Sand and gravel screening device

Abstract

A sand and gravel screening device comprises a support, a driving assembly, a screening sleeve and a discharging assembly. The support is a frame structure and is provided with a supporting wheel. The driving assembly comprises a motor and a driving shaft. The driving shaft is respectively connected to the motor and one or two front and rear supporting wheels located on the same side of the support. The screening sleeve comprises an inner cylinder, a rotating flange ring and at least one outer cylinder. The outer cylinder is mounted outside the inner cylinder in a set manner. The inner cylinder is a cylindrical grille structure. The outer cylinder is a cylindrical screen structure. The apertures of the respective screens of the outer cylinders mounted outside the inner cylinder gradually decrease from the inside to the outside. The screen aperture of the innermost inner cylinder is smaller than the spacing width of the inner cylinder grille. The screening sleeve is placed on the supporting wheel through a rotating flange ring. The discharging assembly is composed of a discharging guider stacked in layers. The present invention drives the driving shaft to rotate through the rotation of the motor and then drives the supporting wheel and the screening sleeve to rotate, so as to realize multiple screening of sand and gravel raw materials, significantly improve the efficiency, and has a simple structure, convenient manufacture, use and transportation.

Description

Technical Field

[0001] The invention relates to a sand and gravel screening device, belonging to the technical field of production and manufacturing of building construction devices. Background Art

[0002] Sand and gravel are basic materials for construction. However, the sand and gravel usually transported to the construction site or concrete mixing plant needs to be screened to meet the different needs of construction for sand and gravel particle size.

[0003] Sand and gravel screening is usually carried out by using a sand and gravel screening device. For this purpose, there are different types of sand and gravel screening devices in the prior art that solve different technical problems, such as:

[0004] The utility model patent (application number 201721806224.7) provides a "sand and gravel screening device for construction engineering" to solve the problem in the prior art that the screening process is dusty, easily causing discomfort to the human body, and there is no subsequent cleaning of the equipment itself;

[0005] The utility model patent (application number 201820797623.X) provides a sand and gravel screening device for construction, which is simple and practical in structure, reduces the occupied space, is easy to move, saves time and effort, is energy-saving and environmentally friendly, and reduces the labor level;

[0006] The invention patent application (application number 201810780048.7) provides a "construction sand and gravel screening device and screening method", which can filter and separate two sand and gravel with different particle sizes, and facilitate collection after separation;

[0007] The utility model patent (application number 201921031965.1) provides a "sand and gravel screening device for construction", which can achieve better sand and gravel screening effects, avoid repeated operations, reduce manual labor, and improve screening efficiency;

[0008] The "Sand and Gravel Screening Device for Construction" provided by the utility model patent (application number 201721918085.7) solves the problem of uneven screening of existing sand and gravel screening devices for construction.

[0009] By examining the above prior art, it can be seen that:

[0010] The sand and gravel screening device in the prior art can usually only perform sand and gravel screening once. When a sand and gravel screening device of one specification and model is in operation, it can usually only obtain sand and gravel of two particle specifications, and it is impossible to perform screening twice or more at the same time. The efficiency is relatively low, and the particle size of the sand and gravel particles is relatively wide, which cannot meet the requirements of refined construction;

[0011] In addition, the sand and gravel screening devices in the prior art are often complex in structure, heavy in weight, and difficult to carry. Moreover, the fine sand after screening often falls directly to the bottom of the sand and gravel screening device, which not only affects the screening efficiency, but also affects the cleaning and transportation.

[0012] In addition, the rotating shaft of the screening mechanism of some sand and gravel screening devices is directly connected to the driving motor, which makes it difficult to operate the sand and gravel screening device and to perform subsequent maintenance. Summary of the invention

[0013] In order to overcome the shortcomings of the existing related technologies, the embodiments of the present invention provide a sand and gravel screening device, the purpose of which is:

[0014] Multiple screenings are performed on construction sand and gravel at one time to obtain sand and gravel materials with more than three particle size specifications to meet the needs of construction and improve screening efficiency. At the same time, the device structure is simplified, maintenance and transportation are convenient, the service life of the device is extended, and labor intensity is reduced.

[0015] To achieve the above object, the present invention provides a sand and gravel screening device for screening sand and gravel for construction, comprising:

[0016] Support, drive assembly, screening sleeve and discharge assembly;

[0017] The support is a frame-type structure, and support wheels are respectively arranged on both sides of the front and rear ends of the upper part of the support;

[0018] The driving assembly comprises a motor and a driving shaft, wherein the motor is arranged on the bracket, one end of the driving shaft is rotatably connected to the motor, and the other end of the driving shaft is connected to one or two front and rear supporting wheels located on the same side of the bracket;

[0019] The screening sleeve comprises an inner sleeve, an outer sleeve and a rotating flange ring;

[0020] At least one of the outer cylinders is sleeved outside the inner cylinder in a sleeved manner, and there is a spacing between the outer cylinders and between the outer cylinder and the inner cylinder, and the outer cylinders are connected to each other and between the outer cylinder and the inner cylinder respectively through support rods;

[0021] The inner cylinder comprises at least two inner cylinder flange rings, the inner cylinder flange rings are connected by long rods, and a plurality of the long rods are arranged at intervals on the flange rings of the inner cylinder flange rings to form a cylindrical grid structure;

[0022] One of the outer cylinders includes at least two outer cylinder flange rings, and the outer sides of the outer cylinder flange rings are wrapped with a screen to form a cylindrical screen structure;

[0023] The apertures of the respective screens of the outer cylinders sleeved outside the inner cylinder gradually decrease from the inside to the outside, and the aperture of the screen of the innermost inner cylinder is smaller than the spacing width of the grilles of the inner cylinder;

[0024] At least two rotating flange rings are respectively arranged at two ends of the outermost outer cylinder of the screening sleeve;

[0025] The screening sleeve is placed on the supporting wheel through the rotating flange ring, the port of the screening sleeve located at the front end of the bracket is the screening sleeve and also the discharge port of the inner cylinder and each of the outer cylinders, and the port of the screening sleeve located at the rear end of the bracket is the screening sleeve and also the feed port of the inner cylinder and each of the outer cylinders;

[0026] The discharge assembly is arranged on one side of the discharge port, and the discharge assembly is composed of a stacked arrangement of discharge guides, the number of which is two more than the number of the outer cylinders, and the receiving end of each of the discharge guides is respectively arranged below the discharge port of the inner cylinder and below the discharge port of each of the outer cylinders, and the receiving end of the discharge guide located at the bottom of the discharge assembly extends to the bottom of the outer cylinder of the outermost layer of the screening sleeve.

[0027] As a preferred technical solution:

[0028] The bracket is a frame-type structure with a low front and a high rear, and the supporting wheels respectively arranged on both sides of the front and rear ends of the upper part of the bracket are also distributed with a low front and a high rear. The screening sleeve is placed on the supporting wheels with a low front and a high rear through its rotating flange ring.

[0029] As another preferred technical solution:

[0030] From the feed port to the discharge port, the diameter of each inner cylinder flange ring on the inner cylinder gradually decreases, and each inner cylinder flange ring with a gradually decreasing diameter is connected by a long rod, and a plurality of the long rods are arranged at intervals on the flange ring of each inner cylinder flange ring to form a trumpet-shaped cylindrical grid structure;

[0031] On the same outer cylinder, from the feed port of the screening sleeve to the discharge port of the screening sleeve, the diameter of each inner cylinder flange ring gradually decreases, and the outer cylinder flange rings with gradually decreasing diameters are connected by the screen wrapped on the outside to form a trumpet-shaped cylindrical screen structure.

[0032] Further:

[0033] The end of each outer cylinder located at the feed port of the screening sleeve is closed by an annular cover plate, and the inner ring of the annular cover plate is connected to the outer ring of the inner cylinder flange ring.

[0034] As a preferred technical solution:

[0035] The screening sleeve is also provided with a driving flange ring, and the driving assembly further comprises a driving wheel;

[0036] The driving flange ring is fixedly sleeved on the outermost outer cylinder of the screening sleeve and is located in the middle of the outer cylinder. The driving wheel is mounted on the driving shaft and is rollingly connected with the driving flange ring.

[0037] Furthermore, the driving flange ring is a gear ring with external teeth, and the driving wheel is a gear that can cooperate with the gear ring.

[0038] Furthermore, the material discharging device is a belt conveyor.

[0039] Furthermore, a universal wheel is provided at the bottom of the bracket, and a braking mechanism is provided on the universal wheel.

[0040] Furthermore, the motor is a servo motor.

[0041] Compared with the prior art, the beneficial effects and significant improvements of the present invention are:

[0042] 1) The present invention provides a sand and gravel screening device, which includes a bracket, a driving assembly, a screening sleeve and a discharging assembly, wherein the bracket is a frame-type structure and the two sides of the front and rear ends thereof are respectively provided with supporting wheels, the driving assembly includes a motor and a driving shaft arranged on the bracket, the two ends of the driving shaft are respectively connected to the motor and one or two front and rear supporting wheels located on the same side of the bracket, the screening sleeve includes an inner cylinder, a rotating flange ring and at least one outer cylinder, the outer cylinder is set outside the inner cylinder in a set manner, and there is a spacing between each outer cylinder and between the outer cylinder and the inner cylinder, and the inner cylinder is composed of an inner cylinder flange ring and a long rod The outer cylinder is a cylindrical screen structure composed of a screen wrapped by an outer cylinder flange ring. The apertures of the respective screens of the outer cylinders mounted outside the inner cylinder gradually decrease from the inside to the outside, and the aperture of the screen of the innermost inner cylinder is smaller than the spacing width of the inner cylinder grid. The screening sleeve is placed on the supporting wheel by rotating the flange ring. The discharging assembly is composed of a stacked arrangement of discharging and exporting devices. The driving shaft is driven by the rotation of the motor, and the driving shaft drives the supporting wheel, and the supporting wheel drives the screening sleeve to rotate, so that the sand and gravel raw materials loaded in the screening sleeve can be screened through the grid of the inner cylinder and the screen of the outer cylinder.

[0043] 2) The sand and gravel screening device provided by the present invention has a screening sleeve including an inner cylinder of a cylindrical grid structure and at least one outer cylinder of a cylindrical screen structure. The sand and gravel raw materials can be screened into sand and gravel of at least three particle size specifications in one operation, which is at least twice as effective as the conventional sand and gravel screening device, and improves the screening efficiency, thereby meeting various needs of construction;

[0044] 3) The sand and gravel screening device provided by the present invention has a unique conception, ingenious design, simple structure, and is easy to manufacture and use. The driving component and the screening sleeve are separately arranged, which solves the maintenance and repair problems of the easily damaged driving component of the sand and gravel screening device, and can extend the service life of the device and reduce the labor intensity of the operator. Therefore, it has great application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solution of the present invention, a brief introduction is given below to the drawings used in the embodiments of the present invention.

[0046] Obviously:

[0047] The drawings described below are only drawings of some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work, but these other drawings also belong to the drawings required for use in the embodiments of the present invention.

[0048] Figure 1 A schematic diagram of the three-dimensional structure of a sand and gravel screening device provided by an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of a top view of a sand and gravel screening device provided in an embodiment of the present invention;

[0050] Figure 3 A schematic diagram of the structure of a feeding port of a screening sleeve in a sand and gravel screening device provided in an embodiment of the present invention;

[0051] Figure 4 A schematic structural diagram of a discharge port of a screening sleeve in a sand and gravel screening device provided in an embodiment of the present invention.

[0052] In the figure:

[0053] 100- bracket, 110- supporting wheel;

[0054] 200-driving assembly, 210-motor, 220-driving shaft, 230-driving wheel;

[0055] 300-screening sleeve, 310-inner cylinder, 311-inner cylinder flange ring, 312-long rod, 320-outer cylinder, 321-outer cylinder flange ring, 322-screen, 330-rotating flange ring, 340-support rod, 350-annular cover plate, 360-driving flange ring;

[0056] 400-discharging assembly, 410-discharging guider. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution, beneficial effects and significant progress of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings provided in this specification. Obviously, all the described embodiments are only some embodiments of the present invention, rather than all embodiments;

[0058] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0059] It should be noted that:

[0060] The terms "first", "second", etc. in the specification and claims of the present invention and the drawings of the embodiments of the present invention are only used to distinguish different objects rather than to describe a specific order; in addition, the term "comprise" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0061] What needs to be understood is:

[0062] In the description of the embodiments of the present invention, some indicative orientation or position words used are only based on the orientation or position relationship shown in the drawings of the embodiments of the present invention. They are for the purpose of facilitating the description of the embodiments of the present invention and simplifying the explanation, rather than indicating or implying the specific orientation, specific orientation structure and operation that the device or element described must have. Therefore, they should not be understood as limitations on the present invention.

[0063] In the description of the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "connection" and "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or a movable connection, or it can be integrated; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0064] It should also be noted that:

[0065] The following specific embodiments may be combined with each other, and the same or similar concepts or processes therein may not be described in detail in some embodiments.

[0066] The technical solution of the present invention is described in detail below with specific embodiments.

[0067] Example

[0068] This embodiment provides a sand and gravel screening device for screening sand and gravel for construction.

[0069] like Figure 1 A schematic diagram of the three-dimensional structure of a sand and gravel screening device provided by an embodiment of the present invention, Figure 2 A schematic diagram of a top view of a sand and gravel screening device provided by an embodiment of the present invention, and Figure 3 A structural schematic diagram of a feeding port of a screening sleeve in a sand and gravel screening device provided by an embodiment of the present invention, Figure 4 The structural schematic diagram of the discharge port of the screening sleeve in a sand and gravel screening device provided by an embodiment of the present invention is shown as follows:

[0070] A sand and gravel screening device, comprising:

[0071] Support 100, driving assembly 200, screening sleeve 300 and discharging assembly 400;

[0072] The support 100 is a frame structure, and support wheels 110 are respectively provided on both sides of the front and rear ends of the upper part of the support 100;

[0073] The driving assembly 200 includes a motor 210 and a driving shaft 220. The motor 210 is disposed on the bracket 100. One end of the driving shaft 220 is rotatably connected to the motor 210. The other end of the driving shaft 220 is connected to one or two front and rear supporting wheels 110 located on the same side of the bracket 100.

[0074] The screening sleeve 300 includes an inner sleeve 310, an outer sleeve 320 and a rotating flange ring 330;

[0075] At least one outer cylinder 320 is mounted outside the inner cylinder 310 in a nested manner, and there is a spacing between the outer cylinders 320 and between the outer cylinder 320 and the inner cylinder 310. The outer cylinders 320 and between the outer cylinder 320 and the inner cylinder 310 are connected by support rods 340.

[0076] The inner cylinder 310 includes at least two inner cylinder flange rings 311, and the inner cylinder flange rings 311 are connected by long rods 312. Several long rods 312 are arranged at intervals on the flange rings of the inner cylinder flange rings 311 to form a cylindrical grid structure.

[0077] An outer cylinder 320 includes at least two outer cylinder flange rings 321, and the outer side of each outer cylinder flange ring 321 is wrapped with a screen 322 to form a cylindrical screen structure;

[0078] The apertures of the screens 322 of the outer cylinders 320 mounted outside the inner cylinder 310 gradually decrease from the inside to the outside, and the aperture of the screen 322 of the innermost inner cylinder 320 is smaller than the spacing width of the grilles of the inner cylinder 310;

[0079] At least two rotating flange rings 330 are respectively arranged at two ends of the outermost outer cylinder 320 of the screening sleeve 300;

[0080] The screening sleeve 300 is placed on the supporting wheel 110 by rotating the flange ring 330. The port of the screening sleeve 300 located at the front end of the bracket 100 is the screening sleeve 300 and also the discharge port of the inner cylinder 310 and each outer cylinder 320. The port of the screening sleeve 300 located at the rear end of the bracket 100 is the screening sleeve 300 and also the feed port of the inner cylinder 310.

[0081] The discharge assembly 400 is arranged on one side of the discharge port, and the discharge assembly 400 is composed of a stacked arrangement of discharge guides 410, the number of which is two more than the number of outer cylinders 320, and the material receiving end of each discharge guide 410 is respectively arranged below the discharge port of the inner cylinder 310 and below the discharge port of each outer cylinder 320, and the material receiving end of the discharge guide 410 located at the bottom of the discharge assembly 400 extends to the bottom of the outer cylinder 320 of the outermost layer of the screening sleeve 300.

[0082] From the above description, we can see that:

[0083] First, the sand and gravel screening device provided in this embodiment, through the ingenious combination of the bracket, the driving assembly, the screening sleeve and the discharging assembly, enables the sand and gravel raw materials fed into the screening sleeve to be screened into at least three kinds of sand and gravel of particle size specifications in one operation through the grille of the inner cylinder and the screen of the outer cylinder, which is at least twice as effective as the conventional sand and gravel screening device, thereby significantly improving the screening efficiency and meeting various needs of construction;

[0084] Secondly, in the sand and gravel screening device provided in this embodiment, the driving assembly and the screening sleeve are separately arranged, thereby solving the maintenance and repair problem of the vulnerable driving assembly of the sand and gravel screening device, and can extend the service life of the device and reduce the labor intensity of the operator;

[0085] At the same time, the sand and gravel screening device provided in this embodiment has a simple structure and is extremely convenient to manufacture, use, and transport. Therefore, it has great application and promotion value.

[0086] As a preferred embodiment, Figure 1 It can be seen that in this embodiment:

[0087] The bracket 100 is a frame-type structure with a low front and a high rear, and the support wheels 110 respectively arranged on both sides of the upper front and rear ends of the bracket 100 are also distributed with a low front and a high rear. The screening sleeve 300 is placed on the support wheel 110 with a low front and a high rear through its rotating flange ring 330.

[0088] By adopting the above-mentioned preferred embodiment, after the sand and gravel entering from the feed port of the screening sleeve are screened, sand and gravel of various specifications can be conveniently discharged from the discharge port through the high head difference, without causing the backlog of materials in the screening sleeve, thereby improving the screening efficiency.

[0089] In order to further improve the screening efficiency of sand and gravel, in this embodiment, the following preferred implementation manner can also be adopted, namely:

[0090] From the feed port to the discharge port, the diameter of each inner cylinder flange ring 311 on the inner cylinder 310 gradually decreases, and each inner cylinder flange ring 311 with a gradually decreasing diameter is connected by a long rod 312. Several long rods 312 are arranged at intervals on the flange ring of each inner cylinder flange ring 311 to form a trumpet-shaped cylindrical grid structure;

[0091] On the same outer cylinder 320, the diameter of each inner cylinder flange ring 321 gradually decreases from the feed port of the screening sleeve to the discharge port of the screening sleeve, and the outer cylinder flange rings 321 with gradually decreasing diameters are connected to form a trumpet-shaped cylindrical screen structure through the screen 322 wrapped on the outside thereof.

[0092] The screening sleeve formed by this embodiment has a larger feed port, so the sand and gravel can be fed more easily and faster.

[0093] After the sand and gravel are screened, the amount of each type of sand and gravel is less than the initial amount of sand and gravel entering the screening sleeve, and the number of discharge ports is more than the feed ports, so it will not cause discharge difficulties;

[0094] In this way, the screening efficiency can be improved.

[0095] Further, such as Figure 3 As shown:

[0096] The ends of the outer cylinders 320 located at the feed ports of the screening sleeves are closed by an annular cover plate 350 , and the inner ring of the annular cover plate 350 is connected to the outer ring of the inner cylinder flange ring 321 .

[0097] Through such improvements, it can be avoided that the original sand and gravel enter the outer cylinder by mistake when entering the screening sleeve, causing screening quality problems.

[0098] As another preferred embodiment, Figure 1 It can be seen that in this embodiment:

[0099] A driving flange ring 360 is also provided on the screening sleeve 300, and the driving assembly 200 further includes a driving wheel 230;

[0100] The driving flange ring 360 is fixedly mounted on the outermost outer cylinder 320 of the screening sleeve 300 and is located in the middle of the outer cylinder 320 . The driving wheel 230 is mounted on the driving shaft 220 and is rollingly connected to the driving flange ring 360 .

[0101] By adopting the above-mentioned preferred embodiment, the rotation of the screening sleeve can be made more stable, thereby improving the screening efficiency, ensuring the stable operation of the device, and improving the safety performance of the device.

[0102] Furthermore, in the above preferred embodiments:

[0103] The driving flange ring 360 may be a gear ring with external teeth, and the driving wheel 230 may be a gear that can cooperate with the gear ring.

[0104] Obviously, the transmission by the meshing method between the driving flange ring and the driving wheel can improve the utilization rate of the motor output power and improve the stability of the device operation.

[0105] Furthermore, in this embodiment, the material discharging device 410 may adopt a belt conveyor to more conveniently and quickly transport the screened sand and gravel to the construction site.

[0106] Furthermore, in this embodiment, a universal wheel (not shown in the figure) can be provided at the bottom of the bracket 100, and a braking mechanism (not shown in the figure) can be provided on the universal wheel (not shown in the figure) so as to conveniently and quickly arrange the sand and gravel screening device to the place where it is needed.

[0107] Furthermore, in this embodiment, the motor 210 may be a servo motor to better control the operation of the screening sleeve.

[0108] In summary, we can see that:

[0109] The sand and gravel screening device provided by the present invention has a unique conception, ingenious design, simple structure, and is convenient to manufacture, use and transport. It can achieve unexpected results and obtain good economic and social benefits. Therefore, it has great application and promotion value.

[0110] It should be noted that:

[0111] In the description of the above specification, the terms "this embodiment", "an embodiment of the present invention", "as shown in...", "further" and the like mean that the specific features, structures, materials or characteristics described in the embodiment or example are included in at least one embodiment or example of the present invention.

[0112] In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials or characteristics described may be combined or combined in a suitable manner in any one or more embodiments or examples.

[0113] In addition, under the premise that no contradiction occurs, a person of ordinary skill in the art may combine or combine different embodiments or examples and features of different embodiments or examples described in this specification.

[0114] Finally, it should be noted that:

[0115] The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them.

[0116] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. The non-essential improvements, adjustments or replacements made by those skilled in the art based on the contents of this specification are all within the scope of protection required by the present invention.

Claims

1. A sand and gravel screening device for screening sand and gravel for construction, characterized in that: include: Support, drive assembly, screening sleeve and discharge assembly; The support is a frame-type structure, and support wheels are respectively arranged on both sides of the front and rear ends of the upper part of the support; The driving assembly comprises a motor and a driving shaft, wherein the motor is arranged on the bracket, one end of the driving shaft is rotatably connected to the motor, and the other end of the driving shaft is connected to one or two front and rear supporting wheels located on the same side of the bracket; The screening sleeve comprises an inner sleeve, an outer sleeve and a rotating flange ring; At least one of the outer cylinders is sleeved outside the inner cylinder in a sleeved manner, and there is a spacing between the outer cylinders and between the outer cylinder and the inner cylinder, and the outer cylinders are connected to each other and between the outer cylinder and the inner cylinder respectively through support rods; The inner cylinder comprises at least two inner cylinder flange rings, the inner cylinder flange rings are connected by long rods, and a plurality of the long rods are arranged at intervals on the flange rings of the inner cylinder flange rings to form a cylindrical grid structure; One of the outer cylinders includes at least two outer cylinder flange rings, and the outer sides of the outer cylinder flange rings are wrapped with a screen to form a cylindrical screen structure; The apertures of the respective screens of the outer cylinders sleeved outside the inner cylinder gradually decrease from the inside to the outside, and the aperture of the screen of the innermost inner cylinder is smaller than the spacing width of the grilles of the inner cylinder; At least two rotating flange rings are respectively arranged at two ends of the outermost outer cylinder of the screening sleeve; The screening sleeve is placed on the supporting wheel through the rotating flange ring, the port of the screening sleeve located at the front end of the bracket is the screening sleeve and also the discharge port of the inner cylinder and each of the outer cylinders, and the port of the screening sleeve located at the rear end of the bracket is the screening sleeve and also the feed port of the inner cylinder and each of the outer cylinders; The discharge assembly is arranged on one side of the discharge port, and the discharge assembly is composed of a stacked arrangement of discharge guides, the number of which is two more than the number of the outer cylinders, and the receiving end of each of the discharge guides is respectively arranged below the discharge port of the inner cylinder and below the discharge port of each of the outer cylinders, and the receiving end of the discharge guide located at the bottom of the discharge assembly extends to the bottom of the outer cylinder of the outermost layer of the screening sleeve.

2. The sand and gravel screening device according to claim 1, characterized in that: The bracket is a frame-type structure with a low front and a high rear, and the supporting wheels respectively arranged on both sides of the front and rear ends of the upper part of the bracket are also distributed with a low front and a high rear. The screening sleeve is placed on the supporting wheels with a low front and a high rear through its rotating flange ring.

3. The sand and gravel screening device according to claim 1, characterized in that: From the feed port to the discharge port, the diameter of each inner cylinder flange ring on the inner cylinder gradually decreases, and each inner cylinder flange ring with a gradually decreasing diameter is connected by a long rod, and a plurality of the long rods are arranged at intervals on the flange ring of each inner cylinder flange ring to form a trumpet-shaped cylindrical grid structure; On the same outer cylinder, from the feed port of the screening sleeve to the discharge port of the screening sleeve, the diameter of each inner cylinder flange ring gradually decreases, and the outer cylinder flange rings with gradually decreasing diameters are connected by the screen wrapped on the outside to form a trumpet-shaped cylindrical screen structure.

4. The sand and gravel screening device according to claim 1, characterized in that: The end of each outer cylinder located at the feed port of the screening sleeve is closed by an annular cover plate, and the inner ring of the annular cover plate is connected to the outer ring of the inner cylinder flange ring.

5. The sand and gravel screening device according to claim 1, characterized in that: The screening sleeve is also provided with a driving flange ring, and the driving assembly further comprises a driving wheel; The driving flange ring is fixedly sleeved on the outermost outer cylinder of the screening sleeve and is located in the middle of the outer cylinder. The driving wheel is mounted on the driving shaft and is rollingly connected with the driving flange ring.

6. The sand and gravel screening device according to claim 5, characterized in that: The driving flange ring is a gear ring with external teeth, and the driving wheel is a gear that can cooperate with the gear ring.

7. The sand and gravel screening device according to claim 1, characterized in that: The material discharging and exporting device is a belt conveyor.

8. The sand and gravel screening device according to claim 1, characterized in that: The bottom of the bracket is also provided with a universal wheel, and the universal wheel is also provided with a braking mechanism.

9. The sand and gravel screening device according to claim 1, characterized in that: The motor is a servo motor.

Images