Rotary cutting tool with through coolant passage
By introducing a central coolant channel and a contoured radial coolant channel into the rotary cutting tool, the fatigue problem caused by the end milling cutter due to high temperature cutting is solved, and effective cooling of the cutting edge and tool life are achieved.
Patent Information
- Application Number
- CN202510083610.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-02-09
- Filing Date
- 2025-01-20
- Publication Date
- 2025-08-12
AI Technical Summary
Existing end milling cutters are fatigued due to high cutting temperature during cutting, which affects the tool life.
A rotary cutting tool is designed to include a central coolant passage and a contoured radial coolant passage that extends from the central passage to the vicinity of the cutting edge, and a radial coolant passage is formed by additive manufacturing to improve cooling effect.
By controlling the coolant flow mode, the cooling effect of the cutting edge is significantly improved, tool fatigue is reduced, and tool life is extended.
Smart Images
Figure CN120460780A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a rotary cutting tool, such as an end mill, having coolant passages therethrough. Background Art
[0002] End mills are used in the machine tool industry to cut a variety of materials, including metals, carbon fiber, and plastics. These tools typically operate at high cutting temperatures in the cutting zone. High temperatures can increase the removal rate of the material being cut and reduce the force required to cut the material. However, high cutting temperatures can also cause fatigue in these end mill cutting tools. Summary of the Invention
[0003] The present invention provides a rotary cutting tool, such as an end mill, having a through-coolant passage. The rotary cutting tool includes a rear shank portion, a cutting portion extending from the shank portion along a longitudinal axis and having a groove, at least one leading cutting edge, a central coolant passage extending along the longitudinal axis through the shank portion and the cutting portion, and radial coolant passages in fluid communication with the central coolant passage. The radial coolant passages extend from the central coolant passage to an outlet port adjacent to the leading cutting edge. Additional radial coolant passages may also be provided in the cutting portion, with the outlet ports adjacent to the groove.
[0004] One aspect of the present invention is to provide a rotary cutting tool comprising: a shank portion; a cutting portion extending from the shank portion along a longitudinal axis, the cutting portion comprising at least one groove and at least one peripheral cutting edge; at least one leading cutting edge at a front portion of the cutting portion; a central coolant channel extending within the shank portion; and at least one contoured radial coolant channel in fluid communication with the central coolant channel, the at least one contoured radial coolant channel extending radially outward from the central coolant channel to a radial coolant channel outlet port adjacent to at least one leading cutting edge or adjacent to at least one peripheral cutting edge. A plurality of contoured radial coolant channels can be directed toward a plurality of leading cutting edges, a plurality of contoured radial coolant channels can be directed toward a plurality of grooves and the peripheral cutting edge, or a plurality of groups of contoured radial coolant channels can be directed toward both the leading cutting edge and the peripheral cutting edge.
[0005] These and other aspects of the invention will become apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 is an isometric view of a rotary cutting tool having coolant passages therethrough according to an embodiment of the present invention.
[0007] Figure 2 yes Figure 1An isometric view of a rotary cutting tool of FIG. 1 , wherein the outer surface of the tool is shown in dashed lines and the internal coolant passages are shown in solid lines.
[0008] Figure 3 yes Figure 1 Side view of a rotary cutting tool.
[0009] Figure 4 It passes through Figure 3 A side cross-sectional view of the rotary cutting tool taken at section 4-4.
[0010] Figure 5 yes Figure 1 Front view of the rotary cutting tool.
[0011] Figure 6 yes Figure 1 Rear end view of the rotary cutting tool.
[0012] Figure 7 It passes through Figure 3 Section 7-7 is a cross-sectional view of the rotary cutting tool.
[0013] Figure 8 It passes through Figure 3 A cross-sectional view of the rotary cutting tool taken at section 8-8.
[0014] Figure 9 It passes through Figure 3 A cross-sectional view of the rotary cutting tool taken at section 9-9.
[0015] Figure 10 It passes through Figure 3 A cross-sectional view of the rotary cutting tool taken at section 10-10.
[0016] Figure 11 It passes through Figure 3 A cross-sectional view of the rotary cutting tool taken at section 11-11.
[0017] Figure 12 It shows Figure 1 Isometric view of the central coolant channel and radial coolant channels of a rotary cutting tool.
[0018] Figure 13 yes Figure 12 Close-up view of a portion of.
[0019] Figure 14 is an isometric view of a radial coolant passage having an outlet port opening with a contoured end, according to an embodiment of the present invention.
[0020] Figure 15is an isometric view of a rotary cutting tool having coolant passages therethrough according to another embodiment of the present invention.
[0021] Figure 16 yes Figure 15 An isometric view of a rotary cutting tool of FIG. 1 , wherein the outer surface of the tool is shown in dashed lines and the internal coolant passages are shown in solid lines.
[0022] Figure 17 yes Figure 15 Side view of a rotary cutting tool.
[0023] Figure 18 It passes through Figure 17 A side cross-sectional view of the rotary cutting tool taken at section 18-18.
[0024] Figure 19 yes Figure 15 Front view of the rotary cutting tool.
[0025] Figure 20 yes Figure 15 Rear end view of the rotary cutting tool.
[0026] Figure 21 It shows Figure 15 Isometric view of the central coolant channel and radial coolant channels of a rotary cutting tool. DETAILED DESCRIPTION
[0027] The rotary cutting tool of the present invention solves the above-mentioned problem by providing a tool that can allow the use of controlled coolant fluid flow to increase the cooling of the cutting edge during operating conditions. As used herein, the term "fluid" can refer to water, oil or other liquids and / or gases that can pass through the rotary cutting tool.
[0028] refer to Figure 1-4 , a rotary cutting tool 10, such as an end mill, includes a shank portion 20 having a rear shank face 22 and a cutting portion 30 extending forward from the shank portion 20 along a longitudinal axis A. The shank portion 20 and the cutting portion 30 can be cylindrical in shape. The cutting portion 30 includes a groove 32 and a peripheral cutting edge 34. Although a spiral groove 32 is shown in the figure, it will be understood that any other suitable groove shape, such as a straight groove, can be used. The cutting portion 30 can include one, two, three, four, five or more grooves 32.
[0029] like Figure 1-5, the rotary cutting tool 10 may include a front cutting edge 36 that is constructed and arranged to cut material at the end face of the cutting portion 30 during operation of the rotary cutting tool 10. The end cutting edges 36 may extend radially outward from the longitudinal axis A to the radially outermost surface of the cutting portion 30. An undercutting rake surface 35 extends axially rearward from each end cutting edge 36. The cutting portion may include one, two, three, four, five, or more front cutting edges.
[0030] like Figure 2 and 4 As shown in FIG, the shank portion 20 may include a central coolant passage 40 extending through the interior of the shank portion 20 along the longitudinal axis A. The central coolant passage 40 extends through the shank portion 20 from a rear coolant passage inlet 42 located at the shank rear surface 22 and into the cutting portion 30 toward the front cutting edge 36. The central coolant passage 40 may be cylindrical in shape or any other suitable shape. Figure 4 and 6 As shown in FIG, the central coolant passage 40 extends to a coolant manifold 44 located in the cutting portion 30 .
[0031] The central coolant passage 40 is constructed and arranged to receive coolant fluid during operation of the rotary cutting tool 10, which flows through the central coolant passage 40 to the coolant manifold 44. The central coolant passage 40 may be constructed and arranged to receive coolant fluid from a fluid source (not shown).
[0032] like Figure 2 、 12 As shown in FIG. 1 and FIG. 13 , contoured radial coolant passages 50 are in fluid communication with the inner central coolant passage 40. Each contoured radial coolant passage 50 begins at a radial coolant passage inlet port 51 located adjacent the central coolant passage 40 and the coolant manifold 44, and terminates at a radial coolant passage outlet port 52. The contoured radial coolant passages 50 are also Figure 7-11 , shown in cross-section at different axial positions along the length of the cutting portion 30. Figure 7 The coolant manifold 44 is shown, Figure 8 The coolant channel inlet port 51 is shown, Figure 9 and Figure 10 The contoured radial coolant passages 50 are shown, and Figure 11 The coolant passage outlet port 52 is shown.
[0033] As used herein, the term "radial" when referring to coolant channels means that the channels extend in a direction having a component in a radial direction extending perpendicularly outward from the central longitudinal axis A. The term "contoured" when referring to radial coolant channels means that at least a portion of the channel extends in a non-linear or non-straight direction along its flow path length and / or at least a portion of the channel has a non-uniform cross-section as the channel extends along its length from its inlet port to its outlet port.
[0034] Figure 1 、 2 5 show radial coolant passage outlet ports 52 located adjacent the leading cutting edge 36 and directed radially and axially toward the undercut rake face 35 at the leading end of the cutting portion 30. A protruding leading coolant delivery face 37 is provided between adjacent leading cutting edges 36, and one of the radial coolant passage outlet ports 52 extends through the protruding leading coolant delivery face. Each leading cutting edge 36 has a rear face 38 extending axially rearwardly from the leading cutting edge 36. Figure 1 and 5 As further shown in FIG. 3 , an undercut rake face 35 , a protruding front coolant delivery face 37 , and a rear face 38 intersect the groove 32 .
[0035] like Figure 12 and 13 , each contoured radial coolant passage 50 and outlet port 52 defines a coolant flow direction C that can be controlled to provide improved cooling of the leading cutting edge 36, as described more fully below. Figure 13 As further shown in FIG. 5 , each radial coolant passage outlet port 52 has an outlet length L and an outlet width W, the dimensions of which are described more fully below. Figure 8 As shown, each coolant channel inlet port 51 has an inlet length L' and an inlet width W'. The shape of each contoured coolant channel 50 can vary over its length. For example, as the contoured coolant channel 50 extends from its inlet port 51 to its outlet port 52, L can increase compared to L' and W can decrease compared to W', thereby producing a flat nozzle effect to cover more cutting edge length. Each contoured radial coolant channel 50 can have a first cross-sectional area aspect ratio L':W' adjacent the radial coolant channel inlet port 51, which transitions to a second cross-sectional area aspect ratio L:W adjacent the radial coolant channel outlet port 52, and the second cross-sectional area aspect ratio L:W can be greater than the first cross-sectional area aspect ratio L':W'. Therefore, the aspect ratio L:W can be greater than the aspect ratio L':W', that is, L:W>L':W'.
[0036] The radial coolant channel outlet ports may be slot-shaped, teardrop-shaped, circular, or may include another suitable cross-sectional shape. The outlet length L measured in the cross-sectional plane of each outlet port may be longer than the outlet width W measured in the cross-sectional plane. The outlet width W may vary, for example, as Figure 14 , where the radius R1 at one end of the outlet port 52 is greater than the radius R2 at the opposite end of the outlet port, thereby providing a teardrop shape. The outlet length L can generally be in the range of 0.2 to 5 mm, for example, 0.3 to 3 mm, or 0.5 to 2 mm. The outlet width W can generally be in the range of 0.05 to 4 mm, for example, 0.1 to 3 mm, or 0.2 to 2 mm. The ratio of outlet length to outlet width L:W can generally be in the range of 1:1 to 30:1, for example, 2:1 to 20:1, or 3:1 to 10:1.
[0037] The cross-sectional area of each outlet port 52 can be smaller than the cross-sectional area of the inlet 51 of each contoured radial coolant channel, such as at the intersection with the central coolant channel. The reduction in the cross-sectional area of the contoured radial coolant channel can cause an increase in the velocity of the coolant fluid as it flows through the contoured radial coolant channel. The fluid velocity can increase by a factor of zero to 500%, such as 1.5 to 300%, or 2 to 200%, between the inlet of each radial coolant channel and its outlet port.
[0038] The shape of each radial passage outlet port can be constructed and arranged to expand or disperse the coolant fluid as it exits the outlet port.The coolant fluid can disperse in a direction parallel or substantially parallel to the peripheral cutting edge 34 or the leading cutting edge 36.
[0039] Figure 1-14 The contoured radial coolant passages shown in the embodiment of FIG. 1 and described below Figure 15-21The profiled radial coolant channels in the embodiment shown in the figure can have a curved shape that promotes a coolant flow pattern during operation of the rotary cutting tool. For example, in the embodiment shown, the profiled radial coolant channels have a swept shape, wherein their outlet ports are circumferentially offset from their inlet ports. In the embodiment shown, the swept profiled radial coolant channels have outlet ports that are circumferentially offset from their inlet ports in a direction opposite to the direction of rotation of the cutting tool when the cutting tool rotates about its central longitudinal axis A. Thus, during rotation of the cutting tool, the inlet port 51 of each profiled radial coolant channel 50 can circumferentially lead the outlet port 52 of the profiled radial coolant channel 50. Alternatively, the sweep direction can be reversed, i.e., each inlet port 51 can circumferentially lag behind the outlet port 52. Depending on the specific configuration of the rotary cutting tool, such as the number of its end cutting edges, any suitable circumferential offset distance can be used, such as at least 2°, or at least 5°, or at least 10°, and at most 15°, or at most 20°, or at most 30° or more.
[0040] Figure 15-21 A rotary cutting tool 110 according to another embodiment of the present invention is shown. In this embodiment, the rotary cutting tool 110 includes additional contoured radial coolant passages positioned adjacent the groove 32, as described more fully below.
[0041] The rotary cutting tool 110 includes an internal central coolant passage 140 and a coolant passage inlet 142 located in the shank portion 20 and extending into the cutting portion 30. Figure 16 and 21 As shown most clearly in FIG, a plurality of contoured radial coolant passages 150A, 150B, 150C, and 150D are disposed at various locations along the central coolant passage 140. FIG.
[0042] A plurality of first contoured radial coolant channels 150A extend radially from the central coolant channel 140 at a first radial coolant channel inlet 151 A at a first location along the longitudinal axis A of the rotary cutting tool 110. Each first contoured radial coolant channel 150A terminates at a first radial coolant channel outlet port 152A.
[0043] A plurality of second contoured radial coolant channels 150B extend radially from the central coolant channel 140 via second radial coolant channel inlets 151B at a second location along the longitudinal axis A of the rotary cutting tool 110. Each second contoured radial coolant channel 150B terminates in a second radial coolant channel outlet port 152B.
[0044] A plurality of third contoured radial coolant channels 150C extend radially from the central coolant channel 140 via third radial coolant channel inlets 151C at a third location along the longitudinal axis A of the rotary cutting tool 110. Each third contoured radial coolant channel 150C terminates at a third radial coolant channel outlet port 152C.
[0045] like Figure 16 and 21 As further shown in FIG. 1 , a fourth set of contoured radial coolant channels 150D is provided. A plurality of fourth contoured radial coolant channels 150D extend from the coolant manifold 144, which is in fluid communication with the central coolant channel 140. Each fourth contoured radial coolant channel 150D terminates at a fourth radial coolant channel outlet port 152D. Figure 15 and 19 As shown in FIG, each fourth radial coolant passage outlet port 152D is similar to Figure 1-13 The embodiment shown in FIG. 1 extends through the corresponding protruding front coolant conveying surface 37 .
[0046] Thus, the first, second, and third contoured radial coolant channels 150A, 150B, and 150C convey coolant fluid toward the peripheral cutting edge 34 at different axial positions in the groove 32, while the fourth contoured radial coolant channel 150D conveys coolant fluid toward the leading cutting edge 36.
[0047] The number of contoured radial coolant channels may be equal to the number of grooves 32, e.g. Figure 1-13 Alternatively, the number of contoured radial coolant channels may be greater than the number of grooves 32, e.g. Figure 15-21 As shown in the embodiments.
[0048] The contoured radial coolant passages 50 and 150D can be constructed and arranged so that the coolant fluid covers a relatively large area of the leading cutting edge 36, for example, at least 5% of the leading cutting edge 36, such as at least 10% or at least 20% of the leading cutting edge 36. The contoured radial coolant passages 150A, 150B, and 150C can be constructed and arranged so that the coolant fluid covers a relatively large area of the peripheral cutting edge 34 of the groove 32 during operation of the rotary cutting tool, for example, at least 2% of the peripheral cutting edge 34, such as at least 5%, or at least 10%, or at least 20% of the peripheral cutting edge 34.
[0049] The rotary cutting tools 10 and 110 can be manufactured using any suitable manufacturing technique, such as additive manufacturing. The entire rotary cutting tool can be manufactured using additive manufacturing, or only a portion of the cutting portion 30 can be manufactured using additive manufacturing. Non-limiting examples of additive manufacturing techniques include binder jetting, directed energy deposition (DED), material extrusion, material jetting, powder bed fusion, sheet lamination, and / or photopolymerization curing.
[0050] Using additive manufacturing for the entire rotary cutting tool or cutting portion can facilitate the formation of contoured radial coolant channels along the length of the central coolant channel. In some non-limiting embodiments, additive manufacturing can be used to form the cutting portion proximal to the end face, such as the last 3-5 mm of the rotary cutting tool proximal to the end face, by adding to a solid carbide blank including the central coolant channel. Thus, additive manufacturing can be selectively used to form contoured radial coolant channels for flow communication with the pre-formed central coolant channel.
[0051] As used herein, the terms "including," "containing," and the like, in the context of this application, should be understood as being synonymous with "comprising," and are therefore open-ended and do not exclude the presence of additional undescribed or unlisted elements, materials, phases, or method steps. As used herein, "consisting of," in the context of this application, should be understood to exclude the presence of any unspecified elements, materials, phases, or method steps. As used herein, "consisting essentially of," in the context of this application, should be understood to include the specified elements, materials, phases, or method steps, if applicable, and also include any unspecified elements, materials, phases, or method steps that do not materially affect the basic or novel characteristics of the invention.
[0052] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.
[0053] Likewise, it should be understood that any numerical range recited herein is intended to include all subranges contained therein. For example, a range of "1 to 10" is intended to include all subranges between (and including) the stated minimum value of 1 and the stated maximum value of 10, i.e., having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.
[0054] In this application, unless specifically stated otherwise, the use of the singular includes the plural and the plural encompasses the singular. Additionally, in this application, the use of "or" means "and / or" unless explicitly stated otherwise, even though "and / or" may be explicitly used in certain circumstances. In this application and the appended claims, the articles "a," "an," and "the" include plural referents unless expressly and obviously limited to one referent.
[0055] While specific embodiments of the present invention have been described above for purposes of illustration, it will be apparent to those skilled in the art that numerous changes may be made in the details of the invention without departing from the invention as defined in the appended claims.
Claims
1. A rotary cutting tool comprising: handle portion; a cutting portion extending from the shank portion along a longitudinal axis, the cutting portion comprising at least one groove and at least one peripheral cutting edge; at least one leading cutting edge at a front portion of the cutting portion; a central coolant passage extending within the shank portion; as well as At least one contoured radial coolant channel is in fluid communication with the central coolant channel, the at least one contoured radial coolant channel extending radially outward from the central coolant channel to a radial coolant channel outlet port adjacent the at least one leading cutting edge or adjacent the at least one peripheral cutting edge.
2. The rotary cutting tool of claim 1 , comprising a plurality of said leading cutting edges, contoured radial coolant channels and radial coolant channel outlet ports, and each radial coolant channel outlet port is directed toward a respective one of said leading cutting edges.
3. The rotary cutting tool of claim 2, wherein each of the leading cutting edges intersects an undercutting rake surface, and each of the contoured radial coolant passages is constructed and arranged to deliver coolant fluid toward one of the leading cutting edges.
4. The rotary cutting tool according to claim 3 further includes a front coolant delivery surface, which is circumferentially located between adjacent front cutting edges of the front cutting edges, wherein one of the radial coolant channel outlet ports extends through the front coolant delivery surface and is constructed and arranged to deliver the coolant fluid toward the adjacent front cutting edge.
5. The rotary cutting tool according to claim 1 comprises a plurality of grooves, peripheral cutting edges, contoured radial coolant channels and radial coolant channel outlet ports, and each radial coolant outlet port is located in one of the grooves and points to a corresponding one of the peripheral cutting edges.
6. The rotary cutting tool of claim 5, wherein each of the contoured radial coolant channels is constructed and arranged to deliver coolant fluid from a radial coolant channel outlet port thereof toward the peripheral cutting edge.
7. The rotary cutting tool of claim 6, further comprising a plurality of sets of contoured radial coolant passages located at different axial positions along the longitudinal axis of the cutting portion.
8. The rotary cutting tool according to claim 7, comprising: a first set of contoured radial coolant channels positioned along the longitudinal axis, the first set of contoured radial coolant channels constructed and arranged to deliver coolant fluid toward the peripheral cutting edge; as well as A second set of contoured radial coolant channels is positioned axially forward of the first set of radial coolant channels along the longitudinal axis, the second set of contoured radial coolant channels being constructed and arranged to deliver coolant fluid toward the peripheral cutting edge.
9. The rotary cutting tool of claim 8, further comprising a third set of contoured radial coolant channels positioned axially forward of the second set of radial coolant channels along the longitudinal axis.
10. The rotary cutting tool of claim 1, wherein the at least one groove is helical.
11. The rotary cutting tool according to claim 1 , comprising: a plurality of leading cutting edges, and a first plurality of contoured radial coolant passages and radial coolant passage outlet ports, wherein each radial coolant outlet port of the first plurality of radial coolant outlet ports is directed toward a respective one of the leading cutting edges; as well as a plurality of grooves and peripheral cutting edges, and a second plurality of contoured radial coolant passages and radial coolant passage outlet ports, wherein each radial coolant outlet port of the second plurality of radial coolant outlet ports is located in one of the grooves and points toward a corresponding one of the peripheral cutting edges.
12. The rotary cutting tool of claim 1, wherein the at least one contoured radial coolant channel extends forwardly along the longitudinal axis from an inlet adjacent the central coolant channel to the radial coolant channel outlet port.
13. The rotary cutting tool of claim 1, wherein the at least one contoured radial coolant channel includes a non-linear curvature along the length of the contoured radial coolant channel.
14. The rotary cutting tool of claim 13, wherein the non-linear portion extends along the entire length of the contoured radial coolant passage.
15. The rotary cutting tool of claim 13, wherein the at least one contoured radial coolant channel comprises a non-uniform cross-section along the length of the contoured radial coolant channel.
16. The rotary cutting tool of claim 1, wherein the at least one contoured radial coolant channel comprises a non-uniform cross-section along the length of the contoured radial coolant channel.
17. The rotary cutting tool of claim 1, wherein the at least one contoured radial coolant channel has a curved swept shape, wherein the radial coolant channel outlet port is circumferentially offset from a radial coolant channel inlet port of the contoured radial coolant channel.
18. The rotary cutting tool of claim 17, wherein the radial coolant passage outlet port is circumferentially offset from the radial coolant passage inlet port in a direction opposite to a rotational cutting direction of the rotary cutting tool.
19. The rotary cutting tool of claim 1 , wherein the at least one contoured radial coolant channel comprises a first cross-sectional area aspect ratio adjacent a radial coolant channel inlet port of the contoured radial cooling channel, the first cross-sectional area aspect ratio transitioning to a second cross-sectional area aspect ratio adjacent the radial coolant channel outlet port, and the second cross-sectional area aspect ratio being greater than the first cross-sectional area aspect ratio.
20. The rotary cutting tool of claim 1, wherein the at least one radial coolant passage outlet port comprises a cross-sectional outlet length that is greater than a cross-sectional outlet width.
21. The rotary cutting tool of claim 1, wherein the at least one radial coolant passage outlet port has a teardrop shape.
22. The rotary cutting tool of claim 1, wherein the inlet cross-sectional area of the radial coolant channel inlet port of the at least one contoured radial coolant channel is greater than the outlet cross-sectional area of the radial coolant channel outlet port.
23. The rotary cutting tool of claim 1, wherein the rotary cutting tool is an end mill.