Shift lock device

Abstract

To provide a shift lock device that performs shifting to a lock state at appropriate timing.SOLUTION: A shift lock device provided in a shift-by-wire device comprising a range selection operation unit 110 to which a range selection operation by a user is input and a range switching control unit 101 for controlling an actuator that drives a range switching mechanism that switches the range of a transmission according to the state of the range selection operation unit comprises: a lock mechanism 113 for switching between an unlock state that makes the range selection operation unit operable and a lock state that makes the range selection operation unit inoperable, and a lock mechanism control unit 102 for shifting the lock mechanism from the unlock state to the lock state in response to the switching operation from a first range that unlocks the lock mechanism to a second range that locks the lock mechanism in the range selection operation unit.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a shift lock device that locks a range selection operation unit in a shift-by-wire transmission. [Background technology]

[0002] 2. Description of the Related Art Automatic transmissions installed in vehicles such as automobiles switch between a parking range, a reverse range, a neutral range, and a drive range in response to a range selection operation by a driver. In the past, it was common to link and interlock a range selection operation device such as a shift lever (select lever) with a manual valve (spool valve) provided on the transmission body by mechanical means such as a Bowden wire. In recent years, however, shift-by-wire systems, in which the range selection operation device and the transmission body are not mechanically linked but range selection is performed by electrical signals, etc., are becoming more common.

[0003] As an example of a conventional technique related to such a shift-by-wire transmission, Patent Document 1 describes a shift-by-wire range switching control device that, when switching the range position past the N range position, performs anticipatory control to start switching to the N range position when the N range position is detected. Patent document 2 describes setting the next shift position located in a driving direction set based on the current shift position as a target shift position, and outputting a shift actuator drive signal according to the target shift position set from the current shift position. Patent Document 3 describes a shift-by-wire automatic transmission in which a lock lever for locking a select lever in a parking lock position is connected to a transmission actuator via an operating cable and a turning lever. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-2561 A [Patent Document 2] JP 2002-349703 A [Patent Document 3] Special Publication No. 2010-520423 Summary of the Invention [Problem to be solved by the invention]

[0005] Shift-by-wire transmissions are provided with a shift lock mechanism that mechanically locks a range selection operation unit to prohibit range selection operation (shift operation). For example, when the range selection operation unit has selected the parking range, the system is configured to transition from the locked state to the unlocked state only when the brakes are operated, in order to prevent the vehicle from erroneously starting off due to an unintended shift into the driving range. However, in a shift-by-wire transmission, if the shift lock mechanism is activated after the shift operation from another range to the parking range and the range switching operation of the transmission is performed by the actuator, for example, if a shift operation to another range is performed immediately after a shift operation to the parking range, there is a concern that the parking range will not be locked and a shift operation to another range will be performed, which should actually be prohibited. In view of the above-mentioned problems, an object of the present invention is to provide a shift lock device that transitions to a locked state at an appropriate timing. [Means for solving the problem]

[0006] The present invention solves the above-mentioned problems by the following solving means. The invention according to claim 1 provides a shift lock device provided in a shift-by-wire system including a range selection operation unit to which a range selection operation by a user is input, and a range switching control unit that controls an actuator that drives a range switching mechanism that switches the range of a transmission in accordance with a state of the range selection operation unit, the shift lock device including a lock mechanism that switches between an unlocked state in which the range selection operation unit is operable and a locked state in which the range selection operation unit is inoperable, and a range switching control unit that switches the lock mechanism in accordance with a range selection operation unit that switches between an unlocked state in which the range selection operation unit is operable and a locked state in which the range selection operation unit is inoperable, the range selection operation unit being configured to switch between a first range in which the lock mechanism is unlocked and a second range in which the lock mechanism is locked. and a lock mechanism control unit that transitions the unlocked state to the locked state, wherein the range switching control unit, after a switching operation to the second range is performed at the range selection operation unit, determines a target drive end position that is a target for the range of the transmission by the range switching mechanism driven by the actuator, and then starts an operation of switching the range of the transmission by the range switching mechanism to the target drive end position by driving the actuator, and the lock mechanism control unit, after determining the target drive end position by the range switching control unit, starts a transition of the lock mechanism from the unlocked state to the locked state in accordance with the determination of the target drive end position. The transition of the locking mechanism is completed before the actuator starts to operate. The shift lock device is characterized in that According to this, by transitioning the locking mechanism to a locked state in response to a switching operation from the first range, which is unlocked, to the second range, which should be locked, the range selection operation unit can be immediately locked without waiting for the operation of the range switching mechanism. This improves safety by preventing accidental switching to another range immediately after the second range switching operation has been performed. By transitioning the lock mechanism from the unlocked state to the locked state without waiting for the completion of range switching of the transmission mechanism by the actuator, the above-mentioned effects can be reliably obtained. Effect of the Invention

[0008] As described above, according to the present invention, it is possible to provide a shift lock device that transitions to a locked state at an appropriate timing. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a schematic configuration of a transmission control system having a first embodiment of a shift lock device to which the present invention is applied. [Diagram 2] 2 is a schematic diagram showing a configuration of a lock mechanism in the shift lock device of the first embodiment. FIG. [Diagram 3] 4 is a flowchart showing a schematic diagram of control during range switching in a transmission having a shift lock device of the first embodiment. [Figure 4] 5 is a flowchart showing a control process performed during range switching in a transmission having a shift lock device as a comparative example of the present invention. [Diagram 5] FIG. 4 is a sequence diagram showing the operation at the time of range switching in the shift lock device of the first embodiment and the comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First Embodiment Hereinafter, a first embodiment of a shift lock device to which the present invention is applied will be described. The shift lock device of the first embodiment is provided in a shift-by-wire device that switches the driving range of an automatic transmission mounted in an automobile such as a passenger car. FIG. 1 is a block diagram that shows a schematic configuration of a control system for a transmission having a shift lock device according to a first embodiment.

[0011] In the first embodiment, a transmission 1 including a gearbox is, for example, a chain-type CVT, and has an AWD transfer that transmits driving force to front and rear wheels. The transmission 1 includes a speed change mechanism 10, a lock-up clutch 20, a transfer clutch 30, a forward clutch 40, a reverse brake 50, a control valve 60, a spool valve 70, a parking lock mechanism 80, and the like.

[0012] The transmission mechanism 10 reduces or increases the speed of input rotation from an engine (not shown). The transmission mechanism 10 may be, for example, a variator of a chain-type continuously variable transmission (CVT) having a primary pulley and a secondary pulley that rotate around parallel axes, and a chain stretched between them. Each pulley has a fixed sheave that clamps the chain and a movable sheave, and by changing the hydraulic balance of the chamber provided on the back side of the movable sheave, the sheave spacing is changed, thereby controlling the winding diameter of the chain and changing the speed.

[0013] The lock-up clutch 20 is a frictional engagement element that restricts relative rotation (torque converter slip) between an input portion (impeller) and an output portion (turbine) of a torque converter provided between the engine and the transmission mechanism 10.

[0014] The transfer clutch 30 is a frictional engagement element that is provided between the output side of the transmission mechanism unit 10 and the rear wheel drive system, for example in the case of an AWD (all wheel drive) system in which the front wheel drive system is directly connected to the transmission mechanism unit 10, and changes the transmitted torque. The transfer clutch 30 is used to control the distribution of driving force between the front and rear wheels in the AWD system according to the vehicle state.

[0015] The forward clutch 40 and the reverse brake 50 are friction engagement elements provided in a forward / reverse switching mechanism that switches the vehicle between a forward state (corresponding to the drive range) and a reverse state (corresponding to the reverse range). The forward / reverse switching mechanism is configured to have, for example, a planetary gear set, and is disposed on the output side or the input side of the transmission mechanism 10. The forward clutch 40 is engaged to transmit driving force when the vehicle is moving forward (in the drive range). At this time, the reverse brake 50 is disengaged. The reverse brake 50 is engaged when the vehicle is moving backward (in the reverse range) to transmit driving force, while the forward clutch 40 is disengaged. In addition, the forward / reverse switching mechanism can be placed in a state in which no power transmission is performed (when in the parking range or neutral range) by disengaging both the forward clutch 40 and the reverse brake 50.

[0016] The control valve 60 is a pressure adjusting valve that controls the hydraulic pressure supplied to each of the above-mentioned components in response to a command from a transmission control unit (TCU) 100. The control valve 60 has a function of adjusting the pressure of oil pressurized and pumped from an oil pump (not shown) to a predetermined pressure and supplying the oil to each section.

[0017] The spool valve 70 is a range switching mechanism that switches the oil path that supplies hydraulic pressure from the control valve 60 to the forward clutch 40 and the reverse brake 50, and switches between a forward state (drive range) in which the forward clutch 40 is engaged, a reverse state (reverse range) in which the reverse brake 50 is engaged, and a neutral state (neutral range or parking range) in which both the forward clutch 40 and the reverse brake 50 are released.

[0018] The spool valve 70 has a motor 71 . The motor 71 is an electric actuator that switches the state of the spool valve 70 in response to a command from the TCU 100, and switches between the forward state, reverse state, and neutral state described above.

[0019] The parking lock mechanism 80, in response to a command from the TCU 100, mechanically restricts (locks) the rotation of the output shaft of the transmission 1 when the parking range is selected, thereby preventing the vehicle from starting to move.

[0020] The transmission 1 has a TCU 100. The TCU 100 is a control device that comprehensively controls the transmission 1 and its accessories based on the driving state of the vehicle and the like. The TCU 100 is configured to include, for example, an information processing unit such as a CPU, a storage unit such as a RAM or a ROM, an input / output interface, and a bus connecting these.

[0021] The TCU 100 includes a shift-by-wire control unit 101 and a shifter control unit 102 . The shift-by-wire control unit 101 issues commands to the control valve 60, the motor 71 of the spool valve 70, and the parking lock mechanism 80 to control the gear ratio in the transmission mechanism 10, the fastening force of each friction engagement element, the output shaft angular position of the motor 71, the engagement or release of the parking lock mechanism 80, etc. The shift-by-wire control unit 101 functions as a range switching control unit of the present invention. The shifter control unit 102 is connected to a range shifter 110, which will be described later, determines the state of the range shifter 110, transmits the determination result to the shift-by-wire control unit 101, and controls a lock mechanism 113, which will be described later.

[0022] A brake switch 103 and a vehicle speed sensor 104 are connected to the TCU 100 directly or indirectly via other units. The brake switch 103 is a switch that detects the state of depression of a brake pedal (not shown) that is used by the driver to perform a braking operation. The vehicle speed sensor 104 generates a signal with a frequency corresponding to the rotation speed of a hub to which a wheel is attached. Based on the output of the vehicle speed sensor 104, the running speed of the vehicle (vehicle speed) can be calculated.

[0023] The range shifter 110 is connected to the TCU 100 . The range shifter 110 is provided, for example, in a cabin (vehicle interior) of the vehicle, and serves as a range selection operation unit through which a user, such as a driver, inputs a range selection operation for the transmission 1.

[0024] The range shifter 110 includes a dial 111, a shifter position sensor 112, and the like. The dial 111 is an operating member with which the user performs a range selection operation. The dial 111 is formed, for example, in a disk shape and is rotatable around its central axis. The dial 111 is configured to sequentially select a parking range P, a reverse range R, a neutral range N, and a drive range D when rotated counterclockwise, for example, according to the angular position around the central axis.

[0025] The parking range P is the range selected when the vehicle is parked. In the parking range P, the spool valve 70 closes the oil passages from the control valve 60 to the forward clutch 40 and the reverse brake 50, and the parking lock mechanism 80 is set to a locked state.

[0026] Reverse range R is the range selected when the vehicle is moving backwards. In the reverse range R, the spool valve 70 opens the oil passage to the reverse brake 50 and closes the oil passage to the forward clutch 40, so that the parking lock mechanism 80 is in an unlocked state (released state).

[0027] Neutral range N is the range selected when the vehicle is temporarily stopped. In the parking range P, the spool valve 70 closes the oil passages from the control valve 60 to the forward clutch 40 and the reverse brake 50, and the parking lock mechanism 80 is set to an unlocked state.

[0028] Drive range D is the range selected when the vehicle is moving forward. In drive range D, the spool valve 70 opens the oil passage to the forward clutch 40 and closes the oil passage to the reverse brake 50, and the parking lock mechanism 80 is set to an unlocked state (released state).

[0029] The shifter position sensor 112 has an encoder that detects the angular position of the dial 111 . The output of the shifter position sensor 112 is transmitted to the TCU 100 .

[0030] The range shifter 110 is provided with a locking mechanism 113 that locks the dial 111 at a predetermined angular position. FIG. 2 is a schematic diagram showing the configuration of a lock mechanism in the shift lock device of the first embodiment. The lock mechanism 113 includes a lock pin 113a and a solenoid 113b. Lock pin 113a is a columnar member that locks the rotation of dial 111 by being inserted into engagement holes 114, 115 formed on one side of dial 111 (the surface opposite the user side, the bottom surface in FIG. 2). The solenoid 113b is an electric actuator that transitions between a locked state in which the lock pin 113a is extended toward the dial 111 and inserted into the engagement holes 114, 115, and an unlocked state in which the lock pin 113a is retracted and separated (removed) from the engagement holes 114, 115. The operation of the solenoid 113b is controlled by the shifter control unit 102 of the TCU 100. The shifter control unit 102 functions as a lock mechanism control unit according to the present invention.

[0031] The dial 111 is formed with engagement holes 114 and 115 as the above-mentioned engagement holes. The engagement hole 114 is disposed in a positional relationship such that, when the parking range P is selected by the dial 111, the lock pin 113a can be inserted therein. For example, when the parking range P is selected, the lock pin 113a is inserted into the engagement hole 114, and the dial 111 is locked, thereby preventing an erroneous selection of another range. For example, when the brake switch 103 detects a brake operation by the driver, the lock pin 113a is pulled out of the engagement hole 114, and the lock mechanism 113 transitions from a locked state to an unlocked state. This allows the driver to select another range.

[0032] The engagement hole 115 is disposed in a positional relationship such that, when the neutral range N is selected by the dial 111, the lock pin 113a can be inserted therein. For example, if the dial 111 is erroneously rotated toward the reverse range R while the vehicle is traveling forward in drive range D (the vehicle speed sensor 104 detects the vehicle speed), when the dial 111 reaches a position corresponding to the neutral range N, the lock pin 113a is inserted into the engagement hole 115, the dial 111 is locked, and the reverse range R is prevented from being selected. In addition, when the vehicle is traveling backwards in reverse range R (vehicle speed sensor 104 detects the vehicle speed), if dial 111 is erroneously rotated toward drive range D, when dial 111 reaches a position corresponding to neutral range N, lock pin 113a is inserted into engagement hole 115, locking dial 111 and preventing drive range D from being selected.

[0033] FIG. 3 is a flow chart that illustrates control during range switching in the transmission having the shift lock device of the first embodiment. Each step will be explained in order below. <Step S01: Determine target range position> The shift-by-wire control unit 101 of the TCU 100 determines a target range position that is a target when a range selection operation is performed and switching is to be performed, based on the state (position) of the dial 111 acquired from the range shifter 110 via the shifter control unit 102. Thereafter, the process proceeds to step S02 and, in parallel, to step S04.

[0034] <Step S02: Motor drive> The shift-by-wire control unit 101 calculates the drive amount of the motor 71 required to switch to the target range determined in step S01, and drives the motor 71 based on the calculation result. This initiates switching of the state of the spool valve 70. Then, proceed to step S03.

[0035] <Step S03: Actual range switching> When the motor 71 operates by the drive amount set in step S02, the state of the spool valve 70 switches, and the range actually (mechanically) selected in the transmission 1 coincides with the target range determined in step S01. Then, the series of processes ends.

[0036] <Step S04: Shift lock / unlock determination> The shifter control unit 102 of the TCU 100 determines whether the lock mechanism 113 should be locked or unlocked in the target range determined in step S01. For example, when the target range is the parking range P, it is determined that the vehicle should be locked except when the brakes are being operated. Also, if the target range becomes the neutral range N while the vehicle is traveling forward in the drive range D or while the vehicle is traveling backward in the reverse range R, it is determined that the vehicle should be locked. Then, proceed to step S05.

[0037] <Step S05: Shift lock mechanism solenoid drive> The shifter control unit 102 of the TCU 100 drives the solenoid 113b of the lock mechanism 113 in accordance with the result of the determination in step S04. For example, when a locked state is to be established, the lock pin 113a is driven in the extension direction by the solenoid 113b. As a result, when the lock pin 113a faces either the engagement hole 114 or 115, it is inserted therein, and the lock mechanism 113 transitions to a locked state. Then, the series of processes ends.

[0038] The effects of the first embodiment will be described in comparison with a shift lock device of a comparative example of the present invention, which will be described below. In the comparative example and the second embodiment described later, the same reference numerals are used for the parts common to the first embodiment described above, and the description will be omitted, and the differences will be mainly described. FIG. 4 is a flow chart that illustrates control during range switching in a transmission having a shift lock device that is a comparative example of the present invention. In the figure, steps S11 to S15 are performed in the same manner as steps S01 to S05 in the first embodiment, but in the comparative example, after the switching of the actual range (state transition of the spool valve 70) is completed in step S13, a shift lock / unlock determination is made in step S14, and the solenoid is driven in step S15.

[0039] FIG. 5 is a sequence diagram showing the operation at the time of range switching in the shift lock device of the first embodiment and the comparative example. In the comparative example, a determination is made as to whether or not the lock mechanism 113 needs to be locked and the solenoid 113b is driven after the switching of the spool valve 70 inside the transmission 1 is completed, so the timing at which the lock mechanism 113 is locked is delayed compared to the first embodiment. For this reason, for example, if the driver switches from reverse range R to parking range P and then immediately attempts to switch back from parking range P to reverse range R, the range should normally be locked in parking range P and the selection of reverse range R should be prohibited, but because the locking operation is delayed, the range ends up being switched to reverse range R.

[0040] In contrast, according to the first embodiment, in response to a switching operation from reverse range R, in which the lock mechanism 113 is unlocked, to parking range P, in which the lock mechanism 113 should be locked, the solenoid 113b is driven in parallel with the driving of the motor 71 inside the transmission 1 to transition the lock mechanism 113 to a locked state, thereby immediately locking the dial 111 of the range shifter 110 without waiting for the completion of range switching in the spool valve 70. This prevents erroneous switching to another range immediately after switching to the reverse range R, thereby improving safety.

[0041] <Second embodiment> Next, a second embodiment of a shift lock device to which the present invention is applied will be described. In the first embodiment, the driving of the spool valve 70 by the motor 71, the shift lock / unlock determination, and the driving of the solenoid 113b are performed in parallel at the same time. However, in the second embodiment, after the target range position is determined, the shift lock / unlock determination and the driving of the solenoid 113b are first performed, and then the driving of the motor 71 is started. The second embodiment described above can also provide the same effects as those of the first embodiment described above.

[0042] (Modification) The present invention is not limited to the above-described embodiments, and various modifications and variations are possible, which are also within the technical scope of the present invention. (1) The configurations of the vehicle, the transmission, and the shift-by-wire device are not limited to the above-described embodiments, and may be modified as appropriate. (2) In each embodiment, the range selection operation unit has a dial-shaped operation unit as an example, but the configuration of the range selection operation unit can be changed as appropriate. For example, the operation unit may be a lever-shaped operation unit or may have other configurations. (3) In each embodiment, the range selection operation unit can be locked at multiple positions by inserting a single lock pin and solenoid into multiple engagement holes, but multiple independent lock mechanisms may be provided according to the multiple positions to be locked. The configuration of the lock mechanism is not limited to that of the embodiment, and the range selection operation unit may be locked by, for example, a claw-shaped engaging member or other means. [Explanation of symbols]

[0043] 1 Transmission 10 Speed ​​change mechanism 20 Lock-up clutch 30 Transfer clutch 40 Forward clutch 50 Reverse brake 60 Control valve 70 Spool valve 71 Motor 80 Parking lock mechanism 100 Transmission Control Unit (TCU) 101 shift-by-wire control unit 102 shifter control unit 103 Brake switch 104 Vehicle speed sensor 110 Range shifter 111 Dial 112 Shifter position sensor 113 Locking mechanism 113a Lock pin 113b Solenoid 114,115 Engagement hole

Claims

[Claim 1] A range selection operation unit to which a range selection operation by a user is input; a range switching control unit that controls an actuator that drives a range switching mechanism that switches the range of a transmission in accordance with a state of the range selection operation unit; A shift lock device provided in a shift-by-wire device comprising: a lock mechanism for switching between an unlocked state in which the range selection operation unit is operable and a locked state in which the range selection operation unit is inoperable; a lock mechanism control unit that transitions the lock mechanism from the unlocked state to the locked state in response to a switching operation from a first range in which the lock mechanism is in an unlocked state to a second range in which the lock mechanism is in a locked state, in the range selection operation unit, the range switching control unit, after a switching operation to the second range is performed at the range selection operation unit, determines a target drive end position that is a target for the range of the transmission by the range switching mechanism driven by the actuator, and then starts an operation of switching the range of the transmission by the range switching mechanism to the target drive end position by driving the actuator; After the range switching control unit determines the target drive end position, the lock mechanism control unit starts a transition of the lock mechanism from the unlocked state to the locked state in response to the determination of the target drive end position, and completes the transition of the lock mechanism before the actuator starts to operate. A shift lock device comprising:

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