Standards related to:

GB/T 39015.2-2020GB/T 39015.2-2020

GB

NATIONAL STANDARD OF THE

PEOPLE’S REPUBLIC OF CHINA

ICS 43.080.10

T 72

Road vehicles - Interchangeability of mechanical

couplings between tractors and semi-trailers - Part 2:

Low-coupling tractors and high-volume semi-trailers

(ISO 1726-2:2007, Road vehicles - Mechanical couplings between tractors

and semi-trailers - Part 2: Interchangeability between low-coupling tractors

and high-volume semi-trailers, MOD)

ISSUED ON: JULY 21, 2020

IMPLEMENTED ON: FEBRUARY 01, 2021

Issued by: State Administration for Market Regulation;

Standardization Administration of the People's Republic of

China.

Table of Contents

Foreword ... 3

1 Scope ... 5

2 Interchangeability size ... 5

3 Control size ... 9

4 Marks ... 11

Foreword

GB/T 39015 “Road vehicles - Interchangeability of mechanical couplings

between tractors and semi-trailers” consists of two parts:

- Part 1: Semi-trailer tractors and semi-trailers for general cargo

transportation;

- Part 2: Low-coupling tractors and high-volume semi-trailers.

This Part is Part 2 of GB/T 39015.

This Part was drafted in accordance with the rules given in GB/T 1.1-2009.

This Part uses redrafting method to modify and adopt ISO 1726-2:2007 “Road

vehicles - Mechanical couplings between tractors and semi-trailers - Part 2:

Interchangeability between low-coupling tractors and high-volume semi-

trailers”.

The technical differences and reasons between this Part and ISO 1726-2:2007

are as follows:

- modified Clause 1 as “This Part of GB/T 39015 specifies interchangeability

size, control size and marks of interchangeability of mechanical couplings

between tractors and semi-trailers. This Part is applicable to two-axle

semi-trailer tractors and matching semi-trailers.”; added marking

requirements to the scope based on the actual content of this Part; at the

same time, deleted the description of the maximum allowable total mass

and outline size that has nothing to do with the content;

- modified "L3=1800mm" in 2.4.2 to "L3≤1800mm" to meet the requirements

of the trailer size limit in the relevant national standards of China.

This Part made the following editorial modifications:

- modified the standard name to “Road vehicles - Interchangeability of

mechanical couplings between tractors and semi-trailers - Part 2: Low-

coupling tractors and high-volume semi-trailers”;

- added notes to r2 and r3 in Figure 3b);

- deleted Bibliography in ISO 1726-2:2007.

This Part was proposed by Ministry of Industry and Information Technology of

the People's Republic of China.

Road vehicles - Interchangeability of mechanical

couplings between tractors and semi-trailers - Part 2:

Low-coupling tractors and high-volume semi-trailers

1 Scope

This Part of GB/T 39015 specifies interchangeability size, control size and

marks of interchangeability of mechanical couplings between tractors and semi-

trailers.

This Part is applicable to two-axle semi-trailer tractors and matching semi-

trailers.

2 Interchangeability size

2.1 Ground clearance of coupling of tractor under maximum load

Under the maximum load condition, the height h of the joint surface of the

coupling of tractor (see Figure 1) shall be 900mm~975mm.

Figure 1 -- Ground clearance of coupling of tractor

2.2 Ground clearance of coupling of tractor when disengaged from semi-

trailer

part of the gooseneck of the semi-trailer [see 2.4.1d)];

w1 - Forward angle;

w2 - Backward angle;

φ - Articulation angle.

Figure 2 -- Free space between tractor and semi-trailer

2.4 Gooseneck shape

2.4.1 The gooseneck shape shall be located on the outer area of the surface

composed of multiple different planes and a rotating surface connecting the two

planes. There shall be a smooth transition between the surfaces, as shown in

Figure 3. The planes and rotating surfaces are determined as follows:

a) The first plane AB is perpendicular to the horizontal plane of the traction

pin axis. The length is L1. The width is the same as the width of semi-trailer,

and ends at the intersection with the second plane as described in b);

b) For the second plane BC, the width is same with the width of semi-trailer.

The angle with the first plane is γ1. It ends with the line of intersection with

the third plane as described in c);

c) For the third plane CD, the width is same with the width of semi-trailer. The

angle with the first plane is γ2. It ends to the line of intersection with the

rotating surface as described in d);

d) A vertical line segment EF and a segment of arc DE with a radius of r2

between the third plane and the vertical line segment, form a rotation

curve. The rotation curve takes r3 as radius to rotate around the traction

pin axis to form a rotating surface. Each surface shall be continuous;

e) The fourth plane AU is a horizontal plane at the front end of the semi-trailer

and perpendicular to the traction pin of the semi-trailer. The length is L3.

The width is same with the width of semi-trailer. It ends to the intersection

of the inclined plane UV with an angle α of the horizontal plane. The

foremost point V shall not exceed the vertical plane rotated with a radius

of 2040mm as the center of the traction pin axis.

2.4.2 The shape of the gooseneck is determined by the following parameters:

- The horizontal length of the first plane, L1=500mm;

- The sum of the horizontal length of the first plane and the second plane,

L2=1350mm;

- The horizontal length of the fourth plane, L3≤1800mm;

- The arc radius between the third plane and the vertical line of the

keys:

L1 - The horizontal length of the first plane (AB);

L2 - The sum of the horizontal lengths of the first plane and the second plane (AB and BC);

L3 - The horizontal length of the fourth plane (AU);

r1 - Front turning radius of semi-trailer;

r2 - Arc radius (DE);

r3 - The radius of rotation (EF) formed by the distance between the axis of the traction pin

and the vertical line of the gooseneck;

α - The angle between the horizontal plane and the inclined plane;

γ1 - The angle between the second plane (BC) and the first plane (AB);

γ2 - The angle between the third plane (CD) and the first plane (AB).

Figure 3 (continued)

3 Control size

3.1 Longitudinal inclination angle of semi-trailer relative to tractor

When a semi-trailer train is running straight, when the front and rear inclination

angles of semi-trailer relative to tractor (see Figure 2) meet the following

requirements, it shall not contact with the tractor (except hinged parts):

- Forward angle w1≤3.5°;

- Backward angle w2≤4.5°.

3.2 Lateral inclination angle

When the lateral inclination angle δ of semi-trailer relative to tractor (see Figure

4) changes within ±2°, there shall be no interference between tractor and semi-

trailer.

...