JP2002213507A - Electric brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric brake device capable of preventing brake dragging phenomenon from occurring in addition to holding proper brake response. SOLUTION: This electric brake device has an electrically-driven means for pressing and separating a brake friction material supported on the vehicle side relative to a brake rotator, an operating condition detecting means for detecting the operating condition of the electrically-driven means, a brake command generating means for determining a brake command value in response to the quantity of braking operation, a brake control means for controlling the driven quantity of the electrically-driven means in order to make the operating condition agree with the brake command value, and a contact detecting means for detecting if the brake friction material is in contact with the brake rotator when applying no brake, It also has a contact preventing means to drive the electrically-driven means so as to have a direction to separate the brake friction material from the brake rotator by a prescribed quantity when the contact detecting means detects that the brake friction material is in contact with the brake rotator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric brake device used for braking a vehicle, and more particularly, to an electric brake device between a brake rotating body (rotor) and a brake friction material (pad) during the entire running process of the vehicle where braking is repeated. The present invention relates to an electric brake device that can advantageously suppress the occurrence of a brake drag phenomenon and a brake judder phenomenon.

[0002]

2. Description of the Related Art In recent years, various electric brake devices have been proposed in order to solve many problems of a hydraulic drive brake device. For example, in Japanese Patent Application Laid-Open No. Hei 9-137841, in the non-braking state, the clearance between the brake rotating body and the friction material is always kept constant, the braking operation is ensured, the intelligent operation is supported, and the compactness is achieved. Aiming to provide a possible electric brake device, an electric actuator is used when the thrust from the pad to the rotor becomes zero when braking is released, using an electric actuator that moves the brake friction material (pad) forward and backward with respect to the brake rotating body (rotor) The displacement of the pad is defined as the starting point of contact between the pad and the rotor, and the electric actuator is actuated in a direction in which the pad and the rotor are separated by a predetermined amount from this origin, thereby securing clearance between the pad and the rotor. An electric brake device for preventing so-called brake dragging has been proposed.

[0003]

However, in the electric brake device proposed in the above publication, the clearance between the pad and the rotor is controlled immediately after the braking is completed. And the pad may come into contact with the pad.

[0004] Therefore, the invention described in claims 1 to 9 of the present invention is to provide an electric brake device that solves the above-mentioned problems, and specifically, a brake is applied to a brake rotating body when the vehicle is not braking. Separates the friction material under the appropriate clearance, thereby suppressing the occurrence of the brake drag phenomenon,
In addition, another object of the present invention is to provide an electric brake device capable of maintaining appropriate brake responsiveness.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a brake friction member which is supported on a vehicle body side of a vehicle is pressed against a brake rotating body which rotates together with wheels. An electric means for separating, an operation state detecting means for detecting an operation state of the electric means, a brake command generation means for determining a brake command value according to a brake operation amount of a driver, and the operation state to the brake command value. Brake control means for controlling the amount of drive of the electric means for matching, and contact detection means for detecting contact between the brake friction material and the brake rotator when the vehicle is not braking, the contact detection means comprising: A contact preventing means for driving the electric means in a direction to separate the brake friction material by a predetermined amount from the brake rotating body when detecting contact of the material with the brake rotating body; Preparative an electric braking apparatus according to claim.

According to the first aspect of the present invention, while the brake rotor having undergone thermal deformation during braking is cooled after the braking is released, the amount of thermal deformation is reduced, and while the brake rotor returns to the original shape, the contact detecting means is provided. Detects the contact between the brake rotator and the brake friction material, the contact prevention means drives the electric means in a direction to separate the brake friction material from the brake rotator by a predetermined amount, so that the thermally deformed brake rotator and the brake It is possible to prevent the occurrence of a sliding phenomenon with the friction material.
In addition, by appropriately setting the amount of separation of the brake friction material from the brake rotating body, excellent brake responsiveness can be exhibited.

[0007] The present invention described in claim 1 relates to claim 2.
As described above, the contact detecting means has a configuration for detecting the contact of the brake friction material with the brake rotating body based on the detection result of the operating state detecting means. According to the invention described, as in the invention described in claim 3, the contact detecting means transmits the contact of the brake friction material with the brake rotating body to the operating state detecting means of the electric means, and receives the transmission to operate. The state detecting means has a configuration for instructing driving of the electric means.

According to the second and third aspects of the present invention, the contact between the brake friction material and the brake rotating body is detected by the operating state detecting means, so that a special sensor is not required.
It is possible to reliably detect the contact between the two, and in addition, it is possible to simplify the device and reduce the cost.

According to the first to third aspects of the present invention, as in the fourth aspect of the present invention, the operating state detecting means detects any one of a rotational angular displacement and an axial displacement of the electric means. And a current detecting means for detecting an operating current of the electric means.

According to the fourth aspect of the invention, since the displacement of the motor and the current flowing through the motor are detected as the operating state of the motor, a stable operation signal is not affected by external noise. And the drive control of the electric means based on the detection of the contact between the brake rotating body and the brake friction material can be reliably performed.

Further, according to the invention described in claim 1, as in the invention described in claim 5, the contact preventing means includes:
A thermal deformation amount estimating means for estimating a thermal deformation amount of the brake rotator, wherein the contact preventing means removes a predetermined amount of the brake friction material from the brake rotator according to the thermal deformation amount of the brake rotator estimated by the means. It has the function of separating only by

According to the fifth aspect of the present invention, when the contact between the brake rotating body and the brake friction material is detected, the amount of thermal deformation of the brake rotating body that has undergone thermal deformation is estimated, and the braking is performed based on the estimated value. Since the amount of separation of the brake friction material from the rotating body is determined, the sliding phenomenon between the brake rotating body and the brake friction material that has undergone thermal deformation can be more reliably prevented.

[0013] The invention described in claim 5 relates to claim 6.
As described above, the thermal deformation estimating means includes a vehicle speed detecting means for detecting a vehicle speed, and an outside air temperature detecting means for detecting an outside air temperature around the vehicle, and a braking detected by the vehicle speed detecting means. Based on the vehicle speed immediately before the start, the vehicle speed at the time of completion of the braking, the vehicle speed after the completion of the braking, and the outside air temperature at the time of the braking detected by the outside air temperature detecting means, the thermal deformation estimating means detects the heat of the brake rotor. It has a function to estimate the amount of deformation.

According to the sixth aspect of the present invention, stable elements which are not affected by external noise, such as the vehicle speed before and after braking and the outside air temperature of the vehicle, are detected and based on the detected elements. Since the amount of thermal deformation of the brake rotating body is estimated, a highly reliable estimated value can be obtained.

Here, a certain relationship is established between the amount of thermal deformation of the brake rotor and the temperature. The temperature of the brake rotator is determined by the difference between the energy applied to the brake rotator due to braking and the energy released from the brake rotator due to heat release after braking. The energy applied to the brake rotator by braking can be calculated from the kinetic energy lost by the vehicle based on the vehicle speed immediately before the start of braking and the vehicle speed at the time of completion of braking. Further, the heat radiation from the brake rotating body after the braking is completed is determined by the heat transfer coefficient of the outside air around the brake rotating body and the outside air temperature, and the heat transfer rate is determined by the vehicle speed. That is, the energy released from the brake rotator can be calculated based on the vehicle speed and the outside air temperature after the braking is completed. This makes it possible to calculate the temperature of the brake rotating body and estimate the amount of thermal deformation from this temperature with high accuracy.

According to the invention described in claim 1 or 5, as in the invention described in claim 7, the contact preventing means has a lateral acceleration detecting device for detecting a lateral acceleration generated in the vehicle. When the contact detecting means detects the contact between the brake friction material and the brake rotator during braking, the contact preventing means removes the brake friction material from the brake rotator when the lateral acceleration detected by the lateral acceleration detecting device is equal to or greater than a predetermined value. It has a function of prohibiting the driving of the electric means for separating by a predetermined amount.

According to the invention described in claim 7, when the lateral acceleration acts on the vehicle in a turning operation or the like, the brake rotator falls down, and when the electric means moves in the axial direction, the lateral acceleration is greater than a predetermined value. Is the vehicle behavior in a short time,
Even if the brake rotator contacts the brake friction material, the drive of the electric means that separates the brake friction material by a predetermined amount is prohibited, so that the distance between the brake rotator and the brake friction material is not increased so that it is appropriate. Value, the rise time of the braking force at the next braking can be shortened, and the brake responsiveness can be maintained.

On the other hand, apart from the invention described in claim 7, the invention described in claim 1 or 5 relates to the invention described in claim 8
As described above, the contact preventing means has a lateral acceleration detecting device for detecting a lateral acceleration generated in the vehicle, and the contact detecting means detects a contact between the brake friction material and the brake rotating body during non-braking. When the contact prevention means, when the lateral acceleration detected by the lateral acceleration detecting device is equal to or more than a predetermined value, the electric friction means is driven to drive the brake friction material from the brake rotating body,
It has a function of separating by an amount determined based on the detected lateral acceleration, and in the invention according to the eighth aspect, as in the ninth aspect, the contact preventing means includes:
When the detected lateral acceleration is restored to a value less than the predetermined value, the electric motor is driven in the opposite direction to restore the clearance between the brake rotating body and the brake friction material.

According to the eighth and ninth aspects of the invention, a lateral acceleration of a predetermined value or more acts on the vehicle during a turning operation or the like.
When the brake rotator falls down and the electric means moves in the axial direction and the brake rotator contacts the brake friction material, the electric means is driven to separate the brake friction material from the brake rotator by an amount determined based on the lateral acceleration. By this, the distance between the brake rotating body and the brake friction material during turning is always maintained at an appropriate value to prevent the sliding behavior,
Excellent brake responsiveness can be maintained at the same time.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of the present invention will be described based on the examples shown in FIGS. 1 and 2, and the second embodiment will be described based on the examples shown in FIGS. 3 will be described based on the examples shown in FIGS. First, in one embodiment, FIG. 1 is a schematic diagram of an entire configuration showing a cross section of a main part of an electric brake device of the present invention, and FIG. 2 is a flowchart for explaining the operation of the electric brake device shown in FIG. It is.

In FIG. 1, an electric brake device 1 includes a brake rotor 2 that rotates with wheels (not shown), a brake rotor (hereinafter referred to as a rotor) 2 in the illustrated example, and brake friction supported on a vehicle body (not shown). The material 3 includes a brake pad (hereinafter referred to as a pad) 3 in the illustrated example, and an electric means 4 for pressing the pad 3 against the rotor 2 and separating the pad 3 from the rotor 2. The pad 3 has a pair of inner pads 3-1 and outer pads 3-2 for pressing the rotor 2 from both sides.

The illustrated electric means 4 includes a motor 6 mounted and fixed inside an electric caliper 5, a male screw 8 provided at the tip of a rotary shaft 7 of the motor 6, and a ball screw screwed to the male screw 8. And a nut 9. The nut 9 is fixed to a piston 12 having a guide member 11 slidably fitted in a groove 10 in the direction of the rotating shaft 7 provided on the inner surface side of the caliper 5.
The piston 12 is movable in the axial direction of the rotary shaft 7 via the nut 9 by the guide member 10 and the rotary shaft 7.
Restricts the turning in the rotation direction of.

The inner pad 3-1 is fixed to the tip of the piston 12, and the outer pad 3-2 is fixed to the inside of the caliper 5 at a position facing the pad 3-1 which sandwiches the rotor 2. When the electric brake device 1 is not operated, the pair of pads 3-1 and 3-2 are positioned with a predetermined clearance c between the pads 3-1 and 3-2.

When the electric brake device 1 is operated, the motor 6 of the electric means 4 is operated, the external thread 8 of the ball screw for converting the rotational motion into a linear motion is rotated (forward rotation), and the nut 9 is moved together with the piston 12 into the motor. 6 in the direction of the axis, thereby pressing the pad 3-1 against the inner surface of the rotor 2,
The caliper 5 is moved in a direction opposite to the above moving direction by a reaction force from the rotor 2 due to this pressing, and the pad 3-2 is pressed against the outer surface of the rotor 2 to generate a braking force. To release the brake, rotate the male screw 8 in the reverse direction and move the pad 3-1 and 3-2 in the reverse direction.
Is separated from the rotor 2.

The electric brake device 1 includes a brake pedal 14
A brake command value generating means 15 connected to the
Has a pedaling force sensor 16 for detecting a pedaling force as a driver's operation amount of the brake pedal 14 and a stroke sensor 17 for detecting a pedaling amount.These sensors 16 and 17 generate a brake command value according to the brake operation amount. The command value is transmitted to the brake control means 18 as a signal. Brake control means
18 controls the power supply unit 19 so that the brake command value and the operation state of the electric means 4, here the rotation angle of the motor 6, have a predetermined relationship, and supplies the output power from the power supply unit 19 to the motor 6. The motor 6 is driven to rotate.

That is, the electric brake device 1 has operating state detecting means for detecting the operating state of the electric means 4, and the means in the illustrated example is a rotation angle sensor 20 attached to the rotating shaft of the motor 6, and the brake control Means 18 and rotation angle sensor 20
And are connected by a circuit. The brake control means 18 controls the pad 3
-1, 3-2 are pressed and the output of the rotation angle sensor 20 at the time of starting contact with the rotor 2 is used as a reference value. The braking force is controlled by controlling the output of the power supply unit 19 so that the detected value of the rotation angle coincides with the detected value. The operating state detecting means may have a configuration in which a current detecting means (not shown) for detecting the operating current of the motor 6 is added to the rotation angle sensor 20. Also, this type of additional means includes a pad 3
-1, 3-2 or a torque sensor for detecting a braking torque generated by rotation of the rotor 2 by the pressed pads 3-1 and 3-2. When a linear motor is applied to the motor 6, the operating state detecting means detects an axial displacement.

When the driver does not depress the brake pedal 14, the electric brake device 1 contacts at least one of the pads 3-1 and 3-2 with the rotor 2. It has a contact detecting means for detecting. Further, when the contact detecting means detects contact between at least one of the pads 3-1 and 3-2 and the rotor 2, the electric brake device 1 removes the pads 3-1 and 3-2 from the rotor 2. There is a contact preventing means for driving the electric means 4 in a direction to be separated by a predetermined amount.

The above-mentioned contact detecting means can be provided with the piston 12, the ball screw mechanisms 8, 9 and the motor 6 without any additional means.
And an operating state detecting means. That is, when the thermal deformation of the rotor 2 returns to the original state during the idling immediately after the end of the braking, the pad 3-2
1, the caliper 5 moves to the left in FIG. 1, the pad 3-1 contacts the rotor 2, and the contact force causes the piston 12 to move to the right in FIG. The motor 6 is rotated in the reverse direction by a ball screw mechanism (male screw 8 and nut 9), and the reverse rotation is detected by a rotation angle sensor 20 which is operation state detecting means.
-1, 3-2 can be detected with the rotor 2.

Alternatively, a back electromotive force from the motor 6 rotating in the reverse direction, that is, a reverse rotation current, is detected by current detecting means as operating state detecting means. May be detected.

When a separate means is applied to the contact detecting means, an electric contact is provided on each of the rotor 2 and the pads 3-1 and 3-2, and means for detecting the contact between the two by a current caused by mutual contact between the contacts. Alternatively, it is also possible to provide a pressure sensor for detecting minute pressure on the piston 12 and apply a means for detecting contact between the two with an electric output of the pressure sensor to the contact detection means.

Further, the electric brake device 1 has a contact preventing means to be combined with the contact detecting means. That is, the contact prevention means has a combination configuration of the brake control means 18, the power supply unit 19, and the operation state detection means, and transmits the output of the above-described contact detection means to the brake control means 18 as an electric signal, The reverse rotation output power from the power supply unit 19 is supplied to the motor 6 via the means 18 to rotate the motor 6 in the reverse direction, thereby separating the pads 3-1 and 3-2 from the rotor 2 by a predetermined amount.

In FIG. 2, the rotor 2 and the pads 3-1 and 3-2 are not braked when the vehicle whose brake pedal 14 has no operation amount is not braked.
The brake control means 18 reads the output of the contact detection means for detecting contact with the vehicle (STEP 1), and determines whether or not there is contact (STEP 2). If the contact is detected (YES), the predetermined amount of piston 12 ( The pads 3-1 and 3-2) are driven to be separated from the rotor 2 (referred to as return, the same applies hereinafter). If the contact is not detected (NO), the operation returns to the contact detecting means again.

Next, in the second embodiment, FIG.
FIG. 4 is a schematic diagram of an overall configuration showing a cross section of a main part of the electric brake device of the present invention, FIG. 4 is a diagram showing a relationship between a rotor thermal deformation amount and a rotor temperature, and FIG. FIG. 6 is a relationship diagram between the estimated temperature of the rotor and the estimated temperature of the rotor, and the relationship between the estimated temperature of the rotor and the estimated amount of thermal deformation of the rotor. FIG. 6 shows the electric brake device shown in FIG. FIG. 7 is a flowchart for explaining the operation, and FIG.
FIG. 7 is a relationship diagram between a vehicle speed and a rotor heat transfer coefficient after the braking is completed.

The electric brake device 1 shown in FIG. 3 is similar to the electric brake device 1 described above with reference to FIG.
1 and the outside air temperature detecting means 22 are added, and only the detection signals of these means 21 and 22 are input to the brake control means 18 in FIG.
Is different from the electric brake device 1 shown in FIG. Therefore, the description of the configuration of the electric brake device 1 shown in FIG. 1 will be omitted here, and mainly the rotor thermal deformation estimating means having the vehicle speed detecting means 21 and the outside air temperature detecting means 22 and its operation will be described.

In FIG. 3, in the electric brake device 1, the contact prevention means described above has a thermal deformation amount estimating means for estimating the thermal deformation amount of the rotor 2. The means estimates the amount of thermal deformation of the rotor 2 as will be described in detail below, and in accordance with the estimated amount of thermal deformation, the contact prevention means operates the pad 3-1 from the rotor 2 in the same operation as the operation described above. 3-2 is separated by a predetermined amount.

That is, first, in FIG.
Is dependent on the shape of the rotor 2, the shape A has a linear relationship, the shape B has an upwardly convex curve relationship, and the shape C has an upwardly concave shape. Respectively. Regarding the rotor 2 of any shape, these correlations can be accurately obtained by experiments and analysis. For example, in the case of the rotor 2 having the shape A, the rotor 2
When the temperature Ta is determined, the thermal deformation amount θa of the rotor 2 is uniquely determined.

Here, the temperature of the rotor 2 includes the input energy to the rotor 2 calculated from the initial speed immediately before the start of vehicle braking and the end speed after the braking is completed, the speed during idle running after the braking is completed, and the vehicle speed. It can be estimated as the difference from the heat radiation energy determined by the ambient outside air temperature. That is, the scatter diagram of the rotor temperature shown on the right side of FIG. 5 shows the relationship between the actually measured temperature and the estimated temperature of the rotor 2 in the experiment performed by the inventors using the vehicles A and B. On a straight line of 1, ie 45
Since the error between the estimated temperature on the straight line of ° and the measured temperature is about 10% at the maximum, the temperature of the rotor 2 of various shapes can be estimated within this error range.

In the left diagram of FIG. 5, when contact between the rotor 2 and the pads 3-1 and 3-2 is detected by the contact detecting means, the rotor 2 having the shape A is estimated from the estimated temperature Tb of the rotor 2 at that time. Is estimated, and the estimated amount of thermal deformation θb is set as the amount of return of the piston 12. Thus, the pads 3-1 and 3-2 can be released from contact with the rotor 2.

In summary, the thermal deformation estimating means has a vehicle speed detecting means 21 for detecting a vehicle speed and an outside air temperature detecting means 22 for detecting an outside air temperature around the vehicle. The amount of thermal deformation of the rotor 2 based on the vehicle speed immediately before the start of braking detected by the vehicle 21, the vehicle speed after the braking is completed, the vehicle speed after the braking is completed, and the outside air temperature during the braking detected by the outside air temperature detecting means 22. Has the function of estimating Specifically, each of the detected values of the vehicle speed detecting means 21 and the outside air temperature detecting means 22 is used as a signal to control the brake control means 18.
The arithmetic processing unit calculates the amount of thermal deformation based on these input signals, outputs the calculation result to the amount of thermal deformation brake control means 18, and controls the brake control means.
18 drives the electric means 4 by a predetermined amount, and returns the pads 3-1 and 3-2 from the rotor 2. In this respect, the thermal deformation estimating means includes an arithmetic processing unit.

It should be noted that, even if the pads 3-1 and 3-2 are returned by an amount corresponding to the amount of thermal deformation when the braking is completed, the dragging phenomenon can be prevented, but the pad 3-3 on the piston 12 side can be prevented. In the wear mode in which the amount of uneven wear on the outer peripheral side of the rotor 2 is remarkable, the clearance c between the rotor 2 and the pads 3-1 and 3-2 becomes too large, and as a result, the brake responsiveness in the initial stage of braking decreases. Causes a malfunction. Therefore, the thermal deformation estimating means is activated only when the contact between the rotor 2 and the pads 3-1 and 3-2 is detected. Including this, below, based on FIG.
The operation of the second embodiment will be described.

In FIG. 6, STEP 1 and STEP 2 are the same as those in FIG. 2, and the reading of the vehicle speed in STEP 11 and the reading of the temperature in STEP 12 are always performed. In the state, the vehicle speed V1 immediately before the start of braking, the vehicle speed V2 when the braking is completed, and the vehicle speed V3 after the braking is completed are read.

In STEP 14, the heat input amount Ein and the heat release amount Eout of the rotor 2 are estimated by the following equations. First, the heat input Ein
Is calculated as the following equation based on the vehicle speed V1 immediately before the start of braking and the vehicle speed V2 when the braking is completed, assuming that the kinetic energy of the vehicle is lost by braking. Ein = K × W × (V1 ² −V2 ² ) / 2 where W is the gross vehicle weight, and K is the braking force distribution for the temperature estimation target rotor 2 in the braking operation. Is 60%: 40%, the braking distribution per front wheel is 1/2 of 60%, so that K = 0.3 for one front wheel.

Next, the heat radiation amount Eout is estimated by integrating the energy ΔEout, which is emitted from the rotor 2 during the execution cycle of the routine and is calculated by the following equation, from the time when the braking is completed to the lapse of a predetermined time. .DELTA.Eout = H.times.A.times..DELTA.t.times. (Tbo-Tam) Here, H is the heat transfer coefficient of the rotor 2, and this value is determined by the rotation speed of the wheels, that is, the vehicle speed V3 after the braking is completed. Calculated from the characteristics shown in A is the heat radiation area of the rotor 2, Δt is the routine execution cycle, Tbo is the temperature of the rotor 2 obtained in the previous routine execution, and Tam is the outside air temperature.

In STEP 15, the rotor 2 temperature Tb is calculated by the following equation.
Is estimated. Tb = {(Ein-Eout) / C} + To where C is the heat capacity of the rotor 2 and is obtained in advance by an experiment. To is the temperature of the rotor 2 immediately before the start of braking, and is determined based on the temperature Tb calculated by the routine after the previous braking. It is also assumed that the initial value of the temperature To is equal to the outside temperature Tam.

After the above-mentioned STEP 11 to STEP 15, in STEP 16, the rotor 2 temperature Tb and the thermal deformation amount of the rotor 2 are used based on the characteristics shown in FIG.
Estimate the amount of thermal deformation of, and input the estimated value of the amount of thermal deformation to the return amount reading of STEP 17, receive the return amount output of STEP 17, and
To return the piston 12 by a predetermined amount. This return
This can be done in one of two ways: (1) A method in which the amount of thermal deformation of the rotor 2 at the time of contact detection is estimated, and the piston 12 is returned at a stroke by a distance corresponding to the estimated amount of thermal deformation. This has the effect of increasing reliability in preventing contact with 3-1 and 3-2. (2) After the contact is detected, the piston 12 is gradually returned based on the estimated thermal deformation so that the rotor 2 and the pads 3-1 and 3-2 always maintain a constant clearance c. According to this method, the contact between the rotor 2 and the pads 3-1 and 3-2 can be prevented, and the brake responsiveness at the start of the next braking can be maintained.

Next, in the third embodiment, FIG.
FIG. 9 is a schematic diagram of the entire configuration showing a cross section of a main part of the electric brake device of the present invention. FIG. 9 is a schematic front cross-sectional view of wheels and a brake device of a traveling vehicle. FIG. FIG. 1 is a diagram showing a relationship between the rotation angle of the rotor and the amount of rotor tilt, and FIG.
FIG. 1 is a flowchart for explaining the operation of the electric brake device using the lateral acceleration detecting means shown in FIG.

In the electric brake device 1 shown in FIG. 8, a lateral acceleration detection means 23 is added to the contact prevention means of the electric brake device 1 shown in FIG. 1, and a lateral acceleration detection signal of the means 23 is input to the brake control means 18. The only difference from the electric brake device 1 shown in FIG. Therefore, description of the configuration of the electric brake device 1 shown in FIG.
The contact preventing means and the lateral acceleration detecting means 23 will be described.

In FIG. 8, when a lateral acceleration is input to the vehicle by turning or the like, the vehicle is driven by a roll input so that the rotary shaft 24 and the wheels 25 and the rotor 2 fixed to the rotary shaft 24 when the vehicle is traveling straight ahead are obtained. Falls from the position shown by the broken line to the position shown by the solid line, and tilts with respect to the rotating shaft 24 as shown by the solid line. This inclination causes contact between the rotor 2 and the pads 3-1 and 3-2. At this time, two actions are taken.

First response: When this contact occurs, in the electric brake device 1 shown in FIG. 1, the contact detecting means operates, and the pad 3-3 is released from the rotor 2 so as to release the contact.
Separate 1, 3-2. However, this contact naturally returns to the non-contact state when the lateral acceleration is lost.
When 1, 3-2 is separated from rotor 2, clearance c
Becomes too large, which degrades the brake responsiveness during the next braking.

Therefore, a lateral acceleration detecting means is used as the contact preventing means.
23, when the contact detecting means detects the contact between the rotor 2 and the pads 3-1 and 3-2 at the time of non-braking, when the lateral acceleration detected by the lateral acceleration detecting means 23 is equal to or more than a predetermined value, the contact is prevented. The means functions to inhibit the drive of the electric means 4 for separating the pads 3-1 and 3-2 from the rotor 2. More specifically, the brake control unit 18 receives the lateral acceleration signal input from the lateral acceleration detection unit 23 and controls the electric unit 4 to be non-driven when the lateral acceleration is equal to or more than a predetermined value. is there.

Second response: Apart from the above, a lateral acceleration detecting means 23 is added to the contact preventing means, and the contact detecting means detects the contact between the rotor 2 and the pads 3-1 and 3-2 when the brake is not applied. When the lateral acceleration detected by the lateral acceleration detecting means 23 is equal to or more than a predetermined value, the contact preventing means drives the electric means to move the pads 3-1 and 3-2 from the rotor 2 according to the value of the lateral acceleration. Separate by a fixed amount. On the other hand, when the detected lateral acceleration detected by the lateral acceleration detecting means 23 is restored to a value less than the predetermined value, the contact preventing means drives the electric means 4 in the opposite direction to the above, and the rotor 2 and the pad 3-1, 3-2 to function to restore the clearance c. This is a series of operations from the start of turning to the end of turning of the vehicle.
Run through 18.

Here, FIG. 10 shows a relationship diagram between the amount of tilt of the rotor 2 and the lateral acceleration due to the lateral acceleration shown in FIG. In FIG. 10, the lateral acceleration and the amount of tilt of the rotor 2 have a linear relationship. Therefore, in the second correspondence, the pad 3-1 has an amount determined based on FIG. 3-2, it is possible to prevent the rotor 2 from contacting the pads 3-1 and 3-2 due to lateral acceleration. Further, when the rotor 2 falls down, the lateral acceleration is G
Since the above occurs, it is preferable to set the predetermined value of the lateral acceleration in the first and second correspondences to Go.

The first and second correspondences will be described with reference to a flowchart. In FIG. 11, the lateral acceleration (hereinafter referred to as lateral G, hereinafter the same) is read by the lateral acceleration detecting means 23 in STEP 21, and this signal is When the lateral acceleration is equal to or more than the predetermined value Go in STEP22, the data is transmitted to the brake control means 18.
In this case, as the position control of the piston 12 in consideration of the lateral G, the return of the piston 12 related to the lateral acceleration is not executed in the first correspondence, and the tilt amount characteristic of the rotor 2 shown in FIG. , The piston 12 is returned so that the rotor 2 does not contact the pads 3-1 and 3-2. If the lateral acceleration is less than the predetermined value Go, STEP24 to STEP26
Then, the operation of returning the piston 12 is executed in the same manner as in STEP1 to STEP3 of FIG. Here, instead of STEP 26, the piston 12 may be returned by the operations shown in STEP 11 to STEP 18 shown in FIG.

[0054]

According to the first to ninth aspects of the present invention, contact between the brake friction material and the brake rotating body is detected during non-braking, and when the contact is detected, the brake friction material is removed. By returning, the brake friction material is separated from the brake rotator under proper clearance during non-braking during the entire running process of the vehicle, thereby suppressing the occurrence of the brake drag phenomenon and, at the same time, An electric brake device capable of maintaining responsiveness can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an overall configuration showing a cross section of a main part 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 shown in FIG.

FIG. 3 is a schematic diagram of an overall configuration showing a cross section of a main part of an electric brake device according to a second embodiment of the present invention;

FIG. 4 is a diagram showing a relationship between a rotor thermal deformation amount and a rotor temperature.

FIG. 5 is a relationship diagram between the measured rotor temperature and the estimated rotor temperature and a relationship diagram between the estimated rotor temperature and the estimated amount of thermal deformation of the rotor.

6 is a flowchart illustrating the operation of the electric brake device shown in FIG. 3 using the thermal deformation amount estimating means.

FIG. 7 is a relationship diagram between a vehicle speed and a rotor heat transfer coefficient after braking is completed.

FIG. 8 is a schematic diagram of an overall configuration showing a cross section of a main part of an electric brake device according to a third embodiment of the present invention.

FIG. 9 is a schematic front sectional view of a wheel and a brake device of a traveling vehicle.

FIG. 10 is a diagram showing the relationship between the lateral acceleration of the vehicle and the amount of fall of the rotor.

FIG. 11 is a flowchart illustrating an operation of the electric brake device using the lateral acceleration detection unit shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric brake device 2 Rotor 3 Pad 4 Electric means 5 Caliper 6 Motor 7 Rotary shaft 8 Ball screw male screw 9 Ball screw nut 10 Groove 11 Guide member 12 Piston 14 Brake pedal 15 Brake command value generating means 16 Tread force sensor 17 Stroke Sensor 18 Brake control unit 19 Power supply unit 20 Rotation angle sensor 21 Vehicle speed detection unit 22 Outside temperature detection unit 23 Lateral acceleration detection unit 24 Rotation axis 25 Wheel

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Claims (9)

[Claims] 1. An electric means for pressing / separating a brake friction material supported on a vehicle body side of a vehicle with respect to a brake rotating body which rotates with wheels, an operating state detecting means for detecting an operating state of the electric means, a driver Brake command generation means for determining a brake command value in accordance with the brake operation amount of the brake; brake control means for controlling a drive amount of an electric means to match the operation state with the brake command value; Contact detecting means for detecting contact between the friction material and the brake rotator; and when the contact detection means detects contact of the brake friction material with the brake rotator, a predetermined amount of the brake friction material is supplied from the brake rotator. An electric brake device comprising: a contact prevention unit that drives an electric unit in a direction to separate the electric brake unit. 2. The electric brake according to claim 1, wherein said contact detecting means has a configuration for detecting a contact of a brake friction material with a brake rotating body based on a detection result of said operating state detecting means. apparatus. 3. The contact detecting means transmits the contact of the brake friction material with the brake rotating body to an operating state detecting means of the electric means, and in response to the transmission, the operating state detecting means commands the driving of the electric means. The electric brake device according to claim 1, wherein the electric brake device has a configuration. 4. The operating state detecting means includes a displacement detecting means for detecting one of a rotational angular displacement and an axial displacement of the electric means, and a current detecting means for detecting an operating current of the electric means. Claims 1-3 characterized by the above-mentioned.
An electric brake device according to any one of the preceding claims. 5. The contact prevention means includes a thermal deformation amount estimating means for estimating a thermal deformation amount of the brake rotator, and the contact prevention means is provided in accordance with the thermal deformation amount of the brake rotator estimated by the means. 2. The electric brake device according to claim 1, wherein the electric brake device has a function of separating the brake friction material from the brake rotating body by a predetermined amount. 6. The thermal deformation amount estimating means includes a vehicle speed detecting means for detecting a vehicle speed, and an outside air temperature detecting means for detecting an outside air temperature around the vehicle. Based on the vehicle speed, the vehicle speed at the time of braking completion, the vehicle speed after the braking is completed, and the outside air temperature at the time of braking detected by the outside air temperature detecting means, the thermal deformation amount estimating means calculates the amount of thermal deformation of the brake rotator. The electric brake device according to claim 5, which has a function of estimating. 7. The contact preventing means has a lateral acceleration detecting device for detecting a lateral acceleration generated in the vehicle, and when the contact detecting means detects a contact between the brake friction material and the brake rotating body during non-braking. The contact preventing means has a function of prohibiting the driving of the electric means for separating the brake friction material from the brake rotating body by a predetermined amount when the lateral acceleration detected by the lateral acceleration detecting device is equal to or more than a predetermined value. 1
Or the electric brake device according to 5. 8. The contact preventing means has a lateral acceleration detecting device for detecting a lateral acceleration generated in the vehicle, and when the contact detecting means detects a contact between the brake friction material and the brake rotating body during non-braking. The contact preventing means has a function of driving the electric means to separate the brake friction material from the brake rotating body by an amount determined based on the detected lateral acceleration when the lateral acceleration detected by the lateral acceleration detecting device is equal to or more than a predetermined value. The electric brake device according to claim 1 or 5, wherein: 9. When the detected lateral acceleration is restored to a value less than a predetermined value, the contact prevention means drives the electric means in the opposite direction to restore the clearance between the brake rotor and the brake friction material. The electric brake device according to claim 8, having a function.