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 cantilever universal milling and wide-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 of such heads is fixed on the head spindle and has divisions in the form of slots or holes (in the number of 12, 24 and 30) for the latch latch. Discs with 12 holes allow you to divide one revolution 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 manufactured dividing disks of the head can be used for other division numbers, including for dividing 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, and impart continuous rotation to the workpiece when milling helical grooves.

In the domestic industry, universal dividing heads of the UDG type are used on cantilever universal milling machines (Fig. 1, a). Figure 1, 6 shows auxiliary accessories for dividing heads of the UDG type.

On widely-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 differences in the kinematic diagram). The settings for both types of heads are identical.

As an example in Fig. 1, a shows a diagram of processing a workpiece by milling using a universal dividing head. The workpiece / is installed on a reference in the centers of the spindle 6 of the head 2. and the tailstock 8. Modular disk cutter 7 from the spindle milling machine receives rotation, and the machine table receives a working longitudinal feed. After each periodic rotation of the gear blank, the cavity between adjacent teeth is machined. After processing the cavity, the table quickly moves to its original position.

Rice. 1. Universal dividing head UDG: a - diagram of the installation of 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 driver; 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 using the dividing head, rotate its spindle 6 with handle 3 along the dividing disk 4 with the dial. When the axis of the handle 3 enters the corresponding hole in the dividing disk, the spring device of the head fixes the handle 3. On the disk on both sides there are 11 circles concentrically located with the number of holes 25, 28, 30, 34, 37, 38, 39, 41, 42 , 43, 44, ^7, 49, 51, 53, 54, 57, 58, 59, 62, 66. Kinematic diagrams of universal dividing heads are shown in Fig. 2. In universal dial dividing heads, rotation of handle 1 (Fig. 2, a-c) relative to dial 2 is transmitted through gears Zs, Z6 and a worm gear Z7, Zs to the spindle. The heads are configured for direct, simple and differential division.

Rice. 2. Kinematic diagrams of universal dividing heads: a, b, c - limb; g - without limbs; 1 - handle; 2 - dividing dial; 3 - stationary disk. The direct division method is used to divide a circle into 2, 3, 4, 5, 6, 8, 10, 12, 15, 18, 24, 30 and 36 parts. When dividing directly, the rotation angle is counted using a 360" graduated disk with a division value V. The vernier allows this measurement to be carried out with an accuracy of up to 5". The angle a, degrees, of rotation of the spindle when dividing into z parts is determined by the formula
a=3600/z
where z is the specified number of divisions.

With each rotation of the head spindle, to the reading corresponding to the position of the spindle before rotation, add a value equal to the value of angle a found by formula (5.1). The universal dividing head (its diagram is shown in Fig. 2, a) provides simple division into z equal parts, which is performed by rotating the handle relative to the stationary disk according to the following kinematic chain:
1/z=пp(z5/z6)(z7/z8)
Where (z5/z6)(z7/z8) = 1/N; pr - number of handle revolutions; N - head characteristic (usually N=40).

Then
1/z=пp(1/N)
Where pp=N/z=A/B
Here A is the number of holes through which you need to turn the handle, 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 holes, and the rulers are fastened. If the left ruler of the sliding sector 5 rests against the handle latch, then the right one is aligned with the hole into which the latch must be inserted during the next turn, after which the right ruler rests against the latch. For example, if you need to configure a dividing head for milling the teeth of a cylindrical wheel with Z = 100, with head characteristic N = 40, then we get
pr - N/z = A/B = 40/100 = 4/10 = 2/5 = 12/30, i.e. A = 12 and B = 30.

Consequently, the circumference of the dividing disk with the number of holes B = 30 is used, and the sliding sector is set to the number of holes A = 12. In cases where it is impossible to select a dividing disk with the required number of holes, differential division is used. If for the number z there is no required number of holes on the disk, take the number zф (actual) close to s, for which there is a corresponding number of holes. The discrepancy (l/z- l/zф) is compensated by additional rotation of the head spindles to this equality, which can be positive (additional rotation of the spindle is directed in the same direction as the main one) or negative (additional rotation is in the opposite direction). This correction is carried out by additional rotation of the dividing disk relative to the handle, i.e. if when simple division the handle is rotated relative to the stationary disk, then during differential division the handle is rotated relative to the slowly rotating disk in the same (or opposite) direction. From the head spindle, rotation is transmitted to the disk through replaceable wheels a-b, c-d (see Fig. 2, b) a conical pair Z9 and Z10 and gears Z3 and Z4.
The amount of additional rotation of the handle is:
prl = N(1/z-1/zф)=1/z(a/b(c/d)(z9/z10)(z3/z4)
We accept (z9/z10)(z3/z6) = C (usually C = I).
Then (a/b)(c/d)=N/C((zф-z)/zф))

Let's say you want to set up a dividing head for milling the teeth of a cylindrical wheel with g = 99. It is known that N-40 and C = 1. The number of handle revolutions for simple division is PF-40/99. Considering that the dividing disk does not have a circle with the number of holes 99, we take t = 100 and the number of handle revolutions is PF-40/100 = 2/5 = 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 (A = 12) when dividing. The gear ratio of replacement wheels is determined by the equation
and = (a/b)(c/d) = N/C= (zф-z)/z) = (40/1)((100 - 99)/100) = 40/30 = (60/30) x (25/125).
Dividing heads without dials (see Fig. 2) do not have dividing disks. The handle is turned one turn and fixed on a fixed disk 3. With a simple division into equal parts, the kinematic chain has the form:
Considering that z3/z4=N,
We get (a2/b2)(c2/d2)=N/z

Increase functionality production equipment is possible after installing the 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 the desired shape it may need to be shifted relative to the machine axis. 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 provisions various options fixation of 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 specific type equipment, its compatibility with the machine must be checked. 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 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. Special attention is given 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 choose models with high accuracy, And acceptable indicators errors. 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. How larger number pressing - the greater the distance between the central axis of the workpiece and the 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 manufactured according to individual 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

Calculation table of divisions

Self-production

One of the disadvantages of factory models is their high cost. Therefore, to perform simple operations, it is manufactured homemade design. 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 lathe chuck(optimal diameter - 65 mm) and 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:

Turning and milling equipment is designed to carry out work related to the mechanical removal of metal from a workpiece to give it the required shape and size. To perform some work, additional equipment is required, for example, a universal dividing head installed on milling equipment.

Today it is found quite often, as it allows for processing complex surfaces. As a rule, the rotary head for a milling machine is manufactured and installed at the time of release of the equipment itself, since it is quite difficult to select the most suitable type of equipment. Let's take a closer look at this device.

Purpose of the equipment

Homemade dividing head for lathe or milling equipment is installed to offset the part relative to the axis of the installed cutting tool with certain indicators. In this way, it is possible to achieve precise positioning of the tool and the workpiece relative to each other in each position. The device can be used for various types of processing.

In order for work to be carried out with high precision, it is also important to eliminate the possibility of vibration of the device. A variety of fastening methods are used, it all depends on the design features. The position can be adjusted during operation of the machine using a movable disk or handle.

The capabilities of the equipment in question include the following points:.

For normal processing, such equipment is not required.

Device classification

Dividing head for a milling machine, a table of technical parameters determines what kind of work can be carried out on a particular equipment. Considering the classification of the dividing head, we note the following types of device.

Repairing almost every design option is complicated, since you need to know the principle of operation and carry out the manufacture of all parts.

DIY making

The cost of such equipment can be quite large. This is why many people wonder how to make a dividing disk with their own hands. A drawing of the future product is created depending on the characteristics of the equipment on which the dividing head will be installed. In addition, you will need the following components.

1. Lathe chuck with dial.
2. Limit screw.
3. A worm gearbox, which can be obtained by dismantling old machines or made with your own hands.

After manufacturing the product, the dividing part is adjusted. To do this, you can use any previously manufactured part. After obtaining certain results, a final calibration is performed, which can significantly improve the processing accuracy.

It’s no secret to milling specialists how to use a dividing head, but many people don’t even know what it is. It is a horizontal machine tool that is used on jig boring and milling machines. Its main purpose is to periodically rotate the workpiece, during which division into equal parts occurs. This operation is relevant when cutting teeth, milling, cutting grooves, and so on. With its help you can make gear teeth. This product is often used in tool and machine shops, where it helps to significantly expand the operating range of the machine. The workpiece is secured directly in the chuck, and if it turns out to be too long, then in a steady rest with emphasis on the tailstock.

Types of work performed

The UDG device allows you to provide:

• Precise milling of sprockets, even if the number of teeth and individual sections is several dozen;
• It is also used to produce bolts, nuts and other parts with edges;
• Milling of polyhedra;
• Grooving the depressions located between the teeth of the wheels;
• Grooving of cutting and drilling tools(for which continuous rotation is used to obtain a spiral groove);
• Processing the ends of multifaceted products.

Methods of performing work

The dividing head can be operated in several ways, depending on specific situation and which operation is performed with which specific workpiece. Here it is worth highlighting the main ones that are most often used:

• Direct. This method carried out by rotating the dividing disk, which controls the movement of the workpiece. The intermediate mechanism is not involved. This method is relevant when using such types of dividing tools as optical and simplified. Universal dividing heads are used only with a frontal disc.
• Simple. With this method, counting is carried out from a stationary dividing disk. The division is created using a control handle, which is connected through a worm gear to the spindle on the device. With this method, those universal heads are used on which a dividing side disk is installed.
• Combined. The essence of this method is manifested in the fact that the rotation of the head itself is a kind of sum of the rotation of its handle, which rotates relative to the dividing disk, located motionless, and the disk, which rotates with the handle. This disk moves relative to the pin, which is located on the rear clamp of the dividing head.
• Differential. With this method, the spindle rotation appears as the sum of two rotations. The first refers to the handle rotating relative to the index disk. The second is the rotation of the disk itself, which is carried out forcibly from the spindle through the entire system of gear wheels. For this method, universal dividing heads are used, which have a set of replaceable gears.
• Continuous. This method is relevant when milling spiral and helical grooves. It is produced on optical heads, which have a kinematic connection between the spindle and the feed screw to the milling machine, and universal ones.

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Design and principle of operation of the dividing head

To understand how the dividing head works, you need to know what it consists of. It is based on housing No. 4, which is fixed on the machine table. It also has a spindle No. 11, which is mounted on bearings No. 13, No. 10 and head No. 3. Worm #12 drives worm wheel #8. It is connected to flywheel No. 1. Handle No. 2 serves to secure the spindle, and therefore the worm wheel. It is connected to pressure washer No. 9. The worm wheel and worm can only rotate the spindle, and the error in their operation does not affect the overall accuracy.

One of the ends of the roller is seated in the eccentric bushing, which allows them to be lowered down together. If you disengage the spindle wheel and the worm, you can rotate the spindle head. Inside the case there is a glass disk No. 7, which is rigidly fixed to the spindle No. 11. The disk is lined with a 360 degree scale. Eyepiece No. 5 is located on top of the head. A handwheel is used to turn the spindle the required number of degrees and minutes.

Work order

When the operation is performed directly, the worm gear is first disengaged from the hook, for which it is enough just to turn the control handle to the appropriate stop. After this, you should release the latch that stops the dial. The spindle is rotated from the chuck or from the part being processed, which allows you to place the device at the desired angle. The angle of rotation is determined using a vernier, which is located on the dial. The operation is completed by securing the spindle using a clamp.

When the operation is performed in a simple way, here you first need to fix the dividing disk in one position. Basic operations are performed using the locking handle. The rotation is calculated according to the holes made on the dividing disk. There is a special rod to fix the structure.

When the operation is performed in a differential manner, the first thing you need to do is check the smooth rotation of the gears that are installed on the head itself. After this, you should disable the disk stopper. The setup procedure here completely coincides with the setup order when in a simple way. Basic work operations are performed only with the spindle in a horizontal position.

Division table for dividing head

Calculation of the dividing head

The division into UDG is carried out not only according to tables, but also according to a special calculation that you can do yourself. This is not so difficult to do, since only a few data are used in the calculation. Here you need to multiply the diameter of the workpiece by a special factor. It is calculated by dividing 360 degrees by the number of division parts. Then you need to take the sine from this angle, which will be the coefficient that needs to be multiplied by the diameter to obtain the calculation.

UDG.Cutting gear teeth: Video

There are a number special devices, which help or themselves secure the workpieces. These devices also include milling heads. And all these actions are performed on a slot milling machine mounted on a table. It is precisely this device that allows us to say that they not only have some kind of strengthening function, but, first of all, help expand all the capabilities of such a machine, making work on it more practical and convenient.

So what is the purpose of a dividing head for milling machines? Such heads are necessary in order not only to secure the workpiece itself, but also to help rotate it in order to carry out continuous rotation to process some part. But such heads can be different designs and, accordingly, they can be divided either into equal parts or into unequal parts. But it depends on what exactly is being processed: drills, reamers.

Using milling heads

Dividing head, which allows the machine to rotate the workpiece by different angles, performs well in milling grooves, which can be straight, conical and cylindrical. If the device is properly configured for operation, then along the entire circumference of the required workpiece the grooves will be placed the way you need them.

Such heads can be found most often on machines called horizontal milling, but on condition that the customer himself requires it. But on universal milling machines such a detail is required, otherwise such equipment simply will not be able to work.

Types of dividing heads

To ensure high performance of milling machines, very often in large production they use such dividing heads as multi-spindle. But there are other divisions of such a mandatory part for the manufacture and processing of the workpiece.

Types of dividing heads:

1. Simple.
2. Universal.
3. Optical.

Let us briefly describe each of these types. So, simple ones are the simplest type in their design. It is very easy to operate such a dividing part; it does not require any other special knowledge or skills. Even a person who is just starting to work with milling equipment can work with such a head.

Characteristics of a simple dividing head

Typically, such a simple part is well suited for producing and processing those workpieces that need to be produced in large quantities and in short terms.

Elements of the dividing part:

1. Spindle.
2. Limbo.
3. Three-jaw chuck.

Now briefly about the purpose of each element that is used in the milling machine. The end of the spindle helps to secure the part that will be processed. The dial is also attached to the spindle.

All milling masters know that the dial is a dividing disk that allows the heads to divide the workpiece into a certain number of parts, which will be equal. But you can try and change this value so that the division occurs into unequal intervals.

A three-jaw chuck can only be on the dividing head spindle if it is positioned vertically. If the spindle is located, then such an element of a simple head design is not needed.

Characteristics of the universal dividing head

The universal part is characterized by complex design. And this indicates that such a dividing part for a milling machine can be used only for single workpieces, but it will not be possible to produce a large series of such workpieces, as was the case with a part of a simple design. You could even say that for this type they use blanks that are only used for some kind of experimentation.

But for repairs, such universal dividing heads are simply ideal. There are several models of dividing parts of a similar design: UDG -200, UDG - 320 and others. But they have all been produced since about 1980.

Characteristics of the optical dividing head

First of all, it is worth noting that indexing heads for optical milling machines are necessary in order to produce accurate angular readings, which Allows for correct unfolding of workpieces. With this design of the dividing head it is possible to produce cutting tools which will contain many blades.

The optical separation structure may include the following elements: two guitar replacement wheels, tailstock, front center, leash for him, jack, and pads different types, there must be a mandrel in order to secure the parts.

How to set up a dividing head for a milling machine

In order for the machine to work properly and without interruptions, it is necessary to properly prepare the dividing part for the operation of the milling machine. To do this, secure the gear blank you have using nuts. Such a workpiece is secured to a mandrel.

And to do this, they begin to clamp the mandrel in a three-jaw chuck, which is then gradually screwed on on horizontal or vertical spindle the dividing head itself. The other end of the mandrel is supported using the tailstock. After this, the cutter disk is also secured to the spindle mandrel and installed directly in the very center of the workpiece.

But this can only happen if you lift the table. It must be raised to such a height that the central part of the mandrel of the required workpiece is not at the level of the cutter, or rather its lower part. After this, the table begins to move in the transverse direction so that the central part also coincides with the top of the milling tooth.

After this, the table can be lowered and the milling workpiece can be brought in, but in such a way that the sheet that is located between them must be bitten. But don’t rush to do the cutting right away, but check again the setup and, accordingly, the settings of the machine.