Tooth cutting tool suitable for machining involute inner helical teeth with different helical angles

Abstract

The invention discloses a tooth cutting tool suitable for machining involute inner helical teeth with different helical angles, cutter teeth are distributed on the tooth cutting tool along the circumference, the structure of each cutter tooth comprises a cutting edge, a rear cutter surface and a front cutter surface, and the cutting edge comprises a left side edge, a right side edge and a top edge; wherein the left side blade and the right side blade are involute profiles on the left side and the right side on the middle section of a drum-shaped outer straight gear meshed with an inner helical tooth part; the top edge is an arc which is in the same plane with the left edge and the right edge and is tangent to the left edge and the right edge respectively; the flank is formed by lofting the cutting edge and a series of flank construction lines; the rear tool face construction line is formed by connecting involute profiles on the left side and the right side of the middle section of the drum-shaped outer straight gear with the diameters gradually reduced and arcs tangent to the involute profiles. The front tool face is a free-form surface which is formed by fitting a cutting edge and a series of rear tool face construction lines and can form a cutting front angle. The tooth cutting cutter can be used for machining workpieces with different helical angles, and the production cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to a tool for machining involute internal bevel gears, in particular to a tooth-scratching tool suitable for machining involute internal bevel gears with different helical angles. Background Art

[0002] Gear cutting tools are a hot topic in the current gear processing related fields. Gear cutting tools designed and manufactured according to the current gear cutting tool design theory can only process one workpiece and are not universal, which limits the large-scale promotion of gear cutting technology. Summary of the invention

[0003] The purpose of the present invention is to provide a tooth cutting tool suitable for processing involute internal bevel teeth with different helix angles, in order to solve the problem that current tooth cutting tools are not universal, so as to achieve the purpose of processing involute internal bevel teeth with different helix angles with one tool.

[0004] The technical solution adopted to achieve the purpose of the present invention is:

[0005] A tooth-cutting tool suitable for machining involute internal helical teeth with different helix angles, wherein teeth are distributed along the circumference of the tooth-cutting tool, and the teeth include a cutting edge, a flank face, and a rake face.

[0006] The cutting edge comprises a left edge, a right edge and a top edge, wherein:

[0007] The left and right edges are involute profiles on the left and right sides of the middle section of the drum-shaped external spur gear meshing with the internal helical gear part; the top edge is an arc in the same plane as the left and right edges and tangent to the left and right edges respectively;

[0008] The flank surface is formed by lofting a cutting edge and a series of flank surface construction lines; the flank surface construction lines are formed by connecting the involute profiles on the left and right sides of the middle section of the drum-shaped external spur gear with a successively reduced diameter and the circular arcs tangent thereto;

[0009] The rake face is a free-form surface formed by fitting the cutting edge and a series of flank face construction lines and capable of forming a cutting front angle.

[0010] In the above technical solution, the front angle is -5 to 20 degrees.

[0011] In the above technical solution, the left edge and the right edge are constructed as follows:

[0012] A drum-shaped external spur gear is constructed to mesh with an internal helical gear ring without backlash. A middle section of the drum-shaped external spur gear is taken, and the middle section intersects with the cutter teeth to form left and right involute profiles, and the two involute profiles serve as the left and right cutting edges of the cutter, respectively.

[0013] In the above technical solution, the top blade is constructed by the following method:

[0014] On the plane where the middle section of the drum-type external spur gear is located, a section of circular arc tangent to the left edge and the right edge is constructed to form a top edge.

[0015] In the above technical solution, the cutting edge is constructed by the following method: the left edge, the right edge and the top edge are connected to form the cutting edge.

[0016] In the above technical solution, the back cutting surface is constructed by the following method:

[0017] The diameter of the drum-shaped external spur gear meshing with the internal helical gear part is reduced, the involute profiles on the left and right sides of the middle section are intercepted, and a section of arc tangent to the involute profiles on both sides is constructed on the same plane of the involute profiles on both sides, and the involute profiles on both sides and the arc are connected to form a back tool face construction line; in this way, the diameter of the drum-shaped external spur gear is reduced in sequence to form back tool face construction lines arranged in sequence along the axial direction of the tool, and the cutting edge and all the back tool face construction lines are subjected to surface fitting to form the back tool face.

[0018] In the above technical solution, the front cutting surface is constructed by the following method:

[0019] The cutting edge is discretized into a group of edge points, and a rake face construction line reflecting the rake angle is constructed at each edge point according to the cutting principle. The rake face is formed by constructing a curved surface using all the rake face construction lines.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The involute internal helical tooth cutting tool of the present invention is applicable to different helical angles. By setting different axial intersection angles between the tool and the workpiece, internal helical tooth parts with different helical angles within a certain helical angle range can be processed;

[0022] 2. The front cutting edge of the tooth cutting tool of the present invention has a front angle, which can significantly improve the cutting conditions and extend the tool life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Shown is a structural diagram of the tooth-scraping cutter of the present invention;

[0024] Figure 2 Shown is a schematic diagram of the cutting edge composition;

[0025] Figure 3 Shown are schematic diagrams of the left and right blades;

[0026] Figure 4 Shown is a schematic diagram of the back cutting edge;

[0027] Figure 5 Shown is a schematic diagram of the front cutting edge;

[0028] In the figure: 1-tooth, 2-cutting edge, 3-flank face, 4-rake face, 5-left edge, 6-right edge, 7-top edge, 8-flank face construction line, 9-front angle, 10-rake face construction line, 11-base surface, 12-midsection, 13-involute profile, 14-arc;

[0029] A-tooth cutting tool, B-drum type external spur gear, C-internal helical gear ring. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] like Figure 1-Figure 5 As shown in the figure, a tooth cutting tool A suitable for machining involute internal helical teeth with different helical angles of the present invention has a plurality of teeth 1 evenly distributed on the circumference. The teeth 1 include a cutting edge 2, a back face 3 and a front face 4. Figure 2 As shown, the cutting edge 2 includes a left edge 5 , a right edge 6 and a top edge 7 .

[0032] The left edge 5 and the right edge 6 can be constructed as follows:

[0033] The drum-type external spur gear B is constructed to mesh with the internal helical gear ring C without backlash, such as Figure 3 As shown, the middle section 12 of the drum-shaped external spur gear B is taken, and the middle section 12 intersects with the cutter tooth 1 to form left and right involute profiles 13, and the two involute profiles 13 serve as the left edge 5 and the right edge 6 of the cutter respectively.

[0034] like Figure 2 As shown, the top blade 7 can be constructed as follows:

[0035] An arc tangent to the left edge 5 and the right edge 6 is constructed on the plane where the left edge 5 and the right edge 6 are located, and the arc is the top edge 7.

[0036] like Figure 2 As shown, the cutting edge 2 can be constructed as follows:

[0037] The cutting edge 2 is formed by connecting the left edge 5 , the right edge 6 and the top edge 7 .

[0038] The flank face 3 is formed by lofting the cutting edge 2 and a series of flank face construction lines 8, and can be constructed as follows:

[0039] exist Figure 4 In the process, place cutting edge 2 on the first layer and the back face construction lines 8 and S C2 , S C3 , S C4 , SC5 ...are arranged in sequence along the axial direction of the tool, and the arranged curves are fitted into a surface, and the resulting surface is the back tool surface 3.

[0040] The flank construction line 8 can be constructed as follows:

[0041] According to the cutting edge 2 construction method, the diameter of the drum-shaped external spur gear B is reduced, the involute profiles 13 on the left and right sides of the middle section 12 of the drum-shaped external spur gear B are taken, and arcs 14 tangent to the involute profiles 13 on both sides are constructed on the same plane, and the involute profiles 13 on both sides and the arcs 14 are connected to form a back cutting surface construction line 8, such as Figure 4 shown.

[0042] According to the construction method of the flank face construction line 8, the diameter of the drum-shaped external spur gear B meshing with the internal helical gear part is reduced in sequence to construct a series of flank face construction lines S C2 , S C3 , S C4 , S C5 ……,like Figure 4 shown.

[0043] like Figure 5 As shown, the front cutting surface 4 can be constructed as follows:

[0044] The cutting edge 2 is discretized into a number of edge points, and a ray of a rake angle 9 is made at each edge point as a rake face construction line 10. The angle between the rake face construction line 10 and the base surface 11 is the rake angle 9, and a curved surface is constructed using these rake face construction lines 10, and the curved surface is the rake face 4.

[0045] The above description is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A tooth cutting tool suitable for machining involute internal helical teeth with different helix angles, wherein teeth (1) are distributed along the circumference of the tooth cutting tool, and the teeth (1) include a cutting edge (2), a flank face (3) and a rake face (4), and is characterized in that: The cutting edge (2) comprises a left edge (5), a right edge (6) and a top edge (7), wherein: The left edge (5) and the right edge (6) are involute profiles (13) on the left and right sides of a middle section (12) of a drum-shaped external spur gear (B) meshing with an internal helical gear part; the top edge (7) is an arc in the same plane as the left edge (5) and the right edge (6), and is tangent to the left edge (5) and the right edge (6) respectively; The flank face (3) is formed by lofting a cutting edge (2) and a series of flank face construction lines (8); the flank face construction lines (8) are formed by connecting involute profiles (13) on the left and right sides of a middle section (12) of a drum-shaped external spur gear (B) with a successively decreasing diameter and circular arcs (14) tangent thereto; The front cutting edge (4) is a free-form surface with a front angle (9) and a structure with the cutting edge (2) as a boundary.

2. The tooth-scraping tool according to claim 1, characterized in that: The front angle (9) is -5 to 20 degrees.

3. The tooth-scraping tool according to claim 1, characterized in that: The left edge (5) and the right edge (6) are constructed by the following method: A drum-shaped external spur gear (B) is constructed to mesh with an internal helical gear ring (C) without backlash. A middle section (12) of the drum-shaped external spur gear (B) is taken. The middle section (12) intersects with a cutter tooth (1) to form left and right involute profiles (13). The two involute profiles (13) serve as a left edge (5) and a right edge (6) of a cutter, respectively.

4. The tooth-scraping tool according to claim 3, characterized in that: The top blade (7) is constructed by the following method: On the plane where the middle section (12) of the drum-shaped external spur gear (B) is located, a circular arc tangent to the left edge (5) and the right edge (6) is constructed to form a top edge (7).

5. The tooth-scraping tool according to claim 4, characterized in that: The cutting edge (2) is constructed by the following method: The left edge (5), the right edge (6) and the top edge (7) are connected together to form a cutting edge (2).

6. The tooth-scraping tool according to claim 5, characterized in that: The back cutting surface (3) is constructed by the following method: The diameter of a drum-shaped external spur gear (B) meshing with an internal helical gear part is reduced, the involute profiles (13) on the left and right sides of the middle section (12) are intercepted, and a section of circular arc (14) tangent to the involute profiles (13) on the two sides is constructed on the same plane of the involute profiles (13) on the two sides, and the involute profiles (13) on the two sides and the circular arc (14) are connected to form a back tool face construction line (8); in this way, the diameter of the drum-shaped external spur gear (B) is reduced in sequence to form back tool face construction lines (8) arranged in sequence along the axial direction of the tool, and the cutting edge (2) and all the back tool face construction lines (8) are subjected to surface fitting to form the back tool face (3).

7. The tooth-scraping tool according to claim 6, characterized in that: The front cutting surface (4) is constructed by the following method: The cutting edge (2) is discretized into a group of edge points, and a rake face construction line (10) reflecting a rake angle (9) is constructed at each edge point according to the cutting principle, and a curved surface is constructed using all rake face construction lines (10) to form the rake face (4).

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