CN102380627B - Variable- relief angle wide hole chamfering tool - Google Patents

Abstract

The invention discloses a variable-relief angle wide hole chamfering tool. The variable-relief angle wide hole chamfering tool comprises a handle part and a cutting part, wherein the cutting part is provided with a chamfered tooth and a chip pocket, wherein the chamfered tooth is provided a first back tool face, a second back tool face and a third back tool face of which the relief angles are increased in turn; and the widths of each back tool faces are gradually decreased from the periphery to the centre of the cutting part. The variable- relief angle wide hole chamfering tool has the advantages of simple structure, convenience of manufacturing, high machining efficiency, high machined surface finish degree, and long service life.

Description

Variable rear angle wide hole chamfering knife

technical field

The invention relates to metal cutting tools, in particular to chamfering cutters with variable relief angles and wide holes.

Background technique

In the field of mechanical processing, the existence of sharp corners not only causes certain difficulties in the assembly of parts, but also easily causes injury to the operator. Therefore, chamfering is generally required for sharp corners. The well-known hole chamfering tools are twist drills and center drills. Since the twist drills and center drills are mainly used for drilling, their grooves are not specially designed for the chamfering process, and there is a negative radial front with a large absolute value. Angle, cutting is not sharp and other problems, so there are often burrs, vibration lines on the chamfered surface, chamfering is not smooth and so on.

The closer the existing tool is to the center of the tool, the smaller the radius of gyration and the lower the cutting speed; the farther away from the center of the tool, the larger the radius of gyration and the higher the cutting speed. According to the principle of metal cutting, the higher the cutting speed, the more severe the wear and the more Chipping is easy to occur; at the same time, in the known technology, the rear angle width of general metal cutting tools is uniform, but for chamfering knives, the cutting speed of each point on the chamfering teeth is not equal , if a structure with equal relief angle width is adopted, while ensuring the strength of the chamfer teeth at the outermost edge of the tool, the relief angle width at the center of the tool is too wide, the hysteresis is not enough, and there is a part higher than the cutting edge, resulting in the tool not being able to Carry out normal cutting; when the strength of the chamfering teeth at the center of the tool is guaranteed, the strength at the outermost edge of the tool is obviously insufficient, and the edge is prone to chipping during cutting.

In addition, the Chinese patent document with the publication number CN101780548A discloses a chamfering knife, which has a cylindrical tool body. The rear end of the tool body forms a shank, and the front end forms a cutting part. The discharge groove with the drill tip extending backward, one side of the discharge groove forms the rake face, the intersection line between the rake face and the outer surface of the tapered drill tip forms the cutting edge, and the tool body is made of tungsten carbide. The advantage of this kind of chamfering knife is that the tool has very good wear resistance and heat resistance, the machined surface is smooth, and the precision is high, but there are still the following two defects: 1. There is only one discharge groove and one rake face And one cutting edge, in the chamfering process, since there is only one cutting edge, the force on the tool is unbalanced during the cutting process, and it is prone to deflection, resulting in poor surface finish, and in severe cases, it may even cause the tool to break; 2. There is only one cutting edge, the feed per tooth is limited, and the chamfering efficiency is also limited.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a chamfering knife with variable relief angle and wide hole, which is simple in structure, easy to manufacture, high in processing efficiency, good in processing surface finish, and long in service life.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A wide hole chamfering cutter with variable relief angle, comprising a shank and a cutting portion, the cutting portion is provided with chamfering teeth and chip pockets, and the chamfering teeth are provided with first relief cutters whose relief angle values increase sequentially Surface, second flank and third flank, and the width of each flank gradually decreases from the outer circumference of the cutting part to the center.

The range of the relief angle β ₁ of the first flank is 2°≤β ₁ ≤10°; the range of the relief angle β ₂ of the second flank is 20°≤β ₂ ≤30°; the The range of the relief angle β ₃ of the third flank is 35°≤β ₃ ≤60°.

Near the center of the cutting part, the range of the relief width B ₃₁ of the first relief face is 0.01mm≤B ₃₁ ≤0.1mm; the range of the relief width B ₄₁ of the second relief face is 0.01mm≤B ₄₁ ≤0.2mm; the range of the relief angle width B ₅₁ of the third flank is 0.01mm≤B ₅₁ ≤1mm.

Near the outer periphery of the cutting part, the relief angle width B ₃₂ of the first relief surface, 0.2mm≤B ₃₂ ≤0.3mm; the relief angle width B ₄₂ of the second relief surface, 2.5mm≤B ₄₂ ≤3.5mm; the clearance angle width B ₅₂ of the third flank surface is 4mm≤B ₅₂ ≤8mm.

The chip flute is a straight groove structure, and the chip flute is composed of a first straight line, an arc, and a second straight line in the radial section, and the first straight line and the second straight line are respectively in phase with the arc. cut.

The range of the distance D from the first straight line to the center of the cutting part is -0.05mm≤D≤+0.05mm. the

The included angle between the first straight line and the second straight line is the groove angle α, 90°<α<130°.

There are more than two chamfering teeth, and the two or more chamfering teeth are evenly distributed along the circumference of the cutting part.

Compared with the prior art, the present invention has the advantages of:

In the variable relief angle wide hole chamfering cutter of the present invention, the chamfering teeth are provided with a first flank face, a second flank face and a third flank face whose relief angle values increase sequentially, and the width of each flank face is from The outer circumference of the cutting part gradually decreases toward the center. At the center of the cutting part, the relief angle width takes a small value, taking into account the tool strength and hysteresis. When it is close to the cutting part periphery, the relief angle width takes a large value to improve the chamfering as much as possible. The strength of the tooth increases the service life of the tool. The wide hole chamfering cutter with variable back angle adopts a straight groove structure. Compared with the spiral blade cutter, the present invention has simple structure, easy manufacture, low production cost and easier guarantee of chamfering angle. The wide-hole chamfering knife with variable back angle of the present invention is provided with more than two chamfering teeth, and the radial cutting forces acting on the chamfering teeth during the chamfering process will cancel each other, suppressing the vibration generated during the chamfering process, It improves the quality of the machined surface, avoids edge chipping, and prolongs the tool life. At the same time, due to the structure of more than two chamfering teeth, the cutting efficiency is twice that of a single-edged tool under the same feed rate per tooth. . the

Description of drawings

Fig. 1 is a front view of an embodiment of the hole chamfering knife of the present invention.

Fig. 2 is a schematic diagram of the rear angle structure of the embodiment of the hole chamfering knife of the present invention.

Fig. 3 is a schematic diagram of the rear angle width structure of the embodiment of the hole chamfering knife of the present invention.

Fig. 4 is a radial cross-sectional view of the embodiment of the hole chamfering tool of the present invention at the chip pocket.

Each label in the figure means:

1. Shank; 2. Cutting part; 3. First flank; 4. Second flank; 5. Third flank; 21. Chamfering tooth; 22. Chip pocket; 221. First Straight line; 222, second straight line; 223, circular arc.

Detailed ways

Figures 1 to 4 show an embodiment of a wide hole chamfering cutter with variable relief angle of the present invention, the hole chamfering cutter includes a shank 1 and a cutting part 2, and the cutting part 2 is provided with a chamfering tooth 21 and a chip container Groove 22, chamfering teeth 21 are provided with the first flank 3, the second flank 4 and the third flank 5 whose relief angles increase in sequence, and the width of each flank is from the outer circumference of the cutting part 2 The center gradually decreases, and near the center of the cutting part 2, the relief angle width takes a small value, which can take into account the strength of the tool and the hysteresis. strength, thereby increasing tool life.

In this embodiment, the range of the relief angle _β1 of the first flank 3 is 2° _≤β1≤10 °; the range of the relief angle _β2 of the second flank 4 is 20° _≤β2≤30 ° ; The range of the relief angle β ₃ of the third flank 5 is 35°≤β ₃ ≤60°. Near the center of the cutting part 2, the range of the relief width B ₃₁ of the first flank 3 is 0.01mm≤B ₃₁ ≤0.1mm; the range of the relief width B ₄₁ of the second flank 4 is 0.01mm≤ B ₄₁ ≤0.2mm; the range of the clearance width B ₅₁ of the third flank 5 is 0.01mm≤B ₅₁ ≤1mm. Near the outer periphery of the cutting part 2, the relief angle width B ₃₂ of the first relief surface 3, 0.2mm≤B ₃₂ ≤0.3mm; the relief angle width B ₄₂ of the second relief surface 4, 2.5mm≤B ₄₂ ≤3.5 mm; the relief angle width B ₅₂ of the third flank 5 , 4mm≤B ₅₂ ≤8mm. In this embodiment, β ₁ =8°, β ₂ =28°, β ₃ =50°, B ₃₁ =0.03mm, B ₄₁ =0.1mm, B ₅₁ =0.5mm, B ₃₂ =0.3mm, B ₄₂ = 3mm, B ₅₂ =7mm.

In this embodiment, the chip flute 22 is a straight groove structure. Compared with the spiral cutting tool, the structure of the present invention is simple, easy to manufacture, low in production cost, and the chamfer angle is easier to ensure. It is composed of a first straight line 221 , an arc 223 and a second straight line 222 sequentially connected, and the first straight line 221 and the second straight line 222 are respectively tangent to the arc 223 . The range of the distance D from the first straight line 221 to the center of the cutting part 2 is -0.05mm≤D≤+0.05mm, the angle between the first straight line 221 and the second straight line 222 is the groove angle α, 90°<α< 130°.

In this embodiment, there are more than two chamfering teeth 21, and more than two chamfering teeth 21 are evenly distributed along the circumference of the cutting part 2. In this embodiment, two chamfering teeth 21 are provided. During the chamfering process, the chamfering teeth 21 act on The radial cutting forces on the chamfering teeth 21 will cancel each other, suppress the vibration generated during the chamfering process, improve the quality of the machined surface, avoid chipping, and prolong the tool life. With the structure of the teeth 21, the cutting efficiency is twice that of a single-edged tool under the same feed rate per tooth.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent implementation of equivalent changes example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention. the

Claims (4)

1. one kind becomes relief angle wide hole chamfering tool, comprise shank (1) and cutting portion (2), described cutting portion (2) is provided with chamfered teeth (21) and chip pocket (22), it is characterized in that: described chamfered teeth (21) is provided with major first flank (3), the second rear knife face (4) and the 3rd rear knife face (5) that the relief angle value increases successively, and the outer circumferentially center of the width self-cutting section (2) of knife face reduces the relief angle β of described major first flank (3) gradually after each ₁Scope be 2 °≤β ₁≤ 10 °; The relief angle β of the described second rear knife face (4) ₂Scope be 20 °≤β ₂≤ 30 °; The relief angle β of the described the 3rd rear knife face (5) ₃Scope be 35 °≤β ₃≤ 60 °, at close described cutting portion (2) center, the rear angular width B of described major first flank (3) ₃₁Scope be 0.01mm≤B ₃₁≤ 0.1mm; The rear angular width B of the described second rear knife face (4) ₄₁Scope be 0.01mm≤B ₄₁≤ 0.2mm; The rear angular width B of the described the 3rd rear knife face (5) ₅₁Scope be 0.01mm≤B ₅₁≤ 1mm is at close described cutting portion (2) periphery, the rear angular width B of described major first flank (3) ₃₂, 0.2mm≤B ₃₂≤ 0.3mm; The rear angular width B of the described second rear knife face (4) ₄₂, 2.5mm≤B ₄₂≤ 3.5mm; The rear angular width B of the described the 3rd rear knife face (5) ₅₂, 4mm≤B ₅₂≤ 8mm, described chamfered teeth (21) is provided with more than two, and described two above chamfered teeths (21) circumferentially evenly distribute along cutting portion (2).

2. change relief angle wide hole chamfering tool according to claim 1, it is characterized in that: described chip pocket (22) is straight groove structure, described chip pocket (22) is connected and composed successively by the first straight line (221), circular arc (223) and the second straight line (222) on radial section, and the first straight line (221) and the second straight line (222) are tangent with circular arc (223) respectively.

3. change relief angle wide hole chamfering tool according to claim 2 is characterized in that: described the first straight line (221) to the scope of the distance B at cutting portion (2) center for-0.05mm≤D≤+ 0.05mm.

4. change relief angle wide hole chamfering tool according to claim 3, it is characterized in that: the angle of described the first straight line (221) and the second straight line (222) is grooved angle α, 90 °＜α＜130 °.

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