Machining method for low-stress clamping alignment machining of precise thin-wall parts

Abstract

The invention discloses a machining method for low-stress clamping alignment machining of a precise thin-wall part. The turning and grinding machining of the spherical surface of the part are completed through a series of modes such as special tool design, technological process size optimization and repeated measurement, and the machining method is a method for guaranteeing the high-precision size of the precise part. The method is suitable for machining parts with the dimensional tolerance within 0.005 mm, hot melt adhesive is not adopted, local heating deformation is achieved, and the precision of the final forming size of the parts is affected.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a processing method for low-stress clamping and alignment processing of precision thin-walled parts. Background Art

[0002] Thin-walled weak rigid parts are widely used in all walks of life. Some parts require micron-level surface dimension processing accuracy due to usage requirements. This type of parts has poor structural rigidity and adopts traditional clamping methods (such as internal support, clamping outer circle, and clamping end face). The clamping stress will cause local deformation of the parts, affecting the processing accuracy and making it impossible to guarantee the final dimensional tolerance of the parts. For the processing of this type of parts, special tooling is designed and process inspection is strengthened to ensure that the final size of the parts meets the high-precision design index requirements. Through searching, it was found that an invention patent (CN108214006A) for a method for clamping thin-walled precision parts using hot melt adhesive bonding is similar to the present invention patent. The difference is that the invention patent highlights the convenience of hot melt adhesive bonding processing of thin-walled precision parts, but the degree of accuracy assurance is not enough. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides a processing method for low-stress clamping and alignment processing of precision thin-walled parts, which completes the turning and grinding of the spherical surface of the part through a series of methods such as designing special tooling, optimizing process dimensions, and repeated measurements. It is a method for ensuring the high-precision dimensions of precision parts, and is suitable for processing parts with a dimensional tolerance within 0.005mm. It does not use hot melt adhesive, which will cause local deformation due to heat, and will affect the accuracy of the final molding size of the part.

[0004] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0005] Step 1: Bond and tighten the product and the tooling. The distance between the center of the spherical surface and the reference plane is the bonding surface. The flatness of the product end face and the tooling end face is required to be within jmm to ensure the end face fit;

[0006] Step 2: Make the matching surface of the tooling match the inner cylindrical surface of the product to ensure that the inner and outer cylindrical surfaces fit together and play a supporting role during the processing. Use liquid glue to bond the inner annular seam. After the liquid glue solidifies, connect the tooling with the spindle adapter plate using the pin fixing hole, and clamp the spindle adapter plate on a high-precision CNC horizontal lathe or high-precision CNC grinding machine equipment;

[0007] Step 3: Before product processing, determine the tool tip zero point with the product's large end face and the outer cylindrical surface of the matching tooling. To ensure that the coaxiality between the sphere center and the outer cylindrical surface is no greater than k, the cylindricity of the outer cylindrical surface must be within n. To meet the sphere center distance tolerance ±p, determine the sphere center coordinates by measuring the distance from the bonding surface to the large end face minus the sphere center distance. The large end face flatness is required to be within emm, and the bonding surface flatness is required to be within fmm. After the product is clamped, the axial detection error is within g, and sufficient size adjustment space is reserved.

[0008] Step 4: For the first processing, find the outer cylindrical surface of the matching tooling within h, ensure the coaxiality between the center of the product spherical surface and the outer cylindrical surface, start processing the spherical surface, ensure that the spherical surface is fully turned / ground to light, remove the pin, use three-coordinate measurement to detect the relevant dimensions of the spherical surface, and adjust the CNC program according to the spherical radius and the distance between the spherical center;

[0009] Step 5: Secondary processing: Use a pin to fix the product and the matching tooling on the spindle connecting plate to ensure that the axial and radial positions of the product do not move; turn / grind the spherical surface again, retain the spherical surface machining allowance, remove the pin, use three-coordinate detection of the spherical surface related dimensions, and determine whether the adjusted CNC program is processed in place according to the theoretical value. If it is processed in place, the tool tip trajectory is offset to the center of the ball as a whole, and all machining allowances are removed. If it is not processed in place, readjust the CNC program, and repeat the processing and detection;

[0010] Step 6: After machining, remove the pin, use a debonding agent to remove the matching tooling, and inspect the relevant dimensions of the product spherical surface in a free state.

[0011] Preferably, j=0.005, k=0.02, n=0.01, p=0.023, e=0.005, f=0.005, g=0.01, and h=0.01.

[0012] A computer program, which enables a computer to execute the above processing method.

[0013] An electronic device comprises: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device executes the above-mentioned processing method.

[0014] A computer-readable storage medium stores a computer program, which implements the above-mentioned processing method when executed by a processor.

[0015] A chip includes: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes the above-mentioned processing method.

[0016] A computer program product comprises a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and the above-mentioned processing method is implemented when the instructions are executed by the at least one processor.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The bonding stress of the product of the method of the present invention is low, and the effect of removing the tooling on the product deformation is negligible, which is suitable for processing precision parts;

[0019] 2. The product dimension chain transfer method of the method of the present invention is real and effective, and can be further applied to the processing of ultra-precision parts;

[0020] 3. The method of the present invention realizes the precise machining of the spherical surface of parts and forms a complete machining method. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the parts of the present invention;

[0022] Figure 2 This is a schematic diagram of the clamping of the product of the present invention.

[0023] In the figure, 1 is the main shaft connecting plate, 2 is the matching tooling, 3 is the pin, and 4 is the product. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] The problem to be solved by the present invention is a high-precision spherical surface precision machining method for products. At present, the precision turning benchmark, bonding clamping and process detection of such products have been clarified, and the product molding size free state detection is qualified.

[0026] In order to ensure that the product processing accuracy and final size detection meet the design requirements, the present invention completes the turning and grinding of the spherical surface of the part by designing special tooling, optimizing process dimensions, repeating measurements and a series of other methods.

[0027] by Figure 1 For example, in the figure, A is a spherical surface, and the relevant size requirements are B is the distance between the sphere centers 73.5±0.023 (based on the inner step end face), and C is the product requirement that the coaxiality between the spherical center and the inner cylindrical surface D reference surface is not greater than 0.02.

[0028] like Figure 2As shown, the product and the tooling are bonded and fastened, and the distance between the center of the spherical surface and the reference plane is the bonding surface. The flatness of the end face of the product and the end face of the tooling is required to be within 0.005mm to ensure the end face fit. The matching surface of the tooling is matched with the inner cylindrical surface of the product to ensure the fit of the inner and outer cylindrical surfaces. It plays a supporting role in the processing process. Liquid glue is used to bond the inner annular seam. After the liquid glue solidifies, the matching tooling and the spindle adapter plate are connected with the pin fixing hole, and the spindle adapter plate is clamped on a high-precision CNC horizontal lathe or high-precision CNC grinding machine equipment. Before product processing, the tool tip zero point is determined by the large end face of the product and the outer cylindrical surface of the matching tooling. To ensure that the coaxiality between the sphere center and the outer cylindrical surface is no more than 0.02, the cylindricity of the outer cylindrical surface must be within 0.01. To meet the sphere center distance tolerance of ±0.023, the sphere center coordinates are determined by measuring the distance from the bonding surface to the large end face and subtracting the sphere center distance. The flatness of the large end face is required to be within 0.005mm, and the flatness of the bonding surface is required to be within 0.005mm. After the product is clamped, the axial detection error is within 0.01, and sufficient space for size adjustment is reserved.

[0029] For the first processing, find the outer cylindrical surface of the matching tooling within 0.01 to ensure the coaxiality of the center of the product spherical surface and the outer cylindrical surface, start processing the spherical surface, ensure that the spherical surface is completely turned / ground to light, remove the pin, use three-coordinate measurement to detect the relevant dimensions of the spherical surface, and adjust the CNC program according to the spherical radius and the center distance.

[0030] For secondary processing, the product and the matching tooling are fixed to the spindle connecting plate with a pin to ensure that the axial and radial positions of the product do not move. The spherical surface is turned / ground again, and the spherical machining allowance is retained. The pin is removed and the relevant dimensions of the spherical surface are detected using three-coordinate measurement to determine whether the adjusted CNC program has been processed in place according to the theoretical value. If it has been processed in place, the tool tip trajectory is offset toward the center of the sphere as a whole to remove all machining allowances. If it has not been processed in place, the CNC program is readjusted and the processing and inspection are repeated.

[0031] After machining is completed, remove the pin, use a degumming agent to remove the matching tooling, and inspect the relevant dimensions of the product's spherical surface in a free state.

[0032] Example:

[0033] 1. First, place the product and the matching tooling Figure 2 Assemble as shown, use low-temperature metal glue for cold bonding at the M position, fix the spindle connecting plate on the equipment spindle, and align the end face of the spindle connecting plate;

[0034] 2. After the product is firmly bonded to the matching tooling, fix it to the spindle connecting plate through the pin shaft and align the outer circle and end face of the product;

[0035] 3. During the product processing, the product size is repeatedly tested by removing the pin to ensure that the product processing size meets the design requirements.

Claims

1. A method for low-stress clamping and alignment processing of precision thin-walled parts, characterized in that: The steps include: Step 1: Bond and tighten the product and the tooling. The distance between the center of the spherical surface and the reference plane is the bonding surface. The flatness of the product end face and the tooling end face is required to be within jmm to ensure the end face fit; Step 2: Make the matching surface of the tooling match the inner cylindrical surface of the product to ensure that the inner and outer cylindrical surfaces fit together and play a supporting role during the processing. Use liquid glue to bond the inner annular seam. After the liquid glue solidifies, connect the tooling with the spindle adapter plate using the pin fixing hole, and clamp the spindle adapter plate on a high-precision CNC horizontal lathe or high-precision CNC grinding machine equipment; Step 3: Before product processing, determine the tool tip zero point with the product's large end face and the outer cylindrical surface of the matching tooling. To ensure that the coaxiality between the sphere center and the outer cylindrical surface is no greater than k, the cylindricity of the outer cylindrical surface must be within n. To meet the sphere center distance tolerance ±p, determine the sphere center coordinates by measuring the distance from the bonding surface to the large end face minus the sphere center distance. The large end face flatness is required to be within emm, and the bonding surface flatness is required to be within fmm. After the product is clamped, the axial detection error is within g, and sufficient size adjustment space is reserved. Step 4: For the first processing, find the outer cylindrical surface of the matching tooling within h, ensure the coaxiality between the center of the product spherical surface and the outer cylindrical surface, start processing the spherical surface, ensure that the spherical surface is fully turned / ground to light, remove the pin, use three-coordinate measurement to detect the relevant dimensions of the spherical surface, and adjust the CNC program according to the spherical radius and the distance between the spherical center; Step 5: Secondary processing: Use a pin to fix the product and the matching tooling on the spindle connecting plate to ensure that the axial and radial positions of the product do not move; turn / grind the spherical surface again, retain the spherical surface machining allowance, remove the pin, use three-coordinate detection of the spherical surface related dimensions, and determine whether the adjusted CNC program is processed in place according to the theoretical value. If it is processed in place, the tool tip trajectory is offset to the center of the ball as a whole, and all machining allowances are removed. If it is not processed in place, readjust the CNC program, and repeat the processing and detection; Step 6: After machining, remove the pin, use a debonding agent to remove the matching tooling, and inspect the relevant dimensions of the product spherical surface in a free state.

2. A method for low-stress clamping and alignment machining of precision thin-walled parts according to claim 1, characterized in that: Said j=0.005, k=0.02, n=0.01, p=0.023, e=0.005, f=0.005, g=0.01, h=0.

01.

3. A computer program, characterized in that The computer program enables a computer to execute the method according to any one of claims 1 to 2.

4. An electronic device, characterized in that: include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device executes the method as claimed in any one of claims 1 to 2.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 2 is implemented.

6. A chip, characterized in that: include: A processor, configured to call and run a computer program from a memory, so that a device equipped with the chip executes a method as claimed in any one of claims 1 to 2.

7. A computer program product, characterized in that The computer program product comprises a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and when the instructions are executed by the at least one processor, the method according to any one of claims 1 to 2 is implemented.

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