Conical tooth broach

Abstract

The utility model discloses a taper tooth broach, including blade main part, the blade main part is cuboid structure, be equipped with multiple taper tooth along its length direction distribution on the blade main part, be equipped with along the cutting edge of axial direction on the taper tooth, and each cutting edge is in radial taper distribution, the blade main part still includes side locating surface, bottom locating surface and chip breaker, the chip breaker is provided with a plurality, and evenly distributes in the long side department of blade main part, and the chip breaker is adjacent with the taper tooth setting, side locating surface and bottom locating surface are perpendicular to each other, the utility model makes each tooth can stagger and participate in cutting, and each tooth can be effectively utilized, and the cutting allowance of each tooth also greatly reduces, improves the service life of blade.

Description

Technical Field

[0001] This utility model belongs to the field of broaching tool technology, and in particular, relates to a tapered tooth broach. Background Technology

[0002] A tapered broach is a precision tool specifically designed for broaching tapered spline holes or tapered internal gears. Its core feature is that the diameter or tooth profile of its cutting teeth gradually and precisely increases along the length of the tool body, allowing it to directly cut a pre-machined hole (usually a round hole) into the final shape of a tapered internal spline or internal gear in a single linear broaching stroke. Compared to traditional spur broaches, tapered broaches can complete both roughing and finishing processes in a single pass, significantly improving machining efficiency and quality, making them suitable for high-precision, high-volume production.

[0003] In existing tapered broaches, all teeth lie on the same plane. The teeth at the rear of the cutting direction do not participate in the cutting process; instead, they primarily serve a finishing function. Furthermore, the more teeth involved in finishing, the greater the resistance during cutting may be, reducing broaching efficiency and leading to accelerated tool wear and a decline in workpiece surface quality. Additionally, an excessively long finishing edge can cause uneven stress on the workpiece, resulting in tool vibration.

[0004] Existing patent application CN206153599U discloses a multi-blade broaching insert for machining crankshaft journals. The insert includes an insert body, a tool mounting hole on the insert body, and cutting edges on two cutting faces of the insert body. The insert body is a flat plate type, and each cutting face has multiple identical protrusions. The top of each protrusion is the cutting edge, and a gap is left between each pair of adjacent protrusions. The cutting edge of the cutting edge is higher than the surface of the gap. In this patent, all the teeth of the broaching insert are on the same plane, and the teeth behind in the cutting direction do not participate in the cutting. This may increase the resistance during the cutting process, reducing broaching efficiency and leading to accelerated tool wear and a decrease in workpiece surface quality. Utility Model Content

[0005] This utility model addresses the issue that in existing tapered tooth broaches, all teeth are on the same plane, and the rear teeth in the cutting direction do not participate in cutting. The rear teeth mainly serve a finishing function. Moreover, the more teeth involved in finishing, the greater the resistance during the cutting process, which not only reduces broaching efficiency but also leads to accelerated tool wear and a decline in workpiece surface quality. At the same time, an excessively long finishing edge may cause uneven force on the workpiece, resulting in tool vibration. Therefore, this invention proposes a tapered tooth broach.

[0006] A tapered broach includes a cutter body in the shape of a cuboid. The cutter body has multiple tapered teeth distributed along its length, each tapered tooth having an axial cutting edge, and these cutting edges are tapered radially. The cutter body also includes a side locating surface, a bottom locating surface, and chip breaker platforms. Multiple chip breaker platforms are evenly distributed along the long side of the cutter body and are adjacent to the tapered teeth. The side locating surface and the bottom locating surface are perpendicular to each other. The bottom locating surface is along the length of the cutter body, and the side locating surfaces are along the short side of the cutter body.

[0007] Furthermore, a screw hole penetrating the bottom positioning surface is provided at the center of the blade body for mounting and fixing the blade.

[0008] Furthermore, the tooth profile angle of the tapered tooth is 60°, and the tooth profile cone angle is the included angle between the two tooth surfaces of the tapered tooth.

[0009] Furthermore, the difference in the gyration radius between the cutting edge centers of two adjacent tapered teeth is 0.06 mm, and along the length direction of the blade body, the gyration radius of the cutting edge centers of each tapered tooth is distributed in an increasing or decreasing manner.

[0010] Furthermore, the flatness error of the bottom positioning surface is ≤0.02mm.

[0011] Furthermore, an identification character is provided on the side of the blade body away from the tapered tooth. The identification character is adjacent to the bottom positioning surface and is used to indicate the taper direction of the tapered tooth.

[0012] Furthermore, the cutting edges are arranged along the same conical surface and form a 1° taper.

[0013] Furthermore, the tapered teeth are symmetrically distributed, and a tooth groove is formed between two adjacent tapered teeth. The depth of the tooth groove gradually changes from one end of the blade body to the other end.

[0014] Furthermore, the bottom positioning surface is a planar structure and is perpendicular to the axis of the blade body.

[0015] Furthermore, the tapered broach is suitable for broaching operations, and the tapering direction is consistent with the broach cutting direction during installation.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. The blade body of this utility model has a rectangular parallelepiped structure, and multiple tapered teeth are distributed along its length. Each tapered tooth has an axial cutting edge, and the cutting edges are tapered in the radial direction. The blade body also includes a side positioning surface, a bottom positioning surface, and a chip breaker. Multiple chip breaker platforms are evenly distributed along the long side of the blade body, and the chip breaker platforms are adjacent to the tapered teeth. The side positioning surface and the bottom positioning surface are perpendicular to each other. This utility model designs tapered teeth with tooth angles adapted to the broaching process requirements, effectively cutting and removing chips. Combined with the chip breaker platforms, chip breaking is smoother, preventing chips from entangled in the tool or scratching the workpiece surface, thus improving processing efficiency and surface quality.

[0017] 2. This utility model forms a 1° taper on the cutting edges of adjacent taper teeth, allowing each tooth to participate in cutting in a staggered manner, so that each tooth can be effectively utilized and the cutting allowance of each tooth is greatly reduced, thereby improving the service life of the cutting tool. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an enlarged schematic diagram of the tapered tooth structure of this utility model; In the above figure, 1. Tapered tooth; 2. Side locating surface; 3. Bottom locating surface; 4. Chip breaker; 5. Screw hole; 6. Cutting edge; 7. Identification letter. Detailed Implementation

[0019] To clearly illustrate the technical features of this utility model, the following detailed description, in conjunction with the accompanying drawings, provides a comprehensive overview of the present utility model. Many specific details are set forth in the following description to facilitate a thorough understanding of the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present utility model is not limited to the specific embodiments disclosed below. Furthermore, 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 used only for the convenience of describing the present utility model and simplifying the description. They 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 the present 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. Therefore, features defined as "first" and "second" can explicitly or implicitly include one or more of those features. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified. In this utility model, unless otherwise explicitly specified and limited, terms such as "installed," "connected," "joined," and "fixed" 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 connection 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. In this utility model, unless otherwise explicitly specified and limited, "on" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in 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," etc., 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 the present invention. 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.

[0020] Example 1 like Figure 1 and Figure 2As shown, a tapered tooth broach includes a blade body, which has a cuboid structure and multiple tapered teeth 1 distributed along its length. Each tapered tooth 1 has a cutting edge 6 along the axial direction, and each cutting edge 6 is tapered in the radial direction. The blade body also includes a side positioning surface 2, a bottom positioning surface 3, and a chip breaker 4. Multiple chip breaker 4s are provided and evenly distributed along the long side of the blade body, and the chip breaker 4s are arranged adjacent to the tapered teeth 1. The side positioning surface 2 and the bottom positioning surface 3 are perpendicular to each other.

[0021] In this embodiment, the blade body has a rectangular parallelepiped structure and is made of cemented carbide to ensure the blade's strength and wear resistance. Ten tapered teeth 1 are symmetrically arranged along the length of the blade, with a spacing of 10mm between adjacent tapered teeth 1.

[0022] like Figure 2 As shown, each tapered tooth 1 on the same side has a sharp cutting edge 6 at its top, and the cutting points of all cutting edges 6 (i.e., the center points of the cutting edges 6) strictly follow a 1° taper distribution in the radial direction. These points, when connected, form a 1° micro-cone, ensuring that each tapered tooth 1 is radially staggered. This guarantees that every tapered tooth 1 participates in cutting and shares the cutting allowance, significantly reducing the cutting force and load on a single tooth. The tooth profile angle of the tapered tooth 1 is set to 60°. Along the length of the insert body, from the starting end to the ending end, the center radius of rotation of the cutting edge 6 of each tapered tooth 1 increases sequentially, and the difference in center radius of rotation between two adjacent tapered teeth 1 is strictly controlled to be 0.06 mm. Simultaneously, the tapered teeth 1 on both sides are symmetrically distributed, and tooth grooves are formed between adjacent tapered teeth 1. The depth of the tooth grooves gradually changes from the starting end to the ending end of the insert body.

[0023] In this embodiment, the blade body has a side positioning surface 2 and a bottom positioning surface 3. The flatness error of the bottom positioning surface 3 is ensured to be within 0.02mm through precision grinding to ensure stability during installation. One short side of the blade body is the side positioning surface 2. This side positioning surface 2 and the bottom positioning surface 3 are precision machined to ensure that they are perpendicular to each other, and are used to achieve precise radial and axial positioning in the cutter head mounting groove. At the center of the blade body, a screw hole 5 is provided through the bottom positioning surface 3, which is used to firmly press the blade into the mounting groove of the broach body with an internal hexagon screw to prevent the blade from shifting during machining.

[0024] Each tapered tooth 1 on the insert body is equipped with a chip breaker 4 at its front. The chip breaker 4 is arranged adjacent to the tapered tooth 1 and is evenly distributed to effectively break the chips during broaching, control the flow direction and shape of the chips, and improve chip removal. On the side of the insert body away from the tapered tooth 1 (located on the bottom positioning surface 3), a marking 7 is laser-engraved. The marking 7 consists of the letters S and E, which is used to quickly indicate the taper direction of the tapered tooth 1 for easy installation by the operator.

[0025] During installation, ensure that the taper reduction direction is consistent with the broach cutting direction, according to the direction indicated by marking 7. Align the side positioning surface 2 of the insert body with the positioning groove of the tool holder, and ensure the bottom positioning surface 3 is in close contact with the mounting plane of the tool holder. Secure the tool using the screws in the screw holes 5. During machining, the broaching machine drives the broach to move axially. The cutting edges 6 on the tapered teeth 1 progressively broach the inner holes of shaft-like parts. Because each cutting edge 6 is tapered and its radius of rotation gradually increases, continuous forming of the inner tapered hole can be achieved. Simultaneously, the chip breaker 4 promptly cuts off the chips, ensuring the quality of the machined surface.

[0026] Example 2 like Figure 1 and Figure 2 As shown, a tapered tooth broach includes a blade body, which has a cuboid structure and multiple tapered teeth 1 distributed along its length. Each tapered tooth 1 has a cutting edge 6 along the axial direction, and each cutting edge 6 is tapered in the radial direction. The blade body also includes a side positioning surface 2, a bottom positioning surface 3, and a chip breaker 4. Multiple chip breaker 4s are provided and evenly distributed along the long side of the blade body, and the chip breaker 4s are arranged adjacent to the tapered teeth 1. The side positioning surface 2 and the bottom positioning surface 3 are perpendicular to each other.

[0027] In this embodiment, the insert body is made of ultra-fine grain cemented carbide with an AlTiN coating to improve wear resistance and high temperature resistance. Twelve tapered teeth 1 are arranged along the length of the insert body, with an 8mm spacing between adjacent tapered teeth 1. The tooth profile angle of the tapered teeth 1 is 60°, the taper formed by continuous cutting edges 6 is 1°, the difference in the center gyration radius between adjacent cutting edges 6 is 0.06mm, and the gyration radius decreases along the cutting direction (the length of the insert body), i.e., the starting end is the tapered expansion end and the ending end is the tapered contraction end, suitable for broaching thin-walled parts from a large hole to a small hole diameter, reducing the impact of cutting force on the part. The flatness error of the bottom positioning surface 3 is controlled within 0.015mm, and the bottom positioning surface 3 and the side positioning surface 2 are perpendicular to each other and both are planes.

[0028] On the long side of the insert body, a chip breaker 4 is provided on one side of each tapered tooth 1. The chip breaker 4 adopts an arc-shaped transition structure with a height of 1.2mm, which can guide the chips to be discharged along the arc surface and reduce the friction of the chips on the inner wall of thin-walled parts. A screw hole 5 is provided in the center of the insert body to enhance the connection stability between the tool and the tool holder and prevent tool vibration during high-speed broaching.

[0029] Example 3 like Figure 1 and Figure 2 As shown, a tapered tooth broach includes a blade body, which has a cuboid structure and multiple tapered teeth 1 distributed along its length. Each tapered tooth 1 has a cutting edge 6 along the axial direction, and each cutting edge 6 is tapered in the radial direction. The blade body also includes a side positioning surface 2, a bottom positioning surface 3, and a chip breaker 4. Multiple chip breaker 4s are provided and evenly distributed along the long side of the blade body, and the chip breaker 4s are arranged adjacent to the tapered teeth 1. The side positioning surface 2 and the bottom positioning surface 3 are perpendicular to each other.

[0030] In this embodiment, a 10mm diameter screw hole 5 is provided at the center of the insert body. A high-strength internal hexagon screw is used for fixing, with the screw head embedded inside the insert body to avoid interference with the cutting process. A chip breaker 4 is also located on the long side of the insert body and corresponds adjacent to each taper tooth 1. The bottom positioning surface 3 and the side positioning surface 2 are always perpendicular to each other, ensuring accurate installation regardless of which side is used for positioning. The marking 7 clearly indicates the taper reduction direction in the current installation state to prevent installation errors.

[0031] 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 tapered broach, comprising a blade body, characterized in that, The blade body has a cuboid structure and multiple tapered teeth distributed along its length. Each tapered tooth has an axial cutting edge, and the cutting edges are tapered in the radial direction. The blade body also includes a side positioning surface, a bottom positioning surface, and chip breaker platforms. Multiple chip breaker platforms are evenly distributed along the long side of the blade body, and the chip breaker platforms are adjacent to the tapered teeth. The side positioning surface and the bottom positioning surface are perpendicular to each other.

2. The tapered tooth broach according to claim 1, characterized in that, The blade body has a screw hole at its center that penetrates the bottom positioning surface for mounting and fixing the blade.

3. A tapered tooth broach according to claim 1, characterized in that, The tooth profile angle of the tapered tooth is 60°, which is the included angle between the two tooth surfaces of the tapered tooth.

4. A tapered tooth broach according to claim 1, characterized in that, The difference in gyration radius between the cutting edge centers of two adjacent taper teeth is 0.06 mm, and along the length direction of the blade body, the gyration radius of the cutting edge centers of each taper tooth is distributed in an increasing or decreasing manner.

5. A tapered tooth broach according to claim 1, characterized in that, The flatness error of the bottom positioning surface is ≤0.02mm.

6. A tapered tooth broach according to claim 1, characterized in that, The blade body has an identification mark on the side away from the tapered tooth. The identification mark is adjacent to the bottom positioning surface and is used to indicate the taper direction of the tapered tooth.

7. A tapered tooth broach according to claim 1, characterized in that, The cutting edges are arranged along the same conical surface and form a 1° taper.

8. A tapered tooth broach according to claim 1, characterized in that, The tapered teeth are symmetrically distributed, and a groove is formed between two adjacent tapered teeth. The depth of the groove gradually changes from one end of the blade body to the other end.

9. A tapered tooth broach according to claim 1, characterized in that, The bottom positioning surface is a planar structure and is perpendicular to the axis of the blade body.

10. A tapered tooth broach according to any one of claims 1 to 9, characterized in that, The tapered broach is suitable for broaching operations, and the tapering direction is consistent with the broach cutting direction during installation.

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