JP3449319B2 - Electric parking brake device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric parking brake device, and more particularly, to an electric parking brake device having an electric hoisting device capable of hoisting a parking brake cable to operate the parking brake.

[0002]

2. Description of the Related Art Conventionally, as an electric parking brake device of this type, a pulley is rotated by a motor to wind up a parking brake cable to operate the parking brake and, conversely, rewind the cable to release the parking brake. Have been proposed (for example, JP-A-59-143748).
JP-A-61-108038, etc.).

[0003]

However, in these electric parking brake devices, it may be determined that the parking brake is activated even when the cable of the parking brake is broken or stretched.

As one method for solving at least a part of these problems, the applicant has detected that the disconnection of the parking brake cable is abnormal when the operating force of the parking brake does not exceed a predetermined value within a predetermined time. A parking brake device has been proposed (Jikkou 5-33432).

An object of the electric parking brake device of the present invention is to detect an abnormality in the parking brake. Another object of the electric parking brake device of the present invention is to detect an abnormality of the parking brake so as not to affect the driving and the state of the vehicle.

[0006]

Means for Solving the Problem and Its Action / Effect The electric parking brake system of the present invention employs the following means in order to achieve at least a part of the above objects.

The first electric parking brake system of the present invention is
An electric parking brake device having an electric hoisting means capable of hoisting a parking brake cable to operate the parking brake, wherein hoisting force detecting means for detecting hoisting force by the electric hoisting means and hoisting by the electric hoisting means. A winding amount detecting means for detecting the winding amount of the cable, and an abnormality detecting means for detecting an abnormality of the parking brake based on the detected winding amount and the winding force detected by the winding force detecting means. The point is to prepare.

In the first electric parking brake device of the present invention, the abnormality detecting means is wound by the hoisting force by the electric hoisting means detected by the hoisting force detecting means and the electric hoisting means detected by the hoisting amount detecting means. The abnormality of the parking brake is detected based on the winding amount of the parking brake cable. The reason why the abnormality of the parking brake can be detected based on the hoisting force and the hoisting amount is that this relationship is related to the extension, breakage, disconnection, and the like of the cable. According to such a first electric parking brake device of the present invention, an abnormality of the parking brake can be detected.

In the first electric parking brake device of the present invention as described above, the hoisting force detecting means may be means for detecting the hoisting force based on the electric power supplied to the electric hoisting means. . In this way, the hoisting force can be detected without directly detecting the hoisting force. Here, "electric power" includes, for example, the relationship between the current value and time supplied to the electric hoisting device, the relationship between the voltage value and time, the relationship between the current value and the voltage value, the current value at a certain time, and the certain time. A value corresponding to the electric power calculated based on the voltage value at is included.

Further, in the first electric parking brake device of the present invention, the electric hoisting means has a hoisting part for hoisting the cable by rotation, and the hoisting amount detecting means detects the rotation of the hoisting part of the electric hoisting means. It may be a means for detecting the winding amount based on the above. In this way, the winding amount can be detected based on the rotation of the winding portion.

Further, in the first electric parking brake device of the present invention, the abnormality detecting means detects an abnormality on the basis of the detected change amount of the hoisting force and the detected change amount of the hoisting amount. Can also be In this way, the abnormality can be detected regardless of whether the parking brake is in the activated state or the released state.

Alternatively, in the first electric parking brake device of the present invention, the abnormality detecting means controls the parking brake to have a predetermined braking force or less when the parking brake is not actuated by hoisting by the electric hoisting means. It may be a means for drivingly controlling the electric hoisting means and detecting the abnormality within a range until power is applied. In this way, the abnormality can be detected without significantly affecting the state of the vehicle. here,
The “predetermined braking force” may be a value that is obtained in advance by experiments or the like, or may be changed based on the speed or temperature when the braking force generated due to the speed or temperature changes.

Further, in the first electric parking brake device of the present invention, the abnormality detecting means applies a braking force to the parking brake by hoisting or rewinding by the electric hoisting means when the parking brake is operating. It may be a means for detecting the abnormality by driving and controlling the electric hoisting means within a range in which the braking force does not change more than a predetermined value. In this way, the abnormality can be detected without significantly affecting the state of the vehicle. In addition,
The “predetermined braking force” has the same meaning as described above.

In the first electric parking brake device of the present invention in which an abnormality is detected with the drive control of the electric hoisting means, the abnormality detecting means controls the electric hoisting means to operate or release the parking brake. It may be a means for detecting an abnormality by driving at a speed slower than the actual driving speed. With this, it is possible to reduce the operating noise generated when the electric hoisting means is driven and controlled to detect the abnormality.

An electric parking brake device according to a reference example of the present invention is an electric parking brake device having an electric hoisting device capable of hoisting a parking brake cable to operate the parking brake. Tension detecting means for detecting, and abnormality detecting means for detecting abnormality of the parking brake based on a change in tension of the cable detected by the tension detecting means when the electric hoisting means winds or unwinds the cable. The point is to have and.

In the electric parking brake device according to the reference example of the present invention, the abnormality detecting means changes the tension of the parking brake cable detected by the tension detecting means when the electric hoisting means winds or unwinds the cable. Based on this, an abnormality of the parking brake is detected. The reason why an abnormality can be determined based on the change in the cable tension is that the winding or unwinding of the cable directly affects the cable tension, and if an abnormality occurs, the effect will be different. . According to the electric parking brake device of the reference example of the present invention, an abnormality of the parking brake can be detected.

In the electric parking brake device according to the reference example of the present invention, the tension detecting means may be means for detecting the tension based on the electric power supplied to the electric hoisting means. By doing so, the tension of the cable can be detected without directly detecting the tension of the cable.

In the electric parking brake device according to the first or reference example of the present invention, a brake pedal depression detecting means for detecting depression of the brake pedal is provided, and the abnormality detecting means is the brake pedal depression detecting means. Thus, it may be a means for detecting the abnormality while detecting the depression of the brake pedal.

Further, in the electric parking brake system of the first or reference example of the present invention, the abnormality detecting means may be means for detecting an abnormality in the extension of the cable.

Further, the electric parking brake system according to the first or reference example of the present invention may be provided with an output means for outputting the abnormality when the abnormality is detected by the abnormality detecting means. This allows the driver or the like to quickly recognize the abnormality.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram showing an outline of a configuration of an electric parking brake device 20 which is an embodiment of the present invention. The electric parking brake device 20 of the embodiment includes parking brake units 22 and 24 that apply braking force to the left and right rear wheels 12 and 14 of the vehicle, and the parking brake units 22 and 24.
A cable 26 connected to the cable 24, a cable winding unit 30 that winds the cable 26 to operate the parking brake units 22 and 24, and an electronic control unit 50 that controls the entire apparatus.

The cable 26 is fixed to a length adjusting member 27 by a bolt 28 so that its length can be adjusted.
That is, by rotating the bolt 28, the cable 2
By adjusting the length between the six ends and the bolt 28, the length of the cable 26 can be adjusted as a result.

FIG. 2 is a configuration diagram illustrating the configuration of the cable winding unit 30. As illustrated, the cable hoisting unit 30 includes a cable hoisting mechanism 32.
And the electric motor 4 for driving the cable winding mechanism 32.
2 and is fixed to the vehicle by fixing members 47 to 49. The worm gear 3 is attached to the drive gear 34 attached to the rotary shaft of the rotor of the electric motor 42.
The rotation speed adjusting gear 36 coaxial with the gear No. 8 is meshed, and the worm gear 38 is rotated by driving the electric motor 42. A fan-shaped winding gear 40 that winds the cable 26 meshes with the worm gear 38, and the worm gear 38 rotates left and right to cause the cable 2 to rotate.
6 can be rolled up or rewound.
The rotary shaft of the hoisting gear 40, rotation angle sensor 60 that detect the θ rotation angle of the hoist gear 40 is attached. The rotation speed of the electric motor 42 can be adjusted by changing the duty ratio of the applied voltage. When the cable 26 is wound around the winding gear 40, the parking brake units 22 and 24 are actuated by the tension, and the braking force acts on the left and right rear wheels 12 and 14.

The electronic control unit 50 is configured as a microprocessor mainly composed of a CPU 52, and has a ROM 54 storing a processing program, a RAM 56 temporarily storing data, and an input / output port (not shown). With. In this electronic control unit 50,
A rotation angle θ from a rotation angle sensor 60 attached to the rotation shaft of the hoisting gear 40 and wheel speeds Vl and V from wheel speed sensors 62 and 64 attached to the left and right rear wheels 12 and 14, respectively.
r, the electric motor 42 detected by the current sensor 61 attached to the electric motor 42 of the cable hoisting unit 30
Applied current I to the switch, an on / off signal SW from an operation switch 66 arranged on the panel in the front of the driver's seat and instructing the operation and release of the parking brake, a shift position SP from a shift position sensor 71 for detecting the position of the shift lever 70, An accelerator pedal position AP from an accelerator pedal position sensor 73 that detects the amount of depression of the accelerator pedal 72, a brake pedal position BP from a brake pedal position sensor 75 that detects the amount of depression of the brake pedal 74, and an ignition signal IG from an ignition switch 76. Is input through the input port. Further, a drive signal to the electric motor 42, a display signal G to the liquid crystal panel 80 fitted in a part of the panel on the front side of the driver's seat, and the like are output from the electronic control unit 50 through the output port.

In the electric parking brake device 20 of the embodiment thus constructed, the automatic parking brake control for automatically operating and releasing the parking brake according to the state of the vehicle is performed. The automatic operation of the parking brake is, for example, when the shift lever 70 is in the stop position of the P position or the N position, the vehicle speed is substantially zero, and
When the brake pedal 74 is stepped on and the ON signal is output from the brake pedal position sensor 75, the electronic control unit 50 outputs a drive signal to the electric motor 42 to drive the electric motor 42, assuming that the operating condition is satisfied. Be done. Further, the automatic release of the parking brake can be performed, for example, by setting the shift lever 70 to the P position or N position.
A drive signal is output from the electronic control unit 50 to the electric motor 42 when the release condition is satisfied when the vehicle is in a traveling position other than the position and the accelerator pedal position sensor 73 outputs an ON signal when the accelerator pedal 72 is depressed. By driving the electric motor 42.

In addition to such automatic parking brake control, when the operation switch 66 is operated, the operation of the parking brake is controlled based on the operation of the operation switch 66.

Next, the electric parking brake device 20 of the embodiment
Will be described, especially when detecting an abnormality in the cable 26. FIG. 3 is a flowchart showing an example of a cable abnormality determination processing routine executed by the electronic control unit 50 in the electric parking brake system 20 of the embodiment. This routine is executed together with the operation of the parking brake when the automatic operation of the parking brake in the automatic parking brake control is performed or when the operation of the operation switch 66 is performed.

When the cable abnormality determination processing routine is executed, the CPU 52 of the electronic control unit 50 first reads the current I applied to the electric motor 42 detected by the current sensor 61 (step S100), and then the electric motor 42 is read. A process of estimating the output output load F is executed (step S102). Here, the output load F of the electric motor 42 can be estimated by the current I applied to the electric motor 42 because the output load F is the current I applied to the electric motor 42.
It is based on changing with the change of. In the embodiment, the relationship between the current I and the output load F is obtained by experiments and stored in advance in the ROM 54 as a map. When the current I is given, the output load F corresponding to the current I is obtained from this map.
Shall be derived.

The output load F thus estimated is the threshold F1.
After waiting for the above (step S104), the rotation angle θ detected by the rotation angle sensor 60 is read (step S106), and the read rotation angle θ is taken up by the winding gear 40.
A process for converting the length of the cable 26 wound up on the cable 26 (hereinafter referred to as the cable stroke S) is performed (step S).
108). Here, the threshold value F1 is set as an appropriate value of the output load F when determining the length of the cable 26, and it is preferable to use a value smaller than the normally used output load.

Then, the converted cable stroke S is derived from the output load F with a threshold value f1 (F) and a threshold value f.
2 (F) (steps S110 and S112), and when the cable stroke S is less than the threshold f2 (F), it is determined that the length of the cable 26 is normal (step S11).
4) When the cable stroke S is greater than or equal to the threshold value f2 (F) and less than the threshold value f1 (F), the cable 26 is slightly extended, and an extension alarm that prompts adjustment is output (step S11).
6) When the cable stroke S is equal to or greater than the threshold value f1 (F), it is determined that the parking brake is not effective enough, and the effectiveness is output (step S118), and this routine is ended. FIG. 4 shows an example of the relationship between the normal cable stroke S or the extended cable stroke S and the output load F. The straight line SF1 in the figure shows the relationship between the cable stroke S and the output load F in a normal initial state, and the straight line SF1
2 shows the relationship between the cable stroke S and the output load F as a threshold value for promoting the adjustment of the length of the cable 26, and the straight line S
F3 shows the relationship between the output stroke F and the cable stroke S as a threshold value for determining that the parking brake is insufficiently effective. Threshold value f1 in the cable abnormality determination routine
(F) is a value obtained by comparing the output load F when the output load F exceeds the threshold value F1 with the relationship of the straight line SF3 in FIG. 4, and the value S3 when the output load F matches the threshold value F1.
(See FIG. 4). Also, the threshold f2 (F)
Is a value obtained by comparing the output load F when the output load F exceeds the threshold value F1 with the relationship of the straight line SF2 in FIG.
When the output load F matches the threshold value F1, the value S2 (see FIG.
See). That is, the output load F is the threshold F1.
When the cable stroke S is less than the value S2, it is determined that the parking brake can be normally applied, and the cable stroke S is the value S2 or more and the value S3.
When it is less than the above, it is determined that the extension of the cable 26 needs to be adjusted although the parking brake can be effectively operated, and when the cable stroke S is the value S3 or more, the parking brake cannot be effectively operated in some cases. Is determined. When it is determined that the extension of the cable 26 needs to be adjusted, or when it is determined that the parking brake cannot be effectively operated, an output such as displaying it on the liquid crystal panel 80 as an alarm is output. Do it.

According to the electric parking brake device 20 of the embodiment that executes the above-described cable abnormality determination processing routine, it is possible to detect an abnormality due to the extension of the cable 26 of the parking brake. Moreover, since the condition in which the expansion of the cable 26 needs to be adjusted is output as an alarm before outputting the condition in which the parking brake cannot be effectively operated as the abnormal condition, the cable 26 is output as an alarm. The elongation of 26 can be adjusted.

In the cable abnormality determination processing routine executed by the electric parking brake device 20 of the embodiment, the output load F of the electric motor 42 is estimated by detecting the current I applied to the electric motor 42. Applied current I
And the voltage may be detected, and the output load F may be estimated based on the electric power. Of course, the output load F of the electric motor 42
May be directly detected.

In the cable abnormality determination processing routine executed by the electric parking brake device 20 of the embodiment, the rotation angle θ of the hoisting gear 40 is detected, and this is detected as the cable stroke S.
However, the cable stroke S may be directly detected.

In the electric parking brake system 20 of the embodiment,
When the parking brake is automatically operated in the automatic parking brake control or when the parking brake is operated by operating the operation switch 66, the parking brake is operated and the cable abnormality determination routine illustrated in FIG. 3 is executed. As described above, when the parking brake is automatically operated in the automatic parking brake control or the parking brake is operated by operating the operation switch 66, the parking brake is operated together with the parking brake. The cable abnormality determination processing routine may be executed.

In the electric parking brake device 20 of the embodiment,
When the parking brake is automatically operated in the automatic parking brake control described above or when the parking brake is operated by operating the operation switch 66, the abnormality of the extension of the cable 26 is determined together with the operation of the parking brake. In addition, abnormality of the cable 26 of the parking brake is determined as one of the initial checks when the vehicle is started. FIG. 5 is a flowchart showing an example of a starting cable abnormality determination processing routine executed by the electronic control unit 50 when starting the vehicle. This routine is executed in parallel with other initial checks when the ignition signal IG from the ignition switch 76 is turned on.

When the start-up cable abnormality determination processing routine is executed, the CPU 52 of the electronic control unit 50 first executes processing for reading the brake pedal position BP detected by the brake pedal position sensor 75 (step S120). When it is determined that the brake pedal position BP is ON, that is, the brake pedal 74 is depressed (step S122), a process of reading the shift position SP detected by the shift position sensor 71 is executed (step S12).
4). Then, the shift lever 70 moves from the P position to the R position.
It waits until it is operated to the position, the N position, or the D position (step S126).

When the brake pedal 74 is depressed and the shift lever 70 is operated, it is determined whether or not the current parking brake state is the operating state (step S128). When the parking state is in the operating state, the operating state abnormality illustrated in FIG. An abnormality of the parking brake cable 26 is determined by the determination processing (step S130), and when not in an operating state, that is, in the released state, an abnormality of the parking brake cable 26 is determined by the release state abnormality determination processing illustrated in FIG. Step S1
32), the judgment is output (step S134), and the present routine ends. Note that the determination output is performed by displaying the determination result on the liquid crystal panel 80, that is, by displaying, for example, "abnormality of parking cable".

When it is determined in step S128 that the engine is in the operating state and the operating state abnormality determination process illustrated in FIG. 6 is executed, the CPU 52 of the electronic control unit 50 first causes the winding gear detected by the rotation angle sensor 60. The rotation angle θ of 40 is read (step S140), the read rotation angle θ is set to the initial value θs (step S142), and the process of driving the electric motor 42 in slow reverse rotation is executed (step S144). The slow reverse drive of the electric motor 42 is performed by making the duty ratio of the voltage applied to the electric motor 42 smaller than a normal ratio. By controlling in this way, the electric motor 42 rotates slowly and the cable 26
To rewind.

Next, the current I applied to the electric motor 42 detected by the current sensor 61 and the rotation angle θ of the winding gear 40 are read (step S146), and the cable stroke S is converted from the read rotation angle θ ( Step S
148) and stores the converted cable stroke S and current I in order in a predetermined area of the RAM 56 (step S1).
50). Then, the rotation angle θ is changed from the initial value θs to a predetermined value Δθ.
Is compared with the value obtained by subtracting (step S152), and steps S146 to S152 are performed until the rotation angle θ becomes smaller than this value.
The process of is repeated. Here, the predetermined value Δθ is the hoisting gear 40 necessary for confirming that the relationship between the change in the current I and the cable stroke S changes stably and linearly.
Is set as the rotation angle of the. The electric motor 4 in FIG.
An example of the relationship between the electric current I applied to 2 and the cable stroke S is shown. As shown, the change in the cable stroke S with respect to the change in the current I applied to the electric motor 42 exhibits hysteresis. The predetermined value Δθ is set in order to accurately check the relationship between the current I and the cable stroke S in the state where the hysteresis does not affect.

When the read rotation angle θ becomes equal to or smaller than the value obtained by subtracting the predetermined value Δθ from the initial value θs, the process of driving the electric motor 42 in the slow forward rotation to restore the original operating state is executed (step S154). In parallel with this, the processing for determining the abnormality of the cable 26 (steps S154 to S162) is executed. That is, first, the process of calculating the differential value dI / dS is executed (step S156). In the embodiment, the cable strokes S stored in order in step S150
And the last value Sn, In of the current I and the previously stored values Sn-1, In-1 are calculated as the ratio of the respective deviations.

Then, the absolute value of the calculated differential value dI / dS is compared with the threshold value R1 and the threshold value R2 (step S15).
8), the absolute value of the differential value dI / dS is the threshold value R1 and the threshold value R2.
When it is within the range defined by and, it is determined to be normal (step S160), and when the differential value dI / dS is outside this range, it is determined to be abnormal (step S16).
2). FIG. 9 shows an example of the relationship between the current I applied to the electric motor 42 and the cable stroke S and the abnormal region thereof. The curve shown as "Normal IS" in the figure is shown in FIG.
The relationship between the current I applied to the electric motor 42 and the cable stroke S in the normal state of the cable 26 described with reference to FIG. Note that the illustration of the hysteresis is omitted. As shown in the figure, the relationship between the current I applied to the electric motor 42 and the cable stroke S when the cable 26 is in a normal state shows a substantially linear linear relationship in a certain operating region, and its inclination is substantially constant. If this inclination shifts to the lower direction, the cable 26 often loosens, breaks, or comes off. On the contrary, if it shifts to the higher inclination side, the cable 26 gets caught and fixed to one of the members. It can be understood from experiments and past rules of thumb that it is often locked and locked. The threshold value R1 and the threshold value R2 in the embodiment are set as such a threshold value on the low slope side and a threshold value on the high slope side, and the values are determined by an experiment or the like depending on the electric motor 42 and the parking brake units 22, 24 used. .

FIG. 10 shows an example of the operation of the electric motor 42, the change in the cable tension T, and the change in the cable stroke S during the operation state abnormality determination process. As shown,
At time t1, the ignition switch 76 is turned on and the slow reverse drive of the electric motor 42 is started. This electric motor 4
Although the cable tension T decreases with the driving of 2, the cable stroke S does not change until time t2 due to hysteresis. At time t3 when the deviation of the cable stroke S from the initial value is ΔS, that is, when the deviation of the rotation angle θ from the initial value θs becomes a predetermined value Δθ, the electric motor 42 is controlled to the slow forward rotation drive and is returned to the original operating state. Be done. At this time, the differential value dI / dS is calculated, and the calculated differential value dI /
The dS is compared with the threshold values R1 and R2 to determine the abnormality of the cable 26. When returning to the original operating state, the cable tension T changes at the same time as the forward rotation of the electric motor 42, but the cable stroke S does not change until time t4 due to hysteresis. Since the abnormality of the cable 26 is determined when the current I applied to the electric motor 42 and the cable stroke S have a stable and linear relationship, it is not necessary to reduce the cable tension T more than necessary. Therefore, the abnormality of the cable 26 can be detected within a range that does not affect the operating state of the parking brake.

When it is determined in step S128 in the starting cable abnormality determination processing routine of FIG. 5 that the operating state is not determined and the release state abnormality determination processing illustrated in FIG. 7 is performed, the CPU 52 of the electronic control unit 50 firstly operates the electric motor. Processing for driving the slow forward rotation of 42 is performed (step S170). The slow forward drive of the electric motor 42 is performed by the electric motor 4
The duty ratio of the voltage applied to 2 is made smaller than the normal forward drive ratio.

Subsequently, the current I applied to the electric motor 42 and the rotation angle θ of the winding gear 40 are read (step S
172), the cable stroke S is converted from the rotation angle θ of the winding gear 40 (step S174), and the converted cable stroke S and current I are stored in a predetermined area of the RAM 56 in order (step S176).
Then, the current I is compared with the threshold value Iref (step S1
78), the processes of steps S172 to S178 are repeated until the current I becomes equal to or more than the threshold value Iref. Where the threshold I
The ref is set to a value slightly higher than the lower limit value of the current at which the current I applied to the electric motor 42 and the cable stroke S have a stable and linear relationship (see FIG. 8).

When the current I exceeds the threshold value Iref, the process of driving the electric motor 42 in the slow reverse rotation to restore the original released state is executed (step S180), and in parallel therewith, the process of judging the abnormality of the cable 26 ( Step S182
~ S188) is performed. This processing is performed in steps S156 to S1 in the operation state abnormality determination processing routine of FIG.
This is the same as the process of 62. Therefore, detailed description of this process is omitted.

FIG. 11 shows an example of the operation of the electric motor 42, the change in the cable tension T, and the change in the cable stroke S during the release state abnormality determination process. As shown,
At time t1, the ignition switch 76 is turned on and the slow forward rotation drive of the electric motor 42 is started. This electric motor 4
Although the cable stroke S changes with the driving of No. 2, the cable tension T hardly changes until the time t2 when the so-called rattling is finished. Current I applied to the electric motor 42
Is a threshold value Iref and the cable tension T reaches the value Tref at time t3, the electric motor 42 is controlled to the slow reverse rotation drive and is returned to the original released state. At this time, the differential value dI /
dS is calculated, and the calculated differential value dI / dS is the threshold R
1 is compared with the threshold value R2 to determine the abnormality of the cable 26. When returning to the original release state, the cable tension T
Changes with the forward rotation of the electric motor 42, but the cable stroke S does not change until time t4 due to hysteresis. In addition, during the time t5 to time t6 when the cable tension T does not change at the approximate value 0, the cable stroke S
Keeps changing due to hysteresis. In this way, when the current I applied to the electric motor 42 and the cable stroke S have a stable and linear relationship, the abnormality of the cable 26 is determined, so that an unnecessary cable tension T is not generated. Therefore, the abnormality of the cable 26 can be detected in a range that does not significantly affect the released state of the parking brake.

The electric parking brake device 20 of the embodiment for executing the above-described starting cable abnormality determination processing routine.
According to the above, according to the variation of the current I applied to the electric motor 42 and the variation of the cable stroke S, the cable 26
The abnormality of can be determined. Moreover, when the parking brake is in the operating state, the abnormality of the cable 26 can be determined without significantly affecting the operating state of the parking brake. Further, when the parking brake is in the released state, the abnormality of the cable 26 can be determined without significantly affecting the released state of the parking brake. Further, the electric motor 4 when determining the abnormality of the cable 26
Since the driving speed of No. 2 is set to be slower than the operation speed during normal operation or release, it is possible to minimize the influence on the state of the parking brake when the abnormality is determined. Furthermore, since the abnormality of the cable 26 is determined while the brake pedal 74 is being depressed, the vehicle does not move during the determination.

In the starting cable abnormality determination processing routine executed by the electric parking brake device 20 of the embodiment, the abnormality of the cable 26 is determined based on the variation amount of the current I applied to the electric motor 42 and the variation amount of the cable stroke S. Although determined, the current I applied to the electric motor 42 and the output load F of the electric motor 42 have the predetermined relationship as described above. Therefore, the output load F of the electric motor 42 is directly or indirectly detected to determine the output load F The abnormality of the cable 26 may be determined based on the change amount and the change amount of the cable stroke S.
Furthermore, since the output load F of the electric motor 42 is the cable tension T in the cable 26, the cable tension T is detected directly or indirectly, and the amount of change in the cable tension T and the amount in which the cable stroke S changes the cable 26. The abnormality may be determined.

Further, the electric parking brake device 20 of the embodiment
In the start-up cable abnormality determination routine executed by
When the parking brake is operating, the operation state abnormality determination process is performed to determine the abnormality of the cable 26, and when the parking brake is released, the release state abnormality determination process is performed to determine the abnormality of the cable 26. When the brake is operating, the operating state abnormality determination process is performed to determine the abnormality of the cable 26, but when the parking brake is released, the abnormality of the cable 26 is not determined. When the vehicle is released, the release state abnormality determination process is performed to determine the abnormality of the cable 26, but the abnormality of the cable 26 may not be determined when the parking brake is operated.

Further, the electric parking brake device 2 of the embodiment
In the start-up cable abnormality determination processing routine executed by 0, the electric motor 42 is driven slowly at the time of the abnormality determination of the cable 26. The driving may be performed at a normal driving speed only when returning to the state.

In the electric parking brake system 20 of the embodiment,
Even in the cable abnormality determination processing routine illustrated in FIG.
In the starting cable abnormality determination routine illustrated in
Although the determination output is the display output to the liquid crystal panel 80, a speaker may be provided and the determination output may be performed by audio output from the speaker.

In the electric parking brake system 20 of the embodiment,
The cable abnormality determination processing routine illustrated in FIG. 3 and the start-time cable abnormality determination processing routine illustrated in FIG. 5 are both executed, but only one of them may be executed.

Although the embodiments of the present invention have been described with reference to the embodiments, the present invention is not limited to the embodiments and various embodiments are possible without departing from the gist of the present invention. Of course, it can be implemented in.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a configuration of an electric parking brake device 20 which is an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a configuration of a cable winding unit 30.

FIG. 3 is a flowchart showing an example of a first operation switch abnormality detection processing routine executed by the electronic control unit 50 in the electric parking brake system 20 of the embodiment.

FIG. 4 is an explanatory diagram showing an example of a relationship between a normal cable stroke S, an extended cable stroke S, and an output load F.

FIG. 5 is a flowchart showing an example of a start-time cable abnormality determination processing routine executed by the electronic control unit 50 in the electric parking brake device 20 of the embodiment when starting the vehicle.

FIG. 6 is a flowchart showing an example of an operation state abnormality determination processing routine executed by the electronic control unit 50 in the electric parking brake system 20 of the embodiment.

FIG. 7 is a flowchart showing an example of a release state abnormality determination processing routine executed by the electronic control unit 50 in the electric parking brake system 20 of the embodiment.

8 is an explanatory diagram showing an example of a relationship between a current I applied to the electric motor 42 and a cable stroke S. FIG.

FIG. 9 is an explanatory diagram showing an example of a relationship between a current I applied to the electric motor 42 and a cable stroke S and an abnormal region thereof.

FIG. 10 is an explanatory diagram showing an example of the operation of the electric motor 42, the change in the cable tension T, and the change in the cable stroke S during the operating state abnormality determination process.

FIG. 11 is an explanatory diagram showing an example of the operation of the electric motor 42, the change in the cable tension T, and the change in the cable stroke S during the release state abnormality determination process.

[Explanation of symbols]

12,14 Rear wheels, 20 Electric parking brake device, 2
2,24 Parking brake unit, 26 cable, 2
7 length adjusting member, 28 bolts, 30 cable winding unit, 32 cable winding mechanism, 34 drive gear, 36 rotation speed adjusting gear, 38 worm gear,
40 winding gear, 42 electric motor, 50 electronic control unit, 52 CPU, 54 ROM, 56 RAM, 6
0 rotation angle sensor, 61 current sensor, 62, 64 wheel speed sensor, 66 operation switch, 70 shift lever, 71 shift position sensor, 72 accelerator pedal, 73 accelerator pedal position sensor, 74
Brake pedal, 75 brake pedal position sensor, 76 ignition switch, 80 LCD panel.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shingo Urababa, Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References JP-A-8-230660 (JP, A) JP-A-11- 170991 (JP, A) Actual development 63-189874 (JP, U) Actual development 59-78162 (JP, U) Actual development 56-113064 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60T 17/22 B60T 7/12

Claims (10)

(57) [Claims] 1. An electric parking brake device having an electric hoisting device capable of hoisting a parking brake cable to actuate the parking brake, the hoisting force detecting device detecting a hoisting force of the electric hoisting device; A winding amount detecting means for detecting the winding amount of the cable wound by the winding means, and an abnormality of the parking brake is detected based on the detected winding amount and the winding force detected by the winding force detecting means. An electric parking brake device comprising an abnormality detecting means. 2. The electric parking brake system according to claim 1, wherein the hoisting force detecting means is means for detecting the hoisting force based on electric power supplied to the electric hoisting means. 3. The electric parking brake device according to claim 1, wherein the electric hoisting means has a hoisting portion that hoists the cable by rotation, and the hoisting amount detecting means is provided for the electric hoisting means. An electric parking brake device which is means for detecting the amount of winding based on the rotation of the winding portion. 4. The abnormality detecting means is means for detecting an abnormality based on the detected change amount of the hoisting force and the detected change amount of the hoisting amount.
The electric parking brake device according to any one of the above. 5. The electric hoist when the parking brake is not operating, the electric hoist within a range until a braking force of a predetermined braking force or less is applied to the parking brake when the electric hoist is wound. The electric parking brake system according to any one of claims 1 to 4, which is a means for drivingly controlling the means to detect the abnormality. 6. The electrically-operated hoisting means within the range in which the braking force of the parking brake does not change by a predetermined braking force or more due to hoisting or rewinding by the electric hoisting means when the parking brake is operating. 2. A means for drivingly controlling a motor to detect the abnormality.
The electric parking brake device according to any one of 1 to 4. 7. The electric motor according to claim 5, wherein the abnormality detecting means is a means for detecting the abnormality by driving the electric hoisting means at a speed lower than a driving speed at the time of operating or releasing the parking brake. Parking brake device. 8. The electric parking brake device according to any one of claims 1 to 7, a brake pedal depression detection means for detecting that the brake pedal is depressed, the abnormality detecting means, the brake pedal An electric parking brake device, which is means for detecting the abnormality while detecting that the brake pedal is being depressed by the depression detecting means. Wherein said abnormality detection means, the electric parking brake system according to any one the claims 1 is means for detecting an abnormality of the slack in the cable 8. 10. The electric parking brake system according to any one of claims 1 to 9, further comprising output means for outputting the abnormality when the abnormality detecting means detects the abnormality.