JP5496056B2 - Control device for dual clutch automatic transmission - Google Patents

Description

  The present invention relates to a control device for a dual clutch type automatic transmission, and more particularly to a control device for preventing engine blow-up during upshifting.

  For example, in an automatic transmission in which a planetary gear mechanism is combined with a widely used torque converter, automatic operation is performed by switching the operation state of the planetary gear mechanism by controlling engagement of a multi-plate clutch. When this type of automatic transmission shifts in the upshift direction as the vehicle accelerates, the engine rotation speed is increasing due to the accelerator operation, so there is a slight shift in clutch engagement timing or a decrease in clutch operating hydraulic pressure. When this occurs, a shock may occur due to engagement of the clutch with the engine running.

As a countermeasure against such a problem, for example, in the technology described in Patent Document 1, when the vehicle is shifted up due to vehicle acceleration, the engine speed is determined based on the clutch input / output shaft speed ratio, and the engine speed increases. If it is determined that the clutch is operating, measures are taken to correct the clutch hydraulic pressure.
Incidentally, apart from the torque converter type automatic transmission, a so-called dual clutch type automatic transmission has recently been put into practical use. This dual clutch type automatic transmission is configured by connecting a first gear mechanism composed of a plurality of odd gears and a second gear mechanism composed of a plurality of even gears to the engine side via first and second clutches, respectively. Has been.

For example, when the driving force of the engine is transmitted to the drive wheel side via any odd gear of the first gear mechanism by connecting the first clutch, any even gear is determined based on the acceleration / deceleration status of the vehicle. Is predicted as the next shift speed, and preselection is performed to switch the second gear mechanism, which has stopped power transmission due to the disengagement of the second clutch, to the next shift speed.
When it is determined whether or not the shift to the next selected gear position (upshift or downshift) has been made when the shift timing is reached, the clutch is switched to reverse the connecting / disconnecting state of both clutches and the next gear position is changed. Shifting to has been completed.

The shift determination is performed according to the following procedure based on a predetermined shift map for obtaining the target shift speed from the accelerator opening and the vehicle speed.
For example, FIG. 8 is a time chart showing a shift state by the control device of the prior art when it is determined that the upshift is made during vehicle acceleration. After the pre-selection to the next gear stage is completed, when the engine speed Ne that is increasing as the vehicle accelerates reaches the shift-up line corresponding to the shift timing to the next gear stage on the shift map, the pre-selected next A determination is made as to whether to shift up to the gear position (point e in FIG. 8). Then, after setting the next shift speed as the target shift speed, the clutch is switched as described above to complete the upshift to the next shift speed.

Japanese Patent Publication No. 7-37217

By the way, the torque characteristics of the engine tend to cause a torque drop near the upper limit of the use rotation range (the full rotation range from idle rotation to the permissible rotation). For example, in a diesel engine, the upper limit of the use rotation range is prevented to prevent overspeed. The torque is drastically reduced by reducing the fuel injection amount in the vicinity (hereinafter, a region where such a phenomenon occurs is referred to as a torque limit region). The above-described shift-up line is set to a considerably high rotation side in the engine use rotation range in order to effectively use the rotation range with good torque for vehicle acceleration in the process of increasing the engine rotation speed Ne. Therefore, there is no large margin between the lower limit of the torque limit area.
For this reason, for example, if the accelerator is fully opened under the condition that the vehicle is lightly loaded and the accelerator is fully opened, the engine speed Ne will be increased due to the engine blow-up before the clutch switching at the time of shifting up is completed (point g in FIG. 8). May enter the torque limit region (point f in FIG. 8). In this case, there arises a problem that a shock with a feeling of deceleration is generated due to the torque reduction, and a shock with a feeling of acceleration is generated due to an increase in torque after the clutch switching is completed.

The shock resulting from such torque limitation is far more conspicuous than the shock due to engine swelling that is assumed by the technology of Patent Document 1, and is a factor that greatly impairs the ride comfort of the vehicle. It is clear that the countermeasure of the technique of Patent Document 1 that corrects the operating hydraulic pressure cannot be solved. Needless to say, if the shift-up line is changed to the low-rotation side as a countermeasure, it is not possible to effectively use the rotation range where the torque is good due to the early shift-up, and the driver's intended acceleration feeling cannot be obtained.
The present invention has been made to solve such problems, and the object of the present invention is to achieve a good acceleration feeling by always performing a shift-up at an appropriate timing, and then to blow the engine. It is an object of the present invention to provide a control apparatus for a dual clutch automatic transmission that can prevent a rushing to a torque limit region caused by a rise and thereby prevent a shock caused by the rush.

  In order to achieve the above object, a first aspect of the present invention is to connect a pair of gear mechanisms composed of a plurality of shift speeds to the engine side via a clutch, and connect one clutch to the corresponding one gear mechanism. Pre-selection is performed to switch the other gear mechanism to the next shift stage in advance during power transmission via the shift stage, and when the engine speed crosses a preset shift line after preselect, In a control device for a dual clutch automatic transmission that completes switching to the next gear position by reversing the engagement / disengagement state of both clutches by the gear shift execution means based on the gear shift approval, the accelerator opening is preset. When the vehicle is accelerated to a value equal to or greater than the accelerator opening threshold, it is possible to shift up to the next shift stage based on the shift line after the high gear shift stage is preselected as the next shift stage. A rotation increase prediction means for sequentially predicting a value after a preset prediction time of the engine rotation speed that is increasing with vehicle acceleration, and an engine rotation speed after the prediction time predicted by the rotation increase prediction means. Until the preset upper limit rotation threshold is not reached, the shift execution means is prohibited from shifting up to the next shift stage, and when the engine speed after the predicted time reaches the upper limit rotation threshold, the shift execution means On the other hand, it is provided with a shift-up prohibition / permission means for permitting a shift-up to the next shift stage.

  According to a second aspect of the present invention, in the first aspect, at least the time required for clutch switching at the time of shifting up to the next shift stage by the shift execution means is set as the predicted time, and at least when the engine is increased in rotation as the upper limit rotation threshold value. A value on the lower rotation side than the lower limit of the torque limit region where the torque starts to decrease is set.

As described above, according to the control apparatus for a dual clutch automatic transmission of the first aspect of the present invention, when the vehicle is accelerated by the accelerator opening greater than the accelerator opening threshold, the high gear side speed is set as the next speed. If the upshift to the next gear stage is approved based on the shift line after pre-selection, the engine speed after the predicted time is sequentially predicted, and the engine speed after the predicted time does not reach the upper limit rotation threshold. In the meantime, the upshift to the next gear is prohibited, and when the engine speed after the predicted time reaches the upper limit rotation threshold, the upshift to the next gear is allowed.
Until the shift up to the next gear is completed, the vehicle continues to accelerate at the current gear and the engine speed also increases. When the acceleration is abrupt, the engine changes before the clutch is switched to the next gear. There is a case where the rotational speed enters a torque limit region of the engine, that is, a region where the engine starts to decrease in torque due to an increase in rotation. At this time, a shift to the next gear stage is performed while the torque is reduced, and a shock with a feeling of deceleration is generated, and as a countermeasure, the shift line is set to shift up to the next gear stage earlier. As a result, the acceleration due to the current gear position, which is a low gear, is shortened, so that the driver does not have the acceleration feeling intended.

In the present invention, since the upshift to the next gear stage is prohibited / permitted depending on whether the engine speed after the predicted time reaches the upper limit rotation threshold, the upshift to the next gear stage is performed as much as possible. A good acceleration feeling can be realized by delaying and continuing the vehicle acceleration at the current gear position, and the engine speed can be reliably prevented from entering the torque limit area to prevent the shock caused by this. Can do.
According to the control apparatus for a dual clutch type automatic transmission according to the second aspect of the present invention, in addition to the first aspect, at the time of shifting up to the next shift stage, at least a predicted time is set as a required time for clutch switching, and the predicted time Shifting to the next shift stage is prohibited because up-shifting is prohibited / permitted depending on whether the subsequent engine speed reaches the upper limit rotation threshold set at a lower speed than the lower limit of the engine torque limit range. Up can be performed at a more appropriate timing.

It is a whole lineblock diagram showing the control device of the dual clutch type automatic transmission of an embodiment. It is a flowchart which shows the upshift control routine which ECU performs. It is a flowchart which shows the upshift approval determination routine which ECU performs. It is a figure which shows the shift map in which the upshift line and the upper limit rotation threshold value were set. It is a flowchart which shows the upshift permission determination routine which ECU performs. It is a flowchart which shows the accelerator opening determination routine which ECU performs. It is a time chart which shows the speed change condition by the control device of the embodiment when it is determined that the upshift is made during vehicle acceleration. It is a time chart which shows the speed change condition by the control apparatus of a prior art when it is determined that the upshift is made during vehicle acceleration.

Hereinafter, an embodiment of a control device for a dual clutch automatic transmission embodying the present invention will be described.
FIG. 1 is an overall configuration diagram showing a control device for a dual clutch type automatic transmission according to the present embodiment. A vehicle is equipped with a diesel engine (hereinafter referred to as an engine) 1 as a driving power source. The engine 1 is configured as a so-called common rail type engine that supplies high-pressure fuel accumulated in a common rail by a pressurizing pump to the fuel injection valve of each cylinder and injects the fuel into the cylinder as the fuel injection valve opens.

An output shaft 1a of the engine 1 protrudes rearward of the vehicle (rightward in the figure) and is connected to an input shaft 2a of an automatic transmission (hereinafter simply referred to as a transmission) 2. The transmission 2 has 12 forward speeds (1st to 12th speeds) and 1 reverse speed. After the power of the engine 1 is input to the transmission 2 through the input shaft 2a, the transmission 2 is driven in accordance with the speed. The speed is changed and transmitted from the output shaft 2b to the drive wheel (not shown).
Needless to say, the gear position of the transmission 2 is not limited to the above and can be arbitrarily changed.

The transmission 2 is configured as a so-called dual clutch transmission. The details of the dual clutch transmission are described in, for example, Japanese Patent Application Laid-Open No. 2009-035168, and therefore only a brief description is given in the present embodiment. For this reason, FIG. 1 shows the transmission 2 in a schematic representation different from the actual mechanism, and the configuration and operating state of the transmission 2 will also be conceptually described in the following description.
As is well known, a dual clutch type transmission is provided with an odd-numbered gear stage and an even-numbered gear stage as mutually independent power transmission systems, and when one of them is transmitting power, the other is predicted next. By switching to the gear in advance, the system completes the switch to the next gear without interrupting power transmission.

That is, as shown in FIG. 1, a gear mechanism G1 having an odd number of gears (1, 3, 5, 7, 9, 11) is connected to the input shaft 2a of the transmission 2 via the clutch C1. At the same time, a gear mechanism G2 composed of even-numbered gears (2, 4, 6, 8, 10, 12th speed) is connected via the clutch C2, and the output side of these gear mechanisms G1, G2 is the same as described above. It is connected to the output shaft 2b.
Accordingly, the transmission 2 includes a power transmission system including the clutch C1 and the gear mechanism G1 and a power transmission system including the clutch C2 and the gear mechanism G2, which are independent from each other.

Here, in order to improve the space efficiency in the transmission 2, both the clutches C1 and C2 are double-sided with the clutch C1 on the odd speed side set as the inner peripheral side and the clutch C2 on the even speed stage side set as the outer peripheral side. It is arranged. Therefore, in the following description, the odd-numbered speed side clutch C1 is referred to as an inner clutch, and the even-numbered speed side clutch C2 is referred to as an outer clutch.
A hydraulic cylinder 3 is connected to each of the inner clutch C1 and the outer clutch C2, and both hydraulic cylinders 3 are connected to a hydraulic supply source 6 via an oil passage 5 in which an electromagnetic valve 4 is interposed. When the solenoid valve 4 is opened, hydraulic oil is supplied from the hydraulic supply source 6 to the hydraulic cylinder 3 via the oil passage 5, and the hydraulic cylinder 3 is operated to switch the corresponding clutches C1 and C2 from the connected state to the disconnected state. . On the other hand, when the solenoid valve 4 is closed, the hydraulic cylinder 3 is not operated due to the stop of the supply of hydraulic oil, so that the clutches C1 and C2 are switched from a disconnected state to a connected state by a pressure spring (not shown).

The driving method of the clutches C1 and C2 is not limited to this, and for example, air driving may be adopted instead of hydraulic driving.
Further, the gear shift unit 7 is provided in each of the gear mechanism G1 for odd-numbered gears and the gear mechanism G2 for even-numbered gears of the transmission 2. Although not shown, the gear shift unit 7 incorporates a plurality of hydraulic cylinders that operate shift forks corresponding to the respective gear positions in the gear mechanisms G1 and G2, and a plurality of electromagnetic valves that operate each hydraulic cylinder. The gear shift unit 7 is connected to the above-described hydraulic supply source 6 through an oil passage 8, and hydraulic oil from the hydraulic supply source 6 is supplied to a corresponding hydraulic cylinder in accordance with the opening and closing of each solenoid valve. When the shift fork is switched by operating, the gear stages of the corresponding gear mechanisms G1 and G2 are switched according to the switching operation.

Since the truck of the present embodiment is premised on starting at the second speed, each speed is sequentially switched to the upshift side or the downshift side at the second speed or higher when the vehicle is accelerated or decelerated.
At the time of this shifting, the state of connection / disconnection of the inner clutch C1 and the outer clutch C2 is always switched in the reverse direction. For this reason, when one of the gears G1 and G2 corresponding to the gears G1 and G2 is connected and the power is transmitted, the other clutch C1 and C2 is disengaged. The gear mechanisms G1 and G2 are in a state where none of the gears transmit power. Therefore, the other gear mechanisms G1 and G2 can be switched in advance to the next gear position (the gear position on the high gear side or the low gear side adjacent to the current gear position) (hereinafter, this operation is referred to as preselection). Then, when the shift timing is reached, the shift is completed without interrupting power transmission by reversing the connection / disconnection state of the inner clutch C1 and the outer clutch C2.

In the passenger compartment, an input / output device (not shown), a storage device (ROM, RAM, etc.) for storing control programs and control maps, an ECU (control unit) equipped with a central processing unit (CPU), a timer counter, etc. 21 is installed, and comprehensive control of the engine 1, the transmission 2, the inner clutch C1, and the outer clutch C2 is performed.
On the input side of the ECU 21, an engine rotation speed sensor 22 for detecting the rotation speed Ne of the engine 1, a clutch rotation speed sensor 23 for detecting the rotation speeds Ncl and Nc2 on the output side of the inner clutch C1 and the outer clutch C2, and a driver's seat A lever position sensor 24 that detects the switching position of the provided change lever 9, a gear position sensor 25 that detects the gear position of the gear mechanisms G1 and G2, an accelerator sensor 27 that detects the opening degree Acc of the accelerator pedal 26, and a transmission Sensors such as a vehicle speed sensor 28 that are provided on the output shaft 2b and detect the vehicle speed V are connected.

The output side of the ECU 21 is connected to the electromagnetic valves 4 of the clutches C1 and C2, the electromagnetic valves of the gear shift unit 7, and the like. A fuel injection valve or the like is connected.
In addition, you may make it provide ECU for engine control separately from ECU21, for example, without controlling comprehensively by single ECU21 in this way.

  For example, based on the engine speed Ne detected by the engine speed sensor 22 and the accelerator opening Acc detected by the accelerator sensor 27, the ECU 21 determines the rail pressure of the common rail accumulated by the pressure pump from a map (not shown). The fuel injection amount to each cylinder is calculated, and the fuel injection timing is calculated from a map (not shown) based on the engine speed Ne and the fuel injection amount Q. The pressurizing pump is driven and controlled based on these calculated values, and the engine 1 is operated while driving and controlling the fuel injection valves of the respective cylinders.

The ECU 21 selects the automatic transmission mode when the change of the change lever 9 to the D range (drive range) is detected by the lever position sensor 24, for example, and the vehicle speed detected by the accelerator opening Acc and the vehicle speed sensor 28. Based on V, shift control is executed to achieve a target shift stage determined from a shift map (for example, a map shown in FIG. 4 to be described later), and predicted from acceleration / deceleration of the vehicle prior to shifting to the target shift stage Preselect to the gear position.
For example, at the time of vehicle acceleration, the gear stage on the high gear side adjacent to the current gear stage is predicted as the next gear stage, and the hydraulic cylinder is operated by opening and closing predetermined electromagnetic valves of the gear mechanisms G1 and G2 that interrupt power transmission. To preselect the next gear position. Thereafter, when the engine rotational speed Ne that is increasing as the vehicle accelerates reaches a shift-up line (shift line) corresponding to the shift timing to the next shift stage on the shift map, the pre-selected next shift stage is reached. Make a decision to shift up. In response to this decision, the target shift speed is changed from the current shift speed to the next shift speed, and the clutches C1 and C2 of the gear mechanisms G1 and G2 on the side having the target shift speed are connected by the hydraulic cylinder 3. The target gear stage is achieved by disengaging the clutches C1 and C2 of the other gear mechanisms G1 and G2 (shifting execution means).

However, as described in [Problems to be Solved by the Invention], when sudden acceleration is performed by fully opening the accelerator under the condition that the load weight of the vehicle is small, the clutch switching for shifting up to the next shift stage is completed. Previously, the increasing engine speed Ne may enter the torque limit region of the engine 1. For this reason, a shock with a feeling of deceleration due to a decrease in torque and a shock with a feeling of acceleration occur, and if the shift-up line is changed to the low rotation side as a countermeasure, there is a problem that the driver cannot obtain the acceleration feeling intended. Arise.
In view of such a problem, in the present embodiment, when shifting up to the next shift stage is approved based on the shift-up line during vehicle acceleration, the shift to the next shift stage is performed according to the rising state of the engine 1. The up timing (more specifically, the clutch switching timing) is varied, thereby preventing the engine 1 from being blown up and solving the conflicting problems. Therefore, countermeasures executed by the ECU 21 will be described in detail below.

FIG. 2 is a flowchart showing a shift-up control routine executed by the ECU 21, which is executed in response to preselection to the next gear position by a preselect control routine (not shown). That is, in the preselect control routine, the next shift stage is predicted based on the acceleration / deceleration state of the vehicle, and the preselection to the predicted next shift stage is sequentially executed. Then, when the preselection on the upshift side is performed, the upshift control routine of FIG. 2 is executed, and as described above, the upshift decision is made on the condition that the engine speed Ne has reached the upshift line. Then, upshifting to the next gear position is executed.
In the case of the preselection on the downshift side, the downshift is executed based on the downshift decision according to a downshift control routine (not shown). However, the control contents of the downshift control routine are not different from those of the prior art, so the description thereof will be omitted. Hereinafter, the upshift control routine of FIG. 2 will be described in detail assuming that the upshift side preselection has been performed by the preselection control routine. Describe.

When the upshift control routine is started, the ECU 21 determines whether or not the current automatic transmission mode is in step S2. When the change lever 9 is switched to a range other than the D range and the manual shift mode is selected, the determination of No (No) is made and the routine is temporarily ended.
In the manual shift mode in which the driver switches the gear position, it is not necessary to prevent the engine 1 from being blown up, and in the manual shift mode, if the shift-up timing is varied regardless of the driver's intention, the driver feels strange. Therefore, the purpose is limited to the case where the automatic transmission mode is determined by detecting the D range.

When the determination in step S2 is Yes (affirmative), the process proceeds to step S4, and the upshift approval determination is executed. FIG. 3 is a flowchart showing the upshift approval determination routine. At this time, the ECU 21 proceeds to step S22 of FIG. 3 to determine whether the upshift approval condition is satisfied. The conditions for approval for upshifting are considered to be satisfied when the following requirements 1) to 3) are all satisfied.
1) The engine speed Ne has reached the upshift line.
2) The current gear position is other than the highest gear position.
3) The requirement to prohibit upshifting has not been established.
Requirement 1) is the original purpose of determining whether or not to shift up, and the engine rotational speed Ne that increases as the vehicle accelerates (correlates with the vehicle speed V via the gear ratio) moves to the next gear position on the shift map. This is to confirm that the shift timing corresponding to the vehicle speed V and the corresponding upshift line have been reached.

Requirement 2) is intended to exclude situations where the current gear position is the highest gear position and there is no room for upshifting. In addition, requirement 3) is intended to exclude situations where upshifting is prohibited in terms of shift control. The prohibition of upshifting includes, for example, the case where the target shift speed obtained from the shift map is corrected by fuzzy inference, or the case where there is an instruction to hold the gear stage or downshift for backup of fault diagnosis. This situation is excluded.
The determination content itself relating to requirement 1) is not different from that of the prior art, but there is room for varying the timing of upshifting to the next gear stage in accordance with the state of engine 1 that is a characteristic part of the present invention. In order to leave it, the upshift line is set on the low rotation side as compared with the prior art. Hereinafter, the setting state of the shift-up line of this embodiment will be described based on the shift map of FIG.

First, in FIG. 4, the prior art shift-up line is shown by a solid line. When the accelerator opening Acc is greater than or equal to the accelerator opening threshold Acc0, the accelerator is used for rapid vehicle acceleration using the high engine speed range. The shift-up line is set on the higher vehicle speed (higher rotation) side compared to the region below the opening degree threshold Acc0. In contrast to this prior art, the shift-up line of the present embodiment is set to be the same in the region below the accelerator opening threshold Acc0, while in the region above the accelerator opening threshold Acc0, only a predetermined rotational speed width is shown as indicated by a broken line. It is set to the low vehicle speed side.
Further, in the region where the accelerator opening Acc is equal to or larger than the accelerator opening threshold Acc0, the upper limit rotation threshold Ne0 is set so as to coincide with the prior art shift-up line. In the prior art, the upshift line is set at a lower rotation side than the lower limit of the torque limit region so that the engine speed Ne does not reach the lower limit of the torque limit region of the engine 1 during vehicle acceleration. The threshold value Ne0 is also located on the lower rotation side than the lower limit of the torque limit region. Then, as will be described below, the engine racing state of the engine 1 is determined within a determination region E between the upper limit rotation threshold value Ne0 and the upshift line.

Based on the upshift line set as described above, the requirement 1) is determined. If the upshift approval condition is not satisfied and the determination in step S22 in FIG. 3 is No, the upshift is continuously rejected in step S24. If the determination in step S22 is Yes due to the establishment of the upshift approval condition, The process proceeds to S26 and the upshift is approved.
Thereafter, the ECU 21 proceeds to step S6 in FIG. 2 and executes a shift-up permission determination. FIG. 5 is a flowchart showing a shift-up permission determination routine. At this time, the ECU 21 proceeds to step S32 in FIG. 5 and first performs accelerator opening determination.
FIG. 6 is a flowchart showing an accelerator opening degree determination routine. At this time, the ECU 21 proceeds to step S42 in FIG. In step S42, it is determined whether or not a state where the accelerator opening Acc is equal to or greater than the accelerator opening threshold Acc0 continues for a predetermined time. When the determination in step S42 is No, the accelerator opening flag F is reset (= 0) in step S44, and when the determination in step S42 is Yes, the accelerator opening flag F is set (= 1) in step S46.

Thereafter, the ECU 21 proceeds to step S34 in FIG. 5 and determines whether or not the upshift delay condition is satisfied. The shift-up delay condition is considered to be satisfied when the following requirements 4) to 6) are all satisfied.
4) The accelerator opening flag F is set.
5) The engine rotational speed Ne after the predicted time T has elapsed is less than the upper limit rotational threshold Ne0 (Ne <Ne0).
6) The current gear position is the target gear position.

Since the conditions for deciding to shift up have already been established at this point, requirement 4) confirms that the current driving point P0 (indicated by a circle) is within the determination region E in the shift map shown in FIG. It is the purpose. Requirement 5) is that the operating point (indicated by the mark ●) after the predicted time T predicted based on the rate of increase of the engine rotational speed Ne is within the determination region E (P1 ′ outside the determination region E) as indicated by P1. (Rotation rise prediction means). As the predicted time T, at least the time required from the change of the target gear stage described below to the completion of clutch switching is set. Requirement 6) is intended to confirm that the current shift stage before pre-selection is set as the target shift stage (before switching to the next shift stage).
When the shift-up delay condition is satisfied and the determination of Yes is made in step S34, the routine is terminated after prohibiting the shift-up in step S36. Each time Steps S32 and S34 are executed, the requirements 4) to 6) are sequentially determined. If any of the requirements is not satisfied and the determination in Step S34 is No due to failure of the upshift delay condition, the process proceeds to Step S38. To allow upshifting (shift up prohibition / permission means).

After that, the ECU 21 proceeds to step S8 in FIG. 2 and receives the shift-up permission, and the next shift speed obtained from the current shift speed based on the shift map with the permission to shift up (that is, the shift speed that has already been preselected and is settled). Change to In the subsequent step S10, clutch switching for reversing the connection / disconnection state of both clutches C1, C2 is performed based on the changed target shift speed. Thereafter, while the engine torque is raised by engine control in step S12, the clutch C1 and C2 on the side corresponding to the next gear position in step S14 are subjected to the half-clutch state so that the engine rotational speed Ne and the clutch rotational speeds Ncl and Nc2 are After entering the synchronized state, the routine is terminated.
Due to the processing of the ECU 21 described above, the upshift to the next shift stage during vehicle acceleration is executed through the following procedure.
FIG. 7 is a time chart showing a shift state when it is determined that the upshift is made during vehicle acceleration.

After the pre-selection to the next gear stage is completed, when the engine speed Ne that is increasing as the vehicle accelerates reaches the shift-up line corresponding to the shift timing to the next gear stage on the shift map, the pre-selected next A decision to shift up to the gear position is made (point a in FIG. 7). At this time, the map-indicated gear position on the shift map is switched to the next gear position on the high gear side preselected from the current gear position, and in the prior art, the target gear position is immediately shifted to the next gear speed following the map-indicated gear position. The shift up is started by switching to the stage.
On the other hand, in this embodiment, even if the upshift decision is made, the upshift is prohibited as long as the upshift delay condition is satisfied (period b in FIG. 7), and the target shift stage is changed. Without being maintained at the current gear. If the engine speed Ne gradually increases and approaches the upper limit rotation threshold value Ne0, and it is predicted that the engine speed Ne after the elapse of the prediction time T will reach the upper limit rotation threshold value Ne0 based on the increase rate, the above requirement 5) is satisfied. Based on the fact that the shift-up delay condition is not satisfied, the shift-up is permitted, the target shift stage is switched to the next shift stage that is the map instruction shift stage, and the upshift is started (point c in FIG. 7).

As long as the accelerator operation continues even after the shift up is started, the engine rotation speed Ne continues to increase and reaches the upper limit rotation threshold value Ne0 after the prediction time T has elapsed (point d in FIG. 7). At this time, the switching of the clutches C1 and C2 has been completed, and the clutches C1 and C2 on the current gear stage on which power has been transmitted until then are completely disconnected and the clutches C1 and C2 on the next gear stage are so-called. It is controlled until just before the half clutch by precharge.
At this time, the engine control is temporarily interrupted, but is resumed immediately after that and the engine torque is raised. In parallel with this, the clutches C1 and C2 on the next shift stage side pass through the half clutch and the engine speed Ne. And the clutch rotational speeds Ncl and Nc2 are synchronized with each other, so that power transmission via the next gear stage is started.

  Thus, when the engine speed Ne reaches the upper limit rotation threshold value Ne0, the clutch switching is completed, and the engine rotation speed Ne is changed to the upper limit rotation threshold value in accordance with the switching from the current gear position to the next gear position on the high gear side. It begins to decrease with a peak near Ne0. Therefore, it is possible to avoid a situation where the engine speed Ne enters the torque limit region that exists on the higher rotation side than the upper limit rotation threshold value Ne0 (corresponding to the shift-up line of the prior art) due to the rising of the engine 1. As a result, it is possible to suppress a shock that occurs due to a decrease in torque. Further, prevention of the engine 1 from being blown up leads to suppression of over-rotation, which can contribute to improvement in fuel consumption and noise reduction.

Then, by determining the shift-up permission timing based on the engine speed Ne after the prediction time T has elapsed, the clutch switching is completed when the engine speed Ne always reaches the vicinity of the upper limit rotation threshold Ne0. For this reason, not only can the situation where the engine rotational speed Ne enters the torque limit region of the engine 1 as described above be prevented, but also the vehicle acceleration at the current shift stage is continued by delaying the shift-up to the next shift stage as much as possible. Therefore, it is possible to improve the drivability of the vehicle by realizing the good acceleration feeling required by the driver.
In addition, since the prohibition / permission of upshifting based on the above upshift delay conditions is executed only in the automatic transmission mode, the upshifting can be performed at the timing intended by the driver as usual during vehicle acceleration in the manual transmission mode. it can.

On the other hand, if the driver does not intend to accelerate suddenly from the beginning of acceleration of the vehicle and the accelerator opening Acc is small, the requirement 4) regarding the accelerator opening flag F is not satisfied, and therefore the shift-up delay condition is satisfied from the beginning of acceleration. do not do. Therefore, at this time, the upshift is permitted immediately after the upshift approval condition is satisfied, and the upshift is performed according to the upshift line as usual.
Further, when the driver loses the will of rapid acceleration during acceleration and the accelerator is loosened, the upshift is permitted and the upshift is performed immediately when the upshift delay condition is not satisfied. Therefore, in a situation where these rapid accelerations are not required, the engine 1 can be operated in an appropriate rotation range in which over-rotation is suppressed by quickly executing the shift-up without delay.

This is the end of the description of the embodiment, but the aspect of the present invention is not limited to this embodiment. For example, in the above embodiment, the control device for the dual clutch automatic transmission 2 applied to the common rail diesel engine 1 is embodied, but the type of the engine 1 is not limited to this. For example, a conventional diesel engine that controls fuel injection to each cylinder in accordance with the operation of the control rack may be used, or a gasoline engine may be used. In any case, by taking the same measures as in the above embodiment, the vehicle It is possible to prevent an adverse effect when the engine speed Ne enters the torque limit region during acceleration.
In the above embodiment, the required time required to complete the switching of the clutches C1 and C2 is set as the predicted time T, and the engine speed Ne corresponding to the shift-up line of the prior art is set as the upper limit rotation threshold Ne0. The value is not limited to this. For example, the predicted time T may be set to a value that has nothing to do with the time required for clutch switching, and the upper limit rotation threshold value Ne0 is at least a value on the lower rotation side than the lower limit of the torque limit region of the engine 1. You only have to set it.

1 Engine 21 ECU
(Shifting execution means, rotation rise prediction means, shift up prohibition / permission means)
Acc0 Accelerator opening threshold Ne0 Upper limit rotation threshold T Estimated time G1, G2 Gear mechanism C1 Inner clutch C2 Outer clutch

Claims (2)

A pair of gear mechanisms composed of a plurality of gear speeds are connected to the engine side via respective clutches, and the other gear mechanism is connected during power transmission via the gear speed of the corresponding one gear mechanism by connecting one clutch. Preselection to switch to the next shift stage is executed in advance, and after the preselection, the shift to the next shift stage is approved when the rotational speed of the engine crosses a preset shift line, and the shift execution means is based on the shift determination In the control device of the dual clutch type automatic transmission that completes switching to the next shift stage by reversing the connection / disconnection state of both clutches by
At the time of vehicle acceleration when the accelerator opening is equal to or greater than a predetermined accelerator opening threshold, the upshift to the next shift stage is performed based on the shift line after the high gear shift stage is preselected as the next shift stage. A rotation increase prediction means for sequentially predicting a value after a preset prediction time of the engine rotation speed rising with the acceleration of the vehicle when passed.
While the engine rotation speed after the prediction time predicted by the rotation increase prediction means does not reach the preset upper limit rotation threshold, the shift execution means is prohibited from shifting up to the next shift stage, and the prediction When the engine speed after the time reaches the upper limit rotation threshold value, the dual clutch type is provided with a shift-up prohibition / permission unit that permits the shift execution unit to shift up to the next shift stage. Control device for automatic transmission.   As the predicted time, at least the time required for clutch switching at the time of shifting up to the next shift stage by the shift execution means is set, and as the upper limit rotation threshold, at least a torque limit region in which the engine starts to decrease torque due to increased rotation is set. 2. The control device for a dual clutch automatic transmission according to claim 1, wherein a value on a lower rotation side than the lower limit is set.

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