TecSA proposes AT 7000 machine to run fatigue tests on parking brakes. These tests are requested by brake shoes producers, both OEMs and AMs, to run several stress tests and alternate torsion tests and simulate on testing rig the strains of brake systems on the vehicle.
The brake system is activated by directly apply pressure or by pulling handbrake.
Secondly, torqueing moments are applied to simulate the stresses of the brake on the vehicle.
TecSA’s software is highly flexible to describe several testing procedures, such as:
- Combined action of pressure and pulling of handbrake;
- Forward and backward directions;
- Several modalities of application of torqueing moments;
- Reading and control of eventual sliding and new activation on brake system;
- Simulation of brake stresses of a vehicle on car transporter;
- Simulation of vehicle’s parking on a slope;
- Drag tests at reduced speed.
Here we have the description of vehicle simulation test with the following testing phases:
- Pressure and Static Torque;
- Strength and Increasing Static Torque;
- Pressure and Static Torque;
- Stroke Lock and Increasing Static Torque.
Tests on electric parking brake can be run on the auxiliary EPB Trolley produced by TecSA.
In such a case the cable shall substitute the stationing cable.
Mechanical components
Torqueing moment is measured through a tailstock with two load cells.
First load cell measures torqueing moment (full scale 7000 Nm).
Second load cell measures eventual residual torques with a very high sensitivity (0-100 Nm).
Braking actuation system is activated by the master cylinder through a brushless motor, to allow for very high performances in terms of precision and control and measurement accuracy.
A brake pump of 14 cc (max volume DOT4) is used.
Pressure gradient can reach 1000 bar/sec.
Software and electric components
Control system is completely automated and is managed by TecSA’s software. Real-Time control system allows to run stops in pressure, torque and deceleration.
Pedal stroke measurement is extremely accurate (micrometrical value). This feature is particularly useful for volume absorption tests.
Pressure control and pedal stroke lock allow to analyze torque variation.
The control system of the testing rig is based on a PC with Windows 10. It communicates on-line with PLC Siemens and real-time system National Instruments cRIO at 1 kHz.
Each component is freely available on the market. The Customers can therefore autonomously purchase the spare parts, highly reducing the maintenance and assistance costs.
Alternate torsion test
The cable can be pulled through rigid support (in case of cable without sheath) or through longitudinal and axial floating support (in case of cable with sheath).
Support system can be placed on the right or on the left of the tailstock and can be regulated in height, angle or along testing rig axis.
Handbrake is activated by a brushless motor mechanism with brake and encoder. This solution is similar to the brake pump actuation system.
TecSA’s software applies preload to the cable. Brushless motor brake allows to block the placement of the brake and to simulate the stresses of the brake system of a vehicle parked on a slope.
By simultaneously apply brake pump and brake cable, the testing rig simulates the behavior of the parking phase on a slope: pressure on pedal brake, pull of handbrake, release of pedal brake.
