Thin-wall circular ring one-time forming layered trepanning machining method

Abstract

The invention relates to a thin-wall circular ring one-time forming layered trepanning machining method, and belongs to the technical field of machining. The machining method is characterized by comprising the following steps that (a) a disc blank is clamped on a four-jaw chuck of a lathe, and the outer circle clamping position is adjusted, so that the coaxiality jerk value of the center position of the disc blank and a main shaft of the lathe is smaller than or equal to 0.05 mm; (b) according to the machining number of the thin-wall circular rings, layered machining is conducted in sequence from outside to inside, and rough machining grooving, finish machining inner hole / outer circle and conical surface angle compensation turning are conducted on each layer in sequence; (c) an outer circle clamping mode and an inner hole tight supporting clamping mode are dynamically switched, the clamping force is adjusted in a self-adaptive mode according to the clamping position of the chuck, and the oil pressure is controlled to be 0.8-1.2 MPa; and (d) cutting off and separating the part by adopting an inner hole groove cutter, wherein the feed amount is less than or equal to 0.1 mm / r. The method has the advantages that one-time forming machining of the thin-wall circular ring is achieved through a layered trepanning strategy and dynamic clamping compensation, and the problems that a traditional process tool is high in dependency and low in machining precision are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to a thin-walled ring one-time forming layered sleeve processing method, in particular to a high-precision, low-cost one-time forming layered sleeve processing method for thin-walled ring parts, which is suitable for single piece / small batch trial production of thin-walled parts in the fields of aerospace, precision instruments, etc., and belongs to the technical field of machining. BACKGROUND

[0002] Traditional thin-walled ring processing needs to rely on special tooling for multiple clamping and sleeve processing, which has the following defects: 1. The development cycle of special tooling is long (3-5 weeks), the cost is high (single sleeve cost is 20-50 thousand yuan), and the economy is poor; 2. Multiple clamping leads to cumulative error, roundness error > 0.1mm, coaxiality out-of-tolerance rate ≥25%; 3. The sleeve allowance distribution is unreasonable, which is easy to cause clamping deformation, and the roundness qualification rate of finished product ≤20%.

[0003] Although the prior art such as CN115533170A (a thin-walled part machining clamp, thin-walled part machining equipment and machining method) reduces deformation through hydraulic expansion clamping, it needs to customize the clamp and cannot realize multi-specification part compatibility. Therefore, it is urgent to develop an efficient processing method without special tooling and suitable for multi-size thin-walled parts. SUMMARY

[0004] The purpose of the present application is to provide a processing method for one-time forming of thin-walled ring by layered sleeve processing strategy and dynamic clamping compensation, which solves the problem of strong dependence on traditional process tooling and low machining precision.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme: A thin-walled ring one-time forming layered sleeve processing method, characterized in that it comprises the following steps: (a) Clamping the disc blank on the four-jaw chuck of the lathe, adjusting the outer circle clamping position, so that the center position of the disc blank and the coaxiality runout of the lathe main shaft ≤0.05mm; (b) According to the number of thin-walled ring processing, layered processing from outside to inside, each layer in turn performs rough machining slotting, fine machining inner hole / outer circle and taper angle compensation turning; (c) Dynamically switching between outer circle clamping and inner hole supporting clamping mode, the clamping force is self-adaptively adjusted according to the chuck clamping position, and the oil pressure is controlled at 0.8-1.2MPa; (d) Using inner hole slotting cutter to cut and separate the parts, the feed rate ≤0.1mm / r.

[0006] The rough machining slotting is end face slotting along the set diameter using sleeve drilling; The depth of the roughing groove is: the thickness of the disc blank - (2±0.1) mm, with a radial allowance of 3 mm; The finishing of the inner hole: use an internal turning tool to machine the inner hole to the target size, with a feed rate of 0.1 mm / r and a spindle speed of 500 r / min; The finishing of the outer diameter: switch to an outer diameter turning tool to machine the outer diameter to the target wall thickness, with a cutting depth of 0.2 mm and a tool tip radius of R0.4 mm; The angle-compensated turning is achieved by adjusting the angle of the lathe's small pallet, using a dial indicator to calibrate the tool path angle, with a compensation value Δθ = 0.5°. The dynamic switching of outer circle clamping and inner hole support clamping method is as follows: First piece clamping: a four-jaw chuck clamps the outer circle of the disc blank; Subsequent clamping: switch to the machined inner hole for radial support, and use copper soft claws for buffering. The clamping force is adaptively adjusted according to the chuck clamping position. The hydraulic pressure of the outer diameter clamping hydraulic chuck is controlled at 1.0 to 1.2 MPa, and the hydraulic pressure of the inner diameter supporting hydraulic chuck is controlled at 0.8 to 1.0 MPa. The part is cut and separated by an internal grooved cutter. The internal grooved cutter cuts along a predetermined width, and the surface roughness Ra is ≤ 3.2 μm.

[0007] The beneficial effects of this invention are: (1) Layered nesting strategy: By processing the inner → outer → inner sequence and pre-allocating the allowance (radial 3mm, axial 0.2mm), the balance between part clamping and processing is achieved. There is enough clamping position to withstand the deformation of the part under stress, and there is enough space to realize the cutting of the tool. (2) Angle dynamic compensation mechanism: Based on the small pallet angle deviation Δθ, the angle of the tool path is corrected by a dial indicator during the machining of the conical surface, with an angle accuracy of ±0.1°; (3) Clamping force adaptive control: The clamping force of the hydraulic chuck is automatically adjusted according to the clamping position (outer circle / inner hole), and the oil pressure is controlled at (0.8~1.2MPa) to reduce thin-wall deformation. Attached Figure Description

[0008] Fig. 1 : Position diagram of the thin-walled ring within the same blank; Fig. 2 : Dynamic clamping and processing sequence diagram of layered nesting; Fig. 3 Schematic diagram of a thin-walled circular ring part; Fig. 4 : 3D schematic diagram of a thin-walled circular ring part.

[0009] In the diagram: 1-Disc blank; 2-Four-jaw chuck. Detailed Implementation

[0010] The application will be further described in connection with the following examples, which do not limit the scope of the application: Examples

[0011] Referring to the drawings Figs. 1-4 : (1) Blank pretreatment Clamping and positioning: a disc blank with a diameter of 400 mm and a thickness of 15 mm is provided, and a four-jaw chuck is used to clamp the outer circle on the lathe, and the center position of the disc blank is aligned with the coaxial jump amount of the main shaft of the lathe to be adjusted to ≤0.05 mm; Making a center hole: using a sleeve machining method, a slot is cut along the set diameter of 215 mm, the slot depth is the thickness of the disc blank 15 mm, the center of the disc is removed, and a radial allowance of 3 mm for the first small straight ring inner hole is reserved for finishing.

[0012] (2) Layered sleeve machining first stage (first small straight ring) Rough machining stage: Using a sleeve machining method, a slot is cut along the set diameter of 226-244 mm, the slot depth is 13±0.1 mm, and a radial allowance of 3 mm for the first small straight ring outer circle is reserved for finishing.

[0013] Finishing stage: a. Use an inner hole turning tool to process the end face of the small straight ring, and turn it flat without defects, which serves as a tool setting and size reference in the subsequent processing process, the feed rate is 0.2 mm / r, and the spindle speed is 500 r / min; b. Use an inner hole turning tool to process the inner hole to the target size of 218 mm, and perform hole chamfering, the feed rate is 0.1 mm / r, the cutting depth is 1 mm, and the spindle speed is 500 r / min; c. Switch to an outer circle turning tool to process the outer circle to a target wall thickness of 2.5 mm, the feed rate is 0.1 mm / r, the cutting depth is 0.2 mm, the spindle speed is 500 r / min, and the tool tip radius is 0.4 mm; d. Switch to an inner hole groove tool, use the end face as the tool setting reference, ensure the length of the small straight ring is 9 mm, and perform cutting operation to complete the overall processing of the small straight ring.

[0014] e. Switch to an inner hole turning tool, process the inner hole diameter to 246 mm, the depth is the thickness of the disc blank 15 mm, the feed rate is 0.1 mm / r, the cutting depth is 1 mm, and the spindle speed is 500 r / min. Turn the inner hole flat to prepare for subsequent processing.

[0015] (3) Layered sleeve machining second stage (second large conical ring, third small conical ring, fourth large straight ring) Change the clamping method: unload the disc blank from the four-jaw chuck, adjust the position of the four jaws, make the jaws support and clamp from the inner hole of the disc blank, and perform the alignment work, so that the center position of the disc blank and the coaxial jump of the lathe spindle is adjusted to ≤0.05mm; The second large taper ring is processed in layers in the following sequence: Rough machining stage: Using the sleeve machining method, the end face is grooved along the set diameter of 351-368mm, and the groove depth is 13±0.1mm, which reserves a radial allowance of about 3mm for the inner hole of the second large taper ring and the outer circle of the third small taper ring for subsequent machining.

[0016] Finish machining stage: a. Use the external turning tool to process the end face of the large taper ring, and turn it flat without defects, which serves as the tool setting and size reference in the subsequent machining process, the feed rate is 0.2mm / r, and the spindle speed is 500r / min; b. Switch to the inner hole turning tool to process the inner hole to the target size of 371.6mm, the feed rate is 0.1mm / r, the cutting depth is 1mm, and the spindle speed is 500r / min; c. Switch to the external turning tool to process the outer circle to the target size of 392.4mm, the feed rate is 0.1mm / r, the cutting depth is 1mm, and the spindle speed is 500r / min; d. Adjust the small apron angle to 30°, use the external turning tool to complete the turning of the end face (small bevel) of the large taper ring, and the angle deviation compensation value is Δθ=0.5°; e. Adjust the small apron angle to 60°, use the external turning tool to complete the turning of the outer circle (large bevel) of the large taper ring, and the angle deviation compensation value is Δθ=0.5°; f. Switch to the inner hole turning tool to complete the turning of the inner hole (large bevel) of the large taper ring, and the angle deviation compensation value is Δθ=0.5°; g. Adjust the small apron angle to 30°, switch to the inner hole groove tool, use the end face as the tool setting reference, ensure the length of the large taper ring, and perform the cutting operation to complete the overall machining of the large taper ring.

[0017] h. Switch to the external turning tool, process the outer circle diameter of the disc blank to 349mm, the depth is the thickness of the disc blank 15mm, the feed rate is 0.1mm / r, the cutting depth is 1mm, and the spindle speed is 500r / min. Turn the outer circle flat to prepare for subsequent machining.

[0018] The third small taper ring is processed in layers in the following sequence: Rough machining stage: Using sleeve processing method, along the set diameter Ø302-Ø326mm end face groove, groove depth 13±0.1mm, for the third piece of small cone ring hole and the fourth piece of small straight ring outer circle respectively reserved about 3mm radial allowance for finishing.

[0019] Finishing stage: a. Using the outer circle turning tool to process the small cone ring end face, turning flat without defects, as the tool setting and size reference in the subsequent processing process, feed rate 0.2mm / r, spindle speed 500r / min; b. Switching to inner hole turning tool to process inner hole to target size Ø329.2mm, feed rate 0.1mm / r, cutting depth 1mm, spindle speed 500r / min; c. Switching to outer circle turning tool to process outer circle to target size Ø345.8mm, feed rate 0.1mm / r, cutting depth 1mm, spindle speed 500r / min; d. Adjusting the small apron angle to 40°, using the outer circle turning tool to complete the turning of the small cone ring end face (small bevel), angle deviation compensation value Δθ=0.5°; e. Adjusting the small apron angle to 50°, using the outer circle turning tool to complete the turning of the small cone ring outer circle (large bevel), angle deviation compensation value Δθ=0.5°; f. Switching to inner hole turning tool, completing the turning of the small cone ring inner hole (large bevel), angle deviation compensation value Δθ=0.5°; g. Adjusting the small apron angle to 40°, switching to inner hole groove tool, taking the end face as the tool setting reference, ensuring the length of the small cone ring, and performing cutting-off operation to complete the overall processing of the small cone ring.

[0020] h. Switching to outer circle turning tool, processing the outer circle diameter size of the disc blank to Ø300mm, depth is the thickness of the disc blank 15mm, feed rate 0.1mm / r, cutting depth 1mm, spindle speed 500r / min, turning the outer circle flat to prepare for subsequent processing.

[0021] The fourth piece of large straight ring is processed in layers as follows: Rough machining stage: Using sleeve processing method, along the set diameter Ø260-Ø288mm end face groove, groove depth 13±0.1mm, for the fourth piece of large straight ring inner hole reserved about 3mm radial allowance for finishing.

[0022] Finishing stage: a. Using the inner hole turning tool to process the large straight ring end face, turning flat without defects, as the tool setting and size reference in the subsequent processing process, feed rate 0.2mm / r, spindle speed 500r / min; b. Use an internal turning tool to machine the inner hole to the target size Ø291mm, and chamfer the hole opening. The feed rate is 0.1mm / r, the depth of cut is 1mm, and the spindle speed is 500r / min. c. Switch to an external turning tool to machine the outer diameter to the target size Ø297mm, with a feed rate of 0.1mm / r, a depth of cut of 0.2mm, a spindle speed of 500r / min, and a tool tip radius of R0.4mm; d. Switch to the internal grooving tool, using the end face as the tool setting reference, ensure the length of the small straight ring is 10mm, and perform the cutting operation to complete the overall machining of the small straight ring.

[0023] (4) Finished product grinding After machining the four parts, the sharp edges of the cut surfaces are ground down to prevent them from posing a risk of cuts.

Claims

1. A method for one-time forming and layered nesting of thin-walled circular rings, characterized in that, Includes the following steps: (a) Clamp the disc blank on the four-jaw chuck of the lathe and adjust the outer diameter clamping position so that the coaxiality runout between the center position of the disc blank and the lathe spindle is ≤0.05mm; (b) Based on the number of thin-walled rings to be machined, the rings are machined in layers from the outside to the inside. Each layer is then roughed by grooving, finished by internal / external hole machining, and tapered surface angle compensation turning. (c) Dynamically switch between external diameter clamping and internal hole support clamping modes. The clamping force is adaptively adjusted according to the chuck clamping position, and the hydraulic pressure is controlled between 0.8 and 1.2 MPa. (d) Use an internal grooved cutter to cut and separate parts, with a feed rate ≤ 0.1 mm / r.

2. The method for one-time forming and layered nesting of thin-walled rings according to claim 1, characterized in that, The roughing grooving is performed by using a nesting drill to cut the end face along a set diameter.

3. The method for one-time forming and layered fabrication of thin-walled circular rings according to claim 2, characterized in that, The depth of the roughing groove is: the thickness of the disc blank - (2±0.1) mm, with a radial allowance of 3 mm.

4. The method for one-time forming and layered nesting of thin-walled rings according to claim 1, characterized in that, The finishing of the inner hole: use an internal turning tool to machine the inner hole to the target size, with a feed rate of 0.1 mm / r and a spindle speed of 500 r / min.

5. The method for one-time forming and layered nesting of thin-walled rings according to claim 1, characterized in that, The finishing of the outer circle: switch to an outer circle turning tool to machine the outer circle to the target wall thickness, with a cutting depth of 0.2 mm and a tool tip radius of R0.4 mm.

6. The method for one-time forming and layered nesting of thin-walled rings according to claim 1, characterized in that, The angle-compensated turning is achieved by adjusting the angle of the lathe's small support plate, using a dial indicator to calibrate the tool path angle, with a compensation value Δθ = 0.5°.

7. The method for one-time forming and layered nesting of thin-walled rings according to claim 1, characterized in that, The dynamic switching of outer circle clamping and inner hole support clamping method is as follows: the first piece is clamped, and the outer circle of the disc blank is clamped by a four-jaw chuck; subsequent clamping: switch to the machined inner hole for radial support, and use copper soft claws for buffering.

8. The method for one-time forming and layered nesting of thin-walled rings according to claim 1, characterized in that, The clamping force is adaptively adjusted according to the chuck clamping position. The hydraulic pressure of the outer diameter clamping hydraulic chuck is controlled at 1.0 to 1.2 MPa, and the hydraulic pressure of the inner diameter supporting hydraulic chuck is controlled at 0.8 to 1.0 MPa.

9. The method for one-time forming and layered nesting of thin-walled rings according to claim 1, characterized in that, The part is cut and separated by an internal grooved cutter. The internal grooved cutter cuts along a predetermined width, and the surface roughness Ra is ≤ 3.2 μm.

Images