WO2008090301A1 - Milling cutter manufacturing method - Google Patents

Milling cutter manufacturing method Download PDF

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Publication number
WO2008090301A1
WO2008090301A1 PCT/GB2007/004308 GB2007004308W WO2008090301A1 WO 2008090301 A1 WO2008090301 A1 WO 2008090301A1 GB 2007004308 W GB2007004308 W GB 2007004308W WO 2008090301 A1 WO2008090301 A1 WO 2008090301A1
Authority
WO
WIPO (PCT)
Prior art keywords
tooth
milling cutter
grinding
relief
face
Prior art date
Application number
PCT/GB2007/004308
Other languages
French (fr)
Inventor
Mark Kirby
Christopher Peter Ralph Hill
Original Assignee
Rolls-Royce Plc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rolls-Royce Plc filed Critical Rolls-Royce Plc
Priority to JP2009546803A priority Critical patent/JP5745769B2/en
Priority to EP07824537.0A priority patent/EP2121243B1/en
Priority to US12/448,696 priority patent/US8286536B2/en
Publication of WO2008090301A1 publication Critical patent/WO2008090301A1/en
Priority to IL199638A priority patent/IL199638A/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B3/00—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools
    • B24B3/02—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools of milling cutters
    • B24B3/06—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools of milling cutters of face or end milling cutters or cutter heads, e.g. of shank type
    • B24B3/065—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools of milling cutters of face or end milling cutters or cutter heads, e.g. of shank type end milling cutters with rounded ends
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B23C5/02—Milling-cutters characterised by the shape of the cutter
    • B23C5/10—Shank-type cutters, i.e. with an integral shaft
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/24—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass dies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/02—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements
    • B24B19/04—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements for fluting drill shanks
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T407/00—Cutters, for shaping
    • Y10T407/19—Rotary cutting tool
    • Y10T407/1946—Face or end mill
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T407/00—Cutters, for shaping
    • Y10T407/19—Rotary cutting tool
    • Y10T407/1952—Having peripherally spaced teeth
    • Y10T407/1956—Circumferentially staggered
    • Y10T407/1958—Plural teeth spaced about a helix
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T82/00—Turning
    • Y10T82/10—Process of turning

Definitions

  • This invention relates to a method of manufacturing a milling cutter for the milling of so-called exotic materials such as titanium alloys, stainless steel, nimonic alloys etc, which are notoriously difficult to machine, and to a milling cutter per se.
  • a basic object of the present invention seeks to provide an improved method of manufacturing a milling cutter, and to an improved milling cutter.
  • a method of manufacturing a milling cutter having a cutting head and a coaxial integral shank for mounting a chuck or arbour of a machine tool comprising the steps of : -
  • a milling cutter comprising a shank and a cutting head, the cutting head having a plurality of ⁇ 500 helical flutes, with a lead end of each flute provided with a radius, with each tooth having a minimum tooth wedge angle of approximately 60° measured between the leading face of a tooth and a relief rake face of that tooth.
  • the resulting radiussed, and relieved multi-tooth, multi- flute form of the milling cutter manufactured in accordance with the first aspect of the invention produces a substantially stronger tooth than that of for example the prior art deburring tool, and has been found, in comparison to conventional milling cutters, in milling identical exotic materials, to improve cutting capability by a significant factor, resulting in lower manufacturing costs for components and a reduced machine tool investment requirement , and is equally useable for both roughing and finishing.
  • the relief face produced by the secondary grinding operation comprises a primary relief rake facet and a secondary relief rake facet, which extends from an end of the primary relief rake facet distal from the tooth tip, resulting in a radiussed, double ratchet tooth style allowing optimisation of critical features.
  • the primary and secondary facets are planar, the primary relief rake facet being ground at a first angle, and the secondary relief rake facet being ground at a second angle greater than the first .
  • the relief face produced by the second grinding operation is of eccentric or convex profile, resulting in increased strength compared with a planar profile.
  • Each flute has a double ratchet tooth form comprising a primary relief rake facet and a contiguous secondary relief rake facet .
  • the primary and secondary facets are planar, the primary relief rake facet being ground at a first angle, and the secondary relief rake facet being ground at a second angle greater than the first .
  • the primary relief rake facet has a clearance angle of approximately 5° to 7°.
  • the secondary relief rake facet has a clearance angle of approximately 10° to 15°.
  • Each flute has a relief rake face of eccentric or convex profile, providing increased strength compared with a planar profile .
  • the leading face of each tooth has a positive radial rake .
  • the finished milling cutter has ⁇ 60 flutes.
  • a 16mm diameter milling cutter has 8-20 flutes with a lmm radius, but clearly the maximum number of flutes that it is possible to produce is dependent upon the required milling cutter diameter.
  • the wedge angle of each tooth is preferably greater than approximately 60° but less than approximately 90°.
  • the wedge angle of each tooth is approximately 90° less the primary relief rake angle, and less the secondary relief rake angle .
  • Figure 1 shows a portion of a first embodiment of milling cutter in accordance with the first and second aspects of the invention
  • Figure 2 is an enlarged view of one of the teeth shown in Figure 1;
  • Figure 2A corresponds to Figure 2 , but shows a second embodiment of milling cutter,-
  • Figure 3 shows the first grinding operation forming the flutes of the first embodiment
  • Figure 4 is an enlargement of the ringed portion indicated in Figure 3 ;
  • Figure 4A shows the grinding of the eccentric relief face of the second embodiment
  • Figure 5 is an enlargement of Figure 3 showing how both the first and second grinding operations are effected
  • Figures 6, 7, 8 and 9 show progressively how the third grinding operation is effected to produce the radius
  • Figure 10 is a side elevation of a finished milling cutter in accordance with the first embodiment; and Figure 11 is an isometric view of the cutter of Figure 10.
  • a finished milling cutter 1 in accordance with a first embodiment is illustrated in Figures 6 and 7.
  • the cutter 1 has a cutting head 2 and a coaxial integral shank 3 for securing in a chuck or arbour of a machine tool for rotation about an axis X.
  • the cutting head 2 has a plurality (e.g. thirty) helical flutes 5 extending from a leading end 6 of the head 2, to a trailing end 7 of the head 2.
  • Each flute 5 has a tooth 8 provided with a leading face 9 and a rear face 10, Figure 1.
  • the leading face 9 faces the direction of rotation of the cutter 1 when in use and has a cutting tip 4.
  • the cutting tip 4 of each of the teeth 8 lie on the circumference of a pitch circle having a diameter D, Figure 3.
  • the leading face 9 has a positive radial rake angle 0°.
  • the radial rake angle 0 is the angle that the inclined leading face 9 makes with a radial line Y, Figure 2, extending from the tool axis X to the tip 4 of a tooth 8.
  • each tooth 8 also has a primary relief rake facet 11 which, in the example illustrated, is planar.
  • the primary facet 11 comprises a land which extends rearwardly from the tip of the leading edge 9 of the tooth 8.
  • the primary facet 11 is inclined at an angle to a tangent Z extending from the pitch circle at the tooth tip 4. This angle is referred to as the primary clearance angle ⁇ ° and is of the order of approximately 5° to approximately 7°.
  • a secondary relief rake facet 12 extends from the primary facet 11 to the rear face 10.
  • the secondary facet 12 is inclined at a secondary clearance angle ⁇ to a tangent Z extending from the pitch circle at the tooth tip 4.
  • the secondary clearance angle a is of the order of approximately 10° to approximately 15° in the preferred embodiment of the present invention.
  • each tooth 8 also has a tertiary clearance angle ⁇ , shown in Figure 2 , which is the angle between the rear face 10 and the tangent Z extending from the pitch circle at the tooth tip 4.
  • the primary, secondary and tertiary clearance angles are used to define the geometry of the double ratchet tooth form. By controlling these angles the geometry of the tooth can be defined in the manufacturing process.
  • the wedge angle W is shown in Figure 1 and is defined by the equation
  • each tooth 8 in the preferred embodiment of the present invention has a wedge angle W defined between its leading face 9 and the primary relief rake facet 11, of approximately 76°.
  • the leading face 9 of a trailing tooth 8, and a rear face 10 of the immediately preceding tooth 8 diverge and define, together with a flute base 13, a gullet 14.
  • the gullet 14 is provided for swarf removal purposes and is designed so that in use the swarf generated during cutting is carried away without clogging the cutter. This is achieved by controlling the pitch of the teeth, the depth of the gullet 14 and the width of the land of the primary facet 11.
  • the distance between the teeth 8 is measured as an arc length CP along the circumference of the pitch circle.
  • D is the diameter of the pitch circle and N is the number of teeth.
  • the method, in accordance with the first aspect of the invention, of manufacturing the cutter 1 in accordance with the second aspect is illustrated in Figures 2 to 4 and is basically a three-stage grinding operation using three grinding wheels of different peripheral profiles.
  • a first grinding wheel 15 has a generally frusto-conical profile peripheral area 16 with an edge 17 of profile required for the flute base 13, and is rotated about an axis 18 extending generally transversely to axis 4 of the milling cutter 1.
  • the periphery area 16 of the first grinding wheel 15 grinds individual flutes 5 into the outer periphery of a cutter blank from the leading end 6 towards the shank 3, specifically grinding:- (i) the positive rake angle on the leading face 9 (of a trailing tooth 8) , simultaneously with
  • a peripheral edge 19 of a second grinding wheel 20, of rectangular profile is also rotatable about axis 18 generally transversely of the milling cutter axis 4 and is used to grind firstly the primary relief rake facet 11 and then, after a change of grinding angle, the secondary relief rake facet 12 to produce a milling cutter 1 with a plurality of helical flutes 5 each having a double ratchet tooth form, in a two-stage grinding operation.
  • a peripheral edge 21 of a third grinding wheel 22 is used to grind a radius 23 onto the end of each flute 5, this grinding operation commencing at the lead end 24 of each flute 5 and advancing away from that end toward the shank 3 of the cutter 7.
  • the double ratchet tooth form embodiment of milling cutter results in a cutting tool having the required strength and durability.
  • iAn alternative relief face 12A is illustrated in the second embodiment of milling cutter IA, shown in Figure 2A, where the primary and secondary planar relief faces 11 and 12 of the first embodiment (see Figure 2) are replaced by a single eccentric or convex relief face 12A ground at an average eccentric relief between approximately 2° and approximately 15° .
  • the manner of grinding eccentric relief face 12A is illustrated in Figure 4A, using a peripheral edge 19A of a grinding wheel 2OA and advancing from the rear of each flute 5A to the leading end of each flute 5A. Tests have shown that metal removal rates, for cutters in accordance with the present invention, are increased not marginally but by up to 20 times.
  • the cutters have the ability to carry away swarf and resist the degredating effects of heat when machining exotic materials.
  • the swarf produced by a milling cutter design in accordance with the present invention is in the form of short, stubby chips as opposed to continuous spirals as produced by conventional cutting tools.
  • the consistently short and stubby chips are also clean because cutting does not reach such high temperatures so as to cause significant oxidation.
  • the regular chip size of the swarf makes them suitable, for packing into cans and consolidating by hot isostatic pressing HIP.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Milling Processes (AREA)

Abstract

A method of manufacturing a milling cutter having a cutting head and a coaxial integral shank comprising the steps of grinding, in a first grinding operation, a plurality of helical flutes (5) into the outer periphery of a cutter blank from a lead end (24) using a peripheral area (16) of a first grinding wheel (15) generally of frusto-conical profile and rotatable about an axis (18) generally transversely of the milling cutter axis (1), which peripheral area (16) produces, simultaneously, the following three features: a leading face (9) of a trailing tooth; a rear face (10) on an adjacent preceding tooth; and a swarf removal gullet (13) having divergent sides, grinding, in a second grinding operation, and using a peripheral edge (19) of a second grinding wheel (20), a relief face (11), which extends rearwardly from a leading end of a tooth tip, resulting in a minimum tooth wedge angle of approximately 60°, and grinding, in a third grinding operation, a radius (23) on the end of each flute. The invention also includes a milling cutter (1).

Description

MILLING CUTTER MANUFACTURING METHOD
This invention relates to a method of manufacturing a milling cutter for the milling of so-called exotic materials such as titanium alloys, stainless steel, nimonic alloys etc, which are notoriously difficult to machine, and to a milling cutter per se.
The aerospace industry makes extensive use of titanium alloys etc, and, in common with other industries, continually seek to reduce costs of manufacture through either outsourcing to cheaper economies or increasing production.
Materials such as titanium, stainless and nimonic alloys are at the outer boundaries of milling capability and challenge current capabilities to improve productivity. Whilst grinding processes have been developed that have significantly improved productivity even in exotic materials, there are inevitably in some components features that are inaccessible to grinding wheels and hence cannot be shaped by grinding and which therefore still have to be machined. In other, light duty, spheres of metal processing, fine tooth pitched cutters are known but are predominantly used for deburring applications, such cutters usually being disposable. These are generally open toleranced tools, the tooth style for a burr being a single ratchet tooth form. Although this produces an inherently weak tooth form (having a wedge angle of approximately 50°), it is of little consequence in deburring operations, but these generally very fine pitched cutters will not stand up to the rigours of machining operations such as milling, particularly of exotic material, with the capability and consistency demanded, nor lend themselves to re-sharpening for repeated use. Whilst it is well known that metal removal rate increases with the number of teeth on a cutter, there are of course limitations of how many teeth can be produced in a given cutting tool diameter as well as sharpening those teeth using conventional grinding techniques . A basic object of the present invention seeks to provide an improved method of manufacturing a milling cutter, and to an improved milling cutter.
According to a first aspect of the invention, there is provided a method of manufacturing a milling cutter having a cutting head and a coaxial integral shank for mounting a chuck or arbour of a machine tool, comprising the steps of : -
(i) grinding, in a first grinding operation, a plurality of helical flutes into the outer periphery of a cutter blank from a lead end of the blank distal from the shank towards the shank, using a peripheral area of a first grinding wheel generally of frusto-conical profile and rotatable about an axis generally transversely of the milling cutter axis, which peripheral area produces, simultaneously, the following three features : - a leading face of a trailing tooth; a rear face on an adjacent preceding tooth; and a swarf removal gullet, of profile corresponding to that of the peripheral area of the first grinding wheel, having divergent sides defined between the leading face of a trailing tooth and the rear face of an adjacent preceding tooth;
(ii) grinding, in a second grinding operation, and using a peripheral edge of a second grinding wheel of rectangular profile, and rotatable about an axis generally transversely of the milling cutter axis, a relief face which extends rearwardly from a leading end of a tooth tip, resulting in a minimum tooth wedge angle of approximately 60° measured between the leading face of a tooth to the relief face of that tooth; and
(iii) grinding, in a third grinding operation, and using a peripheral edge of a third grinding wheel , a radius on the end of each flute by grinding along each flute from the lead end of each flute towards the shank of the cutter. According to a second aspect of the invention, of independent significance, there is provided a milling cutter comprising a shank and a cutting head, the cutting head having a plurality of <500 helical flutes, with a lead end of each flute provided with a radius, with each tooth having a minimum tooth wedge angle of approximately 60° measured between the leading face of a tooth and a relief rake face of that tooth.
The resulting radiussed, and relieved multi-tooth, multi- flute form of the milling cutter manufactured in accordance with the first aspect of the invention produces a substantially stronger tooth than that of for example the prior art deburring tool, and has been found, in comparison to conventional milling cutters, in milling identical exotic materials, to improve cutting capability by a significant factor, resulting in lower manufacturing costs for components and a reduced machine tool investment requirement , and is equally useable for both roughing and finishing.
The relief face produced by the secondary grinding operation, comprises a primary relief rake facet and a secondary relief rake facet, which extends from an end of the primary relief rake facet distal from the tooth tip, resulting in a radiussed, double ratchet tooth style allowing optimisation of critical features.
The departure from conventional grinding techniques to the first aspect/method permits the ready formation of the radiussed, double ratchet tooth embodiment, whereas conventional radius grinding of one tooth would wipe out the succeeding tooth, thus limiting the scope of increasing the number of teeth.
The primary and secondary facets are planar, the primary relief rake facet being ground at a first angle, and the secondary relief rake facet being ground at a second angle greater than the first .
The relief face produced by the second grinding operation is of eccentric or convex profile, resulting in increased strength compared with a planar profile. Each flute has a double ratchet tooth form comprising a primary relief rake facet and a contiguous secondary relief rake facet .
The primary and secondary facets are planar, the primary relief rake facet being ground at a first angle, and the secondary relief rake facet being ground at a second angle greater than the first .
The primary relief rake facet has a clearance angle of approximately 5° to 7°. The secondary relief rake facet has a clearance angle of approximately 10° to 15°.
Each flute has a relief rake face of eccentric or convex profile, providing increased strength compared with a planar profile . The leading face of each tooth has a positive radial rake .
The finished milling cutter has <60 flutes. For example, a 16mm diameter milling cutter has 8-20 flutes with a lmm radius, but clearly the maximum number of flutes that it is possible to produce is dependent upon the required milling cutter diameter.
The wedge angle of each tooth is preferably greater than approximately 60° but less than approximately 90°.
In the double ratchet embodiment, the wedge angle of each tooth is approximately 90° less the primary relief rake angle, and less the secondary relief rake angle .
The wedge angle of each tooth is approximately 76°. The two aspects of the present invention will now be described by way of examples only with reference to the accompanying drawings, in which: -
Figure 1 shows a portion of a first embodiment of milling cutter in accordance with the first and second aspects of the invention;
Figure 2 is an enlarged view of one of the teeth shown in Figure 1; Figure 2A corresponds to Figure 2 , but shows a second embodiment of milling cutter,-
Figure 3 shows the first grinding operation forming the flutes of the first embodiment; Figure 4 is an enlargement of the ringed portion indicated in Figure 3 ;
Figure 4A shows the grinding of the eccentric relief face of the second embodiment ;
Figure 5 is an enlargement of Figure 3 showing how both the first and second grinding operations are effected;
Figures 6, 7, 8 and 9 show progressively how the third grinding operation is effected to produce the radius;
Figure 10 is a side elevation of a finished milling cutter in accordance with the first embodiment; and Figure 11 is an isometric view of the cutter of Figure 10.
A finished milling cutter 1 in accordance with a first embodiment is illustrated in Figures 6 and 7. The cutter 1 has a cutting head 2 and a coaxial integral shank 3 for securing in a chuck or arbour of a machine tool for rotation about an axis X.
The cutting head 2 has a plurality (e.g. thirty) helical flutes 5 extending from a leading end 6 of the head 2, to a trailing end 7 of the head 2. Each flute 5 has a tooth 8 provided with a leading face 9 and a rear face 10, Figure 1. The leading face 9 faces the direction of rotation of the cutter 1 when in use and has a cutting tip 4. The cutting tip 4 of each of the teeth 8 lie on the circumference of a pitch circle having a diameter D, Figure 3. The leading face 9 has a positive radial rake angle 0°. The radial rake angle 0 is the angle that the inclined leading face 9 makes with a radial line Y, Figure 2, extending from the tool axis X to the tip 4 of a tooth 8. The angle 0 is up to approximately 12° in the preferred embodiment of the present invention, depending on the material being cut, and zero rake may be required for some materials . As shown in Figure 2, each tooth 8 also has a primary relief rake facet 11 which, in the example illustrated, is planar. The primary facet 11 comprises a land which extends rearwardly from the tip of the leading edge 9 of the tooth 8. The primary facet 11 is inclined at an angle to a tangent Z extending from the pitch circle at the tooth tip 4. This angle is referred to as the primary clearance angle θ° and is of the order of approximately 5° to approximately 7°.
A secondary relief rake facet 12, also planar in the example illustrated, extends from the primary facet 11 to the rear face 10. The secondary facet 12 is inclined at a secondary clearance angle α to a tangent Z extending from the pitch circle at the tooth tip 4. The secondary clearance angle a is of the order of approximately 10° to approximately 15° in the preferred embodiment of the present invention.
Alternatively however the primary relief rake facet and/or the secondary relief rake facet is/are not planar but is/are eccentric or convex, providing more material, and hence greater strength for each flute. Each tooth 8 also has a tertiary clearance angle σ, shown in Figure 2 , which is the angle between the rear face 10 and the tangent Z extending from the pitch circle at the tooth tip 4.
The primary, secondary and tertiary clearance angles are used to define the geometry of the double ratchet tooth form. By controlling these angles the geometry of the tooth can be defined in the manufacturing process.
By controlling the radial rake angle 0 and the primary, secondary and tertiary clearance angles a strong tooth is formed with a resultant wedge angle W, which can be optimised to suit materials which are notoriously difficult to cut.
The wedge angle W is shown in Figure 1 and is defined by the equation;
W = 90 - (ø-θ) Thus, each tooth 8 in the preferred embodiment of the present invention has a wedge angle W defined between its leading face 9 and the primary relief rake facet 11, of approximately 76°. The leading face 9 of a trailing tooth 8, and a rear face 10 of the immediately preceding tooth 8 diverge and define, together with a flute base 13, a gullet 14. The gullet 14 is provided for swarf removal purposes and is designed so that in use the swarf generated during cutting is carried away without clogging the cutter. This is achieved by controlling the pitch of the teeth, the depth of the gullet 14 and the width of the land of the primary facet 11.
The distance between the teeth 8 is measured as an arc length CP along the circumference of the pitch circle. The arc length CP between teeth 8 is defined by the equation; CP = πD/N
D is the diameter of the pitch circle and N is the number of teeth.
The width of the land is kept in the range 0.05CP-0.25CP and the depth of the gullet 14 is kept in the range 0.2CP- 0.5CP, where CP = πD/N.
The method, in accordance with the first aspect of the invention, of manufacturing the cutter 1 in accordance with the second aspect is illustrated in Figures 2 to 4 and is basically a three-stage grinding operation using three grinding wheels of different peripheral profiles.
In the first grinding operation, a first grinding wheel 15 has a generally frusto-conical profile peripheral area 16 with an edge 17 of profile required for the flute base 13, and is rotated about an axis 18 extending generally transversely to axis 4 of the milling cutter 1. As best seen in Figure 4, the periphery area 16 of the first grinding wheel 15 grinds individual flutes 5 into the outer periphery of a cutter blank from the leading end 6 towards the shank 3, specifically grinding:- (i) the positive rake angle on the leading face 9 (of a trailing tooth 8) , simultaneously with
(ii) a rear face 10 on an immediately preceding tooth 8, simultaneously with (iii) the base 13.
In the second grinding operation, a peripheral edge 19 of a second grinding wheel 20, of rectangular profile is also rotatable about axis 18 generally transversely of the milling cutter axis 4 and is used to grind firstly the primary relief rake facet 11 and then, after a change of grinding angle, the secondary relief rake facet 12 to produce a milling cutter 1 with a plurality of helical flutes 5 each having a double ratchet tooth form, in a two-stage grinding operation.
In the third grinding operation, a peripheral edge 21 of a third grinding wheel 22 is used to grind a radius 23 onto the end of each flute 5, this grinding operation commencing at the lead end 24 of each flute 5 and advancing away from that end toward the shank 3 of the cutter 7.
The double ratchet tooth form embodiment of milling cutter results in a cutting tool having the required strength and durability. iAn alternative relief face 12A is illustrated in the second embodiment of milling cutter IA, shown in Figure 2A, where the primary and secondary planar relief faces 11 and 12 of the first embodiment (see Figure 2) are replaced by a single eccentric or convex relief face 12A ground at an average eccentric relief between approximately 2° and approximately 15° . The manner of grinding eccentric relief face 12A is illustrated in Figure 4A, using a peripheral edge 19A of a grinding wheel 2OA and advancing from the rear of each flute 5A to the leading end of each flute 5A. Tests have shown that metal removal rates, for cutters in accordance with the present invention, are increased not marginally but by up to 20 times. This results in marked reduction not only of machining time but also of the number of machine tools required, providing further savings not only of capital costs but also of factory space. The cutters have the ability to carry away swarf and resist the degredating effects of heat when machining exotic materials. The swarf produced by a milling cutter design in accordance with the present invention is in the form of short, stubby chips as opposed to continuous spirals as produced by conventional cutting tools. The consistently short and stubby chips are also clean because cutting does not reach such high temperatures so as to cause significant oxidation. The regular chip size of the swarf makes them suitable, for packing into cans and consolidating by hot isostatic pressing HIP. The fact that the chips are highly deformed by the machining process also means a finegrained homogenous consolidated structure can be achieved using optimum HIP times and temperatures which promote high strength and tough mechanical properaties. This offers the further advantage that the regular clean chips from a multi- flute cutter in accordance with the present invention can be recycled and consolidated into now components.

Claims

1. A method of manufacturing a milling cutter (1, IA) having a cutting head (2) and a coaxial integral shank (3) for mounting in a chuck or arbour of a machine tool, comprising the steps of : -
(i) grinding, in a first grinding operation, a plurality of helical flutes (5, 5A) into the outer periphery of a cutter blank from a lead end (6) of the blank distal from the shank
(3) towards the shank (3) , using a peripheral area (16) of a first grinding wheel (15) generally of frusto-conical profile and rotatable about an axis (18) generally transversely of the milling cutter axis (4) , which peripheral area (16) produces, simultaneously, the following three features : -
■a leading face (9) of a trailing tooth (8) ; a rear face (10) on an adjacent preceding tooth (8) ; and a swarf removal gullet (14) , of profile corresponding to that of the peripheral area (16) of the first grinding wheel (15) , having divergent sides defined between the leading face (9) of a trailing tooth (8) and the rear face (10) of an adjacent preceding tooth (8) ;
(ii) grinding, in a second grinding operation, and using a peripheral edge (19, 19A) of a second grinding wheel (20, 20A) of rectangular profile, and rotatable about an axis (18) generally transversely of the milling cutter axis (4) , a relief face (11, 12 or 12A) which extends rearwardly from a leading end of a tooth tip (4) , resulting in a minimum tooth wedge angle (W) of approximately 60° measured between the leading face (9) of a tooth (8) to the relief face (11 and 12 or 12A) of that tooth (8) ; and (iii) grinding, in a third grinding operation, and using a peripheral edge (21) of a third grinding wheel (22) , a radius
(23) on the end of each flute (5, 5A) by grinding along each flute from the lead end (24) of each flute (5, 5A) towards the shank (3) of the cutter (1, IA) .
2. A method as claimed in Claim 1, wherein the relief face produced by the secondary grinding operation, comprises a primary relief rake facet (11) and a secondary relief rake facet (12) , which, extends from an end of the primary relief rake facet (11) distal from the tooth tip (4) .
3. A method as claimed in Claim 2, wherein the primary (11) and secondary (12) facets are planar, the primary relief rake facet (11) being ground at a first angle, and the secondary relief rake (12) facet being ground at a second angle greater than the first .
4. A method as claimed in Claim 1, wherein the relief face (12A) produced by the second grinding operation is of eccentric or convex profile.
5. A milling cutter (1, IA) comprising a shank (3) and a cutting head (2), the cutting head (2) having a plurality of <500 helical flutes (5, 5A), with a lead end of each flute provided with a radius, with each tooth having a minimum tooth wedge angle of approximately 60° measured between a leading face (9) of a tooth (8) and a relief face (11 and 12 or 12A) of that tooth (8) .
6. A milling cutter (1, ■ IA) as claimed in Claim 5, wherein each flute (5, 5A) has a double ratchet tooth form comprising primary relief rake facet (11) and a contiguous secondary relief rake facet (12) . ■
7. A milling cutter (1, IA) as claimed in Claim 6, wherein the primary and secondary facets (11, 12) are planar, the primary relief rake facet (11) being ground at a first angle, and the secondary relief rake facet (12) being ground at a second angle greater than the first.
8. A milling cutter (1, IA) as claimed in Claim 6 " or claim
7, wherein the primary relief rake facet (11) has a clearance angle of approximately 5° to 7°.
9. A milling cutter (1, IA) as claimed in any of Claims 6-
8, wherein the secondary relief rake facet (12) has a clearance angle of approximately 10° to 15°.
10. A milling cutter (1, IA) as claimed in Claim 5, wherein each flute (5, 5A) has a relief face (12a) of eccentric or convex profile.
11. A milling cutter (1, IA) as claimed in. any one of Claims 5 to 10, wherein each tooth (8) has a leading face (9) with a positive radial rake.
12. A milling cutter (1, IA) as claimed in any one of Claims 5 to 11, having <60 flutes (5, 5A) .
13. A milling cutter (1, IA) as claimed in any one of Claims 5 to 12, wherein the wedge angle of each tooth (8) is greater than approximately 60° but less than approximately 90°.
14. A milling cutter (1, IA) as claimed in Claim 13, when appended to Claim 6, wherein the wedge angle of each tooth (8) is 90° less the primary relief rake angle, and less the secondary relief rake angle.
15. A milling cutter (1, IA) as claimed in any one of Claims 5 to 14, wherein the wedge angle of each tooth (8) is approximately 76°.
16. A milling cutter (1, IA) as claimed in any one of Claims 5 to 15, wherein the cutter (1, IA) is of 16mm diameter with 8-20 flutes (5, 5A) with a lmm radius on the lead end of each flute (5, 5A) .
PCT/GB2007/004308 2007-01-23 2007-11-12 Milling cutter manufacturing method WO2008090301A1 (en)

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US12/448,696 US8286536B2 (en) 2007-01-23 2007-11-12 Milling cutter manufacturing method
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2225064A1 (en) * 2007-11-27 2010-09-08 TDY Industries, Inc. Rotary burr comprising cemented carbide
WO2011036439A1 (en) 2009-09-22 2011-03-31 Rolls-Royce Plc Form milling cutter for the machining of titanium alloys etc

Families Citing this family (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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US9878379B2 (en) 2015-04-22 2018-01-30 Kennametal Inc. Cutting tool with enhanced chip evacuation capability and method of making same
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US11897042B2 (en) 2018-08-09 2024-02-13 Kyocera Sgs Precision Tools, Inc. Variable radius gash
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH628832A5 (en) * 1980-08-22 1982-03-31 Willy Voegtli Device for machining cutting tools hard metal or steel.
JPH09136209A (en) * 1995-11-16 1997-05-27 Yutaka Giken Co Ltd End mill
EP1153685A1 (en) * 2000-05-10 2001-11-14 ROLLS-ROYCE plc Multi-fluted milling cutter
WO2006014711A1 (en) * 2004-07-22 2006-02-09 Third Wave Systems High-frequency tooth pass cutting device and method
DE102005002698A1 (en) * 2005-01-19 2006-07-27 Franken GmbH + Co KG Fabrik für Präzisionswerkzeuge Metal-cutting or milling tool has cylindrical blade fixed to base containing at least three separate blades whose cutting edges are at cutting angles to cutting material determined by distance between front and other blades

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2525345B2 (en) * 1983-06-14 1996-08-21 東芝タンガロイ株式会社 End mill
JPH05220669A (en) * 1992-02-07 1993-08-31 O S G Kk Composite grinding wheel
US5281060A (en) * 1992-12-16 1994-01-25 Jancy Engineering Company Annular hole cutter
SE9300875D0 (en) * 1993-03-17 1993-03-17 Sandvik Ab PINNFRAES
JPH0871831A (en) * 1994-09-08 1996-03-19 Mitsubishi Materials Corp End mill
JP2001300813A (en) * 2000-02-18 2001-10-30 Sumitomo Electric Ind Ltd Ball end mill
JP2002126932A (en) * 2000-10-23 2002-05-08 Osg Corp End mill
JP4936495B2 (en) * 2000-10-27 2012-05-23 株式会社不二越 Carbide end mill
US6991409B2 (en) * 2002-12-24 2006-01-31 Niagara Cutter Rotary cutting tool
US20060045639A1 (en) * 2004-09-01 2006-03-02 Berkshire Precision Tool, Llc Multiple-axis cutting toroidal end mill
JP2006263870A (en) 2005-03-24 2006-10-05 Osg Corp Radius end mill and manufacturing method of radius end mill
DE102005043841B4 (en) * 2005-09-13 2009-01-22 Franken GmbH + Co KG Fabrik für Präzisionswerkzeuge Radius cutters, in particular ball or torus cutters, with transverse cutting and / or flattening
US7306408B2 (en) * 2006-01-04 2007-12-11 Sgs Tool Company Rotary cutting tool
US7588396B2 (en) * 2007-03-09 2009-09-15 Berkshire Precision Tool, Llc End mill

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH628832A5 (en) * 1980-08-22 1982-03-31 Willy Voegtli Device for machining cutting tools hard metal or steel.
JPH09136209A (en) * 1995-11-16 1997-05-27 Yutaka Giken Co Ltd End mill
EP1153685A1 (en) * 2000-05-10 2001-11-14 ROLLS-ROYCE plc Multi-fluted milling cutter
WO2006014711A1 (en) * 2004-07-22 2006-02-09 Third Wave Systems High-frequency tooth pass cutting device and method
DE102005002698A1 (en) * 2005-01-19 2006-07-27 Franken GmbH + Co KG Fabrik für Präzisionswerkzeuge Metal-cutting or milling tool has cylindrical blade fixed to base containing at least three separate blades whose cutting edges are at cutting angles to cutting material determined by distance between front and other blades

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HELLE H J: "NEUE TECHNIK ZUM SCHLEIFEN VON GESENKFRASERN", WERKSTATTSTECHNIK, SPRINGER VERLAG. BERLIN, DE, vol. 79, no. 3, 1 March 1989 (1989-03-01), pages 153 - 157, XP000025477, ISSN: 0340-4544 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2225064A1 (en) * 2007-11-27 2010-09-08 TDY Industries, Inc. Rotary burr comprising cemented carbide
WO2011036439A1 (en) 2009-09-22 2011-03-31 Rolls-Royce Plc Form milling cutter for the machining of titanium alloys etc
US8573898B2 (en) 2009-09-22 2013-11-05 Rolls-Royce Plc Form milling cutter for the machining of titanium alloys etc

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GB2446036A (en) 2008-07-30
JP2013255990A (en) 2013-12-26
JP5827647B2 (en) 2015-12-02
IL199638A (en) 2014-04-30
JP5745769B2 (en) 2015-07-08
EP2121243A1 (en) 2009-11-25
GB0701242D0 (en) 2007-02-28
CN101622097A (en) 2010-01-06
GB0721986D0 (en) 2007-12-19
IL199638A0 (en) 2010-04-15
US20090324347A1 (en) 2009-12-31
JP2010516485A (en) 2010-05-20
US8286536B2 (en) 2012-10-16

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