JP2012205318A - Braking device - Google Patents

Abstract

A braking device capable of efficiently processing surplus regenerative power is provided.
When regenerative braking of a vehicle, when a battery charge state determination unit 33 determines that the terminal voltage of the battery 30 is lower than a threshold value, the battery 30 is energized with regenerative power generated by the regenerative braking. It controls so that 30 may be charged. Further, when the battery charge state determination unit 33 determines that the terminal voltage of the battery 30 is equal to or higher than a predetermined threshold, the aerodynamic brake drive device 22 is operated and regenerative power is supplied to the aerodynamic brake heating resistor 21. And control to be consumed as heat.
[Selection] Figure 1

Description

  The present invention relates to a braking device, and more particularly to a vehicle braking device that includes a motor for driving a vehicle and regenerates kinetic energy of the vehicle by an electric motor (motor) when the vehicle is decelerated.

  In recent years, hybrid vehicles (so-called HV vehicles) using an internal combustion engine and an electric motor as power sources and electric vehicles (so-called EV vehicles) driven by an electric motor have begun to spread from the viewpoints of environmental problems and fuel consumption. These vehicles are propelled by driving wheels with the output torque of an electric motor (motor) during traveling. On the other hand, when the vehicle is decelerating, the motor is operated as a generator, the kinetic energy of the vehicle is regenerated (regenerative torque is generated) to be converted into electric power, and this regenerative electric power is stored in a capacitor (battery). Braking. At this time, when the battery is in a fully charged state, problems such as deterioration of the battery due to overcharging and excessive increase of the terminal voltage occur.

  In order to prevent such a problem, an apparatus that responds to a demand for surplus power generated by regenerative braking to be consumed by a method other than charging the battery has been proposed. For example, Patent Document 1 describes a hybrid vehicle that dissipates heat generated by excess regenerative power using existing heat dissipating means (radiators). Patent Document 2 discloses a regenerative braking device for an electric vehicle that converts surplus regenerative power into heat by a motor or an inverter and processes the heat.

JP-A-6-319205 JP-A-5-252606

  In the hybrid vehicle described in Patent Document 1 described above, surplus regenerative power is dissipated through the radiator, and the regenerative braking device described in Patent Document 2 is converted into heat inside the drive motor and consumed by the heat. However, in either case, the capacity for heat dissipation treatment is not sufficient, so it is necessary to limit the regenerative amount itself. In addition, since it is difficult to consume all the generated regenerative power as heat, the heat conversion process using a friction brake is mainly performed even though the regenerative system is installed. For this reason, there is a problem that the friction brake capacity is the same as that of a conventional vehicle brake, and the brake cannot be made smaller and lighter. In addition, even if a regenerative system is installed, there is a problem that the amount of airflow to the tire house, which has a great influence on the air resistance of the vehicle, is equivalent to the conventional one, and the brake is not improved in size.

  The present invention has been proposed to solve the above-described problem, and an object of the present invention is to provide a braking device that can efficiently process surplus regenerative power generated by regenerative braking of a vehicle.

  In order to achieve the above object, the invention according to claim 1 is a braking device that realizes deceleration of the vehicle by generating regenerative electric power using the drive motor of the vehicle as a generator during braking of the vehicle. An aerodynamic brake installed at a predetermined position of the vehicle; a heating resistor provided in the aerodynamic brake; a battery charge state determination unit that determines a charge state of a battery during braking of the vehicle; and the battery charge state When it is determined by the determination means that the battery is in a chargeable state, control is performed so that the battery is charged by the regenerative power, and the battery is in a fully charged state by the battery charge state determination means. If it is determined, the control means for operating the aerodynamic brake and controlling the regenerative power to be energized to the heating resistor. And, equipped with a.

  With such a configuration, only the excess regenerative power that cannot be fully charged in the battery is consumed as heat by the heating resistor provided in the aerodynamic brake, and the amount of energy converted into heat in the friction brake is reduced. Can do. Further, the vehicle is decelerated by operating the aerodynamic brake, thereby reducing the regenerative power generated as a surplus in the drive motor.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the control unit determines that the battery is in a fully charged state by the battery charge state determination unit, the regenerative power is converted into the heating resistance. Control is performed so that the aerodynamic brake is energized at the same time as the body is energized. Thereby, surplus regenerative power generated by the drive motor can be consumed more efficiently.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the aerodynamic brake includes a movable flap member, and the heating resistor is disposed to be exposed on the surface of the flap member. It is characterized by. According to a fourth aspect of the present invention, in the first or second aspect of the invention, the aerodynamic brake includes a movable flap member, and the heating resistor is built in the flap member. . The invention according to claim 5 is the invention according to claim 1 or 2, wherein the aerodynamic brake is provided with a movable flap member, the heating resistor is disposed on the surface of the flap member, and is protected. It is characterized by being provided with a coating for.

  By disposing the heating resistor as described above, the heat generated by the heating resistor can be efficiently radiated to the air hitting the movable flap member.

  The braking device according to the present invention has an excellent effect that it can efficiently process surplus regenerative power, and that the aerodynamic brake itself suppresses the generation of surplus regenerative power and can reduce the size and weight of the friction brake.

1 is a block diagram illustrating an overall configuration of a braking device according to an embodiment of the present invention. It is a figure which shows the structure of the aerodynamic brake part of the braking device which concerns on embodiment. It is a flowchart which shows the control procedure of the regenerative braking which act | operated the aerodynamic brake in the braking device which concerns on embodiment. It is a block diagram which shows the whole structure of the braking device which concerns on the modification of embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing an overall configuration of a braking device according to an embodiment of the present invention. In the braking device 1 shown in FIG. 1, an electronic control unit (ECU) 10 includes a central control unit (CPU: Central Processing Unit) (not shown) that controls the entire braking device 1, and an operating system (OS ) And the like, a read-only memory (ROM) (not shown) in which a program indicating a control procedure for regenerative braking and the like are stored, and various data used for regenerative braking control (not shown) are temporarily stored. A read / write memory (RAM) is provided as needed.

  The motor 12 is used, for example, as a drive motor that applies a driving force (rotational force) to the wheels (drive wheels) 5a and 5b via a power transmission unit 7 formed of a differential gear or the like, and generates regenerative energy during braking. Used as a regenerative motor for recovery. Here, if the vehicle equipped with the braking device 1 according to the present embodiment is an electric vehicle, the power from the battery 30 is frequency-converted and voltage-converted by an inverter (not shown) and supplied to the motor 12 during normal driving. Is done. If the vehicle is a hybrid vehicle, the motor 12 constitutes a drive source for the hybrid vehicle together with an internal combustion engine (not shown) or alone.

  On the other hand, in both the case of an electric vehicle and a hybrid vehicle, regenerative braking functions when the vehicle decelerates, and the motor 12 generates power by the rotational force (mechanical power) transmitted from the wheels 5a and 5b to the motor 12. As driven. As a result, braking force is generated on the wheels 5a and 5b to decelerate the vehicle, and the electric power generated by the motor 12 is converted into predetermined DC power by a rectifier (not shown) and stored in the battery 30. The battery 30 is a secondary battery such as a nickel metal hydride battery or a lithium ion battery.

  The battery charge state determination unit 33 constantly monitors the terminal voltage of the battery 30 and determines the charge state of the battery 30 based on the monitoring result. The power switch 15 is a switch that switches between electrically connecting the motor 12 and the battery 30 or electrically connecting the motor 12 and the aerodynamic brake unit 20. The ECU 10 charges the battery 30 with regenerative power generated during regenerative braking of the vehicle by switching the power selector switch 15 based on a determination signal from the battery charge state determiner 33, or uses this regenerative power as an aerodynamic force. The brake unit 20 is supplied. The aerodynamic brake unit 20 includes an aerodynamic brake drive device 22 that operates the aerodynamic brake and a heat generating resistor 21 in the aerodynamic brake.

  FIG. 2 is a diagram illustrating a configuration of the aerodynamic brake unit 20 of the braking device according to the present embodiment. As shown in FIG. 2, for example, the aerodynamic brake unit 20 is provided with a flap (brake plate) 25 for an aerodynamic brake on one side by a driving force of an aerodynamic brake driving device 22 that operates by receiving power supply from a battery 30. The hinge part 23 is controlled to be rotatable in the vertical direction. The flap 25 is made of a panel-like member having a predetermined area, and has an aerodynamic brake heating resistor 21 made of resistance for consuming the regenerative power supplied from the motor 12 as heat. Here, in order to efficiently dissipate the heat generated by the heat generating resistor 21 in the aerodynamic brake into the air, the air flow is significant during the traveling of the vehicle 50, and the heat generated in the aerodynamic brake on the rear roof of the vehicle 50. A resistor 21 is arranged. Further, by disposing the flap 25 on the rear roof of the vehicle 50, the influence on the occupant due to the heat generated from the heating resistor 21 in the aerodynamic brake is minimized.

  The aerodynamic brake heating resistor 21 is, for example, arranged so as to be exposed while meandering on the surface of the flap 25. The arrangement method of the heat generating resistor 21 in the aerodynamic brake is not limited to this. For example, when the heating resistor 21 is disposed on the surface of the flap 25, a protective covering (cover) may be provided thereon, or the surface of the flap 25 may be provided. Alternatively, it may be embedded in the flap 25 by being embedded at a predetermined depth.

  Next, a control method for regenerative braking in the braking apparatus according to the present embodiment will be described. FIG. 3 is a flowchart showing a control procedure of regenerative braking in which the aerodynamic brake is operated in the braking apparatus according to the present embodiment. In step S11, the ECU 10 of the braking device 1 determines whether the vehicle is in regenerative braking based on a speed signal from a speed sensor (not shown), a brake signal from the brake sensor, an accelerator signal from the accelerator sensor, and the like. Judge whether or not. Specifically, when the brake pedal is depressed (the brake switch is turned on), the vehicle speed obtained from the speed signal is equal to or lower than a predetermined value, and the accelerator switch is turned off, it is determined that the vehicle is in regenerative braking. To do. If it is determined in step S11 that the vehicle is not in regenerative braking, another process in step S20 is executed. For example, the battery 30 and the motor 12 are connected by switching the power switch 15, and DC power from the battery 30 is converted into AC power by an inverter (not shown) according to an accelerator signal. Then, the AC power is supplied to the motor 12 to drive the motor 12, and the driving force is transmitted to the wheels 5a and 5b, so that processing in a normal traveling state is performed.

If it is determined that the vehicle is in regenerative braking, the ECU 10 receives a determination signal regarding the charging state of the battery 30 from the battery charging state determination unit 33 in step S13, and whether the battery 30 is in a chargeable state. Judge whether or not. Here, the battery state of charge determiner 33 monitors the terminal voltage V of the battery 30, the terminal voltage V inputs the determination signal indicating whether or lower than the threshold value V _F decided advance in ECU 10. When the terminal voltage of the battery 30 is lower than a predetermined threshold value, the battery 30 can be charged. When the terminal voltage of the battery 30 is equal to or higher than the threshold value, the battery 30 is fully charged and charged. It indicates that it is not possible.

ECU10 in step S13, the determination signal from the battery charging state determining unit 33 is lower than the terminal voltage V is the threshold _{V F} of the battery 30, when the battery 30 is determined to be in a chargeable state, in step S15 move on. In step S15, since the vehicle is in regenerative braking and the battery 30 is in a chargeable state, the ECU 10 sets the power changeover switch 15 so that the regenerative power generated by the motor 12 is charged in the battery 30. The electrical connection between the motor 12 and the battery 30 is maintained. As a result, the regenerative power from the motor 12 is charged in the battery 30. Then, ECU 10 is in the subsequent step S19, the charging of the battery 30, determines whether the terminal voltage V of the battery 30 is higher than the threshold value _{V F.} Specifically, similarly to step S13, inputted from the battery state of charge determiner 33, based on the determination signal of the terminal voltage V of the battery 30, the terminal voltage V of the battery 30 is lower than the threshold V _F or, alternatively to determine a threshold value V _F or more.

ECU10 in step S13, or step S19, inputted from the battery state of charge determiner 33, based on the determination signal of the terminal voltage V of the battery 30, the terminal voltage V of the battery 30 is the threshold value _{V F} above If it is determined that the battery 30 is fully charged, the process proceeds to step S21. That is, the ECU 10 determines that the battery 30 is in a fully charged state and cannot be further charged, and switches the power switch 15 to the aerodynamic brake unit 20 side in step S21. As a result, the regenerative current from the motor 12 is energized to the aerodynamic brake heating resistor 21. Note that regenerative power that is not fully charged in the battery 30 (regenerative power that is desired to be consumed by a method other than charging the battery) is called surplus regenerative power.

  In subsequent step S23, the ECU 10 sends a control signal to the aerodynamic brake drive device 22 constituting the aerodynamic brake unit 20 to operate the aerodynamic brake drive device 22 in order to operate the aerodynamic brake. When the aerodynamic brake drive device 22 is activated, the flap 25 of the aerodynamic brake portion 20 is rotationally driven in the upward direction of the vehicle about the one side provided with the hinge portion 23 by the driving force of the aerodynamic brake drive device 22 to a predetermined angle. It keeps still while maintaining. As a result, a large amount of air hits the flap 25 while the vehicle is running, and a large amount of air also hits the heating resistor 21 in the aerodynamic brake that generates heat due to energization of regenerative power. The generated heat is efficiently radiated into the air. In this way, regenerative electric power generated during regenerative braking of the vehicle is consumed as heat in the aerodynamic brake heating resistor 21.

  In step S27, the ECU 10 determines whether or not the vehicle is in a regenerative braking state based on the vehicle speed, the brake state, the accelerator state, and the like as in step S11. If the vehicle is still in the regenerative braking state, in step S23, the operation of the aerodynamic brake drive device 22 is continued while the regenerative power is supplied to the aerodynamic brake heating resistor 21. However, if it is determined in step S27 that the vehicle is not in the regenerative braking state, the ECU 10 switches the power selector switch 15 to the battery 30 side in step S29. When the operation of the aerodynamic brake drive device 22 is stopped in the subsequent step S31, the flap 25 returns to the initial position, for example, the same plane as the rear roof of the vehicle. And ECU10 complete | finishes control of this regenerative braking.

  As described above, in step S29, the power switch 15 is switched so that the battery 30 and the motor 12 are electrically connected, so that the DC power from the battery 30 is not shown in response to depression of the accelerator. After being converted into AC power by the inverter, it is supplied to the motor 12. As a result, the motor 12 is driven, the driving force is transmitted to the wheels 5a and 5b, and the vehicle shifts to a normal traveling state.

<Modification>
In the above-described embodiment, when the vehicle is decelerating, when the vehicle is in a regenerative braking state, the aerodynamic brake driving device 22 is operated, and the regenerative current is supplied only to the heating resistor 21 in the aerodynamic brake. Although regenerative power is consumed, control for processing surplus regenerative power is not limited to this.

  FIG. 4 is a block diagram illustrating an overall configuration of a braking device according to a modification of the above-described embodiment. In FIG. 4, the same components as those in the brake device according to the embodiment shown in FIG. In the braking device 11 according to the modification shown in FIG. 4, when the battery 30 is fully charged and the ECU 10 switches the power changeover switch 15 to the aerodynamic brake unit 20 side, the regenerative current from the motor 12 is generated in the aerodynamic brake. At the same time as the heating resistor 21 is energized, the aerodynamic brake drive device 22 is also energized. As a result, surplus regenerative power is consumed as heat in the aerodynamic brake heating resistor 21, and is also consumed as power for operating the aerodynamic brake drive device 22, enabling more efficient processing of surplus regenerative power. Become.

  In addition, although illustration etc. are abbreviate | omitted, according to the degree of regenerative braking, it may be made to consume surplus regenerative power by supplying electric power only to the heat generating resistor 21 in the aerodynamic brake without operating the aerodynamic brake. . Further, in the initial stage of regenerative braking, when a deceleration effect is obtained by operating only the aerodynamic brake by the aerodynamic brake drive device 22 and then regenerative braking is continued further, the regenerative current is generated in the aerodynamic brake heating resistor 21. May be configured to consume excess regenerative power.

Furthermore, in the embodiment described above, input from the battery state of charge determiner 33, based on the determination signal of the terminal voltage V of the battery 30, or the terminal voltage V of the battery 30 is lower than the threshold V _F, or as being determined based on a threshold value V _F above, directly by ECU 10, it may be configured to determine the state of charge of the battery.

  As described above, in the braking apparatus according to the present embodiment, the kinetic energy at the time of deceleration of the vehicle is not converted into heat by a normal friction brake, but is converted into electric energy by a regenerative brake, and the electric energy is converted into electric power. When charging the battery, only surplus regenerative power that cannot be fully charged in the battery is consumed as heat by the heating resistor provided in the aerodynamic brake unit. By doing so, the amount of energy converted into heat in the friction brake is reduced, and the brake capacity can be reduced accordingly. As a result, the brake can be made smaller and lighter when viewed as a whole brake system of the vehicle.

  Further, since the brake capacity is reduced, it is possible to reduce the amount of ventilation for cooling the brake in the wheel portion. Thereby, the air resistance of the vehicle accompanying ventilation (tire house ventilation) around a tire can be reduced. Furthermore, due to the deceleration effect of the vehicle by operating the aerodynamic brake, the regenerative power generated as surplus in the motor can be reduced, and the surplus regenerative power can be processed efficiently.

DESCRIPTION OF SYMBOLS 1 Braking device 5a, 5b Wheel 7 Power transmission part 10 ECU (electronic control unit)
DESCRIPTION OF SYMBOLS 12 Motor 15 Electric power changeover switch 20 Aerodynamic brake part 21 Heat generating resistor 22 in aerodynamic brake 22 Aerodynamic brake drive device 23 Hinge part 25 Flap 30 Battery 33 Battery charge state determination device 50

Claims (5)

A braking device that realizes deceleration of the vehicle by generating regenerative electric power using a drive motor of the vehicle as a generator during braking of the vehicle,
An aerodynamic brake installed at a predetermined position of the vehicle;
A heating resistor provided in the aerodynamic brake;
Battery charge state determination means for determining a state of charge of the battery during braking of the vehicle;
When it is determined by the battery charge state determination means that the battery is in a chargeable state, control is performed so that the battery is charged by the regenerative power, and the battery is fully charged by the battery charge state determination means. When it is determined that the battery is in a charged state, the aerodynamic brake is operated, and control means for controlling the regenerative power to be energized to the heating resistor;
A braking device comprising: When the battery charging state determination unit determines that the battery is in a fully charged state, the control unit is configured to supply the regenerative power to the heating resistor and the aerodynamic brake at the same time. The braking device according to claim 1 to be controlled. The braking device according to claim 1, wherein the aerodynamic brake includes a movable flap member, and the heating resistor is disposed so as to be exposed on a surface of the flap member. The braking device according to claim 1, wherein the aerodynamic brake includes a movable flap member, and the heating resistor is built in the flap member. The braking device according to claim 1 or 2, wherein the aerodynamic brake includes a movable flap member, the heating resistor is disposed on a surface of the flap member, and a protective coating is provided.

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