QC/T 777-2017 English PDF (QCT777-2017)
QC/T 777-2017 English PDF (QCT777-2017)
QC/T 777-2017: The technical conditions of electromagnetic fan clutch for automobile
AUTOMOBILE INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
Replacing QC/T 777-2007
The Technical Conditions of Electromagnetic Fan
Clutch for Automobile
ISSUED ON: APRIL 12, 2017
IMPLEMENTED ON: OCTOBER 01, 2017
Issued by: Ministry of Industry and Information Technology of PRC
Table of Contents
Foreword ... 7
1 Scope ... 8
2 Normative References ... 8
3 Terms and Definitions ... 9
4 Classification of Electromagnetic Fan Clutch ... 11
5 Technical Requirements ... 11
6 Test Methods ... 16
7 Inspection Rules ... 23
8 Marking, Packaging, Transportation and Storage ... 25
The Technical Conditions of Electromagnetic Fan
Clutch for Automobile
This Standard specifies the technical requirements, test methods, inspection rules, markings, packaging, transportation and storage of electromagnetic fan clutch for automobile (hereinafter referred to as electromagnetic clutch).
This Standard is applicable to electromagnetic clutch for automobile, which is mainly used in engine cooling system of automobile; electromagnetic clutch used with other internal combustion engines can be referred to.
2 Normative References
The following documents are essential to the application of this Standard. For the dated documents, only the versions with the dates indicated are applicable to this Standard; for the undated documents, only the latest version (including all the amendments) are applicable to this Standard.
GB/T 191 Packaging – Pictorial Marking for Handling of Goods
GB/T 2423.37 Environmental Testing for Electric and Electronic Products - Part 2: Test Methods - Test L: Dust and Sand
GB/T 2423.38 Environmental Testing for Electric and Electronic Products - Part 2: Test Methods – Test R: Water Test Methods and Guidelines
GB/T 2828.1 Sampling Procedures for Inspection by Attribute – Part 1: Sampling Schemes Indexed by Acceptance Quality Limit (AQL) For Lot-by-Lot Inspection GB/T 12679 Motor Vehicles – Durability Running – Test Method
GB/T 13306 Plate
GB/T 13384 General Specifications for Packing of Mechanical and Electrical Product
GB/T 17619 Limits and Methods of Testing for Immunity of Electrical / Electronic Sub-Assemblies in Vehicles to Electromagnetic Radiation
GB/T 18655 Vehicles Boats and Internal Combustion Engines - Radio Disturbance Characteristics - Limits and Methods of Measurement for the Protection of on- Board Receivers
GB/T 4942.1 Degrees of Protection Provided by the Integral Design of Rotating Electrical Machined (IP Code)-Classification
GB/T 4942.2 Low Voltage Electrical Enclosure Protection Class
JB/T 4159 General Technical Requirements of Electric Products for Tropical Environment
QC/T 238 Storage and Preservation for Automotive Parts
QC/T 29106 Technical Specification of Low-Voltage Electric Harness for Motor Vehicles
QC/T 413 Basic Technical Requirements for Automotive Electric Equipment QC/T 625-2013 Metallic Coatings and Conversion Coatings for Automobiles 3 Terms and Definitions
For the purpose of this Standard, the following terms and definitions apply. 3.1 Engaged temperature
The temperature of the cooling medium when controlling the combination of electromagnetic clutch driving disc with the driven disc.
3.2 Disengaged temperature
The temperature of the cooling medium when controlling the separation of the electromagnetic clutch driving disc from the driven disc.
3.3 Engaged state
At the engaged temperature, the combined state of the electromagnetic clutch driving disc with the driven disc.
3.4 Disengaged state
At the disengaged temperature, the separated state of the electromagnetic clutch driving disk from the driven disk.
3.5 Engaged gap
The distance between the driving disk and the driven disk when the electromagnetic 3.15 Disengaged voltage
When the circuit is on, the voltage when the electromagnetic clutch driving disc disengages from the driven disc.
3.16 Single stage electromagnetic clutch
The electromagnetic clutch, by turning on/off a winding circuit, that combines or separates the driving disc and the driven disc.
3.17 Multistage electromagnetic clutch
The electromagnetic clutch, control multiple sets of winding circuits on/off in order, that realizes the multiple working states of the driving disc and driven disc, such as from follow operation, non-synchronized operation to synchronized operation or stepwise separation from the driving disc.
4 Classification of Electromagnetic Fan Clutch
4.1 It can be divided into two types of with and without brush according to the structure. 4.2 It can be divided into two types of single stage and multistage according to the work shift.
4.3 It can be divided into two voltage specifications of 12V and 24V according to the rated voltage.
5 Technical Requirements
5.1 General requirements
5.1.1 The product shall be manufactured according to the product drawings and technical documents approved by the prescribed procedures, and shall conform to the provisions of this Standard.
5.1.2 The product drawings and technical documents of the electromagnetic clutch shall specify: product model, rated voltage, initial static friction torque, performance parameters of electrical components, rotation direction and tightening torque of mechanical fasteners, etc.
5.1.3 The product is not allowed to have defects that affect the performance. The parts of the electromagnetic clutch are not allowed to have defects such as burrs, damage, rust, cracks, etc.
1min without breakdown.
5.2.9 Insulation heat resistance.
The insulation heat resistance of the electrical components of the electromagnetic clutch must be no lower than Class F; and the temperature rise of the winding coil shall be no greater than 65 °C.
5.2.10 Electromagnetic radiation immunity.
The electromagnetic radiation immunity of the electrical components of the electromagnetic clutch shall conform to the relevant provisions of GB/T 17619. 5.2.11 Electromagnetic disturbance.
The electromagnetic disturbance of the electrical components of the electromagnetic clutch shall conform to the relevant provisions of GB 18655.
5.2.12 Vibration resistance.
The electromagnetic clutch assembly shall be able to withstand the sweep frequency vibration test in the three directions of X, Y, and Z; and the test time in each direction is 8h. After the vibration test, the parts are not damaged or deformed, the fasteners are not loose, and the electrical contacts and conductor insulation are intact. Their performance shall conform to the provisions of 5.2.2 and 5.2.4.
5.2.13 Temperature resistance.
After the temperature resistance test of the electromagnetic clutch is completed, the torque shall conform to the relevant provisions of 5.2.2.
5.2.14 Overspeed performance.
After testing in accordance with the method specified in 6.14, the parts shall be free of damage and deformation; the performance shall conform to the provisions of 5.1.2 and 5.1.3.
5.2.15 Surface protection performance.
18.104.22.168 The exposed part of the electromagnetic clutch (except the friction parts) made of ferrous metal shall be coated with anti-corrosion protective layer according to QC/T 625-2013.
22.214.171.124 The appearance of the coated and chemically treated parts shall be no lower than the Class-2 requirements of the grading method for the appearance quality of electroplated and chemically treated parts specified in 2.4.1 of JB/T 4159. 6.2.2 Static friction torque after pull-in.
After the electromagnetic clutch pull-in, it indicates the static friction torque value after reaching the maximum torque value and keep stable.
6.3 Detection of impact of operating voltage fluctuation on speed
The electromagnetic clutch assembly is installed on the platform and drives the fan to run. The voltage fluctuation in the winding is adjusted to be within the specified range. For the single stage electromagnetic clutch, separately measure the speed of driving disc and fan. For the multistage electromagnetic clutch, separately measure the speed of driving disc and driven disc and fan.
6.4 Detection of engaged gap
Use the gauge to measure the engaged gap between the driving disc and the driven disc of the electromagnetic clutch. During the measurement, the driven disc shall be rotated for 3 times so that it is at 3 different positions from the driving disc; and take the average value of the 3 results.
6.5 Speed characteristics test
6.5.1 Install the electromagnetic clutch on the performance test bench; and complete the speed characteristics test according to the provisions in the product drawings and technical requirements.
6.5.2 Accuracy level of DC power supply for test: Level-1.0, output impedance shall be no greater than 0.001Ω.
6.6 Engaged voltage test
6.6.1 The power supply voltage is set at 81.7% of the rated voltage; and test the engaged state of the electromagnetic clutch.
6.6.2 The power supply voltage is set at 81.7% of the rated voltage; and test the engaged state of the electromagnetic clutch after the thermal equilibrium is reached. 6.6.3 Adjust the engaged gap of the electromagnetic clutch to increase by 50% from the upper limit; and set the power supply voltage to 95% of the rated voltage; and test its engaged state.
6.7 Disengaged voltage test
Keep the engaged state for 15min at the rated voltage, decrease the voltage to the voltage specified in the technical drawings; and test the separation state of the driving disc and the driven disc.
The user shall perform the sampling inspection of the electromagnetic clutches in accordance with double sampling plan and inspection level II specified in GB/T 2828.1; and may also be resolved through consultation between the supplier and the purchaser. 7.3 Type inspection and determination rules
7.3.1 When the electromagnetic clutch has any of the following conditions, the manufacturer shall perform type inspection:
a) When finalizing and identifying the new product;
b) When there are major changes in the design, process and materials of the products after production, which affect the performance of the products; c) Batch, mass-produced products no less than once every two years;
d) When production is resumed production after suspending for more than one year; e) When requiring by the national quality supervision agency or customer; f) When the quality is unstable and deemed necessary to take the type inspection. 7.3.2 Type inspection shall be carried out in accordance with double sampling plan and inspection level II specified in GB/T 2828.1.
7.3.3 Items, technical requirements and test methods for type inspection shall be carried out in accordance with the provisions in Table 6.
7.3.4 The type inspection of the products shall all meet the requirements. If there are the non-conforming items, double quantities of products are allowed to be taken for the reinspection of the non-conforming items. If the reinspection is still disqualified, then such batch of products shall be determined as disqualified. However, if the durability test fails, reinspection is not allowed, and it is directly determined as disqualified.
8 Marking, Packaging, Transportation and Storage
8.1.1 Each electromagnetic clutch shall be provided with a durable nameplate fixed in a prominent position, and the nameplate shall be marked with the following: a) The name of the manufacturer;
b) Product model and name;