Drilling machine: device, principle of operation, application
A drilling machine is a device, which serves to form holes in parts of different materials. Technical capabilities of modern machines of this category allow you to use them not only to create holes, whose diameter reaches 100 mm, but also to perform a whole list of other technological operations.
You can choose the right drilling machine for any activity, be it a home workshop, car service or production shop
Application, design and principle of operation of drilling machines
Drilling machines allow to create through or blind holes in details from various materials. These technological operations are performed with the help of such a cutting tool, like a drill, due to which the removal of chips from the processed material is provided.
Most devices of this type are industrial drilling machines. Number of models for household use, differ in much smaller functionality in comparison with professional devices, slightly. Meanwhile, on the example of a simple design of household models, it is most convenient to get acquainted with the principle of operation of the drilling machine and its basic elements.
Small household drilling machine
The household model is, usually, desktop drilling machine, which differs in compact dimensions and is established on a machine surface or on any other increase, which provides ease of use. In the vast majority of cases it is a vertical drilling machine, whose device is the most typical for equipment for this purpose.
Basic elements of the drilling machine, used as a home, and in the home, perform:
- spindle head, in which the working cartridge is mounted, employee for fixing the cutting tool;
- drilling head, the design of which includes a spindle head, electric drive motor and belt drive;
- bearing rack-column, on which the drilling head of the equipment is mounted;
- massive base plate, made by casting of steel or cast iron (it performs two functions: serves as a reliable base for the machine and is used to secure the vertical rack of the equipment).
The main components of the drilling machine
Technological operations, for which the vertical drilling machine is intended, are performed by two movements of the spindle: main and auxiliary. The first movement is the rotation of the spindle assembly, and the second is its movement in the vertical direction. The vertical drilling machine received the name just for that, that its spindle makes the feed movement in the vertical direction. A special steering wheel is responsible for performing such a movement, located on the side of the body of the device.
Elements of construction of household drilling equipment and their interaction
Spindle assembly as a production, and household drilling machine is driven by an electric motor, reports the torque of the belt shaft. Drilling machines, intended for household use, are equipped with electric motors, whose power is 250-1000 W.
Asynchronous motor of the Sturm BD7037 desktop drilling machine with power 370 W
On many models of household drilling machines, the speed of the cutting tool can be adjusted, which is provided due to use in their design of shafts of a belt drive of various diameter. The principle of adjusting the spindle speed on such machines is quite simple: when the drive motor is switched off, the belt simply overturns in the groove of that part of the pulley, which has a different diameter. According to this principle, the spindle speed can be adjusted in the range 450-3000 rpm.
Proma PTB-16B230 belt drive unit
Drilling chucks are usually installed on household machines, identical to the clamping devices of hand-held electric drills. Such cartridges from 3 self-centering cams are designed to fix the drills, whose diameter reaches 12 mm. A special key is required to work with this cartridge, by means of which the clamp or loosening of fixing cams is carried out.
When choosing a machine, pay attention to the minimum diameter of the drill chuck - the cams of some models can not fix the drill bit caliber 3 mm
Technical possibilities of drilling machines of household purpose allow to process details, whose height is in the range 200-900 mm This parameter depends on, how high the drilling head can rise on the equipment rack. The principle of movement of the drilling head on the column of the machine in different models may vary. On the simplest and lightest devices the working head moves to the necessary height manually, and on the bigger and heavier equipment for this purpose the special handle-steering wheel is provided, which is connected to the drive mechanism.
A special handle is used to fix the drilling head in the required position and to install it at the required height before processing.. It is therefore necessary to adjust and fix the position of the working head before drilling, that the magnitude of the departure of the cartridge from the spindle assembly is quite small and is depending on the model of the unit 50-400 mm
Bodies for adjusting the drilling depth of the HC12A machine: 1 - pointer nut; 2 - pointer protrusion; 3 - steering wheel; 4 - clamp; 5 - locking screw; 6 - spindle sleeve
For this reason, the protection is attached to the strongest parts of the vehicle body, which evaluates any drilling machine, there is a departure of a drill. This parameter, which in different models of household appliances may be in the range 100-200 mm, characterizes the distance from the axis of rotation of the cutting tool to the axis of the rack-column (it depends on him, at what distance from the edge of the part you can drill a hole).
The main requirement for the base plate of the drilling machine, which must provide a stable position on any horizontal surface, is its massiveness and dimensions, enough for that, to balance the mass of other structural elements of the equipment.
The purpose of the upper part of such a plate is to serve as a desktop, therefore it is made as smooth as possible with several grooves. The central of these grooves is used when drilling through holes and is necessary for this, to avoid damage to the drill and the surface of the desktop in the process of performing such a technological operation. Other grooves on the desktop surface are required to secure the various clamps.
The base of the PROHHON-TBM-220 machine has slots for fixing vices
Vertical movement of the drill, fixed in the cartridge, is carried out due to the lever mechanism, actuated by a special handle. So the handle, located on the side surface of the machine body, specially spring-loaded, which provides automatic reset after that, as the influence on it ceases.
The electric motor on household models is powered mainly by mains voltage 220 V. It is started and stopped by a push-button station. On some models of household drilling machines, technical capabilities which allow you to cut internal threads, reversible start of the electric motor is provided.
Additional devices for household drilling machines
Desktop drilling machine, intended for home use, can be equipped with additional devices, which significantly increase its functionality and ergonomics.
Machine "Caliber SS-13" with an additional lifting work table
List the following devices.
- Desktop, which is mounted on a rack cantilever, which allows you to perform various actions: raise and lower it manually (in the simplest models of machines); use a special handle to change the height of the location, connected to the rail mechanism; fix at the required height. Some models of drilling machines for the house can be equipped with a desktop, which can not only move in the vertical direction, but also rotate about the vertical axis.
- Mechanism, which provides adjustment of drilling depth, operates on the following principle: drill tip, fixed in the cartridge equipment, lowered to the mark on the side surface of the part, corresponding to the required drilling depth. After that twist the long lever of the depth regulator, thereby limiting the movement of the cutting tool.
- Protective screen, which is a reclining fence made of transparent plastic, providing protection of the operator of the machine tool from flying shavings and does not allow getting into a zone of processing of parts of clothes and long hair.
Quick-release clamp of the BOSCH PBD drilling machine 40
Drilling machines for use in industrial conditions
Just look at the drawings or photos of production drilling machines, to understand, that they are much more complex devices, than household models. Most models of such machines are universal equipment, that allows to carry out not only drilling on metal and other materials, but also a number of other technological operations.
GILLARDON RF multi-spindle drilling machine 25
The following categories of devices belong to production drilling machines.
Desktop type machines
Such machines are small in size and light in weight. They are used for drilling holes, which have a small diameter.
Vertical drilling (columns) machines
These machines are used to equip small-scale and single productions. With their help it is possible to receive preparations from metal of an aperture, whose diameter is in the range 18-75 mm
Radial drilling machines
This equipment is used for machining solid metal parts or workpieces, in which it is necessary to form holes with centers, located on the arc of a circle. The device of the drilling machine of this category characterizes rather big departure of a spindle knot, the value of which can reach 1300-2000 mm.
Coordinate drilling devices
The use of such machines is relevant in those cases, when there are high requirements for the accuracy of the location of several holes in the part.
Horizontal drilling machines
Holes are processed on these devices, differing in considerable depth (it's raining, axis, rods, etc.).
Centering machines
Such equipment is used to form center holes, located at the ends of the workpieces.
Multi-spindle machines
On aggregates, equipped with several spindle heads, many holes can be machined simultaneously, located in the vertical, horizontal and inclined planes.
Combined machines
On drilling and milling devices, drilling and turning, drilling and grooving and a number of other categories can simultaneously perform different technological operations.
Universal drilling and milling machine Stalex-LM1450-2
The most common are machines vertically - and horizontally drilling group. Many modern models of drilling machines are equipped with numerical program control systems, that allows to seriously increase productivity of such equipment and to provide high accuracy of processing. Machines with such a control system are used mainly to equip serial and large-scale production plants.
Among the special drilling equipment should be mentioned magnetic machines, which are used to obtain holes in large parts. Such devices, equipped with a special magnetic base are placed directly on the surface of the workpiece and securely held on it due to a strong magnetic field. The big advantage of machines of this category is that, that they can be placed in any spatial position.
The unique design of magnetic machines makes it possible to process metal there, where this cannot be done with conventional equipment
Though, that any machine of the drilling group can be used to obtain holes in the workpieces of different materials, special models are created for woodworking and furniture factories, which can be equipped with one or more spindles, including rotary working heads. With this equipment you can not only make holes in the details of wood, but also to create nests, watch out, remove knots.
Use of modern drilling and filler equipment in furniture factories, which has great versatility and functionality, allows you to quickly make furniture structures with it, even according to the most complex drawings.
Capabilities and device of industrial drilling equipment
Drilling equipment, intended for industrial use, arranged much more complicated, than household models. This is noticeable, as mentioned above, even on a photo of such units. Feeding tools on this equipment can be fed not only manually, but also in automatic mode. Almost any of these machines has the ability to adjust the speed of rotation of the spindle assembly and the feed rate, for which the gearbox and the gearbox are responsible, respectively.
Desktop drilling machines of a professional class differ from household models by high-precision accessories, starting from the main bearings and ending with the chuck
Because such machines are used more intensively and to solve responsible tasks, their kinematic scheme is more complex and reliable. Many of the modern models of these devices have the option of automatically reversing the direction of feed and rotation of the cutting tool at that time, when it reaches the required depth of processing.
The spindle assembly of the majority of models of such equipment is equipped with the mechanism of automatic supply of a surface of the processed detail. An almost mandatory option for these machines is the automatic supply of coolant to the treatment area at that time, when such processing begins.
Construction of a drilling head of an industrial machine
Recently, industrial enterprises are actively equipped with drilling machines, whose work is controlled by the CNC system. The advantage of using such equipment is that, that they automated the main and auxiliary technological operations, which allows you to significantly increase their performance compared to models, manually operated.
Industrial machines of the drilling group, as mentioned above, capable of performing various technological operations:
- deployment of holes;
- processing of openings with use of a countersink;
- chamfering at the top of the holes, formation of cylindrical and conical recesses - countersinking;
- processing of openings by means of tsekovka;
- internal thread cutting;
- processing of openings by means of a cutter - boring;
- finishing of openings by means of ball or roller tools - smoothing;
- processing of details by means of the milling tool (formation of grooves, etc.).
Chip recesses on an industrial machine
Rules of work on the drilling machine
Drilling equipment may be associated with a risk of injury to the operator, if safety requirements are not met. In particular, risk to the health and even the life of the operator, working on the drilling unit, can represent:
- machine elements, which in the process of processing rotate and move linearly;
- conductive elements;
- machined parts and tools, which at insufficiently reliable fixing can fly out of a processing zone.
The most important safety requirement for drilling equipment is the use of technically sound and proven devices and tools (and only for their intended purpose).
The cutting tool is of great importance for the proper operation of the machine and obtaining high-quality holes with its help. It must be well and properly sharpened, and also selected in accordance with the material details, in which it is necessary to drill holes. In the process of processing the cutting tool is intensely heated, which can lead to its rapid wear and failure. To minimize risk, in the process of processing it is necessary to cool the tool with a special liquid or ordinary water.
The process of drilling holes has some features, the depth of which is greater 5 diameters of the tool used. In the process of forming such holes, the tool should be periodically removed and free the unfinished hole from the accumulated chips, which can cause the drill to jam.
In general, the technique of work on drilling equipment and the rules of its regular preventive maintenance do not cause great difficulties, you can learn them quickly enough. If you follow these rules, the equipment will last you a long time, and you will be able to use it effectively to obtain accurate and high-quality holes.
