This standard specifies the structure of latch needles for knitting machines and the names, models, technical requirements, test methods, inspection rules, packaging, marking, transportation and storage of each part. This standard applies to latch needles made of steel wire and T for knitting machines. QB/T 1517-1992 Latch needles for knitting machines QB/T1517-1992 Standard download decompression password: www.bzxz.net

Light Industry Standard of the People's Republic of China
Latch needles for knitting machines
Subject content and scope of application
QB/T 1517--1992
This standard specifies the structure of latch needles for knitting machines and the names of their various parts, models, technical requirements, test methods, inspection rules, packaging, marking, transportation and storage.
This standard applies to latch needles made of steel wire for use in knitting machines. 2 Reference standards
Packaging, storage and transportation pictorial marking
GB 191
Metal Rockwell hardness test method
GB/T 230
GB/T1957
GB/T1958
GB/T2828
GB/T 2829
GB/T 3206
GB/T 5952
GB/T 6543
ZBY 17027
3 Product classification
Smooth limit gauge
Shape and position tolerance inspection regulations
Counting sampling procedure and sampling table for batch inspection (applicable to inspection of continuous batches)Counting sampling procedure and sampling table for periodic inspection (applicable to inspection of production process stability)High-quality carbon structural steel wire
Carbon tool steel wire
Corrugated cardboard box
Household knitting machine
3.1Latch needle structure, classification and names of its partsThe latch needle structure, classification and names of its parts are shown in Figure 1. Needle
3.2 Model
The needle model consists of five parts, and the writing format is as follows: Approved by the Ministry of Light Industry of the People's Republic of China on June 8, 1992 a. Front curve
b. Back curve
Implemented on February 1, 1993
Latch needle curve
Needle hook shape characteristic code
Latch needle bar length
Latch needle bar thickness
Latch needle code for knitting machine
Needle bar thickness (mm), expressed in two Arabic numerals, when writing the model, take the integer part of 10 times the actual needle bar thickness. 3.2.1
3.2.2Latch needle bar length (mm), take the integer part and express it in three Arabic numerals. 3.2.3 Needle hook shape characteristic code, expressed in one capital Chinese phonetic letter, Y represents a round solitary needle hook. 3.2.4 The hook type of the latch needle is indicated by one capital Chinese phonetic letter, Q indicates the front hook type, and H indicates the back hook type. 3.3 Model marking example
The needle bar length is 80mm, the needle bar thickness is 1.2mm, and the hook shape is an arc-shaped front hook type. Its model marking is: BS12080YQ
4 Technical requirements
4.1 Performance
4.1.1 Dimensional accuracy of the latch needle
The external dimension symbol of the latch needle is shown in Figure 2. The dimensional accuracy of the latch needle is shown in Table 1. L
Figure 2 Dimensions of latch needles Symbols
Name and bar needle Needle bar needle
Bar thickness B
Tail width
Tail thickness
±0. 03±0. 10
±0.10±0.035±0.10
±0.10|±0.04
±0. 10±0.045
Latch needle dimension accuracy table
Needle tongue
Needle tongue
Lower height h
±0.10±0.10
Needle head tongue
4.1.2Except the hook part, the straightness error of the latch needle over its entire length shall not exceed 0.25mm. 4.1.3 Surface roughness R of latch needle. The maximum value should not be greater than 0.8um, and the needle hook part should not be greater than 0.4μm. 232
QB/T 1517—1992
4.1.4 The needle hook should be symmetrical to the center plane of the needle rod, and the needle tongue should fit snugly on the tip of the needle hook. The left and right swing of the needle tongue relative to the center plane of the needle hook should not exceed one-third of the needle head diameter. 4.1.5 The pin holes on both sides of the tongue seat should be located in the center of the tongue seat, and the tail of the needle tongue should not be exposed outside the needle tongue groove. 4.1.6 The surface of the needle tongue head should be smooth, without a sharp tip or a sharp edge. 4.1.7 The needle tongue should be able to swing back and forth flexibly in the tongue needle groove without sluggishness. 4.1.8 The tongue needle should be placed horizontally with the needle tongue facing downward. When the needle tongue is hung with a thin steel wire according to the requirements of Table 2, the needle tongue shall not fall off from the tongue needle groove. Table 2 Needle tongue bonding strength
Thickness of needle bar, mm
Static tensile force applied, N
4.2 Physical properties
4.2.1 After heat treatment, the hardness of the tongue needle should be HRC50~～58.1.0
4.2.2 Bending strength of tongue needle: Apply force to the pin hole of the tongue needle seat according to the requirements of Table 3, so that the force line is perpendicular to the plane of the tongue seat. When the external force is removed, the needle bar of the tongue needle should be able to return to its original state.
Table 3 Bending strength test table of tongue needle
Thickness of needle bar, mm
Distance between the force application point and the tongue needle fulcrum, mm
Bending angle of tongue needle under force, (°)
Force time of tongue needle, s
4.3 Appearance
The outer surface of the tongue needle should be flat and smooth, without burrs, knots, or edges. The outer surface of the electroplated latch needle shall be free of rust, pitting, cracks, blistering, shedding and other defects.
4.4 Materials
Latch needles shall be made of carbon tool steel wire, of which the material of the needle tongue shall not be lower than T9A, and the rest of the parts shall be made of carbon steel wire not lower than 60# steel.
5 Test methods
5.1 Test conditions
Unless otherwise specified, all tests shall be carried out in the following environment and conditions: ambient temperature: 8~35℃,
relative humidity: 45%~75%;
atmospheric pressure: 86~106kPa,
illuminance: 100~250lx;
visual inspection vision: ≥1.3.
5.2 Performance inspection
5.2.1 Latch needle dimensional accuracy inspection
Use a vernier caliper to check. When the measured dimensional accuracy is less than 0.1mm, use a measuring tool with a graduation value of 0.01mm; when the measured dimensional accuracy is not less than 0.1mm, use a measuring tool with a graduation value of 0.02mm. The inspection results should comply with the provisions of Table 1 of Article 4.1.1 of this standard.
5.2.2 Latch needle straightness inspection
Use the direct method to inspect according to the No. 1 inspection principle in GB/T1958. The inspection results should comply with the provisions of Article 4.1.2 of this standard. 5.2.3 Surface roughness inspection
QB/T 1517.. 1992
Use a 5-10 times magnifying glass to visually inspect the latch needle and the standard latch needle sample at a visual distance of 25cm and a 45° oblique or straight viewing angle for comparative inspection. In case of disputes, a surface roughness profiler or light-section microscope shall be used for arbitration, and the inspection results shall comply with the provisions of Article 4.1.3 of this standard.
5.2.4 Inspection of Article 4.1.4 of this standard
5.2.4.1 The inspection of the symmetry of the needle hook relative to the center plane of the needle bar shall be inspected by a special slot width inspection fixture. The inspection of the measured elements shall comply with the principle of maximum substance, and the gauge accuracy shall comply with the IT7 grade requirements in Table 1 of GB/T1957. The working dimensions of the inspection fixture are shown in Figure 3. The meanings of the letters in Figure 3 are the same as those in Figure 2. h
广植深
5.2.4.2 The inspection of the quality of the fit between the needle tongue and the hook tip shall be carried out by visual inspection, and the observation results shall comply with the corresponding provisions of Article 4.1.4. 5.2.4.3 Inspection of the left-right swing of the needle tongue relative to the center plane of the needle hook Place the latch needle horizontally with the needle facing upwards and inspect according to the No. 2 inspection principle of GB/T1958. The results shall comply with the corresponding provisions of Article 4.1.4. 5.2.5 Inspection of Article 4.1.5 of this standard
shall be conducted by visual inspection, and the observation results shall comply with the provisions of Article 4.1.5. 5.2.6 Inspection of Article 4.1.6 of this standard
shall be conducted by visual inspection, and the observation results shall comply with the provisions of Article 4.1.6. 5.2.7 Inspection of Article 4.1.7 of this standard
Make the latch needle stand upright, with the needle hook on top, and the needle tongue in the tongue-down state, and then use a steel ruler to support the back of the needle tongue. Release the hand holding the needle. If the latch needle can fall off the steel ruler under its own weight, and the needle tongue is supported by the steel ruler to the tongue-up state, it can be judged to comply with the provisions of Article 4.1.7. 5.2.8 The test in 4.1.8 of this standard shall be carried out in accordance with and in accordance with the provisions of 4.1.8 of this standard. 5.3 Physical property test 5.3.1 Latch needle hardness test The latch needle hardness shall be tested with a Rockwell hardness tester. The test method shall comply with the provisions of GB/T230. The arithmetic mean of the measured results at the three measuring points of the latch needle shaft, needle and needle tail shall be taken as the test result. The test result shall comply with 4.2 of this standard.1. 5.3.2 The bending strength test of the latch needle
shall comply with the provisions of Article 4.2.2 of this standard. 5.4 The appearance inspection of the latch needle
shall be carried out by visual inspection, and the observation results shall comply with the provisions of Article 4.3 of this standard. 5.5 The material inspection of the latch needle
shall comply with the provisions of GB/T3206GB/T5952. 6 Inspection rules
6.1 The inspection of the latch needle is divided into factory inspection and type inspection. 6.2 The latch needles provided by the manufacturer to the user must pass the factory inspection and be equipped with a certificate of conformity. 6.3 The latch needles provided for inspection shall be composed of 10,000 pieces in an inspection batch, and the latch needles in the same inspection batch shall be products under the same production conditions. Samples shall be randomly selected from the same inspection batch.
., 6.4 The type inspection shall be carried out once a month or designated by the national quality supervision department. 234
QB/T 1517—1992
6.5 The items of type inspection are the entire contents of the technical requirements of this standard. 6.6 The items of factory inspection are Articles 4.1.1 to 4.1.8, 4.2.2, and 4.3 of the technical requirements of this standard. 6.7 The sampling of inspection shall be carried out in accordance with the provisions of GB/T2828 and GB/T2829, and the quality of the inspected batch shall be expressed as the number of unqualified products per 100 units of products.
6.7.1 Inspection level and discrimination level
For factory inspection: general inspection level II;
For type inspection: discrimination level I.
6.7.2Qualified quality level: AQL-6.5; unqualified quality level: RQL-25. 6.7.3 Sample size of sampling inspection
For factory inspection: 200;
For type inspection: 20.
6.7.4 Sampling plan for inspection
One sampling for normal inspection, one sampling for discrimination level 16.7.5 The qualified judgment number (A.) and the unqualified judgment number (R.) of sampling inspection Factory inspection: A. =21; R=22.
Type inspection: A3; R=4.
6.8 The disposal of the tongue needle after sampling inspection shall comply with the provisions of GB/T2828 and Article 4.12 of GB/T2829. 7 Marking, packaging, transportation, purchase and storage
7.1 The inner packaging of the tongue needle shall be subject to the user's requirements in terms of quantity. 7.2 The tongue needle shall be cleaned before packaging, then coated with anti-rust oil, wrapped with moisture-proof paper as inner packaging, and attached with product certificate. 7.3 The transportation packaging of the tongue needle is a double corrugated box. The structure of the corrugated box and the selection of corrugated board shall comply with the provisions of GB/T6543. The following signs should be printed on the transport package of the latch needle: 7.4
Product name;
Product specification model;
Inner package quantity;
Transport package quantity;
Outer package size,
Upward, moisture-proof, pressure-proof illustration;
Manufacturer's name.
7.5The bottom of the transport package corrugated box should be lined with double corrugated cardboard before packing, and the top should also be lined with double corrugated cardboard after packing. The cardboard is selected in the same way as the corrugated box.
7.6The transport package should be sealed with packaging tape and tied with plastic strapping tape, with the number of straps not less than 3. 7.7Latch needles should be transported under a canopy, and should be protected from moisture, extrusion and collision during transportation or loading and unloading, and should be avoided from being transported in the same vehicle with corrosive items such as acids and alkalis.
7.8 The storage conditions of latch needles in the warehouse are: ambient temperature: -20~～+40℃; bzxZ.net
Relative humidity: not more than 75%;
Good ventilation, the air does not contain corrosive and harmful gases. 235
Additional remarks:
QB/T1517—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 Industry Standardization Center. This standard was drafted by Yiyang Sewing Machine Factory, Nanjing Sewing Machine General Factory, Shandong Muping No. 1 Needle Factory, Wuhan Knitting Equipment Factory, Shanghai Global Knitting Machinery Factory, Zhejiang Jiande County Needle Factory, and Wuhan Daily Machinery Manufacturing Company. The main drafters of this standard are He Jianxian, Gao Yang, Jiang Yizheng, Dai Ningbin, Xu Zuoyun, Liu Xiaobao, Li Jusheng, and Jiang Aizhu. This standard adopts the Japanese Industrial Standard JISB9092 "Knitting Needles for Household Knitting Machines". 236
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