of rotor It is stepped tooth to have external tooth, external tooth, be equipped on left pole and right pole inner wall with the matched left inside tooth of external tooth and right internal tooth, external tooth with There are gaps between cog in left inside tooth and the right side；Gap between Zuo Ji, right pole and rotor is full of magnetorheological fluid, by the sealing of left and right two Circle is sealed, and bearing is equipped between shaft and left pole and right pole.

In the utility model, to improve the absorbing sound and lowering noise ability of sound-absorbing blade, sound-absorbing blade is set on the thin axis of shaft, And be connected by screw with axis platform end face, and with axial direction at certain angle of inclination beta (similar blade of electric fan inclination angle), sound-absorbing leaf Piece inclination angle is β=110 °, and sound-absorbing blade is the iridescent type structure of bending, and the radius of curvature of piezoelectric chip is less than metal substrate Radius of curvature, piezoelectric chip thickness are the PZT4 of 0.15~0.3mm, and metal substrate is beryllium-bronze, metal substrate and piezoelectric chip The ratio between thickness be 1~2.5, the absorbing sound and lowering noise ability of sound-absorbing blade is stronger at this time.

After air-flow enters the first cavity by air inlet pipe, air-flow generates aerodynamic force drive shaft when blowing to sound-absorbing blade and turns Dynamic, shaft rotation drives rotor to rotate synchronously, and the kinetic energy of air-flow is transformed into mechanical energy, makes the sound of various band noises in air-flow Power substantially reduces, and noise greatly weakens；When not having electric current in coil, magnetorheological fluid is Newton fluids, rotor and magnetic current Become the resistance very little between liquid, when having electric current to have magnetic field in coil, magnetorheological fluid then shows high viscosity, lazy flow Bingham bulk properties, the damping force between rotor and magnetorheological fluid become larger, and the size of damping force is controlled by size of current.

While air-flow blows to sound-absorbing blade, the vibration of sound wave causes the piezoelectric effect of piezoelectric chip, piezoelectric chip stress Charge is generated, charge is stored by storage circuit, is then applied on the coil of damping unit；By the positive piezoelectricity of piezoelectric chip Effect is it is found that the quantity of electric charge that generates under pressure of piezoelectric chip is directly proportional to pressure size.Therefore, it is applied to damping unit Coil on the charge value that is generated by piezoelectric chip of size of current control, when pneumatic noise vibration force is big, piezo crystals The quantity of electric charge that piece generates is with regard to big, therefore the electric current being applied on damping unit coil is with regard to big.The change of electric current can draw in coil The change of magnetizing field size, the change in magnetic field is so that the mechanical property of magnetorheological fluid changes, so that damping unit turns Sub- damping force is also changed, to realize the intelligent control to noise.

The kinetic energy of air-flow is transformed into mechanical energy by noise by sound-absorbing blade in air-flow, reduces a part of noise, while profit With piezoelectric effect active absorption low-frequency sound wave, perforated plate and felt collective effect Passive intake medium-high frequency sound wave are then relied on, is had Effect ground absorbs the noise of various frequency bands.

Advantage and characteristic：1) kinetic energy of air-flow is transformed into mechanical energy using sound-absorbing blade, reduces the sound work(of various frequency bands Rate, absorption band are wide；2) the piezoelectric effect self-powered that sound-absorbing blade is utilized to damping unit, is not necessarily to external power, reduces cost.

Description of the drawings

Fig. 1 is a kind of knot of the muffler of automatic adjustment magnetorheological damping in one preferred embodiment of the utility model Structure schematic diagram；

Fig. 2 is sound-absorbing blade and rotating shaft assembling structure schematic diagram in one preferred embodiment of the utility model；

Specific implementation mode

A kind of muffler of automatic adjustment magnetorheological damping, including hollow cylinder V, along the one end cylinder V off-axis The position of line is equipped with air inlet pipe a, and the escape pipe p that left end is cone p1 is equipped with along the position of cylinder V other end axis；Cylinder V Including shell b, felt c and perforated plate d, several stomata d1 are provided on perforated plate d；By left clapboard g and the edges right clapboard m in cylinder V Cylinder V is divided into the first cavity A, the second cavity B and third cavity C, air inlet pipe a and the first chamber by vertical cylinder V axis directions Body A is communicated, and escape pipe p is communicated with third cavity C；Left recirculation hole g1 and right circulation are provided on left clapboard g and right clapboard m in uniform way Hole m1；Left clapboard g is equipped with the shaft t coaxial with cylinder V, and the end faces axis platform t2 for extending into the shaft t of the first cavity A pass through spiral shell Nail is equipped with sound-absorbing blade E in uniform way, and the shaft t for extending into the second cavity B is equipped with damping unit Y；Sound-absorbing blade E is by piezoelectricity Chip e1 and metal substrate e2 are bonded；Damping unit Y includes the cylinder j coaxial with cylinder V, the line being installed in cylinder j It is disposed in parallel in left pole f and right pole n between left clapboard g and right clapboard m in circle k, cylinder j, is located between left pole f and right pole n Every magnetic rubber ring i, magnetorheological fluid h；Left clapboard g, cylinder j, right clapboard m are fixed as one, and left pole f and right pole n form one Cylinder, inside form a cavity；Rotor s is arranged in cavity and is set on shaft t by key u, on the arc surface of rotor s Be provided with external tooth s1, external tooth s1 is stepped tooth, be equipped on left pole f and right pole n inner walls with the matched left inside tooth f1 of external tooth s1 and There are gaps between right internal tooth n1, external tooth s1 and left inside tooth f1 and right internal tooth n1；Gap between left pole f, right pole n and rotor s is filled Full magnetorheological fluid h is sealed by the two sealing ring q in left and right, bearing r is equipped between shaft t and left pole f and right pole n.

In the utility model, to improve the absorbing sound and lowering noise ability of sound-absorbing blade, sound-absorbing blade E is set in the thin axis of shaft t It on t1, and is connected by screw with the end faces axis platform t2, and at certain angle of inclination beta, (similar blade of electric fan tilts with axial direction Angle), the inclinations angle sound-absorbing blade E are β=110 °, and sound-absorbing blade E is the iridescent type structure of bending, the radius of curvature of piezoelectric chip e1 Less than the radius of curvature of metal substrate e2, piezoelectric chip e1 thickness is the PZT4 of 0.15~0.3mm, and metal substrate e2 is that beryllium is green Copper, the ratio between thickness of metal substrate e2 and piezoelectric chip e1 are 1~2.5, and the absorbing sound and lowering noise ability of sound-absorbing blade E is stronger at this time.

After air-flow enters the first cavity A by air inlet pipe a, air-flow generates aerodynamic force drive shaft t when blowing to sound-absorbing blade E Rotation, shaft t rotations drive rotor s to rotate synchronously, and when not having electric current in coil k, magnetorheological fluid h is Newton fluids, is turned Resistance very little between sub- s and magnetorheological fluid h, when thering is electric current to have magnetic field in coil k, magnetorheological fluid h then show high viscosity, The Bingham bulk properties of lazy flow, the damping force between rotor s and magnetorheological fluid h become larger, and the size of damping force is by electric current Size controls.

While air-flow blows to sound-absorbing blade E, the vibration of sound wave causes the piezoelectric effect of piezoelectric chip e1, piezoelectric chip e1 Stress generates charge, and charge is stored by storage circuit, is then applied on the coil k of damping unit Y；By piezoelectric chip e1 Direct piezoelectric effect it is found that the quantities of electric charge that generate under pressure of piezoelectric chip e1 are directly proportional to pressure size.Therefore, apply Size of current on to the coil k of damping unit Y is controlled by the charge value that piezoelectric chip e1 is generated, when pneumatic noise vibration force is big When, the quantity of electric charge that piezoelectric chip e1 is generated is with regard to big, therefore the electric current being applied on damping unit Y coils k is with regard to big.Coil The change of electric current can cause the change of magnetic field size, the change in magnetic field that the mechanical property of magnetorheological fluid h is changed in k, So that damping unit Y rotor s damping forces are also changed, to realize the intelligent control to outside noise.

The general flow velocity of air-flow in muffler is fast, and pneumatic noise is high, and the kinetic energy of air-flow is transformed into machine by sound-absorbing blade E The acoustical power of various frequency bands has reduced in noise after tool energy, therefore noise greatly weakens, while being imitated by the piezoelectricity of piezoelectric chip e1 Answer, by acoustic energy be converted into electric energy can active absorption low-frequency sound wave, then rely on perforated plate d and felt c collective effect Passive intakes Medium-high frequency sound wave, effectively absorbs residual noise.

Claims (1)

1. a kind of muffler of automatic adjustment magnetorheological damping, it is characterised in that：Including hollow cylinder, along cylinder one end The position of off-axis is equipped with air inlet pipe, and the escape pipe that left end is cone is equipped with along the position of cylinder other end axis；Cylinder Including shell, felt and perforated plate, several stomatas are provided on perforated plate；By left clapboard and right clapboard along vertical drum shaft in cylinder Cylinder is divided into the first cavity, the second cavity and third cavity by line direction, and air inlet pipe is communicated with the first cavity, escape pipe and Three cavitys communicate；Left recirculation hole and right recirculation hole are provided on left clapboard and right clapboard in uniform way；Left clapboard is equipped with same with cylinder The shaft of axis, the axis platform end face for extending into the shaft of the first cavity are equipped with sound-absorbing blade by screw in uniform way, extend into The shaft of two cavitys is equipped with damping unit；Sound-absorbing blade is bonded by piezoelectric chip and metal substrate；Damping unit includes Coaxial cylinder, the coil being installed in cylinder, the left pole being disposed in parallel in cylinder between left clapboard and right clapboard with cylinder And right pole, be located between left pole and right pole every magnetic rubber ring；Left clapboard, cylinder, right clapboard are fixed as one, left pole and right pole A cylinder is formed, inside forms a cavity；Rotor is arranged in cavity and is set in shaft by key, the circular arc of rotor External tooth is provided on face, external tooth is stepped tooth, be equipped on left pole and right pole inner wall with the matched left inside tooth of external tooth and right internal tooth, There are gaps between cog in left inside tooth and the right side for external tooth；Gap between Zuo Ji, right pole and rotor is full of magnetorheological fluid, by left and right two A sealing ring is sealed, and bearing is equipped between shaft and left pole and right pole.