JP2016196952A - Vehicular control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular control device capable of suppressing a running resistance at a coast traveling time thereby to improve a fuel economy.SOLUTION: A vehicular control device is mounted on only one drive shaft 12R of right and left drive shafts 12R and 12L connected to a differential gear 10, and is equipped with a clutch 11 for connecting and disconnecting the differential gear 10 and a drive wheel 5R connected to the one drive shaft 12R. The vehicular control device releases the clutch 11 when it detects a coast run.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle control device that suppresses running resistance during coasting.

  Conventionally, Patent Document 1 improves the fuel efficiency by releasing the clutch between the engine and the transmission during coasting and suppressing the resistance during coasting.

JP 2014-136476 A

However, in the above prior art, even if the clutch is released during coasting, the transmission between the drive wheels and the clutch also rotates with the drive wheels, so that running resistance is generated and fuel consumption is improved. It was difficult to achieve enough.
An object of the present invention is to provide a vehicle control apparatus capable of suppressing the running resistance during coasting and improving the fuel efficiency by paying attention to the above problems.

  For this purpose, the vehicle control apparatus according to the present invention is provided on only one drive shaft of the left and right drive shafts connected to the differential gear, and the drive wheels connected to the differential gear and one drive shaft. A clutch that connects and disconnects between the two is provided, and when coasting is detected, the clutch is released.

  Therefore, by adopting only one clutch, the relative rotation between the drive wheel and the differential gear case can be allowed, so the cost during coasting can be reduced and the coasting distance can be reduced while suppressing the cost increase. By securing it, fuel efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic system diagram showing a vehicle drive system and its overall control system according to a first embodiment. In the vehicle of Example 1, it is the schematic showing the rotation state of each element of the differential gear vicinity at the time of clutch fastening / release. 3 is a flowchart showing a clutch control process executed by the vehicle control apparatus of the first embodiment. FIG. 5 is a schematic system diagram illustrating a vehicle drive system and an overall control system thereof according to a second embodiment.

[Example 1]
FIG. 1 is a schematic system diagram showing a vehicle drive system and its overall control system according to a first embodiment. The vehicle in FIG. 1 is a front-wheel drive vehicle, and an engine 1 is mounted on the front side of the vehicle as a power source. The engine 1 is started by the starter motor 3. The engine 1 is connected to a front drive wheel 5R and a left drive wheel 5L (hereinafter referred to as a right drive wheel 5R and a left drive wheel) via a V-belt continuously variable transmission 4 having a torque converter 2 having a lock-up clutch 2a. The drive wheels 5L are collectively referred to as the drive wheels 5).

  The variator CVT of the continuously variable transmission 4 is a V belt type continuously variable transmission mechanism including a primary pulley 6, a secondary pulley 7, and a V belt 8 (endless flexible member) spanned between these pulleys 6 and 7. is there. The V belt 8 employs a configuration in which a plurality of elements are bundled by an endless belt, but may be a chain system or the like, and is not particularly limited. The primary pulley 6 is coupled to the crankshaft of the engine 1 via the torque converter 2, and the secondary pulley 7 is a final gear comprising a final pinion 9a provided on the output shaft 80 and a final ring gear 9b provided on the differential gear 10. It is coupled to the drive wheel 5 through the set 9.

  During engine power transmission, the pulley V groove width of the primary pulley 6 is reduced while the pulley V groove width of the secondary pulley 7 is increased to increase the winding arc diameter of the V belt 8 and the primary pulley 6 and at the same time Decrease the diameter of the winding arc with pulley 7. As a result, the variator CVT upshifts to the high pulley ratio. When the upshift to the High side gear ratio is performed to the limit, the gear ratio is set to the maximum gear ratio.

  Conversely, by increasing the pulley V groove width of the primary pulley 6 and decreasing the pulley V groove width of the secondary pulley 7, the winding pulley diameter of the V belt 8 and the primary pulley 6 is reduced, and at the same time the secondary pulley 7 Increase the winding arc diameter. This causes the variator CVT to downshift to a low pulley ratio. When downshifting to the low side gear ratio is performed to the limit, the gear shift is set to the minimum gear ratio. The variator CVT calculates an actual gear ratio based on the rotation speed of the primary pulley 6 and the rotation speed of the secondary pulley 7, and hydraulic control of each pulley is performed so that the actual gear ratio becomes the target gear ratio.

  The differential gear 10 includes a final ring gear 9b provided on the outer periphery of the differential case 10a, a pinion shaft 10b that rotates integrally with the differential case 10a, a plurality of pinions 10c that are rotatably supported by the pinion shaft 10b, and a pinion 10c. And a right side gear 10e that meshes with the pinion 10c. A left drive shaft 12L is connected to the left side gear 10d. A right first drive shaft 12R is connected to the right side gear 10e. A clutch 11 is provided between the differential gear 10 and the right drive wheel 5R. A right first drive shaft 12R is connected to one side of the clutch 11, and a right second drive shaft 12R1 is connected to the other side. The right second drive shaft 12R1 rotates integrally with the right drive wheel 5R. Hereinafter, the left drive shaft 12L, the right first drive shaft 12R, and the right second drive shaft 12R1 are also collectively referred to as the drive shaft 12.

  The controller 20 receives an accelerator opening signal APO from an accelerator opening sensor 21 that detects an accelerator pedal opening, and a vehicle speed signal VSP from a vehicle speed sensor 22 that detects a vehicle speed. The controller 20 controls the operation state of the engine 1, the operation state of the continuously variable transmission 4, and the connection / disconnection state of the clutch 11 based on various sensor signals.

  FIG. 2 is a schematic diagram illustrating a rotation state of each element in the vicinity of the differential gear when the clutch is engaged / released in the vehicle of the first embodiment. FIG. 2 (a) shows when the clutch is engaged, FIG. 2 (b) shows when the clutch is released during coasting, and FIG. 2 (c) shows when the clutch is released during sudden braking. In FIG. 2, the rotation element indicated by a thick solid line represents a positive rotation state, the rotation element indicated by a thick dotted line represents a negative rotation state, and the rotation element indicated by a thin solid line has stopped. Represents. As shown in FIG. 2A, when the vehicle runs on a coast while the clutch 11 is engaged, the left drive shaft 12L and the right first and second drive shafts 12R, 12R1 are driven by the left and right drive wheels 5. . At this time, the rotation of the left drive shaft 12L is transmitted to the left side gear 10d. On the other hand, the rotation of the right first drive shaft 12R is transmitted to the right side gear 10e.

  In coast running, since the running resistance acting on the left and right drive wheels is the same, the pinion 10c does not rotate, receives the torque of the left side gear 10d and the right side gear 10e, and transmits the torque in the direction orthogonal to the pinion shaft 10b. . Since the pinion shaft 10b is fixed to the differential case 10a, the differential case 10a rotates in the same rotational direction as the left and right drive shafts 12L and 12R by the torque acting in the axial direction of the pinion shaft 10b. Therefore, the final ring gear 9b provided in the differential case 10a also rotates, and the secondary pulley 7 rotates through the final pinion 9a. Even if a differential rotation occurs between the left and right drive wheels 5 due to a slight turn, the differential case 10a rotates only by rotating the pinion 10c around the pinion shaft 10b by the differential rotation. There is no change.

  At this time, in order to reduce the running resistance during coast running, it is conceivable to release the lock-up clutch 2a of the torque converter 2 and reduce the friction of the engine 1. However, as the left and right drive wheels 5 rotate, the differential case 10a and the final ring gear 9b rotate, and the variator CVT also rotates. Then, since there are many rotation elements at the time of coast driving | running | working and inertia is also large, there exists a problem that driving | running | working resistance is large and coast driving | running distance cannot fully be obtained.

  Further, from the viewpoint of avoiding belt slip at the variator CVT, the hydraulic pressure must be supplied to the primary pulley 6 and the secondary pulley 7 even during coasting. Then, it is necessary to continue the operation of the oil pump for hydraulic control. If a mechanical oil pump driven by the engine 1 is provided, if the lock-up clutch 2a is released and the engine 1 is stopped, the mechanical oil pump also stops, so the necessary hydraulic pressure cannot be secured. . Therefore, in order to stop the engine 1 during coasting from the viewpoint of improving fuel efficiency, it is necessary to install a separate electromagnetic oil pump or the like and adopt a configuration that can ensure hydraulic pressure even if the engine 1 stops, resulting in an increase in cost. There is also a problem.

  It is also conceivable that a separate clutch is provided between the variator CVT and the differential gear 10 and the clutch is released to avoid rotation of the variator CVT during coasting. However, since the differential case 10a, the final ring gear 9b, and the final pinion 9a rotate, the inertia and friction are still large. In particular, the differential case 10a is heavy, and the final ring gear 9b has a very large radius, so that the friction when it is accompanied increases.

  Furthermore, assume a sudden braking state in which, for example, antilock brake control is activated. In a vehicle equipped with a belt-type continuously variable transmission, the lockup clutch 2a is engaged in many driving states to improve fuel efficiency. At this time, since the drive wheel 5 is sufficiently smaller than the inertia of the vehicle, the rotation speed of the drive wheel 5 is reduced at a time during sudden braking by the friction brake, and is locked in some cases. Then, the variator CVT and the engine 1 also stop rotating through the differential gear 10, and problems such as belt slip and engine stall may occur. Therefore, in order to ensure a sufficient belt pressing force at the time of sudden braking, it may be possible to provide a separate electromagnetic oil pump or the like so that the necessary high hydraulic pressure can be supplied. However, if an electromagnetic oil pump is separately installed, the cost increases, and electric power for driving the electromagnetic oil pump must be secured, so that fuel efficiency cannot be improved.

  Therefore, in the first embodiment, when a predetermined traveling state is detected, the clutch 11 provided between the differential gear 10 and the right drive wheel 5R is released. In other words, a configuration is adopted in which the relative rotation between the two drive wheels 5 and the differential case 10a is allowed only by releasing one clutch 11.

FIG. 3 is a flowchart showing a clutch control process executed by the vehicle control apparatus of the first embodiment.
In step S1, it is determined whether or not coasting is in progress. If coasting is not in progress, the process proceeds to step S2. If coasting is in progress, the process proceeds to step S3 and the clutch 11 is released. Whether or not coasting is being performed may be determined, for example, based on whether or not the accelerator pedal opening APO is less than a predetermined value, and is not particularly limited.
In step S2, it is determined whether or not sudden braking is being performed. If sudden braking is not being performed, the routine proceeds to step S4 where the clutch 11 is engaged. On the other hand, when it is determined that sudden braking is in progress, the routine proceeds to step S3 where the clutch 11 is turned off. Whether or not sudden braking is being performed may be determined based on, for example, whether or not the rate of change of the driving wheel speed is equal to or greater than a predetermined value, and is not particularly limited.

  That is, in the vehicle of the first embodiment, the clutch 11 is released during coasting. Therefore, as shown in FIG. 2B, only the right second drive shaft 12R1 is brought along the right drive wheel 5R. On the other hand, the left drive wheel 5L is accompanied by the left side gear 10d together with the left drive shaft 12L. Accordingly, the pinion 10c also rotates. However, the right first drive shaft 12R can freely rotate by releasing the clutch 11, so that the left drive shaft 12L rotates in reverse with the rotation of the pinion 10c. At this time, no torque acts in the direction orthogonal to the pinion shaft 10b, and the differential case 10a does not rotate. Therefore, the final ring gear 9b does not rotate, and the variator CVT does not rotate. Therefore, friction during coasting can be reduced, and fuel efficiency can be improved by securing the coasting distance.

  In the vehicle of the first embodiment, the clutch 11 is released during sudden braking. Therefore, as shown in FIG. 2C, when the left driving wheel 5L is locked, the rotation of the left side gear 10d stops, and when the right driving wheel 5R is locked, the rotation of the second drive shaft 12R1 stops. To do. At this time, the differential case 10a rotates in accordance with the rotation of the engine 1 and the variator CVT, and the pinion shaft 10b rotates integrally with the differential case 10a. Since the left side gear 10d is locked together with the left drive wheel 5L, the pinion 10c rotates around the pinion shaft 10b. With this rotation, the right side gear 10e rotates and the right first drive shaft 12R also rotates. However, since the clutch 11 is released, it can rotate freely. In other words, even if the drive wheel 5 is locked, by releasing the clutch 11, the engine 1 and the variator CVT can rotate freely without a sudden decrease in rotation. Therefore, belt slip and engine stall of the variator CVT can be avoided without providing an electromagnetic oil pump or the like.

As described above, the effects listed below are obtained in the first embodiment.
(1) Engine 1 (power source)
Continuously variable transmission 4 (transmission) coupled to the output shaft of engine 1,
A differential gear 10 meshing with the output shaft of the continuously variable transmission 4,
Left and right drive shafts 12 connected to the differential gear 10, and
Left and right drive wheels connected via left and right drive shafts 12,
Of the left and right drive shafts 12, provided only on the right first drive shaft 12R and the right second drive shaft 12R1 (one drive shaft), the differential gear 10, the right first drive shaft 12R and the right second drive shaft 12R1 A clutch 11 that connects and disconnects between the right drive wheel 5R (drive wheel) connected to
When coasting is detected, a controller 20 (control means) for releasing the clutch 11,
Equipped with.
Therefore, by adopting only one clutch 11, the relative rotation between the drive wheel 5 and the differential case 10a can be allowed, so the friction during coasting can be reduced and the coasting distance can be reduced while suppressing cost increase. The fuel consumption can be improved by ensuring

(2) In the vehicle control device described in (1) above,
The continuously variable transmission 4 has a variator CVT (belt type continuously variable transmission).
If the variator CVT rotates during coasting, hydraulic pressure must be supplied to the primary pulley 6 and the secondary pulley 7 even during coasting from the viewpoint of avoiding belt slippage in the variator CVT. Then, it is necessary to continue the operation of the oil pump for hydraulic control. When a mechanical oil pump driven by the engine 1 is provided, if the lock-up clutch 2a is released and the engine 1 is stopped, the mechanical oil pump is also stopped, so that necessary hydraulic pressure cannot be secured. Therefore, in order to stop the engine 1 during coasting from the viewpoint of improving fuel efficiency, it is necessary to install a separate electromagnetic oil pump or the like and adopt a configuration that can ensure hydraulic pressure even if the engine 1 stops, resulting in an increase in cost. . On the other hand, by releasing the clutch 11 during coasting, the variator CVT does not rotate, belt slippage can be avoided, and cost increases associated with securing hydraulic pressure can be avoided.

(3) In the vehicle control device according to (2),
The controller 20 releases the clutch 11 when detecting sudden braking.
In the sudden braking state, the inertia of the drive wheel 5 is sufficiently smaller than the inertia of the vehicle, so that the rotation speed of the drive wheel 5 is reduced at a stroke by the friction brake, and sometimes locks. Then, the variator CVT and the engine 1 also stop rotating through the differential gear 10, and there is a possibility that belt slip or engine stall may occur. Also, in order to ensure sufficient belt pressing force during sudden braking, a separate electromagnetic oil pump, etc., that can supply the required high hydraulic pressure will increase costs and power for driving the electromagnetic oil pump. The fuel consumption cannot be improved. On the other hand, by releasing the clutch 11, the variator CVT and the engine 1 do not stop. Therefore, it is possible to avoid belt slip and engine stall without increasing the cost and improve fuel efficiency.

(4) The engine 1 is mounted in front of the vehicle, and the left and right drive wheels 5 are front wheels.
Therefore, the friction of the differential gear 10 can be reduced and the friction of the variator CVT and the engine 1 can be reduced only by releasing one clutch 11.

[Example 2]
Next, Example 2 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 4 is a schematic system diagram showing a vehicle drive system and its overall control system according to the second embodiment. In the first embodiment, an example in which the torque converter 2 and the continuously variable transmission 4 are mounted is shown. On the other hand, the second embodiment is different in that a parallel biaxial always-mesh manual transmission 400 is mounted. The manual transmission 400 includes a main clutch 200 that is connected to and disconnected from the engine 1 by an operation of the driver's clutch pedal 201, and a synchronization mechanism 402 that the driver operates the shift lever 401 to determine the gear position. Have. The engine 1 is separated from the right driving wheel 5R and the left driving wheel 5L, which are front wheels, through the main clutch 200 (hereinafter, the right driving wheel 5R and the left driving wheel 5L are collectively referred to as the driving wheel 5). Drive coupling possible.

  In the case of the manual transmission 400, the main clutch 200 is connected / disconnected by the driver's operation of the clutch pedal 201. Therefore, in a vehicle equipped with the manual transmission 400, when trying to improve the fuel efficiency during coasting, the main clutch 200 can be connected and disconnected in addition to the driver's operation, and the driver's operation of the clutch pedal 201 can be performed. A controlled clutch that can be actuated according to the situation must be adopted. Such a controlled clutch is very expensive and causes an increase in cost. On the other hand, in the second embodiment, by releasing the clutch 11 during coasting, the engine 1 can be stopped even if the main clutch 200 remains connected. It is possible to improve fuel efficiency by avoiding cost increase. Further, as in the first embodiment, since the accompanying case of the differential case 10a and the manual transmission 400 can be avoided, the friction can be greatly reduced, and the fuel efficiency can be improved by securing the coasting distance.

  Also, if the driver does not operate the clutch pedal 201 during sudden braking, the engine 1 also stops rotating via the differential gear 10 and the manual transmission 400 if the main clutch 200 remains connected. This may cause an engine stall. Further, if the main clutch 200 is a controlled clutch in order to avoid engine stall, the cost increases. On the other hand, by releasing the clutch 11, engine stall can be avoided, and drivability can be improved without incurring a cost increase.

As described above, the following operational effects are obtained in the second embodiment.
(5) The transmission is a manual transmission 400 that has a main clutch 200 that connects / disconnects between the engine 1 and the transmission, and that shifts according to a driver's main clutch connection / disconnection operation and shift operation.
Therefore, driving performance can be improved while avoiding cost increase and improving fuel economy.

As described above, the present invention has been described based on the first and second embodiments. However, other configurations than the above are also included in the present invention. For example, in the embodiment, an example is shown in which an engine is used as a power source. However, the present invention is not limited to an engine, and an electric motor may be used, or a hybrid vehicle including both an engine and an electric motor may be used. .
Further, although the front wheel drive vehicle has been described in the embodiment, it may be a rear wheel drive vehicle or a four wheel drive vehicle. However, in the case of a four-wheel drive vehicle, since a differential gear is provided on both the front wheel side and the rear wheel side, one clutch is provided between the front wheel side differential gear and one front wheel side drive wheel. The effect of the present invention can be obtained by providing one clutch also between the wheel-side differential gear and the one rear wheel-side drive wheel.

  In the first embodiment, the belt-type continuously variable transmission is adopted as the automatic transmission. However, the belt-type continuously variable transmission is not limited to the belt type, and other types of continuously variable transmissions may be used. It doesn't matter. Further, the clutch of the present invention may be adopted in a vehicle having a clutch between the transmission and the differential gear. This is because the rotation of the differential case can be avoided and the friction can be reduced.

1 engine
2 Torque converter
2a Lock-up clutch
3 Starter motor
4 V belt type continuously variable transmission
5 Drive wheels
6 Primary pulley
7 Secondary pulley
8 V belt
9 Final gear set
9a Final pinion
9b Final ring gear
10 Differential gear
10a differential case
11 Clutch
12 Drive shaft
CVT variator (continuously variable transmission)
200 main clutch
201 clutch pedal
401 Shift lever
400 manual transmission

Claims (5)

Power source,
A transmission coupled to the output shaft of the power source;
A differential gear meshing with the output shaft of the transmission;
Left and right drive shafts connected to the differential gear;
Left and right drive wheels connected via the left and right drive shafts;
A clutch that is provided only on one of the left and right drive shafts, and that connects and disconnects between the differential gear and the drive wheels connected to the one drive shaft;
When coasting is detected, control means for releasing the clutch;
A vehicle control device comprising: The vehicle control device according to claim 1,
The vehicle control apparatus, wherein the transmission is a belt-type continuously variable transmission. The vehicle control device according to claim 2,
The control device for a vehicle, wherein the control means releases the clutch when sudden braking is detected. In the hybrid vehicle control device according to any one of claims 1 to 3,
The transmission has a main clutch that connects and disconnects between the power source and the transmission, and is a manual transmission that changes gears by a driver's main clutch connection / disconnection operation and shift operation. Control device. The vehicle control device according to any one of claims 1 to 4,
The power source is disposed in front of the vehicle,
The left and right drive wheels are front wheels.

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