Magnesium alloy integrally cast sound box and manufacture method thereof
Technical field:
The present invention relates to a kind of audio amplifier, particularly a kind of magnesium alloy integrally cast sound box and manufacture method thereof belong to the assembly of stereo set.
Background technology:
For a long time, the sound box bodies material therefor is based on timber and goods thereof always, and timber can directly be made sheet material or make wood chip and be bonded into sheet material, i.e. MDF (MDF).Timber-work has advantages such as intensity height, light weight, resonance be better, therefore, the senior audio amplifier tonequality excellence of high-quality timber manufacturing, costs an arm and a leg.Along with the progress of material technology, materials such as plastics, metal also are used for the manufacturing of sound box bodies gradually.
Senior audio amplifier has very high requirement to acoustic characteristic, so people utilize various means to improve tonequality.For example, reduce resonance and standing wave as far as possible, the sound wave phase place is controlled, utilize curved surface that sound wave is carried out diffuse reflection etc.Therefore, selection and the structural design to the audio amplifier material has very high requirement.
Though timber is the comparatively desirable natural material of sound box bodies, timber-work also has and much is difficult to the shortcoming that overcomes.For example, timber is bonded to one after must making sheet material, but the firm degree at adhesive bond position is difficult to long-term assurance; Timber-work is difficult to carry out bending, and in order to reduce plane reflection, some senior audio amplifiers add thermal flexure with timber-work, but this has caused very big stress, causes the audio amplifier cracking easily.Even dull and stereotyped, also can be because of the variation generation warping and cracking of air themperature and humidity, so some senior audio amplifier is indeformable in order to keep structure, at the inner support frame that adds of audio amplifier, framework has inhibition to the conduction of sound wave, and manufacturing process is very complicated.In addition, the variation of air themperature and humidity also has very big influence to the tonequality and the preservation of audio amplifier, as produces problems such as mouldy.The manufacturing process of MDF makes audio amplifier continuous release formaldehyde in long-term use human body to be produced harm.
Though plastics have good mouldability, its rigidity is too low and tonequality is sent out extremely.The aluminium alloy audio amplifier then causes resonance easily because of rigidity is very good, makes the sound field energy loss.The proportion of aluminium alloy is far longer than timber, in order to reduce resonance, the audio amplifier wall must have certain thickness, therefore makes that the overall weight of audio amplifier is excessive, and existing metallic sound box body structure division generally connects with bolt by two assemblys with upper-part.
Summary of the invention:
The objective of the invention is at above-mentioned the deficiencies in the prior art, and provide a kind of rational in infrastructure for fields such as high fidelity sound system for electrical teaching, sound insulation property is good, audio amplifier efficient height, and manufacture method simply has the magnesium alloy integrally cast sound box and the manufacture method thereof of high tone quality effect.
The anti-acoustic pressure impact capacity of this integrally cast sound box is strong, and density is than the density height of wooden sound enclosure body, and sound insulation property is good, and the short circuit that causes is little, has improved the efficient of audio amplifier.Because the sound box structure is monoblock cast, there is not seam, thereby resonance that can the recurring structure seam crossing.Sound box can be cast into various labyrinths and curved surface, thereby can obtain to try to achieve the high tone quality effect.And very low density and the modulus of elasticity of relative other metal of magnesium alloy makes magnesium alloy have good damping vibration attenuation effect.This all makes magnesium alloy become desirable sound box material.The density of pure magnesium is 1.78g/cm
3, be the lightest in the practicability metal material, therefore make the generation that sound box bodies can further reduce resonance according to improving tonequality requirement increase wall thickness with magnesium and magnesium alloy.
For achieving the above object, the present invention designs rational sound box structure by acoustic design.In air or under the protective atmosphere; the magnesium alloy of pure magnesium or heterogeneity and modulus of elasticity and damping coefficient is melted in smelting furnace; by casting techniques such as sand casting, die cast, model casting, compression casting, semi-solid-state shapings, be cast as definite shape, wall thickness is certain or transformable whole sound box.Casting core can adopt reel, metal-cored, wax core etc.
The pure magnesium of the material that is adopted is generally pure magnesium; Magnesium alloy is Mg-X (X=Ni, Zr, Al, Cu, Li, Mn, Si, Ca, Ti, V, Be, Fe, Zn, Cr, Nb, Hf, Ce, B, C, N, Sc, Ga, Ge, Sr, Mo, Ag, Au, In, Sn, Bi an etc.) series alloy, and pure magnesium and alloy thereof have low density and good damping performance.
About the sound box design, the sound box bottom surface is generally the plane, removes the bottom surface lateral wall and all can be designed to plane or cambered surface, and audio amplifier inwall respective design becomes plane or cambered surface, perhaps face of a polyhedron.One side or many sides outer wall can also be designed to the plane, and inwall is designed to cambered surface or face of a polyhedron.The thickness of each sidewall of sound box can be for identical or different.The wall thickness of every side can be for identical or different.Therefore, even audio amplifier is parallelepiped or trapezoidal hexahedron, audio amplifier inside still can be designed according to different diffuse reflection modes.The cambered surface of audio amplifier outer wall and inwall can be disc or ellipsoid, radius of curvature from 20mm to infinitely great (plane).Magnesium alloy integrally cast sound box can also can be designed to audio amplifier special-shaped audio amplifier according to placing the environment needs.
Sound box inside can be for hollow entirely, also can design the one or more sound wave paraphase holes or the phase-reversing tube that go deep into audio amplifier inside from front panel or rear board, phase-reversing tube length is 0~3/4 of front and back inwall spacing from inwall, can be according to the tonequality requirement, needing in front to design with the casing metal on plate or the rear board according to audio frequency phase is one or more semiclapboards of same integral body, and dividing plate length is 0~4/5 of front and back inwall spacing from inwall.Open loud speaker installing hole, binding post hole, air phase place hole or phase-reversing tube etc. on the sound box.The sand casting process scheme can adopt loose pattern moulding, machine molding, the moulding of digging sand, the moulding of the cover plate centre of form etc.Select suitable casting pouring position.Audio amplifier front panel (be face wall, loud speaker is laid panel) generally adopts pouring position downward, and the pouring position of audio amplifier rear board (binding post is laid panel) upwards.Die joint is near position audio amplifier rear board bottom generally.
According to the quantity of core, locate mode, down core order, core print shape and size, make things convenient for molding, determine technological parameter: machine-finish allowance, pattern draft, the curving of castings and shrinkage.Determine shape, size, and the layout in sand mold etc. of running gate system, rising head, chill.
Running gate system can be according to sound box size and weight, adopts and withstand that formula running gate system, die joint are pouring-in, bottom gating, step gating system etc.The appropriate design ingate makes molten metal enter die cavity easily, does not hinder foundry goods to shrink simultaneously.Appropriate design rising head position prevents that as far as possible foundry goods from producing shrinkage cavity, defective such as loose.The sound box that casting is good obtains loud speaker, dust cover, pin pin location hole through machining.Location hole can be straight hole or screw.
The goods that casting is obtained carry out the surface finish processing.Magnesium and Mg alloy surface are easy to corrosion, and the audio amplifier outer wall can produce tiny casting flaw in casting process, but outer surface is polished or played putty.Utilize methods such as plating, face coat, hot-spraying coating, diffusion coating, ion injection, surface by micro-arc oxidation, laser surface alloying, brushing protective paint that audio amplifier inwall, outer wall are carried out preservative treatment; these processing methods can make the audio amplifier surface obtain metal-like extremely attractive in appearance, perhaps brush versicolor piano lacquer and make audio amplifier attractive in appearance.
Casing is installed high, medium and low band loudspeaker of one or more high-quality and audio electronics frequency divider as required.Inner shop sound-absorbing material as pitch, sponge, foam, paper etc., promptly can be made into the magnesium alloy integrally cast sound box with high tone quality.
Except sound box, for the bookshelf-type audio amplifier, supporting audio amplifier frame also can utilize magnesium alloy to carry out monoblock cast.
Beneficial effect of the present invention: utilize magnesium alloy to carry out the monoblock cast of sound box, can obtain almost arbitrary shape, size, baroque jointless sound box easily, therefore can control the diffuse reflection mode of sound wave in the casing, suppress the generation of resonance and standing wave, thereby obtain the audio amplifier of desirable acoustic characteristic.For example the audio amplifier sidewall is made the diffuse reflection cambered surface of certain radian.Utilize this sound box basic near theoretic desirability casing-pure rigid body, the tiny casting flaw of audio amplifier inner surface helps the diffuse reflection of sound wave.Therefore, this audio amplifier has advantages such as effective inhibition audio frequency side leaks, resonance is little, sound insulation is good, tonequality is more purer than wooden acoustic box, nature, fidelity are good, has eliminated the distinctive standing wave of wooden acoustic box, false bass, leakage shortcomings such as (low cut are excessive) substantially.The panel of pure magnesium audio amplifier has the texture attractive in appearance of metal, and the manufacture craft of magnesium and magnesium alloy audio amplifier integrally cast sound box is simple, and cost reduces.The technology features of magnesium alloy integrally cast sound box body is: remove electric elements such as loud speaker, frequency divider, binding post, and outside the dust cover, pin pin etc., the structure division of sound box bodies is for to carry out monoblock cast with pure magnesium or magnesium alloy.
Description of drawings:
Fig. 1 is the two frequency division bookshelf audio amplifier schematic diagrames of sidewall cambered surface of the present invention.
Fig. 2 is a sidewall cambered surface three frequency division abnormity audio amplifier schematic diagram of the present invention.
Fig. 3 is a concrete structure schematic diagram of the present utility model.
Embodiment
The concrete scope of used magnesium of the present invention and magnesium alloy materials:
Pure Mg: purity range: 99.99%~99.9% (percentage by weight).
Magnesium alloy: Mg-X series alloy, X=Ni, Zr, Al, Cu, Li, Mn, Si, Ca, Ti, V, Be, Fe, Zn, Cr, Nb, Hf, Ce, Co, La, B, C, N, Sc, Ga, Ge, Sr, Mo, Ag, Au, In, Sn, Bi, rare earth element Re, and wherein any one or multiple element and Mg combination are formed binary, ternary or complex magnesium alloy, and the content of every kind of alloying element all can change in the scope of 0.001~99% (percentage by weight).
Sound box is given an example with the magnesium alloy composition:
Mg-(0.1~2.0%)Zr;
Mg-(0.1~50.0%)Ni;
Mg-(0.1~10.0%)Al-(0.1~10.0%)Zn;
Mg-(0.1~20.0%)Ni-(0.1~5.0%)Zr;
Mg-(0.1~20.0%)Cu-(0.1~5.0%)Mn;
Mg-(0.1~20.0%)Ni-(0.1~5.0%)Nb;
Above-mentioned Mg composition is a surplus.
Embodiment one
With reference to accompanying drawing 1, this example has designed a kind of front wooden partition, two side, roof and has been cambered surface, and lower wall and rear wall are the magnesium alloy integrally cast bookshelf-type sound box bodies on plane.This casing is the two frequency division bookshelf audio amplifiers of sidewall cambered surface, the scope of each wall thickness does not wait from 5mm to 50mm, the thickness maximum of front wooden partition, the width of antetheca and height are greater than the width and the height of rear wall, audio amplifier is 2 frequency divisions, top is the tweeter perforate, and tweeter can adopt high-quality cortina, the titanium metal film that is about 1 inch, perhaps tweeter such as aluminum alloy thin belt high pitch; The middle part is the medium and low frequency speaker aperture, can adopt 5 inches to 10 inches high-quality medium and low frequency loud speaker; The bottom is the sound wave phase-reversing tube, and phase-reversing tube length is about 1/2 to 2/3 of audio amplifier internal depth.Front panel has 4 face shields and fixedly uses aperture.4 threaded pin pin fixing holes are arranged at the audio amplifier bottom.As shown in Figure 1.The audio amplifier front panel adopts pouring position downward.
Embodiment two
With reference to Fig. 2, this example has designed a kind of front wooden partition, two side, roof and rear wall and has been cambered surface, and lower wall is the magnesium alloy integrally cast sound box body on plane.Sound box bodies adopts the arc transition design according to the loud speaker size from top to bottom.Audio amplifier is a three frequency division, and top is tweeter, and the middle part is a mid frequency ludspeaker, and the bottom is a woofer.Tweeter can adopt high-quality cortina, the titanium alloy film that is about 1 inch, perhaps tweeter such as aluminum alloy thin belt high pitch; Mid frequency ludspeaker can adopt 5 inches to 10 inches loud speaker; Woofer can adopt 8 inches to 18 inches loud speaker, and the both sides, bottom are 2 sound wave paraphase holes.The scope of each position wall thickness does not wait from 5mm to 100mm.Can cast out 4 on the audio amplifier bottom surface and fall terraced steps, be used for contacting with ground as the audio amplifier pin.As shown in Figure 2.
Concrete structure is shown in Fig. 1,2 and 3, magnesium alloy integrally cast sound box, comprise sound box bodies 1, install in the sound box bodies 1 tweeter 10, in/woofer 11 and Active crossover device 7, and by lead connection binding post 8, its inwall also is provided with sound absorbing layer 9, and described sound box bodies 1 is the magnesium alloy integrally cast structure, and the top of sound box bodies 1 is provided with tweeter hole 3; During the middle part is provided with/woofer hole 2; The bottom is provided with sound wave paraphase hole 5, or gos deep into the phase-reversing tube of box house.This sound box bodies 1 also is shaped on binding post hole 4 and audio amplifier pin 6.
The audio amplifier front panel adopts pouring position downward.
The foregoing description one or embodiment two, the concrete weight % of the magnesium alloy composition that is adopted:
Mg-0.1%Zr or Mg-0.1%Ni or Mg-0.1%Al-0.1%Zn or Mg-0.1%Ni-0.1%Zr or Mg-0.1%Cu-0.1%Mn or Mg-0.1%Ni-0.1%Nb, above-mentioned Mg composition is a surplus;
Mg-2.0%Zr or Mg-50.0%Ni or Mg-10.0%Al-10.0%Zn or Mg-20.0%Ni-5.0%Zr or Mg-20.0%Cu-5.0%Mn or Mg-20.0%Ni-5.0%Nb, above-mentioned Mg composition is a surplus;
Mg-1%Zr or Mg-20%) Ni or Mg-5%Al-4%Zn or Mg-8%Ni-3%Zr or Mg-9%Cu-2%Mn or Mg-12%Ni-4%Nb, above-mentioned Mg composition is a surplus;
Mg-0.15%Zr or Mg-10%Ni or Mg-9%Al-2%Zn or Mg-12%Ni-3.5%Zr or Mg-16%Cu-1%1Mn or Mg-5%Ni-1%Nb, above-mentioned Mg composition is a surplus.
The sound box of the foregoing description one and embodiment two preparations also need carry out preservative treatment and japanning.