Foundry sand grinding device and grinding method

Abstract

The application provides a foundry sand grinding device and a grinding method, and belongs to the technical field of foundry sand shaping equipment. The foundry sand grinding device comprises a device cylinder, a grinding cylinder, a main grinding assembly and an auxiliary grinding assembly. The grinding cylinder is coaxially arranged with the device cylinder, and the grinding cylinder surrounds a grinding cavity. A plurality of inclined grinding grooves are uniformly distributed on the inner side wall of the grinding cylinder. The main grinding assembly comprises a main rotating shaft and a main fan blade. The lower end of the main rotating shaft penetrates through the bottom of the cylinder and is connected with a main motor located outside the bottom of the cylinder. The upper end of the main rotating shaft is connected with the main fan blade, and the main fan blade is attached to the grinding surface in the device cylinder. The auxiliary grinding assembly comprises an auxiliary rotating shaft and an auxiliary fan blade. The upper end of the auxiliary rotating shaft longitudinally penetrates through the cylinder body and is connected with an auxiliary motor located outside the cylinder body. The lower end of the auxiliary rotating shaft is connected with the auxiliary fan blade. The foundry sand grinding device provided by the application forms a multiple grinding mechanism, specifically grinds off the sharp corners of the sand particles and trims the particle shape, effectively reduces the angular factor of the sand particles, and greatly improves the sand particle grinding efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of casting sand shaping equipment, and more specifically, it relates to a casting sand grinding device and grinding method. Background Technology

[0002] The quality of raw materials and mixtures used for molding and core making, as well as the quality of coatings, directly affects the quality of castings. Therefore, the testing and inspection of raw sand properties are receiving increasing attention in the foundry industry.

[0003] The angularity factor is the ratio of the actual specific surface area to the theoretical specific surface area of ​​foundry silica sand, reflecting the geometric shape of the sand particles. A large angularity factor means the sharp corners of the sand particles are easily broken, making them less durable. Furthermore, as the amount of resin added increases, the gas generation in the sand mold increases, and the gas generation rate also increases accordingly, leading to a decrease in the surface quality of the casting. In practice, the new standard stipulates that the angularity factor of standard foundry sand should not exceed 1.20, raising the requirements for particle roundness and improving the fluidity and filling performance of the standard sand.

[0004] To meet the requirements for particle roundness in foundry sand, silica sand needs to be ground to reduce its angularity factor. Currently, the industry mostly uses silica sand grinding equipment to achieve this goal. However, existing grinding machines have poor grinding consistency when grinding large quantities of silica sand for foundry. Often, due to insufficient grinding, a large amount of silica sand that does not meet the angularity factor standard remains. This requires manual sorting and re-introduction into the grinding process, which is not only time-consuming and labor-intensive but also significantly reduces the overall grinding efficiency, making it difficult to meet the high-efficiency supply requirements of raw sand in foundry production. Summary of the Invention

[0005] The purpose of this invention is to provide a casting sand grinding device and grinding method, which aims to solve the problems of poor grinding effect consistency and low grinding and shaping efficiency.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a casting sand grinding device and grinding method, comprising:

[0007] The equipment cylinder is fixed to the ground by means of an equipment frame; the equipment cylinder includes a cylinder bottom and a cylinder body, the cylinder bottom has a grinding surface for bearing sand particles, and the cylinder body has a feed inlet and a discharge outlet;

[0008] A grinding cylinder is coaxially arranged with the cylinder body, and the grinding cylinder surrounds a grinding chamber; the upper end of the grinding cylinder is open and communicates with the feed port; a discharge port is provided on the side of the grinding cylinder, and an openable sealing plate is provided inside the discharge port; multiple inclined grinding grooves are evenly distributed on the inner side wall of the grinding cylinder.

[0009] The main grinding assembly includes a main shaft and a main fan blade; the lower end of the main shaft passes through the bottom of the cylinder and is connected to a main motor located outside the bottom of the cylinder, and the upper end of the main shaft is connected to the main fan blade, which is in contact with the grinding surface and is used to lift the sand particles on the grinding surface.

[0010] The auxiliary grinding assembly includes an auxiliary shaft and an auxiliary fan blade. The upper end of the auxiliary shaft extends longitudinally through the cylinder and is connected to an auxiliary motor located outside the cylinder. The lower end of the auxiliary shaft is connected to the auxiliary fan blade, which is located above the main fan blade and is used to impact and cut abrasive particles.

[0011] In another embodiment of this application, there are multiple secondary shafts, which are radially distributed around the main shaft.

[0012] In another embodiment of this application, an annular baffle plate is further provided at the top of the grinding cylinder, the annular baffle plate comprising:

[0013] A connecting part, the lower end of which is connected to the upper end face of the grinding cylinder;

[0014] The guide portion is set at an angle to the connecting portion, and the guide portion has a downward tendency to extend from the outside to the inside.

[0015] In another embodiment of this application, the upper opening of the grinding groove extends to the upper end face of the grinding cylinder, and the bottom of the grinding groove is flush with the inner sidewall of the connecting part.

[0016] In another embodiment of this application, the grinding cylinder is fixedly connected to the cylinder body or spaced apart from the cylinder body;

[0017] When the grinding cylinder is fixedly connected to the cylinder body, the discharge port is located inside the outlet port;

[0018] When the grinding cylinder and the cylinder body are spaced apart, a guide plate is provided on the inner side of the cylinder body. The guide plate is located on both sides of the discharge port and connected to the discharge port. The free end of the guide plate is used to extend to the outside of the discharge port.

[0019] In another embodiment of this application, an auxiliary grinding component is sleeved on the secondary rotating shaft, the auxiliary grinding component comprising:

[0020] The traction sleeve is fixed to the outer circumference of the secondary rotating shaft;

[0021] A traction component is mounted on the traction sleeve;

[0022] A grinding block is connected to the free end of the traction member, and the surface of the grinding block is in contact with the inner wall of the grinding cylinder; the hardness of the grinding block is greater than that of the sand grains, and the surface of the grinding block has multiple irregular protrusions.

[0023] In another embodiment of this application, the bottom of the cylinder includes:

[0024] The base is fixedly connected to the equipment frame, and the base is fixedly connected to the cylinder.

[0025] A grinding table is rotatably mounted on the base, and the upper end surface of the grinding table forms the grinding surface;

[0026] The lower end of the grinding cylinder is fixedly connected to the grinding table, and an annular installation space is formed between the grinding cylinder and the cylinder body; a driving component is provided on the outer side of the grinding cylinder.

[0027] In another embodiment of this application, the driving component includes:

[0028] A drive pulley is fitted onto the main shaft located at the bottom of the cylinder;

[0029] A drive shaft extends longitudinally through the bottom of the cylinder and is rotatably connected to the bottom of the cylinder; the upper end of the drive shaft extends into the installation space, the lower end of the drive shaft extends to one side of the drive pulley, and a driven pulley is installed at the lower end of the drive shaft.

[0030] A drive gear set includes a gear and a gear ring; the gear is sleeved on the upper end of the drive shaft, and the gear ring is sleeved on the outside of the grinding cylinder; the gear meshes with the teeth on the outside of the gear ring.

[0031] In another embodiment of this application, there is a speed difference between the rotational speed of the grinding cylinder and the rotational speed of the secondary shaft.

[0032] The beneficial effects of the casting sand grinding device provided by this invention are as follows: Compared with the prior art, the casting sand grinding device of this invention forms a multi-grinding mechanism through the synergistic effect of the main fan blade lifting sand particles and the secondary fan blade impacting and cutting, combined with the friction assistance of the grinding groove on the inner side wall of the grinding cylinder. This mechanism specifically grinds away the sharp corners of sand particles and trims their shape, effectively reducing the angularity factor of the sand particles, making it easier to meet the requirement that the angularity factor of casting sand is not greater than 1.20, thus improving the surface quality of castings from the source; it significantly improves the sand grinding efficiency and shortens the grinding cycle; at the same time, the inclined grinding groove makes all-round contact with the sand particles, reducing the phenomenon of uneven particle size and improving the uniformity of sand grinding.

[0033] A method for grinding foundry sand, employing the aforementioned foundry sand grinding apparatus, is also provided, comprising the following steps:

[0034] S1. Feed the foundry sand into the grinding cylinder through the feed port of the equipment cylinder;

[0035] S2. Start the main motor and auxiliary motor. The main motor drives the main shaft to rotate the main fan blades. The main fan blades, in contact with the grinding surface at the bottom of the cylinder, lift up the sand particles. The auxiliary motor drives the auxiliary shaft to rotate the auxiliary fan blades. The auxiliary fan blades impact the lifted sand particles, and the sand particles fly outward due to centrifugal force under the agitation of the auxiliary fan blades.

[0036] S3. Under the action of centrifugal force, the sand particles hit the inner wall of the grinding cylinder. The larger sand particles first enter the grinding tank under the action of centrifugal force. Under the continuous impact, the sand particles move upward along the grinding tank until they fly out from the top of the grinding tank and fall back into the grinding chamber.

[0037] S4. After grinding is completed, open the sealing plate on the side of the grinding cylinder to allow the sand particles to pass through the discharge port and outlet in sequence to complete the grinding.

[0038] The beneficial effects of the casting sand grinding method provided by the present invention are as follows: Compared with the prior art, the casting sand grinding method of the present invention adopts the above-mentioned casting sand grinding device and has all the beneficial effects it possesses; through the process of "lifting-impacting-in-groove circulation grinding", the sharp corners of the sand particles are specifically ground off, so that the angularity factor of the sand particles is stably controlled within the standard range, solving the problem of low angularity factor compliance rate in the existing methods, and laying the foundation for improving the surface quality of castings. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of the casting sand grinding device provided in an embodiment of the present invention;

[0041] Figure 2 This is a front view of the casting sand grinding apparatus provided in an embodiment of the present invention;

[0042] Figure 3 This is a longitudinal cross-sectional view of the foundry sand grinding device provided in an embodiment of the present invention;

[0043] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0044] Figure 5 A longitudinal cross-sectional view of a foundry sand grinding apparatus provided in another embodiment of the present invention;

[0045] Figure 6 for Figure 5 Enlarged view of point B in the middle.

[0046] In the diagram: 1. Equipment frame; 2. Bottom of cylinder; 3. Cylinder body; 4. Main shaft; 5. Main motor; 6. Auxiliary motor; 7. Auxiliary shaft; 8. Feed inlet; 9. Grinding table; 10. Grinding cylinder; 11. Grinding groove; 12. Annular baffle plate; 13. Main fan blade; 14. Traction sleeve; 15. Traction component; 16. Grinding block; 17. Auxiliary fan blade; 18. Sealing plate; 19. Drive shaft; 20. Gear; 21. Gear ring; 22. Drive pulley; 23. Driven pulley. Detailed Implementation

[0047] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0048] Please see Figures 1 to 6 The casting sand grinding device and grinding method provided by the present invention will now be described. The casting sand grinding device includes an equipment cylinder, a grinding cylinder 10, a main grinding assembly, and a secondary grinding assembly. The equipment cylinder is fixed to the ground by an equipment frame 1. The equipment cylinder includes a bottom 2 and a body 3. The bottom 2 has a grinding surface for bearing sand particles, and the body 3 has an inlet 8 and an outlet. The grinding cylinder 10 is coaxially arranged with the body 3, and the grinding cylinder 10 surrounds a grinding chamber. The upper end of the grinding cylinder 10 is open and communicates with the inlet 8. A discharge port is provided on the side of the grinding cylinder 10, and an openable sealing plate 18 is provided inside the discharge port. Multiple inclined plates are evenly distributed on the inner wall of the grinding cylinder 10. The grinding groove 11 is inclined; the main grinding assembly includes a main rotating shaft 4 and a main fan blade 13; the lower end of the main rotating shaft 4 passes through the bottom of the cylinder 2 and is connected to the main motor 5 located outside the bottom of the cylinder 2, and the upper end of the main rotating shaft 4 is connected to the main fan blade 13, which is in contact with the grinding surface and is used to lift the sand particles on the grinding surface; the auxiliary grinding assembly includes an auxiliary rotating shaft 7 and an auxiliary fan blade 17, the upper end of the auxiliary rotating shaft 7 passes through the cylinder 3 longitudinally and is connected to the auxiliary motor 6 located outside the cylinder 3, and the lower end of the auxiliary rotating shaft 7 is connected to the auxiliary fan blade 17, which is located above the main fan blade 13 and is used to impact and cut the sand particles.

[0049] The casting sand grinding device provided by the present invention allows casting sand to enter the grinding chamber surrounded by the grinding cylinder 10 through the feed port 8 on the cylinder 3, and the sand particles accumulate on the grinding surface. The main motor 5 drives the main rotating shaft 4 to rotate, which drives the main fan blade 13 connected to the upper end of the main rotating shaft 4 to rotate at high speed on the grinding surface of the bottom 2 of the cylinder. The movement of the main fan blade 13 against the grinding surface lifts the sand particles accumulated on the grinding surface upward, so that the sand particles are removed from the accumulated state and are in a suspended or moving state.

[0050] The auxiliary motor 6 drives the auxiliary shaft 7 to rotate, which in turn drives the auxiliary fan blade 17, located above the main fan blade 13, to rotate synchronously. The auxiliary fan blade 17 directly impacts and cuts the sand particles thrown up by the main fan blade 13, further crushing and refining the sand particles. In addition, the sand particles rotate rapidly under the action of the high-speed rotating auxiliary fan blade 17 and are subjected to centrifugal force; under the action of centrifugal force, the sand particles fly outward. Because the larger the sand particles, the greater the centrifugal force they experience, the larger sand particles first impact the inner wall of the grinding cylinder 10 under the action of centrifugal force, and some of the sand particles enter the grinding groove 11.

[0051] Under the centrifugal force of the sand particles, the sand particles move upwards at an angle along the length of the grinding tank 11. During the movement, the sand particles rub against the bottom of the grinding tank 11, and the movement of the sand particles in the grinding tank 11 accelerates the grinding process. After the grinding is completed, the sealing plate 18 of the discharge port is opened, and the sand particles are discharged through the discharge port to the discharge port of the equipment cylinder, completing the entire grinding process.

[0052] The casting sand grinding device provided by this invention, compared with the prior art, forms a multi-grinding mechanism through the synergistic effect of the main fan blade 13 lifting sand particles and the secondary fan blade 17 impacting and cutting them, combined with the friction assistance of the grinding groove 11 on the inner side wall of the grinding cylinder 10. This mechanism specifically grinds away the sharp corners of the sand particles and trims their shape, effectively reducing the angularity factor of the sand particles. This makes it easier for the sand used in casting (such as silica sand) to meet the requirement that the angularity factor should not exceed 1.20, thus improving the surface quality of the castings from the source. It also significantly improves the sand grinding efficiency and shortens the grinding cycle. At the same time, the inclined grinding groove 11 makes all-round contact with the sand particles, reducing the phenomenon of uneven particle size and improving the uniformity of sand grinding.

[0053] Furthermore, this application allows for the control of the motion intensity of the main fan blade 13 and the secondary fan blade 17 by adjusting the speeds of the main motor 5 and the secondary motor 6, thus adapting to the grinding requirements of casting sand with different particle sizes and offering high flexibility. The sand particles ground by this device have a more rounded shape and a lower angularity factor, which improves its fluidity and filling performance, reduces the amount of binders such as resin, and lowers the amount and rate of gas generation in the sand mold. This not only makes it suitable for subsequent casting processes such as molding and core making but also helps to further improve the quality of castings.

[0054] During the grinding process, spherical or block-shaped auxiliary grinding parts can be added into the grinding chamber. These auxiliary grinding parts have a hardness greater than that of the abrasive grains, such as alumina balls, silicon carbide ceramics, or coarse quartz sand particles. During grinding, the auxiliary grinding parts are simultaneously conveyed into the grinding chamber along with the abrasive grains and driven by both the main and auxiliary blades. Due to the greater hardness of the auxiliary grinding parts, they effectively assist in grinding the abrasive grains. Under centrifugal force, the auxiliary grinding parts are thrown against the inner wall of the grinding cylinder 10 and move along it, crushing and colliding with the abrasive grains within the grinding cylinder 10 and the grinding groove 11 during this movement.

[0055] The sealing plate 18 of the grinding cylinder 10 is hinged to one side of the discharge port of the grinding cylinder 10, and a mechanical handle lock and a bolt lock are provided on the other side of the sealing plate 18.

[0056] In some possible embodiments, please refer to Figure 1 There are multiple secondary shafts 7, which are radially distributed around the main shaft 4.

[0057] Multiple auxiliary shafts 7 are arranged radially around the main shaft 4. During operation, multiple auxiliary motors 6 synchronously drive the multiple auxiliary shafts 7 to rotate, causing their respective connected auxiliary fan blades 17 to form a radial impact and cutting area above the main fan blade 13. When the sand particles raised by the main fan blade 13 move in the grinding chamber, they are simultaneously or alternately impacted and cut by the auxiliary fan blades 17 in multiple directions, and the frictional contact between the sand particles and the grinding grooves 11 on the inner wall of the grinding cylinder 10 is also more thorough due to the agitation of the multiple auxiliary fan blades 17.

[0058] Multiple auxiliary motors 6 are installed around the cylinder 3, with the drive end of the auxiliary motors 6 extending above the cylinder 3. A pulley is provided at the upper end of the auxiliary shaft 7, and the auxiliary motors 6 drive the pulley 22 to rotate via a belt, thereby driving the auxiliary shaft 7 and the auxiliary fan blades 17 to rotate.

[0059] Multiple radially distributed secondary fan blades 17 form a three-dimensional impact cutting net, which can achieve multi-directional and dead-angle-free action on the sand particles raised by the main fan blades 13, and can grind away the sharp corners of the sand particles more quickly, further reduce the angle factor, and shorten the time to achieve the target particle shape roundness.

[0060] In some possible embodiments, please refer to Figure 3 The top of the grinding cylinder 10 is also provided with an annular baffle plate 12, which includes a connecting part and a guiding part; the lower end of the connecting part is connected to the upper end face of the grinding cylinder 10; the guiding part is set at an angle to the connecting part, and the guiding part has a downward trend from the outside to the inside.

[0061] An annular baffle plate 12 is added to the top of the grinding cylinder 10. Its connecting part is fixed to the upper end face of the grinding cylinder 10, and the guide part has a downward inclined angle structure from the outside to the inside. When the casting sand enters from the feed port 8, it first contacts the upper end face of the guide part of the annular baffle plate 12. Due to the inclined trend of the guide part, the sand particles are guided to slide inward and finally accurately enter the grinding chamber of the grinding cylinder 10.

[0062] Meanwhile, the lower end face of the guide section can prevent sand particles from splashing out of the grinding chamber from the upper opening of the grinding cylinder 10 due to impact and lifting during the grinding process, ensuring that the sand particles are concentrated in the grinding area. The annular baffle 12 prevents sand particles from splashing, allowing the sand particles to concentrate in the grinding chamber and fully interact with the main fan blade 13, the secondary fan blade 17, and the grinding groove 11, reducing the problem of insufficient grinding in some areas caused by the dispersion of sand particles, further ensuring the consistency of the reduction of the sand particle angular factor, and making it easier to achieve the roundness standard.

[0063] Under centrifugal force, the sand particles slowly rise along the grinding groove 11 to the top of the grinding cylinder 10, and then return to the grinding chamber under the inclined guidance of the lower end of the guide section, and are driven to rotate again by the auxiliary fan blade 17.

[0064] The connecting part extends horizontally or upward, and the connection between the connecting part and the guide part is the highest point of the annular baffle plate 12. The sand particles flying out from the upper end of the grinding tank 11 reach the highest point at the connection between the connecting part and the guide part, and then move downward with the guide part until they fall back into the grinding chamber.

[0065] Specifically, the upper opening of the grinding groove 11 extends to the upper end face of the grinding cylinder 10, and the bottom of the grinding groove 11 is flush with the inner wall of the connecting part.

[0066] The upper opening of the grinding tank 11 extends to the upper end face of the grinding cylinder 10, and the bottom of the tank is flush with the inner wall of the connecting part of the annular baffle plate 12. When the sand particles are guided down by the guide part, because the inner wall of the connecting part is flush with the bottom of the grinding tank 11, the sand particles can smoothly transition into the grinding tank 11. With the lifting and impact movement of the sand particles during the grinding process, the grinding tank 11 forms a continuous friction contact path from the upper opening to the inside of the tank. The sand particles can enter the grinding tank 11 in the early stage of entering the grinding chamber and continue to rub against the tank wall with the movement, realizing seamless grinding from the feeding stage to the grinding stage.

[0067] The upper opening of the grinding groove 11 extends to the end face and is flush with the inner wall of the connecting part. This avoids local accumulation of sand particles when they enter the grinding chamber due to height difference or step obstruction, making the transition of sand particles from the guide part to the grinding groove 11 smoother. It also avoids the obstruction of sand particle movement or loss of kinetic energy caused by structural abrupt changes, ensuring that a large number of sand particles continuously and stably participate in the grinding process.

[0068] In some possible embodiments, please refer to Figures 3 to 6 The grinding cylinder 10 is fixedly connected to the cylinder body 3 or spaced apart from the cylinder body 3; when the grinding cylinder 10 is fixedly connected to the cylinder body 3, the discharge port is located inside the discharge port; when the grinding cylinder 10 is spaced apart from the cylinder body 3, a guide plate is provided on the inner side of the cylinder body 3, the guide plate is located on both sides of the discharge port and connected to the discharge port, and the free end of the guide plate is used to extend to the outside of the discharge port.

[0069] The connection between the grinding cylinder 10 and the equipment cylinder can be configured in two ways. When the grinding cylinder 10 is fixedly connected to the cylinder body 3, the discharge port on the side of the grinding cylinder 10 and the discharge port of the cylinder body 3 form an inner-outer correspondence. After the ground sand particles are discharged from the discharge port, they are directly discharged from the equipment through the inner discharge port, thus achieving short-path discharge.

[0070] When the grinding cylinder 10 and the cylinder body 3 are spaced apart, the free end of the guide plate inside the cylinder body 3 extends to the outside of the discharge port. After the sand particles are discharged from the discharge port, they fall into the gap between the grinding cylinder 10 and the cylinder body 3, and are then guided by the guide plate to the discharge port for discharge, forming a long-path discharge channel through the guide plate. The end of the guide plate is either in contact with the grinding cylinder 10 or has a gap.

[0071] In some possible embodiments, please refer to Figures 3 to 4 An auxiliary grinding component is fitted on the secondary rotating shaft 7. The auxiliary grinding component includes a traction sleeve 14, a traction member 15, and a grinding block 16. The traction sleeve 14 is fixed to the outer periphery of the secondary rotating shaft 7. The traction member 15 is disposed on the traction sleeve 14. The grinding block 16 is connected to the free end of the traction member 15, and the surface of the grinding block 16 is in contact with the inner side wall of the grinding cylinder 10. The hardness of the grinding block 16 is greater than that of the sand grains, and the surface of the grinding block 16 has multiple irregular protrusions.

[0072] The traction sleeve 14 is fixed on the auxiliary shaft 7, and has multiple hinged mounting positions on its outer side. The traction member 15 is a rod-shaped structure, and its upper end is hinged to the traction sleeve 14. The hinge direction can be longitudinal, transverse, or inclined. A grinding block 16 is rotatably mounted on the free end of the traction member 15. When the auxiliary shaft 7 rotates, the grinding block 16 rotates synchronously.

[0073] The horizontal length of the grinding element is less than the horizontal distance between two adjacent secondary rotating shafts 7. Furthermore, to avoid impact, the grinding elements on adjacent secondary rotating shafts 7 are staggered.

[0074] The grinding block 16 is attached to the inner wall of the grinding cylinder 10. When the auxiliary shaft 7 rotates, the grinding block 16 will move relative to the inner wall of the grinding cylinder 10. The friction between the grinding cylinder 10 and the grinding block 16 will cause the grinding block 16 to rotate horizontally.

[0075] The grinding block 16 can be spherical, longitudinal cylindrical or polygonal prism.

[0076] Multiple traction components 15 connected to the same traction sleeve 14 can have different lengths, so that different grinding blocks 16 fit at different heights of the grinding cylinder 10.

[0077] When the secondary shaft 7 rotates, the traction sleeve 14 fixed to its outer periphery rotates synchronously, driving the traction member 15 on the traction sleeve 14 to move together with the secondary shaft 7, thereby pulling the grinding block 16 connected to the free end to rotate around the secondary shaft 7. Since the surface of the grinding block 16 is in contact with the inner wall of the grinding cylinder 10 and its hardness is greater than that of the sand grains, during the rotation, the irregular protrusions on the surface of the grinding block 16 will squeeze, scrape and cut the sand grains between the inner wall of the grinding cylinder 10; at the same time, the contact between the protrusions and the sand grains can further break the sharp corners of the sand grains, and through the relative movement between the grinding block 16 and the inner wall of the grinding cylinder 10, a clamping grinding effect is formed on the sand grains. Combined with the impact cutting of the main fan blade 13 and the secondary fan blade 17 and the friction of the grinding groove 11, multiple grinding synergy is achieved.

[0078] In some possible embodiments, please refer to Figures 5 to 6 The bottom of the cylinder 2 includes a base and a grinding table 9; the base is fixedly connected to the equipment frame 1 and the base is fixedly connected to the cylinder 3; the grinding table 9 is rotatably mounted on the base, and the upper end surface of the grinding table 9 forms a grinding surface; the lower end of the grinding cylinder 10 is fixedly connected to the grinding table 9, and an annular installation space is formed between the grinding cylinder 10 and the cylinder 3; a drive assembly is provided on the outer side of the grinding cylinder 10.

[0079] A rotary support is provided between the base and the grinding table 9. The grinding table 9 and the grinding cylinder 10 are fixedly connected by bolts or other structures. During the grinding process, the grinding table 9 and the grinding cylinder 10 rotate synchronously.

[0080] There is a speed difference between the rotational speed of the grinding table 9 and the rotational speed of the main spindle 4.

[0081] The drive assembly is located in the annular mounting space outside the grinding cylinder 10. During operation, the drive assembly drives the grinding cylinder 10 to rotate, which in turn drives the grinding table 9 to rotate synchronously around the base. At this time, the main fan blade 13 rotates relative to the grinding surface under the drive of the main motor 5, and the auxiliary fan blade 17 rotates relative to the grinding cylinder 10 under the drive of the auxiliary motor 6. The abrasive particles are subjected to multi-directional friction, impact, and cutting action in the relative motion of the grinding surface, the inner wall of the grinding cylinder 10, the main fan blade 13, and the auxiliary fan blade 17.

[0082] The rotation of the grinding cylinder 10 causes the sand particles inside the cavity to move in a circular motion along the cylinder wall. Combined with the lifting effect of the main fan blade 13 and the impact effect of the auxiliary fan blade 17, the sand particles form a complex spiral motion trajectory in the grinding cavity, which makes more sufficient contact with the grinding surface, grinding groove 11 and fan blade, avoids local insufficient grinding, and reduces the problem of non-compliance of the angle factor due to the difference in particle shape.

[0083] Optionally, a sealing ring is provided between the grinding table 9 and the grinding cylinder 10 to prevent sand particles from entering the gap between them.

[0084] In some possible embodiments, please refer to Figure 5The drive assembly includes a drive pulley 22, a drive shaft 19, and a drive gear set. The drive pulley 22 is sleeved on the main rotating shaft 4 located at the bottom of the cylinder 2. The drive shaft 19 extends longitudinally through the bottom of the cylinder 2 and is rotatably connected to the bottom of the cylinder 2. The upper end of the drive shaft 19 extends into the installation space, and the lower end of the drive shaft 19 extends to one side of the drive pulley 22. A driven pulley 23 is installed at the lower end of the drive shaft 19. The drive gear set includes a gear 20 and a gear ring 21. The gear 20 is sleeved on the upper end of the drive shaft 19, and the gear ring 21 is sleeved on the outer side of the grinding cylinder 10. The gear 20 meshes with the outer teeth of the gear ring 21.

[0085] The drive assembly achieves the rotation drive of the grinding cylinder 10 and the grinding table 9 through the cooperation of belt drive and gear 20 drive.

[0086] When the main motor 5 drives the main shaft 4 to rotate, the drive pulley 22 sleeved on the main shaft 4 rotates synchronously. Through belt transmission, it drives the driven pulley 23 at the lower end of the drive shaft 19 to rotate, causing the drive shaft 19, which runs longitudinally through the bottom of the cylinder 2, to rotate accordingly. The upper end of the drive shaft 19 extends into the annular mounting space, and the gear 20 sleeved at its top rotates accordingly. Because the gear 20 meshes with the gear ring 21 sleeved on the outside of the grinding cylinder 10, the rotation of the gear 20 is transmitted through the gear ring 21 to drive the grinding cylinder 10 to rotate around its own axis, thereby driving the grinding table 9, which is fixedly connected to the grinding cylinder 10, to rotate synchronously. By matching the transmission ratio of the pulley with the transmission ratio of the gear 20, a preset speed difference is formed between the grinding cylinder 10, the main shaft 4, and the auxiliary shaft 7, enhancing the relative movement between the abrasive grains and each grinding component.

[0087] This application, through the transmission ratio design of the drive pulley 22 and the driven pulley 23, combined with the meshing transmission of the gear 20 and the gear ring 21, can precisely control the speed difference between the grinding cylinder 10, the main rotating shaft 4, and the auxiliary fan blade 17.

[0088] Optionally, there is a speed difference between the rotational speed of the grinding cylinder 10 and the rotational speed of the auxiliary shaft 7.

[0089] The grinding cylinder 10 and the auxiliary shaft 7 are set to rotate at different speeds. When the drive assembly drives the grinding cylinder 10 to rotate, and the auxiliary motor 6 drives the auxiliary shaft 7 to rotate, the speed difference between the two causes relative motion between the inner wall of the grinding cylinder 10 and the auxiliary fan blade 17 and auxiliary grinding components: if the grinding cylinder 10 and the auxiliary shaft 7 rotate in the same direction, the speed difference is reflected as the superposition of relative velocities; if they rotate in opposite directions, the speed difference is reflected as the superposition of absolute velocities. This relative motion causes the sand particles to experience stronger shearing, impact, and friction between the inner wall of the grinding cylinder 10 and the auxiliary fan blade 17 and grinding block 16, which, combined with the lifting action of the main fan blade 13, further enhances the particle shape trimming effect of the sand particles.

[0090] A method for grinding foundry sand, employing the aforementioned foundry sand grinding apparatus, is also provided, comprising the following steps:

[0091] S1. Feed the casting sand into the grinding cylinder 10 through the feed port 8 of the equipment cylinder;

[0092] S2. Start the main motor 5 and the auxiliary motor 6. The main motor 5 drives the main shaft 4 to rotate the main fan blade 13. The main fan blade 13 contacts the grinding surface of the bottom of the cylinder 2 and lifts up the sand particles. The auxiliary motor 6 drives the auxiliary shaft 7 to rotate the auxiliary fan blade 17. The auxiliary fan blade 17 impacts the lifted sand particles, and the sand particles fly outward due to centrifugal force under the agitation of the auxiliary fan blade 17.

[0093] S3. Under the action of centrifugal force, the sand particles hit the inner wall of the grinding cylinder 10. The larger sand particles first enter the grinding tank 11 under the action of centrifugal force. Under the continuous impact, the sand particles move upward along the grinding tank 11 until they fly out from the upper part of the grinding tank 11 and fall back into the grinding chamber.

[0094] S4. After grinding is completed, open the sealing plate 18 on the side of the grinding cylinder 10 so that the sand particles pass through the discharge port and the outlet in sequence to complete the grinding.

[0095] Under the action of centrifugal force, the sand particles impact the inner wall of the grinding cylinder 10. The larger sand particles have stronger inertia and preferentially enter the grinding groove 11 on the inner wall. Under continuous impact and agitation, the sand particles move upward along the inclined grinding groove 11 and eventually fly out from the upper part of the grinding groove 11, fall back into the grinding chamber, and are once again lifted up by the main fan blade 13 and impacted by the secondary fan blade 17, forming a cyclic grinding process of "lifting up - impacting the groove - grinding - falling down", gradually removing sharp corners and reducing the angular factor.

[0096] Larger sand particles are preferentially fed into the grinding tank 11 for intensive grinding, while smaller particles are gradually refined during the circulation process, forming a graded processing mechanism of "focusing on grinding large particles and circulating grinding small particles". This reduces the particle size difference between sand particles, improves the overall particle shape uniformity, and avoids manual sorting and rework.

[0097] The casting sand grinding method provided by this invention, compared with the prior art, adopts the above-mentioned casting sand grinding device and has all its beneficial effects; through the process of "lifting-impacting-in-groove circulation grinding", the sharp corners of sand particles are specifically ground off, so that the angularity factor of sand particles is stably controlled within the standard range, solving the problem of low angularity factor compliance rate in the existing methods, and laying the foundation for improving the surface quality of castings.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A foundry sand grinding device, characterized in that, include: The equipment cylinder is fixed to the ground by means of the equipment frame (1); the equipment cylinder includes a cylinder bottom (2) and a cylinder body (3), the cylinder bottom (2) has a grinding surface for bearing sand particles, and the cylinder body (3) is provided with a feed inlet (8) and a discharge outlet; A grinding cylinder (10) is coaxially arranged with the cylinder body (3), and the grinding cylinder (10) surrounds the grinding chamber; the upper end of the grinding cylinder (10) is open and communicates with the feed port (8); the side of the grinding cylinder (10) is provided with a discharge port, and the discharge port has an openable sealing plate (18); a plurality of inclined grinding grooves (11) are evenly distributed on the inner side wall of the grinding cylinder (10); The main grinding assembly includes a main rotating shaft (4) and a main fan blade (13); the lower end of the main rotating shaft (4) passes through the bottom of the cylinder (2) and is connected to the main motor (5) located outside the bottom of the cylinder (2); the upper end of the main rotating shaft (4) is connected to the main fan blade (13); the main fan blade (13) is attached to the grinding surface and is used to lift the sand particles on the grinding surface. The auxiliary grinding assembly includes an auxiliary shaft (7) and an auxiliary fan blade (17). The upper end of the auxiliary shaft (7) extends longitudinally through the cylinder (3) and is connected to an auxiliary motor (6) located outside the cylinder (3). The lower end of the auxiliary shaft (7) is connected to the auxiliary fan blade (17), which is located above the main fan blade (13) and is used to impact and cut abrasive particles.

2. The casting sand grinding device as described in claim 1, characterized in that, There are multiple secondary shafts (7), and the multiple secondary shafts (7) are radially distributed around the main shaft (4).

3. The casting sand grinding device as described in claim 1, characterized in that, The grinding cylinder (10) is also provided with an annular baffle plate (12) at its top, the annular baffle plate (12) comprising: The lower end of the connecting part is connected to the upper end face of the grinding cylinder (10); The guide portion is set at an angle to the connecting portion, and the guide portion has a downward tendency to extend from the outside to the inside.

4. The casting sand grinding device as described in claim 3, characterized in that, The upper opening of the grinding groove (11) extends to the upper end face of the grinding cylinder (10), and the bottom of the grinding groove (11) is flush with the inner wall of the connecting part.

5. The casting sand grinding device as described in claim 1, characterized in that, The grinding cylinder (10) is fixedly connected to the cylinder body (3) or spaced apart from the cylinder body (3); When the grinding cylinder (10) is fixedly connected to the cylinder body (3), the discharge port is located inside the outlet port; When the grinding cylinder (10) and the cylinder body (3) are spaced apart, a guide plate is provided on the inner side of the cylinder body (3). The guide plate is located on both sides of the discharge port and connected to the discharge port. The free end of the guide plate is used to extend to the outside of the discharge port.

6. The casting sand grinding device as described in claim 1, characterized in that, An auxiliary grinding component is fitted onto the secondary rotating shaft (7), the auxiliary grinding component comprising: The traction sleeve (14) is fixed to the outer periphery of the auxiliary rotating shaft (7); A traction component (15) is disposed on the traction sleeve (14); A grinding block (16) is connected to the free end of the traction member (15), and the surface of the grinding block (16) is in contact with the inner wall of the grinding cylinder (10); the hardness of the grinding block (16) is greater than that of the sand grains, and the surface of the grinding block (16) has multiple irregular protrusions.

7. The casting sand grinding device as described in claim 1, characterized in that, The bottom of the cylinder (2) includes: The base is fixedly connected to the equipment frame (1), and the base is fixedly connected to the cylinder (3); A grinding table (9) is rotatably mounted on the base, and the upper end surface of the grinding table (9) forms the grinding surface; The lower end of the grinding cylinder (10) is fixedly connected to the grinding table (9), and an annular installation space is formed between the grinding cylinder (10) and the cylinder body (3); a driving component is provided on the outer side of the grinding cylinder (10).

8. The casting sand grinding apparatus as described in claim 7, characterized in that, The driving component includes: The drive pulley (22) is sleeved on the main shaft (4) located at the bottom (2) of the cylinder; A drive shaft (19) extends longitudinally through the bottom of the cylinder (2) and is rotatably connected to the bottom of the cylinder (2); the upper end of the drive shaft (19) extends into the installation space, the lower end of the drive shaft (19) extends to one side of the drive pulley (22), and a driven pulley (23) is installed at the lower end of the drive shaft (19); The drive gear set includes a gear (20) and a gear ring (21); the gear (20) is sleeved on the upper end of the drive shaft (19), and the gear ring (21) is sleeved on the outside of the grinding cylinder (10); the gear (20) meshes with the teeth on the outside of the gear ring (21).

9. The casting sand grinding apparatus as described in claim 8, characterized in that, There is a speed difference between the rotational speed of the grinding cylinder (10) and the rotational speed of the auxiliary shaft (7).

10. A method for grinding foundry sand, employing the foundry sand grinding apparatus as described in claim 1, characterized in that, Includes the following steps: S1. The casting sand is fed into the grinding cylinder (10) through the feed port (8) of the equipment cylinder; S2. Start the main motor (5) and the auxiliary motor (6). The main motor (5) drives the main shaft (4) to rotate the main fan blade (13). The main fan blade (13) is in contact with the grinding surface of the bottom of the cylinder (2) and lifts up the sand particles. The auxiliary motor (6) drives the auxiliary shaft (7) to rotate the auxiliary fan blade (17). The auxiliary fan blade (17) impacts the lifted sand particles, and the sand particles fly outward due to centrifugal force under the stirring of the auxiliary fan blade (17). S3. Under the action of centrifugal force, the sand particles hit the inner wall of the grinding cylinder (10). The larger sand particles first enter the grinding tank (11) under the action of centrifugal force. Under the continuous impact, the sand particles move upward along the grinding tank (11) until they fly out from the upper part of the grinding tank (11) and fall back into the grinding chamber. S4. After grinding is completed, open the sealing plate (18) on the side of the grinding cylinder (10) so that the sand particles pass through the discharge port and the outlet in sequence to complete the grinding.

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