This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of bicycle front forks (hereinafter referred to as "front forks"). This standard applies to front forks for general use as specified in QB1714 "Bicycle Naming and Model Compilation Method". QB 1881-1993 Bicycle Front Forks QB1881-1993 Standard download decompression password: www.bzxz.net

Industry Standard of the People's Republic of China
Bicycle Industry Standard
1994-01-16 Issued
Implementation of 1994-080
Issued by the Ministry of Light Industry of the People's Republic of China
Subject Content and Applicable Scope
Industry Standard of the People's Republic of China
Bicycle Front Fork
QB 1BB1- 93
This standard specifies the product technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of bicycle front forks [hereinafter referred to as \previously\).
This standard applies to the front forks of general vehicles specified in QB1714t Vehicle Naming and Model Compilation Method. 2 Reference standards
GB2828 Batch inspection counting sampling procedures and sampling tables (applicable to continuous batch inspection) GB2829 Periodic inspection counting sampling procedures
and sampling tables (applicable to production process stability inspection)
GB3565
Motor vehicle safety requirements
GB1 2742 Bicycle testing equipment and technical conditions QB1880 Bicycle frame QB11217 Bicycle electroplating technical conditions QB/TI218 Bicycle accessories QB1221 Bicycle metric thread gauges QB1221 Bicycle thread patterns and gauges 3 Product categories 3.1 Product names See 1.
1—front 2 stand 2—front 3—-double generation—
5—left and right front and period 6—fat Zhang| ... 188193
: Table 1
Business type and
Education type front area
Sports type more
Mi or medium 6.3
Technical support Beijing
Huang Yi and block
Back medical level
3.4 ​​Standard transportation example
(2B1881—93
x:2+V]
bi. nn5-24—5g
Wheel diameter 7m front and riser high quality: 7mm sales type (F type) front: front × 1710 × 17218814 Technical requirements
4.1 Condition
4. 1.1 The effective dimensions and tolerances in Table 2 are the same as those in B1220 or Q1221. 4.1.2 The mounting bracket can be 22.1mm and must comply with the requirements of Figure 7 in 3.3. 4.1.3 Symmetry of the front sub-legs. The front and rear sub-legs are symmetrical to the center line of the front sub-legs. The tolerance is 2.cmmm. 4.1.4 Verticality of the front opening. The symmetrical center plane of the front fork at the opening should be vertical with a tolerance of 1.mm. 41.5 The bottom of the front fork opening should be vertical relative to the center plane of the front fork with a tolerance of 1.5mm. 4.2 Strength 4.3.1 The energy absorption of the front fork should be 50, and the position should be greater than 401. And the front fork parts should not have any surface pattern, breakage, etc. 4.2.2 The front fork should not vibrate or break. 5. 4.2 The front fork parts should not be deformed or moved. 4.2.3 The frame/front derailleur assembly should comply with the provisions of Chapter 7 of 6B3565. 4.2. 4.3 Paint 4.3.1 Paint appearance shall comply with the provisions of Q/T1318 Article 3.1, 1.3.2 Seats and other parts shall comply with the provisions of QK1318 Article 3.2: 4.3.3 Anti-corrosion performance QB1881-93 shall comply with QB/1218 Article 3.$ Class I and shall be specified. 4.3. 4.4 Chain
4.4.1 Chain appearance
shall comply with the provisions of QB/T 1218 Section 3.4. -: 4.4 Chain
4.4.1 Chain appearance
shall comply with the provisions of QB/T 1217 Section 5.1. The front fork is a Class I part, the front fork is a Class II part, and the front fork side is a Class II part: the others are Class III parts.
4.4.2 Surface roughness of chrome-plated parts
shall comply with the provisions of QB/T 1218 Section 5.2. The front fork is a Class I part; the front fork is a Class II part, and the front fork side is a Class II part.
4.4.3 Degree of roughness
shall comply with the provisions of QT/T 1217 Section 5.3. The front fork is a Class I part, and the others are Class II parts. 4.4 The anti-separation ability of the parts
shall comply with the provisions of QB/T1217 Section 5.4. 4.5 Other appearance requirements
4.5.! The surface shall not have obvious wrinkles, bruises, pressure marks, etc. 4.5.2 The markings shall be clear, uniform and neat, and shall not have obvious new lines, etc. defects. 4.5.3 The decals shall be straight and shall not have obvious defects such as defects, wrinkles, etc. 5 Test methods
The testing equipment and instruments specified in this chapter shall comply with the provisions of GB12742. 5.1 Accuracy test
5.1.1 Grain accuracy
The grain accuracy shall be measured with a butterfly gauge, and the gauge shall comply with the provisions of QB1220 or H1221. 5.1.2 Assembly dimensions
@22.1mm, @27mm with a free-running caliper or a special gauge. 5.1.3 Symmetry of front fork legs
5.1.3.1 Fix the front fork leg on the platform, so that the distance between the shoulder plane (bottom plane of the lower stopper) and the fork leg end is 10mm; use a straight line to calibrate the fork leg at a distance of 11mm from the tightening end to make it perpendicular to the platform. 5.1.3.2 As shown in Figure 3, install a special shaft at the front ten mouth, and use white to measure the two ends of the fork leg. The difference between the values ​​is 1319
(B1881-93| |tt|| is the tolerance value of symmetry (measure the · side first, then measure the other side). 5.1.4 Verticality of the front fork opening
5.1.4.1 The clamping method is the same as that in 5.1.3.1]. 5.1.4.2 As shown in Figure 4. Use a square ruler and a caliper to measure the half of the single fork opening. The sum of the upper and lower values ​​is the verticality of the opening
5.1.5 Verticality of the front fork opening| |tt||5.1.5.1 The installation is the same as 5.1.3.1, as shown in 5.15.2. Use a square ruler and an inner diameter dial indicator to measure the bottom of the upper and lower openings along the front fork opening. The difference between the upper and lower values ​​is the verticality tolerance value of the bottom of the opening. 5.2 Strength test
5.2. [Front fork absorption tube disc test
Canada 5 shows that after installing a special roller at the front opening, the front The fork is fixed on a special V-shaped pad, and the distance from the fork to the plane is 10mm. The pad is adjusted to make the wheel center line and the vertical center line close to each other. The test results are observed when the wheel is subjected to the four-force frequency of 65mm.
5.2.2 Front fork vibration test
According to the provisions of Article 5.4.2 of QB1880,
wbzsosocom5.2.3 Frame/front safety assembly will be tested again after the object falls. 35 Article 25.1.
5.2.4 Frame/front panel assembly drop test according to Article 25.2 of GB3565
5.3 Dynamic paint test
5.3.1 Appearance inspection of film
According to Article 4.1 of QB/T121.
5.3.2 Deep film penetration test
QB 1881-93
According to the provisions of QB/1215 Section 4.2. Impact position: In the middle of the full length of the fork outside the fork (if the fork impacts the curved part, it can be moved upward to the straight surface). 5.3.3 Film corrosion resistance test
According to the provisions of QB/T1218 Section 4.3. Immersion position: Under the front and aiming space, based on the upper end of the sequence, immersed in 5/3. 3.4 Continuity test
According to the provisions of QB/T121B Section 4.4. Test location: On the outside of the two legs of the front fork, 50mm from the upper end of the shoulder and start to scratch downward along the axial direction,
S.4 Electroplating test bottle
5.4.1 Electroplating appearance test
According to the provisions of QB/T1217 Section 5.1.2. Test location: The outer surface of the two legs and the outer surface of the fork. 5.4.2 Chain surface comparison test
QB/1217 Section 5.2.2, test location: the outer surface of the two forks and the outer surface of the room. $.4.3 The thickness of the environmental layer shall be tested according to the provisions of QB/T1217 Section 5.3.2. Test location: the outer surface of the two forks and the outer surface of the shoulder. 5.5.4 The ammonium corrosion resistance test of chrome-plated parts shall be tested according to the provisions of QB/1217 Section 5.4.2. The area of ​​the test piece is limited to the sum of the two surfaces of the test piece and the front fork resistance area. The formula for calculating the resistance area of ​​the front fork is: A-(L+L,E
In the formula, A—the area of ​​the front fork resistance; [—the circumference of the upper end of the fork resistance;
L—the circumference of the lower end of the front fork resistance;
L—the length of the front and rear fork resistance.
5.5 Other appearance tests
All tests are conducted by hand. bZxz.net
6 Inspection rules
6.1. The product must be inspected and qualified by the quality inspection department of the manufacturer, and the certificate of conformity must be attached. "Qualified products". 6.2 Unit product: piece, 6.3 Factory control and testing, Shenzhen AGB2628. 6.3.1 Sampling plan, secondary oil sample, element: 6.3.2 Report quality, calculated by unqualified products per 100 units of production, 6.3.3 Inspection items, QB188193, according to the direct water level (1L), those that do not meet the quality level (AQL> see Table 3
Geha project
Assembly size
Shanguan appearance
Liguqi surface roughness
Agriculture and development
Line requirements
6.4 Type initial inspection
Adopt 6B2829
6.4.1 Inspection cycle
One month
6.4.2 Sample shooting plan
Technical standard year of death
Technical result requirements
:.4. 3, 1
Say
4.2.3~4.2.1 is a one-time oil sample, and the other items are sampled once a month. 6.4.3 Batch quality
is calculated by the number of unqualified products per 100 units. 6.41.1 Inspection and supervision items
"Unqualified
Judgment level (D) Daily qualified classification, unqualified level Q1). Control cost size
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