JPH0435252Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention provides a brake system for an automobile that mechanically connects a brake pedal and a hydraulic circuit that transmits braking hydraulic pressure to each brake device. The present invention relates to an electromagnetic servo brake system for automobiles that uses electromagnetic force to boost the applied braking oil pressure, and particularly to measures to prevent wheel tires from locking.

(Prior Art) Conventionally, when the brake pedal of a vehicle is depressed, the brake pedal depression force is applied to the master cylinder of the brake device, and an assist force using the engine's intake negative pressure as a boost source is applied. It is widely known that the braking force of a vehicle can be increased by boosting the braking oil pressure of a master cylinder.

In this type of servo brake device, in order to prevent the wheel tires from locking due to an excessive increase in the braking oil pressure, the brake oil pressure of the master cylinder is The anti-skid mechanism is equipped with an anti-skid mechanism that quickly releases the locked state of the wheels by intermittent action of brake hydraulic pressure on the brake system and decreases the braking force pressure when the tires are locked when the pressure has risen to a predetermined value. .

(Problems to be Solved by the Invention) However, in the above-mentioned conventional device, since the structure of the electromagnetic servo brake device is one in which the brake pedal and the hydraulic circuit are mechanically connected, when the tire of the wheel is locked, Intermittent application of braking hydraulic pressure to the brake system is mechanically transmitted to the brake pedal, causing jerking in the brake pedal.
The drawback was that a good operating feeling of the brake pedal could not be obtained.

The present invention was developed in view of the above, and as disclosed in Japanese Patent Application Laid-Open No. 16128/1983,
We focused on the fact that there are some systems that automatically generate braking hydraulic pressure using electromagnetic force to ensure a quick stop of the vehicle, regardless of whether the driver operates the brake pedal, in the event of a vehicle collision.The purpose of this is to Taking this idea further, we installed an electromagnetic servo brake device that uses electromagnetic force to double the braking hydraulic pressure generated in the master cylinder in response to the depression of the brake pedal, and when the wheels are locked, the electromagnetic servo brake device can be used to lock the wheels. By configuring the brake system to continuously vary the boost ratio depending on the condition, the braking force is continuously reduced when the wheels are locked, ensuring a good operating feeling without jerking the brake pedal. be.

(Means for Solving the Problem) In order to achieve the above object, the configuration of the present invention is such that the brake pedal and the hydraulic circuit are mechanically connected as described above, that is, the depression force of the brake pedal is a hydraulic circuit that transmits to the
The present invention is directed to an electromagnetic servo braking device for an automobile, which is provided in the hydraulic circuit and includes a cylinder and a piston for generating braking oil pressure, and the brake pedal and the piston are connected via a connecting member. and a pedal depression force detection sensor that detects the depression force applied to the brake pedal, a braking pressure detection sensor that detects the braking pressure applied to the brake device, and is driven in response to the outputs of the pedal depression force detection sensor and the braking pressure detection sensor, In order to maintain both outputs in a predetermined boosting relationship, there is an electromagnetic boosting means for controlling the brake hydraulic pressure, a tire locking state detecting means for detecting the locked state of the tires, and an electromagnetic boosting means for detecting the locked state of the tires. The power booster is equipped with a controller that reduces the current flow rate to the booster.

(Function) With the above configuration, in the present invention, when the wheel tire locks, the flow rate of current to the electromagnetic booster is reduced accordingly, and the boosted braking pressure of the master cylinder is continuously increased. By lowering the pressure, the lock condition of the tire is quickly released without causing a jerk to the brake pedal.
This ensures the running safety of the vehicle.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, 1 is a brake pedal, and 2 is a master cylinder that is connected to the brake pedal 1 via an operating rod 3 and a push rod 4 to generate braking hydraulic pressure. The brake pedal 1 is slidably inserted into the body 2a and is connected to the brake pedal 1 via the push rod 4 as a connecting member.
The oil chamber 6 is equipped with a piston 5 that is continuous with the brake pedal 1 and is pressed by the brake pedal 1, an oil chamber 6 defined by the piston 5, and a return spring 7 compressed within the oil chamber 6. The upper part communicates with a reservoir tank 9 via a relief port 8 formed in the cylinder body 2a, and
The lower part of the oil chamber 6 is connected to each brake device (not shown) of each of the four wheels via a hydraulic passage 10. Therefore, when the brake pedal 1 is depressed, the operating rod 3 and the push rod 4 are moved forward by the force applied to the brake pedal, and the piston 5 is moved forward, thereby closing the relief port 8 and filling the oil chamber 6 with braking hydraulic pressure. A hydraulic circuit 13 is configured to generate a brake pressure and transmit braking oil pressure corresponding to the brake pedal force to each brake device via the hydraulic circuit 10.

A pedal force detection sensor 11 is provided around the operator rod 3, which is a load sensor that detects the force applied to the brake pedal 1 when the brake pedal 1 is depressed. Further, in the middle of the hydraulic circuit 10 to each brake device, there is a brake oil pressure detection sensor 12 that detects the brake oil pressure acting on each brake device from the oil chamber 6 of the master cylinder 2.
is provided.

Further, reference numeral 15 is an electromagnetic multiplier that receives both the outputs of the pedal force detection sensor 11 and the brake oil pressure detection sensor 12, and is driven to double the brake oil pressure of the master cylinder 2 based on the two outputs to control the brake oil pressure. The electromagnetic booster 15, which is a force means, is integrated into the master cylinder 2, and includes a coil 16a that is excited in response to a control signal output from a control circuit 20, which will be described later. a cylindrical electromagnet 16, and a plunger 17 disposed in the hollow part of the electromagnet 16 and having the push rod 4 of the master cylinder 2 screwed and fixed to the center core thereof.
When the push rod 4 moves forward when the brake pedal 1 is depressed, the electromagnetic stone 16 attracts the plunger 17 and moves it forward, causing the push rod 4 to move further forward, thereby further moving the piston 5. By driving forward, a predetermined boost of braking oil pressure is generated in the oil chamber 6 of the master cylinder 2.

Next, the internal structure of a control circuit 20 for driving and controlling the electromagnetic booster 15 is shown in FIG. That is, the control circuit 20 includes a first amplifier 21 that inverts and amplifies the output signal from the pedal force detection sensor 11, and a second amplifier 22 that amplifies the output signal from the braking pressure detection sensor 12 as it is. ,
A deviation amplifier 2 that amplifies the sum of both signals from the amplifiers 21 and 22, that is, a deviation signal indicating the deviation between the brake pedal depression force and the braking oil pressure of the master cylinder 2.
3, receives a deviation amplified signal from the deviation amplifier 23 as shown in FIG. comparator 25
and a transistor Tr that is turned on in response to a pulse signal as shown in the figure from the comparator 25 and allows energization of the solenoid 16a of the electromagnet 16 of the electromagnetic booster 15. Current flows to the solenoid 16a of the electromagnet 16 by controlling the duty ratio of the pulse signal from the comparator 25 in accordance with the deviation amplification signal from the deviation amplifier 32 indicating the deviation between the brake pedal depression force and the braking oil pressure of the master cylinder 2. By changing the magnitude of the rate, the piston 5 of the master cylinder 2 is driven forward and backward as appropriate to control the increase/decrease of the braking oil pressure of the master cylinder 2, and the braking oil pressure of the master cylinder 2 is boosted to a predetermined amount with respect to the brake pedal depression force. Configured to keep you in a relationship.

Inside the control circuit 20, there is an integrator 27 that integrates a signal from an acceleration sensor 26 that detects the acceleration of the vehicle to obtain a vehicle speed signal, and a tire rotation sensor that detects the rotational speed of each tire of the vehicle. The deviation between the vehicle speed signal from the integrator 27 and the minimum tire rotation speed signal from the D/A converter 29 is It is equipped with a first differential amplifier 30 that operates, and the first differential amplifier 3
The tire lock state detecting means 31 is configured to detect the locked state of the tire of the wheel by outputting a deviation signal (tire lock state signal) having a value other than "0" from 0.

Therefore, a second differential amplifier 32 is interposed between the deviation amplifier 23 and the comparator 25, and the second differential amplifier 32 transmits the deviation amplified signal from the deviation amplifier 23 to the first differential amplifier 30. The tire lock state signal value is subtracted from the tire lock state signal value and outputted to the comparator 25. Therefore, when the wheels are locked, the duty ratio of the pulse signal from the comparator 25 is reduced by an amount corresponding to the tire lock state signal value from the first differential amplifier 32, and the current flow rate to the electromagnetic booster 15 is reduced. The controller 33 is configured to reduce the

Therefore, in the above embodiment, when the vehicle tires are not locked, the first differential amplifier 3
Since the deviation signal from 0 is "0" value, the electromagnetic means 15 is driven according to the deviation between the brake pedal depression force and the braking oil pressure of the master cylinder 2, and the oil chamber 6 of the master cylinder 2 performs braking with a predetermined boost. When at least one of the four tires begins to gradually lock up, the first differential amplifier 3 detects that hydraulic pressure is generated.
0, a relatively small tire lock state signal is output, and the current flow rate to the electromagnetic booster 15 is slightly reduced, so that the master cylinder 2
The brake oil pressure of the vehicle is slightly lowered to ensure maximum vehicle braking force, and the tire lock condition is quickly released. On the other hand, when at least one tire suddenly locks due to a sudden brake pedal operation, etc., a tire lock status signal with a large value is output from the first differential amplifier 30.
Since the flow rate of current to the electromagnetic booster 15 is greatly reduced, the braking oil pressure of the master cylinder 2 is greatly reduced, and the tires are quickly released from the locked state, and as a result, the vehicle The vehicle will come to a stop smoothly and with good driving safety even with a relatively short braking distance.

At this time, the reduction in the flow rate of the current to the electromagnetic booster 15 is controlled linearly by the continuous change of the tire lock state signal from the first differential amplifier 30 in accordance with the tire lock state. Unlike the case where the braking oil pressure is intermittent, the brake pedal 1 does not jerk, and a good operating feeling of the brake pedal 1 can be ensured.

Further, FIG. 4 shows another embodiment of the present invention, and in the above embodiment, when at least one of the four tires is locked, the braking oil pressure is lowered to simultaneously reduce the braking force of the four wheels. Instead, the braking oil pressure to each wheel is controlled to be reduced separately and independently depending on the locked state of each tire. That is, tandem master cylinder 2'
The hydraulic passages 10 and 10' are each divided into two in the middle to form independent oil supply passages 35 to four brake devices (not shown) corresponding to the four wheels. In the middle of the oil supply passage 35, there are four assist cylinders 36 (only one corresponding to one wheel is shown) for independently boosting the braking oil pressure to each brake device.
is provided, and the assist hydraulic pressure from the corresponding electromagnetic boosting means 15 is supplied to the hydraulic boosting chamber 36a of the assist cylinder 36. In addition, a braking pressure detection sensor 1 provided downstream of the assist cylinder 36
2 and the signal from the pedal force detection sensor 11 are input to the corresponding control circuit 20, and the control circuit 20 also includes a tire rotation sensor 2 that detects the rotation speed of the tire of the corresponding wheel.
8 and signals from an acceleration sensor 26 are input.

Therefore, similarly to the above embodiment, it is possible to continuously control the reduction in the current flow rate to the electromagnetic booster 15 to ensure a good operating feeling of the brake pedal without jerking, and It is possible to further improve driving safety by reducing only the braking oil pressure applied to the tires in the locked state.

[Effect of idea]

Therefore, according to the electromagnetic servo brake system for automobiles of the present invention, although the brake pedal and the hydraulic circuit are mechanically connected, when the tire is in a locked state, the boosted braking hydraulic pressure of the master cylinder is transferred to the electromagnetic servo brake system. Since the flow rate of current to the booster is reduced continuously, it is possible to prevent jerky from occurring in the brake pedal, thereby improving the operation feeling of the brake pedal and ensuring vehicle running safety. This is something that can be secured.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is an overall configuration diagram, Fig. 2 is an internal configuration diagram of a control circuit, Fig. 3 is an explanatory diagram showing changes in distribution rate, and Fig. 4 is an illustration of other FIG. 2 is a main part configuration diagram showing an example. 1... Brake pedal, 2, 2'... Master cylinder (cylinder), 4... Push rod (connecting member), 5 piston, 11... Pedal force detection sensor, 12... Braking pressure detection sensor, 13... Oil pressure Circuit, 15... Electromagnetic boosting means, 31... Tire lock state detection means, 33... Controller.

Claims (1)

[Scope of utility model registration request] A hydraulic circuit that transmits the pressing force of the brake pedal to each brake device, and a cylinder and a piston that are installed in the hydraulic circuit and generate braking hydraulic pressure,
The brake pedal and the piston are connected via a connecting member, and include a pedal depression force detection sensor that detects the depression force applied to the brake pedal, a braking pressure detection sensor that detects the braking pressure applied to the brake device, and a brake pressure detection sensor that detects the braking pressure applied to the brake device. An electromagnetic booster that is driven by the outputs of the pedal force detection sensor and the braking pressure detection sensor and controls the brake oil pressure so that both outputs are maintained in a predetermined boost relationship, and a tire lock state detector that detects the locked state of the tires. 1. An electromagnetic servo braking device for an automobile, comprising: means for detecting a tire lock state; and a controller for reducing a current flow rate to the electromagnetic boosting means in response to an output from the tire lock state detecting means.