Reaming cutter

Abstract

The invention relates to the technical field of machining tools, in particular to a reaming tool. The broaching tool comprises a tool handle and a cutting part which are connected, the cutting part comprises a first broaching tool, a second broaching tool and a third broaching tool which are connected to form a stepped structure, and the third broaching tool is connected with the tool handle. The diameters of the first expanding reamer, the second expanding reamer and the third expanding reamer are gradually increased, the machining amount of the second expanding reamer is larger than that of the first expanding reamer and that of the third expanding reamer, and the tool cutting edge angle of the second expanding reamer is larger than that of the first expanding reamer and that of the third expanding reamer. And the cutting part forms a stepped reaming cutter, so that the cutting force in the manual drilling process is reduced. The machining amount and the tool cutting edge angle of the cutting part have the characteristics that the head section is small, the middle section is large and the tail section is small, so that the single-step tool machining amount of the broaching tool is reasonably adjusted, and the hole forming efficiency of manual hole forming is guaranteed. And by reducing the cutting force of the third reaming cutter, the sudden change of the instant feeding amount of the heterogeneous laminated structure at an interface during manual drilling is reduced, and the drilling quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining tools, in particular to a reaming tool. BACKGROUND

[0002] In the machining and manufacturing of aircraft, large aircraft structural parts made of a heterogeneous laminated structure of composite materials and alloys (usually titanium alloys) can withstand high stress alternating loads, high temperature differences, strong corrosion and other complex and harsh environments during flight for a long time, and thus are often used to manufacture main load-bearing structural parts of critical parts of the aircraft. The main load-bearing structural parts need to process a large number of connecting holes. In addition to the open and good working conditions that can use automatic hole making equipment, some narrow locations still use manual hole making methods.

[0003] In the process of manual hole making, the contact area between the reaming tool and the heterogeneous laminated structure (the part to be punched) is large, which increases the cutting force in the hole making process, increases the difficulty and length of manual hole making, and reduces the hole making efficiency. At the same time, in the process of machining large holes (hole diameter greater than 10mm) of the heterogeneous laminated structure, the parameters of the small hole machining tool are usually used to design and manufacture large hole reaming tools with a diameter greater than 10mm, so that the large hole reaming tool designed by the parameters of the small hole machining tool usually has problems such as large cutting force, high temperature and long time in the hole making process, which leads to a decrease in hole making quality; if the single-step reaming amount is further reduced, the tool specification and process will be increased. SUMMARY

[0004] The purpose of the present application is to provide a reaming tool to reduce the cutting force in the process of manual hole making, adjust the machining amount of the reaming tool, and improve the hole making efficiency and quality.

[0005] To achieve this purpose, the technical solution adopted by the present application is:

[0006] The reaming tool comprises a handle and a cutting part connected thereto, the cutting part comprises a first reaming tool, a second reaming tool and a third reaming tool connected in a stepped structure, and the third reaming tool is connected to the handle.

[0007] The diameters of the first reaming tool, the second reaming tool and the third reaming tool gradually increase, the machining amount of the second reaming tool is greater than that of the first reaming tool and the third reaming tool, and the tool main deflection angle of the second reaming tool is greater than that of the first reaming tool and the third reaming tool.

[0008] As a preferred scheme, the machining amount of the first reaming tool is 0.2mm-0.4mm, the machining amount of the second reaming tool is 0.4mm-0.6mm, and the machining amount of the third reaming tool is 0.2mm-0.4mm.

[0009] The tool major offset angle of the first reaming expander is 45-60 degrees, the tool major offset angle of the second reaming expander is 80-90 degrees, and the tool major offset angle of the third reaming expander is 45-60 degrees.

[0010] As a preferred scheme, the rake angle of the cutting edge of the first reaming expander, the second reaming expander and the third reaming expander is 8-12 degrees, the relief angle of the cutting edge is 12-25 degrees, and the width of the peripheral relief surface of the cutting edge is 1.8-2.0 mm.

[0011] As a preferred scheme, the first reaming expander, the second reaming expander and the third reaming expander are all inverted taper reaming expanders, the taper of the first reaming expander and the second reaming expander is 0.01-0.05, and the taper of the third reaming expander is 0.01-0.02.

[0012] As a preferred scheme, the initial cutting position of the cutting edge of the first reaming expander, the second reaming expander and the third reaming expander is provided with a blade structure.

[0013] As a preferred scheme, the cutting portion further comprises a guide column, the guide column is integrally connected to one end of the first reaming expander away from the second reaming expander, and the diameter of the guide column is smaller than the diameter of the first reaming expander.

[0014] As a preferred scheme, the cutting portion is provided with a plurality of chip removal grooves in the circumferential direction, the chip removal grooves are extended from one end of the third reaming expander away from the second reaming expander to the end of the guide column away from the first reaming expander.

[0015] As a preferred scheme, the spiral angle of the chip removal groove is 0-8 degrees, the groove rake angle of the chip removal groove is 10-15 degrees, the maximum diameter of the cutting portion is D3, and the groove depth of the chip removal groove is 0.45D3-0.65D3.

[0016] As a preferred scheme, the surface of the chip removal groove is a polished surface, and the roughness of the polished surface is not greater than 0.4 microns.

[0017] As a preferred scheme, the shank is provided with at least two cutting planes in the circumferential direction, and the cutting planes are extended to one end of the shank away from the cutting portion.

[0018] The beneficial effects of the present application are:

[0019] The reaming tool provided by the application has the advantages that the first reamer, the second reamer and the third reamer have gradually increasing diameters, the cutting part is formed as a stepped reamer, the step-by-step reaming is realized, the cutting edges of the cutting part do not simultaneously contact the heterogeneous laminated structure, the cutting force in the manual hole making process is reduced, and the hole making efficiency of the manual hole making is improved. The second reamer has relatively large machining amount and tool main offset angle, the machining amount and the main offset angle of the cutting part are characterized by small first section, large middle section and small tail section, the machining amount of the single-step tool of the reaming tool is reasonably adjusted, and the hole making efficiency of the manual hole making is ensured. The first section (the first reamer) has small machining amount, and a small tool main offset angle is matched to reduce the cutting force at the beginning of cutting, so that the reaming tool smoothly enters the preformed hole of the heterogeneous laminated structure at the initial cutting stage, and the stability of the manual hole making process is improved. The middle section (the second reamer) has relatively large machining amount and tool main offset angle, the machining amount of the single-step tool of the cutting part is increased, and the hole making efficiency of the manual hole making is improved. The tail section (the third reamer) has the same machining amount and tool main offset angle as the first section, the machining amount and the tool main offset angle of the tail section are relatively small, the cutting force of the third reamer is reduced, the instantaneous feed amount mutation of the interface of the heterogeneous laminated structure in the manual hole making process is weakened, and the hole making quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a front view of the reaming tool provided by the embodiment of the application;

[0021] Figure 2 is a structural schematic view of the reaming tool provided by the embodiment of the application;

[0022] Figure 3 is Figure 2 is an enlarged view of the local structure at A in the middle.

[0023] The component names and numbers in the figure are as follows:

[0024] 1, shank; 11, cutting plane; 2, cutting part; 20, cutting edge; 201, edge belt structure; 21, first reamer; 22, second reamer; 23, third reamer; 24, guide column; 25, tool withdrawal groove; 251, extension; 3, chip removal groove. DETAILED DESCRIPTION

[0025] To make the technical problems solved by the application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the application are further described below in combination with the drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the application, rather than limit the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for the convenience of description, rather than all parts.

[0026] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0028] In the description of the present embodiment, the terms "up", "down", "right", "left" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in description, and have no special meaning.

[0029] The technical solutions of the present application will be further illustrated below in conjunction with the drawings and through specific embodiments.

[0030] In the processing and manufacturing of aircraft, large aircraft structural parts made of composite materials and titanium alloy hetero-laminated structure need to process a large number of connecting holes, and the narrow position of the hetero-laminated structure is still processed by manual drilling.

[0031] In the process of manual drilling, the contact area of the reaming tool with the hetero-laminated structure is large, which increases the cutting force in the drilling process, increases the difficulty and length of manual drilling, and reduces the drilling efficiency. At the same time, in the process of machining large holes of the hetero-laminated structure, the parameters of small hole machining tools are usually used to design and manufacture large hole reaming tools with a diameter greater than 10mm, which causes the large hole reaming tool to have problems such as large cutting force, high temperature and long time in drilling, resulting in a decrease in drilling quality; if the single-step reaming amount is further reduced, the tool specification and process will be increased.

[0032] To solve the above problems, such as Figure 1and Figure 2 As shown in the drawings, the embodiment proposes a reaming tool for the manual machining process of a connecting hole of a heterogeneous laminated structure. The reaming tool is clamped by a clamping tool such as an air drill, so as to perform reaming machining on a preformed hole on the heterogeneous laminated structure, and finally prepare a connecting hole with a set size.

[0033] Specifically, the reaming tool comprises a shank 1 and a cutting part 2 connected with each other, and the cutting part 2 comprises first, second and third reaming cutters 21, 22 and 23 connected in a stepped structure, and the third reamer 23 is connected with the shank 1. The diameters of the first, second and third reaming cutters 21, 22 and 23 gradually increase, the machining amount of the second reamer 22 is greater than that of the first and third reaming cutters 21 and 23, and the tool main offset angle of the second reamer 22 is greater than that of the first and third reaming cutters 21 and 23. It should be noted that the machining amount is the cutting amount (or double-sided machining amount) of the cutting edge 20 of the three reaming cutters.

[0034] Since the diameters of the first, second and third reaming cutters 21, 22 and 23 gradually increase, the cutting part 2 forms a stepped reamer to realize step-by-step reaming machining, avoid the cutting edge 20 of the cutting part 2 from contacting the heterogeneous laminated structure at the same time, reduce the cutting force in the manual hole machining process, and help to improve the hole machining efficiency of the manual hole machining. Since the machining amount and the tool main offset angle of the second reamer 22 are relatively large, the machining amount and the tool main offset angle of the cutting part 2 all have the characteristics of small in the first section, large in the middle section and small in the tail section, so as to reasonably adjust the single-step tool machining amount of the reaming tool and ensure the hole machining efficiency of the manual hole machining. Since the machining amount of the first section (the first reamer 21) is small, a relatively small tool main offset angle can reduce the cutting force at the beginning of cutting, so that the reaming tool smoothly enters the preformed hole of the heterogeneous laminated structure in the initial stage of cutting, and the stability of the manual hole machining process is improved. The machining amount and the tool main offset angle of the middle section (the second reamer 22) are relatively large, so as to increase the machining amount of the single process of the cutting part 2 and improve the hole machining efficiency of the manual hole machining. The machining amount and the tool main offset angle of the tail section (the third reamer 23) are the same as those of the first section, so that the machining amount and the tool main offset angle of the tail section are relatively low, the cutting force of the third reamer 23 is reduced, the instantaneous feed amount mutation of the interface of the heterogeneous laminated structure in the manual hole machining process is weakened, and the hole machining quality is improved.

[0035] As Figure 1 and Figure 2As shown, the shank 1 is provided with at least two cutting planes 11 in the circumferential direction, and the cutting planes 11 extend to the end of the shank 1 away from the cutting part 2. By providing the cutting planes 11, the clamping tool such as an air drill can be conveniently clamped to the hole expanding tool, and the clamping efficiency of the hole expanding tool is improved. In the embodiment, the shank 1 is provided with three cutting planes 11 in the circumferential direction at equal intervals, so that the shank 1 forms a three-flat-tail structure, the contact area between the chuck of the air drill and the shank 1 is increased, the shank 1 is prevented from rotating relative to the air drill during drilling, the stability of the hole expanding tool is improved, and the output power of the air drill can be efficiently output.

[0036] In the embodiment, the machining amount of the first hole expanding reamer 21 is 0.2mm-0.4mm, the machining amount of the second hole expanding reamer 22 is 0.4mm-0.6mm, and the machining amount of the third hole expanding reamer 23 is 0.2mm-0.4mm. The tool main offset angle of the first hole expanding reamer 21 is 45°-60°, the tool main offset angle of the second hole expanding reamer 22 is 80°-90°, and the tool main offset angle of the third hole expanding reamer 23 is 45°-60°. The machining amount and the tool main offset angle of the first hole expanding reamer 21 and the third hole expanding reamer 23 are the same, so that the cutting edges 20 of the first hole expanding reamer 21 and the third hole expanding reamer 23 have the same structure. The machining amount and the tool main offset angle of the second hole expanding reamer 22 are relatively high, so that the cutting amount of the second hole expanding reamer 22 is increased, and the machining amount of a single process is ensured. Since the cutting edge 20 of the first hole expanding reamer 21 can be in close contact with the heterogeneous laminated structure after being drilled into the prefabricated hole of the heterogeneous laminated structure, the cutting operation of the second hole expanding reamer 22 is supported well.

[0037] In the embodiment, the rake angle of the cutting edges 20 of the first hole expanding reamer 21, the second hole expanding reamer 22 and the third hole expanding reamer 23 is 8°-12°, the relief angle of the cutting edges 20 is 12°-25°, and the circumferential blade relief surface width of the cutting edges 20 is 1.8mm-2.0mm. By the above arrangement, the cutting edges 20 of the three hole expanding reamers have relatively large rake angles, so that the sharpness of the cutting edges 20 is increased, the cutting efficiency is improved, and the drilling efficiency of the manual drilling is improved.

[0038] As Figure 1 and Figure 2As shown, the first expanding reamer 21, the second expanding reamer 22 and the third expanding reamer 23 are all inverted taper expanding reamers, the taper of the first expanding reamer 21 and the second expanding reamer 22 is 0.01-0.05, and the taper of the third expanding reamer 23 is 0.01-0.02. Through the above setting, the three expanding reamers are all provided with taper, so as to reduce the friction between the expanding reamer and the heterogeneous laminated structure, and effectively reduce the temperature rise in the manual hole making process.

[0039] Further, the cutting part 2 further comprises a guide column 24, the guide column 24 is integrally connected to the end of the first expanding reamer 21 away from the second expanding reamer 22, and the diameter of the guide column 24 is smaller than that of the first expanding reamer 21. Through the setting of the guide column 24, the hole cutter is quickly guided into the preformed hole of the heterogeneous laminated structure, and the hole making efficiency of the manual hole making is improved. At the same time, the contact between the guide column 24 and the heterogeneous laminated structure provides stable guidance and support for the manual hole making process, reduces the vibration or shaking of the hole cutter, and improves the quality and efficiency of the manual hole making.

[0040] As shown in Figure 1 and Figure 2 , the cutting part 2 is provided with a plurality of chip removal grooves 3 along the circumference, and the chip removal grooves 3 extend from the end of the third expanding reamer 23 away from the second expanding reamer 22 to the end of the guide column 24 away from the first expanding reamer 21. Specifically, the helix angle of the chip removal groove 3 is 0°-8°, and the rake angle of the chip removal groove 3 is 10°-15°. The maximum diameter of the cutting part 2 (i.e. the diameter of the third expanding reamer 23) is D3, and the groove depth of the chip removal groove 3 is 0.45D3-0.65D3. Through the setting of the chip removal groove 3, the chips generated in the cutting process are discharged from the heterogeneous laminated structure along the chip removal groove 3, so as to ensure the smooth progress of the manual hole making. By setting the chip removal groove 3 on the guide column 24, part of the chips can be discharged from the end of the chip removal groove 3 located at the third expanding reamer 23, and the other part of the chips can be discharged from the end of the chip removal groove 3 located at the guide column 24, so as to improve the chip removal efficiency of the chip removal groove 3 and avoid the problem that the chips are blocked in the chip removal groove 3 and rub against the heterogeneous laminated structure to cause excessive temperature rise.

[0041] Further, the groove surface of the chip removal groove 3 is a polished surface, and the roughness of the polished surface is not greater than 0.4μm. After the groove surface of the chip removal groove 3 is polished, the groove surface of the chip removal groove 3 is smoother, which not only facilitates the quick discharge of the chips, but also reduces the friction between the chip removal groove 3 and the chips, and effectively suppresses the temperature rise generated in the chip removal process.

[0042] As shown in Figures 1 to 3As shown, the shank 1 and the first reaming cutter 21, the second reaming cutter 22, the third reaming cutter 23 and the guide column 24 of the cutting part 2 are integrally formed, facilitating the machining and manufacturing of the reaming tool and ensuring the structural strength and stability of the reaming tool. The first reaming cutter 21, the second reaming cutter 22 and the third reaming cutter 23 each have four cutting edges 20 symmetrically arranged along the axial direction of the cutting part 2, and each adjacent cutting edges 20 has a chip groove 3.

[0043] Further, as shown in Figure 3 , the initial cutting position of the cutting edge 20 of the first reaming cutter 21, the second reaming cutter 22 and the third reaming cutter 23 is provided with a blade structure 201. Specifically, the initial cutting position of the cutting edge 20 is the position of each cutting edge 20 for initial reaming machining of the preformed hole. The blade structure 201 is formed by chamfering the initial cutting position of the cutting edge 20, and the width h1 of the blade structure 201 is 0.18mm-0.22mm, so as to remove the machining burr of the cutting edge 20 at the initial cutting position and avoid scratching the inner surface of the preformed hole, which is beneficial to improve the machining quality of the manual drilling.

[0044] It should be noted that, as shown in Figure 2 and Figure 3 , the first reaming cutter 21 and the second reaming cutter 22, and the second reaming cutter 22 and the third reaming cutter 23 are each provided with a tool withdrawal groove 25. The tool withdrawal groove 25 is provided with an extension 251 on one side of the initial cutting position of the cutting edge 20, and the width h2 of the extension 251 is 0.1mm-0.25mm. By providing the extension 251, the chip space of the reaming tool is increased.

[0045] The above embodiments only illustrate the basic principles and characteristics of the present application, and the present application is not limited by the above embodiments. Without departing from the spirit and scope of the present application, various changes and modifications can be made, and these changes and modifications all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A reaming tool, characterized in that: The invention comprises a connected tool handle (1) and a cutting portion (2), wherein the cutting portion (2) comprises a first reamer (21), a second reamer (22) and a third reamer (23) connected in a stepped structure, and the third reamer (23) is connected to the tool handle (1); The diameters of the first reamer (21), the second reamer (22) and the third reamer (23) gradually increase, the processing volume of the second reamer (22) is greater than the processing volume of the first reamer (21) and the third reamer (23), and the tool main deflection angle of the second reamer (22) is greater than the tool main deflection angle of the first reamer (21) and the third reamer (23).

2. The reaming tool according to claim 1, characterized in that The processing amount of the first reamer (21) is 0.2mm-0.4mm, the processing amount of the second reamer (22) is 0.4mm-0.6mm, and the processing amount of the third reamer (23) is 0.2mm-0.4mm; The tool main deflection angle of the first reamer (21) is 45° to 60°, the tool main deflection angle of the second reamer (22) is 80° to 90°, and the tool main deflection angle of the third reamer (23) is 45° to 60°.

3. The reaming tool according to claim 1, characterized in that The front angle of the cutting edge (20) of the first reamer (21), the second reamer (22) and the third reamer (23) is 8° to 12°, the back angle of the cutting edge (20) is 12° to 25°, and the circumferential edge back width of the cutting edge (20) is 1.8mm to 2.0mm.

4. The reaming tool according to claim 1, characterized in that The first reamer (21), the second reamer (22) and the third reamer (23) are all inverted cone reamers. The taper of the first reamer (21) and the second reamer (22) is 0.01 to 0.05, and the taper of the third reamer (23) is 0.01 to 0.

02.

5. The reaming tool according to claim 1, characterized in that The initial cutting positions of the cutting edges (20) of the first reamer (21), the second reamer (22) and the third reamer (23) are all provided with a margin structure (201).

6. The reaming tool according to any one of claims 1 to 5, characterized in that: The cutting portion (2) further comprises a guide column (24), and one end of the first reamer (21) away from the second reamer (22) is integrally connected to the guide column (24), and the diameter of the guide column (24) is smaller than the diameter of the first reamer (21).

7. The reaming tool according to claim 6, characterized in that The cutting portion (2) is provided with a plurality of chip removal grooves (3) along the circumferential direction, and the chip removal grooves (3) extend from an end of the third reamer (23) away from the second reamer (22) to an end of the guide column (24) away from the first reamer (21).

8. The reaming tool according to claim 7, characterized in that The helix angle of the chip groove (3) is 0° to 8°, and the flute rake angle of the chip groove (3) is 10° to 15°; the maximum diameter of the cutting portion (2) is D3, and the flute depth of the chip groove (3) is 0.45D3 to 0.65D3.

9. The reaming tool according to claim 7, characterized in that The groove surface of the chip removal groove (3) is a polished surface, and the roughness of the polished surface is not greater than 0.4 μm.

10. The reaming tool according to any one of claims 1 to 5, characterized in that: The knife handle (1) is provided with at least two cutting planes (11) along the circumferential direction, and the cutting planes (11) extend to an end of the knife handle (1) away from the cutting portion (2).

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