Method for deburring bevel gears and CNC gear-cutting machine having corresponding software for deburring
10695851 · 2020-06-30
Assignee
Inventors
Cpc classification
Y02P70/10
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
B23F9/00
PERFORMING OPERATIONS; TRANSPORTING
B23F23/006
PERFORMING OPERATIONS; TRANSPORTING
International classification
B23F17/00
PERFORMING OPERATIONS; TRANSPORTING
B23F19/10
PERFORMING OPERATIONS; TRANSPORTING
B23F19/00
PERFORMING OPERATIONS; TRANSPORTING
B23F9/00
PERFORMING OPERATIONS; TRANSPORTING
B23F23/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A method for deburring bevel gears using a deburring tool, which comprises at least one cutting edge, having the following steps: rotationally driving the deburring tool around a deburring spindle axis, rotationally driving a bevel gear around a workpiece spindle axis, wherein the rotational driving of the deburring tool and the rotational driving of the bevel gear take place in a coupled manner with an inverse coupling transmission ratio, it is a continuous method for deburring, in which the cutting edge executes a relative flight movement in relation to the bevel gear, the relative flight movement is defined by a hypocycloid, and wherein a burr is removed at least on one tooth edge of a tooth gap in the region of the bevel gear toe and/or the bevel gear heel by a cutting contact of the cutting edge with the tooth edge.
Claims
1. A method comprising: deburring in a continuous method a bevel gear defining a bevel gear heel, a bevel gear toe, at least one tooth and at least one tooth gap defining at least one tooth edge, by using a deburring tool including at least one cutting edge, the deburring step comprising: rotationally driving the deburring tool around a deburring spindle axis, rotationally driving the bevel gear around a workpiece spindle axis in a coupled manner with said rotationally driving the deburring tool using an inverse coupling transmission ratio, executing a relative flight movement of the at least one cutting edge relative to the bevel gear, wherein the relative flight movement is defined by a hypocycloid, and removing at least one burr located at or near one or more of the bevel gear heel or the bevel gear toe from at least one of the at least one tooth edge by cuttingly contacting the at least one cutting edge with the at least one of the at least one tooth edge.
2. A method according to claim 1, wherein the at least one tooth includes a tooth base and a tooth head, and the executing step includes executing the relative flight movement of the at least one cutting edge in the at least one tooth gap from at or near the tooth base and in a direction towards the tooth head.
3. A method according to claim 1, wherein the inverse coupling transmission ratio is defined by a hypocycloid coupling.
4. A method according to claim 1, wherein the deburring tool defines a number of threads and the at least one tooth defines a number of teeth, and the inverse coupling transmission ratio is defined by the number of teeth and the number of threads.
5. A method according to claim 2, including performing the cuttingly contacting step by said step of executing the relative flight movement of the at least one cutting edge in the at least one tooth gap, and thereby removing the at least one burr from the at least one of the at least one tooth edge.
6. A method according to claim 5, including executing the relative flight movement of the at least one cutting edge so that the at least one of at the at least one tooth edge and the at least one cutting edge move away relative to each other after the cuttingly contacting step.
7. A method according to claim 1, further including using the inverse coupling transmission ratio during the deburring step to automatically reduce a chamfer that results at or near the at least one of the at least one tooth edge when the deburring tool starts to lag.
8. A method according to claim 2, wherein the inverse coupling transmission ratio is defined by a hypocycloid coupling.
9. A method according to claim 2, wherein the deburring tool defines a number of threads and the at least one tooth defines a number of teeth, and the inverse coupling transmission ratio is defined by the number of teeth and the number of threads.
10. A method according to claim 2, further including using the inverse coupling transmission ratio during the deburring step to automatically reduce a chamfer that results at or near the at least one of the at least one tooth edge when the deburring tool starts to lag.
11. A method according to claim 3, wherein the deburring tool defines a number of threads and the at least one tooth defines a number of teeth, and the inverse coupling transmission ratio is defined by the number of teeth and the number of threads.
12. A method according to claim 3, further including using the inverse coupling transmission ratio during the deburring step to automatically reduce a chamfer that results at or near the at least one of the at least one tooth edge when the deburring tool starts to lag.
13. A method according to claim 4, further including using the inverse coupling transmission ratio during the deburring step to automatically reduce a chamfer that results at or near the at least one of the at least one tooth edge when the deburring tool starts to lag.
14. A CNC gear-cutting machine comprising: a workpiece spindle configured to mount and rotationally drive a workpiece, at least six axes, and a software module, wherein the CNC gear-cutting machine is configured to execute the following steps: deburring in a continuous method a bevel gear defining a bevel gear heel, a bevel gear toe, at least one tooth and at least one tooth gap defining at least one tooth edge, by using a deburring tool including at least one cutting edge, the deburring step comprising: rotationally driving the deburring tool around a deburring spindle axis, rotationally driving the bevel gear around a workpiece spindle axis in a coupled manner with said rotationally driving the deburring tool using an inverse coupling transmission ratio, executing a relative flight movement of the at least one cutting edge relative to the bevel gear, wherein the relative flight movement is defined by a hypocycloid, and removing at least one burr located at or near one or more of the bevel gear heel and the bevel gear toe from at least one of the at least one tooth edge by cuttingly contacting the at least one cutting edge with the at least one of the at least one tooth edge.
15. A CNC gear-cutting machine according to claim 14, wherein the software module is configured to predefine an inverse coupling transmission ratio defining the hypocycloid relative flight movement.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Other advantages and features will become apparent from the following detailed description, which are to be understood not to be limiting, and are described in more detail below with reference to the drawings.
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
DETAILED DESCRIPTION
(16) A schematic perspective view of a bevel gear 10 is shown in
(17)
(18) In each of the mentioned figures, only a part of the main body of a bevel gear pinion 10 can be seen in schematic form. A single tooth gap 14 is indicated in the material of the main body. The examples shown are bevel gears 10 having curved flank longitudinal line, as can be seen from the profile of the teeth 15.r and 15.1. The bevel gears 10 of
(19) At least some embodiments may be applied not only to spiral-toothed bevel gears 10, but rather also to other bevel gears 10, cylindrical spur gears, beveloids, crown gears, and also to inner gear teeth.
(20) The bevel gear pinion 10 has a main body in each of the examples shown, which is defined by two truncated cones having corresponding cone lateral surfaces. These cone lateral surfaces, to be precise, are truncated cone lateral surfaces. The two truncated cones are arranged coaxially to the workpiece spindle axis B. The workpiece spindle axis B can be seen in
(21) The teeth 15.r. and 15.1 of the bevel gear 10 extend along the head truncated cone lateral surface. The truncated cone lateral surface identified with the reference sign 17 in
(22) For example, in the transition region from the teeth 15.r. and 15.1 to the truncated cone lateral surface 17, primary burrs 20 can arise during the cutting machining (referred to here as gear-cutting or gear-cutting machining) (see
(23) The burrs 20 form above all at the concave tooth flanks 16.r in the region of the heel Fe and at the convex tooth flanks 16.1 in the region of the toe Ze. However, it is to be noted that burrs 20 can occur both at the tooth flanks and also at the tooth base 18 of a tooth gap 14.
(24) To now be able to remove the burr 20, the bevel gear 10 is deburred in a bevel gear gear-cutting machine 200 (see, for example,
(25) rotationally driving the deburring tool 40 around a deburring spindle axis Q1 (see, for example,
(26) rotationally driving the bevel gear 10 around a workpiece spindle axis B (see, for example,
(27) The rotational driving of the deburring tool 40 and the rotational driving of the bevel gear 10 is carried out in a coupled manner using an inverse coupling transmission ratio in at least some embodiments. The coupling transmission ratio can be defined, for example, as the ratio of the rolling circle radius r to the base circle radius R.
(28) In addition, it is to be noted that it is a continuous method for deburring, in which the at least one cutting edge 41 of the deburring tool 40, in relation to the bevel gear 10, executes a relative flight movement having a movement direction of the cutting edge 41 from the base F to the head K (deburring from the outside to the inside into the tooth gap 14) or from the head K to the base F (deburring from the inside to the outside out of the tooth gap 14), wherein the flight movement is mathematically defined by a hypocycloid Hy in three-dimensional space.
(29) In the scope of the continuous deburring method, a chamfer 12 is created at least on one tooth edge (for example, on the tooth edge 11.1 or 11.2) of a tooth gap 14, for example, in the region of the heel Fe by a cutting contact of the cutting edge 41 with the tooth edge 11.1 or 11.2 (this chamfer 12 is colored gray in
(30) Neither the deburring tool 40 nor a cutting edge 41 of the deburring tool 40 are shown in
(31) A deburring cutter 61 is shown in schematic form in five different positions in
(32) Since the deburring cutter 61 is guided from the outside to the inside into the tooth gap 14 in this embodiment, in
(33) The state at the time t=t3 is shown in
(34) The instantaneous movement direction is indicated by the block arrow P2 in each of
(35) As already mentioned, this is a continuous deburring procedure. A continuous deburring procedure is a procedure in which the bevel gear 10 and the deburring tool 40 rotate coupled in engagement with one another. The bevel gear 10 rotates in this case around the workpiece spindle axis B and the deburring tool 40 rotates around the deburring spindle axis Q1. I.e., there is a movement coupling (kinematic coupling) between the bevel gear 10 and the deburring tool 40. During the deburring, the deburring tool 40 and the bevel gear 10 rotate with a coupling transmission ratio exactly adapted to one another.
(36) In at least some embodiments, an electronic coupling is used between the two rotational drives of the bevel gear 10 and the deburring tool 40.
(37) In at least some embodiments, an inverse coupling transmission ratio is used and the tool track (also referred to as the flight path here), which a cutting head 63 of a deburring cutter 61 describes in three-dimensional space, follows a hypocycloid Hy.
(38) The coupling transmission ratio is selected so that a first deburring cutter 61 of the deburring tool 40 is moved, for example, from the outside to the inside through a first tooth gap 14 of the bevel gear 10. A second deburring cutter 61 of the deburring tool 40 is moved from the outside to the inside, for example, through the next tooth gap 14 of the bevel gear 10, etc.
(39) In at least some embodiments, the cutting edges 41 are on a circle on the deburring tool 40. The cutting wedge (referred to as cutting head 63 here) is placed on the bar-shaped shaft 62 of the deburring cutter 61 so that a reasonable rake angle and positive clearance angles result.
(40) A further embodiment is shown in
(41) As indicated in
(42) In contrast to an epicycloid, which is generated by rolling a rolling circle on the outside of a base circle, a hypocycloid Hy is generated by rolling a rolling circle RK on the inside in a base circle GK (details can be inferred from
(43) In at least some embodiments, the parameters of the hypocycloid HY are selected so that the hypocycloid HY has multiple loops which face radially outward, while the loops face radially inward in the epicycloid.
(44) A hypocycloid Hy is shown as an example in
(45) In
(46) The envelope EH shown essentially describes the movement of the cutting head 63 from outside the tooth gap 14 into the tooth gap 14. It can be seen clearly in
(47) As already described, a portion of a further bevel gear 10 during the deburring is shown in
(48) To be able to better illustrate the movement sequences and the relationships, the rotational directions of the deburring tool 40 and the bevel gear 10 are indicated by the curved arrows 1 and 2.
(49) In the exemplary embodiment having tooth gaps 14 extending in a left spiral shown in
(50) It can be seen here that the tooth edge 11.1 or 11.2 to be deburred moves away from the envelope EH due to the inverse coupling. If the deburring tool 40 should lag, the cutting edge 41 of the cutting head 63 thus would not eat deeper into the material of the bevel gear 10.
(51) If a procedure for deburring from the inside to the outside is selected, the deburring tool 40 is then guided out of the tooth gap 14 outward along a hypocycloid flight path. If one maintains the movement direction 2 of
(52) In the illustrations of
(53) In a CNC gear-cutting machine 200, as shown in
(54) The inverse coupling or the coupling transmission ratio, respectively, is selected so that a brief cutting contact only occurs in each case in the region of the tooth edges to be deburred (11.1 or 11.2) between the deburring tool 40 and the bevel gear 10. The coupling transmission ratio is defined by the ratio of the two radii R and r.
(55) In at least some embodiments, the inverse coupling transmission ratio is selected so that the hypocycloid flight path has a longer extension in the region of the loops in comparison to an epicycloid flight path which was generated using the same parameters. This will be explained further hereafter on the basis of an exemplary comparison of the loops of a hypocycloid Hy and an epicycloid Ep. In
(56)
(57) However, the principle of at least some embodiments may also be applied to other CNC gear-cutting machines 200 which are equipped with a deburring device 50, as shown in
(58) The CNC gear-cutting machine 200 can be constructed as follows. The machine 200 can comprise a machine housing 201, which enables it to guide a tool spindle 204 linearly vertically along a coordinate axis X (first axis), linearly horizontally along a coordinate axis Y (second axis), and linearly horizontally along a coordinate axis Z (third axis). The mentioned tool spindle 204 can be arranged hanging on the machine 200, for example, wherein the corresponding tool spindle axis A (fourth axis) hangs vertically in space. The tool spindle 204 bears a tool, a cutterhead 204 having multiple bar cutters here by way of example (the bar cutters are not visible).
(59) A first pivot device 203 can be provided on the machine 200, for example, which bears a workpiece spindle 205 having a workpiece spindle axis B (fifth axis). The workpiece spindle 205 including workpiece spindle axis B can be pivoted around a pivot axis (C axis; sixth axis) of the first pivot device 203. The pivot axis C is perpendicular to the tool spindle axis A and extends horizontally in space here. If one looks at the machine 200 of
(60) The workpiece spindle 205 bears a spiral-toothed bevel gear pinion as the workpiece 10 in the example shown. A clamping device 13 can be used for connecting the bevel gear 10 to the workpiece spindle 205.
(61) The first pivot device 203 can be mounted so it is pivotable around the C axis, for example, so that the bevel gear 10 is pivotable into a machining position below the gear-cutting tool 202. Moreover, the bevel gear 10 can be transferred by the first pivot device 203 into a suitable position in relation to the deburring tool 40 of the deburring device 50 for deburring.
(62) Moreover, the deburring device 50 can be provided, for example, with infeed device(s), to be able to move the deburring device 40 in relation to the bevel gear 10 and bring it into interaction therewith.
(63) The infeed device can comprise, for example, in at least some embodiments a linear axis X2, as shown by way of example in
(64) The deburring device 50 of at least some embodiments, which comprises a deburring cutterhead 40, can comprise, for example, a linear axis X2 (seventh axis) and a deburring spindle axis Q1 (eighth axis) as shown in
(65) The machine 200 is designed so that in at least some embodiments the bevel gear 10 and the deburring tool 40 can be rotationally driven in an inversely coupled manner, wherein this coupling is defined by a coupling transmission ratio.
(66) Using one or more of the mentioned axes, the deburring tool 40 can be moved into a starting position suitable for the deburring in relation to the bevel gear 10.
(67) The bevel gear 10 is then rotationally driven about the workpiece spindle axis B and the deburring tool 40 is rotationally driven about the deburring spindle axis Q1 in a coupled manner and they are moved in relation to one another. In a continuous method, the cutting edges of the deburring tool 40 (for example, the cutting edges 41 of the deburring cutter 61 of the deburring cutterhead 40) execute corresponding deburring movements from the outside to the inside on the predetermined edges 11.1 and/or 11.2 of the bevel gear 10.
(68) The pivot axis D can also have a different orientation in space in at least some embodiments, however. The specific arrangement of the optional pivot axis D is dependent on the overall configuration of all axes of the machine 200, to move the workpiece 10 and the deburring tool 40 in relation to one another so that a suitable deburring movement can be executed along a hypocycloid Hy.
(69) To be able to implement the chamfering/deburring in the continuous method, bevel gear gear-cutting machines 200 having at least six numerically controlled axes are used in at least some embodiments, as shown by way of example in
(70) However, other CNC bevel gear gear-cutting machines 200 can also be refitted or equipped according to at least some embodiments, where machines having seven, eight, or nine numerically controlled axes are used, as was already explained on the basis of
(71) The deburring device 50 comprises, for example, in at least some embodiments a deburring spindle 51 having the above-mentioned deburring spindle axis Q1, which has a horizontal orientation here in the example shown. A deburring tool 40 can be fastened on the deburring spindle 51, as shown in
(72) In at least some embodiments, the bar cutters 61 are arranged offset slightly diagonally on the deburring cutterhead 40, so that the longitudinal axes of the cutter shafts 62 do not intersect the spindle axis Q1. On the one hand, the individual bar cutters 61 may be fastened better on the deburring cutterhead 40 due to this offset arrangement and, on the other hand, the rake surface on the cutting head 63 can be aligned optimally in relation to the cutting direction.
(73) Numerically controllable axes in this context are axes which are controllable via a programmable controller. The numerically controllable axes are designed and arranged so that by way of the adjustment of at least one of the axes, the workpiece spindle 205 including the bevel gear 10 is movable in relation to the deburring tool 40 so that cutting edges 41 of the deburring tool 40, with simultaneous coupled, inverse rotation of the workpiece spindle 205 around the workpiece spindle axis B and the deburring tool 40 around the deburring spindle axis Q1, plunge in succession from the outside to the inside into tooth gaps 14 of adjacent teeth 15.r, 15.1 of the bevel gear 10 and execute a deburring movement in relation to the predefined tooth edges 11.1, 11.2 of the bevel gear 10.
(74) As indicated in
(75) According to at least some embodiments, one or more of the numerically controlled axes are used to move the cutting edges 41 of the deburring tool 40 in relation to the workpiece 10.
(76) Since the bevel gear 10 rotates at a predefined first angular velocity 2 around the workpiece axis B and the deburring tool 60.1 rotates at a second angular velocity 1 around the deburring spindle axis Q1 and since the two rotational movements take place in opposite directions in an (electronically) coupled manner, complex helical flight paths in three-dimensional space result for the cutter inserts 61 of the deburring tool 40, as shown on the basis of the envelope EH.
(77) The example of a suitable deburring cutterhead 40 can be inferred from granted European patent EP1598137 B1. A corresponding deburring cutterhead 40 is shown in
(78) An embodiment of a deburring cutterhead 40, as shown in
(79) While the above describes certain embodiments, those skilled in the art should understand that the foregoing description is not intended to limit the spirit or scope of the present disclosure. It should also be understood that the embodiments of the present disclosure described herein are merely exemplary and that a person skilled in the art may make any variations and modification without departing from the spirit and scope of the disclosure. All such variations and modifications, including those discussed above, are intended to be included within the scope of the disclosure.