35results about How to "Improve sound absorption and noise reduction effect" patented technology

The invention discloses a combined type integrated box room and belongs to the technical field of movable rooms. The combined type integrated box room comprises a standard box body room, a main frame of the standard box body room comprises stand columns and beams, and the main frame is formed by welding rectangular tubes. Peripheral wall plates embedded into the main frame are fireproof plates, and a bottom plate is a fiber cement pressure plate. A top plate comprises an inner-layer fireproof plate which is horizontally laid and an outer-layer waterproof plate which is obliquely laid. The top beam of at least one side of the standard box body room is a gutter beam. The combined type integrated box room has the better bearing capacity, the fireproof performance, the heat insulation property and the sound absorption and noise lowering effect, installation is convenient, the plate shape is beautiful, construction operation is simpler and faster, and working efficiency is improved.

The invention relates to the field of kitchen appliances and aims at providing a low noise and large suction range hood. The low noise and large suction range hood comprises a main case provided with two inner side plates and a rear through hole located in the rear end, an air duct arranged in the main case, a smoke collecting hood arranged at the lower end of the main case, and a check valve arranged at the upper end of the main case. The low noise and large suction range hood further comprises two parallel micro perforated plates provided with silencing small hole sets, and two sound absorbing and noise lowering plates; the two opposite side ends of the air duct are each provided with an air inlet; the two micro perforated plates are opposite to the two air inlets one to one; and the two micro perforated plates correspond to the two inner side plates one to one and each press one sound absorbing and noise lowering plate to be connected with the inner side of the corresponding inner side plate. The low noise and large suction range hood has the large air volume and air pressure strong suction performance and is low in noise.

The invention relates to sound absorbing cotton, in particular to nonwoven cloth sound absorbing cotton containing graphene. The nonwoven cloth sound absorbing cotton is composed of a top face layer, a back layer and a fiber cotton layer clamped between the top face layer and the back layer, the top face layer and the back layer are made of nonwoven cloth, and the nonwoven cloth is formed by, by weight, 100 parts of isotactic polypropylene, 5-7 parts of vinyl acetate, 2-3 parts of acrylic acid-2-hydroxy propyl ester, 1-2 parts of isocyanate, 4-5 parts of silica, 2-3 parts of sodium tripolyphosphate, 12-15 parts of epoxidized soybean oil, 1-2 parts of graphene, 1-2 parts of cetyl trimethyl ammonium bromide, 3-4 parts of radix isatidis, 1-2 parts of dyer woad leaf, 2-3 parts of houttuynia cordata and 4-5 parts of auxiliary through a melt-blowing method. The nonwoven cloth which is excellent in mechanical performance and dense in cloth quality is taken as an outer layer material, so that leakage of interlayer fiber cotton is effectively prevented, effect of environment friendliness and safety, heat resistance and flame retardancy, sound absorbing and denoising and the like is realized, and the nonwoven cloth sound absorbing cotton is wide in application prospect.

The invention relates to a nonwoven material, in particular to a wear-resistant heat-insulating nonwoven material for sound absorbing cotton. The nonwoven material is made from, by weight, 100 parts of isotatic polypropylene, 2-3 parts of nano-silica, 1-2 parts of hollow glass microspheres, 1-2 parts of rutile titanium dioxide, 7-9 parts of smoke sheet rubber, 12-15 parts of dimethyl fumarate, 2-3 parts of calcium stearate, 6-9 parts of zeolite, 3-4 parts of diatomite, 8-10 parts of activated carbon, 2-3 parts of humifuse euphorbia herb, 1-2 parts of scutellaria baicalensis, 1-2 parts of pueraria and 4-5 parts of auxiliaries. The nano-silica, the hollow glass microspheres and the like are contained in the nonwoven material, so that mechanical properties of the material are enhanced, and the nonwoven material is flexible, wear resistant, resistant to stretching and impact, heat-insulating and breathable; sound absorption and noise reduction effect of the material is improved by the aid of the zeolite, the diatomite, the activated carbon, Chinese medicinal herb fibers and the like; after being subjected to multi-layer superposition, the nonwoven material can be made into the sound absorbing cotton, and the nonwoven material is simple in process and broad in application prospect.

The invention relates to a non-woven fabric material, and specifically relates to a capsaicin-containing non-woven fabric material for sound-absorbing cotton. The non-woven fabric material is prepared from the following raw materials in parts by weight: 100 parts of isotatic polypropylene, 1-2 parts of anti-oxidant 1010, 2-3 parts of toluene diisocyanate, 1-2 parts of fatty alcohol polyoxyethylene ether, 2-3 parts of nanometer calcium carbonate, 1-2 parts of capsaicin, 6-9 parts of double fourteen-carbon alcohol ester, 12-15 parts of diisobutyl phthalate, 1-2 parts of eggshell powder, 1-2 parts of aluminum sulfate, 2-3 parts of cortex mori, 1-2 parts of peucedanum praeruptorum, 1-2 parts of tussilago farfara and 4-5 parts of an auxiliary agent. The non-woven fabric material has the toughening and reinforcing effects and the sound-absorbing and noise-reducing effects because of contained raw materials such as nanometer calcium carbonate, eggshell powder, Chinese herbal medicine vegetable fibre and the like; additionally, the non-woven fabric material is prolonged in service life because of the insect-preventing bacterium-preventing efficacy possessed by capsaicin; and sound-absorbing cotton can be prepared by performing multilayer stacking on the non-woven fabric material, the technology is simple and the application potential is huge.

The invention relates to a non-woven sound absorption material, in particular to a hollow carbon ball-styrene-acrylic composite emulsion coated polypropylene-based non-woven sound absorption material for automotive interior trimming. The hollow carbon ball-styrene-acrylic composite emulsion coated polypropylene-based non-woven sound absorption material is prepared by, by weight, raw materials including 2-3 parts of polyvinyl acetal, 12-15 parts of ethylene-butylene copolymer, 22-26 parts of polypropylene, 3-4 parts of oxidized starch, 2-3 parts of ethylene glycol dimetacrylic acid ester, 1-2 parts of sodium alginate, 2-3 parts of silane coupling agent kh550, 3-5 parts of carbon nano-particles, 1-2 parts of antioxidant 1010, 12-15 parts of aluminium oxide of 400-600 meshes, 0.1-0.2 part of nano hollow carbon balls, 1-2 parts of nanometer silicon, 12-14 parts of styrene-acrylic emulsion with 8%-10% solid content and 1-2 parts of additive. The hollow carbon ball-styrene-acrylic composite emulsion coated polypropylene-based non-woven sound absorption material does not pollute the inside environment of an automobile, is flame-retardant and abrasion-resistant, meanwhile is easy to absorb and degrade and is a novel practical automotive sound absorption material.

The invention belongs to the technical field of building, and particularly relates to a fencing board having a noise reduction function and used for building construction. To solve the problems that an existing fencing board for the building construction has poor noise reduction effect and has no noise reduction function, the following scheme is put forward, the fencing board having the noise reduction function and used for the building construction comprises a base board, supporting boards are connected to the two ends of the top of the base board through bolts, a same cover board is connected to the tops of the two supporting boards through bolts, a same segregation board is connected between the cover board and the base board through bolts, four fixed pins are connected to the middle ofone side of the segregation board through bolts, and a same public benefit propaganda column is connected between the four fixed pins through bolts. According to the fencing board having the noise reduction function and used for the building construction, sound is absorbed by corrugated boards of wrinkle-shaped structures and a foam board when transmitted to the segregation board, so that the segregation board has good sound insulation and noise reduction effects, when the sound is transmitted to the interior of a shell, sound waves are refracted and absorbed in the shell, and the sound absorption and noise reduction effects of the fencing board are further improved.

The invention discloses a light high-strength sound barrier cement board for an expressway, and belongs to the technical field of expressway sound barriers. The light high-strength sound barrier cement board for the expressway comprises a front face mounting plate, a back face mounting plate, a light high-strength cement board and a plurality of silencing shells; a sound absorption cavity is formed between the back face mounting plate and the front face mounting plate; the light high-strength cement board is arranged in the sound absorption cavity; the plurality of silencing shells are arranged on the front face mounting plate to form a silencing shell array, each silencing shell is provided with a silencing cavity and a silencing inlet communicated with the silencing cavity, and the silencing inlet of each silencing shell deviates from the front face mounting plate; and a silencing dissipation space is formed between the outer surfaces of the plurality of silencing shells and the front face mounting plate. According to the light high-strength sound barrier cement board for the expressway, effective energy consumption reduction and sound attenuation are conducted on sound waves, sound absorption is conducted at the same time, the energy of the sound waves conducted to a sound barrier can be greatly reduced, and the sound absorption and attenuation effect is effectively improved.

The invention discloses a sound screen board and a sound barrier using the same. A sound screen board comprises a rectangular outer shell body and a sound absorbing body, wherein the rectangular outershell is composed of a panel, a back board, and a side board, and the sound absorbing bodyfillsthe interior of the outer shell body;in the assembly process of the sound screen board, the use of rivets is omitted, the appearance is more aesthetic, automatic continuous production can be realized, using of manpower is reduced, production efficiency is greatly improved, and finished products are decreased;in terms of using performance, the corrosion of riveting joints can be avoided, and the overall fixing strength can be ensured. In the assembly structure of the sound screen board, the top of the outer shell body is in the structural form of an upper flanging groove covering an upper clamping part, and an overlap joint slit is vertically formed, and a vertical upper clamping part is arrangedon the inner side of the lap joint slit for protection, so that rainwater does not enter into the outer shell body, thus the problemsof corrosion of the sound screen board and uneven filling caused by sinking of the sound absorbing body are avoided, the service life of the sound screen board is prolonged, and the sound absorption and noise reduction effects are further improved.A sound barrier has the using and producing advantages of the sound screen board.

The invention relates to a multi-frequency sound absorption type acoustic superstructure. The superstructure comprises a plurality of sound absorption units connected in sequence, wherein a cavity is formed in each sound absorption unit, the cavities in every two adjacent sound absorption units communicate with each other through an open hole, and a first open hole is further formed in the first sound absorption unit and communicates with the cavity in the sound absorption unit. The superstructure is advantaged in that the multiple sound absorption units are arranged, each sound absorption unit forms one Helmholtz resonant cavity through the cavity and the opening, each sound absorption unit is equivalent to one Helmholtz resonant cavity, multiple sets of absorption peaks can be generated by combining the cavities of the multiple different units, almost perfect sound absorption can be achieved for multiple sets of frequencies, and the sound absorption and noise reduction effects are improved.

The invention discloses a low noise local ventilator for the mine. The ventilator comprises a silence chamber and a fan body installed in the silence chamber, wherein the left and right sides of the silence chamber are oppositely provided with a silence current collector and a silence diffuser; the silence current collector is mainly composed of silencer structures and a built-in rectifying device; the silence diffuser is mainly composed of a silencer structure and a built-in diffusing device; each silencer structure includes an inner, a middle and an outer silencers of three concentric rings.The low noise local ventilator for the mine has the advantages that the silence current collector has the function of the original fan current collector while eliminating the noise in a fan inlet, the silence diffuser has the function of the original fan diffuser while eliminating noise in a fan outlet, and the silence chamber the noise radiated from the main body shell. The noise value radiatedfrom all directions of the fan is effectively reduced by the mine counter-rotating ventilator and the problem of high noise of the mine axial flow fan is successfully solved.

The invention provides a pad for a subway track. The mechanical performance of a pad body of the pad is greatly improved, the ratio of dynamic and static stiffness is less than 1.8, and the static stiffness change rate is less than 25%. Energy-absorbing groups with completely opposite height changes are arranged in an upper accommodating cavity and a lower accommodating cavity to ensure the stability of the structure of the pad. The energy-absorbing groups with the height change in the ladder form in the upper accommodating cavity are utilized to form different compression zones, so that the energy-absorbing groups of different heights have different static stiffness, the pad body has the step stiffness accordingly, and automatic adjustment of the static stiffness is achieved. The arrangement of a plurality of upper energy absorption zones increases the adjustment density of the static stiffness and makes the adjustment more precise. The surface area of auxiliary energy absorbing sheets is reduced by grooves to increase the deformability of the auxiliary energy absorbing sheets, so that the sheets can be better compressed and achieve a better buffering effect on the subway.

The invention discloses a noise-reducing and shock-absorbing solid tire and a preparation method thereof. Noise-reducing and shock-absorbing solid tires include a tire liner and tread rubber located on the outer circumference of the tire liner; the tire liner includes the following components: waste rubber, vulcanized reclaimed rubber, zinc oxide, stearic acid, accelerators, adhesives , shock-absorbing material; tread rubber includes the following components: waste rubber, zinc oxide, stearic acid, anti-aging agent, anti-fogging agent, Coumarone, noise-reducing material; the mass ratio of shock-absorbing material is 1:0.6‑0.9 : 0.3‑0.6 polyamide thermoplastic elastomer, SEBS thermoplastic elastomer and EPDM rubber; noise reduction materials include the following components: glass fiber, silicon carbide fiber, activated carbon fiber, expanded perlite, attapulgite and Acrylate emulsion; the noise-reducing and shock-absorbing solid tire of the present invention has an excellent shock-absorbing and noise-reducing effect, reduces the bumpy feeling and noise in the process of uneven ground formation, and enhances the advantages of user comfort.

The invention provides a pad for a subway track. The mechanical performance of a pad body of the pad is greatly improved, the ratio of dynamic and static stiffness is less than 1.8, and the static stiffness change rate is less than 25%. Energy-absorbing groups with completely opposite height changes are arranged in an upper accommodating cavity and a lower accommodating cavity to ensure the stability of the structure of the pad. The energy-absorbing groups with the height change in the ladder form in the upper accommodating cavity are utilized to form different compression zones, so that the energy-absorbing groups of different heights have different static stiffness, the pad body has the step stiffness accordingly, and automatic adjustment of the static stiffness is achieved. The arrangement of a plurality of upper energy absorption zones increases the adjustment density of the static stiffness and makes the adjustment more precise. The surface area of auxiliary energy absorbing sheets is reduced by grooves to increase the deformability of the auxiliary energy absorbing sheets, so that the sheets can be better compressed and achieve a better buffering effect on the subway.

The invention provides a wear-resistant and heat-insulated non-woven fabric material for sound absorption cotton. The non-woven fabric material is prepared from, by weight, 100 parts of isotatic polypropylene, 2-3 parts of nano-silicon dioxide, 1-2 parts of hollow glass microspheres, 1-2 parts of rutile-type titanium dioxide, 7-9 parts of smoke sheet rubber, 12-15 parts of dimethyl fumarate, 2-3 parts of calcium stearate, 6-9 parts of zeolite, 3-4 parts of diatomite, 8-10 parts of activated carbon, 2-3 parts of humifuse euphorbia herb, 1-2 parts of radix scutellariae, 1-2 parts of kudzuvine roots and 4-5 parts of auxiliaries. According to the wear-resistant and heat-insulated non-woven fabric material for the sound absorption cotton, due to the fact that the raw materials such as nano-silicon dioxide and the hollow glass microspheres are contained, the mechanical property of the material is enhanced, and the material achieves the flexibility, wear resistance, stretch resistance, impact resistance, heat insulation and air permeability; by adding the raw materials such as the zeolite, the diatomite, the activated carbon and Chinese herb plant fiber, the sound absorption and noise reduction effects of the material are improved. The sound absorption cotton can be made by stacking multiple layers of non-woven fabrics, the processes are simple, and the application range is wide.

The invention discloses a heat insulation coating, and belongs to the field of building coatings. The heat insulation coating aims at solving the problem that a heat insulation coating in the prior art is thick in coating layer and is unsuitable for a facing layer of a building external wall. The heat insulation coating is characterized by being prepared from low-density hollow glass microspheres,hydrophobic emulsion, a water repellent, nanosilicon dioxide, a foaming agent, an air entraining agent, elastic emulsion, a thickening agent and grapheme. The heat conductivity coefficient of the coating is lowered to 0.030 W / (m K), the coating can be used in cooperation with primer and a reflective heat insulation surface paint layer, a coating with the low thickness is scraped in batch, and theexcellent heat insulation effect can be obtained. The invention correspondingly discloses a preparing method for the heat insulation coating, the heat insulation coating prepared with the method is suitable for scraping in batch or spraying or napping construction, and has the advantages of being high in bonding strength, good in waterproof performance and excellent in anti-cracking and heat insulation performance. The invention also discloses a heat insulation system with the heat insulation coating, and the heat insulation system has the advantages that the heat insulation system can be used for a building external wall / internal wall, the heat insulation effect is good, and energy saving and environmental protection effects are achieved.

The invention relates to vehicle two-component sound absorbing material and a preparation method for the same. The vehicle two-component sound absorbing material is manufactured via mixture of EVA / PP blend fibers and PP fibers; the content of the EVA / PP blend fibers is 50% to 80%; the content of the PP fibers is 20% to 50%; and the content of EVA in the EVA / PP blend fibers is 10% to 30%. Compared with the prior art, sound absorbing and noise reduction effect can be improved; and the material can be easily decomposed, so environment can be protected.

The invention discloses a template machine for clothing. The template machine for clothing comprises a machine body and a working table, wherein the working table is positioned on the upper portion ofthe machine body; a heat-dissipation pipe is mounted on the inner wall of the machine body; a ventilating fan is mounted on one side of the upper portion of the machine body; a refrigerating pipe isarranged on the other side of the upper portion of the machine body; the ventilating fan communicates with the refrigerating pipe through the heat-dissipation pipe; a water-cooled tube is inlaid on the inner wall of the heat-dissipation pipe; the outer side of the bottom of the machine body is fixedly connected with a water-cooled heat sink; the water-cooled heat sink is connected with the water-cooled tube; a refrigerating plate is mounted in the refrigerating pipe; and one side of the outside of the refrigerating pipe is in clamped connection with a blowing fan. By arrangement of the blowingfan and the refrigerating pipe, the heat-dissipation property of the template machine is improved effectively, by arrangement of a U-shaped clamping column and a pressure lever, a clothing template is convenient to fix, convenient to assemble and disassemble and convenient to use, by arrangement of a noise-reduction interlayer, the noise-reduction property of the machine body is improved effectively, noise trouble and damage are avoided, and the template machine for clothing is suitable for being popularized and used widely.

The invention discloses a radial multidirectional dispersed sound-absorbing material, and belongs to the field of sound absorbing materials; according to the radial multidirectional dispersed sound-absorbing material, on one hand, sound waves are converted into the vibration force of slow vibration rods; under the vibration effect of the slow vibration rods, the slow vibration rods are in a radialshape, so the sound is transmitted into the sound-absorbing material along the continuously changing direction of the slow vibration rods, and through similarly breaking up the entirety into parts, the sound can be differentiated; further, the sound absorption and noise reduction effects of the sound-absorbing material are obviously improved. On the other hand, when the sound is transmitted to the slow vibration rods; sound propagation speed is reduced, the time of sound in the sound-absorbing material is prolonged, and furthermore, the effect of sound consumption is achieved, so that sound absorption effect is better; and meanwhile, the upward vibration amplitude of the slow vibration rods can be effectively increased by matching with the effect of a differentiation-assisting fixed ball,so that the differentiation range of the sound-absorbing material to the sound is larger, and the sound absorption effect of the sound-absorbing material is further improved.

The invention provides a noise reduction device of a refrigerator, and relates to the field of refrigerators. The noise reduction device of the refrigerator comprises a box body and an operating box.The inner bottom of the operating box is fixedly connected with a compressor. The right side of the compressor is provided with a sound absorbing plate. The outer surface of the sound absorbing plateis fixedly connected with sponge rubber. The right side wall of the operating box is fixedly connected with a fixed seat. The right side of the fixed seat is provided with a threaded groove. The threaded groove is internally connected with a mounting rod in a threaded mode. According to the noise reduction device of the refrigerator, by arranging the sound absorbing plate, the sponge rubber, a sealing pad and a semi-circular cover, the sound absorbing plate and the sponge rubber operate jointly, damping and heat isolating are achieved while the sound absorbing and noise reduction effects are improved, the sealing pad improves the sealing effect of structure connecting to reduce overflow of noise, and the semi-circular cover gathers and absorbs the noise; and by arranging a fixed sleeve, acold water pipe and a buffer pad, vibration of the noise is transmitted to water in the cold water pipe for absorbing buffer, and the buffer pad further conducts counteracting.

The invention relates to a preparation method of a super-strong sound insulation building decoration material. The preparation method comprises the following construction steps that A, a sound insulation metal layer is prepared; B, the interior of the sound insulation metal layer is coated with a sound insulation adhesive layer; C, a sound insulation fiber cloth layer is bound on the sound insulation adhesive layer; D, a sound insulation core layer is poured on the upper portion of the sound insulation fiber cloth layer; E, in the solidification process of the sound insulation core layer, a sound insulation plate layer is prepared; F, the upper surface of the sound insulation board layer is coated with a sound insulation viscous layer; G, a decorative layer is bound on the sound insulation adhesive layer in the step F; H, the lower surface of the sound insulation board layer is coated with a sound insulation viscous layer; and I, the lower surface of the sound insulation plate layer is bonded with the solidified sound insulation core layer through the sound insulation adhesive layer. The invention further relates to production equipment for preparing the super-strong sound insulation building decoration material. The preparation method is simple in step and high in efficiency; and the production equipment is simple in structure, convenient to operate and high in production efficiency, and the labor use cost is reduced.

The invention discloses a low-noise pneumatic tire assembly. An annular tire cavity is formed by the inner surface of a tread of a tire and a rim jointly. The low-noise pneumatic tire assembly is characterized in that energy dissipaters in a partition mode are arranged on the cross section of the annular tire cavity, the annular tire cavity is circumferentially divided into multiple sections through the energy dissipaters, the energy dissipaters are made of a porous sound absorption material, front and rear porous faces of the sound absorption material are arranged in the annular tire cavity,and the tire cavity resonance acoustic mode separation energy dissipaters are formed. The low-noise pneumatic tire assembly has the remarkable noise reduction performance and is light, economical anddurable.

The invention discloses a sound absorption fence for civil construction. The sound absorption fence comprises a base, a fixing frame and soil penetrating cones, wherein the soil penetrating cones are arranged on the lower side of the base at equal intervals, the fixing frame is arranged on the upper side of the base, a reflective sticker is arranged on the outer side of the fixing frame, a panel is arranged at the upper part of the fixing frame, a sound blocking arc plate is arranged on the upper side of the fixing frame, a cavity is integrally formed in the inner side of the sound blocking arc plate, a water spraying pipe is arranged on the upper side in the cavity, and spray heads are symmetrically arranged on the lower side of the water spraying pipe. By means of the sound blocking arc plate and the cavity, when the sound absorption fence for civil construction is used, the upper side of the fence effectively blocks noise through the sound blocking arc plate, the noise is prevented from being transmitted to the periphery of a construction site from the upper side of the fence, and the sound absorption and noise reduction effects are improved.

The invention discloses a bubble curtain / foam board composite noise reduction method for underwater sound absorption and noise reduction. The method comprises the following steps: enabling bubbles to move upwards between two opposite porous surfaces of two foam boards to form a bubble curtain, and realizing the combination of bubble curtain noise reduction and foam material noise reduction. By means of the porous surface of the foam board, bubbles can be continuously refined through collision of the foam board and the foam board in the bubble rising process, and therefore the sound absorption and noise reduction effects of the bubble curtain are further enhanced; and the foam plate can support the bubble curtain, the influence of airflow and water flow on the bubble curtain is weakened, and the noise reduction effect is stabilized.

The application relates to the field of decoration materials, and specifically discloses a sound-absorbing and noise-reducing interior decoration material and a preparation method thereof. A sound-absorbing and noise-reducing interior decoration material, prepared from the following raw materials in parts by weight: 30-50 parts of polyvinyl chloride resin; 7-12 parts of styrene-methylstyrene copolymer; 2-3.5 parts of reinforcing fiber ; Plasticizer 6~10 parts; Antioxidant 0.8~1.3 parts; Stabilizer 1.5~2 parts. The preparation method is as follows: mixing and stirring the raw materials in advance to obtain a mixture, and then kneading to obtain kneaded flakes, and then vulcanizing molding to obtain a sound-absorbing and noise-reducing interior decoration material, which has the ability to improve the impact resistance of polyvinyl chloride resin, The advantages of maintaining good sound absorption and noise reduction capabilities.

The invention discloses a broadband sound absorbing material and a sound absorbing device. The sound absorbing material comprises active carbon fiber three-dimensional fabric layers and a porous material layer, wherein at least two active carbon fiber three-dimensional fabric layers are formed; the porous material layer is formed between the two active carbon fiber three-dimensional fabric layers; the outer surface of each active carbon fiber three-dimensional fabric layer is coated with a nanometer fiber film; and the porous material layer is made of foamed aluminum or a cement-based porous composite material. According to the sound absorbing device, the sound absorbing material is fixedly arranged on a wall body through a connecting piece, the front end of the connecting piece is provided with a connecting device for fixing the broadband sound absorbing material, and the back end of the connecting piece is a cavity. The sound absorbing device disclosed by the invention can effectively meet the use requirements of expressway tunnels.

The invention relates to an automobile clutch housing, and belongs to the technical field of automobile parts. The invention aims to solve the technical issue that the usage effect and the service life cannot satisfy demands when a present automobile clutch housing is used. To solve the above technical issue, the technical scheme adopted by the invention is that the automobile clutch housing comprises a housing main body and a cavity in the housing main body, the cavity is provided with mounting holes, a locating pin hole and a weight reducing groove, a reinforcing column is disposed at the periphery of each mounting hole in housing main body, the inner wall of the housing main body is provided with a noise reduction layer, and the lower portion of the housing main body is provided with heat dissipating holes. The clutch housing is reasonable in structure, long in service life and high in work performance.