JP2007162584A - Control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration in durability of a one-way clutch, when wheel spin occurs. <P>SOLUTION: An ECU executes a program comprising: a step S200 for detecting a turbine revolution speed NT when an accelerator is ON in a first speed (YES in S100); a step for calculating a first speed synchronous revolution speed N(1); a step S400 calculating a one-way clutch revolution speed N from NT-N(1); a step S700 for closing the opening of an electronic throttle valve up to predetermined opening, when fluctuation in one-way clutch revolution speed N is large (YES in S500); and a step S900 for sweeping up the opening of the electronic throttle valve and restoring it to the initial opening, after a predetermined time (YES in S800). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to control of an automatic transmission that is mounted on a vehicle and has a one-way clutch (hereinafter, sometimes referred to as a one-way clutch or OWC), and more particularly, the durability of the one-way clutch can be reduced at a low cost when foil spinning is performed. The present invention relates to a control device that can avoid deterioration.

  The automatic transmission selectively forms various friction engagement elements (clutch, brake) by hydraulic operation (engagement, release), and changes the friction engagement element to be operated to change to another gear stage. It is configured to perform a shift.

  By the way, in the upshift from the low speed stage to the high speed stage, the power transmission at the low speed stage is performed via the one-way clutch, and the shift to the high speed stage is completed by releasing the one-way clutch. This is preferable because it is easy to take a countermeasure against shock, and many automatic transmissions adopt this method.

  In addition, the one-way clutch is provided so that the engine brake does not act during inertial running in a state where a desired gear ratio is selected. For this reason, during acceleration from inertial running, there is a time during which power is not transmitted until the one-way clutch changes from a non-driving state (floating state) to a driving state (synchronous state).

  Regarding such a one-way clutch, Japanese Patent Laid-Open No. 6-185607 (Patent Document 1) discloses an engagement shock of an automatic transmission that prevents an engagement shock of the one-way clutch in the automatic transmission when shifting from inertial running to power-on running. A prevention device is disclosed. This engagement shock prevention device has a gear stage for transmitting engine power via a one-way clutch, and during inertial running at the gear stage, the torque converter is moved from a lock-up ON state in which the input / output elements are directly connected. In an automatic transmission that is in a lock-up OFF state in which the direct connection between the input and output elements is released or in an intermediate state between the lock-up ON state and the lock-up OFF state, from inertial running at the shift stage to power-on running The driving form transition detecting means for detecting the transition of the engine and the acceleration of the engine rotation after detecting the transition of the traveling form are calculated, and the engine speed is set to the lock-up ON state from the acceleration and the current engine speed. Synchronous timing estimating means for estimating a timing that coincides with the transmission input rotational speed at the shift stage, and the estimated timing Output elements of torque converter to synchronize to and a lock-up returning means for returning to the lock-up ON state of being directly connected.

According to the automatic transmission one-way clutch engagement shock prevention device of this automatic transmission, the automatic transmission locks the torque converter in the lock-up OFF state or locks up during inertial traveling at a gear stage that transmits engine power via the one-way clutch. An intermediate state between the ON state and the lockup OFF state is formed. Here, when shifting to power-on traveling, after the traveling form transition detecting means detects this, the synchronization timing estimating means calculates the acceleration of the engine rotation, and from this acceleration and the current engine rotational speed, the engine rotational speed is calculated. A timing that coincides with the transmission input rotational speed at the shift stage in the lock-up ON state is estimated. The lockup return means returns the torque converter to the lockup ON state so as to synchronize with the estimated timing. Therefore, the engagement shock of the one-way clutch accompanying the transition from the inertia traveling to the power-on traveling can be prevented by the slip of the torque converter. By the way, since the timing for returning the torque converter to the lock-up ON state is controlled as described above, the suitable timing varies depending on the accelerator pedal depression amount, the automatic transmission hydraulic oil temperature, the age of use of the vehicle, and the like. Even if it is a thing, the timing which returns a torque converter to a lockup ON state can always be matched with the said suitable timing reliably, the said effect | action can be produced reliably, and it accompanies with transfer to power-on driving | running | working It is possible to avoid the occurrence of problems such as that the one-way clutch engagement shock cannot be reliably prevented and the engine blows away.
JP-A-6-185607

  The one-way clutch used in such an automatic transmission restricts the rotation of the outer race and the inner race (for example) when the first gear is driven, and rotates the outer race and the inner race when driven. Is allowed. By the way, when the gear stage using the one-way clutch (first speed in the above example) is formed, if the accelerator pedal is suddenly depressed greatly or the μ value (friction resistance) of the road surface is small, the wheel spin is reduced. appear. When such wheel spin occurs, the rotation speed of the one-way clutch fluctuates greatly, and the piece (roller or sprag) of the one-way clutch swings abnormally. This may deteriorate the durability of the transmission.

  For such problems, it is also effective to install a driving force control system such as TRC (TRaction Control).

  However, the introduction of TRC causes an increase in cost. Also, the above-mentioned Patent Document 1 does not pay attention to such a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a low-cost vehicle control apparatus that does not deteriorate the durability of the one-way clutch when wheel spin occurs. Is to provide.

  A control device according to a first invention controls a vehicle including a power source and an automatic transmission connected to the power source. A one-way clutch is interposed in the power transmission path including the automatic transmission. The one-way clutch is locked when power is input from the input side of the automatic transmission, and the power is transmitted from the output side of the automatic transmission. Has a structure that idles when. The vehicle control device includes a rotational speed detection means for detecting a rotational speed difference before and after the one-way clutch, and a determination for determining whether or not the vehicle is in a wheel spin state based on the detected rotational speed. And a control means for controlling the power source so as to reduce the output when it is detected that the wheel spin state is established.

  According to the first invention, if the difference in the number of revolutions before and after the one-way clutch (one-way clutch) fluctuates greatly, for example, it is determined that the vehicle is spinning the wheel, and the output of the power source is reduced. The For this reason, since the power on the input side of the automatic transmission is reduced, it is possible to avoid abnormal swing of the top piece (roller or sprag) of the one-way clutch. Since it is such a structure, it is not necessary to have a special mechanism. As a result, it is possible to provide a vehicle control device that is inexpensive and does not deteriorate the durability of the one-way clutch when wheel spin occurs.

  In the vehicle control apparatus according to the second invention, in addition to the configuration of the first invention, the determining means includes means for determining that the vehicle is in a wheel spin state when the variation in the rotational speed difference is large. Including.

  According to the second aspect of the present invention, when the difference in the number of revolutions before and after the one-way clutch fluctuates greatly (the vibration period is large and the vibration width is large), it can be determined that the vehicle is spinning.

  In the vehicle control apparatus according to the third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, the control means controls the power source so that the output of the power source is gradually changed and lowered. including.

  According to the third aspect of the present invention, it is possible to avoid the occurrence of a shock due to a sudden decrease in the output of the power source for gradually decreasing the output of the power source.

  In addition to the configuration of any one of the first to third inventions, the vehicle control device according to the fourth invention controls the power source so as to decrease the output, and then gradually increases the output to increase the power source. Further comprising means for controlling the power source.

  According to the fourth invention, even when the vehicle is not in the state of being foil-spinned, it is possible to reduce the possibility of performing the wheel-spin again for gradually increasing the output of the power source.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A vehicle equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. This vehicle is an FF (Front engine Front drive) vehicle. A vehicle other than FF may be used.

  The vehicle includes an engine 1000, an automatic transmission 2000, a planetary gear unit 3000 constituting a part of the automatic transmission 2000, a hydraulic circuit 4000 constituting a part of the automatic transmission 2000, a differential gear 5000, a drive shaft 6000, Front wheel 7000 and ECU (Electronic Control Unit) 8000 are included.

  Engine 1000 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 3200. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage.

  The output gear of automatic transmission 2000 is meshed with differential gear 5000. A drive shaft 6000 is connected to the differential gear 5000 by spline fitting or the like. Power is transmitted to the left and right front wheels 7000 via the drive shaft 6000.

  The ECU 8000 includes a vehicle speed sensor 8002, a position switch 8006 of a shift lever 8004, an accelerator opening sensor 8010 of an accelerator pedal 8008, a stroke sensor 8014 of a brake pedal 8012, a throttle opening sensor 8018 of an electronic throttle valve 8016, An engine speed sensor 8020, an input shaft speed sensor 8022, and an output shaft speed sensor 8024 are connected via a harness or the like.

  Vehicle speed sensor 8002 detects the speed of the vehicle from the rotational speed of drive shaft 6000 and transmits a signal representing the detection result to ECU 8000. The position of shift lever 8004 is detected by position switch 8006, and a signal representing the detection result is transmitted to ECU 8000. Corresponding to the position of the shift lever 8004, the gear stage of the automatic transmission 2000 is automatically formed. Further, a manual shift mode in which the driver can select an arbitrary gear stage may be selected according to the driver's operation.

  Accelerator opening sensor 8010 detects the opening of accelerator pedal 8008 and transmits a signal representing the detection result to ECU 8000. Stroke sensor 8014 detects the stroke amount of brake pedal 8012 and transmits a signal representing the detection result to ECU 8000.

  The throttle opening sensor 8018 detects the opening of the electronic throttle valve 8016 whose opening is adjusted by the actuator, and transmits a signal indicating the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Engine rotation speed sensor 8020 detects the rotation speed of the output shaft (crankshaft) of engine 1000 and transmits a signal representing the detection result to ECU 8000. Input shaft rotational speed sensor 8022 detects input shaft rotational speed NI of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000. Output shaft rotation speed sensor 8024 detects output shaft rotation speed NOUT of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000. The input shaft rotational speed NI of the automatic transmission 2000 is a turbine rotational speed NT of a torque converter 3200 described later.

  ECU 8000 is sent from vehicle speed sensor 8002, position switch 8006, accelerator opening sensor 8010, stroke sensor 8014, throttle opening sensor 8018, engine speed sensor 8020, input shaft speed sensor 8022, output shaft speed sensor 8024, and the like. Based on the received signal, a map and a program stored in a ROM (Read Only Memory), the devices are controlled so that the vehicle is in a desired running state.

  In the present embodiment, ECU 8000 automatically sets any one of the first to sixth gears according to a separately defined shift diagram when shift lever 8004 is in the D (drive) position. The automatic transmission 2000 is controlled to be formed. The automatic transmission 2000 can transmit the driving force to the front wheels 7000 by forming any one of the first to sixth gears.

  The planetary gear unit 3000 will be described with reference to FIG. Planetary gear unit 3000 is connected to a torque converter 3200 having an input shaft 3100 coupled to a crankshaft. Planetary gear unit 3000 includes a first set 3300 of planetary gear mechanisms, a second set 3400 of planetary gear mechanisms, an output gear 3500, a B1 brake 3610, a B2 brake 3620 and a B3 brake 3630 fixed to gear case 3600, and C1. Clutch 3640 and C2 clutch 3650, and one-way clutch F3660 are included.

  The first set 3300 is a single pinion type planetary gear mechanism. First set 3300 includes sun gear S (UD) 3310, pinion gear 3320, ring gear R (UD) 3330, and carrier C (UD) 3340.

  Sun gear S (UD) 3310 is coupled to output shaft 3210 of torque converter 3200. Pinion gear 3320 is rotatably supported by carrier C (UD) 3340. Pinion gear 3320 is in mesh with sun gear S (UD) 3310 and ring gear R (UD) 3330.

  Ring gear R (UD) 3330 is fixed to gear case 3600 by B3 brake 3630. Carrier C (UD) 3340 is fixed to gear case 3600 by B1 brake 3610.

  The second set 3400 is a Ravigneaux type planetary gear mechanism. The second set 3400 includes a sun gear S (D) 3410, a short pinion gear 3420, a carrier C (1) 3422, a long pinion gear 3430, a carrier C (2) 3432, a sun gear S (S) 3440, and a ring gear R. (1) (R (2)) 3450.

  Sun gear S (D) 3410 is coupled to carrier C (UD) 3340. Short pinion gear 3420 is rotatably supported by carrier C (1) 3422. Short pinion gear 3420 is in mesh with sun gear S (D) 3410 and long pinion gear 3430. Carrier C (1) 3422 is coupled to output gear 3500.

  Long pinion gear 3430 is rotatably supported by carrier C (2) 3432. Long pinion gear 3430 is in mesh with short pinion gear 3420, sun gear S (S) 3440, and ring gear R (1) (R (2)) 3450. Carrier C (2) 3432 is coupled to output gear 3500.

  Sun gear S (S) 3440 is coupled to output shaft 3210 of torque converter 3200 by C1 clutch 3640. Ring gear R (1) (R (2)) 3450 is fixed to gear case 3600 by B2 brake 3620 and connected to output shaft 3210 of torque converter 3200 by C2 clutch 3650. The ring gear R (1) (R (2)) 3450 is connected to the one-way clutch F3660, and cannot rotate when the first gear is driven.

  The one-way clutch F3660 is provided in parallel with the B2 brake 3620. That is, the outer race of the one-way clutch F3660 is fixed to the gear case 3600, and the inner race is connected to the ring gear R (1) (R (2)) 3450 via the rotation shaft.

  FIG. 3 shows an operation table showing the relationship between each gear position and the operation state of each clutch and each brake. By operating each brake and each clutch with the combinations shown in this operation table, a forward gear stage of 1st to 6th speed and a reverse gear stage are formed.

  As shown in FIG. 3, the C1 clutch 3640 is engaged in all the gears from the first gear to the fourth gear. That is, it can be said that the C1 clutch 3640 is an input clutch in the first gear to the fourth gear. C2 clutch 3650 is engaged in the fifth gear to the sixth gear. That is, it can be said that the C2 clutch 3650 is an input clutch in the fifth gear to the sixth gear.

  In such a configuration, in the present embodiment, the output of the engine 1000 is set so that the durability of the one-way clutch F3660 is not deteriorated even if the driving wheel of the vehicle at the time of starting at the 1st wheel spins. adjust.

  With reference to FIG. 4, a control structure of a program executed by ECU 8000 which is the control device according to the present embodiment will be described.

  In step (hereinafter step is abbreviated as S) 100, ECU 8000 determines whether or not the accelerator is in the first gear (1st) and the accelerator pedal is depressed. If the first speed (1st) and the accelerator pedal is depressed (YES in S100), the process proceeds to S200. Otherwise (NO in S100), this process ends.

  In S200, ECU 8000 detects turbine rotational speed NT. In S300, ECU 8000 calculates first-speed synchronous rotation speed N (1). In S400, ECU 8000 calculates the rotation speed difference calculated by (turbine rotation speed NT-1 speed synchronous rotation speed N (1)) as one-way clutch (OWC) rotation speed N.

  In S500, the fluctuation of OWC rotation speed N is calculated, and it is determined whether or not the fluctuation exceeds a preset threshold value (vibration width, vibration period). If variation in OWC rotation speed N exceeds a preset threshold value (vibration width, vibration period) (YES in S500), the process proceeds to S600. Otherwise (NO in S500), this process ends.

  In S600, it is determined whether or not the shift command is maintained at the first speed (1st) state. If the first speed (1st) state is maintained (YES in S600), the process proceeds to S700. Otherwise (NO in S600), this process ends.

  In S700, ECU 8000 closes electronic throttle valve 8016 of engine 1000 to a predetermined opening, and reduces the output of engine 1000. At this time, in order to avoid a shock due to a sudden change, it is preferable to reduce it to a ramp shape instead of reducing it stepwise. However, this embodiment does not exclude the stepwise reduction.

  In S800, ECU 8000 determines whether or not a predetermined time has elapsed since electronic throttle valve 8016 of engine 1000 is closed to a predetermined opening degree. If it is determined that a predetermined time has elapsed (YES in S800), the process proceeds to S900. If not (NO in S800), the process waits for S900 until a predetermined time elapses.

  In S900, ECU 8000 sweeps up electronic throttle valve 8016 and returns it to the original opening.

  With reference to FIG. 5, an operation for preventing deterioration of the durability of the one-way clutch during wheel spin controlled by ECU 8000 which is the control device according to the present embodiment based on the above-described structure and flowchart will be described. . The prior art is shown on the upper side of FIG. 5, and the technology of the present invention is shown on the lower side of FIG.

  In the prior art, when the speed is 1st and the accelerator is ON, the opening of the electronic throttle 8016 is opened stepwise so as to correspond to the accelerator pedal opening opened stepwise. For this reason, since the output of the engine 1000 is increased, wheel spin is generated, the vibration width and vibration cycle of the OWC rotational speed N exceed the set value, and the vibration of the vehicle due to the wheel spin increases, and the one-way clutch F3660 Could be damaged.

  On the other hand, in the technique of the present invention, when the first speed and the accelerator is ON (YES in S100), once the accelerator pedal is opened stepwise, the electronic throttle valve 8016 is once opened stepwise (time) t (0)), when the fluctuation of the OWC rotation speed N is large and the state of the first speed command is maintained (YES in S500 and YES in S600), it does not correspond to the accelerator pedal opening, The output of engine 1000 is reduced by reducing the opening of throttle 8016 (S700). This corresponds to time t (2) from time t (1). Thereby, since the output of engine 1000 is reduced, it is possible to prevent the wheel spin from being suppressed and the rotational speed of one-way clutch F3660 from fluctuating greatly. For this reason, since the top (roller or sprag) of the one-way clutch F3660 does not swing abnormally, the possibility of deteriorating the durability of the transmission is reduced.

  When a predetermined time (time from time t (1) to time t (2)) has elapsed (YES in S800), fluctuation in OWC rotational speed N does not become large, so electronic throttle valve 8016 By gradually increasing (sweeping up) the opening, the occurrence of shock can be avoided.

  In S800, the determination may be made not based on the passage of time but based on the fluctuation of the OWC rotational speed N.

  As described above, according to the vehicle control apparatus according to the present embodiment, the one-way clutch that is engaged when the vehicle starts is suppressed without using a driving force control system such as TRC and suppressing wheel spin. The deterioration of durability can be avoided.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram which shows the power train controlled by ECU which is a control apparatus which concerns on embodiment of this invention. It is a skeleton figure which shows the gear train in an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a flowchart which shows the control structure of the program which ECU which is a control apparatus which concerns on embodiment of this invention performs. It is a timing chart when the foil spin occurs at the first speed.

Explanation of symbols

  1000 engine, 2000 automatic transmission, 3000 planetary gear unit, 3100 input shaft, 3200 torque converter, 3210 output shaft, 3610 B1 brake, 3620 B2 brake, 3630 B3 brake, 3640 C1 clutch, 3650 C2 clutch, 3660 one-way clutch F, 4000 hydraulic Circuit, 8000 ECU, 8002 vehicle speed sensor, 8004 shift lever, 8006 position switch, 8008 accelerator pedal, 8010 accelerator opening sensor, 8012 brake pedal, 8014 stroke sensor, 8016 electronic throttle valve, 8018 throttle opening sensor, 8020 engine speed Sensor, 8022 Input shaft rotation speed sensor, 8024 Output shaft rotation Number sensor.

Claims (4)

A vehicle control device including a power source and an automatic transmission connected to the power source, wherein a one-way clutch is interposed in a power transmission path including the automatic transmission, and the one-way clutch Locks when power is input from the input side of the transmission, idles when power is input from the output side of the automatic transmission,
A rotational speed detection means for detecting a rotational speed difference before and after the one-way clutch;
Determination means for determining whether the vehicle is in a wheel spin state based on the detected number of revolutions;
And a control means for controlling the power source so as to reduce the output when it is detected that the wheel spin state is detected.   2. The vehicle control device according to claim 1, wherein the determination unit includes a unit for determining that the vehicle is in a wheel spin state when a variation in the rotation speed difference is large. 3.   3. The vehicle control device according to claim 1, wherein the control means includes means for controlling the power source so as to gradually decrease and reduce the output of the power source. 4.   4. The control device according to claim 1, further comprising means for controlling the power source so as to gradually increase the output after controlling the power source so as to decrease the output. The vehicle control device described in 1.

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