JP2011085140A - Method for driving automobile mounting internal combustion engine and mechanical power transmission thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for driving an automobile with a manual transmission, capable of being driven at low-fuel consumption and reduced in toxic emission. <P>SOLUTION: The method for driving an automobile mounted with an internal combustion engine and a mechanical power transmission, and having a means for measuring a traveling speed and an engine speed. In the method, a cutoff speed (n<SB>abr</SB>) of the internal combustion engine at a gear stage (i<SB>n</SB>) which is actually shifted is defined so that an output (p<SB>akt</SB>) of the internal combustion engine requested from a driver can generate the same traveling speed of the automobile at the gear stage (i<SB>n+1</SB>) which is the second highest gear stage. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a method for driving an automobile equipped with a manual transmission.

  A new internal combustion engine control device mounted on an automobile stores, in particular, a characteristic map representing the relationship between engine speed and output. The maximum output of the internal combustion engine is achieved when the accelerator pedal is fully depressed. When the internal combustion engine is operating in the partial load region, the accelerator pedal is in a position between 0% and 100%. During idling or coasting of the internal combustion engine, the accelerator pedal is not depressed and the accelerator pedal position is equal to 0%.

  In the case of many supercharged internal combustion engines such as those employed in trucks, the output of the internal combustion engine is constant over a certain range of rotational speed.

  In the case of a large truck having a fuel consumption rate of approximately 30 liters per 100 km of travel distance, the fuel cost is integrated over the years of use of the truck, and if the estimated travel distance is 1.5 million km, the amount is approximately 500,000 euros To reach. As this figure has already revealed, lowering the fuel consumption rate not only reduces the environmental burden, but also results in cost savings that cannot be ignored.

The present invention provides a driving method for an automobile equipped with a manual transmission, in which the cut-off speed of the internal combustion engine is determined by the output required by the driver, thereby enabling driving with low fuel consumption and low harmful emissions. To do.

  In the method according to the invention for the operation of a motor vehicle equipped with an internal combustion engine and a mechanical power transmission device and equipped with means for measuring the running speed and the engine speed, the gear stages actually included The internal combustion engine cut-off speed is determined in such a way that the output of the internal combustion engine required by the driver is generated at the next largest gear stage and at the same running speed of the vehicle.

  Therefore, according to the present invention, a variable cutoff speed is set according to the drive output and travel speed required at that time by the control device, and the cutoff speed is set to the next highest gear stage. Switching to is possible without a reduction in the vehicle output, and when the vehicle driver wants to increase the running speed, it is determined that the driver is required to switch to the next higher gear stage. Thereby, fuel consumption and emission of harmful substances are reduced. Further, wear of the internal combustion engine is reduced due to the decrease in the engine speed, which is expressed as a low maintenance cost.

The method according to the invention does not require any additional hardware components. This is because a speedometer and a rotational speed meter for measuring the rotational speed of the internal combustion engine are provided in any automobile anyway. Knowing the gear ratios of the various gear steps of the mechanical power transmission device, from the ratio of the running speed and the engine speed, because obtained even gear stage i _n that are placed, are actually put gear There is no need for any special sensor or detector in the manual transmission to detect the stage. Of course, for example in the case of an automatic transmission and when the gear stage actually shifted there is measured, for example, via a contact switch, the signal can also be used for measuring the gear stage being shifted. .

  Furthermore, every new internal combustion engine installed in an automobile is provided with an engine control device and a number of characteristic maps. At least one of these characteristic maps stores the relationship between the engine speed, the accelerator pedal position, and the output of the internal combustion engine. Therefore, from the rotational speed of the internal combustion engine and the torque demand of the driver, the output actually requested by the driver is read from the characteristic map, and the output is extracted with a higher gear and with a lower rotational speed of the internal combustion engine. It is possible to check whether or not In short, the method according to the invention does not require any additional information, for example sensors, and can therefore be carried out at low cost by suitable software even in already mass-produced controllers.

  The method according to the invention is economical and saves fuel without any loss in the driving performance of the vehicle, so that the average speed of the vehicle remains unchanged.

  However, when the aspect of reducing fuel consumption should be pushed out more strongly, the cut-off speed of the internal combustion engine can be set to the rated speed of the internal combustion engine. In this case, the rated rotational speed of the internal combustion engine is understood to be the rotational speed at which the internal combustion engine generates its maximum output. In the case of a characteristic curve in which the output is constant over one rotational speed region, the minimum rotational speed of the internal combustion engine that reaches the maximum output is regarded as the rated rotational speed.

  This method ensures that the output of the internal combustion engine increases as the rotational speed increases until the cutoff rotational speed is reached. The car driver then tries to get into the next higher gear stage by the method according to the invention, which is particularly important when the gear ratio opening is small and at the same time improving the efficiency of the internal combustion engine. Cause a slight decrease in output.

  In many driving cases, the vehicle can be run at the desired speed with this slight reduction in power, so significant fuel savings are realized without a reduction in travel speed. In some cases, due to a slight decrease in output when switching to the next higher gear stage, the speed of the vehicle is reduced, so that the driver of the vehicle can draw out the necessary drive output. There may be re-introduction to a lower gear stage. In such rare cases, the method according to the invention is accompanied by a certain comfort reduction, but this is not disadvantageous. This is because a driver who knows the method according to the present invention will stop downshifting and as a result he will drive economically with a noticeable reduction in fuel consumption with a slight reduction in driving speed. Because you can.

  The method according to the invention according to claim 1 is also useful when the driver of the motor vehicle drives the internal combustion engine in a partial load condition rather than in a full load condition. That is, for example, when the driver of an automobile has driven the accelerator pedal halfway in the 13th gear stage (accelerator pedal position = 50%) and is running for a relatively long time, the required output of the internal combustion engine is a larger gear stage. If it shifts to, it will be possible to pull out with a smaller number of revolutions.

According to the present invention, the output of the internal combustion engine that is actually requested by the driver is read from the characteristic map of the control device from the current rotational speed of the internal combustion engine and the position of the accelerator pedal, and the internal combustion engine at the next higher gear stage. It is checked whether the same engine output can be derived. If it can be extracted, the current rotational speed of the internal combustion engine under the gear stage that is actually shifted is defined as the cutoff rotational speed. This means that the driver can only increase his driving speed by shifting up to the next higher gear stage under this driving resistance, which leads to the desired shifting up. The When the accelerator pedal is depressed more strongly, the engine speed is temporarily increased and then the engine speed is reduced to the original cutoff speed. This process is also referred to as descending slope (Abrampen) in the context of the present invention.
In order to minimize the reduction in comfort associated with this reduction in the cut-off speed and to continue to allow stable driving, according to the invention, the engine speed is cut for a short time. It is thought that it may be larger than the off rotation speed. However, in another advantageous embodiment of the invention, the allowed deviation between the engine speed and the cutoff speed is reduced in a time-dependent manner. This makes it possible to exceed the cutoff rotation speed for several seconds. However, if the driver is operated at a rotational speed that is too high for a relatively long time, e.g. when climbing uphill, an allowance between the actual engine speed and the cut-off speed is allowed to some extent in the form of a ramp. The deviation is continuously reduced until the internal combustion engine is actually controlled and thereby the vehicle is at its original speed again. The car driver is therefore informed very quickly that if he wants to run faster, he must shift to the next higher gear stage. Thereby, the speed of the internal combustion engine is usually reduced below the cut-off speed, so that the car again reaches or exceeds the travel speed originally desired by the driver while simultaneously reducing fuel consumption. I can even do that. Of course, in extreme cases, the driver will be able to drive multiple gear stages until the internal combustion engine speed is lower than the internal combustion engine cut-off speed for a long time and a stable driving condition can be generated again. You may need to shift up.

  The method according to the present invention guides the driver to shift to the next higher gear stage in cases where more efficient operation of the internal combustion engine is possible, and thereby fuel consumption of the internal combustion engine, emission of harmful substances, And the above-mentioned positive effect with respect to wear is realized. Alternatively, or as an alternative, when the engine speed is greater than or equal to the cut-off speed, the internal combustion engine is actually controlled according to the cut-off speed, and at the same time optical and / or acoustic A warning signal can be issued. According to the invention, it is also possible to first generate an acoustic and / or optical signal in the first step and then to control the internal combustion engine after a short period of time, for example 2 seconds. . This allows the driver to always shift to a higher gear stage before the speed of the internal combustion engine is controlled. Thus, the advantages of the present invention can be achieved without a decrease in comfort.

  If the vehicle is equipped with an automatic transmission, automatically shifts to the next higher gear stage, i.e. without driver intervention, thereby ensuring optimal operation of the internal combustion engine and thus the vehicle Is also possible.

  Other advantages and preferred embodiments of the invention can be taken from the following drawings, the description and the claims. All Mercumals described in the drawings, their descriptions, and the claims can be essential to the present invention, either alone or in any combination thereof.

FIG. 1 shows a speed output curve in which the output of the internal combustion engine has a plateau (flat part in the graph). FIG. 2 shows a progress diagram of one embodiment of the method according to the invention. FIG. 3 shows a characteristic curve with a clear output peak.

  In FIG. 1, the rotation speed n [1 / min: rpm] of the internal combustion engine of the automobile is taken on the horizontal axis (X axis). The vehicle speed v [km / h] is taken on the left Y axis. In the present invention, since it is assumed that the automobile includes a mechanical power transmission device, a linear relationship is given between the traveling speed v and the rotational speed n of the internal combustion engine. These linear gradients depend on the gear ratio of the gear stage that is engaged. In this example, this relationship is shown for a gear stage from 11 to 16 and an overdrive in the form of the original line 11 to 16 and a single line named “Overdrive” in the original line. ing.

The Y axis on the right side of FIG. 1 shows the output [kW] of the internal combustion engine as the vertical axis. The maximum output p _max , i.e. the output of the internal combustion engine when the accelerator pedal is fully depressed, is indicated by a line 21 in the graph. This change in line 21 is horizontal in the region between the lower rotation speed n _u and the upper rotation speed n _o, and this horizontal portion is usually also called “plateau”. Within this speed range, the output of the internal combustion engine is constant. Such “plateau” shaped characteristic curves are often found, for example, in high-load internal combustion engines such as those mounted on trucks.

For example, in the case of an internal combustion engine in which the rotation speed is _nV1,16 at the 16th speed when the vehicle speed is v ₁ , as shown in FIG. 1, if the driver _{puts the} gear into the overdrive, the same output is more It can be generated even at a low rotational speed. The internal combustion engine can generate the maximum output p _max at the rotational speed generated at that time (this rotational speed is equal to the rotational speed _nu in this example).

Therefore, in order to guide the driver to shift to overdrive, according to the present invention, when the cut-off speed n _abr of the internal combustion engine is at the 16th speed, it is set to be the speed _nV1,16. ing. That is, the driver cannot accelerate beyond the speed v ₁ at the 16th speed. However, the driver generally wants to reach his driving target as quickly as possible, so if the driver wants to increase his driving speed, he can only shift up to overdrive. Thereby, the internal combustion engine is forced to operate at more advantageous operating points, thus reducing harmful substance emissions, fuel consumption, and wear. This is, when shifted to the overdrive, while at the same time vehicle can even exceed or whether to maintain the speed v _1, the fuel consumption, wear, and that harmful substances discharged are reduced due to the internal combustion engine I mean. In the graph of FIG. 1, this shift from 16th speed to overdrive is represented by a horizontal line 23.

The same is shifted to 15th gear to 16th gear under velocity v _2, or shift to 14th speed to 15th speed under speed v _3, true for so. Thus, the method of the present invention does not result in the reduction in travel speed desired by the driver, but merely provides the same travel output at lower speeds with less wear and less fuel consumption.

In order for the method according to the invention to have little effect on the running, the cut-off speed of the internal combustion engine at the 16th speed is set to the above-mentioned speed n only after a short “waiting time”. It is considered to lower it to _v1,16 . In the example of speed v ₁ , the car driver could first accelerate beyond speed v ₁ at 16th speed without shifting to overdrive. Even when the speed v ₁ of the car is a few seconds over at the 16 speed being shifted, the cutoff rotational speed of the internal combustion engine is lowered to the rotational speed n _V1,16, resulting, shifted by 16 speed The speed of the existing car is changed until the speed becomes v ₁ . However, the driver can avoid this speed change if shifting to overdrive. Thus, the control of the internal combustion engine according to the invention guides the driver to shift to the maximum possible gear stage and thereby save fuel.

The same is true for lower gear stages, lower travel speeds or partial load regions. Thus, for example when the automobile is running at a speed v ₂ at the 15-speed, internal combustion engine, the rotational speed n _V2,15 corresponding thereto. When the vehicle has and velocity v ₂ and climbing gained large load is equal to the permissible speed, when the allowable maximum speed v ₂ has finished climbing after a certain time remains the same, requires less drive output Assuming that the driver "relaxed" the accelerator pedal after the end of the climb, According to the present invention, the new was desired actually by the driver from the accelerator pedal position output determined and the internal combustion engine control device at the same time, for example, the rotational speed when put into overdrive, at a speed v ₂ of the motor vehicle It is possible to check whether the output necessary to run can be generated. In FIG. 1, this “check” is indicated by the fact that the output of the internal combustion engine at the rotation speed v _{2, OD} is obtained (see the intersection of the broken line and the line 21).

If this is the case, the speed _nv2,15 is defined as the new cut-off speed, so that after a relatively short waiting time, it shifts to a higher gear stage, ie the 16th stage or overdrive. Without it, the car can no longer accelerate. For this reason, the driver is guided to shift to overdrive, and as a result, the vehicle can again overspeed v ₂ even though the speed of the internal combustion engine decreases. Thus, the desired driver wants to maintain the speed v ₂ is realized, efficient operation of and simultaneously the internal combustion engine is achieved.

FIG. 2 shows this case, which shows how the method according to the invention works when the speed of the internal combustion engine is above the short cut-off speed _nabr. Has been. In FIG. 2, time t is taken as a time axis. In the upper graph, the desired running speed v is taken. This is indicated by line 25.
In the lower graph, the position of the accelerator pedal is standardized and entered (see line 27). During the time interval from t = 0 to t = t ₁ , the full output of the internal combustion engine is generated, which is represented by 100% accelerator pedal position. Thus, for example, if the output required by the driver is reduced at time t ₁ even though the traveling speed v ₂ remains the same, and the driver loosens the accelerator pedal, for example, from time t ₁ , the accelerator pedal position is For example, it is about 50%. From this changed accelerator pedal position, the control device determines the output of the internal combustion engine necessary for t> t _{1 while} the rotational speed of the internal combustion engine remains the same. In the case of this example, this required output can be generated even at a lower speed of the internal combustion engine if it is shifted to a larger gear stage, and at the same time, the traveling speed v ₂ can be maintained. Therefore, in order to induce the driver to shift up as soon as possible, the value of the rotational speed is lowered to the n _V2,15 at t _1.

According to the invention, this new cutoff speed _nv2,15 can be exceeded during a short waiting time. This can be seen from the line 29 indicating the cut-off speed. The bending of line 29 at time t ₁ is caused by a change in accelerator pedal position.

In order to prevent the internal combustion engine from being immediately controlled to the new, lower cut-off speed _{nv2, abr} at the time t ₁ + Δt, according to the invention, the actual engine speed and the cut-off speed are determined. Is allowed for a limited time interval. Further, it is considered that the rotational speed deviation Δn is reduced with time. This is shown in the lower graph of FIG.

Thus, by the time t _2, since the internal combustion engine is controlled to the cutoff rotational speed n _{v2, abr,} drivers are induced to shift to a higher gear stage.

In FIG. 3, the method according to the invention is illustrated using a modified characteristic curve p _max of the internal combustion engine. In the case of this internal combustion engine, the output characteristic curve 21 takes a clear maximum value p _max at the rotational speed n _nenn . Here, according to the present invention, since the output characteristic curve 21 is symmetrical with respect to the rated speed n _nnn , the cut-off speed is shifted up to the next higher gear stage under a slightly higher speed n. It is possible to determine that the same output can be obtained again. For example, if the driver is speed n ₁₅ of the internal combustion engine are run at the 15 speed _{(n 15} is greater than the rated rotational speed n _n), the same output is lower rotational speed of the 16-speed n ₁₆ Can also be obtained. The rotational speed n ₁₆ is lower than the rated rotational speed n _nenn because the output characteristic curve 21 is substantially symmetrical with respect to the rated rotational speed.

From this, the rotation speed n ₁₅ is the optimum shift point for shifting to the next largest gear stage, that is, the 16th speed. In other words, the internal combustion engine as soon as the over this or reaches the number of revolutions n _15, the rotational speed n ₁₅ is determined as a new cut-off rotational speed. This also guides the driver to shift to a higher gear stage. The same is true for the other lower gear stages. The distance between the speeds n ₁₅ and n ₁₆ or between the shift points is finally determined by the opening of the gear between the gear stages 15 and 16.

FIG. 3 shows a further enhanced fuel saving variant of the method according to the invention. _{Whenever the} internal combustion engine reaches the rated speed n _nenn , the engine speed is limited to the rated speed n _nenn after being allowed to exceed the rated speed n _nnn for a short time. This means that if the driver wants to accelerate further, the driver will again need to shift to the next higher gear stage, even though the resulting output is slightly smaller. I mean. The rotational speed changes resulting from this method are also indicated in FIG. 3 by reference symbols Δn _15,16 or Δn _14,15, etc.

11 11th speed 12 12th speed 13 13th speed 14 14th speed 15 15th speed 16 16th speed 21 Maximum output 23 Horizontal line 25 representing shift from 16th speed to overdrive Desired speed 27 Accelerator pedal Position 29 Cut-off speed Δn Speed deviation between actual engine speed and cut-off speed n Engine speed [1 / min = rpm]
n _abr cut-off speed n _nnn rated speed n _o upper speed n _u lower speed n _v1,16 traveling at 16th speed at speed v ₁ n _v2, traveling _{at OD} overdrive at speed v ₂ n _v2,15 15th electric car traveling at speed v ₂

Claims (12)

In a driving method of an automobile equipped with an internal combustion engine and a mechanical power transmission device and provided with means for measuring a traveling speed and an engine speed,
The cut-off speed (n _abr ) of the internal combustion engine under the gear stage (i _n ) that is actually shifted is the next higher gear with the output (p _akt ) of the internal combustion engine required by the driver. A method of driving a vehicle, characterized in that it is determined in step (i _{n + 1} ) and so that the same travel speed of the vehicle can be generated. In a driving method of an automobile equipped with an internal combustion engine and a mechanical power transmission device, and having means for measuring a running speed (v) and an engine speed (n),
A method for driving an automobile, characterized in that the cut-off speed (n _abr ) of the internal combustion engine is equal to the rated speed (n _Nenn ) of the internal combustion engine. The operating method according to claim 1 or 2, characterized in that the engine speed (n) can be larger than the cut-off speed (n _abr ) for a short time. _{4. The} allowable deviation (Δn = n _mot −n _abr ) between the engine speed (n) and the cut-off speed (n _abr ) is reduced with time. The driving method described. The allowed deviation (Δn = n _mot −n _abr ) between the engine speed (n) and the cut-off speed (n _abr ) is reduced by 100 / min per second. Item 4. The driving method according to Item 3. When the engine speed (n) is greater than or equal to the cut-off speed (n _abr ) (Δn > 0), at least one of an optical signal and an acoustic signal is generated. The driving method according to any one of claims 1 to 5. The operating method according to any one of claims 1 to 6, wherein the internal combustion engine is controlled so that the engine speed (n) is smaller than or equal to the cutoff speed (n _abr ). When the engine speed (n) is greater than or equal to the cut-off speed (n _abr ) (Δn > 0) and the vehicle is equipped with an automatic transmission, it is shifted to the next higher gear stage (i _{n + 1} ). The operation method according to any one of claims 1 to 7, characterized in that:   9. The power transmission device according to claim 1, wherein the mechanical power transmission device is put into any gear stage, and is performed only when the clutch is not operated and the accelerator pedal is operated. The driving method described.   9. A control device for operating an internal combustion engine, wherein the control device operates according to the operating method according to claim 1.   A computer program which is executed by a computer and operates according to the operation method according to any one of claims 1 to 8.   The computer program according to claim 10, wherein the computer program can be stored in a storage medium.

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