brakes, are one of those systems that are installed in all vehicles, cuyos components do not seem to be of great relevance at the time of purchasing a vehicle. In many occasions, we are not aware of the great efforts made by companies to improve the efficiency of the products that are already marketed.
At the same speed, is not the same as stopping a car may be the Porsche Cayenne (which exceeds two tons in weight) that an Alfa Romeo 4C, whose dry weight exceeds a ton, it Seems curious to think, that one of the greatest handicaps of the automotive industry is not developing power; but to develop the capacity of detention.
this Is why, in this occasion, from Today Motor, we want to offer an overview of the most common types of braking systems and their major components to a practical way, we can understand not just the operation; but also, the why of its implementation in each model of car.
As we said earlier, we are in the era in which, to our mind, the main objective for the brands of cars it may be the develop powerful engines and ecological. However, the brakes of a car are the components that perform the opposite action to the mechanical propulsion and without them; a great part of the technologies focused on safety (such as ABS, systems of pedestrian detection, automatic braking systems,…) are meaningless. In addition, behind all of this develop continuously thorough testing with new materials that will help to make new components more resistant, economic and lightweight.
What is the purpose of the brakes of a car? let’s go step by step…
purpose of any braking system is to transform the energy of motion into thermal energy inorder to obtain a deceleration or lock the vehicle when it is parked. In addition, the components that make up the brakes must be able to stop the vehicle being able to dissipate the heat generated with a high efficiency.
What are the components of the brake systems?
Basically, can be summarized in: a control device, actuated by the driver; a hydraulic transmission (which is a mere connector) and the braking device. In recent years, the introduction of technologies such as the ABS, provide greater braking efficiency by multiplying the orders produced by the driver.
this is justified by the Law of Pascal…
Both the drive pedal as the brakes, are connected by a hydraulic circuit. The latter is responsible for driving a large cylinder whose pressure built up is transmitted to the pad or the brake shoe, which make pressure against the disk or against the drum; thus reducing the speed of the vehicle. The viscous fluid used in the hydraulic circuit is a specific compound called, brake fluid.
Why use brake discs?
The increase of the maximum speed reached by the vehicles and the construction of highways and expressways, has precipitated in the replacement of brake systems drum disc brakes on the front axle. The disc (which rotates together at the same speed as the wheel) is applied to friction on both sides.
The advantages presented by the disc brakes is their good cooling, decreasing the likelihood of overheating. In addition to in front of the water or moisture; it will be the turn of the wheel that the eject; so that the brake efficiency remains almost completely.
the accuracy with which you can control the braking is high; however, the stopping power is not possible to multiply it as with the case of drum brakes; and in addition, your detention capacity at stop is lower that in the case of the systems of drum.
what are drum brakes?
The effectiveness of the braking is achieved with the expansion of a brake shoe located in the interior of a cylindrical drum against the walls of the latter; which, in turn, in unison, along with the wheel. As a curiosity, there is an effect that helps to generate the braking force and it is that; when braking, the centrifugal force forces the brake pads to stick against the wall of the cylinder, generating an additional force.
As disadvantages we can talk about the poor or absent capacity of dissipation of water and/ or moisture remaining which causes a decrease of its effectiveness. If this outside little, the heat dissipation is much poorer in a disc brake system.
Disadvantages as a result of overheating
There is a problem that is called “lock-in by steam”; which is due to heating of the brake fluid as a result of exposure to high temperatures derived from the brake pads. This causes the brake fluid boiling and as a consequence, generate bubbles in the interior of the hydraulic circuit. The pressure exerted by the brake pedal is not effective and may ultimately stop working the brakes completely.
Another of the big disadvantages is “fatigue”. This phenomenon occurs commonly when subjected to the brakes to an intensive use in a short period of time. Both the pads as the brakes overheated and com result, produce a gas that acts to lubricate the system and reducing the friction and therefore the effectiveness of the braking.
What types of brake disc are there?
- brake Discs solid. It is the most basic example of brake disk. They consist of a disk of a metal (usually cast iron) that because of their lower cost of production, is implanted in the front axle of many vehicles. Its biggest drawback is the low cooling capacity.
- brake Discs ventilated. We are in front of the drives most commonly used by the automotive industry. Consist of the union of two disks with strips of ventilation between them. If we compare them with the solid discs, the ventilation capacity is 30% higher; lengthening with the brake pad. Its main disadvantage is its greater weight.
- ventilated Disks advanced. They include both the perforated discs as the discs are striated. They are similar to ventilated discs, but in addition, feature perforations or grooves that enhance the driving of the air through them, and with this, your cooling. Normally, they are mounted in high-performance sports and on the front axle.
What… what is that vice?
The jaws are a few components that through a piston, push the brake pads against the disk each time it is actuated to the brake pedal. There are two types:
- Jaws floating: the force that is generated opposite to the main action, causes that the tablet is located on the opposite face press against the wall of the disk. The adjustment of both pads with the disc is continuous and at no time occurs a mismatch in their use. This brings as a consequence that the braking force is constant at all times.
- Caliper piston opposite: on this occasion, the pistons are positioned to both sides of the disc brake; pressing it simultaneously. As a consequence of the increase of weight (by the addition of the two jaws) are typically made of lightweight materials like aluminum. As a drawback, they are required to be mounted with mount-floating, which avoids the deformation of the same due to the heat of braking.
Source – Apex