Design method of hydraulic rubber composite vibration isolation device

Abstract

The invention discloses a design method of a hydraulic rubber composite vibration reduction device, belongs to the technical field of vibration isolation installation of aviation equipment, is used for designing the hydraulic rubber composite vibration isolation device, and can shorten the design time of the vibration isolation device and improve the safety of research and development tests. The method comprises the steps that S1, parameter matching theory calculation, simulation and design are conducted according to the rigidity and damping requirements of an engine at different frequencies, and target parameters of a vibration reduction device are obtained and comprise the static rigidity and the dynamic rigidity and damping coefficients at different frequencies; s2, a lumped parameter simulation model of the vibration reduction device is built, key parameters of the vibration reduction device are adjusted to meet the target parameters in the step S1, and the key parameters comprise the equivalent piston area, the volume rigidity, the flow channel damping coefficient and the inertia coefficient of the vibration reduction device; and S3, the static rigidity, the equivalent piston area, the volume rigidity and the runner parameters of the damping device are designed, a design scheme is formed, and the key parameters in the step S2 are met.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation equipment vibration isolation installation, and in particular relates to a design method of a hydraulic rubber composite vibration isolation device. Background Art

[0002] The aircraft engine vibration isolation system mainly uses hydraulic rubber composite vibration isolation devices for vibration isolation. Because the aircraft engine needs to transmit large thrust and torque to the aircraft, high requirements are placed on the hydraulic rubber composite vibration isolation devices used. If the connection stiffness between the engine and the vibration isolation system is large, most of the engine vibration will still be directly transmitted to the aircraft body. Especially when the aircraft is landing, the amplification factor of the impact acceleration of the engine during the landing process is required to be as small as possible. This requires the hydraulic rubber composite vibration isolation device to have lower stiffness and greater damping at a specific impact frequency when the aircraft lands, and the dynamic stiffness increases rapidly after the dynamic stiffness valley frequency, and the dynamic stiffness tends to be stable after reaching the peak value.

[0003] However, the technical requirements for engine vibration reduction and impact resistance are different for different types of aircraft, which are determined by the aircraft structure and engine model. Therefore, the hydraulic rubber composite vibration isolation devices used in new aircraft models need to be redesigned to make their performance parameters meet the requirements of new aircraft models. This not only consumes a lot of time, but also requires a large number of landing tests, and safety during the landing test cannot be guaranteed.

[0004] Therefore, there is a need for a design method for a hydraulic rubber composite vibration isolation device that can quickly carry out targeted design according to the technical requirements of engine vibration reduction and impact resistance of different types of aircraft, shorten the design time of the hydraulic rubber composite vibration isolation device, and improve the safety of research and development tests. Summary of the invention

[0005] The present invention provides a design of a hydraulic rubber composite vibration isolation device, which is used for the design of the hydraulic rubber composite vibration isolation device to ensure that the device can meet the specific impact frequency and vibration isolation requirements of a new type of aircraft during landing, shorten the design time of the hydraulic rubber composite vibration isolation device, and improve the safety of aircraft research and development tests.

[0006] To achieve the above object, a design method of a hydraulic rubber composite vibration isolation device comprises the following steps: Step S1, according to the technical requirements of stiffness and damping of the target engine at different frequencies, parameter matching theoretical calculation, simulation and design are performed to obtain target parameters of the hydraulic rubber composite vibration damping device, wherein the target parameters include static stiffness, and dynamic stiffness and damping coefficient at different frequencies; Step S2, determining and building a concentrated parameter simulation model of the hydraulic rubber composite vibration isolation device based on the basic structure of the hydraulic rubber composite vibration isolation device, adjusting the key parameters of the liquid rubber composite vibration isolation device to meet the target parameters obtained in step S1, wherein the key parameters include the equivalent piston area, volume stiffness, flow channel damping coefficient and inertia coefficient of the liquid rubber composite vibration isolation device; Step S3, designing the static stiffness, equivalent piston area, volume stiffness and flow channel parameters of the hydraulic rubber composite vibration damping device to form a preliminary design scheme of the hydraulic rubber composite vibration damping device so that it meets the key parameters obtained in step S2.

[0007] like Figure 1 As shown in the figure, the dynamic stiffness of the hydraulic rubber composite vibration isolation device gradually decreases with the increase of frequency in the low frequency band, and rapidly increases to the peak value after reaching the valley value, and then tends to stabilize with the increase of frequency; the loss factor of the vibration isolation device, that is, the loss angle, gradually increases with the increase of frequency at the beginning, and rapidly decreases after reaching the peak value, and stabilizes at a smaller value. In the stiffness and damping technical requirements for engine installation, it is required that the dynamic stiffness of the hydraulic rubber composite vibration isolation device shows a downward trend in a certain small frequency band and is less than the static stiffness, and at the same time has a larger damping coefficient. The traditional design method is carried out through trial production and test methods. In order to achieve the required vibration isolation performance for the target engine, the hydraulic rubber composite vibration isolation device needs to be adjusted and tested for a long time and in large quantities, and needs to go through multiple rounds of structural version optimization, and the design cycle is relatively long. The design method of the present invention builds a concentrated parameter simulation model of a hydraulic rubber composite vibration isolation device, adjusts key parameters such as the equivalent piston area, volume stiffness, flow channel diameter and length of the liquid rubber, and then performs structural design on the liquid rubber composite vibration reduction device to achieve the required vibration isolation performance. There is no need to trial-produce the actual product before the design is finalized. Through multiple rounds of virtual model verification and optimization, the final structural finalization scheme is finally determined. Since the version cycle of virtual model simulation verification and optimization is much lower than that of trial production and test verification, the design cycle and cost can be greatly shortened.

[0008] Preferably, in step S2, the basic structure of the hydraulic rubber composite vibration isolation device based on which the concentrated parameter simulation model of the hydraulic rubber composite vibration reduction device is built is as follows: the hydraulic rubber composite vibration isolation device includes an upper body and a lower body, the upper body is connected to the lower body through a flow channel plate, the upper body and the lower body are symmetrically arranged at the upper and lower ends of the flow channel plate, and respectively form a first hydraulic chamber and a second hydraulic chamber with the flow channel plate, the first hydraulic chamber is connected to the second hydraulic chamber through a flow channel opened on the flow channel plate, the upper body and the lower body both include a hydraulic chamber sleeve and a rubber spring, and the outer end of the rubber spring is embedded with a connecting core shaft that can be connected to the vibration isolation mounting device on the aircraft engine. The use of a standard mechanism model can greatly reduce the design cycle.

[0009] Preferably, in step S2, when adjusting the key parameters of the hydraulic rubber composite vibration damping device, the adaptation is performed according to 1.6 to 2.4 times of the static stiffness in the target parameters obtained in step S1. Designing the hydraulic cavity will reduce the static stiffness of the hydraulic rubber composite vibration damping device, so it is designed to be 1.6 to 2.4 times the technical requirement value to ensure that the static stiffness of the vibration damping device meets the technical requirements after the design is completed.

[0010] Preferably, in step S2, the key parameters of the hydraulic rubber composite vibration isolation device are adjusted according to the following formula so that the dynamic stiffness of the hydraulic rubber composite vibration isolation device with respect to the vibration frequency s is and the damping coefficient Satisfy the target parameters obtained in step S1:

[0011] in, is the combined stiffness of the two rubber springs (2), is the damping coefficient, is the equivalent piston area of ​​the flow channel plate (5), , and are the volume stiffness of the first hydraulic chamber (4) and the second hydraulic chamber (6), respectively. and are the flow channel damping coefficient and inertia coefficient, is the average pressure in static equilibrium, is the initial displacement, It can be obtained through simulation calculation, , , , , , , and The value of can be set directly.

[0012] Preferably, in step S3, the static stiffness is adjusted by adjusting the material of the rubber spring, increasing or decreasing the thickness of the rubber layer, and changing the structure of the partition.

[0013] Preferably, in step S3, the adjustment of the equivalent piston area is achieved by increasing the volume of the hydraulic chamber.

[0014] Preferably, in step S3, the volume stiffness is adjusted by adjusting the shape and structure of the hydraulic chamber.

[0015] The rubber body structure is "dug" to design the hydraulic chamber. The orthographic projection area of ​​the hydraulic chamber is slightly larger than the equivalent piston area to ensure that the preliminary design value is close to the target value. Then the preliminary structure is simulated by finite element to calculate its static stiffness, equivalent piston area and volume stiffness. The static stiffness can be adjusted by adjusting the thickness of the rubber layer, the partition and other structures, and the projection area can be increased or decreased by increasing the volume of the hydraulic chamber, thereby adjusting the equivalent piston area; the volume stiffness can be adjusted by adjusting the shape and structure of the hydraulic chamber. The three parameters have the characteristics of mutual influence, and multiple rounds of adjustment, verification and optimization are required in the adjustment to finally achieve accurate design.

[0016] Preferably, in step S3, the channel is designed with structures such as a flow channel tube or a flow channel groove in the flow channel plate, and is precisely designed according to matching diameters and lengths to achieve adjustment of the flow channel damping coefficient and inertia coefficient.

[0017] Preferably, the design method further includes step S4, performing precise simulation of fluid-solid coupling dynamic performance of the preliminary design scheme obtained in step S3, calculating the variation law of dynamic stiffness and damping value of the structural scheme at different frequencies and amplitudes, and performing local structural adjustment and optimization according to the simulation results to meet the technical requirements of the target engine, thereby obtaining the final design scheme of the hydraulic rubber composite vibration damping device.

[0018] Preferably, the design method further includes step S5, conducting sample trial production and static and dynamic stiffness test verification on the final design scheme formed in step S4 to verify the dynamic and static performance of the sample, and then installing the liquid rubber vibration damping device into the vibration damping system to perform vibration isolation and drop test verification.

[0019] The present invention is described in detail below with reference to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a curve diagram showing the dynamic stiffness and loss angle of the hydraulic rubber composite vibration isolation device changing with frequency; Figure 2 It is a schematic flow chart of a design method of a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the appearance of a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the tilted appearance of a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention; Figure 5 It is a three-dimensional cross-sectional view of a hydraulic rubber composite vibration isolation device according to an embodiment of the present invention; Figure 6 It is a vertically symmetrical cross-sectional view of the hydraulic rubber composite vibration isolation device according to an embodiment of the present invention.

[0021] The above drawings include the following reference numerals: 1. Hydraulic chamber sleeve; 2. Rubber spring; 3. Connecting mandrel; 4. First hydraulic chamber; 5. Flow channel plate; 51. Flow channel; 6. Second hydraulic chamber. DETAILED DESCRIPTION

[0022] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0023] See also Figure 1 In a preferred embodiment of the present invention, a design method is provided, comprising the following steps: Step S1, according to the technical requirements of stiffness and damping of the target engine at different frequencies, perform parameter matching theoretical calculation, simulation and design to obtain target parameters of the hydraulic rubber composite vibration damping device, wherein the target parameters include static stiffness, and dynamic stiffness and damping coefficient at different frequencies; Step S2, see Figure 3-6 , comprising an upper body and a lower body, the upper body being connected to the lower body via a flow channel plate (5), the upper body and the lower body being symmetrically arranged at the upper end and the lower end of the flow channel plate (5), respectively enclosing a first hydraulic chamber (4) and a second hydraulic chamber (6) with the flow channel plate (5), the first hydraulic chamber (4) being connected to the second hydraulic chamber (6) via a flow channel (51) provided on the flow channel plate (5), the upper body and the lower body both comprising a hydraulic chamber sleeve (1) and a rubber spring (2), the outer end of the rubber spring (2) being embedded with a connecting core shaft (3) which can be connected to a vibration isolation mounting device on an aircraft engine; Based on the basic mechanism of the hydraulic rubber composite vibration isolation device, a concentrated parameter simulation model of the hydraulic rubber composite vibration isolation device is constructed, and the key parameters of the liquid rubber composite vibration isolation device are adjusted to meet the target parameters obtained in step S1, wherein the key parameters include the equivalent piston area, volume stiffness, flow channel damping coefficient and inertia coefficient of the liquid rubber composite vibration isolation device; When adjusting the key parameters of the liquid rubber composite vibration damping device, the static stiffness in the target parameter obtained in step S1 is adjusted by twice; and the key parameters of the hydraulic rubber composite vibration isolation device are adjusted according to the following formula, so that the dynamic stiffness of the hydraulic rubber composite vibration isolation device about the vibration frequency s is and the damping coefficient Satisfy the target parameters obtained in step S1:

[0024] in, is the combined stiffness of the two rubber springs (2), is the damping coefficient, is the equivalent piston area of ​​the flow channel plate (5), , and are the volume stiffness of the first hydraulic chamber (4) and the second hydraulic chamber (6), respectively. and are the flow channel damping coefficient and inertia coefficient, is the average pressure in static equilibrium, is the initial displacement, It can be obtained through simulation calculation, , , , , , , and The value of can be set directly.

[0025] Step S3, designing the static stiffness, equivalent piston area, volume stiffness and flow channel parameters of the hydraulic rubber composite vibration damping device to form a preliminary design scheme of the hydraulic rubber composite vibration damping device so that it meets the key parameters obtained in step S2; The combined stiffness is adjusted by adjusting the material of the rubber spring (2), increasing or decreasing the thickness of the rubber layer, and changing the partition structure, thereby adjusting the static stiffness of the hydraulic rubber composite vibration reduction device; the equivalent piston area is adjusted by increasing the volume of the hydraulic cavity; the volume stiffness is adjusted by adjusting the shape and structure of the hydraulic cavity; the damping coefficient and inertia coefficient of the flow channel are adjusted by designing a flow channel tube or flow channel groove in the flow channel plate and accurately designing it according to the matching diameter and length. When adjusting these three parameters, the static stiffness is adjusted first, then the equivalent piston area is adjusted, and finally the volume stiffness is adjusted.

[0026] Step S4, accurately simulate the fluid-solid coupling dynamic performance of the preliminary design scheme obtained in step S3, calculate the change law of the dynamic stiffness and damping value of the structural scheme at different frequencies and amplitudes, and adjust and optimize the local structure according to the simulation results to meet the technical requirements of the target engine, and obtain the final design scheme of the hydraulic rubber composite vibration reduction device.

[0027] Step S5, the final structural scheme formed in step S4 is subjected to sample trial production and static and dynamic stiffness test verification to verify the dynamic and static performance of the sample, and then the liquid rubber vibration reduction device is installed in the vibration reduction system to perform vibration isolation and drop shock test verification.

[0028] At this point, the design of the hydraulic rubber composite vibration damping device is completed.

[0029] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A design method for a hydraulic rubber composite vibration isolation device, characterized in that: The following steps are involved: Step S1, according to the technical requirements of stiffness and damping of the target engine at different frequencies, perform parameter matching theoretical calculation, simulation and design to obtain target parameters of the hydraulic rubber composite vibration damping device, wherein the target parameters include static stiffness, and dynamic stiffness and damping coefficient at different frequencies; Step S2, determining and building a concentrated parameter simulation model of the hydraulic rubber composite vibration isolation device based on the basic structure of the hydraulic rubber composite vibration isolation device, adjusting the key parameters of the liquid rubber composite vibration isolation device to meet the target parameters obtained in step S1, wherein the key parameters include the equivalent piston area, volume stiffness, flow channel damping coefficient and inertia coefficient of the liquid rubber composite vibration isolation device; Step S3, designing the static stiffness, equivalent piston area, volume stiffness and flow channel parameters of the hydraulic rubber composite vibration damping device to form a design scheme of the hydraulic rubber composite vibration damping device so that it meets the key parameters obtained in step S2.

2. The design method of the hydraulic rubber composite vibration isolation device according to claim 1 is characterized in that: In step S2, the basic structure of the hydraulic rubber composite vibration isolation device is as follows: the hydraulic rubber composite vibration isolation device comprises an upper body and a lower body, the upper body is connected to the lower body via a flow channel plate (5), the upper body and the lower body are symmetrically arranged at the upper end and the lower end of the flow channel plate (5), and respectively enclose a first hydraulic chamber (4) and a second hydraulic chamber (6) with the flow channel plate (5), the first hydraulic chamber (4) is connected to the second hydraulic chamber (6) via a flow channel (51) provided on the flow channel plate (5), the upper body and the lower body both comprise a hydraulic chamber sleeve (1) and a rubber spring (2), and the outer end of the rubber spring (2) is embedded with a connecting core shaft (3) that can be connected to a vibration isolation mounting device on an aircraft engine.

3. The design method of the hydraulic rubber composite vibration isolation device according to claim 2 is characterized in that: In step S2, when adjusting the key parameters of the liquid rubber composite vibration damping device, the adaptation is performed according to 1.6 to 2.4 times of the static stiffness of the target parameters obtained in step S1.

4. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S2, the key parameters of the hydraulic rubber composite vibration isolation device are adjusted according to the following formula so that the dynamic stiffness of the hydraulic rubber composite vibration isolation device with respect to the vibration frequency s is and the damping coefficient Satisfy the target parameters obtained in step S1: in, is the combined stiffness of the two rubber springs (2), is the damping coefficient, is the equivalent piston area of ​​the flow channel plate (5), , and are the volume stiffness of the first hydraulic chamber (4) and the second hydraulic chamber (6), respectively. and are the flow channel damping coefficient and inertia coefficient, is the average pressure in static equilibrium, is the initial displacement, It can be obtained through simulation calculation, , , , , , , and The value of can be set directly.

5. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3, the combined stiffness is adjusted by adjusting the material of the rubber spring (2), increasing or decreasing the thickness of the rubber layer, and changing the structure of the diaphragm, thereby adjusting the static stiffness of the hydraulic rubber composite vibration isolation device.

6. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3, the equivalent piston area is adjusted by increasing the volume of the hydraulic chamber.

7. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3, the volume stiffness is adjusted by adjusting the shape and structure of the hydraulic chamber.

8. The design method of the hydraulic rubber composite vibration isolation device according to claim 3 is characterized in that: In step S3, the damping coefficient and inertia coefficient of the flow channel are adjusted by designing structures such as flow channel tubes or flow channel grooves in the flow channel plate and accurately designing them according to matching diameters and lengths.

9. The design method of the hydraulic rubber composite vibration isolation device according to any one of claims 1 to 8, characterized in that: The method further includes: step S4, accurately simulating the fluid-solid coupling dynamic performance of the preliminary design scheme obtained in step S3, calculating the variation law of the dynamic stiffness and damping value of the structural scheme at different frequencies and amplitudes, and adjusting and optimizing the local structure according to the simulation results to meet the technical requirements of the target engine, thereby obtaining the final design scheme of the hydraulic rubber composite vibration reduction device.

10. The design method of the hydraulic rubber composite vibration isolation device according to claim 9 is characterized in that: The method also includes: step S5, carrying out sample trial production and static and dynamic stiffness test verification on the final design scheme formed in step S4, verifying the dynamic and static performance of the sample, and then installing the liquid rubber vibration reduction device into the vibration reduction system to carry out vibration isolation and drop test verification.

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