JP2009115313A - Disc brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disc brake capable of miniaturizing a motor and a master cylinder without using a plurality of calipers. <P>SOLUTION: This electronic control disc brake 1 has a hydraulic piston 9 arranged on the outer pad 7b side of the calipers 2 and pressing an outer pad 7b to a brake disc BD in response to brake hydraulic pressure, the motor 5 arranged on the inner pad 7a side of the calipers 2, and a ball screw mechanism 6 arranged on the inner pad 7a side of the calipers 2, converting torque of the motor 5 into translatory motion and pressing an inner pad 7a to the brake disc BD. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to the technical field of disc brakes that brake a wheel by pressing a pair of opposed pads against a brake disc that rotates integrally with the wheel.

As a conventional disc brake, for example, an electric disc brake and a hydraulic disc brake are provided on one wheel, and the braking force is shared between the two disc brakes, thereby reducing the size of the motor and the operating pressure generating means (master cylinder). (For example, refer to Patent Document 1).
JP 2004-351965 A

  However, in the above-described prior art, since two brake calipers are provided on one wheel, there is a problem that an increase in unsprung load accompanying an increase in the number of parts and a deterioration in mountability on a vehicle are involved.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a disc brake capable of reducing the size of the motor and the operating pressure generating means without using a plurality of calipers. is there.

  To achieve the above object, according to the present invention, a piston mechanism that is provided on the first pad side of the caliper and presses the first pad against the brake disc in accordance with the operating pressure generated according to the braking operation amount of the driver, and the caliper The electric motor provided on the second pad side and the second pad side of the caliper convert the rotational force of the electric motor into a linear motion, and at least the second pad of the first pad and the second pad is used as a brake disc. A movement converting mechanism for pressing.

  In the present invention, since the pair of pads are advanced and retracted by the piston mechanism and the electric motor, the motor and the operating pressure generating means can be reduced in size without using a plurality of calipers.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

[System configuration]
FIG. 1 is a system configuration diagram of a brake device to which an electronically controlled disc brake of the first embodiment is applied, and FIG. 2 is a front wheel side hydraulic circuit diagram of the brake device of the first embodiment.

  The brake device of the first embodiment includes electronically controlled disc brakes 1FL, 1FR that apply braking force to the left and right front wheels 100FL, 100FR, and electric disc brakes 101RL, 101RR that apply braking force to the left and right rear wheels 100RL, 100RR. Yes.

  Electronically controlled disc brakes 1FL and 1FR are equipped with left and right front wheels 100FL, depending on the brake fluid pressure from the master cylinder (working pressure generating means) M / C and the current supplied from the brake-by-wire (BBW) controller Apply braking force to 100FR. The structure of the electronically controlled disc brakes 1FL and 1FR will be described later.

  The electric disc brakes 101RL and 101RR apply a braking force to the left and right rear wheels 100RL and 100RR according to the current supplied from the BBW controller BBB / ECU. The electric disc brakes 101RL and 101RR are structured by using a general one that presses a pad against a brake disc by a motor, such as an electric disc brake described in JP-A-2002-205634. The description about is omitted.

  The brake pedal BP is connected to an input rod (not shown) of the master cylinder M / C. A reservoir RS for storing brake fluid is connected to the master cylinder M / C. The driver's brake operation is detected by the brake lamp switch BS and sent to the BBW controller BBW / ECU.

  The primary chamber PRI of the master cylinder M / C is connected to the hydraulic piping 102FL communicating with the cylinder chamber 9a (see FIG. 3) of the hydraulic piston 9 of the electronically controlled disc brake 1FL of the left front wheel 100FL and the stroke simulator SS. And a hydraulic pipe (communication path) 103. The secondary chamber SEC of the master cylinder M / C is connected to a hydraulic pipe 102FR communicating with the cylinder chamber 9a of the hydraulic piston 9 of the electronically controlled disc brake 1FR of the right front wheel 100FR.

  A normally open solenoid-in valve (flow control valve) 104FL that maintains and shuts off the communication between the master cylinder M / C and the electronically controlled disc brakes 1FL, 1FR on the hydraulic piping (working pressure supply passage) 102FL, 102FR 104FR and pressure sensors 105FL, 105FR for detecting the master cylinder pressure. A shutoff valve 106 is provided on the hydraulic pipe 103 to maintain and shut off the communication state between the master cylinder M / C and the stroke simulator SS.

  The BBW controller BBW / ECU has a wheel speed sensor 107FL, 107FR, 107RL that detects the signal from the brake lamp switch BS, the signal from the pressure sensor 105FL, 105FR, and the wheel speed of each wheel 100FL, 100FR, 100RL, 100RR. , 107RR and a signal from the acceleration sensor 107 that detects vehicle acceleration are input.

  BBW controller BBW / ECU calculates normal brake control according to the driver's pedal operation based on input signals from each sensor, anti-skid brake control (ABS), vehicle behavior stabilization control (VDC), and inter-vehicle distance control And calculation to control tire slip and vehicle behavior using vehicle information such as obstacle avoidance control control, calculate the braking force required for the vehicle, and is necessary for each wheel 100FL, 100FR, 100RL, 100RR Calculate the braking force target value. Then, each braking force target value is output to the brake controller B / ECU (braking force control means) of the electronic control disc brakes 1FL and 1FR and the controller (not shown) of the electric disc brakes 101FL and 101FR.

[Configuration of electronically controlled disc brake]
3 is a side sectional view of the electronically controlled disc brake of the first embodiment, FIG. 4 is a plan view of the electronically controlled disc brake, and FIG. 5 is a front view of the electronically controlled disc brake.
The electronic control disc brakes 1FL and 1FR (hereinafter referred to as electronic control disc brake 1) according to the first embodiment include a main housing (base portion) 3, an end housing 4, a motor (electric motor) 5, and a ball screw mechanism. (Motion conversion mechanism) 6, a pair of pads 7 (an inner pad (second pad) 7a, an outer pad (first pad) 7b), a bridge (first pad support portion) 8, and a hydraulic piston ( Piston mechanism) 9. The main housing 3, the end housing 4, and the bridge 8 constitute the caliper 2 of the first embodiment.

  The main housing 3 is supported so as to be relatively displaceable in the wheel axial direction (= the axial direction of the brake disc BD) with respect to the carrier CR fixed to the vehicle body side member. A hollow portion 3a is formed inside the main housing 3, and a motor 5, a ball screw mechanism 6 and a thrust sensor (pressure detecting means) 10 (10FL, 10FR) are accommodated. The electronically controlled disc brake 1 according to the first embodiment is a floating disc brake having a floating caliper in which a main housing 3 of the caliper 2 is supported so as to be relatively displaceable in the wheel axis direction with respect to the carrier CR.

  The motor 5 includes a motor stator 5a, a motor rotor (rotating member) 5b, and a rotation angle sensor 5c. The motor stator 5a is fixed to the main housing 3, and the motor rotor 5b is provided to be rotatable around the wheel axis direction with respect to the motor stator 5a. The rotation angle sensor 5c detects the rotation angle (number of rotations) of the motor rotor 5b with respect to the motor stator 5a, and outputs a detection signal to the brake controller B / ECU.

  The ball screw mechanism 6 includes a ball screw nut 6a, a screw shaft (straight advance member) 6b, and a plurality of balls 6c. The ball screw nut 6a is provided integrally with the motor rotor 5b, and is supported by the front bearing 11a and the end bearing 11b so as to be rotatable around the wheel axis direction. The front bearing 11 a is fixed to the main housing 3, and the end bearing 11 b is supported by a bearing holder 12 interposed between the end bearing 11 b and the end housing 4. The screw transmission mechanism of the first embodiment is configured by the ball screw nut 6a, the screw shaft 6b and the ball 6c.

The bearing holder 12 is provided so as to be relatively displaceable in the wheel axis direction with respect to the main housing 3. A thrust sensor 10 is interposed between the bearing holder 12 and the end housing 4.
The screw shaft 6b is screwed through a ball screw nut 6a and a plurality of balls 6c, and an inner pad 7a is attached to the tip.

  As shown in FIGS. 3 and 6, the ball screw mechanism 6 includes a latch groove 13a formed on the outer periphery of the ball screw nut 6a, a solenoid 13b, and the solenoid 13b. A latch mechanism (locking means) 13 including a latch 13c to be engaged is provided.

The bridge 8 extends from the main housing 3 to the outer pad 7b side across the brake disc BD, and supports the outer pad 7b via the hydraulic piston 9.
The hydraulic piston 9 includes a cylinder chamber 9a formed in the bridge 8 and a piston 9b that slides in the cylinder chamber 9a. The cylinder chamber 9a communicates with the master cylinder M / C through the hydraulic pipe 102 (102FL, 102FR) formed in the bridge 8 and the main housing 3. A solenoid-in valve 104 (104FL, 104FR) that opens and closes the hydraulic pipe 102 is attached to the main housing 3.

  The piston 9b extends in the wheel axis direction according to the brake fluid pressure supplied from the master cylinder M / C to the cylinder chamber 9a, so that the outer pad 7b fixed at the tip is pressed against the brake disc BD.

  The brake controller B / ECU calculates the pressing force of the brake disc BD by the inner pad 7a and the outer pad 7b based on the signals from the thrust sensors 10FL and 10FR, and the calculated pressing force is sent from the BBW controller BBW / ECU. The motor 5 is controlled while feeding back the signal of the rotation angle sensor 5c so that the pressing force corresponding to the braking force target value is obtained.

  As shown in FIG. 7, the brake controller B / ECU refers to the signals from the thrust sensor 10 and the pressure sensor 105, and in the control region where the motor 5 actually operates, the motor pressing force (ball screw) by the output of the motor 5 The motor 5 is controlled so that the pressing force of the mechanism 6 is larger than the hydraulic piston pressing force (pressing force of the hydraulic piston 9) by the hydraulic piston 9 corresponding to the pedal stroke.

  Also, the brake controller B / ECU closes the solenoid-in valves 104FR and 104FR when the BBW controller BBW / ECU (ABS control means) performs ABS control, and the cylinder of the hydraulic piston 9 from the master cylinder M / C. The supply of brake fluid pressure to the chamber 9a is shut off. At the same time, the shut-off valve 106 is opened and the brake fluid pressure is absorbed by the stroke simulator SS, thereby enabling the driver's pedal stroke.

  Further, the brake controller B / ECU drives the solenoid 13b to engage the latch 13c with the latch groove 13a when the voltage of the motor 5 decreases or when the self-holding control is performed due to the temperature increase, and the inner pad 7a is connected to the brake disc BD. The rotational displacement of the ball screw nut 6a in the direction away from the rotation is regulated.

Next, the operation will be described.
[Normal braking]
FIG. 8 is a time chart illustrating the braking force generation operation of the first embodiment.
At time t1, the driver starts to depress the brake pedal BP, so that the brake fluid in the master cylinder M / C is supplied from the hydraulic pipe 102 (102FL, 102FR) to the cylinder chamber 9a of the hydraulic piston 9 according to the pedal stroke amount. The piston 9b starts to expand.

  At time t2, the BBW controller BBW / ECU detects the driver's brake operation from the signal of the brake lamp switch BS, and also reads the detection value of the pressure sensor 105 a preset number of times, so from the detection value of the pressure sensor 105 The braking force target value of each wheel is calculated, and the braking force target value is transmitted to each brake controller B / ECU. The brake controller B / ECU starts driving the motor 5.

  At time t3, since the dead time for starting the motor has elapsed, the motor 5 starts to rotate in the forward direction. Here, the “forward rotation direction” refers to the rotation direction of the motor 5 that advances the inner pad 7a toward the brake disc BD. As the motor 5 rotates, the ball screw nut 6a provided integrally with the motor rotor 5b rotates, and the screw shaft 6b starts moving forward.

  At this time, the outer pad 7b starts to press the brake disc BD while filling the gap with the brake disc BD. The reaction force (pressing reaction force) of the pressing force of the brake disc BD by the outer pad 7b is transmitted in the order of the bridge 8, the main housing 3, the end housing 4, and the bearing holder 12. At this time, the force with which the end housing 4 pushes the bearing holder 12, that is, the hydraulic piston pressing force, is detected by the thrust sensor 10 and sent to the BBW controller BBW / ECU.

  At time t4, the inner pad 7a fills the gap with the brake disc BD and starts to press the brake disc BD. As a result, the brake disc BD receives frictional resistance from the inner pad 7a and the outer pad 7b, so that a brake pressing force is generated and a braking force is applied to the wheel.

  The reaction force for pressing the brake disc BD by the inner pad 7a is transmitted from the screw shaft 6b → the ball screw nut 6a → the end bearing 11b → the bearing holder 12 → the end housing 4 → the main housing 3. At this time, the force with which the bearing holder 12 pushes the end housing 4, that is, the motor pressing force is detected by the thrust sensor 10 and sent to the BBW controller BBW / ECU. That is, the thrust sensor 10 can detect the sum of the hydraulic piston pressing force generated in response to the pedal operation and the motor pressing force generated by the motor output.

  Since the main housing 3 can be displaced relative to the carrier CR in the wheel axis direction, the main housing 3 moves in the direction opposite to the traveling direction of the screw shaft 6 b by the pressing reaction force transmitted from the end housing 4 and pulls the bridge 8. Thereby, the pressing reaction force of the inner pad 7a can be made to act as the pressing force of the outer pad 7b.

  Here, in the conventional electric disc brake using a floating caliper, the inner pad starts moving forward at time t3, the gap with the brake disc is filled at time t4, and the outer pad is drawn to the brake disc by the pressing force of the inner pad. At the time t5, the brake pressing force was not generated until the difference between the outer pad and the brake disc was filled. That is, there is a problem in terms of initial response from the motor stop until the brake pressing force is generated.

  On the other hand, in the electronically controlled disc brake 1 of the first embodiment, since the hydraulic piston 9 that moves forward according to the pedal stroke of the driver is provided on the outer pad 7b side, when the inner pad 7a starts moving forward at time t3, The outer pad 7b has already filled the gap with the brake disc BD. Therefore, when the inner pad 7a fills the gap with the brake disc BD at the time t4, a brake pressing force can be generated, and the initial response can be improved as compared with the conventional electric disc brake.

  Normally, there is a gap between the caliper 2 and the brake disc BD due to the thermal collapse of the brake disc BD or knockback. In the electronic control disc brake 1 of the first embodiment, the gap is pushed out by the hydraulic piston 9. Since it is filled with the sum of the speed and the pushing speed of the electric brake, the braking response can be improved.

  In a driving scene where a sudden pedal operation is not performed, such as slow braking, the hydraulic pressure is detected in the pedal operation before the motor 5 is driven after the brake operation of the driver is detected (before the pedal operation detection time + the motor operation dead time elapses). The piston 9 advances the piston 9b according to the pedal stroke. In the first embodiment, since the motor 5 is driven so that the motor pressing force is larger than the hydraulic piston pressing force, when the inner pad 7a presses the brake disc BD, the piston 9b moves backward on the outer pad 7b side and the bridge 8 It will be in the state stuck to the surface position (bottomed state) (FIG. 9). For this reason, since it is possible to suppress the fluctuation of the hydraulic pressure due to the vibration of the piston 9b even when the brake judder is generated, only the hydraulic pressure corresponding to the pedal stroke can be detected by the pressure sensor 105. The pressing force can be accurately grasped.

  On the other hand, when a sudden pedal operation is performed, since the brake fluid is sent to the hydraulic piston 9 in accordance with the pedal stroke speed, the hydraulic piston 9 moves forward without delay, and the outer pad 7b is connected to the brake disc BD. Fill the gap.

  As shown in FIG. 10, the BBB controller / ECU detects that the brake pedal BP is operated from the signal of the brake lamp switch BS and sufficiently detects the brake pedal stroke from the detection signal of the pressure sensor 105. After detecting the number of avoidable times, the braking force target value is output to the brake controller B / ECU of the electronically controlled disc brake 1. In the brake controller B / ECU, the comparison with the detection signal of the thrust sensor 10 is performed, the motor output is calculated, and the control of the motor 5 is started. The motor 5 starts to move after the dead time for starting the motor and advances the screw shaft 6b.

  At this time, the hydraulic piston 9 fills the gap with the brake disc BD and starts to draw the screw shaft 6b in the forward direction by the pressing reaction force from the brake disc BD. The piston 9 stops moving forward and is pushed back by the screw shaft 6b while maintaining the pressing force and starts moving backward.

  By performing the above operation, the amount of movement of the screw shaft 6b can be halved and the responsiveness can be improved as compared with a conventional device having a separate hydraulic caliper and electric brake caliper. Further, since the braking force can be generated by adding the output of the motor 5 and the output of the hydraulic piston 9, the motor 5 and the master cylinder M / C can be downsized without using a plurality of calipers. .

[Securing the cross-sectional area of the piston]
In the electronically controlled disc brake 1 according to the first embodiment, since the electric brake and the hydraulic brake are used in combination with normal braking not when the electric brake fails, the inner pad 7a side is sandwiched between the brake disc BD. A motor 5 and a ball screw mechanism 6 are arranged, and a hydraulic piston 9 is arranged on the outer pad 7b side.

  That is, in order to use the hydraulic brake for normal braking, it is necessary to increase the output (hydraulic piston pressing force) in order to ensure the braking force. In order to increase the output, it is necessary to increase the cross-sectional area of the piston 9b in contact with the brake fluid as much as possible. Here, for example, when the piston is disposed on the inner pad side together with the motor and the ball screw mechanism, most of the caliper sectional area is eroded by the electric brake mechanism including the motor and the ball screw mechanism, so that the piston sectional area is increased. I can't.

  On the other hand, in the electronically controlled disc brake 1 of the first embodiment, the hydraulic piston 9 and the electric brake mechanism are arranged at positions facing each other with the brake disc BD interposed therebetween, so that the caliper cross-sectional area does not interfere with the electric brake mechanism. A large piston cross-sectional area can be secured by fully using (the cross-sectional area of the bridge 8), and the braking force of the hydraulic brake necessary for normal braking can be obtained.

[ABS operation]
The brake controller B / ECU closes the solenoid-in valve 104 during ABS operation so that the brake fluid pushed out from the master cylinder M / C does not act on the hydraulic piston 9, and the BBB controller Bbw / ECU The motor pressing force is increased or decreased according to the braking force target value. Thereby, highly accurate ABS control becomes possible.

  At this time, the brake pedal BP is in the state of being stepped on the plate (a state where the pedal cannot be depressed even if the pedal is depressed), so the shut-off valve 106 is opened and the brake fluid is absorbed by the stroke simulator SS, so The deterioration of feeling can be prevented.

[When motor output drops]
The brake controller B / ECU drives the solenoid 13b and latches the latch 13c when the output of the motor 5 decreases, such as when the self-protection control intervenes due to the voltage decrease of the motor 5 or the temperature increase of the motor 5. Engage with the groove 13a. As a result, the motor pressing force immediately before the latch mechanism 13 is operated is maintained, and the driver further increases the brake pedal BP, thereby increasing the hydraulic piston pressing force while maintaining the motor pressing force. Power can be increased. In other words, even when the motor 5 becomes inoperable during braking, a braking force larger than the braking force generated only by the hydraulic piston 9 can be generated, so that the vehicle can be driven only by the hydraulic piston pressing force. The braking distance can be shortened compared to the case of stopping.

  At this time, if the shutoff valve 106 is open, the shutoff valve 106 is closed and the stroke simulator SS is disconnected from the master cylinder M / C, so that the brake fluid generated in the master cylinder M / C is transferred to the hydraulic piston 9. The required liquid chamber capacity of the master cylinder M / C can be reduced.

Next, the effect will be described.
The disc brake according to the first embodiment has the following effects.

  (1) A hydraulic piston 9 that is provided on the outer pad 7b side of the caliper 2 and presses the outer pad 7b against the brake disc BD according to the brake hydraulic pressure; a motor 5 provided on the inner pad 7a side of the caliper 2; A ball screw mechanism 6 that is provided on the pad 7a side, converts the rotational force of the motor 5 into a linear motion, and presses the inner pad 7a against the brake disc BD. As a result, the motor 5 and the master cylinder M / C can be reduced in size without using a plurality of calipers.

  (2) A braking force obtained by adding the braking force generated by the pressing force of the hydraulic piston 9 and the braking force generated by the pressing force of the ball screw mechanism 6 becomes a target value of the wheel braking force based on the brake stroke. A brake controller B / ECU for controlling the motor 5 is provided. Accordingly, a braking force that matches the driver's required braking force can be applied to the wheel.

  (3) Since the brake controller B / ECU controls the motor 5 so that the motor pressing force is greater than the hydraulic piston pressing force, it can accurately grasp the hydraulic piston pressing force even when the brake judder occurs, and the brake stroke Accordingly, the motor 5 can be accurately controlled.

  (4) The brake controller B / ECU closes the solenoid-in valve 104 provided on the hydraulic pipe 102 that connects the master cylinder M / C and the cylinder chamber 9a of the hydraulic piston 9 during ABS operation. More precise ABS control can be performed by increasing or decreasing only the motor pressing force without causing the brake fluid pushed out from the M / C to act on the hydraulic piston 9.

  (5) The stroke simulator SS is installed on the hydraulic pipe 102 and absorbs the operating pressure generated by the master cylinder M / C during ABS operation. Deterioration can be prevented.

  (6) Since the shutoff valve 106 is provided on the hydraulic pipe 103 that communicates the hydraulic pipe 102 and the stroke simulator SS, the amount of liquid consumed by the stroke simulator is reduced and the amount of liquid consumed by the hydraulic piston 9 is increased. Thus, the required liquid chamber capacity of the master cylinder M / C can be reduced, and the master cylinder M / C can be downsized.

  (7) A latch mechanism 13 capable of restricting rotational displacement in the direction in which the inner pad 7a is separated from the brake disc BD by engagement with the ball screw mechanism 6 is provided, and the brake controller B / ECU operates when the output of the motor 5 decreases The latch mechanism 13 is engaged with the ball screw mechanism 6. As a result, when the motor output decreases, the position of the inner pad 7a is fixed, and the pressing force of the hydraulic piston 9 is prevented from escaping by the hydraulic pressure from the master cylinder M / C. A braking force can be secured.

  (8) Since the caliper 2 is a floating caliper supported so as to be capable of relative displacement in the wheel axis direction with respect to the carrier CR, it is possible to improve the initial responsiveness from the start of the brake depression to the occurrence of the brake pressing force.

  (9) A thrust sensor 10 for detecting pressure acting in the wheel axis direction is provided between the bearing holder 12 and the end housing 4 in the wheel axis direction, and the brake controller B / ECU has a thrust detected by the thrust sensor 10. The motor 5 is controlled so that it becomes a value according to the braking force target value of the wheel based on the brake stroke. As a result, the rotation angle of the motor 5 can be controlled based on the actual measurement value of the sum of the hydraulic piston pressing force and the motor pressing force generated by the motor output, so that the conventional motor pressing force is estimated from the motor rotation angle. Compared with an electric disc brake, the accuracy of brake control can be further increased.

  The brake device of the second embodiment is different from the first embodiment only in the configuration of the electronically controlled disc brake, and the system configuration is the same as that of the first embodiment.

[Configuration of electronically controlled disc brake]
11 is a side sectional view of the electronically controlled disc brake of the second embodiment, FIG. 12 is a plan view of the electronically controlled disc brake, FIG. 13 is a front view of the electronically controlled disc brake, and FIG. 14 is a rear view of the electronically controlled disc brake. .
Note that the same reference numerals in the second embodiment denote the same parts as in the first embodiment, and a description thereof will be omitted.

  The electronic control disc brake 20 according to the second embodiment is fixed to a vehicle body side member such as an axle at a position inside the vehicle disc in the vehicle width direction with respect to the brake disc BD rotating with wheels (not shown). A housing (base portion) 21 and a caliper 22 supported by the housing 21 so as to be movable along the wheel axis direction are provided.

  The caliper 22 includes a bridge portion (first pad support portion) 23 provided across the outer periphery of the brake disc BD, and a cylindrical cylinder extending inward in the vehicle width direction with respect to the bridge portion 23. Part (second pad support part) 24. The electronically controlled disc brake 20 according to the second embodiment is an opposed cylinder disc brake having a fixed caliper in which a housing 21 that supports the caliper 22 is fixed to the carrier CR in a position unchanged in the wheel axis direction.

In the cylinder portion 24, a cylindrical piston 26 is slidably disposed so as to face one sliding surface 25a facing the inner side in the vehicle width direction of the brake disc BD. An O-ring 34 is attached to a circumferential groove formed on the inner circumferential surface of the cylinder portion 24.
A caliper claw 28 is formed outside the bridge portion 23 in the vehicle width direction so as to face the other sliding surface 25b facing the outside in the vehicle width direction of the brake disc BD.
The inner pad 7a is fixed to the piston 26 and faces one sliding surface 25a of the brake disc BD, and the caliper pawl 28 is connected to the outer pad 7b via the hydraulic piston 9 having the same configuration as that of the first embodiment. Is fixed. The outer pad 7b faces the other sliding surface 25b of the brake disc BD.

  The housing 21 bulges outward from a part of the outer periphery of the housing body 29 and has a cylindrical housing body 29 provided with openings in the direction facing both the outside and the inside in the vehicle width direction, and generates a rotational force. A motor housing 32 having a built-in motor 30 and a reduction planetary gear mechanism 31 and a controller housing 33 that closes an opening of the housing main body 29 that faces inward in the vehicle width direction are provided.

In addition, the cylinder portion 24 of the caliper 22 is slidably inserted into the housing main body 29 from the opening side that opens toward the outside in the vehicle width direction. At this time, a screw portion of a rotation restricting bolt (not shown) of the housing body 29 is inserted into a guide hole (not shown) provided in the caliper 22. Accordingly, the caliper 22 is movable in the wheel axis direction by sliding the cylinder portion 24 in the housing main body 29 while the rotation is regulated by the rotation regulating bolt inserted through the guide hole. An O-ring 34 is attached to a circumferential groove formed on the inner circumferential surface near the opening on the outside of the housing body 29 in the vehicle width direction.
A screw transmission mechanism (motion conversion mechanism) that converts the rotational force transmitted from the reduction planetary gear mechanism 31 into a linear force and transmits it to the piston 26 and the caliper pawl 28 is disposed in the housing body 29.

  The screw transmission mechanism includes a ball screw screw (second rectilinear member) 35 fixed coaxially to the piston 26, a ball screw nut (first rectilinear member) 36 engaged with the ball screw screw 35 with a rolling screw, A trapezoidal screw screw 37 engaged with the ball screw screw 35 with a slide screw, and an output gear (rotation) for transmitting the rotational force transmitted from the reduction planetary gear mechanism 31 to the trapezoidal screw screw 37 and the ball screw nut 36. Member) 38.

  The output gear 38, the ball screw nut 36, and the ball 39 constitute the first screw transmission mechanism of the second embodiment. The trapezoidal screw screw 37, the ball screw screw 35, and the ball 39 constitute the second screw transmission mechanism of the second embodiment.

  The ball screw screw 35 is a hollow rod-shaped member that is closed at one end in the longitudinal direction and opened at the other end. A thread groove is formed on the outer peripheral surface of the ball screw screw 35, and a trapezoidal screw-shaped female screw 35a is formed on the inner peripheral surface of the opening provided at the other end. One end of the ball screw screw 35 is fixed to the axial center position of the piston 26.

  The ball screw nut 36 is a cylindrical member, and a screw groove corresponding to the screw groove of the ball screw screw 35 is formed on the inner peripheral surface thereof. The screw groove of the ball screw screw 35 and the ball screw nut 36 A large number of balls 39 are interposed between the thread grooves. Seal members 40 for preventing contamination from entering the ball rolling surface (surface of the screw groove) are interposed at both ends between the screw groove of the ball screw screw 35 and the screw groove of the ball screw nut 36. ing.

  A pair of angular ball bearings 41 is interposed between the inner peripheral surface of the cylinder portion 24 and the outer periphery of the ball screw nut 36 in a state of being combined in the back direction in the axial direction. The cylinder portion 24 is rotatably supported while the movement in the direction is restricted. A spline groove 36 a is formed on the outer periphery of the ball screw nut 36 adjacent to the output gear 38.

  The trapezoidal screw screw 37 is a rod-like member in which a trapezoidal screw-shaped male screw 37a is formed on the outer periphery on one end side, and an output gear 38 constituting the reduction planetary gear mechanism 31 is fixed on the other end side. That is, a flange portion 37b is formed on the other end side of the male screw 37a of the trapezoidal screw screw 37, a spline groove is formed on the outer periphery further on the other end side than the flange portion 37b, and a screw is formed on the other end. Yes.

  The male screw 37 a of the trapezoidal screw screw 37 is a hollow portion provided in the ball screw screw 35 while being screwed into a trapezoidal screw-shaped female screw 35 a formed on the inner peripheral surface of the opening at the other end of the ball screw screw 35. It has entered 35b. Further, the spline groove provided in the shaft hole of the output gear 38 is spline-coupled to the spline groove of the trapezoidal screw screw 37, and the fixing nut 42 is fastened to the male screw formed at the other end of the trapezoidal screw screw 37. The toothed gear 38 is fixed to the other end of the trapezoidal screw screw 37 while being pressed against the flange portion 37b.

The output gear 38 is rotatably supported by a bearing 43 disposed on the inner wall of the housing main body 29 and the controller housing 33 while the movement in the axial direction is restricted, and the rotation of the output gear 38 is transmitted to the trapezoidal screw screw 37. Then, it is converted as a straight advance force of the ball screw screw 35.
A cylindrical rotation transmission portion 38a is formed on the outer diameter side of the output gear 38, and a spline groove 38b is formed on the inner peripheral surface of the rotation transmission portion 38a. The spline groove 38b of the rotation transmitting portion 38a is splined with a spline groove 36a formed on the outer periphery of the ball screw nut 36. As a result, the rotational force of the output gear 38 transmitted via the rotation transmitting portion 38 a is converted as a straight force of the ball screw nut 36.

  Here, the screw winding direction of the ball screw screw 35 and the ball screw nut 36 and the screw winding direction of the female screw 35a formed on the inner peripheral surface of the opening of the trapezoidal screw screw 37 and the ball screw screw 35 are set in the same direction. . Therefore, when the rotational force is simultaneously transmitted from the output gear 38 to the trapezoidal screw screw 37 and the ball screw nut 36, one of the ball screw screw 35 and the ball screw nut 36 goes straight to the brake disc BD side, and the other Will go straight away from the brake disc BD.

  The screw leads of the ball screw screw 35 and the ball screw nut 36 are trapezoidal screw screw 37 and female screw 35a so that the linear movement distance of the ball screw nut 36 is twice the linear movement distance of the ball screw screw 35. It is set larger than the screw lead.

  On the other hand, the motor 30 disposed in the motor housing 32 is press-fitted and fixed to the outer periphery of the ring-shaped stator 30 a fixed to the inner peripheral surface of the motor housing 32 and the main shaft 44, and the stator 30 a together with the main shaft 44. It is comprised by the substantially cylindrical rotor 30b arrange | positioned coaxially and rotatably inside. The motor housing 32 is provided with a rotation angle sensor 49 that detects the rotation angle (number of rotations) of the motor 30.

  The reduction planetary gear mechanism 31 includes the aforementioned main shaft 44 functioning as a sun gear (hereinafter referred to as a sun gear 44), a ring gear 45 fixed to the inner peripheral surface of the motor housing 32, and the sun gear 44 and the ring gear 45. It is a single pinion type planetary gear provided with a plurality of pinions 46 meshing with each other and a carrier 47 supporting the plurality of pinions 46. A gear is formed on the outer periphery of the carrier 47, and the output gear 38 disposed in the housing main body 29 meshes with the carrier 47.

  Further, the controller housing 33 is integrated with the housing body 29 so as to close the inner opening of the housing body 29 in the vehicle width direction, but the other end of the trapezoidal screw screw 37 constituting the screw transmission mechanism. The inner wall of the controller housing 33 facing the side end surface is recessed in a direction away from the end surface. Thereby, the air absorption chamber 48 is provided at a position facing the end face on the other end side of the trapezoidal screw screw 37.

  The brake controller B / ECU arranged in the controller housing 33 estimates the motor pressing force from the detection value of the rotation angle sensor 49 that detects the rotation angle of the motor 30, and presses the hydraulic piston from the detection value of the pressure sensor 105. By estimating the force, the pressing force of the brake disc BD by the inner pad 7a and the outer pad 7b is calculated, and the motor so that the calculated pressing force becomes the pressing force corresponding to the braking force target value sent from the BBW controller BBW / ECU. 5 is controlled.

Next, the operation will be described.
[Normal braking]
When the driver starts to depress the brake pedal BP, the brake fluid of the master cylinder M / C is supplied from the hydraulic pipe 102 (102FL, 102FR) to the cylinder chamber 9a of the hydraulic piston 9 according to the pedal stroke amount. The piston 9b starts moving forward.

  The BBW controller BBW / ECU detects the driver's brake operation from the signal of the brake lamp switch BS and reads the detection value of the pressure sensor 105 for a preset number of times. The target value is calculated, and the braking force target value is transmitted to each brake controller B / ECU. The brake controller B / ECU rotates the motor 5 normally according to the braking force target value.

  When the rotor 30 b of the motor 30 rotates to a predetermined rotational speed, the rotational force is transmitted to the reduction planetary gear mechanism 31. Since the reduction planetary gear mechanism 31 has the ring gear 45 fixed, the reduced planetary gear mechanism 31 has a rotational force increased while being decelerated, and the rotational force is simultaneously transmitted from the output gear 38 to the trapezoidal screw screw 37 and the ball screw nut 36.

When the trapezoidal screw screw 37 receives the rotational force from the output gear 38, the ball screw screw 35 advances straight toward the outside in the vehicle width direction. As the ball screw screw 35 goes straight, the piston 26 goes straight outward in the vehicle width direction.
On the other hand, the ball screw nut 36 to which the rotational force is transmitted from the output gear 38 via the rotation transmission portion 38a goes straight inward in the vehicle width direction opposite to the direction in which the ball screw screw 35 goes straight. Here, since the ball screw nut 36 is integrated with the cylinder portion 24 of the caliper 22 via the pair of angular ball bearings 41, when the ball screw nut 36 advances straight inward in the vehicle width direction, the caliper 22 The caliper pawl 28 also moves inward in the vehicle width direction.

  The ball screw nut 36 moves inward in the vehicle width direction with a linear movement distance that is twice the linear movement distance of the ball screw screw 35 while moving linearly outward in the vehicle width direction together with the ball screw screw 35. Therefore, the straight movement of the caliper pawl 28 toward the inside in the vehicle width direction is amplified.

  Thus, the piston 26 moves to the outside of the vehicle width to press the inner pad 7a against one sliding surface 25a of the brake disc BD, and the caliper pawl 28 also moves to the inside in the vehicle width direction to brake the outer pad 7b. A braking force is generated by pressing against the other sliding surface 25b of the disk BD.

  By performing the above operation, the amount of movement of the ball screw nut 36 can be reduced and the responsiveness can be improved as compared with a conventional device having a separate hydraulic caliper and electric brake caliper. Further, since the braking force can be generated by adding the output of the motor 30 and the output of the hydraulic piston 9, the motor 5 and the master cylinder M / C can be downsized without using a plurality of calipers. .

  Further, since the hydraulic piston 9 and the electric brake mechanism are arranged at positions facing each other with the brake disc BD interposed therebetween, the caliper cross-sectional area (the cross-sectional area of the bridge 8) is fully used without interfering with the electric brake mechanism. The piston cross-sectional area can be secured, and the braking force of the hydraulic brake necessary for normal braking can be obtained.

  Further, since the electronically controlled disc brake 20 according to the second embodiment is an opposed cylinder type disc brake having a fixed caliper, it is possible to prevent the outer pad 7b from being dragged when the brake is released. That is, in the floating electric disc brake having the conventional floating caliper, when the driver stops the brake operation, the inner pad can be moved backward by reversing the motor. However, since the displacement of the outer pad depends on the brake disc pressing reaction force of the inner pad, the reverse movement is stopped when the pressing reaction force is no longer input to the inner pad. Therefore, even after the brake is released, the outer pad may be in contact with the brake disc, and drag may occur.

  On the other hand, in the second embodiment, the outer pad 7b can be moved forward / backward by the forward / reverse rotation of the motor 30, so that drag due to contact between the outer pad 7b and the brake disc BD can be prevented.

Next, the effect will be described.
In addition to the effects (1) to (6) of the first embodiment, the disk brake of the second embodiment has the following effects.

  (10) Since the caliper 22 is a fixed caliper, it is possible to prevent dragging due to contact between the outer pad 7b and the brake disc BD when the brake is released.

FIG. 15 is a front-wheel hydraulic circuit diagram of the brake device of the third embodiment.
In the third embodiment, a pedal stroke sensor 108 for detecting the stroke amount of the brake pedal BP is added to the configuration of the first embodiment shown in FIG. 2, and an electronically controlled disc brake is installed according to the stroke amount of the brake pedal BP. It differs in the point to control. Since other system configurations and the configuration of the electronically controlled disc brake are the same as those in the first embodiment, illustration and description are omitted.

[Brake control processing]
FIG. 16 is a flowchart showing a flow of a brake control process executed by the BBW controller BBB / ECU and each brake controller B / ECU of the third embodiment. Each step will be described below. This control process is repeatedly executed at a predetermined control cycle.

  In step S1, the BBB controller / BBW / ECU reads the stroke amount of the brake pedal BP from the pedal stroke sensor 108, and proceeds to step S2.

  In Step S2, it is determined in the BBW controller BBW / ECU whether or not the stroke amount read in Step S1 is larger than the control threshold value. If YES, the process proceeds to step S3. If NO, the process proceeds to step S13. Here, the control threshold value is a value corresponding to the play of the brake pedal BP.

  In step S3, the BBB controller / ECU calculates the required braking force (braking force required for the vehicle) according to the stroke amount read in step S1, and the wheels 100FL, 100FR, 100RL, The braking force target value of 100RR is calculated, and the calculated braking force target value is output to the brake controller B / ECU and the electric disc brakes 101RL and 101RR, and the process proceeds to step S4. Here, as shown in FIG. 17, each braking force target value is set such that the caliper pressing force of the front wheels is always larger than the caliper pressing force of the rear wheels with respect to the total braking force (required braking force).

  In step S4, the brake controller B / ECU calculates the pressing force of the brake disc BD by the inner pad 7a and the outer pad 7b based on the signals of the thrust sensors 10FL and 10FR, and the process proceeds to step S5.

  In step S5, while each brake controller B / ECU feeds back the signal of the rotation angle sensor 5c so that the calculated pressing force becomes a pressing force corresponding to the braking force target value sent from the BBW controller BBB / ECU. Then, the motor 5 is operated, and the process proceeds to step S6. At this time, the motor pressing force (the pressing force of the ball screw mechanism 6) by the output of the motor 5 becomes larger than the hydraulic piston pressing force (the pressing force of the hydraulic piston 9) by the hydraulic piston 9 corresponding to the pedal stroke. Thus, the motor 5 is controlled.

  In step S6, each brake controller B / ECU calculates the pedal stroke speed from the difference between the stroke amount of the brake pedal BP read in the previous control cycle and the current stroke amount read in step S1, and step S7 Migrate to The process of step S6 corresponds to an operation amount change speed detecting means.

  In step S7, each brake controller B / ECU determines whether the pedal stroke speed calculated in step S6 is higher than the solenoid-in valve closing threshold. If YES, the process moves to step S8, and if NO, the process moves to step S15. Here, the solenoid-in valve closing threshold is, for example, 30 mm / s.

  In step S8, the master cylinder pressure detected by the pressure sensors 105FL and 105FR is read in each brake controller B / ECU, and the process proceeds to step S9.

In step S9, each brake controller B / ECU calculates the hydraulic piston pressing force from the master cylinder pressure read in step S9, and proceeds to step S10. Here, the hydraulic piston pressing force F can be calculated from the following equation.
F = P × A
Here, P is the master cylinder pressure, and A is the piston pressure receiving area.

  In step S10, each brake controller B / ECU calculates the motor pressing force by subtracting the hydraulic piston pressing force calculated in step S9 from the thrust detected by the thrust sensors 10FL, 10FR, and proceeds to step S11.

  In step S11, each brake controller B / ECU determines whether the motor pressing force calculated in step S10 is greater than the hydraulic piston pressing force calculated in step S9. If YES, the process proceeds to step S12. If NO, the process proceeds to step S15.

  In step S12, the solenoid-in valve 104 is closed in each brake controller B / ECU, and the process proceeds to step S15.

  In step S13, in each brake controller B / ECU, the solenoid-in valve 104 is opened, and the process proceeds to step S14.

  In step S14, in each brake controller B / ECU, the shutoff valve 106 is closed and the process proceeds to return.

  In step S15, in each brake controller B / ECU, the shut-off valve 106 is opened, and the process proceeds to return.

Next, the operation will be described.
[Kickback prevention]
In the brake device of the first embodiment, the motor 5 is controlled such that the motor pressing force is greater than the hydraulic piston pressing force in order to increase the control accuracy of the motor 5. However, while the hydraulic piston pressing force rises without delay according to the depression speed of the brake pedal BP, at the initial stage of braking when the motor 5 starts rotating from the stopped state, the motor pressing is performed against the rising of the hydraulic piston pressing force. There is a delay in the rise of the force. This delay is caused by a delay in servo control of the motor 5 or the like.

  FIG. 18 is a diagram illustrating the relationship between the pedal operation speed of the brake pedal BP, the hydraulic piston pressing force, and the motor pressing force at the initial stage of braking (after 55 msec from the start of braking). As is apparent from FIG. 18, when the pedal operation speed exceeds a predetermined value (30 mm / s), the difference between the hydraulic piston pressing force and the motor pressing force increases as the pedal operation speed increases.

  For this reason, when the driver depresses the brake pedal BP quickly, the brake fluid pushed into the hydraulic pipe 102 by the rise of the master cylinder pressure before the pressing force of the motor 5 rises is the cylinder of the hydraulic piston 9. The brake fluid of the hydraulic piston 9 flows back into the master cylinder M / C with the generation of the motor pressing force, so that the brake pedal BP is pushed back, so-called kickback occurs, and the pedal feeling Adversely affect. FIG. 19 shows the time-series change of the pedal stroke when the operation speed of the brake pedal BP is 100 mm / s. In this example, as the motor pressing force rises at the end of the motor operation dead time, the pedal stroke decreases and kickback occurs.

  On the other hand, in the third embodiment, when it is determined in step S7 that the pedal stroke speed is higher than the solenoid-in valve closing threshold (30 mm / s), the solenoid-in valve 104 is closed in step S12. Thereby, the cylinder chamber 9a of the hydraulic piston 9 and the master cylinder M / C are shut off, and even if the piston 9b is pushed into the cylinder chamber 9a due to the rise of the motor pressing force, the master cylinder M / C. The brake fluid can be prevented from flowing back to the rear, and the occurrence of kickback of the brake pedal BP can be prevented.

Further, the closing operation of the solenoid-in valve 104 is continued until the pedal stroke becomes equal to or less than the control threshold value in step S2, that is, until the brake operation is completed. Can be prevented.
After the solenoid-in valve 104 is closed in step S12, the shut-off valve 106 is opened in the subsequent step S15. Therefore, the driver can make a pedal stroke by absorbing the brake fluid pressure into the stroke simulator SS. And

  Furthermore, in Example 3, when the pedal stroke speed is higher than the solenoid-in valve closing threshold (30 mm / s) in Step S7, the hydraulic piston pressing force and the motor pressing force are compared in Step S11. When the motor pressing force becomes larger than the hydraulic piston pressing force, the process proceeds from step S11 to step S12 to close the solenoid-in valve 104, but when the motor pressing force is less than the hydraulic piston pressing force, step S11 From step S15, the solenoid-in valve 104 is not closed.

  For example, if the solenoid-in valve 104 is closed only by comparing the operation speed of the brake pedal PB and the solenoid-in valve closing threshold, the pushing effect of the outer pad 7b by the hydraulic piston 9 is hindered, and the response at the initial stage of braking is deteriorated. For this reason, in the first embodiment, when the motor pressing force is equal to or less than the hydraulic piston pressing force, the solenoid-in valve 104 is kept open, thereby achieving both improvement in response at the initial stage of braking and prevention of kickback of the brake pedal BP. Can be planned.

Next, the effect will be described.
In addition to the effects (1) to (9) of the first embodiment, the disk brake of the third embodiment has the effects listed below.

  (11) The brake controller B / ECU closes the solenoid-in valve 104 when the pedal stroke speed is greater than the solenoid-in valve closing threshold, thus preventing kickback when the driver depresses the brake pedal BP early. it can.

  (12) Since the brake controller B / ECU maintains the closed state of the solenoid-in valve 104 until the driver's braking operation is completed, the occurrence of kickback during the braking operation can be reliably prevented.

  (13) Since the brake controller B / ECU closes the solenoid-in valve 104 when the motor pressing force is larger than the hydraulic piston pressing force, it is possible to improve both responsiveness at the beginning of braking and prevent kickback of the brake pedal BP. Can be planned.

  In the brake control process of the third embodiment, the brake device of the fourth embodiment reduces power consumption that accompanies the state in which the solenoid-in valve 104 is closed when the vehicle is stopped. Since other system configurations and the configuration of the electronically controlled disc brake are the same as those in the first embodiment, illustration and description are omitted.

[Power consumption reduction control processing]
FIG. 20 is a flowchart showing the flow of power consumption reduction control processing executed by the BBW controller BBB / ECU and each brake controller B / ECU of the fourth embodiment, and each step will be described below. This control process starts when the solenoid-in valve 104 is closed in step S12 of FIG. 16, and ends immediately when the driver's brake operation is completed. Further, this control process is sequentially performed on each side of the left and right wheels.

  In Step S21, the wheel speed detected by the wheel speed sensors 107FL, 107FR, 107RL, and 107RR is read in the BBW controller BBW / ECU, and the process proceeds to Step S22.

  In step S22, the BBW controller BBB / ECU determines whether all the wheel speeds read in step S21 are 0 km / h, that is, whether the vehicle is stopped. If YES, the process proceeds to step S23, and if NO, the process proceeds to return.

  In step S23, the counter is counted up in the BBW controller BBW / ECU, and the process proceeds to step S24.

  In step S24, in the BBW controller BBW / ECU, it is determined whether or not the counter is equal to or greater than a predetermined value. If YES, the process proceeds to step S25, and if NO, the process proceeds to step S21. Here, the predetermined value is a value corresponding to a predetermined time T (for example, 30 seconds). For example, as shown in FIG. 21, the predetermined time T may be determined from a continuous operable time with respect to the hydraulic pressure of the solenoid-in valve 104. As shown in FIG. 21, the larger the difference between the cylinder chamber 9a and the master cylinder pressure, the shorter the continuous operation possible time of the solenoid-in valve 104. Therefore, the predetermined time T needs to be set shorter accordingly.

  In step S25, the BBB controller ECU reads the stroke amount of the brake pedal BP from the pedal stroke sensor 108, and proceeds to step S26.

  In step S26, the BBB controller / ECU calculates the required braking force corresponding to the pedal stroke amount read in step S25, and the braking force target value of each wheel 100FL, 100FR, 100RL, 100RR is determined from the calculated required braking force. The calculated braking force target value is output to the brake controller B / ECU and the electric disc brakes 101RL and 101RR, and the process proceeds to step S27.

  In step S27, the master cylinder pressure detected by the pressure sensors 105FL and 105FR is read in the brake controller B / ECU, and the process proceeds to step S28.

  In step S28, the brake controller B / ECU calculates the motor pressing force from the master cylinder pressure read in step S27 and the thrust detected by the thrust sensors 10FL and 10FR, and the process proceeds to step S29.

In step S29, the brake controller B / ECU calculates the pressure in the hydraulic piston 9 with the solenoid-in valve 104 closed from the master cylinder pressure read in step S27 and the motor pressing force calculated in step S28. The process proceeds to step S30. Here, the pressure P in the hydraulic piston 9 can be calculated from the following equation.
P = F / A
F is the hydraulic piston pressing force, and A is the piston pressure receiving area.

  In step S30, the brake controller B / ECU calculates a motor pressing force such that the hydraulic pressure converted value of the motor pressing force is higher than the master cylinder pressure read in step S27 by a predetermined amount, and the process proceeds to step S31. Here, the predetermined amount is set to a value that does not bother the pedaling force fluctuation when the master cylinder pressure increases by the predetermined amount, that is, a value that does not feel to the person, for example, 2N or less.

  In step S31, in the brake controller B / ECU, when the motor pressing force of the electronically controlled disc brakes 1FL, 1FR is the value calculated in step S30, the motor pressing of the electric disc brakes 101RL, 101RR that maintains the required braking force constant The force (rear wheel motor pressing force) is calculated, and the process proceeds to step S32.

  In step S32, the BWB controller BBW / ECU increases the rear wheel motor pressing force by transmitting the rear wheel motor pressing force calculated by the brake controller B / ECU in step S31 to the electric disc brakes 101RL and 101RR. Migrate to

  In step S33, in the brake controller B / ECU, the motor pressing force is reduced so as to be the motor pressing force calculated in step S30, and the process proceeds to step S34.

  In step S34, the solenoid-in valve 104 is opened in the brake controller B / ECU, and the process proceeds to step S35.

  In step S35, the brake controller B / ECU reads the rotation angle (number of rotations) of the motor 5 detected by the rotation angle sensor 5c, and proceeds to step S36.

  In step S36, the brake controller B / ECU determines whether or not the motor rotational speed read in step S35 is zero, that is, whether or not the piston 9b is in a bottomed state. If YES, the process proceeds to step S37, and if NO, the process proceeds to step S37.

  In step S37, the solenoid-in valve 104 is opened in the brake controller B / ECU, and the process proceeds to step S27.

  In step S38, in the brake controller B / ECU, the motor pressing force is increased so as to achieve normal front and rear wheel braking force distribution (see FIG. 17), and the process proceeds to step S39.

  In step S39, the rear wheel motor pressing force is reduced in the BBW controller BBW / ECU so that the normal front / rear wheel braking force distribution is achieved, and the process proceeds to return.

Next, the operation will be described.
[Power consumption reduction]
In the third embodiment, in order to reduce power consumption, when the pedal stroke speed is higher than the solenoid-in valve closing threshold (30 mm / s), control for closing the solenoid-in valve 104FL is performed. However, since the solenoid-in valve 104 is a normally-open electromagnetic valve, it is necessary to continue supplying power to a solenoid (not shown) in order to maintain the closed state. Therefore, there is a problem of power consumption when the brake pedal BP is depressed for a long time when the vehicle is stopped.

  On the other hand, in Example 4, when it is determined that the vehicle is stopped in Step S22 and a predetermined time T (30 sec) has elapsed in Step S24, the solenoid-in valve 104 is opened in Step S34, thereby The power consumption of the in-valve 104 can be reduced. Further, since the size of the solenoid-in valve 104 is determined by the continuous operation time and the operation differential pressure, the solenoid-in valve 104 can be downsized by performing the power consumption reduction control of the fourth embodiment.

  Here, when the solenoid-in valve 104 is opened, the brake fluid sealed in the cylinder chamber 9a of the hydraulic piston 9 returns to the master cylinder, and the differential pressure between the brake fluid pressure in the cylinder chamber 9a and the master cylinder pressure is obtained. A corresponding pedal force fluctuation occurs, and if this pedal force fluctuation is large, the driver feels uncomfortable.

  Therefore, in Example 4, the motor pressing force is calculated in step S30 so that the hydraulic pressure converted value of the motor pressing force is 2N higher than the master cylinder pressure, and the motor pressing force calculated in step S33 is obtained. A series of processes for reducing the pressing force is repeated until it is determined in step S36 that the piston 9b is in the bottomed state (steps S27 to S37). As a result, the master cylinder pressure can be gradually increased (by 2N), so that the brake fluid can be gradually returned to the master cylinder M / C without notifying the driver of the pedaling force fluctuation.

  Next, as described above, when the motor pressing force of the electronically controlled disc brake is reduced in order to suppress the pedaling force fluctuation, the braking force of the applied wheel corresponding to the electronically controlled disc brake is reduced. There is a possibility that the total braking force according to the depression amount, that is, the braking force requested by the driver cannot be maintained, and the vehicle may move due to a slope or creep torque. Therefore, in the fourth embodiment, the motor pressing force of the electric disc brakes 101RL and 101RR is increased according to the amount of decrease in the motor pressing force in step S32 before the motor pressing force is decreased in step S33. The total braking force can be kept constant.

Next, the effect will be described.
In addition to the effects (1) to (9) of the first embodiment and the effects (11) to (13) of the third embodiment, the disk brake of the fourth embodiment has the following effects.

  (14) The brake controller B / ECU opens the solenoid-in valve 104 when the solenoid-in valve 104 is closed for a predetermined time T or more while the vehicle is stopped. It is possible to reduce the power consumption of the solenoid-in valve 104 when it is continuously stepped on and to reduce the size of the solenoid-in valve 104.

  (15) The brake controller B / ECU reduces the motor pressing force so that the brake fluid pressure returned to the master cylinder M / C is higher than the master cylinder pressure by a predetermined amount (for example, 2N). The brake fluid sealed in the cylinder chamber 9a of the hydraulic piston 9 can be gradually returned to the master cylinder M / C without noticing the treading force fluctuation.

  (16) Since the brake controller B / ECU increases the braking force of the left and right rear wheels 100RL and 100RR by the amount corresponding to the reduction of the braking force of the wheels due to the reduction of the motor pressing force, the total braking force of the vehicle can be kept constant.

(Other examples)
Although the best mode for carrying out the present invention has been described with reference to the respective embodiments based on the drawings, the specific configuration of the present invention is not limited to those shown in the respective embodiments. Any design changes that do not change the gist of the present invention are included in the present invention.

  For example, in the embodiment, the first pad is an outer pad and the second pad is an inner pad. However, the second pad may be provided on the outer side in the vehicle width direction and the first pad may be provided on the inner side in the vehicle width direction with the brake disc interposed therebetween. Good.

In the embodiment, an example in which the hydraulic pipe 102 communicating the master cylinder M / C and the cylinder chamber 9a of the hydraulic piston 9 is formed in the housing of the caliper 2 (22) is shown, but as shown in FIG. By providing the pipe 60 on the outside of the caliper 2, the labor for forming the pipe in the housing can be saved and man-hours can be reduced.
In the first and second embodiments, the solenoid-in valve is provided on the housing side. However, the solenoid-in valve may be provided on the vehicle body side.

1 is a system configuration diagram of a brake device to which an electronically controlled disc brake according to a first embodiment is applied. FIG. 2 is a front wheel side hydraulic circuit diagram of the brake device according to the first embodiment. 1 is a side cross-sectional view of an electronically controlled disc brake according to a first embodiment. It is a top view of the electronically controlled disc brake of Example 1. FIG. 1 is a front view of an electronically controlled disc brake according to a first embodiment. It is a figure which shows the latch mechanism of Example 1. FIG. It is a figure which shows the relationship between the hydraulic piston pressing force of Example 1, and a motor pressing force. 3 is a time chart illustrating a braking force generation operation of the first embodiment. It is a figure which shows the piston bottom effect | action of Example 1. FIG. 3 is a time chart illustrating a braking force generating operation during sudden braking according to the first embodiment. It is side surface sectional drawing of the electronically controlled disc brake of Example 2. FIG. 6 is a plan view of an electronically controlled disc brake according to Embodiment 2. FIG. It is a front view of the electronically controlled disc brake of Example 2. It is a rear view of the electronically controlled disc brake of Example 2. It is a front-wheel side hydraulic circuit diagram of the brake device of Example 3. It is a flowchart which shows the flow of the brake control processing which BBB controller / ECU of Example 3 and each brake controller B / ECU perform. It is a figure which shows distribution of the caliper pressing force of the front and rear wheels with respect to the total braking force. It is a figure which shows the relationship between the pedal operation speed of the brake pedal BP, the hydraulic piston pressing force, and the motor pressing force in the initial stage of braking (after 55 msec from the start of braking). It is a time chart of the pedal stroke when the operation speed of the brake pedal BP is 100 mm / s. It is a flowchart which shows the flow of the power consumption reduction control process which BBB controller BBW / ECU of Example 4 and each brake controller B / ECU perform. It is a setting map of the predetermined time T. It is side surface sectional drawing of the electronically controlled disc brake of another Example.

Explanation of symbols

BBW / ECU BBW controller (ABS control means)
BD brake disc
B / ECU brake controller (braking force control means)
M / C master cylinder (working pressure generating means)
1 Electronically controlled disc brake 2 Caliper 3 Main housing 4 End housing 5 Motor (electric motor)
6 Ball screw mechanism (motion conversion mechanism)
7a Inner pad (first pad)
7b Outer pad (second pad)
8 Bridge 9 Hydraulic piston (piston mechanism)
10 Thrust sensor 13 Latch mechanism (locking means)
102 Hydraulic piping (working pressure supply passage)
103 Hydraulic piping (communication path)
104 Solenoid in valve (flow control valve)
105 Pressure sensor
106 Shut-off valve

Claims (16)

A brake disc that rotates integrally with the wheel;
A first pad and a second pad arranged opposite to each other across the brake disc;
A caliper that supports the first pad and the second pad so as to be relatively displaceable in the wheel axis direction with respect to the vehicle body;
An operating pressure generating means for generating an operating pressure in accordance with the braking operation amount of the driver;
A piston mechanism that is provided on the first pad side of the caliper and presses the first pad against the brake disc according to the operating pressure;
An electric motor provided on the second pad side of the caliper;
A motion conversion mechanism that is provided on the second pad side of the caliper, converts a rotational force of the electric motor into a linear motion, and presses at least a second pad of the first pad and the second pad against the brake disc;
A disc brake comprising: The disc brake according to claim 1, wherein
Braking operation amount detection means for detecting the operation amount;
First braking force detection means for detecting a braking force generated by the pressing force of the piston mechanism;
Second braking force detection means for detecting a braking force generated by the pressing force of the motion conversion mechanism;
Target braking force calculation means for calculating a braking force target value of the wheel based on the braking operation amount;
A braking force obtained by adding the braking force detected by the first braking force detection means and the braking force detected by the second braking force detection means is a braking force calculated by the target braking force calculation means. A disc brake comprising braking force control means for controlling the electric motor so as to achieve a target value. The disc brake according to claim 2, wherein
The disc brake according to claim 1, wherein the braking force control means controls the electric motor so that a pressing force of the motion conversion mechanism is larger than a pressing force of the piston mechanism. The disc brake according to any one of claims 2 and 3, wherein an ABS control means for controlling a braking force in accordance with a locking tendency of the wheel;
A flow rate control valve provided on an operating pressure supply passage communicating the operating pressure generating means and the piston mechanism;
With
The disc brake characterized in that the braking force control means closes the flow rate control valve when the ABS is activated. The disc brake according to claim 4, wherein
A disc brake comprising a stroke simulator disposed on the operating pressure supply passage and configured to absorb the operating pressure generated by the operating pressure generating means during ABS operation. The disc brake according to claim 5,
A disc brake comprising a shut-off valve on a communication path communicating the working pressure supply path and the stroke simulator. In the disc brake according to any one of claims 2 to 6,
A flow rate control valve provided on an operating pressure supply passage communicating the operating pressure generating means and the piston mechanism;
An operation amount change speed detecting means for detecting a change speed of the braking operation amount of the driver;
With
The disc brake characterized in that the braking force control means closes the flow control valve when the rate of change of the braking operation amount is greater than a predetermined value. The disc brake according to claim 7,
The disc brake according to claim 1, wherein the braking force control means maintains the closed state of the flow rate control valve until a driver's braking operation is completed. In the disc brake according to claim 7 or 8,
The disc brake according to claim 1, wherein the braking force control means closes the flow control valve when a pressing force of the motion conversion mechanism is larger than a pressing force of the piston mechanism. The disc brake according to any one of claims 7 to 9,
The disc brake according to claim 1, wherein the braking force control means opens the flow rate control valve when the state in which the flow rate control valve is closed for a predetermined time or more while the vehicle is stopped. The disc brake according to claim 10, wherein
The braking force control means reduces the pressing force of the motion converting mechanism so that the pressure fluctuation on the operating pressure generating means side of the flow rate control valve in the operating pressure supply passage is a predetermined amount or less. Disc brake. The disc brake according to claim 10 or 11,
The disc brake according to claim 1, wherein the braking force control means increases the braking force of the other wheel by the amount corresponding to the decrease in the braking force of the wheel due to the decrease in the pressing force of the motion conversion mechanism. The disc brake according to any one of claims 1 to 12,
A locking means capable of restricting displacement of the motion conversion mechanism in a direction of separating the second pad from the brake disk by engagement with the motion conversion mechanism;
The disc brake characterized in that the braking force control means engages the locking means with the motion conversion mechanism when the output of the motor is reduced. The disc brake according to any one of claims 1 to 13, wherein
The caliper is integrally provided with a base portion that houses the electric motor and the motion conversion mechanism and a first pad support portion that supports the first pad, and is supported so as to be relatively displaceable in the wheel axis direction with respect to the vehicle body side member. Floating caliper
The motion conversion mechanism is housed in the base, is fixed to the base in a wheel axis direction and is fixed in position, and rotates together with a rotating shaft of the electric motor, supports the second pad, and supports the caliper. A disc brake comprising: a rectilinear member relatively displaceable in a wheel axis direction; and a screw transmission mechanism that converts a rotational motion of the rotating member into a rectilinear motion and transmits the linear motion to the rectilinear member. The disc brake according to claim 14, wherein
A pressure detecting means for detecting pressure acting in the wheel axis direction is provided between the rotating member and the base in the wheel axis direction,
The braking force control means controls the electric motor so that the pressure detected by the thrust detection means becomes a value corresponding to a braking force target value of the wheel based on the braking operation amount. Disc brake. The disc brake according to any one of claims 1 to 13, wherein
The caliper accommodates the electric motor and the motion conversion mechanism and is fixed to the vehicle body side member in a position-invariant position in the wheel axis direction, and supports the first pad and can be displaced relative to the base part in the wheel axis direction. A fixed caliper having a first pad support portion and a second pad support portion that supports the second pad and is relatively displaceable in the wheel axis direction with respect to the base portion and the first pad support portion, respectively.
The motion conversion mechanism includes: a rotating member that rotates integrally with a rotating shaft of the electric motor; a first rectilinear member that is provided integrally with the first pad support portion and is relatively displaceable in the wheel axis direction with respect to the base portion; A second rectilinear member provided integrally with the second pad support portion and capable of relative displacement in the wheel axis direction with respect to the base portion, and a first that converts the rotational motion of the rotating member into rectilinear motion and transmits it to the first rectilinear member A disk brake, comprising: a screw transmission mechanism; and a second screw transmission mechanism that converts a rotational motion of the rotating member into a linear motion and transmits the linear motion to the second linear member.

Images