JPH07205781A - Automatic brake device for vehicle - Google Patents

Abstract

PURPOSE:To give a fail safe function and to improve responsiveness by providing a piston, set up so as not to disturb advancing a brake pedal interlocking member to a brake operation side but come into contact with the brake pedal interlocking member, a hydraulic pressure adjusting mechanism relating to the piston and a return spring, in an actuator. CONSTITUTION:Moving a brake pedal interlocking member 3 in a vehicle use automatic brake device is driven by an automatic brake use actuator 4. This brake actuator 4 comprises a piston 14, pressure oil chamber 15 for giving pressure oil to this piston, its hydraulic pressure adjusting mechanism and a return spring 17 for energizing the piston 14 to an opposite brake operation side. The piston 14 is provided in a manner wherein the brake pedal interlocking member 3 can be pressed to a brake operation side but prevented from disturbing an advance to the operation side. A flange part 14A of the piston 14 is brought into contact with a flange part 3A of the brake pedal interlocking member 3, and it can be freely moved to the brake operation side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular automatic brake device suitable for use in automatic steering of an automobile.

[0002]

2. Description of the Related Art Conventionally, an automatic brake device for a vehicle has been developed which automatically brakes the vehicle, for example, by preventing the vehicle (generally an automobile) from running out of control. An important component is the brake actuator (ie, the actuator for automatic braking). Moreover, in such an automatic braking device,
The automatic brake must be able to be operated without deteriorating the performance of the brake (conventional brake) normally operated by the driver, and in particular, the configuration of the brake actuator becomes important.

As such a brake actuator,
For example, anti-lock brake system (hereinafter referred to as A
It is considered to use a hydraulic brake actuator used in the BS). Further, as such a brake actuator, for example, an electric motor type actuator as shown in FIG. 11 can be considered. This system is 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 that supplies hydraulic pressure corresponding to brake operation). From a hydraulic pressure supply / discharge line 103 and a switching valve (OR valve) 104 capable of selecting any one of the conventional hydraulic pressure line 102 and the electric motor type hydraulic pressure supply / discharge line 103 and introducing the selected hydraulic pressure line 102 to the caliper 101 side. Become.

The electric motor type hydraulic supply / discharge line 103 includes an electric motor 105, and the electric motor 105 and the gear mechanism 1.
Ball screw type piston mechanism 10 connected via 07
The ball screw type piston mechanism 106 includes a ball screw 108 connected to a gear mechanism 107, a piston 109 that is screwed into the ball screw 108 and moves forward and backward by the rotation of the ball screw 108, and expands and contracts by the forward and backward movement of the piston 109. And an oil chamber 110.

When the switching valve 104 opens the electric motor type hydraulic pressure supply / discharge line 103, the rotation of the electric motor 105 is rotated through the gear mechanism 107.
8 to drive the piston 109 forward,
The oil chamber 110 is contracted to drive a hydraulic piston (not shown) on the caliper 101 side to generate a braking force.

[0006] Further, JP-A-4-262957, JP-A-4-303060, and JP-A-4-310460.
Japanese Patent Laid-Open No. 4-339066 discloses a proposal to apply a negative pressure type brake booster (that is, a vacuum booster mechanism) 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 specific 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 automatic braking device using the hydraulic brake actuator used in the above-described ABS, during automatic braking, the hydraulic pressure of the brake is controlled by the actuator irrespective of the depression amount 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 possible.

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

In the automatic brake device utilizing the vacuum booster mechanism, although it is easy to deal with a failure, 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 speed of the brake fluid pressure cannot be increased, and sudden braking cannot be generated. The present invention has been devised in view of the above problems. Even when the automatic braking system fails, the driver can operate the brake pedal to obtain a normal braking force, and the control performance is high and responsive. It is an object of the present invention to provide an automatic braking device for a vehicle, which is capable of automatic braking with.

[0010]

Therefore, the vehicle automatic brake device of the present invention according to claim 1 is a brake pedal interlocking member for advancing and retreating in conjunction with the brake pedal to operate the master cylinder, and the brake pedal interlocking member. A diaphragm connected to the member, a negative pressure chamber and an atmospheric pressure chamber partitioned by the diaphragm, and the brake pedal interlocking member interlocking with the brake pedal interlocking member to assist the depression force of the brake pedal when the brake pedal is depressed. A vacuum booster mechanism including an on-off valve that causes a pressure difference between the negative pressure chamber and the atmospheric pressure chamber is provided, and the brake pedal interlocking member is braked even if the brake pedal is not depressed. And an actuator for automatic braking that can drive the master cylinder to operate the master cylinder. The brake pedal interlocking member against the brake operation side, but 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. A piston installed so that it can abut
A hydraulic chamber capable of giving a hydraulic pressure for driving the piston to the brake operating side, a hydraulic pressure adjusting mechanism for adjusting the hydraulic pressure in the hydraulic chamber, and a return spring for biasing the piston in a direction opposite to the brake operating side. It is characterized by being configured with.

According to a second aspect of the present invention, there is provided the vehicle automatic brake device according to the first aspect, wherein the brake pedal interlocking member is disposed so as to penetrate the center of the main body of the vacuum booster mechanism. A pressure receiving surface that receives a pressing force toward the brake operating side is formed on the outer circumference of the brake pedal interlocking member, and the piston is brought into contact with the pressure receiving surface and the brake is applied. It is characterized in that a pressing surface for applying a pressing force to the operating side is formed.

According to a third aspect of the present invention, there is provided a vehicle automatic brake device according to the first or second aspect.
A cover member that covers the rear end of the case member of the vacuum booster mechanism body is mounted, and the piston is housed in a closed space covered by the cover member and the rear end surface of the case member. I am trying. Also, in the vehicle automatic brake device according to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the hydraulic pressure adjusting mechanism includes a hydraulic pressure source, a hydraulic pressure source, and the pressure chamber. An oil passage interposed between the oil passage and a supply mode in which the hydraulic oil from the hydraulic source is supplied to the pressure chamber and a stop mode in which the supply is stopped. And a pressure control valve for controlling the hydraulic pressure of the hydraulic fluid fed through the switching valve.

According to a fifth aspect of the present invention, there is provided an automatic vehicle brake system according to the fourth aspect, wherein a part of a hydraulic source and an oil passage of the hydraulic adjusting mechanism is a hydraulic four-wheel steering system for a vehicle. It is characterized by being used together with the device. Further, in the vehicle automatic brake device according to a sixth aspect of the present invention, in the configuration according to the fourth or fifth aspect, a part of the hydraulic pressure source and the oil passage of the hydraulic pressure adjusting mechanism is used in combination with the automatic vehicle steering device. It is characterized by

According to a seventh aspect of the present invention, there is provided a vehicle automatic brake system according to any one of the fourth to sixth aspects, wherein the hydraulic power source sucks hydraulic fluid from a tank and hydraulic fluid drive means. And a pressure accumulating means for storing the hydraulic oil from the hydraulic oil driving means.

[0015]

In the automatic vehicular brake device of the present invention as set forth in claim 1, the automatic brake actuator can drive the piston to the brake operating side by applying hydraulic pressure to the hydraulic chamber through the hydraulic pressure adjusting mechanism. When the piston advances to the brake operating side, the brake pedal interlocking member is driven to the brake operating 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. As a result, the brake can be automatically applied.

Further, at this time, in the vacuum booster mechanism, the on-off valve interlocks with the brake pedal interlocking member to cause a pressure difference between the negative pressure chamber and the atmospheric pressure chamber, so that the brake operation of the brake pedal interlocking member is performed. The drive to the side is assisted by this vacuum booster mechanism, and an automatic brake can be applied more quickly. Further, since the piston is installed so as not to interfere with the forward movement of the brake pedal interlocking member toward the brake operating side due to the depression of the brake pedal, the driver depresses the brake pedal when he wants to apply the brake to the vehicle. Thus, the brake pedal can be applied to the vehicle by moving the brake pedal interlocking member to the brake operating side and using the assistance of the vacuum booster mechanism to operate the master cylinder to the side where the braking force is generated.

In the vehicle automatic brake device according to the second aspect of the present invention, when the piston according to the first aspect is operated, the piston is driven toward the brake operating side.
The pressing surface formed on the piston contacts the pressure receiving surface formed on the outer periphery of the brake pedal interlocking member to apply a pressing force toward the brake operating side. As a result, the brake pedal interlocking member is driven to the brake operating side,
The master cylinder is operated to the side where the braking force is generated,
Automatic braking is applied.

On the other hand, since the pressing surface of the piston is in contact with the pressure receiving surface of the brake pedal interlocking member but is not particularly connected, the pressure receiving surface can be freely separated from the pressing surface, whereby the piston is moved. A state is achieved in which the forward movement of the brake pedal interlocking member toward the brake operating side due to the depression of the brake pedal is not hindered. In the vehicle automatic brake device according to the third aspect of the present invention, the cover member is attached to the rear end of the case member of the vacuum booster mechanism main body, and the piston is internally provided inside the case member, so that the piston and the hydraulic pressure are increased. Since the chamber can be provided, the present apparatus can be formed even if the cover member or the piston is retrofitted by utilizing the existing vacuum booster mechanism main body.

In the vehicle automatic brake device according to the fourth aspect of the present invention, in the hydraulic pressure adjusting mechanism, the switching valve is set to either the feed mode or the stop mode, but the feed mode is set. Then, it becomes possible to feed the hydraulic oil from the hydraulic source to the pressure chamber through an oil passage, and while controlling the hydraulic pressure of the hydraulic oil fed through the switching valve by the pressure control valve, The hydraulic pressure of the pressure chamber is adjusted.
Further, when the switching valve is set to the stop mode, the supply of the hydraulic oil from the hydraulic pressure source to the pressure chamber is stopped.

In the vehicle automatic brake device according to the fifth aspect of the present invention, the structure of the hydraulic system is simplified. In the vehicle automatic brake device according to the sixth aspect of the present invention, the configuration of the hydraulic system is simplified. In the vehicle automatic brake device according to the seventh aspect of the present invention, when the hydraulic oil drive means sucks the hydraulic oil from the tank, the hydraulic oil from the hydraulic oil drive means is stored in the pressure accumulating means. Therefore, a stable working oil pressure can be obtained as a hydraulic pressure source.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle automatic brake device as an embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a partial cross-sectional view of a vacuum booster mechanism showing the essential structure of the automatic brake actuator. 2 is a schematic configuration diagram showing the 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, this vehicle automatic brake device is attached to a brake device having a master back (vacuum booster mechanism) 1. The master back 1 urges a movement of an operating rod (brake pedal interlocking member) 3 interlocking with a brake pedal 2 toward a brake operating side, but an automatic brake actuator (hereinafter referred to as a brake actuator) of the automatic brake device for a vehicle. Reference numeral 4 drives the operating rod 3 toward the brake operating side, thereby driving a brake piston (not shown) on the caliper side through a master cylinder (not shown) to perform the brake operation.

First, the master back 1 will be described in detail. As shown in FIG. 3, the master back 1 is a rear portion of the master cylinder (not shown) (that is, the brake pedal 2).
And a master cylinder), and 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 in the case 6. 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 divided by the diaphragm 8 and the movable base member 7 into a negative pressure chamber 9 into which engine negative pressure is introduced and an atmospheric pressure chamber 10 into which atmospheric pressure is introduced.

Further, between the movable base member 7 and the inner wall of the case 6, a return spring 11 for urging the movable base member 7 toward the anti-brake operation side (that is, right side in FIG. 3).
When the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 exerts a force larger than the urging force of the return spring 11, the diaphragm 8 and the movable base member 7 are placed on the brake operation side (that is, In FIG. 3, it is driven to the left).

A valve 12 is provided between the negative pressure chamber 9 and the atmospheric pressure chamber 10 so that the chambers 9 and 10 can communicate with each other. The valve 12 is interposed in the movable base member 7 and opens when the operating rod 3 is retracted with respect to the movable base member 7 to eliminate the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10. Then, when the operating rod 3 moves forward with respect to the movable base member 7 toward the brake operating side (that is, to the left in FIG. 3), the operating rod 3 closes and the negative pressure chamber 9
And a pressure difference between the atmospheric pressure chamber 10 and the atmospheric pressure chamber 10. Further, the operating rod 3 is biased by the 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 when no external force is applied.

As a result, unless the operating force of the brake is applied to the operating rod 3 (stepping force of the brake pedal), the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 is reduced and the diaphragm is urged by the return spring 11. 8 and the movable base member 7 are driven to the anti-brake operation side, but if the brake operating 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, and the brake operation force to the operating rod 3 is applied.

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

The brake actuator 4 will be described below with reference to FIG.
As shown in FIG. 3, a piston 14 that can abut the operating rod 3, a hydraulic chamber 15 for giving a hydraulic pressure to drive the piston 14 to the brake operating side, and a hydraulic adjustment for adjusting the hydraulic pressure in the hydraulic chamber 15 are shown. It has a mechanism 16 and a return spring 17 for urging the piston 14 toward the anti-brake operation side.

Of these, as shown in FIG. 1, the piston 14 can press the operating rod 3 toward the brake operating side at the rear end of the master back 1 (end on the brake pedal 2 side). It is provided so as not to hinder the forward movement of the operating rod 3 toward the brake operating side due to depression. That is, master back 1
A cover 6A is attached to the rear end of the case 6 of
Inside the cover 6A and the operating rod 3
An annular piston 14 is arranged on the outer periphery of the operating rod 3 along the axial center of the operating rod 3. The pressing surface 14 of the flange portion 14A provided on the piston 14
a is on the pressure receiving surface 3a of the flange portion 3A provided on the operating rod 3 on the brake operating side (master back 1
2 is in contact with from the right side in FIG. 2, and when the piston 14 moves to the brake operating side, it exerts a pressing force on the operating rod 3 to drive it to the brake operating side. Even if the operating rod 3 does not move to the side, the operating rod 3 can freely move to the brake operating side. In addition, 28 shows a dash panel.

As shown in FIG. 2, the hydraulic pressure adjusting mechanism 16 is provided with a reservoir tank 18 and a hydraulic circuit 19 from the tank 18 to the hydraulic chamber 15.
A pump 20, a shunt valve 21, a check valve 22, and an accumulator 2 as a pressure accumulator, which serve as a hydraulic oil drive means, are provided in the interior 9.
3, automatic brake switching valve 24, pressure control valve (pressure reducing valve) 2
5 is installed. That is, in this hydraulic circuit, the hydraulic pressure source is configured by the pump 20 and the accumulator 23.

The pump 20 sucks the hydraulic oil from the tank 18, and the hydraulic oil sucked by the pump 20 is divided by the flow dividing valve 21 and a part of the hydraulic 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 braking device. The hydraulic oil supplied to the automatic brake device is adjusted to a predetermined pressure level by the check valve 22 and the accumulator 23, and then the automatic brake switching valve 24 and the pressure control valve 25.
It is supposed to be guided to.

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

The pressure control valve 25 has a valve body 25A capable of adjusting the discharge pressure, and the valve body 25A is biased to the closing side by a return spring 25B, and the solenoid 25
When C is energized and exerts a magnetic force, hydraulic oil having a discharge pressure corresponding to the magnetic force is supplied to the hydraulic chamber 15 while opening according to the magnetic force, and excess hydraulic oil is returned to the tank 18, and conversely If the pressure on the side of the hydraulic chamber 15 is high, the hydraulic oil on the side of the hydraulic chamber 15 is returned to the tank 18 in order to lower the pressure on the side of the hydraulic chamber 15 to the 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, and the automatic brake is operated. Sometimes the solenoid 25C of the pressure control valve 25
It is possible to adjust the hydraulic pressure in the hydraulic chamber 15 by adjusting the electric current to the brake chamber, thereby adjusting the braking force of the automatic brake.

The solenoids 24C and 25C are
It is controlled by an electronic control unit (ECU) 26.
Growling. For example, in the ECU 26, as shown in FIG.
As shown in FIG.
The inter-vehicle distance L with the vehicle ahead is detected by the
When the distance L is below a certain value, use map A (see Fig. 5)
As shown, the automatic brake is activated according to the inter-vehicle distance L.
And the degree of approach to the vehicle in front (ie, the negative relative speed
Degree: -dL / dt), the degree of approach is a certain degree or more
Then, as shown in Map B (see FIG. 6),
Depending on the degree of approach, automatic braking may be applied.
Is set. And how much automatic braking
The distance between vehicles L and the degree of approach (-dL / d)
target deceleration α according to t)_aWhile setting the
Actual deceleration α_rIs detected by a sensor (not shown)
Speed α_rIs the target deceleration α_aAutomatic braking until reaching
Operate the actual deceleration α_rIs the target deceleration α _aHas reached
The automatic brake is activated.

When the automatic brake is operated, the pressure control valve 25 is feedforward-controlled without using feedback. That is, for example, as shown in FIG. 7, an instruction current I corresponding to the target deceleration rate α _a is set, and this instruction current I is supplied to the solenoid 25C so that the hydraulic pressure in the hydraulic chamber 15 is reduced to the target deceleration rate α _a. That is, the braking force of the automatic brake is controlled by adjusting to the one according to. Actually, the ECU 26 sets an instruction voltage V according to the target deceleration rate α _a and sends this instruction voltage V to the amplification circuit (Kamp) of the valve drive circuit 27. A corresponding valve drive current (instruction current) I is output to the pressure control valve 25.
Therefore, in actual control, it is necessary to set the instruction voltage V according to the target deceleration rate α _a .

FIG. 8 shows a dry asphalt road (blurred).
On various roads where the indicated voltage V is changed from the specified speed on the
It is an experimental result of deceleration by the mode, and
Deceleration α_aShows the change (deceleration controllability). Illustration
As shown in FIG._aControl of
You can see that Vehicle as an Example of the Present Invention
The dual-purpose automatic braking device is constructed as described above.
Then, for example, in the flow shown in Fig. 9, create an automatic brake.
To move. That is, the actual deceleration α of the vehicle is detected by a sensor (not shown).
_rIs detected (step S1), and on the other hand, for example,
As shown in 4, the inter-vehicle distance L to the vehicle in front and the front
According to the degree of approach (-dL / dt) to the vehicle of
(See Fig. 5 and 6) _aTo set
Step S2).

Then, it is judged whether or not the actual deceleration α _r is less than or equal to the target deceleration α _a (step S3). If the actual deceleration α _r is less than or equal to the target deceleration α _a , the process proceeds to step S4 and automatic brake switching is performed. Set valve 24 on to activate the automatic brake. That is, a current is supplied to the solenoid 24C of the automatic brake switching valve 24 to open the automatic brake switching valve 24.

Then, in step S5, 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 rate 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, the piston 14 is driven to the brake operating side in accordance with this hydraulic pressure, and the operating rod 3 is also driven to the brake operating side accordingly. Then, in conjunction with the operating rod 3, the push rod 5 moves to the brake operating side to operate the master cylinder, the brake piston (not shown) on the caliper side is driven, and the brake that responds to the target deceleration α _a. Power is given through the wheels.

When the actual deceleration α _r reaches the target deceleration α _a by controlling the pressure control valve 25 as described above, the process proceeds from step S3 to step S6 to turn off the automatic brake switching valve 24. Switch to stop automatic braking. 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
4 is closed.

As described above, in the automatic brake device for a vehicle of the present invention, the brake control of the automatic brake is performed not by using the air which is the compressible fluid but by using the working oil (the liquid) which is the incompressible fluid. Therefore, the control response can be improved, and the maximum control pressure can be easily set to a large value. Further, even when such an automatic brake is operated, the valve 12 of the master bag 1 is closed due to the movement of the operating rod 3 to the brake operating side, and the pressure difference between the negative pressure chamber 9 and the atmospheric pressure chamber 10 is caused. The force exerts a braking force on the operating rod 3.

Thus, using an incompressible fluid,
And by using the energizing of the master back 1,
Even if the hydraulic pressure supplied to the hydraulic chamber 15 is set to be relatively small,
By energizing the master back 1, the master cylinder can be driven at a sufficient speed and by a sufficient amount. 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, the brake control can be performed without causing an increase in energy consumption, and a sufficient braking force can be obtained.

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

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

Further, the automatic brake device for a vehicle is the same as the existing vehicle brake device having the master back 1.
Brake actuator 4, that is, piston 14, hydraulic chamber 15, hydraulic adjusting mechanism 16, and return spring 17
It is possible to easily install the existing device while making the best use of the existing device only by adding, and it is also advantageous in terms of cost. Of course, if the hydraulic system for the power steering is provided as in the brake device of the present embodiment, the hydraulic system for the power steering can be used for the hydraulic pressure adjusting mechanism 16, which is more cost effective.

By the way, the means for controlling the instruction current I or the instruction voltage V according to the target deceleration α _a based on the map as shown in FIG. 7 or FIG. 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 to apply the braking force during the operation of the automatic brake, so this point needs to be taken into consideration. .

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

On the other hand, when the driver depresses the brake pedal 2, a force F2 obtained by multiplying the pedal effort of the driver by the pedal ratio of the brake pedal 2 is applied to the operating rod 3 as an operating rod pressing force (brake operating force by the driver). As a result, the resultant force F3 (= F1 + F2) of the two pressing forces F1 and F2 is input to the operating rod (corresponding to the and circuit in FIG. 10) 3. For the master back 1, this resultant force F3
The force F4 obtained by subtracting the reaction force kx of the return spring 11 from
(F3-kx) operates, and the master cylinder responds to the master back characteristic (see the characteristic diagram in FIG. 10) (this input F4
The discharge pressure Pb corresponding to is output. Then, the force Am · P corresponding to the product of the discharge pressure Pb and the piston area Am of the brake cylinder on the caliper side is the braking force F5 (= A
m · P) is given to the vehicle.

As described above, the control parameter V is and
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, so that the control system uses feedback control or feedforward for parameters on the downstream side of the coupling portion (and circuit). It is necessary to set the controlled variable (control parameter V) by control.

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

[0052]

As described in detail above, according to the vehicle automatic brake device of the present invention as set forth in claim 1, a brake pedal interlocking member for advancing and retracting in conjunction with the brake pedal to operate the master cylinder, and the brake. A diaphragm connected to the pedal interlocking member, a negative pressure chamber and an atmospheric pressure chamber partitioned by the diaphragm, and an interlocking member with the brake pedal interlocking member for assisting the depression force of the brake pedal when the brake pedal is depressed. A vacuum booster mechanism including an on-off valve that creates a pressure difference between the negative pressure chamber and the atmospheric pressure chamber is provided, and the brake pedal interlocking member is braked even if the brake pedal is not depressed. And an actuator for automatic braking that can drive the master cylinder to operate the master cylinder. However, the brake pedal interlocking member may be pressed to the brake operation side with respect to the brake pedal interlocking member, but the brake pedal interlocking member is provided so as not to prevent the brake pedal interlocking member from advancing toward the brake operation side by depressing the brake pedal. A piston installed so as to be able to abut, a hydraulic chamber capable of giving a hydraulic pressure for driving the piston toward the brake operating side, a hydraulic pressure adjusting mechanism for adjusting the hydraulic pressure in the hydraulic chamber, and a brake operation for the piston. By being configured with a return spring that biases in the opposite direction to the side, the following effects and advantages can be obtained. (1) Sufficient control response and sufficient maximum control amount (that is, braking force) can be obtained while downsizing the actuator for automatic braking by using non-compressible fluid and utilizing the force of the vacuum booster mechanism. There is an advantage. Of course, the brake control can be performed without increasing the energy consumption. (2) It is possible to apply normal brake operation through the brake pedal even when the automatic brake device is operating, and even when the control system of the automatic brake device fails, normal brake operation through the brake pedal is possible. The brake operation performance of can be secured. (3) It can be installed simply by adding a brake actuator to an existing vehicle brake device equipped with a vacuum booster mechanism, and the existing device can be used to the maximum extent and can be installed easily at low cost.

According to the vehicle automatic brake device of the present invention as set forth in claim 2, in the structure of claim 1,
The brake pedal interlocking member is a shaft-shaped member arranged so as to penetrate through the center of the main body of the vacuum booster mechanism, and a pressing force is applied to the outer periphery of the brake pedal interlocking member toward the brake operating side. Since the pressure receiving surface for receiving the pressure is formed and the piston is provided with the pressing surface that is in contact with the pressure receiving surface and applies the pressing force to the brake operating side, the effect of the above (2), that is, It is possible to apply normal brake operation through the brake pedal even when the automatic brake device is operating, and it is possible to ensure normal brake operation performance through the brake pedal even when the control system of this automatic brake device fails. The effect of, can be obtained more reliably.

Further, according to the vehicle automatic brake device of the present invention as defined in claim 3, in the construction of claim 1 or 2, a cover member for covering the rear end of the case member of the vacuum booster mechanism body is mounted. Since the piston is internally provided in the closed space covered by the cover member and the rear end surface of the case member, the effect of the above (3), that is, the existing device is maximized. It becomes possible to more reliably obtain the effect of low cost and easy installation.

Further, according to the vehicle automatic brake device of the present invention described in claim 4, in the structure according to any one of claims 1 to 3, the hydraulic pressure adjusting mechanism includes a hydraulic power source and a hydraulic power source. An oil passage provided between the pressure chamber and a feed mode in which the oil is inserted in the middle of the oil passage to feed the hydraulic oil from the hydraulic source to the pressure chamber and the feed is stopped. Since it is composed of a switching valve having a stop mode and a pressure control valve for controlling the hydraulic pressure of the hydraulic oil fed through the switching valve, appropriate hydraulic pressure control can be performed, and Brake performance can be improved.

According to the vehicle automatic brake device of the present invention as defined in claim 5, in the structure of claim 4,
Since the hydraulic power source and part of the oil passage of the hydraulic pressure adjusting mechanism are used together with the vehicle hydraulic four-wheel steering device, the configuration of the hydraulic system is simplified, and a comprehensive automatic control of the vehicle is configured. In doing so, advantages such as downsizing of the device and reduction of installation cost can be obtained.

According to the vehicle automatic brake device of the present invention as defined in claim 6, in the structure of claim 4 or 5, the hydraulic pressure source and a part of the oil passage of the hydraulic pressure adjusting mechanism are not suitable for the vehicle automatic brake device. By being used in combination with the steering device, the structure of the hydraulic system is simplified, and in the case of constructing a comprehensive automatic control of the vehicle, advantages such as downsizing of the device and reduction of installation cost can be obtained.

Further, according to the vehicle automatic brake device of the present invention described in claim 7, in the structure described in any one of claims 4 to 6, the hydraulic oil drive sucks hydraulic oil from the tank. And a pressure accumulating means for accumulating the hydraulic oil from the hydraulic oil driving means, stable hydraulic source hydraulic pressure can be obtained, and hydraulic control can be performed with high precision. The performance of automatic braking can be improved.

[Brief description of drawings]

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

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

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

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

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

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

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

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

FIG. 11 is a schematic configuration diagram showing a vehicle automatic brake device using a conventional electric motor type actuator.

[Explanation of symbols]

1 master back (vacuum booster mechanism) 2 brake pedal 3 operating rod (brake pedal interlocking member) 3A flange part 3a pressure receiving surface 4 automatic brake actuator (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 13 Return spring 14 Piston 14A Flange portion 14a Pressing surface 15 Hydraulic chamber 16 Hydraulic adjustment mechanism 17 Return spring 18 Reservoir tank 19 Hydraulic circuit 20 Pump as hydraulic oil driving means (hydraulic power source) ) 21 flow dividing valve 22 check valve 23 accumulator (hydraulic pressure source) as pressure accumulating means 24 automatic brake switching valve 25 pressure control valve (pressure reducing valve) 24A valve body 24B return spring 24 C solenoid 25A valve body 25B return spring 25C solenoid 26 electronic control unit (ECU) 27 valve drive circuit 28 dash panel

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B62D 5/07 B 8510-3D (72) Inventor Takahiro Maemura 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Automobile Industry Co., Ltd. (72) Inventor Tadao Tanaka 5-33-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Industry Co., Ltd.

Claims (7)

[Claims] 1. A brake pedal interlocking member that moves forward and backward in conjunction with a brake pedal to operate a master cylinder, a diaphragm connected to the brake pedal interlocking member, and a negative pressure chamber and an atmospheric pressure chamber partitioned by the diaphragm. An on-off valve that interlocks with the brake pedal interlocking member to assist the depression force of the brake pedal when the brake pedal is depressed, and creates a pressure difference between the negative pressure chamber and the atmospheric pressure chamber. And an automatic brake actuator capable of operating the master cylinder by driving the brake pedal interlocking member to the brake operating side even if the brake pedal is not depressed. An actuator for pressing the brake pedal interlocking member toward the brake operating side. A piston installed so as to come into contact with the brake pedal interlocking member so as not to hinder the forward movement of the brake pedal interlocking member toward the brake operation side by depressing the brake pedal, and the brake operation side with respect to the piston. And a return spring for urging the piston in a direction opposite to the brake operating side. An automatic braking device for vehicles, characterized by: 2. The brake pedal interlocking member is a shaft-like member arranged so as to penetrate through the center of the main body of the vacuum booster mechanism, and the brake operating side is provided on the outer periphery of the brake pedal interlocking member. A pressure receiving surface for receiving a pressing force toward the piston is formed, and a pressing surface for contacting the pressure receiving surface and applying a pressing force to the brake operating side is formed on the piston. The automatic brake device for a vehicle according to 1. 3. A cover member is attached to cover a rear end of a case member of the vacuum booster mechanism body, and the piston is housed in a closed space covered by the cover member and a rear end surface of the case member. The automatic brake device for a vehicle according to claim 1 or 2, characterized in that. 4. The hydraulic pressure adjustment mechanism is provided with a hydraulic pressure source, an oil passage interposed between the hydraulic pressure source and the pressure chamber, and an intermediate portion of the oil passage, A switching valve having a feeding mode for feeding hydraulic oil to the pressure chamber and a stop mode for stopping feeding, and a pressure control valve for controlling the hydraulic pressure of the hydraulic fluid fed through the switching valve. The automatic brake device for a vehicle according to any one of claims 1 to 3, wherein the automatic brake device for a vehicle is provided. 5. The vehicular automatic brake system according to claim 4, wherein a part of the hydraulic power source and the oil passage of the hydraulic pressure adjusting mechanism is used together with a vehicular hydraulic four-wheel steering system. 6. The vehicle automatic brake device according to claim 4, wherein a part of the hydraulic power source and the oil passage of the hydraulic pressure adjusting mechanism is used together with the vehicle automatic steering device. 7. The hydraulic pressure source comprises hydraulic oil drive means for sucking hydraulic oil from a tank, and pressure accumulating means for storing the hydraulic oil from the hydraulic oil drive means. The automatic brake device for a vehicle according to any one of 4 to 6.