JB/T 51235-1999 Product Quality Classification of Stalk Choppers JB/T51235-1999 Standard Download Decompression Password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T51235-1999
Product Quality Classification of Straw Choppers and Returning Machines
(Internal Use)
Published on 1999-12-30
National Bureau of Machinery Industry
Implemented on 2000-06-01
JB/T51235—1999
This standard is a revision of JB/T51235.1~51235.394 "Product Quality Classification of Fling-type Straw Choppers and Returning Machines". Compared with JB/T51235.1~51235.3—94, the main technical content of this standard has been changed as follows: Adjusted the cutting height and effectiveness indicators: 1. Cancelled the tolerance requirements of parts.
This standard replaces JB/T51235.1-51235.3-94 from the date of implementation. This standard is proposed and managed by the National Agricultural Machinery Standardization Technical Committee. The responsible drafting unit of this standard: China Agricultural Mechanization Science Research Institute. The main drafters of this standard: Yang Juntai, Zhu Bolin. 1 Scope
Machinery Industry Standards of the People's Republic of China
Product Quality Grading of Stalk Choppers
(Internal Use)
JB/T51235-1999
Replaces JB/T512351~51235.3-94
This standard specifies the product quality indicators, test methods and inspection rules of stalk choppers. This standard applies to the product quality grading, quality inspection and grade assessment of stalk choppers (hereinafter referred to as choppers) that mainly chop corn stalks.
2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T2828—1987
GB/T5262—1985
GB/T9239—1988
JB/T5673—1991
JB/T66791993
JB/T9816—1999
Quality index
Batch inspection counting sampling procedure and sampling table (applicable to continuous batch inspection)General provisions for the determination of test conditions for agricultural machineryDetermination of the balance quality of rigid rotors and allowable imbalanceGeneral technical conditions for painting of agricultural and forestry tractors and implementsTest methods for stem choppers and returners
Chopping blades for flail choppers
Chopper products should be manufactured according to product drawings and technical documents approved through prescribed procedures, and should comply with relevant standards. Chopper products are divided into qualified products, first-class products and superior products according to their technical level and quality level. 3.3 Operation performance
3.3.1 The qualified chopped length of corn and other tall-stalk crops should be less than or equal to 100mm. 3.3.2 Under the conditions that the soil moisture content of the shredder is 15%~25%, the corn stalk yield (calculated by dry matter) is more than 12000kg/hm, and the stalks are not seriously lodged, the operation performance indicators should meet the requirements of Table 1. Table 1
Qualified rate of chopped length
Cutting height
Productivity
3.4 ​​The effectiveness should meet the requirements of Table 2.
Approved by the State Machinery Industry Bureau on December 30, 1999Qualified products
≥ 90
Excellent products
Should meet the design requirements
2000-06-01Implementation
Effectiveness
5Safety performance
Assessment work time
JB/T51235-1999
Qualified products
Excellent products
3.5.1Exposed rotating parts that are harmful to operators should have reliable protective devices and obvious safety signs. 5.5.2Safety precautions for operation, use, maintenance and repair should be given in the product manual. 3.6 Main parts and assembly quality
3.6.1 The strength grade of fasteners bearing loads in the main shaft and gearbox of the shredder shall be: bolts shall not be lower than grade 88, nuts shall not be lower than grade 8, and their tightening torque shall comply with the provisions of Table 3. Table 3
Nominal size
Tightening torque
The shredder blade shall comply with the provisions of JB/T9816. Tightening torque tolerance value
The main shaft of the shredder (including the blade holder) shall be dynamically balanced, and its balancing accuracy shall comply with the G6.3 grade specified in GB/T9239. 3.6.3
After the shredder runs idly at rated speed for 30 minutes, the temperature rise of each bearing shall not exceed 25℃. The coating of the shredder appearance shall comply with the relevant provisions of JB/T5673 and meet the provisions of Table 4. Table 4
Appearance of coating
Thickness of coating
Adhesion
4 Test method
Performance test
Qualified products
Even color, smooth and flat, no exposed bottom
Grade 2 (3 places)
4.1.1 Test preparation and field investigation
Perform according to the provisions of Chapter 4 of JB/T6679-1993. 4.1.2 Determination of qualified rate of shredded length
Perform according to the provisions of 5.3 of JB/T6679-1993. 2
Superior
Bright color, smooth, no exposed bottom, no spots, no flow marks, no bubbles, no wrinkles>55-90
Grade 1 (2 places)
Grade 2 (1 place)
【Grade (3 places)
4.1.3 Determination of stubble height
JB/T51235-1999
According to the provisions of 5.2.1 in JB/T6679-1993. 4.1.4 Determination of pure productivity
According to the provisions of 5.2.3 in JB/T6679-1993. 4.2 Determination of effectiveness
According to Appendix B in JB/T6679-1993. 4.3 Inspection of main parts and assembly quality
4.3.1 Determination of tightening torque of bolts and nuts After marking the assembly position of bolts and nuts, loosen them by about 1/4 turn, and then tighten them to the marked position with a torque wrench. The measured torque value is the tightening torque.
4.3.2 Determination of the unbalance of the chopper spindle (including the knife seat) The unbalance of the chopper spindle is measured on a dynamic balancing machine. The determination method and calculation method shall be carried out in accordance with the provisions of CBT9239. 4.3.3 Determination of bearing temperature rise
After the chopper is idle at rated speed for 30 minutes, the bearing temperature is measured on the bearing housing near the journal with a point thermometer, and the bearing temperature rise is calculated.
4.4 Determination of the paint quality of the chopper
It shall be carried out in accordance with the relevant provisions of JB/T5673.
5 Inspection rules
5.1 Sampling method
5.1.1 The sampling method adopts the provisions of GB/T2828. 5.1.2 Random sampling is conducted from the products produced in the factory in the past six months, and the number of samples is 2. Parts are sampled from the semi-finished product warehouse or assembly line, and complete machines are sampled from the finished product warehouse or sales department; when sampling in the factory, the product inventory shall not be less than 16 units (sets), and sampling in the sales department is not subject to this restriction.
5.2 Classification of unqualified items
The content and requirements of the inspection items shall comply with the provisions of Chapter 3, and all unqualified items shall be determined as unqualified items. They are divided into three categories: A, B, and C according to the degree of influence on product quality. See Table 5 for details. 5.3 Evaluation rules
5.3.1 Assess each item and determine the grade according to the item. The product grade is determined by the lowest grade reached by each group of unqualified items in the unqualified item classification table. 5.3.2 Determine the product quality grade according to the sampling judgment table 6, AQL is the quality qualification level, Ac is the qualified judgment number, and Re is the unqualified judgment number.
Classification of unqualified items
Sampling plan
Qualified products
First-class products
Superior products
JB/T51235-1999
Qualified rate of shredding length
Safety
Effectiveness
Productivity
Tightening torque of bolts and nuts
Chopping blade
Cutting height
Bearing temperature rise
Dynamic balance of chopper spindle
Appearance of coating
Coating thickness
Coating adhesion
Classification of unqualified items
Number of items
Inspection level
Sample code
Mechanical industry standard|| tt||Product quality classification of stem choppers
(for internal use)
JB/T51235-1999
Published and issued by the China Academy of Mechanical Science
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Format 880×12301/16 Printing sheet 1/2
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First edition in March 2000
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