Automatic sand and stone screening equipment for road engineering

Abstract

The invention discloses automatic sand and stone screening equipment for road engineering, and relates to the technical field of sand and stone screening. Comprising a box body, a stop lever, a power mechanism and an angle adjusting mechanism, through a stop lever structure formed by mutual cooperation of a rotating shaft and a sleeve, the stop lever is matched with the rotating shaft to continuously rotate anticlockwise, broken stones clamped into screening gaps can be actively pushed out upwards in the screening process, and the problems of blocking, material blocking and the like of the broken stones due to the wedge-caulking effect are avoided; the phenomenon that a traditional screening structure is prone to clamping stagnation is eliminated, equipment runs smoothly, and the continuity of gravel screening is improved; through mutual cooperation of the power mechanism and the angle adjusting mechanism, adjustment and positioning of the screening gap between the rotating shaft and the sleeve can be achieved, preliminary separation of sand and gravel can be completed, and further grading treatment can be conducted on the sand; the diversified requirements of different scenes such as road construction, building construction and water conservancy projects on the sand grain size can be flexibly met, and the universality and practicability of the equipment are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of sand and gravel screening technology, and in particular to an automatic sand and gravel screening device for road engineering. Background Technology

[0002] Sand and gravel screening machines are key equipment used in road construction projects for the grading and processing of sand and gravel aggregates. They screen raw sand and gravel to obtain sand and crushed stone aggregates, providing matching materials for road construction. The aggregates processed by the screening machine have uniform gradation and stable quality, which can effectively improve the bearing capacity of the subgrade, the compaction of the pavement, and the strength and durability of concrete and asphalt mixtures. This ensures the overall structural stability of the road and the achievement of construction quality standards. At the same time, it improves the utilization rate of raw materials and construction efficiency, and reduces project costs. It is an important piece of equipment to ensure the quality and progress of road construction projects.

[0003] Existing sand and gravel screening machines have obvious defects in actual use: On the one hand, when the equipment is continuously screening, the gravel in the sand and gravel is easily stuck on the screen surface, causing the screen holes to be blocked, resulting in a decrease in screening efficiency, a decrease in aggregate grading accuracy, and difficulty in cleaning, which affects the continuity of construction; on the other hand, the screen aperture of traditional screening machines is mostly a fixed structure, which has poor versatility and limits the scope of application of the equipment.

[0004] To address these issues, we designed an automatic sand and gravel screening device for road engineering. Summary of the Invention

[0005] In order to overcome the defects of the prior art, the present invention provides an automatic sand and gravel screening device for road engineering. By rotating the rotating shaft counterclockwise, the crushed stone stuck in the screening area can be cleared and removed in time to avoid blockage. At the same time, the angle adjustment mechanism is used to adjust the inclination angle of the sleeve, expand or reduce the screening distance between the sleeve and the rotating shaft, so as to meet the screening requirements of aggregate particle size in various fields.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An automatic sand and gravel screening device for road engineering includes: a housing, a stop bar, a power mechanism, and an angle adjustment mechanism;

[0008] The box is equipped with a partition, which is spaced from the top of the box. The partition divides the box into two chambers. Multiple baffles are inclinedly arranged inside the box.

[0009] The stop bar specifically comprises a rotating shaft, a sleeve, a sprocket, an assembly shaft, and a connecting plate. A power mechanism drives the rotating shaft to rotate counterclockwise. The rotating shaft is nested inside the sleeve, which covers a portion of the rotating shaft. The surface of the sleeve facing the adjacent rotating shaft is sloped. One end of the rotating shaft extends upwards through the housing. A sprocket is installed on the extended end of the rotating shaft, and a connecting plate is installed on the extended end of the sleeve. A vertical groove is provided on the connecting plate. An assembly shaft is located at the downward-sloping end of the sleeve, below the rotating shaft. Correspondingly, an arc-shaped groove for the assembly shaft to nest is provided on the wall of the partition.

[0010] The angle adjustment mechanism is used to flip the sleeve and position the flipped sleeve.

[0011] In one embodiment, the top surface of the box is provided with a feed inlet, a ramp belt is provided on one side of the box, a first conveyor belt is provided at the lower end of one chamber of the box, and a second conveyor belt is provided at the lower end of the other chamber of the box. The first conveyor belt and the second conveyor belt have opposite conveying directions.

[0012] In one embodiment, a rubber strip is tightly fitted to the upper end face of the rotating shaft, and the rubber strip is fixedly connected to the sleeve on which the rotating shaft is fitted by bolts.

[0013] In one embodiment, the power mechanism is securely mounted on the housing via a first mounting plate. The power mechanism mainly consists of a servo motor, a first drive shaft, a second drive shaft, a first chain, a second chain, and bevel gears. The output end of the servo motor is directly connected to the first drive shaft, which synchronously drives multiple sprockets on the stop levers via the first chain. The second drive shaft is positioned on one side of the first chain, with both ends of the second chain wrapping around the first and second drive shafts respectively. A one-way bearing is installed at the connection between the second chain and the first drive shaft, and this one-way bearing is in an idle state when rotating counterclockwise. The second chain provides transmission power to the angle adjustment mechanism via two sets of bevel gears.

[0014] In one embodiment, when the servo motor rotates counterclockwise, it drives multiple rotating shafts to rotate synchronously via the first drive shaft and the first chain; when the servo motor rotates clockwise, it drives the angle adjustment mechanism via the second drive shaft and the second chain to complete the corresponding action.

[0015] In one embodiment, the angle adjustment mechanism includes: a connecting shaft, a reciprocating screw, a slider, an outer tube, and a limiting plate; the connecting shaft is rotatably connected to the outer wall of the housing, and the connecting shaft is arranged at a 90-degree angle with the plurality of stop rods; the end of the connecting shaft is connected to the reciprocating screw; a slider is mounted on the reciprocating screw, and the lower end of the slider is provided with abutting protrusions; the outer tube is nested on the connecting shaft, and the top surface of the outer tube is provided with a plurality of connecting rods, the upper ends of the plurality of connecting rods being nested into the vertical sliding grooves of the plurality of connecting plates; the bottom surface of the outer tube is provided with a plurality of positioning protrusions, and the slider is connected to the outer tube through a first spring rod; the limiting plate is connected to the housing through a second spring rod provided on its bottom surface, and its top surface is provided with a plurality of positioning grooves, the positioning protrusions engaging and embedding into the positioning grooves; the top end of the limiting plate is provided with a plurality of protrusions, and when the abutting protrusions move horizontally, they can press down on the protrusions, thereby driving the limiting plate to move downward.

[0016] In one embodiment, to allow the limiting plate to move downward smoothly, there are two reciprocating screws, which are respectively located at both ends of the connecting shaft. A sliding rod is provided on the slider of the left reciprocating screw, and the sliding rod is slidably connected to the housing. The length of the limiting plate is the same as the total length of the connecting shaft and the two reciprocating screws, and multiple protrusions are provided at both ends.

[0017] In one embodiment, the direction of movement for adjusting the gap between the rotating shaft and the adjacent baffle is as follows: when the slider moves to the left along the reciprocating screw, it pushes the outer tube to move to the left to reduce the gap between the rotating shaft and the adjacent baffle; when the slider moves to the right along the reciprocating screw, it pulls the outer tube to move to the right to increase the gap between the rotating shaft and the adjacent baffle.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) The present invention uses a baffle structure that works in conjunction with the rotating shaft and the sleeve. With the rotating shaft rotating counterclockwise continuously, it can actively push the crushed stone stuck in the screening gap upward during the screening process, avoiding problems such as the crushed stone getting stuck and blocking due to the wedge effect. It eliminates the defects of traditional screening structures that are easy to get stuck and difficult to clean, making the equipment run more smoothly and stably, and greatly improving the continuity and efficiency of sand and gravel screening.

[0020] (2) The present invention can adjust and position the screening gap between the rotating shaft and the sleeve by cooperating with the power mechanism and the angle adjustment mechanism. It can not only complete the initial separation of sand and gravel, but also further classify the sand. It can flexibly adapt to the diverse needs of sand particle size in different scenarios such as road construction, building construction, and water conservancy projects, and significantly improve the versatility and practicality of the equipment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the internal structure of the housing of the present invention;

[0023] Figure 3 This is a schematic diagram of the power mechanism structure of the present invention;

[0024] Figure 4 This is a schematic diagram of the stop bar structure of the present invention;

[0025] Figure 5 This is a schematic diagram of the cross-sectional structure of the stop bar of the present invention;

[0026] Figure 6 This is a schematic diagram of the rotating shaft driving the crushed stone to rotate according to the present invention;

[0027] Figure 7 This is a schematic diagram showing the connection between the partition plate and the assembly shaft of the present invention;

[0028] Figure 8 This is a schematic diagram of the angle adjustment mechanism of the present invention;

[0029] Figure 9 This is a schematic diagram of the motion of the angle adjustment mechanism of the present invention;

[0030] In the diagram: 1. Housing; 11. Feed inlet; 12. Partition; 13. First assembly plate; 14. Second assembly plate; 121. Arc-shaped slide groove; 2. Stop bar; 21. Rotating shaft; 22. Sleeve; 23. Sprocket; 24. Assembly shaft; 25. Rubber strip; 26. Connecting plate; 211. Rotating surface; 261. Vertical slide groove; 3. Power mechanism; 31. Servo motor; 32. First drive shaft; 33. Second drive shaft; 34. First chain 35. Second chain; 36. Bevel gear; 4. Angle adjustment mechanism; 41. Connecting shaft; 42. Reciprocating screw; 43. Slider; 44. Outer tube; 45. Limiting plate; 431. Abutting protrusion; 432. Slide rod; 433. First spring rod; 441. Connecting rod; 442. Positioning protrusion; 451. Positioning groove; 452. Protrusion; 453. Second spring rod; 5. Climbing belt; 6. First transmission belt; 7. Second transmission belt. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0032] The overall structure of the rotor blades is that multiple blades are evenly distributed radially at equal angles along the axis of the hub and are fixedly connected to the hub as an integrated structure.

[0033] Please see Figure 1 , 28. This invention discloses an automatic sand and gravel screening device for road engineering, comprising: a housing 1, a baffle 2, a power mechanism 3, and an angle adjustment mechanism 4;

[0034] Please see Figure 1-2 The box body 1 has a feed inlet 11 at one end of its top surface. Inside the box body 1, there is a partition 12 that is vertically fixed to the bottom surface of the box body 1. There is a certain gap between the upper end of the partition 12 and the top surface of the box body 1. The partition 12 divides the internal space of the box body 1 into chamber A and chamber B. The feed inlet 11 is connected to chamber A. A ramp belt 5 is provided on one side of the box body 1. The ramp belt 5 can lift the sand and gravel raw materials to a specified height. Then the sand and gravel enter the interior of chamber A through the feed inlet 11.

[0035] The sand and gravel entering chamber A are screened by multiple inclined baffles 2 inside, separating the mixed sand and gravel into coarse sand and gravel; the gravel slides down to chamber B along the inclined direction of the multiple baffles 2, while the coarse sand falls to the lower end of chamber A through the gap between two adjacent baffles 2.

[0036] A first conveyor belt 6 is provided at the lower end of chamber A, which is used to transport the falling coarse sand to the outside of chamber A; a second conveyor belt 7 is provided at the lower end of chamber B, which is used to transport the crushed stone to the outside of chamber B. The conveying directions of the first conveyor belt 6 and the second conveyor belt 7 for coarse sand and crushed stone are opposite.

[0037] Please see Figure 4-5 The baffle 2 is specifically composed of a rotating shaft 21, a sleeve 22, a sprocket 23, an assembly shaft 24, a rubber strip 25, and a connecting plate 26. The rotating shaft 21 has a smooth surface and is driven by the power mechanism 3 to rotate counterclockwise. The rotating shaft 21 is movably nested inside the sleeve 22, with the sleeve 22 only covering a portion of the rotating shaft 21, thus forming a screening gap between the rotating shaft 21 on a single baffle 2 and the sleeve 22 on another adjacent baffle 2. The side surface of the rotating shaft 21 facing the adjacent sleeve 22 is a rotating surface 211, while the side surface of the sleeve 22 facing the adjacent rotating shaft 21 is a slope. This slope can guide sand and gravel down the slope to the screening gap position, ensuring smooth screening operation.

[0038] A rubber strip 25 is tightly fitted to the upper end face of the rotating shaft 21. The rubber strip 25 is fixedly connected to the sleeve 22 on which the rotating shaft 21 is sleeved by bolts. The main function of the rubber strip 25 is to prevent gravel from getting stuck in the gap between the sleeve 22 and the rotating shaft 21, so as to prevent the rotating shaft 21 from being directly squeezed and rubbed by gravel during its rotation, thereby improving the service life of the stop bar 2.

[0039] The rotating shaft 21 and the sleeve 22 extend upwards from the outside of the housing 1. A sprocket 23 is installed on the extended end of the rotating shaft 21, and a connecting plate 26 is installed on the extended end of the sleeve 22.

[0040] A vertical groove 261 is provided on the upper part of the sleeve 22; an assembly shaft 24 is provided at the downward inclined end of the sleeve 22, which is located below the rotation shaft 21. Please refer to [link / reference]. Figure 7 The partition 12 has an arc-shaped groove 121 on its wall surface for mounting the shaft 24 to be nested.

[0041] During the sand and gravel screening process, when some crushed stone accidentally gets stuck in the screening gap between the rotating shaft 21 and the sleeve 22, the rotating shaft 21 can be rotated counterclockwise. With the rotational force of the rotating surface 211 of the rotating shaft 21, the stuck crushed stone can be pushed upward, thereby avoiding problems such as crushed stone getting stuck or blocking in the screening gap, and ensuring that the screening operation continues smoothly.

[0042] The purpose of the assembly shaft 24 being positioned below the rotating shaft 21 is to ensure that the overall installation height of the rotating shaft 21 is higher than the top surface height of the partition 12, thereby ensuring that the falling gravel can slide smoothly down the baffle 2 into the B chamber without being blocked by the partition 12, thus completing the diversion of materials.

[0043] The arc-shaped groove 121 on the partition plate 12 is designed to allow the sleeve 22 to rotate and adjust within a small range around the rotating shaft 21, thereby precisely adjusting the size of the screening gap formed by the rotating shaft 21 and the sleeve 22 between two adjacent baffles 2, so as to meet the screening requirements of sand and gravel of different particle sizes.

[0044] Please see Figure 6 The purpose of the sleeve 22 is that if the gap between adjacent rotating shafts 21 is used directly for sand and gravel screening, the surface movement directions of adjacent rotating shafts 21 at the gap position are opposite, which will cause some of the crushed stone falling into the gap to rotate. During the continuous rotation, the crushed stone is easily squeezed into the narrowest part of the gap between adjacent rotating shafts 21, thus forming a wedging effect, causing the crushed stone to become tighter and tighter as it rotates, eventually leading to jamming and blockage. At the same time, the rotating shafts 21, relying solely on their inclined arrangement, cannot overcome the large frictional force generated after jamming, making it difficult for the crushed stone to slide smoothly along the inclined direction, which will directly affect the continuous and stable operation of the entire screening device.

[0045] Please see Figure 3The power mechanism 3 is securely mounted on the housing 1 via the first mounting plate 13. The power mechanism 3 mainly consists of a servo motor 31, a first drive shaft 32, a second drive shaft 33, a first chain 34, a second chain 35, and a bevel gear 36. The output end of the servo motor 31 is directly connected to the first drive shaft 32. The first drive shaft 32 synchronously drives the sprockets 23 on multiple stop levers 2 via the first chain 34 to achieve transmission. The second drive shaft 33 is positioned on one side of the first chain 34, and the two ends of the second chain 35 are respectively wrapped around the first drive shaft 32 and the second drive shaft 33.

[0046] A one-way bearing (not shown in the figure) is installed at the connection between the second chain 35 and the first drive shaft 32. The one-way bearing is in an idle state when rotating counterclockwise. The second chain 35 provides transmission power to the angle adjustment mechanism 4 through two sets of bevel gears 36. The specific working method is as follows: when the servo motor 31 rotates counterclockwise, it drives multiple rotating shafts 21 to rotate synchronously through the first drive shaft 32 and the first chain 34; when the servo motor 31 rotates clockwise, it drives the angle adjustment mechanism 4 to complete the corresponding action through the second drive shaft 33 and the second chain 35.

[0047] The angle adjustment mechanism 4 positions the multiple sleeves 22 on one hand and adjusts the screening distance between the multiple rotating shafts 21 and the sleeves 22 on the other. In actual operation, it can not only efficiently complete the initial separation of crushed stone and sand, but also further refine the classification of the separated sand. The screening distance is flexible and adjustable, which can meet the screening standards of conventional sand specifications such as coarse sand and fine sand in road construction, and can also be widely adapted to the diverse needs of different engineering fields for sand particle size. Given that the requirements for sand particle size vary significantly in different industry scenarios such as building construction, water conservancy projects, foundation backfilling, brick making raw materials, and mortar preparation, and are not limited to a few fixed sand particle size standards, this device can adapt to a variety of complex and variable screening operation scenarios by adjusting the screening distance, thus broadening the applicability of the equipment and improving the overall versatility of the equipment.

[0048] Please see Figure 8The angle adjustment mechanism 4 includes: a connecting shaft 41, a reciprocating screw 42, a slider 43, an outer tube 44, and a limiting plate 45. The connecting shaft 41 is rotatably connected to the outer wall of the housing 1, and the connecting shaft 41 is arranged at a 90-degree angle with the multiple stop bars 2. The two ends of the connecting shaft 41 are respectively connected to the reciprocating screw 42, wherein the left reciprocating screw 42 is driven by the second transmission shaft 33 through the bevel gear 36. The two reciprocating screws 42 are respectively equipped with sliders 43. The slider 43 on the left reciprocating screw 42 is provided with a sliding rod 432. The sliding rod 432 is slidably connected to the housing 1. Its function is to limit the slider 43 circumferentially when the left reciprocating screw 42 rotates clockwise, so that the slider 43 can make a stable reciprocating linear motion in the horizontal direction. The lower ends of the two sliders 43 are respectively provided with abutting protrusions 431.

[0049] The outer tube 44 is nested on the connecting shaft 41. The top surface of the outer tube 44 is provided with multiple connecting rods 441. The upper ends of the multiple connecting rods 441 are respectively nested into the vertical sliding grooves 261 of the multiple connecting plates 26 to form a sliding fit. The bottom surface of the outer tube 44 is provided with multiple positioning protrusions 442. The slider 43 on the right reciprocating screw 42 is connected to the outer tube 44 through the first spring rod 433. By limiting the slider 43 through the first spring rod 433, the slider 43 is circumferentially limited when the right reciprocating screw 42 rotates clockwise, so that the slider 43 can make a stable reciprocating linear motion in the horizontal direction.

[0050] The limiting plate 45 is connected to the second assembly plate 14 extending from the housing 1 via a second spring rod 453 on its bottom surface. The length of the limiting plate 45 is the same as the total length of the connecting shaft 41 and the two reciprocating lead screws 42. Multiple positioning grooves 451 are provided on its top surface, and positioning protrusions 442 engage and embed into the positioning grooves 451. That is, the limiting plate 45, through the positioning protrusions 442, the outer tube 44, the connecting rod 441, and the connecting plate 26, jointly positions the sleeve 22. Multiple protrusions 452 are provided at both ends of the limiting plate 45. When the abutment protrusion 431 moves horizontally, it can press down on the protrusions 452, thereby driving the limiting plate 45 downwards.

[0051] Working principle of this invention:

[0052] Sand and gravel are conveyed by the inclined belt 5 and fed into chamber A through the feed inlet 11. The sand and gravel are screened by the gaps between the multiple baffles 2. The crushed stone slides down into chamber B along the inclined direction of the multiple baffles 2 and is conveyed to the outside of the box 1 by the second conveyor belt 7. The coarse sand falls to the lower end of chamber A through the gap between two adjacent baffles 2 and is conveyed to the outside of the box 1 by the first conveyor belt 6. During this process, the power mechanism 3 drives the rotating shaft 21 to rotate counterclockwise continuously. When some crushed stone is accidentally stuck in the screening gap between the rotating shaft 21 and the sleeve 22, the stuck crushed stone can be pushed upward by the rotational force of the rotating surface 211 on the rotating shaft 21.

[0053] Please see Figure 9 When adjusting the screening gap between the rotating shaft 21 and the sleeve 22, the servo motor 31 rotates clockwise, driving the reciprocating screws 42 on both sides to rotate synchronously through the second transmission shaft 33. The slider 43 then moves horizontally along the reciprocating screws 42. Since the lower end of the positioning protrusion 442 is engaged in the positioning groove 451 in the initial state, and the outer tube 44 is in a fixed state, when the slider 43 moves, it will first compress the first spring rod 433, and at the same time, it will abut against the protrusion 431 and press down the protrusion 452, causing the limiting plate 45 to move downward. The positioning groove 451 and the positioning protrusion 442 will separate from each other, releasing the fixed state of the outer tube 44, and thus releasing the limiting constraint on the multiple sleeves 22. Subsequently, the first spring rod 433 will reset, and the slider 43 will continue to drive the outer tube 44 to move synchronously. Through the connecting rod 441, it will push the connecting plate 26, causing the multiple sleeves 22 to rotate around the rotating shaft 21 as the axis, realizing the rotation shaft

[0054] The screening gap between sleeve 21 and sleeve 22 is reduced and adjusted. When the abutting protrusion 431 moves to the position between the two protrusions 452 and the positioning protrusion 442 is aligned with the other positioning groove 451, the limiting plate 45 is reset upward under the action of the second spring rod 453. The lower end of the positioning protrusion 442 engages with the corresponding positioning groove 451, completing the positioning and fixing of the outer tube 44 and multiple sleeves 22. Thus, the screening gap reduction and adjustment operation is completed. When it is necessary to expand the screening gap, the slider 43 moves to the end of the reciprocating screw 42 and then moves in the opposite direction to reset and repeat the above component actions. The only difference is that the first spring rod 433 is changed from compression to tension.

[0055] It should be noted that the purpose of using two reciprocating lead screws 42 to drive the two sliders 43 to move is to ensure that the abutting protrusions 431 at the lower ends of the two sliders 43 can simultaneously abut against the protrusions 452 at both ends of the limiting plate 45 during the movement of the two sliders 43, thereby ensuring that the limiting plate 45 is subjected to uniform force and moves smoothly when it moves downward, and avoiding the phenomenon of tilting or jamming of the limiting plate 45 due to force on one side.

Claims

1. An automatic sand and gravel screening device for road engineering, comprising: Box body (1), baffle (2), power mechanism (3), angle adjustment mechanism (4); characterized in that: a partition (12) is provided inside the box body (1), and there is a certain distance between the partition (12) and the top surface of the box body (1), and the partition (12) divides the inside of the box body (1) into two chambers; multiple baffles (2) are inclinedly arranged inside the box body (1). The stop bar (2) specifically consists of a rotating shaft (21), a sleeve (22), a sprocket (23), an assembly shaft (24), and a connecting plate (26); the power mechanism (3) drives the rotating shaft (21) to rotate counterclockwise. The rotating shaft (21) is nested inside the sleeve (22), wherein the sleeve (22) covers part of the area of ​​the rotating shaft (21), and the surface of the sleeve (22) facing the adjacent rotating shaft (21) is set as a slope; the upward-sloping end of the rotating shaft (21) extends through... Outside the housing (1), a sprocket (23) is installed on the extended end of the rotating shaft (21), and a connecting plate (26) is installed on the extended end of the sleeve (22). A vertical groove (261) is provided on the connecting plate (26). An assembly shaft (24) is provided at the downward inclined end of the sleeve (22). The assembly shaft (24) is located below the rotating shaft (21). An arc-shaped groove (121) is provided on the wall of the partition (12) for the assembly shaft (24) to be nested. The angle adjustment mechanism (4) is used to flip the sleeve (22) and position the flipped sleeve (22).

2. The automatic sand and gravel screening equipment for road engineering according to claim 1, characterized in that: The top surface of the box (1) is provided with a feed inlet (11), a ramp belt (5) is provided on one side of the box (1), a first transmission belt (6) is provided at the lower end of one chamber of the box (1), and a second transmission belt (7) is provided at the lower end of the other chamber of the box (1). The transmission directions of the first transmission belt (6) and the second transmission belt (7) are opposite.

3. The automatic sand and gravel screening equipment for road engineering according to claim 1, characterized in that: A rubber strip (25) is tightly fitted to the upper end face of the rotating shaft (21), and the rubber strip (25) is fixedly connected to the sleeve (22) on which the rotating shaft (21) is sleeved by bolts.

4. The automatic sand and gravel screening equipment for road engineering according to claim 1, characterized in that: The power mechanism (3) is securely mounted on the housing (1) via the first mounting plate (13). The power mechanism (3) is mainly composed of a servo motor (31), a first drive shaft (32), a second drive shaft (33), a first chain (34), a second chain (35), and a bevel gear (36). The output end of the servo motor (31) is directly connected to the first drive shaft (32). The first drive shaft (32) drives the sprockets (23) on multiple stops (2) synchronously via the first chain (34). The second drive shaft (33) is arranged on one side of the first chain (34). The two ends of the second chain (35) are respectively wrapped around the first drive shaft (32) and the second drive shaft (33). A one-way bearing is installed at the connection between the second chain (35) and the first drive shaft (32). The one-way bearing is in an idle state when rotating counterclockwise. The second chain (35) provides transmission power to the angle adjustment mechanism (4) via two sets of bevel gears (36).

5. The automatic sand and gravel screening equipment for road engineering according to claim 1, characterized in that: When the servo motor (31) rotates counterclockwise, it drives multiple rotating shafts (21) to rotate synchronously through the first drive shaft (32) and the first chain (34); when the servo motor (31) rotates clockwise, it drives the angle adjustment mechanism (4) through the second drive shaft (33) and the second chain (35) to complete the corresponding action.

6. The automatic sand and gravel screening equipment for road engineering according to claim 1, characterized in that: The angle adjustment mechanism (4) includes: a connecting shaft (41), a reciprocating screw (42), a slider (43), an outer tube (44), and a limiting plate (45); the connecting shaft (41) is rotatably connected to the outer wall of the housing (1), and the connecting shaft (41) is arranged at a 90-degree angle with the multiple stops (2), and the end of the connecting shaft (41) is connected to the reciprocating screw (42); the reciprocating screw (42) is equipped with a slider (43), and the lower end of the slider (43) is respectively provided with abutting protrusions (431); the outer tube (44) is nested on the connecting shaft (41), and the top surface of the outer tube (44) is provided with multiple connecting rods (441), and the multiple connecting rods (441) are connected to the outer tube (441). 1) The upper end of each of the connecting plates (26) is nested into the vertical grooves (261) of the connecting plates (26); the bottom surface of the outer tube (44) is provided with multiple positioning protrusions (442), and the slider (43) is connected to the outer tube (44) through the first spring rod (433); the limiting plate (45) is connected to the box (1) through the second spring rod (453) provided on its bottom surface, and multiple positioning grooves (451) are opened on its top surface. The positioning protrusions (442) are engaged and embedded in the positioning grooves (451). Multiple protrusions (452) are provided at the top end of the limiting plate (45). When the abutting protrusions (431) move horizontally, they can press down on the protrusions (452) and drive the limiting plate (45) to move downward.

7. The automatic sand and gravel screening equipment for road engineering according to claim 6, characterized in that: In order to allow the limiting plate (45) to move downward smoothly, there are two reciprocating screws (42). The two reciprocating screws (42) are respectively set at both ends of the connecting shaft (41). The slider (43) on the left reciprocating screw (42) is provided with a sliding rod (432), and the sliding rod (432) is slidably connected to the housing (1). The length of the limiting plate (45) is consistent with the total length of the connecting shaft (41) and the two reciprocating screws (42), and multiple protrusions (452) are provided at both ends.

8. The automatic sand and gravel screening equipment for road engineering according to claim 6, characterized in that: The direction of movement for adjusting the gap between the rotating shaft (21) and the adjacent baffle is as follows: when the slider (43) moves to the left along the reciprocating screw (42), it pushes the outer tube (44) to move to the left to reduce the gap between the rotating shaft (21) and the adjacent baffle; when the slider (43) moves to the right along the reciprocating screw (42), it pulls the outer tube (44) to move to the right to expand the gap between the rotating shaft (21) and the adjacent baffle.

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