Control apparatus for vehicle drive-force transmitting apparatus

Patent metadata

Field	Value
Publication number	US-10968962-B2
Application number	US-201916374773-A
Country	US
Kind code	B2
Filing date	Apr 4, 2019
Priority date	Apr 4, 2018
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

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.

First claim

What is claimed is:

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; the drive-force transmitting apparatus including 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; the dog clutch including 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; the control apparatus comprising:
a processor programmed to function as:
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
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 the 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, 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, and
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.

2. 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.

3. The control apparatus according to claim 1 ,
wherein the 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 the 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 the failure determining portion determines that there is the possibility that the gear noise occurs in the dog clutch.

4. 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.

5. The control apparatus according to claim 4 ,
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.

6. 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; the drive-for

Assignees

• Toyota Motor Co Ltd

Inventors

• Kamijo Satoshi
• Sawada Makoto
• Matsuo Kenji
• Suzumura Kyohei
• Kametani Yoshisuke
• Yoshida Michio
• Takeda Hiroki
• Seo Takashi

Classifications

• F16D2500/10456

  Synchro clutch · CPC title

• F16D23/06 Primary

  and a blocking mechanism preventing the engagement of the main clutch prior to synchronisation · CPC title

• F16D2500/30426

  Speed of the output shaft · CPC title

• F16H2061/0474

  by smoothing engagement or release of positive clutches; Methods or means for shock free engagement of dog clutches · CPC title

• F16D2023/0631

  Sliding sleeves; Details thereof · CPC title