31results about How to "Effectively absorb noise" patented technology

The invention relates to a novel silent drain valve structure. The height of the novel silent drain valve structure can be freely adjusted according to mating height, and the novel silent drain valve structure is good in drain effect and can be fast replaced or maintained. The novel silent drain valve structure comprises a drain valve body, a drain base arranged below the drain valve body and used for being fixed to a toilet bowl water tank, and an overflow pipe connected with the drain base. A hollow drain connection base is arranged between the drain valve body and the drain base. A sealed air bag is arranged between the drain connection base and the drain base, connection nuts are arranged at the upper end and the lower end of the sealed air bag respectively, and the sealed air bag is connected with the drain connection base and the drain base through the two connection nuts. The drain connection base is provided with a guide sleeve with an opening, wherein the guide sleeve is arranged on the outer side of the circumference of the overflow pipe in a sleeved mode, can slide vertically along the overflow pipe and is fastened to the outer side of the overflow pipe by being locked by a butterfly nut.

The invention relates to a prestress concrete noise barrier sound absorption inserting plate for a high speed railway. The prestress concrete noise barrier sound absorption inserting plate for the high speed railway comprises a prefabricated concrete unit inserting plate and a sound absorption panel which are rectangular structural members; the sound absorption panel is connected with the prefabricated concrete unit inserting plate through a bolt; left and right sides of the prefabricated concrete unit inserting plate are provided with thickened rib columns, and the top and the bottom of the prefabricated concrete unit inserting plate are respectively provided with thickened rib beams; a groove is formed on the thickened rib beam at the bottom of the prefabricated concrete unit inserting plate; and horizontal and vertical prestress reinforcing steel bars are arranged in the prefabricated concrete unit inserting plate. The prestress concrete noise barrier sound absorption inserting plate for the high speed railway can effectively resist long-term action of pulse air load and natural typhoon load of the high speed railway of which the highest speed is 380 to 400 kilometers per hour, has good fatigue resistance performance, obvious lasting quality and remarkable noise-reducing effect; and the cost for manufacturing the prestress concrete noise barrier sound absorption inserting plate is low, and the prestress concrete noise barrier sound absorption inserting plate is convenient to install and exchange.

The invention provides an air conditioner indoor unit and a volute thereof. The volute comprises a front wall plate (1), a tongue (2), a straight tongue side plate (21) and an arc tongue side plate (22); the straight tongue side plate (21) is connected to one end of the tongue (2); the arc tongue side plate (22) is connected to the other end of the tongue (2). The straight tongue side plate (21) is provided with first silencing holes (3); a first silencing cavity (31) communicated with the first silencing hole (3) is arranged outside the straight tongue side plate (21); the arc tongue side plate (22) is provided with second silencing holes (4); a second silencing cavity (41) communicated with the second silencing hole (4) is arranged outside the arc tongue side plate (22); the tongue (2) is provided with third silencing holes (5); a third silencing cavity (51) communicated with the third silencing holes (5) is arranged outside the tongue (2). The volute has the advantages that a peak value of low fan rotational noise is effectively reduced and volute noise is effectively reduced accordingly.

The invention particularly relates to a manufacturing technology of a dual-layer carbon fiber tube with a foam interlayer. The dual-layer carbon fiber tube with the foam interlayer is rapid in forming and good in bonding quality. The manufacturing technology comprises following steps of inner die forming, carbon fiber tube forming and carbon fiber tube aftertreatment; the forming sted of the carbon fiber tube comprises inner layer carbon fiber tube forming, foam layer forming and outer layer carbon fiber tube forming; an inner carbon fiber tube body and an outer carbon fiber tube body are bonded with the foam layer to a certain degree, the bonding strength is improved, the foam layer absorbs vibration noise, all layers are bonded with a metal joint while being formed, the problem of disalignment of the carbon fiber tube and the joint after bonding is solved, in the bonding process, glue cannot flow in a joint inner hole, and the subsequent work is reduced; when the layers are bonded and formed, the layers are in the rotating state all the time, and glue in the bonding portion is more evenly distributed.