A coated sand shell type iron sand negative pressure casting equipment and manufacturing process thereof

Abstract

The present invention relates to the technical field of coated sand shell type iron sand negative pressure casting, specifically to a coated sand shell type iron sand negative pressure casting equipment and manufacturing process, including a box, an air chamber, a filter, an exhaust pipe and a negative pressure device, wherein: the box is symmetrically provided with air chambers on both sides, and the two air chambers are both equipped with a filter connected to the inside of the box to prevent the molding sand from entering the air chamber, and the two air chambers are both equipped with an exhaust pipe and connected to the negative pressure device, and the two exhaust pipes are both equipped with a detection device for detecting the air pressure of the air chamber. The present invention detects the air pressure of the air chamber through a detection device to determine whether the filter is blocked. When the filter is blocked, the drive device can be used to rotate the filter to move the filter away from the blocked position, thereby solving the problem that the filter used to isolate the sand and the negative pressure device is easily blocked by fine sand, making the negative pressure exhaust unobstructed, reducing the occurrence of undesirable phenomena such as pores, and improving the quality of castings.

Description

Technical Field

[0001] The invention relates to the technical field of coated sand shell type iron sand negative pressure casting, in particular to coated sand shell type iron sand negative pressure casting equipment and a manufacturing process. Background Art

[0002] Casting is the process of melting metal into a liquid that meets certain requirements and pouring it into a mold, and then cooling, solidifying, and cleaning it to obtain a casting with a predetermined shape, size, and performance.

[0003] With the vigorous development of the domestic machinery equipment manufacturing industry, the demand for high-precision castings is increasing. Traditional sand casting has become increasingly difficult to meet today's production needs due to its poor surface finish, low strength and dimensional accuracy. The advantages of coated sand casting technology and negative pressure casting have begun to emerge. The coated sand casting has a clear outline and a smooth appearance, and can manufacture complex castings, but coated sand casting releases waste gas during pouring. The negative pressure casting metal liquid has good fluidity and can cast thinner thin-walled parts, but its production process is not easy to produce complex castings. The coated sand mold can be placed in the sand box and buried with sand. An air isolation layer is set at the mouth of the sand box. The pouring port of the coated sand mold passes through the air isolation layer and is exposed above it. The metal liquid is poured, and the inside of the sand box is vacuumed under negative pressure. The combination of coated sand and negative pressure casting can greatly reduce or even avoid the harm of pouring waste gas to surrounding personnel and improve the quality of castings. However, when the sand box is vacuumed under negative pressure, the filter used to isolate the sand and the negative pressure device is easily clogged by fine sand. It is also easily clogged by condensed volatiles and dust from the coated sand after long-term use. This affects the discharge of gas in the sand box, the flow of molten metal, and causes adverse phenomena such as air holes, which reduces the quality of the casting or even makes it scrapped.

[0004] To this end, a coated sand shell type iron sand negative pressure casting equipment and a manufacturing process are proposed to reduce the clogging of the filter used to isolate the sand and the negative pressure device and improve the casting yield. Summary of the invention

[0005] The purpose of the present invention is to provide a coated sand shell type iron sand negative pressure casting equipment and manufacturing process, which detects the air pressure in the air chamber through a detection device to determine whether the filter is blocked. When the filter is blocked, the drive device can be used to rotate the filter to move it away from the blocked position, so that the negative pressure air can be pumped smoothly, reduce the occurrence of undesirable phenomena such as air holes, and improve the quality of the casting, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A coated sand shell type iron sand negative pressure casting equipment and manufacturing process, including a box body, an air chamber, a filter, an exhaust pipe and a negative pressure device, wherein: the box body is symmetrically provided with air chambers on both sides, the two air chambers should have sufficient space for installing a driving device, the two air chambers are both equipped with exhaust pipes, and the exhaust pipes are movably connected with a negative pressure device, the wall thickness of the exhaust pipe is 10mm to meet the working requirements of the negative pressure device, the two air chambers are rotatably installed with a filter screen connected to the inside of the box body, the filter screen can isolate sand from the negative pressure device, and when exhausting, the sand and dust entering the negative pressure device are minimized to ensure the stable operation of the negative pressure device.

[0008] A protective device, wherein the two air chambers are provided with a protective device for preventing the filter from deforming;

[0009] A detection device, wherein the two exhaust pipes are connected with a detection device for detecting whether the filter screen is blocked;

[0010] A driving device is connected to the two filter screens to drive the filter screens to rotate slowly and reduce the clogging of the filter screens.

[0011] Preferably, the protective device comprises a porous air filter plate rotatably mounted on the inner wall of the box body, the porous air filter plate is evenly provided with air pores for filtering air, the diameter of which is 20 mm, a filter screen pressure ring is installed on one side of the porous air filter plate, the filter screen is clamped and fixed between the porous air filter plate and the filter screen pressure ring, the porous air filter plate and the filter screen pressure ring are made of wear-resistant and non-deformable metal materials, such as high manganese steel and other materials, to avoid deformation of the filter screen pressure ring resulting in the inability to fix the filter screen, the filter screen is a two-layer 100-mesh stainless steel mesh to prevent fine sand from entering the negative pressure device, and The filter screen is coated with a wear-resistant coating to slow down the wear rate. The porous air filter plate is fixed with an air pipe by welding. The box body is provided with a mounting groove for mounting the porous air filter plate, the filter screen and the filter screen pressure ring. The mounting groove is circular and made of wear-resistant metal material to slow down the wear of the mounting groove during the movement of the filter screen. The mounting groove is movably installed with a mounting ring through a thread. The porous air filter plate, the filter screen and the filter screen pressure ring are placed in the mounting groove and connected by threads to facilitate the replacement of the filter screen. The mounting ring is also made of wear-resistant metal material to reduce wear.

[0012] Preferably, the exhaust pipe is fixedly installed on the outside of the box body by welding, and the exhaust pipe is connected to the air chamber through through hole 1, the inner diameter of the exhaust pipe is consistent with the diameter of through hole 1, so as to ensure smooth negative pressure exhaust, the exhaust pipe is connected with a negative pressure device, the detection device comprises a cylinder fixedly installed on the exhaust pipe by welding, and the exhaust pipe and the cylinder are connected through through hole 2, and the air tightness of the exhaust pipe and the cylinder must be ensured during welding to keep the air pressure stable, a piston is movably installed in the cylinder, a spring connected to the top wall of the piston is fixedly installed on the inner top wall of the cylinder, a piston rod is fixedly installed on the top wall of the piston, and the top end of the piston rod extends to the upper side of the cylinder, a trigger pressure block is fixedly installed on the top wall of the piston rod by welding, and a key switch matching the trigger pressure block is fixedly installed on the outer top wall of the cylinder. And it is electrically connected to the servo motor, the spring is sleeved on the outside of the piston rod in the cylinder, and when the trigger pressure block and the key switch are at the set pressure in the air chamber and the exhaust pipe or the negative pressure device is not working, the pressure difference between the air chamber and the outside of the box is insufficient to touch the trigger pressure block and the key switch, and the key switch will not be triggered. When the pressure in the air chamber and the exhaust pipe is less than the set pressure, the connecting rod of the piston drives the trigger pressure block to move downward under the action of the pressure difference between the air chamber and the outside of the box, and presses the key switch installed on the top wall outside the trigger cylinder, starting the driving device where the servo motor is located, driving the filter to slowly rotate the set angle, when the filter leaves the blocked position and the negative pressure exhaust is unblocked, the air pressure in the air chamber and the exhaust pipe rises, the pressure difference is reduced, the trigger pressure block is separated from the key switch, the driving device stops moving, and the filter stops in a suitable position.

[0013] Preferably, a buzzer alarm is installed on the top of the trigger pressure block through a thread, and the buzzer alarm is electrically connected to the push button switch. When the driving device drives the filter to slowly rotate the set angle, the pressure difference between the air chamber and the outside of the box does not reach the set pressure difference, and the driving device continues to drive the filter to slowly rotate the set angle. When the set pressure difference is not reached after one rotation, the buzzer alarm sends out an alarm signal, which means that the filter is blocked by condensed coated sand volatiles and dust and other substances, and the filter needs to be replaced or cleaned in time to avoid affecting the quality of subsequent castings.

[0014] Preferably, a motor seat is installed in the air chamber by welding, and a reinforcing plate is provided under the motor seat to improve the stability of the motor seat, the servo motor is installed on the motor seat by threads, a driving gear is installed on the output shaft of the servo motor by a flat key, and a driven gear meshing with the driving gear is installed on the air pipe by a flat key, the servo motor, the meshing driving gear, and the driven gear constitute a driving device for driving the filter to rotate slowly, when there is too much sand blocking the filter at the position where the filter is located, the filter is moved away from the blocked position by rotation, so that negative pressure suction can be carried out smoothly, and the protective device composed of the porous air filter plate, the filter pressure ring, and the filter are all circular, so that the filter can rotate under the action of the driving device.

[0015] Preferably, a dust cover is installed outside the driving gear and the driven gear, and the dust cover includes two half shells symmetrically arranged, and a rotating shaft is fixedly installed on the box body by welding. The two half shells are rotatably installed on the rotating shaft and are used to wrap the driving gear and the driven gear. The two half shells are jointly provided with a through hole three that cooperates with the air pipe, and the two half shells are jointly provided with a through hole four that cooperates with the output shaft of the servo motor. The bottom ends of the two half shells are fixedly provided with connecting blocks by welding, and the two connecting blocks are fixedly connected by connecting screws. A limiting column located in the middle of the two connecting blocks is fixedly installed on the box body by welding. When the two parts of the dust cover are combined to wrap the driving gear and the driven gear, the connecting blocks at the bottom of the two half shells can be fixed by connecting screws to fix the dust cover and facilitate the removal of the dust cover. The dust cover effectively prevents dust from entering, which causes aggravated wear of the gears.

[0016] Preferably, the detection device is an air pressure detection device that can accurately display the air pressure, which can accurately reflect the changes in the air pressure in the air chamber and is used to study the air pressure suitable for casting production.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention automatically detects whether the filter is blocked by a detection device, and uses a driving device to rotate the filter to move it away from the blocked position, so that negative pressure exhaust can be carried out smoothly. Compared with the existing negative pressure casting, when too much sand blocks the filter, the set negative pressure in the box cannot be reached. The present invention can effectively reduce the situation of sand blocking the filter, maintain the set negative pressure in the box, maintain the quality of the casting, and improve the molding rate of the casting.

[0019] 2. The present invention ensures that the filter is in a position where negative pressure exhaust is unobstructed through automatic detection by the detection device and the action of the driving device, so that the box is maintained at a set negative pressure. During casting, the waste gas generated during pouring can be continuously extracted from the box, reducing the direct discharge of waste gas into the workshop.

[0020] 3. When the filter is clogged by the condensed volatiles and dust of the coated sand, the clogging problem cannot be solved by rotating the filter. The detection device can determine through air pressure whether the filter is clogged by the condensed volatiles and dust of the coated sand, and send out an alarm signal in time to remind the operator to replace the filter in time, thus solving the trouble of the operator entering the box to observe whether the filter is clogged, and facilitating production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a driving device according to Embodiment 1 of the present invention;

[0023] Figure 3 for Figure 2 A partial enlarged view of part A;

[0024] Figure 4 This is a schematic diagram of the structure of a protective device according to Embodiment 1 of the present invention;

[0025] Figure 5 for Figure 4 A partial enlarged view of part B;

[0026] Figure 6 This is a schematic diagram of a driving device according to a second embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of a protective device according to a second embodiment of the present invention;

[0028] Figure 8 for Figure 7 A partial enlarged view of part C in the middle;

[0029] Fig. 9 This is the manufacturing process of the present invention.

[0030] In the figure: 1. Box body; 2. Air chamber; 3. Filter; 4. Exhaust pipe; 5. Porous filter plate; 6. Filter pressure ring; 7. Air pipe; 8. Mounting groove; 9. Mounting ring; 10. Motor seat; 11. Servo motor; 12. Driving gear; 13. Driven gear; 14. Dust cover; 15. Rotating shaft; 16. Connecting block; 17. Limiting column; 18. Cylinder; 19. Piston; 20. Spring; 21. Trigger pressure block; 22. Push switch; 23. Buzzer alarm; 24. Air pressure detection equipment; 25. Piston rod. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] For example, see Figures 1 to 4 The present invention provides a coated sand shell type iron sand negative pressure casting equipment and manufacturing process, and the technical scheme is as follows:

[0033] A coated sand shell type iron sand negative pressure casting equipment and manufacturing process, including: a box body 1, an air chamber 2, a filter screen 3, an exhaust pipe 4 and a negative pressure device, wherein the air chamber 2 negative pressure device is symmetrically arranged on both sides of the box body 1, the air chamber 2 should be provided with sufficient space for installing a driving device, an exhaust pipe 4 is installed on the air chamber 2, and the exhaust pipe 4 is movably connected to the negative pressure device, and the wall thickness of the exhaust pipe 4 is 10mm to meet the working requirements of the negative pressure device, and the air chamber 2 is rotatably installed with a filter screen 3 connected to the inside of the box body 1, and the filter screen 3 can isolate the sand from the negative pressure device. When the air is exhausted, the sand and dust entering the negative pressure device are reduced as much as possible to ensure the stable operation of the negative pressure device. A driving device for driving the filter screen 3 to rotate slowly is installed on the air chamber 2, and a detection device for detecting the air pressure of the air chamber 2 is installed on the exhaust pipe 4.

[0034] The protective device includes a porous air filter plate 5 rotatably mounted on the inner wall of the box body 1, and the porous air filter plate 5 is evenly provided with air pores for filtering air, and the diameter of the air pores is 20 mm. A filter screen pressing ring 6 is installed on one side of the porous air filter plate 5, and the filter screen 3 is clamped between the porous air filter plate 5 and the filter screen pressing ring 6. The porous air filter plate 5 and the filter screen pressing ring 6 are made of wear-resistant and non-deformable metal materials to avoid deformation of the porous air filter plate 5 and the filter screen pressing ring 6, which may make it impossible to fix the filter screen 3. The filter screen 3 is a two-layer 100-mesh stainless steel mesh, and an air pipe 7 is fixedly installed on the porous air filter plate 5 by welding.

[0035] A motor base 10 is installed in the air chamber 2 by welding, and a reinforcing plate is provided under the motor base 10 to improve the stability of the motor base 10. A servo motor 11 is installed on the motor base 10 by threads, and a driving gear 12 is installed on the output shaft of the servo motor 11 through a flat key. A driven gear 13 meshing with the driving gear 12 is installed on the air pipe 7 through a flat key. The driving gear 12, the servo motor 11, and the driven gear 13 drive the filter screen 3 to rotate slowly.

[0036] The exhaust pipe 4 is fixedly mounted on the outside of the box body 1 by welding, and the exhaust pipe 4 is connected to the air chamber 2 through the through hole 1, the inner diameter of the exhaust pipe 4 is consistent with the diameter of the through hole 1, the exhaust pipe 4 is connected with a negative pressure device, the detection device includes a cylinder 18 fixedly mounted on the exhaust pipe 4 by welding, and the exhaust pipe 4 is connected to the cylinder 18 through the through hole 2. During welding, the air tightness of the exhaust pipe 4 and the cylinder 18 must be ensured to keep the air pressure stable, a piston 19 is movably mounted in the cylinder 18, a spring 20 connected to the top wall of the piston 19 is fixedly mounted on the inner top wall of the cylinder 18, a piston rod 25 is fixedly mounted on the top wall of the piston 19, and the top end of the piston rod 25 extends to the upper side of the cylinder 18, a trigger pressure block 21 is fixedly mounted on the top end of the piston rod 25, a key switch 22 matching the trigger pressure block 21 is fixedly mounted on the top wall of the cylinder 18, and the key switch 22 is electrically connected to the buzzer alarm 23 and the servo motor 11.

[0037] The specific manufacturing process is as follows:

[0038] When preparing for pouring, use lifting equipment to place the sand box on a suitable workbench through the lifting ears outside the box body 1, place the processed coated sand mold shell in the box and bury the sand. When the wall thickness of the casting is uneven, iron sand can be placed at the wall thickness so that the casting can be cooled evenly and reduce deformation of the casting. When the cooling time of the casting needs to be accelerated, iron sand can also be placed outside the coated sand mold shell. After burying the sand, it needs to be vibrated to avoid poor sand filling. An air isolation layer is laid on the box body 1 to seal the box and the gate of the coated sand mold shell is passed through the air isolation layer to facilitate the subsequent pouring of the casting.

[0039] When pouring begins, turn on the negative pressure device for negative pressure extraction, and inject molten metal through the gate of the coated sand mold shell. The molten metal can accelerate the filling of the coated sand mold shell under the action of negative pressure to improve the molding effect. During pouring, the coated sand mold shell produces water vapor, resin, urotropine, calcium stearate, coal powder, starch and inoculant (tin) metal alloys, and ammonia, acetate, hydrogen sulfide, dimensionless and other volatile odors that undergo chemical reactions and decomposition at high temperatures of 1400℃-1500℃ can be extracted through the negative pressure device through the filter device to avoid defects such as pores in the casting and greatly reduce the direct emission of waste gas into the workshop to affect human health.

[0040] After pouring, the negative pressure device stops working. After cooling, the formed casting can be taken out and the iron sand can be screened out for reuse.

[0041] During pouring, when the position of the filter screen 3 is blocked, the set negative pressure in the box cannot be reached. The negative pressure device in the air chamber 2 continuously evacuates air due to the blockage of the filter screen 3, causing the air pressure to continue to drop. The pressure difference increases, triggering the detection device connected to the air chamber 2 through the exhaust pipe 4. The piston 19 on the detection device continues to drop under the action of the pressure difference, and the connecting rod on the piston 19 also continuously drops with the trigger pressure block 21. When it drops to contact the key switch 22 installed on the cylinder 18, it triggers the servo motor 11 connected to the key switch 22. The drive device where the servo motor 11 is located starts to start, and drives the filter screen 3 to slowly rotate the set angle through the gear to leave the blockage. position and make negative pressure exhaust unobstructed, the pressure difference between the air chamber 2 and the outside of the box body 1 reaches the set pressure difference, the piston 19 rises and triggers the pressure block 21 to separate from the key switch 22, the driving device stops working, and the filter screen 3 stops at a suitable position. If the set angle is rotated, the pressure difference between the air chamber 2 and the outside of the box body 1 does not reach the set pressure difference, the driving device continues to drive the filter screen 3 to slowly rotate the set angle. When the set pressure difference is not reached after one rotation, the buzzer alarm 23 connected to the key switch 22 sends an alarm signal, which means that the filter screen 3 is blocked by condensed coated sand volatiles and dust and other substances, and the filter screen 3 needs to be replaced or cleaned in time to avoid affecting the quality of subsequent castings.

[0042] For example 2, please refer to Figures 5 to 7 , including, 1, a box body; 2, an air chamber; 3, a filter; 4, an exhaust pipe; 5, a porous air filter plate; 6, a filter pressure ring; 7, an air pipe; 8, a mounting groove; 9, a mounting ring; 10, a motor seat; 11, a servo motor; 12, a driving gear; 13, a driven gear; 14, a dust cover; 15, a rotating shaft; 16, a connecting block; 17, a limiting column; 24, an air pressure detection device, which is different from the first embodiment in that: the detection device is replaced with an air pressure detection device 24 that can accurately display the air pressure, such as a negative pressure vacuum gauge YZ-60, which can accurately reflect the changes in the air pressure in the air chamber 2 and is used to study the air pressure suitable for casting production, but the temperature of the extracted gas is relatively high, and the material of the sensitive element of the air pressure detection device 24 is often deformed due to the increase in temperature, which affects the measurement result, so the extracted gas needs to be cooled.

[0043] Compared with Example 1, although the detection accuracy of Example 1 is slightly lower than that of Example 2, Example 1 has a lower production cost and a simpler structure. It is suitable for the best production air pressure of known castings and is used in batch production. In contrast, Example 2 is suitable for the first production of castings and studies the air pressure most suitable for casting production. It is easy to record by accurately displaying the air pressure value. In summary, the producer can choose according to different production situations.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coated sand shell type iron sand negative pressure casting device, comprising a box (1), an air chamber (2), a filter (3), an exhaust pipe (4) and a negative pressure device, wherein: Air chambers (2) are symmetrically arranged on both sides of the box body (1), and filters (3) communicating with the interior of the box body (1) are installed on the two air chambers (2). Air extraction pipes (4) are installed on the two air chambers (2), and a negative pressure device is commonly connected to the two air extraction pipes (4); the invention is characterized in that it also includes: A protective device, wherein the two air chambers (2) are both provided with a protective device for preventing the filter screen (3) from deforming; A detection device, wherein the two exhaust pipes (4) are both connected with a detection device for detecting whether the filter screen (3) is blocked; A driving device, wherein the two filter screens (3) are both connected to a driving device for driving the filter screens (3) to rotate and reduce clogging of the filter screens (3); The protective device comprises a porous air filter plate (5) rotatably mounted on the inner wall of the box body (1), a filter screen pressing ring (6) being fixedly mounted on one side of the porous air filter plate (5), and the filter screen (3) being clamped and fixed between the porous air filter plate (5) and the filter screen pressing ring (6), an air pipe (7) being fixedly mounted on the porous air filter plate (5), a mounting groove (8) for mounting the porous air filter plate (5), the filter screen (3) and the filter screen pressing ring (6) being provided on the box body (1), and a mounting ring (9) for fixing the porous air filter plate (5), the filter screen (3) and the filter screen pressing ring (6) in the mounting groove (8); The detection device comprises a cylinder (18) fixedly mounted on an exhaust pipe (4), and the exhaust pipe (4) is connected to the cylinder (18) through a second through hole, a piston (19) is movably mounted in the cylinder (18), a spring (20) connected to the top wall of the piston (19) is fixedly mounted on the inner top wall of the cylinder (18), a piston rod (25) is fixedly mounted on the top wall of the piston (19), and the top end of the piston rod (25) extends to the upper side of the cylinder (18), a trigger pressure block (21) is fixedly mounted on the top end of the piston rod (25), a key switch (22) matched with the trigger pressure block (21) is fixedly mounted on the top wall of the cylinder (18), a buzzer alarm (23) is fixedly mounted on the top of the trigger pressure block (21), and the buzzer alarm (23) is electrically connected to the key switch (22); The driving device comprises a servo motor (11), the servo motor (11) is mounted on the air chamber (2) via a motor seat (10), a driving gear (12) is fixedly mounted on the output shaft of the servo motor (11), and a driven gear (13) meshing with the driving gear (12) is mounted on the air pipe (7).

2. The coated sand shell type iron sand negative pressure casting equipment according to claim 1, characterized in that: The key switch (22) is electrically connected to the servo motor (11).

3. The coated sand shell type iron sand negative pressure casting equipment according to claim 1, characterized in that: A dust cover (14) is installed outside the driving gear (12) and the driven gear (13).

4. The coated sand shell type iron sand negative pressure casting equipment according to claim 3 is characterized in that: The dust cover (14) comprises two symmetrically arranged half shells, a rotating shaft (15) is fixedly mounted on the housing (1), the two half shells are rotatably mounted on the rotating shaft (15) and are used to wrap the driving gear (12) and the driven gear (13), the two half shells are jointly provided with a through hole three cooperating with the air pipe (7), the two half shells are jointly provided with a through hole four cooperating with the output shaft of the servo motor (11), the bottom ends of the two half shells are both fixedly mounted with a connecting block (16), and the two connecting blocks (16) are fixedly connected by a connecting screw, and a limiting column (17) located between the two connecting blocks (16) is fixedly mounted on the housing (1).

5. The coated sand shell type iron sand negative pressure casting equipment according to claim 1, characterized in that: The filter screen (3) is coated with a wear-resistant coating.

6. The coated sand shell type iron sand negative pressure casting equipment according to claim 1, characterized in that: The detection device is an air pressure detection device (24) capable of accurately displaying air pressure.

7. A manufacturing process for the coated sand shell type iron sand negative pressure casting equipment according to any one of claims 1 to 6, characterized in that: The steps include: S1: Use a lifting device to place the sand box on a suitable workbench through the lifting ears outside the box body (1); S2: placing the processed coated sand mold shell in the box (1) and burying the sand, and iron sand can be added according to the actual production situation; S3: laying an air isolation layer on the box body (1) to seal the box and passing the gate of the coated sand mold shell through the air isolation layer; S4: Turn on the negative pressure device to perform negative pressure extraction, and inject molten metal through the gate of the coated sand shell; S5: After cooling, stop the negative pressure and take out the molded casting; S6: Screen out the iron sand.

Images