QC/T 633-2022Bus seats (English PDF)

3.7 Angle of seat cushion

On the center plane of the seat, the angle -- between the centerline of the thigh and the horizontal line.

3.8 Height of backrest

On the center plane of the seat, along a line parallel to the torso line passing through point G, the distance -- from the top of the backrest to point G.

3.9 Width of backrest

When the seat cushion is not depressed, the width -- between the two outer sides of the backrest, at 250 mm above the horizontal plane, which is tangent to the uppermost surface of the seat cushion, on the longitudinal center plane of the seat.

3.10 Height of armrest

The vertical height -- from the highest point on the upper surface of the handrail to point R'.

3.11 Width of armrest

The minimum width of the armrest's support surface.

3.12 Angle between backrest and cushion

In the center plane of the seat, the angle -- between the torso line and the center line of the thigh.

3.13 Adjustable range of backrest angle

a) For seats with detachable headrests, the unlocking force of the headrest shall not be greater than 20 N; the operating force shall not be greater than 100 N.

b) For the seat backrest angle adjustment device, the unlocking torque of the handle-type adjusting mechanism shall not exceed 6 N · m; the unlocking torque of the knob-type adjusting mechanism shall not exceed 4 N · m; the unlocking force of the button-type adjusting mechanism shall not exceed 60 N. When adjusting the backrest angle, the adjustment torque of the backrest shall not exceed 80 N · m.

c) The locking force of the lateral adjustment mechanism of the seat assembly shall not be less than 2000 N; the unlocking force of the handle of the lateral adjustment mechanism shall not be greater than 80 N; the operating force shall not be greater than 200 N.

4.5 Seat back frame requirements

4.5.1 Carry out the gap test of the seat back frame assembly, according to the method specified in 5.6; the gap of the seat back frame assembly shall meet the requirements in Table 3.

4.5.2 Carry out the stiffness test of the seat back frame assembly, according to the method specified in 5.7; its plastic deformation after unloading shall not exceed 10 mm.

4.5.3 After the durability test of the seat back frame assembly is carried out, according to the method specified in 5.8, there shall be no cracks in the back frame assembly.

4.6 Armrest requirements

4.6.1 The rotational moment of the armrest, on the active side of the seat, shall not exceed 25 N · m.

4.6.2 Carry out the static strength test of the side armrest of the seat, according to the method specified in 5.9. The armrest shall not be broken, damaged or fall off from the seat, etc. After the load is removed, its permanent deformation shall not exceed 10 mm.

4.6.3 After the cycle test of the side armrest of the seat is carried out, according to the method specified in 5.10, the armrest shall maintain its normal use function, without breaking, peeling off of the surface covering material, or exposure of the bottom, etc.

4.7 Footrest requirements

4.7.1 Carry out the static strength test of the seat footrests, according to the method specified in 5.11. The footrests shall not be broken, damaged or fall off from the seat.

4.7.2 After the cycle test of the seat footrests is carried out, according to the method specified in 5.12, the footrests shall maintain their normal function, without breaking, damage or falling off from the seat.

5.1 Strength test of the seat and its vehicle fixings

The strength test of the seat and its vehicle fixings shall be carried out, in accordance with the test methods specified in GB 13057.

5.2 Position and strength test of seat belt fixation point

The position and strength test of the fixed point of seat belt installation shall be carried out, in accordance with the test method specified in GB 14167.

5.3 Performance test of seat adjustment device

Apply a uniform load of 667 N on the seat cushion. Use a dynamometer, to measure the opening force of the lateral adjustment handle of the seat assembly, the operating force of the lateral adjustment, the unlocking force (moment) of the backrest adjustment device;

5.9 Static strength test of seat side armrest

Adjust the side armrest of the seat to the design position. At a distance of 50 mm from the front edge of the seat armrest, apply the following load at the same time, for a duration of 5 s:

a) Vertical downward load: 800 N;

b) Lateral horizontal load: 200 N.

After removing the load, measure the vertical deformation of the armrest, at the loading point.

5.10 Cycle test of seat side armrest

Fix the seat side armrest assembly on the test bench. Take the closed position of the seat armrest as the starting position of the cycle test. Open the armrest, from the closed position to the working position; then close it from the working position to the closed position, which is taken as the 1 cycle. 30000 cycles shall be completed, at a frequency of (10 ~ 30) cycles/min.

5.11 Static strength test of seat footrests

Install the seat footrest assembly on the test bench. Apply a load of 1200 N, on the footrest surface, which is perpendicular to the seat footrest for 5 s. After removing the load, observe the footrest assembly for use and damage. For adjustable footrests, the highest use position shall be selected for testing.

5.12 Cycle test of seat footrest

Fix the seat footrest assembly on the test bench. Take the initial position of the footrest, as the initial position of the cycle test. Move the footrest from the initial position to the end position, then back to the initial position, which is taken as one cycle. 10000 cycles shall be completed, at a frequency of (10 ~ 30) cycles/min.

6.1 Exit-factory inspection

6.1.1 The seat shall pass the inspection by the quality inspection department of the manufacturer AND be issued with the product certificate, before leaving the factory.

6.1.2 See Table 5, for the exit-factory inspection items.

6.2 Type inspection

6.2.1 In the following cases, the type inspection shall be carried out on the product:

a) Type identification of new products put into production or old products after trans-plant production;

b) After the official production, the structure, material and process have changed greatly, which may affect the performance of the product;

c) Normal production for 2 years or as agreed upon by both parties;

d) When production resumes after the product has been discontinued for one year;

e) When the quality supervision agency requests type inspection.

6.2.2 See Table 5 for type inspection items.

7.1 Marking

Each set of seats shall have a label when leaving the factory, which shall comply with the relevant provisions of GB/T 13306. For the adjustable parts of the seat, eye-catching operation instructions shall be marked in obvious positions.

7.2 Packaging

Seat cushions and backrests of seats must have protective packaging. The moving parts shall be coated with protective grease as required.

7.3 Transportation

Seats shall be loaded and unloaded gently, during transportation, to avoid damage from bumps and protect from exposure to sun and rain.

7.4 Storage

Seats shall be stored in dry, ventilated, fireproof warehouse, where there is no corrosive gas. It shall not be under heavy pressure, to avoid deformation.