How to choose an electric jackhammer?
The jackhammer is an indispensable tool for complex demolition work. By the principle of operation, it is similar to a hammer drill, but it has a greater impact force and productivity when carrying out dismantling work. Demolition hammers are more often used in industry and for professional work, but they can also be used for domestic work. In addition to electrical models, we will briefly review other types of jackhammers and their main features..
Power
By power, jackhammers can be divided into the following subcategories:
- 900 to 1300 watts. A tool with this power rating can dismantle walls made of brick, stone or concrete.
- Over 1300 watts. Demolition hammers with the highest power are suitable for professional work – demolishing asphalt, concrete, frozen soil, demolishing walls and even foundations.
The weight of a jackhammer depends on its power and capabilities. The lightweight tool will be easy to transport, you will be less tired when working, but it will not be able to complete all tasks. A heavy tool can handle anything, but it takes a lot of work.
- Lightweight jackhammers weigh from 6 to 10 kg. They are convenient to use for work at height and inside houses..
- Average weight ranges from 10 to 20 kg. With their help, you can create openings in the walls, destroy partitions, etc..
- Heavy jackhammers (over 20 kg) are not very suitable for household work and are more often used in professional activities, for dismantling monolithic structures, working with large volumes of concrete, granite, etc..
Quality standards
The motor of each Dnipro-M breaker is made in accordance with the internal quality standards:
- The copper winding of the motor from the Japanese manufacturer can withstand up to 200 ° C.
- Three coats of varnish that cover the engine prolongs engine life by 50% and removes heat dissipation.
- Optimum hardness of the steel from which the gearbox is made (HRC 61-63) increases the life of this part.
- Thanks to the use of dustproof rubber bearings, the tool is not afraid of even the most intensive work.
- Reinforced pins for fixing the rig. They are made with the addition of molybdenum.
Chuck type
The jackhammers use the SDS chuck. It can be of several types:
- SDS-HEX. Hex shank that can be used to fit a variety of nozzles – chisels, lances, vanes, ramming nozzles, etc. Has a simple and reliable hex type fastening.
- SDS-MAX. The shank diameter has a diameter of 18 millimeters and 5 grooves. It is very difficult to break this shank, therefore it is suitable for heavy and prolonged work..
Striker attachments
Demolition hammers are capable of working with various types of attachments. They come with many models of the instrument, but you can always purchase the missing one separately. The most popular types of attachments:
- Pick-scrap. It has a pointed end, like a usual crowbar. It is used for demolition work (destruction) with hard materials – concrete, stone, brick, asphalt.
- Scapula. Ideal for removing tiles or finishing materials from surfaces. The blade must be well sharpened to be effective..
- Chisel. With this nozzle, you can destroy reinforcement, frozen soil, and create holes. The chisel is very useful when working with metal structures..
- Pick-tamper. Used for soil compaction, sealing joints and cracks.
Beats per minute
A light and low-power hammer will be able to deliver more blows in a certain time than a heavy and powerful hammer. For example, oversized models of bumpers hit at a speed of about 1000 beats per minute, and a compact tool can develop a speed of 3500 beats / min and higher. More impacts allow for faster destruction of light materials (e.g. bricks), while high impact forces can destroy even the most durable material (e.g. reinforced foundation blocks, floor slabs).
Impact force
The greater the force of the blow, the more the hammer will be able to beat off in one blow. This indicator is related to the volume of work performed, because the speed of work depends on the strength of the blow. Force is measured in joules and is directly proportional to engine power.
The lightest jackhammers are capable of delivering up to 20 J, the average impact force ranges from 20 to 40 J, and the heavy and powerful jackhammers work with a force of 40 J and more..
Catalog
The jackhammer is intended for destruction of concrete and brick foundations, loosening of hard and frozen soil, asphalt concrete pavements. Also suitable for punching grooves, holes and niches in concrete and masonry.
| Parameter name | Value |
| Energy of a single blow; J (kgf.m) | 25 |
| engine’s type | Asynchronous three-phase squirrel-cage rotor |
| Powerfulness | 1.05 kW |
| Voltage | 220 volts 50 Hz |
| Impact frequency; s-1 (bpm) | 19.5 |
| Weight (without cable and working tool) | 21 kg |
The main purpose of the jackhammer is the destruction of foundations (concrete, brick). Can be used for loosening soil (frozen, hard), asphalt concrete pavements. Can be used for punching grooves and niches as well as holes in concrete and masonry.
| Parameters MO-2 | Value |
| Energy of a single blow; J | 39 |
| Compressed air pressure is nominal; (Pa) | 6105 |
| Free air flow; (l / sec) | 22 |
| Hammer weight without tool; (kg) | 8.5 |
| Impact frequency; s-1 (bpm) | 22.5 |
Preparation and order of robots jackhammer MO-3B
Jackhammers received from the factory or warehouse should be disassembled after long-term storage, the parts of the jackhammer must be cleaned of grease and thoroughly rinsed in kerosene and reassembled.
Check the freedom of movement of the striker in the barrel by inverting the hammer in a vertical plane.
Make sure that the intermediate link of the jackhammer is screwed in tight and secured with a stopper..
Ensure free movement of the jackhammer handle.
Pour 30-40 g of industrial oil into the jackhammer through the socket before starting work.
Clean the lance shank from dirt, put a rubber sleeve on the sharp part of the lance, insert the lance into a jackhammer and secure with an end spring, screwing it onto the barrel so that the lock
hit the corresponding groove in the jackhammer barrel.
Blow out the hose with compressed air and connect it to the jackhammer sleeve.
During the operation of the jackhammer, periodically fill in grease through the bushing into the jackhammer to ensure continuous lubrication of its rubbing surfaces.
Lubricate the jackhammer 3-4 times per shift during the first two weeks of operation. A worn-in jackhammer should be lubricated at least 2 times per shift..
Press down the jackhammer while working on the shoulder of the lance.
During breaks in work, store the jackhammer so that it does not get dust, water, etc..
| Parameter name | Value |
| Energy of a single blow; J (kgf.m) | 44 |
| Nominal compressed air pressure; (mpa) | 0.5 |
| Free air flow; (m3 / min) | 1.5 |
| Hammer weight without tool; (kg) | 9 |
| Impact frequency; s-1 (bpm) | 19.5 |
Preparation and order of robots jackhammer MO-2B
Jackhammers received from the factory or warehouse should be disassembled after long-term storage, the parts of the jackhammer must be cleaned of grease and thoroughly rinsed in kerosene and reassembled.
Check the freedom of movement of the striker in the barrel by inverting the hammer in a vertical plane.
Make sure the intermediate link of the jackhammer is screwed in tight and secured with a stopper.
Ensure free movement of the jackhammer handle.
Pour 30-40 g of industrial oil into the jackhammer through the socket before starting work.
Clean the lance shank from dirt, put a rubber sleeve on the sharp part of the lance, insert the lance into a jackhammer and secure with an end spring, screwing it onto the barrel so that the lock
hit the corresponding groove in the jackhammer barrel.
Blow out the hose with compressed air and connect it to the jackhammer sleeve.
During the operation of the jackhammer, periodically fill in grease through the bushing into the jackhammer to ensure continuous lubrication of its rubbing surfaces.
Lubricate the jackhammer 3-4 times per shift during the first two weeks of operation. A worn-in jackhammer should be lubricated at least 2 times per shift..
Press down the jackhammer while working on the shoulder of the lance.
During breaks in work, store the jackhammer so that it does not get dust, water, etc..
| Parameter name | Value |
| Energy of a single blow; J (kgf.m) | 39 |
| Nominal compressed air pressure; (mpa) | 0.5 |
| Free air flow; (m3 / min) | 1.5 |
| Hammer weight without tool; (kg) | 8.5 |
| Impact frequency; s-1 (bpm) | 22.5 |
For impact destruction of structures made of stone, heavy and reinforced concrete, semi-rock, frozen and hard soils, a pneumatic jackhammer with high impact energy of the MOP-4 brand is used, which is an analogue of the MO-4A, MO-4B jackhammer.
Specifications:
| Compressed air pressure is nominal; (kgf / cm2) | five |
| Minimum compressed air pressure; (kgf / cm2) | 3 |
| Energy of a single blow; J (kgf.m) | 55 |
| Impact frequency; s-1 (bpm) | 17.0 |
| Power; (W) not less | 945 |
| Free air flow; (m3 / min) | 1.35 |
| Hammer weight without tool; (kg) | 8.5 |
| Hammer length without tool; (mm) | 580 |
| Sleeve inner diameter; (mm) | 16 |
| Tool shank length; (mm) | 70 |
| Tool shank diameter; (mm) | 24 |
The pneumatic jack hammer of the MOP-2 brand, in terms of its characteristics, is analogous to the pneumatic jack hammer of the MO-2A, MO-2B brands. It is used in the extraction of soft rocks, soft and medium strength coal, asphalt, brick, ice.
Specifications:
Pneumatic jackhammer MOP-2, according to its characteristics, is analogous to a jackhammer
pneumatic brand MO-2A, MO-2B. It is used in the extraction of soft rocks, soft and medium strength coal, asphalt, brick, ice.
Specifications:
Jackhammer. We deliver a crushing blow!
Any serious construction is not complete without the use of appropriate equipment, which includes jackhammers. They are considered an indispensable tool when it is necessary to remove various coatings, as well as to destroy building structures. By the type of drive, the breakers can be gasoline, hydraulic, pneumatic or electric..
The pneumatic breaker is one of the most optimal types of demolition tool. Its main advantage is the complete absence of sparks. Thanks to this advantage, the hammers can be used even in conditions of an increased risk of explosions or fires..
Device
The main structural elements for any type of jackhammers are represented by a striker, a nozzle, a chuck, etc..
Pneumatic piston models are arranged according to the scheme of piston systems based on the shock principle. The main structural elements are represented by a start valve, a striker, represented by a piston, a fitting for a compressor hose, a cup with a ring valve and a valve box, a muffler. In addition, the jackhammers include two springs, a shock absorber, a retaining ring, a handle, a body.
The named parts are combined into several nodes..
- Impact, also called the launcher and air distribution mechanism, includes the firing pin and the barrel.
- Vibration protection of the handle is represented by a glass and sealing sleeves.
- Anti-vibration chisel protection includes arm and spring-loaded bushing.
- Handle body includes body, aerodynamic silencer and trigger.
The shock system has two main functions: supply, distribution and removal of air, converting its energy into work.
Electric models are equipped with such specific components as an electric motor, a gearbox that converts the rotation of the shaft of the latter into a reciprocating movement, a crank mechanism with a piston that provides pressure in the cylinder acting on the firing pin.
Components specific for jackhammers with internal combustion engines include the carburetor, fuel tank, starter, ignition system, and fuel pump. In addition, taking into account the increased vibration of these devices, the handle and control elements are separated from the body by a spring suspension.
There are several options for attachments for various purposes. So, the chisel serves to destroy concrete and metal; scrap or cylinder – brick, concrete, ice; pencil or peak – asphalt, brick, frozen ground; scapula – asphalt, ice; rammer – for soil compaction.
In addition, there are additional accessories for the hammer. It includes the following four attachments. An automatic speed governor, called soft start and idle speed limiter, serves to extend engine life by avoiding overloads and gradual acceleration. The principle of its operation is based on adjusting the speed in accordance with the load. The side handle increases ease of use by promoting proper hold and distribution of forces. The impact frequency adjuster increases tool control by allowing the breaker to be adjusted to suit different hardness materials. The lock of the button ensures that there is no need to constantly hold it down during operation.
The principle of operation of jackhammers is to create reciprocating movements of the striker located in the barrel, which is not kinematically connected with other parts. This is done by different mechanisms depending on the type of hammer..
So, in piston pneumatic models, the air supplied by the hose from the compressor overcomes the resistance of the valve spring when acting on the handle. As a result, the valve moves, opening the opening of the percussion mechanism. Alternately, in the lower and upper parts of the cylinder, a vacuum and excess pressure is created due to the bypass of compressed air between them by the valve system, generating reciprocating movements of the striker.
The operation of the pneumatic turbine hammer is based on the drive of the energy generated by the rotating air of the turbine wheel..
Gas powered hammers are also usually equipped with pneumatic hammers. The piston, by changing the pressure in the cylinder, leads to the movement of the striker piston with the tip attached.
The jackhammer is pneumatic. characteristics, design, principle of operation
Pneumatic manual jackhammer of the MO and MOP series is designed for parsing brickwork, dismantling concrete and reinforced concrete structures, punching openings and holes in brick walls, for breaking coal, mining shale, soft ores, clay. Also, this equipment is used for breaking ice, loosening hard and frozen soil, it is useful in mining and construction work that requires the use of significant impact energy.
Technical characteristics of MO and MOP jackhammers
Hammers of the MO and MOP series operate under the influence of compressed air not exceeding 0.4. 0.55 MPa. Their length without tools, depending on the model, ranges from 510 mm to 720 mm. The energy of a single blow of both series is more than 43 J. The diameters of the MO and MOP handles correspond to 34 and 28 mm. Weight, depending on the model, varies from 7.5 to 10 kg (without tools). The inner diameter of the sleeve is 16. 18 mm. When operating the equipment, a lance, a hatchet, a shovel or other tool that meets the working conditions is used. Tool shank dimensions: length. 70 mm, dia. 24 mm. In the manufacture of jackhammers MO and MOP, the requirements of GOST are strictly observed.
Choice
First of all, it should be noted that jackhammers are mainly professional equipment. This is due to the lack of demand for them for household and economic purposes, as well as the high cost.
Therefore, the main factor in choosing a jackhammer is the purpose, that is, the amount and nature of the planned work. This determines the required parameters and functions of the device. In addition, it is impractical to purchase such a device for one-time work..
There are several basic parameters of jackhammers.
- Weight determines the ability to keep the device suspended. So, models weighing up to 6 kg are relevant for high-altitude work or cramped conditions. Hammers up to 10 kg can be held horizontally when carrying out horizontal work on dismantling walls and making holes. Heavier hammers can work vertically with foundations, soil, etc..
- The force of the impact is equivalent to the amount of material chipped off for it. Thus, the efficiency of the tool and the speed of work directly depend on this indicator. It can be from 2.8 to 63 J.
- The impact frequency, reflecting their number per unit of time, also determines the speed of work, but is inversely related to the previous parameter. That is, with an increase in the force of blows, their frequency decreases. So, for light models, this characteristic can be up to 3500, while for heavy models – from 1100.
- Power determines the penetration capacity of the jackhammer and the duration of the working cycle. It is 0.5–2 kW. For finishing works, 1.2 kW is enough. To destroy a concrete or brick wall, 1.6 kW is required. The greatest capacity is required for the dismantling of the road surface.
The given technical characteristics of jackhammers are largely determined by the type of drive. That is, one of the classifications is of great importance. To understand how to choose a model, you need to know the features of the types allocated to it..
Pneumatic devices, in comparison with electric and ICE hammers, due to their simpler design, are considered more reliable and durable at a significantly lower cost. In addition, they have the smallest mass, ranging from 1.5 to 16 kg. In addition, these hammers are very productive. Finally, these models are suitable for work in conditions of high humidity and near flammable substances. The main disadvantage is that it is tied to a power source in the form of a compressor, which will have to be purchased separately for a considerable price. Moreover, it is necessary to select this device based on the parameters of the hammer. The main characteristics are volume and working pressure. Compressor parameters determine the duration of operation.
Electric breakers are tied to an energy source, just like pneumatic ones. In contrast, such devices cannot be used near flammable substances due to the sparking of the motor during operation. They are also not suitable for high humidity conditions. Despite this, they are a very common type of jackhammers. This is primarily due to the significantly higher efficiency in comparison with pneumatic jackhammers and models with internal combustion engines. In addition, they are distinguished by the best environmental performance, the lowest level of vibration and noise. Despite the external power source, it is not available as additional equipment, it provides unlimited operation time and ease of connection. Finally, with a more complex design, they are easy to maintain. In addition to the main parameters, the engine power is of great importance for these hammer models. For domestic purposes, jackhammers of this type are most often used..
In addition, there are battery options that combine the above positive qualities of electric hammers with the autonomy of gasoline ones. Still, they are not so mobile, since the duration of operation is determined by the capacity of the battery, which requires further charging..
ICE models are the most mobile. Moreover, they are characterized by a high level of noise, the presence of toxic emissions. In addition, instead of being tied to an energy source, they require a supply of fuel, the amount of which determines the duration of operation. Finally, ICE jackhammers are the most difficult to maintain: they require draining fuel residues, cleaning filters, etc..
In addition, the advantageous working position of the breaker is of great importance..
Horizontal modifications are distinguished by their low weight and the presence of appropriate handles: holding the rear and controlling the front.
Vertical breakers are heavier and have side handles.
Finally, the manufacturer is of considerable importance when choosing. There are a number of brands known for their high quality products. The manufacturers that produce the best jackhammers include Bosch, Sparky, AEG, Makita, DeWALT, Hitachi, Metabo, Milwaukee.
Design and principle of operation of a pneumatic breaker
The hammer is a piston pneumatic air-distributing valve driven hammer driven by compressed air. Equipped with an engine with free piston movement and is subdivided according to the principle of the applied air distribution system, which is carried out using plate valves or tubular spools.
It consists of an air-distribution-shock mechanism and a handle with a starting device assembled in it. The air distribution-percussion mechanism supplies compressed air to the barrel cylinder in turn into the chambers of the forward and reverse strokes of the striker and discharges the exhaust air into the atmosphere, converting the energy of the compressed air into the mechanical work of the movable percussion mechanism.
Demolition hammer part 1
To prevent self-unscrewing of the threaded connection of the link and the barrel when aligning the barrel hole with the slots of the intermediate link, a retainer is installed, held from falling out by a retaining ring. The circlip has an opening for the exhaust air. The Belleville spring is used to press the air distribution unit against the barrel end. The hose supplying compressed air is connected with a union nut and a nipple.
Additional fixation of the lance is provided by an annular spring wound on the hammer barrel. The start is carried out by pressing the handle on the valve. The pressing force must overcome the resistance of the spring, shock absorber and valve supported by compressed air. For the initial start-up, it is necessary to apply a force up to 120 N, the value depends on the air pressure. Switches off automatically when the force is removed from the handle.
Pressing the handle, the valve moves to the right and opens the hole associated with the annular chamber of the valve distribution. With the help of a valve distribution, a striker and a barrel, compressed air is directed alternately into the chambers of the direct and reverse stroke of the striker, forcing it to reciprocate, periodically striking the shank of the working executive tool.
lever; 2. shock absorber; 3. valve; 4. plug; 5. box; 6. valve; 7. retainer; 8. retaining ring; 9. barrel; 10. drummer; 11.foot; 12.nipple
The main components of the hammer are the air distribution percussion mechanism, the handle with the starting device, as well as the silencer cover. Concrete breakers are designed in a similar way, their principle of operation is the same. The air distribution percussion mechanism is used to convert the action of compressed air into mechanical energy, which ensures the operation of the striker. Structurally, it consists of the following components:
- trunk with axle box;
- jumpers;
- drummer;
- valve;
- valve core and cover;
- pin.
The drummer in the barrel should move freely, without difficulty. The starting device includes:
- lever;
- shock absorber;
- intermediate;
- retainer, retaining ring;
- plug, valve, spring;
- box;
- footwear;
- nipple and union nut.
A special latch with a safety retaining ring prevents spontaneous unwinding of the threaded barrel and intermediate link components. The purpose of the valve cover. pressing the air distributor to the end of the barrel. The sleeve is used to supply compressed air to the hammer; it is connected using a nipple and a union nut. End spring with rubber grommet helps to hold the tool. peaks, blades, etc. from falling out of the product shank. The intermediate link must be screwed tightly and secured with a stopper.
The MO and MOP jackhammers have built-in vibration protection, as well as noise mufflers, which allows the equipment to be operated without harm to human health. Product safety is confirmed by the Russian Gosstandart certificate of conformity.
We carry out diagnostics, maintenance and repair of pneumatic jackhammers MO-2K, MO-3B, MOP-2; 3; 4.
Air hammer classification
There are many pneumatic breakers from different manufacturers on the construction tool market today. Therefore, it will be quite difficult for a non-professional to figure out which hammers are better in terms of their parameters, and what should be taken into account when choosing such a tool..
The jackhammer is divided into 2 main types:
- volumetric – the operation of the device is driven by the rapid expansion of air in a special chamber;
- turbine – they work due to the energy generated by the rotation of the blades of an air turbine.
All jackhammers, according to their technical characteristics, are classified into four typical sizes in terms of energy and frequency of blows per second:
- The first type – the impact energy reaches up to 30 J, and the impact frequency is up to 45 Hz. The tool is used for the removal, destruction of materials (clay, brick, asphalt) with medium strength, as well as when working in confined conditions.
- The second type – impact energy – up to 40 J, impact frequency up to 34 Hz. The devices are used for general construction work.
- The third type is impact energy up to 45 J, frequency up to 20 Hz. It is used when working with strong materials with the direction of impacts vertically downwards.
- The fourth type is energy over 50 J, frequency up to 24 Hz. Carrying out work with materials of a high degree of strength.
In addition to the impact energy, the pneumatic hammer is conventionally divided according to the average weight of the tool:
- from 5 to 6 kg – light – carrying out high-rise, finishing and other works, which, by their specificity, do not provide for large-scale destruction. They are often used in everyday life. Such a tool has a relatively low power level;
- from 6 to 10 kg – medium – preferred for horizontal work. This weight allows you to hold the tool for a sufficiently long time while observing a certain direction of work. Therefore, the device is widely used in construction and repair work;
- within 15 kg – heavy. Such pneumatic hammers are intended only for heavy work, most often in industry..
The power of the blow is an indicator related to the amount of material beaten off per 1 blow. It can vary from 2 to 63 J. It is believed that the higher the impact force, the higher the speed and degree of efficiency of the device..
Impact frequency – this criterion displays the number of impacts per unit of time, that is, the speed of the equipment. The greater the force of the blows, the lower their frequency will be. Often, heavy hammers have 1100 blows per minute and lighter tools 3500.
To ensure the efficient functioning of the pneumatic breaker and to maintain a high level of its performance, you should also pay attention to the characteristics of the compressor used: working pressure and compressed air volume.
JACKHAMMER
JACKHAMMER
A tool such as a jackhammer is necessary for workers of multiple construction trades. Using this tool, you can make holes in ceilings from any material or in walls, dismantle building structures and foundations, remove concrete or asphalt, crush rocks and other types of work.
Also, a jackhammer can be used when working to expand existing window and door openings, the formation of new openings. This tool will become an irreplaceable assistant when it is necessary to destroy walls, monolithic structures, steps, foundations and partitions..
Demolition hammer models have a vibration damping system, as well as a super-reliable impact mechanism. The design is often compact and has a latching switch.
Thus, by means of the vibration system, the worker is provided with comfort even with fairly frequent use of the jackhammer. It is also possible to set different frequency of impacts in order to ensure the optimal level of performance..
The models are equipped with constant electronics and a service display, as well as a standby indicator, which also significantly increases the level of comfort of work.
This tool must be powerful enough, but at the same time have an acceptable weight to carry out work, for example, at high altitudes..
Demolition work is of great importance in the construction industry. The main hand tool for performing them is a sledgehammer. For large-scale works, an automated mechanism is used, represented by a weight driven by a crane. There is an intermediate version of the mechanized device, suitable for carrying out dismantling works of various sizes. This is a jackhammer.
Several parameters are used to classify the devices under consideration..
By performance, jackhammers are differentiated into three types.
Lightweight options are designed for household work. They are capable of crushing plaster, tiles, etc., which makes them suitable for home renovations. The mass of such mini jackhammers is 5-6 kg.
Medium power units are suitable for asphalt and are therefore used for some construction work. Weight from 6 to 10 kg provides the possibility of long-term horizontal holding.
In industry and in the construction of buildings, high-power jackhammers weighing 15-30 kg are used.
However, mass is an indirect indicator of performance. There is a classification close to the above, based on other, more significant parameters. It also includes four types.
The first includes jackhammers with an impact energy of up to 30 J and a frequency of up to 45 Hz. They are suitable for medium-strength materials such as asphalt, brick, clay, and work in confined spaces.
The second type is represented by options with an impact energy of 40 J and a frequency of 34 Hz, used in general construction works..
The third type includes models with an impact energy of up to 45 J and a frequency of up to 20 Hz. They are used for work in vertical direction of impacts with durable materials.
The fourth type is represented by hammers with an impact energy of more than 50 J and a frequency of up to 24 Hz. Such devices are used for high-strength materials.
Based on the power source, there are four types of jackhammers..
Pneumatic devices are the most common type. The power source for them is a compressor. The principle of operation is based on the pressure of compressed air molecules on the chisel. This equipment is suitable for the destruction of any structure made of brick and concrete. For household options, a power of 5 J is required, and for industrial models this parameter is from 10 to 100 J. This is enough to destroy asphalt, stone, concrete, etc..
Electric hammers are powered from the mains. The principle of their functioning consists in bringing the striker by means of the rotary element of the electric motor. Performance parameters are up to 1700 W of power, 45 J of impact energy and 2000 beats per minute of frequency. Therefore, these jackhammer options have a high impact power, but are not suitable for cutting and drilling materials..
Gasoline devices are driven by an internal combustion engine, which has no valves and no shaft. With low power, the main advantage of these options is autonomy, that is, the ability to use it anywhere. This is due to the absence of the need to connect to an energy source. The duration of operation is determined only by the amount of fuel. In addition, jackhammers of this type are considered safer in comparison with analogues. However, they are distinguished by a high level of noise. These models are used in the mining industry, with the destruction of concrete, asphalt, frozen soil.
Hydraulic hammers use a variety of power sources. They are usually used in rescue operations..
Electric jackhammer
Jackhammer petrol
Pneumatic jackhammer
Pneumatic hammers are also divided into two types according to the principle of operation..
Volumetric devices are driven by rapidly expanding air in the chamber.
The operation of the turbine variants is provided by the energy generated by the rotation of the turbine..
The simplest classification of jackhammers on the basis of a set of basic parameters differentiates them into professional and household.
It should be noted that there are tools similar in design and purpose to jackhammers..
Concrete breakers are distinguished by their large dimensions, weight and productivity. These devices are designed for vertical and inclined work with concrete slabs, rocks, asphalt pavement, frozen soils. Rotary hammers are usually more compact than jackhammers or close in size, are more accurate and capable of performing the functions of a drill and screwdriver with speed and reverse control. This versatility makes them much better suited for domestic work. Thus, the instruction manual for the PE-2520M indicates the possibility of its use as both a jackhammer and a drill..
The main structural elements for any type of jackhammers are represented by a striker, a nozzle, a chuck, etc..
Pneumatic piston models are arranged according to the scheme of piston systems based on the shock principle. The main structural elements are represented by a start valve, a striker, represented by a piston, a fitting for a compressor hose, a cup with a ring valve and a valve box, a muffler. In addition, the jackhammers include two springs, a shock absorber, a retaining ring, a handle, a body.
The named parts are combined into several nodes..
Impact, also called the launcher and air distribution mechanism, includes the firing pin and the barrel.
Vibration protection of the handle is represented by a glass and sealing sleeves.
Anti-vibration chisel protection includes arm and spring-loaded bushing.
Preparing Your Jack Hammer for Use
Handle body includes body, aerodynamic silencer and trigger.
The shock system has two main functions: supply, distribution and removal of air, converting its energy into work.
Jackhammer device
Electric models are equipped with such specific components as an electric motor, a gearbox that converts the rotation of the shaft of the latter into a reciprocating movement, a crank mechanism with a piston that provides pressure in the cylinder acting on the firing pin.
Components specific for jackhammers with internal combustion engines include the carburetor, fuel tank, starter, ignition system, and fuel pump. In addition, taking into account the increased vibration of these devices, the handle and control elements are separated from the body by a spring suspension.
There are several options for attachments for various purposes. So, the chisel serves to destroy concrete and metal; scrap or cylinder – brick, concrete, ice; pencil or peak – asphalt, brick, frozen ground; scapula – asphalt, ice; rammer – for soil compaction.
In addition, there are additional accessories for the hammer. It includes the following four attachments. An automatic speed governor, called soft start and idle speed limiter, serves to extend engine life by avoiding overloads and gradual acceleration. The principle of its operation is based on adjusting the speed in accordance with the load. The side handle increases ease of use by promoting proper hold and distribution of forces. The impact frequency adjuster increases tool control by allowing the breaker to be adjusted to suit different hardness materials. The lock of the button ensures that there is no need to constantly hold it down during operation.
The principle of operation of jackhammers is to create reciprocating movements of the striker located in the barrel, which is not kinematically connected with other parts. This is done by different mechanisms depending on the type of hammer..
So, in piston pneumatic models, the air supplied by the hose from the compressor overcomes the resistance of the valve spring when acting on the handle. As a result, the valve moves, opening the opening of the percussion mechanism. Alternately, in the lower and upper parts of the cylinder, a vacuum and excess pressure is created due to the bypass of compressed air between them by the valve system, generating reciprocating movements of the striker.
Jackhammer drawing
The operation of the pneumatic turbine hammer is based on the drive of the energy generated by the rotating air of the turbine wheel..
Gas powered hammers are also usually equipped with pneumatic hammers. The piston, by changing the pressure in the cylinder, leads to the movement of the striker piston with the tip attached.
First of all, it should be noted that jackhammers are mainly professional equipment. This is due to the lack of demand for them for household and economic purposes, as well as the high cost.
Therefore, the main factor in choosing a jackhammer is the purpose, that is, the amount and nature of the planned work. This determines the required parameters and functions of the device. In addition, it is impractical to purchase such a device for one-time work..
There are several basic parameters of jackhammers.
Weight determines the ability to keep the device suspended. So, models weighing up to 6 kg are relevant for high-altitude work or cramped conditions. Hammers up to 10 kg can be held horizontally when carrying out horizontal work on dismantling walls and making holes. Heavier hammers can work vertically with foundations, soil, etc..
The force of the impact is equivalent to the amount of material chipped off for it. Thus, the efficiency of the tool and the speed of work directly depend on this indicator. It can be from 2.8 to 63 J.
The impact frequency, reflecting their number per unit of time, also determines the speed of work, but is inversely related to the previous parameter. That is, with an increase in the force of blows, their frequency decreases. So, for light models, this characteristic can be up to 3500, while for heavy models – from 1100.
Power determines the penetration capacity of the jackhammer and the duration of the working cycle. It is 0.5–2 kW. For finishing works, 1.2 kW is enough. To destroy a concrete or brick wall, 1.6 kW is required. The greatest capacity is required for the dismantling of the road surface.
The given technical characteristics of jackhammers are largely determined by the type of drive. That is, one of the classifications is of great importance. To understand how to choose a model, you need to know the features of the types allocated to it..
Pneumatic devices, in comparison with electric and ICE hammers, due to their simpler design, are considered more reliable and durable at a significantly lower cost. In addition, they have the smallest mass, ranging from 1.5 to 16 kg. In addition, these hammers are very productive. Finally, these models are suitable for work in conditions of high humidity and near flammable substances. The main disadvantage is that it is tied to a power source in the form of a compressor, which will have to be purchased separately for a considerable price. Moreover, it is necessary to select this device based on the parameters of the hammer. The main characteristics are volume and working pressure. Compressor parameters determine the duration of operation.
Electric breakers are tied to an energy source, just like pneumatic ones. In contrast, such devices cannot be used near flammable substances due to the sparking of the motor during operation. They are also not suitable for high humidity conditions. Despite this, they are a very common type of jackhammers. This is primarily due to the significantly higher efficiency in comparison with pneumatic jackhammers and models with internal combustion engines. In addition, they are distinguished by the best environmental performance, the lowest level of vibration and noise. Despite the external power source, it is not available as additional equipment, it provides unlimited operation time and ease of connection. Finally, with a more complex design, they are easy to maintain. In addition to the main parameters, the engine power is of great importance for these hammer models. For domestic purposes, jackhammers of this type are most often used..
In addition, there are battery options that combine the above positive qualities of electric hammers with the autonomy of gasoline ones. Still, they are not so mobile, since the duration of operation is determined by the capacity of the battery, which requires further charging..
ICE models are the most mobile. Moreover, they are characterized by a high level of noise, the presence of toxic emissions. In addition, instead of being tied to an energy source, they require a supply of fuel, the amount of which determines the duration of operation. Finally, ICE jackhammers are the most difficult to maintain: they require draining fuel residues, cleaning filters, etc..
Demolition hammer characteristics
In addition, the advantageous working position of the breaker is of great importance..
Horizontal modifications are distinguished by their low weight and the presence of appropriate handles: holding the rear and controlling the front.
Vertical breakers are heavier and have side handles.
Finally, the manufacturer is of considerable importance when choosing. There are a number of brands known for their high quality products. The manufacturers that produce the best jackhammers include Bosch, Sparky, AEG, Makita, DeWALT, Hitachi, Metabo, Milwaukee.
The main areas of use of jackhammers include construction and mining.
In the first case, they serve to dismantle structures during redevelopment and demolition, cutting metal, removing concrete and asphalt road surfaces, ramming soils in hard-to-reach places, arranging wells, loosening frozen soils, making holes and niches, removing ice.
In the mining industry, jackhammers are used when more powerful equipment is not available. So, the conditions of use in mines, consisting primarily in limited space, determine the need for compact tools. In addition, workings are processed along the entire radius. Therefore, a lightweight hammer is required that can be used upside down.
The scope of application is largely determined by the type of device: in what conditions and under what atmosphere to work, etc..
Some of the features of the operation of jackhammers were noted above. Regardless of the type of device, general rules are highlighted. Firstly, before starting work, the tip of the nozzle should be lubricated with any type of plastic grease such as lithol and grease. Secondly, it is recommended to add grease to the barrel of the tool when working from two times per shift in order to extend its service life. In this case, various oils are used for a jackhammer in accordance with the instructions. Some recommend I20A, others – gear oil 15W-40, etc. Thirdly, you should not allow dirt and water to get into the device, rinse the cartridge from lubrication with gasoline at the end of the work, after removing the nozzle. Fourthly, it is necessary to follow the provisions of the instructions, using the hammer as intended and without overloading. Fifth, once a month it is recommended to carry out maintenance, which includes complete disassembly and flushing of all parts with gasoline or kerosene..
Work carried out by a jackhammer
Demolition hammer in construction
In addition, there are specific features of the operation of each type of jackhammers..
So, a pneumatic hammer after a long break before starting work is recommended to be disassembled and washed in detail with gasoline. Then, within two weeks, the barrel should be lubricated with pneumatic oil 3-4 times per shift..
For electric models, timely replacement of brushes is required. In addition, technological breaks of 10-15 minutes should be taken at intervals of 25 minutes to avoid overload.
On gasoline jackhammers, it is necessary to pre-prepare a fuel mixture, including gasoline and oil of a certain concentration. The instructions indicate which oil to pour into the jackhammer, in what quantity, etc. Moreover, it is required to completely develop the fuel mixture or drain the residues. This avoids contamination of the battery with oil film.
Each type of device under consideration is characterized by specific faults..
On pneumatic versions, the channels are most often clogged. This is solved by detailed washing with kerosene. Their clogging with ice is possible, which occurs when the temperature at the outlet of the compressed air drops sharply. This is eliminated by thawing..
The main reason for breakdowns of electric jackhammers is electrical circuit breakdowns, which consist in breaking the button and erasing the brushes transmitting electricity to the motor. Replacing the brushes is easy. Repairing the button is more difficult due to the fact that in many cases it is necessary to disassemble the entire case, however, on modern models, taking into account this feature, it is equipped with a separate cover to simplify replacement.
For models with internal combustion engines, a clogged carburetor is characteristic. Finally, on any jackhammers, there is a jamming of the nozzle in the chuck. In this case, dismantle the cartridge and squeeze out the nozzle, after which the cartridge is washed from lubrication with kerosene..