CN202203331U - Micro precise resonance-free vibration isolation device based on dry friction damping - Google Patents

Abstract

The utility model discloses a tiny precision non-resonant vibration isolation device based on dry friction damping, characterized in that it includes a sliding column, a stiffness spring, a damping spring, an upper connecting plate, a lower connecting plate and a shell, the upper end of the sliding column is fixed on the upper connecting plate, the lower connecting plate is fixed to the shell, the stiffness spring and the damping spring are fixed on the lower connecting plate, the other end of the stiffness spring is connected to the lower end of the sliding column, and the other end of the damping spring is tightly matched with the side of the sliding column. In this isolation device, four special-shaped stiffness springs provide very small longitudinal and lateral stiffness, ensuring that the isolation system has a lower natural frequency when subjected to vibration excitation. Compared with the prior art, the non-resonant vibration isolation device of the utility model is small in size and has good stability.

Description

A tiny precision non-resonant vibration isolation device based on dry friction damping

Technical field :

The utility model relates to a vibration isolation device for small-mass precision equipment. It is especially suitable for safe vibration isolation protection in all directions of precision equipment such as crystal oscillators and micro hard disks, and belongs to the field of vibration isolation buffer manufacturing of precision electronic equipment.

Background technology :

With the rapid development of processing and manufacturing technology, some precision instruments are becoming more and more integrated, miniaturized, and lightweight. These precision instruments are often carried in mobile equipment such as aircraft, artificial satellites, ships, and tanks. Due to the harsh operating environment of these devices, higher and higher requirements are put forward for the anti-interference ability of precision electronic instruments in environments such as vibration, shock, centrifugal acceleration and noise. In order to improve system accuracy and reliability, vibration isolation measures must be taken for tiny precision instruments to improve their ability to work under various harsh environmental conditions. At the same time, due to the light weight and small size of the micro precision instrument itself, its vibration isolation device must be light in weight, small in size and good in stability in addition to good longitudinal and transverse vibration damping performance.

Existing vibration isolators are mainly designed for heavy-duty electronic equipment. The weight and volume of the vibration isolator itself is much larger than that of tiny precision instruments, so it is not suitable for tiny precision instruments; a small number of vibration isolators for crystal oscillators have complex structures. The requirements for the use environment are very high, and it is easy to cause the actual effect of the vibration isolator under the impact load.

Contents of the invention

technical problem:

The technical problem to be solved by the utility model is to provide a vibration isolator with light weight, small volume, good stability and easy use for the deficiencies of the above-mentioned prior art. No resonance vibration isolation device with vibration buffer.

Technical solutions:

The technical solution adopted by the utility model to solve the technical problem is: a tiny precision non-resonant vibration isolation device based on dry friction damping, which is characterized in that it includes a sliding column, a stiffness spring, a damping spring, an upper connecting plate, a lower connecting plate and The casing, the upper end of the sliding column is fixed on the upper connection plate, the lower connection plate is fixed to the casing, the stiffness spring and the damping spring are fixed on the lower connection plate, and the other end of the stiffness spring It is connected with the lower end of the strut, and the other end of the damping spring is closely matched with the side of the strut.

The sliding column is a polygonal sliding column.

Described stiffness spring is four.

The shell and the lower connecting plate are connected by bolts.

Since the mass of the isolated object is very small, in order to ensure the low natural frequency of the isolation system, a small stiffness is required. In this vibration isolation device, four special-shaped stiffness springs provide very small longitudinal and transverse stiffness to ensure that the vibration isolation system has a lower natural frequency when it is excited by vibration. When the shock isolation system is impacted, the special-shaped rigidity spring of the upper connecting plate is in contact with the upper arc part, and the damping spring is in close contact with the sliding column. When the sliding column and the damping spring move relative to each other or have a tendency to move relative to each other, there is a gap between the two. Friction, which provides the damping force to the system and dissipates the energy of the vibration.

Compared with the prior art, the non-resonance vibration isolation device of the utility model has small volume and good stability.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a schematic structural view of the stiffness spring of the present invention.

Fig. 3 is a vibration isolation curve diagram of the vibration isolation device of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in detail:

As shown in Figure 1, the vibration isolation device of the utility model has four holes on the upper connecting plate 1 to connect with precision instruments, and the upper connecting plate 1 is connected to the upper part of the sliding column 2 through bolts, and the sliding column 2 is polygonal. In this embodiment Among them, it is an octagonal sliding column. The bottom of the sliding column 2 is connected with four stiffness springs 3 by screws, the upper part of the damping spring 4 is in interference fit with the side of the sliding column 2, the bottom of the stiffness spring 3 and the bottom of the damping spring 4 are riveted with the lower connecting plate 5, and the stiffness spring 3 The schematic diagram of the structure is shown in Figure 2. The shell 6 is connected with the lower connecting plate 4 through threads, and is connected with the foundation of the electronic equipment.

working principle:

。当滑柱与阻尼弹簧相对运动或者有相对运动趋势时，两者之间存在摩擦力，这给系统提供阻尼力。因此，该系统可表示为： The damping spring of this shock isolation system is in close contact with the sliding column, and the damping spring has a positive pressure on the sliding column

. When the spool and the damping spring move relative to each other or tend to move relative to each other, there is friction between the two, which provides damping force to the system. Therefore, the system can be expressed as:

为被隔震对象的质量，为刚度系数，

为摩擦系数；

为摩擦面法向正压力；为符号函数。 In the formula:

is the mass of the isolated object, is the stiffness coefficient,

is the coefficient of friction;

is the normal positive pressure on the friction surface; is a symbolic function.

基础激励，即基础受到激振力为

时，隔震系统由干摩擦阻尼消耗振动的能量。根据能量能效原理，可以得到隔震系统的等效粘性阻尼系数

： When the system is subjected to a displacement of

The foundation is excited, that is, the foundation is subjected to an exciting force of

When , the vibration isolation system dissipates the vibration energy by dry friction damping. According to the principle of energy efficiency, the equivalent viscous damping coefficient of the isolation system can be obtained

:

可以表示为： The equivalent viscous damping ratio of the system

It can be expressed as:

 

 

不难计算出干摩擦阻尼系统作稳态强迫振动时的振幅

： according to

It is not difficult to calculate the amplitude when the dry friction damping system is subjected to steady-state forced vibration

:

 

 

Substituting the above formula, the amplitude of the steady-state vibration is obtained as:

时，库伦阻尼力从结构上将质量块与基础“锁”在一起，质量块没有产生与基础的相对振动；只有当

时，质量块与基础才能够“解锁”，振动才能继续。 Visible, when

When , the Coulomb damping force structurally "locks" the mass block and the foundation together, and the mass block does not generate relative vibration with the foundation; only when

Only when the mass block and the foundation can be "unlocked" can the vibration continue.

时，振动系统的隔振传递率为： When the dry friction damping force satisfies the condition

When , the vibration isolation transmissibility of the vibration system is:

 

 

Substituting the formula, and into the above formula, we can get:

时，质量块没有产生与基础的相对振动，即

。 When the dry friction damping force satisfies the condition

When , there is no relative vibration between the mass block and the foundation, that is

.

Therefore, the vibration isolation transmissibility of the vibration system with dry friction damping is:

 

，使得隔震系统实现在外界激励下没有共振放大，即隔震系统无谐振，其隔震曲线如图3所示。 Appropriate friction can be obtained by adjusting the structure of the damping spring

, so that the isolation system has no resonance amplification under external excitation, that is, the isolation system has no resonance, and its isolation curve is shown in Figure 3.

Claims (4)

1. small accurate non-resonant vibration isolation device based on dry-friction damping; It is characterized in that: comprise traveller, rigid spring, damping spring, upper junction plate, lower connecting plate and shell; Described traveller upper end is fixed on the described upper junction plate, and described lower connecting plate and described shell are fixed, fixing described rigid spring and damping spring on lower connecting plate; The other end of rigid spring is connected with the lower end of traveller, and the other end of damping spring and the side of traveller closely cooperate.

2. the small accurate non-resonant vibration isolation device based on dry-friction damping according to claim 1, it is characterized in that: described traveller is the polygonal traveller.

3. the small accurate non-resonant vibration isolation device based on dry-friction damping according to claim 1, it is characterized in that: described rigid spring is four.

4. the small accurate non-resonant vibration isolation device based on dry-friction damping according to claim 1 is characterized in that: described shell adopts bolt to be connected with lower connecting plate.

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