This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of GC medium-speed lockstitch sewing machine heads. This standard applies to GC medium-speed lockstitch sewing machine heads (hereinafter referred to as "heads") for sewing medium-thick fabrics. QB/T 1575-1992 Industrial sewing machine GC medium-speed lockstitch sewing machine heads QB/T1575-1992 Standard download decompression password: www.bzxz.net

Light Industry Standard of the People's Republic of China
GC Medium Speed ​​Lockstitch Sewing Machine Head
Industrial Sewing Machine
Subject Content and Scope of Application
QB/T 1575-1992
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of (C-type medium speed lockstitch sewing machine heads.
This standard applies to GC medium speed lockstitch sewing machine heads for sewing medium and thick fabrics (hereinafter referred to as "heads"). 2 Referenced Standards
Packaging Storage and Transportation Pictorial Labels
Technical Requirements for Natural Cotton Fabrics
GB/T 406
GB/T 2828
GB/T2829
GB/T4514
GB/T 4515
GB/T 6835
QB/T 1177
ZBY 17004
ZBY 17020
ZBY 17023
3 Product classification
3.1 Type
Batch inspection counting sampling procedure and sampling table (applicable to the inspection of continuous batches) Periodic inspection counting sampling procedure library and sampling table (applicable to the inspection of the stability of the production process) Rules for compiling sewing machine product models
Classification and terminology of stitches
Cotton sewing thread
Noise level test method
Industrial sewing machine
Marking, packaging, transportation and storage procedures of sewing machines GC high-speed lockstitch sewing machine head Sewing machine head starting torque test method
This machine head is a flat body, using connecting rod thread picking, rotary hook thread hooking, and bottom feeding to form 301 stitches (GB/T4515). 3.2 Basic parameters
a Maximum sewing speed: 3000 stitches/min; wwW.bzxz.Net
Maximum stitch length: not less than 3.6mm,
Presser foot lifting height: hand lifting not less than 6mm, knee lifting not less than 9.6mms Needle GCX1 type NM65~110;
e. Use sewing thread: 6~4tex×3-4 (42100S/3-~4), z-direction, cotton thread or polyester-cotton core-spun thread, T. Motor power: not more than 400W.
3.3 Product model representation method
According to the provisions of GB/T4514.
Example:
Approved by the Ministry of Light Industry of the People's Republic of China on August 31, 1992 254
199 3-04-01 Implementation
3.4 ​​Structural dimensions
QB/T1575-1992
Derivation number
Design sequence number
Flat-type machine body connecting rod thread take-up hook thread hook lock stitch industrial use
The machine head's external dimensions and installation connection dimensions are shown in Figure 1 (unit: mm). 8
4 Technical requirements
4.1 Appearance quality
4.1.1 The surface of the baking varnished parts should be flat and the color should be even. The main visible parts should not have obvious defects such as paint flow, blistering and paint contact. 4. 1.2 There should be no rust spots or stains on the surface of the machine head: the label should be complete, correctly positioned, and without obvious scars. 4.1.3 There should be no burrs on the exposed parts and screw heads of the machine head. 4.1.4 The surface of the blackened parts should be uniform in color and should not have defects such as blanks, light spots of sediment, scratches and rust. 4.1.5 The surface of the electroplated parts should be flat, smooth and uniform in color, and should not have defects such as missing plating, blistering, spots, scratches and rust. 4.2 Machine performance
The stitch length, thread tension and presser foot pressure should be adjustable. After the presser foot is lifted, it should be able to loosen the thread. The relative error of the stitch length of the reverse sewing should not exceed 20%. 4.2.31
4.2.4 The maximum stitch length should not be shorter than 3.6mm. 4.3 Sewing performance
The sewing test should be carried out according to the test conditions specified in Table 1. There should be no broken thread, broken needle, skipped stitch and floating thread during the test. Table 1
Test items
Backward and forward stitch
Length consistency
Maximum stitch length
Sewing material layer creep
Continuous stitch
Random!
Used sewing thread
[(GB/T6835)
Selected according to basic parameters
Medium plain cloth
(GB/T 406)
Polyester palm cloth
Medium plain cloth
(GB/T 406)
Dimensions, mm
500×90
300×50
500×100
300×50
500×100
1000×100
Sew in a ring
2-4-6-4-2
Stitch length Sewing speed
Needle/min
QB/T1575—1992
4.3.1 The creep between two layers of sewing materials should not exceed 5mm. 4.3.2 When the seam is thin, the sewing material should not be obviously wrinkled, and the wrinkling degree should not exceed the standard sample level 3. 4.3.3 Sew 5 rows of layer seams.
4.3.4 Sew 5 rows continuously.
4.4 Operation performance
4.4.1 Operation noise
When the sewing speed is 3000 stitches/min, there should be no abnormal noise; when the sewing speed is 2700 stitches/min, the noise sound pressure level is not more than 85dB (A). 4.4.2 The operation should be smooth without obvious vibration. The starting torque is not more than 0.2Nm.
4.5 Accessories and spare parts
The accessories and spare parts of each machine head should comply with the provisions of the product manual or packing list. 5 Test method
5.1 Appearance quality
At an illumination of 600±200lx and a distance of 300mm, use the visual method to judge. 5.2 Machine performance
5.2.1 Mechanism adjustment
In the "sewing performance test" project, adjust according to the method specified in the instruction manual. 5.2.2 Loose thread action
Put down the presser foot wrench, the thread take-up rod is at the highest point, thread the needle and thread according to the instruction manual, and hang it vertically after passing through the hole of the thread take-up rod. The end of the thread is tied with a magnetic code with a mass of 50g, and the presser foot is lifted and locked. Pull the needle and thread at the end of the thread pin, and tie a knot to fix the magnetic code when it is about 20mm away from the bottom plate plane. Use scissors to cut the line segment between the thread pin and the thread hook, and the magnetic code should be able to fall by itself. 5.2.3 Relative error of the length of the reverse and forward stitches
The test conditions are as specified in Table 1, and the method is as specified in Article 6.2.4 of ZBY17020. 5.2.4 Maximum stitch length
According to the test conditions in Table 1, use a vernier caliper with a range of 0~125mm and an indication of 0.02mm to measure the total length of 10 stitches on the specified seam and take the arithmetic average.
5.3 Sewing performance
5.3.1 Preparation before the test
Before the test, the machine head surface should be cleaned and lubricated. After running at 90% of the maximum sewing speed for 5 minutes, the test should be carried out item by item according to the test conditions specified in Table 1:
b. The sewing speed must be tested with a non-external contact speed meter. The sewing speed tolerance during the test is 3%; before each test, the presser foot pressure, thread tension, stitch length and feed dog height can be adjusted and trial sewing can be carried out, but no further adjustment is allowed during the formal test.
5.3.2 Creep of the seam material layer
The test method shall be in accordance with Article 6.3.6 of ZBY17020. 5.3.3 Thin sewing
Visually inspect against the standard sample after trial sewing.
5.3.4 Layer Sewing
Fold and sew the sample according to the regulations.
5.3.5 Continuous Sewing
Stack the upper and lower layers of the sample in a staggered manner, connect them end to end to form a ring (circumference 2m), and sew according to the regulations in Table 1. 256
5.4 Running Performance
5.4.1 Running Noise
a. No abnormal noise
QB/T1575-1992
Adjust the stitch length to 2mm and raise the presser foot. According to the specified sewing speed, use the ear listening method to judge; b. Noise sound pressure level
Test according to the regulations of QB/T1177.
5.4.2 Smooth operation without obvious vibration
When the maximum sewing speed is 90%, use the touch feeling method to judge. 5.4.3 Starting torque
Test according to ZBY17023.
5.5 Accessories and spare parts
Check item by item according to the product manual or packing list. 6 Inspection rules
6.1 Each machine head must be inspected and qualified by the quality inspection department of the manufacturer and accompanied by an inspection certificate before leaving the factory. The seam sample size of the continuous stitch of the machine head should be attached under the presser foot 1×b, 100mm×30mm. 6.2 The consignee has the right to conduct acceptance according to the factory inspection items specified in this standard within the acceptance period specified in the order contract. If there are other requirements, they shall be decided by negotiation between the supplier and the supplier.
6.3 Inspection classification
Inspection items, unqualified categories, and inspection classification shall be in accordance with Table 2. Table 2
Appearance quality
Machine performance
Sewing performance
Running performance
Accessories and spare parts
Factory inspection
Inspection items
4.1.1~~4.1.5
4. 2.1,4.2.2
4.2.3,4.2.4
4. 3. 2,4. 3. 3,4. 3. 4
4.4.1a,4.4.2
4.4.1b,4.4.3
Non-conforming category
Inspection category
6.3.1.1 Products are delivered in batches. The unit product is calculated as each machine head. Samples shall be randomly selected from the batch submitted for inspection. The sampling plan and strictness shall be in accordance with GB/T2828, see Table 3.
Sampling level
Sampling plan
Unqualified categories
Unit sample inspection items
Acceptable quality level AQL
Normal inspection single sampling
26~150
151～1200
Sampling level
Sampling plan
Sample code
QB/T1575-1992
Continued Table 3
Sample size
Normal inspection sub-sampling
6.3.1.2 Batch conformity judgment, Class B is calculated by the number of unqualified products, Class C is calculated by the number of unqualified products. If all are qualified, the batch is qualified, and if one of the categories is unqualified, the batch is unqualified.
6.3.1.3 The batch judged as unqualified shall be fully inspected by the silicon manufacturer. The unqualified products shall be removed or repaired and the rework record shall be attached. The products can be submitted for factory inspection again, but stricter inspection shall be used; if they are still unqualified, the batch of products shall not be submitted for acceptance again. At this time, the reasons should be analyzed, and improvement measures and treatment methods for the batch of products should be proposed. 6.3.2 Type inspection
6.3.2.1 Normal continuous production is carried out once every three cycles. When the product stops production for more than one cycle and resumes production, or when there are major changes in the design, structure, process, and materials of the product, type inspection must be carried out. 6.3.2.2 The samples shall be drawn from the products produced in this quarter and the products that have passed the factory inspection at any time. 6.3.2.3 The inspected samples shall be fully inspected according to the factory inspection items. If unqualified products are found, they shall be replaced with qualified products. At the same time, the analysis of the reasons shall be recorded in the type inspection report, and shall not be used as the basis for the identification of the type inspection results. 6.3.2.4 The sampling plan and the determination of whether it is qualified or not shall be in accordance with the provisions of GB/T2829, see Table 4. Table 4
Discrimination level
Sampling plan
Unqualified category
Unit sample inspection items
Unqualified quality level RQL
Sample size
The treatment after type inspection shall be in accordance with Article 4.12 of GB/T2829. 7 Marking, packaging, transportation, storage
7.1 Marking
The following markings shall be on the head:
Product model:
Trademark,
Manufacturer's name;
Manufacture date or number.
The following packaging, storage and transportation markings shall be on the outer packaging, and shall be marked in accordance with the provisions of GB191. Moisture-proof;
Upward,
Handle with care;
Stacking limit.
One-time sample
Packaging, transportation, storage
According to the provisions of ZBY17004.
Additional instructions:
QB/T 1575--1992
This standard is proposed by the Quality Standards Department of the Ministry of Light Industry. This standard is under the jurisdiction of the National Sewing Machine Standardization Center. This standard was drafted by Shanghai Industrial Sewing Machine Factory. The main drafters of this standard are Zheng Guohua and Zhou Yuzhu. 259
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