A roughing tool insert and a roughing cutting method

Abstract

The application provides a rough turning blade and a rough machining cutting method, and relates to the field of machining. The rough turning blade provided by the embodiment of the application has opposite first and second end faces and a side face between the first and second end faces. The side face comprises a plurality of side planes and side curved surfaces connecting adjacent side planes, the intersection of the side curved surfaces and the first end face forms a blade tip, and the intersection of the side planes and the first end face forms a cutting edge. The blade tip and the cutting edge can be used for rough turning. Thus, when cutting a gear, different parts of the rough turning blade can be used to cut the end face hardening layer and the cylindrical surface hardening layer, which helps to prolong the tool life, and the tool does not need to be replaced during the cutting process, so that the beat is shortened. Moreover, two adjacent cutting edges form a group of cutting edges, and the included angle between at least one group of cutting edges is 85°. When the cutting edges are used for rough turning cutting, the cutting edges involved in the cutting are long, the main offset angle is small, the tool life is further prolonged, and the production beat is shortened.

Description

Technical Field

[0001] This invention relates to the field of machining, and more specifically, to a roughing cutting tool and a roughing cutting method. Background Technology

[0002] With the development of new energy vehicle technology, the main gear assembly in the transmission has become a common structure using cylindrical helical gears and welded fork shells to reduce costs and optimize the structure.

[0003] Because the gear material is low-carbon structural steel, heat treatment is necessary to ensure gear strength. However, the fork housing material is cast iron, which cannot be heat treated. Therefore, the mainstream process is to heat treat the gear first and then weld it. To ensure weld strength, the material in the gear welding area cannot be heat treated. After heat treatment, the carburized layer depth reaches 0.35-0.7mm, so at least 1mm of allowance is reserved in the gear welding area. After heat treatment, the carburized hardened layer formed in the reserved allowance area of ​​the gear welding area needs to be removed by cutting. Generally, the hardened layers that need to be removed from the same gear include the end face hardened layer and the cylindrical surface hardened layer. Currently, cutting the end face hardened layer and the cylindrical surface hardened layer is done using the tool tip. The above gear design results in a large hard turning allowance, leading to a short hard turning tool life and a long cycle time. Efficiently and stably rough machining the carburized layer is an urgent problem to be solved in gear machining production lines. Summary of the Invention

[0004] The purpose of this invention is to provide a roughing insert to improve the technical problems of long cycle time and short tool life in the roughing of carburized layers during gear manufacturing.

[0005] The present invention also aims to provide a roughing cutting method to improve the technical problems of long cycle time and short tool life in the roughing of carburized layers during gear manufacturing.

[0006] Embodiments of the present invention can be implemented in the following ways:

[0007] A roughing insert has a first end face and a second end face disposed opposite to each other, and a side surface located between the first end face and the second end face; the side surface includes a plurality of side planes and a side arc surface connecting adjacent side planes, a tool tip is formed at the intersection of the side arc surface and the first end face, and a cutting edge is formed at the intersection of the side planes and the first end face, both the tool tip and the cutting edge can be used for roughing; two adjacent cutting edges constitute a set of cutting edges, and at least one set of cutting edges has an included angle of 85°.

[0008] Optionally, the roughing insert is made of integral CBN material.

[0009] Optionally, the roughing insert has a height direction pointing from the first end face to the second end face, the angle between the side face and the height direction is 7°, and the cross-sectional area of ​​the roughing insert gradually decreases along the height direction.

[0010] Optionally, the cutting edge is provided with a chamfer structure, the chamfer structure including an inclined surface, one end of the inclined surface being connected to the first end face, and the other end of the inclined surface being connected to the side surface via a rounded arc; the angle formed between the inclined surface and the plane containing the first end face is 35°; the radius of the rounded arc is 0.04 mm; the distance between the intersection point of the inclined surface and the side surface and the edge of the first end face on the plane containing the first end face is 0.2 mm.

[0011] Optionally, the radius of the arc of the blade tip is 1.6 mm.

[0012] A rough machining method is used to rough machine a part to be cut, the part having an end face hardened layer and a cylindrical surface hardened layer; the rough machining method includes:

[0013] The hardened layer on the end face is rough-machined;

[0014] The hardened layer on the cylindrical surface is rough-machined using the same roughing tool.

[0015] The roughing insert has a first cutting edge, a second cutting edge, and a tool tip. One of the first cutting edge, the second cutting edge, and the tool tip is used to rough machine the end face hardened layer, and the other of the first cutting edge, the second cutting edge, and the tool tip is used to rough machine the cylindrical surface hardened layer.

[0016] Optionally, the hardened end face layer has no steps on either side, and the rough machining step for the hardened end face layer includes:

[0017] The roughing insert is controlled to feed along the thickness direction of the end face hardened layer, and the end face hardened layer is cut by the first cutting edge;

[0018] During the feeding process, the length direction of the first cutting edge is parallel to the end face hardened layer.

[0019] Optionally, one side of the end-face hardened layer has a step, and the step of rough machining the end-face hardened layer includes:

[0020] The roughing insert is controlled to feed in a direction from the side of the end face hardened layer without steps to the side with steps, and the end face hardened layer is cut by the cutting tip.

[0021] Optionally, the cylindrical surface hardened layer is continuous, and there are no steps on either side of the cylindrical surface hardened layer. The rough machining step of the cylindrical surface hardened layer includes:

[0022] The roughing insert is controlled to feed along the axial direction of the cylindrical surface hardened layer, and the cylindrical surface hardened layer is cut by the second cutting edge;

[0023] During the cutting process, the principal cutting edge angle of the second cutting edge is 5°.

[0024] Optionally, the cylindrical surface hardened layer is continuous, and one side of the cylindrical surface hardened layer has a step. The step of rough machining the cylindrical surface hardened layer includes:

[0025] The roughing insert is controlled to feed in a direction from the side of the cylindrical surface hardened layer without steps to the side with steps, and the cutting edge cuts the cylindrical surface hardened layer.

[0026] Optionally, the cylindrical surface hardened layer is discontinuous, and there are no steps on either side of the cylindrical surface hardened layer. The rough machining step of the cylindrical surface hardened layer includes:

[0027] The roughing insert is controlled to feed along the axial direction of the cylindrical surface hardened layer, and the cylindrical surface hardened layer is cut by the second cutting edge;

[0028] During the cutting process, the second cutting edge only partially participates in the cutting.

[0029] Optionally, the principal cutting edge angle of the second cutting edge is 8°.

[0030] The beneficial effects of the roughing cutting tool and roughing cutting method provided by the embodiments of the present invention include:

[0031] An embodiment of the present invention provides a roughing insert having opposing first and second end faces, and a side surface located between the first and second end faces. This side surface includes multiple side planes and a side arc surface connecting adjacent side planes. The intersection of the side arc surface and the first end face forms a tool tip, and the intersection of the side plane and the first end face forms a cutting edge. Both the tool tip and the cutting edge can be used for roughing. Thus, when cutting gears, different parts of the roughing insert can be used to cut the hardened layer on the end face and the hardened layer on the cylindrical surface, which helps to extend tool life. Tool changes are not required during cutting, shortening the cycle time. Furthermore, two adjacent cutting edges form a set of cutting edges, and the included angle between at least one set of cutting edges is 85°. When using cutting edges for roughing, the cutting edges involved in the cutting are long and the principal cutting edge angle is small, further extending tool life and shortening the production cycle time.

[0032] Embodiments of the present invention also provide a roughing cutting method for machining a part having both an end face hardened layer and a cylindrical surface hardened layer. The same roughing insert is used for roughing both the end face hardened layer and the cylindrical surface hardened layer, eliminating the need for tool changes and helping to shorten the cycle time. Furthermore, the roughing insert has a first cutting edge, a second cutting edge, and a tool tip. Cutting the end face hardened layer and the cylindrical surface hardened layer is performed using different parts of the first cutting edge, the second cutting edge, and the tool tip, thereby helping to extend the tool life. Attached Figure Description

[0033] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0034] Figure 1 A schematic diagram of the structure of a roughing cutting tool according to one aspect of the present invention is shown from a first perspective.

[0035] Figure 2 A schematic diagram of the structure of a roughing cutting tool according to one aspect of the present invention is shown from a second perspective.

[0036] Figure 3 It shows Figure 2 Enlarged schematic diagram of the local structure at point B;

[0037] Figure 4 A schematic diagram of the structure of a gear part according to one aspect of the present invention is shown;

[0038] Figure 5 A schematic diagram of the structure for rough machining of the end face hardened layer of a first type of gear part according to one aspect of the present invention is shown;

[0039] Figure 6 A schematic diagram of the structure for rough machining of the cylindrical surface hardened layer of a first type of gear part according to one aspect of the present invention is shown.

[0040] Figure 7 A schematic diagram of the structure for rough machining of the end face hardened layer of a second type of gear part according to another aspect of the present invention is shown.

[0041] Figure 8 A schematic diagram of the structure for rough machining of the hardened cylindrical surface layer of a second type of gear part according to another aspect of the present invention is shown.

[0042] Figure 9A schematic diagram of the structure for rough machining of the end face hardened layer and the cylindrical surface hardened layer of a third type of gear part, according to another aspect of the present invention, is shown.

[0043] Figure label:

[0044] 100 - Roughing insert; 111 - First end face; 112 - Second end face; 113 - Side face; 114 - Side plane; 115 - Side arc surface; 116 - Tool tip; 117 - Cutting edge; 118 - First cutting edge; 119 - Second cutting edge; 120 - Rounded arc; 121 - Bevel; 200 - Tool body; 311 - First type of gear part; 312 - Second type of gear part; 313 - Third type of gear part; 314 - End face hardening layer; 315 - Cylindrical surface hardening layer; 316 - Step. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0046] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "vertical" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use, and does 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 invention.

[0047] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0048] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; 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, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] Figure 1 This diagram shows a structural schematic of the roughing tool 100 provided in this embodiment from a first-view perspective. Figure 2 This diagram shows a structural schematic of the roughing tool 100 provided in this embodiment from a second perspective. Please refer to the reference. Figure 1 and Figure 2This embodiment provides a roughing tool 100, which includes a first end face 111, a second end face 112, and a side face 113. The first end face 111 and the second end face 112 are distributed vertically at intervals, and the side face 113 is distributed between the first end face 111 and the second end face 112, with both ends of the side face 113 connected to the first end face 111 and the second end face 112, respectively. The side face 113 includes a side plane 114 and a side arc surface 115 located between two adjacent side planes 114. The intersection of the side arc surface 115 and the first end face 111 forms a tool tip 116, and the intersection of the side plane 114 and the first end face 111 forms a cutting edge 117.

[0050] Specifically, the cross-section of the roughing insert 100 in this embodiment is rhomboid, and the "cross-section" is the surface intercepted parallel to the plane of the first end face 111 or the second end face 112. Thus, the roughing insert 100 has four side planes 114, and correspondingly, four side arc surfaces 115. Opposite side planes 114 are distributed in parallel.

[0051] Two adjacent cutting edges 117 constitute a set of cutting edges 117, and the included angle α of at least one set of cutting edges 117 is 85°, that is, the included angle corresponding to at least one tool tip 116 is 85°. It should be understood that the numerical points mentioned in this embodiment do not need to strictly meet the mathematical angle requirements, and values ​​are allowed within a certain tolerance range, for example, within a tolerance range of ±0.5%, that is, (100% ± 0.5%) 85° in a mathematical sense are all within the range of 85° of this invention.

[0052] In this embodiment, there are four blade tips 116, with two of the four blade tips 116 having an included angle of 85° and the other two having an included angle of 95°.

[0053] It is understood that specific terms are used to describe embodiments of the invention, such as "this embodiment," "an embodiment," or "other embodiments," which refer to a particular feature, structure, or characteristic related to at least one embodiment of the invention. Therefore, it should be emphasized and noted that "this embodiment" or "other embodiments" mentioned twice or more in different locations in the description of the invention do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the invention can be appropriately combined.

[0054] When setting the specific dimensions of the roughing cutting tool 100, the following conditions must be met:

[0055] L×sin(90°-α)=D;

[0056] Where L is the effective length of the cutting edge 117 and D is the depth to be cut, both in mm.

[0057] In this embodiment, the cutting depth is set to 0.8 mm according to the cutting requirements. Correspondingly, to ensure the length of the cutting edge 117 meets the requirements, the inscribed circle diameter R of the roughing insert 100 is set to 12.7 mm, and the arc radius r1 corresponding to the tool tip 116 is 1.6 mm. It is understood that in other embodiments, the inscribed circle diameter R can be specifically set according to the required cutting thickness to obtain the required cutting edge 117 length. Correspondingly, the arc radius r1 can also be set according to requirements.

[0058] In this embodiment, the roughing insert 100 is made of integral CBN (cubic boron nitride) material, that is, the roughing insert 100 provided in this embodiment can be made of CBN material in one piece.

[0059] In this embodiment, the roughing insert 100 has a height direction from the first end face 111 to the second end face 112 (i.e., Figure 2 In the direction A), the angle β between the side surface 113 and the height direction is 7°, and the cross-sectional area of ​​the roughing insert 100 gradually decreases along the height direction. Thus, the area of ​​the first end face 111 of the roughing insert 100 is larger than the area of ​​the second end face 112. In other words, the end face with the larger area in the roughing insert 100 is referred to as the first end face 111 in this embodiment, and the end face with the smaller area in the roughing insert 100 is referred to as the second end face 112 in this embodiment. The longitudinal section of the roughing insert 100 is trapezoidal; the "longitudinal section" is the plane intercepted by the plane perpendicular to the first end face 111 and the second end face 112.

[0060] The angle formed by the side surface 113 and the height direction is also the clearance angle of the roughing insert 100. By setting a clearance angle of 7°, the rake angle can be reduced when cutting the inner hole, thereby reducing the cutting resistance. Optionally, the height dimension h of the roughing insert 100 provided in this embodiment is 4.76 mm.

[0061] Figure 3 It shows Figure 2 A magnified view of the local structure at point B. Please refer to the diagram. Figures 1-3 In this embodiment, a chamfer structure is provided at the cutting edge 117. The chamfer structure may include a bevel 121, one end of which is connected to the first end face 111, and the other end of which is connected to the side face 113 through a rounded arc 120.

[0062] Optionally, the included angle γ between the inclined surface 121 and the plane containing the first end face 111 is 35°, the radius r2 of the rounded arc 120 is 0.04 mm, and the distance l between the intersection point of the inclined surface 121 and the side surface 113 and the edge of the first end face 111 on the plane containing the first end face 111 is 0.2 mm. This chamfering structure can meet the following roughing requirements. It should be understood that in some other embodiments, other chamfering structures that meet the roughing requirements can also be used. In the presence of the rounded arc 120, the "intersection point of the inclined surface 121 and the side surface 113" mentioned in this description refers to the intersection point formed by the extension line of the inclined surface 121 and the extension line of the side surface 113.

[0063] Embodiments of the present invention also provide a roughing cutting method for roughing a part to be cut, so as to... Figure 4 Taking the structure of the gear part shown as an example, the part to be cut has an end face hardened layer 314 and a cylindrical surface hardened layer 315. The roughing cutting method provided by the present invention can be implemented based on the above-mentioned roughing cutting insert 100. It uses different parts of the same roughing cutting insert 100 to perform roughing cutting on the end face hardened layer 314 and the cylindrical surface hardened layer 315. On the one hand, it helps to extend the service life of the roughing cutting insert 100. On the other hand, since there is no need to change tools between two roughing cutting operations, it can speed up the cycle time and improve the machining efficiency.

[0064] It should be noted that the roughing insert 100 described above is applied to hard turning in the roughing cutting method provided in the embodiments of the present invention. It can be understood that in other embodiment scenarios, the roughing insert 100 can also be applied to soft turning.

[0065] The following example of rough machining of different types of gear parts will be used to further illustrate the rough machining method provided by the present invention. In the following embodiments, the roughing inserts 100 used are all the roughing inserts 100 described above.

[0066] Example 1

[0067] Figure 5 This is a schematic diagram of the structure during rough machining of the end face hardened layer 314 of the first type of gear part 311. Figure 6 This is a schematic diagram of the structure during rough machining of the hardened cylindrical surface layer 315 of the first type of gear part 311. Figure 5 and Figure 6 Only a portion of the first type of gear part 311 is shown in the image. Please refer to the reference section. Figures 4-6In this embodiment, the first gear part 311 has both an end face hardening layer 314 and a cylindrical surface hardening layer 315, the cylindrical surface hardening layer 315 being an inner hole hardening layer. The end face hardening layer 314 has no steps on either side, and the inner hole hardening layer also has no steps on either side, and the inner hole hardening layer is continuous.

[0068] When performing rough machining on the first type of gear part 311 mentioned above, the rough machining method includes:

[0069] S11: Rough machining of the end face hardening layer 314.

[0070] The roughing insert 100 has adjacent first cutting edges 118 and second cutting edges 119, and the included angle between the first cutting edges 118 and the second cutting edges 119 is 95°. The tool body 200 clamps the roughing insert 100, and after clamping, the length direction of the first cutting edge 118 is parallel to the end face hardened layer 314, controlling the roughing insert 100 to feed along the thickness direction of the end face hardened layer 314, i.e. Figure 5 As indicated by the middle arrow, from bottom to top, the first cutting edge 118 extends horizontally. Machining is performed using the cutting edge 117. Compared to cutting with the tool tip 116, more insert material participates in the cutting for the same amount of material removed. As a result, the wear of the roughing insert 100 per unit length is less, thereby extending the life of the roughing insert 100.

[0071] S12: Rough machining of the cylindrical surface hardened layer 315.

[0072] After performing step S11, without changing the tool, the hardened layer of the inner hole is rough machined directly through the same roughing insert 100 and clamping position.

[0073] During rough machining of the hardened layer of the inner hole, the roughing insert 100 is controlled to feed axially along the hardened layer, and the hardened layer is cut by the second cutting edge 119. Specifically, the feed direction of the roughing insert 100 is as follows: Figure 6 As indicated by the middle arrow pointing upwards, during the cutting process, the principal cutting edge angle θ1 of the second cutting edge 119 naturally reaches 5°, and the entire second cutting edge can participate in the cutting. It should be noted that, in the description of this embodiment, "the roughing insert 100 feeds along the axial direction of the hardened inner hole layer" means that the feed direction of the roughing insert 100 is parallel to the axial direction of the hardened inner hole layer.

[0074] By using the cutting edge 117 for machining, compared to cutting with the tool tip 116, more insert material participates in the cutting for the same amount of material removed. This results in less wear per unit length of the roughing insert 100, thus extending its life. Using a small lead angle for cutting, compared to cutting with the tool tip 116, allows for a faster feed rate and a quicker machining cycle when cutting the same thickness of chips.

[0075] Furthermore, since the same roughing insert 100 is used in steps S11 and S12, there is no need to change the tool during the cutting process, which can reduce the cycle time. Moreover, the first cutting edge 118 and the second cutting edge 119, which are different parts of the same roughing insert 100, are used in steps S11 and S12 respectively, which can effectively ensure the service life of the roughing insert 100.

[0076] It should be noted that the execution order of steps S11 and S12 is not limited. In some other embodiments, steps S12 can be executed first and then steps S11 can be executed according to processing requirements.

[0077] Example 2

[0078] Figure 7 This is a schematic diagram of the structure during rough machining of the end face hardened layer 314 of the second type of gear part 312. Figure 8 This is a schematic diagram of the structure during rough machining of the hardened cylindrical surface layer 315 of the second type of gear part 312. Figure 7 and Figure 8 Only a portion of the second type of gear part 312 is shown in the image; the overall structure of the second type of gear part 312 is as follows. Figure 4 As shown. Please refer to the reference. Figure 7 and Figure 8 In this embodiment, the second gear part 312 has both an end face hardening layer 314 and a cylindrical surface hardening layer 315, the cylindrical surface hardening layer 315 being an inner hole hardening layer. The end face hardening layer 314 has no steps on either side, while the inner hole hardening layer has a step 316 on one side, and the inner hole hardening layer is continuous.

[0079] When performing rough machining on the second type of gear part 312 mentioned above, the rough machining method includes:

[0080] S21: Rough machining of the end face hardening layer 314.

[0081] The roughing insert 100 has adjacent first cutting edges 118 and second cutting edges 119, and the included angle between the first cutting edges 118 and the second cutting edges 119 is 85°. A tool tip 116 is formed between the first cutting edges 118 and the second cutting edges 119. The tool body 200 clamps the roughing insert 100, and after clamping, the length direction of the first cutting edge 118 is parallel to the end face hardened layer 314. The roughing insert 100 is controlled to feed along the thickness direction of the end face hardened layer 314, i.e. Figure 7 As indicated by the middle arrow, from bottom to top, the first cutting edge 118 extends horizontally. Machining is performed using the cutting edge 117. Compared to cutting with the tool tip 116, more insert material participates in the cutting for the same amount of material removed. As a result, the wear of the roughing insert 100 per unit length is less, thereby extending the life of the roughing insert 100.

[0082] S22: Rough machining of the cylindrical surface hardened layer 315.

[0083] After performing step S21, without changing the tool, the hardened layer of the inner hole is rough machined directly through the same roughing insert 100 and clamping position.

[0084] During rough machining of the hardened layer of the inner hole, the roughing insert 100 is controlled to feed axially along the hardened layer, and the cutting edge 116 cuts the hardened layer. Specifically, the feed direction of the roughing insert 100 is as follows: Figure 8 As indicated by the middle arrow, moving from bottom to top, the principal cutting edge angle θ2 of the tool tip 116 naturally reaches 5° during the cutting process. It should be noted that, in the description of this embodiment, "the roughing insert 100 feeds along the axial direction of the hardened inner hole layer" means that the feed direction of the roughing insert 100 is parallel to the axial direction of the hardened inner hole layer.

[0085] Since the tool tip 116 does not participate in the cutting process of step S21, there is no need to change the tool and step S22 can be executed directly after step S21, thereby reducing the cycle time. Moreover, the execution of steps S21 and S22 uses the first cutting edge 118 and the tool tip 116 respectively, that is, different parts of the same roughing insert 100, which can effectively ensure the service life of the roughing insert 100.

[0086] It should be noted that the execution order of steps S21 and S22 is not limited. In some other embodiments, step S22 can be executed first and then step S21, depending on the processing requirements. Also, in this embodiment, the position of the roughing insert 100 held by the tool body 200 is different from the position of the roughing insert 100 held by the tool body 200 in Embodiment 1.

[0087] Example 3

[0088] Figure 9This is a schematic diagram illustrating the structure during rough machining of the end face hardened layer 314 and the cylindrical surface hardened layer 315 of the third type of gear part 313. Please refer to... Figure 9 In this embodiment, the third gear part 313 has both an end face hardening layer 314 and a cylindrical surface hardening layer 315, the cylindrical surface hardening layer 315 being an outer circle hardening layer. The end face hardening layer 314 has a step 316 on one side, while the outer circle hardening layer has no steps on either side, and the outer circle hardening layer is discontinuous.

[0089] When performing rough machining on the third type of gear part 313 mentioned above, the rough machining method includes:

[0090] S31: Rough machining of the end face hardening layer 314.

[0091] The roughing insert 100 has a tool tip 116 and a second cutting edge 119. The tool body 200 holds the roughing insert 100 and controls the roughing insert 100 to feed from the side of the end face hardened layer 314 without a step to the side with a step 316, i.e. Figure 9 The direction from left to right is indicated by arrow F1 on the left side of the middle section. The hardened layer 314 on the end face is cut by the tool tip 116.

[0092] S32: Rough machining of the cylindrical surface hardened layer 315.

[0093] After performing step S31, without changing the tool, the outer diameter hardened layer is rough machined directly using the same roughing insert 100 and clamping position.

[0094] When roughing the hardened layer on the outer diameter, the roughing insert 100 is controlled to feed axially along the hardened layer on the outer diameter, i.e. Figure 9 As indicated by arrow F2 on the left, the cutting proceeds from bottom to top, and the outer circle hardened layer is cut through the second cutting edge 119. Since the outer circle hardened layer is a discontinuous outer circle, it is a discontinuous machining process with large impact forces and high cutting resistance. Therefore, only a portion of the second cutting edge 119 is used for cutting, thereby reducing the cutting resistance.

[0095] Optionally, during the cutting process, the principal cutting edge angle θ3 of the second cutting edge 119 is 8°, so that only 2 / 3 of the second cutting edge 119 participates in cutting when step S32 is executed. Using the cutting edge 117 for machining, compared to the traditional method of using the tool tip 116, results in more material participating in the cutting of the same allowance using the small principal cutting edge angle, less wear per unit length of the roughing tool 100, and a longer tool life. Furthermore, using a small principal cutting edge angle allows for a faster cutting feed compared to the traditional method of using the tool tip 116, resulting in a faster machining cycle time for cutting the same thickness of chips.

[0096] Since there is no need to change the tool after step S31, and step S32 can be performed directly, the principal cutting edge angle θ4 of the tool tip 116 is also set to 8° during the execution of step S31.

[0097] Since the tool tip 116 does not participate in the cutting process of step S31, there is no need to change the tool and step S32 can be executed directly after step S31, thereby reducing the cycle time. Moreover, the execution of steps S31 and S32 uses the tool tip 116 and the second cutting edge 119, that is, different parts of the same roughing insert 100, which can effectively ensure the service life of the roughing insert 100.

[0098] It should be noted that the execution order of steps S31 and S32 is not limited. In some other embodiments, step S32 can be executed first, followed by step S31, depending on the processing requirements. It should also be noted that although... Figure 9 The document shows the structure for executing steps S31 and S32, but it does not indicate or imply that steps S31 and S32 are performed simultaneously. In essence, steps S31 and S32 must be performed sequentially. Figure 9 The diagram only illustrates the structure during the execution of steps S31 and S32 for convenience.

[0099] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A roughing cutting method, which uses a roughing cutting tool to rough machine the part to be cut; The roughing insert has a first cutting edge, a second cutting edge, and a tool tip; in, The roughing insert has a first end face and a second end face disposed opposite to each other, and a side surface located between the first end face and the second end face; the side surface includes a plurality of side planes and a side arc surface connecting adjacent side planes, the intersection of the side arc surface and the first end face forms a cutting tip, and the intersection of the side plane and the first end face forms a cutting edge, both the cutting tip and the cutting edge can be used for roughing; two adjacent cutting edges form a set of cutting edges, and at least one set of cutting edges has an included angle of 85°; The part to be cut has an end face hardening layer and a cylindrical surface hardening layer; The roughing cutting method includes: The hardened layer on the end face is rough-machined; The hardened layer on the cylindrical surface is rough-machined using the same roughing tool. In this process, no tool change is performed between two roughing operations; the end face hardened layer is roughed using one of the first cutting edge, the second cutting edge, and the tool tip, and the cylindrical surface hardened layer is roughed using the other of the first cutting edge, the second cutting edge, and the tool tip. If there are no steps on either side of the end face hardened layer, the roughing insert is controlled to feed along the thickness direction of the end face hardened layer and cut the end face hardened layer through the first cutting edge. During the feeding process, the length direction of the first cutting edge is parallel to the end face hardened layer. If there is a step on one side of the end face hardened layer, the roughing insert is controlled to feed in a direction from the side of the end face hardened layer without a step to the side with a step, and cut the end face hardened layer through the cutting tip. If the cylindrical surface hardened layer is continuous and there are no steps on either side of the cylindrical surface hardened layer, then the roughing insert is controlled to feed along the axial direction of the cylindrical surface hardened layer and cut the cylindrical surface hardened layer through the second cutting edge, wherein the principal cutting edge angle of the second cutting edge is 5° during the cutting process; if the cylindrical surface hardened layer is continuous and there is a step on one side of the cylindrical surface hardened layer, then the roughing insert is controlled to feed in a direction from the side of the cylindrical surface hardened layer without a step to the side with a step, and cut the cylindrical surface hardened layer through the tool tip, wherein the principal cutting edge angle of the tool tip is 5° during the cutting process.

2. The roughing cutting method according to claim 1, characterized in that: The roughing cutting tool is made of integral CBN material.

3. The roughing cutting method according to claim 1, characterized in that: The roughing insert has a height direction pointing from the first end face to the second end face, the angle between the side face and the height direction is 7°, and the cross-sectional area of ​​the roughing insert gradually decreases along the height direction.

4. The roughing cutting method according to claim 1, characterized in that: The cutting edge is provided with a chamfer structure, which includes an inclined surface. One end of the inclined surface is connected to the first end face, and the other end of the inclined surface is connected to the side surface through a rounded arc. The angle formed between the inclined surface and the plane containing the first end face is 35°. The radius of the rounded arc is 0.04 mm. The distance between the intersection point of the inclined surface and the side surface and the edge of the first end face on the plane containing the first end face is 0.2 mm.

5. The roughing cutting method according to claim 1, characterized in that: The radius of the arc of the blade tip is 1.6 mm.

6. The roughing cutting method according to claim 1, characterized in that: If the hardened cylindrical surface layer is discontinuous and there are no steps on either side of the hardened cylindrical surface layer, the rough machining steps for the hardened cylindrical surface layer include: The roughing insert is controlled to feed along the axial direction of the cylindrical surface hardened layer, and the cylindrical surface hardened layer is cut by the second cutting edge; During the cutting process, the second cutting edge only partially participates in the cutting. The principal cutting edge angle of the second cutting edge is 8°.

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