GB/T 37245-2018General technical requirements for centre-axle trailer (English PDF)

3.1 Center-axle Trailer

Center-axle trailer refers to a kind of trailer, whose traction device cannot vertically move (relative to trailer) and whose axle is close to the center of gravity (when evenly loaded). In terms of this kind of trailer, only a little vertical static load is acting on the tractor, and not more than 10% of the maximum total mass of trailer or 10,000 N of load (the smaller one shall prevail). One axle or multiple axles can be driven by the tractor. [GB/T 3730.1-2001, definition 2.2.3]

3.2 Center-axle Trailer Combination

Center-axle trailer combination refers to the combination of truck and center-axle trailer.

3.3 Van Center-axle Trailer

Van center-axle trailer refers to center-axle trailer, which has an independent closed compartment structure, including fixed compartment and interchangeable compartment, and can endure the stipulated load.

4.1

4.1.8 After van center-axle trailer is connected with truck, when center-axle trailer's supporting device is withdrawn, the minimum ground clearance shall be not less than 320 mm.

4.1.9 The dimension parameters of connecting device of center-axle trailer (excluding caravan) and position parameter of adapted truck connector shall be marked in a conspicuous position of the front-end beam of the frame and clarified in technical documents.

4.1.10 Center-axle trailer for vehicle transportation shall comply with relevant requirements of finished trailers in GB/T 26774; center-axle caravan shall comply with relevant requirements of finished trailers in GB/T 36121.

4.1.11 Refrigeration and insulation performance of refrigerating van center-axle trailer shall comply with the stipulation in GB 29753. […]

4.2 Frame

4.2.1 When the total length of frame is not more than 8,000 mm, the dimensional deviation of its length shall be ± 5 mm. Every 1,000 mm of increase in length (when the increase is less than 1,000 mm, count by 1,000 mm), the dimensional deviation of length is allowed to increase 1 mm. The dimensional deviation of the measured width at random measurement point shall be ± 4 mm.

4.2.2 The longitudinal straightness tolerance of longitudinal web shall be 2 mm in random 1,000 mm of length; it shall be 1 per thousand length in the full length.

4.2.3 At random cross section of the longitudinal and horizontal beam, the perpendicularity tolerance of the upper and lower air foil against the web shall be not more than 1% of the width of the flange.

4.2.4 The symmetric upper plane of the left and right longitudinal beam of the frame assembly shall be within the same plane. The flatness tolerance shall be 1 per thousand of the length of the plane being measured.

4.2.5 The perpendicularity tolerance of the primary beam of the frame against the longitudinal web shall be not more than 3 per thousand of the length of the horizontal beam.

4.2.6 When the length of the frame is not more than 4,000 mm, the diagonal difference of the frame shall be not more than 6 mm. Every 1,000 mm of increase in length (when the increase is less than 1,000 mm, count by 1,000 mm), the diagonal difference of the frame is allowed to increase 1 mm.

4.2.7 Frames that transport interchangeable compartment shall be equipped with locking mechanism that complies with relevant requirements in GB/T 17382.

4.3 Compartment

4.4

4.4.8 Center-axle trailer shall be equipped with gas-electric connection device that complies with the requirement in GB/T 5053.1, GB/T 13881 and GB/T 20716.1.

4.4.9 The installation and pasting of reflective logo on the body of center-axle trailer shall comply with the stipulation in GB 23254 and GB 7258. The installation of identification plate on the tail of trailer shall comply with the stipulation in GB 25990 and GB 7258.

4.4.10 The side and rear-end guard device of center-axle trailer shall comply with the stipulation in GB 11567.

4.4.11 The setting of number plate (frame) shall comply with the stipulation in GB 15741 and GB 7258.

4.4.12 In a conspicuous position of the rear of center-axle trailer, 1 ~ 2 rectangular marking plates with the words "long vehicle" shall be installed. The length of the marking plates shall be 500 mm ± 10 mm; background color shall be yellow; the words shall be red. The colorimetric performance and photometric performance of the marking plates shall comply with the stipulation in GB 25990. The typeface of the words shall be normalized Chinese characters, which shall be put in an order from the left to the right, or from top to bottom. Character height shall be 180 mm ± 5 mm; character width and character height shall be equivalent.

4.4.13 Center-axle trailer shall be equipped with a spare tire, which shall be firmly fixated; conveniently assembled and disassembled.

4.4.14 Center-axle trailer shall be equipped with at least 2 parking wedges (for example, triangular sole timber). […]

4.5 Mechanical Connection Requirements

4.5.1 The longitudinal distance A (Figure 1) from the projection point of van center-axle trailer's traction loop center on a horizontal plane to the projection of truck's rearmost end on a horizontal plane shall comply with the stipulation in Table 1.

4.5.2 The up and down swinging angle alpha (Figure 1) of center-axle trailer's tow bar around the traction connector shall be not less than 6°. In addition, the minimum gap between the upper plane of the tow bar and the lower end of truck shall be not less than 125 mm (Figure 1).

4.5.3 Under the fully-loaded state, the vertical distance from center-axle trailer's traction loop center to the vehicle's supporting horizontal plane shall be 380 ± 25 mm (Figure 1). […]

4.6

4.6.3 Paint coating shall comply with the stipulation in QC/T 484 and product design.

4.6.4 All the adapting pieces and fasteners shall receive surface anti-rust treatment. Various joint parts shall be firm and reliable; satisfy the stipulated requirement of torque.

4.6.5 Oil cup and oil nozzle shall be fully assembled; filled with lubricating grease. Paint lubricating grease to other friction surfaces in accordance with the stipulation.

4.6.6 All the pipelines and circuits shall be reasonably distributed, firmly fixated and reliably clamped. During the vehicle operation process, friction interference phenomena are not allowed. Oil, gas and water pipelines shall not manifest any phenomena of leakage. […]

4.7 Performance Requirements

4.7.1 The braking performance of center-axle trailer and center-axle trailer combination shall comply with the stipulation in GB 7258 and GB 12676.

4.7.2 The lateral acceleration amplification factor of van center-axle trailer combination (test speed. 80 km/h) shall be not more than 2.0.

4.7.3 Under the empty-load and static state, center-axle trailer combination's left and right tilting stability angle shall be not less than 35°.

4.7.4 When center-axle trailer combination is in straight driving on a flat and dry ground at the speed of 30 km/h, the maximum offset of center-axle trailer's rear axle track centerline relative to tractor's front axle track centerline shall be not more than 110 mm.

4.7.5 The trafficability and external pendulum of center-axle trailer combination shall comply with the stipulation in GB 1589.