Flexible collaborative screening device and method for cut stems

Abstract

The invention discloses a flexible collaborative screening device and method for cut stems, and belongs to the technical field of tobacco processing equipment. The device comprises a rack, a screen body and a vibration exciter for driving the screen body to generate main vibration, wherein the screen body is arranged on the rack through a rocker arm. An independent flexible screening unit is further arranged on the screen body and flexibly connected with the screen body through a plurality of elastic connecting pieces arranged at intervals. The device further comprises a cooperative excitation mechanism, and the actuating end of the cooperative excitation mechanism directly acts on the flexible screening unit to drive the flexible screening unit to generate additional vibration or motion independent of main vibration of the screen body. The problems that a traditional rigid screen surface is prone to being blocked and the screening dimension is single are effectively solved, and the screening efficiency, the finished product homogenization level and the equipment operation stability are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tobacco processing equipment, and particularly relates to a flexible and collaborative screening device for stem shreds and a method thereof. BACKGROUND

[0002] In the structure of a cigarette product, stem shreds are not simply a filler material, but a functional component that directly affects the physical quality of a cigarette. It needs to provide structural support for a cigarette to maintain its hardness and appearance, has coordinated combustion characteristics with leaf shreds to ensure uniform combustion, and can be uniformly mixed in processing to ensure consistent quality. Excessive size can damage the uniformity of mixing and the combustion rate, while too small size can weaken the structural support and affect the combustion state. Therefore, strict control of the size of stem shreds and the uniformity thereof are the physical basis for achieving the above-mentioned comprehensive process performance, which also makes the screening process after drying and shaping of stem shreds a key quality control link.

[0003] Currently, the mainstream technology for screening stem shreds after drying and shaping in a cigarette silk production line is a mechanical vibration screening device based on a rigid screen surface. This technical solution is usually composed of one or two layers of metal screen with fixed aperture, a mechanical mechanism for providing reciprocating vibration, and a driving system. Its working principle relies on the rigid contact and geometric interference between the screen and the stem shreds, that is, under the action of vibration, the smoke powder with a size smaller than the screen hole is separated by screening, and the qualified stem shreds are conveyed to the subsequent process as the screen material.

[0004] However, with the increasing requirement for the homogenization of the physical quality of cigarettes, this inherent mode based on rigid contact and static geometric separation gradually shows its technical inadaptability when dealing with stem shreds with specific physical characteristics (such as a certain moisture content, flexibility and surface friction coefficient). The moisture content and flexibility retained by the post-drying stem shreds make them prone to undesirable deformation, adhesion, or multiple stem shreds interweaving and "arched" on the screen hole during the vibration process of the rigid screen surface, resulting in screen hole blockage. This blockage is not accidental, but occurs continuously and accumulates with running time, causing irreversible loss of effective screening area and continuous decline of screening efficiency, which seriously restricts the continuity of production. More importantly, the fixed and rigid screening interface can only roughly separate the materials according to their length and width on the screen surface, and cannot distinguish those materials with similar length and width but large difference in thickness. As a result, large pieces or twisted stem shreds that do not meet the requirements, or materials that meet the length and width requirements but do not meet the thickness requirements, may be mixed into the qualified products. In addition, from the perspective of the device itself, the maintenance inconvenience caused by the fixed structure of the rigid screen, as well as the fatigue and deformation under long-term vibration, also makes it difficult to maintain the screening accuracy for a long time, increases the maintenance cost and affects the process stability.

[0005] In essence, this inherent mode is a kind of plane size screening. It can only make judgments according to the length and width of the material (i.e. two-dimensional plane size), and completely cannot respond to the thickness (i.e. three-dimensional characteristics) that determines its process value. Therefore, for the cut tobacco that is similar in length and width, but different in thickness (such as thin pieces and thick blocks) or form (such as flat and winding), the existing technology is difficult to achieve effective separation.

[0006] To solve the above problems, the present application is proposed. SUMMARY

[0007] In view of the problems of screen hole blockage caused by material adhesion and bridging due to the rigidity of the screen surface in the existing cut tobacco screening technology, and the limitation of single screening dimension and the inability to effectively separate the material according to its three-dimensional form, the present application provides a cut tobacco flexible collaborative screening device and method. The purpose of the present application is to construct a dynamic, multi-dimensional composite screening force field by setting flexible screening units that can vibrate independently and combining with a collaborative excitation mechanism. This scheme aims to actively remove screen hole blockage and achieve differentiation of multi-dimensional characteristics such as material thickness and form, thereby improving screening efficiency and long-term operation stability.

[0008] The technical scheme adopted by the present application is as follows:

[0009] The present application provides a cut tobacco flexible collaborative screening device in a first aspect, comprising a rack 1, a screen body 2, and an excitation vibrator for driving the screen body 2 to generate main vibration. The screen body 2 is installed on the rack 1 through a rocker arm 3. The screen body 2 is provided with independent flexible screening units. The flexible screening units are connected to the screen body 2 through a plurality of spaced elastic connecting pieces 4.

[0010] The device further comprises a collaborative excitation mechanism. The actuating end of the collaborative excitation mechanism directly contacts or connects to the flexible screening units, and is used to drive the flexible screening units to generate additional vibration or motion independent of the main vibration of the screen body 2.

[0011] Preferably, the flexible screening unit comprises a screen frame 5 and a working surface 6 laid and fixed on the screen frame 5. The screen frame 5 is connected to the screen body 2 through the elastic connecting pieces 4. The working surface 6 is a screen plate or screen mesh that can elastically vibrate or fluctuate under the drive of the collaborative excitation mechanism.

[0012] Preferably, the collaborative excitation mechanism comprises a drive source and an actuating part. The actuating part is arranged below the working surface 6 and periodically pushes the back surface of the working surface 6 upwards, so that the working surface 6 produces a bouncing motion.

[0013] Preferably, the synergic vibration excitation mechanism is a gas flow pulse mechanism, which comprises a gas source and a plurality of nozzles 13; the plurality of nozzles 13 are arranged on the side wall of the screen body 2, and the nozzle outlets are arranged obliquely towards the back of the working surface 6, for spraying periodic pulse gas flow to the working surface 6 upwards.

[0014] Preferably, the number of flexible screen units is two, and the upper one is the upper screen unit 14 and the lower one is the lower screen unit 15, and the screen hole sizes of the two are different; the acting end of the synergic vibration excitation mechanism acts on the lower screen unit 15.

[0015] Preferably, the screen body 2 further comprises a bottom plate 16, which is connected with the side wall of the screen body 2 to form a U-shaped or box-shaped structure with an upward opening; the flexible screen unit is arranged in the U-shaped structure, and the bottom plate 16 is located below the flexible screen unit.

[0016] Preferably, a tobacco tar collecting box 17 is further included, which is connected with the discharge port of the bottom plate 16.

[0017] Preferably, the working surface 6 of the upper screen unit 14 comprises a screening area in the middle and a non-porous flow guide groove 18 on at least one side edge thereof; the groove bottom of the non-porous flow guide groove 18 is lower than the plane of the screening area, and together with the side wall of the screen body 2, defines a material channel towards the lateral outlet.

[0018] Preferably, the elastic connecting piece 4 is a coil spring or a rubber bushing, and the two ends thereof are connected with the screen frame of the flexible screen unit and the side wall of the screen body 2, respectively.

[0019] The second aspect of the present application provides a flexible synergic screening method for cut tobacco, which adopts the device as described in the first aspect, and comprises the following sequential steps: S1, feeding and conveying cut tobacco material to the upper screen unit 14; under the combined action of the main vibration of the screen body and the elastic deformation of the screen surface induced thereby, performing primary processing, wherein:

[0020] a) cut tobacco and hard blocks with two-dimensional size too large to pass through the screen, are discharged from the main flow outlet at the front end of the screen surface under the main vibration;

[0021] b) sheet-shaped cut tobacco with two-dimensional projection size that can pass through the screen, in a flat and light texture form, is separated from the movement track under the action of the dynamic elastic deformation of the screen surface, so as to enter the non-porous flow guide groove 18 on the side edge and be discharged through the lateral outlet;

[0022] c) the rest of the qualified material falls through the screen holes of the upper screen unit 14; S2, the falling material is scattered on the lower screen unit 15; under the action of the main vibration of the screen body, secondary screening is carried out, and the airflow pulse mechanism as claimed in claim 4 is started synchronously, so that the working surface 6 of the lower screen unit 15 is subjected to periodic upward pulse airflow impact to generate elastic fluctuation; S3, at the lower screen unit 15, the main vibration and the elastic bouncing movement caused by the pulse airflow impact are coordinated to form a dynamic three-dimensional screening force field, wherein:

[0023] a) the qualified stem as the oversize is transported to the qualified product outlet;

[0024] b) the fine tobacco dust falls through the screen holes of the lower screen unit, is collected by the bottom plate 16 and is finally introduced into the tobacco dust collection box 17.

[0025] The beneficial effects of the present application relative to the prior art are as follows:

[0026] 1. In view of the efficiency decay caused by blockage in stem screening and the demand for product homogenization, the present application realizes overall optimization through the differential and coordinated design of the upper and lower screen units. The upper screen unit has larger screen holes and processes materials containing components with larger size and weight. Under the combined action of the elastic deformation of the flexible screen surface itself and the main vibration, large-inertia materials can be efficiently transported, and flat sheet materials are also easy to be guided to the lateral outlet, so the risk of screen surface blockage is low. Therefore, the main vibration alone can complete the task of rapid classification and separation. The lower screen unit processes finer materials with larger specific surface area and is more prone to adhesion and bridging. Therefore, a coordinated vibration excitation mechanism is specially configured to actively destroy the blockage structure by generating additional elastic fluctuation, thereby realizing dynamic self-cleaning and stable screening at this level. Based on the characteristics of the materials and process requirements, the upper and lower layers respectively adopt the modes of independent action of the main vibration and coordinated action of the main vibration and additional excitation, which together constitute an efficient screening system that can prevent blockage and realize three-dimensional separation, thereby significantly improving the screening efficiency and continuity as a whole.

[0027] 2. In the vibration separation of traditional rigid screen surfaces, the materials are mainly screened according to their projection size (length and width) on the screen plane. For stem with obviously thin thickness but still within the qualified range when laid flat, this method is difficult to achieve effective separation.

[0028] Therefore, the present application adopts a flexible screen surface design. Under the drive of the main vibration system, combined with the deformation of the screen surface itself and the elastic connecting member, the screen surface will produce wave fluctuations, so that the originally static screening interface is changed into a continuously changing dynamic wave interface. In this environment, the separation mechanism of the materials has fundamentally changed.

[0029] The stem with large thickness or rigidity has large mass and inertia, and mainly keeps in contact state during the wave fluctuation of the screen surface, and is not easy to be thrown away. In the "sliding" mode, the material is subjected to the combined action of the wave guidance of the screen surface and the sliding friction force, and is conveyed forward along a relatively stable path. In this process, the part meeting the requirements of three-dimensional size (including thickness) will be sequentially classified and collected through the pre-set screen hole; and the material with size too large or shape not meeting the requirements will continue to be conveyed along the screen surface to the specific outlet downstream for centralized discharge.

[0030] The stem with light and soft texture is easy to enter the "throwing" state on the dynamic screen surface due to small mass and inertia. After being thrown, the material collides with the inclined wave that is swinging transversely when falling back to the screen surface, and the randomness of the movement direction increases, which is easy to produce transverse bouncing and deviation, and thus disperses laterally under the movement of the screen surface.

[0031] Through the above separation mechanism based on the interaction between the thickness, rigidity of the material and the wave of the dynamic screen surface, the system can effectively screen out the thin stem that does not meet the thickness requirement while ensuring that the stem with qualified shape and size is classified and collected, thereby improving the accuracy and process rationality of the overall screening.

[0032] 3. In view of the reliability and maintenance requirements of the dynamic screening system composed of the flexible screen surface and the elastic connecting piece in long-term operation, the design of the present application also improves the stability of the equipment and the adaptability of the process.

[0033] Since the screen surface is made of flexible material and coupled with the elastic connecting piece, the system can effectively buffer and disperse stress through its own deformation when subjected to continuous vibration, reducing the risk of fatigue fracture commonly caused by rigid connection, thereby prolonging the service life of the key components. At the same time, when the screen surface is worn or needs to be cleaned, the structure can be more conveniently replaced or maintained locally, reducing downtime and maintenance costs.

[0034] In addition, by adjusting the main vibration parameters or coordinating the action of the excitation mechanism, the amplitude, frequency and propagation direction of the screen surface wave can be adjusted within a certain range, so that the same equipment can adapt to stem materials with different moisture contents, batches or process requirements, enhancing the flexibility and stability of the overall production line.

[0035] 4、In the present application, the movement of the flexible screen surface under the vibration drive is not a simple overall rigid body movement. Due to the elasticity of the screen surface material and the coupling with the elastic connecting piece, the elastic working surface will have complex micro-bending and torsional deformation locally while generating macroscopic wave fluctuations. When the cut stem with a certain moisture content and surface adhesion is attached to the screen surface, this dynamic and non-uniform local deformation causes the forces acting on the material at different parts of the screen surface at the same time to differ in size and direction. This differential force continues to act, which essentially forms a repeated "rubbing" effect similar to a rubbing board effect on the material. This effect can effectively overcome the surface adhesion of the cut stem due to moisture content and flexibility, and destroy the adhesion between them and the bridging tendency on the screen hole, which is the internal physical mechanism for realizing dynamic self-cleaning and maintaining the smoothness of the screen hole. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0037] Figure 1 A perspective structural schematic view of an embodiment of the cut stem flexible cooperative screening device of the present application;

[0038] Figure 2 A perspective structural schematic view of an embodiment of the cut stem flexible cooperative screening device of the present application; Figure 1 A structural schematic view of the flexible screening unit and the screen body connected through the elastic connecting piece in the embodiment;

[0039] Figure 3 A sectional view of the upper screening unit;

[0040] Figure 4 A flow schematic view of an embodiment of the cut stem flexible cooperative screening method of the present application;

[0041] The drawings show that: 1 is a rack; 2 is a screen body; 3 is a rocker arm; 4 is an elastic connecting piece; 5 is a screen frame; 6 is a working surface; 13 is a nozzle; 14 is an upper screening unit; 15 is a lower screening unit; 16 is a bottom plate; 17 is a tobacco tar collection box; 18 is a non-porous flow guide groove; 19 is a lateral outlet; 20 is a main flow outlet; 21 is a qualified product outlet. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0043] Example 1

[0044] like Figures 1-3 As shown, the device includes a frame 1, a screen body 2, a vibrator that drives the screen body 2 to generate main vibration, and a rocker arm 3. The screen body 2 (with an inclination angle) is mounted on the frame 1 via the rocker arm 3. Those skilled in the art will understand that the vibrator (e.g., a rotary eccentric block vibrating motor) can drive the entire screen body 2 to generate reciprocating vibration in order to complete the conventional screening and conveying of materials.

[0045] The present invention includes at least one independent flexible screening unit within the screen body 2. This flexible screening unit is not rigidly fixed to the screen body 2, but is flexibly connected via multiple spaced elastic connectors 4. Specifically, as shown... Figure 2 As shown, the elastic connector 4 is preferably a helical spring or a rubber damping bushing, and there are at least four of them, which are respectively arranged at the four corners of the screen frame 5 of the flexible screening unit or evenly distributed along its long side. The two ends of the elastic connector 4 are respectively connected to the screen frame 5 of the flexible screening unit and the side wall or internal support of the screen body 2. This arrangement allows the flexible screening unit to obtain additional, locally independent degrees of freedom of motion under the main vibration framework of the screen body 2.

[0046] It should be noted that the screen frame is made of highly elastic and wear-resistant rubber or polyurethane material through a molding process to form an integral frame, thereby realizing the elastic deformation capability of the screen frame itself, so that it can work together with the working surface (screen mesh or screen plate) fixed on it to generate an overall elastic fluctuation.

[0047] The flexible screening unit further includes a screen frame 5 and a working surface 6 laid and tensioned and fixed on the screen frame 5. The working surface 6 is a key component that directly contacts the filamentous material and performs the screening function. In this invention, the working surface 6 is defined as an elastic working surface, specifically referring to a screen plate or screen mesh made of a material with good elastic recovery capability. For example, thin steel plates (such as 65Mn spring steel) can be punched to form a corrugated or flat screen plate with a certain pretension, or a screen mesh woven from high-carbon steel wire can be used. It is understood that the working surface 6 can also be made of other materials that can achieve similar elastic vibration functions. Its elastic characteristics are reflected in: 1) the material itself has an elastic modulus and can undergo recoverable deformation; 2) when subjected to external excitation (such as the coordinated excitation described later), its local area (such as the area of ​​the filaments or screen plate between two fixed points) can produce micro-amplitude elastic vibrations or fluctuations such as bending and torsion, rather than being translated as a rigid body as a whole.

[0048] To achieve a more proactive anti-blocking mechanism, the device also includes a coordinated excitation mechanism. For example... Figure 2As shown, in this embodiment, the coordinated vibration mechanism is preferably an airflow pulse mechanism. It includes an air source (such as an air compressor and pulse valve assembly) and multiple nozzles 13 disposed on the side wall of the screen body 2. The nozzles 13 preferably correspond to the opposite position of the working surface 6 of the lower screen unit 15. The outlets of these nozzles 13 are inclined toward the back of the working surface 6, and periodically spray high-intensity pulsed airflow onto the screen surface in a certain sequence (direction shown by arrow B in the figure). This pulsed airflow impacts the back of the working surface 6 at a certain angle, causing a rapid and violent compound bounce and slight twisting in a localized area, thereby forcefully shaking off the material clogging the screen holes and destroying the "bridging" structure.

[0049] In a preferred configuration, such as Figure 3 As shown, there are two flexible screening units, arranged vertically and alternately to form an upper screening unit 14 and a lower screening unit 15. The upper screening unit 14 has larger screen holes to remove oversized stems and hard lumps; the lower screening unit 15 has smaller screen holes to separate qualified stems from fine dust. The coordinated vibration mechanism mainly acts on the lower screening unit 15, which is more prone to clogging. The working surface 6 of the upper screening unit 14 can be functionally divided, with a conventional screening section in the middle and a non-perforated guide channel 18 on at least one long side. The bottom of the guide channel 18 is formed by stamping or welding, and its plane is lower than the plane of the screening section, thus naturally forming a channel with the side wall of the screen body 2 to guide a lateral outlet 19 for collecting and discharging the separated flat, thin stems.

[0050] The bottom of the screen body 2 is provided with a bottom plate 16, which forms an upward-opening U-shaped structure with the side wall to receive the smoke droplets falling from the lower screen holes. The discharge port of the bottom plate 16 is connected to a smoke droplet collection box 17 to complete the collection of waste materials.

[0051] Example 2

[0052] This embodiment provides a flexible co-sieving method for filaments using the device described in Embodiment 1. By operating the device, the main vibration of the screen body, the dynamic elastic deformation of the flexible screen surface, and the high-frequency excitation generated by the co-vibration work together to construct a dynamic three-dimensional sieving force field, thereby achieving efficient anti-clogging and sorting by thickness.

[0053] The method includes the following sequential steps:

[0054] S1. The dried shredded material is fed into the operating device and conveyed to the upper screen unit 14. Driven by the main vibration of the screen body 2, the material moves on the screen surface. At the same time, since the working surface 6 of the upper screen unit 14 is flexible, the main vibration will induce it to produce accompanying elastic undulation deformation.

[0055] For filaments and hard lumps that are too large in two dimensions (length and width), they cannot pass through the upper screen holes and are discharged from the main outlet 20 along the screen surface under the conveying action of the screen surface.

[0056] For sheet-like filaments that meet the two-dimensional projection size requirements but are too thin and have a soft texture, their motion behavior undergoes a key change. Due to their light weight and low inertia, they are more likely to couple with the dynamically undulating elastic screen surface, resulting in unstable bouncing or lateral sliding. Their motion trajectory deviates from the main conveying direction, thus being guided into the non-porous guide channel 18 on the side and finally discharged from the side outlet 19. This process achieves the separation of thin materials that do not meet the thickness requirements.

[0057] The remaining filaments that are of acceptable size and shape fall through the sieve holes of the upper sieve unit 14 to the lower sieve unit 15.

[0058] S2. The material falling from step S1 is evenly distributed on the working surface 6 of the lower screen unit 15. At this time, the main vibration of the screen body continues to act, causing the material to be initially dispersed. The coordinated excitation mechanism, namely the airflow pulse mechanism, is started simultaneously. The air source and pulse valve are opened, so that the nozzles 13 arranged in an array on the side wall of the screen body 2 spray periodic high-intensity pulsed airflow (direction as shown) onto the back of the working surface 6 of the upper lower screen unit 15 at a set frequency and pressure. Figure 3 (As indicated by the middle arrow B).

[0059] S3. At the lower sieve unit 15, the main vibration and the local high-frequency elastic fluctuation of the sieve surface caused by the pulse airflow impact work together to form a composite sieve force field that is non-uniform in both space and time.

[0060] In this dynamic force field:

[0061] Wire strands that meet the required shape and size (including thickness) mainly maintain a "sliding" state due to their large mass and inertia. Based on the macroscopic conveying provided by the oscillation and tilt angle of the screen body, they are further stabilized and combed by the dynamic waveform screening interface of this invention, thus being accurately conveyed to the qualified product outlet 21.

[0062] The fine smoke particles, due to the intense local bouncing, are more likely to pass through the lower sieve holes, fall into the bottom plate 16, and eventually flow into the smoke collection box 17.

[0063] At the same time, the dynamic effect generated by the combined impact of the pulsed airflow and the ripples on the screen surface constitutes the real-time self-cleaning mechanism at this level:

[0064] High-frequency pulsed airflow directly impacts the back of the screen holes and the material adhering to the screen surface, providing the direct force required for peeling.

[0065] The resulting localized high-frequency elastic fluctuations on the screen surface cause continuous, minute relative displacement and misalignment friction between the material and the screen mesh, as well as between the materials themselves. This effect essentially applies a mechanical "kneading" and "combing" action to the adhered material clumps.

[0066] The combined effect of "impact" and "kneading" effectively overcomes the surface adhesion caused by the moisture content of the stems, breaks down the "bridging" structure formed by the slender stems at the screen openings, and disperses material clumps formed by static electricity or entanglement. As a result, the screen openings remain unobstructed throughout the screening process, achieving dynamic and proactive anti-clogging.

[0067] Real-time dynamic self-cleaning: The high-frequency fluctuations in the working surface 6 caused by pulsed airflow continuously "rub" the filaments with specific moisture content and viscosity that are attached to it. This rapid, slight local deformation effectively disrupts the adhesion and bridging tendency between materials and between materials and screen holes, achieving real-time anti-clogging during the screening process and ensuring long-term stability of screening efficiency.

[0068] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, alterations, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A flexible co-processing sieving device for stems and fibers, comprising a frame (1), a sieve body (2), and an exciter for driving the sieve body (2) to generate main vibration, wherein the sieve body (2) is mounted on the frame (1) via a rocker arm (3), characterized in that, The screen body (2) is provided with independent flexible screening units, which are connected to the screen body (2) through a plurality of spaced elastic connecting pieces (4); The device further comprises a cooperative excitation mechanism, the actuating end of which directly contacts or is connected to the flexible screening unit, for driving the flexible screening unit to generate additional vibration or movement independent of the main vibration of the screen body (2).

2. The cut-filler flexible co-sifting device according to claim 1, wherein, The flexible screening unit comprises a screen frame (5) and a working surface (6) laid and fixed on the screen frame (5); the screen frame (5) is connected to the screen body (2) through the elastic connecting piece (4); and the working surface (6) is a screen plate or screen mesh capable of being elastically vibrated or waved under the driving of the cooperative excitation mechanism.

3. The cut-filler flexible co-sifting device according to claim 2, wherein, The cooperative excitation mechanism comprises a driving source and an actuating part, the actuating part being arranged below the working surface (6) and periodically pushing the back surface of the working surface (6) upward, so that the working surface (6) generates a bouncing movement.

4. The cuttle flexible synergic screening device according to claim 2 or 3, characterized in that, The cooperative excitation mechanism is a gas flow pulse mechanism, which comprises a gas source and a plurality of nozzles (13); the plurality of nozzles (13) are arranged on the side wall of the screen body (2), and the nozzle outlets thereof are obliquely arranged towards the back surface of the working surface (6), for spraying periodic pulse gas flow to the working surface (6) upward.

5. The cut-filler flexible co-sifting device according to claim 1, wherein, The number of the flexible screening units is two, which are arranged in an upper-lower spaced manner, the upper one being an upper screening unit (14) and the lower one being a lower screening unit (15), and the screen hole sizes of the two are different; and the actuating end of the cooperative excitation mechanism acts on the lower screening unit (15).

6. The cut-filler flexible co-sifting device according to claim 1 or 5, wherein, The screen body (2) further comprises a bottom plate (16) connected to the side wall of the screen body (2), which together form a U-shaped or box-shaped structure with an upward opening; the flexible screening unit is arranged in the U-shaped structure, and the bottom plate (16) is located below the flexible screening unit.

7. The cut-filler flexible co-sifting device according to claim 6, wherein, A tobacco tar collecting box (17) is further included, which is connected to the discharge port of the bottom plate (16).

8. The cut-filler flexible co-sifting device according to claim 5, wherein, The working surface (6) of the upper screening unit (14) comprises a screening zone located in the middle and a non-hole flow guide groove (18) located on at least one side edge thereof; the groove bottom of the non-hole flow guide groove (18) is lower than the plane of the screening zone, and together with the side wall of the screen body (2) defines a material channel towards the lateral outlet.

9. The cut-filler flexible co-sifting device according to claim 1, wherein, The elastic connecting piece (4) is a spiral spring or a rubber bushing, the two ends of which are respectively connected to the screen frame of the flexible screening unit and the side wall of the screen body (2).

10. A flexible and synergic screening method of cut stem, using the device as claimed in claim 1, characterized in that, The method comprises the following sequential steps: S1, the stem material is put into and conveyed to the upper screening unit (14); under the combined action of the screen body main vibration and the elastic deformation of the screen surface induced thereby, the primary processing is carried out, wherein: a) the stem filaments and hard blocks with two-dimensional size too large cannot pass through the screen and are discharged from the main flow outlet at the front end of the screen surface under the main vibration; b) the sheet-shaped stem filaments with two-dimensional projection size capable of passing through the screen in a flat and light and thin form move along the motion track under the dynamic elastic deformation of the screen surface, so as to enter the non-hole flow guide groove (18) on the side edge and be discharged through the lateral outlet; c) the rest of the qualified material falls through the screen holes of the upper screen unit (14); S2, the falling material is scattered on the lower screen unit (15); under the action of the main vibration of the screen body, secondary screening is carried out, and the air flow pulse mechanism as claimed in claim 4 is started synchronously, so that the working surface (6) of the lower screen unit (15) is impacted by the periodic upward pulse air flow to generate elastic fluctuation; S3, at the lower screen unit (15), the main vibration and the elastic bouncing movement caused by the impact of the pulse air flow are coordinated to form a dynamic three-dimensional screening force field, wherein: a) the qualified stem as the oversize is conveyed to the qualified product outlet; b) the fine tobacco dust falls through the screen holes of the lower screen unit, is collected by the bottom plate (16) and is finally introduced into the tobacco dust collection box (17).

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