Puncher appointment. Rotary hammers, their characteristics and comparison of different models

• Purpose and functions
• Rotary hammer specifications
• Classification
• Cartridges
• How to work with a puncher
• Rotary hammer maintenance

For professional builders and those who like to build and repair with their own hands, a hammer drill is an indispensable tool that allows you to quickly and efficiently perform many works with stone, concrete or brick.

Purpose and functions

The name of the instrument comes from the Latin word "perforo", which means "to punch". The principle of operation of the rotary hammer is to apply strong and quick blows to a rotating or stationary nozzle. The tool is mainly intended for drilling holes in concrete, reinforced concrete and brick structures during construction or renovation works... In addition, some models of rotary hammers can be used as conventional drill for drilling metal, wood and plastic or a small jackhammer for chipping stone surfaces, cutting niches, chipping ceramic tiles etc.

Functionally, perforators are available in one, two and three modes. Single-mode tools have a single action - impact rotation. Dual-mode can have two combinations of actions: rotation without impact and rotation with impact or impacts without rotation (chiselling) and rotation with impact. The three-mode hammer drill has all possible types of action - rotation without impact, rotation with impact and chiselling.

Rotary hammer mode switch (Bosch). Between "Drilling with hammering" and "Hammering without drilling" - the position for changing the position of the chisel (Vario-Lock).

Rotary hammer specifications

The main technical characteristics of rock drills include the following parameters: engine power, single blow energy, "drilling" diameter, chuck rotation speed, blow frequency, weight.

Engine power electro-pneumatic rock drills range from 250 to 1500 W. The most popular are hammer drills with a power of 500-800 watts. They are widely used in everyday life as a versatile tool for drilling and chiselling.

Impact energy is the most important characteristic of rock drills. If we talk about electro-pneumatic types of tools, then it is equal to the energy possessed by the ram (see figure below) striking the striker. Its value can be determined by known formula mv 2/2, where m is the mass of the ram; v - its speed at the moment of contact with the end face of the striker. The impact energy is spent on the destruction of the material and heating the parts of the impact mechanism. Part of it returns to the ram, imparting to the latter the movement of the rebound from the striker. Electro-pneumatic rock drills have an impact energy of 1.5 to 20 J, light battery models can have less than 1 J.

The device of the percussion mechanism of the perforator: 1 - drunk bearing, 2 - piston, 3 - ram, 4 - striker (firing pin), 5 - engine gear.

"Drilling" diameter- a characteristic no less important than the impact energy. In the end, what matters is not how much energy the hammer drill has, but what diameter the hole can be and how quickly it can be made with it. The diameter of the "drilling" of a particular hammer drill model has different meanings - depending on the material being processed and the type of nozzle used.

Typically, drill specifications indicate the diameter of the "drill" for concrete and steel, sometimes for wood. The diameter of the "drilling" in concrete is usually 1.7-2 times the diameter of the drilling in metal. It also depends on the type of nozzle used - a solid drill or a hollow crown. The diameter of the hole obtained by the crowns is approximately three times the size of the hole obtained by the drill.

If we take the entire range of existing models of rotary hammers, then with their help in concrete walls it is possible to drill holes with a diameter from 4 to 150-160 mm. The last value is indicated for the crown. For the most popular hammer drills with a power of 600-800 W, the diameter of "drilling" in steel is usually 13 mm, in concrete - 22-26 mm for a drill and 60-65 mm for a crown.

Chuck rotation speed for all rotary hammers it is relatively small, it exceeds 1000 rpm only for light models, decreasing to several hundred for medium models and reaching 100-300 for heavy ones. The speed control range for many models is unlimited - from zero to maximum values.

Number of strokes per minute also depends on the class of the punch. For light models, it can reach 4000-5000 beats / min at a nominal speed, for heavy models, 1000-2000 beats / min.

Weight perforators depends on their power and ranges from 2 to 12 kg.

Classification

Perforators are classified according to different parameters - type of drive, power and weight, purpose, type of cartridge.

By drive type perforators are divided into electric (battery or network), gasoline and pneumatic. The most common hammer drills are electrically driven. Cordless models are mobile tools and are used where power is not available. In explosive environments, pneumatic rock drills are used. For road repair work, petrol models of the tool are indispensable. The last two are classic jackhammers, and this article is absolutely not about them.

By destination perforators are divided into household (amateur) and professional. As a rule, light perforators belong to household ones. Medium and heavy are professional instruments.

Sometimes rock drills are classified by type of cartridge which determines the shank diameter of the tool being used. Currently, mainly SDS standard cartridges are used - standard sizes SDS-plus and SDS-max (see below for cartridges). The chuck type indirectly characterizes the power and weight of the tool. So if it says that a rotary hammer is equipped with an SDS-max chuck, it means that we are talking about a heavy and powerful professional tool.

The main classification is still recognized by mass and power, depending on which the following classes of rotary hammers are distinguished:

• Light class, which includes hammer drills weighing up to 4 kg, with a power of 400-700 W and an impact energy of 1.5-3 J. About 80% of all rock drills belong to the light class. They are widely used in everyday life and are often universal - they have three modes of operation.
• Middle class includes hammer drills weighing 5-8 kg, power 800-1200 W and impact energy up to 8 J. Instruments of this class most often have two modes of operation - impact with rotation and impact without rotation. This tool is used mainly for professional work.
• Heavy class perforators are characterized by a weight of more than 8 kg, a power of 1200-1500 W and an impact energy of up to 20 J. Heavy tools have two modes of operation - impact without rotation and impact with rotation and are used exclusively for professional work.

Cartridges

The specificity of the perforator operation - the application of strong and quick blows to the nozzle - necessitated the development of a special cartridge that would provide a quick replacement of various attachments and allow the cartridge itself to be excluded from the shock chain. Such a device was developed by Bosch in 1975-1977. It has two features. The first and the main one is that the tool, fixed in the chuck, has a certain degree of freedom in the axial direction relative to the latter. This allows you to hit the nozzle (drill, bit, chisel) without simultaneously exposing the cartridge itself and the entire hammer drill as a whole to a strong impact (how it works, see the article Punch device ). The second feature is the ability to quickly change tools - with just two movements. The patron was given the abbreviation SDS (Steck - Dreh - Sitzt), which is German means - insert, turn, done! In total, three standard sizes of SDS standard cartridges have been developed - SDS-plus, SDS-top and SDS-max.

SDS-plus chuck serves for fastening tools with a shank with a diameter of 10 mm. 4 grooves are made on the cylindrical surface of the shank - two outgoing to the end (open), two not outward (closed). Open grooves are guides for inserting the tool, closed ones are used to lock it with the locking balls of the chuck. The fixed shank can be freely displaced by a certain amount in the axial direction. For easy axial displacement, the shank is lubricated with a small amount of grease. The SDS-plus chuck is used in light and partially medium rotary hammer drills for holding tools with a working diameter (diameter of "drilling") up to 26 mm.

Shank for SDS-plus chuck: 1 - rod with a diameter of 10 mm, 2 - closed groove, 3 - the shank is inserted into the chuck by about 40 mm, 4 - open groove, 5 - guide, 6 - locking ball, 7 - shank.

SDS-max chuck designed for shank diameter 18 mm. It has 3 open and 2 closed slots. Tools with this shank are designed for drilling holes over 20 mm. They are used for rock drills of medium and heavy class.

Shank for SDS-max chuck: 1 - rod with a diameter of 18 mm, 2 - closed groove, 3 - the shank is inserted into the chuck by about 90 mm, 4 - open groove, 5 - guide, 6 - stopper, 7 - shank.

SDS-top intermediate chuck for shanks with a diameter of 14 mm is less common. It was designed to prevent the failure of 16-25 mm diameter bits with SDS-plus shank, as the latter would sometimes fail and break. However, the SDS-top cartridge was not widely used.

Shank for SDS-top chuck: 1 - rod with a diameter of 14 mm, 2 - closed groove, 3 - the shank is inserted into the chuck by about 70 mm, 4 - open groove, 5 - guide, 6 - locking ball, 7 - shank.

Since many hammer drill models have the function of drilling without hammering, it is possible to install a conventional chuck for drills with a cylindrical shank on them. It is implemented in two ways. In the first case, a special adapter is used, which, on the one hand, has an SDS-plus shank, and on the other, a threaded part, onto which a three-jaw chuck is screwed and clamped with a screw - a gear-girth (ZVP) or quick-clamping (BZP) chuck.

The shank of the SDS-plus adapter is inserted into the hammer drill chuck and a structure is obtained from two series-connected chucks - SDS and three-jaw. The disadvantage of this option is the lack of sufficient rigidity of the drill attachment and its runout during rotation.

The second way is free from these disadvantages. It involves equipping the rotary hammer with a quick-change chuck system, which allows you to quickly, literally in one move, replace the SDS-plus chuck with a cam-type chuck adapted for installation on a rotary hammer.

There is a large number of all kinds of hammer attachments designed to perform the most various works... The main ones include drills, crowns, chisels and strobers. All rock drill bits are available with SDS-plus or SDS-Max shanks.

Drills are used for drilling round holes. Their main features are one plate or several teeth of carbide material at the end of the drill and the spiral shape of its shaft, which allows removing chips and dust from the holes during drilling.

Holes are made with crowns that perform not continuous, but circular cutting of the material large diameters... The material inside the crown remains intact and is removed as a core. Cutting is performed with carbide teeth mounted on the working edge of the tool. Holes in reinforced concrete should not be drilled with crowns, as the teeth can break off on impact with metal.

Chisels, lances, strobers are intended mainly for chipping stone surfaces. The former are also convenient for separating ceramic tiles from concrete foundations and splitting of stone materials. They are made from tool steel or hard alloys.

How to work with a puncher

The operating instructions supplied with the tool provide details on how to operate the hammer drill. Depending on the model, the operating procedure may have some peculiarities. However, in general it remains the same for all models and in general looks like this.

• Before installing the tool (drill, chisel, etc.), the perforator is disconnected from the mains.
• A small amount of grease is applied to the nozzle shank.
• The nozzle is inserted into the chuck. This action may vary slightly from model to model. Some require retraction of the chuck retainer sleeve. In others, the nozzle is simply inserted into the hole of the chuck and rotated until it clicks (with the locking balls installed in the closed grooves of the shank). When removing the tool, the chuck sleeve must be pulled back.
• If a drill is used to drill holes, the drilling depth stop is set to the required hole depth.
• If the rotation speed is not regulated by the trigger, then the required rotation speed of the drill is set using the speed regulator. It is recommended to start with the maximum values, as they provide the maximum tool performance.
• The hammer drill is connected to the network, and the trigger is pressed. In this case, the punch chuck should begin to rotate without impact.
• The accessory is set in the desired position in relation to the material being processed, and the pressure on the tool is not too strong. As a result, the drill or chisel begins to bite into the material.

Rotary hammer maintenance

The rock drill must be kept clean and dry. After work, it is necessary to clean and blow it from dust, wipe the case with a clean damp cloth. The blowing is carried out by the fan of the idling engine. Maintenance of the rock drill also includes replacement of brushes and lubrication of the gearbox at the time specified in the operating instructions.

The name of the instrument comes from the Latin word "perforo", which means "to punch". The principle of operation of the rotary hammer is to apply strong and quick blows to a rotating or stationary nozzle. The tool is mainly intended for drilling holes in concrete, reinforced concrete and brick structures during construction or renovation work. In addition, some models of rotary hammers can be used as a conventional drill for drilling metal, wood and plastic, or a small jackhammer for chipping stone surfaces, cutting niches, chipping ceramic tiles, etc.

Functionally, perforators are available in one, two and three modes. Single-mode tools have a single action - impact rotation. Dual-mode can have two combinations of actions: rotation without impact and rotation with impact or impacts without rotation (chiselling) and rotation with impact. The three-mode hammer drill has all possible types of action - rotation without impact, rotation with impact and chiselling.

Rotary hammer mode switch (Bosch). Between "Drilling with hammering" and "Hammering without drilling" - the position for changing the position of the chisel (Vario-Lock).

Rotary hammer specifications

The main technical characteristics of rock drills include the following parameters: engine power, single blow energy, "drilling" diameter, chuck rotation speed, blow frequency, weight.

Engine power electro-pneumatic rock drills range from 250 to 1500 W. The most popular are hammer drills with a power of 500-800 watts. They are widely used in everyday life as a versatile tool for drilling and chiselling.

Impact energy is the most important characteristic of rock drills. If we talk about electro-pneumatic types of tools, then it is equal to the energy possessed by the ram (see figure below) striking the striker. Its value can be determined by the well-known formula mv 2/2, where m is the mass of the ram; v - its speed at the moment of contact with the end face of the striker. The impact energy is spent on the destruction of the material and heating the parts of the impact mechanism. Part of it returns to the ram, imparting to the latter the movement of the rebound from the striker. Electro-pneumatic rock drills have an impact energy of 1.5 to 20 J, light battery models can have less than 1 J.

The device of the percussion mechanism of the perforator: 1 - drunk bearing, 2 - piston, 3 - ram, 4 - striker (firing pin), 5 - engine gear.

"Drilling" diameter- a characteristic no less important than the impact energy. In the end, what matters is not how much energy the hammer drill has, but what diameter the hole can be and how quickly it can be made with it. The diameter of the "drilling" of a particular hammer drill model has different meanings - depending on the material being processed and the type of nozzle used.

Typically, drill specifications indicate the diameter of the "drill" for concrete and steel, sometimes for wood. The diameter of the "drilling" in concrete is usually 1.7-2 times the diameter of the drilling in metal. It also depends on the type of nozzle used - a solid drill or a hollow crown. The diameter of the hole obtained by the crowns is approximately three times the size of the hole obtained by the drill.

If we take the entire range of existing models of rock drills, then they can be used to drill holes in concrete walls with a diameter of 4 to 150-160 mm. The last value is indicated for the crown. For the most popular hammer drills with a power of 600-800 W, the diameter of "drilling" in steel is usually 13 mm, in concrete - 22-26 mm for a drill and 60-65 mm for a crown.

Chuck rotation speed for all rotary hammers it is relatively small, it exceeds 1000 rpm only for light models, decreasing to several hundred for medium models and reaching 100-300 for heavy ones. The speed control range for many models is unlimited - from zero to maximum values.

Number of strokes per minute also depends on the class of the punch. For light models, it can reach 4000-5000 beats / min at a nominal speed, for heavy models, 1000-2000 beats / min.

Weight perforators depends on their power and ranges from 2 to 12 kg.

Classification

Perforators are classified according to different parameters - type of drive, power and weight, purpose, type of cartridge.

By drive type perforators are divided into electric (battery or network), gasoline and pneumatic. The most common hammer drills are electrically driven. Cordless models are mobile tools and are used where power is not available. In explosive environments, pneumatic rock drills are used. For road repair work, petrol models of the tool are indispensable. The last two are classic jackhammers, and this article is absolutely not about them.

By destination perforators are divided into household (amateur) and professional. As a rule, light perforators belong to household ones. Medium and heavy are professional instruments.

Sometimes rock drills are classified by type of cartridge which determines the shank diameter of the tool being used. Currently, mainly SDS standard cartridges are used - standard sizes SDS-plus and SDS-max (see below for cartridges). The chuck type indirectly characterizes the power and weight of the tool. So if it says that a rotary hammer is equipped with an SDS-max chuck, it means that we are talking about a heavy and powerful professional tool.

The main classification is still recognized by mass and power, depending on which the following classes of rotary hammers are distinguished:

• Light class, which includes hammer drills weighing up to 4 kg, with a power of 400-700 W and an impact energy of 1.5-3 J. About 80% of all rock drills belong to the light class. They are widely used in everyday life and are often universal - they have three modes of operation.
• Middle class includes hammer drills weighing 5-8 kg, power 800-1200 W and impact energy up to 8 J. Instruments of this class most often have two modes of operation - impact with rotation and impact without rotation. This tool is used mainly for professional work.
• Heavy class perforators are characterized by a weight of more than 8 kg, a power of 1200-1500 W and an impact energy of up to 20 J. Heavy tools have two modes of operation - impact without rotation and impact with rotation and are used exclusively for professional work.

Cartridges

The specificity of the perforator operation - the application of strong and quick blows to the nozzle - necessitated the development of a special cartridge that would provide a quick replacement of various attachments and allow the cartridge itself to be excluded from the shock chain. Such a device was developed by Bosch in 1975-1977. It has two features. The first and the main one is that the tool, fixed in the chuck, has a certain degree of freedom in the axial direction relative to the latter. This allows you to hit the nozzle (drill, bit, chisel) without simultaneously exposing the cartridge itself and the entire perforator to a strong impact (see how it works in the article Perforator device). The second feature is the ability to quickly change tools - with just two movements. The patron was given the abbreviation SDS (Steck - Dreh - Sitzt), which in German means - insert, turn, done! In total, three standard sizes of SDS standard cartridges have been developed - SDS-plus, SDS-top and SDS-max.

SDS-plus chuck serves for fastening tools with a shank with a diameter of 10 mm. 4 grooves are made on the cylindrical surface of the shank - two outgoing to the end (open), two not outward (closed). Open grooves are guides for inserting the tool, closed ones are used to lock it with the locking balls of the chuck. The fixed shank can be freely displaced by a certain amount in the axial direction. For easy axial displacement, the shank is lubricated with a small amount of grease. The SDS-plus chuck is used in light and partially medium rotary hammer drills for holding tools with a working diameter (diameter of "drilling") up to 26 mm.

Shank for SDS-plus chuck: 1 - rod with a diameter of 10 mm, 2 - closed groove, 3 - the shank is inserted into the chuck by about 40 mm, 4 - open groove, 5 - guide, 6 - locking ball, 7 - shank.

SDS-max chuck designed for shank diameter 18 mm. It has 3 open and 2 closed slots. Tools with this shank are designed for drilling holes over 20 mm. They are used for rock drills of medium and heavy class.

Shank for SDS-max chuck: 1 - rod with a diameter of 18 mm, 2 - closed groove, 3 - the shank is inserted into the chuck by about 90 mm, 4 - open groove, 5 - guide, 6 - stopper, 7 - shank.

SDS-top intermediate chuck for shanks with a diameter of 14 mm is less common. It was designed to prevent the failure of 16-25 mm diameter bits with SDS-plus shank, as the latter would sometimes fail and break. However, the SDS-top cartridge was not widely used.

Shank for SDS-top chuck: 1 - rod with a diameter of 14 mm, 2 - closed groove, 3 - the shank is inserted into the chuck by about 70 mm, 4 - open groove, 5 - guide, 6 - locking ball, 7 - shank.

Since many hammer drill models have the function of drilling without hammering, it is possible to install a conventional chuck for drills with a cylindrical shank on them. It is implemented in two ways. In the first case, a special adapter is used, which, on the one hand, has an SDS-plus shank, and on the other, a threaded part, onto which a three-jaw chuck is screwed and clamped with a screw - a gear-girth (ZVP) or quick-clamping (BZP) chuck.

The shank of the SDS-plus adapter is inserted into the hammer drill chuck and a structure is obtained from two series-connected chucks - SDS and three-jaw. The disadvantage of this option is the lack of sufficient rigidity of the drill attachment and its runout during rotation.

The second way is free from these disadvantages. It involves equipping the rotary hammer with a quick-change chuck system, which allows you to quickly, literally in one move, replace the SDS-plus chuck with a cam-type chuck adapted for installation on a rotary hammer.

There are a large number of all kinds of hammer drill bits designed for a wide variety of jobs. The main ones include drills, crowns, chisels and strobers. All rock drill bits are available with SDS-plus or SDS-Max shanks.

Drills are used for drilling round holes. Their main features are one plate or several teeth of carbide material at the end of the drill and the spiral shape of its shaft, which allows removing chips and dust from the holes during drilling.

Holes of large diameters are made with crowns that carry out not continuous, but circular cutting of the material. The material inside the crown remains intact and is removed as a core. Cutting is performed with carbide teeth mounted on the working edge of the tool. Holes in reinforced concrete should not be drilled with crowns, as the teeth can break off on impact with metal.

Chisels, lances, strobers are intended mainly for chipping stone surfaces. The former are also convenient for separating ceramic tiles from concrete substrates and for splitting stone materials. They are made from tool steel or hard alloys.

How to work with a puncher

The operating instructions supplied with the tool provide details on how to operate the hammer drill. Depending on the model, the operating procedure may have some peculiarities. However, in general it remains the same for all models and in general looks like this.

• Before installing the tool (drill, chisel, etc.), the perforator is disconnected from the mains.
• A small amount of grease is applied to the nozzle shank.
• The nozzle is inserted into the chuck. This action may vary slightly from model to model. Some require retraction of the chuck retainer sleeve. In others, the nozzle is simply inserted into the hole of the chuck and rotated until it clicks (with the locking balls installed in the closed grooves of the shank). When removing the tool, the chuck sleeve must be pulled back.
• If a drill is used to drill holes, the drilling depth stop is set to the required hole depth.
• If the rotation speed is not regulated by the trigger, then the required rotation speed of the drill is set using the speed regulator. It is recommended to start with the maximum values, as they provide the maximum tool performance.
• The hammer drill is connected to the network, and the trigger is pressed. In this case, the punch chuck should begin to rotate without impact.
• The accessory is set in the desired position in relation to the material being processed, and the pressure on the tool is not too strong. As a result, the drill or chisel begins to bite into the material.

Rotary hammer maintenance

The rock drill must be kept clean and dry. After work, it is necessary to clean and blow it from dust, wipe the case with a clean damp cloth. The blowing is carried out by the fan of the idling engine. Maintenance of the rock drill also includes replacement of brushes and lubrication of the gearbox at the time specified in the operating instructions.

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For a craftsman working in dwellings where walls and ceilings are made of bricks and concrete, a hammer drill is as necessary as air. How to choose a hammer drill for your home that meets exactly your needs, how different models differ, what to look for when buying - these and many other questions do not have a clear answer. We'll figure out.

A hammer drill is a specialized power tool, the main task of which is to make holes in concrete, brick and similar hard materials. Most models have a mode switch that turns off the spindle rotation and puts the tool in chiseling mode. In this mode, it works like an electric jackhammer.

What is the difference between a drill and a hammer drill

The drill is intended for drilling. Perforator - for drilling. The only common thing in these modes is the rotation of the working nozzle.

The photo shows a drill and drill. The drill rotates and cuts off the material layer with a sharp cutting edge. The characteristic spiral shavings are formed.

A carbide tip with sharp triangular edges is fixed on the tip of the drill. The drill rotates and at the same time a special hammer drill mechanism strikes it. The material crumbles, the resulting crushing products are removed from the hole by the spiral part of the drill.

The differences between a drill and a hammer drill are not only in the used attachments. Internal design differences go deeper. The hammer drill is equipped with a ratchet. When the user presses on the tool while drilling, the ratchet "crushes" the force of this pressing. This simulates "hammer drilling".

Unlike a drill, the hammer drill has a special pneumatic piston, which is driven by an electric motor and strikes the back of the working attachment.

The drill is firmly clamped in the drill chuck. The drill is fixed in special grooves that allow it to move along the longitudinal axis and at the same time transmit the rotation of the spindle.

The video shows the basic structure of the hammer drill.

Let's summarize the differences between a drill and a comparable perforator in the table:

	Drill	Puncher
Power (typical)	300-800 W	550-1500 W
Rotational speed	up to 3000 rpm.	Up to 1500 rpm.
Impact energy	No	2-3.5 J
Types of jobs	drilling, screwdriving	drilling, chiselling, drilling, screwdriving
Rigging	Drills, crowns, bits, etc. (clamped into a chuck)	Drills, chisels, crowns with a special shank. Drills, crowns, etc. (using a special adapter cartridge).
Price	relatively small	big

Rotary hammer specifications

When choosing a hammer drill, the buyer is guided by its technical characteristics. Without understanding their significance for solving specific practical problems, it is impossible to answer the question of how to choose a hammer drill.

Rotary hammer power

The performance of any power tool depends on its power. The larger it is, the faster the tool performs the task assigned to it. In the case of a hammer drill, a more powerful tool makes holes faster.

Rotary hammer power starts at 550 watts. The most popular universal models have a power of 780-850 watts.

Impact energy perforator

This characteristic determines the force of the piston impact on the working nozzle and is measured in joules. More impact energy - better puncher.

The impact energy depends on the power of the electric motor and on the design of the impact mechanism. Rotary hammers from the best manufacturers with a relatively low power give swipe... Second-tier models can be quite powerful, but with a weak impact.

The impact energy of the running models is in the range of 2.4-3.0 J.

Rotary hammer weight

This technical characteristics usually do not pay attention, but in vain. The influence of the mass on the convenience of the hammer drill is very large and ambiguous.

On the one hand, the lighter the tool, the more comfortable and less tiring it is to work with. If you need to drill a couple of holes, you can ignore the weight of the device. It is a different matter if there is a long work ahead. The weight of the device becomes especially noticeable when working from an uncomfortable position: from a stepladder, on the ceiling, in a tight space.

The small weight of the device can be a disadvantage in some situations. When drilling holes in hard materials large diameter recoil becomes noticeable. Nobody canceled Newton's third law. A light hammer drill poorly dampens recoil, the tool bounces off the wall: the impact energy goes not into the wall, but into the operator's hand.

Drill diameter for rotary hammer

This is the most informative integral characteristic of the instrument. The larger the maximum drilling diameter in concrete, the more fully the power of the hammer drill is utilized. Drilling capabilities without hammering are characterized by drilling diameters in wood and metal.

In popular models of hammer drills, the maximum drilling diameter in concrete reaches 24-26 mm, in wood - 32 mm, in steel - 13 mm.

Options and functions

Speed ​​control

As a rule, the speed is regulated by pressing the start button. At low speeds, the nozzle rotates more slowly and the impact energy is low. Some models are equipped with a speed limiter.

Reverse

This function is very useful to free a jammed bit. Structurally, the reverse is realized in two ways: a lever on the trigger (start button) or rotation of the brush assembly.

Which method is better is a moot point. Reverse shifting on the trigger is more common, more familiar and easier to use. Therefore, if you intend to use the hammer drill as a powerful screw or nut driver, definitely choose the model with just such a switch in the direction of rotation of the spindle.

Safety clutch

It is supplied to almost all models of rotary hammers, except for the simplest and cheapest. When the nozzle is jammed (and this happens often in work), the clutch disconnects the spindle of the perforator and the electric drive, protecting the tool from breakage, and the master from injury. It is worth noting that the drill does not have such a device.

Layout

Most rotary hammer models using SDS + bits have a horizontal layout like a traditional drill. The axis of rotation of the electric motor is parallel to the axis of rotation of the spindle.

Some light rock drill models and almost all heavy duty SDS-max models have a design in which the axis of rotation of the electric motor and the drill is perpendicular. The body of the device is L-shaped. This decision is due to some design considerations. Among other things, this makes it easier to work with the tool: the center of gravity shifts forward - less effort is required to hold the hammer drill.

Tool Mounting Standard: SDS-Plus and SDS-Max

There are many types of shanks. But there are only two undercarriages that are used in the overwhelming majority of models of perforators.

Basically, these two standards differ only in size. SDS-Plus shank diameter is 10 mm and is used for small diameter drills up to 30 mm. Larger bits are available with 18 mm SDS-Max shank.

Shanks of different standards differ in configuration. But the function is performed the same: to transfer torque to the working nozzle, while allowing it to move along the axis during operation.

Each hammer drill model is produced for a specific standard. There are adapters, but they are exotic. They are rare on sale.

Cordless rotary hammers

They have appeared on the market quite recently. This was facilitated by progress in the development of batteries with sufficient capacity.

The undoubted advantage of these models is the ability to work in places where it is not possible to connect to the mains or it is inconvenient to carry the power cable.

If we compare battery models with network counterparts, then they: weigh a little more, much more expensive and, in addition, their batteries are short-lived.

Expendable materials

Choosing the right puncher is only half the battle. The hammer drill is unusable without proper equipment.

The choice of equipment is a topic for a separate article, but it cannot be completely circumvented. To get a general idea, watch the video:

Now you know that there are a variety of attachments available for rock drills. Not all of them are equally represented on the market. Therefore, you need to decide in advance which attachments will be used in the work and take care of their purchase.

The quality of rock drill bits directly determines their durability and cost. Rational approach needed here too. For drilling two or three holes, the cheapest drill will be enough. To perform voluminous work, it is more profitable to purchase expensive but durable consumables.

Professional or household?

The division of power tools into "professional" and "household" is very arbitrary. There are manufacturers who classify their products themselves, but there are very few of them.

The main requirement for tools for "professional" use is a large resource and high reliability. Unfortunately, no manufacturer indicates these parameters in the characteristics.

How to choose the right puncher

To buy the best hammer drill, you need to decide for what purpose you need it. This will help to highlight the critical parameters of the future instrument and build on them in your choice.

For home master who needs to make several holes from time to time for hanging shelves or a lamp, an inexpensive amateur model with low power is suitable. It is unlikely that chiselling will be required and large holes will need to be drilled.

Accessories (extra handle, drill stop, drill chuck) and a storage case will be helpful.

For professional use you need a reliable lightweight tool. The working attachments are optional. Their list is very large and craftsmen buy them as needed.

It is important that the rock drill is designed for continuous continuous operation.

Review of several popular models of hammer drill for home

BLACK + DECKER KD 975 KA

The audience of this manufacturer is home craftsmen. Inexpensive beautiful instruments have all the necessary functions: three modes of operation, speed control, reverse.

The impact energy is small - only 1.8 J, but this is quite enough for domestic needs. The 710 W motor handles drilling holes in concrete up to 22 mm in diameter.

Bosch PBH 3000-2 FRE

The popular model of the German manufacturer for a wide range of tasks. With a power consumption of 750 W and an impact energy of 2.8 Joules, it is possible to drill holes in concrete up to 26 mm. Tool weight 3.3 kg.

A special feature of this model is the speed switch.

Makita HR2450

This model of the Japanese manufacturer has gained immense popularity among professional craftsmen due to its extremely low weight. With a mass of only 2.4 kg, the tool has a power of 780 W and develops an impact energy of 2.7 J.

Three modes of operation, adjustable speed by pressing the trigger, reverse. The tool is supplied in a carrying case.

Use the tool as directed, do not overload it. Take breaks during extended work. They are needed not only to let the instrument cool down. The operator is affected by vibrations from the hammer drill. They interfere with blood circulation. Breaks are needed for it to recover.

A few more tricks:

• Lubricate the work bit shank regularly. Use any grease for this.
• Drilling in concrete and similar materials will wear out the drill quickly. The sharp edges of the victorious tip are rounded off. The spiral part also wears out, becomes thinner and worse at removing drilling products from the hole. Together, this reduces work efficiency. Replace worn-out attachments promptly.
• It is easier to drill a large diameter hole in concrete in two passes: first use a smaller drill and then use the correct one.
• Ceramic tiles are drilled without impact. After the drill has passed through it, the hammer drilling mode is activated and the base under the tile is drilled in the usual way.

Conclusion

The huge selection of models on sale makes it difficult to answer the question of how to choose a hammer drill. There are many conflicting considerations to consider. If all of the above information is not clear, try using the exclusion method according to the following algorithm:

1. Determine your budget for purchasing a rock drill. Do not consider models that do not fit into it.
2. Read the reviews and select three or four popular models that have most reviews.
3. Pay close attention to negative reviews. And among them, those that mention specific shortcomings. Weigh how critical these shortcomings are for you. Choose two models.
4. Go to the store and look at these two models, hold them in your hands and evaluate them "by eye".
5. If you haven't chosen now, flip a coin!)))

Happy choice and successful work!

A hammer drill is a power tool used when dismantling building structures made of bricks and concrete, as well as in particularly durable materials. With its help, you can easily remove old tiles from the surface, punch an opening in the wall, make a groove in it for laying a cable, and even tighten a regular screw.

The most famous representative of this type of tool - the Bosch perforator - is equipped with a powerful pneumatic percussion mechanism, which significantly increases the productivity of the device and is equipped with a number of functions that increase the convenience of its operation.

Briefly about the history of the brand

The history of the BOCH brand began in 1886 in Germany. It was then that engineer Robert Bosch opened the country's first electrical engineering workshop. Under this brand, at the beginning of 1932, the world's first electric rock drill was released. In the spring of 1961, the company's engineers patented a new pneumatic principle of operation of this tool. At the end of 1946, the company produced the first, and in 1984, the Bosch hammer drill, which was powered by a battery.

Today the concern is one of the world leaders in the production of quality goods that make human life easier. The company consists of 300 enterprises and more than 13,000 service centers, which are located in 140 states. The range of its products includes, in addition to a variety of power tools, also high-quality household and garden equipment, as well as batteries and saws.

General diagram of the device perforator BOCH

The design of the German brand rotary hammers is represented by a complex, but absolutely thought-out system, all components of which affect the efficiency and productivity of the tool.

1. Patron.

2. Impact mechanism.

3. Safety clutch.

4. Electric motor.

5. Cable entry.

Let's consider the main details and elements that the Bosch perforator is equipped with in more detail.

Keyless chuck SDS

The device is used to attach the working attachments to the unit, prevents them from turning and provides easy replacement. BOCH rock drills are equipped with two types of cartridges:

• SDS-max. For bits with a shank diameter of 18 mm. The chuck is characterized by the presence of 5 grooves (3 open - for insertion; 2 closed - for fixing) and is suitable for mounting a drill with a working diameter of more than 25 mm.
• SDS-plus. For attachment of attachments with a shank diameter of 10 mm. The device is distinguished by the presence of 4 slots (2 open and 2 closed). Such cartridges are equipped with light models of hammer drills, the drills of which can drill holes up to 25 mm.

Impact mechanism

Each Bosch hammer drill is equipped with a powerful impact mechanism that works on the principle of a pneumatic system.

As a result of the reciprocating movements carried out by the piston (2), receiving an impulse from the swinging, or, as it is also called, "drunken" bearing (1), compression is created, which induces the movement of the damper-ram (3) with the striker attached to it hammer (4).

It should be noted that this entire system is driven by a gear motor (5). The result of the operation of the mechanism is the blows that the striker delivers to the end part of the nozzle (drill or blade). In some professional models, the "drunken" bearing of the unit is replaced by a crank mechanism.

Safety clutch

Long-term "Bosch" is a rather rare phenomenon, since the device of its mechanics includes a protective clutch, which stops the rotation of the gears of the tool when the drill gets jammed in the hole. The presence of such a mechanism not only avoids damage to the unit itself, but also ensures the safety of the user working with it.

Electric motor

All German-made tools are equipped with high-quality electric motors of various sizes and power consumption (from 400 to 1500 W). From this diagram of the Bosch rock drills, it can be seen that the engine has a horizontal arrangement. It should be noted that in most powerful professional models, it is located vertically.

Cable gland

All rotary hammers German company equipped with a swivel cable gland, which prevents chafing of the electric cable and increases the comfort of working with the device, increasing its mobility. The structure of this unit allows you to turn the tool at the desired angle, penetrating into the most inaccessible places of the building structure.

Reducer

Many units are equipped with a two-speed gearbox, which allows the shaft speed to be increased without affecting the performance of the unit. If you are thinking of purchasing a tool for your home, then you will be advised by the firm "Bosch" perforator. The price of this unit, however, will be significantly higher than that of its gearless counterparts.

Rotary hammer characteristics

The Bosch hammer drill, like any representative of this type of power tool, has three main characteristics that determine its performance:

• Spindle speed- determines the speed of rotation of the working tool. This indicator affects the efficiency of the unit in the drilling mode and can range from 600 to 2000 rpm. depending on the hammer drill model. Note that powerful professional devices have a lower rotation speed of the working mechanism, since the diameter of their equipment is much higher than that of a household tool.
• Impact energy- depends on the power of the engine, the mass of the striker and the length of its working stroke. It is the main characteristic that determines the performance of the unit, and ranges from 1.2 J for "amateur" models, up to 14.2 J - the impact force, which has the most powerful "Bosch" -perforator. The price of such a professional device, however, exceeds 48,000 rubles.
• Impact frequency- is determined by the number of strikes of the striker on the end face of the working nozzle over a period of time equal to one minute. The speed of drilling holes depends on this characteristic, and together with the impact energy, it determines the performance of the rock drill. For various models, this figure can vary from 1100 to 5500 beats / min.

The technique of the German brand is distinguished by the selection of the optimal ratio of all these parameters, which makes it truly reliable and high quality.

Tool operating modes

A clear advantage that the Bosch perforator has is its ability to work in various modes:

Unit classification

So, we noted that the models of BOCH rock drills have differences in the power of the electric motors, the spindle speed, as well as the frequency and strength of the blows. This allows all aggregates to be divided into the following types:

Depending on the power source, BOCH rotary hammers are divided into electric, powered by a 220 W household power supply, and rechargeable, operating from a lithium-ion or nickel-cadmium battery. Devices of this type are indispensable when working in places remote from power sources, or in de-energized rooms.

Additional aggregate functions

Regardless of the type and brand, most models of this German technology are equipped with a set of functions that increase the productivity and usability of the devices. Almost all units are equipped with:

Thanks to the various capabilities of the devices, any user - from a professional builder to a simple home craftsman - will be able to choose a Bosch perforator that suits his needs. Reviews of this tool are only positive character and speak of its versatility, efficiency and consistently high quality.

From mining to construction. I have come this way puncher. For renovation it began to be used in the 20th century. The very first rock drill was invented a century earlier for drilling hard rock.

Jordan's model was shock, worked mechanically. In 1849, Zhdonaton Coach designed a perforator that works with the power of water.

Then came steam models... The pneumatic device was created in 1857. A Frenchman named Sommelier tried. But the merit of the creation of the electric tool belongs to the engineers of the Bosch company.

Select a puncher, powered by the network, they offered in 1932 at the trade show in Leipzig. In the Bosch model, the impact force is combined with the rotational moment. Modern rock drills work on the same principle.

Types and characteristics of rock drills

The types of punchers that appeared before the electric one have sunk into oblivion. Network-powered tools were out of competition. However, there was a division within the group of electrical models.

In particular, the concepts appeared "Hammer drill for home" and "professional". The first one performs everyday tasks, is weak and small. The first such device was produced by the same Bosch company in 1981. The weight of the instrument was only 2 kilos.

Professional tool versus hammer drill for household work tend to be powerful and heavy. In general, the mass of tools divides them into 3 classes:

• Light. The category includes punchers up to 4 kilograms. Their power is enough, mainly, to poke holes in different surfaces... The impact force does not exceed 2 joules.
• Average. It includes models weighing from 5 to 8 kilos. Their strength is sufficient not only for holes, but also for cleaning uneven concrete, cutting steel gratings. Impact force increases to 7 joules
• Heavy. This class includes perforators weighing more than 8 kilograms. So nothing cares. However, handling a heavy-duty tool requires skill. There are no household models among the models. Perforators of the class hit with a force of about 10-15 joules. There are downsides to such power. The first is high power consumption, and the second is the rapid wear of parts working at the limit.

Perforators are subdivided according to the type of connection. The first electric models were powered by the mains, that is, they were supplied with cords.

There are such tools even now. The models of the group restrict movement and make work dependent on the presence of a nearby current.

More often for work punch choose with battery. The first model with it was designed in 1984. The lithium-ion battery hammer drills are even lighter and more convenient.

However, they have limitations. The composition of the batteries excludes cold operation. Cordless tools are designed to withstand extreme conditions.

In the question, how to choose a puncher helps, in the same way, the classification by a set of functions functions. There are basic and additional ones. The first are:

Drill speed control

Impact function

Drilling function

The list of additional functions of rotary hammers is wider. In particular, the kick off function is useful. You can use the tool like a drill.

By the way, there is also a limitation of the maximum speed of the perforator. The function ensures uninterrupted operation. In this case, a special button will lock the switch in a certain mode.

There are also perforators with vibration damping. The addition "entered" into heavy-weight models easily, but for the first time it entered into light devices only in 2005.

The innovators were the engineers of the same Bosch company. They also introduced many of the following additions to rock drills:

Reverse function, i.e. reverse movement, makes it easy to unscrew the drill

The soft release mechanism eliminates jerks when the device is turned on

Anti-jamming protection in working condition protects the master and the tool itself from injury

The work plane task is named vario-lock

Additional parts in the hammer drill are also available. When choosing a tool, they should pay special attention. This will help to save money not only during the purchase, but also during the operation of the device.

What to look for

Additional brushes may be included with the tool. Their price, coupled with a hammer drill, is lower than with a separate purchase. Therefore, considering 2 competing devices with and without brushes, it is logical to choose the first one.

The set with the hero of the article can include not only spare brushes, but also borax. They are also cheaper in a package with a tool than in a separate sale.

The choice of a hammer drill with an adapter is also justified. This part allows you to install a drill from a conventional drill on the device. The addition makes the hammer drill a versatile tool that will come in handy someday.

It is worth paying attention not only to the configuration and functionality of the instrument, but also to its origin. It is no secret that the factories of most companies are scattered around the world.

Along with Japanese enterprises, Chinese, Vietnamese, and Taiwanese operate. Manufacturers claim that the build quality and parts are identical in different countries. In fact, this is not the case.

Perforators assembled in Japan give odds to others. Professional builders know this and ask for a tool from the Land of the Rising Sun.

Stores are cunning. The first batch is ordered in Japan, and then the goods are shipped from China, showing customers the invoice for the debut purchase. Therefore, it is worth paying attention not only to the document itself, but also to the dates set in it.

Better yet, have a friendly conversation with store managers, leave a number, ask to queue up for an instrument from Japan. Such devices are worth the wait. The price tag is higher than for a batch from the PRC, but it's worth it.

How to choose the right puncher

Deciding which puncher to choose, personal needs must be taken into account. If the device is needed for household needs, rare use, why overpay for power first in the store, and then to the electricity supplier?

This is justified, only if necessary, make wide holes in the walls. Lightweight rock drills are capable of drilling up to 2 centimeters in diameter. The middle-class instrument is capable of 3-4, and heavy devices give holes 5-6 centimeters wide.

If you are about to buy a heavyweight version, look through the DeWALT catalogs. The brand is American. Due to the professional focus of the brand's rotary hammers, they cost from 18,000. For a home craftsman, the costs are hardly justified.

As an alternative to the DeWALT tool, you can choose the punch "Makita"... If you are looking for an inexpensive and high-quality mid-range device, you should turn to Sparky.

Bulgarian company. She became famous for the puncher model BP 400E. The tool is available, at the same time, reliable and equipped with fixing the bit in any position, adjustable speed.

Pay attention to the simplicity of the perforator design, the possibility of its disassembly. Breakage is not excluded. It may occur after the warranty period. The convenient structure of the tool will allow you to disassemble and repair it yourself. Parsing starts from the top node:

Remove the rubber tip

Remove the stopper washer

Remove the spring and ball

Unscrew the screws that fix the case

Remove the cover from the punch handle

Disconnect the stator wires

Remove the brush holder

Disconnect the gearbox from the housing

The switch is removed from the gap between the gearbox and the housing

Place the body vertically and clamp it in a vice

Removing and cleaning the internal parts of the hammer drill

Self-analysis and repair of the hero of the article will allow you to better familiarize yourself with its device, personally answer for the quality of work and, of course, save money.

Perforators prices

The cost of a hammer drill depends on the name of the manufacturer, the place of assembly, the class of the tool and the set of its functions. The minimum price tag is about 7,000 rubles.

The maximum cost for running models reaches 50,000 rubles. You can profitably purchase professional equipment from your hands.

However, the purchase of a used tool carries certain risks, because the state of the hammer drill is difficult to predict.

However, experienced builders diagnose problems with the device on a trial switch-on and checking modes.