Double-sided indexable insert, roughing insert, finishing turning insert

Abstract

The utility model provides a kind of double-sided indexable insert, rough machining insert, finish machining turning insert, the part of cutting edge of insert not involved in cutting is set into negative chamfer structure, the structural strength of cutting edge in chip flinging and beating position is enhanced by setting negative chamfer structure, and the risk of collapse of insert is reduced.The utility model does not change the material of insert, also does not affect the groove structure parameter of cutting edge cutting part, and does not need to reset chip flute, only the part of cutting edge of insert not involved in cutting is set into negative chamfer structure.Negative chamfer structure disperses stress, so that the part of insert often hit by chip has better structural strength, thereby reducing the risk of collapse of insert.Especially when the insert is finish machining insert, the utility model does not set negative chamfer structure in the part of cutting edge involved in cutting, does not change the structure of the part of cutting edge involved in cutting, so that the part maintains its original sharp degree and chip force, and can ensure finish machining quality.

Description

Technical Field

[0001] This utility model relates to the field of machining tool technology, and more specifically, to a double-sided indexable insert, a roughing insert, and a finishing insert. Background Technology

[0002] Chipping refers to the damage or breakage of the cutting edge of a cutting tool during use. Chipping is mainly caused by insufficient material toughness and impact from hard objects. Insufficient material toughness prevents the tool from effectively resisting the propagation of cracks; impact from hard objects includes cutting edge damage caused by the tool cutting hard objects and cutting edge damage caused by chips impacting the tool.

[0003] For example, patent application number 202411457342.6, entitled "Cutting Inserts and Tools," addresses a situation where cutting edges are damaged when a tool cuts hard objects. This patent enhances the strength of the cutting edge by incorporating side negative chamfers and rounded negative chamfers, thus preventing chipping during heavy turning operations due to large cutting allowances, high cutting forces, and high cutting temperatures. As shown in the attached drawings of this patent, side negative chamfers are provided on the outer side of the side cutting edge, and rounded negative chamfers are also provided on the outer side of the arc-shaped cutting edge. The method of this patent essentially increases the strength of the cutting edge and improves the chipping resistance of the insert by blunting the cutting edge and reducing its sharpness.

[0004] Chip impact damage to cutting edges occurs specifically when machining metal workpieces with cutting tools. This generates numerous chips, which impact the cutting edge and cause chipping. This is especially true for finishing inserts, whose sharper cutting edges are more susceptible to chipping from chip impact. During face-cutting, chips can strike the unused cutting edge (bottom edge) on the reverse side, resulting in a certain percentage of the bottom edge being chipped, affecting its usability and the tool's economic efficiency. To prevent this chipping, technicians primarily use the following two methods to avoid bottom edge chipping.

[0005] Method 1: Using a more resilient material to resist the impact of chips. The disadvantage of this method is that the more resilient material is not wear-resistant. Although the chips no longer damage the bottom edge, the more resilient knife is not wear-resistant. The hardness and toughness of knife materials are often opposites and cannot be achieved simultaneously.

[0006] Method Two: Changing the chip-throwing position by repeatedly adjusting the groove structure parameters of the cutting area. Those skilled in the art know that the groove parameters are the most reasonable solutions determined through repeated verification. While changing the groove parameters to alter the chip-throwing position prevents the chips from hitting the bottom edge, it affects the structural rationality of the cutting edge during normal use. For example, utility model patent application number 201520541819.9, entitled "Indexable Turning Inserts," points out in its background art that due to the chaotic rotation and curling of chips, and the lack of…

[0007] The inability to promptly break and remove chips can impact the cutting tool, causing breakage and chipping, thus reducing tool life. This patent features a double-rake-angle chip breaker structure, as shown in the attached diagram. The first rake angle (δ) is 4°-8° with the horizontal plane, and the second rake angle (ε) is 12°-18° with the horizontal plane. This unique chip-breaking boss structure effectively lifts and bends the chips, guiding their flow and reducing impact on the cutting tool. This patent utilizes adjustable groove parameters to alter the chip-throwing position, thereby reducing chipping. Utility Model Content

[0008] This invention addresses the issue of chipping caused by chip impact on the cutting edge during machining. Existing technologies, which alter the toughness of the material and adjust the groove structure parameters of the cutting area on the insert to change the position of the chipping, cannot effectively solve the problem of chipping at the bottom edge. This invention provides a double-sided indexable insert, a roughing insert, and a finishing insert.

[0009] This utility model provides a double-sided indexable insert, including a top surface, a bottom surface, and a side surface between the top and bottom surfaces. The side surface is a side cutting edge at the junction with the top or bottom surface, and the arc transition between each pair of side cutting edges is an arc cutting edge. The part of the side cutting edge that does not participate in cutting is set with a negative chamfer structure.

[0010] This utility model's negative chamfer structure is essentially a type of chamfer. By altering the stress distribution in the area where the blade is struck, it significantly reduces the risk of blade chipping. Since no structural changes are made to the cutting edge, this area can still cut normally, without affecting the rationality of the blade's cutting parameters. In contrast, the negative chamfer structure in the prior art patents surrounds the entire circumference of the blade, including the tip. This utility model, however, does not change the groove structure parameters of the cutting part; it only improves the structure of the non-cutting parts, enhancing their structural strength.

[0011] Furthermore, the circular arc cutting edge has a cutting edge band, and the part of the side cutting edge that participates in cutting also has a cutting edge band; the part of the side cutting edge that does not participate in cutting is not provided with a cutting edge band, but is provided with the negative chamfer structure.

[0012] Furthermore, the cutting edge of the side cutting edge that participates in the cutting is connected to the negative chamfer structure by a circular arc transition.

[0013] Furthermore, the axis passing through the center of the top and bottom surfaces is called the central axis of the blade, and the plane on the blade perpendicular to the central axis is called the reference plane. The angle between the negative chamfer structure and the reference plane is -20° to -15°.

[0014] The double-sided indexable insert described in this utility model can be a roughing insert or a finishing insert. Its characteristic is that it is a double-sided indexable insert with multiple cutting edges; the number of cutting edges is any number greater than 2.

[0015] This utility model also provides a double-sided indexable finishing cutting tool, which is a specific application of the double-sided indexable tool described above.

[0016] Furthermore, the top surface has an inclined surface that slopes from the side cutting edge toward the inside of the insert, and the inclined surface has two wavy chip guide grooves extending along the side cutting edge, with the rake face of the insert between each pair of chip guide grooves; the bottom surface has the same structure as the top surface.

[0017] Furthermore, the blade is provided with a positioning hole that penetrates the top surface and the bottom surface, and the blade is threaded to the blade shank after passing through the positioning hole by a locking screw.

[0018] Furthermore, each of the inclined surfaces and each arc cutting edge has a corresponding mounting and positioning surface; when assembling the insert, the mounting and positioning surface at the corresponding arc cutting edge that does not participate in cutting cooperates with the tool holder to position the insert.

[0019] Furthermore, the top and bottom surfaces are symmetrically distributed, each having four identical side cutting edges and four identical circular arc cutting edges. The four circular arc cutting edges are evenly distributed at 90 degrees along the axis of the positioning hole, and the cutting edges on both sides are connected by the circular arc cutting edges.

[0020] This utility model has the following beneficial effects:

[0021] Existing technologies use materials with better toughness to resist the impact force of chips, but toughness and hardness are often inversely related and cannot be balanced. Materials with better toughness are also less wear-resistant, making them impractical for high-speed rotating inserts. Alternatively, adjusting the groove structure parameters of the cutting area can alter the chip impact position, preventing chips from hitting the bottom edge, but this affects the structural rationality of the cutting edge during normal use. This invention reduces the risk of insert chipping by not changing the insert material or affecting the groove structure parameters of the cutting edge. It only sets a negative chamfer structure on the non-cutting parts of the insert. The negative chamfer structure disperses stress, giving better structural strength to the parts of the insert frequently hit by chips, thus reducing the risk of chipping. Furthermore, when the insert is a finishing insert with a relatively sharp cutting edge, this invention does not use a negative chamfer structure on the cutting parts, maintaining the original sharpness and cutting force of these parts and ensuring finishing quality. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of the finishing turning tool structure in Example 3;

[0024] Figure 2 A simulation diagram of the workpiece, cutting tool, and chip path;

[0025] Figure 3 for Figure 2 Enlarged view of point C.

[0026] The serial numbers are: 1-top surface, 2-bottom surface, 3-side surface, 4-side cutting edge, 5-circular arc cutting edge, 6-negative chamfer structure, 7-cutting edge, 8-transition between cutting edge and negative chamfer structure, 9-positioning hole, 10-mounting positioning surface, 11-bevel, 12-chip guide groove, 13-rake face. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0028] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," 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 or an electrical 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 based on the specific circumstances.

[0029] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of description and simplification of operation. They are not intended to 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.

[0030] Example 1

[0031] A double-sided indexable insert includes a top surface, a bottom surface, and a side surface between the top and bottom surfaces. The side surface is a side cutting edge at the junction with the top or bottom surface, and the arc transition between any two side cutting edges is an arc cutting edge. The portion of the side cutting edge that does not participate in cutting is configured with a negative chamfer structure.

[0032] The circular arc cutting edge has a cutting edge band, and the part of the side cutting edge that participates in cutting also has a cutting edge band; the part of the side cutting edge that does not participate in cutting does not have a cutting edge band, but is provided with the negative chamfer structure.

[0033] The cutting edge of the side cutting edge that participates in the cutting is connected to the negative chamfer structure by a circular arc transition.

[0034] The axis passing through the center of the top and bottom surfaces is called the central axis of the blade, and the plane on the blade perpendicular to the central axis is called the reference plane. The angle between the negative chamfer structure and the reference plane is -20° to -15°.

[0035] Existing technologies use materials with better toughness to resist the impact force of chips, but toughness and hardness are often inversely related and cannot be balanced. Materials with better toughness are also less wear-resistant, making them impractical for high-speed rotating inserts. Alternatively, adjusting the groove structure parameters of the cutting area can alter the chip impact position, preventing chips from hitting the bottom edge, but this can affect the structural rationality of the cutting edge during normal use. The method for reducing the risk of insert chipping described in this embodiment does not change the insert material or affect the groove structure parameters of the cutting edge; it only sets a negative chamfer structure on the non-cutting parts of the insert. The negative chamfer structure disperses stress, giving better structural strength to the parts of the insert frequently hit by chips, thereby reducing the risk of insert chipping. Furthermore, when the insert is a finishing insert with a relatively sharp cutting edge, this embodiment does not set a negative chamfer structure on the parts where the cutting edge participates in cutting, thus maintaining the original sharpness and cutting force of these parts.

[0036] Example 2

[0037] The double-sided indexable insert described in Example 1 can be used as a roughing insert or a finishing insert. Regardless of whether the cutting edge is relatively sharp or relatively blunt, stress can be dispersed and the risk of insert chipping can be reduced by setting the non-cutting part of the side cutting edge to a negative chamfer structure. This example provides a roughing insert. Example 2 is a specific application of the double-sided indexable insert described in Example 1, and is a double-sided indexable roughing insert.

[0038] Example 3

[0039] An indexable cutting tool for finishing, Embodiment 3 is a specific application of the indexable cutting tool described in Embodiment 1, and is a double-sided indexable finishing cutting tool. The finishing cutting tool includes a top surface 1, a bottom surface 2, and a side surface 3 between the top surface 1 and the bottom surface 2. The side surface 3 is a side cutting edge 4 at the junction with the top surface 1 or the bottom surface 2, and the arc transition between any two side cutting edges 4 is an arc cutting edge 5. The part of the side cutting edge 4 that does not participate in cutting is provided with a negative chamfer structure 6.

[0040] like Figure 1 As shown, the arc-shaped cutting edge 5 has a cutting edge band 7, and the part of the side cutting edge 4 that participates in cutting also has a cutting edge band 7. The part of the side cutting edge 4 that does not participate in cutting does not have a cutting edge band, but is provided with the negative chamfer structure 6. In this embodiment, the part that does not participate in cutting is a part of the side cutting edge 4.

[0041] The cutting edge 7 of the side cutting edge 4, which participates in the cutting, is connected to the negative chamfer structure 6 by a circular arc transition.

[0042] The axis passing through the center of the top surface 1 and the bottom surface 2 is called the central axis of the blade. The plane on the blade that is perpendicular to the central axis is called the reference plane. The angle between the negative chamfer structure 6 and the reference plane is -20° to -15°. In this embodiment, the chamfer angle of the negative chamfer structure 6 is -15°.

[0043] The top surface 1 has an inclined surface 11 that slopes from the side cutting edge 4 toward the inside of the insert. The inclined surface 11 has two wavy chip guide grooves 12 that extend along the side cutting edge. Between each pair of chip guide grooves 12 is the rake face 13 of the insert. The bottom surface 2 has the same structure as the top surface 1.

[0044] The blade is provided with a positioning hole 9 that penetrates the top surface 1 and the bottom surface 2. The blade is threaded to the blade shank after passing through the positioning hole 9 with a locking screw.

[0045] Each inclined surface 11 and each arc cutting edge 5 is provided with a mounting and positioning surface 10; when assembling the cutting tool, the mounting and positioning surface 10 at the corresponding position of the arc cutting edge 5 that does not participate in cutting cooperates with the tool holder to position the cutting tool.

[0046] The top surface 1 and bottom surface 2 are symmetrically distributed. Both the top surface 1 and bottom surface 2 have four identical side cutting edges 4 and four identical arc cutting edges 5. The four arc cutting edges 5 are evenly distributed at 90 degrees along the axis of the positioning hole 9, and the cutting edges on both sides are connected by the arc cutting edges 5.

[0047] The phenomenon of the bottom cutting edge of a double-sided finishing turning insert being chipped by chips is very common, but this process is very difficult to capture on camera. Therefore, cutting simulation technology is used to demonstrate this process for easier understanding. For example... Figure 2 As shown in the diagram, where number C represents the trajectory of the chip, the simulation shows that the chip struck the bottom cutting edge. Figure 3 The image shown is an enlarged view of the contact area between the chip and the bottom cutting edge in the diagram above. The finishing cutting tool described in this embodiment has been put into practical use, and customer feedback has been positive.

[0048] like Figure 1As shown, the finishing cutting insert described in this embodiment has eight cutting tips and can be used eight times, offering excellent economic efficiency. During finishing, the top surface 1 and bottom surface 2 are symmetrical, with a total of four pairs of side cutting edges 4 and four pairs of circular cutting edges 5 on both surfaces. During clamping, three pairs of circular cutting edges 5 are positioned with the tool holder. The pair of circular cutting edges not positioned with the tool holder is named circular cutting edge A. The part of the side cutting edge connected to circular cutting edge A that does not participate in cutting (named part B) is subjected to chip impact, making part B prone to chipping. This embodiment improves the structure of part B by chamfering it to form a negative chamfer structure 6. The chamfer disperses stress and increases the structural strength of part B. The biggest difference between this embodiment and existing technologies is that it does not improve the structure of the circular cutting edges and the side cutting edges that participate in cutting; their structures remain unchanged, ensuring the finishing cutting insert has good sharpness and suitable cutting force, guaranteeing the quality of finishing.

[0049] It should be noted that the technical solution of this embodiment differs from the patent described in the background (application number 202411457342.6). The comparative patent addresses the technical problem of chipping during heavy-duty cutting due to large cutting allowances, high cutting forces, and high cutting temperatures. This chipping is caused by the tool cutting hard materials, and it can be inferred that the insert described in that patent is a roughing insert. That patent also modifies the flute parameters to avoid chipping, but changing the flute parameters affects the structural rationality of the cutting edge during normal use. The technical problem addressed in this embodiment is that the bottom edge of a double-sided indexable finishing insert is easily damaged by chip impact.

[0050] The technical problem of chipping is damage to the cutting edge caused by chips impacting the tool. This embodiment addresses a different technical problem than the comparative patent. When the insert is a finishing insert, there is no need to solve the technical problem of chipping caused by large cutting allowances and high cutting forces. The comparative patent uses side negative chamfers and rounded negative chamfers to dull the insert; the negative chamfer structure is set around the circumference of the insert, changing the groove parameters of the cutting edge. This embodiment does not change the groove parameters of the cutting edge's cutting area; it only improves the groove parameters of the non-cutting area, without affecting the structural rationality of the cutting edge during normal use. This ensures that chips hit the bottom edge during use, but greatly reduces the probability of chipping.

[0051] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Various modifications and variations can be made to the present utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the scope of the present utility model.

Claims

1. A double-sided indexable insert, comprising a top surface, a bottom surface, and a side surface between the top and bottom surfaces, wherein the junction of the side surface with the top or bottom surface is a side cutting edge, and the arc transition between any two side cutting edges is an arc cutting edge, characterized in that... The portion of the side cutting edge that does not participate in cutting is configured with a negative chamfer structure.

2. The double-sided indexable cutting tool according to claim 1, characterized in that, The circular arc cutting edge has a cutting edge band, and the part of the side cutting edge that participates in cutting also has a cutting edge band; the part of the side cutting edge that does not participate in cutting does not have a cutting edge band, but is provided with the negative chamfer structure.

3. The double-sided indexable cutting tool according to claim 2, characterized in that, The cutting edge of the side cutting edge that participates in the cutting is connected to the negative chamfer structure by a circular arc transition.

4. The double-sided indexable cutting tool according to claim 3, characterized in that, The axis passing through the center of the top and bottom surfaces is called the central axis of the blade, and the plane on the blade perpendicular to the central axis is called the reference plane. The angle between the negative chamfer structure and the reference plane is -20° to -15°.

5. A roughing cutting tool, characterized in that, This refers to the specific application of the double-sided indexable insert as described in any one of claims 2 to 4.

6. A finishing lathe blade, characterized in that, This refers to the specific application of the double-sided indexable insert as described in any one of claims 2 to 4.

7. The finishing turning tool according to claim 6, characterized in that, The top surface has an inclined surface that slopes from the side cutting edge toward the inside of the insert. The inclined surface has two wavy chip guide grooves that extend along the side cutting edge. The rake face of the insert is between each pair of chip guide grooves. The bottom surface has the same structure as the top surface.

8. The finishing lathe blade according to claim 7, characterized in that, The blade is provided with a positioning hole that penetrates the top and bottom surfaces. The blade is threaded to the blade shank after passing through the positioning hole with a locking screw.

9. The finishing lathe blade according to claim 8, characterized in that, Each inclined surface and each arc cutting edge has a corresponding mounting and positioning surface; when assembling the insert, the mounting and positioning surface at the corresponding arc cutting edge that does not participate in cutting cooperates with the tool holder to position the insert.

10. The finishing lathe blade according to claim 9, characterized in that, The top and bottom surfaces are symmetrically distributed, each with four identical side cutting edges and four identical arc cutting edges. The four arc cutting edges are evenly distributed at 90 degrees along the axis of the positioning hole, and the cutting edges on both sides are connected by the arc cutting edges.

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