US20200061723A1 - Endmill specification design method, cutting condition detecting method, and processing method - Google Patents

Endmill specification design method, cutting condition detecting method, and processing method Download PDF

Info

Publication number
US20200061723A1
US20200061723A1 US16/609,210 US201716609210A US2020061723A1 US 20200061723 A1 US20200061723 A1 US 20200061723A1 US 201716609210 A US201716609210 A US 201716609210A US 2020061723 A1 US2020061723 A1 US 2020061723A1
Authority
US
United States
Prior art keywords
endmill
case
stable
speed
smax
Prior art date
Legal status (The legal status 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 status listed.)
Abandoned
Application number
US16/609,210
Inventor
Jun Eto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Heavy Industries Ltd
Original Assignee
Mitsubishi Heavy Industries Ltd
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 Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Assigned to MITSUBISHI HEAVY INDUSTRIES, LTD. reassignment MITSUBISHI HEAVY INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ETO, JUN
Publication of US20200061723A1 publication Critical patent/US20200061723A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23CMILLING
    • B23C5/00Milling-cutters
    • B23C5/02Milling-cutters characterised by the shape of the cutter
    • B23C5/10Shank-type cutters, i.e. with an integral shaft
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23CMILLING
    • B23C3/00Milling particular work; Special milling operations; Machines therefor
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23CMILLING
    • B23C2220/00Details of milling processes
    • B23C2220/48Methods of milling not otherwise provided for
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23CMILLING
    • B23C2220/00Details of milling processes
    • B23C2220/64Using an endmill, i.e. a shaft milling cutter, to generate profile of a crankshaft or camshaft
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23CMILLING
    • B23C2250/00Compensating adverse effects during milling
    • B23C2250/16Damping vibrations
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00Programme-control systems
    • G05B19/02Programme-control systems electric
    • G05B19/18Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/4093Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by part programming, e.g. entry of geometrical information as taken from a technical drawing, combining this with machining and material information to obtain control information, named part programme, for the NC machine
    • G05B19/40937Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by part programming, e.g. entry of geometrical information as taken from a technical drawing, combining this with machining and material information to obtain control information, named part programme, for the NC machine concerning programming of machining or material parameters, pocket machining
    • G05B19/40938Tool management
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/30Nc systems
    • G05B2219/35Nc in input of data, input till input file format
    • G05B2219/35044Tool, design of tool, mold, die tooling
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/30Nc systems
    • G05B2219/35Nc in input of data, input till input file format
    • G05B2219/35167Automatic toolpath generation and tool selection
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/30Nc systems
    • G05B2219/35Nc in input of data, input till input file format
    • G05B2219/35185Select optimum tool radius
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P90/00Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
    • Y02P90/02Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Definitions

  • the present invention relates to an endmill specification design method, a cutting condition detecting method, and a processing method.
  • a worker uses a stable pocket serving as a rotation speed region which can avoid the regenerative chatter vibration. In this manner, the worker further reduces a load as much as possible. Therefore, the processing time is extremely lengthened. Moreover, since one surface is processed in multiple paths, a mismatch occurs between the paths. Accordingly, hand finishing is required after the surface is processed.
  • the stable pocket is an integral fraction of natural vibration frequencies. Accordingly, as the rigidity is lowered (as natural vibration is small), rotation speed is lowered, thereby degrading efficiency.
  • PTL 1 discloses a processing method of an endmill focusing on vibration characteristics. That is, PTL 1 discloses a method of using an effect (process damping) in which a tool and a workpiece are damped by coming into contact with each other during processing in a case of low-speed cutting.
  • the natural frequency is raised through weight reduction of the tool so that the process damping in a low-speed region is used in a medium-speed region. Consequently, there is a limitation in further using the process damping in a high-speed region.
  • the present disclosure aims to perform processing by stably using an endmill at a high speed.
  • an endmill specification design method including setting ⁇ 1 and/or N so as to satisfy the following.
  • Smax a maximum spindle speed per one minute of a main spindle having an endmill attached thereto
  • N an outer shape of the endmill
  • Da a natural frequency at which a vibration is maximized in a tool tip of the endmill
  • ⁇ 1 a natural frequency at which a vibration is maximized in a tool tip of the endmill
  • Rd a radial depth of cut of the endmill
  • a stable spindle speed at which the endmill can stably perform machining without generating a regenerative chatter vibration is defined as ⁇ 1 ⁇ 60/N/n (n is a natural number).
  • n is a natural number.
  • the present inventor has found that the rotation speed higher than a first stable spindle speed at which n is defined as 1 also has a wide stable region. Then, this stable region is changed by the radial depth of cut Rd of the endmill. Therefore, ⁇ 1 and/or N are set so as to satisfy the following.
  • the main spindle can be increased to the rotation speed close to the maximum spindle speed Smax, and high speed and stable machining can be performed.
  • the natural frequency ⁇ 1 is decreased by increasing a protrusion amount of the endmill.
  • the first stable spindle speed is decreased by increasing the number of teeth N. In this manner, a stable region having a higher rotation speed than the first stable spindle speed can be widely used.
  • bottom surface machining may be performed in a case of i), and side surface machining may be performed in a case of ii).
  • the radial depth of cut is larger than that in the case of ii). Accordingly, the case of i) is suitable for bottom surface machining in pocket processing, particularly for bottom surface finishing in deep pocket processing. In the case of ii), the radial depth of cut is smaller than that in the case of i). Accordingly, the case of i) is suitable for side surface machining, particularly for single finishing processing in
  • a cutting condition detecting method including setting a rotation speed of a main spindle having an endmill attached thereto so as to satisfy the following.
  • Smax a maximum spindle speed per one minute of the main spindle
  • N the number of teeth of the endmill
  • Da an outer shape of the endmill
  • ⁇ 1 a natural frequency at which a vibration is maximized in a tool tip of the endmill
  • ⁇ 1 a radial depth of cut of the endmill
  • Rd i) in a case where Rd is equal to or greater than 4% of Da, a range of ⁇ 1 ⁇ 60/N ⁇ 6 to Smax is satisfied, and ii) in a case where Rd is smaller than 4% of Da, a range of ⁇ 1 ⁇ 60/N ⁇ 3 to Smax is satisfied.
  • the stable spindle speed at which the endmill can stably perform the machining without generating the regenerative chatter vibration is ⁇ 1 ⁇ 60/N/n (n is a natural number).
  • n is a natural number.
  • the present inventor has found that the rotation speed higher than the first stable spindle speed at which n is defined as 1 also has the wide stable region. Then, this stable region is changed by the radial depth of cut Rd of the endmill.
  • the rotation speed of the main spindle is set so as to satisfy the following.
  • a workpiece can be processed at the rotation speed higher than the first stable spindle speed, and the machining can be stably performed at high speed.
  • bottom surface machining may be performed in a case of i), and side surface machining may be performed in a case of ii).
  • the radial depth of cut is larger than that in the case of ii). Accordingly, the case of i) is suitable for the bottom surface machining in the pocket processing, particularly for the bottom surface finishing in the deep pocket processing. In the case of ii), the radial depth of cut is smaller than that in the case of i). Accordingly, the case of ii) is suitable for the side surface machining, particularly for the single finishing processing in the deep axial cutting of the endmill.
  • the rotation speed of the main spindle is set to a rotation speed so as to avoid ⁇ ′ ⁇ 60/N(m ⁇ 0.5) (m is a natural number), when the natural frequency that is a frequency higher than ⁇ 1 serving as the natural frequency at which the vibration is maximized in the tool tip of the endmill, that has a vibration peak independent of ⁇ 1 , and that has a peak value of the vibration which is equal to or greater than 1/10 of a peak value of ⁇ 1 is defined as ⁇ ′.
  • a median value that may be an unstable region between the adjacent stable spindle speeds of ⁇ ′ can be expressed by ⁇ ′ ⁇ 60/N(m ⁇ 0.5).
  • the rotation speed of the main spindle is set so as to avoid the median value. In this manner, the workpiece can be more stably processed.
  • a processing method including performing machining on a workpiece by using any one of the cutting condition detecting methods.
  • the workpiece can be stably processed at high speed by using the above-described cutting condition detecting method.
  • an axial cutting amount is set to 1 mm or smaller, and a feeding amount per one tooth is set to 0.1 mm/tooth or smaller.
  • the feeding amount per one tooth is set to 0.03 to 0.05 mm/tooth, and the axial cutting amount is set to a length corresponding to the protrusion amount of the endmill. Therefore, a single tool can cope with processing for workpieces having various depths.
  • the above-described cutting amounts or feeding amounts are merely examples, and can be obtained through simulation or processing tests.
  • the workpiece can be stably processed at high speed by using the endmill.
  • FIG. 1 is a schematic configuration diagram illustrating an endmill according to an embodiment of the present invention.
  • FIG. 2 is a graph illustrating a stable pocket.
  • FIG. 3 is a graph illustrating a stable region existing on a rotation speed higher than that of the stable pocket in FIG. 2 .
  • FIG. 4 is a graph illustrating a ratio of each stable spindle speed to a radial depth of cut.
  • FIG. 5 is a graph illustrating vibration response characteristics of a tool tip of the endmill.
  • FIG. 6 is a graph illustrating the stable region for two vibration peaks.
  • an endmill 10 has a shaft 14 extending in an axial direction, and a plurality of teeth 15 disposed in an outer periphery of the shaft 14 .
  • One end of the endmill 10 is attached to a main spindle 5 by using a fixing tool such as a chuck.
  • the main spindle 5 is connected to a rotary shaft of a machine tool (not illustrated), and is rotated at a predetermined rotation speed instructed by a control unit.
  • a maximum spindle speed Smax of the main spindle 5 is determined depending on capacity of the machine tool, and is set to 10,000 to 40,000 (rpm), for example.
  • a length from the main spindle 5 to a tool tip of the endmill 10 is set as an overhang length L.
  • the overhang length L is set to be changed in accordance with processing conditions.
  • the endmill 10 is mainly used in processing aluminum alloy, and is used in performing pocket processing on a member having a thickness of 100 mm to 500 mm, for example.
  • specific processing targets include aircraft structural components (keel beams or main wing center beams).
  • a ratio L/Da of the overhang length L to a tool diameter Da of the endmill 10 is set to 5 or greater.
  • the tool diameter Da of the endmill 10 is set to 16 mm to 25 mm, and the number of teeth N is set to 10 to 25.
  • a stable spindle speed Sn at which the endmill 10 can stably perform the machining without generating a regenerative chatter vibration is determined as the following equation.
  • ⁇ 1 is a natural frequency of the tool tip of the endmill 10
  • N is the number of teeth
  • n is a natural number.
  • the natural frequency ⁇ 1 can be obtained by performing tapping on the endmill 10 attached to the main spindle 5 , and is a frequency indicating a largest vibration peak.
  • the rotation speed region within a predetermined range around the stable spindle speed Sn becomes the stable pocket. If the main spindle 5 is rotated inside the stable pocket, the regenerative chatter vibration can be avoided.
  • FIG. 2 illustrates a plurality of the stable pockets.
  • a horizontal axis represents a main spindle rotation speed [rpm]
  • a vertical axis represents a horizontal cutting amount [mm].
  • the stable region is located below a curve, and an unstable region where the regenerative chatter vibration is generated is located above the curve.
  • Each stable pocket is 1/n th of the first stable pocket SP 1 (refer to Equation (1)).
  • the stable pocket SP illustrated in FIG. 2 there are problems as follows.
  • the overhang length L is long. Accordingly, the natural frequency ⁇ 1 decreases, and the main spindle rotation speed at which the stable pocket SP appears decreases. Therefore, the machining is less likely to be performed at high speed.
  • a rotation speed width of the stable pocket SP is narrowed. Accordingly, the rotation speed is less likely to be adjusted.
  • the stable pocket SP is closer to the natural frequency ⁇ 1 . Accordingly, a forced vibration is likely to be generated.
  • a stable pocket where the regenerative chatter vibration is not generated exists in a region exceeding the first stable pocket SP 1 and further exceeding the natural frequency ⁇ 1 .
  • the horizontal axis represents the main spindle rotation speed [rpm], and the vertical axis represents the horizontal cutting amount [mm].
  • the stable region is located below a curve, and an unstable region where the regenerative chatter vibration is generated is located above the curve.
  • the drawing illustrates a simulation of the endmill 10 where the number of teeth N is defined as 19, the tool diameter Da is defined as 25 mm, and the overhang length L is defined as 170 mm.
  • This simulation is performed using a stability limit analysis of the regenerative chatter vibration in endmill processing, based on the above-described tool geometry and frequency characteristics thereof.
  • a first high-speed stable pocket SP 1 ′ exists in a region of 6,000 [rpm] to 10,000 [rpm] which greatly exceeds the first stable pocket SP 1
  • a large second high-speed stable pocket SP 2 ′ exists in a region of 18,000 [rpm] or higher.
  • the present embodiment adopts the high-speed stable pockets SP 1 ′ and SP 2 ′.
  • the present inventor has found the following. A shape of each stable pocket SPs illustrated in FIG. 3 is changed depending on the natural frequency ⁇ 1 and the radial depth of cut Rd [mm] of the endmill 10 . Therefore, the simulation is performed for various types of the endmill 10 by changing the natural frequency ⁇ 1 and the radial depth of cut Rd. As a result, the present inventor has found that there is a predetermined relationship between the first stable spindle speed S 1 and the first high-speed stable spindle speed S 1 ′ as illustrated in FIG. 4 .
  • the horizontal axis represents Rd/Da [%], which is the percentage of the radial depth of cut Rd to the tool diameter Da of the endmill 10
  • the vertical axis represents a ratio of the first high-speed stable spindle speed S 1 ′ to the first stable spindle speed S 1 .
  • S 1 ′/S 1 is approximately 3 in a case where Rd/Da is smaller than 4%
  • S 1 ′/S 1 is approximately 6 in a case where Rd/Da is equal to or greater than 4%. That is, the meaning is as follows.
  • the first high-speed stable spindle speed S 1 ′ exists around 3 times the first stable spindle speed S 1 . In the case where Rd/Da is equal to or greater than 4%, the first high-speed stable spindle speed S 1 ′ exists around 6 times the first stable spindle speed S 1 . If the first high-speed stable pocket SP 1 ′ including the first high-speed stable spindle speed S 1 ′ is used, the machining can be stably performed at high speed by using the endmill 10 .
  • the above-described natural frequency ⁇ 1 is the frequency which indicates the highest vibration peak in a case where the frequency of the tool tip of the endmill 10 is analyzed.
  • the frequency indicating an independent vibration peak may exist in the frequency higher than the natural frequency ⁇ 1 .
  • the independent vibration peak on the frequency side higher than the natural frequency ⁇ 1 which is the first vibration peak may be recognized as a second peak frequency ⁇ 2 .
  • the stable spindle speed also exists in the second peak frequency ⁇ 2 , and an unstable region exists in a region having no stable spindle speed.
  • FIG. 6 illustrates a result of examining the stable region and the unstable region for the second peak frequency ⁇ 2 .
  • the horizontal axis represents the main spindle rotation speed [rpm]
  • the vertical axis represents the horizontal cutting amount [mm].
  • the drawing illustrates a curve L 1 indicating the stable region corresponding to the natural frequency ⁇ 1 , a curve L 2 indicating the stable region corresponding to the second peak frequency ⁇ 2 , and a curve L 3 obtained by superimposing the curves L 1 and L 2 on each other.
  • a region where L 3 is greatly recessed downward exists around 14000 [rpm] indicated by a line segment L 4 .
  • the reason is the influence caused by the curve L 2 of the second peak frequency ⁇ 2 .
  • the rotation speed region indicated by the line segment L 4 is the unstable region. Accordingly, it is preferable to avoid the rotation speed region. Therefore, the main spindle rotation speed is limited as follows.
  • the natural frequency that is a frequency higher than ⁇ 1 serving as the natural frequency at which the vibration is maximized in the tool tip of the endmill 10 , that has the vibration peak independent of the natural frequency ⁇ 1 , and that has the peak value of the vibration which is equal to or greater than 1/10 of the peak value of ⁇ 1 is defined as ⁇ ′. It is assumed that the m-number of ⁇ ′ exists (m is a natural number). In this case, the rotation speed of the main spindle 5 is set so as to be the rotation speed avoiding ⁇ ′ ⁇ 60/N/(m ⁇ 0.5). In this manner, it is possible to avoid the center rotation speed between the adjacent stable pockets.
  • Smax represents the maximum spindle speed of the main spindle 5 .
  • ⁇ 1 and/or N are set so as to satisfy ( ⁇ 1 ⁇ 60/N ⁇ 6 ⁇ Smax, i) in a case where the radial depth of cut Rd is equal to or greater than 4% of the tool diameter Da, and so as to satisfy ⁇ 1 ⁇ 60/N ⁇ 3 ⁇ Smax, ii) in a case where the radial depth of cut Rd is smaller than 4% of the tool diameter Da.
  • the rotation speed can be increased up to the main spindle rotation speed close to the maximum spindle speed Smax of the main spindle 5 . Accordingly, the machining can be stably performed at high speed.
  • the natural frequency ⁇ 1 is decreased by increasing the protrusion amount of the endmill.
  • the first stable spindle speed S 1 is decreased by increasing the number of teeth N. In this manner, the first high-speed stable pocket SP 1 ′ having the higher rotation speed than the first stable spindle speed S 1 can be widely used.
  • bottom surface machining is preferably performed in the above-described case of i), and side surface machining is preferably performed in the above-described case of ii).
  • the radial depth of cut Rd is larger than that in the case of ii). Accordingly, the case of i) is suitable for the bottom surface machining in the pocket processing, particularly for the bottom surface finishing in the deep pocket processing. In the case of ii), the radial depth of cut Rd is smaller than that in the case of i). Accordingly, the case of ii) is suitable for the side surface machining, particularly for the single finishing processing in the deep axial cutting of the endmill.
  • Smax represents the maximum spindle speed of the main spindle 5 .
  • the rotation speed of the main spindle 5 is set so as to satisfy a range of ⁇ 1 ⁇ 60/N ⁇ 6 to Smax, i) in a case where the radial depth of cut Rd is equal to or greater than 4% of the tool diameter Da, and so as to satisfy a range of ⁇ 1 ⁇ 60/N ⁇ 3 to Smax, ii) in a case where the radial depth of cut Rd is smaller than 4% of the tool diameter Da.
  • the processing conditions are set to the above-described conditions. In this manner, a workpiece can be processed in the first high-speed stable pocket SP 1 ′ having the higher rotation speed than the first stable spindle speed S 1 . Therefore, the machining can be stably performed at high speed.
  • bottom surface machining is preferably performed in the above-described case of i), and side surface machining is preferably performed in the above-described case of ii).
  • the radial depth of cut Rd is larger than that in the case of ii). Accordingly, the case of i) is suitable for the bottom surface machining in the pocket processing, particularly for the bottom surface finishing in the deep pocket processing. In the case of ii), the radial depth of cut Rd is smaller than that in the case of i). Accordingly, the case of ii) is suitable for the side surface machining, particularly for the single finishing processing in the deep axial cutting of the endmill.
  • the rotation speed of the main spindle 5 is set so as to avoid ⁇ + ⁇ 60/N(m ⁇ 0.5) (m is a natural number), when the natural frequency that is the frequency higher than the natural frequency ⁇ 1 at which the vibration is maximized in the tool tip of the endmill 10 , that has the vibration peak independent of ⁇ 1 , and that has the peak value of the vibration which is equal to or greater than 1/10 of the peak value of ⁇ 1 is defined as ⁇ ′.
  • the stable spindle speed of ⁇ ′ may appear at the frequency higher than ⁇ 1 in some cases.
  • the rotation speed of the main spindle 5 is set so as to avoid the median value. In this manner, the processing can be more stably performed.
  • the processing method the machining is performed using the endmill 10 under the conditions of the above-described cutting condition detecting method.
  • the endmill 10 obtained based on the above-described endmill specification design method is used. In this manner, the processing can be stably performed at high speed.
  • the axial cutting amount is set to 1 mm or smaller, and the feeding amount per one tooth is set to 0.1 mm/tooth or smaller.
  • the feeding amount per one tooth is set to 0.03 to 0.05 mm/tooth, and the axial cutting amount is set to the length corresponding to the protrusion amount of the endmill. Therefore, a single tool can cope with processing for workpieces having various depths.
  • the above-described cutting amounts or feeding amounts are merely examples, and can be obtained through simulation or processing tests.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Milling Processes (AREA)
  • Automatic Control Of Machine Tools (AREA)
  • Numerical Control (AREA)

Abstract

Provided is an endmill (5). The maximum spindle speed, per one minute, of a main spindle to which the endmill is attached is Smax. The number of teeth of the endmill (5) is N. The outer shape of the endmill (5) is Da. The natural frequency at which vibrations at the end of the endmill (5) reach a maximum level is ω1. ω1 and/or N are set so that when the diameter-direction infeed amount of the endmill (5) is set to Rd: i) ω1×60/N×6<Smax, if Rd is at least 4% of Da; and ii) ω1×60/N×3<Smax, if Rd is less than 4% of Da.

Description

    TECHNICAL FIELD
  • The present invention relates to an endmill specification design method, a cutting condition detecting method, and a processing method.
  • BACKGROUND ART
  • In recent years, aircraft structural components are progressively integrated with each other, and component shapes thereof are more complicated. A product height increases. Consequently, there is an increasing need for shape processing using a protruding long tool protruding beyond L/D (overhang length/diameter)=5. These components become joint parts as primary structural members in many cases. Accordingly, processed surface characteristics of the components are important. However, the protruding long tool has a problem of a regenerative chatter vibration generated on the tool side, thereby causing a problem in that a processed surface may be defective and a processing time may be lengthened. In general, rigidity is proportional to the cube of a protrusion amount. Accordingly, when the components are processed using the long tool, a worker uses a stable pocket serving as a rotation speed region which can avoid the regenerative chatter vibration. In this manner, the worker further reduces a load as much as possible. Therefore, the processing time is extremely lengthened. Moreover, since one surface is processed in multiple paths, a mismatch occurs between the paths. Accordingly, hand finishing is required after the surface is processed. In addition, the stable pocket is an integral fraction of natural vibration frequencies. Accordingly, as the rigidity is lowered (as natural vibration is small), rotation speed is lowered, thereby degrading efficiency.
  • In order to cope with this problem, the following processing method called single finishing has been recently promoted. In a case of side surface finishing, a side surface is finished in one step. However, this processing also has the following problems.
      • Large vibration is generated due to large axial cutting.
      • A stable region is narrowed and becomes unstable since a tool having a long overhang length has low damping performance.
      • Since the rigidity is weak, the tool is fallen down as much as 0.1 mm or longer. Accordingly, quick feeding is not available.
  • In addition, in a case of bottom surface finishing for a deep pocket, processing is performed using a whole diameter of the tool. Accordingly, the chatter vibration is likely to be generated. Therefore, cutting is generally performed by reducing radial cutting or feeding.
  • In view of these circumstances, as a tool which is less likely to vibrate, there are provided some inventions and products relating to a tooth shape. However, tool manufacturers in the related art have insufficient viewpoints of vibration characteristics. Therefore, dedicated tools have narrow application conditions. The single finishing is very unstable, and a user has difficulties in using the single finishing.
  • PTL 1 discloses a processing method of an endmill focusing on vibration characteristics. That is, PTL 1 discloses a method of using an effect (process damping) in which a tool and a workpiece are damped by coming into contact with each other during processing in a case of low-speed cutting.
  • CITATION LIST Patent Literature
  • [PTL 1] Specification of U.S. Pat. No. 8,875,367
  • SUMMARY OF INVENTION Technical Problem
  • However, according to PTL 1, the natural frequency is raised through weight reduction of the tool so that the process damping in a low-speed region is used in a medium-speed region. Consequently, there is a limitation in further using the process damping in a high-speed region.
  • In view of these problems, the present disclosure aims to perform processing by stably using an endmill at a high speed.
  • Solution to Problem
  • According to an aspect of the present invention, there is provided an endmill specification design method including setting ω1 and/or N so as to satisfy the following. When a maximum spindle speed per one minute of a main spindle having an endmill attached thereto is defined as Smax, the number of teeth of the endmill is defined as N, an outer shape of the endmill is defined as Da, a natural frequency at which a vibration is maximized in a tool tip of the endmill is defined as ω1, and a radial depth of cut of the endmill is defined as Rd, i) in a case where Rd is equal to or greater than 4% of Da, ω1×60/N×6<Smax is satisfied, and ii) in a case where Rd is smaller than 4% of Da, ω1×60/N×3<Smax is satisfied.
  • A stable spindle speed at which the endmill can stably perform machining without generating a regenerative chatter vibration is defined as ω1×60/N/n (n is a natural number). Through examinations, the present inventor has found that the rotation speed higher than a first stable spindle speed at which n is defined as 1 also has a wide stable region. Then, this stable region is changed by the radial depth of cut Rd of the endmill. Therefore, ω1 and/or N are set so as to satisfy the following.
  • i) In a case where Rd is equal to or greater than 4% of Da, ω1×60/N×6<Smax is satisfied.
  • ii) In a case where Rd is smaller than 4% of Da, ω1×60/N×2<Smax is satisfied.
  • In this manner, the main spindle can be increased to the rotation speed close to the maximum spindle speed Smax, and high speed and stable machining can be performed. For example, the natural frequency ω1 is decreased by increasing a protrusion amount of the endmill. The first stable spindle speed is decreased by increasing the number of teeth N. In this manner, a stable region having a higher rotation speed than the first stable spindle speed can be widely used.
  • In the endmill specification design method according to the aspect of the present invention, bottom surface machining may be performed in a case of i), and side surface machining may be performed in a case of ii).
  • In the case of i), the radial depth of cut is larger than that in the case of ii). Accordingly, the case of i) is suitable for bottom surface machining in pocket processing, particularly for bottom surface finishing in deep pocket processing. In the case of ii), the radial depth of cut is smaller than that in the case of i). Accordingly, the case of i) is suitable for side surface machining, particularly for single finishing processing in
  • According to another aspect of the present invention, there is provided a cutting condition detecting method including setting a rotation speed of a main spindle having an endmill attached thereto so as to satisfy the following. When a maximum spindle speed per one minute of the main spindle is defined as Smax, the number of teeth of the endmill is defined as N, an outer shape of the endmill is defined as Da, a natural frequency at which a vibration is maximized in a tool tip of the endmill is defined as ω1, and a radial depth of cut of the endmill is defined as Rd, i) in a case where Rd is equal to or greater than 4% of Da, a range of ω1×60/N×6 to Smax is satisfied, and ii) in a case where Rd is smaller than 4% of Da, a range of ω1×60/N×3 to Smax is satisfied.
  • The stable spindle speed at which the endmill can stably perform the machining without generating the regenerative chatter vibration is ω1×60/N/n (n is a natural number). Through examinations, the present inventor has found that the rotation speed higher than the first stable spindle speed at which n is defined as 1 also has the wide stable region. Then, this stable region is changed by the radial depth of cut Rd of the endmill.
  • Therefore, the rotation speed of the main spindle is set so as to satisfy the following.
  • i) In a case where Rd is equal to or greater than 4% of Da, a range of ω1×60/N×6 to Smax is satisfied.
  • ii) In a case where Rd is smaller than 4% of Da, a range of ω1×60/N×3 to Smax is satisfied.
  • In this manner, a workpiece can be processed at the rotation speed higher than the first stable spindle speed, and the machining can be stably performed at high speed.
  • In the cutting condition detecting method according to the aspect of the present invention, bottom surface machining may be performed in a case of i), and side surface machining may be performed in a case of ii).
  • In the case of i), the radial depth of cut is larger than that in the case of ii). Accordingly, the case of i) is suitable for the bottom surface machining in the pocket processing, particularly for the bottom surface finishing in the deep pocket processing. In the case of ii), the radial depth of cut is smaller than that in the case of i). Accordingly, the case of ii) is suitable for the side surface machining, particularly for the single finishing processing in the deep axial cutting of the endmill.
  • In the cutting condition detecting method according to the aspect of the present invention, the rotation speed of the main spindle is set to a rotation speed so as to avoid ω′×60/N(m−0.5) (m is a natural number), when the natural frequency that is a frequency higher than ω1 serving as the natural frequency at which the vibration is maximized in the tool tip of the endmill, that has a vibration peak independent of ω1, and that has a peak value of the vibration which is equal to or greater than 1/10 of a peak value of ω1 is defined as ω′.
  • When the natural frequency that is a frequency higher than ω1 serving as the natural frequency at which the vibration is maximized in the tool tip of the endmill, that has a vibration peak independent of ω1, and that has a peak value of the vibration which is equal to or greater than 1/10 of a peak value of ω1 is defined as ω′, the stable spindle speed is also set as ω′×60/N/n for ω′ (n is a natural number). Since ω′ has the frequency higher than ω1, the stable spindle speed of ω′ may appear at the frequency higher than ω1 in some cases. On the other hand, the regenerative chatter vibration appears between the adjacent stable spindle speeds (for example, between m=1 and 2). Therefore, a median value that may be an unstable region between the adjacent stable spindle speeds of ω′ can be expressed by ω′×60/N(m−0.5). The rotation speed of the main spindle is set so as to avoid the median value. In this manner, the workpiece can be more stably processed.
  • According to still another aspect of the present invention, there is provided a processing method including performing machining on a workpiece by using any one of the cutting condition detecting methods.
  • The workpiece can be stably processed at high speed by using the above-described cutting condition detecting method. For example, in a case of the bottom surface finishing, an axial cutting amount is set to 1 mm or smaller, and a feeding amount per one tooth is set to 0.1 mm/tooth or smaller. In a case of the side surface finishing, the feeding amount per one tooth is set to 0.03 to 0.05 mm/tooth, and the axial cutting amount is set to a length corresponding to the protrusion amount of the endmill. Therefore, a single tool can cope with processing for workpieces having various depths. The above-described cutting amounts or feeding amounts are merely examples, and can be obtained through simulation or processing tests.
  • Advantageous Effects of Invention
  • The workpiece can be stably processed at high speed by using the endmill.
  • BRIEF DESCRIPTION OF DRAWINGS
  • FIG. 1 is a schematic configuration diagram illustrating an endmill according to an embodiment of the present invention.
  • FIG. 2 is a graph illustrating a stable pocket.
  • FIG. 3 is a graph illustrating a stable region existing on a rotation speed higher than that of the stable pocket in FIG. 2.
  • FIG. 4 is a graph illustrating a ratio of each stable spindle speed to a radial depth of cut.
  • FIG. 5 is a graph illustrating vibration response characteristics of a tool tip of the endmill.
  • FIG. 6 is a graph illustrating the stable region for two vibration peaks.
  • DESCRIPTION OF EMBODIMENTS
  • As illustrated in FIG. 1, an endmill 10 has a shaft 14 extending in an axial direction, and a plurality of teeth 15 disposed in an outer periphery of the shaft 14. One end of the endmill 10 is attached to a main spindle 5 by using a fixing tool such as a chuck. The main spindle 5 is connected to a rotary shaft of a machine tool (not illustrated), and is rotated at a predetermined rotation speed instructed by a control unit. A maximum spindle speed Smax of the main spindle 5 is determined depending on capacity of the machine tool, and is set to 10,000 to 40,000 (rpm), for example.
  • A length from the main spindle 5 to a tool tip of the endmill 10 is set as an overhang length L. The overhang length L is set to be changed in accordance with processing conditions. The endmill 10 is mainly used in processing aluminum alloy, and is used in performing pocket processing on a member having a thickness of 100 mm to 500 mm, for example. For example, specific processing targets include aircraft structural components (keel beams or main wing center beams). A ratio L/Da of the overhang length L to a tool diameter Da of the endmill 10 is set to 5 or greater.
  • The tool diameter Da of the endmill 10 is set to 16 mm to 25 mm, and the number of teeth N is set to 10 to 25.
  • In machining performed by the endmill 10, a stable spindle speed Sn at which the endmill 10 can stably perform the machining without generating a regenerative chatter vibration is determined as the following equation.

  • Sn=ω1×60/N/n [rpm]  (1)
  • ω1 is a natural frequency of the tool tip of the endmill 10, N is the number of teeth, and n is a natural number. For example, the natural frequency ω1 can be obtained by performing tapping on the endmill 10 attached to the main spindle 5, and is a frequency indicating a largest vibration peak.
  • The rotation speed region within a predetermined range around the stable spindle speed Sn becomes the stable pocket. If the main spindle 5 is rotated inside the stable pocket, the regenerative chatter vibration can be avoided.
  • FIG. 2 illustrates a plurality of the stable pockets. In the drawing, a horizontal axis represents a main spindle rotation speed [rpm], and a vertical axis represents a horizontal cutting amount [mm]. The stable region is located below a curve, and an unstable region where the regenerative chatter vibration is generated is located above the curve.
  • The drawing illustrates a first stable pocket SP1 at a first stable spindle speed S1 defined as n=1 in Equation (1) above, a second stable pocket SP2 at a second stable spindle speed S2 defined as n=2, and a third stable pocket SP3 at a third stable spindle speed S3 defined as n=3. Each stable pocket is 1/nth of the first stable pocket SP1 (refer to Equation (1)).
  • In a case of using the stable pocket SP illustrated in FIG. 2, there are problems as follows. In the endmill 10 where L/Da is 5 or greater, the overhang length L is long. Accordingly, the natural frequency ω1 decreases, and the main spindle rotation speed at which the stable pocket SP appears decreases. Therefore, the machining is less likely to be performed at high speed. In addition, a rotation speed width of the stable pocket SP is narrowed. Accordingly, the rotation speed is less likely to be adjusted. In addition, as the natural frequency ω1 decreases, the stable pocket SP is closer to the natural frequency ω1. Accordingly, a forced vibration is likely to be generated.
  • In contrast, the present inventor has found the following. As illustrated in FIG. 3, a stable pocket where the regenerative chatter vibration is not generated exists in a region exceeding the first stable pocket SP1 and further exceeding the natural frequency ω1. The horizontal axis represents the main spindle rotation speed [rpm], and the vertical axis represents the horizontal cutting amount [mm]. The stable region is located below a curve, and an unstable region where the regenerative chatter vibration is generated is located above the curve.
  • The drawing illustrates a simulation of the endmill 10 where the number of teeth N is defined as 19, the tool diameter Da is defined as 25 mm, and the overhang length L is defined as 170 mm. This simulation is performed using a stability limit analysis of the regenerative chatter vibration in endmill processing, based on the above-described tool geometry and frequency characteristics thereof.
  • As can be understood from the drawing, a first high-speed stable pocket SP1′ exists in a region of 6,000 [rpm] to 10,000 [rpm] which greatly exceeds the first stable pocket SP1, and a large second high-speed stable pocket SP2′ exists in a region of 18,000 [rpm] or higher. The present embodiment adopts the high-speed stable pockets SP1′ and SP2′.
  • Furthermore, the present inventor has found the following. A shape of each stable pocket SPs illustrated in FIG. 3 is changed depending on the natural frequency ω1 and the radial depth of cut Rd [mm] of the endmill 10. Therefore, the simulation is performed for various types of the endmill 10 by changing the natural frequency ω1 and the radial depth of cut Rd. As a result, the present inventor has found that there is a predetermined relationship between the first stable spindle speed S1 and the first high-speed stable spindle speed S1′ as illustrated in FIG. 4.
  • In FIG. 4, the horizontal axis represents Rd/Da [%], which is the percentage of the radial depth of cut Rd to the tool diameter Da of the endmill 10, and the vertical axis represents a ratio of the first high-speed stable spindle speed S1′ to the first stable spindle speed S1. As can be understood from the drawing, S1′/S1 is approximately 3 in a case where Rd/Da is smaller than 4%, and S1′/S1 is approximately 6 in a case where Rd/Da is equal to or greater than 4%. That is, the meaning is as follows. In the case where Rd/Da is smaller than 4%, the first high-speed stable spindle speed S1′ exists around 3 times the first stable spindle speed S1. In the case where Rd/Da is equal to or greater than 4%, the first high-speed stable spindle speed S1′ exists around 6 times the first stable spindle speed S1. If the first high-speed stable pocket SP1′ including the first high-speed stable spindle speed S1′ is used, the machining can be stably performed at high speed by using the endmill 10.
  • Next, referring to FIGS. 5 and 6, influence on a vibration peak of the endmill 10 at the frequency higher than the natural frequency ω1 will be examined. The above-described natural frequency ω1 is the frequency which indicates the highest vibration peak in a case where the frequency of the tool tip of the endmill 10 is analyzed. In some cases, the frequency indicating an independent vibration peak may exist in the frequency higher than the natural frequency ω1. Specifically, as illustrated in FIG. 5, in some cases, the independent vibration peak on the frequency side higher than the natural frequency ω1 which is the first vibration peak may be recognized as a second peak frequency ω2. As expressed in Equation (1), the stable spindle speed also exists in the second peak frequency ω2, and an unstable region exists in a region having no stable spindle speed. FIG. 6 illustrates a result of examining the stable region and the unstable region for the second peak frequency ω2.
  • In FIG. 6, the horizontal axis represents the main spindle rotation speed [rpm], and the vertical axis represents the horizontal cutting amount [mm]. The drawing illustrates a curve L1 indicating the stable region corresponding to the natural frequency ω1, a curve L2 indicating the stable region corresponding to the second peak frequency ω2, and a curve L3 obtained by superimposing the curves L1 and L2 on each other. As can be understood from the drawing, a region where L3 is greatly recessed downward exists around 14000 [rpm] indicated by a line segment L4. The reason is the influence caused by the curve L2 of the second peak frequency ω2. The rotation speed region indicated by the line segment L4 is the unstable region. Accordingly, it is preferable to avoid the rotation speed region. Therefore, the main spindle rotation speed is limited as follows.
  • The natural frequency that is a frequency higher than ω1 serving as the natural frequency at which the vibration is maximized in the tool tip of the endmill 10, that has the vibration peak independent of the natural frequency ω1, and that has the peak value of the vibration which is equal to or greater than 1/10 of the peak value of ω1 is defined as ω′. It is assumed that the m-number of ω′ exists (m is a natural number). In this case, the rotation speed of the main spindle 5 is set so as to be the rotation speed avoiding ω′×60/N/(m−0.5). In this manner, it is possible to avoid the center rotation speed between the adjacent stable pockets.
  • Endmill Specification Design Method
  • Next, an endmill specification design method used based on the above-described concept will be described. Smax represents the maximum spindle speed of the main spindle 5. ω1 and/or N are set so as to satisfy (ω1×60/N×6<Smax, i) in a case where the radial depth of cut Rd is equal to or greater than 4% of the tool diameter Da, and so as to satisfy ω1×60/N×3<Smax, ii) in a case where the radial depth of cut Rd is smaller than 4% of the tool diameter Da.
  • In this manner, the rotation speed can be increased up to the main spindle rotation speed close to the maximum spindle speed Smax of the main spindle 5. Accordingly, the machining can be stably performed at high speed. For example, the natural frequency ω1 is decreased by increasing the protrusion amount of the endmill. The first stable spindle speed S1 is decreased by increasing the number of teeth N. In this manner, the first high-speed stable pocket SP1′ having the higher rotation speed than the first stable spindle speed S1 can be widely used.
  • In this case, bottom surface machining is preferably performed in the above-described case of i), and side surface machining is preferably performed in the above-described case of ii).
  • In the case of i), the radial depth of cut Rd is larger than that in the case of ii). Accordingly, the case of i) is suitable for the bottom surface machining in the pocket processing, particularly for the bottom surface finishing in the deep pocket processing. In the case of ii), the radial depth of cut Rd is smaller than that in the case of i). Accordingly, the case of ii) is suitable for the side surface machining, particularly for the single finishing processing in the deep axial cutting of the endmill.
  • Cutting Condition Detecting Method
  • Next, a cutting condition detecting method used based on the above-described concept will be described. Smax represents the maximum spindle speed of the main spindle 5. The rotation speed of the main spindle 5 is set so as to satisfy a range of ω1×60/N×6 to Smax, i) in a case where the radial depth of cut Rd is equal to or greater than 4% of the tool diameter Da, and so as to satisfy a range of ω1×60/N×3 to Smax, ii) in a case where the radial depth of cut Rd is smaller than 4% of the tool diameter Da.
  • The processing conditions are set to the above-described conditions. In this manner, a workpiece can be processed in the first high-speed stable pocket SP1′ having the higher rotation speed than the first stable spindle speed S1. Therefore, the machining can be stably performed at high speed.
  • In this case, bottom surface machining is preferably performed in the above-described case of i), and side surface machining is preferably performed in the above-described case of ii).
  • In the case of i), the radial depth of cut Rd is larger than that in the case of ii). Accordingly, the case of i) is suitable for the bottom surface machining in the pocket processing, particularly for the bottom surface finishing in the deep pocket processing. In the case of ii), the radial depth of cut Rd is smaller than that in the case of i). Accordingly, the case of ii) is suitable for the side surface machining, particularly for the single finishing processing in the deep axial cutting of the endmill.
  • Furthermore, it is preferable to add the following conditions when the processing conditions are set. The rotation speed of the main spindle 5 is set so as to avoid ω+×60/N(m−0.5) (m is a natural number), when the natural frequency that is the frequency higher than the natural frequency ω1 at which the vibration is maximized in the tool tip of the endmill 10, that has the vibration peak independent of ω1, and that has the peak value of the vibration which is equal to or greater than 1/10 of the peak value of ω1 is defined as ω′.
  • Since ω′ has the frequency higher than ω1, the stable spindle speed of ω′ may appear at the frequency higher than ω1 in some cases. On the other hand, the regenerative chatter vibration appears between the adjacent stable spindle speeds (for example, between m=1 and 2) (refer to FIG. 6). Therefore, a median value that may be an unstable region between the adjacent stable spindle speeds of ω′ can be expressed by ω+60/N(m−0.5). The rotation speed of the main spindle 5 is set so as to avoid the median value. In this manner, the processing can be more stably performed.
  • Processing Method
  • Next, a processing method used based on the above-described concept will be described. As the processing method, the machining is performed using the endmill 10 under the conditions of the above-described cutting condition detecting method. In this case, the endmill 10 obtained based on the above-described endmill specification design method is used. In this manner, the processing can be stably performed at high speed.
  • For example, in a case of the bottom surface finishing, the axial cutting amount is set to 1 mm or smaller, and the feeding amount per one tooth is set to 0.1 mm/tooth or smaller. In a case of the side surface finishing, the feeding amount per one tooth is set to 0.03 to 0.05 mm/tooth, and the axial cutting amount is set to the length corresponding to the protrusion amount of the endmill. Therefore, a single tool can cope with processing for workpieces having various depths. The above-described cutting amounts or feeding amounts are merely examples, and can be obtained through simulation or processing tests.
  • REFERENCE SIGNS LIST
    • 5: main spindle
    • 10: endmill
    • 14: shaft
    • 15: tooth
    • Da: tool diameter (of endmill)
    • L: overhang length (of endmill)
    • Smax: maximum spindle speed (of main spindle)
    • Rd: radial depth of cut
    • ω1: natural frequency (of endmill tool tip)
    • S1: first stable spindle speed
    • S1′: first high-speed stable spindle speed
    • SP, SP1, SP2, SP3: stable pocket
    • SP1′: first high-speed stable pocket
    • SP2′: second high-speed stable pocket

Claims (6)

1. An endmill specification design method, comprising:
setting ω1 and/or N so as to satisfy the following,
wherein when a maximum spindle speed per one minute of a main spindle having an endmill attached thereto is defined as Smax,
the number of teeth of the endmill is defined as N,
an outer shape of the endmill is defined as Da,
a natural frequency at which a vibration is maximized in a tool tip of the endmill is defined as ω1, and
a radial depth of cut of the endmill is defined as Rd,
i) in a case where Rd is equal to or greater than 4% of Da,
ω1×60/N×6<Smax is satisfied, and
ii) in a case where Rd is smaller than 4% of Da,
ω1×60/N×3<Smax is satisfied.
2. The endmill specification design method according to claim 1,
wherein bottom surface machining is performed in a case of i), and side surface machining is performed in a case of ii).
3. A cutting condition detecting method, comprising:
setting a rotation speed of a main spindle having an endmill attached thereto so as to satisfy the following,
wherein when a maximum spindle speed per one minute of the main spindle is defined as Smax,
the number of teeth of the endmill is defined as N,
an outer shape of the endmill is defined as Da,
a natural frequency at which a vibration is maximized in a tool tip of the endmill is defined as ω1, and
a radial depth of cut of the endmill is defined as Rd,
i) in a case where Rd is equal to or greater than 4% of Da,
a range of ω1×60/N×6 to Smax is satisfied, and
ii) in a case where Rd is smaller than 4% of Da,
a range of ω1×60/N×3 to Smax is satisfied.
4. The cutting condition detecting method according to claim 3,
wherein bottom surface machining is performed in a case of i), and side surface machining is performed in a case of ii).
5. The cutting condition detecting method according to claim 3,
wherein the rotation speed of the main spindle is set to a rotation speed so as to avoid ω′×60/N(m−0.5) (m is a natural number), when the natural frequency that is a frequency higher than oil serving as the natural frequency at which the vibration is maximized in the tool tip of the endmill, that has a vibration peak independent of ω1, and that has a peak value of the vibration which is equal to or greater than 1/10 of a peak value of ω1 is defined as ω′.
6. A processing method comprising:
performing machining on a workpiece by using the cutting condition detecting method according to claim 3.
US16/609,210 2017-10-25 2017-10-25 Endmill specification design method, cutting condition detecting method, and processing method Abandoned US20200061723A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2017/038581 WO2019082317A1 (en) 2017-10-25 2017-10-25 End mill specification setting method, processing condition setting method, and processing method

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2017/038581 A-371-Of-International WO2019082317A1 (en) 2017-10-25 2017-10-25 End mill specification setting method, processing condition setting method, and processing method

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/883,958 Division US20220379389A1 (en) 2017-10-25 2022-08-09 Endmill specification design method, cutting condition detecting method, and processing method

Publications (1)

Publication Number Publication Date
US20200061723A1 true US20200061723A1 (en) 2020-02-27

Family

ID=66247250

Family Applications (2)

Application Number Title Priority Date Filing Date
US16/609,210 Abandoned US20200061723A1 (en) 2017-10-25 2017-10-25 Endmill specification design method, cutting condition detecting method, and processing method
US17/883,958 Pending US20220379389A1 (en) 2017-10-25 2022-08-09 Endmill specification design method, cutting condition detecting method, and processing method

Family Applications After (1)

Application Number Title Priority Date Filing Date
US17/883,958 Pending US20220379389A1 (en) 2017-10-25 2022-08-09 Endmill specification design method, cutting condition detecting method, and processing method

Country Status (4)

Country Link
US (2) US20200061723A1 (en)
EP (1) EP3603863A4 (en)
JP (1) JP6953545B2 (en)
WO (1) WO2019082317A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210379719A1 (en) * 2019-02-27 2021-12-09 Mitsubishi Heavy Industries, Ltd. End mill inspection device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7315178B2 (en) * 2021-09-30 2023-07-26 三菱重工業株式会社 End mill specification setting method, machining condition setting method, and machining method using the same

Family Cites Families (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4277988A (en) * 1979-02-12 1981-07-14 Union Carbide Corporation Method of manufacturing a contoured stamping die
US6085121A (en) * 1997-09-22 2000-07-04 Design & Manufacturing Solutions, Inc. Device and method for recommending dynamically preferred speeds for machining
US6077002A (en) * 1998-10-05 2000-06-20 General Electric Company Step milling process
US6352496B1 (en) * 2000-01-28 2002-03-05 Imta Manufacturing Technology & Automation Company High-speed milling machine with rotary table
JP4177028B2 (en) * 2002-05-22 2008-11-05 株式会社神戸製鋼所 Machining method by small diameter end mill and method for determining machining conditions
JP4622873B2 (en) * 2006-01-27 2011-02-02 株式会社日立プラントテクノロジー NC program creation method and program
JP4835442B2 (en) * 2007-01-11 2011-12-14 株式会社日立製作所 Calculation method of cutting end coordinates in shoulder cutting using a rotary tool
JP4433422B2 (en) * 2007-05-24 2010-03-17 オークマ株式会社 Vibration suppression device
US8296919B2 (en) 2007-06-04 2012-10-30 The Boeing Company Increased process damping via mass reduction for high performance milling
US8529173B2 (en) * 2008-01-22 2013-09-10 Valenite, Llc Method to align characteristic frequency of material removal tool and rotation speed of spindle of machine tool and material removal tool so aligned
JP5300970B2 (en) * 2009-03-13 2013-09-25 株式会社牧野フライス製作所 Spindle rotation control method and machine tool control device
JP2010269437A (en) * 2009-05-25 2010-12-02 Hitachi Tool Engineering Ltd Cemented carbide end mill
SE534832C2 (en) * 2010-05-10 2012-01-17 Sandvik Intellectual Property Indexable cutter for milling tools
JP5619640B2 (en) * 2011-01-28 2014-11-05 Dmg森精機株式会社 Machine tool, machining method, program, and NC data generator
JP5917251B2 (en) * 2012-04-12 2016-05-11 Okk株式会社 Chatter vibration suppression system and suppression method
JP5288318B1 (en) * 2012-10-23 2013-09-11 エヌティーエンジニアリング株式会社 Chatter control method for work machines
JP2014140918A (en) * 2013-01-23 2014-08-07 Hitachi Ltd Cutting vibration inhibition method, arithmetic control device, and machine tool
KR102092968B1 (en) * 2013-06-10 2020-03-24 두산공작기계 주식회사 setting method of cut depth of initial axial direction for spin cutting tool and the same control device
US9731360B2 (en) * 2013-07-01 2017-08-15 National University Corporation Nagoya University End milling apparatus, CAM apparatus, and NC program
JP6625794B2 (en) * 2014-05-21 2019-12-25 Dmg森精機株式会社 A method for calculating a spindle stable rotational speed capable of suppressing chatter vibration, a method for notifying the method, a method for controlling a spindle rotational speed, an NC program editing method, and an apparatus therefor.
JP6302794B2 (en) * 2014-08-21 2018-03-28 オークマ株式会社 Rotation speed display method
JP6414819B2 (en) * 2015-02-26 2018-10-31 ブラザー工業株式会社 Workpiece machining method and workpiece machining system
JP2017154202A (en) * 2016-03-01 2017-09-07 三菱電機株式会社 Processing method and processing device by end mill
WO2017154671A1 (en) * 2016-03-11 2017-09-14 国立大学法人名古屋大学 End mill machining device, cam device, nc program, and machining method
JP6879668B2 (en) * 2016-03-15 2021-06-02 国立大学法人 名古屋工業大学 Cutting method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210379719A1 (en) * 2019-02-27 2021-12-09 Mitsubishi Heavy Industries, Ltd. End mill inspection device
US11701746B2 (en) * 2019-02-27 2023-07-18 Mitsubishi Heavy Industries, Ltd. End mill inspection device

Also Published As

Publication number Publication date
EP3603863A4 (en) 2020-07-15
JPWO2019082317A1 (en) 2020-02-27
US20220379389A1 (en) 2022-12-01
JP6953545B2 (en) 2021-10-27
WO2019082317A1 (en) 2019-05-02
EP3603863A1 (en) 2020-02-05

Similar Documents

Publication Publication Date Title
US20220379389A1 (en) Endmill specification design method, cutting condition detecting method, and processing method
CN102089106B (en) Method of cutting tree-shaped groove and rotary cutting tool
JP5108106B2 (en) Throw-away cutting rotary tool
JP5198579B2 (en) Throw-away cutting rotary tool
JP5908386B2 (en) Machine Tools
JP2010173007A (en) Drill and cutting method using the same
JP2018140485A (en) Helical broach and inner-gear processing method using the same
JP2014087887A (en) Machine tool
US20160114449A1 (en) Method of controlling feed axes in machine tool, and machine tool performing machining by using the method of controlling feed axes
JP4753893B2 (en) Diamond reamer
CN110076377B (en) Method for improving machining efficiency of titanium alloy material groove cavity round angle
CN111570878A (en) High-speed rough milling method for impeller
US11338374B2 (en) Method for manufacturing a thin-walled part
JP2013202748A (en) End mill
JP2013111735A (en) Method of processing deep hole
WO2010023760A1 (en) Throw-away cutting rotary tool
JP2020040179A (en) Method of machining wall surface of rib groove and tapered end mill
JP2012091259A (en) End mill
Hsu et al. Effect analysis and optimal combination of cutting conditions on the cutting torque of tapping processes using Taguchi methods
JP7315178B2 (en) End mill specification setting method, machining condition setting method, and machining method using the same
CN110712066A (en) Method suitable for monitoring cutter state in deep hole internal thread machining
JP5964261B2 (en) Machining method of thin plate workpiece with milling tool
JP5426572B2 (en) Throw-away cutting rotary tool
JP2015182192A (en) Luffing end mill

Legal Events

Date Code Title Description
AS Assignment

Owner name: MITSUBISHI HEAVY INDUSTRIES, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ETO, JUN;REEL/FRAME:050857/0422

Effective date: 20190729

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION