JP4831315B2 - Electric brake device - Google Patents

Description

  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.

  The electric brake device includes a brake body having a caliper including a piston, a motor, and a rotation-linear motion conversion mechanism that converts rotation of the motor into linear motion and transmits the linear motion to the piston. The piston is propelled in accordance with the rotation of the rotor, and the brake pad is pressed against a disc rotor attached to the wheel side to brake the wheel (generate a braking force) by this pressing 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.

Recently, various studies have been made to increase the utility value by adding a parking brake function to this type of electric brake device.
In order to use an electric disc brake that is reversible against the reaction force from the brake pad as a parking brake, it is necessary to fix the piston by some means.

For example, in an electric caliper that converts the rotational movement of a motor to a direct movement, the rotor of the motor is locked by a solenoid actuator (hereinafter referred to as a solenoid) (the pressing force is maintained). To use it as a parking brake, the solenoid must be locked in a non-energized state. (1) During normal braking, the solenoid is energized and unlocked, and during parking brake, the solenoid is de-energized. (2) Use a solenoid with a latch mechanism, and during normal braking, the solenoid is energized for a moment in the release direction and unlocked, and during parking brake, the solenoid is energized for a moment in the lock direction and locked. A mechanism (mechanism for holding the pressing force) or the like is used.
As an example of the electric brake device having the above-described parking brake function, there is an electric brake device disclosed in Patent Document 1.

  The electric brake device disclosed in Patent Literature 1 includes a caliper having a piston, a motor, and a caliper provided with a rotation-linear motion conversion mechanism that converts rotation of the motor into linear motion and transmits the linear motion to the piston. The piston is propelled according to the rotation of the rotor of the motor, the brake pad is pressed against the disk rotor to generate a braking force, and the motor rotor is provided with a plurality of substantially mountain-shaped outer peripheral portions. A toothed wheel having teeth continuously formed in the circumferential direction, an engaging claw arranged around the toothed wheel to be engaged with and disengaged from the toothed wheel, and a solenoid for moving the engaging claw And a parking brake locking mechanism (pressing force holding mechanism) that performs a parking brake operation by engaging the engaging claw with the pawl wheel.

  When the parking brake is operated, the rotor of the motor is rotated in one direction to generate a braking force, and simultaneously with the generation of the braking force, the solenoid is energized to move the engaging claw toward the pawl car side. The engagement claw is engaged with the ratchet wheel, thereby restricting the rotation of the rotor in the braking release direction and exerting a parking brake function.

  By the way, for example, when the parking brake is operated when the brake pad is at a high temperature, the brake pad contracts as the temperature decreases thereafter, and as a result, for example, as shown by curve A in FIG. There is a problem that the pressing force becomes less than the pressing force required for exhibiting the parking brake function (hereinafter referred to as necessary pressing force as appropriate). In order to solve this problem, the electric brake device can be used to generate an arbitrary pressing force, expecting a decrease in the pressing force due to a decrease in the temperature of the brake pad, and a pressing force when the parking brake is activated (hereinafter referred to as a pressing force when the parking brake is activated). May occur at a high level. However, if a pressing force is applied when the parking brake is activated at a high value, the caliper will increase in order to ensure durability.

In order to avoid this caliper increase, as shown in curve B of FIG. 10, the first parking brake operation is generated slightly higher than the required pressing force, and the parking brake is operated a predetermined number of times every specified time, Alternatively, the decrease in the pressing force is monitored using the pressing force detecting means, and every time the pressing force becomes the required pressing force, the parking brake is activated again (continuous monitoring by the pressing force detecting means, the motor drive and the parking brake lock mechanism There is one that performs solenoid driving (see Patent Document 2).
JP 2003-42199 A JP 2002-225701 A

However, in the former device (electric brake device that activates the parking brake again every specified time), it is necessary to operate the parking brake a predetermined number of times every specified time even after the engine is stopped. The power of the electric brake device cannot be stopped for a long time and power consumption increases. Conversely, if the number of times is small, the pressing force may decrease due to the temperature of the brake pad, and there is room for improvement. Was the actual situation.
Further, in the latter device (electric brake device that performs the parking brake operation every time the pressing force becomes the required pressing force), it is necessary to continuously monitor whether the pressing force becomes the required pressing force by the pressing force detecting means. For this reason, power is consumed for a long time, and there is a room for improvement as in the former apparatus.
The present invention has been made in view of the above circumstances, and an object thereof is to provide an electric brake device that can avoid wasteful power consumption.

According to the first aspect of the present invention, a brake pad driven by an electric device is pressed against a disc rotor attached to the wheel side, and a brake body that brakes the wheel by this pressing force, and a pressing force generated by the brake body are generated. A pressing force holding mechanism that performs a parking brake operation by holding, a pressing force detection means that detects a pressing force generated by the brake body, and a control device that controls the electric device and the pressing force holding mechanism. In the electric brake device, the control device includes an elapsed time measuring unit that measures an elapsed time of the parking brake operation by the pressing force holding mechanism, an elapsed time measured by the elapsed time measuring unit, and the pressing force at the elapsed time. detecting means based on the value of the pressing force detected by the brake body occurs after than the elapsed time A pressing force reduction predicting means for predicting the magnitude of the biasing force, characterized in that a parking brake actuation ends means for stopping the power supply based on the prediction result of the pressing force reduction predicting means.
According to a second aspect of the present invention, in the electric brake device according to the first aspect, the pressing force drop predicting means includes the elapsed time measured by the elapsed time measuring means and the pressing force detected by the pressing force detecting means at the elapsed time. The pressing force reduction coefficient is obtained from the force, and the magnitude of the pressing force generated by the brake body is predicted based on the pressing force reduction coefficient.

According to a third aspect of the present invention, in the electric brake device according to the second aspect, the pressing force reduction coefficient is a reduction amount of the pressing force detected by the pressing force detecting unit with respect to an elapsed time measured by the elapsed time measuring unit. It is characterized by the rate of change.
According to a fourth aspect of the present invention, in the electric brake device according to the third aspect, the parking brake operation ending unit is configured such that the pressing force decrease coefficient is less than a predetermined reference value based on a prediction result of the pressing force decrease predicting unit. When it is larger, the prediction by the pressing force decrease predicting unit is continued, and when the pressing force decrease coefficient is smaller than a predetermined reference value, the prediction by the pressing force decrease predicting unit is terminated and the power supply of the control device is stopped. and wherein the you.
According to a fifth aspect of the present invention, in the electric brake device according to the second aspect, the pressing force reduction coefficient is an elapsed time measured by the elapsed time measuring means with respect to a pressing force reduction amount detected by the pressing force detecting means. It is characterized by the rate of change.
According to a sixth aspect of the present invention, in the electric brake device according to the fifth aspect, the parking brake operation ending means is configured such that the pressing force reduction coefficient is less than a predetermined reference value based on a prediction result of the pressing force reduction prediction means. When the pressure is small, the prediction by the pressing force decrease prediction unit is continued, and when the pressing force decrease coefficient is larger than a predetermined reference value, the prediction by the pressing force decrease prediction unit is terminated and the power supply of the control device is stopped. and wherein the you.

According to a seventh aspect of the present invention, in the electric brake device according to the first aspect, the pressing force drop predicting means detects the pressing force detected by the pressing force detecting means when a predetermined time elapsed measured by the elapsed time measuring means. The magnitude of the pressing force generated by the brake body is predicted from the amount of decrease.
According to an eighth aspect of the present invention, in the electric brake device according to the seventh aspect of the invention, the parking brake operation end means is configured such that the amount of decrease in the pressing force is based on a predetermined reference value based on a prediction result of the pressing force decrease prediction means. Prediction by the pressing force drop predicting means is continued when the value is larger, and when the amount of decrease in the pressing force is smaller than a predetermined reference value, the prediction by the pressing force drop predicting means is terminated to supply power to the control device characterized in that you stop.
According to a ninth aspect of the present invention, in the electric brake device according to the first aspect, the pressing force decrease predicting unit measures the elapsed time until the pressing force decreasing amount detected by the pressing force detecting unit reaches a predetermined amount. The magnitude of the pressing force generated by the brake body is predicted from the elapsed time measured by the means.

According to a tenth aspect of the present invention, in the electric brake device according to the ninth aspect, when the parking brake operation ending means is based on a prediction result of the pressing force decrease predicting means, the elapsed time is smaller than a predetermined reference value. the continued predicted by the pressing force reduction predicting means, said elapsed time you stop the power supply termination to the control device the prediction by the pressing force reduction predicting means when greater than a predetermined reference value Features.
According to an eleventh aspect of the present invention, in the electric brake device according to the first aspect, the pressing force drop predicting means detects the pressing force detected by the pressing force detecting means when a predetermined time elapsed measured by the elapsed time measuring means. The magnitude of the pressing force generated by the brake body is predicted from the value.
According to a twelfth aspect of the present invention, in the electric brake device according to the eleventh aspect, the parking brake operation ending means is configured such that the value of the pressing force is less than a predetermined reference value based on a prediction result of the pressing force decrease prediction means. When the pressure is small, the prediction by the pressing force decrease predicting unit is continued, and when the pressing force value is larger than a predetermined reference value, the prediction by the pressing force decrease predicting unit is terminated and the power supply of the control device is stopped. and wherein the you.

According to a thirteenth aspect of the present invention, in the electric brake device according to the first aspect, the pressing force drop predicting means is the elapsed time measuring means until the pressing force value detected by the pressing force detecting means reaches a predetermined value. The magnitude of the pressing force generated by the brake body is predicted from the elapsed time measured by.
According to a fourteenth aspect of the present invention, in the electric brake device according to the thirteenth aspect, when the parking brake operation ending means is based on a prediction result of the pressing force decrease predicting means, the elapsed time is smaller than a predetermined reference value. the continued predicted by the pressing force reduction predicting means, said elapsed time you stop the power supply termination to the control device the prediction by the pressing force reduction predicting means when greater than a predetermined reference value Features.
According to a fifteenth aspect of the present invention, in the electric brake device according to any one of the first to fourteenth aspects of the present invention, the control device includes the pressing force detecting unit that requires the pressing force during the prediction of the pressing force decrease prediction unit. When the following value is detected, a re-parking brake operation control means is provided that makes the pressing force larger than the required pressing force by the electric device.
According to a sixteenth aspect of the present invention, in the electric brake device according to any one of the first to fifteenth aspects, the electric device is a motor, and the brake main body linearly rotates the piston, the motor, and the rotor of the motor. A caliper is provided that is provided with a rotation-linear motion conversion mechanism that converts it into motion and transmits it to the piston, and propels the piston according to the rotation of the rotor of the motor so as to press the brake pad against the disk rotor. The pressing force holding mechanism is provided so as to rotate together with the rotation of the rotor of the motor, and has a tooth wheel in which a plurality of substantially chevron-shaped teeth portions are continuously formed in the outer circumferential direction, and the periphery of the tooth wheel. And an actuator that moves the engagement claw so that the engagement claw can be engaged and disengaged, and an actuator that moves the engagement claw. And performing said parking brake actuation.

  As described above, after the parking brake operation is performed by the pressing force holding mechanism, the pressing force of the brake pad against the disc rotor gradually decreases due to the passage of time and the contraction of the brake pad with the temperature decrease. According to the present invention, before the pressing force becomes the pressing force required to maintain the parking brake function, the elapsed time measured by the elapsed time measuring means and the pressing force detected by the pressing force detecting means at the elapsed time are detected. Whether or not the pressing force is reduced to the required pressing force can be predicted based on the force value. Therefore, for example, the power supply to each member after operating the pressing force holding mechanism can be stopped earlier, and power consumption can be suppressed.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
4 and 5 show the overall structure of an electric brake device according to an embodiment of the present invention. In these drawings, reference numeral 1 denotes a carrier fixed to a non-rotating portion (such as a knuckle) of the vehicle located inside the vehicle from the disk rotor D, and 2 is supported by the carrier 1 so as to be floatable in the axial direction of the disk rotor D. The calipers 3 and 4 are a pair of brake pads disposed on both sides of the disc 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 distal 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. The carrier 1 and caliper 2 constitute a brake body (reference numeral omitted).

  In the present embodiment, in the caliper 2, a piston 11 that can contact the back surface of the brake pad 3 inside the vehicle, a motor 12, and the rotation of the motor 12 is converted into a linear motion and transmitted to the piston 11. The position of the piston 11 in accordance with the wear of the ball ramp mechanism (rotation-linear motion conversion mechanism) 13, the differential reduction 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. A pad wear compensation mechanism 15 that compensates for pad wear by changing the above and a parking brake lock mechanism (pressing force holding mechanism) 16 (FIGS. 1 and 2) that establishes a parking brake and will be described in detail later are provided. .

  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 is a brushless motor including a stator 25 fitted and fixed to the motor case 9 and a hollow rotor 26 disposed in the stator 25. In addition to the brushless motor, an ultrasonic motor or the like may be applied as the motor. The rotor 26 is rotatably supported by the motor case 9 and the support plate 8 by bearings 27 and 28. 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 100 shown in FIG. 16, and the rotation angle (rotational position) of the rotor 26 is disposed inside the rotor 26. 6 is detected by the rotational position detector 101 shown in FIG. The rotational position of the motor 12 and the thrust have a certain correspondence relationship, and this correspondence relationship is measured in advance and stored in the controller 100. Then, the thrust can be grasped from the detection data of the rotational position detector 101.
The caliper body 10 is provided with a connector 29 for routing a signal line for connecting the stator 25 and the rotational position detector 101 to the controller 100.

  The ball ramp mechanism 13 includes a ring-shaped first disk (rotating member) 31 and a shaft portion of the piston 11 that are rotatably supported on the inner peripheral portion of the annular base 6 of the caliper body 10 via a cross roller bearing 30. 21 includes a ring-shaped second disk (linear motion member) 32 coupled to the disk 21 via a threaded portion S, and a ball 33 interposed between the disks 31 and 32. 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, respectively. The ball grooves 35 and 36 are inclined in the same direction and are arranged at equal intervals in the range of an equal central angle (for example, 90 °). Now, the first disk 31 is moved from the right direction in FIGS. When rotating counterclockwise as seen, 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 FIGS. 32 moves backward in the right direction of the figure, and the piston 11 is separated from the brake pad 3.

As shown in FIG. 5, 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. And the eccentric plate 41 and the Oldham mechanism 42 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. 4, 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.

Here, in the cycloid ball reduction mechanism 43, if the diameter of the reference circle of the cycloid groove on the eccentric plate 41 side is d and the diameter of the reference circle of the cycloid groove on the first disk 31 side is D, the first to the rotor 26 is the first. The rotation ratio N of the disk 31 is N = (D−d) / D. In this case, the rotational speed of the rotor 26 when the first disk 31 makes one rotation is the reduction ratio α (= 1 / N). When the rotor 26 rotates by a certain angle θ, the rotation angle θ _A of the first disk 31 becomes θ / α, and when the inclination (lead) of the ball grooves 35 and 36 of the ball ramp mechanism 13 is L, the second angle The disk 32 moves forward by S = (L / 360) × (θ / α).

  As shown well in FIG. 5, 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 in the rotational 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 FIGS. 1 and 2, the parking brake lock mechanism 16 includes a lock mechanism 50 that can lock and unlock the rotation of the rotor 26 of the motor 12 in the braking release direction L, and locks the lock mechanism 50. And PKBSOL (PKB solenoid) as an actuator to be unlocked [hereinafter referred to as a solenoid as appropriate. ] 51.
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 pivoted with a base end portion 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, and abuts against a side surface of the swing arm 54. A stopper portion 57 for raising the swing arm 54 in the tangential direction of the rotor 26, a torsion spring (biasing means) 58 for constantly biasing the engaging claw 56 counterclockwise as viewed in FIG. A projection 59 is provided for holding the engaging claw 56 in an upright posture capable of engaging with the pawl wheel 52 in cooperation with the torsion spring 58. Here, each tooth portion 60 of the ratchet wheel 52 has a tooth surface 60a on the front side in the rotational direction L (counterclockwise as viewed from the right in FIGS. 4 and 5) of the rotor 26 at the time of braking release, and the rotor 26 at the time of braking. The tooth shape is set so that the inclined flank 60b faces the front side in the rotation direction (clockwise as viewed from the right in FIGS. 4 and 5).

  On the other hand, the solenoid 51 is configured as a two-way self-holding solenoid here. As shown in FIG. 3, the two-way self-holding solenoid 51 includes two coils 64 and 65 connected in series with a permanent magnet 63 sandwiched in a housing 62 in which a plunger 61 is slidably accommodated. The rod 61 is supported by the plunger 61 in series, and the plunger 61 moves in the two directions A or B by switching the energizing direction to the coils 64 and 65, and the permanent magnet 63 is left as it is. It is held at the forward end or backward end by the suction force of.

As shown in FIGS. 1 and 2, the parking brake lock mechanism 16 is provided with the self-holding solenoid 51 on the caliper body 10, and one end of a rod 66 integral with the plunger 61 is pivoted on the lock mechanism 50 side. The moving arm 54 is pivotally attached to the tip.
In the parking brake lock mechanism 16 having such a structure, when a current in one direction (unlock direction) is supplied to the solenoid 51 (coils 64 and 65), the rod 66 is integrated with the plunger 61 in the left direction (forward) in FIG. In the direction A, the swing arm 54 swings away from the rotor 26, and the tip of the engagement claw 56 is disengaged from the tooth 60 of the claw wheel 52. That is, the lock mechanism 50 is unlocked, and as a result, the rotor 26 can freely rotate in the braking release direction L and the braking direction R. In this case, since the plunger 61 is held at the forward end even when the energization is stopped, the energization to the coil 64 can be made temporary. From this state, when a current in the other direction (locking direction) is supplied to the solenoid 51 (coils 64, 65), the rod 66 integrally with the plunger 61 moves in the right direction (retracting direction) B (locking direction) in FIG. By moving, the swing arm 54 swings toward the side closer to the rotor 26, and the tip end portion of the engagement claw 56 engages with the tooth portion 60 of the claw wheel 52. That is, the locking mechanism 50 performs a locking operation, and as a result, the rotation of the rotor 26 in the braking release direction L is restricted. Also in this case, since the plunger 61 is held at the retracted end even when the energization is stopped, the energization to the coil 65 can be made temporary.

  As shown in FIG. 6, the solenoid 51 is supplied with power from a power source 102 via a driver circuit 103, and the driver circuit 103 is controlled by a controller (control device) 100 to drive the solenoid 51. . The motor 12 is supplied with power from the power source 102 via the driver circuit 103. The driver circuit 103 is controlled by the controller 100 to drive the motor 12, and has functions of a solenoid driver and a motor driver. The controller 100 adjusts the power supply to the solenoid 51 and the motor 12 via the driver circuit 103 (supply and supply stop, etc.) to control these operations.

  The controller 100 is connected to a rotational position detector 101 including a driver circuit 103 and a resolver. The controller 100 is further connected to a pedal force sensor 105, a parking brake on / off switch 106, a speaker 107, a warning light 108, and a pressing force sensor 110. The pressing force sensor 110 is disposed inside the shaft portion 21 of the piston 11 and detects the pressing force of the piston 11 and consequently the brake pad 3 against the disc rotor D. The controller 100 controls the operation of the pressing force sensor 110 by adjusting the power supply to the pressing force sensor 110 (supply and stop of supply).

The controller 100 is connected to a timer 112 (elapsed time measuring means) that measures the elapsed time of the parking brake operation, and the measured time measured by the timer 112 can be used.
When the parking brake (PKB) is actuated, the controller 100 will be described in the re-parking brake necessity determination process shown in FIG. 7 [[operation in re-parking brake necessity determination described later]. ] Is to be executed.

  Regarding the operation of the electric brake device, [when normal braking], [when normal braking is released], [when parking brake (PKB) is activated], and [when parking brake is released] This will be described below.

[Normal braking]
During normal braking in which the electric brake is activated, the rotor 26 of the motor 12 rotates clockwise as viewed from the right in FIGS. At this time, the solenoid 51 of the parking brake lock mechanism 16 moves the rod 66 integral with the plunger 61 to the forward end as shown in FIG. 2, and the lock mechanism 50 is unlocked by the self-holding function of the solenoid 51. The state is maintained. Therefore, as described above, when the rotor 26 rotates in the clockwise direction, the eccentric plate 41 attached to the eccentric shaft 39 integral with the rotor 26 via the bearing 40 revolves without rotating by the Oldham mechanism 42. The revolving motion of the eccentric plate 41 activates the cycloid ball speed reduction mechanism 43 so that the first disk 31 of the ball ramp mechanism 13 has the same rotational direction N as the rotor 26 as described above (counterclockwise). ).

  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. As described above, when the brake pads 3 and 4 are worn, the pad wear compensation mechanism 15 is activated to eliminate the pad wear gap. Thus, during this braking, the self-holding solenoid 51 is in a non-energized state, and the lock mechanism 50 maintains the unlocking operation state.

[When normal braking is released]
When the electric brake is released, that is, when normal braking is released, the rotor 26 of the motor 12 rotates counterclockwise as viewed from the right in FIGS. The second disk 32 and the piston 11 are integrally retracted by the urging force, the pressing force to the disk rotor D is released, and the electric brake is released. At this time, the self-holding solenoid 51 is in a non-energized state, and the locking mechanism 50 of the parking brake locking mechanism 16 maintains the unlocking operation state, so that the rotor 26 smoothly moves in the braking release direction L (FIG. 2). Rotate to.

[When parking brake (PKB) is activated]
When the parking brake is requested to operate, first, the motor 12 (rotor 26) is rotated in a direction (clockwise direction R) in which a braking force is generated to generate a required thrust (target thrust).
Thereafter, the motor 12 (rotor 26) is further rotated in the same direction (clockwise direction R) by a predetermined amount (for example, a length corresponding to one pitch of the tooth wheel 52, that is, one mountain of the tooth portion 60). A braking force (pressing force) larger than the braking force (necessary pressing force) is generated, a current in the lock direction is supplied to the solenoid 51 (coils 64, 65), and the plunger 61 is moved in the B direction (lock direction).

  As the plunger 61 moves in the B direction, the engaging claw 56 engages with the tooth portion 60. In this state, the current of the motor 12 is gradually reduced. Then, due to the reversibility of the caliper 2, the piston 11 (the motor 12 and thus the rotor 26) gradually returns to a direction in which the magnitude of the braking force is reduced (braking release direction L), that is, the rotor 26 (claw wheel 52) is released from braking. Rotate in direction L. When the engaging claw 56 reaches the tooth bottom (reference numeral omitted), the rotation of the rotor 26 (claw wheel 52) in the braking release direction L is stopped, and the movement of the piston 11 in the direction of weakening the braking force is stopped.

  The controller 100 detects a change in the detection value of the rotational position detector 101, and when a predetermined time elapses after the change disappears, the current of the motor 12 and the magnitude of the current flowing through the solenoid 51 (coils 64, 65). Is set to 0 (off). And even if the magnitude | size of the electric current of the motor 12 and the electric current sent through the solenoid 51 (coil 64,65) is set to 0 (off), the parking brake function is carried out because the engaging claw 56 is engaged with the tooth bottom. Demonstrated.

[When parking brake (PKB) is released]
When releasing the parking brake, a current is temporarily supplied to one coil 64 (FIG. 3) of the self-holding solenoid 51 of the parking brake lock mechanism 16 by the driver's parking brake releasing operation. Then, the rod 66 moves in the forward direction A integrally with the plunger 61 in the solenoid 51, whereby the lock mechanism 50 enters the unlocking operation state, and the rotation of the rotor 26 in the brake releasing direction L is performed as shown in FIG. Be free. At this time, since energization to the motor 12 is stopped, the piston 11 is retracted by the reaction force of braking, and the second disk 32 is retracted accordingly, and the rotor 26 of the motor 12 moves in the right direction in FIGS. , The rotation angle of the motor 12 returns to the original position and the parking brake is released.

[Operation for determining whether or not a re-parking brake is required]
The necessity determination of the reparking brake is performed in the parking brake operating state. The operation in the necessity determination of the reparking brake including the parking brake operation performed before the reparking brake and the operation after the reparking brake will be described below with reference to FIG.
In this operation, the controller 100 first turns off a re-PKB unnecessary flag (to be described later) as shown in FIG. 7 (step S0), and then rotates the motor 12 forward to increase the pressing force (step S1). The pressing force sensor 110 detects the pressing force of the brake pad 3 generated by the operation of the motor 12 against the disc rotor D (hereinafter simply referred to as pressing force as appropriate) (step S2). The timer 112 measures the elapsed time from the time when the pressing force is generated when the parking brake is activated (step S1), and the controller 100 receives the measurement time input from the timer 112.
Subsequently, it is determined whether or not the pressing force FK detected in step S2 is greater than or equal to the pressing force Fb that is slightly larger than the pressing force (necessary pressing force) Fa necessary for parking (step S3).

If it is determined in step S3 that the pressing force FK is less than the pressing force Fb (NO), the process returns to step S1, and steps S1 to S3 are repeated until the pressing force FK reaches the pressing force Fb.
If it is determined in step S3 that the pressing force FK is equal to or greater than the pressing force Fb (YES), the rotation of the motor 12 is stopped (step S4), the parking brake lock mechanism 16 is operated, and then the motor 12 is energized. Stop (step S5).

  Subsequently, the input of the pressing force FK from the pressing force sensor 110 is received to monitor the decrease in the pressing force FK (step S6), and the elapsed time obtained by the timer 112 and the pressing force sensor 110 detected at the elapsed time are detected. A pressing force reduction coefficient At (a pressing force reduction amount per unit time (a time shorter than the time from 0 to T1 in FIG. 10), that is, a rate of change of the pressing force reduction amount) is obtained from the reduction amount of the pressing force FK (step S7) Based on the pressing force reduction coefficient At, it is determined whether the parking brake operation by the parking brake lock mechanism 16 is necessary again (step S8).

Here, the pressing force reduction coefficient At will be described.
When the pressing force continuously decreases with a pressing force reduction coefficient At for a predetermined time, the subsequent pressing force reduction amount becomes a value obtained by adding the predetermined time to the pressing force reduction coefficient At, and the pressing force reduction amount The pressing force reduction coefficient At is indicated by a straight line E having a proportional relationship as shown in FIG. According to FIG. 8, if the pressing force decrease coefficient At is large, the subsequent pressing force decrease amount becomes large, and if the pressing force decrease coefficient At is small, the subsequent pressing force decrease amount becomes small.

In addition, when the temperature of the brake pads 3 and 4 decreases with the lapse of time from the time when the pressing force is generated, and the pressing force decreases, the pressing force does not decrease with a constant pressing force decrease coefficient At, but the pressing force. The decrease coefficient At gradually decreases, and finally becomes 0 as indicated by the slopes (right side portions) of the curves A and B in FIG. 10, for example (the pressing force decrease converges (saturates)).
In the determination of step S8 (determination of necessity of parking brake operation), the pressing force decrease coefficient At is larger than the pressing force decrease coefficient reference value dF1 as compared with a predetermined pressing force decrease coefficient reference value dF1 as will be described later ( At> dF1), whether the determination in step S8.2 is equivalent (At = dF1), or small (At <dF1) [For convenience, the above determinations are continued in this order in this order, and re-parking is performed once. It is referred to as determination hb, re-parking unnecessary determination hc, hd. And processing according to the determination result.

  Further, if the same (At = dF1) determination is performed once in step S8.2, it is determined whether or not the re-PKB unnecessary flag is turned on in the next step S8.1. Then, the re-parking unnecessary determination hd is performed. In the re-parking unnecessary determination hd, the process proceeds to step S11, and power supply to the solenoid 51, the motor 12, the pressing force sensor 110, the timer 112, and the controller 100 (hereinafter referred to as the control unit 120 for convenience) is stopped [power supply stop. If it is medium (for example, the power supply to the solenoid 51 and the motor 12 is stopped at this stage), the stop is continued. The same shall apply hereinafter, and the re-parking brake necessity determination process is terminated (step S12).

Here, the pressing force reduction coefficient reference value dF1 will be described.
The pressing force lowering coefficient reference value dF1 is an elapsed time-pressing force decreasing amount characteristic (a characteristic obtained here is a pressing force as shown by curves A and B in FIG. 10) using a simulation machine or simulation corresponding to an actual machine. The reduction coefficient At shows a characteristic that gradually decreases until it becomes almost zero.), And the following is based on the pressing force reduction coefficient At-pressing force reduction amount characteristic obtained from this elapsed time-pressing force reduction amount characteristic. It is determined as follows.
That is, as will be described later, when the pressing force decrease coefficient At is equal to the pressing force decrease coefficient reference value dF1 (At = dF1), one reparking brake operation (last reparking brake operation) is performed (step). When the one-time re-parking brake operation is performed in step S10 after S10), the pressing force at the time when the pressing force reduction coefficient At becomes substantially 0 indicates a value equal to or greater than the required pressing force Fa. The pressing force lowering coefficient reference value dF1 is determined.

Here, the description will be continued by returning to the necessity determination process of the re-parking brake in FIG.
In step S8, when the pressing force reduction coefficient At is larger than the pressing force reduction coefficient reference value dF1 (At> dF1), the continuation determination ha for continuing the prediction is performed, and the pressing force is considered in consideration of the large decrease in the pressing force. It is determined whether or not FK is equal to or less than the required pressing force Fa (FK ≦ Fa?) (Step S9). If it is determined in step S9 that the pressing force FK is not less than or equal to the required pressing force Fa (determined as NO), the process returns to step S6, and steps S6 to S8 are repeated.

  If it is determined in step S8.1 that the re-PKB unnecessary flag is not turned on, the process proceeds to step S8.2, and whether the pressing force decrease coefficient At is equal to the pressing force decrease coefficient reference value dF1 (At = dF1). If At = dF1, a re-parking one-time execution determination hb is performed, and a process of turning on a re-PKB unnecessary flag indicating that the re-parking one-time execution determination hb has been performed in step S8.3 is performed. Then, the parking brake lock mechanism 16 is once released as the last reparking brake (step S10), and the process returns to step S1 to perform the operations of steps S1 to S8. In the processing of steps S1 to S8 in this case, for example, as shown in FIG. 10, the amount of decrease in the pressing force FK is Fc = (Fb−Fa ′) [where Fa ′ is a slightly larger value than Fa. It is. ] (Time T2), the parking brake is operated once. Then, as described above, the process proceeds to step S11, the power supply to the control unit 120 is stopped, and the re-parking brake necessity determination process is terminated (step S12). The pressing force-elapsed time characteristic when the re-parking brake operation is performed once again at time T2 is shown as a curve C in contrast with the curves A and B.

If it is determined in step S9 that the pressing force FK is equal to or less than the required pressing force Fa (determined as YES), the process proceeds to step S10, and then returns to step S1 to perform the operations of steps S1 to S8.
In step S8.2, if the pressing force decrease coefficient At is smaller than the pressing force decrease coefficient reference value dF1 (At <dF1), a re-parking unnecessary determination hc is performed, and power supply to the control unit 120 is stopped (step S11). Then, the necessity determination process of the re-parking brake (prediction by the pressing force decrease prediction means) is ended (step S12).

  As described above, according to the present embodiment, the elapsed time measured by the timer (elapsed time measuring means) 112 and the amount of decrease in the pressing force detected by the pressing force sensor (pressing force detecting means) 110 at the elapsed time. From this, the pressing force reduction coefficient At is obtained. On the other hand, after the parking brake operation is performed by the parking brake lock mechanism 16, the pressing force FK of the brake pad 3 against the disc rotor D gradually decreases as time elapses and the brake pad 3 contracts as the temperature decreases.

  For this reason, before the pressing force FK becomes the pressing force (necessary pressing force) Fa required for maintaining the parking brake function, the pressing force FK is used using the pressing force reduction coefficient At obtained as described above. Can be predicted to become the required pressing force Fa, and the power supply to the control unit 120 can be stopped earlier by that amount. That is, the power supply is stopped earlier than in the prior art in which the re-parking brake operation is performed when the pressing force is continuously monitored and the pressing force reaches the required pressing force or substantially the required pressing force. Therefore, it is possible to reduce power consumption (avoid wasteful power consumption).

  In the present embodiment, the pressing force decrease predicting means is constituted by the processing of S6 to S8.2 of the flowchart shown in FIG. 7, the reparking brake operation control means is constituted by S8, S9 and S10, and S8. The parking brake operation end means is constituted by the processing of 1, S8.2, and S11.

  In the above embodiment, the pressing force reduction coefficient At is set as the pressing force reduction amount per unit time. However, the present invention is not limited to this. For example, the pressing force reduction coefficient is set to the previous pressing force reduction amount per unit time. It is good also as a difference with the pressing force fall amount per unit time this time. In this case, when the decrease in the pressing force is reduced, the difference is reduced. Therefore, it is determined whether the difference is smaller than the reference value, and it is predicted that the pressing force FK becomes the required pressing force Fa. May be. Furthermore, the pressing force reduction coefficient may be an elapsed time per unit reduction amount. In this case, the processing from S7 to S9 in the flowchart of FIG. 7 is replaced with S27 to S29 as shown in FIG. 11, and the elapsed time obtained by the timer 112 and the pressing force sensor 110 detected at the elapsed time are detected. A pressing force decrease coefficient Af (elapsed time per unit decrease amount (an amount smaller than the decrease amount from Fb to Fa in FIG. 10), that is, a change rate of the elapsed time) is obtained from the decrease amount of the force FK (step S27). Based on the pressing force reduction coefficient Af, it is determined whether the parking brake operation by the parking brake lock mechanism 16 is necessary again (step S28).

  In the determination of step S28 (determination of necessity of parking brake operation), the pressing force decrease coefficient Af is larger than the pressing force decrease coefficient reference value dT1 as compared with a predetermined pressing force decrease coefficient reference value dT1 as described later ( At> dT1), whether the determination in step S28.2 is equivalent (At = dT1), or small (At <dT1). It is referred to as a single parking execution determination hb, a re-parking unnecessary determination hc, hd. And processing according to the determination result. Here, like the above-described pressing force reduction coefficient reference value dF1, the pressing force reduction coefficient reference value dT1 is determined from the elapsed time-pressing force reduction amount characteristic using a simulation machine or a simulation corresponding to the actual machine.

  In step S28, when the pressing force reduction coefficient Af is smaller than the pressing force reduction coefficient reference value dT1 (Af <dT1), the continuation determination ha is performed, and the pressing force FK is required in consideration of the large decrease in the pressing force. It is determined whether or not the force Fa or less (FK ≦ Fa?) (Step S29). If it is determined in step S29 that the pressing force FK is not less than or equal to the required pressing force Fa (determined as NO), the process returns to step S6.

If it is determined in step S28.1 that the re-PKB unnecessary flag is not turned on, the process proceeds to step S28.2, where is the pressing force decrease coefficient Af equal to the pressing force decrease coefficient reference value dT1 (Af = dT1)? If Af = dT1, a re-parking once execution determination hb is performed, and a process of turning on a re-PKB unnecessary flag indicating that the re-parking once execution determination hb is performed in step S28.3 is performed. Then, the process proceeds to step S10.
If it is determined in step S29 that the pressing force FK is equal to or less than the required pressing force Fa (determined as YES), the process proceeds to step S10, and then returns to step S1 to perform the operations of steps S1 to S8.

If the re-PKB unnecessary flag is turned on in step S28.1, and if the pressing force reduction coefficient Af is larger than the pressing force reduction coefficient reference value dT1 (Af> dT1) in step S28.2, re-parking is performed. Unnecessity determination hd and hc are performed, and the process proceeds to step S11.
Thus, even when the pressing force reduction coefficient is the elapsed time per unit reduction amount, the same effects as those of the above embodiment can be obtained.

  In addition, the necessity of the re-parking brake is determined based on the pressing force reduction coefficient. However, the present invention is not limited to this, and (1) the amount of reduction in pressing force when a predetermined time elapses or (2) the amount of predetermined reduction is reached. The necessity determination may be performed based on the elapsed time until (3) the value of the pressing force when the predetermined time elapses or (4) the elapsed time until the predetermined pressing force value is reached. Hereinafter, the determination elements (1) to (4) will be described with reference to FIGS.

  In the description of the modified examples 1 to 4, only the portion will be described by replacing the processing of S7 to S9 in the flowchart of FIG.

  In the first modification, the amount of decrease in the pressing force when a predetermined time has elapsed is used as a determination factor. As shown in FIG. 12, the pressing force detected by the pressing force sensor 110 when the predetermined time has elapsed, obtained by the timer 112. A decrease amount ΔF when a predetermined time elapses is obtained from FK (step S37), and it is determined whether or not the parking brake operation by the parking brake lock mechanism 16 is necessary again based on the decrease amount ΔF (step S38).

  In the determination in step S38 (determination of necessity of parking brake operation), the decrease amount ΔF is larger than the decrease amount reference value ΔF1 (ΔF> ΔF1) as compared with a predetermined decrease amount reference value ΔF1 as will be described later. In the determination in step S38.2, it is determined whether they are equivalent (ΔF = ΔF1) or small (ΔF <ΔF1). Each determination is a continuation determination ha and a re-parking single execution determination hb in the same manner as in the above embodiment These are referred to as re-parking unnecessary determinations hc and hd. And processing according to the determination result. Here, the decrease amount reference value ΔF1 is smaller than the decrease amount from Fb to Fa in FIG. 10, and is determined from the elapsed time-pressing force decrease amount characteristic using a simulation machine or a simulation corresponding to the actual machine.

  In step S38, when the decrease amount ΔF is larger than the decrease amount reference value ΔF1 (ΔF> ΔF1), the continuation determination ha is performed, and the pressing force FK is less than the required pressing force Fa in consideration of the large decrease in the pressing force. Whether or not (FK ≦ Fa?) Is determined (step S39). If it is determined in step S39 that the pressing force FK is not less than or equal to the required pressing force Fa (determined NO), the process returns to step S6, and the pressing force sensor 110 detected by the timer 112 when the predetermined time has elapsed is detected. A new reduction amount ΔF at the elapse of a predetermined time is obtained from the pressing force FK (step S37).

If it is determined in step S38.1 that the re-PKB unnecessary flag is not on, the process proceeds to step S38.2 to determine whether or not the decrease amount ΔF is equal to the decrease amount reference value ΔF1 (ΔF = ΔF1). If ΔF = ΔF1, the re-parking once execution determination hb is performed, and after the process of turning on the re-PKB unnecessary flag indicating that the re-parking once execution determination hb has been performed in step S38.3 is performed. Proceed to step S10.

If it is determined in step S39 that the pressing force FK is equal to or less than the required pressing force Fa (determined as YES), the process proceeds to step S10.
If the re-PKB unnecessary flag is on in step S38.1, and if the decrease amount ΔF is smaller than the decrease amount reference value ΔF1 (ΔF <ΔF1) in step S38.2, the re-parking unnecessary determination hd, hc is performed, and the process proceeds to step S11.

  Next, in the second modification, the elapsed time until the pressing force reaches a predetermined reduction amount is used as a determination factor. As shown in FIG. 13, the pressing force FK detected by the pressing force sensor 110 is a predetermined reduction amount. The elapsed time t obtained by the timer 112 until ΔF1 is obtained (step S47), and whether or not the parking brake operation by the parking brake lock mechanism 16 is necessary again is determined based on the elapsed time t (step S48).

  In the determination of step S48 (determination of necessity of parking brake operation), the elapsed time t is smaller than the reference decrease time T1 (t <T1) as compared with a reference decrease reference time T1, which will be described later, or step S48. .2 is the same (t = T1) or larger (t> T1). [The above determinations are, in the same manner as in the above embodiment, the continuation determination ha, the re-parking once execution determination hb, It is referred to as parking unnecessary determination hc, hd. And processing according to the determination result. Here, the decrease reference time T1 is shorter than the time from 0 to T1 in FIG. 10, and is determined from the elapsed time-pressing force decrease amount characteristic using a simulation machine or simulation corresponding to the actual machine.

  In step S48, when the elapsed time t is smaller than the decrease reference time T1 (t <T1), the continuation determination ha is performed, and the pressing force FK is the required pressing force in consideration of the fact that it does not take time for the pressing force to decrease. It is determined whether or not it is equal to or less than Fa (FK ≦ Fa?) (Step S49). If it is determined in step S49 that the pressing force FK is not less than or equal to the required pressing force Fa (determined NO), the process returns to step S6, and the pressing force FK newly detected by the pressing force sensor 110 is reduced by a predetermined amount ΔF1. The elapsed time t obtained by the timer 112 until is reached is obtained (step S47).

  If it is determined in step S48.1 that the re-PKB unnecessary flag is not turned on, the process proceeds to step S48.2 to determine whether or not the elapsed time t is equal to the decrease reference time T1 (t = T1). When t = T1, the re-parking one-time execution determination hb is performed, and a step of turning on the re-PKB unnecessary flag indicating that the re-parking one-time execution determination hb is performed in step S48.3 is performed. Proceed to S10.

If it is determined in step S49 that the pressing force FK is less than or equal to the required pressing force Fa (determined as YES), the process proceeds to step S10.
If the re-PKB unnecessary flag is turned on in step S48.1, and if the elapsed time t is larger than the decrease reference time T1 (t> T1) in step S48.2, the re-parking unnecessary determination hc is performed. The process proceeds to step S11.

  Next, in the third modification, the value of the pressing force when a predetermined time has elapsed is used as a determination factor. As shown in FIG. 14, the pressing force sensor 110 detected by the timer 112 when the predetermined time has elapsed is detected. The pressing force FK is obtained (step S57), and it is determined whether the parking brake operation by the parking brake lock mechanism 16 is necessary again based on the pressing force FK (step S58).

  In the determination of step S58 (determination of necessity of parking brake operation), the pressing force FK is smaller than the pressing force reference value F1 as compared to a pressing force reference value F1 that is set in advance as will be described later (FK <F1), In the determination in step S58.2, it is determined whether they are equivalent (FK = F1) or large (F> F1). These are referred to as re-parking unnecessary determinations hc and hd. And processing according to the determination result. Here, the pressing force reference value F1 is a value between Fb and Fa in FIG. 10, and is determined from the elapsed time-pressing force characteristic using a simulation machine or simulation corresponding to the actual machine.

  In step S58, when the pressing force FK is smaller than the pressing force reference value F1 (FK <F1), the continuation determination ha is performed, and the pressing force FK is less than the required pressing force Fa in consideration of the large decrease in the pressing force. Whether or not (FK ≦ Fa?) Is determined (step S59). If it is determined in step S59 that the pressing force FK is not less than or equal to the required pressing force Fa (determined NO), the process returns to step S6, and the pressing force sensor 110 at the time when the predetermined time elapsed newly obtained by the timer 112 has elapsed. The detected pressing force FK is obtained (step S57).

  If it is determined in step S58.1 that the re-PKB unnecessary flag is not turned on, the process proceeds to step S58.2 to determine whether or not the pressing force FK is equal to the pressing force reference value F1 (FK = F1). When FK = F1, the re-parking once execution determination hb is performed, and after performing the process of turning on the re-PKB unnecessary flag indicating that the re-parking once execution determination hb is performed in step S58.3. Proceed to step S10.

If it is determined in step S59 that the pressing force FK is equal to or less than the required pressing force Fa (determined as YES), the process proceeds to step S10.
If the re-PKB unnecessary flag is turned on in step S58.1, and if the pressing force FK is larger than the pressing force reference value F1 (FK> F1) in step S58.2, the re-parking unnecessary determination hc is set. Go to step S11.

  In the third modification, when the pressing force FK is smaller than the pressing force reference value F1 (FK <F1) in step S58, the continuation determination ha is performed, and the process returns to step S6 via step S59. Yes. However, in this case, the state where the pressing force FK is smaller than the pressing force reference value F1 (FK <F1) continues. Therefore, after the continuation determination ha is performed, the pressing force FK is equal to or less than the required pressing force Fa in step S59. Even if it is determined that it is not (NO), the process may return to step S59 without returning to step S6 as indicated by the dotted line.

  Finally, in the fourth modification, the elapsed time until the pressing force reaches a predetermined pressing force value is used as a determination factor. As shown in FIG. 15, the pressing force FK detected by the pressing force sensor 110 is a predetermined pressing force. The elapsed time t obtained by the timer 112 before reaching the force value F1 is obtained (step S67), and it is determined whether or not the parking brake operation by the parking brake lock mechanism 16 is necessary again based on the elapsed time t (step S68). ).

  In the determination of step S68 (determination of necessity of parking brake operation), the elapsed time t is smaller than the decrease reference time T2 (t <T2) as compared with a decrease reference time T2 set in advance as described later, or step S68. .2 is the same (t = T2) or larger (t> T2) [the above determinations are made in the same manner as in the above embodiment, in the order of continuation determination ha, re-parking once execution determination hb, It is referred to as parking unnecessary determination hc, hd. And processing according to the determination result. Here, the decrease reference time T2 is shorter than the time from 0 to T1 in FIG. 10, and is determined from the elapsed time-pressing force characteristic using a simulation machine or simulation corresponding to the actual machine.

  In step S68, when the elapsed time t is smaller than the decrease reference time T2 (t <T2), the continuation determination ha is performed, and the pressing force FK is determined to be the required pressing force in consideration of the fact that the pressing force does not decrease in time. It is determined whether or not Fa or less (FK ≦ Fa?) (Step S69). If it is determined in step S69 that the pressing force FK is not less than or equal to the required pressing force Fa (determined NO), the process returns to step S69 again. In step S69, the pressing force FK is less than or equal to the required pressing force Fa. It repeats until it determines (it determines with YES), and when it determines with YES, it will progress to step S10.

  If it is determined in step S68.1 that the re-PKB unnecessary flag is not turned on, the process proceeds to step S68.2 to determine whether or not the elapsed time t is equal to the decrease reference time T2 (t = T2). If t = T2, a re-parking once execution determination hb is performed, and a step of turning on a re-PKB unnecessary flag indicating that the re-parking once execution determination hb is performed in step S68.3 is performed. Proceed to S10.

If the re-PKB unnecessary flag is on in step S68.1, and if the elapsed time t is greater than the decrease reference time T2 (t> T2) in step S68.2, the re-parking unnecessary determination hc is performed. The process proceeds to step S11.
As described above, whether or not the re-parking brake is necessary is determined by (1) the amount of decrease in the pressing force when the predetermined time has elapsed, (2) the elapsed time until the predetermined amount of decrease, and (3) the pressing force when the predetermined time has elapsed. Even when a determination element such as a value or (4) elapsed time until reaching a predetermined pressing force value is used, the same effect as in the above embodiment can be obtained.

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 sectional drawing which shows the structure of the self-holding type solenoid used by this Embodiment. It is sectional drawing which shows the whole structure of the electric brake device which concerns on this invention. It is sectional drawing which expands and shows a part of this electric brake device. It is a circuit diagram which shows the controller of this electric brake device, and the member connected to this. It is a flowchart which shows the necessity determination process of the re-parking brake which the controller of FIG. 6 performs. FIG. 6 is a characteristic diagram showing a correspondence relationship between a pressing force reduction coefficient and a subsequent pressing force reduction amount. It is a figure which shows an example of the processing content of step S8 of FIG. 7 in a table format. It is a figure for demonstrating the pressing force-elapsed time characteristic of this Embodiment and a prior art example. It is a flowchart which shows the necessity determination process of the re-parking brake in other embodiment which a controller performs. It is a flowchart which shows the necessity determination process of the re-parking brake of the modification 1 which a controller performs. It is a flowchart which shows the necessity determination process of the re-parking brake of the modification 2 which a controller performs. It is a flowchart which shows the necessity determination process of the re-parking brake of the modification 3 which a controller performs. It is a flowchart which shows the necessity determination process of the re-parking brake of the modification 4 which a controller performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Carrier, 2 ... Caliper (brake body) 3, 4 ... Brake pad, 11 ... Piston, 12 ... Motor (electric device), 13 ... Ball ramp mechanism (rotation-linear motion conversion mechanism), 16 ... Parking brake lock Mechanism (pushing force holding mechanism), 26 ... motor rotor, 52 ... claw wheel, 56 ... engaging claw, 51 ... solenoid (actuator), 60 ... tooth portion, 100 ... controller (control device, pressing force drop predicting means, Re-parking brake operation control means, parking brake operation end means), 110 ... pressing force sensor (pressing force detection means), 112 ... timer (elapsed time measuring means), D ... disk rotor.

Claims (16)

A brake pad driven by an electric device is pressed against a disc rotor mounted on the wheel side, and the brake body is braked by this pressing force, and the parking brake is operated by holding the pressing force generated by the brake body. An electric brake device comprising: a pressing force holding mechanism to perform; a pressing force detection unit that detects a pressing force generated by the brake main body; and a control device that controls the electric device and the pressing force holding mechanism.
The controller is
An elapsed time measuring means for measuring an elapsed time of the parking brake operation by the pressing force holding mechanism;
Based on the value of the pressing force detected by said pressing force detecting means at the elapsed time and the elapsed time during which the elapsed time measuring means has measured the magnitude of the pressing force which the braking body occurs after than the elapsed time Pressing force drop prediction means for predicting ,
An electric brake device comprising: a parking brake operation ending unit that stops power supply based on a prediction result by the pressing force decrease prediction unit .   The pressing force decrease predicting means obtains a pressing force decreasing coefficient from the elapsed time measured by the elapsed time measuring means and the pressing force detected by the pressing force detecting means at the elapsed time, and based on the pressing force decreasing coefficient The electric brake device according to claim 1, wherein the magnitude of the pressing force generated by the brake body is predicted.   3. The electric brake device according to claim 2, wherein the pressing force reduction coefficient is a rate of change of the amount of reduction in pressing force detected by the pressing force detection means with respect to the elapsed time measured by the elapsed time measuring means. The parking brake operation ending means continues prediction by the pressing force decrease predicting means when the pressing force decrease coefficient is larger than a predetermined reference value based on a prediction result of the pressing force decrease predicting means. electric braking apparatus according to claim 3, wherein the reduction factor is characterized and Turkey to stop the power supply end to the control device the prediction by the pressing force reduction predicting means when less than the predetermined reference value.   3. The electric brake device according to claim 2, wherein the pressing force reduction coefficient is a rate of change in elapsed time measured by the elapsed time measuring unit with respect to an amount of decrease in pressing force detected by the pressing force detecting unit. The parking brake operation ending means continues prediction by the pressing force decrease predicting means when the pressing force decrease coefficient is smaller than a predetermined reference value based on the prediction result of the pressing force decrease predicting means, and the pressing force decreases. electric braking apparatus according to claim 5, wherein the reduction factor is characterized and Turkey to stop the power supply end to the control device the prediction by the pressing force reduction predicting means when greater than the predetermined reference value.   The pressing force decrease predicting means predicts the magnitude of the pressing force generated by the brake body from the amount of pressing force detected by the pressing force detecting means when the predetermined time measured by the elapsed time measuring means has elapsed. The electric brake device according to claim 1. The parking brake operation ending means continues prediction by the pressing force decrease prediction means when the amount of decrease in the pressing force is larger than a predetermined reference value based on the prediction result of the pressing force decrease prediction means, and electric braking apparatus according to claim 7, wherein the amount of reduction in force is characterized and Turkey to stop the power supply end to the control device the prediction by the pressing force reduction predicting means when less than the predetermined reference value .   The pressing force decrease predicting means is a magnitude of the pressing force generated by the brake body from an elapsed time measured by the elapsed time measuring means until a pressing force decrease amount detected by the pressing force detecting means reaches a predetermined amount. The electric brake device according to claim 1, wherein the electric brake device is predicted. The parking brake operation ending means continues prediction by the pressing force decrease predicting means when the elapsed time is smaller than a predetermined reference value based on the prediction result of the pressing force decrease predicting means, and the elapsed time is predetermined. electric braking apparatus according to claim 9, wherein the benzalkonium to stop the power supply end to the control device the prediction by the pressing force reduction predicting means when greater than the reference value.   The pressing force decrease predicting means predicts the magnitude of the pressing force generated by the brake main body from the value of the pressing force detected by the pressing force detecting means when a predetermined time elapsed measured by the elapsed time measuring means. The electric brake device according to claim 1. The parking brake operation ending means continues prediction by the pressing force decrease prediction means when the value of the pressing force is smaller than a predetermined reference value based on the prediction result of the pressing force decrease prediction means, and the pressing force It values electric braking apparatus according to claim 11, wherein the benzalkonium to stop the power supply end to the control device the prediction by the pressing force reduction predicting means when greater than the predetermined reference value.   The pressing force drop predicting means determines the magnitude of the pressing force generated by the brake body from the elapsed time measured by the elapsed time measuring means until the value of the pressing force detected by the pressing force detecting means reaches a predetermined value. The electric brake device according to claim 1, wherein prediction is performed. The parking brake operation ending means continues prediction by the pressing force decrease predicting means when the elapsed time is smaller than a predetermined reference value based on the prediction result of the pressing force decrease predicting means, and the elapsed time is predetermined. electric braking apparatus according to claim 13, wherein the benzalkonium to stop the power supply end to the control device the prediction by the pressing force reduction predicting means when greater than the reference value. In the control device, when the pressing force detecting means detects a value equal to or less than the required pressing force during the prediction of the pressing force drop predicting means, the electric device sets the pressing force to a value larger than the required pressing force. 15. The electric brake device according to claim 1, further comprising a re-parking brake operation control means. The electric device is a motor;
The brake body includes a caliper including a piston, the motor, and a rotation-linear motion conversion mechanism that converts the rotation of the rotor of the motor into a linear motion and transmits the linear motion, and the brake pad is a disc rotor. The piston is propelled according to the rotation of the rotor of the motor so as to press against the
The pressing force holding mechanism is provided so as to rotate together with the rotation of the rotor of the motor, and a tooth wheel in which a plurality of substantially chevron-shaped tooth portions are continuously formed in the circumferential direction on the outer peripheral portion;
An engaging claw disposed around the ratchet wheel and movably engaged with and disengaged from the toothed wheel;
An actuator for moving the engaging claw,
The electric brake device according to any one of claims 1 to 15, wherein the parking brake operation is performed by engagement of the engagement claw with the toothed wheel.

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