Modern drivers practically do not use "antique" hand or foot pumps for pumping wheels. In place of such units came automatic devices virtually undemanding the participation of people in their work.
The general advantages uniting all types of devices is compactness, ease of use and relatively low price. After acquiring an autocompressor, there is no need to regularly call in to the bus station for tire inflation. For those who still choose which car compressor is better, it is worthwhile to carefully study all the advantages and disadvantages of various models and designs.
- 1 Piston or membrane?
- 2 Piston compressor
- 2.1 Minuses
- 2.2 Pros
- 3 Diaphragm compressor
- 3.1 Minuses
- 3.2 Pros
- 4 General characteristics of compressors
- 4.1 Performance
- 4.2 Pressure
- 4.3 Power Connection Options
- 4.4 Indicator
- 5 Additional equipment for compressors
- 6 Tips for Buying a Compressor
Piston or membrane?
There are two types of automotive compressor designs. The first is used to operate the membrane using a vibrating structure. The latter are used for pumping the reciprocating motion of the piston. In both cases: and diaphragm and piston The devices are powered by a car battery. Sometimes there are instances with an additional battery built into the compressor unit.
The air in this unit is injected with a piston mounted on a crank mechanism. The crankshaft is driven by the operation of an electric motor. The high-quality electric motor ensures uninterrupted operation for a long time.
It is believed that the effectiveness of this design is higher membrane mechanisms, by reducing losses. Also, piston compressors deliver more pressure due to the stable operation of the mechanism. However, this depends on the specific apparatus, the quality of manufacturing components, the fit of the mating parts and assemblies.
An important criterion is the volume of the working cylinder.in which the piston “walks”. This will increase the amount of injected air in one cycle. In general, the overall performance of the device depends on this parameter. Therefore, to completely transfer the primacy from the piston structure to the membrane will be wrong.
The most effective design is an apparatus with a minimum number of intermediate links. Then losses on different sites of a chain decrease.
During the working cycles of air compression, the apparatus is subjected to significant loads. This can often be seen when pumping large wheels of minivans or SUVs. Such overloads can unexpectedly disable the compressor. In order to prevent the device from reaching such a state, it is necessary to periodically let it cool every quarter of an hour. If this is not done, the electric motor will burn and a new device will be required.
The frequent absence of ventilation systems in some reciprocating compressors contributes to the accumulation of dust inside. This leads to a decrease in pressure, respectively decreases performance. more time spent pumping.
With significant development or mechanical breakage of the piston or cylinder will not be able to replace this pair. Such a compressor is not repairable.
Cylinders from stainless alloyed steel with the polished internal surface have the maximum term of operation. In a cheaper configuration often put cylinders made of galvanized steel, which have a much smaller resource. When buying, you can clarify this design feature.See also: Doing an airbrush with your own hands
A positive factor for a piston compressor is the ability to pump significant pressure up to 8 atmospheres. Although in practice this pressure is rarely seen in everyday life, but it means reliability and the possible performance of the device. Also, the piston design has no seasonal restrictions for use. Even in severe frost the device will not lose its working capacity.
The working element in such devices is membrane cloth. Its tension or weakening in both directions makes it possible to move the air flow. Only a pair of bearings is involved in working with the membrane.
In the event of failure of this fabric, you can even independently carry out the replacement of the membrane.
An unfavorable season for the operation of such a device is winter time with low temperatures. The material of the canvas loses its elasticity and “coarsens”. This can lead to ruptures in the rubber web.
A negative factor is a weaker performance compared with reciprocating compressors. This unit is able to dial only up to 4 atmospheres. However, most mid-size sedans need tire pressure at 2 atmospheres. Also it is ineffective in frosty weather. Although it can be used in the garage conditions in the home. Most often used for wheels less than 14 inches, since its performance is lower than that of the piston.
Breakdowns happen very rarely. If a rupture of the membrane occurs, it can be changed. on another rubber canvas. The cost of the device is much lower than that of reciprocating compressors.
General characteristics of compressors
Before you choose a car tire inflation compressor, you need to pay attention to several performance characteristics and design. Maximum parameters are not always required, and high effect will be from balanced optimal parameters.
Data from manufacturing companies are usually listed in liters per minute. Standard indicators for an average compressor are 30-40 liters. With such power, it is possible to pump up four slopes of 14 inch rubber in 20-25 minutes without such problems. If you want to work with large-sized tires, you will need to choose a device that produces up to 70 liters per minute.
If the mechanical pressure gauge has a markup to 20 atmospheres, this does not mean that the compressor will also be able to pump this pressure. On average, the maximum value for such units ranges from 4-8 atmospheres. The demand for such parameters is often questionable, so it is better to focus on other indicators. Sometimes an Asian design has a markup of 300psi (pounds per inch2). In the metric system it is 20 atmospheres. The unreality of achieving such a parameter is evident from the design of the device.
There are autonomous devices with a battery on board and connected to the car battery either through the cigarette lighter socket or directly through the terminals. In the first case, it is rarely possible to pump more than three wheels without additional charge. Therefore, it will be more profitable to design with external feed from the car. Powerful tire compressors are powered directly to prevent damage to the wiring. Such devices are suitable for SUVs or minibuses.See also: How to choose a car dvr
A pressure gauge is mounted to determine the pressure level during injection. It can have analog or digital indication. The first option is the more common and inexpensive option. However, during the operation of the compressor, it is difficult to determine the exact pressure level, as the needle vibrates a little near the indicative figures.
Markings are set on the dial for metric readings in kg / cm2 and in the Western European system of calculation in pound / inch2. The extra scale often distracts from reading data.
Compressors with digital pressure display are preferred. Accuracy of display to hundredths of the atmosphere. When switching, it is possible to choose the most familiar units of measurement. Also, most electronic devices are equipped with a stop system after reaching a given parameter. This option is convenient during cold or rainy weather, when there is no need to stand over the compressor to turn it off.
You can check the accuracy of the graduation scale in any center of standardization and metrology. With regular visits to this organization, you can set the error and the exact class of the device.
Additional equipment for compressors
When choosing a compressor, car owners often try to invent an application for him outside the period when pumping wheels is required. After all, often most of the time the device lies idle in the trunk or garage.
Manufacturers also try to give versatility to this device and equip it with additional functions:
- air exhaust It can be claimed by tourists in nature, when you need to quickly “blow off” a mattress or a rubber boat;
- bleed valve will help reduce pressure on slippery roads or when driving on sandy ground;
- auto power off often installed in compressors with digital indication, convenient during bad weather;
- the presence of thermal relay protects the device from overheating and failure of the electric motor;
- when complete several additional adapters, then they can be used to pump balls, mattresses, boats;
- often the construction is complemented a lanternworking either from an autonomous battery or from finger-type batteries.
Tips for buying a compressor
At the choice it is worth considering material of which the case is made. Devices with a metal shell will last longer, does not break, unlike plastic in the cold. However, plastic is a lighter and non-corrosive material. More expensive compressors use frost-resistant material.
The length of the hoses must be such that, without additional extenders, there is enough size for inflating all the wheels. It is desirable to select their material reinforced, without cracks and other visible defects. Too soft plastic or rubber can block the passage of air in places of kinks. Too hard will be bad to straighten and get close.
It is advisable to select a threaded fitting. During pumping the hose will be more securely fixed than with the lock fastening. When buying in the auto shop you need to require a warranty card.