JP4363142B2 - Electric parking brake system - Google Patents

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 belongs to a technical field related to an electric parking brake system including control means for controlling the 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. With such an electric parking brake, the driver can easily enter the braking state only by operating the switch when the vehicle is parked.
Japanese Utility Model Publication No. 64-26569

  However, in the above-described conventional electric parking brake, the switching between the braking state and the braking release state is performed only by the switch operation. Therefore, when the switch operation is erroneously performed particularly in the braking state, the driver There is a possibility that the brake is released without knowing, and there is room for improvement from the viewpoint of safety. On the other hand, if the driver performs a complicated operation in order to prevent an erroneous operation, the operability is deteriorated, and it becomes very troublesome especially for the driver trying to start the vehicle quickly.

  The present invention has been made in view of such a point, and an object of the present invention is to reduce the deterioration in operability and reduce the operability when switching the electric parking brake mechanism from the braking state to the braking release state. There is an attempt to prevent brake release.

To achieve the above object, in the invention 請 Motomeko 1, a parking brake mechanism for applying braking force to a wheel of the vehicle by the operation of the actuator, the parking brake mechanism to the braking state and the brake release state as the target and an operation switch for switching the electric parking brake system comprising a control means for controlling the braking operation of the parking brake mechanism according to the actuator in response to operation of the operation switch, an accelerator detection means for detecting an accelerator operation And a brake switch that detects the release of the depression of the brake pedal, and the control means is configured such that when the parking brake mechanism is in a braking state, the operation switch is released and the braking release operation is continued. The accelerator detection means When the accelerator operation is detected, switches the said parking brake mechanism to brake release state, even without a while brake releasing operation of the operation switch is made to continue, the manipulation switch is a brake releasing operation When the accelerator operation is detected by the accelerator detection means within a set time from the time, the parking brake mechanism is configured to be switched to a brake release state, and the control means is further configured to switch the parking brake mechanism to the brake state. In some cases, when the vehicle is on a downhill and the shift lever is in a forward range, the parking brake mechanism is switched to a brake release state by detecting the release of the brake pedal depression operation by the brake switch. It was .

  With the configuration described above, braking is released by operating the accelerator while continuing the brake release operation of the operation switch, so that it is possible to prevent the brake release due to an erroneous operation. That is, the accelerator operation and the brake release operation of the operation switch are both signs of the driver's intention to start, and the driver needs to operate the operation switch continuously. By letting the person make it, it is possible to reliably prevent the brake from being released due to an erroneous operation. On the other hand, even if the driver performs these two operations, the accelerator operation is an operation that is always necessary when starting the vehicle, so that the driver is not bothered. In addition, when starting off a hill, it is possible to prevent the vehicle from going backward and start easily.

Furthermore, the operability of brake release can be improved. That is, if the brake release operation of the operation switch is continued until the driver performs an accelerator operation, the end timing of the brake release operation of the operation switch tends to be earlier than the start timing of the accelerator operation. Sometimes the brake release operation has not been detected. In such a state, it becomes impossible to immediately release the braking of the parking brake mechanism, which gives the driver an annoyance. However, according to the present invention, the accelerator operation is detected within the set time (the time difference between the end timing of the brake release operation of the operation switch and the start timing of the accelerator operation (for example, 3 seconds)) from when the operation switch is released. When the vehicle is released, the parking brake mechanism is switched to the brake release state in the same manner as when the accelerator operation is detected while the brake release operation is being continued. No, the operability of brake release is improved. In addition, when starting on a hill where the driver is nervous, it is not necessary to continue the brake release operation, so the vehicle can be started even more easily.

According to a second aspect of the present invention, there is provided a parking brake mechanism that applies a braking force to a vehicle wheel by the operation of an actuator, an operation switch for switching the parking brake mechanism between a braking state and a braking release state, and the operation switch. Accelerator detecting means for detecting an accelerator operation and obstacle detection for detecting an obstacle for an electric parking brake system including a control means for controlling the braking operation of the parking brake mechanism by the actuator according to the operation of The control means includes an accelerator that is operated by the accelerator detection means while the operation switch is being brake-released and the brake-release operation is being continued when the parking brake mechanism is in a braking state. When an operation is detected, the parking brake mechanism Executes manual release to switch to the brake release state, and detects the accelerator within a set time from when the operation switch is released, even if the operation release is not continued. When the accelerator operation is detected by the means, an automatic release for switching the parking brake mechanism to the brake release state is executed. When the parking brake mechanism is in the brake state, the obstacle detection means When an obstacle is detected, it is further provided with means for prohibiting execution of the automatic release by the control means.

According to a third aspect of the invention, in the first or second aspect of the invention, when the parking brake mechanism is in a brake release state and the parking brake mechanism is in a brake release state, the control means is a first brake that is smaller than the maximum braking force. Power is applied to the wheels to switch the parking brake mechanism to a braking state, and when the vehicle is in a predetermined state after the switching, a second braking force greater than the first braking force is applied to the wheels. It shall be comprised so that it may grant.

  Thus, the control means applies a first braking force smaller than the maximum braking force to the wheel when the operation switch is braked. That is, at the normal time, a braking force smaller than the maximum braking force is applied to the wheels. In addition, the control means may use the first braking force when the vehicle is in a predetermined state (for example, a state where the vehicle is moving or a state where the vehicle is likely to move) after the first braking force is applied to the wheels. Is applied to the wheel. That is, when the vehicle is moving or is in a predetermined state where it is likely to move even though the braking force in the normal state is applied to the wheel, the braking force greater than that in the normal state is applied to the wheel. . 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. As a result, the electric parking brake system can be reduced in weight and the burden on the electric parking brake system (actuator, etc.) can be reduced, and the vehicle can be parked and stopped reliably not only during normal times but also when necessary. Can do.

As described above, according to the electric parking brake system of the present invention, when the accelerator switch is detected while the operation switch is brake-released and the brake-release operation is continuously performed, the parking brake mechanism is activated. By switching from the braking state to the braking release state, it is possible to prevent the brake release due to an erroneous operation while reducing the deterioration of the operability of the brake release, and to easily start the slope. Become. In addition, when an accelerator operation is detected within a set time after the operation switch is released from the braking operation, the operation switch is switched to the brake release state, so that the end timing of the brake release operation of the operation switch and the accelerator operation Inability to release due to deviation from the start timing can be prevented, and the operability of brake release can be improved.

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

  As shown in FIG. 1, a vehicle 1 (automobile) includes an instrument panel (hereinafter referred to as an instrument panel) 2 that extends in the vehicle width direction, a steering wheel 3 that projects 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 houses 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. ing.

  As shown in FIG. 2, the electric parking brake system 10 according to the embodiment of the present invention is electrically operated according to the operation of the vehicle-side control device 30 that controls various vehicle components of the vehicle 1 and the operation switch 53. An electric parking brake control device 50 that controls the braking operation of the parking brake mechanism by the motor 52a is provided (the operation switch 53, the electric motor 52a, and the parking brake mechanism will be described later). The control means referred to in the present invention corresponds 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. The accelerator detecting means in the present invention corresponds to the accelerator opening sensor 35, and the brake detecting 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 of the vehicle 1 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-side control device 30 when the driver depresses the brake pedal.

  The accelerator opening sensor 35 detects an accelerator opening that changes in accordance with the amount of depression of the accelerator pedal, and transmits an accelerator opening signal having the detected accelerator opening information to the vehicle-side control device 30. By transmitting the accelerator opening signal, it can be seen that the accelerator is turned on (accelerator operation has been performed).

  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. is 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 operating position (braking position), a neutral position, and a releasing position (braking releasing position) (see FIG. 3). When the application of force to the operation switch 53 is stopped after the operation switch 53 is switched to the operating position or the release position, the operation switch 53 automatically returns to the neutral position. When the operation switch 53 is positioned at the operating position, an operation signal is transmitted to the electric parking brake control device 50, and when the operation switch 53 is positioned at the release position, a release signal is transmitted to the electric parking brake control device 50. Further, the operation switch 53 functions as a normal control switch when the vehicle speed is slower than 5 km / h, and functions as a switch for dynamic parking control (dynamic PA control) when the vehicle speed is 5 km / h or more. 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)
During normal control, the driver pulled the operation switch 53 only once (the electric parking brake control device 50 received the operation signal only once when the driver switched the operation switch 53 to the operating position only once). ), The electric parking brake control device 50 determines that the parking brake mechanism applies a braking force corresponding to 70% of the maximum braking force (hereinafter referred to as “braking force corresponding to 70% of the maximum braking force”) to “70% load”. The electric motor 52a is controlled so as to be applied 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.

  In addition, when the driver pulls the operation switch 53 only twice during normal control (the electric parking brake control device 50 receives the actuation signal only twice), the electric parking brake control device 50 A braking force corresponding to 100% of the power (hereinafter, “braking force corresponding to 100% of the maximum braking force” is referred to as “100% load”) is applied to the wheel.

  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 vehicle 1 is in a predetermined state. In this embodiment, the vehicle 1 is in a moving state or a state where the vehicle 1 is likely to move. (Details of the additional pulling condition will be described later). The second braking force referred to in the present invention corresponds to 100% load.

(Manual release)
When the manual release condition is satisfied during the normal control and the parking brake mechanism is in the operating state, the electric parking brake control device 50 switches the parking brake mechanism from the operating state to the released state. Here, when the manual release condition is satisfied, the driver presses the operation switch and continues to perform the push operation (the electric parking brake control device 50 continuously receives the release signal). In the meantime, the driver's accelerator pedal depression operation (accelerator operation) is detected based on the accelerator opening signal from the accelerator opening sensor 35. 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 operating state during normal control, the electric parking brake control device 50 may be used when the automatic release condition is satisfied even if the operation switch 53 is not continuously pressed. Releases the braking of the wheel and switches the parking brake mechanism from the activated state to the released state. Here, the case where the automatic release condition is satisfied means that the preset set time T elapses from when the operation switch 53 is pressed (from when the electric parking brake control device 50 receives the release signal). In this case, the driver's accelerator pedal depression operation (accelerator operation) is detected based on the accelerator opening signal from the accelerator opening sensor 35.

-Dynamic parking control-
(Operation)
When the driver pulls the operation switch 53 during the dynamic parking control, the electric parking brake control device 50 applies a braking force corresponding to the vehicle speed (details of this braking force will be described later) 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 position by removing the finger from the operation switch 53, the electric parking is performed. 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)
When the driver presses the operation switch 53 after a predetermined time (for example, 5 seconds in the present embodiment) elapses after the braking of the wheel is maintained by the dynamic parking control. The electric parking brake control device 50 releases the held braking.

  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 40. The parking brake state signal includes a 70% load operation state signal, a 100% load operation state signal, and a release state 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, and it is determined whether or not the operation switch 53 is in the neutral position or the release position. 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 the operating position. 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 to determine whether or not the vehicle 1 is turning or the accelerator is in an ON state. 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, where is the number of times that the driver pulled the operation switch 53 is the first time (the operation switch 53 is switched to the operating position for the first time). 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, where it is determined whether or not the additional discount condition is satisfied (details of the determination procedure as to 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 the 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)
As shown in FIG. 8, first, in step S19, the flag is set to F = 2, and the fact that dynamic parking control is being performed is displayed 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, whether or not the number of times the operation switch 53 has been pulled is the first time is determined based on whether the elapsed time from the previous pulling of the operation switch 53 to the current pulling is equal to or greater than a preset reference time. Based on whether or not. If the elapsed time is equal to or longer than the reference 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 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 position, 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 predetermined time, ie, 5 seconds 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 release position. If the decision result in the step S28 is YES, the process proceeds to a step S29 to release the braking, 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 the neutral position. If the determination result in step S30 is YES, the process proceeds to step S29, where braking is released. On the other hand, if the determination result in step S30 is NO, the process proceeds to step S22, and the braking force corresponding to the vehicle speed 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 it is determined that the braking operation of the operation switch 53 is an erroneous operation and the flag is set to F = 0, and the parking brake mechanism is activated. If it is, set it to the release state. 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 refers to a state where the depressed brake pedal is further depressed (determined by another brake switch or a brake switch capable of detecting the depression amount) or a depressed brake. After the pedal returns to the initial position, the brake pedal is depressed again. 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, where it is determined whether the accelerator is in an ON state based on the accelerator opening signal from the accelerator opening sensor 35. 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.

  According to the above control, when the driver pulls the operation switch 53 only once during normal control and the parking brake mechanism is released, the electric parking brake control device 50 applies a 70% load to the wheels. The parking brake mechanism is switched to the operating state. That is, during normal times, a 70% load smaller than the maximum braking force is applied to the wheels. Further, during normal control, after the driver pulls the operation switch 53 only once and 70% load is applied to the wheels (after the parking brake mechanism is switched to the operating state), the additional pulling condition is satisfied. In such a case, a 100% load is applied to the wheel. That is, when the vehicle 1 is moving or the vehicle 1 is about to move despite the 70% load being applied to the wheels, specifically, the idle-up state, the rear-end collision state, When the vehicle is in one of the brake depression state, the accelerator ON state, and the accelerator OFF state (the state where the accelerator operation is not performed) and the vehicle 1 is moving, it is larger than 70% load. % 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 (electric motor 52a, etc.) can be reduced, and the vehicle 1 can be reliably used not only during normal times but also when necessary. Can be parked and parked.

  Further, during normal control and when the parking brake mechanism is in an operating state, as shown in FIG. 10, the driver presses the operation switch 53 (releases braking) and continues to perform the pressing operation. When the accelerator is operated (the accelerator is turned on) while the operation switch 53 continues to be positioned at the release position, that is, while the electric parking brake control device 50 continues to receive the release signal, Release the braking on the wheels and switch the parking brake mechanism to the release state. This accelerator operation is a sign of the driver's intention to start, and the driver must keep pressing the operation switch 53, so that it is possible to reliably prevent the brake from being released due to an erroneous operation. On the other hand, even if the driver performs these two operations, the accelerator operation (depressing the accelerator pedal) is an operation that is always necessary when starting the vehicle. There is no. In addition, when starting off a hill, it is possible to prevent the vehicle from going backward and start easily.

  When the parking brake mechanism is in the operating state during normal control, the operation switch 53 is not depressed as shown in FIG. 11 even if the operation switch 53 is not continuously depressed. The accelerator operation is detected after elapse of time t from the time of operation (from the time when the electric parking brake control device 50 receives the release signal), and if the time t is equal to or less than the set time T, braking is performed when the accelerator operation is detected. Is released. That is, if the push operation of the operation switch 53 is continued until the driver performs the accelerator operation, the operation switch 53 of the present embodiment is returned to the neutral position, and thus the operation switch 53 is operated with a predetermined force or more. Therefore, the end timing of the push operation of the operation switch 53 tends to be earlier than the start timing of the accelerator operation. When the accelerator operation is performed, the electric parking brake control device 50 has already received the release signal. It may be in a state that is not. In such a state, it becomes impossible to immediately release the braking of the parking brake mechanism, which gives the driver an annoyance. However, as described above, if the accelerator operation is performed within the set time T from when the operation switch 53 is pushed, the parking brake mechanism is switched to the braking release state. In addition, the operability of brake release is improved. In addition, when starting a hill where the driver is nervous, there is no need to keep pressing the operation switch 53, so the vehicle can be started even more easily. The set time T may be a time (for example, 3 seconds) that can correspond to the start of a hill, which is a time difference between the end timing of the pressing operation of the operation switch 53 and the start timing of the accelerator operation.

(Other embodiments)
In the present embodiment, the operation switch 53 is composed of a switchable push-pull operation switch to three and a release position and a neutral position and an operating position (see Figure 3), as shown in FIG. 12, actuation, You may comprise the pulling operation switch which can be switched to two of a cancellation | release position and a neutral position. Also in this case, when the driver stops applying force to the operation switch 53 after switching the operation switch 53 to the operation / release position, the driver automatically returns to the neutral position. Such a pull operation switch distinguishes between activation and release according to the time when the driver pulls the operation switch 53.

  In the present embodiment, the operation switch 53 is a single momentary switch, but a switch for bringing the parking brake mechanism into an operating state and a switch for putting it into a released state may be provided separately. In addition, a switch for setting the release state by auto release may be provided separately from the switch for setting the release state by manual release.

  Furthermore, in this embodiment, the dynamic parking control is performed so that the parking brake mechanism functions like a foot brake, but this dynamic parking control may not be required.

-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). Also, the braking load may be set according to the operation time of the operation switch 53 (for example, 70% load when the operation time is shorter than 0.5 seconds, 100% load when the operation time is 0.5 seconds or longer). ).

(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. When the vehicle 1 is on a downhill and the shift lever 4 is in the forward range, the configuration for automatically releasing the brake pedal by turning it off constitutes part of the invention according to claim 1. Is.

(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. The configuration for prohibiting automatic release when an obstacle is detected constitutes a part of the invention according to claim 2.

(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. When the operation switch 53 is set to the release position 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 set, 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 this point, further problems of the electric parking brake system 10 and means for solving the problems have been described.

  The present invention is useful for an electric parking brake system that controls the braking operation of a parking brake mechanism by an actuator in accordance with the operation of an operation switch.

1 is a plan view of a part of an automobile equipped with an electric parking brake system 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 a graph which shows the relationship between a vehicle speed and an upper limit load. It is a graph which shows the relationship between an upper limit load and upper limit load arrival time. It is a graph which shows the rate of a load rise at the time of dynamic parking control start. It is a part of flowchart which shows the control procedure of the braking action by an electric parking brake control apparatus. It is a part of flowchart which shows the control procedure of the braking action by an electric parking brake control apparatus. It is a part of flowchart which shows the control procedure of the braking action by an electric parking brake control apparatus. It is a time chart which shows the timing relationship of release operation of an operation switch, and accelerator operation in the case of releasing brake by manual release. It is a time chart which shows another timing relation of release operation of an operation switch, and accelerator operation in the case of releasing brake by automatic release. FIG. 6 is a view corresponding to FIG. 3 showing a modification of the operation switch.

Explanation of symbols

1 Car 10 Electric parking brake system
34 brake switch 35 accelerator opening sensor (accelerator detection means)
50 Electric parking brake control device (control means)
52 Parking brake body 53 Operation switch

Claims (3)

A parking brake mechanism that applies a braking force to the wheels of the vehicle by actuation of the actuator, an operation switch for switching the parking brake mechanism between a braking state and a braking release state, and the actuator according to the operation of the operation switch An electric parking brake system comprising a control means for controlling the braking operation of the parking brake mechanism by
An accelerator detecting means for detecting an accelerator operation ;
A brake switch that detects the release of the brake pedal depressing operation ,
When the parking brake mechanism is in a braking state, the control means detects an accelerator operation by the accelerator detecting means while the operation switch is being braked and the brake releasing operation is being continued. Sometimes, the parking brake mechanism is switched to a braking release state, and within a set time from when the operation switch is released, even if the operation switch is not continuously released. When an accelerator operation is detected by the accelerator detection means, the parking brake mechanism is configured to switch to a braking release state,
Further, when the parking brake mechanism is in a braking state and the vehicle is on a downhill and the shift lever is in the forward range, the control means detects parking brake by detecting release of a brake pedal depressing operation by the brake switch. An electric parking brake system configured to switch a mechanism to a brake release state . A parking brake mechanism that applies a braking force to the wheels of the vehicle by actuation of the actuator, an operation switch for switching the parking brake mechanism between a braking state and a braking release state, and the actuator according to the operation of the operation switch An electric parking brake system comprising a control means for controlling the braking operation of the parking brake mechanism by
An accelerator detection means for detecting an accelerator operation;
An obstacle detection means for detecting an obstacle,
When the parking brake mechanism is in a braking state, the control means detects an accelerator operation by the accelerator detecting means while the operation switch is being braked and the brake releasing operation is being continued. When the manual release for switching the parking brake mechanism to the brake release state is executed and the operation switch is released even if the brake release operation of the operation switch is not continued. When the accelerator operation is detected by the accelerator detection means within a set time from the start, the automatic release for switching the parking brake mechanism to the brake release state is executed.
When the parking brake mechanism is in a braking state, the electric motor further includes means for prohibiting execution of the automatic release by the control means when an obstacle is detected by the obstacle detection means. Parking brake system. In the electric parking brake system according to claim 1 or 2 ,
The control means applies a first braking force smaller than the maximum braking force to the wheel when the operation switch is braked when the parking brake mechanism is in a brake release state, thereby braking the parking brake mechanism. And a second braking force that is greater than the first braking force is applied to the wheels when the vehicle is in a predetermined state after the switching. Brake system.

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