JP2006076376A - Brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent response feeling at an initial stage of braking from being varied by a position of a driver's seat. <P>SOLUTION: Since the intensity of jump-in braking force Jp in which braking force rises up abruptly when stepping force of a brake pedal arrives at predetermined stepping force is corrected in an increase direction when it is hard to step the brake pedal because a seat position of the driver's seat is in a rear side and the leg of the driver approaches the pedal in a horizontal direction, lack of the response feeling in the initial state of braking can be compensated to enhance braking feeling. In contrast thereto, since it is corrected in a reduction direction when it is easy to step the brake pedal because the seat position is on a front side and the leg of the driver approaches the pedal in the vertical direction, the response feeling in the initial stage of braking can be suppressed from becoming excessive to enhance the braking feeling. Since the jump-in braking force Jp is corrected in the increase direction as the vehicle speed gets larger, rise-up of the braking force is recognized by an occupant when the brake pedal is stepped in traveling at high speed and safe feeling can be given to the occupant. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention does not generate a braking force until the depression amount from the initial position of the brake pedal reaches a predetermined depression amount, and when the depression amount of the brake pedal reaches the predetermined depression amount, the braking force is increased to the jump-in braking force all at once. The present invention relates to a brake device having a jumping characteristic that starts up and then increases the braking force in accordance with an increase in the amount of depression.

  In a conventional brake device that activates the master cylinder by boosting the pedal pressure of the brake pedal with a negative pressure booster, the braking force is applied to the negative pressure booster until the depression amount from the initial position of the brake pedal reaches the predetermined depression amount. It is not generated, and when the brake pedal depressing amount reaches the predetermined depressing amount, the braking force is increased to the jump-in braking force at once, so that a so-called jumping function is provided so as to enhance the response feeling (biting feeling) at the initial stage of braking. It has been known.

In such a jumping function using a negative pressure booster, the jumping characteristics are fixed and cannot be changed arbitrarily. Therefore, in a so-called brake-by-wire brake device that converts the pedaling force applied by the driver to an electric signal and drives the brake actuator by that electric signal to brake the wheel, the jumping characteristic is made variable. The thing is proposed by the following patent document 1.
JP 2001-509753 A

  By the way, when the driver's seat that can slide back and forth is moved forward, the knee joint of the driver bends and the lower leg part approaches the vertical direction, so that it tends to step on the brake pedal from the top and the pedal force is easily applied. On the other hand, when the driver's seat is moved rearward, the knee joint of the driver extends and the lower leg part approaches to the horizontal, so that it tends to step on the brake pedal from the rear to the front, making it difficult to apply the pedaling force. Also, drivers with tall and long legs have large foot dimensions, which makes it difficult to step on the brake pedal with their toes and tends to step on the soles or lie down on their shoes. It becomes difficult.

  In this way, when it is easy to apply pedal force to the brake pedal, even if the jump-in braking force is the same, it seems that the response at the beginning of braking is high, and conversely, when it is difficult to apply pedal force to the brake pedal, Even if the braking force is the same, there is a problem that the feeling of response at the initial stage of braking is low, and the braking feeling felt by the driver is different.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to prevent a change in response at the initial stage of braking depending on the position of a driver's seat.

  In order to achieve the above object, according to the first aspect of the present invention, the braking force is not generated until the depression amount from the initial position of the brake pedal reaches the predetermined depression amount, and the depression amount of the brake pedal is reduced. When the brake pedal has a jumping characteristic in which the braking force is increased to a jump-in braking force at once when the predetermined depression amount is reached and then the braking force is increased in accordance with the increase of the depression amount, before and after the driver's seat on which the driver is seated A brake device is proposed that includes a seat position sensor that detects a position, and a control unit that corrects the jump-in braking force in accordance with the output of the seat position sensor.

  According to the invention described in claim 2, in addition to the configuration of claim 1, the control means corrects the jump-in braking force in an increasing direction as the seat position detected by the seat position sensor is rearward. A brake device characterized by this is proposed.

  According to a third aspect of the invention, in addition to the configuration of the second aspect, a vehicle speed sensor for detecting a vehicle speed is provided, and the control means increases the jump-in braking force as the vehicle speed detected by the vehicle speed sensor increases. A braking device is proposed which is characterized by correcting in the increasing direction.

  The brake ECU 13 of the embodiment corresponds to the control means of the present invention, and the wheel speed sensors 17f and 17r of the embodiment correspond to the vehicle speed sensor of the present invention.

  According to the first aspect of the present invention, the jump-in braking force when the brake pedal is depressed is corrected according to the front and rear position of the driver seat on which the driver is seated. It is possible to improve the braking feeling by eliminating the difference in the response feeling (biting feeling) at the initial stage of braking that is felt by the driver when it is easy to apply and when it is difficult to apply the pedal force.

  According to the configuration of the second aspect, when the seat position is rearward and the driver's lower leg approaches horizontal, it is difficult to step on the brake pedal, so that the jump-in braking force is corrected in the increasing direction. The braking feeling can be improved by making up for the shortage. Conversely, when the seat position is in front and the driver's lower leg approaches vertical, it is easy to step on the brake pedal, so the jump-in braking force is corrected in a decreasing direction, preventing excessive response at the beginning of braking. Thus, the braking feeling can be enhanced.

  According to the third aspect of the present invention, the jump-in braking force is corrected in the increasing direction as the vehicle speed increases, so that the braking force suddenly rises when the brake pedal is depressed at a low speed, and the passenger is prevented from feeling uncomfortable. In addition, when the brake pedal is depressed at a high speed, it is possible to give the passengers a sense of security by recognizing the rising of the braking force.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 4 show an embodiment of the present invention, FIG. 1 is an overall configuration diagram of a brake-by-wire brake device, FIG. 2 is a side view of a driver seat on which a driver is seated, FIG. Is a graph showing the relationship between the depression force of the brake pedal and the jump-in braking force, and FIG. 4 is a flowchart for explaining the process of calculating the jump-in braking force.

  As shown in FIG. 1, the brake-by-wire brake device includes a brake pedal 11 that is operated by a driver, and the depression force of the brake pedal 11 detected by the depression force sensor 12 is input to the brake ECU 13. The brake ECU 13 operates the brake actuators 15f and 15r connected to the brake calipers 14f and 14r in order to generate a target braking force determined according to the depression force of the brake pedal 11 in the brake calipers 14f and 14r for the front wheels and the rear wheels. Control. The brake actuators 15f and 15r are directly connected to the brake calipers 14f and 14r by the hydraulic pressure that operates the brake calipers 14f and 14r with the hydraulic pressure generated by the electric hydraulic pump or the electric hydraulic cylinder, or with the driving force of the electric motor. A mechanical type to be operated is adopted. In order to give a pseudo stroke and reaction force to the brake pedal 11, the stroke simulator 18 and the brake pedal 11 are connected by a rod 19.

  The brake ECU 13 to which the thrust of the pistons of the brake calipers 14f and 14r for the front wheels and the rear wheels detected by the piston thrust sensors 16f and 16r, that is, the actual braking force generated by the brake calipers 14f and 14r, is input is the actual braking force. The operation of the brake actuators 15f and 15r is feedback-controlled so as to match the braking force. When the brake ECU 13 to which the wheel speeds of the front wheels and the rear wheels detected by the wheel speed sensors 17f and 17r are input, detects that a predetermined wheel has a tendency to lock, the brake ECU 13 reduces the braking force of the wheel and locks it. Execute anti-lock brake control to suppress.

  As shown in FIG. 2, the driver's seat 20 on which the driver is seated can slide back and forth, and the front / rear position is detected by the seat position sensor 21. The front and rear positions of the driver's seat 20 detected by the seat position sensor 21 are input to the brake ECU 13 (see FIG. 1).

  The maps shown in FIGS. 3A to 3C show the relationship between the pedaling force of the brake pedal 11 detected by the pedaling force sensor 12 and the target braking force generated by the brake calipers 14f and 14r. A plurality of maps that are different depending on the seat position detected in (1) are stored in the brake ECU 13 in advance. As is apparent from the figure, the target braking force is maintained at 0 until the pedaling force applied to the brake pedal 11 reaches the jump-in pedaling force F, and when the jump-in pedaling force F is exceeded, the target braking force reaches the jump-in braking force Jp all at once. It increases and then increases linearly as the pedal effort increases. At this time, the jump-in braking force Jp is corrected according to the front-rear position of the driver's seat 20 and is set to be smaller as the driver's seat 20 is in the front and larger as it is in the rear.

  Next, the process of calculating the jump-in braking force Jp will be described based on the flowchart of FIG.

  First, the pedal force of the brake pedal 11 is detected by the pedal force sensor 12 in step S1, the seat position of the driver seat 20 is detected by the seat position sensor 21 in step S2, and the wheel speed detected by the wheel speed sensors 17f and 17r in step S3. The vehicle speed is calculated from In step S4, a target braking force is calculated from the pedaling force. If the target braking force is greater than or equal to the preset minimum jump-in braking force Jpmin in step S5, the jump is performed in step S6 using the seat position coefficient kdL and the vehicle speed V. The in braking force Jp is calculated by the following equation.

Jp = Jpmin + V · kdL
The sheet position coefficient kdL is searched for a map from the sheet position, and is set to be smaller as the position of the front is smaller and larger as it is rearward.

  Accordingly, the jump-in braking force Jp decreases as the seat position is ahead and the vehicle speed is low, and increases as the seat position is rearward and the vehicle speed is high.

  When the jump-in braking force Jp is calculated in this way, the brake actuators 15f and 15r are controlled in step S7, and the brake calipers 14f and 14r are controlled with the jumping characteristics as shown in FIGS. Generate power.

  If the target braking force is less than the minimum jump-in braking force Jpmin in step S5, the brake actuators 15f and 15r are deactivated in step S7, and the brake calipers 14f and 14r do not generate braking force.

  As described above, the jump-in braking force Jp at which the braking force suddenly rises when the driver steps on the brake pedal 11 is corrected according to the front and rear positions of the driver seat 20 on which the driver is seated. Even if the front-rear position changes, it is possible to improve the braking feeling by eliminating the difference in response feeling (biting feeling) at the initial stage of the braking.

  That is, when it is difficult to step on the brake pedal 11 because the driver's seat 20 is behind and the lower leg of the driver approaches horizontal, the jump-in braking force Jp is corrected in the increasing direction, so that the response feeling at the initial stage of braking is insufficient. The braking feeling can be enhanced by supplementing Conversely, when the driver's seat 20 is in front and the driver's lower leg is close to vertical, it is easy to step on the brake pedal 11, so the jump-in braking force Jp is corrected in the decreasing direction, so the response at the beginning of braking is excessive. The braking feeling can be increased by suppressing the braking.

  Also, drivers with long legs have large feet, so it is difficult to step on the brake pedal 11 with their toes, and there is a tendency to step on the soles or lie down on their shoes. Becomes difficult. However, since the driver's seat 20 is positioned backward in the case of a driver with long legs, the difficulty in applying the pedal force to the brake pedal 11 can be offset by correcting the jump-in braking force Jp in the increasing direction, thereby improving the braking feeling. it can.

  Further, as the vehicle speed V increases, the jump-in braking force Jp is corrected in the increasing direction, so that when the brake pedal 11 is depressed at a low speed, the braking force suddenly rises to prevent the passenger from feeling uncomfortable, and When the brake pedal 11 is depressed at a high speed, the occupant can recognize the rising of the braking force to give a sense of security.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiments, a brake-by-wire type brake device is illustrated, but the present invention can also be applied to a normal brake device.

  In the embodiment, the target braking force is set according to the depression force of the brake pedal 11, but the target braking force may be set according to the stroke of the brake pedal 11.

Overall configuration of brake-by-wire brake system Side view of the driver's seat where the driver is seated A graph showing the relationship between the depressing force of the brake pedal and the jump-in braking force Flow chart explaining the process of calculating the jump-in braking force

Explanation of symbols

11 Brake pedal 13 Brake ECU (control means)
17f Wheel speed sensor (vehicle speed sensor)
17r Wheel speed sensor (vehicle speed sensor)
20 Driver's seat 21 Seat position sensor Jp Jump-in braking force V Vehicle speed

Claims (3)

A braking force is not generated until the depression amount from the initial position of the brake pedal (11) reaches a predetermined depression amount, and when the depression amount of the brake pedal (11) reaches the predetermined depression amount, the braking force is jump-in braking force. In a brake device having a jumping characteristic of starting up at a stroke until (Jp) and thereafter increasing the braking force in accordance with the increase in the depression amount,
A seat position sensor (21) for detecting the front-rear position of the driver seat (20) on which the driver is seated, and a control means (13) for correcting the jump-in braking force (Jp) according to the output of the seat position sensor (21). And a brake device.   The brake according to claim 1, wherein the control means (13) corrects the jump-in braking force (Jp) in an increasing direction as the seat position detected by the seat position sensor (21) is rearward. apparatus. A vehicle speed sensor (17f, 17r) for detecting the vehicle speed (V) is provided, and the control means (13) increases the jump-in braking force (Jp) as the vehicle speed (V) detected by the vehicle speed sensor (17f, 17r) increases. The brake device according to claim 2, wherein the braking device corrects in an increasing direction.

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