Turning tool for metal cutting
By designing the turning tool so that the top surfaces of the first and second cutting elements are aligned, and by utilizing the Y-axis movement of the CNC lathe to achieve rapid indexing, the problem of long indexing time in the machining of complex shapes by existing turning tools is solved, thereby improving machining efficiency and applicability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SANDVIK COROMANT
- Filing Date
- 2021-11-03
- Publication Date
- 2026-05-29
AI Technical Summary
Existing turning tools require frequent indexing when machining complex shapes, leading to increased downtime and making them difficult to use efficiently on a wide range of CNC lathes.
Design a turning tool in which the top surfaces of the first and second cutting elements face the same or substantially the same direction, and achieve rapid indexing by moving along the Y-axis of a CNC lathe, thereby reducing indexing time.
By optimizing the tool design, indexing time was reduced, improving efficiency and applicability in machining complex shapes, and reducing downtime.
Smart Images
Figure CN116583371B_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 tool according to the present invention. In other words, the present invention relates to a turning tool including a connecting portion, wherein the connecting portion extends along a connecting axis, wherein the connecting axis extends along the longitudinal axis of the turning tool, wherein the turning tool includes a first cutting element and a second cutting element, wherein the first cutting element includes a first cutting edge, wherein 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, wherein the first cutting element includes a first top surface, and wherein the second cutting element includes a second top surface.
[0003] In another aspect, the present invention relates to a machining method for a CNC lathe.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] The inventors have discovered a need for further improvements to turning tools. Summary of the Invention
[0008] One object of the present invention is to provide a turning tool suitable for machining objects with complex shapes. A further object is to provide a turning tool that can be used on a wide range of CNC lathes. A further object is to provide a turning tool that can be used during long machining times. Yet another object is to provide a turning tool that helps reduce downtime.
[0009] At least one of the objectives is achieved by a turning tool that is initially defined, wherein the first top surface and the second top surface face the same or substantially the same direction.
[0010] With such a turning tool, the change or indexing from the first cutting element to the second cutting element can be quickly achieved by moving the turning tool along the Y-axis of the CNC lathe to which the turning tool can be connected.
[0011] This turning tool is used on a CNC lathe, i.e., a computerized or computerized CNC lathe, that is, any CNC machine tool suitable for turning, such as a turning lathe, a multi-tasking machine tool, a milling machine, or a sliding head machine tool. The turning tool is used to machine metal workpieces, for example, metal workpieces including an outer surface, which is a radially outer surface, wherein the radially outer surface faces away from the axis of rotation about which the metal workpiece can rotate. The turning tool is used to turn said radially outer surface, i.e., external turning.
[0012] Turning tools consist of a front end and an opposite rear end in the form of a connecting portion. The connecting portion can be detachably connected to a CNC lathe, and more specifically, to the machine tool interface of the CNC lathe, such as the machine spindle or tool turret or tool post.
[0013] The cross-section of the connecting part can be square or rectangular. The connecting part can be tapered or substantially tapered, preferably in the shape according to ISO standard 26623-1.
[0014] The connecting portion extends along the connecting axis or central axis, which defines the longitudinal axis of the turning tool.
[0015] The turning tool (1) includes a first cutting element (7) and a second cutting element (8). The first and second cutting elements are spaced apart. 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 rake surface.
[0016] The first cutting element includes a first cutting edge. The first cutting edge includes at least a convex portion in a top view. A tool tip cutting edge or a portion of the tool tip cutting edge creates a machined surface. The first cutting element may be in the form of a rounded cutting insert, i.e., an insert that is circular or substantially circular in a top view. The radius of the circle is preferably 5-30 mm. Alternatively, the first cutting edge may be in the form of a first tool tip cutting edge, which is convex in a top view, preferably in the form of an arc, having a radius of curvature of 0.2-1.6 mm, and is arranged between a first forward cutting edge (i.e., a primary cutting edge or main cutting edge or front cutting edge) and a first backward cutting edge (i.e., an auxiliary cutting edge or tail cutting edge), i.e., connecting the first forward cutting edge and the first backward cutting edge.
[0017] The first top surface can be rhomboid, triangular, square, circular, or polygonal in a top view.
[0018] Both the first and second top surfaces can be flat. Alternatively, one or both of the surfaces can be uneven or non-planar. Preferably, the surfaces can 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 an intermediate plane 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 may be defined as a plane that intersects with all cutting edges of the tool tip that are adjacent to or border the first top surface.
[0022] The corresponding reasoning applies to the second top surface and the second cutting element.
[0023] 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.
[0024] The first cutting element is preferably in the form of a first cutting insert, comprising a first top surface and an opposite first bottom surface, wherein the first top surface includes a first rake face. Preferably, the second cutting element is in the form of a second cutting insert, comprising a second top surface and an opposite second bottom surface, wherein the second top surface includes a second rake face. The first bottom surface faces the second top surface.
[0025] The first rake face is associated with the first cutting edge at the tool tip, and the second rake face is associated with the second cutting edge. The first bottom surface and the second bottom surface are parallel planes or substantially parallel planes.
[0026] The first top surface and the second top surface face the same or substantially the same direction, preferably in a direction perpendicular or substantially perpendicular to the connecting axis, or in a direction perpendicular or substantially perpendicular to a line parallel to the connecting axis.
[0027] Preferably, in a top view, with the first and second front cutters facing the observer, the distance from the connecting axis to the first cutting edge is shorter than the distance from the connecting axis to the second cutting edge.
[0028] This turning tool is suitable for external turning of cylindrical metal workpieces, preferably longitudinal turning. The first and second cutting elements can be used alternately for longitudinal turning of the metal workpiece, which rotates in one direction about its axis of rotation.
[0029] 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 in the form of a first tip cutting edge, wherein the first tip cutting edge separates the first forward cutting edge and the first backward cutting edge and connects the first forward cutting edge and the first backward cutting edge.
[0030] With such a turning tool, more complex shapes can be machined. For example, grooves can be machined. Preferably, in a top view, the first and second forward cutting edges form an angle of 90-174° relative to each other. Even more preferably, the angle is 95-140°.
[0031] Preferably, in the top view, the first and second forward cutting edges are angled or inclined in opposite directions relative to the connecting axis. Alternatively, in the top view, one of the first and second forward cutting edges forms a positive angle relative to a line parallel to the connecting axis, while the other forms a negative angle, the connecting axis extending intermediately between the first and second cutting edges. More specifically, in the top view and relative to a line parallel to the connecting axis extending intermediately between the first and second cutting edges, the first forward cutting edge forms a first rake angle preferably 3-45°, and the second forward cutting edge forms a second rake angle preferably -3-45°. The first and second cutting elements are oriented such that, in the top view, i.e., with the first and second rake faces facing the observer, the first and second forward cutting edges diverge in the forward direction and converge in the rearward direction, wherein the forward and rearward directions are defined by the connecting axis, with the connecting portion defining the rearward direction.
[0032] In the top view, the line coinciding with the first forward cutting edge intersects at the intersection or vertex with the line coinciding with the second forward cutting edge, wherein, measured along the connecting axis and along a line parallel to the connecting axis, the distance from the connecting portion to the first cutting edge is greater than the distance from the connecting portion to the intersection or vertex. In other words, the intersection or vertex is located behind the first cutting edge.
[0033] Preferably, the first cutting element is arranged such that when turning in a first direction perpendicular to the connecting axis, the first forward cutting edge forms a first entry angle of 3-45°, wherein the second cutting element is arranged such that when turning in a second direction opposite to the first direction (and preferably perpendicular to the connecting axis), the second forward cutting edge forms a second entry angle of 3-45°.
[0034] Therefore, when turning in a first direction perpendicular to the connecting axis, the first forward cutting edge is arranged or adapted to operate with an acute angle of entry, wherein when turning in a second direction, the second forward cutting edge is arranged to operate with an acute angle of entry, wherein the second direction is the opposite direction to the first direction.
[0035] According to one embodiment, in a top view, the first bisector between the first forward cutting edge and the first backward cutting edge forms an angle of 45-90° with respect to the second bisector between the second forward cutting edge and the second backward cutting edge.
[0036] With such a turning tool, more complex shapes can be machined.
[0037] A top view is the view where the first top surface faces the observer.
[0038] According to one embodiment, in a top view, the first and second backward cutting edges form an angle of 6-20° relative to each other.
[0039] Such turning tools allow for the machining of more complex shapes. They also enable a wider range of feed directions.
[0040] More precisely, in the top view, the line coinciding with the first backward cutting edge forms an angle of 6-20° relative to the line coinciding with the second backward cutting edge in the top view.
[0041] According to one embodiment, the distance from the first forward cutting edge to the second forward cutting edge is shorter than the distance from the first forward cutting edge to the second backward cutting edge.
[0042] With such a turning tool, more complex shapes can be machined. With such a turning tool, the first cutting element can be used in one feed direction, and the second cutting element can be used in the opposite feed direction.
[0043] The distance was measured along a line perpendicular to the connection axis in a top view.
[0044] According to one embodiment, the first tool tip angle, defined as the angle between the first forward cutting edge and the first backward cutting edge, is an acute angle.
[0045] Such turning tools can be used to machine more complex shapes. Preferably, the tool tip angle is 25-80°, more preferably 30-60°. The first tool tip angle is visible in the top surface.
[0046] According to one embodiment, the second tool tip angle, defined as the angle between the second forward cutting edge and the second backward cutting edge, is an acute angle.
[0047] Such turning tools can be used to machine more complex shapes. Preferably, the second tool tip angle is 25-80°, more preferably 30-60°. The second tool tip angle is shown in the top view.
[0048] According to one embodiment, the first cutting edge and the second cutting edge are at equal or substantially equal distances in the longitudinal direction.
[0049] With this type of turning tool, less movement is required when indexing from the first cutting element to the second cutting element. Measurements are taken longitudinally from the connecting portion along a line parallel to the connecting axis. Substantially equal distances mean within 5 mm, preferably within 2 mm. In the case where the distances are not unequal but substantially equal, i.e. within 5 mm, it is preferable that the distance from the first cutting edge to the connecting portion is greater.
[0050] According to one embodiment, the first cutting edge and / or the second cutting edge are the furthest longitudinal portion of the turning tool.
[0051] In other words, the first and / or second cutting edges are the longitudinal foremost part of the turning tool, where the connecting axis is the longitudinal axis and the connecting part defines the rearward direction or rearward end.
[0052] According to one embodiment, the first cutting element is in the form of a first turning insert, and the second cutting element is in the form of a second turning insert, wherein the first turning insert includes a first cutting edge at the tip, and the second turning insert includes a second cutting edge at the tip, a second forward cutting edge, and a second backward cutting edge.
[0053] Preferably, the first turning insert includes a first forward cutting edge and a first backward cutting edge.
[0054] According to one embodiment, a first turning insert includes a first top surface and an opposite first bottom surface, wherein a first middle plane extends substantially intermediately between the first top surface and the first bottom surface, and a second turning insert includes a second top surface and an opposite second bottom surface, wherein a second middle plane extends substantially intermediately between the second top surface and the second bottom surface, wherein the first middle plane and the second middle plane extend in parallel or substantially parallel planes.
[0055] According to one embodiment, in a top view, the first turning insert and the second turning insert partially overlap.
[0056] The first and second turning inserts partially overlap but not completely.
[0057] According to one embodiment, the turning tool includes a third cutting element.
[0058] The third cutting element is preferably in the form of a third cutting insert. Preferably, the shape of the third cutting insert in the top view is different from that of the first and second cutting inserts.
[0059] Preferably, in the top view, the first, second, and third cutting elements partially overlap.
[0060] Preferably, the turning tool includes a third protrusion, wherein the third protrusion includes a third cutting element.
[0061] According to one embodiment, the cross-section of the connecting portion is square or rectangular, or includes a tapered or substantially tapered portion.
[0062] 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 (e.g., according to ISO 26623-1:2014), or in the form of a hollow tapered portion with a flanged contact surface (e.g., according to DIN 69893, ISO 12164-1, or ISO 12164-1F).
[0063] According to one embodiment, a turning method for a data lathe includes the following steps: providing a metal workpiece, providing a turning tool according to any of the above embodiments, rotating the metal workpiece about its axis of rotation in one direction; turning in the first direction such that a 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 a second cutting edge moves toward the metal workpiece; moving the turning tool in a second direction such that a second forward cutting edge operates at a second entry angle of 5-45°, wherein the second direction is the opposite or substantially opposite direction to the first direction.
[0064] The turning method is suitable for CNC lathes, i.e., computerized or computerized CNC 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. The radial outer surface faces away from the axis of rotation. The turning method involves turning the radial outer surface, i.e., 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.
[0065] 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 spindle head of the machine tool is preferably located at the first end of the metal workpiece. The second end of the metal workpiece, opposite the first end, can be a free end. Alternatively, the second end may contact the tailstock.
[0066] 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.
[0067] The method preferably includes the step of setting the connecting axis to be perpendicular to the rotation axis.
[0068] The method includes a turning step in a first direction. The first direction may preferably be parallel to the axis of rotation, also referred to as longitudinal turning. The step is included in a first feed, defined as the movement of the first cutting element along a straight line between entry and exit from the cutting direction. The first feed is not necessarily the movement of the first cutting element along a straight line. During turning in the first direction, a first cutting edge at the tool tip is activated. The machined surface is formed by the first cutting edge at the tool tip.
[0069] Preferably, the first cutting element includes a first forward cutting edge and a first backward cutting edge, wherein a first cutting tip edge separates the first forward cutting edge and the first backward cutting edge and connects the first forward cutting edge and the first backward cutting edge, wherein when turning in a first direction, the first forward cutting edge forms a first entry angle with an acute angle.
[0070] After or during cutting, the turning tool is moved such that the first cutting edge moves away from the workpiece and the second cutting edge moves towards the 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.
[0071] The movement of the turning tool can preferably be linear, that is, the turning tool moves linearly.
[0072] The movement of the turning tool is preferably in a direction perpendicular to both the connecting axis and the rotation axis. The movement is preferably performed in a direction perpendicular to or substantially perpendicular to the first top surface.
[0073] The method includes a turning step in a second direction, i.e., moving the turning tool in the second direction. The second direction is the opposite or substantially opposite direction to the first direction. For example, the first and second directions may be parallel to the axis of rotation but opposite in direction. The step is included in a second path, which is defined between entering and exiting the cutting process. The second path 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 a second entry angle of 5-45°, or even more preferably 5-30°.
[0074] When turning in the first direction, the second cutting element is inactive. When turning in the second direction, the first cutting element is inactive.
[0075] Preferably, the method includes an additional step of setting the second rearward cutting edge to form an obtuse clearance angle when turning in the second direction. Preferably, the clearance angle is 91°-135°, more preferably 93°-120°.
[0076] Preferably, the method includes an additional step of setting the first backward cutting edge to form a back clearance angle of at least 91° when turning in the first direction.
[0077] Preferably, the method includes an additional step: turning at least a portion of the surface machined in the first pass while turning in the second direction.
[0078] Preferably, the step of moving the turning tool so that the first cutting edge moves away from the metal workpiece and the second cutting edge moves towards the metal workpiece is performed without rotation of the turning tool around the connecting center axis. This step is preferably a linear movement of the turning tool, and more preferably a linear movement along the Y-axis of the CNC lathe. Therefore, the indexing time can be shorter compared to rotary movement.
[0079] Preferably, the turning tool does not rotate about the connecting axis during the first pass, during the second pass, or between the first and second passes. Preferably, the turning tool does not rotate about any other axis, such as any axis parallel to the connecting axis, during the first and second passes, or between the first and second passes.
[0080] Preferably, the method includes the step of arranging the first and second tool tip cutting edges at a constant distance spaced along the axis of rotation when turning in the first and second directions. Preferably, this is also done during the step between the first and second passes.
[0081] Preferably, the method includes the step of setting the connecting axis to be perpendicular to the rotation axis.
[0082] Preferably, the method includes the step of: clamping a metal workpiece by a clamping device, wherein the clamping device includes a three-jaw chuck.
[0083] Preferably, 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.
[0084] Preferably, when turning in the first direction, the second cutting edge is in front of the first cutting edge.
[0085] Preferably, when turning in the second direction, the first cutting edge is in front of the second cutting edge. "In front" should be understood as in front of the cutting edge along the axis of rotation in the feed direction.
[0086] Preferably, the second feed is in a direction away from the corner. 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 external surface or an internal surface, i.e., a surface inside the hole. Preferably, the first surface is an external surface, i.e., a radially outer surface.
[0087] According to one aspect of the invention, a computer program having instructions that, when executed by a CNC lathe, cause the CNC lathe to perform the steps according to any of the methods described above.
[0088] 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
[0089] The invention will now be explained in more detail through a description of embodiments thereof and with reference to the accompanying drawings.
[0090] Figure 1 This is a perspective view of a turning tool according to one embodiment.
[0091] Figure 2 yes Figure 1 A side view of a turning tool.
[0092] Figure 3 yes Figure 1 Front view of the turning tool in the image.
[0093] Figure 4 yes Figure 1 A top view of a turning tool.
[0094] Figure 5 yes Figure 4 An enlarged view of part B in the image.
[0095] Figure 6 yes Figure 1 A top view of the turning tool and the metal workpiece.
[0096] Figure 7 yes Figure 1 A side view of the turning tool and the metal workpiece.
[0097] Figure 8 yes Figure 1 A top view of the turning tool and the metal workpiece.
[0098] Figure 9 This is a schematic diagram of the movement of a turning tool in the first direction.
[0099] Figure 10 This is a schematic diagram of the movement of a turning tool in the second direction.
[0100] Figure 11 This is a schematic diagram showing the first cutting element and the rotating metal workpiece in cross-section.
[0101] All turning tools in the diagram are drawn to scale. Detailed Implementation
[0102] refer to Figures 1-8 This illustration shows a turning tool 1 according to one 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 section. In this example, the substantially tapered section is, according to industry standards, Coromant Capto®. The connecting portion may have other shapes, such as a square or rectangular cross-section, wherein the cross-section is perpendicular to the connecting axis.
[0103] 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 tip cutting edge 5, a first forward cutting edge 12, and a first backward cutting edge 14. The first tip cutting edge 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 tip cutting edge 6, a second forward cutting edge 13, and a second backward cutting edge 15. The second tip cutting edge 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 tip cutting edge 6. The second cutting element 8 includes a second top surface 21 and an opposite second bottom surface.
[0104] 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 2 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 2 The middle represents upward movement.
[0105] As shown in Figure 3, the distance from the connecting axis A2 to the second cutting edge of the tool tip is greater than the distance from the connecting axis A2 to the first cutting edge of the tool tip 5. This distance is... Figure 3 The distance is measured horizontally. In other words, the distance is the distance to a first plane including the connecting axis, wherein the first plane is perpendicular to the first mid-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 4 and Figure 5 ( Figure 5 yes Figure 4 As shown in the enlarged view of part B in the figure, 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 4 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.
[0106] exist Figure 5 In the top view, the first turning insert 7 and the second turning insert 8 partially overlap.
[0107] Figure 6 An example of the first step of a turning method on 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, the connecting portion is connected to the machine tool 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.
[0108] After the first step, the turning tool 1 moves in direction 19, which is perpendicular to the connecting axis A2 and the rotation axis A1, as follows: Figure 7 As shown. The direction 19 is in the same or substantially the same direction as the direction in which the first top surface 20 faces. The direction 19 is along the Y-axis of the CNC lathe (not shown) to which the turning tool 1 is connected. The direction 19 is not radial relative to the axis of rotation 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 causes the second cutting edge 6 to move 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.
[0109] Figure 8 It shows in Figure 7 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 a second entry angle β of 5–45°. The machined surface is formed by the second tip cutting edge 6. The second direction 18 is in 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 8 In the steps shown, for the... Figure 6 At least a portion of the machined surface produced by the steps shown is machined.
[0110] The metal workpiece can have a shape different from those described above. The metal workpiece can be a bar, a hollow bar, or any other shape that is rotationally symmetric or substantially rotationally symmetric about its axis of rotation. The machinable shape can have a construction different from that described above. For example, the shape can have not only one sidewall, but two sidewalls, i.e., a surface in a plane perpendicular to the axis of rotation. In other words, turning tools can be used to machine external grooves.
[0111] Figure 9 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. The first forward cutting edge forms a first entry angle α of 5–45°, and the 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, the surface 25 is formed by the first cutting edge 5.
[0112] Figure 10This is a schematic diagram of the turning tool moving in the second direction 18, where the second cutting element 8 is in the 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. Figure 10 In the middle, when the turning tool 1 is moved in the first direction 17 (see...) Figure 9 At least a portion of the surface 25 being machined is machined by means of the second cutting element 8.
[0113] Figure 9 The first processing step is shown, followed by Figure 10 The steps are shown. In Figure 10 In the middle, the second cutting element 8 is located at the axis of rotation A1 and... Figure 9 The first cutting element 7 is on the same side, and the first top surface and the second top surface face the same direction.
[0114] exist Figure 9 and Figure 10 In this process, one end of the metal workpiece 2 is clamped 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. Figure 9 and Figure 10 In the first direction 17, the clamping device 60 is away from the clamping device, and the second direction 18 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 in 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 2. Therefore, the first direction 17 and the second direction 18 are not necessarily linear and parallel to the axis of rotation A1.
[0115] Figure 11This is a schematic cross-section showing a first cutting element 7 in the form of a first turning insert 7 and a rotating metal workpiece 2. 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. A first mid-plane P1 is located between or substantially between the first top surface 20 and the first bottom surface 22. The first mid-plane P1 is parallel or substantially parallel to the first bottom surface 22. The metal workpiece 2 rotates about its axis of rotation A1 in one direction 50. The first top surface 20 faces upward in the figure. When the first turning insert 7 is in the cutting state, a second turning insert (not shown) separates from the metal workpiece 2.
[0116] Figure 10 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.
[0117] 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 corresponding 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 insert more suitable for turning.
[0118] 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 tip 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.
[0119] The forward and backward cutting edges are forward and backward in the corresponding feed direction, not necessarily in the forward or backward direction relative to the turning tool itself.
Claims
1. A turning tool (1), the turning tool including a connecting portion (3). in, The connecting portion (3) extends along the connecting axis (A2), The connecting axis (A2) defines the longitudinal axis of the turning tool (1). 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 first cutting element (7) includes a first top surface (20). The second cutting element (8) includes a second top surface (21). Its features are, The first top surface (20) and the second top surface (21) face the same or substantially the same direction. The first cutting element (7) includes a first forward cutting edge (12) and a first backward cutting edge (14). The first cutting edge (5) is in the form of a 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). In the top view, 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). The first cutting element is arranged such that when turning in a first direction perpendicular to the connecting axis, the first forward cutting edge forms a first approach angle of 3-45°, and The second cutting element is arranged such that when turning in a second direction opposite to the first direction, the second forward cutting edge forms a second approach angle of 3-45°.
2. The turning tool (1) according to claim 1. in, In the top view, the first backward cutting edge (14) and the second backward cutting edge (15) form an angle of 6-20° relative to each other.
3. The turning tool (1) according to any one of claims 1-2. in, The distance from the first forward cutting edge (12) to the second forward cutting edge (13) is less than the distance from the first forward cutting edge (12) to the second backward cutting edge (15).
4. The turning tool (1) according to any one of claims 1-2. in, 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.
5. The turning tool (1) according to any one of claims 1-2 in, 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.
6. The turning tool (1) according to any one of claims 1-2 in, The first cutting edge (5) and the second cutting edge (6) are equidistant or substantially equidistant in the longitudinal direction.
7. The turning tool (1) according to any one of claims 1-2 in, The first cutting edge (5) and / or the second cutting edge (6) are the furthest longitudinal portion of the turning tool (1).
8. The turning tool (1) according to any one of claims 1-2 in, The first cutting element (7) is in the form of a first turning insert (7). The second cutting element (8) is in the form of a second turning insert (8). The first turning insert includes the first cutting edge (5) at the tip. The second turning insert (8) includes the second cutting edge (6), the second forward cutting edge (13), and the second backward cutting edge (15).
9. The turning tool (1) according to claim 8. in, The first turning insert (7) includes a first top surface (20) and an opposite first bottom surface (22). The first mid-plane (P1) extends substantially between the first top surface (20) and the first bottom surface (22). The second turning insert (8) includes a second top surface (21) and an opposite second bottom surface (23). The second mid-plane (P2) extends substantially between the second top surface (21) and the second bottom surface (23). The first midplane (P1) and the second midplane (P2) extend in parallel or substantially parallel planes.
10. The turning tool (1) according to claim 8. in, In the top view, the first turning insert (7) and the second turning insert (8) partially overlap.
11. The turning tool (1) according to any one of claims 1-2. in, The turning tool (1) includes a third cutting element (9).
12. The turning tool (1) 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.
13. The turning tool (1) according to any one of claims 1-2 in, The second direction is perpendicular to the connecting axis.
14. A turning method for a CNC lathe, comprising the following steps: Provide metal workpieces (2). Provide a turning tool (1) according to any one of the preceding claims. The metal workpiece (2) is rotated about its axis of rotation (A1) in one direction (50); Turning is performed in the first direction (17), so that the first cutting edge (5) of the tool tip 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) operates at a second approach angle (β) of 5–45°. Wherein, the second direction (18) is the opposite or substantially opposite direction to the first direction (17), and The turning tool is moved in the first direction such that the first forward cutting edge cuts at a first entry angle (α) of 3-45°.
15. A computer-readable medium having instructions that, when executed by a CNC lathe, cause the CNC lathe to perform the steps of the turning method for a CNC lathe according to claim 14.