Aviation thermal shrinkage type automatic feeding drilling tool and machining method thereof

Abstract

The embodiment of the invention discloses a thermal shrinkage type automatic feeding drilling tool for aviation and a machining method thereof. The tool structure is an integrated tool structure formed by a tool blade part and a thermal shrinkage threaded tool handle in a thermal shrinkage machining mode. The method for machining the cutter comprises the following steps: firstly, performing linear cutting blanking according to the length of a cutter blade part, aligning two ends of a bar material and punching a center hole, grinding the outer diameter of the cutter blade part to the final size requirement by taking the center hole as a reference, and then machining each cutting parameter of the cutter blade part by using a cutter grinder and a numerical control cutter grinder. And finally, by utilizing the difference between the thermal expansion coefficients of the thermal shrinkage threaded cutter handle and the cutter blade part, the cutter blade part and the thermal shrinkage threaded cutter handle are subjected to thermal shrinkage treatment together, the thermal shrinkage threaded cutter handle is heated to be expanded, then the thermal shrinkage threaded cutter handle is sleeved with the cutter blade part, and the cutter blade part is shrunk and clamped after being cooled. And the threaded cutter handle and the cutter blade part are combined into a whole. Compared with a blade part and a handle part of a traditional high-frequency welding cutter, the technical scheme provided by the embodiment of the invention not only avoids quality risks such as cracks generated in the welding process and greatly improves the yield of the cutter, but also simplifies the technological process and reduces the production period.

Description

Technical Field

[0001] The present invention relates to the technical field of tool processing methods, but is not limited to it, and in particular to a heat shrinkable automatic feed drill tool for aviation and a processing method thereof. Background Art

[0002] With the development of the domestic aviation manufacturing industry, some aircraft have large structures, large hole diameters, a large number of holes, and high assembly difficulty. The demand for semi-automatic hole making tools and supporting tools is increasing year by year. Semi-automatic hole making is generally achieved through automatic feed drills.

[0003] At present, the production and processing of automatic feed drilling tools have the following problems: the outer circle accuracy requirement of the existing automatic feed drilling tools is 0.007-0.01mm, and the coaxiality requirement is 0.01mm. In order to ensure the above accuracy requirements, the tool manufacturing adopts the processing method of "welding first and then grinding". The specific process flow is as follows: Figure 1 The above is a schematic diagram of the processing process of the automatic feeding drilling tool in the prior art. Figure 1 Through analysis of the processing method flow shown in the figure, it was found that the complex process and bottleneck process all originated from the processing of the welded threaded shank. The tool manufacturing process is complicated, and the production cycle is as long as 25 to 30 days. In addition, after high-frequency welding of the 45 steel tail handle and the carbide blade of the welded tool, the carbide part is prone to cracks due to the different shrinkage rates when the materials cool down. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned technical problems. The embodiments of the present invention provide an aviation heat-shrinkable automatic feed drill tool and a processing method thereof, so as to solve the problems of the existing automatic feed drill tool processing technology, the tool manufacturing process is complicated, and the production cycle is long; in addition, due to the high-frequency welding of the steel tail handle and the cemented carbide blade of the tool, the shrinkage rate of the material is different when it cools, which leads to the problem that the cemented carbide part is prone to cracks.

[0005] The technical solution of the present invention: The embodiment of the present invention provides a heat shrinkable automatic feed drill tool for aviation, in which the heat shrinkable automatic feed drill tool has a heat shrinkable threaded shank and a tool blade that are combined in the following manner: according to the difference in thermal expansion coefficients between the heat shrinkable threaded shank and the tool blade, the heat shrinkable threaded shank of the tool is heated to expand, and then the tool blade is installed in the connection end of the heat shrinkable threaded shank that is heated and expanded, and the heat shrinkable threaded shank generates a high-strength radial clamping force after cooling, thereby clamping the tool blade through the heat shrinkable threaded shank that has shrunk after cooling, so that the heat shrinkable threaded shank and the tool blade are combined into a tool with an integrated structure;

[0006] The heat shrink thread tool handle is made of stainless steel with a relatively high thermal expansion coefficient, the tool blade is made of cemented carbide material, and the thermal expansion coefficient of the heat shrink thread tool handle is higher than that of the tool blade.

[0007] The embodiment of the present invention also provides a method for processing a heat shrinkable automatic feed drill tool for aviation.

[0008] Step 1, wire cutting, including: cutting by wire cutting to form a cylindrical bar for machining a tool blade;

[0009] Step 2, centerless external cylindrical grinding is performed on the bar stock of the tool blade, and the bar stock has a first preset grinding amount after rough grinding;

[0010] Step 3: Align the two ends of the bar, use wire cutting to make a center hole at the end of the bar, and ensure that the runout of the center hole is within the preset range;

[0011] Step 4: During benchwork, use a centering tool to grind the center hole, and align the two centers of the benchwork equipment before grinding;

[0012] Step 5, performing common outer cylindrical grinding on the bar material, and after rough grinding each outer circle of the bar material has a second preset grinding amount;

[0013] Step 6, CNC external cylindrical grinding is performed on the bar material, and each external circle of the bar material is finely ground to the preset size of the product, and the bar material meets the runout requirement after fine grinding;

[0014] Step 7, wire cutting to remove the reserved length of the bar at one end of the finely ground bar, and cutting a slot at the other end of the bar;

[0015] Step 8, grinding the handle to make it flat, chamfering the handle, grinding the end surface of the blade to form a visible blade end, and roughly grinding the drill tip;

[0016] Step 9, use a CNC tool grinder to process the bar material according to the drawing until the processed tool blade meets the size requirements of the drawing;

[0017] Step 10, using an air duct to detect the inner coolant holes of the tool blade and the heat shrink threaded tool holder respectively to ensure that the inner coolant holes are not blocked;

[0018] Step 11, heat shrinking the heat shrink threaded tool handle to install the flat handle portion of the tool blade into the assembly hole of the connecting end of the heat shrink threaded tool handle to form a tool with an integrated structure.

[0019] Step 12, align the tool, use a CNC tool grinder to grind the angle surface of the tool shank, and ensure the tool runout.

[0020] Optionally, in the above-mentioned method for processing the heat shrinkable automatic feed drill tool for aviation, in step 1,

[0021] The bar stock formed by cutting is increased by an additional bar stock of a preset length based on the length of the tool blade;

[0022] The step 2 comprises:

[0023] The bar material is rough-ground using a centerless grinding device, and after the rough-grinding is completed, a first preset grinding amount is reserved based on the product size of the tool blade.

[0024] Optionally, in the above-mentioned method for processing the heat shrinkable automatic feed drill tool for aviation, in step 3,

[0025] Align the center points of the two end faces of the bar after centerless external cylindrical grinding in step 2. For example, when the central axis of the entire bar is parallel to the horizontal plane, a hole is punched on the additional end face of the bar with a reserved length in the bar by wire cutting to form a center hole; and ensure that the runout of the center hole is within a preset range.

[0026] Optionally, in the above-mentioned method for processing the aviation heat shrinkable automatic feed drill tool, the step 5 comprises:

[0027] A common cylindrical grinder is used to perform rough grinding on the bar stock, and after the rough grinding is completed, a second preset grinding amount is reserved based on the product size of each outer circle of the tool blade; wherein the bar stock of the tool blade is a cylindrical bar stock or a cylindrical bar stock with a multi-step structure, and the second preset grinding amount is less than the first preset grinding amount;

[0028] The step 6 comprises:

[0029] The bar is finely ground using a CNC cylindrical grinder to the set size of the product, and the bar after fine grinding meets the runout requirements.

[0030] Optionally, in the above-mentioned method for processing the aviation heat shrinkable automatic feed drill tool, the step 7 comprises:

[0031] By adopting the wire cutting method, the additional bar part is removed from one end of the additional bar with a preset length, and the end face of the flat handle of the bar is cut to form an open groove.

[0032] Optionally, in the above-mentioned method for processing the aviation heat shrinkable automatic feed drill tool, step 8 comprises:

[0033] The flat shank portion of the bar material used to form the tool blade, which is connected to the heat shrink threaded shank, is ground flat, and the outer periphery of the end surface of the ground flat shank portion is chamfered; the other end of the bar material is ground to form a visible blade end, and the drill tip of the blade end is roughly ground.

[0034] Optionally, in the above-mentioned processing method of the heat shrink type automatic feed drill tool for aviation, a groove is provided on the end surface of the flat handle end of the tool blade, and a boss is processed on the opposite end surface of the heat shrink threaded tool handle; in the step 11,

[0035] The flat shank portion of the tool blade and the connecting end of the heat shrink threaded tool handle are connected by heat shrinkage, including: first, turning on the heat shrinkage device and inserting the heat shrink threaded tool handle into the tool accessory of the heat shrinkage device; secondly, moving the coil inner cover plate of the heat shrinkage device so that it contacts one end of the heat shrink threaded tool handle inserted into the tool accessory; after heating for a preset time, in the heated state of the heat shrink threaded tool handle, the flat shank portion of the tool blade is inserted into the corresponding assembly hole of the connecting end of the heat shrink threaded tool handle until the flat shank portion of the tool blade is completely inserted into the assembly hole of the connecting end of the heat shrink threaded tool handle, and the heat shrinkage process is completed.

[0036] Optionally, in the above-mentioned processing method of the heat shrink type automatic feed drill tool for aviation,

[0037] The connecting end of the heat shrinkable threaded tool handle is provided with an assembly hole, and the assembly hole is processed into a structure that matches the flat shank portion of the tool blade; it expands in a heated state so as to facilitate the installation of the flat shank portion of the tool blade into the assembly hole of the heat shrinkable threaded tool handle, and the connecting end of the heat shrinkable threaded tool handle shrinks after cooling, so that a high-strength radial clamping force is generated between the flat shank portion of the tool blade and the connecting end of the heat shrinkable threaded tool handle, so that the heat shrinkable threaded tool handle and the tool blade form a tool handle and blade of an integrated structure.

[0038] Beneficial effects of the present invention: The embodiment of the present invention provides a heat-shrinkable automatic feed drilling tool for aviation and a processing method thereof. In the processing method of the tool, the difference in thermal expansion coefficients between the tool blade and the heat-shrinkable threaded tool holder is utilized, and the heat-shrinkable threaded tool holder of the tool is heated to expand by high-energy density induction heating, and the tool blade in the heated state is installed into the connecting end of the heated and expanded heat-shrinkable threaded tool holder. After the heat-shrinkable threaded tool holder is cooled, a high-strength radial clamping force is generated, so that the tool blade is clamped by the shrunk heat-shrinkable threaded tool holder, so that the heat-shrinkable threaded tool holder and the tool blade are combined into a tool with an integrated structure. The processing method of the tool provided by the embodiment of the present invention realizes the transformation of the automatic feed drilling tool from the traditional welding manufacturing process to the heat-shrinking process, which has the following beneficial effects:

[0039] (1) Compared with the traditional welding type automatic feed drill tool manufacturing process, the heat shrink type automatic feed drill tool provided by the embodiment of the present invention does not need to go through the high-frequency welding process, thereby avoiding the quality risks such as thermal cracks and ablation that may be generated, improving the yield rate of the tool, reducing the energy-consuming and time-consuming complex processes such as optical grinding, thread grinding and shank heat treatment, and shortening the process flow and manufacturing cycle;

[0040] (2) The heat shrink thread shank of the heat shrink automatic feed drilling tool can adopt several commonly used standard thread structures. The heat shrink thread shank and the tool blade are assembled together after heat shrink treatment. The shank and blade can be combined according to different automatic feed drilling requirements, thereby improving the versatility of the tool and the shank. The shank can be reused, which is convenient for production management.

[0041] (3) The processing method of the tool provided in the embodiment of the present invention optimizes the process flow, reduces energy-consuming and time-consuming complex processes such as optical grinding, thread grinding and handle heat treatment, and greatly shortens the process flow and manufacturing cycle. The process flow of the tool is reduced from 23 processes to 12 processes, and the manufacturing cycle is reduced from 25 to 30 days to 7 to 10 days. The tool delivery cycle is shortened by 75%, and the versatility of the tool blade and heat-shrinkable threaded tool handle is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0043] Figure 1 The above is a schematic diagram of the processing process of the automatic feed drilling tool in the prior art;

[0044] Figure 2 A flow chart of a method for processing a heat shrinkable automatic feed drill tool for aviation provided by an embodiment of the present invention;

[0045] Figure 3 To adopt Figure 1 A schematic diagram of the structure of a tool blade formed by a method for processing a heat shrinkable automatic feed drill tool for aviation provided in the illustrated embodiment;

[0046] Figure 4 , which is a parameter diagram of a heat shrinkable automatic feed drilling tool provided by an embodiment of the present invention;

[0047] Figure 4 The parameter information in the axial schematic diagram of the tool formed by the processing method of the heat shrinkable automatic feed drill tool for aviation according to the second embodiment of the present invention;

[0048] Figure 5 The parameter information in the radial schematic diagram of the tool formed by the processing method of the heat shrinkable automatic feed drill tool for aviation according to the second embodiment of the present invention; Figure 5 Figure a shows the parameters of the tool blade, Figure b shows the parameters of the flat handle, and Figure c shows the parameters of the drill tip.

[0049] Figure 6This is a schematic diagram of parameters of a tool blade portion in a tool formed by a processing method of a heat shrinkable automatic feed drill tool for aviation according to Embodiment 2 of the present invention;

[0050] Figure 7 This is a schematic diagram of a method for machining a tool blade opening groove using a heat shrink type automatic feed drill tool for aviation according to Embodiment 2 of the present invention. Figure 7 Figure a is the main view and figure b is the left view. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0052] As described in the above background technology, the demand for semi-automatic hole making tools and matching tools in the aviation manufacturing industry has increased year by year, and semi-automatic hole making is generally achieved by automatic feed drilling. Figure 1 The conventional automatic feed drill tool is manufactured by a processing method of "welding first and then grinding". Figure 1 The problems of the existing processing method shown are: first, the tool manufacturing process is complicated and the production cycle is as long as 25 to 30 days; second, after the 45 steel tail handle and the cemented carbide blade of the welded tool are high-frequency welded, the cemented carbide part is prone to cracks due to the different shrinkage rates when the materials cool.

[0053] In order to avoid the various problems caused by the processing of the above-mentioned automatic feed drill tools, it is urgently needed to provide a new connection method for processing the automatic feed drill tools; based on this demand, the embodiment of the present invention provides an aviation heat-shrinkable automatic feed drill tool and a processing method thereof, which utilizes the difference in thermal expansion coefficients between the tool shank and the tool blade to achieve the combination of the tool shank and the tool as a whole, thereby eliminating the generation of high-frequency welding cracks and achieving the purpose of shortening the production cycle; the method provided by the embodiment of the present invention can be used to solve the problem of cracks caused by different shrinkage rates of the blade and shank materials during high-frequency welding, thereby shortening the process flow and manufacturing cycle.

[0054] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0055] Example 1

[0056] This embodiment 1 provides an aviation heat shrinkable automatic feed drill tool and a processing method thereof, Figure 2 A flowchart of a method for processing a heat shrinkable automatic feed drill tool for aviation provided by an embodiment of the present invention, Figure 3 To adopt Figure 1The illustrated embodiment is a schematic structural diagram of a tool blade formed by a method for processing a heat shrinkable automatic feed drill tool for aviation.

[0057] The embodiment of the present invention provides a heat shrinkable automatic feed drill tool, and the principle of its heat shrink processing technology is: utilizing the difference in thermal expansion coefficients between the heat shrinkable threaded shank of the tool and the tool blade, the heat shrinkable threaded shank of the tool is heated to expand by high energy density induction heating, and then the tool blade is installed in the heated and expanded heat shrinkable threaded shank connection end. After the heat shrinkable threaded shank is cooled, a high-strength radial clamping force is generated, so that the tool blade is clamped by the heat shrinkable threaded shank after cooling and shrinking, so that the heat shrinkable threaded shank and the tool blade are combined into a tool with an integrated structure. The process flow of the tool processing method in the embodiment of the present invention is as follows Figure 2 , specifically including the following steps:

[0058] Step 1: Wire cutting;

[0059] In step 1, wire cutting is used to cut the bar stock for machining the tool blade; wherein the cut bar stock is lengthened by 5 mm based on the length of the tool blade. In the specific implementation, based on the preset length of the tool blade, the preset length is lengthened based on the end of the blade, which is used for positioning machining in the subsequent conventional external cylindrical grinding and CNC external cylindrical grinding of the bar stock. Figure 3 At the top of the tool blade (i.e. Figure 3 The additional bar stock (center left end) is formed into a reserved length.

[0060] Step 2: Centerless external cylindrical grinding;

[0061] In step 2, the bar is rough ground using a centerless grinding device. The rough grinding allowance in this step is: 0.3 to 0.4 mm is reserved based on the product size of the tool blade. It should be noted that the centerless grinding device used in this step does not require reference positioning when performing rough grinding, and can be directly fed into the device for rough grinding. Therefore, this step has no reference positioning point, and the rough grinding process in this step is short in time and highly efficient.

[0062] Step 3: Align both ends of the bar and use wire cutting to drill the center hole.

[0063] In this step, the two end faces of the bar material after the centerless external cylindrical grinding in step 2 are aligned, that is, the centers of the two end faces are aligned, for example, the central axis of the entire bar material is parallel to the horizontal plane, and the wire cutting method is used to punch holes on the additional bar end faces with a reserved length in the bar material to form a center hole. In addition, the process standard of this step is the runout index of the center hole, that is, the runout of the center hole is within 0.15, and the horizontal state of the center axis of the bar material is guaranteed by this runout index. In the specific implementation, the depth range of the center hole is 2.5-3.5mm

[0064] Step 4: During bench work, use a centering tool to grind the center hole, and align the two centers of the bench equipment before grinding.

[0065] In this step, the fitter construction worker uses the fitter tool to grind the center hole formed in step 3, and before grinding, the two opposite tips in the fitter tool are required to be in an aligned state.

[0066] Step 5: Ordinary external cylindrical grinding;

[0067] In this step, a common cylindrical grinder is used to roughly grind the bar stock, specifically, each outer circle in the bar stock is roughly ground, and each outer circle has a grinding amount of 0.1-0.15mm. It should be noted that the tool edge in the embodiment of the present invention is not limited to Figure 3 The blade structure described in the invention is an outer circle with only one diameter size; in an optional embodiment, the blade of the tool in the embodiment of the invention can also be a multi-step structure, and accordingly, the rod to be processed is also a cylindrical rod with a multi-step structure. Therefore, different diameter areas in the rod need to be subjected to ordinary external cylindrical grinding respectively to form a multi-step rod with a preset grinding amount.

[0068] Step 6: CNC external cylindrical grinding, fine grinding of each external circle to the requirements, ensuring the runout requirements;

[0069] In this step, a CNC cylindrical grinder is used to fine-grind the bar stock, specifically fine-grinding each outer circle in the bar stock, and the size of each outer circle in the fine-grinded bar stock is the set size of the product, and the bar stock after fine grinding is required to meet the runout requirements.

[0070] It should be noted that the external cylindrical grinding in the above steps 5 and 6 needs to be performed with the center hole of the additional rod end of the reserved length on the rod as the reference point.

[0071] Step 7: Use wire cutting to remove the extended portion of the bar and cut a slot at the other end.

[0072] In this step, wire cutting is used to remove the additional rod part at one end of the rod having a preset length, and an open groove is cut to form the flat shank end face at the other end of the rod. It should be noted that the open groove is used to guide the smooth flow of coolant in the two-part structure after the subsequent heat shrinkage processing of the tool blade and the heat shrinkable thread blade.

[0073] Step 8: Grind the handle to make it flat, chamfer the handle, grind the end face of the blade to form a shiny edge, and roughly grind the drill tip.

[0074] In this step, the flat shank portion of the bar material used to form the tool blade connected to the heat shrink threaded shank is ground flat, and the outer periphery of the end surface of the flat shank portion is chamfered, such as Figure 3The right end of the tool blade is formed with a chamfered flat handle, which is easier to be installed into the connecting end of the heat-shrinkable threaded tool handle in the heated expansion state; in addition, in this step, the end face of the tool blade is also ground to form a visible blade end, and the drill tip of the blade end is roughly ground, such as Figure 3 The left end drill tip position of the middle tool cutting edge.

[0075] Step 9: Use a CNC tool grinder to process the blade according to the drawing until the processed tool blade meets the size requirements of the drawing.

[0076] In this step, the bar is machined so that the tool blade forms a spiral cutting edge and a drill tip.

[0077] Step 10: Check the coolant holes on the tool edge and shrink-fit thread holder.

[0078] It should be noted that the raw materials used to form the tool blade and the heat shrink thread handle, for example, the bar has a through hole along the axial direction, which is the internal coolant hole of the bar, and is used to cool down by filling coolant during the processing. In this step, the internal coolant holes on the tool blade and the heat shrink thread handle are detected by using an air duct, such as Figure 5 The through holes on the end faces from Figure a to Figure c must be free of blockage of the internal coolant holes.

[0079] Step 11: Heat shrink the heat shrink threaded tool handle to install the flat handle of the tool blade into the assembly hole of the connecting end of the heat shrink threaded tool handle to form an integrated structure of the blade and the tool handle.

[0080] Through the steps, a groove has been opened on the end surface of the flat handle end of the tool blade, and a boss has been processed on the opposite end surface of the heat shrink thread handle.

[0081] In this step, the flat shank portion of the tool blade and the end of the tool heat shrink thread handle are connected by heat shrinking, including: first, turning on the heat shrink device, inserting the heat shrink thread handle into the tool accessory of the heat shrink device, and then moving the coil inner cover plate of the heat shrink device to make it contact with one end of the heat shrink thread handle inserted into the tool accessory. After heating for 5 to 8 seconds, in the heated state of the heat shrink thread handle, the flat shank portion of the tool blade is installed into the corresponding assembly hole of the heat shrink thread handle connecting end. The heat shrink assembly process assists the clamping process by heating the heat shrink thread handle until the flat shank portion of the tool blade is completely installed in the assembly hole of the heat shrink thread handle connecting end, and the heat shrink processing is completed. The heat shrink processing process in the embodiment of the present invention realizes the transformation of the automatic feeding drilling tool from the traditional welding manufacturing process to the heat shrink process.

[0082] It should be noted that, through this heat shrink processing method, the flat shank portion of the tool blade is installed into the assembly of the heat shrink threaded shank connecting end, and a high-strength radial clamping force is generated after cooling, so that the heat shrink threaded shank of the tool and the tool blade form an integrated shank and blade, that is, a tool with an integrated structure; in addition, after the tool blade and the heat shrink threaded shank form an integrated structure, the open groove on the end face of the flat shank portion of the tool blade is located at the connecting portion, which is used to communicate the cooling holes of the two structures, so that coolant can circulate during the use of the automatic feed drill tool.

[0083] Step 12: Alignment, use CNC tool grinder to grind the angle surface of tool tail handle.

[0084] In this step, a CNC tool grinder is used to grind the angle surface of the tail handle of the integrated structure tool. In this step, it is required to ensure that the runout of the integrated structure tool is within 0.02.

[0085] Example 2

[0086] This embodiment 2 is a processing method for a heat shrinkable automatic feed drill tool for aviation. In this embodiment, a certain type of specific automatic feed drill tool is used as a research object, and a processing process is implemented. Figure 4 The parameter information in the axial schematic diagram of the tool formed by the processing method of the heat shrinkable automatic feed drill tool for aviation in Example 2 of the present invention is as follows: Figure 5 The parameter information in the radial schematic diagram of the tool formed by the processing method of the heat shrinkable automatic feed drill tool for aviation in Example 2 of the present invention is as follows: Figure 5 Figure a shows the parameters of the tool blade, Figure b shows the parameters of the flat handle, and Figure c shows the parameters of the drill tip. Figure 6 This is a schematic diagram of the parameters of the tool blade in the tool formed by the processing method of the heat shrink type automatic feed drill tool for aviation in Example 2 of the present invention. Figure 2 The process flow shown specifically includes the following steps:

[0087] Step 1: Cutting with wire cutting, the total length of the tool blade is 167.8 mm, of which the drill tip at the end of the tool blade (e.g. Figure 3 The leftmost end of the middle tool blade) is lengthened by 5mm. Figure 4 shown.

[0088] Step 2: Perform centerless external cylindrical grinding on the bar material, rough grinding the bar material, the tool product requirement is φ12.39mm size, and the grinding allowance is 0.3-0.4mm.

[0089] Step 3: Align both ends of the bar, and use wire cutting to drill a center hole on the end face of the bar by extending the drill tip of the bar. The depth of the center hole ranges from 2.5 to 3.5 mm.

[0090] Step 4: During benchwork, use a centering tool to grind the center hole. Before grinding, align the two centers of the benchwork equipment.

[0091] Step 5: Perform ordinary external grinding on the bar material, rough grinding the outer circle of the bar material, the tool product size is required to be φ12.39mm, and the grinding allowance is 0.1-0.15;

[0092] Step 6: CNC external grinding of the bar material, fine grinding the outer circle of the bar material to the size requirement of φ12.39mm, and ensure that the runout is within 0.01, such as Figure 6 shown.

[0093] Step 7: Cut off the 5mm extension of the blade by wire cutting, and cut a groove at one end of the flat handle. The groove position is symmetrical with the end surface, the groove depth is 2mm, and the groove width is 2.5mm. Figure 7 FIG. 2 is a schematic diagram of a method for machining a tool blade opening groove using a heat shrink type automatic feed drill tool for aviation according to Embodiment 2 of the present invention. Figure 7 Figure a is the main view and figure b is the left view.

[0094] Step 8: Grind the handle to make it flat, chamfer the handle, grind the end face of the blade to form a shiny edge, and roughly grind the blade to a 120° drill tip.

[0095] Step 9: Use a CNC sharpening machine to process the blade according to the drawing until the processed tool blade meets the size requirements of the drawing; the processing parameters in this step are as follows: Figure 4 and Figure 5 shown.

[0096] Step 10: For the tool blade and heat shrink threaded tool holder, use the air duct detection method to check the coolant hole inside the tool blade to ensure that there is no blockage.

[0097] Step 11: Heat shrink the heat shrink thread handle;

[0098] The processing method of this step is to first turn on the heat shrink device, insert the heat shrink thread tool holder into the tool accessory of the heat shrink device, and then move the coil inner cover plate of the heat shrink device to make it contact one end of the heat shrink thread tool holder inserted into the tool accessory, heat it for 7s, and in the heated state of the heat shrink thread tool holder, install the flat handle part of the tool blade into the corresponding assembly hole of the connecting end of the heat shrink thread tool holder. During the heat shrink assembly process, the clamping process is assisted by heating the heat shrink thread tool holder until the flat handle part of the tool blade is completely installed in the assembly hole of the connecting end of the heat shrink thread tool holder, and the heat shrink processing is completed.

[0099] Step 12: Alignment: Use CNC tool grinder to grind the angle surface of tool tail handle to ensure the runout is within 0.02.

[0100] The above-mentioned embodiments of the present invention provide a heat-shrinkable automatic feed drilling tool for aviation and a processing method thereof. In the processing method of the tool, the difference in thermal expansion coefficient between the tool blade and the heat-shrinkable threaded tool holder is utilized, and the heat-shrinkable threaded tool holder of the tool is heated to expand by high-energy density induction heating, and the tool blade in the heated state is installed into the connecting end of the heated and expanded heat-shrinkable threaded tool holder. After the heat-shrinkable threaded tool holder is cooled, a high-strength radial clamping force is generated, so that the tool blade is clamped by the shrunk heat-shrinkable threaded tool holder, so that the heat-shrinkable threaded tool holder and the tool blade are combined into a tool with an integrated structure. The processing method of the tool provided by the embodiment of the present invention realizes the transformation of the automatic feed drilling tool from the traditional welding manufacturing process to the heat-shrinking process, which has the following beneficial effects:

[0101] (1) Compared with the traditional welding type automatic feed drill tool manufacturing process, the heat shrink type automatic feed drill tool provided by the embodiment of the present invention does not need to go through the high-frequency welding process, thereby avoiding the quality risks such as thermal cracks and ablation that may be generated, improving the yield rate of the tool, reducing the energy-consuming and time-consuming complex processes such as optical grinding, thread grinding and shank heat treatment, and shortening the process flow and manufacturing cycle;

[0102] (2) The heat shrink thread shank of the heat shrink automatic feed drilling tool can adopt several commonly used standard thread structures. The heat shrink thread shank and the tool blade are assembled together after heat shrink treatment. The shank and blade can be combined according to different automatic feed drilling requirements, thereby improving the versatility of the tool and the shank. The shank can be reused, which is convenient for production management.

[0103] (3) The processing method of the tool provided in the embodiment of the present invention optimizes the process flow, reduces energy-consuming and time-consuming complex processes such as optical grinding, thread grinding and handle heat treatment, and greatly shortens the process flow and manufacturing cycle. The process flow of the tool is reduced from 23 processes to 12 processes, and the manufacturing cycle is reduced from 25 to 30 days to 7 to 10 days. The tool delivery cycle is shortened by 75%, and the versatility of the tool blade and heat-shrinkable threaded tool handle is improved.

[0104] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A heat shrinkable automatic feed drill tool for aviation, characterized in that: In the heat-shrinkable automatic feed drill tool, the heat-shrinkable threaded tool holder and the tool blade are combined in the following manner: according to the difference in thermal expansion coefficients between the heat-shrinkable threaded tool holder and the tool blade, the heat-shrinkable threaded tool holder is heated to expand, and then the tool blade is installed in the heated and expanded heat-shrinkable threaded tool holder connection end, and the heat-shrinkable threaded tool holder generates a high-strength radial clamping force after cooling, so that the tool blade is clamped by the heat-shrinkable threaded tool holder after cooling and shrinking, so that the heat-shrinkable threaded tool holder and the tool blade are combined into a tool with an integrated structure; The heat shrink thread tool handle is made of stainless steel with a relatively high thermal expansion coefficient, the tool blade is made of cemented carbide material, and the thermal expansion coefficient of the heat shrink thread tool handle is higher than that of the tool blade.

2. A method for processing a heat shrinkable automatic feed drill tool for aviation, characterized in that: Step 1, wire cutting, including: cutting by wire cutting to form a cylindrical bar for machining a tool blade; Step 2, centerless external cylindrical grinding is performed on the bar stock of the tool blade, and the bar stock has a first preset grinding amount after rough grinding; Step 3: Align the two ends of the bar, use wire cutting to make a center hole at the end of the bar, and ensure that the runout of the center hole is within the preset range; Step 4: During benchwork, use a centering tool to grind the center hole, and align the two centers of the benchwork equipment before grinding; Step 5, performing common outer cylindrical grinding on the bar material, and after rough grinding each outer circle of the bar material has a second preset grinding amount; Step 6, CNC external cylindrical grinding is performed on the bar material, and each external circle of the bar material is finely ground to the preset size of the product, and the bar material meets the runout requirement after fine grinding; Step 7, wire cutting to remove the reserved length of the bar at one end of the finely ground bar, and cutting a slot at the other end of the bar; Step 8, grinding the handle to make it flat, chamfering the handle, grinding the end surface of the blade to form a visible blade end, and roughly grinding the drill tip; Step 9, use a CNC tool grinder to process the bar material according to the drawing until the processed tool blade meets the size requirements of the drawing; Step 10, using an air duct to detect the inner coolant holes of the tool blade and the heat shrink threaded tool holder respectively to ensure that the inner coolant holes are not blocked; Step 11, heat shrinking the heat shrink threaded tool handle to install the flat handle portion of the tool blade into the assembly hole of the connecting end of the heat shrink threaded tool handle to form a tool with an integrated structure. Step 12, align the tool, use a CNC tool grinder to grind the angle surface of the tool shank, and ensure the tool runout.

3. The method for processing the heat shrinkable automatic feed drill tool for aviation according to claim 2, characterized in that: In the step 1, The bar stock formed by cutting is increased by an additional bar stock of a preset length based on the length of the tool blade; The step 2 comprises: The bar material is rough-ground using a centerless grinding device, and after the rough-grinding is completed, a first preset grinding amount is reserved based on the product size of the tool blade.

4. The method for processing the heat shrinkable automatic feed drill tool for aviation according to claim 3, characterized in that: In step 3, Align the center points of the two end faces of the bar after centerless external cylindrical grinding in step 2. For example, when the central axis of the entire bar is parallel to the horizontal plane, a hole is punched on the additional end face of the bar with a reserved length in the bar by wire cutting to form a center hole; and ensure that the runout of the center hole is within a preset range.

5. The method for processing the heat shrinkable automatic feed drill tool for aviation according to claim 4, characterized in that: The step 5 comprises: A common cylindrical grinder is used to perform rough grinding on the bar stock, and after the rough grinding is completed, a second preset grinding amount is reserved based on the product size of each outer circle of the tool blade; wherein the bar stock of the tool blade is a cylindrical bar stock or a cylindrical bar stock with a multi-step structure, and the second preset grinding amount is less than the first preset grinding amount; The step 6 comprises: The bar is finely ground using a CNC cylindrical grinder to the set size of the product, and the bar after fine grinding meets the runout requirements.

6. The method for processing the heat shrinkable automatic feed drill tool for aviation according to claim 5, characterized in that: The step 7 comprises: By adopting the wire cutting method, the additional bar part is removed from one end of the additional bar with a preset length, and the end face of the flat handle of the bar is cut to form an open groove.

7. The method for processing the heat shrinkable automatic feed drill tool for aviation according to claim 6, characterized in that: The step 8 comprises: The flat shank portion of the bar material used to form the tool blade, which is connected to the heat shrink threaded shank, is ground flat, and the outer periphery of the end surface of the ground flat shank portion is chamfered; the other end of the bar material is ground to form a visible blade end, and the drill tip of the blade end is roughly ground.

8. The method for processing the heat shrinkable automatic feed drill tool for aviation according to claim 7, characterized in that: A groove is provided on the end surface of the flat handle end of the tool blade, and a boss is processed on the opposite end surface of the heat shrink thread handle; in step 11, The flat shank portion of the tool blade and the connecting end of the heat shrink threaded tool handle are connected by heat shrinkage, including: first, turning on the heat shrinkage device and inserting the heat shrink threaded tool handle into the tool accessory of the heat shrinkage device; secondly, moving the coil inner cover plate of the heat shrinkage device so that it contacts one end of the heat shrink threaded tool handle inserted into the tool accessory; after heating for a preset time, in the heated state of the heat shrink threaded tool handle, the flat shank portion of the tool blade is inserted into the corresponding assembly hole of the connecting end of the heat shrink threaded tool handle until the flat shank portion of the tool blade is completely inserted into the assembly hole of the connecting end of the heat shrink threaded tool handle, and the heat shrinkage process is completed.

9. The method for processing the heat shrinkable automatic feed drill tool for aviation according to claim 8, characterized in that: The connecting end of the heat shrinkable threaded tool handle is provided with an assembly hole, and the assembly hole is processed into a structure that matches the flat shank portion of the tool blade; it expands in a heated state so as to facilitate the installation of the flat shank portion of the tool blade into the assembly hole of the heat shrinkable threaded tool handle, and the connecting end of the heat shrinkable threaded tool handle shrinks after cooling, so that a high-strength radial clamping force is generated between the flat shank portion of the tool blade and the connecting end of the heat shrinkable threaded tool handle, so that the heat shrinkable threaded tool handle and the tool blade form a tool handle and blade of an integrated structure.

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