JP6667385B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a control device for a vehicle that performs neutral running control.

  2. Description of the Related Art Neutral traveling control in which an automatic transmission travels in a neutral state (power cutoff state) is known. According to this control, when the vehicle is coasting, by setting the transmission in the neutral state, the power transmission between the engine and the drive wheels is interrupted and the engine brake (load of the drive source) does not act. Fuel economy can be improved by suppressing the decrease (for example, see Patent Document 1).

  This neutral traveling control includes (A) that the forward range is selected, (B) that the vehicle speed is equal to or higher than the set vehicle speed (medium to high vehicle speed), (C) that the accelerator is off, (D) that the brake is applied. Is off when a control condition including each condition of “off” is satisfied.

  Further, the neutral running control can be divided into a sailing stop control in which the engine is stopped and the vehicle runs in the neutral state, and a sailing control in which the engine is stopped and the vehicle runs in the neutral state.

  Patent Document 1 (Paragraph 0024) discloses that all the fastening elements of the automatic transmission are released during the sailing stop control.

JP 2013-213557 A

  Incidentally, in order to improve the fuel efficiency by the neutral traveling control, it is effective to further suppress the decrease in the traveling speed and extend the coasting traveling distance as much as possible.

  The present invention was devised from such a viewpoint, and provides a vehicle control device capable of improving the fuel efficiency of a vehicle by further extending the coasting distance by the neutral driving control. The purpose is to:

  (1) In order to achieve the above object, a first vehicle control device of the present invention provides a vehicle including a stepped transmission having an input rotary member including an input shaft and an output rotary member including an output shaft. The control device according to claim 1, wherein when performing neutral traveling control that puts the power between the input rotating member and the output rotating member in a power cutoff state while the vehicle is traveling, the output related to the output shaft decreases as the vehicle speed decreases. The neutral pattern is changed so that the shaft torque is increased.

  (2) A second vehicle control device according to the present invention is a vehicle control device including a stepped transmission having an input rotary member including an input shaft and an output rotary member including an output shaft. When performing neutral traveling control in which the power between the input rotating member and the output rotating member is cut off during traveling of the vehicle, the neutral is controlled such that the inertia applied to the output shaft increases as the vehicle speed decreases. The feature is to change the pattern.

  (3) A plurality of intermediate rotation members provided between the input rotation member and the output rotation member, and a power transmission state between the output rotation member and the plurality of intermediate rotation members during the neutral traveling control. It is preferable to select a neutral pattern as follows.

  (4) There is a friction engagement element that changes the neutral pattern by changing the combination of the engagement of the plurality of friction engagement elements of the stepped transmission according to the vehicle speed, and continues the engagement state before and after this change. It is preferable to select the neutral pattern as described above.

  (5) When changing the neutral pattern according to the vehicle speed, it is preferable to select the neutral pattern so that there is a frictional engagement element that continues the engagement state in the entire vehicle speed range.

(6) It is preferable that in accordance with the vehicle speed range (out of the selectable the neutral pattern) based on the neutral pattern the output shaft torque is largest make changes of the neutral pattern.
(7) It is preferable to change the neutral pattern based on the neutral pattern in which the inertia applied to the output shaft becomes the largest (of the neutral patterns that can be selected) according to the vehicle speed range.
( 8 ) In these cases, a part of the neutral pattern in which the output shaft torque or the inertia applied to the output shaft becomes the largest (of the neutral patterns that can be selected) according to the vehicle speed range is thinned, and the remaining neutral patterns are removed. It is preferable to change the neutral pattern based on the following.

  The stepped transmission includes an input shaft, an output shaft, a first planetary gear mechanism having a first element, a second element, and a third element in the order of arrangement on the alignment chart, and an arrangement on the alignment chart. A second planetary gear mechanism having a fourth element, a fifth element, and a sixth element in this order, and a third planetary gear mechanism having a seventh element, an eighth element, and a ninth element in the order of alignment on the alignment chart. A fourth planetary gear mechanism having tenth, eleventh, and twelfth elements in the order of arrangement on the diagram, and first to sixth frictional fastening elements, wherein the input shaft, the first element, A first rotating member composed of the eleventh element and one member of the first frictional coupling element, and a first rotational member composed of the output shaft, the eighth element, and one member of the second frictional coupling element A second rotating member and one of the sixth element, the seventh element, the tenth element, and the third friction fastening element A third rotating member including a member, a fourth rotating member including the third element and the fifth element, and a fourth rotating member including one of the fourth element and the fourth frictional engagement element. A fifth rotating member, a sixth rotating member composed of one of the ninth element and the fifth friction coupling element, and a sixth rotational member composed of the other member of the twelfth element and the second friction coupling element. Eighth rotation composed of a seven rotation member, the second element, the other member of the first frictional engagement element, the other member of the third frictional engagement element, and one member of the sixth frictional engagement element And the other member of the fourth frictional engagement element, the other member of the fifth frictional engagement element, and the other member of the sixth frictional engagement element are also preferably fixed.

  According to the present invention, the inertia of the intermediate rotary member is added to the inertia of the output rotary member, and the inertia acting on the output shaft is efficiently increased. Therefore, the output shaft torque (including the inertial force applied to the output shaft) is increased, and the inertia is increased. The mileage can be extended.

1 is an overall system configuration diagram showing a power train including a stepped transmission of a vehicle and a control system thereof according to an embodiment of the present invention. FIG. 1 is a skeleton diagram illustrating a configuration of a stepped transmission according to an embodiment of the present invention. 3 is a table of engagement of each friction engagement element for each shift speed of the stepped transmission according to one embodiment of the present invention. 4 is a fastening table of each friction engagement element showing a neutral pattern of the stepped transmission according to one embodiment of the present invention. 6 is a graph showing the inertia torque and the limit rotation speed of the rotating element in each neutral pattern of the stepped transmission according to the embodiment of the present invention, in correspondence with the output rotation. 4 is a graph illustrating a friction coefficient between clutches regarding the inertia torque calculation. FIG. 4 is a skeleton diagram showing a fastening state of a friction engagement element in a neutral pattern of the stepped transmission according to the embodiment of the present invention. FIGS. 7A to 7C are diagrams illustrating selection examples according to the output shaft rotation speed of the neutral pattern of the stepped transmission according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely examples, and there is no intention to exclude various modifications and application of technology not explicitly described in the following embodiments. Each configuration of the following embodiments can be variously modified and implemented without departing from the spirit thereof, and can be selectively used as needed, or can be appropriately combined.

[1. Overall system configuration]
As shown in FIG. 1, the power train of the vehicle according to the present embodiment is an automatic transmission (stepped transmission) 4 including an engine 1, a torque converter 2 with a lock-up clutch, and a stepped automatic transmission mechanism 3. And a power transmission mechanism 5 including a differential mechanism 5 a provided between the output shaft of the automatic transmission 4 and the drive wheels 6.

  The automatic transmission mechanism 3 is connected to the engine 1 via a torque converter 2 having a lock-up clutch (not shown), includes various friction engagement elements (clutch or brake), and fastens these friction engagement elements. Alternatively, each shift speed is achieved by releasing.

  The engagement or release of various friction engagement elements and the engagement state of the lock-up clutch of the torque converter 2 are controlled by controlling a required solenoid valve provided in a control valve unit (CV unit) 7 to switch the oil supply state. By doing.

  Further, an oil pump (not shown) that generates hydraulic oil supplied to the CV unit 7 is driven by an electric motor (not shown) in preparation for operating the friction engagement element while the engine 1 is stopped. It is configured to be possible.

  An automatic transmission controller (transmission control means) 10 is provided to control the CV unit 7, and an engine controller 100 is provided to control the engine 1. The automatic transmission controller 10 controls the CV unit 7 based on information from various sensors 11 to 14. The automatic transmission controller 10 and the engine controller 100 are connected so that information can be transmitted to each other, and can control the automatic transmission mechanism 3 and the engine 1 in cooperation with each other.

[2. Configuration of automatic transmission]
As shown in FIG. 2, the automatic transmission mechanism 3 includes a first planetary gear mechanism (PG1) 31, a second planetary gear mechanism (PG2) 32, a third planetary gear mechanism (PG3) 33, and a fourth planetary gear mechanism (PG4) 34. Two planetary gear mechanisms (planetary gear mechanisms) are coaxially arranged in series. Each of the planetary gear mechanisms 31 to 34 includes sun gears 31S to 34S, carriers 31C to 34C, and ring gears 31R to 34R.

  Further, a first clutch (first frictional engagement element) K81, a second clutch (second frictional engagement element) K27, and a third clutch (third frictional engagement element) K38 for connecting and disconnecting or fixing the elements of each planetary gear mechanism. , The first brake (fourth friction engagement element) B05, the second brake (fifth friction engagement element) B06, and the third brake (sixth friction engagement element) B08. It has three brakes B05, B06 and B08. By selectively intermittently fixing or fixing these friction engagement elements (clutch or brake), the first to ninth speeds of nine forward speeds and nine reverse speeds are achieved.

That is, the first planetary gear mechanism 31 includes the sun gear (first element) 31S, the carrier (second element) 31C, and the ring gear (third element) 31R.
The second planetary gear mechanism 32 includes a sun gear (fourth element) 32S, a carrier (fifth element) 32C, and a ring gear (sixth element) 32R.
The third planetary gear mechanism 33 includes a sun gear (seventh element) 33S, a carrier (eighth element) 33C, and a ring gear (ninth element) 33R.
The fourth planetary gear mechanism 34 includes a sun gear (tenth element) 34S, a carrier (eleventh element) 34C, and a ring gear (twelfth element) 34R.

  The automatic transmission mechanism 3 includes an input shaft 30 </ b> A to which rotation is input from the engine 1 via the torque converter 2, an output shaft 30 </ b> B for outputting rotation to driving wheels via the power transmission mechanism 5, and planetary gear mechanisms 31 to 34. Intermediate shafts 30C and 30D connecting specific elements are provided. By selectively combining required elements of each of the planetary gear mechanisms 31 to 34, a required power transmission path is formed and a corresponding shift speed is achieved.

  That is, the sun gear 31S of the first planetary gear mechanism 31 and the carrier 34C of the fourth planetary gear mechanism 34 are directly coupled to the input shaft 30A of the automatic transmission mechanism 3. Therefore, the sun gear 31S of the first planetary gear mechanism 31 and the carrier 34C of the fourth planetary gear mechanism 34 always rotate integrally with the input shaft 30A. The carrier 31C of the first planetary gear mechanism 31 is connected to the input shaft 30A of the automatic transmission mechanism 3 via a first clutch K81.

  The carrier 33C of the third planetary gear mechanism 33 is directly coupled to the output shaft 30B of the automatic transmission mechanism 3. Therefore, the carrier 33C of the third planetary gear mechanism 33 always rotates integrally with the output shaft 30B. Further, a ring gear 34R of a fourth planetary gear mechanism 34 is connected to an output shaft 30B of the automatic transmission mechanism 3 via a second clutch K27.

  The ring gear 31R of the first planetary gear mechanism 31 and the carrier 32C of the second planetary gear mechanism 32 are both directly connected to the intermediate shaft 30C. Therefore, the ring gear 31R of the first planetary gear mechanism 31 and the carrier 32C of the second planetary gear mechanism 32 always rotate integrally.

  The ring gear 32R of the second planetary gear mechanism 32, the sun gear 33S of the third planetary gear mechanism 33, and the sun gear 34S of the fourth planetary gear mechanism 34 are all directly connected to the intermediate shaft 30D. Therefore, the ring gear 32R of the first planetary gear mechanism 31, the sun gear 33S of the third planetary gear mechanism 33, and the sun gear 34S of the fourth planetary gear mechanism 34 always rotate integrally.

  The carrier 31C of the first planetary gear mechanism 31 is connected to the intermediate shaft 30D via the third clutch K38. Further, the carrier 31C of the first planetary gear mechanism 31 is connected to the transmission case 3A via the third brake B08. The sun gear 32S of the second planetary gear mechanism 32 is connected to the transmission case 3A via the first brake B05, and the ring gear 33R of the third planetary gear mechanism 33 is connected to the transmission case 3A via the second brake B06.

  In the automatic transmission mechanism 3 configured as described above, the engagement of each friction engagement element such as the second clutch K27, the first clutch K81, the third clutch K38, the first brake B05, the second brake B06, and the third brake B08. By the combination of any of the first to ninth speeds, any one of the nine forward speeds and the reverse speed is achieved.

  FIG. 3 is an engagement table showing the engagement state of each friction engagement element for each shift speed in the automatic transmission mechanism 3. In FIG. 3, the mark “○” indicates that the friction engagement element is in the engaged state, and the blank indicates that the friction engagement element is in the released state. The step numbers 1 to 9 indicate the first to ninth forward speeds, and the step number Rev indicates the reverse step. Note that each shift speed is also referred to as “n-th speed” or simply “n-speed”.

  As shown in FIG. 3, to achieve the first speed, the first brake B05, the second brake B06, and the third clutch K38 are engaged, and the other friction engagement elements are released. To achieve the second speed, the second brake B06, the first clutch K81, and the third clutch K38 are engaged, and the other friction engagement elements are released. To achieve the third speed, the first brake B05, the second brake B06, and the first clutch K81 are engaged, and the other friction engagement elements are released.

  To achieve the fourth speed, the first brake B05, the second brake B06, and the second clutch K27 are engaged, and the other friction engagement elements are released. To achieve the fifth speed, the first brake B05, the first clutch K81, and the second clutch K27 are engaged, and the other friction engagement elements are released. To achieve the sixth speed, the first clutch K81, the second clutch K27, and the third clutch K38 are engaged, and the other friction engagement elements are released.

  To achieve the seventh speed, the first brake B05, the second clutch K27, and the third clutch K38 are engaged, and the other friction engagement elements are released. To achieve the eighth speed, the third brake B08, the second clutch K27, and the third clutch K38 are engaged, and the other friction engagement elements are released. To achieve the ninth speed, the first brake B05, the third brake B08, and the second clutch K27 are engaged, and the other friction engagement elements are released. To achieve the reverse gear, the first brake B05, the second brake B06, and the third brake B08 are engaged, and the other friction engagement elements are released.

[3. Control of automatic transmission]
The shift control by engagement and disengagement of each friction engagement element of the automatic transmission mechanism 3 is performed by the automatic transmission controller 10 according to the state of the vehicle (the selection range of the automatic transmission, the vehicle speed VSP, and the state of the accelerator opening APO). This is performed based on a shift diagram (shift map) (not shown). As shown in FIG. 1, information from an inhibitor switch 11, a vehicle speed sensor 12, an accelerator opening sensor 13, a brake switch 14, and the like are input to the automatic transmission controller 10.

The automatic transmission controller 10 includes a neutral traveling control unit (control unit) 10B in addition to a shift control unit (shift control unit) 10A that performs the above-described shift control.
The neutral traveling control unit 10B determines whether a predetermined condition is satisfied based on information from the sensors 11 to 14 during traveling of the vehicle, and when the predetermined condition is satisfied, sets the automatic transmission 4 to the neutral state and coasts. Neutral running control (also referred to as inertial running control).

[3.1. Neutral traveling control]
This neutral traveling control is intended to improve fuel efficiency during coasting when the vehicle is running at medium to high speeds, such as on a highway, and the neutral traveling control includes the following conditions as conditions relating to the traveling state of the vehicle. (A) to (D) are set.
(A) The forward range is selected (B) The vehicle speed is equal to or higher than the set vehicle speed (medium to high vehicle speed) (C) The accelerator is off (D) The brake is off,

Conditions (A) and (B) are conditions related to the vehicle being in a medium-high speed running state.
Conditions (C) and (D) are conditions regarding that the vehicle is in the coasting state.

  These conditions (A) to (D) are AND conditions. If the state in which all of the conditions (A) to (D) are satisfied continues for a predetermined time (for example, 2 seconds), the execution condition of the neutral traveling control is satisfied. .

  In this neutral traveling control, normally, the automatic transmission 4 is set to the neutral state and the drive source is stopped. Here, the fuel injection of the engine 1 is stopped, the engine 1 is stopped, and the automatic transmission 4 is set in the neutral state (this is also referred to as sailing stop control).

  By setting the automatic transmission mechanism 3 in the neutral state, for example, so-called engine braking does not occur even when the engine 1 is operating, so that the deceleration of the vehicle is suppressed, the coasting distance is extended, and the effect of improving fuel efficiency can be obtained. At this time, by stopping the drive source such as the engine 1, a further effect of improving fuel efficiency can be obtained.

  However, when the driving source of the vehicle is used for purposes other than the traveling of the vehicle, in the neutral traveling control, only the control for setting the automatic transmission 4 to the neutral state without stopping the driving source is performed (this (Also referred to as sailing control).

  As described above, in the neutral traveling control, the automatic transmission mechanism 3 of the automatic transmission 4 is set to the neutral state. However, in the present control device, not only the automatic transmission mechanism 3 is set to the neutral state, but also the inertia of the automatic transmission mechanism 3 is changed. Utilizing this method, it is possible to extend the traveling distance by suppressing the speed drop during coasting.

  That is, when the automatic transmission mechanism 3 is set in the neutral state, it can be realized even if some of the friction engagement elements of the automatic transmission mechanism 3 are kept engaged without releasing all the friction engagement elements. .

  During coasting, as the inertia of the rotating system that rotates integrally with the output shaft 30B increases, the decrease in the speed of the vehicle can be suppressed, and the traveling distance of the vehicle can be extended.

  In the case of the present embodiment, as described above, the first clutch (first friction engagement element) K81, the second clutch (second friction engagement element) K27, the third clutch (third friction engagement element) K38, A first brake (fourth friction engagement element) B05, a second brake (fifth friction engagement element) B06, and a third brake (sixth friction engagement element) B08 are provided. Each gear is achieved by engaging three of the friction engagement elements and releasing the rest.

  As shown in FIG. 2, when all of the friction engagement elements are released, the automatic transmission mechanism 3 rotates the input rotation member (first rotation member) M1, the output rotation member (second rotation member) M2, and the first rotation member M2. An intermediate rotation member (third rotation member) M3, a second intermediate rotation member (fourth rotation member) M4, a third intermediate rotation member (fifth rotation member) M5, and a fourth intermediate rotation member (sixth rotation member) ) M6, a fifth intermediate rotating member (seventh rotating member) M7, and a sixth intermediate rotating member (eighth rotating member) M8. Note that the rotating member refers to a group including one or more rotating elements that are always rotated by the same rotation.

Among them, the input rotary member (first rotary member) M1 is composed of the input shaft 30A, the sun gear 31S, the carrier 34C, and one element of the first clutch K81 (each element of the frictional engagement element is mutually engaged. , Members).
The output rotation member (second rotation member) M2 includes an output shaft 30B, a carrier 33C, and one element of the second clutch K27.

The first intermediate rotating member (third rotating member) M3 includes an intermediate shaft 30D, a ring gear 32R, a sun gear 33S, a sun gear 34S, and one element of a third clutch K38.
The second intermediate rotation member (fourth rotation member) M4 includes an intermediate shaft 30C, a ring gear 31R, and a carrier 32C.

The third intermediate rotation member (fourth rotation member) M5 includes a sun gear 32S and one element (rotation side element) of the first brake B05.
The fourth intermediate rotation member (eighth rotation member) M6 includes a ring gear 33R and one element (rotation side element) of the second brake B06.

The fifth intermediate rotation member (seventh rotation member) M7 is configured to include the ring gear 34R and the other element of the second clutch K27.
The sixth intermediate rotation member (eighth rotation member) M8 includes a carrier 31C, the other element of the first clutch K81, the other element of the third clutch K38, and one element of the third brake B08 (rotation side element). ).

  The other element of the first brake B05, the other element of the second brake B06, and the other element of the third brake B08 are all fixed elements fixed to the transmission case 3A.

  When all the frictional engagement elements of the automatic transmission mechanism 3 are released, the output rotary member M2 rotates independently of the other rotary members, so that only the inertia of the output rotary member M2 suppresses a decrease in traveling speed. To contribute.

  If the power transmission between the input rotary member M1 and the output rotary member M2 is cut off and the automatic transmission mechanism 3 is set in the neutral state, and at least one of the intermediate rotary members M3 to M8 is set in the power transmitting state with the output rotary member M2, the output is The inertia of the intermediate rotary member, which is in a power transmission state with the rotary member M2, also contributes to the suppression of the decrease in the traveling speed, and the reduction in the vehicle speed can be further suppressed.

  Therefore, when performing the neutral traveling control, the neutral traveling control unit 10B selects a neutral pattern (neutral engagement pattern) in which the output rotation member M2 and at least one of the intermediate rotation members M3 to M8 are in the power transmission state.

[3.1.1. Neutral pattern]
As shown in patterns 1 to 13 shown in FIG. 4, only two of the six friction engagement elements are fastened and the remaining are released, so that the automatic transmission mechanism 3 is in the neutral state and is integrated with the output shaft 30B. A neutral pattern that can increase the inertia of the rotating rotating system is achieved.

  As described above, the neutral pattern that can set the transmission mechanism in the neutral state and can increase the inertia of the rotating system that rotates integrally with the output shaft 30B depends on the configuration (skeleton) of the transmission mechanism from the alignment chart of the planetary gear mechanism. Can be identified.

  That is, it is possible to determine whether or not the output shaft rotation speed (output shaft rotation speed) Nout is uniquely determined with respect to the input shaft rotation speed by using the alignment chart. It can be determined whether the vehicle is neutral.

In the case of the configuration (skeleton) of the automatic transmission mechanism 3 according to the present embodiment, the pattern in which only two of the six friction engagement elements are fastened and the rest are released is ( ₆ C ₂ = 15 patterns). Since there are two patterns in the interlock state among the 15 patterns, as shown in FIG. 4, the automatic transmission mechanism 3 becomes neutral in 13 patterns 1 to 13.

  From the viewpoint of more effectively using the inertia of the rotating elements of the automatic transmission mechanism 3, it is effective to fasten only two of the six friction engagement elements and release the remaining friction engagement elements. It is also possible to effectively use the inertia of the rotating element of the automatic transmission mechanism 3 by fastening only one of the engaging elements and releasing the other.

  As shown in FIG. 4, pattern 1 is a pattern in which only the first clutch K81 and the first brake B05 are engaged, and pattern 2 is a pattern in which only the first clutch K81 and the third clutch K38 are engaged. Pattern 3 is a pattern in which only the first clutch K81 and the second clutch K27 are engaged, and Pattern 4 is a pattern in which only the first clutch K81 and the second brake B06 are engaged.

  Pattern 5 is a pattern in which only the first brake B05 and the third brake B08 are engaged, pattern 6 is a pattern in which only the first brake B05 and the third clutch K38 are engaged, and pattern 7 is a pattern in which the first brake B05 is engaged. And the second clutch K27 only. The pattern 8 is a pattern where only the first brake B05 and the second brake B06 are engaged.

  Pattern 9 is a pattern in which only the third brake B08 and the third clutch K38 are engaged, pattern 10 is a pattern in which only the third brake B08 and the second clutch K27 are engaged, and pattern 11 is a pattern in which the third brake B08 is engaged. And only the second brake B06 is engaged.

  The pattern 12 is a pattern in which only the third clutch K38 and the second clutch K27 are engaged, and the pattern 13 is a pattern in which only the third clutch K38 and the second brake B06 are engaged.

  These patterns 1 to 13 each have a different rotation member that rotates integrally with the output shaft 30 </ b> B, and therefore have a different inertia size. Therefore, the magnitude of the inertia in each of the patterns 1 to 13 with respect to the vehicle speed will be examined.

  FIG. 5 is a graph showing the output shaft torque (torque of the output shaft 30B) Tout in each neutral pattern (patterns 1 to 13) in association with the output rotation speed No proportional to the vehicle speed Vsp. The derivation of this graph will be described. Note that the output shaft torque Tout depends on the inertia.

  For each of the neutral patterns of patterns 1 to 13, the rotation speed ω of each of the rotation members M1 to M8 for each vehicle speed Vsp (output rotation speed No) is derived from the relationship of the alignment chart of each planetary gear mechanism.

For example, the pattern 1 in the case of the skeleton shown in FIG. 2 of the present embodiment is as shown in Table 1 below. This is also created for patterns 2 to 13.

  A differential rotation Δω of each frictional engagement element at a predetermined neutral pattern and a predetermined vehicle speed is derived based on the rotation speed ω of each of the rotation members M1 to M8.

Furthermore, based on the differential rotation [Delta] [omega, derives the drag torque T _cl for each frictional engagement element during the release of a predetermined neutral pattern and a predetermined vehicle speed.

Here, the derivation of the drag torque _Tcl will be described.
Drag torque T _cl of the respective frictional engagement elements, as shown in FIG. 6, dependent on the rotational speed difference Δω between the disks.

In other words, in the region where the differential rotation speed Δω is small, the drag torque _Tcl according to the friction coefficient μ _oil of oil alone is obtained, and when the differential rotation speed Δω is large, the drag coefficient T _oil and drag torque T _cl, and the rotational speed difference Δω becomes further larger the torque T _cl drag corresponding to the friction coefficient mu _air only air.

Here, in view of the drag torque T _cl, the make a motion equation of each rotary member M1~M8 by equation balancing torque (inertia × angular acceleration = output shaft torque Tout), the general formula the following formula ( As shown in a), the individual expressions of the rotating members M1 to M8 are as shown in the following expressions (a1) to (a8).

Here, I _Mi is the inertia of each of the rotating members M1 to M8, ω _Mi ′ is the angular acceleration of each of the rotating members M1 to _M8 , _{ΔT MiE} is the sum of the rotating torque of each of the rotating elements of each of the rotating members M1 to M8, and ΔT _D is total loss due to the drag torque T _cl of the friction engagement element during the release, oT _etc are other torque running resistance or the like of the input torque and the vehicle to the transmission mechanism. Further, the sign of +-indicates that the torque applied to the output shaft 30B is +, and the torque in the reverse direction is-. However, if +-is reversed, there is no problem because only the value of-is calculated as the calculation result.

  The equation (a1) relates to the first rotating member M1, the equation (a2) relates to the second rotating member M2, the equation (a3) relates to the third rotating member M3, the equation (a4) relates to the fourth rotating member M4, and the equation ( a5) relates to the fifth rotating member M5, equation (a6) relates to the sixth rotating member M6, equation (a7) relates to the seventh rotating member M7, and equation (a8) relates to the eighth rotating member M8.

  In the equations (a1) to (a8), Tk81 indicates the torque of the first clutch K81, Tk27 indicates the torque of the second clutch K27, and Tk38 indicates the torque of the third clutch K38. Tb05 indicates the torque of the first brake B05, Tb06 indicates the torque of the second brake B06, and Tb08 indicates the torque of the third brake B08. Tt indicates the input torque to the transmission mechanism, and Ts indicates the running resistance of the vehicle.

T1 is the torque of the ring gear 31R of the first planetary gear mechanism (PG1) 31, T2 is the torque of the ring gear 32R of the second planetary gear mechanism (PG2) 32, and T3 is the torque of the ring gear 33R of the third planetary gear mechanism (PG3) 33. T4 indicates the torque, and T4 indicates the torque of the ring gear 34R of the fourth planetary gear mechanism (PG4) 34.
A1 to a4 and b1 to b4 by which T1 to T4 are multiplied are coefficients given as design values.

また、上式（ｂ）を時間微分すると次式（ｃ）となる。

The following equation (b) is obtained from the alignment chart of each planetary gear mechanism.

The following equation (c) is obtained by differentiating the above equation (b) with time.

  Here, when the above equation (c) is established in the first planetary gear mechanism (PG1) 31, the following equation (c1) is obtained. When the above equation (c) is established in the second planetary gear mechanism (PG2) 32, the following equation is obtained. When the above equation (c) is established in the third planetary gear mechanism (PG3) 33, the following equation (c3) is obtained. When the above equation (c) is established in the fourth planetary gear mechanism (PG4) 34, The following equation (c4) is obtained.

In equations (c1) to (c4), ω _M1 ′ is the angular acceleration of the first rotating member M1, ω _M2 ′ is the angular acceleration of the second rotating member M2, and ω _M3 ′ is the angular acceleration of the third rotating member M3. _M4 'is the angular acceleration of the fourth rotating member M4,? _M5 ' is the angular acceleration of the fifth rotating member M5,? _M6 'is the angular acceleration of the sixth rotating member M6, and? _M7 ' is the seventh. _M8 'indicates the angular acceleration of the rotating member M7, and _ωM8 ' indicates the angular acceleration of the eighth rotating member M8.

By solving the above equations (a1) to (a8) and (c1) to (c4), it is possible to calculate the output shaft torque Tout at a predetermined neutral pattern and a predetermined vehicle speed Vsp.
As described above, the output shaft torque Tout for each vehicle speed Vsp can be calculated in each neutral pattern, so that the graph shown in FIG. 5 can be created.

Furthermore, since the allowable rotation speed (the maximum rotation speed at which rotation is allowed) of each of the rotation members M1 to M8 can be determined from the design values, either computationally or experimentally, the angular speed ω exceeds the allowable rotation speed. The present vehicle speed (output rotation speed) No is not plotted on the graph.
This makes it possible to derive a graph of the output shaft torque Tout in consideration of the allowable limit rotational speed.

[3.1.2. Neutral pattern selection]
As shown in FIG. 5, for example, the pattern 13 has a large output shaft torque Tout, but has an output rotational speed (L1 to L6 in FIG. 5, hereinafter also referred to as an allowable limit rotational speed) which is an allowable rotational speed. Is low as shown by L2 in FIG. If the allowable limit rotational speed Nolim is low, overspeed occurs unless the vehicle speed is low, so that it cannot be adopted as a neutral pattern.

  On the other hand, in pattern 8, for example, the output shaft torque Tout is not so large, but the allowable limit rotational speed Nolim is high. Therefore, the pattern 8 can use the inertia of the rotating member for maintaining the vehicle speed without causing overspeed even in a high vehicle speed region.

  However, FIG. 5 shows up to a normal high-speed region in which the vehicle speed Vsp is lower than the predetermined vehicle speed, and omits the super-high-speed region in which the vehicle speed Vsp is higher than the predetermined vehicle speed. In an ultra-high speed region where the vehicle speed Vsp is equal to or higher than a predetermined vehicle speed, the pattern 8 causes excessive rotation. On the other hand, for example, the output shaft torque Tout of the pattern 7 is lower than that of the pattern 8, but the allowable limit rotational speed Nolim is higher than that of the pattern 8, so that overspeed does not occur even in the ultra-high speed range.

  Further, for example, the allowable limit rotational speed Nolim of the pattern 12 is lower than that of the pattern 8 as indicated by L5 in FIG. 5, but the output shaft torque Tout is slightly larger. For example, in pattern 4, the allowable limit rotational speed Nolim is lower than that in pattern 12, as indicated by L3 in FIG. 5, but the output shaft torque Tout is larger. Further, in the above-described pattern 13, the allowable limit rotational speed Nolim is lower as shown by L2 in FIG. 5, but the output shaft torque Tout is larger than in the pattern 4.

  Therefore, in the present embodiment, when the vehicle speed Vsp is lower than the predetermined vehicle speed, the neutral pattern is changed according to the vehicle speed such that the output shaft torque Tout increases as the vehicle speed decreases. Since the output shaft torque Tout depends on the inertia of the intermediate members M3 to M8 applied to the output shaft, the neutral pattern may be changed according to the vehicle speed so that the inertia applied to the output shaft increases as the vehicle speed decreases. I can say.

  In the case of the stepped transmission 4 of the present embodiment, when the vehicle speed Vsp is lower than the predetermined vehicle speed, as shown in FIG. 5, in the vehicle speed region where the output shaft rotation speed Nout corresponds to L5 or more, the pattern 8 is the most output shaft. In the vehicle speed range where the torque Tout is large and the output shaft speed Nout corresponds to L3 to L5, the pattern 12 is the largest in the vehicle speed range where the output shaft torque Tout is the largest and the output shaft speed Nout corresponds to L2 to 13. In the vehicle speed range where the output shaft torque Tout is the largest and the output shaft rotation speed Nout is equal to or less than L2, the pattern 13 has the largest output shaft torque Tout.

  Therefore, when selecting a neutral pattern in which the output shaft torque Tout is the largest in each vehicle speed range, as shown in FIG. 8A, a pattern 8 is selected in a vehicle speed range in which the output shaft rotation speed Nout is equal to or greater than L5. The pattern 12 is selected in the vehicle speed range where the rotation speed Nout is L3 to L5, the pattern 4 is selected in the vehicle speed range where the output shaft rotation speed Nout is L2 to 13 and the pattern 13 is selected in the vehicle speed range where the output shaft rotation speed Nout is L2 or less. Select

  However, when changing the neutral pattern, it is necessary to change any of the friction engagement elements, and this change causes a loss in the output shaft torque Tout. From this point, it is preferable to change the neutral pattern in consideration of the torque loss due to the change of the neutral pattern.

  In addition, when changing the neutral pattern, if a plurality of (here, two sets) frictional engagement elements are exchanged, it takes time to exchange the frictional engagement elements, so that torque loss increases. Therefore, when changing the neutral pattern, it is advantageous to change the pattern to increase the number of friction engagement elements for holding the engagement and to decrease the number of friction engagement elements for performing the change.

  Therefore, it is preferable to select the neutral pattern so that there is a frictional engagement element that continues the engagement state before and after the change of the neutral pattern. Also, when changing the neutral pattern, it is also preferable to select the neutral pattern so that there is a frictional engagement element that maintains the engagement state in all vehicle speed ranges.

  For example, when changing the neutral pattern from the pattern 8 to the pattern 12, in the pattern 8, the first brake B05 and the second brake B06 are engaged, but in the pattern 12, the third clutch K38 and the second clutch K27 are engaged. Therefore, two sets of friction engagement elements need to be replaced, and the torque loss due to the change in the neutral pattern is large.

  When changing the neutral pattern from the pattern 12 to the pattern 4, the third clutch K38 and the second clutch K27 are engaged in the pattern 12, but in the pattern 4, the first clutch K81 and the second brake B06 are engaged. Therefore, two sets of friction engagement elements need to be replaced, and the torque loss due to the change in the neutral pattern is large.

  On the other hand, when changing the neutral pattern from pattern 8 to pattern 4, in pattern 8, the first brake B05 and the second brake B06 are engaged, and in pattern 4, the first clutch K81 and the second brake B06 are engaged. Therefore, the second brake B06 is held in the engaged state, and one set of frictional engagement elements can be replaced, and the torque loss due to the change in the neutral pattern is small.

  When changing the neutral pattern from the pattern 8 to the pattern 13, the first brake B05 and the second brake B06 are engaged in the pattern 8, and the third clutch K38 and the second brake B06 are engaged in the pattern 13. Therefore, the second brake B06 is held in the engaged state, and one set of frictional engagement elements can be replaced, and the torque loss due to the change in the neutral pattern is small.

  When changing the neutral pattern from the pattern 4 to the pattern 13, the first clutch K81 and the second brake B06 are engaged in the pattern 4, and the third clutch K38 and the second brake B06 are engaged in the pattern 13. Therefore, the second brake B06 is held in the engaged state, and one set of frictional engagement elements can be replaced, and the torque loss due to the change in the neutral pattern is small.

  For example, when changing the neutral pattern from the pattern 8 to the pattern 12, the pattern 12 has a large output shaft torque Tout with respect to the pattern 8, but the increment is very small. Accordingly, the loss of the output shaft torque Tout due to the change from the pattern 8 to the pattern 12 (the two sets of friction engagement elements need to be replaced) and the increase in the output shaft torque Tout obtained by the change from the pattern 8 to the pattern 12 It is expected that the torque loss will be greater than the torque increment when comparing.

  The output shaft torque Tout of the pattern 4 is slightly larger than that of the pattern 12. For this reason, the loss of the output shaft torque Tout accompanying the change from the pattern 12 to the pattern 4 (the two sets of friction engagement elements need to be replaced) and the output shaft torque Tout obtained by changing the pattern 12 to the pattern 4 It is also expected that the torque loss will be greater than the torque increment when compared to

  On the other hand, the output shaft torque Tout of the pattern 4 is slightly larger than that of the pattern 8. The loss of the output shaft torque Tout due to the change from the pattern 8 to the pattern 4 (only one set of friction engagement elements needs to be replaced), the increase in the output shaft torque Tout obtained by the change from the pattern 12 to the pattern 4 In comparison, it is expected that a case where the torque increase is larger than the torque loss and a case where the torque loss is larger than the torque increase.

  The output shaft torque Tout of the pattern 13 is extremely large for both the pattern 8 and the pattern 4. The loss of the output shaft torque Tout due to the change from the pattern 8 to the pattern 4 (only one set of friction engagement elements needs to be replaced), the increase in the output shaft torque Tout obtained by the change from the pattern 12 to the pattern 4 It is expected that the torque increment will be greater than the torque loss.

  As described above, when the torque loss due to the change in the neutral pattern exceeds the torque increase due to the increase in the output shaft torque Tout, the neutral pattern in which the output shaft torque Tout is maximized is not changed, and the neutral pattern until that time is maintained. By doing so, a decrease in the speed of the vehicle during coasting can be suppressed.

  Therefore, the torque loss due to the change in the neutral pattern is compared with the torque increment. If the torque increase exceeds the torque loss, the neutral pattern is changed.If the torque increase does not exceed the torque loss, the neutral pattern is changed. The neutral pattern is maintained without changing the pattern.

  For example, when changing from pattern 8 to pattern 12, the torque increase exceeds the torque loss, when changing from pattern 12 to pattern 4, the torque increase exceeds the torque loss, and when changing from pattern 4 to pattern 13, the torque increase. Is larger than the torque loss, as shown in FIG. 8A, the neutral pattern is changed from the pattern 8 to the pattern 12, the pattern 4, and the pattern 13 in accordance with the decrease in the output shaft rotation speed Nout.

  In this case, in any vehicle speed range, the neutral pattern is changed so as to adopt the neutral pattern in which the output shaft torque Tout is largest in the vehicle speed range.

  For example, when the pattern 8 is changed to the pattern 12, the torque increment does not exceed the torque loss, but when the pattern 8 is changed to the pattern 4, the torque increment exceeds the torque loss, and the pattern 4 changes to the pattern 13. If the torque increase exceeds the torque loss even after the change, as shown in FIG. 8B, the pattern 12 is not adopted, and the patterns 8 to 4 and 4 are changed according to the decrease in the output shaft rotation speed Nout. Change the neutral pattern to 13.

  For example, when the pattern 8 is changed to the pattern 12, the torque increment does not exceed the torque loss, and when the pattern 8 is changed to the pattern 4, the torque increment does not exceed the torque loss, and the pattern 8 changes to the pattern 13. If the torque increase is greater than the torque loss, the pattern 12 and the pattern 4 are not adopted and the pattern 8 is changed from the pattern 8 according to the decrease of the output shaft rotation speed Nout, as shown in FIG. Change the neutral pattern to 13.

  In the case of the change patterns shown in FIGS. 8B and 8C, a part (pattern 12, or patterns 12, 4) of the neutral pattern in which the output shaft torque becomes the largest according to the vehicle speed range is thinned, and the remaining patterns are thinned out. The neutral pattern is changed based on the neutral pattern (patterns 8, 4, 13 or 8, 13).

  In the case of the change patterns shown in FIGS. 8B and 8C, the second brake B06 exists as a frictional engagement element that continues the engagement state before and after the change of the neutral pattern. In addition, the second brake B06 that continues this engagement state continues the engagement state in all vehicle speed ranges.

  As described above, in the present embodiment, as the neutral pattern, the high speed is reduced centering on the pattern 8 that does not cause overspeed even in the high vehicle speed range, and the inertia of the intermediate rotating members M3 to M8 is changed by changing the neutral pattern. In order to make more effective use of the torque caused by the neutral pattern, the neutral pattern is changed. As a result, the inertia of the intermediate rotating members M3 to M8 can be used while considering the influence of energy loss that occurs when the neutral pattern is changed.

  Each of the patterns 8, 12, 4, and 13 is a pattern in which a plurality of intermediate rotating members are rotated together with the output rotating member M2. Such a pattern increases the output shaft torque, and thus inertia is used by using inertia. It is effective in extending the mileage.

  In particular, in the case of the pattern 8, since the first brake B05 and the second brake B06 are engaged, the third intermediate rotary member (which has a relatively large mass) together with the output rotary member (second rotary member) M2. Since a plurality of rotating members of the third rotating member) M3 and the fourth intermediate rotating member (fourth rotating member) M4 follow, the inertia of the rotating members M3 and M4 contribute to maintaining the vehicle speed, and a relatively high output. The shaft torque Tout is obtained.

  On the other hand, when the vehicle speed Vsp is equal to or higher than the predetermined vehicle speed, a pattern in which the allowable limit rotational speed Nolim becomes higher is selected as a neutral pattern according to the vehicle speed. That is, when the vehicle speed Vsp becomes equal to or higher than the predetermined vehicle speed, a pattern having a high allowable rotation speed is selected even if the output shaft torque Tout becomes low. When the vehicle speed Vsp further increases, a pattern having a higher allowable limit rotation speed is selected even if the output shaft torque Tout decreases.

[4. Action and effect]
According to the control device for a vehicle according to the present embodiment, the neutral traveling control unit 10B performs the neutral traveling control in which the power between the input rotary member M1 and the output rotary member M2 is cut off during the travel of the vehicle. In addition, since the neutral pattern in which the output rotation member M2 and at least one of the intermediate rotation members M3 to M8 are in the power transmission state is selected, the inertia of the intermediate rotation member is added to the inertia of the output rotation member M2 and acts on the output shaft 30B. Since the inertia increases, the output shaft torque (inertia force applied to the output shaft 30B) Tout increases, and the coasting distance can be extended, thereby contributing to improved fuel efficiency.

  Further, in the present embodiment, the neutral pattern is set according to the vehicle speed Vsp such that the output shaft torque Tout increases as the vehicle speed Vsp decreases, in other words, the inertia applied to the output shaft increases as the vehicle speed Vsp decreases. Because of this change, the output shaft torque Tout can be increased while efficiently using the inertia of the intermediate members M3 to M8 to prevent the transmission from over-rotating and protect the transmission, thereby extending the coasting distance. be able to.

  In particular, a pattern in which a plurality of intermediate rotating members are caused to rotate together with the output rotating member M2, such as patterns 8, 12, 4, and 13, is effective in increasing the output shaft torque Tout, and the coasting distance is easily extended. . That is, by increasing the number of rotating members that rotate together with the output rotating member M2, the inertia applied to the output shaft 30B can be increased, and the coasting distance can be further increased.

  In consideration of the torque loss due to the change of the neutral pattern, the torque loss is compared with the increment of the output shaft torque Tout obtained by the change of the neutral pattern, and when the torque increment is larger than the torque loss, Since the pattern is changed, the output shaft torque Tout can be increased comprehensively, and the coasting distance can be extended.

  When considering this torque loss, taking into account the point that torque loss increases when multiple friction engagement elements are replaced, the neutral pattern is set so that there is a friction engagement element that continues the engagement state before and after the change of the neutral pattern. And when the neutral pattern is changed, by selecting the neutral pattern so that there is a frictional engagement element that continues the engagement state in all vehicle speed ranges, it is possible to surely increase the output shaft torque Tout. Yes, the coasting distance can be extended.

Also, as in the present embodiment, the output shaft torque Tout, a torque loss not only inertia or (loss due drag torque T _cl (friction loss)), running resistance, also calculated in consideration such mechanical loss, based on the By adopting the neutral pattern, a combination that can maximize the coasting distance can be selected, and the coasting distance can be further extended.

  In the case of the skeleton of the automatic transmission according to the present embodiment, as shown in FIG. 7, when the second brake B06 is engaged, the third rotating member M3 becomes an output rotating member (second rotating member) as shown by a thick line. The inertia of the third rotating member M3 that rotates integrally with M2 and has relatively large inertia can be used, which is effective. For this reason, it is more effective to fasten the second brake B06 and further fasten other frictional engagement elements to effectively use the inertia of the rotating member as in patterns 8, 4, and 13, for example.

[5. Others]
Although the embodiment has been described above, the embodiment is an example of an embodiment of the present invention. For example, the skeleton of the stepped automatic transmission is not limited to that shown in FIG.

Further, in the above embodiment, as the neutral pattern, a pattern in which only two of the plurality of frictional engagement elements are fastened and the remainder is released is adopted, and the number of rotating members that rotate together with the output rotating member M2 is increased. However, for example, a pattern in which only one of the plurality of frictional engagement elements is fastened and the rest is released may be adopted. Depending on the skeleton of the automatic transmission, the pattern of the plurality of frictional engagement elements may be used. The number to be fastened may be other than one or two.
Further, for example, the plurality of neutral patterns changed according to the vehicle speed may include a pattern that releases all of the plurality of friction engagement elements.

DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 3 Stepped automatic transmission mechanism 4 Automatic transmission (stepped transmission)
Reference Signs List 5 power transmission mechanism 5a differential mechanism 6 drive wheel 7 hydraulic circuit unit 10 automatic transmission controller (transmission control means)
10A transmission control unit (transmission control means)
10B Neutral traveling control unit (control unit)
DESCRIPTION OF SYMBOLS 11 Inhibitor switch 12 Vehicle speed opening sensor 13 Accelerator opening sensor 14 Brake switch 100 Engine controller (engine control means)
31 1st planetary gear mechanism (PG1)
32 2nd planetary gear mechanism (PG2)
33 3rd planetary gear mechanism (PG3)
34 4th planetary gear mechanism (PG4)
31S-34S Sun gear 31C-34C Carrier 31R-34R Ring gear M1 Input rotary member (first rotary member)
M2 output rotary member (second rotary member)
M3 1st intermediate rotating member (3rd rotating member)
M4 2nd intermediate rotation member (4th rotation member)
M5 Third intermediate rotating member (fifth rotating member)
M6 4th intermediate rotation member (6th rotation member)
M7 Fifth intermediate rotation member (seventh rotation member)
M8 6th intermediate rotating member (8th rotating member)
K81 First clutch (first friction engagement element)
K27 Second clutch (second friction engagement element)
K38 Third clutch (third friction engagement element)
B05 First brake (fourth friction engagement element)
B06 2nd brake (5th friction engagement element)
B08 Third brake (sixth friction engagement element)

Claims (8)

A control device for a vehicle including a stepped transmission having an input rotary member including an input shaft and an output rotary member including an output shaft,
When performing neutral traveling control in which the power between the input rotating member and the output rotating member is cut off during traveling of the vehicle, the output shaft torque related to the output shaft increases as the vehicle speed decreases. And a neutral pattern is changed. A control device for a vehicle including a stepped transmission having an input rotary member including an input shaft and an output rotary member including an output shaft,
When performing the neutral traveling control that puts the power between the input rotary member and the output rotary member in a power cutoff state while the vehicle is traveling, the neutral is controlled such that the inertia applied to the output shaft increases as the vehicle speed decreases. A vehicle control device for changing a pattern. In claim 1 or claim 2,
Comprising a plurality of intermediate rotating members provided between the input rotating member and the output rotating member,
A vehicle control device, wherein a neutral pattern is selected during which the output rotation member and the plurality of intermediate rotation members are in a power transmission state during the neutral traveling control. In claim 3,
The neutral pattern is changed by changing the combination of the engagement of the plurality of friction engagement elements of the stepped transmission in accordance with the vehicle speed, and the friction engagement element that continues the engagement state before and after the change is present. A control device for a vehicle, wherein a neutral pattern is selected. In claim 4,
When changing the neutral pattern according to the vehicle speed, the neutral pattern is selected such that there is a frictional engagement element that maintains the engagement state in the entire vehicle speed range. In claim 1 , or any one of claims 3 to 5, which refers to claim 1 ,
Control device for a vehicle, characterized in that to change the said neutral pattern based on a neutral pattern the output shaft torque is maximized in accordance with the vehicle speed range. In claim 2 or any one of claims 3 to 5 citing claim 2 ,
Control device for a vehicle, characterized in that to change the said neutral pattern based on neutral pattern inertia is maximized applied before SL output shaft in accordance with the vehicle speed range. In claim 6 or 7 ,
A part of the neutral pattern in which the output shaft torque or the inertia applied to the output shaft is the largest depending on the vehicle speed range, and a part of the neutral pattern is thinned out, and the neutral pattern is changed based on the remaining neutral pattern. Control device.

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