JP3509700B2 - 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 that operates a parking brake by an electric drive means based on an operation of an operating member.

[0002]

2. Description of the Related Art Conventionally, as an electric parking brake device of this type, there has been proposed a device which operates a parking brake by a cable pulling force proportional to the hydraulic pressure of a foot brake (for example, Japanese Patent Laid-Open No. 5-139269). ). In this device, the load due to the hydraulic pressure of the foot brake is superposed on the spring spring in which a predetermined load is set as the pulling force of the cable of the parking brake. With this configuration, the required braking force of the parking brake is variable based on the stopped state of the vehicle, that is, whether the vehicle is stopped on a flat road or on a slope.

[0003]

However, such an electric parking brake device may not be suitable for operating the parking brake as a backup of the hydraulic brake when the vehicle is traveling. That is, this electric parking brake device is one of those suitable for maintaining the state where the vehicle is stopped, but when the parking brake is operated while the vehicle is traveling, a sudden braking force is applied. There is a case to do. The sudden action of the braking force is not preferable in terms of vehicle behavior.

One object of the electric parking brake device of the present invention is to control the parking brake so that an appropriate braking force can be obtained according to the running state of the vehicle. Another object of the electric parking brake device of the present invention is to control the parking brake so that the braking force intended by the occupant can be obtained. Another object of the electric parking brake device of the present invention is to prevent a reduction in riding comfort of an occupant.

[0005]

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 for operating a parking brake by an electric drive means based on an operation of an operation member, the travel detection means for detecting travel of a vehicle, and the operation member of the operation member when travel of the vehicle is detected. When the operation is performed, a control means for driving and controlling the electric drive means so as to control the braking force of the parking brake based on the traveling of the vehicle.

In the first electric parking brake device of the present invention, if the operation member is operated while the traveling of the vehicle is detected by the traveling detection means, the control means causes the parking brake based on the traveling of the vehicle. Control the braking force of.
As a result, a braking force according to the running of the vehicle can be applied from the parking brake.

In the first electric parking brake device of the present invention, the traveling detecting means is means for detecting the traveling speed of the vehicle, and the control means is based on the traveling speed detected by the traveling detecting means. It is a means for controlling the braking force of the parking brake. With this, the braking force of the parking brake can be controlled based on the traveling speed of the vehicle.

In the first electric parking brake device of the present invention in which the traveling detection means detects the traveling speed, the control means reduces the braking force of the parking brake as the detected traveling speed increases. It is a means of controlling. With this, the parking brake can apply a braking force according to the traveling of the vehicle. In addition, "the higher the traveling speed, the smaller the braking force of the parking brake" is,
In addition to the relationship that changes smoothly and continuously, the relationship that changes gradually and the relationship that changes only partially are also included.

Further, in the first electric parking brake system of the present invention in which the traveling detecting means detects the traveling speed,
The control means may be a means for controlling the electric drive means such that the increasing gradient of the braking force of the parking brake becomes smaller as the detected traveling speed becomes higher. With this, the parking brake can apply a braking force according to the traveling of the vehicle. It should be noted that "the higher the traveling speed, the smaller the gradient of the increase in the braking force of the parking brake" includes not only the continuously smoothly changing relationship but also the gradually changing relationship and a partially changing relationship. .

Further, in the first electric parking brake device of the present invention, the operating member is a member capable of instructing the magnitude of the braking force of the parking brake, and the control means controls the braking force of the parking brake. It may be a means for controlling the size to be instructed by the operating member. In this way, the braking force of the parking brake can be controlled to the magnitude intended by the occupant.

In the first electric parking brake device of the present invention, the electric drive means is a means including an electric motor, and the control means is means for controlling the braking force of the parking brake by duty control of the electric motor. It can also be. In this way, the braking force of the parking brake can be controlled by controlling the duty of the electric motor. In the first electric parking brake device of the present invention of this aspect, a state detection means for detecting the state of the vehicle is provided,
The control means may be means for performing duty control of the electric motor based on the state detected by the state detection means. In this way, control can be performed based on the state of the vehicle. Here, the "vehicle state" includes the traveling speed of the vehicle, the operating state of the operating member, the inclination angle of the vehicle, the vehicle weight, the temperature of the electric motor of the electric drive means, and the like.

Further, in the first electric parking brake device of the present invention, the operating member is a member capable of instructing to release the braking force of the parking brake, and the control means controls the parking brake by the operating member. It may be a means for driving and controlling the electric drive means so that the braking force of the parking brake is released when an instruction to release the power is given. In this way, the braking force of the parking brake can be released when the occupant intends.

[0014]

[0015]

[0016]

[0017]

[0018]

The first electric parking brake device of the present invention including these aspects may be provided with display means for displaying the degree of the braking force of the parking brake. This allows the occupant to know the degree of the braking force of the parking brake.

[0020]

Other Embodiments of the Invention In addition to the above-described aspects, the present invention can also take the following aspects.

In the first electric parking brake device of the present invention according to any one of the above-mentioned aspects, there is provided lock state detecting means for detecting a lock state of the wheel on which the braking force of the parking brake acts, and the control means. It may be a means for controlling the braking force of the parking brake so that the locked state is released when the locked state of the wheel is detected by the locked state detecting means. In this way, it is possible to prevent the wheels from becoming locked.

[0022]

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.

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.
When the cable 26 is wound up by the winding gear 40, the tension of the cable 26 causes the parking brake units 22, 24 to move.
Is actuated, and the braking force acts on the left and right rear wheels 12, 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,
Wheel speed sensor 6 attached to the left and right rear wheels 12 and 14
2, 64, wheel speeds Vl and Vr, cable tension T from a tension sensor 66 attached to the cable 26, current applied to the electric motor 42 from an ammeter (not shown) attached to the electric motor 42 of the cable winding unit 30, An on / off signal or the like from an operation switch 70 arranged on a panel in front of the driver's seat and instructing activation and release of a parking brake is input through an input port. Further, the electronic control unit 50 outputs a drive signal to the electric motor 42 and a display signal to an indicator 78 mounted on a panel on the front face of the driver seat and displaying the degree of the braking force of the parking brake through the output port. There is.

Next, the operation of the electric parking brake device 20 of the embodiment thus constructed, particularly the operation when the parking brake is operated while the vehicle is traveling, will be described. Figure 3
Is the electronic control unit 50 when operating the parking brake.
6 is a flowchart showing an example of a processing routine at the time of starting the parking brake operation executed in. This routine is executed when the driver operates the operation switch 70.

When the parking brake operation start process routine is executed, the CPU 52 of the electronic control unit 50 first executes a process of reading the vehicle speed V (step S10).
0). Here, the vehicle speed V may be read from a vehicle speed sensor (not shown) provided in the vehicle, or may be read from the wheel speeds Vl and Vr detected by the wheel speed sensors 62 and 64 by calculation. Next, based on the read vehicle speed V, the target cable tension T *
Is set such that the target cable tension T * decreases as the vehicle speed V increases (step S102). The setting is performed in such a manner that the target cable tension T * is made smaller as the vehicle speed V is higher, and the braking force acting on the left and right rear wheels 12, 14 by the parking brake units 22, 24 is made smaller, so that the occupant is not braked. This is to prevent a strong shock due to the action of. This process, in the example,
The relationship between the vehicle speed V and the target cable tension T * is predetermined and stored in the ROM 54 as a map, and when the vehicle speed V is given, the target cable tension T * corresponding to this vehicle speed V is derived from the map. . FIG. 4 shows an example of a map of the relationship between the vehicle speed V and the target cable tension T *.

Then, a process for setting the target operating speed Vm * of the parking brake units 22, 24 based on the vehicle speed V is performed (step S104). Target operating speed Vm *
Is set to decrease as the vehicle speed V increases. This is because the operating speed of the braking force applied by the parking brake units 22 and 24 becomes slower as the vehicle speed V becomes higher, so that the occupant is not shocked by the sudden action of the braking force. This process, in the example,
The relationship between the vehicle speed V and the target operating speed Vm * of the parking brake units 22 and 24 is determined in advance as a map ROM54.
When the vehicle speed V is given, the target operating speed Vm * corresponding to the vehicle speed V is derived from the map. FIG. 5 shows an example of a map of the relationship between the vehicle speed V and the target operating speed Vm *.

Then, the parking brake units 22, 24
The motor 42 is driven so that the operating speed Vm of the cable operates at the target operating speed Vm * and the cable tension T of the cable 26 becomes the target cable tension T * (step S106), and the indicator 78 is brought into a state corresponding to the target cable tension T *. Is displayed (step S108), and this routine ends. Specifically, the driving process of the electric motor 42 is a process of driving the electric motor 42 at a rotation speed corresponding to the target operating speed Vm * until the cable tension T detected by the tension sensor 66 reaches the target cable tension T *. .

The electric parking brake system 20 of the embodiment for executing the processing routine at the start of the parking brake operation described above.
According to the above, since the target cable tension T * of the cable 26 is set according to the vehicle speed V to drive the electric motor 42, the braking force applied to the left and right rear wheels 12, 14 by the parking brake units 22, 24 is the vehicle speed V. It can be appropriate. Moreover, the target operating speed Vm * of the parking brake units 22 and 24 is set according to the vehicle speed V to set the electric motor 4
Since 2 is driven, it is possible to prevent the sudden action of the braking force and ensure the comfort of the rider. Further, since the target cable tension T *, that is, the cable tension T is displayed on the indicator 78, the driver can know how much braking force is currently being applied to the left and right rear wheels 12, 14 by the parking brake. .

In the electric parking brake device 20 of the embodiment,
The target cable tension T * is set to be smaller as the vehicle speed V becomes higher, and the target operating speed Vm * is set to become smaller as the vehicle speed V becomes higher. However, only one of them may be set.

Next, the control of the parking brake after the operation of the parking brake is started will be described. Figure 6
6 is a flowchart showing an example of a parking brake operating state control routine executed by the electronic control unit 50. This routine is repeatedly executed at predetermined time intervals (for example, every 8 msec) until the parking brake is released or the vehicle stops after the parking brake operation start time processing routine illustrated in FIG. 3 is executed.

When this parking brake operating state control routine is executed, the CPU 52 of the electronic control unit 50
First, the vehicle speed V and the wheel speeds Vl and Vr of the left and right rear wheels 12 and 14
A process of reading and is executed (step S120). Then, it is determined whether any of the left and right rear wheels 12, 14 is in the locked state based on the read wheel speeds Vl, Vr (step S122). If not locked
Check the value of the braking force adjustment flag F (step S12).
8). Here, the braking force adjustment flag F is set when both the left and right rear wheels 12 and 14 are not locked when the parking brake units 22 and 24 are operated with the target cable tension T * set according to the vehicle speed V. The value 0 is set, one of the left and right rear wheels 12, 14 is locked, and the value 1 is set while the target cable tension T * is being adjusted. The setting of the braking force adjustment flag F will be described later. When the braking force adjustment flag F is 0, it is determined that the parking brake units 22 and 24 are operating with the target cable tension T * corresponding to the vehicle speed V without being locked, and this routine is ended.

On the other hand, in step S122, the left and right rear wheels 12,
When any one of 14 is determined to be in the locked state, a value obtained by subtracting the predetermined value ΔT1 from the target cable tension T * is set as a new target cable tension T * (step S12).
4) The value 1 is set to the braking force adjustment flag F (step S126). Then, the electric motor 42 is driven so that the cable tension T of the cable 26 becomes the target cable tension T * (step S138), and the indicator 78 is displayed so as to become the target cable tension T * (step S140).
This routine ends. Thus, the target cable tension T
By lowering * to adjust the cable tension T of the cable 26, the left and right rear wheels 12, 14 can be unlocked. The predetermined value ΔT1 is set for the purpose of releasing the locked state, and the value is set according to the weight of the vehicle or the like.

When the locked state of the left and right rear wheels 12 and 14 is released in this way, in step S122, the left and right rear wheels 1 and 14 are again returned.
It is determined that Nos. 2 and 14 are not in the locked state, and step S1
At 28, the braking force adjustment flag F is checked. At this time, since the braking force adjustment flag F has a value of 1, a predetermined value ΔT2 is added to the target cable tension T * to obtain a new target cable tension T * (step S130). Subsequently, the new target cable tension T * is compared with the target cable tension T * derived from the vehicle speed V (step S132), and when the new target cable tension T * is larger than the value derived from the vehicle speed V, the vehicle speed is increased. The value derived from V is set as the target cable tension T * (step S134), and the braking force adjustment flag F is set to the value 0 (step S136). Then, the electric motor 42 is driven so that the cable tension T of the cable 26 becomes the target cable tension T * (step S13).
8) The indicator 78 is displayed so as to correspond to the target cable tension T * (step S140), and this routine ends. These processes are processes for reducing the cable tension T of the cable 26 to release the lock state and then returning the cable tension T to the target cable tension T * according to the vehicle speed V. Therefore, since the predetermined value Δ2 is set to gradually increase the target cable tension T *, the predetermined value ΔT used when releasing the locked state is set.
It is set as a value smaller than 1. If any of the left and right rear wheels 12 and 14 is locked during the process of returning the target cable tension T * to the value corresponding to the vehicle speed V, the unlocking process (steps S124 and S126) is performed. Needless to say. When the new target cable tension T * is smaller than the value corresponding to the vehicle speed V in step S132, it is determined that the original state has not yet been restored,
The electric motor 42 is driven so that the cable tension T of the cable 26 becomes the target cable tension T * without resetting the braking force adjustment flag F (step S138), and the indicator 78 is displayed so as to correspond to the target cable tension T *. (Step S140), the present routine ends.

FIG. 7 is an explanatory diagram showing an example of the adjustment of the cable tension T when the left and right rear wheels 12, 14 are locked when the parking brake is operated in the vehicle traveling at the vehicle speed V. In the figure, when the locked state of either of the left and right rear wheels 12, 14 is determined at time t1, the target cable tension T * is lowered by a predetermined value ΔT1, the cable tension T is adjusted, and the locked state is released. (Steps S122 to S1
26). The target cable tension T * is gradually increased by a predetermined value ΔT2 so that the target cable tension T * returns to a value corresponding to the vehicle speed V from the time t2 when the lock state is released (steps S130 to S136). .
Then, at time t3, the cable tension T returns to a value corresponding to the vehicle speed V.

According to the electric parking brake device 20 of the embodiment which executes the parking brake operating state control routine described above, either of the left and right rear wheels 12, 14 is operated when the parking brake is operated while the vehicle is traveling. It is possible to avoid the locked state. As a result, the left and right rear wheels 12, 14
It is possible to prevent the vehicle from becoming in a traveling state in which the vehicle is in a stable state due to any one of them being locked.

In the electric parking brake device 20 of the embodiment,
An operation switch 70 as an on / off switch is provided to operate the parking brake, and when the operation switch 70 is turned on, the target cable tension T * is determined based on the vehicle speed V.
Is set and the cable tension T of the cable 26 is adjusted, the operation switch may be provided with a volume function so that the operator adjusts the amount of the braking force of the parking brake. An example of the appearance of the operation switch 70B of this modification is shown in FIG. As shown in the figure, a modified operation switch 70
B is composed of an on / off switch 72 for instructing the operation and release of the parking brake and a volume switch 74 for adjusting the magnitude of the braking force of the parking brake. When the operator wants to operate the parking brake, he or she operates the on / off switch 72 and the volume switch 74 to adjust to a desired braking force. The volume switch 74 is interlocked with the indicator 78, and when the volume switch 74 is operated, the indicator 78 displays the degree of setting of the braking force. Figure 9
4 is a flowchart showing an example of a parking brake operation start time processing routine executed by the electronic control unit 50 when the on / off switch 72 is operated and the braking force is set by the volume switch 74. When this routine is executed, C of the electronic control unit 50 is
The PU 52 reads the operation instruction value S and the vehicle speed V instructed by the volume switch 74 (step S20).
0), based on the read operation instruction value S, the target cable tension T * is set (step S202). Then, the target operating speed Vm * is set based on the vehicle speed V (step S204), the operating speed Vm of the parking brake units 22 and 24 operates at the target operating speed Vm *, and the cable tension T of the cable 26 becomes the target cable tension T. The electric motor 42 is driven so as to be * (step S206), and this routine is ended. Through such processing, the volume switch 74
The braking force of the parking brake can be adjusted to the value instructed by.

According to the modified electric parking brake device including the volume switch 74 described above, the braking force desired by the operator can be applied to the left and right rear wheels 12, 14 from the parking brake.

It should be noted that the braking force adjusting process by the operation switch 70B having the volume switch 74 and the braking force adjusting process based on the vehicle speed V in the embodiment may be combined. That is, when the on / off switch 72 is turned on, the parking brake operation start time processing routine of FIG. 3 is executed to execute the target cable tension T * corresponding to the vehicle speed V.
The cable tension T of the cable 26 is adjusted so that when the volume switch 74 is operated after this process is completed or during this process, the parking brake operation start process routine of FIG. Switch 74
The cable tension T of the cable 26 is adjusted so that the target cable tension T * based on the operation instruction value S is obtained. In this way, the braking force of the parking brake can be adjusted to the magnitude according to the vehicle speed V and also to the magnitude intended by the operator.

Next, the release control of the parking brake in the electric parking brake device 20 of the embodiment and the electric parking brake device of the modified example will be described. The parking brake is released by operating the operation switch 70 while the parking brake is operating. Specifically, this processing is performed by the electronic control unit 50 that has detected the signal from the operation switch 70 by outputting a drive signal to the electric motor 42 so as to reversely rotate the rotor with respect to the rotation direction of the operation of the parking brake. Done. Thus, according to the electric parking brake device of the embodiment and the electric parking brake device of the modified example, the parking brake can be released only by operating the operation switch 70.

In the electric parking brake device 20 of the embodiment and its modification, the tension sensor 66 detects the cable tension T of the cable 26. However, the current value applied to the electric motor 42 and the cable tension T of the cable 26 are detected. It is also possible to previously obtain the relationship with and to detect the cable tension T from this current value.

Next, an electric parking brake device 20B which is a second embodiment of the present invention will be described. FIG. 10 is a configuration diagram showing an outline of the configuration of the electric parking brake device 20B of the second embodiment. As illustrated, the electric parking brake device 20B of the second embodiment has a temperature sensor 80 for detecting the temperature Tm of the electric motor 42, an acceleration of the vehicle, in addition to the configuration of the electric parking brake device 20 of the first embodiment. A G sensor 82 that detects G and a vehicle weight sensor 84 that detects the weight W of the vehicle are provided. The temperature Tm, acceleration G, and weight W of the electric motor 42 detected by these sensors are input to the electronic control unit 50 via an input port.

Next, the operation of the electric parking brake device 20B of the second embodiment thus constructed, particularly the operation when the parking brake is operated while the vehicle is traveling, will be described.
FIG. 11 is a flowchart showing an example of a parking brake operation start time processing routine executed by the electronic control unit 50 of the second embodiment when the parking brake is operated. This routine is executed when the driver operates the operation switch 70.

When the parking brake operation start time processing routine is executed, the CP of the electronic control unit 50 of the second embodiment is
The U52 executes a process of reading the vehicle speed V, the vehicle inclination angle θ, the vehicle weight W, and the temperature Tm of the electric motor 42 (step S300). The reading of the vehicle speed V is as described in the first embodiment. The tilt angle θ of the vehicle may be calculated from the acceleration G detected by the G sensor 82, or may be read from a tilt angle sensor provided. For the weight W of the vehicle, the vehicle weight sensor 8
The value detected by 4 is read, and the temperature T of the electric motor 42 is read.
About m, it is performed by reading the value detected by the temperature sensor 80.

Subsequently, the processing for calculating the duty ratio D of the current applied to the electric motor 42 is executed based on the read vehicle speed V, the vehicle inclination angle θ, the vehicle weight W, and the temperature Tm of the electric motor 42 (step S302). ). The duty ratio D of the current applied to the electric motor 42 has a substantially linear relationship with the torque of the electric motor 42, and the torque of the electric motor 42 has a substantially linear relationship with the tension T of the cable 26. The duty ratio D has a linear relationship with the tension T of the cable 26, that is, the braking force of the parking brake. That is, the braking force of the parking brake can be controlled by controlling the duty ratio D. As for the relationship between the vehicle speed V and the duty ratio D, since the duty ratio D and the tension T of the cable 26 have a substantially linear relationship, the relationship between the vehicle speed V and the cable tension T of FIG. 4 used in the first embodiment. Can be used by converting it into a relationship between the vehicle speed V and the duty ratio D. As the relationship between the vehicle inclination angle θ or the vehicle weight W and the duty ratio D, an example of the relationship between the inclination angle θ or the weight W and the duty ratio D illustrated in FIG. 12 is used, and the temperature Tm of the electric motor 42 and the duty ratio D As the relationship with the ratio D, an example of the relationship between the temperature Tm of the electric motor 42 and the duty ratio D illustrated in FIG. 13 is used. These relationships are related to the electric parking brake device 20 of the second embodiment.
It is determined by the vehicle in which B is mounted, and is obtained in advance by experiments or the like. In the embodiment, the duty ratio D is calculated by superposing these relationships.

When the duty ratio D is calculated, the drive control of the electric motor 42 is performed so that the electric current is applied to the electric motor 42 at the calculated duty ratio D (step S304), and it is determined whether the driving of the electric motor 42 is finished (step S304). S30
6) Then, this routine is finished. It should be noted that the drive end determination of the electric motor 42 may be determined to end when a predetermined time has elapsed, or the rotation angle of the electric motor 42 or the hoisting gear 40 is equal to or greater than the rotation angle at which the parking brake is operated. Sometimes, it may be determined to end.

According to the electric parking brake device 20B of the second embodiment described above, the electric motor 42 is based on the vehicle speed V, the vehicle inclination angle θ, the vehicle weight W, and the temperature Tm of the electric motor 42.
The duty ratio D of the current applied to the
By controlling the driving of the parking brake, the braking force of the parking brake can be controlled. As a result, the parking brake unit 2
The braking force acting on the left and right rear wheels 12, 14 by 2, 24 can be made appropriate according to the state of the vehicle.

Electric parking brake system 20B of the second embodiment
Then, the duty ratio D of the current applied to the electric motor 42 is calculated based on the vehicle speed V, the vehicle inclination angle θ, the vehicle weight W, and the temperature Tm of the electric motor 42 to drive and control the electric motor 42. Inclination angle θ, vehicle weight W, electric motor 4
In addition to the temperature Tm of 2, the duty ratio D may be calculated based on other factors representing the state of the vehicle, or the vehicle speed V
And vehicle inclination angle θ, vehicle weight W, electric motor 42 temperature T
The duty ratio D may be calculated based on only a part of m.

Also, in the electric parking brake device 20B of the second embodiment, the braking force of the parking brake may be displayed on the indicator 78 as in the electric parking brake device 20 of the first embodiment.

Next, an electric parking brake device 20C as a third embodiment of the present invention will be described. The electric parking brake device 20C of the third embodiment has the same hardware configuration as the electric parking brake device 20 of the first embodiment except for the operation switch 70. Therefore, the description of the hardware configuration of the electric parking brake system 20C of the third embodiment will be omitted except for the description of the operation switch 70C provided in place of the operation switch 70. FIG. 14 shows an operation switch 7 included in the electric parking brake device 20C of the third embodiment.
It is an external view which illustrates the external appearance of 0C. The operation switch 70C of the electric parking brake device 20C of the third embodiment is provided at a position such as a front panel of the driver's seat where it is easy to operate, and as shown in the drawing, the lock side operation portion 71a and the release side operation portion 71b. With.

Next, the operation of the thus constructed electric parking brake system 20C of the third embodiment will be described. FIG. 15 is a flowchart showing an example of a parking brake operation control routine executed by the electronic control unit 50 of the electric parking brake device 20C of the third embodiment. This routine is executed when the operation switch 70C is operated.

When the parking brake operation control routine is executed along with the operation of the operation switch 70C by the occupant, the CPU 52 of the electronic control unit 50 first executes a process of reading the operation amount of the operation switch 70C by the occupant (step). S400). The operation amount of the operation switch 70C is read as the number of times the occupant operates the lock side operation unit 71a and the release side operation unit 71b.

Next, processing for reading the current target operating state of the parking brake is performed (step S402). FIG.
Shows an example of the relationship between the operating state and the braking force. As shown in the figure, in the electric parking brake device 20C of the third embodiment,
The operation state of the parking brake is set to nine stages including the state where the braking force is released, and the current target operation state is the RAM 56 when the target operation state is set.
Is stored at a predetermined address of. . Therefore, the current target operating state can be read in the RAM 56.
Is a process of accessing a predetermined address of and reading the contents.

Then, the target operation state is set based on the operation amount of the operation switch 70C and the current target operation state (step S404). The target operation state is set by setting the operation amount of the operation switch 70C to the lock side operation unit 7 for example.
When the target operation state is read as two operations of 1a and the current target operation state is the third step state, the target operation state is set as the fifth step state, and the operation amount of the operation switch 70C is set to the release side operation portion 71b. When the current target operating state is read as three operations and the current target operating state is the sixth stage state, the target operating state is set as the third stage state. When the operation amount of the operation switch 70C is large and the target operating state exceeds the 8th step or falls below the 0th step, the 8th step and the 0th step are set as the target operating state.

When the target operating state is set in this way, the electric motor 42 is drive-controlled so as to attain this target operating state (step S406), and the target operating state is stored in a predetermined address of the RAM 56 and is displayed on the indicator 78 and displayed. Exit the routine.

According to the electric parking brake device 20C of the third embodiment described above, the parking brake units 22, 2 are provided.
4, the braking force acting on the left and right rear wheels 12, 14 can be made to correspond to the operation amount of the operation switch 70C.

Electric parking brake system 20C of the third embodiment
In the above, the operation state of the parking brake is set to nine stages including the released state, but any number of stages may be used. Further, in the electric parking brake system 20C of the third embodiment, as shown in FIG. 16, the operating state is set to increase proportionally in steps, but it is not necessary to increase in proportion, and It just needs to grow larger.

Electric parking brake system 20C of the third embodiment
In the above, the number of operations of the lock side operation unit 71a and the release side operation unit 71b is used as the operation amount of the operation switch 70C.
The lock side operation part 71a and the release side operation part 71b of the operation switch 70C can be operated in two steps, and the parking brake is controlled based on the parking brake operation control routine illustrated in FIG. 15 for the first step operation. Shall operate and 2
The parking brake may be operated assuming that the operation state of the eighth step and the operation state of the zero step are set for the operation of the step. That is, when the second-step operation is performed on the lock-side operation portion 71a beyond the first-step operation, the eighth-step operation state is irrespective of the current operation status of the parking brake and the number of second-step operations. When the parking brake is actuated and the release-side operation unit 71b is operated in the second step beyond the operation in the first step, regardless of the current operating state of the parking brake and the number of operations in the second step, The parking brake is released as the operating state of the 0th stage. In this way, the parking brake can be fully activated and fully released with a single operation. It should be noted that, for the second-stage operation of the lock-side operation portion 71a, the fourth-stage operating state or the fifth-stage operating state may be set instead of the eighth-stage operating state. Further, the number of operations of the second stage of the operation switch 70C may be set to be twice or three times the number of operations of the first stage. That is, if the operation of the second stage of the lock side operation unit 71a is performed once, it is processed as if the operation of the first stage of the lock side operation unit 71a was performed twice or three times.

Electric parking brake device 20C of the third embodiment
Then, the target operation state is set based on the operation amount of the operation switch 70C and the current target operation state, and the electric motor 42 is drive-controlled to be in this target operation state. However, the operation amount of the operation switch 70C and the current operation state are set. The target operating state is set based on the state and the electric motor 4 is set so as to be in this target operating state.
2 may be drive-controlled.

Electric parking brake device 20C of the third embodiment
Although the operation switch 70C is configured as a push-type switch as illustrated in FIG. 14, the operation switch 70C is configured as a rotary switch as illustrated in the modification operation switch 70D in FIG. 17, or the modification in FIG. As an example of the operation switch 70E, it may be configured as a handle-type switch. Further, the operation amount of the operation switch is not limited to the number of times of operation, and may be the total time of operation on the lock side or the release side.

Although the embodiments of the present invention have been described with reference to the examples, the present invention is not limited to these examples, 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 parking brake operation start time processing routine executed by the electronic control unit 50 of the embodiment.

FIG. 4 is an explanatory diagram showing an example of a map of a relationship between a vehicle speed V and a target cable tension T *.

FIG. 5 is an explanatory diagram showing an example of a map of the relationship between the vehicle speed V and the target operating speed Vm * of the parking brake units 22, 24.

FIG. 6 is a flowchart showing an example of a parking brake operation state control routine executed by the electronic control unit 50.

FIG. 7 is an explanatory diagram showing an example of the adjustment of the cable tension T when the left and right rear wheels 12 and 14 are locked when the parking brake is operated in the vehicle traveling at the vehicle speed V.

FIG. 8 is an external view showing an example of an external appearance of a modified operation switch 70B.

FIG. 9 is a flowchart showing an example of a parking brake operation start time processing routine of a modified example executed by the electronic control unit 50.

FIG. 10 is an electric parking brake device 20B according to a second embodiment.
It is a block diagram which shows the outline of a structure of.

FIG. 11 is a flowchart showing an example of a parking brake operation start time processing routine executed by the electronic control unit 50 of the second embodiment.

FIG. 12 is an explanatory diagram showing an example of the relationship between the inclination angle θ or the weight W and the duty ratio D.

FIG. 13 is an explanatory diagram showing an example of the relationship between the temperature Tm of the electric motor 42 and the duty ratio D.

FIG. 14 is an electric parking brake device 20C of the third embodiment.
6 is an external view illustrating the external appearance of an operation switch 70C included in FIG.

FIG. 15 is an electric parking brake device 20C of the third embodiment.
6 is a flowchart showing an example of a parking brake operation control routine executed by the electronic control unit 50 of FIG.

FIG. 16 is an explanatory diagram showing an example of the relationship between the operating state of the parking brake and the braking force.

FIG. 17 is an external view illustrating the external appearance of a modified operation switch 70D.

FIG. 18 is an external view illustrating the external appearance of a modified operation switch 70E.

[Explanation of symbols]

12, 14 Rear wheels, 20, 20B, 20C Electric parking brake device, 22, 24 Parking brake unit, 26
Cable, 30 Cable winding unit, 32
Cable winding mechanism, 34 drive gear, 36 speed adjustment gear, 38 worm gear, 40 winding gear, 4
2 electric motor, 47, 48, 49 fixing member, 50 electronic control unit, 52 CPU, 54 ROM, 56 R
AM, 62, 64 wheel speed sensor, 66 tension sensor,
70, 70B to 70E operation switch, 71a lock side operation section, 71b release side operation section, 72 on / off switch, 74 volume switch, 78 indicator, 80 temperature sensor, 82 G sensor, 84 vehicle weight sensor.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Yamamoto 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Nobuto Higashi 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (56) References JP-A-59-145658 (JP, A) JP-A-59-140152 (JP, A) JP-A-7-144623 (JP, A) JP-A-63-101154 (JP, A) Kaihei 8-34325 (JP, A) Actually open 60-60354 (JP, U) Actually open 55-71962 (JP, U) Actually open 1-81163 (JP, U) (58) Fields investigated ( Int.Cl. ⁷ , DB name) B60T 7/12 B60T 8/32

Claims (7)

(57) [Claims] 1. An electric parking brake device for operating a parking brake by an electric drive means based on an operation of an operation member, the travel detecting means detecting a travel speed of a vehicle, and the travel of the vehicle is detected. When the operating member is operated, a relationship or a plurality of steps in which the braking force of the parking brake becomes smaller smoothly as the traveling speed of the vehicle becomes higher within a predetermined speed range. An electric parking brake device comprising: a control unit that drives and controls the electric drive unit that applies the braking force of the parking brake in a relationship that has a stepwise change. 2. The electric parking brake according to claim 1, wherein the control means is a means for controlling the electric drive means so that a rising gradient of a braking force of the parking brake becomes smaller as the detected traveling speed becomes higher. apparatus. 3. The electric parking brake device according to claim 1, wherein the operation member is a member capable of instructing a magnitude of a braking force of the parking brake, and the control unit is the parking brake. The electric parking brake device, which is a means for controlling the braking force of the vehicle so that the braking force thereof becomes the magnitude instructed by the operating member. 4. The electric parking brake device according to claim 1, wherein the electric drive unit is a unit including an electric motor, and the control unit controls the braking force of the parking brake by the electric motor. An electric parking brake device that is a means for performing the duty control of the. 5. The electric parking brake system according to claim 4, further comprising a state detection unit that detects a state of the vehicle, wherein the control unit controls the electric motor based on the state detected by the state detection unit. An electric parking brake device that is a means for performing duty control. 6. The electric parking brake system according to claim 1, wherein the operation member is a member capable of instructing release of a braking force of the parking brake, and the control unit is configured to perform the operation. An electric parking brake device, which is means for driving and controlling the electric drive means so that the braking force of the parking brake is released when the member gives an instruction to release the braking force of the parking brake. 7. The degree of braking force of the parking brake is displayed.
7. A display unit according to claim 1, further comprising:
Electric parking brake device.