Turning drill bit for end face grooving and cutting
By designing a turning drill with mirror symmetrical geometry, the problem of existing turning drills leaving burrs and central stumps during the cutting process is solved, achieving high tool life and high quality cutting surfaces.
Patent Information
- Application Number
- CN202411400668.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-10-12
- Filing Date
- 2024-10-09
- Publication Date
- 2025-04-15
AI Technical Summary
Existing turning drills are prone to leave burrs and central stumps during the cutting process, and the tool life and productivity of manual turning drills are low, and the cutting surface flatness is also poor.
A turning drill bit is designed, with the body extending along a longitudinal axis, including a retaining portion and at least one cutting portion. The geometry of the cutting portion has mirror symmetry, the cutting edge is arranged at a center point on the vertical plane, and the first cutting corner portion and the second cutting corner portion are arranged mirror symmetrically with respect to the longitudinal axis.
The turning drill bit generates a symmetric cutting force during the cutting process, keeping the tool stable, improving tool life and flatness of the cutting surface, and reducing the formation of burrs and central stumps.
Smart Images
Figure CN119819973A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a turning drill bit for end face grooving or cutting off. Background Art
[0002] Such turning drill bits are known.
[0003] These turning drills are particularly designed for the so-called cut-off process. In this process, while a metal workpiece (usually in the form of a rod) is rotating, an axial portion of the workpiece is cut off by means of the turning drill.
[0004] Straight turning drills usually have two cutting corners joined together by a straight cutting edge. The cutting edge extends perpendicularly to the longitudinal axis of the turning drill, so that the two cutting corners are arranged at the same height and therefore penetrate the workpiece simultaneously during cut-off.
[0005] The disadvantage of straight turning drills is that they leave burrs and center stumps on the workpiece and on the cut-off portion.
[0006] In order to cut off parts without burrs and without center stumps, so-called manual (ie left or right) turning drills are used, wherein the left or right cutting corner respectively protrudes relative to the other cutting corner and thus penetrates into the workpiece first.
[0007] The disadvantage of manual turning drills is that their tool life and productivity are reduced due to the higher stress placed on the protruding corners. In addition, this cutting edge geometry produces asymmetric cutting forces, which lead to warping of the turning drill and thus reduce the flatness of the cut-off surface. Summary of the invention
[0008] The problem addressed by the present invention is to provide a turning drill for face grooving or parting off which has a high tool life and has a high part quality.
[0009] This problem is solved by a turning drill for face grooving and cutting, which has a body extending along a longitudinal axis and comprising a holding portion and at least one cutting portion. The holding portion has a maximum width smaller than the maximum width of the at least one cutting portion. In addition, the at least one cutting portion comprises an upper surface, a lower surface arranged opposite to the upper surface, a first lateral surface, a second lateral surface arranged opposite to the first lateral surface, and an end surface. The first lateral surface and the second lateral surface each extend from the lower surface to the upper surface, while the first lateral surface abuts the upper surface via a first lateral edge, and the second lateral surface abuts the upper surface via a second lateral edge. The end surface extends from the lower surface to the upper surface and from the first lateral surface to the second lateral surface, and further abuts the upper surface via a cutting edge. The cutting edge abuts the first lateral edge via a first cutting corner, and abuts the second lateral edge via a second cutting corner. The first cutting corner and the second cutting corner are arranged mirror-symmetrically with respect to a vertical plane extending along the longitudinal axis. In addition, the cutting edge has a center point arranged on the vertical plane. The center point is spaced apart from the axial plane toward the holding portion. Furthermore, the first cutting corner and the second cutting corner are arranged in an axial plane, while the axial plane extends orthogonally to the longitudinal axis. Thus, the cutting edge comprises a first cutting edge portion and a second cutting edge portion, the first cutting edge portion and the second cutting edge portion extending from the center point to the first cutting corner and the second cutting corner, respectively, and extending at an angle greater than zero to each other.
[0010] It has been found that, due to this geometry, the turning drill has particularly advantageous cutting properties and a high tool life. Due to the fact that the two cutting edges are arranged over the same axial length and therefore penetrate the workpiece simultaneously during the cut-off, symmetrical cutting forces are generated, so that the turning drill remains dimensionally stable during the cut-off and thus results in a high flatness of the cut-off surface. The cutting edge portions of the cutting edges aligned with one another enable the portion to be cut off without burrs or with reduced burrs or without a center stump or with a reduced center stump.
[0011] In one embodiment, at least one cutting portion is designed so as to be mirror-symmetrical with respect to a vertical plane. This offers the advantage that the load during cut-off is particularly evenly distributed, whereby the turning drill has a particularly long tool life.
[0012] Additionally or alternatively, the end face may form a tool flank for the cutting edge, wherein the tool flank has a clearance angle in the range of 5° to 12°. As a result, the friction between the turning drill and the workpiece is low.
[0013] In another embodiment, the end face comprises a first end face portion and a second end face portion, each of which adjoins the cutting edge and each extends at a setting angle in the range of 6° to 20° relative to the axial plane. Due to this geometry, the cutting edge has particularly advantageous cutting characteristics, which in particular leads to reduced burr formation.
[0014] The first end face portion may adjoin the first lateral face via the first end edge, and the second end face portion may adjoin the second lateral face via the second end edge. In particular, the first end edge may adjoin the first cutting corner, and the second end edge may adjoin the second cutting corner. In this way, the cutting portion is particularly robustly designed.
[0015] Furthermore, it can be provided that the cutting edge, the first side edge and the second side edge extend in a common plane, whereby the load during cut-off is distributed particularly evenly over the cutting part.
[0016] In an alternative embodiment, the center point is spaced apart from the horizontal plane toward the bottom. The first cutting corner and the second cutting corner are arranged in a horizontal plane extending parallel to the longitudinal axis. This geometry facilitates an advantageous chip formation.
[0017] The cutting edge can have a concave shape which, during turning, results in the formation of chips having a particularly small chip curvature radius.
[0018] According to one embodiment, a concave chip groove is formed thereon, as a result of which the chips are removed particularly quickly and almost frictionlessly during the cutting process.
[0019] According to another embodiment, the chip flute extends all the way to the cutting edge.In this way, chip formation and chip removal are particularly advantageous. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Other advantages and features will emerge from the following description and the accompanying drawings. The accompanying drawings show:
[0021] Figure 1 A turning drill according to the invention according to a first embodiment in a perspective view,
[0022] Figure 2 From the side view Figure 1 Turning drill bit,
[0023] Figure 3 In front view from Figure 1 Turning drill bit,
[0024] Figure 4 From the top view Figure 1 Turning drill bit,
[0025] Figure 5 Along the Figure 4 The cutting part of the turning drill bit in the cross-sectional view of plane EE,
[0026] Figure 6 A turning drill according to the invention according to another embodiment in a perspective view,
[0027] Figure 7 From the side view Figure 6 Turning drill bit,
[0028] Figure 8 In front view from Figure 6 Turning drill bit,
[0029] Fig. 9 From the top view Figure 6 Turning drill bit,
[0030] Fig.10 Along the Fig. 9 The cutting part of the turning drill bit in the cross-sectional view of plane EE,
[0031] Fig.11 A turning drill according to the invention according to another embodiment in a perspective view,
[0032] Fig.12 From the side view Fig.11 Turning drill bit,
[0033] Fig.13 In front view from Fig.11 Turning drill bit,
[0034] Fig.14 From the top view Fig.11 Turning drill bits, and
[0035] Fig.15 Along the Fig.14 The cutting part of the turning drill in the cross-sectional view of the plane EE, DETAILED DESCRIPTION
[0036] The following detailed description in conjunction with the accompanying drawings is intended as a description of various embodiments of the disclosed subject matter and is not intended to illustrate a single embodiment, wherein like numbers refer to like elements. Any embodiment described in the present disclosure is used only as an example or for illustrative purposes and should not be interpreted as preferred or advantageous over other embodiments.
[0037] All features disclosed below in connection with the exemplary embodiments and / or drawings may be combined with features of various aspects of the present disclosure (including features of the preferred embodiments) individually or in any sub-combination, as long as the resulting feature combination is reasonable for a person skilled in the art.
[0038] exist Figure 1 In FIG. 1 , a turning drill bit 10 is shown having a body 12 including a retaining portion 14 and a cutting portion 16 .
[0039] The holding portion 14 and the cutting portion 16 are each in the form of a cuboid and extend along a common longitudinal axis L which, in the exemplary embodiment shown, extends in the X direction.
[0040] In an alternative embodiment, the body 12 may include a plurality of cutting portions 16 .
[0041] For example, in one embodiment, the body 12 includes two cutting portions 16 disposed at opposite axial ends of the body 12 and connected to each other via the retaining portion 14 .
[0042] In particular, in an embodiment having multiple cutting portions 16, the cutting portions may be identical to one another.
[0043] Additionally or alternatively, in embodiments having multiple cutting portions 16 , the turning drill 10 may be designed as an indexable insert 10 such that only a portion of the cutting portions 16 , in particular only a single cutting portion 16 , is provided for simultaneous machining of a workpiece.
[0044] The turning drill bit 10 is designed for parting off, in particular, metal parts.
[0045] In principle, a turning drill 10 designed for parting off is also designed for face grooving.
[0046] In an alternative embodiment, the turning drill bit 10 may be configured for face grooving.
[0047] For face grooving or parting off, the turning drill 10 is clamped or otherwise secured in a tool holder (not shown) by means of the retaining portion 14 .
[0048] Furthermore, the holding portion 14 has a maximum width b which is smaller than a maximum width B of the cutting portion 16 in order to avoid contact of the holding portion 14 with the workpiece when the turning drill 10 cuts through the workpiece by means of the cutting portion 16 during cut-off.
[0049] At least one cutting portion 16 includes an upper surface 18, a lower surface 20 disposed opposite to the upper surface 18, a first lateral surface 22, and a second lateral surface 24 disposed opposite to the first lateral surface 22 (see Figure 2 ), and end face 26.
[0050] The first lateral surface 22 extends from the lower surface 20 to the upper surface 18. The intersection line where the first lateral surface 22 adjoins the upper surface 18 forms a first lateral edge 28.
[0051] The second lateral surface 24 extends from the lower surface 20 to the upper surface 18. The intersection line where the second lateral surface 24 adjoins the upper surface 18 forms a second lateral edge 30.
[0052] In the present embodiment, the first side edge 28 and the second side edge 30 form auxiliary cutting edges of the turning drill bit 10 .
[0053] The end face 26 extends from the lower face 20 to the upper face 18 and from the first lateral face 22 to the second lateral face 24. The intersection line where the end face 26 adjoins the upper face 18 forms a cutting edge 32 which is the main cutting edge of the turning drill 10.
[0054] The cutting edge 32 has a vertical plane VE arranged along the longitudinal axis L and extending in the Z direction (see Figure 3 ) is the center point P on .
[0055] The center point P divides the cutting edge 32 into a first cutting edge portion 34 and a second cutting edge portion 36 .
[0056] The first cutting edge portion 34 extends from the center point P to the first side edge 28 (see Figure 4 ), and is adjacent to the first side edge via a first cutting corner 38.
[0057] The second cutting edge portion 36 extends from the center point P to the second side edge 30 and adjoins the second side edge via a second cutting corner 40 .
[0058] In this context, the end face 26 has a first end face portion 42 (see Figure 1 ) and a second end surface portion 44.
[0059] Here, the first end face portion 42 adjoins the first cutting edge portion 34 and, via a first end edge 46 , the first lateral face 22 , while the second end face portion 44 adjoins the second cutting edge portion 36 and, via a second end edge 48 , the second lateral face 24 .
[0060] In the present embodiment, the first end edge 46 extends from the lower face 20 to the first cutting corner 38 , and the second end edge 48 extends from the lower face 20 to the second cutting corner 40 .
[0061] The end surface portions 42, 44 are planar and each is oriented at a clearance angle α of 7° relative to the axial plane AE when viewed in the XZ plane (see Figure 5 ) extends, the axial plane AE extends in the Y and Z directions, and the first cutting corner 38 and the second cutting corner 40 are arranged in the axial plane. In this way, the first end face portion 42 forms a tool side for the first cutting edge portion 34, and the second end face portion 44 forms a tool side for the second cutting edge portion 36.
[0062] In alternative embodiments, the clearance angle α may have a value in the range of 1° to 30°, in particular in the range of 5° to 12°.
[0063] Furthermore, when viewed in the XY plane, the end surface portions 42, 44 are each arranged at an angle β of 11° relative to the axial plane AE (see Figure 4 )extend.
[0064] In alternative embodiments, the setting angle β may have a value in the range of 1° to 60°, in particular in the range of 6° to 20°.
[0065] Therefore, the center point P is spaced apart from the axial plane AE by a distance A in the X direction toward the retaining portion 14 (see Figure 5 ). In other words, the center point P is offset rearwardly from the cutting corners 38, 40.
[0066] Furthermore, the center point P is spaced apart in the Z direction towards the lower side 20 by a distance V from a horizontal plane HE which extends parallel to the longitudinal axis L and in which the first cutting corner 38 and the second cutting corner 40 are arranged. This means that the center point P is offset downwardly from the cutting corners 38 , 40 .
[0067] In this context, the lateral edges 28, 30 extend in a horizontal plane HE (see Figure 2 ).
[0068] In the embodiment shown, the cutting edge 32 is concave when viewed in the X direction (see FIG. Figure 3 ).
[0069] The first cutting edge portion 34 and the second cutting edge portion 36 are each designed in a stepped or wavy manner.
[0070] In alternative embodiments, the first cutting edge portion 34 and the second cutting edge portion 36 may each have any shape.
[0071] The cutting portion 16 comprises a concave chip flute 50 and a chip guiding element 52 in the form of two extensions 54 formed by the upper face 18 .
[0072] The chip flute 50 extends in the X direction from the cutting edge 32 to the chip guide element 52 .
[0073] In the present embodiment, the turning drill bit 10 is designed so as to be mirror-symmetrical with respect to the vertical plane VE.
[0074] In alternative embodiments, the turning drill head 10 may be of any design as long as at least the first cutting corner 38 and the second cutting corner 40 are arranged mirror-symmetrically with respect to the vertical plane VE and are therefore at the same axial length.
[0075] Now it will be based on Figures 6 to 10 A turning drill head 10 according to a further embodiment is described. For the components known from the above embodiments, the same reference numerals are used and in this respect reference is made to the above explanations.
[0076] and Figures 1 to 5 Compared to the embodiment shown in Figures 6 to 10 In the turning drill head 10 shown in FIG. 1 , the center point P is arranged in the horizontal plane HE. That is, the distance V is zero.
[0077] Furthermore, the cutting edge portions 34, 36 each extend in a straight line from the center point P to a first cutting corner 38 and a second cutting corner 40, respectively.
[0078] Thus, the cutting edge portions 34, 36 and the side edges 28, 30 extend in a horizontal plane HE. Thus, the cutting corners 38, 40 and the center point P are also arranged in the horizontal plane HE.
[0079] Furthermore, in this embodiment, the end edges 46, 48 have rounded portions (see Figure 6 ).
[0080] Therefore, the cutting corners 38 , 40 are also rounded so that they can withstand the load longer.
[0081] Now it will be based on Figures 11 to 15 A turning drill head 10 according to a further embodiment is described. For the components known from the above embodiments, the same reference numerals are used and in this respect reference is made to the above explanations.
[0082] and Figures 1 to 5 Compared to the embodiment shown in Figures 11 to 15 In the turning drill 10 shown in FIG. 1 , the cutting edge portions 34 , 36 each extend in a straight line from a center point P to a first cutting corner 38 and a second cutting corner 40 , respectively.
[0083] Furthermore, the upper side 18 comprises a first upper portion 56 and a second upper portion 58 which extend from the cutting edge 32 towards the chip flute 50 , in particular in the X direction.
[0084] The first upper portion 56 adjoins the first end surface portion 42 via the first cutting edge portion 34 and adjoins the first lateral surface 22 via the first lateral edge 28 .
[0085] The second upper portion 58 adjoins the second end surface portion 44 via the second cutting edge portion 36 and adjoins the second lateral surface 24 via the second lateral edge 30 .
[0086] In this context, the upper portions 56 , 58 are each of planar form.
[0087] Due to the upper parts 56 , 58 , the cutting edge 32 is particularly robust, whereby the tool life of the turning drill 10 is particularly long.
[0088] In all embodiments, in this manner, a turning drill bit 10 is provided that provides improved cutting characteristics and reduced burr formation during face grooving or parting off.
[0089] Furthermore, the turning drill bit 10 has a high tool life.
[0090] In addition, the geometry of the turning drill 10 facilitates the formation of chips having a particularly small chip curvature radius, so that the chips are removed with little friction.
[0091] Reference numerals list
[0092] 10 Turning drill bit
[0093] 12 Main Body
[0094] 14 Keep part
[0095] 16 Cutting part
[0096] 18 above
[0097] 20 below
[0098] 22 First lateral surface
[0099] 24 Second lateral surface
[0100] 26 End face
[0101] 28 First side edge
[0102] 30 Second side edge
[0103] 32 cutting edges
[0104] 34 First cutting edge
[0105] 36 Second cutting edge
[0106] 38 First cutting corner
[0107] 40 Second cutting corner
[0108] 42 first end surface portion
[0109] 44 Second end surface portion
[0110] 46 First end edge
[0111] 48 Second end edge
[0112] 50 Chip groove
[0113] 52 Chip guide element
[0114] 54 Extension
[0115] 56, 58 upper part
Claims
1. A turning drill bit (10) for face grooving and parting, the turning drill bit having a body (12) extending along a longitudinal axis (L) and comprising a retaining portion (14) and at least one cutting portion (16), wherein the retaining portion (14) has a maximum width (b) that is smaller than a maximum width (B) of the at least one cutting portion (16), The at least one cutting portion (16) comprises an upper surface (18), a lower surface (20) arranged opposite to the upper surface (18), a first lateral surface (22), a second lateral surface (24) arranged opposite to the first lateral surface (22), and an end surface (26), wherein the first lateral surface (22) and the second lateral surface (24) each extend from the lower surface (20) to the upper surface (18), wherein the first lateral surface (22) adjoins the upper surface (18) via a first lateral edge (28), and the second lateral surface (24) adjoins the upper surface (18) via a second lateral edge (30), wherein the end surface (26) extends from the lower surface (20) to the upper surface (18) and from the first lateral surface (22) to the second lateral surface (24), wherein the end surface (26) adjoins the upper surface (18) via a cutting edge (32), wherein the cutting edge (32) adjoins the first side edge (28) via a first cutting corner (38) and adjoins the second side edge (30) via a second cutting corner (40), wherein the first cutting corner (38) and the second cutting corner (40) are arranged mirror-symmetrically with respect to a vertical plane (VE) extending along the longitudinal axis (L), It is characterized in that The cutting edge (32) has a center point (P) arranged on the vertical plane (VE), wherein the center point (P) is spaced apart from an axial plane (AE) toward the retaining portion (14), wherein the first cutting corner (38) and the second cutting corner (40) are arranged in the axial plane (AE), and the axial plane (AE) extends orthogonally to the longitudinal axis (L).
2. The turning drill bit (10) according to claim 1, characterized in that The at least one cutting portion (16) is designed so as to be mirror-symmetrical with respect to the vertical plane (VE).
3. The turning drill bit (10) according to claim 1 or 2, characterized in that: The end face (26) forms a tool flank for the cutting edge (32), wherein the tool flank has a clearance angle (α) in the range of 5° to 12°.
4. A turning drill bit (10) according to any one of the preceding claims, characterized in that The end face (26) comprises a first end face portion (42) and a second end face portion (44), the first end face portion and the second end face portion respectively adjoining the cutting edge (32) and each extending at a setting angle (β) in the range of 6° to 20° relative to the axial plane (AE).
5. The turning drill bit (10) according to claim 4, characterized in that The first end surface portion (42) adjoins the first end surface (22) via a first end edge (46), and the second end surface portion (44) adjoins the second end surface (24) via a second end edge (48), in particular wherein the first end edge (46) adjoins the first cutting corner (38) and the second end edge (48) adjoins the second cutting corner (40).
6. A turning drill bit (10) according to any one of the preceding claims, characterized in that The cutting edge (32), the first lateral edge (28) and the second lateral edge (30) extend in a common plane (HE).
7. The turning drill bit (10) according to any one of claims 1 to 5, characterized in that The center point (P) is spaced apart from a horizontal plane (HE) toward the lower face (20), wherein the first cutting corner (38) and the second cutting corner (40) are arranged in the horizontal plane (HE), and the horizontal plane (HE) extends parallel to the longitudinal axis (L).
8. The turning drill bit (10) according to claim 7, characterized in that The cutting edge (32) has a concave shape.
9. A turning drill bit (10) according to any one of the preceding claims, characterized in that The upper surface (18) forms a concave chip groove (50).
10. The turning drill bit (10) according to claim 9, characterized in that The chip flute (50) extends all the way to the cutting edge (32).