JPS6277275A - Servo assisted brake - Google Patents

Abstract

PURPOSE:To avoid shock at actuation or releasing of a brake by, when opening at least one of supply and exhaust opening and closing valves, continuing the opening condition of the opening and closing cycle thereof. CONSTITUTION:A fluid passage switching mechanism 44 has on one side a supply opening and closing valve 50 communicating to the atmosphere and on the other side an exhaust opening and closing valve 51 communicating to a negative pressure source through a conduit 52. The pair of opening and closing valves 50 and 51 are opened and closed under control of a control unit 53. The control unit 53 receives a manipulated variable of a hand brake operating member 55, such as a signal from a manipulated variable detector 56 or a signal from a stopping brake device 57 so as to switch fluid passages of the fluid passage switching mechanism 44 according to the signal and thereby to allow the atmospheric pressure to be introduced into a pressure chamber located backside.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a play+ device, and more particularly to a brake device with a player booster.

``Traditional tricks'' ・Is the brake booster usually IP inside the shell? A freely movable power piston and this power screw!・The valve mechanism is housed in the valve body of the shaft.

! , a constant j formed on the front side of the power piston in the operating direction
I: Operate the chamber and the variable pressure chamber formed on the rear side, and the valve plunger constituting the 1-JR mechanism to switch the flow path,
Supply pressure fluid to the temperature and pressure chamber to move the power piston to +W
It is equipped with an input shaft that advances i.

In this type of conventional brake booster, the l-manpower axis]! 1! Braking is performed by depressing the blocked brake pedal with the foot, and the brake booster is used as a stop brake device that allows braking to be performed even when the brake pedal is not depressed. When used, normally, seven actuators are connected to the 1-input input shaft to move the human-powered shaft forward.

In addition, when the above-mentioned brake booster is used as a manual brake device that can perform braking action by toe motion, the above-mentioned human power axis can be used instead of the brake pedal.
The operating members were connected to each other.

However, when connecting the 7 actuator to the input shaft, the actuator is added to the outside of the brake booster, which has the disadvantage of increasing the size of the entire device. - When the dynamic brake operating member was connected, the brake could not be operated with the foot.

As a brake booster that solves such problems,
The applicant of this application has already attached an auxiliary piston to the I-valve plunger in Tokusho [No. 1O-24607, etc.], divides and forms a pressure chamber in the valve body with this auxiliary piston, and furthermore, A brake booster is proposed that is provided with a supply-side opening/closing valve Jt for supplying pressure fluid and a discharge-side opening/closing valve for discharging pressure fluid from a pressure chamber.

According to the brake booster having such a configuration, the supply side on-off valve is opened with the discharge side on-off valve shut off to supply pressurized fluid to the pressure chamber, and the auxiliary piston and valve plunger are moved forward using the pressure. By switching the flow path of the valve mechanism, it is possible to perform the braking action without moving the human power shaft forward.Therefore, the 7 actuator can be installed outside the brake booster and used as a stop brake device without sinking. Alternatively, it can be used as a static braking device that ensures execution of the braking action by depressing the brake pedal.

"The invention aims to solve one problem in t." However,
”Using an on-off valve to control the supply and discharge of pressure fluid to and from the two-leg pressure chamber has the advantage of improving responsiveness, but since the opening operation is instantaneous, There is a disadvantage that the pressure suddenly increases or decreases, causing shock. In order to reduce this, if the flow path area of the f two-leg open/close valve is made smaller, even if the shock can be prevented from occurring, there will be a delay in operation, making it difficult to obtain a quick braking action while preventing the shock from occurring. Met.

[Means for Solving the Problems] In view of such iG circumstances, the present invention provides the above-mentioned brake booster with an auxiliary piston attached to the valve plunger, and a section formed within the bipedal valve body by the auxiliary piston. A pressure chamber that is formed and introduced by a Zlil pressure body) that causes the foot pressure auxiliary piston and the valve plunger to switch the flow path of the valve mechanism to operate the brake, and this pressure chamber and the supply of pressure fluid. a supply-side on-off valve that is provided in a communication path that communicates with the source and opens and closes the communication path;
1- A discharge-side on-off valve that is provided in a communication path that communicates the pressure chamber and a discharge source that discharges the pressure introduced into the pressure chamber and opens and closes the same; I- A supply-side on-off valve and a discharge-side on-off valve and a control device for controlling the supply and discharge of pressure fluid to the pressure chamber by controlling opening and closing, and the control device in parentheses opens at least one of the supply side on-off valve and the discharge side on-off valve, Open and close the on-off valve the required number of times and then return it to the open state.
It is designed to be continuous.

"Function" According to such a configuration, by opening and closing the on-off valve the required number of times, it is possible to reduce the pressure at the time before the brake operation was started, and by continuing to open the valve thereafter, it is possible to increase the pressure increase. , it is possible to obtain a quick braking action while preventing shoving.

"Example" The invention will now be described with reference to illustrative embodiments.

In FIG. 1, a power piston 2 is slidably inserted into a shell l of a brake booster, and a diaphragm 3 is stretched and sunk into the back of the power piston 2, and the power piston 2 and diaphragm 3 1- The interior of the shell 1 is divided into a constant pressure chamber 4 at the front and a variable pressure chamber 5 at the rear. A valve body 6 is integrally provided on the shaft portion of the power piston 2, and a valve mechanism 7 for switching the flow path is housed within the valve body 6.

The valve mechanism 7 is a first valve seat 1 formed on the help body 6.
A valve body 14 is provided on the second valve seat 12 formed on the valve plunger 11 and on both valve seats 1O112 from the rear side of the power piston 2, that is, from the right side in FIG. 1, by the elastic force of a spring 13. Then, the outside of the seat part between the seat lO and the valve body 14 is made to pass through the J-distribution pressure chamber 4 through the passage 15, and the constant pressure chamber 4 is further provided in the shell l. It communicates with a negative pressure source such as an engine intake manifold (not shown) through a negative pressure introduction pipe 16.

On the other hand, the intermediate portions of the seals between the l foot 15r seat IO and the valve body 14, and the second valve seat 12 and the valve body 14 are connected to the variable pressure chamber 5 through the passage 17Q formed in the valve body 6. Furthermore, the inner side of the note portion between the valve seat 12 and the valve body 14 is communicated via a filter 18.

The food distribution pressure chamber 5 is kept airtight from the outside by a sealing member 19 that slidably passes through the I-valve body 6.

! - The valve plunger 11 constituting the valve recording mechanism 7 is connected to a human power shaft 25 that is linked to a brake pedal (not shown).
Further, the tip surface of the valve plunger 11 is connected to a reaction disk 2 housed in a recess formed in the deaf part of the output shaft 2B.
It is facing 7. The output sleeve 26 passes through the seal member 28 and projects to the outside of the shell 1, and is linked to a piston of a master cylinder (not shown).

Normally, the power piston 2, valve body 6, etc. shown in l- are held in the non-operating position shown in the figure by a return spring 29, and in this non-operating state, l+t+2
5. The key member 30 that prevents the plunger 11 from being pulled out of the valve body 6 comes into contact with the inner surface of the shell l and restricts the free movement of the valve plunger 11 to the right with respect to the valve body 6. When the shaft 25 and the valve plunger 11 are actuated, the fluid circuit can be switched immediately by the valve distributor 4I!7.

The structure and operation described above are basically the same as those of conventionally known negative pressure type brake boosters, so a description of the operation will be omitted.

However, in this embodiment, the valve body 6 is composed of a stepped cylindrical body 6d and a fixed plate 8b attached to the left end surface of the stepped cylindrical body 6d. A disk-shaped auxiliary piston 35 is disposed within a space formed within the large diameter portion of the piston. This auxiliary piston 35 is -
[-Snap ring 3G installed on valve plunger I+
A diaphragm 37 is provided between the 1ν surface of the auxiliary piston 35 and the valve body 6.

The diaphragm 37 divides the space into two pressure chambers 38.
39, and the pressure chamber 38 on the )li side is 1-
The inside of the pressure chamber 4 is always in communication via a passage 40 bored into the fixed plate 6b, and the rear pressure chamber 39
is a passage 4I formed in the valve body 6, arranged spirally in the constant pressure chamber 4, and connected to the help body 6.
, conduit 42. and a channel for supplying pressure fluid to the pressure chamber 39 via a conduit 43 connected to its conduit 42 outside the shell l! , is connected to the IJ exchange mechanism 44.

In the illustrated embodiment, the channel switching mechanism 44 is composed of two magnetic on-off valves 50 connected to each other, and the conduit 43 is connected to two on-off valves 50, 51. In addition, one of the supply side opening/closing valves P50 is connected to the outlet side opening/closing valve Jr51 of the capacity through a conduit 52 to a negative Ir source (not shown). The above pair of opening/closing 1 (
5o and 51 are control devices 5 including microcomputers;
The opening and closing are controlled by 3.
This control device 53 controls the f-1 rib brake operating member 55 (for example, the size of human power and the stroke 5'1).
1゛9 detection operation; , the signal from the S detector 56,
Stop-1 (manually inputs a signal indicating that the brake device 57 is on, switches the flow path of the flow path switching mechanism 44 according to the signal as will be described in detail later, and introduces atmospheric pressure into the pressure chamber 39 on the rear side) is now possible.

The stationary brake device 57 includes a 11-speed sensor 58, a brake ramsuite, 59. accelerator switch 60,
Parking brake switch 61, four-way transfer side door switch 62. and an external brake release switch 63.

In the brake booster having the above configuration, when the manual brake operating member 55 is not operated and the external brake device 57 is not operated, the control device 53 closes the supply side on-off valve 50. , the discharge side on-off valve 51 is open. In this state, negative pressure is introduced into the double-edged pressure chambers 33 before and after the auxiliary piston 35, and no pressure difference occurs between the front and rear of the auxiliary piston 35. By moving the brake booster 25 forward, it is possible to perform the same operation as a conventionally known brake booster without the auxiliary piston 35.

Next, in the running state of both cars in which the key device 57 is not activated and the brake booster is in the non-operating state fm where the brake pedal is not depressed, When the r7 dynamic brake operating member 55 is operated,
Operation I11 detection'r A message corresponding to the operation section from S5B
) is input to the control device 53. Then, the control device 53 calculates the change in manual brake operation per unit time from the input t), and when the change is an increase, that is, when the brake force is strengthened, the discharge side on-off valve 511t is
At the same time, the opening time t of the supply side on-off valve 50 is calculated depending on the magnitude of the change or fake.

If the calculated opening time t is less than the predetermined reference time, the control device 53 simply opens the supply side on-off valve 50 for the opening time t and shuts it off (see Figure 2d). If the opening time t exceeds the predetermined reference time, the supply side on-off valve 50 is instantaneously opened and closed the required number of times, and then the open state is continued, so that the entire opening time becomes the opening time t described in -F. When this happens, the supply side on-off valve 50 is shut off (see Figure 2b).

In addition, the control device 53 continues to calculate a new dynamic brake operation change value, and -■- the release position ffHt.
If it is necessary to immediately open the supply-side on-off valve 5o again after the elapse of , the supply-side on-off valve 5o is not shut off even after the opening time t has elapsed until a new opening time t elapses. The supply side on-off valve 5o is maintained in an open state. In addition, after the opening time of the city has elapsed, the supply side on-off valve 5o is not shut off until the next opening time elapses.
When o is left open, supplement 11 [such as shortening the primary opening time by a small amount of time may be added in consideration of the inertia of the flow of pressure fluid.

When the supply side on-off valve 5o is opened in this way, the auxiliary piston 35 is
Atmospheric air is introduced into the pressure chamber 39 on the rear side of the
Since the pressure introduced into C moves the valve plunger 11 forward via the auxiliary piston 35, the flow path of the two-legged valve mechanism 7 is switched and the f-dynamic braking action is performed. Since the supply side on-off valve 5o is opened for an opening time corresponding to the magnitude of the operation j- of the manual brake operating member 55, the pressure supplied to the pressure chamber 39 is controlled by the brake operating member 5.
The pressure is controlled according to the operation applied in step 5.

In addition, at that time, as described above, if the opening time t of the supply side on-off valve 50 is longer than the reference time, the control device 53
Since the supply-side on-off valve 50 is instantaneously opened and closed a required number of times and then maintained in the open state, the pressure in the pressure chamber 39 can be smoothly and quickly brought to 1-t.

That is, as shown by the symbol a in FIG. 3, the supply side on-off valve 5
If 0 is simply opened, the rise in pressure will be too large, especially at the start of brake operation, causing a shock.

To prevent this (1) and (2), reducing the flow path surface end of the supply side opening/closing valve f5D eliminates the shock, but due to the pressure,
94 becomes small, causing a delay in braking action.

In addition to this, if the supply side on-off valve 50 is instantaneously opened and closed a required number of times and then maintained in the open state, as shown by the reference numeral in FIG. Since νL can be reduced and the subsequent pressure rise can be increased, a rapid braking action can be obtained while preventing a shock at the start of braking action. Note that the symbol C in FIG. 3 indicates the supply side on-off valve 50.
The figure shows the pressure increase when the supply side on-off valve 50 is always opened and closed continuously, and in this case, the same result as when the flow path area of the supply-side on-off valve 50 is made small is obtained.

As described above, when the number of operating parts of the manual brake operating member 55 increases, the control wave 2153 controls the opening time of the supply side on-off valve 50 to introduce fluid into the F pressure chamber 39. Although the pressure is controlled to a pressure that corresponds to the change in dynamic brake operation, even if the operation value of the manual brake operation member 55 decreases, the pressure will be controlled in accordance with the decrease change noise in exactly the same way as described above. By controlling the opening time of the discharge side on-off valve 51, the wave body pressure introduced into the pressure chamber 39 is also controlled to a pressure corresponding to the operation value.

Then, when the operation of the +0 brake operating member 55 is completely released, the control wave F153 is applied to the supply side on-off valve 50.
is closed and the discharge side on-off valve 51 is opened, so the fluid pressure introduced into the pressure chamber 39 is completely discharged and the flow path of the valve mechanism 7 returns to the non-operating state, thereby releasing the brake action. L dynamic brake operation is released.

Next, 1. The control device 53 detects the speed of the small circle by 1 (speed sensor 58), and also detects by the brake lamp switch 6I that the brake pedal is depressed and human power is applied to the human power axis, and the brake pedal is depressed. The city is stopped due to being stepped on, and 1j1) The ridge is stopped +11
When it is detected that the brake pedal has been continuously depressed for a predetermined waiting time after the brake pedal is pressed, the control device 7153
closes the discharge side on-off valve 51 and closes the supply side on-off valve 5.
Open 0.

At this time as well, the control device F 53 instantaneously opens and closes the supply side on-off valve 5° a required number of times and then continues the open state.
It is possible to prevent a shock from occurring when the operation starts. When the supply side on-off valve 50 is opened, atmospheric pressure is introduced into the pressure chamber 38 and the valve plunger 11 is urged forward via the auxiliary piston 35.
Even if the pedaling force applied to the brake pedal is released or the operation of the f-dynamic brake operating member 55 is released, the flow path of the valve mechanism 7 maintains its state, so that the braking action is continued.

According to this, the stop brake system δ57 is
A parking brake switch 61 and a door switch 62 for the driver's seat are provided so that the driver does not leave the driver's seat in that state when the 1i vehicle is stopped, and if the door is opened without pulling the parking brake. control device 5
3, the alarm 64 can be activated.

Further, when the control device 53 detects that the accelerator switch 60 that detects the depression of the accelerator pedal or the stop/brake release switch 63 due to L movement is operated,
The control device 53 closes the supply side on-off valve 5o, and instantaneously opens and closes the discharge side on-off valve 51 a required number of times before opening it, so that the atmospheric pressure introduced into the pressure chamber 39 is discharged and the valve mechanism 7 returns to the inoperative state, thereby releasing the braking action and deactivating the external brake device without causing a shock.

In the above embodiment, it is clear that the normal braking action by the brake pedal and the dynamic braking action by the manual brake operating member 55 can be performed at the same time.Furthermore, in the shoe-wearing embodiment, when the opening/closing valves 50 and 51 are opened, Although each of them performs instantaneous opening/closing operations, it is also possible to perform only one of them depending on the eight ships.Furthermore, in the above embodiment, the human power detector is used as a human power detector to detect that pedal force is applied to the human power shaft 25. Although the brake lamp switch 61 is used, it is not limited to this.
It is also possible to directly detect the pedal force applied to the input shaft 25 by a load sensor, or to detect the brake fluid pressure generated in the master cylinder by the pressure case 7.

"Effects of invention" Since [-, according to the present invention, play +'A 21
The advantage is that the trigger can be activated quickly without causing a shock when activated or released.

[Brief explanation of drawings]

Fig. 1 is a systematic sectional view showing one embodiment of the present invention;
Figure 11 and Figure 2b illustrate the operation when the on-off valve opens.
The IJI diagram and Figure 3 show the three types of opening/closing operations of the on-off valve and the resulting pressure 1. It is a characteristic diagram showing which relationship. ■...Shell 2...Power piston 4
... Constant pressure chamber 5 ... Variable pressure chamber 6 ... Help body 7 ... Valve mechanism 1.1 ... Valve plunger 25 ... Input shaft 35 ... Auxiliary piston
39... Pressure chamber 44... Wave path switching mechanism 50
...Supply side on-off valve 51...Discharge side on-off valve 53
...Control device 55...F-dynamic brake operating member 56...Operation wear detector 57...Stop brake device Fig. 2a Fig. 2b

Claims (1)

[Claims] A power piston slidably disposed within the shell, a valve mechanism housed within the valve body of the power piston shaft, a constant pressure chamber formed on the front side in the operating direction of the power piston, and a variable pressure chamber formed on the rear side. A brake booster comprising: a chamber; and an input shaft that operates a valve plunger constituting the valve mechanism to switch a flow path and supply pressurized fluid to the variable pressure chamber to advance the power piston; an auxiliary piston attached to the auxiliary piston, and a section formed in the valve body by the auxiliary piston, and the introduced fluid pressure advances the auxiliary piston and the valve plunger to switch the flow path of the valve mechanism to perform a braking action. A pressure chamber, a supply-side on-off valve provided in a communication path that communicates the pressure chamber and a pressure fluid supply source to open and close the pressure chamber, and a discharge source that discharges the pressure introduced into the pressure chamber and the pressure fluid supply source. a discharge side on-off valve that is provided in a communication passage that communicates with the above and opens and closes the same, and a control device that controls the opening and closing of the supply side on-off valve and the discharge side on-off valve to control the supply and discharge of pressurized fluid to the pressure chamber. A brake booster characterized in that, when at least one of the supply-side on-off valve and the discharge-side on-off valve is opened, the control device opens and closes the on-off valve a required number of times and then continues the open state. Brake device with.