JP2013060137A - Electric steering lock control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely perform lock operation and lock releasing operation of electric steering, by eliminating a state of not accepting the lock releasing operation, even if a rest swing state of the steering is caused, by using an actuator such as an inexpensive motor being low in heat resistance having no overheat protective function.SOLUTION: When a repetitive frequency of the lock releasing operation does not exceed a predetermined set frequency within a predetermined set time (9 sec) after a push start switch 5 is pushed (a predetermined operation start), a steering lock control part 6 controls a current-carrying time to the motor 7 so as to become a first time T1, and when the repetitive frequency of the lock releasing operation exceeds the set frequency in the set time, the current-carrying time to the motor 7 is controlled in a second time T2 (<T1) shorter than the first time T1 in a switching system.

Description

  The present invention relates to an electric steering lock control device that locks and unlocks electric steering by operating an actuator such as a motor.

  2. Description of the Related Art Conventionally, a vehicle having a so-called smart entry (key-free) function that can open and close a door and start an engine by wireless communication between a portable device carried by a driver and an in-vehicle device employs an electric steering.

  In this type of electric steering lock control device, when the engine is stopped and the driver gets off, the lock operation is performed when the driver gets on and the lock is released when the engine starts and the engine is started. The motor is driven to rotate in the forward and reverse directions according to the unlocking operation, the rotation of the motor is converted into a linear movement of the lock pin by the screw mechanism, and its tip is engaged with a recess formed in the peripheral surface of the steering shaft of the electric steering. When the vehicle is parked and the like, the lock pin is engaged with the recess to lock the electric steering, and when riding, the lock pin is disengaged from the recess and the electric steering is unlocked.

  Furthermore, in order to protect the steering lock motor, the conventional electric steering lock control device estimates the pseudo temperature of the motor, and stops driving the motor when the estimated temperature exceeds a predetermined threshold value. (See paragraphs 0008, 0011, 0031 and FIG. 3 of Patent Document 1).

  Further, when the calculated value obtained from the relational expression having the operation time of the steering lock motor (actuator) as an element is larger than a predetermined pause threshold, the steering lock motor (actuator) is forcibly stopped to lock the steering lock. There is also an electric steering lock control device that protects a motor (actuator) (see paragraphs 0008 and 0012 of FIG. 2 and FIG. 2).

JP 2005-162114 A JP 2004-217002 A

  However, depending on the steering operation angle at the time of parking, the lock pin is engaged obliquely with respect to the recess of the steering shaft and the lock pin is caught on the opening side edge of the recess (that is, the stationary state) In such a stationary state, even if the steering lock motor is actuated by the unlocking operation, the lock pin bites into the opening edge of the recess and does not come out smoothly from the recess. A phenomenon occurs.

  In such a case, in the electric steering lock control device described in Patent Document 1, the unlocking operation is repeated, the motor temperature immediately rises to the threshold value, the motor stops, and then the driver locks. Even if the release operation is performed, the motor does not operate, and the driver may not be able to release the lock.

  Further, even in the electric steering lock control device described in Patent Document 2, while the driver repeats the unlocking operation, the calculated value reaches the suspension threshold and the motor is forcibly stopped. Therefore, even if the driver performs the unlocking operation, the motor Does not work, and the driver determines that a motor failure has occurred. In particular, when used in a low temperature environment such as a cold region, the calculated value reaches the pause threshold even if the motor's allowable temperature limit has not been reached, causing a situation where the motor is forcibly stopped and cannot be unlocked. There is also.

  The present invention uses an actuator such as an inexpensive motor with low heat resistance that does not have an overheat protection function, eliminates a situation in which a lock release operation is not accepted even when a steering stationary state occurs, The purpose is to enable the unlocking operation.

  In order to achieve the above-described object, an electric steering lock control device of the present invention includes an actuator that performs a lock operation and a lock release operation of a steering by switching a position of a lock pin engaged with and disengaged from a steering shaft of the electric steering, and a lock operation. And an electric steering lock control device comprising a control means for controlling the operation of the actuator by a predetermined operation for the unlocking operation, wherein the control means is predetermined from the start of the predetermined operation for the unlocking operation. If the number of repetitions of the unlocking operation does not exceed a predetermined number of times within a set time, the actuator operating time is controlled to a first time, and the set time from the start of the predetermined operation The number of repetitions of the unlocking operation exceeds the set number of times Case is characterized by the switching control of the operating time of the actuator at a second time shorter than said first time (claim 1).

  Further, the control means may provide a predetermined pause period during which the actuator is not in an operating state between the operation of the actuator and the next operation.

  According to the first aspect of the present invention, when the control means causes the actuator to be activated when the number of repetitions of the unlocking operation does not exceed the predetermined set number of times within a predetermined set time from the start of the predetermined operation. When the time is controlled to the first time and the number of repetitions of the unlocking operation exceeds the set number of times within the set time from the start of the predetermined operation, the second time in which the operation time of the actuator is shorter than the first time Is controlled to be switched.

  Therefore, even if an inexpensive motor with low heat resistance that does not have an overheat protection function using a positive temperature coefficient thermistor is used for the actuator, the temperature of the actuator (for example, the motor) can be maintained even when the unlocking operation continues. In addition, it is possible to keep the temperature below the saturation temperature that satisfies the life time, which is determined by the energization time, and it is possible to reduce costs, and even if the steering is stationary, it is locked as before. Steering locking and unlocking operations can be reliably performed without causing a situation in which an operation for releasing is not accepted.

  According to the second aspect of the present invention, since a predetermined pause period is provided between the operation of the actuator and the next operation, the increase in the temperature rise of the actuator (for example, the motor) can be suppressed, and the actuator It becomes possible to protect reliably.

It is a block diagram of one embodiment of an electric steering lock control device of the present invention. It is explanatory drawing of the electric steering lock mechanism which operate | moves with the motor of FIG. It is a flowchart for operation | movement description. It is a timing chart for operation explanation.

  Next, an embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a block diagram of an electric steering lock control device mounted on a vehicle 1 having a so-called smart entry (key-free) function.

  Then, the smart entry function will be described. When the driver carries the portable device 2 and gets close to the vehicle 1 and presses the door switch 3, the key-free control unit (key-free ECU) having the microcomputer configuration and the portable device 2 is pressed. ) When the information is exchanged with 4 and the registered portable device 2 is correct, a door lock mechanism (not shown) unlocks the door of the vehicle 1 under the control of the key-free control unit 4.

  Then, when the driver gets on the vehicle 1 with the portable device 2 and the driver presses the push start switch 5 while stepping on the brake pedal, the key-free control unit 4 controls the microcomputer-configured steering lock control unit (steering lock ECU). The lock release command is sent to 6 and the electric steering is unlocked by the lock release control of the steering lock control unit 6. Here, the operation of pushing the push start switch 5 when the driver gets on corresponds to a predetermined operation for unlocking the electric steering in the present invention.

  Thereafter, when the electric steering is unlocked, the key-free control unit 4 sends an engine start permission to the engine control unit and the like via an in-vehicle communication network such as LIN (not shown), and the engine of the vehicle 1 is started. .

  When the driver depresses the push start switch 5 while the engine is running, the engine is stopped (engine off) by the engine control unit, and then the driver opens the door when carrying the portable device 2 to get off. When the courtesy switch is turned on, a lock command is sent from the key-free control unit 4 to the steering lock control unit 6, and the electric steering is locked by the steering lock control unit 6. Here, the operation of opening the door when the driver gets off (the trigger of the lock command) corresponds to the predetermined operation for locking the electric steering in the present invention. The trigger for the lock command may be a case where the door is opened before the engine is turned off, or a case where the door is closed after the engine is turned off.

  Further, after the driver gets off with the portable device 2 and presses the door switch 3, the door is locked by the door lock mechanism under the control of the key-free control unit 4, thereby preventing theft during parking.

  Next, the control operation of locking and unlocking the electric steering by the steering lock control unit 6 will be described.

  A power supply drive unit 8 that supplies power to and stops power supply to the electric steering lock DC motor 7 that is an actuator of the present invention is provided with a lock relay 8a and a lock release relay 8b, and ground terminals 8ae and 8be are respectively energized. From the side to the power supply terminals 8ab and 8bb.

  More specifically, first, at the time of lock control, a high-level lock control signal is output from the steering lock control unit 6 to the base of the NPN type locking transistor 8a1 in order to energize the lock relay 8a of the power supply drive unit 8. The transistor 8a1 is turned on, the relay coil 8a2 of the lock relay 8a is energized, and the lock relay 8a is switched to the power supply terminal 8ab side. At this time, the base of the unlocking transistor 8b1 is at a low level.

  When the lock relay 8a is switched to the power supply terminal 8ab, the motor current flows through the path from the in-vehicle battery 9 to the fuse 10, the power supply terminal 8ab of the lock relay 8a, the motor 7, and the ground terminal 8be of the lock release relay 8b. Rotates in the locking direction.

  FIG. 2 shows an electric steering lock mechanism of the vehicle 1. A tube-like steering shaft 11 a that pivotally supports the steering 11 has a recess 12 formed at an appropriate position and is connected to an assist motor (not shown). It is connected to the left and right wheels via a gear box or the like, and an electric steering is formed by their configuration.

  For example, one gear 14 of a worm gear structure of a screw mechanism portion 13 is attached to the rotating shaft of the motor 7, and a cylindrical body having an internal thread formed on one end face of the other gear 15 meshing with the gear 14. An internal thread portion 16 is provided integrally, and the internal thread portion 16 is rotated by the motor 7.

  A base portion of a columnar cam 17 is inserted inside the female screw portion 16, and the male screw of this base portion is engaged with the female screw of the female screw portion 16, and the cam 17 approaches the steering shaft 11 a side by forward and reverse rotation of the female screw portion 16. And the linear movement in the direction away from the steering shaft 11a. A lock pin 18 is connected to the distal end portion of the cam 17, and the end surface portion of the lock pin 18 is brought into contact with and separated from the concave portion 12 by such a linear movement of the cam 17. Note that reference numeral 19 in FIG. 2 denotes a part of the electric steering lock mechanism main body, and an insertion slot for the lock pin 18 and the like are formed.

  At the time of lock control, the motor 7 rotates in the lock direction, so that the lock pin 18 enters the recess 12 and the end surface is in contact with the recess 12 and is locked so that the steering 11 cannot rotate.

  On the other hand, at the time of unlock control, a high level unlock control signal is output from the steering lock controller 6 to the base of the NPN type unlock transistor 8b1 to energize the unlock relay 8b of the power supply drive unit 8. The transistor 8b1 is turned on, the relay coil 8b2 of the unlock relay 8b is energized, and the unlock relay 8b is switched to the power supply terminal 8bb side. At this time, the base of the locking transistor 8a1 is at a low level.

  When the unlocking relay 8b is switched to the power supply terminal 8bb, the motor current flows through the path from the in-vehicle battery 9 to the fuse 10, the power supply terminal 8bb of the unlocking relay 8b, the motor 7, and the ground terminal 8ae of the lock relay 8a. 7 rotates in the unlocking direction (separating direction) opposite to the locking direction (approaching direction).

  As the motor 7 rotates in the unlocking direction, the end face of the lock pin 18 is pulled away from the slot 12 and the steering 11 can rotate during normal operation when the screw mechanism 13 operates normally. .

  If any abnormality occurs in the power feeding drive unit 8 of the motor 7, the power supply monitoring unit 20 shown in FIG. 1 prohibits the engine starting with the electric steering locked. The voltage on the 8a side and the unlocking relay 8b side are monitored. Further, for example, the lock sensor 22a and the lock release sensor 22b of FIG. 1 formed by Hall sensors detect engagement / disengagement of the lock pin 18 with respect to the recess 12 respectively.

  By the way, it is common for the motor 7 to take measures against overheating by continuous energization. Conventionally, for example, a positive temperature coefficient thermistor is arranged close to the motor, and the resistance value increases due to the temperature rise of the thermistor as the motor temperature rises. Although it has been practiced to provide a function of shutting off energization to the motor and protecting the motor from overheating, there is a disadvantage that the cost of the motor is increased by providing a thermistor. In order to eliminate such inconvenience, in the present invention, a locking operation and an unlocking operation of the electric steering can be performed using a low-heat-resistant and low-cost motor that does not have an overheat protection function such as a positive temperature coefficient thermistor. Therefore, energization control of the motor 7 is performed with the following configuration.

  The key-free control unit 4 shown in FIG. 1 counts a first timer including a counter constituting a 2.4-second timer, a second timer based on a counter constituting a 9-second timer, and the number C of repetitions of unlocking operation. And an operation counter. The first timer and the second timer repeatedly start timing when energization of the motor 7 is started (start of a predetermined operation), and end timing when energization of the motor 7 is started next time. The operation counter counts up or is reset when the set time Ts described later elapses.

  Then, after the push start switch 5 is pressed (the start of a predetermined operation, that is, the start of energization of the motor 7), the time T of the second timer is within 9 seconds which is a predetermined set time Ts, If the number C of repetitions of the unlocking operation counted by the operation counter within 9 seconds does not exceed a predetermined number of times Cmax, for example, two, the operation time of the motor 7 for the unlocking operation is set. The energization time to the motor 7 by the steering lock control unit 6 to be determined is controlled to 1.0 second which is the first time T1. At this time, when it was experimentally derived that the optimum time for the motor 7 not to reach the temperature at which the motor 7 reaches the service life, that is, the optimum time for the saturation temperature not to be reached, it was found to be 9 seconds. This is a set time Ts by two timers. In general, when the saturation temperature is high, the life of the motor is shortened. Therefore, it is desirable to set the saturation temperature to be low, and the present invention performs control at the lowest possible saturation temperature.

  On the other hand, after the push start switch 5 is pushed (predetermined operation start), the time T measured by the second timer is within 9 seconds, which is a preset set time Ts, and is unlocked counted by the operation counter. When the number of repetitions C of the operation exceeds “2”, which is the set number Cmax, to the motor 7 by the steering lock control unit 6 that determines the operation time of the motor 7 for the third and subsequent unlocking operations. Is controlled to 0.5 second, which is a second time T2 (<T1) shorter than the first time T1. Such a switching control function of the energization time to the motor 7 by the steering lock control unit 6 corresponds to the control means in the present invention.

  Further, the repetition time Δt of the unlocking operation is a time (= 0.1 second) in consideration of the wake-up time (<0.1 second) of the microcomputer of the in-vehicle communication network such as LIN described above after the push start switch 3 is pressed. ) And 2.4 seconds by the first counter of the key-free control unit 4 is set to 2.5 seconds, and the repetition time Δt (= 2.5 seconds) by the first timer of the key-free control unit 4 Is measured, and a predetermined pause period during which the motor 7 is not operated is provided between one unlocking operation and the next unlocking operation. Therefore, as long as the suspension period does not elapse, even if the push start switch 5 is pressed as an unlocking operation by the driver, the operation of the push start switch 5 is not accepted and becomes invalid. The operation is accepted effectively.

  Specifically, the rest period during which the energization time to the motor 7 is controlled to the first time (= 1.0 second) is 1.5 seconds, and the energization time to the motor 7 is the second time ( = 0.5 seconds), the pause period is 2.0 seconds.

  Further, as described above, in the so-called stationary state in which the lock pin 18 is engaged with the recess 12 of the steering shaft 11a while being inclined obliquely and the lock pin 18 is caught on the opening side edge of the recess 12, the lock pin 18 is locked. Even if the motor 7 is energized by the release operation, the lock pin 18 may not be detached from the recess 12. In such a case, the driver is informed that the lock cannot be released normally by one unlock operation. Therefore, the illumination control of the push start switch 5 is performed by an illumination control unit having a microcomputer configuration (not shown) so that the push start switch 5 that is normally lit in green blinks in green.

  Next, a control procedure for switching the energization time will be described with reference to the flowchart of FIG.

  When the driver unlocks and gets on the door of the vehicle 1 and pushes the push start switch 5 (predetermined operation start), as shown in FIG. 3, the time T measured by the second timer of the key-free control unit 4 is It is determined whether or not a predetermined set time Ts (= 9 seconds) has not been exceeded (step S1).

  If the time T does not exceed the predetermined set time Ts (= 9 seconds) and the determination result in step S1 is YES, the unlocking is counted by the operation counter of the key-free control unit 4. If "1" is added (counted up) to the number of repetitions C of the operation (step S2), and the measured time T exceeds the predetermined set time Ts (= 9 seconds), the determination result in step S2 is NO. The number C of repetitions of the unlocking operation counted by the operation counter is reset to “0” (step S3).

  Subsequently, when the processes in steps S2 and S3 described above are performed, the process proceeds to step S4, where the number of repetitions C of the unlocking operation counted by the operation counter exceeds a predetermined set number Cmax (= 2). (Step S4), if the number of repetitions C of the unlocking operation does not exceed the set number of times Cmax and the determination result of Step S4 is YES, the operating time of the motor 7 for the unlocking operation is The energization time to the motor 7 by the steering lock control unit 6 to be determined is controlled to 1.0 second which is the first time T1 (step S5).

  On the other hand, if the number of repetitions C of the unlocking operation exceeds the set number of times Cmax and the determination result in step S4 is NO, the steering lock controller 6 determines the operating time of the motor 7 for the unlocking operation to the motor 7 The energization time is controlled to 0.5 second which is the second time T2 (step S6), and after the processing of step S5 described above, the operation is terminated. 3 is executed every repetition time Δt (= 2.5 seconds) by the first timer of the key-free control unit 4 described above.

  As a result of the control shown in FIG. 3, the control timing of the energization time to the motor 7 is as shown in FIG. 4, and as shown in FIG. 4A, the repetition time Δt ( When the operation of the push start switch 5 is effectively accepted every 2.5 seconds), as shown in FIG. 5C from the start of the first unlocking operation until the set time Ts (= 9 seconds) is exceeded. On the other hand, when the number of repetitions C of the unlocking operation by the operation counter does not exceed the set number Cmax (= 2), the energization time to the motor 7 by the steering lock control unit 6 is as shown in FIG. On the other hand, the number of repetitions C of the unlocking operation by the operation counter C is controlled as shown in FIG. 5 (c) until the first time T1 (= 1.0 second) is controlled and the set time Ts of 9 seconds is exceeded Set up When the number of times Cmax (= 2) is exceeded, the third and subsequent energization times of the motor 7 are controlled to a second time (= 0.5 seconds) shorter than the first time T1. become.

  Therefore, according to the above-described embodiment, even if the motor 7 for electric steering lock is an inexpensive one with low heat resistance that does not have an overheat protection function by a positive temperature coefficient thermistor, even if the unlocking operation continues, the motor 7 is a saturation temperature determined by the energizing current and the energizing time and can be suppressed to a temperature that satisfies the lifetime, which can reduce the cost, and even if a stationary state occurs, The situation where the operation for unlocking is not accepted as in the conventional case does not occur, and the locking operation and unlocking operation of the steering wheel 11 can be reliably performed.

  In addition, since the repetition time Δt of the unlocking operation, which is the energization cycle of the motor 7, is set to 2.5 seconds, and a predetermined rest period is provided between the operation of the motor 7 and the next operation, the temperature of the motor 7 The degree of increase in the increase can be suppressed, and the motor 7 can be protected more reliably.

  Further, for example, after the motor 7 is activated by the energization for the first time T1 and the lock is successfully released by the second energization, the driver performs the locking operation within the set time Ts (= 9 seconds) after the energization. The unlocking operation performed by getting on again according to the above-described embodiment, even when an unusual operation such as performing the unlocking operation by opening the door and getting off the vehicle and performing the unlocking operation again is performed. Is determined as the third unlocking operation (continuous operation within 9 seconds), and the time T counted by the second counter does not exceed 9 seconds, which is the set time Ts, and the number of repeated unlocking operations C Exceeds the set number of times Cmax “2”, and as a result, the energization time of the motor 7 is controlled to a second time T2 (= 0.5 seconds) shorter than the first time T1. Therefore, the temperature of the motor 7 can be suppressed to a saturation temperature that is determined by the energization current and the energization time and satisfies the lifetime.

  In addition, the lighting of the push start switch 5 is controlled so that the push start switch 5 that is normally lit in green blinks to notify the driver. It can be known from the flashing of the push start switch 5 that a steering stationary state that cannot be performed has occurred.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, although the set time Ts has been described as 9 seconds, it is not particularly limited to 9 seconds, and the optimum time during which the motor 7 does not rise to the saturation temperature at which the motor 7 reaches the end of life is determined and obtained according to the operating temperature of the motor 7. Set to time.

  Further, the structure and block configuration of the electric steering lock mechanism of the electric steering lock control device are not limited to those of the above embodiment.

  Furthermore, the present invention can be similarly applied to an electric steering lock control device for a vehicle that does not have a smart entry (key-free) function.

  Further, in the above-described embodiment, in order to provide a predetermined pause period during which the motor 7 is not operated between one unlock operation and the next unlock operation, the unlock operation repeat time Δt. However, it is not limited to 2.5 seconds. Furthermore, it is not always necessary to provide such a rest period.

  The present invention can be applied to electric steering lock control provided with various vehicle motors and other actuators.

1 Vehicle 5 Push Start Switch 6 Steering Lock Control Unit 7 Motor 18 Lock Pin

Claims (2)

An actuator for performing a locking operation and a unlocking operation of the steering by switching a position of a lock pin engaged with and disengaging from a steering shaft of the electric steering, and a control means for controlling the operation of the actuator by a predetermined operation for the locking operation and the unlocking operation In the electric steering lock control device comprising
The control means includes
If the number of repetitions of the unlocking operation does not exceed the predetermined number of times within a predetermined set time from the start of the predetermined operation for the unlocking operation, the operating time of the actuator is set to the first Control in time
When the number of repetitions of the unlocking operation exceeds the set number of times within the set time from the start of the predetermined operation, the operation time of the actuator is switched to a second time shorter than the first time. An electric steering lock control device. In the electric steering lock control device according to claim 1,
The electric steering lock control device according to claim 1, wherein the control means provides a predetermined pause period during which the actuator is not in an operating state between the operation of the actuator and the next operation.

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