7results about How to "Lower resonance frequency" patented technology

The application aims to provide a low-frequency broadband sound insulation unit with ventilation and heat exchange functions, comprising an acoustic resonance cavity, a ventilation adjusting baffle, an elastic pre-tightening film, and a sound absorption rib group, wherein the acoustic resonance cavity comprises an upper cavity, a middle cavity, and a lower cavity from top to bottom, and the inner and outer sides of the acoustic resonance cavity are respectively provided with an inner ventilation hole and an outer ventilation hole; the ventilation adjusting baffle comprises a baffle and an adjusting handle, the adjusting handle is fixed on the baffle, the baffle is installed and constrained on the acoustic resonance cavity through an L-shaped positioning slot, one end of the elastic pre-tightening film is constrained through a film fixing device, and the other end is bonded with the end of the acoustic resonance cavity; and the sound absorption rib group is distributed in the upper cavity and the lower cavity. The application has the advantages of light weight, reliability, small space occupation, etc., can be arranged in a periodic array according to the size of the sound insulation space, has strong applicability, has double functions of sound insulation and heat exchange, and makes up for the disadvantages of deterioration of sound insulation quantity when the traditional sound insulation device has ventilation holes.

This utility model provides an automatic feeding device for steel shot production, relating to the field of automatic feeding technology. It includes: a feeding mechanism, a collecting mechanism at the top of the feeding mechanism, a support frame, a main board at the top of the support frame, a flexible hopper at the lower end of the main board, a rubber vibration damper at the front end of the main board, and a side plate on the left side of the rubber vibration damper. This utility model designs the feeding hopper as a split structure, consisting of a main board, a side plate, and a second side plate. Rubber vibration dampers are installed between the main board and the side plates, and between the side plates themselves. When the feeding hopper is severely worn by the steel shot, it is not necessary to replace the entire feeding hopper; only the severely worn parts need to be replaced individually. Furthermore, the rubber vibration dampers can reduce the resonance frequency transmitted from the main board to the side plate, and reduce the resonance frequency transmitted from the first side plate to the second side plate, thereby reducing noise.

According to the technical scheme, the exhaust temperature sensor is characterized in that the exhaust temperature sensor comprises a mounting pipe and a temperature measuring head, the temperature measuring head is arranged at the first end of the mounting pipe and extends out of the second end of the mounting pipe through a wire, the mounting pipe comprises a main rod and a sliding rod, and the main rod is provided with a nut, a first damping part, a second damping part and a control part; the multiple sets of first damping parts are arranged in the circumferential direction of the main rod at equal intervals. A mounting gap is reserved between every two adjacent first damping parts, and the second damping parts are arranged in the mounting gaps in a one-to-one mode. The end, facing the sliding rod, of the main rod is provided with a mounting part for mounting the control piece, and the control piece is rotationally connected to the mounting part and is in linkage with each second damping piece. One end, facing the main rod, of the sliding rod is provided with a plugging part, a rotation limiting structure is arranged between the plugging part and the mounting part, and the temperature sensor can improve the contact area with the wall of a mounting pipe, reduces the temperature influence, and is not influenced by the mounting position.

This utility model discloses a wireless controller with automatic magnetic pole positioning function, belonging to the field of wireless controller technology. It includes a controller and a mounting plate. The lower surface of the controller is provided with a sliding groove, and the upper surface of the mounting plate is provided with a shock-absorbing component. In this utility model, by providing the shock-absorbing component, during the movement of the controller, the travel block slides within the travel groove under the limitation of the limiting rod. Under the action of the shock-absorbing spring, the movement distance of the travel block is controlled, thereby controlling the up-and-down vibration frequency of the controller under the action of the connecting rod and the damping shock absorber. This realizes the shock-absorbing function of the wireless controller, improves the vibration reduction effect during operation, reduces the resonance frequency of the wireless controller, further reduces the possibility of loosening of internal components during operation, and improves the service life and stability of the wireless controller.

The utility model relates to the technical field of acoustic detection, in particular to an acoustic sound absorption performance detection sample piece with a spiral groove, which comprises a sealed shell with a resonant cavity, one surface of the shell protrudes inwards to form a convex block, and the convex block is provided with a spiral groove. A spiral groove is formed in the surface, provided with the protruding block, of the shell in the direction of the protruding block, and the spiral groove is communicated with the resonant cavity. The spiral groove is located in the protruding block of the detection sample piece, namely the neck of the resonator, the equivalent length is increased, the size is compressed, the spiral groove can achieve a long sound channel path in a very small physical space, equivalently, the equivalent neck length is increased, and a very long linear structure is not needed. Besides, low-frequency resonance can be realized while the small size can be kept through the structural arrangement, and the resonant frequency under a given volume can be made lower by taking the convex block with the spiral groove in the detection sample piece as the neck part.

The utility model belongs to the technical field of constructional engineering, and particularly relates to a light modular equipment base system. Comprising a plurality of equipment base units, and each equipment base unit comprises a concrete base, a vibration isolator, a steel structure column foot, first profile steel and second profile steel; the bottom of the vibration isolator is fixedly connected to the top of the concrete base; the bottoms of the steel structure column feet are fixedly connected to the tops of the vibration isolators, and the tops are used for installing equipment; the two transverse side walls of a stand column of the steel structure column foot are symmetrically connected with two pieces of first profile steel arranged in parallel correspondingly, and the two longitudinal side walls of the stand column of the steel structure column foot are symmetrically connected with two pieces of second profile steel arranged in parallel correspondingly. The equipment base units are at least connected with one adjacent equipment base unit through the first profile steel or the second profile steel, so that all the equipment base units form an integral frame. The fixing and vibration isolation mounting base is provided for equipment, meanwhile, the using amount of concrete is reduced, the overall weight is light, and the manufacturing cost is low.

The utility model relates to the technical field of antennas, and discloses an air dielectric satellite positioning antenna, which comprises an antenna metal sheet and a metal reflecting plate, a metal branch foot part, a signal feed foot part and a metal supporting foot part are arranged on the antenna metal sheet, and the metal supporting foot part is fixedly connected with the metal reflecting plate in an insulating manner. According to the utility model, the distribution of electric field lines at the edge of the metal antenna in the cavity resonance structure is changed through a metal stamping process, the miniaturization of the cavity resonance structure is realized, and the weight problem of the ceramic antenna is solved.