Aviation casing sealing thread plug removing method

Abstract

The invention belongs to the technical field of numerical control machining. The invention particularly relates to an aviation casing sealing thread plug removing method. The method comprises the following steps that firstly, the cartridge receiver is installed on a machine tool, and the approximate position of an installation hole with a to-be-removed threaded plug is determined; secondly, a center hole is drilled in the threaded plug; thirdly, a threaded bottom hole is machined on the basis of the center hole through a drill bit; 4, boring the threaded bottom hole by using a boring cutter until the area of the hole wall exposed out of the spiral line layer is greater than an area threshold value; 5, removing thread plug residues in an opening area by using a needle knife; and 6, a screw tap is selected to enter the mounting hole to remove thread plug residues in the hole.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of numerical control machining, and particularly relates to an aviation case sealing screw plug removal method. BACKGROUND

[0002] At present, internal oil passage blockage or partial sealing position leakage often occurs in the repair of aviation case products. Sealing screw plugs need to be removed for flushing and inspection. Since the sealing plugs are smeared with anaerobic glue when being screwed in, the plugs cannot be removed by using a bench tool, and are prone to breakage and thread failure, thereby causing the whole case to be scrapped. Therefore, a method for removing the sealing screw plugs without damage is needed. SUMMARY

[0003] The application aims to provide an aviation case sealing screw plug removal method, which can prevent the breakage of plugs and the failure of thread holes during the manual removal of sealing screw plugs by a bench worker in the repair of aviation cases, and ensure that the threads are still effective after the removal of the screw plugs and that the original sealing state is maintained after the replacement of new screw plugs.

[0004] TECHNICAL SCHEME An aviation case sealing screw plug removal method comprises the following steps. Step 1: Install the case on a machine tool, and determine the approximate position of the installation hole of the screw plug to be removed according to the relative reference during the machining of the screw thread of the case. Step 2: Drill a center hole on the screw plug. Step 3: Use a drill bit to process a thread bottom hole on the basis of the center hole. Step 4: Use a boring tool to perform boring processing on the thread bottom hole until the area of the layer of helical lines exposed on the hole wall is greater than an area threshold. Step 5: Use a needle tool to remove the residual screw plug in the opening area. Step 6: Use a tap to select into the installation hole to remove the residual screw plug in the hole.

[0005] Further, in step 1, the approximate position of the installation hole is determined according to the auxiliary reference on the case.

[0006] Further, in step 2, a D3 center drill is used to drill a center hole on the screw plug. A plurality of point positions are selected on the edge of the screw plug, and the distances of the point positions from the center hole are measured; the point positions are uniformly selected along the edge of the screw plug, and the number of the point positions is not less than four. If the distance difference of any two point positions from the center hole is not greater than 0.25 mm, the center hole meets the requirements; otherwise, the center hole is milled flat, and the center hole is re-drilled after compensation in the opposite direction according to the distance difference.

[0007] Further, in step three, a drill bit is used to process the threaded bottom hole; the outer diameter of the drill bit = the threaded plug small diameter - H; the value range of H is 0.5mm~1mm.

[0008] Further, in step four, the boring tool processing process is as follows: Step a: measure the threaded bottom hole diameter R; Step b: boring size T = R + 0.1mm; Step c: use the boring tool to process the threaded bottom hole; Step d: observe whether the threaded bottom hole wall after processing appears spiral layering, if yes, go to step e, if not, return to step a; Step e: observe whether the area of spiral layering appears exceeds the area threshold, if yes, the boring process is finished, otherwise go to step f; Step f: re-measure the threaded bottom hole diameter R1; calculate the offset P, P = (R1 - installation hole theoretical small diameter) / 2; Step g: compensate the center position of the boring tool in the coordinate system according to the offset P; at the same time, adjust the boring size T to T = 2|P| + R1; return to step c.

[0009] Further, in step e, the area threshold is that at least four fifths along the circumferential direction exposes spiral layering.

[0010] Further, in step five, the needle knife size is: D3*15° Further, the size of the tap matches the installation hole thread.

[0011] Beneficial effects: An aviation case sealing threaded plug removal method can remove the sealing threaded plug from the case with the least damage, and the threaded hole after removal can be reassembled with the threaded plug and ensure the sealing performance of the thread. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The schematic diagram of the threaded plug is AG6*1. DETAILED DESCRIPTION The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0013] Using CNC machining to remove the thread seal plug, using the corresponding reference calculation and center drilling to determine the approximate position of the thread. Then use a drill bit with a diameter 0.5mm smaller than the thread to process the thread plug. After processing, use a boring cutter to process the remaining part until the thread minor diameter is processed. Then use a needle to remove the remaining thread of the orifice part, and then use a tap to process it. This can remove the entire thread plug while ensuring the integrity of the thread profile.

[0014] The steps are as follows: 1) Clamping the workpiece on the machine tool and determining the position of the thread; Step one: Clamping the machine case on the machine tool, and determining the approximate position of the installation hole of the thread plug to be removed according to the relative reference when machining the thread of the machine case.

[0015] Step two: Using a center drill to pre-drill a center hole on the thread plug, measuring the distance between the center hole point and the edge of the thread plug in each direction; the measurement points are evenly distributed and not less than four.

[0016] Step three: If the distance difference between any two points is not greater than 0.25mm, the center hole meets the requirements. Otherwise, mill the center hole again according to the measurement difference after compensation in the opposite direction.

[0017] 2) Processing the thread plug Step one: Using a drill bit to process the thread plug. The outer diameter of the drill bit is 0.5mm smaller than the minor diameter of the thread plug. Measure the hole diameter R of the processed thread plug.

[0018] Step two: Using a boring cutter to process the threaded hole after drilling. The first boring size is R plus 0.1mm; Observe whether the thread hole wall after processing has spiral layering; If so, measure the thread hole diameter R1; If not, increase the boring hole diameter by 0.1mm and continue processing until spiral layering appears.

[0019] Step three: Subtract the measured hole diameter R1 in step two from the theoretical installation hole minor diameter r 小 Then divide by two to get the offset P of the processed hole. Compensate the center position of the boring cutter in the coordinate system by the offset P. At the same time, increase the boring cutter diameter by twice the absolute value of the offset. Until at least four-fifths of the hole along the circumferential direction exposes spiral layering.

[0020] 3) Remove the remaining thread plug Step one: Use a needle to remove the remaining part of the orifice thread plug.

[0021] Step two: Use a tap that matches the thread of the installation hole to enter along the orifice part to remove the remaining part of the thread plug inside the thread profile and anaerobic glue.

[0022] Embodiment For example, remove the thread plug of a sealed pipe thread AG6*1. Figure 1 As shown: 1) Clamping the workpiece on the machine tool and determining the thread position; Step one Clamping the workpiece on the machine tool and determining the approximate position of the thread according to the relative reference when machining the thread of the machine case.

[0023] Step two Use D3 center drill to pre-drill the center hole. After drilling, measure the distance between the center drill point and the edge of the thread plug in each direction, which should not be greater than 0.25MM. If it is greater, compensate according to the difference.

[0024] 2) Machining the thread plug Step one Use Φ4.5 drill bit to machine the thread plug. Remove the excess amount and measure the hole diameter after machining.

[0025] Step two Use a boring tool to machine the thread bottom hole. The first boring size is the hole diameter after drilling plus 0.1MM, i.e. Φ4.6, and observe whether there are spiral line layers in the machined hole. In this way, increase the hole diameter by 0.1MM each time until spiral line marks are found on one side of the hole. At this time, measure the hole diameter.

[0026] Step three The hole diameter measured in step two minus the theoretical thread bottom hole diameter and divided by two, for example, if Φ4.7 is found in the positive direction of the X axis, then (5-4.7) / 2=0.15 Add this 0.15 offset in the negative direction of the X axis in the coordinate system. At the same time, 0.15*2=0.3, increase the boring tool diameter by 0.3mm. At this time, four fifths of the hole will expose spiral lines.

[0027] 3) Remove the remaining thread plug Step one Use D3*15° needle to remove the remaining part of the orifice thread plug.

[0028] Step two Use AG6*1 tap to enter along the orifice part to remove the remaining residual of the thread plug in the thread profile.

[0029] The above is only a specific embodiment of the present application, which is described in detail. The parts not described in detail are conventional technologies. However, the protection scope of the present application is not limited to this. Any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the present application. The protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for removing a thread plug from an aircraft casing seal, characterized in that: Here are the steps: Step 1: Install the casing on the machine tool and determine the approximate location of the mounting hole where the threaded plug is to be removed; Step 2: Drill a center hole on the threaded plug; Step 3: Use a drill to machine the threaded bottom hole based on the center hole; Step 4: Use a boring tool to bore the thread bottom hole until the area of ​​the spiral layer exposed on the hole wall is greater than the area threshold; Step 5: Use a needle knife to remove the remaining thread plug in the opening area; Step 6: Use a tap to insert into the mounting hole to remove the remaining thread plug in the hole.

2. The method according to claim 1, wherein: In step one, determine the approximate location of the mounting hole based on the auxiliary reference on the receiver.

3. The method according to claim 1, wherein: In step 2, a center hole is drilled in the center of the threaded plug using a center drill; Select multiple points on the edge of the thread plug and measure the distance between each point and the center hole; select points evenly along the edge of the thread plug, with the number of points being no less than four; If the distance difference between any two points and the center hole is no more than 0.5mm, the center hole meets the requirements; otherwise, the center hole is milled flat and re-drilled after compensating in the opposite direction according to the distance difference.

4. The method according to claim 1, wherein: In step three, use a drill to machine the threaded bottom hole; the drill outer diameter = thread plug minor diameter - H; the value range of H is 0.5mm~1mm.

5. The method according to claim 1, wherein: In step 4, the boring tool processing process is as follows: Step a: Measure the diameter R of the thread bottom hole; Step b: Boring size T=R+0.1mm; Step c: Use a boring tool to process the thread bottom hole; Step d: Observe whether the threaded bottom hole wall after processing has spiral line delamination. If so, proceed to step e; if not, return to step a; Step e: Observe whether the area of ​​the spiral delamination exceeds the area threshold. If so, the boring process ends; otherwise, proceed to step f. Step f: Re-measure the thread bottom hole diameter R1; Calculate the offset P, P = (R1-theoretical diameter of the mounting hole) / 2; Step g: Compensate the center position of the boring tool in the coordinate system according to the offset P; at the same time, adjust the boring size T to T=2|P|+R1; return to step c.

6. The method according to claim 5, characterized in that: In step e, the area threshold is that at least four-fifths of the spiral layer is exposed along the circumferential direction.

7. The method according to claim 1, wherein: In step five, the needle knife size is.

8. The method according to claim 1, wherein: The tap size matches the mounting hole threads.

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