JP2005081963A - Electric parking brake system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of applying a braking force smaller than the maximum braking force to a wheel at a normal time and applying a braking force larger than the braking force in the normal time to the wheel at a required time, in an electric parking brake system comprising a parking brake mechanism for applying the braking force to the wheel by an operation of an actuator, an operating switch for switching the parking brake mechanism between a braking state and a braking released state, and a control means for controlling a braking operation of the parking brake mechanism by an actuator in response to the operation of the operating switch. <P>SOLUTION: A parking brake body and the operating switch are connected to an electric parking brake controller. When the operating switch is pulled only once, 70% load is charged on the wheel. When an increase/decrease condition is established after the 70% load is charged by pulling the operating switch only once, 100% load is charged on the wheel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a parking brake mechanism that applies a braking force to a wheel by operating an actuator, an operation switch for switching the parking brake mechanism between a braking state and a braking release state, and an operation of the operation switch. The present invention relates to an electric parking brake system including control means for controlling a braking operation of the parking brake mechanism by the actuator.

Conventionally, an electric parking brake is known as one of parking brakes (see, for example, Patent Document 1). The electric parking brake includes an electric motor that operates in response to a switch operation by a driver, and a parking brake mechanism that applies a braking force to the wheels by the operation of the electric motor.
Japanese Utility Model Publication No. 64-26569

  By the way, as one method for reliably parking and stopping a vehicle using an electric parking brake, it is conceivable to apply a maximum braking force for each parking and stopping. However, in this case, the durability of each part (for example, cable, base brake, etc.) of the parking brake mechanism may be adversely affected, and the reliability of the electric parking brake may be impaired. Furthermore, in the above-described case, the time required for setting the parking brake mechanism to the braking state or the braking release state becomes long. In particular, if the time for putting the parking brake mechanism in the brake release state becomes long, it may cause dragging, shock, jumping out, etc. of the parking brake mechanism. From the above viewpoint, it is preferable to apply a braking force smaller than the maximum braking force when parking and stopping.

  On the other hand, for example, when a vehicle is parked and stopped on a steep slope, there is a possibility that the vehicle cannot be parked and stopped with a braking force smaller than the maximum braking force as described above.

  Therefore, the present inventors apply a braking force smaller than the maximum braking force in the normal state, while, when necessary (for example, when the vehicle parks and stops on a steep slope), the braking force in the normal state. We have developed a technology that gives a large braking force.

  The present invention has been made in view of such points, and an object of the present invention is to provide a parking brake mechanism that applies a braking force to a wheel by the operation of an actuator, a braking state and a brake release of the parking brake mechanism. In an electric parking brake system comprising an operation switch for switching to a state, and a control means for controlling the braking operation of the parking brake mechanism by the actuator in accordance with the operation of the operation switch, An object of the present invention is to provide a technique for applying a small braking force to a wheel while applying a braking force larger than a normal braking force when necessary.

  According to a first aspect of the present invention, there is provided a parking brake mechanism that applies a braking force to a wheel by operating an actuator, an operation switch for switching the parking brake mechanism between a braking state and a braking release state, and an operation of the operation switch. And a control means for controlling the braking operation of the parking brake mechanism by the actuator in response to determining whether or not the vehicle is moving or is likely to move. The control means applies a first braking force smaller than the maximum braking force to the wheel when the operation switch is braked, and the first braking force is applied to the wheel. The determination means determines that the vehicle is moving or that the vehicle is likely to move. If the is characterized in that the second braking force greater than the first braking force is configured to impart to said wheel.

  Thereby, a control means gives the 1st braking force smaller than a maximum braking force with respect to a wheel, when an operation switch is brake-operated. That is, at the normal time, a braking force smaller than the maximum braking force is applied to the wheels. In addition, when the determination unit determines that the vehicle is moving or is about to move after the first braking force is applied to the wheels, the control unit performs the first control. A second braking force larger than the power is applied to the wheel. In other words, when it is determined that the vehicle is moving or the vehicle is likely to move even though the braking force is applied to the wheels in the normal state, the braking force is greater than that in the normal state. Power is applied to the wheels. Therefore, a braking force smaller than the maximum braking force can be applied to the wheel at the normal time, while a braking force larger than the braking force at the normal time can be applied to the wheel when necessary.

  According to a second aspect of the present invention, in the first aspect of the invention, the vehicle includes an accelerator detection unit that detects an accelerator operation and a movement detection unit that detects that the vehicle is moving. The determination unit includes the accelerator detection unit. When the accelerator operation is not detected and the movement detection means detects that the vehicle is moving, the vehicle is determined to be in a moving state. Is.

  Here, when the accelerator operation is not detected by the accelerator detection means and the movement detection means detects that the vehicle is moving, for example, the vehicle moves even though it does not intend to move the vehicle. When you are.

  Thereby, the determination criteria of the determination means can be embodied.

  According to a third aspect of the present invention, in the first aspect of the invention, there is provided idle-up detection means for detecting that the engine is idle up or that the engine is likely to idle up. Configured to determine that the vehicle is moving or that the vehicle is likely to move when it is detected that the engine is idle or is likely to idle It is characterized by.

  Thereby, the determination criteria of the determination means can be embodied.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the vehicle includes a rear-end collision detection unit that detects whether the vehicle has collided or is about to collide, and the determination unit includes the rear-end collision detection unit. It is configured to determine that the vehicle is moving or that the vehicle is likely to move when it is detected that the vehicle has been made or the vehicle is likely to be collided. is there.

  Thereby, the determination criteria of the determination means can be embodied.

  According to a fifth invention, in the first invention, there is provided brake detecting means for detecting a state of a brake pedal, and the determination means detects that the depressed brake pedal is further depressed by the brake detecting means. When it is done, it is determined that the vehicle is in a moving state or a state in which the vehicle is likely to move.

  Here, when it is detected by the brake detection means that the depressed brake pedal is further depressed, for example, the vehicle does not stop although it is attempted to stop the vehicle by depressing the brake pedal. Is the time.

  Thereby, the determination criteria of the determination means can be embodied.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, the brake detection means for detecting the state of the brake pedal is provided, and the determination means is configured to detect the brake pedal after the brake pedal that has been depressed returns to the normal position. When it is detected that the brake pedal is depressed again, the vehicle is determined to be in a moving state or a state where the vehicle is likely to move.

  Here, when it is detected that the brake pedal is depressed again after the depressed brake pedal returns to the normal position, for example, the vehicle is stopped by depressing the brake pedal. This is when the vehicle starts moving again later.

  Thereby, the determination criteria of the determination means can be embodied.

  According to the present invention, a braking force smaller than the maximum braking force can be applied to the wheel at the normal time, while a braking force larger than the braking force at the normal time can be applied to the wheel when necessary. Therefore, the electric parking brake system can be reduced in weight and the burden on the electric parking brake system can be reduced, and the vehicle can be surely parked and stopped not only during normal times but also when necessary.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a vehicle (automobile) 1 includes an instrument panel (hereinafter referred to as an instrument panel) 2 extending in the vehicle width direction, a steering wheel 3 projecting from the instrument panel 2 toward the rear of the vehicle, and an instrument panel. 2 is provided with a shift lever 4 of a transmission installed at the center in the vehicle width direction behind the vehicle, and an electric parking brake system 10 (not shown in FIG. 1 (see FIG. 2)). The instrument panel 2 contains a display device (not shown) for notifying the driver of the fact that the electric parking brake control device 50 (see FIG. 2) is in the later-described dynamic parking control. Has been.

  As shown in FIG. 2, the electric parking brake system 10 according to the embodiment of the present invention includes a vehicle-side control device 30 that controls various vehicle components, and a parking by an electric motor 52 a according to an operation of an operation switch 53. And an electric parking brake control device 50 that controls the braking operation of the brake mechanism (the operation switch 53, the electric motor 52a, and the parking brake mechanism will be described later). Note that the control means and determination means in the present invention correspond to the electric parking brake control device 50.

  The vehicle-side control device 30 includes a battery 31, a shift position switch 32, a vehicle speed sensor 33, a brake switch 34, an accelerator opening sensor 35, an airbag ultrasonic sensor 36, an idle up sensor 37, a green indicator lamp 38, and a red indicator. A lamp 39 is connected, and a vehicle-side CAN (Controller Area Network) 40 is incorporated. In the present invention, the accelerator detection means corresponds to the accelerator opening sensor 35, the movement detection means corresponds to the vehicle speed sensor 33, the idle up detection means corresponds to the idle up sensor 37, and the rear-end collision detection means corresponds to the air detection sensor. Corresponding to the ultrasonic sensor 36 for bags, the brake detection means corresponds to the brake switch 34.

  When the shift lever 4 of the transmission is in the parking state (P state), the shift position switch 32 transmits a P range signal as a shift position signal to the vehicle-side control device 30, while the shift lever 4 is neutral. When in the state (N state), an N range signal is transmitted to the vehicle-side control device 30 as a shift position signal.

  The vehicle speed sensor 33 detects the vehicle speed and transmits a vehicle speed signal having the detected vehicle speed information to the vehicle-side control device 30. The brake switch 34 transmits a brake switch signal (brake SW signal) to the vehicle control device 30 when the driver depresses the brake pedal. The accelerator opening sensor 35 detects the accelerator opening and transmits an accelerator opening signal having the detected accelerator opening information to the vehicle-side control device 30.

  The airbag ultrasonic sensors 36 are attached to the front, rear, left, and right corners of the vehicle 1 to detect a rear-end collision state and transmit a rear-end collision signal having information on the detected rear-end collision state to the vehicle-side control device 30. To do. Here, the rear-end collision state refers to a state in which the vehicle 1 is collided with another vehicle or a state in which the vehicle 1 is likely to collide with another vehicle. The idle up sensor 37 detects an idle up state and transmits an idle up signal having information on the detected idle up state to the vehicle-side control device 30. Here, the idle-up state refers to a state where the engine is idle up or a state where the engine is likely to idle up.

  Green and red indicator lamps 38 and 39 are housed in the instrument panel 2. When the parking brake mechanism applies a 70% load to the wheel (70% load will be described later), the green indicator lamp 38 is lit by the control of the vehicle-side control device 30, while the wheel is turned on. On the other hand, when a 100% load (100% load will be described later) is applied, the green and red indicator lamps 38 and 39 are turned on.

  The vehicle-side CAN 40 transmits each signal (shift position signal, vehicle speed signal, brake switch signal, accelerator opening signal, rear-end collision signal, and idle up signal) received by the vehicle-side control device 30 to a brake-side CAN 57 described later. .

  The electric parking brake control device 50 is connected to a battery 51, a parking brake main body 52, an operation switch 53, a position sensor 54, a yellow warning lamp 55 and a red warning lamp 56, and a built-in brake side CAN 57. Yes.

  The parking brake main body 52 has an electric motor 52a that operates under the control of the electric parking brake control device 50, and a parking brake mechanism (not shown) that applies braking force to the wheels by the operation of the electric motor 52a. doing. The actuator referred to in the present invention corresponds to the electric motor 52a.

  As shown in FIG. 1, the operation switch 53 is installed on the right side of the shift lever 4. The operation switch 53 is for switching the parking brake mechanism between an operating state (braking state) and a releasing state (braking release state), and is composed of a single momentary switch (seesaw switch) as shown in FIG. Here, the momentary switch is a switch that switches the parking brake mechanism between an activated state and a released state by pushing (pulling) one side of a knob or the like that performs a seesaw operation. The operation switch 53 is configured to be switchable between an operation state (braking state), a neutral state, and a release state (braking release state) (see FIG. 3). When the application of force to the operation switch 53 is stopped after the operation switch 53 is switched to the activated state or the released state, the state automatically returns to the neutral state. Further, the operation switch 53 functions as a switch for starting the operation of the normal control when the normal control is operated, and functions as a switch for starting the operation of the dynamic parking control when the dynamic parking control (dynamic PA control) is operated. . Here, normal control is control for causing the parking brake mechanism to function as a general parking brake, and dynamic parking control is control for causing the parking brake mechanism to function like a foot brake.

  Hereinafter, an operation method of the operation switch 53 during normal control and dynamic parking control will be described.

-Normal control-
(Manual operation)
When the driver pulls the operation switch 53 only once during normal control (when the driver switches the operation switch 53 to the activated state only once), the operation switch 53 is switched to the electric parking brake control device 50. When the electric parking brake control device 50 transmits a 70% load signal to the vehicle and receives the signal, the parking brake mechanism has a braking force equivalent to 70% of the maximum braking force (hereinafter referred to as “70% of the maximum braking force”). The electric motor 52a is controlled so as to apply a braking force corresponding to “70% load” to the wheels. The 70% load is a load that can park and stop the vehicle 1 with a 20% gradient. The “braking operation of the operation switch” referred to in the present invention corresponds to an operation of pulling the operation switch 53 only once, and the first braking force corresponds to 70% load.

  When the driver pulls the operation switch 53 only twice during normal control, the operation switch 53 transmits a 100% load signal to the electric parking brake control device 50 and receives the signal. The parking brake control device 50 applies a braking force corresponding to 100% of the maximum braking force (hereinafter, “braking force corresponding to 100% of the maximum braking force” is referred to as “100% load”) to the wheels. .

  In the normal control, when the driver pulls the operation switch 53 only once and a 70% load is applied to the wheel and then the additional pulling condition is satisfied, the electric parking brake control device 50 Applies a braking force greater than 70% load (in this embodiment, for example, 100% load) to the wheel. Here, the case where the additional pulling condition is satisfied is a case where the electric parking brake control device 50 determines that the vehicle 1 is moving or is about to move (the additional pulling condition). Will be described later in detail). The second braking force referred to in the present invention corresponds to 100% load.

(Manual release)
When the manual release condition is satisfied during normal control, the operation switch 53 transmits a release signal to the electric parking brake control device 50, and the electric parking brake control device 50 that has received the signal performs braking on the wheels. To release. Here, when the manual release condition is satisfied, the driver presses the operation switch 53 (in other words, the driver switches the operation switch 53 to the release state) and depresses the brake pedal or the accelerator pedal. Is the case. The “operation switch brake release operation” in the present invention corresponds to an operation of pressing the operation switch 53.

(Auto (Auto) cancellation)
When the parking brake mechanism is in an activated state and the driver pulls the operation switch 53, the electric parking brake control device 50 enters an auto release standby state. When it is in the auto-release standby state and the auto-release condition is satisfied, the electric parking brake control device 50 releases the braking of the wheel. Here, the case where the automatic release condition is satisfied means that the driver depresses the accelerator pedal or the brake pedal between the time of entering the automatic release standby state and the elapse of the preset first predetermined time. It is. That is, in this automatic release, there is no need to operate the operation switch 53 after entering the automatic release standby state.

-Dynamic parking control-
(Operation)
When the driver pulls the operation switch 53 during the dynamic parking control, the operation switch 53 transmits a load signal to the electric parking brake control device 50, and the electric parking brake control device 50 that has received the signal receives the load signal. A braking force corresponding to the vehicle speed (details of this braking force will be described later) is applied to the wheels. When the vehicle 1 stops due to the braking force corresponding to the vehicle speed being applied, even if the operation switch 53 returns to the neutral state by removing the finger from the operation switch 53, the electric parking The brake control device 50 prohibits the release of wheel braking and maintains wheel braking.

  Here, the load applied to the wheels during dynamic parking control will be described in detail. The load at the time of dynamic parking control is proportional to the time when the operation switch 53 is pulled. In addition, an upper limit load corresponding to the vehicle speed is set as the load at the time of dynamic parking control so that the wheel does not lock on a high μ road. Specifically, as shown in FIG. 4, the upper limit load decreases as the vehicle speed increases. Further, the time required for the load during dynamic parking control to reach the upper limit load (hereinafter, “time until the load during dynamic parking control reaches the upper limit load” is referred to as “upper limit load arrival time”) is shown in FIG. Is set to That is, the upper limit load arrival time becomes shorter as the upper limit load becomes larger, and becomes shorter when the vehicle 1 is traveling on a downward slope than when it is normal (when the vehicle 1 is traveling flat). . Further, the rate of increase in load at the start of dynamic parking control varies depending on the vehicle speed in order to prevent shock. Specifically, as shown in FIG. 6, the rate of increase in load at the start of dynamic parking control is greater at a high vehicle speed than at a low vehicle speed.

(Release)
The driver presses the operation switch 53 between the time when the braking of the wheel is held by the dynamic parking control and the elapse of a preset second predetermined time (for example, 5 seconds in this embodiment). In this case, the operation switch 53 transmits a release signal to the electric parking brake control device 50, and the electric parking brake control device 50 that receives the signal releases the braking held immediately after the reception.

  In addition, when 5 seconds have passed since the braking of the wheels has been maintained, the dynamic parking control is finished and the normal control is started. The operation method of the operation switch 53 has been described so far.

  As shown in FIG. 2, the position sensor 54 detects the position of the rotating shaft of the electric motor 52 a and transmits a position signal having the detected position information to the electric parking brake control device 50. The yellow and red warning lamps 55 and 56 are housed in the instrument panel 2. When the parking brake mechanism applies a braking load to the wheels, the electric parking brake control device 50 lights both the warning lamps 55 and 56. The brake side CAN 57 transmits a parking brake state signal having information on the state of the parking brake mechanism to the vehicle side CAN. The parking brake state signal includes a 70% load operation signal, a 100% load operation signal, and a release signal.

-Control procedure of braking operation by electric parking brake control device-
Below, the control procedure of the braking operation by the electric parking brake control device 50 will be described with reference to the flowcharts of FIGS. Note that F = 0 described below means brake release (braking release), F = 1 means normal control, and F = 2 means dynamic parking control.

  First, as shown in FIG. 7, it is determined in step S1 whether or not the flag is F = 0. If the determination result in step S1 is YES, the process proceeds to step S2 to determine whether or not the operation switch 53 is in a neutral state or a released state. If the determination result in step S2 is YES, the process proceeds to step S3 to release the brake. Then return to the start.

  If the determination result in step S2 is NO, the process proceeds to step S4 to determine whether or not the vehicle speed is 5 km / h or more. If the determination result in step S4 is YES, the process proceeds to step S5, and it is determined whether or not the operation switch 53 is in an activated state. If the determination result in step S5 is NO, the process proceeds to step S3 to release the brake.

  If the determination result in step S5 is YES, the process proceeds to step S6, and it is determined whether or not the vehicle 1 is turning or the accelerator is in an ON state (a state where the accelerator is depressed). If the determination result in step S6 is YES, the process proceeds to step S3 to release the brake, while if the determination result in step S6 is NO, the process proceeds to step S7 to perform dynamic parking control ( Details of the control procedure of the dynamic parking control will be described later).

  If the determination result in step S4 is NO, the process proceeds to step S8 and normal control is performed. Next, it progresses to step S9 and it is determined whether the manual cancellation | release conditions are satisfied. If the determination result in step S9 is YES, the process proceeds to step S3 to release the brake.

  If the determination result in step S9 is NO, the process proceeds to step S10, and is the number of times that the driver pulled the operation switch 53 the first time (the first time that the operation switch 53 is switched to the operating state)? Determine whether or not. If the decision result in the step S10 is YES, the process proceeds to a step S11 to perform a 70% load braking. Next, the process proceeds to step S12, and it is determined whether or not the additional discount condition is satisfied (details of the determination procedure of whether or not this additional condition is satisfied will be described later). If the decision result in the step S12 is YES, the process proceeds to a step S13 to perform 100% load braking. Next, it progresses to step S14 and it is determined whether the auto cancellation | release conditions are satisfied. If the determination result in step S14 is YES, the process proceeds to step S3 to release the brake, while if the determination result in step S14 is NO, the process returns to the start.

  If the determination result in step S10 is NO, the process proceeds to step S15 to determine whether or not the number of times the driver has pulled the operation switch 53 is the second time. If the decision result in the step S15 is YES, the process proceeds to a step S13 to perform 100% load braking.

  If the determination result in step S12 or step S15 is NO, the process proceeds to step S14, and it is determined whether or not an automatic release condition is satisfied.

  If the determination result in step S1 is NO, the process proceeds to step S16 to determine whether or not the flag is F = 1. If the determination result in step S16 is YES, the process proceeds to step S8 and normal control is performed.

  If the determination result in step S16 is NO, the process proceeds to step S17 to determine whether or not the flag is F = 2. If the determination result in step S17 is YES, the process proceeds to step S18 to perform dynamic parking control, while if the determination result in step S17 is NO, the process returns to the start.

(Control procedure for dynamic parking control)
First, as shown in FIG. 8, the electric parking brake control device 50 displays that the dynamic parking control is being performed (the flag is F = 2) on the display device of the instrument panel 2.

  Next, it progresses to step S20 and it is determined whether the frequency | count that the driver pulled the operation switch 53 is the first time. Here, the determination of “whether or not the number of times the operation switch 53 has been pulled is the first time” is based on whether or not the elapsed time from the previous pulling of the operation switch 53 to the current pulling is equal to or longer than the set time. Done. If the elapsed time is equal to or longer than the set time, it is determined that the number of times the operation switch 53 has been pulled is the first time. If the decision result in the step S20 is YES, the process advances to a step S21 to decide whether or not the operation for pulling the operation switch 53 is a continuous operation. Specifically, it is determined whether or not the pulling operation has continued for 1 second or longer. If the decision result in the step S21 is YES, the process proceeds to a step S22 so as to apply a braking force corresponding to the vehicle speed to the wheels (see FIGS. 4 to 6).

  Next, it progresses to step S23 and it is determined whether the vehicle has stopped. If the determination result in step S23 is YES, the process proceeds to step S24, and even when the operation switch 53 is in the neutral state, the brake release is prohibited and braking (for example, braking with 70% load) is maintained. Next, it progresses to step S25 and it is determined whether the elapsed time after braking was hold | maintained is 2nd predetermined time, ie, 5 second or more. If the determination result in step S25 is YES, the process proceeds to step S26, and the flag is changed from F = 2 to F = 1. And dynamic parking control is complete | finished and normal control is started (step S27). Then return to the start.

  If the determination result in step S25 is NO, the process proceeds to step S28 to determine whether or not the operation switch 53 is in the released state. If the decision result in the step S28 is YES, the process advances to a step S29 to release the braking force by releasing the brake, and then returns to the start. On the other hand, if the decision result in the step S28 is NO, the process returns to the step S25.

  If the determination result in step S20 is NO, that is, if the operation switch 53 is pulled more than once, the process proceeds to step S22, and a braking force corresponding to the vehicle speed is applied to the wheel. (See FIGS. 4-6). When the operation switch 53 is pulled more than once, unlike the case where the operation switch 53 is pulled the first time, the braking force starts to be applied immediately after the braking operation of the operation switch 53.

  If the determination result in step S23 is NO, the process proceeds to step S30 to determine whether or not the operation switch 53 is in a neutral state. If the determination result in step S30 is YES, the process proceeds to step S29, and the braking force is released by releasing the brake. On the other hand, if the determination result in step S30 is NO, the process proceeds to step S22 and the vehicle speed is increased. A corresponding braking force is applied to the wheel (see FIGS. 4 to 6).

  If the determination result in step S21 is NO, the process proceeds to step S31, where the braking operation of the operation switch 53 is determined to be an erroneous operation, and the flag becomes F = 0. Then return to the start.

(Judgment procedure of whether or not the extra discount condition is satisfied)
First, as shown in FIG. 9, it is determined in step S40 whether or not the engine is in the idle-up state based on the idle-up signal. If the determination result in step S40 is YES, the process proceeds to step S41, and it is determined that the additional discount condition is satisfied.

  When the determination result in step S40 is NO, the process proceeds to step S42, and it is determined whether or not the rear-end collision state is based on the rear-end collision signal. If the determination result in step S42 is YES, the process proceeds to step S41, and it is determined that the additional pulling condition is satisfied.

  If the determination result in step S42 is NO, the process proceeds to step S43, and it is determined whether or not the brake is depressed based on the brake switch signal. Here, the brake depression state is a state where the depressed brake pedal is further depressed or a state where the depressed brake pedal is depressed again after returning to the normal position. If the determination result in step S43 is YES, the process proceeds to step S41, and it is determined that the extra pull condition is satisfied.

  If the determination result in step S43 is NO, the process proceeds to step S44, and it is determined whether or not the accelerator is in an ON state based on the accelerator opening signal. If the determination result in step S44 is NO, the process proceeds to step S45 to determine whether or not the vehicle 1 is moving based on the vehicle speed signal. If the determination result in step S45 is YES, the process proceeds to step S41, and it is determined that the additional pulling condition is satisfied.

  If the determination result in step S44 is YES or if the determination result in step S45 is NO, the process proceeds to step S46, and it is determined that the increase / decrease condition is not satisfied.

-Effect-
As described above, according to the present embodiment, when the driver pulls the operation switch 53 only once during normal control, a 70% load is applied to the wheel. That is, during normal times, a 70% load smaller than the maximum braking force is applied to the wheels. In addition, during normal control, when the driver pulls the operation switch 53 only once and a 70% load is applied to the wheel and then the additional pulling condition is satisfied, the 100% load is applied to the wheel. To grant. That is, when it is determined that the vehicle 1 is moving or the vehicle 1 is likely to move despite the 70% load being applied to the wheels, it is greater than the 70% load. A 100% load is applied to the wheel. Therefore, a load smaller than the maximum braking force can be applied to the wheel at the normal time, while a load larger than the load at the normal time can be applied to the wheel when necessary. As a result, the electric parking brake system 10 can be reduced in weight and the burden on the electric parking brake system 10 can be reduced, and the vehicle 1 can be surely parked and stopped not only during normal times but also when necessary. it can.

(Other embodiments)
In this embodiment, the operation switch 53 includes a push-pull operation switch (see FIG. 3) that can be switched between an operation state, a neutral state, and a release state. However, as shown in FIG. A pulling operation switch that can be switched between an auto release state and a neutral state may be used. At this time, the pulling operation switch is switched between an operation state, a release state, and an automatic release state according to the time when the driver pulls the pulling operation switch.

  Further, in this embodiment, the operation switch 53 is composed of a single momentary switch. However, the switch for setting the parking brake mechanism to the operating state, the switch for setting the auto release standby state, the switch for setting the neutral state, A switch may be provided separately for the release state.

-Further problems of electric parking brake system and means for solving the problems-
Below, the further subject of this electric parking brake system 10 and the means (structure) for solving the subject are described.

<Control>
(full automatic)
(1) Flat road When the vehicle is on a flat road, the braking load is set by the number of operations of the operation switch 53 (for example, 70% load when the number of operations is the first time, second case 100% load). Further, the braking load may be set by the operation time of the operation switch 53 (for example, 70% load when the operation time is less than 0.5 seconds, 100% load when the operation time is 0.5 seconds or more) ).

(2) Slope (i) Appropriate braking force on a slope To apply an appropriate braking force on a slope, the braking load is changed according to the inclination angle. However, the following correction is performed.

(Correction 1) Engine idle-up correction (starting, air conditioner, electric load, power steering, defogger, etc.)
When the vehicle 1 is stopped and the shift lever 4 is in the N range, the basic load setting in which the braking force is set according to the inclination angle may be used, but the vehicle 1 is stopped and the shift is performed. When the lever 4 is in the travel range, the braking load is increased according to the increased amount of engine rotation.

(Correction 2) Correction according to the tilt angle and the shift position (forward range, reverse range) When the vehicle 1 is in the downward gradient and the shift lever 4 is in the forward range and when the vehicle 1 is in the upward gradient When the shift lever 4 is in the reverse range, the load is increased. On the other hand, when the vehicle 1 is in the upward slope and the shift lever 4 is in the forward range, and when the vehicle 1 is in the downward slope and the shift lever 4 is in the reverse range, the load is reduced.

  In order to apply an appropriate braking force on a slope, the braking load may be set based on the braking pressure when the vehicle is stopped (when the vehicle speed is 0 km / h).

(Ii) Release timing on a hill road When the vehicle 1 is on an uphill and the shift lever 4 is in the forward range, and when the vehicle 1 is on the downhill and the shift lever 4 is in the reverse range, Perform automatic release (auto release) by accelerator operation. On the other hand, when the vehicle 1 is on the uphill and the shift lever 4 is in the reverse range and when the vehicle 1 is on the downhill and the shift lever 4 is in the forward range, the brake pedal is turned off. The automatic release is performed.

(3) Preventing accidents (i) Preventing popping out The electric parking brake system 10 does not perform automatic release only by the accelerator operation, but operates the operation switch 53, that is, the accelerator operation is based on the assumption that the driver intends to start. The automatic release is performed by. Specifically, when the parking brake mechanism is in operation, when the vehicle 1 moves due to an unexpected accelerator operation, the retraction is automatically performed. In addition, when an accelerator operation is input, an additional discount is automatically performed. Further, when the engine is idling up, it is automatically increased or decreased.

(Ii) Countermeasures against obstacles An obstacle is detected by a radar, a CCD camera, an ultrasonic sensor, or the like. When an obstacle is detected, automatic release is prohibited and an alarm is issued.

(4) Automatic release of MT vehicle (i) Clutch meet is detected and released. Specifically, the clutch meet position (stroke) is set in advance according to the accelerator opening (engine speed) at the time of start, and the braking force is released. Further, the clutch meet at the time of starting is judged from the pitch (G sensor) of the vehicle 1 and the braking force is released. Also, the release speed of the clutch (decrease in engine speed) is detected to release the braking force faster. Further, the engine speed and the slip rate of the vehicle speed (T / M) are detected to release the braking force.

(Ii) Countermeasure for engine stall, etc. When engine stall is detected, automatic operation is performed (preventing reverse running on slopes).

  In addition, an engine stall is predicted and automatic release is prohibited. The case where the engine stall is predicted is a case where the accelerator pedal is not depressed and a clutch meet operation is performed or an accelerator operation is not performed before the clutch meet. Further, when the engine stall is predicted, control of the throttle is added (corrected by the electric throttle).

  Further, when the vehicle 1 is on a downhill, the accelerator is hardly opened at the time of clutch meet. Therefore, there is a possibility that engine stall occurs when the braking force is released slowly. Therefore, when the vehicle 1 is on a downhill, the braking force is released faster (depressurization gradient). When a clutch operation is input, release of the braking force is started (release of the braking force before the clutch meet). In addition, when the foot is released from the brake pedal, the braking force is released (starting operation using the slope inertia).

(Activation / cancellation conditions for manual operation of operation switches)
Release is prohibited when the door is open, the trunk is open, the bonnet is open, or the seat belt is not attached.

(Dynamic parking control)
(1) Actuation / cancellation conditions in dynamic parking control (i) High μ road When the parking brake mechanism is operated during traveling, control is basically performed so as not to lock the wheels. Specifically, the operation is performed when the operation switch 53 is continuously braked for a predetermined time. In order to prevent erroneous operation, it does not operate in a short braking operation. Further, when the hand is released from the operation switch 53, it is released immediately.

  In order to prevent the wheels from being locked, an upper limit load is set according to the vehicle speed. When the operation switch 53 is continuously braked, the braking force increases up to the upper limit load at a constant increase rate.

  Also, when the accelerator is depressed during operation, it is released. Furthermore, it does not operate when the operation switch 53 is braked during the accelerator operation.

  In the first braking operation of the operation switch 53, in order to perform deceleration control, the operation is performed after a certain time has elapsed after the operation, while in the second and subsequent braking operations, braking is started immediately after the operation. (Hereinafter, “starting braking immediately after operation” is referred to as immediate start of switch operation). This is because the deceleration control cannot be performed if the operation is performed after a certain time has passed. Further, when the next braking operation of the operation switch 53 is not performed within a certain time (for example, within 2 seconds) after the previous braking operation, the switch operation immediate start is reset. Even when the vehicle 1 stops, the switch operation immediate start is reset.

  Further, when the vehicle 1 is stopped by the dynamic parking control (when the vehicle speed is 5 km / h or less), the braking force is maintained even when the operation switch 53 is released (switching to the stop control).

(Ii) Low μ road correction A lock signal is received from the ABS unit, and control by the motor is performed. An ABS lock signal is put into the control loop, and ABS control by the motor is performed by ON / OFF control of the motor. When an ABS lock signal is input, the motor is released until the lock is released, and then the unlocking braking force is maintained.

  It also receives μ estimates from ABS. At this time, the upper limit load is set for the low μ road and the pressure increasing gradient of the braking force load is made smooth (that is, slower than the high μ road). Since the ABS μ estimation cannot be performed unless the ABS is activated, a time difference occurs.

  In addition, μ estimation is performed indirectly (outside temperature, wiper operating state, wheel slip, etc.). At this time, the upper limit load is set for the low μ road, and the pressure increasing gradient of the braking load is made smooth (slower than the high μ road). Although this indirect μ estimation is inaccurate but direct, there is no time difference.

(2) Prevention of erroneous operation in dynamic parking control (i) Operation prohibition When the brake operation time of the operation switch 53 is short, the operation is not started. Also, the operation is prohibited when the accelerator is being operated.

(Ii) Prevention of sudden braking When the vehicle is traveling at a corner (steering angle), the parking brake mechanism is inhibited from being increased in pressure and the braking force up to that point is maintained. In addition, when the vehicle is traveling in a corner, the start of operation is prohibited. Moreover, it respond | corresponds with a logic so that it may not detect that a vehicle speed is 0 km / h by a vehicle speed lock. Specifically, when a sudden change (1G or more) in the vehicle speed is detected, the stop logic is not entered.

(Other)
Automatic operation when the key is removed. Also, when the operation switch 53 is in the release state and the key is removed, automatic release is prohibited.

<Display>
At the time of automatic release standby, the indicator lamps 38 and 39 are blinked. Note that the accelerator can be released when flashing. When a certain time has passed after the blinking, the blinking indicator lamps 38 and 39 are turned on. The accelerator cannot be released after lighting. Specifically, when the operation switch 53 is pulled only once, the green indicator lamp 38 is lit, while when the automatic release standby state is thereafter entered, the green indicator lamp 38 flashes. Further, when the operation switch 53 is pulled only twice, the green and red indicator lamps 38 and 39 are turned on. On the other hand, when the automatic release standby state is set thereafter, the green and red indicator lamps 38 and 39 blink. To do.

<Automatic operation on slopes>
(1) When the vehicle cannot be stopped due to creep of the AT car, automatic operation is performed. Specifically, when the vehicle 1 is on the uphill and the shift lever 4 is in the travel range and when the vehicle 1 is on the downhill and the shift lever 4 is in the reverse range, the automatic operation is performed. Do. The braking force during the automatic operation is changed according to the inclination angle. Also, the load is corrected when the engine is idle.

(2) Problem of tilt determination at stop The tilt angle is detected by the G sensor. However, since the output of the G sensor fluctuates depending on the pitch of the vehicle 1 or the like (this output fluctuation varies depending on the manner of deceleration), the inclination angle cannot be determined until the fluctuation stops. Therefore, the operation start time after the vehicle 1 stops is delayed. As a result, if the driver removes his / her foot from the brake pedal after the vehicle 1 is stopped, the vehicle 1 may go backward. Therefore, the inclination determination at the time of stop is performed as follows.

(I) Stop estimation (judgment of vehicle speed 0 km / h)
The electromagnetic pickup cannot measure 3 km / h or less. Therefore, when the brake pedal is turned on to decelerate and the vehicle speed reaches 3 km / h, the deceleration is detected, and the time for the vehicle speed to be 0 km / h is estimated. Moreover, stop determination is performed from the value of the G sensor (determination is performed from the vehicle pitch at the time of stop).

(Ii) Start of tilt angle determination (signal output fluctuation)
After a certain period of time has elapsed after stopping, the determination is started. The determination start time is changed according to the deceleration.

(Iii) Inclination angle estimation The inclination angle is estimated from the data of the stopping process (inclination angle = G sensor value−acceleration). Up to here, the problem of the electric parking brake system 10 and the means for solving the problem have been described.

  As described above, the present invention provides a parking brake mechanism that applies a braking force to a wheel by actuation of an actuator, an operation switch for switching the parking brake mechanism between a braking state and a braking release state, and the operation The present invention is useful for a system including control means for controlling the braking operation of the parking brake mechanism by the actuator according to the operation of the switch.

1 is a plan view of a part of an automobile according to an embodiment of the present invention. It is a circuit diagram of an electric parking brake system. It is a side view of an operation switch. It is the figure which showed the relationship between a vehicle speed and an upper limit load. It is the figure which showed the relationship between an upper limit load and upper limit load arrival time. It is the figure which showed the ratio of the load increase at the time of dynamic parking control start. It is a part of flowchart which showed the control procedure of the braking action by an electric parking brake control apparatus. It is a part of flowchart which showed the control procedure of the braking action by an electric parking brake control apparatus. It is a part of flowchart which showed the control procedure of the braking action by an electric parking brake control apparatus. It is a modification of an operation switch.

Explanation of symbols

1 Car 10 Electric parking brake system 33 Vehicle speed sensor (movement detection means)
34 Brake switch (brake detection means)
35 Accelerator opening sensor (accelerator detection means)
36 Ultrasonic sensor for airbag (rejection detection means)
37 Idle Up Sensor (Idle Up Detection Means)
50 Electric parking brake control device (control means, determination means)
52 Parking brake body 53 Operation switch

Claims (6)

A parking brake mechanism for applying a braking force to the wheel by the operation of the actuator, an operation switch for switching the parking brake mechanism between a braking state and a braking release state, and the actuator by the actuator according to the operation of the operation switch. An electric parking brake system comprising control means for controlling the braking operation of the parking brake mechanism,
A determination means for determining whether the vehicle is moving or the vehicle is likely to move;
The control means applies a first braking force smaller than a maximum braking force to the wheel when the operation switch is braked, while the first braking force is applied to the wheel. When the determination means determines later that the vehicle is moving or that the vehicle is likely to move, a second braking force greater than the first braking force is applied to the wheels. An electric parking brake system configured as described above. The electric parking brake system according to claim 1,
An accelerator detecting means for detecting an accelerator operation;
Movement detection means for detecting that the vehicle is moving,
The determination means determines that the vehicle is moving when the accelerator operation is not detected by the accelerator detection means and the movement detection means detects that the vehicle is moving. The electric parking brake system is characterized by being configured as follows. The electric parking brake system according to claim 1,
Comprising idle-up detection means for detecting that the engine is idling up or that the engine is likely to idling up;
In the state where the vehicle is moving or the vehicle is about to move when the state where the engine is idle up or the state where the engine is about to idle up is detected by the idle up detection unit. An electric parking brake system configured to determine that there is an electric parking brake. The electric parking brake system according to claim 1,
A rear-end collision detecting means for detecting that the rear-end collision of the vehicle or the vehicle is likely to be rear-end collision;
The determination means determines that the vehicle is moving or that the vehicle is about to move when it is detected by the rear-end collision detection means that the vehicle has collided or the vehicle is about to collide. An electric parking brake system characterized by being configured to do so. The electric parking brake system according to claim 1,
Brake detection means for detecting the state of the brake pedal,
The determination means determines that the vehicle is moving or that the vehicle is likely to move when the brake detection means detects that the depressed brake pedal is further depressed. An electric parking brake system characterized by being configured. The electric parking brake system according to claim 1,
Brake detection means for detecting the state of the brake pedal,
When the brake detection means detects that the brake pedal has been depressed again after the brake pedal having been depressed returns to the normal position, the determination means determines whether the vehicle is moving or the vehicle has moved. An electric parking brake system configured to determine that the state is likely to occur.

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