A wing positioning blind hole drilling tool and a processing method

Abstract

The present application belongs to the field of aircraft assembly tooling, and relates to a wing positioning blind hole drilling tool and a processing method. The tool comprises a cutting part, a neck, a guide structure and a handle, the cutting part comprises an end tooth and a circumferential tooth connected by a circular arc blade, a micro-angle blade strip is arranged at the cutting edge of the circumferential tooth, the end tooth is wedge-shaped, the circumferential tooth is arc-shaped, and according to the number and angle of the teeth, the tool is divided into a rough machining tool and a fine machining tool, and a ventilation groove is arranged on the outer wall of the guide structure; during drilling, rough machining is performed first, and then fine machining is performed, and during the drilling process, air is sent in the radial and axial directions at the hole opening and the rear part of the guide structure respectively to assist in chip removal. By arranging the micro-angle blade strip, the contact area between the cutting edge and the hole wall is reduced, and the cutting resistance is reduced; by sending air to the hole opening during processing, the chips are quickly discharged under the action of the wind, the chip winding phenomenon is avoided, the cutting resistance is further reduced, and the tool is prevented from being stuck.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aircraft assembly tooling, in particular to a positioning blind hole drilling tool for wing joining and a processing method. BACKGROUND

[0002] Wing joining is an important part of the aircraft assembly process. Due to the huge size of the aircraft, the fuselage and the wing cannot be integrally formed and manufactured, but can only be processed separately and then assembled into a whole. Before joining and assembling, a positioning blind hole needs to be processed on the fuselage and the wing respectively, and the relative position of the fuselage and the wing is determined through the blind hole, and then the subsequent assembly processing is completed. Therefore, the processing precision and quality of the positioning blind hole will directly affect the assembly precision and efficiency of the subsequent wing joining.

[0003] The processing of the positioning blind hole is a key step in the fine processing of the wing joining assembly. In the past, workers used hand-held pneumatic tools for manual processing, which was low in efficiency and poor in quality, and the consistency of hole making could not be guaranteed. With the popularization of automatic and digital equipment in the domestic aircraft manufacturing industry, numerical control equipment is gradually used to replace manual processing in the fine processing of wing joining assembly, and the hole making precision and efficiency of the positioning blind hole have been significantly improved. However, in the process of automatic hole making, the control of chips and cutting resistance is crucial. The diameter and depth of the positioning blind hole are relatively large, and the cutting allowance is particularly large, which will generate a large amount of chips during processing. In the past manual processing, workers could clean the chips at any time to avoid the occurrence of chip entanglement and chip jamming. However, if automatic hole making equipment is used, it will be difficult to clean the chips, and if the machine is stopped for cleaning, the quality and efficiency of automatic hole making will be greatly reduced. On the other hand, automatic equipment often monitors the cutting resistance during tool hole making to determine whether the tool is working normally. Once chip entanglement or chip jamming occurs, the cutting resistance will suddenly increase, and if it exceeds the warning value of the hole making equipment, it may cause the equipment to stop suddenly, causing damage to the equipment, tool and wing parts. In the process of aircraft assembly, the space is limited, and the use of automatic equipment makes the available space even smaller. Therefore, the distance between the guide tooling and the wing part is very close, which further increases the difficulty of chip removal. Chips may also enter the gap between the guide bushing and the tool, causing the tool to be stuck, resulting in equipment downtime and affecting hole making quality and efficiency. SUMMARY

[0004] The technical problem to be solved by the present application is that the cutting resistance of the blind hole drilling tool is large, and the chips generated during automatic hole making are difficult to remove, which further increases the cutting resistance. To solve the above technical problems, the present application provides a positioning blind hole drilling tool for wing joining and a processing method.

[0005] The technical solution adopted by the present application is as follows:

[0006] The present application relates to a kind of wing folding positioning blind hole drilling cutter, the drilling cutter includes cutting portion 1, neck 2, guide structure 3 and tool holder 4, cutting portion 1 is connected with neck 2, the other end of neck 2 is provided with guide structure 3, the other end of guide structure 3 is connected tool holder 4, the cutting portion 1 includes the two parts of end tooth 11 being arranged in end surface and circumferential tooth 12 being arranged on the circumferential surface of cutting portion 1, circumferential tooth 12 is connected with end tooth 11 by circular arc blade, micro-angle blade zone 5 is arranged in extension at the tip of circumferential tooth 12, reduce the contact area of tip and hole wall, circumferential tooth 12 can be arranged into helical structure along the axial direction, improve the chip removal capacity of tool.

[0007] The outer wall of the guide structure 3 is provided with ventilation groove 6, the cross section is scallop, rectangle or other shape, the edge line formed at the intersection of ventilation groove 6 and the outer wall of guide structure 3 remains sharp.

[0008] Further, the ventilation groove 6 is circular-arc-shaped groove arranged along the axial direction, and the depth of the circular arc is equal to 3 / 4 of the radius of the circular arc.

[0009] Further, the micro-angle blade zone 5 is a micro-rake angle 51 arranged in extension from the tip to the relief, and the angle is 1°±30', and the width 52 of the micro-angle blade zone 5 is 0.8-0.9mm.

[0010] Further, the end tooth 11 is wedge-shaped, has an end tooth rake angle and an end tooth relief angle, wherein the end tooth rake angle extends from the tip of the end tooth 11 to the rake surface, and the end tooth relief angle extends from the tip of the end tooth 11 to the relief surface, for reducing the friction between the relief surface and the bottom surface of the blind hole, and the end tooth relief angle is a single angle or a plurality of angles arranged in sequence according to a broken line; the circumferential tooth 12 is arc-shaped, has the same number of end teeth 11, has a circumferential tooth rake angle 121 and a circumferential tooth relief angle 122, wherein the circumferential tooth rake angle 121 extends from the tip of the circumferential tooth 12 to the rake surface and is tangent to the circular-arc-shaped rake surface, and the circumferential tooth relief angle 122 extends from the end of the micro-angle blade zone 5 to the relief surface and is tangent to or intersects the circular-arc-shaped relief surface.

[0011] Further, the drilling cutter includes rough machining cutter and finishing cutter, and the difference between the two lies in the arrangement of the end tooth 11 and the circumferential tooth 12 of the cutting portion 1, wherein:

[0012] The number of end teeth 11 of the rough machining cutter is 2, the number of end tooth clearance angles is 2, including an end tooth first clearance angle 111 and an end tooth second clearance angle 112, the end tooth first clearance angle 111 is 15-17°, and the end tooth second clearance angle 112 is 20-22°; the number of circumferential teeth 12 is 2, the circumferential tooth rake angle 121 is 10-11°, the circumferential tooth clearance angle 122 is 16-18°, the circumferential teeth 12 are arranged in a spiral structure along the axial direction, the circumferential tooth spiral angle 123 is 40-42°, and the cutter parameters are suitable for blind hole rough machining.

[0013] The number of end teeth 11 of the rough machining cutter is 2, the number of end tooth clearance angles is 2, including an end tooth first clearance angle 111 and an end tooth second clearance angle 112, the end tooth first clearance angle 111 is 15-17°, and the end tooth second clearance angle 112 is 20-22°; the number of circumferential teeth 12 is 2, the circumferential tooth rake angle 121 is 10-11°, the circumferential tooth clearance angle 122 is 16-18°, the circumferential teeth 12 are arranged in a spiral structure along the axial direction, the circumferential tooth spiral angle 123 is 40-42°, and the cutter parameters are suitable for blind hole rough machining.

[0014] Further, the diameter of the neck portion 2 is smaller than the diameters of the cutting portion 1 and the guide structure 3.

[0015] The application also provides a machining method for wing folding positioning blind hole, which comprises the following steps: drilling a primary hole on a part; rough machining the primary hole by using a rough machining cutter to form a primary blind hole; and then fine machining the primary blind hole by using a fine machining cutter to obtain a final blind hole.

[0016] Further, air is sent to the hole opening during machining, so that the chips are quickly discharged under the action of the air force.

[0017] Further, the air is sent to the hole opening in a radial direction and to the rear of the guide structure 3 of the hole machining cutter in an axial direction, and the air force in the radial direction is greater than that in the axial direction.

[0018] Further, the rotation speed of the hole machining cutter is 3000 rpm, and the feed rate is 600 mm / min.

[0019] The application has the following beneficial effects:

[0020] The application extends a micro-angle blade at the cutting edge of the circumferential tooth of the cutter, reduces the contact area between the cutting edge and the hole wall, and thus reduces the friction between the cutting edge and the hole wall and the cutting resistance. Air is sent to the hole opening during machining, so that the chips are quickly discharged under the action of the air force, the chip winding phenomenon is avoided, and the cutting resistance is further reduced. Moreover, the chips are prevented from entering the gap between the guide bushing and the cutter, and the cutter is prevented from being stuck. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a schematic diagram of the first embodiment of the cutter;

[0022] Figure 2 is a schematic view of the end tooth structure;

[0023] Figure 3 is a schematic view of the peripheral tooth structure;

[0024] Figure 4 is a schematic view of the ventilation groove;

[0025] Figure 5 is a schematic view of the second embodiment of the tool.

[0026] In the figure: 1 cutting part; 11 end tooth; 12 peripheral tooth; 111 first relief angle of end tooth; 112 second relief angle of end tooth; 121 rake angle of peripheral tooth; 122 relief angle of peripheral tooth; 123 helix angle of peripheral tooth; 2 neck; 3 guide structure; 4 tool shank; 5 micro-angle blade; 51 micro-relief angle; 52 width of micro-angle blade; 6 ventilation groove. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application clearer and more obvious, the present application will be described in detail below with reference to the drawings.

[0028] Example 1

[0029] A tool for positioning a blind hole of a wing, Figure 1 shows the overall structure, the hole-making tool can be divided into four cylindrical structures in general. The front end of the hole-making tool is the cutting part 1, which is responsible for cutting metal and removing excess material. The cutting part 1 includes end teeth 11 arranged on the end face, and the end teeth 11 are used to process the bottom surface of the blind hole. As shown in Figure 2 , the end teeth 11 are wedge-shaped and the number is 2. The rake angle of the end teeth 11 extends from the tip of the end teeth 11 to the rake face. The rake angle of the end teeth 11 is attached to the tooth groove and is made together with the tooth groove. The relief angle of the end teeth 11 extends from the tip of the end teeth 11 to the relief face, which reduces the friction between the relief face and the bottom surface of the blind hole. The relief angle of the end teeth 11 is arranged in two angles according to the broken line, the first relief angle 111 of the end teeth is 15°, and the second relief angle 112 of the end teeth is 22°, which can further reduce the friction between the bottom surface of the blind hole and the relief face. The end teeth 11 are not provided with blade structure, which keeps the tip sharp and can reduce the cutting resistance. The peripheral teeth 12 are arranged on the circumferential surface connected with the end teeth 11, and the two are connected through the circular blade. The peripheral teeth 12 are used to process the circumferential hole wall of the blind hole. As shown in Figure 3As shown, the circumferential teeth 12 are arc-shaped, and the number is the same as the end teeth 11. The circumferential teeth 12 are provided with a land at the tool tip, which can stabilize the tool tip size on the one hand, and improve the strength of the tool tip on the other hand, so that the hole-making tool meets the machining requirements of the blind hole diameter. However, the generally set arc-shaped land is in contact with the circumferential hole wall of the blind hole, and the two are in surface contact, which will cause large friction and large cutting resistance. Therefore, in the present embodiment, the land provided at the tool tip of the circumferential teeth 12 is a micro-angle land 5. The micro-angle land 5 is a small relief angle 51 extending from the tool tip to the relief surface. The micro-angle land 5 and the circumferential hole wall of the blind hole are in line contact, which reduces the contact area between the two, reduces the friction, and reduces the cutting resistance. At the same time, the tool tip size can be stabilized by adjusting the value of the small relief angle 51 and the size of the micro-angle land width 52, so that the size tolerance of the circumferential size of the hole-making tool meets the machining requirements of the blind hole diameter. Specifically, the small relief angle 51 is set to 1°, and the micro-angle land width 52 is set to 0.8 mm. The circumferential tooth rake angle 121 extends from the circumferential tooth tip to the rake surface and is tangent to the arc-shaped rake surface, and is set to 10°. The circumferential tooth relief angle 122 extends from the end of the micro-angle land 5 to the relief surface and is tangent or tangent to the arc-shaped relief surface, and is set to 16°. The circumferential teeth 12 are arranged in a spiral structure along the axial direction to improve the chip removal capacity of the hole-making tool. With the rotation of the hole-making tool, the rake surface of the circumferential teeth 12 generates an outward axial force on the chip, which can push the chip out of the hole, and the circumferential tooth spiral angle 123 is 40°, and the rotation direction is right-handed.

[0030] The cutting part 1 is provided with a neck 2 of a certain length at the rear end, and the other end of the neck 2 is connected with the guide structure 3. The diameter of the neck 2 is smaller than the diameters of the cutting part 1 and the guide structure 3, which plays a role of safe transition, avoiding the destruction of the guide structure 3 when the grinding wheel grinds the cutting part 1. The guide structure 3 is cylindrical and fits with the guide bushing of the guide tool in clearance, which plays a role of positioning and guiding. On the circumferential surface of the guide structure 3, a plurality of ventilation grooves 6 are arranged along the axial direction, as shown in Figure 4 The cross section of the ventilation groove 6 is arc-shaped, and the depth of the arc is equal to 3 / 4 of the radius of the arc. The edge line formed at the intersection of the ventilation groove 6 and the guide structure 3 remains sharp, avoiding the chip from being stuck in the gap between the guide structure 3 and the guide bushing from the inside of the ventilation groove 6. A tool shank 4 is arranged at the other end of the guide structure 3, and the hole-making tool is clamped on the automatic hole-making equipment through the tool shank 4 to provide force and torque for blind hole machining. In the present embodiment, the tool shank 4 can be a cylindrical shank. The material of the hole-making tool is selected to be high-speed steel W18Cr4V, the heat treatment hardness of the cutting part 1 is 66, and the heat treatment hardness of the rest is 48. The hole-making tool in the present embodiment has a large chip space and good chip removal performance, and is suitable for rough machining of blind holes.

[0031] Embodiment 2

[0032] Figure 5 The difference between the hole-making tool in the embodiment 2 and the hole-making tool in the embodiment 1 is that the number of the end teeth 11 of the hole-making tool is 4, the first relief angle 111 of the end teeth is 8°, the second relief angle 112 of the end teeth is 27°, the number of the peripheral teeth 12 is 4, the rake angle 121 of the peripheral teeth is 3°, the relief angle 122 of the peripheral teeth is 12°, and the helix angle 123 of the peripheral teeth is 0°. The number of the end teeth 11 and the peripheral teeth 12 is increased in the embodiment, which can reduce the machining allowance of each tooth and make the machining more stable. The parameters of the rake angle and the relief angle of each tooth are adjusted, so that the tooth strength is higher and the wear resistance is better, and the size of the hole-making tool is stable. The helix angle 123 of the peripheral teeth is set to 0°, the helix structure of the peripheral teeth 12 is cancelled, the weakening of the tooth structure by the helical tooth groove is avoided, and the tooth shape is more accurate. Therefore, the hole-making tool in the embodiment is more suitable for the finishing machining of the blind hole.

[0033] Embodiment 3

[0034] Meanwhile, in order to solve the problem of chip removal difficulty and chip jamming in the process of machining the positioning blind hole of the wing butt joint, the application further provides a method for machining the positioning blind hole of the wing butt joint, which comprises the following steps:

[0035] First, drill an initial hole on the part. Drill an initial hole on the wing rib, so that the diameter and depth of the initial hole are smaller than the required size of the positioning blind hole. The initial hole has good positioning accuracy, but does not require high machining accuracy, and is only used to quickly remove the initial machining allowance and improve the hole-making efficiency. The hole-making tool can use a general type of twist drill.

[0036] Then, rough machining is performed on the initial hole to form a blind hole. Based on the initial hole, the hole-making tool in the embodiment 1 is used for further rough machining to remove excess material and form a positioning blind hole with a flat bottom surface, and machining allowances are left on the bottom surface and the peripheral hole wall for subsequent finishing machining. The machining allowance can be set to 0.1mm.

[0037] Finally, the blind hole is finished. The hole-making tool in the embodiment 2 is used to remove the final machining allowance, so that the positioning blind hole reaches the specified process size, the diameter and depth meet the tolerance requirements, and the surface quality of the bottom surface and the hole wall meets the use requirements.

[0038] In the hole making process, in order to make the chip quickly removed, a set of air supply and chip removal system is arranged. A blowing port is arranged between the wing component and the guide tool, air is blown to the port along the radial direction, a tangential force is generated on the chip, the chip can be quickly broken or deviated under the action of the air force when it is removed from the positioning blind hole, and is removed from the gap between the wing component and the guide tool. At the same time, another blowing port is arranged outside the guide tool, air is blown to the port along the axial direction from the rear of the hole making tool guide structure 3, a certain resistance is generated on the chip, the chip can be effectively prevented from entering the gap between the guide bushing and the hole making tool, so that the hole making tool is prevented from being stuck. In other embodiments, the blowing port arranged between the wing component and the guide tool can be replaced by a suction port, so that the chip can be sucked away, the collection and unified management of the chip are facilitated, and the processing is more clean and green.

[0039] In the processing process, the hole making tool rotation speed is set to 3000 rpm, and the feed amount is 600 mm / min.

[0040] The above-mentioned embodiments only express the implementation of the present application, but cannot be understood as the limitation of the scope of the present application patent. It should be pointed out that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application.

Claims

1. A blind borehole tool for winged hinge positioning of a borehole, characterized in that, The hole-making tool comprises a cutting part (1), a neck (2), a guide structure (3) and a tool shank (4); the cutting part (1) is connected with the neck (2), the other end of the neck (2) is provided with the guide structure (3), the other end of the guide structure (3) is connected with the tool shank (4); the cutting part (1) comprises end teeth (11) arranged on an end face and circumferential teeth (12) arranged on a circumferential surface of the cutting part (1), the circumferential teeth (12) are connected with the end teeth (11) through a circular-arc edge, a micro-angle edge belt (5) is arranged at a tool tip of the circumferential teeth (12) and extends, so as to reduce a contact area between the tool tip and a hole wall; a ventilation groove (6) is arranged on an outer wall of the guide structure (3), and an edge line formed at an intersection of the ventilation groove (6) and the outer wall of the guide structure (3) is kept sharp. The micro-angle edge belt (5) is a micro-rake angle (51) arranged at the tool tip and extending to a relief surface, the angle is 1°±30', and a width (52) of the micro-angle edge belt (5) is 0.8-0.9mm. The guide structure (3) is gap-connected with a guide bush of a guide tool.

2. A tool for positioning a blind hole on a wing according to claim 1, characterized in that The end teeth (11) are wedge-shaped and have an end tooth rake angle and an end tooth relief angle, wherein the end tooth rake angle extends from a tool tip of the end teeth (11) to a rake surface, and the end tooth relief angle extends from the tool tip of the end teeth (11) to a relief surface, so as to reduce friction between the relief surface and a bottom surface of a blind hole, the end tooth relief angle is a single angle or a plurality of angles arranged in turn according to a broken line; the circumferential teeth (12) are arc-shaped, the number of the circumferential teeth (12) is the same as that of the end teeth (11), the circumferential teeth (12) have a circumferential tooth rake angle (121) and a circumferential tooth relief angle (122), wherein the circumferential tooth rake angle (121) extends from a tool tip of the circumferential teeth (12) to a rake surface and is tangent to the arc-shaped rake surface, and the circumferential tooth relief angle (122) extends from an end of the micro-angle edge belt (5) to a relief surface and is tangent to or intersects with the arc-shaped relief surface.

3. A tool for the formation of aligned blind holes in a wing according to claim 2, wherein, The hole-making tool comprises a rough machining tool and a finish machining tool, and the difference between the two tools lies in the arrangement of the end teeth (11) and the circumferential teeth (12) of the cutting part (1). The rough machining tool has two end teeth (11) and two end tooth relief angles, including an end tooth first relief angle (111) of 15°-17° and an end tooth second relief angle (112) of 20°-22°; the number of the circumferential teeth (12) is two, the circumferential tooth rake angle (121) is 10°-11°, the circumferential tooth relief angle (122) is 16°-18°, and the circumferential teeth (12) are arranged in a spiral structure along an axial direction, so as to improve the chip removal capacity of the tool, and the circumferential tooth spiral angle (123) is 40°-42°; The finish machining tool has four end teeth (11), an end tooth first relief angle (111) of 8°-10° and an end tooth second relief angle (112) of 25°-27°; the number of the circumferential teeth (12) is four, the circumferential tooth rake angle (121) is 2°-3°, the circumferential tooth relief angle (122) is 12°-14°, and the circumferential tooth spiral angle (123) is 0°.

4. A tool for positioning a blind hole on a wing according to claim 1, characterized in that, The diameter of the neck (2) is smaller than the diameters of the cutting part (1) and the guide structure (3).

5. A method for wing alignment positioning of blind hole machining, accomplished with the hole making tool according to any of claims 1 - 4, characterized in that, The processing method comprises the following steps: drilling a primary hole on a part; rough machining the primary hole to form a primary blind hole; and fine machining the primary blind hole to obtain a final blind hole.

6. A method for wing alignment positioning of blind hole machining according to claim 5, characterized in that, Air is sent to the hole mouth during processing, so that the cutting chips are quickly discharged under the action of the air.

7. A method for wing alignment positioning of blind hole machining according to claim 6, characterized in that, The air sending mode is that air is sent in the radial direction at the hole mouth and air is sent in the axial direction at the rear of the guiding structure (3) of the hole cutter, and the air force of the radial air sending is greater than the air force of the axial air sending.

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