What is the feature of hydropneumatic suspension for a car
Content
The main function of the hydropneumatic system is performed by spheres. They are under computer control. It consists of three main parts: built-in hydroelectronic interface (BHI), spheres, readout sensors.
Drivers are often interested in not only installing a car's hydro suspension. True connoisseurs are fascinated by the historical side of the issue. The article describes the process of occurrence of this element, as well as the principle of operation of the device.
How Hydractive Suspension Came to Be
Modification of the car's hydro suspension, Citroen's own design in 1954. First installed on the XM and Xantia models, and introduced in 1990. The original Hydractive had two modes - “sport” and “auto”. The principle of operation in automatic switching - set as needed to increase controllability.
Hydractive 2 was supplied to the 2nd generation XM and Xantia. "Sport" keeps the car in soft mode, switching to hard driving. The transition also had two provisions.
Hydractive type suspension
Hydractive 3+ stood on the Citroen C5 of subsequent revisions and C6. In the C5 model, the suspension is hydropneumatic, and the steering and brakes are switched to the usual version. Sport mode for hard driving is back. The suspension uses a new fluid, types of spheres and an electric pump that pressurizes the system immediately after unlocking the car. Hydractive 3 and 3+ left along with the Citroen C5 and C6 models. Hydractive 4 never became a reality.
Elements, nodes and mechanisms
The main function of the hydropneumatic system is performed by spheres. They are under computer control. It consists of three main parts: built-in hydroelectronic interface (BHI), spheres, readout sensors.
The main function of the hydropneumatic system is performed by spheres
Elements:
- five-piston hydraulic pump - powered by an electric motor, controls pressure;
- hydraulic accumulator, 4 four solenoid valves, 2 hydraulic valves - provide height adjustment and anti-seize ability, this also includes a pressure control valve of all described systems;
- computer - reads sensors, controls a five-piston high-pressure hydraulic pump and electrovalves.
The second important component of the hydropneumatic system is the spheres, which are a metal cavity with a membrane inside, which divides the internal volume in half. The upper part is filled with nitrogen, the lower part is filled with hydraulic fluid.
Principle of operation
The suspension functions through a piston acting on the liquid in the sphere, compressing the nitrogen at the top. The gas returns its volume, the quenching is provided by a flap valve in the orifice of the sphere. The substance passes through the part, which causes resistance and controls the movements of the suspension.
Principle of operation
If the liquid does not flow, then the damping does not occur: the car drives hard. The computer decides whether or not to administer the substance based on an analysis of five different indicators:
- angle and speed of rotation of the steering wheel;
- speed of movement;
- accelerator operation;
- braking force;
- body movements.
Advantages and disadvantages
The advantages of the system are:
- Ground clearance remains constant for any load changes.
- The car maintains contact with the road: no roll, which is especially important for heavy trucks. Many GINAF vehicles have hydropneumatics, although this is rather an exception to the rule.
- There is no need for an anti-roll bar in the car.
- The suspension does not require maintenance up to 5 years.
- Increased dynamic stability by reducing ground clearance when the speed is over 110 km / h.
- Good handling and comfortable ride by adapting to road conditions.
Despite the advantages of the device, experts say there are certain problems.
System advantages
Disadvantages:
- a sensor malfunction can cause incorrect switching of driving modes;
- when changing tires, special precautions must be taken;
- more expensive than conventional suspension;
- only garages equipped with special tools and a qualified technician can repair the hydropneumatic system.
- suspension design is complex, expensive to manufacture.
How to use
There are two modes: soft and hard. Removing the spheres from the chain strengthens the hydraulic suspension, making the ride more skittish. The basic setting of the machine will be soft after turning on the normal mode. The computer itself will go into a hard position and back when conditions require it. Clearance is set automatically by the system, but can be changed manually.
Repair Price
In the case of the Citroen C5, the replacement of the front hydraulic shock absorber starts from 1.5 thousand rubles. Installation of a new hydro-electronic block (BHI) starts from 2.5 thousand rubles, and the element itself costs around 100 euros, and it is not easy to buy it.
The front stiffness regulator will cost from 4.5 thousand rubles, the rear - 1.5 thousand rubles. Spheres change from 800 rubles, the details themselves cost from 3 thousand rubles. and higher.
Prices for Mercedes or heavy trucks will be more tangible. Parts for the car are not cheap, and it is more difficult to disassemble the hydropneumatic suspension yourself than in the spring one. In addition, not every service station will be able to repair the part with high quality. In the case of Citroen, it is recommended to check with employees for the availability of a special diagnostic scanner, as well as find out about original spare parts.
