JP2008128149A - Engine control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine control device for a vehicle for conducting required minimum engine torque restriction. <P>SOLUTION: With a fatigue degree calculation means 106 for calculating a fatigue degree of its driving force transmission device 8 based on torque to be input to the driving force transmission device 8 from a predetermined relation and an engine torque restriction means 108 for restricting output torque of the engine 26 according to the fatigue degree calculated by the fatigue degree calculation means 106, the engine control device for the vehicle can restrict the engine torque according to a remaining life of the driving force transmission device 8 in a range of avoiding excess. Thus, it is possible to provide the engine control device for the vehicle for conducting required minimum engine torque restriction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle engine control apparatus for controlling an engine that generates a driving force of a vehicle, and more particularly to an improvement for optimizing the output torque limit.

  A vehicle engine control device for controlling an engine that generates a driving force of a vehicle is used in various vehicles. As an example of such a vehicle engine control device, there has been proposed one that limits the output torque of the engine for the purpose of improving the durability of the drive system. For example, the regulator of the boost pressure output described in patent document 1 is it. According to this technology, the output torque of the engine (torque converter) is restricted to the input limit value of the transmission, thereby preventing the operation in the excessive torque state and generating a state of reducing the durability of the engine. It can be avoided.

Japanese Patent Laid-Open No. 5-187241 Japanese Patent No. 2762554

  However, according to the prior art, the output torque of the engine is uniformly limited to the input torque limit value of the driving force transmission device (a predetermined value based on the transmission specifications). Even if the strength of the force transmission device is sufficient, torque exceeding the input torque limit value cannot be input, and there is a problem that the engine torque is excessively limited. For this reason, there has been a demand for the development of a vehicular engine control device that performs sufficient engine torque limitation when necessary.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicle engine control apparatus that performs sufficient engine torque limitation as necessary.

  In order to achieve such an object, the gist of the present invention includes an engine that generates a driving force, and a driving force transmission device that transmits the driving force output from the engine to driving wheels. A vehicle engine control device for controlling the engine in a vehicle, wherein a degree of fatigue of the driving force transmission device is calculated based on a torque input to the driving force transmission device from a predetermined relationship. It has fatigue degree calculating means and engine torque limiting means for limiting the output torque of the engine in accordance with the fatigue degree calculated by the fatigue degree calculating means.

  According to this configuration, the fatigue level calculating means for calculating the fatigue level of the driving force transmission device based on the torque input to the driving force transmission device from a predetermined relationship, and the fatigue level calculation means. Engine torque limiting means for limiting the output torque of the engine according to the degree of fatigue, the engine torque is limited within a range that does not become excessive according to the remaining life of the driving force transmission device. It can be carried out. In other words, it is possible to provide a vehicle engine control apparatus that performs sufficient engine torque limitation as necessary.

  Here, preferably, a storage device that stores the fatigue level calculated by the fatigue level calculation unit is provided, and the engine torque limiting unit is configured to store the fatigue level according to the fatigue level stored in the storage device. This is to limit the engine output torque. In this way, it is possible to limit the engine torque in a practical manner by storing and using the calculated degree of fatigue of the driving force transmission device as needed.

  Preferably, the driving force transmission device further includes torque estimating means for estimating a torque input to a predetermined portion, and the fatigue degree calculating means has a predetermined relationship corresponding to the portion. Based on the torque estimated by the torque estimating means, the degree of fatigue of the portion is calculated. In this way, by limiting the output torque of the engine according to the degree of fatigue particularly in the portion where the strength is a problem in the driving force transmission device, sufficient engine torque limitation necessary and practical can be achieved. It can be carried out.

  Preferably, the fatigue level calculation means calculates a cumulative torque frequency as the fatigue level according to a minor rule based on the torque estimated by the torque estimation means, and the engine torque limiting means When the cumulative torque frequency calculated by the fatigue degree calculating means is larger than a predetermined threshold, the engine output torque is limited. In this way, the engine torque can be sufficiently limited as required in a practical manner.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram illustrating a configuration of a driving force transmission device 8 to which the present invention is preferably applied. FIG. 2 is an operation for explaining a combination of operations of engagement devices (engagement elements) when a plurality of gear stages (shift stages) are established in the automatic transmission 10 provided in the driving force transmission device 8. It is a chart (engagement operation table). This automatic transmission 10 includes a first transmission unit mainly composed of a double pinion type first planetary gear unit 12 in a transmission case (hereinafter referred to as a case) 30 as a non-rotating member attached to a vehicle body. 14 and a second transmission 20 composed mainly of a single-pinion type second planetary gear unit 16 and a double-pinion type third planetary gear unit 18 on a common axis C, and an input shaft 22 Are rotated and output from the output shaft 24. The input shaft 22 corresponds to an input rotating member, and in this embodiment, a turbine shaft of a torque converter 28 that is rotationally driven by an engine 26 as a driving power source for traveling which is an internal combustion engine such as a gasoline engine or a diesel engine. It is. The output shaft 24 corresponds to an output rotating member, and rotationally drives the left and right drive wheels 74 sequentially through, for example, a differential gear device (final reduction gear) 70, a pair of axles 72, and the like (see FIG. 3). The automatic transmission 10 is configured substantially symmetrically with respect to the center line (axial center) C, and the lower half of the axial center C is omitted in the skeleton diagram of FIG.

  The first planetary gear device 12 includes a sun gear S1, a plurality of pairs of pinion gears P1 that mesh with each other, a carrier CA1 that supports the pinion gears P1 so as to rotate and revolve, and a ring gear R1 that meshes with the sun gear S1 via the pinion gears P1. The carrier CA1 and the ring gear R1 constitute three rotating elements. The carrier CA1 is coupled to the input shaft 22 and driven to rotate, and the sun gear S1 is fixed to the case 30 so as not to rotate. The ring gear R <b> 1 functions as an intermediate output member, is rotated at a reduced speed with respect to the input shaft 22, and transmits the rotation to the second transmission unit 20. In the present embodiment, the path for transmitting the rotation of the input shaft 22 to the second transmission unit 20 at the same speed is the first intermediate that transmits the rotation at a predetermined constant gear ratio (= 1.0). The output path PA1, and the first intermediate output path PA1 includes a direct connection path PA1a that transmits rotation from the input shaft 22 to the second transmission unit 20 without passing through the first planetary gear unit 12, and the input shaft. 22 and an indirect path PA1b for transmitting rotation to the second transmission 20 through the carrier CA1 of the first planetary gear unit 12. Further, the transmission ratio from the input shaft 22 through the carrier CA1, the pinion gear P1 disposed on the carrier CA1, and the ring gear R1 to the second transmission unit 20 is larger than the first intermediate output path PA1. > 1.0) is a second intermediate output path PA2 that transmits the rotation of the input shaft 22 with a reduced speed (deceleration).

  The second planetary gear device 16 includes a sun gear S2, a pinion gear P2, a carrier CA2 that supports the pinion gear P2 so as to rotate and revolve, and a ring gear R2 that meshes with the sun gear S2 via the pinion gear P2. The third planetary gear unit 18 includes a sun gear S3, a plurality of pairs of pinion gears P2 and P3 that mesh with each other, a carrier CA3 that supports the pinion gears P2 and P3 so as to be capable of rotating and revolving, and a sun gear S3 via the pinion gears P2 and P3. A meshing ring gear R3 is provided.

  In the second planetary gear device 16 and the third planetary gear device 18, four rotating elements RM <b> 1 to RM <b> 4 are configured by being partially connected to each other. Specifically, the first rotating element RM1 is constituted by the sun gear S2 of the second planetary gear device 16, and the carrier CA2 of the second planetary gear device 16 and the carrier CA3 of the third planetary gear device are integrally connected to each other. Thus, the second rotating element RM2 is configured, and the ring gear R2 of the second planetary gear device 16 and the ring gear R3 of the third planetary gear device 18 are integrally connected to each other to configure the third rotating element RM3. The fourth rotating element RM4 is configured by the sun gear S3 of the three planetary gear unit 18. In the second planetary gear device 16 and the third planetary gear device 18, the carriers CA2 and CA3 are configured by a common member, the ring gears R2 and R3 are configured by a common member, and the second planetary gear device 18 The pinion gear P <b> 2 of the planetary gear device 16 is a Ravigneaux type planetary gear train that also serves as the second pinion gear of the third planetary gear device 18.

  The first rotating element RM1 (sun gear S2) is selectively coupled to the case 30 via the first brake B1 and stopped rotating, and the first planetary gear which is an intermediate output member via the third clutch C3. Is selectively connected to the ring gear R1 of the device 12 (ie, the second intermediate output path PA2), and further via the fourth clutch C4, the carrier CA1 of the first planetary gear device 12 (ie, the indirect path of the first intermediate output path PA1). Selectively linked to PA1b). The second rotation element RM2 (carriers CA2 and CA3) is selectively connected to the case 30 via the second brake B2 and stopped rotating, and the input shaft 22 (ie, the second rotation element RM2 (carriers CA2 and CA3) via the second clutch C2). It is selectively connected to the direct connection path PA1a) of the first intermediate output path PA1. The third rotation element RM3 (ring gears R2 and R3) is integrally connected to the output shaft 24 to output rotation. The fourth rotation element RM4 (sun gear S3) is connected to the ring gear R1 via the first clutch C1. Between the second rotating element RM2 and the case 30, there is a one-way clutch F1 that prevents the reverse rotation while allowing the second rotating element RM2 to rotate forward (the same rotational direction as the input shaft 22). 2 brakes B2 are provided in parallel.

The engagement operation table of FIG. 2 is a table for explaining the operation states of the clutches C1 to C4 and the brakes B1 and B2 when each gear stage of the automatic transmission 10 is established, and “◯” indicates the engagement state. , “(◯)” represents the engaged state only during engine braking, and the blank represents the released state. As described above, the automatic transmission 10 includes three sets of planetary gear units 12, 16, and 18, and selectively engages the clutches C1 to C4 and the brakes B1 and B2 to thereby change the gear ratio γ (= input). A plurality of gear stages having different shaft rotation speeds N _IN / output shaft rotation speeds N _OUT ), for example, multi-speed shifting with eight forward speeds is achieved. In particular, since the one-way clutch F1 is provided in parallel with the second brake B2, when the first gear (1st) is established, the second brake B2 is engaged during engine braking, It is released when driving.

  Further, the gear ratios that are different for each gear stage are appropriately determined by the gear ratios ρ1, ρ2, and ρ3 of the first planetary gear device 12, the second planetary gear device 16, and the third planetary gear device 18. In addition, the clutches C1 to C4 and the brakes B1 and B2 (hereinafter simply referred to as the clutch C and the brake B unless otherwise distinguished) are preferably controlled by a hydraulic actuator such as a multi-plate clutch or a brake. This is a hydraulic friction engagement device (hereinafter referred to as an engagement device). The engagement and release states are switched by excitation, de-excitation, and current control of the linear solenoid valves SL1 to SL6 in the hydraulic control circuit 76 shown in FIG. And the transient hydraulic pressure at the time of engagement and release is controlled.

  FIG. 3 is a block diagram for explaining a main part of a control system provided in the vehicle for controlling the automatic transmission 10 and the engine 26 and the like. The electronic control device 100 shown in FIG. 3 includes, for example, a so-called microcomputer having a CPU, RAM, ROM, input / output interface, and the like. Signal processing is performed according to the stored program. By such signal processing, output control of the engine 26 described later, shift control of the automatic transmission 10, and the like are executed. Further, it is divided into an engine control and a shift control for controlling the linear solenoid valves SL1 to SL6 as required.

As shown in FIG. 3, various signals are supplied to the electronic control device 100 from sensors and switches provided in the vehicle. For example, a crank angle (position) ACR (°) and the crank position sensor 32 for detecting a crank position corresponding to the rotational speed N _E of the engine 26, the input of the turbine rotational speed N _T i.e. the automatic transmission 10 of the torque converter 28 A turbine rotational speed sensor 34 for detecting the rotational speed N _IN of the shaft 22, an output shaft rotational speed sensor 36 for detecting the rotational speed N _OUT of the output shaft 24 corresponding to the vehicle speed V, and an intake air amount Q _AIR of the engine 26 an intake air amount sensor 38 to be detected, the shift position sensor 42 for detecting a lever position (operating position) P _SH of the shift lever 40 as a manual transmission operating device, which detects the accelerator opening a _CC is an operation amount of an accelerator pedal 44 An opening angle of an electronic throttle valve 50 provided in an accelerator opening sensor 46 and an intake pipe 48 Throttle position sensor 52 for detecting the KazuSatoshi throttle valve opening theta _TH, a brake switch 56 for detecting a brake operation signal B _ON indicating the presence or absence of operation of the foot brake 54 is a service brake, the working oil of the hydraulic control circuit 76 From the AT oil temperature sensor 58 for detecting the AT oil temperature T _OIL , the acceleration sensor 60 for detecting the vehicle acceleration (deceleration) G, and the like, and the crank angle (position) ACR (°) and the engine Rotational speed N _E , turbine rotational speed N _T (= input shaft rotational speed N _IN ), vehicle speed V, output shaft rotational speed N _OUT , intake air amount Q _AIR , lever position P _SH , accelerator opening A _CC , throttle valve open Signals representing the degree θ _TH , the brake operation signal B _ON , the AT oil temperature T _OIL , the acceleration (deceleration) G, and the like are supplied to the electronic control unit 100.

The electronic control device 100 outputs a signal for controlling the operation of various devices. For example, the engine output control command signal S _E for output control of the engine 26, the drive signal to the throttle actuator 62 for controlling the opening / closing of the electronic throttle valve 50 according to the accelerator opening degree A _CC , and the fuel injection device 64 An injection signal for controlling the amount of fuel injected from the engine, an ignition timing signal for controlling the ignition timing of the engine 26 by the igniter 66, and the like are output. Further, a shift control command signal S _P for shift control of the automatic transmission 10, for example, excitation of the linear solenoid valves SL 1 to SL 6 in the hydraulic control circuit 76 for switching the shift stage of the automatic transmission 10, non-excitation. A valve command signal for controlling excitation and the like, a drive signal to the linear solenoid valve SLT for controlling the line hydraulic pressure PL, and the like are output.

  4 is a circuit diagram relating to the linear solenoid valves SL1 to SL6 and the like for controlling the operation of the hydraulic actuators of the clutch C and the brake B, and is a circuit diagram showing the main part of the hydraulic control circuit 76. In FIG. 4, the D range pressure (forward range pressure, forward speed) output from the hydraulic pressure supply device 90 is applied to the hydraulic actuators (hydraulic cylinders) 78, 80, 86, 88 of the clutches C1, C2 and brakes B1, B2. Hydraulic pressure PD is regulated and supplied by linear solenoid valves SL1, SL2, SL5, and SL6, respectively, and the hydraulic actuators 82 and 84 of the clutches C3 and C4 are respectively supplied with the line hydraulic pressure PL1 output from the hydraulic pressure supply device 90. The pressure is regulated and supplied by the linear solenoid valves SL3 and SL4. The hydraulic actuator 88 of the brake B2 is supplied with the hydraulic pressure supplied from either the output hydraulic pressure of the linear solenoid valve SL6 or the reverse pressure (reverse range pressure, reverse hydraulic pressure) PR via the shuttle valve 99.

The hydraulic pressure supply device 90 adjusts the line hydraulic pressure PL1 (first line hydraulic pressure PL1) using the hydraulic pressure generated from a mechanical oil pump 68 (see FIG. 1) rotated and driven by the engine 26 as a source pressure, for example, a relief type. The first pressure regulating valve (primary regulator valve) 92 and the line hydraulic pressure PL2 (second line hydraulic pressure PL2, secondary pressure PL2) with the hydraulic pressure discharged from the first pressure regulating valve 92 as the primary pressure for regulating the line hydraulic pressure PL1 second pressure regulating valve which applies the tone (secondary regulator valve) 94, first to be pressurized line oil pressure PL1, PL2 two tone in accordance with the engine load or the like represented by the accelerator opening a _CC or the throttle valve opening theta _TH the linear solenoid valve SLT supplies a signal pressure P _SLT to pressure regulating valve 92 and the second pressure regulating valve 94, modular line pressure PL1 as the original pressure It is inputted by switching the oil path by being mechanically operated in accordance with the operation of the modulator valve 96 for adjusting the regulator hydraulic pressure PM to a constant value and the shift lever 40 mechanically connected via a cable or a link. The manual hydraulic valve 98 that outputs the line hydraulic pressure PL1 as the D range pressure PD when the shift lever 40 is operated to the "D" position or the "S" position or the reverse pressure PR when the shift lever 40 is operated to the "R" position. And supply line oil pressures PL1, PL2, modulator oil pressure PM, D range pressure PD, and reverse pressure PR.

  The linear solenoid valves SL1 to SL6 have basically the same configuration, and are excited and de-energized independently by the electronic control unit 100, and the hydraulic pressures of the hydraulic actuators 78 to 88 are independently controlled to be controlled by the clutch. The engagement pressures of C1 to C4 and brakes B1 and B2 are controlled. Thereby, in the automatic transmission 10, for example, as shown in the engagement operation table of FIG. 2, each gear stage is established by engaging a predetermined engagement device. In the shift control of the automatic transmission 10, for example, a so-called clutch-to-clutch shift is performed in which the release and engagement of the clutch C and the brake B involved in the shift are controlled simultaneously. For example, as shown in the engagement operation table of FIG. 2, in the downshift from the fifth speed to the fourth speed, the clutch C2 is disengaged and the clutch C4 is engaged, so that the release transient hydraulic pressure of the clutch C2 is suppressed so as to suppress the shift shock. And the engagement transient hydraulic pressure of the clutch C4 are appropriately controlled. Thus, since the engagement devices (clutch C and brake B) of the automatic transmission 10 are controlled by the linear solenoid valves SL1 to SL6, the responsiveness of the operation of the engagement device is improved. Alternatively, the hydraulic circuit for the engagement / release operation of the engagement device is simplified.

  The shift lever 40 is disposed near the driver's seat, for example, and is manually operated to five lever positions “P”, “R”, “N”, “D”, or “S” as shown in FIG. It has become so. This “P” position (range) releases the power transmission path in the automatic transmission 10, that is, a neutral state (neutral state) in which the power transmission in the automatic transmission 10 is interrupted and is mechanically operated by the mechanical parking mechanism. Is a parking position (position) for preventing (locking) the rotation of the output shaft 24, and the “R” position is a reverse travel position for reversing the rotation direction of the output shaft 24 of the automatic transmission 10. The “N” position is a neutral position (position) for achieving a neutral state in which power transmission in the automatic transmission 10 is interrupted, and the “D” position is a shift of the automatic transmission 10. Automatic shift control is executed using all the forward gears from the first gear stage “1st” to the eighth gear stage “8th” within the shift range (D range) that allows The “S” position is a manual shift by switching multiple types of shift ranges that limit the range of gear speed change, that is, multiple types of shift ranges with different high-speed gears that can be shifted. This is a forward travel position (position).

In the “S” position, the “+” position as the lever position _PSH for shifting the shift range to the up side every time the shift lever 40 is operated, and the shift range to the down side every time the shift lever 40 is operated. A “−” position is provided as a lever position _PSH for shifting. For example, in the “S” position, any of the “8” range to the “L” range is changed according to the operation of the shift lever 40 to the “+” position or the “−” position. The “L” range in the “S” position is also an engine brake range for obtaining a further engine brake effect by engaging the second brake B2 at the first gear stage “1st”.

  Further, the “D” position is an automatic shift that is a control mode in which automatic shift control is performed in a range of, for example, the first gear to the eighth gear as shown in FIG. It is also a shift position for selecting a mode. In the “S” position, automatic shift control is executed within a range not exceeding the maximum speed gear of each shift range of the automatic transmission 10 and the shift lever 40 is manually operated. It is also a shift position for selecting a manual shift mode, which is a control mode in which manual shift control is executed based on the changed shift range (that is, the highest speed gear stage).

FIG. 6 is a functional block diagram for explaining a main part of the control function by the electronic control unit 100. The torque estimation means 102 shown in FIG. 6 estimates the torque of each part in the driving force transmission device 8 such as the engine torque output from the engine 26 and the torque input to the automatic transmission 10. For example, the engine torque T _E is estimated based on the actual engine speed N _E and the throttle opening from the engine torque characteristics (relationship of the engine torque map, etc.) with respect to the throttle opening that is experimentally obtained and stored in advance. Based on the engine torque T _E , the input torque T _IN input to the input shaft 22 of the driving force transmission device 8 is estimated. Preferably, based on the engine torque T _E estimated as described above or the input torque T _IN to the input shaft 22, a predetermined portion of the driving force transmission device 8, for example, the driving force transmission device 8 is particularly suitable. A torque T _PA input to a portion where the strength is a problem (a portion of the drive shaft having the smallest diameter, etc.) is estimated.

The engine drive control means 104 controls the drive of the engine 26. For example, in addition to controlling the opening and closing of the electronic throttle valve 50 by the throttle actuator 62, the engine output control command signal S for controlling the fuel injection device 64 for controlling the fuel injection amount and controlling the igniter 66 for controlling the ignition timing. _E is output. Wherein in opening and closing control of the electronic throttle valve 50, for example, it has been experimentally determined in advance and stored in the engine rotational speed N _E and the engine torque estimated value T _EO throttle valve opening theta _TH as shown in FIG. 7 as a parameter The throttle valve opening θ _TH is controlled by the throttle actuator 62 so that the target engine torque T _E ^* obtained based on the actual engine speed _NE and the accelerator opening degree A _CC from the relationship (engine torque map) is obtained. .

  FIG. 8 is a diagram illustrating a change with time of torque input to a predetermined portion (for example, a ring gear of a planetary gear device) in the driving force transmission device 8. As shown in FIG. 8, when the vehicle travels, the transient torque in the driving force transmission device 8 changes momentarily according to the traveling state. Further, due to the transient torque input to the driving force transmission device 8 in this way, fatigue (fatigue) is accumulated in the driving force transmission device 8 in the form of metal fatigue or the like, and the remaining life (usable period) Gradually decreases.

  FIG. 9 is an example of a torque frequency diagram defined by the number of repetitions of input to the driving force transmission device 8 (horizontal axis) and the magnitude of the input torque (vertical axis). The alternate long and short dash line shown in FIG. 9 is a correlation line that indicates the number of times the torque is input to the predetermined portion of the driving force transmission device 8 and the life of the predetermined portion determined in advance according to the magnitude of the input torque. When the cumulative torque frequency reaches this correlation line, the corresponding portion in the driving force transmission device 8 becomes the life (use limit). This correlation line is expressed as the following equation (1), where T is the input torque, N is the number of repetitions, κ and C are constants. Further, the fatigue strength limit torque Ts shown in FIG. 9 is an upper limit value of torque that is allowed to be input to the corresponding part in the driving force transmission device 8, and is preferably determined according to the remaining life of the part. Although it is a variable value, it may be a fixed value. Further, Nx shown in FIG. 9 is the number of repetitions indicating the life of the corresponding part in the driving force transmission device 8 corresponding to a predetermined input torque Tx, and nx is the driving force transmission device 8 shown by a solid line in FIG. Is the number of repetitions corresponding to the input torque Tx as an equivalent torque (converted to the equivalent torque) with respect to the actual input correlation line to the corresponding part.

  log T = (− 1 / κ) × log N + C (1)

  Returning to FIG. 6, the fatigue level calculating means 106 calculates the fatigue level of the driving force transmission device 8 based on the torque input to the driving force transmission device 8 from a predetermined relationship. Preferably, the cumulative torque frequency D is calculated as the degree of fatigue in accordance with a well-known minor rule based on the torque estimated by the torque estimating means 102. That is, the number of repetitions Ni indicating the life of the corresponding portion in the driving force transmission device 8 at the predetermined equivalent torque Tx as described above and the actual input to the corresponding portion in the driving force transmission device 8 are used as the equivalent torque Tx. From the converted number of repetitions ni, the cumulative torque frequency D as the degree of fatigue of the corresponding portion in the driving force transmission device 8 is calculated according to the following equation (2). Further, the cumulative torque frequency D calculated by the fatigue degree calculating means 106 in this way is cumulatively stored (accumulated) in the storage device 110 shown in FIG.

  D = Σ (ni / Ni) (2)

The engine torque limiting means 108 limits the output torque T _E of the engine 26 according to the fatigue level calculated by the fatigue level calculating means 106. Preferably, when the cumulative torque frequency D calculated by the fatigue level calculating means 106 and stored in the storage device 110 is greater than a predetermined threshold (for example, 1), the output torque of the engine 26 is the same as that shown in FIG. The fatigue strength limit Ts shown in FIG. The output torque of the engine 26 is limited by the opening / closing control of the electronic throttle valve 50, the fuel injection amount control by the fuel injection device 64, the ignition timing control by the igniter 66, etc. via the engine drive control means 104. In this way, the output torque of the engine 26 is limited only when the cumulative torque frequency D of the predetermined portion in the driving force transmission device 8 is equal to or higher than the predetermined threshold value and it is determined that the life of the portion is approaching. By doing so, it is possible to realize a sufficient engine torque limit if necessary.

  FIG. 10 is a flowchart for explaining a main part of the engine torque limit control by the electronic control unit 100, and is repeatedly executed with an extremely short cycle time of, for example, about several milliseconds to several tens of milliseconds.

First, in step (hereinafter, step is omitted) S1, the engine torque T _E is determined based on the actual engine speed N _E and the throttle opening from the engine torque characteristic with respect to the throttle opening that is experimentally obtained and stored in advance. Is calculated (estimated). Next, in S2, based on the engine torque T _E calculated in S1, the input torque waveform to the drive shaft, which is the portion where the strength is particularly problematic (the weakest portion) in the driving force transmission device 8, is estimated. Is done. Next, in S3 corresponding to the operation of the fatigue degree calculating means 106, the information stored in the storage device 110 is read out and based on the input torque waveform estimated in S2 according to a well-known minor rule. The degree of fatigue (cumulative torque frequency) D of the corresponding part is calculated, and the calculation result is cumulatively stored in the storage device 110. Next, in S4, it is determined whether or not the fatigue level D calculated in S3 is larger than a predetermined threshold, for example, 1. If the determination in S4 is negative, the output torque limit of the engine 26 is not performed, and this routine is terminated accordingly. If the determination in S4 is affirmative, the engine 26 is determined in S5. After the output torque is limited to the fatigue strength limit Ts or less, this routine is terminated. In the above control, S1 and S2 correspond to the operation of the torque estimating means 102, and S4 and S5 correspond to the operation of the engine torque limiting means 108, respectively.

  Thus, according to the present embodiment, the fatigue level calculating means 106 (S3) that calculates the fatigue level of the driving force transmission device 8 based on the torque input to the driving force transmission device 8 from a predetermined relationship. ) And engine torque limiting means 108 (S4 and S5) for limiting the output torque of the engine 26 in accordance with the fatigue level calculated by the fatigue level calculating means 106, the driving force The engine torque can be limited within a range that does not become excessive according to the remaining life of the transmission device 8. In other words, it is possible to provide a vehicle engine control apparatus that performs sufficient engine torque limitation as necessary.

  In addition, a storage device 110 that stores the fatigue level calculated by the fatigue level calculation unit 106 is provided, and the engine torque limiting unit 108 includes the engine according to the fatigue level stored in the storage device 110. Therefore, the engine torque can be limited in a practical manner by storing and using the calculated degree of fatigue of the driving force transmission device 8 as needed.

  The driving force transmission device 8 includes torque estimating means 102 (S1 and S2) for estimating torque input to a predetermined portion, and the fatigue degree calculating means 106 is determined in advance corresponding to the portion. From this relationship, the degree of fatigue of the portion is calculated based on the torque estimated by the torque estimating means 102. Therefore, in the driving force transmission device 8, the degree of fatigue particularly in the portion where the strength is a problem is determined. By limiting the output torque of the engine 26, it is possible to perform sufficient engine torque limitation in a practical manner.

  The fatigue level calculating means 106 calculates the cumulative torque frequency D as the fatigue level according to a minor rule based on the torque estimated by the torque estimating means 102, and the engine torque limiting means 108 Since the output torque of the engine 26 is limited when the cumulative torque frequency D calculated by the fatigue degree calculating means 106 is larger than a predetermined threshold value, sufficient engine torque limitation is necessary in a practical manner. It can be carried out.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiment, the example in which the present invention is applied to the driving force transmission device 8 provided with the automatic transmission 10 has been described. However, the present invention is not limited to this, and is a manual stepped step. The present invention is also suitably applied to a driving force transmission device including a continuously variable transmission such as a transmission or CVT.

  In the above-described embodiment, the example in which the present invention is applied to limit the output torque of the engine 26 that is an internal combustion engine such as a gasoline engine or a diesel engine has been described. However, an electric motor, a hydrogen fuel engine, or the like is used as a driving force source. The present invention may be applied to a vehicle that does this.

  In the above-described embodiment, the degree of fatigue of the driving force transmission device 8 is calculated based on the torque estimated by the torque estimating means 102 from a predetermined relationship. Thus, the actual input torque to the drive shaft or the like in the driving force transmission device 8 may be detected, and the degree of fatigue of the driving force transmission device 8 may be calculated based on the detected torque.

  Further, in the above-described embodiment, the fatigue level calculating means 106 calculates the cumulative torque frequency D as the fatigue level according to a minor rule based on the torque input to the driving force transmission device 8. Various values can be considered as the degree of fatigue of the driving force transmission device 8, and various methods and relationships are appropriately selected and used for the calculation.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating a configuration of a driving force transmission device to which the present invention is preferably applied. 2 is an operation chart for explaining combinations of operations of engagement devices when a plurality of gear stages are established in the automatic transmission provided in the driving force transmission device of FIG. 1. It is a block diagram explaining the principal part of the control system provided in the vehicle in order to control the automatic transmission and engine with which the driving force transmission apparatus of FIG. 1 was equipped. FIG. 2 is a circuit diagram relating to a linear solenoid valve for controlling the operation of clutch and brake hydraulic actuators in the automatic transmission provided in the driving force transmission device of FIG. 1, and is a circuit diagram showing a main part of the hydraulic control circuit. It is a figure explaining the shift lever as a manual transmission operation apparatus of the automatic transmission with which the driving force transmission apparatus of FIG. 1 was equipped. It is a functional block diagram explaining the principal part of the control function by the electronic controller of FIG. FIG. 2 is a diagram exemplifying a relationship that is experimentally obtained and stored in advance between an engine rotation speed and an estimated engine torque value using a throttle valve opening as a parameter, which is used for estimation of engine torque in the driving force transmission device of FIG. It is a figure which illustrates the time-dependent change of the torque input into the predetermined part in the driving force transmission apparatus of FIG. FIG. 2 is an example of a torque frequency diagram defined by the number of repetitions of input to the driving force transmission device of FIG. 1 and the magnitude of input torque. It is a flowchart explaining the principal part of the engine torque limitation control by the electronic controller of FIG.

Explanation of symbols

8: Driving force transmitting device 26: Engine 74: Driving wheel 102: Torque estimating means 106: Fatigue degree calculating means 108: Engine torque limiting means 110: Storage device

Claims (4)

A vehicle engine control device for controlling the engine in a vehicle including an engine that generates a driving force and a driving force transmission device that transmits the driving force output from the engine to driving wheels. And
A fatigue degree calculating means for calculating a fatigue degree of the driving force transmission device based on a torque input to the driving force transmission device from a predetermined relationship;
An engine control device for a vehicle, comprising: engine torque limiting means for limiting the output torque of the engine in accordance with the fatigue level calculated by the fatigue level calculating means.   A storage device that stores the fatigue level calculated by the fatigue level calculation unit is provided, and the engine torque limiting unit limits the output torque of the engine according to the fatigue level stored in the storage device. The vehicle engine control device according to claim 1, which is a device.   A torque estimation unit configured to estimate a torque input to a predetermined portion of the driving force transmission device; and the fatigue level calculation unit is estimated by the torque estimation unit based on a predetermined relationship corresponding to the portion. The vehicle engine control device according to claim 1 or 2, wherein the degree of fatigue of the portion is calculated on the basis of the torque.   The fatigue degree calculating means calculates a cumulative torque frequency as the fatigue degree according to a minor rule based on the torque estimated by the torque estimating means, and the engine torque limiting means is calculated by the fatigue degree calculating means. 4. The vehicle engine control device according to claim 3, wherein the engine output torque is limited when the accumulated torque frequency is greater than a predetermined threshold value.

Images