JB/T 7881.5-1999 This standard is a revision of JB/T 7881.5-95 "Sheep Shearing Machine Blades". During the revision, only editorial changes were made according to relevant regulations, and the technical content has not changed. This standard specifies the basic dimensions and technical requirements of the standard type of moving blades and fixed blades of sheep shearing machines. This standard is applicable to standard moving and fixed blades for sheep shearing, and special-shaped moving and fixed blades can also be used as a reference. This standard was first issued in 1979 as NJ 171-79, and was first revised to GB 10937-89 on March 31, 1989, and adjusted to JB/T 7881.5-95 in April 1996. JB/T 7881.5-1999 Sheep Shearing Machine Blades JB/T7881.5-1999 Standard Download Decompression Password: www.bzxz.net

ICS65.040.20
Machinery Industry Standard of the People's Republic of China
JB/T7881.1~7881.5-1999
Sheep shearer
Published on August 6, 1999
National Bureau of Machinery Industry
Implemented on January 1, 2000
JB/T7881.5-1999
This standard is a revision of JB/T7881.5-95 "Sheep shearer blades". During the revision, the original standard was edited and 6.4 "Type inspection" was removed. Other technical contents remained unchanged. This standard replaces JB/T7881.5-95 from the date of implementation. This standard was proposed and managed by Hohhot Animal Husbandry Machinery Research Institute. The drafting unit of this standard: Hohhot Animal Husbandry Machinery Research Institute. The main drafters of this standard are Hai Yurong and Zhang Jiting. Scope
Machinery Industry Standard of the People's Republic of China
Sheepshearer-Knife
Sheepshearer-Knife
JB/T7881.5-1999
Replaces JB/T7881.5-95
This standard specifies the type, basic dimensions and technical requirements of standard moving blades and fixed blades (hereinafter referred to as moving and fixed blades) of sheep shearing machines.
This standard applies to standard moving and fixed blades of sheep shearing machines. Special-shaped moving and fixed blades can also be used for reference. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. The versions shown at the time of publication of this standard are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T1299—1985
JB/T7881.1---1999
Technical conditions for alloy tool steel
Terminology for sheep shearing machines
3 Types and basic dimensions of moving and fixed blades
3.1 Types of moving and fixed blades
a) Wide-width moving and fixed blades;
b) Narrow-width moving and fixed blades.
3.2 Basic dimensions of moving and fixed blades
The basic dimensions of moving and fixed blades shall comply with the requirements of Figures 1, 2, 3, 4 and Table 1. 19.05 x 3=57.15
Wide width moving blade
National MachinerywwW.bzxz.Net
Approved on August 6, 1999
Implementation on January 1, 2000
JB/T7881.51999
635x12=76.2
Wide width fixed blade
20.1(19.05)
Figure 3 Narrow width moving blade
b, (b,)
Narrow fixed blade
3.3 Width of narrow blade
The width of narrow blade is shown in Table 1.
4 Technical requirements
JB/T7881.5-1999
Tooth pitch×number of teeth=width
20.1×2=40.2
19.05×2=38.1
6.7×9-60.3
6.3×9=56.7
4.1 The moving and fixed blades shall be manufactured according to the product drawings and technical documents approved by the prescribed procedures. Products for export shall meet the relevant regulations of the Ministry of Foreign Trade in addition to the provisions of this standard. 4.2 The moving and fixed blades shall be made of Cr04, Cr06 or other materials with performance not lower than that. The surface roughness R of the tooth side of the moving and fixed blades is 3.2μm. 4.3
The surface roughness R of the actual working surface of the moving and fixed blade edges is 1.6μm. The surface roughness R value of the bottom surface of the fixed blade is 1.6μm, and it is polished. 4.6
The moving and fixed blades shall not have defects such as flash, burrs, chipping, and tooth loss, and shall have a smooth transition except for the cutting edge. 4.7
The surface hardness of the moving blade after heat treatment is 61~65HRC. The surface hardness of the fixed blade is 60~64HRC. After heat treatment, the moving and fixed blades are not allowed to have defects such as cracks and soft spots. After grinding the moving and fixed blades, their working surfaces should be concave in the middle, and the concave center value is 0.01~0.10mm. The cutting edges of the moving and fixed blades are sharp and shall not have decarburized layers and annealing layers. 5 Test method
5.1 Inspection of surface roughness
Use a surface roughness sample or a surface roughness measuring instrument to measure the surface roughness of any two surfaces on the actual working surface and tooth side of the moving and fixed blade cutting edges and the bottom surface of the fixed blade (two moving blades for each pair of blades are fixed), and measure a total of 10 places. 5.2 Hardness inspection
Select any two places on the moving blade, and test the fixed blade at three places a, b, and c in Figure 2 and Figure 4, measure each place 3 times, and take the average value. 5.3 Determination of blade concaveness
Put the knife flat ruler on the actual working surface of the blade edge, measure 3 times longitudinally and 1 time horizontally, and use a feeler gauge to measure the gap between the actual working surface of the blade edge and the knife flat ruler.
6 Inspection rules
6.1 The moving and fixed blades must be inspected and qualified by the inspection department of the manufacturer before they can leave the factory. 6.2 The materials of the moving and fixed blades should have a factory inspection certificate and meet the requirements of GB/T1299. 6.3 Normal inspection of the surface roughness, surface hardness, and concaveness of the wool shearing machine blade. The sampling plan and judgment rules are shown in Table 2. Batch
Sampling plan
Judgment rules
Item name
Number of items
Inspection level
Sample code
Number of samples
Note: Each sample includes two moving and fixed blades. JB/T7881.5-1999
N=281~500
Surface roughness
Surface hardness
Centerness
When the number of unqualified products inspected is less than or equal to Ac, the whole batch of products is finally judged to be accepted; when the number of unqualified products inspected is greater than or equal to Re, the whole batch of products is judged to be rejected. 7 Marking, packaging and purchase and storage
7.1 There should be a trademark in the middle of the non-working surface of the moving and fixed blades. 7.2 The moving and fixed blades should be treated with anti-corrosion when leaving the factory and packed in box type. The box should have product logo, including the following: a) manufacturer name; b) product name; c) product model; d) manufacturing date or production batch number. 7.3 The accompanying documents should include: a) product inspection certificate; b) three-guarantee certificate. 7.4 The well-packaged products should be stored in a dry, ventilated warehouse without acidic gas. 8 Quality guarantee period If the user complies with the use conditions specified in the instruction manual of the wool shearing machine, and the machine is damaged due to poor manufacturing quality within the one-year three-guarantee period, its seller, repairer, and manufacturer shall be responsible for repair, replacement, and return according to the requirements of the "Regulations on the Responsibility of Repair, Replacement, and Return of Agricultural Machinery Products".
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