FR2465623A1 - Motor vehicle remote controlled hydraulic braking system - uses ratio control to regulate vacuum operated auxiliary hydraulic master cylinder from outside vehicle - Google Patents

Abstract

The braking system is intended for installation in vehicles used for solo driving tuition with the instructor in a following vehicle. An auxiliary master cylinder (13) is operated by engine vacuum connected through pipes (22), a vacuum reservoir (23), and a non-return valve (24). When a signal is sent from the controlling vehicle a receiver (19) on the controlled vehicle detects the signal and the detector operates a contact (20) to activate a solenoid (S) which operates a valve (14). This allows atmospheric pressure to drive a piston (10) which drives the piston of the auxiliary master cylinder, delivering hydraulic pressure, via a conduit (6), to the main master cylinder (1) and thus operating the vehicle brakes. By variation of the dimensions of the atmosphere inlet (15) and the vacuum lines (17) the sharpness of brake application and release is adjustable, and by pulsed control signals the average braking effort may be varied.

Description

COX BE HYDRAULIC DEVICE REMOTE FROM VEHICLE BRAKES
AUTOMOBILES.

The invention due to the collaboration of Jean-Pierre SERPETTE relates to a hydraulic remote control device for motor vehicle brakes.

The invention relates more particularly to a device for controlling the brakes of a motor vehicle intended for driving schools in which the student driver takes place while the instructor is on board a follower vehicle, the so-called student and instructor communicating enter them by means of a radio link.

Such a mode of driving instruction must allow the instructor to initiate emergency braking regardless of the student's will.

Patent 2,260,479 discloses a hydraulic brake control device which has a first master cylinder whose piston is controlled by pressing the driver's foot on the brake pedal, an auxiliary master cylinder whose piston is controlled by release it from the accelerator pedal by means of a rod coupled to the movable partition of a box with two compartments respectively connected to the engine vacuum and to the atmosphere, means for maintaining the pressures in the two compartments equal , as long as the release of the accelerator pedal is not implemented and to move the movable partition in the direction of control of the second master cylinder as a result of the release of said pedal.

The invention aims to apply the aforementioned device with a view to enabling it to trigger braking of the training vehicle from a follower vehicle.

The application is first made possible by sizing the master cylinder and the movable partition of the box to obtain an energetic deceleration (for example 6m / s2).

The application is also made possible as a result of the use of an electro-pneumatic control actuated by the instructor of the following vehicle, the implementation of which makes it possible to actuate the movable partition of a box with two compartments respectively connected to the engine intake manifold and to the atmosphere.

In accordance with the invention, means for equalizing the pressures in the compartments of the case and for creating a differential pressure force for actuating the control rod of a pressure generator (such as an auxiliary master cylinder). consist of an electrovalve controlled by a control device carried by a follower vehicle.

In what follows, two embodiments of the invention will be described with reference to the accompanying drawing in a nonlimiting manner.

Figure 1 of the drawing schematically shows the control device according to the invention.

Figure 2 shows the characteristic deceleration curve of the vehicle.

Figure 3 shows a variant of the device.

In the illustrated embodiments, the installation comprises a master cylinder 1, the piston of which is connected by a push rod 2 and possibly by an assistance mechanism 3 to a braking pedal 4.

The supply port 5 of the vehicle brakes is connected to the outlet of the malter-cylinder.

The device further comprises an auxiliary command triggered remotely from a follower vehicle. This command is constituted by a box 7 separated into two compartments 8, 9 by a mobile or deformable watertight partition 10 connected to a rod 11 which slides in an annexed hydraulic pressure generator 13 such as an auxiliary master cylinder, the opening of which output is connected to the main master cylinder 1 by a channel 6.

The supply line 5 is connected to the brakes and simultaneously receives the control pressure generated by the pistons of the master cylinders 1, 13, that is to say by the control of the brake pedal and by the control triggered at distance from the following vehicle.

The means necessary for controlling the generator 13 are constituted by a 3-way solenoid valve 14 respectively connected to the open air and to the compartments 8, 9 by means of pipes 15, 16, 17.

The solenoid valve 14 is controlled remotely from the follower vehicle by means of a remote control 18 which actuates a relay 19, the closing contact 20 of which energizes the solenoid valve 14.

The remote control 18 which is not part of the invention comprises for example a signal generator mounted on the following vehicle which is controlled by the instructor, a receiver and a remote control signal transmitter mounted on the following vehicle; a receiver and a transmitter of signals on the school vehicle, the latter actuating the relay 19.

The compartment 9 of the housing 7 is permanently connected to the suction pipe of the motor 21 by a line 22 through a reservoir 23 and a non-return valve 24.

The compartment 8 of the housing 7 is connected by the pipe 16 to the 3-way solenoid valve 14, the other two tracks 17, 15 of which are connected respectively to the compartment 9 and to the atmosphere.

The solenoid valve 14 can occupy two positions.

The so-called rest position I corresponds to the de-energized state of the empty soles "S" of the valve 14.

The active position Il1 corresponds to the excited state of the solenoid "S" via the contact; 20. The eontact 20 also enables the braking signal lights 28 to be energized.

The operation of the device is as follows.

In the rest position, the channel 15 for setting the atmosphere is isolated and the channels materialized by the conduits 16, 17 are in communication. The engine pressure is established in the reservoir 23 and in the chambers 8, 9 at its maximum value thanks to the presence of the non-return valve 24. The atmospheric pressure is established in the chamber 8 while the engine vacuum prevails in the room 9.

The partition 10 is therefore pushed to the right of FIG. 1 and displaces the rod 11 and the piston of the master cylinder 13.

If care is taken to reduce the venting line by throttling 15, the venting of the chamber 8 can be delayed. This device makes it possible to obtain more progressive braking, as shown by the portion with characteristic OA (fig. 2). On the other hand, taking care to dimension the pipes 16, 17 more broadly, it is possible to obtain a rapid elimination of the brake effect after return of the electrovalve to the rest position as shown by the portion of characteristic AB. The aforementioned timing allows the instructor in the following vehicle to measure the braking of the training vehicle by successive pulses on the remote control.

FIG. 3 represents an alternative embodiment of the invention in which the movable partition housing acts directly on the main master cylinder 1. In the drawing, a device associated with a brake booster is shown which has two bodies 40, 41. The "downstream" body 40 fulfills the function of the housing 7 and has two compartments 48, 49 connected in the manner of the compartments 8, 9 of the device illustrated in FIG. 1. The "upstream" body 41 is controlled by the brake pedal and keeps the set of conventional servo valves 42.

Claims (2)

- CLAIMS 1 ") Hydraulic remote control device for motor vehicle brakes which has in particular a main master cylinder whose piston is controlled by pressing the driver's foot on the brake pedal, a controlled pressure generator remotely from a follower vehicle by means of a rod coupled to the movable partition of a box with two compartments respectively connected to the suction pipe of the engine and to the atmosphere, means for keeping the pressures in the compartments as long as the remote control is not triggered and to move the partition in the generator control direction1 by triggering the remote control, the generator outlet duct being connected to the master cylinder main, the outlet of which is connected to the brake lines, characterized in that the means for equalizing the pressures in the compartments (8, 9) of the housing (7) and of creating tion of a differential pressure force of the pressure generator are constituted by an electrovalve (14) slaved to the control device carried by the following vehicle1 in order to generate an energetic emergency braking independently of the action of the foot of the driver of the vehicle, by placing one of the compartments of the box in communication with the suction pipe and the other compartment with 20) control device according to claim 1, characterized in that the venting of the solenoid valve, has a throttle in order to delay the setting in the atmosphere of the corresponding compartment of the case, and ensure progressive braking. 30) Control device according to claim 1 or 2, character  laughed at by the fact that the compartment (9.49) of the case (7.40)  is connected to the suction pipe of the motor by means of  diary of a tank (23) and a non-return valve (24). 40) control device according to claim 1 or 2 charac-  se by the fact that the box (40) is attached to another box tier which is constituted by a servo brake with servo valves  semi known per se.