Vehicle control system

Abstract

The present invention provides a vehicle control device that facilitates switching the engaged clutch to the disengaged state when such a switch is required. [Solution] When the power transmission path between the power source and the drive wheels is in a power transmission state during driving, if a switch to the disengaged state of the meshing clutch is required, an actuator is driven to apply the force necessary to disengage the meshing clutch, and thereafter the friction clutch is switched to the disengaged state. This makes it easier to disengage the meshing teeth even when the input torque to the meshing clutch is large, in which case the meshing teeth would not disengage even if the force necessary to disengage the meshing clutch is applied after the friction clutch is disengaged. Therefore, when a switch to the disengaged state of the meshing clutch is required, it is possible to easily switch the meshing clutch to the disengaged state.

Description

Technical Field

[0001] The present invention relates to a control device for a vehicle, comprising an engagement clutch and a friction clutch provided between a power source and the engagement clutch.

Background Art

[0002] A control device for a vehicle including an engagement clutch provided in a power transmission path between a power source and drive wheels, which is brought into an engaged state by the engagement of meshing teeth and into a released state by the release of the meshing, an actuator for switching between the engaged state and the released state of the engagement clutch, and a friction clutch provided in the power transmission path between the power source and the engagement clutch, is well known. For example, the transmission control device for a vehicle described in Patent Document 1 is such a device. In this Patent Document 1, when a shift of a transmission in which a gear stage is switched by switching between the engaged state and the released state of a predetermined engagement clutch is required, the torque capacity of the friction clutch is reduced and the engagement clutch forming the current gear stage is released, and then, a technique of engaging the engagement clutch forming the gear stage after the shift is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, when switching the meshing clutch to the disengaged state, even if the friction clutch is disengaged, input torque is generated to the meshing clutch due to the friction and inertia of the rotating members and parts connected to those rotating members in the downstream part of the friction clutch and the upstream part of the meshing clutch. In that case, depending on the magnitude of the input torque to the meshing clutch, it may become difficult to disengage the meshing teeth in the meshing clutch, and there is a risk that the meshing clutch may become difficult to switch to the disengaged state.

[0005] The present invention was made against the above circumstances, and its objective is to provide a vehicle control device that can easily switch the meshing clutch to the disengaged state when switching to the disengaged state of the meshing clutch is required. [Means for solving the problem]

[0006] The gist of the first invention is a control device for a vehicle comprising: (a) a meshing clutch provided in a power transmission path between a power source and a drive wheel, which is engaged by the meshing of meshing teeth and released when the meshing is released; an actuator for switching between the engaged and released states of the meshing clutch; and a friction clutch provided in the power transmission path between the power source and the meshing clutch, wherein (b) when the vehicle is running and the power transmission path between the power source and the drive wheel is in a state where power can be transmitted, the control device includes a clutch control unit that drives the actuator to apply the force necessary to release the meshing in the meshing clutch, and thereafter switches the friction clutch to the released state. [Effects of the Invention]

[0007] According to the first invention, when a switch to the disengaged state of the meshing clutch is required during driving while the power transmission path between the power source and the drive wheels is in a power transmission state, an actuator is driven to apply the force necessary to disengage the meshing clutch, and thereafter the friction clutch is switched to the disengaged state. Here, it has been found that in the transient state from the engaged state to the disengaged state of the friction clutch, there is a timing when the input torque to the meshing clutch is smaller than when the friction clutch is in the disengaged state. As a result, even when the input torque to the meshing clutch is large, such that the meshing teeth do not disengage even when the force necessary to disengage the meshing clutch is applied after the friction clutch has been disengaged, the meshing teeth can be easily disengaged by first applying the force necessary to disengage the meshing teeth, and then starting the switch to the disengaged state of the friction clutch. Therefore, when a switch to the disengaged state of the meshing clutch is required, it is possible to easily switch the meshing clutch to the disengaged state. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram illustrates the schematic configuration of a vehicle to which the present invention is applied. [Figure 2] This diagram illustrates the control functions and key components of the control system for various control functions in a vehicle. [Figure 3] This flowchart explains the key aspects of the control operation of an electronic control unit, specifically the control operation to facilitate switching the dog clutch to the released state when such a switch is required. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Examples]

[0010] Figure 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied. In Figure 1, the vehicle 10 comprises an engine 12, drive wheels 14, and a power transmission device 16 provided in the power transmission path between the engine 12 and the drive wheels 14. The engine 12 functions as the power source of the present invention.

[0011] The engine 12 is, for example, a known internal combustion engine. The engine torque Te of the engine 12 is controlled by an electronic control device 90 (see Figure 2), which will be described later, by controlling the throttle actuator, fuel injection device, ignition device, etc., provided in the vehicle 10.

[0012] The power transmission device 16 includes a K1 clutch 18, a transmission 20 that transmits power from the engine 12 to the drive wheels 14, and the like. The power transmission device 16 also includes a propeller shaft 22 connected to the output shaft 20o, a differential gear 24 connected to the propeller shaft 22, and a pair of drive shafts 26 connected to the differential gear 24. The output shaft 20o is the output rotating member of the transmission 20.

[0013] The K1 clutch 18 is provided in the power transmission path between the engine 12 and the transmission 20 (particularly the input shaft 20i). The input shaft 20i is the input rotating member of the transmission 20. The K1 clutch 18 is a known hydraulic friction engagement device, for example, composed of a multi-plate or single-plate clutch. The K1 clutch 18 is the friction clutch of the present invention, provided in the power transmission path between the engine 12 and the dog clutch 50 described later. The control state of the K1 clutch 18 is switched by changing the K1 torque Tk1, which is supplied by the K1 hydraulic pressure PRk1 from the hydraulic control circuit 28 (see Figure 2) provided in the vehicle 10. The K1 hydraulic pressure PRk1 is the hydraulic pressure regulated by the hydraulic control circuit 28. The K1 torque Tk1 is the torque capacity of the K1 clutch 18. The control state is an operating state such as an engaged state, a slipped state, or a released state.

[0014] In the vehicle 10, when the K1 clutch 18 is engaged, the engine 12 and the transmission 20 are connected in a way that allows for power transmission. On the other hand, when the K1 clutch 18 is disengaged, power transmission between the engine 12 and the transmission 20 is interrupted. The K1 clutch 18 functions as a clutch that connects and disconnects power transmission between the engine 12 and the transmission 20. In the power transmission device 16, when the K1 clutch 18 is engaged, the power output from the engine 12 is transmitted to the drive wheels 14 sequentially via the K1 clutch 18, the transmission 20, the propeller shaft 22, the differential gear 24, and the drive shaft 26, etc.

[0015] The transmission 20 comprises an input shaft 20i and an output shaft 20o as multiple rotating shafts arranged parallel to each other. The transmission 20 is a so-called parallel two-shaft transmission in which multiple gear stages (also called gear ratios) are formed by reducing or increasing the rotation of the input shaft 20i by a predetermined gear ratio (also called gear ratio) γ (=Ni / No). "Ni" is the input rotational speed Ni of the transmission 20, which is the rotational speed of the input shaft 20i. "No" is the output rotational speed No of the transmission 20, which is the rotational speed of the output shaft 20o. The input shaft 20i is rotatable around the rotation axis CL1. The output shaft 20o is rotatable around the rotation axis CL2.

[0016] The transmission 20 is equipped with multiple gear pairs 30 that are always meshed. The gear pairs 30, arranged sequentially from the engine 12 toward the drive wheels 14 in the direction of the rotation axis CL1, include a 2nd gear pair 30a, a 5th gear pair 30b, a 3rd gear pair 30c, a 6th gear pair 30d, a 1st gear pair 30e, and a 4th gear pair 30f. The direction of the rotation axis CL1 is synonymous with the axial direction of the input shaft 20i.

[0017] The gear pair 30 is composed of a drive gear 32 and a driven gear 34 that always meshes with the drive gear 32. The drive gear 32 includes a two-speed drive gear 32a, a five-speed drive gear 32b, a three-speed drive gear 32c, a six-speed drive gear 32d, a one-speed drive gear 32e, and a four-speed drive gear 32f. The driven gear 34 includes a two-speed driven gear 34a, a five-speed driven gear 34b, a three-speed driven gear 34c, a six-speed driven gear 34d, a one-speed driven gear 34e, and a four-speed driven gear 34f.

[0018] The drive gear 32 is provided so as to be relatively rotatable with respect to the input shaft 20i. The driven gear 34 is fixed to the output shaft 20o so as not to be relatively rotatable. When the drive gear 32 is rotated, the driven gear 34 and the output shaft 20o are rotated at a rotational speed corresponding to the gear ratio γ of the gear pair 30.

[0019] The transmission 20 includes a switching mechanism 36 disposed on the input shaft 20i. The switching mechanism 36 includes a first switching mechanism 36a, a second switching mechanism 36b, and a third switching mechanism 36c. The first switching mechanism 36a is disposed between the two-speed drive gear 32a and the five-speed drive gear 32b and adjacent to them in the direction of the rotation axis CL1. The second switching mechanism 36b is disposed between the three-speed drive gear 32c and the six-speed drive gear 32d and adjacent to them in the direction of the rotation axis CL1. The third switching mechanism 36c is disposed between the one-speed drive gear 32e and the four-speed drive gear 32f and adjacent to them in the direction of the rotation axis CL1.

[0020] The switching mechanism 36 switches the power transmission state in the gear pair 30 between a power transmissible state and a power non-transmissible state. The switching mechanism 36 is a disconnecting and connecting device that can switch between a connecting state in which one of the drive gears 32 disposed adjacent to each other and the input shaft 20i are connected and rotate integrally, and a disconnecting state in which the other and the input shaft 20i are disconnected and rotate relatively.

[0021] For example, when the two-speed drive gear 32a and the input shaft 20i are connected via the first switching mechanism 36a, the transmission 20 is switched to a power transmissible state via the two-speed gear pair 30a, and a two-speed gear stage 2nd is formed in the transmission 20. Also, when the five-speed drive gear 32b and the input shaft 20i are connected via the first switching mechanism 36a, the transmission 20 is switched to a power transmissible state via the five-speed gear pair 30b, and a five-speed gear stage 5th is formed in the transmission 20. The same applies to the three-speed gear stage 3rd, the six-speed gear stage 6th, the first-speed gear stage 1st, and the four-speed gear stage 4th.

[0022] In the switching mechanism 36, switching meshing teeth 38 are formed at a position facing the drive gear 32 in the direction of the rotation axis CL1. On the drive gear 32, gear-side meshing teeth 40 that can mesh with the switching meshing teeth 38 are formed at a position facing the switching mechanism 36 in the direction of the rotation axis CL1. The switching meshing teeth 38 include two-speed switching meshing teeth 38a, five-speed switching meshing teeth 38b, three-speed switching meshing teeth 38c, six-speed switching meshing teeth 38d, first-speed switching meshing teeth 38e, and four-speed switching meshing teeth 38f. The gear-side meshing teeth 40 include two-speed gear-side meshing teeth 40a, five-speed gear-side meshing teeth 40b, three-speed gear-side meshing teeth 40c, six-speed gear-side meshing teeth 40d, first-speed gear-side meshing teeth 40e, and four-speed gear-side meshing teeth 40f.

[0023] For example, the two-speed switching meshing teeth 38a are the switching meshing teeth 38 formed at a position facing the two-speed drive gear 32a in the direction of the rotation axis CL1 in the first switching mechanism 36a. The same applies to the switching meshing teeth 38 other than the two-speed switching meshing teeth 38a. Also, the two-speed gear-side meshing teeth 40a are the gear-side meshing teeth 40 formed at a position facing the first switching mechanism 36a in the direction of the rotation axis CL1 in the two-speed drive gear 32a and that can mesh with the two-speed switching meshing teeth 38a. The same applies to the gear-side meshing teeth 40 other than the two-speed gear-side meshing teeth 40a.

[0024] The transmission 20 is a dog transmission having a dog clutch 50. The dog clutch 50 is a known meshing clutch composed of a switching mechanism 36 having switching meshing teeth 38, and gear-side meshing teeth 40, etc. The switching meshing teeth 38 and the gear-side meshing teeth 40 are meshing teeth, or dog teeth, that constitute a part of the dog clutch 50. The dog clutch 50 is a meshing clutch of the present invention, provided in the power transmission path between the engine 12 and the drive wheel 14, which is engaged by the meshing of meshing teeth and disengaged by releasing the meshing.

[0025] The dog clutch 50 includes a 2nd gear dog clutch 50a, a 5th gear dog clutch 50b, a 3rd gear dog clutch 50c, a 6th gear dog clutch 50d, a 1st gear dog clutch 50e, and a 4th gear dog clutch 50f. For example, the 2nd gear dog clutch 50a is composed of a first switching mechanism 36a equipped with 2nd gear switching meshing teeth 38a, and 2nd gear side meshing teeth 40a, etc. The same applies to the dog clutches 50 other than the 2nd gear dog clutch 50a.

[0026] The transmission 20 is configured to be able to shift to six forward gears by activating the switching mechanism 36. The switching mechanism 36 is activated by moving it in the direction of the rotation axis CL1. The switching mechanism 36 is moved in the direction of the rotation axis CL1 by a shift mechanism 60 provided in the transmission 20.

[0027] The shift mechanism 60 is a mechanism for moving the switching mechanism 36 in the direction of the rotation axis CL1. The shift mechanism 60 comprises a shift fork 62, a shift barrel 64, and a shift actuator 66. The shift fork 62 includes a first shift fork 62a that fits into the first switching mechanism 36a, a second shift fork 62b that fits into the second switching mechanism 36b, and a third shift fork 62c that fits into the third switching mechanism 36c. The shift barrel 64 has a shift groove 68 formed therein that defines the position of the switching mechanism 36 in the direction of the rotation axis CL1 via the shift fork 62. The shift groove 68 includes a first shift groove 68a, a second shift groove 68b, and a third shift groove 68c. For example, the first shift groove 68a defines the position of the first switching mechanism 36a in the direction of the rotation axis CL1 via the first shift fork 62a. The same applies to the second shift groove 68b and the third shift groove 68c. The shift actuator 66 is an actuator that rotates the shift barrel 64.

[0028] The shift groove 68 is formed along the circumferential direction of the shift barrel 64, with a portion of its circumferential direction bent in the axial direction of the shift barrel 64. Therefore, when the shift barrel 64 is rotated, the shift fork 62 moves along the groove shape of the shift groove 68 in the axial direction of the shift barrel 64. In addition, when the shift fork 62 moves in the axial direction of the shift barrel 64, the switching mechanism 36 moves in conjunction with the shift fork 62 in the direction of the rotation axis CL1.

[0029] Each shift groove 68 has a different shape relative to its circumferential position on the shift barrel 64. The shape of the shift groove 68 is such that, as the shift barrel 64 rotates in one direction, the transmission 20 sequentially upshifts from 1st gear to 6th gear. In addition, the shape of the shift groove 68 is such that, as the shift barrel 64 rotates in the other direction (reverse direction), the transmission 20 sequentially downshifts from 6th gear to 1st gear.

[0030] Furthermore, the shape of the shift groove 68 is formed so that the switching mechanism 36 is moved in the direction of the rotation axis CL1 at an appropriate timing during the transition phase of upshifting and downshifting, that is, so that the gear shifting process proceeds at an appropriate timing. Accordingly, the transmission 20 shifts gears by switching the engaged and disengaged state of the dog clutch 50 as the switching mechanism 36 is moved to a predetermined position in the direction of the rotation axis CL1 in accordance with the rotation of the shift barrel 64. The engaged and disengaged states of the dog clutch 50 include a connected state in which power transmission is possible between the drive gear 32 and the input shaft 20i, and a disconnected state in which power transmission between the drive gear 32 and the input shaft 20i is interrupted. The engaged state of the dog clutch 50 is synonymous with the engaged state of the dog clutch 50, and the disengaged state of the dog clutch 50 is synonymous with the released state of the dog clutch 50.

[0031] The shift mechanism 60 is an actuator of the present invention that switches between the engaged and disengaged states of the dog clutch 50. The transmission 20 is a transmission of the present invention in which the gear stage is automatically switched by the shift mechanism 60 switching between the engaged and disengaged states of a predetermined meshing clutch among a plurality of dog clutches 50. The predetermined meshing clutch, or predetermined dog clutch, is a dog clutch 50 that is switched from the engaged state to the disengaged state by the gear shift of the transmission 20, and a dog clutch 50 that is switched from the disengaged state to the engaged state by the gear shift of the transmission 20. For example, in gear shifting between the 1st gear stage 1st and the 2nd gear stage 2nd, the predetermined dog clutch is the 1st gear dog clutch 50e that is involved in the formation of the 1st gear stage 1st, and the predetermined dog clutch is the 2nd gear dog clutch 50a that is involved in the formation of the 2nd gear stage 2nd. The same applies to gear shifting between other gear stages.

[0032] Figure 2 is a diagram illustrating the control functions and control systems for various control functions in the vehicle 10. In Figure 2, the vehicle 10 is further equipped with an electronic control unit 90, which acts as a controller for the vehicle 10, including control devices related to the control of the engine 12 and the transmission 20. The electronic control unit 90 is composed of a so-called microcomputer, for example, equipped with a CPU, RAM, ROM, input / output interface, etc. The CPU performs various controls on the vehicle 10 by performing signal processing according to a program pre-stored in ROM while utilizing the temporary storage function of RAM.

[0033] The electronic control unit 90 is supplied with various signals based on detection values ​​from various sensors installed in the vehicle 10. These sensors include, for example, an engine speed sensor 70, an input speed sensor 72, an output speed sensor 74, an accelerator pedal position sensor 76, and a barrel angle sensor 78. The signals include, for example, engine speed Ne, input speed Ni, output speed No, accelerator pedal position θacc, and barrel rotation angle θbrl. Output speed No is the rotational speed corresponding to the vehicle speed V. Barrel rotation angle θbrl is the rotation angle of the shift barrel 64.

[0034] Vehicle 10 is further equipped with paddle switches 82 fixed to a steering wheel 80 provided on the vehicle 10. The paddle switches 82 are input devices that accept manual gear shifting operations. Manual gear shifting operations include, for example, upshift operations that request an upshift of the transmission 20, and downshift operations that request a downshift of the transmission 20. For this reason, the paddle switches 82 include an upshift switch 82u that accepts upshift operations and a downshift switch 82d that accepts downshift operations. Whenever the upshift switch 82u is operated, the electronic control unit 90 is supplied with an upshift request signal Sup to request an upshift of the transmission 20. Whenever the downshift switch 82d is operated, the electronic control unit 90 is supplied with a downshift request signal Sdw to request a downshift of the transmission 20.

[0035] Vehicle 10 is further equipped with a neutral switch 84. The neutral switch 84 is an input device that accepts manual gear shifting operations to set the transmission 20 to neutral. The neutral state of the transmission 20 is a state in which none of the gears of the transmission 20 are engaged, and the power transmission state of the transmission 20 is set to a state where power transmission is impossible. The transmission 20 is set to neutral when all of the dog clutches 50 are released. The electronic control unit 90 is supplied with a neutral request signal Sn to request the transmission 20 to be set to neutral each time the neutral switch 84 is operated.

[0036] The electronic control unit 90 outputs various command signals to each device installed in the vehicle 10. These devices include, for example, the engine 12, the hydraulic control circuit 28, and the shift actuator 66. The various command signals include, for example, the engine control command signal Se, the K1 hydraulic control command signal Sk1, and the barrel control command signal Sbrl.

[0037] The electronic control unit 90 includes a power source control unit 92 and a clutch control unit 94 in order to implement various controls in the vehicle 10.

[0038] The power source control unit 92 calculates the required drive torque Trdem by applying, for example, the accelerator opening θacc and the vehicle speed V to a predetermined drive request map. The power source control unit 92 outputs an engine control command signal Se to obtain the engine torque Te that realizes the required drive torque Trdem, taking into consideration the gear ratio γ of the transmission 20.

[0039] The clutch control unit 94 switches the gears of the transmission 20, including the neutral state, based on the driver's upshift or downshift request received via the paddle switch 82, or the driver's neutral status received via the neutral switch 84. Alternatively, the clutch control unit 94 may make a gear shift decision for the transmission 20 using, for example, a predetermined gear shift map, and switch the gears of the transmission 20 as needed.

[0040] When the clutch control unit 94 receives an upshift request signal Sup while a gear is formed in the transmission 20, it outputs a barrel control command signal Sbrl to the shift actuator 66 to rotate the shift barrel 64 in the upshift direction and upshift the transmission 20. As a result, for example, in an upshift from the 1st gear (1st) to the 2nd gear (2nd), the 1st gear dog clutch 50e is switched from the engaged state to the disengaged state, and the 2nd gear dog clutch 50a is switched from the disengaged state to the engaged state. Note that the upshift request signal Sup is disabled when the 6th gear (6th) is formed.

[0041] When the clutch control unit 94 receives a downshift request signal Sdw while a gear is being formed, it outputs a barrel control command signal Sbrl to the shift actuator 66 to rotate the shift barrel 64 in the downshift direction and downshift the transmission 20. As a result, for example, in a downshift from the 2nd gear (2nd) to the 1st gear (1st), the 2nd gear dog clutch 50a is switched from the engaged state to the disengaged state, and the 1st gear dog clutch 50e is switched from the disengaged state to the engaged state. Note that the downshift request signal Sdw is disabled when the 1st gear (1st) is being formed.

[0042] When the clutch control unit 94 receives a neutral request signal Sn while a gear is being formed, it outputs a barrel control command signal Sbrl to the shift actuator 66 to rotate the shift barrel 64 and put the transmission 20 into a neutral state. As a result, for example, when switching from the 1st gear (1st) to the neutral state, the 1st gear dog clutch 50e is switched from the engaged state to the disengaged state. The neutral request signal Sn is also a dog clutch release request signal that requests the dog clutch 50 to be switched to the disengaged state.

[0043] Incidentally, during driving when the power transmission path between the engine 12 and the drive wheels 14 is in a state where power transmission is possible, that is, during driving when the gears are formed in the transmission 20 with the K1 clutch 18 engaged, an input torque Tin is generated to the transmission 20. This is also true when the vehicle is decelerating with the accelerator off. During vehicle deceleration, an input torque Tin is generated that is a negative torque due to the effects of friction and inertia of the engine 12, etc. The input torque Tin to the transmission 20 is synonymous with the input torque Tin to the dog clutch 50. Since the input torque Tin affects the frictional force at the meshing part of the meshing teeth, the larger the input torque Tin, the greater the force required to disengage the meshing teeth. For this reason, when switching to the neutral state when a gear is formed, it is conceivable to first switch the K1 clutch 18 to the disengaged state, and then start switching the dog clutch 50 to the disengaged state. However, when the K1 clutch 18 is disengaged, the effects of friction and inertia upstream of the K1 clutch 18 (for example, on the engine 12 side) are eliminated, but the effects of friction and inertia upstream of the K1 clutch 18, such as on the input shaft 20i, remain. In that case, even when the K1 clutch 18 is disengaged, depending on the specifications of the vehicle 10, the input torque Tin may be increased, making it difficult to disengage the meshing teeth. For example, if the oil pump, alternator, air conditioner compressor, etc. are driven via the input shaft 20i, the friction and inertia of these will also affect the input torque Tin in addition to the friction and inertia of the input shaft 20i itself. If the input torque Tin is increased, it is necessary to wait until the vehicle speed V has sufficiently decreased during vehicle deceleration. Alternatively, if the input torque Tin is increased, it is necessary to increase the force applied by the shift mechanism 60 to disengage the meshing teeth in order to counteract the effect of frictional force at the meshing portion of the meshing teeth. These measures may lead to restrictions on the use of vehicle 10 or an increase in costs for vehicle 10. It is desirable to minimize the force applied by the shift mechanism 60 while making it easier to switch the dog clutch 50 to the disengaged state.

[0044] Here, it was found that during the transient state in which the K1 clutch 18 transitions from the engaged state to the disengaged state, there is a timing when the input torque Tin is smaller than when the K1 clutch 18 is in the disengaged state. This is thought to be due to the large fluctuation in the input torque Tin during the transient state in which the K1 clutch 18 transitions from the engaged state to the disengaged state.

[0045] Therefore, the clutch control unit 94 first starts switching the dog clutch 50 to the released state, and then starts switching the K1 clutch 18 to the released state. This makes it easier for the dog clutch 50 to be switched to the released state, even in specifications where the friction and inertia on the input shaft 20i are large, so that the dog clutch 50 cannot be switched to the released state even if the switching to the dog clutch 50 to the released state is started after the K1 clutch 18 has been released. While the input torque Tin is fluctuating greatly, a timing occurs in which the force to switch the dog clutch 50 to the released state overcomes the input torque Tin, making it easier for the dog clutch 50 to be switched to the released state. Because the force to switch the dog clutch 50 to the released state is reliably applied while the input torque Tin is fluctuating during the process of the K1 clutch 18 moving from the engaged state to the released state, the K1 clutch 18 is switched to the released state after the force to switch the dog clutch 50 to the released state is applied first.

[0046] The clutch control unit 94 determines whether a switch to the released state of the dog clutch 50 has been requested while the power transmission path between the engine 12 and the drive wheels 14 is in a power transmission-enabled state. Driving while the power transmission path between the engine 12 and the drive wheels 14 is in a power transmission-enabled state means, for example, when the vehicle is decelerating with the accelerator off, and the power transmission path between the engine 12 and the drive wheels 14 is in a power transmission-enabled state. A request to switch to the released state of the dog clutch 50 has been requested means that a switch to the neutral state of the transmission 20, in which no gears are engaged, has been requested. The clutch control unit 94 determines whether a switch to the released state of the dog clutch 50 has been requested based on, for example, whether a request to shift from the 1st gear to the neutral state has been made. The clutch control unit 94 determines whether a request to shift from the 1st gear to the neutral state has been made based on whether or not a neutral request signal Sn has been received when the 1st gear is engaged.

[0047] If the clutch control unit 94 determines that a switch to the disengaged state of the dog clutch 50 is required while the vehicle is decelerating, it drives the shift mechanism 60 to apply the force necessary to disengage the meshing teeth of the dog clutch 50. The clutch control unit 94 drives the shift mechanism 60 to operate the switching mechanism 36, which acts as a dog clutch release actuator to switch the dog clutch 50 to the disengaged state. After starting to drive the shift mechanism 60, the clutch control unit 94 switches the K1 clutch 18 to the disengaged state.

[0048] The drive of the shift mechanism 60, which occurs before the K1 clutch 18 is switched to the disengaged state, is intended to apply the force necessary to disengage the meshing teeth in the dog clutch 50. Whether or not the dog clutch 50 is switched to the disengaged state as a result of applying the necessary force is irrelevant. After the necessary force is applied, the switching of the K1 clutch 18 to the disengaged state begins, and as a result of the process of the K1 clutch 18 moving from the engaged state to the disengaged state, the dog clutch 50 is switched to the disengaged state.

[0049] Therefore, when the force necessary to disengage the meshing teeth in the dog clutch 50 is applied, the switching to the disengaged state of the K1 clutch 18 may begin while ensuring that the necessary force for disengagement is reliably applied.

[0050] The clutch control unit 94 starts switching the K1 clutch 18 to the released state after a predetermined time TMf has elapsed from the time the shift mechanism 60 is started to drive. The predetermined time TMf is a predetermined elapsed time from the start of the drive of the shift mechanism 60, such as the time at which it is determined that the force necessary to release the meshing teeth in the dog clutch 50 has been reliably applied.

[0051] Alternatively, the clutch control unit 94 starts switching the K1 clutch 18 to the released state after the meshing teeth of the dog clutch 50 have moved relative to each other by a predetermined amount LTf or more, before disengaging. The predetermined amount LTf is, for example, a predetermined threshold for detecting slight relative movement (movement) between the meshing teeth of the dog clutch 50 before disengaging. The predetermined amount LTf is, for example, a predetermined relative movement amount at which it is determined that the force necessary to disengage the meshing teeth of the dog clutch 50 is reliably applied by the drive of the shift mechanism 60. The relative movement between the meshing teeth of the dog clutch 50 is detected, for example, by the barrel rotation angle θbrl detected by the barrel angle sensor 78, or by a signal from a sensor that detects the amount of movement of the switching mechanism 36 in the direction of the rotation axis CL1.

[0052] Figure 3 is a flowchart illustrating the main part of the control operation of the electronic control device 90, and is a flowchart illustrating the control operation to facilitate switching the dog clutch 50 to the released state when switching to the released state of the dog clutch 50 is required, and is repeatedly executed, for example, during vehicle deceleration driving when the power transmission path between the engine 12 and the drive wheels 14 is in a state where power transmission is possible.

[0053] In Figure 3, each step in the flowchart corresponds to a function of the clutch control unit 94. In step S10 (the step will be omitted hereafter), it is determined whether or not a switch to the released state of the dog clutch 50 is requested. If the determination in S10 is negative, the routine is terminated. If the determination in S10 is positive, in S20, the shift mechanism 60 is driven to apply the force necessary to release the meshing teeth of the dog clutch 50. Next, in S30, the K1 clutch 18 is switched to the released state. As a result, the dog clutch 50 is switched to the released state in the process of S20 or S30, and the routine is terminated.

[0054] As described above, according to this embodiment, when a switch to the disengaged state of the dog clutch 50 is requested during driving while the power transmission path between the engine 12 and the drive wheels 14 is in a power transmission state, the shift mechanism 60 is driven to apply the force necessary to disengage the meshing teeth of the dog clutch 50, and thereafter the K1 clutch 18 is switched to the disengaged state. As a result, even when the input torque Tin is large, the meshing teeth of the dog clutch 50 are more easily disengaged, even when the force necessary to disengage the meshing teeth of the dog clutch 50 is applied after the K1 clutch 18 has been disengaged.Therefore, when a switch to the disengaged state of the dog clutch 50 is requested, the dog clutch 50 can be easily switched to the disengaged state.

[0055] Furthermore, according to this embodiment, the switching to the released state of the K1 clutch 18 is initiated after a predetermined time TMf has elapsed from the time the shift mechanism 60 is started to drive, or after the meshing teeth of the dog clutch 50 have moved relative to each other by a predetermined amount LTf or more before disengaging due to the drive of the shift mechanism 60. As a result, the switching to the released state of the K1 clutch 18 is initiated while the force necessary to disengage the meshing teeth of the dog clutch 50 is reliably applied.

[0056] Furthermore, according to this embodiment, the period during which the power transmission path between the engine 12 and the drive wheels 14 is in a state where power transmission is possible is during vehicle deceleration with the accelerator off. This makes it easier to switch the dog clutch 50 to the released state when it is required to switch the dog clutch 50 to the released state during vehicle deceleration.

[0057] Furthermore, according to this embodiment, the request to switch the dog clutch 50 to the disengaged state is made when the request to switch the transmission 20, which has no gears engaged, to the neutral state is made. This makes it easier to switch the dog clutch 50 to the disengaged state when the request to switch the transmission 20 to the neutral state is made.

[0058] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other embodiments.

[0059] For example, in the above embodiment, an electric motor may be used as the power source in addition to or instead of the engine 12.

[0060] Furthermore, in the above-described embodiment, the transmission may be any transmission in which the gear stage is automatically switched by switching between the engaged and disengaged states of the meshing clutch. Alternatively, the transmission may include a friction clutch.

[0061] Furthermore, in the above-described embodiment, the gear shift request, including the neutral state, is not limited to manual gear shifting via the paddle switch 82 or the neutral switch 84. In short, the present invention can be applied to a control device of a vehicle equipped with a meshing clutch and a friction clutch provided in the power transmission path between the power source and the meshing clutch, when a switch to the disengaged state of the meshing clutch is requested during driving while the power transmission path between the power source and the drive wheels is in a power transmission-enabled state. In this invention, it is sufficient to switch the meshing clutch to the disengaged state, and the operation of disengaging the friction clutch is merely to assist in this process. After the meshing clutch has been switched to the disengaged state, the friction clutch does not need to maintain the disengaged state.

[0062] Furthermore, in the above-described embodiment, the power source for the actuator that switches between the engaged and disengaged states of the meshing clutch can be various, such as pneumatic, hydraulic, or electric motor.

[0063] It should be noted that the above-described embodiment is merely one example, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of Symbols]

[0064] 10: Vehicle 12: Engine (power source) 14: Drive wheels 18: K1 clutch (friction clutch) 20: Transmission 38: Switching mesh teeth (meshing teeth) 40: Gear-side mesh teeth (meshing teeth) 50: Dog clutch (meshing clutch) 60: Shift mechanism (actuator) 90: Electronic control unit (control unit) 94: Clutch control unit

Claims

1. A control device for a vehicle comprising: a meshing clutch provided in the power transmission path between a power source and a drive wheel, which is engaged by the meshing of meshing teeth and released when the meshing is released; an actuator for switching between the engaged and released states of the meshing clutch; and a friction clutch provided in the power transmission path between the power source and the meshing clutch, A vehicle control device characterized by including a clutch control unit that, when a switch to the disengaged state of the meshing clutch is required during driving in a state in which the power transmission path between the power source and the drive wheel is in a power transmission state, drives the actuator to apply the force necessary to disengage the meshing clutch, and then switches the friction clutch to the disengaged state.

2. The vehicle control device according to claim 1, characterized in that the clutch control unit starts switching to the release state of the friction clutch after a predetermined time has elapsed from the time the actuator is started to drive.

3. The vehicle control device according to claim 1, characterized in that the clutch control unit starts switching to the release state of the friction clutch after the meshing teeth in the meshing clutch have moved relative to each other by a predetermined amount or more by the drive of the actuator, before the meshing is released.

4. The vehicle control device according to claim 1, characterized in that the power transmission path between the power source and the drive wheel is in a state where power transmission is possible during driving when the vehicle is decelerating with the accelerator off.

5. The vehicle further includes a transmission in which the gear stage is automatically switched by the actuator switching between the engaged and disengaged states of a predetermined clutch among a plurality of engagement clutches. The vehicle control device according to any one of claims 1 to 4, characterized in that the case in which switching to the disengaged state of the engagement clutch is required is a case in which switching to the neutral state of the transmission in which none of the gear stages are formed is required.

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