A screening device for concrete

Abstract

The invention discloses a screening device for concrete, comprising a box body, a feeding hopper, a screening mechanism, a feeding mechanism, a vibrating mechanism and an auxiliary mechanism. The screening mechanism consists of a spline shaft rod and a spline shaft sleeve rod, with a first screening plate and a second screening plate fixedly connected at both ends to achieve multi-stage screening and improve screening accuracy. The feeding mechanism achieves uniform speed feeding of sand and gravel through the cooperation of a sealing plate and an elliptical block to avoid sand and gravel accumulation on the first screening plate. The vibrating mechanism achieves lifting and reciprocating vibration of the screening plate through the interaction between a first protrusion on a fixed ring and a second protrusion on the first screening plate to effectively separate small particles of sand and gravel attached to the surface of large sand and gravel. The auxiliary mechanism comprises a rotating rod and a connecting rod, as well as an arc-shaped scraper to enhance the ability to screen large sand and gravel multiple times. The invention improves screening efficiency, reduces operating costs, reduces dust, and improves working environment.

Description

Technical Field

[0001] The invention relates to the technical field of concrete screening, in particular to a screening device for concrete. Background Art

[0002] Concrete is an engineering composite material widely used in the construction industry, usually composed of cement, sand, stone and water. In the production process of concrete, the screening of raw materials is a crucial step to ensure the quality and performance of concrete. The purpose of screening is to separate raw materials such as sand and gravel of different particle sizes for subsequent mixing and use. Traditional screening devices mostly use vibration screening. Although it can complete basic screening tasks, when processing a large amount of sand and gravel, the screen holes are easily blocked, resulting in low screening efficiency and affecting the production efficiency of concrete.

[0003] The existing Chinese patent with publication number CN117000579B includes an equipment frame; a feed frame; a middle screen drum, rotatably arranged on the equipment frame; a discharge drum, which is fixed on the equipment frame; a spiral lifting rod, arranged in the feed frame and the middle screen drum; a first threaded blade, fixedly connected between the spiral lifting rod and the inner side wall of the middle screen drum; a fine screen drum, rotatably connected to the equipment frame; a first receiving hopper, used to receive materials screened by the fine screen drum; a second receiving hopper, used to receive materials after being screened by the fine screen drum; a second threaded blade, fixedly connected between the inner side wall of the fine screen drum and the outer side wall of the middle screen drum.

[0004] When the above device is in use, the design mode of combining the drum screening structure and the spiral lifting structure realizes the combination of screening and lifting operations. However, in actual use, the sand and gravel are lifted in the drum for screening by rotating the spiral lifting rod. Since a large number of small particles of sand and gravel are attached to the surface of large pieces of sand and gravel, the screening of the sand and gravel is not thorough, which affects the screening effect of the concrete. Therefore, it is difficult to separate and screen the small particles of sand and gravel adhered to the surface of large pieces of sand and gravel.

[0005] For this purpose, we propose a screening device for concrete. Summary of the invention

[0006] The purpose of the present invention is to provide a screening device for concrete, which has the advantage of separating and screening small-grained sand and gravel materials on the surface of large sand and gravel, and solves the problems in the background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a screening device for concrete, comprising a box body fixedly supported by an external bracket and placed on the ground, wherein symmetrical positions on both sides of the end of the box body are penetrated and fixedly connected with a feeding hopper for feeding sand and gravel into the box body, and a screening mechanism for performing multi-stage screening of sand and gravel with different particle sizes is provided on the box body; The screening mechanism includes a spline shaft rod which is penetrated at the end of the box body and is connected to the box body by a fixed axis rotation and driven by a power mechanism to rotate. A spline shaft sleeve rod is sleeved on the outer contour of the spline shaft rod for lifting and reciprocating movement. The outer contours at symmetrical positions at both ends of the spline shaft sleeve rod are fixedly connected with a first screening plate and a second screening plate for multi-stage screening of sand and gravel with different particle sizes. The box body is provided with a feeding mechanism for uniformly feeding the sand and gravel in the feeding hopper into the box body and a vibration mechanism for separating and screening small particles of sand and gravel on the surface of large sand and gravel. Preferably, the feeding mechanism includes sealing plates coaxially rotatably connected at symmetrical positions on the top of the box body near the two side boxes to seal the discharge port at the bottom end of the feeding hopper, and each sealing plate is fixedly connected to a torsion spring on the opposite surface to the top of the box body to guide the sealing plate to reset and rotate.

[0008] Preferably, an elliptical block for quantitatively feeding sand and gravel into the hopper is fixedly connected to the outer contour of the spline shaft rod and the sealing plate, and a first guide hopper for guiding sand and gravel to the center of the first screening plate is fixedly connected to the inner wall of the top of the box body.

[0009] Preferably, the vibration mechanism includes a fixing ring fixedly connected to the inner wall of the box body near the bottom end of the first screen plate, a plurality of first protrusions fixedly connected to the fixing ring for pushing the first screen plate and the second screen plate to lift and reciprocate and vibrate, a plurality of second protrusions movably connected to the first protrusions are fixedly connected at positions corresponding to the first protrusions on the bottom of the first screen plate, and the first protrusions and the second protrusions are evenly placed on the fixing ring and the first screen plate respectively, and a second guide hopper is fixedly connected to the bottom of the fixing ring for guiding sand and gravel after initial screening by the first screen plate to the center position of the second screen plate for secondary screening.

[0010] Preferably, a fixing block is fixedly connected to the outer contour of the spline shaft rod near the bottom, and a reset spring for guiding the spline shaft sleeve rod to perform reset movement is fixedly connected to the opposite surface of the fixing block and the spline shaft sleeve rod.

[0011] Preferably, the first material guide hopper is provided with an auxiliary mechanism for multiple screening of large pieces of sand and gravel on the first screening plate, the auxiliary mechanism includes rotating rods and connecting rods coaxially connected to symmetrical positions on both sides of the first material guide hopper for reciprocating rotation toward or away from each other, and a tension spring is fixedly connected to the opposite side of the rotating rod and the connecting rod on each side for guiding the rotating rod and the connecting rod to perform reset rotation.

[0012] Preferably, the two rotating rods and the connecting rod are rotatably connected to connecting seats on the opposite surfaces away from one end of the rotating shaft, and the bottom of the two connecting seats on each side is fixedly connected to an arc-shaped scraper for moving large pieces of sand and gravel on the edge of the first screen plate to the center position for multiple screening.

[0013] Preferably, the outer contours of the box body at positions corresponding to the first screen plate and the second screen plate are penetrated and fixedly connected with the first discharge pipe and the second discharge pipe for centralized discharge of sand and gravel of different particle sizes, and the bottom end of the box body is fixedly connected with a discharge hopper for centralized discharge of small particles of sand and gravel, and the bottom end of the spline shaft rod is coaxially fixedly connected with a fan blade for lifting small particles of sand and gravel inside the box body and guiding them to the discharge hopper for discharge.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Through the cooperation of the spline shaft rod and the spline shaft sleeve rod, the precise control and efficient screening of the first screening plate and the second screening plate are realized, the screening accuracy is improved, the effective screening of sand and gravel with different particle sizes is ensured, and the precise requirements of concrete production for the particle size distribution of raw materials are met.

[0015] 2. Through the synergistic effect of the sealing plate and the elliptical block, the sand and gravel in the hopper are evenly and continuously delivered, avoiding the problems of screening plates and accumulation caused by concentrated delivery of sand and gravel, ensuring the continuity and uniformity of the screening process. At the same time, the quantitative delivery mechanism reduces material waste, improves the processing capacity and production efficiency of the screening device, and reduces maintenance costs and operational complexity.

[0016] 3. Through the interaction between the first protrusion on the fixed ring and the second protrusion on the first screening plate, the lifting and reciprocating vibration of the screening plate is realized, which effectively separates the small particles of sand and gravel attached to the surface of large pieces of sand and gravel, and improves the screening efficiency. Especially when processing wet sand or sticky materials, it can reduce the blockage and adhesion of materials and keep the screening process smooth.

[0017] 4. Through the combination of rotating rod, connecting rod and arc scraper, the multiple screening capacity of large sand and gravel on the first screening plate is enhanced. The arc scraper can move the large sand and gravel on the edge to the center, so that the large sand and gravel can be screened more fully, reducing material waste, and improving the uniformity of the screening product, ensuring the consistency and reliability of the screening effect.

[0018] The coordinated use of the above-mentioned structure solves the problem that in the actual use of the existing device, the sand and gravel are lifted in the drum for screening by rotating the spiral lifting rod. Since a large number of small particles of sand and gravel are attached to the surface of large pieces of sand and gravel, the screening of the sand and gravel is not thorough, which affects the screening effect of the concrete. Therefore, it is difficult to separate and screen the small particles of sand and gravel adhered to the surface of large pieces of sand and gravel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a cross-sectional schematic diagram of the three-dimensional structure of the present invention; Figure 3 This is a schematic diagram of the three-dimensional structure of the part where the elliptical block of the present invention is located; Figure 4 This is a schematic diagram of the three-dimensional structure of the arc scraper of the present invention; Figure 5 For the present invention Figure 3 Schematic diagram of the structure at A in the middle; Figure 6 For the present invention Figure 4 The schematic diagram after the festival is at B in the middle; Figure 7 It is a schematic cross-sectional view of the three-dimensional structure of the part where the first screening plate of the present invention is located; Figure 8 For the present invention Figure 7 Schematic diagram of the structure at C in the middle; Fig. 9 It is a schematic diagram of the three-dimensional structure of the part where the fixing ring of the present invention is located.

[0020] In the figure: 1. box body; 2. feeding hopper; 3. spline shaft rod; 4. spline shaft sleeve rod; 5. first screening plate; 6. second screening plate; 7. sealing plate; 8. torsion spring; 9. elliptical block; 10. fixing ring; 11. first protrusion; 12. second protrusion; 13. first guide hopper; 14. second guide hopper; 15. rotating rod; 16. connecting rod; 17. connecting seat; 18. arc scraper; 19. tension spring; 20. first discharge pipe; 21. second discharge pipe; 22. discharge hopper; 23. fan blade; 24. fixing block; 25. reset spring. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Embodiment 1:

[0022] See also Figures 1 to 9 The present invention provides a technical solution: a screening device for concrete, comprising a box body 1 fixedly supported by an external bracket and placed on the ground, wherein symmetrical positions on both sides of the end of the box body 1 are penetrated and fixedly connected with a feeding hopper 2 for feeding sand and gravel into the box body 1, and a screening mechanism for multi-stage screening of sand and gravel with different particle sizes is provided on the box body 1; The screening mechanism includes a spline shaft rod 3 which is penetrated at the end of a box body 1 and is rotatably connected to a fixed axis and driven to rotate by a power mechanism. A spline shaft sleeve rod 4 which is lifted and reciprocated is sleeved on the outer contour of the spline shaft rod 3. The first screening plate 5 and the second screening plate 6 which are used for multi-stage screening of gravel with different particle sizes are fixedly connected to the outer contours at symmetrical positions at both ends of the spline shaft sleeve rod 4. The box body 1 is provided with a feeding mechanism which feeds the gravel in the feeding hopper 2 into the box body 1 at a uniform speed and a vibration mechanism which separates and screens small particles of gravel on the surface of large gravel.

[0023] When in use, by setting up the box body 1, the box body 1 is supported and placed on the ground by an external bracket to improve the stability of the screening device. Through the feeding hopper 2 set on the box body 1, the sand and gravel to be screened are first placed inside the feeding hopper 2, and the feeding hopper 2 is connected with the inside of the box body 1, so that the feeding hopper 2 can feed the sand and gravel to be screened into the inside of the box body 1, and through the spline shaft rod 3 set on the box body 1, and the spline shaft rod 3 is driven to rotate by a motor, the motor can drive the spline shaft rod 3 to rotate on a fixed axis on the box body 1, and the spline shaft sleeve rod 4 is set on the spline shaft rod 3, and the first screening plate 5 and the second screening plate 6 are set on the spline shaft sleeve rod 4, so that the first screening plate The dividing plate 5 and the second screening plate 6 are attached to and movably connected with the inner wall of the box body 1, and at the same time, the spline shaft sleeve rod 4 can drive the first screening plate 5 and the second screening plate 6 to rotate synchronously along with the spline shaft rod 3, and the feeding hopper 2 puts the internal sand and gravel onto the surface of the first screening plate 5, so that the first screening plate 5 rotates and spreads the surface sand and gravel to the outside for screening under the action of centrifugal force, and the sand and gravel screened by the first screening plate 5 falls on the surface of the second screening plate 6, and at the same time, the second screening plate 6 can perform secondary screening on the sand and gravel screened by the first screening plate 5, and the aperture of the first screening plate 5 is larger than that of the second screening plate 6, so that multi-stage screening of sand and gravel with different particle sizes is realized. Through the feeding mechanism arranged on the box body 1, the feeding mechanism can uniformly feed the sand and gravel to be screened in the feeding hopper 2 onto the first screening plate 5 for screening operation, so as to avoid excessive accumulation of sand and gravel on the first screening plate 5, which affects the screening effect of sand and gravel. Through the vibration mechanism, the spline shaft sleeve rod 4 is connected to the spline shaft rod 3 for lifting and moving, so that the spline shaft sleeve rod 4 can drive the first screening plate 5 and the second screening plate 6 to be connected to the inner wall of the box body 1 for lifting and moving, so that the vibration mechanism can drive the first screening plate 5 and the second screening plate 6 to vibrate and screen the sand and gravel on the surface, and can vibrate and separate the small particles of sand and gravel attached to the surface of large pieces of sand and gravel. Embodiment 2:

[0024] On the basis of the first embodiment, further: The feeding mechanism includes sealing plates 7 coaxially rotatably connected at symmetrical positions on the top of the box body 1 near the two side boxes 1 for sealing the discharge port at the bottom of the feeding hopper 2, and each sealing plate 7 is fixedly connected to the opposite surface of the top of the box body 1 with a torsion spring 8 for guiding the sealing plate 7 to reset and rotate.

[0025] An elliptical block 9 for quantitatively feeding sand and gravel into the hopper 2 is fixedly connected to the outer contour of the spline shaft 3 at the corresponding position of the sealing plate 7, and a first guide hopper 13 for guiding sand and gravel to the center position of the first screening plate 5 is fixedly connected to the inner wall at the top of the box body 1.

[0026] When in use, through the sealing plate 7 provided on the box body 1, the sealing plate 7 can contact with the outlet end at the bottom of the feeding hopper 2 for sealing, and the torsion spring 8 provided on the sealing plate 7 enables the torsion spring 8 to support the position of the sealing plate 7, and through the elliptical block 9 provided on the spline shaft 3, the elliptical block 9 is coaxially fixedly connected with the spline shaft 3, so that the spline shaft 3 can drive the elliptical block 9 to rotate synchronously with the fixed axis, and when the two ends of the elliptical block 9 contact with the sealing plates 7 on both sides and rotate, the sealing plate 7 is moved away from the feeding hopper 2 under the action of the elliptical block 9. One side rotates, at this time, the torsion spring 8 rotates and contracts under the action of the sealing plate 7, and the first guide hopper 13 arranged on the box body 1, when the sealing plate 7 rotates and breaks away from the bottom end of the feeding hopper 2, can make the sand and gravel to be screened in the feeding hopper 2 fall toward the inside of the box body 1 under the action of gravity. At the same time, the first guide hopper 13 can guide the sand and gravel falling from the feeding hopper 2 to the center position of the first screening plate 5 for screening, and the sand and gravel can be diffused from the center position under the action of the centrifugal force of the rotation of the first screening plate 5, thereby further improving the screening effect of the sand and gravel.

[0027] When the elliptical block 9 rotates and loses contact with the sealing plate 7, the torsion spring 8 can drive the sealing plate 7 to reset and rotate in the direction close to the feeding hopper 2 under the action of its own torque, so that the sealing plate 7 can seal the discharge port at the bottom of the feeding hopper 2. As the elliptical block 9 continuously rotates on a fixed axis, the quantitative delivery of sand and gravel to be screened inside the feeding hopper 2 is achieved. Embodiment three:

[0028] On the basis of the second embodiment, further: The vibration mechanism includes a fixing ring 10 fixedly connected to the inner wall of the box body 1 near the bottom end of the first screening plate 5, and a plurality of first protrusions 11 are fixedly connected to the fixing ring 10 for pushing the first screening plate 5 and the second screening plate 6 to lift and reciprocate and vibrate, and a plurality of second protrusions 12 movably connected to the first protrusions 11 are fixedly connected to the positions corresponding to the first protrusions 11 at the bottom of the first screening plate 5, and the first protrusions 11 and the second protrusions 12 are evenly placed on the fixing ring 10 and the first screening plate 5 respectively, and a second guide hopper 14 is fixedly connected to the bottom of the fixing ring 10 to guide the sand and gravel after the initial screening of the first screening plate 5 to the center position of the second screening plate 6 for secondary screening.

[0029] A fixing block 24 is fixedly connected to the outer contour of the spline shaft rod 3 near the bottom, and a reset spring 25 is fixedly connected to the opposite surface of the fixing block 24 and the spline shaft sleeve rod 4 to guide the spline shaft sleeve rod 4 to reset.

[0030] When in use, through the fixing ring 10 provided on the box body 1 and the first protrusion 11 provided on the fixing ring 10, the fixing ring 10 can fix and support the first protrusion 11 on the inner wall of the box body 1, and through the second protrusion 12 provided on the first screening plate 5, the second protrusion 12 is fixedly supported on the first screening plate 5, so that the second protrusion 12 is in a corresponding position with the first protrusion 11, and along with the fixed-axis rotation of the first screening plate 5, the first screening plate 5 can drive the second protrusion 12 to rotate synchronously along the first protrusion 11, and through the fixing block 24 provided on the spline shaft rod 3, the fixing block 24 is fixedly supported on the spline shaft rod 3, and the return spring 25 is fixedly connected with the return spring 25 on the opposite surface of the spline shaft sleeve rod 4, so that the return spring 25 can support the spline shaft sleeve rod 4, and the second guide hopper 14 provided on the fixing ring 10 enables the second guide hopper 14 to screen the sand and gravel screened by the first screening plate 5 to the center position of the second screening plate 6.

[0031] When the first screen plate 5 drives the second protrusion 12 to contact and rotate with the box body 1, the second protrusion 12 can drive the first screen plate 5 to move in the upward vertical direction under the action of the first protrusion 11, and the spline sleeve rod 4 and the second screen plate 6 can move synchronously in the upward direction along with the first screen plate 5, so that the reset spring 25 is in a stretched state under the action of the spline sleeve rod 4. When the first screen plate 5 drives the second protrusion 12 to rotate and disengage from the first protrusion 11, the spline sleeve rod 4 can quickly pull the first screen plate 5 and the second screen plate 6 in the downward direction for reset movement under the tension of the reset spring 25, accompanied by the multiple first protrusions 11 and second protrusions 12 set on the first screen plate 5 and the fixing ring 10, so that the spline sleeve rod 4 can drive the first screen plate 5 and the second screen plate 6 to perform lifting and reciprocating vibration, and then the vibration of the first screen plate 5 can separate and screen the small particles of sand and gravel adhered to the surface of large pieces of sand and gravel, thereby further improving the screening effect of sand and gravel. Embodiment 4:

[0032] On the basis of the third embodiment, further: The first guide hopper 13 is provided with an auxiliary mechanism for multiple screening of large pieces of sand and gravel on the first screening plate 5, and the auxiliary mechanism includes a rotating rod 15 and a connecting rod 16 that are coaxially connected at symmetrical positions on both sides of the first guide hopper 13 and reciprocate toward or away from each other, and a tension spring 19 is fixedly connected on the opposite side of the rotating rod 15 and the connecting rod 16 on each side to guide the rotating rod 15 and the connecting rod 16 to perform reset rotation.

[0033] A connecting seat 17 is rotatably connected to the opposite surfaces of the two rotating rods 15 and the connecting rod 16 away from one end of the rotating shaft, and an arc-shaped scraper 18 is fixedly connected to the bottom of the two connecting seats 17 on each side for moving large pieces of sand and gravel on the edge of the first screening plate 5 to the center position for multiple screening.

[0034] When in use, the rotating rod 15 and the connecting rod 16 are provided on the first guide hopper 13, so that the rotating rod 15 and the connecting rod 16 are coaxially connected and rotatably connected on the first guide hopper 13, and the connecting seat 17 provided on the rotating rod 15 and the connecting rod 16 makes the connecting seat 17 rotatably connected on the rotating rod 15 and the connecting rod 16 on a fixed axis. Through the arc scraper 18 provided on the connecting seat 17 and the tension spring 19 provided on the rotating rod 15 and the connecting rod 16, the rotating rod 15 and the connecting rod 16 can pull the arc scraper 18 to fit the surface of the first screen plate 5 under the tension of the tension spring 19. When the first screen plate 5 moves in an upward vertical direction, the rotating rod 15 and the connecting rod 16 move in opposite directions under the action of the first screen plate 5. The arc scraper 18 is rotated in the opposite direction, and the rotating rod 15 and the connecting rod 16 push the arc scrapers 18 on both sides to move in opposite directions, and the arc scraper 18 is close to the edge of the first screen plate 5, so that the large pieces of sand and gravel close to the edge of the first screen plate 5 move to the arc surface opposite to the arc scraper 18. When the first screen plate 5 is reset in the downward direction, the rotating rod 15 and the connecting rod 16 can pull the arc scrapers 18 on both sides to move quickly toward the center position under the tension of the tension spring 19, and the arc scraper 18 can push the large pieces of sand and gravel on the arc surface to the center of the first screen plate 5, so that the large pieces of sand and gravel can be vibrated and screened multiple times, ensuring the separation effect of small particles of sand and gravel on the surface of large pieces of sand and gravel. Embodiment five:

[0035] On the basis of the fourth embodiment, further: The outer contours of the box body 1 corresponding to the first screening plate 5 and the second screening plate 6 are penetrated and fixedly connected with a first discharge pipe 20 and a second discharge pipe 21 for centralized discharge of sand and gravel of different particle sizes, and the bottom end of the box body 1 is fixedly connected with a discharge hopper 22 for centralized discharge of small-particle sand and gravel, and the bottom end of the spline shaft 3 is coaxially fixedly connected with a fan blade 23 for lifting small-particle sand and gravel inside the box body 1 and guiding it to the discharge hopper 22 for discharge.

[0036] When in use, the first discharge pipe 20 and the second discharge pipe 21 are arranged on the box body 1, and the first discharge pipe 20 and the second discharge pipe 21 are both fitted with the arc surface of the box body 1, so that the first discharge pipe 20 and the second discharge pipe 21 are connected with the inner wall of the box body 1, and the first screen plate 5 and the second screen plate 6 rotate, and the separated sand and gravel are moved toward the edge position under the action of centrifugal force, so that the first discharge pipe 20 and the second discharge pipe 21 can separate and discharge sand and gravel with different particle sizes at the edge positions of the first screen plate 5 and the second screen plate 6, and the discharge hopper 22 arranged on the box body 1 can The lower hopper 22 discharges the small particles of sand and gravel screened by the second screening plate 6 in a centralized manner, and the small particles of sand and gravel will be raised to generate dust during the vibration screening process. The fan blades 23 are arranged on the spline shaft 3, and the spline shaft 3 can drive the fan blades 23 to rotate synchronously, so that the fan blades 23 can guide the small particles of sand and gravel raised from the first screening plate 5 and the second screening plate 6 to the feeding hopper 2 for discharge, thereby further improving the screening effect and avoiding the mixing of the raised small particles of sand and gravel with the sand and gravel of different particle sizes discharged from the first discharge pipe 20 and the second discharge pipe 21, which affects the sand and gravel screening effect.

[0037] Furthermore, the existing device can separate and screen small particles of sand and gravel adhering to the surface of large pieces of sand and gravel during actual use, which is easy to use and better than traditional products.

[0038] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural components recorded in the specification and the drawings can also be directly processed according to the existing technical common sense. At the same time, the connection method of each component adopts the mature conventional means in the prior art, and the machinery, parts and equipment all adopt the conventional models in the prior art, so no specific description will be given here.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A screening device for concrete, characterized in that: It comprises a box body fixedly supported by an external bracket and placed on the ground, and symmetrical positions on both sides of the end of the box body are penetrated and fixedly connected with a feeding hopper for feeding sand and gravel into the box body, and a screening mechanism for multi-stage screening of sand and gravel with different particle sizes is provided on the box body; The screening mechanism includes a spline shaft rod which is penetrated at the end of the box and is connected to a fixed axis and driven by a power mechanism for rotation. A spline shaft sleeve rod is sleeved on the outer contour of the spline shaft rod for lifting and reciprocating movement. The first screening plate and the second screening plate for multi-stage screening of sand and gravel with different particle sizes are fixedly connected to the outer contours at symmetrical positions at both ends of the spline shaft sleeve rod. The box is provided with a feeding mechanism for uniformly feeding the sand and gravel in the feeding hopper into the inside of the box and a vibration mechanism for separating and screening small particles of sand and gravel on the surface of large pieces of sand and gravel.

2. A screening device for concrete according to claim 1, characterized in that: The feeding mechanism includes sealing plates coaxially connected to the symmetrical positions of the top of the box body near the two side boxes for sealing the discharge port at the bottom of the feeding hopper, and each sealing plate is fixedly connected to a torsion spring on the opposite surface of the sealing plate and the top of the box body to guide the sealing plate to reset and rotate.

3. A screening device for concrete according to claim 2, characterized in that: An elliptical block for quantitatively feeding sand and gravel into the hopper is fixedly connected to the outer contour of the spline shaft rod and the sealing plate, and a first guide hopper for guiding sand and gravel to the center of the first screening plate is fixedly connected to the inner wall of the top of the box body.

4. A screening device for concrete according to claim 3, characterized in that: The vibration mechanism includes a fixing ring fixedly connected to the inner wall of the box body near the bottom end of the first screen plate, a plurality of first protrusions fixedly connected to the fixing ring for pushing the first screen plate and the second screen plate to perform lifting and reciprocating vibration, a plurality of second protrusions movably connected to the first protrusions are fixedly connected to the positions corresponding to the first protrusions on the bottom of the first screen plate, and the first protrusions and the second protrusions are evenly placed on the fixing ring and the first screen plate respectively, and a second guide hopper is fixedly connected to the bottom of the fixing ring for guiding sand and gravel after initial screening by the first screen plate to the center position of the second screen plate for secondary screening.

5. A screening device for concrete according to claim 4, characterized in that: A fixing block is fixedly connected to the outer contour of the spline shaft rod near the bottom, and a reset spring for guiding the spline shaft sleeve rod to perform reset movement is fixedly connected to the opposite surface of the fixing block and the spline shaft sleeve rod.

6. A screening device for concrete according to claim 5, characterized in that: The first material guide hopper is provided with an auxiliary mechanism for screening large pieces of sand and gravel on the first screening plate multiple times, and the auxiliary mechanism includes rotating rods and connecting rods coaxially connected to perform reciprocating rotation toward or away from each other at symmetrical positions on both sides of the first material guide hopper, and a tension spring is fixedly connected to the opposite side of the rotating rod and the connecting rod on each side to guide the rotating rod and the connecting rod to perform reset rotation.

7. A screening device for concrete according to claim 6, characterized in that: The two rotating rods and the connecting rod are connected to connecting seats on the opposite surfaces away from the rotating shaft, and the bottom of the two connecting seats on each side is fixedly connected to an arc scraper for moving large pieces of sand and gravel on the edge of the first screening plate to the center position for multiple screening.

8. A screening device for concrete according to claim 7, characterized in that: The outer contours of the box body corresponding to the first screening plate and the second screening plate are penetrated and fixedly connected with the first discharge pipe and the second discharge pipe for centralized discharge of sand and gravel of different particle sizes, and the bottom end of the box body is fixedly connected with a discharge hopper for centralized discharge of small-particle sand and gravel, and the bottom end of the spline shaft rod is coaxially fixedly connected with a fan blade for lifting small-particle sand and gravel inside the box body and guiding it to the discharge hopper for discharge.

Images