CN106423834B - A kind of indeterminate modularization girder adjustable amplitude low-frequency vibration flip flop screen - Google Patents

Abstract

An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen, including a screen body, a spring support seat, a damping spring, a motor, a bracket, and an ultra-statically indeterminate exciting vibration main beam composed of a pipe beam and a fixed plate. There is a floating screen frame on the screen body, and an elastic screen surface is provided on the screen body and the floating screen frame. The floating screen frame is suspended and installed on the lower part of the screen body through rubber hinges. Swing up and down to speed up the material running speed and avoid load concentration; the polyurethane elastic screen surface is composed of multiple rectangular sieve plates, and the two ends of each sieve plate are respectively installed on the fixed beam of the screen body and the floating beam of the floating screen frame. The floating screen frame and the screen body are connected by rubber hinges, and an amplitude adjustment spring is installed between them. The exciter is arranged inside the side plate and the statically indeterminate main beam. It is compact in structure, high in reliability, easy to adjust the movement form and working amplitude of the relaxation screen, and is most suitable for dry deep screening of wet fine coal in coal preparation plants.

Description

An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen

technical field

The invention relates to a vibrating relaxation screen, in particular to an ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen suitable for coal screening, and belongs to the technical field of coal preparation machinery.

Background technique

Sieving is an important part of coal processing. Vibrating screens have been widely used as coal screening equipment in coal preparation plants. With the application of fully mechanized raw coal mining automation technology, the degree of raw coal fragmentation has increased, coupled with the application of hydraulic coal mining, underground water spraying and dust prevention, etc., resulting in an increase in fine-grained components and moisture content in raw coal, often resulting in fine-grained coal caking Agglomerates, and the paste blocks the sieve surface. For this kind of wet fine-grained coal, the screening efficiency of ordinary vibrating screen is low, and it is difficult to carry out effective deep dry screening.

Vibrating relaxation screen is a new type of screening equipment for wet fine-grained coal. Compared with ordinary vibrating screens, vibrating relaxation screens are composed of a screen body and a floating screen frame, and the two are flexibly connected. The sieve body reciprocates under the action of the exciter to form the main vibration. According to the principle of dynamic sub-resonance, there is relative vibration between the floating sieve frame and the sieve body, forming additional motion. The screen surface is made of polyurethane elastic material. The two ends of the screen surface are respectively fixed on the screen body and the floating screen frame. In this way, higher throwing acceleration and larger screen hole deformation can be obtained to prevent material accumulation and adhesion.

At present, in the field of vibrating relaxation screen design, it can be roughly divided into circular vibration relaxation screen and linear vibration relaxation screen according to different motion forms. The patent documents with application numbers 2014108478863 and 2013200375643 disclose a single-layer relaxation sieve type screening equipment, and the patent documents with application numbers 2014108550974 and 2014208681285 disclose a multi-layer relaxation sieve type screening equipment. The structure of the vibrating screen is similar to that of the circular vibrating screen, and its common feature is that it is driven by a single eccentric exciter. The exciter is fixed through the side plate, and the exciting force directly acts on the side plate; The frame and the screen body are connected by shearing rubber springs, and reciprocate and translate relative to the screen body. From the perspective of screening technology, circular motion has a large processing capacity and simple structure, but it has poor effect on conveying and stratifying materials on the screen surface, requires a certain inclination angle during installation, and takes up too much space. The rubber shear spring is easy to tear after being subjected to reciprocating shear force for a long time. At the same time, the action of the shear force makes the rubber heat, which causes the rubber to become hard and brittle, and fails, reducing the reliability of the vibrating relaxation screen. In addition, when this type of vibratory relaxation screen is to achieve low frequency (<600r/min) and large amplitude, it is necessary to reduce the stiffness of the rubber shear spring, which will limit the bearing capacity of the floating screen frame, so it is affected by the stiffness of the rubber shear spring and The mutual restriction of the carrying capacity of the floating screen frame often works at a relatively high frequency, while the traditional crank-link type relaxation screen, according to field experience, generally works at a frequency below 600r/min to achieve better screening results.

The patent document with application number 2014107970494 discloses a vibrating relaxation screen for rapid removal of bulky materials. The floating screen frame and screen body are suspended and installed with rubber hinges. The service life and maintainability are greatly improved compared with rubber shear springs, but the amplitude It is inconvenient to adjust and cannot adapt well to changes in working conditions.

The patent document with the application number 2014203021895 discloses a relaxation screen using a box-type vibrator. Its structure is similar to that of a linear vibrating banana screen. The conveying function can be arranged horizontally, which overcomes the defect of large installation angle of the circular vibrating relaxation screen. However, the box-type vibrator is installed and fixed on the main girder. In order to bear the exciting force generated by the vibrator, the size and weight of the main girder are large, and there is a large structural dead weight and high energy consumption, which is not conducive to vibration relaxation. Large-scale Zhang sieve.

The patent document of application number 2013107281514 proposes a banana relaxation screen without a main beam, which also uses a box-type vibrator. Because the vibrator is directly installed on the top of the side plate of the screen body, the structural weight is reduced. However, due to the concentrated load, in order to ensure the stability of the relaxation screen, the consistency of the excitation force on both sides and the processing accuracy and strength of the side plates are relatively high.

The patent document with the application number 200710019307.6 proposes a super-large vibrating screen with double sets of ultra-statically determinate mesh beams to excite plate-type combined load-bearing beams. Using the ultra-statically indeterminate structure of the mesh beam body as the main beam, it overcomes the defects of the traditional main beam and is suitable for large-scale vibrating screens. However, its main beam structure is fixed and can only achieve a single linear motion.

The patent document with the application number of 2015205282540 discloses a relaxation and screening section type movable beam amplitude adjustment device, which can adapt to the requirements of different working conditions by adjusting the pre-tightening force of the shear rubber spring to change the range of motion of the floating screen frame , limited by the strength of the rubber spring, the amplitude adjustment range is not large. The patent document with the application number 2015203736591 proposes a banana-shaped vibrating relaxation screen with adjustable amplitude in sections. The floating screen frame is divided into multiple sections. According to actual needs, each section can be adjusted independently by removing or replacing the shearing rubber springs of each section. The amplitude of the screen surface is large, but the amplitude can be adjusted by changing the number of rubber blocks, and the stepless adjustment of the amplitude cannot be realized. If the number of dismantling is too large, the bearing capacity of the floating screen frame will often be affected.

To sum up, the main problems of existing relaxation screens are as follows: 1) The use of shearing rubber springs causes the springs to be easily torn, hairy or insufficient in supporting capacity; the stiffness, structure and supporting capacity of shearing rubber springs limit the low-frequency working ability 2 ) It is difficult for the excitation beam to overcome the insufficient rigidity and the complex manufacturing problems caused by the use of box-type exciters in large-span dimensions; 3) The amplitude of the floating screen frame is inconvenient to adjust, and stepless adjustment cannot be achieved, and it often changes The carrying capacity of the floating screen frame. 4) The service life of the vibrating screen surface is short.

Contents of the invention

Technical problem: The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a statically indeterminate modular main beam with simple structure, high reliability, low energy consumption, easy enlargement and good operation stability. Adjust the low frequency vibration relaxation screen.

Technical solution: The ultra-statically definite modular main beam amplitude adjustable low-frequency vibration relaxation screen of the present invention includes a screen body, a spring support seat, a shock-absorbing spring, a motor, a bracket, and an ultra-statically definite excitation screen composed of a pipe beam and a fixed plate. Vibrating the main beam, the screen body is installed on the shock-absorbing spring through the spring support seat, the screen body is provided with a floating screen frame, the screen body and the floating screen frame are provided with an elastic screen surface, and the floating screen frame passes through the rubber The hinge is suspended and installed at the lower part of the screen body, and the floating screen frame can make the polyurethane elastic screen surface swing up and down under the action of the material, so as to speed up the material running speed and avoid load concentration;

The sieve body includes a left side plate, a right side plate, a rear baffle, a plurality of fixed beams and a reinforcing beam connecting the left and right side plates, the plurality of fixed beams are located at the lower part of the sieve body, and the reinforcing beams are located at the upper part of the sieve body. The middle part between the left and right side plates is provided with a statically indeterminate excitation main beam for single or double eccentric mass exciters;

The eccentric block vibrator includes a transmission shaft and a plurality of eccentric blocks arranged on the transmission shaft, and the plurality of eccentric blocks are dispersedly installed on the left and right side plates and the fixed plate inside the hyperstatic excitation main beam. One end of the transmission shaft of the vibrator is connected with the motor installed on the bracket through a coupling;

The floating screen frame includes side beams, floating beams and spring supports, and the two ends of the floating beams are connected to the side beams through flanges to form a frame structure; the floating beams and the fixed beams at the lower part of the screen body are arranged alternately;

The elastic sieve surface includes a plurality of rectangular sieve plates and slot belts. Both sides of the rectangular sieve plate are provided with buckle sides. There are multiple fixed holes at intervals in the middle, and the rectangular sieve plate is buckled together through the slot belts. Each slot belt is respectively installed on the fixed beam and the floating on the beam.

Amplitude limiting springs are installed at the front and rear ends of the side beams of the floating screen frame.

The connection length of the rubber hinges can be adjusted to suit different working conditions by changing the connection lengths of the rubber hinges individually or simultaneously, adjusting the amplitude limit spring stiffness, or changing the working amplitude of the floating screen frame.

The elastic screen surface is polyurethane elastic screen surface.

The heights of the floating beam and the fixed beam are on the same plane, or not on the same level;

The hyperstatic excitation main beam is a circular structural hyperstatic main beam for installing a single set of eccentric mass exciters, or a regular polygonal structural hyperstatic main beam for installing double sets of eccentric mass exciters. Constant excitation of the main beam.

The statically indeterminate excitation main beam of the circular structure is composed of a plurality of circular fixing plates and a plurality of A tube beams, and a concentric hole is respectively opened in the middle of the multiple circular fixing plates, and a plurality of A tube beams form a The rings are evenly distributed and fixed on the circular fixing plate to form a circular mesh beam structure.

The statically indeterminate excitation main beam of the regular polygonal structure comprises a plurality of regular polygonal fixed plates and a plurality of B tube beams, two concentric circular holes are respectively opened on the plurality of regular polygonal fixed plates, and the plurality of B tube beams form a positive The polygons are symmetrically distributed and fixed on the regular polygonal fixed plate to form a regular polygonal mesh beam structure.

Beneficial effects: the present invention can change the dynamic parameters of the vibrating and relaxing screen by changing the rigidity of the metal springs at the front and rear of the floating screen frame and adjusting the connection length of the rubber hinge, thereby steplessly adjusting the working amplitude of the floating screen frame relative to the screen body. Since this adjustment does not change the connection relationship between the floating screen frame and the screen body, the bearing capacity of the floating screen frame will not be reduced. Adjusting the connection length of the rubber hinge will make the floating beam of the floating screen frame and the fixed beam of the screen body be on different levels, while the polyurethane screen plate is respectively fixed on the fixed beam and the floating top beam, thus changing the curved shape of the polyurethane screen plate. Different bending shapes will affect the movement state of the material, which is conducive to adapting to the requirements of different materials or working conditions. In the present invention, the upper part of the left and right side plates of the sieve body is connected by an ultra-static excitation main beam. The left and right side plates and the role of providing exciting force reduce the dead weight of the structure. Under the same excitation force, the scattered installation of the exciter can avoid concentrated load, make full use of the structural rigidity, and prevent local stress concentration. At the same time, the volume of a single exciter can be reduced, and the structure is compact, which meets the requirements of large-scale vibrating screens. The statically indeterminate structure excited main beam can adapt to a wider screen width, which is conducive to the enlargement of the vibrating relaxation screen. According to different process requirements, the tube beam can be retained, and only by replacing the fixed plate with different structures, it can be assembled into different forms of vibration main beams to realize circular vibration excitation or linear vibration excitation, which is flexible and cost-saving.

The floating screen frame is suspended on the lower part of the screen body by using rubber hinges. The rubber hinge endows the floating screen frame with reciprocating swing, which has a large bearing capacity and avoids the problems caused by the general vibrating relaxation screen when the floating screen frame is embedded in the screen body by shearing rubber springs. Rubber fatigue tearing, heating, hard and brittle phenomenon. The amplitude limit springs installed in the front and back of the floating screen frame can effectively restrain the movement of the floating screen frame in other directions, prevent the rubber elements in the rubber hinge from large deformation, and enhance the running stability of the relaxation screen and the life of the elastic parts.

In actual production, the amplitude of the floating screen frame can be flexibly adjusted to meet different process requirements by adjusting the length of the rubber hinge connection part and changing the stiffness of the amplitude limit springs before and after the floating screen frame. The stepless adjustment of the working amplitude of the floating screen frame can be realized without changing its carrying capacity.

In addition, changing the length of the rubber hinge connection can make the floating beam of the floating screen frame and the fixed beam of the screen body on different horizontal planes, thereby changing the curved shape of the polyurethane screen surface, which is conducive to the rolling, collision and disintegration of materials on the polyurethane screen surface. Improve screening efficiency. The polyurethane sieve plate has a non-equal thickness structure, including a connection area, a transition area, and a working area. Different areas adopt different thicknesses and cross-sectional shapes, which can eliminate the stress between the working area and the connecting area of the relaxed screen surface. Concentration phenomenon improves the strength of the screen surface and prolongs the life; both ends are installed on the fixed beam and the floating beam with snap-fit structure, which has simple structure, high reliability, convenient disassembly and assembly, and easy maintenance and repair.

Description of drawings

Fig. 1 is a schematic structural view of Embodiment 1 of the present invention;

Fig. 2 is a schematic structural diagram of Embodiment 2 of the present invention;

Fig. 3 is a schematic diagram of the axonometric structure of the main structure of Fig. 1;

Fig. 4 is a schematic diagram of the axonometric structure of the main structure of Fig. 2;

Fig. 5 is a side view schematic structural diagram of the main structure of Fig. 1;

Fig. 6 is a side view schematic diagram of the main structure of Fig. 2;

Fig. 7 is the axonometric structural diagram of the floating screen frame of the present invention;

Fig. 8 is a schematic axonometric view of the hyperstatically indeterminate modular excitation main beam structure in Fig. 1;

Fig. 9 is a schematic axonometric view of the statically indeterminate modular excitation main beam structure in Fig. 2;

Fig. 10 is a schematic diagram of the buckle fixing method of the screen surface of the present invention;

Fig. 11 is a schematic diagram of the fixing method of the screen surface and the beam of the present invention;

Fig. 12 is a schematic diagram of the slot structure of the present invention;

Fig. 13 is a schematic diagram of a sieve surface of the present invention;

Fig. 14 is a side view of the screen surface of the present invention;

Fig. 15 is a schematic diagram when the floating crossbeam and the fixed crossbeam of the present invention are on the same horizontal plane;

Fig. 16 is a schematic diagram of the present invention when the floating beam and the fixed beam are at different levels.

Detailed ways

The present invention will be further described below in conjunction with the implementation examples in the accompanying drawings:

Embodiment 1, as shown in Figure 1, the ultra-statically indeterminate modular main girder amplitude-adjustable low-frequency vibration relaxation screen of the present invention is mainly composed of a screen body 1, an elastic screen surface 2, a floating screen frame 3, a rubber hinge 4, and an amplitude Limiting spring 5, spring support seat 6, damping spring 7, shaft coupling 8, motor 9, bracket 10 and super static definite excitation main beam are composed. The sieve body 1 is installed on the damping spring 7 through the spring support seat 6, the sieve body 1 is provided with a floating screen frame 3, and the sieve body 1 and the floating sieve frame 3 are provided with an elastic screen surface 2, floating The screen frame 3 is hung and installed on the lower part of the screen body 1 through the rubber hinge 4, and the floating screen frame 3 can make the polyurethane elastic screen surface 2 swing up and down under the action of the material, so as to speed up the material running speed and avoid load concentration; the floating screen frame 3 The front and rear ends of the side beam 3-1 of 3 are equipped with amplitude limiting springs 5, which can be replaced with springs of different stiffnesses as required; the connection length of the rubber hinges 4 can be adjusted by changing the connection length of each rubber hinge 4 individually or simultaneously, and adjusting the amplitude. The stiffness of the spring 5 can change the working amplitude of the floating screen frame to adapt to different working conditions. The statically indeterminate excitation main beam is a regular polygonal structure hyperstatically indeterminate excitation main beam for installing double sets of eccentric mass exciters 11 . The left and right side plates of the screen body 1 and the corresponding positions of the side beams of the floating screen frame are respectively arranged with mounting seats 12 and 13 of rubber hinges. The length of the rubber hinge 4 connecting parts is adjustable.

As shown in Figure 3, the screen body 1 includes a left side plate 1-1, a right side plate 1-5, a rear baffle plate 1-4, a plurality of fixed beams 1-3 connecting the left and right side plates and a reinforcing beam 1 -6, a plurality of fixed beams 1-3 are located at the lower part of the screen body 1, reinforcing beams 1-6 are located at the upper part of the screen body 1, and the middle part between the left and right side plates is provided with two sets of eccentric mass exciters 11 The main beam with ultra-statically indeterminate excitation, and the double sets of eccentric mass exciters rotate in reverse to realize linear vibration excitation.

As shown in Fig. 3 and Fig. 5, the eccentric mass exciter 11 includes two transmission shafts and a plurality of eccentric masses arranged on the two transmission shafts. -1 and the side plate eccentric block 11-1 on the right side plate 1-5 and the internal eccentric block 11-2 dispersedly installed on the fixed plate inside the hyperstatic excitation main beam, the transmission of the eccentric block vibrator 11 One end of the shaft is connected to the motor 9 installed on the bracket 10 through a coupling 8;

As shown in Figure 7, the floating screen frame 3 includes a side beam 3-1, a floating beam 3-2 and a spring support 3-3, and the two ends of the floating beam 3-2 are connected to the side beam 3-1 through flanges , forming a frame structure; gaps are arranged at the lower parts of the left and right side plates 1-1 and 1-5 of the screen body 1, and the floating beams 3-2 of the floating screen frame pass through the gaps and the fixed beams 1-2 at the bottom of the screen body 1 3 are arranged alternately with each other. According to the change of the connection length of the rubber hinge 4, the floating beam 3-2 and the fixed beam 1-3 can be located on different levels in height. The front and rear ends of the side beam of the floating screen frame are equipped with spring supports 3-3, and the spring supports are equipped with springs 5 for adjusting the amplitude, and the other end of the spring is fixed on the spring supports 1-7 of the screen body. The amplitude requirements are different, and the spring 5 can be disassembled or replaced with springs of different rigidities. According to actual needs, in addition to the front and rear ends of the side beams of the floating screen frame, the spring 5 can also be installed between the middle part of the side beams of the floating screen frame and the side plates of the main screen body. The fixed beams and floating beams of the relaxation screen are arranged alternately. In order to facilitate feeding and discharging, the beams at the feeding end and the discharging end of the screen body 1 are all fixed beams.

As shown in Figure 8, the statically indeterminate excitation main beam of regular polygonal structure includes multiple regular polygonal fixed plates 1-2a-2 and multiple B tube beams 1-2a-1, and multiple regular polygonal fixed plates 1-2a-2 is 2-6 pieces, which are set according to the width requirements of the screen body 1, and the fixed plates in the example in the figure are 4 pieces. A plurality of regular polygonal fixed plates 1-2a-2 are respectively provided with two through concentric circular holes, and a plurality of B pipe beams 1-2a-1 are symmetrically distributed in a regular polygon and fixed on a plurality of regular polygonal fixed plates 1-2a- 2, forming a regular polygonal mesh beam structure. All pipe beams are arranged around the eccentric mass exciter 11 to form a cladding structure, and at the same time play the role of connecting the left and right side plates and transmitting the excitation force.

As shown in Figures 10 to 14, the polyurethane screen surface 2 is composed of a plurality of polyurethane rectangular sieve panels, and the two ends of each sieve panel are respectively installed on the fixed beam 1-3 at the bottom of the screen body 1 and the floating screen frame. Floating beam 3-2. The elastic sieve surface 2 includes a plurality of rectangular sieve plates 2-1 and slot belts 2-2, the two sides of the rectangular sieve plate 2-1 are provided with buckle sides, and the two sides of the slot belt 2-2 are provided with rectangular sieve plates. 2-1 The card slots with buckle sides are buckled together, and there are multiple fixing holes at intervals in the middle. The rectangular sieve plate 2-1 is buckled and connected as a whole through the card slot belt 2-2. Each card slot belt 2-2 Backing plate 2-4, layering bar 2-3, bolt 2-6 and antirust nut 2-5 are respectively installed on fixed beam 1-3 and floating beam 3-2. The elastic screen surface 2 is a polyurethane elastic screen surface, and the polyurethane rectangular sieve plate is an overall symmetrical structure, including a connection area, a transition area, and a working area. Different areas adopt different cross-sectional shapes, and the connection area is located at both ends of the sieve plate. The screen surface is connected with the beam, and the working area is the part with screen holes on the screen plate to realize the screening function. The thickness of the connecting area is greater than that of the working area, and the transition area is used to connect the two. The two ends of the sieve plate are installed on the fixed beam 1-3 and the floating beam 3-2 through a buckle structure.

As shown in Fig. 15 and Fig. 16, the height positions of the floating beam 3-2 and the fixed beam 1-3 may or may not be on the same plane.

Embodiment two, shown in Fig. 2, is basically the same as embodiment 1, and the similarities are omitted. The difference: the statically indeterminate excitation main beam described is a circular structure superstatic excitation main beam for installing a single set of eccentric mass exciters 11, and a single set of eccentric mass exciters can realize circular vibration excitation .

As shown in Fig. 4 and Fig. 6, the eccentric mass exciter 11 includes a transmission shaft and a plurality of eccentric masses arranged on the transmission shaft. The side plate eccentric block 11-1 on the plate 1-5 and the internal eccentric block 11-2 dispersedly installed on the fixed plate inside the hyperstatically indeterminate excitation main beam, one end of the transmission shaft of the eccentric block vibrator 11 passes through the coupling The device 8 is connected to the motor 9 installed on the bracket 10; as shown in Figure 9, the circular structure super static excitation main beam is composed of a plurality of circular fixed plates 1-2b-2 and a plurality of A pipe beams 1 -2b-1 constitutes, a plurality of circular fixing plates 1-2b-2 are 2-6 pieces, which are provided according to the width requirements of the box body 1, and the example in the figure is 4 pieces. A concentric hole is opened in the middle of multiple circular fixing plates 1-2b-2, and multiple A pipe beams 1-2b-1 are evenly distributed in a ring and fixed on the circular fixing plate 1-2b-2, forming a circle girder structure. All pipe beams are arranged around the eccentric mass exciter 11 to form a cladding structure.

Working principle: Taking the installation of double sets of eccentric mass exciters as an example, the motor 9 drives the eccentric mass exciters respectively located on the side plate of the screen body 1 and the fixed plate inside the ultra-static excitation main beam to rotate through the elastic coupling , producing linear reciprocating excitation force. The sieve body of the vibrating relaxation sieve makes an approximate linear reciprocating motion relative to the bottom surface. Since the floating screen frame and the screen body are elastically connected by rubber hinges and amplitude adjustment springs, according to the principle of dynamics, under the action of inertial force, elastic force and moment, the floating screen frame 3 swings back and forth with the rubber hinge to periodically interact with the main screen body. Relative movement, so that the floating crossbeam installed on the floating screen frame and the fixed crossbeam of the screen body 1 are periodically "closer" - "far away" - "closer". Since the two ends of the polyurethane elastic sieve plate 2 are respectively fixed on the fixed beam 1-3 and the floating beam 3-2, the entire screen surface is periodically relaxed-tensioned-relaxed in each area driven by the beam, thereby realizing the relaxation movement , resulting in higher throwing acceleration and greater mesh deformation, preventing the accumulation and adhesion of wet fine-grained materials.

Claims (8)

1. An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen, including a screen body (1), a spring support seat (6), a damping spring (7), a motor (9), and a bracket (10) , the statically indeterminate excitation main beam composed of pipe beams and fixed plates, the screen body (1) is installed on the shock absorbing spring (7) through the spring support seat (6), it is characterized in that: the screen The body (1) is provided with a floating screen frame (3), the screen body (1) and the floating screen frame (3) are provided with an elastic screen surface (2), and the floating screen frame (3) is suspended and installed through a rubber hinge (4). In the lower part of the screen body (1), the floating screen frame (3) can make the polyurethane elastic screen surface (2) swing up and down under the action of the material, so as to speed up the material running speed and avoid load concentration; The sieve body (1) includes a left side plate (1-1), a right side plate (1-5), a rear baffle (1-4), and a plurality of fixed beams (1-3 ) and reinforcement beams (1-6), multiple fixed beams (1-3) are located at the bottom of the screen body (1), reinforcement beams (1-6) are located at the top of the screen body (1), and the left and right side panels The middle part of the room is provided with an ultra-static excitation main beam for single or double sets of eccentric mass exciters (11); The eccentric mass exciter (11) includes a transmission shaft and a plurality of eccentric masses arranged on the transmission shaft, and the plurality of eccentric masses are dispersedly installed on the left and right side plates and the fixed plate inside the hyperstatic excitation main beam, One end of the transmission shaft of the eccentric mass exciter (11) is connected with the motor (9) installed on the bracket (10) through a coupling (8); The floating screen frame (3) includes side beams (3-1), floating beams (3-2) and spring supports (3-3), and the two ends of the floating beams (3-2) The beams (3-1) are connected to form a frame structure; the floating beams (3-2) and the fixed beams (1-3) at the lower part of the screen body (1) are arranged alternately; The elastic sieve surface (2) includes a plurality of rectangular sieve plates (2-1) and slot belts (2-2), and the two sides of the rectangular sieve plate (2-1) are provided with buckle sides, so The two sides of the above-mentioned slot belt (2-2) are provided with slots that are fastened with the buckle side of the rectangular sieve plate (2-1), and a plurality of fixing holes are arranged at intervals in the middle, through which the slot belt (2-2) ) to fasten the rectangular sieve plate (2-1) into one, and each slot belt (2-2) passes through the backing plate (2-4), bead (2-3), bolt (2-6) and antirust Nuts (2-5) are installed on the fixed beam (1-3) and the floating beam (3-2) respectively. 2. An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen according to claim 1, characterized in that: the side beams (3-1) of the floating screen frame (3) have two front and rear sides A limit spring (5) for amplitude adjustment is installed at the end. 3. An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen according to claim 1, characterized in that: the connection length of the rubber hinges (4) can be changed individually or simultaneously (4) Adjust the length of the connection, adjust the amplitude, adjust the spring (5) stiffness, or change the working amplitude of the floating screen frame to adapt to different working conditions. 4. An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen according to claim 1, characterized in that: the elastic screen surface (2) is polyurethane elastic screen surface. 5. An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen according to claim 1, characterized in that: the floating beam (3-2) and the fixed beam (1-3) Heights are on the same plane, or not on the same level. 6. An ultra-statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen according to claim 1, characterized in that: the ultra-statically indefinite excitation main beam is used to install a single set of eccentric block excitation The circular structure hyperstatic excitation main beam of the vibrator (11), or the regular polygonal structure hyperstatic excitation main beam used for installing double sets of eccentric block vibrators (11). 7. A statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen according to claim 6, characterized in that: the circular structure of the statically indeterminate exciting vibration main beam is fixed by a plurality of circular Plates (1-2b-2) and multiple A tube beams (1-2b-1), multiple circular fixed plates (1-2b-2) have a concentric hole in the middle, and multiple A tubes The beams (1-2b-1) are evenly distributed in a ring and fixed on the circular fixing plate (1-2b-2), forming a circular mesh beam structure. 8. A statically indeterminate modular main beam amplitude-adjustable low-frequency vibration relaxation screen according to claim 6, characterized in that: said regular polygonal structure hyperstatically indeterminate excitation main beam comprises a plurality of regular polygonal fixed plate (1-2a-2) and a plurality of B pipe beams (1-2 a-1), two concentric holes are respectively opened on a plurality of regular polygonal fixed plates (1-2a-2), and a plurality of B pipe beams (1-2a-1) The pipe beams (1-2a-1) are symmetrically distributed in a regular polygon and fixed on the regular polygonal fixing plate (1-2a-2), forming a regular polygonal mesh beam structure.