The Design And Development For Test-bed Of Brake Master Cylinder And Vacuum Booster

Brake master cylinder and vacuum booster is the most important component in brake system, and the braking performance quality directly affect safety of driving. For brake master cylinder and vacuum booster, all countries have their own national standards and divided into American Chrysler standards, Volkswagen standard, Japan Isuzu standards, Peugeot standard etc. Our current market share of independent automobile is still relatively low. Most manufacturers adopt foreign production standards. So braking system manufacturers should produce various types of brake master cylinders and vacuum boosters because of the standards are different. This makes brake master cylinder and vacuum booster assembly testing standards are not uniform.The test-bed of brake master cylinder and vacuum booster is the instrument to test brake master cylinder and vacuum booster and two assembly properties. At present, the domestic such testing product exists some problems.for instance, the single function, lower automatic degree, lower accuracy. The price of imported product is too expensive and the standards are various. And they can not be upgraded, so develop new testing equipment independently becomes the inevitable choice of each manufacturer. This paper topic is from demands of auto company. The test items standard follow QC/T311-2008"Automobile Hydraulic Brake Master Cylinder Technical Conditions", QC/T307-1999 "Vacuum Booster Technical Conditions" and the enterprise standard of the company. At the beginning of the test contains established pressure stroke and input-output characteristic, sealing, pressure impact test items such as sixteen projects.Based on the theory of testing structure,the paper discusses detailed test process, and develop the testing equipment on the basis of the test process. The test-bed of brake master cylinder and vacuum bosster constitute of four sub-systems, for instance, respectively strength subsystem, vacuum subsystem, pneumatic subsystem and hydraulic subsystem. To simulate the brake pedal strength subsystem of strength effect, adopted spool servo valves-symmetric cylinder add closed-loop PID adjustor control mode, can be precisely controlled loading and unloading process. Vacuum subsystem simulates engine intake manifold to vacuum booster provide vacuity. Pneumatic system is responsible for detecting sealing. Hydraulic subsystem simulates the action relations between brake master cylinder and wheel cylinder. The test-bed can simulate the real car running braking.The control system of the test-bed is a collection control system based on Advantech PCI-1710 multi-function data acquisition card. And the analog I/O and digital I/O integration in the same interface card. Make the card centralized control. The software is compiled by LabVIEW 8.6. The paper design methods write test procedures by structural module and function module. Make the interface of operation simple, and in such a short period of mastery. Test the requirements of the vacuum, schedule, hydraulic and pneumatic etc through industrial computer control servo valves, solenoid valve realization. Bench on displacement, hydraulic and pneumatic sensors in test process devastates signals to the computer, IPC capture every analogue changes in real-time, according to the controled requirements. The test curve and test report is complete by the test process is made. After the test, users can chose to preserve data or output report.