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This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
This standard replaces QC/T 311-2008 Performance requirements and bench test methods of automobile brake master cylinder, with respect to which, the following technical changes have been made:
——the definitions of terms such as "compensating hole", "center valve", "maximum stroke" and "initial pressure-building travel" are modified (see 3.3, 3.4, 3.10 and 3.11; 3.3, 3.4, 3.7 and 3.8 of Edition 2008);
——the terms and definitions such as "brake master cylinder with compensating hole", "brake master cylinder with center valve" and "plunger brake master cylinder" are added (see 3.6, 3.7 and 3.8);
——the basic requirements are deleted (see 5.1 of Edition 2008);
——the evaluation indexes of residual valve are modified (see 5.1; 5.2.1 of Edition 2008);
——the evaluation indexes and test methods of airtightness are modified (see 5.2 and 8.2; 5.2.2 and 7.2.2 of Edition 2008);
——the evaluation indexes and test methods of initial pressure-building travel are modified (see 5.3 and 8.3; 5.2.3 and 7.2.3 of Edition 2008);
——the evaluation indexes of capacity are modified (see 5.5; 5.2.5 of Edition 2008);
——the performance requirements and test methods of flow of brake master cylinder are added (see 5.8 and 8.8);
——the performance requirements and test methods of compressive strength are added (see 5.10 and 8.10);
——the evaluation indexes and test methods of operating durability are modified, and the test methods of ABS operating mode durability are added (see 5.11 and 8.11; 5.2.9 and 7.2.9 of Edition 2008);
——the evaluation indexes and test methods of vibration performance are modified (see 5.12 and 8.12; 5.2.10 and 7.2.10 of Edition 2008);
——the performance requirements and test methods of cleanliness are deleted (see 5.2.11 and 7.2.11 of Edition 2008);
——the evaluation indexes and test methods of salt spray corrosion resistance are modified (see 5.13 and 8.13; 5.2.12 and 7.2.12 of Edition 2008);
——the schematic diagram for hydraulic test device is modified (see 6.1.5.1; 6.1.5 of Edition 2008);
——the schematic diagram for flow measuring device is added (see 6.1.5.2);
——the requirements for samples and sample installation are listed as a separate clause (see clause 7; 7.1 of Edition 2008);
——the test methods of output function are modified (see 8.4; 7.2.4 of Edition 2008).
This standard was proposed by and is under the jurisdiction of National Technical Committee of Auto Standardization (SAC/TC 114).
The previous editions of this standard are as follows:
——ZB/T T24-1990;
——QC/T 311-1999;
——QC/T 311-2008.
Performance requirements and bench test methods of motor vehicle brake master cylinder
1 Scope
1.1 This standard specifies the terms and definitions, product classification, performance requirements, test devices and test methods of motor vehicle brake master cylinder assembly.
1.2 This standard is applicable to tandem double-cavity brake master cylinder assembly for motor vehicles (hereinafter referred to as "brake master cylinder"), and may serve as a reference for other types of brake master cylinders.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 10125-2012 Corrosion tests in artificial atmospheres - Salt spray tests
3 Terms and definitions
For the purpose of this standard, the following terms and definitions apply.
3.1
fluid supply cavity
cavity connected to the fluid storage tank via a fluid supply hole (see Figures 1 and 2), which supplies brake fluid to the brake service cavity at the moment when the brake is released
3.2
brake service cavity
cavity connected to the brake circuit via a drain hole or a residual valve (see Figures 1 and 2), in which the pressure built during braking is the same as that in the circuit connected to it
3.3
compensating hole
hole on the cylinder body (or piston) where the brake service cavity is connected to the fluid supply cavity (or fluid storage tank) (see Figure 1), which is used to compensate brake fluid to the brake service cavity and return excess brake fluid to the fluid supply cavity where the brake is released
3.4
center valve
valve located on the piston between the brake service cavity and the fluid supply cavity (see Figure 2), which is used to cut off the channels between the brake service cavity and the fluid supply cavity and compensate brake fluid to the brake service cavity under the braking condition; compensate brake fluid to the brake service cavity and return excess brake fluid to the fluid supply cavity where the brake is released
3.5
residual valve
valve located between the brake service cavity and the brake circuit (see Figure 1), which can still maintain a certain residual pressure in the brake circuit where the brake is released
1—cylinder body; 2—secondary cup; 3—primary piston; 4—primary fluid supply hole; 5—fluid supply hole; 6—compensating hole; 7—primary brake service cavity; 8—secondary fluid supply cavity; 9—connecting sleeve; 10—secondary fluid supply hole; 11—compensating hole; 12—secondary brake service cavity; 13—secondary drain hole; 14—secondary piston; 15—primary drain hole; 16—tube socket; 17—residual valve assembly; 18—primary fluid supply cavity
Figure 1 Typical structure of brake master cylinder with compensating hole
1—primary piston; 2—spring washer; 3—spacing ring; 4—secondary cup; 5—O-ring; 6—primary control pin; 7 and 13—primary cup; 8—primary fluid supply hole; 9—secondary cup; 10—connecting sleeve; 11—secondary fluid supply hole; 12—secondary control pin; 14—cylinder body; 15—primary fluid supply cavity; 16—primary center valve; 17—primary brake service cavity; 18—primary drain hole; 19—secondary fluid supply cavity; 20—secondary piston; 21—secondary center valve; 22—secondary drain hole; 23—secondary brake service cavity
Figure 2 Typical structure of brake master cylinder with center valve
3.6
brake master cylinder with compensating hole
brake master cylinder equipped with compensating hole (see Figure 1)
3.7
brake master cylinder with center valve
brake master cylinder equipped with center valve (see Figure 2)
3.8
plunger brake master cylinder
brake master cylinder where the sealing ring is installed on the cylinder body (see Figure 3)
1—cylinder body; 2—secondary brake service cavity; 3—secondary piston; 4—primary cup; 5—connecting sleeve; 6—secondary fluid supply hole; 7—primary brake service cavity; 8—primary fluid supply hole; 9—steel ball; 10—secondary cup; 11—primary piston; 12—secondary piston spring; 13—secondary drain hole; 14—small washer; 15—primary piston spring; 16—primary drain hole; 17—spring limit seat
Figure 3 Typical structure of plunger brake master cylinder
3.9
maximum service pressure
maximum service liquid pressure specified in the design
3.10
maximum stroke
displacement of the primary piston of the brake master cylinder from the installation dimension to the end position
3.11
initial pressure-building travel
displacement of the primary piston where the pressure of brake service cavity reaches 0.1MPa with brake master cylinder in the installation dimension state
4 Product classification
The brake master cylinder products are classified into three classes, i.e., Class A, Class B and Class C according to the operating environment temperature, as shown in Table 1.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Product classification
5 Performance requirements
6 Test devices
7 Sample and its installation
8 Test methods
