CN113426515B

CN113426515B - Double-roller sand making machine capable of changing positions and rolling stones

Info

Publication number: CN113426515B
Application number: CN202110627458.XA
Authority: CN
Inventors: 祝光云; 祝鹤槐
Original assignee: Zhejiang Chentai Machinery Manufacturing Co ltd
Current assignee: Zhejiang Chentai Machinery Manufacturing Co ltd
Priority date: 2021-06-05
Filing date: 2021-06-05
Publication date: 2022-08-02
Anticipated expiration: 2041-06-05
Also published as: CN113426515A

Abstract

The invention relates to a double-roller sand making machine capable of performing transposition grinding on stones, which comprises two grinding cylinders and a pressure sensor for detecting extrusion force between the two grinding cylinders, wherein two axial ends of one grinding cylinder are respectively provided with a gear set, each gear set comprises a driving gear, an intermediate gear meshed with the driving gear and an internal gear sleeved on the driving gear, the internal gear is sleeved on the grinding cylinder and is in clutch connection with the grinding cylinder through a first clutch, the driving gear is also in clutch connection with a rack through a second clutch, the intermediate gear is connected with the rack, and outer gear rings of the two gear sets are connected together through two pull rods uniformly distributed along the circumferential direction of the grinding cylinder. The stone-making machine has the advantages of reversing and rolling stuck stones and transposition and rolling the stones, and solves the problem that the produced sand has larger granularity and high component proportion caused by the fact that the sand needing to be rolled by larger force passes through due to the fact that the existing sand-making machine is crushed and widened.

Description

Double-roller sand making machine capable of changing positions and rolling stones

Technical Field

The invention relates to a sand making machine, in particular to a double-roller sand making machine capable of performing transposition grinding on stones.

Background

A sand maker is a mechanical device used to break stone into sand. The structure of the sand making machine has two types, one is a hammer crusher, the other is a double-roller machine (hereinafter referred to as double-roller sand making machine), the hammer crusher has many wearing parts, large energy consumption, much dust and uneven fineness. The roller pair sand making machine can avoid the defects of much dust and uneven fineness. The patent document with Chinese patent No. 2010202399225, publication No. CN201791554U, entitled "drive mechanism of double-roller sand making machine" discloses a double-roller sand making machine, the crushing of stone into sand by the double-roller sand making machine is realized by rolling a pair of crushing cylinders (also called rollers), the crushing cylinder of the initial double-roller sand making machine is realized by arranging a chain wheel at one end of the crushing cylinder, then reducing the speed of the output of a motor by a speed reducer and then driving the chain wheel by a chain, therefore, the defects of poor efficiency, large abrasion, small bearing capacity, small impact resistance, large vibration and appearance volume and short continuous operation life exist; the present applicant has devised for this purpose an internally driven pair roller sand mill as disclosed in patent application No. 2016101635735. The existing pair-roller sand making machine has the following defects: providing a separation interval for the crushing cylinder (i.e. widening of the crushing interval) for compression of the air chamber when stuck by stones, can result in the sand being over-sized; the produced sand cannot be separated in thickness.

Disclosure of Invention

The invention further aims to provide a double-roller type sand making machine capable of reversing and rolling stuck stones and realizing transposition rolling of the stones, and solves the problem that the existing sand making machine is large in particle size and high in component proportion in the made sand due to the fact that the sand needing to be rolled by large force passes through the broken and widened sand.

The second purpose of the invention is to further provide a double-roller sand making machine capable of performing thickness separation on the made sand by using a grinding cylinder to provide power, and capable of performing transposition grinding on stones, so that the problem that the made sand cannot be subjected to thickness separation by using the existing internal drive type sand making machine is solved.

The technical problem is solved by the following technical scheme: a double-roller sand making machine capable of changing positions and rolling stones comprises a machine frame, wherein the machine frame is provided with two crushing cylinders and a driving structure for driving the crushing cylinders to rotate, a rolling gap is formed between the two crushing cylinders, the double-roller sand making machine also comprises a pressure sensor for detecting the extrusion force between the two crushing cylinders, two gear sets are respectively arranged at two axial ends of one crushing cylinder, the gear set comprises a driving gear, a plurality of intermediate gears which are meshed on the driving gear and distributed along the circumferential direction of the driving gear, and an inner gear ring sleeved on the driving gear, the driving gear is sleeved on the crushing barrel and is connected with the crushing barrel in a clutchable manner through a first clutch, the driving gear is also connected with the rack in a clutchable way through a second clutch, the intermediate gear is connected with the rack, and the outer gear rings of the two gear sets are connected together through two pull rods which are uniformly distributed along the circumferential direction of the crushing barrel and can pass through the rolling gap; in an initial state, the pull rod and the rolling gap are staggered in the vertical direction, the second clutch is closed, and the first clutch is disengaged, so that the driving gear and the rack are fixed together and disengaged from the crushing barrel; when the pressure sensor detects that the extrusion force between the crushing barrels is larger than a set value, the first clutch is closed and the second clutch is disengaged, so that the driving gear and the crushing barrels are fixed together to rotate 180 degrees, then the second clutch is disengaged and the first clutch is disengaged. When stones are clamped and not crushed in time, the pull rod can move upwards from the lower part of the rolling gap to the upper part of the rolling gap, so that the stones clamped in the rolling gap can move upwards to be rolled, and the stones can be crushed conveniently.

Preferably, in the initial state, one of the tie rods is located on a side of the crushing cylinders directly above the crushing cylinder facing the crushing gap, and stones to be crushed located between the two crushing cylinders are pressed against the tie rods during crushing. The timeliness of the pull rod when the pull rod stops rotating along with the crushing cylinder can be improved.

Preferably, the pull rod abuts against an outer peripheral surface of the crushing cylinder. The upward movement of the tie rod can be made more reliable in promoting the upward and rotational movement of stones that are set open in the crushing gap.

Preferably, when the pull rod is positioned above the rolling gap and on one side of the crushing cylinder facing the rolling gap, the side surface of the pull rod, which is far away from the crushing cylinder, is an inclined surface which inclines upwards. The obstruction of the pull rod when being pulled upwards can be small.

Preferably, the pull rod is connected with the inner gear ring through a position adjusting mechanism, the position adjusting mechanism comprises a connecting block arranged on the inner gear ring, a threaded rod penetrating through the connecting block and extending along the radial direction of the inner gear ring, and two adjusting nuts in threaded connection with the threaded rod, the two adjusting nuts are distributed on two sides of the connecting block, and one end of the threaded rod is connected with the pull rod. During the use, after the crushing barrel is worn and torn, through loosening adjusting nut, remove the threaded rod and make the pull rod butt on crushing barrel again, prevent that the pull rod from interfering the rolling clearance adjustment between the crushing barrel and recovering and the pull rod is damaged.

Preferably, the end face of the inner gear ring is provided with a gear ring part limiting groove extending along the radial direction of the inner gear ring, and the pull rod is provided with a limiting slide block connected in the gear ring part limiting groove in a sliding manner. The reliability of the pull rod during connection can be improved.

The invention also comprises a screen positioned below the two grinding cylinders and used for receiving the sand falling from the grinding gap, and a screen translation mechanism for driving the screen to reset and translate along the distribution direction of the two grinding cylinders, wherein one end of the screen along the axial direction of the grinding cylinders is higher, the other end of the screen is lower, the lower end of the screen is butted with the feeding end of the blanking groove, a fine material collecting tank used for receiving the sand falling from the screen holes of the screen is arranged below the screen, the screen translation mechanism comprises two driving pairs, each driving pair comprises a stop block and a deflector rod for driving the stop block, the stop blocks in the two driving pairs are connected to the screen and distributed along the movement direction of the screen, the deflector rods in the two driving pairs are correspondingly connected to the two grinding cylinders one by one, the deflector rods rotate along with the grinding cylinders, and when the deflector rods in one driving pair are butted with the stop blocks, the deflector rods in the other driving pair are disengaged from the stop blocks, when the shifting rods in the two driving pairs are disengaged from the stop blocks, only one stop block in the driving pair is located at a position where the shifting rods can be shifted. When the device is used, the screen is driven by two driving pairs to translate vertically back and forth in turn. The power source can be shared in a compact manner. The manufactured sieve can be subjected to coarse and fine separation.

Preferably, the shifting lever comprises a first section and a second section, one end of the first section is fixedly connected with the crushing barrel, the other end of the first section is provided with a sliding hole, one end of the second section is arranged in the sliding hole in a penetrating mode, and a shifting lever extending spring for driving the second section to extend out of the sliding hole is arranged in the sliding hole. The screen can be translated back and forth greatly under the condition that the height of the screen from the crushing cylinder is lower.

Preferably, an inner flanging is arranged at the opening end of the sliding hole, an outer flanging is arranged at the end, located in the sliding hole, of the second section, and the inner flanging is matched with the outer flanging to prevent the second section from being pulled out of the sliding hole.

Preferably, the baffle plate is provided with a baffle plate supporting roller, the peripheral surface of the baffle plate supporting roller exceeds the upper end surface of the baffle plate, the peripheral surface of the baffle plate supporting roller exceeds the side surface, facing the shifting rod, of the baffle plate when the shifting rod is close to the baffle plate, one end, far away from the crushing barrel, of the shifting rod is provided with a shifting rod supporting roller, the peripheral surface of the shifting rod supporting roller exceeds the end surface, far away from the end of the crushing barrel, of the shifting rod, and the peripheral surface of the shifting rod supporting roller exceeds the side surface, facing the baffle plate, of the shifting rod when the shifting rod is close to the baffle plate. According to the scheme, the driving lever and the stop block can be in contact driving in the whole process only through the supporting roller, so that the abrasion caused when the driving lever and the stop block are in contact can be reduced.

Preferably, the axial direction of the deflector rod supporting roller is parallel to the axial direction of the stopper portion supporting roller, and the axial direction of the stopper portion supporting roller is parallel to the axial line of the crushing barrel. The contact between the stop block and the shifting rod can be in line contact.

Preferably, the baffle plate is provided with a baffle plate arc surface which is coaxial with the baffle plate support roller, and the baffle plate arc surface is provided with a plurality of baffle plate support balls which are distributed along the circumferential direction of the baffle plate support roller and supported on the circumferential surface of the baffle plate support roller; the shifting lever is provided with a shifting lever arc-shaped surface which is coaxial with the shifting lever support idler wheel, and the shifting lever arc-shaped surface is provided with a plurality of shifting lever support balls which are circumferentially distributed along the shifting lever support idler wheel and supported on the circumferential surface of the shifting lever support idler wheel. The stress of the wheel shaft of the supporting roller can be reduced. Preventing the generation of bending deformation.

The sieve support device also comprises two guide support chutes extending along the horizontal moving direction of the sieve, wherein one guide support chute is positioned below the high end of the sieve, the other guide support chute is positioned at the low end of the sieve, two rows of sieve support feet which are arranged in the two guide support chutes in a one-to-one correspondence manner are arranged on the sieve, sieve part support rolling balls supported on the bottom wall of the guide support chutes are arranged on the lower end surface of each sieve support foot, bearings are sleeved on the sieve support feet, and the peripheral surface of each sieve support foot is abutted with the side walls of the guide support chutes through the bearings. The smoothness and the prolonged service life of the screen during translation can be improved.

The sieve mesh dredging mechanism comprises a dredging shaft positioned below the sieve, a dredging motor driving the dredging shaft to rotate and two racks fixed together with the sieve, two ends of the dredging shaft are respectively provided with a walking gear, the two walking gears are meshed on the two racks in a one-to-one correspondence manner, the dredging shaft is provided with a plurality of top rows uniformly distributed along the circumferential direction of the dredging shaft, tops in the same row of top rows are distributed along the axial direction of the dredging shaft, tops in adjacent top rows are aligned along the circumferential direction of the dredging shaft, sieve meshes of the sieve are distributed in a rectangular array manner, and the tops in the same row of top rows are positioned on the same plane vertical to the dredging shaft in a one-to-one correspondence manner; when the dredging shaft rotates 360 degrees/N from the position where the sieve pores in the same row of sieve pores of the tops in one row of the tops are aligned one by one, the tops in the next row of the tops are aligned one by one with the sieve pores in the next row of sieve pores. During the use, the dredge roller reciprocates under the drive of mediation motor and rotates, rotates in-process ejector pin and carries out row by row top mediation to the sieve mesh so.

Preferably, the lower end of each sieve pore is provided with a pit, and the opening area of each sieve pore is gradually increased from bottom to top. The size of the ejector rod can be equal to the aperture of the part of the sieve pore for controlling the granularity of the sand, and the sieve can be dredged when the thickness of the sieve is thick.

Preferably, a guide sliding groove extending along the extending direction of the rack is formed in the side face, adjacent to the side face, provided with the teeth, of the rack, and a guide sliding block penetrating in the limit sliding groove is arranged on the shell of the dredging motor. The smoothness of the dredging shaft during reciprocating rolling can be improved.

Compared with the prior art have influence beneficial effect: the manufactured sand can be subjected to coarse and fine separation; the thickness separation is driven by matching the crushing cylinder with a related structure, so that the structure is compact; when the roller compaction is increased due to the fact that stones are clamped, the clamped stones can be lifted to be turned over so that the stones can be crushed better, and the situation that large stones are mixed into the sand can be avoided; can dredge the sieve pores.

Drawings

FIG. 1 is a schematic diagram of a first embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the grinding cylinder on the right side of FIG. 1;

FIG. 3 is a partial schematic view of the second embodiment;

FIG. 4 is a right side view of the third embodiment of the present invention showing the shift lever and the stop in a driving pair just touching each other;

FIG. 5 is an enlarged partial schematic view at C of FIG. 4;

FIG. 6 is an enlarged partial schematic view of FIG. 5 at D;

FIG. 7 is an enlarged partial schematic view at E of FIG. 6;

FIG. 8 is a schematic front view of a sieve in the third embodiment;

fig. 9 is a partially enlarged schematic view at F of fig. 8;

FIG. 10 is a schematic right side view of a third embodiment of the present invention with the shifter lever and the stop in both drive pairs separated and with no gear train shown;

FIG. 11 is a right side view of the third embodiment of the present invention with the shift lever and the stop member just touching each other and without the gear set shown;

FIG. 12 is a schematic right view of a screen according to the fourth embodiment;

FIG. 13 is a schematic cross-sectional view B-B of FIG. 12;

in the figure: the fine material collecting tank 21, a stop 22, a deflector rod 23, a first section 24, a second section 25, a deflector rod extension spring 26, an inward flange 27, an outward flange 28, a stop part supporting roller 29, an upper end surface 30 of the stop, a side surface 31 of the stop facing to a deflector rod when the deflector rod approaches the stop, a deflector rod supporting roller 32, an end surface 33 of the deflector rod far away from the end of the crushing tank, a side surface 34 of the deflector rod facing to a stop when the deflector rod approaches the stop, a stop part arc surface 35, a stop part supporting ball 36, a deflector rod arc surface 37, a deflector rod supporting ball 38, a guide supporting chute 39, a screen supporting foot 40, a screen part supporting ball 41, a bearing 42, a dredging shaft 43, a dredging motor 44, a rack 45, a walking gear 46, a top 47, a sieve mesh 48, a pit 49, a guide chute 50, a guide slide block 51, a driving gear 52, an intermediate gear 53, a mesh 53, a concave pits 49, a deflector rod 23, a deflector rod supporting roller 32, a deflector rod supporting ball, a bearing, a baffle rod supporting ball 33, a baffle rod supporting ball, a baffle shaft, a baffle plates, a baffle shaft, a baffle motor, a baffle plates, a baffle plate supporting roller, a bearing, a baffle plate supporting roller, a bearing, a baffle plate supporting roller, a motor, a baffle plate supporting roller, a bearing, a baffle plate supporting roller, a motor, a bearing, a motor, The device comprises an inner gear ring 54, a first clutch 55, a second clutch 56, a pull rod 57, a side face 58 of the pull rod far away from the crushing barrel, a connecting block 59, a threaded rod 60, an adjusting nut 61, a gear ring part limiting groove 62 and a limiting slide block 63.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

First embodiment, referring to fig. 1 and 2, a pair-roller type sand making machine capable of performing transposition grinding on stones comprises a frame 1, wherein the frame is provided with two crushing cylinders 2 and a driving structure for driving the crushing cylinders to rotate, and a grinding gap 4 is formed between the two crushing cylinders. The invention also comprises a pressure sensor for detecting the extrusion force between two crushing barrels, two gear sets are respectively arranged at two axial ends of one crushing barrel, each gear set comprises a driving gear 52, a plurality of intermediate gears 53 which are meshed on the driving gear and distributed along the circumferential direction of the driving gear, and an inner gear ring 54 which is sleeved on the driving gear, the driving gear is sleeved on the crushing barrel and is connected with the crushing barrel in a clutchable way through a first clutch 55, the driving gear is also connected with the frame in a clutchable way through a second clutch 56, the intermediate gears are connected with the frame, and the outer gear rings of the two gear sets are connected together through two pull rods 57 which are uniformly distributed along the circumferential direction of the crushing barrel and can pass through rolling gaps; in an initial state, the pull rod and the rolling gap are staggered in the vertical direction, the second clutch is closed, and the first clutch is disengaged, so that the driving gear is fixed with the rack and disengaged from the crushing barrel; when the pressure sensor detects that the extrusion force between the crushing barrels is larger than a set value, the first clutch is closed and the second clutch is disengaged, so that the driving gear and the crushing barrels are fixed together to rotate 180 degrees, then the second clutch is disengaged and the first clutch is disengaged. In the initial state, one pull rod is positioned on one side, facing the rolling gap, right above the crushing cylinders, and stones to be crushed positioned between the two crushing cylinders are pressed on the pull rod during crushing. The pull rod is connected with the outer peripheral surface of the crushing barrel in an abutting mode. When the pull rod is positioned above the rolling gap and on one side of the crushing cylinder facing the rolling gap, the side surface 58 of the pull rod on one side far away from the crushing cylinder is an inclined surface which inclines upwards.

The second embodiment is different from the first embodiment in that:

referring to fig. 3, the pull rod is connected with the inner gear ring through a position adjusting mechanism, the position adjusting mechanism comprises a connecting block 59 arranged on the inner gear ring, a threaded rod 60 penetrating the connecting block and extending along the radial direction of the inner gear ring, and two adjusting nuts 61 screwed on the threaded rod, the two adjusting nuts are distributed on two sides of the connecting block, and one end of the threaded rod is connected with the pull rod. The end face of the inner gear ring is provided with a gear ring part limiting groove 62 extending along the radial direction of the inner gear ring, and the pull rod is provided with a limiting slide block 63 connected in the gear ring part limiting groove in a sliding manner.

The third embodiment is different from the second embodiment in that:

referring to fig. 4 to 11, the invention further comprises a screen 19 which is positioned below the two grinding cylinders and used for receiving the sand falling from the grinding gap, and a screen translation mechanism for driving the screen to reset and translate along the distribution direction of the two grinding cylinders, wherein one end of the screen along the axial direction of the grinding cylinders is higher, the other end of the screen is lower, the lower end of the screen is butted with the feeding end of the blanking chute 20, and a fine material collecting tank 21 used for receiving the sand falling from the screen holes of the screen is arranged below the screen. The screen translation mechanism comprises two driving pairs, each driving pair comprises a stop block 22 and a driving stop block shifting lever 23, the stop blocks in the two driving pairs are connected to the screen and distributed along the moving direction of the screen, namely the distribution direction of the two crushing barrels, the shifting levers in the two driving pairs are fixedly connected to the two crushing barrels in a one-to-one correspondence mode, and the shifting levers extend along the radial direction of the crushing barrels. The deflector rods rotate along with the crushing barrel, when the deflector rod in one driving pair is abutted to the stop block, the deflector rod in the other driving pair is separated from the stop block, and when the deflector rods in the two driving pairs are separated from the stop block, only one stop block in the driving pair is positioned at the position where the deflector rod can be moved. The deflector rod comprises a first section 24 and a second section 25, one end of the first section is fixedly connected with the crushing barrel, the other end of the first section is provided with a sliding hole, one end of the second section is arranged in the sliding hole in a penetrating mode, and a deflector rod extending spring 26 for driving the second section to extend out of the sliding hole is arranged in the sliding hole. The open end of the slide hole is provided with an inner flanging 27, the end of the second section in the slide hole is provided with an outer flanging 28, and the inner flanging is matched with the outer flanging to prevent the second section from being pulled out of the slide hole. Be equipped with dog portion supporting roller 29 on the dog, dog portion supporting roller's global top end 30 that surpasss the dog, dog portion supporting roller's global side 31 that surpasss the orientation poking rod side of dog when the driving lever is close to the dog that surpasss of dog, the one end that crushing barrel was kept away from to the driving lever is equipped with driving lever portion supporting roller 32, the global terminal surface 33 that the crushing barrel end was kept away from to the driving lever that surpasss of driving lever portion supporting roller, the global side 34 that surpasss the orientation dog side of driving lever when the driving lever is close to the dog that surpasss of driving lever portion supporting roller. The axial direction of the deflector rod part supporting roller is parallel to the axial direction of the stop block part supporting roller, and the axial direction of the stop block part supporting roller is parallel to the axial line of the crushing barrel. The baffle is provided with a baffle arc surface 35 which is coaxial with the baffle support idler wheel, and the baffle arc surface is provided with a plurality of baffle support balls 36 which are distributed along the circumference of the baffle support idler wheel and supported on the circumference of the baffle support idler wheel; the deflector rod is provided with a deflector rod arc surface 37 which is coaxial with the deflector rod support roller, and the deflector rod arc surface is provided with a plurality of deflector rod support balls 38 which are circumferentially distributed along the deflector rod support roller and supported on the circumferential surface of the deflector rod support roller. And the fine material collecting device is also provided with two guide supporting chutes 39 extending along the horizontal moving direction of the screen, wherein one guide supporting chute is fixed with the frame, and the other guide supporting chute is fixed on the fine material collecting tank. The guide supporting chute fixed on the frame is positioned below the lower end of the sieve, and the guide supporting chute fixed on the fine material collecting tank is positioned below the high end of the sieve. Two rows of sieve supporting feet 40 which are arranged in the guide supporting chutes in a penetrating mode in a one-to-one correspondence mode are arranged on the sieve, sieve part supporting rolling balls 41 which are supported on the bottom wall of the guide supporting chutes are arranged on the lower end face of each sieve supporting foot, bearings 42 are sleeved on the sieve supporting feet, and the peripheral face of each sieve supporting foot is abutted to the side wall of each guide supporting chute through the bearings.

The fourth embodiment is different from the third embodiment in that:

referring to fig. 12 and 13, the sieve mesh dredging device further comprises a dredging shaft 43 located below the sieve, a dredging motor 44 driving the dredging shaft to rotate, and two racks 45 fixed together with the sieve, two ends of the dredging shaft are respectively provided with a walking gear 46, the two walking gears are meshed on the two racks in a one-to-one correspondence manner, the dredging shaft is provided with a plurality of top rows uniformly distributed along the circumferential direction of the dredging shaft, the tops 47 in the top row in the same row are distributed along the axial direction of the dredging shaft, the tops in the adjacent top rows are aligned along the circumferential direction of the dredging, the sieve meshes of the sieve are distributed in a rectangular array, and the tops in the top rows in the same row are correspondingly positioned on the same plane perpendicular to the dredging shaft; when the dredging shaft rotates 360 DEG/N from the position where the screen holes in the same row of the top heads in one row are aligned one by one, the top heads in the next row of the top heads are aligned one by one with the screen holes in the next row, and N is the row number of the top head rows. When the tips are aligned with the holes in the same row of holes in the tip row one to one, the upper ends of the tips extend upward beyond the holes 48. The lower end of the sieve mesh is provided with a pit 49, and the opening area of the sieve mesh is gradually increased from bottom to top. And a guide sliding groove 50 extending along the extension direction of the rack is arranged on the side surface adjacent to the side surface of the rack provided with the teeth, and a guide sliding block 51 arranged in the limit sliding groove in a penetrating manner is arranged on the shell of the dredging motor.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A double-roller sand making machine capable of changing positions and rolling stones comprises a frame, wherein the frame is provided with two crushing barrels and a driving structure for driving the crushing barrels to rotate, a rolling gap is formed between the two crushing barrels, the double-roller sand making machine also comprises a pressure sensor for detecting the extrusion force between the two crushing barrels, two axial ends of one crushing barrel are respectively provided with a gear set, the gear set comprises a driving gear, a plurality of intermediate gears which are meshed on the driving gear and distributed along the circumferential direction of the driving gear, and an inner gear ring sleeved on the driving gear, the driving gear is sleeved on the crushing barrel and is connected with the crushing barrel in a clutchable manner through a first clutch, the driving gear is also connected with the rack in a clutchable way through a second clutch, the intermediate gear is connected with the rack, and the outer gear rings of the two gear sets are connected together through two pull rods which are uniformly distributed along the circumferential direction of the crushing cylinder and can pass through the rolling gap; in an initial state, the pull rod and the rolling gap are staggered in the vertical direction, the second clutch is closed, and the first clutch is disengaged, so that the driving gear and the rack are fixed together and disengaged from the crushing barrel; when the pressure sensor detects that the extrusion force between the crushing barrels is larger than a set value, the first clutch is closed and the second clutch is disengaged, so that the driving gear and the crushing barrels are fixed together to rotate 180 degrees, then the second clutch is disengaged and the first clutch is disengaged.

2. A double-roller stone mill capable of transposing and rolling stones according to claim 1, wherein in an initial state one of the tie rods is located on a side directly above the crushing cylinders facing the rolling gap, and stones to be crushed located between the two crushing cylinders are pressed against the tie rods during crushing.

3. A double-roller stone mill capable of transposing and rolling stones as claimed in claim 2, wherein said pulling rod abuts against an outer peripheral surface of said crushing cylinder.

4. A double-roller sand making machine capable of transposing and rolling stones according to claim 1, 2 or 3, wherein when the pull rod is positioned above the rolling gap and on the side of the crushing cylinder facing the rolling gap, the side of the pull rod on the side away from the crushing cylinder is an inclined surface inclined upwards.

5. A double-roller sand making machine capable of changing and rolling stones according to claim 1, 2 or 3, characterized in that the pull rod is connected with the inner gear ring through a position adjusting mechanism, the position adjusting mechanism comprises a connecting block arranged on the inner gear ring, a threaded rod penetrating the connecting block and extending along the radial direction of the inner gear ring, and two adjusting nuts connected to the threaded rod in a threaded manner, the two adjusting nuts are distributed on two sides of the connecting block, and one end of the threaded rod is connected with the pull rod.

6. A double-roller sand making machine capable of transposing and rolling stones according to claim 5, wherein a gear ring part limiting groove extending along the radial direction of the inner gear ring is formed in the end surface of the inner gear ring, and the pull rod is provided with a limiting slide block connected in the gear ring part limiting groove in a sliding manner.

7. The pair-roller sand making machine capable of transposing and rolling stones according to claim 1, further comprising a screen positioned below the two crushing drums and receiving the sand falling from the rolling gap and a screen translation mechanism for driving the screen to perform a repositioning translation along the distribution direction of the two crushing drums, wherein the screen has a higher end and a lower end along the axial direction of the crushing drums, the lower end of the screen is butted with the feeding end of the blanking tank, a fine material collecting tank for receiving the sand falling from the screen holes of the screen is positioned below the screen, the screen translation mechanism comprises two driving pairs, each driving pair comprises a stopper and a driving stopper rod, the stoppers of the two driving pairs are connected to the screen and distributed along the movement direction of the screen, the driving rods of the two driving pairs are connected to the two crushing drums in a one-to-one correspondence manner, and the driving rods rotate along with the crushing drums, when the shifting rod in one driving pair is abutted to the stop block, the shifting rod in the other driving pair is separated from the stop block, and when the shifting rods in the two driving pairs are separated from the stop block, only one stop block in the driving pair is located at a position where the shifting rod can shift.

8. The double-roller sand making machine capable of transposing and rolling stones according to claim 7, wherein the shifting lever comprises a first section and a second section, one end of the first section is fixedly connected with the crushing cylinder, the other end of the first section is provided with a sliding hole, one end of the second section is arranged in the sliding hole in a penetrating manner, and a shifting lever extension spring for driving the second section to extend out of the sliding hole is arranged in the sliding hole.

9. The pair-roller sand making machine capable of performing transposition grinding on stones according to claim 7, wherein a stopper portion supporting roller is arranged on the stopper, the peripheral surface of the stopper portion supporting roller exceeds the upper end surface of the stopper, the peripheral surface of the stopper portion supporting roller exceeds the side surface, facing the shifting rod, of the stopper when the shifting rod is close to the stopper, the end, far away from the crushing barrel, of the shifting rod is provided with a shifting rod portion supporting roller, the peripheral surface of the shifting rod portion supporting roller exceeds the end surface, far away from the crushing barrel, of the shifting rod, and the peripheral surface of the shifting rod portion supporting roller exceeds the side surface, facing the stopper, of the shifting rod when the shifting rod is close to the stopper.

10. The pair-roller sand making machine capable of transposing and rolling stones according to claim 7, further comprising a sieve pore dredging mechanism, wherein the sieve pore dredging mechanism comprises a dredging shaft positioned below the sieve, a dredging motor for driving the dredging shaft to rotate, and two racks fixed together with the sieve, two ends of the dredging shaft are respectively provided with a walking gear, the two walking gears are meshed on the two racks in a one-to-one correspondence manner, the dredging shaft is provided with a plurality of top rows uniformly distributed along the circumferential direction of the dredging shaft, the tops in the same top row are distributed along the axial direction of the dredging shaft, the tops in adjacent top rows are aligned along the circumferential direction of dredging, the sieve pores of the sieve are distributed in a rectangular array, and the sieve pores in the same row of sieve pores in the same top row are positioned on the same plane perpendicular to the dredging shaft in a one-to-one correspondence manner; when the dredging shaft rotates 360 degrees/N from the position where the sieve pores in the same row of sieve pores of the tops in one row of the top rows are aligned one by one, the tops in the next row of the top rows are aligned one by one with the sieve pores in the next row of sieve pores, and N is the row number of the top rows.