JP2008222031A - Brake control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake control system capable of carrying out pedal operation of stable and favorable characteristics even in electronically controlling braking force in accordance with the pedal operation. <P>SOLUTION: This brake control system 10a is a brake control system to electronically control the braking force generated by a braking force generating part 14 by an ECU 20 in accordance with operation of a pedal 12, and a contact type spiral spring 36 to energize the pedal 12 in a direction opposite to an operating direction of the pedal 12 is arranged to an oscillating fulcrum of an arm 12b of the pedal 12. The spiral spring 36 performs a function to set characteristics of the trad force of the pedal 12 and a stroke as it is interposed between the pedal 12 and a rod plate 34. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a brake device that electronically controls braking force based on pedal operation.

  2. Description of the Related Art In recent years, a motor cylinder or a hydraulic pump for applying hydraulic pressure to a braking force generator provided on a wheel based on operation information such as a pedaling force of a brake pedal (hereinafter also simply referred to as a pedal) input to an ECU of a vehicle Brake devices that electrically control (electronic control) the motor have been proposed.

  This type of braking power electronically controlled system, the so-called brake-by-wire system, enables braking that is more faithful to pedal operation than a hydraulic control system in which a pedal and master cylinder are directly connected. Thus, smooth braking can be realized.

  In general, a brake device employing a brake-by-wire is provided with a pedal simulator (stroke simulator) for obtaining a reaction force against the pedal depression, and thereby, between the pedal depression amount (stroke, operation amount) and the depression force, Predetermined characteristics (stroke-pedal force characteristics) are given.

  Patent Document 1 describes that a cylinder mechanism including a piston that defines a liquid chamber through which hydraulic fluid is guided and a plurality of disc springs that bias the piston toward the liquid chamber is used as the pedal simulator. Has been. In this case, by laminating the plurality of disc springs, it is possible to reduce the pedal operating torque (stepping rigidity) at the initial step and further increase the pedal operating torque (stepping rigidity) when the pedal is depressed. Pedal characteristics (stroke-depression force characteristics) can be obtained.

Japanese Patent Laid-Open No. 6-211124

  However, in the brake device described in Patent Document 1, since a plurality of disc springs are used in an overlapping manner, the spring constant may vary. For this reason, there is a possibility that the obtained pedal characteristic changes every time the vehicle is depressed or every vehicle, and the obtained pedal operation feeling may not be constant.

  The present invention has been made in order to solve the above-described conventional problems, and provides a brake device capable of stable and good pedal operation even when the braking force is electronically controlled based on the pedal operation. The purpose is to provide.

  The brake device according to the present invention is a brake device that electronically controls a braking force based on pedal operation, and a contact type that urges the pedal in a direction opposite to the stepping-on direction of the pedal with respect to the swinging fulcrum of the pedal. The spiral spring is arranged.

  According to such a configuration, the reaction force due to the torsional torque of the contact-type spiral spring is applied to the pedal when the system in which the braking force is electronically controlled is on. For this reason, without mounting a pedal simulator or the like that generates a pedal reaction force, the pedaling force and stroke characteristics of the pedal can be made stable and good, and the operational feeling of the pedal can be improved.

  According to the present invention, in the brake device that electronically controls the braking force, the contact-type spiral spring is disposed with respect to the swing fulcrum of the pedal. As a result, a reaction force due to the twisting torque of the spiral spring can be applied to the pedal, and the pedal operation feeling can be improved with the pedaling force and stroke characteristics of the pedal being stable and good characteristics.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a brake device according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block circuit diagram of a brake device 10a according to the first embodiment of the present invention. The brake device 10a according to the present embodiment is mounted on a vehicle such as an automobile, and a braking force generator (provided on the left wheel LW and the right wheel RW) based on the operation of the pedal (brake pedal) 12 by the driver (operator) ( Calipers, wheel cylinders, brake cylinders) 14L, 14R are devices that brake the vehicle by pinching the disks 15L, 15R to generate braking force. In FIG. 1, only the left wheel LW and the right wheel RW constituting the front wheel side of the automobile are shown, and the rear wheel side is not shown, but the rear wheel side is also the front wheel side (left The wheel LW and the right wheel RW) can have the same configuration or other configurations. Further, in the brake device 10a according to the present embodiment, the reference sign of what is provided on the left wheel LW side is denoted by “L”, and the reference sign of what is provided on the right wheel RW side is denoted by “R”. When the left wheel LW side and the right wheel RW side are described together, the above “L” and “R” are omitted.

  The brake device 10a includes an operation unit 11a having a pedal 12 that a driver operates according to a driving situation, the master cylinder 16 that is driven in conjunction with the operation of the pedal 12, and the braking force generation units 14L and 14R. Pumps (hydraulic pressure generating units, hydraulic pumps) 18L and 18R for applying a hydraulic pressure for generating a braking force. Each component of the brake device 10a is electrically connected to the ECU 20 which is a control unit, and is controlled by the ECU 20.

  That is, the brake device 10a includes a hydraulic pressure (hydraulic pressure) system that connects hydraulic pressure (hydraulic pressure) between the components and an electric system that electrically connects the components and the ECU 20. The In FIG. 1, a path (flow path) constituting the hydraulic system is indicated by a solid line, and a path (signal line) constituting the electrical system is indicated by a broken line. Examples of the liquid filled in the hydraulic system include brake fluid.

  As shown in FIG. 2, the operation unit 11 a includes a pedal 12, a rod plate 34 that can rotate (swing) coaxially with the pedal 12, and a contact type that is interposed between the pedal 12 and the rod plate 34. The spiral spring 36 is provided.

  As shown in FIG. 1, the pedal 12 is provided with a pedal operation information detection unit 22 that detects a driver's depression force (depression force) and an operation amount (stroke) of the pedal 12 by the driver. The detection value of the operation information detection unit 22 is input to the ECU 20. For example, a torque sensor provided on the tread surface of the pedal 12 is used for the detection of the pedal force, and a potentiometer or an encoder for detecting the rotation angle of the pedal 12 is used for the detection of the stroke, for example. Note that the pedal operation information detection unit 22 may be configured to detect only the pedal effort.

  As shown in FIG. 2, in the pedal 12, a slightly large-diameter hole 38 along the axial direction of the center of rotation of the pedal 12 is provided on the swing base end side of the arm 12 b that supports the plate 12 a that the driver steps on with the foot. Is provided. An annular convex portion 40 is provided on the peripheral edge of the hole 38 opposite to the rod plate 34 side.

  In the rod plate 34, a rod-shaped connecting shaft portion 42 that protrudes along the axial direction of the rotation center of the rod plate 34 is provided on the side surface on the pedal 12 side. A support shaft 43 that is shorter than the connection shaft portion 42 and coaxial with the connection shaft portion 42 is provided on the side surface opposite to the side on which the connection shaft portion 42 protrudes.

  Further, an engaging groove 44 is formed along the axial direction on the inner peripheral surface of the hole 38 and the annular convex portion 40 of the pedal 12, and the connecting shaft 42 of the rod plate 34 has an axial direction. An engaging groove portion 46 is formed that divides the connecting shaft portion 42 into two forks from the tip surface to a predetermined length. Therefore, the engagement piece 36 a on the winding start side of the spiral spring 36 is engaged with the engagement groove portion 46 of the connecting shaft portion 42, and the engagement end portion of the spiral spring 36 is engaged with the engagement groove portion 44 of the hole 38. With the piece 36b engaged, the connecting shaft portion 42 and the spiral spring 36 are inserted into the hole 38, whereby the pedal 12 and the rod plate 34 are integrally connected via the spiral spring 36 (see FIG. 3). Thereby, the pedal 12 is given a biasing force by the spiral spring 36 in the direction (arrow X2 direction) opposite to the depression direction (arrow X1 direction in FIG. 2).

  As shown in FIG. 3, the operation portion 11 a in which the pedal 12 and the rod plate 34 are connected in this way has the connection shaft portion 42 and the support shaft portion 43 of the rod plate 34 protruding on both sides of the brackets 48 and 50. It is fixed to the vehicle body in a swingable state by being pivotally supported by the holes 48a and 50a. The connecting shaft portion 42 and the support shaft portion 43 are fixed to the brackets 48 and 50 from the holes 48a and 50a by lock washers 52 and 54.

  Furthermore, as shown in FIGS. 2 to 4, on the side surface of the pedal 12 that faces the rod plate 34, the swinging direction of the pedal 12 (in the direction of arrow X in FIGS. 2 and 4) is slightly below the hole 38. A serrated locking portion 56 is provided. As will be described later, the locking portion 56 functions as a part of the ratchet mechanism in the operation portion 11a.

  The locking portion 56 is formed with a locking surface 56a that is suspended from the side surface of the arm 12b on the stepping side (arrow X1 side) of the pedal 12, and on the return side (arrow X2 side) of the pedal 12. A plurality of convex portions each having an inclined surface 56b that smoothly inclines from the top of 56a toward the side surface of the arm 12b are configured. In FIG. 4, the number of the convex portions constituting the locking portion 56 is three, but may be one or two, or even four or more.

  At a position corresponding to the locking portion 56 of the rod plate 34, an advancing / retreating drive means 58 for driving the rod 58a protruding toward the locking portion 56 to advance / retreat by excitation of the solenoid 58b is provided. The advancing / retreating drive means 58 is fixed to the rod plate 34 by a bolt 63 via a bracket plate 61 (see FIG. 4). The solenoid 58b is electrically connected to the ECU 20 and a power source such as a battery (not shown) via a signal line (not shown). In the rod plate 34, a hole 41 formed below the advance / retreat driving means 58 is for attaching a bolt or the like for connecting the rod 28 of the master cylinder 16 described later.

  In such a forward / backward drive means 58, when the solenoid 58b is not excited, the rod 58a extends toward the pedal 12 by the biasing force of the spring 58c and abuts against the locking portion 56 (see the two-dot chain line in FIG. 4). ). On the other hand, when the solenoid 58b is excited, the rod 58a contracts against the urging force of the spring 58c and is separated from the locking portion 56 (see the solid line in FIG. 4).

  The spiral spring 36 connecting the pedal 12 and the rod plate 34 is configured by winding a flat metal plate (plate spring) spirally from the engagement piece 36a side to the engagement piece 36b side. This is a contact-type spiral spring that urges the pedal 12 in the direction (arrow X2 direction) opposite to the depression direction (arrow X1 direction in FIG. 2). In the spiral spring 36, when an external force is further applied in the winding direction (the direction of the arrow X1 in FIG. 2), the metal plates gradually come into contact with each other, and the spring becomes hard as the contact resistance increases. That is, the spring constant increases.

  Therefore, in the operation portion 11a in which the spiral spring 36 is interposed, as shown in FIG. 5, the initial stage when the pedal 12 is operated (when the pedal 12 is depressed), that is, the pedaling force of the pedal 12 is low, and the set load of the spiral spring 36 When it is less than (point A1 in FIG. 5), the winding angle of the spiral spring 36 hardly changes, and similarly, the operation amount of the pedal 12 hardly changes. In this case, the set load of the spiral spring 36 is a load (load from the pedal 12 to the spiral spring 36) at which the amount of operation of the pedal 12 can start to change when the pedal 12 is depressed and the operation amount of the pedal 12 begins to change. is there.

  Next, when the spiral spring 36 exceeds the set load (point A1 in FIG. 5) by further operation (depression) of the pedal 12, the torsion torque of the spiral spring 36 is moderate in a state where the metal plates are not in contact with each other. Therefore, the pedal 12 can be operated with a light operating torque (step rigidity) (between points A1 and A2 in FIG. 5). That is, in a region where the pedal 12 is not depressed and the deceleration (acceleration in the deceleration direction) is low, the pedal 12 can be operated with a light operating torque (step rigidity), and good operability can be obtained.

  Subsequently, when the pedal 12 is further depressed, the metal plates of the spiral spring 36 start to contact each other (point A2 in FIG. 5), the contact resistance gradually increases, and the torsion torque of the spiral spring 36 becomes smooth. And it begins to rise rapidly. Normally, such a region is a region where the driver wants to generate a high deceleration by depressing the pedal 12 greatly and strongly. Accordingly, the torsional torque of the spiral spring 36 increases as the pedaling force of the pedal 12 increases, so that the operating torque (stepping rigidity) of the pedal 12 can be appropriately increased, and the driver has a hard, strong and good operational feeling. Can be obtained. Thereafter, the pedal 12 is further depressed. For example, at the point A3 in FIG. 5, the metal plates of the spiral spring 36 are completely in contact with each other, that is, the point A3 becomes the depression limit (maximum stroke position) of the pedal 12. .

  Thus, in the brake device 10a according to the present embodiment, by using the spiral spring 36, it becomes possible to obtain a good non-linear pedaling force-stroke characteristic as shown in FIG. It is possible to obtain an optimum feeling of operation according to the pedal effort.

  Returning to FIG. 1, the master cylinder 16 includes two pistons 26L and 26R arranged in order in the axial direction, a rod 28 whose rear end is connected to the rod plate 34 and drives the pistons 26L and 26R to advance and retreat, and the cylinder 16a. Is composed of two pressurizing chambers 30L and 30R which are partitioned by the pistons 26L and 26R. The pressurizing chambers 30L and 30R are provided with return springs (elastic members) 32L and 32R that return the pistons 26L and 26R that have been moved by the depression of the pedal 12 to their original positions.

  The pressurizing chambers 30L and 30R are connected to the braking force generators 14L and 14R by main paths 33L and 33R. Furthermore, passages 53L and 53R connected to the reservoir tank 51 communicate with the pressurizing chambers 30L and 30R. The reservoir tank 51 functions to adjust the hydraulic pressure (fluid amount) of the hydraulic system of the brake device 10a. Furthermore, the reservoir tank 51 is connected to paths 57L and 57R communicating with the primary side (suction side) of the pumps 18L and 18R. These paths 53L and 53R and paths 57L and 57R are joined together before being connected to the reservoir tank 51.

  In the path 53 connected to the reservoir tank 51, the opening communicating with the pressurizing chamber 30 is formed close to the original position of the piston 26. As a result, when the pistons 26L and 26R advance from their original positions (if they move slightly), the opening is closed, that is, the paths 53L and 53R are blocked between the pressurizing chambers 30L and 30R and the reservoir tank 51. Is done.

  In this case, by setting the set load of the return spring 32 of the master cylinder 16 to be lower (smaller) than the set load of the spiral spring 36, the piston 26 of the master cylinder 16 starts moving as soon as the pedal 12 is depressed, At this point, the path 53 is immediately cut off, and as a result, the piston 26 is fixed. Accordingly, since the rod plate 34 is also fixed, the pedal 12 is further stepped on, and the spiral spring 36 starts when the pedaling force of the pedal 12 becomes higher than the set load (point A1 in the figure) of the spiral spring 36. The spiral spring 36 makes it possible to obtain desired pedaling force and operation amount characteristics.

  In the main paths 33L and 33R, valves 59L and 59R are disposed on the master cylinder 16 side of the paths 57L and 57R, and a first linear is provided on the braking force generators 14L and 14R side of the paths 57L and 57R. Solenoid valves 60L and 60R are provided. On the braking force generators 14L, 14R side of the first linear solenoid valves 60L, 60R, the second linear solenoid valves 64L, 64R are disposed on the paths 62L, 62R branched from the main paths 33L, 33R. The paths 62L and 62R merge with the paths 57L and 57R and communicate with the reservoir tank 51.

  The valve 59 communicates or blocks the main path 33 when the solenoid 59a is excited (driven) under the control of the ECU 20. On the other hand, in the first linear solenoid valve 60, when the linear solenoid 60a is excited under the control of the ECU 20, the degree of restriction (flow) between the connecting part of the path 57 and the connecting part of the path 62 in the main path 33 is determined. Adjust the path diameter. Similarly, the second linear solenoid valve 64 adjusts the degree of restriction (flow path diameter) of the path 62 when the linear solenoid 64a is excited under the control of the ECU 20. In this way, the first and second linear solenoid valves 60 and 64 function as variable throttle valves that adjust the degree of throttling of the paths in which they are disposed.

  In FIG. 1, for simplicity, signal lines and the like connected from the solenoid 59a and the linear solenoids 60a and 64a to the ECU 20 are omitted.

  In the brake device 10a configured as described above, a pedaling force and a stroke, which are operation information of the pedal 12, are normally detected by the pedal operation information detection unit 22 and input to the ECU 20. Then, the pump 18 is driven based on a command from the ECU 20, the braking force generation unit 14 generates a braking force, and a braking operation is performed. That is, the brake device 10a is configured as a system (brake-by-wire) that employs the by-wire technology, and is a device that electronically controls the braking force based on the operation of the pedal 12.

  Then, next, the fundamental operation | movement and effect of the brake device 10a which concern on this embodiment are demonstrated.

  First, the normal time (system on) when the brake device 10a is electronically controlled as brake-by-wire will be described.

  When the system is turned on, first, under the control of the ECU 20, the valve 59 is closed and the main path 33 is shut off. Further, the solenoid 58b constituting the advance / retreat driving means 58 is excited to retract the rod 58a against the urging force of the spring 58c, and away from the locking portion 56 (solid line position in FIG. 4).

  In this state, when the driver operates the pedal 12, the set load of the return spring 32 of the master cylinder 16 is set lower than the set load of the spiral spring 36 as described above. At the same time, the piston 26 of the master cylinder 16 starts moving, the path 53 to the reservoir tank 51 is blocked, and the piston 26 is fixed. Accordingly, the rod plate 34 is also fixed, and its swinging is restricted. That is, at the same time as the pedal 12 is operated, the piston 26 moves forward from the original position, so that the path 53 communicating from the pressurizing chamber 30 to the reservoir tank 51 is blocked. Here, since the main path 33 is blocked by the valve 59, there is no supply destination of the hydraulic pressure generated in the pressurizing chamber 30 of the master cylinder 16, that is, the piston 26 is in the forward / backward drive stopped state. Therefore, the rod plate 34 is in a fixed state (oscillation stopped state) without being able to drive the master cylinder 16 forward and backward.

  When the pedal 12 is further depressed in the state in which the rod plate 34 is fixed by the master cylinder 16 as described above, and the operating force of the pedal 12 exceeds the set load (point A1 in the figure) of the spiral spring 36, the pedal 12 A rotation angle difference is generated between the rod plate 34 and a spiral spring 36. That is, the spiral spring 36 is started to wind. Therefore, as shown in FIG. 5, the pedal 12 is given a reaction force (rotational torque) due to the torsional torque of the spiral spring 36, and the pedaling force and stroke characteristics are set by the spiral spring 36. The pedal 12 can be operated with an optimum feeling.

  At the same time, the operation information (stepping force and stroke) of the pedal 12 is input to the ECU 20 from the pedal operation information detection unit 22 by the driver's operation of the pedal 12. The ECU 20 controls the drive of the pump 18 based on the input operation information of the pedal 12, and optimally controls the opening degree of the linear solenoids 60a and 64a constituting the first and second linear solenoid valves 60 and 64 which are throttle valves. . Accordingly, since the first and second linear solenoid valves 60 and 64 control the degree of restriction on the primary side and the secondary side of the pump 18, the hydraulic pressure of the pump 18 is determined by a desired hydraulic pressure determined by the ECU 20. Is applied to the braking force generation unit 14, and a desired braking force is generated by the braking force generation unit 14, and the left wheel LW and the right wheel RW are braked.

  Second, a state where the brake device 10a is not electronically controlled as brake-by-wire (when the system is off) will be described. Examples of the system-off time include a so-called failure time such as when the pump 18 fails or malfunctions, or when the system is stopped when the ignition is off.

  When the system is off, the valve 59 is opened (opened) and the main path 33 is communicated. Further, when the solenoid 58b constituting the advance / retreat driving means 58 is de-energized, the rod 58a extends to the pedal 12 side by the urging force of the spring 58c and abuts against the locking portion 56 (two-dot chain line in FIG. 4). position).

  When the driver operates the pedal 12 in this state, the extended rod 58a of the rod plate 34 is in contact with the locking surface 56a constituting the locking portion 56 of the pedal 12, so that the pedal 12 The pedal 12 and the rod plate 34 oscillate together in the stepping-in direction (the direction of the arrow X1 in FIGS. 2 and 4). Accordingly, the operation of the pedal 12 is transmitted from the rod plate 34 to the master cylinder 16 without being absorbed by the spiral spring 36. As a result, the hydraulic pressure generated in the pressurizing chamber 30 of the master cylinder 16 is applied to the braking force generation unit 14, and the braking force generation unit 14 generates the braking force to brake the left wheel LW and the right wheel RW. . Since the reaction force to the pedal 12 can be obtained by the master cylinder 16, the driver can operate the pedal 12 reliably and satisfactorily.

  When the pedal 12 is returned (in the direction of the arrow X2 in FIGS. 2 and 4), the extended rod 58a of the rod plate 34 is elastically supported in the extended direction by the spring 58c, while the engaging portion 56 of the pedal 12 is engaged. The pedals 12 can be reliably returned to their initial positions since the respective inclined surfaces 56b constituting the above are sequentially climbed. Naturally, when the pedal 12 returned to the initial position is depressed again, the engaging surface 56a of the pedal 12 and the rod 58a of the rod plate 34 are in contact with each other, so the pedal 12 and the rod plate 34 are integrated. And can be swung. That is, in the brake device 10a, when the system is off, such as when a failure occurs, the latching portion 56 of the pedal 12 and the advance / retreat driving means 58 of the rod plate 34 function as a so-called ratchet mechanism, so Operation and return operation are possible.

  Third, the case where the system is turned off due to a sudden failure during the operation of the pedal 12 (for example, during the depression) when the system is on will be described. In such a case, the pump 18 may suddenly stop during the operation of the pedal 12, and the hydraulic pressure to the braking force generator 14 may not be supplied, making it impossible to brake the vehicle.

  However, in the brake device 10a according to the present embodiment, the system fails, the pump 18 stops, and at the same time, the valve 59 is opened and the solenoid 58b constituting the advance / retreat drive means 58 is de-energized. As a result, the rod 58a is extended toward the pedal 12 by the urging force of the spring 58c and comes into contact with the locking portion 56, whereby the rod plate 34 and the pedal 12 are engaged and can swing together. Therefore, even if the pedal 12 suddenly fails during operation, the pedal 12 can be depressed as it is, and the hydraulic pressure from the master cylinder 16 can be applied to the braking force generator 14 to reliably obtain the braking force. Become.

  In addition, when the advancing / retreating drive means 58 of the rod plate 34 is engaged with the locking portion 56 of the pedal 12 at an irregular position (halfway position) due to the sudden system failure as described above. Even so, the ratchet mechanism allows the pedal 12 to be easily and reliably returned to the initial position.

  As described above, in the brake device 10a according to the present embodiment, the valve 59 is closed and the main path 33 is shut off and the advance / retreat drive means 58 is configured when the system is turned on in which the braking force is electronically controlled as a brake-by-wire. The solenoid 58 b is excited and the rod 58 a is separated from the locking portion 56. As a result, the rod plate 34 is fixed by the master cylinder 16, and the pedal 12 and the rod plate 34 produce a rotation angle difference via the spiral spring 36. Accordingly, a reaction force due to the torsion torque of the spiral spring 36 is applied to the pedal 12 and the pedaling force and stroke characteristics are good as shown in FIG. 5, so that the driver can reliably operate the pedal 12 with an optimum feeling. It can be carried out.

  Further, in the brake device 10a, when the system is off such as when a failure occurs, the locking portion 56 of the pedal 12 and the advance / retreat driving means 58 of the rod plate 34 function as a ratchet mechanism. Accordingly, the pedal 12 and the rod plate 34 can swing substantially integrally when the pedal 12 is depressed, while the pedal 12 can swing independently of the rod plate 34 when the pedal 12 is returned. The stepping-in operation and the returning operation can be performed reliably. Further, even when such a system-off occurs suddenly during the operation of the pedal 12, it is possible to reliably perform the depressing operation and the returning operation of the pedal 12. In this case, when the pedal 12 is depressed, the hydraulic pressure generated in the master cylinder 16 can be applied to the braking force generation unit 14, thereby generating the braking force. Even in this case, reliable braking is possible.

  Next, a second embodiment of the present invention will be described mainly with reference to FIGS. FIG. 6 is a schematic exploded perspective view of the operation unit 11b provided in the brake device 10b according to the second embodiment. FIG. 7 is a partially omitted cross-sectional view taken along line VII-VII in FIG. 6 and 7, the same reference numerals as those shown in FIGS. 1 to 4 indicate the same or similar configurations, and thus the same or similar functions and effects are provided. The detailed explanation is omitted.

  The operation part 11b which comprises the brake device 10b which concerns on this embodiment is not provided with the said latching | locking part 56 and the advancing / retreating drive means 58. FIG. As shown in FIGS. 6 and 7, in the operation portion 11b, a housing 70 having a slightly large-diameter cylindrical shape protrudes on the side surface opposite to the annular convex portion 40 with the hole 38 of the pedal 12 interposed therebetween. Is done. On the other hand, on the side where the connecting shaft portion 42 of the rod plate 34 protrudes, a connecting convex portion 72 that is coaxial with the connecting shaft portion 42 and shorter than the connecting shaft portion 42 and has a large diameter is provided.

  Therefore, in the operation portion 11b, when the pedal 12 and the rod plate 34 are connected via the spiral spring 36, the connecting projection 72 of the rod plate 34 is fitted in the housing 70 of the pedal 12, as shown in FIG. The housing 70 is closed by being inserted. At this time, a seal ring (oil) is formed between the annular convex portion 40 of the pedal 12 and the connecting shaft portion 42 of the rod plate 34 and between the housing 70 of the pedal 12 and the connecting convex portion 72 of the rod plate 34. Seals 74 and 76 are fitted. As a result, a sealed space in which the spiral spring 36 is housed is formed inside the housing 70.

  In such an operation portion 11b, the magnetic fluid M is sealed in the sealed space formed inside the housing 70, and the magnetic fluid M sufficiently enters between the metal plates of the spiral spring 36. is doing. The magnetic fluid M is a fluid whose viscosity resistance changes when a magnetic field is applied, and the viscosity resistance increases as the strength of the magnetic field increases. As the magnetic fluid M, oil mixed with iron powder or the like is used.

  Further, in the operation portion 11b, a cylindrical magnetic coil 78 is disposed around the housing 70 in which the magnetic fluid M is enclosed. Therefore, when the magnetic coil 78 is energized under the control of the ECU 20 and the magnetic field applied to the magnetic fluid M changes, the viscous resistance of the magnetic fluid M in which the spiral spring 36 is immersed changes. For this reason, when the viscous resistance of the magnetic fluid M increases, the spiral spring 36 becomes hard (high spring constant), and when the viscous resistance of the magnetic fluid M decreases, the spiral spring 36 becomes soft (low spring constant). . In other words, in the case of the present embodiment, the spring constant of the spiral spring 36 can be changed if the magnetic field applied to the magnetic fluid M is appropriately changed by energizing the magnetic coil 78 constituting the operation portion 11b. Therefore, it is possible to change the operation torque (stepping rigidity) of the pedal 12.

  By the way, when the pedaling force and stroke characteristics of the pedal 12 are set only by the spiral spring 36 as in the brake device 10a according to the first embodiment, the pedal operation is performed slowly and slowly over a normal time. Sometimes, the characteristics are good as shown by the line B1 in FIG. However, when the pedal 12 is depressed quickly and quickly, the characteristics of the pedaling force and the stroke may fluctuate greatly as shown by the line C in FIG. 8, and it may not be possible to obtain a good operational feeling. is there.

  However, in the brake device 10b according to the present embodiment, the magnetic field applied to the magnetic fluid M from the magnetic coil 78 constituting the operation unit 11b is changed under the control of the ECU 20 based on the detection value of the pedal operation information detection unit 22 and the like. Thus, an appropriate viscosity can be imparted to the magnetic fluid M. As a result, the spring constant of the spiral spring 36 is moderately improved to increase the operating torque (stepping rigidity) of the pedal 12, and the pedal 12 is given a feeling of operation firmly. As shown by the line B2 in FIG. It is possible to correct to a characteristic.

  Further, in the brake device 10b according to the present embodiment, the pedal force and stroke characteristics of the pedal 12 can be made variable based on, for example, a detection result of a switch or pedal operation information detection unit 22 (not shown). For example, without applying a magnetic field to the magnetic fluid M, appropriately change the applied magnetic field to the magnetic fluid M under the control of the normal mode and the normal mode set to the normal characteristic indicated by the line D1 in FIG. It is also possible to be configured to be able to switch to an emergency mode set to a characteristic in which the operating torque (stepping rigidity) of the pedal 12 indicated by a line D2 in FIG. 9 is increased.

  As described above, according to the brake device 10b according to the present embodiment, the spring constant of the spiral spring 36 is changed by changing the magnetic field applied to the magnetic fluid M, and the pedal force and stroke characteristics of the pedal 12 are appropriately set. Can be controlled.

  Further, when the magnetic field applied to the magnetic fluid M is strengthened to the maximum, the spiral spring 36 is completely cured, and the pedal 12 and the rod plate 34 can be swung substantially integrally. Accordingly, when the system is off, such as when the failure occurs, the ratchet mechanism is constituted by the locking portion 56 constituting the brake device 10a and the forward / backward drive means 58 of the rod plate 34 by changing the magnetic field applied to the magnetic fluid M. And substantially the same operation is possible. That is, when the pedal 12 is depressed, the magnetic field applied to the magnetic fluid M is maximally strengthened so that the pedal 12 and the rod plate 34 can swing substantially integrally. When the pedal 12 is returned, the magnetic field applied to the magnetic fluid M By eliminating the above, the pedal 12 and the rod plate 34 can swing independently of each other, and the pedal 12 can be reliably returned to the initial position. For this reason, in the brake device 10b according to the present embodiment, the locking portion 56 and the advance / retreat driving means 58 in the brake device 10a according to the above-described embodiment can be omitted, and the mechanism can be simplified. .

  It should be noted that the hydraulic system and the electrical system circuit of the brake devices 10a and 10b according to the above-described embodiment can naturally have a configuration other than that shown in FIG. 1. For example, the hydraulic pressure is applied to the braking force generator 14. Instead of the pump 18, a cylinder driven by a motor (motor cylinder) or the like may be used as the hydraulic pressure generating unit to be applied.

  The braking force generator 14 may be a wheel cylinder that causes a shoe to come into contact with the drum as a drum brake, in addition to a caliper that holds the disc 15 as a so-called disc brake.

  As described above, the present invention has been described with the embodiment. However, the present invention is not limited to this, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

1 is a block circuit diagram of a brake device according to a first embodiment of the present invention. FIG. 3 is a schematic exploded perspective view of an operation unit provided in the brake device according to the first embodiment of the present invention. FIG. 3 is a partially omitted sectional view taken along line III-III in FIG. 2. FIG. 4 is a partially omitted cross-sectional view taken along line IV-IV in FIG. 3. It is a graph which shows the relationship between the winding angle of a spiral spring, and torsion torque, and the relationship between the pedal effort and stroke. It is a general | schematic disassembled perspective view of the operation part with which the brake device which concerns on the 2nd Embodiment of this invention is equipped. FIG. 7 is a partially omitted sectional view taken along line VII-VII in FIG. 6. It is the graph which compared the pedaling force of the pedal by the presence or absence of the magnetic field application to a magnetic fluid, and the relationship of a stroke. In the brake device shown in FIG. 6, it is a graph in the state which set the relationship of the pedal effort and stroke to two modes.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10a, 10b ... Brake apparatus 11a, 11b ... Operation part 12 ... Pedal 14L, 14R ... Braking force generation part 16 ... Master cylinder 18L, 18R ... Pump 20 ... ECU22 ... Pedal operation information detection part 34 ... Rod plate 36 ... Spiral spring 56 ... Locking portion 58 ... Advancing / retracting drive means 59L, 59R ... Valve 70 ... Housing 78 ... Magnetic coil

Claims (1)

A brake device that electronically controls braking force based on pedal operation,
A brake device comprising a contact-type spiral spring that urges the pedal in a direction opposite to a pedal depression direction with respect to a swinging fulcrum of the pedal.

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