This standard specifies the performance requirements and bench test methods of the automobile brake master cylinder.
This standard is applicable to the series dual chamber brake master cylinder assemblies of automobiles (hereinafter referred to as "brake master cylinder"), and other types of brake master cylinders may be implemented by making reference thereto.
2 Normative References
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding the correction contents), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest edition of these documents is applicable. For undated references, the latest edition of the normative document is applicable to this standard.
GB/T 10125 "Corrosion Tests in Artificial Atmospheres-Salt Spray Tests" (eqv ISO 9227: 1990)
QC/T 572"Rules for Cleanliness of Automobile-Determination Method"
3 Terms and Definitions
The following terms and definitions apply in this standard.
3.1
Fluid supply cavity
A cavity (see Figure 1 and Figure 2) connected to the fluid reservoir through the fluid supply hole. This cavity will supply the brake service cavity with brake fluid at the moment the brake is released.
3.2
Brake service cavity
A cavity (see Figure 1 and Figure 2) connected to the brake circuit through the fluid drainage hole or residual valve. During the braking process, the hydraulic pressure built in brake service cavity is equal to the hydraulic pressure in the circuit connected to the brake service cavity.
3.3
Compensating hole
A hole in the cylinder body (or piston) that connects the brake service cavity and fluid reservoir (or fluid supply cavity) (see Figure 1 and Figure 2). This hole will compensate brake fluid for the brake service cavity or return the brake fluid to the fluid reservoir at the brake releasing state.
3.4
Center valve
A valve on the piston, set between the brake service cavity and fluid supply cavity (see Figure 1). At braking state, the passage between brake service cavity and fluid supply cavity can be cut off under the control of this valve; at the brake releasing state, brake fluid can be compensated for the brake service cavity under the control of this valve.
