JP2018001775A - Vehicular brake device - Google Patents

Abstract

An object of the present invention is to reduce the cost of a hydraulic pressure generating means of a single system, and to stop a vehicle by regenerative braking of a driving electric motor of a vehicle when the hydraulic pressure generating means malfunctions. Kind Code: A1 When an abnormality of a by-wire brake means is detected, an EV control device permits regenerative braking by a drive motor, and regenerative energy of the drive motor is regenerated into a battery to generate four electric power sources. A braking force is applied to both front wheels of the wheels 2 . Therefore, in normal operation, the vehicle can be braked by the by-wire brake means 8, which is one system of hydraulic pressure generating means. As a result, regenerative braking by the drive motor 3 is allowed and regenerative braking is performed. [Selection drawing] Fig. 1

Description

  The present invention relates to a vehicle brake device that includes a motor for driving a vehicle and regenerates regenerative energy from the motor to a battery to generate a braking force.

  Conventionally, in an electric vehicle (EV) equipped with an electric motor (motor) for driving a vehicle and a hybrid vehicle equipped with an engine and an electric motor (motor) for driving, the driver applies a brake pedal pressure by using a brake negative pressure. Instead of amplifying, the brake hydraulic pressure amplified using the driving force of the motor of the electric cylinder device is supplied to the wheel cylinder (see Patent Document 1), and this type of electric cylinder device is mounted. For example, the brake device is configured as shown in FIGS.

  That is, FIG. 3 shows an example of an electric vehicle. A driving motor 54 is connected to the axle 53 of the front wheels 52L and 52R of the vehicle 51, and is supplied from the battery 55 to the motor 54 via the inverter 56. A drive current corresponding to the amount of depression of an accelerator pedal (not shown) is supplied under the control of a certain EV ECU 57, and the vehicle 51 is driven to travel at a speed corresponding to the depression of the accelerator pedal. The rear wheels 58L and 58R are connected to the axle 59 and driven.

  Further, in response to depression of the brake pedal 61, the brake ECU 62 controls the vehicle brake system 63 to generate a braking force. The vehicle brake system 63 is configured as shown in FIG. 4, and when the brake pedal 61 is depressed, the electric cylinder device is operated by the brake ECU 62 in a state where the master cylinder 64 and the electric cylinder device 65 are disconnected. 65 motors are controlled, and the brake hydraulic pressure amplified by the driving force of the motors is applied to the wheel cylinders 66 of the respective wheels 52R, 52L, 58R, 58L, for example, provided on the respective wheels 52R, 52L, 58R, 58L. A friction braking force is generated by the disc brake 67. FIG. 4 shows only the right front wheel 52R.

  Further, as shown in FIG. 4, a vehicle behavior stabilization device 68 is provided as the vehicle brake system 63, and the amount of depression of the brake pedal 61 is detected by a stroke sensor or the like, and the motor, valve, etc. of the vehicle behavior stabilization device 68 are detected. Is controlled, and the brake hydraulic pressure by the master cylinder 64 is applied to the wheel cylinders 66 of the wheels 52R, 52L, 58R, 58L. At that time, no side slip is generated corresponding to the side slip or the like while the vehicle 51 is traveling. In addition, the wheel cylinders 66 of the wheels 52R, 52L, 58R, 58L are individually controlled to keep the vehicle behavior stable. Further, when an abnormality occurs in the electric cylinder device 65 and the friction braking force can no longer be generated, the vehicle behavior stabilization device 68 performs control to generate a braking force equivalent to the engine brake.

Japanese Patent Laying-Open No. 2014-213628 (see paragraphs 0046-0053, FIGS. 1 and 2)

  However, in the brake device described in Patent Document 1 described above, it is necessary to provide two systems of hydraulic pressure generation means, that is, an electric cylinder device 65 and a vehicle behavior stabilization device 68, and there is a problem in that the cost increases. Furthermore, when an abnormality occurs in the electric cylinder device 65, the vehicle behavior stabilization device 68 can generate only a braking force equivalent to the engine brake, and the braking performance is insufficient, and the driving motor 54 of the vehicle 61 is used. Effective utilization of regenerative braking is desired.

  An object of the present invention is to make it possible to reduce costs as compared with the conventional system as a single hydraulic pressure generating means, and to stop the vehicle by a braking force generated by regenerative braking of a vehicle driving motor when the hydraulic pressure generating means is abnormal. To do.

  In order to achieve the above-described object, a vehicle brake device according to the present invention includes a vehicle drive motor, and regenerates energy generated by the motor to a battery to generate a braking force. Detecting the presence or absence of abnormality in the hydraulic pressure generating means that generates brake hydraulic pressure in response to the depression of each wheel and braking each wheel, and when the abnormality is detected, regenerative braking is performed by the electric motor. And an allowable control means.

  According to such a configuration, since the vehicle can be braked by one system of hydraulic pressure generating means in normal operation, the cost can be reduced as compared with the prior art. Further, when the control means detects that there is an abnormality in the hydraulic pressure generating means that generates the brake hydraulic pressure in response to the depression of the brake pedal, regenerative braking by the drive motor is allowed, so the drive is not performed by the hydraulic pressure generating means. It becomes possible to stop the vehicle by regenerative braking by the electric motor.

  Further, the control means raises a full charge threshold value of a remaining battery capacity which is a reference for judging that the battery is fully charged when the abnormality of the hydraulic pressure generating means is detected, and performs regenerative braking by the electric motor. May be allowed. According to this configuration, when the control means detects that there is an abnormality in the hydraulic pressure generating means and starts regenerative braking by the driving motor, the regenerative braking cannot be performed if the battery is fully charged, but the hydraulic pressure is generated. When the abnormality of the means is detected, the full charge threshold value of the remaining battery capacity to be determined as the battery is fully charged is raised by the control means, so that the regenerative energy by the driving motor can be regenerated to the battery, You can start braking immediately and stop. At this time, the regenerative energy is derived from the kinetic energy at the vehicle speed during normal traveling, and the amount of increase in the full charge threshold of the remaining battery capacity may be set so that the derived regenerative energy can be regenerated in the battery.

  Further, the control means may perform control to flow a driving current from the battery to the electric motor when detecting the abnormality of the hydraulic pressure generating means. In this way, when the control means detects that there is an abnormality in the hydraulic pressure generation means, regenerative braking is performed by the drive motor and at the same time, a drive current is passed to the drive motor, so the regenerative energy of the drive motor is reduced. Is released as heat and regenerative braking can be performed.

  According to the present invention, since the vehicle can be braked by one system of hydraulic pressure generating means in normal operation, the cost can be reduced as compared with the prior art, and the control means detects the abnormality of the hydraulic pressure generating means. When this is done, regenerative braking by the drive motor is allowed, so that the vehicle can be stopped by regenerative braking by the drive motor instead of the hydraulic pressure generating means.

1 is a block diagram of an embodiment of a vehicle brake device according to the present invention. It is operation | movement explanatory drawing of FIG. It is a schematic block diagram of a prior art example. It is a block diagram of a prior art example.

  An embodiment in which the vehicle brake device according to the present invention is mounted on an electric vehicle will be described in detail with reference to FIGS. 1 and 2. FIG. 1 shows only one of the front wheels.

  The vehicle brake device 1 of the present embodiment is configured as shown in FIG. 1, and a vehicle drive motor 3 is connected to the axles of the left and right front wheels 2. The drive current from B is supplied to the drive motor 3 to drive the vehicle. At this time, the EV control device supplies a drive current corresponding to the amount of depression of the accelerator pedal (not shown), and the vehicle is driven to travel at a speed corresponding to the depression of the accelerator pedal.

  In addition, as shown in FIG. 1, a brake control device, a motor, and a valve having a microcomputer configuration are provided so that the depression amount of the brake pedal 6 is detected by a stroke sensor 7 and a brake hydraulic pressure is generated according to the detected depression amount. The included by-wire brake means 8 is operated, and the brake hydraulic pressure corresponding to the depression of the brake pedal 6 is applied to the wheel cylinder 9 provided on each wheel 2, and the brake means 10 such as a disc brake provided on each wheel 2 A friction braking force is generated. Further, in order to prevent a side slip of the vehicle, the brake oil pressure to the wheel cylinder 9 of each wheel 2 is individually controlled by the by-wire brake means 8 when the side slip of the vehicle accompanying the generation of the friction braking force occurs. Here, the by-wire brake means 8 corresponds to the hydraulic pressure generating means in the present invention.

  If an abnormality occurs in the by-wire brake means 8 due to a failure of a motor or a valve constituting the by-wire brake means 8, the brake control device of the by-wire brake means 8 determines that “there is an abnormality”. Based on this, regenerative braking by the drive motor 3 is allowed by the EV control device 4, the drive motor 3 functions as a generator, and the regenerative energy generated by the power generation is regenerated by the battery B, and the left and right front wheels of the four wheels 2 are regenerated. The braking force by regenerative braking is applied to the. Here, the by-wire brake means 8 and the EV control device 4 correspond to the control means in the present invention.

  By the way, the full charge threshold value of the remaining battery capacity, which is a reference for determining that the battery B is fully charged, is set to a value lower than 100% (for example, 95%) in consideration of the life of the battery B. It is common to be done. Therefore, in order to prevent the regenerative energy from being regenerated when the battery 4 is fully charged when the abnormality occurs in the by-wire brake unit 8, as shown in FIG. When the full charge threshold value of the remaining battery capacity, which is a reference for determining that the battery B is fully charged by the device 4, is set to 95% of the fully charged state, for example, the presence of abnormality in the by-wire brake means 8 is detected. The full charge threshold of the remaining battery capacity is raised to, for example, 100% by the EV control device 4.

  At this time, for example, the regenerative energy necessary to completely stop the vehicle during regenerative braking is derived in advance from the kinetic energy of the vehicle when traveling normally on an expressway at 80 km / h, and the derived regenerative energy is stored in the battery. What is necessary is just to set the raising amount of the full charge threshold value of a battery remaining capacity so that it can regenerate to B. For example, in the description of FIG. 2, the full charge threshold of the remaining battery capacity is increased by 5% from 95% in the normal state to 100%, but the increased value is not limited to 5%. What is necessary is just to raise the full charge threshold value of battery remaining capacity to a fixed value so that the regenerative energy which can stop the inside vehicle by one regenerative braking operation can be regenerated to the battery B.

  Therefore, according to the above-described embodiment, in the normal operation, the vehicle can be braked by the by-wire brake means 8 which is one system of hydraulic pressure generating means. Therefore, when the conventional two systems of hydraulic pressure generating means are provided, Compared with this, the cost can be reduced.

  When the abnormality of the by-wire brake means 8 is detected, the EV control device 4 allows the regenerative braking by the drive motor 3, so that the vehicle is not driven by the regenerative braking by the drive motor 3 but by the by-wire brake means 8. You can stop.

  Further, when the abnormality of the by-wire brake means 8 is detected and the regenerative braking by the driving motor 3 is started, the regenerative braking cannot be performed if the battery is fully charged, but there is an abnormality of the by-wire brake means 8. When detected, the full charge threshold value of the remaining battery capacity, which is determined to be full battery charge, is raised by the EV control device 4, so that the regenerative braking by the drive motor 3 can be started immediately and stopped, and the by-wire brake means 8 It becomes possible to make an emergency stop when an abnormality occurs.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, when the abnormality of the by-wire brake means 8 is detected, the EV control device 4 causes the driving motor 3 to start moving at the same time, and at the same time, the battery B is connected to the driving motor 3. You may make it perform the control which flows the drive current by. In this way, when the abnormality is detected in the by-wire brake means 8 by the EV control device 4, regenerative braking is performed by the drive motor 3, and at the same time, a drive current is passed through the drive motor 3, thereby driving The regenerative energy of the electric motor 3 is released as heat, and regenerative braking can be performed.

  Further, in the above-described embodiment, the case where the full charge threshold of the remaining battery capacity is increased by a certain value (such as 5%) when the abnormality occurs in the by-wire brake unit 8 has been described. However, the criterion for determining that the battery B is fully charged The increase value of the full charge threshold of the remaining battery capacity may be variably set according to the vehicle speed at the time of starting the regenerative braking accompanying the abnormality of the by-wire brake means 8.

DESCRIPTION OF SYMBOLS 1 ... Brake device 3 ... Electric motor for drive 4 ... EV control apparatus (control means)
8 ... By-wire brake means (hydraulic pressure generating means, control means)
B battery

Claims (3)

In a vehicle brake device comprising a motor for driving a vehicle and generating a braking force by regenerating regenerative energy from the motor to a battery,
Hydraulic pressure generating means for generating a brake hydraulic pressure corresponding to depression of the brake pedal to brake each wheel;
A vehicle brake device comprising: control means for detecting presence or absence of abnormality of the hydraulic pressure generation means and allowing regenerative braking by the electric motor when abnormality is detected.   When the control means detects the abnormality of the hydraulic pressure generation means, the control means raises a full charge threshold value of a remaining battery capacity that is a reference for determining that the battery is fully charged, and allows regenerative braking by the electric motor. The vehicle brake device according to claim 1, wherein:   3. The vehicle brake device according to claim 1, wherein the control unit performs control to flow a driving current from the battery to the electric motor when detecting an abnormality of the hydraulic pressure generation unit. 4. .

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