A manufacturing method of a grid fin

Abstract

The object of the present invention is to provide a manufacturing method for grid rudders, including: material selection - alloy forging - re-inspection of the properties of forgings - tool selection - rough machining of grid rudders - selection of the feed per pass and spindle speed for rough machining - selection of the feed rate for rough machining - stress relief heat treatment - selection of the feed per pass and spindle speed for semi-finishing machining - selection of the feed rate for semi-finishing machining - stress relief heat treatment - selection of the feed per pass and spindle speed for finishing machining - selection of the feed rate for finishing machining - precision grinding of the plane - finishing machining of the depression - drilling and tapping of positioning holes and threaded holes - tapping - surface finishing - penetration and dimensional inspection. By selecting reasonable processing procedures, machining process parameters, heat treatment process parameters and optimizing the design of the rough machining model structure, the present invention improves the processing efficiency, processing quality and product qualification rate of grid rudders.

Description

Technical Field

[0001] The present invention relates to a manufacturing method for grid fins, belonging to the technical field of machining. Background Art

[0002] Grid fins are widely used in missiles, launch vehicles, and various aircraft. As a special form of lifting surface, a grid fin is a spatial multi-lifting surface system composed of an external frame and numerous internal thin grid walls arranged in a frame or honeycomb pattern. Its feature is that many lifting surfaces can be arranged within a relatively small span dimension to obtain a large lift, which can provide a control force for the stable flight and maneuver control of the aircraft.

[0003] The deficiencies of the prior art are as follows: The machining of grid fins adopts non-standard machining by wire cutting process, resulting in a high scrap rate of products. The surface roughness of the products after wire cutting is relatively low, and it is difficult to ensure product accuracy with non-standard machining. In addition, the impact load is also a severe test for the safety of grid fins, which leads to the disadvantages of high manufacturing quality requirements, long cycle, high cost, low installation efficiency, and poor safety during use for grid fins. With the continuous improvement of technology, the traditional wire cutting method can no longer meet the requirements of this important component of grid fins. Therefore, it is crucial to optimize the processes and parameters for grid fin parts to form a complete manufacturing method for grid fins. Summary of the Invention

[0004] The present invention provides a manufacturing method for grid fins to solve the above deficiencies.

[0005] The technical solution of the present invention is as follows:

[0006] A manufacturing method for grid fins, characterized by comprising the following steps:

[0007] (1) Rough machining of the part blank:

[0008] First, rough machine the outer frame structure of the part, and then rough machine the internal grid structure. The rough machining of the grid structure is as follows: First, mill round holes, and then expand and mill the internal shape;

[0009] (2) Perform stress relief annealing treatment on the part;

[0010] (3) Semi-finish machining of the part:

[0011] First, perform semi-finish milling on the outer frame structure, and then perform semi-finish milling on the internal grid structure;

[0012] (4) Finish machining of the part:

[0013] First, perform finish milling on the outer frame structure of the part, and then perform finish milling on the internal grid structure;

[0014] (5) Finish precision grinding the reference surface of the part;

[0015] (6) Finish precision milling the sunken mounting surface of the part;

[0016] (7) Semi-finish the connecting seat structure of the part: first semi-finish the plane, and then machine the side surface;

[0017] (8) Finish machining the connecting seat structure of the part: first finish the plane, and then machine the side surface;

[0018] (9) Machine holes in the connecting seat structure of the part: first punch the center point, then drill, ream, and finally bore the hole.

[0019] The method described in the present invention is particularly suitable for preparing a frame-type grid rudder. The entire grid rudder is a single-axisymmetric regular hexagon (as Figure 1 shown). Since the grids are distributed in an oblique cross pattern, the grids connected to the outer frame are triangular grids, and the grids not connected to the outer frame are quadrilateral grids.

[0020] The specific preparation process is as follows:

[0021] In step (1), before rough machining, 100% ultrasonic flaw detection shall be carried out on the forging blank according to GJB2218-1994. Subsequently, the mechanical property requirements for the titanium plate after forging are that the ultimate strength in the main direction and the rolling direction shall not be less than 895 MPa, the yield limit shall not be less than 825 MPa, and the elongation shall not be less than 10%. Then, 100% penetrant inspection shall be carried out on the forging according to GJB2367A-2005.

[0022] In step (1), rough machining is carried out in two steps:

[0023] The first step: The feed per pass for rough machining the outer frame is 4-6 mm, the spindle speed for rough machining the outer frame is 500-800 r / min, the feed rate for rough machining the outer frame is 1-1.5 m / min, the unilateral machining allowance is kept at 3-5 mm, and the surface roughness is 6.3-12.5 μm; the feed per pass for rough machining the grids is 0.5-1 mm, the spindle speed for rough machining the grids is 600-800 r / min, the feed rate for rough machining the grids is 1-1.3 m / min, the unilateral machining allowance is kept at 3-5 mm, and the surface roughness is 6.3-12.5 μm; The method of milling holes first and then milling the profile is adopted. First, machine the round holes of the innermost triangular grids, then machine the round holes of the outermost triangular grids, and the round holes of the triangular grids on the left and right sides respectively. Subsequently, machine the round holes of the quadrilateral grids in three times from the outside to the inside. This machining sequence can minimize the influence of the stress generated by material removal on the part accuracy;

[0024] Step 2: For rough machining the outer side of the outer frame, the feed per pass is 2 - 4 mm, the spindle speed is 500 - 800 r / min, the feed rate is 1 - 1.5 m / min, the unilateral machining allowance is kept at 1.5 - 3 mm, and the surface roughness is 6.3 - 12.5 μm; for rough machining the grid, the feed per pass is 0.05 - 0.1 mm, the spindle speed is 600 - 800 r / min, the feed rate is 1.3 - 1.7 m / min, the unilateral machining allowance is kept at 1.5 - 3 mm, and the surface roughness is 6.3 - 12.5 μm. When rough machining the grid, the blank is machined into the grid shape in three sequential passes from the outside to the inside, and the connections inside and outside the grid are all machined into rounded corners to ensure smooth transition between regions.

[0025] In step (2), the stress relief annealing treatment is specifically as follows: The temperature is steadily increased at a rate of 150 °C / h, and the furnace is heated to 600 - 700 °C, and the holding time is 4 - 8 h.

[0026] In step (3), semi-finishing is carried out in two steps:

[0027] First step: For semi-finishing the outer frame, the feed per pass is 3 - 5 mm, the spindle speed is 500 - 800 r / min, the feed rate is 1 - 1.3 m / min, and the surface roughness is 3.2 - 6.3 μm; for semi-finishing the inner wall of the grid, the feed per pass is 0.5 - 1 mm, the spindle speed is 500 - 800 r / min, the feed rate is 1.3 - 1.5 m / min, the surface roughness is 3.2 - 6.3 μm, the unilateral machining allowance is kept at 1.5 - 3 mm, the machining depth is half of the part thickness. The semi-finishing sequence is to first machine the inner wall of the outermost triangular grid, then machine the inner walls of the triangular grids on the left and right sides, then machine the outermost row of quadrilateral grids, and sequentially machine inwards, and the innermost quadrilateral grid is machined symmetrically, and finally the innermost triangular grid is machined symmetrically;

[0028] Second step: For semi-finishing the inner wall of the grid, the feed per pass is 0.3 - 0.5 mm, the spindle speed is 500 - 800 r / min, the feed rate is 1.3 - 1.5 m / min, the surface roughness is 3.2 - 6.3 μm, the unilateral machining allowance is kept at 1.5 - 3 mm, the machining depth is the part thickness. The machining sequence is to first machine the inner wall of the outermost triangular grid, then sequentially machine the inner walls of two rows of quadrilateral grids inwards, then machine the inner walls of the triangular grids on the left and right sides, then sequentially machine the inner walls of the quadrilateral grids inwards row by row, the innermost quadrilateral grid is machined symmetrically, then the inner wall of the innermost triangular grid is machined symmetrically, and finally all the inner walls of the triangular grids are chamfered in the order from the outside to the inside.

[0029] After step (3) and before step (4), the parts may be annealed again at a holding temperature of 600-700° C. for 4-8 hours.

[0030] In step (4), the finishing method is:

[0031] The finishing of the outer frame is divided into three feeds, and the single-side machining allowances of each pass are 2mm, 0.35mm and 0.1mm respectively. The spindle speed of the finishing frame is 500-800r / min, the finishing feed speed is 1-1.3m / min, the surface roughness is 3.2-6.3μm, and the cutting depth is half of the total thickness of the grid rudder. The advantage of using three feeds is that the internal stress after material removal can be reduced. The gradual reduction of the feed amount can not only reduce the friction heat generated by the removal of material, but also improve the surface roughness; the feed amount of each pass for finishing the inner wall of the grid is 1-2m m, spindle speed 500-800r / min, feed speed 1-1.3m / min, surface roughness 1.6-3.2μm, single-side machining allowance maintained at 0.75-1.25mm, cutting depth half of the total thickness of the grid rudder, the machining sequence is to first machine the inner wall of the outermost triangular grid rudder, then machine the inner walls of two rows of quadrilateral grids inwards, then machine the inner walls of the left and right triangles, then machine the inner walls of the quadrilateral grids inwards in sequence, the innermost quadrilateral grid inner wall is machined symmetrically, and finally the innermost triangular grid inner wall is machined;

[0032] The outer frame of the grid rudder is finely plane-machined with a knife. The feed amount for each pass of fine machining of the outer frame plane is 0.5-1mm. The spindle speed for fine machining of the outer frame plane is 500-800r / min, the feed speed is 1-1.3m / min, and the surface roughness is 1.6-3.2μm. The inner wall of the grid is finely plane-machined with a knife. The parameters for fine machining of the inner wall of the grid are the same as those for fine machining of the outer frame plane. The processing is carried out three times from the outside to the inside.

[0033] Turn over and process the other side using the above finishing method.

[0034] In step (5), the grid rudder reference surface is finely ground to ensure that the shape and position tolerance requirements and the subsequent assembly accuracy requirements are met as required.

[0035] In step (6), the innermost part of the grid rudder is connected to the rudder shaft, and this part is called the grid rudder connecting seat, and this part is subjected to a sinking process.

[0036] In step (7), first use a large cutter for semi-finishing the plane depression, and then select a small cutter for semi-finishing the side wall. The feed per pass for semi-finishing the plane depression is 0.5 - 1 mm, the spindle speed is 800 - 1000 r / min, the feed rate is 1.3 - 1.5 m / min, and the unilateral machining allowance is maintained at 0.3 - 1 mm; the feed per pass for semi-finishing the side wall is 1 - 2 mm, the spindle speed is 800 - 1000 r / min, the feed rate is 1.3 - 1.5 m / min, and the unilateral machining allowance is maintained at 0.5 - 1 mm, and the surface roughness is 1.6 - 3.2 μm.

[0037] In step (8), first machine the plane and then the side. The machining is completed in two times using the method of first using a large cutter and then a small cutter; the feed per pass for finishing the plane is 0.2 - 0.5 mm, the spindle speed is 800 - 1000 r / min, and the feed rate is 1.3 - 1.5 m / min; the feed per pass for finishing the side is 1 - 2 mm, the spindle speed is 800 - 1000 r / min, and the feed rate is 1.3 - 1.5 m / min;

[0038] Select a small cutter to trim the plane of the innermost outer frame of the grid rudder, and then select a large cutter to finish trimming the plane of the grid rudder outer frame. The feed per pass for finishing trimming with the small cutter is 0.1 - 0.3 mm, and the feed per pass for finishing trimming with the large cutter is 0.3 - 0.5 mm. The spindle speeds for finishing trimming are both 500 - 800 r / min, and the feed rates for finishing trimming are both 1 - 1.3 m / min.

[0039] In step (9), the assembly method of the grid rudder and the rudder shaft is mechanical connection. It is necessary to machine positioning holes on the grid rudder connecting seat. The holes are divided into two categories, one is the positioning hole and the other is the threaded hole; for machining the positioning hole, first mark points, then drill, ream, and finally bore; for machining the threaded hole, first mark points, then drill and ream; the spindle speed for drilling is 500 - 800 r / min, and the feed rate is 1.3 - 1.5 m / min; the reaming is carried out by milling, the feed per pass for reaming is 0.1 - 0.3 mm, the spindle speed is 500 - 800 r / min, and the feed rate is 1 - 1.3 m / min; the feed per pass for boring is 0.05 - 0.1 mm, the spindle speed is 800 - 1000 r / min, and the feed rate is 1 - 1.3 m / min. In order to ensure the installation accuracy, the positioning holes are all made by matching, and finally tap the threaded holes.

[0040] Surface finishing: Grind and polish the surface of the machined grid rudder, and the final part is obtained after passing the inspection.

[0041] The beneficial effects of the present invention are:

[0042] 1. The present invention provides a complete processing and manufacturing process plan for grid rudders. Firstly, in terms of material treatment, the material treatment method provided by the present invention fully meets the safety performance requirements during product use.

[0043] 2. The present invention effectively reduces the processing stress of grid rudders and improves the processing efficiency by controlling the entire process of heat treatment technology and machining processes.

[0044] 3. The present invention greatly improves the product qualification rate and effectively solves problems such as low product dimensional accuracy, long manufacturing cycle, and high production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the structure of the grid rudder prepared in Example 1 of the present invention.

[0046] Figure 2 It is a process flow chart of Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0047] The present invention will be further described in detail below with reference to the accompanying drawings.

[0048] As Figure 1 shown is a schematic diagram of the structure of the grid rudder prepared in the embodiment of the present invention. The grid rudder is composed of an external frame and an internal grid, and the internal grid is of a frame type.

[0049] The present invention improves the processing efficiency, processing quality, and product qualification rate of grid rudders by selecting reasonable processing processes, machining process parameters, heat treatment process parameters, and optimizing the design of rough machining model structures. It includes: material selection - alloy forging - re-inspection of forging properties - tool selection - rough machining of grid rudders - selection of feed per pass and spindle speed for rough machining - selection of feed rate for rough machining - stress relief heat treatment - selection of feed per pass and spindle speed for semi-finishing - selection of feed rate for semi-finishing - stress relief heat treatment - selection of feed per pass and spindle speed for finishing - selection of feed rate for finishing - precision grinding of plane - finishing of depression - drilling and tapping of positioning holes and threaded holes - tapping - surface finishing - penetration and dimensional inspection.

[0050] Example

[0051] Samples are taken from titanium alloy materials, and their chemical compositions and mechanical properties are detected to meet the usage requirements.

[0052] The alloy of this material is forged, and the forging blank is subjected to 100% ultrasonic flaw detection as required. Subsequently, mechanical property sampling and detection are carried out on the forging at specified positions. The ultimate strength in the main direction and rolling direction is not less than 895 MPa, the yield limit is not less than 825 MPa, and the elongation is not less than 10%. Then, the forging is subjected to 100% penetrant inspection as required.

[0053] (1) Rough machine the blank after forging to form the outer frame and grid. For rough machining of the outer frame, the feed per pass is 5 mm, the spindle speed for rough machining the outer shape is 500 r / min, the feed rate for rough machining the outer frame is 1 m / min, the unilateral machining allowance is kept at 3 mm, and the surface roughness is 12.5 μm. For rough machining of the grid, the feed per pass is 0.5 mm, the spindle speed for rough machining the grid is 600 r / min, the feed rate for rough machining the grid is 1.2 m / min, the unilateral machining allowance is kept at 3 mm, and the surface roughness is 12.5 μm. For rough machining of the outer shape, the feed per pass is 3 mm, the spindle speed for rough machining the outer shape is 500 r / min, the feed rate for rough machining the outer shape is 1.2 m / min, the unilateral machining allowance is kept at 2 mm, and the surface roughness is 12.5 μm. For rough machining of the grid, the feed per pass is 0.1 mm, the spindle speed for rough machining the grid is 600 r / min, the feed rate for rough machining the grid is 1.5 m / min, the unilateral machining allowance is kept at 2 mm, and the surface roughness is 12.5 μm.

[0054] (2) Perform stress relief annealing on the rough machined parts: Heat the furnace with a heating rate of 150 °C / h to 650 °C ± 10 °C, and hold for 8 h.

[0055] (3) Perform semi-finishing on the rough machined parts after stress relief heat treatment: For semi-finishing the outer frame, the feed per pass is 3 mm, the spindle speed for semi-finishing the outer frame is 500 r / min, the feed rate for semi-finishing the outer frame is 1 m / min, and the surface roughness is 6.3 μm. For semi-finishing the inner wall of the grid, the feed per pass is 0.5 mm, the spindle speed for semi-finishing the inner wall of the grid is 500 r / min, the feed rate for semi-finishing the inner wall of the grid is 1.3 m / min, the surface roughness is 6.3 μm, and the unilateral machining allowance is kept at 2 mm. Then further semi-finish the inner wall of the grid. The feed per pass for semi-finishing is 0.5 mm, the spindle speed for semi-finishing is 500 r / min, the feed rate for semi-finishing is 1.3 m / min, the surface roughness is 6.3 μm, and the unilateral machining allowance is kept at 2 mm.

[0056] Perform bending stress annealing on the semi-finished parts: Heat the furnace with a heating rate of 140 °C / h to 650 °C ± 10 °C, and hold for 6 h.

[0057] (4) Finish machining the parts after stress relief heat treatment: The unilateral machining allowance for each pass is 2 mm, 0.35 mm, and 0.1 mm respectively. The spindle speed for finish machining the outer frame is 500 r / min, the feed rate for finish machining is 1 m / min, the surface roughness is 6.3 μm, and the cutting depth is half of the total thickness of the grid rudder; The feed per pass for finish machining the inner wall of the grid is 1.5 mm, the spindle speed for finish machining the inner wall of the grid is 500 r / min, the feed rate for finish machining the inner wall of the grid is 1 m / min, the surface roughness is 3.2 μm, the unilateral machining allowance is maintained at 1 mm, and the cutting depth is half of the total thickness of the grid rudder; Use a small tool to finish the flat surface of the grid rudder outer frame. The feed per pass for finish machining the outer frame plane is 0.5 mm, the spindle speed for finish machining the outer frame plane is 500 r / min, the feed rate for finish machining the outer frame plane is 1 m / min, and the surface roughness is 3.2 μm.

[0058] Turn it over and machine the other side using the above finish machining method.

[0059] (5) Precision grinding the plane: Precision grind the reference plane of the grid rudder to ensure that the geometric tolerance requirements are met as required and the subsequent assembly accuracy requirements are satisfied.

[0060] (6) Pocket machining: The innermost part of the grid rudder is connected to the rudder shaft, and this part is called the grid rudder connection seat. Machine this part.

[0061] (7) Semi-finish machining the grid rudder connection seat part: The feed per pass for semi-finish machining the plane pocket is 0.5 mm, the spindle speed for semi-finish machining the plane pocket is 800 r / min, the feed rate for semi-finish machining the plane pocket is 1.3 m / min, and the unilateral machining allowance is maintained at 0.5 mm; The feed per pass for semi-finish machining the side wall is 1 mm, the spindle speed for semi-finish machining the side wall is 800 r / min, the feed rate for semi-finish machining the side wall is 1.3 m / min, the unilateral machining allowance is maintained at 0.5 mm, and the surface roughness is 3.2 μm.

[0062] (8) Finish machining the grid rudder connection seat part: The feed per pass for finish machining the plane is 0.2 mm, the spindle speed for finish machining the plane is 1000 r / min, and the feed rate for finish machining the plane is 1.5 m / min; The feed per pass for finish machining the side is 1 mm, the spindle speed for finish machining the side is 1000 r / min, and the feed rate for finish machining the side is 1.5 m / min. Select a small tool to trim the plane of the innermost outer frame of the grid rudder, and then select a large tool to finish trim the plane of the grid rudder outer frame. The feed per pass for small tool finish trimming is 0.2 mm, the feed per pass for large tool finish trimming is 0.3 mm, the spindle speeds for finish trimming are both 800 r / min, and the feed rates for finish trimming are both 1.3 m / min.

[0063] (9)Hole machining for the grid rudder connecting seat: The spindle speed for drilling is 500 r / min, and the feed rate for drilling is 1.5 m / min; reaming is carried out by milling. The feed per pass for reaming is 0.2 mm, the spindle speed for reaming is 500 r / min, and the feed rate for reaming is 1 m / min; the feed per pass for boring is 0.05 mm, the spindle speed for boring is 800 r / min, and the feed rate for boring is 1 m / min. Tap the threaded hole.

[0064] Surface finishing: Grind and polish the surface of the machined grid rudder, and the final part is obtained after passing the inspection.

[0065] After being machined by this method, the dimensional accuracy, geometric tolerance, and surface finish of the grid rudder are significantly improved. The dimensional accuracy and geometric tolerance are both controlled within 0.1 mm, the surface roughness is improved from Ra6.3 to above Ra3.2, and the product qualification rate is increased from the original 40% to 100%.

[0066] Matters not covered by this invention are well-known technologies.

[0067] The above embodiments are only used to illustrate the technical concept and features of the present invention. The purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and it should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A manufacturing method of a grid fin, characterized in that It includes the following steps: (1) Rough machine the part blank: First, rough machine the outer frame structure of the part, and then rough machine the internal grid structure. The rough machining of the grid structure is as follows: first mill round holes, and then expand and mill the inner shape; (2) Perform stress relief annealing on the part; (3) Semi-finish machine the part: First, semi-finish mill the outer frame structure, and then semi-finish mill the internal grid structure; (4) Finish machine the part: First, finish mill the outer frame structure of the part, and then finish mill the internal grid structure; (5) Finish grind the reference surface of the part; (6) Finish mill the sunken mounting surface of the part; (7) Semi-finish machine the connecting seat structure of the part: first semi-finish machine the plane, and then machine the side surface; (8) Finish machine the connecting seat structure of the part: first finish machine the plane, and then machine the side surface; (9) Machine holes in the connecting seat structure of the part: first punch the center point, then drill, ream, and finally bore the hole.

2. The manufacturing method of the grid rudder according to claim 1, wherein: In step (1), before rough machining, the forging blank shall be subjected to 100% ultrasonic flaw detection according to GJB2218-1994. Subsequently, for the mechanical property requirements of the titanium plate after forging, the ultimate strength in the main direction and rolling direction shall not be less than 895 MPa, the yield limit shall not be less than 825 MPa, and the elongation shall not be less than 10%. Then, the forging shall be subjected to 100% penetrant inspection according to GJB2367A-2005.

3. The manufacturing method of the grid rudder according to claim 1, characterized in that: In step (1), rough machining is carried out in two steps: The first step: For rough machining of the outer frame, the feed per pass is 4-6 mm, the spindle speed for rough machining of the outer frame is 500-800 r / min, the feed rate for rough machining of the outer frame is 1-1.5 m / min, the unilateral machining allowance is kept at 3-5 mm, and the surface roughness is 6.3-12.5 μm; for rough machining of the grid, the feed per pass is 0.5-1 mm, the spindle speed for rough machining of the grid is 600-800 r / min, the feed rate for rough machining of the grid is 1-1.3 m / min, the unilateral machining allowance is kept at 3-5 mm, and the surface roughness is 6.3-12.5 μm; adopt the method of milling holes first and then milling the shape. First, machine the round holes of the innermost triangular grid, then machine the round holes of the outermost triangular grid, and the round holes of the triangular grids on the left and right sides respectively. Subsequently, machine the round holes of the quadrilateral grid in three times from the outside to the inside; The second step: For rough machining of the outer side of the outer frame, the feed per pass is 2-4 mm, the spindle speed for rough machining of the outer side of the outer frame is 500-800 r / min, the feed rate for rough machining of the outer side of the outer frame is 1-1.5 m / min, the unilateral machining allowance is kept at 1.5-3 mm, and the surface roughness is 6.3-12.5 μm; for rough machining of the grid, the feed per pass is 0.05-0.1 mm, the spindle speed for rough machining of the grid is 600-800 r / min, the feed rate for rough machining of the grid is 1.3-1.7 m / min, the unilateral machining allowance is kept at 1.5-3 mm, and the surface roughness is 6.3-12.5 μm. When rough machining the grid, machine the grid shape in three times from the outside to the inside in sequence for the blank, and process the connections between the inside and outside of the grid into rounded corners to ensure smooth transition between regions.

4. The manufacturing method of the grid rudder according to claim 1, characterized in that: In step (2), the stress relief annealing treatment is specifically as follows: steadily heat up at a rate of 150 °C / h, heat up in the furnace to 600 - 700 °C, and keep the temperature for 4 - 8 h.

5. The manufacturing method of the grid rudder according to claim 1, characterized in that: In step (3), semi-finishing is carried out in two steps: The first step: The feed per pass for semi-finishing the outer frame is 3 - 5 mm, the spindle speed for semi-finishing the outer frame is 500 - 800 r / min, the feed rate for semi-finishing the outer frame is 1 - 1.3 m / min, and the surface roughness is 3.2 - 6.3 μm; the feed per pass for semi-finishing the inner wall of the grid is 0.5 - 1 mm, the spindle speed for semi-finishing the inner wall of the grid is 500 - 800 r / min, the feed rate for semi-finishing the inner wall of the grid is 1.3 - 1.5 m / min, and the surface roughness is 3.2 - 6.3 μm. The unilateral machining allowance is kept at 1.5 - 3 mm, and the machining depth is half of the part thickness. The semi-finishing sequence is to first machine the inner wall of the outermost triangular grid, then machine the inner walls of the triangular grids on the left and right sides, then machine the outermost row of quadrilateral grids, and successively machine inwards. The innermost quadrilateral grid is machined symmetrically, and finally the innermost triangular grid is machined symmetrically. The second step: The feed per pass for semi-finishing the inner wall of the grid is 0.3 - 0.5 mm, the spindle speed is 500 - 800 r / min, the feed rate is 1.3 - 1.5 m / min, and the surface roughness is 3.2 - 6.3 μm. The unilateral machining allowance is kept at 1.5 - 3 mm, and the machining depth is the part thickness. The machining sequence is to first machine the inner wall of the outermost triangular grid, then successively machine two rows of inner quadrilateral grid walls inwards, then machine the inner walls of the triangular grids on the left and right sides, then successively machine the inner quadrilateral grid walls in rows inwards. The innermost quadrilateral grid is machined symmetrically, then the inner wall of the innermost triangular grid is machined symmetrically, and finally all the inner walls of the triangular grids are chamfered in the order from outside to inside.

6. The manufacturing method of the grid rudder according to claim 1, characterized in that: Before step (4) and after step (3), the part is annealed at a holding temperature of 600 - 700 °C for 4 - 8 h.

7. The manufacturing method of the grid rudder according to claim 1, characterized in that: In step (4), the finishing method is as follows: The outer frame is finished by three passes of feed. The unilateral machining allowance per pass is 2 mm, 0.35 mm, and 0.1 mm respectively. The spindle speed for finishing the outer frame is 500 - 800 r / min, the finishing feed rate is 1 - 1.3 m / min, the surface roughness is 3.2 - 6.3 μm, and the cutting depth is half of the total thickness of the grid rudder; the feed per pass for finishing the inner wall of the grid is 1 - 2 mm, the spindle speed is 500 - 800 r / min, the feed rate is 1 - 1.3 m / min, the surface roughness is 1.6 - 3.2 μm, the unilateral machining allowance is kept at 0.75 - 1.25 mm, and the cutting depth is half of the total thickness of the grid rudder. The machining sequence is to first machine the inner wall of the outermost triangular grid rudder, then machine two rows of inner quadrilateral grid walls inwards, then machine the inner walls of the triangular grids on the left and right sides, then successively machine the inner quadrilateral grid walls in rows inwards. The innermost quadrilateral grid wall is machined symmetrically, and finally the inner wall of the innermost triangular grid is machined. Use a small cutter to finish machining the flat surface of the grid rudder outer frame. The feed per pass for finishing the outer frame flat surface is 0.5 - 1 mm, the spindle speed for finishing the outer frame flat surface is 500 - 800 r / min, the feed rate is 1 - 1.3 m / min, and the surface roughness is 1.6 - 3.2 μm. Use a small cutter to finish machining the flat surface of the grid inner wall. The parameters for finishing the grid inner wall flat surface are the same as those for finishing the outer frame flat surface, and the machining is carried out in three times from the outside to the inside in sequence. Turn it over and machine the other side using the above finishing method.

8. The manufacturing method of the grid rudder according to claim 1, characterized in that: In step (7), first use a large cutter to semi-finish the plane depression, and then select a small cutter to semi-finish the side wall. The feed per pass for semi-finishing the plane depression is 0.5 - 1 mm, the spindle speed is 800 - 1000 r / min, the feed rate is 1.3 - 1.5 m / min, and the unilateral machining allowance is kept at 0.3 - 1 mm. The feed per pass for semi-finishing the side wall is 1 - 2 mm, the spindle speed is 800 - 1000 r / min, the feed rate is 1.3 - 1.5 m / min, and the unilateral machining allowance is kept at 0.5 - 1 mm, and the surface roughness is 1.6 - 3.2 μm.

9. The manufacturing method of the grid rudder according to claim 1, characterized in that: In step (8), machine the plane first and then the side. It is completed in two times using the machining method of first using a large cutter and then a small cutter. The feed per pass for finishing the plane is 0.2 - 0.5 mm, the spindle speed is 800 - 1000 r / min, and the feed rate is 1.3 - 1.5 m / min. The feed per pass for finishing the side is 1 - 2 mm, the spindle speed is 800 - 1000 r / min, and the feed rate is 1.3 - 1.5 m / min. Select a small cutter to trim the innermost outer frame flat surface of the grid rudder, and then select a large cutter to finish trimming the grid rudder outer frame flat surface. The feed per pass for small cutter finishing trimming is 0.1 - 0.3 mm, the feed per pass for large cutter finishing trimming is 0.3 - 0.5 mm, the spindle speed for both finishing trimmings is 500 - 800 r / min, and the feed rate for both finishing trimmings is 1 - 1.3 m / min.

10. The manufacturing method of the grid rudder according to claim 1, characterized in that: In step (9), for the machining of the positioning hole, first mark the point, then drill, ream, and finally bore the hole. For the machining of the threaded hole, first mark the point, then drill and ream the hole. The spindle speed for drilling is 500 - 800 r / min, and the feed rate is 1.3 - 1.5 m / min. Reaming is carried out by milling. The feed per pass for reaming is 0.1 - 0.3 mm, the spindle speed is 500 - 800 r / min, and the feed rate is 1 - 1.3 m / min. The feed per pass for boring is 0.05 - 0.1 mm, the spindle speed is 800 - 1000 r / min, and the feed rate is 1 - 1.3 m / min.

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