Gravel grading device for constructional engineering

Abstract

The invention relates to the technical field of constructional engineering, and discloses a stone crushing and grading device for constructional engineering, the stone crushing and grading device comprises a stone crushing mechanism and a grading mechanism, a connecting pipeline and universal wheels are fixedly mounted at the top and the bottom of a grading box respectively, and three screening drawers are movably mounted in the grading box; a screening steel net is fixedly installed at the bottom of each screening drawer, a rotating rod is rotationally connected to the center of each screening steel net, a cross-shaped inserting rod is fixedly installed at the top of each rotating rod, and shifting rods are fixedly installed on the left side and the right side of each rotating rod. According to the gravel grading device for constructional engineering, screening steel meshes with the pore diameters gradually reduced from top to bottom are installed in the three screening drawers correspondingly; when stones enter the grading box through the connecting pipeline, the stones of different sizes are accurately separated into the corresponding screening drawers under the action of the screening steel net, stone grading is efficiently and accurately completed, the labor cost is remarkably reduced, and the project period is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of construction engineering, in particular to a crushed stone grading device for construction engineering. Background Art

[0002] In the construction process, stone is an indispensable basic material, and its size specifications are crucial to meeting the needs of different projects; however, in the face of diverse construction objects, the requirements for stone size also change accordingly, which requires the ability to flexibly adjust the size of the stone in actual operations.

[0003] The stone crushing device in the prior art usually processes stones by direct crushing, which has significant deficiencies in the discharge process, that is, all crushed stones are discharged uniformly without any classification measures. This design defect means that even after the initial crushing process, it is still necessary to rely on manual secondary screening in order to select the stone size that meets the construction standards. This not only increases labor costs, but also prolongs the project cycle. Therefore, we propose a stone crushing grading device for construction projects. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a crushed stone grading device for construction engineering, which has the advantage of being able to quickly grade and classify crushed stones, and solves the problem that the crushing devices in the prior art usually use a direct crushing method to process stones, and have significant deficiencies in the discharging link, that is, all crushed stones are discharged uniformly without any classification measures. This design defect means that even after the initial crushing process, it is still necessary to rely on manual secondary screening in order to select the stone size that meets the construction standards, which not only increases labor costs, but also prolongs the project cycle.

[0006] (II) Technical solution

[0007] In order to achieve the above-mentioned purpose of being able to quickly grade and classify the crushed stones, the present invention provides the following technical solutions: a crushed stone grading device for construction engineering, comprising a crushing mechanism and a grading mechanism, the grading mechanism comprising a grading box, a connecting pipe, a universal wheel, a screening drawer, a screening steel mesh, a rotating rod, a cross plug rod, a toggle rod, a rotating shaft, a gear set, a driving motor, a mounting plate, a limit plate, a limit socket, a limit fixing plate, a limit sleeve, a spring, a sliding plate, a top plate and a plug-in rod, the top and bottom of the grading box are respectively fixedly installed with a connecting pipe and a universal wheel, three screening drawers are movably installed inside the grading box, the bottom of each screening drawer is fixedly installed with a screening steel mesh, the center position of each screening steel mesh is rotatably connected with a rotating rod, and the top of the rotating rod A cross plug rod is fixedly installed on the part, a toggle rod is fixedly installed on the left and right sides of each of the rotating rods, the inner bottom wall of the grading box is rotatably connected with a rotating shaft, a gear set is installed on the outside of the rotating shaft, a driving motor is fixedly installed on the inner bottom wall of the grading box, a mounting plate is fixedly installed on the left and right sides of each of the screening drawers, a limit plate is fixedly installed on the inner left wall and the inner right wall of the grading box, a limit socket is fixedly installed on the top of each limit plate, the inner left wall and the inner right wall of the grading box are fixedly installed with a limit fixing plate, a limit sleeve is fixedly installed on the bottom of the limit fixing plate, a spring is installed inside the limit sleeve, a sliding plate is slidably connected inside the limit sleeve, a top plate is fixedly installed on the bottom of the sliding plate, and a plug-in rod is fixedly installed on the bottom of the top plate.

[0008] Preferably, the stone crushing mechanism includes an equipment frame, a stone crushing box, a feeding port, a feeding pipe, a stone crushing roller, a driving box, a connecting gear, a driving gear and a servo motor, the stone crushing box is fixedly installed inside the equipment frame, the feeding port and the feeding pipe are respectively installed on the top and the bottom of the stone crushing box, two stone crushing rollers are rotatably connected inside the stone crushing box, the right side of the equipment frame is fixedly installed with a driving box, the driving box is rotatably connected inside with two connecting gears which are respectively fixedly connected to the right sides of two stone crushing rollers, a driving gear is meshed between the two connecting gears, and a servo motor is fixedly installed on the right side of the driving box.

[0009] Preferably, the connecting pipe is connected to the feed port via a threaded rod, the apertures of the three screening steel meshes decrease from top to bottom, and the bottoms of the six toggle rods are respectively fitted with the top outer surfaces of the three screening steel meshes.

[0010] Preferably, a cross plug rod is fixedly mounted on the top of each rotating rod, and a cross plug groove matched with the cross plug rod is opened at the bottom of each rotating rod, and the cross plug groove at the bottom of one of the rotating rods is plugged into the top of the rotating shaft.

[0011] Preferably, the gear set includes a first gear and a second gear, the first gear is fixedly mounted on the outside of the rotating shaft, the second gear is fixedly mounted on the output end of the driving motor, and the first gear and the second gear are meshed with each other.

[0012] Preferably, the inner left wall and the inner right wall of the grading box are respectively provided with three mounting plates, limit plates, limit sockets, limit fixing plates, limit sleeves, springs, sliding plates, top plates and plug rods.

[0013] Preferably, the mounting plates on the left and right sides of each screening drawer fit with the bottom of the top plate, the bottom of the plug rod passes through the mounting plate and is plugged into the limit socket, and a box door is movably installed on the front of the grading box.

[0014] Preferably, the two stone crushing rollers are meshed with each other, and the output end of the servo motor is fixedly connected to the driving gear.

[0015] (III) Beneficial effects

[0016] Compared with the prior art, the present invention provides a crushed stone grading device for construction engineering, which has the following beneficial effects:

[0017] 1. The crushed stone grading device for construction projects realizes efficient and automatic classification of crushed stones by setting up a grading mechanism. Specifically, three screening drawers are respectively installed with screening steel meshes with apertures gradually decreasing from top to bottom. When stones enter the grading box through the connecting pipe, stones of different sizes are accurately separated into corresponding screening drawers under the action of the screening steel meshes. The driving motor is connected to the rotating rod and the cross rod at the bottom through a gear set, driving the toggle rod to assist the screening steel mesh in three-level screening, ensuring efficient and accurate stone grading. This design avoids the tedious process of manual secondary screening, significantly reduces labor costs and shortens project cycles.

[0018] 2. The stone crushing and grading device used in this construction project has a seamless connection between the stone crushing mechanism and the grading mechanism, which greatly improves the overall processing efficiency; large stones are broken into smaller particles by the stone crushing roller driven by the servo motor, and are directly fed into the grading box through the discharge pipe; inside the grading box, the rotating shaft drives the toggle lever on the rotating rod to rotate, constantly toggling the stones on the screening steel net to promote the rapid screening of the stones; in addition, the limit system composed of the limit plate, limit socket, sliding plate and top plate ensures that the screening drawer can be quickly disassembled for easy cleaning and maintenance; this design not only improves the reliability and stability of the equipment, but also reduces the maintenance frequency and operation difficulty, thereby significantly improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the plane structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention;

[0021] Figure 3 It is a schematic diagram of the grading mechanism of the present invention;

[0022] Figure 4 For the present invention Figure 2 A is an enlarged schematic diagram;

[0023] Figure 5 It is a three-dimensional schematic diagram of the screening drawer and the screening steel mesh of the present invention;

[0024] Figure 6 It is a three-dimensional schematic diagram of the rotating rod, the cross-insertion rod and the toggle rod of the present invention;

[0025] Figure 7 It is a cross-sectional schematic diagram of the stone crushing mechanism of the present invention;

[0026] Figure 8 It is a top view schematic diagram of the stone crushing mechanism of the present invention.

[0027] In the figure: 1. crushing mechanism; 101. equipment frame; 102. crushing box; 103. feeding port; 104. feeding pipe; 105. crushing roller; 106. driving box; 107. connecting gear; 108. driving gear; 109. servo motor; 2. grading mechanism; 201. grading box; 202. connecting pipe; 203. universal wheel; 204. screening drawer; 205. screening steel net; 206. rotating rod; 207. cross plug rod; 208. toggle rod; 209. rotating shaft; 210. gear set; 211. driving motor; 212. mounting plate; 213. limit plate; 214. limit socket; 215. limit fixing plate; 216. limit sleeve; 217. spring; 218. sliding plate; 219. top plate; 220. plug rod. DETAILED DESCRIPTION

[0028] 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.

[0029] See also Figure 1-8A crushed stone grading device for construction engineering, comprising a crushing mechanism 1 and a grading mechanism 2, wherein the grading mechanism 2 comprises a grading box 201, a connecting pipe 202, a universal wheel 203, a screening drawer 204, a screening steel mesh 205, a rotating rod 206, a cross plug rod 207, a toggle rod 208, a rotating shaft 209, a gear set 210, a driving motor 211, a mounting plate 212, a limiting plate 213, a limiting socket 214, a limiting fixing plate 215, and a limiting sleeve 216 , spring 217, sliding plate 218, top plate 219 and plug-in rod 220, the top and bottom of the grading box 201 are respectively fixedly installed with connecting pipe 202 and universal wheel 203, and the grading box 201 is internally movably installed with three screening drawers 204, and the bottom of each screening drawer 204 is fixedly installed with a screening steel mesh 205, and the center position of each screening steel mesh 205 is rotatably connected with a rotating rod 206, and the top of the rotating rod 206 is fixedly installed with A cross rod 207, a toggle rod 208 is fixedly installed on the left and right sides of each rotating rod 206, the inner bottom wall of the grading box 201 is rotatably connected with a rotating shaft 209, and a gear set 210 is installed on the outside of the rotating shaft 209. A driving motor 211 is fixedly installed on the inner bottom wall of the grading box 201, and a mounting plate 212 is fixedly installed on the left and right sides of each screening drawer 204. A limit plate 213 is fixedly installed on the inner left wall and the inner right wall of the grading box 201. Each limit plate A limit socket 214 is fixedly installed on the top of 213, a limit fixing plate 215 is fixedly installed on the inner left wall and the inner right wall of the grading box 201, a limit sleeve 216 is fixedly installed on the bottom of the limit fixing plate 215, a spring 217 is installed inside the limit sleeve 216, a sliding plate 218 is slidably connected inside the limit sleeve 216, a top plate 219 is fixedly installed on the bottom of the sliding plate 218, and a plug rod 220 is fixedly installed on the bottom of the top plate 219.

[0030] Embodiment 1:

[0031] Stone crushing process: When in use, the large stones to be crushed and graded are placed in the crushing box 102 through the feeding port 103, and the servo motor 109 is started. The output end of the servo motor drives the driving gear 108 to rotate at a high speed. Since the two connecting gears 107 in the driving box 106 are respectively fixedly connected to the right sides of the two crushing rollers 105, and they are meshed with the driving gear 108, the rotation of the driving gear 108 will drive the two connecting gears 107 to rotate in the opposite direction, and then drive the two meshing crushing rollers 105 to rotate synchronously in the opposite direction. During the rotation of the crushing rollers 105, the stones are subjected to strong squeezing and friction between them. For example, when crushing granite at a construction site, the hardness of the granite is relatively high, but under the strong squeezing pressure of the crushing roller 105, the internal structure is gradually destroyed, and the large blocks are gradually broken into smaller particles. The crushed stones are discharged from the crushing box 102 through the discharge pipe 104.

[0032] Power transmission stability: This gear transmission method can ensure stable power transmission and precise synchronization of the rotation speed and direction of the two crushing rollers 105. Even when dealing with stones of different hardness and size, a stable crushing effect can be maintained. Taking the crushing of sandstone as an example, although the hardness of sandstone is lower than that of granite, the gear transmission system can still make the crushing roller 105 work stably without jamming or inconsistent rotation speed, thereby ensuring crushing efficiency and quality.

[0033] Embodiment 2:

[0034] Screening process: The crushed stone discharged from the discharge pipe 104 enters the grading box 201 through the connecting pipe 202. The connecting pipe 202 is connected to the feed port 103 by a threaded rod. This connection method is easy to disassemble and install. When the equipment is transported or the connecting parts need to be replaced, the operation is simple and convenient. Three screening drawers 204 are arranged in the grading box 201. The aperture of the screening steel mesh 205 at the bottom of each screening drawer 204 decreases from top to bottom. When the crushed stone enters the grading box 201, it first falls on the screening steel mesh 205 of the topmost screening drawer 204.

[0035] Auxiliary screening mechanism: start the drive motor 211, and the second gear at its output end drives the first gear meshing with it to rotate. The first gear is fixed on the rotating shaft 209, so that the rotating shaft 209 rotates, and the top of the rotating shaft 209 is plugged into the cross plug groove at the bottom of one of the rotating rods 206. The cross plug rod 207 on the top of the rotating rod 206 ensures that the rotating rod 206 can rotate synchronously with the rotating shaft 209, and the toggle rods 208 on the left and right sides of the rotating rod 206 also rotate accordingly, constantly toggling the gravel on the screening steel mesh 205. For example, when processing a batch of gravel with a wide range of particle sizes, the toggle action of the toggle rod 208 can redistribute the gravel that may have been accumulated or blocked near the sieve holes, speeding up the screening speed, and ensuring that the gravel smaller than the sieve holes can smoothly pass through the sieve holes and fall into the next layer, while the larger ones remain in the current layer, thereby achieving precise screening.

[0036] Grading effect: After being screened by the three-layer screening steel mesh 205, crushed stones of different sizes are accurately separated into corresponding screening drawers 204. For example, when building a road, crushed stones of different particle sizes are required for the base layer, middle layer and surface layer. The grading device can efficiently grade the mined mixed crushed stones into different screening drawers 204 according to the particle size standards required by the project to meet the construction needs.

[0037] Embodiment three:

[0038] Disassembly process: When it is necessary to clean the screening drawer 204 or maintain the equipment, since the inner left wall and the inner right wall of the grading box 201 are respectively provided with relevant components, the mounting plates 212 on the left and right sides of each screening drawer 204 are fitted with the bottom of the top plate 219, and the plug-in rod 220 passes through the mounting plate 212 and is inserted into the limit socket 214. At this time, the top plate 219 is lifted upward, and the top plate 219 drives the sliding plate 218 to slide upward in the limit sleeve 216, compressing the spring 217. At the same time, the plug-in rod 220 is pulled out from the limit socket 214, and the screening drawer 204 can be pulled out from the grading box 201. For example, after the screening drawer 204 has been used for a long time, the sieve holes may be blocked by fine particles, affecting the screening effect. Through this convenient disassembly method, the screening drawer 204 can be easily taken out for cleaning.

[0039] Maintenance and installation: For the clogged screening steel mesh 205, you can use a special brush or high-pressure water gun to clean it to remove the attached particles. If the screening steel mesh 205 is damaged, it needs to be replaced in time. After the maintenance is completed, reinsert the screening drawer 204 into the grading box 201, loosen the top plate 219, and under the elastic force of the spring 217, the top plate 219 drives the plug-in rod 220 to move downward and reinsert the limit socket 214 to complete the installation. During multiple disassembly and installation processes, the design of this limit and plug-in structure can ensure that the screening drawer 204 is accurately installed each time without affecting the normal operation of the equipment.

[0040] Embodiment 4:

[0041] Equipment mobility: The universal wheels 203 at the bottom of the grading box 201 make the entire device easy to move. At the construction site, the equipment position can be flexibly adjusted according to actual needs. For example, in small construction projects, the site space is limited, and the equipment can be moved to a position close to the material storage area or the construction operation surface to reduce the distance of gravel transportation and improve construction efficiency. For example, when building a small house, the equipment can be placed directly near the foundation of the house, and the crushed and graded gravel can be immediately used for foundation construction, saving a lot of manpower and time costs.

[0042] Application in large projects: In large-scale construction projects, such as building commercial complexes or bridge projects, the construction area is large and the demand for gravel in different construction stages is different. The equipment can be flexibly moved between different construction areas according to the construction progress and site layout. For example, in bridge construction, the equipment can be placed near the bridge piers during the foundation construction phase to provide gravel of suitable particle size for the pouring of the bridge piers; and during the bridge deck paving phase, the equipment can be moved to the bridge deck construction area to meet the demand for gravel for bridge deck paving.

[0043] Adaptability to different construction environments: Whether in construction sites with complex terrain such as mountainous areas or in sites with limited space in cities, the universal wheels 203 can play a role. In mountainous areas, the equipment can be slowly moved on relatively rugged ground through the universal wheels 203 to reach a suitable working position; in cities, it can be easily moved in narrow streets or construction sites, adapting to different construction environments and improving the practicality and versatility of the equipment.

[0044] In summary, the crushed stone grading device for construction projects realizes efficient and automatic classification of crushed stones by setting up a grading mechanism 2; specifically, three screening drawers 204 are respectively installed with screening steel meshes 205 with apertures gradually decreasing from top to bottom; when the stones enter the grading box 201 through the connecting pipe 202, stones of different sizes are accurately separated into corresponding screening drawers 204 under the action of the screening steel meshes 205; the driving motor 211 is connected to the rotating rod 206 and the cross plug rod 207 at the bottom thereof through the gear set 210, driving the toggle rod 208 to assist the screening steel mesh 205 in performing three-stage screening, thereby ensuring efficient and accurate completion of stone grading; this design avoids the tedious process of manual secondary screening, significantly reduces labor costs and shortens project cycles.

[0045] Moreover, in the stone crushing and grading device for construction engineering, the stone crushing mechanism 1 and the grading mechanism 2 are seamlessly connected, which greatly improves the overall processing efficiency; the large stones are crushed into smaller particles by the stone crushing roller 105 driven by the servo motor 109, and are directly sent to the grading box 201 through the feeding pipe 104; inside the grading box 201, the rotating shaft 209 drives the toggle rod 208 on the rotating rod 206 to rotate, constantly toggle the stones on the screening steel mesh 205, and promote the rapid screening of the stones; in addition, the limiting system composed of the limiting plate 213, the limiting socket 214, the sliding plate 218 and the top plate 219 ensures the screening drawer 204 can be disassembled quickly for easy cleaning and maintenance; this design not only improves the reliability and stability of the equipment, but also reduces the maintenance frequency and operating difficulty, thereby significantly improving work efficiency and solving the problem that the stone crushing device in the prior art usually adopts a direct crushing method to process stones, and there are significant deficiencies in the discharge link, that is, all crushed stones are discharged uniformly without classification measures. This design defect means that even after the initial crushing process, it still needs to rely on manual secondary screening in order to select the stone size that meets the construction standards, which not only increases labor costs, but also prolongs the project cycle.

[0046] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0047] 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 crushed stone grading device for construction engineering, comprising a crushing mechanism (1) and a grading mechanism (2), characterized in that: The grading mechanism (2) comprises a grading box (201), a connecting pipe (202), a universal wheel (203), a screening drawer (204), a screening steel mesh (205), a rotating rod (206), a cross plug rod (207), a toggle rod (208), a rotating shaft (209), a gear set (210), a driving motor (211), a mounting plate (212), a limiting plate (213), a limiting socket (214), a limiting fixing plate (215), a limiting sleeve (216), a spring (217), a sliding plate (218), and a top plate (219). ) and a plug-in rod (220), the top and bottom of the grading box (201) are respectively fixedly installed with a connecting pipe (202) and a universal wheel (203), the interior of the grading box (201) is movably installed with three screening drawers (204), the bottom of each screening drawer (204) is fixedly installed with a screening steel mesh (205), the center position of each screening steel mesh (205) is rotatably connected with a rotating rod (206), the top of the rotating rod (206) is fixedly installed with a cross plug rod (207), each rotating rod ( The left and right sides of the grading box (206) are fixedly mounted with a toggle rod (208); the inner bottom wall of the grading box (201) is rotatably connected with a rotating shaft (209); a gear set (210) is installed outside the rotating shaft (209); a driving motor (211) is fixedly mounted on the inner bottom wall of the grading box (201); a mounting plate (212) is fixedly mounted on the left and right sides of each of the screening drawers (204); a limiting plate (213) is fixedly mounted on the inner left wall and the inner right wall of the grading box (201); and the top of each limiting plate (213) is fixedly mounted with a rotating shaft (209); and a rotating shaft (209) is installed outside the rotating shaft (209); and a driving motor (211) is fixedly mounted on the inner bottom wall of the grading box (201); and a mounting plate (212) is fixedly mounted on the left and right sides of each of the screening drawers (204); and a limiting plate (213) is fixedly mounted on the inner left wall and the inner right wall of the grading box (201). A limit socket (214) is fixedly installed on each of the inner left wall and the inner right wall of the grading box (201), a limit fixing plate (215) is fixedly installed on each of the inner left wall and the inner right wall, a limit sleeve (216) is fixedly installed on the bottom of the limit fixing plate (215), a spring (217) is installed inside the limit sleeve (216), a sliding plate (218) is slidably connected inside the limit sleeve (216), a top plate (219) is fixedly installed on the bottom of the sliding plate (218), and a plug rod (220) is fixedly installed on the bottom of the top plate (219).

2. A crushed stone classification device for construction engineering according to claim 1, characterized in that: The stone crushing mechanism (1) comprises an equipment frame (101), a stone crushing box (102), a material inlet (103), a material discharge pipe (104), a stone crushing roller (105), a driving box (106), a connecting gear (107), a driving gear (108) and a servo motor (109). The stone crushing box (102) is fixedly installed inside the equipment frame (101). The top and bottom of the stone crushing box (102) are respectively installed with a material inlet (103) and a material discharge pipe (104). Two stone crushing rollers (105) are rotatably connected inside the box (102), a driving box (106) is fixedly installed on the right side of the equipment frame (101), two connecting gears (107) are rotatably connected inside the driving box (106) and are respectively fixedly connected to the right sides of the two stone crushing rollers (105), a driving gear (108) is meshed between the two connecting gears (107), and a servo motor (109) is fixedly installed on the right side of the driving box (106).

3. A crushed stone classification device for construction engineering according to claim 2, characterized in that: The connecting pipe (202) is connected to the feed port (103) via a threaded rod, the apertures of the three screening steel meshes (205) decrease from top to bottom, and the bottoms of the six toggle rods (208) are respectively fitted with the top outer surfaces of the three screening steel meshes (205).

4. The crushed stone classification device for construction engineering according to claim 1, characterized in that: A cross plug rod (207) is fixedly mounted on the top of each rotating rod (206), and a cross plug groove matching the cross plug rod (207) is provided on the bottom of each rotating rod (206), wherein the cross plug groove at the bottom of one of the rotating rods (206) is plugged into the top of the rotating shaft (209).

5. The crushed stone classification device for construction engineering according to claim 1, characterized in that: The gear set (210) comprises a first gear and a second gear, wherein the first gear is fixedly mounted on the outside of the rotating shaft (209), and the second gear is fixedly mounted on the output end of the driving motor (211), and the first gear and the second gear are meshed with each other.

6. The crushed stone classification device for construction engineering according to claim 1, characterized in that: The inner left wall and the inner right wall of the grading box (201) are respectively provided with three mounting plates (212), a limiting plate (213), a limiting socket (214), a limiting fixing plate (215), a limiting sleeve (216), a spring (217), a sliding plate (218), a top plate (219) and a plug-in rod (220).

7. The crushed stone classification device for construction engineering according to claim 1, characterized in that: The mounting plates (212) on the left and right sides of each screening drawer (204) are fitted with the bottom of the top plate (219), the bottom of the plug-in rod (220) passes through the mounting plate (212) and is plugged into the limit socket (214), and a box door is movably installed on the front of the grading box (201).

8. The crushed stone classification device for construction engineering according to claim 2, characterized in that: The two stone crushing rollers (105) are meshed with each other, and the output end of the servo motor (109) is fixedly connected to the driving gear (108).

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