JPH0256263B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake force control system for a vehicle that electrically controls the brake force of a vehicle such as an automobile, and links the control command to an accelerator pedal, thereby simplifying vehicle driving operation. .

Driving an automobile is basically performed by operating an accelerator, a brake, and a transmission. In recent years, transmission operations have become automatic and shift changes are no longer necessary, but there is still no system that makes it easier to operate the accelerator. It was also necessary to press the brake and pedal as necessary. Further, in the conventional braking force of a vehicle, the force of a brake pedal pressed by a person is multiplied by a master bag as shown in FIG. 1, and this force presses a hydraulic cylinder. As a result, a brake force is generated by the hydraulic pressure of the hydraulic cylinder operating the brake mechanism.

FIG. 1 is a sectional view showing the master bag described above. In the figure, two chambers A on the left and right of the power piston 12 are partitioned by a diaphragm 11,
B is normally maintained at the negative pressure that occurs in the engine's intake manifold. That is, when there is no braking force, chambers A and B are connected by passage C, so both chambers A and B are in a negative pressure state, and the power piston 12 is fixed to the right side by the spring force. On the other hand, when a brake force is applied, the force of a brake pedal (not shown) is applied to the push rod 13 as a force in the direction of arrow D. As a result, the passage C is closed by the control valve 14, and the atmosphere is
Since the air is introduced into chamber B from the direction shown in FIG. As a result, the push rod 15 applies a force to the hydraulic cylinder (master cylinder), and the reaction disk 16 transmits a reaction force to the valve plunger 17. Therefore, in order to generate braking force electrically, a separate actuator can be installed instead of a human being to drive the brake pedal, but the maximum pedal force is 20
The disadvantage was that the brake control mechanism was large and impractical.

This invention was made in view of the above points,
Electrically controls the braking force of vehicles such as cars,
It is an object of the present invention to provide a brake force control system for a vehicle that links the control command to an accelerator pedal and facilitates vehicle driving operation.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, FIG. 2 shows the structure of a master bag used in the vehicle brake force control system according to the present invention, which has a different structure from the conventional master bag shown in FIG. 1, and FIG. 2 is a sectional view thereof. It is. Components in FIG. 2 that have the same names as those shown in FIG. 1 are given the same numbers. Chamber B (one chamber) and chamber A (the other chamber) in the master bag are connected by a pipe 22 in which a first electromagnetic valve is interposed. Further, the manifold negative pressure sent from the engine boost (not shown) is sent directly to the A chamber, and is also sent to the B chamber via the second solenoid valve 23. Further, the atmosphere is sent into the B chamber via the third solenoid valve 24. The difference in atmospheric pressure between chambers B and A, that is, the differential pressure, is detected by the differential pressure sensor 25.

FIG. 3 is a diagram showing the overall configuration of the vehicle brake force control system according to the present invention. In the figure, 31 is a master bag, which has the structure shown in FIG. Further, 32 is a master cylinder. The first solenoid valve 21, the second solenoid valve 23, the third solenoid valve 24, and the differential pressure sensor 25
is the same as that shown in FIG. By the way, 33 is a brake pedal, which has a pedal force switch 33a inside. When the brake pedal 33 is depressed, the brake switch 33a is closed and a signal a is output.
As a result, an H level signal is output to the control circuit 34. The detailed configuration of this control circuit 34 will be described later using FIG. 5. Further, a differential pressure signal b is input from the differential pressure sensor 25 to the control circuit 34 . 35 is an accelerator pedal, and this accelerator pedal 35 is connected to the box 3 via a cable 36 that operates according to the degree to which the accelerator pedal 35 is depressed.
Connected to 7. A pedal position sensor 35a detects the degree to which the accelerator pedal 35 is depressed, and its detection signal c is output to the control circuit 34. Further, 38 is a constant speed travel actuator, to which manifold negative pressure is sent from an engine boost (not shown). This constant speed traveling actuator 38 is operated by the driver using the accelerator pedal 35.
This applies a constant tension to the throttle cable 39 even if the throttle cable 39 is not pressed. Moreover, in the box 37, the cable 37a and the cable 37b are connected to the rod 37c.
The degree to which the accelerator pedal 35 is pressed or the constant speed traveling actuator 3
The rod 37c moves from side to side in response to the tensioning force applied to the cable 37b from 8. When the rod 37c moves to the left within the box, a reaction force is applied by the spring 40. Further, 42 is a notch device, in which a plate 43 rotates as the cable 41 moves from side to side, and a lever 44 rotates as the plate 43 rotates.
The tip of the protrusion 4 slides on the outer periphery of the plate 43 and is provided at a position corresponding to the neutral area.
By exceeding 5 to the power of 5, it is possible to judge the changeover between the brake region and the accelerator region. Further, 46 is a steering switch, which prevents the brake from being applied if this switch is pressed when moving from the neutral region to the brake region. The operation signal d of the steering switch 46 is sent to the control circuit 34. Further, 47 is a constant speed travel switch lever, and when this switch is operated, the operation signal e is output to the control circuit 34, and the constant speed travel actuator 38 is actuated by the manifold negative pressure, and the throttle cable 39 is automatically operated. be done. And 48
is an indicator that displays the brake area, neutral area, and accelerator area using red, orange, and yellow lamps, and the display is controlled by the signal f from the control circuit 34. In addition, the control circuit 34
outputs signals g to i to the first solenoid valve 21, the second solenoid valve 23, and the third solenoid valve 24, and performs on/off control of the solenoid valves.

Next, FIG. 4 shows a side view of the accelerator pedal 35, and there are three areas depending on the degree to which the accelerator pedal 35 is depressed: a brake area, a neutral area, and an accelerator area.

Next, FIG. 5 is a diagram showing a detailed configuration of the control circuit 34 shown in FIG. 3. In the figure, a detection signal c proportional to the depression (stroke S) of the accelerator pedal 35 detected by the pedal position sensor 35a is input to an amplifier circuit 51. This amplifier circuit 51 outputs a voltage proportional to the stroke S, and as shown in the graph above the block, when the stroke S is A or more, it is in the accelerator region, and when the stroke S is B or more and less than A, it is in the neutral region. When the stroke S is less than or equal to B, a voltage in the brake region is output. This amplifier circuit 51 generates a voltage proportional to the stroke S as described above.
a comparator 52, a second comparator 53,
The signals are output to the level conversion circuit 54, respectively. The first comparator 52 compares and detects whether the voltage input from the amplifier circuit 51 is in the accelerator region, and generates a high level signal when the stroke S is equal to or greater than A. is output to the indicator 48 and NOR circuit 55. That is, this signal is used to light up the blue lamp in the indicator 48 that indicates the accelerator area. The second comparator 53 compares and detects whether the voltage input from the amplifier circuit 51 is in the brake region, and if the stroke S is below B, a high level signal is generated. These signals are output to the NOR circuit 55 and the inverter 56, respectively. The above Noah circuit 5
The output signal No. 5 is input to the indicator 48 and used to light an orange lamp indicating the neutral region. However, the inverter 5
The output signal of 6 is input to an AND circuit 57 via a time constant circuit consisting of a resistor _R1 and a capacitor C.
Further, the output signal of the inverter 56 is inputted to the AND circuit 57 and the NAND circuit 59 via the inverter 58, respectively. Further, the signal d from the steering switch 46 and the signal e from the constant speed travel switch lever 47 are inputted to the AND circuit 57 via the inverter 60. The output signal of the AND circuit 57 is input to the S terminal of the SR type flip-flop 61. Also,
The signal a from the pedal force switch 33a is input to the NAND circuit 59 via the inverter 62. The output signal of the NAND circuit 59 is input to the R terminal of the flip-flop 61. moreover,
The Q output of the flip-flop 61 is connected to the indicator 48, the first solenoid valve 21, and the AND circuit 6.
3 and 64, respectively. The signal input to the indicator 48 is used to light up a red lamp indicating the braking area. The output of the level conversion circuit 54 is the fixed contact 65 of the relay 65.
connected to a. Furthermore, the level conversion circuit 5
The output of No. 4 is connected to a fixed contact 62b of a relay 65 via a low-speed level conversion circuit 56. Thus, a pulse proportional to the speed of the vehicle outputted from the vehicle speed sensor 66 is inputted to the FV conversion circuit 67. This FV conversion circuit 67 outputs a voltage proportional to the vehicle speed to a third comparator 68. This third comparator 68 outputs a signal that becomes high level to the relay 65 when the vehicle speed exceeds 12 km/h. In addition, the output of the relay 65 is a differential pressure voltage.
It is input to the window comparator 69 as _V1 . Further, the voltage V ₂ from the differential pressure sensor 25 is input to the window comparator 69 . Also,
The output V ₃ of the window comparator 69 is sent to the AND circuit 63 via the inverter 63a, and the output V ₄ is sent to the AND circuit 6 via the inverter 64a.
4 is input. The output of the AND circuit 63 is output to the second solenoid valve 23, and the output of the AND circuit 64 is output to the third solenoid valve 24.

Next, the operation of the present invention configured as described above will be explained. First, in order to clarify the characteristics of the operation of the present application, we will explain the case where the car is started and the accelerator pedal 35 moves from the accelerator area to the brake area as shown in FIG. 4 as an example. . When the accelerator pedal 35 is in the accelerator region, its position is detected by the pedal position sensor 35a, and the signal c is sent to the control circuit 34, and then to the amplifier circuit 51 shown in FIG. 5 within the control circuit 34. This amplifier circuit 51 generates a voltage proportional to the stroke S of the accelerator pedal 35. Here, since the accelerator pedal 35 is in the accelerator region, the first comparator 52 outputs a high level signal and the second comparator 53 outputs a low level signal. As a result, the output of the first comparator 52 becomes high level, and the indicator 4
The blue lamp inside 8 lights up, informing you that the car is currently in the accelerator state. Furthermore, since the output of the second comparator 53 is at a low level, the logic condition of the AND circuit 57 does not hold, so the flip-flop 61 is in a reset state. Therefore, the first solenoid valve 21, the second solenoid valve 23, and the third solenoid valve to which the Q output of the flip-flop 61 is input
The relay coil of the solenoid valve 24 is not energized.
Therefore, only the first solenoid valve 21, which is normally open, is open, and the solenoid valve (negative pressure) 23,
The solenoid valve (atmosphere) 24 is closed. Therefore, the pressures in chambers A and B shown in FIG. 2 are maintained at negative pressure. In this case, when the brake pedal 33 is depressed, the braking force is boosted by the master back 31 and transmitted to the master cylinder 32 to apply the brake, as in the conventional case.

Next, the stroke S of the accelerator pedal 35 is made smaller, and when the accelerator pedal 35 enters the neutral region, the first and second comparators 5
The outputs of 2 and 53 are both low level. As a result, the output of the NOR circuit 55 becomes high level, and the orange lamp in the indicator 48 indicating the neutral state lights up. Even in this state, the flip-flop 61 is in the reset state, so the states of the first solenoid valve 21, second solenoid valve 23, and third solenoid valve 24 are the same as in the accelerator region. Therefore, in this case, when the brake pedal 33 is depressed, the braking force is boosted by the master bag 31 and transmitted to the master cylinder 32 to apply the brake, as in the conventional case.

Next, as the stroke S of the accelerator pedal 35 is further reduced, the accelerator pedal 35 enters the braking region, and only the output of the second comparator 53 becomes a high level state. As a result, the logic condition of the AND circuit 57 is satisfied, and the flip-flop 6
1 is set. As a result, the relay coil of the main solenoid valve 21 is energized and the valve is closed. As a result, A of the master back 31 shown in FIG.
The chamber and B chamber are separated. The pressure in the B chamber thus separated is controlled by the negative pressure sucked in through the second solenoid valve 23 and the third solenoid valve 24 or by atmospheric air. Hereinafter, a method of controlling the second solenoid valve 23 and the third solenoid valve 24 will be described. Accelerator pedal 35 output from the amplifier circuit 51
A voltage proportional to the stroke S is input to the level conversion circuit 54, and a differential pressure voltage inversely proportional to the stroke S is output. The differential voltage output from the level conversion circuit 54 is input to the window comparator 69 via the relay 65 as a signal V ₁ . Also, a signal indicating the differential pressure between chamber B and chamber A of master bag 31 output from differential pressure sensor 25.
V ₂ is input to the window comparator 69.
Immediately after the accelerator pedal 35 moves from the neutral region to the brake region, the pressures in chambers B and A are equal, so V ₂ =0. Immediately after the accelerator pedal 35 shifts from the neutral region to the brake region, the voltage V ₁ inputted from the level conversion circuit 54 is 0, and the accelerator pedal 35
5, the voltage V ₁ increases as the distance between them increases. Therefore, as shown in FIG. 6, immediately after the accelerator pedal 35 moves from the neutral region to the brake region, the signals V ₃ and V output from the window comparator 69 are between V ₁ −V ₅ <V ₂ <V ₁ . _Four
Both are at a high level. As a result, the gates of AND circuits 63 and 64 remain closed,
Both the second solenoid valve 23 and the third solenoid valve 24 remain turned off. Thereafter, as the accelerator pedal 35 is further released, the voltage V ₁ output from the level conversion circuit 54 increases, and V ₂ <V ₁ <V ₅ . In this state, as shown in FIG. 6, the window comparator 69
The signal V ₃ outputted from the terminal is at a high level, and the signal V ₄ is at a low level. As a result, the logic of the AND circuit 64 is established, and the third solenoid valve 24 is driven.
This causes the atmosphere to become tertiary, as shown in Figure 2.
The power piston 12 is pushed to the left by the pressure difference between the B chamber and the A chamber, and the push rod 15 is
As a result, force acts on the master cylinder 32 and the brake starts to apply. Atmospheric air is sucked into chamber B through the third solenoid valve 24 until no force is applied to the accelerator pedal 35, that is, the stroke S is 0.
This can be continued until .

On the other hand, when the stroke S is 0, that is, no force is applied to the accelerator pedal 35, and the accelerator pedal 35 is gradually depressed within the brake region (that is, the stroke S increases), the voltage V output from the level conversion circuit 54 ₁ gradually decreases. Along with this, the difference between voltage V ₂ and voltage V ₁ gradually increases. In the range of V ₂ <V ₁ +V ₅ , the signals V ₃ and V ₄ output from the window comparator 69 are at high level, as shown in FIG. 6, so the AND circuits 63 and 64 are Closed. Therefore, the second solenoid valve 23, the third
Both solenoid valves 24 remain closed, and the brake remains applied. Then, when the accelerator pedal 35 is continuously depressed, the voltage V ₂
The difference between V ₁ and V 1 increases, and when V ₂ >V ₁ +V ₅ , the output signal V ₃ of the window comparator 69 becomes low level and the output signal V ₄ becomes high level, as shown in FIG. Therefore, the logic of the AND circuit 63 is established, the second electromagnetic valve 23 is driven, and negative pressure is sent to the B chamber in the master cylinder 31. As a result, the pressure difference between chambers B and A gradually decreases, and the braking force becomes weaker. Therefore, as the accelerator pedal 35 is depressed, the differential pressure voltage increases.
Since V ₂ becomes smaller, the voltage V ₂ approaches V ₁ . Then, when V ₂ <V ₁ +V ₅ , both the output signals V ₃ and V ₄ of the window comparator 69 become high level again as shown in FIG. As a result, the AND circuits 63 and 64 are closed, and both the second solenoid valve 23 and the third solenoid valve 24 are not driven.

Thereafter, by depressing the accelerator pedal 35, the vehicle moves to the neutral region and then to the accelerator region, but the operation in these regions is exactly the same as described above.

In addition, in the above embodiment, when the vehicle speed is low such as 12 km/h or less, the above-mentioned level conversion circuit 54
is switched to a low-speed level conversion circuit 66 to change the degree of brake application. This means that the vehicle speed
This is because when the speed becomes 12 km/h or less, the output of the third comparator 68 becomes low level and the excitation of the relay coil 65c is cut off.

Further, in the embodiment, signals from the steering switch 46 and the constant speed running switch 47 are inputted to an AND circuit 57 via an inverter 50. As a result, the steering switch 46
Alternatively, when the constant speed travel switch 47 is operated, the autobrake operation as described above is disabled. Furthermore, even when an autobrake operation is being performed, when the brake pedal 33 is depressed, the output of the NAND circuit 59 becomes high level.
Flip-flop 61 is reset. As a result, the first solenoid valve 21 and the second solenoid valve 2
3. The third solenoid valve 24 is not driven. 1st above
Since the solenoid valve 21 is normally open, chambers B and A in the master bag 31 are connected and maintained at negative pressure. As a result, the braking operation is performed only by the brake pedal 33.

As detailed above, according to the present invention, the braking force of the vehicle is electrically generated from a signal linked to the accelerator pedal, so the braking force control for the vehicle can simplify the driving operation of the vehicle. system can be provided.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional master bag, Fig. 2 is a cross-sectional view of a master bag used in an embodiment of the present invention, and Fig. 3 is a system configuration of a vehicle brake force control system showing an embodiment of the present invention. figure,
Figure 4 is a diagram showing the state of the accelerator pedal, Figure 5 is a diagram showing the detailed configuration of the control circuit in Figure 3, and Figure 6 is a diagram showing the detailed configuration of the control circuit in Figure 3.
The figure is a characteristic diagram of a window comparator. 21...first solenoid valve, 23...second solenoid valve, 2
4...Third electromagnetic valve, 25...Differential pressure sensor, 31...Master back, 34...Control circuit.

Claims (1)

[Scope of Claims] 1. Two chambers partitioned by a power piston, the air is introduced into one chamber when the brake pedal is operated, and negative pressure is constantly introduced into the other chamber. A master bag in which the power piston moves forward due to a pressure difference between the two chambers to generate braking force for the vehicle, a first control valve provided in the middle of a pipe connecting the two chambers in the master bag, and the master bag. a second chamber provided to control communication between the one chamber in the chamber and the negative pressure source;
a third control valve provided to control communication between the one chamber of the master bag and the atmosphere, a pedal position sensor for detecting the stroke of an accelerator pedal, and detection of the pedal position sensor. and a control circuit that controls the operation of the first to third control valves based on the value, and when the control circuit detects that the amount of depression of the accelerator pedal is equal to or greater than a predetermined value, the control circuit controls the operation of the first to third control valves based on the value. The first control valve is opened and the second and third control valves are closed, and when it is detected that the amount of depression of the accelerator pedal is less than a predetermined value, the first control valve is closed and the second and third control valves are closed. The control valve is configured to control the ratio of atmospheric air and negative pressure introduced into the one chamber by adjusting the opening degree of the control valve, and to increase the ratio of atmospheric air as the amount of depression of the accelerator pedal decreases. Features: Brake force control system for vehicles. 2. A brake switch that detects the depression operation of the brake pedal, and when the control circuit detects that the brake switch is in the operating state, it detects that the amount of depression of the accelerator pedal is less than a predetermined value. 2. The vehicle brake force control system according to claim 1, wherein the vehicle brake force control system is configured to prohibit the control operation of the brake force control system. 3. A constant speed travel switch is provided to operate the constant speed travel device into an operating state, and when the control circuit detects that the constant speed travel switch is in the operating state,
2. The vehicle brake force control system according to claim 1, wherein the brake force control system for a vehicle is configured to prohibit a control operation when it is detected that the amount of depression of the accelerator pedal is less than a predetermined value. 4. It has a vehicle speed sensor that detects vehicle speed, and when the control circuit detects that the vehicle speed is below a predetermined value, it changes the ratio of atmospheric air and negative pressure introduced into the one chamber with respect to the amount of depression of the accelerator pedal. The vehicle brake force control system according to claim 1, characterized in that it is configured as follows.