LPB Brake Pads
How does LPB evaluates a Brake System?
LPB's manufacturing plant have 21 dynamometers (6 equipped with ECU). Using them, the LPB engineers can simulate and evaluate different brake properties, such as green, characteristic value, fading at high speed and temperature, cold, recovery, wear and NVH, etc.
Friction coefficient has an important role on the stopping distance of vehicle (although its not the only determining factor). Friction coefficient is not a constant value.
1. Appropriate and stable performance
Appropriate friction coefficient to the application area and vehicle
Low dependence on the pressure, speed, temperature and environmental influences
2. Less fade at high-temperature
Brake system generate heat during braking
Fade performance determines the brake safety during high-temperature braking conditions
Brake Effectiveness - Dynamometer
Advantages of Bedding-in
Burn off volatiles from the resin that is near pad surface. This will eliminate “green fade”.
Establish a layer of transfer film about a few microns thick on the rotor surface. Shearing of the film during friction is an effective source of friction force. Otherwise, when using a freshly ground rotor without the transfer film, the main friction force would come from cutting, plowing, or scoring the asperities on the rotor surface. This leads to inconsistent braking effectiveness.
Mate the two surfaces to a near perfect geometrical match, so that the contact area is high, and therefore the friction force is increased.
If bedding in procedure is not applied, a stable transfer film may not be established for a long time. In other words, the rotor surface would have to be constantly regenerating a film that is not quite stable for a long time. This effect would reduce the performance and increase the wear.
How to improve vehicles braking performance?
Brake performance will be positively impacted by improvements in the following areas:
Better brake pads
Larger diameter rotors (more brake torque)
Assuming that you have good tires on your vehicle- the simplest, and most cost effective improvement comes from better brake pads.
What is a brake noise?
Brake noise typically originates from vibration on a part within the wheel end section of the vehicle – between the tire, and the connection to the chassis. The reason of vibration can be many vehicle parts, such as suspension, wheel, bearing, and there are complex vibration excitation-transmission mechanism among them.
For the brake system itself, it is normal to experience several vibrations when braking (especially between the caliper parts and backing plate of brake pads), but because the smaller vibration intensity, frequently we can not hear it. It is only when the vibration increases that there is an audible noise.
Brake noise is a system problem, it can originate in any of the parts from the wheel bearing to the suspension component – it is not always caused by brake system itself.
Brake noise - Dynamometer
Service Life of Brake Pads and Discs
Match between formula-vehicle model and use environment.
- The main factors which influence wear performance is pressure, speed and temperature, and temperature is the most important.
Service Life of Brake Pads and Discs - Dynamometer
Mechanical performance of brake pad reflect its structural characteristics, and it is very important to control the product quality.
Shown here, are the commonly-used physical tests:
Brake pads are made up of metal or carbon fibers bonded with a polymer adhesive. The oxidized metal particles and carbon material can attach to wheels when braking, and leave marks that are tough to remove. This is brake dust.
Ceramic brake pads show better brake dust property compared to metallic pads because of smaller contents of metal & carbon fibers.
Humid environment accelerates the generation of brake dust.
What is a brake judder?
Brake judder is the vibration or shake felt through the steering wheel, vehicle body and suspension when brake at certain speeds and pressures. It can vary from a barely noticeable vibration to a violent judder, and can be experienced in two ways:
a pulsing feeling in the brake pedal -– almost as intense as the feeling when the ABS system is activated
or a shake of the steering wheel