JP2007298115A - Electric disk brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric disk brake device which brings teeth of an engaging claw and a ratchet into a gentle contact with each other during operation of a parking brake. <P>SOLUTION: Peak parts dy of current, where the value of motor current becomes larger than the immediately preceding value, are intermittently contained in a graph showing a process of continually decreasing the motor current. As compared with the case where the peak parts dy of current are not contained, a motor torque enough to overcome the influence of rigidity of a caliper is generated. Accordingly, impact caused when the teeth of the engaging claw and the ratchet make contact with each other is reduced so as to prevent hitting noise caused by the impact, thereby avoiding such a situation that a driver may feel discomfort. By intermittently providing the plurality of the current peak parts dy, the engaging claw is engaged with a tooth bottom of the ratchet with less impact. Since the engaging claw is engaged with the tooth bottom with less impact, the strength of the engaging claw and the ratchet is correspondingly reduced. As a result, the engaging claw and the ratchet are reduced in size, which results in miniaturization of the whole of the device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric disc brake device that generates a braking force by a torque of a motor, and more particularly to an electric disc brake device to which a function as a parking brake is added.

  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. (Pressing force) is obtained.

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. As an example, there is an electric brake device disclosed in Patent Document 1.
An electric brake device disclosed in Patent Document 1 includes a toothed wheel provided on a rotor of a motor, an engaging claw disposed near (around) the toothed wheel, and the engaging claw with respect to the toothed wheel. A latch solenoid (latch SOL) that moves so as to be engaged and disengaged, and a latch mechanism (lock mechanism) that mechanically holds the pressing force generated by the motor, and these components provide a parking brake function. I try to demonstrate.

When the parking brake is operated, a pressing force (pressing force of the piston against the disc rotor via the brake pad) is generated by the motor torque, and then the motor torque is released while pressing the engaging claw by driving the latch solenoid. Thus, when the engaging claw receives the caliper reaction force, the pressing force is held without energizing the motor.
JP 2005-331022 A

  By the way, in the electric brake device shown by patent document 1, in order to engage a latching claw with a nail | claw car at the time of parking brake, it carries out by making small the electric current (motor current) supplied to a motor, and by extension, a motor torque. In this case, as shown in FIG. 7, even when the motor current is gradually reduced (the portion where the line segment is inclined in the line segment showing the characteristics of the motor current in FIG. 7), the engaging claw and the pawl wheel The rotational speed (motor speed) of the ratchet wheel when the teeth come into contact with each other increases.

  That is, when the motor current is gradually reduced, the rotational force in the rotor return direction caused by the caliper reaction force overcomes the electromagnetic force of the motor coil, thereby accelerating and rotating the rotor. For this reason, as shown in the columns of pressing force, motor position (rotor rotational position), and motor speed in FIG. 7, the ratchet wheel rebounds against the locking claw (tooth shape of motor position and motor speed). Appear in the section).

  The impact at the time of contact between the teeth of the engaging claw and the ratchet wheel generates a hitting sound and gives the driver an unpleasant feeling. Moreover, in order to withstand the impact, it is necessary to increase the strength of the engaging claws and the ratchet wheel. To ensure the strength, the size of the engaging claws and the ratchet wheel is increased, and the overall size of the caliper is inhibited. It was a thing.

  The present invention has been made in view of the above circumstances, and provides an electric disc brake device capable of gently making contact between teeth of an engaging claw and a ratchet wheel when a parking brake is operated with a simple configuration. With the goal.

The invention according to claim 1 has a caliper comprising a piston, a motor, and a rotation-linear motion conversion mechanism that converts rotation of the rotor of the motor into linear motion and transmits the linear motion to the piston. A propulsion device that propels the piston in response to rotation of the rotor of the motor, presses a brake pad against the disc rotor to generate a braking force, and a tooth wheel provided on the rotor of the motor or a rotating member interlocked with the rotor; A parking brake lock mechanism comprising: an engaging claw disposed around the tooth wheel; and an electric actuator that moves the engaging claw to an engagement position and an engagement disengagement position with respect to the tooth wheel. In the electric disc brake device that performs the locking operation and the unlocking operation of the parking brake lock mechanism by the movement of the engaging claw by an actuator, the parking brake operation When performing a movement, after generating a braking force of a desired magnitude by the motor, the engaging claw is engaged with one tooth portion of the ratchet wheel by the electric actuator, and then the supply current to the motor is changed. By gradually decreasing, the engagement wheel engages with the engagement claw until the engagement claw engages a tooth bottom formed by the one tooth part and a tooth part adjacent to the one tooth part. The hand wheel is rotated so that the part moves, and the supply current gradually decreases in a process in which a part where the value of the supply current is intermittently larger than the previous value is included.
According to a second aspect of the present invention, there is provided a caliper comprising a piston, a motor, and a rotation-linear motion conversion mechanism that converts rotation of the rotor of the motor into linear motion and transmits the linear motion to the piston. A propulsion device that propels the piston in response to rotation of the rotor of the motor, presses a brake pad against the disc rotor to generate a braking force, and a tooth wheel provided on the rotor of the motor or a rotating member interlocked with the rotor; A parking brake lock mechanism comprising: an engaging claw disposed around the tooth wheel; and an electric actuator that moves the engaging claw to an engagement position and an engagement disengagement position with respect to the tooth wheel. In the electric disc brake device that performs a lock operation and a lock release operation of the parking brake lock mechanism by the movement of the engaging claw by an actuator, the parking brake When performing dynamic, after generating a braking force of a desired magnitude by the motor, the rotational speed of the ratchet wheel so as not to exceed a predetermined speed, characterized thereby decreasing the current supplied to the motor.

According to the first aspect of the present invention, the step of decreasing the supply current to the motor includes a portion where the value of the supply current is intermittently increased, and therefore does not include a portion where the value is intermittently increased. As compared with this, a motor torque that can resist the influence of caliper rigidity is generated. For this reason, the impact at the time of contact between the teeth of the engaging claw and the ratchet wheel is alleviated, the occurrence of a hitting sound due to the impact is suppressed, and it is possible to avoid a situation in which the driver is uncomfortable. .
According to the second aspect of the present invention, since the rotation speed of the ratchet wheel is suppressed to a predetermined speed, the rebound phenomenon can be prevented. For this reason, the impact at the time of contact between the teeth of the engaging claw and the ratchet wheel is alleviated, the occurrence of a hitting sound due to the impact is suppressed, and it is possible to avoid a situation in which the driver is uncomfortable. .

Hereinafter, an electric disc brake device according to an embodiment of the present invention will be described with reference to the drawings.
The electric disc brake device 70 of this embodiment shown in FIG. 1 is mounted on a vehicle (not shown).
As shown in FIG. 1, the electric disc brake device 70 includes a carrier 1 fixed to a non-rotating portion (such as a knuckle) of a vehicle located inside the vehicle from a disc rotor (rotating portion of the vehicle) D, and a disc mounted on the carrier 1. The caliper 2 is supported so as to be floatable in the axial direction of the rotor D, and a pair of brake pads (friction members) 3, 4 disposed on both sides of the disk rotor D.
The brake pads 3 and 4 are supported by the carrier 1 so as to be movable in the axial direction of the disc rotor D. The caliper 2 includes a claw body 5 having a claw portion 5a on the front end side, an annular base body 6 connected to the base end side of the claw body 5 by a bolt (not shown), and a base body 6 connected to the base body 6 by a bolt 7 together. An assembly-type caliper body 10 composed of the ring-shaped support plate 8 and the motor case 9 is provided, and the claw portion 5a of the claw body 5 is disposed close to the back surface of the brake pad 4 outside the vehicle.

In the caliper 2, as shown in FIGS. 1 and 2, a piston 11 that can contact the back of the brake pad 3 inside the vehicle, a motor 12, and the rotation of the motor 12 are converted into a linear motion. A ball ramp mechanism (rotation-linear motion conversion mechanism) 13 that transmits to the piston 11, a differential deceleration mechanism 14 that decelerates the rotation of the motor 12 and transmits it to the ball ramp mechanism 13, and the brake pads 3 and 4 according to wear. A pad wear compensation mechanism 15 that compensates for pad wear by changing the position of the piston 11 and a parking brake mechanism 16 that establishes a parking brake are disposed.
In order to distinguish from the parking brake, hereinafter, the normal electric brake operation executed by the electric disk brake device 70 is referred to as normal braking operation, and the normal electric brake is referred to as normal braking.

  The piston 11 includes a main body 20 having a large diameter and a shaft 21 having a small diameter, and the main body 20 is disposed close to the brake pad 3 on the vehicle inner side. The shaft portion 21 of the piston 11 is provided with a shaft hole 21a having a square cross section, and the piston 11 is inserted into the shaft hole 21a with the tip portion of the support rod 23 extended from the end plate 22 of the motor case 9. Thus, the support rod 23 is slidably and non-rotatably supported. A rubber cover 24 for closing the inside of the caliper main body 10 from the outside is stretched between the main body portion 20 of the piston 11 and the caliper main body 10.

  The motor 12 includes a stator 25 fitted and fixed to the motor case 9 and a hollow rotor 26 disposed in the stator 25. The rotor 26 is attached to the motor case 9 and the support plate 8 by bearings 27 and 28. It is rotatably supported. The motor 12 operates to rotate the rotor 26 by a desired angle with a desired torque in response to a command from the controller 73, and the rotation angle of the rotor 26 is determined by a rotation detector (not shown) disposed inside the rotor 26. It is to be detected. The caliper body 10 is provided with a connector 29 for routing a signal line connecting the stator 25 and the rotation detector to the controller 73.

  The ball ramp mechanism 13 includes a ring-shaped first disk (rotating member) 31 supported on the inner peripheral portion of the annular base 6 of the caliper body 10 via a cross roller bearing 30 and a shaft of the piston 11. A ring-shaped second disk (linear motion member) 32 coupled to the part 21 via a threaded part S and a ball 33 interposed between the disks 31 and 32 are provided. The second disk 32 is disposed in contact with the back surface of the main body portion 20 of the piston 11, and is normally restricted from rotating by the frictional force of the wave washer 34 interposed between the second disk 32 and the caliper main body 10. .

  The ball 33 is inserted between the three ball grooves 35 and 36 formed on the opposing surfaces of the first disk 31 and the second disk 32 in an arc shape along the circumferential direction. The ball grooves 35 and 36 are inclined in the same direction and are arranged at equal intervals in the range of the same central angle (for example, 90 °). Now, the first disk 31 is viewed from the right direction in FIG. When rotating counterclockwise, the second disk 32 receives a pressing force in the left direction in FIG. At this time, since the rotation of the second disk 32 is restricted by the wave washer 34, the second disk 32 does not rotate but moves straight (advances), and the piston 11 moves forward (promotion) in response to this, The brake pad 3 inside the vehicle is pressed against the disc rotor D.

  On the other hand, an extended cylinder portion 37 that extends greatly toward the end plate 22 side of the motor case 9 is connected to the portion (screw portion S) of the second disk 32 screwed into the shaft portion 21 of the piston 11. In this extension cylinder part 37, one end is locked to the support rod 23, and a disc spring 38 that normally biases the second disk 32 toward the first disk 31 via the extension cylinder part 37 is disposed. Has been. As a result, the ball 33 of the ball ramp mechanism 13 is strongly pressed between the two disks 31 and 32, and when the first disk 31 rotates clockwise as viewed from the right direction in FIG. The piston 11 moves backward in the right direction in the figure, and the piston 11 is separated from the brake pad 3.

As shown in FIG. 2, the differential reduction mechanism 14 includes an eccentric shaft 39 formed at the end of the rotor 26 of the motor 12 extending toward the disk rotor D, and a bearing 40 on the eccentric shaft 39. The eccentric plate 41 rotatably fitted, the Oldham mechanism 42 and the eccentric plate 41 interposed between the eccentric plate 41 and the support plate 8 of the caliper body 10, and the first of the ball ramp mechanism 13. A cycloid ball speed reducing mechanism 43 is interposed between the disc 31 and the disc 31. The eccentric plate 41 revolves without rotating according to the rotation of the eccentric shaft 39 by the operation of the Oldham mechanism 42, while the cycloid ball speed reducing mechanism 43 operates according to the revolving motion of the eccentric plate 41. The first disk 31 rotates with the rotor 26 in a direction opposite to the rotor 26 at a constant rotation ratio. In FIG. 1, O ₁ represents the rotation center of the rotor 26, O ₂ represents the rotation center of the eccentric shaft 39, and δ represents the amount of eccentricity of both.

  As shown in FIG. 2, the pad wear compensation mechanism 15 is rotatably fitted to the extension cylinder portion 37 of the second disk 32 of the ball ramp mechanism 13 and is rotated to the first disk 31 with respect to the rotation direction. A limiter 44 that is operatively connected with play, a spring holder 46 that is fitted to the extension cylinder portion 37 of the second disk 32 and is fixed to the second disk 32 by a pin 45, and the spring holder The coil spring 47 is disposed around the end 46 and has one end connected to the limiter 44 and the other end connected to the spring holder 46.

  In the pad wear compensation mechanism 15, when the brake pads 3 and 4 are worn, the limiter 44 rotates in accordance with the rotation of the first disk 31 of the ball ramp mechanism 13, and the rotation is caused by the coil spring 47, the spring holder 46, Until the piston 11 transmitted to the second disk 32 via the pin 45 and stopped by the support pin 23 presses the brake pad 3 against the disk rotor D along the support pin 23, that is, a braking force is generated. It moves forward and operates to eliminate the gap for pad wear. On the other hand, after the braking force is generated, the second disk 32 and the first disk are prevented from rotating by the large frictional resistance generated in the screw portion S between the piston 11 and the second disk 32. The rotational deviation between the coil spring 47 and the rotational deviation between the spring holder 46 and the limiter 44 is absorbed by the torsional deformation of the coil spring 47.

As shown in FIG. 3, the parking brake mechanism 16 includes a lock mechanism 50 that can lock and unlock the rotation of the rotor 26 of the motor 12 in the pressing force release direction L, and lock and unlock the lock mechanism 50. And a solenoid mechanism 51 to be operated.
The lock mechanism 50 is a swing wheel 52 that is integrally formed on the outer peripheral surface of the rotor 26, and is arranged around the pinion wheel 52, and is a rocker whose base end is pivotally attached to the caliper body 10 using a pin 53. An arm 54, an engaging claw 56 whose base end is pivotally attached to a longitudinal intermediate portion of the swing arm 54 using a pin 55, and a caliper body 10, which contacts the side surface of the swing arm 54. In cooperation with the torsion spring 58, the stopper 57 for raising the swing arm 54 in the tangential direction of the rotor 26, the torsion spring 58 that normally biases the engaging claw 56 counterclockwise in FIG. And a projection 59 for holding the engaging claw 56 in an upright posture capable of engaging with the pawl wheel 52.
The ratchet wheel 52 is formed with a plurality of substantially mountain-shaped tooth portions 60 on the outer peripheral portion continuously with a tooth bottom 74 therebetween. Each tooth portion 60 of the ratchet wheel 52 rotates in the direction of rotation of the rotor 26 when the pressing force is released (counterclockwise as viewed from the right in FIG. 1) L (hereinafter referred to as a pressing force releasing direction L as appropriate). ], And the height dimension as it goes from the top of the wall surface 60a to the direction opposite to the pressing force release direction L (hereinafter referred to as pressing force generation direction R as appropriate). Is formed by an inclined surface 60b that gradually decreases. A contact portion between the inclined surface 60 b of one tooth portion 60 and the wall surface 60 a of the tooth portion 60 in the pressing force generation direction (direction R in FIG. 3) with respect to the one tooth portion 60 is a tooth bottom 74. .
The pawl wheel 52 is formed integrally with the rotor 26, but may be fixed to the rotor 26 separately. Further, the pawl wheel 52 may be provided not on the rotor 26 but on the first disk 31 interlocked with the rotor 26.

In the solenoid mechanism 51, two coils 64 and 65 are disposed with a permanent magnet 63 interposed therebetween, and when one coil 64 is energized, the plunger 66 moves in the backward direction B (right direction in FIG. 3), The electrification causes the plunger 66 to move in the forward direction A (left direction in FIG. 4), and is held at the backward end or forward end by the attractive force of the permanent magnet 63 as it is. When the coil 64 is energized and the plunger 66 moves in the backward direction B, the swing arm 54 is tilted toward the handwheel 52, and the engaging claw 56 moves toward the handwheel 52 and engages to lock the locking mechanism 50. Can be locked. Further, when the coil 65 is energized and the plunger 66 moves in the forward direction A, the swinging arm 54 is tilted in a direction away from the pawl wheel 52, and the engaging claw 56 is separated from the pawl wheel 52, and the lock mechanism 50. Can be unlocked.
The locking operation of the locking mechanism 50 is performed by stopping energization of the coil 64 and engaging the front end of the engaging claw 56 with the wall surface 60a of the claw wheel 52 without energization. Can be done automatically.
Energization or non-energization of the coils 64 and 65 is controlled by the controller 73. The controller 73 inputs a stop instruction signal from a parking operation switch 80 (not shown), and at this time, when an ignition switch (not shown) instructs the non-operation of the main body system such as the engine, the parking brake mechanism 16 (and eventually The operation of the locking mechanism 50) is controlled.

  The parking operation switch 80 is operated by the driver when the electric disc brake device 70 functions as a parking brake (when the parking brake is requested to operate), and generates a parking instruction signal 100 to the controller 73. I am trying to output. In response to the input of the parking instruction signal 100, the controller 73 operates the lock mechanism 50 to mechanically hold the pressing force (lock) when the ignition switch instructs the non-operation of the main body system. Like to do. The controller 73 controls the motor 12 according to an operation signal for a brake pedal (not shown).

The operation of the electric disc brake device 70 according to the above-described embodiment will be described separately for (a) normal braking, (b) normal braking release, (c) parking brake operation, and (d) parking brake release. To do.
In this apparatus, the solenoid mechanism 51 is turned off in advance, and a parking brake timer (hereinafter simply referred to as a timer) is initialized to zero (step S1 in FIG. 5).
The OFF of the solenoid mechanism 51 means a state in which the plunger 66 has moved in the direction A in FIG. 4. For example, the coil 64 is obtained by deenergization and the coil 65 is energized. In addition, while the coil 64 is not energized, the solenoid mechanism 51 can be turned off even when the plunger 66 is moved in the direction A in FIG. .
Further, when the solenoid mechanism 51 is turned off, the solenoid mechanism 51 is turned on when the plunger 66 is moved in the direction B in FIG. 3. For example, the coil 64 is energized and the coil 65 is deenergized. can get.

(A) During normal braking During normal braking, the controller 73 controls the motor 12 by the driver's brake operation (depressing the brake pedal), so that the rotor 26 of the motor 12 is viewed from the right in FIG. Rotate clockwise. At this time, the coil 64 is not energized, the plunger 66 moves in the forward direction A, and the swing arm 54 swings away from the rotor 26 (claw wheel 52). 56 is positioned so as to be slightly engaged and disengaged from the wall surface 60a, whereby the pawl wheel 52 (rotor 26) rotates in the pressing force generation direction R, and the function as an electric brake is guaranteed. Therefore, when the rotor 26 rotates in the pressing force generation direction R as described above, the eccentric plate 41 attached to the eccentric shaft 39 integrated therewith via the bearing 40 does not rotate by the Oldham mechanism 42 but revolves. By the revolving motion of the eccentric plate 41, the cycloid ball speed reducing mechanism 43 is operated, and the first disk 31 of the ball ramp mechanism 13 is in the opposite direction (counterclockwise direction) to the rotor 26 with a constant rotation ratio N. ).

  On the other hand, since the rotation of the second disk 32 of the ball ramp mechanism 13 is restricted by the resistance force of the wave washer 34, the second disk 32 moves forward to the disk rotor D side according to the rotation of the first disk 31. Propels and presses the brake pad 3 inside the vehicle against the disc rotor D. Then, the caliper 2 moves with respect to the carrier 1 by the reaction force, and the claw portion 5a of the claw body 5 presses the brake pad 4 on the outer side of the vehicle against the outer surface of the disc rotor D, whereby the rotation angle of the motor 12 is increased. A braking force corresponding to the torque (current) is generated. When the brake pads 3 and 4 are worn, the pad wear compensation mechanism 15 is activated to eliminate the pad wear gap. During this braking, the solenoid mechanism 51 is in a non-energized state (unlocked operation state).

(B) When normal braking is released When the electric brake is released, that is, when normal braking is released, the controller 73 controls the motor 12 in accordance with the driver's release operation (operation to stop the depression of the brake pedal). 1 rotates counterclockwise as viewed from the right in FIG. 1, and in response to this, the second disk 32 and the piston 11 are integrally retracted by the biasing force of the disc spring 38, and the pressing force to the disk rotor D is increased. It is released and normal braking is released. At this time, the solenoid mechanism 51 is in a non-energized state, and the locking mechanism 50 of the parking brake mechanism 16 maintains the unlocking operation state, so that the rotor 26 rotates smoothly in the pressing force releasing direction L (FIG. 4). To do.

(C) When the parking brake is operated When the parking brake is operated, as described above, the solenoid mechanism 51 is turned off, and a parking brake timer (hereinafter simply referred to as a timer) is initialized to zero (step S1 in FIG. 5). ), Control is performed as follows.
That is, the controller 73 determines whether or not a parking brake request input by the driver's parking brake operation has been received in a state in which the pressing force is generated by the motor current supply (step S2). If it is determined NO in step S2, step S2 is executed again.
If YES is determined in step S2 (time t1 in FIG. 6), the current motor current value (motor current value) is taken in from a current sensor (not shown), and this current value is set as a motor current command value (step S3).

  In subsequent step S4, the motor claw command value (motor current) is reduced and the rotor 26 of the motor 12 is returned to release the pressing force of the rotor 26 in order to realize the engagement of the engaging claws 56 with the pawl wheel 52. Rotate in direction L). At this time, the motor current is controlled so that the return speed (motor speed) of the rotor 26 does not exceed a specified speed. That is, by reducing the motor current, the rotor 26 rotates in the pressing force releasing direction L. At this time, it is expected that the rigidity of the caliper 2 acts on the rotor 26 and the return speed of the rotor 26 increases. . If no measures are taken, the return speed (motor speed) of the rotor 26 will be equal to or higher than the specified speed. In order to avoid such a situation, the motor current is controlled as described above. In the present embodiment, as shown in the mountain waveform of the motor current in FIG. 6, the motor current intermittently includes a portion (hereinafter referred to as a current mountain portion dy) where the motor current is larger than the previous value.

  Subsequent to step S4, data (value) indicating the current motor position is read, and the motor speed is calculated from the data indicating the current motor position and the data indicating the motor position in the previous cycle (step S5).

Here, data indicating the motor position, the motor position, and the like will be described.
The data indicating the motor position includes a distance (may be considered as a rotation angle) from a reference position (latching engagement position p1 described later) to the motor position. The data indicating the motor position is indicated by a large value corresponding to a large separation amount, for example. For convenience, the data indicating the motor position will be described as simply the motor position as appropriate. In the column of the motor position in FIG. 6, the value is larger as it goes upward, indicating that the amount of separation from the reference position (latch engagement position P1) is large. Further, the fact that the motor position is larger than the latch engagement position P <b> 1 indicates that the tooth bottom 74 does not reach the engagement claw 56, i.e., is located in front. Correspondingly, a position larger by a predetermined amount x1 than the latch engagement position P1 is referred to as a latch engagement position front position P2 for convenience.

  Further, as will be described later, when a parking brake command is received in a state in which the motor 12 is energized and the rotor 26 is rotated in the pressing force generation direction R to generate a braking force, the motor current is reduced, whereby the motor 12 Reduce the pressing force (motor torque; simply referred to as pressing force). At this time, a rotational force in the pressing force releasing direction L (referred to as a caliper 2 rigidity equal rotational force for convenience) acts on the rotor 26 due to the influence of the rigidity of the caliper 2 (for example, retreat of the piston 20 by a braking reaction force). To do.

And a motor position becomes small corresponding to the resultant force of the said motor torque (pressing force) and caliper 2 rigidity rotational force. In the process of decreasing the motor position, the solenoid mechanism 51 is turned on, and the engaging claw 56 is engaged with a part of the tooth portion 60 (the inclined surface 60b) of the claw wheel 52. Even after the engagement of the engaging claw 56 and the inclined surface 60b, the motor current is continuously reduced to further reduce the motor position. Finally, the engaging claw 56 engages with the tooth bottom 74. The motor position becomes the position where it does not become any smaller, that is, the reference position. This reference position is referred to as a latch engagement position as described above. When the engaging claw 56 is engaged with the tooth bottom 74, the motor position is not further reduced as described above, and the parking brake operation is substantially completed.
In addition, although it has been described that “the motor current is continuously reduced”, in the present embodiment, in the continuous reduction process of the motor current (the process of “motor current is continuously reduced”), FIG. As shown, the current peak portion dy (a portion where the current value becomes larger than that immediately before) is intermittently included. Thus, including the current peak portion dy is performed by the processing of steps S6 to S10 in FIG. 5 described later.

Here, the description returns to the interrupted “parking brake operation”.
Following step S5, it is determined whether or not the motor speed is equal to or lower than the first threshold value v1 (step S6).
If YES is determined in the step S6, the current command value is decreased by α so that the return speed of the motor 12 is increased (step S7). If NO is determined in step S6, it is determined whether or not the motor speed is equal to or higher than the second threshold value v2 (step S8).
If NO is determined in step S8, the current command value is held so as to hold the return speed of the motor 12 (step S9). If YES is determined in step S8, the current command value is increased by β so that the return speed of the motor 12 is decreased (step S10).

Steps S6 to S10 prevent the rotational speed of the rotor 26 and the pawl wheel 52 from exceeding a predetermined value v3. These steps are performed in the process of step S12 described later (relation to the ON operation of the solenoid mechanism 51). The engagement of the claw 56 with the tooth portion 60] is executed in the subsequent control cycle, so that the current chevron dy is intermittently included in the process of continuously reducing the motor current. As described above, in the process of continuously decreasing the motor current, the motor torque that can resist the influence of the rigidity of the caliper 2 is generated by including the current peak portion dy as compared with the case where the current peak portion dy is not included. . For this reason, the impact at the time of contact between the teeth of the engaging claw 56 and the ratchet wheel 52 (the tooth bottom 74) is alleviated, and the generation of a hitting sound due to the impact is suppressed, which in turn causes the driver to feel uncomfortable. You can avoid the situation. Furthermore, by intermittently providing a plurality of current chevron portions dy, the engagement of the engaging claws 56 with the tooth bottom 74 can be achieved with less impact.
Further, since the engagement claw 56 can be engaged with the tooth bottom 74 with less impact, the strength of the engagement claw 56 and the pawl wheel 52 can be reduced accordingly. Accordingly, it is possible to reduce the size of the caliper 2 and thus the entire apparatus by reducing the size of the engaging claw 56 and the pawl wheel 52.

Subsequent to the process in any of steps S7, S9, or S10, it is determined whether or not the motor position (hereinafter, appropriately referred to as a target motor position) Px is equal to or less than the latch engagement position front position P2 (step S11). .
If YES is determined in step S11, the coil 64 of the solenoid mechanism 51 is energized, the plunger 66 is moved in the backward direction B (right direction in FIG. 3), and the engagement claw 56 is moved in the direction of the pawl 52 (step). S12, time t2 in FIG. 6). As the engagement claw 56 moves in the direction of the tooth wheel 52, the engagement claw 56 engages with the inclined surface 60b of the one tooth portion 60. Since the solenoid mechanism 51 is energized at the position P2 before the latch engagement position by the processing of these steps S11 and S12, the energization time to the solenoid mechanism 51 can be shortened and the durability of the solenoid mechanism 51 is improved. Can be made.

  As described above, the engagement claw 56 and the inclined surface 60b of the tooth portion 60 are engaged by the process of step S12, and thereafter, the step after the return process to step S4 of step S16 described later is performed. By executing S6 to S10, as described above, in the process of continuously decreasing the motor current, by intermittently providing a plurality of current chevron portions dy, the engagement claw 56 can be engaged with the tooth bottom 74. , Can be performed with less impact.

If it is determined as NO after step S12 or in step S11, it is determined whether or not the motor speed is zero (step S13). In this determination, YES is determined not only when the motor speed is zero, but also when the motor current is zero and the motor is completely stopped.
If YES is determined in step S13 (time t3 in FIG. 6), the timer is incremented (step S14). If NO is determined in step S13, the timer is set to zero (step S15).
Subsequent to steps S14 and S15, it is determined whether or not the measurement time of the timer has reached the specified time T1 (that is, whether or not the motor speed zero state has continued for the specified time T1) (step S16).
When the engagement operation by the solenoid mechanism 51 is performed, the motor speed becomes zero. Therefore, when it is detected that the motor speed is engaged for a specified time (step S16), it is determined that the solenoid mechanism 51 has been operated, and the solenoid mechanism 51 is moved to. And the energization of the motor 12 are stopped (step S17), and the PKB operation is completed (time t4 in FIG. 6).

(D) When parking brake is released When the parking brake is released, the coil 65 is temporarily energized by the driver's parking brake release operation. As a result, the plunger 66 moves in the forward direction A, whereby the lock mechanism 50 enters the unlocking operation state, and the rotor 26 can freely rotate in the pressing force releasing direction L as shown in FIG. At this time, since energization to the motor 12 is stopped, the piston 11 is retracted by the braking reaction force, and the second disk 32 is retracted accordingly, and the rotor 26 of the motor 12 is viewed from the right direction in FIG. The motor 12 rotates counterclockwise, the rotation angle of the motor 12 returns to the original position, and the parking brake is released.

It is a schematic diagram which shows the locked state of the parking brake lock mechanism in embodiment of this invention. It is a schematic diagram which shows the lock release state of the parking brake lock mechanism in this Embodiment. It is a figure for showing the correspondence of an engaging claw and a tooth part at the time of parking brake operation. It is a figure for showing the correspondence of an engaging claw and a tooth part at the time of parking brake release. It is a flowchart which shows the action | operation of this Embodiment. It is a signal waveform diagram of the present embodiment. It is a signal waveform diagram for demonstrating the problem of a prior art.

Explanation of symbols

2 ... caliper, 3, 4 ... brake pad, 11 ... piston, 12 ... motor, 16 ... parking brake lock mechanism, 26 ... rotor of motor, 50 ... lock mechanism, 52 ... pawl wheel, 56 ... engagement claw, 51 ... Solenoid (actuator), 60 ... tooth portion, 100 ... controller, 74 ... tooth bottom, D ... disk rotor.

Claims (2)

A caliper that includes a piston, a motor, and a rotation-linear motion converting mechanism that converts the rotation of the rotor of the motor into a linear motion and transmits the linear motion to the piston; In response, the piston is propelled and the brake pad is pressed against the disk rotor to generate a braking force, and the tooth wheel provided on the rotor of the motor or a rotating member interlocked with the rotor, and disposed around the tooth wheel And a parking brake lock mechanism that moves the engagement claw to an engagement position and an engagement disengagement position with respect to the ratchet wheel, and the movement of the engagement claw by the electric actuator. In the electric disc brake device that performs the locking operation and the unlocking operation of the parking brake locking mechanism by
When performing the parking brake operation, after the braking force of a desired magnitude is generated by the motor, the engaging claw is engaged with one tooth portion of the claw wheel by the electric actuator, and then the motor is applied to the motor. By reducing the supply current, the tooth wheel with respect to the engaging claw is engaged until the engaging claw engages with a tooth bottom formed by the one tooth part and a tooth part adjacent to the one tooth part. The electric wheel is rotated so that the engagement portion moves, and the supply current diminishing process includes a portion in which the value of the supply current is intermittently larger than the immediately preceding value. Disc brake device. A caliper that includes a piston, a motor, and a rotation-linear motion converting mechanism that converts the rotation of the rotor of the motor into a linear motion and transmits the linear motion to the piston; In response, the piston is propelled and the brake pad is pressed against the disk rotor to generate a braking force, and the tooth wheel provided on the rotor of the motor or a rotating member interlocked with the rotor, and disposed around the tooth wheel And a parking brake lock mechanism that moves the engagement claw to an engagement position and an engagement disengagement position with respect to the ratchet wheel, and the movement of the engagement claw by the electric actuator. In the electric disc brake device that performs the locking operation and the unlocking operation of the parking brake locking mechanism by
When the parking brake operation is performed, after a braking force having a desired magnitude is generated by the motor, the supply current to the motor is gradually decreased so that the rotation speed of the ratchet wheel does not exceed a predetermined speed. Electric disc brake device.

Images