SU1710174A1 - Method of rolling gears - Google Patents

Description

the roughing portion of the teeth of the tensioner 4 is brought out of contact with the workpiece 1, and the calibrated portion of the tensioner 4 is in simultaneous contact with the reference gear 5 and with the blackened teeth of the workpiece 1.

Axial and radial movements of the sector inductor 9 relative to the workpiece 1 provide the required rate of cooling of the workpiece 1. When the cooling toothed workpiece 1 and the tensioner 4 rotate each other, the gear ring of the workpiece 1 is continuously fed by thermal shrinkage to the gauge parts of the teeth of the tensioner 4, which deform the tops of the teeth The rough profile and with its envelopes of the shaping side surfaces redistribute the metal over the height of the workpiece 1, caliber them in half than the mode.

The knurling process ends in that at the temperature of the workpiece 1, which corresponds to the lower boundary of the half-mountain of which mode of processing, the roller 4 is taken out of engagement with the toothed workpiece 1. The semi-hot mode is optimal for calibration processes. The parameters of the tooth gauge nachatnika provide the required parameters of the tooth product. The parameters of the tooth of the rough section of the nakatnik correspond to the parameters of the tooth of the calibrating area. However, the height of the tooth head ha4 is selected on the basis of obtaining a greater height of the rough tooth by an amount that provides the necessary volume of metal to form the desired tooth profile during the calibration process.

During the cooling process, the tooth thickness of the workpiece is reduced due to thermal shrinkage of the metal. With mutual rotation, the nickle cavity comes into contact with the tooth tip, deforms it in the radial direction and feeds the metal into the tooth section above, which increases its thickness and introduces the tooth lateral surfaces in contact with the formative lateral surfaces of the teeth, which, with their envelope movement form the desired tooth profile, the redistribution of metal along its height. When calibrating the errors of the roughing rolls, the kinematic accuracy of the gears and the parameters characterizing the smoothness of the teeth work are increased. Figure 2 shows the height Lac of the teeth of the gauge portion of the nakatnik.

The formula for calculating the rate of cooling of the workpiece during the calibration of the teeth.

The required rate of cooling of the part during the calibration of the teeth can be determined by the expression

TNK TKK with

(one)

V,

ost

toCTс

de TNC is the temperature of the workpiece at the time of the beginning of the calibration of the ring gear (TNC 1100 ° C);

Tcc - the temperature of the workpiece at the time of the end of the process of calibrating the Tcc teeth);

tocT cooling time of the part, s

tocT- „: (2)

i cal

5kal - feed rate of the deformable surface of the workpiece to the nakatnik in the process of thermal shrinkage of the metal, mm / s;

Ad is the difference between the pitch diameters of the gear wreath of the workpiece when the temperature changes in the range of TNC - Tcc, mm,

 "T (Tick - TKK) d

d - diameter of the pitch circle of the gear teeth of the workpiece at TNC,

a.- coefficient of linear expansion (shrinkage) of the metal, is selected depending on the material of the rolling ring gear (3) j

o: t (8.1 ... 9.4)

(1+ at At) :( 4)

d is the pitch diameter of the gear rim of the original billet at, mm;

At g is the temperature difference between the initial and heated blanks to TNC, ° C.

It is recommended that the optimum value of a single reduction with a hot tooth calibration be equal to Ah (0.05., 0.1) m, mm, where m is the module of the engagement of the rolled teeth, mm. Ah 0.075 t is selected.

It is known that

Ah -, - g. N p

where S is the feed rate of the deformable metal of the workpiece in the radial direction;

N is the number of knuckles;

n is the speed of rotation of the workpiece, rev / s.

It is possible to write with S p. Thus, during calibration, the feed rate of the deformable metal 5 cal is found from the expression Zcal 0.075 t. Accelerating 1000 -V.

wah what n

where V is linear

- d

The speed of the workpiece on the diameter of the pitch circle d is selected depending on the applied module V 0.5 .., 0.13 mm / s, therefore 5kk 23.9 mV T Substituting the formulas in (1), get 47.8 m V o . “R (d) 2 It is known that the heating temperature of the workpiece is optimal in the process of teeth calibration TC 750 ... 770 ° C. According to the manufacture of teeth, the metal is fed to the knurling gears during calibration by shrinking the cooling metal of the workpiece. The optimal temperature of the workpiece Tk lies in the middle of the proposed temperature range, during which the process of tooth calibration from Tnc to Tcc BOOC is carried out. In this case, the temperature of TNC corresponds to the optimum temperature of the workpiece at which the recrystallization processes are most fully completed, and TCC is the temperature at which the recrystallization processes cease. Example. The device diagram (Fig. 1) is implemented on a SKQ8NC model of a two-post carousel. To the first group of the machine, the nakatnik 4 is fixed, and to the second, the sector inductor 9. The matrix 2 is fixed on the table of the machine. Knurling gear gear with internal clutch, having the following parameters: number of teeth Z 126, modulus m 3.5 mm. Dry profile, 28, tooth head height factor ha 0.95, radial clearance coefficient Co 0.2, displacement coefficient X 0. Ring billet outer diameter 491.0 mm, inner diameter 441.0 mm, crown width 60 mm. The material of the workpiece is steel 18HGT, the parameter of the teeth of the draft and the calibrating sections of the hub are equal and provide the required shape of the teeth of the rolled gear. The exception is the height of the head of the teeth. For the rough section of the indent and the nakatnik, it is equal to Lach ItGSm, and for the libration portion of the Nak 1.15 tons. The choice of the parameters of the roughing and 1sali & ng sections of the nakatnik allows creating radial gaps between the teeth of the baler and the nádnik at the beginning of the calibration process and then settling the teeth of the workpiece by means of a draft of the toothed profile. The temperature of the workpiece during roughing and at the start of calibration is t 1100 ° C, and at the end of the calibration process the teeth are 500 ° C. When calibrating the teeth of the workpiece, the speed of removal of the sector inductor from the product is selected from the condition of ensuring the rate of cooling of the treated surface, equal to 47.8 m V 47.8 -3.5 0.27 at (d) 2 8.7 -10 (445.1) 2, dd (H- "t Y th441 (1 + + 8,7-lO ® 1080) 445.1 mm. Using the proposed method allows: to increase processing performance and reduce energy costs associated with noBTOpHbiM heating the workpiece for finishing. Formulas and AND 30 shakes a method of rolling gear wheels, in which a sequential treatment is carried out, including in the workpieces, the roughing of the gear teeth with the height of the tooth profile exceeding the required one, and its subsequent finishing processing by shrinking, while finishing processing is carried out in a half mountain than the thermal regime using the temperature of the end of the roughing rolling, and since, in order to increase the machining performance of gears with internal gearing, the roughing and finishing of the gear rim is carried out in a single pass, at the same time a semi-helix thermal mode is chosen in the temperature range ur 1100 - ensuring VOCT cooling as rate of 47,8, ° C / sec, «t (d) 2 where m - module engaging mm; d is the pitch diameter of the workpiece at a temperature of 1100 ° C, mm: V is linear The speed of the workpiece at the pitch diameter dt is the linear expansion coefficient (shrinkage) of the metal of the workpiece.

Claims (1)

Claim A method of knurling gears, in which sequential processing is carried out, including heating the workpiece, a rough knurling of the ring gear with a tooth profile height exceeding the required,; and its subsequent finishing by shrinkage, while finishing is carried out in a half-hot thermal mode using the temperature of the end of rough knurling, which is due to the fact that, in order to increase the productivity of machining gears with internal gearing, rough knurling and final processing of the gear ^{35 of the} crown is carried out in one pass, while the semi-hot thermal regime is selected in the temperature range 1100 - 500 ° C with a cooling speed Voct equal to 40 Voct = - / 47.8, ° C / s, a _t (d) ² where m is the engagement modulus, mm; 45 d ¹ - the diameter of the pitch circle of the workpiece at a temperature of 1100 ° C, mm: V is the linear velocity of the packing on the diameter of the pitch circle d ¹ ; at is the coefficient of linear expansion (shrinkage) of the workpiece metal. Fig2 Editor I. Shulla Compiled by J. Sokolov Tehred M. Morgenthal Corrector A · Osaulenko Order 292 Circulation Subscription VNIIIPI State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035, Moscow. Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.