The problem of choosing a forklift truck involves primarily a comprehensive analysis of its technical and operational parameters: the service life, technical parameters, safety and operating conditions, price, as well as a number of other factors. The most important technical parameters of the loader are its carrying capacity, lifting height, power and drive type (internal combustion engine (ICE) - diesel, gas, gasoline, electric engine). The secondary parameters are the type of the loader, transmission (hydrostatic, hydrodynamic, mechanical), brakes, tires (pneumatic, solid, bandage), as well as its overall dimensions, fork length, the number of sections of the hydraulic valve.
There are up to 60 technical parameters of the forklift. Their number varies depending on the type of power unit, the design of various assemblies, the standards of the manufacturer, the country of production, etc. Let us briefly consider the main factors that should be guided by a particular type of loader.
The specific operating conditions, i.e. whether the machine will work indoors or outdoors, whether it will have to leave the room for the open space, especially during the cold season, etc., will determine what type of engine your forklift needs. As you know, the engine is the most important unit and it is characterized by a number of parameters, the main of which are noise level, economy, compliance with environmental standards, engine volume, rated power output and rated torque.
As a rule, the forklifts with diesel or gasoline engine are used on the open grounds, but sometimes they are also used in well-ventilated premises with high ceilings. Diesel forklifts can be equipped with catalytic exhaust aftertreatment. However, these devices break down quickly if low-quality fuel is used. But these catalytic converters are rather expensive at $1000 ... 1500.
The electric loaders are powered by the traction battery, and they are used indoors more often. These machines are more popular in European and American countries, because electricity is a cleaner energy carrier, than liquid fuel or gas. This is due to their stringent environmental and ecological standards.
Lately, asynchronous AC motors are replacing DC motors. In asynchronous drives, the direct current stored in the battery is converted to alternating current and only then is fed to the motor winding. These designs do not have a brush assembly, which means there is no need to change them. Another advantage of the asynchronous motor is the hermeticity of the design, eliminating the possibility of moisture, dirt and dust entering the motor. Technics with such a drive can work in the most severe conditions. Automatic speed regulation and a small number of rubbing parts reduce engine wear and tear. This power unit has higher power and lower power consumption; in addition, the capability of automatic braking when releasing the accelerator pedal, both on horizontal and inclined planes, eliminates spontaneous machine rollback.
Speed and torque can be adjusted independently of each other, allowing smooth acceleration and braking of the electric motor using only the "gas pedal" pedal. Nowadays, all leading forklift manufacturers produce machines with AC drive. It is assumed that the role of such units in the near future will increase even more: according to various estimates the share of regulated AC drives by 2010 will amount to 66 to 97% of the total market of regulated drives.
There are forklift models with the so-called diesel-electric drive, which combine the advantages of both types of engines. In these machines, a generator connected to the diesel engine generates current and feeds the traction motor through an electronic speed and power control unit.
Another option for a forklift with an internal combustion engine is a gasoline forklift with a gas system installed on it. Usually these are models of small lifting capacity - up to 5.0 tons. Gasoline forklifts use household 30- or 50-liter gas cylinders. It is enough to have 4 ... 8 cylinders for each forklift to take them to refuel no more than once a week. According to some estimates, they make up about 50% of the world forklift truck market.
When working in hot or cold climates the forklifts can be equipped with air conditioners or heaters. Working in seaports, ship holds (depreciation rate is 3 years instead of the usual 6 years), in cold stores, metallurgical plants, in conditions of high fire and explosion are considered to be especially harsh conditions. For these conditions, you should choose a truck with a reliable engine and protected components. Electrical wires and contacts, especially on the electric forklift, should be protected from corrosion, dust, high temperatures. Some companies produce forklifts in special designs, such as for working at low temperatures, for fish processing plants, in an explosion-proof design.
An important factor in choosing the truck is the intended route of transportation: the length of the route, the presence of climbs and turns, ramps, downgrades, the width of the passage, the size of the racks, the presence of foreign objects over the aisle (lamps, metal structures). When working with small loads, in narrow aisles and at low speeds, maneuverable three-legged electric forklifts are usually used. If the work is carried out at higher speeds, with heavy loads, four-legged forklifts are used, characterized by greater stability. Analysis of the route in conjunction with the conditions of work prompts, whether the machine needs a reverse signal, additional lighting equipment and other options, which are usually paid extra.
The main working body of the loader is a fork. The fact is that in closed warehouses for handling most of the cargo weighing 0.5 ... 3.2 tons, pallets (pallets) are used as containers. Thus, the practice of loading and unloading has led to the unification of cargo sizes.
Fork length usually depends on the type of pallets you have to work with and ranges from 730 to 1100 mm. Choosing this working equipment, you should keep in mind not only the size of the pallets, but also the fact that the longer the length of the forks, the greater should be the width for the working passage of the forklift.
In addition to forklifts with front forks designed to handle pallets, there are forklifts with side forks. They, as a rule, are used for long cargo - lumber, rolled metal, etc. At the open areas of terminals the forklifts are used for handling 20- and 40-foot universal containers. Here, in addition to forklift models with a loader-mast, they use forklifts with a telescopic boom and top loading grip of spreader type.
There is a large number of interchangeable attachments for cargo handling, expanding the scope of the loaders and increasing the efficiency of using the machine. Load carriers fit both forklifts and electric forklifts.
Mounting them on the forklift carriage takes minutes.
Of the many interchangeable equipment, the most common:
This factor is decisive in selecting the type of hoist. On a standard type mast the load is well visible; on such a mast the forks are lifted to a height of 3300 mm, which allows stacking the load on the third tier of racks. For lifting to a higher height - up to 7.0...7.5 m - three-section masts are used. The lifting mast is equipped with a forward-backward tilt function for convenient positioning of the load.
In cramped conditions, such as in railcars, in universal 20- or 40-foot containers or the back of a truck, stacking in two tiers can be used only if the forklift has the function of the so-called special free lift - lifting the forks without lifting the forklift itself, i.e. without increasing the "construction" height of the machine. Not all types of forklifts are equipped with this function. However, if the forklift handles two pallets lying on top of each other at the same time instead of separately, this function, which usually costs extra money, is not necessary.
Concrete, asphalt, metal tiles or special materials are used as flooring. Not only is it important for the forklift to have a floor, but also its condition. If the floor in the potholes, roughness, rapids, it is better to use the models of equipment on pneumatic tires - they better absorb the shocks and bumps and in addition are cheap. If the loader works in conditions where there can be on the floor metal chips, pieces of metal, wire, nails, broken glass, etc., it's better to use equipment on bandage tires, which, however, very rigid and poor protection from vibration. The intermediate and the best option in many cases is the use of so-called solid tires or tires made of "super elastic". Because they are quite elastic but not filled with air, they cannot be punctured.
If the forklift has to work on construction sites, in the countryside, at logging companies, sometimes in the absence of roads, it is better to choose special "off-road" models on pneumatic tires with increased traction and a high ground clearance. There are a large number of models of such loaders, equipped with a loader in the form of a telescopic boom.
The loaders can be used in one, two or three shifts. At intensive work it is necessary to pay attention to such characteristics of the loader as its maneuverability (minimal turning radius, dimensions of movement (with and without load), lifting-lowering speed, average productivity per shift. It should not be forgotten that with the increasing intensity of forklift operation the expenses for fuel and lubricants also increase, sometimes twofold. When choosing electric forklifts, you should think about the purchase of replacement batteries and their timely recharging.
When choosing a forklift model, it is important to consider the operational factors that determine the safety of work. The relatively large weight of the machine and the cargo, work in confined spaces, high speed of movement and lifting, shifting of the center of gravity when lifting-lowering the load and high maneuverability, the constant movement back and forth increases the probability of injury. According to statistics, the most frequent accidents are caused by the side tipping of the truck when turning at high speed, as well as by dropping a load or part of a load on the roof of the cabin. That's why most models are equipped with FOPS/ROPS cabs and safety belts. In summer, when the cab windows are removed, the buggy-type safety doors are used.
Driving a forklift requires special attention. So the driver does not get tired, the manufacturers pay much attention to workplace ergonomics: reduce noise and vibration, provide the ability to adjust the seat and steering column for the weight and growth of the driver, improve visibility through improved design loader, make the cabin glazing circular, etc. The latest generation models use the most modern features to facilitate the control: LCD display with information display about the parameters of the loader and faults, diagnostic system, joystick control, unauthorized access control system.
The price factor in choosing the loader, as well as any other equipment, plays an important, sometimes paramount role. Choosing the loader they are often guided by the principle of cost minimization. Usually they talk about the price-quality ratio. To quantify this ratio, in our view, it is advisable to choose such an evaluation parameter as the cost per motor-hour. This indicator includes not only the purchase price, but also the cost of maintenance and repair, energy and fuel, forklift service life. The best producers declare service life of 16 ... 20 thousand moto-hours (i.e. 10 ... 12 years in one-shift work), but in practice we can meet models with 40 ... 45 thousand moto-hours.
Domestic consumers, most of whom are motorists, prefer lift trucks as more "understandable" equipment. Indeed, low operating costs and high environmental friendliness of electric forklifts turn out to be certain inconveniences: you need chargers, places for charging batteries with exhaust and an appropriate specialist - a battery technician. Nevertheless, the calculation of the cost per hour shows that such trucks are more often cost-effective.
The higher the intensity of operation, the more reliable and easy to use a truck should be. For the three-shift mode only new imported equipment is suitable or it is necessary to create park of loaders of larger number. If the truck is engaged no more than one hour a day, it is possible to purchase a second hand truck of domestic manufacture. In this case, however, there is a high probability that it can go out of order, and the relative cheapness of the machine does not compensate frequent purchases of spare parts. And if you have decided to buy a used machine, take the advice of experts: do not buy a model with more than 10 thousand motor-hours worked.
There are up to 60 technical parameters of the forklift. Their number varies depending on the type of power unit, the design of various assemblies, the standards of the manufacturer, the country of production, etc. Let us briefly consider the main factors that should be guided by a particular type of loader.
Forklift Operating Conditions
The specific operating conditions, i.e. whether the machine will work indoors or outdoors, whether it will have to leave the room for the open space, especially during the cold season, etc., will determine what type of engine your forklift needs. As you know, the engine is the most important unit and it is characterized by a number of parameters, the main of which are noise level, economy, compliance with environmental standards, engine volume, rated power output and rated torque.
As a rule, the forklifts with diesel or gasoline engine are used on the open grounds, but sometimes they are also used in well-ventilated premises with high ceilings. Diesel forklifts can be equipped with catalytic exhaust aftertreatment. However, these devices break down quickly if low-quality fuel is used. But these catalytic converters are rather expensive at $1000 ... 1500.
The electric loaders are powered by the traction battery, and they are used indoors more often. These machines are more popular in European and American countries, because electricity is a cleaner energy carrier, than liquid fuel or gas. This is due to their stringent environmental and ecological standards.
Lately, asynchronous AC motors are replacing DC motors. In asynchronous drives, the direct current stored in the battery is converted to alternating current and only then is fed to the motor winding. These designs do not have a brush assembly, which means there is no need to change them. Another advantage of the asynchronous motor is the hermeticity of the design, eliminating the possibility of moisture, dirt and dust entering the motor. Technics with such a drive can work in the most severe conditions. Automatic speed regulation and a small number of rubbing parts reduce engine wear and tear. This power unit has higher power and lower power consumption; in addition, the capability of automatic braking when releasing the accelerator pedal, both on horizontal and inclined planes, eliminates spontaneous machine rollback.
Speed and torque can be adjusted independently of each other, allowing smooth acceleration and braking of the electric motor using only the "gas pedal" pedal. Nowadays, all leading forklift manufacturers produce machines with AC drive. It is assumed that the role of such units in the near future will increase even more: according to various estimates the share of regulated AC drives by 2010 will amount to 66 to 97% of the total market of regulated drives.
There are forklift models with the so-called diesel-electric drive, which combine the advantages of both types of engines. In these machines, a generator connected to the diesel engine generates current and feeds the traction motor through an electronic speed and power control unit.
Another option for a forklift with an internal combustion engine is a gasoline forklift with a gas system installed on it. Usually these are models of small lifting capacity - up to 5.0 tons. Gasoline forklifts use household 30- or 50-liter gas cylinders. It is enough to have 4 ... 8 cylinders for each forklift to take them to refuel no more than once a week. According to some estimates, they make up about 50% of the world forklift truck market.
When working in hot or cold climates the forklifts can be equipped with air conditioners or heaters. Working in seaports, ship holds (depreciation rate is 3 years instead of the usual 6 years), in cold stores, metallurgical plants, in conditions of high fire and explosion are considered to be especially harsh conditions. For these conditions, you should choose a truck with a reliable engine and protected components. Electrical wires and contacts, especially on the electric forklift, should be protected from corrosion, dust, high temperatures. Some companies produce forklifts in special designs, such as for working at low temperatures, for fish processing plants, in an explosion-proof design.
An important factor in choosing the truck is the intended route of transportation: the length of the route, the presence of climbs and turns, ramps, downgrades, the width of the passage, the size of the racks, the presence of foreign objects over the aisle (lamps, metal structures). When working with small loads, in narrow aisles and at low speeds, maneuverable three-legged electric forklifts are usually used. If the work is carried out at higher speeds, with heavy loads, four-legged forklifts are used, characterized by greater stability. Analysis of the route in conjunction with the conditions of work prompts, whether the machine needs a reverse signal, additional lighting equipment and other options, which are usually paid extra.
Type of cargo, weight and dimensions of the cargo area
The main working body of the loader is a fork. The fact is that in closed warehouses for handling most of the cargo weighing 0.5 ... 3.2 tons, pallets (pallets) are used as containers. Thus, the practice of loading and unloading has led to the unification of cargo sizes.
Fork length usually depends on the type of pallets you have to work with and ranges from 730 to 1100 mm. Choosing this working equipment, you should keep in mind not only the size of the pallets, but also the fact that the longer the length of the forks, the greater should be the width for the working passage of the forklift.
In addition to forklifts with front forks designed to handle pallets, there are forklifts with side forks. They, as a rule, are used for long cargo - lumber, rolled metal, etc. At the open areas of terminals the forklifts are used for handling 20- and 40-foot universal containers. Here, in addition to forklift models with a loader-mast, they use forklifts with a telescopic boom and top loading grip of spreader type.
There is a large number of interchangeable attachments for cargo handling, expanding the scope of the loaders and increasing the efficiency of using the machine. Load carriers fit both forklifts and electric forklifts.
Mounting them on the forklift carriage takes minutes.
Of the many interchangeable equipment, the most common:
- fork transverse displacement device (positioner);
- full turn gripper for drums, paper rolls, bales;
- Top loading grip;
- tilt forks with winch;
- blockless crane jib;
- pin for transportation of hollow cylindrical cargoes;
- fork extension;
- jogger, etc.
Stacking height of cargo
This factor is decisive in selecting the type of hoist. On a standard type mast the load is well visible; on such a mast the forks are lifted to a height of 3300 mm, which allows stacking the load on the third tier of racks. For lifting to a higher height - up to 7.0...7.5 m - three-section masts are used. The lifting mast is equipped with a forward-backward tilt function for convenient positioning of the load.
In cramped conditions, such as in railcars, in universal 20- or 40-foot containers or the back of a truck, stacking in two tiers can be used only if the forklift has the function of the so-called special free lift - lifting the forks without lifting the forklift itself, i.e. without increasing the "construction" height of the machine. Not all types of forklifts are equipped with this function. However, if the forklift handles two pallets lying on top of each other at the same time instead of separately, this function, which usually costs extra money, is not necessary.
Warehouse Floor Covering
Concrete, asphalt, metal tiles or special materials are used as flooring. Not only is it important for the forklift to have a floor, but also its condition. If the floor in the potholes, roughness, rapids, it is better to use the models of equipment on pneumatic tires - they better absorb the shocks and bumps and in addition are cheap. If the loader works in conditions where there can be on the floor metal chips, pieces of metal, wire, nails, broken glass, etc., it's better to use equipment on bandage tires, which, however, very rigid and poor protection from vibration. The intermediate and the best option in many cases is the use of so-called solid tires or tires made of "super elastic". Because they are quite elastic but not filled with air, they cannot be punctured.
If the forklift has to work on construction sites, in the countryside, at logging companies, sometimes in the absence of roads, it is better to choose special "off-road" models on pneumatic tires with increased traction and a high ground clearance. There are a large number of models of such loaders, equipped with a loader in the form of a telescopic boom.
Work Intensity
The loaders can be used in one, two or three shifts. At intensive work it is necessary to pay attention to such characteristics of the loader as its maneuverability (minimal turning radius, dimensions of movement (with and without load), lifting-lowering speed, average productivity per shift. It should not be forgotten that with the increasing intensity of forklift operation the expenses for fuel and lubricants also increase, sometimes twofold. When choosing electric forklifts, you should think about the purchase of replacement batteries and their timely recharging.
Safety and Convenience
When choosing a forklift model, it is important to consider the operational factors that determine the safety of work. The relatively large weight of the machine and the cargo, work in confined spaces, high speed of movement and lifting, shifting of the center of gravity when lifting-lowering the load and high maneuverability, the constant movement back and forth increases the probability of injury. According to statistics, the most frequent accidents are caused by the side tipping of the truck when turning at high speed, as well as by dropping a load or part of a load on the roof of the cabin. That's why most models are equipped with FOPS/ROPS cabs and safety belts. In summer, when the cab windows are removed, the buggy-type safety doors are used.
Driving a forklift requires special attention. So the driver does not get tired, the manufacturers pay much attention to workplace ergonomics: reduce noise and vibration, provide the ability to adjust the seat and steering column for the weight and growth of the driver, improve visibility through improved design loader, make the cabin glazing circular, etc. The latest generation models use the most modern features to facilitate the control: LCD display with information display about the parameters of the loader and faults, diagnostic system, joystick control, unauthorized access control system.
Price-Performance Ratio
The price factor in choosing the loader, as well as any other equipment, plays an important, sometimes paramount role. Choosing the loader they are often guided by the principle of cost minimization. Usually they talk about the price-quality ratio. To quantify this ratio, in our view, it is advisable to choose such an evaluation parameter as the cost per motor-hour. This indicator includes not only the purchase price, but also the cost of maintenance and repair, energy and fuel, forklift service life. The best producers declare service life of 16 ... 20 thousand moto-hours (i.e. 10 ... 12 years in one-shift work), but in practice we can meet models with 40 ... 45 thousand moto-hours.
Domestic consumers, most of whom are motorists, prefer lift trucks as more "understandable" equipment. Indeed, low operating costs and high environmental friendliness of electric forklifts turn out to be certain inconveniences: you need chargers, places for charging batteries with exhaust and an appropriate specialist - a battery technician. Nevertheless, the calculation of the cost per hour shows that such trucks are more often cost-effective.
The higher the intensity of operation, the more reliable and easy to use a truck should be. For the three-shift mode only new imported equipment is suitable or it is necessary to create park of loaders of larger number. If the truck is engaged no more than one hour a day, it is possible to purchase a second hand truck of domestic manufacture. In this case, however, there is a high probability that it can go out of order, and the relative cheapness of the machine does not compensate frequent purchases of spare parts. And if you have decided to buy a used machine, take the advice of experts: do not buy a model with more than 10 thousand motor-hours worked.
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