Transmission structure

Patent metadata

Field	Value
Publication number	US-12498028-B2
Application number	US-202418619295-A
Country	US
Kind code	B2
Filing date	Mar 28, 2024
Priority date	Apr 3, 2023
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

[Problem] A transmission structure that may improve a traveling feeling when a drive traveling state is interrupted in traveling and then the drive traveling state is resumed is provided. [Solution] A control device actuates a clutch actuator so that only a clutch mechanism on a most downstream side in a transmission direction in a selected shift gear is brought to a disengaged state when receiving a power cut-off signal in a state in which a traveling state change member is subjected to a forward operation or a reverse operation, and, actuates the clutch actuator so that only the clutch mechanism on the most downstream side in the transmission direction in the selected presumed shift gear is brought to a disengaged state based on a traveling state, and in addition, actuates a gear shift actuator so that a gear ratio of a continuously variable transmission mechanism that realizes a vehicle speed at that time point in the presumed shift gear is obtained while the power cut-off signal is valid, and actuates the clutch actuator so that the clutch mechanism on the most downstream side in the transmission direction in the presumed shift gear at that time point is brought to an engaged state when a cancel signal for canceling the power cut-off signal is input.

First claim

The invention claimed is:

1 . A transmission structure interposed in a transmission path extending from a drive source to traveling wheels, the transmission structure comprising:
transmission mechanisms which have a plurality of shift gears and a plurality of clutch mechanisms disposed for the plurality of shift gears; a clutch actuator that performs engagement and disengagement of the plurality of clutch mechanisms; a continuously variable transmission mechanism that continuously varies speeds of rotation power in the plurality of shift gears; a gear shift actuator that performs an operation of changing an output of the continuously variable transmission mechanism; a traveling state change member that is operable by a person; and a control device that actuates, in a drive traveling state in which a vehicle traveling direction recognized based on at least one of a vehicle speed and a transmission (TM) gear ratio of the transmission structure when the traveling state change member is in a forward position or a reverse position matches a forward-reverse operation direction of the traveling state change member, the clutch actuator so that a clutch mechanism which realize a shift gear corresponding to a traveling state at that time point is brought to an engaged state, and in addition, the gear shift actuator so that a drive rotation speed corresponding to an operation state of the traveling state change member in the shift gear is obtained, wherein the control device (1) actuates the clutch actuator, when a power cutoff signal is input during the drive traveling, so that only one of the clutch mechanisms on a most downstream side in a transmission direction in the selected shift gear is brought to a disengaged state, (2) determines a presumed shift gear to be selected in a coasting traveling state caused by power cutoff, actuates the clutch actuator so that only one of the clutch mechanisms on the most downstream side in the transmission direction in the presumed shift gear is brought to a disengaged state and the other clutch mechanisms are brought to an engaged state, and in addition, actuates the gear shift actuator so as to obtain a hydro-static transmission (HST) speed ratio which realizes an output state corresponding to a vehicle speed at that time point in the presumed shift gear, and (3) actuates the clutch actuator, when a drive traveling state is resumed due to an input of a cancel signal for canceling a power cut-off signal in a state in which the traveling state change member is subjected to a forward operation or a reverse operation, so that the clutch mechanism on the most downstream side in the transmission direction in the presumed shift gear at the time point is brought to an engaged state.

2 . The transmission structure according to claim 1 , wherein
the transmission mechanisms include a planetary gear mechanism which has a first element, a second element, and a third element which functions as an input section of a continuously variable transmission output, an input-side first transmission mechanism capable of operatively transmitting rotation power of the drive source to the first element, an input-side second transmission mechanism capable of operatively transmitting rotation power of the drive source to the second element, an output-side first transmission mechanism capable of operatively transmitting rotation power of the second element to a gear shift output shaft disposed on a downstream side in a transmission direction relative to the input-side first and second transmission mechanisms, an output-side second transmission mechanism capable of operatively transmitting rotation power of the first element to the gear shift output shaft, and a forward-side transmission mechanism and a reverse-side transmission mechanism which output rotation power of the gear shift output shaft as forward drive force and reverse drive force to the traveling wheels, the clutch mechanisms include input-side first and second clutch mechanisms which engage or disengage power transmission of the input-side first and second transmission mechanisms, respectively, output-side first and second clutch mechanisms which engage or disengage power transmission of the output-side first and second transmission mechanisms, respectively, and a forward-side clutch mechanism and a reverse-side clutch mechanism which engage or disengage power transmission of the forward-side transmission mechanism and the reverse-side transmission mechanism, respectively, and the control device determines the presumed shift gear such that, (1) in a case where the coasting traveling state is in a traveling first gear range, a first gear which is realized when the input-side first clutch mechanism, the output-side first clutch mechanism, and the forward-side clutch mechanism or the reverse-side clutch mechanism are brought to the engaged state is determined as the presumed shift gear, and (2) in a case where the coasting traveling state is in a traveling second gear range of a speed higher than the traveling first gear range, a second gear which is realized when the input-side second clutch mechanism, the output-side second clutch mechanism, and the forward-side clutch mechanism or the reverse-side clutch mechanism are brought to the engaged state is determined as the presumed shift gear.

3 . The transmission structure according to claim 2 , wherein
the traveling state change member includes a vehicle speed setting member and a forward-reverse switching operation member, and the control device actuates the gear shift actuator in response to an operation of the vehicle speed setting member and actuates the clutch actuator so that switching between engagement and disengagement of the forward-side and reverse-side clutch mechanisms is performed in response to an operation of the forward-reverse switching operation member.

4 . The transmission structure according to claim 2 , wherein
when the cancel signal for canceling the power cut-off signal is input for resuming to the drive traveling state, the control device operatively controls the clutch actuator and the gear shift actuator such that, (1) when the vehicle traveling direction is the same as a forward-reverse operation direction of the traveling state change member or when the vehicle traveling direction is opposite to the forward-reverse operation direction of the traveling state change member but has a value equal to or smaller than a threshold value in the vicinity of zero speed set in advance, the forward-side clutch mechanism or the reverse-side clutch mechanism corresponding to the forward-reverse operation direction of the traveling state change member is determined to be a clutch mechanism on the most downstream side in the transmission direction in the presumed shift gear and is brought to an engaged state, (2) when the vehicle traveling direction is opposite to the forward-reverse operation direction of the traveling state change member and has a value larger than the threshold value in the vicinity of zero speed, the forward-side clutch mechanism or the reverse-side clutch mechanism which is opposite to the forward-reverse operation direction of the traveling state change member is determined to be a clutch mechanism on the most downstream side in the transmission direction in the presumed shift gear and is brought to an engaged state, and (3) when the forward-side clutch mechanism or the reverse-side clutch mechanism which is opposite to the forward-reverse operation direction of the traveling state change member is determined to be a clutch mechanism on the most downstream side in the transmission direction in the presumed shift gear and is brought to an engaged state, the clutch mechanism is brought to a disengaged state at a predetermined timing and furthermore the forward-side clutch mechani

Assignees

• Kanzaki Kokyukoki Mfg Co Ltd

Inventors

• Takahashi Takumi
• Ogura Kohei
• Ito Fumiaki
• Inoue Tasuku

Classifications

• B60W2710/0655

  Coasting condition · CPC title

• B60W2510/0647

  Coasting condition · CPC title

• B60W30/18072

  Coasting · CPC title

• F16H61/04

  Smoothing ratio shift · CPC title

• B60Y2200/221

  Tractors · CPC title