SE538357C2 - Styrning av sidoaxelbroms - Google Patents

Abstract

538 357 SUMMARY Method (300) and control unit (115) for controlling an AMT gearbox (113) in a vehicle (100) to avoid overheating of a side axle brake (250) in the gearbox (113). The method (300) comprises detecting (301) a gearing gear; calculating (302) a speed change on a side shaft (230) in the gearbox (113), to synchronize the speed on the side shaft (230) with the speed on the main shaft (112) as a result of the requested upshift; forecasting (303) of heat energy generated in the side axle brake (250) when braking the side axle (230), based on the calculated (302) speed change; and starting (304) an actuator to reduce the heat energy generated in the side axle brake (250) in connection with shifting according to the detected (301) upshift request, when the predicted (303) heat energy exceeds a spruce value.

Description

TECHNICAL FIELD CONTROL OF SIDE AXLE BRAKE This document describes a procedure in a control unit in a vehicle and a control unit in the vehicle. More specifically, control of a side axle brake in an Automated Manual Transmission (AMT) gearbox in a vehicle with a side axle brake is described, where the energy development in the friction lining of the side axle brake is reduced, as overheating of these is risked.

BACKGROUND A commonly used type of gearbox in heavy vehicles is a so-called AMT gearbox.

In this context, vehicles refer to, for example, lorries, lorries, flatbed trucks, transport vehicles, wheel loaders, buses, off-road vehicles, tracked vehicles, tanks, quad bikes, passenger cars or other similar motor-driven manned or unmanned means of transport, adapted for land-based geographical transport.

Such an AMT gearbox generally consists of a concentric input shaft, a main shaft and an output shaft and at least one parallel side shaft. On these shafts are a number of pairs of gears which are in constant engagement with each other. The side axle gears are rotationally locked to the side axle while the gears of the other axles are mounted in bearings. In order for a pair of gears to be able to transmit torque, the stored gear in that pair is locked against its shaft. Torque is transmitted from the power source via the clutch and input shaft, over connected split stage alternating gear to the side shaft, over a connected main gearbox to the main shaft and further to the PTO shaft, possibly also via a range gear _ Because the other toothed gear gears differ from the active gear pair, the rotational speed of the stored gears differs from that of the main shaft.

In order to engage another pair of gears, ie to change gears, in a comfortable way and without the risk of damage to the clutch geometries, the rotational speed differences between the main shaft and the gear to be engaged should be synchronized. This can be done in different ways, for example with synchronization units for each gear. One trend in the industry is to replace the synchronization units with a common side-axle brake for upshifts and use the vehicle's power source (engine) for downshifts. This is because the synchronization units are expensive to manufacture.

A side axle brake can be used when shifting to brake the side axle and the input shaft, this to make fast and comfortable shifts. Industry standard is to use a side axle brake with a fixed braking torque. Side axle brakes are usually pneumatically operated. In order to give the correct speed in the gearbox for engaging the next gear, it is therefore important to switch off the side axle brake at the right time, and that the time it takes for the brake side axle to the desired speed does not vary with temperature development too much, ie the friction speed does not vary too much with temperature development due to the friction that has arisen.

When the gearbox synchronizing units, one per gear, are replaced with a central side axle brake, the number of cycles of the friction lining used to synchronize the gearbox will increase. The number of times when the same friction lining is used repeatedly without having sufficient cooling time between the heat-generating braking times will also increase. Both problems will lead to increased wear and thus shorter life of the friction lining.

With certain types of friction coatings, the friction number is linked to the temperature. It is common for the friction rate to decrease with increasing temperature. Braked rotational energy leads to elevated temperature in the friction lining. A lower friction number gives a lower braking torque, which leads to a longer shift time.

Furthermore, an increased frictional energy in the lining during repeated braking with the side axle brake can cause oil to burn into the friction lining, which results in impaired braking ability. This also means that the time period for shifting is extended, as it takes longer to synchronize the speeds.

The vehicle's driveline is in a torqueless state during shifting. The vehicle is thus not driven forward by the engine during the period of time that the shift is completed, but rolls further in the direction of travel due to its inertia.

An extended shift time can therefore be difficult for the vehicle and its driver, perhaps especially when shifting in slightly more difficult conditions, such as when transporting in a bumpy uphill slope at low speed and with a heavy load. As the engine lacks traction in the direction of travel during the shifting process, the vehicle therefore loses speed quickly due to the combination of uphill and heavy loads.

This can be a particular problem when driving in, for example, a mine, where there is often a heavy load and uphill in combination with substandard roads that limit speed. If the gearbox tries to shift up but is delayed due to overheated friction pads in the side axle brake, the new, higher gear may have a too low speed after shifting due to the reduced vehicle speed, which in turn causes the engine to generate such a torque that the vehicle does not have the strength and thus the engine stops. Alternatively, the gearbox can counteract this shortly afterwards, which leads to a further torque-free condition and thus a further reduced vehicle speed, etc.

Another problem from a manufacturer's perspective is to dimension the side axle brake and associated friction lining for manufactured vehicles, as the shift intensity and thus the load on friction lining varies greatly between different vehicles, depending on the type and area of use but also driving style. A long-distance truck can travel long distances at constant speeds and make changes, while a truck in mining in a hilly open pit, a garbage truck or a distribution truck in an urban environment may have a very change-intensive existence. If friction pads are dimensioned according to the toughest conceivable conditions that the gearbox and the side axle brake can be exposed to, this becomes costly and entails an unnecessary waste of resources as the majority of gearboxes are not exposed to such extreme stress. If, on the other hand, dimensioning of friction pads is made with respect to the load of the average vehicle, the above-described disadvantages of undersized pads will occur on vehicles which are exposed to harsh gear conditions. Having different dimensioned friction linings in different vehicles, depending on the forecast load, can also be difficult, as the manufacturer does not always know in advance how the user / buyer intends to use his vehicle. Furthermore, the area of application for a particular vehicle may vary during the life of the vehicle.

It can be stated that much remains to be done to improve the shifting of a vehicle with an AMT gearbox, especially for vehicles driving in difficult and / or unpredictable driving conditions.

SUMMARY It is therefore an object of this invention to be able to solve at least some of the above stated problems and to improve the procedure when shifting in a vehicle with AMT gearbox in order to avoid overheating of a side axle brake in the gearbox.

According to a first aspect of the invention, this object is achieved by a method in a single control unit for controlling a gearbox in a vehicle. The gearbox is of the AMT gearbox type. The procedure is intended to avoid overheating of a side axle brake in the gearbox. This method includes detecting a gear up request, as well as a calculation of a speed change on a side axle in the gearbox, to synchronize the speed on the side axle with the speed on the main axle due to the requested upshift. Furthermore, the method comprises forecasting heat energy that develops in the side axle brake when braking the side axle, based on the calculated speed change. In addition, the method comprises initiating a measure to reduce the heat energy generated in the side axle brake in connection with shifting according to the detected gear up request, when the predicted heat energy exceeds a limit value.

According to a second aspect of the invention, this object is achieved by a control unit arranged to steer an AMT gearbox in a vehicle in order to avoid overheating of a side axle brake in the gearbox. The control unit comprises a processor circuit, which is arranged to detect an upshift request. Furthermore, the processor circuit is also arranged to calculate a single-speed change on a side axle in the gearbox, in order to synchronize the speed on the side axle with the speed on the main shaft as a result of the requested upshift. The processor circuit is also arranged to forecast heat energy which develops in the side-axle brake during braking of the side-axle, based on the calculated change in speed. Furthermore, the processor circuit is also arranged to initiate a measure to reduce the heat energy which is developed in the side shaft brake in connection with shifting according to the detected gear up request, when the predicted heat energy exceeds a limit value.

By forecasting when the friction energy developed in a friction lining in the side axle electric brake becomes so high that the friction lining risks getting such a high temperature that the friction figure drops, which gives poorer braking effect and thus longer shift time, a friction energy inhibiting measure can be performed as reduces the frictional energy that would otherwise be developed in the friction lining. Thereby, the risk of overheating of the friction lining on the side axle brake can be reduced, which leads to an increased service life of the friction lining. Since the temperature of the friction pad can be kept below a certain limit value, it is ensured that the pad has the desired friction number and thus maximum braking performance when needed, which gives a short changeover time and thus a shorter time in torque-free condition in the driveline. This improves the shifting performance of the gearbox and the vehicle. Another advantage that the above measures entail is that oxidation of the gearbox oil is reduced when the temperature of the oil is kept down.

Other advantages and additional new features will become apparent from the following detailed description.

FIGURES OF FIGURES Embodiments of the invention will now be described in further detail with reference to the accompanying figures, which illustrate various embodiments: Figure 1A illustrates a scenario with a vehicle according to an embodiment.

Figure 1B illustrates an example of a vehicle according to an embodiment.

Figure 2 illustrates a gearbox with side axle brake according to an embodiment. Figure 3 is a flow chart illustrating an embodiment of the invention. Figure 4 is an illustration of a control unit according to an embodiment of the invention.

DETAILED DESCRIPTION Embodiments of the invention comprise a method and a control unit, which can be realized according to any of the examples described below. However, this invention may be practiced in many different forms and should not be construed as limited by the embodiments described herein, which are intended to illustrate and illustrate various aspects.

Additional aspects and features of the invention may become apparent from the following detailed description when considered in conjunction with the accompanying figures. However, the figures are to be considered only as examples of different embodiments of the invention and should not be construed as limiting the invention, which is limited only by the appended claims. Furthermore, the figures are not necessarily to scale, and are, unless otherwise specifically indicated, intended to conceptually illustrate aspects of the invention.

Figure 1A shows a vehicle 100, adapted for shifting and motor-driven driving in, inter alia, a first direction of travel 105. For example, but not necessarily, the vehicle 100 may be an accelerating truck, a distribution truck in an urban environment, a garbage truck, a bus instead of traffic, a truck used in mining , or a timber truck on a forest road, to name just a few examples.

Figure 1B schematically shows a driveline in the vehicle 100 according to an embodiment of the present invention. The driveline comprises an internal combustion engine 110, which is connected via an shaft outgoing on the internal combustion engine 110, for example via a flywheel, to an input shaft 112 of a gearbox 113 via a clutch 114. A sensor 111 may be specially arranged to read the speed of the internal combustion engine. on the shaft 112. Such a sensor 111 can also be called a speedometer. The gearbox 113 consists of an automated manual gearbox, commonly referred to as the AMT gearbox. All references in this description to “gearbox”, or “vehicle gearbox” refer to such an AMT gearbox.

The coupling 114 may, for example, consist of an automatically controlled coupling which may be, for example, of the dry lamella type. The engagement of the friction element (lamella) with the flywheel on the output shaft of the motor can be controlled by means of a pressure plate, which can be displaceable longitudinally by means of, for example, a lever, the function of which can be controlled by a clutch actuator. The influence of the clutch actuator on the lever is in turn controlled by the vehicle's clutch control system via a control unit 115. The control unit 115 also controls the gearbox 113 and the gear unit this by means of a control algorithm. The control algorithm that controls the vehicle's gearbox 113 is affected by one or more parameters, which may be driver-dependent, indirect driver-dependent or driver-independent, such as vehicle inclination, vehicle weight, vehicle type, ride comfort, accelerator pedal position, accelerator pedal position change speed, engine speed or vehicle speed ; to name just a few, according to various embodiments. One or more such parameters thus control the gear selection in the AMT gearbox 113. When the control unit 115, for example, reads the current speed via the sensor 111 and finds that the reading speed exceeds a determined gear point for a higher gear, a gear request can be generated by the control unit 115 and sent to the AMT gearbox 113 to load the higher gear.

The vehicle 100 also includes drive shafts 116, 117, which are connected to the vehicle's drive wheels 118, 119, and which are driven by a shaft 120 emanating from the gearbox 113 via a shaft gear 121, such as, for example, a differential gear. The vehicle 100 schematically shown in Figure 1B comprises only two drive wheels 118, 119, but embodiments of the invention are also applicable to vehicles with a plurality of drive axles provided with one or a plurality of drive wheels.

Adjacent to the gearbox 113, or rather the side shaft 230 of the gearbox, a side shaft brake 250 is connected, which is controlled by the control unit 115. The side shaft brake 250 comprises at least one friction lining, which can be applied to the side shaft 230 when the speed of the side shaft 230 is reduced. the speed. The friction lining then forms the friction surface between the side axle 230 and the side axle brake 250.

The control unit 115 may in certain embodiments communicate with other units in the vehicle100 through a control system, which may consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECUs), or control units / controllers, and various the vehicle 100 localized components. Such a control system may comprise a large number of control units, and the responsibility for a specific function may be divided into more than one control unit. Likewise, a control unit can be arranged to be responsible for several functions.

The control unit 115 is thereby arranged to partly communicate with other units, partly arranged to receive signals and measured values and possibly also trigger a measurement, for example with a certain time interval. Furthermore, the control unit 115 is arranged to communicate, for example, via the vehicle's communication bus, which may consist of one or more of single cables; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems Transport), or any other bus configuration.

The control unit 115 may also, or alternatively, be arranged for wireless communication over a wireless interface according to certain embodiments. The wireless interface can be radio transmitters based on wireless communication technology such as 3rd Generation Partner-ship Project (3GPP) Long Term Evolution (LTE), LTE-Advanced, Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Universal Mobile Telecommunications System ( UMTS), Global System for Mobile Communications / Enhanced Data rate for GSM Evolution (GSM / EDGE), Wideband Code Division Multiple Access (WCDMA), World-Wide lnte-roperability for Microwave Access (WiMax), Wireless Local Area Network ( WLAN), UltraMobile Broadband (UMB), Bluetooth (BT), Near Field Communication (NFC), WiFi or infrared transmitter to name just a few possible examples of wireless communication.

For the sake of simplicity, as shown in Figure 1B, only one control unit 115 is shown, where functions for a plurality of different control functions have been assembled, such as control of the AMT gearbox 113 and its side axle brake 250, but in other embodiments the vehicle 100 may include a plurality of control units. can be distributed.

Figure 2 schematically shows an AMT gearbox 113 in the vehicle 100. The AMT gearbox 113 includes a split gearbox 210 and a main gearbox 220. Furthermore, in some embodiments, the AMT gearbox 113 may comprise a range gear (not shown) which may be a planetary gearbox. Adjacent to the split gear 210 is a side shaft 230.

The side axle brake 250 is arranged to act on the side axle 230, regulated by the control unit 115, by applying a friction coating on the side axle brake 250 against the side axle 230, in order to lower the speed thereon.

The control unit 115 is arranged to forecast or calculate an estimated braking energy in the friction lining of the side axle brake, based on, for example, speed change on the side shaft 230, current gear to be loaded (and thus rotational inertia), and measured or estimated oil temperature in the gearbox 113. vis is calculated by: E = [Rßuš-wš) 2 - ED; where: E = decelerated energy, IR = reflected mass inertia on the current axis, m2 = final rotational speed, m1 = initial rotational speed, ED = energy losses in oil, bearings, teeth etc.

ED is temperature dependent and can be calculated if the temperature is known, for example through the temperature sensor, or otherwise estimated or assumed to be a constant value as measured at operating temperature, as the majority of changes can be estimated at operating temperature. The decelerated energy E can therefore be assumed to be proportional to the speed difference. certain embodiments.

By forecasting or calculating an estimated decelerated energy E in the friction lining of the side axle brake, instead of measuring the instantaneous temperature in the friction lining, it can be predicted that an overload will occur in the friction lining by comparing this predicted decelerated energy E with a limit value G. Furthermore, when this occurs, a proactive package of measures can be activated to prevent such overheating of the friction lining from occurring.

If a measurement of the temperature of the friction coating is made, it can only be established afterwards that the friction coating has been overloaded and reactively possibly limited that the overheating that has already occurred is exacerbated. Measuring the temperature of the brake lining is also difficult and requires specially adapted and thus expensive measuring equipment.

If the accumulated amount of energy E within a certain time interval exceeds a predetermined limit value G, the control unit 115 can perform a measure which reduces or eliminates braked energy E in the friction pads of the side axle brake and thereby prolongs the life of said pads.

The predetermined limit value G can be determined based on, for example, friction coating cooling capacity, thermal inertia, temperature resistance, wear properties under high temperature, cooling stability and / or similar properties. Furthermore, the predetermined limit value G may refer to either energy in a braking of the side axle or accumulated energy over a certain period of time.

Such an action as the control unit 115 may perform may include, for example, synchronizing the gearbox 113 by changing the engine speed with the clutch 114 closed, which may include braking with the engine 110 on the input shaft 112. In some embodiments the split gear is engaged in neutral during shifting, even when split gear would not normally have been shifted, to reduce the inertia (and thus the energy development E) to which the side axle brake 250 and the friction pad are exposed. The control unit 115 can also in certain embodiments be modified to request the gear selection by, for example, taking several small gear steps with cooling time between the place of a large gear step; alternatively do not shift at all by inhibiting shifting for a period of time. According to other embodiments, the control unit 115 may also be arranged to use other braking devices in the gearbox 113 to spread the load, for example a brake on the input shaft 112, and / or split synchronization.

In some embodiments, the gearbox 113 may include both synchronizing units (not shown) and side axle brake 250. The controller 115 may then alternate synchronizing method between using side axle brake 250 and synchronizing unit for this purpose. This reduces the risk of overheating in the friction liner, both in the synchronizing units and in the side axle brake 250. Thereby a further improvement of braking capacity and extension of life of friction lining on both side axle brake 250 and synchronizing units can be compared with prior art synchronization units.

By performing at least one of these actions, the life of the friction coating isidoaxel brake 250 can be extended. Furthermore, the risk of overloading the friction pad isidoaxel brake 250 can be eliminated, or at least reduced. Since the temperature of the friction lining can be kept below a certain limit value, it is ensured that the lining has the desired friction number and thus maximum braking performance when needed, which gives a short changeover time and thus a shorter time in torqueless state in the driveline. This results in improved shifting performance as the vehicle 100 does not lose as much speed during shifting as in prior art methods. Another advantage that the above measures entail is that oxidation of the gearbox oil is reduced when the temperature of the oil is kept down.

Oxidation of the gearbox oil causes a number of deteriorations in the properties of the gearbox oil such as increased viscosity, corrosion, lowered flash point and leads to clogging of filters and resinous coatings in the gearbox 113, which can damage the gearbox 113 in various ways.

By reducing the oxidation of the gearbox oil, its service life is extended, which means lower costs for oil change and cleaning. Furthermore, an unchanged (or less varying) viscosity (due to less heating of the oil) results in less wear and abrasion in bearings and sliding surfaces on components in the gearbox 113.

In some embodiments, some or all of the listed measures for reducing or eliminating braked energy E in the friction lining of the side axle brake may be applied in a hierarchical order, where a plurality of limit values G1, G2, G11 may be used, where G1 <G2 ., <Gn.

For example, when the forecast decelerated energy E <G1, braking with the side axle brake 250 can be done without action to reduce developed heat energy E, according to certain embodiments. Furthermore, then G1 <E <G2, according to certain embodiments, the heat energy E can be reduced by synchronizing the gearbox 113 with closed clutch 114; and / or that the gearbox split gear is engaged in neutral before synchronization of the gearbox 113 is performed. When G2 <E <G3, the friction-inhibiting action may include braking with the vehicle's motor 110 on the gearbox input shaft 112 and / or splitting synchronization. When G3 <E, the measure may include that switching is prevented, within a certain predetermined time period.

An advantage of this embodiment is that with a limited forecast energy load E on the friction pad, only friction-inhibiting measures are performed which do not at all, only marginally, affect the driver's experience of the shift. In this way it is possible to completely prevent a certain shift from being carried out, which is likely to have a negative effect on the driver's driving experience; or at least only prevent such switching from taking place when the forecast energy load E on the friction coating exceeds a very high limit value Ghög, where G << Ghög and no other measure seems to be able to reduce the overload.

Figure 3 illustrates an example embodiment of the invention. The flow chart in Figure 3 illustrates a method 300 in a control unit 115 for controlling an AMT gearbox 113 in a vehicle 100 to avoid overheating of a side axle brake 250 and one or more friction pads in the gearbox 113. The friction pad is included in the side axle brake surface 250 and is the friction surface 250. in the side-axle brake 250 which is applied to the side-axle 230 during speed synchronization by braking the side-axle 230. The AMT gearbox 113 may comprise a single-split gear 210 and a main gear 220. Optionally, a range gear may also be included in certain embodiments.

The purpose of the method 300 is to reduce the heat energy generated in the side axle brake250 and its friction lining in connection with shifting according to a shift request. In this way, the service life of the friction lining of the side axle brake can be extended.

In order to be able to control the gearbox 113 in the vehicle 100 in a good way to avoid overheating of a side axle brake 250 and its friction lining, the method 300 may comprise a number of steps 301-304. It should be noted, however, that some of the steps 301-304 described herein include alternative embodiments. Method 300 includes the following steps: Step 301 A change request is detected.

Such a shift request can be detected, for example, when the engine speed, or other shift control parameter exceeds a certain shift point for a new higher gear; alternatively falls below a certain gear point for a new lower gear. Different gear points may be associated with different gears. Furthermore, in some embodiments gears can be skipped, such as one gear, two gears, three gears, etc., depending on which gear point has been reached.

For example, such shift control parameters can be determined by measuring engine speed with a sensor 111 in certain embodiments. Such measurement can be performed continuously, or with a certain time interval according to different embodiments. Furthermore, according to certain embodiments, the shift control parameter may comprise a plurality of parameters, including for example one or more of the parameters speed, speed, rolling resistance, road inclination, crew weight, speed, outdoor temperature, forecast speed of alternative gear, forecasted effect on alternative gear, accelerating power, comfort level and / or vehicle speed, to name a few examples.

The determination of parameter value may in this case include the collection of the relevant parameters and the calculation according to a weighted algorithm of the value of the shift-controlling parameter, according to certain embodiments.

Step 302A speed change to synchronize the speed on the side shaft 230 with the speed on the main shaft due to the requested upshift detected is calculated. The change in speed refers to the side axle 230.

This speed change may include a change in the speed of the side shaft 230 from a first speed m1 to a second speed m2.

To obtain the speed change, one can measure or calculate the input shaft speed or the side shaft speed (what distinguishes between these is the gear ratio between the pair of gears which connects the input shaft 112 to the side shaft 230, which makes it easy to calculate the side shaft speed). the side shaft 230, for example 12 with a speed sensor, which means that the input shaft speed does not need to be determined for this purpose. With the help of the side axle speed and knowledge of the gearbox gear ratio, you can calculate the speed of the gear that sits on the main axle and is driven by the side axle 230. Now you have obtained one speed m1. In order to obtain the second speed m2 with which the first shaft is compared, you need to know the main shaft speed, which can be measured directly or how to calculate it with the help of the output shaft speed. Now one can calculate what change in the speed of the side shaft 230 can be made to synchronize the speed of the side shaft 230 with the speed of the main shaft.

Step 303A forecast is made of heat energy E that develops in the side axle brake 250 and its friction coating when braking the side axle 230, based on the calculated 302 speed change of the side axle 230.

The forecast of the heat energy E which develops in the side-axle brake 250 and its friction lining when braking the side-axle 230 can according to one embodiment be calculated according to: E = IRQuš-wš) 2 - ED; where E = decelerated energy, IR = reflected mass inertia on the current axis, m2 = final rotational speed, m1 = initial rotational speed, ED = energy losses in oil, bearings, teeth etc.

This calculated heat energy E may comprise, for example, forecast developed heat energy in a single braking or accumulated heat energy E over a certain period of time, according to different embodiments.

Step 304A measure is initiated, to reduce the heat energy E which develops in the side shaft brake 250i in connection with shifting according to the detected 301 upshift request, when the predicted 303 heat energy E exceeds a limit value G.

Such limit value G may refer to either the permitted maximum heat energy in a braking or the permitted maximum accumulated energy over a certain period of time.

Such a measure to reduce the heat energy E developed in the side axle brake 250 and its friction pads may in some embodiments include synchronization of the gearbox 113 with closed clutch 114. The internal combustion engine is adjusted to the speed that gives a synchronous speed between the main shaft and the current gear. The measure for reducing the heat energy developed in the side axle brake 250 may alternatively also include synchronization by means of the clutch plate. While the clutch is open, the internal combustion engine 110 can be adjusted to the speed that gives a synchronous speed between the main shaft and the current gear to be engaged. The clutch 114 can then be closed and the lamella can synchronize the speeds in certain embodiments.

In other embodiments, the action of reducing the heat energy E generated in the side axle brake 250 and its friction lining may include loading the gearbox split gear neutrally before synchronizing the gearbox 113 is performed whether or not this is actually needed to perform the shift. As a result, the input shaft 112 is disconnected and the clutch plate, whereby the mass which must be braked by the side shaft brake 250 is reduced by this embodiment as well, which in turn leads to lower energy development E in the friction lining.

In certain embodiments, when the detected 301 upshift request involves skipping at least one shift step, the measure of reducing the heat energy E generated in the side axle brake 250 and its friction lining may include modifying the shift request by taking at least one shift step, e.g. predetermined time periods or cooling time between. Such a predetermined cooling time can be determined depending on the type of friction pad in the side axle brake 250 and the capacity of this pad.

By dividing a multi-stage gearing into, for example, two single-stage gears where one gear only includes split gearing and thus does not affect the side axle brake 250, a lower heat generation is obtained in the side shaft brake 250. The measure to reduce the heat energy E developed in the modified shaft switching request by preventing switching from taking place before a certain predetermined or configurable time period or cooling time has elapsed. Such predetermined time period can be set to a few seconds, or a few minutes in various embodiments; for example, depending on the vehicle type, type of friction lining, the magnitude of the braked energy E, the temperature of the friction lining and / or another similar parameter.

Furthermore, the measure for reducing the heat energy E which develops in the side axle brake 250 / friction lining may alternatively include braking with the vehicle's engine 110 on the gearbox input shaft 112. This does not load the side axle brake 250 at all but allows it to cool down during this time.

According to some further embodiments, the measure of reducing the heat energy E developed in the side axle brake 250 may include the use of synchronizing units. This embodiment assumes that the gearbox 113 is provided with both a side axle brake 250 and at least one synchronizing unit for synchronizing the side axle 230. By alternating between braking the side axle 230 with the side axle brake 250 and the synchronizing unit, the friction load between each friction load can be reduced.

Said measure for reducing the heat energy E which develops in the side axle brake 250 and its friction pads may in certain embodiments comprise an alternation between several of the measures described above for reducing the developed heat energy E. This can further develop the energy development E in the side axle brake 250 and the pad. service life of the friction lining.

Such alternation can in some embodiments be done by performing actions in a certain hierarchical order, where a first action may include loading the gearbox split gear in neutral before synchronizing the gearbox 113 is performed. A second action that can be performed then the prediction of heat energy E that develops in the side shaft brake 250 exceeds a limit value may include the use of an additional synchronization unit or other synchronization unit, in the embodiments where this is present. Another measure may be to carry out a motorized shift. Another measure may be to modify shift selection as well as prevent shifting from being performed before a certain predetermined time period has elapsed, according to certain embodiments.

Motor-controlled shifting means that you adjust the speed of the motor to the speed that gives synchronous speed between the main shaft and the gear to be engaged. This means that this action does not need to be combined with anything else as it solves the synchronization work.

Figure 4 illustrates an embodiment of a control unit 115 arranged to control an AMT gearbox 113 in a vehicle 100, in order to avoid overheating of a side axle brake 250 and its friction lining in the gearbox 113. The friction lining, which may be one or more, is included in the side-axle brake 250 and constitutes the friction surface in the side-axle brake 250 which is applied to the side-axle 230 during speed synchronization by braking the side-axle 230. The gearbox 113 may comprise a split gear 210 and a main gear 220.

This control unit 115 is configured to perform at least some of the previously described method steps 301-304, included in the description of the method 300 for controlling the gearbox 113 in the vehicle 100.

In order to be able to correctly control the shifting of the gearbox 113, the control unit 115 contains a number of components, which are described in more detail in the following text. Some of the described sub-components occur in some, but not necessarily all, embodiments. There may also be additional electronics in the control unit 115, which is not absolutely necessary to understand the function of the control unit 115 according to various embodiments of the invention.

The control unit 115 comprises a processor circuit 420, arranged to detect an upshift request and also arranged to calculate a speed change on a side shaft 230 in the gearbox 113, to synchronize the speed of the side shaft 230 with the speed of the main shaft 112 due to the requested upshift. Furthermore, the processor circuit 420 is also arranged to forecast heat energy E which develops in the side shaft brake 250 and its friction coating during braking of the side shaft 230, based on the calculated speed change. The processor circuit 420 is also arranged to initiate a measure to reduce the heat energy As developed in the side shaft brake 250 in connection with shifting according to the detected upshift request, when the predicted heat energy E exceeds a limit value G.

In addition, the processor circuit 420 may also be arranged to initiate synchronization of the side shaft 230 by generating a control signal to the side shaft brake 250, and to perform shifting to the requested gear when the synchronization is done.

According to certain embodiments, the processor circuit 420 may also be arranged to reduce the heat energy E generated in the side axle brake 250 and its lining by modifying the shift request by preventing shifting from being performed in the gearbox 113 before a certain predetermined period of time has elapsed.

The processor circuit 420 may also be arranged to generate a control signal for braking the input shaft 112 of the gearbox with the engine 110 of the vehicle and thereby reducing the heat energy E developed in the side axle brake 250 / friction lining. Furthermore, the processor circuit 420 may also be arranged to reduce the heat energy E generated in the side axle brake 250 and its friction lining by sending control signals to perform split synchronization, according to certain embodiments.

In addition, the processor circuit 420 may also be arranged to alternate between a plurality of measures to reduce the heat energy E generated in the side shaft brake 250 and its friction pads. Such alternation may in some embodiments be made by performing actions in a certain hierarchical order, where a first group of actions may include synchronizing the gearbox 113 with closed clutch 114, and loading the gearbox split gear neutral before synchronizing the gearbox 113 is performed . A second group of actions which may be performed when the forecast of heat energy E generated in the side axle brake 250 exceeds a limit value may include braking with the vehicle's engine 110 on gearbox input shaft 112 and / or reducing the heat energy E generated in the side axle brake 250 by split synchronization. Another group of actions that can be performed then the prediction of heat energy E developed in the side axle brake 250 exceeds a limit value G may include modification of the shift request by preventing shifting from being performed before a certain predetermined time period has passed, according to certain embodiments.

Furthermore, the processor circuit can also be arranged to forecast the heat energy E which develops in the side shaft brake 250 / the friction lining when braking the side shaft 230 by calculating the energy E according to: E = -ED, where: IROßš-wš) 2E = decelerated energy, IR = reflected mass inertia on current axis, m2 = final rotational speed, m1 = initial rotational speed, ED = energy losses in oil, bearings, teeth etc.

The processor circuit 420 may be, for example, one or more CPUs (Central ProcessingUnit / s), microprocessor or other logic designed to interpret and execute instructions and / or to read and write data. The processor circuit 420 may handle data for inflow, outflow or data processing of data including including buffering of data, control functions and the like.

In some embodiments, the processor circuit 420 may be arranged to perform a measure to reduce the heat energy E generated in the side axle brake 250 and its friction lining by generating and sending a control signal for synchronizing the gearbox 113 with closed clutch 114. The processor circuit 420 may also be provided to reduce the heat energy E developed in the side axle brake 250 and the friction lining by generating and sending a control signal for loading the gearbox split gear in neutral before synchronizing the gearbox 113 is performed.

Furthermore, in some embodiments, the processor circuit 420 may be arranged to, when the detected upshift request includes skipping at least one shift step, generate and send a control signal to modify the shift request by taking at least two shift steps with a predetermined time period between and thereby reducing developed in the side axle brake 250 and its friction lining.

The processor circuit 420 may also be arranged to determine a shift control parameter, based on one or more of: speed, vehicle speed, rolling resistance, road slope, crew weight, speed, outdoor temperature, forecast speed on alternate gear, forecast power on alternate gear , accelerating power, comfort level, for example.

The control unit 115 may also comprise a transmitting circuit 430, arranged to send a control signal, for example to the side axle brake 250, to effect shifting to the requested gear. The transmitting circuit 430, may be arranged to send a control signal to perform switching to the requested gear to the gearbox 113.

The control unit 115 may also comprise a receiving circuit 410 in certain embodiments, arranged to obtain a speed; or a parameter value for a shift control parameter. For example, obtaining such a parameter value may include reading a sensor111 of instantaneous speed level on the vehicle's engine 110. In this case, the sensor 111 is often referred to as a speed sensor, speed counter and / or speed sensor.

In some embodiments, the controller 115 may also include a memory unit 425, which is a non-volatile data storage medium. Such memory 425 may be provided to store information regarding gears, gear points, speed intervals for loading a certain gear, target speeds associated with a certain gear, limit values G, predetermined time period and similar information which may facilitate loading of a new gear.

The memory unit 425 can be, for example, a memory card, flash memory, USB memory, hard disk or other similar data storage device, for example one of the group: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (ErasablePROM), Flash memory, EEPROM (Electrically Erasable PROM), etc. in various embodiments. Furthermore, according to certain embodiments, the invention includes a computer program for controlling the AMT gearbox 113 in a vehicle 100 to avoid overheating of a side axle brake 250 and its friction lining in the gearbox 113. Such a computer program may include performing the method 300 according to any of steps 301-304 when the computer program executed in a processor 420 in a controller 115. The computer program is arranged to perform the method 300 according to at least one of the previously described steps 301-304, when the computer program is executed in the processor 420 in the controller 115, together with computer program code to execute any, some, some or all of the steps 301-304 described above. Thereby, a computer program including instructions for performing steps 301-304 can control the AMT gearbox 113 and generate a control signal to initiate a measure to reduce the heat energy E developed in the side shaft brake 250 / friction pad in conjunction with the detected gear shift request. the heat energy E exceeds a limit value G and when the computer program is loaded in the processor circuit 420.

Some embodiments of the invention also include an AMT gearbox 113 in a vehicle 100, where the gearbox 113 is controlled by a control unit 115 to avoid overheating of a side-axle brake 250 / its lining in the gearbox 113. The side-axle brake 250 is arranged adjacent to the side-axle 230 in gearbox 113.

Some embodiments of the invention also include a system for controlling an AMT gearbox 113 in a vehicle 100, to avoid overheating of a side axle brake 250 in the gearbox 113. Such a system may include a control unit 115 described above; a sensor 111, arranged to read speed and an AMT gearbox 113 in the vehicle 100. Some embodiments of the invention also include a vehicle 100, which comprises the AMT gearbox 113 described above.

Claims (13)

538 357 PATENT REQUIREMENTS A method (300) in a control unit (115) for controlling an Automated Manual Transmission, AMT, gearbox (113) in a vehicle (100) to avoid overheating of a side axle brake (250) in the gear clan (113), wherein the method (300) may be characterized by: detecting (301) a gear request; calculating (302) a speed change on a side shaft (230) in the gear shaft (113), to synchronize the speed on the side shaft (230) with the speed on the main shaft (112) to WO of the requested upshift; forecasting (303) of heat energy generated in the side axle brake (250) when braking the side axle (230), based on the calculated (302) speed change; starting (304) of an actuator to reduce the heat energy generated in the side axle brake (250) in connection with shifting according to the detected (301) upshift request, then the forecast (303) heat energy exceeds a spruce value execution of the upshift. The method (300) of claim 1, wherein the algarden for reducing the heat energy generated in the side axle brake (250) comprises motorized synchronization of the gear shaft clan (113) with rod clutch (114). The method (300) of claim 1, wherein the act of reducing the heat energy generated in the side axle brake (250) comprises synchronizing by means of the clutch plate. The method (300) of claim 1, wherein the step of reducing the heat energy generated in the side axle brake (250) comprises applying the gearshift split shaft to neutral before synchronizing the gearshift (113) is performed. The method (300) of any of claims 1-4, wherein the detected (301) upshift request comprises skipping at least one shift step, wherein the actuator for reducing the heat energy generated in the side axle brake (250) comprises modifying the shift upshift by taking at least two alternating steps. The method (300) of any of claims 1-3, wherein the act of reducing the heat energy generated in the side axle brake (250) comprises braking with the vehicle engine (110) on the input shaft (112) of the gearbox. 19 538 357 The method (300) of any of claims 1-6, wherein the act of reducing the heat energy generated in the side axle brake (250) comprises applying the split shaft to neutral, after which split synchronization is then used to load again. The method (300) of any of claims 1-7, comprising alternating between a plurality of steps to reduce the heat energy generated in the side axle brake (250). The method (300) according to any one of claims 1-8, wherein the forecasting (303) of the heat energy developed in the side axle brake (250) during braking of the side axle (230) is calculated according to: E = IR (64-`4) OATH; dar 2 E = decelerated energy, IR = reflected mass inertia on current axis !, w2 = final rotational speed, w1 = initial rotational speed, ED = energy losses in oil, bearings, gear. Control unit (115) arranged for controlling an Automated Manual Transmission, AMT, gearbox (113) in a vehicle (100) to avoid overheating of a side axle brake (250) in the gearbox (113), where the control unit (115) can be marked by : a processor circuit (420), arranged to detect an upshift request; and also arranged to calculate a change in speed on a side shaft (230) in the gearbox (113), in order to synchronize the speed on the side shaft (230) with the speed on the main shaft (112) as a result of the requested upshift; and also arranged to forecast heat energy generated in the side axle brake (250) during braking of the side axle (230), based on the calculated change in speed; and also arranged to initiate an action to reduce the heat energy developed in the side axle brake (250) in connection with shifting according to the detected upshift beverage, when the predicted heat energy exceeds a spruce value. A computer program for controlling an AMT gearbox (113) in a vehicle (100) to avoid overheating of a side axle brake (250) in the gearbox (113), comprising performing the method (300) according to any one of claims 1-9 da. the computer program is executed in a processor circuit (420) in a control unit (115) according to claim 10. AMT gearbox (113) in a vehicle (100), wherein the gearbox (113) is controlled by a control unit (115) according to claim 10, wherein the gearbox (113) comprises a side axle brake (250) arranged in connection with the side axle (230) i vaxelladan (113). A vehicle (100) comprising an AMT gearbox (113) according to claim 12. 538 357 1/4