Tailstock of the dividing head. Setting up the dividing head

Increasing the functionality of production equipment is possible after installing a dividing head. It is necessary for the production of complex parts and workpieces. This component is often included by default. If it is missing, it is necessary to correctly select the optimal model.

Purpose of the dividing head

To form a part of the desired shape, it may need to be offset relative to the axis of the machine. This can be done using a dividing head. It can be either a separate part of the structure or its component.

The component is mounted on the equipment frame. It has various options for fixing the product, which depend on the type of attachment. The position is adjusted using several handles and a dial. The latter has holes that fix the position of the dividing component.

A similar tool may be needed to perform the following processes:

milling grooves on the surface. This does not require great precision. It is important to control the depth and width of the workpiece;
formation of edges on parts. This is true for non-standard nuts, tools, and shanks. The operation requires high precision;
milling splines and grooves. This often requires significant displacements of the workpiece. Therefore, you should choose a dividing disk model with a minimum error rate.

To increase the speed of work, the part should not be constantly dismantled. Changing its position relative to the machine cutter occurs using the tool described above. Particularly difficult is the formation of helical grooves. This operation can only be performed using an accurate model.

Before purchasing a dividing head for a specific type of equipment, you must check its compatibility with the machine. Any independent alteration of the installation part may affect the quality of the product.

Types of dividing head

Considering the specifics of the application, you should familiarize yourself in detail with the types and general classification of dividing heads. They are mandatory for universal milling machines. The configuration of horizontal milling machines is carried out only when it is necessary to perform complex work.

First of all, you need to decide on the types of work performed on the machine. Particular attention is paid to the accuracy of their implementation. The next parameter is the complexity and accuracy of setting up the equipment for operation. Depending on these factors, you can select models with high accuracy and acceptable error rates. In some cases, such a device is made independently.

There is the following classification of milling dividing heads:

simple. A special feature is its simple setup and ease of control. The main component is the spindle, on which the workpiece is attached on one side, and the second is connected to a special disk (limbo). The surface of the latter has holes (from 2 to 24). With their help, the part is shifted relative to the milling axis;
combined. Control occurs using a handle. The greater the number of clicks, the greater the distance between the central axis of the workpiece and cutting tool. Used for the manufacture of complex parts;
universal. They are a complex technological complex, the adjustment of which is carried out both using the switching number of the handle and during the movement of the disk itself. This is done by a system of gears. This type of DG is called differential.

UDG. This device designation is Universal Dividing Head;
40 – gear ratio value. It shows how many turns of the handle the spindle will rotate 360°;
D250 is the maximum permissible size of the workpiece being processed.

UDG class models are most often used to form complex edges and surfaces. They are made to order or are components of universal milling machines.

Rarely encountered optical types are marked ODG-5, where 5 is the price of one division in seconds.

Technical characteristics of UDG

Head
Workpiece diameter, mm	400	320	250	160	125
Worm pair	1 in 40	1 in 40	1 in 40	1 in 40	1 in 40
Diameter of replacement wheels	32 x f9	32 x f9	20 x f9	20 x f9	20 x f9
Spindle diameter, mm	38,2	38,2	26,5	14,9	20,2
Dial division price	15	15	15	15	15
Chuck diameter, mm	200	160	160	100	125
Key width, mm	22	18	18	12	14
Weight, kg	106	101	536,6	25	28

Calculation table of divisions

Division parts	Number of revolutions	Counted holes	Total holes
2	20	—	—
3	13	11	33
4	13	9	39
5	13	13	39
6	19	—	—
7	8	—	—
8	6	22	33
9	6	20	30
10	6	26	39
11	5	35	49
12	5	15	21
13	5	—	—
14	4	24	54
15	4	—	—
16	3	10	30
17	3	3	39
18	2	42	49
19	2	18	21
20	2	22	33
21	2	20	30
22	2	28	39

Self-production

One of the disadvantages of factory models is their high cost. Therefore, to perform simple operations, a homemade structure is made. For practical implementation, certain components will be required.

First of all, you will need a worm gearbox. You can pick it up from used machines or grind it yourself. It is also necessary to use a lathe chuck (optimal diameter 65 mm) and a dial. The latter can be taken from old drawing drawing boards. To limit processing, it is recommended to install a locking screw.

Before you start making parts, you need to configure the divider. To do this, you can take any standard part and carve any shape. After comparing it with a similar one, additional adjustment is performed.

The capabilities of the universal DG are shown in the video:

In Fig. 197, and a universal dividing head is shown. The universal dividing head can serve:
a) to set the axis of the workpiece being processed at the required angle relative to the machine table (horizontally, vertically, obliquely);

b) for periodic rotation of the workpiece around its axis at certain angles (division into equal and unequal parts);
c) for continuous rotation of the workpiece when milling helical grooves (spirals).
All types of universal dividing heads, regardless of their design, have a worm gear with which the head spindle rotates. The front end of the spindle has a conical socket into which the front center can be inserted 2 . In this case, a leash is put on the center 3 , which serves to grip the workpiece being processed. The front end of the spindle is externally threaded onto which a three-jaw chuck can be screwed.
Block 5 dividing head, bearing the spindle, can be rotated around the housing 6 to any angle ranging from 0 to 10° down and from 0 to 100° up on the degree scale on the block and secured in the selected position. In Fig. 197, b shows how the bolts of the rotary block located on the right side of the dividing head are released.
Dividing disks are used to measure the angle of rotation of the head spindle, i.e., for division.
Front dividing disc 1 mounted on the head spindle, its angle of rotation corresponds to the angle of rotation of the spindle. The frontal dividing disk of the universal dividing head can be used for direct division, similar to the dividing heads shown in Fig. 193-196.
The universal dividing head UDG-100 has 24 holes on the front disk and allows division into 2, 3, 4, 6, 8, 12 and 24 parts; The universal dividing head UD G-160 has a frontal disk with three rows of holes (24, 30 and 36 holes) and allows division into 2, 3, 4, 5, .6, 8, 10, 12, 15, 18, 24, 30 and 36 parts.
The universal dividing heads UDG-100, UDG-135 and UDG-160 are manufactured by the Leningrad Dividing Heads Plant. The letters UDG indicate a universal dividing head, and the numbers 100, 135 and 160 indicate the height H of the centers of the head (Fig. 197).
The number of spaces between the holes of the selected dividing circle (this is how we will henceforth abbreviately call the selected row of holes on the dividing disk) missed when turning the head spindle is calculated by the formula:

Where A- the number of holes in the selected circle of the windshield;
z- a given number of divisions.
Example 8. How many spaces between the holes of a 36-hole index wheel should the head spindle be turned when milling six faces?
According to formula (6):

The universal dividing head UDG-135 has a frontal disk graduated by 360°, with a division value of 1°,
For this head, if the central angle α is specified (Fig. 198, a) between the axes of the faces or grooves being milled or checked, then the angle of rotation of the spindle is equal to α.

If the angle β between the planes is given AB And Sun(Fig. 198 b), then the angle of rotation of the head spindle α is determined by the formula α = 180° - β.
If the number of divisions is specified z, per full revolution of the part, then the angle of rotation of the head spindle for each division is determined by the formula:

With each subsequent rotation of the spindle and the count corresponding to the position of the spindle before the rotation, the value α should be added.
Since 1958, dividing heads UDG-100 and UDG-160 have been equipped with a frontal dividing disk, graduated by 360°, similar to the UDG-135 head.
Example 9. It is required to mill 4 edges into the workpiece on the dividing head UDG-135. Determine the position of the spindle when milling each face.
According to formula (7):

If the position of the faces is not related to any surfaces of the workpiece being processed, then when milling the first face, the head spindle should be set to the zero division of the face disk. The counts should be like this;
when milling the 1st face 0°;
when milling the 2nd face 0°+90°=90°;
when milling the 3rd face 90°+90°=180°;
when milling the 4th face 180°+90°=270°.
Check: 270°+90°= 360°.
Side dividing disc 7 (see Fig. 197) has several concentric circles (circles) with holes.
The heads UDG-135 and UDG-160 have one dividing disk, which has eleven circles with blind holes on both sides. On one side of the disk there are circles with 24, 25, 28, 30, 34, 37, 38, 39, 41, 42 and 43 holes, on the other side - 46, 47, 49, 51, 53, 54, 57, 58 , 59, 62 and 66 holes. When working with a head of this type, it is necessary to use one side or the other of the disk, for which it is removed from the roller and secured with the desired side.
The UDG-100 head has two dividing disks with blind holes. The first disk has circles with 24, 25, 28, 30, 34 and 37 holes on one side, and 38, 39, 41, 42 and 43 holes on the other side. The second disk has, respectively: 46, 47, 49, 51, 53 and 54 holes and 57, 58, 59, 62 and 66 holes.
Since 1958, all dividing heads of the Leningrad plant have been equipped with discs with the following rows of holes: 16, 17, 19, 21, 23, 29, 30, 31 on one side and 33, 37, 39, 41, 43, 47, 49 and 54 on the other side.
The dividing disks attached to the dividing heads UDG-100, UDG-135 and UDG-160 allow division into all parts from 2 to 60, from 60 to 120 - only into all even and multiples of 5, over 120 and up to 400 - only for some numbers.
Lever 8 (see Fig. 197) has a locking pin (latch) that fits into the hole of the dividing disk. To install the pin against the required row of holes, the head can be rearranged along the slot and secured in the desired position with a nut 9 .
Keys are screwed to the lower plane of the main plate of the dividing head and fit into the groove of the machine table. These so-called locking blocks establish the position of the dividing head strictly parallel to the table grooves and perpendicular to the machine spindle.
Center 12 (see Fig. 197) the tailstock can be moved longitudinally to secure workpieces. Block 11 , bearing the rear center, allows installation in the vertical direction, as well as at various angles to the horizontal.
The lower plane of the tailstock base also has locking blocks corresponding to the dimensions of the milling machine table groove, similar to the dividing head.
When milling long thin rollers, they are supported with a jack to avoid bending. 10 .
The principle of division using lateral dividing disks is clear from Fig. 199, which schematically shows the spindle of the universal dividing head with a mounted worm wheel and the shaft of the dividing disk with a worm interlocking with the worm wheel. When the handle rotates around the stationary dividing disk, the shaft with the worm rotates, which through the worm wheel rotates the spindle of the dividing head.

Since in domestic universal dividing heads the worm wheel has 40 teeth, and the worm is single-threaded, then for one full revolution of the dividing head spindle the handle (worm) must be given 40 revolutions.
The division method, when the counting is carried out on a stationary dividing disk, and division occurs using a handle connected to the spindle of the dividing head through a worm gear, is called simple division.

Rules for simple division

The number of turns of the handle that must be made for the spindle of the dividing head to turn one revolution is called characteristic dividing head. The heads UDG-135 and UDG-160 have a characteristic of 40. There are heads with a characteristic of 30 or 60. The characteristic of the dividing head is indicated by the letter N.
For a full revolution of the worm wheel and the associated dividing head spindle (Fig. 199 and 200), the handle must be made 40 revolutions; for a half turn, that is, to divide the circle into two parts, you need to make 20 turns; for 1/4 turn, i.e. for dividing into four parts, - 10 turns, etc.

This is expressed as a formula:

Where n- number of turns of the handle;
N- characteristics of the dividing head;
z- the number of divisions of the milled headers.
Substituting instead N the usual characteristic of the dividing head, equal to 40, we get:

Formula (86) is usually used for simple division to determine the number of revolutions of the dividing head handle.
To make it easier to count the required number of holes on the dividing disk, there is a movable sector (see Fig. 199), consisting of two sliding legs and a screw fastening them.

Device for securing workpieces milled in dividing heads

Workpieces milled using dividing heads can be secured in one of the following ways, depending on their design:
a) in the centers of the dividing head and tailstock;
b) on mandrels installed in the centers of the dividing head and tailstock;
c) on mandrels installed in the conical socket of the dividing head spindle;
d) in a three-jaw chuck screwed onto the threaded end of the dividing head spindle.
Long workpieces such as rollers are installed in the centers of the dividing head and tailstock using center sockets available at both ends of the workpiece.
Blanks such as disks and bushings are put on mandrels that are installed in the centers of the index head and tailstock, or on mandrels that are installed in the conical socket of the index head spindle.
In Fig. 201 shows mandrels used to secure workpieces when processing them using a dividing head.
In Fig. 201, and the mandrel is shown, which is a smooth roller, the middle part of which is made with a small cone.

A workpiece mounted on such a mandrel is held there only by friction. The roller has center holes on both sides with which it is installed between the centers of the dividing head and the tailstock. When installing a mandrel with a workpiece put on it, it must be positioned between the centers so that the widened part of the cone faces the dividing head. Otherwise, the cutting force will weaken the fit of the workpiece on the mandrel.
The mandrel shown in Fig. 201, b, has a shoulder 1 , keyway 2 and nut 4 . The workpiece is put on the smooth part of the mandrel, indicated by the number 3 and made according to a sliding fit, and is secured to it with a nut 4 . In case of very high forces encountered during milling, the workpiece can be placed on a key.
The mandrel shown in Fig. 201, in, is used to secure workpieces, when milling which the rear center is not used. This mandrel is inserted with a tapered shank 5 into the conical socket of the dividing head spindle (instead of the center) and tightened with a special screw - tightening 1 (Fig. 202, a).

The workpieces are fixed on the cylindrical part 6 mandrel (Fig. 201, c) in the same way as on the mandrel shown in Fig. 201, b.
In Fig. 202 shows the devices used when installing workpieces in the dividing head.
Center 3 with leash 4(Fig. 202, a) is inserted with a shank 2 into the socket of the dividing head spindle. Leash 4 is shown separately in Fig. 202, b.
Tightening screw 1 for the center or conical mandrel (Fig. 202, a) is inserted into the rear end of the head spindle and the threaded end is screwed into the shank of the center of the mandrel.
Clamp, put on a workpiece or mandrel, is shown in Fig. 202, v. Its curved end 7 fits into the groove of the driver and is secured in it with clamping bolts 5 (Fig. 202, b). Bolt 6 The clamp is fixed to the workpiece.
Often used to secure the workpiece being processed three-jaw chuck(Fig. 202, d), which is screwed onto the front end of the dividing head spindle. For clamping a workpiece with a socket wrench through a small bevel gear 8 rotate a large bevel gear 10 .
Since on back side wheels 10 there is a transverse spiral thread 9 , along which three cams move 11 having a corresponding spiral thread, then when the key is rotated in one direction or another, the cams either converge towards the center of the chuck or diverge from the center, i.e., they clamp or release the workpiece.
The jack (Fig. 203, a) consists of a body 2 , screw 4 with prismatic head, nuts 3 , with the help of which the vertical movement of the screw is carried out, and the locking screw 5 with handle 1 . The locking screw, its end entering the groove of the screw 4 , keeps it from turning when adjusting the height. Figure 203, b shows an example of using a jack.

Optical dividing heads

For precise angular divisions of workpieces during their processing and for checking the accuracy of various kinds of angular parts, optical dividing heads are widely used.
General form and a schematic section of the optical head ODG-60 produced by the Novosibirsk Council National economy shown in Fig. 204, a and b. Glass dial scale 5 with a graduation value of 1°, rigidly mounted on the worm wheel 6 , put on the spindle 9 head rotating in two bearings 8 And 11 . Worm wheel 6 driven by a worm 10 , connected to the handwheel 1 . Worm wheel 6 can be locked in any position with a handle 4 associated with the pressure washer 7 . Worm 10 and worm wheel 6 They serve only to rotate the spindle, and their errors do not affect the accuracy of the head. Rotation angles are measured on a circular scale 5 using a reading microscope 2 , the eyepiece of which is placed outside the head housing. In the field of view of the eyepiece there is a scale divided into 60 parts, with a division value of 1" (Fig. 204, c). These divisions are visible through the eyepiece so large that with some skill you can count quarter minutes from them. The circular scale is illuminated by a light bulb through a prism 3 , placed outside the head housing. Height of centers N = 130 mm.

If the central angle α between the axes of the milled grooves is specified, then the angle of rotation of the head spindle is equal to α.
If the number of divisions per full revolution of the workpiece is specified, then the angle of rotation of the head spindle is determined by formula (7):

where α is the rotation angle of the head spindle in degrees;
z- a given number of divisions.

CONTROL QUESTIONS

1. What devices are used to divide the circle into parts?
2. What is the direct division method? How to divide into 2, 3, 4, 6, 8, 12 parts using the direct division method?
3. What is the simple division method? How to divide into 2, 4, 8, 10, 20 parts using the simple division method?
4. What is the characteristic of the dividing head?
5. Write the formula for simple division.
6. How or in what ways can the workpiece be secured in a dividing device or dividing head? What devices are needed for this?

The equipment used for metal processing has many features that should be taken into account to quickly obtain high-quality parts. Sufficient for milling machine a large number of equipment that is necessary to obtain certain parts. Dividing head is an accessory used when operating a milling machine.

Design Features

The dividing head, which is created for a 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. The following points can be highlighted:

the 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 polyhedra, grooves and other elements;
This element can be used to significantly increase the capabilities of the milling machine. Without a special tool, division cannot be carried out with high accuracy;
The workpieces are fastened in a chuck. If the length of the workpiece is large enough, then fastening is carried out using the tailstock. The need for correct positioning of the workpiece with a low probability of deviation from the initial base should be taken into account.

This device has been in use for the past few years.

Classification of equipment used to set the angle

Division can occur using the following types of construction:

universal execution options;
simplified designs;
optical type, which is used to perform particularly precise work.

The above classification should be taken into account when considering designs that expand the capabilities of a milling machine. Often division is carried out with this device; universal versions are used quite often.

Division methods

Division using a milling machine can be carried out using several methods, among which we note:

Direct division is carried out without the use of an intermediate mechanism. For this purpose, a device with simple optical division is used.
Simple division is used quite often, in which a stationary disk is used. This cutting method is carried out using UDG, which makes the scope of application wide.
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 replaceable 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 the milling machine on which the equipment in question can be installed.

Universal head marking

To determine the main parameters of the device in question, it is designated according to the established parameters. An example is the UDG-40-D250 model. 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 spindle revolution per 40 handle revolutions.
The designation D250 indicates the largest diameter of the workpiece being processed.

The above information should be taken into account when considering the UDG. There is a certain table from 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 looks like this:

ODH is an abbreviation for the name of the device, which stands for optical dividing head.
5 – dc indicator, which is indicated in seconds. The calculation of this indicator is carried out during the production of the equipment in question.

In the production of this equipment, the need to maintain precise dimensions 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 setup and application

The transitions performed depend on the type of device 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 regulatory data of GOST 1.758 are used, and for nodes of the ninth degree of accuracy - GOST 1.643.

The main adjustment of the head is to determine the size of the pitch circle sector. The initial data for the calculation are the diameter of the circle and the number of sectors into which it will need to be divided. The setup occurs 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;
rotate the device disk to a given angle;
clamp the assembly body with a handle or clamping mechanism and install the 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 secured to the machine mandrel, and the required operation is performed by performing a longitudinal feed of the table. The feed pitch 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 the table with the workpiece returns quickly to its original position. Fixation to the hole selected in the measuring disk is performed using springs.

Characteristics

This equipment is quite often used when producing large quantities within a short period of time. The main design elements are:

limbo;
spindle;
three-jaw chuck.

The spindle allows you to properly secure the workpiece. In addition, a dial is also attached to the spindle, 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 over a long period of time, you should be responsible for setting up the equipment. As a rule, it takes quite a lot of time to complete the work of setting division indicators.

Download the instructions “Universal dividing heads UDG”

The developer and manufacturer of dividing heads UDG-160 (UDG-D-160) until 1990 was Leningrad optical-mechanical association LOMO.

Currently, the production and sale of universal dividing heads UDG-160 (UDG-D-160), UDG-200 (UDG-D-200), UDG-250 (UDG-D-250), UDG-320 (UDG-D- 320) carries out Manufacturing company "Delga", which was founded in 1990 on the basis of OJSC LOMO.

Dividing heads. General information

Dividing heads are a device for universal and cantilever milling machines, which significantly expands their technological capabilities. They are used in the manufacture of various tools (mills, reamers, countersinks, taps), normalized machine parts (bolt heads, nut faces, castle nuts), when milling gears, sprockets, cutting grooves and splines at the ends (gear couplings) and other parts .

Dividing heads are used to secure and divide workpieces into equal parts when milling squares, hexagons, cutting gears, sprockets and other similar work, and to rotate workpieces at a given angle. Universal dividing heads also serve to impart rotation of the workpiece when cutting helical grooves on universal milling machines.

Depending on the head design, the workpiece circumference can be divided into equal or unequal parts. When cutting helical grooves, the workpiece is simultaneously subjected to continuous rotational and forward motion, as, for example, when processing chip flutes in drills, cutters, taps, reamers and countersinks.

Dividing heads serve:

to set the axis of the workpiece being processed at the required angle relative to the machine table
for periodically rotating the workpiece around its axis at a certain angle (dividing into equal and unequal parts)
for continuous rotation of the workpiece when cutting helical grooves or helical teeth of gears

Dividing heads are:

Limb with dividing disks:

universal
semi-universal
simple division
direct division

Limbless dividing heads - (without dividing disk) with a gear planetary mechanism and a set of replaceable gears
Optical dividing heads - for precise divisions and control operations

Typically, dividing heads are made single-spindle. Sometimes multi-spindle (two- and three-spindle) ones are used for simultaneous processing of two or three workpieces, respectively. Limbless dividing heads allow the dividing process to be carried out using replaceable gears. In this case, the handle of the dividing head is turned one or more full turns. However, the design and kinematic diagram of dialless dividing heads is much more complicated than dial ones.

Universal dividing heads UDG-D

Previously, the Leningrad Optical and Mechanical Association LOMO produced universal dividing heads UDG N-100, UDG N-135 and UDG N-160 with center heights H = 100, H = 135 and H = 160 mm.

According to the GOST 8615-69 standard, the main size of dividing heads is largest diameter of the workpiece D. According to the standard, a series of six standard sizes of heads is adopted: D = 160; 200; 250; 320; 400 and 500 mm. Model names UDG-D-160, UDG-D-200, UDG-D-250, UDG-D-400, UDG-D-500.

There are 1: 40 of these heads (N=40), i.e. the head spindle rotates a full turn in 40 turns of the handle.

Dividing heads UDG-D-160 allow you to divide the workpiece circumference into any number of parts ( division range) up to 400 parts, including prime numbers.

Universal dividing heads allow dividing workpieces using three methods: direct, simple and differential and are used to complete milling machines of domestic and foreign production.

Each size of the machine (according to the width of the table) must correspond to a certain standard size of the dividing head. Thus, for cantilever milling machines No. 2 (with a table width of 320 mm) we recommend a dividing head with the largest diameter of the workpiece being processed D = 250 mm, and for milling machines No. 3 (with a table width of 400 mm) - an UDG-D-320 dividing head etc.

Designation of high-precision (P) dividing heads:

UDG-D-160 - 7036-0051P
UDG-D-200 - 7036-0052P
UDG-D-250 - 7036-0053P
UDG-D-320 - 7036-0054P
UDG-D-400 - 7036-0055P

Designation of dividing heads of normal (N) accuracy:

UDG-D-160A - 7036-0051
UDG-D-200A - 7036-0052
UDG-D-320A - 7036-0054
UDG-D-250A - 7036-0053
UDG-D-400A - 7036-0055

UDG-160, UDG-D-160 universal dividing head. Purpose, scope

The dividing head UDG-160, UDG-D-160 makes it possible to perform various milling, hobbing, boring, drilling, marking and other work related to rotating a part at a given angle.

Machining of parts using a dividing head can be done in centers, in a chuck or on a spindle mandrel.

Using the universal dividing head, you can perform the following operations:

direct division of circles by a number that is an integer divisor of 24, i.e. on 2, 3, 4, 6, 8, 12, 24
simple division of circles into a number of parts from 2 to 400 and into some numbers over 400
differential division of circles into a number of parts from 43 to 400 without intervals
milling of spirals with pitches from 25 to 400 mm
gear milling
setting the axis of the workpiece at the required angle relative to the machine table
various works on milling machines related to dividing a circle into unequal parts in degrees, cutting spirals, etc.

UDG-160 General view of the dividing head

UDG-D-160 Design of a universal dividing head

Design of the dividing head UDG-D-160

For the UDG-160 dividing heads, the dividing disks for the simple and differential dividing method are double-sided with blind holes: on one side of the disk there are circles with the number of holes 16, 17, 19, 21, 23, 29, 30 and 31, and on the other side - 33, 37, 39, 41, 43, 47, 49 and 54.

The dividing disk for direct division is made graduated with a division value of 1°. The vernier mounted on the head body allows you to measure the angle of rotation of the spindle with an accuracy of up to 5".

The UDG-160 dividing head is supplied with a guitar and replaceable gears with the number of teeth: 25, 30, 35, 40, 50, 55, 60, 70, 80, 90 and 100.

To process elements of parts located on conical surfaces, for example, when milling cavities to form teeth of bevel wheels, countersinks, countersinks, etc., the body is rotated around a horizontal axis in a vertical plane at a given angle relative to the base of the head.

Dividing heads are usually available for installation on the left end of the workbench. However, domestic machine tool factories produce dividing heads designed for installation on the right side of the table.

The UDG-D-160 dividing head has a cast iron base 16 with tie rods 17, on which a housing 18 is installed. By loosening the nuts 19 (Fig. 3), you can rotate the housing to a certain angle. The rotation angle is measured using the scale and vernier 20 (see Fig. 2).

On the supporting plane of the base of the dividing head there are two keys that are precisely fitted parallel to the spindle, which are used to install the head in the groove of the milling machine table. The housing contains a spindle with a through hole. The ends of the spindle are bored to a Morse taper. A center 21 is installed at one end, and a mandrel 13 (see Fig. 1) for differential division is installed at the other. The front end of the spindle has a thread and a centering belt 22 (see Fig. 2) for installing and fastening a flange with a self-centering chuck or a driver. On the spindle collar there is a direct division dial 9, which has twenty-four holes.

On the spindle, in its middle part, sits a worm wheel with a circular groove at the end, into which the end of a clamp 23 mounted in the housing 18 fits. The worm wheel receives rotation from a worm located in an eccentric sleeve. The worm can be engaged or disengaged by turning the eccentric sleeve using handle 24 (see Fig. 3) with sector 25.

The dividing disk is mounted on a shaft mounted in sliding bearings in cover 26 (see Fig. 2). The cover is fixed on the body 18 with a centering bore and is fixedly attached to the base.

Bevel and cylindrical gears are installed on the shaft of the dividing disk, as well as a drive bar that has a handle with a lock that moves along the required row of holes on the dividing disk. A sliding sector 27, consisting of rulers 28 and a clamping screw 29, is pressed to the dividing disk using a spring, with the help of which the rulers are installed at the required angle. The spring washer prevents spontaneous rotation of the sector.

The mechanical drive shaft 30 from the machine is mounted in plain bearings and located in a sleeve 31 with a flange. The sleeve is attached to cover 26. At the end of the shaft there is a bevel gear, which is in constant mesh with the bevel gear sitting on the shaft of the dividing disk. The dividing disk is fixed in the required position with stopper 7.

Tailstock

The tailstock serves to support the second end of the workpiece when installing it in the centers or chuck of the dividing head. The center of the headstock can be moved in horizontal and vertical directions. At the base 32 there is a housing 33, which is connected to the rail by a pin. By rotating the head of the gear shaft, the housing can be raised, lowered and rotated relative to the axis of the pin. In the required position, the tailstock is secured to the machine table using bolts and nuts.

The movement of the quill 34 with the half-center 35 is carried out by rotation of the handwheel 36 mounted on the screw.

On the supporting plane of the base there are two guide keys, aligned with the axis of the quill; The keys ensure that the centers of the dividing head and the tailstock coincide when they are installed on the machine table.

Lunette

The steady rest is an additional support when processing long and thin parts. In its body 37 there is a screw that moves with the help of a nut 38. The screw has a prismatic head 39; with the help of a locking screw 40 the head can be secured at the required height.

UDG-160 Location of dividing head controls

List of controls for the dividing head UDG-160

Handle with lock. Fixing the dividing disk

Stopper. Locking the dividing disk

Latch. Fixing the direct division dial

Screw. Fastening the head housing to the base

Clamp Spindle lock
Lever. Turning the worm on and off

Sliding sector. Counting holes on the dividing disk

Handwheel. Moving the tailstock quill

Screw. Sector fastening
Screw. Leash attachment
Screw. Attaching the indexing disc clamp assembly
Shank. Guitar mount
Screw. Tailstock quill fastening
Gear head. Moving the tailstock vertically
Bolt. Tailstock housing mount
Screw. Fastening the bar with handle and lock

UDG-160 Lubrication points of the universal dividing head

I - Disc shaft and bevel gear. Lubricate daily
II - Cylindrical and bevel gears. Pouring 100 g of oil through the lid
III - Front spindle bearing. Lubricate daily
IV - Worm pair. Pouring 200 g of oil into the housing
V - Rear spindle bearing. Lubricate daily
VI - Quill and tailstock screw. Lubrication every two days
VII - Dividing head drive shaft. Lubrication every two days

At simple division rotation to the spindle 1 is transmitted from the handle 2 with a lock through a pair of spur gears 3, a worm 4 and a worm wheel 5 located in the middle part of the spindle. In this case, the dividing disk 6 must be secured using the stopper 7, and the clamp 8 of the direct division dial 9 is turned off.

At differential division The angle of rotation of the spindle is determined by the amount of rotation of the handle with the lock relative to the index disk and the amount of rotation of the disk itself, which receives rotation from the spindle through the replaceable gears 10 of the guitar 11 and a pair of bevel gears 12. To transmit rotation from the spindle to the replaceable gears of the guitar, a mandrel 13 is used, on a cylindrical neck in which the replacement gear 14 is installed. In this case, the dividing disk must be released from the stopper, and the direct division dial lock must be turned off.

At spiral cutting the spindle receives rotation from the lead screw of the milling machine through replaceable guitar gears, a pair of bevel gears 12, an intermediate shaft 15, spur gears 3, a worm 4 and a worm wheel 5. The dividing disk must be released from the stopper, and the direct division dial lock is turned off.

Operating procedure

Direct division

Direct division is used when dividing a circle into 2, 3, 4, b, 8, 12 and 24 parts in cases where great accuracy is not required.

When dividing directly, you must:

disengage the worm from engagement with the worm wheel by turning handle 24 (see Fig. 3) until it stops
release the direct division dial clamp from engagement

The spindle is turned by hand by rotating the workpiece or chuck. The angle of rotation is measured using a degree scale marked on the direct division dial and a line on the front spindle bushing.

Secure the spindle in the required position using clamp 23 (see Fig. 2).

When dividing into parts or faces, the calculation is made using the formula

N = 360°/a(1)

where n is the number of parts or faces; A

a is the spindle rotation angle.

Simple division

A simple division of a circle into equal and unequal parts is carried out with a stationary dividing disk using a handle with a lock. The amount of rotation of the handle is measured by the holes on the dividing disk and is fixed with a locking rod.

Differential division

Dividing a circle into a number of parts greater than 42, not a multiple of the number of holes on the dividing disk, can be done by a differential method, the essence of which is that the angle of rotation of the spindle is determined by the amount of rotation of the handle with the lock relative to the dividing disk and the amount of rotation of the disk receiving rotation from the spindle through replacement guitar gears.

The guitar is mounted on a cylindrical shank on which it can be rotated and secured in the desired position. To install replacement gears, the guitar is equipped with movable pins and adapter bushings. To transmit rotation to the replaceable gears, a mandrel is inserted into the rear cone of the spindle, onto the cylindrical neck of which the replaceable gear is installed.

Before starting work, turn the handle to check the smooth rotation of all installed gears.

When performing differential division, the indexing disk stop must be turned off.

The adjustment procedure for differential division is the same as for simple division.

Differential division is only possible with the spindle in a horizontal position.

Spiral Grooving

Milling of spiral grooves is carried out by longitudinal movement of the milling machine table and simultaneous rotation of the part fixed in the dividing head relative to its axis. For coordinated rotation of the part with longitudinal movement of the table, a guitar is installed with a set of replaceable gears that transmit rotation from the machine lead screw to the dividing head spindle.

Technical characteristics of the head UDG-160

Parameter name	UDG-160	UDG-200	UDG-250	UDG-320
Main settings
Accuracy class according to GOST 8-82	P	P	P	P
Center height, mm	85	105	130	165
Largest diameter of the workpiece, mm	160	200	250	320
Distance from the base of the dividing head to the end of the spindle in its vertical position: no more than, mm	180	235	280	350
Angle of rotation of the spindle in the vertical plane down from the center line: not less than, degrees	5	5	5	5
Angle of rotation of the spindle in the vertical plane upwards from the center line: not less than, degrees	95	95	95	95
Takar chuck diameter, mm	100	125	160	160
Spindle taper	Morse No. 2	Morse No. 3	Morse No. 4	Morse No. 5
Spindle end thread	M33	M39	M52	M60
Spindle hole diameter, mm	14,9	20,2	26,5	38,2
Worm gear ratio	1: 40	1: 40	1: 40	1: 40
Division range including prime numbers	2..400	2..400	2..400	2..400
Diameter of holes for replacement wheels, mm	20x19	20x19	20x19	32x19
Number of dividing disk holes	16,19,23 30,33,39 49	16,17,19 21,23,29 30,31	16,17,19 21,23,29 30,31	16,17,19 21,23,29 30,31
Number of dividing disc holes on the other side	17,21,29 31,37,41 54	33,37,39 41,43,47 49,54	33,37,39 41,43,47 49,54	33,37,39 41,43,47 49,54
Dividing value of the direct division dial, deg	15	15	15	15

A universal type dividing head (UDG) is used for processing metal workpieces on a milling machine. This element allows you to carry out several types of finishing operations on products, taking into account the features of their configuration, and is used for the production of complex parts. As a rule, the equipment is equipped with this device as standard. Otherwise, you will need to select the right model according to the characteristics of the existing turning device.

Purpose

The dividing head allows you to transform the workpiece into the desired configuration by displacing the part relative to the axis of the machine equipment.

The UDG is fixed on the unit frame by various types fastenings, depending on the type of nozzle. The working position is adjusted using movable handles and a disk, which is equipped with holes for attaching the dividing unit.

Features of the tool in question:

Milling of surface grooves. This process does not require perfect precision, subject to proper control of the depth and width of the workpiece being processed.
Ability to create edges on parts. This operation is advisable when manufacturing nuts with non-standard parameters, as well as working tools and workpiece shanks. Such manipulations require high precision.
Carrying out milling work on processing grooves and splines. In this case, significant movement of the workpiece may be required.

Peculiarities

The universal dividing head is used to increase the speed of work. However, it should not be subject to constant reinstallation. Changing the position in relation to the cutter is done by placing the device in the desired position. Particular attention must be paid to this process when forming screw-type grooves. Their production is possible only with the use of high-precision modification of the unit.

Before purchasing a dividing head, be sure to check its compatibility with your existing machine. Any home-made interventions in the design and unprofessional alterations can negatively affect the final quality of the product.

Specific properties

Taking into account the specifics of the tool in question, you should select a dividing head for a specific milling machine. Elements are divided into several types and types, differing in installation method, size, principle of operation and technical parameters.

Particular attention is paid to the accuracy of the work carried out. In addition, the complexity and accuracy of setting equipment parameters for operation are taken into account. This approach allows you to select a modification with high accuracy and acceptable errors. Having certain skills and suitable tools, UDG can be done independently.

Classification

Dividing heads for milling machines have the following classification:

Simple model. It is lightweight and easy to operate. The main part is the spindle, which fixes the workpiece and connects to the disk limb. This element has several holes that allow the workpiece to be shifted relative to the milling axis.
Combined options. The devices are adjusted using a handle. With a large number of clicks, the distance between the center axis of the workpiece and the cutter increases.
Universal samples are complex equipment that requires adjustment through the participation of a disk element and a handle. The process is carried out with the participation of differential gears.

Marking

Deciphering the markings of the dividing head will allow you to determine the model and the possibilities of its use. Using the UDG-40-D250 modification as an example, let’s look at the notation:

UDG - universal dividing head.
40 is a gear ratio indicating the number of revolutions of the spindle handle when turning 360 degrees.
D250 - maximum permissible dimensions of the workpiece being processed.

Setting up dividing heads

Possible tool transitions depend on the type of device and its technical parameters. The processing accuracy is determined by the divisions of the existing scale, the indicators of which correspond to the 7th (GOST-1.758) or 9th (GOST-1.643) calibration level.

The main setup process is to determine the dimensions of the pitch circle sector. In addition, the diameter of the circle and the number of compartments into which it is divided are taken into account.

The element configuration process consists of the following steps:

Transform 360 degrees of full diameter into the required number of divisions by sector.
The sine of the resulting calculated angle is determined.
The device disk is set according to this indicator.
The block body is fixed using a handle or a clamping mechanism, after which the working part of the tool is mounted.

The formula for calculating the required angle can be found in the UDG operating manual. The workpiece being processed is fixed on the machine mandrel, the table is longitudinally shifted, and finishing is performed. The feed pitch is affected by the type of processing. To increase productivity, after completing the next working cycle, they use an accelerated return of the table to its original position. The elements are fixed in the measuring holes of the disk using springs.

DIY dividing head

The disadvantages of the tool in question include its high cost. In this regard, you can make a dividing head for simple operations yourself. You will need a set of the following components:

A worm-type gearbox, which can be selected from the equipment of old machines or machined with your own hands.
with a dial (suitable size - 65 mm in diameter).
Limit screw.

Before the production process, the setting of the dividing part should be done. Any standard part or a machined figure of a certain format will help with this. After a comparative test with an analogue, additional calibration of the instruments is carried out. The cost of a do-it-yourself dividing head will be an order of magnitude lower than the factory equivalent, the price of which starts from 40-50 thousand rubles.