JPH0522242U - Safety mechanism of vehicle brake control device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] By using a mechanical brake actuating device in combination with an electric brake, the braking device operates even when the braking force is lost due to an electrical failure. [Configuration] The parking cable 9 and the brake pedal 1 are connected by a cable via an electromagnetic clutch 7.
The electromagnetic clutch 7 is electrically connected to the electronic control unit ECU and is normally energized to disconnect the clutch. When abnormal, the electromagnetic clutch 7 is deenergized and the clutch is connected. Has become. Therefore, when the brake actuator 5 stops operating due to an electrical failure, the electromagnetic clutch 7 is connected, the cable connected to the brake pedal 1 and the parking cable are mechanically connected, and the energization of the electromagnetic clutch 7 is stopped. Then, the clutch is engaged and the brake pedal 1 is depressed to brake the rear wheel via the parking cable 9.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a safety mechanism of a vehicle brake control device. More specifically, the invention relates to a safety mechanism of an electric system (a so-called by-wire system braking device) combined with a mechanical system braking device. Even if an electrical failure occurs in the brake system, the mechanical brake system is activated immediately so that the brake system for vehicles can be reliably braked in any situation. It concerns a safety mechanism.

[0002]

[Prior Art]

 Generally, as a vehicle brake control device using a so-called by-wire type brake device that operates a brake by an electric signal, those described in JP-A-62-216852 and JP-A-2-267056 are known. There is. Each of these vehicle brake control devices detects the pedaling force or stroke of the brake pedal with a sensor, and controls the brake actuator with an electric control device according to the output from the sensor, which is provided on the wheel. It is designed to generate a predetermined brake pressure in the wheel cylinder.

[0003]

[Problems to be solved by the device]

 By the way, since the electric vehicle brake control device as described above can easily perform various controls by electric signals, it is particularly easy to adapt to an anti-skid break system or a traction control system. Since its configuration is simpler than that of such mechanical type, its usability may increase in the future. However, these vehicle brake control devices are designed to electrically control all the brake operating force based on a signal from a sensor that detects the pedaling force of the brake pedal or a stroke, that is, Since this is an electric control mechanism that is different from the mechanical brake actuation mechanism that uses hydraulic pressure and mechanical links, the brake will not operate if an electrical failure such as a sensor failure or wire breakage occurs. , There was a big safety issue.

In view of the above, the present invention uses a mechanical brake actuating device in addition to the above-mentioned electric brake actuator, so that the mechanical brake device can be immediately operated even when the braking force is lost due to an electrical failure. It is intended to propose a safety mechanism for a vehicle brake control device that operates so that the brakes can be reliably applied under any circumstances.

[0005]

[Means for Solving the Problems]

 Therefore, the first technical solution of the present invention is for a vehicle having a parking brake device and a brake actuator 5 capable of supplying a predetermined hydraulic pressure to a wheel cylinder provided on a wheel by a signal from an electronic control unit ECU. In the brake control device, the brake pedal 1 and the parking brake device are connected by a cable via an electromagnetic clutch 7, and the electromagnetic clutch 7 is connected only when the brake actuator 5 becomes inoperative. The second technical solution is to drive the brake actuator 5 in response to a signal from the electronic control unit ECU, and the parking brake device is provided on the wheel. A vehicle brake that can supply a predetermined hydraulic pressure to the wheel cylinders. In the brake control device, the brake actuator 5 and the brake pedal are connected by a cable via the electromagnetic clutch 7, and the electromagnetic clutch 7 is connected only when the brake actuator 5 becomes inoperative, and the brake pedal 1 is operated. The brake actuator 5 is mechanically operated by means of which a predetermined hydraulic pressure can be generated in the wheel cylinder. The third technical solution is to drive the brake actuator 5 by a signal from the electronic control unit ECU to drive the wheel. In a vehicle brake control device capable of supplying a predetermined hydraulic pressure to a wheel cylinder provided in, the brake actuator 5 and the parking brake device are connected to a brake pedal by a cable via an electromagnetic clutch 7, respectively. The brake actuator The electromagnetic clutch is connected only when the vehicle is inoperative, and the parking brake device and the brake actuator 5 are operated by operating the brake pedal 1 so that the braking force can be applied to the wheels. , These are the means to solve the problems.

[0006]

[Action]

 [Normal] When the brake pedal 1 is depressed to apply the brakes, the front wheels can be braked by the hydraulic pressure generated in the master cylinder as in the conventional case. When the brake pedal 1 is depressed on the rear wheel, the pedaling force at that time is detected by the pedaling force sensor 2 and input to the electronic control unit ECU. The electronic control unit ECU performs a predetermined calculation based on the signal from the pedal effort sensor 2 and supplies a current proportional to the brake effort to the brake actuator 5. As a result, when the motor 51 is driven, the piston 60 moves leftward in the figure against the biasing force of the spring 66 by the operation of the pinion 53, the gear 54, the screw 58, and the nut 59, and the hydraulic pressure generating chamber 61 Generates a predetermined hydraulic pressure inside. The hydraulic pressure generated in the hydraulic pressure generation chamber 61 is supplied to the wheel cylinders mounted on the wheels to brake the rear wheels.

[Abnormality] In the event that the brake actuator 5 stops operating due to disconnection or battery abnormality in the electric brake device, the electromagnetic clutch 7 is de-energized and the electromagnetic clutch 7 latches. A is engaged with the latch B by the action of the spring 71, and the clutch is in the connected state. As a result, the cable connected to the brake pedal 1 is connected to the parking cable, and by stepping on the brake pedal 1, the rear wheel can be braked via the cable → electromagnetic clutch → parking cable.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram of a safety mechanism of a vehicle brake control device according to a first embodiment of the present invention. In FIG. 1, 1 is a brake pedal, 2 is a pedaling force sensor for the brake pedal 1, 3 is a master cylinder, and this master cylinder 3 is connected to a wheel cylinder of a front wheel by a hydraulic pipe 4. In this embodiment, the brake pedal 1 is used. By stepping on, the front wheels can be braked in the same way as the normal brakes. The wheel cylinder of the rear wheel is connected to a brake actuator 5 having a structure described later by a hydraulic pipe 6, and the brake actuator 5 is electrically electronically operated so as to be operated by a signal from an electronic control unit ECU. It is connected to the control unit ECU. Further, the electronic control unit ECU is electrically connected to the pedaling force sensor 2 so that the brake actuator 5 can be controlled by a signal from the pedaling force sensor 2 to brake the rear wheels. As is well known, the rear wheel is provided with a parking brake, and the parking brake is composed of a parking lever 8, a braking device provided on the wheel, and a parking cable 9 for connecting them, The brake device can be operated by pulling the lever 8.

The parking cable 9 and the brake pedal 1 are connected by a cable via an electromagnetic clutch 7 having a structure described later. The electromagnetic clutch 7 is electrically connected to the electronic control unit ECU and is normally energized to disconnect the clutch. When abnormal, the electromagnetic clutch 7 is deenergized and the clutch is engaged. It is configured to be. Therefore, when the power supply from the ECU is stopped and the electromagnetic clutch 7 is connected due to an electrical failure, the cable connected to the brake pedal 1 and the parking cable are mechanically connected. Therefore, when an electrical defect occurs and the energization of the electromagnetic clutch 7 from the electronic control unit ECU is stopped, the clutch is engaged and the brake pedal 1 is depressed to brake the rear wheel through the parking cable 9. Can be applied.

Next, a detailed structure of the brake actuator 5 according to the present invention will be described with reference to FIG. As shown in FIG. 4, the brake actuator 5 includes a motor 51, a pinion 53 rotated by the motor 51, a gear 54 meshing with the pinion 53, a screw 58 fixed to the gear 54 as a screw member, and a screw. A nut 59 screwed to 58, a piston 60 fixed to the nut 59, a hydraulic pressure generating chamber 61 that generates hydraulic pressure by the movement of the piston 60, a reservoir 62, and a housing 63 that can efficiently store these members. It is composed of The piston 60 is slidably fitted in a cylinder formed in the housing 63, and the nut 59 screwed to the screw 58 is fixed to the piston 60 as described above. The nut 59 has a groove 64 in the same axis direction as the screw shaft, and a rotation stopper 65 is fitted in the groove 64 so that the nut 59 does not rotate even if the screw 58 rotates. There is. Moreover, the piston 60 is normally urged rightward in the drawing by a spring 66. Therefore, when the screw 58 rotates, the nut 59 moves in the cylinder, and the piston 60 can slide in the cylinder.

Therefore, in the brake actuator 5, when the motor 51 is driven by the signal from the electronic control unit ECU, the pinion 53 and the gear 54 rotate, and the screw 58 rotates accordingly. The rotation of the screw 58 is transmitted to the nut 59, and the nut 59 moves on the screw 58 to the left in the figure in the figure while the rotation is restricted by the rotation stop 65. By the movement of the nut 59, the piston 60 integrated with the nut 59 also moves to the left in the figure against the biasing force of the spring 66, and a predetermined hydraulic pressure is generated in the hydraulic pressure generating chamber 61. The hydraulic pressure generated in the hydraulic pressure generation chamber 61 is supplied to the wheel cylinders mounted on the wheels to brake the wheels. When the driving force from the motor 51 disappears, the piston 60 returns to the initial state by the urging force of the spring 66. As described above, this brake actuator adopts the master cylinder type, and when the motor is driven electrically, the wheels can be braked.

By the way, the brake actuator 5 employs a mechanism in which a mechanical brake actuating device immediately operates even if an electrical failure occurs in the electrical brake device. The details of the brake actuation mechanism by the method will be described. In order to mechanically operate the brake actuator, the brake actuator 5 is provided with a clutch 52 facing the gear 54 of the brake actuator as shown in FIG. A known ball ramp mechanism 67, which is also described in No. 18828, is provided. The ball ramp mechanism 67 is connected to the cable via a lever 68 as shown. Therefore, when the lever 68 is pulled in the direction perpendicular to the drawing by the cable, the ball ramp mechanism 67 operates and the clutch 52 is connected. Further, in this state, when the lever 68 rotates, the gear 54 rotates, which causes the screw 58 to rotate and the nut 59 to move, and the brake can be operated in the same manner as described above.

Next, the structure of the electromagnetic clutch 7 that connects the parking brake and the brake pedal will be described. The electromagnetic clutch 7 has latches A and B arranged in a housing 75. The latches A and B are normally disengaged from each other as shown in the drawing. The latch B is arranged so as to be slidable by a predetermined stroke in the housing 75, is connected to the brake pedal 1 via a cable, and a spring 73 is provided between the latch B and the housing 75. The latch B is normally in the position shown in the figure by the biasing force of the spring. Normally, when the brake pedal 1 is stepped on, the latch B is pulled by the cable and moves leftward in the drawing against the spring 73 in the housing. When the brake pedal 1 is released, the latch B is latched by the biasing force of the spring 73. B returns to the position shown. Therefore, the latch B normally does not mesh with the latch A, and the movement of the brake pedal is not restricted by the latch B at all.

On the other hand, the latch A is arranged so as to be slidable by a predetermined stroke in the housing 75, is connected to the parking cable via a cable, and is urged by a spring provided in the housing. Is always in the state shown in the figure. Therefore, similarly to the latch B, the latch A has a structure in which the parking brake operation is not normally restricted. A pressing member 76 is attached to the latch A, and the pressing member 76 is configured so that it can freely move in the lateral direction in the drawing. An electromagnet 74 is arranged opposite to the end of the pressing member 76. When the electromagnet 74 is energized, the pressing member 76 is attracted to release the engagement with the latches A and B. is there. A spring 71 is arranged between the latch A and the housing 75, and the spring 71 urges the latch A downward in the drawing. Therefore, in the electromagnetic clutch 7, when the electromagnet 74 is in the energized state, the pressing member 74 is attracted to the electromagnet, and the latch A is pulled upward in the figure against the biasing force of the spring 71 and engaged with the latch B. Has been removed. However, when the electricity supply to the electromagnet 74 is stopped due to some abnormality, the latch A is engaged with the latch B by the action of the spring 71, and the parking brake can be operated by the brake pedal 1.

Since the first embodiment is configured as described above, it operates as follows. [Normal] When the brake pedal 1 is depressed to apply the brakes, the front wheels can be braked by the hydraulic pressure generated in the master cylinder as in the conventional case. Further, the rear wheel can be braked by the brake pressure from the brake actuator 5 as follows. That is, when the brake pedal 1 is depressed, the pedaling force at that time is detected by the pedaling force sensor 2 and input to the electronic control unit ECU. The electronic control unit ECU performs a predetermined calculation based on the signal from the pedal effort sensor 2 and supplies a current proportional to the brake pedal effort to the brake actuator 5. As a result, when the motor 51 is driven, the piston 60 moves to the left in the figure against the urging force of the spring 66 due to the operation of the pinion 53, the gear 54, the screw 58, and the nut 59, as described above. A predetermined hydraulic pressure is generated in the generation chamber 61. The hydraulic pressure generated in the hydraulic pressure generation chamber 61 is supplied to the wheel cylinders mounted on the wheels to brake the wheels. When the driving force from the motor 51 disappears, the piston 60 returns to the initial state by the urging force of the spring 66. As described above, the brake actuator 50 can generate a braking force by the operation of the motor 50 driven by the signal from the electronic control unit ECU. At this time, since the electromagnetic clutch 7 is energized and the clutch is disengaged, the cable connected to the brake pedal 1 and the parking cable are not connected, and even if the brake pedal 1 is operated, Mechanical brakes do not work on the rear wheels.

[Abnormality] In the event that the brake actuator 5 stops operating due to a disconnection or battery abnormality of the electric brake device, the electromagnetic clutch 7 is de-energized and the electromagnetic clutch 7 latches. A is engaged with the latch B by the action of the spring 71, and the clutch is in the connected state. As a result, the cable connected to the brake pedal 1 is connected to the parking cable, and by stepping on the brake pedal 1, the rear wheel can be braked via the cable → electromagnetic clutch → parking cable. When the brake pedal 1 is released, the springs 72 and 73 in the electromagnetic clutch return the cable to the initial state and the brake is released. If the brake actuator 5 stops operating due to a disconnection or battery abnormality while the brake pedal 1 is being depressed, the electromagnet 74 is immediately de-energized and the spring 71 causes the latch A to engage the latch B. To meet. At this time, the meshing position of the latches A and B is different from the above-mentioned position, but the brake operates in the same manner as above. When the brake pedal 1 is released, the latch A returns to the initial state, and then the latch B returns to the initial state by overcoming the pressing force of the latch A by the spring 73 and overcoming the teeth of the latch A. ..

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, 1 is a brake pedal, 2 is a pedaling force sensor of the brake pedal 1, and a signal from this sensor 2 is input to the electronic control unit ECU. Further, the wheel cylinder of the wheel is connected to the brake actuator 5 having the above-described structure by the hydraulic pipe 6 and the brake actuator 5 is electrically operated to be operated by a signal from the electronic control unit ECU. It is connected to the. As is well known, a parking brake is provided on a rear wheel of the wheels, and the parking brake is composed of a parking lever 8, a braking device provided on the wheel, and a parking cable 9 connecting them. The rear wheel braking device can be operated by pulling the parking lever 8.

The electronic control unit ECU can control the brake actuator 5 by a signal from the pedaling force sensor 2 to apply a brake to the rear wheel. The parking cable 9 and the brake pedal 1 are connected by a cable via the electromagnetic clutch 7 having the above-mentioned structure. Therefore, also in this embodiment, when the brake actuator 5 stops operating due to an electrical failure, the electromagnetic clutch 7 is connected and the cable connected to the brake pedal 1 and the parking cable are mechanically connected, and the brake pedal 5 is mechanically connected. By stepping on 1, the rear wheel can be braked via the parking cable 9. Further, the lever provided on the front wheel brake actuator 5 (see the description of the structure of the brake actuator) is also connected to the brake pedal via the electromagnetic clutch 7 by a cable, so that the electromagnetic clutch 7 is de-energized and the clutch is closed. When connected, the brake actuator 5 can be operated by the operation of the brake pedal 1. The other operations are similar to those of the first embodiment. Therefore, also in the second embodiment, similarly to the first embodiment, when an electrical failure such as a sensor failure or a wire breakage occurs, the mechanical braking device is activated immediately to cause a brake. it can.

As described above, in the safety mechanism of the vehicle brake control device according to the present invention, when electrical failure such as sensor failure or wire breakage occurs once while the brake control is normally performed by the electric method. Since the brake can be immediately actuated by the mechanical system, it is possible to provide a very safe vehicle braking control device. Further, the brake actuator of the present invention can drive the motor to move the piston arranged in the cylinder to generate a predetermined hydraulic pressure in the hydraulic pressure generating chamber 28 according to a signal from the electronic control unit ECU. As a result, a brake actuator with a simple structure can be obtained. Moreover, since the parking brake that is normally used can be used by using the electromagnetic clutch, the safety mechanism can be configured at low cost.

The mechanism of the brake actuator is not limited to the one described above. For example, a mechanism for operating a piston by using a linear motor or an electrostrictive element described in JP-A-62-216852 is used. Various mechanisms such as a mechanism for activating a piston can be adopted. Further, the mechanical brake system for safety may be adopted not only for all the wheels as in the above embodiment but also for only the rear wheel side or only the front wheel side.

[0021]

[Effect of the device]

 As described above in detail, according to the present invention, even if the brake actuator for a vehicle of an electric system is unable to operate due to an electrical failure, the electromagnetic clutch immediately operates and the brake is mechanically applied. It is possible to obtain excellent effects such as being able to operate and obtaining a safety mechanism of the vehicle brake control device having extremely high safety.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a safety mechanism of a vehicle brake control device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a safety mechanism of a vehicle brake control device according to a second embodiment of the present invention.

FIG. 3 is a structural diagram of an electromagnetic clutch used in an embodiment of the present invention.

FIG. 4 is a structural diagram of a brake actuator used in an embodiment of the present invention.

[Explanation of symbols]

 1 brake pedal 2 tread force sensor 5 brake actuator 6 hydraulic piping 7 electromagnetic clutch 8 parking lever 51 motor 52 clutch 59 screw 60 piston 61 hydraulic pressure generation chamber

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kei Kunimi 5-4-71 Higashi, Hanyu City, Saitama Prefecture, Akebono Brake Central Technical Research Institute Co., Ltd. (72) Masahiro Nezu 5-4-1 East, Hanyu City, Saitama Company Akebono Brake Central Technology Research Institute (72) Inventor Kimio Takahashi 5-471 Higashi, Hanyu City Saitama Prefecture Akebono Brake Central Technology Research Institute (72) Inventor Masatomo Mori 5-471 East Hanyu City, Saitama Prefecture Akebono Brake Central Technology Research Institute Co., Ltd. (72) Inventor Tadashi Kobayashi 5-471 Higashi, Hanyu City, Saitama Prefecture Akebono Brake Central Technology Research Institute Co., Ltd. (72) Eiji Shindo 5-54 East, Hanyu City, Saitama Prefecture Akebono Brake Central Technology Research Institute Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. A brake control device for a vehicle, comprising a parking brake device and a brake actuator 5 capable of supplying a predetermined hydraulic pressure to a wheel cylinder provided on a wheel by a signal from an electronic control device ECU. And the parking brake device are connected by a cable via the electromagnetic clutch 7, and the electromagnetic clutch 7 is connected only when the brake actuator 5 becomes inoperative, and the parking brake device can be operated by operating the brake pedal 1. A safety mechanism of a vehicle brake control device characterized by the above. 2. A brake control device for a vehicle, wherein the brake actuator 5 is driven by a signal from an electronic control unit ECU so that a predetermined hydraulic pressure can be supplied to a wheel cylinder provided on a wheel. Are connected by a cable via the electromagnetic clutch 7, and the electromagnetic clutch 7 is connected only when the brake actuator 5 is inoperative, and the brake actuator 5 is mechanically operated by the operation of the brake pedal 1 to operate the wheel cylinder. A safety mechanism for a vehicle brake control device, characterized in that a predetermined hydraulic pressure can be generated. 3. A vehicle brake control device capable of driving a brake actuator 5 in response to a signal from an electronic control unit ECU to supply a predetermined hydraulic pressure to a wheel cylinder provided on a wheel, the brake actuator 5 and a parking brake. The device is connected to the brake pedal via a cable via the electromagnetic clutch 7, and the electromagnetic clutch is connected only when the brake actuator 5 becomes inoperative. By operating the brake pedal 1, the parking brake device and the brake actuator 5 are connected. A safety mechanism for a vehicle brake control device, characterized in that it is activated to apply a braking force to wheels.