GB/T 37336-2019 English PDF (GBT37336-2019)
GB/T 37336-2019 English PDF (GBT37336-2019)
GB/T 37336-2019: Brake drum of automobile
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
Brake drum of automobile
ISSUED ON: MARCH 25, 2019
IMPLEMENTED ON: OCTOBER 01, 2019
Issued by: State Administration for Market Regulation;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Classification ... 5
5 Technical requirements ... 6
6 Inspection methods ... 9
Appendix A (Normative) Bench test methods of brake drum ... 12
Brake drum of automobile
This Standard specifies the terms and definitions, classification, technical requirements, and inspection methods for brake drum of automobile.
This Standard is applicable to the brake drums, whose body material is gray cast iron, for service brakes of types M and N vehicles specified in GB/T 15089- 2001.
2 Normative references
The following documents are indispensable for the application of this document. For the dated references, only the editions with the dates indicated are applicable to this document. For the undated references, the latest edition (including all the amendments) are applicable to this document.
GB/T 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyrylmethane phosphomolybdate gravimetric method for the
determination of phosphorus content
GB/T 223.58 Methods for chemical analysis of iron, steel and alloy - The sodium arsenite-sodium nitrite titrimetric method for the determination of manganese content
GB/T 223.59 Iron, steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony
phosphomolybdate blue spectrophotometric method
GB/T 223.60 Methods for chemical analysis of iron, steel and alloy - The perchloric acid dehydration gravimetric method for the determination of silicon content
GB/T 223.62 Methods for chemical analysis of iron, steel and alloy - The butyl acetate extraction photometric method for the determination of
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 231.1 Metallic materials - Brinell hardness test - Part 1: Test method GB/T 1031 Geometrical product specifications (GPS) - Surface texture:
Profile method - Surface roughness parameters and their values
GB/T 1958 Geometrical Product Specifications (GPS) - Geometrical
tolerance - Verification
GB/T 3177 Geometrical product specifications (GPS) - Inspection of plain workpiece sizes
GB/T 7216 Metallographic test for gray cast iron
GB/T 9239 (all parts) Mechanical vibration - Rotor balancing
GB/T 9439-2010 Grey Iron Castings
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace
QC/T 556 Automotive brake temperature measurement and thermocouple
3 Terms and definitions
The following terms and definitions apply to this document.
3.1 Mounting spigot hole
A center hole which mates with the hub.
3.2 Mounting surface
The surface of the brake drum which fits the hub.
3.3 Limiting wear size
The maximum radial size allowed after the friction surface of brake drum is worn. 4 Classification
4.1 Classification of brake drum
the thermal fatigue test in accordance with A.4.1.1, shall not fail.
126.96.36.199 Brake drum samples for type M2, M3, N2, and N3 vehicles shall be tested in accordance with A.4.1.2. It shall meet one of the following requirements: a) The number of thermal fatigue test cycles when the brake drum sample fails is greater than or equal to 300;
b) When the number of thermal fatigue test cycles when the brake drum
sample fails is greater than 250, but less than 300, the test is repeated using a new brake drum sample. The number of thermal fatigue test cycles of both samples is greater than 250.
5.9.2 High load test
Brake drum samples, after completion of the high load test in accordance with A.4.2, shall not fail.
6 Inspection methods
6.1 Mechanical properties
6.1.1 Tensile strength
Samples for tensile strength shall be taken from the middle of the friction surface of brake drum. The sampling position is shown in Figure 3. If there are special requirements, it can be agreed between the supplier and the purchaser. The testing method of tensile strength shall be in accordance with the provisions of GB/T 228.1.
Figure 3 -- Schematic diagram of sampling position of sample for tensile strength
In the case where the tensile strength sampling size is limited, the wedge pressure strength can be used instead of the tensile strength. The size of the wedge sample shall comply with the requirements of Table 6. For the
conversion method of wedge pressure strength and tensile strength, see
Appendix D of GB/T 9439-2010. The wedge pressure strength is the average Sampling position
Bench test methods of brake drum
This appendix specifies the test related requirements, failure criteria, and test methods for the bench tests such as thermal fatigue test and high load test of brake drum.
A.2 Test related requirements
A.2.1 Moment of inertia
The actual inertia setting shall be as close as possible to the theoretical inertia. The deviation shall be within the range of ??5% of the theoretical inertia. The theoretical inertia refers to the inertia distributed on the corresponding wheel of the total inertia generated when the vehicle is braked. It shall be calculated according to formula (A.1).
I - Moment of inertia, in kilograms of square meters (kg ?€? m2);
m - Test mass (the mass of the vehicle?€?s maximum design total mass distributed on the corresponding wheel when braking), in kilograms (kg);
r - Tire rolling radius, in meters (m).
A.2.2 Test mass
A.2.2.1 For vehicles with a maximum design total mass of less than 7500 kg, the test mass shall be calculated according to formula (A.2) or formula (A.3). Where:
b) The hydraulic brake is 25 MPa/s??5 MPa/s.
A.2.5 Sampling rate
The sampling rate of brake line pressure and braking torque shall be greater than 20 Hz.
A.2.6 Temperature measurement
The thermocouple mounting position is at the center radius of the friction track of brake lining contact surface. The temperature measurement shall meet the requirements of QC/T 556.
A.2.7 Sample and other brake requirements
The test shall use a new brake drum and a new brake lining. The friction surface of brake drum shall be clean. Brake linings and other brake parts shall be original parts. There is no grease or other foreign matter on the brake lining surface. During the test, the brake lining, when worn to the limit, is allowed to be replaced.
A.3 Sample failure criteria
During the bench test, when one of the following phenomena occurs on the brake drum, it is determined that the brake drum sample has failed.
a) The crack length of friction surface of brake drum exceeds two-thirds of the width of the friction surface of the brake drum;
b) The crack on the friction surface of brake drum reaches the outer edge of the friction surface of brake drum;
c) The brake drum has a penetrative crack;
d) In any area outside the friction surface, there are any types of structural damage or cracks.
A.4 Test methods and test conditions
A.4.1 Thermal fatigue test
A.4.1.1 Brake drum for type M1 and N1 vehicles
The test methods and test conditions of the brake drum for type M1 and N1 vehicles are shown in Table A.3.