CN-117847319-B - Double-deck clamp of aircraft pipeline with nonlinear vibration damping function

CN117847319BCN 117847319 BCN117847319 BCN 117847319BCN-117847319-B

Abstract

The invention discloses an aircraft pipeline double-layer clamp with a nonlinear vibration reduction function. The device comprises an inner layer clamp, an outer layer clamp, a clamp gasket, a fastening bolt and a fastening nut, wherein a certain constraint gap exists between the inner layer clamp and the outer layer clamp, the inner layer clamp and the outer layer clamp are assembled on a machine body through the fastening bolt and the fastening nut, the inner layer clamp consists of an inner layer clamp metal band and an inner layer clamp bushing, and the outer layer clamp consists of an outer layer clamp metal band and an outer layer clamp bushing. The inner layer clamp bush and the outer layer clamp bush are both made of nitrile rubber-organic small molecule hybrid composite materials, and excellent damping performance is shown. The invention utilizes the outer layer clamp to provide nonlinear constraint rigidity and nonlinear constraint damping to realize nonlinear vibration reduction, can realize broadband vibration reduction, and effectively improves the vibration reduction performance of the traditional single-layer clamp. The device is easy to manufacture and install, adopts a nonlinear passive vibration control strategy, and realizes high efficiency with low cost.

Inventors

Ding hu
DOU BO
MAO XIAOYE
CHEN LIQUN

Assignees

上海大学

Dates

Publication Date: 20260505
Application Date: 20240126

Claims (4)

1. The double-layer clamp for the aircraft pipeline with the nonlinear vibration reduction function is characterized by comprising an outer-layer clamp, an inner-layer clamp, a first clamp gasket, a second clamp gasket, a fastening bolt and a fastening nut; The outer layer clamp consists of an outer layer clamp metal band and an outer layer clamp bushing, wherein the main body of the outer layer clamp metal band is a metal sheet bent into a 3/4 arc, two ends of the metal sheet extend along a straight line, and bolt round holes for the fastening bolts to extend out are reserved at the extending positions of the two ends of the metal sheet; The inner layer clamp comprises an inner layer clamp metal band and an inner layer clamp bushing, wherein the main body of the inner layer clamp metal band is a metal sheet bent into a 3/4 circular arc, two ends of the inner layer clamp metal band extend along a straight line, and bolt round holes for the fastening bolts to extend out are reserved at the extending positions of the two ends of the inner layer clamp metal band; The outer layer clamp is sleeved outside the inner layer clamp, a certain gap exists between the outer layer clamp and the inner layer clamp, and the extending parts at the two ends of the outer layer clamp and the inner layer clamp are separated through the first clamp gasket and the second clamp gasket and are connected with the aircraft body through the fastening bolts and the fastening nuts; The main body of the inner layer clamp bushing is in contact with the aircraft pipeline and generates constraint force on the aircraft pipeline, and when the vibration amplitude of the part of the aircraft pipeline constrained by the clamp is larger than the gap between the outer layer clamp and the inner layer clamp, the inner layer clamp is in contact with the outer layer clamp, so that the outer layer clamp generates constraint force on the aircraft pipeline.
2. The aircraft pipeline double-layer clamp with the nonlinear vibration reduction function according to claim 1, wherein a certain gap exists between the outer-layer clamp and the inner-layer clamp, so that nonlinear constraint rigidity and nonlinear constraint damping can be generated by the outer-layer clamp, and nonlinear vibration reduction is realized.
3. The aircraft pipeline double-layer clamp with nonlinear vibration reduction function according to claim 1, wherein the outer-layer clamp bush and the inner-layer clamp bush are made of nitrile rubber-organic small molecule hybrid composite materials, and the organic small molecules are hindered phenols, hindered amines and other organic small molecule substances with polar functional groups.
4. The aircraft pipeline double-layer clamp with nonlinear vibration damping function according to claim 1, wherein the width of the outer-layer clamp is slightly smaller than the width of the inner-layer clamp.

Description

Double-deck clamp of aircraft pipeline with nonlinear vibration damping function Technical Field The invention relates to the field of design of clamps for aircraft flow transmission pipelines, in particular to a double-layer clamp with a nonlinear vibration reduction function for an aircraft pipeline. Background The flow transmission pipeline system in the aircraft plays an important role in transmitting power and transmission media, and is like human body blood vessels, which are densely distributed in the whole aircraft. The clip is an indispensable fitting for restricting the flow duct, and is suitable for installation in an aircraft body with limited installation space due to its small size. The traditional single-layer clamp for the aircraft pipeline mainly comprises a metal strap and a rubber bushing, and linear constraint rigidity and constraint damping are mainly generated. The natural frequency of the aircraft pipeline can be far away from the excitation frequency by adjusting the constraint rigidity and the constraint position of the traditional clamp, so that the pipeline can be prevented from resonating to a certain extent. However, the rotation speeds of the aero-engine under different working conditions are different, so that the excitation of the flow transmission pipeline is mostly broadband excitation. In addition, the natural frequency of the flow line may also change as the flow rate or pressure of the fluid in the tube changes. Therefore, it is difficult to avoid occurrence of resonance simply by adjusting the constraint stiffness and the constraint position of the conventional yoke. The alternating stress generated by pipeline resonance can cause fatigue damage to the pipeline, even damage to the pipeline, and serious influence on flight safety. In order to solve the above problems, it is considered that nonlinear constraint stiffness and nonlinear constraint damping are introduced as an outer layer of the band into a conventional single-layer band, thereby improving vibration damping performance of the conventional band. At present, although some researchers have made many beneficial attempts in the field of innovative design of clips for aircraft flow lines, there are still some problems to be solved. For example, patent CN 204300557U devised an integral damping clip, however the damping effect of such clips needs to be achieved by the installation of external dampers, which is not suitable for installation in space-constrained aircraft bodies. Patent CN 111750200B has designed the aeroengine intelligence clamp with damping and locking function of taking off, adopts the initiative control mode to realize the damping function, but its structure is very complicated, needs the energy input moreover, and this tends to increase the manufacturing and the application cost of clamp, has improved the degree of difficulty of mass production and actual engineering application. The patent CN 113669543B discloses an aeroengine duplex clamp with vibration reduction and temperature resistance, which realizes active and passive vibration reduction performance by utilizing magnetorheological fluid and piezoelectric composite materials, but the structure is still too complex, and the manufacturing difficulty is higher. The patent CN 115013597B designs a high damping clamp of an aeroengine based on co-curing winding of fibers and metal wires, and utilizes a composite material to achieve a high damping effect, but the patent does not relate to the nonlinear damping function of the clamp, and the preparation process of the clamp is also relatively complicated. Patent CN 115680883A discloses a three-pipe clamp for an aeroengine, which shortens the time consumption of the process of assembling the clamp when more pipes are provided, but the patent does not pay attention to the vibration damping performance of the clamp. In summary, the existing patents related to the improved design of the clamp structure still have certain technical limitations, so that the nonlinear vibration reduction function of the clamp is difficult to realize, the manufacturing cost is high, and the assembly process is complex. Disclosure of Invention The invention aims to provide the double-layer clamp for the aircraft pipeline, which is low in cost, easy to produce and manufacture and has the nonlinear vibration damping function, so that the vibration damping frequency bandwidth of the clamp is effectively widened, and the vibration damping performance of the traditional single-layer clamp is improved. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the double-layer clamp with the nonlinear vibration reduction function for the aircraft pipeline comprises an inner-layer clamp, an outer-layer clamp, a clamp gasket, a fastening bolt and a fastening nut, wherein a certain constraint gap exists between the inner-layer clamp and the outer-layer clamp, the inner-layer clamp and the oute