SE538545C2 - Method and system for heating a vehicle component next to a vehicle - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to a method of use via a vehicle. In particular, the invention relates to a method for heating at least one vehicle component in a vehicle according to the preamble of claim 1. The invention also relates to a system and a vehicle, as well as a computer program and a computer program product, which implement the method according to the invention.

Background of the Invention The following background description constitutes a background description of the invention, and thus does not necessarily constitute prior art.

With regard to vehicles in general and at least to some extent heavy vehicles in particular, there is a constant development in search of fuel efficiency and reduced exhaust emissions. Due to e.g. increased government interests regarding pollution and air quality in e.g. urban areas, emission standards and regulations have been developed in many jurisdictions.

Such emission regulations often constitute SEK settlements which define acceptable limits for exhaust emissions in vehicles equipped with internal combustion engines. For example, levels of emissions of nitrogen oxides (NOX), hydrocarbons (HC) and carbon monoxide (CO) are often regulated. These emission regulations also usually deal, for at least certain types of vehicles, with the presence of particles in exhaust emissions.

In an effort to comply with these emission regulations, the exhaust gases caused by combustion are treated (purified) for nine years. T. e x. k a n e n s. k. k a t a 1 y t in so-called purification process is used, why also after-treatment systems, such as in e.g. vehicles and other vehicles, usually include one or more catalysts.

Furthermore, such after-treatment systems, alternatively or in combination with the one or more catalysts, often include other components. For example, after-treatment systems via diesel-powered vehicles often include particulate filters to capture soot particles formed during combustion. Thus, there are a number of methods for reducing emissions from an internal combustion engine.

However, there are situations where unwanted exhaust emissions can nevertheless occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of heating at least one vehicle component of a vehicle. The present invention relates to a method according to claim 1, The present invention relates to a method for heating at least one vehicle component of a vehicle, said vehicle comprising an internal combustion engine, and at least a first electric machine, said first electric machine being arranged for selective application of a force to a shaft output via said internal combustion engine. The method comprises applying to said output shaft of said internal combustion engine a first braking force by utilizing said first electric machine.

As has been mentioned, it is desirable that exhaust emissions from vehicles be avoided or reduced as much as possible, which e.g. can be performed using a finishing system. However, there are situations, such as during a cold start of the vehicle, when unwanted emissions can occur due to the low temperature of the internal combustion engine (combustion chamber). For example. can injected fuel condense against e.g. cylindrical walls in a cylinder when the temperature is low, a..11, e r n a t i v t., or they s s u t o m, may for incineration under certain conditions become incomplete, with the result that unwanted white smoke is formed and emitted.

However, a cold-started internal combustion engine, especially for heavy vehicles, can take a relatively long time to warm up, especially when idling. The heating process in situations such as. t. round operation, can be accelerated by. increase the load of the internal combustion engine. For example. an exhaust brake could be applied to restrict the exhaust flow with increased internal combustion engine load, and thus faster heating of the internal combustion engine, as a result. Adjustment of the exhaust brake can, however, be. difficult to perform with. sufficient accuracy in e.g. the situations the vehicle simultaneously begins to move.

The present invention relates to hybrid vehicles, and uses the hybrid part to enable a faster heating of combustion engines. can be used to generate a force acting on the vehicle's drive wheel. The electric machine has the advantage that electrical energy can be converted into a propulsive force with one. relatively high efficiency using the electric machine, while. The electric machine can also be used to regenerate electrical energy of absorbed kinetic energy by feeding a braking force to the vehicle's drive wheel for feedback to the vehicle's electrical system, and in particular to a. energy storage. The. regenerated energy can then be used by the electric machine to generate a propulsion force.

According to the present invention, after the internal combustion engine has been started, the electric machine is used to apply a braking force to said output shaft of said internal combustion engine. In this way, the load of the internal combustion engine can be increased at e.g. situations where the internal combustion engine otherwise e.g. had worked at idle, or only with very little load, with the result that a faster heating and / or more complete combustion of injected fuel is obtained. The invention also has the advantage that the braking force, i.e. Internal combustion engine braking force applied by the electric machine will generate an electric current, whereby the absorbed braking energy can be taken care of and returned in electrical form to an energy storage, and / or for conversion to heat for heating one or more vehicle components.

Compared with e.g. using an exhaust brake, the invention also has the advantage that the applied load can be calculated / controlled with high accuracy, whereby control of the internal combustion engine when propelling the vehicle can be controlled in a way which also results in the desired driving force applied to the vehicle's drive wheel. When propelling at the same time as the exhaust brake is activated, it can be difficult to ensure that the desired driving force applied to the vehicle's drive wheel is also obtained, with the consequence that the activation of the exhaust brake is normally interrupted when driving force is requested.

According to the invention, the internal combustion engine is loaded by the electric machine only as long as the total load of the internal combustion engine from the electric machine together with the load from the vehicle's drive wheels is less than a certain load, such as a maximum of 10-500 Nm, or a certain proportion of the internal combustion engine.

The present invention provides a method wherein it, e.g. by the driver of the vehicle, the driving force requested on the vehicle's drive wheel is wholly or at least substantially maintained, but where the electric machine applies an additional load to the internal combustion engine. This causes the internal combustion engine to be forced to deliver a higher work to compensate for the braking force applied by the electric machine, but where the electric machine and internal combustion engine can thus balance each other so that the force applied to the vehicle's drive wheel remains the same even though the internal combustion engine emits a higher work, and thus can heat up faster.

According to the above, the electric machine can be used to apply a braking force to the vehicle's drive wheels, and thereby regenerate electrical energy from absorbed kinetic energy, ie. the electric machine can be used for so-called regenerative braking in order to recover energy when driving the vehicle e.g. in closures. The present invention can also be applied to such situations. The present invention has for its object to heat up in particular the internal combustion engine. Normally during regenerative braking, the internal combustion engine is towed, sec. the internal combustion engine is driven with the fuel injection switched off. Such situations are disadvantageous from a heating point of view, since the internal combustion engine is instead cooled by the combustion air passing through the combustion chamber (eg cylinders) of the internal combustion engine when no combustion takes place in the combustion chambers.

According to an embodiment of the present invention, the desired heating of the internal combustion engine can be ensured even in situations where the internal combustion engine is normally towed. In such situations, a higher force of the electric machine is applied than what. which would otherwise be applied during the regenerative braking, the internal combustion engine being controlled to deliver a positive work corresponding to the extra load, whereby fuel injection is required so that the force acting on the vehicle's drive wheel is not altered in the practice of the present invention. The present invention can thus be used to ensure the desired heating regardless of the driving situation. As will be appreciated, the use of the electric machine of the present invention thus constitutes a use which is "backwards" compared with the normally energy-saving aspect in which the electric machine is normally used.

Additional features of the present invention and. advantages thereof will become apparent from the following detailed description of exemplary embodiments and the accompanying drawings.

Brief Description of the Drawings Fig. 1. Refers to a driveline, in a vehicle to which the present invention relates. advantage can be used. Fig. 1B shows an exemplary control unit in a vehicle control system. Fig. 2 shows a part of the vehicle shown in Fig. 1A in more detail.

Fig. 3 shows an exemplary method according to the present invention, Fig. 4 shows an example of control according to the present invention at a. situation where so-called towing normally advises.er.

Detailed Description of Preferred Embodiments The present invention will now be exemplified in connection with a hybrid vehicle. In general, FIG. 1A schematically shows a driveline in a hybrid vehicle 100 according to an embodiment of the present invention. There are hybrid vehicles of various types, and the vehicle 100 shown is a parallel hybrid vehicle.

The vehicle 100 schematically shown in Fig. 1A comprises only one axle with drive wheels 113, 114, but the invention is also applicable to vehicles where more than one axle is provided with drive wheels, as well as, also to vehicles with one or more additional axles, such as a or several support shafts.

The parallel hybrid powertrain of Fig. 1.A includes an internal combustion engine 101. The internal combustion engine 101 is connected in a conventional manner, via an axis of the internal combustion engine 101, usually via a flywheel 102, to a gearbox 103 via a clutch 106. .

The internal combustion engine 101 is controlled by the control system of the vehicle via a control unit 115. Likewise, the clutch 106, which e.g. may be an automatically controlled, clutch, and gearbox 103 of the vehicle control system by means of a control unit 116.

Gearboxes in heavy vehicles, as in the embodiment shown, often consist of an automatically (by means of the vehicle control system) shifted "manual" gearbox 103, the clutch 106 selectively connecting the output shaft 102 of the internal combustion engine 101 to the gearbox 103. The clutch 106 is in the present example of an off-vehicle control system automatically controlled clutch, but may alternatively be a manually controlled clutch.

The vehicle further comprises drive shafts 104, 105, which are connected to the drive wheels 113, 114 of the vehicle, and which, as in a conventional internal combustion engine system, are driven by a shaft 107 emanating from the gearbox via a. final gear, such as e.g. a conventional differential 108. Unlike a conventional vehicle, the vehicle shown in Fig. 1A also comprises a hybrid part with an electric machine 110, which is connected to the input shaft 109 of the gearbox 103, "downstream" of the clutch 106, i.e., the input shaft of the gearbox. 109 can be driven by the electric machine 110 even in the case where the coupling 106 is open. Parallel hybrid vehicles can thus transmit power to the drive wheels 113, 114 from two separate power sources simultaneously, ie. both from. the internal combustion engine 101 and the electric machine 110. Alternatively, the vehicle can be propelled by either the power source separately, i.e. The present invention is also applicable to other types of hybrid vehicles, as long as the internal combustion engine can be loaded by one. electric machine. The vehicle may also include two or more electric machines. The vehicle can, for example, also be of a type with a conventional automatic gearbox, with the electric machine arranged upstream or downstream of the gearbox. The vehicle shown in Fig. 1A also includes a post-treatment system 117 for purifying the exhaust gas stream resulting from the combustion of the internal combustion engine, the functions of which are controlled by a control unit 118. The figure also shows an exhaust brake system 119 for throttling the combustion engine. res u 1 teration of gas flow n.

Furthermore, the hybrid part comprises additional components. In Fig. 1A. only the electric machine 110, an energy storage 111 and a hybrid control unit 112 are shown, which is responsible for the function of the hybrid part. Fig. 2 shows the hybrid part in a little more detail. The electric machine 110 is supplied with a power supply with a variable feed frequency, which means that the electric machine can be made to rotate an axis with arbitrary rotational speed and arbitrary torque within the electric machine's speed / torque range. In the example shown, the electric machine 110 is supplied with power via a power electronics unit 210, which generates said feed frequency, from the energy storage 111. The energy storage 111 may be arranged to be charged by regenerative braking by means of the electric machine 110 and the power electronics unit 210, but also in other ways, e.g. via connection to an external, power source, such as a conventional electricity network. Fig. 2 also shows further components, which are further explained below.

Thus, the electric machine 110 can be used for propelling the vehicle 100 at a substantially arbitrary speed by means of frequency control, and for applying a substantially arbitrary braking force acting on the vehicle's propulsion. This is utilized by the present invention.

According to the above, the function of the vehicle components shown is controlled by a plurality of control units. In general, control systems in modern vehicles usually consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECUs), or controllers, and. various on the vehicle, arranged components. Such a control system can comprise a large number of control units, and the responsibility for a specific function can be divided into more than one control unit.

For the sake of simplicity, in Fig. 1A only the control units 112, 115-116, 118 are shown, but vehicles 100 of the type shown often comprise considerably more control units, which is well known to the person skilled in the art. The control units 112, 115-116, 118 can communicate with each other via said communication bus system, which is indicated by dashes between the control units in the figure.

The invention can be implemented in any applicable control unit, and according to the example shown, the invention is implemented in the control unit 115 for controlling the internal combustion engine. However, the invention may also be implemented. in another applicable control unit, such as, for example, a dedicated control unit, the control unit 118 for controlling the finishing system or the hybrid control unit 112. The request of the control unit 115 (or the control unit (s) to which the present invention is implemented) for loading the internal combustion engine 101 by means of the electric machine 110 according to the invention will probably depend on signals received from the hybrid control unit 112, the control unit 116 for control of clutch / gearbox as well. other control units arranged via the vehicle and not shown, and / or information from, for example, various sensors / sensors arranged at the vehicle. In general, control units of the type shown are normally arranged to receive sensor signals from different parts of the vehicle 100. Control units of the type shown are also usually arranged to emit control signals to different vehicle parts and components. T. e x, k ome r s t. y r e n h eten a 1.1 a v g e s i g n a 1 e r to the control unit 112 for requesting braking power of the electric machine, The control is often controlled by programmed instructions. These programmed instructions typically consist of a computer program, which when executed in a computer or controller causes the computer / controller to perform the desired control, such as method steps of the present invention. The computer program usually forms part of a computer program product, the computer program product comprising an applicable storage medium 121 (see Fig. 1B) with the computer program stored on said storage medium 121. Said storage medium 121 may e.g. consists of any of the group: ROM (Reaa-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc, and be arranged in or in connection with. the control unit, whereby, the computer program.ram.met is executed by the control unit. Thus, by changing the instructions of the computer program, the behavior of the vehicle in a specific situation can be adapted. any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or an Application Specific Integrated Circuit (ASIC). The computing unit 120 is connected to a memory unit 121, which provides the computing unit 120, for example, the stored program code or the stored data computing unit 120 is needed to be able to perform calculations. The computing unit 120 is also arranged to store partial or end results of calculations in the memory unit 121, Furthermore, the control unit 115 is provided with devices 122, 123, 124, 125 for receiving and transmitting input and output signals, respectively. These input and output signals may contain waveforms, pulses , or other attributes, which of the input signals receiving devices 122, 12 may be detected as information for processing the computing unit 120. The output signals 123, 124 for transmitting output signals are arranged to convert calculation results from the computing unit 120 to output signals for transmission to other parts. of the vehicle's control system and / or the component (s) for which the signals are intended. Each of the terminals of the devices for receiving and transmitting input and output signals, respectively, may be one or more of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems Transport), or any other bus configuration; or of a wireless connection. Fig. 3 shows an exemplary method 300 according to the present invention. The process begins in step 301, where it is determined whether the internal combustion engine 101 of the vehicle 100 is started, e.g. by determining whether the speed of the internal combustion engine consists of at least one idle speed. If so, the process proceeds to step 302. According to one embodiment of the invention, an additional criterion is applied at the transition from step 301 to step 302, such as, for example, determining whether the internal combustion engine 101 has been started for a certain time such as e.g. parts of a second or a certain number of seconds, which e.g. may be desirable from, for example, wear or other considerations such as e.g. to ensure that the internal combustion engine is actually started. It may also / alternatively be desirable that the function according to the present invention, i.e. to apply braking force by means of the electric machine 110, is started within a certain ten t from the time that the internal combustion engine 101 has been started, e.g. in order to reduce emissions as quickly as possible. Tiden tikan e.g. be short, and e.g. constitute one or an applicable number of seconds in the interval 0-6 0 seconds from the fact that the internal combustion engine 101 has up to idle speed, i.e. has been started.

In step 302, it is then determined whether a. exhaust limitation function, such as e.g. a white smoke reduction function or other applicable exhaust emission control function shall be activated. This may, for example, be the case if a temperature T engine representative of the internal combustion engine 101 exceeds a limit value Ttootoriimi. The temperature Trr, or_or may be arranged to be determined in some applicable manner, and is represented by any temperature sensor arranged via the internal combustion engine 101. The temperature Tmot0r can also be. arranged to consist of a temperature representation calculated with the aid of an applicable calculation model, e.g. based on any temperature measured at the vehicle.

H u r u v i d a t. E x. V i t r öksbegrän s n in g s k a 11 a k. T i veras kan t. E x. may also be determined based on the ambient temperature of the vehicle 100 Toi; the driver or automatically by the vehicle's steering system.

If said limiting function is not / is to be activated, or the invention is not to be applied for some other reason, the procedure is terminated in step 306. This can e.g. This may be the case when the internal combustion engine 101 is started in a relatively short period of time from the time the internal combustion engine has previously been stopped with the result that the internal combustion engine still has the desired temperature. This may also be the case when the ambient temperature of the vehicle 100 is high. According to one embodiment, however, the function according to the present invention is always activated for as long as. the applicable temperature criterion for activating the function is met, ie. regardless of whether white smoke or other restriction function is activated. According to one embodiment, the function is always activated at the start of the internal combustion engine to ensure that the desired heating of the internal combustion engine is obtained.

If, on the other hand, it is determined in step 302 that measures are to be taken to limit white smoke and / or other exhaust emissions, the procedure proceeds to step 303, where it is determined whether the vehicle. 100 is stationary. If the vehicle 100 is stationary, the probability of the internal combustion engine operating at idle is also relatively high, with the result that it will also take a relatively long time before the internal combustion engine reaches the desired temperature. If, on the other hand, the vehicle 100 is in motion, there is also a high probability that the internal combustion engine 101 will develop a larger work with faster heating as a result.

According to one embodiment of the present invention, in step 303, it is not determined whether the vehicle 100 is stationary, but whether the speed of the vehicle 100 is less than any applicable speed such as e.g. 10 km / h or other applicable speed, and where vur5 can thus also be 0 km / h. Eg. the vehicle 100 can roll slowly, with the internal combustion engine 101 substantially idling under conditions where a very low power demand prevails, and the heating time of the internal combustion engine 101. thus still long.

The vehicle can also be driven with a trailing internal combustion engine, ie. with the fuel injection. off. In such situations there is no heating of the internal combustion engine at all, but instead a cooling, which is why the present invention is applicable for heating in such situations, especially when the vehicle is driven with a trailing internal combustion engine shortly after starting.

According to an embodiment of the present invention, it is determined in step 303 whether the parking brake is applied, and the vehicle is thus stationary, the condition in step 303 being considered to be fulfilled only if that is the case.

According to one embodiment, it is determined whether the current load of the internal combustion engine 101 is less than any applicable load Mn_ m, such as e.g. a load corresponding to a braking torque in the range 10-500 Nm, or in the range 2-50% of the maximum releasable torque of the internal combustion engine 101, or a torque less than the torque the electric machine 110 can emit. way is limiting. This can be arranged so that e.g. performed in a separate, step preceding or following step 303, alternatively replacing step 303, in which case the speed of the vehicle 100 is disregarded. If the load of the internal combustion engine 101 exceeds the applicable load, e.g. due to the fact that the driver of the vehicle 100 immediately after starting has requested a driving force which causes the load of the internal combustion engine 101 to exceed the load Miå, no additional braking force is applied by the electric machine 110.

If the condition of step 303 is not met, the procedure of step 306 is terminated.

If the one or more conditions according to step 303, and possibly further steps, are completed, the process proceeds to step 304. In step 304, an internal combustion engine braking force is applied by means of the electric machine 310. The braking force applied by the electric machine may be any applicable braking force resulting in a total internal combustion engine braking torque e.g., in the range 10 Nm-500 Nm. In the event that the vehicle 100 is stationary with the gearbox 103 in the neutral position, the electric machine 110 can apply all of this, braking force, including. When the vehicle 100 is in motion, the electric machine 110 can apply a braking force so that the total braking force acting on the internal combustion engine 101 amounts to the desired braking force.

At the same time, in cases where the vehicle is in motion, an adjustment of the internal combustion engine or electric machine is preferably carried out so that the force applied to the vehicle's drive wheel still consists of, or at least substantially consists of, the driving force required on the vehicle's drive wheel. is forced to work harder while maintaining the force applied to the drive wheels, whereby a faster heating is obtained at the same time as. the vehicle is still being driven according to the driver's wishes.

As will be appreciated, the internal combustion engine is caused to operate harder by controlling the injection of fuel into the internal combustion engine at least one, but usually multiple, combustion chambers, such as conventional cylinders, where the fuel injection into said combustion chamber is increased to accomplish the higher work. In the event that the braking force is applied during towing, a braking force is applied which is then balanced with. a corresponding positive work from the internal combustion engine where thus fuel injection to the internal combustion engine is forced. It is common in hybrid vehicles that regenerative braking is applied to towing, and such regenerative braking can be performed independently of the present invention. The difference between the present invention and such generative braking is that an additional braking force is applied, which is then counteracted by work from the internal combustion engine, the total force contribution to the vehicle drive wheels from the present invention being substantially zero.

Thus, the invention enables the load of the internal combustion engine 101 to be increased at e.g. situations where f o r b r ä n n i n g s nio t o r n 1 01 a n. n a r s t .ex. h a d e a r b e t a t p å t o m g å. n q, or only with very little or no load, with the result that a faster heating is obtained. In the case of towing, the present invention entails that instead of the vehicle being driven with a trailing internal combustion engine, and thus shut off fuel injection, the vehicle is instead driven with an increased internal combustion engine load which. entails that fuel must be injected, ie. the electric machine applies a force that "forces" the need for fuel injection. At this point, the torque acting on the vehicle's wheel will still be what is expected of the vehicle's driver, par. when towing with a released accelerator pedal, normally the towing torque of the internal combustion engine plus any braking force, but where according to the invention an additional driving force is applied by the internal combustion engine taken up by the electric machine so that the effect of the invention does not affect the force with which the vehicle is driven. Thus, the internal combustion engine operates according to the present invention even in towing, despite the fact that no positive work is required from the internal combustion engine.

Thus, once the applied braking force has been applied in step 304, the process proceeds to step 305 to determine whether to apply the applied braking force. This can e.g. be arranged to be carried out after the braking force has been applied for a certain time. internal combustion engine temperature. The procedure can also e.g. be arranged to be interrupted when the load of the internal combustion engine 101, e.g. due to prevailing driving resistance, anyway. will exceed, the desired b.rom. skr of ten. As long as the braking force is to continue to be applied by the electric machine 110, the process remains in step 304 via step 305, where the braking force applied by the electric machine 110 can be adapted to other loads of the internal combustion engine 101 if necessary, so that a total desired load is obtained. The procedure can also e.g. be arranged to be interrupted if the function for limiting white smoke / exhaust emissions is switched off.

If it is determined in step 305 that the procedure is to be interrupted, the procedure is terminated in step 306.

When the electric machine 110 generates a driving force for propelling the vehicle 100, energy from the energy storage is consumed therefor. Conversely, when the electric machine 110 is used for braking, energy is absorbed instead, which is converted into electrical energy and generates an electric current that can be taken over. The generated electrical energy normally consists of an alternating voltage, as electrical machines of the type shown normally consist of alternating current machines. This alternating voltage can be rectified to a direct voltage by means of the power electronics 210 to. then stored in the energy storage 111 for subsequent use at e.g. generating a force for propelling the vehicle 100. The braking force generated by the electric machine 110 can thus be largely recovered by charging the energy storage 111, at least as long as it is receptive to charging.

The present invention thus provides a. method where a braking force can be applied, wherein the applied braking force is calculated with good accuracy, and wherein the energy consumed in the form of fuel for the internal combustion engine can to a large extent be recovered by the braking energy absorbed by the electric machine can be recycled in electrical form for t .ex. storage in the energy storage 111.

According to one embodiment, the application of a braking force is interrupted by utilizing the electric machine if the energy storage 111 cannot receive the current generated by the electric machine. According to one embodiment, only one braking force is applied by the electric machine 110, which means that the energy absorbed and converted into electricity can be stored in the energy storage. If the desired braking force of the de-electric machine 110 results in the generation of an electric current which cannot be handled by the energy storage 111, a 1.1 g t an embodiment of the exhaust brake 119 may be provided, in which case the vehicle. 100 is stationary, activated to. provide a total internal combustion engine braking force of the desired size.

According to one embodiment, however, the electrical energy generated by the electric machine 110 is used only partially, or not at all, for charging the energy storage 111. Instead, the energy is used (at least partially} for generating heat, and in particular for heating one or more vehicle components, i.e. the energy absorbed by the electric machine is first converted into electricity and then at least partially converted into heat, thus causing an additional heating in addition to the heating produced by the higher internal combustion engine load.

The ability to take up charge in energy storage of the type shown is often. strongly dependent on energy stored s temperature. If the temperature of the energy storage is very low, such as e.g. -10 ° C to -15 ° C or even colder, the ability of the energy storage 111 to absorb, charge may be very low or virtually non-existent. According to one embodiment, the braking energy converted into electricity is used to heat water via a radiator. This is illustrated in Fig. 2, where an electric current generated by the electric machine. 110 vid. application of a braking force and converted by the power electronics to the applicable voltage / frequency, is converted into heat via a radiator 211 which in turn heats liquid in a liquid-borne system. The heated liquid can be used to be caused by means of a circulation pump 213 to circulate through a cooling loop passing through the energy storage 111 to heat the energy storage 111 to a temperature which means that charge can be received to a greater extent. If the energy storage 111 is heated to the desired temperature, and / or cannot receive all or part of the electric current generated by the electric machine, heat can be vented away to the surroundings of the vehicle 100 via a radiator 214. A valve 212 can be used to selectively select whether the radiator fluid is to be circulated through the energy storage 111, the radiator 214 or both.

The radiator 211 can also be used to heat coolant in the internal combustion engine cooling system, e.g. to further accelerate the heating of the internal combustion engine and / or accelerate the heating of a passenger / passenger compartment.

The invention has been described above in connection with a parallel hybrid system. However, the invention is also applicable to other types of hybrid systems where an electric machine, directly or indirectly via e.g. the vehicle's drive wheel, can apply a braking force to an internal combustion engine.

In summary, the present invention is thus such that it increases the load of the internal combustion engine and thus also the work delivered by the internal combustion engine. Furthermore, the invention is such that it enables the internal combustion engine to deliver a positive work. This is achieved by compensating the braking force applied to the internal combustion engine according to the present invention with a corresponding fuel injection, so that the internal combustion engine is certainly forced to perform a positive work.

This is illustrated in Fig. 4, where the invention is exemplified for a situation where towing normally occurs. In the figure, the x-axis represents torque and the y-axis time, the zero line 405 represents a torque-relieved situation. When the internal combustion engine, by means of combustion- in the combustion chamber of the internal combustion engine, performs one. positive work, the torque delivered will be at least zero (at idle when only the internal losses of the internal combustion engine are overcome by the work performed, and exceed zero when a larger work than that is generated by the combustion. In the example shown, the vehicle is driven with one of the internal combustion engine delivered work corresponding to a torque M1 up to time TI, solid line 401. Via time TI, the torque delivered begins to decrease, eg due to the vehicle's driving resistance decreasing, eg because the vehicle is approaching a shut-off.

The present example relates to a situation where the vehicle reaches a shut-off, and moreover of such a nature that no driving force contribution is required from the internal combustion engine. Normally in such a situation, the torque the internal combustion engine needs to emit drops to zero, at time T3, dashed line 402, the internal combustion engine then being subjected to an internal combustion engine driving torque. This means that the vehicle can be accelerated even though no positive work is done by the internal combustion engine. At T4, the torque change flattens out, e.g. due to the vehicle being in a downhill slope with. constant slope.

The internal combustion engine is rotated via such a situation by the drive wheels, and fuel injection is switched off, ie. towing prevails. The negative need for propulsion means that the vehicle will be accelerated as long as this condition prevails. However, this is not normally desirable, which is why energy is often slowed down. In such situations, in hybrid vehicles, the electric machine (dotted line 403) can be used to absorb and recover some of the force applied from the drive wheels by regenerative braking. This is indicated by a dotted line 404. Such regenerative braking means that a part of the internal combustion engine driving force is absorbed by the electric machine, whereby this energy can be utilized. However, the part that the electric machine occupies during regenerative braking is still less than or at most equal to the internal combustion engine driving force applied by the drive wheels.

According to the present invention, at. application at. a situation of the type shown in Fig. 4, a higher force, dotted line 403, is applied by the electric machine than that applied if the present invention is not activated, whereby the internal combustion engine is simultaneously controlled to deliver a work compensating for the higher force applied. of the electric machine. Thus, the internal combustion engine will deliver a positive work corresponding to it. additional braking force applied by the electric machine. This is indicated by the solid line 401 which thus differs markedly from the dashed line 402. According to the present invention, in situations where the invention is applied, the internal combustion engine is thus able to perform a positive work even in situations where it is normally sluggish.

Claims (34)

A method of heating at least one vehicle component of a vehicle (100), said vehicle (100) comprising an internal combustion engine (101), and at least a first electric machine (110), said first electric machine (110) being arranged for selective application of a force to a shaft output from said internal combustion engine (101), characterized in that: - applying to said output shaft of said internal combustion engine (101) a first braking force by utilizing said first electric machine (110) to raise it by said internal combustion engine (101). - determining whether the total load of the internal combustion engine (101) from said at least one first electric machine (110) together with the load from the drive wheels of the vehicle (100) is less than a first load, said first braking force being applied only as long as the internal combustion engine (101) total load from said at least one first electric machine (110) together with load from the drive wheels of the vehicle (100) is less than said first load. The method of claim 1, further comprising applying said first braking force by utilizing said first electric machine (110) to increase the work performed by combustion in said internal combustion engine. A method according to claim 1 or 2, further comprising, in response to said first braking force, increasing the amount of fuel supplied to said internal combustion engine. A method according to any one of claims 1-3, further comprising applying said first braking force to said output shaft in a situation when fuel is already being supplied to said internal combustion engine. A method according to any one of claims 1-4, wherein said internal combustion engine comprises at least one internal combustion chamber, and wherein the method further comprises applying said first braking force to said output shaft in a situation when fuel is supplied to said at least one internal combustion chamber. A method according to any one of claims 1-5, further comprising: - raising the work delivered by said internal combustion engine with a work corresponding to said first braking force. A method according to any one of claims 1-6, further comprising: - raising the work emitted by said internal combustion engine with a work corresponding to said first braking force so that the driving force acting on the vehicle's drive wheel consists essentially of a driving force requested on the vehicle's drive wheel. A method according to claim 7, wherein said driving force requested on the drive wheel of the vehicle constitutes a driving force requested by the driver of the vehicle. A method according to any one of claims 1-8, further comprising determining whether a temperature (Tmotor) of said internal combustion engine (101) is below a first temperature (Tmo tonimi) t and - by said electric machine applying said first braking force only if said first temperature (Tmotor) falls below a limit value (Tmot0riimi) • A method according to any one of claims 1-9, further comprising: - determining a representation of a temperature (up to g) for an environment of said vehicle (100), and - applying said first braking force to said shaft out of said internal combustion engine only if said ambient temperature (up to g) is less than a first temperature limit value. A method according to any one of the preceding claims, further comprising determining whether said internal combustion engine (101) has been started, and applying said first braking force to said shaft of said internal combustion engine (101) within a first time (ti) from said internal combustion engine ( 101) has been started. A method according to any one of the preceding claims, wherein said first braking force constitutes an internal combustion engine braking torque in the range of 10 Nm - 500 Nm. A method according to any one of the preceding claims, wherein said first braking force constitutes a braking force of such a magnitude that the total torque braking towards said output shaft amounts to a torque in the range 10 Nm - 500 Nm. A method according to any one of the preceding claims, further comprising applying said first braking force to said output shaft of said internal combustion engine (101) when the braking force acting on said output shaft in addition to said first braking force is less than a limit value. A method according to any one of the preceding claims, wherein said first braking force is applied only when said vehicle (100) is stationary. A method according to claim 15, wherein said first braking force is applied only when a parking brake is applied. A method according to any one of the preceding claims, wherein said first braking force is applied only when the speed of the vehicle (100) is less than a first speed. A method according to any one of the preceding claims, further comprising, when said first braking force is applied to said output shaft of said internal combustion engine (101): - determining a second representation of a temperature of said internal combustion engine (101), and - interrupting application of said first force when said temperature exceeds a second limit value. A method according to any preceding claim, further comprising applying said first force only when the exhaust emission limiting function of said vehicle (100) is activated. A method according to claim 19, wherein said function for limiting exhaust emissions constitutes a function for limiting white smoke emissions. A method according to any one of the preceding claims, further comprising interrupting the application of said first braking force when the energy absorbed by said electric machine (110) cannot be stored in an energy storage (111) arranged at said vehicle (100). A method according to any one of the preceding claims, further comprising, when the energy absorbed by said electric machine (110) cannot be stored in an energy storage (111) arranged at said vehicle (100), or when the desired internal combustion engine braking force can not be applied by means of said electric machine (110), activate an exhaust braking system present at said vehicle (100). A method according to any one of the preceding claims, wherein energy absorbed by said electric machine (110) upon application of said first force is primarily stored in an energy storage arranged at said vehicle. A method according to any one of the preceding claims, further comprising, when said electric machine (110) applying said first braking force: - converting the energy absorbed by said electric machine (110) upon application of said braking force at least partially to heat. The method of claim 24, wherein said heat-converted absorbed energy is used to heat any of the group: energy storage at said vehicle; a passenger compartment at said vehicle; coolant in a coolant system at said vehicle. A method according to any one of the preceding claims, wherein said electric machine (110) is selectively connectable to said output shaft of said internal combustion engine (101), said first force being applied to said output shaft only when said electric machine is connected to said output shaft. A method according to any one of the preceding claims, wherein said heating of at least one vehicle component consists of heating at least one of the group: - internal combustion engine (101); - energy storage (111). A method according to any one of the preceding claims, wherein said at least one vehicle component is at least one of said internal combustion engine. A computer program comprising program code, which when said program code is executed in a computer causes said computer to perform the method according to any one of claims 1-28. A computer program product comprising a computer readable medium and a computer program according to claim 29, wherein said computer program is included in said computer readable medium. A system for heating at least one vehicle component of a vehicle (100), said vehicle (100) comprising an internal combustion engine (101), and at least a first electric machine (110), said first electric machine (110) being arranged for selective application of a force to a shaft output from said internal combustion engine (101), characterized in that: - the system comprises means for applying to said output shaft of said internal combustion engine (101) a first braking force by utilizing said first electric machine (110), and - means for determining whether the total load of the internal combustion engine (101) from said at least one first electric machine (110) together with the load from the drive wheels of the vehicle (100) is less than a first load, and - means for applying said first braking force only as long as the internal combustion engine (101). ) total load from said at least one first electric machine (110) together with load from the drive wheels of the vehicle (100) is less than said first loading. The system of claim 31, wherein said electric machine is disposed between said internal combustion engine and a gearbox. A system according to claim 31 or 32, wherein said internal combustion engine is arranged so that its output shaft is interconnectable with the drive wheels of the vehicle for applying a force to said drive wheels. Vehicle, characterized in that it comprises a system according to any one of claims 31-33.