JP2017200780A - Vehicular braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit a frictional braking member from becoming a fading state.SOLUTION: A vehicular braking device 11 includes: a frictional braking mechanism 37 for generating frictional braking force in a wheel of a vehicle 12; an accelerator pedal 21 operated when the vehicle 12 is accelerated/decelerated and having an acceleration range and a deceleration range in an operation range related to acceleration and deceleration; an acceleration/deceleration control section 73 for performing braking control of the vehicle 12 so that when a deceleration operation of the accelerator pedal 21 is performed, actual braking force applied to the vehicle 12 follows target braking force on the basis of target deceleration TG corresponding to the deceleration operation; and an input/output section 61 for acquiring a pad temperature value Tpd. When the pad temperature value Tpd exceeds a first temperature threshold value Tpdth1, the acceleration/deceleration control section 73 reduces the actual braking force applied to the vehicle 12 and performs the braking control of the vehicle 12 by using the reduced actual braking force.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle braking device that generates a driving force and an engine braking force using, for example, an internal combustion engine.

  For example, in a vehicle that uses an internal combustion engine to generate a driving force and a braking force, the internal combustion engine generates a driving force (driving torque) corresponding to the amount of operation of the accelerator pedal, and the fuel supply is shut off when the accelerator is off. As a result, engine braking force (generally referred to as “engine brake”) due to the linkage between the internal combustion engine and the power transmission mechanism (including the transmission), and friction braking force generated by the friction braking member including the brake pad and the disk rotor are generated. To reduce the vehicle speed.

  Patent Document 1 discloses an invention of a travel control device that executes one-pedal mode control for controlling both driving force and braking force of a vehicle according to an operation amount of one pedal in a vehicle equipped with an internal combustion engine. Has been. The travel control device according to Patent Document 1 is based on temperature measuring means for measuring the temperature of a friction braking member such as a brake pad or a disc rotor that generates a friction braking force, and the temperature of the friction braking member measured by the temperature measuring means. Target braking force correcting means for correcting the target braking force.

  According to the travel control device according to Patent Document 1, since the friction braking force can be appropriately generated by correcting the target braking force based on the temperature of the friction braking member, it is possible regardless of the temperature of the friction braking member. A stable friction braking force can be obtained.

JP 2001-071794 A (see, for example, claim 22)

  In the travel control device according to Patent Literature 1, if a friction brake (friction braking force) is frequently used, there is a concern that the friction braking member may overheat and fall into a fade state. Therefore, when the application of the friction braking force is assumed as the braking force based on the one-pedal mode control, when the target braking force is corrected based on the temperature of the friction braking member, the situation where the friction braking member falls into a fade state is suppressed. Special consideration is required. In this regard, the travel control device according to Patent Document 1 does not have a specific description on how to correct the target braking force based on the temperature of the friction braking member.

  The present invention has been made in view of the above circumstances, and when the application of the friction braking force is assumed as the actual braking force based on the deceleration operation of the acceleration / deceleration operation element, the situation in which the friction braking member falls into a fade state. An object of the present invention is to provide a vehicle braking device that can be suppressed.

  In order to achieve the above object, the invention according to (1) is operated at the time of accelerating and decelerating the friction braking unit that generates a friction braking force by causing a friction braking member to act on a vehicle wheel, A target deceleration is calculated based on an acceleration / deceleration operator having an acceleration region and a deceleration region set in the operation range related to the acceleration / deceleration, and a deceleration operation of the acceleration / deceleration operator, and braking based on the calculated target deceleration A brake control unit that performs control, and a temperature acquisition unit that acquires a temperature related to the friction brake member, and the brake control unit is configured to control the temperature when the temperature related to the friction brake member exceeds a predetermined temperature threshold. The main feature is to reduce the target deceleration as compared with a case where the value is equal to or less than a threshold value.

  The factor that causes the friction braking member to fade is the overheating of the friction braking member due to frequent use of the friction braking force. Therefore, when the temperature related to the friction braking member exceeds a predetermined temperature threshold (when the friction braking member is highly likely to fall into an overheated state), it is assumed that the friction braking member falls into a fade state. It is preferable to adopt.

Therefore, in the invention according to (1), the braking control unit adopts a configuration in which the target deceleration is decreased when the temperature related to the friction braking member exceeds a predetermined temperature threshold as compared with a case where the temperature is equal to or lower than the temperature threshold. It was decided.
When the target deceleration is decreased, the actual braking force is also decreased. However, even if the actual braking force based on the one-pedal mode control is reduced, the driver who senses that the braking force is insufficient performs a braking operation such as depressing the brake pedal, so the probability that the driver feels uncomfortable is low. . The frequent use of the friction braking force based on the braking operation is known as a factor that causes the friction braking member to fall into a fade state. Therefore, the driver will perform the braking operation while being careful so that the friction braking member does not fall into a fade state.

  Here, acquiring the temperature related to the friction braking member refers to acquiring the temperature value related to the friction braking member (for example, the brake pad and the disc rotor), as well as to the friction braking member such as the hydraulic pressure value that mediates the friction braking force. It is a concept that comprehensively includes obtaining a value that correlates to such temperature.

  According to the invention according to (1), the braking control unit reduces the target deceleration when the temperature related to the friction braking member exceeds a predetermined temperature threshold as compared with a case where the temperature is equal to or lower than the temperature threshold (as a result, Therefore, when the friction braking force is assumed to be applied as the actual braking force based on the deceleration operation of the acceleration / deceleration operation element, the situation in which the friction braking member falls into a fade state can be suppressed.

  Further, the invention according to (2) is the vehicle braking device according to (1), in which the total sum of the target deceleration in the deceleration region when the temperature related to the friction braking member exceeds the temperature threshold is: The temperature relating to the friction braking member is set to be smaller than that in the case where the temperature is equal to or lower than the temperature threshold value.

  According to the studies by the present inventors, the sum of the target deceleration (agreement with the friction braking force) in the deceleration region is effective as an index for determining whether or not the friction braking member falls into a fade state. know.

  Therefore, in the invention according to (2), the total target deceleration in the deceleration region when the temperature related to the friction braking member exceeds the temperature threshold is smaller than when the temperature related to the friction braking member is equal to or lower than the temperature threshold. The configuration set to the value was adopted.

  According to the invention according to (2), the sum of the target deceleration in the deceleration region when the temperature related to the friction braking member exceeds the temperature threshold is smaller than when the temperature related to the friction braking member is equal to or lower than the temperature threshold. When the probability that the friction braking member falls into the fade state is high, the situation in which the friction braking member falls into the fade state as a result of reducing the friction braking force generated at that time can be suppressed. .

  The invention according to (3) is the vehicle braking device according to (1) or (2), wherein the maximum value of the target deceleration decreases as the temperature of the friction braking member increases. It is characterized by being set to.

  According to the invention according to (3), the maximum value of the target deceleration is set to a characteristic that decreases as the temperature related to the friction braking member increases, and the probability that the friction braking member falls into a fade state increases. As a result of reducing the friction braking force generated at the time, the situation in which the friction braking member falls into a fade state can be suppressed.

  The invention according to (4) is the vehicle braking device according to (1) or (2), wherein the maximum value of the target deceleration is irrespective of the temperature level of the friction braking member, The characteristic is set to be a common characteristic, and the target deceleration is set to a characteristic in which an increase amount with respect to a change in the degree of the deceleration operation is non-linear.

In the invention according to (4), the maximum value of the target deceleration is set to a common characteristic regardless of the temperature of the friction braking member. Therefore, according to the invention according to (4), the maximum value of the friction braking force generated at that time is set in common regardless of the probability that the friction braking member falls into a fade state. A relatively large actual braking force can be generated as necessary while suppressing the situation of falling into a state.
Further, according to the invention according to (4), the target deceleration is a characteristic in which the increase amount (target deceleration) with respect to the change in the degree of the deceleration operation is nonlinear, specifically, the degree of the deceleration operation is increased. Accordingly, since the increase in the target deceleration is set to a characteristic that increases, the increase in the target deceleration is suppressed, and as a result, the situation in which the friction braking member falls into a fade state can be suppressed.

  Moreover, the invention which concerns on (5) is a vehicle braking device as described in any one of (1)-(4), Comprising: The said braking control part WHEREIN: The temperature which concerns on the said friction braking member makes the said temperature threshold value. If the acceleration / deceleration operator is being operated when updating the target deceleration after correction, which has been reduced compared to the case where the temperature is below the temperature threshold, as the target deceleration, The target deceleration is decreased so as to follow the corrected target deceleration more slowly than in a case where the target deceleration is not performed.

  When the temperature related to the friction braking member exceeds the temperature threshold, the acceleration / deceleration operator is operated to update and set the corrected target deceleration, which is reduced compared to the case where the temperature is equal to or lower than the temperature threshold, as the target deceleration. If the target deceleration is sharply reduced, the driver feels uncomfortable. In addition, when a configuration is adopted in which the target deceleration follows (decreases) the target deceleration after correction at the timing when the acceleration / deceleration operator is not operated, for example, in the case of traveling on a long downhill, the acceleration / deceleration operator It is also assumed that the target deceleration cannot be corrected by continuing to operate the.

  Therefore, in the invention according to (5), the braking control unit reduces the target deceleration after correction, which is reduced compared to the case where the temperature related to the friction braking member exceeds the temperature threshold, compared to the case where the temperature is equal to or lower than the temperature threshold. When updating the speed, if the acceleration / deceleration operator is operated, decrease the target deceleration so that the target deceleration follows the corrected target deceleration more slowly than when it is not operated. The configuration was adopted.

  According to the invention according to (5), for example, even when the vehicle travels on a long downhill, the acceleration / deceleration operator is continuously operated without causing the driver to feel uncomfortable, thereby reducing the target deceleration. It is possible to prevent the situation where the friction braking member falls into a fade state.

  According to the vehicle brake device of the present invention, when the application of the friction braking force is assumed as the actual braking force based on the deceleration operation of the acceleration / deceleration operation element, the situation in which the friction braking member falls into the fade state is suppressed. Can do.

It is a block block diagram showing the outline | summary of the vehicle braking device which concerns on embodiment of this invention. It is a flowchart figure showing operation | movement of the vehicle braking device which concerns on 1st Embodiment. It is a figure where it uses for operation | movement description of the vehicle braking device which concerns on 1st Embodiment. It is a flowchart figure showing operation | movement of the vehicle braking device which concerns on 2nd Embodiment. It is a figure where it uses for operation | movement description of the braking device for vehicles which concerns on 2nd Embodiment. It is a figure where it uses for operation | movement description of the braking device for vehicles which concerns on 2nd Embodiment.

Hereinafter, a vehicle braking device according to an embodiment of the present invention will be described in detail with reference to the drawings.
Note that, in the drawings shown below, in principle, common reference numerals are assigned between members having a common function or between members having functions corresponding to each other. Further, for convenience of explanation, the size and shape of the member may be schematically represented by being deformed or exaggerated.

[Vehicle Braking Device 11 According to an Embodiment of the Present Invention]
A vehicle braking device 11 according to an embodiment of the present invention will be described with reference to FIG. 1 exemplifying a vehicle 12 on which an internal combustion engine 41 is mounted. FIG. 1 is a block diagram showing an outline of a vehicle braking device 11 according to an embodiment of the present invention.
The block diagram related to the vehicle braking device 11 shown in FIG. 1 is common between the first and second embodiments of the present invention. However, the functions of some of the functional units related to the vehicle braking device 11 are different from each other. Therefore, hereinafter, the vehicle braking device 11 according to the first embodiment will be described unless otherwise specified. Moreover, when describing the function part peculiar to the vehicle braking device 11 which concerns on 2nd Embodiment, it shall refuse that.

As shown in FIG. 1, a vehicle braking apparatus 11 according to an embodiment of the present invention includes a CAN (Control Area) between an acceleration / deceleration ECU (Electronic Control Unit) 13, an ABS-ECU 15, a VSA-ECU 16, and a meter ECU 17. Network) or the like via a communication medium 19 such that data can be exchanged with each other.
Each of the acceleration / deceleration ECU 13, the ABS-ECU 15, the VSA-ECU 16, and the meter ECU 17 is configured by a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The microcomputer reads and executes programs and data stored in the ROM, and operates to control execution of various functions of the acceleration / deceleration ECU 13, ABS-ECU 15, VSA-ECU 16, and meter ECU 17. .

  The acceleration / deceleration ECU (Electronic Control Unit) 13 has a function of performing acceleration / deceleration control of the vehicle 12. The internal configuration of the acceleration / deceleration ECU 13 will be described later in detail. The ABS-ECU 15 has a function of preventing the wheels (not shown) from being locked during the braking operation of the vehicle 12. The VSA (“VSA” is a registered trademark) -ECU 16 has a function of supporting behavior stabilization related to the vehicle 12. The meter ECU 17 includes a display unit 18 for displaying various information including the vehicle speed, the number of engine times, the coolant temperature, fade warning information of the friction braking member 45 (details will be described later), and the like. It has a function to perform.

As shown in FIG. 1, the communication medium 19 includes an accelerator pedal sensor 23 for detecting a stepping operation amount from an initial position of the accelerator pedal 21 (a state in which the operation by the driver is released), and a stepping operation amount of the brake pedal 25. A brake pedal sensor 27 for detecting the vehicle speed, a vehicle speed sensor 29 for detecting the speed (vehicle speed) of the vehicle 12, a front / rear G sensor 31 for detecting the longitudinal acceleration / deceleration generated in the vehicle 12, an AP operation mode changeover switch 33, and a driving brake A mechanism 35 and a friction braking mechanism 37 are connected.
Various data detected by the accelerator pedal sensor 23, the brake pedal sensor 27, the vehicle speed sensor 29, the front / rear G sensor 31, and the mode switching data related to the AP operation mode switching switch 33 are transmitted via the communication medium 19 to the acceleration / deceleration ECU 13, ABS -Sent to ECU 15, VSA-ECU 16, and meter ECU 17.
The accelerator pedal 21 operated when the vehicle 12 is accelerated / decelerated corresponds to the “acceleration / deceleration operator” of the present invention.

The AP operation mode switching switch 33 is a switch operated when switching the operation mode of the accelerator pedal 21 (hereinafter referred to as “AP operation mode”). The AP operation mode changeover switch 33 is provided on an instrument panel (not shown) in the vehicle cabin. As the AP operation mode, a normal mode in which only acceleration control corresponding to the depression operation amount of the accelerator pedal 21 is performed, and a one-pedal mode in which acceleration / deceleration control is performed according to the depression / retraction operation amount of the accelerator pedal 21 are set. ing. Details of the one-pedal mode will be described later.
The AP operation mode changeover switch 33 may adopt a configuration that omits the driver's operation by setting the one-pedal mode by default.

  As shown in FIG. 1, the driving / braking mechanism 35 includes an internal combustion engine 41 that is a drive source of the vehicle 12 and a continuously variable transmission (CVT) 43. However, the continuously variable transmission 43 may be a normal (stepped) transmission. The driving / braking mechanism 35 has a function of driving the vehicle 12 based on a control command of the acceleration / deceleration ECU 13 and generating an engine braking force as necessary.

  The friction braking mechanism 37 includes components related to friction braking, such as a friction braking member 45 including a brake pad and a disk rotor, and a hydraulic system 47. The friction braking mechanism 37 has a function of generating a friction braking force on the wheels of the vehicle 12 based on a control command of the acceleration / deceleration ECU 13. The friction braking member 45 is provided with a pad temperature sensor 49 for detecting the temperature of the brake pad. The pad temperature value data Tpd detected by the pad temperature sensor 49 is sent to the acceleration / deceleration ECU 13 via the communication medium 19. The friction braking mechanism 37 corresponds to the “friction braking portion” of the present invention.

[Internal configuration of acceleration / deceleration ECU 13]
Next, the internal configuration of the acceleration / deceleration ECU 13 will be described with reference to FIG.
As shown in FIG. 1, the acceleration / deceleration ECU 13 includes an input / output unit 61, a calculation unit 63, and a storage unit 65.

  The input / output unit 61 includes, as input data, acceleration / deceleration operation amount data (AP acceleration / deceleration operation amount data) related to the accelerator pedal sensor 23, braking operation amount data (BP braking operation amount data) related to the brake pedal sensor 27, and vehicle speed sensor. 29, vehicle speed data according to 29, front / rear G data relating to the front / rear G sensor 31, pad temperature value data Tpd relating to the pad temperature sensor 49, mode switching data relating to the AP operation mode changeover switch 33, and the like are input. It has a function of outputting driving braking control data related to the engine 41, friction braking control data related to the friction braking member 45, and the like. The input / output unit 61 corresponds to a “temperature acquisition unit” of the present invention.

  The calculation unit 63 is based on the AP acceleration / deceleration operation amount data, BP braking operation amount data, vehicle speed data, front / rear G data, pad temperature value data Tpd, mode switching data, etc. It has a function of calculating friction braking control data and the like related to the friction braking member 45. More specifically, the calculation unit 63 includes a target acceleration / deceleration setting unit 71 and an acceleration / deceleration control unit 73.

  The target acceleration / deceleration setting unit 71 is based on input data such as AP acceleration / deceleration operation amount data, BP braking operation amount data, pad temperature value data Tpd related to the pad temperature sensor 49, and so on. It may be referred to as “target acceleration / deceleration”).

  Specifically, in the normal mode, the target acceleration / deceleration setting unit 71 sets the target acceleration based on the BP braking operation amount data, and sets the target acceleration based on the AP acceleration / deceleration operation amount data. That is, in the normal mode, only the acceleration of the vehicle 12 is controlled according to the AP acceleration / deceleration operation amount data. As a result, the entire depression / step-back operation range of the accelerator pedal 21 (the range in which the AP acceleration / deceleration operation amount data can be obtained) is used in principle for accelerating the vehicle 12. However, in the normal mode, the engine braking force generated when the accelerator pedal 21 is stepped back to the vicinity of the initial position acts normally.

  In contrast, in the one-pedal mode, the target acceleration / deceleration setting unit 71 is similar to the normal mode in that the target deceleration TG is set based on the BP braking operation amount data. The point that the target acceleration and the target deceleration TG are set based on the temperature value data Tpd is different from the case in the normal mode. The mode in which the target deceleration TG is set based on the AP acceleration / deceleration operation amount data and the pad temperature value data Tpd in the one pedal mode will be described later in detail.

  In order to set both acceleration and deceleration by operating a single pedal (accelerator pedal 21), the relationship of the target acceleration / deceleration corresponding to the depression operation amount (AP acceleration / deceleration operation amount data) related to the accelerator pedal 21 is determined by driving. The target deceleration TG that is maximum at the initial position in the state where the accelerator pedal 21 is released by the user is associated, while in the deceleration region starting from the initial position, in principle, the target deceleration (even if the degree of depression increases) There is a part where the speed TG maintains a constant value.) The target deceleration TG is set to decrease as the degree of depression increases. As a result, in the one-pedal mode, both acceleration and deceleration of the vehicle 12 are controlled according to the AP acceleration / deceleration operation amount data.

  Of the target deceleration TG corresponding to the operation range (the range in which the AP acceleration / deceleration operation amount data can be obtained) related to the depression / retraction of the accelerator pedal 21, for example, as shown in FIG. 3, it corresponds to the initial position of the accelerator pedal 21. An area for deceleration starting from an initial value (target deceleration TG = maximum deceleration) P0 as a starting point and having a boundary threshold value P1 as an end point is referred to as a “deceleration area”. An area for acceleration in which the accelerator pedal 21 is depressed by exceeding the boundary threshold value P1 is referred to as an “acceleration area”. Note that the range of the deceleration region and the acceleration region (the size of the boundary threshold value P1) is variable according to the increase or decrease of the vehicle speed.

The acceleration / deceleration control unit 73 has a function of performing acceleration / deceleration control of the vehicle 12 based on input data such as vehicle speed data, front / rear G data, and the target acceleration / deceleration set by the target acceleration / deceleration setting unit 71. In order to realize such acceleration / deceleration control, the acceleration / deceleration control unit 73 includes an engine control unit 75 and a brake control unit 77.
The target acceleration / deceleration setting unit 71 and the acceleration / deceleration control unit 73 correspond to the “braking control unit” of the present invention.

  Based on the target acceleration / deceleration set by the target acceleration / deceleration setting unit 71, the engine control unit 75 controls the driving / braking mechanism 35 that exhibits the driving force and the engine braking force related to the internal combustion engine 41. The brake control unit 77 controls the friction braking mechanism 37 that exhibits the friction braking force based on the target deceleration TG set by the target acceleration / deceleration setting unit 71.

  The storage unit 65 includes a nonvolatile memory and a volatile memory (not shown). The nonvolatile memory is, for example, a flash memory or an EEPROM (Electrically Erasable Programmable Read Only Memory), and stores a program for executing various processes in the arithmetic unit 63. The volatile memory is, for example, a DRAM (Dynamic Random Access Memory), and input / output data and calculation results are temporarily stored when various processes in the calculation unit 63 are executed.

  The storage unit 65 also includes reference characteristic information GSC 0, first characteristic information regarding multiple types of AP-deceleration characteristic information set by the target acceleration / deceleration setting unit 71 based on the AP acceleration / deceleration operation amount data and the pad temperature value data Tpd. Characteristic information GSC1, second characteristic information GSC2, and third characteristic information GSC3 (see FIG. 3) are stored. Further, the storage unit 65 stores the first temperature as a temperature threshold value for demarcating the temperature region to which the pad temperature value Tpd belongs, which is referred to when determining the alertness level regarding the situation in which the friction braking member 45 falls into the fade state. A threshold value Tpdth1, a second temperature threshold value Tpdth2, and a third temperature threshold value Tpdth3 (where Tpdth1 <Tpdth2 <Tpdth3) are stored.

  As a plurality of types of AP-deceleration characteristic information, predetermined characteristic information is associated with the temperature range to which the pad temperature value Tpd belongs. Specifically, as shown in FIG. 3, the reference characteristic information GSC0 is the pad temperature value Tpd <= first temperature threshold value Tpdth1, and the first temperature threshold value Tpdth1 <pad temperature value Tpd <= the first temperature threshold value Tpdth2. The characteristic information GSC1 corresponds to the second temperature threshold value Tpdth2 <pad temperature value Tpd <= the third temperature threshold value Tpdth3, and the second characteristic information GSC2 corresponds to the pad temperature value Tpd> the third temperature threshold value Tpdth3, respectively. Used selectively.

[Operation of Vehicle Braking Device 11 According to First Embodiment]
Next, the operation of the vehicle braking device 11 according to the first embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a flowchart showing the operation of the vehicle braking device 11 according to the first embodiment. FIG. 3 is a diagram for explaining the operation of the vehicle braking device according to the first embodiment.
However, it is assumed that the AP operation mode is set to the one pedal mode.

  In step S <b> 11 shown in FIG. 2, the acceleration / deceleration ECU 13 inputs various data including the AP acceleration / deceleration operation amount data and the pad temperature value data Tpd via the communication medium 19.

  In step S12, the calculation unit 63 of the acceleration / deceleration ECU 13 determines whether or not the pad temperature value Tpd exceeds the third temperature threshold value Tpdth3 (Tpd> Tpdth3?). As the third temperature threshold value Tpdth3, as shown in FIG. 3, a pad temperature value Tpd corresponding to the highest level may be appropriately adopted as a fade warning level related to a situation in which the friction braking member 45 falls into a fade state.

As a result of the determination in step S12, when it is determined that the pad temperature value Tpd is equal to or lower than the third temperature threshold value Tpdth3 (“No” in step S12), the acceleration / deceleration ECU 13 proceeds to the next step S13. Proceed to.
On the other hand, as a result of the determination in step S12, when it is determined that the pad temperature value Tpd exceeds the third temperature threshold value Tpdth3 (“Yes” in step S12), the acceleration / deceleration ECU 13 steps the process flow. Jump to S18.

  In step S13, the calculation unit 63 of the acceleration / deceleration ECU 13 determines whether or not the pad temperature value Tpd exceeds the second temperature threshold value Tpdth2 (Tpd> Tpdth2?). As the second temperature threshold value Tpdth2, as shown in FIG. 3, a pad temperature value Tpd corresponding to a medium level may be appropriately adopted as a fade alertness level.

As a result of the determination in step S13, when it is determined that the pad temperature value Tpd is equal to or lower than the second temperature threshold value Tpdth2 (“No” in step S13), the acceleration / deceleration ECU 13 proceeds to the next step S14. Proceed to.
On the other hand, if it is determined in step S13 that the pad temperature value Tpd exceeds the second temperature threshold value Tpdth2 (“Yes” in step S13), the acceleration / deceleration ECU 13 steps the process flow. Jump to S17.

  In step S14, the calculation unit 63 of the acceleration / deceleration ECU 13 determines whether or not the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1 (Tpd> Tpdth1?). As the first temperature threshold value Tpdth1, as shown in FIG. 3, a pad temperature value Tpd corresponding to a small level may be appropriately employed as the fade alertness level.

As a result of the determination in step S14, if it is determined that the pad temperature value Tpd is equal to or less than the first temperature threshold value Tpdth1 (fade vigilance: corresponding to the lowest level) (“No” in step S14), the acceleration / deceleration ECU 13 Advances the process flow to the next step S15.
On the other hand, as a result of the determination in step S14, if it is determined that the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1 (“Yes” in step S14), the acceleration / deceleration ECU 13 steps the process flow. Jump to S16.

  In step S15, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines the AP-deceleration characteristic information based on the determination result that the pad temperature value Tpd is equal to or less than the first temperature threshold value Tpdth1 (fade warning level: lowest level). Is selected as the reference characteristic information GSC0, and using the selected reference characteristic information GSC0, the braking control similar to the normal process is executed. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

  In step S16, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines that AP-decrease based on the determination result that the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1 (fade warning level: small level). The first characteristic information GSC1 is selected as the speed characteristic information, and the braking control is executed using the selected first characteristic information GSC1 in a state where the maximum deceleration is reduced as compared with the normal processing in step S15. Further, the meter ECU 17 prompts the driver to warn against the fade by causing the display unit 18 to display that the fade warning level is “low level”. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

  In step S17, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines that AP-decrease based on the determination result that the pad temperature value Tpd exceeds the second temperature threshold value Tpdth2 (fade warning level: medium level). The second characteristic information GSC2 is selected as the speed characteristic information, and the braking control is executed using the selected second characteristic information GSC2 in a state where the maximum deceleration is further reduced as compared with the process of step S16. Further, the meter ECU 17 prompts the driver to warn against the fade by causing the display unit 18 to display that the fade warning level is “medium level”. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

  In step S18, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines that AP-decrease based on the determination result that the pad temperature value Tpd exceeds the third temperature threshold value Tpdth3 (fade warning level: highest level). The third characteristic information GSC3 is selected as the speed characteristic information, and the braking control is executed using the selected third characteristic information GSC3 in a state where the maximum deceleration is further reduced as compared with the process of step S17. In addition, the meter ECU 17 displays a warning that the fade warning level is “highest level” on the display unit 18, thereby issuing a warning about the fade to the driver. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

[Configuration of Vehicle Braking Device 11 According to Second Embodiment]
The storage unit 65 of the vehicle brake device 11 according to the second embodiment stores a plurality of types of AP-deceleration characteristics set by the target acceleration / deceleration setting unit 71 based on the AP acceleration / deceleration operation amount data and the pad temperature value data Tpd. Regarding the information, reference characteristic information GSC0, fourth characteristic information GSC4, fifth characteristic information GSC5, and sixth characteristic information GSC6 (see FIGS. 5A and 5B) are stored. Further, the storage unit 65 stores the fourth temperature as a temperature threshold value for demarcating the temperature region to which the pad temperature value Tpd belongs, which is referred to when determining the alertness level regarding the situation in which the friction braking member 45 falls into the fade state. A threshold value Tpdth4, a fifth temperature threshold value Tpdth5, and a sixth temperature threshold value Tpdth6 (where Tpdth4 <Tpdth5 <Tpdth6) are stored.

  As a plurality of types of AP-deceleration characteristic information, predetermined characteristic information is associated with the temperature range to which the pad temperature value Tpd belongs. Specifically, as shown in FIGS. 5A and 5B, the reference temperature information GSC0 indicates that the pad temperature value Tpd <= the fourth temperature threshold value Tpdth4, the fourth temperature threshold value Tpdth4 <the pad temperature value Tpd <= the fifth temperature threshold value Tpdth5. In the fourth characteristic information GSC4, the fifth temperature threshold value Tpdth5 <the pad temperature value Tpd <= the sixth temperature threshold value Tpdth6, the fifth characteristic information GSC5, and the pad temperature value Tpd> the sixth temperature threshold value Tpdth6, the sixth characteristic information GSC6 Are selectively used in association with each other.

[Operation of Vehicle Braking Device 11 According to Second Embodiment]
Next, the operation of the vehicle brake device 11 according to the second embodiment will be described with reference to FIGS. 4, 5A, and 5B. FIG. 4 is a flowchart showing the operation of the vehicle braking device 11 according to the second embodiment. 5A and 5B are diagrams for explaining the operation of the vehicle braking device 11 according to the second embodiment.
However, it is assumed that the AP operation mode is set to the one pedal mode.

  In step S21 shown in FIG. 4, the acceleration / deceleration ECU 13 inputs various data including AP acceleration / deceleration operation amount data and pad temperature value data Tpd via the communication medium 19.

  In step S22, the calculation unit 63 of the acceleration / deceleration ECU 13 determines whether or not the pad temperature value Tpd exceeds the sixth temperature threshold value Tpdth6 (Tpd> Tpdth6?). As the sixth temperature threshold value Tpdth6, as shown in FIG. 5B, a pad temperature value Tpd corresponding to the highest level may be appropriately adopted as a fade warning degree related to a situation in which the friction braking member 45 falls into a fade state.

As a result of the determination in step S22, when it is determined that the pad temperature value Tpd is equal to or less than the sixth temperature threshold value Tpdth6 (“No” in step S22), the acceleration / deceleration ECU 13 proceeds to the next step S23. Proceed to.
On the other hand, as a result of the determination in step S22, if it is determined that the pad temperature value Tpd exceeds the sixth temperature threshold value Tpdth6 (“Yes” in step S22), the acceleration / deceleration ECU 13 steps the process flow. Jump to S28.

  In step S23, the calculation unit 63 of the acceleration / deceleration ECU 13 determines whether or not the pad temperature value Tpd exceeds the fifth temperature threshold value Tpdth5 (Tpd> Tpdth5?). As the fifth temperature threshold value Tpdth5, as shown in FIG. 5B, a pad temperature value Tpd corresponding to a medium level may be appropriately adopted as the fade alertness level.

As a result of the determination in step S23, when it is determined that the pad temperature value Tpd is equal to or lower than the fifth temperature threshold value Tpdth5 (“No” in step S23), the acceleration / deceleration ECU 13 proceeds to the next step S24. Proceed to.
On the other hand, as a result of the determination in step S23, if it is determined that the pad temperature value Tpd exceeds the fifth temperature threshold value Tpdth5 (“Yes” in step S23), the acceleration / deceleration ECU 13 steps the process flow. Jump to S27.

  In step S24, the calculation unit 63 of the acceleration / deceleration ECU 13 determines whether or not the pad temperature value Tpd exceeds the fourth temperature threshold value Tpdth4 (Tpd> Tpdth4?). As the fourth temperature threshold value Tpdth4, as shown in FIG. 5B, a pad temperature value Tpd corresponding to a small level may be appropriately employed as the fade alertness level.

As a result of the determination in step S24, if it is determined that the pad temperature value Tpd is equal to or lower than the fourth temperature threshold value Tpdth4 (fade alert level: corresponding to the lowest level) (“No” in step S24), the acceleration / deceleration ECU 13 Advances the process flow to the next step S25.
On the other hand, as a result of the determination in step S24, when it is determined that the pad temperature value Tpd exceeds the fourth temperature threshold value Tpdth4 (“Yes” in step S24), the acceleration / deceleration ECU 13 steps the process flow. Jump to S26.

  In step S25, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines the AP-deceleration characteristic information based on the determination result that the pad temperature value Tpd is equal to or lower than the fourth temperature threshold value Tpdth4 (fading warning level: minimum level). Is selected as the reference characteristic information GSC0, and using the selected reference characteristic information GSC0, the braking control similar to the normal process is executed. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

  In step S26, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines that AP-decrease based on the determination result that the pad temperature value Tpd exceeds the fourth temperature threshold value Tpdth4 (fade warning level: small level). The fourth characteristic information GSC4 is selected as the speed characteristic information, and the braking control is executed using the selected fourth characteristic information GSC4 in a state where the maximum deceleration is reduced as compared with the normal process in step S25. Further, the meter ECU 17 prompts the driver to warn against the fade by causing the display unit 18 to display that the fade warning level is “low level”. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

  In step S27, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines that AP-decrease based on the determination result that the pad temperature value Tpd exceeds the fifth temperature threshold value Tpdth5 (fade warning level: medium level). The fifth characteristic information GSC5 is selected as the speed characteristic information, and the braking control is executed using the selected fifth characteristic information GSC5 in a state where the maximum deceleration is further reduced as compared with the process of step S26. Further, the meter ECU 17 prompts the driver to warn against the fade by causing the display unit 18 to display that the fade warning level is “medium level”. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

  In step S28, the acceleration / deceleration control unit 73 of the acceleration / deceleration ECU 13 determines that AP-decrease based on the determination result that the pad temperature value Tpd exceeds the sixth temperature threshold value Tpdth6 (fading warning level: highest level). The sixth characteristic information GSC6 is selected as the speed characteristic information, and the braking control is executed using the selected sixth characteristic information GSC6 in a state where the maximum deceleration is further reduced as compared with the process of step S27. In addition, the meter ECU 17 displays a warning that the fade warning level is “highest level” on the display unit 18, thereby issuing a warning about the fade to the driver. Thereafter, the acceleration / deceleration ECU 13 ends the flow of a series of processes.

[Effects of the vehicle braking device 11 according to the embodiment of the present invention]
Next, the effect of the vehicle braking device 11 according to the embodiment of the present invention will be described.
The vehicle braking device 11 based on the first aspect accelerates and decelerates the vehicle 12 and a friction braking portion (friction braking mechanism) 37 that generates a friction braking force by applying a friction braking member 45 to the wheels of the vehicle 12. An accelerator pedal (acceleration / deceleration operator) 21 in which an acceleration region and a deceleration region are set with a boundary threshold value P1 in the operation range related to the acceleration / deceleration, and a deceleration operation (AP acceleration / deceleration operation) of the accelerator pedal 21 Acceleration / deceleration control unit (braking control unit) 73 that calculates a target deceleration TG based on the calculated amount of target deceleration TG and performs braking control based on the calculated target deceleration TG, and a pad temperature value (temperature related to the friction braking member 45). An input / output unit (temperature acquisition unit) 61 that acquires Tpd, and the acceleration / deceleration control unit 73 has a pad temperature value Tpd exceeding a first temperature threshold value Tpdth1 (fourth temperature threshold value Tpdth4) (predetermined temperature threshold value). If the pad temperature value Tpd is was decided in comparison with the case where the first temperature threshold value Tpdth1 is (fourth temperature threshold value Tpdth4) below employing the configuration to reduce the target deceleration TG.

  When the target deceleration TG is decreased, the actual braking force is also decreased. However, even if the actual braking force based on the one-pedal mode control is reduced, the driver who senses that the braking force is insufficient performs a braking operation such as depressing the brake pedal 25. Low. The frequent use of the friction braking force based on the braking operation is known as a factor that causes the friction braking member 45 to fall into a fade state. Therefore, the driver will perform a braking operation while being careful so that the friction braking member 45 does not fall into a fade state.

  According to the vehicle brake device 11 based on the first aspect, the acceleration / deceleration control unit 73 determines that the pad temperature value Tpd is the first when the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1 (fourth temperature threshold value Tpdth4). When the application of the friction braking force is assumed as the actual braking force based on the deceleration operation of the accelerator pedal 21, in order to reduce the target deceleration TG compared to the case where the temperature threshold value is Tpdth1 (fourth temperature threshold value Tpdth4) or less. A situation in which the friction braking member 45 falls into a fade state can be suppressed.

  The vehicle braking device 11 based on the second aspect is the vehicle braking device 11 based on the first aspect, and deceleration when the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1 (fourth temperature threshold value Tpdth4). The total sum of the target deceleration TG in the region may be set to a value smaller than that in the case where the pad temperature value Tpd is equal to or lower than the first temperature threshold value Tpdth1 (fourth temperature threshold value Tpdth4).

  According to the studies by the present inventors, the sum of the target deceleration (agreement with the friction braking force) in the deceleration region is effective as an index for determining whether or not the friction braking member 45 falls into a fade state. I know.

  According to the vehicle braking device 11 based on the second aspect, the sum of the target deceleration TG in the deceleration region when the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1 (fourth temperature threshold value Tpdth4) is the pad temperature value. When Tpd is set to a smaller value than when the first temperature threshold value Tpdth1 (fourth temperature threshold value Tpdth4) is equal to or less than the first temperature threshold value Tpdth1, and the probability that the friction braking member 45 falls into a fade state is high, the friction generated at that time As a result of the braking force being reduced, it is possible to suppress a situation in which the friction braking member 45 falls into a fade state.

  The vehicle braking device 11 based on the third aspect is the vehicle braking device 11 based on the first or second aspect, and the maximum value of the target deceleration TG in the deceleration region increases as the pad temperature value Tpd increases. You may employ | adopt the structure set to the characteristic which becomes small.

  According to the vehicle braking device 11 based on the third aspect, the maximum value of the target deceleration TG in the deceleration region is set to a characteristic that decreases as the pad temperature value Tpd increases, and the friction braking member 45 is in a faded state. As the probability of falling into the higher level, the friction braking force generated at that time becomes smaller, and as a result, the situation in which the friction braking member 45 falls into a fade state can be suppressed.

  The vehicle braking device 11 based on the fourth aspect is the vehicle braking device 11 based on the first or second aspect, and the maximum value of the target deceleration TG in the deceleration region is the level of the pad temperature value Tpd. Regardless of which the characteristic is set to be common, the target deceleration TG may be configured such that the increase amount with respect to the change in the degree of the deceleration operation is set to a non-linear characteristic.

In the vehicle braking device 11 based on the fourth aspect, the maximum value of the target deceleration TG is set to a common characteristic regardless of the pad temperature value Tpd. Therefore, according to the vehicle braking device 11 based on the fourth aspect, the maximum value of the friction braking force generated at that time is set in common regardless of the probability of the friction braking member falling into a fade state. A relatively large actual braking force can be generated as necessary while suppressing the situation where the friction braking member falls into a fade state.
Further, according to the vehicle braking device 11 based on the fourth aspect, the target deceleration TG has a characteristic that the increase amount (of the target deceleration TG) with respect to the change in the degree of the deceleration operation is nonlinear, specifically, Since the increase in the target deceleration TG increases as the degree of the deceleration operation increases, the friction braking member 45 falls into a fade state as a result of suppressing the increase in the target deceleration TG. Can be suppressed.

  The vehicle braking device 11 based on the fifth aspect is the vehicle braking device 11 based on any one of the first to fourth aspects, and the pad temperature value Tpd is the first temperature threshold value Tpdth1 (second embodiment). In the case of exceeding the fourth temperature threshold value Tpdth4; the same shall apply hereinafter), the accelerator is used to update and set the corrected target deceleration TG, which is reduced as compared with the case where it is equal to or less than the first temperature threshold Tpdth1, as the target deceleration TG. When the pedal 21 is operated, a configuration may be adopted in which the target deceleration TG is decreased so as to follow the corrected target deceleration TG more slowly than when the pedal 21 is not operated. .

  In the case where the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1, the accelerator pedal is used to update and set the corrected target deceleration TG that is reduced as compared with the case where the pad temperature value Tpdth1 is equal to or less than the first temperature threshold value Tpdth1. When 21 is operated, if the target deceleration TG is sharply reduced, the driver feels uncomfortable. Further, when a configuration is adopted in which the target deceleration TG follows (decreases) the corrected target deceleration TG at a timing when the accelerator pedal 21 is not operated, for example, in the case of traveling on a long downhill, the accelerator pedal 21 is used. It is also assumed that the target deceleration TG cannot be corrected for correction by continuing to be operated.

  Therefore, in the vehicle braking device 11 based on the fifth aspect, the acceleration / deceleration control unit 73 decreases when the pad temperature value Tpd exceeds the first temperature threshold value Tpdth1 as compared with the case where the pad temperature value Tpdth1 is equal to or less than the first temperature threshold value Tpdth1. When the corrected target deceleration TG is updated and set as the target deceleration TG, when the accelerator pedal 21 is operated, the target deceleration TG is slower in time than when the accelerator pedal 21 is not operated. A configuration is adopted in which the target deceleration TG after correction is reduced so as to follow.

  According to the vehicle braking device 11 based on the fifth aspect, for example, even in a case of traveling on a long downhill, the target pedal can be reduced by continuously operating the accelerator pedal 21 without causing the driver to feel uncomfortable. The situation where the speed TG cannot be reduced can be avoided and the situation where the friction braking member 45 falls into a fade state can be suppressed.

[Other Embodiments]
The plurality of embodiments described above show examples of realization of the present invention. Therefore, the technical scope of the present invention should not be limitedly interpreted by these. This is because the present invention can be implemented in various forms without departing from the gist or main features thereof.

  For example, in the first and second embodiments of the present invention, the AP-deceleration characteristic information that is the relationship information of the target deceleration TG associated with the change in the AP acceleration / deceleration operation amount has mainly linear characteristics. Although described above, the present invention is not limited to this example. As AP-deceleration characteristic information, an aspect having a non-linear characteristic based on an experiment or simulation may be appropriately adopted.

  Finally, in the embodiment according to the present invention, the example in which the braking device 11 for an electric vehicle according to the present invention is applied to the vehicle 12 equipped with the internal combustion engine 41 as a power source has been described. Is not limited to this example. The present invention may be applied to a hybrid vehicle in which the internal combustion engine 41 and the motor generator are mounted as a power source, and an electric vehicle in which only the motor generator is mounted as a power source (without the internal combustion engine). Of course.

11 Vehicle braking device 12 Vehicle 21 Accelerator pedal (acceleration / deceleration operator)
37 Friction braking mechanism (friction braking part)
45 Friction braking member 61 Input / output unit (temperature acquisition unit)
71 Target acceleration / deceleration setting section (braking control section)
73 Acceleration / deceleration control unit (braking control unit)
TG Target deceleration Tpd Pad temperature value (temperature related to friction braking member)

Claims (5)

A friction braking unit that generates a friction braking force by applying a friction braking member to a wheel of the vehicle;
An acceleration / deceleration operator that is operated when accelerating / decelerating the vehicle and in which an acceleration region and a deceleration region are set in an operation range related to the acceleration / deceleration;
A braking control unit that calculates a target deceleration based on a deceleration operation of the acceleration / deceleration operator and performs a braking control based on the calculated target deceleration;
A temperature acquisition unit for acquiring a temperature related to the friction braking member,
The vehicle braking device, wherein the braking control unit reduces the target deceleration when a temperature related to the friction braking member exceeds a predetermined temperature threshold as compared with a case where the temperature is equal to or lower than the temperature threshold. The vehicle braking device according to claim 1,
The total target deceleration in the deceleration region when the temperature related to the friction braking member exceeds the temperature threshold is set to a smaller value than when the temperature related to the friction braking member is equal to or lower than the temperature threshold. A vehicular control device. The vehicle braking device according to claim 1 or 2,
The vehicular braking apparatus, wherein the maximum value of the target deceleration is set to become smaller as the temperature related to the friction braking member becomes higher. The vehicle braking device according to claim 1 or 2,
The maximum value of the target deceleration is set to a common characteristic regardless of the temperature level of the friction braking member,
The vehicular braking apparatus, wherein the target deceleration is set to a characteristic in which an increase amount with respect to a change in the amount of the deceleration operation is nonlinear. The vehicle braking device according to any one of claims 1 to 4,
The braking control unit updates and sets the corrected target deceleration, which is reduced as compared with the case where the temperature relating to the friction braking member exceeds the temperature threshold, compared with the case where the temperature is equal to or lower than the temperature threshold, as the target deceleration. At this time, when the acceleration / deceleration operation element is operated, the target deceleration is decreased so that the target deceleration follows the corrected target deceleration more slowly than when the acceleration / deceleration operation element is not operated. A braking device for a vehicle characterized by the above.

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