JP5860150B2 - Automatic transmission for vehicles - Google Patents

Description

  The present invention relates to an automatic transmission for a vehicle having a coast stop function.

2. Description of the Related Art For the purpose of improving fuel consumption, vehicles equipped with a function (so-called idling stop function) that automatically stops an engine (drive source) when the vehicle stops are known.
In recent years, for the purpose of further improving the fuel efficiency, a vehicle having a function of stopping the engine at the time of coasting at a low speed (so-called coast stop function) where the vehicle may stop even if the vehicle is traveling has been proposed. For example, Patent Document 1 discloses a technique for starting a coast stop when the vehicle speed is equal to or lower than a coast stop permission vehicle speed (coast stop permission vehicle speed).

In the automatic transmission of this Patent Document 1, the coast stop permission vehicle speed is set on the low vehicle speed range where no shift is performed, and the coast stop function operates only in an extremely low vehicle speed region where no shift occurs. It has become.
Here, if the coast stop permission vehicle speed is set to a higher vehicle speed range in response to the recent increase in demand for fuel efficiency, the coast stop function is activated even in a region where a shift can be performed.
As a result, the coast stop function is activated during the shift transition and the shift is disturbed, and the extension of the shift or the occurrence of a shift shock resulting from the shift may cause the driver to feel uncomfortable.

That is, when the coast stop permission vehicle speed is increased, the coast stop permission vehicle speed and the auto downshift line are close to each other.
(1) After reaching the coast stop permission vehicle speed after the shift lever is operated (engine brake request, etc.) during deceleration,
(2) The coast stop function is activated during a shift transition, such as when the vehicle deceleration increases and the coast stop permission vehicle speed is reached during shifting based on the auto downshift line. Sometimes.

If coast stop is executed during such shift transition, the mechanical oil pump driven by the engine stops during coast stop, so that sufficient hydraulic pressure cannot be secured. There is a problem that the shift is delayed or the shift shock occurs, for example, the progress of the shift is reversed from the direction in which the gear ratio has changed or the shift is stagnant.
Even when the electric oil pump is driven during the coast stop, the capacity of the electric oil pump is generally smaller than the capacity of the mechanical oil pump, such as the hydraulic pressure from the mechanical oil pump. Since the hydraulic pressure for bringing the frictional engagement element into the engaged state cannot be increased at a sufficient speed, the problem that the speed change is delayed cannot be solved.

  Therefore, an object of the present invention is to solve the above problems.

JP 2010-164143 A

The present invention
A power transmission unit that transmits the rotational driving force of the drive source to the drive wheels at a gear ratio determined according to the combination of the engagement state and the release state of the plurality of friction engagement elements;
A hydraulic source driven by the drive source;
Drive source control means for stopping the drive source when a predetermined stop condition is satisfied while the vehicle is decelerating, and
The drive source control means is an automatic transmission for a vehicle having a configuration in which the drive source is not stopped when the power transmission unit is shifting even when the stop condition is satisfied.

According to the present invention, even when a predetermined stop condition is satisfied, the drive source is not stopped when the power transmission unit is shifting.
Therefore, even if the drive source is stopped on the high vehicle speed range side where the shift can be performed, the hydraulic pressure supplied from the drive source does not decrease during the shift and does not cause the shift.
As a result, problems such as problems caused by gear shifting problems, problems that the change direction of the gear ratio is reversed in the middle of gear shifting, and a shock occurs, problems that the gear shifting speed changes during gear shifting, and the gear shifting is prolonged, etc. Since generation | occurrence | production can be prevented suitably, it can prevent a driver | operator feeling uncomfortable about a shift behavior. In addition, since the drive source can be stopped even on the high vehicle speed range side, the opportunity to stop the drive source can be increased, and thereby an effect of improving fuel consumption can be expected.

1 is a schematic configuration diagram of a vehicle equipped with a continuously variable transmission according to an embodiment. It is a figure explaining the structure of the controller of the continuously variable transmission concerning embodiment. It is explanatory drawing which shows an example of the shift map of the continuously variable transmission concerning embodiment. It is explanatory drawing of the hydraulic control circuit of the continuously variable transmission concerning embodiment. It is a flowchart of execution determination of the coast stop in the case of 1st Embodiment. It is a timing chart explaining operation | movement of a transmission. It is a flowchart of execution determination of the coast stop in the case of 2nd Embodiment. It is a timing chart explaining operation | movement of a transmission. It is a timing chart explaining operation | movement of a transmission. It is a flowchart of execution determination of the coast stop concerning a modification. It is a figure explaining the shift map concerning a prior art example.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, the “transmission ratio” of a transmission mechanism is a value obtained by dividing the input rotational speed of the transmission mechanism by the output rotational speed of the transmission mechanism. The “lowest speed ratio” is the maximum speed ratio of the transmission mechanism, and the “highest speed ratio” is the minimum speed ratio of the transmission mechanism.

  FIG. 1 is a schematic configuration diagram of a coast stop vehicle according to an embodiment of the present invention. This vehicle includes an engine 1 as a drive source, and the output rotation of the engine 1 is a torque converter 2 with a lock-up clutch, a first gear train 3, a continuously variable transmission (hereinafter simply referred to as “transmission 4”), This is transmitted to the drive wheels 7 via the second gear train 5 and the final reduction gear 6. The second gear train 5 is provided with a parking mechanism 8 that mechanically locks the output shaft of the transmission 4 at the time of parking.

  The transmission 4 includes a mechanical oil pump 10 m that receives rotation of the engine 1 and is driven by using a part of the power of the engine 1, and an electric oil pump 10 e that is driven by receiving power supply from the battery 13. Is provided. The electric oil pump 10e includes an oil pump main body, an electric motor and a motor driver that rotationally drive the oil pump main body, and can control the operation load to an arbitrary load or in multiple stages. Further, the transmission 4 is provided with a hydraulic control circuit 11 that regulates the hydraulic pressure (hereinafter referred to as “line pressure PL”) from the mechanical oil pump 10 m or the electric oil pump 10 e and supplies it to each part of the transmission 4. It has been.

  The transmission 4 includes a belt-type continuously variable transmission mechanism (hereinafter referred to as “variator 20”) and an auxiliary transmission mechanism 30 provided in series with the variator 20. “Provided in series” means that the variator 20 and the auxiliary transmission mechanism 30 are provided in series in the power transmission path from the engine 1 to the drive wheels 7. The auxiliary transmission mechanism 30 may be directly connected to the output shaft of the variator 20 as in this example, or may be connected via another transmission or power transmission mechanism (for example, a gear train). Alternatively, the auxiliary transmission mechanism 30 may be connected to the front stage (input shaft side) of the variator 20.

  The variator 20 includes a primary pulley 21, a secondary pulley 22, and a V-belt 23 that is wound around these. The primary pulley 21 and the secondary pulley 22 are each a fixed conical plate, a movable conical plate that is arranged with a sheave surface facing the fixed conical plate, and forms a V-groove between the fixed conical plate, Hydraulic cylinders 23a and 23b are provided on the back surface of the movable conical plate to displace the movable conical plate in the axial direction. When the hydraulic pressure supplied to the hydraulic cylinders 23a and 23b is adjusted, the width of the V groove changes, the contact radius between the V belt 23 and each pulley 21 and 22 changes, and the transmission ratio of the variator 20 changes steplessly. .

  The subtransmission mechanism 30 is a transmission mechanism having two forward speeds and one reverse speed. The sub-transmission mechanism 30 is connected to a Ravigneaux type planetary gear mechanism 31 in which two planetary gear carriers are connected, and a plurality of friction elements connected to a plurality of rotating elements constituting the Ravigneaux type planetary gear mechanism 31 to change their linkage state. Fastening elements (Low brake 32, High clutch 33, Rev brake 34) are provided. When the hydraulic pressure supplied to each of the frictional engagement elements 32 to 34 is adjusted and the engagement / release state of each of the frictional engagement elements 32 to 34 is changed, the gear position of the auxiliary transmission mechanism 30 is changed.

  For example, if the Low brake 32 is engaged and the High clutch 33 and the Rev brake 34 are released, the gear position of the subtransmission mechanism 30 is the first speed. If the high clutch 33 is engaged and the low brake 32 and the rev brake 34 are released, the speed stage of the subtransmission mechanism 30 becomes the second speed having a smaller speed ratio than the first speed. Further, if the Rev brake 34 is engaged and the Low brake 32 and the High clutch 33 are released, the shift speed of the subtransmission mechanism 30 is reverse. In the following description, the transmission 4 is expressed as “the transmission 4 is in the low speed mode” when the shift speed of the auxiliary transmission mechanism 30 is the first speed, and “the transmission 4 is in the high speed mode” when it is the second speed. Express.

  Each frictional engagement element is provided on the power transmission path at the front stage or the rear stage of the variator 20, and enables transmission of power to the transmission 4 when both are engaged, and disables transmission of power to the transmission 4 when released. To do.

  The controller 12 is a controller that controls the engine 1 and the transmission 4 in an integrated manner. As shown in FIG. 2, the CPU 12, a storage device 122 including a RAM / ROM, an input interface 123, an output interface 124, The bus 125 interconnects these components.

  The input interface 123 includes an output signal of an accelerator opening sensor 41 that detects an accelerator opening APO that is an operation amount of an accelerator pedal, an input rotation speed of the transmission 4 (= rotation speed of the primary pulley 21, hereinafter, “primary rotation”). The output signal of the rotational speed sensor 42 for detecting the speed Npri, the output signal of the vehicle speed sensor 43 for detecting the vehicle speed VSP, the output signal of the line pressure sensor 44 for detecting the line pressure PL, and the position of the shift lever. The output signal of the inhibitor switch 45, the output signal of the brake hydraulic pressure sensor 46 for detecting the brake hydraulic pressure, the output signal of the turbine rotational speed sensor 47 for detecting the rotational speed of the output shaft of the torque converter 2, and the like are input.

  The storage device 122 stores a control program for the engine 1, a shift control program for the transmission 4, and various map tables used in these programs. The CPU 121 reads and executes a program stored in the storage device 122, performs various arithmetic processes on various signals input via the input interface 123, and performs fuel injection amount signal, ignition timing signal, throttle opening. A degree signal, a shift control signal, and a drive signal of the electric oil pump 10e are generated, and the generated signals are output to the engine 1, the hydraulic control circuit 11, and the motor driver of the electric oil pump 10e via the output interface 124. Various values used in the arithmetic processing by the CPU 121 and the arithmetic results are appropriately stored in the storage device 122.

  The hydraulic control circuit 11 includes a plurality of flow paths and a plurality of hydraulic control valves. The hydraulic control circuit 11 controls a plurality of hydraulic control valves on the basis of the shift control signal from the controller 12 to switch the hydraulic pressure supply path, and at the same time, obtains the necessary hydraulic pressure from the hydraulic pressure generated by the mechanical oil pump 10m or the electric oil pump 10e. It is prepared and supplied to each part of the transmission 4. As a result, the gear ratio of the variator 20 and the gear position of the subtransmission mechanism 30 are changed, and the transmission 4 is shifted.

  FIG. 3 shows an example of the shift map stored in the storage device 122. Based on this shift map, the controller 12 controls the variator 20 and the subtransmission mechanism 30 according to the driving state of the vehicle (in this embodiment, the vehicle speed VSP, the primary rotational speed Npri, and the accelerator opening APO).

  In this shift map, the operating point of the transmission 4 is defined by the vehicle speed VSP and the primary rotational speed Npri. The slope of the line connecting the operating point of the transmission 4 and the zero point of the lower left corner of the transmission map is the transmission ratio of the transmission 4 (the overall transmission ratio obtained by multiplying the transmission ratio of the variator 20 by the transmission ratio of the subtransmission mechanism 30; , Referred to as “through gear ratio”). Similar to the shift map of the conventional belt type continuously variable transmission, a shift line is set for each accelerator opening APO, and the shift of the transmission 4 is selected according to the accelerator opening APO. According to the shift line. For simplicity, FIG. 3 shows a full load line (shift line when accelerator opening APO = 8/8), partial line (shift line when accelerator opening APO = 4/8), coast line ( Only the shift line when the accelerator opening APO = 0/8 is shown.

  When the transmission 4 is in the low speed mode, the transmission 4 can be obtained by setting the low speed mode Low line obtained by setting the transmission ratio of the variator 20 to the lowest transmission ratio, and the low speed mode obtained by setting the transmission ratio of the variator 20 to the highest transmission ratio. The speed can be changed between the highest lines. In this case, the operating point of the transmission 4 moves in the A region and the B region. On the other hand, when the transmission 4 is in the high speed mode, the transmission 4 can be obtained by setting the maximum speed line of the high speed mode obtained by setting the transmission ratio of the variator 20 as the lowest transmission ratio and the transmission ratio of the variator 20 as the highest transmission ratio. It is possible to shift between the high-speed mode highest line. In this case, the operating point of the transmission 4 moves in the B region and the C region.

  The gear ratio of each gear stage of the subtransmission mechanism 30 is such that the gear ratio corresponding to the low speed mode highest line (low speed mode maximum high gear ratio) corresponds to the gear ratio corresponding to the high speed mode lowest line (high speed mode lowest gear ratio). ) Is set to be smaller than. Accordingly, the range of the through speed ratio of the transmission 4 that can be achieved in the low speed mode (“low speed mode ratio range” in the figure) and the range of the through speed ratio of the transmission 4 that can be taken in the high speed mode (“high speed mode” in the figure). Ratio range ”) partially overlaps and the operating point of the transmission 4 is in the B region sandwiched between the high-speed mode lowest line and the low-speed mode highest line, the transmission 4 is in the low-speed mode and the high-speed mode. Either mode can be selected.

  Further, on this shift map, a mode switching shift line for shifting the subtransmission mechanism 30 is set so as to overlap the low speed mode highest line. The through speed change ratio (hereinafter referred to as “mode change speed change ratio mRatio”) corresponding to the mode change speed change line is set to a value equal to the low speed mode highest speed change ratio. The reason why the mode switching shift line is set in this way is that the smaller the gear ratio of the variator 20 is, the smaller the input torque to the subtransmission mechanism 30 is, so that a shift shock when shifting the subtransmission mechanism 30 can be suppressed. .

  When the operating point of the transmission 4 crosses the mode switching speed line, that is, the actual value of the through speed ratio (hereinafter referred to as “actual through speed ratio Ratio”) changes across the mode switching speed ratio mRatio. In this case, the controller 12 performs the coordinated shift described below and switches between the high speed mode and the low speed mode.

  In the coordinated shift, the controller 12 shifts the auxiliary transmission mechanism 30 and changes the transmission ratio of the variator 20 in a direction opposite to the direction in which the transmission ratio of the auxiliary transmission mechanism 30 changes. At this time, the inertia phase in which the gear ratio of the auxiliary transmission mechanism 30 actually changes and the period in which the gear ratio of the variator 20 changes are synchronized. The reason why the speed ratio of the variator 20 is changed in the direction opposite to the speed ratio change of the auxiliary speed change mechanism 30 is to prevent the change in the input rotation caused by the step in the actual through speed ratio Ratio from causing the driver to feel uncomfortable. Because.

  Specifically, when the actual through speed ratio Ratio of the transmission 4 changes over the mode switching speed ratio mRatio from the Low side to the High side, the controller 12 changes the speed stage of the subtransmission mechanism 30 from the first speed to the second speed. The speed is changed (1-2 shift), and the speed ratio of the variator 20 is changed to Low.

Conversely, when the actual through speed ratio Ratio of the transmission 4 changes from the High side to the Low side, the controller 12 changes the speed stage of the subtransmission mechanism 30 from the second speed to the first speed. While changing (2-1 shift), the gear ratio of the variator 20 is changed to the High side.
In the transmission 4 according to the present embodiment, when the coast stop is being executed, the shift speed of the auxiliary transmission mechanism 30 is maintained at the first speed or the second speed until the vehicle stops. Yes. Therefore, when the coast stop is being executed and the shift speed of the auxiliary transmission mechanism 30 is maintained at the second speed, the actual through speed ratio Ratio of the transmission 4 is set to the mode switching speed ratio mRatio from the High side. Even if it changes across the Low side, the shift from the second speed to the first speed is not performed.

  Further, the controller 12 performs coast stop control described below in order to suppress fuel consumption.

The coast stop control is a control that suppresses fuel consumption by automatically stopping the engine 1 (coast stop) while the vehicle is traveling in a low vehicle speed range. The fuel cut control executed when the accelerator is off is common in that the fuel supply to the engine 1 is stopped, but the lockup clutch is released and the power transmission path between the engine 1 and the transmission 4 is disconnected. The difference is that the rotation of the engine 1 is completely stopped.
In this case, in the transmission 4 according to the embodiment, when the coast stop is executed, the frictional engagement element (for example, the High clutch 33) is held in the engaged state until the vehicle stops. ing.

  In executing the coast stop, the controller 12 first determines the following conditions a to d, for example.

a: The foot is released from the accelerator pedal (accelerator opening APO = 0)
b: The brake pedal is depressed (brake hydraulic pressure is greater than or equal to a predetermined value)
c: Vehicle speed is a predetermined low vehicle speed (coast stop permission vehicle speed: for example, 16 km / h) or less d: Sub-transmission mechanism 30 is not shifting (not in the middle of changing the combination of the engagement state and the release state of the friction engagement element)
Here, the conditions a to c are conditions for determining whether the driver intends to stop.

  The controller 12 determines that the stop condition (coast stop condition) of the engine 1 is satisfied when all the conditions a to c are satisfied, and stops the engine 1 when the condition d is satisfied in addition to the conditions a to c. (Start coast stop).

  In the coast stop, the fuel supply to the engine 1 is stopped and the engine 1 is automatically stopped. When the engine 1 is stopped, the mechanical oil pump 10m driven by the power of the engine 1 is also stopped, so that the discharge pressure of the mechanical oil pump 10m decreases and finally becomes zero.

  Further, when the coast stop is started, the driving of the electric oil pump 10e is started. When the hydraulic pressure generated by the electric oil pump 10e becomes larger than the hydraulic pressure generated by the mechanical oil pump 10m, the electric oil pump 10e The generated hydraulic pressure is supplied to the hydraulic cylinders 23 a and 23 b and the auxiliary transmission mechanism 30. The hydraulic pressure supplied to the hydraulic cylinders 23a and 23b changes the variator 20 to a gear ratio according to the vehicle speed at that time until the vehicle decelerates and stops.

Further, when the coast stop is started, the controller 12 thereafter maintains the engagement state of the friction engagement element (the high clutch 33 or the low brake 32) of the auxiliary transmission mechanism 30 until the vehicle stops. Then, when the vehicle stops while maintaining the engaged state of the high clutch 33, the controller 12 releases the high clutch 33 and then engages the low brake 32 in preparation for the start of the vehicle.
Therefore, the gear position of the auxiliary transmission mechanism 30 is held at the second speed from the start of the coast stop until the vehicle stops, and then changed to the first speed when the vehicle stops.
Note that when the vehicle stops while the engaged state of the Low brake 32 is maintained, the engaged state of the Low brake 32 is continuously maintained in preparation for the start of the vehicle.

  Note that the determination of whether the conditions a to c are satisfied even during the coast stop is continued. If any one of them is not satisfied, the coast stop condition is not satisfied, and the controller 12 restarts the fuel supply to the engine 1 to restart the engine 1 and the mechanical oil pump 10m generates sufficient hydraulic pressure. When this happens, the electric oil pump 10e is stopped.

  FIG. 4 is an explanatory diagram showing the configuration of the hydraulic control circuit 11 of the present embodiment.

  The hydraulic control circuit 11 includes a mechanical oil pump 10 m that is driven by the driving force of the engine 1. The hydraulic pressure generated by the mechanical oil pump 10 m is adjusted to a predetermined line pressure by the pressure regulator valve 51 and is distributed to each part of the variator 20 and the subtransmission mechanism 30 via the oil passage 50.

  The hydraulic pressure generated by the mechanical oil pump 10 m is supplied to the torque converter 2 via the pressure regulator valve 51. This hydraulic pressure is used for torque transmission of the torque converter 2 and for engagement / release of the lock-up clutch.

  The line pressure of the oil passage 50 is supplied to the oil chamber of the hydraulic cylinder 23 b of the secondary pulley 22. The line pressure in the oil passage 50 is reduced by the pressure reducing valve 52 and supplied to the oil chamber of the hydraulic cylinder 23 a of the primary pulley 21. By adjusting the hydraulic pressure supplied to the oil chamber of the hydraulic cylinder 23a by the pressure reducing valve 52, the width of each V groove changes due to the differential pressure from the line pressure supplied to the oil chamber of the hydraulic cylinder 23b. The contact radius between the pulley 23 and the pulley changes, and the gear ratio of the variator 20 changes steplessly.

  Further, the line pressure in the oil passage 50 is supplied to the low brake 32 via the pressure reducing valve 53 and to the high clutch 33 via the pressure reducing valve 54 in the auxiliary transmission mechanism 30. The pressure reducing valve 53 controls the engagement force of the Low brake 32 by adjusting the hydraulic pressure supplied to the Low brake 32. The pressure reducing valve 54 controls the fastening force of the high clutch 33 by adjusting the hydraulic pressure supplied to the high clutch 33.

  An accumulator 60 is connected to the oil passage 56 between the pressure reducing valve 53 and the Low brake 32. The accumulator 60 stores hydraulic oil therein and relieves changes in the hydraulic pressure in the oil passage 56 with the hydraulic oil.

Specifically, when the hydraulic pressure is equal to or higher than a predetermined pressure, the hydraulic oil is stored in the accumulator 60. When the hydraulic pressure falls below a predetermined pressure, the hydraulic oil stored in the accumulator 60 is supplied to the oil passage 56 to delay the response of the oil pressure reduction in the oil passage 56.
Further, when the oil pressure in the oil passage 56 rises from a low state, the hydraulic oil is stored in the accumulator 60 and delays the response of the oil pressure in the oil passage 56 to rise. As a result, the response of the oil pressure in the oil passage 56 is delayed and the oil pressure is prevented from rising and falling rapidly, so that a shock at the time of engaging and releasing the Low brake 32 can be suppressed.

  For example, when the shift lever selection range is switched from the N position to the D position, hydraulic oil is supplied to the oil passage 56 connected to the Low brake 32 in order to fasten the friction engagement element of the Low brake 32. . At this time, if the frictional engagement element of the Low brake 32 is abruptly engaged, a shock is generated, so that the frictional engagement element of the Low brake 32 is abruptly engaged by the accumulator 60 provided in the oil passage 56. It is preventing.

  The controller 12 controls the pressure regulator valve 51 to adjust the line pressure. Further, the pressure reducing valve 52 is controlled to adjust the hydraulic pressure of the primary pulley 21 to the hydraulic cylinder 23a, thereby controlling the transmission ratio of the variator 20. In addition, the pressure reducing valve 53 is controlled to control the engaged state of the Low brake 32. Further, the engagement state of the high clutch 33 is controlled by controlling the pressure reducing valve 54.

  The mechanical oil pump 10 m is driven by the rotation of the engine 1. While the engine 1 is rotating, the mechanical oil pump 10 m always rotates and generates hydraulic pressure necessary for the operation of the transmission 4. Since the transmission 4 requires hydraulic pressure in preparation for the start of the vehicle even when the vehicle is stopped, the line pressure is generated by driving the mechanical oil pump 10m when the engine 1 is rotating when the vehicle is stopped.

  On the other hand, when the rotation of the engine 1 is stopped by a coast stop or the like, the driving of the mechanical oil pump 10m is stopped and the hydraulic pressure is reduced. In preparation for this, the oil passage 50 is provided with an electric oil pump 10e.

  The electric oil pump 10e supplies electric power from the battery 13 under the control of the controller 12 in order to supply hydraulic pressure to the transmission 4 when the rotation of the engine 1 is stopped and the mechanical oil pump 10m is not operating. To generate hydraulic pressure.

  The electric oil pump 10e operates at a relatively low load such as an idle stop or a coast stop. Therefore, it is desirable to have a capacity that can satisfy the required hydraulic pressure in such an operating situation, and a capacity that does not increase the weight and cost of the vehicle.

  FIG. 5 is a flowchart of coast stop execution determination by the controller 12 of the present embodiment. Note that the processing of this flowchart is executed by the controller 12 at a predetermined interval (for example, 10 ms).

The coast stop execution determination process by the controller 12 will be described.
Signals are input from the various sensors shown in FIG. 2 to the controller 12, and when signals are input from the various sensors (step 101), the current operating state specified from the input signals is obtained. Based on this, it is determined whether or not a coast stop condition (stop condition for the engine 1) is satisfied (step 102).

Here, the coast stop condition is a condition for determining whether or not the driver intends to stop, and is the following a to c.
a: The foot is released from the accelerator pedal (accelerator opening APO = 0)
b: The brake pedal is depressed (brake hydraulic pressure is greater than or equal to a predetermined value)
c: Vehicle speed is less than coast stop permission vehicle speed VSP2

  Therefore, when it is determined in step 102 that the coast stop condition is not satisfied, the process proceeds to step 105 and the coast stop is prohibited (stop of the engine 1 is prohibited).

On the other hand, when it is determined that the coast stop condition is satisfied (step 102, Yes), the controller 12 determines whether or not the auxiliary transmission mechanism 30 is shifting (step 103).
Specifically, the controller 12 determines whether or not a shift is being performed based on the rotational speeds on the input side and the output side of the auxiliary transmission mechanism 30.

  If it is determined in step 103 that the subtransmission mechanism 30 is shifting, coast stop is prohibited (stop of the engine 1 is prohibited) in step 105. Therefore, even when the coast stop condition is satisfied, the coast stop is not executed when the gear is being changed.

  On the other hand, if it is determined in step 103 that the gear is not being shifted, coast stop is permitted (stop of the engine 1 is permitted) in step 104. Therefore, the coast stop is executed when the coast stop condition is satisfied and the auxiliary transmission mechanism 30 is not shifting.

Here, the term “during shifting” means that the engagement of the engagement-side friction element and the release of the release-side friction element are in progress in the auxiliary transmission mechanism 30, that is, the transmission ratio of the auxiliary transmission mechanism 30 actually changes. This does not mean only the case where the speed change is performed, but includes the time when the gear ratio of the subtransmission mechanism 30 is actually changing and the time before and after.
Specifically, the “preparation phase (phase in which pre-charging is applied to the friction engagement element on the engagement side for the engagement of the friction engagement element)” and “torque phase (the friction engagement element on the engagement side and the release side) "Phase for switching torque with the friction engagement element)," Inertia phase (phase for shifting the sub-transmission mechanism 30) "," Completion phase "(completely tightening the friction engagement element on the engagement side by increasing the hydraulic pressure) All the phases to be concluded) ”are included.

Hereinafter, an operation example of the transmission 4 according to the embodiment will be described by applying to the traveling state of the vehicle.
FIG. 6 is a timing chart for explaining the operation of the transmission. FIG. 6A is a case in which the subtransmission mechanism 30 considers whether or not the sub-transmission mechanism 30 is shifting when determining the start of the coast stop. (B) is a figure which respectively shows the case of the prior art example which does not consider whether it is during shifting.

[Operation Example 1]
Hereinafter, when the vehicle is traveling at a vehicle speed higher than the coast stop permission vehicle speed VSP2, the vehicle speed is decreased due to acceleration: off, brake: on, and the vehicle speed is decreased, and the coast stop permission vehicle speed. A case will be described where there is a shift command (first speed → second speed) immediately before reaching VSP2.
In the transmission 4 according to the embodiment, the coast stop permission vehicle speed VSP2 is higher than the coast stop permission vehicle speed VSP1 (see FIG. 6A) in the case of the conventional example, and the speed change is performed. It is assumed that an area that can be executed is set.

When the vehicle speed continues to decrease and becomes equal to or less than the coast stop permission vehicle speed VSP2, the coast stop conditions ac are satisfied at the time point t3 ((a) in FIG. 6: vehicle speed reference, FIG. 5: step 102, Yes).
Then, at this time t3, it is determined whether or not the subtransmission mechanism 30 is shifting (FIG. 5: step 103).
In the case of FIG. 6A, the paddle switch is operated and an upshift command is input immediately before the vehicle speed reaches the coast stop permission vehicle speed VSP2 (see FIG. 6A: paddle SW).
Therefore, in the subtransmission mechanism 30, the shift from the first speed to the second speed is started at the time t <b> 2 when the paddle switch is operated, and the hydraulic pressure (first speed clutch) for engaging the first speed friction engagement element after the time t <b> 2. Pressure) and hydraulic pressure (second speed clutch pressure) for engaging the second speed friction engagement element has started ((a) in FIG. 6: target Gr ratio, first speed clutch pressure, second speed clutch pressure, See actual Gr ratio).

Therefore, at time t3 when the vehicle speed becomes equal to or less than the coast stop permission vehicle speed VSP2, it is determined that the shift of the auxiliary transmission mechanism 30 is being executed (FIG. 5: Step 103, Yes). In the subsequent Step 105, the coast stop is performed. It is prohibited (stop of the engine 1 is prohibited).
Therefore, the coast stop is not started (executed) at the time point t3 when the coast stop condition is satisfied (see (a): coast stop in FIG. 6).

Here, the process of the flowchart of FIG. 5 is repeatedly executed at predetermined time intervals (for example, every 10 ms). Therefore, until the shift in the subtransmission mechanism 30 is completed, the determination in step 103 is affirmed and the coast stop is not started.
When the shift is completed, the determination in step 103 is denied at the time t4 and the coast stop is permitted (stop of the engine 1 is permitted), so the coast stop is started (FIG. 6). (See (a), actual Gr ratio, coast stop).

  Then, the mechanical oil pump 10m driven by the engine 1 is stopped, and the electric oil pump 10e is driven. Here, since the hydraulic pressure from the electric oil pump 10e has sufficient pressure to hold the frictional engagement element in the engaged state, the second-speed frictional engagement element is engaged even after the engine 1 is completely stopped. The state is held by the hydraulic pressure from the electric oil pump 10e (see (a) in FIG. 6: engine rotational speed Ne, electric oil pump, second speed clutch pressure).

[Operation Comparison Example 1]
Hereinafter, when the vehicle is traveling at a vehicle speed higher than the coast stop permission vehicle speed VSP2, taking as an example the case of the conventional example that does not consider whether or not the gear shift is being performed in the determination of the start of the coast stop. , Accelerator: Off, Brake: When the vehicle speed decreases due to ON, and the vehicle speed decreases and immediately before reaching the coast stop permission vehicle speed VSP2, there is a shift command (1st speed → 2nd speed). To do.
Here, in this operation comparison example 1, for comparison with the operation example 1 described above, the coast stop permission vehicle speed VSP2 is higher than the conventional coast stop permission vehicle speed VSP1 set in a vehicle speed range where no shift is performed. The description will be made on the assumption that the vehicle speed side is set to a vehicle speed range in which shifting can be performed.

If the vehicle speed continues to decrease and becomes the coast stop permission vehicle speed VSP2 or less, in the case of the conventional example, it is not considered whether or not the gear is being shifted, so the coast stop is permitted at the time t3 (FIG. 6). (B): See vehicle speed, coast stop).
Then, since the fuel injection to the engine 1 is stopped at the time t3, the engine 1 is stopped while decreasing the rotational speed after the time t3 (see (b) of FIG. 6: engine rotational speed Ne). .
As a result, the hydraulic pressure from the mechanical oil pump 10m driven by the engine 1 decreases after time t3 and finally becomes zero, so that the electric oil pump 10e is newly driven from time t3 (FIG. 6 (b): see electric oil pump).

In the case of FIG. 6B, the paddle switch is operated and an upshift command is input immediately before the vehicle speed reaches the coast stop permission vehicle speed VSP2 (see FIG. 6B: paddle SW).
Therefore, at time t2 when the paddle switch is operated, a shift from the first speed to the second speed is started, and after time t2, a decrease in hydraulic pressure (first speed clutch pressure) for engaging the first speed friction engagement element, 2 The hydraulic pressure (second speed clutch pressure) for engaging the high-speed frictional engagement element has started to rise (see (b) in FIG. 6: target Gr ratio, first speed clutch pressure, second speed clutch pressure, actual Gr ratio).

Therefore, the engine 1 stops while the second-speed frictional engagement element is being fastened, and the hydraulic pressure from the mechanical oil pump 10m is reduced.
Here, since the capacity of the electric oil pump 10e is smaller than that of the mechanical oil pump 10m, the hydraulic pressure from the electric oil pump 10e is weaker than the mechanical oil pump 10m in the force (fastening speed) for fastening the frictional engagement element. ing.
For this reason, the second speed clutch pressure rises more slowly than when the mechanical oil pump 10m is driven (see the chain line in the figure) (see the solid line in the figure). Here, the first-speed clutch pressure slowly decreases due to the hydraulic pressure from the accumulator, but since the increase speed of the second-speed clutch pressure is slower than this lowering speed, the shift from the first speed to the second speed becomes slower ( There is a possibility that the driver may feel uncomfortable in the shift behavior (see (b): second speed clutch pressure: solid line, actual Gr ratio).

  Here, when the transmission 4 does not include the electric oil pump 10e, the second speed clutch pressure is decreased and the speed is changed from the first speed to the second speed from the time t3 when the vehicle speed becomes equal to or less than the coast stop permission vehicle speed VSP2. In the middle of the operation, the vehicle returns to the first speed from the first speed through the intermediate gear ratio (see FIG. 6B: second speed clutch pressure: one-dot chain line, actual Gr ratio). In such a case, a shock may occur due to a G change resulting from the reverse direction of the change in the gear ratio, and the driver may feel uncomfortable with this G change.

Thus, in the case of the conventional example that does not consider whether or not the gear shift is being performed in the determination of the start of the coast stop, whether the transmission 4 includes the electric oil pump 10e or not, There is a possibility that the driver may feel uncomfortable due to an obstacle to the shift behavior.
On the other hand, as in the transmission 4 according to the embodiment, the sub-transmission mechanism 30 shifts even if the coast stop condition is satisfied in consideration of whether or not the shift is being performed in determining whether to start the coast stop. By avoiding the coast stop when the vehicle is in the middle, the ongoing shift is performed by the hydraulic pressure from the mechanical oil pump 10m, so that the coast stop is started in the middle of the shift. It is suitably prevented that troubles occur.

As described above, in the first embodiment,
A sub-transmission mechanism 30 (power transmission unit) of the transmission 4 that transmits the rotational driving force of the engine 1 (drive source) to the drive wheels 7 at a speed ratio determined according to the combination of the engagement state and the release state of the plurality of friction engagement elements. )When,
A mechanical oil pump 10m (hydraulic power source) driven by the engine 1,
A controller 12 (drive source control means) that stops the engine 1 when the coast stop condition is satisfied while the vehicle is decelerating,
Even if the coast stop condition is satisfied, the controller 12 stops the engine 1 when the sub-transmission mechanism 30 is performing a shift that changes the combination of the engagement state and the release state of the plurality of friction engagement elements. The configuration is such that the coast stop to be executed is not executed, and the coast stop is executed after the shift in the auxiliary transmission mechanism 30 is completed.
Here, the coast stop condition is a condition for determining whether or not the driver intends to stop, and is the following a to c.
a: The foot is released from the accelerator pedal (accelerator opening APO = 0)
b: The brake pedal is depressed (brake hydraulic pressure is greater than or equal to a predetermined value)
c: Vehicle speed is less than coast stop permission vehicle speed VSP2

With this configuration, even when the coast stop condition is satisfied, the engine 1 is not stopped when the subtransmission mechanism 30 is shifting.
Therefore, even if the engine 1 is stopped on the high vehicle speed range side where the gear shift can be performed, the hydraulic pressure supplied from the engine 1 does not decrease during the gear shift and the gear shift is not hindered.
As a result, there are problems caused by a shift problem, a problem that the change direction of the gear ratio is reversed in the middle of the shift and a shock is generated, and a problem that the shift speed is changed during the shift (the shift is extended). Since generation | occurrence | production can be prevented suitably, it can prevent a driver | operator feeling uncomfortable about a shift behavior. In addition, since the engine 1 can be stopped even on the high vehicle speed side, the opportunity to stop the engine 1 can be increased, and thereby an effect of improving fuel consumption can be expected.

Here, the coast stop permission vehicle speed VSP2 is a coast stop permission vehicle speed (a turbine rotation speed Nt that can be taken with respect to the vehicle speed is 1) in a conventional transmission configured to determine whether or not to perform a coast stop based only on the vehicle speed. The vehicle is set in a vehicle speed range in which a shift on the higher vehicle speed side can be performed than the coast stop permission vehicle speed VSP1 (see FIG. 6) set in a low vehicle speed range where only one gear is not shifted.
As a result, the engine 1 is stopped by the coast stop on the vehicle speed range side where the shift can be performed. However, when the shift is being performed, the engine 1 is stopped by the coast stop until the shift is completed. Is not executed, the occurrence of the problem due to the above-described trouble of shifting is preferably prevented. Furthermore, since the opportunity to stop the engine 1 can be increased, the effect of improving fuel consumption can be expected.

Furthermore, an electric oil pump 10e (other hydraulic source) driven by the battery 13 when the engine 1 is stopped is further provided,
Shifting in the auxiliary transmission mechanism 30 changes one of the first friction engagement element (Low brake 32) and the second friction engagement element (High clutch 33) of the auxiliary transmission mechanism 30 from the engaged state to the released state, It is executed by changing the other from the released state to the fastened state,
The speed change while the engine 1 is stopped is configured to be executed by the hydraulic pressure from the electric oil pump 10e instead of the hydraulic pressure from the mechanical oil pump 10m.

When coast stop for stopping the engine 1 during the shift is executed, the shift is performed by the hydraulic pressure from the electric oil pump 10e instead of the hydraulic pressure from the mechanical oil pump 10m driven by the engine 1.
Then, in the friction engagement element that changes from the engagement state to the release state, only the hydraulic pressure that has been in the engagement state is drained. In the frictional engagement element that changes to the engaged state, the change to the engaged state is completed with a delay due to switching to the electric oil pump 10e.

With the configuration as described above, the coast stop is not executed when the sub-transmission mechanism 30 is shifting, so that the shift that is performed when the coast stop condition is satisfied causes the friction engagement element to The fastening force (fastening speed) is not hydraulic pressure from the electric oil pump 10e, which is weaker than the mechanical oil pump 10m, but hydraulic pressure from the mechanical oil pump 10m. As a result, the frictional engagement element that changes to the engaged state due to the shift is brought into the engaged state without delay, so that the problem that the shift speed changes during the shift can be prevented and the driver can change the shift behavior. It is possible to prevent the user from feeling uncomfortable.
Furthermore, since the frictional engagement element that changes to the engaged state due to the shift does not become a released state in the middle of the shift, there is a problem that the change direction of the gear ratio reverses in the middle of the shift and a shock occurs. Can be prevented. Therefore, this also prevents the driver from feeling uncomfortable with the shift behavior.

Further, since the hydraulic pressure from the electric oil pump 10e has sufficient pressure to hold the frictional engagement element in the engaged state, the engagement state of the frictional engagement element is maintained after the engine 1 is completely stopped by the coast stop. Is held by the hydraulic pressure from the electric oil pump 10e.
Therefore, even if the driver requests acceleration when the engine 1 is stopped, when the engine 1 is subsequently driven, the upstream side (engine 1 side) in the transmission 4 (the drive wheels 7). Side), the driving force can be quickly transmitted, so that the responsiveness to the acceleration request can be suppressed from decreasing.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 7 is a flowchart of coast stop execution determination by the controller 12 according to the second embodiment. Note that the processing of this flowchart is also executed by the controller 12 at a predetermined interval (for example, 10 ms).

The coast stop execution determination process by the controller 12 will be described.
Signals are input from the various sensors shown in FIG. 2 to the controller 12, and when signals are input from the various sensors (step 201), the current operating state specified from the input signals is obtained. Based on this, it is determined whether or not a coast stop condition (stop condition for the engine 1) is satisfied (step 202).

Here, the coast stop permission condition is a condition for determining whether or not the driver intends to stop, and is the following a to c.
a: The foot is released from the accelerator pedal (accelerator opening APO = 0)
b: The brake pedal is depressed (brake hydraulic pressure is greater than or equal to a predetermined value)
c: Vehicle speed is less than coast stop permission vehicle speed VSP2

  Therefore, if it is determined in step 202 that the coast stop condition is not satisfied, the process proceeds to step 206, where the coast stop is prohibited (stop of the engine 1 is prohibited).

On the other hand, when it is determined that the coast stop condition is satisfied (step 202, Yes), the controller 12 determines whether or not the auxiliary transmission mechanism 30 is shifting (step 203).
Specifically, the controller 12 determines whether or not a shift is being performed based on the rotational speeds on the input side and the output side of the auxiliary transmission mechanism 30.

  If it is determined in step 203 that the subtransmission mechanism 30 is not shifting, the process proceeds to step 205, where coast stop is permitted (stop of the engine 1 is permitted). Therefore, in such a case, a coast stop is executed.

On the other hand, if it is determined in step 203 that a shift is being performed, it is determined in step 204 whether or not the shift is due to a switching operation from the travel range of the shift lever to the non-travel range.
This determination is made based on the output signal of the inhibitor switch 45 (see FIG. 2) that detects the shift lever selection range.

  If it is determined in step 204 that the shift is due to a shift operation from the travel range of the shift lever to the non-travel range, the process proceeds to step 205 where coast stop is permitted (stop of engine 1 is permitted). Is done. Therefore, in such a case, a coast stop is executed.

When the selected range of the shift lever is switched from the travel range to the non-travel range, all the frictional engagement elements are released and the engagement of the frictional engagement elements is not executed.
In such a case, the change ratio of the gear ratio at the time of shifting is only one direction, and even if coast stop is executed, the changing direction does not reverse during the shifting, so that a shock or the like is generated and the driver feels uncomfortable. No worries.
Therefore, in this case, even if the subtransmission mechanism 30 is shifting, allowing the coast stop (permitting the stop of the engine 1) can earn time for stopping the engine 1. Improvement can be expected.

On the other hand, if it is determined in step 204 that the shift is not due to a shift operation from the travel range of the shift lever to the non-travel range, the process proceeds to step 206 and coast stop is prohibited (stop of engine 1 is prohibited). )
In such a case, if coast stop is permitted, the mechanical oil pump 10m stops during the engagement of the frictional engagement element, and the engagement of the frictional engagement element is delayed, so the driver feels uncomfortable with the behavior of the transmission. Because there is a risk of having.

Hereinafter, an example of the operation of the transmission 4 according to the second embodiment will be described by applying to the traveling state of the vehicle.
FIG. 8 is a timing chart for explaining the operation of the transmission, in which (a) is a case of an embodiment in which the operation direction of the shift lever is taken into account in determining the start of the coast stop, and (b) It is a figure which shows the case of the prior art example which does not consider the operation direction of a shift lever, respectively.

[Operation example 2]
Hereinafter, when the vehicle is traveling at a vehicle speed higher than the coast stop permitting vehicle speed VSP2, the vehicle speed is decreased due to acceleration: off, brake: on, and the vehicle speed decreases, and the coast stop permitting vehicle speed VSP2 The case where there is a shift command (N position → D position) by operating the shift lever immediately before reaching will be described.
In the transmission 4 according to the embodiment, the coast stop permission vehicle speed VSP2 is higher than the conventional coast stop permission vehicle speed VSP1 (see FIG. 8A), and the shift is executed. It is assumed that the area is set to be able to be performed.

When the vehicle speed continues to decrease and becomes equal to or less than the coast stop permission vehicle speed VSP2, the coast stop conditions ac are satisfied at the time t3 (FIG. 8 (a): vehicle speed reference, FIG. 7: step 202, Yes).
Then, at this time t3, it is determined whether or not the subtransmission mechanism 30 is shifting (FIG. 7: Step 203).
In the case of FIG. 8A, the shift lever is operated to switch from the N position (non-traveling range) to the D position (traveling range) immediately before the vehicle speed reaches the coast stop permission vehicle speed VSP2. Therefore, the shift is started at time t2 when the shift lever is operated, and at time t3, the shift is started from the released state to the engaged state of the friction engagement element (Low brake 32) that is engaged at the start. (Refer to (a) in FIG. 8: vehicle speed, lever position, clutch pressure).

  Therefore, at the time t3 when the vehicle speed becomes equal to or less than the coast stop permission vehicle speed VSP2, it is determined that the subtransmission mechanism 30 is shifting (FIG. 7: Yes at step 203), and in the subsequent step 204, the shift is shifted. It is determined whether or not it is due to switching from the travel range of the lever to the non-travel range (FIG. 7: step 204).

In the case of FIG. 8A, the shift lever is operated to switch from the N position (non-traveling range) to the D position (traveling range) immediately before the vehicle speed reaches the coast stop permission vehicle speed VSP2.
Therefore, the determination in step 204 is negative, and coast stop is prohibited (stop of engine 1 is prohibited) at time t3 (see FIG. 8: coast stop, FIG. 7). : Step 204, Step 206).

Here, the processing of the flowchart of FIG. 7 is repeatedly executed at predetermined time intervals. Therefore, the coast stop is not permitted until the shift is completed (FIG. 7: Steps 203, 204, and 206).
When the clutch pressure supplied to the engagement-side frictional engagement element (Low brake 32 or High clutch 33) reaches the target pressure and the shift is completed, the determination of step 203 is denied at the time t4, and the coast The stop is permitted (stop of the engine 1 is permitted) (see (a) of FIG. 8: clutch pressure, coast stop, electric oil pump, FIG. 7: step 205).

As a result, the mechanical oil pump 10m driven by the engine 1 is stopped and the electric oil pump 10e is driven (see (a) of FIG. 8: electric oil pump).
Since the hydraulic pressure from the electric oil pump 10e has sufficient pressure to hold the frictional engagement element in the engaged state, the engagement state of the frictional engagement element in the travel range after time t4 is the electric oil pump 10e. (See (a): clutch pressure in FIG. 8).

  Here, when the operation direction of the shift lever is opposite to the above-described operation example 2, that is, the shift command by the operation of the shift lever is from the travel range (D position) to the non-travel range (N position). The case will be described.

  FIG. 9 is a timing chart for explaining the operation of the transmission, in which the operation direction of the shift lever is taken into consideration in the determination of the start of the coast stop, and the operation direction of the shift lever is as shown in FIG. It is a figure which shows the case where it is reverse (travel range (D position)-> non-travel range (N position)).

[Operation Example 3]
Hereinafter, when the vehicle is traveling at a vehicle speed higher than the coast stop permission vehicle speed VSP2, the vehicle speed decreases due to accelerator: off, brake: on, the vehicle speed decreases, and the coast stop start condition The case where there is a shift command (D position → N position) by operating the shift lever immediately before reaching the vehicle speed will be described.
In the transmission 4 according to the embodiment, the coast stop permission vehicle speed VSP2 is set to a region where the coast stop permission vehicle speed VSP1 is higher than the conventional coast stop permission vehicle speed VSP1 and can be shifted. And

When the vehicle speed continues to decrease and becomes equal to or less than the coast stop permission vehicle speed VSP2, the coast stop condition is satisfied at the time t3 (FIG. 9: Refer to vehicle speed, FIG. 7: Step 202, Yes).
Then, at this time t3, it is determined whether or not the subtransmission mechanism 30 is shifting (FIG. 7: Step 203).
In the case of FIG. 9, immediately before the vehicle speed reaches the coast stop permission vehicle speed VSP2, the shift lever is operated to switch from the D position (traveling range) to the N position (non-traveling range). Therefore, at the time t2 when the shift lever is operated, a change (shift) of the friction engagement element (for example, the High clutch 33) that has been in the engaged state is started (shift), and at time t3, the auxiliary transmission mechanism 30 is turned on. It means that shifting is in progress.

  Therefore, at time t3 when the vehicle speed becomes equal to or lower than the coast stop permission vehicle speed VSP2, it is determined that the subtransmission mechanism 30 is shifting (FIG. 7: Yes at step 203). It is determined whether or not it is due to switching from the travel range of the lever to the non-travel range (FIG. 7: step 204).

  In the case of FIG. 9, immediately before the vehicle speed reaches the coast stop permission vehicle speed VSP2, the shift lever is operated to switch from the D position (travel range) to the N position (non-travel range). Will be affirmed. As a result, coast stop is permitted (stop of engine 1 is permitted) at time t3 (FIG. 7: step 204, step 205).

Here, when the selection range of the shift lever is switched from the travel range to the non-travel range, all the friction engagement elements are released, and the engagement of the friction engagement elements is not executed.
In such a case, the direction of change of the gear ratio is only one direction, and even if coast stop is executed, the direction of change does not reverse in the middle of the gear shift, so there is no fear of causing a sense of incongruity to the driver due to a shock or the like.

  Therefore, it is possible to earn time for stopping the engine 1 by allowing the engine 1 to be stopped when the shift lever is being shifted from the traveling range to the non-driving range. , Fuel economy can be further improved.

[Operation Comparison Example 2]
Hereinafter, taking the case of the conventional example not considering whether or not the gear shift is being performed in the determination of the start of the coast stop as an example, when the vehicle is traveling at a vehicle speed higher than the coast stop permission vehicle speed VSP2, the accelerator is : Off, Brake: When the vehicle speed decreases due to ON, and there is a shift command (N position → D position) by operating the shift lever immediately before the vehicle speed decreases and reaches the coast stop permission vehicle speed VSP2. Will be described for comparison with the second operation example.
Here, in this operation comparative example 2, for comparison with the above-described operation example 1, the coast stop permission vehicle speed VSP2 is a vehicle speed range in which shifting can be performed unlike the case of Patent Document 1, The description will be made on the assumption that the vehicle speed is set to a higher vehicle speed side than the coast stop permission vehicle speed VSP1 set in the vehicle speed range where no speed change is performed.

When the vehicle speed continues to decrease and becomes equal to or less than the coast stop permission vehicle speed VSP2, it is determined that the coast stop is permitted at the time t3 (see FIG. 8B: vehicle speed, coast stop). Become.
When it is determined that the coast stop is started, the fuel injection to the engine 1 is stopped at the time point t3, so that the engine 1 is stopped while decreasing the rotational speed after the time t3 '((( b): See engine speed Ne).
As a result, the hydraulic pressure from the mechanical oil pump 10m driven by the engine 1 decreases after time t3 and finally becomes zero, so that the electric oil pump 10e is newly driven from time t3 (FIG. 8 (b): see electric oil pump).

In the case of FIG. 8B, immediately before the vehicle speed reaches the coast stop permission vehicle speed VSP2, the shift lever is operated to switch from the N position (non-traveling range) to the D position (traveling range) ( FIG. 8B: Refer to lever position.
Therefore, from the time point t2 when the shift lever is operated, an increase in the hydraulic pressure supplied to the frictional engagement element that is engaged at the D position is started (see FIG. 8B: clutch pressure).

Therefore, in the middle of fastening the frictional engagement element, the engine 1 stops and the hydraulic pressure from the mechanical oil pump 10m decreases.
Here, since the electric oil pump 10e has a smaller capacity than the mechanical oil pump 10m, the hydraulic pressure from the electric oil pump 10e has a sufficient pressure to hold the frictional engagement element in the engaged state, but the frictional engagement element The fastening force (fastening speed) is weaker than that of the mechanical oil pump 10m.
For this reason, the clutch pressure rises more slowly than in the case of the mechanical oil pump 10m (see the chain line in the figure) (see the solid line in the figure), so that the fastening speed of the frictional engagement element becomes slow. For this reason, the engagement of the frictional engagement element is delayed, and the driver may feel uncomfortable with the shift behavior (see FIG. 8B: clutch pressure).

As described above, in the case of the conventional example that does not consider whether or not the gear shift is being performed in the determination of the start of the coast stop, the gear shift behavior is hindered, and the driver may feel uncomfortable.
On the other hand, as in the case of the transmission 4 according to the embodiment, when the coast stop is determined even when the coast stop condition is satisfied, the start of the coast stop is determined in consideration of whether the shift is in progress. By preventing the coast stop from being performed, it is possible to suitably prevent the shift from being hindered.
Furthermore, even if a coast stop is executed during a shift, it is determined whether or not there is no problem with the shift according to the operating direction of the shift lever, and if there is no problem, the coast stop is performed. Thus, since it is possible to earn time for stopping the engine 1, an improvement in fuel consumption can be expected.

As described above, in the second embodiment,
The controller 12 (drive source control means) establishes the coast stop condition when the sub-transmission mechanism 30 (power transmission unit) of the transmission 4 is performing a shift to change the disengaged friction engagement element to the engagement state. Even so, the engine 1 is not stopped by the coast stop.

  When the coast stop is executed while the shift that changes the released frictional engagement element to the engagement state is being executed, the hydraulic pressure decreases while changing the released frictional engagement element to the engagement state, There is a possibility that the driver may feel uncomfortable due to the reverse of the change direction of the transmission ratio of the auxiliary transmission mechanism 30 and the change of the change speed of the transmission ratio. By configuring as described above, it is possible to suitably prevent a coast stop from being executed in the middle of a shift that changes the disengaged friction engagement element to the engagement state, so that the driver feels uncomfortable with the shift behavior, etc. Can be prevented. In addition, since the engine 1 can be stopped even on the high vehicle speed side, the opportunity to stop the engine 1 can be increased, and thereby an effect of improving fuel consumption can be expected.

  The controller 12 (drive source control means) indicates that the shift state of the sub-transmission mechanism 30 (power transmission unit) of the transmission 4 is changed, and the shift lever selection range is changed from the travel range (D position) to the non-travel range (N position). If it is caused by switching, a coast stop for stopping the engine 1 is executed. If it is caused by switching from the non-traveling range (N position) to the traveling range (D position), the coast stop is performed. It was set as the structure which does not execute.

When the selection range of the shift lever is switched from the travel range (D position) to the non-travel range (N position), all the friction engagement elements are released and the engagement of the friction engagement elements is not executed. Become. In such a case, the direction of change of the gear ratio is only one direction, and even if coast stop is executed, the direction of change does not reverse in the middle of the gear change, so there is no fear of causing a sense of incongruity to the driver due to a shock or the like.
Therefore, the engine 1 is stopped by adopting a configuration in which the coast stop is executed when the shift lever is in the middle of shifting due to the selection range of the shift lever being switched from the travel range (D position) to the non-travel range (N position). Since you can earn time, you can expect improved fuel economy.
In addition, when the gear shift is in progress due to the shift lever selected range being switched from the non-travel range (N position) to the travel range (D position), the coast stop is not executed, so that the engine is shifted during the shift. The hydraulic pressure supplied from 1 does not decrease, causing a problem in shifting.
As a result, it is possible to suitably prevent the occurrence of a problem caused by a shift problem and a problem that a shock occurs due to the reverse direction of the gear ratio changing in the middle of the shift, so that the driver feels strange about the shift behavior. Can be prevented. In addition, since the engine 1 can be stopped even on the high vehicle speed side, the opportunity to stop the engine 1 can be increased, and thereby an effect of improving fuel consumption can be expected.

In the above-described embodiment, it is first checked whether or not the coast stop condition is satisfied. When the coast stop condition is satisfied, it is determined whether or not the auxiliary transmission mechanism 30 of the transmission 4 is shifting. The case where coast stop execution determination (permission / prohibition) is performed, that is, the case where coast stop execution determination is performed through two stages of determination is described as an example.
However, the coast stop execution determination may be performed with only one step determination.

Hereinafter, a process in the controller 12 in the case where the coast stop execution determination (permission / prohibition) is performed in one step will be described.
FIG. 10 is a flowchart of a modified example of coast stop execution determination. Note that the processing of this flowchart is also executed by the controller 12 at a predetermined interval (for example, 10 ms).

  Signals are input from the various sensors shown in FIG. 2 to the controller 12, and when signals are input from the various sensors (step 301), the current operating state specified from the input signals is obtained. Based on this, it is determined whether or not a coast stop condition (stop condition for the engine 1) is satisfied (step 302).

The coast stop permission conditions in this case are the following a to d.
a: The foot is released from the accelerator pedal (accelerator opening APO = 0)
b: The brake pedal is depressed (brake hydraulic pressure is greater than or equal to a predetermined value)
c: Vehicle speed is coast stop permission vehicle speed VSP2 or less d: Sub-transmission mechanism 30 is not shifting (not in the middle of changing the combination of the engagement state and the release state of the friction engagement element)

  Here, a to c are conditions for determining whether or not the driver intends to stop, and d is a condition for determining whether or not shifting is being performed. The processing in the controller 12 according to this modified example is different from the above-described embodiment in that the presence / absence of the driver's intention to stop and whether or not the shift is in progress are collectively determined. .

  Therefore, if it is determined in step 302 that the coast stop condition is not satisfied, the process proceeds to step 304 and the coast stop is prohibited (stop of the engine 1 is prohibited).

  On the other hand, when it is determined that the coast stop condition is satisfied (step 302, Yes), the process proceeds to step 303, where the coast stop is permitted (stop of the engine 1 is permitted). Therefore, in such a case, a coast stop is executed.

As described above, in the coast stop execution determination according to the modification,
A sub-transmission mechanism 30 of the transmission 4 that transmits the driving force of the engine 1 to the drive wheels at a gear ratio determined according to the combination of the engagement state and the release state of the plurality of friction engagement elements;
A mechanical oil pump 10m driven by the engine 1,
The engine 1 is stopped when a predetermined coast stop condition is satisfied while the vehicle is decelerating and the auxiliary transmission mechanism 30 is not shifting (not in the middle of changing the combination of the engagement state and the release state of the friction engagement element). And an automatic transmission for a vehicle having a configuration including the controller 12.
Here, the coast stop conditions are the following a to d.
a: The foot is released from the accelerator pedal (accelerator opening APO = 0)
b: The brake pedal is depressed (brake hydraulic pressure is greater than or equal to a predetermined value)
c: Vehicle speed is coast stop permission vehicle speed VSP2 or less d: Sub-transmission mechanism 30 is not shifting (not in the middle of changing the combination of the engagement state and the release state of the friction engagement element)

With this configuration, even if the engine 1 is stopped on the high vehicle speed range side where the shift can be performed, the coast stop is not executed in the middle of the shift. The supplied hydraulic pressure is not lowered and the shift is not hindered.
As a result, it is possible to suitably prevent the occurrence of a problem caused by a shift problem and a problem that a shock occurs due to the reverse direction of the gear ratio changing in the middle of the shift, so that the driver feels strange about the shift behavior. Can be prevented. In addition, since the engine 1 can be stopped even on the high vehicle speed side, the opportunity to stop the engine 1 can be increased, and thereby an effect of improving fuel consumption can be expected.

  In the above-described embodiment, (1) the case where the shift lever is operated (engine brake request or the like) immediately before reaching the coast stop permission vehicle speed for judging the start of the coast stop is given as an example. As described above, the present invention relates to (2) the case where the vehicle deceleration increases and the coast stop permission vehicle speed is reached during the shift based on the downshift line, or (3) the vehicle is The present invention can also be suitably applied when the accelerator is turned off and the brake is turned on during acceleration.

  In the above-described embodiment, the present invention has been described by taking as an example the case where the present invention is applied to a belt-type continuously variable transmission in which the auxiliary transmission mechanism 30 is provided on the downstream side of the variator 20. The present invention is also applicable to a belt-type continuously variable transmission provided with a sub-transmission mechanism 30 and an automatic transmission that achieves a desired shift speed by combining a plurality of fastening elements.

Here, the “shift” targeted by the present invention is a shift in the sub-transmission mechanism 30, that is, a shift in a transmission mechanism including a frictional engagement element that changes from the released state to the engaged state, and does not include the shift in the variator 20. It is.
In the transmission 4 in which the auxiliary transmission mechanism 30 and the variator 20 are arranged in series as in the present embodiment, the auxiliary transmission mechanism is to prevent damage due to slippage between the pulleys 21 and 22 and the V-belt 23. The hydraulic pressure is supplied in preference to the variator 20 from 30. Therefore, when the mechanical oil pump 10m is stopped by the coast stop and the hydraulic pressure is reduced together with the engine rotational speed, the hydraulic pressure from the mechanical oil pump 10m during the engine rotational speed reduction is preferentially supplied to the variator 20, and the coast stop When the electric oil pump 10e is driven, the hydraulic pressure generated by the electric oil pump 10e is also preferentially supplied to the variator 20, and the auxiliary transmission mechanism 30 is not supplied with sufficient hydraulic pressure.

  For example, when the electric oil pump 10e that is driven while the engine is stopped is not provided, the change direction of the speed ratio is reversed in the middle of the shift, and the G change occurs, so the driver feels uncomfortable. It will cause a shock. Further, when the electric oil pump 10e is provided, the speed change rate of the auxiliary transmission mechanism 30 is slowed in the middle, resulting in a change in the speed change rate that may cause the driver to feel uncomfortable. End up.

On the other hand, since the variator 20 is preferentially supplied with the hydraulic pressure of the mechanical oil pump 10m and the electric oil pump 10e, the change in the gear ratio occurring during the gear shift is more than the change in the gear ratio in the sub-transmission mechanism 30. It is small and does not result in a change in gear ratio that may cause the driver to feel uncomfortable. Therefore, the speed change in the variator 20 is not subject to the “speed change” that is the subject of the present invention.
Further, in the present embodiment, the transmission 4 in which the auxiliary transmission mechanism 30 and the variator 20 are arranged in series has been described. However, the present invention is not limited to this, and can be applied to a stepped transmission mechanism that does not include the variator 20. It is. That is, the frictional engagement element in the stepped transmission mechanism is disposed so as not to be immersed in the oil surface in order to prevent dragging by oil in a released state where power is not transmitted. Therefore, when the mechanical oil pump 10m is stopped by the coast stop, the oil in the frictional engagement element is likely to drop due to gravity, and a sufficient oil pressure cannot be secured. As a result, a change in the gear ratio that may cause the driver to feel uncomfortable. On the other hand, in a continuously variable transmission mechanism that does not include the auxiliary transmission mechanism 30, since the variator 20 is generally immersed in the oil surface, even if the mechanical oil pump 10m is stopped by a coast stop, the oil in the variator 20 is reduced. Therefore, it is possible to suppress the occurrence of a shift shock that makes the driver feel uncomfortable.

  Furthermore, in the above-described embodiment, the case where the “drive source” is the engine is exemplified, but the present invention is not limited to this, and for example, torque is input from the motor or from both the engine and the motor. It may be configured.

As described above, conventionally, the coast stop permission vehicle speed VSP1 has been set to a vehicle speed range in which shifting is not performed (for example, less than 5 to 6 km / h). In response to recent fuel efficiency requirements, when attempting to increase the coast stop permitting vehicle speed to a higher vehicle speed range (for example, less than 15 to 20 km / h), the higher vehicle speed range than the coast stop permitting vehicle speed VSP1 is It is the vehicle speed range in which a shift can be performed, and the present invention has solved that by finding that a shift is hindered if the engine 1 is stopped by a coast stop in the middle of a shift.
Here, the high vehicle speed region side where the coast stop permission vehicle speed VSP2 is set is a vehicle speed region higher than the second gear → first gear downshift line in a transmission having two or more gear stages.

In the above-described embodiment, the case of upshift / downshift by the operation of the paddle switch is illustrated, but the present invention can also be applied to the case of upshift / downshift by the operation of the shift lever.
Examples of such a case include a downshift operation with an emblem request, an upshift operation without an emblem, a non-travel range operation from a travel range, a travel range operation from a non-travel range, and the like.

Furthermore, in the first operation example described above, the case where there is a request for an upshift when the shift stage of the auxiliary transmission mechanism 30 is the first speed (when an upshift command is input from the paddle switch) is taken as an example. Explained. This is an operation for requesting an upshift to be performed when the driver feels that the engine brake is highly effective during deceleration.
The present invention is not limited to such a case. For example, even when the driver requests an operation for downshifting performed when the driver feels that the effectiveness of the engine brake is weak at the time of deceleration traveling. Applicable.

Further, in the above-described embodiment, the case where the electric oil pump 10e (other hydraulic power source) is driven while the engine 1 is stopped by the coast stop has been described as an example. The present invention can also be applied to an automatic transmission that does not include the pump 10e.
In such a case, when the vehicle speed becomes equal to or less than the coast stop permission vehicle speed VSP2 during the shift based on the operation of the shift lever from the N position (non-travel range) to the D position (travel range), the disengaged state is engaged by the gear shift. After the frictional engagement element is in the engaged state, the hydraulic pressure that holds the frictional engagement element in the engaged state is lowered, and the change in the change direction of the transmission ratio is generated. In the case of an automatic transmission that determines whether or not to perform a coast stop based only on the vehicle speed, the frictional engagement element that is to be engaged immediately after the shift lever is switched to the D position (traveling range). The supplied hydraulic pressure decreases, and the change direction of the gear ratio changes.

  In any case, a change in the change ratio of the gear ratio occurs and a shock due to the G change occurs, but the coast stop according to the present invention is released after the shift lever is switched to the D position (travel range). The speed ratio changes after a lapse of time until the frictional engagement element in the state is in the engaged state. Since the vehicle speed is also reduced until the engaged state, the vehicle speed is sufficiently reduced compared to the conventional case when the friction engagement element is engaged, and the shock is sufficiently small. It will be a thing. Therefore, even if the change direction of the gear ratio changes in a state where the vehicle speed is sufficiently lowered, it is possible to suppress the uncomfortable feeling given to the driver as compared with the case of the conventional transmission.

Claims (4)

A power transmission unit that transmits the rotational driving force of the drive source to the drive wheels at a gear ratio determined according to the combination of the engagement state and the release state of the plurality of friction engagement elements;
A hydraulic source driven by the drive source;
Drive source control means for stopping the drive source when a predetermined stop condition is satisfied while the vehicle is decelerating, and
Even when the stop condition is satisfied, the drive source control means does not stop the drive source when the power transmission unit is shifting .
The drive source control means is configured to switch the drive source when the shift ratio of the power transmission unit is changed because the shift lever selection range is switched from a travel range to a non-travel range. Stop running
The automatic transmission for a vehicle , wherein the driving source is not stopped when the non-traveling range is switched to the traveling range .   2. The drive source control unit according to claim 1, wherein the drive source control unit does not stop the drive source when the power transmission unit is performing a shift to change the disengaged frictional engagement element to the engagement state. Automatic transmission for vehicles. The speed change in the power transmission unit changes one of the first friction engagement elements and the second friction engagement elements of the plurality of friction engagement elements from the engagement state to the release state, and changes the other from the release state to the engagement state. It is executed by letting
While stopping the driving source in place of the hydraulic pressure from the driving power source, the hydraulic pressure from the other driving sources, the first friction engagement element, characterized in that it is supplied to the second frictional engagement element An automatic transmission for a vehicle according to claim 1 or 2. A power transmission unit that transmits the rotational driving force of the drive source to the drive wheels at a gear ratio determined according to the combination of the engagement state and the release state of the plurality of friction engagement elements;
A hydraulic source driven by the drive source;
Drive source control means for stopping the drive source when a predetermined stop condition is satisfied while the vehicle is decelerating and the power transmission unit is not shifting .
The drive source control means is configured to switch the drive source when the shift ratio of the power transmission unit is changed because the shift lever selection range is switched from a travel range to a non-travel range. Stop running
The automatic transmission for a vehicle , wherein the driving source is not stopped when the non-traveling range is switched to the traveling range .

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