CN117324573A - Casting device and casting method for nodular cast iron production - Google Patents

Abstract

The invention relates to the technical field of pipeline processing, in particular to a casting device and a casting method for spheroidal graphite cast iron production, wherein the casting device comprises a base, a heat preservation furnace, a liquid discharge groove and a pipe die, wherein the left end of the upper surface of the base is fixedly connected with the bottom of the heat preservation furnace, the heat preservation furnace keeps spheroidal graphite cast iron liquid warm, the left end of the liquid discharge groove is fixedly connected with the bottom end of the right side wall of the heat preservation furnace, the liquid discharge groove conducts spheroidal graphite cast iron liquid drainage, the casting device further comprises a sliding table, a forming mechanism, an audible and visual alarm and a quality monitoring mechanism, and the sliding table is fixedly connected to the right side of the upper surface of the base; the forming mechanism is fixedly connected to the top of the sliding table, the forming mechanism moves left and right through the sliding table, and the pipe die is arranged in the inner cavity of the forming mechanism; the audible and visual alarm is arranged on the upper surface of the forming mechanism. The pipe die is replaced in a time-saving and labor-saving mode, the production efficiency of the nodular cast iron pipe is further improved, centrifugal casting monitoring of the pipe die is achieved, the quality monitoring purpose of the nodular cast iron pipe is achieved, and the yield is improved.

Description

Casting device and casting method for nodular cast iron production

Technical Field

The invention relates to the technical field of pipeline processing, in particular to a casting device and a casting method for nodular cast iron production.

Background

The spheroidal graphite cast iron pipe is a pipe which is cast by casting molten iron with more than 18 numbers through a centrifugal spheroidal graphite cast iron machine at high speed after adding a nodulizer, and is called a spheroidal graphite cast pipe, a spheroidal graphite cast iron pipe and the like for short. The material is mainly used for conveying tap water and is an ideal material for selecting a tap water pipeline;

the spheroidal graphite cast iron pipe adopts the centrifugal casting method, drain spheroidal graphite cast iron liquid into the pipe die, produce centrifugal force through the pipe die rotation, and make spheroidal graphite cast iron liquid evenly distributed in the pipe die inner wall, obtain spheroidal graphite cast iron pipe after cooling, in prior art, the pipe die often adopts traditional bolt fastening, the pipe die is as the wearing part in the cold die manufacturing process, to the change of pipe die waste time and energy, it is difficult to further promote spheroidal graphite cast iron pipe production efficiency, because the pipe die and the spheroidal graphite cast iron pipe quality of shaping at pipe die inner wall are great, mechanical wear is also great, with the operating time increases, the pipe die eccentricity can grow gradually, cause the pipe die centrifugal force unbalance, easily lead to spheroidal graphite cast iron pipe wall thickness inconsistent, consequently, it is necessary to propose a casting device for spheroidal graphite cast iron production that shaping quality is high.

Disclosure of Invention

The invention aims to overcome the defects that the tube die is time-consuming and labor-consuming to replace and the molding quality of a nodular cast iron tube cannot be monitored in the prior art, and the technical problem to be solved by the invention is a casting device and a casting method for nodular cast iron production.

In order to achieve the above purpose, the present invention provides the following technical solutions: the casting device for spheroidal graphite cast iron production comprises a base, a heat preservation furnace, a liquid discharge groove, a pipe die, a sliding table, a forming mechanism, an audible and visual alarm and a quality monitoring mechanism, wherein the left end of the upper surface of the base is fixedly connected with the bottom of the heat preservation furnace, the heat preservation furnace keeps spheroidal graphite cast iron liquid warm, the left end of the liquid discharge groove is fixedly connected with the bottom end of the right side wall of the heat preservation furnace, the liquid discharge groove is used for guiding spheroidal graphite cast iron liquid, and the sliding table is fixedly connected to the right side of the upper surface of the base; the forming mechanism is fixedly connected to the top of the sliding table, the forming mechanism moves left and right through the sliding table, and the pipe die is arranged in the inner cavity of the forming mechanism; the audible and visual alarm is arranged on the upper surface of the forming mechanism; the number of the quality monitoring mechanisms is two, and the quality monitoring mechanisms are respectively arranged at the left end and the right end inside the forming mechanism;

the forming mechanism comprises an outer cylinder, a driving assembly, a rotary drum, an outer toothed ring, a clamping plate, a guide rod, a rotary ring, a guide groove and a hydraulic cylinder, wherein the outer cylinder is fixedly connected to the top of the sliding table; the driving component is arranged at the bottom end of the right side wall of the outer cylinder; the rotary drum is rotatably arranged in the middle of the inner cavity of the outer cylinder along the left-right direction through a support; the outer gear ring is arranged at the right end of the outer wall of the rotary drum, and the rotary drum is rotated by stirring the outer gear ring through the driving assembly; the clamping plates are arranged at the left side and the right side of the outer wall of the rotary drum in an equidistant manner along the circumferential direction, the clamping plates clamp and position the pipe die, the pipe die of the clamping plates is provided with anti-slip edges, the friction force between the clamping plates and the pipe die is increased, and the fixing is more stable; the guide rod is transversely arranged on the inner side of the clamping plate, the guide rod is cylindrical, and the guide rod slides smoothly in the guide groove by utilizing the curved surface of the guide rod; the number of the swivel rings is two, the swivel rings are respectively rotatably arranged at the left side and the right side of the outer wall of the rotary drum, a plurality of guide grooves are formed in the outer wall of the swivel rings along the circumferential direction, and the guide rods are inserted into the inner cavities of the guide grooves; one end of the hydraulic cylinder is connected with the bottom end of the inner wall of the outer cylinder through a pin shaft, and the other end of the hydraulic cylinder is connected with the outer wall of the swivel through a pin shaft;

the quality monitoring mechanism comprises a sensing component and an amplifying component, wherein the sensing component is arranged at the bottom end of the inner wall of the outer cylinder, and the amplifying component is arranged at the rear side of the sensing component.

Preferably, the guide grooves are arc-shaped and are distributed on the outer wall of the swivel at equal intervals clockwise.

Preferably, the driving assembly comprises a motor and a first gear, the motor is installed at the bottom end of the right side wall of the outer cylinder, the first gear is installed at the output end of the motor, and the rotating cylinder can be rotated through meshed connection of the first gear and the outer gear ring under the driving of the motor.

Preferably, the purpose is to sense the eccentric state of the rotary drum through mechanical movement, the sensing assembly comprises a first box body, a limit column, a spring, a rack and a roller, and the first box body is arranged at the bottom end of the inner wall of the outer drum; the limiting column and the spring are inserted into the inner cavity of the first box body from top to bottom; the rack is embedded at the rear side of the limit post; the roller can be installed in the rolling limit post top, promotes limit post upward movement under the spring force effect, lets the roller and rotary drum outer wall contact.

Preferably, the cross section of the limiting post is rectangular.

Preferably, the linear motion of the limit column is converted into the axial motion of the swing rod, the eccentric rotation of the pipe die is monitored, and further the molding quality of the nodular cast iron pipe is monitored, the amplifying assembly comprises a second box body, a travel switch, a rotating shaft, the swing rod, a second gear, an electric telescopic rod and a stop block, and the second box body is arranged at the rear side of the first box body; the number of the travel switches is two, and the travel switches are respectively arranged at the rear ends of the upper inner wall and the lower inner wall of the second box body and are electrically connected with the audible and visual alarm; the rotating shaft can rotate around the axis of the rotating shaft through a bearing and is arranged at the front end of the inner cavity of the second box body; the swing rod and the second gear are respectively arranged at the left side and the right side of the outer wall of the rotating shaft, and the second gear is in meshed connection with the rack; the electric telescopic rod is arranged in the middle of the right side wall of the second box body, and the travel switch is electrically connected with the electric telescopic rod; the dog is installed the electric telescopic handle output.

Preferably, the swing rod and the travel switch are in the same plane.

The casting method of the casting device for producing the spheroidal graphite cast iron comprises the following steps:

step one, enabling an outer cylinder to move left and right through a sliding table, enabling a first gear to rotate under the drive of a motor, enabling a rotary drum to rotate through the transmission of the first gear and an outer tooth ring, enabling a pipe die to rotate, putting spheroidal graphite cast iron liquid into a heat preservation furnace, enabling spheroidal graphite cast iron liquid to flow out of the right side of a liquid discharge groove and drop on the inner wall of the pipe die, enabling the spheroidal graphite cast iron liquid to be evenly paved on the inner wall of the pipe die through centrifugal force along with the rotation of the pipe die, and cooling to obtain a spheroidal graphite cast iron pipe;

when the pipe die needs to be replaced, the rotating ring is driven to rotate anticlockwise through the hydraulic oil cylinder, the curved surface at the inner side of the guide groove extrudes the guide rod outwards, the clamping plate is pulled to move outwards, the pipe die is loosened by the clamping plate, the pipe die can be pulled out of the rotary drum, after the pipe die is replaced, the rotating ring is driven to rotate clockwise through the hydraulic oil cylinder, the curved surface at the outer side of the guide groove moves inwards by extruding the guide rod, the clamping plate clamps the pipe die, centering fixation of the pipe die is achieved, and replacement of the pipe die is completed;

step three, when the molding quality of the nodular cast iron pipe needs to be monitored, the roller is always in contact with the outer wall of the rotary drum under the action of spring force, the roller rolls along with the rotation of the rotary drum, friction force between the roller and the rotary drum is reduced, the eccentricity is gradually increased when the rotary drum rotates along with the increase of the mechanical wear time of the rotary drum, the roller is extruded when the rotary drum eccentrically rotates, the limit post is driven to move up and down, the swing rod swings downwards or upwards under the meshing transmission of the rack and the second gear, when the swing rod triggers the travel switch, the electric telescopic rod drives the stop block to move leftwards, the stop block limits the swing rod, the swing rod always triggers the travel switch, and therefore the audible-visual alarm continuously sounds and emits light, and the rotary drum of a worker is reminded to rotate beyond the molding standard of the nodular cast iron pipe.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, the rotating ring can be driven to rotate clockwise or anticlockwise through the hydraulic oil cylinder, so that the guide groove is inwards or outwards extruded to the guide rod, the clamping plate can be inwards or outwards moved, and the clamping plate can be close to or far away from the pipe die, thereby achieving the centering and clamping purposes of the pipe die, saving time and labor in pipe die replacement, and further improving the production efficiency of the nodular cast iron pipe;

2. according to the invention, the roller can be always attached to the rotary drum through the elastic force of the spring, the limit column can be displaced up and down along with the increase of the eccentricity of the rotary drum, the swing rod can move downwards or upwards under the transmission of the rack and the second gear, when the swing rod triggers the travel switch, the electric telescopic rod drives the stop block to move left to limit the swing rod, the audible and visual alarm continuously alarms, the centrifugal casting monitoring of the pipe die is realized, the quality monitoring purpose of the nodular cast iron pipe is further achieved, and the yield is improved.

Drawings

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

FIG. 2 is a front cross-sectional view of the forming mechanism of the present invention;

FIG. 3 is a left side cross-sectional view of the present invention;

FIG. 4 is a schematic diagram of a driving assembly according to the present invention;

FIG. 5 is a left side view of the quality monitoring mechanism of the present invention;

fig. 6 is a top cross-sectional view of an enlarged assembly of the present invention.

In the figure: 1. a base; 2. a holding furnace; 3. a liquid discharge tank; 4. a pipe die; 5. a sliding table; 6. a forming mechanism; 7. an audible and visual alarm; 8. a quality monitoring mechanism; 61. an outer cylinder; 62. a drive assembly; 63. a rotating drum; 64. an outer toothed ring; 65. a clamping plate; 66. a guide rod; 67. a swivel; 68. a guide groove; 69. a hydraulic cylinder; 621. a motor; 622. a first gear; 81. a sensing component; 82. an amplifying assembly; 811. a first case; 812. a limit column; 813. a spring; 814. a rack; 815. a roller; 821. a second case; 822. a travel switch; 823. a rotating shaft; 824. swing rod; 825. a second gear; 826. an electric telescopic rod; 827. and a stop block.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a technical scheme that: 1-6, including base 1, the left end fixedly connected with holding furnace 2 of the upper surface of base 1, holding furnace 2 can keep warm to the spheroidal graphite cast iron liquid, guarantee its mobility, the right sidewall bottom of holding furnace 2 installs the drain groove 3 along the left and right direction, drain groove 3 realize draining to spheroidal graphite cast iron liquid, the right end fixedly connected with slip table 5 of the upper surface of base 1, the top fixedly connected with forming mechanism 6 of slip table 5, the middle part of forming mechanism 6 inner chamber holds tube die 4, spheroidal graphite cast iron liquid is laid on the inner wall of tube die 4, make spheroidal graphite cast iron liquid form the spheroidal graphite cast iron pipe, the upper surface of forming mechanism 6 installs the audible and visual annunciator 7, come to report to the police through audible and visual annunciator 7, play and point out the problem that the tube die 4 rotates and appear the deviation, the quality monitoring mechanism 8 is installed on both sides of forming mechanism 6 inner chamber;

the slip table 5 includes the frame of fixed connection on base 1 upper surface right side, and both sides all are provided with the slide rail around the frame top, and the slide rail outer wall has cup jointed and has been slided the slide about can, and the frame right side is provided with step motor, and the screw rod is installed to the step motor output, drives the screw rod rotatory through step motor, and screw rod screw thread rotation power can drive the slide and move about on the slide rail.

As a preferred scheme, the forming mechanism 6 comprises an outer cylinder 61 fixedly connected to the upper surface of the sliding seat, a driving assembly 62 is installed at the bottom end of the right side wall of the outer cylinder 61, a rotatable rotary cylinder 63 is installed in an inner cavity of the outer cylinder 61 through a bearing, an outer toothed ring 64 is installed at the right end of the outer wall of the rotary cylinder 63, the rotary cylinder 63 can be rotated by stirring the outer toothed ring 64 through the driving assembly 61, a plurality of clamping plates 65 are inserted at the left side and the right side of the outer wall of the rotary cylinder 63 at equal intervals along the circumferential direction, the pipe die 4 is clamped by the plurality of clamping plates 65 from a plurality of directions, centering fixation of the pipe die 4 is realized, a guide rod 66 is installed at the inner side of the clamping plates 65, a rotatable swivel 67 is installed at the left side and the right side of the outer wall of the rotary cylinder 63, guide grooves 68 are arc-shaped, a plurality of guide grooves 68 are distributed on the outer wall of the swivel 67 along the circumferential direction at equal intervals, when the swivel 67 rotates clockwise, the curved surface of the inner wall of the guide grooves 68 can press the guide rod 66 inwards or outwards, and further the clamping plates 65 are enabled to move inwards or outwards through the clockwise rotation of the guide rod 69, one end of a hydraulic cylinder 69 is connected to the bottom end of the inner cavity of the outer cylinder through a pin roll 69, and the outer wall of the hydraulic cylinder 69 is connected with the swivel 67 through the pin shaft 69;

the spheroidal graphite cast iron pipe forming mode comprises the following steps: the outer cylinder 61 can be moved left and right through the sliding table 5, the motor 621 drives the first gear 622 to rotate, the rotary drum 63 can be rotated under the transmission of the first gear 622 and the outer toothed ring 64, spheroidal graphite cast iron liquid is put into the holding furnace 2, the spheroidal graphite cast iron liquid falls on the inner wall of the pipe die 4 under the drainage of the liquid discharge groove 3, the spheroidal graphite cast iron liquid can be uniformly paved on the inner wall of the pipe die 4 along with the rotation of the pipe die 4 by centrifugal force, and the spheroidal graphite cast iron pipe is obtained after cooling;

tube die 4 replacement mode: the rotating ring 67 is driven to rotate clockwise or anticlockwise through the hydraulic oil cylinder 69, the curved surface of the guide groove 68 can extrude the guide rod 66 to move inwards or outwards, the clamping plate 65 is pulled to move inwards or outwards, the clamping plate 65 is close to or far away from the pipe die 4, the pipe die 4 can be taken and placed in the rotating cylinder 63, centering fixation of the pipe die 4 is achieved, and the purpose of replacing the pipe die 4 is achieved.

Preferably, the driving assembly 62 further comprises a motor 621 mounted at the bottom end of the right side wall of the outer cylinder 61, a first gear 622 meshed with the outer gear ring 64 is mounted at the output end of the motor 621, and the rotating cylinder 63 can be rotated by driving the motor 621 through the first gear 622 and the outer gear ring 64.

As a preferred scheme, the quality monitoring mechanism 8 comprises a sensing component 81 and an amplifying component 82, wherein the sensing component 81 is arranged at the bottom end of the inner wall of the outer cylinder 61, and the rear side of the sensing component 81 is arranged at the front end of the amplifying component 82;

the perception subassembly 81 is including installing the first box body 811 in urceolus 61 inner wall bottom, and first box body 811 inner chamber has pegged graft respectively spacing post 812 and spring 813 from last to lower, and spacing post 812 cross sectional shape is the rectangle, prevents that spacing post 812 from appearing rotating, and the rack 814 has been inlayed along upper and lower direction to spacing post 812 rear side, and the gyro wheel 815 that can roll is installed at spacing post 812 top, promotes spacing post 812 upward movement under the effect of spring 813 elasticity, aim at let gyro wheel 815 can contact with pipe die 4 outer wall all the time.

As a preferred solution, the amplifying assembly 82 includes a second box body 821 installed at the rear side of the first box body 811, the rear ends of the upper and lower inner walls of the second box body 821 are both installed with a travel switch 822, the travel switch 822 is electrically connected with the audible and visual alarm 7, the front side of the inner cavity of the second box body 821 is installed with a rotating shaft 823 capable of rotating around the axis thereof through a bearing, the left and right sides of the outer wall of the rotating shaft 823 are respectively installed with a swinging rod 824 and a second gear 825, the second gear 825 is meshed with a rack 814, the swinging rod 824 and the travel switch 822 are located in the same plane, so that the swinging rod 824 can touch the travel switch 822 when swinging up and down, and can make the second gear 825 drive the swinging rod 824 to swing down or up along with the up and down movement of the rack 814 along with the limit column 812, an electric telescopic rod 826 is installed at the middle part of the rear side wall of the second box body 821, a stop 827 is installed at the output end of the electric telescopic rod 826, the stop 827 is pushed by the electric telescopic rod 826, the stop 827 moves the swinging rod 824 contacted with the travel switch 822, so that the switch 822 keeps a trigger state;

the ductile cast iron pipe molding quality monitoring method comprises the following steps: the roller 815 can always be in contact with the outer wall of the rotary drum 63 through the elasticity of the spring 813, the friction force between the roller 815 and the rotary drum 63 can be reduced due to the rolling of the roller 815, along with the increase of the mechanical wear time of the rotary drum 63, the eccentricity of the rotary drum 63 is gradually increased, the roller 815 is extruded when the rotary drum 63 eccentrically rotates, the limiting post 812 is driven to move up and down, the swing rod 824 swings downwards or upwards under the meshing transmission of the rack 814 and the second gear 825, when the swing rod 824 triggers the travel switch 822, the electric telescopic rod 826 drives the stop block 827 to move leftwards, the stop block 827 limits the swing rod 824, and the swing rod 824 always triggers the travel switch 822, so that the audible-visual alarm 7 continuously sounds and emits light, and the rotary drum 63 is reminded to rotate beyond the molding standard of the spheroidal graphite cast iron pipe.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (8)

1. The utility model provides a casting device is used in nodular cast iron production, includes base (1), holding furnace (2), flowing back groove (3) and pipe die (4), base (1) upper surface left end and holding furnace (2) bottom fixed connection, holding furnace (2) let nodular cast iron liquid obtain the heat preservation, flowing back groove (3) left end and holding furnace (2) right side wall bottom fixed connection, flowing back groove (3) carry out nodular cast iron liquid drainage, a serial communication port, casting device is used in nodular cast iron production still includes:

the sliding table (5) is fixedly connected to the right side of the upper surface of the base (1);

the forming mechanism (6) is fixedly connected to the top of the sliding table (5), the forming mechanism (6) is moved left and right through the sliding table (5), and the pipe die (4) is arranged in the inner cavity of the forming mechanism (6);

an audible and visual alarm (7) which is arranged on the upper surface of the forming mechanism (6);

the quality monitoring mechanisms (8) are two in number and are respectively arranged at the left end and the right end inside the forming mechanism (6);

the molding mechanism (6) comprises:

an outer cylinder (61) fixedly connected to the top of the sliding table (5);

the driving assembly (62) is arranged at the bottom end of the right side wall of the outer cylinder (61);

a rotary drum (63) rotatably mounted in the middle of the inner cavity of the outer cylinder (61) in the left-right direction through a support;

the outer toothed ring (64) is arranged at the right end of the outer wall of the rotary drum (63), and the rotary drum (63) is rotated by stirring the outer toothed ring (64) through the driving assembly (62);

the clamping plates (65) are in number and are inserted at the left side and the right side of the outer wall of the rotary drum (63) at equal intervals along the circumferential direction, and the clamping plates (65) clamp and position the pipe die (4);

the guide rod (66) is transversely arranged on the inner side of the clamping plate (65);

the number of the swivel rings (67) is two, the swivel rings are respectively rotatably arranged at the left side and the right side of the outer wall of the rotary drum (63), a plurality of guide grooves (68) are formed in the outer wall of the swivel rings (67) along the circumferential direction, and the guide rods (66) are inserted into the inner cavities of the guide grooves (68);

one end of the hydraulic cylinder (69) is connected with the bottom end of the inner wall of the outer cylinder (61) through a pin shaft, and the other end of the hydraulic cylinder is connected with the outer wall of the swivel (67) through a pin shaft;

the quality monitoring mechanism (8) comprises a sensing assembly (81) and an amplifying assembly (82), wherein the sensing assembly (81) is arranged at the bottom end of the inner wall of the outer cylinder (61), and the amplifying assembly (82) is arranged at the rear side of the sensing assembly (81).

2. Casting device for ductile iron production according to claim 1, characterized in that several guide grooves (68) are arc-shaped and are equally distributed on the outer wall of the swivel (67) clockwise.

3. The casting device for ductile iron production according to claim 2, wherein the driving assembly (62) comprises a motor (621) and a first gear (622), the motor (621) is installed at the bottom end of the right side wall of the outer cylinder (61), the first gear (622) is installed at the output end of the motor (621), and the rotating cylinder (63) can be rotated by the meshed connection of the first gear (622) and the outer gear ring (64) under the driving of the motor (621).

4. A casting device for ductile iron production according to claim 3 characterized in that said sensing assembly (81) comprises:

a first box (811) mounted at the bottom end of the inner wall of the outer cylinder (61);

the limiting column (812) and the spring (813) are inserted into the inner cavity of the first box body (811) from top to bottom;

the rack (814) is embedded at the rear side of the limit column (812);

the roller (815) is arranged at the top end of the limiting column (812) in a rolling way, and pushes the limiting column (812) to move upwards under the action of the elasticity of the spring (813), so that the roller (815) is contacted with the outer wall of the rotary drum (63).

5. The casting device for ductile iron production according to claim 4 wherein the limiting post (812) has a rectangular cross-sectional shape.

6. The casting device for ductile iron production according to claim 5 wherein said amplifying assembly (82) comprises:

a second case (821) mounted on the rear side of the first case (811);

the number of the travel switches (822) is two, the travel switches (822) are respectively arranged at the rear ends of the upper inner wall and the lower inner wall of the second box body (821), and the travel switches (822) are electrically connected with the audible and visual alarm (7);

the rotating shaft (823) is rotatably arranged at the front end of the inner cavity of the second box body (821) around the axis of the rotating shaft through a bearing;

the swing rod (824) and the second gear (825) are respectively arranged at the left side and the right side of the outer wall of the rotating shaft (823), and the second gear (825) is in meshed connection with the rack (814);

the electric telescopic rod (826) is arranged in the middle of the right side wall of the second box body (821), and the travel switch (822) is electrically connected with the electric telescopic rod (826);

and the stop block (827) is arranged at the output end of the electric telescopic rod (826).

7. The casting device for ductile iron production according to claim 6 wherein said swing link (824) is in the same plane as the travel switch (822).

8. The casting method of a casting device for ductile iron production according to claim 7 comprising the steps of:

step one, the outer cylinder (61) can be moved left and right through the sliding table (5), the first gear (622) is driven by the motor (621) to rotate, the rotary drum (63) can be rotated through the transmission of the first gear (622) and the outer tooth ring (64), the pipe die (4) is enabled to rotate, the spheroidal graphite cast iron liquid is put into the heat preservation furnace (2), the spheroidal graphite cast iron liquid drops on the inner wall of the pipe die (4) along the right side of the liquid discharge groove (3), and the spheroidal graphite cast iron liquid can be uniformly paved on the inner wall of the pipe die (4) by centrifugal force along with the rotation of the pipe die (4), and the spheroidal graphite cast iron pipe is obtained after cooling;

when the pipe die (4) needs to be replaced, the rotating ring (67) is driven to rotate anticlockwise through the hydraulic cylinder (69), the guide rod (66) is extruded outwards by the inner side curved surface of the guide groove (68), the clamping plate (65) is pulled to move outwards, the clamping plate (65) releases the pipe die (4), the pipe die (4) can be pulled out of the rotary cylinder (63), after the pipe die (4) is replaced, the rotating ring (67) is driven to rotate clockwise through the hydraulic cylinder (69), the clamping plate (65) moves inwards by extruding the guide rod (66) by the outer side curved surface of the guide groove (68), the clamping plate (65) clamps the pipe die (4), centering fixation of the pipe die (4) is achieved, and replacement of the pipe die (4) is completed;

step three, when the quality of the nodular cast iron pipe is required to be monitored, the roller (815) is always contacted with the outer wall of the rotary drum (63) under the action of the elasticity of the spring (813), the roller (815) rolls along with the rotation of the rotary drum (63), the friction force between the roller (815) and the rotary drum (63) is reduced, the eccentricity is gradually increased along with the increase of the mechanical wear time of the rotary drum (63), the roller (815) is extruded when the rotary drum (63) eccentrically rotates, the limiting post (812) is driven to move up and down, the swing rod (824) swings downwards or upwards under the meshing transmission of the rack (814) and the second gear (825), when the swing rod (824) triggers the travel switch (822), the electric telescopic rod (826) drives the stop block (827) to move leftwards, the stop block (827) always triggers the travel switch (822), so that the audible and visual alarm (7) continuously sounds and emits light, and the rotary drum (63) is reminded to rotate beyond the nodular cast iron pipe molding standard.