BR102016013118A2 - method and system for shifting gears into a vehicle gearbox - Google Patents

Abstract

The present invention relates to a method for changing the gear ratio on a gearbox (103) of a vehicle (100). gearbox (103) comprises a first gearbox unit (103a, 103b, 103c) and at least one second gearbox unit (103a, 103b, 103c) forming a combined gear ratio of said gearbox. exchange rate (103). the method includes, when changing the transmission ratio of said gearbox (103): - disconnecting said gearbox units (103a, 103b, 103c) from said gearbox (103) from said gearbox power source (101) and from said at least one driving wheel (113, 114); - when said gearbox unit gears (103a, 103b, 103c) are disconnected from said power source (101) and said at least one drive wheel (113, 114), changing the transmission ratio of at least one of said gearbox units (103a, 103b, 103c).

Description

"METHOD AND SYSTEM FOR CHANGING THE GEAR IN A VEHICLE EXCHANGE BOX" FIELD OF THE INVENTION

The present invention relates to vehicle gearboxes and, in particular, to a method and system for exchanging the gear ratio in a vehicle gearbox. The present invention also relates to a vehicle as well as a computer program and a computer program product implementing the method according to the invention.

BACKGROUND OF THE INVENTION

There are several types of vehicle transmissions. For example, a vehicle gearbox may be of a fully automatic type, where a vehicle control system completely controls gear shifting operations. The gearboxes used in these systems may consist of conventional automatic gearboxes, but often consist of an automated manual gearbox, where the vehicle control system automatically controls the gearshift in the gearbox.

In particular, for commercial vehicles, a larger number of gears than normally present in passenger cars is often required to provide a desired driveability. However, a passenger car type gearbox that provides a large number of gears would be relatively complex and spacious. Also, if gear shifting had to be done manually, the conventional Ή "type pattern would get a little more complicated.

Commercial vehicles that require a relatively large number of gears therefore often use a gearbox consisting of two or more gearbox units. A first gearbox unit may constitute a conventional main gearbox being controllable to a plurality of fixed gear ratios, for example on the order of 3-6 gears, and one or more additional gearbox units may be used. to provide additional shifting possibilities.

In this way, the number of gear ratios provided by the main gearbox can be multiplied by the number of gear ratios provided by the additional gearbox units.

[0005] For example, it is common to use a commonly denoted gear unit that can be configured with a low range transmission ratio and a high range transmission ratio. Each of the main gearbox gear ratios can be used at low range or high range, respectively, from the use of a gearbox, thus resulting in a gearbox providing twice the number of gear ratios. which is available through the main gearbox.

For example, if the main gearbox has three forward gears, the first through third gear will be accessed when the gear unit is set to low range. A range change to high range provides three additional gears, where the first gear of the main gearbox becomes fourth, the second gear becomes fifth, and so on.

The gearbox can also be supplied with a gearbox, which essentially divides each gear of the main gearbox into two. That is, the first gearbox of the vehicle corresponds to the first gearbox of the main gearbox / lower division, the second gear corresponds to the first gearbox of the main gearbox / upper gear, the third gear being the second gearbox main gearbox / lower division, the fourth gear being the second gear of the main gearbox / upper division, etc.

Consequently, if both a part of the reducing group and a part of the gearbox group are used, the initial three gears will be doubled by the gearbox group and the gearbox group, thus providing 12 gears in total.

Transmissions of the type where different gearbox units are used can be manufactured economically, and can also be made more compact compared to a single gearbox with a comparable number of gears. These advantages, however, come at the price of at least certain shifts that require simultaneous shifting of gear ratios in different gearbox units, thus making the shifting operation relatively complex and time consuming.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method and system for facilitating gearbox exchange of a gearbox in a vehicle. This objective is achieved by a method according to claim 1.

In accordance with the present invention, a gear ratio exchange method is provided in a gearbox of a vehicle, said gearbox being prepared to transfer torque between a power source and at least one drive wheel. of said vehicle. The gearbox comprises a first gearbox unit and at least one second gearbox unit, each of said first and second gearbox units being individually controllable in at least two gears having different gear ratios to form a combined transmission ratio of said gearbox. The method includes, when changing the transmission ratio of said gearbox: • disconnecting said gearbox units from said gearbox from said power source and from said at least one drive wheel ; and • when said gearbox unit gears are disconnected from said power source and said at least one drive wheel, changing the gear ratio of at least one of said gearbox units.

As mentioned above, gearboxes, in particular with respect to commercial vehicles, can be relatively complex in nature and comprise a plurality of gearbox units which are arranged sequentially, assembled as a single unit, to form a gearbox that is capable of displaying a relatively large number of gear ratios.

[0013] A gear ratio change in gearboxes of this type also requires that the transmission system be essentially relieved of torque when a gear shift occurs. Consequently, there is an interruption of torque transmission from the power source to the vehicle drive wheels when the transmission system is relieved of torque. Often the clutch is opened during a gear shift so that the power source is completely disconnected from the vehicle's drive wheels during gear shift operation.

This interruption in torque transmission is often highly undesirable, particularly when a heavily loaded vehicle is driven on an uphill stretch of road. An interruption in torque when climbing will result in an unwanted vehicle delay. Longer torque interruptions can also be viewed as negative from a driver's perspective for several reasons. For example, longer interruptions with associated delays may be uncomfortable for the driver. Also, a vehicle that exhibits longer interruptions in torque transmission may be perceived as a less powerful vehicle compared to vehicles that exhibit shorter interruptions in torque transmission.

It is therefore desirable that automatic gearbox shifts, which can be configured for a number of fixed gear ratios, can be performed with minimal interruptions in torque transmission from the power source to the drive wheels. of the vehicle.

In accordance with the present invention, the duration of torque interruptions during gear shifting can be reduced by a method in which the gearbox is disconnected from the power source, such as, for example, a motor combustion, and the driving wheels of the vehicle. At least in some situations, efficient gear shifting can be accomplished by disconnecting the gearbox and thus the gearbox units that make up the gearbox from the power source and drive wheels of the gearbox. vehicle. Since the gearbox, and thus the various gearbox unit gears, is disconnected from the power supply and the drive wheels, the rotary gearbox parts are allowed to rotate completely independently, for example from the rotation which, on the other hand, is caused by the driving wheels of the vehicle. This has the advantage that no speed synchronization, depending on the current driving conditions, such as the current vehicle speed, is required in the actual gear ratio shift. Instead, such synchronization may be prepared to be performed when gear ratios on one or more gearbox units have been made and the gearbox must be reconnected to the vehicle's drive wheels.

The gearbox may, for example, be disconnected from said at least one drive wheel by disconnecting said gearbox from a drive shaft of said vehicle.

In addition, according to one embodiment, the rotating parts such as axles, etc. may be subjected to a braking force applied by a transmission brake, for example an axle brake, to reduce the braking. rotational speed of rotating parts at a speed at which the gear ratio can be changed without the risk of wear due to a high speed gear error. A powerful axle brake can be used as all gear shifts are prepared to be performed at low rotational speeds, or at stop, of the gearbox's internal components due to the independence of power source speed and vehicle driving wheel speed.

The braking force may be applied before disconnecting any of the engaged gears of said gearbox units. This has the advantage that when the gears are still engaged, a braking force applied to one rotating member will automatically brake the other gearbox rotating members involved in torque transmission between the power source and the drive wheels.

The gearbox may advantageously be of a type wherein one of the gearbox units is a gearbox, arranged to provide high range and low range gear. In particular, the gearbox may be of a type comprising a planetary gear, and this may be the gearbox unit disposed closest to the drive wheels of the vehicle.

In particular, according to one embodiment, the planetary gear comprises a center wheel which is connected to an output shaft of said first gearbox unit, and a planetary holder that supports a plurality of planetary wheels that engage at said center wheel, wherein said planetary carrier is selectively connectable to an output shaft of said second gearbox unit. Since the output shaft is connected to the vehicle's drive wheels through, for example, a drive shaft, the planetary gear is connected to the drive wheels when connected to the output shaft. The planetary gear is disconnected from said at least one drive wheel by disconnecting said planetary carrier from said output shaft of said second gearbox unit.

For example, an axially displaceable coupling sleeve may be arranged in a first position to connect the planetary gear to the output shaft, and in a second position may be arranged to disconnect said planetary gear from the output shaft. and thus also of the driving wheels of the vehicle.

When the gear ratio has been changed in one or more of the gearbox units, the axles that transmit the torque through the gearbox are reconnected to the power source, and may be accelerated by the power supply. energy, for example by partially or fully closing the clutch. In this way, the rotational speed of the gearbox shafts can be synchronized, by conventional control of the speed of the power source, to the prevailing speed downstream of the gearbox, for example, a drive shaft speed, so that The gearbox can be connected to the drive wheels, for example by connecting to a drive shaft, without large shaft speed differences, thereby reducing the risk of excessive wear.

According to one embodiment, the axes that transmit the torque are accelerated at a speed such that a rotational speed difference in position to connect said gearbox to said at least one drive wheel is at most one. first speed difference.

Other features of the present invention and their advantages are set forth in the detailed description of exemplary embodiments set forth below and in the accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1A illustrates an exemplary vehicle transmission system in which the present invention may be advantageously used;

Fig. 1B illustrates an example of a control unit in a vehicle control system;

Fig. 2 illustrates an example of gearbox units of the gearbox of Fig. 1A.

Fig. 3 illustrates a gearbox unit of Fig. 2 in detail.

Fig. 4 illustrates an exemplary method according to one embodiment of the present invention.

Fig. 5 illustrates axle speeds in an exemplary gear shift operation in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF EXAMPLE

Fig. 1A schematically shows a transmission system of an exemplary vehicle 100. The transmission system comprises a power source in the present example of a combustion engine 101 which is conventionally connected via a combustion engine output shaft 101, usually through a flywheel 102, to a gearbox 103 through a clutch 106. A drive shaft 107 connects the gearbox 103 to the drive wheels 113, 114 via a transmission 108, such as a common differential, and drive shafts 104, 105 connected to said final transmission 108.

The combustion engine 101 is controlled by the vehicle control system via a control unit 115. The clutch 106 and gearbox 103 are also controlled by the vehicle control system via a control unit 116. .

As mentioned above, vehicles generally comprise a gearbox that can be configured for a number of gear ratios, where heavy / commercial vehicles generally comprise a gearbox comprising a plurality of gearbox units. individually controllable gearboxes to form a combined gearbox transmission ratio.

The present invention relates to gearboxes comprising at least two gearbox units, and an exemplary gearbox 103 comprising a plurality (in this example three) of gearbox units is disclosed in Fig. . 2.

Fig. 2 discloses combustion engine 101 and clutch 106. Fig. Further discloses gearbox 103, comprising three gearbox units 103A, 103B, 103C. The gearbox unit 103A is a conventional main gearbox that can be configured to three different forward gear ratios and one reverse gear. The figure further discloses a gearbox unit 103B which constitutes a range shift gearbox, or simply a range gearbox, disposed downstream of the main gearbox unit 103A. The range gearbox unit 103B is further discussed with reference to Fig. 3. The third gearbox unit 103C is located upstream of the main gearbox 103B in the direction of torque from combustion engine 101 to drive wheels 113, 114. The gearbox 103C is a gearbox that divides each gearbox of the main gearbox into two gear steps with different gear ratios to provide more gearbox ratios 103.

With respect to the main gearbox, a layshaft 202 comprises sprockets 203A, 204A, 205A which are rotatably fixed to the intermediate shaft 202 and each representing a gear ratio. For example, sprocket 203A represents first gear, sprocket 204A, second gear, and sprocket 205A, third gear. A mainshaft 206 comprises corresponding sprockets 203B, 204B, 205B which rotate freely relative to mainshaft 206, but which may be selectively locked for rotation with mainshaft 206 to engage a gear. For example, the first gear of the main gearbox may be engaged by operating a toothed clutch 207 arranged to rotate with the mainshaft 206 to a position where the sprocket 203B is engaged (i.e. left at Fig. 4, thereby rotating the sprocket 203B with the mainshaft 206 and thereby also engaging the idler shaft 202 with the mainshaft 206 through the sprocket 203A.

The second gear of the main gearbox can be engaged by disengaging tooth clutch 207 from sprocket 203B and instead of moving tooth clutch 208 to a position (at right in the figure) where, in instead, the sprocket 204B is engaged, thereby rotating the sprocket 204B with the mainshaft 206. Correspondingly, the third gear of the main gearbox can be engaged by operating the tooth clutch. 208 to a position (left) where instead the sprocket 205B is engaged, thereby defining the main gearbox for third gear. Each of the first through third gear is used for a plurality of the total number of gears provided by the gearbox as a whole. For example, the first gearshift first gear will be used for the first and second gearshift gears 103 (low and high split, low range) and also for the seventh and eighth gears (low and high split, high range) , in a manner well known to one of skill in the art.

In addition, in relation to the gearbox, the idler shaft 202 comprises an additional sprocket 209A which, similar to the above, is rotatably fixed to the idler shaft 202. An input shaft 201 comprises a corresponding sprocket 209B which it rotates freely relative to the input shaft 201, but can be selectively locked for rotation with the input shaft 201 via a coupling unit 210, for example a synchronization unit, in a manner known per se. It is also contemplated that unit 210 consists of or comprises a tooth clutch. The coupling unit 210 may further be used to connect the gearbox input shaft 201 to the sprocket 205B directly. The pair of sprockets 209A-B and the coupling unit 210 can thus be used to divide each gear of the main gearbox into two parts.

When, for example, the first gear is engaged, the coupling unit 210 is arranged to engage the sprocket 205B. This will result in the input shaft 201 being directly connected to the sprocket 205B, which, through the sprocket 205A, establishes a first gear ratio between the input shaft 201 and the intermediate shaft 202. The sprocket 205B, however , is not connected to mainshaft 206, but idler shaft 202 is connected to mainshaft 206 via sprocket pair 203A-B. Accordingly, the first gear is obtained by input shaft 201 -> sprocket 205B -> sprocket 205A -> idler shaft 202 -> sprocket 203A -> sprocket 203B -> mainshaft 206.

When the second gear is engaged (ie high division of the first gear of the main gearbox), the vehicle is instead driven with the pair of sprockets 209A-B engaged, resulting in a second gear ratio. between the input shaft and the idler shaft 202. The sprocket 203B is further engaged by the tooth clutch 207 as explained above, thereby extending the range of each gear.

This division can be performed for each gear where, when the coupling unit 210 engages the sprocket 205B and the tooth clutch 208 also engages the sprocket 205B, a 1: 1 gear ratio is achieved through gearbox units 103C, 103A. Finally, the gearbox 103B comprises a reverse gear, which is engaged by the pair of sprockets 212A-B through the tooth clutch 207 which is moved to the right in the figure, and where the main gear direction change 206 is performed via an idler sprocket 212C.

So far, gearbox units 103A, 103C have been described. It should be understood that Fig. 2 merely discloses an example of a design of such gearbox units, and that the present invention may be used for a number of different designs of such gearbox units. For example, the multiplying gear may be omitted. As explained below, the invention may be used for any gearbox comprising a plurality of gearbox units that can be disconnected from the vehicle's power source and drive wheels. However, the invention is perhaps particularly well suited for use in a system where a gearbox, for example comprising a planetary gear, is used and may be disconnected from the drive wheels of the vehicle.

The gearbox unit 103B is described with reference to Fig. 3.

Gearbox unit 103B is a gearbox unit of a type that is commonly referred to as gearbox. As mentioned above, the gearbox is used to double the number of gear ratios that are available by the main gearbox, and also, as in this case, the number of gears available by combining gearbox units 103A, 103C . Consequently, gearbox 103 in total provides 2 * 3 * 2 = 12 gear ratios.

The gearbox unit 103B, as shown in the figures, is arranged downstream of the main gearbox 103A as seen from the combustion engine 101, and comprises an input shaft 316 that may be formed by the mainshaft. 206 extending into gear unit 103B. The gearbox unit 103B is housed in a gearbox housing 312 that can be detached from the main gearbox housing 103A, although it is generally attached to the main gearbox housing.

Gearboxes of this type often comprise a planetary gear 314 having a low gear and a high gear whereby the gearshift possibilities of the main gearbox are divided into a set of low gears. range and in a range of high range gears. According to the disclosed example, there is a downshift through planetary gear 314 in low gear mode. In high gear mode, the transmission ratio is 1: 1 through planetary gear 314 according to the present example.

Planetary gear 314 comprises three main components which are rotatable with respect to each other. These components consist of a center wheel 318, which may be rotatably fixed to the input shaft 316, a planetary holder 320 that supports a plurality of planetary wheels 324 and a ring gear 322.

The planetary wheels are rotatably fixed to the planetary carrier 320, for example by means of bearings, and engage with the center wheel 318 in a manner known per se. Ring gear 322 in turn engages and mates with planetary wheels 324. Planetary carrier 320, as explained below, is arranged to be selectively engaged for rotation with an output shaft 328 which is fixedly secured. to the drive shaft 107 and thus to the drive wheels of the vehicle 113,114.

The gearbox unit 103B further comprises a first axially displaceable coupling sleeve 340 which is arranged to disconnect the input shaft 316 and thereby the center wheel 318 of the planetary holder 320 in a first (low) position. which, in a second position, is prepared to connect the input shaft 316 / center wheel 318 for rotation with the planetary holder 320. The connection / disconnection is accomplished by the selective coupling of the sleeve to coupling hubs or discs. 346, 348 which are rotatably attached to the center wheel / input shaft and planetary carrier respectively. The first coupling sleeve 340 is displaced by any suitable means, such as, for example, a pneumatic or hydraulic cylinder 364.

A second axially displaceable coupling sleeve 342 in a first position is arranged to lock the ring gear 322 into the gearbox housing 312, the ring gear 322 thereby held stationary. In a second position of the second coupling sleeve 342, the ring gear 322 is allowed to rotate freely with respect to the gearbox housing 312. The second coupling sleeve 342 is displaced, for example, by a pneumatic or hydraulic cylinder 366.

Finally, a third axially displaceable coupling sleeve 343 is arranged to selectively connect the planetary carrier 320 to the output shaft 328. That is, in a first position, shown in Fig. 3, coupling sleeve 343 locks the planetary carrier 320 for rotation with the output shaft 328, and thus the drive shaft 107 and the drive wheels of the vehicle 113, 114, via hub or coupling disc 353 which is locked for rotation with the output shaft 328. In the second position, coupling sleeve 343 disconnects the planetary carrier 320 from the output shaft 328 so that the planetary gear can rotate completely independent of the rotation of the drive shaft 107 and vehicle drive wheels 113, 114. The third coupling sleeve is displaced, for example, by a pneumatic or hydraulic cylinder 367.

The low range mode is achieved by positioning the first coupling sleeve 340 to disconnect the planetary carrier 320 from the input shaft 316 and positioning the second coupling sleeve 342 such that the ring gear 322 is locked in place. rotationally in the gearbox housing 312, while the third coupling sleeve locks the planetary carrier to the output shaft.

In high range mode, which is shown in Fig. 3, the first coupling sleeve 340 is positioned to connect the input shaft 316 to the planetary holder 320. The second coupling sleeve 342 is still positioned to the position. disconnect the ring gear from the gearbox housing. Torque transfer from input shaft to output shaft in high range mode is accomplished via input shaft 316, planetary carrier 320 and output shaft 328 via third coupling sleeve , the gear ratio through planetary gear 314 is thus 1: 1.

The planetary gear 314 disclosed in Fig. 3 is exemplified from a functional point of view and does not disclose specific constructional characteristics. The planetary gear is, however, fully described in Swedish patent application SE1450626, which is incorporated herein in its entirety. For this reason, reference is made to application SE1450626 in relation to the specific advantages and features of this gearbox, and in the functionality of the present application, it is only described to the extent that explanation of the invention is required. Further details are disclosed in the said application.

Unlike the referenced order, the third coupling sleeve is, according to the present example, used to disconnect the planetary gear from the output shaft. In the referenced order, instead, the third coupling sleeve is arranged to connect the ring gear to the output shaft instead of disconnecting the planetary gear from the output shaft. In this way a reverse gear is achieved by the planetary gear. This is fully described in the referenced request.

It is also contemplated that the third coupling sleeve may be configured to three different positions to also provide reverse gear. Alternatively, it is contemplated that an additional coupling sleeve is used. Solutions where the planetary gear is prepared to be disconnected from the vehicle's drive wheels are described in parallel order SE1550665. This request is also incorporated in this document in its entirety.

Through the possibility of disconnecting the planetary gear from the output shaft, the present invention provides a method that allows rapid gear changes with minimal wear. An exemplary method 400 of the present invention is shown in Fig. 4, where the method may be implemented at least partially, for example, in the control unit 116 for controlling the operation of the clutch 106 and gearbox 103. The functions of a Vehicle control systems are generally controlled by a series of control units, and vehicle control systems of the disclosed type generally comprise a communication bus system consisting of one or more communication buses for connecting a series of electronic control units. (ECUs), or controllers, to various components on board the vehicle. This control system can comprise a large number of control units, and control of a specific function can be divided between two or more of them.

For the sake of simplicity, Fig. 1A depicts only control units 115-116, but vehicles 100 of the type illustrated are generally provided with significantly more control units, as one skilled in the art will appreciate. Control units 115-116 are arranged to communicate with each other and with various components through said communication bus system and other wires, partially indicated by the interconnecting lines in Fig. 1A.

The present invention may be implemented in any suitable control unit in vehicle 100 and therefore not necessarily in control unit 116. Control of a gear shift according to the present invention will generally depend on signals which are received from vehicle control units and / or components, and this is generally the case where control units of the disclosed type are normally adapted to receive sensor signals from various parts of vehicle 100. control 116 may, for example, receive signals from, for example, the motor control unit 115 or any other control unit where a gear shift is to be performed. The control unit 116 may further be prepared to receive signals from various sensors with respect to gearbox control, for example signals indicating coupling sleeve positions, tooth clutches, etc. Control units of the type illustrated are also generally adapted to distribute control signals to various vehicle parts and components, for example to coupling sleeve actuators, gear clutches, etc., and / or, for example, to control unit 115 to request specific engine control before, during and / or after a gear shift. This is all known to one of skill in the art.

Control of this type is often performed by programmed instructions. Programmed instructions typically consist of a computer program that, when executed on a computer or control unit, causes the computer / control unit to exercise the desired control, such as the method steps according to the present invention. . The computer program generally constitutes a part of a computer program product, wherein said computer program product comprises a suitable storage medium 121 (see Fig. 1B) with the computer program 126 stored in said computer medium. storage 121. The computer program may be stored non-volatile in said storage medium. Digital storage medium 121 may, for example, consist of any of the group comprising: ROM (Read Only Memory), PROM (Programmable Read Only Memory), EPROM (Erasable PROM), Flash Memory, EEPROM (Electrically PROM) Erasable), a hard disk drive, etc., and may be arranged on or in connection with the control unit when the computer program is then executed by the control unit. The behavior of the vehicle in a specific situation can thus be adapted by modifying the instructions of the computer program.

An exemplary control unit (control unit 116) is shown schematically in Fig. 1B, wherein the control unit may comprise a processing unit 120, which may consist of, for example, any suitable type of processor. or microcomputer, such as a circuit for digital signal processing (Digital Signal Processor, DSP) or a circuit with a predetermined specific function (Application Specific Integrated Circuit, ASIC). Processing unit 120 is connected to a memory unit 121, which provides processing unit 120, with, for example, stored program code 126 and / or stored data that processing unit 120 requires to be capable of processing. perform the calculations. Processing unit 120 is also arranged to store the partial or final results of the calculations in memory unit 121.

In addition, the control unit 116 is equipped with devices 122, 123, 124, 125 for receiving and transmitting the input and output signals respectively. Such input and output signals may comprise waveforms, pulses, or other attributes that input signal receiving devices 122, 125 detect as information for processing by processing unit 120. Signal transmission devices 123, 124 The output signals are prepared to convert the results of the processing unit 120 calculation into output signals for transfer to other parts of the vehicle control system and / or component (s) to the component (s). which signal (s) are intended. Each and every connection to devices for receiving and transmitting their input and output signals may consist of one or more of one cable; a data bus, such as a Controller Area Network (CAN) bus, a MOST (Orientated Media Systems Transport) bus, or any other bus configuration, or a wireless connection.

Returning to the exemplary method 400 illustrated in Fig. 4, the method begins at step 401, where it is determined whether a gear shift should be performed. This gear shift may be arranged to be performed, for example, by changing the gear ratio of one or more of the main gearbox 103A, gearbox 103B and gearbox 103C. Accordingly, this may, according to one embodiment, be determined at step 401 if no gear shifting is to be performed. The method remains at step 401 until this is no longer the case. The method continues at step 402 when it is determined that a gear shift according to the invention is to be performed.

The transition from step 401 to step 402 may also, for example, be initiated only according to various criteria and not every time for any gear shifting. For example, the control according to the invention may be arranged to be performed, for example, only when specific gear shifts have to be performed, such as when a gear ratio change has to be performed on gearbox 103B, or gearbox 103B and main gearbox 103A. Other suitable criteria for the transition from step 401 to step 402 may also apply. Determining whether a gear shift should be performed can be done in any suitable and conventional manner and is not part of the present invention.

According to the present example, the gearbox is shifted from sixth gear to seventh gear. Sixth gear, in this example, corresponds to the main gearbox 103A being set to the third position (205B sprocket engaged), the gearshift group 103C being set high (ie, engaging the sprocket 209B) and gearbox 103B being set to low range. When shifting to seventh gear, main gearbox 103A is shifted from third position to first position, gearbox 103B is shifted from low range to high range, and the gearbox from top to bottom. Accordingly, the present example involves gear shifting in all three gearbox units 103A-C. Shifting will also be illustrated with reference to Fig. 5, which discloses the corresponding speeds of the gearbox input shaft 201, intermediate shaft 202, and mainshaft 206. At time T0, vehicle 100 is driven to a gearbox input shaft speed, solid line 501, approximately 1500 RPM. When the clutch 106 is closed, the gearbox input shaft speed 201 corresponds to the combustion engine speed 101 and, consequently, the combustion engine speed is also approximately 1500 RPM before shifting.

The main shaft of the gearbox 206, connected to the input shaft 201 through the sprockets 209A-B and the sprockets 205A-B, rotates at a faster speed than the input shaft of the gearbox 201, dashed / dotted line 503. In addition, intermediate shaft 202, dashed line 502, rotates at a speed in the order of the input axis speed. At time T1, a gear shift is initiated according to step 401, and the method continues at step 402.

In step 402, a reduction in the torque that is transmitted through the gearbox 103 is initiated. That is, the torque produced by combustion engine 101 is reduced to alleviate the torque transmission drive system. When the torque has been reduced to a desired degree, the clutch 106 is opened at step 403. As is well known to one skilled in the art, reduction of the torque transmitted through the gearbox 103 can be partially accomplished by reducing the transmissible torque using The clutch 106 and, consequently, the opening of the clutch may be arranged to be realized at least partially simultaneously with the reduction in torque that is produced by the combustion engine. Torque reduction can be performed in any suitable manner.

In addition, when the torque that is transmitted through the gearbox 103 has been reduced to a desired degree and the clutch has been opened, planetary gear 314 is disconnected, step 404, from the vehicle's drive wheels, maneuvering the third coupling sleeve 343 to the position where planetary holder 320 is no longer connected to output shaft 328.

Referring to Fig. 5, this corresponds to the time T2. Consequently, at time T2, the gearbox is disconnected from the combustion engine 101 as well as from the drive wheels of the vehicle 113, 114. This means that any rotating parts of the gearbox units 103A-C rotate completely independent of the gear speed. combustion engine and the rotational speed of the drive shaft (sprocket). All 103A-C gearbox units are still engaged as before shifting. That is, the input shaft 201 is still rotatably locked to the planetary carrier by means of sprockets 209A-B, the third gearbox gearbox, the center wheel and the planetary wheels.

In step 405, one or more axle brakes, acting on any suitable axle or axes, are / are activated. Since the gearbox is still running, for example, any of the gearbox input shaft 201, idler shaft 202, mainshaft 206, center wheel 318, planetary holder, etc. can be submitted. a braking action that will simultaneously brake all rotating parts that are operating in the current gear. According to the invention, a powerful brake may be used which is capable of reducing axle speeds to zero and / or a low rotational speed in a short period of time. This is because, unlike state of the art solutions, gearbox speeds do not need to be synchronized with rotary output shafts when shifting gears once gearbox 103 has been disconnected at both ends.

According to the present invention, therefore, the speeds of the rotating parts are braked at zero speed, or substantially zero, or at least at a speed that is less than a first speed, speedjim, which may be prepared to depend on. of the specific axis to which it is defined. If, for example, the gearbox has to be changed, the first speedjim speed will be adapted and applied to the mainshaft. In particular, the first speedjim speed is chosen so that the tooth clutch and coupling gloves can be maneuvered without being subjected to excessive wear.

Accordingly, according to the invention, the speeds of the gearbox rotating parts are reduced at speeds so low that essentially no moment of inertia remains in the gearbox, and shifts can thus be performed. smoothly and without the risk of unwanted gear error. By way of example, the first speed, speedjim, may be 100 rpm or preferably 50 rpm.

According to the present example, braking is performed by an intermediate shaft brake 211, and in step 406, it is determined whether the rotational speed of the gearbox rotating parts has been reduced at least to the first speedjim speed. Braking is continued through step 405 until this is no longer the case. When the first speedjim speed has been reached, time T3 in Fig. 5, the method will continue at step 407 where the gears are shifted when the gearbox components are non-rotating or rotating at low speeds. That is, according to the present example, the toothed clutch 208 disengages the gearwheel 205B (third gearshift of the main gearbox) while instead the toothed clutch 207 engages the gearwheel 203B (first gearshift) exchange rate). In addition, the coupling unit 210 disengages the sprocket 209B and engages the sprocket 205B to exchange the top-down gearbox. In addition, the first coupling sleeve 340 is maneuvered to engage the planetary carrier with the center wheel / input shaft 316 to shift the gearbox to high range, and the second coupling sleeve 342 is moved into position to disconnect the gearbox. ring gear of gearbox housing. That is, the first and second coupling sleeves are shifted to be positioned as shown in Fig. 3.

At step 408, it is determined whether all required changes have been made, which, for example, can be determined by means of position sensors such as, for example, inductive sensors, tooth clutches and coupling gloves. , or by any other suitable means for determining the position of gearbox elements. The method remains at step 408 until this is no longer the case. When all gear ratios have been changed, and the gearbox 103 has thus been set to seventh gear, a clutch lock 106 is initiated, step 409. When the clutch engages, time T4 in Fig. 5, the input shaft 201 will accelerate, and once all gears are engaged, the intermediate shaft 202, mainshaft 206, planetary carrier, etc., will also be accelerated. This is illustrated between ο T4 and ο T5 in Fig. 5.

Preferably, the speed of the combustion engine 106 is controlled in the time period starting at time T2 for the target speed in the new gear, which in this example is 1180 RPM, so that when the clutch 106 has If it has been closed to a position where it no longer slides, time T5, the planetary carrier 320 will rotate at a speed substantially corresponding to the rotational speed of the output shaft 328. In step 410, it is determined whether the output shaft 328 can be engaged by example, determining whether the speed difference between the planetary carrier and the output shaft 328 is within any suitable speed difference, Δη, within which the third coupling sleeve 343 can be safely operated without the risk of excessive wear on the components. The speed difference, Δη, may in some modalities be 50 rpm. The method may remain at step 410 until this is no longer the case, where, for example, proper combustion engine speed control may be performed / required as required.

When it is determined that the output shaft can be engaged, this is accomplished in step 411, by engaging the coupling sleeve 343 to engage the position, thereby closing the transmission system so that torque can be again be transmitted from the power source to the drive wheels. The torque is then increased to a desired level in a conventional manner, step 412, and the method may return to step 401, waiting for a next gear shift. The invention has been described in Fig. 5 for shifting to a larger gear (although, as disclosed, there may actually be shifts to smaller gears in the individual gearbox units). However, the invention is equally applicable for any type of gear shifting, for example also shifting from larger gears to smaller gears. However, the invention is particularly suited for changing the range in the gearbox.

The present invention therefore provides a solution where shifting can be performed with gearbox components that are stationary, or rotating at low speed, and regardless of the rotational speeds of the power source and drive wheels. That is, no synchronization is required during actual maneuvering of gearbox components such as tooth clutches, coupling sleeves and the like. This has the advantage that, for example, powerful axle brakes can be used as long as no precise control of axle speeds is required. This in turn allows for faster gear changes.

Furthermore, a solution according to the invention reduces the risk of unwanted oscillations in planetary gear shifts which may otherwise be caused by reaction torques arising from, for example, planetary wheel bearings. when the planetary wheels are accelerated and the planetary holder is connected to the output shaft, as in the state of the art.

Finally, the present invention has been exemplified for a specific gearbox type, where the drive shaft disconnection is performed in a specific manner. However, the invention is applicable to any type of gearbox, in particular any type of gearboxes, which can be simultaneously disconnected from the vehicle's drive wheels and the vehicle's power source.

Claims (17)

1. Method for exchanging the gear ratio on a gearbox (103) of a vehicle (100), said gearbox (103) being arranged to transfer torque between a power source (101) and at least one driving wheel (113, 114) of said vehicle (100), said gearbox (103) comprising a first gearbox unit (103A, 103B, 103C) and at least a second gearbox unit (103A, 103B, 103C), each of said first and second gearbox units being individually controllable in at least two gears having different gear ratios to form a combined gear ratio of said gearbox (103), characterized in that which, when changing the gear ratio of said gearbox (103): • disconnects said gearbox units (103A, 103B, 103C) from said gearbox (103) from said power source (101) ) and at least one driving wheel (113, 114); and when said gearbox unit (103A, 103B, 103C) gears are disconnected from said power source (101) and said at least one drive wheel (113, 114), the transmission ratio of the hair changes. least one of said gearbox units (103A, 103B, 103C). Method according to claim 1, characterized in that it comprises, when said gearbox units (103A, 103B, 103C) are disconnected from said power source (101) and said drive wheels (113 114): • apply a braking force to a rotary member of any of said gearbox units (103A, 103B, 103C) in order to reduce the rotational speed of the rotary members of said gearbox (103) and • when the rotational speed of said rotating member has been reduced to at least one first speed (speedjim), change the gear ratio of at least one of said gearbox units (103A, 103B, 103C). A method according to claim 2, further comprising: reducing the rotational speed of said rotating member substantially to zero. A method according to either claim 2 or claim 3 further comprising: applying said braking force before disconnecting at least one of the engaged gears of said gearbox units (103A, 103B .103C). A method according to any one of claims 1 to 4, characterized in that said second gearbox unit (103B) is a gearbox designed to provide high range and low range range. . A method according to claim 5, characterized in that said second gearbox unit (103B) comprises a planetary gear, the method further comprising: disconnecting said planetary gear from said at least one drive wheel (113, 114). Method according to claim 6, characterized in that said planetary gear comprising a center wheel (318) is connected to an output shaft of said first gearbox unit (103A), and a gear carrier. (320) supporting a plurality of planetary wheels (324) which engage said center wheel (318), said planetary holder (320) is selectively connectable to an output shaft (328) of said second gearbox unit (103B), and, disconnecting said planetary gear from said at least one drive wheel (113, 114) by disconnecting said planetary carrier (320) from said output shaft (328) from said second gearbox unit (103B). Method according to either of claims 6 or 7, characterized in that an axially displaceable coupling sleeve (343) in a first position is arranged to connect said planetary gear to said at least one drive wheel (113, 114) of said vehicle (100), and, in a second position, is arranged to disconnect said planetary gear from at least one drive wheel (113, 114) of said vehicle (100). A method according to any one of claims 1 to 8, characterized in that said gearbox (103) comprises said first (103A), said second (103B) and a third (103C) drive unit. gearbox which is controllable in at least two gears having different gear ratios, the method further comprising, when said gearbox units are disconnected from said power source (101) and said at least one drive wheel (113). 114): • exchange the transmission ratio of at least one of said first, second and third gearbox units. Method according to claim 9, characterized in that it further comprises: • exchanging the transmission ratio of at least two of said first, second and third gearbox units. Method according to any one of claims 1 to 10, characterized in that it comprises, after said transmission ratio changeover of said at least one of said gearbox units (103A, 103B, 103C): By said power source (101) accelerating the axes that transmit torque of said gearbox units before connecting said gearbox (103) to said at least one drive wheel (113, 114). The method of claim 11 further comprising: accelerating said torque transmitting axes such that a rotational speed difference in a position for connecting said gearbox downstream of the said engaged gears, said at least one drive wheel (113, 114) is at most a first speed difference (Δη). Method according to any one of claims 1 to 12, characterized in that it comprises: • connecting said gearbox (103) to said at least one drive wheel by connecting said gearbox (103) to a drive shaft (107) of said vehicle. Computer program characterized in that it comprises a program code which, when said program code is executed on a computer, causes said computer to perform the method as defined in any one of claims 1 to 13. . A computer program product comprising a computer readable medium and a computer program according to claim 14, wherein said computer program is contained in said computer readable medium. 16. A system for exchanging the gear ratio on a gearbox (103) of a vehicle (100), said gearbox (103) being arranged to transfer power between a power source (101) and at least one wheel. (113, 114) of said vehicle (100), said gearbox (103) comprising a first gearbox unit (103A, 103B, 103C) and at least a second gearbox unit (103A, 103B 103C), each of said first and second gearbox units being individually controllable in at least two gears having different gear ratios to form a combined gear ratio of said gearbox (103), the system characterized by the fact that that: • is for disconnecting said gearbox units (103A, 103B, 103C) from said gearbox (103) from said power source (101) and said at least one drive wheel ( 113, 114); • for when said gearbox unit (103A, 103B, 103C) gears are disconnected from said power source (101) and said at least one drive wheel (113, 114) at least one of said gearbox units (103A, 103B, 103C). Vehicle, characterized in that it comprises a system for changing the gear ratio in a gearbox as defined in claim 16.