JP2015098892A - Vehicle drive control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle drive control device capable of suppressing the occurrence of belt slip in a transmission.SOLUTION: In a drive control device, an ECU executes a clutch engagement control for engaging a clutch from a deceleration S&S control. In this case, if an actual turbine rotational speed NT that is a measured value of a rotational speed of an engine-side input engagement member of the clutch is lower than a target turbine rotational speed NTTGT that is a target value of the rotational speed by a predetermined value α (Yes in Step S102), the ECU executes a first compression pressure correction control for adding a correction amount ΔP1 based on a difference between an inertial torque of the clutch calculated from the target turbine rotational speed NTTGT and an inertial torque of the clutch calculated from the actual turbine rotational speed NT to a commanded compression pressure Pd that is command value for a compression pressure of the transmission (Step S103).

Description

  The present invention relates to a vehicle drive control device.

  Conventionally, in order to improve the fuel efficiency of a vehicle, for example, the engine is stopped and the clutch is released while the vehicle is decelerating or traveling at a constant speed, for example, and the power transmission between the engine and the drive wheels is interrupted to inertia. There is known coasting control for coasting that causes a vehicle to travel. For example, Patent Document 1 discloses a configuration that performs the coasting control in a vehicle drive control device that includes a belt-type continuously variable transmission (CVT) as a transmission.

JP 2013-108593 A

  At the time of return from coasting control, the released clutch is engaged, and the driving force is transmitted to the driving wheel to re-accelerate. At this time, in the configuration including the belt-type continuously variable transmission as in Patent Document 1, the clamping pressure of the belt-type continuously variable transmission is also controlled during the clutch engagement control. The actual pressure may be output above the command pressure. In this case, torque exceeding the torque capacity of the transmission is input from the clutch to the transmission, and belt slippage may occur in the transmission.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a vehicle drive control device capable of suppressing the occurrence of belt slippage of a transmission during execution of clutch engagement control. .

  In order to solve the above-described problems, a vehicle drive control device according to the present invention includes an engine, a belt-type continuously variable transmission that shifts power of the engine and transmits the power to drive wheels, the engine, and the drive wheels. And a control means for controlling the operation of the engine, the clutch, and the continuously variable transmission, and the control means opens and closes the clutch while the vehicle is running. Engagement that engages the clutch from the coasting control by performing coasting control that stops the engine, cuts off power transmission between the engine and the drive wheels, and causes the vehicle to travel by inertia When the control is performed, the actual value of the rotation speed of the engagement member on the engine side of the clutch is less than a predetermined value with respect to the target value of the rotation speed, and is calculated from the target value. Crap The first clamping pressure correction control is performed in which a correction amount based on the difference between the inertia torque of the clutch and the inertia torque of the clutch calculated from the actual measurement value is added to the command value of the clamping pressure of the continuously variable transmission. It is characterized by.

  In the vehicle drive control device, the control means may provide a correction amount based on the maximum value of the inertia torque when the descending slope of the actual measurement value is steeper than a predetermined slope. It is preferable to implement second clamping pressure correction control that is added to the command value of the clamping pressure.

  Further, in the vehicle drive control device, the control means may perform the second operation when the change in the actual measurement value is stagnant during the first clamping pressure correction control and the second clamping pressure correction control. It is preferable to end the clamping pressure correction control.

  In the vehicle drive control device, the control means may perform the measurement when the measured value increases toward the target value during the first clamping pressure correction control and the second clamping pressure correction control. Preferably, the first clamping pressure correction control and the second clamping pressure correction control are terminated.

  Further, in the vehicle drive control device, in the first narrow pressure correction control, an actual measurement value of the number of rotations of the engagement member on the engine side of the clutch may cause belt slip in the continuously variable transmission. The inertia torque of the clutch calculated from the target value when the torque is lower than the target value of the rotational speed up to the rotational speed in a situation where the torque is transmitted from the clutch to the continuously variable transmission, and the actual measurement It is preferable that a correction amount based on a difference from the clutch inertia calculated from the value is added to a command value of the clamping pressure of the continuously variable transmission.

  In the vehicle drive control device according to the present invention, when the measured value of the rotational speed of the engagement member on the engine side of the clutch is lower than a predetermined value with respect to the target value of the rotational speed, the clamping pressure of the continuously variable transmission is By adding the correction amount to the command value, it is possible to suppress the occurrence of belt slippage in the transmission during the clutch engagement control.

FIG. 1 is a schematic configuration diagram illustrating a vehicle drive control apparatus according to an embodiment of the present invention. FIG. 2 is a time chart showing the clutch engagement control and the pinching pressure correction control that are performed when returning from the deceleration S & S control in the present embodiment. FIG. 3 is a flowchart showing the clamping pressure correction control that is performed at the time of return from the deceleration S & S control in the present embodiment. FIG. 4 is a flowchart showing the clamping pressure correction control release process in the present embodiment. FIG. 5 is a time chart showing the release process when the change in the actual turbine rotation speed is stagnated by the clamping pressure correction control. FIG. 6 is a time chart showing a release process when the actual turbine speed is increased by the clamping pressure correction control.

  Hereinafter, an embodiment of a vehicle drive control device according to the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

[Embodiment]
First, with reference to FIG. 1, the structure of the drive control apparatus 1 of the vehicle 100 which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic configuration diagram illustrating a vehicle drive control apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the drive control device 1 according to this embodiment is mounted on a vehicle 100. The vehicle 100 includes an engine 2, a torque converter 3, a clutch 4, a transmission 5, a deceleration / differential mechanism 6, drive wheels 7, and an ECU (electronic control unit) 8. The power output from the engine 2 is input to the transmission 5 via the torque converter 3 and the clutch 4, and is transmitted from the transmission 5 to the drive wheels 7 via the deceleration / differential mechanism 6. Thus, a power transmission path is formed between the engine 2 and the drive wheel 7. A drive control device 1 according to the present embodiment includes an engine 2, a torque converter 3, a clutch 4, a transmission 5, and an ECU 8 (control means).

  The engine 2 is a power source of the vehicle 100, and can convert the combustion energy of the fuel into the rotational motion of the crankshaft (output shaft) 9 and output it. The torque converter 3 is a fluid transmission device that is connected to the engine 2 and transmits power output from the engine 2 via oil (working fluid), and includes a pump impeller 3a and a turbine runner 3b. The pump impeller 3 a is connected to the crankshaft 9 of the engine 2, and the turbine runner 3 b is connected to the clutch 4 and the connecting shaft 10. Accordingly, the rotation (engine rotation speed Ne) input from the engine 2 to the pump impeller 3a is transmitted to the turbine runner 3b via the working fluid, and the rotation speed (turbine rotation speed Nt) output from the turbine runner 3b is connected. Input to the clutch 4 through the shaft 10.

  The clutch 4 has a function of connecting / disconnecting power transmission between the engine 2 and the drive wheel 7. The clutch 4 is a friction engagement type clutch device, and is disposed between the torque converter 3 and the transmission 5 on the power transmission path. The clutch 4 has an input side (engine 2 side) engaging member 4a and an output side engaging member 4b. The input side engaging member 4 a is connected to the turbine runner 3 b by the connecting shaft 10, and the output side engaging member 4 b is connected to the transmission 5. The clutch 4 can connect power transmission between the engine 2 and the drive wheel 7 by engaging the input side engaging member 4a and the output side engaging member 4b. The clutch 4 can cut off power transmission between the engine 2 and the drive wheels 7 by opening the input side engaging member 4a and the output side engaging member 4b.

  The transmission 5 has a function of shifting the power output from the engine 2 via the torque converter 3. The transmission 5 is disposed between the clutch 4 and the speed reduction / differential mechanism 6 on the power transmission path. Specifically, the transmission 5 is a belt-type continuously variable transmission (CVT), and includes a primary pulley 11, a secondary pulley 12, and a belt 13. The primary pulley 11 has a primary movable sheave 11a and a primary fixed sheave 11b. The secondary pulley 12 has a secondary movable sheave 12a and a secondary fixed sheave 12b. Then, a substantially V-shaped primary groove formed between the primary movable sheave 11a and the primary fixed sheave 11b, and a substantially V-shaped secondary groove formed between the secondary movable sheave 12a and the secondary fixed sheave 12b. Between the two, an endless belt 13 is wound around. In the transmission 5, power is transmitted from the primary pulley 11 to the secondary pulley 12 via the belt 13. The rotation shaft of the primary pulley 11 is connected to the output side engaging member 4 b of the clutch 4, and the rotation shaft of the secondary pulley 12 is connected to the input shaft of the speed reduction / differential mechanism 6.

  The transmission ratio of the transmission 5 is a value obtained by dividing the rotational speed (Nin) of the primary pulley 11 on the input side by the rotational speed of the secondary pulley 12 on the output side. That is, the gear ratio of the transmission 5 corresponds to the rotational speed ratio between the primary pulley 11 and the secondary pulley 12. This rotational speed ratio is determined according to the ratio of the rotational radius (belt hooking diameter) of the belt 13 between the primary pulley 11 and the secondary pulley 12. The belt engagement diameters of the primary pulley 11 and the secondary pulley 12 are determined by the groove width of the primary groove and the groove width of the secondary groove, respectively. Therefore, the transmission 5 can change the gear ratio steplessly by changing the groove width of the primary groove and the groove width of the secondary groove.

  The operations of the clutch 4 and the transmission 5 are controlled by hydraulic pressure supplied by a hydraulic control device (not shown). The hydraulic control device supplies hydraulic pressure for operating the engagement member of the clutch 4 to the clutch 4. The hydraulic control device can control the engagement / disengagement of the clutch 4 and the degree of engagement by adjusting the hydraulic pressure (clutch hydraulic pressure) supplied to the clutch 4 in accordance with a control command from the ECU 8. . Further, the hydraulic control device supplies the transmission 5 with hydraulic pressure for operating the primary movable sheave 11 a and the secondary movable sheave 12 a (hereinafter also referred to as “secondary sheave 12 a”) of the transmission 5. The hydraulic control device adjusts the groove width of the primary groove of the primary pulley 11 and the groove width of the secondary groove of the secondary pulley 12 by adjusting the hydraulic pressure supplied to the transmission 5 in accordance with a control command from the ECU 8. Thus, the gear ratio of the transmission 5 can be controlled. Further, the hydraulic control device adjusts the pressure (clamping pressure) at which the primary pulley 11 and the secondary pulley 12 pinch the belt 13 by adjusting the hydraulic pressure supplied to the transmission 5 in accordance with a control command from the ECU 8. Thus, the torque capacity of the primary pulley 11 and the secondary pulley 12 can be controlled.

  The speed reduction / differential mechanism 6 connects the rotating shaft of the secondary pulley 12 of the transmission 5 and the drive wheel 7, and has a speed reduction mechanism and a differential mechanism based on a combination of gears. Accordingly, the rotation input from the transmission 5 is decelerated by the deceleration / differential mechanism 6 and distributed to the left and right drive wheels 7.

  The ECU 8 controls each part of the vehicle 100 such as the engine 2, the torque converter 3, the clutch 4, the transmission 5, and the like based on the operation state of the engine 2 by the driver and the operating state of the engine 2. Control comprehensively.

  In the present embodiment, the ECU 8 can execute deceleration S & S (stop and start) control by controlling each part of the vehicle 100. In the deceleration S & S control, the engine 2 is automatically stopped during deceleration of the vehicle 100 in order to improve fuel efficiency. In the deceleration S & S control, the clutch 4 is released when the engine 2 is stopped in order to suppress shock transmission due to the stop of the engine 2. In other words, the deceleration S & S control means that the vehicle 4 is disengaged while the vehicle 100 is decelerated and the power transmission between the engine 2 and the transmission 5 is interrupted and the vehicle 100 is stopped with the engine 2 stopped. It is intended for inertial running. This deceleration S & S control can improve fuel consumption by stopping fuel consumption in the engine 2.

  When the engine automatic stop condition (for example, the driver does not depress the accelerator pedal for a predetermined time) while the vehicle 100 is traveling, the ECU 8 releases the clutch 4 and automatically stops the engine 2 to decelerate S & S. Execute control. When the ECU 8 automatically stops the engine 2, fuel supply to the engine 2 and ignition are stopped. Further, the ECU 8 engages the clutch 4 and restarts the engine 2 to restart the deceleration S & S when an automatic engine start condition (for example, depression of the accelerator pedal by the driver) is satisfied during execution of the deceleration S & S control. Return from control.

  In the present embodiment, the ECU 8 can execute the clutch engagement control when returning from the deceleration S & S control. In general, the hydraulic pressure is supplied to the clutch 4 and the transmission 5 by a mechanical pump (not shown) that rotates in synchronization with the crankshaft during the operation of the engine 2. That is, the mechanical pump generates hydraulic pressure using the driving force of the engine 2, and the hydraulic pressure is adjusted via the hydraulic control circuit and supplied to the clutch 4 and the transmission 5. On the other hand, when the engine 2 is stopped, hydraulic pressure is supplied using an electric pump (not shown) instead of the mechanical pump. However, since the efficiency of the electric pump is inferior to that of the mechanical pump, the supply pressure remains at a minimum pressure to prevent fuel consumption deterioration. Therefore, when the engine 2 is restarted when returning from the deceleration S & S control, the increase in the output hydraulic pressure (line pressure) of the mechanical pump is slow, and the secondary sheave 12a of the transmission 5 has a large required flow rate. The pinching pressure of the pulley 12 may not be output as instructed.

  At this time, when the clutch 4 is engaged, the clutch 4 transmits torque greater than the torque capacity of the secondary sheave 12 a to the transmission 5, and therefore there is a possibility that the belt 13 slips in the transmission 5. . Therefore, in the present embodiment, the ECU 8 applies the clutch 4 to the clutch 4 so that the transmission torque (clutch torque) of the clutch 4 is equal to or less than the torque capacity of the secondary sheave 12a of the transmission 5 when returning from the deceleration S & S control. Clutch engagement control for controlling the supply hydraulic pressure is executed.

The clutch engagement control is based on a physical formula expressed by the following formula (1).

  In the above physical formula, “input torque TT” is torque (power) output from the engine 2 and input to the input side engaging member 4 a of the clutch 4 via the torque converter 3. The “inner torque” is a loss torque necessary for rotating the input side engaging member 4a and the output side engaging member 4b of the clutch 4. As shown in the above physical formula, the inertia torque includes the rotational inertia moment I and the turbine rotational speed Nt (the input side engaging member 4a of the clutch 4 coupled to the turbine runner 3b of the torque converter 3 via the coupling shaft 10). The number of revolutions) and the differential value are obtained. “Clutch torque TC” is a transmission torque capacity that the clutch 4 can transmit to the downstream side of the power transmission path, that is, to the transmission 5 (hereinafter also referred to as “clutch torque capacity”).

  In the clutch engagement control, the clutch torque TC is determined by removing the inertia torque based on the target turbine speed NTTGT as a loss from the input torque TT based on the above equation (1). Then, the clutch torque TC is converted into a clutch hydraulic pressure to be supplied to the clutch 4, and the engagement operation of the clutch 4 is controlled based on the derived clutch hydraulic pressure. Here, the “target turbine rotational speed NTTGT” is a target value of the turbine rotational speed Nt. The input torque TT can be derived based on information related to the operating state of the engine 2, such as the engine speed Ne.

Further, during the clutch engagement control, based on the clutch torque capacity (clutch torque TC) determined as described above, the torque capacity of the secondary sheave 12a of the transmission 5 is equal to or greater than the clutch torque capacity. The clamping pressure of the secondary sheave 12a is controlled. Specifically, the pinching pressure Pd of the secondary sheave 12a of the transmission 5 required to make the torque capacity of the secondary sheave 12a of the transmission 5 equal to or greater than the clutch torque capacity is calculated by the following equation (2).

  Here, Tin represents the clutch torque capacity TC calculated by the equation (1). A is a sheave angle (°) of the secondary sheave 12a, AOUT is a pressure receiving area of the secondary sheave 12a, Rin is a belt engagement diameter of the secondary sheave 12a, and μ is a friction coefficient between the belt 13 and the secondary sheave 12a. The ECU 8 controls the clamping pressure of the secondary sheave 12a by adjusting the hydraulic pressure supplied to the secondary sheave 12a based on the command value of the clamping pressure Pd thus derived (hereinafter also referred to as “instruction clamping pressure Pd”). To do.

  With reference to FIG. 2, the clutch engagement control at the time of return from the deceleration S & S control will be further described. FIG. 2 is a time chart showing the clutch engagement control and the pinching pressure correction control that are performed when returning from the deceleration S & S control in the present embodiment. In the time chart of FIG. 2, time transitions of the rotation speed (rpm) and the hydraulic pressure (MPa) are shown. As the rotational speed, an engine rotational speed Ne, a target turbine rotational speed NTTGT, and an actual turbine rotational speed NT are shown. Here, the actual turbine speed NT is an actual measurement value of the turbine speed. As the hydraulic pressure, the indicated clamping pressure Pd of the secondary sheave 12a is shown.

  At the beginning of this time chart, the vehicle 100 is executing deceleration S & S control, the engine 2 is stopped, and the clutch 4 is released.

  At time t1, an engine automatic start condition is satisfied, and engine start control for restarting the engine 2 is started to return from deceleration S & S control, and then clutch engagement control is started at time t2. During the engine start control, since the change in the starting torque of the engine 2 is large, the target turbine rotational speed NTTGT is not controlled to the linear shape, but is controlled by the target speed ratio (target turbine rotational speed NTTGT / engine rotational speed Ne). . Then, at the time t3, after the engine start control is completed and the influence of the starting torque is lost, the sweep-down control is performed to sweep down the turbine rotation speed Nt at a constant level (gradual change). In the sweep down control, the target turbine rotational speed NTTGT is swept down to cause the actual turbine rotational speed NT to follow this.

  During the clutch engagement control after time t2, the clutch torque capacity TC is calculated from the above equation (1) using the target turbine speed NTTGT set by the target speed ratio control and the sweep down control. The clutch engagement is controlled based on the calculated clutch torque capacity TC. Further, the command clamping pressure Pd of the secondary sheave 12a is calculated from the above equation (2) using the calculated clutch torque capacity TC, and the clamping pressure of the secondary sheave 12a is controlled based on the calculated command clamping pressure Pd.

  Here, as described above, the command clamping pressure Pd of the secondary sheave 12a of the transmission 5 is calculated according to the command hydraulic pressure (clutch torque capacity TC) to the clutch 4. However, for example, when the identification of the hydraulic model is bad or the indicated hydraulic pressure fluctuates up and down, the response of the actual hydraulic pressure (actual clutch hydraulic pressure) supplied to the clutch 4 is delayed and the phase is shifted from the indicated hydraulic pressure. May occur. In such a situation, the actual clutch hydraulic pressure may be output higher than the command hydraulic pressure. In such a case, since more torque than expected is input from the clutch 4 to the transmission 5, the pinching pressure is insufficient and the belt 13 may slip. On the other hand, in the transmission 5, if the pinching pressure is excessively increased from the beginning in order to prevent belt slippage, there is a possibility that transmission efficiency deteriorates and belt durability is adversely affected.

  Therefore, in the present embodiment, the actual clutch torque is larger than the calculated clutch torque capacity TC when the actual turbine speed NT is significantly lower than the predetermined value α (see FIG. 3) with respect to the target turbine speed NTTTGT. It is determined that there is a possibility that the torque capacity of the transmission 5 may be exceeded, and control for adding the correction amount ΔP1 to the command clamping pressure Pd to the secondary sheave 12a is performed. This correction amount ΔP1 is calculated based on the difference between the inertia torque calculated from the target turbine speed NTGT and the inertia torque calculated from the actual turbine speed NT. Hereinafter, this control is referred to as “first clamping pressure correction control”.

  Furthermore, in the present embodiment, when the descending gradient of the actual turbine speed NT rises above a certain level, the clutch 4 is gripped more than expected (the degree of engagement is too strong), and the change of the inertia torque becomes faster. Therefore, it is determined that there is a possibility that belt slip cannot be suppressed by the first clamping pressure correction control, and the correction amount ΔP2 based on the predetermined maximum inertia torque is further added to the command clamping pressure Pd + ΔP1 to the secondary sheave 12a. Implement additional control. The “maximum inertia torque” is the maximum value of the inertia torque that can be generated in the clutch 4, and is based on the response of the clutch pressure that can be output by the hydraulic circuit (for example, the maximum fluctuation amount of the turbine speed Nt that the clutch 4 can take). Can be obtained experimentally. The “correction value based on the maximum inertia torque” is a correction value of the clamping pressure necessary to increase the torque capacity corresponding to the maximum inertia torque by the secondary sheave 12a. Hereinafter, this control is referred to as “second clamping pressure correction control”. “First clamping pressure correction control” and “second clamping pressure correction control” are also collectively referred to as “nip pressure correction control”.

  These clamping pressure correction controls will be described with reference to FIG. 3 in addition to the time chart of FIG. FIG. 3 is a flowchart showing the clamping pressure correction control that is performed at the time of return from the deceleration S & S control in the present embodiment. The process shown in the flowchart of FIG. 3 is performed by the ECU 8 at predetermined intervals, for example, when returning from the deceleration S & S control. Hereinafter, the clamping pressure correction control will be described with reference to the flowchart of FIG.

  In step S101, it is determined whether or not the clutch engagement control at the time of return from the deceleration S & S control is being performed. If clutch engagement control is being performed (Yes in S101), the process proceeds to step S102, and if not (No in S101), this control flow is terminated. In the time chart of FIG. 2, the clutch engagement control is performed after time t2, and the process proceeds to step S102 in the case of time t2 or later.

  In step S102, it is determined whether or not the target turbine rotational speed NTTGT and the actual turbine rotational speed NT are different from each other by a predetermined value α, that is, whether or not the condition of NTTGT−NT> α is satisfied. As described above, the target turbine speed NTTGT is individually set by the target speed ratio control and the sweep down control that are performed during the clutch engagement control. The actual turbine rotational speed NT can be obtained by measuring the rotational speed of the connecting shaft 10, for example, by measuring means (not shown). The predetermined value α is, for example, a value relative to the target turbine rotational speed NTTGT, up to the rotational speed in a state where the actual turbine rotational speed NT is transmitted to the transmission 5 from the clutch 4 so that the belt 5 can cause belt slippage. It is set so that the situation will be lower. When the condition of NTTGT-NT> α is satisfied (Yes in S102), the actual turbine speed NT is significantly lower than the predetermined value α with respect to the target turbine speed NTGT, and belt slip is caused on the transmission 5. Since it can be determined that the torque that can be generated is transmitted from the clutch 4 to the transmission 5, the process proceeds to step S103. On the other hand, when the above condition is not satisfied (No in S102), the deviation between the actual turbine speed NT and the target turbine speed NTGTGT is within a predetermined value α and is transmitted from the clutch 4 to the transmission 5. Since it can be determined that the torque is less than or equal to the torque capacity of the transmission 5, the present control flow ends. In the time chart of FIG. 2, it is determined that the above condition is satisfied at time t4 after the transition to the sweep-down control.

In step S103, as a result of the determination in step S102, it is determined that the actual turbine rotational speed NT is significantly lower than the target turbine rotational speed NTTGT, and the first clamping pressure correction control is performed. In the first clamping pressure correction control, the clamping pressure correction amount ΔP1 for compensating for the difference between the inertia torque calculated from the target turbine speed NTGT and the inertia torque calculated from the actual turbine speed NT is the secondary sheave 12a. It is added to the indicated clamping pressure Pd. This correction amount ΔP1 is calculated by the following equation (3).

  In the above equation (3), the difference between the inertia torque calculated from the target turbine rotational speed NTTGT and the inertia torque calculated from the actual turbine rotational speed NT is expressed by the pressure receiving area AOUT of the secondary sheave 12a and the belt engagement diameter Rin. By dividing and converting to pressure, the correction amount ΔP1 of the clamping pressure is calculated. Based on the command clamping pressure Pd + ΔP1 to which the correction amount ΔP1 calculated in this way is added, the hydraulic pressure supplied to the secondary sheave 12a is controlled. When the process of step S103 is completed, the process proceeds to step S104. In the time chart of FIG. 2, the first clamping pressure correction control is started at time t4, and the correction amount ΔP1 calculated in this step is added to the command clamping pressure Pd.

  In step S104, it is determined whether or not the descending gradient of the actual turbine speed NT is greater than or equal to a predetermined value. “The descending gradient of the actual turbine rotational speed NT is equal to or greater than a predetermined value” means that the actual turbine rotational speed NT is reduced in the situation where the actual turbine rotational speed NT decreases as the target turbine rotational speed NTGTGT decreases during the sweep down control. It can also be expressed as a situation in which the decrease speed is greater than or equal to a predetermined speed and the actual turbine speed NT is rapidly decreasing, and it can also be expressed as a situation in which the descending gradient of the actual turbine speed NT is steeper than a predetermined gradient. Can do. If the descending gradient of the actual turbine speed NT is greater than or equal to a predetermined value (Yes in S104), it is determined that the correction of the clamping pressure cannot be sufficiently performed only by the first clamping pressure correction control in Step S103, and the process proceeds to Step S105. On the other hand, when the descending gradient of the actual turbine rotational speed NT is within the predetermined range (No in S104), this control flow ends. In the time chart of FIG. 2, it is determined that the descending gradient of the actual turbine rotational speed NT is equal to or greater than a predetermined value at time t5 after the instruction clamping pressure Pd is added by the correction amount ΔP1.

  It should be noted that the situation where “the descending gradient of the actual turbine speed NT is not less than a predetermined value” in step S104 is considered to be a situation in which the relative reduction speed of the actual turbine speed NT with respect to the target turbine speed NTTTGT is not less than the predetermined speed. Also good.

  In step S105, as a result of the determination in step S104, the second clamping pressure correction control is performed when it is determined that the descending gradient of the actual turbine speed NT is equal to or greater than a predetermined value. In the second clamping pressure correction control, the correction amount ΔP2 corresponding to the maximum inertia torque is added to the command clamping pressure Pd + ΔP1 of the secondary sheave 12a. The correction amount ΔP2 corresponding to the maximum inertia torque can be acquired in advance by the following procedure, for example. That is, (i) the maximum fluctuation amount of the turbine speed Nt that can be taken by the clutch 4 is experimentally obtained in advance, and (ii) the maximum fluctuation amount is multiplied by the rotational inertia moment I in the same manner as the above equation (1). By calculating the maximum inertia torque and (iii) dividing the maximum inertia torque by the pressure receiving area AOUT of the secondary sheave 12a and the belt hooking diameter Rin in the same manner as the above equation (3), A correction amount ΔP2 is calculated. Based on the command clamping pressure Pd + ΔP1 + ΔP2 to which the correction amount ΔP2 calculated in this way is added, the hydraulic pressure supplied to the secondary sheave 12a is controlled. When the process of step S105 is completed, this control flow ends. In the time chart of FIG. 2, the second clamping pressure correction control is started at time t5, and the correction amount ΔP2 calculated in this step is added to the command clamping pressure Pd + ΔP1.

  Next, with reference to FIGS. 4 to 6, the above described clamping pressure correction control canceling process will be described. FIG. 4 is a flowchart showing the canceling process of the clamping pressure correction control in the present embodiment, and FIG. 5 is a time chart showing the releasing process when the change in the actual turbine rotation speed is stagnated by the clamping pressure correction control. 6 is a time chart showing a release process when the actual turbine speed is increased by the clamping pressure correction control. In the time charts of FIGS. 5 and 6, time transitions of the rotational speed (rpm) and the hydraulic pressure (MPa) are shown, respectively, as in FIG. As the rotational speed, an engine rotational speed Ne, a target turbine rotational speed NTTGT, and an actual turbine rotational speed NT are shown. As the hydraulic pressure, the indicated clamping pressure Pd of the secondary sheave 12a is shown. The process shown in the flowchart of FIG. 4 is performed by the ECU 8 at predetermined intervals during, for example, the clamping pressure correction control. Hereinafter, according to the flowchart of FIG. 4, the canceling process of the clamping pressure correction control will be described with reference to FIGS.

  In step S201, it is determined whether or not the clutch engagement control upon return from the deceleration S & S control is being performed. If clutch engagement control is being performed (Yes in S201), the process proceeds to step S202, and if not (No in S201), this control flow is terminated. In the time charts of FIGS. 5 and 6, the clutch engagement control is performed from the beginning of this time chart.

  In step S202, it is determined whether or not the first clamping pressure correction control is being performed. If the first clamping pressure correction control is being performed (Yes in S202), the process proceeds to step S203, and if not (No in S202), this control flow ends. In the time charts of FIGS. 5 and 6, the first clamping pressure correction control is performed after time t6, the correction amount ΔP1 is added to the command clamping pressure Pd, and when the timing is after time t6, the process proceeds to step S203.

  In step S203, it is determined whether the second clamping pressure correction control is being performed. If the second clamping pressure correction control is being performed (Yes in S203), the process proceeds to step S204, and if not (No in S203), this control flow ends. In the time charts of FIGS. 5 and 6, the second clamping pressure correction control is performed after time t7, the correction amount ΔP2 is added to the command clamping pressure Pd + ΔP1, and the process proceeds to step S204 in the case of time t7 or later.

  In step S204, it is determined whether or not the average value of changes in the actual turbine speed NT for a plurality of routines is within a predetermined range. In other words, the amount of change in the actual turbine speed NT is calculated for each of a plurality of predetermined time intervals, and it is determined whether or not the average value of the plurality of changes falls within a predetermined range. When the average value of changes in the actual turbine speed NT for a plurality of routines is within the predetermined range (Yes in S204), it is determined that the fluctuation of the actual turbine speed NT is stagnant by the clamping pressure correction control. The process proceeds to step S206. On the other hand, when the average value of the actual turbine speed NT change for a plurality of routines is not within the predetermined range (No in S204), the process proceeds to step S205. In the time chart of FIG. 5, it is determined that the change in the actual turbine speed NT is within a predetermined range between the times t7 and t8, and the actual turbine speed NT is stagnant. In this case, the process proceeds to step S206. . On the other hand, in the time chart of FIG. 6, it is determined that the actual turbine speed NT change is not within the predetermined range between time t7 and t8, and in this case, the process proceeds to step S205.

  In step S205, it is determined whether or not the average value of the actual turbine speed NT change for a plurality of routines is increasing. In other words, it is determined whether or not the average value of the amount of change in the actual turbine speed NT in the plurality of time intervals calculated in step S204 is equal to or greater than a predetermined value. When the average value of changes in the actual turbine speed NT for a plurality of routines is increasing (Yes in S205), the actual turbine speed NT is increasing toward the target turbine speed NTTGT by the clamping pressure correction control. And the process proceeds to step S207. On the other hand, if the average value of changes in the actual turbine speed NT for a plurality of routines has not increased (No in S205), it is determined that the actual turbine speed NT is still decreasing, and the clamping pressure correction control is performed. To continue this control flow. In the time chart of FIG. 6, it is determined that the actual turbine rotational speed NT is increasing between times t7 and t8. In this case, the process proceeds to step S207.

  In step S206, as a result of the determination in step S204, the second clamping pressure correction control is included in the clamping pressure correction control when it is determined by the clamping pressure correction control that the fluctuation in the actual turbine speed NT is stagnant. Only end. When the fluctuation of the actual turbine speed NT is stagnated by the clamping pressure correction control, there is a possibility that the actual turbine speed NT will fall again due to the target turbine speed NTGT which decreases thereafter. The first clamping pressure correction control according to the inertia torque difference calculated based on the actual turbine speed NT is continued. On the other hand, if you continue to apply the clamping pressure equivalent to the maximum inertia torque, it means that excessive clamping pressure correction is being carried out, and there is a concern about deterioration of transmission efficiency due to belt durability deterioration and oil pump loss. The second clamping pressure correction control is terminated. When the process of step S206 is completed, this control flow ends. In the time chart of FIG. 5, it is determined that the actual turbine speed NT is stagnant, and only the second clamping pressure correction control is completed at time t8. Thereby, after time t8, the command clamping pressure Pd is reduced by the correction amount ΔP2.

  In step S207, as a result of the determination in step S205, it is determined that the actual turbine rotational speed NT is increasing by the clamping pressure correction control, and all the first and second clamping pressure correction controls are ended. This is because the inertia torque is not input when the actual turbine rotational speed NT increases toward the target turbine rotational speed NTTGT by the clamping pressure correction control. When the process of step S207 is completed, this control flow ends. In the time chart of FIG. 6, it is determined that the actual turbine speed NT is increasing, and all the clamping pressure correction control is completed at time t8. Thereby, after time t8, the indicated clamping pressure Pd is reduced by the correction amount ΔP1 + ΔP2.

  Note that when the clamping pressure correction control is terminated in steps S206 and S207, the decrease amount of the command clamping pressure Pd may be multiplied and gradually lowered.

  Next, effects of the drive control device 1 for the vehicle 100 according to the present embodiment will be described.

  The drive control device 1 according to the present embodiment includes an engine 2, a belt-type continuously variable transmission 5 that shifts power of the engine 2 and transmits the power to the drive wheels 7, and power transmission between the engine 2 and the transmission 5. And an ECU 8 for controlling the operation of the engine 2, the clutch 4 and the transmission 5. The ECU 8 performs the deceleration S & S control for releasing the clutch 4 and stopping the engine 2 while the vehicle 100 is traveling, thereby interrupting the power transmission between the engine 2 and the drive wheels 7 and causing the vehicle 100 to travel inertially. Can be implemented. The ECU 8 is an actual turbine that is an actual measurement value of the rotational speed of the input-side engagement member 4a on the engine 2 side of the clutch 4 when performing clutch engagement control for engaging the clutch 4 when returning from the deceleration S & S control. When the rotational speed NT is lower than the predetermined value α with respect to the target turbine rotational speed NTTGT, which is the target value of the rotational speed, in other words, the actual turbine rotational speed NT can cause the transmission 5 to cause belt slip. When the torque in the situation where the torque is transmitted from the clutch 4 to the transmission 5 is lower than the target turbine speed NTTGT, the inertia torque of the clutch 4 calculated from the target turbine speed NTTGT and the actual turbine speed The correction amount ΔP1 based on the difference from the inertia 4 of the clutch 4 calculated from the number NT is the command value of the clamping pressure Pd of the transmission 5. The first clamping pressure correction control added to the command clamping pressure Pd is performed.

  While the clutch engagement control is being performed, if the actual turbine speed NT is much lower than the target turbine speed NTGT below the predetermined value α, more torque than expected is input from the clutch 4 to the transmission 5. The torque input to the transmission 5 may exceed the torque capacity of the transmission 5 and belt slippage may occur in the transmission 5. In contrast, in the present embodiment, with the above configuration, when the actual turbine speed NT is lower than the predetermined value α with respect to the target turbine speed NTGTGT, the correction amount ΔP1 is added to the command clamping pressure Pd to the transmission 5. Therefore, it is possible to increase the pinching pressure generated in the transmission 5 and increase the torque capacity of the transmission 5. As a result, in the present embodiment, the occurrence of belt slip of the transmission 5 can be suppressed during the clutch engagement control.

  Since the belt slip of the transmission 5 can be suppressed, it is possible to suppress the deterioration of the torque transmission rate of the transmission 5. Further, when the condition that the actual turbine speed NT is significantly lower than the target turbine speed NTTGT is less than the predetermined value α, the instruction clamping pressure to the transmission 5 is increased, so that the clamping pressure of the transmission 5 is normal. Can be prevented from increasing unnecessarily, and adverse effects on the durability of the belt 13 of the transmission 5 can be suppressed. Furthermore, since the opportunity to increase the pinching pressure of the transmission 5 can be limited, the loss of the oil pump due to the generation of high pressure can be reduced, and the fuel efficiency can be improved.

  Further, in the drive control apparatus 1 of the present embodiment, the ECU 8 determines that the correction amount ΔP2 based on the maximum inertia torque of the clutch 4 is the command clamping pressure Pd when the descending gradient of the actual turbine speed NT becomes steep above a predetermined gradient. The second clamping pressure correction control added to is performed.

  When the descending gradient of the actual turbine speed NT is greater than or equal to a predetermined value, the inertia torque change becomes faster, and therefore the belt slip may not be suppressed by the first clamping pressure correction control. In contrast, in this case, the correction amount ΔP2 that can be derived in advance in this case based on the maximum inertia torque of the clutch 4 is added to the command clamping pressure Pd. The torque capacity can be increased quickly, and belt slippage of the transmission 5 can be suitably suppressed.

  Further, in the drive control device 1 of the present embodiment, the ECU 8 performs the second clamping pressure when the change in the actual turbine speed NT is stagnant during the first clamping pressure correction control and the second clamping pressure correction control. Only correction control is terminated. When the actual turbine speed NT increases toward the target turbine speed NTTGT, both the first clamping pressure correction control and the second clamping pressure correction control are terminated.

  With this configuration, the clamping pressure correction control can be released at an early stage depending on the situation, so that the opportunity to increase the clamping pressure of the transmission 5 can be further limited, and therefore the oil pump loss and the belt durability of the transmission 5 can be affected. Can be reduced.

  As mentioned above, although embodiment of this invention was described, the said embodiment was shown as an example and is not intending limiting the range of invention. The above-described embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. The above-described embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof, as long as they are included in the scope and gist of the invention.

  In the above-described embodiment, the inertial traveling in which the clutch 4 is released and the engine 2 is stopped while the vehicle 100 is traveling so that the power transmission between the engine 2 and the drive wheels 7 is interrupted to cause the vehicle 100 to travel by inertia. As an example of coasting control that performs the vehicle, the deceleration S & S control that is mainly performed while the vehicle is decelerating is mentioned. May be.

  In the above embodiment, the configuration in which the clutch 4 is disposed between the torque converter 3 and the transmission 5 on the power transmission path is illustrated. However, the clutch 4 is a power between the engine 2 and the drive wheels 7. If transmission can be connected / disconnected, it may be arranged at another position on the power transmission path. For example, it may be arranged between the transmission 5 and the drive wheel 7 or between the engine 2 and the torque converter 3.

DESCRIPTION OF SYMBOLS 1 Drive control apparatus 2 Engine 4 Clutch 5 Transmission 8 ECU (control means)
100 Vehicle NT Actual turbine speed (actual value)
NTTGT Target turbine speed (target value)
Pd indicated clamping pressure (command value)
ΔP1 Correction amount of first clamping pressure correction control ΔP2 Correction amount of second clamping pressure correction control

Claims (5)

Engine,
A belt-type continuously variable transmission that shifts the power of the engine and transmits it to drive wheels;
A clutch for connecting and disconnecting power transmission between the engine and the drive wheel;
Control means for controlling the operation of the engine, the clutch and the continuously variable transmission;
With
The control means includes
Performing coasting control to disengage the clutch and stop the engine during traveling of the vehicle, cut off power transmission between the engine and the drive wheels, and cause the vehicle to travel inertially;
When performing the engagement control for engaging the clutch from the coasting control, the measured value of the rotation speed of the engagement member on the engine side of the clutch is less than a predetermined value with respect to the target value of the rotation speed. When the value is smaller, the correction amount based on the difference between the inertia torque of the clutch calculated from the target value and the inertia torque of the clutch calculated from the actual measurement value becomes the command value of the clamping pressure of the continuously variable transmission. A drive control device for a vehicle, which performs a first clamping pressure correction control to be added.   The control means adds a correction amount based on the maximum value of the inertia torque to the command value of the pinching pressure of the continuously variable transmission when the descending slope of the actual measurement value becomes steep above a predetermined slope. The vehicle drive control device according to claim 1, wherein the second clamping pressure correction control is performed.   The control means ends the second clamping pressure correction control when a change in the measured value is stagnant during the first clamping pressure correction control and the second clamping pressure correction control. The vehicle drive control device according to claim 2.   When the measured value rises toward the target value during the first clamping pressure correction control and the second clamping pressure correction control, the control means performs the first clamping pressure correction control and the second clamping pressure correction control. The vehicle drive control device according to claim 2 or 3, wherein the 2 pinching pressure correction control is terminated. In the first narrow pressure correction control,
The measured value of the rotational speed of the engagement member on the engine side of the clutch is the rotational speed in a situation where torque that can cause belt slip in the continuously variable transmission is transmitted from the clutch to the continuously variable transmission. When the rotational speed is lower than the target value, the amount of correction based on the difference between the clutch inertia calculated from the target value and the clutch inertia calculated from the measured value is not calculated. The vehicle drive control device according to any one of claims 1 to 4, wherein the vehicle drive control device is added to a command value of the clamping pressure of the step transmission.

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