JPH07165059A - Automatic braking electronic control negative pressure type brake device - Google Patents

Abstract

PURPOSE:To obtain braking force by a drivers brake operation even when an automatic control system fails in an automatic braking electronic control load system brake device suitably used for an automatic brake vehicle. CONSTITUTION:An automatic braking electronic control load system brake device has a negative pressure chamber, an atmospheric pressure chamber and a control pressure chamber, and moreover has a negative pressure type brake booster 1 to regulate brake liquid pressure, and is provided with a negative pressure supply path 9b to supply the negative pressure from the negative pressure chamber to the control pressure chamber; an atmospheric pressure introducing path 9 to introduce atmospheric pressure to the control pressure chamber; electronic control valves 10, 11 which are severally insertedly attached in the negative pressure supply path 9b and the atmospheric pressure introducing path 9; a brake liquid pressure detecting means 8 to detect the brake liquid pressure; and a control means 12 to control the electronic control valves 10, 11. The control means 12 controls the electronic control valves 10, 11 on detection information sent from the brake liquid pressure detecting means 8 so as to obtain desired brake liquid pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled negative pressure type brake device for automatic braking, which is particularly suitable for use in an automatic braking vehicle.

[0002]

2. Description of the Related Art Conventionally, an automatic braking device for a vehicle has been developed that automatically brakes the vehicle, for example, to prevent the vehicle from running out of control. Such an automatic braking device requires a brake actuator. Become. As such a brake actuator, a hydraulic brake actuator used in an anti-lock brake system (hereinafter referred to as ABS) is generally used.

An example of a hydraulic brake actuator used for such an ABS is shown in FIG. Reference numeral 5 in the figure
Reference numeral 1 denotes a brake oil reservoir, reference numeral 52 denotes a master cylinder, and two oil passages 51a and 51b are arranged from the reservoir 51 to the master cylinder 52. Reference numeral 53 is a brake pedal, and reference numeral 54 is a pedal stroke sensor.
Thus, the depression amount of the brake pedal 53 is detected.
Further, reference numerals 55 and 56 are a pump motor and a motor rotation sensor, respectively, and the motor rotation sensor 56 detects the number of rotations of the pump motor 55.

A suction line 57 is provided as an oil passage between the pump motor 55 and the master cylinder 52. The suction line 57 is branched in the middle as shown in the figure, and one end of the suction line 57 has a first solenoid valve 58.
It is connected to the. An oil passage 59 is provided between the reservoir 51 and the pump motor 55.
One end of the oil passage 60 is connected in the middle of 9. The other end of the oil passage 60 is connected to the second solenoid valve 61.

In this example, the first solenoid valve 58
Is configured so that the valve is opened when the energized state is OFF, and the second solenoid valve 60 is in the energized state O.
In the FF state, the valve is configured to be closed, contrary to the first solenoid valve 58. When this hydraulic brake actuator is used for ABS, both the first and second solenoid valves 58, 60 are controlled by the ABS controller 62. in this case,
The ABS controller 62 sets a control signal for controlling the rotation speed of the pump motor 55 based on the information from the pedal stroke sensor 54, the motor rotation sensor 56, and the wheel speed sensor 63, and controls the first and second solenoid valves. A control signal for controlling the states of 58 and 60 is set.

On the other hand, when such a hydraulic brake actuator is used in an automatic braking device, a mechanism for driving the spool of the master cylinder 52 instead of the brake pedal is provided, and the mechanism and the first and first mechanisms are provided. A configuration is considered in which the second solenoid valves 58 and 60 are controlled by an automatic braking controller. In addition to those using the hydraulic brake actuator as described above,
JP-A-4-262957, JP-A-4-30306
No. 0, JP-A-4-310460, JP-A-4-310
Japanese Patent No. 339066 discloses a proposal using a brake booster for automatic braking.

[0007]

However, in the conventional automatic braking control device using the hydraulic brake actuator, during automatic braking, the hydraulic pressure of the brake is controlled by the actuator regardless of the depression amount of the brake pedal. , Even if the brake pedal is depressed when the actuator fails, the brake pressure may not be increased and braking may not be possible.

Therefore, even if the automatic braking system fails, it is necessary to provide means for surely performing the braking control according to the depression amount of the brake pedal by the driver's intention. Also, in the conventional automatic braking control that uses this hydraulic brake booster, the brake hydraulic pressure is directly controlled, so the braking feeling becomes unnatural, and noise generated from the pump of the hydraulic source causes the driver to feel unnatural. There is a problem of impairing the ability.

On the other hand, in the automatic braking device using the brake booster, it is easy to deal with a failure, and the brake fluid pressure is indirectly controlled, which is advantageous in terms of braking feeling, but more appropriately and more. I want to be able to perform automatic braking with a good feeling. The present invention has been devised in view of such a problem. Even when the control system for automatic braking fails, the driver can operate the brake pedal to obtain normal braking force, and the braking during automatic control can be performed. It is an object of the present invention to provide an electronically controlled negative pressure type brake device for automatic braking, which makes the driver feel natural without feeling uncomfortable.

[0010]

Therefore, the electronically controlled negative pressure type brake device for automatic braking of the present invention comprises a negative pressure chamber, an atmospheric pressure chamber, and a control pressure chamber for controlling the pressure of the atmospheric pressure chamber,
A negative pressure brake booster capable of adjusting a brake fluid pressure according to the pressure balance between the negative pressure chamber and the atmospheric pressure chamber is provided, and a negative pressure supply capable of supplying a negative pressure from the negative pressure chamber to the control pressure chamber. A passage, an atmospheric pressure introducing passage capable of introducing atmospheric pressure into the control pressure chamber, an electronic control valve interposed in each of the negative pressure supplying passage and the atmospheric pressure introducing passage, and adjusted by the negative pressure brake booster. Brake fluid pressure detection means for detecting the brake fluid pressure and control means for controlling the electronic control valve are provided, and the control means is configured to control the desired brake fluid based on the detection information from the brake fluid pressure detection means. It is characterized in that it is configured to control the electronically controlled valve so as to obtain a pressure.

[0011]

In the above-described electronically controlled negative pressure type brake device for automatic braking of the present invention, when the brake hydraulic pressure generated by the negative pressure type brake booster is detected by the brake hydraulic pressure detecting means, the information of the brake hydraulic pressure is sent to the control means. Transmitted.
Then, the control means controls the electronic control valves respectively provided in the negative pressure supply passage and the atmospheric pressure introduction passage so that a desired brake fluid pressure can be obtained based on the detection information from the brake fluid pressure detection means. . As a result, the pressure balance between the negative pressure chamber and the atmospheric pressure chamber of the negative pressure brake booster is adjusted, the brake fluid pressure is controlled, and automatic braking is performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronically controlled negative pressure type brake device for automatic braking according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration, and FIG. 2 is a schematic diagram showing its functional configuration. FIG. 3, FIG. 3 is a schematic cross-sectional view showing the structure of the main part, FIG. 4 is a flow chart for explaining the operation, and FIG. 5 is a graph for explaining the action.

First, as shown in FIG. 1, in the electronically controlled negative pressure type brake device for automatic braking of the present invention, an electronically controlled negative pressure type brake booster (masterback) widely used as a brake booster in vehicles such as automobiles. ) 1 and an atmospheric pressure introducing passage 9 for introducing atmospheric pressure into the brake booster 1.
And a negative pressure supply passage 9b for supplying a negative pressure from the brake booster 1 to a control pressure chamber 5 which will be described later, and the first and second electronic control valves interposed in the atmospheric pressure introduction passage 9 and the negative pressure supply passage 9b. Second solenoid valves 10 and 11, a hydraulic pressure sensor 8 as a brake hydraulic pressure detection means, and a controller 12 as a control means for controlling the first and second solenoid valves 10 and 11 are provided.

First, the brake booster 1 will be described in detail. Normally, the brake booster 1 increases the brake fluid pressure by utilizing the negative pressure due to the intake pressure of the engine when the brake pedal 2 is depressed. As shown in FIG. 3, the push rod 6 and the operating rod are used. 1
5 is provided, and the pushing force of the driver is transmitted to the push rod 6 via the operating rod 15 and the brake pedal 2. The push rod 6 is connected to a master cylinder (not shown), and the master cylinder is configured to generate a brake fluid pressure according to the amount of movement of the push rod 6.

The brake fluid pressure is supplied to the wheel cylinder that holds the brake disc of each wheel through the oil passage 7 shown in FIG. Further, the brake booster 1 has a diaphragm 1 inside.
6 and a bellows 17 divide the chamber into three chambers, a negative pressure chamber 3, an atmospheric pressure chamber 4, and a control pressure chamber 5. The negative pressure chamber 3 has an engine negative pressure inlet 3 for taking in engine negative pressure.
a and a negative pressure supply port 3b for supplying the engine negative pressure to the control pressure chamber 5 are provided, and the control pressure chamber 5 is provided with a control pressure intake port 5a.

The engine negative pressure intake port 3a is connected to a surge tank of an engine (not shown), and the negative pressure supply port 3b is connected to an air cleaner of the vehicle through an atmospheric pressure introducing passage 9. Further, the engine negative pressure to the negative pressure supply port 3b may be directly supplied from a negative pressure source (surge tank or the like). Further, as described above, both the engine negative pressure intake port 3a and the negative pressure supply port 3b are provided in the negative pressure chamber 3, so the engine negative pressure intake port 3a and the negative pressure supply port 3b are located in the negative pressure chamber 3. Communicate within.

The control pressure chamber 5 is provided with a return spring 14 for urging the push rod 6 to the right side (brake pedal side). And normally, the negative pressure chamber 3
Is in a negative pressure state due to the intake air from the surge tank of the engine, and the atmospheric pressure chamber 4 is kept in a state of not communicating with the atmosphere by the urging force of the return spring 14.

When the driver depresses the pedal 2, the push rod 6 moves to the left against the urging force of the return spring 14, and the atmosphere introduction port (not shown) provided in the atmospheric pressure chamber 4 opens. The atmospheric pressure chamber 4 communicates with the atmosphere. As a result, due to the pressure difference between the negative pressure chamber 3 and the atmospheric pressure chamber 4, a force acts on the push rod 6 in the leftward direction in the drawing. This force acts on a master cylinder (not shown) to boost the brake fluid pressure.

As a result, even if the brake pedal force is small, a sufficient brake fluid pressure is generated and the braking force can be obtained. In this device, the brake pedal 2
In the state where (or the operating rod 15) is not pushed, the control pressure chamber 5 and the atmospheric pressure chamber 4 are in communication with each other, and even if the brake pedal 2 is not depressed, the push rod 6 depends on the pressure of the control pressure chamber 5. It is designed to be driven. For example, when the atmospheric pressure is applied to the control pressure chamber 5 as the control pressure, the atmosphere is introduced into the atmospheric pressure chamber 4 and the push rod 6 is driven leftward in the figure, and then the control pressure is applied to the control pressure chamber 5. If a negative pressure is applied as, the pressure in the atmospheric pressure chamber 4 is reduced and the push rod 6 is driven to the right in the figure. By adjusting the control pressure in this way, the same brake fluid pressure control as the braking force control by the brake pedal 2 can be automatically performed.

When the brake pedal 2 is depressed, the control pressure chamber 5 and the atmospheric pressure chamber 4 are shut off from each other. Returning to FIG. 1 again and explaining, the atmospheric pressure introducing passage 9
Of the solenoid valves 10 and 11 as electronic control valves provided on the negative pressure supply passage 9b, the first solenoid valve on the left side in FIG.
Solenoid valve 10 is off (ie,
The valve is always open when energized), while the second solenoid valve 11 on the right side in FIG. 1 is always closed when the switch is OFF.

Further, a control pressure introducing passage 9a is branched from between the solenoid valves 10 and 11 on the atmosphere introducing passage 9 and the negative pressure supplying passage 9b, and the control pressure introducing passage 9a is connected to the control pressure inlet. 5a. Further, the hydraulic pressure sensor 8 provided in the oil passage 7 detects the adjusted brake hydraulic pressure through the brake booster 1. Further, the controller (ECU) 12 is provided with the hydraulic pressure sensor 8
The information from will be input.

Further, the brake pedal 2 is provided with a pedal switch 13. This pedal switch 13
Is attached to the surface of the brake pedal 2 so that the driver's brake pedal force can be detected. That is, when the driver steps on the brake, the pedal switch 13 is configured to output a voltage proportional to the pedaling force, and this voltage information is transmitted to the controller 12.

Since the pedal switch 13 does not detect the pedal stroke of the brake pedal 2 but directly detects the force with which the driver depresses the brake pedal 2, the magnitude of this force (that is, the magnitude of the detected voltage). Therefore, the intention information for the driver to brake can be taken into the controller 12. In addition, this controller 12
The target hydraulic pressure information is also input to. The target hydraulic pressure is the most desirable brake hydraulic pressure calculated from the current running state of the vehicle, and is calculated by a not-shown arithmetic unit or the like.

In the controller 12, the target hydraulic pressure, information from the hydraulic pressure sensor 8 and the pedal switch 13 are used.
Solenoid valves 10, 1 based on voltage information from
The control amount for controlling the open / closed state of No. 1 is set. As shown in Table 1, the controller 12 controls the device in four modes including a pressure increasing mode, a pressure reducing mode, a holding mode, and a stop mode, depending on the control mode of the open / close state of the solenoid valves 10 and 11. There is.

[0025]

[Table 1]

That is, the value of the hydraulic pressure deviation ΔP, which is the difference between the target hydraulic pressure and the brake hydraulic pressure detected by the hydraulic pressure sensor 8, is calculated, and the controller 12 determines that automatic braking is required. For example, the control mode is set from a map as shown in FIG.

Then, the open / closed states of the solenoid valves 10 and 11 are controlled based on the control signal of the set control mode to control the state of the negative pressure type brake booster,
A desired braking force is obtained. The brake fluid pressure at this time is also monitored by the fluid pressure sensor 8 and feedback-controlled. Here, the control mode of the solenoid valves 10 and 11 will be described. For example, when the hydraulic pressure deviation ΔP becomes equal to or more than a first predetermined value (0.1 in this example), the pressure increase duty control mode is set. The pressure reduction duty control mode is set when the hydraulic pressure deviation ΔP becomes equal to or less than the second predetermined value (−0.1 in this example).

Further, the hydraulic pressure deviation ΔP has a first predetermined value and a second predetermined value.
The holding mode is set when the value is within the predetermined value of. That is, the range of this hydraulic pressure deviation | ΔP | ≦ 0.1 is a dead zone, and the control is stabilized. Furthermore, when there is no need for automatic braking, the stop mode is set. The pressure-increasing duty control mode is a mode for increasing the brake hydraulic pressure, and the pressure-decreasing duty control mode is a mode for decreasing the brake hydraulic pressure, on the contrary, in the pressure-increasing and pressure-decreasing duty control modes. The pressure increasing mode and the holding mode or the pressure reducing mode and the holding mode are switched according to the set duty ratio. Further, the holding mode is a mode in which the brake fluid pressure is kept constant without changing, and the stop mode is a mode in which the adjustment of the brake fluid pressure by automatic braking is stopped.

When the controller 12 sets the brake fluid pressure control to the pressure increasing mode, as shown in Table 1, both the solenoid valves 10 and 11 are switched to the switch O.
Controlled by N. As a result, the atmospheric pressure from the atmospheric pressure introducing passage 9 to the controlling pressure chamber 5 is taken into the controlling pressure chamber 5 from the controlling pressure inlet 5a. Then, the atmospheric pressure is introduced from the control pressure chamber 5 into the atmospheric pressure chamber 4, and the atmospheric pressure chamber 4 and the negative pressure chamber 3
The push rod 6 receives a force in the leftward direction due to the pressure difference between and, and the brake fluid pressure is increased.

When the brake fluid pressure control is set to the pressure reducing mode, the solenoid valves 10 and 11 are both controlled to be turned off. At this time, since the second solenoid valve 11 is driven to the closed state, there is no inflow of atmospheric pressure from the atmospheric pressure introducing passage 9, and the negative pressure supply port 3b is the first
Through the solenoid valve 10 of 1. As a result, the atmospheric pressure in the control pressure chamber 5 is reduced in the same manner as in the negative pressure chamber 3 and also in the atmospheric pressure chamber 4, and the pressure difference between the negative pressure chamber 3 and the atmospheric pressure chamber 4 is reduced, and The control negative pressure type brake booster 1 becomes the same as a normal brake booster, and unless the pedal force acts on the brake pedal 2, the push rod 6 is pressed rightward in FIG. The hydraulic pressure does not rise.

Further, in the holding mode, the first solenoid valve 10 is controlled to be switched on and the second solenoid valve 11 is controlled to be switched off. In this case, the second solenoid valve 11 is closed, so that atmospheric pressure is not introduced from the atmosphere introduction path 9. As a result, the atmosphere does not flow into the control pressure chamber 5. Further, by closing the first solenoid valve 10 as well, the flow of air between the negative pressure supply port 3b and the control pressure intake port 5a is shut off, and the control pressure chamber 5 becomes a sealed chamber.

Therefore, the pressure in the atmospheric pressure chamber 4 becomes constant, the diaphragm 16 does not move, and the push rod 6
The position of is fixed. As a result, the brake fluid pressure is kept constant. The stop mode is a mode set when automatic braking is not performed, and is a mode in which the braking force is controlled by the driver's braking operation. Therefore, it suffices to set the electronically controlled negative pressure type brake booster 1 so as to operate in the same manner as a normal brake booster.
Both 0 and 11 are controlled to be turned off.

The stop mode is set to the ignition OF.
This is also the open / closed state of the solenoid valves 10 and 11 in the case of F. The pressure increase duty control mode, the pressure decrease duty control mode, the holding mode, and the stop mode are set, for example, every control cycle of 60 msec, and in the case of the duty control mode, in the controller 12 every predetermined time (for example, every 5 msec). ) Is applied with a pressure increasing mode or a pressure reducing mode, and a drive signal is transmitted to each solenoid valve 10, 11.

That is, in the pressure increase duty control mode and the pressure decrease duty control mode, as shown in FIG. 5, duty control is performed according to the magnitude of the value of the hydraulic pressure deviation ΔP. An example of the duty ratio is:
When the hydraulic pressure deviation | ΔP | is 0.1 to 0.5 [MPa], the duty ratio is 25%, and the hydraulic pressure deviation | ΔP | is 0.5 to 1.0.
When [MPa], the duty ratio is 33.3% and the hydraulic pressure deviation is |
When ΔP | is 1.0 [MPa] or more, the duty ratio is 50
It is set to%.

Further, the hydraulic pressure deviation | ΔP | is 0 to 0.1 [M
Pa], the duty ratio is 0%, that is, the holding mode is set. Then, as shown in the graph of FIG. 5, in the pressure increase duty control mode or the pressure decrease duty control mode, the hydraulic pressure control is performed at the ratio of the above-mentioned duty ratio in one control cycle, and the rest of the control cycle is held. The solenoid valves 10 and 11 are controlled in the mode.

That is, when the hydraulic pressure deviation | ΔP | is comparatively small, the holding mode with the duty ratio of 0% is set in order to hold the brake hydraulic pressure at that time, and when this hydraulic pressure deviation | ΔP | becomes large, The pressure increasing mode or the pressure reducing mode is set with a duty ratio according to the value. of course,
At this time, the pressure increase mode is set when the hydraulic pressure deviation ΔP> 0, and the pressure reducing mode is set when the hydraulic pressure deviation ΔP <0.

When the controller 12 determines based on the voltage information from the pedal switch 13 that the driver has lightly placed his / her foot on the brake pedal 2, the automatic braking is stopped (that is, the stop mode is set. ), The driver's intention is to give priority to braking. By the way, the air from the first and second solenoid valves 10 and 11 is not directly introduced into the atmospheric pressure chamber 4, but the brake booster 1
The reason why the control pressure chamber 5 is provided inside and the atmospheric pressure is introduced into the control pressure chamber 5 is as follows.

That is, in order to prevent the driver from controlling the automatic braking while the brake is being operated, the control pressure chamber 5 is normally closed while the brake pedal 2 is being pressed (driver operation). Must be operated (atmosphere is introduced from the operating rod part). Therefore, if an air passage from the solenoid valves 10 and 11 is directly provided in the atmospheric pressure chamber 4, a new valve mechanism is required and it becomes difficult to mechanically shut off the valve mechanism.

On the other hand, the normal brake booster has a structure in which the atmospheric pressure chamber 4 and the negative pressure chamber 3 are mechanically cut off by pushing the brake pedal 2, so that the control pressure in the negative pressure chamber 3 is reduced. By providing the chamber 5, the control pressure chamber 5 and the atmospheric pressure chamber 4 can be easily shut off. In addition, it may be difficult to provide an air passage in the atmospheric pressure chamber 4 on the vehicle body side due to the structure of the mounting position of the brake booster 1.

Since the electronically controlled negative pressure type brake device for automatic braking as one embodiment of the present invention is configured as described above, when automatic braking is not performed, the driver's brake is applied in the same manner as a normal braking device. The brake fluid pressure is increased or decreased according to the amount of depression of the pedal 2. On the other hand, the operation for automatic braking will be described with reference to the flowchart shown in FIG. This control is performed every 60 msec. First, in step S1, one control cycle (60
msec) is determined.

If 60 msec has elapsed, the process proceeds to step S2, the information from the hydraulic pressure sensor 8 or the pedal switch 13 which is converted into a digital signal from the analog signal is fetched, and the process proceeds to step S3. If 60 msec has not elapsed, the process returns to step S1 and this routine is repeated until one control cycle ends. Then, in step S3, the brake fluid pressure deviation ΔP is calculated by the following equation (1) based on the information fetched in step S2.

Hydraulic pressure deviation ΔP = Target hydraulic pressure-Current hydraulic pressure (1) Next, in step S4, it is determined whether or not automatic braking is to be performed. If automatic braking is not to be performed, step S1 is performed.
The process proceeds to 0 and the stop mode is set. If it is determined that automatic braking is to be performed, the process proceeds to step S5, and the equation (1) is used.
Whether or not the magnitude of the hydraulic pressure deviation ΔP obtained in step 3 is larger than a predetermined value (0.1 in this example) is determined by the following equation (2).

| ΔP |> 0.1 (2) Then, if | ΔP | is larger than 0.1, step S
Go to 6. If | ΔP | is 0.1 or less, the process proceeds to step S11 to set the holding mode. Next, in step S6, it is determined whether ΔP is positive or negative. When ΔP is a positive value, the process proceeds to step S7, and the pressure increasing duty control mode is set. If ΔP is a negative value, step S12
Then, the pressure reducing duty control mode is set.

Then, steps S7, S10, S11,
In any of S12, the solenoid valves 10, 1
When the control mode 1 is set, the process then proceeds to step S8, the duty ratio is set, and the control signal for driving the solenoid valves 10 and 11 is set in step S9. After that, the process returns to step S1 to repeat this routine.

In this way, the solenoid valve 10,
When the control mode 11 is set, the control pressure chamber 5 of the brake booster 1 is adjusted from the negative pressure state to the atmospheric pressure state. Then, by this, the negative pressure chamber 3 and the atmospheric pressure chamber 4
The position of the diaphragm 16 moves due to the balance of the pressures of and, the operating rod 15 and the push rod 6 are driven, and the brake fluid pressure from the master cylinder (not shown) is adjusted to a desired value.

In this device, since the hydraulic pressure control of the brake during automatic braking corresponds to the depression amount of the brake pedal 2, normal braking of the driver is performed even when the automatic braking system fails. You can Further, in the present device, the brake rod pressure is feedback-controlled by adjusting the push rod 6 by controlling the pressure of the control pressure chamber 5, so that the braking feeling can be made natural and comfortable. Of.

Further, by mounting the present device on a vehicle equipped with a safety inter-vehicle distance control system or the like which can detect when the vehicle approaches the front vehicle too much or approaches an obstacle, for example, For automatic braking to maintain a safe inter-vehicle distance from the vehicle in front, or to increase the braking pressure to give a large braking force to the vehicle when the driver's brake operation force is insufficient and does not rise to the desired brake fluid pressure. It is possible to perform automatic braking and the like with a natural feeling.

Further, the brake switch 13 provided on the brake pedal 2 does not respond to the depression stroke of the brake pedal 2 but generates a voltage in proportion to the pedal depression force (pressure) of the driver. The force with which the pedal 2 is depressed can be reliably detected. Therefore, by setting the control for stopping the automatic braking when the driver puts his / her foot on the brake pedal 2 based on the information of the brake switch 13,
It is possible to reliably give priority to the braking intention of the driver over the automatic braking.

[0049]

As described above in detail, according to the electronically controlled negative pressure type brake device for automatic braking of the present invention, the negative pressure chamber, the atmospheric pressure chamber, and the control pressure chamber for controlling the pressure of the atmospheric pressure chamber are provided. A negative pressure type brake booster capable of adjusting a brake fluid pressure according to the pressure balance between the negative pressure chamber and the atmospheric pressure chamber is provided, and a negative pressure capable of supplying a negative pressure from the negative pressure chamber to the control pressure chamber. A pressure supply path, an atmospheric pressure introduction path capable of introducing atmospheric pressure into the control pressure chamber, an electronic control valve provided in each of the negative pressure supply path and the atmospheric pressure introduction path, and the negative pressure type brake booster. Brake fluid pressure detection means for detecting the adjusted brake fluid pressure and control means for controlling the electronic control valve are provided, and the control means is capable of obtaining desired brake fluid pressure based on detection information from the brake fluid pressure detection means. The electronic control valve is controlled so that the brake fluid pressure is obtained. Since configured to, even automatic braking system is a case of failure can be performed normal braking of the driver.

Further, since the hydraulic pressure of the brake is feedback-controlled by controlling the pressure of the air in the control pressure chamber, it is possible to make the braking feeling natural and comfortable.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall configuration of an electronically controlled negative pressure type brake device for automatic braking as an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a functional configuration of an electronically controlled negative pressure type brake device for automatic braking as one embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing a main configuration of an electronically controlled negative pressure type brake device for automatic braking as an embodiment of the present invention.

FIG. 4 is a flow chart for explaining the operation of the electronically controlled negative pressure type brake device for automatic braking as one embodiment of the present invention.

FIG. 5 is a graph for explaining the operation of the electronically controlled negative pressure type brake device for automatic braking as one embodiment of the present invention.

FIG. 6 is a schematic hydraulic circuit diagram showing the overall configuration of a conventional ABS.

[Explanation of symbols]

 1 Negative pressure type brake booster 2 Brake pedal 3 Negative pressure chamber 3a Engine negative pressure intake port 3b Negative pressure supply port 4 Atmospheric pressure chamber 5 Control pressure chamber 5a Control pressure intake port 6 Push rod 7 Oil passage 8 As a brake fluid pressure detection means Liquid pressure sensor 9 Atmospheric pressure introduction path 9a Control pressure introduction path 9b Negative pressure supply path 10 First solenoid valve as electronic control valve 11 Second solenoid valve as electronic control valve 12 Controller as control means 13 Pedal switch 14 Return Spring 15 Operating rod 16 Diaphragm 17 Bellows 51 Reservoirs 51a, 51b Oil passage 52 Master cylinder 53 Brake pedal 54 Pedal stroke sensor 55 Pump motor 56 Motor rotation sensor 57 Suction line 58 First solenoid valve 59, 60 Oil 61 second solenoid valve 62 ABS controller 63 wheel speed sensor 64 the wheel cylinder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Aono 5-3-8, Shiba, Minato-ku, Tokyo Within Mitsubishi Motors Corporation (72) Inventor Kiichi Yamada 5-33-8, Shiba, Minato-ku, Tokyo Mitsubishi Automotive Industry Co., Ltd.

Claims (1)

[Claims] 1. A negative pressure chamber, an atmospheric pressure chamber, and a control pressure chamber for controlling the pressure of the atmospheric pressure chamber, and the brake fluid pressure is adjusted according to the pressure balance between the negative pressure chamber and the atmospheric pressure chamber. A negative pressure type brake booster capable of supplying a negative pressure from the negative pressure chamber to the control pressure chamber, and an atmospheric pressure introducing route capable of introducing atmospheric pressure into the control pressure chamber,
An electronic control valve provided in each of the negative pressure supply path and the atmospheric pressure introduction path, and a brake fluid pressure detecting means for detecting a brake fluid pressure adjusted by the negative pressure type brake booster,
Control means for controlling the electronic control valve is provided, and the control means controls the electronic control valve so that a desired brake fluid pressure is obtained based on the detection information from the brake fluid pressure detection means. An electronically controlled negative pressure type brake device for automatic braking, characterized in that