JP2008128245A - Changing method of operating mode of internal combustion engine in vehicle and control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce degradation in ride comfort, particularly for degradation in ride comfort caused by torque gradient, by changing of operating modes of an internal combustion engine. <P>SOLUTION: In a changing method of the operating modes (I, II) of an internal combustion engine in a vehicle having a drive system including a transmission with variable transmission ratio, change between the operating modes (I, II) is performed simultaneously with change in transmission ratio of the transmission. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for switching an operation mode of an in-vehicle internal combustion engine having a drive system equipped with a transmission having a variable gear ratio, and an internal combustion engine device, particularly a control device, and a computer program.

  In-vehicle internal combustion engines today are widely used intake pipe injection and direct injection Otto cycle engines and direct injection diesel engines. In this case, various combustion methods are known, such as high compression in homogeneous diesel cycle combustion (HCCI) and Otto cycle engines, in addition to homogeneous combustion and stratified combustion methods in Otto cycle engines. Combustion (CAI). Similarly, it is known to perform cylinder shutoff of individual cylinders. In all these operating modes, it is a disadvantage that they are not possible at all operating points of the internal combustion engine. Therefore, the driving mode must be switched during driving, which in some cases can worsen the ride comfort, for example in the form of a torque gradient. Similarly, it is known to drive vehicles with different fuels, such as natural gas or gasoline. In this case, switching between fuels may occur during driving, which may similarly generate a torque gradient.

  In switching operation modes of an internal combustion engine, it is an object of the present invention to reduce deterioration in riding comfort, particularly deterioration in riding comfort caused by a torque gradient.

  This problem is solved by the method, the device and the computer program according to the independent claims. This problem is particularly the method of switching the operation mode of the internal combustion engine in the vehicle having a drive system equipped with a transmission having a variable gear ratio. In this case, the switching of the operation mode is performed simultaneously with the change of the transmission gear ratio. This is solved by a method for switching the operation mode of the internal combustion engine in the vehicle. The gear ratio change of the transmission is, for example, a gear ratio change in a continuously variable transmission such as a gear change or a CVT in a manual switching transmission, an automatic switching transmission, and a transmission automatic device. Here, “simultaneously” is understood to mean that the operation mode is switched during the switching process or during the switching of the transmission gear ratio. Since the change of gear ratio is associated with a torque jump or at least one torque gradient, no additional torque gradient due to switching of the operating mode is further sensed.

  In the operation of the internal combustion engine in the specific region of the characteristic curve group, it is preferable that the operation mode is switched immediately when the transmission gear ratio is changed. When the internal combustion engine is operated within a specific region of the characteristic curve group, it should be assumed that the switching of the operation mode requires a change in the transmission gear ratio. This switching is postponed or executed immediately when a transmission gear ratio change is made. The switching of the operating mode that is approaching is detected based on the actual operating mode point of the internal combustion engine in the characteristic curve group and the change gradient of the operating state in the characteristic curve group. It is preferable to be performed when is changed. The “operation mode change gradient” is understood as the moving direction and moving amount of the operating point in the characteristic curve group. The characteristic curve group is preferably a torque characteristic curve group related to the rotational speed of the internal combustion engine. It is preferable that the switching of the operation mode is performed during the gear switching in the switching transmission. In this case, it is preferable that the operation mode is switched when the clutch in the drive system between the internal combustion engine and the transmission is at least partially opened in the transmission. The switching of the operation mode in the double clutch transmission with two clutches is preferably performed when both clutches are in a slipping state during the gear change. It is preferable that the operation mode switching in the automatic transmission apparatus including the converter direct coupling clutch is performed when the converter direct coupling clutch is open.

  The problem described at the beginning is a method for switching an operation mode of an in-vehicle internal combustion engine having a drive system provided with a clutch device for at least partly separating torque transmission between the internal combustion engine and the drive system. This is also solved by a method for switching the operating mode of an in-vehicle internal combustion engine in which the clutch device is at least partially opened, thereby creating a slip in torque transmission between the internal combustion engine and the drive train. The clutch device is preferably a clutch in the vehicle drive system between the internal combustion engine and the transmission, in which case the clutch is brought into a sliding state by being partially released during switching of the operation mode. In another preferred embodiment, the clutch device may include two clutches in the vehicle drive train between the internal combustion engine and the double clutch transmission, in which case both clutches are switched between operating modes. It is made to slide by being partially opened. Similarly, the clutch device may be a converter direct-coupled clutch of an automatic transmission apparatus in a vehicle drive system between the internal combustion engine and the drive system. In this case, the converter direct-coupled clutch is opened during switching of the operation mode.

  The problem described at the beginning is that in an internal combustion engine device having means provided for switching the operation mode of an in-vehicle internal combustion engine having a drive system equipped with a transmission having a variable gear ratio, particularly a control device, In this case, the problem is also solved by a device for an internal combustion engine, in particular a control device, in which the switching of the operating mode takes place simultaneously with the change of the transmission gear ratio.

  An object described at the outset is an internal combustion engine having means provided for switching the operation mode of an in-vehicle internal combustion engine having a drive system having a clutch device for at least partially separating torque transmission between the internal combustion engine and the drive system. In an engine device, in particular, in a control device, an internal combustion engine is characterized in that at least a part of the clutch device is opened when switching the operation mode, whereby slip is formed in torque transmission between the internal combustion engine and the drive system. It can also be solved by a service device, in particular a control device.

  The problem described at the outset is also solved by a computer program having program code for performing all the steps described in the method according to the invention when the program is executed in a computer.

  FIG. 1 shows an example of an engine characteristic curve group of an internal combustion engine, a so-called Muschel diagram. The torque T [Nm] of the internal combustion engine is shown with respect to the rotational speed n [1 / min (1 / min)]. It is assumed that the internal combustion engine is arranged in a motor vehicle, in which case the internal combustion engine serves to drive the motor vehicle. The internal combustion engine is a part of an automobile drive system, and the drive system includes, in addition to the internal combustion engine, a speed reducer having a variable reduction ratio for driving the drive wheels. Even if the reduction gear is, for example, a manual switching transmission in which a clutch that can be switched between the internal combustion engine and the switching transmission is disposed, automatic switching in which a clutch is disposed between the internal combustion engine and the switching transmission is similarly performed. Even if it is a transmission, the torque converter can be directly connected by a torque converter direct-coupled clutch, and it is a transmission automatic device having a torque converter and a hydraulic switching gear, or a so-called double-clutch transmission having two clutches In this case, the double clutch transmission includes two independent transmission systems, which can be alternately coupled to the internal combustion engine by respective clutches attached to the transmission system. Similarly, the transmission may be a transmission (CVT) with a continuously variable transmission ratio. All the above transmissions and clutch devices are known per se and are therefore not described in detail here.

  The internal combustion engine is not only a diesel engine but also an Otto cycle engine. Various operating modes are known not only in diesel engines but also in Otto cycle engines. On the other hand, especially in the case of Otto cycle engines, various operating modes are known for fuel injection and combustion, for example homogeneous or stratified combustion methods or combinations thereof, homogeneous diesel cycle combustion (HCCI) High compression Otto cycle engine combustion (CAI) and the like are known. In operation of an internal combustion engine, switching between these operating modes is possible and this switching is generally related to the torque gradient. Similarly, it is known, for example, to shut off individual cylinders of an internal combustion engine in a partial load region and to turn on individual cylinders again when there is a corresponding high torque demand (cylinder shut-off). Again, a torque jump occurs when the cylinder is turned on or off. Furthermore, it is known to operate internal combustion engines with various fuels, for example selectively with gasoline or natural gas. In this case, when the combustion is switched from one fuel to the other fuel, a torque jump occurs similarly.

Here, the switching between the different operation modes is performed at the time when the gear ratio change, which is the gear switching, is performed in the switching transmission or the automatic transmission device.
If the change of gear ratio does not coincide with the change of operation mode, for example, the converter direct coupling clutch is released in the automatic transmission device, or the clutch is properly slipped in the automatic transmission transmission or the double clutch transmission. Thus, the drive system may be set in the “flexible state”.

These are shown in the example of FIG. 1 with a characteristic curve group K of engine torque T with respect to the rotational speed n of the internal combustion engine. The full load curve VK shows the boundaries of the available high power area. A plurality of curves BF indicate the steady operation region. A chain line indicated by T (P = konst.) Represents a constant output rotational speed / torque. The curves with 275, 300, 325, 350, 400, 450, 500 show the same specific consumption b _e = constant line with respect to output. At an engine torque of about 65 [Nm] and a maximum rotational speed of about 4,700 [1 / min], the operation mode of the internal combustion engine is switched. This operation mode switching is indicated by a solid line A. That is, two regions having different operation modes exist in the characteristic curve group, while the operation mode I at the engine torque> 65 [Nm] or the rotation speed> 4,700 [1 / min] and the engine at the other side. An operation mode II with torque <65 [Nm] and rotational speed <4,700 [1 / min] exists. In the characteristic curve group of FIG. 1, when the line A is exceeded due to a change in rotational speed or a change in torque, the operation mode is switched. Within the characteristic curve group, lines G1, G2, G3, G4 and G5 are respectively shown for different gears of the transmission, and a chain line P is shown for the same output. The gear switching shifts the operating point along the line P having the same output to the respective intersections with the lines for the respective gears of the transmission, for example from point 2 to point 4 in switching from 4 gears to 5 gears. Shift to. In switching from the point 2 to the point 4, the line P intersects with the line A, so the operation mode needs to be switched. Here, this switching of the operation mode is performed simultaneously with the gear switching from the 4th gear to the 5th gear, that is, from the point 2 to the point 4. Similarly, the operation mode switching is also performed in reverse, that is, for example, switching from 5 gears to 4 gears is performed similarly from point 4 to point 2 in the example of FIG.

  The characteristic curve group region for each operation mode I or II is not only performed when the line A is exceeded, but also when the operation point enters the elongated region KAB surrounded by the line A and the dotted line B. Is called. For example, when switching from 3 gears at the operating point 1 to 4 gears at the operating point 2 is performed, the operating mode II is not surely switched to the operating mode I, but the operating point reaches the elongated area KAB. Yes. Since the mode is switched from the operation mode II to the narrow area KAB, the operation mode is switched to the operation mode I simultaneously with the switching from the 3rd gear to the 4th gear. Conversely, for example, when the operating point 4 in the 5th gear is switched to the operating point 2 in the 4th gear, the operating mode I is switched to the elongated region KAB. Done.

  In the automatic switching transmission (ASG), the switching time for the operation mode coincides with the gear switching. Since the gear switching is electronically controlled, this information is transmitted to the control device, whereby the operation mode switching can be synchronized with the gear switching. In the automatic transmission apparatus having a converter, in order to use the buffer of the fluid torque converter, the operation mode is switched in a phase where the converter direct coupling clutch is released. In a double clutch transmission, the switching point is shifted so that the switching point of the operation mode is provided within the phase in which both clutches are in a slipping state or the operation mode switching phase of the internal combustion engine. . In this case as well, information regarding the switching point is always supplied to the control device via the electronic circuit. In the manual switching transmission, the operation mode is switched when the clutch is released during gear switching. The release of the clutch may be determined, for example, by a switch attached to the clutch, or may be determined, for example, via the accelerator pedal position or the actual output torque during the switching process.

  FIG. 2 shows an embodiment of control for the automatic transmission. In this case, the automatic transmission may be an automatic shift transmission as well as an automatic switching transmission. Based on the driver's desire (desired torque WM) and / or the vehicle speed v, the operation mode B of the internal combustion engine M is set in the operation mode adjusting device KO. The transmission AG transmits the actual engagement gear EG to the operation mode adjustment device KO. Here, when the operation mode is switched, this is executed simultaneously with the operation of the transmission AG, for example, the opening of the converter direct coupling clutch, the switching process S in the automatic switching transmission, the gear ratio change in the continuously variable transmission, It is executed simultaneously with the overlap switching in the double clutch transmission. Switching from the narrower region, i.e., operation mode II of FIG. 1, to the wider operation region, i.e., operation mode I of FIG. 1, must take place at the latest at the operation mode boundary, i.e. line A of FIG. The reverse switching from the operation mode having the wider operation region to the operation mode having the narrower operation region, that is, the switching from the operation mode I to the operation mode II in FIG. 1 is performed in the corresponding reverse direction. .

  An example of control in a manual transmission is shown in FIG. In this case as well, similarly, the operation mode adjustment device KO determines whether or not the operation mode must be switched based on the vehicle speed v, the accelerator pedal position (desired torque WM), and the like. Only when the clutch is disengaged and this is transmitted to the operation mode adjusting device KO by the clutch state K, the switching takes place.

It is an engine characteristic curve group of an internal combustion engine. 1 is a schematic diagram of control according to the present invention in an automatic transmission. 2 is a schematic diagram of the control according to the present invention in a manual switching transmission.

Explanation of symbols

A Boundary line of operation mode (boundary line of narrow area)
AG automatic transmission B (Fig. 1) elongate region of the boundary line B (FIG. 2), I, II operation mode BF steady operation region b _e ratio consumption EG actually turned gear G (FIG. 1) gradient G (FIG. 3) Manual Switching transmission G1, G2, G3, G4, G5 Gear K (Fig. 1) Characteristic curve group K (Fig. 3) Clutch state KAB Specific region (elongated region)
KO operation mode adjustment device M internal combustion engine n rotational speed P output S switching process T torque v vehicle speed VK full load curve WM desired torque

Claims (15)

In a method for switching an operation mode (I, II) of an internal combustion engine in a vehicle having a drive system provided with a transmission having a variable gear ratio,
A method for switching an operation mode of an in-vehicle internal combustion engine, wherein the operation mode (I, II) is switched simultaneously with a change in a transmission gear ratio.   In the operation of the internal combustion engine in the specific region (KAB) of the characteristic curve group (K), the operation mode (I, II) is switched immediately when the transmission gear ratio is changed. The method of claim 1 wherein:   The switching of the operation mode approaching is based on the actual operation mode (I, II) point of the internal combustion engine in the characteristic curve group (K) and the change gradient (G) of the operation state in the characteristic curve group (K). The method according to claim 1 or 2, characterized in that the operation mode (I, II) is switched when the transmission gear ratio changes.   4. The method according to claim 1, wherein the characteristic curve group (K) is a characteristic curve group (K) of torque (T) relating to the rotational speed (n).   5. The method as claimed in claim 1, wherein the switching of the operating modes (I, II) is performed during gear switching in the switching transmission.   6. Method according to claim 5, characterized in that the switching of the operating modes (I, II) takes place in the switching transmission when the clutch in the drive train between the internal combustion engine and the transmission is at least partially open. .   Switching between operating modes (I, II) in a double clutch transmission with two clutches is performed when both clutches are in a slipping state during gear switching. 5. Either method.   6. The method according to claim 1, wherein the switching of the operation mode (I, II) in the automatic transmission device having a converter direct coupling clutch is performed when the converter direct coupling clutch is open. In a method for switching an operation mode (I, II) of an in-vehicle internal combustion engine having a drive system provided with a clutch device for at least partially separating torque transmission between the internal combustion engine and the drive system,
In the switching of the operation modes (I, II), the clutch device is at least partially opened, thereby causing slip in the torque transmission between the internal combustion engine and the drive system. Switching method.   10. The method of claim 9, wherein the clutch device is a clutch in a vehicle drive system between the internal combustion engine and the transmission, and the clutch is made to slide by being partially released during switching of the operation mode. .   The clutch device is two clutches in a vehicle drive system between an internal combustion engine and a double clutch transmission, and both clutches are brought into a sliding state by being partially released during operation mode switching. The method of claim 9.   10. The method according to claim 9, wherein the clutch device is a converter direct-coupled clutch of an automatic transmission in a vehicle drive system between the internal combustion engine and the drive system, and the converter direct-coupled clutch is released during switching of the operation mode. In a control device for an internal combustion engine comprising means provided for switching an operation mode (I, II) of an in-vehicle internal combustion engine having a drive system equipped with a transmission having a variable gear ratio,
A control device for an internal combustion engine, characterized in that the switching of the operation modes (I, II) is performed simultaneously with the change of the transmission gear ratio. Internal combustion engine comprising means provided for switching the operating mode (I, II) of an in-vehicle internal combustion engine having a drive system with a clutch system for at least partly separating torque transmission between the internal combustion engine and the drive system In an engine control device,
A control device for an internal combustion engine, wherein at least part of the clutch device is disengaged in switching of the operation modes (I, II), whereby slip is formed in torque transmission between the internal combustion engine and the drive system.   Computer program having program code for executing all the steps of the method according to any of claims 1 to 12, when the program is executed in a computer.

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