Brake Hose - Structure, Performance and Test Methods
制动软管的结构、性能要求及试验方法
1 Scope
This standard specifies the structure, performance, test methods and labeling of brake hose, brake hose end fitting and brake hose assembly for motor vehicle (including motorcycle) and trailer.
This standard is applicable to hydraulic, pneumatic and vacuum brake hose, brake hose end fitting and brake hose assembly for motor vehicle (including motorcycle) and trailer.
2 Normative References
The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments (excluding error corrections) to, 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 editions of these documents are applicable. For undated references, the latest edition of the normative document referred to applies.
GB/T 1690-2006 "Rubber Vulcanized or Thermoplastic -- Determination of the Effect of Liquids"
GB/T 7129-2001 "Rubber or Plastics Hoses -- Determination of Volumetric Expansion"
GB/T 10125-1997 "Corrosion Tests in Artificial Atmospheres -- Salt Spray Tests"
GB 12981 "Motor Vehicle Brake Fluids"
GB/T 14905-1994 "Rubber and Plastics Hose -- Determination of Adhesion between Components"
3 Terms and Definitions
The following terms and definition are applicable to this standard.
3.1
Brake hose
A flexible conduit, other than an end fitting, manufactured for use in a brake system to transmit or contain the fluid pressure, air pressure or vacuum used to apply force to a vehicle's brakes.
3.2
Brake hose end fitting
A coupler, other than a clamp, designed for attachment to the end of a brake hose.
3.3
Brake hose assembly
A brake hose, with or without armor, equipped with end fittings.
3.4
Armor
A protective device installed outside a brake hose to increase the resistance of the hose to abrasion or impact damage.
3.5
Free length
The linear measurement of a hose exposed between the end fitting of the hose assembly in a straight position.
3.6
Rupture
Any failure that results in separation of a brake hose from its end fitting or in leakage.
3.7
Nominal inside diameter
A dimensional description for brake hose. For rubber hose, "φ" and the inside diameter in mm are used to express it; for instance, "φ3.2mm hose" refers to a rubber hose with 3.2mm nominal inside diameter. For plastic hose, "φ" and the outside diameter in mm are used to express it; for instance, "φ8mm hose" refers to a plastic hose with 8mm nominal outside diameter.
4 General Requirements
4.1 The brake hose assembly for test shall be newly manufactured at least 24h in advance Before test, the brake hose assembly shall be kept for at least 4h at 15℃~32℃.
4.2 Before installing the brake hose assembly for flex fatigue test and low-temperature resistance test on the test equipment, all its accessories shall be removed, such as steel wire armor, rubber armor, etc.
4.3 HZY3 grade brake fluid stated in GB 12981 shall be used as the test medium for hydraulic brake hose assembly. If there is any special requirement, the brake fluid of other type may also be used for test, but the type shall be indicated in the test report.
4.4 If there is any special requirement, the test shall be carried out at 15℃~32℃ room temperature.
5 Hydraulic Brake Hose Assembly
5.1 Structure
Each hydraulic brake hose assembly shall have permanently attached brake hose end fittings which are attached by deformation of the fitting about the hose by crimping or swaging.
5.2 Performance
The test on brake hose assembly or appropriate components shall be carried out according to 5.3; the test results shall meet the performance requirements stated in Table 1.
Table 1 Hydraulic Brake Hose Assembly Performance
No. Test item Unit Performance requirement Quantity (piece) Test method
1 Inner bore throughput after necking down a — Pass the full range of the gauge 35 5.3.1
2 Maximum expansion mL/m See Table 2 4 5.3.2
3 Rupture strength b MPa ≥34.5 5.3.3
4 Brake fluid compatibility Inner bore throughput after necking down — Pass the full range of the gauge 4 5.3.4
Rupture strength b MPa ≥34.5
5 Flex fatigue c h ≥35 4 5.3.5
6 Tensile strength N ≥1446 4 5.3.6
7 Water absorption Rupture strength b MPa ≥34.5 4 5.3.7
Flex fatigue c h ≥35 4
Tensile strength N ≥1446 4
8 Low–temperature resistance — No crack 1 5.3.8
9 Ozone resistance — No chap 1 5.3.9
10 High temperature pulse resistance Rupture strength b MPa ≥34.5 4 5.3.10
11 End fitting corrosion resistance — No corrosion on metal base 1 5.3.11
a The assembly shall be cut to carry out a test for inner bore throughput after necking down; 43 test samples shall be selected, 8 of which are used for this test;
b The rupture strength of brake hose assembly with 3.2mm nominal inside diameter shall not be less than 49MPa;
c This test shall be only carried out for brake hose assembly used at the position moving relatively to frame and axle.
Table 2 Maximum expansion
Nominal inside diameter Test pressure
6.9MPa 10.3MPa
Regular expansion hose
(HR)
mL/m Low expansion hose
(HL)
mL/m Regular expansion hose
(HR)
mL/m Low expansion hose
(HL)
mL/m
≤3.2 2.17 1.08 2.59 1.38
4.0~5.0 2.82 1.81 3.35 2.36
≥6.0 3.41 2.69 4.27 3.84
5.3 Test methods
5.3.1 Inner bore throughput after necking down
The gauge shall be selected according to the dimension specified in Table 3 and the requirement of Figure 1. The 76mm full length is inserted into the brake hose under the action of the deadweight of the gauge.
