Sand expansion prevention system for sand mold casting without sand box
By setting up a clamping mechanism in sandless vertical parting casting, the problem of sand expansion was solved, ensuring the dimensional accuracy and mechanical properties of the castings and realizing continuous automated production.
Patent Information
- Application Number
- CN202510951250.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2025-11-18
AI Technical Summary
Sand expansion is a problem in sandless vertical parting casting, which leads to reduced dimensional accuracy of castings, increased machining costs, and decreased mechanical properties of castings. Existing solutions cannot effectively solve this problem.
A sand-expansion prevention system for sand casting without a sand box was designed. By setting clamping mechanisms on both sides of the sand mold conveying system, including sleeves, clamping rods, pressure plates and contact plates, the continuous clamping of the sand mold is achieved by using a transmission chain and drive mechanism to counteract the impact force of molten metal.
It effectively prevents sand expansion caused by molten metal pressure during the casting process, ensuring the dimensional accuracy and mechanical properties of the castings and meeting the continuous requirements of automated production.
Smart Images
Figure CN120961848A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of casting technology, and in particular to an anti-expansion sand system for sand casting without a sandbox. Background Technology
[0002] Casting, as an important metal forming process, occupies a key position in modern industrial production. Sand-free vertical parting casting technology, with its unique advantages such as high production efficiency, high casting precision, and good automation potential, stands out among many casting processes and is widely used in automotive parts, machinery manufacturing, and other fields.
[0003] Sandless boxless vertical parting casting utilizes the principle of combining "sand shooting" and "extrusion" to compact the sand mold, employing a double-sided cavity vertical parting process. During casting, the positive pressure mold of the sand shot ejects the sand mold, which then fits tightly against the previous sand mold, completing the mold closure and forming horizontally arranged boxless casting molds. However, in actual production, this process faces the thorny problem of sand bulging. Sand bulging refers to the localized expansion of the casting surface, forming irregular, nodular metal protrusions. This defect not only severely affects the dimensional accuracy of the casting, leading to increased time and cost in subsequent machining to correct dimensional deviations, but also increases unnecessary consumption of metal materials. More importantly, sand bulging defects also reduce the overall mechanical properties and reliability of the casting, having a significant negative impact on the quality of the casting product.
[0004] The causes of sand expansion are complex, mainly including the pressure of the molten metal filling, the pressure of gas expansion within the mold, or the expansion force of graphitization of cast iron during solidification. When these pressures act on the mold cavity, the cavity will shift, resulting in sand expansion. For boxless sand molds, due to the lack of external constraint from the sand box, they are more vulnerable to these pressures, making the sand expansion problem more prominent. Currently, although some solutions exist for the sand expansion problem in boxless vertical parting casting, such as optimizing the molding sand formula to improve mold strength and improving the gating system design to reduce filling pressure, these methods often have limitations and cannot fundamentally and effectively solve the sand expansion problem, leading to a high scrap rate in the production process and seriously restricting the further promotion and application of boxless vertical parting casting technology. Therefore, developing a casting system that can effectively solve the sand expansion problem in boxless sand molds is of significant practical importance and urgency. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a sand-expansion prevention system for sand casting without a sand box. This system is reasonably designed, easy to use, and can solve the aforementioned problems.
[0006] The technical solution adopted by this invention to solve its technical problem is: a sand-expanding anti-sand system for sand casting without a sand box, comprising a first conveying mechanism located on both sides of a sand mold conveying system. The first conveying mechanism includes a driving wheel, a driven wheel, and a transmission chain. The driving wheel is connected to a first driving device that drives the driving wheel to rotate. The transmission chain is provided with a plurality of sleeves, the axial direction of which is perpendicular to the movement direction of the transmission chain. A clamping rod is slidably connected inside the sleeve. At one end of the sleeve near the sand mold conveying system, the clamping rod is provided with a pressure plate, and at the other end, a contact plate that can contact the clamping rod is provided. After one end of the clamping rod contacts the contact plate, the pressure plate clamps the sand mold on the sand mold conveying system. A push plate is provided at the input end of the transmission chain. The push plate is provided with a second driving mechanism that drives the push plate to reciprocate along the axial direction of the clamping rod. After the second driving device drives the push plate to move towards the sand mold, the surface of the push plate is flush with the surface of the contact plate.
[0007] Furthermore, the contact plate is parallel to the side of the sand mold on the sand mold conveying system and is located at the top of the transmission chain.
[0008] Furthermore, a roller is provided at the end of the clamping rod, and the clamping rod is slidably connected to the contact plate through the roller.
[0009] Furthermore, a telescopic spring is sleeved on the outside of the clamping rod, and the telescopic spring is located between the sleeve and the abutment plate.
[0010] Furthermore, the inner wall of the sleeve is provided with a groove, and the outside of the clamping rod is provided with a protrusion that cooperates with the groove. The length direction of the groove is consistent with the axial direction of the sleeve.
[0011] Furthermore, the surface of the pressure plate is provided with an anti-slip texture.
[0012] Furthermore, the first conveying mechanism includes two sets of parallel transmission chains, and both ends of the sleeve are fixedly connected to the two sets of transmission chains.
[0013] Furthermore, at least two sets of clamping rods are simultaneously in contact with the surface of the contact plate.
[0014] Furthermore, the length of the pressure plate is greater than the thickness of the sand mold.
[0015] Furthermore, the sleeve is provided with adjusting rods and adjusting blocks that can slide in contact with the adjusting rods at both ends. The adjusting blocks are connected to the sleeve, and the side of the adjusting block that contacts the adjusting rod is perpendicular to the sleeve. The axis of the adjusting rod is consistent with the conveying direction of the transmission chain.
[0016] The beneficial effects of this invention are: 1. The sleeve, clamping rod, and pressure plate of the present invention form a clamping mechanism. During the conveying process of the first conveying mechanism, the clamping rod and the contact plate work together. The end of the clamping rod abuts against the contact plate, so that the pressure plate presses the side of the sand mold. The two pressure plates apply a certain pressure to the two sides of the sand mold, so that friction is generated between the pressure plate and the sand mold, which counteracts the impact force of the molten metal on the sand mold during pouring and prevents the sand mold from expanding due to the force pushing. 2. The second drive mechanism drives the push plate to reciprocate, allowing the clamping rod and pressure plate to move closer to the sand mold. Simultaneously, it enables the clamping mechanism to smoothly enter the corresponding area of the contact plate along the push plate, achieving reliable clamping of the sand mold by the pressure plate. During the continuous cyclic conveying process of the first conveying mechanism, the second drive mechanism, push plate, and contact plate cooperate to ensure that the clamping rod can continuously and stably clamp the sand mold moving on the sand mold conveying system, meeting the continuous requirements of automated casting production. 3. The groove on the inner wall of the sleeve cooperates with the protrusion of the clamping rod to prevent the clamping rod from rotating inside the sleeve, ensuring that the pressure plate always presses the side of the sand mold in a consistent direction, and avoiding pressure deviation caused by the misalignment of the pressure plate. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the present invention.
[0018] Figure 2 This is the front view of the present invention.
[0019] Figure 3 This is a side view of the present invention.
[0020] Figure 4 yes Figure 3 A magnified view of the local structure.
[0021] Figure 5 This is a top view of the present invention.
[0022] Figure 6 This figure is a partial structural schematic diagram of the present invention.
[0023] Explanation of reference numerals in the attached figures: 1—First conveying mechanism, 11—Driving wheel, 12—Driven wheel, 13—Transmission chain, 2—Sleeve, 21—Groove, 3—Pressure rod, 31—Roller, 32—Protrusion, 4—Pressure plate, 5—Abutting plate, 6—Push plate, 7—Second drive mechanism, 8—Telescopic spring, 9—Adjusting rod, 10—Adjusting block, 20—Sand mold conveying system. Detailed Implementation
[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.
[0025] It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0027] like Figures 1-6As shown, this embodiment of a sand-boxless sand casting anti-expansion sand system includes a first conveying mechanism 1 located on both sides of a sand mold conveying system 20. After the sand shot machine forms the sand mold, it pushes the sand mold onto the sand mold conveying system 20, where adjacent sand molds fit together to form a complete cavity for the casting. The sand mold conveying system 20 is used to convey the tightly fitted sand molds. The sand mold conveying system 20 adopts a stepping or intermittent conveying method. A pouring position is provided in the sand mold conveying system 20 to realize simultaneous conveying and pouring of molten metal. The first conveying mechanism 1 includes a drive wheel. 11. Driven wheel 12 and transmission chain 13. The driving wheel 11 is connected to a first driving device that drives the driving wheel 11 to rotate. The first driving device is synchronized with the driving device of the sand mold conveying system 20. The first driving device can be a conventional gear drive or chain drive. The transmission chain 13 can be a chain or a conveyor belt. The transmission chain 13 is provided with a plurality of sleeves 2, which are evenly distributed on the transmission chain 13. The distance between two adjacent sleeves 2 is set according to actual production needs. The axial direction of the sleeves 2 is... Perpendicular to the direction of movement of the transmission chain 13, i.e., the axial direction of the sleeve 2 is perpendicular to the direction of movement of the sand mold conveying system 20, a clamping rod 3 is slidably connected inside the sleeve 2. Near one end of the sleeve 20, a pressure plate 4 is provided on the clamping rod 3, and a contact plate 5 is provided at the other end. After one end of the clamping rod 3 contacts the contact plate 5, the pressure plate 4 presses the sand mold on the sand mold conveying system 20. That is, the pressure plates 4 on both sides apply a certain pressure to the sand mold from both sides, thereby preventing… The phenomenon of sand expansion occurs. A second driving mechanism 7 is provided at the input end of the transmission chain 13. The second driving mechanism 7 can be a pneumatic cylinder or a hydraulic cylinder. The driving direction of the second driving mechanism 7 is consistent with the axial direction of the sleeve 2. A push plate 6 is provided at the output end of the second driving mechanism 7. The push plate 6 is correspondingly positioned to the contact plate 5, i.e., the push plate 6 is located on the side of the contact plate 5 closer to the input end of the transmission chain 13. After the second driving mechanism 7 drives the push plate 6 to move towards the sand mold, the surface of the push plate 6 is flush with the surface of the contact plate 5. The function of the second driving mechanism 7 is to push the push plate 6 to move, causing the clamping rod 3 and the pressure plate 4 to move towards the sand mold, thereby causing the pressure plate 4 to contact the side of the sand mold or to press the side of the sand mold. Simultaneously, the push plate 6 also serves as a guide, allowing the clamping rod 3 corresponding to the push plate 6 to move smoothly onto the contact plate 5 under the action of the first conveying mechanism 1.Specifically, before the end of the clamping rod 3 contacts the abutment plate 5, the push plate 6 applies an axial force to the clamping rod 3 under the action of the second drive mechanism 7, so that the pressure plate 4 contacts or presses the side of the sand mold. Then, during the synchronous movement of the first conveying mechanism 1 and the sand mold, the clamping rod 3 corresponding to the push plate 6 can move along the push plate 6 to the position corresponding to the abutment plate 5, so that the pressure plate 4 presses the side of the sand mold under the action of the abutment plate 5. At this time, the second drive mechanism 7 retracts the push plate 6 and pushes it out again, so that the push plate 6 applies an axial force to the next clamping rod 3, so that the clamping rod 3 pushes the pressure plate 4 to press or contact the side of the sand mold.
[0028] The contact plate 5 is parallel to the side of the sand mold on the sand mold conveying system 20 and is located above the transmission chain 13. This allows the contact plate 5 to react with the pressure rod 3 after the end of the pressure rod 3 comes into contact with the contact plate 5, so that the pressure plate 4 applies a certain pressure to the side of the sand mold to achieve the technical effect of preventing sand from swelling.
[0029] The end of the clamping rod 3 is provided with a roller 31. The clamping rod 3 is slidably connected to the abutment plate 5 through the roller 31. By rolling the end of the clamping rod 3 with the abutment plate 5, the friction between the end of the clamping rod 3 and the abutment plate 5 can be reduced, which is beneficial to improving the stability of the pressure applied by the pressure plate 4 to the sand mold.
[0030] A telescopic spring 8 is sleeved on the outside of the clamping rod 3. The telescopic spring 8 is located between the sleeve 2 and the abutment plate 5. During the process of the clamping rod 3 contacting the abutment plate 5 and generating relative sliding, the telescopic spring 8 is in a compressed state. When the clamping rod 3 separates from the abutment plate 5, under the elastic force of the telescopic spring 8 and the limiting action of the first conveying mechanism 1, the clamping rod 3 moves away from the sand mold, thereby causing the pressure plate 4 to separate from the sand mold.
[0031] The inner wall of the sleeve 2 is provided with a groove 21, and the outside of the clamping rod 3 is provided with a protrusion 32 that cooperates with the groove 21. The length direction of the groove 21 is consistent with the axial direction of the sleeve 2. By cooperating with the groove 21 and the protrusion 32, the clamping rod 3 can be prevented from rotating inside the sleeve 2, thereby ensuring that the pressure plate 4 is prevented from rotating during the movement of the first conveying mechanism 1, which is beneficial to ensuring the stability of the pressure plate 4 applying pressure to the sand mold.
[0032] The surface of the pressure plate 4 is provided with anti-slip texture, such as anti-slip texture or protrusion, which can increase the friction between the sand mold and the pressure plate 4 and improve the anti-sand swelling effect.
[0033] The first conveying mechanism 1 includes two sets of parallel transmission chains 13. The two ends of the sleeve 2 are fixedly connected to the two sets of transmission chains 13. During the contact between the pressure plate 4 and the sand mold, the two ends of the sleeve 2 are fixed by the two parallel transmission chains 13, which helps to ensure the perpendicularity of the sleeve 2, the pressing rod 3 and the side of the sand mold, thereby helping to ensure the uniformity and stability of the pressure of the pressure plate 4 on the sand mold.
[0034] The surface of the contact plate 5 simultaneously contacts at least two sets of clamping rods 3, thereby forming three sets of pressure plates 4 to press the sides of the sand mold in conjunction with the second drive mechanism 7 and the push plate 6. Specifically, along the sand mold moving direction, under the action of the second drive mechanism 7 and the push plate 6, the sand mold at the front end of the pouring position (the unpoured sand mold) is pressed, and under the action of the contact plate 5, the pressure plates 4 press the sand mold at the pouring position and the sand mold after pouring. This can press the sand mold at the pouring position and before and after the pouring position, effectively preventing the sand mold from shifting due to the pressure generated by the injection of molten iron during the pouring process. The pressure plates 4 before and after the pouring position mainly serve to fix the sand mold in the corresponding area. By stabilizing the sand mold before and after the pouring position, the constraint effect on the sand mold in the pouring section is enhanced, thereby effectively preventing the occurrence of sand expansion.
[0035] The length of the pressure plate 4 is greater than the thickness of the sand mold. On the one hand, it is convenient for one pressure plate 4 to press two adjacent sand molds at the same time. On the other hand, it is convenient to increase the contact area between the pressure plate 4 and the sand mold, thereby increasing the friction between the pressure plate 4 and the sand mold.
[0036] The sleeve 2 is provided with adjusting rods 9 and adjusting blocks 10 that can slide in contact with the adjusting rods 9 at both ends. The adjusting rods 9 are smooth cylindrical structures. The side of the adjusting block 10 that contacts the adjusting rod 9 is perpendicular to the axis of the sleeve 2. The adjusting block 10 is connected to the sleeve 2 and slides in contact with the inner side of the adjusting rod 9. The axis of the adjusting rod 9 is consistent with the conveying direction of the transmission chain 13. That is, during the process of the clamping rod 3 and the pressure plate 4 contacting each other to generate a certain pressure on the sand mold, the adjusting blocks 10 at both ends of the sleeve 2 form a line contact with the adjusting rod 9, which reduces the friction between the adjusting rod 9 and the adjusting block 10, and also restricts the sleeve 2, compensates for the conveying defects of the transmission chain 13, and ensures the perpendicularity of the axis of the sleeve 2 to the side of the sand mold being pressed during the movement of the sleeve 2 by the transmission chain 13, thereby ensuring uniform force on both sides of the sand mold and improving the anti-sand swelling effect.
[0037] The working principle of this invention is as follows: A sleeve 2, a clamping rod 3, a pressure plate 4, and a contact plate 5 are arranged on both sides of the sand mold conveying system 20 to form a clamping mechanism, thereby applying a certain pressure to both sides of the sand mold simultaneously to avoid sand expansion during the pouring process. Specifically, the transmission chain 13 is driven to rotate by the first driving device, which drives the sleeve 2 to move synchronously. When the sleeve 2 moves to the position of the contact plate 5, under the restriction of the contact plate 5, one end of the clamping rod 3 abuts against the contact plate 5, and the pressure plate 4 at the other end clamps the side of the sand mold, thereby generating a certain pressure on the sand mold. At the same time, under the action of the second driving mechanism 7 and the push plate 6, the clamping rod 3 corresponding to the push plate 6 acts on the pressure plate 4, so that the pressure plate 4 at this point generates moving pressure on the sand mold, and friction is generated between the sand mold and the pressure plate 4. During pouring, the friction can prevent sand expansion from occurring in the sand mold, thus affecting the quality of the casting. After the pouring is completed at the pouring position, the sand mold conveying system moves forward, transporting the sand mold. At this time, the clamping mechanism corresponding to the push plate 6 moves to the position corresponding to the contact plate 5 under the guidance of the push plate 6. The push plate 6 reciprocates under the action of the second drive mechanism 7, pushing the next clamping mechanism to repeat the above operation. The clamping mechanism at the end of the contact plate 5 separates from the sand mold under the action of the telescopic spring 8. This cycle is repeated to realize the process of the pressure plate 4 clamping the sand mold, moving synchronously with the sand mold, and then separating from the sand mold.
[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.
Claims
1. A sand-expansion prevention system for sand casting without a sandbox, characterized in that: The system includes a first conveying mechanism (1) located on both sides of the sand mold conveying system (20). The first conveying mechanism (1) includes a driving wheel (11), a driven wheel (12), and a transmission chain (13). The driving wheel (11) is connected to a first driving device that drives the driving wheel (11) to rotate. The transmission chain (13) is provided with a plurality of sleeves (2). The axial direction of the sleeves (2) is perpendicular to the movement direction of the transmission chain (13). A clamping rod (3) is slidably connected inside the sleeve (2) and close to the sand. At one end of the sand mold conveying system (20), the clamping rod (3) is provided with a pressure plate (4), and at the other end is provided with an abutment plate (5) that can contact the clamping rod (3). After one end of the clamping rod (3) contacts the abutment plate (5), the pressure plate (4) clamps the sand mold on the sand mold conveying system (20). The input end of the transmission chain (13) is provided with a push plate (6), and the push plate (6) is provided with a second drive mechanism (7) that drives the push plate (6) to reciprocate along the axial direction of the clamping rod (3).
2. The anti-expansion sand system for sand casting without a sandbox according to claim 1, characterized in that: The contact plate (5) is parallel to the side of the sand mold on the sand mold conveying system (20) and is located above the transmission chain (13).
3. The anti-expansion sand system for sand casting without a sandbox according to claim 1, characterized in that: The end of the clamping rod (3) is provided with a roller (31), and the clamping rod (3) is slidably connected to the contact plate (5) through the roller (31).
4. The anti-expansion sand system for sand casting without a sandbox according to claim 1, characterized in that: The clamping rod (3) is fitted with a telescopic spring (8), which is located between the sleeve (2) and the abutment plate (5).
5. The anti-expansion sand system for sand casting without a sandbox according to claim 1, characterized in that: The inner wall of the sleeve (2) is provided with a groove (21), and the outside of the clamping rod (3) is provided with a protrusion (32) that cooperates with the groove (21). The length direction of the groove (21) is consistent with the axial direction of the sleeve (2).
6. The anti-expansion sand system for sand casting without a sandbox according to claim 1, characterized in that: The surface of the pressure plate (4) is provided with anti-slip texture.
7. The anti-expansion sand casting system for sand-box-less casting according to claim 1, characterized in that: The first conveying mechanism (1) includes two sets of parallel transmission chains (13), and the two ends of the sleeve (2) are fixedly connected to the two sets of transmission chains (13).
8. The anti-expansion sand casting system for sand-box-less casting according to claim 1, characterized in that: The surface of the contact plate (5) is in contact with at least two sets of the clamping rods (3) simultaneously.
9. The anti-expansion sand system for sand casting without a sandbox according to claim 1, characterized in that: The length of the pressure plate (4) is greater than the thickness of the sand mold.
10. The anti-expansion sand system for sand casting without a sandbox according to claim 1, characterized in that: The sleeve (2) is provided with adjusting rods (9) and adjusting blocks (10) that can slide in contact with the adjusting rods (9) at both ends. The adjusting blocks (10) are connected to the sleeve (2). The side of the adjusting block (10) that contacts the adjusting rod (9) is perpendicular to the sleeve (2). The axis of the adjusting rod (9) is consistent with the conveying direction of the transmission chain (13).