Technical Field

The invention relates to the assist system developed to allow the turning motion of trailers manufactured with respect to the load that they will carry within their turning circle.

In particular, the invention relates to the assist system which provides controlling of the load exerted on the differential of the motor vehicle towing the semi-trailer vehicle from kingpin connection by performing load transfer between axles by means of electronic pneumatic circuit components of the suspension system, and which provides a semi-trailer vehicle moving within turning circle regulation limits and conditions by standard axle construction.

Prior art

The trailer is a highway vehicle which is towed by a motor vehicle aimed at carrying cargo connected to the vehicle it is being towed by at least one axle designed and manufactured in relation to the cargo that it will carry, and a connection device that is defined as a tongue, rotary table, hook and similar names. Semi-trailer vehicles (A) are vehicles aimed at carrying cargo classified as 01 , 02, 03 and 04 as per highway regulation, with the regulation being subjected to technical arrangement number 1230/2012. In the context of the said Regulation 1230/2012 specifications which is the Type Approval Related to Mass and Dimensions of Motor Vehicles and their Trailers Regulation, the test should be run on a flat surface; during testing the vehicle should be loaded with respect to the maximum technically allowable mass and technically allowable maximum load on the axle; prior to start of testing tire air pressures should be as intended for the mass (indicated by the manufacturer while the vehicle is stationary); the described tests should result successfully under all load conditions. With Regulation 1230/2012 and in conformity with Highways Traffic Law provisions, in order to satisfy the obligation of conformity to highway structure and traffic safety in terms of manufacturing and utilization of vehicles, EU type approval conditions related to mass and dimensions of motor vehicles and trailers and procedures and principles belonging to their application have been determined.

The place where the motor vehicle and the semi-trailer is coupled (KP); and the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) of the 3-axle semi-trailer vehicle (A) used in prior art have been shown in Figure-1. If the said semi trailer vehicle (A) has one or more axle raising mechanism, the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer at lowered and raised position of the axle longer measurements of the axle center (WB) is taken as reference. When the semi-trailer vehicle (A) shown in Figure-2 having 3 axles and the raising of the 3rd axle (222) is active enters its turning circle, the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) is between the mid-point of the 1st axle (120) and the 2nd axle (221 ) and the place where the motor vehicle and the semi-trailer is coupled (KP). When the semi-trailer vehicle (A) shown in Figure-3 having 3 axles and the raising of the 3rd axle (222) is passive enters its turning circle, the distance from the place where the motor vehicle and the semi trailer is coupled to the semi-trailer axle center (WB) is between the place where the motor vehicle and the semi-trailer is coupled (KP) and the 2nd axle (221). If there exists a steering axle, this axle is not included in the measurement of the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB). When the semi-trailer vehicle (A) shown in Figure-4 having 3 axles and the 3rd axle (222) being the steering axle enters its turning circle, the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi trailer axle center (WB) is between the mid-point of the 1 st axle (220) and the 2nd axle (221) and the place where the motor vehicle and the semi-trailer is coupled (KP). While the towing vehicle and the semi-trailer (A) vehicle is performing the stationary state turn corresponding to a 25-meter turning circle radius at a constant speed of 5 km/h, the semi-trailer vehicle (A) turning circle (R) defined by the backmost outer edge of the semi-trailer (A) vehicle should be measured. This maneuver should be repeated under the same conditions only at 25 km/h ± 1 km/h speed. During these maneuvers, the backmost outer edge of the semi-trailer (A) vehicle traveling at 25 km/h ± 1 km/h speed should not go outside the turning circle (R) defined by that of the speed of more than 0.6 m at a constant speed of 5 km/h.

R= 12.5 m & r = 5.3 m & Umax ^£ 0.6 m

The distance from the place where the motor vehicle and the semi-trailer is coupled to the semi trailer axle center (WB) measurement of the semi-trailer vehicle (A) should satisfy the formula related to turning circle (R) limit measurements to be provided by semi-trailer (A) vehicles shared in Regulation 1230/2012 and given below in Figure-5. In this formula W expresses the width of the semi-trailer vehicle (A).

WB<[(12.50-2.04) ² -(5.30+1/2W) ² ] ^1/2

As an example, in the case when the above formula is applied when the width (W) of a standard semi-trailer vehicle (A) except special edition semi-trailer vehicles (A) is maximum 2550 mm, the maximum distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement which a semi-trailer vehicle (A) must have so that it can move within the limits and conditions of turning circle (R) regulation limits which are described in Regulation 1230/2012 becomes WB ^£ 8135 mm after calculation. According to this calculation, for a semi-trailer vehicle (A) having width (W) 2550 mm, the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement of the semi-trailer vehicle (A) to be fabricated so that it can move conforming to the turning circle (R) described in Regulation 1230/2012 must be less than 8135 mm.

Since they cannot move within the turning circle (R) regulation limits and conditions described in Regulation 1230/2012, semi-trailer vehicles (A) whose said distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement does not satisfy the formula in Regulation 1230/2012, for those semi-trailer vehicles (A) which do not satisfy the formula shared in Regulation 1230/2012 to turn within the above mentioned turning circle (R), the leading solutions in current applications necessitate the 3rd axle (222) to be able to be raised or the 3rd axle (222) again to be the steering axle. In case the said 3rd axle (222) is applied to the semi-trailer vehicle (A) as a steering axle, the steering axle, due to its nature, at any moment in driving direction becomes the turning circle (R), it is not included in the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement since it will support the movement of the semi-trailer vehicle (A) within its turning circle (R). Thus, the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement becomes in the middle of the 1st axle (220) and the 2nd axle (221), and the semi-trailer vehicle (A) can move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012. However, at this application, disadvantageous situations such as steering axle being expensive, serviceability, maintenance and assembly being more difficult as compared to a standard axle occur.

In another existing solution in which the 3rd axle (222) is applied to the semi-trailer vehicle (A) as a raisable axle, when the raisable axle is active since the 3rd axle (222) will not touch the ground, the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement becomes between the 1st axle (220) and the 2nd axle (221), and satisfies the formula shared in Regulation 1230/2012. Thus, the movement of the semi-trailer vehicle (A) whose 3rd axle (222) is raisable within turning circle (R), the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement is between the 1st axle (220) and the 2nd axle (221) when raising the 3rd axle (222) is active; and the semi-trailer vehicle (A) can move within the turning circle (R) Regulation limits and conditions described in Regulation 1230/2012. But since this situation will be limited to the load that each axle can maximally carry, in the case of presence of a load above the maximum load that any axle can carry in the semi-trailer vehicle (A) the 3rd axle (222) raising will not be active and the semi-trailer vehicle (A) will not be able to move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012. When the said 3rd axle (222) raising is in active state, the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement will be between the 1st axle (220) and 2nd axle (221), and the semi-trailer vehicle (A) will be able to move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012, when the 3rd axle (222) raising is at passive state the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement will be on the 2nd axle (221) and the semi-trailer vehicle (A) will not be able to move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012.

Currently, for the semi-trailer vehicle (A) to be able to move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012, customer demands have not been completely met despite functions such as axles with different construction or existing axle system tires not touching the ground (axle raising) etc. have been employed. Consequently, the presence of a need for an assist system which eliminates the existing disadvantages in the prior art and the deficiency of prior art solutions have necessitated an improvement to be made in the related art.

Brief Description of the Invention

The present invention relates to an improved assist system which meets the above-mentioned requirements, eliminates all disadvantages and provides some additional advantages developed to allow turning motion within the turning circle for trailers fabricated according to the load they will carry.

Starting from prior art, the object of the invention, by means of the developed assist system, is to enable semi-trailer vehicles which do not satisfy the formula shared in Regulation 1230/2012 to move again within turning circle regulation limits and conditions described in Regulation 1230/2012.

The object of the invention is to enable a semi-trailer vehicle with a standard axle construction to move within described turning circle regulation limits and conditions by assist system even if it does not satisfy the formula shared in Regulation 1230/2012.

The object of the invention is the elimination of the need for making a special axle function in the assist system by means of control of the load exerted on the differential (driven axle) of the motor vehicle towing the semi-trailer vehicle from kingpin connection by performing load transfer between axles by suspension system’s electronic pneumatic circuit components.

Another object of the invention is the elimination of accordingly resulting high cost as well as assembly, maintenance and service difficulties by means of elimination of the need for a special axle function by the aid of assist system.

Another object of the invention is to provide measurement of pressurized air line pressure by means of pressurized air measuring device used in assist system.

Another object of the invention is to provide to transmit pressurized air value to the controller by means of the air bag pressure measurement line included in the assist system.

Another object of the invention is to provide control and comparison of pressurized air between axles by means of the load control valve included in the assist system.

Another object of the invention is to provide control by the load control valve of pressurized air inside the 3rd axle air bag by means load control valve 3rd axle air bag supply lines included in the assist system.

Another object of the invention is to provide conduction of pressurized air required by the load control valve from the air tank by means of the load control valve supply line included in the assist system.

Another object of the invention is to provide interconnection of the 1st and the 2nd axle air bags line by means of load control valve transfer lines used in the assist system.

Another object of the invention is to provide measurement of wheel rotation speed of the axle to be load transferred by means of right and left wheel speedometers included in the assist system.

Another object of the invention is to provide increasing the traction in the motor vehicle differential by means of balanced control of the load exerted on motor vehicle differential coupled to the semi trailer by the assist system and obstructing wheel spin of motor vehicle differential on slippery grounds especially on inclined roads, drivability and balancing of braking forces.

The structural and characteristic features of the invention and all of its advantages will be more clearly understood by referring to the figures given below and the detailed description written by referring to these figures, therefore evaluation should be made by considering these figures and the detailed description.

Brief Description of Figures

The present invention should be evaluated together with the figures whose description is given below in order for configuration and advantages with the additional members so that its advantages can be understood in the best manner.

Figure-1 is the schematic overall view of the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center in a prior art 3-axle semi-trailer vehicle, Figure-2 is the schematic overall view of the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center of a prior art semi-trailer vehicle with 3 axles and the 3rd axle raising being active when it enters the turning circle,

Figure-3 is the schematic overall view of the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center of a prior art semi-trailer vehicle with 3 axles and the 3rd axle raising being passive when it enters the turning circle,

Figure-4 is the schematic overall view of the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center of a prior art semi-trailer vehicle with 3 axles and the 3rd steering axle when it enters the turning circle,

Figure-5 is the schematic overall view of the turning circle limit measurements which are shared in Regulation 1230/2012 and which semi-trailer vehicles must satisfy,

Figure-6 is the schematic overall view of the electro pneumatic circuit schematic diagram belonging to the balancing system of the invention,

Figure-7 is the schematic overall view of the semi-trailer vehicle.

Reference Numbers

100. Assist system

101. Air tank

102. Controller

103. Pressurized air measurement line

104. Air bag pressure measurement line

105. Load control valve

1061 . The 3rd axle left air bag

1062. The 3rd axle right air bag 1071 . The 2nd axle left air bag 1072. The 2nd axle right air bag

1081 . The 1 st axle left air bag

1082. The 2nd axle right air bag

109. Control valve supply line

110. Load control valve right 3rd axle air bag supply line

111. Load control valve left 3rd axle air bag supply line

112. Load control valve supply line

113. Left 1 st and 2nd axle air bag connection line

114. Right 1st and 2nd axle air bag connection line

115. Load control valve right transfer line

116. Load control valve left transfer line

117. Differential

118. Right wheel speedometer

119. Left wheel speedometer

220. The 1st axle

221. The 2nd axle 223. The 3rd axle

KP. The place where the motor vehicle and the semi-trailer is coupled W. Width of vehicle

WB. The distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center

R. Turning circle

R1. Turning circle radius

A. Semi-trailer vehicle

Detailed Description of the Invention

In this detailed description, the assist system (100) developed to allow the turning motion within the turning circle (R) of the trailers of the invention manufactured according to the load that they will carry is only an example intended for better understanding of the subject and it is being explained so as not to form any limiting effect.

By means of the assist system (100) of the invention, even when a semi-trailer vehicle (A) with a standard axle construction does not satisfy the formula (R= 12.5 m & r = 5.3 m & Umax-0.6 m) shared in Regulation 1230/2012, it can move within the turning circle (R) regulation limits and conditions described in Regulation 1230/2012 (WB£[(12.50-2.04) ² -(5.30+1/2W) ² ] ^1/2 ). In the assist system (100) developed to this end, control of the load exerted on the motor vehicle differential (driven axle) which tows the semi-trailer vehicle (A) from the kingpin connection a special axle function has not been made to enable to move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012 but instead by making load transfer between axles, has been controlled by the electronic pneumatic circuit components of the suspension system shown in Figure-6.

The semi-trailer vehicle (A) possessing the said assist system (100) shown in Figure-7 basically includes the 1st axle (220), the 2nd axle (221), the 3rd axle (222), air tank (101), load control valve (105) and the controller (102). In the said assist system (100), pressurized air required by circuit components used in the electro pneumatic connection is being stored for use inside the air tank (101). The said 1st axle (220) comprises the 1st axle left air bag (1081) and the 1st axle right air bag (1082) in which pressurized air is stored. The said 2nd axle (221) comprises the 2nd axle left air bag (1071), the 2nd axle right air bag (1072) in which pressurized air is stored. The said 3rd axle (222) comprises the 3rd axle left air bag (1061), the 3rd axle right air bag (1062) in which pressurized air is stored. The said 3rd axle left air bag (1061) comprises the pressurized air measuring device (103) which measures the pressurized air line pressure to which it is connected. The said pressurized air measuring device (103) conducts the measurement data via the air bag pressure measurement line (104) to the controller (102) which performs the measurements and provides communication in the assist system (100). The said load control valve (105) controls whether or not the value is within limits by adjusting the axle which utilizes the pressurized air within the 1st axle left air bag (1081), the 1st axle right air bag (1082), the 2nd axle left air bag (1071), the 2nd axle right air bag (1072), the 3rd axle left air bag (1061) and the 3rd axle right air bag (1062) of the semi-trailer vehicle (A) according to the maximum load capacity that it will carry.

The pressurized air required by the said load control valve (105) is being conducted from the air tank (101) by the control valve supply line (109). The said load control valve (105) controls the 3rd axle right air bag (1062) via load control valve right 3rd axle air bag supply line (110); the 3rd axle left air bag (1061) via load control valve left 3rd axle air bag supply line (111). The pressurized air required by the said load control valve (105) is being conducted from the air tank (101) by the load control valve supply line (112) via the controller (102). The right 1st and 2nd axle air bag connection line (114) between the left 1st and 2nd axle air bag connection line (113), the 2nd axle left air bag (1071) and the 1st axle left air bag (1081) provides the pressurized air between the 2nd axle right air bag (1072) and the 1st axle right air bag (1082) equally. The pressurized air coming from the load control valve (105) to the said left 1st and 2nd axle air bag connection line (113) is being conducted by the load control valve left transfer line (116). The pressurized air coming from the load control valve (105) to the said right 1st and the 2nd axle air bag connection line (114) is being conducted by the load control valve right transfer line (115). To monitor right wheel rotation speed of the 3rd axle (222) and to conduct to the controller (102) there exists a right wheel speedometer (118); and to monitor left wheel rotation speed of the 3rd axle (222) and to conduct to the controller (102) there exists a left wheel speedometer (119).

While the semi-trailer vehicle (a) not satisfying the formula in Regulation 1230/2012 is cruising at traffic on a flat road, values measured by the right wheel speedometer (118) and left wheel speedometer (119) are equal to each other. While the semi-trailer vehicle (A) not satisfying the formula shared in Regulation 1230/2012 is cruising in traffic on a flat road, at the moment when it enters a turning circle (R) described in Regulation 1230/2012 since the wheel speed at the inner side of the circle (R) with respect to the rotation direction will be different from the wheel speed at the outer side of the circle (R) this difference causes the values measured by the right wheel speedometer (118) and left wheel speedometer (119) to be different to each other. In this situation, speed data measured by the right wheel speedometer (118) and the left wheel speedometer (119) and conducted to the controller (102) become different and thus the controller (102) detects that the semi-trailer vehicle (A) has started to enter the turning circle (R) and conducts this data to the load control valve (105). In the meanwhile, air maximum adjustment values of the pressurized air data inside the air bags located on the 1st axle (120), 2nd axle (221) and 3rd axle (122) found by load control valve (105) and controller (102) circuit components are in a state of being determined according to axle capacity. Loads which can be carried by the 1st axle (220) and the 2nd axle (221), and maximum allowable loads are in the amount of maximum 130% of the adjusted loads or they are within the limits determined by axle manufacturer. The maximum value of speeding of the 1st axle (220) and the 2nd axle (221) in a state of being 130% loaded is 30 km/h or it is the speed limit in the amount as determined by the axle manufacturer. The said load control valve (105) controls the pressurized air inside the 3rd axle right air bag (1062) via load control valve right 3rd axle air bag supply line (110), and controls the pressurized air inside the 3rd axle left air bag (1061) via load control valve left 3rd axle air bag supply line (111).

The said load control valve (105) drains the pressurized air inside the 3rd axle right air bag (1062) via load control valve right 3rd axle air bag supply line (110), and conducts pressurized air in the same quantity as it had drained to the right 1st and 2nd axle air bag connection line (114) via load control valve right transfer line (116). The said load control valve (105) drains the pressurized air inside the 3rd axle left air bag (1061) via load control valve left 3rd axle air bag supply line (111), and conducts pressurized air in the same quantity as it had drained to the left 1st and 2nd axle air bag connection line (113) via load control valve left transfer line (115).

The maximum value of the pressurized air conducted to the right 1st and 2nd axle air bag connection line (113) via said load control valve right transfer line (115) and conducted to left 1st and 2nd axle air bag connection line (114) via load control valve left transfer line (116) is up to 130% excess of the maximum load that the 1st axle (220) assembly and the 2nd axle (221) assembly can carry or it is of the quantity within the limits as determined by axle manufacturer. This operation is performed automatically completely independent from the user by the assist system (100).

During conduction of pressurized air that is present at the 3rd axle (222) to the 1st axle (220) and 2nd axle (221) through said load control valve (105), being 130% excess of the maximum load that the 1st axle (220) and the 2nd axle (221) can carry or of the quantity within the limits as determined by axle manufacturer is determined by the controller (102) and following the determination this data is automatically conducted to the load control valve (105). In this situation, conduction of pressurized air that is present at the 3rd axle (222) to the 1st axle (220) and the 2nd axle (221) through load control valve (105) with respect to the data conducted by the controller (102) is being obstructed. Thus, any damage that can occur on the axles, and thereby accidents and life losses are avoided.

Upon conduction of pressurized air by the said load control valve (105) that is present inside the 3rd axle left air bag (1061), the 3rd axle right air bag (1062) which the 3rd axle (222) comprises to the air bags present on the 1st axle (220) and the 2nd axle (221), at the moment when the semi trailer vehicle (A) which does not satisfy the formula shared in Regulation 1230/2012 enters turning circle (R) since the load on the differential (117) (driven axle) will increase in direct proportion with the conducted load, center of gravity of the semi-trailer vehicle (A) shifts between the 1st axle (220) and the 2nd axle (221). Thus, upon operation of the system, at the moment when the semi-trailer vehicle (A) having a standard axle construction and which does not involve the prior art risks and which does not satisfy the formula shared in Regulation 1230/2012 enters the turning circle (R), it will be a value satisfying the formula shared in Regulation 1230/2012, subsequently when the semi-trailer vehicle (A) enters turning circle (R) ability to move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012 will be provided.

When the semi-trailer vehicle (A) which does not satisfy the formula shared in Regulation 1230/2012 exits the turning circle (R), values measured by the right wheel speedometer (118) and the left wheel speedometer (119) become the same value with each other and this data is detected by the controller (102) to be conducted to the load control valve (5). When the data that the semi trailer vehicle (A) which does not satisfy the formula shared in Regulation 1230/2012 has exited the turning circle (R) comes to the load control valve (105), due to the fact that the semi-trailer vehicle (A) is no longer in the turning circle (R), upon automatic engagement of a reverse load transfer system, the pressurized air conducted to the 1st axle left air bag (1081), the 1st axle right air bag (1082), the 2nd axle left air bag (1701) and the 2nd axle right air bag (1072) located on the 1st axle (220) and the 2nd axle (221); to the 3rd axle left air bag (1061) and the 3rd axle right air bag (1062) included in the 3rd axle (222) by the load control valve (105); to the load control valve right transfer line (115) and load control valve right 3rd axle air bag supply line (110) and load control valve left 3rd axle air bag supply line (111) via load control valve left transfer line (116) is being transferred.

Loads exerted on the differential (117) (driven axle) of the motor vehicles which provide progression of the semi-trailer vehicle (A) cruising in traffic must be balanced with each other. Since the load exerted on motor vehicle differential (117) (driven axle) coupled to the semi-trailer (A) together with the said assist system (100) is controlled in a balanced manner traction on motor vehicle differential (117) (driven axle) is increased and especially on inclined roads motor vehicle differential (117) (driven axle) entering wheel spin on slippery grounds is hindered, drivability is provided and braking forces are balanced.

To provide turning circle (R) regulation limits and conditions described in Regulation 1230/2012, although it is a solution to render the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement long, semi-trailer vehicle (A) with a longer than normal conditions distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement the load exerted on the differential (117) (driven axle) of the motor vehicle which provides progression cruising in traffic; since the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement of the semi-trailer vehicle (A) is long, much less load will be exerted and in this situation motor vehicle differential (117) (driven axle) traction will be lowered and it will involve wheel spin on slippery grounds. In order to satisfy turning circle (R) regulation limits and conditions described in Regulation 1230/2012 with the said assist system (100) to render the requirement for the distance from the place where the motor vehicle and the semi-trailer is coupled to the semi-trailer axle center (WB) measurement long has been eliminated.

The said assist system (100) can be used in all semi-trailer vehicles (A) which cannot move within turning circle (R) regulation limits and conditions described in Regulation 1230/2012.

For all semi-trailer vehicles (A) which cannot move with the said assist system (100) within turning circle (R) regulation limits and conditions described in Regulation 1230/2012, it has been made possible for them to be able to move without requiring the use of steering axle within turning circle (R) regulation limits and conditions described in Regulation 1230/2012.

For all semi-trailer vehicles (A) which cannot move with the said assist system (100) within turning circle (R) regulation limits and conditions described in Regulation 1230/2012, it has been made possible for them to be able to move without requiring the use of axle raising within turning circle (R) regulation limits and conditions described in Regulation 1230/2012. In the assist system (100) of the invention, pressurized air 1st axle (220) and 2nd axle (210) at the last axle of the semi-trailer vehicle (100) are being controlled with respect to their capability to carry the maximum weight and air transfer between axles is performed automatically and independently from the user without exceeding allowable upper limits. In the assist system (100) of the invention, due to the risks of accident, loss of property and life that will occur in the event when the speed of the vehicle exceeds 30 km/h or the limit determined by the axle manufacturer while pressurized air is being transferred at the last axle of the semi-trailer vehicle (A), load pressurized air transfer is not being affected and this is being controlled automatically independently from the user.

In the assist system (100) of the invention, air transfer between axles is performed independently from the user and automatically at the moment when the semi-trailer vehicle (A) enters the turning circle (R) and it is being returned to its original state again automatically at the moment when the semi-trailer vehicle (A) exits from the turning circle (R).

In the assist system (100), the entrance of the semi-trailer vehicle (A) into the turning circle (R) is automatically detected by the circuit components that it comprises.