JP2007182227A - De-freezing device and freezing detection device in electric parking brake apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely detect the freezing of a brake operating force transmission system of an electric parking brake apparatus and surely de-freeze the system. <P>SOLUTION: This electric parking brake apparatus operates wheel brakes by driving the brake operating force transmission system in one direction by a brake operating force generated by an electric motor, to hold the brake operating force by an electromagnetic brake when the electric motor is stopped. While operating the electric parking brake apparatus, the presence or absence of the freezing of the brake operating force transmission system is determined based on the movement amount of the brake operating force transmission system by the time when a predetermined time is passed after the electromagnetic brake is released S7. If a freezing occurs, the ice adhered to the brake operating force transmission system is crushed for de-freezing by driving the electric motor in one direction to further pull the brake operating force transmission system S11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric parking brake device that operates a wheel brake by driving a brake operating force transmission system in one direction with a brake operating force generated by an electric motor, and more particularly, an apparatus for releasing freezing of the brake operating force transmission system. And an apparatus for detecting freezing.

  In a parking brake device of a vehicle, a brake pedal, a brake lever, and a wheel brake are connected by a brake operating force transmission system including a Bowden wire. If the temperature drops while parking with the parking brake device operating in a cold region, the brake operating force transmission system near the wheel brake that is exposed outside the vehicle and tends to adhere to moisture may freeze. Even if the brake pedal or the brake lever is returned to the brake release position in an attempt to start the vehicle from the state, the wheel brake may remain in the activated state. When the vehicle starts in this state, if the driver does not notice it abnormally due to insufficient acceleration, etc., the vehicle will run while dragging the wheel brake and a fade phenomenon will occur (a phenomenon in which the effectiveness of the brake decreases due to frictional heat on the friction surface). there's a possibility that.

  Therefore, Japanese Patent Laid-Open No. 3-7654 discloses that three conditions are satisfied: “the parking brake device is in an operating state”, “the outside air temperature is below the freezing temperature”, and “the engine is not operating”. There has been proposed an alarm device that prevents the brake operating force transmission system from freezing in advance by issuing an alarm to the driver so as to release the operation of the parking brake device.

  However, in the device described in Japanese Patent Laid-Open No. 3-7654, the alarm device does not operate if the outside air temperature exceeds the freezing temperature when the vehicle is parked, so the driver operates the parking brake device. However, when the outside air temperature decreases from midnight to early morning and the brake operating force transmission system freezes, there is a possibility that the driver may travel while dragging the wheel brake without noticing that.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to reliably detect freezing of the brake operating force transmission system and to reliably release the generated freezing in an electric parking brake device.

  In order to achieve the above object, according to the first aspect of the present invention, an electric parking brake device that operates a wheel brake by driving a brake operating force transmission system in one direction with a brake operating force generated by an electric motor. , The freezing detecting means for detecting freezing of the brake operating force transmission system, and when the freezing detecting means detects the freezing of the brake operating force transmission system, the electric motor is driven to increase the brake operating force in the one direction. There is proposed a freeze release device in an electric parking brake device, characterized in that the freeze release means is provided.

  According to the above configuration, when the freezing detection means detects freezing of the brake operating force transmission system, the freeze release means drives the electric motor to drive the brake operating force transmission system in one direction (direction in which the wheel brake is operated). Thus, the brake operating force is increased, so that the ice freezing the brake operating force transmission system can be crushed to release the freeze.

  According to the second aspect of the present invention, there is provided an electric parking brake device that operates a disc-type wheel brake by driving a brake operating force transmission system in one direction with a brake operating force generated by an electric motor, The wheel brake functions as a service brake by the hydraulic pressure supplied from the hydraulic power source, functions as a parking brake by the brake operating force transmitted by the brake operating force transmission system, and brakes when functioning as a service brake by supplying hydraulic pressure. When driving the operating force transmission system in the other direction, freezing detection means for detecting freezing of the brake operating force transmission system, and when the freezing detection means detects freezing of the brake operating force transmission system, hydraulic pressure is applied to the wheel brakes. And an anti-freezing means for supplying and driving the brake operating force transmission system in the other direction. Frozen release device in the vehicle brake system is proposed.

  According to the above configuration, when the disc-type wheel brake functioning as a service brake by hydraulic pressure and functioning as a parking brake by the brake operation force transmission system functions as a service brake, the brake operation force transmission system is moved in the other direction (wheel (In the direction in which the brake is released), when the freeze detecting means detects that the brake operating force transmission system is frozen, the freeze releasing means supplies hydraulic pressure to the wheel brake to By generating a load in a direction to release the operation of the brake, the ice freezing the brake operating force transmission system can be crushed to release the freeze.

  According to a third aspect of the invention, there is provided an electric parking brake device for operating a disc-type wheel brake by driving a brake operating force transmission system in one direction with a brake operating force generated by an electric motor, The wheel brake functions as a service brake by the hydraulic pressure supplied from the hydraulic power source, functions as a parking brake by the brake operating force transmitted by the brake operating force transmission system, and brakes when functioning as a service brake by supplying hydraulic pressure. In the case where the operating force transmission system is driven in the other direction, the freezing detection means for detecting freezing of the brake operating force transmission system, and the electric motor is driven when the freezing detection means detects freezing of the brake operating force transmission system. Increase the brake operating force in one direction and supply hydraulic pressure to the wheel brake to transmit the brake operating force Unfreeze device is proposed in the electric parking brake system, wherein a and a freeze release means for driving in the other direction.

  According to the above configuration, when the disc-type wheel brake functioning as a service brake by hydraulic pressure and functioning as a parking brake by the brake operation force transmission system functions as a service brake, the brake operation force transmission system is moved in the other direction (wheel (In the direction in which the brake operation is released), when the freeze detecting means detects that the brake operating force transmission system is frozen, the freeze releasing means drives the electric motor to drive the brake operating force transmission system. Is driven in one direction (the direction in which the wheel brake is operated) to increase the brake operating force, and hydraulic pressure is supplied to the wheel brake to generate a load in the direction to release the wheel brake in the brake operating force transmission system. As a result, the ice that freezes the brake operating force transmission system can be crushed to release the freeze.

  According to a fourth aspect of the invention, the brake operating force transmission system is driven in one direction by the brake operating force generated by the electric motor to operate the wheel brake, and the brake operating force holding means is operated when the electric motor is stopped. In the electric parking brake device that holds the brake operating force in the above, the brake operating force is transmitted until a predetermined time elapses after the drive of the electric motor is stopped and the holding of the brake operating force by the brake operating force holding means is released. A freezing detection device in an electric parking brake device is proposed, wherein the presence or absence of freezing of the brake operating force transmission system is determined based on the amount of movement of the system.

  According to the above configuration, the amount of movement of the brake operating force transmission system from when the electric motor drive stop and the release of the brake operating force holding means of the brake operating force holding means are established until a predetermined time elapses is detected. Whether or not the brake operating force transmission system is frozen can be accurately determined according to the amount of movement, that is, whether or not the brake operating force transmission system is difficult to move due to freezing.

  Incidentally, the electromagnetic brake 33 of the embodiment corresponds to the brake operating force holding means of the present invention, the master cylinder 103 of the embodiment corresponds to the hydraulic power source of the present invention, and performs the functions of steps S7 and S11 in the flowchart of FIG. The means to achieve correspond to the freeze detection means and the freeze release means of the present invention, respectively.

  In the embodiment, the predetermined times T1 and T2 are both set to 0.5 seconds. However, the values can be set as appropriate, and T1 and T2 can be set separately.

  As described above, according to the first aspect of the present invention, when the freezing detection means detects the freezing of the brake operating force transmission system, the freezing release means drives the electric motor to move the brake operating force transmission system in one direction ( Since the brake operating force is increased by driving in the direction in which the wheel brake is operated, the ice freezing the brake operating force transmission system can be crushed to release the freeze.

  According to the second aspect of the present invention, when the disc-type wheel brake that functions as a service brake by hydraulic pressure and functions as a parking brake by the brake operating force transmission system functions as a service brake, Since the transmission system is configured to drive in the other direction (the direction in which the wheel brake operation is released), when the freeze detection means detects that the brake operating force transmission system is frozen, the freeze release means hydraulically applies to the wheel brake. To generate a load in a direction to release the operation of the wheel brake, it is possible to break the ice freezing the brake operating force transmission system and release the freeze.

  According to the invention described in claim 3, when the disc-type wheel brake that functions as a service brake by hydraulic pressure and functions as a parking brake by the brake operating force transmission system functions as a service brake, Since the transmission system is configured to drive in the other direction (direction to release the wheel brake operation), the freeze release means drives the electric motor when the freeze detection means detects that the brake operating force transmission system is frozen. Then, the brake operating force transmission system is driven in one direction (the direction in which the wheel brake is operated) to increase the brake operating force, and hydraulic pressure is supplied to the wheel brake to release the wheel brake operation to the brake operating force transmission system. By generating a load in the direction to be released, the ice that freezes the brake operating force transmission system can be crushed to release the freeze. Kill.

  According to the invention described in claim 4, the movement of the brake operating force transmission system from when the electric motor is stopped and the release of the brake operating force holding means of the brake operating force holding means is established until a predetermined time elapses. Therefore, it is possible to accurately determine whether or not the brake operating force transmission system is frozen depending on the amount of movement, that is, whether or not the brake operating force transmission system is difficult to move due to freezing. it can.

  Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.

  1 to 14 show a first embodiment of the present invention. FIG. 1 is an overall plan view of a vehicle equipped with an electric parking brake device, FIG. 2 is a block diagram of a control system of the electric parking brake device, and FIG. Is a partially broken plan view of the electric parking brake device, FIG. 4 is a sectional view taken along line 4-4 in FIG. 3, FIG. 5 is a sectional view taken along line 5-5 in FIG. 7 is a sectional view taken along the line 7-7 in FIG. 6, FIG. 8 is an operation explanatory diagram corresponding to FIG. 4, FIG. 9 is an operation explanatory diagram corresponding to FIG. 7, and FIG. FIG. 11 is a flowchart of the subroutine of step S7 of the main routine, FIG. 12 is a time chart corresponding to FIG. 11, FIG. 13 is a flowchart of subroutines of steps S11 and S12 of the main routine, and FIG. Corresponding time chart A.

  As shown in FIG. 1, drum-type wheel brakes 11, 11 are provided on the left and right rear wheels Wr, Wr of the vehicle, and an electric parking brake device 12 disposed beside the driver's seat is connected to the left and right Bowden wires 13. , 13 to the wheel brakes 11, 11. Each wheel brake 11 includes a brake drum 14, a pair of brake shoes 15, 16 that can contact the inner peripheral surface of the brake drum 14, a connecting rod 17 that connects both brake shoes 15, 16, and one brake shoe 15. And a lever 19 that is rotatably supported at one end via a pin 18, and the Bowden wire 13 is connected to the other end of the lever 19.

  Accordingly, when the Bowden wire 13 is pulled by the electric motor 30 provided in the electric parking brake device 12, the lever 19 rotates around the pin 18 in the clockwise direction in the figure, and a compression load acts on the connecting rod 17, and the other load is applied by the load. The brake shoe 16 is pushed in the left direction in the drawing to be pressed against the brake drum 14, and one brake shoe 15 is pushed in the right direction in the drawing through the connecting rod 17 and the pin 18 to be pushed against the brake drum 14. The wheel brake 11 generates a braking force. Conversely, when the Bowden wire 13 is loosened by the electric motor 30, the brake shoes 15 and 16 are separated from the brake drum 14 by the elastic force of a return spring (not shown), and the braking force of the wheel brake 11 is released.

  Moreover, since the electric parking brake device 12 is arranged beside the driver's seat, a manual operation operation or an operation release operation by an occupant can be easily performed, and when the electric motor 30 or its control system breaks down, A braking force can be generated in the wheel brake 11 or released by a passenger's manual operation. Furthermore, a sudden bending of the Bowden wires 13 and 13 extending from the electric parking brake device 12 to the wheel brakes 11 and 11 can be prevented to reduce a transmission loss of the brake operating force.

  As shown in FIG. 2, the electric parking brake device ECU 21 that controls the operation of the electric parking brake device 12 includes an interface circuit 22, a main CPU 23, a fail safe CPU 24, an electric motor drive circuit 25, an electromagnetic brake drive circuit 26, and a lamp drive circuit. 27, and the electric parking brake device ECU 21 is powered from the power supply system 28. The interface circuit 22 includes a mode change switch 29a for switching between the auto mode and the manual mode, and an electric parking brake device 12 that is activated or deactivated by a switch operation by an occupant regardless of the switching state of the mode change switch 29a. An operation / release switch 29b, a current sensor 29c for detecting the current flowing through the electric motor 30, a stroke sensor 29d for detecting the position of a nut member 31 to be described later, and detecting the inclination in the front-rear direction of the road surface on which the vehicle is riding An inclination sensor 29e that detects the longitudinal acceleration of the host vehicle, a wheel speed sensor 29g that detects forward and backward wheel speeds, and a master cylinder pressure sensor 29h that detects the master cylinder pressure of the hydraulic brake device. And the brake pedal operation detection And Kisuitchi 29i is connected.

  The interface circuit 22 of the electric parking brake ECU 21 includes an accelerator opening, a shift position, an external ECU 32 such as a fuel injection device, an automatic transmission, an anti-lock brake device, and a VSA system (vehicle stability assist system). Various signals such as an idle stop and a brake control signal are input. The electric motor drive circuit 25 is connected to the electric motor 30, the electromagnetic brake drive circuit 26 is connected to an electromagnetic brake 33, which will be described later, and the lamp drive circuit 27 is a lamp such as a brake warning lamp, an operation lamp, a mode display lamp, and a stop lamp. Connected to class 34.

  Next, the structure of the electric parking brake device 12 will be described with reference to FIGS.

  The housing 41 constituting the main body of the electric parking brake device 12 stands from a horizontally disposed bottom wall 41a, a front standing wall 41b that rises from the front end of the bottom wall 41a, and a vicinity of the rear end of the bottom wall 41a. A rear standing wall 41c is provided, and the front and rear ends of the upper cover 42 are fixed to the upper surface of the front standing wall 41b and the upper surface of the rear standing wall 41c by a plurality of bolts 43, respectively. The electric motor 30 with the output shaft 30a facing backward is fixed to the front surface of the front standing wall 41b of the housing 41 with a plurality of bolts 44.

  A screw shaft 47 is supported on the front standing wall 41b and the rear standing wall 41c via ball bearings 45 and 46, respectively, and the output shaft 30a of the electric motor 30 is connected to the front end of the screw shaft 47. The nut member 31 is engaged with the outer periphery of the screw shaft 47 via a large number of balls 48..., And a ball screw mechanism 49 is constituted by the screw shaft 47, the balls 48, and the nut member 31. A collar 50 is press-fitted into the outer periphery of the nut member 31, and an upper support shaft 51 and a lower support shaft 52 extending in the vertical direction are fixed to the upper surface and the lower surface of the collar 50. A guide roller 53 rotatably supported on the upper end of the upper support shaft 51 is movably fitted in a guide groove 42a formed in the front-rear direction on the lower surface of the upper cover 42 and is prevented from rotating.

  An equalizer 54 having an elliptical cross section disposed so as to surround the outer periphery of the nut member 31 is supported by the upper support shaft 51 and the lower support shaft 52 so as to be swingable in the left-right direction. The Bowden wires 13 and 13 are composed of outer tubes 13a and 13a and inner cables 13b and 13b accommodated in the outer tubes 13a and 13a so as to be relatively movable, and the front ends of the outer tubes 13a and 13a are rear-standing. It is fixed to the rear surface of the wall 41c, and the front ends of the inner cables 13b, 13b pass through the rear standing wall 41c and are fixed to the left and right ends of the equalizer 54.

  Since the amount of movement of the nut member 31 along the screw shaft 47 is proportional to the number of rotations of the screw shaft 47, the stroke sensor 29d that detects the amount of movement of the nut member 31 is used as a rotary encoder that detects the rotation angle of the screw shaft 47, for example. Can be configured.

  The electromagnetic brake 33 includes a core 62 fixed to the rear surface of the front standing wall 41b with four bolts 61, a coil 63 housed in the core 62, and a key 64 on the front portion of the screw shaft 47. A rotor 65 that is fixed and positioned on the rear side of the core 62, and a plate 66 that is supported by the four bolts 61 so as to be movable back and forth and disposed between the rear surface of the rotor 65 and the heads 61a of the bolts 61. An armature 67 is provided between the rear surface of the core 62 and the front surface of the rotor 65 and is supported by the four bolts 61. A first coil spring 68 and a second coil spring 69 are supported on the outer periphery of each of the upper and lower two bolts 61, 61, and the first coil spring 68 disposed between the recess 62 a of the core 62 and the armature 67 is The second coil spring 69 disposed between the armature 67 and the plate 66 urges the armature 67 in a direction in contact with the front surface of the rotor 65, and causes the armature 67 and the plate 66 to move away from the front and rear surfaces of the rotor 65. Energize to. Further, only the first coil spring 68 is supported on the outer periphery of each of the two left and right bolts 61, 61, and the second coil is used to avoid interference with a long hole 71a of the arm portion 71 of the release member 72 described later. The spring 69 is not supported.

  The urging force of the first coil springs 68 is set to be stronger than the urging force of the second coil springs 69. Therefore, when the coils 63 are demagnetized, the urging force of the first coil springs 68. The rotor 65 is sandwiched between the plates 66 and the rotation of the screw shaft 47 is restricted. When the coil 63 is excited, the armature 67 is attracted to the core 62 against the urging force of the first coil springs 68. The armature 67 and the plate 66 are separated from the rotor 65 by the urging force of the second coil springs 69. Thus, the screw shaft 47 is allowed to rotate.

  A release member 72 having a U-shape including a base portion 70 extending in the left-right direction and arm portions 71, 71 extending upward from both ends of the base portion 70 is disposed between the plate 66 and the amateur 67. When the left and right bolts 61, 61 pass through the elongated holes 71a, 71a formed in the left and right arm portions 71, 71 in the vertical direction, the release member 72 is guided so as to be movable in the vertical direction. The Two upper and lower inclined surfaces 71b and 71c are formed on the arm member 71 on the side facing the armature 67 of the release member 72, and two upper and lower inclined surfaces 67a that can contact these inclined surfaces 71b and 71c. , 67b are formed in the amateur 67. When the release member 72 is in the lowered position shown in FIGS. 6 and 7, the inclined surfaces 71b, 71b; 71c, 71c of the release member 72 are separated from the inclined surfaces 67a, 67a; 67b, 67b of the amateur 67.

  The rotary shaft 75 is supported by a plain bearing 73 provided at the rear end of the bottom wall 41a of the housing 41 and a plain bearing 74 provided at the rear end of the rear standing wall 41c of the housing 41 so as to be movable up and down and rotatable. . A coil spring 78 is disposed between a spring seat 77 supported by a lower part of the rotating shaft 75 via a ball bearing 76 and a bottom wall 41a of the housing 41. The coil spring 78 is biased upward by a biasing force of the coil spring 78. The rotating shaft 75 stops at a position where the drive bevel gear 79 fixed to the upper portion of the rotating shaft 75 contacts the lower surface of the plain bearing 74 provided at the rear end of the rear standing wall 41c of the housing 41. A hexagon hole 75a into which a hexagon wrench 80 (see FIG. 8) is inserted is formed at the upper end of the rotating shaft 75 in the axial direction.

  An intermediate portion of the lever 82 is supported by a bracket 41d provided at the center portion of the bottom wall 41a of the housing 41 so as to swing up and down via a pin 81 extending in the left-right direction. A pin 83 extending in the left-right direction is fixed to a bracket 77 a provided on the upper surface of the spring seat 77, and the pin 83 is fitted in a long hole 82 a formed in the rear end of the lever 82 in the front-rear direction. The front end of the lever 82 is fitted in a long hole 70 a formed in the base portion 70 of the release member 72 and extending in the vertical direction.

  A driven bevel gear 84 is fixed to the rear end of the screw shaft 47 that passes rearwardly through the rear standing wall 41c. When the rotary shaft 75 is in a position raised by the biasing force of the coil spring 78, the drive bevel gear 79 of the rotary shaft 75 and the driven bevel gear 84 of the screw shaft 47 are not meshed, but the rotary shaft 75 is in contact with the biasing force of the coil spring 78. When descending against this, the drive bevel gear 79 and the driven bevel gear 84 can mesh with each other.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  When the electric parking brake device 12 is not in operation, the nut member 31 of the ball screw mechanism 49 is in the rear position indicated by the chain line in FIG. 4, and the equalizer 54 supported by the nut member 31 also moves rearward and Bowden wire. 13 and 13 are loosened. At this time, the coil 63 of the electromagnetic brake 33 is not excited, and the screw shaft 47 integral with the rotor 65 is subjected to some external force by sandwiching the rotor 65 between the armature 67 and the plate 66 by the urging force of the first coil springs 68. It is restrained so that it doesn't rotate in delusion. Further, since the rotating shaft 75 is held at the upper first position (see FIG. 4) by the biasing force of the coil spring 78, the meshing of the drive bevel gear 79 and the driven bevel gear 84 is released, and the release member 72 is lowered. In the inoperative position (see FIG. 7).

  When the electric parking brake device ECU 21 or the operation / release switch 29b outputs a command to operate the electric parking brake device 12 from this state, the coil 63 of the electromagnetic brake 33 is first excited and the armature 67 is attracted to the core 62. 67 and the plate 66 are separated from the rotor 65 and the restraint of the screw shaft 47 is released. At the same time, the electric motor 30 is driven, the screw shaft 47 of the ball screw mechanism 49 rotates, and the nut member 31 moves forward from the chain line position in FIG. 4 to the solid line position, and the equalizer 54 moves forward integrally with the nut member 31. A tension is generated in the connected left and right Bowden wires 13 and 13 to operate the left and right wheel brakes 11 and 11. At this time, if the tensions of the left and right Bowden wires 13 and 13 are unbalanced, the equalizer 54 swings in the direction of the arrow AA ′ around the upper support shaft 51 and the lower support shaft 52 in FIG. The same tension is generated in the left and right wheel brakes 11 and 11 by equalizing the tensions 13 and 13.

  As described above, since the driving force of the electric motor 30 is transmitted to the Bowden wires 13 and 13 via the ball screw mechanism 49 capable of reversibly transmitting the driving force, the brake operating force acting on the Bowden wires 13 and 13 ( That is, a reaction force of the tension of the Bowden wires 13 and 13 acts on the electric motor 30 as a load. Therefore, if the relationship between the magnitude of the load of the electric motor 30 and the magnitude of the brake operating force is stored in advance, the magnitude of the load of the electric motor 30 (for example, the current value of the electric motor 30 detected by the current sensor 29c). Therefore, the magnitude of the brake operating force can be controlled to an arbitrary target value.

  Further, since the ball screw mechanism 49 has small frictional force and backlash and good transmission efficiency, even if a small and light electric motor 30 is used, sufficient response can be ensured, and noise during operation is reduced. can do. Furthermore, since the ball screw mechanism 49 is smaller than the reduction gear mechanism, the entire electric parking brake device 12 can be reduced in size.

  When the electric parking brake device 12 is operated in this way and the left and right wheel brakes 11 and 11 generate the necessary braking force, the electric motor 30 is stopped and the coil 63 of the electromagnetic brake 33 is demagnetized, and the first coil spring. The rotation of the screw shaft 47 is restrained by sandwiching the rotor 65 between the armature 67 and the plate 66 by the urging force 68. As a result, even if the tension of the Bowden wires 13 and 13 is reversely transmitted to the screw shaft 47 of the ball screw mechanism 49, the screw shaft 47 is reliably prevented from rotating loosely and the braking force of the wheel brakes 11 and 11 being loosened. can do.

  In addition, when the armature 67 is driven by the electromagnetic brake 33 and the rotation of the screw shaft 47 is controlled by the friction force acting between the plate 66 and the armature 67 and the rotor 65, rotation prevention means such as a ratchet mechanism is used. As compared with the above, the inertial force of the electric motor 30 can be accurately controlled to precisely control the stop position, and the rotor 65 is restrained and released gently through the frictional force, so that the operation noise is reduced. be able to.

  When the electric parking brake device ECU 21 or the operation / release switch 29b outputs a command to release the operation of the electric parking brake device 12, the coil 63 of the electromagnetic brake 33 is first excited to release the restraint of the screw shaft 47. Thus, the left and right wheel brakes 11 are driven by driving the electric motor 30 in the reverse direction to rotate the screw shaft 47 of the ball screw mechanism 49 in the reverse direction and retracting the nut member 31 from the solid line position in FIG. , 11 can be released.

  When the electric parking brake device 12 is activated and the wheel brakes 11 and 11 generate braking force, if the electric motor 30 or its control system fails, the electric parking brake device 12 cannot be released by the electric motor 30. Therefore, it is necessary to cancel the operation by manual operation of the occupant. Therefore, as shown in FIG. 8, when a hexagon wrench 80 is inserted into the hexagonal hole 75 a of the rotating shaft 75 and the rotating shaft 75 is pushed down to the second position against the urging force of the coil spring 78, The drive bevel gear 79 meshes with the driven bevel gear 84 of the screw shaft 47.

  In conjunction with this, the rear end of the lever 82 whose intermediate portion is supported by the pin 81 is pushed down and the front end is pushed up, so that the release member 72 connected to the front end rises between the plate 66 and the armature 67. As a result, as shown in FIG. 9, since the inclined surfaces 71b, 71b; 71c, 71c provided on the release member 72 ride on the inclined surfaces 67a, 67a; 67b, 67b provided on the amateur 67, the plate 66 and the amateur 67 are The electromagnetic brake 33 is released manually without exciting the coil 63 away from the rotor 65 against the urging force of the first coil springs 68.

  Accordingly, by operating the hexagon wrench 80 to rotate the rotating shaft 75 from this state, the screw shaft 47 is rotated via the drive bevel gear 79 and the driven bevel gear 84 that are engaged with each other, and the nut member 31 is moved to the position indicated by the solid line in FIG. Can be moved to the chain line position, whereby the Bowden wires 13, 13 can be loosened and the operation of the wheel brakes 11, 11 can be released.

  Of course, when the operation of the electric parking brake device 12 by the electric motor 30 becomes impossible due to failure, the electric parking brake device 12 can be operated by manual operation using the hexagon wrench 80 as described above. It is. In this case, the nut member 31 is moved from the chain line position of FIG. 8 to the solid line position by rotating the hexagon wrench 80 in the direction opposite to that described above.

  As described above, when the electric motor 30 or its control system fails, the electric parking brake device 12 can be manually operated simply by inserting the hexagon wrench 80 into the hexagon hole 75a of the rotary shaft 75 and rotating it while pushing down. It is possible to operate or cancel the operation, and the convenience is greatly improved.

  Next, the operation of freezing detection and freezing release of the electric parking brake device 12 will be described with reference to a flowchart.

  In the flowchart of FIG. 10, first, in step S1, the outputs of the sensors 29c to 29h are compared with the upper limit value and the lower limit value, and the state of the sensors 29c to 29h depends on whether the output is between the upper limit value and the lower limit value. And the state of the electric motor 30 is checked based on whether or not the electric motor 30 is normally operated by passing a minute current. If the sensors 29c to 29h and the electric motor 30 are normal in the following step S2 and the auto mode is selected by the mode changeover switch 29a in step S4, the electric parking brake device 12 is activated and deactivated in step S5. Is executed based on a command from the main CPU 23 of the electric parking brake ECU 21. If the manual mode is selected by the mode change switch 29a in the step S4, the main CPU 23 command that outputs the operation and release of the electric parking brake device 12 according to the operation of the operation / release switch 29b by the occupant. The manual mode is executed based on the above.

  Even if the auto mode is selected, when the operation / release switch 29b is operated by the occupant, the operation of the operation / release switch 29b has priority over the auto mode and is based on the operation of the operation / release switch 29b. Thus, the electric parking brake device 12 is operated and released.

  In the following step S6, when the electric parking brake device 12 is in an operating state and the main CPU 23 outputs an operation release signal for the electric parking brake device 12 (or when an operation release signal is output from the operation / release switch 29b). In step S7, the electromagnetic brake 33 and the electric motor 30 are controlled to release the operation of the electric parking brake device 12. At this time, freezing detection of the brake operating force transmission system of the electric parking brake device 12 described later is also executed. If the brake operating force transmission system is frozen in step S8 and the freezing flag is set to “1”, the process proceeds to step S11. If no operation release signal is output from the main CPU 23 or the operation / release switch 29b in step S6 and an operation signal is output from the main CPU 23 or the operation / release switch 29b in step S9, the electromagnetic brake is output in step S10. 33 and the electric motor 30 are controlled to operate the electric parking brake device 12.

  In step S6 and step S9, the main CPU 23 of the electric parking brake ECU 21 detects the road surface inclination detected by the inclination sensor 29e, the longitudinal acceleration detected by the longitudinal acceleration sensor 29f, the wheel speed detected by the wheel speed sensor 29g, and the master. Based on the master cylinder pressure of the hydraulic brake device detected by the cylinder pressure sensor 29h, the operation state of the brake pedal detected by the brake switch 29i, the accelerator opening, shift position, idle stop, brake control signal, etc. input from the external ECU It is determined whether or not the electric parking brake device 12 is activated.

  If the freezing flag is set to “1” in step S8, after the brake operating force transmission system is released from freezing in step S11, the result of freezing release is determined in step S12, and the determination result in step S13. If this is not possible, a standby operation is performed in step S14 in order to release natural freezing due to the heat of the muffler.

  Next, details of step S7 (freezing detection) in the flowchart of FIG. 10 will be described based on the flowchart of FIG. 11 and the time chart of FIG.

  First, in step S21, the initial position of the nut member 31 of the electric parking brake device 12 is detected by the stroke sensor 29d. When the electromagnetic brake 33 is released in the subsequent step S22, the nut member 31 pulled by the inner cables 13b, 13b of the Bowden wires 13, 13 urged by the return spring tries to return toward the return position. In the subsequent step S23, when a predetermined time T1 (for example, 0.5 seconds) has elapsed since the electromagnetic brake 33 was released, the current position of the nut member 31 is detected again by the stroke sensor 29d. If the current position of the nut member 31 is larger than the previous return position + return position tolerance α in step S24, the deviation between the initial position and the current position of the nut member 31 is compared with a preset threshold value in step S25.

  At this time, if the nut member 31, the Bowden wires 13 and 13, the levers 19 and 19 of the wheel brakes 11 and 11, and the brake operating force transmission system such as the return spring are not frozen, the nut member 31 is not elastic of the return spring. Since the power is returned to the return position, the answer to step S25 is YES, the process proceeds to step S26, the freezing flag is reset to “0”, and the electric motor 30 is reversed in step S27 to perform the electric parking brake. The operation of the device 12 is released. On the other hand, if the brake operating force transmission system is frozen, the nut member 31 is not easily returned to the return position by the resilient force of the return spring, so the answer to step S25 is NO, and the process proceeds to step S28. The freeze flag is set to “1”.

  Next, details of steps S11 and S12 (freezing release operation and result determination) of the flowchart of FIG. 10 will be described based on the flowchart of FIG. 13 and the time chart of FIG.

  First, in step S31, the brake warning lamp blinks to indicate that the freeze is being released, and in step S32, the electric motor 30 is rotated forward to drive the nut member 31 in the brake operating direction and increase the Bowden wires 13, 13. Pull and break the ice attached to the brake operating force transmission system to release the freeze. The torque generated by the electric motor 30 at this time corresponds to a braking force that does not allow the vehicle to move due to gravity even on a road surface with a 30% gradient, for example. Incidentally, the torque generated by the electric motor 30 at the time of normal parking brake corresponds to a braking force that does not allow the vehicle to move due to gravity even on a road surface with a 15% gradient, for example.

  When the additional pulling is completed, the initial position of the nut member 31 is detected by the stroke sensor 29d in step S33, and when a predetermined time T2 (for example, 0.5 seconds) has elapsed from the detection of the initial position in the subsequent step S34. The current position of the nut member 31 is detected again by the stroke sensor 29d. In a subsequent step S35, the deviation between the initial position of the nut member 31 and the current position is compared with a preset threshold value. If the nut member 31 is returned to the return position by the spring force of the return spring and the answer to step S35 is YES, it is determined that the freezing has been released and the freezing flag is reset to “0” in step S36. If the freeze release performed in step S32 is unsuccessful and the answer to step S35 is NO, the freeze flag is set to “2” indicating unsuccessful freeze release in step S37. Regardless of the success or failure of the freeze release, the electric motor 30 is reversed in step S38.

  Therefore, if the freeze release is successful, the nut member 31 is returned to the return position by the reverse rotation of the electric motor 30, and the operation of the electric parking brake device 12 is released. If the freeze release is not successful, the nut member 31 is returned to the return position. Since the brake operating force transmission system does not return to the inoperative position even if it is returned to, the brake operating force transmission system returns to the inoperative position by natural thawing by a heat source such as a muffler arranged in the vicinity of the rear wheels Wr, Wr. Wait for the vehicle to start. In this case, the brake warning lamp is switched from blinking to lighting to inform the driver that the freeze release has not been completed.

  According to the first embodiment described above, the electric parking brake device 12 is increased and pulled to drive the brake operating force transmission system in one direction, so that the ice freezing the brake operating force transmission system is crushed and released from freezing. Can be carried out effectively. Moreover, by measuring the return amount of the nut member 30 from when the electromagnetic brake 33 of the electric parking brake device 12 is released until the predetermined time T1 elapses, the presence or absence of freezing of the brake operating force transmission system is reliably detected. Can do.

  FIGS. 15 to 20 show a second embodiment of the present invention, FIG. 15 is a diagram showing the configuration of a vehicle brake system, FIG. 16 is a front view of a disc brake device having a parking brake function, and FIG. 16 is a view taken in the direction of arrow 17 in FIG. 16, FIG. 18 is a sectional view taken along line 18-18 in FIG. 16, FIG. 19 is a flowchart corresponding to FIG.

  As shown in FIG. 15, the vehicle of the second embodiment is equipped with a VSA system (vehicle stability assist system) that applies different braking forces to the left and right wheels to stabilize the vehicle behavior. The brake pedal 101 operated by the motor is connected to the master cylinder 103 via an electronically controlled negative pressure booster 102. The negative pressure booster 102 mechanically boosts the pedaling force of the brake pedal 101 to brake the master cylinder 103. In addition to generating hydraulic pressure, the brake pressure signal is actuated by the external ECU 32 (see FIG. 3) to generate the brake hydraulic pressure in the master cylinder 103 regardless of the operation of the brake pedal 101 during automatic braking by the VSA system.

  A pair of output ports 104, 105 of the master cylinder 103 are connected to wheel brakes 107, 107, 108, 108 provided on the front wheels and the rear wheels via a hydraulic control device 106, respectively. The wheel brakes 107, 107, 108, 108 are constituted by disc brakes, of which the rear wheel brakes 108, 108 have a parking brake function in addition to a service brake function. The hydraulic control device 106 includes four pressure regulators 109 corresponding to the four wheel brakes 107, 107, 108, 108, and each pressure regulator 109 is connected to an external ECU 32 to be connected to the front wheels and The operation of wheel brakes 107, 107, 108, 108 provided on the rear wheels is individually controlled.

  Signals from the steering angle sensor Sa, the wheel speed sensor Sb, and the yaw rate sensor Sc are input to the external ECU 32, and are transmitted to the wheel brakes 107, 107, 108, 108 by the pressure regulator 109 based on these signals. By independently controlling the brake hydraulic pressure, the vehicle behavior can be controlled by generating a yaw moment based on the difference in braking force between the left and right wheels. Furthermore, an electric parking brake device ECU 21 (see FIG. 3) is connected to the external ECU 32, and when the freezing occurs, the rear wheel brakes 108, 108 are operated by a command from the electric parking brake device ECU 21 to release the freeze. It is like that.

  Next, the structure of the wheel brake 108 of the rear wheel W provided with a parking brake function will be described with reference to FIGS.

  A brake caliper 111 in which the action portion 111a and the reaction portion 111b are coupled by a bridge portion 111c is supported by a bracket 112 fixed to the vehicle body so as to be slidable in the axial direction of the brake disc 114 via slide pins 113, 113. A pair of friction pads 115, 116 composed of 115 a, 116 a and back plates 115 b, 116 b are disposed on both side surfaces of the brake disc 114. The first friction pad 115 opposes the lining 115a so as to come into contact with one side surface of the brake disc 114 in a state where the back plate 115b is in contact with a brake piston 118 slidably fitted to a cylinder 117 formed in the action portion 111a. The second friction pad 116 faces the other side surface of the brake disc 114 so that the lining 116a can come into contact with the back plate 116b in contact with the reaction portion 111b. An oil chamber 119 formed inside the cylinder 117 communicates with the corresponding pressure regulator 109 (see FIG. 15) via the oil passage 120.

  Accordingly, when the brake hydraulic pressure is supplied from the pressure regulator 109 to the oil chamber 119 via the oil passage 120, the brake piston 118 moves forward in the cylinder 117 by the brake hydraulic pressure, and the lining 115a of the first friction pad 115 is moved to the brake disk 114. Press against one side. As a result, the brake caliper 111 slides along the slide pins 113 and 113 by the reaction force received by the brake piston 118 from the first friction pad 115, and the reaction portion 111 b of the brake caliper 111 brakes the lining 116 a of the second friction pad 116. Press against the other side of the disk 114. Thus, the braking force can be generated by sandwiching both side surfaces of the brake disc 114 with the first and second friction pads 115 and 116 with equal pressure.

  A cam shaft 121 extending in a direction orthogonal to the axis of the cylinder 117 is rotatably supported via a needle bearing 122 at the outer end of the action portion 111 a of the brake caliper 111. A sleeve piston 123 is slidably fitted in the axial direction at the bottom of the cylinder 117 close to the camshaft 121 and is prevented from rotating by a positioning pin 124. The cam surface 121a formed on the camshaft 121 and the back of the sleeve piston 123 Are connected by a push rod 125. Between the sleeve piston 123 and the brake piston 118, an expandable / contractible brake clearance adjusting means including an adjusting bolt 126 and an adjusting nut 127 is disposed.

  A lever 128 and a nut 129 are fixed to the tip end of the camshaft 121 protruding outward from the action part 111a of the brake caliper 111. One end of the return spring 130 wound around the outer periphery of the camshaft 121 is locked to the locking groove 128a of the lever 128, and the other end is locked to the pin 131 fixed to the action portion 111a. The inner cable 13b of the Bowden wire 13 connected to the electric parking brake device 12 is connected to the tip of the lever 128, and this inner cable 13b is a guide of a cable guide 133 fixed to the support portion 111d of the brake caliper 111 with bolts 132 and 132. It is guided to the hole 133a.

  Accordingly, when the inner cable 13b of the Bowden wire 13 is pulled so that the wheel brake 108 performs the parking brake function, the camshaft 121 rotates in the direction of arrow A in FIG. When the cam surface 121a pushes the brake piston 118 via the push rod 125, the sleeve piston 123, the adjustment bolt 126 and the adjustment nut 127, the first and second friction pads 115 and 116 are pressed against the brake disc 114, and braking force is applied. Can be generated.

  Next, details of the freeze release operation and result determination according to the second embodiment will be described based on the flowchart of FIG. 19 and the time chart of FIG.

  As is clear from a comparison between the flowchart of FIG. 13 and the flowchart of FIG. 19, the flowchart of FIG. 19 showing the second embodiment is different from the flowchart of FIG. 19 in that a new step S33a is added between steps S33 and S34. It is different from the flowchart of FIG. 13 showing the embodiment, and the other points are the same.

  First, in step S31, the brake warning lamp blinks to indicate that the freeze is being released, and in step S32, the electric motor 30 is rotated forward to drive the nut member 31 in the brake operating direction and increase the Bowden wires 13, 13. By pulling and driving the lever 128 in the direction of arrow A in FIG. 18, the ice adhering to the brake operating force transmission system is crushed to release the freeze. At this time, the torque generated by the electric motor 30 is the same as in the first embodiment. When the additional pulling is completed, the initial position of the nut member 31 is detected by the stroke sensor 29d in a subsequent step S33.

  In the subsequent step S33a, the negative pressure booster 102 is automatically actuated by a command from the external ECU 32, and is applied to the wheel brakes 108, 108 of the rear wheels via the two pressure regulators 109, 109 of the hydraulic control device 106, for example, 100 Supply brake hydraulic pressure at atmospheric pressure for about 1 second. When the brake hydraulic pressure is applied to the oil chamber 119 of the wheel brake 108, the brake piston 118 is driven toward the brake disc 114. At the same time, the sleeve piston 123 facing the oil chamber 119 moves away from the brake piston 118. Driven. As a result, the lever 128 is driven in the direction of arrow B in FIG. 18 via the push rod 125 and the cam shaft 121, and the ice adhering to the brake operating force transmission system can be crushed to release the freezing.

  In subsequent step S34, when a predetermined time T2 (for example, 0.5 seconds) has elapsed since the detection of the initial position, the current position of the nut member 31 is detected again by the stroke sensor 29d. In a subsequent step S35, the deviation between the initial position of the nut member 31 and the current position is compared with a preset threshold value. If the nut member 31 is returned to the return position by the resilient force of the return spring 130 and the answer to step S35 is YES, it is determined that the freezing has been released, and the freezing flag is reset to “0” in step S36. If the freeze release performed in steps S32 and S33a is unsuccessful and the answer to step S35 is NO, the freeze flag is set to “2” indicating the failure of freeze release in step S37. Regardless of the success or failure of the freeze release, the electric motor 30 is reversed in step S38.

  Therefore, if the freeze release is successful, the nut member 31 is returned to the return position by the reverse rotation of the electric motor 30, and the operation of the electric parking brake device 12 is released. If the freeze release is not successful, the nut member 31 is returned to the return position. Since the brake operating force transmission system does not return to the non-operating position even after returning to, the vehicle is started after the brake operating force transmission system returns to the non-operating position due to natural thawing. In this case, the brake warning lamp is switched from blinking to lighting to inform the driver that the freeze release has not been completed.

  According to the second embodiment described above, first, the electric parking brake device 12 is increased and pulled to drive the brake operating force transmission system in one direction, and then the brake hydraulic pressure is supplied to the wheel brakes 108 and 108 to generate the brake operating force. Since the transmission system is driven in the other direction, the ice freezing the brake operating force transmission system can be reliably crushed and freeze release can be performed more effectively.

  As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.

  For example, the brake operating force transmission system in the first embodiment includes a nut member 31, a Bowden wire 13, a lever 19, a return spring (not shown) and the like, and the brake operating force transmission system in the second embodiment includes the nut member 31. , The Bowden wire 13, the lever 128, the return spring 130, the camshaft 121, etc., the brake operating force transmission system uses the driving force of the nut member 31 of the electric parking brake device 12 as the wheel brake 11, 11, 108, 108. Any device including various members such as a rod, a link, and an arm may be used as long as it can transmit to the frame.

  In the second embodiment, the master cylinder 103 connected to the negative pressure booster 102 that is electronically controlled is illustrated as the hydraulic pressure source of the disc brake type wheel brakes 108, 108. However, other hydraulic pressure such as a hydraulic pump that is electronically controlled is illustrated. Sources can be employed.

  In the second embodiment shown in FIG. 19, the normal brake pressurizing operation (step S33a) is performed after the extra pulling operation (step S32). However, the order may be reversed, and the time for executing both operations May overlap temporarily.

Overall plan view of a vehicle equipped with an electric parking brake device Block diagram of control system for electric parking brake device Partially cutaway plan view of an electric parking brake device Sectional view taken along line 4-4 in FIG. Sectional view along line 5-5 in FIG. 6-6 sectional view of FIG. Sectional view along line 7-7 in FIG. Action explanatory diagram corresponding to FIG. Action explanation diagram corresponding to FIG. Main routine flowchart explaining the operation of the electric parking brake device Flowchart of the subroutine of step S7 of the main routine Time chart corresponding to FIG. Flowchart of the subroutine of steps S11 and S12 of the main routine Time chart corresponding to FIG. The figure which shows the structure of the brake system of the vehicle which concerns on 2nd Example of this invention. Front view of disc brake device with parking brake function 17 direction arrow view of FIG. 18-18 sectional view of FIG. Flowchart corresponding to FIG. Time chart corresponding to FIG.

Explanation of symbols

11 Wheel brake 30 Electric motor 33 Electromagnetic brake (brake operating force holding means)
103 Hydraulic source (master cylinder)
108 Wheel brake S7 Freezing detection means S11 Freezing release means T1 Predetermined time T2 Predetermined time

Claims (4)

In the electric parking brake device for operating the wheel brakes (11, 108) by driving the brake operating force transmission system in one direction by the brake operating force generated by the electric motor (30),
Freezing detection means (S7) for detecting freezing of the brake operating force transmission system;
A freeze release means (S11) for driving the electric motor (30) to increase the brake actuation force in the one direction when the freeze detection means (S7) detects the freezing of the brake actuation force transmission system;
An anti-freezing device for an electric parking brake device, comprising: An electric parking brake device that operates a disc-type wheel brake (108) by driving a brake operating force transmission system in one direction with a brake operating force generated by an electric motor (30),
The wheel brake (108) functions as a service brake by the hydraulic pressure supplied from the hydraulic pressure source (103), and functions as a parking brake by the brake operating force transmitted by the brake operating force transmission system. When driving the brake operating force transmission system in the other direction when functioning as
Freezing detection means (S7) for detecting freezing of the brake operating force transmission system;
Freezing release means (S11) for supplying hydraulic pressure to the wheel brake (108) to drive the brake operating force transmission system in the other direction when the freezing detection means (S7) detects freezing of the brake operating force transmission system;
An anti-freezing device for an electric parking brake device, comprising: An electric parking brake device that operates a disc-type wheel brake (108) by driving a brake operating force transmission system in one direction with a brake operating force generated by an electric motor (30),
The wheel brake (108) functions as a service brake by the hydraulic pressure supplied from the hydraulic pressure source (103), and functions as a parking brake by the brake operating force transmitted by the brake operating force transmission system. When driving the brake operating force transmission system in the other direction when functioning as
Freezing detection means (S7) for detecting freezing of the brake operating force transmission system;
When the freezing detection means (S7) detects the freezing of the brake operating force transmission system, the electric motor (30) is driven to increase the brake operating force in the one direction, and hydraulic pressure is applied to the wheel brake (108). A freeze release means (S11) for supplying and driving the brake operating force transmission system in the other direction;
An anti-freezing device for an electric parking brake device, comprising: The brake operating force transmission system is driven in one direction by the brake operating force generated by the electric motor (30) to operate the wheel brakes (11, 108). When the electric motor (30) is stopped, the brake operating force holding means (33 ) In the electric parking brake device that holds the brake operating force,
The brake operating force transmission system from when the drive of the electric motor (30) is stopped and the holding of the brake operating force by the brake operating force holding means (33) is released until a predetermined time (T1, T2) elapses. A freeze detection device in an electric parking brake device, wherein the presence or absence of freezing of the brake operating force transmission system is determined based on a movement amount.

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