Turning method for metal cutting
By using a connecting turning tool in CNC turning, alternating cutting in different directions is achieved, solving the problem of long indexing time for multiple tools and improving machining efficiency and the ability to machine complex shapes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SANDVIK COROMANT
- Filing Date
- 2021-11-03
- Publication Date
- 2026-05-12
AI Technical Summary
In existing CNC turning methods, the tool indexing time is long, making it impossible to efficiently process complex shapes. Furthermore, multiple tools are required, leading to increased downtime and low processing efficiency.
A turning method is employed, using a turning tool including a connecting part, by moving the turning tool in different directions, so that the first cutting element and the second cutting element alternate cutting, reducing or avoiding the rotation of the turning tool around the central axis, and achieving the machining of complex shapes using a single turning tool.
It reduces the tool indexing time, improves machining efficiency, and enables the machining of complex shapes with a single tool. It is suitable for a wide range of CNC lathes, especially lathes without a central axis of rotation.
Smart Images
Figure CN116457125B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of metal cutting. More specifically, this invention belongs to the field of turning. Background Technology
[0002] This invention relates to a turning method for metal cutting. In other words, this invention relates to a turning method for a CNC lathe.
[0003] Turning is a common operation in metal cutting. It is typically performed using CNC lathes. Usually, complex shapes are machined from metal workpieces. To achieve complex shapes, two or more turning tools are often used, with different geometries or orientations. For example, one turning tool may be suitable for machining in one direction, while a second turning tool may be suitable for machining in a different direction.
[0004] Typically, each turning tool is equipped with one cutting insert. After turning with one cutting insert, the first turning tool is usually indexed to a second turning tool. For example, a CNC lathe may include a turret, and indexing from one turning tool to a second turning tool is achieved by rotating the turret by a predetermined angle. The time required for indexing via turret rotation depends on, for example, the CNC lathe. The time without cutting can be called downtime, such as the time spent changing from one tool to or indexing to another.
[0005] EP 1 317 981 A1 discloses a cutting tool carrying multiple turning inserts, thereby enabling rapid switching between different turning inserts by rotating the turning tool around a connecting axis.
[0006] The inventors have discovered a need for further improvements to the turning method. Summary of the Invention
[0007] One object of the present invention is to provide an improved turning method, particularly a turning method in which at least two cutting elements are used one after another, thereby reducing downtime. A further object is to provide a method applicable to a wide range of CNC lathes, particularly CNC lathes in which the turning tool cannot rotate about its central axis. Yet another object is to provide a method in which complex shapes can be machined more efficiently. Another object is to reduce the number of turning tools, achieved by using only one turning tool instead of two or more. Yet another object is to improve the method of machining parts with complex shapes using a single turning tool.
[0008] At least one of the stated objectives is achieved by a turning method for a CNC lathe, the method comprising the steps of: providing a metal workpiece; providing a turning tool, wherein the turning tool includes a connecting portion extending along a connecting axis, wherein the turning tool includes a first cutting element and a second cutting element, wherein the first cutting element includes a first cutting edge, and wherein the second cutting element includes a second tip cutting edge separating and connecting a second forward cutting edge and a second backward cutting edge; rotating the metal workpiece about its axis of rotation in one direction; moving the turning tool in the first direction such that the first cutting edge is in a cutting state; moving the turning tool in one direction such that the first cutting edge moves away from the metal workpiece and the second tip cutting edge moves towards the metal workpiece; moving the turning tool in a second direction such that the second forward cutting edge is in a cutting state with a second entry angle of 5-45°, wherein the second direction is the opposite or substantially opposite direction to the first direction.
[0009] This turning method is used on CNC lathes, i.e., computer-controlled or computerized numerically controlled lathes, that is, any CNC machine tool suitable for turning, such as turning lathes, multi-tasking machine tools, milling and turning machines, or sliding head machine tools. A metal workpiece is provided. The metal workpiece includes an outer surface, which is a radial outer surface. This radial outer surface faces away from the axis of rotation. This turning method is used to turn this radial outer surface, i.e., for external turning. The metal workpiece extends between a first end and a second end. The metal workpiece is held by a clamping device. The clamping device holds the metal workpiece and is at least partially controlled and driven by a motor or spindle.
[0010] The clamping device can be in the form of a chuck, a face driver, or a three-jaw chuck, and may include a tailstock. The headstock end of the machine is preferably located at the first end of the metal workpiece. The second end of the metal workpiece is opposite to the first end and may be a free end. Alternatively, the second end contacts the tailstock or a second chuck.
[0011] A turning tool is provided. The turning tool includes a front end and an opposite rear end, the rear end being in the form of a connecting portion. The connecting portion is connected to a CNC lathe, and more specifically to a machine interface of the CNC lathe, such as a connection to a machine spindle or tool turret or tool holder.
[0012] The cross-section of the connecting portion can be square or rectangular. The connecting portion can be tapered or substantially tapered, such as preferably according to ISO standard 26623-1. In this case, the truncated cone is a cone-like shape. In this case, the tapered portion forms the rear portion of the connector according to ISO standard 26623-1 and is a cone-like shape. The connecting portion is preferably tapered such that the shape of the cone or the cone-like shape is symmetrical or substantially symmetrical about the connecting axis. In this case, triple symmetry is considered symmetrical. Preferably, the cross-sectional area of the cone or the cone-like shape decreases in the rearward direction. The connecting portion can take the form of a hollow tapered shank, such as HSK according to DIN 69893.
[0013] The connecting portion extends along the connecting axis or central axis, which defines the longitudinal axis of the turning tool. The length of the turning tool, measured along or parallel to the connecting axis (i.e., the total length), is preferably 50-400 mm, and even more preferably 70-300 mm.
[0014] A turning tool includes a first cutting element and a second cutting element. The first and second cutting elements are separate. The first and second cutting elements are preferably cutting inserts or turning inserts, i.e., replaceable elements made of a wear-resistant material (e.g., cemented carbide). Alternatively, the first and second cutting elements may be part of a single wear-resistant element, which is preferably made of a single piece of cemented carbide. The first cutting element includes a first top surface. The first top surface includes a rake face or a front face.
[0015] The first cutting element includes a first cutting edge. The first cutting edge can preferably be in the form of a tool-tip cutting edge, i.e., the cutting edge is convex in a top view. The first cutting edge or a portion of the first cutting edge creates a machined surface. The first cutting element can be in the form of a rounded cutting insert, i.e., the insert is circular or substantially circular in a top view. The radius of the circle is preferably 5-30 mm. Alternatively, the first cutting edge can be a tool-tip cutting edge that is convex in a top view, preferably in the form of an arc with a radius of curvature of 0.2-1.6 mm, and is arranged between a first forward cutting edge (i.e., the primary cutting edge or main cutting edge or front cutting edge) and a first backward cutting edge (i.e., the auxiliary cutting edge or tail cutting edge), i.e., connecting the first forward cutting edge and the first backward cutting edge.
[0016] The second cutting element includes a second tip cutting edge that separates and connects a second forward cutting edge and a second backward cutting edge. The second cutting element includes a first top surface. The second top surface includes a rake face or a front face. The second forward cutting edge is a front cutting edge. The second backward cutting edge is a tail cutting edge.
[0017] The first top surface can be rhomboid, triangular, octagonal, square, circular, or polygonal in a top view.
[0018] The first and second top surfaces may each be flat. Alternatively, one or both surfaces may be uneven or non-planar. Preferably, the surfaces may include one or more chip-breaking devices in the form of one or more protrusions and / or recesses.
[0019] The direction facing the first top surface is the normal to the first top surface, i.e., the direction perpendicular to the first top surface. If the first cutting element is in the form of a cutting insert or turning insert with a first bottom surface, then the direction is away from the first top surface and away from the first bottom surface.
[0020] In cases where the first top surface is not flat, to determine the direction in which the first top surface faces, such a first top surface can be defined as or approximately as a plane parallel to the first intermediate plane, wherein the plane intersects the first cutting edge or at least a portion of the first cutting edge. If the first cutting element is in the form of a cutting insert or turning insert having a first bottom surface, then the first intermediate plane is the plane intermediate between the first top surface and the first bottom surface.
[0021] Alternatively, in order to determine the orientation of the first top surface, the first top surface can be defined as a plane that intersects with all cutting edges of the tool tip that border or are adjacent to the first top surface.
[0022] The corresponding reasoning applies to the second top surface and the second cutting element.
[0023] The method includes the step of rotating a metal workpiece about its axis of rotation in one direction. This direction can be clockwise or counterclockwise.
[0024] The method includes the step of moving the turning tool in a first direction, i.e., a first feed direction. In other words, the method includes a turning step in a first direction.
[0025] The first direction can preferably be parallel to the axis of rotation, also known as longitudinal turning. The step is included in a first pass, defined as the movement between entering and exiting the cutting direction. The first pass is not necessarily the movement of the first cutting element along a straight line. When turning in the first direction, the first cutting edge is in a cutting state, i.e., in an active state. The machined surface is formed by the first cutting edge.
[0026] After exiting cutting or during cutting, the turning tool is moved such that the first cutting edge moves away from the metal workpiece and the second cutting edge moves towards the metal workpiece. During at least a portion of this movement, neither the first nor the second cutting element is active; that is, neither the first nor the second cutting element performs metal cutting during this period.
[0027] The movement of the turning tool can be performed in a direction perpendicular to both the connecting axis and the rotation axis. The movement of the turning tool can preferably be linear or include linear movement. The movement is preferably performed without rotation about the connecting axis. Therefore, this method can be applied to a wide range of CNC lathes. The movement can be performed in a direction perpendicular or substantially perpendicular to the first top surface.
[0028] The movement is an indexing motion. In other words, the movement places the first cutting element in an inactive position and places the second cutting element in an active position, i.e., a position in which the second element is adapted to cut metal from the metal workpiece.
[0029] The method includes the step of moving the turning tool in a second direction. In other words, turning is performed in a second direction. The second direction, or second feed direction, is the opposite or substantially opposite direction to the first direction. For example, the first and second directions can be parallel to the axis of rotation but opposite in direction. For example, the first direction can be a direction away from a first end of the workpiece, while the second direction can be towards the first end of the workpiece. The first end can be the clamping end, i.e., the end of the workpiece clamped by a clamping device. The step of moving the turning tool in the second direction is included in a second pass, which defines the second pass between entering and exiting the cutting process. The second pass is not necessarily a linear movement of the first cutting element. The machined surface is formed by a second cutting edge. The second cutting edge and the second forward cutting edge function such that the second forward cutting edge functions with an acute second entry angle. The acute second entry angle is preferably 5-45°, and even more preferably 5-30°. Compared to a larger second entry angle, the cutting tool wear of the second cutting element is reduced by such an acute entry angle. The second entry angle is the entry angle of the second forward cutting edge when the turning tool moves in the second direction.
[0030] When the turning tool is moved in the first direction, the second cutting element is inactive, i.e., no cutting occurs; in other words, it separates from the metal workpiece. When the turning tool is moved in the second direction, the first cutting element is inactive, i.e., no cutting occurs; in other words, it separates from the metal workpiece.
[0031] Preferably, no part of the turning tool is located between the first cutting edge and the second cutting edge. In other words, preferably, no part of the turning tool is located on the straight line connecting the first and second cutting edges.
[0032] According to one embodiment, the first cutting element includes a first forward cutting edge and a first backward cutting edge, wherein the first cutting edge is a first tip cutting edge, wherein the first tip cutting edge separates the first forward cutting edge from the first backward cutting edge and connects the first forward cutting edge and the first backward cutting edge, wherein when the turning tool is moved in a first direction, the first forward cutting edge forms a first entry angle of 5-45°.
[0033] In this way, the wear of the first cutting element is reduced compared to the case where the first entry angle is larger.
[0034] The first forward cutting edge is the main cutting edge or primary cutting edge, and the first backward cutting edge is the auxiliary cutting edge. Preferably, the first forward cutting edge and the first backward cutting edge are both straight or linear, or substantially straight or substantially linear, in the top view. The first tool tip cutting edge is convex in the top view, preferably in the form of an arc, and preferably has a radius of curvature of 0.2-1.6 mm.
[0035] The tip angle of the first cutting element is defined as the angle between the first forward cutting edge and the first backward cutting edge, and the tip angle is preferably less than or equal to 160°, or even more preferably 30°-80°.
[0036] The first forward cutting edge forms an acute angle, the first entry angle being 5-45°, or even more preferably 5-30°.
[0037] When the turning tool is moved in the first direction, the first cutting edge at the tip and the first forward cutting edge are in a cutting or active state.
[0038] When turning is performed in the first direction and the second direction, the first cutting edge and the second cutting edge are preferably spaced at a constant distance along the axis of rotation.
[0039] According to one embodiment, the method includes an additional step: moving the turning tool in a second direction such that the second rearward cutting edge forms an obtuse back clearance angle.
[0040] In this method, the second cutting element can machine surfaces perpendicular to the axis of rotation. The method may include the step of moving a hard disk turning tool radially toward the axis of rotation, thereby placing the second cutting element in a cutting state. Preferably, this step precedes the step of moving the turning tool along a second direction.
[0041] Preferably, the clearance angle is 91°-135°, more preferably 93°-120°. The sum of the entry angle, the tool tip angle, and the clearance angle is equal to 180°. This applies to both the first and second cutting elements.
[0042] According to one embodiment, the method includes the step of moving a turning tool in a first direction such that a first rearward cutting edge forms an obtuse back clearance angle.
[0043] In this method, the first cutting element can machine a surface perpendicular to the axis of rotation. The method may include the step of moving a turning tool radially toward the axis of rotation, thereby placing the first cutting element in a cutting state. Preferably, this step precedes the step of moving the turning tool along a first direction.
[0044] Preferably, the rear clearance angle is at least 91°, and even more preferably 93°-120°.
[0045] According to one embodiment, the method includes the step of turning at least a portion of a surface machined when the turning tool is moved in a second direction.
[0046] In this way, roughing and finishing operations can be performed using only one turning tool.
[0047] The method may include another step: moving the turning tool in a first direction such that the first cutting element is in a cutting state, and causing at least a portion of the surface being machined when the turning tool is moved in a second direction.
[0048] The method may include another step in which a first cutting element and a second cutting element are alternately in a cutting state, wherein the first cutting element is in a cutting state when the turning tool moves in a first direction, and the second cutting element is in a cutting state when the turning tool moves in a second direction.
[0049] According to one embodiment, the step of moving the turning tool in one direction so that the first cutting edge moves away from the metal workpiece and the second cutting edge moves toward the metal workpiece is performed without rotating the turning tool about the connecting center axis.
[0050] The movement is performed without the turning tool rotating around the connecting axis or any other axis parallel to the connecting axis. In this way, the method can be applied to a wide range of CNC machine tools. The movement can be linear, or the turning tool can move non-linearly in a plane defined by the two machine axes (such as the XZ plane of a CNC lathe), for example, in an arc. Thus, the indexing time can be shorter compared to rotary movement. Another effect of linear movement is that the method can be performed using CNC lathes without rotary options.
[0051] Preferably, the turning tool does not rotate about the connecting axis during the first pass, the second pass, or between the first and second passes. Preferably, during the first and second passes, or between them, the turning tool does not rotate about any other axis (such as any axis parallel to the connecting axis). In other words, the method is preferably performed without any rotational movement of the turning tool.
[0052] According to one embodiment, the connecting axis is parallel to or perpendicular to the axis of rotation.
[0053] This method can be applied to a wider range of CNC lathes. When turning in the first and second directions, it is preferable that the connecting axis is parallel or perpendicular to the axis of rotation throughout all steps of the method.
[0054] According to one embodiment, a metal workpiece is held by a clamping device, wherein the distance from the clamping device to the second cutting edge is shorter than the distance from the clamping device to the first cutting edge.
[0055] The clamping device is connected to and driven by a rotating or rotatable spindle. The clamping device may be, for example, a chuck, a three-jaw chuck, or a face drive. The distance is measured along or parallel to the axis of rotation.
[0056] According to one embodiment, when the turning tool is moved in a first direction, the second cutting edge of the tool tip is located in front of the first cutting edge in the first direction, wherein when the turning tool is moved in a second direction, the first cutting edge is located in front of the second cutting edge of the tool tip in the second direction.
[0057] This method allows for the machining of more shapes because there is a lower risk of interference between inactive cutting elements and the metal workpiece. "Forward" should be understood as the forward direction along the axis of rotation in the feed direction. More specifically, when the turning tool is moved in the first direction, the second cutting edge is in front of the surface-generating portion of the first cutting edge, wherein when the turning tool is moved in the second direction, the surface-generating portion of the first cutting edge is in front of the second cutting edge. The surface-generating portion of the first cutting edge is preferably in the form of the first cutting edge tip.
[0058] According to one embodiment, the second direction is the direction away from the corner of the metal workpiece.
[0059] The corner or shoulder is defined as the intersection between a first surface concentric with the axis of rotation and a second surface perpendicular to the axis of rotation. The first surface can be an outer surface or an inner surface, i.e., a surface within a hole. Preferably, the first surface is an outer surface, i.e., a radially outer surface. The corner is preferably a 90° corner. The corner is preferably formed wholly or at least partially by a second cutting element.
[0060] According to one embodiment, the method includes an additional step: turning in a third direction such that the second forward cutting edge is in operation at an obtuse third entry angle, wherein the third direction is oriented toward the axis of rotation.
[0061] In this way, more complex part shapes can be machined using a single turning tool. The third-up turning step preferably follows turning in the first direction. The third-up turning step is preferably performed before turning in the second direction. The third-up turning step is preferably part of the second feed, such that the second cutting element is continuously in a cutting or active state while turning in the third and second directions. Therefore, the second feed is preferably non-linear. The third approach angle is preferably at least 100°, more preferably at least 110°. The third direction is preferably perpendicular to and towards the axis of rotation. During third-up turning, the second tool tip cutting edge forms a surface.
[0062] Preferably, the outer corner or outer shoulder is formed by turning in a third and a second direction. The outer corner is formed by two surfaces, one of which is cylindrical or conical, and the other is flat or conical. The two surfaces are connected by a curved surface.
[0063] Preferably, the corner or shoulder is defined by a first surface concentric with the axis of rotation and a second surface perpendicular to the axis of rotation. The first surface can be an external surface or an internal surface, i.e., a surface within the hole. Preferably, the first surface is an external surface, i.e., a radially external surface. The first and second surfaces are connected by a curved surface. Preferably, when viewed in a plane including the axis of rotation, the curved surface is in the form of an arc. The radius of the arc is greater than or equal to the radius of the second cutting edge.
[0064] The first direction is preferably toward the corner (i.e., the corner). In other words, the first pass is in the direction toward the corner to be formed, preferably the corner that is formed after the second pass. Therefore, the first pass includes roughing the corner, i.e., removing some but not all of the material to obtain the desired or predetermined shape.
[0065] According to one embodiment, the first cutting element is a first turning insert, and the second cutting element is a second turning insert. The first turning insert includes a first top surface and a first bottom surface, wherein the first top surface and the first bottom surface are connected by a first side surface. The second turning insert includes a second top surface and a second bottom surface, wherein the second top surface and the second bottom surface are connected by a second side surface. The first top surface and the second top surface include chip breaking devices.
[0066] The first turning insert includes a first cutting edge, a first forward cutting edge, and a first backward cutting edge. The second turning insert includes a second tip cutting edge, a second forward cutting edge, and a second backward cutting edge.
[0067] The first top surface includes a rake face. The second top surface includes a rake face. Each of the first and second bottom surfaces includes a mounting surface or a contact surface.
[0068] Preferably, the first through hole for the first screw intersects with the first top surface and the first bottom surface.
[0069] Preferably, the second through hole for the second screw intersects with the second top surface and the first bottom surface.
[0070] The chip breaker can take the form of one or more protrusions and / or recesses. Preferably, the one or more protrusions and / or recesses are arranged to control or break the chips. When viewed in a side view of the insert, the protrusions preferably extend above the cutting edge that contacts the top surface. The chip breaker improves chip breaking in turning.
[0071] According to one embodiment, the cross-section of the connecting portion is square or rectangular, or includes a tapered or substantially tapered portion.
[0072] The cross-section lies in a plane perpendicular to the connecting axis. The connecting portion preferably comprises a tapered or substantially tapered portion and an annular portion, such as preferably in the form of a polygonal hollow tapered interface with a flanged contact surface (such as according to ISO 26623-1:2014), or in the form of a hollow tapered portion with a flanged contact surface (such as according to DIN 69893, ISO 12164-1 or ISO 12164-1F).
[0073] According to one embodiment, the method includes another step: arranging the turning tool such that the metal workpiece is located between a first cutting edge and a second cutting edge.
[0074] In this method, the indexing between the first and second components can be achieved through linear movement along the connecting axis. This method can be used on a large number of CNC lathes. Therefore, during turning in the first direction and during turning in the second direction, the metal workpiece is located between the first cutting edge and the second cutting edge.
[0075] Preferably, the axis of rotation is between the first cutting edge and the second cutting edge, or substantially between the first cutting edge and the second cutting edge. In other words, turning in a first direction using the first cutting element and turning in a second direction using the second cutting element are on opposite sides relative to the axis of rotation of the metal workpiece. Preferably, the rake face associated with the first cutting edge and the rake face associated with the second cutting edge face in opposite or substantially opposite directions.
[0076] According to one aspect of the invention, a computer program having instructions is provided that, when executed by a CNC lathe, causes the CNC lathe to perform the steps according to any of the methods described above.
[0077] The computer program or computer program product may be included in a CAM software product, i.e., software used for computer-aided manufacturing. The computer program may be in the form of a computer-readable medium, such as a USB stick, CD-ROM, or data stream. Attached Figure Description
[0078] The invention will now be explained in more detail through a description of embodiments thereof and with reference to the accompanying drawings.
[0079] Figure 1 This is a perspective view of the turning tool and the metal workpiece according to the first embodiment.
[0080] Figure 2 yes Figure 1 A side view of the turning tool and the metal workpiece.
[0081] Figure 3 yes Figure 1 A schematic bottom view of a turning tool and a metal workpiece.
[0082] Figure 4 yes Figure 1 A portion of the turning tool and another bottom view of the metal workpiece.
[0083] Figure 5 yes Figure 1 A portion of the turning tool and another bottom view of the metal workpiece.
[0084] Figure 6 yes Figure 1 A portion of the turning tool and another bottom view of the metal workpiece.
[0085] Figure 7 This is a side view of a turning tool according to the second embodiment.
[0086] Figure 8 This is a side view of the turning tool and metal workpiece according to the third embodiment.
[0087] Figure 9 This is a perspective view of the turning tool according to the fourth embodiment.
[0088] Figure 10 yes Figure 9 A top view of a turning tool.
[0089] Figure 11 yes Figure 9 Front view of the turning tool in the image.
[0090] Figure 12 yes Figure 9 A side view of a turning tool.
[0091] Figure 13 yes Figure 9 A top view of the turning tool and the metal workpiece.
[0092] Figure 14 yes Figure 9 Another top view of the turning tool and the metal workpiece.
[0093] Figure 15 yes Figure 9 Another top view of the turning tool and the metal workpiece.
[0094] Figure 16 This is a perspective view of the turning tool according to the fifth embodiment.
[0095] Figure 17 yes Figure 16 A side view of a turning tool.
[0096] Figure 18 yes Figure 16 The front view of the turning tool in the image.
[0097] Figure 19 yes Figure 16 A top view of a turning tool.
[0098] Figure 20 yes Figure 19 A magnified view of part B in the image.
[0099] Figure 21 yes Figure 16A top view of the turning tool and the metal workpiece.
[0100] Figure 22 yes Figure 16 A side view of the turning tool and the metal workpiece.
[0101] Figure 23 yes Figure 16 A top view of the turning tool and the metal workpiece.
[0102] Figure 24 This is a schematic diagram showing the movement of a turning tool in the first direction.
[0103] Figure 25 This is a schematic diagram showing the movement of a turning tool in the second direction.
[0104] Figure 26 This is another schematic diagram showing the movement of the turning tool in the second direction.
[0105] Figure 27 It is a schematic cross-sectional view showing the first cutting element, the second cutting element, and the rotating metal workpiece.
[0106] All turning tools in the diagram are drawn to scale. Detailed Implementation
[0107] refer to Figures 1-6 The diagram illustrates a turning tool 1 according to a first embodiment, suitable for performing the methods defined above. A metal workpiece 2 is connected to the spindle (not shown) of a CNC lathe (not shown) via a clamping device (not shown). The turning tool 1 includes a connecting portion 3 extending along a connecting axis A2. The connecting axis A2 defines the longitudinal axis of the turning tool 1. The forward direction moves away from the connecting portion 3, i.e., the forward direction is substantially toward... Figure 1 On the left side of the workpiece. The rotation axis A1 of the metal workpiece 2 is arranged perpendicular to and intersects the connecting axis A2. The turning tool 1 includes a first cutting element 7 in the form of a first turning insert 7 and a second cutting element 8 in the form of a second turning insert 8.
[0108] like Figures 3 to 6 As shown, the first cutting element 7 includes a first cutting edge 5 in the form of a first cutting edge 5, which separates and connects the first forward cutting edge 12 and the first backward cutting edge 14. The second turning insert 8 includes a second cutting edge 6, which separates and connects the second forward cutting edge 13 and the second backward cutting edge 15.
[0109] like Figure 2 As shown, the first turning insert 7 includes a first top surface 20, and the second turning insert 8 includes a second top surface 21. Figure 2 In this process, the metal workpiece 2 rotates clockwise about its axis of rotation A1. The first cutting edge and the second cutting tip intersect or substantially intersect a plane including the connecting axis A2 and the axis of rotation A1. Figure 2 In this process, the first turning insert 7 is in a cutting state, and the second turning insert 8 is only a very small distance away from the metal workpiece 2. Preferably, the distance between the metal workpiece 2 and the inactive second turning insert 8 is larger, such as... Figure 3 and Figure 4 As shown.
[0110] exist Figure 1 and Figure 2 In the machining tool 1, a middle portion 33, in the form of a recessed portion 33 or a curved portion, connects a first cutting insert 7 and a second cutting insert 8. The middle portion 33 includes an opening 41. The opening 41, or cavity, forms a space for the metal workpiece to be machined. The recessed portion 33 is curved about an axis perpendicular to the connecting axis A2, wherein the axis intersects the opening 41, or cavity, or void. For example, in... Figure 2 As can be seen, opening 41 opens radially relative to the axis of rotation A1. At least if the diameter of the metal workpiece 2 is smaller than the distance between the first turning insert 7 and the second turning insert 8, the turning tool 1 can... Figure 2 The top of it was placed as Figure 2 The position shown. In particular, this would be an advantage if the metal workpiece 1 is long or clamped at both ends.
[0111] The intermediate portion 33 includes a first side surface 40 and an opposite second side surface. Due to the opening 41, the first side surface 40 does not surround or enclose the axis of rotation A1. The first side surface 40 extends in a plane perpendicular to the axis of rotation A1. The plane 40 is spaced apart from the connecting axis A2.
[0112] Protrusions 30 and 31 extend from the first side surface 40 and take the form of replaceable cutting heads 30 and 31, which are connected to the first side surface via clamping devices. Each cutting head 30 and 31 includes at least one insert holder. A first turning insert 7 and a second turning insert 8 are connected to the first side surface 40 via corresponding cutting heads 30 and 31.
[0113] exist Figure 2 In this configuration, the rotation axis A1 is perpendicular to and intersects the connecting axis A2. For example... Figure 2 As shown, the rotation axis A2 of the metal workpiece 2 is between the first turning insert 7 and the second turning insert 8. The connecting part 3 includes a tapered section. The connecting part 3 is a quick-change connector, known in the industry as a Coromant. In an alternative embodiment (not shown), the cross-section of the connecting portion 3 is square, and the connecting axis A2 is parallel to... Figure 2 The connecting axis A2 in the middle, and in Figure 2 The connecting axis A2 is 5-20mm below.
[0114] When in a top view (e.g. in) Figure 3 When observing the first turning insert 7, the first tool tip angle, defined as the angle between the first forward cutting edge 12 and the first backward cutting edge 14, is an acute angle.
[0115] When in a top view or bottom view (e.g. in...) Figure 3 When observing the second cutting insert, the second tool tip angle, defined as the angle between the second forward cutting edge 13 and the second backward cutting edge 15, is an acute angle.
[0116] For example Figure 1 As seen, the first through hole for the first screw (not shown) intersects with the first top surface and the first bottom surface, and the second through hole for the second screw (not shown) intersects with the second top surface and the first bottom surface.
[0117] Figure 3 and Figure 4 The first machining step is shown, in which the turning tool 1 moves in a first direction 17 perpendicular to the connecting axis A2. The first forward cutting edge 12 forms an acute first entry angle. The first backward cutting edge 14 forms an obtuse first clearance angle. The first turning insert 7 is in the cutting state. The second turning insert 8 separates from the metal workpiece 2. The second cutting edge 6 is located in front of the first cutting edge 5 in the first direction 17.
[0118] exist Figure 3 , 4 After the steps shown, the first cutting insert 7 exits the cutting process, and the turning tool 1 moves in one direction 19, causing the first cutting edge 5 to move away from the metal workpiece 2, and causing the second cutting edge 6 to move towards the metal workpiece 2, as shown. Figure 5 As shown. The first turning insert 7 moves radially away from the rotation axis A1 of the metal workpiece 2.
[0119] exist Figure 5 After the steps shown, proceed Figure 6 The steps are shown. Figure 6 The diagram shows the movement of the turning tool 1 in a second direction 18, wherein the second direction 18 is as follows: Figure 4 and Figure 5The direction is opposite to the first direction 17 shown. The second cutting insert 8 is in the cutting state. The first cutting insert 7 is not in operation. In other words, the first cutting insert is separated from the metal workpiece 2. The second forward cutting edge 13 forms an acute second entry angle. The second backward cutting edge 15 forms an obtuse second clearance angle.
[0120] exist Figure 3 , Figure 4 and Figure 6 In the middle, the metal workpiece 2 rotates in the same direction around its rotation axis A1.
[0121] Figure 7 A turning tool 1 according to a second embodiment is shown. The only substantial difference between the turning tools 1 according to the first and second embodiments is that the turning tool 1 according to the second embodiment includes a third turning insert 9. Indexing from the first turning insert 7 to the second turning insert 8, or vice versa, is achieved by moving the turning tool 1 along the connecting axis A2, while indexing to the third turning insert 9 is achieved by moving the turning tool in a direction perpendicular to the connecting axis A2 (more specifically, in…). Figure 2 This is achieved by moving upwards (from the middle down). For example... Figure 7 As shown, the first turning insert 7, the second turning insert 8, and the third turning insert 9 intersect with an imaginary circle or cylinder C1, which has a central axis A3 perpendicular to the connecting axis A2. The first turning insert 7 is inclined at an angle ω relative to the second turning insert 8. The angle ω is measured about the central axis A3 of the imaginary circle C1. The second top surface 21 faces a direction perpendicular to the connecting axis A2 and perpendicular or substantially perpendicular to the central axis A3 of the imaginary circle or cylinder C1.
[0122] Figure 8 A turning tool 1 and a metal workpiece 2 according to a third embodiment are shown. The only substantial difference between the turning tool 1 according to the second and third embodiments is that the turning tool 1 according to the third embodiment includes a fourth turning insert 10, and an intermediate portion 33 surrounds the axis of rotation A1. In other words, the intermediate portion does not include a radial opening.
[0123] Now for reference Figures 9 to 15 The diagram illustrates a turning tool 1 according to a fourth embodiment. The turning tool 1 includes a connecting portion 3. The connecting portion 3 extends along a connecting axis A2, which defines the longitudinal axis of the turning tool 1. The connecting portion defines the rear end of the turning tool 1. The turning tool 1 includes a first cutting element 7 in the form of a first turning insert 7 and a second cutting element 8 in the form of a second turning insert 8. For example... Figure 10As seen, the first turning insert 7 includes a first forward cutting edge 12, a first backward cutting edge 14, and a first tip cutting edge 5. The first tip cutting edge 5 is the portion of the first turning insert 7 closest to the connecting axis A2. The second turning insert 8 includes a second tip cutting edge 6, a second forward cutting edge 13, and a second backward cutting edge 15. The first tip angle, defined as the angle between the first forward cutting edge 12 and the first backward cutting edge 14, is an acute angle. The second tip angle, defined as the angle between the second forward cutting edge 13 and the second backward cutting edge 15, is an acute angle. For example, in... Figure 10 As seen, measured along or parallel to the connecting axis A2, the second cutting edge 6 is located in front of the first cutting edge 5. The front is defined as being away from the connecting portion 3 and towards the first turning insert 7 and the second turning insert 8.
[0124] For example Figure 11 As seen, the first turning insert 7 includes a first top surface 20 and an opposite first bottom surface. The second turning insert 8 includes a second top surface 21 and an opposite second bottom surface. The first top surface 20 includes a first rake face, and the second top surface 21 includes a second rake face. Figure 11 As shown, the first cutting insert 7 and the second cutting insert 8 intersect with an imaginary circle or cylinder C1, which has a central axis A3 parallel to the connecting axis A2. The first cutting insert 7 is inclined at an angle ω relative to the second cutting insert 8, wherein the angle ω is measured about the central axis A3 of the imaginary circle C1. The first top surface 20 faces a direction perpendicular to or substantially perpendicular to the connecting axis.
[0125] For example Figure 9 As seen, the turning tool 1 includes a forward-facing surface 42, i.e., a surface facing away from the connecting portion 3. Two elements 30, 31 are in the form of replaceable cutting heads 30, 31, which project forward from the forward-facing surface 42. The first cutting head 30 includes a first turning insert 7, meaning the first cutting head includes an insert holder in which the first turning insert 7 is mounted. The second cutting head 31 includes a second cutting element 8. The cutting heads 30, 31 are spaced apart from the connecting axis A2.
[0126] The connecting portion 3 defines the rear end of the turning tool 1 and is adapted for insertion into a machine interface (not shown), preferably including a cavity or recess (not shown). (Example shown) Figure 9 The connecting portion 3 includes a basic tapered portion, a basic tapered portion, or a tapered portion. This connecting portion is known as a coromant in the field of metal cutting tools. Other types of connecting parts are also possible, such as the known square shank type. For example, if the connecting part is of the square shank type, the cross-section of the connecting part perpendicular to the connecting axis is square or rectangular. Furthermore, for such turning tools, the connecting axis is parallel to... Figure 12 The connecting axis A2 is located 5-20mm below it.
[0127] Figure 13 The first machining step is illustrated. The metal workpiece 2 rotates about its axis of rotation A1 in one direction. The turning tool 1 moves in a first direction 17, which is parallel to the connecting axis A2 and parallel to the axis of rotation A1 of the metal workpiece 2. The first direction 17 is a forward direction, that is, in the direction away from the connecting part 3 and in the direction faced by the face-facing surface 42. Figure 13 In the first turning insert 7, the top surface faces the observer. The machined surface is formed by the first cutting edge 5; in other words, the first cutting edge 5 is a surface-generating cutting edge. The first turning insert 7 is arranged such that the first forward cutting edge 12 forms a first entry angle α of 3-45° acute. The first backward cutting edge 14 forms a first clearance angle γ of 93°-135° obtuse. The second turning insert 8 is separated from the metal workpiece 2. When the turning tool 1 is moved in the first direction 17, the second cutting edge 6 is in front of the first cutting edge 5. Figure 13 As shown, the turning tool 1 is arranged such that the cylindrical metal workpiece 2 is arranged between the first turning insert 7 and the second turning insert 8, wherein the axis of rotation A1 (which is the longitudinal axis A1 of the metal workpiece 2) is located between the turning inserts 7 and 8.
[0128] Figure 14 It shows Figure 13 The steps following the steps shown. The turning tool 1 moves in a direction 19, causing the first cutting edge 5 to move away from the metal workpiece 2 and the second cutting edge 6 to move towards the metal workpiece 2. The turning tool 1 moves in a direction 19 perpendicular to the connecting axis A2 and perpendicular to the rotation axis A1. The movement is linear.
[0129] Figure 15 It shows Figure 14 The steps following the steps shown. The turning tool 18 moves in the second direction 18. The second direction 18 is the opposite direction to the first direction 17. The second forward cutting edge 13 forms a second entry angle β with an acute angle of 3°-45°. The second backward cutting edge 15 forms a second clearance angle δ with an obtuse angle of 93°-135°. The first turning insert 7 separates from the metal workpiece 2. The first cutting edge 5 is located in front of the second cutting edge 6 in the second direction 18. The second turning insert 8 is positioned in front of the second cutting edge 6. Figure 13In the first step shown, at least a portion of the surface processed by the first turning insert 7 is machined.
[0130] Now for reference Figures 16-23 The diagram illustrates a turning tool 1 according to a fifth embodiment. The turning tool 1 includes a connecting portion 3. The connecting portion 3 extends along a connecting axis A2. The connecting axis A2 defines the longitudinal axis of the turning tool 1. The connecting portion 3 includes a tapered or substantially tapered portion. In this example, the substantially tapered portion is based on a known Coromant in the industry. The connecting part can have other shapes, such as a square or rectangular cross-section, wherein the cross-section is perpendicular to the connecting axis.
[0131] The turning tool 1 includes a first cutting element 7 in the form of a first turning insert 7, a second cutting element 8 in the form of a second turning insert 8, and a third cutting element 9 in the form of a third turning insert 9. The first turning insert 7 includes a first cutting edge 5 in the form of a first cutting tip 5, a first forward cutting edge 12, and a first backward cutting edge 14. The first cutting tip 5 separates and connects the first forward cutting edge 12 and the first backward cutting edge 14. The first turning insert 7 includes a first top surface 20 and an opposite first bottom surface. The second turning insert 8 includes a second forward cutting edge 6, a second forward cutting edge 13, and a second backward cutting edge 15. The second cutting tip 6 separates and connects the second forward cutting edge 13 and the second backward cutting edge 15. In other words, the second forward cutting edge 13 and the second backward cutting edge 15 converge toward the second cutting tip 6. The second cutting element 8 includes a second top surface 21 and an opposite second bottom surface.
[0132] The first mid-plane P1 extends at the midpoint or substantially midpoint between the first top surface 20 and the first bottom surface. The first mid-plane P1 is parallel to or substantially parallel to the first bottom surface. Correspondingly, the second turning insert 8 includes a second top surface 21 and an opposite second bottom surface, wherein the second mid-plane P2 extends at the midpoint or substantially midpoint between the second top surface 21 and the second bottom surface. The third turning insert 9 is arranged correspondingly, having a third mid-plane P3 located midpoint between its top and bottom surfaces. The top surfaces 20, 21 are adapted to serve as rake faces. The first mid-plane P1, the second mid-plane P2, and the third mid-plane P3 extend in parallel or substantially parallel planes. For example, Figure 17 As seen, the first top surface 20 and the second top surface 21 face the same or substantially the same direction, which is in Figure 17 The middle is upward.
[0133] like Figure 18As shown, the distance from the connecting axis A2 to the second cutting edge is greater than the distance from the connecting axis A2 to the first cutting edge 5. This distance is... Figure 18 The distance is measured horizontally. In other words, it is the distance from a first plane including the connecting axis, wherein the first plane is perpendicular to the first center plane. Therefore, the distance is the distance from the first plane to the first cutting edge 5 and the second cutting edge 6. In a top view, as... Figure 19 and Figure 20 As shown, Figure 20 yes Figure 19 In the enlarged view of part B, the first bisector between the first forward cutting edge 12 and the first backward cutting edge 14 forms an angle of 45-90° with respect to the second bisector between the second forward cutting edge 13 and the second backward cutting edge 15. It can also be seen that the first backward cutting edge 14 and the second backward cutting edge 15 form an angle of 6-20° with respect to each other. Furthermore, the distance from the first forward cutting edge 12 to the second forward cutting edge 13 is shorter than the distance from the first forward cutting edge 12 to the second backward cutting edge 15. The first tool tip angle defined as the angle between the first forward cutting edge 12 and the first backward cutting edge 14 is an acute angle. The second tool tip angle defined as the angle between the second forward cutting edge 13 and the second backward cutting edge 15 is an acute angle. For example... Figure 19 In the process, the first cutting edge 5 and the second cutting edge 6 are at equal or substantially equal distances in the longitudinal direction. The first cutting edge 5 and / or the second cutting edge 6 are the furthest longitudinal portion of the turning tool 1, wherein the longitudinal direction is defined as along the connecting axis or along an axis parallel to the connecting axis A2.
[0134] exist Figure 20 In the top view, the first turning insert 7 and the second turning insert 8 partially overlap.
[0135] Figure 21 An example of the first step of a turning method for a CNC lathe (not shown) is illustrated. A metal workpiece 2 rotates about its axis of rotation A1 in a direction 50. The connecting portion 3 of the turning tool 1 is connected to the CNC lathe (not shown), more specifically, to a machine interface. The connecting axis A2 is perpendicular to the axis of rotation A1. The turning tool 1 moves in a first direction 17 such that the first cutting edge 5 is in a cutting state, and the first forward cutting edge forms an acute entry angle. The first backward cutting edge 14 forms an obtuse clearance angle. A second cutting insert 8 and a third cutting insert 9 separate from the metal workpiece 2. The second cutting edge is located in front of the first cutting edge 5 in the first direction 17. The first direction is parallel to the axis of rotation A1.
[0136] After the first step, such as Figure 22As shown, the turning tool 1 moves in direction 19, which is perpendicular to the connecting axis A2 and the rotation axis A1. This direction is the same as or substantially the same as the direction facing the first top surface 20. This direction is not radial relative to the rotation axis A1, but tangential relative to the metal workpiece 2. The movement of the turning tool 1 is linear, wherein the first cutting edge moves further away from the metal workpiece 2, and the second cutting edge 6 moves closer to or toward the metal workpiece 2. None of the first cutting insert 7, the second cutting insert 8, or the third cutting insert 9 is in a cutting state.
[0137] Figure 23 It shows in Figure 22 The next step following the steps shown. The turning tool 1 moves in the second direction 18 such that the second forward cutting edge 13 is in a cutting state with an acute second entry angle β, which is 5–45°. The machined surface is formed by the second tip cutting edge 6. The second direction 18 is the opposite or substantially opposite direction to the first direction 17. The second backward cutting edge 15 forms an obtuse clearance angle. The first tip cutting edge is located in front of the second tip cutting edge 6 in the second direction. The first turning insert 7 and the third turning insert 9 separate from the metal workpiece 2. Figure 23 The steps shown involve processing by Figure 21 At least a portion of the machined surface produced by the steps shown.
[0138] Compared to those described above, metal workpieces can have different shapes. Metal workpieces can be bars, hollow bars, or any other shape that has rotational symmetry or substantially rotational symmetry about its axis of rotation. Machinable shapes can have different constructions than those described above. For example, the shape can have not only one sidewall, but also two sidewalls, i.e., surfaces in a plane perpendicular to the axis of rotation. In other words, turning tools can be used to machine external grooves.
[0139] Figure 24 This is a schematic diagram of a turning tool moving in a first direction 17, where the first cutting element 7 is in a cutting state. The first direction 17 is the feed direction. A first forward cutting edge forms a first entry angle α of 5–45°, and a first backward cutting edge forms a back clearance angle γ of at least 91°. The second cutting element 8 is separated from the metal workpiece 2. The machined surface 25 is formed by the first cutting element 7. More specifically, surface 25 is formed by the first tool tip cutting edge 5.
[0140] Figure 25This is a schematic diagram of a turning tool moving in the second direction 18, where the second cutting element 8 is in a cutting state. The second direction is the feed direction. The second forward cutting edge is in the cutting state with a second entry angle β of 5–45°, and the second backward cutting edge forms an obtuse clearance angle δ. At least a portion of the surface 25 machined when the turning tool 1 moves in the first direction 17 (see...) Figure 24 )exist Figure 25 and Figure 26 The material is processed by means of the second cutting element 8.
[0141] Figure 26 This is another schematic diagram of the turning tool moving in the second direction 18, wherein the second cutting element 8 is in the cutting state. The second forward cutting edge is in the cutting state with a second entry angle β of 5–45°, and the second backward cutting edge forms an obtuse clearance angle δ. The second bottom surface faces the observer.
[0142] Figure 24 The first processing step is shown, which may be followed by... Figure 25 or Figure 26 The steps shown. If the turning tool is the turning tool according to the fifth embodiment, then apply... Figure 25 The steps shown are followed, and if the turning tool is a turning tool according to the first, second, third, or fourth embodiment, then the application... Figure 26 The steps are shown. In Figure 25 In the middle, the second cutting element 8 is located at the intersection of the rotation axis A1 and the... Figure 24 On the same side of the first cutting element 7, and the first top surface and the second top surface face the same direction. Conversely, in Figure 26 In the middle, the second cutting element 8 is located at the intersection of the rotation axis A1 and the... Figure 24 The first cutting element 7 is on the opposite side, and the first top surface faces the opposite direction of the second top surface.
[0143] Figures 24-26 The metal workpiece 2 is held at one end by a clamping device 60. The clamping device 60 is connected to and driven by a rotating or rotatable spindle (not shown), which is part of a CNC lathe (not shown). The clamping device can be, for example, a chuck, a three-jaw chuck, or an end-face drive. The distance from the clamping device 60 to the second cutting edge 6 is shorter than the distance from the clamping device 60 to the first cutting edge 5, wherein the distance is measured along a line parallel to the axis of rotation A1. Figures 24-26In the first direction 17, the clamping device 60 is away from the clamping device, and in the second direction 18, the clamping device is towards the clamping device. Alternatively (not shown), the first direction 17 is towards the clamping device 60, while the second direction 18 is away from the clamping device. The first direction 17 and the second direction 18 are therefore opposite directions along the axis of rotation A1. Thus, opposite directions can be understood as towards or away from the clamping device, or towards or away from a longitudinal end of the metal workpiece. Therefore, the first direction and the second direction are not necessarily linear and parallel to the axis of rotation.
[0144] Figure 27 This is a cross-sectional schematic diagram showing a first cutting element 7 in the form of a first turning insert 7, a second cutting element 8 in the form of a second turning insert 8, and a rotating metal workpiece. The first turning insert 7 and the second turning insert 8 are arranged according to a first, second, third, or fourth turning tool embodiment. The first turning insert 7 includes a first top surface 20 and a first bottom surface 22, both of which are horizontal or substantially horizontal. The second turning insert 8 includes a second top surface 21 and a second bottom surface 23, both of which are horizontal or substantially horizontal. A first intermediate plane P1 is located at the midpoint or substantially midpoint between the first top surface 20 and the first bottom surface 22. The first intermediate plane P1 is parallel or substantially parallel to the first bottom surface 22. A second intermediate plane P2 is arranged in a corresponding manner. The first intermediate plane P1 and the second intermediate plane P2 are arranged in parallel planes. The metal workpiece 2 rotates about its axis of rotation A1 in one direction 50. The first turning insert 7 and the second turning insert 8 are located on opposite sides of the axis of rotation A1. The first top surface 20 faces upward in the figure, and the second top surface 21 faces downward in the figure. When the first cutting insert 7 is in the cutting state, the second cutting insert 8 separates from the metal workpiece 2.
[0145] Figure 25 and Figure 26 The diagram illustrates how the second direction 18 is directed away from the corner of the metal workpiece 2. In other words, the second direction 18 is directed away from a surface that lies in a plane perpendicular to the axis of rotation A1. The corner or shoulder is the intersection between a surface concentric with the axis of rotation and a second surface perpendicular to the axis of rotation. The corner is a 90° angle. Preferably, the corner is entirely formed by the second cutting element, wherein the turning tool moves toward the axis of rotation A1 immediately before moving in the second direction 18.
[0146] The first turning insert 7 and the second turning insert 8 described in the above embodiments are preferably made of a wear-resistant material, preferably cemented carbide. The first top surface 20 and the second top surface 21 preferably include a chip forming device or a chip breaking device (not shown). Preferably, the distance from at least a portion of the chip forming device or chip breaking device to the mid-plane of the respective turning insert is greater than the distance from the cutting edge that borders the top surface to the mid-plane. In other words, the top surface 20 of the first turning insert and the top surface 21 of the second turning insert include at least one protrusion that is higher than or above the cutting edge in a side view. This makes the turning inserts more suitable for turning.
[0147] The first turning insert 7 and the second turning insert 8 described in the above embodiments are preferably designed such that the first forward cutting edge 12 is inclined downward at a gradually increasing distance from the first cutting edge 5, i.e., inclined towards the first bottom surface 22. The second forward cutting edge 13 is preferably arranged in a corresponding manner. In this way, chip control is further improved.
[0148] The forward and backward cutting edges move forward and backward in their respective feed directions, not necessarily relative to the forward or backward direction of the turning tool itself.
Claims
1. A turning method for a CNC lathe, comprising the following steps: Provide metal workpieces (2). Provide turning tools (1). The turning tool (1) includes a connecting part (3). The connecting portion (3) extends along the connecting central axis (A2). The turning tool (1) includes a first cutting element (7) and a second cutting element (8). The first cutting element (7) includes a first cutting edge (5); The second cutting element (8) includes a second cutting edge (6), which separates the second forward cutting edge (13) and the second backward cutting edge (15) and connects the second forward cutting edge (13) and the second backward cutting edge (15). The metal workpiece (2) is rotated about its axis of rotation (A1) in one direction (50); The turning tool (1) is moved in the first direction (17) so that the first cutting edge (5) is in a cutting state. The turning tool (1) is moved in one direction (19) such that the first cutting edge (5) moves away from the metal workpiece (2) and the second cutting edge (6) moves towards the metal workpiece (2). The turning tool (1) is moved in the second direction (18) such that the second forward cutting edge (13) is in a cutting state with a second approach angle (β) of 5–45°. The second direction (18) is the opposite direction of the first direction (17), or the substantially opposite direction of the first direction (17).
2. The turning method according to claim 1, in, The first cutting element (7) includes a first forward cutting edge (12) and a first backward cutting edge (14); Wherein, the first cutting edge (5) is the first cutting edge tip (5); The first cutting edge (5) separates the first forward cutting edge (12) and the first backward cutting edge (14) and connects the first forward cutting edge (12) and the first backward cutting edge (14). When the turning tool (1) is moved in the first direction (17), the first forward cutting edge (12) forms a first entry angle (α) of 5-45°.
3. The turning method according to claim 1 or 2, in, When the turning tool (1) is moved in the second direction (18), the second backward cutting edge (15) forms an obtuse back clearance angle (δ).
4. The turning method according to claim 2, in, When the turning tool (1) is moved in the first direction (17), the first backward cutting edge (14) forms an obtuse back clearance angle (γ).
5. The turning method according to any one of claims 1-2, in, When the turning tool (1) is moved in the second direction (18), the turning method includes turning at least a portion of the surface (25) being machined when the turning tool (1) is moved in the first direction (17).
6. The turning method according to any one of claims 1-2, in, The step of moving the turning tool (1) in one direction (19) such that the first cutting edge (5) moves away from the metal workpiece (2) and the second cutting edge (6) moves toward the metal workpiece (2) is performed without the turning tool (1) rotating about the connecting center axis (A2).
7. The turning method according to any one of claims 1-2, in, The connecting center axis (A2) is parallel to or perpendicular to the rotation axis (A1).
8. The turning method according to any one of claims 1-2, in, The metal workpiece (2) is clamped by the clamping device (60). The distance from the clamping device to the second cutting edge (6) is shorter than the distance from the clamping device (60) to the first cutting edge (5).
9. The turning method according to any one of claims 1-2, in, When the turning tool (1) is moved in the first direction (17), the second cutting edge (6) is located in front of the first cutting edge (5) in the first direction (17). When the turning tool (1) is moved in the second direction (18), the first cutting edge (5) is located in front of the second cutting edge (6) in the second direction (18).
10. The turning method according to any one of claims 1-2, in, The second direction (18) is in the direction away from the corner of the metal workpiece (2).
11. The turning method according to any one of claims 1-2, This includes another step: turning in the third direction, such that the second forward cutting edge (13) is in an active state with an obtuse third entry angle. in, The third direction is oriented toward the axis of rotation (A1).
12. The turning method according to any one of claims 1-2, in, The first cutting element (7) is the first turning insert (7). The second cutting element (8) is the second turning insert (8). The first turning insert (7) includes a first top surface (20) and a first bottom surface (22). The first top surface (20) and the first bottom surface (22) are connected by a first side surface. The second turning insert (8) includes a second top surface (21) and a second bottom surface (23). The second top surface (21) and the second bottom surface (23) are connected by the second side surface. The first top surface (20) and the second top surface (21) include chip breaking devices.
13. The turning method according to any one of claims 1-2, in, The cross-section of the connecting part (3) is square or rectangular, or the connecting part (3) includes a conical or basically conical part.
14. The turning method according to any one of claims 1-2, in, The method further includes another step: arranging the turning tool (1) such that the metal workpiece (2) is located between the first cutting edge (5) and the second cutting edge (6).
15. A computer-readable medium having instructions that, when executed by a CNC lathe, cause the CNC lathe to perform the steps according to any one of claims 1-14.