JPH09272425A - Vehicle deceleration addition device - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: Even if a malfunction or failure occurs in a negative pressure switching valve, an atmospheric pressure switching valve, a control operation system of these, a braking device such as a booster, etc., a pressure in a control room of the booster. The present invention provides a deceleration adding device for a vehicle, in which smooth deceleration is maintained without excessive increase, and brake control and operation system failure are prevented from occurring. SOLUTION: The first and second pressure chambers 12 and 1 are in a non-operating state.
A first control valve 15 for supplying a first pressure to the first pressure control valve 15 and a booster 100 for supplying a second pressure to the second pressure chamber during operation.
In the vehicle deceleration adding device having the second control valve 16 for moving the booster piston 14 in the vehicle braking direction, the accelerator pedal 9 is operated based on the output from the accelerator pedal operating state detecting means for detecting the operating state of the accelerator pedal. A control device that operates the second control valve 16 to add deceleration to the vehicle when it is determined to be in the return state, and when the pressure of the second pressure chamber reaches a predetermined set pressure, And a limiter 30 that shuts off the supply of the second pressure to the second pressure chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deceleration adding device for decelerating a vehicle during traveling.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional vehicle braking system for a booster of a braking system. In the figure, 1 is a brake pedal, 2 is a push rod linked to the brake pedal 1, and 100 is a booster.

In the booster 100, the inside of the housing 20 is divided into three chambers, an atmospheric chamber (hereinafter referred to as A chamber) 11, a negative pressure chamber (hereinafter referred to as B chamber) 12, and a control chamber (hereinafter referred to as C chamber) 13. Divided by 19, 23, B room 12 in the center
The negative pressure from the intake pipe of the engine to the
The negative pressure valve 15 and the atmosphere valve 16 which are driven to open and close from the brake pedal 1 via the push rod 2 so as to guide the atmosphere to the chamber 1 and the C chamber 13 are opened and closed by the brake pedal 1 and are attached to the brake pedal 1. The pedaling force is boosted and transmitted from the booster piston 14 to the master cylinder 8.

Reference numeral 4 is a negative pressure switching valve, and 5 is an atmospheric pressure switching valve, which has a function of switching between supply and interruption of negative pressure or atmospheric pressure to the C chamber 13. 21 is the negative pressure inlet of the B chamber 12,
Reference numeral 22 denotes a pressure introducing port of the C chamber 13, engine negative pressure is introduced into the B chamber 12 from the intake pipe of the engine through the negative pressure pipe 6 and the negative pressure introducing port 21, and the C chamber 13 is switched to the negative pressure. The engine negative pressure or the atmospheric pressure is selectively introduced by switching the valve 4 and the atmosphere switching valve 5.

Reference numeral 3 is a return spring for the push rod 2 and the atmospheric valve 16, 17 is a return spring for the negative pressure valve 15, and 18 is a return spring for the booster piston 14.

In the braking device constructed as described above, the negative pressure switching valve 4 is opened and the atmospheric pressure 5 is closed during normal traveling, so that engine negative pressure is introduced into the B chamber 12 and the C chamber 13. To be done.

Further, since the brake pedal 1 is not depressed, the negative pressure valve 15 is opened and the atmospheric valve 16 is opened.
Is closed, and the negative pressure in the B chamber 12 becomes A through the negative pressure valve 15.
It is also introduced into chamber 11. As a result, Room A 11 and Room B 1
2, all of the C chamber 13 become negative pressure, and the booster 100 becomes inoperative.

During normal braking, when the brake pedal 1 is stepped on, the negative pressure valve 15 is closed by being seated on the piston 14 via the push rod 2, and the atmospheric valve 16 is pushed leftward to open. As a result, the B chamber 12 and the A chamber 11 are shut off from each other, and the atmosphere is introduced into the A chamber 11 through the atmospheric valve 16, so that the atmospheric pressure of the A chamber 11 and the B chamber 12 (and the C chamber 13). The booster piston 14 is pushed to the left by the pressure difference from the negative pressure, and the pedaling force applied to the push rod 2 is boosted to boost the master cylinder 8
And the vehicle is braked.

When the braking force is automatically applied when controlling the vehicle distance, the negative pressure switching valve 4 is closed and the atmospheric pressure switching valve 5 is switched to open, the C chamber 13 becomes atmospheric pressure, and the booster piston 14 becomes It moves to the right due to the pressure difference between the C chamber 13 and the B chamber 12 (negative pressure).

By moving the piston 14 to the right, the negative pressure valve 15 is closed and the atmospheric valve 16 is opened.
Atmospheric pressure is introduced into the chamber 11, and the booster piston 14 is pushed leftward by the differential pressure between the A chamber 11 and the B chamber 12 to act on the master cylinder 8, and the vehicle is braked via the master cylinder 8. By opening and closing the negative pressure switching valve 4 and the atmosphere switching valve 5 as described above, the vehicle is braked without depressing the brake pedal 1.

[0011]

The braking system as described above applies a braking force by operating the negative pressure switching valve 4 and the atmospheric pressure switching valve 5, but depending on the operating method of these switching valves, the braking force is generated. The braking force to be applied is also increased.

Further, in the braking device equipped with the brake system as shown in FIG. 3, malfunction of the negative pressure switching valve 4 and the atmospheric pressure switching valve 5 due to sticking or wear of the valve bodies, The pressure in the C chamber 13 may become excessive due to an abnormality in the control system that controls the opening and closing of these valves. Therefore, in the above-mentioned conventional device, smooth pressure reduction may be hindered by such a pressure increase, which may give the driver a feeling of strangeness.

According to the present invention, even if a malfunction or a failure occurs in the negative pressure switching valve, the atmospheric pressure switching valve, the braking system such as the control operation system or the booster, the pressure in the control chamber of the booster is excessive. Smooth deceleration is maintained without
An object of the present invention is to provide a deceleration adding device for a vehicle, in which a brake control and a failure of an operation system are prevented from occurring.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and its characteristic means is a first pressure chamber and a second pressure chamber into which at least a first pressure is introduced. Booster having a second pressure chamber into which the pressure of 1 is introduced, a first control valve that supplies the first pressure to the first and second pressure chambers when not operating, and the second pressure chamber when operating. And a second control valve for supplying the second pressure to the second control valve for moving the booster piston of the booster in the vehicle braking direction, and an accelerator pedal operation for detecting an operation state of an accelerator pedal. A control device that actuates the second control valve to add deceleration to the vehicle when it is determined that the accelerator pedal is in the return state based on the output from the state detection means and the accelerator pedal operation state detection means. And the above When the pressure in the second pressure chamber reaches a predetermined set pressure, in the provision of the limiter to cut off the supply of the second pressure to the second pressure chamber.

More specifically, the control device includes a negative pressure switching valve connected to a negative pressure source of the engine, an atmospheric pressure switching valve connected to the atmosphere, and a control connected to both switching valves. Chamber, an actuating member for actuating the second control valve in response to the pressure in the control chamber, and actuating both switching valves in response to the output of the accelerator pedal operation state detecting means to cause atmospheric pressure in the control chamber. It is also a preferable means of the present invention to have a control means for supplying the above.

More specifically, the limiter includes an inlet port for air from an atmospheric pressure switching valve connected to the atmosphere, a negative pressure switching valve connected to an engine negative pressure source, and the atmospheric pressure valve. A cylinder having a connected air outlet port to the control chamber, and the engine which is reciprocally fitted in the cylinder and which acts on one side of the atmospheric pressure from the atmospheric pressure switching valve and the other side of the engine. It is also a preferable means of the present invention to provide a piston for switching communication / blocking between the inlet port and the outlet port by a pressure difference between the negative pressure and the combined pressure of the spring force.

A negative pressure switching valve 4, an atmospheric pressure switching valve 5, a control chamber 13 connected to both switching valves, an operating member (booster piston) 14, and an output of the accelerator pedal operation state detecting means. A control device is constituted by the control means (controller) 42 that operates both the switching valves to supply the atmospheric pressure to the control chamber. In FIG. 1, the negative pressure switching valve 4
Is closed and the atmospheric pressure switching valve 5 starts to open, the limiter 30
Sends the atmosphere from the atmospheric pressure switching valve 5 to the control chamber 13 of the booster 100, and the booster piston 14 of the booster 100 closes the negative pressure valve 15 due to the pressure increase in the control chamber 13.
The atmosphere valve 16 is opened. As a result, the atmosphere is introduced into the atmosphere chamber 11, and the booster piston 14 moves in the braking direction due to the pressure difference between the atmosphere chamber 11 and the negative pressure chamber 12.

At this time, when the air pressure to the limiter 30 reaches a predetermined set pressure, the operation of the piston of the limiter 30 shuts off the air flow to the control chamber 13,
The pressure in the control chamber is maintained below the set pressure. As a result, an excessive increase in pressure in the control chamber is avoided, and the negative pressure valve 15 and the atmospheric valve 16 are gently closed or opened by the movement of the booster piston 14, and the subsequent braking of the booster piston 14 as described above. The vehicle is also decelerated by moving in the direction at an appropriate speed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. Not just.

FIG. 1 is a block diagram of a vehicle deceleration adding apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a brake pedal, 2 is a push rod linked to the brake pedal 1, and 100 is a booster. Reference numeral 20 denotes a housing of the booster 100. Inside the housing 20, there are three atmosphere chambers (hereinafter referred to as A chamber) 11, negative pressure chambers (hereinafter referred to as B chamber) 12, and control chambers (hereinafter referred to as C chamber) 13. The chamber is partitioned by diaphragms 19 and 20.

Then, the atmospheric pressure is introduced into the A chamber 11 through the atmospheric valve 16, the engine negative pressure is introduced into the B chamber 12 through the negative pressure pipe 6 and the negative pressure inlet 21, and the C chamber 13 is further introduced. As described later, the engine negative pressure or the atmospheric pressure is selectively introduced from the negative pressure switching valve 4 or the atmospheric pressure switching valve 5 via the limiter 30.

Reference numeral 14 is a booster piston for transmitting a braking force to the master cylinder 8 for braking, 15 is a negative pressure valve provided between the rear end of the booster piston 14 and the push rod 2, and 3 is the pusher. A return spring for the rod 2 and the atmosphere valve 16, a return spring 17 for the negative pressure valve 15, and a return spring 18 for the booster piston 14. Reference numeral 22 is a control pressure inlet of the C chamber 13.

Reference numeral 30 is a limiter, 4 is a negative pressure switching valve connected to the intake pipe of the engine, and 5 is an atmospheric pressure switching valve into which atmospheric pressure is introduced. The limiter 30 has three inlet ports and one outlet port, and the first inlet port 37
Is connected to the outlet negative pressure pipe 43 from the negative pressure switching valve 4 outlet and the atmospheric pipe 44 from the atmospheric pressure switching valve 5, and the negative pressure pipe 6 from the engine intake pipe is connected to the second inlet port 38a. The atmosphere pipe 44 from the atmospheric pressure switching valve 5 is connected to the third inlet port 38b. The outlet port 39 is connected to the atmospheric pressure inlet 22 of the chamber C.

Reference numeral 42 is a controller for transmitting an opening / closing control signal to the negative pressure switching valve 4 and the atmospheric pressure switching valve 5, and the controller 42 is a solenoid of each of the switching valves 4 and 5 via control lines 47 and 48. It is connected to 4a and 5a. An accelerator return switch 10 is connected to the controller 42 by a wiring 50. The switch 10 closes when the accelerator pedal 9 is released from being depressed and returns to the initial position, and transmits an output signal to the controller 42. The controller 42 is provided with a judging means for judging that the accelerator pedal has returned to the initial position when receiving the signal, and the judging means and the switch 10 constitute an accelerator pedal operating state detecting means.

FIG. 2 shows the details of the limiter 30.
FIG. 2A shows the limiter not operating, and FIG. 2B shows the operating state. In the figure, 31 is a cylinder of the limiter 30 and 32 is a reciprocally slidable fit in the cylinder 31. A piston, 33 is a spring for returning the piston 32, 34 is a first fluid chamber, 35 is a second fluid chamber, and 36 is a switching groove formed in the piston 32.

The limiter 30 has the following settings. That is, the pressure in the second fluid chamber 35 is set to P
1, the engine negative pressure is P0, the area of the piston 32 is S, the spring constant of the spring 33 is K, and the displacement of the spring 33 (deflection after mounting) is X, the piston 32 satisfies the following equation (1). Settle in position. P1 ・ S = P0 ・ S + K ・ X (1)

In the spring 33, when the pressure in the second fluid chamber 35 is equal to the engine negative pressure P0, the piston 32 is urged to the left by the elastic force of the spring 33, and in the second fluid chamber 35. When the pressure rises up to a constant pressure set in the controller 42, the left side of the equation (1)> the right side, the spring 33 bends, and the spring constant is adjusted so that the piston 32 can be moved to the right as the pressure rises. K and mounting load are set.

The negative pressure switching valve 4 and the atmospheric pressure switching valve 5 described above.
The control chamber 13 connected to the switching valves, the operating member (booster piston) 14, and the switching valves are operated according to the output of the accelerator pedal operation state detecting means to bring atmospheric pressure into the control chamber. A control device is configured with the control means (controller) 42 to be supplied, and deceleration is added by the control device. During normal driving, the controller 42
The negative pressure switching valve 4 is switched to open and the atmospheric pressure switching valve 5 is switched to closed by the control signal from. On the other hand, in the booster 100, since the brake pedal 1 is not depressed,
The negative pressure valve 15 is opened, and the atmospheric valve 16 is seated on the negative pressure valve 15 and closed by the elastic force of the return spring 3 and the return spring 17 of the negative pressure valve. Therefore, room B 12
The engine negative pressure is always introduced to the A through the negative pressure pipe 6, and this negative pressure enters the A chamber 11 through the negative pressure valve 15, and the A chamber 11 is also a negative pressure.

In the limiter 30, the engine negative pressure passing through the negative pressure switching valve 4 is transferred from the first inlet port 37 and the third inlet port 38b to the switching groove 36 and the second fluid chamber 35.
And the engine negative pressure from the negative pressure pipe 6 is led to the first fluid chamber 34 from the second inlet port 38a.
All rooms are under negative pressure.

Therefore, when the left side of the equation (1) <the right side, the piston 32 is pressed leftward by the elastic force of the spring 33 as shown in FIG. 2 (A), and the switching groove 36 becomes the first inlet port 37. In communication with the outlet port 39, the negative pressure of the first inlet port 37 is guided from the outlet port 39 to the C chamber 13 of the booster 100 via the control pipe 41 and the inlet 22. As a result, the A chamber 11, the B chamber 12, and the C chamber 13 all become negative pressure, and the booster 100 becomes inoperative.

During normal braking, the negative pressure switching valve 4 is opened, the atmospheric pressure switching valve 5 is closed, and the brake pedal 1 is stepped on via the push rod 2 when the B chamber 12 and the C chamber 13 are both under negative pressure. Negative pressure valve 15 is booster piston 14
It is closed by being seated on the air valve 1 and is further moved to the left by the push rod 2 to move the atmospheric valve 1
6 is pushed to the left, separated from the negative pressure valve 15 and opened.

As a result, the B chamber 12 and the A chamber 11 are cut off from each other, and the atmosphere is introduced into the A chamber 11 through the atmosphere valve 16, whereby the atmospheric pressure of the A chamber 11 and the B chamber 12 (and the C chamber). The booster piston 14 is pushed to the left by the pressure difference from the negative pressure of 13), the pedaling force applied to the push rod 2 is boosted and transmitted to the master cylinder 8, and the vehicle is braked.

When it is detected by the accelerator return switch 10 that the driver has released the accelerator pedal 9,
By the control signal from the controller 42, the negative pressure switching valve 4
Is closed and the atmospheric pressure switching valve 5 is switched to open. The atmospheric pressure passing through the atmospheric pressure switching valve 5 is guided to both the first inlet port 37 and the second inlet port 38b of the limiter 30 via the atmospheric pipe 44.

At this time, the controller 42 controls the closing speed of the negative pressure switching valve 4 and the opening speed of the atmospheric pressure switching valve 5 to operate the limiter 30 according to the kinetic formula (1), and the C chamber 13 The internal pressure and its rising speed are controlled based on a control map in which the relationship between the control time (opening / closing time of the atmospheric pressure switching valve and the negative pressure switching valve) and the braking deceleration is set.

From the beginning of the opening of the atmospheric pressure switching valve 5 and the closing of the negative pressure switching valve 4, as long as the pressure of the air (atmosphere) guided to the limiter 30 does not reach the constant set pressure PS, the formula (1) is used. The first inlet port 37 and the outlet port 39 of the limiter 30 are in communication with each other such that the left side is smaller than the right side, and the air from the atmospheric pressure switching valve 5 is guided from the limiter 30 to the C chamber 13 via the atmosphere pipe 41.

Here, the negative pressure valve 15 of the booster 100 is opened,
Since the atmospheric valve 16 is closed, the negative pressure in the B chamber 12 is guided to the A chamber 11 via the negative pressure valve 15, and the B chamber 12, the A chamber 1
Both are negative pressure. Therefore, the booster piston 14 moves to the right in FIG. 1 due to the pressure increase in the C chamber 13.

When the negative pressure valve 15 is closed by moving the booster piston 14 to the right, application of negative pressure to the chamber A 11 is cut off, and when the atmospheric valve 16 is opened, the atmospheric valve 16 is opened. Atmosphere is introduced into the A chamber 11 through.

As a result, the pressure in the chamber A becomes atmospheric pressure, and A
Booster piston 1 due to the pressure difference between chamber 11 and chamber B 12
4 is moved to the left in FIG. 1, and the displacement of the booster piston 14 to the left is transmitted to the master cylinder 8. At this time, by the operation of the limiter 30, the following smooth slow deceleration operation is performed.

When the opening degree of the atmospheric pressure switching valve 5 increases and the air pressure to the limiter 30 rises to the set pressure PS so that the left side of the equation (1)> the right side, the piston 32 of the limiter 30 moves to the position shown in FIG. 2) is displaced to the right, and the first inlet port 37 and the outlet port 39 are disconnected from each other.
The state shown in FIG. As a result, the supply of air to the C chamber 13 is shut off.

Therefore, as shown in FIG. 2 (B), the pressure in the C chamber 13 does not rise above the set pressure PS when the limiter 30 is fully closed, and when the atmospheric pressure switching valve 5 is opened. C
The pressure in the chamber 13 is maintained below the set pressure PS set in the limiter 30, the booster piston 14 is smoothly operated in the deceleration direction (left in FIG. 1), and 0.2 G
Slow deceleration is performed to some extent.

Although the negative pressure type booster is used in this embodiment, the present invention is not limited to this, and the present invention can be applied to other braking boosters such as a hydraulic booster.

[0042]

According to the present invention, when the air pressure supplied from the atmospheric pressure switching valve through the limiter to the control chamber of the booster reaches the set pressure set in the limiter, the limiter causes air to reach the control chamber. Is cut off, the pressure in the control chamber is maintained below the set pressure, and an excessive increase in pressure is avoided.

Thus, the closing / opening operation of the negative pressure valve and the atmospheric valve of the booster piston of the booster and the subsequent deceleration operation by the movement in the braking direction are smoothly performed at an appropriate speed. Therefore, the operation of the limiter prevents the pressure in the control chamber from becoming excessively high due to a failure of the atmospheric pressure switching valve in an open state, an abnormality in the control signal due to a malfunction of the booster, or the like. , It is possible to prevent the addition of excessive deceleration.

Further, in the vehicle deceleration adding device for assisting the engine braking and reducing the braking operation frequency to facilitate the driving operation, it is possible to prevent the deceleration more than necessary due to the malfunction of the system, and It is possible to drive for a short time and realize stable driving.

Further, since the pressure characteristic of the control chamber of the booster can be set by the spring characteristic of the limiter, smooth operation control becomes possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a vehicle deceleration adding device according to an embodiment of the present invention.

FIG. 2 is a structural diagram of a limiter in the embodiment.

FIG. 3 is a diagram illustrating a conventional example of a vehicle braking device according to a booster of a braking device.

[Explanation of symbols]

 1 Brake Pedal 4 Negative Pressure Changeover Valve 5 Atmospheric Pressure Changeover Valve 8 Master Cylinder 11 Atmosphere Room (A Room) 12 Negative Pressure Room (B Room) 13 Control Room (C Room) 14 Booster Piston (Operating Member) 15 Negative Pressure Valve 16 Atmosphere Valve 30 Limiter 31 Cylinder 32 Piston 33 Spring 34 First fluid chamber 35 Second fluid chamber 36 Switching groove 37, 38a, 38b First, second and third inlet port 39 Outlet port 42 Controller (control means) 100 Booster

Claims (3)

[Claims] 1. A first to which at least a first pressure is introduced
A booster having a pressure chamber and a second pressure chamber into which a second pressure is introduced; a first control valve that supplies the first pressure to the first and second pressure chambers when not in operation; A deceleration adding apparatus for a vehicle, comprising: a second control valve that supplies the second pressure to the second pressure chamber to move a booster piston of the booster in a vehicle braking direction. When it is determined that the accelerator pedal is in the returning state based on the output from the accelerator pedal operating state detecting means for detecting and the accelerator pedal operating state detecting means,
A control device that operates the second control valve to apply deceleration to the vehicle; and when the pressure in the second pressure chamber reaches a predetermined set pressure,
A deceleration adding device for a vehicle, comprising a limiter for cutting off the supply of the second pressure to the second pressure chamber. 2. The control device includes a negative pressure switching valve connected to a negative pressure source of an engine, an atmospheric pressure switching valve connected to the atmosphere, a control chamber connected to both switching valves, and the control chamber. An actuating member for actuating the second control valve in response to the pressure of the control valve, and a control means for actuating the two switching valves in response to the output of the accelerator pedal operation state detecting means to supply atmospheric pressure to the control chamber. The deceleration adding device for a vehicle according to claim 1, characterized in that it has. 3. The limiter is connected to an air inlet port from an atmospheric pressure switching valve connected to the atmosphere, a negative pressure switching valve connected to a negative pressure source of the engine, and a control chamber connected to the atmospheric pressure valve. A cylinder having an air outlet port, and the atmospheric pressure from the atmospheric pressure switching valve acting on one side and the engine negative pressure and the spring force acting on the other side 2. The deceleration adding device for a vehicle according to claim 1, further comprising: a piston that switches between communication and interruption of the inlet port and the outlet port according to a pressure difference between the combined pressure and the combined pressure.