JP2014052004A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve shift controllability even in a region where torque on a rotating member on a side of an input shaft of an automatic transmission is relatively small at starting an inertia phase during upshift of the automatic transmission.SOLUTION: A lower limit value is provided for one of upshift engagement side clutch torque and upshift disengagement side clutch torque, thus allowing use of the upshift engagement side clutch torque after starting an inertia phase in a relatively large region. Namely, the lower limit value is provided for the upshift engagement side clutch toque, thus allowing the inevitable use of the upshift engagement side clutch torque in the relatively large region. Otherwise, the lower limit value is provided for the upshift disengagement side clutch torque, thus producing such effects as if transmission input torque Ti is increased, to allow the use of the upshift engagement side clutch torque in the relatively large region.

Description

  The present invention relates to a vehicle control device that executes a shift of an automatic transmission by switching between engagement and disengagement of an engagement device, and particularly relates to control during upshifting.

  A so-called engagement device (engagement-side engagement device) and disengagement-side engagement device (release-side engagement device) are replaced (that is, by switching between engagement device and engagement device). 2. Description of the Related Art A vehicle control apparatus including an automatic transmission that performs clutch-to-clutch shift is well known. For example, this is the hydraulic control device for an automatic transmission described in Patent Document 1. This Patent Document 1 prevents engine blow-up by generating a weak tie-up state by holding the disengagement side engagement device with a minute torque capacity until the start of the inertia phase is detected during upshifting. However, a technique for suppressing a shock at the start of the inertia phase is disclosed.

JP 2007-271035 A

  By the way, after the inertia phase is started, as shown in Patent Document 1, the engagement oil pressure of the disengagement side engagement device (release side oil pressure) is gradually decreased (sweep down) while the engagement side engagement device is engaged. The change in input rotation of the automatic transmission during the inertia phase is controlled by the combined hydraulic pressure (engagement side hydraulic pressure). At this time, in a region where the input torque of the automatic transmission (the output torque of the driving force source agrees) is relatively small, the torque capacity (engagement side torque capacity) of the engagement side engagement device is also compared with this input torque. Controlled in a small area. On the other hand, in general, in an engagement device having a return spring, a torque capacity effective for an engagement hydraulic pressure exceeding an engagement hydraulic pressure corresponding to a force against the return spring load (engagement hydraulic pressure × piston pressure receiving area). Is generated. Then, in the control in the region where the torque capacity is small, the degree of change in the torque capacity itself (for example, the change in torque capacity / the torque capacity before the change) accompanying the change in the engagement hydraulic pressure is larger than in the control in the large region. . For this reason, in a region where the torque capacity is relatively small, the controllability of the torque capacity may be deteriorated. From another viewpoint, in a region where the torque capacity is relatively small, there is a possibility that the torque capacity is likely to be affected by variations in the actual value with respect to the command value of the engagement hydraulic pressure and variations in the return spring load. There is a possibility that the degree of change will increase. In addition, as shown in Patent Document 1, when the release side hydraulic pressure is withdrawn from the weak tie-up state during the inertia phase, the gear shift speed (for example, the input rotation change gradient) is changed to a target value. In order to proceed, it is necessary to lower the engagement side torque capacity, which may further deteriorate the controllability. The above-mentioned problem is not known, and even when the input torque of the automatic transmission is in a relatively small region, the use of the engagement side torque capacity after the start of the inertia phase in a relatively large region. Not yet proposed.

  The present invention has been made against the background of the above circumstances, and the object thereof is on the rotating member on the input shaft side of the automatic transmission at the start of the inertia phase during the upshift of the automatic transmission. An object of the present invention is to provide a vehicle control device capable of improving the controllability of gear shifting even when the torque is in a relatively small region.

  The gist of the first invention for achieving the above object is that (a) a shift is executed by switching between engagement and disengagement of a drive force source and an engagement device having a return spring, and the drive A vehicle control device including an automatic transmission that transmits power of a power source to a drive wheel side, and (b) an engagement device on an engagement side from the start of an inertia phase at the time of upshift of the automatic transmission The lower limit value is provided in either one of the torque capacity and the torque capacity of the engagement device on the disengagement side.

  In this way, by providing a lower limit value for the torque capacity of the engagement device, the torque capacity of the engagement device on the engagement side from the start of the inertia phase can be used in a relatively large region. That is, by providing a lower limit value for the torque capacity of the engagement device on the engagement side, the torque capacity of the engagement device on the engagement side can inevitably be used in a relatively large region. Alternatively, by providing a lower limit value for the torque capacity of the engagement device on the disengagement side, it is possible to obtain an effect as if the torque on the rotating member on the input shaft side of the automatic transmission is increased, and The torque capacity of the combined device can be used in a relatively large region. Accordingly, the engagement hydraulic pressure of the engagement device on the engagement side can be used in a sufficiently large region with respect to the engagement hydraulic pressure corresponding to the force against the return spring load. The degree of change in the torque capacity itself is made relatively small, or the degree of change in the torque capacity with respect to variations in hydraulic pressure, return spring load, etc. is made relatively small, thereby improving the controllability of the torque capacity. Therefore, even when the torque on the rotating member on the input shaft side of the automatic transmission at the start of the inertia phase at the time of upshifting of the automatic transmission is in a relatively small region, the controllability of the shift can be improved.

  Here, according to a second aspect, in the vehicle control device according to the first aspect, a torque on the rotating member on the input shaft side of the automatic transmission at the start of the inertia phase is smaller than a predetermined input torque. In this case, the control for providing the lower limit value is executed. In this way, when the torque on the rotary member on the input shaft side of the automatic transmission at the start of the inertia phase is equal to or greater than the predetermined input torque, the torque capacity of the engagement device on the engagement side can be further increased. Therefore, a decrease in durability of the engagement device on the engagement side is suppressed.

  According to a third aspect of the present invention, in the vehicle control apparatus according to the first or second aspect of the invention, the torque on the rotating member on the output shaft side of the automatic transmission is driven by providing the lower limit value. When the required amount cannot be satisfied, the output torque of the driving force source is increased. In this way, the lowering of the driving force due to the weak tie-up state is appropriately compensated by providing a lower limit value for the torque capacity of the engagement device.

  According to a fourth aspect of the present invention, in the vehicle control device according to any one of the first to third aspects, the control for providing the lower limit value is performed when the engagement device is engaged. This is to be executed when the learning in the rapid filling control is finished. In this way, the torque capacity of the engagement device on the engagement side is hardly affected by variations in hydraulic pressure, variations in return spring load, etc., so that the controllability of torque capacity can be further improved.

  According to a fifth aspect of the present invention, in the vehicle control device according to the second aspect, when a lower limit value is provided for the torque capacity of the engagement-side engagement device, the engagement-side engagement device is provided. The shift of the automatic transmission is advanced by controlling the torque capacity of the disengagement side engagement device while controlling the torque capacity to the lower limit value. In the case of providing a lower limit value, the torque capacity of the engaging device on the release side is set as a lower limit value with a torque capacity amount that generates a torque amount that the torque on the rotating member on the input shaft side is insufficient with respect to the predetermined input torque. While controlling, the shift of the automatic transmission is advanced by controlling the torque capacity of the engagement device on the engagement side. In this way, the torque capacity of the engagement device on the engagement side from the start of the inertia phase can be used in a relatively large region, and appropriate when setting a lower limit for the torque capacity of the engagement device. The speed change can be advanced.

  According to a sixth invention, in the vehicle control device according to the second or fifth invention, the torque on the rotating member on the input shaft side of the automatic transmission at the start of the inertia phase is the predetermined value. The case where the torque is smaller than the input torque is a case where a target value of the torque capacity of the engagement device on the engagement side at the start of the inertia phase is smaller than a predetermined torque capacity. In this way, the target value of the torque capacity of the engagement device on the engagement side at the start of the inertia phase, which is set according to the torque on the rotating member on the input shaft side of the automatic transmission, is less than the predetermined torque capacity. If it is smaller, control for providing a lower limit value for the torque capacity of the engagement device is appropriately executed.

It is a figure explaining the schematic structure of the power transmission path | route in the vehicle to which this invention is applied, and is a figure explaining the principal part of the control system provided in the vehicle. It is the elements on larger scale which show an example of an engagement apparatus. It is a functional block diagram explaining the principal part of the control function of an electronic controller. It is the conceptual diagram which represented the shifting progress state at the time of upshift of an automatic transmission on a collinear diagram. The main part of the control operation of the electronic control unit, that is, the control operation for improving the controllability of the shift even when the transmission input torque at the start of the inertia phase during the upshift of the automatic transmission is in a relatively small region will be described. It is a flowchart and is an example in the case of carrying out a lower limit guard process at the time of upshift engagement side clutch torque. The main part of the control operation of the electronic control unit, that is, the control operation for improving the controllability of the shift even when the transmission input torque at the start of the inertia phase during the upshift of the automatic transmission is in a relatively small region will be described. It is a flowchart and is an example in the case of carrying out a lower limit guard process for the release side clutch torque at the time of upshift. The main part of the control operation of the electronic control unit, that is, the control operation for improving the controllability of the shift even when the transmission input torque at the start of the inertia phase during the upshift of the automatic transmission is in a relatively small region will be described. It is a flowchart and is an example in the case of compensating for a decrease in driving force.

  In the present invention, preferably, in the automatic transmission, a plurality of shift stages (gear stages) having different speed ratios (gear ratios) are alternatively selected by switching between engagement and release of a predetermined engagement device. It is a stepped automatic transmission formed in For example, the stepped automatic transmission is constituted by a known planetary gear automatic transmission. As an engagement device in this planetary gear type automatic transmission, a hydraulic engagement device such as a multi-plate type, single plate type clutch or brake engaged with a hydraulic actuator, or a band brake is widely used. In this case, the vehicle includes a hydraulic control circuit that supplies hydraulic pressure to hydraulic actuators of a plurality of engagement devices, for example. The hydraulic control circuit includes, for example, a linear solenoid valve and an ON-OFF solenoid valve, and supplies the output hydraulic pressure of the solenoid valve directly or indirectly to the hydraulic actuator of the engagement device via a shift control valve or the like. . Note that “supplying hydraulic pressure” means “applying hydraulic pressure” or “supplying hydraulic oil controlled to a certain hydraulic pressure”. The engaging device may be another engaging device such as an electromagnetic type, a magnetic type, or a mechanical type.

  Preferably, an engine such as a gasoline engine or a diesel engine is used as the driving force source. Alternatively, as the driving force source, for example, a prime mover such as an electric motor is used alone or in combination with the engine.

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

  FIG. 1 is a diagram illustrating a schematic configuration of a power transmission path from an engine 12 to a drive wheel 26 provided in a vehicle 10 to which the present invention is applied, and illustrates a main part of a control system provided in the vehicle 10. It is a figure explaining. In FIG. 1, power generated by an engine 12 as a driving force source is input to an input shaft 16 of an automatic transmission 18 via a torque converter 14, and a differential gear device ( It is transmitted to the left and right drive wheels 26 via a differential gear) 22 and a pair of axles (drive shafts) 24 in order.

  The automatic transmission 18 includes one or a plurality of planetary gear devices and a plurality of engagement devices (engagement elements) in a transmission case as a non-rotating member attached to the vehicle body. This is a known planetary gear type automatic transmission that can be alternatively established. For example, the automatic transmission 18 performs a so-called clutch-to-clutch shift in which a shift is executed by re-holding any of a plurality of engagement devices (that is, by switching between engagement and release of the engagement devices). It is a transmission. That is, the automatic transmission 18 shifts the rotation of the input shaft 16 and outputs it from the output shaft 20, and transmits the power from the engine 12 to the drive wheel 26 side. The input shaft 16 is also a turbine shaft that is rotationally driven by the turbine wheel of the torque converter 14. The engagement device is controlled to be engaged and disengaged by the hydraulic control circuit 28, and the torque capacity, that is, the engagement force is changed by adjusting the pressure of the solenoid valve or the like in the hydraulic control circuit 28. It is a hydraulic friction engagement device such as a clutch or a brake that selectively connects the members on both sides that are inserted.

  FIG. 2 is a partially enlarged view showing a clutch C which is an example of a hydraulic friction engagement device. In FIG. 2, the clutch C includes a clutch drum 30, a clutch hub 32, a separate plate 34, a friction plate 36, a piston 38, a return spring 40, a spring receiving plate 42, and the like. The separate plate 34 has a plurality of substantially annular plate-like (disc-like) outer peripheral edges that are spline-fitted to the inner peripheral surface of the cylindrical portion of the clutch drum 30. The friction plate 36 is interposed between a plurality of separate plates 34, and a plurality of substantially annular plate-shaped (disc-shaped) inner peripheral edges are splined to the outer peripheral surface of the clutch hub 32. The piston 38 is provided with a pressing portion extending in the direction of the separate plate 34 and the friction plate 36 on the outer peripheral edge. The return spring 40 is interposed between the piston 38 and the spring receiving plate 42 and urges the piston 38 so as to contact the bottom plate portion of the clutch drum 30. In the clutch C configured as described above, when the hydraulic oil is supplied into the oil chamber 46 through the oil passage 44, the piston 38 is separated from the separation plate 34 and the friction plate 36 by the hydraulic pressure (that is, the engagement hydraulic pressure) of the hydraulic oil. The pressing portion of the piston 38 presses the separate plate 34 and the friction plate 36. Since the snap ring 48 is fixed to the cylinder portion of the clutch drum 30, the plurality of separate plates 34 and the friction plate 36 are engaged. That is, the clutch C is engaged.

  Here, the torque capacity of the engagement device (hereinafter referred to as clutch torque) is determined by, for example, the friction coefficient of the friction material of the engagement device and the engagement hydraulic pressure that presses the friction plate. In an engagement device having a return spring 40 such as the clutch C, a clutch torque effective at an engagement hydraulic pressure exceeding an engagement hydraulic pressure corresponding to a force against the return spring load (engagement hydraulic pressure × piston pressure receiving area). Is generated.

  Returning to FIG. 1, as an example of the gear stage in the automatic transmission 18, for example, a low vehicle speed side gear stage (low gear stage, for example, the second gear stage) is established by engagement of the clutch C1 and the brake B1, and the clutch C1 And a clutch C2 are engaged to establish a high vehicle speed side gear (high gear, for example, third gear). Therefore, at the time of shifting between the low gear stage and the high gear stage, the brake B1 and the clutch C2 are replaced. In this embodiment, among the engagement devices that are re-gripped at the time of shifting, the engagement device (for example, the brake B1) involved in the establishment of the low gear stage side is referred to as the low gear stage engagement apparatus, and the high gear stage side is established. The engaging device (for example, clutch C2) involved is referred to as a high gear stage engaging device. The low gear stage engagement device becomes a disengagement side engagement device when upshifting from a low gear step to a high gear step, and becomes an engagement side engagement device when downshifting from a high gear step to a low gear step. On the other hand, the high gear stage engaging device becomes an engaging-side engaging device during the upshift, and becomes a releasing-side engaging device during the downshift.

  The vehicle 10 is provided with an electronic control unit 70 including a control unit related to, for example, shift control of the automatic transmission 18. The electronic control unit 70 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 70 performs output control of the engine 12, shift control of the automatic transmission 18, etc., and is divided into engine control, hydraulic control (shift control), etc. as necessary. Configured. The electronic control unit 70 also has various signals (for example, the rotational speed of the engine 12) detected by various sensors (for example, the rotational speed sensors 50, 52, 54, the accelerator opening sensor 56, the throttle valve opening sensor 58, etc.). The engine rotational speed ωe representing the rotational speed of the input shaft 16, the turbine rotational speed ωt representing the rotational speed of the input shaft 16, that is, the transmission input rotational speed ωi, the transmission output rotational speed ωo representing the rotational speed of the output shaft 20 corresponding to the vehicle speed V, Accelerator opening degree Acc, throttle valve opening degree θth, and the like representing the operation amount of the driver with respect to driving force (driving torque is also agreed) are supplied. Further, from the electronic control unit 70, for example, an engine output control command signal Se for output control of the engine 12, a hydraulic command signal Sp for operating a hydraulic control circuit 28 for controlling the hydraulic actuator of the automatic transmission 18, and the like. , Respectively.

  FIG. 3 is a functional block diagram illustrating a main part of the control function by the electronic control unit 70. In FIG. 3, an engine output control means, that is, an engine output control unit 72 opens and closes an electronic throttle valve by a throttle actuator for throttle control so that, for example, a requested engine torque Te (hereinafter, requested engine torque Tedem) is obtained. In addition to the control, the fuel injection amount by the fuel injection device is controlled for the fuel injection amount control, and the engine output control command signal Se for controlling the ignition device such as an igniter is output for the ignition timing control. The engine output control unit 72 is based on the actual accelerator opening degree Acc and the vehicle speed V from a not-shown relationship (driving force map) stored in advance between the vehicle speed V and the required driving force Fdem using, for example, the accelerator opening degree Acc as a parameter. A required driving force Fdem as a required driving amount is calculated. The engine output control unit 72, for example, the effective tire radius of the drive wheel 26, the gear ratio at the current gear stage of the automatic transmission 18, the final reduction ratio in the power transmission path on the drive wheel 26 side of the output shaft 20, and Based on the torque ratio t of the torque converter 14, a required engine torque Tedem that provides the required driving force Fdem is calculated. The torque ratio t of the torque converter 14 is stored in advance, for example, each of a speed ratio (= turbine rotational speed ωt / pump rotational speed ωp (engine rotational speed ωe)), torque ratio t, efficiency, and capacity coefficient. It is calculated based on the actual speed ratio e from a known relationship (operation characteristic diagram of the torque converter 14).

  The shift control means, that is, the shift control unit 74 executes shift control of the automatic transmission 18. Specifically, the shift control unit 74 is a vehicle indicated by the actual vehicle speed V and the accelerator opening Acc from a known relationship (shift map, shift diagram) stored in advance with the vehicle speed V and the accelerator opening Acc as variables. Shift determination is performed based on the state. When the shift control unit 74 determines that the shift of the automatic transmission 18 should be executed, the shift control unit 74 executes the automatic shift control of the automatic transmission 18 so that the gear stage to be shifted is obtained. For example, the shift control unit 74 outputs to the hydraulic control circuit 28 a hydraulic command signal Sp that engages and / or releases an engagement device involved in the shift of the automatic transmission 18 so that the determined gear stage is achieved. To do. As the hydraulic pressure command signal Sp, for example, a hydraulic pressure command value for obtaining a torque capacity of the low gear stage engaging device (hereinafter referred to as a low gear stage side clutch torque) and a torque capacity of the high gear stage engaging apparatus (hereinafter referred to as the high gear stage side). This is a hydraulic pressure command value for obtaining a clutch torque).

  Here, the shift control during the upshift of the automatic transmission 18 will be described in detail. When the automatic transmission 18 is upshifted, the shift control unit 74 prevents the engine 12 from blowing up and suppresses a shock at the start of the inertia phase, for example, based on a change in the rotation of the transmission input rotational speed ωi. Until the start of phase is detected, the low gear stage engagement device (ie, the release side engagement device during upshifting) and the high gear stage engagement device (ie, the engagement side engagement device during upshifting) A weak tie-up state is generated by controlling the side clutch torque (that is, the release side clutch torque at the time of upshift). Then, after the start of the inertia phase, the shift control unit 74 controls the high gear stage side clutch torque (that is, the upshift engagement clutch torque) so as to realize the shift target value.

  The shift target value can express, for example, target values for shift time and driving force. As an example of an element that can express the shift time, the input shaft 16 as a time derivative of the turbine rotational speed ωt (that is, the transmission input rotational speed ωi), that is, a time change rate, that is, a speed change amount of the rotating member on the input shaft 16 side. Angular acceleration (hereinafter, input shaft angular acceleration dωt / dt). An example of an element that can express the driving force is torque on the output shaft 20 (hereinafter referred to as transmission output torque To) as torque on the rotating member on the output shaft 20 side. The shift control unit 74 has a predetermined mode of changing the input shaft angular acceleration dωt / dt so that, for example, the change in the turbine rotational speed ωt during the inertia phase becomes a predetermined change that balances the suppression of the shift shock and the shift time. The target value of the input shaft angular acceleration dωt / dt during the inertia phase is calculated from the relationship (input shaft angular acceleration change map). Further, the shift control unit 74 is based on the required driving force Fdem calculated by the engine output control unit 72 from a relationship (transmission output torque change map) in which a mode for changing the transmission output torque To is determined in advance, for example. A target value of the transmission output torque To is calculated. Then, the shift control unit 74 sets the shift target value, the release-side clutch torque at the time of upshift, the engagement-side clutch torque at the time of upshift, and the torque on the input shaft 16 as the torque on the rotating member on the input shaft 16 side. From the gear train motion equation of the automatic transmission 18 in which the relationship with the transmission input torque Ti (hereinafter referred to as “transmission input torque Ti”) is formulated, for example, the required value of the engagement side clutch torque at the time of upshift that realizes the shift target value after the start of the inertia phase. And a hydraulic pressure command signal Sp for obtaining the required value is output to the hydraulic pressure control circuit 28. The required value of the release side clutch torque at the time of upshift after the start of the inertia phase is calculated, for example, as a value that gradually decreases at a predetermined gradient from the start of the inertia phase. The transmission input torque Ti is the same as the engine torque Te (= Ti / t) in consideration of the torque ratio t of the torque converter 14, and the required value is calculated based on the accelerator opening Acc or the like. Based on the driving force Fdem, a required value equivalent to that at the normal time (non-shifting time) is calculated.

  By the way, when the transmission input torque Ti is in a relatively small region, if it is assumed that the release side clutch torque at the time of upshift is gradually reduced after the start of the inertia phase, the upshift can proceed appropriately (that is, In order to reduce the transmission input rotational speed ωi at an appropriate speed), it is necessary to control the engagement side clutch torque at the time of upshift in a relatively small region. As described above, since the engagement device involved in the shift of the automatic transmission 18 in this embodiment has the return spring 40, the clutch in the region where the clutch torque is relatively small is compared with the control in the large region. Torque controllability may be degraded. Also, it is easily affected by variations in hydraulic pressure and variations in return spring load. Therefore, when the transmission input torque Ti is in a relatively small region, there is a possibility that the shift controllability of the automatic transmission 18 is deteriorated as compared with the case where it is in a large region.

  In the present embodiment, even when the transmission input torque Ti is in a relatively small region, the automatic transmission 18 is used by using the engagement clutch torque at the time of upshift after the start of the inertia phase in a relatively large region. The control for improving the shift controllability is executed. Hereinafter, the control will be described in detail.

  FIG. 4 is a conceptual diagram showing, on a nomographic chart, the shift progress state during the upshift of the automatic transmission 18. In FIG. 4, the a-axis corresponds to the rotational speed of the rotating member connected to the engaging device, the b-axis corresponds to the transmission output rotational speed ωo, and the c-axis corresponds to the transmission input rotational speed ωi. The solid line Llow indicates the state when the low gear stage is formed, the broken line Lup indicates the state when the high gear stage is formed, and the arrow UP indicates the traveling direction of the upshift. As shown by the arrow A, the engagement-side clutch torque at the time of upshift is a moment in a direction to shift the state of the solid line Llow to the state of the broken line Lup (that is, a moment in a direction to reduce the rotation of the c-axis transmission input rotational speed ωi). ). Therefore, when the moment at which the transmission input torque Ti as shown by the arrow B is generated (that is, the moment in the direction of increasing the rotation of the c-axis transmission input rotational speed ωi) is small, the clutch on the engagement side at the time of upshifting Torque is controlled in a small area. On the other hand, as shown by the arrow C, the up-shift release side clutch torque generates a moment in a direction that does not shift the state of the solid line Llow to the state of the broken line Lup. That is, the release side clutch torque at the time of upshift generates a moment in the same direction as the transmission input torque Ti (positive value) is generated, as indicated by an arrow C '. Therefore, the increase / decrease in the release side clutch torque during the upshift corresponds to the increase / decrease in the transmission input torque Ti.

  In the present embodiment, in consideration of the above, the inertia phase at the time of upshift of the automatic transmission 18 is used in order to use the engagement side clutch torque at the time of upshift after the start of the inertia phase in a relatively large region. It has been found that a lower limit value may be provided for either one of the engagement clutch torque at the time of upshift from the start time and the release side clutch torque at the time of upshift. For example, in this embodiment, when the transmission input torque Ti at the start of the inertia phase (the engine torque Te agrees) is smaller than the predetermined input torque, the control for providing the lower limit value is executed. The predetermined input torque is, for example, a lower limit value of the transmission input torque Ti for the target value of the engagement-side clutch torque at the time of upshift at the start of the inertia phase to be equal to or greater than a predetermined clutch torque (that is, a predetermined torque capacity). Is a predetermined value. The target value of the engagement clutch torque at the time of upshift at the start of the inertia phase is the engagement at the time of upshift required to start the inertia phase (that is, to start the rotation change of the transmission input rotational speed ωi). This is the side clutch torque (for example, the required value of the engagement side clutch torque at the time of upshift after the start of the inertia phase calculated from the gear train motion equation of the automatic transmission 18). The predetermined clutch torque is a value determined in advance as a lower limit value for suppressing the deterioration of the controllability of the clutch torque by the target value of the engagement side clutch torque at the time of upshift at the start of the inertia phase. Therefore, the case where the transmission input torque Ti at the start of the inertia phase is smaller than the predetermined input torque corresponds to the case where the target value of the engagement side clutch torque at the time of upshift at the start of the inertia phase is smaller than the predetermined clutch torque. To do.

  More specifically, returning to FIG. 3, the shift control unit 74 determines whether or not the upshift of the automatic transmission 18 is being executed, for example, the shift determined from the shift map is the upshift and the shift control thereof. Judgment is made based on whether or not. Further, the shift control unit 74 determines whether or not the upshift being executed has ended.

  When the shift control unit 74 determines that an upshift of the automatic transmission 18 is being executed, the torque determination unit, that is, the torque determination unit 76, determines that the transmission input torque Ti at the start of the inertia phase in the upshift is It is determined whether or not the torque is smaller than a predetermined input torque. From another viewpoint, the torque determination unit 76 determines whether or not the target value of the up-shift engagement side clutch torque at the start of the inertia phase is smaller than the predetermined clutch torque.

  When the torque determination unit 76 determines that the transmission input torque Ti at the start of the inertia phase in the upshift of the automatic transmission 18 is greater than the predetermined input torque (that is, at the start of the inertia phase). (When it is determined that the target value of the engagement side clutch torque at the time of upshift is larger than the predetermined clutch torque), as described above, the engagement at the time of upshift is performed so as to realize the shift target value after the start of the inertia phase. Shift control based on the side clutch torque is executed. For example, the shift control unit 74 is a hydraulic pressure command signal for obtaining a required value of the up-shift engagement side clutch torque that realizes the shift target value after the start of the inertia phase calculated from the gear train motion equation of the automatic transmission 18. Sp is output to the hydraulic control circuit 28.

  The lower limit guard process control means, that is, the lower limit guard process control unit 78, determines that the torque determination unit 76 determines that the transmission input torque Ti at the start of the inertia phase in the upshift of the automatic transmission 18 is equal to or less than the predetermined input torque. (That is, when it is determined that the target value of the engagement clutch torque at the time of upshift at the start of the inertia phase is equal to or less than the predetermined clutch torque), the engagement side clutch torque at the time of the upshift after the start of the inertia phase Control for setting the lower limit value is executed. For example, the lower limit guard process control unit 78 performs a lower limit guard process that maintains (controls) the engagement clutch torque at the time of upshift after the start of the inertia phase at a predetermined clutch torque as a lower limit value. If the engagement clutch torque at the time of upshifting is maintained at the lower limit value, it is substantially difficult to execute the shift control based on the engagement side clutch torque at the time of upshifting. Therefore, the shift control unit 74 realizes the shift target value after the start of the inertia phase when the lower limit guard process control unit 78 performs the lower limit guard processing on the up-shift engagement clutch torque after the start of the inertia phase. As described above, the shift of the automatic transmission 18 is advanced by executing the shift control mainly of the release side clutch torque during the upshift. For example, the shift control unit 74 sets the engagement clutch torque at the upshift to the lower limit value instead of calculating the required value of the engagement clutch torque at the upshift from the gear train motion equation of the automatic transmission 18. Then, a required value of the up-shift release side clutch torque for realizing the shift target value after the start of the inertia phase is calculated from the gear train motion equation of the automatic transmission 18, and a hydraulic pressure command signal for obtaining the required value Sp is output to the hydraulic control circuit 28.

  Alternatively, when the torque determination unit 76 determines that the transmission input torque Ti at the start of the inertia phase in the upshift of the automatic transmission 18 is equal to or less than the predetermined input torque, the lower limit guard processing control unit 78 performs the inertia phase. Instead of the control for setting the lower limit value for the engagement clutch torque at the time of upshift after the start, control for setting the lower limit value for the release side clutch torque at the time of the upshift after the start of the inertia phase may be executed. For example, as described above, the release side clutch torque at the time of upshift generates a moment in the same direction as the transmission input torque Ti is generated (that is, the increase of the release side clutch torque at the time of upshift is the transmission input torque). Since this corresponds to increasing Ti), the lower limit guard processing control unit 78 sets the clutch torque that causes the transmission input torque Ti to be insufficient with respect to the predetermined input torque as the lower limit, and the release side during upshifting A lower limit guard process for controlling the clutch torque is executed. That is, the transmission input torque Ti is generated so that a moment equivalent to that generated when the transmission input torque Ti is the predetermined input torque (a moment in the direction of increasing the rotation of the transmission input rotational speed ωi) can be obtained. The lower limit guard process is performed on the sum of the moment to be generated and the moment generated by the release side clutch torque at the time of upshift. That is, the lower limit guard torque is applied to the release side clutch torque at the time of upshift so as to generate a moment that can be obtained when the transmission input torque Ti is a predetermined input torque. The shift control unit 74 is increased so as to realize the shift target value after the start of the inertia phase when the lower limit guard process control unit 78 performs the lower limit guard torque on the release side clutch torque after the start of the inertia phase. The shift of the automatic transmission 18 is advanced by executing shift control mainly based on the engagement side clutch torque at the time of shift. For example, the shift control unit 74 sets the release-side clutch torque at the time of upshifting to a lower limit value, and then performs an upshift time relationship that realizes a shift target value after the start of the inertia phase from the gear train motion equation of the automatic transmission 18. A required value of the clutch clutch torque is calculated, and a hydraulic pressure command signal Sp for obtaining the required value is output to the hydraulic pressure control circuit 28.

  FIGS. 5 and 6 respectively show the control operation of the electronic control unit 70, that is, the shift control even when the transmission input torque Ti at the start of the inertia phase during the upshift of the automatic transmission 18 is in a relatively small region. 5 is a flowchart for explaining a control operation for improving the performance, and is repeatedly executed with an extremely short cycle time of, for example, about several milliseconds to several tens of milliseconds. FIG. 5 shows an example of the case where the lower limit guard process is performed on the engagement side clutch torque during the upshift, and FIG. 6 shows an example of the case where the lower limit guard process is performed on the release side clutch torque during the upshift.

  In FIG. 5, first, in step (hereinafter, step is omitted) SA10 corresponding to the shift control unit 74, it is determined whether, for example, an upshift of the automatic transmission 18 is being executed. If the determination of SA10 is negative, this routine is terminated. If the determination is positive, in SA20 corresponding to the torque determination unit 76, for example, at the time of upshift at the start of the inertia phase (to start the inertia phase) It is determined whether or not the target value of the engagement side clutch torque is equal to or less than a predetermined clutch torque. When the determination at SA20 is affirmative, at SA30 corresponding to the lower limit guard process control unit 78, for example, the engagement side clutch torque at the time of upshift after the start of the inertia phase is subjected to the lower limit guard process. Next, in SA40 corresponding to the shift control unit 74, for example, shift control based on the upshift release side clutch torque is executed so as to realize a shift target value after the start of the inertia phase, for example. On the other hand, when the determination of SA20 is negative, in SA50 corresponding to the shift control unit 74, for example, the shift control based on the engagement side clutch torque at the time of upshift so as to realize the shift target value after the start of the inertia phase, for example. Is executed. Subsequent to SA40 or SA50, at SA60 corresponding to the shift control unit 74, for example, it is determined whether the upshift being executed has ended. If the determination at SA60 is negative, the routine returns to SA20, but if the determination is affirmative, this routine is terminated. As described above, in the control operation of SA30 and SA40, during the inertia phase, the shift is not advanced by controlling the engagement clutch torque at the time of upshift, but the engagement side clutch torque at the time of the upshift is dared to be a constant torque. The shift is advanced by controlling the release side clutch torque at the time of upshifting while maintaining the above as a weak tie-up.

  In FIG. 6, first, at step SB10 corresponding to the shift control unit 74, for example, it is determined whether or not an upshift of the automatic transmission 18 is being executed. If the determination at SB10 is negative, this routine is terminated. If the determination is affirmative, at SB20 corresponding to the torque determination unit 76, for example, the transmission input torque Ti at the start of the inertia phase is equal to or less than the predetermined input torque. It is determined whether or not. If the determination of SB20 is affirmative, in SB30 corresponding to the lower limit guard processing control unit 78, for example, the sum of the moment generated by the transmission input torque Ti and the moment generated by the release side clutch torque at the time of upshift is the lower limit guard. It is processed. Next, in SB 40 corresponding to the shift control unit 74, for example, shift control based on the engagement side clutch torque is performed so as to realize a shift target value after the start of the inertia phase. On the other hand, when the determination of SB20 is negative, in SB50 corresponding to the shift control unit 74, for example, the shift control based on the engagement side clutch torque at the time of upshift so as to realize the shift target value after the start of the inertia phase, for example. Is executed. Subsequent to the SB 40 or the SB 50, in the SB 60 corresponding to the shift control unit 74, for example, it is determined whether or not the upshift being executed has ended. If the determination at SB60 is negative, the routine returns to SB20, but if the determination is affirmative, this routine is terminated. Thus, in the control operation of the SB30, during the inertia phase, by deliberately giving the clutch torque to the release side clutch torque at the time of upshift and making it weak tie-up, than when not making it weak tie-up, Engagement-side clutch torque (engagement-side hydraulic pressure) is increased during upshifting.

  As described above, according to the present embodiment, by setting a lower limit value for either one of the clutch torque at the time of upshift and the clutch torque at the time of release of the upshift, it is possible to increase after the start of the inertia phase. The engagement side clutch torque at the time of shift can be used in a relatively large region. In other words, by providing a lower limit value for the up-shift engagement-side clutch torque, the up-shift engagement-side clutch torque can inevitably be used in a relatively large region. Alternatively, by providing a lower limit value for the release side clutch torque at the time of upshift, the effect can be obtained as if the transmission input torque Ti has been increased, and the engagement side clutch torque at the time of upshift can be increased in a relatively large region. Can be used. Accordingly, since the engagement side hydraulic pressure can be used in a sufficiently large region with respect to the engagement hydraulic pressure corresponding to the force against the return spring load, the degree of change in the clutch torque itself accompanying the change in the engagement side hydraulic pressure is achieved. Can be made relatively small, or the degree of change in clutch torque with respect to variations in hydraulic pressure, return spring load, etc. can be made relatively small, and controllability of the clutch torque can be improved. Therefore, even when the transmission input torque Ti at the start of the inertia phase during the upshift of the automatic transmission 18 is in a relatively small region, the controllability of the shift can be improved.

  Further, according to this embodiment, when the transmission input torque Ti at the start of the inertia phase is equal to or less than the predetermined input torque, the control for setting the lower limit value for the clutch torque is executed, so the transmission input at the start of the inertia phase When the torque Ti is larger than the predetermined input torque, the engagement clutch torque at the time of upshift is not further increased, and a decrease in durability of the engagement device at the time of upshift is suppressed.

  Further, according to the present embodiment, when a lower limit value is set for the engagement clutch torque at the time of upshift, the release side clutch torque at the time of upshift is controlled while the engagement side clutch torque at the time of upshift is controlled to the lower limit value. By controlling, the upshift of the automatic transmission 18 is advanced, and when a lower limit value is provided for the release side clutch torque at the time of upshift, the amount of torque that the transmission input torque Ti is insufficient with respect to the predetermined input torque is reduced. The upshift of the automatic transmission 18 is advanced by controlling the engagement side clutch torque at the time of upshifting while controlling the release side clutch torque at the time of upshifting with the generated torque capacity as a lower limit value. The clutch torque on the engagement side can be used in a relatively large area when upshifting from The upshift can be appropriately advanced when the lower limit value is set.

  Further, according to this embodiment, when the transmission input torque Ti at the start of the inertia phase is smaller than the predetermined input torque, the target value of the engagement side clutch torque at the time of upshifting at the start of the inertia phase is the predetermined torque capacity. Therefore, if the target value of the engagement side clutch torque at the time of upshift at the start of the inertia phase, which is set in accordance with the transmission input torque Ti, is smaller than the predetermined torque capacity, the clutch torque Control for setting the lower limit value is appropriately executed.

  Next, another embodiment of the present invention will be described. In the following description, parts common to the embodiments are denoted by the same reference numerals and description thereof is omitted.

  In the first embodiment, the engagement side clutch torque (engagement side hydraulic pressure) at the time of upshift is increased by executing the control for setting the lower limit value for the clutch torque during the inertia phase to make a weak tie-up. . Therefore, in the control for setting the lower limit value for the clutch torque, there is a possibility that the actual driving force falls with respect to the required driving force Fdem and it becomes easy to feel a shock. Therefore, the electronic control unit 70 of the present embodiment increases the engine torque Te when the transmission output torque To cannot satisfy the required driving force Fdem by providing a lower limit value for the clutch torque.

  Specifically, the torque determination unit 76 performs the control with respect to the target value of the transmission output torque To corresponding to the required driving force Fdem when the lower limit guard processing control unit 78 is executing control to provide a lower limit value for the clutch torque. It is determined whether or not the actual value decrease is equal to or greater than a predetermined decrease torque. The predetermined reduction torque is, for example, a predetermined determination threshold value for determining that the torque reduction is such that it is easy to feel a shock that occurs when the actual value decreases with respect to the target value of the transmission output torque To. It is.

  The engine output control unit 72 determines that the actual value of the transmission output torque To is determined when the torque determination unit 76 determines that the decrease in the actual value with respect to the target value of the transmission output torque To is equal to or greater than the predetermined decrease torque. The engine torque Te is increased so as not to be lower than the target value by a predetermined decrease torque or more. The actual value of the transmission output torque To is calculated based on the actual engine torque Te or calculated from the gear train motion equation of the automatic transmission 18.

  FIG. 7 shows that the control operation of the electronic control unit 70 is improved, that is, the shift controllability is improved even when the transmission input torque Ti at the start of the inertia phase during the upshift of the automatic transmission 18 is in a relatively small region. For example, the control operation is repeatedly executed with a very short cycle time of about several milliseconds to several tens of milliseconds. FIG. 7 shows an embodiment in the case where control for compensating for a decrease in driving force is added in the control operation of the flowchart shown in FIG. 6, and the same control operation is executed at the same step number as in FIG. In the following description of FIG. 7, the control operation part newly added in the control operation of the flowchart shown in FIG. 6 will be mainly described.

  In FIG. 7, after SB40, in SB45 corresponding to the torque determination unit 76, the transmission output torque To corresponding to the required driving force Fdem is generated by the tie-up caused by execution of the control for providing the lower limit value for the clutch torque. It is determined whether or not the actual value decrease relative to the target value is greater than or equal to a predetermined decrease torque. If the determination at SB45 is affirmative, at SB46 corresponding to the engine output control unit 72, the engine torque Te is increased so that the actual value of the transmission output torque To does not become lower than the target value by a predetermined decrease torque or more ( That is, the transmission input torque Ti is increased). When the determination at SB45 is negative, or after SB46 or SB50, at SB60 corresponding to the shift control unit 74, for example, it is determined whether the upshift being executed has ended.

  As described above, according to this embodiment, in addition to the same effects as those of the first embodiment, the transmission output torque To satisfies the required driving force Fdem by providing a lower limit value for the clutch torque. When the engine torque Te cannot be achieved, the engine torque Te is increased. Therefore, the lowering of the driving force due to the weak tie-up state is appropriately compensated by providing a lower limit value for the clutch torque.

  In the above-described embodiment, the clutch torque controllability may be deteriorated in a region where the clutch torque is relatively small, and the clutch torque is easily affected by variations in hydraulic pressure and return spring load. By executing the control for setting the lower limit value in the torque, the shift controllability of the automatic transmission 18 is improved. Here, it is considered that the controllability of the clutch torque can be further improved by executing the control for setting the lower limit value for the clutch torque in a manner that eliminates variations in hydraulic pressure, return spring load, and the like as much as possible. In order to eliminate the variation as much as possible, it is preferable to perform learning control of the engagement hydraulic pressure used when engaging the engagement device, in particular, the engagement hydraulic pressure for closing the pack clearance associated with the return spring 40. is there. Therefore, in the present embodiment, the control for setting the lower limit value for the clutch torque is executed when the learning in the quick filling control at the time of engaging the engagement device is completed.

  Specifically, the shift control unit 74 rapidly fills the hydraulic oil so that the pack clearance of the engagement-side engagement device is quickly reduced when the hydraulic pressure supply is started when the engagement-side engagement device is engaged. Shift hydraulic pressure learning control means that learns the hydraulic pressure command value in the rapid filling control that outputs a temporarily high hydraulic pressure command value and executes a known learning control using the learned value as the next hydraulic pressure command value A hydraulic learning control unit is functionally provided.

  The lower limit guard processing control unit 78 uses the shift control unit 74 when the torque determination unit 76 determines that the transmission input torque Ti at the start of the inertia phase in the upshift of the automatic transmission 18 is equal to or less than the predetermined input torque. When the learning of the hydraulic pressure command value in the quick filling control has been completed, control for setting a lower limit value for the clutch torque is executed. When the learning of the hydraulic pressure command value is completed, for example, when the learning control of the hydraulic pressure command value by the transmission control unit 74 is performed at least once, the hydraulic pressure in the learning control of the hydraulic pressure command value by the transmission control unit 74 is This is the case when the change in the learning value of the command value from the previous time becomes smaller than a predetermined change (that is, it can be determined that the learning value has converged to a certain value).

  As described above, according to the present embodiment, in addition to obtaining the same effect as that of the above-described embodiment, the control for setting the lower limit value for the clutch torque is performed rapidly when the engagement side engagement device is engaged. Since it is executed when learning in the filling control is completed, the clutch torque at the time of upshifting is hardly affected by variations in hydraulic pressure, variations in return spring load, etc., and clutch torque controllability is further improved. .

  As mentioned above, although the Example of this invention was described in detail based on drawing, it is applied also in another aspect.

  For example, in the above-described embodiments, each embodiment is implemented independently. However, the above embodiments are not necessarily implemented independently, and may be implemented in combination as appropriate.

  In the above-described embodiment, when the transmission input torque Ti at the start of the inertia phase at the time of upshifting of the automatic transmission 18 is smaller than the predetermined input torque, the engagement side clutch at the time of the upshift from the start of the inertia phase. Although the control for setting the lower limit value to either one of the torque and the release side clutch torque at the time of upshift is executed, it is not necessarily limited to the case where the transmission input torque Ti at the start of the inertia phase is smaller than the predetermined input torque. That is, the SA20 step in the flowchart of FIG. 5 and the SB20 step in the flowcharts of FIGS. Even if it does in this way, this invention is materialized and the same effect is acquired.

  Further, in the above-described second embodiment (particularly, FIG. 7), the engine torque Te is increased when the actual value decrease with respect to the target value of the transmission output torque To is equal to or greater than the predetermined decrease torque. Absent. For example, when the actual value is lower than the target value of the transmission output torque To, the engine torque Te may be increased so that the actual value of the transmission output torque To does not become lower than the target value. In addition, here, the control for compensating for the decrease in driving force by increasing the engine torque (transmission input torque increasing) is applied to the control (for example, FIG. 6) for setting the lower limit value on the release side clutch torque at the time of upshifting. Further, the present invention may be applied to control (for example, FIG. 5) that provides a lower limit value for the engagement-side clutch torque during upshifting.

  In the above-described embodiment, the output shaft 20 is exemplified as the rotating member on the output shaft 20 side. However, the present invention is not limited to this, and the rotating member on the output shaft 20 side is a power transmission path from the output shaft 20 to the drive wheels 26. Any rotating member may be used. Although the input shaft 16 is illustrated as the rotating member on the input shaft 16 side, the present invention is not limited to this, and the rotating member on the input shaft 16 may be a rotating member in the power transmission path from the engine 12 to the input shaft 16.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 12: Engine (drive power source)
18: Automatic transmission 26: Drive wheel 40: Return spring 70: Electronic control device (control device)
B1: Brake (engagement device)
C1, C2: Clutch (engagement device)

Claims (6)

A vehicle control apparatus comprising: a driving force source; and an automatic transmission that performs a shift by switching between engagement and disengagement of an engagement device having a return spring and transmits the power of the driving force source to the drive wheel side Because
A vehicle having a lower limit value provided for either the torque capacity of the engagement device on the engagement side or the torque capacity of the engagement device on the release side from the start of the inertia phase at the time of upshifting of the automatic transmission. Control device.   The control for providing the lower limit value is executed when a torque on a rotating member on an input shaft side of the automatic transmission at the start of the inertia phase is smaller than a predetermined input torque. Vehicle control device.   The output torque of the driving force source is increased when the torque on the rotating member on the output shaft side of the automatic transmission cannot satisfy the required driving amount by providing the lower limit value. The vehicle control device according to 1 or 2.   4. The control according to claim 1, wherein the control for providing the lower limit value is executed when learning in the quick filling control at the time of engaging the engagement device is finished. 5. Vehicle control device. When providing a lower limit value for the torque capacity of the engagement device on the engagement side, the torque capacity of the engagement device on the release side is controlled while controlling the torque capacity of the engagement device on the engagement side to the lower limit value. The shift of the automatic transmission is advanced by controlling,
When a lower limit value is provided for the torque capacity of the engagement device on the release side, a torque capacity component that generates a torque component that the torque on the rotating member on the input shaft side is insufficient with respect to the predetermined input torque is set as the lower limit value. The shift of the automatic transmission is advanced by controlling the torque capacity of the engagement device on the engagement side while controlling the torque capacity of the engagement device on the release side. The vehicle control device according to 2.   When the torque on the rotating member on the input shaft side of the automatic transmission at the start of the inertia phase is smaller than the predetermined input torque, the torque capacity of the engagement device on the engagement side at the start of the inertia phase 6. The vehicle control device according to claim 2, wherein the target value is smaller than a predetermined torque capacity.

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