Vehicle door latch device

Abstract

To provide a vehicle door latch device having a standby power supply in such a manner of the standby power supply being configured to have little power loss and supplying power with high output and high efficiency.SOLUTION: A vehicle door latch device includes an operating unit driven by a motor, a control unit controlling the operation of the motor, a main power supply unit supplying power to the control unit and the motor, a standby power supply that supplies power in place of the main power supply unit in the event of a vehicle failure, a voltage boost unit that boosts a voltage of the standby power supply, a boost power supply line connecting the standby power supply to the control unit via the voltage boost unit, and a non-boosted power supply line connecting the operating unit and the standby power supply. In the vehicle door latch device, a drive control unit is provided between the control unit and the operating unit, which controls the drive operation of the operating unit in response to a signal from the control unit, and the drive control unit and the voltage boost unit are connected by the boost power supply line, so that the voltage of the standby power supply via the voltage boost unit is supplied in the event of the vehicle failure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a door latch device for a vehicle. [Background technology]

[0002] It is known that electric door latch devices are used in the doors of vehicles such as automobiles. Conventionally, electric door latch devices are configured to supply power to the door latch device installed in the door from a main power source installed in the vehicle via power supply wiring.

[0003] Meanwhile, door latch devices have been developed that are equipped with an emergency backup power supply using a supercapacitor in case power to the door latch device from the main power supply is cut off due to a vehicle accident or the like. For example, a door latch device according to this is described in JP 2016-503135 A. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2016-503135 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, supercapacitors used as backup power sources have a limited voltage that can be supplied, so a boost module is required to boost the voltage to provide enough voltage to drive the motor that locks or unlocks the door latch.

[0006] Furthermore, if a backup power supply is to be housed integrally within the door latch device installed in the vehicle door, it must be placed in a limited space, and the power supply capacity is also limited, making it difficult to obtain high output. [Means for solving the problem]

[0007] A vehicle door latch device according to one embodiment of the present invention has an operating unit driven by a motor, a control unit that controls the operation of the motor, a main power supply unit that supplies power to the control unit and the motor, a backup power supply unit that supplies power in place of the main power supply unit in the event of a vehicle failure, and a boost unit that boosts the voltage of the backup power supply unit, and the vehicle door latch device also has a boost power supply line that connects the backup power supply unit to the control unit via the boost unit, and a non-boosted power supply line that connects the operating unit and the backup power supply unit. [Effects of the Invention]

[0008] According to the vehicle door latch device of one embodiment of the present invention, it is possible to provide a door latch device that has little power loss in the booster section and can supply power with high output and high efficiency. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a vehicle door latch device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a vehicle door latch device according to another embodiment of the present invention. [Figure 3] FIG. 3 is a diagram illustrating a vehicle door latch device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that duplicated explanations of elements common to the various drawings may be omitted.

[0011] FIG. 1 is a diagram illustrating a vehicle door latch device according to one embodiment of the present invention.

[0012] 1 schematically illustrates a vehicle 100 and a vehicle door 110. The vehicle 100 is, for example, a vehicle such as an automobile, and the vehicle door 110 is fixed to the vehicle 100 via, for example, a door hinge so as to be able to be opened and closed.

[0013] The vehicle 100 has a main power supply unit 101 that supplies power to the vehicle door 110. Although not particularly limited, the main power supply unit 101 is configured using a storage battery such as a lead-acid battery that is widely used as an automobile battery. Furthermore, the main power supply unit 101 is capable of outputting a standard voltage for automobiles, for example, 12 V.

[0014] The door latch unit 111 disposed on the vehicle door 110 has an operating group 154 that includes, for example, a ratchet that can selectively rotate relative to a striker fixed to a door post, and a pawl that is rotationally driven by a motor and prevents the rotation of the ratchet. The motor 153 drives the operating group to lock and / or unlock the vehicle door 110.

[0015] The door latch unit 111 has an operating unit 150 including a motor 153, a driver 152 for driving the motor 153, and a pre-driver 151 (hereinafter, sometimes referred to as a second control unit).

[0016] The door latch unit 111 also has a control unit 130 that controls a driver 152 of the operating unit 150 and the like, and a power supply circuit unit 120 that supplies power from the main power supply unit 101 to the operating unit 150 and the control unit 130.

[0017] As will be described later, a motor that can be driven at approximately 3 V to 5 V is used as motor 153 so that it can be driven by the non-boosted voltage of backup power supply unit 161 in the event of a vehicle failure. Also, motor 153 needs to have sufficient output to rotate the ratchet.

[0018] During normal operation when the main power supply unit 101 supplies power, the main power supply supplies power to the driver 152 via the power line 102, the switching unit 121, and the power line 103. The switching unit 121 is a switch whose on / off state is controlled by the control unit 130. During normal operation, the switching unit 121 is in the on state. The switching unit 121 can be realized by, for example, a configuration in which power MOSFETs are connected back-to-back (common source connection).

[0019] Similarly, during normal operation when the main power supply unit 101 supplies power, the main power supply supplies power to the pre-driver 151 via the power supply line 104 .

[0020] The control unit 130 includes a central processing unit (CPU) that is configured by a microprocessor, for example, and the main power supply unit 101 also supplies power to the CPU 131.

[0021] Generally, a computing device such as a microprocessor requires a stable power supply for accurate operation. Furthermore, the power supply voltage of a large-scale integrated circuit (LSI) that constitutes a microprocessor tends to decrease as the integrated circuit becomes more miniaturized, and is often lower than the standard voltage for automobiles. Therefore, in this embodiment, a voltage regulator unit 122 is provided in the power supply circuit unit 120. The voltage of the main power supply unit 101 is stepped down to approximately 5 V by the voltage regulator unit 122, stabilized, and then supplied to the CPU 131.

[0022] The vehicle door 110 further includes a sensor unit 140. When a vehicle occupant or the like operates an operating handle to lock and / or unlock the vehicle door, the sensor unit 140 detects the operation and sends a detection signal to the CPU 131 of the control unit 130. Upon receiving the detection signal, the CPU 131 controls the pre-driver 151 and / or driver 152 of the actuation unit 150 to drive the motor 153, thereby locking and / or unlocking the vehicle door 110. The operating handle is a door latch switch that is used by the occupant or the like to lock and / or unlock the door, and includes both an outer handle installed on the outside of the vehicle 100 and an inner handle installed on the inside of the vehicle 100.

[0023] As described above, the main power supply unit 101 is expected to provide power at all times, but in an emergency such as a vehicle accident, the power supply from the main power supply unit 101 may be cut off or the power supply may be interrupted due to a power line break, etc. Therefore, the door latch unit 111 shown in Fig. 1 is provided with a backup power supply unit 160 for supplying power to the control unit 130 and / or the operating unit 150 in the event of a vehicle malfunction such as when the power supply from the main power supply unit 101 is interrupted.

[0024] The standby power supply 161 of the standby power supply unit 160 is configured using, for example, a supercapacitor (sometimes called an ultracapacitor). Note that the supercapacitor includes an electrolytic double layer capacitor, a pseudo capacitor, or a capacitor that is a combination of these.

[0025] By providing such a backup power supply unit 160, the operating unit 150 can be reliably operated even in the event of a vehicle accident in which the main power supply is cut off, and the locking or unlocking operation of the vehicle doors can be reliably ensured.

[0026] Supercapacitors have high energy density, high output current characteristics, and are relatively small in size, making them suitable as backup power sources for vehicle doors. However, they are limited in the voltage they can supply, and when installed inside a door latch device, they must be placed in a limited space, limiting their power supply capacity.

[0027] For these reasons, the maximum supply voltage of a supercapacitor may be limited to about 3 V to 5 V. Although not particularly limited, the maximum voltage of the supercapacitor used here is about 2.5 V, and by connecting two capacitors in series, a maximum voltage of about 5 V can be obtained.

[0028] The standby power supply unit 160 is further provided with an equivalent circuit unit 162, which is controlled based on instructions from the CPU 131 so that the stored voltages of the supercapacitors are equalized.

[0029] The standby power supply unit 160 further includes a charging unit 163. The charging unit 163 controls the standby power supply 161 so that it is charged with power from the main power supply unit 101 during normal operation.

[0030] The standby power supply unit 160 further includes a booster unit 164. The voltage of the standby power supply 161 is boosted by the booster unit 164 and supplied to the pre-driver 151 and the voltage regulator 122 via a power supply line 107 (boosted power supply line).

[0031] On the other hand, the power of the standby power supply 161 is also supplied to the driver 152 via the power supply line 105 (non-boosted power supply line), the switching element 123, and the power supply line 106 (non-boosted power supply line) without going through the boost unit 164. The opening and closing of the switching element 123 is controlled by the CPU 131 of the control unit 130, and the configuration thereof can be the same as that of the switching unit 121.

[0032] According to this embodiment, by providing the boost unit 164, it is possible to supply the necessary voltage even when the space for installing the standby power supply 161 is limited and the number of supercapacitors to be installed is limited. Furthermore, even if the power of the standby power supply is consumed by driving the motor, a boosted voltage can be supplied to the control unit, allowing the control unit to operate stably.

[0033] Furthermore, the boost power supply line that supplies the boost voltage from the boost unit 164 is supplied to the voltage regulator 122 and the pre-driver 151 for driving the CPU 131, but supplies power to the driver 150 without going through the boost circuit, so that it is possible to provide a door latch device that can supply power with high output and high efficiency while minimizing power loss in the boost circuit.

[0034] Furthermore, by providing a switching element 123 between the power supply line 105 and the power supply line 106, which are non-boosted power supply lines, the power consumption of the standby power supply 161 can be reduced by turning off the switching element 123 during normal operation.

[0035] Next, a series of operations to be performed when a vehicle malfunctions in this embodiment will be described.

[0036] The CPU 131 of the control unit 130 monitors whether or not power is being supplied normally from the main power supply unit 101, for example, by monitoring the voltage supplied from the main power supply unit 101 or the output voltage of the voltage regulator 122. The control unit 130 can be configured to detect a state in which the voltage of the main power supply has dropped to a certain level as a vehicle malfunction, not just when power from the main power supply is completely cut off.

[0037] When the control unit 130 detects that the power from the main power supply unit 101 has been cut off, the control unit 130 controls the switching unit 121 to the off state. Note that in the figure, signal lines through which control signals and detection signals are sent are schematically shown by dashed lines.

[0038] In this vehicle failure state, power is supplied from the standby power supply unit 160, and when the operating handle is operated, the sensor unit 140, which is connected to the standby power supply 161 and is supplied with power, detects the operation and sends an operation detection signal to the CPU 131 and the boost unit 164, respectively, indicating that the operation has been detected.

[0039] Upon receiving the operation detection signal, the boost unit 164 boosts the voltage of the standby power supply 161 and supplies it to the boost power supply line 107. This boost operation can be started based on a control signal from the CPU 131, but here, the operation detection signal from the sensor unit 140 is also supplied to the boost unit 164, and the boost operation is started directly by this signal. This makes it possible to quickly stabilize the boosted voltage and quickly stabilize the startup of the control unit 130. Furthermore, with this configuration, the boost operation can be started even when the control unit is not started, such as in a vehicle emergency situation, which will be described later. For this reason, the boost unit 164 may further include a boost control unit (not shown) that receives the operation detection signal from the sensor unit 140 and performs boost control.

[0040] Next, the CPU 131 of the control unit 130 controls the switching unit 123 to the ON state, and supplies power from the standby power supply 161 to the driver 152. After that, the CPU 131 drives the motor 153 via the pre-driver 151. This causes the door latch to be locked or unlocked.

[0041] In this way, in this embodiment, by providing a boosted power supply line that supplies a boosted voltage from the standby power supply and a non-boosted power supply line that supplies the voltage from the standby power supply without boosting it, it is possible to provide the power required for each part with high efficiency.

[0042] According to an embodiment of the present invention, the vehicle 100 may further include a collision sensor or an acceleration sensor. In Fig. 1, an example is shown in which the collision sensor 170 is provided in the vehicle door 110. However, the collision sensor 170 is not limited to this, and may also be provided in other parts of the vehicle 100.

[0043] In this embodiment, the system switches to using the standby power supply unit when a failure in the main power supply is detected, but this is not limited to this. It is also possible to switch to using the standby power supply unit when the control unit receives a vehicle emergency state signal from the collision sensor 170, or when a combination of the vehicle emergency state signal and the state of the main power supply unit is used.

[0044] Furthermore, the CPU 131, upon receiving the vehicle emergency state signal from the collision sensor 170, can be configured to disable the steering wheel operation detection signal from the sensor unit 140 or output a lock maintenance signal while the vehicle emergency state signal is being issued or for a predetermined time after receiving the vehicle emergency state signal. This makes it possible to disable unlocking of the vehicle doors for a certain period of time in the event of a vehicle collision, etc., and prevents the doors from opening even if the operating handle is touched by mistake, thereby ensuring the safety of occupants, etc.

[0045] Figures 2 and 3 show more specific aspects, particularly the operating portion, of the door latch device shown in Figure 1. In each figure, explanations of parts that are the same as those in Figure 1 will be omitted.

[0046] 2 includes a motor 253 and an H-bridge circuit that is a driver for driving the motor 253. The H-bridge circuit is made up of transistors 254, 255, 256, and 257, which are n-type FETs.

[0047] The actuation unit 250 also has a pre-driver 251, which receives a control signal from the CPU 131 of the control unit 130 and drives the motor 253 by controlling the on / off of each transistor in the H-bridge circuit.

[0048] Here, in the event of a vehicle failure, the pre-driver 251 is configured to receive a voltage boosted by the boost unit 164 via a boost power supply line. On the other hand, in the event of a vehicle failure, the H-bridge circuit serving as a driver is configured to receive a non-boosted voltage via a non-boosted power supply line.

[0049] In this way, by supplying a boosted voltage to the pre-driver 251 and a non-boosted voltage to the driver, it becomes possible to apply to the gate electrodes of the n-type FETs that make up the H-bridge circuit a voltage (for example, 10 V, which is a boosted voltage) that is sufficiently higher than the voltage (for example, 5 V, which is a non-boosted power) applied to their source-drain electrodes, making it possible to drive the motor 253 normally. Also, because the pre-driver circuit that controls the drive of the H-bridge circuit consumes relatively little power, even when driven with a boosted voltage, power consumption is relatively low. This keeps power loss in the boost circuit to a minimum, allowing for highly efficient use of the power from the standby power supply.

[0050] Furthermore, by providing the pre-driver 251, adjustment control such as PWM control of the motor can be performed by the pre-driver, and adjustment control such as preventing malfunction of the operating part can be easily performed.

[0051] 3 includes a motor 353 and an H-bridge circuit that is a driver for driving the motor 353. The H-bridge circuit is composed of high-side transistors 354 and 355, which are p-type FETs, and low-side transistors 356 and 357, which are n-type FETs.

[0052] In addition, the operating unit 350 has connected to it, as pre-drivers, transistor 361, which is an npn bipolar transistor having its collector electrode connected to the gate electrode of transistor 354; transistor 362, which is an npn bipolar transistor having its collector electrode connected to the gate electrode of transistor 355; transistor 363, which is a pnp bipolar transistor having its collector electrode connected to the gate electrode of transistor 356; and transistor 364, which is a pnp bipolar transistor having its collector electrode connected to the gate electrode of transistor 357.

[0053] Here, the base electrodes of the bipolar transistors of the pre-driver are connected to the CPU 131 of the control unit 130. The CPU 131 controls the on / off states of the bipolar transistors using control signals, thereby controlling the on / off states of the transistors 354, 355, 356, and 357 of the driver, and driving the motor 353.

[0054] 3, a p-type FET is used on the high side of the H-bridge circuit and an n-type FET is used on the low side, so it becomes possible to directly drive the pre-driver by the CPU 131 that uses a voltage stepped down by the voltage regulator 122. In addition, because the H-bridge circuit itself is driven by a non-boosted voltage, power loss in the boost circuit is kept low and the power of the standby power supply can be used with high efficiency.

[0055] Although more specific aspects of the actuation portion have been described above with reference to FIGS. 2 and 3, the embodiments of the present invention are not limited to these.

[0056] For example, it is possible to provide a driver IC for driving the motor that operates on a non-boosted voltage, and drive the motor by controlling the driver IC directly from the CPU without using a pre-driver.

[0057] Also, for example, the high-side transistor of the H-bridge circuit shown in FIG. 2 can be configured as a pnp bipolar transistor whose emitter electrode is connected to the boosted voltage and whose collector electrode is connected to the gate electrode of the high-side n-type FET.

[0058] As described above, according to the embodiments of the present invention, it is possible to provide a door latch device that has little power loss in the boost circuit and is capable of supplying power with high output and high efficiency.

[0059] Furthermore, conventional electric and electronic components for vehicles are configured to be compatible with lead batteries (12V system) as well as motors. In the future, when electric vehicles become more widespread and there is an increased need for backup power supplies, supercapacitors cannot be effectively utilized in circuit configurations that include boost circuits, so it is possible to make them compatible with electric and electronic components that are compatible with backup power supplies.

[0060] The standby power supply unit can also be configured with a capacitance element other than a supercapacitor, and can also be configured with a secondary battery such as a nickel-metal hydride battery.

[0061] Furthermore, in the embodiment of the present invention, one vehicle door has been representatively described, but the door latch device of this embodiment may be provided on each door of a vehicle.

[0062] Furthermore, the vehicle doors shown in the embodiments of the present invention may be any type of door that can be opened and closed, such as a normal type door that is rotatable relative to the vehicle, a sliding door, a double-door, or a gull-wing door, and vehicle doors that are provided with a backup power supply can be selected appropriately depending on the door type, location, number, etc.

[0063] Furthermore, although a door latch motor has been given as an example of each actuator unit, the actuator unit is not limited to a motor, and an actuator using a solenoid or the like can also be used.

[0064] Furthermore, each switching unit can also be configured by, for example, a relay element, a semiconductor relay, a power transistor, an FET, or the like.

[0065] As described above, the embodiments of the present invention have been described. In addition, the embodiments of the present invention also include the following forms.

[0066] (1) A vehicle door latch device having an operating unit driven by a motor, a control unit that controls the driving of the motor, a main power supply unit that supplies power to the control unit and the motor, a standby power supply unit that supplies power in place of the main power supply unit in the event of a vehicle failure, and a boost unit that boosts the voltage of the standby power supply of the standby power supply unit, wherein the vehicle door latch device has a boost power supply line that supplies power from the standby power supply to the control unit via the boost unit, and a non-boosted power supply line that supplies power from the standby power supply to the operating unit.

[0067] (2) A vehicle door latch device further comprising a sensor unit that detects operation of an operating handle provided on a vehicle door, and when the sensor unit detects operation of the operating handle, it inputs a detection signal to the control unit and the boost unit.

[0068] (3) The vehicle door latch device, wherein the booster unit further includes a boost controller that controls activation of the booster unit in response to the detection signal.

[0069] (4) A vehicle door latch device, wherein the control unit, when detecting a vehicle emergency state signal, disables input of the detection signal and / or outputs a signal to maintain the locked state.

[0070] (5) A vehicle door latch device including a drive control unit between the control unit and the actuation unit, the drive control unit adjusting control of the drive circuit in response to a signal from the control unit, and the drive control unit and the boost unit being connected by the boost power supply line. (6) A vehicle door latch device, wherein the non-boosted power supply line is provided with a switching unit controlled by the control unit. [Explanation of symbols]

[0071] 100 vehicles 101 Main power supply section 102, 103, 104, 105, 106, 107 Power lines 110 Vehicle Door 111 Door latch part 120 Power supply circuit section 121, 123 Switching elements 122 Voltage regulator section 130 control section 131 CPU 140 Sensor unit 150, 250, 350 operating part 151, 251 Pre-driver 152 Drivers 153, 253, 353 motors 154 Working Group 160 Standby power supply unit 161 Standby power supply 162 Equivalent circuit section 163 Live parts 164 Booster 170 Collision Sensor 254, 255, 256, 257 transistors 354, 355, 356, 357, 361, 362, 363, 364 transistors

Claims

1. an actuation unit driven by a motor; a control unit that controls the driving of the motor; a main power supply unit that supplies power to the control unit and the motor; a standby power supply that supplies power in place of the main power supply unit in the event of a vehicle breakdown; a boosting unit that boosts the voltage of the standby power supply; a boost power supply line connected to the control unit via the boost unit from the standby power supply; a non-boosted power supply line connecting the operating unit and the standby power supply; a drive control unit is provided between the control unit and the actuation unit to control the drive operation of the actuation unit in response to a signal from the control unit; The drive control unit and the boost unit are connected by the boost power supply line, and in the event of a vehicle malfunction, the voltage of the standby power supply is supplied via the boost unit.

2. 2. The vehicle door latch device according to claim 1, wherein the actuation unit and the standby power supply are connected by the non-boosted power supply line via a switching unit controlled by the control unit.

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