JP2013248946A - Electric brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric brake device capable of stably actuating a drive source of a lock mechanism without charging a battery again.SOLUTION: An electric brake device includes: an electric motor; a braking force application mechanism which applies braking forces to wheels by the output of the electric motor; and a lock mechanism which can change over a locking state that a braking force loosening operation of the braking force application mechanism is prevented and an unlocking state. The lock mechanism includes a lock member changeable to the locking state and the unlocking state and a linear solenoid 30 which drives the changeover of the lock member. A battery 46 mounted to a vehicle is connected to the linear solenoid 30 via a control circuit 45 that changes over the lock member and a boosting circuit 47 which boosts a voltage obtained by the battery 46 is provided in the control circuit 45.

Description

  The present invention relates to an electric brake device provided with a lock mechanism for parking, and relates to a technique capable of stably operating the lock mechanism.

  Conventionally, various electric brake devices having a parking brake lock mechanism for so-called parking have been proposed (Patent Document 1). As shown in FIG. 10, the parking brake lock mechanism includes a pawl wheel 101 provided on the outer peripheral surface of the motor rotor 100, a swing arm 103 having an engagement pawl 102 that can be engaged with and disengaged from the pawl wheel 101 at the tip, A torsion spring 104 that urges the engagement pawl 102 in a direction to disengage from the pawl wheel 101 and a solenoid 105 that moves the engagement pawl 102 in a direction to engage the pawl wheel 101 are provided.

Japanese Patent Laid-Open No. 2006-183809

  In the electric brake device of the prior art, when the power supply to the solenoid 105 is multiplexed, the applied voltage of the solenoid 105 is diversified, so that a stable voltage cannot be obtained, and the solenoid 105 may not be damaged or operated as it is. There is. Further, when the power supply falls below a voltage within an assumed range, the solenoid 105 cannot be operated unless the battery is charged again.

  An object of the present invention is to provide an electric brake device that can stably operate a drive source of a lock mechanism without recharging a battery.

  The electric brake device according to the present invention includes an electric motor, a braking force load mechanism that applies a braking force to a wheel by an output of the electric motor, a locked state that prevents a braking force slackening operation of the braking force load mechanism, and an allowable state. A lock mechanism that can be switched over between an unlocked state and an unlocked state. The lock mechanism is an electric brake device that includes a lock member that can be switched between a locked state and an unlocked state, and an actuator that switches and drives the lock member. A battery mounted on a vehicle is connected to the actuator via a control circuit that switches the lock member, and a booster circuit that boosts the voltage obtained by the battery is provided in the control circuit. To do.

  According to this configuration, when the vehicle travels, the locking mechanism is set to the unlocked state and the electric motor is driven so that the braking force load mechanism applies a braking force to the wheels. During parking, the lock member is switched to the locked state and driven by the actuator of the lock mechanism while the braking force load mechanism applies a braking force to the wheels. This prohibits the movement of the vehicle. When the control circuit switches the lock mechanism to the lock state and drives the lock mechanism, for example, if it is determined that the actuator does not operate and cannot be locked due to a voltage drop or the like of the battery, the voltage obtained by the battery is boosted by the boost circuit. Therefore, the actuator that is the drive source of the lock mechanism can be stably operated without recharging the battery.

The control circuit may include a switch circuit capable of switching between the battery and another battery mounted on the vehicle. When the control circuit determines that the actuator does not operate and cannot be locked due to a voltage drop of the battery, for example, the control circuit switches to another battery by the switch circuit. As a result, the actuator can be operated more reliably.
The control circuit may be provided with a decompression circuit that decompresses the voltage obtained by the other battery. When the voltage obtained from the other battery is too high as the voltage for operating the actuator, the voltage obtained from the other battery is decompressed by the decompression circuit. Thereby, an actuator can be operated stably.

  The control circuit may be provided with a boosting / depressurizing circuit that boosts or depressurizes the voltage obtained by the battery. When the voltage obtained from the battery is too low, the voltage is boosted. Conversely, when the voltage obtained from the battery is too high, the voltage is reduced. In either case, the actuator can be operated stably, and versatility can be improved.

A battery connected to the electric motor may be used for the power supply system of the actuator.
The vehicle may have a drive motor for each wheel, and a battery connected to the drive motor may be used for the power supply system of the actuator.
By multiplexing the power supply systems of the actuator in this way, the actuator can be operated stably and more reliably.

The vehicle has a steer-by-wire steering device that performs steering with a steering wheel that is not mechanically connected to a steered turning shaft, and a battery connected to the steer-by-wire steering device is connected to the actuator. You may use for the system of a power supply.
A spare battery mounted on the vehicle may be used for the power supply system of the actuator.

The control circuit has detection means for detecting that the voltage applied to the actuator has dropped below a set voltage when the lock mechanism is switched to a locked state and driven. When it is detected that the applied voltage has dropped below the set voltage, the voltage obtained by the battery may be boosted.
The control circuit has detection means for detecting that the actuator does not operate when the lock mechanism is switched to a locked state and driven, and the boosting circuit detects that the actuator is not operated by the detection means. The voltage obtained by the battery may be boosted.

A booster circuit, a decompression circuit, or a booster / decompression circuit may be integrated with the actuator of the lock mechanism.
It is good also as a motor vehicle provided with one of the said electric brake devices.

  The electric brake device according to the present invention includes an electric motor, a braking force load mechanism that applies a braking force to a wheel by an output of the electric motor, a locked state that prevents a braking force slackening operation of the braking force load mechanism, and an allowable state. A lock mechanism that can be switched over between an unlocked state and an unlocked state. The lock mechanism is an electric brake device that includes a lock member that can be switched between a locked state and an unlocked state, and an actuator that switches and drives the lock member. A battery mounted on a vehicle is connected to the actuator via a control circuit that switches the lock member, and a booster circuit that boosts the voltage obtained by the battery is provided in the control circuit. For this reason, the drive source of the lock mechanism can be stably operated without recharging the battery.

It is sectional drawing of the electric brake device which concerns on 1st Embodiment of this invention. It is an expanded sectional view of the deceleration mechanism of the same electric brake device. It is an expanded sectional view of the lock mechanism of the electric brake device. (A) is a diagram schematically showing a lock mechanism in a locked state, and (B) is a diagram schematically showing a lock mechanism in an unlocked state. It is a control circuit which controls the actuator of the lock mechanism. It is a block diagram of a control system of the electric brake device. It is a control circuit of the electric brake device which concerns on other embodiment of this invention. It is a block diagram of the electric brake device which concerns on other embodiment of this invention. It is a block diagram of the electric brake device which concerns on other embodiment of this invention. It is a schematic diagram which shows schematically the operating state of the parking brake lock mechanism of a prior art example.

  A first embodiment of the present invention will be described with reference to FIGS. The electric brake device according to this embodiment serves as both a service brake used when the vehicle is driven and a parking brake used when the vehicle is stopped. The electric brake device can be used as a service brake by setting a lock mechanism described later to an unlocked state, and the electric brake device can be used as a parking brake by setting the lock mechanism to a locked state.

  As shown in FIG. 1, the electric brake device includes a housing 1, an electric motor 2, a speed reduction mechanism 3 that decelerates the rotation of the electric motor 2, a braking force load mechanism 4, and a lock mechanism 5. A base plate 8 extending radially outward is provided at the open end of the housing 1, and the electric motor 2 is supported on the base plate 8. In the housing 1, a braking force load mechanism 4 that loads a braking force to the wheels, in this example, the brake disk 9, is incorporated by the output of the electric motor 2. The opening end of the housing 1 and the outer surface of the base plate 8 are covered with a cover 10.

The braking force load mechanism 4 will be described.
The braking force load mechanism 4 is a so-called linear motion mechanism that loads the braking force on the wheels by converting the rotational motion output from the speed reduction mechanism 3 into a linear motion. The braking force load mechanism 4 includes a slide member 11, a bearing member 12, an annular thrust plate 13, a thrust bearing 14, rolling bearings 15 and 15, a rotating shaft 16, a carrier 17, a sliding bearing 18, 19. A cylindrical slide member 11 is supported on the inner peripheral surface of the housing 1 so as to be prevented from rotating and movable in the axial direction. On the inner peripheral surface of the slide member 11, a spiral protrusion 11 a that protrudes a predetermined distance radially inward and is formed in a spiral shape is provided. A plurality of planetary rollers, which will be described later, mesh with the spiral protrusion 11a.

  A bearing member 12 is provided on one end side in the axial direction of the slide member 11 in the housing 1. The bearing member 12 has a flange portion extending radially outward and a boss portion. Rolling bearings 15 and 15 are fitted into the boss portions, and a rotary shaft 16 is fitted to the inner ring inner surface of each of the bearings 15 and 15. Therefore, the rotating shaft 16 is rotatably supported by the bearing member 12 via the bearings 15 and 15.

  A carrier 17 is provided on the inner periphery of the slide member 11 so as to be rotatable about the rotary shaft 16. The carrier 17 includes disks 17a and 17b that are arranged to face each other in the axial direction. The disk 17b close to the bearing member 12 may be referred to as an inner disk 17b, and the disk 17a may be referred to as an outer disk 17a. Of the one disk 17a, a side surface facing the other disk 17b is provided with an interval adjusting member 17c protruding in the axial direction from the outer peripheral edge portion on this side surface. In order to adjust the interval between the plurality of planetary rollers 20, a plurality of the interval adjusting members 17 c are arranged at intervals in the circumferential direction. The discs 17a and 17b are integrally provided by the distance adjusting member 17c.

  The inner disk 17b is supported by a slide bearing 18 fitted between the inner shaft 17b and the inner shaft 17b so as to be rotatable and movable in the axial direction. A shaft insertion hole is formed at the center of the outer disk 17a, and a slide bearing 19 is fitted in the shaft insertion hole. The outer disk 17a is rotatably supported on the rotary shaft 16 by a slide bearing 19. A washer that receives a thrust load is fitted to the end of the rotating shaft 16, and a retaining ring for preventing the washer from coming off is provided.

  The carrier 17 is provided with a plurality of roller shafts 21 at intervals in the circumferential direction. Both end portions of each roller shaft 21 are supported across the disks 17a and 17b. That is, the discs 17a and 17b are formed with a plurality of shaft insertion holes each having a long hole, and both end portions of the roller shafts 21 are inserted into the shaft insertion holes, and the roller shafts 21 are supported so as to be movable in the radial direction. The An elastic ring 22 that urges the roller shafts 21 radially inward is stretched around the plurality of roller shafts 21.

A planetary roller 20 is rotatably supported on each roller shaft 21, and each planetary roller 20 is interposed between the outer peripheral surface of the rotary shaft 16 and the inner peripheral surface of the slide member 11. Each planetary roller 20 is pressed against the outer peripheral surface of the rotating shaft 16 by the urging force of the elastic ring 22 spanned across the plurality of roller shafts 21. As the rotating shaft 16 rotates, each planetary roller 20 that contacts the outer peripheral surface of the rotating shaft 16 rotates due to contact friction. On the outer peripheral surface of the planetary roller 20, a spiral groove that meshes with the spiral protrusion 11a of the slide member 11 is formed.
A washer and a thrust bearing (both not shown) are interposed between the inner disk 17b of the carrier 17 and one axial end of the planetary roller 20. In the housing 1, an annular thrust plate 13 and a thrust bearing 14 are provided between the inner disk 17 b and the bearing member 12.

The deceleration mechanism 3 will be described.
As shown in FIG. 2, the speed reduction mechanism 3 is a mechanism that transmits the rotation of the electric motor 2 at a reduced speed to the output gear 23 fixed to the rotation shaft 16, and includes a plurality of gear trains. In this example, the speed reduction mechanism 3 is fixed to the end of the rotary shaft 16 by sequentially reducing the rotation of the input gear 24 attached to the rotor shaft 2 a of the electric motor 2 by the gear trains 25, 26 and 27. Transmission to the output gear 23 is possible.

The lock mechanism 5 will be described.
As shown in FIG. 3, the lock mechanism 5 is configured to be switchable between a locked state where the braking force slack operation of the braking force load mechanism 4 (FIG. 2) is blocked and an allowed unlocked state. In the round frame A of FIG. 3, the locked state of the locking mechanism 5 is represented by a two-dot chain line, and the unlocked state is represented by a solid line. The deceleration mechanism 3 is provided with a lock mechanism 5. As shown in FIG. 4A, the lock mechanism 5 includes a casing 40, a lock pin 29 that is a lock member, a biasing means 41 that biases the lock pin 29 to an unlocked state, and a lock pin 29. And a linear solenoid 30 that is an actuator for switching driving. The casing 40 is supported by the base plate 8 (FIG. 3), and a pin hole that allows the lock pin 29 to advance and retreat is formed in the base plate 8.

  A linear solenoid 30 including a coil bobbin 42 and a coil 43 wound around the coil bobbin 42 is provided in the casing 40. A part of the lock pin 29 made of an iron core is slidably provided in the hole of the coil bobbin 42. In the casing 40, a flange-shaped spring receiving member 44 is fixed to the middle portion in the longitudinal direction of the lock pin 29. In the casing 40, a base end portion 40a in which a through hole allowing the lock pin 29 to advance and retract is formed. In the casing 40, an urging means 41 including a compression coil spring is interposed between the base end portion 40a and the spring receiving member 44.

The lock pin 29 can be switched between a locked state shown in FIG. 4 (A) and an unlocked state shown in FIG. 4 (B). That is, as shown in FIG. 3, the intermediate gear 28 on the output side of the gear train 26 has a plurality of locking holes 28a formed at regular intervals in the circumferential direction. A lock pin 29 is provided at one point on the pitch circle of the locking holes 28a so as to be advanced and retracted by the linear solenoid 30. When the lock pin 29 is in the unlocked state shown in FIG. 4B, when the linear solenoid 30 is energized by a control circuit described later, the linear solenoid 30 is attached by the urging means 41 as shown in FIG. The lock pin 29 is switched to the locked state and driven against the force.
The lock mechanism 29 is locked by advancing the lock pin 29 by the linear solenoid 30 to engage the locking hole 28a and prohibiting the rotation of the intermediate gear 28. When the linear solenoid 30 is turned off, the spring receiving member 44 is pushed down to the bottom side in the casing 40 by the urging force of the urging means 41. As a result, the lock pin 29 is retracted into the casing 40 to be detached from the locking hole 28a, and the rotation of the intermediate gear 28 is allowed, whereby the lock mechanism 5 can be unlocked.

FIG. 5 shows a control circuit 45 that controls the linear solenoid 30 of the lock mechanism 5.
As shown in the figure, a battery 46 mounted on the vehicle is electrically connected to the linear solenoid 30 via a control circuit 45 that switches the lock pin 29 (FIG. 3). A control circuit 45 is provided in a general control unit (FIG. 6) of the ECU which will be described later. The control circuit 45 is provided with a booster circuit 47 that boosts the voltage obtained by the battery 46. The booster circuit 47 includes a switching element 48, a control circuit unit 49, capacitors C 1 and C 2, a coil 50, and a diode 51. A battery 46, a switching element 48, a capacitor C1, and a capacitor C2 are connected in parallel to the linear solenoid 30. A coil 50 that outputs a high voltage and a diode 51 that rectifies the current output from the coil 50 are sequentially connected to the output side of the battery 46.

  The switching element 48 is a switching element 48 capable of switching connection to either one of a path (1) for flowing the current output from the battery 46 to the switching element side and a path (2) for flowing the current to the linear solenoid side. is there. In this example, an NPN transistor is used as the switching element 48, and the collector of this transistor is connected to the output side of the coil 50. A control circuit unit 49 for generating an on / off rectangular wave is connected to the base of the transistor. The control circuit unit 49 is configured to be able to control a duty representing an on-time of a pulse with respect to a switching cycle.

  When the transistor is on, the current flows through the path (1), and energy is stored in the coil 50. When the transistor is off, the current flows through the path (2), and the energy stored in the coil 50 is released. When this transistor is off, current flows through the diode 51 to the capacitor C1 and the linear solenoid 30. A voltage required for the linear solenoid 30 is input by repeatedly turning on and off the transistor based on a command from the control circuit unit 49. When the transistor is off, the charge stored in the capacitor C1 is discharged to the battery 46 in order to fill the valley of the rectangular wave. Capacitor C2 charges and discharges to stabilize the voltage of battery 46 regardless of whether the transistor is on or off.

FIG. 6 is a block diagram of a control system of this electric brake device.
As shown in the figure, the vehicle is provided with an ECU 52 that is an electric control unit for controlling the entire vehicle. The ECU 52 mainly includes a travel control unit 52a and a general control unit 52b. The travel control unit 52 a issues an acceleration / deceleration command from an acceleration command output from the sensor 38 according to the depression amount of the accelerator pedal 37 and a deceleration command output from the sensor 33 according to the operation amount of the brake pedal 32. Generate.

  The general control unit 52b has a function of controlling the brake control unit 52ba and various auxiliary machine systems (not shown). The brake control unit 52ba is means for controlling the electric brake device as a parking brake when the vehicle is stopped. The brake control unit 52ba can drive the linear solenoid 30 based on the detection signal of the sensor 33 and the operation command of the lock mechanism operation unit 34. The control circuit 45 is provided in the brake control unit 52ba. The control circuit 45 includes detection means 45a and the booster circuit 47. The detecting means 45a detects that the voltage applied to the linear solenoid 30 has dropped below the set voltage when the lock mechanism 5 (FIG. 1) is switched to the locked state and driven. When the detecting means 45a detects that the applied voltage has dropped below the set voltage, the booster circuit 47 performs a boosting operation on the voltage obtained by the battery 46.

An inverter device 39 is connected to the ECU 52, and the inverter device 39 includes a power circuit unit 39a provided for each electric motor 2 and a motor control unit 39b for controlling the power circuit unit 39a. The motor control part 39b may be provided in common with respect to each power circuit part 39a, or may be provided separately.
The motor control unit 39b includes a computer, a program executed on the computer, and an electronic circuit. The motor control unit 39b converts it into a current command according to a deceleration command given from the travel control unit 52a or the brake control unit 52ba, and gives a current command to the PWM driver of the power circuit unit 39a.

The effect will be described.
When the vehicle is traveling, the locking mechanism 5 is kept in the unlocked state and the electric motor 2 is driven so that the braking force load mechanism 4 applies a braking force to the wheels. At the time of parking, the lock pin 29 is switched to the locked state by the linear solenoid 30 while the braking force load mechanism 4 applies a braking force to the wheels. This prohibits the movement of the vehicle. When the control circuit 45 detects that the voltage applied to the linear solenoid 30 has fallen below the set voltage due to, for example, a voltage drop of the battery 46 when the lock mechanism 5 is switched to the locked state, The obtained voltage is boosted by the booster circuit 47. Therefore, the linear solenoid 30 that is the drive source of the lock mechanism 5 can be stably operated without charging the battery 46 again.

Another embodiment will be described.
In the following description, the same reference numerals are given to the portions corresponding to the matters described in the preceding forms in each embodiment, and the overlapping description is omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

Instead of the above-described booster circuit, the decompression circuit 53 shown in FIG.
For example, when the vehicle has a drive motor for each wheel and a battery 46A or the like connected to these drive motors is used for the power supply system of the linear solenoid 30, the battery voltage is too high. 53 is used to step down the voltage obtained by the battery 46A. The decompression circuit 53 differs from the boosting circuit 47 in the arrangement positions of the coil 50, the switching element 48, and the diode 51. When the transistor which is the switching element 48 is on, the current flows through the path (1), and when it is off, the current flows through the path (2). The voltage obtained by the battery 46A is stepped down by repeating ON / OFF of the transistor based on a command from the control circuit unit 49, and a necessary voltage is input to the linear solenoid 30. Thereby, the linear solenoid 30 can be operated stably. When the transistor is off, the charge stored in the capacitor C1 is discharged to the linear solenoid 30 in order to fill the valley of the rectangular wave. Capacitor C2 charges and discharges to stabilize the voltage of battery 46A regardless of whether the transistor is on or off.

  The control circuit 45 may be provided with a boosting / depressurizing circuit that boosts or depressurizes the voltage obtained by the batteries 46 and 46A. When the voltage obtained by the batteries 46 and 46A is too low, the voltage is boosted. Conversely, when the voltage obtained by the batteries 46 and 46A is too high, the voltage is reduced. In either case, the linear solenoid 30 can be stably operated, and versatility can be improved.

  As shown in FIG. 8, the control circuit 45 may include a switch circuit 54 that can switch between a battery 46 and another battery 46B mounted on the vehicle. The other battery 46B includes a spare battery. According to this configuration, when the control circuit 45 determines that the linear solenoid 30 does not operate and cannot be locked due to, for example, a voltage drop of the battery 46, the control circuit 45 switches to another battery 46B by the switch circuit 54. Thereby, the linear solenoid 30 can be operated more reliably.

As shown in FIG. 9, the vehicle has a steer-by-wire steering device 55 that performs steering with a steering wheel that is not mechanically connected to a steered turning shaft, and is connected to the steer-by-wire steering device 55. The battery 46C thus used may be used for the power supply system of the linear solenoid 30.
The linear solenoid 30 of the lock mechanism may be integrally provided with a booster circuit 47, a decompressor circuit 53, or a booster / decompressor circuit.
The detecting means 45a of the control circuit 45 may detect that the linear solenoid 30 does not operate.

2 ... Electric motor 4 ... Braking force load mechanism 5 ... Lock mechanism 29 ... Lock pin (lock member)
30 ... Linear solenoid (actuator)
45 ... control circuit 46 ... battery 47 ... booster circuit 53 ... decompression circuit 55 ... steer-by-wire steering device

Claims (8)

Switchable between an electric motor, a braking force load mechanism that applies a braking force to the wheels by the output of the electric motor, and a locked state that prevents the braking force slack operation of the braking force load mechanism and an allowed unlocked state With a lock mechanism,
The lock mechanism is an electric brake device having a lock member that can be switched between a locked state and an unlocked state, and an actuator that switches and drives the lock member,
A battery mounted on a vehicle is connected to the actuator via a control circuit that switches the lock member,
An electric brake device comprising a booster circuit for boosting a voltage obtained from the battery in the control circuit.   The electric brake device according to claim 1, wherein the control circuit includes a switch circuit capable of switching between the battery and another battery mounted on the vehicle.   The electric brake device according to claim 2, wherein the control circuit is provided with a decompression circuit for decompressing a voltage obtained by the other battery.   4. The electric brake device according to claim 1, wherein a battery connected to the electric motor is used as a power supply system of the actuator. 5.   5. The electric vehicle according to claim 1, wherein the vehicle has a drive motor for each wheel, and a battery connected to the drive motor is used for a power supply system of the actuator. Brake device.   6. The vehicle according to claim 1, wherein the vehicle includes a steer-by-wire steering device that performs steering with a steering wheel that is not mechanically connected to a steered turning shaft. An electric brake device using a battery connected to a by-wire type steering device for a power supply system of the actuator.   7. The detection means according to claim 1, wherein the control circuit detects that the voltage applied to the actuator has dropped below a set voltage when the lock mechanism is switched to a locked state and driven. And the step-up circuit performs a step-up operation of the voltage obtained by the battery when the detecting means detects that the applied voltage has dropped below a set voltage.   8. The control circuit according to claim 1, wherein the control circuit includes detection means for detecting that the actuator does not operate when the lock mechanism is switched to a locked state and driven. An electric brake device that performs a voltage boosting operation of the voltage obtained by the battery when the detecting means detects that the actuator is not operated.

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