Pneumatic shock absorber for car

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:41

Air suspension is installed by many car manufacturers. Structurally, it is more complex than shock absorber struts with oil or gas-oil filling, but it is more durable and not subject to overheating.

Air suspension components

The air suspension consists of three elements:

• pneumatic shock absorber;
• air supply adjustment module;
• compressor.

In some cars, receivers are additionally installed so that the air supply to the shock absorbers is faster and quieter.

The air suspension is controlled by an electronic control unit that takes readings from various sensors - road surface, speed, body position and driving style.

Working principle

Pneumatic shock absorbers adjust the position of the body not only in motion, but also during parking.

When operating in automatic mode, the ECU (Electronic Control Unit) constantly corrects the position of the vehicle based on the specified distance from the body to the wheel. This does not take into account the workload:the car does not sag if, for example, there are a lot of things in the luggage compartment.

Forced body height changes according to the parameters set by the driver. During off-road driving at low speed, the ground clearance is specially increased to eliminate the possibility of damage to the bottom. In normal mode - medium speed, flat road - the body is in the middle position. If the car rushes at high speed, then to improve its aerodynamic characteristics, the body "squats".

The choice of stiffness of pneumatic shock absorbers for the car also depends on the operating conditions. This quality is also controlled by the ECU.

Air adjustment process

The air pressure in the air spring is generated by the module. It either pumps it into the body, thereby squeezing out the piston and lifting the suspension, or removes it, softening the running gear and reducing the fit of the body.

In the event of roll, for example when turning, more air will be pumped into the front and rear air shock absorbers on one side, and less air will be pumped into the shock absorbers on the other side. This ensures the stability of the machine while driving.

During an off-road trip, the pressure in the air shock absorbers is adjusted individually for everyone: that is, a decrease or increase in air pressure can occur only in one of them.

In the static state of the car, the position of not only the body, but also the suspension is adjusted, which preventspremature wear of some of its elements, such as stabilizer strut hinges, which experience increased loads even while parked on uneven surfaces.

Pneumatic suspension "Volkswagen Tuareg"

VW Touareg pneumatic shock absorbers have a classic design, but are adapted to the weight of the SUV, and therefore have some differences from the struts for passenger cars:

• two receivers for the front and rear axles with increased volume;
• compressor with more power;
• air cylinders also with large chamber volume.

Since the load on the front axle is always greater, the design of the front air springs is more complicated. Unlike the rear ones, it is reinforced with dampers - a vibration damper at the bottom and an additional one at the top.

Pneumatic shock absorbers for domestic cars

Unfortunately, the domestic manufacturer does not complete its cars with air suspension, oil shock absorbers are installed in the factory assembly. To increase comfort and maneuverability, car owners install pneumatic shock absorbers on VAZs, which they make on their own.

A regular oil shock absorber is taken as a basis. A pneumatic spring with protective rubber rings - a Rubena semi-set is installed on its stem, and the entire structure is fixed with a sealant. This method is acceptable for front suspension struts.

Rear shock absorbers are also improved withsprings, but instead of a semi-set, a sleeve air spring is used. It is worth noting that such a system is equipped with a reinforced fitting, so you can install an air supply tube into it only once.

When the air shock absorber is assembled and installed, it is inflated with air to the required suspension height. After that, adjust the camber angle.

It is worth noting that too high position of the body will lead to breakage of the cross connecting the cardan shafts, and if the position is too low, the wheels will touch the lower part of the wings of the body and protection.

More complex, but also more functional, is the design of a self-made air suspension with control. To do this, they additionally install sensors and an electronic control unit, a compressor and air bags, if desired, you can add a receiver that will control minor changes in the position of the body without the participation of the compressor.

Pillows can be installed as an independent element or paired with a standard spring. The compressor and receiver are conveniently placed in the trunk.

Special attention here requires suspension calibration after installation. Correction must be carried out on a perfectly flat surface, determine the position of the body first without additional load, and then in running order. Make sure all pillows are inflated evenly. And most importantly, check all connections for air leaks. This can be done either by ear or with soapy water.

Flawof this design is that its elements cannot be repaired, they can only be replaced with new ones.

Application possibilities for pneumatic shock absorbers

Pressurized air replaced the oil not only in the suspension struts, but also in the hood air dampers. The use of gas lifts made it possible to abandon the use of a support rod, which is needed to maintain the hood cover in a raised state.

However, the design of air shock absorbers requires special handling. In winter, you have to open the hood much more often. To prevent the shock absorber from failing, it is necessary to lift the cover smoothly, without sudden movements, and if possible, start the engine first, allowing the gas lifts to warm up. Otherwise, their seals may be destroyed, which will lead to depressurization of the case.

It is possible to install pneumatic hood shock absorbers on any car, but you must take into account:

• hood cover weight;
• height of its rise;
• expected opening frequency.

The greater the load expected on gas lifts, the more wear-resistant they must be. The characteristics and load capacity of these elements are always indicated in the documents or on the packaging.

Air spring press

It is not difficult to make a manual pneumatic press from a shock absorber with your own hands. To do this, you will need the shock absorber itself, a compressor to create atmospheric pressure and a hose with a fitting for air supply.

On the bodyshock absorber, preliminary marking is done in the place where the fitting will be inserted. The hose should be connected to the fitting with a clamp so that it does not disconnect at high pressure.

The fitting is built into the shock absorber body, and a compressor (or air pump) is connected to it through a hose. If the shock absorber rod comes into action when air is supplied, then the press is made correctly. To increase the area of impact on the pressed material, a metal disk is attached to the end of the rod.

This design can be made desktop, but also, using a welded frame, transform it into a separate portable element.

How to make a homemade hot press

While an ordinary homemade pressing device can, for example, be bent or compressed, with the addition of a heating element, functions such as embossing or hot gluing appear.

To finalize the press, you will need a heating element - a heating element and two microcircuits: one - to turn on the heating of the heating element, and the second - to control the pressure and operation of the rod.