A kind of overlikon spiral bevel gear processing method
Technical field:
The present invention relates to Machining Spiral Bevel Gear field, be specially a kind of overlikon spiral bevel gear processing method.
Background technology:
Overlikon spiral bevel gear is gained the name because its product shape wheel tooth trace is cyclo-palloid curve.This kind of gear is equal-depth teeth, adopts plane to produce shape wheel continuous division (Face-hobbing) processing.The processing method of overlikon spiral bevel gear mainly contains two kinds, is the split cutterhead method of German crin Gen Beierge (Klingelnberg) company respectively, Spirac and the Spiroflex method of Switzerland Ao Likang (Oerlikon) company.
Overlikon spiral bevel gear imaginary plane produce shape wheel generating surface Forming Theory: cutterhead and produce shape wheel respectively have one round as a ball, relative to the motion of producing shape wheel, cutterhead can be regarded that cutterhead is round as a ball as and make pure rolling on product shape wheel is round as a ball, i.e. cutterhead rolling diameter and produce the ratio that shape take turns rolling diameter and equal cutterhead cutter tooth group number and produce the ratio of shape tooth number.When cutterhead is round as a ball on producing shape wheel and be round as a ball during pure rolling, blade take turns relative to product shape the curved surface scanned out and is and produces the shape wheel flank of tooth, and the point on blade is cyclo-palloid curve producing the track that shape takes turns in plane.The flank of tooth of processed gear forms by producing shape gear teeth bread network.In actual processing, produce shape wheel with the representative of lathe shaking tray, its cutterhead cutter tooth is divided into some groups, and often group has an interior cutter and an outer cutter at least, processes convex surface and the concave surface of processed gear respectively.
Overlikon spiral bevel gear can process the gear pair of total conjugated in theory, but in order to realize the localized contact of actual requirement, Klingelnberg adopts the split cutterhead that frame for movement is very complicated, and Oerlikon adopts and calculates complicated tilt method.At present, split type cutterhead and arc edge combine by Klingelnberg, carry out the correction of the flank shape of tooth depth direction by arc edge, realize " cydariform " of tooth length direction by changing inside and outside cutter axis eccentric throw.
Near Gleason and Klingelnberg has invented the numerical control bevel gear lathe of six-axis linkage, eliminates lathe shaking tray during the last ten years, and adopt carbide alloy pointed tooth bar solid cutter hypoid format tilt processing overlikon spiral bevel gear, part lathe can high-speed dry be cut.But the theoretical foundation of processing method does not all have the change of internal.
In sum, existing overlikon spiral bevel gear processing method mainly contains following limitation:
1) Klingelnberg adopts split type cutterhead, and inside and outside cutter tooth is contained in two pieces independently on cutter hub respectively, mutually embeds and stacks, and realize inside and outside cutter hub by cross slides eccentric, structure is very complicated, and design difficulty of processing is large.Split type cutterhead and crosshead shoe structure cause lathe rigidity poor, and meanwhile, split type cutterhead can not carry out high-speed dry and cut processing;
2) Oerlikon adopts hypoid format tilt processing, overcomes " gram " defect processed, but lathe increases tilt swivel mechanism, and machine tool structure is complicated and calculating adjustment is complicated;
Tradition Klingelnberg and Oerlikon method all directly can not specify the position of contact zone, needs trial cut repeatedly, and the contact (area) pattern of gear pair and curve movement control difficulty.
Summary of the invention:
The object of the present invention is to provide a kind of overlikon spiral bevel gear processing method, process overlikon spiral bevel gear and hypoid gear, to overcome the limitation of above-mentioned conventional machining techniques without on tilt shaking tray class bevel gear tooth milling machine.
To achieve these goals, the present invention adopts following technical scheme:
A kind of overlikon spiral bevel gear processing method, comprises the following steps:
(1), determine to produce shape wheel basic parameter: comprise the number of teeth, Mean radius and mean spiral angle;
(2), determine that producing shape takes turns the ratio with cutter corner;
(3), the ratio producing shape wheel angular speed and processed gear angular speed is determined;
(4), the motion of producing shape wheel Generating gear is revised;
(5) generate to processed gear, is completed.
The present invention further improves and is: producing shape tooth number in step (1) is z
p, its computing formula is:
Z
1for little tooth number, z
2for large tooth number; θ
kfor gear pair pitch cone angle correction, δ
01for steamboat pitch cone angle, δ
02for bull wheel pitch cone angle.
The present invention further improves and is: producing shape wheel in step (2) is i with the ratio of cutter corner
pk, its computing formula is:
Z
0for cutterhead number; z
pfor producing shape tooth number.
The present invention further improves and is: producing shape wheel angular speed in step (3) is i with the ratio of processed gear angular speed
pi, its computing formula is:
Z
ifor the processed gear number of teeth; z
pfor producing shape tooth number.
The present invention further improves and is: revising described in step (4) is control cutting depth, the angled change of cutting-in travelling with the exhibits on an exhibition tour and changing producing shape wheel Generating gear while.
The present invention further improves and is: when revising in step (4), except guarantee reference point cutting-in is except theoretical value, and all the other cutting-in all comparatively theoretical value increases everywhere.
The present invention further improves and is: the correction in tooth depth direction is by realizing the adjustment in direction of product shape wheel tooth depth, and the correction in facewidth direction is realized by cutting-in change additional in the motion of producing shape wheel Generating gear.
The present invention further improves and is: revise the motion of producing shape wheel Generating gear in step (4), cutting-in increment x
bfor generate angle
high order even multinomial, real cutting depth
h is cutting-in theoretical value,
for generate angle, n is even number, c
nfor being longitudinal cydariform correction factor.
The present invention further improves and is: the second order exposure parameter of the second order C coefficient gear pair reference point as requested in cutter tooth cutting edge arc radius ρ and cutting-in function calculates, and carries out chamfering with high-order C coefficient to the flank of tooth.
The present invention further improves and is: step (5) specifically comprises the following steps: first, according to the required precision of flank of tooth envelope, optimize in the product shape wheel angle range needed and determine that one group is produced shape wheel angle position data, obtains the corresponding angle position of processed gear and additional cutting-in incremental data; Produce the optimization position of shape wheel and processed gear at each, the Tool in Cutting degree of depth is constant, and cutter and processed gear are pressed constant velocity-ratio and rotated, and processes processed gear and takes turns with product shape the part flank of tooth engaged in this position; Cutter and processed gear move to next relative position again, repeat the motion of above-mentioned cutter and processed gear, until complete the position that all optimization determines, just complete the generate of processed gear.
The present invention further improves and is: the cutter adopted in the generate process of processed gear is monoblock type cutterhead, and this monoblock type cutterhead is provided with some internal cuttves and outer cutter; Interior cutter and outer cutter adopt arc edge; Interior cutter is identical with the nominal radius of outer cutter, and rotation direction is contrary, and inside and outside cutter profile angle is contrary; Outer cutter profile angle is identical with the normal pressure angle of processed gear concave surface, and interior cutter profile angle is identical with the normal pressure angle of processed gear convex surface.
The present invention further improves and is: the nominal radius of two cutterheads of processing coupling gear is identical with head number, and rotation direction is contrary, and profile angle is compatible, and namely left-handed interior cutter profile angle equals cutter profile angle, left-handed outer cutter profile angle outside dextrorotation and equals cutter profile angle in dextrorotation.
In step (4), the motion of producing shape wheel generate gear wheel, the motion one of them or both that produce shape wheel generate steamboat are revised simultaneously.
Now for prior art, the present invention has following beneficial effect:
(1) relative to Klingelnberg method, adopt integral type cutterhead of the present invention or existing integral type cutterhead, cutter head structure greatly simplifies, and does not need cross slides, and rigidity improves; Relative to Oerlikon method, Bu Xu tilt mechanism, machine tool structure greatly simplifies, and rigidity improves;
(2) overlikon spiral bevel gear and hypoid gear can processed without on tilt shaking tray class bevel gear tooth milling machine;
(3) Tooth Face Correction does not cause the additional adjustment of lathe and cutter, the angled change of cutting-in travelling with the exhibits on an exhibition tour and changing, and this moves through numerical control four-axis interlock and realizes;
(4) position of face spot, the second order pre-control of size and shape can be realized;
(5) the second order pre-control of the transmission error required can be realized;
(6) overlikon spiral bevel gear that also can process total conjugated is in theory secondary.
Accompanying drawing illustrates:
Fig. 1 (a) is the outline drawing of rectilinear edge of the present invention; Fig. 1 (b) is the outline drawing of Roound edge of the present invention.
Fig. 2 is that plane of the present invention produces shape wheel schematic diagram;
Fig. 3 is that cutterhead of the present invention takes turns movement relation schematic diagram with product shape.
The dextrorotation cutterhead inner edge schematic diagram that Fig. 4 (a) adopts for the embodiment of the present invention; The dextrorotation cutterhead outside schematic diagram that Fig. 4 (b) adopts for the embodiment of the present invention.
Wherein: 1 is steamboat; 2 is bull wheel; 3 produce shape for plane takes turns.
Detailed description of the invention:
Below in conjunction with accompanying drawing, the present invention is described in further detail:
Relative to prior art, a kind of overlikon spiral bevel gear processing method of the present invention has following difference:
(1) cutter adopted is overall disk cutter, and its diameter is chosen according to processed gear diameter and the facewidth.The cutter of the secondary large steamboat of machining gears: nominal radius is identical, and rotation direction is contrary, and inside and outside cutter profile angle is contrary.The profile angle of cutter for same: outer cutter profile angle is identical with the normal pressure angle of processed gear concave surface, interior cutter profile angle is identical with the normal pressure angle of processed gear convex surface.Tool in Cutting sword adopts circular arc to replace straight line, and as shown in Fig. 1 (b), arc edge and existing straight line point of contact are at effective knife up mid point, and this is and one of existing method difference.
(2) motion of the product shape wheel Generating gear adopted is control cutting depth while product shape wheel Generating gear, the angled change of cutting-in travelling with the exhibits on an exhibition tour and changing, as shown in Figure 4, this forms of motion is linked by numerical control four-axis and realizes, and this is and existing method difference two.
(3) the product shape wheel adopted is require determined by the contact zone of processed gear with the movement relation of cutter, center, contact zone can directly be specified, thus the position of contact (area) pattern, the second order pre-control of size and shape can be realized, can obtain the driving error met the demands, this is and existing method difference three simultaneously.
Refer to shown in Fig. 1 (a) to Fig. 4 (b), a kind of overlikon spiral bevel gear processing method of the present invention, comprises the following steps:
(1) determine to produce shape wheel basic parameter, comprise the number of teeth, Mean radius and mean spiral angle, see Fig. 2.Determine according to the following formula to produce shape wheel basic parameter:
Z
pfor producing shape tooth number, z
1for little tooth number, z
2for large tooth number; θ
kby intermeshing steamboat and bull wheel are formed gear pair pitch cone angle correction, δ
01for steamboat pitch cone angle, δ
02for bull wheel pitch cone angle.Produce shape wheel Mean radius and equal gear pair mean cone distance R
m, mean spiral angle equals gear pair mean spiral angle β
m, mid point tooth pitch equals gear pair mid point tooth pitch; To hypoid gear, the above-mentioned parameter producing shape wheel all gets bull wheel relevant parameter.
(2) determine to be formed the motion of producing the shape wheel flank of tooth: produce shape wheel and the ratio of cutter corner equals cutterhead number and produces the ratio of shape tooth number, tool position and the two turn to relation to see Fig. 3.
(3) determine produce shape wheel Generating gear motion: generating motion be produce shape wheel with processed gear by fixed than rotating, speed ratio is the inverse of gear ratio.
(4) motion of producing shape wheel Generating gear is revised, described correction refers to that cutting depth changes with the wheel angled change of exhibition of product shape, except ensureing that a bit (reference point) cutting-in is except nominal value, all the other cutting-in all comparatively theoretical value increases everywhere, cutting-in variable quantity requires to calculate according to contact zone.The motion of producing shape wheel Generating gear is revised, gets cutting-in increment x
bfor opening up angled quadratic function, try to achieve cutting-in h
wexpression formula is
h is nominal value,
for generate angle.
(5) complete the generate to processed gear, first determine to want the product shape wheel angle range of the processed gear of complete envelope and corresponding processed gear angle range.Optimize in the product shape wheel angle range needed according to the required precision of flank of tooth envelope and determine that one group is produced shape wheel angle position data, obtains the corresponding angle position of processed gear and additional cutting-in incremental data.Produce the optimization position of shape wheel and processed gear at each, the Tool in Cutting degree of depth is constant, and cutter and processed gear are pressed constant velocity-ratio and rotated, and processes processed gear and takes turns with product shape the part flank of tooth engaged in this position; Cutter and processed gear move to next relative position again, repeat the motion of above-mentioned cutter and processed gear, until complete the position that all optimization determines, just complete the generate of processed gear.
Embodiment: machined a pair cycloid tooth hypoid gear with described disk cutter as stated above.Gear pair crossed axis angle Σ=90 °, offset a
v=25mm, large tooth number z
2=39, little tooth number z
1=8, the outer pitch diameter d of bull wheel
02=265mm, mean spiral angle β
m2=34.63 °, average pressure angle α
n=21.5 °, facewidth b
2=40mm.Cutter parameters (see Fig. 4), cutter radius: r
c=106.5mm, cutterhead head number: z
0=5, tool-tooth profile angle: cutter α in steamboat
ni=22 °, the outer cutter α of steamboat
ne=20.5 °; Bull wheel cutter adopts rectilinear edge, and pressure angle is contrary with steamboat.
Specifically be implemented as follows:
(1) determine to produce shape wheel basic parameter
Mean radius R
mequal gear pair mean cone distance
Mean spiral angle equals bull wheel helixangleβ
m, be 34.63 degree.
(2) determine to be formed the motion of producing the shape wheel flank of tooth, produce shape and take turns the ratio i with cutter corner
pkfor
(3) motion of producing shape wheel Generating gear is determined
The ratio i of shape wheel angular speed and steamboat angular speed is produced during processing steamboat
p1for
The ratio i of shape wheel angular speed and steamboat angular speed is produced during processing steamboat
p2for
(4) revise the motion of producing shape wheel Generating gear, the present embodiment gets cutting-in increment x
bfor opening up angled quadratic function, trying to achieve cutting-in expression formula is
(5) generate to processed gear is completed.
The product shape wheel angle range of the complete teeth groove of processing steamboat: (15.017 ° ,-16.658 °);
The product shape wheel angle range of the complete teeth groove of processing bull wheel: (-25.735 °, 15.016 °).
Above content is in conjunction with concrete preferred embodiment further description made for the present invention; can not assert that the specific embodiment of the present invention is only limitted to this; for general technical staff of the technical field of the invention; without departing from the inventive concept of the premise; some simple deduction or replace can also be made, all should be considered as belonging to the present invention by submitted to claims determination scope of patent protection.