Method for finishing a coaxial hole of a multi-layer earpiece

Abstract

The application discloses a kind of coaxial hole finishing methods of multilayer ear piece, comprising the following steps: 1) inject liquid wax between ear piece, after solidification, find the right part clamped and fixed on the workbench of machine tool;2) select short drill bit, process the target hole of first end two layers of ear piece of part;3) replace long drill bit, the target hole of all ear piece of part first end is drilled through;4) the target hole on each layer ear piece of part first end is milled and is expanded;5) the target hole on each layer ear piece of part first end is roughly reamed;6) remove the wax between each layer ear piece of part first end, the target hole on each layer ear piece of part first end is precisely reamed;7) repeat step 2)-6) to the target hole on each layer ear piece of part second end is finished.The processing method of the application adopts the mode of machining, no remelt layer is left in the orifice, and the machining precision is high.

Description

Technical Field

[0001] This invention relates to the field of hole machining technology, and in particular to a method for precision machining of coaxial holes in multi-layer lugs. Background Technology

[0002] like Figure 2 and Figure 3 The part shown has multiple layers of lugs at its first and second ends, with two sets of coaxial structural holes on each lug. The part is relatively long, the lugs are thin, and its overall rigidity is poor. When machining these structural holes, due to the part's poor rigidity and susceptibility to deformation, electrical discharge machining (EDM) is typically used. This method involves electrical discharge etching, which eliminates machining stress, prevents part deformation, and ensures the coaxiality of the holes at the machined area. However, the electrodes wear down during the discharge process. For parts with many lug layers, electrode wear can easily lead to non-compliant hole diameters when machining the last few holes. Furthermore, this machining method leaves a remelted layer at the hole opening, making it unsuitable for parts requiring a non-remelted layer at the hole opening or for parts made of copper.

[0003] Therefore, there is an urgent need for a machining method that has high processing precision, can effectively reduce part deformation, and will not leave a remelted layer at the opening. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method for precision machining of coaxial holes in multi-layer lugs, which adopts machining method, does not leave a remelted layer at the hole opening, can effectively reduce part deformation during machining, and has high machining accuracy.

[0005] The present invention provides a method for precision machining of coaxial holes in multi-layer ear pieces, comprising the following steps: 1) Inject liquid wax between each adjacent lug of the part, let it stand and solidify, then align and clamp the part on the machine tool's worktable. 2) Select a short drill bit with an outer diameter of 75%-85% of the inner diameter of the target hole design. Use a low speed of 600-800 r / min and a feed rate of 0.4-0.5 mm / z on the machine tool spindle to machine the target holes of the first two layers of lugs at the first end of the part. 3) Replace with a long drill bit of the same diameter as the short drill bit, increase the machine tool spindle speed, reduce the feed rate, and drill through all the target holes of the lugs at the first end of the part; 4) Use a milling cutter to mill and enlarge the target holes on each layer of lugs at the first end of the part, leaving a margin of 0.2-0.3mm; 5) Use the first reamer to rough ream the target holes on each layer of lugs at the first end of the part, enlarging each target hole and leaving a margin of 0.01-0.02mm; 6) Remove the wax between the layers of lugs at the first end of the part, and use the second reamer to fine ream the target holes on the layers of lugs at the first end of the part so that their inner diameter reaches the design value. 7) Repeat steps 2)-6) to finish the target holes on each layer of the lugs at the second end of the part.

[0006] Furthermore, in step 5), the total length of the first reamer is 240-280mm, the blade length is 10-15mm, the outer diameter of the smooth rod is 3‰ smaller than the outer diameter of the blade, and the straightness of the entire blade is less than 0.002mm.

[0007] Furthermore, in step 6), the dewaxing process is performed while the part is held and fixed on the machine tool.

[0008] Furthermore, in step 6), the total length of the second reamer is 240-280mm, the blade length is 10-15mm, the outer diameter of the smooth rod is 3‰ smaller than the outer diameter of the blade, and the straightness of the entire blade is less than 0.002mm. The polished rod portion of the second reamer is provided with a coolant channel, and the outer wall of the polished rod portion of the second reamer is evenly distributed with coolant outlets that communicate with the coolant channel.

[0009] Furthermore, in step 7), after rotating the machine tool's worktable 180°, the target holes on each layer of ear plates at the second end of the part are precision machined to avoid positioning errors caused by repeated clamping.

[0010] Furthermore, in step 7), after the target holes on each layer of ear pieces at the second end of the part are finished, the part is immersed in warm water at 46-68°C to remove residual wax, and then the part is taken out and air-dried.

[0011] Compared with the prior art, the beneficial effects of the present invention are: The processing method of this invention uses wax curing to improve the overall rigidity of the parts and effectively reduce the processing deformation of the parts; the machining method does not leave a remelted layer at the hole opening, ensuring the processing quality of the parts; controlling the outer diameter of the reamer's smooth rod (less than 3‰ of the outer diameter of the cutting edge) can effectively ensure the coaxiality of the hole at high speed, and the 3‰ gap of the smooth rod will not wear the inner wall of the target hole due to the lubrication of the coolant.

[0012] During processing, the first two layers of ear plates are processed to create target holes. When processing subsequent target holes, the first two layers of ear plates form a retainer, which greatly reduces the vibration of the drill rod when drilling subsequent target holes and significantly reduces processing errors.

[0013] Dewaxing before precision reaming reduces the impact of foreign matter on hole accuracy. During precision reaming, a reamer with centrally circulating coolant is used to cool the hole promptly and remove metal chips, effectively ensuring hole roughness and preventing wear, thus guaranteeing the machining accuracy of the parts.

[0014] It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of the present invention, nor is it intended to restrict the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0015] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 A flowchart illustrating the coaxial hole finishing method for multi-layer ear pieces; Figure 2 This is a structural schematic diagram of the part; Figure 3 This is a partial sectional view of the part. Figure 4 A schematic diagram of filling wax between the lugs of a component; Figure 5 This is a schematic diagram of the second reamer precision reaming the hole.

[0016] The diagram labels are: 1. Part; 2. Wax; 3. Second reamer; 11. Ear piece; 12. Target hole; 31. Coolant passage; 32. Coolant outlet. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] Please refer to Figures 1-5 The present invention provides a method for precision machining of coaxial holes in multi-layer ear pieces, comprising the following steps: 1) Inject liquid wax between each adjacent lug 11 of part 1, let it stand and solidify, then align and clamp part 1 on the machine tool worktable. 2) Select a short drill bit with an outer diameter of 75%-85% of the designed inner diameter of the target hole 12. Use a low speed of 600-800 r / min and a feed rate of 0.4-0.5 mm / z on the machine tool spindle to machine the target hole 12 of the first two layers of lugs 11 at the first end of part 1. 3) Replace with a long drill bit of the same diameter as the short drill bit, increase the machine tool spindle speed, reduce the feed rate, and drill through all the target holes 12 of the lugs 11 at the first end of part 1; 4) Use a milling cutter to mill and enlarge the target holes 12 on each layer of lugs 11 at the first end of part 1, leaving a margin of 0.2-0.3mm; 5) Use the first reamer to rough ream the target holes 12 on each layer of ear pieces 11 at the first end of part 1, enlarge each target hole 12, and leave a margin of 0.01-0.02mm; The first reamer has a total length of 240-280mm, a blade length of 10-15mm, an outer diameter of 3‰ smaller than the outer diameter of the blade, and a straightness of less than 0.002mm. 6) Keep part 1 clamped and fixed on the machine tool, manually remove the wax 2 between the layers of lugs 11 at the first end of part 1 with a blade to avoid positioning errors caused by repeated clamping; use the second reamer 3 to finely ream the target holes 12 on the layers of lugs 11 at the first end of part 1 so that their inner diameter reaches the design value. Among them, the total length of the second reamer 3 is 240-280mm, the blade length is 10-15mm, the outer diameter of the smooth part is 3‰ smaller than the outer diameter of the blade part, and the straightness of the whole blade is less than 0.002mm; The polished rod portion of the second reamer 3 is provided with a coolant channel 31, and the outer wall of the polished rod portion of the second reamer 3 is evenly distributed with coolant outlets 32 that are connected to the coolant channel 31. 7) After rotating the machine tool's worktable 180°, repeat steps 2)-6) to finish the target holes 12 on each layer of lugs 11 at the second end of part 1 to avoid positioning errors caused by repeated clamping; After the target holes 12 on each layer of ear pieces 11 at the second end of part 1 are finished, part 1 is immersed in warm water at 46-68℃ to remove residual wax, and then part 1 is taken out and air-dried.

[0020] In this embodiment, a horizontal machining center is selected, with a machine tool worktable that can rotate 180° and a machine tool repeatability of ±0.001mm. The target hole 13 on part 1 is machined in two stages from both ends toward the middle. The target hole 12 on the lug 11 at the first end of part 1 is machined in the same way as the target hole 12 on the lug 11 at the second end.

[0021] Before fine reaming, dewaxing 2 is performed to ensure the smoothness of the target hole. Since the diameter of the reamer is equal to the hole diameter, the gap between the smooth rod and the hole wall is only a few thousandths. At high speed, fine iron filings will scratch the hole wall. Dewaxing 2 allows the iron filings to be flushed out in time by the coolant in the center of the reamer at high speed, without scratching the hole wall and ensuring the roughness of the hole.

[0022] The processing method of this application adopts machining, which will not leave a remelted layer at the hole opening, and can effectively reduce the processing deformation of part 1. It has high processing accuracy, greatly improves the pass rate of part 1, and has a wide range of applications.

[0023] In the description of this specification, the terms "connection," "installation," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In the description of this specification, the terms "one embodiment," "some embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0025] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for precision machining of coaxial holes in multi-layer ear pieces, characterized in that, Includes the following steps: 1) Inject liquid wax between each adjacent ear piece (11) of part (1), let it stand and solidify, then align and clamp part (1) on the worktable of the machine tool. 2) Select a short drill bit with an outer diameter of 75%-85% of the inner diameter of the target hole (12). Use a low speed of 600-800r / min and a feed rate of 0.4-0.5mm / z to process the target hole (12) of the first two layers of lugs (11) at the first end of the part (1). 3) Replace with a long drill bit of the same diameter as the short drill bit, increase the spindle speed of the machine tool, reduce the feed rate, and drill through the target hole (12) of all the lugs (11) at the first end of part (1); 4) Use a milling cutter to mill and enlarge the target holes (12) on each layer of ear pieces (11) at the first end of part (1), leaving a margin of 0.2-0.3mm; 5) Use the first reamer to rough ream the target holes (12) on each layer of ear pieces (11) at the first end of part (1), enlarge each target hole (12), and leave a margin of 0.01-0.02mm; 6) Remove the wax (2) between the layers of ear pieces (11) at the first end of part (1), and use the second reamer to fine ream the target hole (12) on the layers of ear pieces (11) at the first end of part (1) so that its inner diameter reaches the design value. 7) Repeat steps 2)-6) to finish the target holes (12) on each layer of ear pieces (11) at the second end of part (1).

2. The method for precision machining of coaxial holes in multi-layer ear pieces according to claim 1, characterized in that, In step 5), the total length of the first reamer is 240-280mm, the blade length is 10-15mm, the outer diameter of the smooth part is 3‰ smaller than the outer diameter of the blade part, and the straightness of the whole blade is less than 0.002mm.

3. The method for precision machining of coaxial holes in multi-layer ear pieces according to claim 1, characterized in that, In step 6), the dewaxing process is carried out while the part (1) is clamped and fixed on the machine tool.

4. The method for precision machining of coaxial holes in multi-layer ear pieces according to claim 1, characterized in that, In step 6), the total length of the second reamer (3) is 240-280mm, the blade length is 10-15mm, the outer diameter of the smooth rod part is 3‰ smaller than the outer diameter of the blade part, and the straightness of the whole blade is less than 0.002mm. The polished rod portion of the second reamer (3) is provided with a coolant channel (31), and the outer wall of the polished rod portion of the second reamer (3) is evenly distributed with coolant outlets (32) that communicate with the coolant channel (31).

5. The method for precision machining of coaxial holes in multi-layer ear pieces according to claim 1, characterized in that, In step 7), after rotating the machine tool table 180°, the target holes (12) on each layer of ear pieces (11) at the second end of the part (1) are precision machined to avoid positioning errors caused by repeated clamping.

6. The method for precision machining of coaxial holes in multi-layer ear pieces according to claim 1, characterized in that, In step 7), after the target holes (12) on each layer of ear pieces (11) at the second end of part (1) are finished, part (1) is immersed in warm water at 46-68℃ to remove residual wax (2), and then part (1) is taken out and air-dried.

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