Previously, our industry produced universal dividing heads UDG-N-135 and UDG-N-160 with center heights H=135 and H=160 mm. According to the new standard (GOST 8615-69), the largest diameter of the workpiece D is taken as the main size of the dividing heads. According to the standard, a series of six standard sizes of dividing heads D: 160; 200; 250; 320; 400 and 500 mm. Universal heads are used to complete domestic and foreign milling machines.
Each size of the machine (on the width of the table) must correspond to a certain size of the dividing head. So, for console milling machines No. 2 (with a table width of 320 mm), a dividing head with the largest diameter of the workpiece being processed D = 250 mm is recommended, and for milling machines No. 3 (with a table width of 400 mm) - a dividing head UDG-I-320 etc. In fig. 196 shows a universal dividing head. A body 10 is installed on a cast-iron base 20 with tightening arches 9. By loosening the nuts, it is possible to turn the body by an angle determined by the scale and vernier 12. On the base plane of the base of the dividing head there are two crackers parallel to the spindle, designed to install the head into the grooves of the milling machine table. A spindle with a through hole is located in the body. Its ends are bored into a Morse taper. On one of them the center is set 21., on the other - a mandrel for differential division. At the front end of the spindle there is a thread and a centering belt 7, necessary for fastening a three-jaw self-centering or driving chuck. On the shoulder of the spindle there is a limb 8 of direct division with 24 holes. In the middle part of the spindle there is a worm wheel with a circular recess at the end, into which the end of the clamp 11 enters. It receives rotation from the worm located in the eccentric bushing. By turning the sleeve with the handle, the worm can be engaged or disengaged. The dividing disk sits on a shaft mounted in plain bearings installed in the cover 19. The cover is fixed on the body 10 by a centering bore and fixed to the base. A sliding sector 18, consisting of rulers 14 and a clamping screw 13, is pressed against the dividing disk by means of a spring, with the help of which the rulers are set at the required angle. The spring washer prevents spontaneous rotation of the sector.
The shaft 16 of the mechanical drive from the machine is mounted in plain bearings and is located in the sleeve 15 fixed on the cover 19. At the end of the shaft there is a bevel gear that is in constant engagement with the bevel gear sitting on the shaft of the dividing disk. The dividing disk is fixed in the required position by the stopper 17. The center of the tailstock can be moved in the horizontal and vertical directions. In the base 24 there is a body 2, which is connected with the rail by a pin. By rotating the head of the gear shaft, you can move the body up and rotate about the axis of the pin. In the required position, the tailstock is attached to the machine table with bolts and nuts. Pinol 3
It moves with the semi-center 4 during the rotation of the handwheel 1, mounted on a screw.
On the support plane of the base there are two guide crackers, aligned relative to the axis of the quill, which ensure that the centers of the dividing head and the tailstock coincide when they are installed on the machine table. The steady rest serves as an additional support when processing non-rigid workpieces.
In the body 23 of the steady rest there is a screw that moves with the help of a nut 5 and has a prismatic head 6, which is fastened with a locking screw 22. The semi-universal dividing head is similar in design to the universal dividing head.
In table. 20 shows a brief technical description of dividing heads.
direct division. With direct division, the worm of the head must be disengaged from the worm wheel. The rotation of the workpiece is carried out by rotating the spindle. The angle of rotation is measured according to the graduated one. on a 360° disc with a division value of 1°. The vernier allows you to read the spindle angle with an accuracy of 5". The spindle angle when divided into z parts is determined by the formula 
where a - spindle rotation angle, deg;
z is the given number of divisions.
At each turn of the head spindle, to the reading corresponding to the position of the spindle before the turn, the value of os found by formula (23) should be added. For some heads, the dividing disk (frontal) for direct division is not graduated, but has three dividing circles with 24, 30 and 36 holes. Three rows of holes in the dividing disc 
Allows direct division into 2, 3, 4, 5, b, 8, 10, 12, 15, 18, 24, 30 and 36 parts. The number of gaps between the holes of the selected dividing circle on the frontal dividing disk, skipped when the head spindle is turned, is determined by the formula
where a is the number of holes of the selected circle on the frontal disk;
z is the given number of divisions.
Simple division. On fig. 197 shows a kinematic diagram of universal dividing heads (D-250 and D-320) for simple division. In this case, the worm 8 must be engaged with the worm wheel 10. The rotation of the spindle 9 (division) is performed by rotating the handle 2 with the latch 3 relative to the fixed fixed side dividing disk 1, which has concentric circles with holes. When setting up, latch 3 is set against the selected circle on the dividing disk. The rotation of the handle is transmitted through spur gears 7 with a gear ratio i == 1 and a worm gear pair with gear
ratio i = 1/40 per spindle. The spindle must then turn 1/z of a turn to divide the circle into z equal parts. Therefore, the equation of the kinematic chain of spindle movement will be
Where do we get that 
Let it be required to divide the workpiece into z parts (for example, when milling a gear with z teeth). This means that after milling each cavity, it is required to turn the spindle together with the workpiece by 1/Z of a turn, therefore, the handle 2 - by 40/z of turns. If z<40, то дробь 40/z>1 and can be written in the form 
where A is the number of whole (full) turns of the handle;
a and b are the numerator and denominator of a regular unreduced fraction;
m is a common factor for a and b, chosen so that mb is the number of holes on some circumference of the dividing disk. Then it will express the number of divisions (steps) on the circumference of the limb (or gaps between adjacent holes of the selected circle mb), by which the handle 2 must be turned, in addition to A whole revolutions. The reading of the required rotation of the workpiece being processed is made on a fixed dividing disk, one of the holes of which includes a spring-loaded pin of the latch. This disc is double sided.
With a simple division, the sleeve 4, the bevel wheels 5 and the shaft 6 do not participate in the division (Fig. 197).
For the convenience of counting the gaps between the holes (or counting the holes) of the dividing circle, a sliding sector (Fig. 198) is used, which consists of two legs 1 and 3. These legs can rotate one relative to the other. 
The legs of the sector are set so that there is a number of gaps between them. To set the sector to the working position, it is necessary to insert the latch rod into one of the holes of the selected dividing circle, for example, into hole A. Having released the screw 2 that fastens the legs 1 and 3 of the sector, bring the leg 1 to the latch rod. After counting the number of gaps of the circle, leg 3 of the latch is brought to the last hole B and the sector is fixed with screw 2. It should be remembered that if the count is made according to the number of holes in the circle, starting from the one that includes the pin of the latch, then the number of holes should be one more than the number gaps between the holes and in fig. 198 counted five intervals of the circle, limited by six holes. After milling the surface of the workpiece with this position of the latch, turn the handle of the head clockwise, insert the latch rod into hole B and turn the sector in the same direction until it touches leg 3. The sector in the new position is shown in fig. 198 dotted. The handle must always be rotated clockwise to avoid the effect of backlash in the transmission from the handle shaft to the head spindle. When the handle latch is opposite the last skipped gap between the holes of the circle, the latch handle must be released and carefully, tapping it with your hand, bring it to the desired position. At this point, the latch under the action of the spring will enter the hole in the circle.
If the handle was accidentally turned further than required, then it is necessary to turn it counterclockwise a little further than the missed hole, and then turn it again clockwise by careful tapping to the desired position.
Example. Pick up a circle of holes on the dividing disk and adjust the opening angle of the legs of the sector, if z = 35, N = 40.
Solution.
1. By formula (25). 
When processing teeth, splines, grooves, cutting helical grooves and other operations on milling machines, dividing heads are often used. Dividing heads, as devices, are used on console universal milling and universal machines. There are simple and universal dividing heads.
Simple dividing heads are used to directly divide the circle of rotation of the workpiece. The dividing disk for such heads is fixed on the head spindle and has divisions in the form of slots or holes (in the amount of 12, 24 and 30) for the latch latch. Discs with 12 holes allow you to divide one turn of the workpiece into 2, 3, 4, 6, 12 parts, with 24 holes - into 2, 3, 4, 6, 8, 12, 24 parts, and with 30 holes - into 2 , 3, 5, 6, 15, 30 parts. Specially made dividing disks of the head can be used for other division numbers, including division into unequal parts.
Universal dividing heads are used to set the workpiece at the required angle relative to the machine table, rotate it around its axis at certain angles, communicate the workpiece with continuous rotation when milling helical grooves.
In the domestic industry, on console universal milling machines, universal dividing heads of the UDG type are used (Fig. 1, a). Figure 1, 6 shows accessories for dividing heads of the UDG type.
On universal tool milling machines, dividing heads are used that are structurally different from dividing heads of the UDG type (they are equipped with a trunk for installing the rear center and, in addition, have some difference in the kinematic scheme). Both types of heads are configured identically.
As an example, in fig. 1, a shows a diagram of processing by milling a workpiece using a universal dividing head. The workpiece / is installed on the reference in the centers of the spindle 6 of the head 2. and the tailstock 8. The modular disk cutter 7 receives rotation from the spindle of the milling machine, and the machine table receives the working longitudinal feed. After each periodic rotation of the gear blank, the cavity between adjacent teeth is machined. After processing the cavity, the table rapidly moves to its original position.
Rice. 1. Universal dividing head UDG: a - scheme for installing the workpiece in the dividing head (1 - workpiece; 2 - head; 3 - handle; 4 - disk; 5 - hole; 6 - spindle; 7 - cutter; 8 - headstock); b - accessories for the dividing head (1 - spindle roller; 2 - front center with a leash; 3 - jack; 4 - clamp; 5 - rigid center mandrel: 6 - cantilever mandrel; 7 - rotary plate). The cycle of movements is repeated until all the teeth of the wheel are completely processed. To install and fix the workpiece in the working position with the help of a dividing head, rotate its spindle 6 with the handle 3 along the dividing disk 4 with a dial. When the axis of the handle 3 enters the corresponding hole of the dividing disk, the spring device of the head fixes the handle 3. On the disk, 11 circles are concentrically located on both sides with the numbers of holes 25, 28, 30, 34, 37, 38, 39, 41, 42 , 43, 44, ^7, 49, 51, 53, 54, 57, 58, 59, 62, 66. The kinematic diagrams of the universal dividing heads are shown in Fig. 2. In the universal limb dividing heads, the rotation of the handle 1 (Fig. 2, a-c) relative to limb 2 is transmitted through gears Zs, Z6 and worm gear Z7, Zs to the spindle. The heads are adjusted for direct, simple and differential division.
Rice. 2. Kinematic schemes of universal dividing heads: a, b, c - limbic; g - limbless; 1 - handle; 2 - dividing limb; 3 - fixed disk. The direct division method is used when dividing a circle into 2, 3, 4, 5, 6, 8, 10, 12, 15, 18, 24, 30 and 36 parts. With direct division, the reading of the angle of rotation is carried out on a graduated 360 "disk with a division value V. Nonius allows you to perform this reading with an accuracy of 5", The angle a, deg, of rotation of the spindle when divided into z parts is determined by the formula
a=3600/z
where z is the given number of divisions.
At each turn of the head spindle, to the reference corresponding to the position of the spindle before turning, add a value equal to the value of the angle a found by formula (5.1). The universal dividing head (its diagram is shown in Fig. 2, a) provides a simple division into z equal parts, which is performed by rotating the handle relative to the fixed disk according to the following kinematic chain:
1/z=pr(z5/z6)(z7/z8)
Where (z5/z6)(z7/z8) = 1/N; np is the number of turns of the handle; N- characteristic of the head (usually N=40).
Then
1/z=pp(1/N)
Where pp=N/z=A/B
Here A is the number of holes by which the handle must be turned, and B is the number of holes on one of the circles of the dividing disk. Sector 5 (see Fig. 5.12, a) is moved apart by an angle corresponding to the number A of the holes, and the rulers are fastened. If the left ruler of the sliding sector 5 rests against the latch of the handle, then the right one is aligned with the hole into which the latch must be inserted at the next turn, after which the right ruler rests against the latch. For example, if you need to set up a dividing head for milling the teeth of a cylindrical gear with Z= 100, with the characteristic of the head N=40, then we get
pr - N / z \u003d A / B \u003d 40/100 \u003d 4/10 \u003d 2/5 \u003d 12/30, i.e. A \u003d 12 and B \u003d 30.
Therefore, the circumference of the dividing disk with the number of holes B = 30 is used, and the sliding sector is adjusted to the number of holes A = 12. In cases where it is impossible to select a dividing disk with the desired number of holes, differential division is used. If there is no required number of holes on the disk for the number z, the number zf (actual) is taken close to s, for which there is an appropriate number of holes. be positive (the additional rotation of the spindle is directed in the same direction as the main one) or negative (the additional rotation is opposite). Such a correction is carried out by an additional rotation of the dividing disk relative to the handle, i.e. if, with a simple division, the handle is rotated relative to the fixed disk, then with differential division, the handle is rotated relative to the slowly rotating disk in the same (or opposite) direction. From the spindle of the head, rotation is transmitted to the disk through interchangeable wheels a-b, c-d (see Fig. 2, b), a conical pair Z9 and Z10 and gears Z3 and Z4.
The amount of additional turn of the handle is equal to:
prl \u003d N (1 / z-1 / zph) \u003d 1 / z (a / b (c / d) (z9 / z10) (z3 / z4)
We accept (z9/z10)(z3/z6) = С (usually С= I).
Then (a/b)(c/d)=N/C((zph-z)/zph))
Suppose you want to set up a dividing head for milling the teeth of a cylindrical gear with r = 99. It is known that N-40 and C = 1. The number of turns of the handle for simple division Pf-40/99, Considering that the dividing disk does not have a circle with the number of holes 99, we take t \u003d 100 and the number of turns of the handle pf-40/100 \u003d 2/5 \u003d 12/30, i.e. We take a disk with the number of holes on the circle B = 30 and turn the handle into 12 holes when dividing (A = 12). The gear ratio of replaceable wheels is determined by the equation
and \u003d (a / b) (c / d) \u003d N / C \u003d (zph-z) / z) \u003d (40/1) ((100 - 99) / 100) \u003d 40/30 \u003d (60/30) x (25/125).
Limbless dividing heads (see Fig. 2) do not have dividing discs. The handle is turned one turn and fixed on a fixed disk 3. With a simple division into equal parts, the kinematic chain looks like:
Considering that z3/z4=N,
We get (а2/b2)(c2/d2)=N/z
1.1. The universal dividing head of the UDG type is designed to perform work on processing a part associated with turning a part by a given value when working on milling, gear-cutting, slotting, boring, planing and drilling machines, as well as marking and other works.
1.2. Dividing heads are important accessories for console milling machines, especially universal ones, and are used when it is necessary to mill faces, grooves, splines, wheel teeth and tools located at a certain angle relative to each other. They can be used for simple and differential division.
1.3. With a dividing head, it is possible to produce in centers, in a chuck or on a spindle mandrel and carry out the following specific operations:
- simple division of circles;
- direct division of circles;
- differential division of circles without interval;
- spiral milling;
- gear milling;
- spiral milling. hypoid grooves;
- setting the axis of the workpiece at the required angle relative to the machine table.
Main characteristics.
The main characteristic of the dividing head N is the reciprocal of the gear ratio of the worm pair. Technical characteristics of universal dividing heads of the UDG type are presented in Table 1.
Table 1 - Technical characteristics of universal dividing heads
| Characteristic | UDG-160 | UDG-200 | UDG-250 | UDG-320 |
| The largest diameter of the workpiece, mm | 160 | 200 | 250 | 320 |
| Center height, mm | 80 | 100 | 125 | 160 |
| Mounting flange diameter (machine spindle size) | 36,541 | 41,275 | 53,975 | 53,975 |
| Key width, mm | 14 | 14 | 18 | 18 |
| Spindle angle from horizontal position | ||||
| - down from the line of centers, hail | 90 | 95 | 95 | 95 |
| - up from the line of centers, hail | 6 | 5 | 5 | 5 |
| Worm gear ratio | 1:40 | 1:40 | 1:40 | 1:40 |
| Mounting in the spindle hole (Morse taper) | 3 | 3 | 4 | 4 |
| Nonius division price | 10” | 10” | 10” | 10” |
| Replaceable gear module, mm | 1,5 | 1,5 | 1,5 | 1,5 |
| Weight, kg (net) | 36 | 67 | 119 | 125 |
| Weight, kg (gross) | 42 | 79 | 132 | 140 |
| Dimensions | 544×405×222 | 616×465×265 | 536×460×310 | 710×505×342 | 80 | 100 | 130 | 130 |
Accuracy characteristics.
The universal dividing head rotates the workpiece while maintaining the technological bases of the workpiece with the following accuracy characteristics presented in Table 2.
Table 2 - Accuracy characteristics of universal dividing heads
| No. pp | Parameter | UDG160 | UDG200 | UDG250 | UDG320 | |
| 1 | ||||||
| a) at the base of the cone | 0.010 | 0.010 | 0.010 | 0.010 | ||
| b) at a distance of 300mm from the front of the spindle | 0,015 | 0.020 | 0.020 | 0.020 | ||
| 2 |  |
0.010 | 0.010 | 0.010 | 0.010 | |
| 3 |  |
0.010 | 0.010 | 0.010 | 0.010 | |
| Periodic axial sliding of the spindle | 0.010 | 0.010 | 0.010 | 0.010 | ||
| Spindle nose runout | 0.020 | 0.020 | 0.020 | 0.020 | ||
| 4 |  |
0,02/300 | 0,02/300 | 0,02/300 | 0,02/300 | |
| 5 | Parallelism of the pin to the spindle axis |  |
0.010 | 0.015 | 0.015 | 0.015 |
| 0.010 | 0.015 | 0.015 | 0.015 | |||
| Deviation of the spindle axis from the T-slot | 0.010 | 0.015 | 0.015 | 0.015 | ||
| 6 |  |
60″ | ±45″ | ±45″ | ±45″ | |
| Accumulated error on any ¼ spindle circumference | 70″ | one' | one' | one' |
Operating procedure.
4.1. Before starting work, read the set of technical documentation.
4.2. Wipe the set of equipment, remove the grease with a rag soaked in gasoline, wipe dry with a cloth.
4.3. Mount the dividing head and related accessories on the machine. Prepare the machine and equipment for work. Select a layout method.
4.4. The control elements of the dividing head and its design are shown in Figure 1 and Figure 2.
1 - handle for turning off the worm gear;
2 - graduated disk;
3 - handle for blocking the spindle;
4 - fixing pin;
5 - dividing plate;
6 - blocking pin for dividing plate;
7 - nut for adjusting the backlash between the worm and the worm wheel;
8 - toothed shaft.
The dividing head can operate in several modes:
Direct layout (division)
When doing straight scribing, first release the worm gear and gear wheel and then use the graduated disc on the front of the dividing head spindle as well as the scribe lines on the body.
After marking with a dividing head, they proceed to milling, and then the spindle should be blocked using the handle on the spindle.
Simple markup (division)
Simple marking (division) using a dividing head on the surface of the workpiece is most often performed.
The number of turns of the dividing head is defined as the quotient of the division, and is calculated as follows:
n = 40 (number of teeth on the gear) / Z (number of divisions on the workpiece)
It should be noted that the result of division is not an integer, but a fractional one. The denominator is the number of holes in the index plate ring. If the denominator does not correspond to the number of holes in the dividing plate, then division is possible. The disc moves to the next position and is fixed with a pin.
If the denominator of the fraction does not match the number of holes in the dividing plate, simple division cannot be used, for this differential division is used.
differential division
If necessary, any number of equal divisions can be obtained using the differential division method. When performing a differential division, first disengage the divider plate locking rod from the divider plate. Insert the arbor into the tapered hole at the rear end of the spindle and then install the change gear into the arbor. With this mandrel, the moment is transmitted through a replaceable gear train. Then turning the dividing head handle to turn the spindle. The spindle, in turn, drives an interchangeable gear train.
With differential division, the calculation of a gear change is as follows:
where I is the gear ratio of the replaceable gear
X - desired value
Z is the number of teeth of the replaceable gear train
A, B, C, D - number of teeth of the replaceable gear train
The choice of the required value of X depends on the number of divisions Z of the workpiece. To determine this value, the number of holes on the dividing plate is first selected, or for convenience, the fraction is reduced to any of its forms, the equivalent value of which corresponds to the number of holes in the dividing plate. For this case, the value of X is sometimes either greater or less than the number of divisions Z of the workpiece, but this value should not differ much, and should be as close as possible to the value of Z.
If X is less than Z, then the result calculated by the formula is negative. In this case, the locking pin must be turned in the opposite direction of the dividing plate.
If X is greater than Z, then the result calculated according to the above formula is positive. In this case, the direction of movement of the locking pin must correspond to the direction of the dividing plate.
The counting of the number of turns of the hairpin is the same as in the case of simple division, but for differential division the actual value of Z should not be taken and the valid value of X should be taken as a substitute. The calculation is carried out according to the formula given below:
Change gear as shown in figure 3.
Milling spiral grooves.
(The dividing head UDG-160 must be equipped with a change gear mount.)
When milling spiral grooves, the locking pin must be placed in the hole in the index plate and the index plate must be loose.
To mill a regular spiral groove, the milling machine table should be set at an effective angle before the work is done, and its value can be calculated by the following formula.
where Ψ is the angle of rotation;
D is the diameter of the workpiece;
T is the pitch of the spiral groove;
The gear ratio can be expressed
where i is the modified gear ratio;
t is the milling step;
T is the groove width;
a,b,c,d - the number of teeth in the mechanism in the gear train.
To mill a left-handed helix, an intermediate gear link must be added, so that replacing components a and d will change direction. For milling a right-handed helix, the replacement of components a and d must be done so that the direction does not change.
Milling a hypoid spur gear
The operation of hypoid spur gear milling is similar to helical grooving, with a difference in the expression of the gear data in the formula.
The calculation of the change in the gear ratio of the gear for milling hypoid cylindrical teeth is carried out according to the formula
where M is the standard tooth module;
β is the angle of inclination of the tooth.
Dividing head assembly and adjustment.
The accuracy of the work performed when using the product and the service life of the universal dividing head mainly depend on the correct installation.
Shocks are unacceptable, both during transportation and during operation.
The installation dimensions of the dividing heads are shown below.
For UDG-160
For UDG-200, UDG-250, UDG-320
Fig.4 Mounting dimensions of dividing heads.
Table 3 shows the connecting dimensions of universal dividing heads (except for UDG-160), indicated by letters in Figure 4
| dividing head | A | B | C | D | E | F | G | H | L | M | N | O | P |
| UDG-200 | 162 | 14 | 102 | 87 | 186 | 95 | 116 | 100 | 93 | 54.7 | 30 | 100 | 100 |
| UDG-250 | 209 | 18 | 116 | 98 | 224 | 117 | 120 | 125 | 103 | 68.5 | 34.5 | 100 | 125 |
| UDG-320 | 209 | 18 | 116 | 98 | 259 | 152 | 120 | 160 | 103 | 68.5 | 34.5 | 100 | 160 |
Setting the dividing head.
Fig.5. Setting the dividing head to simple division
A simple division on a universal dividing head differs from a direct one in that the transfer between the workpiece and the dividing disk is carried out through a worm pair, i.e. a worm with leads and a worm wheel with z ChK teeth. The worm wheel sits on the spindle 1 heads, and the worm - on the shaft 2 with handle 4, having two movements - D and L. Movement D allows you to connect the handle with a dividing limb (disk) 5 , on both ends of which a certain number of holes (divisions) is evenly located along a number of concentric circles.
For example, one side of the disc has 16, 17, 19, 21, 23, 29, 30, and 31 holes, while the other side has 33, 37, 39, 41, 43, 47, 49, and 54 holes. In dividing heads, the worm on shaft 2 is always single-threaded, i.e. k- 1a z ChK= 40, 80 or 120. Ratio N = z ChK /k called the characteristic of the dividing head. Shaft 3 used in other cases. One turn of the handle will rotate the workpiece by k/z CHK= 1/N. When cutting a gear wheel, you need to do etc handle revolutions, i.e. n p = k/N = 1/z or etc= N/z. Head characteristic N= const, a z= var, so usually n p is not an integer. Yes, at N = 40, z= 15 we get n p = 40/15 turns. Adjusting the handle by moving L on a circle with 30 divisions, we get that to rotate the workpiece by 10/15 part of the circle, it is required to make two full turns and another 20/30 part, i.e., 20 divisions (holes) of a circle with 30 holes. The head allows, with a simple division, to rotate the workpiece by many values 1 /z, however, not all required in production.
Fig.6. Setting the dividing head for differential division
Differential adjustment of the head is carried out with the stopper off 6 , limiting the mobility of the limb 5. Here, the rotation of the handle 4 also transmitted (via worm gear) to the spindle 1 , but at the same time the limb 5 of the dividing head will also rotate.
Setting the head consists in determining the number of turns of the handle (as with a simple division) and the wear of the teeth of the guitar wheels i D. The number of revolutions of the handle is found from a known ratio, replacing the “uncomfortable” number of teeth close to it with an approximate one - z np . In the example above it was N= 40; let's say z = 53. It is clear that it is impossible to make a 40/53 turn using the available disks. Accept z nр = fifty; then n p \u003d N / z pr \u003d 40/50. If you use a circle with 30 holes, then the handle will need to be turned 40/50 = 24/30 part of the circle, i.e. 24 divisions (holes).
Therefore, with each division reception on the spindle, an error will occur
d w = (1 / z -1 / z pr),
and on the handle
d p \u003d d w z chk / k.
It is possible to compensate for this error by additionally turning the limb not held by the stopper. This compensation must occur in a period of rotation of 1/z part of the circle, therefore,
1/z*i g *i=(1/z-1/z pr)N,
then i g \u003d N (z pr -z) / z pr
In our example i g=40(50-53)/50=-120/50.
According to this fraction, the teeth of the wheels are selected z a , z a1 , z b , z b1 , and the sign shows the direction of the additional turn of the limb - in the opposite direction from the main n p , reducing the absolute rotation of the workpiece.
Cutting helical grooves, helical gears, etc. in increments R possible with a universal dividing head. The setting here is to get the rotation of the workpieces consistent with the longitudinal feed. For this purpose, the rotation of the lead screw of the longitudinal feed of the milling machine table is used to rotate the spindle 1 dividing head by connecting the roller 3 a set of interchangeable wheels having a ratio of the number of teeth i b =z c z d1 /(z c1 z d) with a lead screw having a pitch R prod longitudinal feed. For one revolution of the workpiece, the table must move by an amount
1 vol. zag z chk ii b \u003d P / P prod about. screw;
i in \u003d P / (P prod N) \u003d z c z d1 / (z c1 z d),
where P is the pitch of the helix;
R prod - lead screw pitch.
Storage rules.
9.1. Store the set of equipment in its original packaging in a dry, heated room at an air temperature of +5 to +40˚С and refer
flax humidity no more than 75%.
9.2. When storing the product for a long time, in order to avoid corrosion, in addition to lubrication with oil, it must be wrapped in paper with water-repellent impregnation.
9.3. The air in the room should not contain admixtures of aggressive vapors and gases.
Indication of security measures.
In order to avoid injuries, it is necessary to adhere to the rules of safe work, observe safety precautions when working with machines. The dividing head must be securely mounted on the machine in accordance with the requirements of GOST 12.2.009-99. Do not take measurements while the machine is moving, when the cutting tool is moving and when the part being measured is rotating.
Equipment.
- Universal dividing head — 1 pc.
- Tailstock - 1 unit.
- Gear attachment device (except for UDG-160) - 1 unit.
- Gear (except UDG-160) - 1 unit.
- Caliper - 1 unit.
- Turning center - 1 unit.
- Bracket - 1 pc.
- Dividing plate - 1 unit.
- Three-jaw self-centering chuck - 1 unit.
- Technical documentation - 1 set.
Information about conservation.
10.1. A set of equipment for a universal dividing head of the UDG type is subjected to conservation in accordance with the requirements of GOST 9014-76. The name and brand of the preservative is conservation oil K-17.
10.2. The shelf life of the kit without re-preservation is 2 years, provided that it is stored under conditions in accordance with GOST 15150-69.
Warranty obligations.
Warranty period of operation of the product is 1 year from the date of sale (receipt by the buyer) of the device, provided that the consumer observes the rules for storing and operating the device.
Download The technical data sheet is available free of charge at the link below.
(UDG) are a type of devices used mainly in small-scale, single-piece production. Through the use of such universal machine tools, it is possible to significantly increase productivity and facilitate working conditions. In addition, their use increases the safety of work, expands the technological capabilities of production equipment.
In the design of the dividing heads are horizontal machine tools. They are equipped with milling, jig boring machines (semi-automatic). With their help, periodic rotations of the workpieces to be processed at specified angles (divisions) are carried out. The workpiece itself is installed in the chuck. The use of UDG guarantees the receipt of specified geometric shapes, the exact dimensions of the workpieces.
The use of such devices is especially effective in technologies for cutting teeth of gear wheels, milling cavities between teeth, in the processing of polyhedrons, in the production of many types of tools (drills, countersinks, special tools). When cutting spiral grooves with the help of such dividing heads, continuous rotation and simultaneous axial feed of workpieces is carried out.
In mechanical engineering (metalworking), various types of universal dividing heads (UDG) are used. The most common limb dividing heads. This type of equipment can be adjusted for differential, simple division, for milling helical parts. These technological capabilities are in most cases sufficient for high-precision processing of complex surfaces.
Division Methods
Most often, by means of universal dividing heads, two methods of dividing are realized: simple and differential. With a simple division, a count is made on a fixed dividing disk. The rotation of the part is controlled by a handle connected via a worm gear to the head spindle.
With differential division, the spindle is rotated both by a handle (similar to a simple one), and due to the forced rotation of the dividing disk itself from the spindle (through a system of gears).
Table 1. Adjustment of dividing heads according to the simple division method
Table 2. Adjustment of dividing heads for differential division
Benefits of using UDG
The use of universal dividing heads allows you to get a number of significant advantages. The main ones are the following:
the range of technological operations of the milling machine is significantly expanded;
the ability to work with workpieces of different sizes;
the possibility of processing surfaces in any position relative to the vertical.
Universal dividing heads are easy to install and operate. The cost of an additional device is available. Therefore, it can be used in single production, including in private applications.
Selection of universal dividing heads
When choosing a dividing head, the UGD is first determined with its type. The most commonly used dividing heads are universal. They, in turn, differ from each other by the value of the largest diameters of the workpieces being processed. For example, the following types of dividing heads are produced by the domestic industry: from UDG-D-160 to UDG-D-400 (for diameters 160, 200, 250, 320, 400 mm).
All types of devices are unified, they differ mainly in the height of the centers. For universal dividing heads, special tables for calculating simple / differential division have been compiled. When choosing a fixture, its working diameter is selected according to the dimensions of the parts to be fixed. That is, if workpieces with small diameters are processed, it is better to install an UDG of the same size.
The equipment used for metal processing has a lot of features that should be considered in order to quickly obtain high-quality parts. For a milling machine, a fairly large amount of equipment is used, which is necessary to obtain certain parts. The dividing head is a tool used in the operation of a milling machine.
Design features
The dividing head that is created for the milling machine is a horizontal type machine tool that can also be used on jig boring machines. The purpose of this device is to periodically rotate the workpiece. In this regard, the following points can be highlighted:
- rotation can be performed at an equal or unequal angle. This indicator is set with high accuracy;
- a dividing head is used for cutting teeth, cavities between teeth, milling polyhedrons, grooves and other elements;
- you can use this element in order to significantly increase the capabilities of the milling machine. Without a special tool, it is impossible to carry out division with high accuracy;
- fastening of blanks is carried out in the cartridge. If the length of the workpiece is large enough, then fastening is carried out using the tailstock. Consideration should be given to the need for correct positioning of the workpiece with a low probability of deviation from the initial base.
This device has been in use for the past few years.
Classification of the equipment used to set the angle
Division can occur using the following types of construction:
- universal versions;
- simplified designs;
- optical type, which is used to perform particularly precise work.
The above classification should be considered when considering designs that expand the capabilities of the milling machine. Often, the division goes through this particular device; universal versions are used quite often.
Division Methods
Division using a milling machine can be carried out by several methods, among which we note:
- Direct division is carried out without the use of an intermediate mechanism. For this, a device with a simple optical division is used.
- Simple division is used quite often, in which a fixed disk is used. This cutting method is carried out using UDG, which makes the scope of application extensive.
- Combined division is also carried out using a dividing head.
- The differential method is also carried out on universal dividing heads, which have an additional set of interchangeable gears.
- The continuous method is implemented by optical and universal heads, which have a kinematic connection between the spindle head and the longitudinal feed screw of the milling machine.
These methods relate to a milling machine on which the tooling in question can be installed.
Universal Head Marking
To determine the main parameters of the device in question, its designation is carried out according to the established parameters. An example is the model UDG-40-D250. The decoding of this version is as follows:
- UDG - designation of the type of device, in this case, a universal dividing head.
- The next number in the marking indicates the gear ratio. The calculation indicates that the number 40 determines 1 revolution of the spindle for 40 revolutions of the handle.
- The designation D250 indicates the largest diameter of the workpiece being processed.
The above information should be taken into account when considering the EDC. There is a certain table by which you can select the most suitable model.
Optical head marking
When using a milling machine, optical dividing heads can also be installed. There is a certain formula that allows you to determine the degree of accuracy of the equipment in question. A popular model can be called ODG-5. The decryption in this case is as follows:
- ODG is an abbreviation for the name of the device, which stands for optical dividing head.
- 5 - d.c. indicator, which is indicated in seconds. The calculation of this indicator is carried out during the production of the considered tooling.
In the production of this tooling, the need for accurate dimensional maintenance is taken into account, since even a slight deviation can lead to large discrepancies in dimensions. The calculation is carried out using modern methods.
Sequence of setting and application
The transitions performed depend on the type of fixture and its characteristics, which are set depending on the value of the scale division. In particular, for nodes of the seventh / eighth degree of accuracy, the normative data of GOST 1.758 are used, and for nodes of the ninth degree of accuracy - GOST 1.643.
The main setting of the head is to determine the size of the sector of the dividing circle. The initial data for the calculation are the diameter of the circle and the number of sectors into which it needs to be divided. The setting takes place in the following sequence:
- convert 360° of the full diameter of the circle into the required number of divisions on its sectors;
- determine the sine of the angle resulting from the calculation;
- turn the disk of the device to a given angle;
- clamp the body of the assembly with a handle or a clamping mechanism and install a working tool.
The formula for calculating the required dividing angle is usually given in the dividing head manufacturer's instructions. Next, the part to be milled is fixed on the mandrel of the machine, and, by longitudinally feeding the table, the required operation is performed. The feed step depends on the type of processing: for example, for tooth shaping, it is equal to the distance between the cavities of adjacent teeth. In order to increase productivity, after each cycle there is an accelerated return of the table with the workpiece to its original position. Fixation along the hole selected in the measuring disc is carried out using springs.
Characteristics
This tooling is quite often used in the production of large batches within a short period of time. In this case, the main structural elements are:
- limbo;
- spindle;
- three jaw chuck.
The spindle allows you to properly fix the workpiece. In addition, a dial is also attached to the spindle, which is used as a disk for setting the angle. It is the limb that is used to divide the workpiece into several parts.
In order for the equipment to work correctly for a long time, you should responsibly set up the equipment. As a rule, it takes quite a long time to complete the work of setting the division indicators.
Download the instruction "Universal dividing heads UDG"
