JP6565706B2 - Vehicle shift control device - Google Patents

Description

  The present invention relates to a vehicle shift control device capable of changing a gear ratio stepwise, and more particularly to a vehicle shift control device using a meshing engagement mechanism as an engagement mechanism for setting a predetermined gear position. It is about.

  Patent Document 1 describes an automatic transmission device including a planetary gear mechanism. In the automatic transmission, one rotating element in the planetary gear mechanism is fixed by engaging a meshing engagement mechanism, and the engine and another rotating element in the planetary gear mechanism are engaged by a friction engagement mechanism. By combining, the reverse gear is set. The meshing engagement mechanism is configured to be engaged only when the reverse gear is set, and each engagement mechanism is engaged or released by controlling the hydraulic pressure to be supplied. It is configured.

Japanese Patent Laid-Open No. 10-89421

  Since the meshing engagement mechanism configured as described in Patent Document 1 cannot control the transmission torque capacity, each meshing mechanism is used to prevent the meshing teeth from meshing unintentionally during release. The teeth are kept in a relatively distant position. Therefore, in order to engage the meshing engagement mechanism, the amount of movement of one meshing tooth increases. Therefore, due to factors such as deterioration over time and individual differences, the time from the start of supplying hydraulic pressure to engage the meshing engagement mechanism until the meshing engagement mechanism meshes may be slower than the intended time. There is sex.

  When the meshing engagement mechanism as described above is used as an engagement mechanism for setting a predetermined gear, and when shifting from another gear to a predetermined gear, two meshing engagement mechanisms are configured. Of the meshing teeth, it is preferable that the meshing teeth engage with each other at almost the same time as the rotational speed of one meshing tooth is changed to synchronize with the rotational speed of the other meshing tooth. Therefore, when the time from the start of supplying the hydraulic pressure for engaging the meshing engagement mechanism to the time when the meshing engagement mechanism meshes becomes slower than the intended time, the rotation speed of one meshing tooth is reduced. There is a possibility that the rotational speed exceeds the rotational speed synchronized with the rotational speed of the other meshing tooth, and in such a case, it may be difficult to engage the meshing engagement mechanism, or A shock may occur by engaging the meshing engagement mechanism. In addition, when the engine output torque is limited in order to prevent the rotational speed of one meshing tooth from exceeding the rotational speed synchronized with the rotational speed of the other meshing tooth as described above, After the shift stage is set, the engine output torque may be increased, and as a result, the acceleration response after the shift may be reduced.

  The present invention has been made paying attention to the technical problem described above, and engages each meshing tooth at an appropriate timing when setting a predetermined gear position by engaging a meshing engagement mechanism. An object of the present invention is to provide a shift control device for a vehicle that can perform this.

In order to achieve the above object, the present invention is directed to an engine, a stepped transmission that is connected to the output side of the engine and changes a gear ratio in a stepwise manner, and a predetermined gear stage in the transmission. A meshing engagement mechanism that is engaged to set the engagement, and an actuator configured to engage the meshing engagement mechanism when hydraulic pressure is supplied, and the meshing engagement is performed during a downshift. A gear shift control device for a vehicle that engages a combination mechanism includes a controller that controls the actuator and the engine, and the controller controls the input shaft speed of the transmission device during the downshift, the vehicle speed, and the gear shift after the gear shift. A calculation unit for obtaining a deviation from a target rotational speed obtained from a gear ratio at a stage, and the deviation obtained by the calculation part or the input shaft rotational speed Serial based on the target rotational speed duration also a high rotation speed than a first correction unit to advance the timing for supplying hydraulic pressure to the actuator at the time of next downshift, output of the engine during the next downshift torque, to allow greater than the output torque of the engine at the time of the downshift, that a second correcting unit to lower the limit of the output torque of the engine at the time of previous SL next downshifting It is a feature.

  According to this invention, the meshing engagement mechanism is based on the deviation between the input shaft rotational speed and the target rotational speed at the time of the previous downshift, or the duration for which the input shaft rotational speed is higher than the target rotational speed. The timing for supplying the hydraulic pressure to the actuator for engaging is increased. Therefore, at the next downshift, the meshing engagement mechanism can be engaged almost simultaneously with the increase of the input shaft rotational speed to the target rotational speed. As a result, even if the time from when the hydraulic pressure is started to be supplied to the actuator until the meshing engagement mechanism is engaged is different from the design value due to individual differences of the meshing engagement mechanism and deterioration over time. The meshing engagement mechanism can be easily engaged, and the occurrence of shock associated with the engagement of the meshing engagement mechanism can be suppressed. Further, since the meshing engagement mechanism can be engaged almost simultaneously with the increase of the input shaft rotational speed to the target rotational speed, the limit amount of the engine output torque can be reduced. It can suppress that the acceleration responsiveness after setting is reduced.

It is a flowchart for demonstrating an example of the control in the Example of this invention. It is a skeleton figure which shows an example of the transmission in the Example of this invention. It is an engagement table | surface which shows the engagement mechanism engaged when setting each gear stage. It is a time chart for demonstrating the continuation time when the turbine blowing amount (maximum value) at the time of a power-on downshift, the integrated value of turbine blowing amount, and the turbine rotation speed are more than target rotation speed. FIG. 6 is a time chart for explaining changes in turbine rotational speed, hydraulic pressure for engaging a second brake, and engine output torque limit when the control shown in FIG. 1 is executed. FIG.

  An example of a transmission 1 having a meshing engagement mechanism according to the present invention is schematically shown in FIG. The transmission 1 shown in FIG. 2 is a stepped transmission that changes the gear ratio stepwise, and changes the first forward speed to the eighth forward speed, the first reverse speed, and the second reverse speed. Can be set. The transmission 1 is connected to the engine 2 via a torque converter. Specifically, a conventionally known torque converter with a lock-up clutch is connected to the output shaft 3 of the engine 2, and the input shaft 4 of the transmission 1 is connected to the turbine constituting the torque converter. . The rotational speed of the input shaft 4 corresponds to the input shaft rotational speed in the embodiment of the present invention, and in the following description, the rotational speed of the input shaft 4 is referred to as “turbine rotational speed”.

  The above transmission includes a double pinion type planetary gear mechanism (hereinafter referred to as a first planetary gear mechanism) 5 and a Ravigneaux type planetary gear mechanism (hereinafter referred to as a second planetary gear mechanism) 6. . The first carrier 7 in the first planetary gear mechanism 5 is connected to the input shaft 4, and the first sun gear 8 in the first planetary gear mechanism 5 is connected to a fixed portion 9 such as a housing.

  A second planetary gear mechanism 6 is provided on the opposite side of the engine 2 across the first planetary gear mechanism 5. The second planetary gear mechanism 6 transmits torque input from the engine 2 or the first planetary gear mechanism 5 to a drive wheel (not shown). The second carrier 10 in the second planetary gear mechanism 6 It is connected to the input shaft 4 through a two-clutch C2 so that torque can be transmitted. The second sun gear 11 in the second planetary gear mechanism 6 is connected to the first ring gear 12 in the first planetary gear mechanism 5 via the third clutch C3 so as to be able to transmit torque, and via the fourth clutch C4. The first carrier 7 is connected to be able to transmit torque. Further, the third sun gear 13 in the second planetary gear mechanism 6 is connected to the first ring gear 12 via the first clutch C1 so as to transmit torque. And the 2nd ring gear 14 in the 2nd planetary gear mechanism 6 is connected with the driving wheel which is not illustrated so that torque transmission is possible.

  Further, a first brake B1 for stopping the rotation of the second sun gear 11 and a second brake B2 for stopping the rotation of the second carrier 10 are provided. The first brake B1 is a conventionally known frictional engagement mechanism, and is configured to control the transmission torque capacity. On the other hand, the second brake B2 corresponds to the meshing engagement mechanism in the present invention, and meshes the meshing teeth formed on the fixed portion 9 and the meshing teeth formed on the second carrier 10. Thus, the rotation of the second carrier 10 is stopped. The second brake B2 is configured such that by supplying hydraulic pressure to a hydraulic actuator (not shown), one of the meshing teeth moves toward the other meshing tooth so that each meshing tooth meshes, and the hydraulic pressure is reduced. Accordingly, the meshing teeth are configured to be separated from each other. Therefore, the time from when the hydraulic pressure is supplied to the hydraulic actuator until the meshing teeth mesh with each other is determined by the hydraulic pressure supplied to the hydraulic actuator, resistance such as sliding resistance when one meshing tooth moves toward the other meshing tooth It depends on the force and volume of the hydraulic actuator.

  In this embodiment, an electronic control unit for electrically controlling the control of engaging or releasing the clutches C1, C2, C3, and C4 and the brakes B1 and B2 and the fuel supply of the engine 2 ( ECU) 15 is provided. The ECU 15 corresponds to the controller in the present invention, and is configured mainly with a microcomputer. The ECU 15 receives data such as the vehicle speed and the accelerator opening, performs calculations using the input data and data stored in advance, and outputs the calculation result as a control command signal. It is configured.

  FIG. 3 shows an engagement table of the transmission 1 shown in FIG. Note that “◯” shown in FIG. 3 indicates an engaged state, and “−” indicates a released state. As shown in FIG. 3, the first forward speed is set by engaging the first clutch C1 and the second brake B2, and the second forward speed is determined by engaging the first clutch C1 and the first brake B1. Set by engaging. The downshift from the second forward speed to the first forward speed is performed by releasing the first brake B1 and engaging the second brake B2 with the first clutch C1 engaged. Is called. Such a downshift is performed when the amount of operation of the accelerator pedal by the driver exceeds a predetermined amount of operation and a large driving force is required, or in order to maintain the engine speed at a predetermined speed. This is executed when the vehicle speed drops below a predetermined vehicle speed.

  As described above, when the downshift (power-on downshift) is performed on the condition that the amount of operation of the accelerator pedal by the driver is equal to or greater than the predetermined amount of operation, the determination to execute the downshift is established. The hydraulic pressure for engaging the second brake B2 is supplied to the hydraulic actuator on the condition that a predetermined time elapses from or after the turbine rotational speed is equal to or higher than the predetermined rotational speed. In the power-on downshift, first, the transmission torque capacity of the first brake B1 is decreased to increase the turbine rotation speed, and the turbine rotation speed is a target rotation speed obtained from the speed ratio after the shift and the vehicle speed. This is because the second brake B2 is engaged almost simultaneously with the synchronization. Therefore, the predetermined time and the predetermined rotational speed are equal to the time required for the turbine rotational speed to increase to the target rotational speed and from the start of supplying hydraulic pressure to the second brake B2 until the second brake B2 starts to be engaged. And is determined based on the time.

  On the other hand, the second brake B2 has a time from supplying hydraulic pressure to the hydraulic actuator until the second brake B2 starts to be engaged is longer than the time determined by design due to individual differences and deterioration over time. May be slow. In such a case, the second brake B2 may start to be engaged when the turbine rotation speed blows up to the target rotation speed or higher. Since the turbine rotational speed depends on the output of the engine 2, if the output torque of the engine 2 is limited in order to suppress the occurrence of the above situation, the engine 2 is set after the first forward speed is set. It is necessary to further increase the output torque of the motor, and the acceleration responsiveness may be reduced.

  Therefore, when a power-on downshift is executed, learning of the timing to start engaging the second brake B2 when the next power-on downshift is executed is performed based on the amount of turbine blow-up at the time of the power-on downshift. -It is comprised so that it may correct | amend and the limiting amount of the output torque of the engine 2 may be reduced.

  An example of the control is shown in FIG. The control shown in FIG. 1 is executed by the ECU 15. In the control shown in FIG. 1, it is first determined whether or not a downshift is being performed (step S1). In step S1, whether or not there is a change from the second forward speed to the first forward speed, or shift control from the second forward speed to the first forward speed is executed by other control. It can be determined by whether or not it exists.

  If a negative determination is made in step S1 because the downshift has not been executed, this routine is temporarily terminated. On the other hand, if a positive determination is made in step S1 by executing the downshift, the target rotational speed, which is the turbine rotational speed when the first forward speed is set, and the actual rotational speed are set. A deviation (turbine blowing amount) from the turbine rotational speed is measured (step S2). The turbine rotational speed can be obtained based on a signal from a sensor that detects the rotational speed of the input shaft 4, and the target rotational speed is obtained from the speed ratio at the first forward speed and the current vehicle speed. Can do. Step S2 corresponds to the “calculation unit” in the embodiment of the present invention.

  Next, it is determined whether or not it is necessary to learn the timing to start engaging the second brake B2 (step S3). This step S3 can be determined based on whether or not the turbine blow amount measured in step S2 is larger than a predetermined threshold value in consideration of a shock or the like when the second brake B2 is engaged. In addition, when learning the timing which starts engaging 2nd brake B2 at the time of the last power-on downshift, the learning value which changed the timing will be updated by this step S3.

  If it is not necessary to learn the timing to start engaging the second brake B2, and the determination is negative in step S3, this routine is temporarily terminated. On the other hand, it is necessary to learn the timing to start engaging the second brake B2. If the determination in step S3 is affirmative, the second brake B2 is engaged at the next power-on downshift. The timing to start the correction is corrected (step S4). More specifically, the timing to start supplying hydraulic pressure to the hydraulic actuator is advanced. The time corrected in this step S4 is a value such as the maximum value of the turbine blow amount ΔN shown in FIG. 4, the integrated value ΣΔN of the turbine blow amount, or the duration time L1 when the turbine speed is equal to or higher than the target speed. A map that defines the time to be corrected as a variable is stored in advance in the ECU 15 based on experiments, simulations, etc., and the map and the actually detected turbine blow amount, its integrated value, or the turbine speed is the target rotation. It can be determined on the basis of the duration that is more than the number. This step S4 corresponds to the “first correction unit” in the present invention. Note that the timing at which the second brake B2 starts to be engaged may be determined by the turbine rotational speed, or may be determined by the elapsed time from the determination of shifting start.

  Next, the limit amount of the output torque of the engine 2 is relaxed (step S5), and this routine is once ended. This output torque limit amount is a limit amount stored in advance in the ECU 15 in order to prevent the turbine speed from excessively increasing from the target speed. Therefore, by correcting the timing at which the second brake B2 is started to be engaged in step S4, it is possible to suppress the turbine speed from becoming higher than the target speed. Therefore, in step S5, the restriction amount is relaxed. To do. Therefore, as the learning of the timing at which the second brake B2 starts to be engaged (timing to start supplying hydraulic pressure to the hydraulic actuator) progresses, it is possible to further suppress the turbine rotational speed from becoming higher than the target rotational speed. Therefore, the limit amount of the output torque of the engine 2 is gradually reduced. The amount to be relaxed may be a predetermined value or may be a variable determined according to the turbine blow amount ΔN or the like. This step S5 corresponds to the “second correction unit” in the embodiment of the present invention.

  FIG. 5 is a time chart for explaining changes in the turbine rotational speed, changes in the hydraulic pressure for engaging the second brake B2, and changes in the output torque limit amount of the engine 2 when the control shown in FIG. 1 is executed. It shows. A downshift (power-on downshift) from the second forward speed to the first forward speed is determined at time t1 in FIG. Accordingly, the transmission torque capacity of the first brake B1 is reduced, and the torque is output from the engine 2 in accordance with the accelerator operation amount by the driver, so that the turbine rotation speed starts to increase.

  Then, when the turbine rotation speed increases to a predetermined rotation speed, or when a predetermined time elapses after the determination of the downshift from the second forward speed to the first forward speed is established (time t2), The hydraulic pressure for engaging the second brake B2 is output. In this case, the hydraulic pressure command pressure is changed stepwise up to a predetermined pressure as shown by a broken line, but the actual hydraulic pressure gradually increases as shown by a solid line.

  Next, the hydraulic pressure of the second brake B2 increases to the command pressure almost at the same time when the turbine speed increases to the target speed (the speed calculated from the speed ratio of the first forward speed and the vehicle speed) (t3). Time). Since the second brake B2 at this time has not yet been engaged, the turbine speed has exceeded the target speed, and then the second brake B2 is engaged, The target rotational speed matches (time t4). At this time, based on the maximum value of the turbine blow amount ΔN, the integrated value ΣΔN of the turbine blow amount, or the elapsed time L1 from the time point t3 to the time point t4, the second brake B2 is started to be engaged at the next downshift. The timing is learned (corrected), and the limit amount of the output torque of the engine 2 is reduced. Therefore, at the time point t4, the limit amount of the output torque of the engine 2 is decreasing.

  FIG. 5 shows a state in which the upshift determination is established at the same time as the downshift is completed. At the time of upshifting from the first forward speed to the second forward speed, the output torque of the engine 2 is reduced, the second brake B2 is released, and then the first brake B1 is gradually engaged and executed. It is configured. Therefore, in the example shown in the figure, the hydraulic pressure for engaging the second brake B2 is lowered after the upshift determination is established. Note that when the hydraulic pressure for engaging the second brake B2 is decreased, the command pressure is changed stepwise as in the case of engaging the second brake B2, and the actual hydraulic pressure gradually decreases. ing.

  When the determination of downshift is again established after reaching the second forward speed (time t5), the turbine rotational speed starts increasing as described above. On the other hand, by learning the timing at which the second brake B2 starts to be engaged during the previous downshift, when the elapsed time ta from time t5 is shorter than the elapsed time tb from time t1 to time t2, Two brakes B2 are engaged.

  As described above, by learning the timing at which the second brake B2 starts to be engaged according to the turbine blow amount at the time of the previous downshift, the turbine speed has increased to the target speed at the next downshift. The second brake B2 can be engaged almost simultaneously. Therefore, the time from the start of supplying the hydraulic pressure for engaging the second brake B2 to the engagement of the second brake B2 is different from the design value due to individual differences of the second brake B2 and deterioration over time. Even if it exists, the 2nd brake B2 can be engaged easily, and generation | occurrence | production of the shock accompanying the 2nd brake B2 engaging can be suppressed. Further, since the second brake B2 can be engaged almost simultaneously with the increase in the turbine speed to the target speed, the limit amount of the output torque of the engine 2 can be reduced, and as a result, the forward first speed stage. It can suppress that the acceleration responsiveness after setting is reduced.

  DESCRIPTION OF SYMBOLS 1 ... Transmission device, 2 ... Engine, 3 ... Output shaft, 4 ... Input shaft, 15 ... Electronic control unit (ECU), B1, B2 ... Brake, C1, C2, C3 ... Clutch.

Claims (1)

An engine, a stepped transmission that is connected to the output side of the engine and changes a gear ratio stepwise, and a meshing engagement that is engaged with the transmission to set a predetermined gear In a vehicle transmission control device comprising a mechanism and an actuator configured to engage the meshing engagement mechanism when hydraulic pressure is supplied, and to engage the meshing engagement mechanism during a downshift,
A controller for controlling the actuator and the engine;
The controller is
A calculation unit for obtaining a deviation between an input shaft rotation speed of the transmission during the downshift and a target rotation speed obtained from a vehicle speed and a gear ratio at a gear position after the shift;
First to advance the timing of supplying hydraulic pressure to the actuator at the time of the next downshift based on the deviation obtained by the calculation unit or the duration time during which the input shaft rotational speed is higher than the target rotational speed A correction unit ;
The output torque of the engine during the next downshift, as can larger than the output torque of the engine at the time of the downshift, reduces the limit of the output torque of the engine at the time of previous SL next downshifting A vehicle shift control device comprising: a second correction unit.

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