Auxiliary clamping tool for expanding the taper of a long thin-walled pipe

Abstract

The utility model provides a kind of thin-walled long tube expansion cone auxiliary clamping tool, including sleeve for clamping on machine tool and adapting insertion thin-walled long tube, the first end of sleeve is provided with sleeve cover, the first end port inner circle edge of sleeve is right angle edge, the second end port inner circle of sleeve is provided with chamfer for adapting thin-walled long tube expansion cone, the length of sleeve is shorter than the length of thin-walled long tube 1mm~3mm.The utility model can be positioned to thin-walled long tube when thin-walled long tube expansion cone, it is convenient to clamp on machine tool, play auxiliary clamping effect, strengthen thin-walled long tube strength simultaneously, prevent thin-walled long tube bending deformation, avoid thin-walled long tube expansion cone not in place or excessive, improve thin-walled long tube expansion cone quality.

Description

Technical Field

[0001] This utility model relates to the field of metal pipe end processing technology, specifically to an auxiliary clamping tool for expanding the conical end of a thin-walled long pipe. Background Technology

[0002] Thin-walled long tubes (made of metal) are widely used in aerospace, precision instruments, and tobacco machinery industries due to their lightweight and material-saving characteristics. These parts often require a tapered opening at one end to meet functional requirements such as connection and sealing. However, due to the inherent poor rigidity and susceptibility to deformation of thin-walled long tubes, the machining of this tapered opening has always been a challenge in the manufacturing process.

[0003] Currently, the mainstream methods for expanding tapered edges mainly include hot stamping, cold stamping (cold heading), and spinning, but these methods all have obvious limitations.

[0004] Hot stamping: While it can reduce forming force, it requires a complex mold cooling system and automated loading and unloading mechanism to prevent the risks of manual operation, resulting in high equipment investment costs. Furthermore, localized induction heating of thin-walled parts is inefficient, with high energy loss and poor economic performance, making it only suitable for mass production.

[0005] Cold stamping (cold heading) method: This method uses a specialized flaring machine to directly apply pressure to the pipe end. The equipment required is large-tonnage, energy-intensive, and structurally bulky. The process is also time-consuming and labor-intensive, making it only suitable for mass production. More importantly, under large flaring ratios, the pipe material is prone to rough tapered surfaces, poor roundness, and incorrect taper angles due to severe plastic deformation, potentially leading to significant wall thinning or cracking, making it difficult to guarantee processing quality.

[0006] Spinning method: The pipe end is extruded by a high-speed rotating die to form a tapered opening. Because the die is rotating at high speed while extruding, high temperature and pressure are generated between the die and the pipe, which causes greater wear on the die, resulting in a shorter die life, higher processing cost, and a tendency for "bottom instability" to occur, which seriously affects the product qualification rate and reliability.

[0007] The applicant belongs to the tobacco machinery industry, which has a relatively small demand for thin-walled long tubes, typically requiring only small-batch production. Therefore, in actual production of thin-walled long tubes, we usually use a spinning method, where the thin-walled long tube is directly clamped on a machine tool, and a high-speed rotating die is used to extrude the end of the thin-walled long tube to form a tapered opening. However, this method causes severe wear on the die, requiring frequent die replacements, resulting in high costs. It also easily leads to bending and deformation of the thin-walled long tube, and inadequate or excessive tapering, thus affecting the quality of the tapered opening of the thin-walled long tube.

[0008] To reduce processing costs and improve processing quality, we have studied the processing method of expanding the conical opening of thin-walled long tubes based on our own experience, and designed an auxiliary clamping fixture for expanding the conical opening of thin-walled long tubes. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of existing technologies by providing an auxiliary clamping fixture for expanding the conical opening of thin-walled long tubes. This invention facilitates the clamping and positioning of thin-walled long tubes on machine tools during the expansion of their conical openings, thus providing an auxiliary clamping function. At the same time, it enhances the strength of the thin-walled long tubes, prevents them from bending and deforming, avoids incomplete or excessive expansion of the conical opening, and improves the quality of the expansion of the conical opening of thin-walled long tubes.

[0010] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a thin-walled long tube expansion tapering auxiliary clamping fixture, including a sleeve for clamping on a machine tool and adapting to the insertion of a thin-walled long tube, a sleeve cap is provided at the first end of the sleeve, the inner circle edge of the first end port of the sleeve is a right-angle edge, the inner circle of the second end port of the sleeve is provided with a chamfer for adapting to the expansion tapering of the thin-walled long tube, and the length of the sleeve is 1mm to 3mm shorter than the length of the thin-walled long tube.

[0011] Beneficial effects: In the process of expanding the tapered opening of a thin-walled long tube, this utility model clamps a sleeve on a machine tool, inserts the thin-walled long tube into the sleeve, with one end of the tube abutting against the sleeve cover and the other end positioned at the second end port of the sleeve, extending 1mm to 3mm beyond the sleeve. This positioning of the thin-walled long tube replaces the existing method of directly clamping the workpiece, providing auxiliary clamping. Simultaneously, because the thin-walled long tube is inserted into the sleeve, and the inner circle of the second end port of the sleeve has a chamfer to accommodate the tapered opening of the thin-walled long tube, the opening of the thin-walled long tube can be directly stamped using a mold, forming a tapered opening that fits the chamfer. This avoids incomplete or excessive tapering of the thin-walled long tube, improving the quality of the tapered opening. Furthermore, during this process, the sleeve can withstand the pressure of the thin-walled long tube under pressure deformation, enhancing its strength and preventing bending deformation.

[0012] Furthermore, when using this tooling, the mold does not need to rotate to extrude the workpiece, resulting in less wear on the mold, which can improve the mold's service life, reduce mold replacement costs, simplify the processing of thin-walled long tubes with tapered openings, and improve processing efficiency. It is especially suitable for small-batch production.

[0013] Furthermore, the inner edge of the first end of the sleeve is a right-angle edge. Therefore, during the processing, there is no deformation space at the end of the thin-walled long tube that abuts against the sleeve cover, ensuring that the thin-walled long tube meets the processing requirements.

[0014] Based on the above, the outer circumference of the first end of the sleeve is provided with an external thread, and the inner circumference of the sleeve cover is provided with an internal thread that matches the external thread.

[0015] Beneficial effects: The sleeve cap and sleeve are connected by external and internal threads, making it easy to install and remove the sleeve cap.

[0016] Based on the above, a locking nut that is in tight contact with the sleeve cover port is also threaded onto the outer circumference of the first end of the sleeve.

[0017] Beneficial effect: Tightening the lock nut can lock the sleeve cap and prevent it from loosening.

[0018] Based on the above, the outer circle of the sleeve is provided with an annular groove to facilitate the machine tool to fix, clamp and position it.

[0019] Based on the above, the outer circumference of the sleeve cap is provided with an off-center opening, which facilitates the disassembly and assembly of the sleeve cap using a wrench or other tools.

[0020] Based on the above, the sleeve and the thin-walled long tube are fitted with a clearance and the fit tolerance is 0.1mm to 1mm.

[0021] Beneficial effects: The clearance fit design facilitates the insertion of thin-walled long tubes into the sleeve and prevents bending and deformation of thin-walled long tubes when the tapered opening is expanded. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of a thin-walled long tube that has been processed and formed.

[0023] Figure 2 This is a schematic diagram of the auxiliary clamping fixture for expanding the conical opening of a thin-walled long tube and the assembly structure of the thin-walled long tube parts provided by this utility model.

[0024] Figure 3 yes Figure 2 A cross-sectional structural diagram.

[0025] Figure 4 This is a schematic diagram of the sleeve structure of this utility model.

[0026] Figure 5 This is a schematic diagram of the sleeve cap of this utility model.

[0027] Figure 6 This is a cross-sectional structural diagram of the sleeve cap of this utility model.

[0028] In the diagram: 1. Conical opening; 2. Sleeve cap; 3. Locking nut; 4. Sleeve; 5. Thin-walled long tube; 6. Right-angled edge; 7. Annular groove; 8. Chamfer; 9. Flat opening. Detailed Implementation

[0029] The technical solution of this utility model will be further described in detail below through specific embodiments.

[0030] This embodiment provides an auxiliary clamping fixture for thin-walled long tubes with expanded tapered openings, such as... Figure 2 , Figure 3 As shown, it includes a sleeve cap 2, a locking nut 3, and a sleeve 4.

[0031] like Figure 2 , Figure 3 As shown, the sleeve cap 2 is assembled on the left end of the sleeve 4, and the locking nut 3 fixes the screw-in position of the sleeve cap 2.

[0032] Specifically, such as Figure 4 As shown, the inner edge of the left end port of the sleeve 4 is a right-angled edge 6. The outer circle of the left end of the sleeve 4 is provided with an external thread, and the outer circle of the sleeve 4 is also provided with an annular groove 7. During the machining process of the part, the annular groove 7 is used for machine tool clamping and positioning.

[0033] The inner circle of the right end port of the sleeve is chamfered 8, and the angle of chamfer 8 is β.

[0034] Specifically, such as Figure 5 , Figure 6 As shown, the sleeve cap 2 has a flat opening 9 on its outer circumference, and the inner hole of the sleeve cap 2 is a blind hole with an internal thread that matches the external thread. The design of the flat opening 9 facilitates the disassembly and assembly of the sleeve cap 2 using a wrench or other tools.

[0035] Specifically, the cross-sectional structure of the thin-walled long tube 5 processed in this embodiment is as follows: Figure 1 As shown, the right end of the thin-walled long tube 5 is a conical opening 1, and the angle of the conical opening 1 is α. The angle β of the chamfer 8 is equal to the angle α of the conical opening 1.

[0036] In use, the left end face of the sleeve 4 is fitted with the inner end face of the sleeve cover 2, and the locking nut 3 locks the sleeve cover 2 to prevent it from loosening. The thin-walled long tube 5 is placed in the inner hole of the sleeve 4, and the left end face of the thin-walled long tube 5 is fitted with the inner end face of the sleeve cover 2, which can position the thin-walled long tube 5, replacing the method of directly clamping the workpiece in the prior art, and playing an auxiliary clamping role.

[0037] like Figure 2 , Figure 3 , Figure 4 As shown, because the right-angled edge 6 is a right-angled edge, there is no gap between the left end face of the sleeve 4 and the inner end face of the sleeve cover 2. Therefore, during the part processing, the left end face of the thin-walled long tube 5 has no deformation space.

[0038] like Figure 1 , Figure 4As shown, the total length M of the sleeve 4 is 1mm to 3mm shorter than the total length L of the thin-walled tube 5. When the thin-walled tube 5 is inserted into the sleeve 4 and its left end abuts against the sleeve cover 2, its right end is placed at the right end port of the sleeve 4 and extends 1mm to 3mm beyond the right end port of the sleeve 4. This makes it convenient for the mold to directly stamp the port of the thin-walled tube 5, so that the port of the thin-walled tube 5 forms a tapered opening 1 that fits with the chamfer 8, avoiding the thin-walled tube 5 from being under-expanded or over-expanded, and improving the quality of the tapered opening of the thin-walled tube 5.

[0039] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, in order to facilitate the insertion of the thin-walled long tube 5 into the sleeve 4 and to prevent the thin-walled long tube 5 from bending and deforming when expanding the conical opening, the sleeve 4 and the thin-walled long tube 5 are fitted with a clearance and the fit tolerance is 0.1mm to 1mm.

[0040] The specific method for using this thin-walled long tube expansion and taper auxiliary clamping tool to expand the taper of a thin-walled long tube is as follows: (1) Tighten the sleeve cap to the first end of the sleeve and lock the sleeve cap with the lock nut; (2) Insert the thin-walled long tube to be expanded into the sleeve, so that one end of the thin-walled long tube abuts against the sleeve cover and the other end is placed at the second end port of the sleeve and extends out of the sleeve by 1mm to 3mm. (3) Position the sleeve on the machine tool. The clamping part is an annular groove to ensure that the second end of the sleeve is aligned with the mold on the machine tool. (4) Move the mold on the machine tool toward the sleeve and directly punch the thin-walled long tube end so that the thin-walled long tube end forms a tapered opening that fits with the inner chamfer of the second end of the sleeve. (5) Retract the mold on the machine tool and remove the thin-walled long tube with the tapered opening already completed, and the tapered opening operation of a thin-walled long tube can be completed. (6) Insert the next thin-walled long tube into the sleeve and repeat steps (4) and (5) to complete the tapering operation of the next thin-walled long tube. Repeat this operation multiple times to complete the tapering operation of all thin-walled long tubes in a small batch.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A clamping fixture for assisting in the expansion and conical opening of a thin-walled long tube, characterized in that: It includes a sleeve for clamping on a machine tool and adapting to the insertion of a thin-walled long tube. The first end of the sleeve is provided with a sleeve cap. The inner circle edge of the first end port of the sleeve is a right-angle edge. The inner circle of the second end port of the sleeve is provided with a chamfer for adapting to the expanded tapered opening of the thin-walled long tube. The length of the sleeve is 1mm to 3mm shorter than the length of the thin-walled long tube.

2. The auxiliary clamping fixture for expanding the conical opening of a thin-walled long tube according to claim 1, characterized in that: The outer circumference of the first end of the sleeve is provided with an external thread, and the inner circumference of the sleeve cover is provided with an internal thread that matches the external thread.

3. The auxiliary clamping fixture for expanding the conical opening of a thin-walled long tube according to claim 2, characterized in that: A locking nut that is tightly pressed against the end of the sleeve is also threaded onto the outer circumference of the first end of the sleeve.

4. The auxiliary clamping fixture for expanding the conical opening of a thin-walled long tube according to any one of claims 1-3, characterized in that: The outer circumference of the sleeve is provided with an annular groove to facilitate the machine tool's fixing, clamping, and positioning.

5. The auxiliary clamping fixture for expanding the conical opening of a thin-walled long tube according to any one of claims 1-3, characterized in that: The outer circumference of the sleeve cap is provided with an off-center opening.

6. The auxiliary clamping fixture for expanding the conical opening of a thin-walled long tube according to any one of claims 1-3, characterized in that: The sleeve and the thin-walled long tube are fitted with a clearance and the fit tolerance is 0.1mm to 1mm.

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