This standard specifies the technical requirements, test methods, inspection rules, marking, packaging and storage requirements for the moving blades and fixed blades of grass cutters and green feed choppers. JB/T 5171-1991 Grass cutter blades JB/T5171-1991 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T5171-91
Haymaker Blade
Published on 1991-05-18
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on 1992-01-01
Machinery Industry Standard of the People's Republic of China
, Blade
Haymaker
1 Subject Content and Scope of Application
JB/T5171-91
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging and storage requirements for the moving blades and fixed blades (hereinafter referred to as moving and fixed blades) of haymakers and green feed choppers. This standard applies to the moving and fixed blades of haymakers and green feed choppers used for forage processing. 2 Reference standards
GB1466
GB9439
GB1184
GB1958
GB4879
3 Technical requirements
Special section hot-rolled steel for agricultural machinery
Technical conditions for high-quality carbon structural steel
Gray cast iron parts
Shape and position tolerances
Provisions for unmarked tolerances
Metal Rockwell hardness test methods
Shape and position tolerances
Inspection rules
Rust-proof packaging
3.1 The moving and fixed blades shall comply with the requirements of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. 3.2 The moving and fixed blades shall be made of grass cutter blade steel specified in GB1466 or 65Mn steel specified in GB699. It is allowed to use other materials with mechanical properties not lower than 65Mn steel. Fixed blades can also be made of white cast iron not lower than HT200 as specified in GB9439. The cutting layer material of the double-layer moving blade should also comply with this provision. 3.3 The width of the quenching zone of the moving and fixed blades is one-third of the blade width. The hardness of the quenching zone is 45-52HRC or 52-58HRC; the hardness of the non-quenching zone shall not be greater than 38HRC.
3.4 ​​The maximum allowable value of the grinding surface roughness R of the moving and fixed blades is 6.3μm. 3.5 The cutting edges of the moving and fixed blades should be sharp and should not have defects such as decarbonization layer, soft spots, chipping, cracks, etc. The thickness of the moving blade edge shall not exceed 0.1mm. 3.6 The fixed blade body should be straight. The straightness tolerance of the blade of the moving and fixed blades with straight cutting edges should comply with the tolerance grade 12 specified in GB1184; the linear tolerance of the blade of the moving blade with curved cutting edges is 0.3-0.5mm. The cutting layer thickness of the double-layer moving blade made of double-layer steel plates or forging or welding should not be less than 1mm. 3.7
There should be no defects such as interlayer and ash inclusion at the forging and welding of the cutting layer and the blade body. The area connected as one should not be less than 85%. When a steel grass machine is equipped with two moving blades, its sharpening cycle (calculated by pure working time) should not be less than 6h; when equipped with four moving blades, it should not be less than 10h. There should be no serious tearing of the material just cut within the specified time. 3.10
The weight difference between the blades of each steel grass machine should not be greater than 2% of the design weight of the moving blade. 3.11 The shape of the blade edge of the moving and fixed blades should ensure that it is easy to sharpen. 4 Test method
Approved by the Ministry of Machinery and Electronics Industry on May 18, 1991 and implemented on January 1, 1992
JB/T5171-91
4.1 According to the provisions of GB230, at 5mm from the edge of the grinding surface of the moving and fixed blades, select four points (the first point is not recorded) at equal distances to test the hardness, see Figure 1. If one of the last three points is unqualified, it should be doubled for re-testing; if it is still unqualified, it will be judged as unqualified. The position for measuring the hardness of the non-flashing area of ​​the moving and fixed blades should be 10mm away from the flashing area. Double-layer blades should be tested on the cutting layer. Figure 1
4.2 Measurement of surface roughness parameter values
Use a surface roughness sample or a surface roughness measuring instrument to measure the surface roughness parameter values ​​of the grinding surface of the moving and fixed blades. 4.3 The measurement of the straightness and line profile error of the blade can be checked by any of the straightness and line profile detection methods specified in GB1958. 4.4 The blade angle and blade thickness should be measured on three sections at both ends of the blade not exceeding 1/10 of the blade length and at the center. Use a template or other measuring tools to draw a cross-sectional pattern on a projector with a magnification of more than 20 times for measurement, as shown in Figure 2. The blade angle can also be measured with a universal angle ruler.
Blade anglebzxZ.net
4.5 Measurement of the forged and welded area of ​​double-layer blades Use a non-destructive flaw detector to measure the area of ​​the unforged and welded parts. 4.6 Determination of the grinding cycle
The test blades should be no less than two pairs (a pair of blades is the movable and fixed blades assembled on a mower). Install the sharpened pair of blades on a well-functioning mower for hard cutting until it cannot be cut normally [the electricity output per unit length of grass shall not be less than 25kg/(kW·h·mm)], and record its pure working time. Each pair of blades shall be sharpened at least four times, and the average pure working time of the blade sharpening is calculated.
5 Inspection rules
5.1 The movable and fixed blades shall be inspected and qualified by the inspection department of the manufacturer before they can leave the factory. 5.2 The materials of movable and fixed blades shall be accompanied by inspection certificates and comply with relevant regulations. 2
5.3 Factory inspection
JB/T5171—91
5.3.1 The blades shall be submitted for acceptance in batches during factory inspection, and the batch number N=281500. The classification and sampling plan of unqualified quality are shown in the table below. The sampling plan is a one-time sampling plan for positive belt inspection. Table
Classification of non-conforming
Judgment rules
Number of items
Inspection level
Sample code
Sample size
Note: 1) Double-layer blade inspection,
Hardness of quenching area, hardness of non-quenching area
Weight difference of moving blade
Area of ​​double-layer blade connected together\
Blade edge period"
3 (4) 3)
Surface roughness
Thickness of moving blade edge
Thickness of cutting layer
Straightness or linear contour
Cutting edge angle
Blade size
6 (7))
2) The blade sharpening cycle is to be inspected once every three years. However, when the material or process of the blade is changed, it should be tested in time. 3) The number of days for double-layer blades in category A is 4; the number of days for category B is 7. 5.3.2 Judgment rules
When the cumulative number of unqualified items under inspection is less than or equal to the qualified judgment number Ac, the entire batch of blades is judged to be qualified in this category. 5.3.2.2
5. 3. 2. 3
When the cumulative number of unqualified items under inspection is greater than or equal to the number of unqualified judgments e, the entire batch of blades is judged as unqualified in this category. When the blades are judged as qualified in both categories A and B, the entire batch of blades is judged as qualified, otherwise it is judged as unqualified. Type inspection should be carried out in any of the following situations: 5.4
Trial production and identification of new products or old products transferred to the factory for production; after formal production, if there are major changes in the blade structure, materials, and processes, which may affect product performance; when the product is resumed after being discontinued for two years; when the national quality supervision agency proposes a type inspection requirement. The classification, sampling plan and judgment rules for quality unqualifiedness in type inspection are the same as those in Article 5.3. 6
Marking, packaging and storage||tt ||6.1 The blade should have the manufacturer's mark.
6.2 When the movable and fixed blades leave the factory, they should be treated with anti-rust treatment according to the provisions of M-2-1 in Table 1 of GB4879. From the date of leaving the factory, under normal management conditions, they shall not rust within one year. 6.3 Blades shipped separately should be packed in boxes. Each box shall not exceed 50kg. It can also be packaged and transported according to the agreement between the supply and demand parties. 6.4
The packaging box should indicate:
Manufacturer's name:
Product name, model and number;
Product factory date or production batch number.
JB/T517191
6.5 Each packaging box should contain the manufacturer's quality inspection certificate. 6.6 The packaged products should be stored in a dry, ventilated warehouse without corrosive gas. Quality assurance period
If the user complies with the installation and use conditions of the product, the pure working time of the blade is within 60 hours from the date of use. If it cannot work normally due to poor manufacturing quality, the manufacturer shall replace it free of charge. Additional remarks:
This standard is proposed and managed by the Hohhot Animal Husbandry Machinery Research Institute of the Ministry of Machinery and Electronics Industry. This standard is drafted by the Hohhot Animal Husbandry Machinery Research Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard is Hai Yurong.
People's Republic of China
Mechanical Industry Standard
Grass Machine Blade
JB/T5171-91
Published and distributed by the Mechanical Standardization Research Institute of the Ministry of Machinery and Electronics Industry, Postal Code 100081)
(P.O. Box 8144, Beijing
Copyright reserved
Reproduction prohibited
Printed by Printing Factory, Qinghe County, Hebei Province
Format 880×1230
Word count 8000
Sheet 1/2
First printing in September 1991
First edition in September 1991
Print count 00.001-500·Price 0.80 yuan
No. 0085
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