Ultrathin titanium hemisphere machining method

Abstract

The invention provides an ultrathin titanium hemisphere machining method which comprises the procedures of front and back side rough turning, process groove milling and drilling, front and back side semi-finish turning, front and back side finish turning, polishing, removal of molybdenum wires from a process table, plane grinding and the like, and special tires need to be adopted in the semi-finish turning and finish turning procedures to complete machining. The machining method is suitable for common metal materials including titanium alloy, and the problems that an ultrathin hemispherical product is large in machining difficulty, machining deformation, out-of-tolerance in size, poor in smoothness, incapable of being clamped and the like can be solved. By the adoption of the machining method, it can be guaranteed that the ultra-thin titanium hemisphere product meets the precision required by design, machining difficulty is lowered, product quality stability and machining efficiency are improved, and tool abrasion is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical manufacturing, and in particular relates to a method for processing an ultra-thin titanium hemisphere. Background Art

[0002] Titanium hemisphere is an important precision component in the transmission system of shipbuilding heavy industry. The product structure is hemispherical, the wall thickness of the hemisphere is 0.8mm, the surface roughness of the inner and outer walls is required to be 0.4, the wall thickness tolerance is ±0.02, the roundness of the outer wall of the hemisphere is required to be 0.01, and the flatness of the end face is required to be 0.01. Figure 1a and 1b As shown. Titanium alloys have been widely used in aerospace, shipbuilding, and defense industries because of their high strength, low density, good corrosion resistance, and high heat resistance. However, due to the low thermal conductivity, low elastic modulus, and high chemical activity of titanium alloys, their cutting performance is poor, heat dissipation is difficult during cutting, and the material rebounds a lot, which can easily cause tool adhesion and wear. Chatter marks are prone to appear on the machined surface. Due to their high chemical activity, they are prone to chemical reactions with gas impurities such as hydrogen and oxygen in the air to form a surface hardened layer, which further aggravates tool wear. Therefore, titanium alloy processing has high requirements for tools, cutting parameters, and processing methods, and is difficult to process. When conventional process methods are used to process ultra-thin titanium hemispheres, the product is severely deformed, the size deviation is large, and the surface finish is poor. The design accuracy cannot be guaranteed at all, and the tool wears quickly and the tool life is short. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] The invention provides a method for processing an ultra-thin titanium hemisphere, so as to solve the technical problems of easy deformation, easy size deviation, poor finish, low processing precision and fast tool wear during processing of the ultra-thin titanium hemisphere.

[0005] (II) Technical solution

[0006] In order to solve the above technical problems, the present invention proposes a method for processing an ultra-thin titanium hemisphere, which includes rough turning of the front and back surfaces, processing grooves and drilling, semi-finishing turning of the front and back surfaces, finishing turning of the front and back surfaces, polishing, removing the process table and grinding the plane.

[0007] Furthermore, the ultra-thin titanium hemisphere processing method specifically includes the following steps:

[0008] S1. Rough turning of the front and back sides: Rough turning is performed on the front and back sides of the product blank to obtain a rough turned workpiece. A process table is left when the product blank is rough turned;

[0009] S2. Milling process grooves and drilling holes: Multi-point grooves are made on the process table of the rough turning workpiece to release the internal stress of processing; process holes are drilled to facilitate assembly with the tire;

[0010] S3. Semi-finish turning of the front and back sides: semi-finish turning is performed on the front and back sides of the rough-turned workpiece to obtain a semi-finished workpiece;

[0011] S4. Finish turning of the front and back sides: Finish turning the front and back sides of the semi-finished workpiece to obtain a finished workpiece;

[0012] S5. Polishing: Polish the finished workpiece;

[0013] S6. Remove the process table on the workpiece;

[0014] S7. Grinding plane: Grind the end surface of the workpiece after removing the process table.

[0015] Furthermore, the product blank is a Φ150 / TC6 bar.

[0016] Furthermore, in step S1, the inner and outer wall reserves of the hemisphere are 1 mm each; the cutting line speed is 150 m / min, the back cutting depth is 1.5 mm, and the feed rate is 0.15 mm / r.

[0017] Furthermore, in step S3, when processing the concave surface, the rough-turned workpiece and the concave semi-finished tire are assembled and clamped; when processing the convex surface, the rough-turned workpiece and the convex semi-finished tire are assembled and clamped.

[0018] Furthermore, in step S3, the inner and outer walls are each left with a reserve of 0.3 mm; the cutting line speed is 180 m / min, the back cutting depth is 0.3 mm, and the feed rate is 0.12 mm / r.

[0019] Furthermore, in step S4, when the concave surface is processed, the semi-finished workpiece and the concave surface finishing tire are assembled and clamped; when the convex surface is processed, the semi-finished workpiece and the convex surface finishing tire are assembled and clamped.

[0020] Furthermore, in step S4, the wall thickness is processed to the final product size; the cutting line speed is 200m / min, the back cutting depth is 0.1mm, and the feed rate is 0.06mm / r.

[0021] Furthermore, in step S5, the workpiece is polished by brush polishing on a lathe, and the surface roughness of the inner and outer walls of the product is 0.4.

[0022] Furthermore, in step S6, the process table on the workpiece is removed by molybdenum wire cutting.

[0023] (III) Beneficial effects

[0024] The present invention proposes a method for processing an ultra-thin titanium hemisphere, including rough turning of the front and back sides - milling process grooves and drilling - semi-finishing turning of the front and back sides - finishing turning of the front and back sides - polishing - molybdenum wire removal of the process table - grinding plane and other processes, wherein the semi-finishing turning and finishing turning processes need to be completed by special tires. This processing method is suitable for general metal materials including titanium alloys, and can solve the problems of high processing difficulty, processing deformation, dimensional tolerance, poor finish, and inability to install ultra-thin hemispherical products. The use of this processing method can ensure that the ultra-thin titanium hemisphere product meets the design accuracy requirements, reduce processing difficulty, improve product quality stability and processing efficiency, and reduce tool wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a This is the main view of the titanium hemisphere. Figure 1b for Figure 1a AA section view;

[0026] Figure 2 This is a rough turning process diagram of the concave surface of the ultra-thin titanium hemisphere in the present invention;

[0027] Figure 3 This is a process diagram of rough turning the convex surface of the ultra-thin titanium hemisphere in the present invention;

[0028] Figure 4a This is the front view of the drilling and milling process of the ultra-thin titanium hemisphere process table in the present invention. Figure 4b for Figure 4a AA section view;

[0029] Figure 5 This is a process diagram of semi-finishing turning of the concave surface of the ultra-thin titanium hemisphere in the present invention;

[0030] Figure 6 This is a process diagram of semi-finishing turning of the convex surface of the ultra-thin titanium hemisphere in the present invention;

[0031] Figure 7 This is a process diagram of finishing the concave surface of the ultra-thin titanium hemisphere in the present invention;

[0032] Figure 8 This is a process diagram for finishing the convex surface of an ultra-thin titanium hemisphere in the present invention;

[0033] Fig. 9 This is a process diagram of the surface polishing of the ultra-thin titanium hemisphere in the present invention;

[0034] Fig.10 It is a process diagram of the ultra-thin titanium hemispherical molybdenum wire cutting process table in the present invention (indicating cutting from the middle, and the thick solid line in the figure indicates the processing surface of this step);

[0035] Fig.11 This is a process diagram for grinding the plane of the ultra-thin titanium hemisphere in the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0037] This embodiment provides a method for processing an ultra-thin titanium hemisphere, the method comprising the following steps:

[0038] S1. Rough turning of the front and back surfaces: The product blank is a Φ150 / TC6 bar stock. The front and back surfaces of the blank are rough turned to obtain a rough turned workpiece. The concave rough turning and convex rough turning processes are as follows: Figure 2 and 3 As shown. For the convenience of clamping, an 8mm process table is left when the product blank is rough turned, and the inner and outer walls of the hemisphere are left with 1mm each. The cutting line speed is 150m / min, the back cutting depth is 1.5mm, the feed rate is 0.15mm / r, and the tools used include a 60° external turning tool and a 35° inner hole sharp tool. The higher the cutting parameters, the more serious the tool wear. Low cutting parameters affect the processing efficiency. The above cutting parameters used in this method can take into account both small tool wear and high processing efficiency.

[0039] S2. Milling process grooves and drilling holes: slots are evenly distributed at three points on the process table of the rough turning workpiece to release the internal stress generated during the processing and prevent the workpiece from deformation. At the same time, 6 Φ5.5mm countersunk process holes are evenly distributed on the front and back sides of the process table to be combined with the front and back tires through M5 screws. The countersunk holes can ensure that the end face can still be processed after the workpiece and the tire are combined. When the workpiece is semi-finished and finished, the height dimension of the product itself (60.8±0.02mm) cannot be measured, that is, the dimension from the end face to the top of the outer wall of the hemisphere. The height dimension of the workpiece can be indirectly guaranteed by controlling the thickness dimension tolerance of the process table, such as Figure 4a and 4b shown.

[0040] S3. Semi-finishing turning of the front and back surfaces: semi-finishing turning is performed on the front and back surfaces of the rough-turned workpiece to obtain a semi-finished workpiece. The concave semi-finishing turning and convex semi-finishing turning processes are as follows: Figure 5 and 6 As shown. When processing the concave surface, the workpiece is assembled and clamped with the concave semi-finishing tire 1; when processing the convex surface, the workpiece is assembled and clamped with the convex semi-finishing tire 2, and the inner and outer walls are left with 0.3mm. The cutting line speed is 180m / min, the back cutting depth is 0.3mm, the feed rate is 0.12mm / r, and the tools used include 35° external circle sharp cutter and 35° inner hole sharp cutter. The tire surface fits closely with the workpiece surface. During processing, the tire can provide the workpiece with a support force opposite to the cutting force, preventing the workpiece from deformation or chattering, and ensuring the product size accuracy and surface finish.

[0041] S4. Finish turning of the front and back surfaces: Finish turning the front and back surfaces of the semi-finished workpiece to obtain a finished workpiece. The concave surface finishing and convex surface finishing processes are as follows: Figure 7and 8 As shown. When processing the concave surface, the workpiece is assembled and clamped with the concave surface finishing tire 3; when processing the convex surface, the workpiece is assembled and clamped with the convex surface finishing tire 4, and the wall thickness is processed to the final size. The cutting line speed is 200m / min, the back cutting amount is 0.1mm, the feed rate is 0.06mm / r, and the tools used include 35° external circle sharp tool and 35° inner hole sharp tool.

[0042] S5. Polishing: Polish the workpiece on the lathe using a brush to ensure that the surface roughness of the inner and outer walls of the workpiece is 0.4. Fig. 9 shown.

[0043] S6. Remove the process table on the workpiece by molybdenum wire cutting, and leave 0.02 on the end face of the workpiece. Fig.10 shown.

[0044] S7. Grinding plane: Grind the end surface of the product after removing the process table to the final size to ensure the height size and end surface finish of the product, and obtain the final ultra-thin titanium hemisphere product, such as Fig.11 shown.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for processing ultra-thin titanium hemispheres, It is characterized in that The ultra-thin titanium hemisphere processing method includes front and back rough turning, processing grooves and drilling, front and back semi-finishing turning, front and back finishing turning, polishing, removing process tables and grinding plane processes.

2. The method for processing an ultra-thin titanium hemisphere as claimed in claim 1, It is characterized in that The ultra-thin titanium hemisphere processing method specifically comprises the following steps: S1. Rough turning of the front and back sides: Rough turning is performed on the front and back sides of the product blank to obtain a rough turned workpiece. A process table is left when the product blank is rough turned; S2. Milling process grooves and drilling holes: Multi-point grooves are made on the process table of the rough turning workpiece to release the internal stress of processing; process holes are drilled to facilitate assembly with the tire; S3. Semi-finish turning of the front and back sides: semi-finish turning is performed on the front and back sides of the rough-turned workpiece to obtain a semi-finished workpiece; S4. Finish turning of the front and back sides: Finish turning the front and back sides of the semi-finished workpiece to obtain a finished workpiece; S5. Polishing: Polish the finished workpiece; S6. Remove the process table on the workpiece; S7. Grinding plane: Grind the end surface of the workpiece after removing the process table.

3. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that The product blank is Φ150 / TC6 bar.

4. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that In step S1, the inner and outer wall reserves of the hemisphere are 1 mm each; the cutting line speed is 150 m / min, the back cutting depth is 1.5 mm, and the feed rate is 0.15 mm / r.

5. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that In step S3, when processing the concave surface, the rough-turned workpiece and the concave semi-finished tire are assembled and clamped; when processing the convex surface, the rough-turned workpiece and the convex semi-finished tire are assembled and clamped.

6. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that In step S3, the inner and outer walls are left with a reserve of 0.3 mm each; the cutting line speed is 180 m / min, the back cutting depth is 0.3 mm, and the feed rate is 0.12 mm / r.

7. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that In step S4, when the concave surface is processed, the semi-finished workpiece and the concave surface finishing tire are assembled and clamped; when the convex surface is processed, the semi-finished workpiece and the convex surface finishing tire are assembled and clamped.

8. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that In step S4, the wall thickness is processed to the final product size; the cutting line speed is 200m / min, the back cutting depth is 0.1mm, and the feed rate is 0.06mm / r.

9. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that In step S5, the workpiece is polished by brush polishing on a lathe, and the surface roughness of the inner and outer walls of the product is 0.

4.

10. The method for processing an ultra-thin titanium hemisphere as claimed in claim 2, It is characterized in that In step S6, the process table on the workpiece is removed by molybdenum wire cutting.

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