JP2005009633A - Electric braking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric braking device capable of increasing a life and reducing a consumption power. <P>SOLUTION: During operation of a parking brake, a solenoid coil 67 generates an electromagnetic force to negate the adsorption force of a permanent magnet 66 through short-time carriage of a first given current, and through the energizing force of an extension spring 61, an engaging claw 54 is brought into contact with a cog part 57 of a rachet 50 and locked thereat. During release of a parking brake, a plunger 64 is sucked through the suction force of a solenoid coil 67 excited through short-time carriage of a second given current and an unlock state is generated. Switching of lock and unlock operation of a parking brake lock mechanism 25 can be carried out through short-time current carriage of a solenoid coil 67. Thus, control of a consumption power and suppression of the increase in temperature of a device can be effected and as a result, a device life can be increased. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric brake device that generates a braking force by the torque of a motor, and more particularly to an electric brake device to which a function as a parking brake is added.
[0002]
[Prior art]
The electric brake device includes a caliper that includes a piston, a motor, and a rotation-linear motion conversion mechanism that converts the rotation of the motor into a linear motion and transmits the linear motion to the piston, and rotates the rotor of the motor. The piston is propelled in response to this and the brake pad is pressed against the disc rotor to generate a braking force. In such an electric brake device, usually, a driver's depression force and stroke of the brake pedal are detected by a sensor, and a desired braking force is controlled by controlling the rotation (rotation angle) of the electric motor in accordance with the detected value. Like to get.
[0003]
Recently, various studies have been made to increase the utility value by adding a parking brake (PKB) function to this type of electric brake device. For example, Patent Document 1 discloses the above-described rotation-linear motion conversion mechanism. A rotating shaft is connected to the rotating member via a clutch mechanism and a ball ramp mechanism, and a rotational force is applied to the rotating shaft from the outside by lever operation, for example, and the clutch mechanism is connected via the ball ramp mechanism. There has been proposed a mechanical brake operating mechanism that operates the rotation-linear motion converting mechanism to generate a braking force.
[0004]
However, according to the mechanical brake actuation mechanism described in the above publication, when the brake pedal is depressed with the parking brake applied by an external operation, the rotation-linear motion conversion mechanism of the electric brake device is interposed via the clutch mechanism. There is a problem in that it is connected to an external operation unit and the electric brake does not work, and the usability is poor.
[0005]
Accordingly, the present inventors have set a parking brake lock that restricts the caliper from rotating in the braking release direction of the rotor when energization to the motor is interrupted, and releases the restriction in response to energization to the motor. An electric brake device provided with a mechanism has been developed and has already been clarified in Patent Document 2. According to the electric brake device of Patent Document 1, when the motor is energized while the parking brake is activated by the operation of the parking brake lock mechanism, the parking brake is automatically operated by the rotation of the rotor of the motor, and the parking brake is automatically activated. The function of the electric brake is restored.
[0006]
[Patent Document 1]
Utility Model Registration No. 2546348
[Patent Document 2]
JP 2003-42199 A
[0007]
[Problems to be solved by the invention]
However, the electric brake device of Patent Document 2 has a problem that since the engaging pawl is always in contact with the pawl wheel, the wear tends to progress and the life is likely to be shortened accordingly. In addition, the electric brake device of Patent Document 2 energizes a solenoid provided in the parking brake lock mechanism for each operation when a normal electric brake (hereinafter referred to as normal braking to distinguish from a parking brake) is operated. In this case, there is a problem that the power consumption is increased and the temperature of the solenoid is easily increased.
The present invention has been made in view of the above circumstances, and an object thereof is to provide an electric brake device capable of extending the life and reducing the power consumption.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 comprises a caliper comprising a piston, a motor, and a rotation-linear motion conversion mechanism for converting the rotation of the motor into a linear motion and transmitting the linear motion to the piston. In the electric brake device that propels the piston in response to the rotation of the disc and presses the brake pad against the disc rotor to generate a braking force, the caliper can lock and unlock the rotation of the rotor in the braking release direction. And a unidirectional self-holding solenoid that switches between locking and unlocking operations of the locking mechanism by applying currents of different polarities for a short time.
[0009]
According to a second aspect of the present invention, in the electric brake device according to the first aspect, the lock mechanism is held in one of a locked state and an unlocked state by a biasing force of a spring member provided in the lock mechanism, The other state is maintained by the attractive force of a permanent magnet provided in the one-way self-holding solenoid.
According to a third aspect of the present invention, in the electric brake device according to the first or second aspect, the coil is provided in the one-way self-holding solenoid by the short-time energization, and is in a locked state and an unlocked state. In the switching operation, the short-time energization causes the coil to generate an electromagnetic force in a direction that cancels the holding force in the state before the switching.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An electric brake device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3, the electric brake device 1 floats the caliper 4 in the axial direction of the disk rotor 2 on a carrier 3 fixed to a non-rotating portion (knuckle or the like) of the vehicle located inside the vehicle from the disk rotor 2. I support it as possible. A pair of brake pads 5 and 6 are arranged to face each other with the disc rotor 2 interposed therebetween. The brake pads 5 and 6 are supported by the carrier 3 so as to be movable in the axial direction of the disc rotor 2.
[0011]
The caliper 4 includes a claw member 9 having a claw portion 7 on the distal end side and an annular base 8 on the proximal end side, and a caliper body 10 coupled to the claw member 9. The brake pads 6 are arranged to face each other. The caliper body 10 includes an annular body 11 coupled to the annular base 8 of the claw member 9 and a motor case 12 coupled to the annular body 11. The motor case 12 includes a cylindrical motor case main body 13 connected to the annular body 11, a motor end plate 14 covering the opening of the motor case main body 13, and a hole 15 formed in the side wall of the motor case main body 13. (Hereinafter, referred to as a hole forming portion) 13a.
[0012]
In the caliper 4, a split type piston 20 that presses the brake pad 5 on the inner side of the vehicle against the disc rotor 2, a motor 21, and a ball ramp mechanism that converts the rotation of the motor 21 into a linear motion and transmits it to the piston 20. The position of the piston 20 is changed according to wear of the (rotation-linear motion conversion mechanism) 22, the differential reduction mechanism 23 that decelerates the rotation of the motor 21 and transmits it to the ball ramp mechanism 22, and the brake pads 5 and 6. A pad wear compensation mechanism 24 for compensating for pad wear and a parking brake lock mechanism (lock mechanism) 25 for establishing a parking brake are provided. The caliper 4 also includes a one-way self-holding solenoid 60 that switches between locking and unlocking the parking brake lock mechanism 25 by applying a current of a different polarity for a short time.
[0013]
The ball ramp mechanism 22 has a ring-shaped first disk 27 that is rotatably supported via a bearing 26 on the inner peripheral portion of the coupling portion of the annular base body 8 and the annular body 11 of the caliper body 10 and a space portion. A ring-shaped second disk 29 coupled to the piston cylinder part 28 of the piston 20 inserted into the space part and a ball 30 interposed between the disks 27 and 29 are provided. The second disk 29 is held so that its rotation is restricted, and the rotational force received from the first disk 27 via the ball 30 is converted into a linear motion and transmitted to the piston 20.
[0014]
The piston 20 is divided into the piston cylinder part 28 and a piston main body 31 having a diameter larger than that of the piston cylinder part 28. The piston main body 31 is composed of a piston cylinder part 28 and a ball. A force from the ramp mechanism 22 (motor 21) is received. The piston cylinder part 28 is supported by a supporting cylinder 35 described later via a piston engaging member (reference numeral omitted) so as not to be rotatable. A reaction force sensor 33 is disposed between the bottom 32 of the hollow portion formed on the piston body 31 side of the piston cylinder body 28 and the piston body 31 so as to detect the reaction force from the piston body 31. Yes. The signal line 34 of the reaction force sensor 33 passes through a pipe 36 inserted through the support cylinder 35 and is connected to a controller 40 provided on the vehicle body. The support cylinder 35 is supported on the motor case 12 via a cylinder support member 41.
[0015]
The motor 21 includes a stator 43 fitted and fixed to the motor case 12 and a hollow rotor 44 disposed in the stator 43, and the rotor 44 is rotatably supported by the motor case 12. The motor 21 operates to rotate the rotor 44 by a desired angle with a desired torque in response to a command from the controller 40. The rotation angle of the rotor 44 is determined by a position detector 42 (resolver or the like) disposed in the rotor 44. ). In the present embodiment, the motor 21 rotates the rotor 44 in the clockwise direction R in FIG. 2 in response to a braking force generation command from the controller 40. The controller 40 not only controls the motor 21 but also controls the one-way self-holding solenoid 60 and thus the parking brake lock mechanism 25 via a drive circuit 70 as will be described later.
[0016]
As shown in FIGS. 1 and 2, the parking brake lock mechanism 25 is arranged around the pawl wheel 50 connected to the rotor 44 of the motor 21, and around the pawl wheel 50, and uses a pin 51 on the caliper body 10. And a swing arm 52 having a base end portion (reference number omitted) attached thereto. The ratchet wheel 50 is integrally provided with a plurality of teeth 57 on the outer periphery thereof.
An engaging claw 54 is pivotally attached to a substantially intermediate portion in the longitudinal direction of the oscillating arm 52 via a pin 53, and a distal end portion (hereinafter referred to as an engaging claw distal end portion) 54a is a tooth. The portion 57 can be engaged. A flange (hereinafter referred to as a swing arm flange) 52a extending in a direction perpendicular to the longitudinal direction is formed at a substantially intermediate portion of the swing arm 52, and the swing arm 52 is provided on the swing arm flange 52a. A long hole (hereinafter referred to as a swing arm flange long hole) 52b extending along the longitudinal direction is formed.
[0017]
The parking brake lock mechanism 25 further includes a fixing spring 58 that constantly urges the engaging pawl 54 in the right direction in FIG. 2 and an engaging pawl 54 that is pivotally attached to the swing arm 52 and cooperates with the fixing spring 58. A protrusion 59 that is held in an upright position that can be engaged with the ratchet wheel 50, and a tension spring 61 that biases an end (reference numeral omitted) opposite to the base end of the swing arm 52 downward in FIG. I have.
Each tooth portion 57 of the ratchet wheel 50 has a generally chevron tooth shape including a tooth surface 57a and a tooth surface 57b. In the tooth portion 57, the tooth surface 57a is directed to the front side in the rotational direction L (counterclockwise direction in FIG. 2) of the rotor 44 at the time of braking release, and the tooth surface 57b is rotated in the rotational direction R (FIG. 2) of the rotor 44 at the time of braking. (Clockwise) is set to face the front. In this case, the tooth surface 57a is formed so as to be substantially along the radial direction of the rotor 44, that is, the surface including the tooth surface 57a includes the axial center of the rotor 44 (the axial center C of the pawl wheel 50). Yes.
[0018]
The one-way type self-holding solenoid 60 includes a substantially hat-shaped housing (hereinafter referred to as a solenoid housing) 62 fixed to the hole forming portion 13 a of the motor case body 13 so as to cover the hole 15, and the solenoid housing 62. A plunger support member 65 which is disposed in the opening portion (not shown) of the internal space 63 and is mounted on the solenoid housing 62 and movably passes through the plunger 64 in the axial direction (vertical direction in FIG. 2); A permanent magnet 66 disposed on the inner space 63 side and a coil (hereinafter referred to as a solenoid coil) 67 housed in the inner space 63 are provided. The permanent magnet 66 exhibits an attractive force with respect to the plunger 64, and can suppress the movement of the plunger 64 in the downward direction in FIG.
[0019]
The solenoid coil 67 is wound around the bobbin 68. The bobbin 68 is mounted on the solenoid housing 62 so as to be housed in the internal space 63. As will be described later, the solenoid coil 67 is energized with the polarity changed, thereby generating an electromagnetic force corresponding to the polarity with respect to the plunger 64 and canceling the attracting force by the permanent magnet 66, and FIG. While allowing downward movement, the plunger 64 moved downward in FIG. 2 exhibits an attracting force due to the generated electromagnetic force so that the plunger 64 can move upward in FIG. Yes.
[0020]
The plunger 64 is arranged so that the axial direction is directed to the axial center C of the ratchet wheel 50, and the tip (not shown) thereof is a swing arm via a pin 68 inserted into the swing arm flange long hole 52b. 52. As the plunger 64 moves in the vertical direction in FIG. 2, the swing arm 52 swings counterclockwise and clockwise in FIG. 2 with the pin 51 as a fulcrum in conjunction with the movement of the plunger 64. Yes.
[0021]
The solenoid coil 67 is connected to the battery 49 via the drive circuit 70. The drive circuit 70 includes two switches (hereinafter, referred to as first and second switches) 71 and 72, which are controlled by the controller 40, and two resistors (hereinafter, first and second current limiting resistors 73, 72). 74)). The first switch 71 includes first and second fixed contacts 71a and 71b, and a movable piece 71c connectable to the first and second fixed contacts 71a and 71b. Similar to the first switch 71, the second switch 72 includes first and second fixed contacts 72a and 72b and a movable piece 72c connectable to the first and second fixed contacts 72a and 72b. Have
[0022]
The first switch 71 has its first fixed contact 71 a connected to the negative electrode (not shown) of the battery 49 via the first current limiting resistor 73, and its second fixed contact 71 b connected to the positive electrode (not shown) of the battery 49. The movable piece 71 c is connected to the one end 67 a of the solenoid coil 67. The second switch 72 has its first fixed contact 72a connected to the positive electrode of the battery 49, its second fixed contact 72b connected to the negative electrode of the battery 49 via the second current limiting resistor 74, and The movable piece 72 c is connected to the other end 67 b of the solenoid coil 67.
The movable piece 71c of the first switch 71 and the movable piece 72c of the second switch 72 are controlled by the controller 40 to connect to the first fixed contacts 71a and 72a, to the second fixed contacts 71b and 72b, and to each fixed contact ( The first fixed contacts 71a and 72b and the second fixed contacts 72a and 72b) can be selectively disconnected.
[0023]
In this case, the movable pieces 71c, 72c of the first and second switches 71, 72 operate in conjunction with the control of the controller 40, and the movable piece 71c of the first switch 71 is connected to the first fixed contact 71a. The movable piece 72c of the second switch 72 is connected to the first fixed contact 72a. The connection of the movable piece 71c of the first switch 71 to the second fixed contact 71b and the connection of the movable piece 72c of the second switch 72 to the second fixed contact 72b are performed in the same manner as described above. Similarly, the disconnection of the movable piece 71c with respect to the first fixed contact 71a and the disconnection of the movable piece 72c with respect to the second fixed contact 72a are performed in conjunction with each other.
[0024]
As described above, when the movable piece 71c of the first switch 71 is connected to the first fixed contact 71a and the movable piece 72c of the second switch 72 is connected to the first fixed contact 72a, the positive electrode of the battery 49 → the second 2 switch 72 → solenoid coil 67 → first switch 71 → first current limiting resistor 73 → closed circuit (hereinafter referred to as a first closed circuit) 80 composed of the negative electrode of the battery 49 is formed. Then, a current in the left direction in FIG. 3 (a dashed-dotted arrow) flows through the solenoid coil 67, thereby generating an electromagnetic force so as to cancel the attractive force of the permanent magnet 66 against the plunger 64. The adsorption force with respect to 64 disappears (may be reduced). The swing arm 52 swings clockwise in FIG. 2 with the pin 51 as a fulcrum by the tension spring 61 as the attracting force to the plunger 64 by the permanent magnet 66 disappears (or decreases).
[0025]
On the other hand, when the movable piece 71c of the first switch 71 is connected to the second fixed contact 71b and the movable piece 72c of the second switch 72 is connected to the second fixed contact 72b, the positive electrode of the battery 49 → the first switch 71 → A closed circuit (hereinafter referred to as a second closed circuit) 81 formed of the solenoid coil 67 → the second switch 72 → the second current limiting resistor 74 → the negative electrode of the battery 49 is formed. Then, a current in the right direction in FIG. 3 (a current having a polarity opposite to that of the current flowing through the first closed circuit 80 (a dashed-dotted arrow)) flows through the solenoid coil 67. Generates an electromagnetic force that attracts the plunger 64, and allows the plunger 64 to move upward in FIG.
[0026]
In the present embodiment, a first predetermined current, which will be described later, is applied to the solenoid coil 67 so as to generate an electromagnetic force in a direction that cancels the attractive force of the permanent magnet 66 (the unlocked state holding force with respect to the parking brake lock mechanism 25). The unlocked state is released by energizing the first predetermined current for a short time, and the parking brake lock mechanism 25 is then locked by the urging force of the tension spring 61. ing.
The second predetermined current described later generates an electromagnetic force in a direction that counteracts the pulling force of the tension spring 61, and thus an electromagnetic force in a direction that cancels the holding force on the plunger 64 (the locked state holding force on the parking brake lock mechanism 25). The electromagnetic force alone or combined with the attractive force of the permanent magnet 66 is set to a value larger than the tensile force of the tension spring 61.
Further, the urging force of the tension spring 61 is set to a value smaller than the combined force of the attraction force when the second predetermined current is applied to the solenoid coil 67 for a short time and the attracting force of the permanent magnet 66.
In the electric brake device 1, in the initial state, the solenoid coil 67 is not energized [the movable piece 71c is not connected to the first fixed contacts 71a and 72a, and the movable piece 72c is not connected to the second fixed contact 72a. , 72b are not connected. The plunger 64 is attracted by the permanent magnet 66, and in this state, the engaging pawl 54 is positioned in a state of being slightly separated from the tooth portion 57 of the pawl wheel 50.
[0027]
The operation of the electric brake device 1 configured as described above is as follows: (1a) During normal braking operation, (1b) During normal braking release, (2a) During parking brake operation, (2b) During parking brake release, (2c) It will be described below in the case of parking brake and when an abnormality occurs.
(1a) During normal braking
During normal braking in which the electric brake is activated, the rotor 44 of the motor 21 is rotated clockwise R in FIG. 2 by the driver's brake operation, and the piston 20 is propelled (advanced) to generate a braking force according to the torque of the motor 21. To do.
During this normal braking, the solenoid coil 67 is not energized, and the engaging pawl 54 is slightly separated from the tooth portion 57 of the pawl wheel 50 because the plunger 64 is attracted by the attracting force of the permanent magnet 66. Is positioned. For this reason, the rotor 44 smoothly rotates in the clockwise direction R and performs a normal braking function well.
In this case, since the rotor 44 rotates with the engagement pawl 54 detached from the tooth portion 57 of the pawl wheel 50, the generation of noise is prevented, the progress of wear is suppressed, and the efficiency of the motor 21 is improved. To do.
[0028]
(1b) When normal braking is released
When the electric brake is released, that is, when the normal braking is released, the rotor 44 of the motor 21 rotates in the counterclockwise direction L in FIG. 2 according to the driver's releasing operation, and the piston 20 moves backward to release the braking. At this time, the non-energized state with respect to the solenoid coil 67 is maintained, and the plunger 64 is attracted by the attracting force of the permanent magnet 66, so that the engagement pawl 54 remains detached from the tooth portion 57 of the pawl wheel 50. Then, the pawl wheel 50 smoothly rotates in the counterclockwise direction L in FIG. 2 integrally with the rotor 44 without coming into contact with the engaging pawl 54, thereby ensuring the release of the normal braking.
[0029]
(2a) When parking brake is activated
When the parking brake is operated, the rotor 44 of the motor 21 is rotated in the clockwise direction R in FIG. 2 by the driver's parking brake operation, and the piston 20 is propelled to generate a braking force as in the normal braking. After this braking force is generated, the connection of the movable piece 71c of the first switch 71 to the first fixed contact 71a (as a result, the first fixed contact of the movable piece 72c of the second switch 72) substantially simultaneously with the braking force becoming a predetermined value. 72a), the first closed circuit 80 is formed, and the first predetermined current (one-dot chain line) is energized to the solenoid coil 67 for a short time, and then the energization to the motor 21 is cut off. Is done.
Then, when the solenoid coil 67 is energized for a short time with the first predetermined current, the solenoid coil 67 generates an electromagnetic force that cancels the attractive force of the permanent magnet 66. The swing arm 52 swings in the clockwise direction in FIG. 2 along with the downward movement of the plunger 64 in FIG. 2 due to the urging force of the tension spring 61, and accordingly, the engagement pawl 54 is displaced toward the hand wheel 50. Then, it comes into contact with the tooth portion 57 of the ratchet wheel 50 and is held (locked) by the urging force of the tension spring 61. In the present embodiment, the locked state of the parking brake lock mechanism 25 is maintained by the urging force of the tension spring 61.
[0030]
Further, when the energization of the motor 21 is interrupted, the rotational force in the counterclockwise direction L is exerted on the rotor 44 of the motor 21 due to the influence of the rigidity of the caliper 4 (for example, the retraction of the piston 20 by the braking reaction force). The rotation force generates a pressing force on the engagement pawl 54, and the rotation of the rotor 44 in the counterclockwise direction L is restricted. As a result, a parking brake is established.
In the present embodiment, the first predetermined current is a current value at which the solenoid coil 67 can generate an electromagnetic force equivalent to canceling the magnetic force of the permanent magnet 66. In the present embodiment, the first current limiting resistor 73 is provided so that the first predetermined current secures the current value. The short time is a time (100 msec to 1 sec) from the start of energization to the time when the solenoid coil 67 generates an electromagnetic force that cancels the attractive force of the permanent magnet 66.
[0031]
(2b) When parking brake is released
When releasing the parking brake, the motor 21 is energized by the driver's parking brake releasing operation, and the rotor 44 is slightly rotated clockwise R (braking direction), and at the same time, the second closed circuit 81 is formed. Then, a second predetermined current having a polarity opposite to the first predetermined current is supplied to the solenoid coil 67 from the drive circuit 70 for a short time. Then, the pressing force acting on the engaging pawl 54 due to the rotational force is released, and at the same time, the plunger 64 is attracted by the attracting force of the solenoid coil 67 excited by energization of the second predetermined current (on the upper side of FIG. 2). Thus, the engagement pawl 54 is disengaged from the tooth portion 57, and the energization of the second predetermined current is cut off after a lapse of a certain time (the short time). The disengaged state from the tooth portion 57 (the unlocked state of the parking brake lock mechanism 25) is held by the attractive force of the permanent magnet 66. In the present embodiment, the unlocked state of the parking brake lock mechanism 25 is maintained by the attractive force of the permanent magnet 66.
[0032]
As described above, in the present embodiment, the urging force of the tension spring 61 is smaller than the combined force of the attractive force when the second predetermined current is applied to the solenoid coil 67 for a short time and the attractive force of the permanent magnet 66. Therefore, the engaging pawl 54 is disengaged from the tooth portion 57 of the pawl wheel 50 when the solenoid coil 67 is energized for a short time as described above.
Therefore, after that, if the rotor 44 of the motor 21 is rotated in the counterclockwise direction L (braking force releasing direction) at an appropriate timing, the pawl wheel 50 does not come into contact with the engaging pawl 54 and is integrally counterclockwise with the rotor 44. It rotates smoothly in the direction L, thereby releasing the parking brake.
[0033]
(2c) During parking brake, when abnormality occurs
If the solenoid coil 67 fails for some reason during the parking brake, the motor 21 is energized by the driver's parking brake release operation, and the rotor 44 is rotated counterclockwise in FIG. Rotate to. At this time, the rotational torque of the rotor 44 is sufficiently larger than the urging force of the fixed spring 58 that erects the engaging pawl 54, so that the engaging spring 54 is extended by the tooth surface 57 a of the tooth portion 57. Rotate in the direction. That is, the rotor 44 can be rotated in the braking release direction L, and the piston 20 is retracted in accordance with this rotation, the pressing force to the disc rotor 2 is released, and the parking brake is released.
[0034]
As described above, in this embodiment, when the parking brake is operated and released, that is, at all stages (2a) to (2c), a current (second predetermined current) is supplied to the solenoid coil 67 for a short time. Since only energization is performed, heat generation of the solenoid coil 67 is suppressed. Therefore, it is possible to reduce power consumption, extend the life, and reduce the size.
[0035]
As described above, in the present embodiment, the parking brake locking mechanism 25 that can lock and unlock the rotation of the rotor 44 in the braking release direction, and the locking and unlocking operations of the parking brake locking mechanism 25 have different polarities. Since the one-way self-holding solenoid 60 is switched by energizing the current for a short time, the parking brake lock mechanism 25 is switched between locking and unlocking operation by energizing the one-way self-holding solenoid 60 for a short time. Accordingly, the power consumption and the temperature rise of the apparatus can be suppressed correspondingly, and as a result, the life of the apparatus can be extended. Also, compared to the conventional technology that required the engagement pawl to be in constant contact with the pawl vehicle in order to perform the parking brake function, the contact with the pawl wheel of the engagement pawl is no longer necessary and the durability is improved accordingly. Can be achieved.
[0036]
In the present embodiment, as described above, the locked state of the parking brake lock mechanism 25 is maintained by the urging force of the tension spring 61 (see (2a) when the parking brake is activated), and the parking brake lock is locked by the attractive force of the permanent magnet 66. Although the case where the unlocked state of the mechanism 25 is maintained [see (2b) when the parking brake is released] is taken as an example, the parking brake lock mechanism 25 is held in the locked state by the attractive force of the permanent magnet instead. The parking brake lock mechanism 25 may be held in an unlocked state by a spring member.
[0037]
【The invention's effect】
According to the invention relating to the electric brake device according to any one of claims 1 to 3, the caliper can lock and unlock the rotation of the rotor in the braking release direction, and the lock mechanism can be locked and unlocked. Since it has a one-way self-holding solenoid that switches the unlocking operation by short-time energization of currents of different polarities, the one-way self-holding solenoid can be switched for a short time by switching the locking mechanism and unlocking operation. Therefore, the power consumption and the temperature rise of the apparatus can be suppressed accordingly, and the life of the apparatus can be extended. Also, compared to the conventional technology that required the engagement pawl to be in contact with the pawl wheel at all times in order to perform the parking brake function, the contact with the pawl wheel of the engagement pawl is no longer necessary and the durability is improved accordingly. Can be achieved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall structure of an electric brake device according to an embodiment of the present invention.
2 is a schematic diagram showing the parking brake lock mechanism, the one-way self-holding solenoid, and the drive circuit of FIG. 1. FIG.
FIG. 3 is a diagram illustrating the drive circuit of FIG. 2;
[Explanation of symbols]
1 Electric brake device
4 Caliper
21 Motor
25 Parking brake lock mechanism (lock mechanism)
60 One-way self-holding solenoid
61 Tension spring (spring member)
64 Plunger
66 Permanent magnet
67 Solenoid coil (coil)

Claims (3)

A caliper provided with a piston, a motor, and a rotation-linear motion conversion mechanism that converts the rotation of the motor into a linear motion and transmits the linear motion to the piston, and the piston is moved according to the rotation of the rotor of the motor. In the electric brake device that propels and generates braking force by pressing the brake pad against the disc rotor,
A lock mechanism capable of locking and unlocking the rotation of the rotor in the brake releasing direction to the caliper, and a one-way self-holding solenoid that switches between locking and unlocking operation of the locking mechanism by short-time energization of currents of different polarities. The electric brake device characterized by having. In the lock mechanism, one of a locked state and an unlocked state is held by a biasing force of a spring member provided in the lock mechanism, and the other state is a permanent magnet provided in the one-way self-holding solenoid. 2. The electric brake device according to claim 1, wherein the electric brake device is held by an adsorption force. The short-time energization is performed on a coil provided in the one-way self-holding solenoid, and during the switching operation between the locked state and the unlocked state, the holding power in the state before the switching is obtained by the short-time energization. The electric brake device according to claim 1, wherein an electromagnetic force in a direction to cancel is generated in the coil.

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