JP2007309449A - Torque control device for automatic transmission - Google Patents

Abstract

Provided is an automatic transmission torque control device capable of reducing a fastening shock and improving responsiveness at the time of starting by an automatic transmission, achieving both of them and not causing discomfort to a driver. There is to do.
When a start acceleration state is determined by a start acceleration determining unit 210, a change amount limit value calculating unit 230 calculates first and second change amount limit values of a target engine torque according to a running state. . The target engine torque calculation means 240 calculates a target engine torque from the required engine torque at the time of start acceleration and the first change amount limit value calculated by the change amount limit value calculation means 230, and the change amount limit switching means 220 After the determined switching timing, the target engine torque is calculated from the required engine torque at the time of start acceleration and the second change amount limit value. The target start clutch torque calculation means 250 calculates a target start clutch torque based on the target engine torque.
[Selection] Figure 2

Description

  The present invention relates to a torque control device for an automatic transmission that controls torque transmitted by the automatic transmission, and more particularly, to a torque control device for an automatic transmission that controls torque when the vehicle starts.

  2. Description of the Related Art In recent years, automatic transmissions that perform shift control by automatically performing shift operation, select operation, and start clutch engagement operation in an automotive manual transmission have been put into practical use.

  As a control operation at the time of starting, when the neutral range (N range) is changed to the drive range (D range) (usually performed by stepping on the brake), the shift position is first switched from the neutral to the first speed. In this state, the starting clutch is still released, and when the brake is released, the engine torque is gradually transmitted to the automatic transmission while the starting clutch is gradually engaged.

  If the accelerator is depressed at the same time as the brake is released, the engine torque will increase significantly. The start clutch actually controls the engagement state (transmission torque) of the start clutch by controlling the position of the start clutch in order to realize the target start clutch torque calculated according to the increase in engine torque. Here, if the start clutch is suddenly engaged, it becomes a shock, and conversely, if the engagement is too slow, the time to acceleration becomes long (responsiveness deteriorates). Further, in the latter case, durability is impaired due to heat generation due to excessive slip of the starting clutch facing.

Therefore, as a conventional clutch control device, an electronic throttle valve closing control, an intake valve closing control, a fuel cut control, or a motor generator is used for the purpose of reducing a load at the time of engagement (engagement) with a clutch corresponding to a starting clutch. A device that performs regenerative control is known (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 2003-170764

  However, the one described in Patent Document 1 is mainly intended to reduce the clutch load when the vehicle starts suddenly immediately after being selected from the N range to the D range. However, the engine torque is controlled even during normal start acceleration that is not sudden acceleration. Therefore, it is necessary to achieve both relaxation of the fastening shock and improvement of responsiveness.

  As a method for controlling the engine torque, there is a method for holding the intake valve constant as described in Patent Document 1. Another method is to reduce the fastening shock by slowing the target engine torque increase by limiting the amount of change to a certain amount of time against the increase in required engine torque due to the accelerator being depressed. Can be considered.

  However, in these methods, it is often difficult to achieve both fastening shock and responsiveness with respect to various start acceleration patterns. If either of them is inferior, the driver is uncomfortable.

  That is, in the conventional method, as described in Patent Document 1, the engine torque is controlled by holding the intake valve constant, or even if the target engine torque increase is controlled by applying a certain restriction during start acceleration, There is a problem that it is difficult to achieve both the engagement shock of the starting clutch and the responsiveness.

  It is an object of the present invention to reduce the fastening shock at the time of starting by an automatic transmission, improve the responsiveness, achieve both, and control the torque of the automatic transmission without causing discomfort to the driver. To provide an apparatus.

(1) In order to achieve the above object, the present invention provides a starting clutch capable of transmitting / cutting a driving force from an engine, a plurality of drive gears provided on an input shaft connected to the starting clutch, and an output A plurality of driven gears that are provided on a shaft, and each of the plurality of drive gears is in a pair of meshing states, and a meshing clutch that selects meshing of the plurality of drive gears and the driven gears according to an operating state. Used in an automatic transmission that transmits engine driving force from the input shaft to the output shaft by meshing the selected drive gear and driven gear, and engaging / disengaging the starting clutch and the meshing clutch of the automatic transmission A control device for an automatic transmission that controls a start acceleration determination means for determining whether or not the vehicle is in a start acceleration state; A change that determines a switching timing for switching at least two kinds of change amount limit values calculated to control the target engine torque by limiting the change amount when it is determined by the means to be in a start acceleration state. A change amount limit value calculating means, a change amount limit value calculating means for calculating a change amount limit value of at least two types of target engine torque according to the running state when the start acceleration determining means determines that the start acceleration state is present, and a start The target engine torque is calculated from the requested engine torque at the time of acceleration and the first change amount limit value calculated by the change amount limit value calculating means, and after the switching timing determined by the change amount limit switching means, Based on the required engine torque at the time of start acceleration and the second change amount limit value calculated by the change amount limit value calculating means, the target Target engine torque calculating means for calculating a Njintoruku, based on the target engine torque calculated by the target engine torque calculating means is obtained by so comprises a target start clutch torque calculation means for calculating a target start clutch torque.
With such a configuration, the fastening shock can be reduced and the responsiveness can be improved at the time of starting by the automatic transmission, so that both are compatible and the driver is not uncomfortable.

  (2) In the above (1), preferably, the change amount limit value calculating means uses at least one of an accelerator opening, a time change in the accelerator opening, a transmission oil temperature, and an estimated road gradient. The change amount limit value of the target engine torque is calculated.

  (3) In the above (1), preferably, the change amount limit switching means is configured such that the elapsed time corresponding to the accelerator opening from start acceleration, the input shaft speed, the output shaft speed, the input shaft speed and the engine speed The switching timing of the target engine torque variation limit value is determined on the basis of at least one parameter of the speed ratio consisting of a number ratio.

  According to the present invention, at the time of starting by the automatic transmission, the fastening shock can be reduced and the responsiveness can be improved, so that both are compatible and the driver is not uncomfortable.

Hereinafter, the configuration and operation of a torque control device for an automatic transmission according to an embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of an automatic transmission system using the torque control device for an automatic transmission according to the present embodiment will be described with reference to FIG.
FIG. 1 is a system diagram showing an overall configuration of an automatic transmission system using a torque control device for an automatic transmission according to an embodiment of the present invention.

  In the engine 5, the throttle opening controller 25 is controlled based on the accelerator opening detected by the accelerator opening sensor 27, the intake air amount that changes in accordance with the intake passage area is detected by the air flow sensor 11, and The engine speed detected by the engine speed sensor 23 is taken into the engine control computer (ECU) 100. The engine control computer (ECU) 100 calculates the fuel injection amount and the ignition timing, and transmits the control signal to the injector 13 and the spark plug 17 to perform the engine control. The injector 13 is provided in the intake manifold 14, and the spark plug 17 is provided in the cylinder 15. A high voltage for ignition is supplied from the ignition coil 16 to the spark plug 17. An idle speed control valve (ISC) 18 is provided in parallel with the throttle opening controller 25 and controls the intake air flow rate when the engine 5 is idling.

  The engine control computer (ECU) 100 uses the throttle opening detected by the throttle sensor 12, the intake air amount detected by the air flow sensor 11, the engine speed detected by the engine speed sensor 23, and the like. Thus, the torque actually generated by the engine 5 is estimated.

  Further, the engine control computer (ECU) 100 calculates a target engine torque according to the operating state, adjusts the intake air amount by the throttle opening controller 25, and adjusts the ignition timing and the fuel injection amount. , Control the driving torque.

  The output of the engine 5 is transmitted from the crankshaft 19 to the input shaft 37 of the automatic transmission 30 via the start clutch 31. The input shaft 37 is provided with a first drive gear 32, a second drive gear 33, a third drive gear 34, a fourth drive gear 35, a fifth drive gear 36, and a reverse drive gear (not shown). The output shaft 46 includes a rotatable first driven gear 41, a second driven gear 42, a third driven gear 43, a fourth driven gear 44, a fifth drive gear 45, and a reverse driven gear (not shown). is set up. The first drive gear 32 and the first driven gear 41 are in mesh with each other and can transmit driving force. Similarly, the second drive gear 33 and the second driven gear 42, the third drive gear 34 and the third driven gear 43, the fourth drive gear 35 and the fourth driven gear 44, the fifth drive gear 36 and the fifth driven gear 45. Although not shown, the reverse drive gear and the reverse drive gear are in mesh with each other and can transmit a driving force.

  The driving force of the first driven gear 41 is transmitted to the output shaft 46 by connecting the first meshing clutch 55 provided on the output shaft 46. On the other hand, the driving force of the second driven gear 42 is also transmitted to the output shaft 46 by connecting the first meshing clutch 55. Here, the first meshing clutch 55 is controlled by the shift actuator 61 and the select actuator 62 based on the control signal of the transmission control computer (TCU) 200 and is operated by the hydraulic pressure supplied through the hydraulic control mechanism 65. In this case, either the first driven gear 41 or the second driven gear 42 is selected and the driving force is transmitted.

  Similarly, the driving force of the third driven gear 43 or the fourth driven gear 44 is transmitted to the output shaft 46 by connecting the second meshing clutch 56 provided on the output shaft 46. Here, the second meshing clutch is also used. 56 selects and connects either the third driven gear 43 or the fourth driven gear 44 based on the control signal of the transmission control computer (TCU) 200.

  The driving force of the fifth driven gear 45 or a reverse drive gear (not shown) is transmitted to the output shaft 46 by connecting a third meshing clutch 57 provided on the output shaft 46. The meshing clutch 57 selects and connects either the fifth driven gear 45 or the reverse driven gear based on the control signal of the transmission control computer (TCU) 200.

  The driving force finally transmitted by the output shaft 46 is from the first drive gear 32 via the first driven gear 41 and the first meshing clutch 55, from the second drive gear 33 to the second driven gear 42, Via the first meshing clutch 55, from the third drive gear 34 via the third driven gear 43 and the second meshing clutch 56, from the fourth drive gear 35 via the fourth driven gear 44 and the second meshing clutch 56 Of the fifth drive gear 36 via the fifth driven gear 45 and the third meshing clutch 57 and those not shown, but from the reverse drive gear via the reverse driven gear and the third meshing clutch 57 , Any one is selected. These combinations are sequentially set to 1st speed, 2nd speed, 3rd speed, 4th speed, 5th speed, and reverse.

  An assist clutch 71 is provided on the input shaft 37, and a seventh drive gear 72 is provided that is rotatable. On the other hand, the output shaft 46 is provided with a seventh driven gear 73, which is controlled by the assist actuator 63 based on the control signal of the transmission control computer (TCU) 200 and is operated by the hydraulic pressure supplied via the hydraulic control mechanism 65. And transmit the driving force.

  A start clutch 31 is provided on the input shaft 37 to transmit or block the driving force of the engine 5. The start clutch 31 is controlled by a start actuator 64 based on a control signal of a transmission control computer (TCU) 200 and is operated by a hydraulic pressure supplied via a hydraulic control mechanism 65.

  The driving force of the output shaft 46 is finally transmitted to the driving wheel 82 via the differential device 81.

  The transmission control computer (TCU) 200 includes an engine speed detected by the engine speed sensor 23, an input shaft speed detected by the input shaft speed sensor 51 provided on the input shaft 37, and an output shaft provided on the output shaft 46. The output shaft rotational speed detected by the rotational speed sensor 52, the transmission oil temperature detected by the oil temperature sensor 66 provided in the hydraulic control mechanism 65, and the drive gear, driven gear, and meshing clutch selected from the above-mentioned ones. Although not shown in the figure, the shift position and the select position divided into patterns based on the combination are detected and captured by providing a shift position sensor and a select position sensor. Although not shown, the start clutch position is detected by a start clutch position sensor provided in the start clutch 31 and is taken in.

  The transmission control computer (TCU) 200 controls the shift actuator 61, the select actuator 62, the assist actuator 63, and the start actuator 64 so as to obtain an optimum driving state from these input signals.

  In this embodiment, the shift actuator 61, the select actuator 62, the assist actuator 63, and the start actuator 64 are hydraulic systems for controlling the hydraulic control mechanism 65. However, each actuator uses an electric motor. It is good.

  Further, the engine control computer (ECU) 100 and the transmission control computer (TCU) 200 constantly exchange control signals with each other. For example, the target engine torque calculated by the transmission control computer (TCU) 200 is used. In order to realize this, a signal for operating the throttle opening controller 25 and the like is transmitted to the engine control computer (ECU) 100.

Next, a method for calculating the starting clutch torque based on the target engine torque in the torque control device for the automatic transmission according to the present embodiment will be described with reference to FIGS.
FIG. 2 is a detailed block diagram of a torque control device for an automatic transmission according to an embodiment of the present invention. In FIG. 2, the same reference numerals as those in FIG. 1 denote the same parts. FIG. 3 is an explanatory diagram of engine torque characteristics stored in advance in a torque control device for an automatic transmission according to an embodiment of the present invention.

  As shown in FIG. 2, a transmission control computer (TCU) 200 includes a start acceleration determination unit 210, a change amount limit switching unit 220, a change amount limit value calculation unit 230, a target engine torque calculation unit 240, and a target start clutch torque calculation. Means 250 are provided. The transmission control computer (TCU) 200 includes an accelerator opening sensor 27, an engine speed sensor 23, a shift position sensor 91, a select position sensor 92, a start clutch position sensor 93, an oil temperature sensor 66, and an input shaft speed sensor 51. , Various detection signals from the output shaft rotational speed sensor 52 and the acceleration sensor 28 and signals from the engine control computer (ECU) 100 are input.

  The start acceleration determination unit 210 determines whether or not the vehicle is in a start acceleration state based on the accelerator opening APS detected by the accelerator opening sensor 27 and the vehicle speed. As a specific method, for example, when it is recognized that the vehicle speed is almost zero and the brake is turned off and the accelerator opening APS is stepped on a predetermined value or more, it is determined that the vehicle is in the acceleration state. The vehicle speed is calculated by multiplying the output shaft rotational speed NO detected by the output shaft rotational speed sensor 52 by a vehicle speed conversion coefficient. It can also be determined from the amount of change in the intake air amount whether the vehicle is in a starting acceleration state. That is, when the amount of change in the intake air amount is greater than or equal to a predetermined value, it can be determined that the vehicle is in a start acceleration state.

  The change amount limit switching means 220 calculates the target engine torque while switching according to the driving conditions, using a change amount limit value calculating means 230 and a target engine torque calculating means 240 described later using two kinds of change amount limit values. Determine the switching timing when going. As will be described later with reference to FIGS. 10 to 13, the switching timing is, for example, when the time set by the timer from the start acceleration corresponding to the accelerator opening APS has elapsed (FIG. 10) or when the accelerator opening APS is reached. When the input shaft rotational speed NI exceeds a predetermined value (FIG. 11), when the output shaft rotational speed NO exceeds a predetermined value according to the accelerator opening APS (FIG. 12), or according to the accelerator opening APS, the speed ratio When e exceeds a predetermined value (FIG. 13), it is determined using at least one condition. Here, the speed ratio e is a ratio (NI / Ne) between the input shaft rotational speed NI and the engine rotational speed Ne.

  The change amount limit value calculating means 230 calculates two types of target engine torque change amount limit values DTEGST1 and DTEGST2 according to the driving conditions. As will be described later with reference to FIGS. 6 to 9, the change amount limit values DTEGST1 and DTEGST2 are the accelerator opening APS (FIG. 6), the time change in the accelerator opening (ΔAPS) (FIG. 7), and the transmission oil. It is determined using parameters such as temperature (FIG. 8) and estimated road gradient (FIG. 9).

  The target engine torque calculation means 240 first calculates the required engine torque.

  Here, calculation of the required engine torque will be described with reference to FIG. FIG. 3 shows engine torque characteristics. When the engine speed is taken on the horizontal axis and the engine torque is taken on the vertical axis, the magnitude of the engine torque changes according to the throttle opening.

  Based on the throttle opening APS corresponding to the driver's accelerator operation and the engine speed Ne detected by the engine speed sensor 23, the target engine torque calculation means 240 is inputted in advance to the transmission control computer (TCU) 200. The required engine torque is calculated from the engine torque characteristics (FIG. 3). The requested engine torque may be such that the transmission control computer (TCU) 200 receives the engine torque uniquely calculated by the engine control computer (ECU) 100. Further, the required engine torque can be calculated from the fuel injection amount and the engine speed.

  Next, the target engine torque calculation means 240 calculates the target engine torque. Originally, the target engine torque should be controlled to be the above-mentioned required engine torque. However, when starting from a stopped state (throttle opening: 0%) by depressing the accelerator greatly, the actual engine torque also changes abruptly, making precise control of the starting clutch transmission torque difficult, and a large shock at the beginning of engagement. Often occurs. On the other hand, the response to the start of clutch engagement with respect to the accelerator operation is also required. Therefore, in the present embodiment, as a first step, the first amount calculated by the change amount limit value calculating unit 230 is focused on improving the response of the engine torque until the start clutch starts to be engaged. The change amount of the target engine torque with respect to the elapsed time is defined by the change amount limit value DTEGST1. The first variation limit value DTEGST1 should be as large as possible, but it is the actual estimated engine torque that determines the target starting clutch torque (transmission torque), which is also delayed in control from the target engine torque (general Therefore, the first change amount limit value DTEGST1 can be arbitrarily set according to the driving conditions. Thereafter, when the switching timing obtained by the change amount limit switching means 220 is reached, the target engine torque calculation means 240 calculates the target engine torque using the second change amount limit value DTEGST2. In this case, the second change amount limit value DTEGST2 is set with an emphasis on reducing the shock at the start of starting clutch engagement.

  Finally, the target start clutch torque calculation means 250 starts the start clutch related to the inertia portion of the start clutch based on the estimated engine torque obtained as a result of engine control based on the target engine torque calculated by the target engine torque calculation means 240. The target starting clutch torque is calculated by subtracting the clutch torque correction amount. The estimated engine torque is realized, for example, by transmitting what is calculated by the engine control computer (ECU) 100 to the transmission control computer (TCU) 200.

  The specific operation of each means 210, 220, 230, 240, 250 will be described with reference to FIGS.

Next, the control contents of the starting clutch torque in the automatic transmission torque control apparatus according to the present embodiment will be described with reference to FIGS.
FIG. 4 is a flowchart showing the control content of the starting clutch torque in the automatic transmission torque control apparatus according to the embodiment of the present invention. FIG. 5 is a timing chart at the time of starting clutch torque control in the automatic transmission torque control apparatus according to the embodiment of the present invention.

  First, in step s10 of FIG. 4, the start acceleration determination unit 210 determines whether or not the vehicle is in a start acceleration state. The starting acceleration determination method is determined from the accelerator opening APS detected by the accelerator opening sensor 27, the vehicle speed, or the like. The start acceleration state is determined, for example, when it is recognized that the vehicle speed is almost zero, the brake is turned off, and the accelerator opening APS is stepped over a predetermined value. If the determination condition is satisfied, the process proceeds to step s20. If the determination condition is not satisfied, the process proceeds to step s80.

  Next, in step s20, the change amount limit value calculating unit 230 calculates a first change amount limit value DTEGST1 of the target engine torque. The first change amount limit value DTEGST1 of the target engine torque is described later with reference to FIGS. 6 to 9, an accelerator opening APS (FIG. 6), a time change (ΔAPS) of the accelerator opening (FIG. 7), and transmission oil. It is determined using at least one of temperature (FIG. 8), estimated road gradient (FIG. 9), and the like.

Next, in step s30, the target engine torque calculation means 240 calculates the target engine torque BTTEGSTA. The calculation is performed by sequentially adding the first change amount limit value DTEGST1 to the target engine torque BTTEGSTA. That is, the calculation according to the following equation (1) is performed.

BTTEGSTA = BTTEGSTA + DTEGST1 (1)

As a result, the change amount limitation shown in the equation (1) is applied so that the gradient of the target engine torque BTTEGSTA becomes relatively large. Thereby, the responsiveness can be improved by raising the engine torque as early as possible in the initial stage of starting acceleration.

  Next, at step s40, the change amount limit switching means 220 determines whether to change the change amount limit value, and proceeds to step s60 when the determination condition is satisfied, and repeats step s30 when the determination condition is not satisfied. As will be described later with reference to FIGS. 10 to 13, for example, when the time set by the timer from the start acceleration corresponding to the accelerator opening APS has elapsed (FIG. 10), or the accelerator is opened. When the input shaft rotational speed NI exceeds a predetermined value according to the degree APS (FIG. 11), when the output shaft rotational speed NO exceeds a predetermined value according to the accelerator opening APS (FIG. 12), or when the accelerator opening APS In response, when the speed ratio e exceeds a predetermined value (FIG. 13), it is determined using at least one condition.

  Next, in step s50, the change amount limit value calculating means 230 calculates a second change amount limit value DTEGST2 of the target engine torque. The second change amount limit value DTEGST2 is also determined using at least one of parameters such as the accelerator opening, the time change in the accelerator opening (ΔAPS), the transmission oil temperature, and the estimated road gradient. Here, the second change amount limit value DTEGST2 is set to a value smaller than the first change amount limit value DTEGST1 (DTEGST2 <DTEGST1).

In step s60, the target engine torque calculation means 240 calculates the target engine torque BTTEGSTA. The calculation is performed by sequentially adding the variation limit value DTEGST2 to the target engine torque BTTEGSTA. That is, the calculation according to the following equation (2) is performed.

BTTEGSTA = BTTEGSTA + DTEGST2 (2)

Here, since the second variation limit value DTEGST2 is set to a value smaller than the first variation limit value DTEGST1 (DTEGST2 <DTEGST1), the change in the target engine torque BTTEGSTA is moderated by the equation (2), At the same time, the changes in the estimated engine torque STEG and the target start clutch torque TTSC are moderated to reduce the shock at the start of the start clutch engagement.

  Further, in step s70, the target starting clutch torque calculation means 250 determines whether or not the target engine torque BTTEGSTA matches the required engine torque TTEGREQ. If they match, the process proceeds to step s80, and if they do not match, step s60 is repeated.

  Finally, in step s80, the target start clutch torque calculating means 250 calculates a target start clutch torque based on the estimated engine torque.

  Next, the operation contents at the time of controlling the target start clutch torque according to the present embodiment will be described with reference to FIG. In FIG. 5, the horizontal axis represents time, the vertical axis in FIG. 5 (A) represents the accelerator opening APS, and the vertical axis in FIG. 5 (B) represents the engine speed Ne and the input shaft speed NI of the transmission. Show. The vertical axis in FIG. 5 (C) indicates the starting clutch position RPSSC, and the vertical axis in FIG. ) And the target starting clutch torque TTSC (broken line), respectively, and FIG. 5 (E) shows the acceleration G in the longitudinal direction of the vehicle. In FIG. 5E, the solid line indicates the case where the present embodiment is applied, and the alternate long and short dash line indicates the acceleration when the present embodiment is not applied.

  In FIG. 5, at time t1, as shown in FIG. 5 (A), when the accelerator opening APS is stepped on more than a predetermined value s1 when the accelerator is started and stepped on at time t2, the required engine torque TTEGREQ is It changes as shown by a thin solid line in FIG. On the other hand, the target engine torque BTTEGSTA is limited in two steps as shown by a thick solid line in FIG. First, from time t1 to ta, the first change amount limit value DTEGST1 is sequentially added to the target engine torque BTTEGSTA as shown in the equation (1) so that the gradient of the target engine torque BTTEGSTA becomes relatively large. . Accordingly, the responsiveness can be improved by raising the engine torque as early as possible in the initial stage of starting acceleration.

  The target engine torque BTTEGSTA is transmitted to the engine control computer (ECU) 100 and controls the engine torque by optimally setting the throttle opening, the fuel injection amount, and the ignition timing.

  By the way, in an automatic transmission that uses a torque converter for power transmission, for example, if the engine torque is raised too early, the engine speed itself will rise greatly due to slipping of the torque converter, and the driver will experience a sense of discomfort. Shock is also likely to occur when fastening. Therefore, so-called delay control is required so that the engine torque is not increased for a predetermined period even when the accelerator is depressed. However, the automatic transmission according to the present embodiment does not use the torque converter, so there is no concern as described above. Rather, it is possible to advance the start timing of the increase in engine speed, which is more consistent with the driver's intention.

  In addition, the magnitude of the first variation limit value DTEGST1 affects both the inclination and the amount of engine speed when the engine speed increases, and this must be determined in consideration of the feeling given to the driver. . This is because when the starting clutch 31 is operated via the hydraulic control mechanism 65, there is generally a slight response delay. If the first variation limit value DTEGST1 is extremely increased, the target engine torque BTTEGSTA is When starting up stepwise, an appropriate first change amount limit value DTEGST1 is required because it is difficult to obtain stable performance for the above control.

  After that, from time ta to time t3, a limit is imposed by the second variation limit value DTEGST2 so that the gradient of the target engine torque BTTEGSTA becomes relatively small, contrary to the time t1 to time ta described above. . As a result, the change in the target engine torque BTTEGSTA is moderated, and at the same time, the changes in the estimated engine torque STEG and the target start clutch torque TTSC are also moderated, thereby realizing shock reduction in the initial stage of engaging the start clutch.

  On the other hand, the engine control computer (ECU) 100 estimates the actual engine torque, and transmits the estimated engine torque STEG (a chain line in FIG. 5D) as a result to the transmission control computer (TCU) 200. To do. Then, the transmission control computer (TCU) 200 calculates a required target start clutch torque TTSC (broken line in FIG. 5D) based on the estimated engine torque STEG.

  After time t3, as shown in FIG. 5 (D), the required engine torque TTEGREQ is almost constant or slightly decreasing with the increase in engine speed. By gradually increasing the clutch torque, the transmission torque of the starting clutch increases, and as shown in FIG. 5 (B), the difference between the engine speed Ne and the input shaft speed NI gradually decreases. Specifically, the rotational speed difference becomes 0 at time t4. Thereafter, when a predetermined time has elapsed after the start clutch has not slipped (rotational speed difference is 0), the start clutch is moved to the fully engaged position at time t5.

  FIG. 5E shows the acceleration G in the longitudinal direction of the vehicle. In the present embodiment, the first change amount limit value DTEGST1 is used so that the gradient of the target engine torque BTTEGSTA becomes relatively large from time t1 to time ta, and the target engine torque BTTEGSTA from time ta to time t3. The second change amount limit value DTEGST2 is used so that the slope of is relatively small. Here, the first change amount limit value DTEGST1> the second change amount limit value DTEGST2. The acceleration G in the longitudinal direction of the vehicle when controlled in this way changes as shown by a thick solid line in FIG.

  On the other hand, when the inclination of the target engine torque BTTEGSTA is made constant from time t1 to time t3, the acceleration G rises at time tc as shown by a one-dot chain line in FIG. It becomes later than the time tb when the acceleration G rises. That is, the responsiveness is better in this embodiment. Further, when the inclination of the target engine torque BTTEGSTA is constant from time t1 to time t3, a large acceleration due to shock occurs near time t3 in FIG. This shock can be avoided.

  As described above, in the present embodiment, the vehicle front and rear G can mitigate the shock (feeling of popping out) at the start of starting clutch engagement, while ensuring the responsiveness by increasing the rise of the vehicle.

  The first change amount limit value DTEGST1 and the second change amount limit value DTEGST2 are at least one of the accelerator opening, the time change in the accelerator opening (ΔAPS), the transmission oil temperature, and the estimated road gradient, respectively. Determine using parameters. Actually, for example, the characteristics shown in FIGS. 6 to 9 are stored in advance in the transmission control computer (TCU) 200.

Next, the variation limit value DTEGST used in the torque control device for an automatic transmission according to the present embodiment will be described with reference to FIGS.
6 to 9 are explanatory diagrams of change amount limit values used in the torque control device of the automatic transmission according to the embodiment of the present invention.

  FIG. 6 shows an example of the first variation limit value DTEGST1 and the second variation limit value DTEGST2 depending on the accelerator opening. Here, the first change amount limit value DTEGST1 (1) and the second change amount limit value DTEGST2 (1) are, for example, the values shown in the figure according to the accelerator opening, and are previously stored in the form of a map or the like. It is stored in a transmission control computer (TCU) 200. The change amount limit value calculating means 230 acquires the corresponding first change amount limit value DTEGST1 (1) and second change amount limit value DTEGST2 (1) from the map according to the input accelerator opening information. . Basically, DTEGST1 (1) ≧ DTEGST2 (1).

  FIG. 7 shows an example of the first change amount limit value DTEGST1 and the second change amount limit value DTEGST2 based on the time change (ΔAPS) of the accelerator opening. Here, the first change amount limit value DTEGST1 (2) and the second change amount limit value DTEGST2 (2) are, for example, values as illustrated in accordance with the time change (ΔAPS) of the accelerator opening. These are stored in advance in the transmission control computer (TCU) 200 in the form of a map or the like. The change amount limit value calculating means 230 obtains a time change from the input accelerator opening, and according to this information, the corresponding first change amount limit value DTEGST1 (2), second change amount limit value DTEGST2 ( 2) is obtained from the map. Basically, DTEGST1 (2) ≧ DTEGST2 (2).

  FIG. 8 shows an example of the first change amount limit value DTEGST1 and the second change amount limit value DTEGST2 depending on the transmission oil temperature. Here, the first change amount limit value DTEGST1 (3) and the second change amount limit value DTEGST2 (3) are, for example, values as illustrated in accordance with the transmission oil temperature, and are preliminarily represented in the form of a map or the like. It is stored in a transmission control computer (TCU) 200. The change amount limit value calculating means 230 acquires the corresponding first change amount limit value DTEGST1 (3) and second change amount limit value DTEGST2 (3) from the map according to the information of the input transmission oil temperature. . Basically, DTEGST1 (3) ≧ DTEGST2 (3).

FIG. 9 shows an example of the first change amount limit value DTEGST1 and the second change amount limit value DTEGST2 due to the estimated road gradient. Here, the first change amount limit value DTEGST1 (4) and the second change amount limit value DTEGST2 (4) are, for example, the values shown in the figure according to the estimated road gradient, and are in advance in the form of a map or the like. It is stored in a transmission control computer (TCU) 200. The change amount limit value calculating means 230 acquires the corresponding first change amount limit value DTEGST1 (4) and second change amount limit value DTEGST2 (4) from the map according to the information of the estimated road gradient. Basically, DTEGST1 (4) ≧ DTEGST2 (4).
As a method for calculating the estimated road gradient, for example, as described in Japanese Patent Laid-Open No. 6-1473014, acceleration is calculated from the vehicle speed, and the road gradient is estimated according to the acceleration, or a part of the vehicle A method of estimating the road gradient from the acceleration detected by the acceleration sensor can be adopted.

  The calculation of the first change amount limit value DTEGST1 and the second change amount limit value DTEGST2 is basically performed based on the accelerator opening or the time change (ΔAPS) of the accelerator opening. The transmission oil temperature and estimated road gradient are supplemented to correct the first variation limit value DTEGST1 and the second variation limit value DTEGST2 calculated by the accelerator opening or the time change in the accelerator opening (ΔAPS). Used. Specifically, the accelerator opening or the time change of the accelerator opening (ΔAPS) and the two-dimensional map of the transmission oil temperature or the estimated road gradient, or the time change of the accelerator opening or the accelerator opening (ΔAPS) The first change amount limit value DTEGST1 and the second change amount limit value DTEGST2 can be calculated by using the three-dimensional map of the transmission oil temperature and the estimated road gradient.

Next, the switching timing (time ta) used in the automatic transmission torque control apparatus according to the present embodiment will be described with reference to FIGS.
FIGS. 10-13 is explanatory drawing of the switching timing used in the torque control apparatus of the automatic transmission by one Embodiment of this invention.

  FIG. 10 shows a case where the switching timing (time ta) is changed over time from start acceleration according to the accelerator opening. That is, as shown in the figure, when the accelerator opening is A1, the accelerator opening is performed so that the switching timing (time ta) is TM1, and when the accelerator opening is A2, the switching timing (time ta) is TM2. The switching timing (time ta) is changed according to the degree. TM1 and TM2 are setting values of the switching timer. The accelerator opening between A1 and A2 can be obtained by interpolation or the like.

  FIG. 11 shows a case where the switching timing (time ta) is changed according to the accelerator opening and the input shaft rotational speed NI. That is, as shown in the figure, when the accelerator opening is A1, the switching input shaft rotational speed NI is NI1, and when the accelerator opening is A2, the accelerator opening is performed so that the switching input shaft rotational speed NI is NI2. The switching input shaft rotational speed NI is changed according to the degree, and when the set switching input shaft rotational speed NI is reached, the first change amount limit value DTEGST1 is switched to the second change amount limit value DTEGST2. The accelerator opening between A1 and A2 can be obtained by interpolation or the like.

  FIG. 12 shows a case where the switching timing (time ta) is changed according to the accelerator opening and the output shaft rotational speed NO. That is, as shown in the figure, when the accelerator opening is A1, the switching output shaft rotational speed NO is NO1, and when the accelerator opening is A2, the accelerator opening is performed so that the switching output shaft rotational speed NO is NO2. The switching output shaft rotational speed NO is changed according to the degree, and when the set switching output shaft rotational speed NO is reached, the first change amount limit value DTEGST1 is switched to the second change amount limit value DTEGST2. The accelerator opening between A1 and A2 can be obtained by interpolation or the like.

  FIG. 13 shows a case where the switching timing (time ta) is changed according to the accelerator opening and the speed ratio e. Here, the speed ratio is a ratio (NI / Ne) between the input shaft speed NI and the engine speed Ne. That is, as shown in the figure, when the accelerator opening is A1, the switching speed ratio e is e1, and when the accelerator opening is A2, the switching speed ratio e is e2. Then, the switching speed ratio e is changed, and when the set switching speed ratio e is reached, the first change amount limit value DTEGST1 is switched to the second change amount limit value DTEGST2. The accelerator opening between A1 and A2 can be obtained by interpolation or the like.

  In any case of FIGS. 10 to 13, the start clutch 31 is switched from the disengaged state to the moment when the engagement is slightly started. 10 to 13, it is the input shaft rotational speed NI (FIG. 11) or the speed ratio e (FIG. 13) that makes it easy to grasp the released / engaged state of the starting clutch 31.

  In the above-described example, the start clutch 31 can be applied to either a dry type or a wet type, and the type of transmission is not limited to the type of the present invention, and can be applied to, for example, a so-called twin clutch transmission. It is.

  Further, although the target engine torque variation limit value is switched to two stages, it is also possible to provide switching timings in multiple stages, and control between different switching timings with different variation limit values.

As described above, according to the present embodiment, the target engine torque is controlled by providing a change amount limit, and this change amount limit is used for the control region with a focus on ensuring responsiveness, and for reducing the fastening shock. By controlling the target engine torque and the target start clutch torque by dividing the control area into two main areas, both responsiveness improvement and shock reduction can be achieved.

1 is a system diagram showing an overall configuration of an automatic transmission system using a torque control device for an automatic transmission according to an embodiment of the present invention. 1 is a detailed block diagram of a torque control device for an automatic transmission according to an embodiment of the present invention. FIG. It is explanatory drawing of the engine torque characteristic previously stored in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is a flowchart which shows the control content of the starting clutch torque in the torque control apparatus of the automatic transmission by one Embodiment of this invention. 6 is a timing chart at the time of starting clutch torque control in the automatic transmission torque control device according to the embodiment of the present invention; It is explanatory drawing of the variation | limiting amount limit value used in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is explanatory drawing of the variation | limiting amount limit value used in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is explanatory drawing of the variation | limiting amount limit value used in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is explanatory drawing of the variation | limiting amount limit value used in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is explanatory drawing of the switching timing used in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is explanatory drawing of the switching timing used in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is explanatory drawing of the switching timing used in the torque control apparatus of the automatic transmission by one Embodiment of this invention. It is explanatory drawing of the switching timing used in the torque control apparatus of the automatic transmission by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 ... Engine 11 ... Air flow sensor 12 ... Throttle sensor 13 ... Injector 14 ... Intake manifold 15 ... Cylinder 16 ... Ignition coil 17 ... Spark plug 18 ... Idle speed control valve (ISC)
DESCRIPTION OF SYMBOLS 19 ... Crankshaft 23 ... Engine speed sensor 25 ... Throttle opening controller 27 ... Accelerator opening sensor 30 ... Automatic transmission 31 ... Starting clutch 32 ... 1st drive gear 33 ... 2nd drive gear 34 ... 3rd drive gear 35 ... 4th drive gear 36 ... 5th drive gear 37 ... Input shaft 41 ... 1st driven gear 42 ... 2nd driven gear 43 ... 3rd driven gear 44 ... 4th driven gear 45 ... 5th driven gear 46 ... Output shaft DESCRIPTION OF SYMBOLS 51 ... Input shaft rotational speed sensor 52 ... Output shaft rotational speed sensor 55 ... 1st meshing clutch 56 ... 2nd meshing clutch 57 ... 3rd meshing clutch 61 ... Shift actuator 62 ... Select actuator 63 ... Assist actuator 64 ... Start actuator 65 ... Hydraulic control mechanism 66 ... Oil temperature sensor 71 ... Reed Strut 72 ... 7th drive gear 73 ... 7th driven gear 81 ... Differential gear 82 ... Drive wheel 100 ... Engine control computer (ECU)
200 ... Transmission control computer (TCU)
210 ... Start acceleration determination means 220 ... Change amount restriction switching means 230 ... Change amount restriction value calculation means 240 ... Target engine torque calculation means 250 ... Target start clutch torque calculation means

Claims (3)

A starting clutch capable of transmitting and interrupting the driving force from the engine;
A plurality of drive gears provided on an input shaft connected to the starting clutch;
A plurality of driven gears provided on the output shaft and each of the plurality of drive gears in a pair of meshing states;
A meshing clutch for selecting meshing between the plurality of drive gears and the driven gear according to an operating state;
Used in an automatic transmission that transmits engine driving force from the input shaft to the output shaft by meshing the selected drive gear and driven gear;
A control device for an automatic transmission that controls engagement / release of a starting clutch of the automatic transmission and the engagement clutch,
Start acceleration determining means for determining whether or not the vehicle is in a start acceleration state;
Switching timing for switching at least two kinds of change amount limit values calculated to control the target engine torque with a change amount limit when the start acceleration determining unit determines that the vehicle is in the start acceleration state. Change amount limit switching means for determining,
A change amount limit value calculating means for calculating a change amount limit value of at least two types of target engine torques according to the running state when the start acceleration determining unit determines that the vehicle is in a start acceleration state;
The target engine torque is calculated from the required engine torque at the time of starting acceleration and the first change amount limit value calculated by the change amount limit value calculating means, and after the switching timing determined by the change amount limit switching means. Target engine torque calculating means for calculating a target engine torque from the required engine torque at the time of starting acceleration and the second change amount limit value calculated by the change amount limit value calculating means;
A torque control device for an automatic transmission, further comprising target start clutch torque calculation means for calculating a target start clutch torque based on the target engine torque calculated by the target engine torque calculation means. The torque control device for an automatic transmission according to claim 1,
The change amount limit value calculation means calculates the target engine torque change limit value using at least one of an accelerator opening, a time change in the accelerator opening, a transmission oil temperature, and an estimated road gradient. A torque control device for an automatic transmission. The torque control device for an automatic transmission according to claim 1,
The change amount limit switching means is at least one of an elapsed time corresponding to the accelerator opening from start acceleration, an input shaft speed, an output shaft speed, and a speed ratio comprising a ratio of the input shaft speed and the engine speed. A torque control apparatus for an automatic transmission, wherein the switching timing of the target engine torque variation limit value is determined based on the above parameters.

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