Split type boring cutter and manufacturing method thereof

Abstract

The invention belongs to the technical field of aeronautical manufacturing, and discloses a split type boring cutter and a manufacturing method thereof.A cutter bar and a cutter head of a boring cutter are ingeniously designed and matched in tolerance, the cutter head is designed to be of a double-edge welding type structure with a positioning convex shoulder, and a square hole and a positioning face matched with the cutter head are cut in the cutter bar through linear cutting; and a jackscrew which is fed and inclined in the axial direction is arranged for jacking the cutter head, the cutter head is prevented from moving back and forth in the axial direction and the radial direction, the blade and the cutter body are welded through high-frequency welding and ground to the boring cutter dividing size, the cutter positioning precision can reach 0.005 mm, the outer circle precision can reach 0.005 mm, and the H7-level tolerance requirement of an intersection point hole is met. When the multi-step cutter-dividing boring cutter is replaced, the cutter and a tool do not need to be disassembled, the size of the cutter does not need to be adjusted, only the cutter head needs to be replaced, and the cutter cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of tool processing in aviation manufacturing, and specifically relates to a split-type boring tool for intersection holes used for docking large aircraft components and a manufacturing method thereof. Background Art

[0002] When large aircraft parts are docked, intersection holes need to be processed. The hole-making position is very critical. The intersection hole processing conditions often have the following characteristics: high material hardness, large hole size, usually H7 precision, and small hole-making space. Its high-precision and high-efficiency hole-making tools have long been the main technical difficulties affecting product quality. When processing intersection holes for aircraft docking, most hole-making equipment cannot be used due to limited space. At present, most automatic feed drills are used for multi-step boring when space permits. In professional books, there are many structural forms of boring tools. However, considering the hole-making working conditions, the tool structure and cutting parameters used, there are currently only two boring tool structures suitable for this working condition: the integral welded blade type and the machined blade type. The integral welded blade type has the characteristics of simple structure, short manufacturing time and high machining accuracy. However, after one hole is made, the boring tool needs to be disassembled and installed as a whole. Due to the complex working conditions on the hole-making site, it is often necessary to remove the automatic feed drill, guide sleeve, nose tube and other components before the tool can be removed, which takes 12-15 minutes. At the same time, when the boring tool is worn and chipped, the integral structure can only be scrapped. The machined blade type has the characteristics of convenient tool change and cheap blade price. However, the machine-clamped blade type boring tool has a complex structure, a long manufacturing time, and low blade repeatability, making it difficult to meet H7 and aperture tolerances. Therefore, workers are still required to disassemble and install the tool before each hole is made to complete the tool size adjustment. Once the size adjustment is improper, there will be a serious quality risk of out-of-tolerance hole making at the intersection.

[0003] In order to eliminate the above risks, a boring tool structure is needed, in which the tool head can be easily disassembled, no size adjustment is required, and high-precision positioning is required, so as to improve tool changing efficiency, reduce production costs, and ensure product processing accuracy. Summary of the invention

[0004] The present invention application proposes a split boring tool and a manufacturing method thereof, wherein the tool head can be easily disassembled and does not require size adjustment for processing intersection holes for docking large aircraft components. The tool has a simple structure and high repeatability positioning accuracy, and solves the current problems of long tool change time, high production cost, and inability to guarantee product aperture tolerance and coaxiality in intersection hole processing.

[0005] In order to achieve the above invention objectives, the technical solutions adopted in this application are as follows:

[0006] A split boring tool adopts a split structural design, which includes:

[0007] A tool bar, which is provided with a square hole and a top screw hole, wherein the top screw hole is arranged obliquely along the tool feed direction;

[0008] The cutter head is provided with a top screw groove matched with the top screw hole. The cutter head passes through the square hole and is screwed into the top screw groove for tightening.

[0009] As a further solution of the present invention: the tool rod is further provided with a positioning surface, the tool head is further provided with a positioning boss, and the tool rod and the tool head are assembled and fit each other.

[0010] As a further solution of the present invention: the top screw hole of the tool rod is inclined along the tool feed direction to form an angle, the top screw groove of the cutter head has the same axial angle as the top screw hole of the tool rod, the top screw is screwed into the top screw groove to tighten the cutter head to prevent the cutter head from moving when making a hole.

[0011] As a further solution of the present invention: the U-shaped keyway, rear guide and front guide of the tool rod have coaxiality requirements, and the outer circle tolerance of the tool rod is g6; the positioning surface is lower than the outer circle of the tool rod, and the length tolerance and width tolerance of the square hole are H8; the two top screw holes are symmetrically distributed on the center line of the tool rod, and the angle between the axial direction and the center line is 75°.

[0012] As a further solution of the present invention: the blade and the blade body in the cutter head are welded by high frequency, the length tolerance and width tolerance of the blade body are f7, the matching relationship with the square hole of the tool rod is a small clearance match, the outer circle of the blade body is provided with an inverted cone, and the blade is made of cemented carbide.

[0013] As a further solution of the present invention: when the tool is in use, the U-shaped keyway of the tool rod is connected to the automatic feed drill spindle, the rear guide passes through the guide sleeve, and the front guide passes through the drill template, and the matching tolerance is H7 / g6.

[0014] A method for manufacturing a split boring tool comprises the following steps:

[0015] Machining tool heads;

[0016] Machined toolholders;

[0017] The cutter head and the cutter bar are assembled as a set and then machined.

[0018] As a further solution of the present invention: the tool head processing comprises the following steps:

[0019] 1) Cut the bar stock and turn both ends flat;

[0020] 2) The width of the milling cutter body is ground on both ends (0.2-0.3) mm;

[0021] 3) Mark the top screw groove positioning line;

[0022] 4) Milling the top screw groove of AA section;

[0023] 5) Align with the center line of the top screw groove, cut the main view shape by wire cutting, and process the outer diameter to (D-1.5) mm;

[0024] 6) The milling cutter body has a 5° back angle, the milling insert slot, and the outer circle is enlarged by (0.6-0.7) mm;

[0025] 7) Quenching HRC40-45, sand blasting;

[0026] 8) Blade welding is performed by high-frequency welding, with the outer circle ground to (0.6-0.7) mm, and the blade end extends 0.5 mm out of the blade body;

[0027] 9) Sand blasting at the welding point, the overall blade head turns blue;

[0028] 10) Grinding the rough back angle;

[0029] 11) Grind the two ends of the cutter body to the required width;

[0030] 12) Grind the spline ends of the cutter body to the required length, and grind the positioning shoulder Ra0.4 surface to the required length; align with the center line of the top screw groove, cut out the cutter body shape by wire cutting, and process the outer diameter of the tool to (D-1.5) mm.

[0031] As a further solution of the present invention: the tool bar processing comprises the following steps:

[0032] 1) Turn the flat end surface, drill the center hole, turn into shape, grind each outer circle to (0.7-0.8) mm, and chamfer;

[0033] 2) Mark the U-shaped keyway and threading hole line of the cutter bar, and drill the threading hole (Φ4mm);

[0034] 3) Mill the U-shaped keyway to the requirements;

[0035] 4) Quenching and tempering to HRC40-45, sand blasting and bluing;

[0036] 5) Roughly grind the outer circle of the tool bar and leave 0.4~0.5;

[0037] 6) Stress relief tempering;

[0038] 7) The outer circle of the grinding rod is left to grind 0.1~0.2;

[0039] 8) Use V-shaped iron to align the outer circle of the cutter bar, cut the wire slowly, and match the cutter head to cut square holes, empty cutters and positioning surfaces to the requirements;

[0040] 9) Mark the cutter head and locate the top screw hole;

[0041] 10) Symmetrical boring of top screw bottom holes and countersunk holes;

[0042] 11) Tap the thread holes to the required level;

[0043] 12) Grind the outer diameter of the tool rod to the required size.

[0044] As a further solution of the present invention, the processing after the cutter head and the cutter bar are assembled into a set includes the following steps:

[0045] 1) Collect all parts, assemble into a set, and grind the front angle of 5° to the required value;

[0046] 2) Roughly grind the outer diameter of the cutter head;

[0047] 3) CNC grinding of outer circle and back taper of blade to requirements;

[0048] 4) Grind the blade end face flush and cut at a 45° cutting angle;

[0049] 5) Grind the blade to a 45° cutting angle and a 10° back angle to the required value.

[0050] Compared with the prior art, the beneficial effects of this application are:

[0051] 1. This application ingeniously designs and coordinates the tolerances of the boring tool arbor and the cutter head, designs the cutter head into a double-edged welded structure with a positioning shoulder, uses wire cutting to cut out a square hole and a positioning surface that matches the cutter head in the arbor, and sets a top screw that is inclined along the axial feed to tighten the cutter head to prevent the cutter head from moving back and forth in the axial and radial directions. The blade and the cutter body are welded by high-frequency welding and ground to the boring tool size. The tool positioning accuracy can reach 0.005mm, and the outer circle accuracy can reach 0.005mm, which meets the H7 tolerance requirement of the intersection hole.

[0052] 2. When changing tools during multi-step boring, there is no need to remove the tools and tools, and there is no need to adjust the tool size. You only need to unscrew the top screw to replace the tool head. When installing the boring tool head in the next step, you only need to fit the positioning boss of the tool head tightly with the positioning surface of the tool rod, and then tighten the top screw. Tool changing is very convenient, and the efficiency is improved by 10 times. When the tool is chipped and worn, you only need to replace the tool head to reduce the tool cost.

[0053] The present application is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0055] In the attached picture:

[0056] Figure 1 It is a schematic diagram of the overall structure of the split boring tool of the present invention;

[0057] Figure 2 It is a schematic diagram of the structure of the split boring tool arbor of the present invention;

[0058] Figure 3 It is a schematic diagram of the structure of the split boring tool head of the present invention;

[0059] Figure 4 It is a schematic diagram of the application of the split boring tool of the present invention.

[0060] In the figure: 1. tool bar; 2. tool head; 3. top screw; 4. automatic feed drill spindle; 5. guide sleeve; 6. drilling template; 1-1. U-shaped keyway; 1-2. rear guide; 1-3. square hole; 1-4. positioning surface; 1-5. top screw hole; 1-6. front guide; 2-1. blade; 2-2. tool body; 2-3. positioning boss; 2-4. top screw groove; D, tool diameter; d, tool bar diameter; L1, square hole length; L2, square hole width; l1, tool body length; l2, tool body width. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0062] First, see Figure 1-4 The present invention discloses a split boring tool for the intersection holes of large aircraft parts, which comprises a tool bar 1, a tool head 2 and a top screw 3. The tool head 2 passes through a square hole 1-3 of the tool bar 1, a positioning boss 2-3 of the tool head 2 fits with a positioning surface 1-4 of the tool bar 1, a top screw hole 1-6 of the tool bar 1 is inclined along the tool feeding direction to form an angle, a top screw groove 2-4 of the tool head 2 has the same axial angle as that of the top screw hole 1-6, and the top screw 3 is screwed into the top screw groove 2-4 to tighten the tool head 2 to prevent the tool head 2 from moving when making a hole.

[0063] Furthermore, the U-shaped keyway 1-1, rear guide 1-2 and front guide 1-6 of the tool rod 1 have coaxiality requirements, and the outer circle tolerance of the tool rod 1 is g6; the positioning surface 1-4 is lower than the outer circle of the tool rod 1, and the length L1 tolerance and width L2 tolerance of the square hole 1-3 are H8; the two top screw holes 1-5 are symmetrically distributed on the center line of the tool rod 1, and the angle between the axial direction and the center line is 75°.

[0064] Furthermore, the blade 2-1 and the blade body 2-2 in the cutter head 2 are high frequency welded, the blade body length l1 tolerance and width l2 tolerance are f7, the matching relationship with the square hole 1-3 of the shank 1 is a small clearance match, and the outer circle of the blade body 2-2 is provided with an inverted cone. The blade 2-1 is made of cemented carbide.

[0065] Furthermore, when the tool is in use, the U-shaped keyway 1-1 of the tool bar 1 is connected to the automatic feed drill spindle 4, the rear guide 1-2 passes through the guide sleeve 5, and the front guide 1-6 passes through the drilling template 6, and the matching tolerance is H7 / g6.

[0066] This embodiment also discloses a split boring tool of specific size, which includes a tool bar 1, a tool head 2 and a top screw 3. The tool bar includes a U-shaped keyway 1-1, a rear guide 1-2, a square hole 1-3, a positioning surface 1-4, a top screw hole 1-5, and a front guide 1-6. The tool head includes a blade 2-1, a tool body 2-2, a positioning shoulder 2-3, and a top screw groove 2-4. When the tool is installed, the tool body 2-2 of the tool head 2 and the square hole 1-3 of the tool bar 1 are matched with a small gap. The tool head 2 is inserted into the square hole 1-3, the positioning shoulder 2-3 is tightly fitted with the positioning surface 1-4, and the top screw 3 is screwed into the top screw groove 2-4 to tighten the tool body 2-2 to prevent the tool head 2 from moving when making a hole. When the tool is in use, the U-shaped keyway 1-1 of the tool bar 1 is connected to the automatic feed drill spindle 4, the rear guide 1-2 passes through the guide sleeve 5, and the front guide 1-6 passes through the drilling template 6, and the matching tolerance is H7 / g6.

[0067] Furthermore, the tool rod 1 is made of No. 45 steel, the coaxiality requirement of the U-shaped keyway 1-1, the rear guide 1-2, and the front guide 1-6 is 0.01mm, and the outer circle tolerance of the tool rod 1 is g6; the positioning surface 1-4 is arranged parallel to one side of the center line of the tool rod 1, 1.5mm lower than the outer circle of the tool rod 1; the square hole 1-3 is perpendicular to the positioning surface 1-4, and its center point passes through the center line of the tool rod 1. The length L1 tolerance and width L2 tolerance of the square hole 1-3 are H8; the two top screw holes 1-5 are symmetrically distributed on the center line of the tool rod 1, and the angle between the axial direction and the center line is 75°.

[0068] Furthermore, the blade 2-1 and the blade body 2-2 in the cutter head 2 are welded by high frequency. The blade body 2-2 is made of 45# steel, with a length l1 tolerance and a width l2 tolerance of f7. The matching relationship with the square hole 1-3 of the arbor is H8 / f7. The outer circle of the blade body 1 is inverted taper 5°, the length of the positioning boss 2-3 is 5mm, and the axial angle of the top screw groove 2-4 is the same as that of the top screw hole 1-5 of the arbor. The blade 2-1 is made of cemented carbide, with a cutting angle of 45°, a front angle of 5°, a back angle of 10°, and an inverted taper of 3°.

[0069] In the second aspect, the present invention discloses a method for manufacturing a split boring tool for a large aircraft component joint intersection hole, wherein the tool head processing includes steps 1-1 to 1-12, the tool bar processing includes steps 2-1 to 2-12, and the processing after the tool head and the tool bar are assembled into a set includes steps 3-1 to 3-5, which are specifically as follows:

[0070] The steps for cutting head processing are as follows:

[0071] Step 1-1: Place the bar stock and flatten both ends;

[0072] Step 1-2: Grind the width of both ends of the milling cutter body to (0.2-0.3) mm;

[0073] Step 1-3: Draw the top screw groove positioning line;

[0074] Step 1-4: Mill the top screw groove of the AA section;

[0075] Step 1-5: Align with the center line of the top screw groove, cut out the shape of the cutter body by wire cutting, and process the outer diameter of the cutter to (D-1.5) mm;

[0076] Step 1-6: 5° back angle of the milling cutter body, milling insert slot, and enlarge the outer circle by (0.6-0.7) mm;

[0077] Step 1-7: Quenching HRC40-45, sand blasting;

[0078] Step 1-8: Weld the blade with high frequency welding, grind the outer circle to (0.6-0.7) mm, and extend the blade end out of the blade body by 0.5 mm;

[0079] Step 1-9: Sandblast the welding area and make the blade blue;

[0080] Step 1-10: Grind the rough back angle;

[0081] Step 1-11: Grind the two end surfaces of the cutter body to the required width;

[0082] Step 1-12: Grind the spline end surfaces of the cutter body to the required length, and grind the positioning shoulder Ra0.4 surface to the required length.

[0083] The tool bar processing steps are as follows:

[0084] Step 2-1: Turn the flat end surface, drill the center hole, turn into shape, grind each outer circle to (0.7-0.8) mm, and chamfer;

[0085] Step 2-2: Draw the U-shaped keyway and threading hole line on the cutter bar, and drill the threading hole (Φ4mm)

[0086] Step 2-3: Mill the U-shaped keyway to the required size;

[0087] Step 2-4: quenching and tempering to HRC40-45, sand blasting and bluing;

[0088] Step 2-5: Roughly grind the outer circle of the tool bar to leave 0.4 to 0.5;

[0089] Step 2-6: Stress relief and tempering;

[0090] Step 2-7: Grind the outer circle of the tool rod by 0.1 to 0.2;

[0091] Step 2-8: Use V-shaped iron to align the outer circle of the cutter bar, use wire cutting to cut the square holes, empty cutters and positioning surfaces to the required size with the cutter head;

[0092] Step 2-9: Mark the cutter head and locate the top screw hole;

[0093] Step 2-10: Symmetrically bore the top screw bottom hole and countersunk hole;

[0094] Step 2-11: Tap the thread holes to the required thread;

[0095] Step 2-12: Grind the outer diameters of the tool rods to the required size.

[0096] The processing steps after the cutter head and the cutter bar are assembled into a set are as follows:

[0097] Step 3-1: Collect all parts, assemble into a set, and grind the front angle of 5° to the required value;

[0098] Step 3-2: Roughly grind the outer diameter of the cutter head;

[0099] Step 3-3: CNC grinding of the outer circle of the blade and the back taper to the requirements;

[0100] Step 3-4: Grind the end surface of the blade to make it flush and the cutting angle to 45°;

[0101] Step 3-5: Grind the 45° cutting angle and 10° back angle to the requirements.

[0102] So far, the purpose of the present invention has been achieved.

[0103] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A split boring tool, characterized in that: Adopt split structure design, including: A tool bar, which is provided with a square hole and a top screw hole, wherein the top screw hole is arranged obliquely along the tool feed direction; The cutter head is provided with a top screw groove matched with the top screw hole. The cutter head passes through the square hole and is screwed into the top screw groove for tightening.

2. A split boring tool according to claim 1, characterized in that: The knife rod is also provided with a positioning surface, and the knife head is also provided with a positioning boss. The knife rod and the knife head are assembled and fit each other.

3. A split boring tool according to claim 2, characterized in that: The top screw hole of the tool rod is inclined along the tool feeding direction to form an angle. The axial angle of the top screw groove of the tool head is the same as that of the top screw hole of the tool rod. The top screw is screwed into the top screw groove to tighten the tool head to prevent the tool head from moving when making holes.

4. A split boring tool according to claim 3, characterized in that: The U-shaped keyway, rear guide and front guide of the tool rod have coaxiality requirements, and the outer circle tolerance of the tool rod is g6; the positioning surface is lower than the outer circle of the tool rod, and the length tolerance and width tolerance of the square hole are H8; the two top screw holes are symmetrically distributed on the center line of the tool rod, and the angle between the axial direction and the center line is 75°.

5. A split boring tool according to claim 4, characterized in that: The blade and the cutter body in the cutter head are welded by high frequency. The length tolerance and width tolerance of the cutter body are f7, and the matching relationship with the square hole of the cutter rod is a small clearance match. The outer circle of the cutter body is provided with an inverted cone, and the blade is made of cemented carbide.

6. A split boring tool according to claim 5, characterized in that: When the tool is in use, the U-shaped keyway of the tool bar is connected to the automatic feed drill spindle, the rear guide passes through the guide sleeve, and the front guide passes through the drill template, and the matching tolerance is H7 / g6.

7. A method for manufacturing a split boring tool, characterized in that: The steps include: Machining tool heads; Machined toolholders; The cutter head and the cutter bar are assembled as a set and then machined.

8. A split boring tool according to claim 7, characterized in that: The tool head processing comprises the following steps: 1) Cut the bar stock and turn both ends flat; 2) The width of the milling cutter body is ground on both ends (0.2-0.3) mm; 3) Mark the top screw groove positioning line; 4) Milling the top screw groove of AA section; 5) Align with the center line of the top screw groove, cut the main view shape by wire cutting, and process the outer diameter to (D-1.5) mm; 6) The milling cutter body has a 5° back angle, the milling insert slot, and the outer circle is enlarged by (0.6-0.7) mm; 7) Quenching HRC40-45, sand blasting; 8) Blade welding is performed by high-frequency welding, with the outer circle ground to (0.6-0.7) mm, and the blade end extends 0.5 mm out of the blade body; 9) Sand blasting at the welding point, the overall blade head turns blue; 10) Grinding the rough back angle; 11) Grind the two ends of the cutter body to the required width; 12) Grind the spline ends of the cutter body to the required length, and grind the positioning shoulder Ra0.4 surface to the required length; align with the center line of the top screw groove, cut out the cutter body shape by wire cutting, and process the outer diameter of the tool to (D-1.5) mm.

9. A split boring tool according to claim 7, characterized in that: The tool bar processing comprises the following steps: 1) Turn the flat end surface, drill the center hole, turn into shape, grind each outer circle to (0.7-0.8) mm, and chamfer; 2) Mark the U-shaped keyway and threading hole line of the cutter bar, and drill the threading hole (Φ4mm); 3) Mill the U-shaped keyway to the requirements; 4) Quenching and tempering to HRC40-45, sand blasting and bluing; 5) Roughly grind the outer circle of the tool bar and leave 0.4~0.5; 6) Stress relief tempering; 7) The outer circle of the grinding rod is left to grind 0.1~0.2; 8) Use V-shaped iron to align the outer circle of the cutter bar, cut the wire slowly, and match the cutter head to cut square holes, empty cutters and positioning surfaces to the requirements; 9) Mark the cutter head and locate the top screw hole; 10) Symmetrical boring of top screw bottom holes and countersunk holes; 11) Tap the thread holes to the required level; 12) Grind the outer diameter of the tool rod to the required size.

10. The split boring tool according to claim 7, characterized in that: The processing after the cutter head and the cutter bar are assembled into a set includes the following steps: 1) Collect all parts, assemble into a set, and grind the front angle of 5° to the required value; 2) Roughly grind the outer diameter of the cutter head; 3) CNC grinding of outer circle and back taper of blade to requirements; 4) Grind the blade end face flush and cut at a 45° cutting angle; 5) Grind the blade to a 45° cutting angle and a 10° back angle to the required value.

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