Abstract: A construction machine includes: a lower propelling body; and an upper slewing body which is slewably mounted on the lower propelling body. The upper slewing body includes: an engine room provided with an intake opening and a discharge opening; a duct provided in the engine room so as to communicate with the discharge opening; and an exhaust gas pipe which guides exhaust gas discharged from the engine into the duct. The discharge opening and an outlet of the duct are open downward from the engine room. A portion on a distal end side of the exhaust gas pipe is inserted into the duct. The duct and the exhaust gas pipe are configured to cause the exhaust gas to be mixed with cooled air in the duct and cause the mixture of the exhaust gas and the cooled air to be discharged downward from the discharge opening.

Abstract: Sound absorbency is imparted on a panel, which has increased strength and rigidity, by laminating a foam resin that is not originally permeable and does not absorb sound, and surface sheets that are not originally permeable and do not absorb sound. A sound absorption panel 1, obtained by laminating a foam resin 20 comprising closed cells and aluminum alloy sheets 10 (metal sheets), has a plurality of holes 30 formed therein, which penetrate the foam resin 20 and the aluminum alloy sheets 10 in the thickness direction. The holes 30 are formed by forcing a needle 40 (hole-forming means) through the foam resin 20 and the aluminum alloy sheets 10.

Abstract: A construction machine includes: an engine room provided with an intake opening and a discharge opening; a fan for sucking cooling air into the engine room through the intake opening; a duct provided in the engine room so as to communicate with the discharge opening and discharging the cooling air sucked into the engine room to an outside of the engine room through the discharge opening; and an exhaust gas pipe guiding exhaust gas discharged from the engine into the duct. A portion on a distal end side of the exhaust gas pipe is inserted into the duct, and the inserted portion of the exhaust gas pipe inserted into the duct is formed with an exhaust hole which causes the exhaust gas to be discharged in a direction different from a flowing direction of discharge wind in the duct through the exhaust hole.

Abstract: A construction machine includes: a lower propelling body; and an upper slewing body which is slewably mounted on the lower propelling body. The upper slewing body includes: an engine room provided with an intake opening and a discharge opening; a duct provided in the engine room so as to communicate with the discharge opening and an exhaust gas pipe which guides exhaust gas discharged from the engine into the duct. The discharge opening and an outlet of the duct are open downward from the engine room. A portion on a distal end side of the exhaust gas pipe is inserted into the duct. The duct and the exhaust gas pipe are configured to cause the exhaust gas to be mixed with cooled air in the duct and cause the mixture of the exhaust gas and the cooled air to be discharged downward from the discharge opening.

Abstract: Sound absorbency is imparted on a panel, which has increased strength and rigidity, by laminating a foam resin that is not originally permeable and does not absorb sound, and surface sheets that are not originally permeable and do not absorb sound. A sound absorption panel 1, obtained by laminating a foam resin 20 comprising closed cells and aluminum alloy sheets 10 (metal sheets), has a plurality of holes 30 formed therein, which penetrate the foam resin 20 and the aluminum alloy sheets 10 in the thickness direction. The holes 30 are formed by forcing a needle 40 (hole-forming means) through the foam resin 20 and the aluminum alloy sheets 10.

Abstract: According to the invention, there is provided a damping structure capable of obtaining a sufficient damping effect even against vibrations of small amplitudes, by promoting movements of powder/particle materials inside a hollow body. In the damping structure of the invention, a damping member 2 is provided on a structure 1 to be damped. The damping member 2 includes a hollow body 5 which is filled with powder/particle materials 3, partially leaving a space 4. A vibration wall face part 7 which vibrates more violently than the structure 1, on receiving vibration, is formed in at least a part of wall face parts 6 of the hollow body 5. The vibration wall face part 7 is preferably formed of a material having a lower elastic modulus and/or a lower density than the other parts.

Abstract: The present invention provides a damping structure capable of obtaining a sufficient damping effect even against vibrations with small amplitudes, by promoting movements of powder/particle materials in a hollow body. In the damping structure of the invention, a damping member 2 is provided on a structure 1 to be damped. The damping member 2 is composed of a hollow body 5, a powder/particle material 3 which is filled in the hollow body 5 with partially leaving a space 4, and moves inside the hollow body 5 when the structure 1 vibrates, and a vibrator 6 which is mounted inside the hollow body 5, and relatively vibrates with respect to the hollow body 5. The vibrator 6 exerts a force by coming into contact with the powder/particle material, when vibrating.

Abstract: A porous sound absorbing structure 10 includes an exterior plate 1 and a closing plate 2 in order to suppress a decrease in sound absorbing performance in a wide frequency band. An interior plate 3 is arranged between the exterior plate 1 and the closing plate 2, and air layers 4 and 5 are located between the exterior plate 1 and the interior plate 3 and between the interior plate 3 and the closing plate 2 respectively. The exterior plate 1, the interior plate 3, and the closing plate 2 are arranged while opposed to each other. Many through holes 1a and 3a are made in the exterior plate 1 and the closing plate 2 respectively. In the interior plate 3, a plate thickness t2 and a diameter ?2 and an aperture ratio ?2 are set so as to generate an viscous effect in air passing through the through hole 3a. The aperture ratio ?1 of the through hole 1a in the exterior plate 1 is set more than 3% and not more than 50%.

Abstract: A sound absorbing structure having excellent in sound absorbing performance, which is capable of achieving 0.4 or higher in the sound absorbing coefficient even in the case where a perforated panel is a thin plate such as aluminum foil within a range where a reduction in the weight of a vehicle body is not impaired and through holes have a large hole diameter in order to make the processing of providing a large number of through holes in the perforated panel.

Abstract: Problem: To reduce vibration and noise of a bracket and the like, and also to save a work for manufacturing and shorten manufacturing time, in the case that a forced-excitation of a vibrating apparatus is a cause. Solution: There are provided a frame body 1, to which a rotation motor 6 is fixed, and dynamic vibration absorbers 2, 3 which are structured in a manner such that slits are made in a portion of the frame body 1 and the slit part is bent in an upward direction, and is configured so that the vibrating portions 2a, 3a of the dynamic vibration absorbers 2, 3 vibrate in the vibrating direction of the frame body 1 being vibrated by the rotation motor 6.

Abstract: A sound absorbing structure having excellent in sound absorbing performance, which is capable of achieving 0.4 or higher in the sound absorbing coefficient even in the case where a perforated panel is a thin plate such as aluminum foil within a range where a reduction in the weight of a vehicle body is not impaired and through holes have a large hole diameter in order to make the processing of providing a large number of through holes in the perforated panel.

Abstract: The present invention relates to a silencer easily cleanable inside. This silencer comprises a casing cylinder and a segment member housed in the casing cylinder to constitute a sound reducing means. The silencer further comprises a segment member fastening means for fastening the segment member to the casing cylinder, a gas inlet-side lid plate with a punched hole, which closes an opening at one end of the casing cylinder, and a gas outlet-side lid plate with a punched hole, which closes an opening at the other end of the casing cylinder. At least either one of the gas inlet-side lid plate or the gas outlet-side lid plate is adapted to be detachable from the casing cylinder.

Abstract: A porous sound absorbing structure 10 includes an exterior plate 1 and a closing plate 2 in order to suppress a decrease in sound absorbing performance in a wide frequency band. An interior plate 3 is arranged between the exterior plate 1 and the closing plate 2, and air layers 4 and 5 are located between the exterior plate 1 and the interior plate 3 and between the interior plate 3 and the closing plate 2 respectively. The exterior plate 1, the interior plate 3, and the closing plate 2 are arranged while opposed to each other. Many through holes 1a and 3a are made in the exterior plate 1 and the closing plate 2 respectively. In the interior plate 3, a plate thickness t2 and a diameter ?2 and an aperture ratio ?2 are set so as to generate an viscous effect in air passing through the through hole 3a. The aperture ratio ?1 of the through hole 1a in the exterior plate 1 is set more than 3% and not more than 50%.

Abstract: A sound absorbing structure utilizes the vibration of a plate-like body (1), and includes the plate-like body (1), a vibration damping member (2) provided on at least one surface of the plate-like body (1), and an installation portion (3) provided at an opposite side of the vibration damping member against the plate-like body (1).

Abstract: A peak frequency having a high sound absorption coefficient is enlarged. A sound absorbing structure body comprises a concave-convex plate, a closure plate, and first and second partition plates. The concave-convex plate includes a convex portion and a concave portion (concave-convex portion) and an opening. The closure plate is bonded to the concave-convex plate so as to form a hollow portion by closing one of the convex portion and the concave portion, and the hollow portion is communicated with an outside space through the opening. The first and second partition plates have a number of through holes respectively, and the first and second partition plates partition the hollow portion into at least two partitioned spaces.

Abstract: A sound-absorbing structure body according to the present invention comprises a ridge-groove board (11) formed with a large number of ridges and grooves, a closing board (15) joined to the ridge-groove board so as to close one side of the ridge-groove board and thereby form a hollow portion (13), a partition board (21) for partitioning the hollow portion (13) into two or more partitioned spaces (22a, 22b), and two or more holes (25a, 25b) opened in the ridge-groove board so as to bring into communication with each of the two or more partitioned spaces (22a, 22b).

Abstract: A sound-absorbing structure using thin film of the present invention includes at least a first thin film (11) and a second thin film (12), the first thin film (11) and the second thin film (12) being layered over each other and one or both of the first thin film (11) and the second thin film (12) having at least either ridges or grooves (ridges (a) in the selected figure). As each of the thin films (11) and (12), a metallic thin film or a resinous thin film is employable. It is desirable that fine through holes are formed in a large number in the thin films (11) and (12).

Abstract: The present invention relates to a silencer easily cleanable inside. This silencer comprises a casing cylinder and a segment member housed in the casing cylinder to constitute a sound reducing means. The silencer further comprises a segment member fastening means for fastening the segment member to the casing cylinder, a gas inlet-side lid plate with a punched hole, which closes an opening at one end of the casing cylinder, and a gas outlet-side lid plate with a punched hole, which closes an opening at the other end of the casing cylinder. At least either one of the gas inlet-side lid plate or the gas outlet-side lid plate is adapted to be detachable from the casing cylinder.