CN114535086A

CN114535086A - A automatic feeding screening sand machine for civil engineering

Info

Publication number: CN114535086A
Application number: CN202111363289.XA
Authority: CN
Inventors: 周长顺; 李明永; 杨丽君
Original assignee: Shaoxing University Yuanpei College
Current assignee: Shaoxing University Yuanpei College
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2022-05-27

Abstract

The invention discloses an automatic feeding sand screening machine for civil engineering, aiming at solving the defect that the automatic feeding can not be realized in the prior art, and the invention adopts the following technical scheme: the method comprises the following steps: the sand screening machine body is used for screening sand in a vibration mode, and a sand inlet is formed in the sand screening machine body; the lifting box is used for conveying sand into the sand screening machine body, a feed inlet is formed in the lower end of the lifting box, a spiral lifting assembly is arranged in the lifting box and comprises a spiral rod arranged in the lifting box, and the upper end of the spiral rod is connected with a lifting motor. Through the effect of promotion subassembly, make the promotion subassembly can be with smooth transportation to the sand inlet of carrying the screening sand organism of sand for the sand can be sifted in the screening sand organism, great reduction workman's work burden, consequently, can not produce the dust, prevent the injury of dust to workman's health.

Description

A automatic feeding screening sand machine for civil engineering

Technical Field

The invention relates to the field of constructional engineering, in particular to an automatic feeding sand screening machine for civil engineering.

Background

In a building site, when the sand is used, the sand with different diameters needs to be selected according to actual conditions, for example, when the sand is used for injection molding of a flat top, the sand with a larger diameter is needed, and when the sand is used for decoration and tile sticking of a building facade, the sand with a smaller diameter is needed. In the existing sand screening machines, a lot of sand is screened when passing through a filter screen through the gravity of the sand, so that when the sand accumulated on the filter screen is too thick, screening and filtering are difficult to be carried out on a sand layer, and in order to avoid that the sand with smaller diameter on the upper layer can pass through the filter screen, the sand with smaller diameter can be screened out only by turning or secondary screening; in addition, the prior art also has the function that sand cannot be classified according to the diameter of the sand, namely the classification function is monotonous.

China patent publication No. CN2018102860443, bulletin No. 10, 23 and 2020, the name of the invention is that the application discloses a small-sized high-efficiency sand screening machine for civil engineering, which is a sand screening box, wherein a sand screening net cylinder is arranged on the inner side of the sand screening box, a sand screening shaft is arranged on the inner side of the sand screening net cylinder, a first motor connected with the sand screening shaft is further arranged on the left side of the sand screening box, the right end of the sand screening shaft is connected with an air inlet pipe through a rotary joint, the other end of the air inlet pipe is connected with an air blower, a first helical blade is arranged on the sand screening shaft on the left side of the inner part of the sand screening net cylinder, a plurality of porous stirring blades are circumferentially arranged on the sand screening shaft on the right side of the inner part of the sand screening net cylinder, stirring rods are arranged on the sand screening shaft on two sides of the porous stirring blades, and a plurality of exhaust heads are circumferentially arranged on the sand screening shaft on the right end of the inner part of the sand screening net cylinder. Although the efficiency of screening sand is improved, the feeding port is arranged at the top end of the sand screening machine, so that the sand screened by the sand screening machine needs to be conveyed to the top end of the sand screening machine through manpower or other machines for feeding when the sand screening machine is used, the labor force is increased or the machines are increased, and the sand screening machine capable of feeding the sand by self feeding is urgently needed; and the sand can be classified into two types according to the diameter of the meshes of the sand screening net cylinder during screening by the machine, wherein one type is the sand with the diameter larger than that of the meshes of the sand screening net cylinder, and the other type is the sand with the diameter smaller than that of the meshes of the sand screening net cylinder, and the sand classification function is monotonous.

Disclosure of Invention

The invention overcomes the defects in the prior art that: (1) the deficiency that automatic feeding cannot be realized; (2) the sand screening machine has the advantages that the defect that sand can not be classified according to the sizes of multiple diameters is overcome, the automatic feeding sand screening machine for civil engineering is provided, and the defect that the sand screening machine in the prior art cannot automatically screen materials and cannot classify the multiple diameters is overcome.

In order to solve the technical problems, the invention adopts the following technical scheme: the utility model provides an automatic feeding screening sand machine for civil engineering, characterized by includes:

the sand screening machine body is used for screening sand in a vibration mode, and a sand inlet is formed in the sand screening machine body;

the sand screening machine comprises a lifting box, a feed inlet is formed in the lower end of the lifting box, a spiral lifting assembly is arranged in the lifting box and comprises a spiral rod arranged in the lifting box, and the upper end of the spiral rod (42) is connected with a lifting motor (42).

In order to realize the function of automatic feeding, set up a promotion case by the screening sand organism, be provided with the lifting unit in the promotion case, through the effect of lifting unit hob, can carry the sand mouth that advances of screening sand organism with the smooth transportation of sand for the sand can be sifted in the screening sand organism.

Preferably, a vibrating motor is arranged on the sand screening machine body, a sand screening net is obliquely arranged in the sand screening machine body, an inclined plate is arranged below the sand screening net, and a sand outlet is formed in the side wall of the sand screening machine body and is close to the lower portion of the inclined plate.

Sand falls the screening sand net after advancing husky mouthful and getting into, and the screening sand net sets to the slope can let the sand carry out automatic the going on the screening sand net and move and screen, and on the sand after the screening fell the hang plate, the hang plate set to the slope form and make the sand can follow the automatic falling of hang plate.

Preferably, the side of the lifting assembly is provided with an opening and closing assembly, the opening and closing assembly comprises a rotating shaft, the lower end of the rotating shaft is connected with a transmission rod, a sliding column is arranged on the transmission rod, a sealing door is arranged outside the feeding hole, the outer end of the sealing door is connected with a transmission frame, and the sliding column is arranged in the transmission frame.

The rotation of axis of rotation can drive the transfer line and rotate, makes the traveller can drive the transmission frame through the rotation of transfer line and moves, and then realizes opening and closing of sealing door, through opening and closing of sealing door for the sealing door can promote the sand in the lifting box, makes the hob can promote sand efficiency higher.

Preferably, the upper end of the lifting box is provided with a discharge hole, the lower end of the discharge hole is connected with a feeding hopper, and the feeding hopper is connected with the sand inlet.

The discharge port is connected with the sand inlet, so that sand is always moved in a closed space, the generation of dust is effectively reduced, the operating environment of workers is better, and the health of the workers is facilitated.

Preferably, a blocking net is obliquely arranged in the sand screening machine body, and the blocking net divides the sand screening machine body into two chambers, namely a negative pressure chamber and a screening chamber; the negative pressure chamber is internally provided with a negative pressure assembly for generating negative pressure, and the screening chamber is internally provided with a classification chamber box.

In order to make the sand screened can carry out more multiple classification, set up negative pressure cavity and screening cavity in the screening sand organism, subassembly in the negative pressure cavity produces the negative pressure, the sand falls into the screening cavity from advancing husky mouth when, effect through the negative pressure produces an absorbent effect to the sand in the horizontal direction, because the difference of the sand diameter of variation in size, the magnitude difference of the negative pressure that produces in the negative pressure cavity that receives, the movement distance that makes the sand of different diameters produce on the horizontal direction is different, and then fall in categorised chamber box, and then realize the classification to the sand of different diameters size.

Preferably, the negative pressure assembly comprises a negative pressure motor, the negative pressure motor is connected with a fan blade through a transmission mechanism, the fan blade is installed on one side far away from the sand inlet, and the fan blade rotates to generate negative pressure through rotation of the negative pressure motor and transmission of the transmission mechanism.

The flabellum produces the negative pressure for sand can carry out the removal of horizontal direction under the effect of negative pressure, makes the sand realize the classification of diameter variation in size.

Preferably, a drip bottle is provided near a side where the fan blade generates negative pressure.

In order to reduce the dust that produces because the effect of negative pressure, set up the drip bottle in flabellum the place ahead, the water droplet receives the effect of flabellum negative pressure from the drip bottle whereabouts for water droplet and flabellum contact, the effect through the flabellum makes the water droplet can carry out atomizing effect, and atomizing water droplet can combine with the dust, and then reaches the purpose that reduces the dust.

Preferably, the classification chamber box is matched with the sand screening machine body and is provided with a plurality of cavities, the cavities are circular rings taking the negative pressure assembly as a circle center, and the cavities are uniformly arranged along the connecting line direction of the sand inlet and the fan blades; the bottom of the cavity is provided with inclined planes which are uniformly distributed along the circular ring.

The sand moving in the horizontal direction due to negative pressure can be collected under the action of the classification cavity box, so that the purpose of classification is achieved; and set the bottom surface of cavity to the inclined plane for sand can move along the inclined plane, and then makes things convenient for the collection of sand.

Preferably, an installation ring is arranged on the inner wall of the lower end of the sand screening machine body, a spring is arranged on the upper end face of the installation ring, and the classification cavity box is movably erected on the spring; the sand screening machine body is provided with a plurality of through holes on the inner wall of the lower side of the classification cavity box.

The through holes are formed in the inner wall of the sand screening machine body at the lower end of the classification cavity box, so that a part of negative pressure can also generate certain wind power through the through holes, meanwhile, the classification cavity box is arranged on the spring, the classification cavity box can generate certain vibration under the action of the wind power, the sand in the classification cavity box can slide downwards along the inclined plane due to the vibration of the classification cavity box, and the collection of the sand is facilitated.

Preferably, the sand inlet is provided with a filtering box, the filtering box is annular, and a filtering box net is arranged in the filtering box.

The filter box enables sand to be preliminarily screened before entering the sand screening machine body, large garbage, stones and other articles are screened, and the annular arrangement can enable the sand to more uniformly fall into the sand screening machine body, so that the subsequent negative pressure screening can achieve a better effect.

Compared with the prior art, the invention has the beneficial effects that: (1) the automatic feeding device can automatically feed materials, and reduces the labor force of workers; (2) the sand classification device can classify the sand with various diameters, so that the sand with a proper size can be selected according to actual practical conditions on the site.

Drawings

FIG. 1 is a cross-sectional view of the present invention;

FIG. 2 is a block diagram of the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 1;

FIG. 4 is a cross-sectional view of the lift box of the present invention at the sealing door;

FIG. 5 is a cross-sectional view of another embodiment of the present invention;

FIG. 6 is a top view of a sorting chamber of the present invention;

FIG. 7 is a block diagram of a filter cassette of the present invention;

in the figure: 1. the sand screening machine comprises a sand screening machine body 11, a sand inlet 12, a sand outlet 13, a sand screening net 14, an inclined plate 15, a blocking net 16, a negative pressure chamber 17 and a screening chamber;

2. a vibration motor;

3. the device comprises a lifting box 31, a feeding hole 311, a sealing door 32, a discharging hole 321, a feeding hopper 33 and a transparent dustproof cover;

4. a spiral lifting component 41, a spiral rod 411, a rubber strip 42 and a lifting motor;

5. the sliding mechanism comprises an opening and closing assembly 51, a transmission shaft 511, a gearwheel, 512, a pinion 52, a transmission rod 521, sliding columns 53, a transmission frame 54 and a limiting block;

6. the negative pressure component 61, the negative pressure motor 62, the fan blades 63, the drip bottle 64, the opening 65 and the wind guide cover;

7. a classification chamber box 71, a cavity 72, a mounting ring 73, a spring 74 and a through hole;

8. and a filter box 81 and a filter box net.

Detailed Description

The technical scheme of the invention is further described in detail by the following specific embodiments in combination with the attached drawings:

example 1: referring to fig. 1 to 4, an automatic feeding sand screening machine for civil engineering, characterized by comprising:

the sand screening machine body 1 is used for screening sand in a vibration mode, and a sand inlet 11 is formed in the sand screening machine body 1;

the lifting box 3 is used for transporting sand into the sand screening machine body 1, the lower end of the lifting box 3 is provided with the feed inlet 31, the spiral lifting assembly 4 is arranged in the lifting box 3, and the spiral lifting assembly 4 comprises a spiral rod 41 arranged in the lifting box 3.

In order to realize the function of automatic feeding, set up a lifting box 3 by screening sand organism 1, be provided with lifting unit 4 in the lifting box 3, through the effect of the hob 41 of lifting unit 4, can be with the smooth sand of transporting into sand inlet 11 of screening sand organism 1 for the sand can be sifted in screening sand organism 1.

The sand screening machine body 1 is provided with a vibration motor 2, a sand screening net 13 is obliquely arranged in the sand screening machine body 1, an inclined plate 14 is arranged below the sand screening net 13, and a sand outlet 12 is arranged on the side wall of the sand screening machine body 1 below the inclined plate 14; the lower extreme of sieve sand net 13 slope end is provided with an export and is not drawn, and above-mentioned export staggers in vertical direction with play sand mouth 12 position, and this export makes the screening after remain on sieve sand net 13 thick sand can follow above-mentioned exit roll-off, and the sand of roll-off and the sand that comes out from play sand mouth 12 fall in different positions to conveniently collect respectively.

Sand falls sieve sand net 13 after advancing sand mouth 11 and getting into, sieve sand net 13 sets to the slope can let the sand carry out automatic the going on at sieve sand net 13 and move and screen, and the sand after the screening falls on hang plate 14, and hang plate 14 sets to the slope form and makes the sand can follow the automatic falling of hang plate to convenient the collection.

Preferably, the upper end of the screw rod 42 is connected to a lift motor 42.

The lifting motor 42 provides power to the screw rod so that the screw rod 41 can rotate and further sand can be lifted.

The side of the lifting component 4 is provided with an opening and closing component 5, the opening and closing component 5 comprises a rotating shaft 51, the rotating shaft 51 is arranged in parallel with the screw rod 41, the lower end of the rotating shaft 51 is connected with a transmission rod 52, a sliding column 521 is arranged on the transmission rod 52, a sealing door 311 is arranged outside the feed inlet 31, the outer end of the sealing door 311 is connected with a transmission frame 53, and the sliding column 52 is arranged in the transmission frame 53.

Rotation of axis of rotation 51 can drive transfer line 52 and rotate, makes traveller 521 can drive transmission frame 53 and move through the rotation of transfer line 52, and then realizes opening and closing of sealing door 311, through opening and closing of sealing door 311 for sealing door 311 can promote the sand in lifting chamber 3, makes hob 41 can promote sand efficiency higher.

The spiral lifting assembly 4 comprises a lifting motor 42, and the upper end of a rotating shaft 51 is connected with the lifting motor 42 through a differential assembly; the differential assembly comprises a large gear 511 arranged at the upper end of the transmission shaft 51, the output end of the lifting motor 42 is connected with a small gear 512, the diameter of the large gear 511 is larger than that of the small gear 512, and the speed of the transmission shaft 51 can be reduced through the matching of the large gear 511 and the small gear 512, so that the sealing door 311 can push more sand.

The transmission shaft 41 is driven by the lifting motor 42, so that the whole machine is more compact in structure.

The upper end of the lifting box 3 is provided with a discharge port 32, the lower end of the discharge port 32 is connected with a feeding hopper 321, and the feeding hopper 321 is connected with the sand inlet 11.

The discharge port 32 is connected with the sand inlet 11, so that sand can move in a closed space all the time, the generation of dust is effectively reduced, the operating environment of workers is better, and the health of the workers is facilitated.

The upper end of the lifting box 3 is provided with a dustproof transparent cover 33 near the discharge hole 32.

Dustproof translucent cover 33 can block the dust on the one hand for the environment of workman's operation is more healthy, has the healthy of workman, can observe the circumstances that lifting box 3 promoted sand simultaneously through transparent dustproof cover 33, prevents too much or too little that the sand promoted.

A limiting block 33 is arranged outside the lifting box 3, and the transmission shaft 51 is arranged in the limiting block 33 in a penetrating mode.

The limiting block 33 plays a role in making the motion of the transmission shaft 51 more stable and ensuring the transmission efficiency of the transmission shaft 51.

The surface of the screw rod 41 is fixedly connected with a rubber strip 411.

The effect that sets up rubber strip 411 can make the sand material promote more stable, prevents that sand material from leaking and influencing lifting efficiency.

This embodiment is when using, at first open the quick-witted screening sand machine, put the screening machine beside the sand, rotation through lift motor 42 drives hob 41 and transmission shaft 51 and rotates, transmission shaft 51's rotation drives sealing door 311 and carries out the motion of switch, the motion of sealing door 3111 switch promotes the sand in lifting box 3, upwards promote the sand through the effect of lifting box 3 internal hob 41, make the sand promote out and get into screening sand body 1 through advancing husky 11 mouths from lifting box 3's upper portion's discharge gate 32, filter through the screening sand net 13 in the screening sand body 1, the filterable sand of screening sand net 13 drops on hang plate 14, later, the play husky mouth 11 through the lower extreme of hang plate 14 drops out.

Example 2: referring to fig. 5 to 7, the present embodiment is basically similar to the above embodiments in structure, except that a blocking net 15 is obliquely arranged in the sand screening machine body 1, and the blocking net 15 divides the inside of the sand screening machine body 1 into two chambers, namely a negative pressure chamber 16 and a screening chamber 17; a negative pressure component 6 for generating negative pressure is arranged in the negative pressure chamber 16, and a classification chamber box 7 is arranged in the screening chamber 17.

The negative pressure component 6 comprises a negative pressure motor 61, the negative pressure motor 61 is connected with a fan blade 62 through a transmission mechanism, the transmission mechanism comprises a first transmission gear arranged at the output shaft connected with the negative pressure motor, the fan blade 62 is arranged at one end of a rotating rod, the other end of the rotating rod is provided with a second transmission gear, the first transmission gear is meshed with the second transmission gear, so that the power of the negative pressure motor can be transmitted to the fan blade 62 through the transmission mechanism, the fan blade 62 is arranged at one side far away from the sand inlet 11, the rotating surface of the fan blade is perpendicular to the horizontal plane when the fan blade rotates, and the fan blade 62 rotates to generate negative pressure through the rotation of the negative pressure motor 61 and the transmission of the transmission mechanism.

In order to generate negative pressure smoothly in the negative pressure chamber 16, air holes are formed in the inner wall of the sand screening machine 1 on the side away from the fan blades in the screening chamber 17, which is not shown, and an opening 64 corresponding to the air holes is formed in the negative pressure chamber 16, so that negative pressure can be generated smoothly.

In order to make the sand screened can carry out more multiple classification, set up negative pressure chamber 16 and screening chamber 17 in the screening sand organism 1, the subassembly in the negative pressure chamber 16 produces the negative pressure, when sand falls into screening chamber 17 from sand inlet 11, effect through the negative pressure produces an absorbent effect to the sand in the horizontal direction, because the difference of the sand diameter of variation in size, the magnitude of the negative pressure who produces in the negative pressure chamber 16 who receives is different, make the movement distance that the sand of different diameters produced on the horizontal direction different, and then fall in categorised chamber box 7, and then realize the classification to the sand of different diameters size.

A drip bottle 63 is provided on a side close to the fan blade 62 where negative pressure is generated, and an air guide cover 65 is provided at the opening 64, and the air guide cover 65 allows wind generated by the fan blade 62 to be blown downward.

In order to reduce dust generated by the action of negative pressure, a drip bottle 63 is arranged in front of the fan blade 62, water drops fall from the drip bottle 63 under the action of the negative pressure of the fan blade 62, so that the water drops are in contact with the fan blade 62, the water drops can be atomized under the action of the fan blade 62, and the atomized water drops can be combined with the dust, so that the purpose of reducing the dust is achieved; the wind scooper 65 can also guide the mist to be gathered downward.

The classification cavity box 7 is matched with the sand screening machine body 1 and is provided with a plurality of cavities 71, the cavities 71 are circular rings taking the negative pressure assembly 6 as the center of a circle, and the cavities 71 are uniformly arranged along the connecting line direction of the sand inlet 11 and the fan blades 62; the bottom of the cavity 71 is provided with inclined surfaces which are uniformly distributed along the circular ring; each cavity 71 is provided with a sand discharge port, not shown, below the inclined surface, and the sand screening machine body 1 is provided with a sand discharge opening corresponding to the sand discharge port, which enables sand to be discharged therefrom.

The sand moving in the horizontal direction due to the negative pressure can be collected under the action of the classification cavity box 7, so that the purpose of classification is achieved; and set the bottom surface of cavity to the inclined plane for sand can move along the inclined plane, and then make things convenient for the collection of sand.

The inner wall of the lower end of the sand screening machine body 1 is provided with a mounting ring 72, the upper end surface of the mounting ring 72 is provided with a spring 73, and the classification cavity box 7 can be movably erected on the spring 73; the sand screen body 1 is provided with a plurality of through holes 74 on the inner wall of the lower side of the classification chamber box 7.

Because set up the through-hole 74 on the inner wall of the screening sand machine body 1 of classification chamber box 7 lower extreme for some negative pressure also can produce certain wind-force through the through-hole 74, simultaneously, because classification chamber box 7 sets up on spring 73, this just makes classification chamber box 7 can produce certain vibration under the effect of wind-force, and the vibration of classification chamber box 7 can make the sand in classification chamber box 7 can slide along the inclined plane downwards, makes things convenient for the collection of sand.

The sand filter is characterized in that a filtering box 8 is arranged at the sand inlet 11, the filtering box 8 is circular, a filtering box net 81 is arranged in the filtering box 8, and in order to generate a better filtering effect, the opening at the lower end of the feeding hopper 321 in the embodiment is the same as the opening of the filtering box 8.

The filter box 8 enables sand to be preliminarily screened before entering the sand screening machine body 1, large garbage, stones and other articles are screened, and the annular arrangement enables the sand to more uniformly fall into the sand screening machine body 1, so that subsequent negative pressure screening can achieve a better effect.

In the embodiment, the fan blades 62 are driven to rotate through the negative pressure motor 61 in the negative pressure component 6 through the transmission mechanism, so that the fan blades 62 can generate negative pressure, when sand falls into the sand screening machine body 1, the sand can move in the horizontal direction to a certain extent under the action of the negative pressure, and due to the fact that the sand is different in weight and size, the sand moves at different distances when receiving the negative pressure in the horizontal direction, can fall into different cavities 71 in the classification cavity box 7, and can be classified into different diameters; meanwhile, the drip bottle 63 is arranged, so that atomization effect can be generated under the action of water drops and the fan blades 62, dust generated by negative pressure is reduced, and the air guide cover 65 is arranged to further prevent the air from being polluted by the dust.

The above embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the scope of the claims.

Claims

1. The utility model provides an automatic feeding screening sand machine for civil engineering, characterized by includes:

the sand screening machine body (1) is used for screening sand in a vibration mode, and a sand inlet (11) is formed in the sand screening machine body (1);

the sand screening machine comprises a lifting box (3) used for conveying sand into a sand screening machine body (1), a feeding hole (31) is formed in the lower end of the lifting box (3), a spiral lifting assembly (4) is arranged in the lifting box (3), the spiral lifting assembly (4) comprises a spiral rod (41) arranged in the lifting box (3), and the upper end of the spiral rod (42) is connected with a lifting motor (42).

2. The automatic feeding sand screening machine for civil engineering as claimed in claim 1, wherein the sand screening machine body (1) is provided with a vibrating motor (2), a sand screening net (13) is obliquely arranged in the sand screening machine body (1), an inclined plate (14) is arranged below the sand screening net (13), and a sand outlet (12) is arranged on the side wall of the sand screening machine body (1) below the inclined plate (14).

3. The automatic feeding sand screening machine for civil engineering according to claim 1, characterized in that the side of the lifting assembly (4) is provided with an opening and closing assembly (5), the opening and closing assembly (5) comprises a rotating shaft (51), the lower end of the rotating shaft (51) is connected with a transmission rod (52), the transmission rod (52) is provided with a sliding column (521), a sealing door (311) is arranged outside the feeding hole (31), the outer end of the sealing door (311) is connected with a transmission frame (53), and the sliding column (52) is arranged inside the transmission frame (53).

4. The automatic feeding sand screen for civil engineering as claimed in claim 1, wherein the lifting box (3) is provided at its upper end with a discharge port (32), the lower end of the discharge port (32) being connected to a feeding hopper (321), the feeding hopper (321) being connected to the sand inlet (11).

5. The automatic feeding sand screen for civil engineering as claimed in claim 1, characterised in that a screen net (15) is obliquely arranged inside the sand screen body (1), said screen net (15) dividing the inside of the sand screen body (1) into two chambers, a negative pressure chamber (16) and a screening chamber (17); the negative pressure component (6) for generating negative pressure is arranged in the negative pressure chamber (16), and the sorting cavity box (7) is arranged in the screening chamber (17).

6. The automatic feeding sand screening machine for civil engineering as claimed in claim 5, characterized in that said negative pressure assembly (6) comprises a negative pressure motor (61), said negative pressure motor (61) is connected with a fan blade (62) through a transmission mechanism, said fan blade (62) is installed on the side far away from said sand inlet (11), the rotation of the negative pressure motor (61) and the transmission of the transmission mechanism make the fan blade (62) rotate to generate negative pressure.

7. The machine according to claim 6, characterized in that a drip bottle (63) is provided close to the side of the blades (62) where the negative pressure is generated.

8. The automatic feeding sand screen for civil engineering as claimed in claim 5, characterized in that said classification chamber (7) is adapted to said sand screen body (1) and is provided with a plurality of cavities (71), said cavities (71) are circular with said negative pressure component (6) as the center, said cavities (71) are arranged uniformly along the direction of the line connecting said sand inlet (11) and said fan blades (62); the bottom of the cavity (71) is provided with inclined surfaces which are uniformly distributed along the circular ring.

9. The automatic feeding sand screen for civil engineering as claimed in claim 7, wherein the inner wall of the lower end of the sand screen body (1) is provided with a mounting ring (72), the upper end face of the mounting ring (72) is provided with a spring (73), the classifying chamber box (7) is movably erected on the spring (73); the sand screening machine body (1) is provided with a plurality of through holes (74) on the inner wall of the lower side of the classification cavity box (7).

10. The automatic feeding sand screen for civil engineering according to any one of claims 5 to 9, characterized in that a filtering box (8) is arranged at the sand inlet (11), the filtering box (8) is circular ring-shaped, and a filtering box net (81) is arranged in the filtering box (8).