The design of the punch chuck is the main part of this power tool, which you need to pay attention to primarily when buying it.
When repairing a punch, most often you will have to replace the cartridge, the nuances of this process need to be studied thoroughly.
This solution allows you to determine exactly which nozzles can be used in the future, as well as how easy it is to replace the cartridge. After all, emergency repair is an important factor in the selection of an electric drill.
What is a punch chuck?
For the first time an electric rotary hammer was made in the 30s of the last century. The first electric drill was released by Bosch, which specializes in the production of household and industrial appliances. Torque, combined with cyclic chiselling, expectedly liked by all consumers. Since then, the power tool has never disappeared from the windows of hardware stores.
Diagram of the percussion mechanism of the drill.
But after the production of the first sample of equipment, most consumers faced some trouble. The main problem was the punch chuck. This was due to the fact that simultaneous slotting and drilling severely damaged the design of the socket for the nozzles.
Manufacturers of industrial equipment have found an easy solution to this problem - they have simplified the design of the cartridge, thereby strengthening its structure.
At the moment there are 2 different types of perforator cartridges:
- quick clamping
Each of them, in turn, is subdivided into several types.
A key type of cartridge is a nozzle, clamped with a special key, which fixes the cartridge from the inside using a crimp bar. It is also called gear or cam. The main advantage of this type of cartridge is an increased level of reliability when fastening. But often, replacing the cartridge requires a certain time, when compared with other types of nozzles.
The quick-release form of the cartridge is fixed by clamping the nozzle with a slight effort, this allows manual replacement. This mechanism is divided into 2 types: one- and two-coupling. The first type involves the installation with one hand, but it is used only in tools with self-locking shaft. The second type involves holding the rear clutch with one hand and unwinding the front clutch with the other.Back to table of contents
SDS cartridges (Steck, Dreh, Sitzt)
At the end of the 20th century, Bosch made a breakthrough and proved that the simplest design ensures high reliability of the device.
Diagram of the device clamping cartridge.
Thus, the newest fastening category for nozzles, which today everyone knows under the abbreviation SDS, was born. It stands for Steck, Dreh, Sitzt - set, roll, secure.
Virtually all electric drills today use this particular type of ammunition. Most consumers and inexperienced builders may confuse an SDS cartridge with quick-release devices, as many in our country call it. But it is worth remembering that this type of chuck is fixed by simply holding, and the quick-clamping device involves clamping the chuck by rotating the clutches.
All the features of fixing and functioning of the SDS nozzles are intuitively understandable from their appearance, namely from the structure of the tail section. You can see 4 main slots on it. The first 2 slots are open from the front side, the other 2 slots are closed. Open grooves perform the role of guides used for placement of nozzles. Closed grooves are designed to secure the device, for this purpose inside the cartridge there are special mechanisms in the form of balls. When you install the desired drill it must be carefully screwed, the mechanisms are fixed in closed grooves. The procedure for fixing the nozzle ends.
To keep the drill even easier, it is necessary to lightly lubricate its base. It should be noted that with this method of fastening in the nozzle there may be a slight beating during rotation, which manifests itself during dry movement. This has practically no effect on the drilling of the openings, but the idle movement of the drill inside the fastener leads the cartridge away from the shock pressure. Drilling nozzles are inevitably subjected to this.Back to table of contents
Varieties of SDS cartridges and their use
The fasteners of the cartridge punch type SDS are divided into 5 varieties, differing among themselves by different width of the rods for planting. In addition to SDS nozzles, there are also SDS-plus and SDS-max nozzles.
Drills for punch and their characteristics (table).
The variations of SDS-top and SDS-quick are less common. The most popular type is SDS-plus, which is intended for drill-type drill bits with a 10 mm tail width. The tail is placed in a 40 mm mount, after which there is already a functioning part, the width of which varies in the range of 4-26 mm.
The largest chisel size for equipment with a tail section of the SDS-plus type is 1 m. The most popular drills have a width in the range of 6-12 mm. This type of attachment is found in lightweight and middle class perforators. This class of electric drills is the most popular among consumers, its sales reach up to 1 million copies per year.
The lightweight class includes perforators, the mass of which reaches up to 3 kg. On the average class the equipment with a weight from 3 to 5 kg is presented. In this case, the weight of accessories, such as drills and nozzles, is not taken into account. Instruments of this class are designed for shock pressure up to 5 J.
Heavy-weight types of equipment, the mass of which starts from 5 kg, are capable of delivering shock power reaching 30 J. Of course, the speed of operation of such equipment exceeds the lower classes several times. When using these drills, you should use fasteners such as SDS-max. They differ in the width of the tail, which is equal to 18 mm. In addition, they provide an additional notch, which allows you to increase the width of the functioning part of the nozzle up to 60 mm.
This type of equipment is purchased when it is used daily. It is worth mentioning that the massive types of punch have a high cost, which later easily pays off, since this type of device is of the highest quality and durable. When buying it is worth picking up products of proven manufacturers.Back to table of contents
How to replace the cartridge punch?
Periodically it is necessary to disassemble the tool in order to clean it thoroughly in order to avoid untimely breakdowns and malfunctions.
In some cases it will be necessary to carry out a small repair, for which, in turn, it will be useful to know how to replace the cartridge punch.
This process does not require professional knowledge and skills; it can be implemented by any consumer who has basic concepts in electrical engineering. This is due to the fact that the SDS type cartridges have a similar design, regardless of the manufacturer.
Disassembly and lubrication of a pistol-type perforator.
For example, you can take as a basis the procedure for disassembling a Bosch punch chuck, since it is the world's leading manufacturer of such equipment.
The process of disassembling and assembling the cartridge on the punch is as follows:
- it is necessary to move the plastic part;
- rubber trim neatly removed;
- the fastening rim is carefully removed with the help of a screwdriver;
- fastening washer removed;
- Behind the mounting washer is the next bezel, dismantled with a screwdriver.
The next step is an SDS device consisting of a washer, a ball mechanism and a spring. First of all, the mechanism is removed, after which you can remove the spring and washer.
Back to table of contents
After thorough cleaning, lubrication of all elements or replacement of the cartridge with a new assembly is carried out in the same manner.
A few recommendations on the selection of nozzles for punch
Modern manufacturers of industrial equipment are trying to reach a large audience. In pursuit of the expansion of the consumer circle, they set up the production of special adapters that are designed to install the SDS-max nozzle on a power tool supporting the SDS-plus nozzle.
The higher the degree of twisting of the spiral in the nozzle, the faster the drilling process will be.
Using this type of adapter is completely safe for equipment, but it is strictly forbidden to purchase types of nozzles that increase the obviously smaller width of the socket for the nozzle.
Electrical equipment lightweight or medium category does not initially involve the use of nozzles that are intended for heavy equipment. The use of such adapters will quickly destroy the components of the punch, which would entail extra cash costs.
Drill bits for electric drills are most often distributed in packaged form. This is due to the fact that nozzles of this type are difficult to repair, they are much easier to replace with new ones.
The most popular drilling nozzles have external similarity with nozzles for drilling holes. But if you take a good look, you can see in them completely different design features of the thread and spiral.
It is worth paying attention to the degree of twisting spiral nozzles. The higher this figure, the easier it is to drill a hole. In addition, in the drilling process, the output of surplus has improved performance. At the same time, it is necessary to know that the drill bits of such varieties have a smaller margin of safety. High-strength nozzles are borax with the least degree of twisting of the spiral.