JP3175461B2 - Automatic braking device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic brake device for a vehicle, which is suitable for use in automatic driving of an automobile.

[0002]

2. Description of the Related Art Conventionally, an automatic braking device for a vehicle has been developed which automatically brakes the vehicle, for example, to prevent runaway of the vehicle (generally, an automobile). An important component is a brake actuator (ie, an actuator for automatic braking). Also, in such an automatic brake device,
An automatic brake must be able to be operated without deteriorating the performance of a brake (conventional brake) by a normal driver's operation, and the configuration of a brake actuator is particularly important.

[0003] As such a brake actuator,
For example, an anti-lock brake system (hereinafter referred to as A
It has been considered to use a hydraulic brake actuator used for BS. Further, as such a brake actuator, for example, an electric motor type as shown in FIG. 11 can be considered. This system employs an electric motor type provided in parallel with a hydraulic line 102 for driving a hydraulic piston (not shown) on the caliper 101 side (that is, a conventional hydraulic line for supplying a hydraulic pressure corresponding to a brake operation). A hydraulic supply / discharge line 103 and a switching valve (OR valve) 104 which can select any one of the conventional hydraulic line 102 and the electric motor type hydraulic supply / discharge line 103 and introduce it to the caliper 101 side. Become.

An electric motor type hydraulic supply / discharge line 103 includes an electric motor 105, the electric motor 105 and the gear mechanism 1.
Ball screw type piston mechanism 10 connected via
6, a ball screw type piston mechanism 106 connected to a gear mechanism 107, a piston 109 which is screwed with the ball screw 108, moves forward and backward by receiving the rotation of the ball screw 108, and expands and contracts by moving the piston 109 forward and backward. And an oil chamber 110.

When the switching valve 104 opens the electric motor type hydraulic supply / discharge line 103, the rotation of the electric motor 105 is transmitted to the ball screw 10 via the gear mechanism 107.
8 to drive the piston 109 forward,
The oil chamber 110 is reduced, and a hydraulic piston (not shown) on the caliper 101 side is driven to generate a braking force.

Further, Japanese Patent Application Laid-Open Nos. Hei 4-262957, Hei 4-303060, Hei 4-310460
Japanese Patent Laid-Open Publication No. Hei 4-339066 discloses a proposal in which a negative pressure type brake booster (that is, a vacuum booster) is applied to a brake actuator for automatic braking. An example of application of these brake boosters to automatic braking is to directly control the pressure balance between the negative pressure chamber and the atmospheric pressure chamber, which is unique to the brake booster, to adjust the brake fluid pressure for driving the hydraulic piston on the caliper side It is something to do.

[0007]

However, in the above-described automatic brake device using the hydraulic brake actuator used in the ABS, during automatic braking, the hydraulic pressure of the brake is controlled by the actuator regardless of the amount of depression of the brake pedal. Therefore, even if the brake pedal is depressed when the actuator fails, the brake pressure may not be increased and braking may not be performed.

Further, in the conventional automatic brake device using the hydraulic brake booster, since the hydraulic pressure of the brake is directly controlled, the brake feeling becomes unnatural or the hydraulic pressure is generated by a pump of a hydraulic power source. There is a problem that noise is likely to increase. In the above-described electric motor type automatic brake device, the switching valve (OR valve) 1
Since a countermeasure for failure 04 is required, and friction occurs in the ball screw type piston mechanism 106, it is difficult to enhance control responsiveness, and it is difficult to obtain sufficient control performance as an automatic brake. In addition, since assist such as a vacuum booster cannot be used for automatic braking, it is necessary to increase the output of the electric motor, resulting in an increase in the size, weight, energy consumption, and cost of the device.

In the automatic brake device using the above-described vacuum booster, it is easy to cope with a failure, but the control pressure for adjusting the brake fluid pressure is given by the air pressure which is a compressible fluid. There is a problem that the maximum control pressure cannot be increased, the maximum pressure increase speed of the brake fluid pressure cannot be increased, and sudden braking cannot be performed. The present invention has been made in view of such a problem, and enables a driver to obtain a normal braking force by operating a brake pedal even when an automatic braking system fails, and has a high responsiveness and high control performance. It is an object of the present invention to provide an automatic braking device for a vehicle, which can perform automatic braking by using the automatic braking device.

[0010]

According to a first aspect of the present invention, there is provided an automatic brake device for a vehicle according to the present invention, wherein a brake pedal interlocking member which moves forward and backward in conjunction with a brake pedal to operate a master cylinder, and a brake pedal interlocking member. A diaphragm connected to the member, a negative pressure chamber and an atmospheric pressure chamber partitioned by the diaphragm, and interlocking with the brake pedal interlocking member for assisting the depressing force of the brake pedal when depressing the brake pedal. A vacuum booster mechanism comprising an on-off valve for generating a pressure difference between the negative pressure chamber and the atmospheric pressure chamber is provided, and the brake pedal interlocking member is operated even when the brake pedal is not depressed. An actuator for automatic braking that can be driven to the side to operate the master cylinder; The brake pedal interlocking member so that the brake pedal interlocking member can press the brake pedal interlocking member toward the brake operation side, but does not prevent the brake pedal interlocking member from advancing to the brake operation side by depressing the brake pedal. A piston installed to be able to contact the
A hydraulic chamber that can apply hydraulic pressure to the piston to drive the brake to the brake operation side, a hydraulic adjustment mechanism that adjusts the hydraulic pressure in the hydraulic chamber, and a return spring that biases the piston in a direction opposite to the brake operation side And the brake pedal interlocking member is a main body of the vacuum booster mechanism.
Is a shaft-shaped member that extends through the center of the
The brake operation is provided on the outer periphery of the brake pedal interlocking member.
A pressure receiving surface that receives a pressing force toward the working side is formed, and
Abuts against the pressure receiving surface and pushes the
It is characterized in that a pressing surface for applying pressure is formed .

According to a second aspect of the present invention, there is provided an automatic brake device for a vehicle according to the first aspect, wherein
An adjustment mechanism is provided between the hydraulic source and the hydraulic chamber.
And an oil passage provided in the middle of the oil passage,
And a feed mode for feeding hydraulic oil from
A switching valve having a stop mode for stopping, and the switching valve
A pressure control valve for controlling the hydraulic pressure of the hydraulic oil fed through
It is characterized by being comprised from .

According to a third aspect of the present invention, there is provided an automatic braking device for a vehicle according to the first or second aspect.
The hydraulic pressure source and a part of the oil passage of the hydraulic pressure adjusting mechanism are
At least one of a four-wheel steering device and an automatic steering device for a vehicle.
It is characterized in that it is used together with one .

[0013]

[0014]

[0015]

In the above-mentioned automatic brake device for a vehicle according to the present invention, in the automatic brake actuator, the piston can be driven to the brake operation side by applying hydraulic pressure to the hydraulic chamber through the hydraulic adjustment mechanism. When the piston moves to the brake operation side, the brake pedal interlocking member is driven to the brake operation side even if the brake pedal is not depressed, so that the master cylinder is operated to the side where the braking force is generated. Thereby, a brake can be automatically given.

Also, at this time, in the vacuum booster mechanism, the on-off valve generates a pressure difference between the negative pressure chamber and the atmospheric pressure chamber in conjunction with the brake pedal interlocking member, so that the brake operation of the brake pedal interlocking member is performed. The driving to the side is assisted by this vacuum booster mechanism, so that the automatic braking can be provided more quickly. Further, since the piston is installed so as not to hinder the advancement of the brake pedal interlocking member toward the brake operation side by depressing the brake pedal, if the driver wants to apply a brake to the vehicle, the driver depresses the brake pedal. By moving the brake pedal interlocking member to the brake operation side and utilizing the assist provided by the vacuum booster, the master cylinder can be operated to the side where a braking force is generated to apply a brake to the vehicle.

[0017] Then, during operation of the piston, when the piston is driven to the brake operating side, pressing surface formed on the piston, abuts against the pressure receiving surface formed on the outer periphery of the brake pedal interlock member Apply pressing force to the brake operation side. As a result, the brake pedal interlocking member is driven to the brake operation side, so that the master cylinder is operated to the side where a braking force is generated, and automatic braking is applied.

On the other hand, since the pressing surface of the piston comes into contact with the pressure receiving surface of the brake pedal interlocking member but is not particularly connected thereto, the pressure receiving surface can be freely separated from the pressing surface, whereby the piston can be moved. A state is achieved in which the brake pedal interlocking member does not prevent the brake pedal interlocking member from advancing toward the brake operation side by depressing the brake pedal .

According to the second aspect of the present invention, there is provided an automatic vehicle for a vehicle.
In the brake device , the switching valve is set to one of a feed mode and a stop mode in the hydraulic pressure adjusting mechanism. When the feed valve is set to the feed mode, the hydraulic oil from the hydraulic source is passed through the oil passage. The hydraulic pressure can be supplied to the hydraulic chamber , and the hydraulic pressure of the hydraulic chamber is adjusted while controlling the hydraulic pressure of the hydraulic oil supplied through the switching valve by the pressure control valve. Further, when the switching valve is set to the stop mode, the oil from the hydraulic source
The supply of the hydraulic oil to the pressure chamber is stopped.

According to the third aspect of the present invention, there is provided an automatic vehicle according to the present invention.
In the brake device, the configuration of the hydraulic system is simplified .

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional view of a vacuum booster showing an essential part of an automatic brake actuator according to an embodiment of the present invention. 2 is a schematic configuration diagram showing a hydraulic pressure adjusting mechanism of the automatic brake actuator, and FIG. 3 is a sectional view showing the vacuum boosting mechanism.

As shown in FIG. 2, the present vehicle automatic brake device is attached to a brake device having a master back (vacuum boost mechanism) 1. The master back 1 urges the operating rod (brake pedal interlocking member) 3 linked to the brake pedal 2 to move toward the brake operation side, but the actuator for automatic braking of the automatic braking device for a vehicle (hereinafter, brake actuator). Reference numeral 4 drives the operating rod 3 to the brake operation side, thereby driving a brake piston (not shown) on the caliper side through a master cylinder (not shown) to perform a brake operation.

First, the master back 1 will be described in detail. As shown in FIG. 3, the master back 1 is provided at the rear of a master cylinder (not shown) (ie, the brake pedal 2).
A movable base member 7 interposed between the operating rod 3 connected to the brake pedal 2 and the push rod 5 connected to the master cylinder. ing.

The movable base member 7 is provided coaxially with the operating rod 3 and the push rod 5, and a diaphragm 8 is provided between the outer periphery of the movable base member 7 and the inner periphery of the case 6. . The inside of the case 6 is partitioned by the diaphragm 8 and the movable base member 7 into a negative pressure chamber 9 for introducing engine negative pressure and an atmospheric pressure chamber 10 for introducing atmospheric pressure.

A return spring 11 for biasing the movable base member 7 to the side opposite to the brake operation (ie, rightward in FIG. 3) is provided between the movable base member 7 and the inner wall of the case 6.
When the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 exerts a force greater than the urging force of the return spring 11, the diaphragm 8 and the movable base member 7 move to the brake operation side (that is, 3 is driven to the left.

Between the negative pressure chamber 9 and the atmospheric pressure chamber 10, there is provided a valve (opening / closing) which can communicate these chambers 9, 10 with each other.
Valve 12 is provided. The valve 12 is interposed in the movable base member 7, and is opened when the operating rod 3 is retracted with respect to the movable base member 7, so that the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 is eliminated. When the operating rod 3 moves forward on the brake operation side (that is, leftward in FIG. 3) with respect to the movable base member 7, the operating rod 3 closes and a pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 is reduced. Is to be generated. Operating rod 3
Is urged by a return spring 13 so as to return to the initial position where the valve 12 is opened with respect to the movable base member 7 if no external force is applied.

As a result, if no brake operating force (depressing force on the brake pedal) acts on the operating rod 3, the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 decreases, and the diaphragm is actuated by the biasing force of the return spring 11. 8 and the movable base member 7 are driven to the anti-brake operation side. However, if a brake operation force acts on the operating rod 3, the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 increases, and the return spring 11 is attached. The diaphragm 8 and the movable base member 7 are driven to the brake operation side by the force, so as to apply the brake operation force to the operating rod 3.

The force for driving the operating rod 3 to the brake operation side, that is, the brake operation force is normally given by the driver's depression force through the brake pedal 2.
Brake actuator 4 of the automatic brake device for the vehicle
Is configured to apply a brake operation force to the operating rod 3 instead of the pedaling force of the driver.

Here, the brake actuator 4 will be described.
As shown in FIG. 5, a piston 14 which can abut on the operating rod 3, a hydraulic chamber 15 for applying a hydraulic pressure for driving the piston 14 to the brake operation side, and a hydraulic adjustment for adjusting the hydraulic pressure in the hydraulic chamber 15 It comprises a mechanism 16 and a return spring 17 for urging the piston 14 toward the side opposite to the brake operation.

As shown in FIG. 1, the piston 14 can push the operating rod 3 toward the brake operating side at the rear end (end on the brake pedal 2 side) of the master back 1 as shown in FIG. The operating rod 3 is provided so as not to hinder the advancement of the operating rod 3 toward the brake operation side by being depressed. That is, master back 1
At the rear end of the case 6, a cover 6A is attached,
Inside the cover 6A and the operating rod 3
An annular piston 14 is disposed on the outer periphery of the operating rod 3 along the axis of the operating rod 3. The pressing surface 14 of the flange portion 14A provided on the piston 14
a is on the brake operation side (master back 1) on the pressure receiving surface 3a of the flange portion 3A provided on the operating rod 3.
2 and is in contact with the right side in FIG. 2), and when the piston 14 moves to the brake operation side, the operating rod 3 is pressed to drive to the brake operation side when the piston 14 moves to the brake operation side. The operating rod 3 can freely move to the brake operation side without moving to the side. In addition, 28 shows a dash panel.

As shown in FIG. 2, the hydraulic adjustment mechanism 16 includes a reservoir tank 18 and a hydraulic circuit 19 extending from the tank 18 to the hydraulic chamber 15.
A pump 20 as a hydraulic oil driving means, a flow dividing valve 21, a check valve 22, and an accumulator 2 as a pressure accumulating means are provided in the inside 9
3, automatic brake switching valve 24, pressure control valve (pressure reducing valve) 2
5 are interposed. That is, in this hydraulic circuit, the pump 20 and the accumulator 23 constitute a hydraulic source.

The pump 20 sucks hydraulic oil from the tank 18. The hydraulic oil sucked by the pump 20 is split by the flow dividing valve 21, and a part of the oil is supplied to the four-wheel steering system (4WS). ing. Then, the remaining hydraulic oil is supplied to the power steering system (P / S) and the automatic brake device. The working oil supplied to the automatic brake device is adjusted to a predetermined pressure level by a check valve 22 and an accumulator 23, and then is adjusted to an automatic brake switching valve 24 and a pressure control valve 25.
Is to be led to.

The automatic brake switching valve 24 includes the pressure control valve 2
The valve body 24A is provided with one of an automatic brake operation mode in which hydraulic oil is supplied to the pressure control valve 5 and an automatic brake non-operation mode in which hydraulic oil is not supplied to the pressure control valve 25.
Is urged by the return spring 24B to the valve closing side, that is, the side of the automatic brake non-operation mode. When the solenoid 24C is energized and exerts a magnetic force, it is driven to the valve opening side, that is, the automatic brake operation mode side, and the solenoid 24
If C is not energized, as shown in FIG. 2, the return spring 24B drives the valve to the valve closing side, that is, to the automatic brake non-operation mode side.

The pressure control valve 25 has a valve body 25A capable of adjusting the discharge pressure. The valve body 25A is urged toward the closing side by a return spring 25B.
When C is energized and exerts a magnetic force, the hydraulic oil having a discharge pressure corresponding to the magnetic force is supplied to the hydraulic chamber 15 while being released according to the magnetic force, and excess hydraulic oil is returned to the tank 18, and conversely, the hydraulic chamber is If the pressure on the hydraulic chamber 15 side is high, the hydraulic oil on the hydraulic chamber 15 side is returned to the tank 18 in order to reduce the pressure on the hydraulic chamber 15 side to a discharge pressure corresponding to the magnetic force of the solenoid 25C.

That is, when a current is supplied to the solenoid 24C of the automatic brake switching valve 24, the automatic brake can be operated, and when the current supply to the solenoid 24C is stopped, the automatic brake can be stopped. Sometimes, the solenoid 25C of the pressure control valve 25
By adjusting the current flowing to the hydraulic chamber 15, the hydraulic pressure in the hydraulic chamber 15 can be adjusted, whereby the braking force of the automatic brake can be adjusted.

The solenoids 24C and 25C are
It is controlled by an electronic control unit (ECU) 26
Swelling. For example, in the ECU 26, as shown in FIG.
As shown in FIG.
The inter-vehicle distance L from the vehicle ahead is detected by the
When the separation L becomes equal to or less than the predetermined value, the map A (see FIG. 5) is used.
As shown in the figure, automatic braking is performed according to the distance L between vehicles.
And the degree of approach to the vehicle ahead (ie, negative relative speed)
(Degree: -dL / dt), the degree of approach is a certain degree or more
, As shown in Map B (see FIG. 6),
And apply automatic braking depending on how close you are.
Is set to And how much automatic braking
The action is determined by the following distance L or the degree of approach (-dL / d
target deceleration α according to t)_aWhile setting the vehicle
Actual deceleration α_rActual decrease while detecting with a sensor not shown
Speed α_rIs the target deceleration α_aAutomatic braking until reaching
Actuate and actual deceleration α_rIs the target deceleration α _aReached
Activate the automatic brakes.

When the automatic brake is operated, the pressure control valve 25 is feed-forward controlled without feedback. That is, for example, as shown in FIG. 7, an instruction current I according to the target deceleration α _a is set, and this instruction current I is supplied to the solenoid 25C to reduce the oil pressure in the hydraulic chamber 15 to the target deceleration α _a The brake force of the automatic brake is controlled by adjusting the braking force according to the above. In practice, ECU 26 sets the command voltage V corresponding to the target deceleration alpha _a, the command voltage V Sending to the amplification circuit of the valve drive circuit 27 (Kamp), the command voltage V in the valve drive circuit 27 The corresponding valve drive current (instruction current) I is output to the pressure control valve 25.
Therefore, in the actual control, it is necessary to set the command voltage V corresponding to the target deceleration alpha _a.

FIG. 8 is a diagram showing a dry asphalt road (blurred road).
Various modes in which the command voltage V is changed from a predetermined speed on the
This is the experimental result of deceleration with
Deceleration α_a(Deceleration controllability). Illustrated
In accordance with the command voltage V, the deceleration α_aControl
You can see that Car as one embodiment of the present invention
The dual-purpose automatic brake device is configured as described above.
Then, for example, the automatic brake is operated in the flow shown in FIG.
Move. That is, the actual deceleration α of the vehicle is calculated by a sensor (not shown).
_rIs detected (step S1). On the other hand, for example, FIG.
As shown in FIG. 4, the following distance L to the vehicle ahead and the
Each map according to the degree of approach (-dL / dt)
From the target (see FIGS. 5 and 6) _aSet (S
Step S2).

[0039] Then, it is determined whether the actual deceleration alpha _r is the target deceleration alpha _a less (step S3), and the actual deceleration alpha _r is if the target deceleration alpha _a less, the process proceeds to step S4, the automatic brake switch The valve 24 is turned on to activate the automatic brake. That is, current is supplied to the solenoid 24C of the automatic brake switching valve 24 to open the automatic brake switching valve 24.

Then, the routine proceeds to step S5, where the operation of the pressure control valve (pressure reducing valve) 25 is controlled. That is, the ECU 26
Then, the command voltage V corresponding to the target deceleration α _a is sent to the valve drive circuit, and the valve drive circuit outputs a valve drive current (command current) I corresponding to the command voltage V to the pressure control valve 25. As a result, the hydraulic pressure in the hydraulic chamber 15 is adjusted, and the piston 14 is driven to the brake operation side in accordance with the hydraulic pressure, and accordingly, the operating rod 3 is also driven to the brake operation side. Then, by operating the master cylinder push rod 5 in conjunction with the operating rod 3 is moved to the brake operating side, caliper brake piston (not shown) is driven, such as responding to the target deceleration alpha _a brake Power is given through wheels.

When the actual deceleration α _r reaches the target deceleration α _a by performing such control of the pressure control valve 25, the process proceeds from step S3 to step S6 to turn off the automatic brake switching valve 24. Switch to stop the automatic brake. That is, the current supply to the solenoid 24C of the automatic brake switching valve 24 is stopped, and the automatic brake switching valve 2 is stopped.
4 is closed.

As described above, in the automatic brake device for a vehicle, the brake control of the automatic brake is performed using the hydraulic oil (liquid) which is an incompressible fluid instead of using the air which is a compressible fluid. Therefore, control responsiveness can be improved, and the maximum control pressure can be easily set large. Further, even when such an automatic brake is operated, the valve 12 of the master bag 1 is closed with the movement of the operating rod 3 toward the brake operation side, and the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 is increased. The force exerts a brake operating force on the operating rod 3.

Thus, using an incompressible fluid,
And by using the support of the master back 1,
Even if the supply hydraulic pressure to the hydraulic chamber 15 is set relatively small,
By the energization of the master back 1, the master cylinder can be driven by a sufficient amount at a sufficient speed. That is, there is an advantage that a sufficient control response and a sufficient maximum control amount can be obtained while the brake actuator 4 is downsized. Of course, brake control can be performed without increasing energy consumption, and sufficient braking force can be obtained.

When the automatic brake is not operated, the supply of the current to the solenoid 24C of the automatic brake switching valve 24 is stopped. As a result, the piston 14 is held at the retracted position, but the operating rod 3 can freely move to the brake operation side without being restrained by the piston 14, so that when the brake pedal 2 is depressed, the operating rod 3 is braked. The operating rod 3 and the push rod 5 are moved to the brake operating side to move the brake cylinder to the operating side while receiving the bias of the master back 1 to actuate the master back 1, the brake piston on the caliper side is driven, and the brake pedal 2 is depressed. Is applied through the wheels.

When the control system of the automatic brake device for the vehicle fails, that is, the solenoid 24C of the automatic brake switching valve 24 and the solenoid 25C of the pressure control valve 25
When current cannot be supplied to the brake pedal 2, the piston 14 is held at the retracted position and the brake pedal 2
The braking performance according to is ensured without any loss.

Further, the present vehicle automatic brake system is different from the existing vehicle brake system having the master back 1 in that:
The brake actuator 4, that is, the piston 14, the hydraulic chamber 15, the hydraulic adjustment mechanism 16, and the return spring 17
By simply adding, the existing device can be easily installed while making the most of the existing device, which is advantageous in terms of cost. Of course, if a hydraulic system for power steering is provided as in the brake device of the present embodiment, this hydraulic system for power steering can be used for the hydraulic adjustment mechanism 16, which is more advantageous in cost.

By the way, on the basis of the map shown in FIG. 7 or 8, in accordance with the target deceleration alpha _a, means for controlling the command current I or command voltage V, the driver is braking during the automatic braking operation Although the case where the pedal 2 is depressed is not taken into consideration, in this device, the driver can freely depress the brake pedal 2 and apply a braking force during the operation of the automatic brake, so it is necessary to consider this point. .

That is, as shown in FIG. 10, when the command voltage V is set by the ECU 26, a valve drive current I corresponding to the command voltage V is supplied from the valve drive circuit 27 to the pressure control valve (pressure reducing valve) 25. Then, the hydraulic pressure P corresponding to the valve drive current I is output through the pressure control valve 25. Then, a force AP corresponding to the product of the hydraulic pressure P and the area A of the piston 14 is applied from the piston 14 to the operating rod pressing force (brake operating force by the automatic brake) F1.
(= AP) is given to the operating rod 3.

On the other hand, when the driver depresses the brake pedal 2, a force F2 obtained by multiplying the driver's depressing force by the pedal ratio of the brake pedal 2 is applied to the operating rod 3 as an operating rod pressing force (a driver's braking operation force). As a result, a resultant force F3 (= F1 + F2) of the two pressing forces F1 and F2 is input to the operating rod 3 (corresponding to the and circuit in FIG. 10). The resultant force F3
F4 that is the reaction force kx of the return spring 11 reduced from
(F3-kx) operates, and in the master cylinder, according to the master back characteristic (see the characteristic diagram in FIG. 10) (this input F4
Is output. The force Am · P corresponding to the product of the discharge pressure Pb and the piston area Am of the caliper brake cylinder is the braking force F5 (= A
m · P) to the vehicle.

Thus, the control parameter V is
Although it is on the upstream side of the operating rod 3 corresponding to the circuit, the control target is on the downstream side of the operating rod 3. Therefore, as a control system, parameters downstream of the coupling section (and circuit) are feedback controlled or fed forward. It is necessary to set a control amount (control parameter V) by control.

As one means, for example, a brake fluid pressure, which is a parameter downstream of the connecting portion (and circuit), is predicted from a state in which the brake pedal 2 of the driver is depressed, and feedforward control based on the prediction is performed. Can be considered.

[0052]

As described above in detail, according to the automatic brake apparatus for a vehicle according to the first aspect of the present invention, a brake pedal interlocking member that moves forward and backward to operate the master cylinder in conjunction with the brake pedal, and the brake A diaphragm connected to the pedal interlocking member; a negative pressure chamber and an atmospheric pressure chamber partitioned by the diaphragm; A vacuum booster mechanism comprising an on-off valve for generating a pressure difference between the negative pressure chamber and the atmospheric pressure chamber is provided, and the brake pedal interlocking member is operated even when the brake pedal is not depressed. An actuator for automatic braking that can be driven to the side to operate the master cylinder; Can be pressed toward the brake operation side with respect to the brake pedal interlocking member, but the brake pedal interlocking member is prevented from depressing the brake pedal to prevent the brake pedal interlocking member from advancing to the brake operation side. A piston installed so as to be able to abut, a hydraulic chamber capable of applying hydraulic pressure to the piston for driving the piston toward the brake operation side, a hydraulic adjustment mechanism for adjusting the hydraulic pressure in the hydraulic chamber, and The following effects and advantages can be obtained by including the return spring that biases in the direction opposite to the side. (1) Since an incompressible fluid is used and the boost of the vacuum booster mechanism is used, a sufficient control response and a sufficient maximum control amount (that is, a braking force) can be obtained while miniaturizing the actuator for automatic braking. There is an advantage to become. Of course, the brake control can be performed without increasing the energy consumption. (2) A normal brake operation through the brake pedal can be applied even when the automatic brake device is operated. Also, when the control system of the automatic brake device fails, the normal brake operation through the brake pedal can be performed. Brake operation performance can be secured. (3) It can be installed simply by adding a brake actuator to an existing vehicle brake device having a vacuum booster mechanism, and can be easily installed at low cost while maximizing the use of the existing device.

[0053] Further, according to the automatic braking system for a vehicle of the present invention according to claim 1, disposed a shaft-shaped member as the brake pedal interlocking member through the center of the main body of the vacuum booster mechanism And a pressure receiving surface for receiving a pressing force toward the brake operating side is formed on an outer periphery of the brake pedal interlocking member, and the piston comes into contact with the pressure receiving surface to apply a pressing force to the brake operating side. Is formed, it is possible to apply the above-mentioned effect (2), that is, a normal brake operation through the brake pedal even when the automatic brake device is operated, and also to provide the automatic brake device. Thus, the effect that the normal brake operation performance through the brake pedal can be ensured even when the control system or the like fails will be obtained more reliably.

[0054]

Further, the vehicle automatic of the present invention according to claim 2 is provided.
According to the brake device, in the configuration according to claim 1,
The hydraulic adjustment mechanism is provided with a hydraulic source, an oil path interposed between the hydraulic source and the hydraulic chamber, and interposed in the middle of the oil path, and supplies hydraulic oil from the hydraulic source to the hydraulic pressure. a switching valve which includes a stop mode for stopping the feeding mode and feed to feed the chamber, by composed of a pressure control valve for controlling the hydraulic pressure of the hydraulic oil is fed through the switching valve, Appropriate hydraulic control can be performed, and the performance of automatic braking can be improved.

Further, the vehicle automatic according to the third aspect of the present invention.
According to the brake device, in the structure of claim 1 or 2,
There, some of the hydraulic power source and the oil passage of the oil pressure adjusting mechanism is less of a hydraulic four-wheel steering system and the vehicle for automatic steering apparatus for a vehicle
By using both of them together, the configuration of the hydraulic system is simplified, and in configuring comprehensive automatic control of the vehicle,
Advantages such as miniaturization of the apparatus and reduction in installation cost can be obtained.

[0057]

[0058]

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a vacuum boosting mechanism showing a main configuration of an automatic brake actuator of a vehicle automatic brake device as one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a hydraulic adjustment mechanism of an automatic brake actuator of a vehicle automatic brake device as one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a vacuum booster mechanism provided in a brake system having an automatic braking device for a vehicle as one embodiment of the present invention.

FIG. 4 is a diagram showing a signal processing system for setting a target deceleration used for automatic brake control of the vehicle automatic brake device as one embodiment of the present invention.

FIG. 5 is a diagram showing a map for setting a target deceleration used for automatic brake control of the vehicle automatic brake device as one embodiment of the present invention.

FIG. 6 is a diagram showing a map for setting a target deceleration used for automatic brake control of the vehicle automatic brake device as one embodiment of the present invention.

FIG. 7 is a diagram showing the relationship between deceleration and command current in automatic brake control of the automatic brake device for a vehicle as one embodiment of the present invention.

FIG. 8 is a diagram showing an experimental result of a relationship between deceleration and control voltage in automatic brake control of the automatic brake device for a vehicle as one embodiment of the present invention.

FIG. 9 is a flowchart showing a procedure of automatic brake control of the vehicle automatic brake device as one embodiment of the present invention.

FIG. 10 is a schematic block diagram showing a transmission path of a braking force of a brake system provided with an automatic braking device for a vehicle as one embodiment of the present invention.

11 is a schematic diagram showing an automatic braking device for a vehicle using the actuator of a conventional electric-motor system.

[Explanation of symbols]

Reference Signs List 1 master back (vacuum booster mechanism) 2 brake pedal 3 operating rod (brake pedal interlocking member) 3A flange portion 3a pressure receiving surface 4 actuator for automatic braking (brake actuator) 5 push rod 6 case 6A cover 7 movable base member 8 diaphragm 9 Negative pressure chamber 10 Atmospheric pressure chamber 11 Return spring 12 Valve (open / close valve) 13 Return spring 14 Piston 14A Flange part 14a Pressing surface 15 Hydraulic chamber 16 Hydraulic pressure adjusting mechanism 17 Return spring 18 Reservoir tank 19 Hydraulic circuit 20 Hydraulic oil drive means Pump (Hydraulic source) 21 Split valve 22 Check valve 23 Accumulator (Hydraulic source) as accumulator 24 Automatic brake switching valve 25 Pressure control valve (Reducing valve) 24A Valve body 24B Return sp Ring 24C solenoid 25A valve body 25B return spring 25C solenoid electronic control unit (ECU) 27 valve driving circuit 28 dash panel

Continued on the front page (72) Inventor Takahiro Maemura 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Tadao Tanaka 5-33-8 Shiba 5-chome, Minato-ku, Tokyo Mitsubishi (56) References JP-A-1-204845 (JP, A) JP-A-51-63085 (JP, U) JP-A-3-503515 (JP, A) (58) Fields surveyed ( Int.Cl. ⁷ , DB name) B60T ⁷ /12-7/22 B60T 8/00 B60T 8/32-8/96 B60T 13/00-17/22 B62D 5/07

Claims (3)

(57) [Claims] 1. A brake pedal interlocking member which moves forward and backward in conjunction with a brake pedal to operate a master cylinder, a diaphragm connected to the brake pedal interlocking member, a negative pressure chamber and an atmospheric pressure chamber partitioned by the diaphragm. An opening / closing valve for generating a pressure difference between the negative pressure chamber and the atmospheric pressure chamber in conjunction with the brake pedal interlocking member to assist the depression force of the brake pedal when the brake pedal is depressed. An automatic brake actuator capable of operating the master cylinder by driving the brake pedal interlocking member to the brake operation side even when the brake pedal is not depressed, and Actuator for pressing the brake pedal interlocking member toward the brake operation side. A piston installed so as to be able to abut the brake pedal interlocking member so as not to hinder the advancement of the brake pedal interlocking member to the brake operation side by depressing a brake pedal; and a brake operation side with respect to the piston. a hydraulic chamber which can provide the hydraulic pressure for driving to a hydraulic adjusting mechanism for adjusting the hydraulic pressure chamber of the hydraulic, the piston is configured to include a return spring and the brake operation side to urge the opposite direction, the The brake pedal interlocking member is inside the main body of the vacuum booster.
A shaft-shaped member disposed so as to penetrate the heart , wherein the brake operation side
A pressure receiving surface that receives a pressing force toward the piston is formed, and the piston comes into contact with the pressure receiving surface toward the brake operation side.
An automatic braking device for a vehicle, characterized in that a pressing surface for applying a pressing force is formed . 2. The hydraulic pressure adjusting mechanism according to claim 1, further comprising: a hydraulic pressure source; an oil passage interposed between the hydraulic pressure source and the hydraulic chamber; and an oil passage interposed in the oil passage . Hydraulic oil
Feed mode to feed the hydraulic chamber and stop mode to stop the feed
And a pressure for controlling the hydraulic pressure of the hydraulic oil supplied through the switching valve.
The vehicle automatic brake device according to claim 1, further comprising a force control valve . 3. A hydraulic pressure source and a part of an oil passage of the hydraulic pressure adjusting mechanism.
Is a hydraulic four-wheel steering system for vehicles and an automatic steering system for vehicles.
Characterized by being used in combination with at least one of
The automatic brake device for a vehicle according to claim 1 or 2.