Method and system for load transfer in a vehicle

Abstract

Method for load transfer in a vehicle (1) with an axle configuration (X1, X2, X3, X4, CD; 250) comprising at least two drive axles (X2, X3) and at least one trailing axle (X4), wherein the axle configuration comprises a central differential arrangement (CD; 250) providing a locked state and an unlocked state for the at least two drive axles (X2, X3), wherein the drive axles (X2, X3) rotate at substantially the same speed in the locked state, comprising the following steps: - Transfer (S1) of a load from the at least one trailing axle (X4) to the at least two drive axles (X2, X3), wherein the step of transferring (S1) the load from the at least one trailing axle (X4) takes place when the central differential assembly (CD) is in an unlocked state; - Locking of the central differential assembly (CD; 250); and - Transferring a load between the at least two drive axles (X2, X3) after the load has been transferred from the at least one trailing axle (X4) to the at least two drive axles (X2, X3) and after the central differential arrangement (CD; 250) has been locked.

Description

TECHNICAL AREA

[0001] The invention relates to a method for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, according to claim 1. The invention also relates to a system for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle. The invention also relates to a vehicle. Furthermore, the invention relates to a computer program and a computer program product. BACKGROUND

[0002] For heavy vehicles, such as trucks, there is a function that consists of transferring the load in an axle assembly to the primary drive axle in order to increase traction on the primary drive axle when necessary.

[0003] Load transfer on a tandem-driven triple-axle assembly, comprising two drive axles and one trailing axle, requires transferring the load from the trailing axle to the two driven axles and then from the secondary to the primary drive axle. The vehicle's center differential assembly is configured to provide a locked state for the two drive axles before the load transfer function is requested. Locking the center differential assembly is intended to prevent the axle receiving a reduced load from starting to rotate when the load is transferred between the drive axles, and the loaded axle from effectively stopping rotating.

[0004] WO 2014 / 070083 A1 discloses a system for controlling load transfers in a vehicle. This includes sending control signals from a control device to a load transfer control mechanism, which is connected to the axle assembly, and controlling the transfer to the axle assembly by means of a control mechanism. The axle configuration comprises two drive axles and one trailing axle in a triple axle assembly arrangement. The load transfer is carried out in two steps: first from the trailing axle to the two drive axles, and then from one drive axle to the other.

[0005] Document WO 2011 / 075 014 A1 further discloses an anti-slip support system with an activation device, wherein a differential lock for two drive axles is described as predetermined anti-slip functions.

[0006] DE 10 2014 022 022 A1 teaches a device and a method for solving traction problems in multi-axle vehicles, wherein loads can be shifted between driven and non-driven axles to increase a static friction force.

[0007] From a non-patent publication entitled “Product information rear axle suspension RADDT12”, dated May 21, 2010, separately implemented measures such as an axle lift for a trailing axle and an increase in the axle load on a first drive axle are known for a vehicle with an axle configuration that includes two drive axles and a trailing axle as well as a central differential arrangement.

[0008] However, there is a need to further improve load transfer for axle configurations that include at least two drive axles and at least one trailing axle. TASKS OF INVENTION

[0009] One object of the present invention is to provide a method for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, which enables better driving behavior of the vehicle.

[0010] Another object of the present invention is to provide a load transfer system in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, which enables better driving performance of the vehicle. BRIEF SUMMARY OF THE INVENTION

[0011] These and other tasks arising from the description below are achieved by a method, a system, a vehicle, a computer program, and a computer program product as set forth in the accompanying independent claims. Preferred embodiments of the method and the system are defined in the accompanying dependent claims.

[0012] In particular, an object of the invention is achieved by a method for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle. The axle configuration includes a central differential assembly that provides a locked state and an unlocked state for the at least two drive axles. The method comprises the step of transferring a load from the at least one trailing axle to the at least two drive axles. The step of transferring the load from the at least one trailing axle occurs when the central differential assembly is in an unlocked state. It is thus possible to transfer a load from the trailing axle to the drive axles without having to lock the central differential, thereby enabling normal driving.Driving at higher speeds and cornering is improved, as the drive axle traction is not affected by a potential locking of the center differential. This avoids unnecessary locking of the center differential, thus improving the vehicle's handling.

[0013] According to the invention, the method comprises the step of locking the central differential assembly before transferring a load between the at least two drive axles, after the load has been transferred from the at least one trailing axle to the at least two drive axles, if this is desired, for example, due to the tractive effort. This locks the central differential as needed, thereby ensuring safe vehicle handling in conjunction with load transfer between the drive axles.

[0014] According to one embodiment of the method, the axle configuration comprises two drive axles and one trailing axle of a triple axle assembly arrangement.

[0015] In particular, an object of the invention is achieved by a load transfer system in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle. The axle configuration includes a central differential assembly that provides a locked state and an unlocked state for the at least two drive axles. The system includes means for transferring a load from the at least one trailing axle to the at least two drive axles. The means for transferring a load from the at least one trailing axle are arranged to be activated when the central differential assembly is in an unlocked state.

[0016] According to the invention, the system comprises means for locking the central differential arrangement before transferring a load between the at least two drive axles, after the load has been transferred from the at least one trailing axle to the at least two drive axles, if this is desired, for example, in view of the traction power.

[0017] According to one embodiment of the system, the axle configuration comprises two drive axles and one trailing axle of a triple axle assembly arrangement.

[0018] The system is adapted to execute the procedures outlined here.

[0019] The system according to the invention offers the advantages according to the corresponding method. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For a better understanding of the present invention, reference is made to the following detailed description when read in conjunction with the accompanying drawings, where the same reference numerals in the various views refer to the same parts. The drawings show: Fig. 1 schematically a side view of a vehicle with an axle configuration comprising two drive axles and a trailing axle, according to an embodiment of the present invention; Fig. 2. Schematic top view of the parts of the vehicle in Fig. 1; Fig. 3 schematically the load transfer from the trailing axle to the drive axles according to an embodiment of the present invention; Fig. 4 schematically a system for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, according to an embodiment of the present invention; Fig. 5 schematically a block diagram of a method for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, according to an embodiment of the present invention; and Fig. 6 schematically a computer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In the following, the term "connection" refers to a communication link, which may be a physical link, such as an optoelectronic communication line, or a non-physical link, such as a wireless link, e.g. a radio link or a high-frequency link.

[0022] Fig. Figure 1 schematically depicts a vehicle 1 according to an embodiment of the present invention. The vehicle is located on a road R. The exemplary vehicle 1 is a heavy vehicle in the form of a truck. The vehicle according to the present invention could be any vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, and which enables load transfer between the trailing axle(s) and the drive axles. In this embodiment, the vehicle 1 has a front axle X1, a first driven rear axle X2, a second driven rear axle X3, and a rear trailing axle X4. The vehicle is equipped with a system I for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle according to the present invention.The first driven rear axle X2 forms a first drive axle X2, and the second rear axle X3 forms a second drive axle X3 of vehicle 1. The two drive axles X2, X3 and the trailing axle X4 of the axle configuration are part of a triple axle assembly arrangement.

[0023] Fig. 2 is a schematic top view of the vehicle made of Fig. Figure 1 shows its chassis and air suspension system. The vehicle comprises a frame 2, 3, a front axle X1 with opposed front wheels RF, LF, a first driven rear axle X2 with opposed drive wheels RD1, LD1, a second driven rear axle X3 with opposed drive wheels RD2, LD2, and a trailing rear axle X4 with opposed trailing axle wheels RT, LT. The two drive axles X2, X3 and the single trailing axle X4 of the axle configuration are part of a triple axle assembly.

[0024] The vehicle is further equipped with an air suspension system comprising a spring element configuration. This configuration includes a first spring element unit B1, located on the right side near the front axle X1, and a second spring element unit B2, located on the left side near the front axle X1. Each of the first and second spring element units B1 and B2 comprises a pair of spring elements connected by compressed air, with one spring element located on each side of axle X1.

[0025] The spring assembly configuration further comprises a third spring assembly B3, located on the right side near the first driven rear axle X2, and a fourth spring assembly B4, located on the left side near the driven rear axle X2. The third and fourth spring assembly units B3 and B4 each comprise a pair of spring bodies connected to each other, with one spring body located on each side of axle X2.

[0026] The spring assembly configuration further includes a fifth spring assembly B5, located on the right side near the second driven rear axle X3, and a sixth spring assembly B6, located on the left side near the second driven rear axle X3. The fifth and sixth spring assembly units B5 and B6 each comprise a pair of spring bodies connected to each other, with one spring body located on each side of axle X3.

[0027] The spring assembly configuration further includes a seventh spring assembly B7, located on the right side near the rear trailing axle X4, and an eighth spring assembly B8, located on the left side near the rear trailing axle X4. The seventh and eighth spring assembly units B7 and B8 each comprise a pair of springs connected by compressed air, with one spring on each side of axle X4.

[0028] The respective spring units B1 to B8 are located between the vehicle frame 2, 3 and the respective axles, which allows the vehicle body to be raised and lowered by regulating air in the spring units.

[0029] The spring body configuration further includes a spring body unit B9, which is arranged in conjunction with the trailing axle X4 to raise and lower the trailing axle X4 for load transfer.

[0030] The air suspension system further comprises an air valve configuration V according to an embodiment of the present invention. The air valve configuration V is connected to the spring body configuration, i.e., to the spring body units B1, B2, B3, B4, B5, B6, B7, B8, B9, and is suitable for regulating the air pressure in the respective spring body units B1, B2, B3, B4, B5, B6, B7, B8, B9 of the spring body configuration.

[0031] The vehicle also includes an air pressure source configuration A to supply compressed air to the air valve configuration V.

[0032] The air pressure in the third and fourth spring body units B3, B4 of the first driven rear axle X2 and the air pressure in the fifth and sixth spring body units B5, B6 of the second driven rear axle are configured to be regulated for load transfer between the drive axles X2, X4.

[0033] The spring assembly further includes means for determining the load on each axle X1, X2, X3, X4 of the vehicle's axle configuration. These means for determining the load on each axle X1, X2, X3, X4 comprise sensor units arranged in conjunction with the respective spring assembly units B1 to B9.

[0034] The axle configuration includes a central differential assembly CD, which is configured to provide a locked state and an unlocked state for the two drive axles X2, X3.

[0035] The central differential arrangement CD is thus arranged to provide a locked state in which the first driven rear axle X2, i.e. the first drive axle X2, and the second driven rear axle X3, i.e. the second drive axle X3, are locked such that they rotate at substantially the same speed.

[0036] The central differential arrangement CD is further arranged to provide an unlocked state in which the first driven rear axle X2, i.e. the first drive axle X2, and the second driven rear axle X3, i.e. the second drive axle X3, can rotate independently of each other and thus relative to each other.

[0037] The axle configuration further includes a first differential element D1 to provide a differential function for the first driven rear axle X2. The first driven rear axle X2 thus comprises a right axle element X2a and a left axle element X2b, the first differential element being configured to provide a locked state in which the left and right axle elements X2a and X2b are configured to rotate at the same speed, and an unlocked state in which they can rotate relative to each other.

[0038] The axle configuration further includes a second differential element D2 to provide a differential function for the second driven rear axle X3. The second driven rear axle X3 thus comprises a right axle element X3a and a left axle element X3b, the second differential element being configured to provide a locked state in which the left and right axle elements X3a and X3b are configured to rotate at the same speed, and an unlocked state in which they can rotate relative to each other.

[0039] Vehicle 1 includes a system I for load transfer within the vehicle.

[0040] System I includes one electronic control unit 100.

[0041] System I includes the air valve configuration V.

[0042] System I includes the air pressure source configuration A.

[0043] System I comprises the means for determining the load on the respective axle X1, X2, X3, X4 of the vehicle, wherein the means are contained in the spring body configuration according to the present embodiment.

[0044] System I includes means for determining the state of the central differential assembly CD, specifically whether it is locked or unlocked. These means for determining the state of the central differential assembly CD are contained within the central differential assembly itself.

[0045] System I comprises means for transferring a load from the trailing axle X4 to the drive axles X2 and X3. The means for transferring a load include the spring unit B9 and, if applicable, the spring units B7 and B8, the valve configuration V, and the electronic control unit 100.

[0046] System I comprises means for transferring a load between the drive axes X2 and X3. These means for transferring a load between the drive axes X2 and X3 include the spring body units B3, B4, B5, and B6, the valve configuration V, and the electronic control unit 100.

[0047] The electronic control unit 100 is operationally connected to the spring assembly via connections. The electronic control unit 100 is positioned via these connections to receive signals from the spring assembly that represent data for the axle load of the respective axle, in particular the drive axles X2 and X3.

[0048] The electronic control unit 100 is operationally connected to the valve configuration V via a link. The electronic control unit 100 is positioned via this link to send signals to the valve configuration V representing data for the air pressure corresponding to the desired load in the respective spring element units for potential load transfer.

[0049] The electronic control unit 100 is operationally connected to the means for determining the state of the central differential assembly CD via a connection. The electronic control unit 100 is arranged via the connection to receive a signal from the means for determining the state of the central differential assembly CD, which represents data for the state of the central differential assembly CD.

[0050] The electronic control unit 100 is operationally connected to the central differential assembly CD via a connection. The electronic control unit 100 is positioned via this connection to send a signal to the central differential assembly CD, which represents data for locking / unlocking the central differential assembly CD. Thus, according to this embodiment, the electronic control unit 100 constitutes means 100 for locking the central differential assembly CD.

[0051] The electronic control unit 100 is arranged to process data for the state of the central differential assembly CD and data for the load of the axles.

[0052] The means for transferring a load from the trailing axle X4 to the drive axles X2, X3 are arranged to be activated when the central differential assembly CD is in an unlocked state. The means for transferring a load from the trailing axle X4 to the first and second drive axles X2, X3 are arranged to be transferred to an unlocked state with the central differential assembly CD. According to one embodiment, the electronic control unit 100 is arranged to send a signal to the spring body unit B9 to raise the trailing axle, thus lifting the trailing wheels RT, LT off the road so that they do not touch the ground or only touch the ground to a lesser extent. Such a load transfer from the trailing axle X4 to the drive axles X2, X3 can occur when improved traction is required.

[0053] If even better traction is required, load transfer between the drive axles X2 and X3 can be performed after the load has been transferred from the trailing axle X4 to the drive axles X2 and X3. The electronic control unit 100 is positioned to send a signal to the central differential assembly CD to lock it.

[0054] The means for transferring a load between the drive axles X2 and X3 are arranged to be activated when the central differential assembly CD is locked. Thus, load transfer between the drive axles X2 and X3 is arranged to occur when the central differential assembly CD is in a locked state. According to one embodiment, the electronic control unit 100 is arranged to send a signal to the air valve configuration V to regulate the pressure in the spring body units B3, B4, B5, and B6 for load transfer between the drive axles X2 and X3.

[0055] The vehicle's load transfer function can be provided in any suitable manner by any suitable means, such as hydropneumatically, electromagnetically, electrically, or the like. The suspension system can therefore be any suitable suspension system, such as a hydropneumatic suspension system, an electromagnetic suspension system, an electric suspension system, or the like.

[0056] The previously mentioned reference to Fig. The vehicle described in Figure 1 has a front axle X1 and a first driven rear axle X2, a second driven rear axle X3, and a trailing axle as a purely schematic example. The vehicle according to the present invention could be any suitable vehicle comprising at least two drive axles and at least one trailing axle.

[0057] Fig. Figure 3 schematically illustrates the load transfer from a trailing axle X4 to the drive axles X2, X3 according to an embodiment of the present invention. The left drive wheel LD1 of the first drive axle X2, the left drive wheel LD2 of the second drive axle X3, and the left trailing wheel LT of the trailing axle X4 are shown.

[0058] In a first step, i, the load is evenly transferred from the trailing axle X4 to the drive axles X2 and X3. This transfer occurs when the central differential assembly is in the unlocked state. The load transfer from the trailing axle X4 to the drive axles X2 and X3 can be achieved by lifting the trailing axle from the ground engagement position G to the ground disengagement position G.

[0059] In a second step ii, the load is transferred from the first drive axle X2 to the second drive axle X3. Before the load is transferred from the first drive axle X2 to the second drive axle X3, the central differential assembly is locked. Alternatively, and as required, the load is transferred from the second drive axle X3 to the first drive axle X2, but this occurs after the central differential assembly has been locked.

[0060] Fig. Figure 4 schematically depicts a system II for load transmission in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, according to an embodiment of the present invention. The axle configuration includes a central differential arrangement configured to provide a locked state in which at least two drive axles are arranged to rotate at the same speed, and an unlocked state in which the at least two drive axles can rotate independently.

[0061] System II includes an electronic control unit 200.

[0062] System II comprises means 210 for determining the load on the at least two drive axles and the at least one trailing axle. According to one embodiment, the means 210 for determining the load on the at least two drive axles and the at least one trailing axle comprise any suitable sensor means. According to one embodiment, the means 210 for determining the load on the at least two drive axles and the at least one trailing axle comprise pressure sensor units arranged in conjunction with the respective axles.

[0063] System II comprises means 220 for determining the state of the central differential assembly, in order to determine whether the central differential assembly is in the locked or unlocked state. According to one embodiment, the means 220 for determining the state of the central differential assembly are contained within the central differential assembly.

[0064] System II comprises means 230 for transferring a load from the at least one trailing axle to the at least two drive axles. According to one embodiment, the means 230 for transferring a load from the at least one trailing axle to the at least two drive axles comprise spring element units of an air suspension system, wherein the spring element units are arranged in conjunction with the at least one trailing axle and the at least two drive axles, and a valve configuration arranged to regulate the air pressure in the spring element units for load transfer.

[0065] System II comprises means 240 for transferring a load between the at least two drive axles. According to one embodiment, the means 240 for transferring a load between the drive axles comprise spring element units of an air suspension system, wherein the spring element units are arranged in conjunction with the at least two drive axles, and a valve configuration arranged to regulate the air pressure in the spring element units for load transfer between the drive axles.

[0066] System II includes the central differential arrangement 250 of the axle configuration.

[0067] The electronic control unit 200 is operationally connected via a connection 10 to the means 210 for determining the load on the at least two drive axles and the at least one trailing axle. The electronic control unit 100 is arranged via the connection 10 to receive signals from the means 210 that represent data for the axle load of the respective axles, in particular the two drive axles.

[0068] The electronic control unit 200 is operationally connected via a connection 20 to the means 220 for determining the state of the central differential assembly. The electronic control unit 200 is arranged via the connection 20 to receive a signal from the means 220 that represents data for the state of the central differential assembly.

[0069] The electronic control unit 200 is operationally connected via a connection 30 to the means 230 for transferring a load from the at least one trailing axle to the at least two drive axles. The electronic control unit 200 is arranged via the connection 30 to send a signal to the means 230 that represents data for the load transfer from the at least one trailing axle to the at least two drive axles.

[0070] The electronic control unit 200 is operationally connected via a connection 40 to the means 240 for transferring a load between the at least two drive axes. The electronic control unit 200 is arranged via the connection 40 to send a signal to the means 240 that represents data for the load transfer between the at least two drive axes.

[0071] The electronic control unit 200 is operationally connected to the central differential assembly 250 via a connection 50. The electronic control unit 200 is arranged via the connection 50 to send a signal to the central differential assembly 250, which represents data for locking / unlocking the central differential assembly 250. Thus, according to this embodiment, the electronic control unit 200 constitutes means 200 for locking the central differential assembly 250.

[0072] The electronic control unit 200 is arranged to process data for the state of the central differential assembly and data for the load of the axles.

[0073] The means 230 for transferring a load from the at least one trailing axle to the at least two drive axles are arranged to be activated when the central differential assembly 250 is in an unlocked state. Thus, the load transfer from the at least one trailing axle to the at least two drive axles is arranged to occur when the central differential assembly 250 is in an unlocked state. Such a load transfer from the at least one trailing axle to the at least two drive axles can occur when improved traction is required.

[0074] If even better traction is required, load transfer between the at least two drive axles is arranged to occur after the load has been transferred from the at least one trailing axle to the at least two drive axles. The electronic control unit 200 is arranged to send a signal to the central differential assembly 250 to lock the central differential assembly 250.

[0075] The means 240 for transferring a load between the at least two drive axles are arranged to be activated when the central differential assembly 250 is locked. Thus, the load transfer between the at least two drive axles is arranged to be transmitted when the central differential assembly 250 is in a locked state.

[0076] Fig. Figure 5 schematically depicts a block diagram of a method for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle, according to an embodiment of the present invention. The axle configuration includes a central differential arrangement that provides a locked state and an unlocked state for the at least two drive axles.

[0077] According to the invention, the method for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle includes a step S1. In this step, the load is transferred from the at least one trailing axle to the at least two drive axles, wherein the step of transferring the load from the at least one trailing axle takes place when the central differential is in an unlocked state.

[0078] According to one embodiment, the method includes the step of locking the central differential arrangement before transferring a load between the at least two drive axles, after the load has been transferred from the at least one trailing axle to the at least two drive axles, if this is desired, for example, in view of the traction power.

[0079] According to one embodiment of the method, the axle configuration comprises two drive axles and one trailing axle of a triple axle assembly arrangement.

[0080] With reference to Fig. Figure 6 shows a diagram of a device 500. One of the control units 100, 200, which refers to Fig. 2 and Fig.As described in section 4, the device 500 can, according to one embodiment, comprise a non-volatile memory 520, a data processing unit 510, and a read / write memory 550. The non-volatile memory 520 has a first memory section 530 in which a computer program, such as an operating system, is stored to control the function of the device 500. The device 500 also includes a bus controller, a serial communication port, I / O means, an A / D converter, a time and date input and transfer unit, an event counter, and an interrupt controller (not shown). The non-volatile memory 520 also has a second memory section 540.

[0081] A computer program P is provided that includes routines for load transfer in a vehicle with an axle configuration comprising at least two drive axles and at least one trailing axle. The axle configuration includes a central differential assembly that provides a locked state and an unlocked state for the at least two drive axles. The program P includes routines for transferring a load from the at least one trailing axle to the at least two drive axles, whereby the load transfer from the at least one trailing axle occurs when the central differential is in an unlocked state. The program P includes routines for locking the central differential assembly before transferring a load between the at least two drive axles, after the load has been transferred from the at least one trailing axle to the at least two drive axles, if, for example, this is necessary.This is desirable in view of the traction performance. The computer program P can be stored in an executable form or in a compressed state in a separate memory 560 and / or in a read / write memory 550.

[0082] When it is stated that the data processing device 510 performs a certain function, it is understood that the data processing device 510 executes a certain part of the program stored in the separate memory 560, or a certain part of the program stored in the read / write memory 550.

[0083] The data processing device 510 can communicate with a data communication port 599 via a data bus 515. The non-volatile memory 520 is suitable for communication with the data processing device 510 via a data bus 512. The separate memory 560 is suitable for communication with the data processing device 510 via a data bus 511. The read / write memory 550 is suitable for communication with the data processing device 510 via a data bus 514. Connections to the control units 100, for example, can be connected to the data communication port 599.

[0084] When data is received at data port 599, it is temporarily stored in the second memory section 540. Once the received input data has been temporarily stored, the data processing device 510 is configured to execute code as previously described. The signals received at data port 599 can be used by the device 500, which transfers a load from the at least one trailing axle to the at least two drive axles, with the load transfer from the at least one trailing axle occurring when the center differential is in an unlocked state.The signals received at data port 599 can be used by device 500 to lock the central differential arrangement before transferring a load between the at least two drive axles, after the load has been transferred from the at least one trailing axle to the at least two drive axles, if this is desired, for example, in view of the traction power.

[0085] Parts of the procedures described here can be performed by the device 500 using the data processing device 510, which executes the program stored in the separate memory 560 or the read / write memory 550. When the device 500 executes the program, parts of the procedures described here are performed.

[0086] The above description of the preferred embodiments of the present invention has been provided for illustration and description purposes.

Claims

[1] A method for load transfer in a vehicle (1) having an axle configuration (X1, X2, X3, X4, CD; 250) comprising at least two drive axles (X2, X3) and at least one trailing axle (X4), the axle configuration comprising a central differential arrangement (CD; 250) providing a locked state and an unlocked state for the at least two drive axles (X2, X3), the drive axles (X2, X3) rotating at substantially the same speed in the locked state, comprising the following steps: - transferring (S1) a load from the at least one trailing axle (X4) to the at least two drive axles (X2, X3), wherein the step of transferring (S1) the load from the at least one trailing axle (X4) occurs when the central differential arrangement (CD) is in an unlocked state; - Locking the central differential assembly (CD; 250); and - transferring a load between the at least two drive axles (X2, X3) after the load has been transferred from the at least one trailing axle (X4) to the at least two drive axles (X2, X3) and after the central differential arrangement (CD; 250) has been locked. [2] The method of claim 1, wherein the axle configuration comprises two drive axles (X2, X3) and one trailing axle (X4) of a triple axle assembly arrangement. [3] A system (I; II) for load transfer in a vehicle (1) having an axle configuration (X1, X2, X3, X4, CD; 250) comprising at least two drive axles (X2, X3) and at least one trailing axle (X4), the axle configuration comprising a central differential arrangement (CD) providing a locked state and an unlocked state for the at least two drive axles (X2, X3), the drive axles (X2, X3) rotating at substantially the same speed in the locked state, the system comprising: - means for transferring a load from the at least one trailing axle (X4) to the at least two drive axles (X2, X3), wherein the means (230) for transferring the load from the at least one trailing axle (X4) are arranged to be activated when the central differential arrangement (CD; 250) is in an unlocked state; - means for locking the central differential assembly (CD; 250) before transferring a load between the at least two drive axles (X2, X3) and after the load has been transferred from the at least one trailing axle (X4) to the at least two drive axles (X2, X3); and - means for transferring a load between the at least two drive axles (X2, X3) after the load has been transferred from the at least one trailing axle (X4) to the at least two drive axles (X2, X3) and after the central differential arrangement (CD; 250) has been locked. [4] The system of claim 3, wherein the axle configuration comprises two drive axles (X2, X3) and one tag axle (X4) of a triple axle assembly. [5] Vehicle (1) comprising a system (I) according to claim 3 or 4. [6] Computer program (P) for load transfer in a vehicle (1) with an axle configuration comprising at least two drive axles (X2, X3) and at least one trailing axle (X4), characterized by in that the computer program (P) comprises program code which, when running on an electronic control unit (100) or another computer (500) connected to the electronic control unit (100), causes the electronic control unit (100) to carry out a method according to one of claims 1 to 2. [7] Computer program product, characterized by that it comprises a digital storage medium which stores the computer program according to claim 6.

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