crane first appeared in 1830 in the UK.It was a steam option.Improved model with a hydraulic, was designed 17 years later.But if earlier, when the first cranes, works were carried out by and large manual force or partial mechanization, today, any building, starting with small to large, has at its disposal the construction crane.
little general information
should be understood that a device such as crane, does not exist.There are cranes.This term was given another Gosgortechnadzor.The definition was approximately as follows: crane - a machine having a lifting body (hook, grab, and so on. F.), Which is used for lifting and moving heavy loads.
Today, this technique is widely used in construction.In principle, from the economic point of view it is quite advantageous.Modern crane can lift a load of more than 1000 tons, but suitable for the construction of 50 standard-capacity cranes.
should be understood that for lifting and moving cargo operator needs to make simple manipulations (cycles).In the first stage, the seizure load.If it is a concrete slab, it is tied, and for its lifting hook is used.If this is the bulk material, the work carried grab.The second stage - stroke.He is the direct movement and unloading of transported material.In fact, this is the most important stage, so the work should be performed smoothly and without jerks.The final stage - idling.It involves handling devices return to their original position.Incidentally, stroke consists of three stages: acceleration, deceleration and steady motion.The first and third stages are the most important, since it is they appear dynamic loads and, therefore, the risk of damage to the goods moved.
Building crane and construction
By and large unit consists of several key components.Let's look at each of them:
- Metalwork - the basis of a construction crane.All that can be attributed here - it spans, support, arrows, and so on. N. It is worth noting that they are, and a lattice-type box.In the construction are used most often box-shaped metal.
- Hoist - consists of a flexible lifting body.This can be a rope or chain.This also should include the lifting devices (loop, grab, hook, and so on. N.).The construction of lifting equipment is most often used crane hook.
- lifting body - not an automatic (hook or loop), require minor manual work as well as automatic (solenoid or pneumatic suction cup).
As you can see, construction crane - it is a complex device that requires constant supervision and replacing ropes, hooks and other parts and units.
classification structure and the ability to move
Immediately it should be noted that there is no single classification that would reflect the full essence.The fact that modern cranes can combine the several functions.For example, the following construction cranes depending on the design:
- Jib - lifting body in this case is mounted on the boom.Such valves often used in construction, as their flexibility and mobility enables all work fast enough.
- Bridge - Bridge is a steel structure, which is suspended from the lifting body.
- Cranes cable type.
As for the ability to move, it makes sense to say only two basic types: fixed and self-elevating.The latter type is just used for building construction.Its peculiarity is that it is installed on constructed objects.As the crane lifted the building by means of special mechanisms.Although in recent years increasingly used mobile jib cranes, which are largely technical characteristics lead.This crane is adjusted, if necessary, easily moved to another site.Now let's go further.
tower cranes are the most rational in civil and industrial construction.This is due to the fact that they allow the installation, dismantling and transportation of the forces of vehicles.This reduces manufacturing costs by speeding up the work.But sometimes use a crane does not come out because of an insufficient number of places.In this case, a fast-erecting tower crane.Construction hoists this type of good that does not need much space to install it.However, such a lifting device can not be used at the height of buildings above 30 meters.It is interesting that in one shift valve can be dismantled and assembled on another construction site with minimal production costs.Today it is one of the most appropriate solutions when mobile cranes.
pneumowheel and crawler crane
version running on pneumatic chassis is good in that it has a high cross.In principle, such a construction crane, pictures you can see, is used in close proximity to the object.It managed to achieve this by installing several controlled axes.In addition, the operator's cabin is quite comfortable.There is a computer, which virtually eliminates human error, air conditioning and so on. N. System.
There is also tracked crane.It is installed on the crawler.Despite the high throughput, such equipment can operate effectively only in pre-arranged venues.Transportation by means of a special trailer which increases the operating costs.That is why this is not always used construction equipment.Valves of this type are used only where any other unsuitable.
So we figured out with you what the construction crane.Photos of several popular models you can find in this article.It should be noted that today, this lifting technique is used everywhere.It reduces the risk of injury of production and reduce the amount of manual work.There are a large number of taps, it comes to their type and capacity.Some are designed for fast performance and mobile travel to another object, the other, on the contrary, raise slowly, but quite heavy loads, and stand at the sites for weeks or even months.