Finishing method for large stainless steel thin plate annular parts and tooling used for the method

Abstract

The present invention discloses a method for fine-machining large stainless steel thin-plate annular parts and a tooling for this method. The tooling utilizes a base to mount the workpiece, changing the conventional clamping method. Different pressure plates are designed to cooperate with the base to clamp different parts of the workpiece when machining different parts, thereby eliminating the extrusion force generated by the tool during machining. Finally, the tool path during machining is modified to eliminate the effects of cutting heat and ensure the flatness of the product. The method is simple to operate and can be operated on a CNC vertical lathe. It effectively eliminates deformation caused by cutting heat and clamping issues, achieves high machining accuracy, and meets the requirements for machining internal holes, planes, and end-face openings. It also offers good reliability, high precision, and low equipment investment and cost.

Description

Technical Field

[0001] The present invention relates to the field of plate processing, in particular to a method for fine processing of large stainless steel thin plate annular parts and a tool used for the method. Background Art

[0002] Thin plate parts refer to parts with a thickness to diameter ratio exceeding 1:50. In the shipbuilding industry, stainless steel thin plate parts are widely used due to their light weight, low material consumption, compact structure, and good corrosion resistance.

[0003] In actual production, stainless steel, due to its special material properties, is prone to generate cutting heat during processing, causing deformation of the workpiece.

[0004] For large thin-plate annular parts (diameter greater than 1500mm, thickness less than 20mm), they need to be processed into a structure with an outer circle, an inner hole, and an opening on the end face. During fine machining, due to their small axial size, they are very easy to deform when clamped.

[0005] Large stainless steel thin plate ring parts have the above two difficulties, especially in the case that many companies do not have large grinders and surface milling machines, but only CNC vertical lathes, processing large stainless steel thin plate ring parts has become a thorny problem in mechanical processing. Summary of the Invention

[0006] The purpose of the present invention is to solve the above technical problems and provide a method for finishing large stainless steel thin plate annular parts with a simple operation method, which can be operated using a CNC vertical lathe, effectively solves the deformation caused by cutting heat and clamping problems, has high processing accuracy, meets the requirements of processing internal holes, planes and end face openings, has good reliability, high precision, low equipment investment and cost.

[0007] The present invention also provides a tool specially used for the above processing method.

[0008] The large stainless steel thin plate annular part finishing tool of the present invention includes a base, the inner hole of the base is a stepped hole that is larger at the top and smaller at the bottom, including a large hole in the upper section and a small hole in the lower section, the diameter of the large hole in the upper section is larger than the outer circle diameter of the thin plate annular part, and the diameter of the small hole in the lower section is larger than the inner hole diameter of the thin plate annular part; the outer shape of the base is a stepped cylinder that is larger at the top and smaller at the bottom, including a large cylinder in the upper section and a small cylinder in the lower section, and a plurality of first screw holes are evenly arranged on the outer circle surface of the large cylinder.

[0009] The bottom surface of the small hole of the base is provided with a bottom plate, and the bottom plate is evenly and annularly provided with a plurality of second screw holes along the circumferential direction; it also includes an L-shaped pressing plate, and screw holes are provided at both ends of the L-shaped pressing plate.

[0010] The top end surface of the large cylinder is also evenly provided with a plurality of third screw holes; it also includes an I-type pressure plate and a Z-type pressure plate, one end of the I-type pressure plate is provided with a screw hole, and both ends and the middle section of the Z-type pressure plate are provided with screw holes.

[0011] A plurality of notches are evenly opened on the body of the large cylinder, and the lower ends of the notches are flush with the bottom surface of the large hole.

[0012] The diameter of the large hole is 0.1-0.2 mm larger than the outer diameter of the annular part.

[0013] The method for finishing large stainless steel thin plate annular parts of the present invention uses the above-mentioned tooling and is carried out in the following processing steps:

[0014] 1) Assemble the circular thin plate workpiece to be processed onto the base so that the bottom surface of the circular thin plate workpiece fits into the bottom surface of the large hole, and the gap between the diameter of the circular thin plate workpiece and the diameter of the large hole of the base is 0.1-0.2mm;

[0015] 2) Clamp the base with the circular thin plate workpiece onto a CNC vertical lathe, with the jaws of the CNC vertical lathe clamping the small cylinder of the base;

[0016] 3) Pass the first threaded pressure rod through the first screw hole on the outer circumference of the large cylinder and press it tightly on the outer circumference of the circular thin plate workpiece to fix the circular thin plate workpiece, control the tool to turn the inner hole of the circular thin plate workpiece, complete the inner hole processing of the circular thin plate workpiece, and obtain the annular thin plate workpiece.

[0017] 4) After the inner hole processing is completed, the L-shaped pressure plate is installed and fixed to the bottom plate with a first bolt passing through the screw hole of the lower section of the L-shaped pressure plate and the screw hole on the bottom plate, and then a second threaded pressure rod is passed horizontally through the screw hole on the upper section of the L-shaped pressure plate to press it tightly against the inner hole surface of the annular thin plate workpiece;

[0018] 5) Controlling the tool to turn the upper end surface of the annular thin plate workpiece, the turning method is as follows: a) first turning from the outer circle to the inner hole, and then turning from the inner hole to the outer circle; repeating step a) at least once until the process allowance requirement is met;

[0019] 6) Then loosen the first threaded pressure rod, remove the L-shaped pressure plate, turn the annular thin plate workpiece 180 degrees, re-tighten the first threaded pressure rod, install the L-shaped pressure plate, repeat step 5), and then loosen the annular thin plate workpiece and perform natural aging for 5-10 days;

[0020] 7) Assemble the first threaded pressure rod and the L-shaped pressure plate again, clamp the annular thin plate workpiece on the base, and repeat steps 5) and 6) to perform plane finishing to obtain a thin plate annular finished workpiece.

[0021] The following steps are also included:

[0022] Remove the first threaded pressure rod and the L-shaped pressure plate, assemble the I-shaped pressure plate on the top surface of the thin plate annular finishing workpiece, and fix it to the large cylinder by passing the second bolt through the screw hole of the I-shaped pressure plate and the screw hole on the top end face of the large cylinder; at the same time, assemble the Z-shaped pressure plate, and the third threaded pressure rod vertically passes through the screw hole at the front end of the Z-shaped pressure plate and presses it on the top surface of the thin plate annular finishing workpiece, and the fourth screw pressure rod horizontally passes through the screw hole in the middle section of the Z-shaped pressure plate and presses it on the inner hole surface of the thin plate annular finishing workpiece, and the first bolt passes through the screw hole at the rear end of the Z-shaped pressure plate and the second screw hole on the bottom plate and is fixed to the bottom plate, and the tool is controlled to drill a hole on the end face of the thin plate annular finishing workpiece to complete the processing process of the end face hole to obtain a thin plate annular part.

[0023] When performing steps 5) and 6) for the first time, the tool is controlled to cut with a 0.2 mm margin each time, and the cutting parameters are: spindle speed n = 7 to 10 r / min, feed speed f = 0.3 to 0.5 mm / r.

[0024] In step 7), when repeating steps 5) and 6) to perform plane finishing, the tool cuts with a 0.1 mm allowance each time, and the cutting parameters are: spindle speed n = 8 to 12 r / min, feed speed f = 0.2 to 0.4 mm / r.

[0025] The difficulty in processing the inner hole of a thin plate annular part is to meet the high-precision requirements of the flatness of the thin plate part, and it is necessary to control the deformation during the processing to achieve a flatness of 0.05mm. The present invention designs a base to artificially increase the thickness of the thin plate workpiece, and converts the radial pressure on the thin plate part in the conventional clamping method into a circumferential direction, so that the machine tool clamping claws do not directly act on the workpiece. At the same time, multiple notches are set on the large cylinder that cooperates with the workpiece to release the processing stress. In addition, when processing different parts, the present invention designs different pressure plates to cooperate with the base to clamp different parts of the workpiece, thereby eliminating the extrusion force generated by the tool when processing different parts, and finally changes the tool path during processing to eliminate the influence of cutting heat and ensure the flatness of the product.

[0026] Beneficial effects:

[0027] 1) The present invention uses a special tooling in conjunction with a CNC vertical lathe for operation. The lathe jaw force no longer acts directly on the workpiece, but acts on the tooling, which then clamps the workpiece, thereby effectively eliminating workpiece deformation caused by clamping.

[0028] 2) When processing different parts of the workpiece, use different pressing plates to press different parts of the workpiece, so that the workpiece is evenly stressed and processing deformation is eliminated;

[0029] 3) Under the premise of cooperating with the tooling, adopt the turning method of forward and reverse feed, and cycle down at the same time to eliminate the deformation of the workpiece caused by cutting heat.

[0030] 4) The present invention has a simple operation method, can be operated using a CNC vertical lathe, effectively solves the deformation caused by cutting heat and clamping problems, has high processing accuracy (meets the high-precision requirement of flatness of 0.05 mm), meets the requirements of processing inner holes, planes and end face openings, has good reliability, high precision, low equipment investment and cost, and is suitable for the fine processing of large stainless steel thin plate annular parts with a diameter greater than 1500 mm and a thickness less than 20 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a three-dimensional diagram of the base of the present invention.

[0032] Figure 2 This is a three-dimensional diagram of the thin plate annular part obtained after processing according to the present invention.

[0033] Figure 3 It is a three-dimensional schematic diagram of the tooling and actual installation of the present invention.

[0034] Figure 4 This is a plan view of the installation structure when machining the inner hole of the present invention.

[0035] Figure 5 This is a schematic diagram of the installation structure plane when processing a plane according to the present invention.

[0036] Figure 6 This is a plan view of the installation structure when drilling a hole on the end face of the present invention.

[0037] Among them, 1-thin plate annular part, 1.1-inner hole, 1.2-opening, 2-base, 2.1-large hole, 2.2-small hole, 2.3-large cylinder, 2.4-small cylinder, 2.5-first screw hole, 2.6-second screw hole, 2.7-third screw hole, 2.8-notch, 2.9-bottom plate, 3-L-type pressure plate, 4-Z-type pressure plate, 5-I-type pressure plate, 6-first threaded pressure rod, 7-second threaded pressure rod, 8-third threaded pressure rod, 9-first bolt, 10-second bolt, 11-third bolt, 12-fourth threaded pressure rod.

[0038] A1-circular thin plate workpiece, B1-annular thin plate workpiece, C1-thin plate annular finishing workpiece. DETAILED DESCRIPTION

[0039] The following is a further explanation of the tooling of the present invention with reference to the accompanying drawings:

[0040] See also Figures 1-6The present invention provides a finishing tool for large stainless steel thin plate annular parts, comprising a base 2, the inner hole of the base 2 being a stepped hole with a larger upper portion and a smaller lower portion, comprising a large hole 2.1 in the upper section and a small hole 2.2 in the lower section, the diameter of the large hole 2.1 in the upper section being larger than the outer diameter of the annular part 1, and the diameter of the small hole 2.2 in the lower section being larger than the inner hole diameter of the annular part 1; the outer shape of the base 2 being a stepped cylinder with a larger upper portion and a smaller lower portion, comprising a large cylinder 2.3 in the upper section and a small cylindrical bolt 2.4 in the lower section; the clamping claws of a CNC vertical lathe can be clamped on the small cylinder 2.4 without directly acting on the workpiece, and the workpiece can be in a free state, thereby completely solving the deformation of the workpiece caused by clamping. The outer circumference of the large cylindrical body 2.3 is uniformly arranged with a plurality of first screw holes 2.5 (eight in this embodiment). The body of the large cylindrical body 2.3 is uniformly formed with a plurality of notches 2.8 (eight in this embodiment). The lower ends of the notches 2.8 are flush with the bottom surface of the large hole 2.1. The notches 2.8 facilitate observation and measurement of thickness changes of the thin plate annular component 1 during machining, and also allow for pressure relief. The diameter of the large hole 2.1 is 0.1-0.2 mm larger than the outer diameter of the annular component 1, leaving a certain clearance to accommodate the expansion of the workpiece due to heat generation.

[0041] The bottom surface of the small hole 2.2 of the base 2 is provided with a bottom plate 2.9, and the bottom plate 2.9 is evenly and annularly provided with a plurality of second screw holes 2.6 along the circumferential direction; it also includes an L-shaped pressing plate 3, and screw holes are provided at both ends of the L-shaped pressing plate 3.

[0042] The top end surface of the large cylinder 2.3 is also evenly provided with a plurality of third screw holes 2.7; it also includes an I-type pressure plate 5 and a Z-type pressure plate 4, one end of the I-type pressure plate 5 is provided with a screw hole, and both ends and the middle section of the Z-type pressure plate 4 are provided with screw holes.

[0043] The method for finishing large stainless steel thin plate annular parts of the present invention uses the above-mentioned tooling and is carried out in the following processing steps:

[0044] 1) See Figure 4 , assemble the circular thin plate workpiece A1 to be processed onto the base 2, so that the bottom surface of the circular thin plate workpiece A1 is completely in contact with the bottom surface of the large hole 2.1, and a gap of 0.1-0.2mm is left between the diameter of the circular thin plate workpiece A1 and the diameter of the large hole 2.1 of the base 2 to accommodate the expansion of the workpiece due to heat;

[0045] 2) Clamp the base 2, which holds the circular thin plate workpiece A1, onto a CNC vertical lathe. The jaws of the CNC vertical lathe clamp the small cylindrical body 2.4 of the base 2, not the workpiece itself. This allows the workpiece to be free, minimizing deformation caused by clamping.

[0046] 3) Pass the first threaded pressure rod 6 through the first screw hole 2.5 on the outer surface of the large cylinder 2.3 and press it against the outer surface of the circular thin plate workpiece A1 to fix the circular thin plate workpiece A1. An elastic gasket can be set on the contact surface. The force on the workpiece here is as follows: the pressure of the multiple first threaded pressure rods 6 on the outer circle (such as Figure 3 ) and the extrusion force of the machining tool on inner hole 1.1. At this point, the pressure of the first threaded pressure rod 6 can be adjusted to roughly equalize the extrusion force of the tool. This ensures that the workpiece is subjected to balanced pressure and does not deform. The tool is then controlled to carve inner hole 1.1 of the circular thin plate workpiece A1, completing the machining of inner hole 1.1 and obtaining an annular thin plate workpiece B1.

[0047] 4) See Figure 4 After the inner hole 1.1 is processed, the L-shaped pressing plate 3 is installed, and the first bolt 9 is passed through the screw hole of the lower section of the L-shaped pressing plate 3 and the screw hole on the bottom plate 2.9 to fix it to the bottom plate 2.9. Then, the second threaded pressing rod 7 is passed horizontally through the screw hole of the upper section of the L-shaped pressing plate 3 to press the inner hole surface of the annular thin plate workpiece B1. At this time, the force of the workpiece is as follows: the pressure of the outer circle of the multiple first threaded pressing rods 6 (such as Figure 4 ) and the pressure of the plurality of second threaded pressure rods 7 on the inner hole 1.1, thereby maintaining the balance of the workpiece;

[0048] 5) Controlling the tool to turn the upper end surface of the annular thin plate workpiece B1, the turning method is as follows: a) first moving the tool from the outer circle toward the inner hole 1.1 once, and then moving the tool from the inner hole 1.1 toward the outer circle once; repeating step a) at least once until the process allowance requirement is met; wherein, the tool is controlled to cut a 0.2mm allowance each time, and the cutting parameters are: spindle speed n = 7-10 rpm, feed rate f = 0.3-0.5 mm / min

[0049] 6) Then loosen the first threaded pressure rod 6, remove the L-shaped pressure plate 3, turn the annular thin plate workpiece B1 180 degrees, re-tighten the first threaded pressure rod 6, install the L-shaped pressure plate 3, repeat step 5), and then loosen the annular thin plate workpiece B1 and perform natural aging for 5-10 days;

[0050] 7) Reassemble the first threaded pressure rod 6 and the L-shaped pressure plate 3, clamp the annular thin plate workpiece B1 on the base 2, and repeat steps 5) and 6) for plane finishing, obtaining a thin annular finished workpiece C1 that meets the process dimensional thickness requirements. During the plane finishing process, the tool cuts with a 0.1 mm allowance each time, using the following cutting parameters: spindle speed n = 8-12 rpm, feed rate f = 0.2-0.4 mm / min.

[0051] 8) Remove the first threaded pressure rod 6 and the L-shaped pressure plate 3, and assemble the I-shaped pressure plate 5 on the top surface of the thin-plate annular finishing workpiece C1. The second bolt 10 is passed through the screw hole of the I-shaped pressure plate 5 and the third screw hole 2.7 on the top end face of the large cylinder 2.3 to fix it to the large cylinder 2.3. At the same time, assemble the Z-shaped pressure plate 4. The third threaded pressure rod 8 is passed vertically through the screw hole at the front end of the Z-shaped pressure plate 4 to press it against the top surface of the thin-plate annular finishing workpiece C1. The fourth bolt pressure rod 12 is passed horizontally through the screw hole in the middle section of the Z-shaped pressure plate 4 to press it against the surface of the inner hole 1.1 of the thin-plate annular finishing workpiece C1. The first bolt 9 is passed through the screw hole at the rear end of the Z-shaped pressure plate 4 and the second screw hole 2.6 on the bottom plate 2.9 to fix it to the bottom plate 2.9. By combining the Z-shaped pressure plate 4 with the I-shaped pressure plate 5, the force is evenly applied to both sides of the workpiece, preventing the workpiece from warping and deforming, which would damage the already processed flatness of the workpiece. Finally, the tool is controlled to drill a hole on the end face of the thin-plate annular finishing workpiece C1, completing the end face hole processing process and obtaining the thin-plate annular part 1.

[0052] The fixture of the present invention has excellent clamping performance and provides sufficient clamping force to prevent displacement between the workpiece and the fixture. The processing method of the present invention is convenient and reliable, effectively reducing deformation of thin-plate annular parts caused by clamping, metal cutting heat, and internal cutting stress during processing, while eliminating processing errors. The present invention achieves high processing efficiency and stable quality for high-precision thin-plate annular parts. The processing method of the present invention can process thin-plate annular parts with a diameter exceeding φ1500 mm and a thickness of less than 20 mm, achieving a flatness of 0.05 mm.

Claims

1. A method for finishing large stainless steel thin plate annular parts, characterized in that: Use a tooling, the tooling includes a base, the inner hole of the base is a stepped hole that is larger at the top and smaller at the bottom, including a large hole in the upper section and a small hole in the lower section, the diameter of the large hole in the upper section is larger than the outer diameter of the thin plate annular part, and the diameter of the small hole in the lower section is larger than the inner diameter of the thin plate annular part; the base has a stepped cylinder with larger and smaller holes at the top and lower sections, including a large cylinder in the upper section and a small cylinder in the lower section, and a plurality of first screw holes are evenly arranged on the outer surface of the large cylinder; the bottom surface of the small hole of the base is provided with a bottom plate, and the bottom plate is annularly and evenly provided with a plurality of second screw holes in the circumferential direction; it also includes an L-shaped pressing plate, both ends of the L-shaped pressing plate are provided with screw holes; the top end surface of the large cylinder is also evenly provided with a plurality of third screw holes; it also includes an I-shaped pressing plate and a Z-shaped pressing plate, one end of the I-shaped pressing plate is provided with a screw hole, and both ends and the middle section of the Z-shaped pressing plate are provided with screw holes; Use the above tooling to carry out the following processing steps in sequence: 1) Assemble the circular thin plate workpiece to be processed onto the base so that the bottom surface of the circular thin plate workpiece fits into the bottom surface of the large hole, and the gap between the diameter of the circular thin plate workpiece and the diameter of the large hole of the base is 0.1-0.2mm; 2) Clamp the base with the circular thin plate workpiece onto the CNC vertical lathe, and the jaws of the CNC vertical lathe clamp the small cylinder of the base; 3) Passing a first threaded pressing rod through a first screw hole on the outer circumference of the large cylinder and pressing it against the outer circumference of the circular thin plate workpiece to fix the circular thin plate workpiece, and controlling a tool to lathe an inner hole of the circular thin plate workpiece to complete the inner hole machining of the circular thin plate workpiece and obtain an annular thin plate workpiece; 4) After the inner hole is processed, the L-shaped pressing plate is installed and fixed to the bottom plate with a first bolt passing through the screw hole of the lower section of the L-shaped pressing plate and the second screw hole of the bottom plate. Then, a second threaded pressing rod is passed horizontally through the screw hole of the upper section of the L-shaped pressing plate to press against the inner hole surface of the annular thin plate workpiece; 5) Controlling the tool to turn the upper end surface of the annular thin plate workpiece by: a) first turning the tool once from the outer circle toward the inner hole, and then turning the tool once from the inner hole toward the outer circle; repeating step a) at least once until the process allowance requirement is met; 6) Then loosen the first threaded pressure rod, remove the L-shaped pressure plate, turn the annular thin plate workpiece 180 degrees, re-tighten the first threaded pressure rod, install the L-shaped pressure plate, repeat step 5), and then loosen the annular thin plate workpiece and carry out natural aging for 5-10 days; 7) Assembling the first threaded pressure rod and the L-shaped pressure plate again, clamping the annular thin plate workpiece on the base, and repeating steps 5) and 6) to perform plane finishing to obtain a thin plate annular finished workpiece; 8) Disassemble the first threaded pressure rod and the L-shaped pressure plate, assemble the I-shaped pressure plate on the top surface of the thin plate annular finishing workpiece, and fix it to the large cylinder by passing the second bolt through the screw hole of the I-shaped pressure plate and the first screw hole on the top end face of the large cylinder; at the same time, assemble the Z-shaped pressure plate, and the third threaded pressure rod vertically passes through the screw hole at the front end of the Z-shaped pressure plate to press on the top surface of the thin plate annular finishing workpiece, and the fourth screw pressure rod horizontally passes through the screw hole in the middle section of the Z-shaped pressure plate to press on the inner hole surface of the thin plate annular finishing workpiece, and the first bolt passes through the screw hole at the rear end of the Z-shaped pressure plate and the second screw hole on the bottom plate to fix it to the bottom plate, and control the tool to drill a hole on the end face of the thin plate annular finishing workpiece to complete the processing process of the end face hole to obtain a thin plate annular part.

2. The method for finishing large stainless steel thin plate annular parts according to claim 1, characterized in that: When performing steps 5) and 6) for the first time, control the tool to cut with a 0.2mm allowance each time, and the cutting parameters are: spindle speed n=7~10r / min, feed speed f=0.3~0.5mm / r.

3. The method for finishing large stainless steel thin plate annular parts according to claim 1, characterized in that: In step 7), when repeating steps 5) and 6) for plane finishing, the tool cuts with a 0.1mm allowance each time, and the cutting parameters are: spindle speed n = 8~12r / min, feed speed f = 0.2~0.4mm / r.

4. A tool for the finishing method of large stainless steel thin plate annular parts according to any one of claims 1 to 3, characterized in that: The cam is provided with a plurality of screw holes at the top and the bottom, and the cam is provided with a plurality of screw holes at the top and the bottom, and the cam is provided with a plurality of screw holes at the top and the bottom, respectively.

5. The tooling according to claim 4, characterized in that: A plurality of notches are evenly opened on the body of the large cylinder, and the lower ends of the notches are flush with the bottom surface of the large hole.

6. The tooling according to claim 4, characterized in that: The diameter of the large hole is 0.1-0.2 mm larger than the outer diameter of the thin plate annular part.

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