JP2017024507A - Electric parking brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric parking brake device capable of achieving high reliability at low cost.SOLUTION: An electric parking brake device comprises: a paring brake switch 1 operated by a driver; a controller 2 for activating/releasing a parking brake on the basis of an operation position of the parking brake switch 1. The parking bake switch 1 comprises: an actuation operation detection switch 10 having two actuation operation detection switch contacts 10a, 10b, which are switched at a parking brake actuation operation by a driver; and a release operation detection switch 11 having two release operation detection switch contacts 11a, 11b, which are switched at a parking brake release operation by the driver. The four switch contacts 10a, 10b, 11a, 11b are wired in series.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric parking brake device.

  In Patent Document 1, for the purpose of detecting a failure of a switch for operating an electric parking brake device and avoiding erroneous recognition of an operation position, the inside of the switch is separated into two systems each having two electrodes, and two two-pole double throw switches are provided. In other words, each system is further divided into three paths, and a rectifier element is arranged between the two electrodes so that a detection current flows bidirectionally or unidirectionally between the two electrodes.

European Patent No. 2217475

However, in the above prior art, the internal structure of the switch is complicated, and there are problems in terms of cost and reliability.
An object of the present invention is to provide an electric parking brake device that can realize high reliability at low cost.

  In the present invention, the two actuation operation detection switch contacts that are switched when the driver operates the parking brake and the two release operation detection switch contacts that are switched when the driver releases the parking brake are wired in series.

  Therefore, high reliability can be realized at low cost.

It is a block diagram of the electric parking brake device of Example 1. It is a figure which shows the state of each switch contact 10a, 10b, 11a, 11b and each electrode 7a, 7b, 7c, 7d when the parking brake switch 1 is in a neutral state. It is a figure which shows the state of each switch contact 10a, 10b, 11a, 11b and each electrode 7a, 7b, 7c, 7d when the parking brake switch 1 is pushed to the operation side. It is a figure which shows the state of each switch contact 10a, 10b, 11a, 11b and each electrode 7a, 7b, 7c, 7d when the parking brake switch 1 is pushed to the cancellation | release side. 2 is a configuration diagram of a controller 2. FIG. 10 is a flowchart showing a flow of update processing of SW_POS_Status used for switch operation position determination of the calculation unit 17. 7 is a flowchart showing a flow of a switch operation position and switch failure determination process of a calculation unit 17. It is a figure which shows the state of each switch contact 10a, 10b, 11a, 11b and each electrode 7a, 7b, 7c, 7d when the 1st electrode 7a is disconnected as a typical switch failure. It is a figure which shows the state of each switch contact 10a, 10b, 11a, 11b and each electrode 7a, 7b, 7c, 7d when the 1st operation operation detection switch contact 10a is fixed open as a typical switch failure. It is a figure which shows the failure judgment result based on the combination pattern of each detection signal when a typical switch failure generate | occur | produces.

[Example 1]
FIG. 1 is a configuration diagram of the electric parking brake device of the first embodiment.
The electric parking brake device according to the first embodiment is mounted on a vehicle and includes a parking brake switch 1, a controller 2, left and right electric actuators 3 and 4, and a warning lamp 15. The parking brake switch 1 includes an operation unit 5 and a circuit unit 6. The operation unit 5 is a momentary operation type switch that can be pressed from the neutral state to the operation side and the release side by a driver's pressing operation. The circuit unit 6 outputs a signal corresponding to the state of the operation unit 5 to the controller 2. The controller 2 determines the switch operation position based on the signal from the parking brake switch 1, drives the left and right electric actuators 3 and 4 of the left and right rear calipers according to the determined switch operation position, and operates / releases the parking brake. Do. Further, the controller 2 determines whether or not the parking brake switch 1 has failed based on a signal from the parking brake switch 1, and turns on the warning lamp 15 when determining that there is a failure.
The circuit unit 6 includes four electrodes 7a, 7b, 7c, and 7d, an operation detection switch 10 and a release operation detection switch 11. Each electrode 7a, 7b, 7c, 7d is connected to the controller 2 by an electric signal line.

The operation operation detection switch 10 is a two-pole single-throw switch having a first operation operation detection switch contact 10a and a second operation operation detection switch contact 10b. Both switch contacts 10a and 10b are normally closed. Contact (B contact). The release operation detection switch 11 is a two-pole single-throw switch having a first release operation detection switch contact 11a and a second release operation detection switch contact 11b. Both switch contacts 11a and 11b are normally closed. Contact (B contact).
Each switch contact 10a, 10b, 11a, 11b is connected to a first circuit 7 connecting the first electrode 7a and the fourth electrode 7d, on the first release operation detection switch contact 11a, for detecting the first actuation operation. The switch contact 10a, the second release operation detection switch contact 11b, and the second actuation operation detection switch contact 10b are arranged in this order. The first electrode 7a is connected to the first release operation detection switch contact 11a. The second electrode 7b is connected via a connection portion between the first release operation detection switch contact 11a and the first actuation operation detection switch contact 10a. The third electrode 7c is connected via a connection portion between the second release operation detection switch contact 11b and the second actuation operation detection switch contact 10b. The fourth electrode 7d is connected to the second actuation operation detection switch contact 10b.

Hereinafter, the switch contacts 10a, 10b, 11a, 11b and the electric powers 7a, 7b, 7c during non-operation, operation operation, and release operation when the parking brake switch 1 is operating normally (when normal) The state of 7d will be described.
(Non-operation)
FIG. 2 shows each switch contact 10a, 10b, 11a, 11b and each electrode when the driver is not operating the parking brake switch 1 (operation unit 5), that is, when the operation unit 5 is in a neutral state (neutral). It is a figure which shows the state of 7a, 7b, 7c, 7d. When the parking brake switch 1 is in the neutral position, as shown in FIG. 2 (a), the operation operation detection switch 10 and the release operation detection switch 11 are both OFF, and all the switch contacts 10a, 10b, 11a, 11b is closed. Therefore, as shown in FIG. 2B, all the electrodes 7a, 7b, 7c, 7d are in a short-circuited state.
(During operation)
FIG. 3 shows the switch contacts 10a, 10b, 11a, 11b and the electrodes 7a, 7b when the driver operates the parking brake switch 1 to the operating side, that is, when the operating unit 5 is pushed to the operating side. , 7c, 7d. When the parking brake switch 1 is operated to the operating position, as shown in FIG. 3 (a), the operating operation detection switch 10 is turned ON, the first operating operation detection switch contact 10a and the second operating operation. The detection switch contact 10b is opened. Therefore, as shown in FIG. 3B, the first electrode 7a and the second electrode 7b are short-circuited.
(Unlocking operation)
FIG. 4 shows the switch contacts 10a, 10b, 11a, 11b and the electrodes 7a, 7b when the driver operates the parking brake switch 1 to the release side, that is, when the operation unit 5 is pushed to the release side. , 7c, 7d. When the parking brake switch 1 is operated to the release position, as shown in FIG. 4 (a), the release operation detection switch 11 is turned on, the first release operation detection switch contact 11a and the second release operation. The detection switch contact 11b is opened. Therefore, as shown in FIG. 4B, the third electrode 7c and the fourth electrode 7d are short-circuited.

FIG. 5 is a configuration diagram of the controller 2. The controller 2 includes a switch operation position determination unit 8 that determines the switch operation position of the parking brake switch 1. The switch operation position determination unit 8 includes a calculation unit 17 and a bias voltage application switching unit 23. The computing unit 17 outputs a command signal Vt for alternately switching the connection destination of the bias power source Vbs to the bias voltage application switching unit 23 at a constant period. The computing unit 17 measures the voltages V1 (first voltage) and V2 (second voltage) of the second electrode 7b and the third electrode 7c. The bias voltage application switching unit 23 switches the connection destination of the bias power source Vbs to one of the first electrode 7a and the fourth electrode 7d in accordance with the command signal Vt from the calculation unit 17. When the command signal Vt is 0, the connection destination of the bias power source Vbs is switched to the first electrode 7a as shown in FIG. 5A, and when the command signal Vt is 1, it is shown in FIG. Thus, the connection destination of the bias power source Vbs is switched to the fourth electrode 7d. The bias voltage application switching unit 23 is connected to the first electrode 7a and the fourth electrode 7d via resistors 24a and 24d. The controller 2 is connected to the second electrode 7b and the third electrode 7c via the digital conversion units 25a and 25b and the resistors 24b and 24c. Pull-down resistors 24e and 24f are provided between the digital conversion units 25a and 25b and the resistors 24b and 24c. Each of the resistors 24a, 24b, 24c, and 24d has an effect of limiting the current consumption of the bias power source Vbs, and has a function of preventing abnormal heating or damage due to overcurrent even if any failure occurs. Each of the digital converters 25a and 25b has a function of converting the output signals of the second electrode 7b and the third electrode 7c so that the arithmetic unit 17 can reliably determine the level (for example, a Schmitt trigger circuit having hysteresis) ).
The arithmetic unit 17 detects the V1 voltage level V10 and the V2 voltage level V20 detected while supplying the bias power source Vbs to the first electrode 7a, and while supplying the bias power source Vbs to the fourth electrode 7d. Based on the combination pattern of a total of four values (each detection signal) of the V1 voltage level V11 and the V2 voltage level V21 detected in step 1, the switch operating position and the presence or absence of a switch failure are determined. Here, the switch failure includes disconnection between the parking brake switch 1 and the controller 2, disconnection of each electrode 7a, 7b, 7c, 7d, fixation of each switch contact 10a, 10b, 11a, 11b, and the like.

FIG. 6 is a flowchart showing the flow of the update process of SW_POS_Status used for the switch operation position determination of the calculation unit 17.
In step S1, the SW_POS_Status value that is the determination value of the current switch operation position is set to each value of SW0, SW1, and SW2.
In step S2, the update permission counter value Tc is set to zero. The update permission counter value Tc is allowed to be updated only when the same judgment result is repeated a predetermined number of times (10 times) so that the SW_POS_Status is not mistakenly updated when the level changes due to the influence of noise etc. on the switch signal. It is a counter value for
In step S3, Vt is set to 0.
In step S4, it is determined whether Vt is 0. If YES, the process proceeds to step S5. If NO, the process proceeds to step S7.
In step S5, V10 is set to V1, and V20 is set to V2.
In step S6, Vt is set to 1.
In step S7, V11 is set to V1, and V21 is set to V2.

In step S8, the switch operation position is determined from the combination pattern of the detection signals V10, V11, V20, and V21, and is set as the SW1 value. In this step, when all the values are high, the neutral position is determined, when V10 is high and the remaining three are low, the operation position is determined, and when V21 is high and the remaining three are low, the determination is the release position.
In step S9, it is determined whether SW1 is SW0. If YES, the process proceeds to step S1, and if NO, the process proceeds to S10. In this step, if SW1 (current value) is the same as the SW0 value (previous value), it is determined that there is no operation, and if it is different, it is determined that there is an operation.
In step S10, it is determined whether SW1 is SW2. If YES, the process proceeds to step S11, and if NO, the process proceeds to step S14. In this step, if SW1 (current value) is the same as SW2 (update candidate value), the same operation continues. If it is different, a different operation is performed (for example, the judgment value of the current switch operation position is neutral ⇒ momentary Operation to the operating side ⇒ Operation to the releasing side).
In step S11, it is determined whether Tc is 10 or more. If YES, the process proceeds to step S12. If NO, the process proceeds to step S13.
In step S12, the SW1 value is set to the SW_POS_Status value. As a result, the SW_POS_Status value is updated.
In step S13, Tc is counted up.
In step S14, the SW1 value is set to the SW2 value. In this step, SW1 (current value) is set to SW2 (update candidate value) because a different operation was performed during the update determination.
In step S15, Tc is set to 0.

FIG. 7 is a flowchart showing the flow of the switch operation position and switch failure determination process of the calculation unit 17.
In step S21, both the update permission counter value Pc and the fail counter value Fc are set to 0. The update permission counter value Pc is a counter value for setting a time interval for updating the manual operation information Current_SW_POS recognized by the system based on the contents of SW_POS_Status, and functions as a filter for avoiding erroneous determination of the manual operation information. . The fail counter value Fc is a counter value for setting a time interval for determining a failure.
In step S22, it is determined whether SW_POS_Status is a neutral position (Neutral). If YES, the process proceeds to step S23, and if NO, the process proceeds to step S27.
In step S23, it is determined whether Current_SW_POS is a neutral position. If YES, the process proceeds to step S21, and if NO, the process proceeds to step S24.
In step S24, Pc is counted up.
In step S25, it is determined whether Pc is 10 or more. If YES, the process proceeds to step S26, and if NO, the process proceeds to step S22.
In step S26, Current_SW_POS is set to the neutral position.
In step S27, it is determined whether SW_POS_Status is the operating position (Apply). If YES, the process proceeds to step S28, and if NO, the process proceeds to step S32.

In step S28, it is determined whether Current_SW_POS is the operating position. If YES, the process proceeds to step S21. If NO, the process proceeds to step S29.
In step S29, Pc is counted up.
In step S30, it is determined whether Pc is 10 or more. If YES, the process proceeds to step S31. If NO, the process proceeds to step S22.
In step S31, Current_SW_POS is set as the operating position.
In step S32, it is determined whether SW_POS_Status is a release position (Release). If YES, the process proceeds to step S33, and if NO, the process proceeds to step S37.
In step S33, it is determined whether Current_SW_POS is a release position. If YES, the process proceeds to step S21, and if NO, the process proceeds to step S34.
In step S34, Pc is counted up.
In step S35, it is determined whether Pc is 10 or more. If YES, the process proceeds to step S36, and if NO, the process proceeds to step S22.
In step S36, Current_SW_POS is set as a release position.
In step S37, Current_SW_POS is set to the neutral position.
In step S38, Pc is set to 0 and Fc is counted up. Since it is difficult to properly determine the switch operation position during the fail count (while Fc is counted up), it is determined that the switch is not being operated, and an unintended operation and release operation are avoided.
In step S39, it is determined whether Fc is 100 or more. If YES, the process proceeds to step S40, and if NO, the process proceeds to step S22.
In step S40, the switch failure is confirmed and the warning lamp 15 is turned on.

In the electric parking brake device, it is important to avoid erroneous recognition of the switch operation position at the time of normal operation and at the time of a switch failure in order to prevent the operation and release of the parking brake not intended by the driver. It is also important to detect a switch failure and notify the driver for the purpose of prompting the driver to repair. When the driver tries to activate the parking brake without noticing the notification, it is preferable to warn the driver that the parking brake is not activated. For this purpose, it is necessary to detect the actuation operation during a switch failure. By satisfying these three requirements (1. Avoiding misrecognition of switch operation position, 2. Detection of switch failure, 3. Detection of operation operation during switch failure), a highly reliable electric parking brake device can be realized. .
The conventional electric parking brake device satisfies the above three requirements using a switch connected to the controller via four electrodes. In this prior art, the inside of the switch is separated into two systems each having two electrodes, each system is further separated into three paths using two two-pole double throw switches, and the three paths are arranged between the two electrodes. The rectifying element is arranged so that the detection current flows bidirectionally or unidirectionally between the electrodes. However, in this prior art, the structure inside the switch is complicated, and there is a problem in terms of cost. In addition, since the complexity of the structure increases the failure rate, there is a problem in terms of reliability.

Here, in a switch using four electrodes, in order to satisfy the above three requirements, even if one of the four electrodes is disconnected, the remaining three will satisfy the three requirements, and four Even if two of these electrodes are short-circuited, it is necessary to satisfy the three requirements. In a simple switch configuration that does not use complicated circuits and rectifiers, etc., only open / short between four electrodes can be switched, and the open / short state between electrodes during switch operation when no switch failure occurs. It is difficult to identify the difference between the open / short state between the electrodes when a switch failure occurs.
On the other hand, in the electric parking brake device of the first embodiment, two release operation detection switch contacts 10a, 10b of the operation operation detection switch 10 and two release operation detection switch contacts 11a, 11b are alternately arranged on the series circuit 9. As a result, the open / short state between the electrodes 7a, 7b, 7c, and 7d during normal operation differs in two positions between the switch operating positions, so one electrode is disconnected or two are short-circuited. Even so, the open / short state between the electrodes can be made different between the switch operating positions. That is, the above three requirements can be satisfied with a combination of simple switches (two-pole single-throw switches) without using complicated circuits or rectifying elements.
On the other hand, the controller 2 detects the detection signal (voltage levels V10 and V20 of the second electrode 7b and the third electrode 7c) when the bias power source Vbs is connected to the first electrode 7a, and biases the fourth electrode 7d. Based on the combination pattern with the detection signal (voltage levels V11 and V21 of the second electrode 7b and the third electrode 7c) when the power source Vbs is connected, the switch operation position and the switch failure are detected. As a result, the number of electrodes can be minimized and the structure can be simplified, so that the failure rate can be further reduced.
Therefore, in the electric parking brake device of the first embodiment, an electric parking brake device with a low cost and a low failure rate can be realized with a simple combination of switches without using a complicated circuit or a rectifying element.

The failure judgment result when a typical switch failure occurs is shown below.
(When electrode 7a is disconnected)
FIG. 8 is a diagram showing the states of the switch contacts 10a, 10b, 11a, 11b and the electrodes 7a, 7b, 7c, 7d when the first electrode 7a is disconnected. When the first electrode 7a is disconnected, the three electrodes 7b, 7c, 7d except for the first electrode 7a are short-circuited during non-operation, and all the electrodes 7a, 7b, 7c, 7d are open during operation. It becomes a state. As shown in FIG. 10, the combination pattern (failure pattern A) of each detection signal during non-operation is Low, High, Low, High, and the combination pattern (High, High, High, High) of each detection signal at normal time And different. Further, the combination pattern (failure pattern B) of each detection signal during the operation is Low, Low, Low, Low, which is different from the combination pattern (High, Low, Low, Low) of each detection signal in the normal state. Therefore, the calculation unit 17 can determine that a switch failure has occurred.
Also, failure pattern A is different from the combination pattern of each detection signal during normal operation and release operation, and failure pattern B is the combination pattern of each detection signal during non-operation and release operation at normal time. Is different. Therefore, it is possible to prevent the operation and release of the parking brake not intended by the driver due to erroneous determination of the switch operation position.
Furthermore, since the combination patterns of the detection signals of the failure pattern A and the failure pattern B are different, the calculation unit 17 can detect that the driver has operated the parking brake switch 1 to the operating side. Therefore, after the switch failure is detected and the warning lamp 15 is turned on, if the driver operates the parking brake switch 1 to the operating side, the warning lamp 15 is switched from the lighting state to the blinking state or an alarm sound is sounded. It is possible to notify the driver that the operation cannot be accepted and to bring it into a dealer or a service factory.

(When switch contact 10a is fixed open)
FIG. 9 is a diagram showing the states of the switch contacts 10a, 10b, 11a, 11b and the electrodes 7a, 7b, 7c, 7d when the first actuation operation detection switch contact 10a is fixed open. When the first operating operation detection switch contact 10a is fixed open, the first electrode 7a and the second electrode 7b are short-circuited during non-operation, and the third electrode 7c and the fourth electrode 7d are connected. Short circuit. As shown in FIG. 10, the combination pattern (failure pattern C) of each detection signal in the failure pattern C is High, Low, Low, and High, and is different from the combination pattern of each detection signal in the normal state. Therefore, the calculation unit 17 can determine that a switch failure has occurred.
In addition, since the failure pattern C is different from the combination pattern of detection signals during normal operation and release operation, it is possible to prevent the driver from unintentionally operating and releasing the parking brake due to erroneous determination of the switch operation position. .
Furthermore, since the combination pattern of the detection pattern during the operation operation at normal time and the failure pattern C are different from each other, the calculation unit 17 can detect that the driver has operated the parking brake switch 1 to the operation side. Therefore, after the switch failure is detected and the warning lamp 15 is turned on, if the driver operates the parking brake switch 1 to the operating side, the warning lamp 15 is switched from the lighting state to the blinking state or an alarm sound is sounded. It is possible to notify the driver that the operation cannot be accepted and to bring it into a dealer or a service factory.
In addition, for reasons of space, the failure determination result when a switch failure other than the above two examples that can be considered occurs is not described, but as in the above two examples, the calculation unit 17 avoids erroneous recognition of the switch operation position, It is possible to detect a fault and an operating operation during a switch fault.

In Example 1, the following effects are exhibited.
(1) An electric parking brake device including a parking brake switch 1 operated by a driver and a controller 2 that activates and releases the parking brake based on an operation position of the parking brake switch 1, wherein the parking brake switch 1 , An operation detection switch 10 having two operation operation detection switch contacts 10a and 10b that are switched when the driver operates the parking brake, and two release operation detection switch contacts 11a that are switched when the driver releases the parking brake. The release operation detection switch 11 having 11b is provided, and the four switch contacts 10a, 10b, 11a, 11b are wired in series.
Therefore, based on the state of the four switch contacts 10a, 10b, 10c, and 10d, it is possible to avoid erroneous recognition of the switch operation position, detect switch failure, and detect operation operation during switch failure. High reliability can be realized.
(2) The four switch contacts 10a, 10b, 11a, and 11b are a first release operation detection switch contact 11a, a first actuation operation detection switch contact 10a, a second release operation detection switch contact 11b, The second actuation operation detection switch contact 10b is wired in this order.
Accordingly, the voltage levels of the first release operation detection switch contact 10a and the second release operation detection switch contact 11b when the bias power source Vbs is connected to the first release operation detection switch contact 11a, Switch operation based on the combination pattern of the voltage levels of the first release operation detection switch contact 10a and the second release operation detection switch contact 11b when the bias power source Vbs is connected to the operation operation detection switch contact 10b. It is possible to avoid misrecognition of a position, detect a switch failure, and detect an operation during a switch failure.

(3) The parking brake switch 1 includes four electrodes 7a, 7b, 7c, and 7d individually connected to the controller 2, and the first electrode 7a is connected to the first release operation detection switch contact 11a. The second electrode 7b is connected to the connection portion between the first release operation detection switch contact 11a and the first actuation operation detection switch contact 10a, and the third electrode 7c is connected to the second release operation detection switch contact 10a. The switch contact 11b for detection and the connection part of the switch contact 10b for detection of the second operation operation are connected. The fourth electrode 7d is connected to the switch contact 10b for detection of the second operation operation. The voltage V10 of the second electrode 7b and the voltage V20 of the third electrode 7c when the bias power supply Vbs is connected to the first electrode 7a, and the second electrode when the bias power supply Vbs is connected to the fourth electrode 7d Based on the voltage V11 of 7b and the voltage V21 of the third electrode 7c, the state of the parking brake switch 1 is detected.
ing.
Therefore, since the number of electrodes can be minimized and the structure can be simplified, the failure rate can be reduced and the reliability can be improved.

[Other Examples]
As mentioned above, although the form for implementing this invention was demonstrated based on Example 1, the specific structure of this invention is not limited to the structure shown in Example 1, and does not deviate from the summary of invention. Any change in the design of the range is included in the present invention.
For example, in the first embodiment, the actuation operation detection switch and the release operation detection switch are two-pole single-throw switches, but a two-pole double-throw switch may be used.
In the first embodiment, all switch contacts are normally closed contacts (B contacts), but all may be normally open contacts (A contacts), or one or more may be normally closed contacts.

Vbs bias power supply
1 Parking brake switch (switch)
2 Controller
7a First electrode
7b Second electrode
7c Third electrode
7d 4th electrode
8 Switch operation position judgment section
9 Series circuit
10 Switch for detecting operation
10a Switch contact for detecting first operation
10b Switch contact for second operation detection
11 Release operation detection switch
11a Switch contact for detecting first release operation
11b Switch contact for second release operation detection
15 Warning light
17 Calculation unit
23 Bias voltage application switching section
24a, 24b, 24c resistance
24e, 24f pull-down resistor
25a, 25b Digital converter

Claims (3)

An electric parking brake device comprising a switch operated by a driver, and a controller that activates and releases a parking brake based on an operation position of the switch,
The switch is
An operation detection switch having two operation detection switch contacts that are switched when the driver operates the parking brake;
A release operation detection switch having two release operation detection switch contacts which are switched when the driver releases the parking brake;
With
The electric parking brake device, wherein the four switch contacts are wired in series. In the electric parking brake device according to claim 1,
The four switch contacts are arranged in the order of a first release operation detection switch contact, a first actuation operation detection switch contact, a second release operation detection switch contact, and a second actuation operation detection switch contact. Electric parking brake device characterized by being made. The electric parking brake device according to claim 2,
The switch comprises four electrodes individually connected to the controller,
The first electrode is connected to the first release operation detection switch contact,
The second electrode is connected to a connection portion between the first release operation detection switch contact and the first actuation operation detection switch contact,
The third electrode is connected to a connection portion between the second release operation detection switch contact and the second actuation operation detection switch contact,
The fourth electrode is connected to the second actuation operation detection switch contact,
The controller includes a voltage of the second electrode and a voltage of the third electrode when a power source is connected to the first electrode, and a second voltage when the power source is connected to the fourth electrode. An electric parking brake device that detects a state of the switch based on a voltage of an electrode and a voltage of the third electrode.

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