vehicle

Abstract

To provide a technology capable of suppressing shortening of a service life of a lock-up clutch.SOLUTION: In a manual mode, when a shift clutch is disengaged by operation of a clutch operation unit in a state where a shift clutch is engaged and a lock-up clutch is engaged, a control unit may use input of a command to change a transmission shift position to neutral by operation of the shift operation unit as a trigger to disengage the lock-up clutch, and then change the transmission shift position to neutral.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed in this specification relates to vehicles.

Background Art

[0002] Patent Document 1 discloses a control method for a lock-up clutch that mechanically couples the input and output shafts of a torque converter with a lock-up clutch and a clutch for shifting. In the control method of Patent Document 1, when both the lock-up clutch and the clutch switch are off, the clutch for shifting is connected. Next, when it is confirmed that the tire rotational speed difference is within the range of the set value, the lock-up clutch is turned on, and when it is confirmed that the tire rotational speed difference is not within the range of the set value, the lock-up clutch is turned off.

[0003] Also, in the control method of Patent Document 1, it is determined whether the clutch switch for shifting and the lock-up clutch are on (S2). When it is confirmed that they are on (YES in S2), the clutch for shifting is put into the disengaged state, and the lock-up clutch is also put into the disengaged state (S3).

Prior Art Documents

Patent Documents

[0004] <U+

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technology described in Patent Document 1, the lock-up clutch is disengaged each time the transmission clutch is disengaged, which increases the frequency of engagement and disengagement of the lock-up clutch and can shorten its lifespan. For example, if the transmission clutch is frequently engaged and disengaged while maintaining a specific shift position, the lifespan of the lock-up clutch may be shortened. Therefore, this specification provides a technology that can suppress the shortening of the lock-up clutch's lifespan. [Means for solving the problem]

[0006] A first aspect of this technology provides a vehicle comprising: a transmission clutch that transmits the rotation of a first drive shaft connected to an engine to a second drive shaft; a torque converter with a lock-up clutch that transmits the rotation of the second drive shaft to a third drive shaft; a transmission that transmits the rotation of the third drive shaft to a fourth drive shaft; a clutch operation unit that accepts user operation to disengage the transmission clutch; a shift operation unit that accepts user operation to change the shift position of the transmission; and a control unit. The control unit can change the shift position of the transmission in automatic mode and manual mode. In automatic mode, the control unit changes the shift position of the transmission based on the operating state of the engine while the transmission clutch is engaged. In manual mode, the control unit changes the shift position of the transmission when an instruction to change the shift position of the transmission is input by operating the shift operation unit while the transmission clutch is disengaged. In manual mode, the control unit may, when the transmission clutch is engaged and the lock-up clutch is engaged, disengage the transmission clutch by operation of the clutch operation unit, triggered by an instruction to change the transmission's shift position to neutral by operation of the shift operation unit, disengage the lock-up clutch and then change the transmission's shift position to neutral.

[0007] With this configuration, the lock-up clutch is not disengaged simply by the transmission clutch being disengaged. Instead, the lock-up clutch is disengaged only when an instruction to change the transmission's shift position to neutral is input through the operation of the shift control unit. This prevents the lock-up clutch from being disengaged frequently, thereby preventing a shortened lifespan for the lock-up clutch.

[0008] In a second embodiment, in the first embodiment, the control unit may, in manual mode, start from a state in which the gear shift clutch and the lock-up clutch are disengaged, and triggered by an instruction to change the shift position of the transmission from neutral to a gear other than neutral by operating the shift operation unit, change the shift position of the transmission to the instructed gear, and then engage the lock-up clutch.

[0009] With this configuration, the lock-up clutch engages only after the transmission shift position is changed to a gear other than neutral, resulting in a driving feel similar to that of a manual transmission vehicle. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic diagram showing the vehicle of the embodiment. [Figure 2] A diagram showing the shift positions of the transmission in manual mode in the embodiment. [Modes for carrying out the invention]

[0011] Vehicle 2 of the embodiment will be described with reference to the drawings. Vehicle 2 of the embodiment is an automatic transmission vehicle (AT vehicle) with a manual mode. As shown in Figure 1, Vehicle 2 comprises an engine 10, a transmission clutch 20, a torque converter 30 with a lock-up clutch 32, and a transmission 40. Vehicle 2 also comprises a first drive shaft 12, a second drive shaft 14, a third drive shaft 16, and a fourth drive shaft 18. Furthermore, Vehicle 2 comprises a clutch operating unit 22, a shift operating unit 42, and a control unit 50.

[0012] The engine 10 is, for example, a gasoline engine, and the rotation of its crankshaft drives the first drive shaft 12. The first drive shaft 12 is positioned between the engine 10 and the transmission clutch 20. One end of the first drive shaft 12 is connected to the engine 10 and rotates due to the driving force of the engine 10. The other end of the first drive shaft 12 is connected to the transmission clutch 20 and transmits the driving force of the engine 10 to the transmission clutch 20.

[0013] The gear shift clutch 20 is positioned between the first drive shaft 12 and the second drive shaft 14. The gear shift clutch 20 is connected to the first drive shaft 12 and the second drive shaft 14. The gear shift clutch 20 transmits the rotation of the first drive shaft 12 to the second drive shaft 14.

[0014] The transmission clutch 20 is configured to be switchable between an engaged state and a disengaged state. The transmission clutch 20 includes, for example, one or more clutch plates 20a on the input side (first drive shaft 12 side) and one or more clutch plates 20b on the output side (second drive shaft 14 side). The transmission clutch 20 is engaged when the pair of clutch plates 20a and 20b come into contact with each other, and disengaged when the pair of clutch plates 20a and 20b separate from each other. When the transmission clutch 20 is engaged, the rotation of the first drive shaft 12 is transmitted to the second drive shaft 14, and when the transmission clutch 20 is disengaged, the rotation of the first drive shaft 12 is not transmitted to the second drive shaft 14. The transmission clutch 20 can be switched between an engaged state and a disengaged state by user operation at the clutch operating unit 22.

[0015] The clutch operating unit 22 receives user input to switch between the engaged and disengaged states of the transmission clutch 20. The clutch operating unit 22 and the transmission clutch 20 are connected by a mechanical mechanism. The clutch operating unit 22 includes, for example, a clutch pedal 24 that is pressed by the user's foot. When the clutch pedal 24 is pressed, the transmission clutch 20 is disengaged, and when the clutch pedal 24 is not pressed, the transmission clutch 20 is engaged. The mechanical configuration between the clutch pedal 24 and the transmission clutch 20 is already known, so a detailed explanation is omitted.

[0016] The second drive shaft 14 is positioned between the transmission clutch 20 and the torque converter 30. One end of the second drive shaft 14 is connected to the transmission clutch 20, and it rotates together with the first drive shaft 12 via the transmission clutch 20. The other end of the second drive shaft 14 is connected to the torque converter 30, and it transmits the rotation of the first drive shaft 12 to the torque converter 30.

[0017] The torque converter 30 is positioned between the second drive shaft 14 and the third drive shaft 16. The torque converter 30 is connected to both the second drive shaft 14 and the third drive shaft 16. The torque converter 30 transmits the rotation of the second drive shaft 14 to the third drive shaft 16.

[0018] The torque converter 30 comprises, for example, a pump impeller, a turbine liner, and a stator, and indirectly transmits the rotation of the pump impeller to the turbine liner via a fluid (e.g., oil). The pump impeller is connected to a second drive shaft 14, and the turbine liner is connected to a third drive shaft 16. The torque converter 30 indirectly transmits the rotation of the second drive shaft 14 to the third drive shaft 16 via a fluid (e.g., oil).

[0019] The torque converter 30 further includes a lock-up clutch 32. The lock-up clutch 32 is disposed between the second drive shaft 14 and the third drive shaft 16. The lock-up clutch 32 is connected to the second drive shaft 14 and the third drive shaft 16. The lock-up clutch 32 transmits the rotation of the second drive shaft 14 to the third drive shaft 16.

[0020] The lock-up clutch 32 is configured to be switchable between a connected state and a disengaged state. The lock-up clutch 32 includes, for example, one or more clutch plates 32a on the input side (the second drive shaft 14 side) and one or more clutch plates 32b on the output side (the third drive shaft 16 side). When the pair of clutch plates 32a and 32b contact each other, the lock-up clutch 32 is in the connected state, and when the pair of clutch plates 32a and 32b are separated from each other, the lock-up clutch 32 is in the disengaged state. When the lock-up clutch 32 is in the connected state, the rotation of the second drive shaft 14 is directly transmitted to the third drive shaft 16, and when the lock-up clutch 32 is in the disengaged state, the rotation of the second drive shaft 14 is indirectly transmitted to the third drive shaft 16 through the torque converter 30 via a fluid.

[0021] The third drive shaft 16 is disposed between the torque converter 30 and the transmission 40. One end of the third drive shaft 16 is connected to the torque converter 30 and rotates together with the second drive shaft 14 via the torque converter 30 or the lock-up clutch 32. The other end of the third drive shaft 16 is connected to the transmission 40 and transmits the rotation of the second drive shaft 14 to the transmission 40.

[0022] The transmission 40 is disposed between the third drive shaft 16 and the fourth drive shaft 18. The transmission 40 is connected to the third drive shaft 16 and the fourth drive shaft 18. The transmission 40 transmits the rotation of the third drive shaft 16 to the fourth drive shaft 18. The transmission 40 can transmit the rotation of the third drive shaft 16 to the fourth drive shaft 18 at a plurality of gear ratios.

[0023] The transmission 40 is an automatic transmission. The transmission 40 includes, for example, a sun gear, a ring gear, planetary gears, and a planetary carrier, and through these combinations, it can take any shift position from a plurality of shift positions. The plurality of shift positions of the transmission 40 include, for example, a plurality of gear speeds (e.g., first gear, second gear, third gear, reverse) and a neutral position. When the shift position of the transmission 40 is switched, the rotation of the third drive shaft 16 is transmitted to the fourth drive shaft 18 at a gear ratio corresponding to the gear speed. However, in the neutral position, the rotation of the third drive shaft 16 is not transmitted to the fourth drive shaft 18. The shift position of the transmission 40 can be switched by a user operation on the shift operation unit 42.

[0024] The shift operation unit 42 receives a user operation for changing the shift position of the transmission 40. The shift operation unit 42 includes, for example, a shift lever 44. When the shift lever 44 is operated, an instruction to change the shift position of the transmission 40 is input to the control unit 50. For example, when the shift lever 44 is moved to the position of a specific gear speed (e.g., first gear), an instruction to change the shift position of the transmission 40 to the specific gear speed (e.g., first gear) is input to the control unit 50. Also, when the shift lever 44 is moved to the neutral position, an instruction to change the shift position of the transmission 40 to neutral is input to the control unit 50. The neutral position is, for example, the position between a plurality of gear speeds (e.g., first gear, second gear, third gear, reverse). The control unit 50 changes the shift position of the transmission 40 based on the instruction input from the shift operation unit 42.

[0025] The fourth drive shaft 18 is positioned between the transmission 40 and the differential 70. One end of the fourth drive shaft 18 is connected to the transmission 40 and rotates together with the third drive shaft 16 via the transmission 40. The other end of the fourth drive shaft 18 is connected to the differential 70 and transmits the rotation of the third drive shaft 16 to the differential 70.

[0026] The differential gear 70 is located between the fourth drive shaft 18 and the pair of wheel axles 72. The differential gear 70 is connected to the fourth drive shaft 18 and the pair of wheel axles 72. The differential gear 70 transmits the rotation of the fourth drive shaft 18 to the pair of wheel axles 72.

[0027] Each wheel axle 72 is positioned between the differential 70 and the wheel 74. One end of each wheel axle 72 is connected to the differential 70 and rotates together with the fourth drive shaft 18 via the differential 70. The other end of each wheel axle 72 is connected to the wheel 74 and transmits the rotation of the fourth drive shaft 18 to the wheel 74. The vehicle 2 moves as a pair of wheels 74 rotate.

[0028] The control unit 50 includes, for example, a CPU, ROM, RAM, etc., and performs various controls and processes based on a predetermined program. The control unit 50 is sometimes called an ECU (Engine Control Unit). For example, the control unit 50 changes the shift position of the transmission 40 by sending a signal to the transmission 40. The control unit 50 also switches the engaged state and disengaged state of the lock-up clutch 32 by sending a signal to the torque converter 30.

[0029] The control unit 50 can change the shift position of the transmission 40 between automatic mode and manual mode. The automatic mode and manual mode can be switched manually by the user, for example. For example, when a predetermined switch button (not shown) is pressed, the automatic mode and manual mode are switched. In automatic mode, with the gear shift clutch 20 engaged, the control unit 50 changes the shift position of the transmission 40 based on the operating state of the engine 10 (for example, the rotational speed of the engine 10).

[0030] In manual mode, the control unit 50 changes the shift position of the transmission 40 when the shift clutch 20 is disengaged and an instruction to change the shift position of the transmission 40 is input by the operation of the shift operation unit 42.

[0031] This section provides a detailed explanation of the shift position in manual mode. For the purpose of explaining manual mode, we assume that the initial state (t0), as shown in Figure 2, is that the gear shift clutch 20 is engaged, the lock-up clutch 32 is disengaged, the shift position of the transmission 40 is neutral, and the position of the shift lever 44 is neutral. In Figure 2, "LU-ON" is displayed when the lock-up clutch 32 is engaged, and nothing is displayed when the lock-up clutch 32 is disengaged.

[0032] To change the shift position of the transmission 40 to 1st gear from the initial state (t0) using manual mode, the user depresses the clutch pedal 24 to disengage the gear shift clutch 20 (t1). Next, with the gear shift clutch 20 disengaged, the user moves the shift lever 44 from the neutral position to the 1st gear position (t2). This sends an instruction to the control unit 50 to change the shift position of the transmission 40 from neutral to 1st gear.

[0033] The control unit 50, triggered by an instruction to change the shift position of the transmission 40 from neutral to first gear, sends a signal to the transmission 40, changing the shift position of the transmission 40 to first gear (t2). Subsequently, the control unit 50 sends a signal to the torque converter 30, switching the lock-up clutch 32 to the engaged state (t3). The time interval between t2 and t3 is, for example, less than 1 second. After that, when the user releases their foot from the clutch pedal 24, the gear shift clutch 20 becomes engaged (t4).

[0034] Subsequently, when changing the shift position of the transmission 40 from 1st gear to 2nd gear in manual mode, the user depresses the clutch pedal 24 to disengage the gear shift clutch 20 (t5). Next, with the gear shift clutch 20 disengaged, the user moves the shift lever 44 from the 1st gear position to the neutral position (t6). This sends an instruction to the control unit 50 to change the shift position of the transmission 40 to neutral.

[0035] The control unit 50, triggered by an instruction to change the shift position of the transmission 40 to neutral, sends a signal to the torque converter 30 and switches the lock-up clutch 32 to the disengaged state (t6). Subsequently, the control unit 50 sends a signal to the transmission 40 and changes the shift position of the transmission 40 to neutral (t7). The time interval between t6 and t7 is, for example, less than 1 second.

[0036] Next, with the gear shift clutch 20 disengaged, the user moves the shift lever 44 from the neutral position to the second gear position (t8). This sends an instruction to the control unit 50 to change the shift position of the transmission 40 from neutral to second gear.

[0037] The control unit 50, triggered by an instruction to change the shift position of the transmission 40 from neutral to second gear, sends a signal to the transmission 40, changing the shift position of the transmission 40 to second gear (t8). Subsequently, the control unit 50 sends a signal to the torque converter 30, switching the lock-up clutch 32 to the engaged state (t9). The time interval between t8 and t9 is, for example, less than 1 second. After that, when the user releases their foot from the clutch pedal 24, the gear shift clutch 20 becomes engaged (t10).

[0038] Subsequently, when changing the shift position of transmission 40 from 2nd gear to 3rd gear, the same control as when changing from 1st gear to 2nd gear is performed. Also, when changing the shift position of transmission 40 from 3rd gear to neutral, the same control as when changing from 1st gear to neutral is performed.

[0039] (effect) The vehicle 2 of the embodiment has been described above. As is clear from the above description, in the vehicle 2 of the embodiment, when the transmission clutch 20 is engaged and the lock-up clutch 32 is engaged in manual mode, the control unit 50, triggered by an instruction to change the shift position of the transmission 40 to neutral by an operation of the clutch operation unit 22, disengages the transmission clutch 20 and then changes the shift position of the transmission 40 to neutral (see t5-t7 in Figure 2).

[0040] With this configuration, the lock-up clutch 32 is not disengaged simply by the transmission clutch 20 being disengaged. Instead, the lock-up clutch 32 is disengaged only when an instruction to change the shift position of the transmission 40 to neutral is input by the operation of the shift operation unit 42. This prevents the lock-up clutch 32 from being disengaged frequently, thereby preventing a shortened lifespan for the lock-up clutch 32.

[0041] Furthermore, in manual mode, the control unit 50, starting from a state where the gear shift clutch 20 and the lock-up clutch 32 are disengaged, is triggered when an instruction is received from the shift operation unit 42 to change the shift position of the transmission 40 from neutral to a gear other than neutral (for example, 1st gear). The control unit 50 then changes the shift position of the transmission 40 to the instructed gear (for example, 1st gear), and then engages the lock-up clutch 32 (see t1-t3 in Figure 2).

[0042] With this configuration, the lock-up clutch 32 engages after the shift position of the transmission 40 is changed to the specified gear, resulting in a driving feel similar to that of a manual transmission (MT) vehicle. The user can experience the sensation of driving an MT vehicle even while driving an AT vehicle.

[0043] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of symbols]

[0044] 2: Vehicle, 10: Engine, 12: First drive shaft, 14: Second drive shaft, 16: Third drive shaft, 18: Fourth drive shaft, 20: Transmission clutch, 22: Clutch operating unit, 24: Clutch pedal, 30: Torque converter, 32: Lock-up clutch, 40: Transmission, 42: Shift operating unit, 44: Shift lever, 50: Control unit

Claims

1. A transmission clutch that transmits the rotation of the first drive shaft connected to the engine to the second drive shaft, A torque converter with a lock-up clutch that transmits the rotation of the second drive shaft to the third drive shaft, A transmission that transmits the rotation of the third drive shaft to the fourth drive shaft, A clutch operating unit that accepts user input for disengaging the aforementioned gear shift clutch, A shift operation unit that accepts user input to change the shift position of the transmission, It comprises a control unit and, The control unit, The shift position of the transmission can be changed between automatic mode and manual mode. In the automatic mode, with the gear shift clutch engaged, the shift position of the transmission is changed based on the operating state of the engine. In the manual mode, when the gear shift clutch is disengaged and an instruction to change the shift position of the transmission is input by operating the shift control unit, the shift position of the transmission is changed. In the manual mode, when the transmission clutch is engaged and the lock-up clutch is engaged, and the transmission clutch is disengaged by operation of the clutch operating unit, the vehicle is triggered by an instruction to change the transmission's shift position to neutral by operation of the shift operating unit to disengage the lock-up clutch and then change the transmission's shift position to neutral.

2. A vehicle according to claim 1, In the manual mode, the control unit, when an instruction is received from the shift operation unit to change the shift position of the transmission from neutral to a gear other than neutral, triggers the control unit to change the shift position of the transmission to the specified gear, and then engages the lock-up clutch.

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