CONTROL APPARATUS FOR VEHICLE DRIVE-FORCE TRANSMITTING APPARATUS

• US 20190309805A1
• Filed: 04/04/2019
• Published: 10/10/2019
• Est. Priority Date: 04/04/2018
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: KAMIJO, Satoshi, SAWADA, Makoto, MATSUO, Kenji, SUZUMURA, Kyohei, KAMETANI, Yoshisuke, YOSHIDA, Michio, TAKEDA, Hiroki, SEO, Takashi
• Granted Patent: US 10,968,962 B2
• Time in Patent Office: Days
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 41/022 in relation with the clutch status
• CPC Class Codes: F16D 2023/0631 Sliding sleeves; Details thereof
• CPC Class Codes: F16D 2023/0693 Clutches with hydraulic actuation
• CPC Class Codes: F16D 23/06 and a blocking mechanism preventing the engagement of the main clutch prior to synchronisation
• CPC Class Codes: F16D 2500/10456 Synchro clutch
• CPC Class Codes: F16D 2500/30415 Speed of the input shaft
• CPC Class Codes: F16D 2500/30426 Speed of the output shaft
• CPC Class Codes: F16D 2500/50233 Clutch wear adjustment operation
• CPC Class Codes: F16D 2500/50293 Reduction of vibrations
• CPC Class Codes: F16D 2500/5104 Preventing failures
• CPC Class Codes: F16D 2500/5114 Failsafe
• CPC Class Codes: F16D 2500/70424 Outputting a clutch engaged-disengaged signal

Abstract

A control apparatus for a vehicle drive-force transmitting apparatus including a dog clutch that is operated by an actuator to selectively connect and disconnect a drive-force transmitting path. In process of switching of the dog clutch from released state to engaged state, the control apparatus determines whether a rotational speed difference of the dog clutch is equal to or larger than a given difference value when a sleeve of the dog clutch is positioned on an engaging side of a synchronizing position for placing the dog clutch into the engaged state, and stops the switching of the dog clutch to the engaged state and causes the actuator to place the dog clutch back into the released state, when determining that the rotational speed difference is equal to or larger than the given difference value with the sleeve being positioned on the engaging side of the synchronizing position.

Claims

1. A control apparatus for a drive-force transmitting apparatus that is to be provided in a vehicle having a drive force source and drive wheels,

wherein the drive-force transmitting apparatus includes a dog clutch which is provided with a synchromesh mechanism and which is to be operated by an actuator to selectively connect and disconnect a drive-force transmitting path between the drive force source and the drive wheels,

wherein the dog clutch includes a sleeve that is to be moved by the actuator so as to switch an operation state of the dog clutch between an engaged state in which the drive-force transmitting path is connected and a released state in which the drive-force transmitting path is disconnected, such that a rotational speed difference between an input-side rotational speed and an output-side rotational speed of the dog clutch is to be zeroed when the sleeve is positioned in a synchronizing position in process of switching of the dog clutch from the released state to the engaged state,

wherein said control apparatus comprises a failure determining portion configured, in the process of the switching of the dog clutch from the released state to the engaged state, to determine whether the rotational speed difference is equal to or larger than a given difference value when the sleeve is positioned on an engaging side of the synchronizing position for placing the dog clutch into the engaged state, and

wherein said control apparatus comprises a clutch control portion configured, upon execution of control for operating the actuator for the switching of the dog clutch from the released state to the engaged state, to stop the switching of the dog clutch from the released state to the engaged state and to cause the actuator to place the dog clutch back into the released state, when said failure determining portion determines that the rotational speed difference is equal to or larger than the given difference value with the sleeve being positioned on the engaging side of the synchronizing position.

2. The control apparatus according to claim 1, wherein the failure determining portion is configured to determine whether the sleeve is positioned on the engaging side of the synchronizing position, depending on whether the sleeve is positioned to be distant from the synchronizing position by at least a given distance value on the engaging side of the synchronizing position, before the rotational speed difference becomes zero.

3. The control apparatus according to claim 2, wherein the failure determining portion is configured to determine whether the sleeve is positioned to be distant from the synchronizing position by at least the given distance value on the engaging side of the synchronizing position, depending on whether a state in which the sleeve is positioned to be distant from the synchronizing position by at least the given distance value on the engaging side of the synchronizing position, continues for at least a given length of time.

4. The control apparatus according to claim 1, wherein the failure determining portion is configured to determine whether the rotational speed difference is equal to or larger than the given difference value, depending on whether the rotational speed difference becomes equal to or larger than the given difference value after the rotational speed difference temporarily becomes zero.

5. The control apparatus according to claim 4, wherein the failure determining portion is configured to determine whether the rotational speed difference is equal to or larger than the given difference value, depending on whether the rotational speed difference is equal to or larger than a first given difference value or depending on whether a state in which the rotational speed difference is equal to or larger than a second given difference value that is smaller than the first given difference value, continues for at least a given length of time.

6. The control apparatus according to claim 1,

wherein the drive-force transmitting apparatus further includes:

an input rotary member to which the drive force is to be transmitted from the drive force source;

an output rotary member from which the drive force is to be outputted to the drive wheels;

a gear mechanism configured to provide at least one gear ratio;

a continuously-variable transmission mechanism including a primary pulley, a secondary pulley and a transfer element looped over the primary and secondary pulleys; and

first and second frictional engagement devices,

wherein the drive-force transmitting apparatus defines a plurality of drive-force transmitting paths that are provided in parallel with each other between the input rotary member and the output rotary member,

wherein the plurality of drive-force transmitting paths include a first drive-force transmitting path that corresponds to the drive-force transmitting path, such that the drive force is transmitted by the gear mechanism through the first drive-force transmitting path when the first drive-force transmitting path is established by engagements of the first frictional engagement device and the dog clutch, and

wherein the plurality of drive-force transmitting paths include a second drive-force transmitting path, such that the drive force is transmitted by the continuously-variable transmission mechanism through the second drive-force transmitting path when the second drive-force transmitting path is established by engagement of the second frictional engagement device.

7. The control apparatus according to claim 1,

wherein said failure determining portion is configured, when determining that the rotational speed difference is equal to or larger than the given difference value with the sleeve being positioned on the engaging side of the synchronizing position in the process of the switching of the dog clutch from the released state to the engaged state, to determine that there is a possibility that a gear noise occurs in the dog clutch, and

wherein said clutch control portion is configured, upon execution of the control for operating the actuator for the switching of the dog clutch from the released state to the engaged state, to stop the switching of the dog clutch from the released state to the engaged state and to cause the actuator to place the dog clutch back into the released state, when said failure determining portion determines that there is the possibility that the gear noise occurs in the dog clutch.

8. The control apparatus according to claim 1,

wherein the dog clutch further includes an input-side rotary member that is to be rotated at the input-side rotational speed and an output-side rotary member that is to be rotated at the output-side rotational speed,

wherein the sleeve is fitted with one of the input-side rotary member and the output-side rotary member, such that the sleeve is unrotatable and movable in an axial direction of the one of the input-side rotary member and the output-side rotary member, relative to the one of the input-side rotary member and the output-side rotary member, and

wherein the sleeve has spline teeth which are provided in an circumferential surface of the sleeve, and which are to be brought into meshing engagements with spline teeth provided in a circumferential surface of the other of the input-side rotary member and the output-side rotary member by movement of the sleeve in a direction away from a releasing side of the synchronizing position that is opposite to the engaging side of the synchronizing position in the axial direction in the process of the switching of the dog clutch from the released state to the engaged state.

9. The control apparatus according to claim 8,

wherein the dog clutch further includes an annular member which is substantially coaxial with the other of the input-side rotary member and the output-side rotary member and which is rotatable together with the sleeve,

wherein the annular member has a tapered circumferential surface that is to be fitted with a tapered circumferential surface of the other of the input-side rotary member and the output-side rotary member, and

wherein, in the process of the switching of the dog clutch from the released state to the engaged state, the annular member is to be pressed against the other of the input-side rotary member and the output-side rotary member by the movement of the sleeve in the direction away from the releasing side of the synchronizing position, for thereby causing the rotational speed difference to be reduced by a friction generated between the tapered circumferential surface of the annular member and the tapered circumferential surface of the other of the input-side rotary member and the output-side rotary member.