JB/T 6731.1-1993 Technical requirements for carburetors for small gasoline engines
Some standard content:
J94
JB
Machine Industry Standard of the People's Republic of China
JB/T6731.1-93
Carburetor for small gasoline engines
Technical conditions|| tt||Released on 1993-07-29
Ministry of Machinery Industry of the People's Republic of China
Released
Implemented on 1994-01-01
Machinery Industry Standards of the People's Republic of China|| tt||Carburetor for small gasoline engines
Technical conditions
1 Subject content and scope of application
This standard specifies the technical conditions for carburetors for small gasoline engines, JB/T6731.1 -93
This standard applies to carburetors for small gasoline engines (hereinafter referred to as carburetors). This standard does not include carburetors for motorcycles, chain saws, and mini cars.
2 reference standards
GB1105.2
GB1147
GB2828
GB2829
JB3601
JB5135||tt| |JB/T6731.3
ZBJ91012
ZBJ94002
NJ324
3 Technical requirements
Internal combustion engine bench performance test method Test method General technical conditions for internal combustion engine| |tt||Batch-by-batch inspection and counting sampling procedures and sampling tables (applicable to inspection of continuous batches) Periodic inspection and counting sampling procedures and sampling tables (applicable to inspection of production process stability) Technical conditions for automobile carburetor measuring holes||tt| |Technical Conditions for Small Gasoline Engines
Compilation Rules for Carburetors for Small Gasoline Engines Product Names and Models Compilation Rules for Bench Performance Test Methods for Small Gasoline Engines
Methods for Determination of Cleanliness of Carburetors for Small Gasoline Engines Cleanliness Limits for Small and Medium Power Internal Combustion Engines
3.1 The carburetor and all its parts and components shall comply with the requirements of this standard and shall be manufactured in accordance with product drawings and technical documents approved through prescribed procedures.
3.2 The product name and model of the carburetor should comply with the provisions of JB/T6731.3. 3.3 The main parts and components of the carburetor of the same model, except for those that are not removable and the needle valve accessories, should be interchangeable. 3.4 The materials used in the manufacture of carburetors should meet the requirements of national standards or industry (professional or ministry) standards. Materials used for metal castings should be retested for composition.
3.5 Parts and components made of steel, iron, zinc, aluminum and other alloys should have a uniform and strong protective layer or be chemically treated to prevent corrosion. 3.6 Non-metallic parts and components should be resistant to corrosion by gasoline, kerosene, gasoline and engine oil mixtures, etc., and should ensure normal operation within a temperature range of 40 to 90°C. | | tt | Slag inclusion, corrosion and deformation, etc.
3.7.2 Each oil passage and air passage of the carburetor should be carefully cleaned and blown with compressed air. There should be no burrs to ensure smoothness and cleanliness. 3.7.3 The float and rocker arm sub-assembly should meet the specified weight and have a complete appearance; the movement of the float in the float chamber should be flexible and reliable. 3.7.4 The float should be sealed and there should be no leakage or leakage, and the leakage amount should not exceed the specified value. 3.7.5 The hole flow value and accuracy of the carburetor should comply with the relevant regulations of JB3601. Adjustable measuring holes and measuring holes of specified sizes shall comply with the requirements of relevant technical documents.
3.7.6 The oil inlet needle valve assembly should be strictly sealed. Approved by the Ministry of Machinery Industry on 1993-07-29
Implemented on 1994-01-01
1
3.8 Assembly quality requirements
JB/T6731.1-93||tt ||3.8.1 All parts and components must be cleaned before assembly, and there shall be no burrs or residues that affect product performance and assembly quality. 3.8.2 The assembly of the carburetor should comply with the provisions of the procedure, and no incorrect or missing installation is allowed. 3.8.3 All fasteners of the carburetor must be tightened according to the specified torque, and the screw heads must be intact. 3.8.4 The plunger of the plunger carburetor should be flexible in action. It should be able to fully open and close automatically under the action of the spring. When closed, the gap should comply with the requirements of the relevant drawings.
3.8.5 The throttle valve and choke valve of the throttle-type carburetor should rotate flexibly; when fully open, they should be parallel to the direction of air flow. Deviation is within ±1.5°. The peripheral clearance when the throttle is closed shall not be greater than the specified value. The choke closing time should comply with the provisions of relevant technical documents. 3.8.6 The oil inlet needle valve should move flexibly and reliably, and should not be blocked or stuck. 3.8.7 If the carburetor has other ancillary devices, it should be adjusted and tested according to the drawing requirements. 3.9 Carburetor assembly quality requirements
3.9.1 The appearance of the carburetor is clean and the parts are complete. The movable parts should be flexible to operate and must not be bumped or scratched. 3.9.2 There should be no air stagnation or leakage at the seals of the carburetor. 3.9.3 The fastening joints of the carburetor must not loosen or fall off on their own during normal use: the fasteners in the air intake must have anti-loosening measures. 3.9.4 Each linkage mechanism of the carburetor should be flexible and controllable. 3.9.5 The oil level in the float chamber of the carburetor should remain stable at the specified height under the specified oil inlet pressure, and its deviation should be ±1mm
When the engine is equipped with a gasoline pump, its oil pressure should be equal to the oil supply pressure of the gasoline pump; when gravity is used to supply oil, the oil inlet pressure shall not be less than 3.7kPa (500mm gasoline column).
3.9.6 The carburetor should be inspected for static sealing, and there should be no leakage. 3.9.7 The carburetor should be inspected for cleanliness, and its cleanliness limit should comply with the provisions of Article 2.1 "Carburetor Assembly" in NJ324. 3.9.8 After the carburetor is subjected to dynamic and hot and cold shock tests, all parts and components shall not be loose or damaged. Non-metallic parts shall not be deformed. The carburetor shall be able to ensure normal oil supply characteristics after the aging test. 3.9.9 The carburetor shall undergo a comprehensive flow performance test on a comprehensive flow plate test bench. The comprehensive flow test of the carburetor should be carried out according to the following test points: a.
idle speed condition;
b.
transition condition;
common working condition condition (economic condition) or calibration condition; e
d.
maximum power condition;
maximum torque condition.
e.
Note: The deviation of each point on the comprehensive flow characteristic curve relative to the reference value of the standard sample is: & and b are within the range of ± (18% ~ 25%), and the others are within ± Within 10% range.
3.9.10 Bench test of carburetor
The bench test of digester shall be carried out on the standard prototype. 3.9.10.1 Starting performance test: The carburetor shall ensure the engine starting performance requirements. . The use of a choke or starting device is allowed when starting. 3.9.10.2 Speed ??performance test: The carburetor should ensure stable operation under the specified fuel consumption and rapid speed. Its stabilization time is not less than 5 minutes. Opening the throttle or plunger should not stall the engine.
3.9.10.3 Transitional performance test: When the engine is no-load, slowly open the throttle or plunger from rest speed, and the speed should gradually increase accordingly. During the process of speed increase, short-term stagnation is allowed and the speed fluctuation is not greater than the specified value at eating speed, but backfire or fire is not allowed.
3.9.10.4 Transmission performance test: Regardless of whether the engine is loaded or not, when suddenly changing from one working condition to another, the engine speed should change smoothly and there should be no backfire or stalling. 3.9.10.5 No-load endurance test: Starting from rapid acceleration, the throttle or plunger speed is gradually opened, and the speed rises to the calibrated speed or a large no-load speed. The fuel consumption at no-load speed should rise evenly without stagnation or decline. 2
JB/T 6731.193
3.9.10.6 Load characteristic test; Carry out load characteristic test at the calibrated speed. At the calibrated power point, the upper deviation of the fuel consumption rate is ±5% of the specified value.
3.9.10.7 Speed ??control performance test; on engines with speed regulators, speed control performance tests should be carried out. Its performance indicators should comply with the provisions of JB5135.
3.9.10.8 External characteristics test: When the throttle or plunger is fully open, the carburetor should ensure the maximum power at the specified speed, the maximum torque at the specified speed, and the lower limit of the power deviation. It is 5%, with no upper limit. 3.9.11 The use test of the carburetor should be carried out with the supporting equipment and should comply with the provisions of relevant standards. 3.9.12 The durability and reliability assessment of the carburetor should not be lower than the relevant index requirements of the supporting main engine. And after the durability test, parts shall not be replaced, and their performance shall meet the requirements of the standard prototype. 3.9.13 The slope test of the carburetor should meet the requirements of relevant regulations. 4 Test methods
4.1 The accuracy of the test instrument shall be in accordance with GB1105.2 relevant provisions. 4.2 The sealing of the float in Article 3.7.4 of this standard should be 100% tested: submerge the float into water of 80 to 90°C. The yellow pot float must not bubble within 30 seconds and the plastic float must not bubble within 2 minutes. For rigid foam plastics The float, according to the usage conditions, shall undergo a bubble test according to the requirements of the relevant technical documents.
4.3 Article 3.7.5 of this standard shall ensure that the flow rate of each carburetor orifice shall be 100% inspected in accordance with the provisions of JB3601. 4.4 The sealing performance of the oil inlet needle valve in Article 3.7.6 of this standard should be 100% tested: on a special test bench at a water column vacuum of 10.0 to 1.0 kPa (1000 + 100 mm), seal by the self-weight of the needle valve, and the water column shall be sealed within 30 seconds. No descent allowed. The needle valve should be rotated at least 3 positions during the test. The needle valve is allowed to be soaked with gasoline before testing.
4.5 The seal inspection of the carburetor in Article 3.9.2 of this standard should be 100% pressure tested: pass in compressed air with a pressure of 19.6~39.2kPa from the carburetor oil inlet joint; When immersed in liquid, there must be no air leakage at each seal. 4.6 The oil level height of the carburetor float chamber in Article 3.9.5 of this standard should be tested on a special test bench. When the oil level height cannot be measured, the dimensions that affect the height can be tested. 4.7 According to Article 3.9.6 of this standard, the static sealing performance of the carburetor should be 100% inspected. The oil stored in the float chamber is at the specified oil level; a. Pressurize to a pressure of not less than 3.7kPa (500mm gasoline column) and let it sit for 12 hours; b. Let it stand for 12 hours without adding pressure.
Observe the osmosis situation.
Note: You can choose any one according to user requirements while ensuring product quality. 4.8 The carburetor cleanliness inspection in Article 3.9.7 of this standard shall be carried out in accordance with the provisions of ZBJ94002. 4.9 The perturbation and hot and cold shock tests of the carburetor in Article 3.9.8 of this standard should be carried out on a special test bench according to the methods specified in the relevant technical documents.
4.10 The comprehensive flow test of the carburetor in Article 3.9.9 of this standard shall be carried out in accordance with the provisions of the relevant standards. The bench test of carburetor in Article 3.9.10 of this standard shall be carried out in accordance with the relevant provisions of ZBJ91012 and JB5135. 4.11
4.12 The appearance and assembly quality of the carburetor and the inspection of Articles 3.8.5, 3.8.6 and 3.9.4 of this standard are mainly carried out through daily testing, hand feeling or special measuring tools.
4.13 The tilt test of the carburetor in Article 3.9.13 of this standard shall be carried out according to the method specified in the relevant technical documents. 5 Inspection Rules
5.1 After the product passes the inspection, the quality inspection department will issue a product certificate. 5.2 All technical requirements in Articles 3.1 to 3.6 of this standard should be inspected and accompanied by a document indicating that they have passed the inspection and acceptance. 5.3 The test items and test categories of carburetors for small gasoline engines are shown in Table 1. Depending on the test category, some of the test items can be selected.
3
Serial number
2
3
6
9
10
11|| tt||12
13
14
15
16
17
Standard document number
3.7.1.3 .7.3
3. 9. 1, 3. 9. 3
3. 9. 4
3.8
3. 9. 6
3 . 9. 7
3.9.8
3.9.9
3.9.10.1
3. 9.10. 2
3. 9.10.3|| tt||3.9.10. 4
3.9.10.5
3. 9.10. 6
3.9.10.7
3.9.11
3.9.12
3.9.13
3. 9.17
Table 1
JB/T6731.1-93
Carburetor test items for small gasoline engines and their Classification test and inspection items
Appearance quality
Assembly quality
Standing sealingbZxz.net
Cleanliness
Toggle and hot and cold shock test||tt ||Comprehensive flow test
Starting performance test
Interest speed performance test
Over-epidemic performance test
Variable speed performance test
Space teaching characteristic test|| tt||Negative characteristic test
External characteristic test
Usage test
Durability and stability test
Pouring test
Speed ??regulation performance test| |tt||Note: ①\V\ represents the inspection items that should be carried out, test category
Izuho test
V
V
V
V
V
V
V
V
V
Ink test
4
口
口
A
A
4
口
4
②\△\ represents type inspection items , reporting requirements shall be carried out according to the sampling method of GB2828. ③\\Indicates items for periodic inspection.
New product supervision can be negotiated by both parties, and the inspection items can be determined with reference to this standard
If it is specified
If conditions are not met, it can be agreed by both parties
Generally not done
Calibration point inspection according to this standard
Calibration point inspection according to this standard
Can be done randomly
Accepted when required
5.3.1 The acceptance of carburetors adopts the counting sampling procedure stipulated in GB2828 for normal inspection of the one-time sampling plan. According to the unqualified items listed in Table 2, combined with the sampling plan for quality inspection of small gasoline engine carburetor products in Table 3, the samples for type inspection It should be selected from the batches that have passed the inspection, and an evaluation conclusion should be made. When all groups are judged to be qualified, the type inspection is judged to be qualified. When any group is judged to be unqualified, the type inspection is judged to be unqualified.
Table 2 Small gasoline engine carburetor product quality unqualified classification Unqualified classification
1
2
A
Class
3
4
5
7
8
Unqualified items
Standing sealing
Pressure sealing Performance
Starting performance
Calibrated power and corresponding speed
Maximum torque and corresponding speed
Calibrated fuel consumption rate
Stable regulation rate|| tt||Speed ??fluctuation rate
say
Ming
Carburetor test for various purposes
Generally refers to the need for warm starting
General purpose mechanical Carburetor assessment
Carburetor assessment for gasoline generator sets
Unqualified classification
1
2
B
Class|| tt||c
class
5
6
8
1
2
3||tt| |4
5
6
7
Unqualified classification
item
effectiveness
inspection level||tt ||Sample number
Sample number
AQL
%
Ac
Re
JB/T 6731.193
Continued Table 2
Unqualified items
Rapid speed
Interest speed fluctuations
Rapid stable operation time
Automatic fuel Consumption
Instantaneous speed adjustment
Time required for speed stabilization
Epidemic performance
Variable speed performance
Cleanliness
Processing , assembly, appearance quality
float chamber oil level height
peripheral limit when the throttle is closed
comprehensive flow accuracy
stable speed regulation
Picking test
Said
Ming
General machine carburetor examination
Test when required
Carburetor for gasoline generator sets Examination
General-purpose carburetor examination
Special examination for carburetors for various purposes
General-purpose carburetor examination
Test when required School
Table 3
Sampling scheme for product testing of carburetors for small gasoline engines (batch N is not less than 151) A
S-1
B||tt| |0
-
B
88
s-1
B
3
40||tt| |3
4
c
7
S-1
B
3
65||tt| |5
6
5.3.2 Before the periodic inspection of the carburetor, all sample units should be inspected according to the factory inspection items. If any sample unit is found to be unqualified. The units should be replaced by the unit products normally manufactured in this period, and this situation should be included in the periodic inspection report, but it will not be used as a basis for judging whether the periodic inspection is qualified or not.
5.3.3 Clauses 3.9.7, 3.9.8, 3.9.11, and 3.9.12 of this standard adopt the method of periodic inspection and one-time sampling according to GB2829
(see Table 4) .
Table 4
Small gasoline engine carburetor trade inspection judgment 1 unqualified classification of one-time sampling plan
A
Unqualified items
Usage test
Sweetness and reliability test
Low temperature starting test
Discrimination level
Sample size
3
RQL value|| tt||100
Ac
Re
week
2 years
period
5
unqualified classification| |tt||B
1
2
Unqualified collar
Cleanliness
Motion and hot and cold shock test
JB/T 6731.193
Continued Table 4
Discrimination level
Xiangben size
-
3
RQL value||tt| |100
5.4 The AQL and RQL values, Ac and Re values ??in the sampling plan are calculated based on the number of unqualified samples. Ae
Re
2
week
period
2 months
2 years
5.5 manufacturers and users The items in the unqualified classification can be selected according to the structure and purpose of the carburetor for small gasoline engines. The AQL and RQL values ??can be agreed upon by both parties when adding or removing items. 5.6 The manufacturer and the ordering unit must jointly establish standard samples of carburetors on engines that meet technical conditions and save them separately for acceptance of product performance.
6 Marking, packaging, transportation and storage
6.1 Each carburetor should be marked with:
Manufacturer’s name or trademark;
a.||tt ||b. Product model;
e
Manufacturing date (or serial number) or production batch number. 6.2 Before packaging the carburetor, the oil stored in the float chamber should be drained. After packaging, it should be ensured that it will not be corroded, contaminated or damaged during normal transportation. 6.3 Each carburetor should be packed in waterproof oil paper or plastic bags and placed in a strong and sturdy cardboard box to ensure that it will not be damaged under normal transportation and storage conditions.
There should be one copy of the instruction manual and one copy of the inspection certificate in the cardboard box. The cardboard box containing the carburetor should be packed into the packaging box so that the cardboard box cannot shake in the packaging box for transportation. The inner wall of the packaging box should be covered with waterproof oil paper, and the total weight of each box should not exceed 30kg. A packing list should be included in the box.
The appearance of the packaging box should be marked:
6.4
a.
b.
c.
d.||tt| |e.
f.
g
Postal code, address, receiving unit;
Postal code, address, manufacturer name; product model, name|| tt||Product weight and quantity:
Gross weight: kg;
Packing year and month:
"Handle with care", "Afraid of getting wet", "Up\" and other signs. 6.5 Carburetors should be stored in warehouses that are free of harmful gases and well ventilated. Additional remarks:
This standard was proposed and managed by the Tianjin Internal Combustion Engine Research Institute, which was drafted by the Tianjin Internal Combustion Engine Research Institute. Lou Shouhua,
This standard NJ321-84 "Technical Conditions for General Small Gasoline Engine Carburetors" will be invalidated from the date of implementation 6
3. Each carburetor should be packed in waterproof oil paper or plastic bags and placed in a strong and sturdy cardboard box to ensure that it will not be damaged under normal transportation and storage conditions.
There should be one copy of the instruction manual and one copy of the inspection certificate in the cardboard box. The cardboard box containing the carburetor should be packed into the packaging box so that the cardboard box cannot shake in the packaging box for transportation. The inner wall of the packaging box should be covered with waterproof oil paper, and the total weight of each box should not exceed 30kg. A packing list should be included in the box.
The appearance of the packaging box should be marked:
6.4
a.
b.
c.
d.||tt| |e.
f.
g
Postal code, address, receiving unit;
Postal code, address, manufacturer name; product model, name|| tt||Product weight and quantity:
Gross weight: kg;
Packing year and month:
"Handle with care", "Afraid of getting wet", "Up\" and other signs. 6.5 Carburetors should be stored in warehouses that are free of harmful gases and well ventilated. Additional notes:
This standard is proposed and managed by Tianjin Internal Combustion Engine Research Institute, which is the main drafter of this standard. Lou Shouhua,
This standard NJ321-84 "Technical Conditions for General Small Gasoline Engine Carburetors" will be invalidated from the date of implementation 6
3. Each carburetor should be packed in waterproof oil paper or plastic bags and placed in a strong and sturdy cardboard box to ensure that it will not be damaged under normal transportation and storage conditions.
There should be one copy of the instruction manual and one copy of the inspection certificate in the cardboard box. The cardboard box containing the carburetor should be packed into the packaging box so that the cardboard box cannot shake in the packaging box for transportation. The inner wall of the packaging box should be covered with waterproof oil paper, and the total weight of each box should not exceed 30kg. A packing list should be included in the box.
The appearance of the packaging box should be marked:
6.4
a.
b.
c.
d.||tt| |e.
f.
g
Postal code, address, receiving unit;
Postal code, address, manufacturer name; product model, name|| tt||Product weight and quantity:
Gross weight: kg;
Packing year and month:
"Handle with care", "Afraid of getting wet", "Up\" and other signs. 6.5 Carburetors should be stored in warehouses that are free of harmful gases and well ventilated. Additional notes:
This standard is proposed and managed by Tianjin Internal Combustion Engine Research Institute, which is the main drafter of this standard. Lou Shouhua,
This standard NJ321-84 "Technical Conditions for General Small Gasoline Engine Carburetors" will be invalidated from the date of implementation 6
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.