JP6018535B2 - Electric parking brake system - Google Patents

Description

  The present invention relates to an electric parking brake system.

  As a conventional electric parking brake system, for example, as described in Patent Document 1 below, a braking mechanism that brakes a vehicle, an actuator that drives the braking mechanism, and an actuator that operates when a predetermined start condition is satisfied. And a control unit that releases the braking state of the braking mechanism. In the electric parking brake system described in Patent Document 1, when it is determined by the inner camera that the occupant is not facing forward, the control unit changes the braking state of the braking mechanism even if a predetermined start condition is satisfied. It is configured not to release.

JP 2010-143542 A

  By the way, in the conventional electric parking brake system as described above, when a continuous operation is performed due to, for example, a driver's mischief or the like, the actuator or the control unit may generate heat and have a high temperature, which may cause adverse effects such as failure or deterioration of durability. There is.

  This invention is made | formed in view of such a situation, and makes it a subject to provide the electric parking brake system which can suppress the bad influence by heat_generation | fever.

  In order to solve the above problems, an electric parking brake system according to the present invention includes an electric parking brake device that applies a braking force to a vehicle by driving a parking brake mechanism by an actuator, and a control unit that controls the operation of the actuator. The control unit is characterized by prohibiting the operation of the actuator when the accumulated operation time of the actuator reaches a continuous operation possible time in a fixed time.

  In this electric parking brake system, the operation of the actuator is prohibited when the cumulative operation time of the actuator reaches the continuous operation possible time within a certain time. Therefore, when the continuous operation is performed, the actuator or the control unit can be prevented from generating heat, and as a result, it is possible to suppress adverse effects such as failure and durability deterioration due to the heat generation.

  Further, as a case where the above-described operation effect is suitably achieved, specifically, when the accumulated stop time of the actuator reaches a predetermined time, the control unit clears the accumulated operation time and the accumulated stop time, and the accumulated operation time continues. When the operable time is reached, the accumulated operation time and the accumulated stop time may be cleared and the operation of the actuator may be prohibited for a predetermined time.

  According to the present invention, adverse effects due to heat generation can be suppressed.

It is the schematic which shows the structure of the electric parking brake system which concerns on one Embodiment. It is a figure for demonstrating control of an actuator in the electric parking brake system of FIG. FIG. 8 is another diagram for explaining the control of the actuator in the electric parking brake system of FIG. 1.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are used for the same or corresponding elements, and duplicate descriptions are omitted.

  FIG. 1 is a schematic diagram illustrating a configuration of an electric parking brake system according to an embodiment. As shown in FIG. 1, an electric parking brake system 1 according to this embodiment is mounted on a vehicle V, and includes an electric parking brake device (Electronic Parking Brake) 10, a PKB operation lever 40, an ECU (Electronic Electronic Brake). Control Unit) 50.

  Examples of the vehicle V include large vehicles such as trucks, buses, and heavy machinery, and medium-sized vehicles. Further, the vehicle V to be applied is not limited, and may be a normal passenger car, a small vehicle, a light vehicle, or the like.

  The electric parking brake device 10 is an electric parking brake device for braking the vehicle V, and includes an actuator 11, a cable 12, and a PKB (Parking Brake: parking brake mechanism) 13. In the electric parking brake device 10, the actuator 11 is operated and the cable 12 is pulled with a predetermined pulling load, whereby the PKB 13 is driven and a desired braking force is applied to the wheel H of the vehicle V.

  The actuator 11 performs a pulling operation of the cable 12 and includes a motor and the like. The actuator 11 is electrically connected to the ECU 50, and the pulling load of the cable 12 is controlled by the ECU 50. The cable 12 is a brake wire connected to the actuator 11 and the PKB 13. In the illustrated example, the cable 12 extends from the actuator 11 forward between the driver seat D and the passenger seat P in the vehicle V, for example, and then bends so as to pass through the front side and the right side of the driver seat D. And is connected to the PKB 13.

  The PKB 13 employs a center brake drum brake or the like, and is installed behind the transmission 2. The PKB 13 presses the shoe against the drum, for example, according to the pulling of the cable 12, thereby restraining the propeller shaft 3. The PKB 13 is not limited in its configuration and method, and may be used as a service brake mechanism installed in the wheel H, or a parking brake mechanism different from the service brake mechanism may be used in the wheel H. It may be built-in. The PKB 13 may have an air brake mechanism that uses compressed air for its operation.

  The PKB operation lever 40 is for operating the electric parking brake device 10 and is electrically connected to the ECU 50. This PKB operation lever 40 operates the actuator 11 via the ECU 50 so that the electric parking brake device 10 is operated or released when the ON / OFF is switched by a driver, for example.

  The ECU 50 is a control unit that controls the operation of the actuator 11 in the electric parking brake device 10, and includes, for example, a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The ECU 50 prohibits the operation of the actuator 11 when the accumulated operation time of the actuator 11 reaches the continuous operation possible time in a certain time (details will be described later).

  In the electric parking brake system 1 configured as described above, for example, when the PKB operation lever 40 is operated and turned on by the driver, the actuator 11 is operated by the ECU 50, and the cable 12 is pulled by a predetermined pulling load. Thus, the PKB 13 is driven and a braking force is applied to the wheels H. Thereafter, when the PKB operation lever 40 is turned off, the actuator 11 is operated by the ECU 50, the pulling of the cable 12 is released, the driving of the PKB 13 is stopped, and the braking force is released.

  Here, in the ECU 50, as described below, when the accumulated operation time of the actuator 11 reaches the continuous operation possible time in a certain time, the operation of the actuator 11 is prohibited for the operation prohibition release time.

2 and 3 are diagrams for explaining the control of the actuator 11 in the electric parking brake system 1 of FIG. As shown in FIG. 2, the PKB operation lever 40 is continuously operated, for example, by a driver's mischief, and the operation accumulated time that is the accumulated value of the operation times dA, dB, dC, dD of the actuator 11 can be continuously operated for a certain time dT. When the time α is exceeded (see the following expression (1)), the actuator 11 is forcibly stopped.
dA + dB + dC + dD ≧ α (1)

In other words, the actuator 11 is forcibly stopped when the accumulated stop time that is the cumulative value of the stopped times da, db, and dc of the actuator 11 is smaller than the operation prohibition release time β at a certain time dT (see the following expression (2)). The
da + db + dc <β (2)

  Specifically, when the accumulated stop time of the actuator 11 (hereinafter simply referred to as “accumulated stop time”) reaches the operation prohibition release time β, the accumulated operation time of the actuator 11 (hereinafter simply referred to as “accumulated operation time”). And the accumulated stop time is cleared to zero. On the other hand, when the accumulated operation time reaches the continuous operation possible time α, the accumulated operation time and the accumulated stop time are cleared to 0 and the operation of the actuator 11 is prohibited.

That is, as illustrated in FIG. 3, even if the PKB operation lever 40 is continuously operated, when the accumulated stop time reaches the operation prohibition release time β (see time t ₀ ), the accumulated operation time and the accumulated stop time It is cleared to 0 and the operation limit is not yet applied. On the other hand, when the PKB operation lever 40 is continuously operated and the accumulated operation time reaches the continuously operable time α (see time t ₁ ), the accumulated operation time and the accumulated stop time are cleared and the actuator 11 is prohibited for the operation prohibition release time β.

  The continuous operation possible time α is a continuous operation time of the actuator 11 when, for example, the actuator 11 or the ECU 50 (internal drive IC) exceeds the guaranteed temperature, and is 22.4 sec as an example. The operation prohibition release time β is a predetermined time required for cooling the actuator 11 or the ECU 50, for example, and is 20 sec as an example.

  As described above, in the present embodiment, the operation of the actuator 11 is prohibited when the accumulated operation time of the actuator 11 reaches the continuous operation possible time α within a certain time. That is, when the ratio of the operation time for operating the electric parking brake device 10 and the release time for releasing the electric parking brake device 10 exceeds the reference time within a certain time, the actuator 11 is restricted from operating. Therefore, even when the PKB operation lever 40 is continuously operated by the driver's mischief, it is possible to suppress the actuator 11 or the ECU 50 from generating heat and increasing the temperature, and as a result, it is possible to suppress adverse effects such as failure and durability deterioration due to the heat generation. It becomes possible to do.

  Although it is conceivable that the operation of the actuator 11 is limited based on the number of operations, in this case, there is an excessive margin for heat generation, and the operation may be easily limited. In this respect, the present embodiment is effective with less concern.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments. The present invention can be modified without departing from the scope described in the claims or applied to other embodiments. May be. For example, the continuous operation possible time α and the operation prohibition release time β are not limited to the above, and various values may be adopted according to the specifications, ambient conditions, and the like.

  DESCRIPTION OF SYMBOLS 1 ... Electric parking brake system, 10 ... Electric parking brake apparatus, 11 ... Actuator, 13 ... PKB (parking brake mechanism), 50 ... ECU (control part), V ... Vehicle.

Claims (2)

An electric parking brake device that applies a braking force to the vehicle by driving a parking brake mechanism by an actuator; and
A control unit for controlling the operation of the actuator,
The said control part prohibits operation | movement of the said actuator, when the operation | movement accumulation time of the said actuator reaches | attains continuous operation possible time in fixed time, The electric parking brake system characterized by the above-mentioned. The controller is
When the accumulated stop time of the actuator reaches a predetermined time, clear the accumulated operation time and the accumulated stop time,
2. The electric parking brake system according to claim 1, wherein when the operation accumulated time reaches the continuous operation possible time, the operation accumulated time and the stop accumulated time are cleared, and the operation of the actuator is prohibited for the predetermined time.

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