QB/T 1574-1992 Industrial sewing machine heads for high-speed double-needle lockstitch sewing machines
Some standard content:
Light Industry Standard of the People's Republic of China
Industrial Sewing Machine High-speed Double Needle Lockstitch Sewing Machine Head Subject Content and Scope of Application
QB/T 1574--1992
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of high-speed double needle needle and bottom compound feed lockstitch sewing machines.
This standard applies to high-speed double needle needle and bottom compound feed lockstitch sewing machine heads (hereinafter referred to as "heads") for sewing medium and thick materials with flat needle bars that are not separated.
2 Reference standards
GB/T406 Technical requirements for unbleached cotton fabrics
GB/T 2828
Batch inspection counting sampling procedures and sampling tables (applicable to inspection of continuous batches)GB/T 2829
Periodic inspection counting sampling procedures and sampling tables (applicable to inspection of production process stability)GB/T2907.1
Technical requirements for unbleached cotton canvas for shoes
GB/T 4515
Classification and terminology of seams
GB/T 6835
GB/T 6837
QB/T 1177
QB/T1178
ZBY 17004
ZBY17020
ZBY17023
3 Product classification
3.1 Type
Cotton sewing thread
Polyester-cotton core-spun thread
Test method for noise level of industrial sewing machines
Test method for vibration of industrial sewing machines
Marking, packaging, transportation and storage of sewing machines GC type high-speed lockstitch sewing machine head Test method for starting torque of sewing machine head
This machine head is a flat body, with connecting rod or sliding rod taking up the thread, double needle and double rotary hook hooking the thread, needle and bottom comprehensive feeding, forming two rows of 301 type stitches (GB/T 4515).
3.2 Basic parameters
Maximum sewing speed: not less than 3500 stitches/min; Maximum stitch length: not less than 4mm;
Presser foot lifting height: hand height not less than 6mm, knee height not less than 10mm Double needle spacing: commonly used 4.8mm, 6.4mm (3/16\, 1/4\), special 2.4~~38.1mm (1/8\~1/2\); Needle used: GC×5 type Nm75~90 (Japan ORGANDP×5 type 11\~~14\ or American SINGER135×5), GC×7 type Nm110~120 (Japan ORGAN DP×7 type 18\~19\ or American SINGER135×7); f.
Used sewing thread: 14tex2×3~~9.5tex2×342s/2×3~~60S/2×3) Z-direction and S-direction cotton thread or polyester-cotton core-spun motor power: not more than 400W.
Approved by the Ministry of Light Industry of the People's Republic of China on August 31, 1992 and implemented on April 1, 1993
4 Technical requirements
4.1 Appearance quality
QB/T1574.1992
4.1.1 The surface of the baking varnish should be flat and evenly colored. 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 or stains on the surface of the head. The label is complete and in the correct position without obvious scars. 4.1.3 The exposed parts and screw heads of the machine head should not have burrs. 4.1, 4 The surface of the electroplated parts should be flat, smooth, and uniform in color. There should be no rust or peeling. The main surface should not have obvious spots, bubbles, pinholes and burrs.
4.1.5 The surface of the blackened parts should be uniform in color and should not have defects such as blanks, sediments, spots, scratches and rust. 4.2 Machine performance
4.2.1 The stitch length, thread tension, presser foot pressure, etc. should all be adjustable. 4.2.2 The maximum stitch length should not be shorter than 4mm. 4.2.3 The lifting height of the presser foot should not be less than 6mm when lifted by hand and not less than 10mm when lifted by knee. After lifting and locking, it should play a role in loosening the thread. 4.2.4 At the maximum stitch length, the starting force of the reverse feed wrench should not be greater than 20N, and the reverse feed wrench should be able to be completely reset when pressed and released. 4.2.5 The length of the backstitch stitches should be basically consistent, and the relative error of the length should not exceed 15%. 4.3 Sewing performance
When the following sewing test is carried out under the test conditions specified in Article 5.3 and Table 1, there shall be no defects such as broken needles, broken threads, skipped stitches and floating stitches. Table 1
Test items
Maximum stitch length
2 Inverted stitch stitch consistency
Through sewing
Continuous sewing
Sewing material layer creep
High and low sewing speed stitch
Long magic consistency
Used sewing thread
14tex2X3
9. 5tex2X3
(42S/2X3
60S/2X3)
130 Medium plain cloth
R size, mm|
(GB/T 406)
Shoe upper canvas
(GB/T 2907.1)
130 Medium plain cloth
(GB/T 406)
Upper cotton machine cloth
(GB/T2907.1)
Cotton thread or polyester-cotton thread
130 medium plain cloth
(GB/T 406)
Upper cotton canvas
(GB/T 2907.1)
Note: No. 5111 British density and count 822921S/2×3. 4.3.1 Alarm sewing, sewing length 1m.
4.3.2 Continuous sewing, key sewing length 5m.
4.3.3 Layer sewing, sewing length 300mm, sewing 2 times. 4.3.4 Continuous thickening 6 layers, sewing length 500mm, sewing 2 times. 1500×100
500X100
2-4-2~4~2
Stitch length mmlSewing speed, needle/min
4.3.5 Creep between two layers of sewing material: The creep between two layers of sewing material should not exceed 3.5mm within the sewing length of 500mmc4.3.6 When sewing at high and low speeds, the stitch length should be basically the same, and the relative error of the length should not exceed 15%. 4.4 Operation performance
4.4.1 Operation noise
QB/T1574—1992
When the sewing speed is 3500 needles/min, there should be no abnormal noise; a.
b. The noise sound pressure level is not more than 9OdB(A). 4.4.2 Vibration during operation
The vibration displacement value is not more than 500μum.
4.4.3 The maximum starting torque is not greater than 0.6N·m. 4.4.4 During operation, the lubrication system has good performance and no oil leakage is allowed on the joint surfaces. 4.5 Accessories and spare parts
The accessories and spare parts equipped with each machine head shall comply with the provisions of the product manual or packing list. 5 Test method
5.1 Appearance quality
Under the light of 600±200lx, the inspection distance is 300mm, and it is judged by visual inspection. 5.2 Machine performance
5.2.1 The adjustment of stitch length, thread tension and presser foot pressure shall be adjusted according to the method specified in the instruction manual in the "sewing performance test" item.
5.2.2 Maximum stitch length
According to Table 1, use a vernier caliper to measure the total length of 10 stitches on the specified seam and take the arithmetic average. 5.2.3 Presser foot lifting
a. Presser foot lifting height
Turn the upper wheel to make the feed dog lower than the needle plate plane, lift the presser foot, and it can freely pass through the 6mm special gauge under the presser foot (see Figure 1); Special gauge
Line loosening
Perform according to Article 6.2.2 of ZBY17020. 5.2.4 Starting force of the reverse feed wrench (see Figure 2) and free reset pressure
Lift the presser foot;
Adjust the stitch length to the maximum value;
Put the spring scale against the end of the reverse wrench, slowly apply force downward, and read the test value of the time when the wrench starts to move, which is the starting force; press the wrench by hand, and immediately release it. If the wrench can be reset without getting stuck, it is qualified. 5.2.5
Consistency of length of reverse and forward stitches
After sewing as specified in Table 1 and shown in Figure 3, use a vernier caliper to measure the length of 10 stitches 50 mm away from the inflection point, and calculate according to the following formula to obtain the relative error:
QB/T 1574—1992
Relative error of reverse and forward stitch length (%)=
[forward stitch length - reverse stitch length]×100forward stitch length
10 stitch lengths
5.3 Sewing performance test
10 stitch lengths
Before testing, clean the surface of the machine head, and remove dirt from the needle plate, feed dog, hook and thread passing part. After adding lubricating oil, run at 90% of the highest a.
sewing speed for 5 minutes, and then test each item according to Table 2; b. The sewing speed is tested with a non-contact measuring instrument. The tolerance of the sewing speed during the test is -3%; c.
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 adjustment is allowed during the formal test.
5.3.1 Ordinary sewing
Sew 1m according to Table 1.
5.3.2 Continuous sewing
Stagger the upper and lower layers of the sewing cloth front and back, and connect them end to end to form a ring and sew them together (circumference 2m). Sew continuously for 5m according to Table 1. 5.3.3 Layer seam test
Overlap and sew the sewing materials as shown in Figure 4, and sew twice as specified in Table 1. 2 layers
5.3.4 Seam thickness
Overlap the sewing materials into 6 layers, and sew twice as specified in Table 1. 5.3.5 Sewing material layer creep
The test method shall be in accordance with Article 6.3.6 of ZBY17020. 5.3.6 High and low speed sewing
The test method shall be in accordance with Article 6.3.4 of ZBY17020. 5.4 Running performance test
5.4.1 Running noise
a. No abnormal noise
Adjust the stitch length to 3.6mm, lift the presser foot, run at 3500 stitches/min without load, and judge by ear; 250
Noise level
Perform according to QB/T1177.
5.4.2 Vibration displacement
Perform according to QB/T1178 (see Figure 5)
5.4.3 Starting torque
Perform according to ZBY17023.
5.4.4 Lubrication and sealing
Daily oil window to check oil supply
QB/T 1574-1992
Sensor mounting seat
Sealing: After the sewing test, check each joint daily, no oil: After the continuous sewing project test, check that the sewing material should be free of oil stains. 5.5 Accessories and spare parts
According to the instructions for use or the packing list, check each item by counting, and do not exceed the number specified by hand. 6 Inspection rules
6.1 Each machine head leaving the factory must be inspected and qualified by the quality inspection department of the manufacturer and accompanied by an inspection certificate before it can leave the factory. A seam sample of the continuous stitch of the machine head should be attached under the presser foot, and the seam sample size is 1×b, 100mm×30mm. 6.2 The consignee has the right to accept the goods according to the factory inspection items specified in this standard. If there are other requirements, the supply and demand parties shall negotiate and decide. 6.3 Inspection classification
Inspection items, unqualified categories, and inspection classifications shall be as specified in Table 2. Unit products are counted as each machine head, A and B categories are counted as unqualified products, and C category is counted as the number of unqualified products.
Appearance quality
Machine performance
Sewing performance
Inspection items
4,1.1,4.1.2.4.1.3,4.1.4,4.1.54.2.1,4, 2.2+4.2. 3
4.2,4,4.2.5
4. 3.2.4.3. 3,4, 3. 4
4.3.5,4.3.6
Unqualified categories
Inspection categories
Running performance
6.3.1 Factory inspection
QB/T 1574-
Continued Table 2
4. 4. 1a,4. 4. 4
4.4. 1b,4.4.3
6.3.1.1 The sampling plan and strictness of factory inspection shall be in accordance with the provisions of GB/T2828, see Table 3. Table 3
Inspection level
Sampling plan
Unqualified category
Unit sample inspection items
Qualified quality level AQL
26~150
151~1200
1201~3200
Sample code
Sample size
Unqualified category
Normal inspection One sampling
Inspection classification
6.3.1.2 When the factory inspection fails, the manufacturer shall conduct a full inspection on the batch of products, remove or repair the unqualified products, and attach a rework record. The products can still be submitted for factory inspection again, but a stricter inspection must be used. If the products still fail to meet the standards after resubmission, the batch of products shall not be submitted for acceptance again.
6.3.2 Type inspection
Type inspection is generally carried out in one of the following situations. 6. 3. 2. 1
Every six months during normal continuous production;
There are major changes in design, structure, materials and process; b.
Stop production for more than one cycle and then resume production 6.3.2.2 Samples for type inspection shall be randomly selected from the products that have passed the factory inspection in this quarter. 6.3.2.3 Before type inspection, all samples to be inspected shall be inspected according to the factory inspection items. If unqualified products are found, they shall be replaced with qualified products, and the reasons shall be analyzed and included in the type inspection report, but shall not be used as the basis for qualified type inspection. 6.3.2.4 The sampling plan for type inspection and the judgment of qualified or not shall be in accordance with the provisions of GB/T2829, see Table 4. Table 4
Discrimination level
Sampling plan
Unqualified classification
Unit sample inspection items
Second sampling
Discrimination level
Unqualified quality level RQI
Sample size
QB/T1574-1992
Continued
: The treatment after type inspection shall comply with Article 4.12 of GB/T2829. Marking, packaging, transportation, storage
7.1 Marking
7.1.1 Product marking
The following markings shall be on the head:
Product name:
Product model;
Trademark;
Manufacturer's name
Manufacture date and number.
7.1.2 Outer packaging marking
According to the provisions of ZBY17004.
7.2 Packaging, transportation and storage
According to the provisions of ZBY17004.
Additional remarks:
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 is drafted by Shanghai Industrial Sewing Machine Factory. The main drafters of this standard are Yao Minjia and Lin Pingru. 15 Accessories and spare parts
According to the instructions for use or the packing list, check each item by counting, and do not exceed the number specified by hand. 6 Inspection rules
6.1 Each machine head leaving the factory must be inspected and qualified by the quality inspection department of the manufacturer and accompanied by an inspection certificate before it can leave the factory. A seam sample of the continuous stitch of the machine head should be attached under the presser foot. The seam sample size is 1×b, 100mm×30mm. 6.2 The consignee has the right to accept the goods according to the factory inspection items specified in this standard. If there are other requirements, the supply and demand parties shall negotiate and decide. 6.3 Inspection classification
Inspection items, unqualified categories, and inspection classifications shall be as specified in Table 2. Unit products are counted as each machine head, A and B categories are counted as unqualified products, and C category is counted as the number of unqualified products.
Appearance quality
Machine performance
Sewing performance
Inspection items
4,1.1,4.1.2.4.1.3,4.1.4,4.1.54.2.1,4, 2.2+4.2. 3
4.2,4,4.2.5
4. 3.2.4.3. 3,4, 3. 4
4.3.5,4.3.6
Unqualified categories
Inspection categories
Running performance
6.3.1 Factory inspection
QB/T 1574-
Continued Table 2
4. 4. 1a,4. 4. 4
4.4. 1b,4.4.3
6.3.1.1 The sampling plan and strictness of factory inspection shall be in accordance with the provisions of GB/T2828, see Table 3. Table 3
Inspection level
Sampling plan
Unqualified category
Unit sample inspection items
Qualified quality level AQL
26~150
151~1200
1201~3200
Sample code
Sample size
Unqualified category
Normal inspection One sampling
Inspection classification
6.3.1.2 When the factory inspection fails, the manufacturer shall conduct a full inspection on the batch of products, remove or repair the unqualified products, and attach a rework record. The products can still be submitted for factory inspection again, but a stricter inspection must be used. If the products still fail to meet the standards after resubmission, the batch of products shall not be submitted for acceptance again.
6.3.2 Type inspection
Type inspection is generally carried out in one of the following situations. 6. 3. 2. 1
Every six months during normal continuous production;
There are major changes in design, structure, materials and process; b.
Stop production for more than one cycle and then resume production 6.3.2.2 Samples for type inspection shall be randomly selected from the products that have passed the factory inspection in this quarter. 6.3.2.3 Before type inspection, all samples to be inspected shall be inspected according to the factory inspection items. If unqualified products are found, they shall be replaced with qualified products, and the reasons shall be analyzed and included in the type inspection report, but shall not be used as the basis for qualified type inspection. 6.3.2.4 The sampling plan for type inspection and the judgment of qualified or not shall be in accordance with the provisions of GB/T2829, see Table 4. Table 4
Discrimination level
Sampling plan
Unqualified classification
Unit sample inspection items
Second sampling
Discrimination level
Unqualified quality level RQI
Sample size
QB/T1574-1992
Continued
: The treatment after type inspection shall comply with Article 4.12 of GB/T2829. Marking, packaging, transportation, storage
7.1 Marking
7.1.1 Product marking
The following markings shall be on the head:
Product name:
Product model;
Trademark;
Manufacturer's name
Manufacture date and number.
7.1.2 Outer packaging marking
According to the provisions of ZBY17004.
7.2 Packaging, transportation and storage
According to the provisions of ZBY17004.
Additional remarks:
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 is drafted by Shanghai Industrial Sewing Machine Factory. The main drafters of this standard are Yao Minjia and Lin Pingru. 15 Accessories and spare parts
According to the instructions for use or the packing list, check each item by counting, and do not exceed the number specified by hand. 6 Inspection rules
6.1 Each machine head leaving the factory must be inspected and qualified by the quality inspection department of the manufacturer and accompanied by an inspection certificate before it can leave the factory. A seam sample of the continuous stitch of the machine head should be attached under the presser foot. The seam sample size is 1×b, 100mm×30mm. 6.2 The consignee has the right to accept the goods according to the factory inspection items specified in this standard. If there are other requirements, the supply and demand parties shall negotiate and decide. 6.3 Inspection classification
Inspection items, unqualified categories, and inspection classifications shall be as specified in Table 2. Unit products are counted as each machine head, A and B categories are counted as unqualified products, and C category is counted as the number of unqualified products.
Appearance quality
Machine performance
Sewing performance
Inspection items
4,1.1,4.1.2.4.1.3,4.1.4,4.1.54.2.1,4, 2.2+4.2. 3
4.2,4,4.2.5
4. 3.2.4.3. 3,4, 3. 4
4.3.5,4.3.6
Unqualified categories
Inspection categories
Running performance
6.3.1 Factory inspection
QB/T 1574-
Continued Table 2
4. 4. 1a,4. 4. 4bzxz.net
4.4. 1b,4.4.3
6.3.1.1 The sampling plan and strictness of factory inspection shall be in accordance with the provisions of GB/T2828, see Table 3. Table 3
Inspection level
Sampling plan
Unqualified category
Unit sample inspection items
Qualified quality level AQL
26~150
151~1200
1201~3200
Sample code
Sample size
Unqualified category
Normal inspection One sampling
Inspection classification
6.3.1.2 When the factory inspection fails, the manufacturer shall conduct a full inspection on the batch of products, remove or repair the unqualified products, and attach a rework record. The products can still be submitted for factory inspection again, but a stricter inspection must be used. If the products still fail to meet the standards after resubmission, the batch of products shall not be submitted for acceptance again.
6.3.2 Type inspection
Type inspection is generally carried out in one of the following situations. 6. 3. 2. 1
Every six months during normal continuous production;
There are major changes in design, structure, materials and process; b.
Stop production for more than one cycle and then resume production 6.3.2.2 Samples for type inspection shall be randomly selected from the products that have passed the factory inspection in this quarter. 6.3.2.3 Before type inspection, all samples to be inspected shall be inspected according to the factory inspection items. If unqualified products are found, they shall be replaced with qualified products, and the reasons shall be analyzed and included in the type inspection report, but shall not be used as the basis for qualified type inspection. 6.3.2.4 The sampling plan for type inspection and the judgment of qualified or not shall be in accordance with the provisions of GB/T2829, see Table 4. Table 4
Discrimination level
Sampling plan
Unqualified classification
Unit sample inspection items
Second sampling
Discrimination level
Unqualified quality level RQI
Sample size
QB/T1574-1992
Continued
: The treatment after type inspection shall comply with Article 4.12 of GB/T2829. Marking, packaging, transportation, storage
7.1 Marking
7.1.1 Product marking
The following markings shall be on the head:
Product name:
Product model;
Trademark;
Manufacturer's name
Manufacture date and number.
7.1.2 Outer packaging marking
According to the provisions of ZBY17004.
7.2 Packaging, transportation and storage
According to the provisions of ZBY17004.
Additional remarks:
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 is drafted by Shanghai Industrial Sewing Machine Factory. The main drafters of this standard are Yao Minjia and Lin Pingru. 1
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