JP4526657B2 - Electric brake device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric brake device suitable for use in a vehicle.
[0002]
[Prior art]
As an electric brake device, for example, one disclosed in Japanese Patent Application Laid-Open No. 2000-46082 is known.
The electric brake device disclosed in this publication includes a pair of brake pads disposed on both sides of a disk, a piston provided in a caliper body so as to face at least one of the pair of brake pads, and a caliper body. A motor provided to rotate the rotor, a conversion mechanism for converting the rotational motion of the rotor rotated by the motor into a linear motion and transmitting it to the piston, a position detection means for detecting the stroke position of the piston, and position detection Control means for controlling the motor based on the detection result of the means, and has a basic configuration in which a braking force is generated by pressing a brake pad against a disk by a linear motion by a piston, It is detected by a traveling state detection means such as an accelerator pedal pressure sensor that detects whether or not the accelerator is being depressed. If it is determined from the detection result that the driver will perform the brake operation soon, and the driver determines that the brake operation is about to be performed, the clearance between the brake pad and the disc is reduced before the brake operation is performed. Narrowing in advance, thereby improving responsiveness at the initial stage of braking.
[0003]
Another electric brake device disclosed in Japanese Patent Laid-Open No. 03-45462 is also known.
The electric brake device disclosed in this publication detects a full brake state, and a position returned by a predetermined amount from the position of the brake pad at that time is defined as a brake pad position when a brake operation unit such as a brake pedal is released. By arranging the brake pads on the brake pads, it is intended that the brake pad position is always appropriate when the brake operation unit is opened.
[0004]
[Problems to be solved by the invention]
Among the conventional electric brake devices described above, the former one (disclosed in Japanese Patent Application Laid-Open No. 2000-46082) improves the responsiveness at the initial stage of the brake on the assumption that the driver performs a normal brake operation. Therefore, the driver does not improve the responsiveness at the initial stage of braking such as an automatic braking mechanism or a vehicle stabilization mechanism in which the braking force is automatically exerted without performing the braking operation. The latter (disclosed in Japanese Patent Application Laid-Open No. 03-45462) is intended to be an appropriate brake pad position, but does not improve the initial response of the brake.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric brake device that can prevent pebbles and the like from entering between a brake pad and a disk when traveling on a rough road. There is .
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is provided in the caliper body, a pair of brake pads disposed on both sides of the disc, a piston provided in the caliper body so as to face at least one of the pair of brake pads, A motor for rotating the rotor, a conversion mechanism for converting the rotational motion of the rotor rotated by the motor into a linear motion and transmitting it to the piston, a position detection means for detecting the stroke position of the piston, and the position detection means; Control means for controlling the motor based on the detection signal of the motor, and separately from the braking operation by the driver, based on the detection signal from the sensor for detecting the state of the vehicle, the piston by the motor and the conversion mechanism section. In an electric brake device that generates braking force on wheels by causing the brake pad to press against the disc by linearly moving the brake Has a rough road condition detecting means for detecting whether or not the state of the road rough road during vehicle travel, the control means, the disc and the brake pad in accordance with a detection result of the rough road condition detection means The motor is controlled so as to narrow the clearance .
[0010]
According to the present invention, the motor is controlled by the control means so as to narrow the clearance between the brake pad and the disc in accordance with the detection result of the rough road condition detection means.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of an electric brake device of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the electric brake device 10 is slidably supported in a state in which the carrier 12 is fixed to a non-rotating portion of the vehicle and the carrier 12 is disposed on both sides in the axial direction of the disk 13. A pair of inner pad 14 and outer pad 15, and inner pad 14 and outer pad 15 supported by carrier 12 so as to be slidable in the axial direction of disk 13 at two sliding guide portions (not shown) are held from both sides. It is mainly composed of possible calipers 17.
[0012]
The carrier 12 is shown in two places for connecting the first connecting portion 22a and the second connecting portion 22b arranged substantially parallel to each other and the respective ends of the first connecting portion 22a and the second connecting portion 22b. And a supporting portion.
The carrier 12 is fixed to the vehicle body in a state where the carrier 12 is disposed with respect to the disk 13 so that the support portions are positioned at both ends in the circumferential direction of the disk 13. In addition, a sliding guide part is provided in each support part.
[0013]
A pair of pad guides (not shown) are provided at positions inside the support portions of the carrier 12 so as to face each other. With these pad guides, the inner pad 14 and the outer pad 15 are arranged along the axial direction of the disk 13. It is supported at each end position so as to be slidable. In this supported state, the inner pad 14 and the outer pad 15 are restricted from rotating around an axis parallel to the axis of the disk 13.
[0014]
The caliper 17 includes a housing 28 having a substantially cylindrical tubular member 25 and a tip member 27 fixed to one side of the tubular member 25.
[0015]
The housing 28 is provided with a motor 33 and a ball ramp mechanism (conversion mechanism unit) 34 that converts the rotational motion of the motor 33 into linear motion.
The motor 33 includes a stator 35 attached to the inner peripheral portion of the cylindrical member 25, and a rotor 36 that is positioned inside the stator 35 and rotates when electric power is supplied to the stator 35. .
[0016]
The ball ramp mechanism 34 is fixed to the inner peripheral portion of the rotor 36 and is rotatable, and the ball ramp mechanism 34 is provided to face the movable ramp member 37A and is fixed to the cylindrical portion 51 with a pin. The fixed lamp member 37B and a plurality of balls 38 interposed between the movable lamp member 37A and the fixed lamp member 37B.
[0017]
Each ball 38 is slidably disposed in a plurality of ball grooves formed in an arc shape along the circumferential direction on the opposing surfaces of both the lamp members 37A and 37B, and the relative rotation of both the lamp members 37A and 37B. Thus, the plurality of balls 38 roll in the ball groove, and the axial distance between the lamp members 37A and 37B changes according to the relative rotation.
[0018]
The tip member 27 extends from the one side in the radial direction of the cylindrical portion 51 to the opposite side to the cylindrical member 25 and is fixed to the cylindrical member 25 so as to be substantially coaxial. And a claw portion 53 extending from the front end side of the disc path portion 52 so as to face the tube portion 51.
[0019]
The above-described ball 38 is fitted to the inner peripheral portion of the cylindrical portion 51 of the tip member 27. The position of the movable lamp 37A in the axial direction is detected in the vicinity of the ball 38, and the piston portion is based on the detected position. A position detector (position detecting means) 57 for detecting 40 stroke positions is attached.
[0020]
Here, with the caliper 17 supported by the carrier 12, the motor 33 and the ball ramp mechanism 34 have their respective axes parallel to the axis of the disk 13, and are arranged on the inner peripheral side of the ball ramp mechanism 34. The piston portion 40 is disposed so as to be able to come into contact with the disc 13 of the inner pad 14 so as to be able to contact the opposite side, and the tip member 27 extends so that the disc path portion 52 straddles the outer peripheral portion of the disc 13 and the claw portion 53 The outer pad 15 is disposed so as to face the disk 13 so as to be in contact with the opposite side.
With the configuration described above, the rotational motion of the rotor 36 is converted into linear motion by the ball ramp mechanism 34 and transmitted to the piston portion 40. By this linear motion, the disc 13 is pressed by the inner pad 14 and the outer pad 15 through the piston portion 40 and the claw portion 53 to generate a braking force.
[0021]
Further, a dust boot 59 is provided between the left end of the piston portion 40 in FIG. 1 and the cover 28 covering the outside of the ball 38 to prevent dust from entering the fitting portion of the ball ramp mechanism 34. Yes.
[0022]
The electric brake device 10 having the above-described configuration is provided for each of the front, rear, left, and right wheels of the vehicle, and the motors 33 and position detectors 57 of all the electric brake devices 10 are connected to a controller (control means) 60. ing. Here, each motor 33 is connected to a motor driver (not shown) provided in the controller 60 for driving the motor 33.
The controller 60 also includes a steering sensor 61 that detects a steering angle, a yaw rate sensor 62 that detects a swinging state of the vehicle in the left-right direction, and an inter-vehicle distance sensor that measures an inter-vehicle distance between the vehicle and the preceding vehicle. 63, and an acceleration sensor 64 for detecting the acceleration in the vertical direction of the vehicle or wheel are connected to each other.
[0023]
Next, the operation of the electric brake device according to this embodiment will be described with reference to the flowchart shown in FIG.
In FIG. 2, when an ignition switch (not shown) is turned on, the controller 60 proceeds to step S1, and determines whether or not the brake pedal is depressed from an output signal of a brake pedal switch (not shown).
[0024]
If the driver now depresses the brake pedal, an ON signal is output from the brake pedal switch. Thereby, the controller 60 sets the determination result in step S1 to “YES”, and proceeds to step S2. In step S2, the controller 60 controls the motor 33 for each electric brake device 10 so as to generate a braking force on each wheel according to the operation amount of the brake pedal detected by an operation amount detection sensor (not shown). After performing feedback control based on the rotational position data of the position detector 57, the process proceeds to step S10.
[0025]
When generating the braking force, the controller 60 causes the motor 33 to rotate the movable lamp member 37A in the forward direction. Then, the piston portion 40 is moved in the direction of the disk 13 by the fixed ramp member 37B and the ball 38 to bring the inner pad 14 into contact with the disk 13, while the caliper 17 is moved with respect to the carrier 12 by the reaction force, and the claw portion 53 is moved. Thus, the inner pad 14 and the outer pad 15 are finally pressed in the direction of the disk 13 by the piston portion 40 and the claw portion 53, and the inner pad 14 and the outer pad 15 are finally moved. Contacts the disk 13 to generate a braking force.
[0026]
On the other hand, when the controller 60 releases the braking force from this state, the motor 33 rotates the movable lamp member 37A in the reverse direction opposite to the normal direction. Then, the piston portion 40 is moved away from the disk 13 by the fixed ramp member 37B and the ball 38. As a result, the inner pad 14 and the outer pad 15 are separated from the disk 13 to release the braking force.
[0027]
If it is assumed that the brake pedal is not stepped on now, the controller 60 sets “NO” as the determination result of step S1, and proceeds to step S3. In step S3, the controller 60 determines whether or not the vehicle is running from an output signal of a rotation sensor (not shown). The rotation sensor is a sensor that detects the rotation of the disk 13.
[0028]
If it is assumed that the vehicle is now stopped, the controller 60 sets “NO” as the determination result of the step S3 from the output signal of the rotation sensor, and proceeds to the step S4. In step S4, the controller 60 controls the motor current supplied to the motor 33 while receiving a feedback signal from the position detector 57 so that the clearance between the disk 13 and the inner pad 14 (outer pad 15) becomes zero. The process proceeds to step S10. Through the above-described operation, the inner pad 14 and the outer pad 15 are moved, and as a result, the clearance between the disk 13 and the inner pad 14 (outer pad 15) is made zero.
[0029]
Therefore, in this case, since the clearance is zero, it is possible to prevent the occurrence of a problem that water enters between the disk 13 and the inner pad 14 (outer pad 15) and freezes.
[0030]
On the other hand, if it is assumed that the vehicle is traveling, the controller 60 sets “YES” as the determination result of step S3 from the output signal of the rotation sensor, and proceeds to step S5. In step S5, the controller 60 predicts in advance whether or not a braking operation is likely to be required.
[0031]
For example, in the case of a normal brake operation, whether or not an accelerator pedal (not shown) is depressed is predicted from an output signal of an accelerator pedal switch (not shown). That is, when the accelerator pedal is released, it is predicted that a braking operation is likely to be required.
[0032]
In the case of control by the vehicle stabilization mechanism , a determination is made based on the detection signal from the steering sensor 61, the detection signal from the yaw rate sensor 62, or the detection signals from both sensors 61 and 62, and detection from these sensors. When the signal exceeds a threshold value set under a condition looser than the vehicle stabilization mechanism operating condition described later, it is predicted that the operation of the vehicle stabilization mechanism is likely to be necessary.
[0033]
In the case of control by the automatic brake mechanism, the inter-vehicle distance from the preceding vehicle is measured by the detection signal from the inter-vehicle distance sensor 63 provided in the vehicle, and the detection signal from the inter-vehicle distance sensor 63 is determined by the automatic brake mechanism operating condition. When a threshold set under a loose condition is exceeded (actually when the distance between vehicles becomes shorter than a preset value), or a braking operation warning signal is issued from a controller of another control system Sometimes it is predicted that the automatic brake mechanism will likely need to be operated.
[0034]
If it is predicted in step S5 that a braking operation is likely to be required, the determination result in step S5 is “YES” and the process proceeds to step S6. In step S6, the controller 60 receives the feedback signal from the position detector 57 so that the clearance between the disk 13 and the inner pad 14 (outer pad 15) is a predetermined minute gap as shown in FIG. After controlling the motor current supplied to the motor 33, the process proceeds to step S8. Through the above-described operation, the inner pad 14 and the outer pad 15 are moved, and as a result, the clearance between the disk 13 and the inner pad 14 (outer pad 15) is a minute gap.
[0035]
If it is not predicted in step S5 that a braking operation is likely to be required, the determination result in step S5 is “NO” and the process proceeds to step S7. In step S7, the controller 60 supplies the motor 33 while receiving a feedback signal from the position detector 57 so that the clearance between the disk 13 and the inner pad 14 (outer pad 15) is a specified gap as shown in FIG. After the motor current to be controlled is controlled, the process proceeds to step S8. Here, step S5 constitutes “braking prediction means”, “ vehicle stability mechanism operation prediction means”, and “automatic brake mechanism prediction means” in the claims.
[0036]
In step S8, it is determined by, for example, the acceleration sensor 64 whether or not the road on which the vehicle is traveling is in a bad road state. If it is determined that the road is in a rough road, the determination result in step S8 is “YES”, and the process proceeds to step S9.
In step S9, the controller 60 receives the feedback signal from the position detector 57 so that the clearance between the disk 13 and the inner pad 14 (outer pad 15) becomes a predetermined minute gap as shown in FIG. The motor current supplied to the motor 33 is controlled. Thereby, since the clearance between the disk 13 and the inner pad 14 (outer pad 15) becomes a minute gap, it is possible to prevent pebbles and the like from entering between the disk 13, the inner pad 14, and the outer pad 15. Thereafter, the process proceeds to step S10.
If it is determined that the road is not in a rough road, the determination result in step S8 is “NO” and the process proceeds to step S10.
[0037]
In step S10, it is determined whether or not control by the vehicle stabilization mechanism is necessary. That is, whether the detection signal from the steering sensor 61, the detection signal from the yaw rate sensor 62, or the detection signals from both the sensors 61 and 62 exceeds a threshold value set in advance as a control operation condition of the vehicle stabilization mechanism . to decide. If it is determined that control by the vehicle stabilization mechanism is necessary, the determination result in step S10 is “YES” and the process proceeds to step S11. In step S11, control by a predetermined vehicle stabilization mechanism is performed, and a required braking force is applied to each wheel to ensure the stability of the vehicle during cornering. After control by the vehicle stabilization mechanism is performed, the process proceeds to step S12.
[0038]
Here, the inner pad 14 (outer pad 15), as described above, since the distance between the disc 13 is moved in advance to be a small gap before the control by the vehicle stability mechanism is started, according to the vehicle stability mechanism When the control is started, the inner pad 14 (outer pad 15) contacts the disc 13 in a very short time, so that the initial brake response characteristics are excellent.
[0039]
On the other hand, if it is determined that control by the vehicle stabilization mechanism is not necessary, the determination result in step S10 is “NO”, and the process proceeds to step S12.
[0040]
In step S12, it is determined whether or not control by the automatic brake mechanism is necessary. That is, the inter-vehicle distance is measured based on the detection signal from the inter-vehicle distance sensor 63, and whether the detection signal from the inter-vehicle distance sensor 63 exceeds a threshold value set in advance as a control operation condition of the automatic brake mechanism, Alternatively, it is determined whether a braking signal is issued from a controller of another control system.
If it is determined that control by the automatic brake mechanism is necessary, the determination result in step S12 is “NO”, and the process proceeds to step S13. In step S13, predetermined automatic brake control is performed, and thereby, for example, the inter-vehicle distance from the vehicle ahead is properly maintained.
If it is determined that the automatic brake control is not necessary, the determination result of step S12 is “NO”, and the process returns to step S1.
Thereafter, the above-described operation is repeated.
[0041]
Although the electric brake device according to the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this one embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, in the electric brake device according to the above-described embodiment, the braking operation is controlled by the vehicle stabilization mechanism and control by the automatic brake mechanism, but can be applied to other braking operations. Further, although the braking operation necessity detecting means is the steering sensor 61, the yaw rate sensor 62, the inter-vehicle distance sensor 63, etc., the control may be performed based on detection signals of other sensors or commands from the outside.
[0042]
【The invention's effect】
As described above, according to the invention of claim 1, the pad clearance can be reduced when traveling on a rough road, and pebbles and the like can be prevented from entering between the brake pad and the disk when traveling on a rough road. The braking performance can be stabilized.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a configuration of an electric brake device according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating the operation of the electric brake device according to the same embodiment.
FIG. 3 is a time chart showing brake pad positions in the electric brake device according to the same embodiment.
[Explanation of symbols]
13 Disc 14 Inner pad 15 Outer pad 33 Motor 34 Ball ramp mechanism (conversion mechanism part)
40 piston part 57 position detector (position detecting means)
60 controller (control means)
61 Steering sensor 62 Yaw rate sensor 63 Inter-vehicle distance sensor 64 Acceleration sensor

Claims (1)

A pair of brake pads arranged on both sides of the disc;
A piston provided in the caliper body so as to face at least one of the pair of brake pads;
A motor provided in the caliper main body, for rotating the rotor;
A conversion mechanism that converts the rotational motion of the rotor rotated by the motor into linear motion and transmits the linear motion to the piston;
Position detecting means for detecting a stroke position of the piston;
Control means for controlling the motor based on a detection signal of the position detection means, and separately from the braking operation by the driver, the motor and the conversion mechanism based on a detection signal from a sensor for detecting the state of the vehicle. In the electric brake device for generating a braking force on the wheel by causing the piston to linearly move by the portion and pressing the brake pad against the disc,
Having bad road condition detecting means for detecting whether or not the road on which the vehicle is running is in a bad road condition;
The electric brake device characterized in that the control means controls the motor so as to narrow a clearance between the brake pad and the disc in accordance with a detection result of the rough road condition detection means.

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