Manual dimpling method applied to elliptical hole in inclined plane

Abstract

According to the technical scheme, the manual dimpling method applied to the oval opening hole in the inclined plane comprises the steps that firstly, according to a drawing of a workpiece 1 and dimpling technical requirements, material characteristics, structural characteristics and dimpling machining data of the machined workpiece 1 are determined; 2, the structural size and parameters of a dimple tool 6 are determined; 3, determining structural parameters of a dimple limiter 7 according to the structural size and parameters of the dimple cutter 6; 4, according to the manufacturing material and strength of the workpiece 1, proper rotating speed parameters of a power device 4 are determined; 5, determining the structural form of the compensation cushion block 2 according to the structural parameters of the dimple limiter 7; step 6, determining the structural form of the adapter 5 according to the tail handle thread of the dimple cutter 6; 7, the compensation cushion block 2 is positioned according to the structural form of the compensation cushion block 2; and 8, dimpling is conducted on the workpiece 1.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft assembly drilling, in particular to a manual counterboring method applied to an oblique surface elliptical hole. BACKGROUND

[0002] In the process of aircraft assembly, double countersunk riveting is a fastening method between aircraft workpieces. Through double countersunk riveting, not only can the aircraft workpieces be firmly connected together to ensure the stability and safety of the aircraft structure, but also the riveting part can be flush with the aircraft surface to form a smooth surface, thereby reducing air resistance and improving the flight performance and fuel efficiency of the aircraft. Before double countersunk riveting, drilling and counterboring operations need to be performed on the workpiece, and the stability of counterboring directly affects the riveting quality of double countersunk rivets. Conventional double countersunk riveting is mostly used for riveting of two parallel surfaces, and drilling and counterboring operations can be performed using conventional methods. However, for oblique surface counterboring, i.e. counterboring with a bottom hole axis that is not perpendicular to the surface of the workpiece, there is currently no suitable counterboring process method. A large number of oblique surface double countersunk riveting processes are used in certain aircraft components. When using conventional methods to manually counterbore on the oblique surface of the workpiece, it is difficult to stably and continuously ensure the angle with the oblique surface and the depth of the counterbore, often causing the depth, diameter and surface roughness of the counterbore to deviate too much, and the flushness of the rivet and the surface quality of the product contour after riveting do not meet the technical requirements, often resulting in rework or even scrap workpieces, affecting the production progress and product quality of the aircraft. Therefore, the present application proposes a manual counterboring method applied to an oblique surface elliptical hole to solve this problem. SUMMARY

[0003] The present application provides a manual counterboring method applied to an oblique surface elliptical hole, which is used to solve the problem that in the prior art, when manually counterboring on an oblique surface, it is difficult to ensure the angle between the counterboring tool and the oblique surface, and the counterbore depth cannot be accurately and stably controlled, thereby affecting the flushness of the double countersunk rivet after installation and the surface quality of the product contour.

[0004] The technical solution of the present application provides a manual counterboring method applied to an oblique surface elliptical hole, which comprises the following steps: Step 1: According to the technical requirements of the workpiece 1 drawing and counterboring, determine the material properties, structural properties and counterboring processing data of the workpiece 1 to be processed; Step 2: Determine the structure size and parameters of the counterboring tool 6; Step 3: According to the structure size and parameters of the counterboring tool 6, determine the structure parameters of the counterboring stopper 7; Step 4: According to the manufacturing material and strength of the workpiece 1, determine the appropriate speed parameter of the power device 4; Step 5: According to the structure parameters of the counterboring stopper 7, determine the structure form of the compensation pad 2; Step 6: Determine the structure of the adapter 5 according to the tail shank thread of the countersinking tool 6; Step 7: Position the compensation pad 2 according to its structure; Step 8: Countersink the workpiece 1.

[0005] Specifically, step 1 includes: Step 1-1: Determine the material properties, manufacturing material and strength of the workpiece 1 to be processed; Step 1-2: determining the bevel angle α of the bevel surface of the processed part of the workpiece 1 relative to the reference plane; Step 1-3: Determine the countersink depth h based on the countersink bottom hole diameter d, the countersink angle θ, and the countersink outer diameter D.

[0006] Specifically, step 2 includes: Step 2-1: Select the manufacturing material of the countersinking tool 6 based on the material properties, manufacturing material and strength of the workpiece 1; Step 2-2: Determine the structure of the countersink tool 6 to be used based on the countersink bottom hole diameter d, the countersink angle θ, the countersink outer diameter D, and the countersink depth h. The structure of the countersink tool 6 includes the outer diameter of the tool shank of the countersink tool 6 and the leading diameter of the countersink tool 6. Step 2-3: Determine the tail shank form of the countersinking tool 6.

[0007] Specifically, step 3 includes: Step 3-1: Determine the inner and outer diameters of the countersinking stopper 7 based on the outer diameter of the countersinking tool 6. The inner diameter of the countersinking stopper 7 is larger than the outer diameter of the countersinking tool 6 to ensure that the countersinking tool 6 can rotate flexibly within the countersinking stopper 7. Step 3-2: Determine the connection form of the matching countersinking stopper 7 according to the tail shank form of the countersinking tool 6; Step 3-3: Determine the expansion and contraction amount of the countersink limiter 7 according to the countersink depth. The expansion and contraction amount of the countersink limiter 7 is greater than the maximum countersink depth to avoid insufficient machining stroke.

[0008] Specifically, step 5 includes: Step 5-1: Determine the slope angle of the compensation pad 2 as 90°-α according to the slope angle α; Step 5-2: Determine the inner diameter of the countersunk keyway 3 on the compensation pad 2.

[0009] Specifically, step 6 includes: Step 6-1: Determine the length of the adapter 5; specifically, the minimum depth of the countersink keyway 3 on the compensation pad 2 is used as the length of the adapter 5, and the length is adjusted according to the rod length of the countersink tool 6; Step 6-2: Determine the connection form of the adapter 5.

[0010] Specifically, step 6-2 includes: One end of the adapter 5 is connected to the countersink limiter 7, and the other end is connected to the countersink tool 6, wherein the tightening direction of the adapter 5 and the countersink limiter 7 is the same as the tightening direction of the countersink tool 6 and the adapter 5, ensuring that the countersink tool 6 will not loosen during countersinking.

[0011] Specifically, step 7 includes: The inclined surface of the compensation pad 2 fits the inclined surface of the workpiece 1, the reference plane on the workpiece 1 is parallel to the plane of the compensation pad 2, the countersunk keyway 3 on the compensation pad 2 is concentric with the countersunk bottom hole on the workpiece 1, and the compensation pad 2 is fixed so that the angle between the axis of the bottom hole of the workpiece 1 and the compensation plane of the compensation pad 2 is 90°.

[0012] Specifically, step 8 includes: Step 8-1: Assemble the countersinking tool 6, the adapter 5, and the countersinking stopper 7, and then adjust the processing depth of the countersinking tool 6 by adjusting the countersinking stopper 7; Step 8-2: Connect the countersinking limiter 7 and the power device 4, and hold the power device 4 to perform the countersinking operation; Step 8-3: Check whether the surface roughness of the countersink is qualified, specifically using a roughness detection tool; Step 8-4: Check whether the countersink depth is qualified.

[0013] Specifically, the tail handle is connected with the countersink limiter 7 and can also be connected with one end of the adapter 5 .

[0014] To sum up, the present invention provides a manual countersinking method for elliptical holes on inclined surfaces, which uses compensation pads to compensate the inclined surface into a parallel plane, ensuring that the countersinking tool is perpendicular to the compensation plane, and then accurately controlling the angle between the countersinking tool and the bottom hole of the countersink on the inclined surface, thereby solving the problem in the prior art that it is difficult to ensure the angle between the countersinking tool and the inclined surface during manual countersinking.

[0015] The present invention combines a countersinking tool with a countersinking tool length adapter in a design so that for countersinking in different depth areas, there is no need to design countersinking tools of matching lengths. The countersinking tool length can be adjusted by simply replacing or removing the countersinking tool length adapter, thereby realizing countersinking operations under different depth working conditions, greatly reducing the types of countersinking tools, and using one tool for multiple purposes, saving the cost of manufacturing the countersinking tools.

[0016] The present invention improves the stability of the countersink depth, the cavity diameter and the surface roughness of the countersink by accurately calculating and measuring the countersink depth and using a countersink limiter to ensure the stability and accuracy of the countersink process, thereby ensuring the flushness of the double-buried rivet after installation and the surface quality of the product's outline.

[0017] The present invention is particularly suitable for preparing oblique countersunk rivet sockets on non-parallel planes in the field of aircraft manufacturing, and significantly improves the surface quality and flight performance of the aircraft's aerodynamic shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of a manual countersinking method for an elliptical hole on an inclined surface provided by the present invention; Figure 2 A schematic diagram of the compensation pad in the present invention; Figure 3 Schematic diagram of the countersinking method of the present invention; Explanation of numbers in the figure: 1-workpiece, 2-compensating pad, 3-counterface keyway, 4-power device, 5-adapter, 6-counterface tool, 7-counterface limiter. DETAILED DESCRIPTION

[0019] See also Figure 1 、 Figure 2 and Figure 3 The present invention provides a manual countersinking method for elliptical holes on inclined surfaces. According to the workpiece drawing and the countersinking technical requirements, the material properties, structural properties and countersinking processing data of the workpiece 1 to be processed are determined, and then the structural dimensions and parameters of the countersinking tool 6, the structural parameters of the countersinking limiter 7, the parameters of the power unit 4, the structural form of the compensation pad 2 and the countersinking keyway 3, and the structural form of the adapter 5 for countersinking tool compensation are confirmed. Then, the compensation pad 2 is positioned, the countersinking tool 6, the adapter 5, and the countersinking limiter 7 are combined, and the power unit 4 is connected to perform the countersinking processing operation.

[0020] The present invention provides a manual countersinking method for an elliptical hole on an inclined surface, comprising the following steps: Step 1: Determine the material properties, structural properties and countersink processing data of the workpiece 1 according to the workpiece 1 drawing and countersink technical requirements; Step 2: Determine the structural dimensions and parameters of the countersinking tool 6; Step 3: Determine the structural parameters of the countersinking stopper 7 according to the structural dimensions and parameters of the countersinking tool 6; Step 4: Determine the appropriate speed parameters of the power device 4 based on the manufacturing material and strength of the workpiece 1; Step 5: Determine the structural form of the compensation pad 2 according to the structural parameters of the countersink limiter 7; Step 6: Determine the structure of the adapter 5 according to the tail shank thread of the countersinking tool 6; Step 7: Position the compensation pad 2 according to its structure; Step 8: Countersink the workpiece 1.

[0021] Specifically, step 1 includes: Step 1-1: Determine the material properties, manufacturing material, and strength of the workpiece 1 to be processed.

[0022] In practical applications, the manufacturing material and strength of the workpiece 1 are determined based on the drawing data.

[0023] It should be noted that the workpiece 1 is a part with an inclined surface.

[0024] Step 1-2: Determine the slope angle α of the slope surface of the machined portion of the workpiece 1 relative to the reference plane.

[0025] In practical applications, the bevel angle α can be determined by using workpiece drawings or by measuring with an angle measuring instrument.

[0026] Step 1-3: Determine the countersink depth h based on the countersink bottom hole diameter d, the countersink angle θ, and the countersink outer diameter D.

[0027] Specifically, the countersink depth h is calculated using the formula Calculation shows that, D is the outer diameter of the countersink, that is, the maximum outer circle projection diameter of the countersink parallel to the workpiece reference plane; the diameter of the bottom hole of the countersink is d, and θ is the countersink angle.

[0028] In practical applications, the bottom hole diameter d, the countersink angle θ, and the outer diameter D of the countersink on the inclined surface of the workpiece 1 can be determined through drawing materials and drilling technical data.

[0029] It should be noted that the countersink depth is calculated by the countersink angle, countersink outer diameter and countersink bottom hole diameter to ensure accurate calculation of the countersink depth, improve the dimensional accuracy of the countersink, and make the countersink depth meet the design requirements, thereby ensuring the flushness of subsequent rivet installation and the surface quality of the product's appearance and contour.

[0030] Specifically, step 2 includes: Step 2-1: Select the manufacturing material of the countersinking tool 6 according to the material properties, manufacturing material and strength of the workpiece 1.

[0031] Preferably, the material strength of the countersinking tool 6 is greater than the material strength of the workpiece 1 .

[0032] Usually when the processed material is aluminum alloy, ordinary high-speed steel or cobalt-containing high-speed steel is selected; when the processed material is titanium alloy, stainless steel, or steel parts, alloy steel is preferred, and coatings such as fine steel stone can be attached.

[0033] Step 2-2: Determine the structural form of the countersink tool 6 used based on the bottom hole diameter d of the countersink, the countersink angle θ, the outer diameter D of the countersink, and the depth h of the countersink. The structural form of the countersink tool 6 includes the outer diameter of the tool shank of the countersink tool 6 and the leading diameter of the countersink tool 6.

[0034] Specifically, the outer diameter of the cutter bar of the counterbore cutter 6 is 2-4 mm larger than the maximum outer diameter of the counterbore. The pilot diameter of the counterbore cutter 6 is 0.03-0.05 mm smaller than the size of the bottom hole of the workpiece counterbore, so that the counterbore cutter 6 can rotate freely in the hole without damaging the bottom hole; the pilot length of the counterbore cutter 6 is designed to meet the requirement that the cutting edge of the counterbore cutter is 1-3 mm above the workpiece processing surface, and the pilot can be inserted into the depth d of the counterbore bottom hole, d being the diameter of the counterbore bottom hole, so as to ensure the stability of the counterbore cutter.

[0035] Step 2-3: Determine the form of the shank of the counterbore cutter 6.

[0036] Specifically, the shank can be connected with the counterbore limiter 7 or connected with one end of the adapter 5.

[0037] In practical application, the counterbore limiter 7 usually has two connection forms, i.e., metric screw thread connection and inch screw thread connection, the metric specifications are M6x1 and M8x1, and the inch specification is 1 / 4"-28F inch.

[0038] Specifically, step 3 includes: Step 3-1: According to the outer diameter of the cutter bar of the counterbore cutter 6, determine the inner diameter and outer diameter of the counterbore limiter 7. The inner diameter of the counterbore limiter 7 is larger than the outer diameter of the counterbore cutter 6, so that the counterbore cutter 6 can rotate freely in the counterbore limiter 7.

[0039] Step 3-2: According to the form of the shank of the counterbore cutter 6, determine the connection form of the matching counterbore limiter 7.

[0040] Step 3-3: According to the counterbore depth, determine the extension amount of the counterbore limiter 7, which is larger than the maximum value of the counterbore depth, so as to avoid insufficient processing stroke.

[0041] Specifically, step 4 includes: According to the manufacturing material and strength of the workpiece 1, determine the appropriate rotation speed parameter of the power device 4.

[0042] Generally, for processing soft aluminum alloy material, a power device 4 with a rotation speed of 800-2000 rpm / min is selected; for processing hard aluminum alloy material, a power device 4 with a rotation speed of 1500-3500 rpm / min is selected; for processing titanium alloy material, a power device 4 with a rotation speed of 200-600 rpm / min is selected.

[0043] Specifically, step 5 includes: Step 5-1: According to the bevel angle α, determine the bevel angle 90°-α of the compensation pad 2.

[0044] Step 5-2: Determine the inner diameter of the counterbore key groove 3 on the compensation pad 2.

[0045] The inner diameter size of the counterbore key groove 3 on the compensation pad 2 is greater than the outer diameter size of the shank of the counterbore tool 6 in step 2-2, so as to ensure the counterbore space; and the inner diameter size of the counterbore key groove 3 on the compensation pad 2 is smaller than the outer diameter size of the counterbore limiter 7 in step 3, so as to ensure that the counterbore limiter 7 is supported during counterboring.

[0046] Specifically, step 6 includes: Step 6-1: determining the length of the adapter 5. Specifically, the minimum depth of the counterbore key groove 3 on the compensation pad 2 is taken as the length of the adapter 5, and the length is adjusted according to the length of the shank of the counterbore tool 6, so as to ensure that the front blade of the counterbore tool 6 is 1-3 mm above the surface of the workpiece 1 during counterboring, but does not touch the counterboring surface of the workpiece 1. Specifically, the depth of the counterbore key groove 3 can be measured by a depth gauge.

[0047] Step 6-2: determining the connection form of the adapter 5. One end of the adapter 5 is connected with the counterbore limiter 7, and the other end is connected with the counterbore tool 6. The tightening direction of the adapter 5 and the counterbore limiter 7 is the same as the tightening direction of the counterbore tool 6 and the adapter 5, so as to ensure that the counterbore tool 6 does not loosen during counterboring.

[0048] Specifically, step 7 includes: the inclined surface of the compensation pad 2 is attached to the inclined surface of the workpiece 1, the reference plane on the workpiece 1 is parallel to the plane of the compensation pad 2, the counterbore key groove 3 on the compensation pad 2 is concentric with the counterbore bottom hole on the workpiece 1, and the compensation pad 2 is fixed, so that the angle between the bottom hole axis of the workpiece 1 and the compensation plane of the compensation pad 2 is 90°.

[0049] Specifically, step 8 includes: Step 8-1: combining the counterbore tool 6, the adapter 5 and the counterbore limiter 7, and then adjusting the processing depth of the counterbore tool 6 by adjusting the counterbore limiter 7.

[0050] During the first processing, the processing depth is adjusted to the minimum counterbore depth, so as to prevent the problem of counterboring depth.

[0051] Step 8-2: connecting the counterbore limiter 7 with the power device 4, and performing counterboring operation by holding the power device 4.

[0052] Step 8-3: detecting whether the counterbore surface roughness is qualified or not. Specifically, the roughness detection tool is used for detection.

[0053] Step 8-4: detecting whether the counterbore depth is qualified or not.

[0054] Since the counterbore depth and the counterbore diameter are guaranteed simultaneously by the counterbore tool 6, after the counterbore depth size is qualified, the counterbore diameter size can also be guaranteed simultaneously.

[0055] Specifically, the countersink depth is measured using a depth detection tool. If it does not meet the requirements, the countersink tool 6 is fine-tuned using the countersink limiter 7 according to the deviation between the measured countersink depth and the theoretical countersink depth, and the work is repeated until the countersink depth meets the requirements.

[0056] After application in aircraft component assembly, the accuracy of the countersink depth and surface roughness of rivet holes on beveled surfaces have been significantly improved, with consistent countersink quality. The flushness of the rivets and the surface quality of the product's contours after riveting meet the requirements of drawings and technical documentation, avoiding unnecessary rework and even scrapping of workpieces, and improving overall product quality.

Claims

1. A manual countersinking method for elliptical holes on inclined surfaces, characterized in that: Methods include: Step 1: Determine the material properties, structural properties and countersink processing data of the workpiece (1) according to the workpiece (1) drawing and countersinking technical requirements; Step 2: Determine the structural dimensions and parameters of the countersinking tool (6); Step 3: Determine the structural parameters of the countersinking stopper (7) according to the structural dimensions and parameters of the countersinking tool (6); Step 4: Determine the appropriate speed parameters of the power device (4) based on the manufacturing material and strength of the workpiece (1); Step 5: Determine the structural form of the compensation pad (2) based on the structural parameters of the countersink limiter (7); Step 6: Determine the structural form of the adapter (5) according to the tail shank thread of the countersinking tool (6); Step 7: Position the compensation pad (2) according to the structure of the compensation pad (2); Step 8: Countersink the workpiece (1).

2. The method according to claim 1, characterized in that Specifically, step 1 includes: Step 1-1: Determine the material properties, manufacturing material and strength of the workpiece (1); Step 1-2: determining the bevel angle α of the bevel surface of the processed part of the workpiece (1) relative to the reference plane; Step 1-3: Determine the countersink depth h based on the countersink bottom hole diameter d, the countersink angle θ, and the countersink outer diameter D.

3. The method according to claim 1, characterized in that Step 2 includes: Step 2-1: Select the manufacturing material of the countersinking tool (6) based on the material properties, manufacturing material and strength of the workpiece (1); Step 2-2: Determine the structure of the countersink tool (6) to be used according to the countersink bottom hole diameter d, the countersink angle θ, the countersink outer diameter D, and the countersink depth h. The structure of the countersink tool (6) includes the outer diameter of the tool bar of the countersink tool (6) and the leading diameter of the countersink tool (6); Step 2-3: Determine the shank shape of the countersinking tool (6).

4. The method according to claim 1, characterized in that Step 3 includes: Step 3-1: Determine the inner diameter and outer diameter of the countersinking tool (6) according to the outer diameter of the tool shank; the inner diameter of the countersinking tool (7) is larger than the outer diameter of the countersinking tool (6) to ensure that the countersinking tool (6) can rotate flexibly in the countersinking tool (7); Step 3-2: Determine the connection form of the matching countersinking stopper (7) according to the tail shank form of the countersinking tool (6); Step 3-3: Determine the expansion and contraction amount of the countersink limiter (7) according to the countersink depth. The expansion and contraction amount of the countersink limiter (7) is greater than the maximum countersink depth to avoid insufficient machining stroke.

5. The method according to claim 1, characterized in that Step 5 includes: Step 5-1: According to the bevel angle α, determine the bevel angle of the compensation pad (2) as 90°-α; Step 5-2: Determine the inner diameter of the countersunk keyway (3) on the compensation pad (2).

6. The method according to claim 1, characterized in that Step 6 includes: Step 6-1: Determine the length of the adapter 5; specifically, the minimum depth of the countersink keyway 3 on the compensation pad 2 is used as the length of the adapter (5), and is adjusted according to the rod length of the countersink tool (6); Step 6-2: Determine the connection form of the adapter 5.

7. The method according to claim 6, characterized in that Step 6-2 includes: One end of the adapter 5 is connected to the countersinking stopper 7, and the other end is connected to the countersinking tool (6), wherein the tightening direction of the adapter 5 and the countersinking stopper 7 is the same as the tightening direction of the countersinking tool (6) and the adapter (5), ensuring that the countersinking tool (6) will not loosen during countersinking.

8. The method according to claim 1, characterized in that Step 7 includes: The inclined surface of the compensation pad (2) is fitted with the inclined surface of the workpiece (1), the reference plane on the workpiece (1) is parallel to the plane of the compensation pad (2), the countersunk keyway (3) on the compensation pad (2) is concentric with the countersunk bottom hole on the workpiece (1), and the compensation pad (2) is fixed so that the angle between the axis of the bottom hole of the workpiece (1) and the compensation plane of the compensation pad (2) is 90 degrees.

9. The method according to claim 1, characterized in that Step 8 includes: Step 8-1: Assemble the countersinking tool (6), the adapter (5), and the countersinking stopper (7), and then adjust the processing depth of the countersinking tool (6) by adjusting the countersinking stopper 7; Step 8-2: Connect the countersinking limiter (7) and the power device (4), and hold the power device (4) to perform the countersinking operation; Step 8-3: Check whether the surface roughness of the countersink is qualified, specifically using a roughness detection tool; Step 8-4: Check whether the countersink depth is qualified.

10. The method according to claim 1, characterized in that The tail handle is connected in cooperation with the countersink limiter (7), or is connected in cooperation with one end of the adapter (5).

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