Circular-arc edge broach blade

Abstract

The utility model discloses a kind of circular-arc blade of broach, including blade main body, the blade main body includes main cutting edge, positioning groove, locating surface and tool tooth, the main cutting edge is the circular-arc blade being set in tool tooth top, the tool tooth is evenly arranged along blade main body long side side, and both sides tool tooth is set with blade central axis as axis symmetry, axially extending chip flute is equipped between adjacent tool tooth, the locating surface one side is equipped with main cutting edge rake face, the main cutting edge rake face extends to tool tooth, and main cutting edge rake face and locating surface transition connection;The positioning groove is symmetrically set in blade main body short side side.The utility model's cutting edge is high in strength, not easy to wear, and the cutting life of blade is high, improves the cutting stability and processing efficiency of blade.

Description

Technical Field

[0001] This utility model belongs to the field of cutting blade technology, and in particular, relates to a broaching blade with a circular arc cutting edge. Background Technology

[0002] As a high-precision, high-efficiency cutting tool, the broach possesses excellent toughness and cutting performance, making it suitable for broaching general metal materials. Broaches are widely used in automotive manufacturing (cylinder block bores, gear splines), aerospace, machine tool manufacturing, and other fields. Their high efficiency and precision meet the machining requirements of complex parts in mass production. Broach inserts employ a typical "progressive multi-tooth" design, where the cutting amount (tooth rise) of each tooth gradually increases, ultimately ensuring dimensional accuracy through a finishing tooth. This design is suitable for machining complex surfaces such as internal holes, splines, and planes. The chip removal groove design must balance chip space and insert strength, commonly using U-shaped, arc-shaped, or spiral grooves to ensure smooth chip removal.

[0003] Existing broaching inserts are prone to chip clogging of the chip evacuation channels when broaching deep holes or complex surfaces, leading to tool jamming or tooth breakage. For example, ribbon-like chips generated during aluminum alloy machining can become entangled in the broach teeth if not broken in time. Standard broach tooth profiles are difficult to meet customized needs (such as asymmetric splines or variable cross-section grooves), and the angular design of the teeth makes them extremely prone to wear during cutting, resulting in the need for regrinding or scrapping the entire broach, leading to high maintenance costs.

[0004] The existing patent CN105057778B discloses an integral cemented carbide internal and external chamfering broach, including a broach base (1), several cutting teeth A (2) and several cutting teeth B (3). The broach base (1) is rectangular. The cutting teeth A (2) and B (3) are respectively arranged on the upper and lower sides of the broach base (1). One end of the broach base (1) is provided with a clamping end (5). The cutting edges of the cutting teeth A (2) and B (3) are close to the clamping end (5). The beneficial effects of this invention are: the broach is used to process the internal and external chamfers of the sliding groove, which has the advantage of being able to form in one step, reducing the number of tools used, saving processing costs, and the tools have the advantages of sharp cutting edges, long service life, high tool rigidity, stable and reliable clamping, and low vibration during processing. The chamfers produced have high precision and good surface finish. However, the circular arc teeth in this patent are formed by pressing, and if the size is too small, there may be large deformation. Large deformation can easily lead to unstable cutting. Grinding is too costly and increases cutting resistance, which can easily lead to accelerated wear of the cutting tool. Utility Model Content

[0005] This invention primarily addresses the problem in existing broaching inserts where chips easily clog the chip evacuation grooves during deep hole or complex surface broaching, leading to tool jamming or tooth breakage. For example, ribbon-like chips generated during aluminum alloy machining, if not broken in time, can entangle the broach teeth. Standard broach tooth profiles are difficult to meet customized needs (such as asymmetrical splines or variable cross-section grooves), and the angular design of the teeth makes them extremely prone to wear during cutting, resulting in the need for regrinding or scrapping the entire broach, leading to high maintenance costs. This invention proposes a broach insert with a rounded cutting edge.

[0006] A circular arc cutting edge broach insert includes an insert body, which includes a main cutting edge, a positioning groove, a positioning surface, and cutting teeth. The main cutting edge is a circular arc edge set on the top of the cutting teeth. The cutting teeth are evenly distributed along the long side of the insert body, and the cutting teeth on both sides are symmetrically arranged about the central axis of the insert. Chip-breaking grooves extending axially are provided between adjacent cutting teeth. A rake face of the main cutting edge is provided on one side of the positioning surface. The rake face of the main cutting edge extends to the cutting teeth, and the rake face of the main cutting edge is transitionally connected to the positioning surface. The positioning groove is symmetrically arranged on the short side of the insert body.

[0007] Furthermore, the blade body is a rectangular parallelepiped structure, and a screw hole is provided at the geometric center of the blade body. The screw hole penetrates the positioning surface and is used to fix the blade body to the handle with a screw.

[0008] Furthermore, the chip-breaking groove is arranged along the length direction of the main cutting edge, and the chip-breaking grooves between adjacent main cutting edges are symmetrically distributed, with a groove depth of 0.5 to 2 mm.

[0009] Furthermore, the cross-section of the chip-dispersing groove is V-shaped or rectangular.

[0010] Furthermore, the blade body is also provided with marking points, which are raised or recessed structures on the positioning surface, and the marking points are used to indicate the installation direction.

[0011] Furthermore, the tooth profile angle of the main cutting edge is 60°, and the tooth tip radius of the main cutting edge located at the tooth tip is 0.1mm.

[0012] Furthermore, the width and height of the tooth tip arc are 0.4 mm and 0.1 mm, respectively.

[0013] Furthermore, the spacing between adjacent cutting teeth is 2 to 3 mm.

[0014] Furthermore, the blade body is made of cemented carbide, and the surface of the main cutting edge is coated with a coating thickness of 3 to 5 μm.

[0015] Furthermore, the rake face of the main cutting edge is an inclined plane that forms a preset acute angle with the plane containing the tooth tip of the main cutting edge, and is continuously distributed along the tool feed direction to optimize the chip removal path during cutting.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] 1. A tool body comprising a main cutting edge, a positioning groove, a positioning surface, and cutting teeth. The main cutting edge is an arc-shaped cutting edge located at the top of the cutting teeth. The cutting teeth are evenly distributed along the long side of the tool body, and the cutting teeth on both sides are symmetrical along the central axis of the tool. A rake face of the main cutting edge is provided on one side of the positioning surface, extending to the cutting teeth, and the rake face of the main cutting edge is transitionally connected to the positioning surface. The positioning groove is symmetrically located on the short side of the tool body. This invention increases the strength of the cutting edge and the service life of the broach by providing an arc-shaped cutting edge facing outwards from the tool.

[0018] 2. The present invention provides a chip-splitting groove extending axially between adjacent cutting teeth. The chip-splitting groove divides wide chips into narrow chips. Combined with the inclination angle of the rake face of the main cutting edge, it guides the chips to be discharged in an orderly manner, avoids chip accumulation and blockage, reduces cutting resistance, and improves cutting stability and machining efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is the front view of the present invention;

[0021] Figure 3 This is a side view of the present invention;

[0022] Figure 4 This is a top view of the present invention.

[0023] In the above figure, 1. main cutting edge; 2. positioning groove; 3. positioning surface; 4. chip groove; 5. rake face of main cutting edge; 6. marking point; 7. screw hole; 8. cutting tooth. Detailed Implementation

[0024] To clearly illustrate the technical features of this utility model, the following detailed description is provided through specific embodiments and in conjunction with the accompanying drawings.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0026] Furthermore, in the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] In this utility model, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] Example 1

[0030] like Figures 1 to 4As shown, a circular arc-shaped broach insert includes an insert body, which includes a main cutting edge 1, a positioning groove 2, a positioning surface 3, and cutting teeth 8. The main cutting edge 1 is a circular arc edge set on the top of the cutting teeth 8. The cutting teeth 8 are evenly arranged along the long side of the insert body, and the cutting teeth 8 on both sides are symmetrically arranged about the central axis of the insert. The central axis is an axis that passes through the center point of the insert and is parallel to the arrangement direction of the cutting teeth 8 on both sides. Chip-breaking grooves 4 extending axially are provided between adjacent cutting teeth 8. The positioning surface 3 has a main cutting edge rake face 5 on one side, which extends to the cutting teeth 8 and is transitionally connected to the positioning surface 3. The positioning groove 2 is symmetrically arranged on the short side of the insert body.

[0031] In this embodiment, the blade body is generally rectangular in shape and symmetrical about the central axis. A screw hole 7 is provided at the geometric center. The screw hole 7 passes through the entire blade body. The blade body can be firmly fixed to the handle with the help of screws, ensuring the reliability of blade installation.

[0032] like Figure 2 As shown, in this embodiment, the insert body is made of high-performance cemented carbide to ensure wear resistance and strength under high cutting forces. Multiple cutting teeth 8 are provided along the long side of the insert body, evenly distributed along the long side, with a total of 14 teeth 8. The teeth 8 on both sides are symmetrical along the central axis of the insert body, and the spacing between adjacent teeth 8 is 2.5mm. This ensures cutting efficiency while avoiding chip clogging caused by excessively dense teeth 8. The main cutting edge 1 is located at the top of the cutting teeth 8, and is an arc-shaped edge facing outwards from the insert body. Its tooth tip arc radius is 0.1mm, and the tooth tip arc width and height are 0.4mm and 0.1mm, respectively. The main cutting edge 1 is designed as an arc-shaped edge, which can effectively disperse cutting forces and reduce the generation of cutting heat. The rake face 5 of the main cutting edge is an inclined plane, forming a 15° acute angle with the plane where the tooth tip of the main cutting edge 1 is located. It is continuously distributed along the tool feed direction, optimizing the chip removal path during cutting and further improving the smoothness of the machining process.

[0033] The chip-breaking groove 4 extends along the length of the main cutting edge 1, has a V-shaped cross-section, a groove depth of 1mm, and is symmetrically distributed between adjacent main cutting edges 1, which enables the chips to break and be discharged smoothly, greatly improving the chip removal effect.

[0034] In practical applications, the broaching blade of this invention significantly improves the stability and precision of parts machining. At the same time, tool life is extended by more than three times, reducing production costs and increasing production efficiency.

[0035] Example 2

[0036] like Figures 1 to 4As shown, a circular arc-shaped broach insert includes an insert body, which includes a main cutting edge 1, a positioning groove 2, a positioning surface 3, and cutting teeth 8. The main cutting edge 1 is a circular arc edge set on the top of the cutting teeth 8. The cutting teeth 8 are evenly arranged along the long side of the insert body and are symmetrical about the central axis of the insert. Chip-breaking grooves 4 extending axially are provided between adjacent cutting teeth 8. A rake face 5 of the main cutting edge is provided on one side of the positioning surface 3. The rake face 5 of the main cutting edge extends to the cutting teeth 8 and is transitionally connected to the positioning surface 3. The positioning groove 2 is symmetrically arranged on the short side of the insert body.

[0037] In this embodiment, the main body of the cutting tool is made of cemented carbide with added special trace elements, which further improves its performance under high temperature and high pressure cutting conditions. The surface of the main cutting edge 1 is coated with a high-performance coating, namely TiAlN coating, which not only improves the wear resistance of the cutting tool, but also reduces the cutting force and the coefficient of friction between the tool and the workpiece.

[0038] In this embodiment, the tooth profile angle of the cutting teeth 8 is set to 60°. The cutting teeth 8 are evenly distributed along the long side of the blade body, and the cutting teeth 8 on both sides are strictly symmetrical about the central axis of the blade. The spacing between adjacent cutting teeth 8 on the same side is small, at 2.0 mm. The main cutting edge 1 located at the tooth tip 8 has a tooth tip arc radius of 0.1 mm, a tooth tip arc width of 0.4 mm, and a height of 0.1 mm. This precise tooth profile design can achieve high-precision machining of parts while ensuring the strength of the cutting edge. The blade body is also provided with marking points 6, which are raised structures set on the positioning surface 3 to clearly indicate the installation direction, ensuring that the blade can be accurately installed in complex aerospace manufacturing processes and avoiding machining errors caused by incorrect installation.

[0039] During machining, the spacing between adjacent cutting teeth 8 is 2mm, ensuring sufficient chip space and preventing chip accumulation from affecting machining accuracy. The chip divider 4 has a rectangular cross-section and a depth of 0.5mm, effectively dividing the chips into small segments for easy removal and suitable for precision machining.

[0040] Example 3

[0041] like Figures 1 to 4 As shown, a circular arc-shaped broach insert includes an insert body, which includes a main cutting edge 1, a positioning groove 2, a positioning surface 3, and cutting teeth 8. The main cutting edge 1 is a circular arc edge set on the top of the cutting teeth 8. The cutting teeth 8 are evenly arranged along the long side of the insert body and are symmetrical about the central axis of the insert. Chip-breaking grooves 4 extending axially are provided between adjacent cutting teeth 8. A rake face 5 of the main cutting edge is provided on one side of the positioning surface 3. The rake face 5 of the main cutting edge extends to the cutting teeth 8 and is transitionally connected to the positioning surface 3. The positioning groove 2 is symmetrically arranged on the short side of the insert body.

[0042] In this embodiment, the blade body is made of cemented carbide. Ten cutting teeth 8 are evenly distributed along the long side of the blade body, with symmetrical teeth 8 on both sides. The spacing between adjacent teeth 8 is relatively large, at 3mm, providing ample chip space. Chip-breaking grooves 4 are arranged along the length of the main cutting edge 1, with a groove depth of 1.5mm and a V-shaped cross-section, effectively breaking up chips and allowing them to be smoothly discharged, avoiding the impact of chips on the surface finish. The symmetrically arranged positioning grooves 2 on the short side of the blade body fit tightly with the positioning structure on the tool holder, ensuring precise positioning of the blade during machining.

[0043] The positioning surface 3 is located on a main plane (the plane in the thickness direction) of the insert body. The main cutting edge rake face 5 is located on the same side of the positioning surface 3 and extends to the tooth 8. The main cutting edge rake face 5 is an inclined plane, forming an acute angle of 15° with the plane where the tooth tip is located. This inclined plane is continuously distributed along the tool feed direction to optimize chip removal.

[0044] The coating on the main cutting edge 1 is a thick film alumina coating, which provides excellent high-temperature stability and resistance to crater wear, making it suitable for roughing with large feed rates.

[0045] Obviously, the above-described embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A circular arc-shaped cutting edge broaching blade, comprising a blade body, characterized in that, The blade body includes a main cutting edge, a positioning groove, a positioning surface, and cutting teeth. The main cutting edge is an arc-shaped edge set on the top of the cutting teeth. The cutting teeth are evenly distributed along the long side of the blade body, and the cutting teeth on both sides are symmetrically arranged about the central axis of the blade. Chip-breaking grooves extending axially are provided between adjacent cutting teeth. The positioning surface has a main cutting edge rake face on one side, which extends to the cutting teeth and is transitionally connected to the positioning surface. The positioning groove is symmetrically arranged on the short side of the blade body.

2. The arc-shaped cutting edge broaching blade according to claim 1, characterized in that, The blade body is a rectangular parallelepiped structure, and a screw hole is provided at the geometric center of the blade body. The screw hole penetrates the positioning surface and is used to fix the blade body to the handle with a screw.

3. The arc-shaped cutting edge broaching blade according to claim 1, characterized in that, The chip-dispersing grooves are arranged along the length of the main cutting edge, and the chip-dispersing grooves between adjacent main cutting edges are symmetrically distributed. The groove depth of the chip-dispersing grooves is 0.5 to 2 mm.

4. The arc-shaped cutting edge broaching blade according to claim 3, characterized in that, The cross-section of the chip-dispersing groove is V-shaped or rectangular.

5. A circular arc-shaped cutting edge broaching blade according to claim 1, characterized in that, The blade body is also provided with marking points, which are raised or recessed structures on the positioning surface and are used to indicate the installation direction.

6. The arc-shaped cutting edge broaching blade according to claim 1, characterized in that, The tooth profile angle of the main cutting edge is 60°, and the tooth tip radius of the main cutting edge located at the tooth tip is 0.1 mm.

7. A circular arc-shaped broaching blade according to claim 6, characterized in that, The width and height of the tooth tip arc are 0.4 mm and 0.1 mm, respectively.

8. A circular arc-shaped cutting edge broaching blade according to claim 1, characterized in that, The spacing between adjacent cutting teeth is 2 to 3 mm.

9. A circular arc-shaped cutting edge broaching blade according to claim 1, characterized in that, The blade body is made of cemented carbide, and the surface of the main cutting edge is coated.

10. A circular arc-shaped cutting edge broaching blade according to claim 1, characterized in that, The rake face of the main cutting edge is an inclined plane that forms a preset acute angle with the plane containing the tooth tip of the main cutting edge, and is continuously distributed along the tool feed direction to optimize the chip removal path during cutting.

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