This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of bobbin cases for household sewing machines. This standard applies to bobbin cases for JA and JB type household sewing machines. QB/T 2143-1995 Bobbin cases for household sewing machines QB/T2143-1995 Standard download decompression password: www.bzxz.net

Light Industry Standard of the People's Republic of China
Household Sewing Machine
Subject Content and Scope of Application
Bobbin Case
QB/T21431995
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of bobbin cases for household sewing machines.
This standard applies to bobbin cases for JA and JB household sewing machines. 2 Reference Standards
GB191 Pictorial Marking for Packaging Storage and Transportation
GB/T2828 Count Sampling Procedure and Sampling Table for Batch Inspection (Applicable to Inspection of Continuous Batch) GB/T2829 Count Sampling Procedure and Sampling Table for Periodic Inspection (Applicable to Inspection of Stability of Production Process) ZBY17004 Sewing Machine Packaging
3 Product Classification
For types and dimensions, see Figure 1.
4 Technical requirements
4.1 The opening angle of the shuttle door cover should be greater than 45°.
4.2 The main dimensions should comply with the requirements of Figure 1. 4.3 When the shuttle door cover is raised to the limit position, the bottom of the shuttle door cannot jump out. 4.4 The shuttle should be able to be smoothly loaded into the shuttle core. When the shuttle door cover is raised, the bottom of the shuttle door should be able to buckle the shuttle. 4.5 After the shuttle door cover is raised, the shuttle can be smoothly loaded. After the shuttle door cover is laid flat, the bottom of the shuttle door should be able to buckle the spindle groove of the shuttle, and the shuttle can still rotate freely.
4.6 The tension of the shuttle skin pressure line should be uniform and adjustable, and the edge of the shuttle skin screw head should not be exposed from the shuttle skin countersunk hole. 4.7 The thread passing part should be smooth without sharp edges, and the outer surface should be polished (or rolled), with a roughness of 4.8. The hardness of the surface heat treatment of the shuttle sleeve should not be less than 450HV0.05, the shuttle door bottom and shuttle door cover should not be less than 400HV0.05, and the shuttle skin should not be less than 300HV0.05.
5 Test method
5.1 The opening angle of the shuttle door cover is inspected by an angle gauge. 5.2 The main dimension inspection is inspected by selecting a measuring tool with corresponding accuracy according to the tolerance grade. 5.3 Inspection of the shuttle door cover in Article 4.3: When the shuttle door cover is lifted to the limit position by hand, the shuttle door bottom cannot jump out visually. 5.4 Inspection of Article 4.4: After the shuttle is installed in the shuttle sleeve, when the shuttle door cover is lifted by hand, the shuttle door bottom should be able to buckle the shuttle visually. 5.5 Inspection of Article 4.5: After the shuttle sleeve is put into the shuttle, it is visually inspected by hand. Approved by China Light Industry General Association on October 24, 1995
Implemented on June 1, 1996
(After inserting the shuttle)
QB/T2143-1995
08+08tm
4 4. 40 *0.048
20.70±0.05
1—Shuttle door cover 2—Shuttle door bottom 3—Shuttle door spring; 4—Shuttle skin, 5—Shuttle skin screw 6—Shuttle core set 5.6 Inspection of shuttle skin thread tension: Put the shuttle with suture into the shuttle core set, lead out the suture, and inspect it by hand. The edge of the shuttle skin screw head shall not be exposed from the shuttle skin countersunk hole, and it shall be inspected by visual inspection. 5.7 The thread passing part shall be smooth without sharp edges, and it shall be inspected by hand visual inspection. The outer surface roughness shall be visually inspected by using the corresponding roughness comparison sample. In case of dispute, the roughness measuring instrument shall be used for arbitration.
5.8 Surface heat treatment hardness test: Use Vickers hardness tester to measure three points on the outer diameter surface of the shuttle core, shuttle cover, shuttle bottom and shuttle skin at any position, and take the arithmetic mean of each point.
6 Inspection rules
6.1 Ex-factory products must be inspected and qualified by the quality inspection department of the manufacturer, and can only be shipped with the inspection certificate attached. 6.2 Inspection classification
Product inspection is divided into ex-factory inspection and type inspection. 6.2.1 Ex-factory inspection
When the product is delivered, the consignee has the right to accept it according to the ex-factory inspection items specified in this standard. 6.2.2 Type inspection
QB/T 2143 --1995
If any of the following situations occurs, it is necessary to conduct a comprehensive assessment of product quality and type inspection should be carried out. a.
Trial type identification of products after transfer to another factory; when the product structure, material, or process has changed significantly, which may affect the product performance; when the product is in normal production for one month, it should be inspected periodically; when the product is resumed after a long-term suspension; when the factory inspection results are significantly different from the last type inspection; when the superior quality supervision agency proposes a requirement for type inspection. Product quality characteristics classification
Product quality characteristics classification is shown in Table 1.
Quality characteristics classification
Shuttle cover opening angle>55
Size 13 two: No. 2 mm
Size 11.80.1gmm
p4.40+g.048mm
4.2$20.70±0.05mm
Shuttle bottom cannot jump out
Shuttle bottom should be able to buckle the shuttle
Shuttle sleeve can be smoothly installed in the shuttle
Shuttle skin thread tension adjustment, the head of the shuttle skin screw shall not be exposed, the countersunk hole and the thread passing part shall be smooth without sharp edges||tt| |Surface roughness
Surface hardness after heat treatment
Surface hardness after heat treatment
Surface hardness after heat treatment
4.8Surface hardness after heat treatment
6.3 Factory inspection rules
6.3.1 Sample extraction
Shuttle sleeve ≥450HV0.05
Shuttle bottom ≥400HV0.05
Shuttle cover ≥400HV0.05
Shuttle skin ≥300HV0.05
Samples should be randomly selected from the inspection batch submitted. 6.3.2 Sampling plan and strictness
Inspection classification
The normal inspection sampling plan is shown in Table 2, the determination of strictness and its transfer rules, and the qualified quality level after transfer shall comply with the provisions of Article 4.6 of GB/T2828.
Batch range
151~280
281~500
501～1200
1201~3200
3201~10000
10001~35000
Inspection level
Sampling plan
Unqualified classification
Number of unit sample inspection items
Qualified quality level (AQL)
Sample size letter
Note: ①Unit sample is each bobbin case. QB/T2143—1995
Sample size
②Ac, R. of Class B are counted as unqualified products, and A., R. of Class C are counted as unqualified numbers. 6.3.3 Determination of whether the inspection batch is qualified or not
General inspection level
Normal inspection single sampling plan
According to the results of the sample inspection, if the number of Class B non-conforming products and Class C non-conforming products found in the sample are less than or equal to the corresponding qualified judgment number (A.), the inspection batch is judged to be a qualified batch. If the number of Class B non-conforming products and Class C non-conforming products found in the sample is greater than or equal to the corresponding non-conforming judgment number (R.), the inspection batch is judged to be a non-conforming batch. 6.3.4 Disposal of non-conforming products and non-conforming batches after inspection If non-conforming products and non-conforming batches are found during the inspection, they shall be implemented in accordance with the provisions of Article 4.12 of GB/T2828. 6.4 Type inspection rules
6.4.1 Sample extraction
Samples should be extracted from a batch or batches manufactured in this cycle and qualified by factory inspection, and it is necessary to ensure that the obtained samples can represent the manufacturing technology level of this cycle.
6.4.2 Sampling plan
The sub-sampling plan for type inspection is shown in Table 3.
Discrimination level
Sampling plan
Non-conformity classification
Number of unit sample inspection items
Non-conformity quality level (RQL)
Sample size
Note: ①The unit sample is each bobbin case. Ac
②A and R of Class B. Count as non-conformity, and Ac and R of Class C. Count as non-conformity. 6.4.3 Determination of whether the type inspection is qualified or not
--sampling planbzxz.net
According to the results of the sample inspection, if the number of Class B non-conforming products and the number of Class C non-conforming products found in the sample are less than or equal to the corresponding qualified judgment number (A.), the batch is judged to be a qualified batch; if the number of Class B non-conforming products and the number of Class C non-conforming products found in the sample are greater than or equal to the corresponding non-conforming judgment number (R.), the batch is judged to be a non-conforming batch. 6.4.4 Disposal after type inspection
Disposal after type inspection shall be carried out in accordance with Article 4.12 of GB/T2829. 7 Marking, packaging, transportation and storage
7.1 Marking
The packaging of the product shall have the following markings;
Product model:
Part name:
Manufacturing factory name;
Packing date;
Standard number,
The graphics of "Handle with care", "Afraid of moisture", and "Stacking limit" shall comply with the provisions of GB191. Inner packaging of the product
The product shall be coated with anti-rust agent before packaging, and packed in paper boxes with moisture-proof paper lined inside the boxes. Every 100 pieces of bobbin sets shall be packed in one box, and 10 boxes shall be packed in one box. If there are other requirements for the quantity and form of packaging, it can be decided by negotiation between the supplier and the ordering party. 7.3 Packaging, transportation, storage
The packaging, transportation, and storage of the product shall be carried out in accordance with the provisions of ZBY17004. Additional remarks:
This standard was proposed by the Quality Standards Department of China Light Industry Association and is under the jurisdiction of the National Sewing Machine Standardization Center. This standard was drafted by Shanghai Sewing Machine Factory No. 1. The main drafters of this standard are Wang Yonghua and Li Meidi.
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