Clutch control method for vehicle and clutch control device for vehicle

Abstract

The clutch control method of the vehicle 1 is used in a vehicle 1 having: a second clutch mechanism 21; and a second clutch position sensor 52 that detects engagement of the second clutch mechanism 21. The clutch control method of the vehicle 1 includes the steps of: in a case where the size of the differential rotation of the second clutch mechanism 21 is less than or equal to a first prescribed value Al, performing engagement of the second clutch mechanism 21; and in a case where the second clutch position sensor 52 is faulty, determining engagement of the second clutch mechanism 21 on the basis of the differential rotation, on the basis of the target value of the differential rotation at the time of rotation synchronization being set to a second prescribed value A2, that is, on the basis of the first prescribed value Al being offset to the larger side.

Description

TECHNICAL FIELD

[0001] The present application relates to clutch control of a vehicle. BACKGROUND

[0002] In JP 2015-028359 A, a technique is disclosed in which a sleeve position of an engagement clutch is detected with a stroke sensor. SUMMARY

[0003] In a case where the sleeve position of the engagement clutch is identified with the sensor, if the sensor malfunctions, the position of the sleeve cannot be grasped. As a result, it can be impossible to determine engagement or disengagement of the engagement clutch, and engagement control or disengagement control of the engagement clutch cannot be completed.

[0004] The present application has been made in view of such a problem, and aims to enable determination of engagement or disengagement of the engagement clutch even when the sensor malfunctions.

[0005] A clutch control method of a vehicle according to an aspect of the present application is a clutch control method of a vehicle having: an engagement clutch; and an engagement sensor that detects engagement of the engagement clutch, including the steps of: performing engagement of the engagement clutch in a case where a differential rotation of the engagement clutch is smaller than or equal to a prescribed value; and in a case where the engagement sensor malfunctions, shifting the prescribed value to the larger side, and on this basis, determining engagement of the engagement clutch based on the differential rotation.

[0006] A clutch control method of a vehicle according to another aspect of the present application is a clutch control method of a vehicle having: an engagement clutch; a shift mechanism that transmits a clutch operating force to the engagement clutch without via a spring; and a disengagement sensor that detects disengagement of the engagement clutch, including the steps of: performing disengagement of the engagement clutch based on the shift mechanism by reducing a transmission torque of the engagement clutch; in a case where the disengagement sensor malfunctions, determining disengagement of the engagement clutch based on a differential rotation of the engagement clutch; and in a case where the disengagement sensor malfunctions, reducing the transmission torque that is reduced when disengagement of the engagement clutch is performed, to a value having an absolute value greater than that in a case where the disengagement sensor is normal.

[0007] Yet another other mode of the clutch control method of the vehicle of the present application is a clutch control method of a vehicle having an engaging clutch, a shift mechanism that transmits a clutch operating force to the engaging clutch via a spring, and a disengagement sensor that detects disengagement of the engaging clutch, including the steps of executing disengagement of the engaging clutch based on the shift mechanism with a transmission torque of the engaging clutch reduced, determining disengagement of the engaging clutch based on differential rotation of the engaging clutch when the disengagement sensor fails, and increasing an absolute value of the transmission torque when the disengagement sensor fails in a case where the differential rotation does not change to an absolute value greater than a prescribed value even if a prescribed time elapses.

[0008] According to yet another other mode of the present application, a clutch control device of a vehicle corresponding to each of the above-described clutch control methods of the vehicle is provided. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic configuration view of the vehicle.

[0010] Figure 2 is a view showing a power transmission state in a series hybrid mode.

[0011] Figure 3 is a view showing a power transmission state in an internal combustion engine direct connection mode.

[0012] Figure 4 is a view showing an operation region of the vehicle.

[0013] Figure 5 is a view showing the 1st shift mechanism.

[0014] Figure 6 is a view showing the 2nd shift mechanism.

[0015] Figure 7 is a view showing one example of engagement control in a flowchart.

[0016] Figure 8A is a first view of an explanatory view of a target value of clutch differential rotation.

[0017] Figure 8B is a second view of the explanatory view of the target value of clutch differential rotation.

[0018] Figure 9 is a view showing one example of a timing chart corresponding to Figure 7

[0019] Figure 10 is a view showing one example of control of the 2nd embodiment in a flowchart.

[0020] ​Figure 11 is a flowchart showing a part of the processing shown in FIG. 6. Figure 10

[0021] Figure 12 is a view showing a first shift mechanism of the third embodiment.

[0022] Figure 13 is a view showing a second shift mechanism of the third embodiment.

[0023] Figure 14 is a view showing one example of the control of the third embodiment in a flowchart.

[0024] Figure 15 is a view showing one example of a timing chart corresponding to the processing shown in FIG. 6. Figure 14

[0025] Figure 16 is a view showing one example of the control of the modified example in a flowchart.

[0026] Figure 17 is a view showing one example of the control of the fourth embodiment in a flowchart.

[0027] Figure 18 is a view showing one example of a timing chart corresponding to the processing shown in FIG. 6. Figure 17

[0028] Figure 19 is a view showing one example of the control of the first modified example in a flowchart. DETAILED DESCRIPTION

[0029] Hereinafter, an embodiment of the present application will be described with reference to the accompanying drawings.

[0030] (First Embodiment)

[0031] Figure 1 is a schematic configuration view of a vehicle 1. The vehicle 1 has an internal combustion engine 3, a power generation motor 4, a battery 5, a traveling motor 2, and a controller 7.

[0032] The internal combustion engine 3 can be any one of a gasoline engine or a diesel engine.

[0033] The power generation motor 4 is driven by the power of the internal combustion engine 3 to generate electricity. In addition, the power generation motor 4 also has a function of motoring the internal combustion engine 3 by power running using the electric power of the battery 5 described later.

[0034] The electric power generated by the power generation motor 4, and the electric power regenerated by the traveling motor 2 described later charge the battery 5.

[0035] ​​​The running motor 2 is driven by the electric power of the battery 5 to drive the drive wheels 6. In addition, the running motor 2 has a so-called regenerative function of regenerating the regenerative energy as electric power in association with the rotation of the drive wheels 6 at the time of deceleration or the like.

[0036] The controller 7 performs control of the running motor 2, the internal combustion engine 3, and the power generation motor 4.

[0037] Further, the controller 7 is constituted by a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The controller 7 can also be constituted by a plurality of microcomputers.

[0038] In addition, the vehicle 1 has a power transmission path 24 that transmits power between the running motor 2 and the drive wheels 6, a power transmission path 25 that transmits power between the internal combustion engine 3 and the drive wheels 6, and a power transmission path 26 that transmits power between the internal combustion engine 3 and the power generation motor 4.

[0039] The power transmission path 24 is constituted by a first reduction gear 8 provided to a rotation shaft 2A of the running motor 2, a second reduction gear 9 engaged with the first reduction gear 8, a differential gear 12 provided to a differential case 11, and a third reduction gear 10 provided coaxially with the second reduction gear 9 to be engaged with the differential gear 12. In addition, the first clutch mechanism 19 that switches between a state in which the first reduction gear 8 is relatively rotatable with respect to the rotation shaft 2A and a state in which the first reduction gear 8 is not relatively rotatable is provided to the power transmission path 24. The first clutch mechanism 19 is a so-called dog clutch constituted by a first sleeve 20 supported to the rotation shaft 2A in a manner that is slidable in the axial direction and an engagement portion 8A provided to the first reduction gear 8. That is, the first sleeve 20 is moved in the direction of the first reduction gear 8 to be provided to a plurality of protrusions of the first sleeve 20 in a manner that protrudes in the direction of the engagement portion 8A and a plurality of protrusions of the engagement portion 8A in a manner that protrude in the direction of the first sleeve 20 are engaged in a state in which they are disposed in different directions in the rotation direction. The first sleeve 20 is moved in the opposite direction of the first reduction gear 8 from this state to eliminate the engagement of the protrusions of both, thereby forming a disengaged state. Further, the first sleeve 20 is moved by an electric actuator.

[0040] If the first clutch mechanism 19 is in the engaged state, the power of the running motor 2 is transmitted to the drive wheels 6. On the other hand, if the first clutch mechanism 19 is in the disengaged state, the rotation of the rotation shaft 2A of the running motor 2 is not transmitted to the first reduction gear 8, so the power transmission from the running motor 2 to the drive wheels 6 is cut off.

[0041] The power transmission path 25 is composed of the 4th reduction gear 16 provided to the output shaft 3A of the internal combustion engine 3, the 5th reduction gear 17 engaged with the 4th reduction gear 16, the differential gear 12 provided to the differential case 11, and the 6th reduction gear 18 provided coaxially with the 5th reduction gear 17 to be engaged with the differential gear 12. Further, the 2nd clutch mechanism 21 that switches between a state where the 4th reduction gear 16 is relatively rotatable with respect to the output shaft 3A and a state where the 4th reduction gear 16 is not relatively rotatable is provided to the power transmission path 25. The 2nd clutch mechanism 21 is a so-called dog clutch composed of the 2nd sleeve 22 supported to the output shaft 3A in a manner so as to be slidable in the axial direction and the engagement portion 16A provided to the 4th reduction gear 16. That is, the 2nd sleeve 22 is moved in the direction of the 4th reduction gear 16 to be provided to the plurality of projections of the 2nd sleeve 22 in a manner so as to project in the direction of the engagement portion 16A and the plurality of projections of the engagement portion 16A provided in a manner so as to project in the direction of the 2nd sleeve 22 are engaged by being disposed in the rotational direction so as to be different from each other to be in the engaged state. The 2nd sleeve 22 is moved in the opposite direction of the 4th reduction gear 16 from this state to eliminate the engagement of the projections of both to be in the disengaged state. Further, the 2nd sleeve 22 is moved by the electric actuator.

[0042] If the 2nd clutch mechanism 21 is in the engaged state, the power of the internal combustion engine 3 is transmitted to the drive wheels 6. In the following description, this state is also referred to as the internal combustion engine direct connection state. On the other hand, if the 2nd clutch mechanism 21 is in the disengaged state, the rotation of the output shaft 3A of the internal combustion engine 3 is not transmitted to the 4th reduction gear 16, and thus the power transmission from the internal combustion engine 3 to the drive wheels 6 is cut off.

[0043] The power transmission path 26 is composed of the 7th reduction gear 13 provided to the output shaft 3A of the internal combustion engine 3, the 8th reduction gear 14 engaged with the 7th reduction gear 13, and the 9th reduction gear 15 provided to the rotation shaft 4A of the motor generator 4. The power transmission path 26 does not have an element that cuts off the power transmission. That is, the power transmission path 26 is always in the state of transmitting the power.

[0044] Both the 1st clutch mechanism 19 and the 2nd clutch mechanism 21 are engagement clutches, and the engaged and disengaged operations of the 1st clutch mechanism 19 and the 2nd clutch mechanism 21 are controlled by the controller 7. Various signals are input to the controller 7. The various signals include, for example, signals from rotation speed sensors that respectively detect the rotation speeds of the 1st sleeve 20 of the 1st clutch mechanism 19, the 1st reduction gear 8, the 2nd sleeve 22 of the 2nd clutch mechanism 21, and the 4th reduction gear 16. The above-mentioned rotation speeds are used to detect the differential rotation of the 1st clutch mechanism 19 and the 2nd clutch mechanism 21.

[0045] In addition, a state of charge SOC of the battery 5 indicating a charge amount of the battery 5 is input from the battery 5 to the controller 7. Further, signals from an accelerator opening sensor detecting an accelerator opening amount indicating a depression amount of an accelerator pedal of the vehicle 1, a vehicle speed sensor detecting a vehicle speed VSP, the first clutch position sensor 51, the second clutch position sensor 52, and the like are input to the controller 7.

[0046] In the present embodiment, a rotational speed N ICE of the internal combustion engine 3 constitutes a rotational speed of the first sleeve 20, and a rotational speed N MG of the traveling motor 2 constitutes a rotational speed of the second sleeve 22. A rotational speed of the first reduction gear 8 and a rotational speed of the fourth reduction gear 16 constitute an output side rotational speed N OUT that rotates together with the drive wheels 6. The output side rotational speed N OUT can be calculated, for example, based on a signal from the vehicle speed sensor and using a gear ratio.

[0047] The vehicle 1 of the above-described structure is capable of switching between a series hybrid mode in which power is transmitted to the drive wheels 6 by the power transmission path 24 to travel, and an internal combustion engine direct connection mode in which the internal combustion engine is formed in a direct connection state and power is transmitted to the drive wheels 6 by the power transmission path 25 to travel. In the series hybrid mode, the drive wheels 6 are driven by the traveling motor 2 using electric power of the power generator motor 4 that generates electric power by being driven by the power of the internal combustion engine 3. The controller 7 switches between the series hybrid mode and the internal combustion engine direct connection mode according to an operating state, specifically, according to the vehicle speed VSP and the vehicle drive power DP.

[0048] Figure 2 is a view indicating a power transmission state in the series hybrid mode. In the series hybrid mode, power is transmitted to the drive wheels 6 by the power transmission path 24. That is, in the series hybrid mode, the first clutch mechanism 19 is brought into an engaged state, whereby power generated by the traveling motor 2 is transmitted to the drive wheels 6. At this time, the second clutch mechanism 21 is brought into a disengaged state.

[0049] Further, in the series hybrid mode, power of the internal combustion engine 3 is also transmitted to the power generator motor 4 via the power transmission path 26, and the power generator motor 4 generates electric power, and the electric power obtained by the generation is used to charge the battery 5. However, whether or not the power generator motor 4 generates electric power is specified according to a charge amount of the battery 5, and in a case where the battery 5 does not need to be charged, the internal combustion engine 3 is stopped.

[0050] Figure 3is a view indicating the power transmission state in the engine direct connection mode. In the engine direct connection mode, power is transmitted to the drive wheels 6 using the power transmission path 25. That is, in the engine direct connection mode, the 2nd clutch mechanism 21 is in the engaged state, whereby power generated by the engine 3 is transmitted to the drive wheels 6.

[0051] In the engine direct connection mode, the 1st clutch mechanism 19 is in the disengaged state. If the 1st clutch mechanism 19 is brought into the engaged state in the engine direct connection mode, the traveling motor 2 is rotated by the rotation of the drive wheels 6 to generate an induced electromotive force. In the case where there is a margin in the charge capacity of the battery 5, the generated power is used to charge the battery 5 to regenerate energy. However, in the case where there is no margin in the charge capacity of the battery 5, the generated resistance becomes a frictional force that hinders the rotation of the drive wheels 6, and becomes a factor of the deterioration of the fuel consumption performance. In contrast, in the present embodiment, the 1st clutch mechanism 19 is in the disengaged state in the engine direct connection mode, and thus the deterioration of the fuel consumption performance due to the rotation of the traveling motor 2 by the rotation of the drive wheels 6 can be suppressed.

[0052] Figure 4 is a view indicating the operation region of the vehicle 1. The region R1 is a series hybrid mode region, and is set in such a manner that, in a low speed region, the upper limit value of the vehicle driving force DP is constant, and in a medium to high speed region, the higher the vehicle speed VSP, the smaller the upper limit value of the vehicle driving force DP. The region R2 is an engine direct connection mode region, and is set as a region where the vehicle speed VSP is higher than a prescribed vehicle speed VSP1 and the vehicle driving force DP is smaller than a prescribed driving force DP1. The prescribed vehicle speed VSP1 is set in the medium to high speed region, and the prescribed driving force DP1 is set to be lower than the upper limit value of the vehicle driving force DP in the region R1. The reason for setting the region R2 in this manner is as follows.

[0053] That is, in the series hybrid mode, the engine 3 can be operated and the power generation motor 4 can be driven to generate power at an operation point where the fuel consumption is good, and thus a higher fuel consumption performance can be obtained. On the other hand, when the requested driving force is reduced during high speed traveling, as a result, the operation point of the engine 3 approaches the operation point where the fuel consumption is good. In this case, if the electric conversion efficiency is taken into account, the system efficiency is reversed in the series hybrid mode and the engine direct connection mode.

[0054] A time lag is provided at the boundary line between the region R1 and the region R2. Therefore, after the operation mode is switched from the series hybrid mode to the engine direct connection mode in the acceleration state, even if the vehicle 1 is immediately decelerated, the operation mode is not immediately switched to the series hybrid mode. Similarly, after the operation mode is switched from the engine direct connection mode to the series hybrid mode in the deceleration state, even if the vehicle 1 is immediately accelerated, the operation mode is not immediately switched to the engine direct connection mode.

[0055] Next, the shift mechanism that the vehicle 1 has will be described.

[0056] Figure 5 is a view that shows the first shift mechanism 30, Figure 6 is a view that shows the second shift mechanism 40. The vehicle 1 has the first shift mechanism 30 and the second shift mechanism 40.

[0057] The first shift mechanism 30 is a mechanism for performing engagement and disengagement of the first clutch mechanism 19, and has a first shift actuator 31, a first shift cam 32, a first pin 33, a first spring 34, and a first shift fork 35. The first shift mechanism 30 transmits clutch working force in the engagement direction and the disengagement direction to the first clutch mechanism 19 with power of the first shift actuator 31 as the clutch working force.

[0058] The second shift mechanism 40 is a mechanism for performing engagement and disengagement of the second clutch mechanism 21, and has a second shift actuator 41, a second shift cam 42, a second pin 43, a second spring 44, and a second shift fork 45. The second shift mechanism 40 transmits clutch working force in the engagement direction and the disengagement direction to the second clutch mechanism 21 with power of the second shift actuator 41 as the clutch working force.

[0059] The first shift mechanism 30 and the second shift mechanism 40 have the same configuration as each other. Therefore, hereinafter, the first shift mechanism 30 will be described as an example.

[0060] The first shift actuator 31 drives the first shift cam 32. The first shift actuator 31 is constituted by, for example, an electric motor, and rotationally drives the first shift cam 32. The first shift cam 32 has a first guide groove 321. The first pin 33 is engaged with the first guide groove 321. The first guide groove 321 guides the first pin 33 when the first shift cam 32 rotates, thereby moving the first pin 33 in the axial direction of the first shift cam 32. The axial direction of the first shift cam 32 is set to the axial direction of the rotation shaft 2A on which the first sleeve 20 is provided, that is, the direction along the working direction of the first clutch mechanism 19.

[0061] The first pin 33 is connected to the first shift fork 35 via the first spring 34. The first spring 34 is provided between the first shift cam 32 and the first shift fork 35 on a power transmission path that links the first shift actuator 31 and the first shift fork 35. For the first spring 34, a spring that can travel by a length required for the first shift fork 35 to move from the disengagement position to the engagement position is used.

[0062] The first shift fork 35 engages with the first sleeve 20 of the first clutch mechanism 19. The outer peripheral groove of the first sleeve 20 engages with the first shift fork 35 in a manner capable of sliding in the rotational direction. The first sleeve 20 moves in the operating direction of the first clutch mechanism 19, that is, in the direction in which the first clutch mechanism 19 is engaged and in the direction in which the first clutch mechanism 19 is disengaged, by the clutch operating force transmitted from the first shift fork 35.

[0063] The first clutch position sensor 51 is provided to the first shift mechanism 30, and the second clutch position sensor 52 is provided to the second shift mechanism 40. The first clutch position sensor 51 detects the axial position of the first sleeve 20, and the second clutch position sensor 52 detects the axial position of the second sleeve 22.

[0064] The detected portion of the first clutch position sensor 51 is provided to the power transmission site between the first spring 34 and the first shift fork 35, that is, to the site that moves in the axial direction integrally with the first sleeve 20. Similarly, the detected portion of the second clutch position sensor 52 is provided to the site that moves in the axial direction integrally with the second sleeve 22.

[0065] A stroke sensor can be used for the first clutch position sensor 51, for example. In this case, the first clutch position sensor 51 is configured to detect the axial position of the detected portion to detect the engagement position of the first sleeve 20. The same applies to the second clutch position sensor 52.

[0066] The first clutch position sensor 51 functions as an engagement sensor to detect the engagement position of the first sleeve 20 and functions as a disengagement sensor to detect the disengagement position of the first sleeve 20. The first clutch position sensor 51 as the engagement sensor and the disengagement sensor can be a sensor other than a stroke sensor and can be configured by a plurality of sensors. The same applies to the second clutch position sensor 52.

[0067] When engagement of the second clutch mechanism 21 is performed, the controller 7 recognizes the position of the second sleeve 22 by the second clutch position sensor 52. In this case, if the second clutch position sensor 52 malfunctions, the position of the second sleeve 22 cannot be grasped. As a result, it can be impossible to determine engagement of the second clutch mechanism 21, and thus it can be impossible to complete engagement control of the second clutch mechanism 21. The same applies to the first clutch mechanism 19.

[0068] In view of this, in the present embodiment, the controller 7 performs the clutch engagement control described next.

[0069] Figure 7is a diagram showing an example of engagement control by the controller 7. Hereinafter, the second clutch mechanism 21 will be described as an example of the engagement clutch, and the first clutch mechanism 19 will be described as appropriate.

[0070] In step S1, the controller 7 determines whether or not the clutch engagement has started. Here, the second clutch mechanism 21 is engaged in a case where the operation mode is shifted from the series hybrid mode to the direct connection mode of the internal combustion engine.

[0071] Therefore, in step S1, it is determined that the engagement has started in a case where the operation point of the vehicle 1 is moved from the region Rl to the region R2. In the case of the first clutch mechanism 19, it is possible to determine that the engagement has started in a case where the operation point of the vehicle 1 is shifted from the region R2 to the region Rl. If it is determined that NO in step S1, the process is temporarily ended, and if it is determined that YES in step S1, the process proceeds to step S2.

[0072] In step S2, the controller 7 determines whether or not the position sensor is normal. The abnormality of the second clutch position sensor 52 is a sensor abnormality in which the engagement position and the disengagement position of the second sleeve 22 cannot be properly detected, including a wire breakage and the like. It is also possible to determine the presence or absence of the abnormality of the second clutch position sensor 52 using an appropriate technique other than the known technique. If it is determined that YES in step S2, the process proceeds to step S3.

[0073] In step S3, the controller 7 sets the target value of the clutch differential rotation at the time of rotation synchronization to the first prescribed value Al. The first prescribed value Al is a target value in a case where the second clutch position sensor 52 is normal, and is set in advance.

[0074] In step S4, the controller 7 performs clutch rotation synchronization. The motor for power generation 4 is controlled so that the rotation of the second sleeve 22 approaches the rotation of the fourth reduction gear 16, and thus the rotation synchronization of the second clutch mechanism 21 is performed. Thus, the magnitude (absolute value) of the differential rotation of the second clutch mechanism 21 gradually decreases. In the case of the first clutch mechanism 19, the motor for traveling 2 is controlled so that the rotation of the first sleeve 20 approaches the rotation of the first reduction gear 8, and thus the rotation synchronization can be performed.

[0075] In step S4, the controller 7 further performs clutch engagement instruction. In step S4, in a case where the magnitude of the differential rotation of the second clutch mechanism 21 is smaller than or equal to the first prescribed value Al during a predetermined determination time, the clutch engagement instruction of the second clutch mechanism 21 is performed, and thus the engagement of the second clutch mechanism 21 is started.

[0076] In step S5, the controller 7 determines whether the clutch sleeve is in the engaged position. In step S5, the clutch engagement determination of the second clutch mechanism 21 is performed based on the normal output of the second clutch position sensor 52.

[0077] If the determination in step S5 is negative, it is determined that the second clutch mechanism 21 is not engaged, and the process returns to step S5. If the determination in step S5 is positive, it is determined that the second clutch mechanism 21 is engaged, and the process proceeds to step S6.

[0078] In step S6, the controller 7 completes the clutch engagement control. In step S6, for example, the flag indicating whether the clutch is engaged is set to ON, thereby completing the engagement control of the second clutch mechanism 21. When the operating mode changes between series hybrid mode and direct internal combustion engine mode, if the clutch engagement control is completed, the replacement of torque between the driving motor 2 and the internal combustion engine 3 begins. After step S6, the process temporarily ends.

[0079] If the determination in step S2 is negative, the process proceeds to step S7. In step S7, the controller 7 sets the target value of the clutch differential rotation during rotational synchronization to a second predetermined value A2. The second predetermined value A2 is set as follows.

[0080] Figure 8A , Figure 8B This is a diagram illustrating the target value of the clutch differential rotation. Figure 8A This indicates the condition when the position sensor is functioning normally. Figure 8B This indicates the situation when the position sensor malfunctions. The following explanation uses the second clutch position sensor 52 as an example; the same applies to the first clutch position sensor 51.

[0081] like Figure 8A As shown, when the second clutch position sensor 52 is functioning normally, the target value for differential rotation during rotational synchronization is set to a first predetermined value A1. On the other hand, the detected differential rotation, based on the output from the second clutch position sensor 52, has a measurement deviation α centered on the target differential rotation. The measurement deviation α is mainly caused by rotational variations. Therefore, the measurement deviation α is set to the measurement deviation after clutch engagement, i.e., after the engagement of the second clutch mechanism 21. As a result, the detected differential rotation when the actual differential rotation is the first predetermined value A1 has a lower limit value A1-α.

[0082] The first prescribed value Al is set in such a manner that the lower limit value Al - a is not less than or equal to zero, which is the differential rotation after the second clutch mechanism 21 is engaged. Therefore, the clutch engagement is started before the differential rotation becomes zero. Thus, even if tooth overlap occurs in which the pawls of the second clutch mechanism 21 interfere with each other after the engagement is started, the tooth overlap is eliminated due to the phase shift in the rotational directions of the pawls from each other, and thus the clutch engagement is performed again.

[0083] The first prescribed value Al is set in such a manner that the magnitude of the lower limit value Al - a is smaller than the magnitude of the measurement deviation a. Therefore, in this case, overlap occurs in the range in which the differential rotation is detected before and after the clutch engagement. As a result, it is possible that the differential rotation detected before and after the clutch engagement does not change.

[0084] In the case where the second clutch position sensor 52 is normal, the engagement of the second clutch mechanism 21 is determined using the second clutch position sensor 52. Therefore, in this case, even if the differential rotation detected before and after the clutch engagement does not change, the engagement of the second clutch mechanism 21 can be determined.

[0085] In the case where the second clutch position sensor 52 is abnormal, the engagement of the second clutch mechanism 21 cannot be determined using the second clutch position sensor 52. In addition, in the case where the target value of the differential rotation at the time of the rotational synchronization is the first prescribed value Al, it is possible that the differential rotation detected before and after the clutch engagement does not change. Therefore, in this case, if the clutch engagement is to be determined based on the differential rotation, it is possible that the clutch is erroneously determined to be engaged although the clutch is not actually engaged.

[0086] In the present embodiment, in the case where the second clutch position sensor 52 is abnormal, the engagement of the second clutch mechanism 21 is determined based on the differential rotation on the basis that the target value of the differential rotation at the time of the rotational synchronization is set to the second prescribed value A2 as shown in FIG. 6. Figure 8B

[0087] The second prescribed value A2 is set in such a manner that the lower limit value A2 - a of the differential rotation detected in the case where the actual differential rotation is the second prescribed value A2 is larger than the measurement deviation a. The second prescribed value A2 corresponds to a value in which the first prescribed value Al is shifted to the larger side, and is set to a value in which the first prescribed value Al is shifted to a value larger than the variation width 2a of the differential rotation.

[0088] In this case, overlap does not occur in the range in which the differential rotation is detected before and after the clutch engagement. Therefore, the differential rotation detected before and after the clutch engagement is different, and thus the engagement of the second clutch mechanism 21 can be determined based on the differential rotation.

[0089] ​A second predetermined value A2 is preset within the range of differential rotation that enables the second clutch mechanism 21 to engage, based on experiments, etc. This is because, in cases where the differential rotation is too large, the second clutch mechanism 21 may sometimes fail to engage. The specific values ​​of the first predetermined value A1 and the second predetermined value A2 may differ in the first clutch mechanism 19 and the second clutch mechanism 21.

[0090] Return to Figure 7 In step S8A, the controller 7 synchronizes the rotation of the second clutch mechanism 21. The generator motor 4 is controlled so that the rotation of the second sleeve 22 approaches the rotation of the fourth reduction gear 16, thereby synchronizing the rotation of the second clutch mechanism 21. In step S8A, if the magnitude of the differential rotation of the second clutch mechanism 21 is less than or equal to a second predetermined value A2 within a preset determination time period, the controller 7 further instructs the second clutch mechanism 21 to engage. Thus, engagement of the second clutch mechanism 21 begins.

[0091] In step S9, the controller 7 determines whether the magnitude of the differential rotation is less than or equal to a predetermined value D1. The differential rotation after clutch engagement is zero; therefore, in step S9, in other words, it determines whether the difference between the current differential rotation and the differential rotation after clutch engagement is less than or equal to the predetermined value D1. The predetermined value D1 is a preset value used to determine whether the clutch is engaged.

[0092] If the determination in step S9 is negative, it is determined that the second clutch mechanism 21 is not engaged, and the process returns to step S9. If the determination in step S9 is positive, it is determined that the second clutch mechanism 21 is engaged. In this case, the process proceeds to step S6, and the controller 7 completes the clutch engagement control of the second clutch mechanism 21.

[0093] Figure 9 It means and Figure 7 The flowchart shown is an example of a timing diagram corresponding to this one. Figure 9 The section explains the operation mode switching control from series hybrid mode to direct internal combustion engine mode.

[0094] The operation mode switching control includes a rotation synchronization phase, a clutch engagement phase, a torque replacement phase, and a clutch disengagement phase. During the rotation synchronization phase, rotational synchronization of the engaged clutch is performed. During the clutch engagement phase, clutch engagement control is performed. During the torque replacement phase, torque is replaced between the torque T_MG of the driving motor 2 and the torque T_SUM of the internal combustion engine 3 and the generator motor 4 to replace the drive torque of the vehicle 1. During the clutch disengagement phase, clutch disengagement control is performed.

[0095] At timing Tl, the operation point of the vehicle 1 moves from the region Rl to the region R2. Therefore, in order to change the operation mode from the series hybrid mode to the direct connection mode of the internal combustion engine, a change request of the operation mode is generated as shown by a broken line. Further, the rotational synchronization of the 2nd clutch mechanism 21 is started in accordance with the change request of the operation mode.

[0096] Therefore, the rotational speed N_ICE of the internal combustion engine 3 approaches the 2nd output side rotational speed N_OUT2 due to the increase of the torque T_GEN of the motor generator 4. The 2nd output side rotational speed N_OUT2 is the rotational speed of the 4th reduction gear 16. Therefore, from the timing Tl, the rotation of the 2nd sleeve 22 approaches the rotation of the 4th reduction gear 16.

[0097] The transmission torque of the 2nd clutch mechanism 21 is the sum of the torque T_ICE of the internal combustion engine 3 and the torque T_GEN of the motor generator 4, that is, the torque T_SUM, and if the torque T_GEN becomes zero thereafter, the torque T_ICE indicates the torque T_SUM. At this time, in order to maintain the rotational speed N_ICE as a constant rotational speed, the control of the fine adjustment using the torque T_GEN can be performed.

[0098] At timing T2, the differential rotation of the 2nd clutch mechanism 21, that is, the differential rotation between the 2nd output side rotational speed N_OUT2 and the rotational speed N_ICE is smaller than or equal to the 2nd prescribed value A2. The size of the differential rotation is maintained to be smaller than or equal to the 2nd prescribed value A2 until the timing T3 at which the determination time elapses. Therefore, at the timing T3, the clutch engagement is started, and the 2nd pin 43 and the 2nd sleeve 22 start to move to the engagement side.

[0099] At timing T4, the gear overlap occurs in the 2nd clutch mechanism 21 to hinder the movement of the 2nd sleeve 22. Therefore, even if the 2nd pin 43 moves from the timing T4, the 2nd sleeve 22 does not move, and the 2nd spring 44 is compressed.

[0100] The 2nd pin 43 moves to the engagement position at timing T5, but the gear overlap is not removed at the timing T5, and is removed thereafter at timing T6. If the gear overlap is removed, the 2nd sleeve 22 starts to move to the engagement side by the elastic force of the 2nd spring 44, and reaches the engagement position at timing T7. As a result, the size of the differential rotation of the 2nd clutch mechanism 21 is smaller than or equal to the prescribed value Dl, and the clutch engagement is completed.

[0101] Thus, in the present embodiment, in the case where the size of the differential rotation of the 2nd clutch mechanism 21 is smaller than or equal to the 2nd prescribed value A2, the engagement of the 2nd clutch mechanism 21 is performed. Further, the range of the detected differential rotation at this time is as shown by a hatched area in FIG. 10. Figure 8BThe range of detection of differential rotation after the clutch is not engaged as described above does not overlap. Therefore, in the present embodiment, until the magnitude of differential rotation of the second clutch mechanism 21 at timing T7 becomes less than or equal to the prescribed value Dl, it is not erroneously determined that the second clutch mechanism 21 has been engaged.

[0102] The following describes timing T7 onward.

[0103] From timing T7, disengagement of the first clutch mechanism 19 is started in correspondence with completion of engagement control of the clutch of the second clutch mechanism 21, and the first pin 33 starts to move to the disengagement side. At this time, the torque T_MG of the traveling motor 2 is still acting on the first clutch mechanism 19. The torque T_MG causes the first clutch mechanism 19 to generate disengagement resistance that hinders the first sleeve 20 from moving to the disengagement side.

[0104] Therefore, even if the first pin 33 moves from the engagement position to the disengagement position between timing T7 and timing T8, the first sleeve 20 does not move as indicated by the dashed line, and at this time, the first spring 34 is elongated.

[0105] From timing T7, torque replacement of the drive torque of the vehicle 1 from the torque T_MG of the traveling motor 2 to the torque T_SUM is performed. In the torque replacement, reduction of the transmission torque of the first clutch mechanism 19 and increase of the transmission torque of the second clutch mechanism 21 are simultaneously performed.

[0106] The torque T_MG constitutes the transmission torque of the first clutch mechanism 19, and the torque T_SUM constitutes the transmission torque of the second clutch mechanism 21 as described above. Therefore, from timing T7, the torque T_MG starts to decrease, and on the other hand, the torque T_SUM starts to increase. At this time, the torque T_SUM increases basically due to the increase of the torque T_ICE, and the fine adjustment of the torque T_SUM is borne by the power generation motor 4. At this time, the torque T_SUM can be increased using only the torque T_GEN.

[0107] At timing T9, the elastic force of the first spring 34 exceeds the disengagement resistance as the torque T_MG decreases. Therefore, from timing T9, the first sleeve 20 starts to move to the disengagement side using the elastic force of the first spring 34. The period between timing T8 and timing T9 is the waiting time of the first sleeve 20 from the time when the first pin 33 moves to the disengagement position until the time when the first sleeve 20 starts to move.

[0108] The replacement of the torque is completed at timing T10, and if the first sleeve 20 is moved to the disengagement position at timing T11, the clutch engagement control of the first clutch mechanism 19 is completed. As a result, the shift of the operation mode is completed. From timing T11, the power is not transmitted from the internal combustion engine 3 to the first sleeve 20 via the first reduction gear 8. Therefore, the rotational speed N_MG of the travel motor 2 rotating together with the first sleeve 20 starts to decrease. The period between timing T9 and timing T11 is the disengagement time of the first sleeve 20 until the first sleeve 20 is moved from the engagement position to the disengagement position.

[0109] Next, the main effects of the present embodiment will be described.

[0110] The clutch control method of the vehicle 1 according to the present embodiment is used in a vehicle 1 that has: the second clutch mechanism 21 that is one example of an engagement clutch; and the second clutch position sensor 52 that detects the engagement of the second clutch mechanism 21. The clutch control method of the vehicle 1 includes the steps of: in a case where the differential rotation of the second clutch mechanism 21 is smaller than or equal to the first prescribed value Al, performing the engagement of the second clutch mechanism 21; and in a case where the second clutch position sensor 52 is malfunctioning, setting the target value of the differential rotation at the time of the rotational synchronization to the second prescribed value A2, i.e., shifting the first prescribed value Al to the larger side, and on the basis of the differential rotation, determining the engagement of the second clutch mechanism 21.

[0111] According to this method, in a case where the second clutch position sensor 52 is malfunctioning, the engagement determination of the second clutch mechanism 21 can be performed, and thus the operation mode to be achieved can be shifted. As a result, it is possible to prevent the decrease in the fuel consumption and the power performance of the vehicle 1.

[0112] In the present embodiment, the first prescribed value Al is shifted to a value that is larger than the variation width 2a of the differential rotation after the engagement of the second clutch mechanism 21. In other words, the second prescribed value A2 is set to a value that is larger than the variation width 2a of the differential rotation after the engagement of the second clutch mechanism 21.

[0113] According to this method, it is possible to make the differential rotation different before and after the engagement of the clutch, and thus the engagement determination of the second clutch mechanism 21 can be accurately performed.

[0114] In a case where the malfunction of the first clutch position sensor 51 is determined during the travel in the internal combustion engine direct connection mode, the operation mode is shifted to the series hybrid mode, and thus it is possible to prevent the misfire of the internal combustion engine 3 and avoid the situation where the vehicle 1 cannot travel. Therefore, in a case where the first clutch position sensor 51 is malfunctioning, it is necessary to complete the clutch engagement control of the first clutch mechanism 19.

[0115] The clutch control method of vehicle 1 can also be used to engage the first clutch mechanism 19, which is an example of a meshing clutch. Therefore, if a malfunction of the first clutch position sensor 51 is detected during operation in the direct-drive mode of the internal combustion engine, the clutch engagement control of the first clutch mechanism 19 can be completed to switch the operating mode to series hybrid mode. As a result, the internal combustion engine 3 can be prevented from stalling and the vehicle 1 can be prevented from becoming inoperable.

[0116] (Second Implementation)

[0117] In this embodiment, the controller 7 is configured to further perform the control described below. Hereinafter, the second clutch mechanism 21 will be used as an example of an engaging clutch, but the same applies to the first clutch mechanism 19.

[0118] Figure 10 This is a flowchart illustrating an example of the control performed by controller 7 in this embodiment. Figure 11 It means Figure 10 The diagram shows the subprocess of step S8B. Besides replacing step S8A, step S8B is also included. Figure 10 The flowchart shown is Figure 7 The flowcharts shown are the same. In this embodiment, in Figure 11 The subprocess shown includes step S8B, which involves the implementation of clutch rotation synchronization and clutch engagement indication.

[0119] like Figure 11 As shown, in step S81, the controller 7 determines whether the vehicle 1 is accelerating. For example, it can determine whether the vehicle 1 is accelerating based on the output of the vehicle speed sensor. If the determination is positive in step S81, the process proceeds to step S82.

[0120] In step S82, the controller 7 determines whether the rotational speed N_ICE of the internal combustion engine 3 is higher than the rotational speed N_OUT2 of the second output side.

[0121] Here, in the power transmission path 25 via the second clutch mechanism 21, the second sleeve 22 is located on the upstream side of the internal combustion engine 3, which is closer to the fourth reduction gear 16. Therefore, the second sleeve 22 corresponds to the upstream engagement element of the power transmission path 25, and the fourth reduction gear 16 corresponds to the downstream engagement element of the power transmission path 25.

[0122] When the rotational speed of the upstream-side engagement element is higher than the rotational speed of the downstream-side engagement element in the power transmission path 25, the direction in which the rotational speed of the downstream-side engagement element can vary at the time of engagement of the second clutch mechanism 21 is the acceleration direction, which coincides with the acceleration state of the vehicle 1.

[0123] Therefore, when the determination in step S82 is affirmative, the process proceeds to step S84, and the controller 7 performs clutch rotation synchronization and clutch engagement instruction of the second clutch mechanism 21.

[0124] In this case, the rotational speed N ICE is controlled in the decreasing direction in the clutch rotation synchronization, so that the rotational speed N ICE can approach the second output-side rotational speed N OUT2. The clutch engagement instruction is performed when the magnitude of the differential rotation of the second clutch mechanism 21 is smaller than or equal to the second prescribed value A2 during the determination time. After step S84, the process is temporarily ended.

[0125] When the rotational speed of the upstream-side engagement element is lower than the rotational speed of the downstream-side engagement element, the direction in which the rotational speed of the downstream-side engagement element can vary at the time of engagement of the second clutch mechanism 21 is the deceleration direction, which does not coincide with the acceleration state of the vehicle 1. As a result, at the time of engagement of the second clutch mechanism 21, it is possible that the behavior of the vehicle 1 changes to give the driver a sense of disharmony.

[0126] Therefore, when the determination in step S82 is negative, the process proceeds to step S83, and the controller 7 controls the motor generator 4 so that the rotational speed N ICE is higher than the second output-side rotational speed N OUT2. Thus, at the time of engagement of the second clutch mechanism 21, the driver is less likely to feel a change in the behavior of the vehicle 1.

[0127] In step S83, the rotational speed N ICE can be made higher than the second output-side rotational speed N OUT2 by a prescribed value set in advance. After step S83, the process proceeds to step S84, and clutch rotation synchronization and clutch engagement instruction of the second clutch mechanism 21 are performed, as in the case where the determination in step S82 is affirmative.

[0128] When the determination in step S81 is negative, it is determined that the deceleration state, and the process proceeds to step S85. In step S85, the controller 7 determines whether the rotational speed N ICE is lower than the second output-side rotational speed N OUT2.

[0129] When the rotational speed of the upstream-side engagement element is lower than the rotational speed of the downstream-side engagement element in the power transmission path 25, the direction in which the rotational speed of the downstream-side engagement element can vary at the time of engagement of the second clutch mechanism 21 is the deceleration direction, which coincides with the deceleration state of the vehicle 1.

[0130] Therefore, in the case where the determination in step S85 is negative, the process proceeds to step S84, and clutch rotation synchronization and clutch engagement instruction of the second clutch mechanism 21 are performed.

[0131] In this case, in the clutch rotation synchronization, the rotational speed N ICE is controlled in the increasing direction, whereby the rotational speed N ICE can be brought close to the second output side rotational speed N OUT2. The clutch engagement instruction is performed in the case where the magnitude of the differential rotation of the second clutch mechanism 21 is smaller than or equal to the second prescribed value A2 during the determination time.

[0132] In the case where the rotational speed of the upstream side engagement element is higher than the rotational speed of the downstream side engagement element, the direction in which the rotational speed of the downstream side engagement element can vary at the time of engagement of the second clutch mechanism 21 is the accelerating direction, which is inconsistent with the decelerating state of the vehicle 1. As a result, at the time of engagement of the second clutch mechanism 21, it is possible that the behavior of the vehicle 1 changes to give the driver a sense of disharmony.

[0133] Therefore, in the case where the determination in step S85 is negative, the process proceeds to step S86, and the controller 7 controls the internal combustion engine 3 so that the rotational speed N ICE is lower than the second output side rotational speed N OUT2. Thereby, at the time of engagement of the second clutch mechanism 21, the driver is less likely to feel a change in the behavior of the vehicle 1.

[0134] The rotational speed N ICE can be made lower than the second output side rotational speed N OUT2 by a prescribed value set in advance in step S86. After step S86, the process proceeds to step S84. In this case, clutch rotation synchronization and clutch engagement instruction of the second clutch mechanism 21 are performed in the same manner as in the case where the determination in step S85 is positive.

[0135] Next, the main effects of the present embodiment will be described.

[0136] In the present embodiment, in the acceleration of the vehicle 1, engagement of the second clutch mechanism 21 is performed in the case where the rotational speed N ICE on the power transmission path 25 via the second clutch mechanism 21, which corresponds to the rotational speed of the second sleeve 22, is greater than the rotational speed of the fourth reduction gear 16, that is, the second output side rotational speed N OUT2. In addition, in the deceleration of the vehicle 1, engagement of the second clutch mechanism 21 is performed in the case where the rotational speed N ICE is smaller than the second output side rotational speed N OUT2 on the power transmission path 25 via the second clutch mechanism 21.

[0137] According to this method, it is possible to avoid a situation in which the acceleration of the vehicle 1 becomes negative when the second clutch mechanism 21 is engaged in acceleration, and a situation in which the acceleration of the vehicle 1 becomes positive when the second clutch mechanism 21 is engaged in deceleration. Therefore, it is possible to make the driver less likely to feel a change in the behavior of the vehicle 1 when the second clutch mechanism 21 is engaged in acceleration and deceleration of the vehicle 1.

[0138] (Third Embodiment)

[0139] The present embodiment is the same as the first embodiment except for the point that the first shift mechanism 30 and the second shift mechanism 40 are configured in the following manner with the controller 7. The same change can also be applied to the second embodiment.

[0140] Figure 12 is a view that shows the first shift mechanism 30 of the present embodiment. Figure 13 is a view that shows the second shift mechanism 40 of the present embodiment. In the present embodiment, the first shift mechanism 30 does not have the first spring 34, and the second shift mechanism 40 does not have the second spring 44. Therefore, the first shift mechanism 30 is configured to transmit the clutch operating force to the first clutch mechanism 19 without passing through a spring (a spring including the first spring 34), and the second shift mechanism 40 is configured to transmit the clutch operating force to the second clutch mechanism 21 without passing through a spring (a spring including the second spring 44).

[0141] In the present embodiment, the controller 7 performs the following control when the meshing clutch is disengaged. Hereinafter, the second clutch mechanism 21 is described as an example of the meshing clutch, and the same applies to the first clutch mechanism 19.

[0142] Figure 14 is a view that shows one example of the control performed by the controller 7 in the present embodiment in a flowchart. In step Sll, the controller 7 determines whether or not the torque replacement phase has started. If the clutch engagement phase is completed, the torque replacement phase starts. Therefore, in step Sll, determination can be made, for example, on the basis of a flag that indicates whether or not the second clutch mechanism 21 has been engaged. If the determination in step Sll is affirmative, the processing proceeds to step S12.

[0143] In step S12, the controller 7 determines whether or not the second clutch position sensor 52 is normal. If the determination in step S12 is affirmative, the processing proceeds to step S13.

[0144] In step S13, the controller 7 starts replacement of the torque. Here, in the 2nd clutch mechanism 21, the transmitted torque is decreased so that the disengagement resistance that hinders movement of the 2nd sleeve 22 to the disengagement side is reduced, and disengagement of the 2nd clutch mechanism 21 can be achieved. Therefore, in the replacement of the torque, the transmitted torque, i.e., the torque T_SUM, of the 2nd clutch mechanism 21 is decreased to a target value of zero, under the condition that the 2nd clutch position sensor 52 is normal.

[0145] In step S14, the controller 7 determines whether or not the replacement of the torque has ended. For example, it can be determined whether or not the replacement of the torque has ended depending on whether or not the torque T_SUM becomes the target value. If it is determined as negative in step S14, the process returns to step S14. If it is determined as affirmative in step S14, the process proceeds to step S15.

[0146] In step S15, the controller 7 performs clutch disengagement instruction of the 2nd clutch mechanism 21. Thereby, on the basis that the transmitted torque of the 2nd clutch mechanism 21 is decreased, the 2nd shift actuator 41 is driven to the disengagement direction of the 2nd clutch mechanism 21. As a result, the clutch operating force in the disengagement direction is transmitted to the 2nd sleeve 22 by the 2nd shift mechanism 40.

[0147] In step S16, the controller 7 determines whether or not the 2nd sleeve 22 is in the disengagement position. In step S16, clutch disengagement determination of the 2nd clutch mechanism 21 is performed on the basis of the output of the normal 2nd clutch position sensor 52. If it is determined as negative in step S16, the process returns to step S16, and if it is determined as affirmative in step S16, the process proceeds to step S17.

[0148] In step S17, the controller 7 completes clutch disengagement control of the 2nd clutch mechanism 21. In step S17, for example, a flag indicating whether or not the clutch has been disengaged can be set to ON. After step S17, the process is temporarily ended.

[0149] In the case where it is determined as negative in step S12, the process proceeds to step S18A, and the controller 7 determines whether or not the rotational speed N_ICE is increased after the clutch of the 2nd clutch mechanism 21 is disengaged. After the 2nd clutch mechanism 21 is disengaged, the operation mode becomes the series hybrid mode, and the power generation operation is performed in the internal combustion engine 3. Therefore, in step S18A, in other words, it is determined whether or not the rotational speed N_ICE is increased due to the power generation operation after the 2nd clutch mechanism 21 is disengaged.

[0150] In the power generation operation of the internal combustion engine 3, a requested power generation power as a request for power that should be generated is calculated based on the state of charge SOC of the battery, the vehicle speed VSP, the accelerator opening degree, and the requested value of the vehicle driving force DP. In addition, the target value of the rotational speed N ICE is set based on the requested power generation power. Therefore, in step S18A, a determination can be made based on the requested power generation power or the target value of the rotational speed N ICE. The internal combustion engine 3 and the power generation motor 4 constitute a generator. The rotational speed N ICE corresponds to the rotational speed of the generator. If the determination is affirmative in step S18A, the process proceeds to step S19, and if the determination is negative in step S18A, the process proceeds to step S20.

[0151] In step S19, the controller 7 sets the target value of the transmission torque of the second clutch mechanism 21 to be reduced to a prescribed value T SUM1 and starts the replacement of the torque. The prescribed value T SUM1 is a value greater than zero and is set in advance.

[0152] Thus, in the case where the rotational speed N ICE increases after the second clutch mechanism 21 is disengaged, the target value of the transmission torque of the second clutch mechanism 21 is set to the positive side. Therefore, in the case where the rotational speed N ICE is higher after the disengagement than at the time when the second clutch mechanism 21 starts to be disengaged, the transmission torque of the second clutch mechanism 21 to be reduced is reduced to the negative side.

[0153] In step S20, the controller 7 sets the target value of the transmission torque of the second clutch mechanism 21 to be reduced to a negative value of the prescribed value T SUM1 and starts the replacement of the torque.

[0154] Thus, in the case where the rotational speed N ICE decreases after the second clutch mechanism 21 is disengaged, the target value of the transmission torque of the second clutch mechanism 21 to be reduced is set to the negative side. Therefore, in the case where the rotational speed N ICE is lower after the disengagement than at the time when the second clutch mechanism 21 starts to be disengaged, the transmission torque of the second clutch mechanism 21 to be reduced is reduced to the negative side.

[0155] As described above, when the second clutch position sensor 52 is normal, the target value of the transmission torque of the second clutch mechanism 21 is set to zero. Therefore, in steps S19 and S20, the transmission torque of the second clutch mechanism 21 to be reduced is reduced to a value having an absolute value greater than that when the second clutch position sensor 52 is normal. In other words, at this time, the target value of the transmission torque of the second clutch mechanism 21 to be reduced is set to a value having an absolute value greater than that when the second clutch position sensor 52 is normal. The target value of the transmission torque of the second clutch mechanism 21 to be reduced can be set so that the disengagement resistance of the second clutch mechanism 21 has an absolute value greater than that when the second clutch position sensor 52 is normal in a range lower than the clutch operating force in the disengagement direction.

[0156] After the step S19, the step S20, the process proceeds to a step S21. In the step S21, it is determined whether or not the replacement of the torque has been completed, and if the determination is negative, the process returns to the step S21, and if the determination is affirmative, the process proceeds to a step S22. In the step S22, the clutch disengagement instruction of the second clutch mechanism 21 is performed as in the step S15.

[0157] In the step S23, the controller 7 determines whether or not the magnitude of the differential rotation of the second clutch mechanism 21 is greater than or equal to a prescribed value D2. In the step S23, the disengagement determination of the second clutch mechanism 21 is performed on the basis of the differential rotation of the second clutch mechanism 21. The differential rotation before the clutch disengagement is zero, and thus, in the step S23, in other words, it is determined whether or not the magnitude of the difference between the current differential rotation and the differential rotation before the clutch disengagement is greater than or equal to the prescribed value D2.

[0158] The prescribed value D2 is a determination value for determining whether or not the clutch has been disengaged, and is set to a value greater than the variation amplitude 2a of the differential rotation. In this case, no overlap is generated in the range in which the differential rotation is detected before and after the clutch disengagement. Thus, the detected differential rotation is different before and after the clutch disengagement, and thus, it is possible to determine whether or not the second clutch mechanism 21 has been disengaged on the basis of the differential rotation.

[0159] If the determination is negative in the step S23, the process returns to the step S23. If the determination is affirmative in the step S23, it is determined that the second clutch mechanism 21 has been disengaged. In this case, the process proceeds to the step S17, and the clutch disengagement control of the second clutch mechanism 21 is completed.

[0160] The reason why the disengagement control of the second clutch mechanism 21 is thus completed also when the second clutch position sensor 52 fails is as follows.

[0161] That is, in the case where the failure of the second clutch position sensor 52 is determined during the travel in the engine direct connection mode, the operation mode is changed to the series hybrid mode, and thus, it is possible to prevent the engine 3 from being stalled and to avoid the vehicle 1 from being unable to travel. Also, for this reason, it is necessary to complete the clutch disengagement control of the second clutch mechanism 21 in the case where the second clutch position sensor 52 fails.

[0162] Figure 15 is a graph showing one example of a time chart corresponding to the flowchart shown in Figure 14 The graph is a graph showing one example of a time chart corresponding to the flowchart shown in

[0163] At timing Tll, rotation synchronization of the first clutch mechanism 19 is started in accordance with the shift request of the operation mode. As a result, the torque T_MG of the travel motor 2 is increased, and the rotational speed N_MG approaches the first output-side rotational speed N_OUT1. The first output-side rotational speed N_OUT1 is the rotational speed of the first reduction gear 8. Therefore, the rotation of the first sleeve 20 approaches the rotation of the first reduction gear 8 from timing Tll.

[0164] At timing T12, the differential rotation of the first clutch mechanism 19, that is, the differential rotation between the first output-side rotational speed N_OUT1 and the rotational speed N_MG is smaller than or equal to the second prescribed value A2, and remains smaller than or equal to the second prescribed value A2 until timing T13, which is the timing at which the determination time elapses. Therefore, the clutch engagement of the first clutch mechanism 19 is started at timing T13, and the first pin 33 and the first sleeve 20 start to move toward the engagement side.

[0165] At timing T14, the tooth overlap occurs in the first clutch mechanism 19, and the movement of the first sleeve 20 is obstructed. In the present embodiment, the first spring 34 is not provided to the first shift mechanism 30, and therefore the movement of the first pin 33 also stops at timing T14.

[0166] The tooth overlap is removed at timing T15. As a result, the first sleeve 20 and the first pin 33 again start to move toward the engagement side, and reach the engagement position at timing T16. Thus, the differential rotation of the first clutch mechanism 19 is smaller than or equal to the prescribed value Dl, and the clutch engagement control of the first clutch mechanism 19 is completed.

[0167] In this way, if the engagement of the first clutch mechanism 19 is performed in a state where the differential rotation of the first clutch mechanism 19 is smaller than or equal to the second prescribed value A2, the range of the detected differential rotation at that time does not overlap with the range of the detected differential rotation after the clutch engagement. Therefore, in this case, until the differential rotation of the first clutch mechanism 19 is smaller than or equal to the prescribed value Dl at timing T16, it is not erroneously determined that the first clutch mechanism 19 is engaged.

[0168] From timing T16, the replacement of the torque is performed in correspondence with the completion of the clutch engagement control. In the replacement of the torque, the increase of the torque T_MG of the travel motor 2 and the decrease of the torque T_SUM are simultaneously performed. Thus, the drive torque of the vehicle 1 is gradually replaced from the torque T_SUM to the torque T_MG. The torque T_SUM is basically decreased due to the decrease of the torque T_ICE of the internal combustion engine 3.

[0169] The target value of the reduced torque T_SUM is set to the prescribed value T_SUM1 and the replacement of the torque is started. This is because, in this example, the rotational speed N_ICE after the 2nd clutch mechanism 21 is disengaged increases according to the motoring operation compared to when the 2nd clutch mechanism 21 starts to be disengaged. As a result, at the timing T17 at which the replacement of the torque ends, the torque T_SUM becomes the prescribed value T_SUM1.

[0170] At the timing T17, the clutch disengagement control of the 2nd clutch mechanism 21 is started in correspondence with the end of the replacement of the torque. In the present embodiment, the 2nd spring 44 is not provided to the 2nd shift mechanism 40, and therefore the clutch disengagement control is performed after the replacement of the torque ends and the transmission torque of the 2nd clutch mechanism 21 is reduced. As a result, from the timing T17, the 2nd pin 43 and the 2nd sleeve 22 are moved in the disengagement direction.

[0171] The 2nd pin 43 and the 2nd sleeve 22 reach the disengagement position at the timing T18. In the case where the 2nd clutch position sensor 52 is normal, the clutch disengagement control is completed when the 2nd sleeve 22 is in the disengagement position. Therefore, in this case, at the timing T18, the clutch disengagement control phase ends.

[0172] In this example, the rotational speed N_ICE after the 2nd clutch mechanism 21 is disengaged in the case where the 2nd clutch position sensor 52 is normal increases slowly as indicated by the dotted line due to the motoring operation. Also, in the case where the 2nd clutch position sensor 52 is normal, the target value of the torque T_SUM that is reduced in the replacement of the torque is set to zero.

[0173] In this case, after the 2nd clutch mechanism 21 is disengaged, the differential rotation of the 2nd clutch mechanism 21 does not sufficiently increase. As a result, in the case where the 2nd clutch position sensor 52 has failed, it is assumed that the disengagement of the 2nd clutch mechanism 21 cannot be properly determined using the differential rotation.

[0174] In the present embodiment, in the case where the 2nd clutch position sensor 52 is abnormal, the torque T_SUM that is reduced in the replacement of the torque becomes the prescribed value T_SUM1 as indicated by the timing T17. Therefore, if the 2nd clutch mechanism 21 is disengaged at the timing T18, the rotational speed N_ICE increases in correspondence with the torque T_SUM and the differential rotation of the 2nd clutch mechanism 21 increases. As a result, at the timing T19, the magnitude of the differential rotation of the 2nd clutch mechanism 21 becomes greater than or equal to the prescribed value D2, and it is possible to rapidly complete the clutch disengagement control after the timing T18.

[0175] In this example, the rotational speed N ICE increases after the 2nd clutch mechanism 21 is disengaged, and therefore the target value of the torque T SUM, which is reduced in the replacement of torque, is set to the positive side, that is, a value greater than zero. Thus, the change direction of the rotational speed N ICE, which changes based on the torque T SUM, is the same direction as the change direction of the rotational speed N ICE required in the power generation operation. Therefore, the rotational speed N ICE required in the power generation operation is achieved more quickly than in the case of the opposite direction.

[0176] Next, the main effects of the present embodiment will be described.

[0177] In the present embodiment, the clutch control method of the vehicle 1 is used in a vehicle 1 that has a 2nd clutch mechanism 21, a 2nd shift mechanism 40 that transmits a clutch operating force to the 2nd clutch mechanism 21 without passing through a spring, and a 2nd clutch position sensor 52 that detects disengagement of the 2nd clutch mechanism 21. The clutch control method of the vehicle 1 includes the steps of performing disengagement of the 2nd clutch mechanism 21 based on the 2nd shift mechanism 40 by reducing the transmission torque of the 2nd clutch mechanism 21, determining disengagement of the 2nd clutch mechanism 21 based on the differential rotation of the 2nd clutch mechanism 21 when the 2nd clutch position sensor 52 fails, and reducing the transmission torque of the 2nd clutch mechanism 21 that is reduced when disengagement of the 2nd clutch mechanism 21 is performed, that is, reducing the torque T SUM to a prescribed value T SUM1 when the 2nd clutch mechanism 21 fails, thereby reducing it to a value having an absolute value greater than when the 2nd clutch position sensor 52 is normal.

[0178] According to this method, the rotational speed N ICE changes when the 2nd clutch mechanism 21 is disengaged, causing the differential rotation of the 2nd clutch mechanism 21 to increase, and therefore disengagement of the 2nd clutch mechanism 21 can be reliably determined when the 2nd clutch position sensor 52 fails.

[0179] In the present embodiment, in the power transmission path 25 through the 2nd clutch mechanism 21, an internal combustion engine 3 and an electric power generator 4 that constitute a generator are provided at a position more upstream than the 2nd clutch mechanism 21. Regarding the torque T SUM that is reduced when disengagement of the 2nd clutch mechanism 21 is performed, it is reduced to the positive side when the rotational speed N ICE after disengagement is higher than when the 2nd clutch mechanism 21 starts to disengage, and it is reduced to the negative side when the rotational speed N ICE after disengagement is lower than when the 2nd clutch mechanism 21 starts to disengage.

[0180] According to this method, the rotational speed N ICE can be changed in the same direction as the direction in which the rotational speed N ICE changes when the second clutch mechanism 21 is disengaged in the generation operation. Therefore, the rotational speed N ICE after the second clutch mechanism 21 is disengaged can be rapidly changed to the rotational speed N ICE required in the generation operation, compared to the case where the rotational speed N ICE is changed in the opposite direction.

[0181] In the case where the first clutch position sensor 51 and the second clutch position sensor 52 simultaneously malfunction, the disengagement of the meshing clutch that is disengaged after the operation mode is switched can be determined after the engagement of the meshing clutch that is engaged after the operation mode is switched is determined.

[0182] Thus, the engagement and disengagement of the meshing clutch can be appropriately determined in the operation mode switching control, taking into account the case where the clutch disengagement phase comes after the clutch engagement phase. This is also true of the fourth embodiment described later.

[0183] The controller 7 can be configured in the following manner.

[0184] Figure 16 is a diagram that represents the control of the modified example of the embodiment in a flowchart. Except for the fact that step S18A is replaced with step S18B, Figure 16 the flowchart shown in Figure 15 is the same as the flowchart shown in

[0185] In step S18B, the controller 7 determines whether the vehicle 1 is in the acceleration state. Also, in the case of the acceleration state, the target value of the reduced transmission torque of the second clutch mechanism 21 is set to the prescribed value T SUM1 and the replacement of the torque is started (step S19), and in the case of the deceleration state, the target value of the reduced transmission torque of the second clutch mechanism 21 is set to the negative value of the prescribed value T SUM1 and the replacement of the torque is started (step S20).

[0186] In this case, when the series hybrid mode is switched, it is expected that the rotational speed N ICE required in the generation operation increases in the acceleration state and decreases in the deceleration state, and the target value of the reduced transmission torque of the second clutch mechanism 21 is set.

[0187] Therefore, in this method, the rotational speed N ICE can also be changed in the same direction as the change direction of the rotational speed N ICE required in the power generation operation when the 2nd clutch mechanism 21 is disengaged. As a result, the rotational speed N ICE after the 2nd clutch mechanism 21 is disengaged can be rapidly changed to the rotational speed N ICE required in the power generation operation. In addition, in the case where the 2nd clutch mechanism 21 is not yet disengaged, a change in the vehicle behavior can not be easily felt.

[0188] (4th Embodiment)

[0189] The present embodiment is the same as the 1st embodiment except that the controller 7 is configured in the following manner. Therefore, the 1st shift mechanism 30 has the 1st spring 34, and the 2nd shift mechanism 40 has the 2nd spring 44. The same change can also be applied to the 2nd embodiment.

[0190] In the present embodiment, the controller 7 performs the following control when the meshing clutch is disengaged. Hereinafter, the 2nd clutch mechanism 21 is described as an example of the meshing clutch, and the same applies to the 1st clutch mechanism 19.

[0191] Figure 17 is a diagram illustrating one example of the control performed by the controller 7 in the present embodiment. In step S31, the controller 7 determines whether or not the torque replacement phase has started. If the determination in step S31 is negative, the processing is temporarily ended, and if the determination in step S31 is affirmative, the processing proceeds to step S32.

[0192] In step S32, the controller 7 operates the 2nd shift actuator 41 until the disengagement position, and sets the target value of the transmission torque of the 2nd clutch mechanism 21 at the time of disengagement to the prescribed value T SUM2 to implement the replacement of the torque.

[0193] That is, in the present embodiment, the 2nd shift mechanism 40 has the 2nd spring 44, and therefore, when the 2nd clutch mechanism 21 is disengaged, it is not necessary to operate the 2nd shift actuator 41 after the transmission torque of the 2nd clutch mechanism 21 is sufficiently reduced. Therefore, in step S32, the operation of the 2nd shift actuator 41 is started at the same time as the start of the replacement of the torque.

[0194] The prescribed value T SUM2 is set to zero. This is because, if the transmission torque is applied to the 2nd clutch mechanism 21, a disengagement resistance occurs, and it can be impossible to disengage the 2nd clutch mechanism 21 by the elastic force of the 2nd spring 44. The prescribed value T SUM2 can be set to be greater than zero within a range in which the 2nd clutch mechanism 21 can be disengaged by the elastic force of the 2nd spring 44 against the disengagement resistance.

[0195] In step S33, the controller 7 determines whether the 2nd clutch position sensor 52 is normal. If affirmative in step S33, the process proceeds to step S34.

[0196] In step S34, the controller 7 determines whether the 2nd sleeve 22 is in the disengaged position. If negative in step S34, the process returns to step S34, and if affirmative in step S34, the process proceeds to step S35.

[0197] In step S35, the controller 7 completes the clutch disengagement control of the 2nd clutch mechanism 21. The process is temporarily ended after step S35.

[0198] In the case where the determination in step S33 is negative, the process proceeds to step S36. In this case, the controller 7 determines whether the magnitude of the differential rotation of the 2nd clutch mechanism 21 is less than or equal to a prescribed value D3 during a disengagement estimation time until the disengagement time elapses.

[0199] The disengagement estimation time is a disengagement estimation time of the 2nd clutch mechanism 21 from the start of the disengagement until the completion of the disengagement, and is set in advance on the basis of experiments or the like. For the disengagement estimation time, for example, a time greater than or equal to the disengagement time in the case where the disengagement of the 2nd clutch mechanism 21 is most time-consuming can be set. The disengagement estimation time corresponds to the prescribed time.

[0200] The prescribed value D3 is a value for determining the magnitude of the differential rotation within the disengagement estimation time, and is set to the measurement deviation a, for example. In this case, the differential rotation is zero during the period in which the 2nd clutch mechanism 21 is not disengaged, and thus the detection of the magnitude of the differential rotation being less than or equal to the measurement deviation a enables determination that the 2nd clutch mechanism 21 is not disengaged.

[0201] The prescribed value D3 can be set to be greater than the measurement deviation a. The prescribed value D3 can be set to be less than the prescribed value D2. Thus, if the magnitude of the differential rotation is less than or equal to the prescribed value D3 after the disengagement estimation time elapses, it can be determined that the 2nd clutch mechanism 21 is disengaged but the differential rotation is not easily increased due to the generation operation.

[0202] If affirmative in step S36, it is determined that the differential rotation of the 2nd clutch mechanism 21 is not changed to be greater than the prescribed value D3 in absolute value, and the process proceeds to step S37A.

[0203] In step S37A, the controller 7 determines whether the rotation speed N ICE is increasing. If affirmative in step S37A, the process proceeds to step S38, and if negative in step S37A, the process proceeds to step S39.

[0204] In step S38, the controller 7 sets the torque T_GEN of the power generation motor 4 to a prescribed value T_GEN1. The prescribed value T_GEN1 is a value greater than zero and is set in advance. Thus, in the case where the rotation speed N_ICE increases after the 2nd clutch mechanism 21 is disengaged, the transmission torque of the 2nd clutch mechanism 21, that is, the torque T_SUM, is set to the positive side.

[0205] In step S39, the controller 7 sets the torque T_GEN to a negative value of the prescribed value T_GEN1. Thus, in the case where the rotation speed N_ICE decreases after the 2nd clutch mechanism 21 is disengaged, the torque T_SUM is set to the negative side.

[0206] In steps S38 and S39, in the case where the differential rotation of the 2nd clutch mechanism 21 does not change to an absolute value greater than the prescribed value D3 even if the 2nd clutch mechanism 21 is disengaged, the absolute value of the torque T_SUM is increased. After steps S38 and S39, the process proceeds to step S40. In the case where the determination in step S36 is negative, the process also proceeds to step S40.

[0207] In step S40, the controller 7 determines whether the magnitude of the differential rotation of the 2nd clutch mechanism 21 is greater than or equal to the prescribed value D2. If the determination in step S40 is negative, the process returns to step S40, and if the determination in step S40 is affirmative, it is determined that the 2nd clutch mechanism 21 is disengaged, and the process proceeds to step S35. As a result, the clutch disengagement control of the 2nd clutch mechanism 21 is completed.

[0208] Figure 18 is a graph showing one example of a time chart corresponding to the flowchart shown in Figure 17 is a graph showing one example of a time chart corresponding to the flowchart shown in

[0209] The magnitude of the differential rotation of the 1st clutch mechanism 19 is less than or equal to the 2nd prescribed value A2 from the timing T22 until the timing T23 at which the determination time elapses. Therefore, the clutch of the 1st clutch mechanism 19 is engaged at the timing T23, and the 1st pin 33 and the 1st sleeve 20 start to move to the engagement side.

[0210] At the timing T24, the tooth overlap occurs in the 1st clutch mechanism 19, and the movement of the 1st sleeve 20 is obstructed. In the present embodiment, the 1st shift mechanism 30 has the 1st spring 34, and therefore the 1st pin 33 continues to move to the engagement side from the timing T24. The 1st pin 33 reaches the engagement position at the timing T25.

[0211] The tooth overlap is released at timing T26, whereby the first sleeve 20 again starts to move to the engaged side. The first sleeve 20 reaches the engaged position at timing T27. As a result, the magnitude of the differential rotation of the first clutch mechanism 19 is smaller than or equal to the prescribed value Dl, and the clutch engagement control is completed.

[0212] In this case, the engagement of the first clutch mechanism 19 is performed also in a case where the magnitude of the differential rotation of the first clutch mechanism 19 is smaller than or equal to the second prescribed value A2, and therefore the first clutch mechanism 19 is not erroneously determined to be engaged during the period from timing T23 to timing T27.

[0213] From timing T27, the replacement of the torque is started in correspondence with the completion of the clutch engagement control of the first clutch mechanism 19, and the operation of the second shift actuator 41 to the disengaged position is started so that the second pin 43 moves to the disengaged side. The torque T_SUM of the second sleeve 22 is sufficiently reduced until the elastic force of the second spring 44 can move the second sleeve 22 against the disengaging resistance. Therefore, the second sleeve 22 does not move as shown by the broken line from timing T27, and the engaged position is maintained unchanged.

[0214] At timing T28, the second pin 43 reaches the disengaged position. At timing T29, the torque T_SUM is sufficiently reduced, and the second spring 44 starts to move the second sleeve 22 to the disengaged side against the disengaging resistance. As a result, the second sleeve 22 moves to the disengaged side from timing T29. The replacement of the torque ends at timing T30.

[0215] At timing T31, the second sleeve 22 reaches the disengaged position. The period between timing T28 and timing T29 is the waiting time of the second sleeve 22, and the period between timing T29 and timing T31 is the disengaging time of the second sleeve 22. In this example, the disengaging estimated time elapses at timing T31.

[0216] The torque T_SUM shown by the broken line indicates a normal case of the second clutch position sensor 52. In this case, at timing T31, the disengagement of the second clutch mechanism 21 is completed, and the operation mode is switched to the series hybrid mode. The rotational speed N_ICE after the disengagement of the second clutch mechanism 21, i.e., the rotational speed N_ICE of the internal combustion engine 3 which is performing the motoring operation, changes in the increasing direction.

[0217] In the case where the 2nd clutch position sensor 52 is normal, the absolute value of the torque T_GEN of the motor generator 4 is not increased after the 2nd clutch 22 is disengaged. As a result, in this case, the rotational speed N_ICE slowly increases as shown by a dashed line due to the power generation operation, and the differential rotation of the 2nd clutch mechanism 21 does not easily increase. Therefore, it is assumed that if the 2nd clutch position sensor 52 is malfunctioning, the magnitude of the differential rotation of the 2nd clutch mechanism 21 does not immediately become greater than or equal to the prescribed value D2, and the disengagement determination of the 2nd clutch mechanism 21 is not properly performed.

[0218] In the present embodiment, at timing T31, the magnitude of the differential rotation of the 2nd clutch mechanism 21 is greater than the prescribed value D3, and the torque T_GEN of the motor generator 4 is increased, as a result of which the torque T_SUM increases. Therefore, the rotational speed N_ICE also greatly increases from timing T31 compared to the case where the 2nd clutch position sensor 52 is normal. As a result, at timing T32, the magnitude of the differential rotation of the 2nd clutch mechanism 21 becomes greater than or equal to the prescribed value D2, and the disengagement of the 2nd clutch mechanism 21 is not properly determined without greatly lagging from timing T31.

[0219] In this example, at timing T31, the absolute value of the torque T_SUM is increased. In addition, the rotational speed N_ICE increases after the 2nd clutch mechanism 21 is disengaged, and therefore the torque T_SUM whose absolute value is increased is set to the positive side, that is, a side greater than zero.

[0220] Thus, the rotational speed N_ICE is caused to change in the same direction as the rotational speed N_ICE required in the power generation operation in accordance with the torque T_SUM whose absolute value is increased, and therefore the rotational speed N_ICE required in the power generation operation can be quickly reached compared to the case where the rotational speed N_ICE is changed in the opposite direction.

[0221] Next, the main effects of the present embodiment will be described.

[0222] In the present embodiment, the clutch control method of the vehicle 1 is used in a vehicle 1 that has a second clutch mechanism 21, a second shift mechanism 40 that transmits a clutch operating force to the second clutch mechanism 21 via a second spring 44, and a second clutch position sensor 52 that detects disengagement of the second clutch mechanism 21. The clutch control method of the vehicle 1 includes the steps of performing disengagement of the second clutch mechanism 21 based on the second shift mechanism 40 while reducing a transmission torque, i.e., torque T_SUM, of the second clutch mechanism 21, determining disengagement of the second clutch mechanism 21 based on differential rotation of the second clutch mechanism 21 when the second clutch position sensor 52 fails, and increasing an absolute value of the torque T_SUM when the second clutch position sensor 52 fails, in a case where the differential rotation of the second clutch mechanism 21 does not change to an absolute value greater than a prescribed value D2 even if the second clutch mechanism 21 is disengaged.

[0223] According to this method, the differential rotation of the second clutch mechanism 21 can be increased in a case where the differential rotation of the second clutch mechanism 21 is difficult to increase after the second clutch mechanism 21 is disengaged. Therefore, disengagement of the second clutch mechanism 21 can be reliably determined when the second clutch position sensor 52 fails.

[0224] The controller 7 can be configured in the following manner.

[0225] Figure 19 is a diagram that represents control of a modification example of the present embodiment in a flowchart. Except for the fact that step S37B is provided instead of step S37A, Figure 19 the flowchart shown in Figure 17 is the same as the flowchart shown in

[0226] In step S37B, the controller 7 determines whether the vehicle 1 is in an acceleration state. Also, in the case of the acceleration state, the torque T_GEN of the power generation motor 4 is set to a prescribed value T_GEN1 (step S38), and in the case of the deceleration state, the torque T_GEN is set to a negative value of the prescribed value T_GEN1 (step S39).

[0227] In this case, when the series hybrid mode is switched, it is expected that the rotational speed N_ICE required in the power generation operation in the acceleration state increases, and the rotational speed N_ICE required in the power generation operation in the deceleration state decreases, and the torque T_GEN of the power generation motor 4 is set.

[0228] Therefore, in this method, when the second clutch mechanism 21 is caused to be disengaged, the rotational speed N_ICE can be changed in the same direction as the rotational speed N_ICE required in the power generation operation in accordance with the torque T_SUM. As a result, the rotational speed N_ICE after the second clutch mechanism 21 is disengaged can be rapidly changed to the rotational speed N_ICE required in the power generation operation. In addition, in the case where the second clutch mechanism 21 is not yet disengaged, a change in the behavior of the vehicle can not be easily felt.

[0229] In the case where the differential rotation of the second clutch mechanism 21 does not change to an absolute value greater than the prescribed value D2 even if the second clutch mechanism 21 is disengaged, the control to increase the absolute value of the torque T_SUM can be applied to the third embodiment.

[0230] In this case, the transmission torque of the second clutch mechanism 21 that is reduced is reduced to the prescribed value T_SUM1, but in the case where the differential rotation of the second clutch does not sufficiently increase even if the second clutch mechanism 21 is disengaged, the absolute value of the torque T_SUM can be increased to increase the differential rotation. Therefore, in this case, the reliability of the disengagement determination of the second clutch mechanism 21 is improved.

[0231] The above describes the embodiments of the present application, and the above embodiments show only a part of application examples of the present application, and the gist of the present application is not limited to the specific structures of the above embodiments.

[0232] For example, in the above embodiments, the case where the controller 7 is implemented by a single controller is described, but the controller 7 can also be constituted by a plurality of controllers.

Claims

1. A clutch control method for a vehicle, the vehicle having: an engaged clutch; and an engagement sensor that detects engagement of the engaged clutch, wherein, The clutch control method for the vehicle includes the following steps: When the engagement sensor is normal, if the magnitude of the differential rotation of the engaging clutch is less than or equal to a specified value, the engagement of the engaging clutch is performed, and the engagement of the clutch is determined by the engagement sensor. as well as When the engagement sensor malfunctions, the differential rotation of the engagement clutch is set to a value greater than the predetermined value. Based on this, the engagement of the engagement clutch is determined by the difference between the differential rotation of the engagement clutch at the engagement start time and the differential rotation of the engagement clutch.

2. The clutch control method for a vehicle according to claim 1, wherein, The specified value is shifted to a value greater than the variation in differential rotation after the engagement of the clutch.

3. The clutch control method for a vehicle according to claim 1, wherein, During vehicle acceleration, if the rotational speed of the upstream engagement element of the clutch is higher than the rotational speed of the downstream engagement element in the power transmission path via the clutch, the clutch engages. During vehicle deceleration, engagement of the clutch is performed when the rotational speed of the upstream engagement element in the power transmission path via the clutch is lower than the rotational speed of the downstream engagement element.

4. A clutch control method for a vehicle, the vehicle comprising: an engaging clutch; a shifting mechanism that transmits clutch operating force to the engaging clutch without a spring; and a disengagement sensor that detects the disengagement of the engaging clutch, wherein... The clutch control method for the vehicle includes the following steps: The transmission torque of the engaged clutch is reduced to disengage the engaged clutch based on the shifting mechanism; When the disconnection sensor fails, the disconnection of the engagement clutch is determined based on the differential rotation of the engagement clutch; as well as When the disconnect sensor malfunctions, the transmitted torque during the disengagement of the engagement clutch is reduced to an absolute value greater than that when the disconnect sensor is functioning normally.

5. The clutch control method for a vehicle according to claim 4, wherein, When the disconnected sensor fails, if the differential rotation does not change to an absolute value greater than a specified value even after a specified time has elapsed, the absolute value of the transmitted torque is increased.

6. The clutch control method for a vehicle according to claim 4, wherein, In the power transmission path via the engagement clutch, a generator is located upstream of the engagement clutch. When the rotational speed of the generator after disengagement is higher than that at the start of disengagement of the engagement clutch, the transmitted torque is reduced to the positive side; when the rotational speed of the generator after disengagement is lower than that at the start of disengagement of the engagement clutch, the transmitted torque is reduced to the negative side.

7. The vehicle clutch control method according to claim 4, wherein, During vehicle acceleration, the transmitted torque is reduced to the positive side, and during vehicle deceleration, the transmitted torque is reduced to the negative side.

8. A clutch control method for a vehicle, the vehicle comprising: an engaging clutch; a shifting mechanism that transmits a clutch working force to the engaging clutch via a spring; and a disengagement sensor that detects the disengagement of the engaging clutch, wherein, The clutch control method for the vehicle includes the following steps: The transmission torque of the engaged clutch is reduced to disengage the engaged clutch based on the shifting mechanism; When the disconnection sensor fails, the disconnection of the engagement clutch is determined based on the differential rotation of the engagement clutch; as well as When the disconnected sensor fails, if the differential rotation does not change to an absolute value greater than a specified value even after a specified time has elapsed, the absolute value of the transmitted torque will increase.

9. A clutch control device for a vehicle, the vehicle comprising: an engaged clutch; an engagement sensor that detects engagement of the engaged clutch; and a controller, wherein, When the engagement sensor is normal, and the magnitude of the differential rotation of the engaged clutch is less than or equal to a predetermined value, the controller engages the clutch, and determines the clutch engagement via the engagement sensor. When the engagement sensor malfunctions, the differential rotation of the engagement clutch is set to a value greater than the predetermined value. Based on this, the engagement of the engagement clutch is determined by the difference between the differential rotation of the engagement clutch at the engagement start time and the differential rotation of the engagement clutch.

10. A clutch control device for a vehicle, the vehicle comprising: an engaging clutch; a shifting mechanism that transmits clutch operating force to the engaging clutch without a spring; a disengagement sensor that detects the disengagement of the engaging clutch; and a controller, wherein, The controller reduces the transmitted torque of the engaged clutch to disengage the engaged clutch based on the shifting mechanism. When the disconnection sensor malfunctions, the disengagement of the engagement clutch is determined based on the differential rotation of the engagement clutch. When the disconnect sensor malfunctions, the transmitted torque during disengagement of the engagement clutch is reduced to an absolute value greater than that of the disconnect sensor when it is functioning normally.

11. A clutch control device for a vehicle, the vehicle comprising: an engaging clutch; a shifting mechanism that transmits clutch operating force to the engaging clutch via a spring; a disengagement sensor that detects the disengagement of the engaging clutch; and a controller, wherein, The controller reduces the transmitted torque of the engaged clutch to disengage the engaged clutch based on the shifting mechanism. When the disconnection sensor malfunctions, the disengagement of the engagement clutch is determined based on the differential rotation of the engagement clutch. When the disconnected sensor fails, if the differential rotation does not change to an absolute value greater than a specified value even after a specified time has elapsed, the absolute value of the transmitted torque will increase.

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