The original NJ 36-85 will be invalidated from the date of implementation of this standard. This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of cylinder head gaskets for internal combustion engines. This standard is applicable to cylinder head gaskets for medium and small power internal combustion engines for automobiles, tractors, engineering machinery, stationary and marine use. JB/T 7762-1995 Technical conditions for cylinder head gaskets for internal combustion engines JB/T7762-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7762-95
Internal Combustion Engine Cylinder Head Gasket
Technical Conditions
1995-06-16
Ministry of Machinery Industry of the People's Republic of China
1993-37-01Implementation
Mechanical Industry Standard of the People's Republic of China
Internal Combustion Engine Cylinder Head Gasket
Technical Conditions
Subject Content and Scope of Application
JB/T7762-95www.bzxz.net
This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of internal combustion engine cylinder head gaskets (hereinafter referred to as cylinder gaskets). This standard is applicable to the cylinder heads of medium and small power internal combustion engines for automobiles, tractors, engineering machinery, fixed and marine use. 2 Reference standards
GB 1105.2
JB3744
IBn3827
ZBJ90 003
ZBJ92 006
ZBJ92009
3 Terminology
3.1 Structural terminology
Internal combustion engine bench performance test methodTest methodAutomobile engine reliability test method
Reliability and durability test method for diesel engine for construction machineryDurability test method for general small gasoline engine
Technical conditions for cylinder head nuts for internal combustion engines
Technical conditions
Internal combustion engine cylinder head nuts and flywheel nuts
Diesel engine bench test assessment method
a. Basic structure: Combination of the combustion chamber hole sealing part and other parts structure, b. Main body structure; Structure of parts other than the sealing part, c.
Cross-section structure of the combustion chamber hole sealing part; The cut surface structure of the combustion chamber hole sealing part formed to effectively seal the gas, such as the cylinder gasket
Ring combustion chamber hole sealing all position surface
AA enlargement
d. Combustion chamber hole sealing part reinforcement structure; In order to significantly improve the sealing effect, the combustion chamber hole sealing part of the cylinder gasket is reinforced.
e. Guard ring: Metal ring covering the periphery of each hole of the cylinder gasket. f. Auxiliary seal: Sealing measures to compensate for the increase in the cylinder gasket sealing surface. 3.2 Material terms
a. Asbestos paper and board: paper or sheet-shaped gasket material made of heather fiber and adhesive material, approved by the Ministry of Machinery Industry on June 16, 1995
implemented on July 1, 1996
JB/T 776295
b. Asbestos rubber sheet: a sheet-shaped gasket material made by mixing asbestos fiber and rubber and other raw materials, and then heating and pressing. C. Asbestos latex sheet: a sheet-shaped gasket material made by mixing asbestos fiber as the main raw material and rubber latex as the adhesive, using a pulping machine to mix them.
d. Expanded graphite sheet: a sheet-shaped gasket material made by mechanical processing of expanded particles formed by natural flake graphite after special chemical treatment and high-temperature thermal expansion.
e. Asbestos-free material: an asbestos-free sheet-shaped gasket material composed of asbestos-free synthetic fibers, natural materials and adhesives. [. Asbestos metal composite plate: a plate-shaped composite gasket material made of asbestos rubber plate, asbestos latex plate or asbestos rubber particles on both sides of a flat or punched mild steel plate. Asbestos metal mesh composite plate: a composite gasket material with a metal mesh as the center and asbestos fiber as the main material on both sides. Expanded graphite metal composite plate: a plate-shaped composite gasket material composed of expanded graphite plate or expanded graphite particles on both sides of a punched mild steel plate.
1. Asbestos-free metal composite plate, a composite gasket material made by combining asbestos-free materials on both sides of a punched mild steel plate. 3.3 Measurement terms
a. Free state thickness, the finished cylinder gasket thickness, including the thickness of the body and the combustion chamber hole, oil hole, water hole and other sealing parts in different structures
b. Free state thickness difference: the difference between the maximum and minimum thickness of the same cylinder gasket in the free state. Pressing thickness: install the cylinder gasket between the cylinder block and the cylinder head, tighten it with the specified torque, the thickness of the cylinder gasket body and the combustion chamber hole c.
Pressing thickness difference: the difference between the maximum and minimum thickness of the same structural part of the same cylinder gasket when it is pressed. d.
Flanging width, the width of the folded part of the metal plate at the hole and outer periphery of the cylinder gasket, as shown in Figure 2. Edge width
Upper flange width
Ring width: The width on the other side of the flange width, as shown in Figure 2. Flanging width
Filling degree: The degree to which the filler fills the interior of the gasket that uses metal to cover the sealing part of the combustion chamber hole, as shown in Figure 3. The degree to which the filler fills the interior
3.4 ​​Test terms
JB/T7762—95
Pressure-sensitive paper: Test paper that can display the color intensity according to the pressure it withstands (pressure-sensitive paper can be formed by combining carbon paper and white paper, or carbonless carbon paper can be directly used as pressure-sensitive paper). b.
Joint surface leakage: Leakage from the joint surface between the cylinder gasket and the cylinder block or cylinder head. Penetration leakage: Leakage caused by the penetration of the cylinder gasket itself. Thickness measuring element: When measuring the compression thickness of the cylinder gasket, the plastic material used to correctly measure its compression degree, such as lead alloy, etc.,
Structural classification and code
4.1 Basic structure
The types and codes of the basic structure are shown in Table 1.
Main body structure
The types and codes of the main body structure are shown in Table 2.
Metal type
Composite type
Clad type
No main body type
Sectional structure of the combustion chamber hole sealing part
Basic structure
The combustion chamber hole sealing part and other parts are integrated. The combustion chamber hole sealing part and other parts are not integrated. Table 2
Main body structure
Made of metal material
Constituted of metal and non-metal composite materials
Both sides or one side of the main body are made of metal material. The combustion chamber hole, water hole, oil hole and other sealing parts are sealed by several gaskets respectively. The types and codes of the section structure of the combustion chamber hole sealing part are shown in Table 3. Table 3
Metal structure
Sub-surface structure
The cylinder gasket is composed of a flat metal plate, and the combustion chamber hole sealing part is a flat shape
The cylinder gasket is composed of a metal plate, and a return groove is provided at or near the combustion chamber hole sealing part
The cylinder gasket is composed of a metal plate, and a wave effect is provided at the combustion chamber hole sealing part
Sub-surface structure diagram
Metal structure
Replacement structure
Reinforcement structure
Auxiliary seal
Single flange
Single guard
Embedded gold
Two wire rings
Embedded plate
Double guard diagram
Double flange
The types of auxiliary seals are shown in Table 4.
Resin
Rubber
Extended
Bonded
JB/T7762-95
Continued Table 3
Rain-cutting structure
The cylinder gasket is composed of several layers of thin metal plates overlapped and
doubled, and the combustion chamber hole sealing part is covered with a gold vortex plate flange to cover the combustion chamber
hole dense injection part
Cylinder gasket is covered with metal material Combustion chamber
Hole sealing part
A metal wire ring is embedded in the combustion chamber hole sealing
Part enclosure
The combustion hole sealing part
is reinforced with a metal plate
The vicinity
To prevent direct impact of the gas The guard is damaged. The gas is red. The metal ring is embedded in the outside of the guard ring. Wrap the sealing part of the combustion chamber hole in the cylinder. Double-layer guard. Use two metal plates to wrap the combustion chamber. Hole sealing part. Create a structural break. Spray various resins or use printing, dipping and other methods to treat. Spray various rubbers or use printing, staining and other methods to treat. Formed by the extension of the guard, etc. Partially bonded metal or non-metallic materials. Partially use rings made of rubber such as silicone rubber. Partially use rings made of asbestos or other materials. JB/F7/52-95. The main materials used for cylinder gaskets are shown in Table 5. Table 5
Metallic materials
Non-metallic materials
Metal and non-metallic composite materials
Structure and material marking
Cylinder gasket structure marking
Material name
Stainless steel
Tinned steel strip
Village gasket asbestos paper and board
Asbestos rubber sheet
Asbestos latex board
Colored expanded graphite board
Asbestos-free material
Asbestos metal composite board
Asbestos metal mesh composite board
Colored expanded graphite metal composite board
Asbestos-free material composite board
The cylinder gasket structure marking is represented by various codes such as basic structure, body structure, and combustion chamber hole sealing part surface structure. Standard No.
Code for cross-section structure of combustion chamber hole sealing part (see Table 3) Code for main body structure (see Table 2)
Code for basic structure (see Table 1)
Marking example:
Integrally wrapped ordinary structure single-flange cylinder gasket: cylinder gasket Z-3-P1JB/T7762-95
Integrally composite reinforced structure double-guard cylinder gasket: cylinder gasket Z-2-Z4JB/T776295
6.2 Cylinder gasket material marking
The name of the cylinder gasket material should use the name specified by the state, and its marking should be marked according to the method specified in the relevant standards. 5
Marking example
JB/T 776295
Standard number
Material specification
Material code or name, state
Asbestos sheet for lining-1.6×1000×1000
7. Technical requirements
GB2059
Standard number
Thickness×length×width
Material name
Standard number
Thickness×strip width
Pure copper strip soft state
7.1 The product shall be manufactured according to the product drawings and technical documents approved by the prescribed procedures. 7.2 Appearance
Good processing, no cracks, scars, bumps, wrinkles, rust and other defects in the sealing part. 7.3 Dimensional tolerance and positional tolerance
7.3.1 Dimensional tolerance and positional tolerance are as specified in Table 6. Table 6 Combustion chamber density position Main body Combustion chamber hole Positioning hole Bolt hole Sleeve hole, water hole Free state thickness Free state thickness difference Pressed thickness Pressed thickness difference Free state thickness Pressed sequence Diameter or outer diameter Overwidth Size or position pad ±10% of basic size Less than 15% of basic size ±8% of basic size Less than 10% of basic size Oil hole, water hole Combustion chamber hole Positioning hole Bolt hole JB/T 7762--95
Continued Table 6
Guardian width
Position
Position
Color
Note: The size tolerance and position tolerance of bolt holes and water holes used as positioning holes shall be in accordance with the requirements for positioning holes. 7.3.2 The tolerances of the parts other than those shown in Table 6 shall be ±0.50 unless otherwise specified. 7.4 Size tolerance or position tolerance of the section filling of the combustion chamber hole sealing part
For design basis 0.50
For design basis 0.40
For design basis 0.60
When the combustion chamber hole sealing part is a wrapping structure, the filler shall fill the inside of the wrapping sealing part. When the secondary surface structure of the combustion chamber hole sealing part cannot be completely filled, the filling degree requirement shall be agreed upon by the manufacturer and the user. 7.5 Performance
7.5.1 Surface pressure distribution
When the surface pressure distribution test is carried out according to Article 8.1, the surface pressure distribution state shall be determined according to the color depth of the pressure-sensitive paper, and the contact condition of the sealing part must be good.
7.5.2 Compression thickness
When the compression thickness test is carried out according to Article 8.2, the dimensional tolerance of the compression thickness and the compression thickness difference shall meet the requirements of Table 6. 7.5.3 Adaptability
When the adaptability test is carried out according to Article 8.3, there shall be no stagnant air, oil leakage, water leakage and other phenomena caused by the quality of the cylinder gasket. 7.5.4 Reliability
When the reliability test is carried out according to Article 8.4, there shall be no leakage, oil end leakage, water leakage and other phenomena caused by the quality of the cylinder gasket. 7.6 Warranty period
If the user complies with the installation, maintenance and use rules specified in the engine manual, the cylinder head gasket shall be replaced within 12 months from the date of leaving the factory (non-automotive engines do not exceed 2000h, automotive engines do not exceed 40000km), if it is damaged or cannot be used normally due to poor manufacturing quality. 8 Test method
8.1 Surface pressure distribution test
8.1.1 Purpose
This test uses the color of pressure-sensitive paper to understand and analyze the surface pressure distribution of the cylinder head gasket when it is statically sealed under compression. 8.1.2 Conditions
a. The joint surface between the cylinder head and the cylinder block and the cylinder head should meet the requirements specified by the engine manufacturer, and the surface oil and dust should be removed, especially for engines equipped with cylinder liners. The protrusion of the upper end surface of the cylinder liner should meet the value specified by the engine manufacturer, b. The cylinder gasket used for testing shall meet the requirements specified by the manufacturer, and the surface oil and dust shall be removed and kept in good condition. The pressure-sensitive paper used for testing can be a combination of carbon paper and white paper, or carbonless carbon paper. The number of layers used can be determined according to the needs.
d. The cylinder head bolts or nuts should be inspected during the test. The quality should meet the requirements of ZBJ92006 and ZBJ92009. e.The tightening sequence and torque value of cylinder head bolts or nuts shall meet the design requirements, and the error shall be within 5% of the specified torque value, and the measured value must be below 80% of the maximum scale value of the torque wrench. 8.1.3 Measurement
JB/T7762--95
Tightening of cylinder head bolts or nuts: When installing the cylinder gasket, the threaded parts of the cylinder head bolts or nuts shall be coated with the turbo lubricant specified by the engine manufacturer and tightened with a torque wrench according to the requirements specified in Article 8.1.2e. b. Qualitative measurement plate: On the pressure-sensitive paper, punch holes at the positions of the cylinder gasket bolts and positioning holes, and install the pressure-sensitive paper on the upper, lower or any side of the cylinder gasket according to Figure 4.
After tightening the cylinder head bolts or nuts for 5 minutes, loosen the bolts or nuts in the order alternating with the tightening process, take out the pressure-sensitive gasket, separate it at a high speed, observe the color intensity, and evaluate the surface pressure distribution. Cylinder
Pressure-sensitive gasket
Cylinder gasket
Separation pressure
Cylinder parts
8.2 Compression thickness test
8.2.1 Purpose
This test is to determine the thickness of the cylinder gasket body and combustion chamber hole sealing part under the compression state with a thickness measuring element. 8.2.2 Conditions
The cylinder gasket is pressed onto the cylinder block with the cylinder head for testing. Except for the following two items, the others shall comply with the provisions of a, b, and e in 8.1.2. a. Drill a hole for placing the thickness measuring element on the measuring part of the test cylinder gasket in advance. The hole diameter is 3 to 5 mm. The surface oil and dust should be cleaned and kept in good condition. b. The material of the thickness measuring element is plastic material, its whip strength should be lower than 10HV, and the thickness should be 1.5 to 2 times the compression thickness. The thickness measuring element should not be squeezed out of the hole or stuck.
8.2.3 Measuring point
The measuring point of the main body is determined according to the requirements of the measurer. The measuring point of the combustion chamber hole sealing part is shown in Figure 5. Four points are taken at equal height at its sealing part.
Measuring point
Electrical guide
8.2.4 Measurement
Install the cylinder gasket for testing according to Figure 6, place the thickness measuring element at the measuring point, and tighten the cylinder head bolts or nuts according to the provisions of Article 8.1.3a. After tightening for 5 minutes, loosen the bolts or nuts in the same order as the tightening process, and carefully remove the cylinder head to prevent the thickness measuring elements from becoming 8
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