JB/T 50195-2000 Product reliability assessment method for small flour processing equipment
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T50195-2000
Small flour processing complete set equipment
Product reliability assessment method
(Internal use)
2000-08-18 Issued
National Machinery Industry Bureau
2000-12-01 Implementation
JB/T50195—2000
In order to implement the reliability assessment and certification of small flour processing complete set equipment products, this standard is specially formulated. Appendix A of this standard is the appendix of the standard.
This standard is proposed and managed by the National Agricultural Machinery Standardization Technical Committee. The responsible drafting unit of this standard: Shandong Agricultural Machinery Science Research Institute. The drafting units of this standard include: Henan Penguin Group Co., Ltd., Shandong Flour Machinery Factory, Henan Zhongyuan Roller Co., Ltd., Henan Xiuwu Yongle Grain Machinery Group, Henan Luohe Roller Factory, Hebei Zanhuang Machinery Factory, Anhui Wuhe Machinery Factory, Henan Nanyang Guanghui Machinery Factory, Shandong Hushan Grain and Oil Machinery Co., Ltd.
The main drafters of this standard include: Zhou Qingnong, Sun Zhongpei, Ma Nailan, Li Yunliang, Zhang Qingbo. 1 Scope
Machinery Industry Standard of the People's Republic of China
Small Flour Processing Complete Equipment
Product Reliability Assessment Method
(Internal Use)
JB/T50195—2000
This standard specifies the reliability assessment method, test method and fault judgment rules for small flour processing complete equipment products. This standard applies to the reliability assessment of small flour processing complete equipment (hereinafter referred to as flour complete equipment) products. 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 parties using this standard should explore the possibility of using the latest versions of the following standards. JB/T8838.2—2000 Test method for small flour processing equipment 3 Definition of terms
This standard adopts the following definitions.
3.1 Failure
Any phenomenon in which a flour processing equipment fails to complete its specified function or its performance drops beyond the specified range is called a failure or failure. 3.2 Intrinsic failure
A failure caused by the inherent defects of the flour processing equipment itself is called an intrinsic failure. For example, the magnetic metal content of the processed flour exceeds the specified value due to unqualified grinding materials or improper grinding wire drawing, the noise value exceeds the specified value due to improper motion parameter design or the quality of machine processing does not meet the requirements, the wind transport system cannot work properly due to improper wind network system design, the wheat cleaning effect is unqualified due to the quality of cleaning equipment not meeting the requirements, and the excessive deformation, breakage, excessive wear, bearing overheating, loose or failed fasteners, bearing oil leakage, screen leakage caused by strength material, processing and assembly are all essential faults. 3.3 Subordinate faults
The derived faults caused by the essential fault are called subordinate faults. For example, due to the damage of the rotor parts of the grading screen or the powder extraction screen, the screen silk is broken and other parts are damaged. The damage of the rotor parts is the essential fault, and the damage of other parts caused by it is a subordinate fault. For example, due to the abnormal operation of the wind transport system, it causes material drop and blockage, affects the normal operation of related equipment, and even causes machine parts damage and motor burnout. In this case, the wind transport system fault is the essential fault, and the damage of other parts and motors is a subordinate fault. 3.4 Misuse Failure
Misuse failure refers to the failure caused by the user not using and operating the machine in accordance with the instructions. For example, improper wheat tempering time and improper watering amount may cause the equipment performance to drop beyond the specified value or flour to be unqualified, or improper material flow control may cause some items to be unqualified or the equipment to not operate normally. Approved by the State Bureau of Machinery Industry on August 18, 2000 and implemented on December 1, 2000
4 Reliability assessment method
4.1 Reliability assessment index
4.1.1 Mean time before first failure MTTFFJB/T50195—2000
Wherein: MTTFF is the mean time before first failure of flour equipment, h; Number of flour equipment under investigation or test: (1)
Number of flour equipment under investigation or test that had first failure (excluding minor failures) during use or test: (2)
The cumulative working time of the ith flour equipment when the first failure occurred, h; The cumulative working time of the ith flour equipment that did not have first failure at the end of user investigation or reliability test, t
For flour equipment under reliability test, it is the timed truncation test time, h. If the flour equipment under evaluation and test does not fail within the specified time (except for minor failures), it is stipulated that MTTFF> is indicated.
4.1.2 Mean time between failures MTBF
Where: MTBF-
-Mean time between failures of flour equipment, h; Number of flour equipment under investigation or test: tei
The cumulative working time of the investigated flour equipment, and the prescribed timing cut-off time for the flour equipment under reliability evaluation test, h:
The number of failures that occurred during the use or test of the flour equipment under investigation or test (except for minor failures). If all flour equipment under test does not fail within the specified test period (except for minor failures), it is stipulated that MTBF> is indicated.
4.1.3 Reliability R
Where: R
MTBF +MTTR
Reliability, the proportion of time that the product can maintain its specified function during the reliability assessment period, %MTBF-
Mean time between failures, h:
Mean time to repair, h;
t—The repair time required for the first failure, including the sum of fault diagnosis, repair implementation and debugging time (the time from shutdown due to failure to diagnosis, repair completion, and restart of operation), h4.2 Assessment method
4.2.1 Data source
The data used for reliability assessment of flour complete sets of equipment can come from the following two aspects. 2
4.2.1.1 Usage test
JB/T50195—2000
Data obtained by reliability test in combination with production use according to the provisions of the usage test method of this standard 4.2.1.2 User survey
Reliability data of flour complete sets obtained by sampling survey among users. 4.2.2 Fault determination
For all the faults of flour complete sets, the nature and category of each fault shall be determined one by one according to the provisions of fault determination of this standard, and this shall be used as the basis for calculating relevant indicators.
5 Usage test method
The usage test method of this standard is mainly used for reliability assessment usage test of flour complete sets of equipment in batch production, and the reliability usage test of trial-produced prototypes can also be implemented as a reference.
5.1 Test prototype
5.1.1 Number of test prototypes
2 sets of flour complete sets.
5.1.2 Sampling methodWww.bzxZ.net
The sampling personnel of the reliability test unit shall supervise and randomly select qualified products produced in the factory within the past year. Considering that many parts of the flour complete set equipment need to be welded on site, at least two sets of main equipment and components of the flour complete set equipment shall be sampled in the factory (such as vibrating screen, flat rotary screen, wheat thresher, wheat washing and drying machine, dampening machine, stone remover, fan in the cleaning room equipment, milling machine, flour lifting screen, grading screen, fan, unloader and control cabinet in the flour room equipment). 5.1.3 Each test sample sent to the test site shall have the following documents and spare parts: a) Sampling registration form of flour complete set equipment;
b) Factory certificate of flour complete set equipment;
c) Instruction manual of flour complete set equipment;
d) Spare parts required by the instruction manual or relevant documents of reliability test. 5.2 Test method
5.2.1 The use conditions of the complete flour equipment shall comply with the relevant provisions of the instruction manual. 5.2.2 After the installation of the complete flour equipment is completed, it shall be idle for 15 minutes. 5.2.3 Before the flour room equipment is officially put into flour production, the skin shall be ground for 15 minutes to clean the grinding rollers, grinding chambers, screening equipment and air conveying pipeline system.
5.2.4 After the complete flour equipment has completed the idle running and the cleaning of the ground bran, the flour milling test shall begin. 5.2.4.1 The test stipulates that standard flour, special second-class flour or special first-class flour shall be processed. 5.2.4.2 During the test, the output per millimeter shall not be less than 4.0kg (am·h) when processing standard flour, and shall not be less than 3.0kgl (am·h), when processing special first-class flour, it should be no less than 2.5kg/(cm·h). 5.2.4.3 The reliability assessment time of the use test is 200h (the cumulative working time of each set of flour equipment). 5.2.4.4 During the use test, three performance tests shall be carried out in accordance with the provisions of JB/T8838.2-2000 at the initial stage (during normal operation), middle stage (after 100 hours) and late stage (near the end) of the test, and the test results shall be filled in Table 1. 5.2.4.5 Keep a record of the daily use test and fill in the working conditions of each shift in Table 2. 5.2.5 All faults occurring during the use test of the flour complete set equipment (including idling running-in, grinding of bran by equipment in the flour room and performance test) shall be recorded in detail in terms of time, situation, cause analysis, repair measures, repair working time, etc., and the category of the fault shall be determined in accordance with the relevant provisions of this standard and recorded in Table 3. 3
JB/T50195—2000
5.2.6 During the test (including performance test), general and serious faults must be eliminated before the test can be continued. 5.2.7 After the use test, fill in the comprehensive summary table of the reliability assessment test of the flour complete set equipment according to the requirements of Table 4, and fill in the summary table of the reliability assessment test results according to the requirements of Table 5. 5.3 Test report
After the test, sort out the test results and prepare a reliability test report based on the test data. The reliability test report should include the following contents:
a) The responsible unit and participating units of the test;
b) The purpose, requirements, start and end dates and locations of the test;) The main technical specifications and parameters of the flour complete set equipment: d) Test conditions:
e) Test results;
f Test conclusion.
6 Fault judgment rules
The fault judgment rules of this standard are used to analyze and evaluate the faults that occur during the use and test of the flour complete set equipment. 6.1 Fault classification
According to the degree of harm caused to the flour complete set equipment and the difficulty of troubleshooting, the faults are divided into four categories: fatal faults, serious faults, general faults and minor faults. Its categories, names, codes and descriptions are as follows: Category
Fatal failure
Serious failure
General failure
Minor failure
6.2 Judgment rules
Failures that endanger or cause personal injury or death, cause the scrapping of major components or cause major economic losses. Seriously affect the normal use of the flour complete set of equipment, or the specified important performance indicators drop beyond the specified range, and the repair cost is high. It cannot be eliminated within a shorter effective time and must be shut down for repairs
Failures that require replacement of more important parts, or dismantling the main machine to replace parts. Obviously affect the normal use of the flour complete set of equipment. The repair cost is medium. The failure can be eliminated within a shorter effective time, that is, the failure that requires replacement or repair of external parts. Slightly affect the use of the flour complete set of equipment, will not cause work interruption for the time being, and the repair cost is low, that is, the failure that can be easily eliminated with random tools in daily maintenance. 6.2.1 Reliability assessment should count the essential failures of the flour complete set. If the essential failure and the subordinate failure occur at the same time, it should be recorded once as the failure with the most serious consequences. Misuse failures are not counted in the number of failures, but should be recorded truthfully in the failure registration form. 6.2.2 When determining the type of failure of a flour mill equipment, the failure type should be determined based on the final consequences, and only one of the four types of failures should be determined.
6.2.3 Maintenance performed in accordance with the instructions for use and scheduled replacement of spare parts are not considered failure treatment, but records should be kept. 6.2.4 For failures such as oil leakage, flour leakage, bran leakage, and loose fasteners, one sealing joint surface is counted as one time when counting the number of failures. 6.2.5 After the failure is eliminated, the same failure that recurs should have its number of failures counted separately. 6.2.6 When determining the type of fault, refer to the fault examples in Appendix A (Appendix to the standard) for judgment. However, due to the different structures of various flour equipment sets, the consequences and difficulty of eliminating the same fault will vary greatly. Therefore, when actually judging the fault, it should be determined according to the definition of each type of fault, refer to the fault examples, and make judgments based on the specific situation. 4
Product model:
Prototype number:
Test location:
Test items
Flour magnetic metal objects
Power consumption per ton of flour
KW·h/t
Grinding roller output per centimeter per hour
kg/(cmh)
Maximum temperature of the material under grinding
Maximum
Temperature rise of the mill bearing ℃
Flour precision
Flour coarseness%
Flour ash (dry)
Flour gluten (wet)
Flour sand content%
Flour moisture%
Flour smell, taste
Wheat ash reduction%
Wheat broken rate%
Test participants:
JB/T50195—2000
Table 1 Summary of performance test results of flour complete set equipment Manufacturing unit:
Factory date:
Test start and end date:
Pre-test period
No. 1 Prototype
Prototype No. 2
Mid-term of test
Prototype No. 1Prototype No. 2
Late-term of test
Prototype No. 1
Prototype No. 2
Product model:
Prototype No.:
Test location:
(month, day)
Equipment operator:
JB/T50195—2000
Table 2 Shift record of reliability assessment test of flour complete set equipmentManufacturer:||t t||Factory date:
Test start date:
Working hours
Reliability assessor:
Product model:
Prototype number:
Test location:
Fault occurrence
Fault name
Equipment operator:
Reliability assessor:
Processing volume
Record:
Power consumption
Table 3 Reliability assessment test fault registration form
Manufacturing unit:
Factory date:
Test start date:
Damaged parts
Amount of damaged parts
Working time
Cause of failure
Fault troubleshooter:
Grinding roller cm
Output per hour
kg powder/
(cm·h
kw·ht
Fault troubleshooting
Cost of troubleshooting
(Yuan)
Product type No.:
Prototype No.
Cumulative idling time h
Cumulative working time h
Cumulative processing volume
JB/T50195—2000
Table 4 Comprehensive summary of reliability assessment test of complete set of flour equipment Manufacturing unit
Prototype No. 1
Cumulative maintenance time h
Cumulative repair time h
Cumulative power consumption kW·h
Average power consumption per ton of flour
kw·ht||tt ||Average milling millimeters per hour
kg/(cm·h)
Test location
Test participants
Table 5 Summary of reliability assessment test results
Product model:
Test location:
Fault category
Fatal fault
Serious fault
General fault
Minor fault
Fault accumulation
Reliability index
MTTFF-||tt| |No.1 prototype
Manufacturing unit:
Test start and end date:
No.2 prototype
No.2 prototype
Common parts
Important parts
JB/T50195—2000
Appendix A
(Appendix of the standard)
Failure examples of small flour processing equipmentFailure mode
Open welding, fracture
Important external parts of each unit
Internal fasteners of each unit|| tt||Important external fasteners of each unit
General internal parts of each unit
General external parts of each unit
Surface painting
Conveyor belt
Conveyor gear
Electrical switches, instruments
Line connectors, wires
General external fasteners of each unit
Signages of each unit
Surface painting
Conveyor belt
Air transport system
Damage or falling off
Multiple damage Damage or fall off
Impeller damage
Large area fall off
Multiple roots damaged
Individual damage or fall off
Partial fall off
Multiple roots damaged
Connection failure
Situation description
Including each main unit
Cause connection failure
Cause work interruption
No connection failure
No work interruption
Fault category
A2 performance part
Magnetic metal objects in flour
Power consumption per ton of flour
Grinding roller output per centimeter per hour
Noise in wheat room
Noise in flour room
Dust concentration
Power consumption per ton of flour
Grinding roller output per centimeter per hour
Sand content in flour
Temperature rise of mill bearings
Ash content of flour
Increase in wheat crushing rate
Reduction in wheat ash content
Sand content in flour
Main equipment of A3
Grinding mill||tt ||Grinding machine
Grinding machine
Wheat washer
Wheat thresher
Vibrating screen
Grinding machine
Grinding machine
Powder sieve
Air transport system
Air lock
Cleaning sieve
Raw grain unloader
Destoner
JB/T50195-2000
Failure mode
Exceed 0.003gkg
Greater than the specified value by 110%
1.0kg/(cm·h) lower than the standard valueMore than 95dB
More than 90dB
More than 10mg/m
100%~110% of the specified value
0.5kg/(cm·h) lower than the standard valueMore than 0.03%
More than 25℃
Exceed the specified value
Exceed the specified value
Less than 0.06%
More than 0.02% and less than 0 .03%
Failure mode
Grinding roller derails
Grinding bearing failure
Oil seeps from the bearing into the grinding chamber
Spin dryer vibrates greatly
Rotor damage
Eccentric mechanism failure
Grinding distance adjustment failure
Flow regulation failure
Brush plate, brush frame or screen frame damage
Poor unloading
Work failure
Screen damage
Work failure
Material flows on one side , stone discharge is not smooth
Situation description
Situation description
Need to recalibrate the balance
Too much suction powder
Fault category
Fault category
Mechanical industry standard
Small flour processing complete set of equipment
Product reliability assessment method
(for internal use)
JB/T50195-2000
Published and issued by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2, Shouti South Road, Beijing, Postal Code 100044)*
1/16 Printing sheet 3/4 Word count 2Q000
Format 880×1230
First edition in November 2000
Print run 1-500
First printing in November 2000
Price 1500 yuan
2000-165
Mechanical Industry Standard Service Network: http/kvwwJB.ac.cn00060cn00060cn00060
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