statement
This article is to study the technical conditions of GB-T 24748-2023 reciprocating internal combustion engine flywheel. The study notes are compiled and shared in the hope that more people will benefit. If there is any infringement, please contact us in time.
1 Scope
This document specifies the technical requirements, inspection methods, inspection rules, marking, packaging, transportation and storage of reciprocating internal combustion engine flywheels.
This document applies to
reciprocating internal combustion engine flywheels (hereinafter referred to as flywheels) with a cylinder diameter of 200 mm or less (inclusive).
2 Normative reference documents
The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, for dated referenced documents
, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.
this document.
GB/T 197—2018 Ordinary thread tolerances
GB/T 1095—2003 Cross-sectional dimensions of flat keyway
GB/T 1184—1996 Shape and position tolerances without tolerance values
GB/T 1348—2019 Ductile iron castings
GB/T 1800.1—2020 Product Geometric Technical Specification (GPS) Linear Dimensional Tolerance ISO Code System
Part 1: Tolerances,
The basis of deviation and fit
GB/T 1804-2000 General tolerances Tolerances for linear and angular dimensions without tolerances noted
GB/T 1958 Product Geometric Specification (GPS) Geometric Tolerance Detection and Verification
GB/T 2828.1 Enumeration sampling inspection procedures Part 1:
Batch-by-batch inspection sampling plan retrieved by acceptance quality limit (AQL)
GB/T 2829 Periodic inspection counting sampling procedures and tables (applicable to inspection of process stability)
GB/T 3177 Product Geometric Specification (GPS) Inspection of Smooth Workpiece Dimensions
GB/T 3821 Cleanliness limits and determination methods for small and medium power internal combustion engines
GB/T 6060.1—2018 Surface roughness comparison sample Part 1: Casting surface
GB/T 6060.2 Surface roughness comparison sample grinding, turning, boring, milling, inserting and planing surface
GB/T 6414—2017 Casting dimensional tolerances, geometric tolerances and machining allowances
GB/T 7216-2009 Metallographic examination of gray cast iron
GB/T 9239.1 Mechanical vibration constant (rigid) rotor balance quality requirements
Part 1: Inspection of specifications and balance tolerances
GB/T 9439—2010 Gray iron castings
GB/T 9441—2021 Metallographic examination of ductile iron
GB/T 11351—2017 Casting weight tolerance
GB/T 30512 Requirements for banned substances in automobiles
JB/T 7945.1 Test methods for mechanical properties of gray cast iron Part 1: Tensile test
JB/T 9744 Magnetic particle testing of internal combustion engine parts and components
JB/T 11323 Reliability Assessment Method for Small and Medium Power Diesel Engines
QC/T 484—1999 Automobile paint coating
GB/T 24748—2023
3 Terms and definitions
There are no terms or definitions to be defined in this document.
4 Technical requirements
4.1 General requirements
The flywheel shall be manufactured in accordance with the product drawings and technical documents approved through prescribed procedures, and shall comply with the provisions of this document or technical documents.
4.2 Materials and metallographic structure
4.2.1 The flywheel should be made of HT250 and above grade gray cast iron specified in GB/T 9439-2010 or
QT400-15 and above grade ductile iron specified in GB/T 1348-2019
. Its mechanical properties should comply with the corresponding standards or product drawings. Provisions. It is allowed to be
made of other materials with mechanical properties not lower than HT250 or QT400-15.
4.2.2 The tensile strength and other mechanical properties of the flywheel should comply with
the provisions of GB/T 9439-2010 or GB/T 1348-2019 or product drawings.
4.2.3 The hardness of the gray cast iron flywheel should comply with GB/T 9439-2010
or the product drawings; the hardness of the ductile iron flywheel should comply with
According to the provisions of GB/T 1348-2019 or product drawings, the hardness difference of the same flywheel should not be greater than 30 HBW.
4.2.4 The metallographic structure of the gray cast iron flywheel should comply with
the regulations of GB/T 7216-2009. The graphite distribution shape is flake, and type A, type B + a small amount of
type C graphite distribution shape is allowed to exist; the graphite length is from level 3 to 8 Grade; the matrix structure is lamellar pearlite, the number of pearlite is
grade 1 to grade 5; the number of phosphorus eutectic is grade 1 to grade 3; the number of eutectic clusters is grade 1 to grade 5, and the phosphorus eutectic content should be less than or equal to 2%, the carbide
content should be less than or equal to 2%, and the total amount of carbide and phosphorus eutectic should be less than or equal to 3%.
4.2.5 The metallographic structure of the ductile iron flywheel should comply with the regulations of GB/T 9441-2021
. The spheroidization level is level 1 to level 4, the graphite size
is level 5 to level 8, and the number of pearlite should be greater than or equal to 85%. The phosphorus eutectic content should be less than or equal to 2%, the carbide content should be less than or equal to
2%, and the total amount of carbide and phosphorus eutectic should be less than or equal to 3%.
4.2.6 The prohibited substances in the flywheel material should comply with the regulations of GB/T 30512, and the
mass percentage of P and S in the material should meet the following regulations
Determined or based on product drawings or agreed upon by both parties:
a) Gray cast iron flywheel: P≤0.08%, S≤0.1%;
b) Ductile iron flywheel: P≤0.08%, S≤0.03%.
4.2.7
If the supplier has special requirements, the material and metallographic structure of the flywheel should be as specified in the product drawings and technical documents.
4.3 Casting requirements
4.3.1 The surface of flywheel castings should be free of sand, burrs, flash and seams.
4.3.2 The dimensional tolerance of castings should not be lower than the DCTG
level 10 regulations in GB/T 6414-2017. If there are special requirements, the product drawings or relevant technical requirements can be followed.
4.3.3 The surface roughness of castings should not be lower than the Ra25 requirements in GB/T 6060.1-2018.
4.3.4 The weight tolerance of castings should not be lower than the requirements of MT9 level in GB/T11351-2017.
4.3.5 Defects and repairs of castings should comply with the following regulations:
a) Castings should not have casting defects that affect performance, such as cracks, cold shuts, shrinkage cavities, and slag inclusions;
b) Surface defects within the range of machining allowance are allowed on the machined surface of castings;
c)
The type, scope, and quantity of defects allowed on the non-machined surface of the casting and inside the casting should comply with the regulations in the product drawings or technical documents.
GB/T 24748—2023
Determined or agreed upon by both supply and demand parties;
d)
If the casting has looseness, cracks, slag inclusions and other casting defects that reduce the structural strength of the casting or the cutting and positioning clamping, repair
welding should not be used to remedy it.
4.3.6
Flywheel castings should be rust-proofed after shot blasting. The specific requirements are specified in the product drawing or agreed upon by both the supplier and the buyer.
4.3.7
The color of the unprocessed surface coating should comply with the product drawings or as agreed between the supplier and the buyer. The coating surface should be smooth and beautiful; if there are no special
provisions, the coating quality index should comply with the TQ5 regulations in QC/T 484-1999.
4.4 Dimensional tolerances of processed parts
4.4.1 Taper hole fit
4.4.1.1 The dimensional tolerance of the flywheel generator should not be lower than
the IT8 level accuracy specified in GB/T 1800.1-2020.
4.4.1.2 The dimensional tolerance of the pulley should not be lower than
the IT8 level accuracy specified in GB/T 1800.1-2020.
4.4.1.3 The keyway width dimensional tolerance should adopt
the limit deviation of "hub JS9" or "wheel and hub P9" in Table 1 of GB/T 1095-2003.
4.4.1.4
The dimensional accuracy of the flywheel taper hole should comply with the product drawings. When using a special plug gauge to detect the time line, the large end of the taper hole should be exposed 0
mm~1mm; when using the coloring method to detect the taper hole fitting surface, the taper hole fit should be greater than 70%. .
4.4.2 Shaft hole fit
4.4.2.1 It is recommended that the flywheel shaft hole be made of a base shaft made with a level 7 precision transition fit not lower than that specified in GB/T1800.1-2020
plus positioning pins and
Tighten the bolts.
4.4.2.2 The dimensional tolerance of the flywheel positioning pin hole should not be lower than
the IT8 level accuracy specified in GB/T 1800.1-2020.
4.4.2.3 The unspecified dimensional tolerances of the flywheel processing parts shall be in accordance with
the tolerance level roughness level C in GB/T 1804-2000.
4.4.2.4
The dimensional tolerance of the shaft hole of the flywheel assembly after the flywheel ring gear and flywheel are heat-sleeved shall comply with the provisions of the product drawing or technical document.
4.5 Shape and position tolerances of processed parts
4.5.1
The coaxiality of the rotation axis mated with the inner hole of the flywheel generator to the axis of the flywheel taper hole (shaft hole) shall not be lower than GB/T
1184-1996
Level 9 accuracy specified in Table B.4.
4.5.2 The coaxiality of the rotation axis mated with the pulley to the axis of the flywheel taper hole (shaft hole) should not be lower than that
specified in GB/T 1184-1996
Level 10 accuracy specified in B.4.
4.5.3 The circular runout of both ends of the flywheel rim facing the axis of the flywheel taper hole (shaft hole) should not be less than that
specified in Table B.4 of GB/T 1184-1996
Level 9 accuracy.
4.5.4 The circular runout of the outer circle of the flywheel relative to the axis of the tapered hole (shaft hole) should not be lower than the
level 9 accuracy specified in Table B.4 of GB/T1184-1996.
4.5.5 The symmetry of the keyway width with respect to the axis of the tapered hole (shaft hole) should not be lower than the
level 9 accuracy specified in Table B.4 of GB/T 1184-1996.
4.5.6 The accuracy of the thread connecting the pulley (clutch) should not be lower than the level 6 accuracy specified in GB/T 197-2018.
4.5.7 The circular runout of the contact surface between the flywheel and the clutch should be less than or equal to 0.015 mm.
4.6 Surface roughness of processed parts
4.6.1 The surface roughness Ra of the tapered hole (shaft hole) should be less than or equal to 3.2μm.
4.6.2 The surface roughness Ra of the keyway should be less than or equal to 6.3μm.
4.6.3 The surface roughness Ra of both end faces should be less than or equal to 3.2μm.
4.6.4 The remaining parts should comply with product drawings and technical documents.
4.7 Flywheel markings
The flywheel with a tapered hole matching structure should be marked with top dead center, valve phase, oil supply angle and marks. The markings and fonts of each mark should be clear and their positions should be clear.
GB/T 24748—2023
Should comply with product drawings.
4.8 Imbalance quantity
4.8.1 Static equilibrium
The allowable remaining unbalance amount Ue of the flywheel should comply with the provisions of the product drawing, or according to the
requirements of GB/T 9239.1, according to the balance quality level
The allowable residual unbalance degree eper is determined by G and operating speed n, and the value is obtained when the flywheel mass is m.
4.8.2 Dynamic balancing
According to product drawings or agreed upon by both parties.
4.9 Reliability
The flywheel reliability should meet the host requirements.
4.10 Overspeed test
After the flywheel or flywheel ring gear assembly undergoes an overspeed test, the flywheel and ring gear should not have defects such as cracks, ruptures, or bursts. Or according to product drawing specifications
Determined or agreed upon by both supply and demand parties.
4.11 Cleanliness
According to product drawings or agreed upon by both parties.
4.12 Appearance quality
4.12.1
Remove sharp edges and burrs from the flywheel signal teeth or signal holes. There should be no casting or processing defects or bumps on the edges of the signal teeth or signal holes.
Bruised.
4.12.2 The machined flat surfaces, positioning holes, screw holes, and smooth holes at both ends of the flywheel should not have any casting defects.
4.12.3 There should be no scratches, bruises or rust on the processed surface.
5 Inspection methods
5.1 Mechanical property test
5.1.1
The tensile strength test shall be carried out in accordance with the provisions of JB/T7945.1 , and the remaining mechanical property requirements
shall be carried out in accordance with the provisions of GB/T 9439-2010 or GB/T 1348-2019 according to the material.
5.1.2 The tensile strength test specimen should be from the same heat as the flywheel sample, and should be
measured with a specimen processed from a single cast test bar with a diameter of 30 mm.
The tensile strength of the flywheel material.
5.1.3
After negotiation between the supplier and the buyer, the tensile strength of the sample cut from the casting can also be used as the basis for acceptance. The sampling location is the position of the casting that has been agreed upon by both parties. The dimensions of the
gray cast iron flywheel body test bar are in accordance with GB/T 9439-2010.
According to the regulations, the test bar dimensions of the ductile iron flywheel body
According to the provisions of GB/T 1348-2019, or determined by negotiation between the supply and demand parties.
5.2 Hardness
Gray iron castings shall be manufactured in accordance with the provisions of GB/T 9439-2010; ductile iron castings
shall be manufactured in accordance with the provisions of GB/T 1348-2019. generally
Points are taken on the machined surfaces at both ends of the flywheel or determined by negotiation between the supplier and the buyer.
GB/T 24748—2023
5.3 Metallographic structure
Gray iron castings shall be inspected in accordance with the provisions of GB/T 7216-2009. Ductile iron castings
are inspected according to the regulations of GB/T 9441-2021
test. When sampling on the flywheel, the sampling location shall be
within 3 mm close to the outer circle of the flywheel or determined by negotiation between the supplier and the buyer.
5.4 Casting surface quality
Visual inspection. If the purchaser has special requirements, the surface quality of the castings can be inspected by non-destructive testing, and the inspection method is in accordance with the provisions of JB/T
9744
implement.
5.5 Coating quality
Test according to QC/T 484-1999.
5.6 Dimensional tolerances of processed parts
5.6.1 Processing dimensional tolerance
According to the provisions of GB/T 3177
, use measuring instruments that meet the accuracy level or uncertainty or maximum allowable error for testing.
5.6.2 Dimensional accuracy of the taper hole and fit of the taper hole
Use special plug gauge and coloring method to detect.
5.6.3 Thread accuracy
According to the provisions of GB/T197-2018, use the corresponding thread gauge to detect.
5.7 Shape and position tolerances of processed parts
Tested according to the provisions of GB/T 1958.
5.8 Surface roughness
The roughness of the processed surface shall be measured with a surface roughness meter, or a table shall be used in accordance with the provisions of GB/T 6060.1-2018 and GB/T 6060.2
Surface roughness comparison sample comparison method detection.
5.9 Imbalance quantity
5.9.1 Static equilibrium
Carry out static balance test according to the provisions of GB/T 9239.1.
5.9.2 Dynamic balancing
Use a special dynamic balancing machine to inspect.
5.10 Reliability
According to the provisions of JB/T11323, the assessment will be carried out along with the host computer.
5.11 Overspeed test
5.11.1
Install the flywheel or flywheel ring gear assembly with a disposable connector on a special flywheel overspeed test bench with safety protection device
GB/T 24748—2023
Make the connection between the flywheel and the test bench consistent with the connection between the flywheel and the supporting engine.
5.11.2
Start the power of the special flywheel overspeed test bench to make the flywheel/flywheel ring gear assembly reach the rated speed of the matching engine. After running smoothly for
1 minute
, quickly increase the speed of the flywheel/flywheel ring gear assembly to the limit of the flywheel/flywheel ring gear assembly. speed or
twice the rated speed of the supporting engine, and run continuously for 2 minutes.
5.11.3 If there are other special requirements, they shall be determined through negotiation between the supplier and the buyer.
5.12 Cleanliness
Carry out in accordance with the provisions of GB/T 3821.
5.13 Appearance quality
Visual inspection.
6 Inspection rules
6.1 Type inspection
6.1.1 Type inspection should be carried out under one of the following circumstances:
a) New products are put into production or old products are transferred to factories for production;
b) If there are major changes in structure, materials, and processes during normal production, product performance may be affected;
c) Once every 5 years during normal production;
d) Products that have been out of production for a long period of one year or more are resumed.
6.1.2 Type inspection items are specified in Table 1.
Table 1 Inspection items
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GB/T 24748—2023
Table 1 Inspection items (continued)
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6.2 出厂检验
6.2.1
每件飞轮均需进行出厂检验。合格后方可出厂，产品出厂应附有合格证或合格标记。
6.2.2 出厂检验项目按表1的规定。
6.3 抽查检验
6.3.1 主要用于产品鉴定、市场抽查、日常监督及订货抽检。
6.3.2 抽查检验项目按表1的规定。
6.4 抽样方案
6.4.1 制造厂定期抽样方法应按GB/T 2828.1 和 GB/T 2829
的规定进行，抽检项目按表1。
6.4.2 需方抽查产品时，应按 GB/T2828. 1
的规定抽检，检验项目、组批原则、抽样方案、判定与复验规
则按制造厂与客户商定的技术文件。
GB/T 24748—2023
6.4.3 国家主管部门抽查产品质量时，按主管部门批准的实施细则执行。
延伸阅读
更多内容 可以 GB-T 24748-2023 往复式内燃机 飞轮 技术条件. 进一步学习