An inflatable mandrel

Abstract

The application discloses an expansion mandrel and relates to the technical field of cutting processing, which comprises a core rod, one end of the core rod is provided with an adjusting seat, the surface of one side of the adjusting seat is provided with an adjusting nut, the surface of the core rod is provided with a plurality of second anchor screws, one end of the core rod is provided with a fixing mechanism, the fixing mechanism comprises a main rod assembly, the main rod assembly comprises a tungsten steel sleeve, the tungsten steel sleeve is arranged at one end of the core rod, the end of the tungsten steel sleeve, which is away from the core rod, is provided with a front sleeve, the surface of the front sleeve is provided with a plurality of first anchor screws, the inside of the core rod and the front sleeve is in communication, the inside of the core rod is provided with a pull rod, one end of the pull rod is provided with a top head, the surface of the pull rod is further provided with an internal spring, the end of the adjusting nut, which is away from the top head, is provided with an expansion head, in the scheme, the fixing mechanism is arranged, the workpiece is uniformly and stably fixed by internal support, effective cooling and buffering are achieved, and the machining quality and efficiency are comprehensively improved.

Description

Technical Field

[0001] This invention relates to the field of cutting and machining technology, specifically to an expansion mandrel. Background Technology

[0002] In the field of metal product processing, edge trimming of cylindrical workpieces (such as stainless steel thermos cups, automobile wheel hubs, pressure tanks, etc.) is an indispensable key step in ensuring product forming quality and processing accuracy. When the edge trimming machine is running, it relies on an expansion mandrel to reliably support the workpiece from the inside and drive the workpiece to achieve precise rotation, thereby successfully completing the edge trimming operation. Currently, most expansion mandrels on the market adopt a wedge mechanical structure. Its working principle is based on a precise mechanical transmission mechanism. Multiple expansion flaps expand outward simultaneously, gradually fitting tightly against the inner wall of the workpiece. As the expansion force of the expansion flaps increases, the workpiece is finally firmly supported and fixed from the inside, ensuring that the workpiece remains stable when the edge trimming machine rotates. This provides a solid foundation for subsequent precise edge trimming operations. This wedge mechanical structure has been widely used in the metal product processing industry due to its mature technology and relatively stable performance.

[0003] Existing technologies still have some drawbacks. The expansion structure used in traditional expansion mandrels has certain limitations in design and practical application. It typically relies on simple mechanical expansion, making it difficult to precisely control the force applied to different parts of the workpiece's inner wall. Due to uneven force distribution, the workpiece cannot achieve comprehensive and uniform stable support during fixation. In subsequent processing, this uneven force state can cause a series of problems. Taking the edge trimming process as an example, when the edge trimming machine's blade cuts the workpiece, the workpiece, due to its insecure fixation, will undergo microscopic deformation under the force of the blade. This deformation affects the workpiece's position during the cutting process. Even slight misalignment can lead to uneven and inconsistent cutting edges. Uneven cutting edges directly affect the product's appearance, causing burrs and unevenness on the surface, thus reducing the product's aesthetic appeal. Furthermore, existing technologies have serious deficiencies in cooling and protection. During metal processing, the high-speed friction between the tool and the workpiece generates a large amount of heat. If this heat cannot be dissipated in time, it will damage the workpiece and processing equipment. For the workpiece, high temperatures can alter its internal metal structure, reducing the material's strength and toughness, making the workpiece prone to breakage and deformation during subsequent use, thus affecting the product's reliability and service life. Summary of the Invention

[0004] The purpose of this invention is to provide an expansion mandrel to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an expansion mandrel, comprising:

[0006] A mandrel, one end of which is provided with an adjusting seat, one side surface of which is provided with an adjusting nut, and the surface of which is provided with a plurality of second anchoring screws, and the other end of which is provided with a fixing mechanism, the fixing mechanism including a main rod assembly, the main rod assembly including: a tungsten steel sleeve, the tungsten steel sleeve being provided at one end of the mandrel, the end of which facing away from the mandrel being provided with a front sleeve, the surface of which is provided with a plurality of first anchoring screws, the mandrel and the front sleeve being internally connected, and the mandrel being internally provided with a pull rod, one end of which is provided with a top head;

[0007] Furthermore, the surface of the pull rod is also fitted with an internal spring, and an expansion head is provided at the end of the pull rod away from the top head. The expansion head is located at the center of one end of the front sleeve. The surface of the pull rod is also fitted with a connecting sleeve, and multiple expansion sleeves are provided on the side surface of the connecting sleeve. Multiple openings are provided on the side surface of the front sleeve to facilitate the exposure of the expansion sleeves.

[0008] Furthermore, an internal filling cavity is provided at the center of the connecting sleeve, and a connecting inner cylinder is provided inside the internal filling cavity. The connecting inner cylinder is also sleeved on the surface of the pull rod. Multiple top contact inner rods are provided on the side surface of the connecting inner cylinder, and each top contact inner rod corresponds to an expansion sleeve.

[0009] Furthermore, the fixing mechanism also includes an additional component, which includes a water ring component and a buffer component. The water ring component includes: a secondary protective cover, which is sleeved on one end surface of the mandrel, and the surface of the secondary protective cover has multiple small openings. A main protective cover that cooperates with the secondary protective cover is sleeved on one end surface of the front sleeve.

[0010] Furthermore, a water storage sleeve is also fitted on the surface of the front sleeve. The water storage sleeve has a hollow structure and is filled with cooling water. The upper surface of the water storage sleeve is provided with an injection port for filling its interior. An annular pressure plate is also provided inside the water storage sleeve.

[0011] Furthermore, a small telescopic motor for driving the annular pressure plate to move is provided on the side surface of the water storage sleeve. Multiple infusion branch pipes are provided between the water storage sleeve and the main protective cover. One end of each infusion branch pipe is provided with a nozzle, and a one-way diaphragm valve is provided inside the nozzle.

[0012] Furthermore, the buffer component includes: a fixing ring, which is sleeved on the surface of the front sleeve, and a plurality of adsorption pads are provided on one side surface of the fixing ring. Each adsorption pad corresponds to an expansion sleeve. An air cavity is opened inside the adsorption pad, and a one-way diaphragm valve and an air outlet are respectively provided at both ends of the adsorption pad.

[0013] Furthermore, connecting side rods are respectively provided on both sides of the adsorption pad. One end of the connecting side rod is connected to one side surface of the fixing ring. A slidable sealing sliding ring is also provided on the surface of the connecting side rod. Multiple return springs are also provided between the fixing ring and the sealing sliding ring.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. In this solution, a main rod assembly is provided, and the pull rod is driven to move axially through the built-in compression spring. This allows the rear expansion head to engage with the front expansion sleeve and the conical surface at the tail of the front sleeve, achieving uniform radial expansion of the multi-layer alloy steel elastic expansion sleeve. A composite structure of high-strength alloy steel substrate and tungsten carbide coating is adopted, which not only ensures the rigidity of the expansion sleeve, but also significantly improves the wear resistance through the hard alloy contact surface. This solves the problem of decreased positioning accuracy caused by inconsistent wear of traditional expansion flaps. At the same time, the spring drive system is in a pressure-holding state after expansion, which reduces relative motion wear and extends service life.

[0016] 2. In this solution, by setting up a water ring component, a small telescopic motor drives an annular pressure plate to precisely spray the cooling water in the water storage sleeve onto the surface of the tungsten steel sleeve through the liquid delivery branch pipe, thereby achieving pre-cooling and cooling before cutting. The main protective cover and the secondary protective cover not only reduce the diffusion of cutting chips, but also work together with the water spray system to effectively reduce the heat accumulation in the cutting area, improve processing accuracy and tool life, and are especially suitable for continuous edge cutting operations in high-temperature environments.

[0017] 3. In this solution, by setting up a buffer component, negative pressure is generated by venting air through the air chamber inside the adsorption pad, which realizes secondary adsorption and fixation of the inner surface of the workpiece. When the expansion sleeve expands outward, the adsorption pad is pressed tightly against the inner surface of the workpiece. While venting air, mist cooling water is drawn in through a one-way diaphragm valve, which not only enhances the fixing effect and prevents processing shaking, but also reduces thermal deformation through water vapor cooling, significantly improving processing stability and product quality. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the main rod assembly structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the internal structure of the main rod assembly of the present invention;

[0021] Figure 4 This is a schematic diagram of the tie rod and connecting inner cylinder structure of the present invention;

[0022] Figure 5 This is a schematic diagram of the connecting sleeve structure of the present invention;

[0023] Figure 6 This is a schematic diagram of the buffer component structure of the present invention;

[0024] Figure 7 This is a schematic diagram of the internal structure of the adsorption pad of the present invention;

[0025] Figure 8 This is a schematic diagram of the water ring component structure of the present invention.

[0026] In the diagram: 1. Core rod; 2. Tungsten steel sleeve; 3. Front sleeve; 4. Expansion sleeve; 5. Expansion head; 6. Pull rod; 7. First anchoring screw; 8. Second anchoring screw; 9. Internal spring; 10. Adjusting nut; 11. Adjusting seat; 12. Top head; 13. Connecting sleeve; 14. Top contact inner rod; 15. Water storage sleeve; 16. Main protective cover; 17. Secondary protective cover; 18. Adsorption pad; 19. Connecting inner cylinder; 20. Internal filling cavity; 21. Sealing sliding ring; 22. Fixing ring; 23. Connecting side rod; 24. Return spring; 25. Air chamber; 26. One-way diaphragm valve; 27. Air outlet; 28. Small telescopic motor; 29. ​​Injection port; 30. Infusion branch pipe; 31. Small opening. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1: Please refer to Figures 1 to 8 An expansion mandrel, comprising:

[0029] The mandrel 1, serving as the supporting frame of the entire device, possesses high strength and rigidity, capable of withstanding various external forces generated during processing. One end of the mandrel 1 is equipped with an adjusting seat 11, with an adjusting nut 10 on one side surface. Multiple second anchoring screws 8 are located on the surface of the mandrel 1. The other end of the mandrel 1 is equipped with a fixing mechanism, a crucial component for securing the workpiece in the expansion mandrel. The fixing mechanism includes a main rod assembly and auxiliary components. The main rod assembly includes a tungsten carbide sleeve 2, which possesses extremely high hardness and wear resistance, enabling it to maintain a long service life even in harsh processing environments and effectively resisting the erosion of cutting forces and friction. The tungsten carbide sleeve 2 is located at one end of the mandrel 1. A front sleeve 3 is located at the end of the tungsten carbide sleeve 2 facing away from the mandrel 1, with multiple first anchoring screws 7 on its surface. The mandrel 1 and the front sleeve 3 are internally connected, forming a smooth channel that provides space for the movement of internal components. A pull rod 6 is located inside the mandrel 1, with a top head 12 at one end. When the pull rod 6 is subjected to external force, the top head 12 can accurately transmit the force. An internal spring 9 is also fitted on the surface of the pull rod 6. An expansion head 5 is provided at the end of the pull rod 6 away from the top head 12. The expansion head 5 is located at the center of one end of the front sleeve 3. The expansion head 5 is a key expansion component. A connecting sleeve 13 is also fitted on the surface of the pull rod 6. Multiple expansion sleeves 4 are provided on the side surface of the connecting sleeve 13. Multiple openings are opened on the side surface of the front sleeve 3 to facilitate the exposure of the expansion sleeves 4, so that the expansion sleeves 4 can be smoothly extended when needed. The outer expansion sleeve 13 has an internal filling cavity 20 at its center. The inner filling cavity 20 is provided with a connecting inner cylinder 19, which is also sleeved on the surface of the pull rod 6. The side surface of the connecting inner cylinder 19 is provided with multiple top contact inner rods 14, each of which corresponds to an expansion sleeve 4. When the pull rod 6 moves, the top head 12 pushes the connecting inner cylinder 19, which in turn causes the top contact inner rods 14 to push the expansion sleeve 4, thereby expanding the expansion sleeve 4 outward and thus fixing it tightly from the inside of the workpiece.

[0030] In this design, the mandrel 1 integrates a spring-driven pneumatic system, with the built-in compression spring 9 as its core. During use, the user first places the workpiece on the outer surface of the mandrel 1. Then, the user controls the expansion by axially moving the pull rod 6. When the pull rod 6 is pushed by an external force, its top head 12 presses against the inner cylinder 19, causing the inner rod 14 to slide along the inclined plane and expand outwards. Simultaneously, the rear expansion head 5 moves axially under the influence of the pull rod 6, its conical surface tightly fitting against the conical surfaces of the front expansion sleeve 4 and the tail of the front sleeve 3, converting the axial force into a radial component force. This drives the multi-layer alloy steel elastic expansion sleeve to expand uniformly. The front expansion sleeve 4 and the tail of the front sleeve 3 adopt a multi-layer composite structure, with a high-strength alloy base. The outer layer of the steel sleeve is coated with tungsten carbide to form a wear-resistant layer. When the rear expansion head 5 moves axially, its conical surface matches the tapered inner wall of the expansion sleeve, causing the expansion sleeve to expand radially. The hard alloy contact surface can withstand high-intensity friction without wear, fixing the workpiece from the inside for subsequent processing. When cutting, the rotary cutting blade of the edge trimmer is located within the area of ​​the tungsten steel sleeve 2 surface to trim the aluminum can, ensuring that the aluminum can reaches the required length. Therefore, the sleeve here is made of high-hardness tungsten steel. After the processing is completed, when the user releases the external force pushing the pull rod 6, the internal spring 9 can reset the expansion head 5 through elastic restoring force during unloading, and the expansion sleeve contracts, realizing the quick loading and unloading of the workpiece.

[0031] The additional components include a water ring assembly and a buffer assembly. The water ring assembly provides effective cooling and protection during machining. It includes a secondary protective cover 17, which is fitted onto one end of the mandrel 1. The secondary protective cover 17 has multiple small openings 31 on its surface. A primary protective cover 16, which mates with the secondary protective cover 17, is fitted onto one end of the front sleeve 3. Together, they form a relatively enclosed protective space. A water-retaining sleeve 15 is also fitted onto the surface of the front sleeve 3. This water-retaining sleeve 15 is hollow and filled with cooling water. The cooling water plays a crucial role in the machining process, absorbing the large amount of heat generated in the machining area and reducing the temperature of the workpiece and cutting tool. To prevent workpiece deformation and accelerated tool wear caused by overheating, the upper surface of the water storage sleeve 15 is provided with a liquid injection port 29 for filling its interior. Operators can easily add cooling water to the water storage sleeve 15 to ensure that the cooling water is always sufficient during long-term processing. The interior of the water storage sleeve 15 is also provided with an annular pressure plate. The side surface of the water storage sleeve 15 is provided with a small telescopic motor 28 for driving the annular pressure plate to move. The small telescopic motor 28 can accurately control the moving speed and position of the annular pressure plate according to processing requirements. Multiple liquid delivery branches 30 are provided between the water storage sleeve 15 and the main protective cover 16. One end of the liquid delivery branch 30 is provided with a nozzle, and the nozzle is provided with a one-way diaphragm valve.

[0032] The additional components work together through the combination of water ring components and buffer components to improve the fixation effect of the main rod assembly on the workpiece. During use, when the workpiece is fixed, the multiple expansion sleeves 4 of the main rod assembly expand outward to fix the workpiece from the inner side surface. When the workpiece is fixed, the small telescopic motor 28 on the side surface of the water storage sleeve 15 is started once under the signal drive of the user. It extends through its output shaft to push the annular pressure plate inside the water storage sleeve 15. The annular pressure plate forces the cooling water inside the water storage sleeve 15 out and sprays it from multiple liquid delivery branches 30 onto the surface of the tungsten steel sleeve 2 for pre-cooling. This reduces the heat of the cutting environment in the subsequent cutting process. The main protective cover 16 and the secondary protective cover 17 can reduce the shielding effect on both sides of the cutting work area during the cutting process and reduce the diffusion range of the generated flying chips.

[0033] The buffer component includes: a fixing ring 22, which is sleeved on the surface of the front sleeve 3. A plurality of adsorption pads 18 are provided on one side surface of the fixing ring 22. Each adsorption pad 18 corresponds to an expansion sleeve 4. An air cavity 25 is opened inside the adsorption pad 18. The air cavity 25 is the key area for the entire buffer component to achieve the adsorption function. When the adsorption pad 18 contacts the inner surface of the workpiece, the air in the air cavity 25 is discharged, generating negative pressure, thereby forming a strong adsorption force, which tightly adsorbs the workpiece onto the adsorption pad 18. One-way diaphragm valves 26 and air outlets 27 are respectively provided at both ends of the adsorption pad 18. Connecting side rods 23 are respectively provided on both sides of the adsorption pad 18. One end of the connecting side rod 23 is connected to one side surface of the fixing ring 22. A slidable sealing sliding ring 21 is also provided on the surface of the connecting side rod 23. A plurality of return springs 24 are also provided between the fixing ring 22 and the sealing sliding ring 21.

[0034] The buffer component provides a buffering effect between the workpiece and the expansion sleeve 4 during workpiece fixing. Under normal conditions, the sealing sliding ring 21 remains in contact with one side surface of the adsorption pad 18 under the action of the return spring 24, sealing the air outlet 27 on the side surface of the adsorption pad 18. During the workpiece fixing process, the multiple expansion sleeves 4 expand outwards, pushing the adsorption pad 18 on their surfaces outwards and pressing it against the inner surface of the workpiece. During this process, air in the air chamber 25 inside the adsorption pad 18 will escape from the outlet... Air is discharged through port 27, and the sealing sliding ring 21 is pushed outward to exhaust air, creating negative pressure inside the air chamber 25. The air is then adsorbed onto the inner surface of the workpiece by the adsorption pad 18 for further fixation, preventing the workpiece from shaking during processing. During the exhaust process of the air chamber 25, a certain amount of external air is drawn in through the one-way diaphragm valve 26. At this time, the mist-like cooling water discharged through the water ring component is drawn into the air chamber 25. When the adsorption pad 18 comes into contact with the inner surface of the workpiece, it can produce a certain cooling effect.

[0035] The working principle of this invention is:

[0036] When the equipment is working, the user first puts the workpiece on the outer surface of the mandrel 1 and controls the expansion action by moving the pull rod 6 axially. When the pull rod 6 is pushed by an external force, the top head 12 squeezes the inner cylinder 19, causing the top contact inner rod 14 to slide along the inclined plane and expand outward. At the same time, the rear expansion head 5 moves axially under the drive of the pull rod 6. Its conical surface is closely fitted with the conical surface of the front expansion sleeve 4 and the tail of the front sleeve 3, converting the axial force into a radial component force, driving the multi-layer alloy steel elastic expansion sleeve to expand evenly. The hard alloy contact surface can withstand high-intensity friction without wear, realizing the internal fixation of the workpiece. When cutting the edge, the rotary cutting blade of the edge cutting machine cuts the aluminum can within the surface range of the tungsten steel sleeve 2. The tungsten steel sleeve 2 is made of high-hardness tungsten steel to ensure the cutting accuracy. After the processing is completed, the external force pushing the pull rod 6 is removed, and the internal spring 9 resets the expansion head 5 through the elastic restoring force, and the expansion sleeve contracts, realizing the quick loading and unloading of the workpiece.

[0037] In the additional components, when the water ring component is working, the small telescopic motor 28 drives the annular pressure plate to spray the cooling water in the water storage sleeve 15 through the liquid delivery branch pipe 30 to pre-cool the surface of the tungsten steel sleeve 2 and reduce the cutting heat. The main protective cover 16 and the secondary protective cover 17 block flying chips. When the buffer component is working, the expansion sleeve 4 expands outward and pushes the adsorption pad 18. The air in the air chamber 25 is discharged from the air outlet 27 and generates negative pressure, so that the adsorption pad 18 is adsorbed on the inner surface of the workpiece, further fixing the workpiece. The atomized cooling water drawn in can also cool down the workpiece.

[0038] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An expansion mandrel characterized by, The utility model relates to a core rod, one end of the core rod is provided with an adjusting seat, one side surface of the adjusting seat is provided with an adjusting nut, the surface of the core rod is provided with a plurality of second anchor screws, the other end of the core rod is provided with a fixing mechanism, the fixing mechanism comprises a main rod assembly, the main rod assembly comprises a tungsten steel sleeve, the tungsten steel sleeve is arranged at one end of the core rod, the one end of the tungsten steel sleeve away from the core rod is provided with a front sleeve, the surface of the front sleeve is provided with a plurality of first anchor screws, the inside of the core rod and the front sleeve is communicated, the inside of the core rod is provided with a pull rod, one end of the pull rod is provided with a top head, the fixing mechanism further comprises an additional assembly, the additional assembly comprises a water ring part and a buffer part, the water ring part comprises a vice protective cover, the vice protective cover is sleeved on the surface of one end of the core rod, a plurality of small openings are formed in the surface of the vice protective cover, a main protective cover matched with the vice protective cover is sleeved on the surface of one end of the front sleeve, the surface of the pull rod is further sleeved with an internal spring, one end of the pull rod away from the top head is provided with an expansion head, the expansion head is located at the center of one end of the front sleeve, the surface of the pull rod is further sleeved with a connecting sleeve, a plurality of expansion sleeves are arranged on the side surface of the connecting sleeve, a plurality of openings are formed in the side surface of the front sleeve to expose the expansion sleeves, an internal filling cavity is formed in the center of the connecting sleeve, a connecting inner cylinder is arranged in the internal filling cavity, the connecting inner cylinder is also sleeved on the surface of the pull rod, a plurality of top touch inner rods are arranged on the side surface of the connecting inner cylinder, each top touch inner rod corresponds to one expansion sleeve. the surface of the front sleeve is further sleeved with a water storage sleeve, the water storage sleeve is a hollow structure, the water storage sleeve is filled with cooling water, an injection port is arranged on the upper surface of the water storage sleeve to fill the cooling water, an annular water pressing plate is further arranged in the water storage sleeve.

2. An inflatable mandrel according to claim 1, wherein: a small telescopic motor is arranged on the side surface of the water storage sleeve to drive the annular water pressing plate to move, a plurality of infusion branch pipes are arranged between the water storage sleeve and the main protective cover, a spray port is formed in one end of the infusion branch pipe, a one-way membrane valve is arranged in the spray port.

3. An inflatable mandrel according to claim 2, wherein: the buffer part comprises a fixing ring, the fixing ring is sleeved on the surface of the front sleeve, a plurality of adsorption pads are arranged on one side surface of the fixing ring, each adsorption pad corresponds to one expansion sleeve, a gas cavity is formed in the adsorption pad, a one-way diaphragm valve and an air outlet are arranged at two ends of the adsorption pad.

4. An inflatable mandrel according to claim 3, wherein: connecting side rods are arranged on the two side surfaces of the adsorption pad, one end of the connecting side rod is connected with one side surface of the fixing ring, a slidable sealing sliding ring is further arranged on the surface of the connecting side rod, a plurality of reset springs are further arranged between the fixing ring and the sealing sliding ring.

5. An inflatable mandrel according to claim 4, wherein: ​

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