CN101813156B - Flexible high-precision spacial vibration damping platform - Google Patents

Abstract

The invention is a flexible and high-precision space vibration damping platform, which relates to the field of multi-dimensional vibration reduction and multi-dimensional vibration isolation system manufacturing. It consists of three flexible branch chains with the same structure, a static platform (5) and an upper dynamic platform (1); the flexible branch chain is located between the lower static platform (5) and the upper dynamic platform (1), and the flexible branch chain is The parallelogram flexible mechanism (2) consists of the first connecting rod (G), the second connecting rod (H), the third connecting rod (I), and the fourth connecting rod (J) through four single-axis connected by flexible hinges. The invention eliminates residual vibration, can realize active vibration reduction or vibration isolation in high-precision occasions, has a simple and compact structure, and can meet various vibration reduction requirements of different dimensions.

Description

A flexible and high-precision space vibration damping table

technical field

The invention relates to the field of multi-dimensional vibration reduction and multi-dimensional vibration isolation system manufacturing, in particular to a flexible high-precision space vibration reduction table.

Background technique

Nowadays, engineering structures are mostly complex multi-degree-of-freedom systems, and most of them are broadband excitations, so multi-dimensional vibrations generally exist in various fields. Traditional multi-dimensional vibration reduction devices usually use multi-layer single-degree-of-freedom devices for vibration reduction. For example, the patent No. 99123143.0 and the patent named "Anti-vibration Frame for Ambulance" use a three-layer structure to separately control the upper and lower sides of the anti-vibration frame. Vibration reduction is implemented in the left, right and front and rear directions, but its structure is complex and the vibration reduction is not reliable.

Due to the characteristics of simple structure, high precision and multi-directional movement, the parallel mechanism has gradually been widely used in the field of multi-dimensional vibration reduction. The multi-dimensional vibration damping structure adopts the parallel mechanism as the main vibration damping mechanism and the elastic damping system as the vibration damping actuator, which has a simple structure and strong practicability, and has achieved satisfactory results. There are large or small gaps in each joint. The existence of these gaps causes serious residual vibration of the vibration-damping table under high-frequency motion, seriously affects the vibration-damping performance of the vibration-damping table, and even increases the vibration in individual directions. Amplitude, the friction existing in the joint also reduces the vibration damping accuracy, and the rigid rod in the mechanism is not easy to deform and cannot absorb the vibration energy from the automatic platform, which affects the vibration damping effect of the vibration damping table. Therefore, there is an urgent need in engineering for a vibration reduction device that can achieve multi-dimensional vibration reduction and has high precision.

Contents of the invention

The basic idea of the present invention is to maintain the motion characteristics of the original parallel mechanism, replace the original rigid motion pair with flexible motion pairs, and replace the original rigid rods with flexible rods, so that the vibration reduction dimension required by the vibration reduction table can be maintained , and can eliminate the gap and friction existing in the rigid joints; in order to realize the function of active vibration reduction of the vibration reduction table, a small magneto-rheological damping device is used as the driving source of the shock absorber.

The technical scheme adopted in the present invention is: a three-translation flexible parallel mechanism composed of three flexible branch chains with the same structure, a static platform and an upper moving platform. The flexible branch chain is a parallelogram flexible mechanism, which is composed of the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod respectively connected by four single-axis flexible hinges; the third connecting rod passes through A pair of coaxial single-axis flexible hinges are connected to the moving platform; the first member and the first connecting rod are connected through a pair of coaxial single-axis flexible hinges, and the two ends of the second member are respectively connected to the first member and the second The three components are fixedly connected, and the third component is connected to the static platform through a pair of coaxial single-axis flexible hinges; the small magnetorheological damper is installed between the second component and the static platform, and one end of the small magnetorheological damper is installed on the The middle point of the second member and the other end are fixed on the lower static platform, and the magneto-rheological damper is kept perpendicular to the initial position of the second member. The lower platform of the mechanism is fixed on the vibration source, and the upper platform can place precision instruments, so that the instrument can reduce or eliminate the multi-dimensional vibration generated by the vibration source.

The prominent feature of this device is that it eliminates residual vibration, and can realize active vibration reduction or vibration isolation in high-precision situations. Its structure is simple and compact, it can meet the vibration reduction requirements of various dimensions, and it is easy to realize serialization.

The beneficial effects of the present invention are:

(1) The flexible kinematic pair replaces the traditional rigid kinematic pair. The flexible kinematic pair is a kind of kinematic pair that relies on the elastic deformation of the material to achieve the desired motion output. It can be manufactured as a whole. Compared with the traditional kinematic pair, it has the advantages of no gap and no friction. , so as to form a fully flexible three-translation parallel mechanism, which is used as the main mechanism of the vibration damping table to form a new three-degree-of-freedom flexible vibration damping table.

(2) Three-dimensional vibration reduction can be realized, and the main load direction adopts a small magneto-rheological damper with variable damping, which enhances the adaptability of the active vibration reduction of the device;

(3) It can quickly eliminate vibration in a short time, which is faster and more efficient than passive vibration reduction devices;

(4) It can be used as a vibration damping table for precision instruments with high precision requirements, and can also be used in vibration isolation occasions.

Description of drawings

Fig. 1 is mechanism schematic diagram of the present invention

Fig. 2 is the schematic diagram of branched chain structure in the present invention

In the figure, 1, moving platform; 2, parallelogram flexible mechanism; 3, second member; 4, small magnetorheological damper; 5, static platform; E, first member; G, first connecting rod; H , the second link; I, the third link; J, the fourth link.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic diagram of the mechanism of the present invention, and its main body is composed of three flexible branch chains with the same structure, a static platform 5 and a dynamic platform 1. Fig. 2 is a schematic diagram of the branch chain structure implemented by the present invention. The three flexible branch chains are located under Between the static platform 5 and the upper moving platform 1, the projections of the three branch chains on the static platform 5 are evenly distributed at an angle of 120°. The flexible branch chain structure is shown in Figure 2. The first connecting rod G, the second connecting rod The rod H, the third connecting rod I, and the fourth connecting rod J are respectively connected by four uniaxial flexible hinges to form a parallelogram flexible mechanism 2, and the third connecting rod I is connected to the The moving platform 1 is connected, the first member E is also connected with the first connecting rod G through a pair of coaxial single-axis flexible hinges, and the two ends of the second member 3 are fixedly connected with the first member E and the third member F respectively. , the third member F is connected with the lower static platform 5 through a pair of coaxial single-axis flexible hinges. The shaft axes of a group of four uniaxial flexible hinges in the parallelogram flexible mechanism 2 are parallel to each other; The single-axis flexible hinge of the third member F and the single-axis flexible hinge between the lower static platform 5, the shaft axes of this group of three single-axis flexible hinges are parallel to each other, and the shaft axes of the above-mentioned two groups of single-axis flexible hinges are perpendicular to each other . According to the motion decoupling of the mechanism, when the second member 3 moves under the action of the driving source, the upper moving platform can realize three translational motion outputs.

As shown in FIG. 1 , installing the small magneto-rheological damper 4 on the second component 3 in the branch chain is equivalent to applying a driving force to the second component 3 to prevent its movement. If the lower static platform 5 is placed on the vibration source, according to the inverse motion principle of the parallel mechanism, under the action of the three branch chains, the upper moving platform 1 can produce a relatively small movement, and can actively move according to the movement of the moving platform. Adjust the driving force of the small magneto-rheological damper to make the upper moving platform 1 stable as soon as possible, so as to achieve the purpose of three-dimensional vibration reduction.

Claims (1)

1. A flexible high-precision space vibration damping table is characterized in that it is made up of three flexible branch chains with the same structure, a lower static platform (5) and an upper dynamic platform (1); the three flexible branch chains are located at the lower static platform Between the platform (5) and the moving platform (1), the flexible branch chain is a parallelogram flexible mechanism (2), which consists of the first connecting rod (G), the second connecting rod (H), and the third connecting rod (1), the fourth connecting rod (J) is connected to each other by four uniaxial flexible hinges; the third connecting rod (I) is connected with the upper moving platform (1 ) is connected; the first member (E) is connected with the first connecting rod (G) through a pair of coaxial uniaxial flexible hinges, and the two ends of the second member (3) are respectively connected with the first member (E) and the first The three components (F) are fixedly connected, and the third component (F) is connected to the lower static platform (5) through a pair of coaxial uniaxial flexible hinges; it also includes a small magneto-rheological damper (4), the The small magnetorheological damper (4) is installed between the second member (3) and the lower static platform (5), one end of the small magnetorheological damper (4) is installed at the midpoint of the second member (3), and the other One end is fixed on the lower static platform (5), and the initial position of the small magneto-rheological damper (4) is kept perpendicular to the second member (3); a group of four uniaxial flexible mechanisms in the parallelogram flexible mechanism (2) The shaft axes of the hinges are parallel to each other; the single-axis flexible hinge between the upper moving platform (1) and the parallelogram flexible mechanism (2), and the single-axis flexible hinge between the parallelogram flexible mechanism (2) and the first member (E) The flexible hinge, the single-axis flexible hinge between the third member (F) and the lower static platform (5), the axes of the three single-axis flexible hinges in this group are parallel to each other, and the axes of the axes of the above-mentioned two sets of single-axis flexible hinges are mutually vertical; the projections of the three flexible branch chains on the lower static platform (5) are evenly distributed at an angle of 120°.

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