14results about How to "Lower resonance frequency" patented technology

The invention relates to a composite sensor for acceleration and pressure monitoring and a working method thereof, and belongs to the field of sensors, the composite sensor comprises an upper shell, a middle shell and a lower shell, the upper end of the upper shell is provided with an M6 mounting thread, the lower end of the upper shell is a hexagonal base, and a groove space is reserved in the inner side of the lower end of the hexagonal base; the appearance of the middle shell is a hexagonal base, and M5 mouthpiece installation holes are formed in the left side and the right side of the middle shell. A double-end beam sheet is arranged in the middle of the inner side of the middle shell and is of a sheet-shaped structure, and the two ends of the double-end beam sheet are fixedly connected with the front inner wall and the rear inner wall of the middle shell or integrally formed. The center of the double-end beam sheet is provided with an integrally connected cylindrical screw rod, and the cylindrical screw rod is provided with an acceleration sensor core body structure; the appearance of the lower shell is a hexagonal base, and a mounting groove is formed in the bottom of the lower shell and used for mounting a pressure sensor core structure; the upper shell, the middle shell and the lower shell are connected in a welded mode. The device is simple in structure, can realize synchronous monitoring of acceleration and pressure without mutual interference, and can realize multi-scene application at the same time.

The present invention proposes a debugging method for a constant quasi-zero stiffness vibration isolation structure with double pairs of diagonal rod negative stiffness, and the steps are as follows: build a constant quasi-zero stiffness vibration isolation structure including a first pair of diagonal rod assemblies and a second pair of diagonal rod assemblies, and the double pairs of diagonal rod negative stiffness mechanisms are symmetrically arranged on both sides of the positive stiffness mechanism; determine that the pre-compression amount of the horizontal springs in the first pair of diagonal rod assemblies and the second pair of diagonal rod assemblies in the initial state is equal to the horizontal projection length of the diagonal rods; respectively determine the stiffness of the horizontal springs in the first pair of diagonal rod assemblies and the second pair of diagonal rod assemblies and the vertical springs of the positive stiffness mechanism, and construct dimensionless parameters to meet the conditions; when having a constant stiffness characteristic, calculate the stiffness, and calculate the starting vibration isolation frequency according to the relationship between the vibration isolation mass, and if the starting vibration isolation frequency does not meet the design requirements, reconstruct the dimensionless parameters. The present invention can obtain a zero stiffness characteristic that is a straight line near the static equilibrium point, and can obtain a wider range of constant quasi-zero stiffness characteristics.

The invention relates to a high-speed rail joist supporting structure, and relates to the technical field of supporting structures. The device comprises a pier, a supporting beam and a plurality of supporting seats, the pier is vertically arranged, the supporting beam is horizontally arranged and fixed to the top of the pier, the supporting seats are arranged on the supporting beam and distributed at intervals in the length direction of the supporting beam, the top ends of the supporting seats are connected with a high-speed railway bridge, and buffering assemblies are arranged on the supporting seats. The joist supporting structure has the effect that the supporting stability of the joist supporting structure cannot be affected when the high-speed rail bridge is vibrated.

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.

The present invention discloses an acoustic device, comprising: a sound-emitting unit, the sound-emitting unit comprises a vibrating diaphragm, a sound outlet is arranged on the acoustic device, and the sound waves on the front side of the vibrating diaphragm are radiated outward through the sound outlet; a closed closed cavity is formed on the rear side of the vibrating diaphragm, and the closed cavity is divided into a first closed cavity and a second closed cavity by a partition, wherein the partition can be at least partially flexibly deformed, the first closed cavity is adjacent to the vibrating diaphragm, and the second closed cavity is far away from the vibrating diaphragm, and the volume of the second closed cavity is greater than the volume of the first closed cavity; the second closed cavity seals the sound waves generated by the flexible deformation part when deformed in the second closed cavity; at least a part of the housing of the electronic device for installing the acoustic device is used to form the first closed cavity and / or the second closed cavity. The acoustic device in the present invention can effectively reduce the resonant frequency and significantly improve the low-frequency sensitivity of the product as a whole.

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.

The invention relates to the technical field of vehicles, in particular to a roar control method and device of a hybrid power vehicle, the vehicle and a storage medium, and the method comprises the following steps: obtaining an in-vehicle noise value of the hybrid power vehicle; if the in-vehicle noise value is greater than the roar threshold value, determining a target resonant frequency according to the engine speed; and determining a target rotating speed change slope and a target rotating speed adjustment interval of the engine according to the target resonant frequency, and controlling an in-vehicle noise value of the engine to be smaller than or equal to a roar threshold value according to the target rotating speed change slope and the target rotating speed adjustment interval. Therefore, the problem that in-vehicle roaring is caused by resonance generated by coupling with a vehicle body mode at a certain rotating speed during feed low-speed driving of the hybrid electric vehicle is solved.

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 invention relates to the technical field of vibration sensing, in particular to a self-powered three-degree-of-freedom absolute vibration sensor. The device comprises a hanging block, a connecting rod mechanism is assembled on the outer side of the hanging block, the connecting rod mechanism comprises an X-shaped rod set, supporting columns, a buckling beam, a piezoelectric ceramic piece, a detachable damper, a bottom ring, a top ring and a power management circuit, and the three supporting columns are evenly distributed and fixed to the bottom of the hanging block. According to the invention, the suspension block can obtain an extremely low resonant frequency in the horizontal direction through the well designed connecting rod mechanism, the extremely low resonant frequency in the vertical direction is realized through the X rod group, the combination of the two can realize the capture of ultra-low frequency vibration in a three-dimensional space, and the sensitivity is high. And meanwhile, mechanical energy generated by vibration can be converted into electric energy through the piezoelectric buckling beam, and the relative displacement measurer is driven to work, so that self-powered measurement is achieved, use is more environmentally friendly and convenient, the overall structure is compact, transportation is more convenient, and practicability is high.

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 discloses a sound-absorbing and noise-reducing integrated design structure of a wall decorative surface, which comprises an outer layer frame, an inner layer frame, an inner layer frame and a sound-absorbing and noise-reducing layer, the inner-layer frame is arranged in the outer-layer frame; the connecting profile is arranged at a splicing gap between the outer-layer frame and the inner-layer frame; the transverse supporting piece is arranged in the inner-layer frame; the covering cloth covers the surface of the outer-layer frame, and the edge of the covering cloth extends to the back surface of the outer-layer frame; the third aluminum profile is fixedly installed on the holding cloth, and the veneer is fixedly installed on the third aluminum profile. Compared with the prior art, the problem that sound insulation and noise reduction capacity is insufficient due to the fact that sound in a partition wall surface layer decoration material is transmitted through vibration between the surface layer plate and the base layer plate is solved.

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.