US3715938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling a cycle of operations for machining a rotary workpiece
Assignee: DMG Mori AG
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Filing: 1970-10-28
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Granted: 1973-02-13
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Expires: 1990-10-28
Abstract
Abstract A method for machining a rotary workpiece in radial and axial directions under the control of electronic program control means in which the maximum and minimum permissible reference values are stored, and which responds to signals of measuring devices representing the torque applied by the main spindle and workpiece to the cutting tool, advance rates of the tool, the cutting force, and other operational data. When the tool cuts into the workpiece, the increased torque is measured and the rate of rapid feed of the tool reduces, or the tool is stopped, so that the tool is freed of the workpiece, whereupon the tool is advanced so that the measured torque increases to a maximum, whereupon the direction of movement is changed and the work piece is machined until the cutter no longer engages the work piece.
Inventors
- 👤 A Ledergerber
- 👤 W Plassmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:57
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/416; G05B19/4163; B; B23; B23B; B23B3/00; B23Q; B23Q5/00; B23Q5/22; B23Q5/34; B23Q2705/00; B23Q2705/10; B23Q2705/18; B23Q2705/182; Y; Y10; Y10T; Y10T82/00; Y10T82/10
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
270 words
A method of adaptively controlling a cycle of operations for machining on a rotary machine a workpiece rotating about an axis, wherein a desired contour of the workpiece is stored in electronic program control means, wherein during the cycle of operations the actual contour of the workpiece is compared by said program control means with the desired contour until the workpiece has the desired contour, and wherein the torque applied by the rotating workpiece to a tool is measured and corresponding information supplied to said program control means, the method comprising the steps of moving the tool in a rapid feed in axial direction toward the workpiece until the tool cuts into the workpiece whereby the torque required for rotating the workpiece is increased; measuring the increased torque, reducing in response to the increased torque the rate of rapid feed to a minimum advance rate stored in said program control means and including stopping the advance of the tool during at least one revolution of the workpiece so that the tool is freed of the workpiece; advancing the freed tool in said axial direction at an advance rate less than a maximum advance rate stored in said program control means so that the measured torque increases to a maximum torque stored in said program control means; and changing the direction of movement of the tool from the axial direction to a radial direction and machining the workpiece with said tool in said radial direction until at the end of the radial movement the cutting edge of the tool no longer fully engages the workpiece so that the torque is reduced.
Claim 2
Independent Claim
270 words
A method of adaptively controlling a cycle of operations for machining on a rotary machine a workpiece rotating about an axis, wherein a desired contour of the workpiece is stored in electronic program control means, wherein during the cycle of operations the actual contour of the workpiece is compared by said program control means with the desired contour until the workpiece has the desired contour, and wherein the torque applied by the rotating workpiece to a tool is measured and corresponding information supplied to said program control means, the method comprising the steps of moving the tool in a rapid feed in axial direction toward the workpiece until the tool cuts into the workpiece whereby the torque required for rotating the workpiece is increased; measuring the increased torque, reducing in response to the increased torque the rate of rapid feed to a minimum advance rate stored in said program control means and including stopping the advance of the tool during at least one revolution of the workpiece so that the tool is freed of the workpiece; advancing the freed tool in said axial direction at an advance rate less than a maximum advance rate stored in said program control means so that the measured torque increases to a maximum torque stored in said program control means; and changing the direction of movement of the tool from the axial direction to a radial direction and machining the workpiece with said tool in said radial direction until at the end of the radial movement the cutting edge of the tool no longer fully engages the workpiece so that the torque is reduced.
Claim 3
Independent Claim
270 words
A method of adaptively controlling a cycle of operations for machining on a rotary machine a workpiece rotating about an axis, wherein a desired contour of the workpiece is stored in electronic program control means, wherein during the cycle of operations the actual contour of the workpiece is compared by said program control means with the desired contour until the workpiece has the desired contour, and wherein the torque applied by the rotating workpiece to a tool is measured and corresponding information supplied to said program control means, the method comprising the steps of moving the tool in a rapid feed in axial direction toward the workpiece until the tool cuts into the workpiece whereby the torque required for rotating the workpiece is increased; measuring the increased torque, reducing in response to the increased torque the rate of rapid feed to a minimum advance rate stored in said program control means and including stopping the advance of the tool during at least one revolution of the workpiece so that the tool is freed of the workpiece; advancing the freed tool in said axial direction at an advance rate less than a maximum advance rate stored in said program control means so that the measured torque increases to a maximum torque stored in said program control means; and changing the direction of movement of the tool from the axial direction to a radial direction and machining the workpiece with said tool in said radial direction until at the end of the radial movement the cutting edge of the tool no longer fully engages the workpiece so that the torque is reduced.
Claim 4
Independent Claim
270 words
A method of adaptively controlling a cycle of operations for machining on a rotary machine a workpiece rotating about an axis, wherein a desired contour of the workpiece is stored in electronic program control means, wherein during the cycle of operations the actual contour of the workpiece is compared by said program control means with the desired contour until the workpiece has the desired contour, and wherein the torque applied by the rotating workpiece to a tool is measured and corresponding information supplied to said program control means, the method comprising the steps of moving the tool in a rapid feed in axial direction toward the workpiece until the tool cuts into the workpiece whereby the torque required for rotating the workpiece is increased; measuring the increased torque, reducing in response to the increased torque the rate of rapid feed to a minimum advance rate stored in said program control means and including stopping the advance of the tool during at least one revolution of the workpiece so that the tool is freed of the workpiece; advancing the freed tool in said axial direction at an advance rate less than a maximum advance rate stored in said program control means so that the measured torque increases to a maximum torque stored in said program control means; and changing the direction of movement of the tool from the axial direction to a radial direction and machining the workpiece with said tool in said radial direction until at the end of the radial movement the cutting edge of the tool no longer fully engages the workpiece so that the torque is reduced.
Claim 5
Dependent Claim
118 words
The method of claim 1 comprising, after changing the direction of the tool from the axial direction to a radial direction, machining the outside of the workpiece with said tool in said radial direction until at an increased radius of the cut and at an advance rate being reduced corresponding to the increase of the torque, the minimum advance rate is reached, and thereupon starting a reduction of the depth of cut by moving the tool at an advance rate corresponding to the desired depth of cut whereby the advance rate in said radial direction and the torque are increased; and reducing the advance rate when the maximum torque is reached so that the same is not exceeded.
Claim 6
Dependent Claim
45 words
The method of claim 2 wherein, if at the end of the radial movement the cutting edge of the tool no longer fully engages the workpiece so that the torque is reduced irrespective of the increasing radius, the tool is moved in the axial direction.
Claim 7
Dependent Claim
62 words
The method of claim 1 comprising, after changing the direction of movement of the tool from the axial direction to a radial direction, machining the inside of a workpiece with said tool in said radial direction until the cutting edge of the tool no longer fully engages the workpiece so that the torque is reduced more than is proportional during a cut.
Claim 8
Dependent Claim
27 words
The method of claim 4 comprising changing the direction of advance from the radial direction to the axial direction when the torque is reduced more than proportional.
Claim 9
Dependent Claim
85 words
The method of claim 1 comprising reducing the advance rate of the tool during movement in axial direction when the maximum torque is reached and measured so that the same is not exceeded, and reducing in the event that a minimum advance rate is reached, the depth of cut by moving the tool at an advance rate correlated with the reduced depth of cut, and increasing, when the depth of cut is reduced, the advance rate in said axial direction without exceeding the maximum torque.
Claim 10
Dependent Claim
82 words
The method of claim 1 comprising automatically increasing in response to the torque reduction the rate of advance in axial direction to a predetermined maximum advance rate stored in said program control means and upon reaching the maximum advance rate and a further reduction of the torque, adding an advance correlated with an increase of the depth of cut, and reducing the advance rate in said axial direction upon an increase of the depth of cut without exceeding the programmed maximum torque.
Claim 11
Dependent Claim
63 words
The method of claim 1 wherein said advance correlated with said increase of the depth of cut and said advance in the axial direction have such a ratio that, during the movement of the tool for increasing the depth of cut, a secondary cutting edge of the tool does not engage the workpiece surface cut by a primary cutting edge of the tool.
Claim 12
Dependent Claim
37 words
The method of claim 1 wherein the contour stored in said electronic program control means and obtained by coarse machining includes a finishing allowance layer; and wherein said finishing allowance layer is removed by a finishing operation.
Claim 13
Dependent Claim
41 words
The method of claim 9 wherein said tool includes a coarse cutter for cutting the contour including said layer, and finishing cutter offset from said coarse cutter and positioned to cut the final desired contour stored in said program control means.
Claim 14
Dependent Claim
42 words
The method of claim 1 wherein parts of the workpiece finished during a first cutting operation are passed by the tool moving at a rapid traverse rate, and including placing the tool in a cutting position engaging another part of the workpiece.
Claim 15
Dependent Claim
34 words
The method of claim 1 comprising stopping the tool so that an end zone of the workpiece finished during a previous cutting operation is not traversed by the tool during a following cutting operation.
Claim 16
Dependent Claim
44 words
The method of claim 1 comprising starting cutting operations at a starting point of the workpiece, cutting and finishing a zone following said starting point; and automatically starting an other cutting operation at a starting point advanced to the end of said finished zone.
Claim 17
Dependent Claim
40 words
The method of claim 1 wherein the variation of the differential quotient dMd/dx in which Md is the torque, is the basis for a control signal causing said program control means to change the direction of advance of the tool.
Claim 18
Dependent Claim
41 words
The method of claim 1 wherein said program control means responds to a change of the ratio between the increase of the advance rate of the tool and the radial distance which the tool moves to measure bluntness of the tool.
Claim 19
Dependent Claim
50 words
The method of claim 1 comprising continuing of the radial advance when the cutting tool is freed and no machining in axial direction is programmed so that no torque acts thereon; and wherein ending of the torque causes a signal to said program control means for starting another cutting operation.
Claim 20
Dependent Claim
35 words
The method of claim 1 wherein the tool operates on an inner surface of the workpiece; and wherein a signal indicating the ending of the torque is given when the inner surface is completely machined.
Claim 21
Dependent Claim
91 words
The method of claim 1 wherein the tool starts radial advance from a starting point located in the axis of the workpiece, and axial advance from a plane spaced from the end face of the workpiece the maximum permissible depth of cut; comprising moving the tool in a rapid feed in radial direction until the tool cuts into the workpiece whereby the torque is increased; and wherein the increase of torque causes a signal for recognition of the inNer contour of the workpiece blank so that the rapid feed is terminated.
Claim 22
Dependent Claim
48 words
The method of claim 18 comprising increasing the advance rate of the tool in radial direction after cutting free of the tool until at least one of two programmed maximum values is reached, said programmed maximum values including a programmed maximum torque and a programmed maximum advance rate.
Claim 23
Dependent Claim
43 words
The method of claim 1 wherein maximum programmed torque and the minimum advance rate cause a signal indicating bluntness of the tool; and comprising retracting of the tool from the workpiece under the control of the program control means when said signal occurs.
Claim 24
Dependent Claim
43 words
The method of claim 18 wherein the torque is measured by devices selectively located at the main spindle of the machine, at the tool, and at the tool holder; and comprising selectively interrogating said devices from said program control means by auxiliary signals.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |