Pneumatic nutrunner what compressor is needed. Advantages
Design and operating principle of the pneumatic impact wrench, choice of compressor, hose, oil
Any master knows that the most time-consuming process when mounting constructions or repairing mechanisms is the unscrewing and tightening of threaded connections. But if you use pneumatic wrenches for this purpose, then such work turns into a mere formality. This handy tool has many advantages, but the nuances of its operation are worth learning more about.
Design and principle of the air wrench
The following illustration shows you in detail how the impact wrench works. The unit consists of the following elements housed in a solid metal housing.
- High performance air motor.
- Impact mechanism.
- Stainless steel chuck (stop).
- Torque controller, and reverse.
- Start button.
- nozzle for connecting hose from compressor.
- Air valve.
This unit is much lighter than its electric counterpart due to the lack of a motor. And the torque of the impact wrench is high. from 300 to 2200 Nm (Newtons per meter).
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Inside the unit, it is possible to distinguish 2 main power units, each of which is designed to work in different modes.
The first unit is a pneumatic motor that transmits the rotary motion to the tool head. The second unit is the unit that creates the shock loads.
The pneumatic actuator rotates due to the compressed air flowing through it by means of a high-pressure hose from the compressor.
There are 2 channels in the body of the apparatus. The air is directed in different directions on each of them relative to the turbine. In the first case, the air pushes the turbine along the ch. the arrow, i.e. in the twist, and in the second. against the wrench. arrows, to unscrew the fasteners. Air flows are distributed by a special switch.
The principle of operation of the pneumatic nutrunner is as follows.
- After pressing the start button, the valve opens, and the air flow from the hose connected to the body of the unit begins to move through the turbine, rotating it.
- From the turbine the rotary motion is transmitted to the striking mechanism, which in its principle of operation resembles a clutch. There are two cams in the mechanism. The impact force is generated by the cams at the moment when there is insufficient torque to release the fastener.
- Then, the rotary motion is transmitted to the stop (chuck), on which the nozzle is dressed to a certain size of nut. As a result, the fastener can be tightened or loosened. Some air wrenches do not activate the impact mechanism when screwing in, the process takes place in hammerless mode.
- If the nut is stuck, more force is required to undo the nut, at which point the stop rotation stops.
- The hammers start to deflect backwards and at the same time they turn.
- In the next stage the jaws bypass the stop and continue moving and gaining inertia.
- As it continues to rotate, the jaws engage again with the end stop and hit it (in the direction of movement).
- The impact pulses continue until the fastener is “ripped” out of place.
Thus, with the pneumatic impact tool the process of unscrewing tight bolts and nuts is quick and easy.
Choosing a compressor for an air ratchet
Many motorists, buying a pneumatic wrench, wonder what kind of compressor is needed for this unit. First of all, it is necessary to pay attention to its performance according to the certificate.
There is a nuance here: some firms producing compressors, in order to increase sales, indicate the capacity not at the output, but at the input. For example the documentation of the machine shows a capacity of 210 liters per minute.
So, this should be interpreted as the rate at which the compressor is pumping air into itself, i.e. into the receiver. On the other hand the output can drop by approx. 30-40%. And it turns out that the unit actually produces only 146-127 l/min.
Based on the above, it is clear that if the compressor capacity is specified as 210 l/min, you need to choose an impact wrench with significantly lower airflow rate.
For example, if an operating airflow of the tool is 200 l/min, but a compressor by documentation is 210 l/min (actually. 146-127 l/min), such tool will not unscrew or tighten properly you will have nothing.
over, the air tank capacity also plays an important role. Household appliances can have a capacity of only 24-50 liters. Under these conditions the impact wrench will not work properly.
Even with a receiver volume of 50 liters, after a few seconds the pressure in the tool decreases significantly, and to continue working, you have to wait until it is restored.
Therefore, the receiver of the compressor must have a volume of more than 50 liters, and the unit itself to create a pressure in it not less than 6.2 kg/cm². Otherwise the machine cannot develop the necessary power.
But it must not be allowed to have too much pressure in the system. the use of a ratchet wrench is no problem with tightening fasteners on the wheels. if the recommended pressure is exceeded, it will undermine the main components of the tool, leading to their rapid wear and, as a consequence. the yield of the nutrunner out of operation.
The result of the above is as follows: if the tool is designed for a working air speed of 119 l / min, but the compressor for a nutrunner produces 135 l / min in reality, then with its help you can easily unscrew and tighten the fasteners on the wheels. But do not forget that the tool should have a torque not lower than 550 Nm.
Choice of hose
It is important to know that a hose that comes with a compressor, especially a compressor made in China, will not work well with an impact wrench. Most of the time these hoses have an inner diameter of about 6 mm.
The main characteristics of the tool
When choosing a pneumatic type tool, always pay attention to the manufacturer. Sometimes this criterion is the main one. This is not always justified, because the brand is just a well-known brand, and the buyer needs a nutrunner for a specific task, so the first criteria in choosing should be:
Specifications of pneumatic wrenches.
- rotation speed;
- maximum force;
- working pressure;
- air flow rate;
- availability of reverse;
- the size of the planting square;
How to choose a impact wrench with so many features? Some people distinguish the most important for their work and focus only on them. For example, if the tool will be used only in everyday life several times a year for twisting off or tightening the most simple and uncomplicated threads, you can safely choose a light and low-power device with a seating square of half an inch. Sockets size. from 8 to 36 mm, tightening torque up to 1023 Nm.
However, the functionality of the pneumatic screwdriver depends on its design. The tool, which is designed for large-sized nuts, must exert a commensurate force, so its motor must be powerful. And the more powerful tool is, the bigger its dimensions are. Small models are designed to work with small sizes, often found with angular placement of the shank. Determine how hard the device can tighten the nut by reading the torque. When choosing this characteristic of the product, find out what you need to do with a pneumatic screwdriver: unscrew small and medium-sized nuts and bolts, or work with huge parts.
Advantages of pneumatic wrenches.
There are cases where you need a different size of interchangeable heads, then it is better to pay attention to the foreign manufacturer. If you need a wrench size of 10-27 mm, then the planting square should be selected by half an inch, and the striking heads of the square. 8-36 mm. Wrench size up to 41 mm requires a 3/4 inch square, and the tightening torque wrench should choose a more powerful (up to 1900 Nm). Wrenches with a 1″ square footage and torques up to 5000 Nm can handle large nut sizes. As for the tightening torque regulator, it is not present on all models and in some (China) it is unreliable because it fails quickly. this is one of the “sore spots” of the nutrunner, because no manufacturer can guarantee the accuracy of this tool.
How to choose a pneumohawk wrench for garage and car service
Impact wrench. one of the most efficient tools for fast tightening/unscrewing with compressed air. Exactly with a nutrunner car servicing is associated. They make tightening and loosening screw connections quick and easy.
And if until recently, pneumohawk wrench is mainly used in car repair shops, tire changers and service stations, but now this tool can be seen more and more often in the normal garage.
Nowadays, the cost of “re-shoeing” one car twice a year is already commensurate with the cost of a pneumatic nutrunner model for your garage. And if there is more than one car in the family and hands grow out of the right place, the purchase of a nutrunner can also bring profit. The most important thing is that it is fast and efficient and that the person spends less effort on undoing the nut.
Let’s analyze which types of impact wrenches there are, and which characteristics to pay attention to, and which are unimportant. Let’s look at the main point. how not to miss a compressor.
And here are some basic maintenance rules to keep the tool in good working order for a long time.
The principle of the impact wrench is simple:
The impact wrench can be connected to a compressor or a compressed air line via a coupling. When the tool is pulled, compressed air flows in a hose, rotates the rotor of the tool, which in turn drives the spindle. That’s right
The reverse drive function makes it possible to reverse the direction of rotation, i.e.е. You can not only tighten the fasteners, but also unscrew them.
How much pressure do you need for your air-powered tool??
|Air screwdriver||110. 200||6. 8|
|Pneumatic grinder||80. 550||6. 6,5|
|Pneumatic spray gun||50. 360||1. 6|
|Airgun||50. 300||1. 8,5|
The higher the torque, the larger the fastener dimensions, the larger the diameter of the spindle.
Which air grinder to choose: rating of the best, reviews
You can choose a blowtorch correctly if you carefully study its parameters. This determines whether the tool can do the job. Nutrunners are not only pneumatic, but also work with electricity. This nuance should also be taken into account, because there is not always a compressor at hand. If you need a mobile tool in the car, then it is better to consider cordless models.
How to use the tool
The following work rules should be observed to ensure that the service life of a tool is truly long:
- Before using the device, make sure that the air fed is dry and enriched with a special oil, which is often included in the kit. When using moist or raw air, the tool’s service life is noticeably reduced.
- The air volume should correspond to the data declared in the tool’s certificate.
- It is necessary to use only percussion heads to avoid premature wear of the shaft.
Air Compressor Maintenance | Oil and Filters | CompressedAirUSA.com
Tips for Using an Air Wrench
To extend the life of your air tool it is recommended that you take some professional tips from your handyman.
- Avoid dropping your tool.
- Make sure that the air tool is not in an area where it could be hit by a vehicle.
- Do not over-pressurize the system to increase torque. It will cause rapid wear of the unit.
- Do not hold the impact wrench under load for a long time because this mode of operation will quickly destroy the impact mechanism. If a stuck nut or bolt is not loosened within 5 seconds, stop the machine and replace it with a more powerful tool. It is also recommended to use for problem bolts penetrating fluids, which are in the arsenal of any car owner: gasoline, antifreeze, kerosene, diesel fuel, brake fluid. It is best to apply a special liquid, e.g. WD-40, to the threaded joint.
- Do not store the tool near fire, as well as in places with high temperature and humidity.
If you follow these simple recommendations, your tool will be an effective assistant in time-consuming operations, will serve you for a long time and will justify the investment.