Method for selecting a differential gear to be locked

Abstract

In a method for selecting a differential gear (5.1, 5.2) to be locked from a plurality of differential gears (5.1, 5.2) in a vehicle (17), a value comparison (2) is automatically carried out when a differential locking command (1) is present, wherein, within the scope of the value comparison (2), the respective stress values ​​(6.1, 6.2, 7.1, 7.2) of the plurality of differential gears (5.1, 5.2) are compared with each other, wherein, subsequently, from the plurality of differential gears (5.1, 5.2), the differential gear (5.1, 5.2) whose stress value (6.1, 6.2, 7.1, 7.2) is lowest is selected as the differential gear (5.1, 5.2) to be locked.

Description

Technical field

[0001] The invention relates to a method for selecting a differential gear to be locked according to the preamble of claim 1. The invention further relates to a system, a vehicle, a computer program and a computer-readable medium according to the dependent claims. State of the art

[0002] In vehicles with drive axles, the drive axles often include differential gears, also known as axle differentials. These differential gears can be locked in some vehicles; this is then referred to as a differential lock. When differential gears are locked, increased wear occurs within the differential gears, for example, because both wheels on the axle rotate at the same speed when cornering.

[0003] In vehicles with multiple driven axles, it is generally possible for each axle to have its own differential, and for all differentials to be lockable if necessary. This can lead to uneven wear of the differentials, particularly where one differential is subjected to more stress than another, which can then result in increased maintenance and repair costs for the vehicle.

[0004] Vehicles are known in which the selection of the differentials to be locked follows a predetermined sequence. However, a disadvantage of these known systems is that they are not able to reliably prevent uneven wear. General description of the invention

[0005] The object of the invention is to eliminate or at least reduce the disadvantages of the prior art.

[0006] The problem is solved by a method for selecting a differential to be locked from a plurality of differentials in a vehicle. When a differential locking command is issued, a value comparison is automatically performed, comparing the respective stress values ​​of the plurality of differentials. Subsequently, the differential with the lowest stress value is selected as the differential to be locked. In a special case of the method, the vehicle comprises two differentials. When a differential locking command is issued, the differential with the lowest stress value is preferably always selected as the differential to be locked.In this way, the stresses on the differential gears are distributed evenly over the vehicle's lifetime, thus reducing maintenance and repair costs. A differential lock command is typically generated either by the driver, for example by pressing a differential lock button, or it is generated automatically when the vehicle detects that a differential lock should be activated, for example to prevent individual wheels from spinning.

[0007] In advantageous embodiments, the stress value comprises the number of actuations of the respective differential gear. For each differential gear, the number of actuations, i.e., locking cycles of the differential gear, is thus typically recorded and stored continuously, so that the number of actuations for each differential gear increases continuously over the vehicle's service life. In advantageous embodiments, the stress value corresponds to the number of actuations of the respective differential gear. In other words, the stress value is then the current number of actuations of the respective differential gear.In such cases, the respective number of actuations of the different differential gears are compared as part of the value comparison, and the differential gear with the lowest number of actuations, or in other words, the one that has been actuated (i.e., locked) the least, is selected as the differential gear to be locked.

[0008] In advantageous embodiments, the stress value comprises a number of operating hours of the respective differential gear. In advantageous embodiments, the stress value corresponds to a number of operating hours of the respective differential gear. In such a case, the respective number of operating hours of the different differential gears are compared during the value comparison, and the differential gear with the fewest operating hours is selected as the differential gear to be locked.

[0009] In advantageous embodiments, the stress value can also be calculated using a formula based on the number of actuations and the number of operating hours for each differential gear. In other words, the stress value then comprises an actuation component and an operating hour component.

[0010] In advantageous embodiments, the method comprises a locking process in which the locking differential is locked by being brought into a locked state. Advantageously, during the locking process, an automatic increase in the stress value of the locking differential is performed after the differential has been locked. Such a locking process with automatic increase in the stress values ​​of the respective locked differentials has the advantage that it ensures that the stress values, i.e., e.g., the number of actuations and / or the number of operating hours, are increased with each locking operation.

[0011] In advantageous embodiments, the number of actuations of the differential gear to be locked is automatically increased as part of the automatic value increase, preferably by a value of "1". In this case, a value for the number of actuations in a counter block of the differential gear to be locked – and typically currently locked – is typically increased by a value of "1", i.e., by one further actuation.

[0012] In advantageous embodiments, the duration of the locking state is determined as part of the automatic value increase, and this duration is automatically added to the operating hours of the differential gear being locked. This ensures that, with each locking state, the fact that the operating hours of the differential gear being locked—and thus typically locked—continuously increase is taken into account.

[0013] In advantageous embodiments, the method comprises a switching process in which the locking state of a previously locked differential is automatically terminated and a previously unlocked differential is selected as the differential to be locked when the number of operating hours of the previously locked differential exceeds the number of operating hours of the previously unlocked differential. This ensures that if a specific differential remains locked for an extended period, the system switches to another differential so that this other differential is then locked as soon as the previously locked differential has accumulated so many operating hours that it ultimately has more operating hours than another differential or differentials.In advantageous embodiments, during the switching process, the differential gear with the fewest operating hours is selected from a plurality of initially unlocked differential gears as the differential gear to be locked.

[0014] In advantageous embodiments, when the differential locking command is received, a corresponding switching pulse is automatically output for each differential gear in the plurality of differential gears, wherein, during the locking process, the respective switching pulse is preferably only directed to the differential gear to be locked. This approach simplifies the architecture of the method such that the differential locking command generates a switching pulse for each differential gear by default, and during the locking process, only the differential gear to be locked receives its corresponding switching pulse, thus blocking the other switching pulses.

[0015] The problem is further solved by a system comprising means for at least partial implementation of a method according to at least one of the aforementioned embodiments.

[0016] Such a system typically comprises at least one differential lock command generation module, which is typically suitable for generating the differential lock command and / or the switching pulses for the differential gears, and / or a value comparison module, which is suitable for performing the value comparison, and / or counter blocks for the respective differential gears, within which current values ​​for the number of actuations of the respective differential gears and current values ​​for the number of operating hours of the respective differential gears are stored and successively incremented, and / or a value increase module, which is suitable for performing the value increase, and / or a locking module, which is suitable for performing the locking process, and / or a switching module, which is suitable for performing the switching process.

[0017] In advantageous embodiments, the system is suitable for at least partially carrying out, coordinating, and / or controlling a method for selecting a differential gear to be locked from a plurality of differential gears in a vehicle according to at least one of the aforementioned embodiments. For this purpose, the system typically comprises means for carrying out, coordinating, and / or controlling a method according to at least one of the aforementioned embodiments.

[0018] Advantageously, at least some of the aforementioned modules, means, and / or blocks are implemented in the system using computer program code. In advantageous embodiments, the system, in particular at least some of the aforementioned modules, means, and / or blocks, is at least partially part of a vehicle control unit and / or a cloud. In typical embodiments, the system is a control unit, in particular a vehicle control unit.

[0019] In one embodiment of the invention, a vehicle is suitable for carrying out a method according to at least one of the aforementioned embodiments and / or comprises a system according to one of the aforementioned embodiments. For this purpose, the vehicle typically includes means for carrying out a method according to at least one of the aforementioned embodiments.

[0020] In one embodiment of the invention, a computer program comprises instructions which, when executed by a computer, cause the computer to perform one of the aforementioned methods. The computer program can also be referred to as a computer program product.

[0021] In one embodiment of the invention, a computer-readable medium comprises computer program code for carrying out one of the aforementioned methods and / or a aforementioned computer program. The term "computer-readable medium" includes, in particular but not exclusively, hard drives and / or servers and / or memory sticks and / or flash memory and / or DVDs and / or Blu-rays and / or CDs. Additionally, the term "computer-readable medium" also includes a data stream such as that generated when a computer program and / or a computer program product is downloaded from the internet. Brief description of the drawings

[0022] The invention is briefly explained below with reference to drawings, which show: Fig. 1: a schematic representation of a method according to the invention in a first embodiment, Fig. 2: a schematic representation of a method according to the invention in a second embodiment, Fig. 3: a schematic representation of a method according to the invention in a third embodiment, Fig. 4: a schematic representation of a method according to the invention in a fourth embodiment, Fig. 5: a schematic representation of a system according to the invention, Fig. 6: a schematic representation of a vehicle according to the invention. Description of preferred embodiments

[0023] Fig. Figure 1 shows a schematic representation of a method according to the invention in a first embodiment. In particular, in Fig. Figure 1 shows a method for selecting a differential gear to be locked from a plurality of differential gears in a vehicle, which includes an automatic value comparison 2. If a differential locking command 1 is present and communicated to the value comparison, then, within the framework of the value comparison 2, the respective stress values ​​of the plurality of differential gears are compared with each other and subsequently, from the plurality of differential gears, the differential gear whose stress value is lowest is selected as the differential gear to be locked.

[0024] Fig. Figure 2 shows a schematic representation of a method according to the invention in a second embodiment. As already mentioned in Fig. The method shown in 1 also includes the one described in Fig. The two methods shown involve a value comparison. Additionally, the method includes a blocking process and a value increase. The value increase is in Fig. 2 is shown as part of the locking process 3, but could also be shown as a separate process within the one in Fig. The inventive method described in point 2 must be carried out. Fig. Figure 2 shows two differential gears, 5.1 and 5.2. Furthermore, in Fig. Two stress values ​​for the differential gears 5.1 and 5.2 are shown, namely a number of actuations 6.1 of the first differential gear 5.1, a number of actuations 6.2 of the second differential gear 5.2, a number of operating hours 7.1 of the first differential gear 5.1, and a number of operating hours 7.2 of the second differential gear 5.2. Furthermore, in Fig. 2 a switching pulse 8.1 is shown, which is in Fig. The method described in section 2 is output to the first differential gear 5.1. Fig. Figure 2 shows a case in which the respective number of actuations 6.1, 6.2 of the differential gears 5.1, 5.2 are compared with each other, namely within the framework of the value comparison 2, and then the differential gear from the two differential gears 5.1, 5.2 that has the lower number of actuations 6.1, 6.2 is selected as the differential gear to be locked. The fact that Im in Fig. In the case shown in Figure 2, the first differential 5.1 is the differential with the lower number of actuations. Therefore, during the value comparison in Figure 2, the first differential 5.1 is selected as the differential to be locked, and during the locking process in Figure 3, its switching impulse 8.1 is applied to this first differential 5.1. In this case, the first differential 5.1 is locked, and the second differential 5.2 remains unlocked. Furthermore, in Figure 2, the following applies: Fig. In the case shown in section 2, the increase in value 4 increases the number of actuations 6.1 of the first differential gear 5.1 by the value "1". This increase in value is shown in Fig. 2 is symbolized by the dotted arrow between the value increase 4 and the number of actuations 6.1 of the first differential gear 5.1.

[0025] Fig. Figure 3 shows a schematic representation of a method according to the invention in a third embodiment. Fig. Figure 3 again represents a differential lock command 1, which is subjected to a value comparison 2. Furthermore, in Fig. Figure 3 again shows the locking process 3 with the value increase 4. Furthermore, the differential gears 5.1, 5.2, as well as the number of actuations 6.1, 6.2 and the number of operating hours 7.1, 7.2 of the two differential gears 5.1, 5.2 are also shown. Unlike in Fig. The embodiment shown in 2 is described in the Fig. In the exemplary embodiment shown in Figure 3, however, within the framework of the value comparison 2, a comparison was made between the number of operating hours 7.1, 7.2, and no comparison was made between the number of actuations 6.1, 6.2. In the Fig. In the case shown in Figure 3, the value comparison in Figure 2 revealed that the differential 5.2 currently has a lower number of operating hours (Figure 7.2) than the first differential 5.1. Accordingly, the second differential 5.2 was selected as the differential to be locked in the value comparison in Figure 2. Subsequently, a switching pulse (Figure 8.2) was issued to the second differential 5.2 in the locking process (Figure 3). The second differential 5.2 is thus locked, while the first differential 5.1 remains unlocked. Furthermore, in the Fig. In the embodiment shown in Figure 3, the increase in value 4 is accompanied by an increase in the number of operating hours 7.2 of the second differential gear 5.2. This increase in value is implemented in Fig. 3 is symbolized by the dotted arrow between the value increase 4 and the number of operating hours 7.2 of the second differential gear 5.2.

[0026] Fig. Figure 4 shows a schematic representation of a method according to the invention in a fourth embodiment. The in Fig. The method shown in section 4 largely corresponds to that described in Fig. 3. The procedure shown, therefore, refers to the explanations regarding Fig. 3. Reference is made to avoid repetition. Unlike Fig. 3 includes the procedure in Fig. 4, however, additionally a switching process 9. This switching process monitors the value comparison 2 and the blocking process 3 as well as the value increase 4, which in Fig. 4 is represented by double-sided arrows. The switching process 9 is designed such that it can ensure that, instead of the second differential gear 5.2, the first differential gear 5.1 is selected as the differential gear to be locked as soon as the number of operating hours 7.2 of the second differential gear 5.2 becomes greater than the number of operating hours 7.1 of the first differential gear 5.1.

[0027] Fig. Figure 5 shows a schematic representation of a system 10 according to the invention. The system 10 according to the invention comprises a differential locking command generation module 11, a value increase module 12, a counting block for a first differential gear 13, a counting block for a second differential gear 14, a locking module 15, and a switching module 16. These modules and counting blocks, particularly in combination with some or all of the modules and / or counting blocks shown, are suitable for carrying out the methods according to the invention, in particular, for example, the methods described above.

[0028] Fig. Figure 6 shows a schematic representation of a vehicle 17 according to the invention. The vehicle 17 comprises a system 10 according to the invention, as shown by reference to the illustration. Fig.As already described in Section 5, the vehicle 17 further comprises a first axle 18.1, a second axle 18.2, and a third axle 18.3. The vehicle 17 is thus a so-called 6x4 vehicle, i.e., a vehicle with six wheels, four of which are driven. The first axle 18.1 and the second axle 18.2 are driven axles, whereas the third axle 18.3 is undriven. The first axle 18.1 comprises the first differential 5.1. The second axle 18.2 comprises the second differential 5.2. The system 10 is suitable for sending a first switching impulse 8.1 to the first differential 5.1 when the first differential 5.1 has been selected as the differential to be locked by a method according to the invention. Similarly, system 10 is suitable to send a second switching impulse 8.2 to the second differential gear 5.2 when the second differential gear 5.2 was selected as the differential gear to be switched.

[0029] The invention is not limited to the exemplary embodiments. The scope of protection is defined by the claims. Reference sign 1 Differential lock command 2. Value comparison 3 Blocking process 4. Increase in value 5.1, 5.2 first and second differential gear 6.1, 6.2 Number of respective actuations of the differential gears 7.1, 7.2 Number of respective operating hours of the differential gears 8.1, 8.2 Shift pulses for the differential gears 9 Switching process 10 System 11 Differential lock command generation module 12 Value Enhancement Module 13 Counting block for first differential gear 14 Counting block for second differential gear 15 Locking module 16 Switching module 17 vehicles 18.1, 18.2, 18.3 three axles of the vehicle

Claims

[1] Method for selecting a differential gear (5.1, 5.2) to be locked from a plurality of differential gears (5.1, 5.2) in a vehicle (17), characterized by , that when a differential locking command (1) is present, a value comparison (2) is automatically performed, wherein, within the scope of the value comparison (2), the respective stress values ​​(6.1, 6.2, 7.1, 7.2) of the majority of differential gears (5.1, 5.2) are compared with each other, and subsequently, from the majority of differential gears (5.1, 5.2), the differential gear (5.1, 5.2) with the lowest stress value (6.1, 6.2, 7.1, 7.2) is selected as the differential gear (5.1, 5.2) to be locked. [2] Method according to claim 1, characterized by , that the stress value (6.1, 6.2, 7.1, 7.2) includes a number of actuations (6.1, 6.2) of the respective differential gear (5.1, 5.2). [3] Method according to any one of the preceding claims, characterized by, that the stress value (6.1, 6.2, 7.1, 7.2) includes a number of operating hours (7.1, 7.2) of the respective differential gear (5.1, 5.2). [4] Method according to any one of the preceding claims, characterized by , that the method comprises a locking process (3) in which the differential gear (5.1, 5.2) to be locked is locked by being brought into a locking state, wherein, in the context of the locking process (3), an automatic increase (4) of the stress value (6.1, 6.2, 7.1, 7.2) of the differential gear (5.1, 5.2) to be locked is advantageously carried out after the differential gear (5.1, 5.2) to be locked has been locked. [5] Method according to claim 4, characterized by , that as part of the automatic value increase (4) the number of actuations (6.1, 6.2) of the differential gear to be locked (5.1, 5.2) is automatically increased, preferably by a value of «1». [6] Method according to any one of claims 4 to 5, characterized by , that as part of the automatic value increase (4) a duration of the locking state is determined, whereby the duration of the locking state is automatically added to the operating hours (6.1, 6.2) of the differential gear (5.1, 5.2) to be locked. [7] Method according to any one of the preceding claims, characterized by , that the method includes a switching process (9) in which a locking state of an initially locked differential gear (5.1, 5.2) is automatically terminated and an initially unlocked differential gear (5.1, 5.2) is newly selected as the differential gear (5.1, 5.2) to be locked when the number of operating hours (7.1, 7.2) of the initially locked differential gear (5.1, 5.2) exceeds the number of operating hours (7.1, 7.2) of the initially unlocked differential gear (5.1, 5.2). [8] Method according to one of the preceding claims, wherein, when the differential locking command (1) is present, a respective switching pulse (8.1, 8.2) is automatically output for each differential gear (5.1, 5.2) of the plurality of differential gears (5.1, 5.2), wherein, within the framework of the locking process (9), preferably only the differential gear (5.1, 5.2) to be locked receives its respective switching pulse (8.1, 8.2). [9] System (10) comprising means for at least partially carrying out a method according to any one of claims 1 to 8. [10] Vehicle (17) suitable for carrying out a method according to any one of claims 1 to 8 and / or comprising a system (10) according to claim 9. [11] Computer program comprising instructions which, when executed by a computer, cause the computer to execute the method according to any one of claims 1 to 8. [12] Computer-readable medium, characterized bythat the computer-readable medium comprises computer program code for carrying out a method according to any one of claims 1 to 8 and / or a computer program according to claim 11.

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